Neurodegeneration and Vision Loss after Mild Blunt Trauma in the C57Bl/6 and DBA/2J Mouse

PubMed Central

Bricker-Anthony, Courtney; Rex, Tonia S.

2015-01-01

Damage to the eye from blast exposure can occur as a result of the overpressure air-wave (primary injury), flying debris (secondary injury), blunt force trauma (tertiary injury), and/or chemical/thermal burns (quaternary injury). In this study, we investigated damage in the contralateral eye after a blast directed at the ipsilateral eye in the C57Bl/6J and DBA/2J mouse. Assessments of ocular health (gross pathology, electroretinogram recordings, optokinetic tracking, optical coherence tomography and histology) were performed at 3, 7, 14 and 28 days post-trauma. Olfactory epithelium and optic nerves were also examined. Anterior pathologies were more common in the DBA/2J than in the C57Bl/6 and could be prevented with non-medicated viscous eye drops. Visual acuity decreased over time in both strains, but was more rapid and severe in the DBA/2J. Retinal cell death was present in approximately 10% of the retina at 7 and 28 days post-blast in both strains. Approximately 60% of the cell death occurred in photoreceptors. Increased oxidative stress and microglial reactivity was detected in both strains, beginning at 3 days post-injury. However, there was no sign of injury to the olfactory epithelium or optic nerve in either strain. Although our model directs an overpressure air-wave at the left eye in a restrained and otherwise protected mouse, retinal damage was detected in the contralateral eye. The lack of damage to the olfactory epithelium and optic nerve, as well as the different timing of cell death as compared to the blast-exposed eye, suggests that the injuries were due to physical contact between the contralateral eye and the housing chamber of the blast device and not propagation of the blast wave through the head. Thus we describe a model of mild blunt eye trauma. PMID:26148200

Anti-VEGF and its impact on the outer retina: retinal pigment epithelium tear after an injection of aflibercept in contralateral eye.

PubMed

Campos Polo, R; Rubio Sánchez, C

2016-05-01

A 62-year-old woman with a history of bilateral retinal pigment epithelium detachment (PED), secondary of age-related macular degeneration (AMD), who presented with a retinal pigment epithelium (RPE) tear on her left eye after an aflibercept injection in the contralateral eye one month earlier. A RPE tear is the main complication when the anti-VEGF therapy is used for the management of the PED. Furthermore, it should be noted that systemic absorption of the drug can induce an effect on the untreated eye. Copyright © 2016 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

Biomechanical Changes in the Sclera of Monkey Eyes Exposed to Chronic IOP Elevations

PubMed Central

Girard, Michaël J. A.; Suh, J.-K. Francis; Bottlang, Michael; Burgoyne, Claude F.

2011-01-01

Purpose. To characterize scleral biomechanics in both eyes of eight monkeys in which chronic intraocular pressure (IOP) elevation was induced in one eye. Methods. Each posterior sclera was mounted on a pressurization apparatus, IOP was elevated from 5 to 45 mm Hg while the 3D displacements of the scleral surface were measured by speckle interferometry. Finite element (FE) models of each scleral shell were constructed that incorporated stretch-induced stiffening and multidirectionality of the collagen fibers. FE model predictions were then iteratively matched to experimental displacements to extract unique sets of scleral biomechanical properties. Results. For all eyes, the posterior sclera exhibited inhomogeneous, anisotropic, nonlinear biomechanical behavior. Biomechanical changes caused by chronic IOP elevation were complex and specific to each subject. Specifically: (1) Glaucomatous eyes in which the contralateral normal eyes displayed large modulus or thickness were less prone to biomechanical changes; (2) glaucomatous scleral modulus associated with an IOP of 10 mm Hg decreased (when compared with that of the contralateral normal) after minimal chronic IOP elevation; (3) glaucomatous scleral modulus associated with IOPs of 30 and 45 mm Hg increased (when compared with that of the contralateral normal) after moderate IOP elevation; and (4) FE-based estimates of collagen fiber orientation demonstrated no change in the glaucomatous eyes. Conclusions. Significant stiffening of the sclera follows exposure to moderate IOP elevations in most eyes. Scleral hypercompliance may precede stiffening or be a unique response to minimal chronic IOP elevation in some eyes. These biomechanical changes are likely to be the result of scleral extracellular matrix remodeling. PMID:21519033

Eye coding mechanisms in early human face event-related potentials.

PubMed

Rousselet, Guillaume A; Ince, Robin A A; van Rijsbergen, Nicola J; Schyns, Philippe G

2014-11-10

In humans, the N170 event-related potential (ERP) is an integrated measure of cortical activity that varies in amplitude and latency across trials. Researchers often conjecture that N170 variations reflect cortical mechanisms of stimulus coding for recognition. Here, to settle the conjecture and understand cortical information processing mechanisms, we unraveled the coding function of N170 latency and amplitude variations in possibly the simplest socially important natural visual task: face detection. On each experimental trial, 16 observers saw face and noise pictures sparsely sampled with small Gaussian apertures. Reverse-correlation methods coupled with information theory revealed that the presence of the eye specifically covaries with behavioral and neural measurements: the left eye strongly modulates reaction times and lateral electrodes represent mainly the presence of the contralateral eye during the rising part of the N170, with maximum sensitivity before the N170 peak. Furthermore, single-trial N170 latencies code more about the presence of the contralateral eye than N170 amplitudes and early latencies are associated with faster reaction times. The absence of these effects in control images that did not contain a face refutes alternative accounts based on retinal biases or allocation of attention to the eye location on the face. We conclude that the rising part of the N170, roughly 120-170 ms post-stimulus, is a critical time-window in human face processing mechanisms, reflecting predominantly, in a face detection task, the encoding of a single feature: the contralateral eye. © 2014 ARVO.

Effect of optic neuritis on progressive axonal damage in multiple sclerosis patients.

PubMed

Garcia-Martin, E; Pueyo, V; Ara, J R; Almarcegui, C; Martin, J; Pablo, L; Dolz, I; Sancho, E; Fernandez, F J

2011-07-01

The objective of this research was to study the effect of optic neuritis (ON) on axonal damage in multiple sclerosis (MS) patients. Specifically, we compared changes over 2 years in the retinal nerve fibre layer (RNFL) between affected and contralateral eyes in MS patients with a prior history of ON. Thirty-four patients with one unilateral definitive episode of ON were included and underwent a complete ophthalmic examination, optical coherence tomography (OCT), scanning laser polarimetry, visual evoked potentials (VEP) and pattern electroretinogram (pERG). All patients were re-evaluated at 12 and 24 months. Parameters were compared between ON-affected and contralateral eyes in an initial exploration and over the course of the follow-up. Correlations between parameter changes were analysed. RNFL thickness and functional parameters showed more affection in ON eyes (p ≤ 0.05), but changes in measurements during the study were similar between both groups of eyes. Progressive axonal loss can be detected in the optic nerve, but ON is not a risk factor for increased chronic damage in MS patients without ophthalmic relapses. Loss of the RNFL is caused by progressive degeneration associated with the disease.

[Ocular hypotensive effect of alpha-adrenoceptor agonist and antagonist in the conscious pigmented rabbit].

PubMed

Moriwaki, Y; Iizuka, T; Nakamura, A; Nakata, K; Masaoka, Y; Ueda, T; Koide, R; Inatomi, M; Fukado, Y; Uchida, E

1992-02-01

It has been reported that some of the topically-used antiglaucomatics have a central ocular hypotensive effect. In this study, the influence of topical and intracerebroventricular (i.c.v.) administration of phenylephrine, clonidine, guanfacine, prazosin, yohimbine on the intraocular pressure (IOP) was investigated in the rabbit. Male pigmented rabbits were used throughout the experiments. For measurement of IOP, an applanation pneumatonograph was used. By unilateral topical administration of phenylephrine, an increase in IOP in the eye in which instillation was performed was observed. On the other hand, a slight decrease in IOP was observed by similar treatment of prazosin and yohimbine. No significant change of IOP in the contralateral eye was observed with these drugs. On the contrary, unilateral topical administration of clonidine or guanfacine decreased the IOP of both eyes. Furthermore, the decrease of IOP was more remarkable in the contralateral eye compared to the eye which received instillation. The IOP of both eyes was decreased in a dose-related fashion by i.c.v. administration of clonidine or guanfacine. The ocular hypotensive effects of clonidine were diminished by the pretreatment by i.c.v. administration with yohimbine. These results suggest that the ocular hypotensive effect of clonidine and guanfacine is due to their alpha 2-adrenoceptor stimulation in the central nervous system.

Horner's syndrome and contralateral abducens nerve palsy associated with zoster meningitis.

PubMed

Cho, Bum-Joo; Kim, Ji-Soo; Hwang, Jeong-Min

2013-12-01

A 55-year-old woman presented with diplopia following painful skin eruptions on the right upper extremity. On presentation, she was found to have 35 prism diopters of esotropia and an abduction limitation in the left eye. Two weeks later, she developed blepharoptosis and anisocoria with a smaller pupil in the right eye, which increased in the darkness. Cerebrospinal fluid analysis showed pleocytosis and a positive result for immunoglobulin G antibody to varicella zoster virus. She was diagnosed to have zoster meningitis with Horner's syndrome and contralateral abducens nerve palsy. After intravenous antiviral and steroid treatments, the vesicular eruptions and abducens nerve palsy improved. Horner's syndrome and diplopia resolved after six months. Here we present the first report of Horner's syndrome and contralateral abducens nerve palsy associated with zoster meningitis.

The use of self-inflating hydrogel expanders in pediatric patients with congenital microphthalmia in China.

PubMed

Hou, Zhijia; Yang, Qiong; Chen, Tao; Hao, Lei; Li, Yang; Li, Dongmei

2012-10-01

To report the results of enlarging orbital volume in consecutive cases of severe congenital microphthalmia by means of solid hydrophilic tissue expanders. The medical records of consecutive patients with congenital microphthalmia who underwent the placement of a hydrogel expander were retrospectively reviewed. Main outcome measures were orbital tissue expansion, prosthetic retention, and patient family satisfaction. A total of 17 patients were included in the study. All patients were able to retain an ocular prosthesis. The horizontal palpebral length increased from 71.3% of the contralateral unaffected eye to 85.4% of the contralateral unaffected eye. The expansion of orbital volume was assessed in seven patients. The volume of the microphthalmic orbits was expanded from 74.7% of the contralateral unaffected orbits to 83.5% of the contralateral unaffected orbits. Aesthetic results were satisfactory to both physicians and patient families. The following complications were noted in two patients: inferior migration of a spherical expander occurred in one case; a hemispheric expander was removed by the patient in another case. Hydrogel implants can successfully expand the dimensions of the conjunctival sac and the orbit in cases of severe congenital microphthalmia. Copyright © 2012 American Association for Pediatric Ophthalmology and Strabismus. Published by Mosby, Inc. All rights reserved.

The Relation of Ocular Surface Irregularity and Visual Disturbance in Early Stage Acanthamoeba Keratitis.

PubMed

Matsumoto, Yukihiro; Kodama, Asako; Goto, Eiki; Kawakita, Tetsuya; Dogru, Murat; Tsubota, Kazuo

2017-01-01

To evaluate the relation between ocular surface irregularity and visual disturbance in early stage Acanthamoeba keratitis (AK). Fifteen patients with culture-proven AK underwent routine ophthalmic examinations, including best-corrected visual acuity (BCVA) measurement, slitlamp biomicroscope examination, and corneal fluorescein dye staining test, in both the eyes. We also evaluated the corneal sensitivity with Cochet-Bonnet esthesiometer, tear functions by Schirmer's test, and ocular surface irregularity by corneal topography and compared the results with the contralateral healthy eyes in this study. The mean logarithm of the minimum angle of resolution BCVA (0.71±0.77) was significantly lower in the eyes with AK (P=0.002). Epithelial disorders were present in all eyes, and radial keratoneuritis in 14 eyes (93.3%). The mean corneal sensitivity (39.3±24.1 mm) was significantly lower in eyes with AK compared with the healthy eyes (P=0.005). The mean Schirmer's test value (22.5±12.0 mm) in eyes with AK was significantly higher compared with the healthy eyes (P=0.01). The ocular surface irregularity indices (the surface regularity index, 2.47±0.42; the surface asymmetry index, 3.24±1.31) were significantly higher in eyes with AK compared with contralateral healthy eyes (P<0.0001 and P<0.0001, respectively). The ocular surface disease in AK is associated with decrease in corneal sensitivity and increase in Schirmer's test value and ocular surface irregularity indices. The visual disturbance in AK may owe not only to corneal haze but also to ocular surface irregularity.

Transverse vs torsional ultrasound: prospective randomized contralaterally controlled study comparing two phacoemulsification-system handpieces.

PubMed

Assil, Kerry K; Harris, Lindsay; Cecka, Jeannie

2015-01-01

To compare surgical efficiency and multiple early clinical outcome variables in eyes undergoing phacoemulsification using either transversal or torsional ultrasound systems. Assil Eye Institute, Beverly Hills, CA, USA. Prospective, randomized, clinician-masked, contralaterally controlled single-center evaluation. Patients seeking cataract removal in both eyes with implantation of multifocal intraocular lenses were randomly assigned to one of two treatment rooms for phacoemulsification with either a transverse ultrasound system or torsional handpiece system. The contralateral eye was treated at a later date with the alternate device. A total of 54 eyes of 27 patients having similar degrees of cataract, astigmatism, and visual potential were included. All operative data were collected for analysis, and patients were followed for 3 months after surgery. Similar visual acuity was reported at all postoperative visits between the two groups. Mean phacoemulsification time and total power required were both significantly lower with the transverse system than with the torsional technique (P<0.05 for both). Similarly, mean total balanced salt solution used was significantly less with the transverse system vs torsional (P<0.05). Postoperative safety demonstrated significantly lower endothelial cell loss at 1 day and 1 month (P<0.05) with transverse vs torsional. Macular swelling was less at 1 week, 1 month, and 3 months with transverse vs torsional, although the difference did not achieve significance (P=0.1) at any single time point. Clinically detectable corneal edema was reported less frequently at all postoperative time points with the transverse system. The transverse ultrasound system was found to be possibly associated with less balanced salt-solution use, less phacoemulsification time, and less power required than the torsional phaco system. Postoperative data suggested that improved phaco efficiency may translate to a better overall safety profile for the patient.

Deletion of Ten-m3 Induces the Formation of Eye Dominance Domains in Mouse Visual Cortex

PubMed Central

Merlin, Sam; Horng, Sam; Marotte, Lauren R.; Sur, Mriganka; Sawatari, Atomu

2013-01-01

The visual system is characterized by precise retinotopic mapping of each eye, together with exquisitely matched binocular projections. In many species, the inputs that represent the eyes are segregated into ocular dominance columns in primary visual cortex (V1), whereas in rodents, this does not occur. Ten-m3, a member of the Ten-m/Odz/Teneurin family, regulates axonal guidance in the retinogeniculate pathway. Significantly, ipsilateral projections are expanded in the dorsal lateral geniculate nucleus and are not aligned with contralateral projections in Ten-m3 knockout (KO) mice. Here, we demonstrate the impact of altered retinogeniculate mapping on the organization and function of V1. Transneuronal tracing and c-fos immunohistochemistry demonstrate that the subcortical expansion of ipsilateral input is conveyed to V1 in Ten-m3 KOs: Ipsilateral inputs are widely distributed across V1 and are interdigitated with contralateral inputs into eye dominance domains. Segregation is confirmed by optical imaging of intrinsic signals. Single-unit recording shows ipsilateral, and contralateral inputs are mismatched at the level of single V1 neurons, and binocular stimulation leads to functional suppression of these cells. These findings indicate that the medial expansion of the binocular zone together with an interocular mismatch is sufficient to induce novel structural features, such as eye dominance domains in rodent visual cortex. PMID:22499796

Magnetic resonance imaging demonstrates compartmental muscle mechanisms of human vertical fusional vergence

PubMed Central

Clark, Robert A.

2015-01-01

Vertical fusional vergence (VFV) normally compensates for slight vertical heterophorias. We employed magnetic resonance imaging to clarify extraocular muscle contributions to VFV induced by monocular two-prism diopter (1.15°) base-up prism in 14 normal adults. Fusion during prism viewing requires monocular infraduction. Scans were repeated without prism, and with prism shifted contralaterally. Contractility indicated by morphometric indexes was separately analyzed in medial and lateral vertical rectus and superior oblique (SO) putative compartments, and superior and inferior horizontal rectus extraocular muscle putative compartments, but in the whole inferior oblique (IO). Images confirmed appropriate VFV that was implemented by the inferior rectus (IR) medial compartment contracting ipsilateral and relaxing contralateral to prism. There was no significant contractility in the IR lateral compartment. The superior but not inferior lateral rectus (LR) compartment contracted significantly in the prism viewing eye, but not contralateral to prism. The IO contracted ipsilateral but not contralateral to the prism. In the infraducting eye, the SO medial compartment relaxed significantly, while the lateral compartment was unchanged; contralateral to prism, the SO lateral compartment contracted, while the medial compartment was unchanged. There was no contractility in the superior or medial rectus muscles in either eye. There was no globe retraction. We conclude that the vertical component of VFV is primarily implemented by IR medial compartment contraction. Since appropriate vertical rotation is not directly implemented, or is opposed, by associated differential LR and SO compartmental activity, and IO contraction, these actions probably implement a torsional component of VFV. PMID:25589593

Safety and durability of effect of contralateral-eye administration of AAV2 gene therapy in patients with childhood-onset blindness caused by RPE65 mutations: a follow-on phase 1 trial.

PubMed

Bennett, Jean; Wellman, Jennifer; Marshall, Kathleen A; McCague, Sarah; Ashtari, Manzar; DiStefano-Pappas, Julie; Elci, Okan U; Chung, Daniel C; Sun, Junwei; Wright, J Fraser; Cross, Dominique R; Aravand, Puya; Cyckowski, Laura L; Bennicelli, Jeannette L; Mingozzi, Federico; Auricchio, Alberto; Pierce, Eric A; Ruggiero, Jason; Leroy, Bart P; Simonelli, Francesca; High, Katherine A; Maguire, Albert M

2016-08-13

Safety and efficacy have been shown in a phase 1 dose-escalation study involving a unilateral subretinal injection of a recombinant adeno-associated virus (AAV) vector containing the RPE65 gene (AAV2-hRPE65v2) in individuals with inherited retinal dystrophy caused by RPE65 mutations. This finding, along with the bilateral nature of the disease and intended use in treatment, prompted us to determine the safety of administration of AAV2-hRPE65v2 to the contralateral eye in patients enrolled in the phase 1 study. In this follow-on phase 1 trial, one dose of AAV2-hRPE65v2 (1.5 × 10(11) vector genomes) in a total volume of 300 μL was subretinally injected into the contralateral, previously uninjected, eyes of 11 children and adults (aged 11-46 years at second administration) with inherited retinal dystrophy caused by RPE65 mutations, 1.71-4.58 years after the initial subretinal injection. We assessed safety, immune response, retinal and visual function, functional vision, and activation of the visual cortex from baseline until 3 year follow-up, with observations ongoing. This study is registered with ClinicalTrials.gov, number NCT01208389. No adverse events related to the AAV were reported, and those related to the procedure were mostly mild (dellen formation in three patients and cataracts in two). One patient developed bacterial endophthalmitis and was excluded from analyses. We noted improvements in efficacy outcomes in most patients without significant immunogenicity. Compared with baseline, pooled analysis of ten participants showed improvements in mean mobility and full-field light sensitivity in the injected eye by day 30 that persisted to year 3 (mobility p=0.0003, white light full-field sensitivity p<0.0001), but no significant change was seen in the previously injected eyes over the same time period (mobility p=0.7398, white light full-field sensitivity p=0.6709). Changes in visual acuity from baseline to year 3 were not significant in pooled analysis in the second eyes or the previously injected eyes (p>0.49 for all time-points compared with baseline). To our knowledge, AAV2-hRPE65v2 is the first successful gene therapy administered to the contralateral eye. The results highlight the use of several outcome measures and help to delineate the variables that contribute to maximal benefit from gene augmentation therapy in this disease. Center for Cellular and Molecular Therapeutics at The Children's Hospital of Philadelphia, Spark Therapeutics, US National Institutes of Health, Foundation Fighting Blindness, Institute for Translational Medicine and Therapeutics, Research to Prevent Blindness, Center for Advanced Retinal and Ocular Therapeutics, Mackall Foundation Trust, F M Kirby Foundation, and The Research Foundation-Flanders. Copyright © 2016 Elsevier Ltd. All rights reserved.

Safety and durability of effect of contralateral-eye administration of AAV2 gene therapy in patients with childhood-onset blindness caused by RPE65 mutatons: a follow-on phase 1 trial

PubMed Central

Bennett, Jean; Wellman, Jennifer; Marshall, Kathleen A; McCague, Sarah; Ashtari, Manzar; DiStefano-Pappas, Julie; Elci, Okan U; Chung, Daniel C; Sun, Junwei; Wright, J Fraser; Cross, Dominique R; Aravand, Puya; Cyckowski, Laura L; Bennicelli, Jeannette L; Mingozzi, Federico; Auricchio, Alberto; Pierce, Eric A; Ruggiero, Jason; Leroy, Bart P; Simonelli, Francesca; High, Katherine A; Maguire, Albert M

2017-01-01

Summary Background Safety and efficacy have been shown in a phase 1 dose-escalation study involving a unilateral subretinal injection of a recombinant adeno-associated virus (AAV) vector containing the RPE65 gene (AAV2-hRPE65v2) in individuals with inherited retinal dystrophy caused by RPE65 mutations. This finding, along with the bilateral nature of the disease and intended use in treatment, prompted us to determine the safety of administration of AAV2-hRPE65v2 to the contralateral eye in patients enrolled in the phase 1 study. Methods In this follow-on phase 1 trial, one dose of AAV2-hRPE65v2 (1·5 × 1011 vector genomes) in a total volume of 300 μL was subretinally injected into the contralateral, previously uninjected, eyes of 11 children and adults (aged 11–46 years at second administration) with inherited retinal dystrophy caused by RPE65 mutations, 1·71–4·58 years after the initial subretinal injection. We assessed safety, immune response, retinal and visual function, functional vision, and activation of the visual cortex from baseline until 3 year follow-up, with observations ongoing. This study is registered with ClinicalTrials.gov, number NCT01208389. Findings No adverse events related to the AAV were reported, and those related to the procedure were mostly mild (dellen formation in three patients and cataracts in two). One patient developed bacterial endophthalmitis and was excluded from analyses. We noted improvements in efficacy outcomes in most patients without significant immunogenicity. Compared with baseline, pooled analysis of ten participants showed improvements in mean mobility and full-field light sensitivity in the injected eye by day 30 that persisted to year 3 (mobility p=0·0003, white light full-field sensitivity p<0·0001), but no significant change was seen in the previously injected eyes over the same time period (mobility p=0·7398, white light full-field sensitivity p=0·6709). Changes in visual acuity from baseline to year 3 were not significant in pooled analysis in the second eyes or the previously injected eyes (p>0·49 for all time-points compared with baseline). Interpretation To our knowledge, AAV2-hRPE65v2 is the first successful gene therapy administered to the contralateral eye. The results highlight the use of several outcome measures and help to delineate the variables that contribute to maximal benefit from gene augmentation therapy in this disease. Funding Center for Cellular and Molecular Therapeutics at The Children’s Hospital of Philadelphia, Spark Therapeutics, US National Institutes of Health, Foundation Fighting Blindness, Institute for Translational Medicine and Therapeutics, Research to Prevent Blindness, Center for Advanced Retinal and Ocular Therapeutics, Mackall Foundation Trust, F M Kirby Foundation, and The Research Foundation—Flanders. PMID:27375040

Identification of Eye-Specific Domains and Their Relation to Callosal Connections in Primary Visual Cortex of Long Evans Rats

PubMed Central

Laing, R.J.; Turecek, J.; Takahata, T.; Olavarria, J.F.

2015-01-01

Ocular dominance columns (ODCs) exist in many primates and carnivores, but it is believed that they do not exist in rodents. Using a combination of transneuronal tracing, in situ hybridization for Zif268 and electrophysiological recordings, we show that inputs from both eyes are largely segregated in the binocular region of V1 in Long Evans rats. We also show that, interposed between this binocular region and the lateral border of V1, there lies a strip of cortex that is strongly dominated by the contralateral eye. Finally, we show that callosal connections colocalize primarily with ipsilateral eye domains in the binocular region and with contralateral eye input in the lateral cortical strip, mirroring the relationship between patchy callosal connections and specific sets of ODCs described previously in the cat. Our results suggest that development of cortical modular architecture is more conserved among rodents, carnivores, and primates than previously thought. PMID:24969475

Frontal Eye Fields Control Attentional Modulation of Alpha and Gamma Oscillations in Contralateral Occipitoparietal Cortex

PubMed Central

O'Shea, Jacinta; Jensen, Ole; Bergmann, Til O.

2015-01-01

Covertly directing visuospatial attention produces a frequency-specific modulation of neuronal oscillations in occipital and parietal cortices: anticipatory alpha (8–12 Hz) power decreases contralateral and increases ipsilateral to attention, whereas stimulus-induced gamma (>40 Hz) power is boosted contralaterally and attenuated ipsilaterally. These modulations must be under top-down control; however, the control mechanisms are not yet fully understood. Here we investigated the causal contribution of the human frontal eye field (FEF) by combining repetitive transcranial magnetic stimulation (TMS) with subsequent magnetoencephalography. Following inhibitory theta burst stimulation to the left FEF, right FEF, or vertex, participants performed a visual discrimination task requiring covert attention to either visual hemifield. Both left and right FEF TMS caused marked attenuation of alpha modulation in the occipitoparietal cortex. Notably, alpha modulation was consistently reduced in the hemisphere contralateral to stimulation, leaving the ipsilateral hemisphere relatively unaffected. Additionally, right FEF TMS enhanced gamma modulation in left visual cortex. Behaviorally, TMS caused a relative slowing of response times to targets contralateral to stimulation during the early task period. Our results suggest that left and right FEF are causally involved in the attentional top-down control of anticipatory alpha power in the contralateral visual system, whereas a right-hemispheric dominance seems to exist for control of stimulus-induced gamma power. These findings contrast the assumption of primarily intrahemispheric connectivity between FEF and parietal cortex, emphasizing the relevance of interhemispheric interactions. The contralaterality of effects may result from a transient functional reorganization of the dorsal attention network after inhibition of either FEF. PMID:25632139

Comparison of efficacy and safety of laser in situ keratomileusis using 2 femtosecond laser platforms in contralateral eyes.

PubMed

Rosman, Mohamad; Hall, Reece C; Chan, Cordelia; Ang, Andy; Koh, Jane; Htoon, Hla Myint; Tan, Donald T H; Mehta, Jodhbir S

2013-07-01

To compare the efficacy, predictability, and refractive outcomes of laser in situ keratomileusis (LASIK) using 2 femtosecond platforms for flap creation. Multisurgeon single center. Clinical trial. Bilateral femtosecond LASIK was performed using the Wavelight Allegretto Eye-Q 400 Hz excimer laser system. The Visumax femtosecond platform (Group 1) was used to create the LASIK flap in 1 eye, while the Intralase femtosecond platform (Group 2) was used to create the LASIK flap in the contralateral eye. The preoperative, 1-month, and 3-month postoperative visual acuities, refraction, and contrast sensitivity in the 2 groups were compared. The study enrolled 45 patients. Three months after femtosecond LASIK, 79.5% of eyes in Group 1 and 82.1% in Group 2 achieved an uncorrected distance visual acuity of 20/20 (P=.808). The mean efficacy index was 0.97 in Group 1 and 0.98 in Group 2 at 3 months (P=.735); 89.7% of eyes in Group 1 and 84.6% of eyes in Group 2 were within ± 0.50 diopter of emmetropia at 3 months (P=.498). No eye in either group lost more than 2 lines of corrected distance visual acuity. The mean safety index at 3 months was 1.11 in Group 1 and 1.10 in Group 2 (P=.570). The results of LASIK with both femtosecond lasers were similar, and both platforms produced efficacious and predictable LASIK outcomes. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Longitudinal measurements of luminance and chromatic contrast sensitivity: comparison between wavefront-guided LASIK and contralateral PRK for myopia.

PubMed

Barboni, Mirella Telles Salgueiro; Feitosa-Santana, Claudia; Barreto Junior, Jackson; Lago, Marcos; Bechara, Samir Jacob; Alves, Milton Ruiz; Ventura, Dora Fix

2013-10-01

The present study aimed to compare the postoperative contrast sensitivity functions between wavefront-guided LASIK eyes and their contralateral wavefront-guided PRK eyes. The participants were 11 healthy subjects (mean age=32.4 ± 6.2 years) who had myopic astigmatism. The spatial contrast sensitivity functions were measured before and three times after the surgery. Psycho and a Cambridge graphic board (VSG 2/4) were used to measure luminance, red-green, and blue-yellow spatial contrast sensitivity functions (from 0.85 to 13.1 cycles/degree). Longitudinal analysis and comparison between surgeries were performed. There was no significant contrast sensitivity change during the one-year follow-up measurements neither for LASIK nor for PRK eyes. The comparison between procedures showed no differences at 12 months postoperative. The present data showed similar contrast sensitivities during one-year follow-up of wave-front guided refractive surgeries. Moreover, one year postoperative data showed no differences in the effects of either wavefront-guided LASIK or wavefront-guided PRK on the luminance and chromatic spatial contrast sensitivity functions.

Frontal eye fields control attentional modulation of alpha and gamma oscillations in contralateral occipitoparietal cortex.

PubMed

Marshall, Tom R; O'Shea, Jacinta; Jensen, Ole; Bergmann, Til O

2015-01-28

Covertly directing visuospatial attention produces a frequency-specific modulation of neuronal oscillations in occipital and parietal cortices: anticipatory alpha (8-12 Hz) power decreases contralateral and increases ipsilateral to attention, whereas stimulus-induced gamma (>40 Hz) power is boosted contralaterally and attenuated ipsilaterally. These modulations must be under top-down control; however, the control mechanisms are not yet fully understood. Here we investigated the causal contribution of the human frontal eye field (FEF) by combining repetitive transcranial magnetic stimulation (TMS) with subsequent magnetoencephalography. Following inhibitory theta burst stimulation to the left FEF, right FEF, or vertex, participants performed a visual discrimination task requiring covert attention to either visual hemifield. Both left and right FEF TMS caused marked attenuation of alpha modulation in the occipitoparietal cortex. Notably, alpha modulation was consistently reduced in the hemisphere contralateral to stimulation, leaving the ipsilateral hemisphere relatively unaffected. Additionally, right FEF TMS enhanced gamma modulation in left visual cortex. Behaviorally, TMS caused a relative slowing of response times to targets contralateral to stimulation during the early task period. Our results suggest that left and right FEF are causally involved in the attentional top-down control of anticipatory alpha power in the contralateral visual system, whereas a right-hemispheric dominance seems to exist for control of stimulus-induced gamma power. These findings contrast the assumption of primarily intrahemispheric connectivity between FEF and parietal cortex, emphasizing the relevance of interhemispheric interactions. The contralaterality of effects may result from a transient functional reorganization of the dorsal attention network after inhibition of either FEF. Copyright © 2015 the authors 0270-6474/15/351638-10$15.00/0.

Effect of 0.4% benoxinate hydrochloride on corneal sensitivity, measured using the non-contact corneal aesthesiometer (NCCA).

PubMed

Murphy, P J; Blades, K J; Patel, S

1997-12-01

The Non-Contact Corneal Aesthesiometer (NCCA) was used to monitor the effect of topical anesthesia on corneal sensitivity loss and recovery. In a single masked randomized study, one drop of nonpreserved 0.4% benoxinate hydrochloride was instilled in either the right, left, or both eyes of 20 subjects on separate days, and measurements were made of the central corneal sensitivity in the right eye over a 60-min period. As controls, 10 subjects were retested, without any anesthetic instillation, over the same time period. No significant differences were found between these two benoxinate treatments, nor between the contralateral treatment and controls. Results indicate that there is no contralateral effect of benoxinate anesthesia, and that full recovery does not occur until 60 min after instillation. No effect on the depth and duration of anesthesia was found for iris color.

Identification of Eye-Specific Domains and Their Relation to Callosal Connections in Primary Visual Cortex of Long Evans Rats.

PubMed

Laing, R J; Turecek, J; Takahata, T; Olavarria, J F

2015-10-01

Ocular dominance columns (ODCs) exist in many primates and carnivores, but it is believed that they do not exist in rodents. Using a combination of transneuronal tracing, in situ hybridization for Zif268 and electrophysiological recordings, we show that inputs from both eyes are largely segregated in the binocular region of V1 in Long Evans rats. We also show that, interposed between this binocular region and the lateral border of V1, there lies a strip of cortex that is strongly dominated by the contralateral eye. Finally, we show that callosal connections colocalize primarily with ipsilateral eye domains in the binocular region and with contralateral eye input in the lateral cortical strip, mirroring the relationship between patchy callosal connections and specific sets of ODCs described previously in the cat. Our results suggest that development of cortical modular architecture is more conserved among rodents, carnivores, and primates than previously thought. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Transverse vs torsional ultrasound: prospective randomized contralaterally controlled study comparing two phacoemulsification-system handpieces

PubMed Central

Assil, Kerry K; Harris, Lindsay; Cecka, Jeannie

2015-01-01

Purpose To compare surgical efficiency and multiple early clinical outcome variables in eyes undergoing phacoemulsification using either transversal or torsional ultrasound systems. Setting Assil Eye Institute, Beverly Hills, CA, USA. Design Prospective, randomized, clinician-masked, contralaterally controlled single-center evaluation. Patients and methods Patients seeking cataract removal in both eyes with implantation of multifocal intraocular lenses were randomly assigned to one of two treatment rooms for phacoemulsification with either a transverse ultrasound system or torsional handpiece system. The contralateral eye was treated at a later date with the alternate device. A total of 54 eyes of 27 patients having similar degrees of cataract, astigmatism, and visual potential were included. All operative data were collected for analysis, and patients were followed for 3 months after surgery. Results Similar visual acuity was reported at all postoperative visits between the two groups. Mean phacoemulsification time and total power required were both significantly lower with the transverse system than with the torsional technique (P<0.05 for both). Similarly, mean total balanced salt solution used was significantly less with the transverse system vs torsional (P<0.05). Postoperative safety demonstrated significantly lower endothelial cell loss at 1 day and 1 month (P<0.05) with transverse vs torsional. Macular swelling was less at 1 week, 1 month, and 3 months with transverse vs torsional, although the difference did not achieve significance (P=0.1) at any single time point. Clinically detectable corneal edema was reported less frequently at all postoperative time points with the transverse system. Conclusion The transverse ultrasound system was found to be possibly associated with less balanced salt-solution use, less phacoemulsification time, and less power required than the torsional phaco system. Postoperative data suggested that improved phaco efficiency may translate to a better overall safety profile for the patient. PMID:26345628

Degree of corneal anesthesia after topical application of 0.4% oxybuprocaine ophthalmic solution in normal equids.

PubMed

Little, Erika; Yvorchuk-St Jean, Kathy; Little, William; Sithole, Fortune; St Jean, Guy

2016-10-01

Oxybuprocaine hydrochloride ophthalmic solution has been widely used off-label in horses and donkeys, despite lack of data demonstrating efficacy and safety in these species. The objective of this study was to assess anesthetic efficacy of 0.4% oxybuprocaine hydrochloride ophthalmic solution in horses ( n = 5) and donkeys ( n = 24) and compare the effects with 0.5% proparacaine hydrochloride ophthalmic solution. The baseline corneal touch threshold (CTT) was measured with a Cochet-Bonnet esthesiometer. Donkeys ( n = 12) and horses ( n = 5) in group A received sterile ophthalmic solutions 0.4% oxybuprocaine with fluorescein (also termed benoxinate with fluorescein, abbreviated as ben + flu) instilled in one eye and 0.9% sterile sodium chloride solution (NaCl) with fluorescein (Na + flu) in the contralateral eye. Donkeys ( n = 12) and horses ( n = 5) in group B received sterile ophthalmic solutions (ben + flu) in one eye and 0.5% proparacaine with fluorescein (prop + flu) in the contralateral eye. The CTT was measured at 1 and 5 min post-application and at 5-minute intervals until 75 min after treatment. The CTT changes over time differed significantly between oxybuprocaine-treated and control eyes ( P < 0.001). The CTT continued to decrease throughout the duration of the study when compared with baseline values. No statistically significant difference in onset, depth, or duration of corneal anesthesia was found between oxybuprocaine and proparacaine treated eyes during the time of the study. Interestingly, horses were shown to have a significantly more sensitive cornea than donkeys ( P = 0.002). Oxybuprocaine and proparacaine reduced corneal sensitivity in donkeys and horses. No local irritation was observed with 0.4% oxybuprocaine.

Degree of corneal anesthesia after topical application of 0.4% oxybuprocaine ophthalmic solution in normal equids

PubMed Central

Little, Erika; Yvorchuk-St. Jean, Kathy; Little, William; Sithole, Fortune; St. Jean, Guy

2016-01-01

Oxybuprocaine hydrochloride ophthalmic solution has been widely used off-label in horses and donkeys, despite lack of data demonstrating efficacy and safety in these species. The objective of this study was to assess anesthetic efficacy of 0.4% oxybuprocaine hydrochloride ophthalmic solution in horses (n = 5) and donkeys (n = 24) and compare the effects with 0.5% proparacaine hydrochloride ophthalmic solution. The baseline corneal touch threshold (CTT) was measured with a Cochet-Bonnet esthesiometer. Donkeys (n = 12) and horses (n = 5) in group A received sterile ophthalmic solutions 0.4% oxybuprocaine with fluorescein (also termed benoxinate with fluorescein, abbreviated as ben + flu) instilled in one eye and 0.9% sterile sodium chloride solution (NaCl) with fluorescein (Na + flu) in the contralateral eye. Donkeys (n = 12) and horses (n = 5) in group B received sterile ophthalmic solutions (ben + flu) in one eye and 0.5% proparacaine with fluorescein (prop + flu) in the contralateral eye. The CTT was measured at 1 and 5 min post-application and at 5-minute intervals until 75 min after treatment. The CTT changes over time differed significantly between oxybuprocaine-treated and control eyes (P < 0.001). The CTT continued to decrease throughout the duration of the study when compared with baseline values. No statistically significant difference in onset, depth, or duration of corneal anesthesia was found between oxybuprocaine and proparacaine treated eyes during the time of the study. Interestingly, horses were shown to have a significantly more sensitive cornea than donkeys (P = 0.002). Oxybuprocaine and proparacaine reduced corneal sensitivity in donkeys and horses. No local irritation was observed with 0.4% oxybuprocaine. PMID:27733789

Discharge properties of Purkinje cells in the oculomotor vermis during visually guided saccades in the macaque monkey.

PubMed

Ohtsuka, K; Noda, H

1995-11-01

1. We previously described discharge properties of cerebellar output cells in the fastigial nucleus during ipsilateral and contralateral saccades. Fastigial cells exhibited unique responses depending on the direction of saccades and were involved in execution of accurate targeting saccades. Purkinje cells in the oculomotor vermis (lobules VIc and VII) are thought to modulate these discharges of fastigial cells. In this study we reexamine discharge properties of Purkinje cells on the basis of this hypothesis. 2. Initially we physiologically identified the right and left sides of the oculomotor vermis. Saccade-related discharges of 79 Purkinje cells were recorded from both sides of the vermis during visually guided saccades toward the sides ipsilateral and contralateral to the recording side in two trained macaque monkeys. To clarify the correlation of Purkinje cell discharge with burst activities in the fastigial nucleus during saccadic eye movements, we analyzed our data by employing methods used in the study of fastigial neurons. 3. Among the 79 cells, 56 (71%) showed burst discharges during saccades (saccadic burst cells). Of the 56 cells, 29 exhibited a peak of burst discharges in both the contralateral and ipsilateral directions (bidirectional cells). The remaining 27 saccadic burst cells showed a peak of burst discharges during either contralateral or ipsilateral saccades (unidirectional cells). Among the 79 cells, 14 (18%) exhibited a pause of discharges during contralateral saccades (pause cells). Among the 79 cells, 9 (11%) showed burst discharge during contralateral saccades followed by tonic discharge that was correlated with eye position (burst tonic cells). 4. The timing of bursts in bidirectional cells with respect to saccade onset was dependent on the direction of saccade. During ipsilateral saccades, Purkinje cells exhibited a long lead burst that built up gradually, peaked near the onset of the saccade, and terminated sharply near midsaccade. The mean lead time relative to saccade onset was 29.3 +/- 24.5 (SD) ms. During contralateral saccades, Purkinje cells exhibited a short lead/late burst that built up sharply, peaked near midsaccade, and terminated gradually after the end of the saccade. The mean lead time relative to saccade onset was 10.7 +/- 20.8 ms. The burst onset time during contralateral saccades and the burst offset time during ipsilateral saccades preceded the saccade offset time by about the same interval regardless of the saccade amplitude. 5. In pause cells the pause preceded saccade onset by 17.5 +/- 10.6 ms. The duration of the pause was not correlated with the duration of saccades. There was little trial-to-trial variability in the onset time of the pause with respect to the onset of saccades, whereas there was large trial-to-trial variability in the offset time of the pause with respect to the offset of saccades. In addition, the mean onset time of the pause for each cell had a relatively narrow distribution. 6. The burst lead time of burst tonic cells relative to saccade onset was 9.5 +/- 3.9 ms. The tonic discharge rate of burst tonic cells was a nonlinear function of eye position. The regression of each cell was fit to two lines. The regression coefficient ranged from 0.95 to 0.99 (mean = 0.97). 7. Axons of Purkinje cells in the oculomotor vermis are thought to project exclusively to saccadic burst cells in the fastigial oculomotor region (FOR), which is located in the caudal portion of the fastigial nucleus. Our previous studies indicated that FOR cells provide temporal signals for controlling targeting saccades. The present results suggest that Purkinje cells in the oculomotor vermis modify the temporal signals of FOR cells for saccades in different directions and amplitudes. The modification of FOR cell activity by Purkinje cells is thought to be essential for the function of the cerebellum in the control of saccadic eye movements.

Posterior Vitreous Detachment With Microplasmin Alters the Retinal Penetration of Intravitreal Bevacizumab (Avastin) in Rabbit Eyes

PubMed Central

Goldenberg, David T.; Giblin, Frank J.; Cheng, Mei; Chintala, Shravan K.; Trese, Michael T.; Drenser, Kimberly A.; Ruby, Alan J.

2010-01-01

Purpose Intravitreal bevacizumab (Avastin) is frequently used for the treatment of age-related macular degeneration. Previous studies have demonstrated full thickness retinal penetration. Intravitreal recombinant microplasmin (MP) has been shown to successfully induce a posterior vitreous detachment (PVD) and vitreous liquefaction in animals. It has been suggested that a PVD may alter the retinal penetration of molecules in the vitreous cavity. The aim of this study was to compare bevacizumab (BV) retinal penetration in rabbit eyes with and without a MP-induced PVD. Methods Twelve adult rabbits were injected with 0.1 ml (0.4 mg) of MP into the vitreous cavity of one eye. One week later, the rabbits were injected with 0.05 ml (1.25 mg) of BV into both eyes. Both eyes of three rabbits each were harvested at 6, 12, 24, and 72 hours after the BV injection. Frozen retinal cross sections were prepared, and BV retinal penetration was evaluated with immunohistochemistry using a fluorescence-labeled antibody against BV. Two eyes from one rabbit were not injected with either agent and used as controls to compare the background autofluorescence. Peripapillary retinal sections were recorded with a digital camera, and intra-retinal BV fluorescence-labeled antibody was measured by qualitative photographic interpretation. Two additional rabbits received an intravitreal injection of 0.1 ml of MP in one eye. One week later, both eyes from each rabbit were enucleated and frozen retinal sections were prepared and analyzed with light microscopy to evaluate for histologic damage. Results Full thickness BV retinal penetration was observed throughout the retina in both eyes of each rabbit. All of the MP-injected eyes exhibited increased antibody labeling in retinas evaluated 6, 12, and 24 hours after BV injection when compared with the contralateral non-MP-injected eyes. By three days after BV injection, all eyes demonstrated decreased antibody labeling compared to earlier time periods. At three days, one rabbit showed increased antibody labeling in the retina of the non-MP-injected eye compared with the contralateral MP-injected eye, and two rabbits exhibited similar antibody labeling in both eyes. When compared with control eyes, light microscopy demonstrated normal retinal histologic findings in eyes injected only with microplasmin. Conclusions Increased BV retinal penetration is observed initially in eyes with a MP-induced PVD, and the mechanism is likely multifactorial. By three days, retinal penetration is similar in eyes with and without a PVD. Although it is difficult to directly extrapolate to humans, our study suggests a PVD may alter the retinal penetration of BV. PMID:21099453

Outcomes of topography-guided versus wavefront-optimized laser in situ keratomileusis for myopia in virgin eyes.

PubMed

Jain, Arun Kumar; Malhotra, Chintan; Pasari, Anand; Kumar, Pawan; Moshirfar, Majid

2016-09-01

To compare the outcomes of topography-guided and wavefront-optimized treatment in patients having laser in situ keratomileusis (LASIK) for myopia. Advanced Eye Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India. Prospective contralateral-eye case study. Patients had topography-guided LASIK in 1 eye and wavefront-optimized LASIK in the contralateral eye using the Customized Refractive Surgery Master software and Mel 80 excimer laser. Refractive (residual manifest refraction spherical equivalent [MRSE], higher-order aberrations [HOAs]), and visual (uncorrected distance visual acuity [UDVA] and photopic and mesopic contrast sensitivity) outcomes were prospectively analyzed 6 months postoperatively. The study comprised 35 patients. The UDVA was 0.0 logMAR or better and the postoperative residual MRSE was ±0.50 diopter in 94.29% of eyes in the topography-guided group and 85.71% of eyes in the wavefront-optimized group (P = .09). More eyes in the topography-guided group than in the wavefront-optimized group had a UDVA of -0.1 logMAR or better (P = .04). Topography-guided LASIK was associated with less deterioration of mesopic contrast sensitivity at higher spatial frequencies (12 cycles per degree [cpd] and 18 cpd) and lower amounts of induced coma (P = .04) and spherical aberration (P = .04). Less stromal tissue was ablated in the topography-guided group (mean 61.57 μm ± 16.23 [SD]) than in the wavefront-optimized group (mean 79.71 ± 14.81 μm) (P < .001). Although topography-guided LASIK and wavefront-optimized LASIK gave excellent results, topography-guided LASIK was associated with better contrast sensitivity, lower induction of HOAs, and a smaller amount of tissue ablation. None of the authors has a financial or proprietary interest in any material or method mentioned. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Degree and duration of corneal anesthesia after topical application of 0.4% oxybuprocaine hydrochloride ophthalmic solution in ophthalmically normal dogs.

PubMed

Douet, Jean-Yves; Michel, Julien; Regnier, Alain

2013-10-01

To assess the anesthetic efficacy and local tolerance of topically applied 0.4% oxybuprocaine ophthalmic solution to in dogs and compare its effects with those of 1% tetracaine solution. 34 ophthalmically normal Beagles. Dogs were assigned to 2 groups, and baseline corneal touch threshold (CTT) was measured bilaterally with a Cochet-Bonnet aesthesiometer. Dogs of group 1 (n = 22) received a single drop of 0.4% oxybuprocaine ophthalmic solution in one eye and saline (0.9% NaCl) solution (control treatment) in the contralateral eye. Dogs of group 2 (n = 12) received a single drop of 0.4% oxybuprocaine ophthalmic solution in one eye and 1% tetracaine ophthalmic solution in the contralateral eye. The CTT of each eye was measured 1 and 5 minutes after topical application and then at 5-minute intervals until 75 minutes after topical application. CTT changes over time differed significantly between oxybuprocaine-treated and control eyes. After instillation of oxybuprocaine, maximal corneal anesthesia (CTT = 0) was achieved within 1 minute, and CTT was significantly decreased from 1 to 45 minutes, compared with the baseline value. No significant difference in onset, depth, and duration of corneal anesthesia was found between oxybuprocaine-treated and tetracaine-treated eyes. Conjunctival hyperemia and chemosis were detected more frequently in tetracaine-treated eyes than in oxybuprocaine-treated eyes. Topical application of oxybuprocaine and tetracaine similarly reduced corneal sensitivity in dogs, but oxybuprocaine was less irritating to the conjunctiva than was tetracaine.

Intraoperative aberrometry versus standard preoperative biometry and a toric IOL calculator for bilateral toric IOL implantation with a femtosecond laser: One-month results.

PubMed

Woodcock, Michael G; Lehmann, Robert; Cionni, Robert J; Breen, Michael; Scott, Maria C

2016-06-01

To compare astigmatic outcomes in patients with bilateral cataracts having toric intraocular lens (IOL) implantation with intraoperative aberrometry measurements in 1 eye and standard power calculation and a toric IOL calculator with inked axis marking in the contralateral eye. Twelve sites in the United States. Prospective cohort study. The eye with the more visually significant cataract was randomized to intraoperative aberrometry measurements (Ocular Response Analyzer with Verifeye) or standard preoperative biometry and use of a toric calculator with the contralateral eye automatically assigned to the other group. The primary effectiveness outcome was the proportion of eyes with a postoperative refractive astigmatism of 0.50 diopter (D) or less at 1 month. Of the 130 patients (260 eyes) enrolled, 124 (248 eyes) were randomized; 121 (242 eyes) completed the trial. The percentage of eyes with astigmatism of 0.50 D or less at 1 month was higher in the intraoperative aberrometry group than in the standard group (89.2% versus 76.6%) (P = .006). The mean postoperative refractive astigmatism was lower in the intraoperative aberrometry group (0.29 D ± 0.28 [SD] versus 0.36 ± 0.35 D) (P = .041). Secondary effectiveness endpoints, including manifest refraction spherical equivalent prediction error, uncorrected distance visual acuity, and corrected distance visual acuity, were similar. Compared with standard methods, the use of the intraoperative aberrometry system increased the proportion of eyes with postoperative refractive astigmatism of 0.50 D or less and reduced the mean postoperative refractive astigmatism at 1 month. Other efficacy outcomes were similar. Drs. Woodcock, Lehmann, and Cionni are consultants to Alcon Laboratories, Inc. Dr. Breen is an employee of Alcon Laboratories, Inc. Dr. Scott has no financial or proprietary interest in any material or method mentioned. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Custom vs conventional PRK: a prospective, randomized, contralateral eye comparison of postoperative visual function.

PubMed

Mifflin, Mark D; Hatch, Bryndon B; Sikder, Shameema; Bell, James; Kurz, Christopher J; Moshirfar, Majid

2012-02-01

To determine whether VISX S4 (VISX Inc) custom photorefractive keratectomy (PRK) results in better visual outcomes than VISX S4 conventional PRK. Photorefractive keratectomy was performed on 80 eyes from 40 patients in this randomized, prospective, contralateral eye study. Dominant eyes were randomized to one group with the fellow eye receiving the alternate treatment. Primary outcome measures included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), contrast sensitivity, and root-mean-square (RMS) higher order aberrations. Mean UDVA was -0.023±0.099 (20/19) in the custom group and -0.044±0.080 (20/18) in the conventional group 6 months after surgery (P=.293). Mean CDVA was -0.073±0.067 (20/17) in the custom group and -0.079±0.071 (20/17) in the conventional group 6 months after surgery (P=.659). Total higher order aberration RMS and spherical aberration increased in both groups compared to preoperative values (P<.05). Coma increased in the conventional group (P<.05) whereas it was similar to preoperative values in the custom group. No significant differences were noted in induction of trefoil. Custom and conventional PRK were shown to be safe and effective with excellent visual acuity and contrast sensitivity performance at 6 and 12 months. Conventional PRK induced more coma than custom PRK; however, this did not seem to correlate with clinical outcomes. Copyright 2012, SLACK Incorporated.

A prospective, contralateral comparison of photorefractive keratectomy (PRK) versus thin-flap LASIK: assessment of visual function.

PubMed

Hatch, Bryndon B; Moshirfar, Majid; Ollerton, Andrew J; Sikder, Shameema; Mifflin, Mark D

2011-01-01

To compare differences in visual acuity, contrast sensitivity, complications, and higher-order ocular aberrations (HOAs) in eyes with stable myopia undergoing either photo-refractive keratectomy (PRK) or thin-flap laser in situ keratomileusis (LASIK) (intended flap thickness of 90 μm) using the VISX Star S4 CustomVue excimer laser and the IntraLase FS60 femtosecond laser at 1, 3, and 6 months postoperatively. In this prospective, masked, and randomized pilot study, refractive surgery was performed contralaterally on 52 eyes: 26 with PRK and 26 with thin-flap LASIK. Primary outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), contrast sensitivity, and complications. At 6 months, mean values for UDVA (logMAR) were -0.043 ± 0.668 and -0.061 ± 0.099 in the PRK and thin-flap LASIK groups, respectively (n = 25, P = 0.466). UDVA of 20/20 or better was achieved in 96% of eyes undergoing PRK and 92% of eyes undergoing thin-flap LASIK, whereas 20/15 vision or better was achieved in 73% of eyes undergoing PRK and 72% of eyes undergoing thin-flap LASIK (P > 0.600). Significant differences were not found between treatment groups in contrast sensitivity (P ≥ 0.156) or CDVA (P = 0.800) at postoperative 6 months. Types of complications differed between groups, notably 35% of eyes in the thin-flap LASIK group experiencing complications, including microstriae and 2 flap tears. Under well-controlled surgical conditions, PRK and thin-flap LASIK refractive surgeries achieve similar results in visual acuity, contrast sensitivity, and induction of HOAs, with differences in experienced complications.

A prospective, contralateral comparison of photorefractive keratectomy (PRK) versus thin-flap LASIK: assessment of visual function

PubMed Central

Hatch, Bryndon B; Moshirfar, Majid; Ollerton, Andrew J; Sikder, Shameema; Mifflin, Mark D

2011-01-01

Purpose: To compare differences in visual acuity, contrast sensitivity, complications, and higher-order ocular aberrations (HOAs) in eyes with stable myopia undergoing either photo-refractive keratectomy (PRK) or thin-flap laser in situ keratomileusis (LASIK) (intended flap thickness of 90 μm) using the VISX Star S4 CustomVue excimer laser and the IntraLase FS60 femtosecond laser at 1, 3, and 6 months postoperatively. Methods: In this prospective, masked, and randomized pilot study, refractive surgery was performed contralaterally on 52 eyes: 26 with PRK and 26 with thin-flap LASIK. Primary outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), contrast sensitivity, and complications. Results: At 6 months, mean values for UDVA (logMAR) were −0.043 ± 0.668 and −0.061 ± 0.099 in the PRK and thin-flap LASIK groups, respectively (n = 25, P = 0.466). UDVA of 20/20 or better was achieved in 96% of eyes undergoing PRK and 92% of eyes undergoing thin-flap LASIK, whereas 20/15 vision or better was achieved in 73% of eyes undergoing PRK and 72% of eyes undergoing thin-flap LASIK (P > 0.600). Significant differences were not found between treatment groups in contrast sensitivity (P ≥ 0.156) or CDVA (P = 0.800) at postoperative 6 months. Types of complications differed between groups, notably 35% of eyes in the thin-flap LASIK group experiencing complications, including microstriae and 2 flap tears. Conclusion: Under well-controlled surgical conditions, PRK and thin-flap LASIK refractive surgeries achieve similar results in visual acuity, contrast sensitivity, and induction of HOAs, with differences in experienced complications. PMID:21573091

A prospective, contralateral eye study comparing thin-flap LASIK (sub-Bowman keratomileusis) with photorefractive keratectomy.

PubMed

Slade, Stephen G; Durrie, Daniel S; Binder, Perry S

2009-06-01

To determine the differences in the visual results, pain response, biomechanical effect, quality of vision, and higher-order aberrations, among other parameters, in eyes undergoing either photorefractive keratectomy (PRK) or thin-flap LASIK/sub-Bowman keratomileusis (SBK; intended flap thickness of +/-100 microm and 8.5-mm diameter) at 1, 3, and 6 months after surgery. A contralateral eye pilot study. Fifty patients (100 eyes) were enrolled at 2 sites. The mean preoperative spherical refraction was -3.66 diopters (D) and the mean cylinder was -0.66 D for all eyes. Eyes in the PRK group underwent 8.5-mm ethanol-assisted PRK, whereas in eyes in the SBK group, an 8.5-mm, (intended) 100-microm flap was created with a 60-kHz IntraLase femtosecond laser (Advanced Medical Optics, Santa Ana, CA). All eyes underwent a customized laser ablation using an Alcon LADARVision 4000 CustomCornea excimer laser (Alcon Laboratories, Fort Worth, TX). Preoperative and postoperative tests included best spectacle-corrected visual acuity, uncorrected visual acuity (UCVA), corneal topography, wavefront aberrometry, retinal image quality, and contrast sensitivity. Patients completed subjective questionnaires at each visit. One- and 3-month UCVA results showed a statistically significant difference: SBK, 88% 20/20 or better vs. 48% 20/20 or better for PRK. At 6 months, UCVA was 94% 20/20 or better for PRK and 92% for SBK. At 1 and 3 months, the SBK group had lower higher-order aberrations (coma and spherical aberration; P

Treatment of nonneovascular idiopathic macular telangiectasia type 2 with intravitreal ranibizumab: results of a phase II clinical trial.

PubMed

Toy, Brian C; Koo, Euna; Cukras, Catherine; Meyerle, Catherine B; Chew, Emily Y; Wong, Wai T

2012-05-01

To evaluate the safety and preliminary efficacy of intravitreal ranibizumab for nonneovascular idiopathic macular telangiectasia Type 2. Single-center, open-label Phase II clinical trial enrolling five participants with bilateral nonneovascular idiopathic macular telangiectasia Type 2. Intravitreal ranibizumab (0.5 mg) was administered every 4 weeks in the study eye for 12 months with the contralateral eye observed. Outcome measures included changes in best-corrected visual acuity, area of late-phase leakage on fluorescein angiography, and retinal thickness on optical coherence tomography. The study treatment was well tolerated and associated with few adverse events. Change in best-corrected visual acuity at 12 months was not significantly different between treated study eyes (0.0 ± 7.5 letters) and control fellow eyes (+2.2 ± 1.9 letters). However, decreases in the area of late-phase fluorescein angiography leakage (-33 ± 20% for study eyes, +1 ± 8% for fellow eyes) and in optical coherence tomography central subfield retinal thickness (-11.7 ± 7.0% for study eyes and -2.9 ± 3.5% for fellow eyes) were greater in study eyes compared with fellow eyes. Despite significant anatomical responses to treatment, functional improvement in visual acuity was not detected. Intravitreal ranibizumab administered monthly over a time course of 12 months is unlikely to provide a general and significant benefit to patients with nonneovascular idiopathic macular telangiectasia Type 2.

Intraocular gene transfer of ciliary neurotrophic factor rescues photoreceptor degeneration in RCS rats.

PubMed

Huang, Shun-Ping; Lin, Po-Kang; Liu, Jorn-Hon; Khor, Chin-Ni; Lee, Yih-Jing

2004-01-01

Ciliary neurotrophic factor (CNTF) is known as an important factor in the regulation of retinal cell growth. We used both recombinant CNTF and an adenovirus carrying the CNTF gene to regulate retinal photoreceptor expression in a retinal degenerative animal, Royal College of Surgeons (RCS) rats. Cells in the outer nuclear layer of the retinae from recombinant-CNTF-treated, adenoviral-CNTF-treated, saline-operated, and contralateral untreated preparations were examined for those exhibiting CNTF photoreceptor protective effects. Cell apoptosis in the outer nuclear layer of the retinae was also detected. It was found that CNTF had a potent effect on delaying the photoreceptor degeneration process in RCS rats. Furthermore, adenovirus CNTF gene transfer was proven to be better at rescuing photoreceptors than that when using recombinant CNTF, since adenoviral CNTF prolonged the photoreceptor protection effect. The function of the photoreceptors was also examined by taking electroretinograms of different animals. Adenoviral-CNTF-treated eyes showed better retinal function than did the contralateral control eyes. This study indicates that adenoviral CNTF effectively rescues degenerating photoreceptors in RCS rats. Copyright 2004 National Science Council, ROC and S. Karger AG, Basel

Ocular pulse amplitude after panretinal photocoagulation in normotensive eyes with proliferative diabetic retinopathy.

PubMed

Bozic, Marija M; Karadzic, Jelena B; Kovacevic, Igor M; Marjanovic, Ivan S

2017-06-26

To assess the effect of panretinal laser photocoagulation on ocular pulse amplitude (OPA) in normotensive eyes with proliferative diabetic retinopathy. Prospectively, we performed unilateral argon laser panretinal photocoagulation (PRP) in 30 patients with diabetes mellitus type II and previously untreated bilateral proliferative diabetic retinopathy. Before and 7 and 30 days after the treatment, OPA was measured using dynamic contour tonometer. Compared with the untreated contralateral eyes, laser photocoagulation led to a reduction of OPA. Ocular pulse amplitude did not significantly differ in photocoagulated eyes 7 days after the treatment, but there was a significant difference in OPA 30 days after the treatment. The decrease in OPA values was 15% 7 days after PRP and 40% 30 days after PRP. Ocular pulse amplitude reduction after PRP indirectly informs us about choriocapillary closure, already reported in previous studies.

The subtlety of simple eyes: the tuning of visual fields to perceptual challenges in birds

PubMed Central

Martin, Graham R.

2014-01-01

Birds show interspecific variation both in the size of the fields of individual eyes and in the ways that these fields are brought together to produce the total visual field. Variation is found in the dimensions of all main parameters: binocular region, cyclopean field and blind areas. There is a phylogenetic signal with respect to maximum width of the binocular field in that passerine species have significantly broader field widths than non-passerines; broadest fields are found among crows (Corvidae). Among non-passerines, visual fields show considerable variation within families and even within some genera. It is argued that (i) the main drivers of differences in visual fields are associated with perceptual challenges that arise through different modes of foraging, and (ii) the primary function of binocularity in birds lies in the control of bill position rather than in the control of locomotion. The informational function of binocular vision does not lie in binocularity per se (two eyes receiving slightly different information simultaneously about the same objects from which higher-order depth information is extracted), but in the contralateral projection of the visual field of each eye. Contralateral projection ensures that each eye receives information from a symmetrically expanding optic flow-field from which direction of travel and time to contact targets can be extracted, particularly with respect to the control of bill position. PMID:24395967

Degree of corneal anaesthesia after topical application of 0.4% oxybuprocaine hydrochloride and 0.5% proparacaine hydrochloride ophthalmic solution in clinically normal cattle.

PubMed

Little, W B; Jean, G St; Sithole, F; Little, E; Jean, K Yvorchuk-St

2016-06-01

The use of corneal anaesthesia is necessary for a range of clinical purposes. Therefore, we assessed and compared the efficacy of corneal anaesthesia after application of 0.4% oxybuprocaine hydrochloride and 0.5% proparacaine hydrochloride ophthalmic solution in clinically normal cattle. The 24 clinically normal cows were allocated into two groups. Cows in group 1 (n = 12) received 0.2 mL of 0.4% oxybuprocaine hydrochloride with fluorescein ophthalmic solution in one eye and 0.2 mL of sterile saline (0.9% NaCl) with fluorescein in the contralateral eye (control). Group 2 (n = 12) received 0.2 mL of 0.4% oxybuprocaine hydrochloride with fluorescein ophthalmic solution in one eye and 0.2 mL of 0.5% proparacaine hydrochloride with fluorescein in the contralateral eye (control). In each group, corneal touch threshold was determined by Cochet-Bonnet aesthesiometer for both eyes immediately prior to topical administration of solutions, at 1 min and 5 min after administration of topical solutions and every 5 min thereafter for a total of 75 min. Significant corneal anaesthesia was noted immediately following topical application of both oxybuprocaine and proparacaine as compared with controls, with maximal corneal anaesthesia noted 1 min after administration. Both oxybuprocaine and proparacaine produced significant corneal anaesthesia for the duration of the 75-min study. Neither oxybuprocaine hydrochloride nor proparacaine hydrochloride treatment resulted in visible adverse effects. There are limited data available demonstrating the efficacy and duration of corneal anaesthetic agents in cattle. Both oxybuprocaine hydrochloride and proparacaine hydrochloride should be considered practical options for providing corneal anaesthesia in cattle in a clinical setting. © 2016 Australian Veterinary Association.

Corneal haze following PRK with mitomycin C as a retreatment versus prophylactic use in the contralateral eye.

PubMed

Netto, Marcelo V; Chalita, Maria Regina; Krueger, Ronald R

2007-01-01

To report photorefractive keratectomy (PRK) treated with mitomycin C (MMC) for previous corneal haze in one eye and PRK with MMC to prevent corneal haze formation in the fellow eye. A 40-year-old woman underwent PRK with MMC to treat previous corneal haze (secondary to previous PRK without MMC) for residual refractive error of +0.50 +0.25 x 165 in the left eye and PRK with MMC to prevent corneal haze in the right eye. Postoperative slit-lamp examination revealed no haze in the right eye, but continued mild haze in the left eye. Treatment with PRK and MMC for previous corneal haze is not as effective as primary PRK with MMC in preventing postoperative corneal haze formation.

Treatment of Non-neovascular Idiopathic Macular Telangiectasia Type 2 with Intravitreal Ranibizumab: Results of a Phase II Clinical Trial

PubMed Central

Toy, Brian C.; Koo, Euna; Cukras, Catherine; Meyerle, Catherine B.; Chew, Emily Y.; Wong, Wai T.

2015-01-01

Purpose To evaluate the safety and preliminary efficacy of intravitreal ranibizumab for non-neovascular idiopathic macular telangiectasia, type 2 (IMT2). Methods Single-center, open-label phase II clinical trial enrolling 5 participants with bilateral non-neovascular IMT2. Intravitreal ranibizumab (0.5mg) was administered every 4 weeks in the study eye for 12 months with the contralateral eye observed. Outcome measures included changes in: best corrected visual acuity (BCVA), area of late-phase leakage on fluorescein angiography (FA), and retinal thickness on optical coherence tomography (OCT). Results The study treatment was well-tolerated and associated with few adverse events. Change in BCVA at 12 months was not significantly different between treated study eyes (0.0±7.5 letters) and control fellow eyes (+2.2±1.9 letters). However, decreases in the area of late-phase FA leakage (−33±20% for study eyes, +1±8% for fellow eyes) and in OCT central subfield retinal thickness (−11.7±7.0% for study eyes and −2.9±3.5% for fellow eyes) were greater in study eyes compared to fellow eyes. Conclusions Despite significant anatomical responses to treatment, functional improvement in visual acuity was not detected. Intravitreal ranibizumab administered monthly over a time course of 12 months is unlikely to provide a general and significant benefit to patients with non-neovascular IMT2. PMID:22266930

Reduced Performance of Prey Targeting in Pit Vipers with Contralaterally Occluded Infrared and Visual Senses

PubMed Central

Chen, Qin; Deng, Huanhuan; Brauth, Steven E.; Ding, Li; Tang, Yezhong

2012-01-01

Both visual and infrared (IR) senses are utilized in prey targeting by pit vipers. Visual and IR inputs project to the contralateral optic tectum where they activate both multimodal and bimodal neurons. A series of ocular and pit organ occlusion experiments using the short-tailed pit viper (Gloydius brevicaudus) were conducted to investigate the role of visual and IR information during prey targeting. Compared with unoccluded controls, snakes with either both eyes or pit organs occluded performed more poorly in hunting prey although such subjects still captured prey on 75% of trials. Subjects with one eye and one pit occluded on the same side of the face performed as well as those with bilateral occlusion although these subjects showed a significant targeting angle bias toward the unoccluded side. Performance was significantly poorer when only a single eye or pit was available. Interestingly, when one eye and one pit organ were occluded on opposite sides of the face, performance was poorest, the snakes striking prey on no more than half the trials. These results indicate that, visual and infrared information are both effective in prey targeting in this species, although interference between the two modalities occurs if visual and IR information is restricted to opposite sides of the brain. PMID:22606229

Temporal Progression of Visual Injury from Blast Exposure

DTIC Science & Technology

2016-09-01

significantly different levels of protein among the experimental groups and between the eye ipsilateral and contralateral to the injury in each animal...vitreous biomarkers from the experimental studies. We added additional animals to this group due to some concerns with the accuracy of a small...Scientific Interface 2007 Solomon R Pollack Award for Excellence in Graduate Bioengineering Research 2001-2003 Stephenson Fellowship Award 2000-2004

[Sturge-Weber syndrome in port-wine stain patients: a retrospective study on the clinical features and screening strategy].

PubMed

Wu, Y; Yu, R J; Lin, X X; Guo, W Y

2017-10-11

Objective: To investigate the clinical characteristics of Sturge-Weber syndrome (SWS) in the patients with Port-wine stain (PWS). Methods: A total of 279 PWS patients, 164 males, 115 females with a median age of first visit 17.00 (4.75, 56.00) months. Most of the PWS patients were referred to the Ophthalmology Department for screening eye problems when the cutaneous angiomas involved the ophthalmic division of the trigeminal nerve distribution. The intraocular pressure (IOP), cup to disk ratio (C/D), corneal condition and other essential measurements were examined to screen glaucoma or choroidal hemangioma. The differences of age, gender and vascular ectasia in the ipsilateral eyes were compared among PWS and SWS patients with chi-square test. The differences about the first visit time, IOP, C/D and corneal diameters were evaluated with independent-sample T test or nonparametric test followed by Mann-Whitney U test. Results: A total number of 66 out of 279 PWS patients (23.7%) were confirmed as SWS with glaucoma. The IOP of the ipsilateral eye with vascular ectasia in PWS and SWS was 13.00 mmHg (1 mmHg=0.133 kPa) (IQR: 9.75, 17.00) and 23.00 mmHg (20.00, 32.00), respectively ( Z=- 8.212, P< 0.001); the IOP differences between the ipsilateral and contralateral eye in PWS and SWS was 1mmHg (0, 2) and 7 mmHg (3, 11) respectively; the C/D in the ipsilateral eye and the contralateral eye was 0.30 (0.30, 0.35) and 0.7 (0.6, 0.8) respectively in SWS cases with secondary glaucoma. Conclusions: There is a high proportion of SWS with glaucoma in ophthalmic division affected PWS patients. Fundus examinations were necessary for this type of patients. (Chin J Ophthalmol, 2017, 53:753-757) .

Functions of corazonin and histamine in light entrainment of the circadian pacemaker in the Madeira cockroach, Rhyparobia maderae.

PubMed

Arendt, Andreas; Baz, El-Sayed; Stengl, Monika

2017-04-01

The circadian pacemaker of the Madeira cockroach, Rhyparobia (Leucophaea) maderae, is located in the accessory medulla (AME). Ipsi- and contralateral histaminergic compound eyes are required for photic entrainment. Light pulses delay locomotor activity rhythm during the early night and advance it during the late night. Thus, different neuronal pathways might relay either light-dependent delays or advances to the clock. Injections of neuroactive substances combined with running-wheel assays suggested that GABA, pigment-dispersing factor, myoinhibitory peptides (MIPs), and orcokinins (ORCs) were part of both entrainment pathways, whereas allatotropin (AT) only delayed locomotor rhythms at the early night. To characterize photic entrainment further, histamine and corazonin were injected. Histamine injections resulted in light-like phase delays and advances, indicating that the neurotransmitter of the compound eyes participates in both entrainment pathways. Because injections of corazonin only advanced during the late subjective night, it was hypothesized that corazonin is only part of the advance pathway. Multiple-label immunocytochemistry in combination with neurobiotin backfills demonstrated that a single cell expressed corazonin in the optic lobes that belonged to the group of medial AME interneurons. It colocalized GABA and MIP but not AT or ORC immunoreactivity. Corazonin-immunoreactive (-ir) terminals overlapped with projections of putatively light-sensitive interneurons from the ipsi- and contralateral compound eye. Thus, we hypothesize that the corazonin-ir medial neuron integrates ipsi- and contralateral light information as part of the phase-advancing light entrainment pathway to the circadian clock. J. Comp. Neurol. 525:1250-1272, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

The effects of left and right monocular viewing on hemispheric activation.

PubMed

Wang, Chao; Burtis, D Brandon; Ding, Mingzhou; Mo, Jue; Williamson, John B; Heilman, Kenneth M

2018-03-01

Prior research has revealed that whereas activation of the left hemisphere primarily increases the activity of the parasympathetic division of the autonomic nervous system, right-hemisphere activation increases the activity of the sympathetic division. In addition, each hemisphere primarily receives retinocollicular projections from the contralateral eye. A prior study reported that pupillary dilation was greater with left- than with right-eye monocular viewing. The goal of this study was to test the alternative hypotheses that this asymmetric pupil dilation with left-eye viewing was induced by activation of the right-hemispheric-mediated sympathetic activity, versus a reduction of left-hemisphere-mediated parasympathetic activity. Thus, this study was designed to learn whether there are changes in hemispheric activation, as measured by alteration of spontaneous alpha activity, during right versus left monocular viewing. High-density electroencephalography (EEG) was recorded from healthy participants viewing a crosshair with their right, left, or both eyes. There was a significantly less alpha power over the right hemisphere's parietal-occipital area with left and binocular viewing than with right-eye monocular viewing. The greater relative reduction of right-hemisphere alpha activity during left than during right monocular viewing provides further evidence that left-eye viewing induces greater increase in right-hemisphere activation than does right-eye viewing.

[Comparison of Discriminant Analysis and Decision Trees for the Detection of Subclinical Keratoconus].

PubMed

Kleinhans, Sonja; Herrmann, Eva; Kohnen, Thomas; Bühren, Jens

2017-08-15

Background Iatrogenic keratectasia is one of the most dreaded complications of refractive surgery. In most cases, keratectasia develops after refractive surgery of eyes suffering from subclinical stages of keratoconus with few or no signs. Unfortunately, there has been no reliable procedure for the early detection of keratoconus. In this study, we used binary decision trees (recursive partitioning) to assess their suitability for discrimination between normal eyes and eyes with subclinical keratoconus. Patients and Methods The method of decision tree analysis was compared with discriminant analysis which has shown good results in previous studies. Input data were 32 eyes of 32 patients with newly diagnosed keratoconus in the contralateral eye and preoperative data of 10 eyes of 5 patients with keratectasia after laser in-situ keratomileusis (LASIK). The control group was made up of 245 normal eyes after LASIK and 12-month follow-up without any signs of iatrogenic keratectasia. Results Decision trees gave better accuracy and specificity than did discriminant analysis. The sensitivity of decision trees was lower than the sensitivity of discriminant analysis. Conclusion On the basis of the patient population of this study, decision trees did not prove to be superior to linear discriminant analysis for the detection of subclinical keratoconus. Georg Thieme Verlag KG Stuttgart · New York.

Short-duration stimulation of the supplementary eye fields perturbs anti-saccade performance while potentiating contralateral head orienting.

PubMed

Chapman, Brendan B; Corneil, Brian D

2014-01-01

Many forms of brain stimulation utilize the notion of state dependency, whereby greater influences are observed when a given area is more engaged at the time of stimulation. Here, by delivering intracortical microstimulation (ICMS) to the supplementary eye fields (SEF) of monkeys performing interleaved pro- and anti-saccades, we show a surprising diversity of state-dependent effects of ICMS-SEF. Short-duration ICMS-SEF passed around cue presentation selectively disrupted anti-saccades by increasing reaction times and error rates bilaterally, and also recruited neck muscles, favoring contralateral head turning to a greater degree on anti-saccade trials. These results are consistent with the functional relevance of the SEF for anti-saccades. The multiplicity of stimulation-evoked effects, with ICMS-SEF simultaneously disrupting anti-saccade performance and facilitating contralateral head orienting, probably reflects both the diversity of cortical and subcortical targets of SEF projections, and the response of this oculomotor network to stimulation. We speculate that the bilateral disruption of anti-saccades arises via feedback loops that may include the thalamus, whereas neck muscle recruitment arises via feedforward polysynaptic pathways to the motor periphery. Consideration of both sets of results reveals a more complete picture of the highly complex and multiphasic response to ICMS-SEF that can play out differently in different effector systems.

Extraocular muscle proprioception and eye position.

PubMed

Pettorossi, V E; Ferraresi, A; Draicchio, F; Errico, P; Santarelli, R; Manni, E

1995-03-01

In the lamb, acute unilateral section of the ophthalmic branch induced in the ipsilateral eye occasional oscillations of the resting position and misalignment of the horizontal vestibulo-ocular reflex (HVOR) with respect to the stimulus. Additional electrolytic lesion of the cells innervating the proprioceptors of the medial rectus muscle, or of the lateral rectus muscle in the contralateral semilunar ganglion, provoked a 4 degrees-7 degrees consensual eye deviation towards and away from the lesioned side, respectively. The optokinetic beating field was similarly deviated. Under these experimental conditions, HVOR showed enhanced gain and marked misalignment in both eyes. Therefore, the selective suppression of muscular proprioceptive input deviated both eyes towards the direction opposite to the muscle whose gangliar proprioceptive representation has been destroyed.

Retinal Laser Burn Disrupts Immune Privilege in the Eye

PubMed Central

Qiao, Hong; Lucas, Kenyatta; Stein-Streilein, Joan

2009-01-01

Immune privilege allows for the immune protection of the eye in the absence of inflammation. Very few events are capable of overcoming the immune-privileged mechanisms in the eye. In this study, we report that retinal laser burn (RLB) abrogates immune privilege in both the burned and nonburned eye. As early as 6 hours after RLB, and as late as 56 days after RLB, antigen inoculation into the anterior chamber of the burned eye failed to induce peripheral tolerance. After RLB, aqueous humor samples harvested from nontreated eyes but not from either the burned or the contralateral eye, down-regulated the expression of CD40 and up-regulated interleukin-10 mRNA in peritoneal exudate cells, and converted peritoneal exudate cells into tolerogenic antigen-presenting cells (APCs). Unlike F4/80+ APCs from nontreated mice, F4/80+ APCs from RLB mice were unable to transfer tolerance after anterior chamber inoculation of antigen into naïve mice. The increased use of lasers in both the industrial and medical fields raises the risk of RLB-associated loss of immune regulation and an increased risk of immune inflammation in the eye. PMID:19147817

Accommodation and the Visual Regulation of Refractive State in Marmosets

PubMed Central

Troilo, David; Totonelly, Kristen; Harb, Elise

2009-01-01

Purpose To determine the effects of imposed anisometropic retinal defocus on accommodation, ocular growth, and refractive state changes in marmosets. Methods Marmosets were raised with extended-wear soft contact lenses for an average duration of 10 wks beginning at an average age of 76 d. Experimental animals wore either a positive or negative contact lens over one eye and a plano lens or no lens over the other. Another group wore binocular lenses of equal magnitude but opposite sign. Untreated marmosets served as controls and three wore plano lenses monocularly. Cycloplegic refractive state, corneal curvature, and vitreous chamber depth were measured before, during, and after the period of lens wear. To investigate the accommodative response, the effective refractive state was measured through each anisometropic condition at varying accommodative stimuli positions using an infrared refractometer. Results Eye growth and refractive state are significantly correlated with the sign and power of the contact lens worn. The eyes of marmosets reared with monocular negative power lenses had longer vitreous chambers and were myopic relative to contralateral control eyes (p<0.01). Monocular positive power lenses produced a significant reduction in vitreous chamber depth and hyperopia relative to the contralateral control eyes (p<0.05). In marmosets reared binocularly with lenses of opposite sign, we found larger interocular differences in vitreous chamber depths and refractive state (p<0.001). Accommodation influences the defocus experienced through the lenses, however, the mean effective refractive state was still hyperopia in the negative-lens-treated eyes and myopia in the positive-lens-treated eyes. Conclusions Imposed anisometropia effectively alters marmoset eye growth and refractive state to compensate for the imposed defocus. The response to imposed hyperopia is larger and faster than the response to imposed myopia. The pattern of accommodation under imposed anisometropia produces effective refractive states that are consistent with the changes in eye growth and refractive state observed. PMID:19104464

Convergent synaptic inputs from the caudal fastigial nucleus and the superior colliculus onto pontine and pontomedullary reticulospinal neurons.

PubMed

Takahashi, Mayu; Sugiuchi, Yuriko; Shinoda, Yoshikazu

2014-02-01

The caudal fastigial nucleus (FN) is known to be related to the control of eye movements and projects mainly to the contralateral reticular nuclei where excitatory and inhibitory burst neurons for saccades exist [the caudal portion of the nucleus reticularis pontis caudalis (NRPc), and the rostral portion of the nucleus reticularis gigantocellularis (NRG) respectively]. However, the exact reticular neurons targeted by caudal fastigioreticular cells remain unknown. We tried to determine the target reticular neurons of the caudal FN and superior colliculus (SC) by recording intracellular potentials from neurons in the NRPc and NRG of anesthetized cats. Neurons in the rostral NRG received bilateral, monosynaptic excitation from the caudal FNs, with contralateral predominance. They also received strong monosynaptic excitation from the rostral and caudal contralateral SC, and disynaptic excitation from the rostral ipsilateral SC. These reticular neurons with caudal fastigial monosynaptic excitation were not activated antidromically from the contralateral abducens nucleus, but most of them were reticulospinal neurons (RSNs) that were activated antidromically from the cervical cord. RSNs in the caudal NRPc received very weak monosynaptic excitation from only the contralateral caudal FN, and received either monosynaptic excitation only from the contralateral caudal SC, or monosynaptic and disynaptic excitation from the contralateral caudal and ipsilateral rostral SC, respectively. These results suggest that the caudal FN helps to control also head movements via RSNs targeted by the SC, and these RSNs with SC topographic input play different functional roles in head movements.

A novel method for the induction of experimental glaucoma using magnetic microspheres.

PubMed

Samsel, Paulina A; Kisiswa, Lilian; Erichsen, Jonathan T; Cross, Stephen D; Morgan, James E

2011-03-25

The development of a method for the sustained elevation of intraocular pressure in experimental glaucoma based on the anterior chamber injection of paramagnetic microbeads. Unilateral glaucoma was induced in adult male Norwegian Brown rats by the injection of paramagnetic polystyrene microspheres. A handheld 0.45 Tesla magnet was used to draw the beads into the iridocorneal angle to impede aqueous drainage via the trabecular meshwork. Elevated intraocular pressures (IOPs) were induced in 61 rats, resulting in a mean elevation of 5.8 mm Hg ± 1.0 (SEM) relative to the contralateral control eye. The mean duration of sustained IOP elevation (defined as >5 mm Hg relative to the control eye for at least 7 consecutive days) after a single injection was 12.8 days ± 0.9 (SEM, maximum duration 27 days). In all eyes, the visual axis remained clear from the time of injection, with minimal inflammation after injection. Retinal ganglion cell loss was determined in 21 animals (mean integral IOP, 194.5 mm Hg days ± 87.5 [SEM]) as 36.4% ± 2.4 (SEM) compared with the contralateral, untreated eye. The use of paramagnetic microbeads for the occlusion of the iridocorneal angle produces a sustained elevation of IOP with fewer injections and avoids the risk of visual axis occlusion. It represents a simple and effective method for the induction of experimental glaucoma.

Interocular Difference of Peripheral Refraction in Anisomyopic Eyes of Schoolchildren

PubMed Central

Chen, Junhong; He, Ji C.; Chen, Yunyun; Xu, Jingjing; Wu, Haoran; Wang, Feifu; Lu, Fan; Jiang, Jun

2016-01-01

Purpose Refraction in the peripheral visual field is believed to play an important role in the development of myopia. The purpose of this study was to investigate the differences in peripheral refraction among anisomyopia, isomyopia, and isoemmetropia for schoolchildren. Methods Thirty-eight anisomyopic children were recruited and divided into two groups: (1) both eyes were myopic (anisomyopic group, AM group) and (2) one eye was myopic and the contralateral eye was emmetropic (emmetropic anisomyopic group, EAM group). As controls, 45 isomyopic and isoemmetropic children were also recruited with age and central spherical equivalent (SE) matched to those of the AM and EAM groups. The controls were divided into three groups: (1) intermediate myopia group (SE matched to the more myopic eye of AM group), (2) low myopia group (SE matched to the less myopic eye of AM group and the more myopic eye of EAM group), and (3) emmetropia group (SE matched to the less myopic eye of EAM group). Peripheral refraction at 7 points across the central ±30° on the horizontal visual field with a 10° interval was measured with an autorefractor. Axial length (AL), corneal curvature (CC), and anterior chamber depth (ACD) were also determined by using the Zeiss IOL-Master. Results The relative peripheral spherical equivalent [RPR(M)] and relative peripheral spherical value [RPR(S)] of the more myopic eye was shifted more hyperopically than the contralateral eye in both the AM and the EAM groups (both p<0.0001). The RPR(M, S) of the less myopic eyes in the AM and EAM groups showed a relatively flat trend across the visual field and were not significantly different from the emmetropia group. The RPR(M, S) of less myopic eyes in the AM group were shifted less hyperopically than in the isomyopic low myopia group and the more myopic eye of the EAM group [RPR(M), p = 0.007; RPR(S), p = 0.001], although the central SEs of the three groups were not significantly different from each other. However, RPR(M, S) of the more myopic eyes were not different from the corresponding isomyopic groups. There was also no significant difference in the relative peripheral astigmatism [RPR(J0, J45)] between the more and the less myopic eyes in either the AM or the EAM group. Conclusion Refraction of anisomyopia differs between the two eyes not only at the central visual field but also at the off-axis periphery. The relative peripheral refraction of the more myopic eye of anisomyopia was shifted hyperopically, as occurs in isomyopia with similar central subjective SE values. Less myopic eyes were much less hyperopically shifted in relative peripheral refraction than the corresponding isomyopic eyes, but are comparable to emmetropic eyes. This emmetropia-like relative peripheral refraction in less myopic eyes might be a factor responsible for slowing down the progression of myopia. PMID:26881745

Interocular Difference of Peripheral Refraction in Anisomyopic Eyes of Schoolchildren.

PubMed

Chen, Junhong; He, Ji C; Chen, Yunyun; Xu, Jingjing; Wu, Haoran; Wang, Feifu; Lu, Fan; Jiang, Jun

2016-01-01

Refraction in the peripheral visual field is believed to play an important role in the development of myopia. The purpose of this study was to investigate the differences in peripheral refraction among anisomyopia, isomyopia, and isoemmetropia for schoolchildren. Thirty-eight anisomyopic children were recruited and divided into two groups: (1) both eyes were myopic (anisomyopic group, AM group) and (2) one eye was myopic and the contralateral eye was emmetropic (emmetropic anisomyopic group, EAM group). As controls, 45 isomyopic and isoemmetropic children were also recruited with age and central spherical equivalent (SE) matched to those of the AM and EAM groups. The controls were divided into three groups: (1) intermediate myopia group (SE matched to the more myopic eye of AM group), (2) low myopia group (SE matched to the less myopic eye of AM group and the more myopic eye of EAM group), and (3) emmetropia group (SE matched to the less myopic eye of EAM group). Peripheral refraction at 7 points across the central ±30° on the horizontal visual field with a 10° interval was measured with an autorefractor. Axial length (AL), corneal curvature (CC), and anterior chamber depth (ACD) were also determined by using the Zeiss IOL-Master. The relative peripheral spherical equivalent [RPR(M)] and relative peripheral spherical value [RPR(S)] of the more myopic eye was shifted more hyperopically than the contralateral eye in both the AM and the EAM groups (both p<0.0001). The RPR(M, S) of the less myopic eyes in the AM and EAM groups showed a relatively flat trend across the visual field and were not significantly different from the emmetropia group. The RPR(M, S) of less myopic eyes in the AM group were shifted less hyperopically than in the isomyopic low myopia group and the more myopic eye of the EAM group [RPR(M), p = 0.007; RPR(S), p = 0.001], although the central SEs of the three groups were not significantly different from each other. However, RPR(M, S) of the more myopic eyes were not different from the corresponding isomyopic groups. There was also no significant difference in the relative peripheral astigmatism [RPR(J0, J45)] between the more and the less myopic eyes in either the AM or the EAM group. Refraction of anisomyopia differs between the two eyes not only at the central visual field but also at the off-axis periphery. The relative peripheral refraction of the more myopic eye of anisomyopia was shifted hyperopically, as occurs in isomyopia with similar central subjective SE values. Less myopic eyes were much less hyperopically shifted in relative peripheral refraction than the corresponding isomyopic eyes, but are comparable to emmetropic eyes. This emmetropia-like relative peripheral refraction in less myopic eyes might be a factor responsible for slowing down the progression of myopia.

Protective effect of 4-coumaric acid from UVB ray damage in the rabbit eye.

PubMed

Lodovici, Maura; Caldini, Silvia; Morbidelli, Lucia; Akpan, Victor; Ziche, Marina; Dolara, Piero

2009-01-08

UV-induced oxidation damage seems to play a major role in a number of specific pathological conditions of intraocular tissues, such as cataract formation and retinal degeneration. Therefore, antioxidant and/or scavenger compounds might protect the eyes from UV-induced cellular damage. We previously reported that 4-coumaric acid (4-CA) is able to protect rabbit corneal-derived cells (SIRC) from UVB-induced oxidation damage. In this study we evaluated the protective effect of 4-CA against UVB-induced cell damage in rabbit cornea in vivo. Twelve male New Zealand albino rabbits were used; four rabbits were used as a control and received vehicle in one eye and 4-CA acid in the contralateral eye; eight rabbits were exposed to UVB rays (79.2mJ/cm(2)) and three days before to UV exposure each animal received 1 drop/day of vehicle in one eye and 1 drop/day of vehicle containing 4-CA (164ng) in the contralateral eye. Corneal and sclera tissues were removed and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) levels were measured. Superoxide dismutase (SOD) and xanthine oxidase (XO) activities were determined in aqueous humour. UVB-induced vessel hyper-reactivity was strongly reduced at 4 and 24h after UVB exposure after local treatment with 4-CA, 8-oxodGuo levels, a marker of oxidative DNA damage, were significantly increased (P<0.05) in sclera and cornea by UVB irradiation, but when 4-CA was administered to the conjunctiva in a buffered solution once a day for 3d before and 6d after UVB exposure, levels of 8-oxodGuo were similar to controls and significantly reduced (P<0.05) compared to UVB-treated corneas. XO activity in the aqueous humour was significantly increased. The administration of 4-CA for 3d before and 6d after UVB irradiation induced a small but significant (P<0.05) reduction of XO compared with control eyes. Our results indicate that the administration of 4-CA protects eye tissues, thus reducing the harmful effect of UVB radiation at low concentration, probably through its free radical scavenging and antioxidant properties. Therefore, 4-CA may be useful in protecting the eye from free radical damage following UVB exposure from sunlight, UV lamps and welding torches.

Intraocular straylight and contrast sensitivity after contralateral wavefront-guided LASIK and wavefront-guided PRK for myopia.

PubMed

Barreto, Jackson; Barboni, Mirella T S; Feitosa-Santana, Claudia; Sato, João R; Bechara, Samir J; Ventura, Dora F; Alves, Milton Ruiz

2010-08-01

To compare intraocular straylight measurements and contrast sensitivity after wavefront-guided LASIK (WFG LASIK) in one eye and wavefront-guided photorefractive keratectomy (WFG PRK) in the fellow eye for myopia and myopic astigmatism correction. A prospective, randomized study of 22 eyes of 11 patients who underwent simultaneous WFG LASIK and WFG PRK (contralateral eye). Both groups were treated with the NIDEK Advanced Vision Excimer Laser System, and a microkeratome was used for flap creation in the WFG LASIK group. High and low contrast visual acuity, wavefront analysis, contrast sensitivity, and retinal straylight measurements were performed preoperatively and at 3, 6, and 12 months postoperatively. A third-generation straylight meter, C-Quant (Oculus Optikgeräte GmbH), was used for measuring intraocular straylight. Twelve months postoperatively, mean uncorrected distance visual acuity was -0.06 +/- 0.07 logMAR in the WFG LASIK group and -0.10 +/- 0.10 logMAR in the WFG PRK group. Mean preoperative intraocular straylight was 0.94 +/- 0.12 logs for the WFG LASIK group and 0.96 +/- 0.11 logs for the WFG PRK group. After 12 months, the mean straylight value was 1.01 +/- 0.1 log s for the WFG LASIK group and 0.97 +/- 0.12 log s for the WFG PRK group. No difference was found between techniques after 12 months (P = .306). No significant difference in photopic and mesopic contrast sensitivity between groups was noted. Intraocular straylight showed no statistically significant increase 1 year after WFG LASIK and WFG PRK. Higher order aberrations increased significantly after surgery for both groups. Nevertheless, WFG LASIK and WFG PRK yielded excellent visual acuity and contrast sensitivity performance without significant differences between techniques.

Corneal endothelial cell density after femtosecond thin-flap LASIK and PRK for myopia: a contralateral eye study.

PubMed

Smith, Ryan T; Waring, George O; Durrie, Daniel S; Stahl, Jason E; Thomas, Priscilla

2009-12-01

To compare the effect of femtosecond thinflap LASIK and photorefractive keratectomy (PRK) on postoperative endothelial cell density. In a prospective, randomized, contralateral, single-center clinical trial, 25 patients (mean age: 30+/-5 years [range: 21 to 38 years]) underwent PRK in one eye and thin-flap LASIK in the fellow eye for the correction of myopia using a wavefront-guided platform. The central corneal endothelial cell density was measured using the NIDEK Confoscan 4 preoperatively, and at 1 and 3 months postoperatively. Changes in endothelial cell density were analyzed over time between the two refractive techniques. In PRK, the average preoperative endothelial cell density was 3011+/-329 cells/mm(2), which decreased to 2951+/-327 cells/mm(2) at 1 month (P=.5736) and 2982+/-365 cells/mm(2) at 3 months (P=.6513). In thinflap LASIK, the average preoperative endothelial cell density was 2995+/-325 cells/mm(2), which decreased to 2977+/-358 cells/mm(2) at 1 month (P=.5756) and 2931+/-369 cells/mm(2) at 3 months (P=.4106). No statistically significant difference was found between the two groups at 1 (P=.7404) or 3 (P=.3208) months postoperatively. No statistically significant change was noted in endothelial cell density following either PRK or thin-flap LASIK for the treatment of myopia. Furthermore, no statistically significant difference was found between the two groups out to 3 months postoperatively, indicating that thin-flap LASIK is as safe as PRK with regards to endothelial health.

Art in the eye of the beholder: the perception of art during monocular viewing.

PubMed

Finney, Glen Raymond; Heilman, Kenneth M

2008-03-01

To explore whether monocular viewing affects judgment of art. Each superior colliculus receives optic nerve fibers primarily from the contralateral eye, and visual input to each colliculus activates the ipsilateral hemisphere. In previous studies, monocular viewing influenced performance on visual-spatial and verbal memory tasks. Eight college-educated subjects, 6 men and 2 women, monocularly viewed 10 paintings with the right eye and another 10 with the left. Subjects had not previously seen the paintings. Each time, 5 paintings were abstract expressionist and 5 were impressionist. The orders of eye viewing and painting viewed were pseudorandomized and counterbalanced. Subjects rated on a 1 to 10 scale 4 qualities of the paintings: representation, aesthetics (beauty), novelty, and closure (completeness). Paintings in the abstract expressionist style had a significant difference in the rating of novelty; the paintings were rated more novel when viewed with the left eye than with the right eye. There was a trend for rating paintings as having more closure when viewing with the right eye than with the left. Impressionist paintings show no differences. Monocular viewing influences artistic judgments; novelty being rated higher when viewed with the left eye. Asymmetric projections from each eye and hemispheric specialization are posited to explain these differences.

In vivo confocal microscopic investigation of the cornea after autologous implantation of lenticules obtained through small incision lenticule extraction for treatment of hyperopia.

PubMed

Li, Meiyan; Li, Meng; Sun, Ling; Han, Tian; Ding, Lan; Xiang, Jun; Zhou, Xingtao

2018-01-01

To investigate re-innervation in the implanted lenticule, as well as changes to the cornea, after correcting hyperopia with an autologous implantation of a lenticule obtained through small incision lenticule extraction (SMILE). This study retrospectively analysed re-innervation in the implanted lenticule, as well as microscopic morphological changes in the corneal architecture of the recipient cornea in five patients (with myopia in one eye and hyperopia in the contralateral eye) who received SMILE in the myopic eye and femtosecond laser in situ keratomileusis (FS-LASIK) combined with lenticule implantation in the contralateral hyperopic eye. Re-innervation in the implanted lenticule, as well as microscopic morphological changes in corneal architecture, were evaluated by in vivo confocal microscopy. One patient was examined at postoperative week six, two were examined at postoperative month two, one was examined at postoperative month nine, and one was examined at postoperative month 12. Partial subbasal nerve fibre regeneration was detected in two patients (Case 4 who was examined at postoperative month nine and Case 5 who was examined at postoperative month 12). Regenerated and branched nerve fibres were detected in the implanted lenticule in Case 5 who was examined at postoperative month 12. Both the anterior and posterior interfaces showed an absence or decrease of keratocytes and the presence of small particles of various brightnesses. Keratocytes in the implanted lenticule presented abnormal morphology in size and shape after surgery in all treated eyes, but showed partial morphological recovery in two patients (Case 4 who was examined at postoperative month nine and Case 5 who was examined at postoperative month 12). These preliminary findings suggest that nerve fibres will regenerate into the implanted lenticule after autologous lenticule implantation. Keratocytes in lenticules demonstrated a gradual return to a normal morphology. © 2017 Optometry Australia.

Dichoptic training enables the adult amblyopic brain to learn.

PubMed

Li, Jinrong; Thompson, Benjamin; Deng, Daming; Chan, Lily Y L; Yu, Minbin; Hess, Robert F

2013-04-22

Adults with amblyopia, a common visual cortex disorder caused primarily by binocular disruption during an early critical period, do not respond to conventional therapy involving occlusion of one eye. But it is now clear that the adult human visual cortex has a significant degree of plasticity, suggesting that something must be actively preventing the adult brain from learning to see through the amblyopic eye. One possibility is an inhibitory signal from the contralateral eye that suppresses cortical inputs from the amblyopic eye. Such a gating mechanism could explain the apparent lack of plasticity within the adult amblyopic visual cortex. Here we provide direct evidence that alleviating suppression of the amblyopic eye through dichoptic stimulus presentation induces greater levels of plasticity than forced use of the amblyopic eye alone. This indicates that suppression is a key gating mechanism that prevents the amblyopic brain from learning to see. Copyright © 2013 Elsevier Ltd. All rights reserved.

The Risk of Intraocular Pressure Elevation in Pediatric Non-infectious Uveitis

PubMed Central

Kothari, Srishti; Foster, C. Stephen; Pistilli, Maxwell; Liesegang, Teresa L.; Daniel, Ebenezer; Sen, H. Nida; Suhler, Eric B.; Thorne, Jennifer E.; Jabs, Douglas A.; Levy-Clarke, Grace A.; Nussenblatt, Robert B.; Rosenbaum, James T.; Lawrence, Scott D.; Kempen, John H.

2015-01-01

Purpose To characterize the risk and risk factors for intraocular pressure (IOP) elevation in pediatric non-infectious uveitis. Design Multi-center retrospective cohort study. Participants Nine hundred sixteen children (1593 eyes) <18 years old at presentation with non-infectious uveitis followed between January 1978 through December 2007 at five academic uveitis centers in United States. Methods Medical records review by trained, certified experts. Main outcome measures Prevalence and incidence of IOP≥21 and ≥30mmHg and incidence of a rise in IOP by ≥10mmHg. To avoid under ascertainment, outcomes were counted as present when IOP-lowering therapies were in use. Results Initially 251 (15.8%) and 46 eyes (2.9%) had IOP≥21 and ≥30mmHg, respectively. Factors associated with presenting IOP elevation included age 6–12 years (versus other pediatric ages), prior cataract surgery (adjusted odds ratio≥21mmHg [aOR21]=2.42, P=0.01), pars plana vitrectomy (adjusted odds ratio≥30mmHg[aOR30]=11.1, P=0.03), duration of uveitis ≥6 months (aORs30 up to 11.8, P<0.001), contralateral IOP elevation (aOR21=16.9, aOR30=8.29; each P<0.001), visual acuity worse than 20/40 (aORs21 up to 1.73, P=0.02; aORs30 up to 2.81 P=0.03), and topical corticosteroid use (aORs up to 8.92, P<0.001 in a dose-response relationship). The median follow-up was 1.25 years (interquartile range 0.4–3.66). The estimated risk of any observed IOP elevation to ≥21 mmHg, ≥30 mmHg and of a rise in IOP by ≥10mmHg was 33.4%, 14.8% and 24.4% respectively within 2 years. Factors associated with IOP elevation included pars plana vitrectomy (adjusted hazard ratio≥21mmHg[aHR21]=3.36, P<0.001), contralateral IOP elevation (aHRs up to 9.54, P<0.001), the use of topical (aHRs up to 8.77 that followed a dose-response relationship, P<0.001), periocular (aHRs up to 7.96, P<0.001) and intraocular (aHRs up to 19.7, P<0.001) corticosteroids. Conclusions IOP elevation affects a large minority of children with non-infectious uveitis. Statistically significant risk factors include IOP elevation or use of IOP-lowering treatment in the contralateral eye and local corticosteroid use – that demonstrated a dose-and route of administration-dependent relationship. In contrast, use of immunosuppressive drug therapy did not increase such risk. Pediatric eyes with non-infectious uveitis should be followed closely for IOP elevation when strong risk factors such as the use of local corticosteroids and contralateral IOP elevation are present. PMID:26233626

Retention of retinal axon collateral is responsible for induced ipsilateral retinotectal projections in adult goldfish.

PubMed

Sharma, S C; Tsai, C

1991-01-01

In normal goldfish, optic axons innervate only the contralateral optic tectum. When one eye was enucleated and the optic nerve of the other eye crushed, the regenerating optic axons innervated both optic tecta. We studied the presence of bilaterally projecting retinal ganglion cells by double retrograde cell labeling methods using Nuclear Yellow and True Blue dyes. About 10% of the retinal ganglion cells were double labeled and these cells were found throughout the retina. In addition, HRP application to the ipsilateral tectum revealed retrogradely-labeled retinal ganglion cells of all morphological types. These results suggest that induced ipsilateral projections are formed by regenerating axon collaterals and that all cell types are involved in the generation of normal mirror image typography.

Tear production and intraocular pressure in canine eyes with corneal ulceration

PubMed Central

Williams, David L.; Burg, Philippa

2017-01-01

This study aimed to evaluate changes in lacrimation and intraocular pressure (IOP) in dogs with unilateral corneal ulceration using the Schirmer tear test (STT) and rebound (TonoVet®) tonometry. IOP and STT values were recorded in both ulcerated and non-ulcerated (control) eyes of 100 dogs diagnosed with unilateral corneal ulceration. Dogs presented with other ocular conditions as their primary complaint were excluded from this study. The mean ± standard deviation for STT values in the ulcerated and control eyes were 20.2±4.6 mm/min and 16.7±3.5 mm/min respectively. The mean ± standard deviation for IOP in the ulcerated and control eyes were 11.9±3.1 mmHg and 16.7±2.6 mmHg respectively. STT values were significantly higher (p<0.000001) in the ulcerated eye compared to the control eye while IOP was significantly lower (p<0.0001). There is an increase in lacrimation and a decrease in IOP in canine eyes with corneal ulceration. The higher tear production in ulcerated eyes shows the importance of measuring STT in both eyes in cases of corneal ulceration, since this increased lacrimation may mask an underlying keratoconjunctivitis sicca only evident in the contralateral eye. The lower IOP in ulcerated eyes is likely to relate to mild uveitic change in the ulcerated eye with a concomitant increase in uveoscleral aqueous drainage. While these changes in tear production and IOP in ulcerated eyes are widely recognised in both human and veterinary ophthalmology, it appears that this is the first controlled documented report of these changes in a large number of individuals. PMID:28616393

Effect of the Regenerative Agent Poly(Carboxymethylglucose Sulfate) on Corneal Wound Healing After Corneal Cross-Linking for Keratoconus.

PubMed

Kymionis, George D; Liakopoulos, Dimitrios A; Grentzelos, Michael A; Tsoulnaras, Konstantinos I; Detorakis, Efstathios T; Cochener, Béatrice; Tsilimbaris, Miltiadis K

2015-08-01

To evaluate the effect of a regenerative agent (RGTA) [Cacicol20-poly(carboxymethyl glucose sulfate); OTR3, Paris, France] on corneal reepithelialization and pain after corneal cross-linking (CXL) for keratoconus. In this prospective comparative (contralateral) clinical study, patients with bilateral progressive keratoconus underwent CXL treatment. The corneal epithelium during CXL was removed using transepithelial phototherapeutic keratectomy (Cretan protocol). One eye of each patient was randomly instilled with an RGTA (Cacicol20) once a day (study group), whereas the fellow eye was instilled with artificial tears (control group). Patients were examined daily until complete reepithelialization. Postoperative examinations included slit-lamp biomicroscopy to assess the epithelial defect size and subjective evaluation of pain. The study enrolled 18 patients (36 eyes). The mean epithelial defect size for study and control groups was 19.6 ± 4.2 mm versus 21.5 ± 2.8 mm, respectively, at day 1 (P = 0.019) and 6.4 ± 3.4 mm versus 7.9 ± 4.3 mm, respectively, at day 2 (P = 0.014). At day 3 postoperatively, 61.1% of study eyes were fully reepithelialized, compared with 11.1% of control eyes (P = 0.002). RGTA (Cacicol20) instillation seems to result in faster corneal reepithelialization after CXL in this study. However, there was no significant effect in subjective pain/discomfort.

Central Connections of the Lacrimal Functional Unit.

PubMed

Willshire, Catherine; Buckley, Roger J; Bron, Anthony J

2017-08-01

To study the contribution of each eye to the reflex tear response, after unilateral and bilateral topical anesthesia. A closed-eye, modified Schirmer test was performed bilaterally in 8 normal subjects, in a controlled environment chamber set to 23°C, 45% relative humidity, and 0.08 m/s airflow. Eye drops were instilled into each eye 10 minutes before the Schirmer test. Experiments were as follows: 1) bilateral saline (control), 2) unilateral anesthesia (ipsilateral anesthetic; contralateral saline), and 3) bilateral anesthesia. There was no difference in between-eye wetting lengths in the saline control eyes (P = 0.394) or the bilaterally anesthetized eyes (P = 0.171). The wetting length was reduced in both eyes after bilateral anesthesia compared with saline controls (P = 0.001; P ≤ 0.0005). After unilateral anesthesia, the wetting length was reduced in the anesthetized eye compared with its saline control by 51.4% (P ≤ 0.0005) and compared with its fellow, unanesthetized eye (P = 0.005). The fellow eye value was also reduced compared with its saline control (P = 0.06). The wetting length was reduced by topical anesthesia, when instilled bilaterally and ipsilaterally. The latter response implies an ipsilateral, reflex sensory drive to lacrimal secretion. In the unanesthetized fellow eye, the reduction compared with its saline control was not quite significant. This implies a relative lack of central, sensory, reflex cross-innervation, although the possibility cannot entirely be ruled out. These results are relevant to the possibility of reflex lacrimal compensation from a normal fellow eye, in cases of unilateral corneal anesthesia.

EFFECTS OF TOPICAL CORTICOSTEROID ADMINISTRATION ON INTRAOCULAR PRESSURE IN NORMAL AND GLAUCOMATOUS CATS

PubMed Central

Gosling, Allyson A; Kiland, Julie A; Rutkowski, Lauren E; Hoefs, Adam; Ellinwood, N Matthew; McLellan, Gillian J

2016-01-01

Objective to determine the effect of topical corticosteroid (CCS) therapy on intraocular pressure (IOP) in normal cats and cats with primary feline congenital glaucoma (FCG). Animals studied 5 normal and 11 FCG cats were studied in 2 cohorts. Procedures IOP was measured by a single, masked observer, once daily 3–5 days/week throughout the course of CCS treatment and for up to 11 days after treatment discontinuation. One eye per cat was randomly assigned for treatment twice daily with CCS; Balanced salt solution (BSS) applied to the contralateral eye, served as a control. Differences between eyes and between weeks of the study period were calculated for each cat. A positive response to CCS was defined as a consistent >15% or >25% higher IOP in the treated relative to control eye in normal and FCG cats, respectively. Results 8/11 FCG cats responded to topical CCS after 1–5 weeks of treatment with an increase in IOP relative to the untreated eye (maximum IOP discrepancy of 56 mmHg). 2/5 normal cats responded to topical CCS with appreciable but clinically unimportant increase in IOP in the treated eye (maximum IOP discrepancy of 6.4 mmHg). Conclusions our data indicate that the incidence of steroid induced IOP elevation in cats is lower than previously published feline studies suggest. Cats with pre-existing compromise in aqueous humor outflow may show a greater, clinically relevant response to topical CCS than normal cats. PMID:26876736

The mucosal surfaces of both eyes are immunologically linked by a neurogenic inflammatory reflex involving TRPV1 and substance P.

PubMed

Guzmán, Mauricio; Miglio, Maximiliano S; Zgajnar, Nadia R; Colado, Ana; Almejún, María B; Keitelman, Irene A; Sabbione, Florencia; Fuentes, Federico; Trevani, Analía S; Giordano, Mirta N; Galletti, Jeremías G

2018-06-04

Immunological interdependence between the two eyes has been reported for the cornea and the retina but not for the ocular mucosal surface. Intriguingly, patients frequently report ocular surface-related symptoms in the other eye after unilateral ocular surgery. Here we show how unilateral eye injuries in mice affect the mucosal immune response of the opposite ocular surface. We report that, despite the lack of lymphatic cross-drainage, a neurogenic inflammatory reflex in the contralateral conjunctiva is sufficient to increase, first, epithelial nuclear factor kappa B signaling, then, dendritic cell maturation, and finally, expansion of effector, instead of regulatory, T cells in the draining lymph node, leading to disrupted ocular mucosal tolerance. We also show that damage to ocular surface nerves is required. Using pharmacological inhibitors and agonists, we identified transient receptor potential vanilloid 1 (TRPV1) channel as the receptor sensing tissue damage in the injured eye and substance P released in the opposite ocular surface as the effector of the sympathetic response. Finally, blocking either step prevented subsequent ocular allergic reactions in the opposite eye in a unilateral corneal alkali burn model. This study demonstrates that both ocular surfaces are immunologically linked and suggests potential therapeutic targets for intervention.

Visual and refractive outcomes of LASIK with the SCHWIND ESIRIS and WaveLight ALLEGRETTO WAVE Eye-q excimer lasers: a prospective, contralateral study.

PubMed

Mearza, Ali A; Muhtaseb, Mohammed; Aslanides, Ioannis M

2008-11-01

To compare the safety, efficacy, and predictability of LASIK with the SCHWIND ESIRIS and WaveLight ALLEGRETTO WAVE Eye-Q excimer laser platforms. This prospective study comprised 44 eyes of 22 consecutive patients who were treated with LASIK using the Moria M2 microkeratome. One eye was treated with the SCHWIND ESIRIS laser and the fellow eye treated with the WaveLight ALLEGRETTO WAVE Eye-Q laser. All eyes operated with the SCHWIND ESIRIS were treated with standard aspheric ablation, whereas the eyes operated with the WaveLight ALLEGRETTO WAVE Eye-Q received treatment with three different ablation types according to the common practice at our clinic. Outcome measures were uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction, and proximity to target refraction at 6-month follow-up. At 6 months postoperative, mean decimal UCVA was 0.96+/-0.22 (range: 0.3 to 1.2) for ESIRIS eyes and 0.98+/-0.17 (range: 0.6 to 1.2) for ALLEGRETTO eyes (P=.57). Mean postoperative spherical equivalent refraction was -0.02+/-0.28 diopters (D) (range: -0.75 to +0.75 D) for ESIRIS eyes and 0.11+/-0.91 D (range: -1.00 to +3.88 D) for ALLEGRETTO eyes (P=.49). Of the ESIRIS eyes, 20/22 (91%) were within +/-1.00 D of target refraction and 20/22 (91%) were within +/-0.50 D of target refraction. Of the ALLEGRETTO eyes, 20/22 (91%) and 19/22 (86%) were within +/-1.00 D and +/-0.50 D, respectively, of target refraction. No patient lost > or =2 lines of BSCVA in either group. No differences were seen in safety and efficacy outcome parameters between the SCHWIND ESIRIS and WaveLight ALLEGRETTO WAVE Eye-Q excimer lasers when used according to a previously established treatment algorithm at our clinic in the treatment of refractive error.

Postnatal development of retinal projections in the brushtailed possum, Trichosurus vulpecula.

PubMed

Sanderson, K J; Dixon, P G; Pearson, L J

1982-10-01

The postnatal development of retinal projections was studied in the brushtailed possum, Trichosurus vulpecula. [3H]proline was injected into one eye of 13 young possums aged 24-84 days in order to trace retinal pathways. The dorsal lateral geniculate nucleus (LGNd) can be identified in Nissl material at 19 days but not at 9-10 days. By 40 days some cytoarchitectural lamination of the LGNd is apparent and by 71 days the adult pattern of cell layers is present. At 24 days retinal fibers occupy by lateral part of the LGNd on both sides of the brain. By 38-40 days the retinal fibers fill be contralateral LGNd and the binocular part of the ipsilateral LGNd and there is a beginning of the segregation of retinal fibers into left and right eye territories. By 49-50 days a partial segregation is achieved, and complete segregation by 71 days. At 9-10 days the superior colliculus is not differentiated into layers and there is a thick zone of cell proliferation around the ventricle. By 23 days the superior colliculus has well-defined cell layers and there is still some indication of cell proliferation around the ventricle. By 40 days, the superior colliculus shows little evidence of cell proliferation. At 24 days retinal fibers fill the superficial layers of the contralateral optic tectum and are lightly distributed through the superficial layers of the rostral half of the ipsilateral tectum. By 38 days the ipsilateral retinal input is restricted to the deeper layers of the tectum. These results show that the adult pattern of retinal projections to the LGNd and optic tectum develops a number of weeks before eye opening occurs (at 90-120 days).

Electrophysiological recordings in humans reveal reduced location-specific attentional-shift activity prior to recentering saccades

PubMed Central

Boehler, C. Nicolas; Zhang, Helen H.; Schoenfeld, Mircea A.; Woldorff, Marty G.

2012-01-01

Being able to effectively explore the visual world is of fundamental importance, and it has been suggested that the straight-ahead gaze position within the egocentric reference frame (“primary position”) might play a special role in this context. In the present study we employed human electroencephalography (EEG) to examine neural activity related to the spatial guidance of saccadic eye movements. Moreover, we sought to investigate whether such activity would be modulated by the spatial relation of saccade direction to the primary gaze position (recentering saccades). Participants executed endogenously cued saccades between five equidistant locations along the horizontal meridian. This design allowed for the comparison of isoamplitude saccades from the same starting position that were oriented either toward the primary position (centripetal) or further away from it (centrifugal). By back-averaging time-locked to the saccade onset on each trial, we identified a parietally distributed, negative-polarity EEG deflection contralateral to the direction of the upcoming saccade. Importantly, this contralateral presaccadic negativity, which appeared to reflect the location-specific attentional guidance of the eye movement, was attenuated for recentering saccades relative to isoamplitude centrifugal saccades. This differential electrophysiological signature was paralleled by faster saccadic reaction times and was substantially more apparent when time-locking the data to the onset of the saccade rather than to the onset of the cue, suggesting a tight temporal association with saccade initiation. The diminished level of this presaccadic component for recentering saccades may reflect the preferential coding of the straight-ahead gaze position, in which both the eye-centered and head-centered reference frames are perfectly aligned and from which the visual world can be effectively explored. PMID:22157127

Evaluating the efficacy of epinastine ophthalmic solution using a conjunctivitis allergen challenge model in patients with birch pollen allergic conjunctivitis.

PubMed

Tagawa, Yoshiaki; Namba, Kenichi; Nakazono, Yumi; Iwata, Daiju; Ishida, Susumu

2017-04-01

The efficacy of epinastine 0.05% ophthalmic solution for pollen allergic conjunctivitis has already been shown in a conjunctival allergen challenge (CAC) test using cedar pollen as a challenge. The present study investigated the efficacy of this solution against birch pollen conjunctivitis in a CAC test. Ten adult subjects (eight males and two females) with asymptomatic birch pollen conjunctivitis were enrolled in this study. The average age of the subjects was 41.1 years. This study was conducted during a period without birch pollen dispersion. In each subject, the epinastine 0.05% ophthalmic solution was instilled in one eye, and an artificial tear fluid was instilled in the fellow eye in a double-blind manner. Five minutes or 4 h after the drug instillation, both eyes were challenged with an optimal concentration of birch pollen, and ocular itching and conjunctival hyperemia were then graded. Tears were collected before the drug instillation and 20 min after the pollen challenge, and the histamine level was measured. The ocular itching scores and palpebral conjunctival hyperemia scores of the epinastine-treated eyes were significantly lower than those of the contralateral control eyes when the eyes were pretreated with the drug 4 h before the CAC. There was a significant correlation between the tear histamine level and mean ocular itching score of three time points (3, 5 and 10 min) following the CAC in the control eyes but not the epinastine-treated eyes. Epinastine is effective in suppressing ocular itching and conjunctival hyperemia in birch pollen conjunctivitis. Copyright © 2017 Japanese Society of Allergology. Production and hosting by Elsevier B.V. All rights reserved.

The role of amniotic membrane extract eye drop (AMEED) in in vivo cultivation of limbal stem cells.

PubMed

Baradaran-Rafii, Alireza; Asl, Niloufar Shayan; Ebrahimi, Marzieh; Jabbehdari, Sayena; Bamdad, Shahram; Roshandel, Danial; Eslani, Medi; Momeni, Maryam

2018-01-01

Limbal stem cell transplantation (LSCT) is the definitive treatment for total limbal stem cell deficiency (LSCD). This study evaluates the anatomical and visual outcomes of a surgical technique supplemented by amniotic membrane extract eye drop (AMEED) for in vivo cultivation of limbal stem cells (LSCs). One small limbal block (2 × 1 mm) harvested from the contralateral healthy eye was transferred to the diseased eye, which had been already covered by cryopreserved amniotic membrane (N = 20). The patients were categorized into case and control groups. AMEED was administered postoperatively only for patients in the case group (N = 14). Sequential penetrating keratoplasty (PKP) was performed in 4 eyes of the case group for optical clarity. Visual acuity, epithelial healing, corneal clarity and regression of conjunctivalization/vascularization were evaluated after surgery. The corneal buttons of post-PKP eyes were evaluated for LSC markers. In the case group, the mean corrected distance visual acuity (CDVA) was 20/400 before surgery, which improved to 20/40 and 20/50 at the last follow-up in eyes with and without PKP, respectively. Epithelial defects healed in all eyes of the case group during 2 weeks after surgery. Corneal conjunctivalization/vascularization regressed dramatically in all patients of the case group 2-3 months after surgery. In PKP cases, all transplanted corneas were clear at the last follow-up. LSC markers were expressed on the surface of all trephined corneal buttons. All eyes in the control group developed persistent epithelial defect. This study suggests that amniotic membrane extract may be helpful for in vivo cultivation of limbal stem cells. Copyright © 2017 Elsevier Inc. All rights reserved.

[Contralateral Recession of the Inferior Oblique Muscle in Grave's Disease Patients with Mild M. rectus inferior fibrosis].

PubMed

Eckstein, A; Raczynski, S; Dekowski, D; Esser, J

2015-10-01

The aim of this study was to evaluate the dose effect and the resulting binocular single vision for inferior oblique muscle recession in patients with Grave's orbitopathy. The evaluation covered all patients (n = 13) between 2010-2013 treated with recession of the inferior oblique muscle for vertical deviation caused by inferior fibrosis of the contralateral eye. The inclusion criterion was a small vertical squint angle with excyclotorsion. The corrected vertical squint angle was 3.75° [7 pdpt] (median, min 1.5° [3 pdpt], max 8° [16 pdpt]) in primary position and 5.5° in adduction [11pdpt] (median, min 3°[6 pdpt], max 9°[18pdpt]). Excyclotorsion was 4° [8 pdpt] (median, min 1° [2 pdpt], max 9° [18 pdpt]). Elevation was only slightly impaired and the side difference was 5° (median). The recession distance was preoperatively determined: 0.5° squint angle reduction per mm recession distance (calculation from patients who received surgery before 2010). Inferior oblique recession generated a good field of binocular single vision (BSV) for all patients. All patients reached BSV in the central area (20°) and within 30° of downgaze. Sixty nine percent of the patients were completely diplopia free in downgaze. Diplopia persisted in more than half of the patients in up gaze outside 15°. Squint reduction was 0.5° [1 pdpt] [0.45-0.67]/per mm recession distance in primary position and 0.65° [1.3 pdpt] [0.55-0.76]/per mm for the vertical deviation in adduction. Excyclotorsion was reduced to ≤ 2° in 77 % of the patients. Inferior oblique muscle recession can be very successfully performed on the contralateral eye in patients with mild inferior rectus muscle fibrosis. Surgery at the contralateral yoke muscle prevents the risk of overeffect with resulting diplopia in downgaze, which could occur if small distance recession had been performed at the inferior rectus muscle. An overeffect in relation to inferior oblique recession will only cause diplopia in upgaze, which is much less troublesome in daily routine. Georg Thieme Verlag KG Stuttgart · New York.

Topography-modified refraction (TMR): adjustment of treated cylinder amount and axis to the topography versus standard clinical refraction in myopic topography-guided LASIK.

PubMed

Kanellopoulos, Anastasios John

2016-01-01

To evaluate the safety, efficacy, and contralateral eye comparison of topography-guided myopic LASIK with two different refraction treatment strategies. Private clinical ophthalmology practice. A total of 100 eyes (50 patients) in consecutive cases of myopic topography-guided LASIK procedures with the same refractive platform (FS200 femtosecond and EX500 excimer lasers) were randomized for treatment as follows: one eye with the standard clinical refraction (group A) and the contralateral eye with the topographic astigmatic power and axis (topography-modified treatment refraction; group B). All cases were evaluated pre- and post-operatively for the following parameters: refractive error, best corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UDVA), topography (Placido-disk based) and tomography (Scheimpflug-image based), wavefront analysis, pupillometry, and contrast sensitivity. Follow-up visits were conducted for at least 12 months. Mean refractive error was -5.5 D of myopia and -1.75 D of astigmatism. In group A versus group B, respectively, the average UDVA improved from 20/200 to 20/20 versus 20/16; post-operative CDVA was 20/20 and 20/13.5; 1 line of vision gained was 27.8% and 55.6%; and 2 lines of vision gained was 5.6% and 11.1%. In group A, 27.8% of eyes had over -0.50 diopters of residual refractive astigmatism, in comparison to 11.7% in group B ( P <0.01). The residual percentages in both groups were measured with refractive astigmatism of more than -0.5 diopters. Topography-modified refraction (TMR): topographic adjustment of the amount and axis of astigmatism treated, when different from the clinical refraction, may offer superior outcomes in topography-guided myopic LASIK. These findings may change the current clinical paradigm of the optimal subjective refraction utilized in laser vision correction.

Topography-modified refraction (TMR): adjustment of treated cylinder amount and axis to the topography versus standard clinical refraction in myopic topography-guided LASIK

PubMed Central

Kanellopoulos, Anastasios John

2016-01-01

Purpose To evaluate the safety, efficacy, and contralateral eye comparison of topography-guided myopic LASIK with two different refraction treatment strategies. Setting Private clinical ophthalmology practice. Patients and methods A total of 100 eyes (50 patients) in consecutive cases of myopic topography-guided LASIK procedures with the same refractive platform (FS200 femtosecond and EX500 excimer lasers) were randomized for treatment as follows: one eye with the standard clinical refraction (group A) and the contralateral eye with the topographic astigmatic power and axis (topography-modified treatment refraction; group B). All cases were evaluated pre- and post-operatively for the following parameters: refractive error, best corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UDVA), topography (Placido-disk based) and tomography (Scheimpflug-image based), wavefront analysis, pupillometry, and contrast sensitivity. Follow-up visits were conducted for at least 12 months. Results Mean refractive error was −5.5 D of myopia and −1.75 D of astigmatism. In group A versus group B, respectively, the average UDVA improved from 20/200 to 20/20 versus 20/16; post-operative CDVA was 20/20 and 20/13.5; 1 line of vision gained was 27.8% and 55.6%; and 2 lines of vision gained was 5.6% and 11.1%. In group A, 27.8% of eyes had over −0.50 diopters of residual refractive astigmatism, in comparison to 11.7% in group B (P<0.01). The residual percentages in both groups were measured with refractive astigmatism of more than −0.5 diopters. Conclusion Topography-modified refraction (TMR): topographic adjustment of the amount and axis of astigmatism treated, when different from the clinical refraction, may offer superior outcomes in topography-guided myopic LASIK. These findings may change the current clinical paradigm of the optimal subjective refraction utilized in laser vision correction. PMID:27843292

Dry eyes and corneal sensation after laser in situ keratomileusis with femtosecond laser flap creation Effect of hinge position, hinge angle, and flap thickness.

PubMed

Mian, Shahzad I; Li, Amy Y; Dutta, Satavisha; Musch, David C; Shtein, Roni M

2009-12-01

To determine whether corneal sensation and dry-eye signs and symptoms after myopic laser in situ keratomileusis (LASIK) surgery with a femtosecond laser are affected by varying hinge position, hinge angle, or flap thickness. University-based academic practice, Ann Arbor, Michigan, USA. This prospective randomized contralateral-eye study evaluated eyes after bilateral myopic LASIK with a femtosecond laser (IntraLase). Superior and temporal hinge positions, 45-degree and 90-degree hinge angles, and 100 microm and 130 microm corneal flap thicknesses were compared. Postoperative follow-up at 1 week and 1, 3, 6, and 12 months included central Cochet-Bonnet esthesiometry, the Ocular Surface Disease Index questionnaire, a Schirmer test with anesthesia, tear breakup time (TBUT), corneal fluorescein staining, and conjunctival lissamine green staining. The study evaluated 190 consecutive eyes (95 patients). Corneal sensation was reduced at all postoperative visits, with improvement over 12 months (P<.001). There was no difference in corneal sensation between the different hinge positions, angles, or flap thicknesses at any time point. The overall ocular surface disease index score was increased at 1 week, 1 month, and 3 months (P<.0001, P<.0001, and P = .046, respectively). The percentage of patients with a TBUT longer than 10 seconds was significantly lower at 1 week and 1 month (P<.0001). Dry-eye syndrome after myopic LASIK with a femtosecond laser was mild and improved after 3 months. Corneal flap hinge position, hinge angle, and thickness had no effect on corneal sensation or dry-eye syndrome.

Radiation treatment inhibits monocyte entry into the optic nerve head and prevents neuronal damage in a mouse model of glaucoma.

PubMed

Howell, Gareth R; Soto, Ileana; Zhu, Xianjun; Ryan, Margaret; Macalinao, Danilo G; Sousa, Gregory L; Caddle, Lura B; MacNicoll, Katharine H; Barbay, Jessica M; Porciatti, Vittorio; Anderson, Michael G; Smith, Richard S; Clark, Abbot F; Libby, Richard T; John, Simon W M

2012-04-01

Glaucoma is a common ocular disorder that is a leading cause of blindness worldwide. It is characterized by the dysfunction and loss of retinal ganglion cells (RGCs). Although many studies have implicated various molecules in glaucoma, no mechanism has been shown to be responsible for the earliest detectable damage to RGCs and their axons in the optic nerve. Here, we show that the leukocyte transendothelial migration pathway is activated in the optic nerve head at the earliest stages of disease in an inherited mouse model of glaucoma. This resulted in proinflammatory monocytes entering the optic nerve prior to detectable neuronal damage. A 1-time x-ray treatment prevented monocyte entry and subsequent glaucomatous damage. A single x-ray treatment of an individual eye in young mice provided that eye with long-term protection from glaucoma but had no effect on the contralateral eye. Localized radiation treatment prevented detectable neuronal damage and dysfunction in treated eyes, despite the continued presence of other glaucomatous stresses and signaling pathways. Injection of endothelin-2, a damaging mediator produced by the monocytes, into irradiated eyes, combined with the other glaucomatous stresses, restored neural damage with a topography characteristic of glaucoma. Together, these data support a model of glaucomatous damage involving monocyte entry into the optic nerve.

Planer orientation of the bilateral semicircular canals in dizzy patients.

PubMed

Aoki, Sachiko; Takei, Yasuhiko; Suzuki, Kazufumi; Masukawa, Ai; Arai, Yasuko

2012-10-01

Recent development of 3-dimensional analysis of eye movement enabled to detect the eye rotation axis, which is used to determine the responsible semicircular canal(s) in dizzy patients. Therefore, the knowledge of anatomical orientation of bilateral semicircular canals is essential, as all 6 canals influence the eye movements. Employing the new head coordinate system suitable for MR imaging, we calculated the angles of semicircular canal planes of both ears in 11 dizzy patients who had normal caloric response in both ears. The angles between adjacent canal pairs were nearly perpendicular in both ears. The angle between the posterior canal planes and head sagittal plane was 51° and significantly larger the angle between the anterior canal planes and head sagittal plane, which was 35°. The angle between the horizontal canal plane and head sagittal plane was almost orthogonal. Pairs of contralateral synergistic canal planes were not parallel, forming 10° between right and left horizontal canal planes, 17° between right anterior and left posterior canal planes and 19° between the right posterior and left anterior canal planes. Our measurement of the angles of adjacent canal pairs and the angle between each semicircular canal and head sagittal plane coincided with those of previous reports obtained from CT images and skull specimens. However, the angles between contralateral synergistic canal planes were more parallel than those of previous reports. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Effect of iris registration on outcomes of FEMTOLASIK for myopia and myopic astigmatism.

PubMed

Ghoreishi, Mohammad; Beni, Zahra Naderi; Beni, Afsaneh Naderi; Kianersi, Farzan

2017-09-05

To compare the visual and refractive outcomes after FEMTOLASIK with and without iris registration. In this randomized, prospective, comparative, contralateral eye study, 118 eyes of 59 patients with myopia and myopic astigmatism underwent LASIK using the Femto LDV femtosecond laser (160 µm) and the MEL80 with or without iris registration. For each patient, iris registration FEMTOLASIK was performed on one eye and non-iris registration FEMTOLASIK was performed on the other eye, assigned at random. Patients were evaluated before and 12 months. Uncorrected visual acuity, best-corrected visual acuity, manifest refraction, contrast sensitivity, and higher-order aberrations (HOAs) were evaluated. At 12 months, the mean UDVA was 0.002 ± 0.07 logMAR (20/19) in iris registration eyes and 0.00 ± 0.06 logMAR (20/24) in non-iris registration eyes (P = 0.9). 61% of iris registration eyes and 71.2% of non-iris registration eyes achieved a UDVA of 20/20 or better (P = 0.31); 98.3% of eyes with the iris registration FEMTOLASIK and 94.9% with the non-iris registration FEMTOLASIK were within ±0.50 D from emmetropia (P = 0.71). No statistically significant difference was found in postoperative contrast sensitivity between groups at 3, 6, 12, or 18 cycles/degree (P > 0.05). There was significant increase in total HOA root mean square in two groups. The mean error magnitude of surgically induced astigmatism 12 months postoperatively was -0.33 in iris registration eyes and -0.24 in the non-iris registration eyes (P = 0.36). FEMTOLASIK with and without iris registration provides similar results in myopic and myopic astigmatism patients.

Treatment with galectin-1 eye drops regulates mast cell degranulation and attenuates the severity of conjunctivitis.

PubMed

Mello-Bosnic, Claudia; Gimenes, Alexandre Dantas; Oliani, Sonia Maria; Gil, Cristiane Damas

2018-05-31

Galectin-1 (Gal-1) is a β-galactoside-binding protein with diverse biological activities in the pathogenesis of inflammation, however the mechanisms by which Gal-1 modulates cellular responses in allergic inflammatory processes have not been fully determined. In this study, we evaluated the therapeutic potential of Gal-1 eye drops in an experimental model of conjunctivitis. Wistar rats received a topical application of compound (C)48/80 (100 mg/ml) into right eyes and a drop of vehicle into the contralateral eye. Another group of rats received Gal-1 (0.3 or 3 μg/eye) or sodium cromoglycate (SCG; 40 mg/ml) in both eyes and, after 15 min, right eye was challenged with C48/80. Conjunctivitis-induced by C48/80 was characterized by severe eyelid oedema and tearing, but clinical signs were ameliorated by eye drop doses of both Gal-1 (0.3/3 μg) and SCG. As expected, an increased proportion of degranulated mast cells (62%, P < 0.01) and lower histamine levels were observed after 6 h of C48/80 challenge, compared to control (32%). This effect was abrogated by Gal-1 and SCG, which reduced mast cell degranulation (31-36%), eosinophil migration and eosinophil peroxidase levels in the eyes. Gal-1 (3 μg) and SCG treatments also decreased IL-4 levels, as well as activation of mitogen activated protein kinases compared to untreated C48/80 eyes. Our findings suggest that Gal-1 eye drops represent a new therapeutic strategy for ocular allergic inflammation. Copyright © 2018 Elsevier B.V. All rights reserved.

Efficacy of Intravitreal injection of 2-Methoxyestradiol in regression of neovascularization of a retinopathy of prematurity rat model.

PubMed

Said, Azza Mohamed Ahmed; Zaki, Rania Gamal Eldin; Salah Eldin, Rania A; Nasr, Maha; Azab, Samar Saad; Elzankalony, Yaser Abdelmageuid

2017-04-04

Retinopathy of prematurity (ROP) is one of the targets for early detection and treatment to prevent childhood blindness in world health organization programs. The purpose of study was to evaluate the efficacy of intravitreal injection of 2-Methoxyestradiol (2-ME) nanoemulsion in regressing neovascularization of a ROP rat model. A prospective comparative case - control animal study conducted on 56 eyes of 28 healthy new born Sprague Dawley male albino rat. ROP was induced in 21 rats then two concentrations of 2-ME nanoparticles were injected in right eyes of 14 rats (low dose; study group I, high dose; study group II). A blank nanoemulsion was injected in the right eyes of seven rats (control positive group I). No injections performed in contralateral left eyes (control positive group II). Seven rats (14 eyes) were kept in room air (control negative group). On postnatal day 17, eyeballs were enucleated. Histological structure of the retina was examined using Hematoxylin and eosin staining. Vascular endothelial growth factor (VEGF) and glial fibrillary acidic protein (GFAP) expressions were detected by immunohistochemical studies. Intravitreal injection of 2-ME (in the two concentrations) caused marked regression of the new vascular tufts on the vitreal side with normal organization and thickness of the retina especially in study group II, which also show negative VEGF immunoreaction. Positive GFAP expression was detected in the control positive groups and study group (I). Intravitreal injection of 2-Methoxyestradiol nanoemulsion is a promising effective method in reduction of neovascularization of a ROP rat model.

Comparative analysis of two femtosecond LASIK platforms using iTRAQ quantitative proteomics.

PubMed

D'Souza, Sharon; Petznick, Andrea; Tong, Louis; Hall, Reece C; Rosman, Mohamad; Chan, Cordelia; Koh, Siew Kwan; Beuerman, Roger W; Zhou, Lei; Mehta, Jodhbir S

2014-05-06

New femtosecond laser platforms may reduce ocular surface interference and LASIK-associated dry eye. This study investigated tear protein profiles in subjects who underwent LASIK using two femtosecond lasers to assess differences in protein expression. This was a randomized interventional clinical trial involving 22 patients who underwent femtosecond laser refractive surgery with a contralateral paired eye design. Corneal flaps of 22 subjects were created by either Visumax or Intralase laser. Tear samples were collected preoperatively, and at 1 week and 3 months postoperatively using Schirmer's strips. Tear protein ratios were calculated relative to preoperative protein levels at baseline. The main outcome measures were the levels of a panel of dry eye protein markers analyzed using isobaric tagging for relative and absolute quantitation (iTRAQ) mass spectrometry. A total of 824 unique proteins were quantifiable. Tear protein ratios were differentially regulated between the eyes treated with different lasers. The secretoglobulins Lipophilin A (1.80-fold) and Lipophilin C (1.77) were significantly upregulated (P < 0.05) at 1 week postoperatively in Visumax but not in Intralase-treated eyes. At 1 week, orosomucoid1 was upregulated (1.78) in Intralase but not Visumax-treated eyes. In the same eyes, lysozyme, cathepsin B, and lipo-oxygenase were downregulated at 0.44-, 0.64-, and 0.64-folds, respectively. Transglutaminase-2 was downregulated in both groups of eyes. Different laser platforms induce distinct biological responses in the cornea and ocular surface, which manifests as different levels of tear proteins. This study has implications for surgical technology and modulation of wound healing responses. (ClinicalTrials.gov number, NCT01252654.). Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Changes of the eye optics after iris constriction☆

PubMed Central

Montés-Micó, Robert; Hernández, Patricio; Fernández-Sánchez, Vicente; Bonaque, Sergio; Lara, Francisco; López-Gil, Norberto

2011-01-01

Purpose To evaluate the possible change in the optics of the human eye after iris constriction. Methods Ocular aberrations were measured under natural viewing conditions in 26 eyes. The measured eyes fixated on a dim target while the contralateral eye was either occluded (so the measured eye had a large pupil) or highly illuminated (so the measured eye had a small pupil). The measured eyes fixated to a dim target placed 0.5 D beyond the subject’s far point. Zernike values obtained in both situations were compared within the same pupil diameter corresponding to the one obtained under the high illumination condition. Results Significant variation in some aberration coefficients were found between the two illumination conditions. Specially, spherical aberration (SA) increased significantly after pupil miosis (P = .0017). The mean increase of SA measured was 0.018 microns, for a 3-mm pupil. Mean values of other ocular aberrations also vary significantly after pupil miosis (changes were larger than the standard deviation of the repeated measurements). A mean paraxial hyperopic shift of one third of diopter was found after iris constriction. Conclusion Iris constriction slightly modifies the optics of the eye. The small hyperopic shift of the best image plane after iris constriction may be explained by a change in the lens shape and/or position.

Verification of Embolic Channel Causing Blindness Following Filler Injection.

PubMed

Tansatit, Tanvaa; Moon, Hyoung Jin; Apinuntrum, Prawit; Phetudom, Thavorn

2015-02-01

Ocular complications following cosmetic filler injections are serious situations. This study provided scientific evidence that filler in the facial and the superficial temporal arteries could enter into the orbits and the globes on both sides. We demonstrated the existence of an embolic channel connecting the arterial system of the face to the ophthalmic artery. After the removal of the ocular contents from both eyes, liquid dye was injected into the cannulated channel of the superficial temporal artery in six soft embalmed cadavers and different color dye was injected into the facial artery on both sides successively. The interior sclera was monitored for dye oozing from retrograde ophthalmic perfusion. Among all 12 globes, dye injections from the 12 superficial temporal arteries entered ipsilateral globes in three and the contralateral globe in two arteries. Dye from the facial artery was infused into five ipsilateral globes and in three contralateral globes. Dye injections of two facial arteries in the same cadaver resulted in bilateral globe staining but those of the superficial temporal arteries did not. Direct communications between the same and different arteries of the four cannulated arteries were evidenced by dye dripping from the cannulating needle hubs in 14 of 24 injected arteries. Compression of the orbital rim at the superior nasal corner retarded ocular infusion in 11 of 14 arterial injections. Under some specific conditions favoring embolism, persistent interarterial anastomoses between the face and the eye allowed filler emboli to flow into the globe causing ocular complications.

Resistance to blood flow in the rabbit ophthalmic artery after topical treatment with timolol.

PubMed

Liu, John H K; Li, Ruixia; Nelson, Thomas R; Weinreb, Robert N

2007-04-01

The aim of this study was to investigate the resistance to blood flow in the ophthalmic artery of rabbits receiving topical treatment with timolol. Eight (8) New Zealand albino rabbits received 20 mul of timolol treatment (vehicle, 0.1%, 0.33%, 1%, and 3.3%) on the right eye. Blood-flow velocity in the ophthalmic artery was determined in the treated eye using color Doppler imaging (CDI) with a 12-MHz linear ultrasound transducer prior to the treatment and at 0.5, 1, 1.5, 2, and 3 h after the treatment. Intraocular pressure (IOP) was measured in both eyes, using a pneumatonometer at the same time points. Pourcelot's resistive index of blood flow was calculated, using the peak systolic velocity and the end diastolic velocity. A control experiment was performed with CDI obtained from the right eye when the left eye was treated with 1% timolol. In the eye treated with 1% and 3.3% timolol, a dose-dependent increase in the resistive index of blood flow occurred in the ophthalmic artery. No change in the resistive index occurred when the contralateral eye was treated with 1% timolol. Changes of IOP were not different between the two eyes under all the experimental conditions. Timolol, at all concentrations, caused a significant reduction of heart rate. A similar reduction of heart rate occurred when either eye was treated with 1% timolol. Topical treatment with timolol in rabbits can increase the resistance to blood flow in the ophthalmic artery. This effect is caused by a mechanism local to the eye and is not dependent on an IOP change.

Assessing visual requirements for social context-dependent activation of the songbird song system

PubMed Central

Hara, Erina; Kubikova, Lubica; Hessler, Neal A.; Jarvis, Erich D.

2008-01-01

Social context has been shown to have a profound influence on brain activation in a wide range of vertebrate species. Best studied in songbirds, when males sing undirected song, the level of neural activity and expression of immediate early genes (IEGs) in several song nuclei is dramatically higher or lower than when they sing directed song to other birds, particularly females. This differential social context-dependent activation is independent of auditory input and is not simply dependent on the motor act of singing. These findings suggested that the critical sensory modality driving social context-dependent differences in the brain could be visual cues. Here, we tested this hypothesis by examining IEG activation in song nuclei in hemispheres to which visual input was normal or blocked. We found that covering one eye blocked visually induced IEG expression throughout both contralateral visual pathways of the brain, and reduced activation of the contralateral ventral tegmental area, a non-visual midbrain motivation-related area affected by social context. However, blocking visual input had no effect on the social context-dependent activation of the contralateral song nuclei during female-directed singing. Our findings suggest that individual sensory modalities are not direct driving forces for the social context differences in song nuclei during singing. Rather, these social context differences in brain activation appear to depend more on the general sense that another individual is present. PMID:18826930

Human corneal epithelial cell shedding and fluorescein staining in response to silicone hydrogel lenses and contact lens disinfecting solutions.

PubMed

Gorbet, Maud; Peterson, Rachael; McCanna, David; Woods, Craig; Jones, Lyndon; Fonn, Desmond

2014-03-01

A pilot study was conducted to evaluate human corneal epithelial cell shedding in response to wearing a silicone hydrogel contact lens/solution combination inducing corneal staining. The nature of ex vivo collected cells staining with fluorescein was also examined. A contralateral eye study was conducted in which up to eight participants were unilaterally exposed to a multipurpose contact lens solution/silicone hydrogel lens combination previously shown to induce corneal staining (renu® fresh™ and balafilcon A; test eye), with the other eye using a combination of balafilcon A soaked in a hydrogen peroxide care system (Clear Care®; control eye). Lenses were worn for 2, 4 or 6 hours. Corneal staining was graded after lens removal. The Ocular Surface Cell Collection Apparatus was used to collect cells from the cornea and the contact lens. In the test eye, maximum solution-induced corneal staining (SICS) was observed after 2 hours of lens wear (reducing significantly by 4 hours; p < 0.001). There were significantly more cells collected from the test eye after 4 hours of lens wear when compared to the control eye and the collection from the test eye after 2 hours (for both; n = 5; p < 0.001). The total cell yield at 4 hours was 813 ± 333 and 455 ± 218 for the test and control eyes, respectively (N = 5, triplicate, p = 0.003). A number of cells were observed to have taken up the fluorescein dye from the initial fluorescein instillation. Confocal microscopy of fluorescein-stained cells revealed that fluorescein was present throughout the cell cytoplasm and was retained in the cells for many hours after recovery from the corneal surface. This pilot study indicates that increased epithelial cell shedding was associated with a lens-solution combination which induces SICS. Our data provides insight into the transient nature of the SICS reaction and the nature of fluorescein staining observed in SICS.

Hydrogel keratophakia: a microkeratome dissection in the monkey model.

PubMed Central

Beekhuis, W H; McCarey, B E; Waring, G O; van Rij, G

1986-01-01

High water content intracorneal implants were fabricated from Vistamarc hydrogel (Vistakon, Inc.) at 58%, 68%, and 72% water content and a range of powers from +7.25 to +17.00 dioptres. The Barraquer microkeratome technique was used to implant the lens at 59.0 +/- 9% (+/- SD) depth in the corneas of 14 rhesus monkey eyes. The contralateral eye served as a control. Three eyes were lost to the study because of complications. The remaining 11 animals were followed up for 51 +/- 2 weeks with the refractive yield being 118 +/- 34% and the keratometric yield being 92 +/- 30%. The measured and theoretically expected refractive changes have a linear regression line correlation coefficient of 0.74, whereas the respective keratometric data had a correlation coefficient of 0.04. The measured refraction became stable within 2 to 3 dioptres after 20 postoperative weeks. The hydrogels were well tolerated within the corneal tissue. There was a minimum of interface problems except along the edge of the implant. Implants with abruptly cut edges versus a fine wedge tended to have more light scattering collagen at the implant margin. PMID:3954976

The effects of brain lesions on the "hopping reaction" in newborn and adult rabbits: a model for studying age dependent recovery.

PubMed

van Hof, M W; Hobbelen, J F; Gramsbergen, A

1990-01-01

In 5 groups of rabbits (0-1, 2-3, 4-5, 6-7 and 12-13 weeks old) the left frontal, parieto-temporal and occipital cortex were removed. Beginning two weeks after the operations the hopping reaction was tested during 15 weeks. It was found in the groups operated 0-1, 2-3 and 4-5 weeks after birth, that the hopping reaction developed normally. This was not the case in the animals operated 6-7 and 12-13 weeks after birth. Brightness descrimination with the left and right eye was tested in the same animals, beginning 12 weeks after the operation. Contrary to the motor system, no age-development recovery was found in the visual system. In all age groups, brightness discrimination with the eye contralateral to the lesion was impaired.

Characteristics of choroidal neovascularization in the complications of age-related macular degeneration prevention trial.

PubMed

Maguire, Maureen G; Alexander, Judith; Fine, Stuart L

2008-09-01

To describe the characteristics of incident choroidal neovascularization (CNV) in observed and treated eyes in the Complications of Age-related Macular Degeneration Prevention Trial (CAPT). Cross-sectional descriptive study within a multicenter, randomized clinical trial. Patients who developed CNV during CAPT follow-up. Inclusion criteria for CAPT specified bilateral large drusen (>or=10 drusen at least 125 micro), visual acuity >or=20/40 in each eye, and age >or=50. Exclusion criteria included CNV and geographic atrophy >1 Macular Photocoagulation Study (MPS) disc area or within 500 micro of the foveal center. One eye of each person was selected randomly for low-intensity laser treatment and the contralateral eye was observed. Fluorescein angiography was performed at baseline, annually for >or=5 years, and whenever there were symptoms of CNV. Trained readers at the CAPT Photograph Reading Center assessed color stereo photographs and angiogram negatives to identify CNV. Choroidal neovascularization was classified by type (predominantly classic CNV, minimally classic CNV, occult only CNV, or scar), location, and area. Visual acuity was measured by certified examiners. Symmetry of characteristics between eyes of bilaterally affected patients was examined. Choroidal neovascularization developed in 282 eyes of 225 patients. At the time of detection, 192 (68%) of the lesions were occult only, 153 (54%) were subfoveal, and 157 (56%) were or=20/40 in 123 (69%) of 179 eyes with visual acuity measured at the time of detection. Choroidal neovascularization developed in both eyes in 57 patients (25%) during CAPT follow-up. Lesions in eyes of bilaterally affected patients were no more similar to each other than affected eyes in 2 different patients. When patients are monitored closely, many CNV lesions can be detected outside of the fovea and when they are relatively small. Early detection may lead to improved long-term visual acuity.

In vivo study of the biocompatibility of a novel compressed collagen hydrogel scaffold for artificial corneas.

PubMed

Xiao, Xianghua; Pan, Shiyin; Liu, Xianning; Zhu, Xiuping; Connon, Che John; Wu, Jie; Mi, Shengli

2014-06-01

The experiments were designed to evaluate the biocompatibility of a plastically compressed collagen scaffold (PCCS). The ultrastructure of the PCCS was observed via scanning electron microscopy. Twenty New Zealand white rabbits were randomly divided into experimental and control groups that received corneal pocket transplantation with PCCS and an amniotic membrane, respectively. And the contralateral eye of the implanted rabbit served as the normal group. On the 1st, 7th, 14th, 21st, 30th, 60th, 90th, and 120th postoperative day, the eyes were observed via a slit lamp. On the 120th postoperative day, the rabbit eyes were enucleated to examine the tissue compatibility of the implanted stroma. The PCCS was white and translucent. The scanning electron microscopy results showed that fibers within the PCCS were densely packed and evenly arranged. No edema, inflammation, or neovascularization was observed on ocular surface under a slit lamp and few lymphocytes were observed in the stroma of rabbit cornea after histological study. In conclusion, the PCCS has extremely high biocompatibility and is a promising corneal scaffold for an artificial cornea. Copyright © 2013 Society of Plastics Engineers.

Application of TrackEye in equine locomotion research.

PubMed

Drevemo, S; Roepstorff, L; Kallings, P; Johnston, C J

1993-01-01

TrackEye is an analysis system, which is applicable for equine biokinematic studies. It covers the whole process from digitizing of images, automatic target tracking and analysis. Key components in the system are an image work station for processing of video images and a high-resolution film-to-video scanner for 16-mm film. A recording module controls the input device and handles the capture of image sequences into a videodisc system, and a tracking module is able to follow reference markers automatically. The system offers a flexible analysis including calculations of markers displacements, distances and joint angles, velocities and accelerations. TrackEye was used to study effects of phenylbutazone on the fetlock and carpal joint angle movements in a horse with a mild lameness caused by osteo-arthritis in the fetlock joint of a forelimb. Significant differences, most evident before treatment, were observed in the minimum fetlock and carpal joint angles when contralateral limbs were compared (p < 0.001). The minimum fetlock angle and the minimum carpal joint angle were significantly greater in the lame limb before treatment compared to those 6, 37 and 49 h after the last treatment (p < 0.001).

A Controlled, Randomized Double-Blind Study to Evaluate the Safety and Efficacy of Chitosan-N-Acetylcysteine for the Treatment of Dry Eye Syndrome.

PubMed

Schmidl, Doreen; Werkmeister, René; Kaya, Semira; Unterhuber, Angelika; Witkowska, Katarzyna J; Baumgartner, Renate; Höller, Sonja; O'Rourke, Maria; Peterson, Ward; Wolter, Annika; Prinz, Martin; Schmetterer, Leopold; Garhöfer, Gerhard

2017-06-01

This study was designed to evaluate the effect of chitosan-N-acetylcysteine (C-NAC) eye drops on tear film thickness (TFT) in patients with dry eye syndrome (DES). This was a controlled, randomized, double-blind clinical investigation with patients assigned to 2 cohorts. In Cohort I, 21 patients were randomized to receive 1 instillation of C-NAC eye drops in 1 eye and placebo (normal saline solution) in the contralateral eye. In Cohort II, 17 patients were randomized to receive C-NAC eye drops once (QD) or twice (BID) daily for 5 days. TFT was assessed with a custom-built ultrahigh-resolution optical coherence tomography system. In Cohort I, mean TFT increased from 3.9 ± 0.5 μm predose to 4.8 ± 1.1 μm 10 min postdose after treatment with C-NAC. The increase was significantly different from placebo over time (P < 0.0001) and remained stable until 24 h postdose. In Cohort II, TFT increased with QD and BID instillation, with no significant difference between regimens. In both groups, Ocular Surface Disease Index scores improved, fewer patients presented with corneal damage, and symptoms of ocular discomfort/conjunctival redness were reduced. A single instillation of C-NAC significantly increased mean TFT in patients with DES as early as 10 min after instillation and lasted for 24 h. The magnitude of the increase in TFT following a single instillation was comparable with that after instillation twice daily over 5 days. Corneal damage improved in >60% of patients. C-NAC could be a viable treatment option for DES.

Changes in color vision and contrast sensitivity after descemet membrane endothelial keratoplasty for fuchs endothelial dystrophy.

PubMed

Cabrerizo, Javier; Livny, Eitan; Musa, Fayyaz U; Leeuwenburgh, Paulien; van Dijk, Korine; Melles, Gerrit R J

2014-10-01

The aim of this study is to evaluate contrast sensitivity, color vision, and subjective patient satisfaction after Descemet membrane endothelial keratoplasty (DMEK) in patients with bilateral Fuchs endothelial dystrophy (FED). From a group of 500 DMEK surgeries performed in our center, patients with a history of bilateral FED and unilateral DMEK were identified. A total of 29 patients were included in the study and divided into 2 groups: phakic (n = 12) and pseudophakic unilateral DMEK (n = 17) and their contralateral, untreated FED-affected eye. In addition, a control group of 10 healthy eyes of 10 patients was included. Pelli-Robson contrast sensitivity and Farnsworth-Munsell 100 hue color vision tests were performed. Subjective optical quality was graded with a questionnaire. Compared with untreated FED-affected eyes, best spectacle-corrected visual acuity was higher after DMEK in phakic and pseudophakic eyes (P = 0.030 and P < 0.001, respectively); a similar result was obtained for contrast sensitivity (P < 0.001 and P < 0.001, respectively). Color vision did not differ between untreated FED-affected and DMEK-operated eyes in the phakic group (P = 0.802) and the pseudophakic group (P = 0.227). Subjective optical quality was better in DMEK-operated eyes than in untreated FED-affected eyes in the phakic group (P < 0.001) and in the pseudophakic group (P < 0.001). In FED, DMEK may not only be effective for obtaining a higher visual acuity but particularly improving the contrast sensitivity may also lead to better subjective optical performance. Although frequently mentioned spontaneously by patients, an objective change in color vision could not be substantiated. Hence, quantifying contrast sensitivity before surgery may aid in the decision for surgery, and in the evaluation of surgical outcome.

Visual Results Following Implantation of a Refractive Multifocal Intraocular Lens in One Eye and a Diffractive in the Contralateral Eye

PubMed Central

Yıldırım Karabağ, Revan; Günenç, Üzeyir; Aydın, Rukiye; Arıkan, Gül; Aslankara, Hüseyin

2018-01-01

Objectives To assess the visual outcomes in patients who underwent cataract surgery with multifocal intraocular lens (IOL) implantation using a “mix and match” approach. Materials and Methods Twenty patients (40 eyes) were involved in this prospective, nonrandomized study. Refractive multifocal IOLs (ReZoom NXG1) were implanted in patients’ dominant eyes and diffractive multifocal IOLs (Tecnis ZMA00) were implanted in their non-dominant eyes. Monocular and binocular uncorrected distance, intermediate and near visual acuity (logMAR), and contrast sensitivity levels were measured at 1, 3, and 6 months after cataract surgery. Defocus curves, reading speeds, patient satisfaction, spectacle dependence, and halo and glare symptoms were also evaluated at 6 months after the surgery. Postoperative quality of life was assessed with the Turkish version of National Eye Institute Visual Function Questionnaire-25. Results The study group comprised 8 females and 12 males with a mean age of 69.45±10.76 years (range, 31-86 years). The uncorrected distance and intermediate visual acuity levels were significantly better in the ReZoom-implanted eyes at postoperative 6 months (p=0.026 and p=0.037, respectively). There was no statistically significant difference in uncorrected near visual acuity (p>0.05). There was no statistically significant difference in contrast sensitivity, reading speed, halos, or glare between the groups (p<0.05). Mild glare/halo was reported by 40% of the subjects. The mean patient satisfaction was 95% and all patients were spectacle independent. Conclusion Mixing and matching multifocal IOLs in selected cataract patients provides excellent visual outcome, a high level of patient satisfaction, and spectacle independency. PMID:29576891

Intravitreal Autologous Bone Marrow CD34+ Cell Therapy for Ischemic and Degenerative Retinal Disorders: Preliminary Phase 1 Clinical Trial Findings

PubMed Central

Park, Susanna S.; Bauer, Gerhard; Abedi, Mehrdad; Pontow, Suzanne; Panorgias, Athanasios; Jonnal, Ravi; Zawadzki, Robert J.; Werner, John S.; Nolta, Jan

2015-01-01

Purpose. Because human bone marrow (BM) CD34+ stem cells home into damaged tissue and may play an important role in tissue repair, this pilot clinical trial explored the safety and feasibility of intravitreal autologous CD34+ BM cells as potential therapy for ischemic or degenerative retinal conditions. Methods. This prospective study enrolled six subjects (six eyes) with irreversible vision loss from retinal vascular occlusion, hereditary or nonexudative age-related macular degeneration, or retinitis pigmentosa. CD34+ cells were isolated under Good Manufacturing Practice conditions from the mononuclear cellular fraction of the BM aspirate using a CliniMACs magnetic cell sorter. After intravitreal CD34+ cell injection, serial ophthalmic examinations, microperimetry/perimetry, fluorescein angiography, electroretinography (ERG), optical coherence tomography (OCT), and adaptive optics OCT were performed during the 6-month follow-up. Results. A mean of 3.4 million (range, 1–7 million) CD34+ cells were isolated and injected per eye. The therapy was well tolerated with no intraocular inflammation or hyperproliferation. Best-corrected visual acuity and full-field ERG showed no worsening after 6 months. Clinical examination also showed no worsening during follow-up except among age-related macular degeneration subjects in whom mild progression of geographic atrophy was noted in both the study eye and contralateral eye at 6-month follow-up, concurrent with some possible decline on multifocal ERG and microperimetry. Cellular in vivo imaging using adaptive optics OCT showed changes suggestive of new cellular incorporation into the macula of the hereditary macular degeneration study eye. Conclusions. Intravitreal autologous BM CD34+ cell therapy appears feasible and well tolerated in eyes with ischemic or degenerative retinal conditions and merits further exploration. (ClinicalTrials.gov number, NCT01736059.) PMID:25491299

Diagnostic features of feline restrictive orbital myofibroblastic sarcoma.

PubMed

Bell, C M; Schwarz, T; Dubielzig, R R

2011-05-01

A progressive debilitating disease of the orbit and adjacent connective tissues of cats has historically been called feline orbital pseudotumor. The authors reviewed clinical, histopathologic, and diagnostic imaging features of this disease in 12 cases from the Comparative Ocular Pathology Laboratory of Wisconsin. The cats' ages ranged from 7 to 16 years (mean, 10.8 years). All cats had a history of severely restricted mobility of the globe and eyelids with secondary corneal disease. Eleven cats (92%) had concurrent involvement of the contralateral eye and/or the oral cavity. Diffuse scleral or episcleral thickening was seen with computed tomography in all clinically affected eyes. Histologically, an insidious infiltration of neoplastic spindle cells in the orbit, eyelids, and periorbital skin and soft tissues, with collagen deposition and a few perivascular lymphocytes, led to entrapment and restricted mobility of the eyelids and orbital tissues. The tumor failed to form a discrete mass, and it spread along fascial planes to the contralateral orbit and eyelids and/or the lips and oral cavity. In all tested cases (n = 10), neoplastic cells were immunohistochemically positive for vimentin, S100 protein, and smooth muscle actin. The authors adopted the term feline restrictive orbital myofibroblastic sarcoma to reflect the restricted mobility of the eyelids and globe and the imaging and histologic features of an invasive yet low-grade myofibroblastic sarcoma.

Radiation treatment inhibits monocyte entry into the optic nerve head and prevents neuronal damage in a mouse model of glaucoma

PubMed Central

Howell, Gareth R.; Soto, Ileana; Zhu, Xianjun; Ryan, Margaret; Macalinao, Danilo G.; Sousa, Gregory L.; Caddle, Lura B.; MacNicoll, Katharine H.; Barbay, Jessica M.; Porciatti, Vittorio; Anderson, Michael G.; Smith, Richard S.; Clark, Abbot F.; Libby, Richard T.; John, Simon W.M.

2012-01-01

Glaucoma is a common ocular disorder that is a leading cause of blindness worldwide. It is characterized by the dysfunction and loss of retinal ganglion cells (RGCs). Although many studies have implicated various molecules in glaucoma, no mechanism has been shown to be responsible for the earliest detectable damage to RGCs and their axons in the optic nerve. Here, we show that the leukocyte transendothelial migration pathway is activated in the optic nerve head at the earliest stages of disease in an inherited mouse model of glaucoma. This resulted in proinflammatory monocytes entering the optic nerve prior to detectable neuronal damage. A 1-time x-ray treatment prevented monocyte entry and subsequent glaucomatous damage. A single x-ray treatment of an individual eye in young mice provided that eye with long-term protection from glaucoma but had no effect on the contralateral eye. Localized radiation treatment prevented detectable neuronal damage and dysfunction in treated eyes, despite the continued presence of other glaucomatous stresses and signaling pathways. Injection of endothelin-2, a damaging mediator produced by the monocytes, into irradiated eyes, combined with the other glaucomatous stresses, restored neural damage with a topography characteristic of glaucoma. Together, these data support a model of glaucomatous damage involving monocyte entry into the optic nerve. PMID:22426214

Spatial updating in human parietal cortex

NASA Technical Reports Server (NTRS)

Merriam, Elisha P.; Genovese, Christopher R.; Colby, Carol L.

2003-01-01

Single neurons in monkey parietal cortex update visual information in conjunction with eye movements. This remapping of stimulus representations is thought to contribute to spatial constancy. We hypothesized that a similar process occurs in human parietal cortex and that we could visualize it with functional MRI. We scanned subjects during a task that involved remapping of visual signals across hemifields. We observed an initial response in the hemisphere contralateral to the visual stimulus, followed by a remapped response in the hemisphere ipsilateral to the stimulus. We ruled out the possibility that this remapped response resulted from either eye movements or visual stimuli alone. Our results demonstrate that updating of visual information occurs in human parietal cortex.

Comparing aspheric ablation profile with standard corneal ablation for correction of myopia and myopic astigmatism, a contralateral eye study.

PubMed

Ghoreishi, Mohammad; Naderi Beni, Afsaneh; Naderi Beni, Zahra; Zandi, Alireza; Kianersi, Farzan

2017-12-01

The purpose of this study is to compare visual outcomes of myopic refractive surgery, using tissue saving (TS), a standard ablation profile by a Technolas 217z100, and aberration smart ablation (ASA), an aspheric algorithm by a MEL 80 excimer laser in two eyes of one patient. In this prospective interventional paired-eye controlled study, a total of 100 eyes of 50 participants with myopia with or without astigmatism underwent thin-flap Femto-LASIK, using a Femto LDV femtosecond laser (Ziemer Ophthalmic Systems AG, Port, Switzerland). For each patient, one eye was randomly treated with tissue-saving algorithm (TS group) by the Technolas 217z100 excimer laser and the other eye was treated with optimized smart ablation profile (ASA group) by the MEL 80 excimer laser. Outcome measures were uncorrected distance visual acuities (UDVAs), corrected distance visual acuities (CDVAs), manifest refraction, higher-order aberrations (HOAs), contrast sensitivity, and patient satisfaction 12 months after surgery. At 12 months postoperative, "45 subjects returned with mean" UDVA was - 0.02 ± 0.08 Logarithm of mean angle of resolution (LogMAR) for TS group and - 0.02 ± 0.09 LogMAR for ASA group (P = 0.91). Of the TS eyes, 42/45 (93.3%) and 32/45 (71.1%) were within ± 0.5 D and ± 0.25 D of target refraction, respectively, and of the ASA eyes, 41/45 (91.1%) and 30/45 (66.6%) were within ± 0.5 D and ± 0.25 D of target refraction, respectively. No statistically significant differences were observed between groups in HOAs changes and contrast sensitivity function. Aspheric and non-aspheric LASIKs using the two different excimer lasers provide similar results in myopic and myopic astigmatism patients.

Callosal Influence on Visual Receptive Fields Has an Ocular, an Orientation-and Direction Bias.

PubMed

Conde-Ocazionez, Sergio A; Jungen, Christiane; Wunderle, Thomas; Eriksson, David; Neuenschwander, Sergio; Schmidt, Kerstin E

2018-01-01

One leading hypothesis on the nature of visual callosal connections (CC) is that they replicate features of intrahemispheric lateral connections. However, CC act also in the central part of the binocular visual field. In agreement, early experiments in cats indicated that they provide the ipsilateral eye part of binocular receptive fields (RFs) at the vertical midline (Berlucchi and Rizzolatti, 1968), and play a key role in stereoscopic function. But until today callosal inputs to receptive fields activated by one or both eyes were never compared simultaneously, because callosal function has been often studied by cutting or lesioning either corpus callosum or optic chiasm not allowing such a comparison. To investigate the functional contribution of CC in the intact cat visual system we recorded both monocular and binocular neuronal spiking responses and receptive fields in the 17/18 transition zone during reversible deactivation of the contralateral hemisphere. Unexpectedly from many of the previous reports, we observe no change in ocular dominance during CC deactivation. Throughout the transition zone, a majority of RFs shrink, but several also increase in size. RFs are significantly more affected for ipsi- as opposed to contralateral stimulation, but changes are also observed with binocular stimulation. Noteworthy, RF shrinkages are tiny and not correlated to the profound decreases of monocular and binocular firing rates. They depend more on orientation and direction preference than on eccentricity or ocular dominance of the receiving neuron's RF. Our findings confirm that in binocularly viewing mammals, binocular RFs near the midline are constructed via the direct geniculo-cortical pathway. They also support the idea that input from the two eyes complement each other through CC: Rather than linking parts of RFs separated by the vertical meridian, CC convey a modulatory influence, reflecting the feature selectivity of lateral circuits, with a strong cardinal bias.

Visual field defects of the contralateral eye of non-arteritic ischemic anterior optic neuropathy: are they related to sleep apnea?

PubMed

Aptel, Florent; Aryal-Charles, Nischal; Tamisier, Renaud; Pépin, Jean-Louis; Lesoin, Antoine; Chiquet, Christophe

2017-06-01

To evaluate whether obstructive sleep apnea (OSA) is responsible for the visual field defects found in the fellow eyes of patients with non-arteritic ischemic optic neuropathy (NAION). Prospective cross-sectional study. The visual fields of the fellow eyes of NAION subjects with OSA were compared to the visual fields of control OSA patients matched for OSA severity. All patients underwent comprehensive ophthalmological and general examination including Humphrey 24.2 SITA-Standard visual field and polysomnography. Visual field defects were classified according the Ischemic Optic Neuropathy Decompression Trial (IONDT) classification. From a cohort of 78 consecutive subjects with NAION, 34 unaffected fellow eyes were compared to 34 control eyes of subjects matched for OSA severity (apnea-hypopnea index [AHI] 35.5 ± 11.6 vs 35.4 ± 9.4 events per hour, respectively, p = 0.63). After adjustment for age and body mass index, all visual field parameters were significantly different between the NAION fellow eyes and those of the control OSA groups, including mean deviation (-4.5 ± 3.7 vs -1.3 ± 1.8 dB, respectively, p < 0.05), visual field index (91.6 ± 10 vs 97.4 ± 3.5%, respectively, p = 0.002), pattern standard deviation (3.7 ± 2.3 vs 2.5 ± 2 dB, respectively, p = 0.015), and number of subjects with at least one defect on the IONDT classification (20 vs 10, respectively, p < 0.05). OSA alone does not explain the visual field defects frequently found in the fellow eyes of NAION patients.

Retinal projections in the short-tailed fruit bat, Carollia perspicillata, as studied using the axonal transport of cholera toxin B subunit: Comparison with mouse.

PubMed

Scalia, Frank; Rasweiler, John J; Danias, John

2015-08-15

To provide a modern description of the Chiropteran visual system, the subcortical retinal projections were studied in the short-tailed fruit bat, Carollia perspicillata, using the anterograde transport of eye-injected cholera toxin B subunit, supplemented by the silver-impregnation of anterograde degeneration following eye removal, and compared with the retinal projections of the mouse. The retinal projections were heavily labeled by the transported toxin in both species. Almost all components of the murine retinal projection are present in Carollia in varying degrees of prominence and laterality. The projections: to the superior colliculus, accessory optic nuclei, and nucleus of the optic tract are predominantly or exclusively contralateral; to the dorsal lateral geniculate nucleus and posterior pretectal nucleus are predominantly contralateral; to the ventral lateral geniculate nucleus, intergeniculate leaflet, and olivary pretectal nucleus have a substantial ipsilateral component; and to the suprachiasmatic nucleus are symmetrically bilateral. The retinal projection in Carollia is surprisingly reduced at the anterior end of the dorsal lateral geniculate and superior colliculus, suggestive of a paucity of the relevant ganglion cells in the ventrotemporal retina. In the superior colliculus, in which the superficial gray layer is very thin, the projection is patchy in places where the layer is locally absent. Except for a posteriorly located lateral terminal nucleus, the other accessory optic nuclei are diminutive in Carollia, as is the nucleus of the optic tract. In both species the cholera toxin labeled sparse groups of apparently terminating axons in numerous regions not listed above. A question of their significance is discussed. © 2015 Wiley Periodicals, Inc.

Sodium Orthovanadate Effect on Outflow Facility and Intraocular Pressure in Live Monkeys

PubMed Central

Tan, James C.H.; Kiland, Julie A.; Gonzalez, Jose M.; Gabelt, B’Ann T.; Peters, Donna M.; Kaufman, Paul L.

2010-01-01

Sodium orthovanadate (Na3VO4) is reported to reduce IOP by affecting aqueous formation, but whether it also affects outflow facility (OF) is unclear. We tested the effect of Na3VO4 on OF and intraocular pressure (IOP) in live cynomolgus monkeys, and on actin and cell adhesion organization in cultured human trabecular meshwork (HTM) cells. Total OF (n = 12) was measured by 2-level constant pressure perfusion of the monkey anterior chamber (AC) before and after exchange with 1 mM Na3VO4 or vehicle in opposite eyes. Topical 1% Na3VO4 or vehicle only was given twice daily (each 2×20 μL drops) for 4 days to opposite eyes (n = 8), and Goldmann IOP was measured before and hourly after treatment for 6 hours on Days 1 and 4. Filamentous actin and vinculin-containing cell adhesions were examined by epifluorescence microscopy after the cells had been incubated with 1 mM Na3VO4 for 24 hours. A) In monkeys, Na3VO4 increased OF by 29.3 ± 8.8% (mean ± s.e.m.) over the perfusion interval when adjusted for baseline and contralateral eye washout (p = 0.01; n = 12). B) Day 1 baseline IOP was 16.2 ± 1.5 mmHg in treated eyes and 15.9 ± 1.3 mmHg in the contralateral control eyes. Following treatment on Day 1, IOP was no different (p>0.05) between treated eyes and control eyes at any time-point or compared to baseline. Day 4 mean IOP averaged over hours 2–6 was 13.5 ± 0.8 mmHg in treated eyes and 16.1 ± 0.2 mmHg in control eyes. Treated eye IOP was lower than its Day 4 baseline (p<0.005), lower than control eyes for the same Day 4 interval (p = 0.009), and lower than the Day 1 baseline (p = 0.0000). Control eye IOP on Day 4 was not significantly different from baseline on Day 1. C) Incubation of HTM cells with 1 mM Na3VO4 for 24 hours caused a loss of actin stress fibers and vinculin-containing adhesions. Cell retraction and separation was also observed in vanadate-treated cultures. Reformation of actin stress fibers, vinculin-containing adhesions and confluent monolayers occurred within 24 hours after Na3VO4-containing culture medium was replaced with Na3VO4-free medium. Ocular administration of Na3VO4 to live monkeys significantly increases OF and reduces IOP. Na3VO4 reversibly disrupts actin and cell adhesion organization and causes retraction and separation of cultured HTM cells. Na3VO4 increases pressure-dependent outflow in live monkeys. Altered actin architecture in the TM may play a part in this increased OF. PMID:20620138

Incidence of Fellow Eye Involvement in Patients With Unilateral Exudative Age-Related Macular Degeneration.

PubMed

Yanagi, Yasuo; Mohla, Aditi; Lee, Shu Yen; Mathur, Ranjana; Chan, Choi Mun; Yeo, Ian; Wong, Tien Yin; Cheung, Chui Ming Gemmy

2018-06-07

Since the advent of optical coherence tomography angiography (OCT-A), nonexudative neovascularization has been described in the fellow eyes of unilateral exudative age-related macular degeneration (AMD). However, there is limited literature describing the natural course and optimal management of these lesions. To determine the incidence of fellow eye involvement in patients presenting with unilateral typical AMD or polypoidal choroidal vasculopathy and to evaluate the patterns of OCT-A changes within 6 months before the onset of exudative changes, especially focusing on nonexudative neovascularization. Data for this study were taken from a prospective, observational cohort study involving Asian patients with exudative AMD in the Asian AMD Phenotyping Study between October 2015 and March 2016. Analyses began in June 2017. Only patients who had gradable OCT-A and indocyanine green angiography (ICGA) scans of the fellow eye at baseline and follow-up at least 6 months apart were included for the analysis. The contralateral eye was evaluated for presence of nonexudative neovascularization based on multimodal imaging, which included ICGA, spectral domain optical coherence tomography, and OCT-A. The difference between the incidence of those with nonexudative choroidal neovascularization and those without as analyzed using log-rank test and qualitative analysis of OCT-A images. We included 95 fellow eyes of 95 patients who presented with unilateral exudative AMD with a mean (SD) age of 68.6 (8.6) years. Nonexudative neovascularization was present in 18 eyes (19%) (8 [22.9%] and 10 [19.0%] fellow eyes with typical AMD and polypoidal choroidal vasculopathy, respectively; 8 [44.4%] on OCT-A; 5 [27.8%] on ICGA; and 5 [27.8%] on both OCT-A and ICGA). Development of exudative changes was noted in 6 fellow eyes (6.3%). Four eyes developed exudation from previously noted nonexudative neovascularization, and 2 eyes arose exudative changes from de novo. The probability of developing exudation within 6 months was significantly higher in eyes with baseline nonexudative neovascularization (0.087; 95% CI, 0.0033-0.210) compared with eyes without (0.010; 95% CI, 0.0026-0.041) (P = .008). In all eyes whose OCT-A images were available immediately before the onset of exudative changes, there was an increase in the size of network vessels compared with baseline. The presence of nonexudative neovascularization may predispose to the development of exudative changes.

Nucleus prepositus hypoglossi lesions produce a unique ocular motor syndrome

PubMed Central

Kim, Sung-Hee; Zee, David S.; du Lac, Sascha; Kim, Hyo Jung

2016-01-01

Objective: To describe the ocular motor abnormalities in 9 patients with a lesion involving the nucleus prepositus hypoglossi (NPH), a key constituent of a vestibular-cerebellar-brainstem neural network that ensures that the eyes are held steady in all positions of gaze. Methods: We recorded eye movements, including the vestibulo-ocular reflex during head impulses, in patients with vertigo and a lesion involving the NPH. Results: Our patients showed an ipsilesional-beating spontaneous nystagmus, horizontal gaze-evoked nystagmus more intense on looking toward the ipsilesional side, impaired pursuit more to the ipsilesional side, central patterns of head-shaking nystagmus, contralateral eye deviation, and decreased vestibulo-ocular reflex gain during contralesionally directed head impulses. Conclusions: We attribute these findings to an imbalance in the NPH–inferior olive–flocculus–vestibular nucleus loop, and the ocular motor abnormalities provide a new brainstem localization for patients with acute vertigo. PMID:27733568

Effect of Orbital Decompression on Corneal Topography in Patients with Thyroid Ophthalmopathy

PubMed Central

Kim, Su Ah; Jung, Su Kyung; Paik, Ji Sun; Yang, Suk-Woo

2015-01-01

Objective To evaluate changes in corneal astigmatism in patients undergoing orbital decompression surgery. Methods This retrospective, non randomized comparative study involved 42 eyes from 21 patients with thyroid ophthalmopathy who underwent orbital decompression surgery between September 2011 and September 2014. The 42 eyes were divided into three groups: control (9 eyes), two-wall decompression (25 eyes), and three-wall decompression (8 eyes). The control group was defined as the contralateral eyes of nine patients who underwent orbital decompression surgery in only one eye. Corneal topography (Orbscan II), Hertel exophthalmometry, and intraocular pressure were measured at 1 month before and 3 months after surgery. Corneal topographic parameters analyzed were total astigmatism (TA), steepest axis (SA), central corneal thickness (CCT), and anterior chamber depth (ACD). Results Exophthalmometry values and intraocular pressure decreased significantly after the decompression surgery. The change (absolute value (|x|) of the difference) in astigmatism at the 3 mm zone was significantly different between the decompression group and the controls (p = 0.025). There was also a significant change in the steepest axis at the 3 mm zone between the decompression group and the controls (p = 0.033). An analysis of relevant changes in astigmatism showed that there was a dominant tendency for incyclotorsion of the steepest axis in eyes that underwent decompression surgery. Using Astig PLOT, the mean surgically induced astigmatism (SIA) was 0.21±0.88 D with an axis of 46±22°, suggesting that decompression surgery did change the corneal shape and induced incyclotorsion of the steepest axis. Conclusions There was a significant change in corneal astigmatism after orbital decompression surgery and this change was sufficient to affect the optical function of the cornea. Surgeons and patients should be aware of these changes. PMID:26352432

Effect of moderate intraocular pressure changes on topographic measurements with confocal scanning laser tomography in patients with glaucoma.

PubMed

Nicolela, Marcelo T; Soares, Adael S; Carrillo, Monica M; Chauhan, Balwantray C; LeBlanc, Raymond P; Artes, Paul H

2006-05-01

To evaluate optic disc topography changes after intraocular pressure (IOP) modulation in patients with glaucoma. Twenty-three patients with glaucoma were studied. Three mean optic disc topography images were obtained with the Heidelberg Retina Tomograph II at baseline and weeks 1, 2, 4, and 8 (visits 1, 2, 3, 4, and 5, respectively). Topical medications were discontinued in the study eye after visit 1 and resumed after visit 4 but maintained in the contralateral control eye. Central corneal thickness was measured at the last visit. Topographic changes were determined by stereometric parameters (rim area and mean cup depth) and at discrete topographic locations using the Topographic Change Analysis program (from the Heidelberg Retina Tomograph II). In the study eyes, IOP increased significantly (5.4 mm Hg at visit 4; P<.001) after withdrawal of topical medications but returned to baseline levels after resuming medications; no statistically significant topographic changes, however, were observed. Moreover, no relationship between change in IOP and stereometric parameters was observed. Central corneal thickness was not associated with changes in optic disc topography induced by IOP modulation. In patients with glaucoma, significant but relatively moderate IOP increases and decreases on the order of 5 mm Hg did not appear to have an effect on optic disc topography.

Cortical sources of ERP in prosaccade and antisaccade eye movements using realistic source models

PubMed Central

Richards, John E.

2013-01-01

The cortical sources of event-related-potentials (ERP) using realistic source models were examined in a prosaccade and antisaccade procedure. College-age participants were presented with a preparatory interval and a target that indicated the direction of the eye movement that was to be made. In some blocks a cue was given in the peripheral location where the target was to be presented and in other blocks no cue was given. In Experiment 1 the prosaccade and antisaccade trials were presented randomly within a block; in Experiment 2 procedures were compared in which either prosaccade and antisaccade trials were mixed in the same block, or trials were presented in separate blocks with only one type of eye movement. There was a central negative slow wave occurring prior to the target, a slow positive wave over the parietal scalp prior to the saccade, and a parietal spike potential immediately prior to saccade onset. Cortical source analysis of these ERP components showed a common set of sources in the ventral anterior cingulate and orbital frontal gyrus for the presaccadic positive slow wave and the spike potential. In Experiment 2 the same cued- and non-cued blocks were used, but prosaccade and antisaccade trials were presented in separate blocks. This resulted in a smaller difference in reaction time between prosaccade and antisaccade trials. Unlike the first experiment, the central negative slow wave was larger on antisaccade than on prosaccade trials, and this effect on the ERP component had its cortical source primarily in the parietal and mid-central cortical areas contralateral to the direction of the eye movement. These results suggest that blocked prosaccade and antisaccade trials results in preparatory or set effects that decreases reaction time, eliminates some cueing effects, and is based on contralateral parietal-central brain areas. PMID:23847476

Retrobulbar ocular blood flow changes measured by colour Doppler imaging after intra-arterial chemotherapy in retinoblastoma.

PubMed

Xue, Kang; Liu, Ailin; Hui, Ren; Zhang, Jing; Qian, Jiang

2017-10-01

To evaluate the effects of intra-arterial chemotherapy on retrobulbar blood flow parameters in patients with retinoblastoma. 20 eyes of 10 patients with unilateral retinoblastoma that were treated with intra-arterial chemotherapy were evaluated using colour Doppler imaging. The peak systolic and end-diastolic velocities of the ophthalmic, central retinal and posterior ciliary arteries were determined. The pulsatility and resistance indices were calculated automatically. The treated eye was compared with the untreated (control) eye and with itself before and after intra-arterial chemotherapy. When comparing the retinoblastoma-containing eyes with the contralateral normal eyes, the peak systolic and end-diastolic velocities of the central retinal artery were significantly higher in the tumorous eyes than in the normal eyes before intra-arterial chemotherapy. Moreover, the peak systolic and end-diastolic velocities in the posterior ciliary and central retinal arteries were significantly decreased after intra-arterial chemotherapy in the tumorous eyes (p<0.05). There were no statistically significant differences in the other parameters. Our results suggest that intra-arterial chemotherapy has a measurable effect on the retrobulbar blood flow, which can cause a decrease in the peak systolic and end-diastolic velocities in the posterior ciliary and central retinal arteries. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Comparative evaluation of Comfilcon A and Senofilcon A bandage contact lenses after transepithelial photorefractive keratectomy

PubMed Central

Mukherjee, Achyut; Ioannides, Antonis; Aslanides, Ioannis

2014-01-01

Purpose To evaluate and compare Comfilcon A and Senofilcon A silicone hydrogel contact lenses used as a therapeutic bandage following transepithelial excimer laser photorefractive keratectomy (PRK). Methods Patients undergoing transepithelial PRK for myopia were prospectively recruited. Included patients had a Comfilcon A silicone hydrogel lens inserted in one eye, with a Senofilcon A lens in the contralateral eye. Postoperative assessment of subjective pain, epithelial healing and visual recovery was at day 1, 3 and 7. Contact lens factors including centration, movement and deposits were assessed. Results 48 eyes of 24 patients were included in the study. Mean age was 31 years (SD 11) and mean refractive error −4.5 D (SD 1.8). Mean pain score at day 1 was significantly higher in the Comfilcon group at 4.6 (SD 2.7) vs. 1.5 (SD2.5) in the Senofilcon group (P < 0.005). Mean time to healing was 3.17 days (SD 0.37) in the Comfilcon group, and 3.21 days (SD 0.4) in the Senofilcon group, with no difference in defect size. There was a pronounced central raphe in 1 eye in the Comfilcon group vs. 5 eyes in the Senofilcon group (P = 0.19). Significantly more eyes demonstrated no lens movement in the Senofilcon group (18 vs. 4, P = 0.0001). Conclusion The variation in material characteristics and lens geometry of different silicone hydrogel lenses affects their clinical characteristics in therapeutic roles. Other factors than oxygen permeability may affect pain and epithelial healing, with superior pain relief from the less permeable Senofilcon lens in this study. PMID:25649638

Comparative evaluation of Comfilcon A and Senofilcon A bandage contact lenses after transepithelial photorefractive keratectomy.

PubMed

Mukherjee, Achyut; Ioannides, Antonis; Aslanides, Ioannis

2015-01-01

To evaluate and compare Comfilcon A and Senofilcon A silicone hydrogel contact lenses used as a therapeutic bandage following transepithelial excimer laser photorefractive keratectomy (PRK). Patients undergoing transepithelial PRK for myopia were prospectively recruited. Included patients had a Comfilcon A silicone hydrogel lens inserted in one eye, with a Senofilcon A lens in the contralateral eye. Postoperative assessment of subjective pain, epithelial healing and visual recovery was at day 1, 3 and 7. Contact lens factors including centration, movement and deposits were assessed. 48 eyes of 24 patients were included in the study. Mean age was 31 years (SD 11) and mean refractive error -4.5 D (SD 1.8). Mean pain score at day 1 was significantly higher in the Comfilcon group at 4.6 (SD 2.7) vs. 1.5 (SD2.5) in the Senofilcon group (P<0.005). Mean time to healing was 3.17 days (SD 0.37) in the Comfilcon group, and 3.21 days (SD 0.4) in the Senofilcon group, with no difference in defect size. There was a pronounced central raphe in 1 eye in the Comfilcon group vs. 5 eyes in the Senofilcon group (P=0.19). Significantly more eyes demonstrated no lens movement in the Senofilcon group (18 vs. 4, P=0.0001). The variation in material characteristics and lens geometry of different silicone hydrogel lenses affects their clinical characteristics in therapeutic roles. Other factors than oxygen permeability may affect pain and epithelial healing, with superior pain relief from the less permeable Senofilcon lens in this study. Copyright © 2013 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

Subcortical functional reorganization due to early blindness

PubMed Central

Jiang, Fang; Fine, Ione; Watkins, Kate E.; Bridge, Holly

2015-01-01

Lack of visual input early in life results in occipital cortical responses to auditory and tactile stimuli. However, it remains unclear whether cross-modal plasticity also occurs in subcortical pathways. With the use of functional magnetic resonance imaging, auditory responses were compared across individuals with congenital anophthalmia (absence of eyes), those with early onset (in the first few years of life) blindness, and normally sighted individuals. We find that the superior colliculus, a “visual” subcortical structure, is recruited by the auditory system in congenital and early onset blindness. Additionally, auditory subcortical responses to monaural stimuli were altered as a result of blindness. Specifically, responses in the auditory thalamus were equally strong to contralateral and ipsilateral stimulation in both groups of blind subjects, whereas sighted controls showed stronger responses to contralateral stimulation. These findings suggest that early blindness results in substantial reorganization of subcortical auditory responses. PMID:25673746

Subcortical functional reorganization due to early blindness.

PubMed

Coullon, Gaelle S L; Jiang, Fang; Fine, Ione; Watkins, Kate E; Bridge, Holly

2015-04-01

Lack of visual input early in life results in occipital cortical responses to auditory and tactile stimuli. However, it remains unclear whether cross-modal plasticity also occurs in subcortical pathways. With the use of functional magnetic resonance imaging, auditory responses were compared across individuals with congenital anophthalmia (absence of eyes), those with early onset (in the first few years of life) blindness, and normally sighted individuals. We find that the superior colliculus, a "visual" subcortical structure, is recruited by the auditory system in congenital and early onset blindness. Additionally, auditory subcortical responses to monaural stimuli were altered as a result of blindness. Specifically, responses in the auditory thalamus were equally strong to contralateral and ipsilateral stimulation in both groups of blind subjects, whereas sighted controls showed stronger responses to contralateral stimulation. These findings suggest that early blindness results in substantial reorganization of subcortical auditory responses. Copyright © 2015 the American Physiological Society.

Disentangling gaze shifts from preparatory ERP effects during spatial attention

PubMed Central

Kennett, Steffan; van Velzen, José; Eimer, Martin; Driver, Jon

2007-01-01

After a cue directing attention to one side, anterior event-related potentials (ERPs) show contralateral negativity (Anterior Directing Attention Negativity, ADAN). It is unclear whether ADAN effects are contaminated by contralateral negativity arising from residual gaze shifts. Conversely, it is possible that ADAN-related potentials contaminate the horizontal electrooculogram (HEOG), via volume conduction. To evaluate these possibilities, we used high-resolution infrared eye tracking, while recording EEG and HEOG in a cued spatial-attention task. We found that, after conventional ERP and HEOG pre-processing exclusions, small but systematic residual gaze shifts in the cued direction can remain, as revealed by the infrared measure. Nevertheless, by using this measure for more stringent exclusion of small gaze shifts, we confirmed that reliable ADAN components remain for preparatory spatial attention in the absence of any systematic gaze shifts toward the cued side. PMID:17241141

Topography and Higher Order Corneal Aberrations of the Fellow Eye in Unilateral Keratoconus.

PubMed

Aksoy, Sibel; Akkaya, Sezen; Özkurt, Yelda; Kurna, Sevda; Açıkalın, Banu; Şengör, Tomris

2017-10-01

Comparison of topography and corneal higher order aberrations (HOA) data of fellow normal eyes of unilateral keratoconus patients with keratoconus eyes and control group. The records of 196 patients with keratoconus were reviewed. Twenty patients were identified as unilateral keratoconus. The best corrected visual acuity (BCVA), topography and aberration data of the unilateral keratoconus patients' normal eyes were compared with their contralateral keratoconus eyes and with control group eyes. For statistical analysis, flat and steep keratometry values, average corneal power, cylindrical power, surface regularity index (SRI), surface asymmetry index (SAI), inferior-superior ratio (I-S), keratoconus prediction index, and elevation-depression power (EDP) and diameter (EDD) topography indices were selected. Mean age of the unilateral keratoconus patients was 26.05±4.73 years and that of the control group was 23.6±8.53 years (p>0.05). There was no statistical difference in BCVA between normal and control eyes (p=0.108), whereas BCVA values were significantly lower in eyes with keratoconus (p=0.001). Comparison of quantitative topographic indices between the groups showed that all indices except the I-S ratio were significantly higher in the normal group than in the control group (p<0.05). The most obvious differences were in the SRI, SAI, EDP, and EDD values. All topographic indices were higher in the keratoconus eyes compared to the normal fellow eyes. There was no difference between normal eyes and the control group in terms of spherical aberration, while coma, trefoil, irregular astigmatism, and total HOA values were higher in the normal eyes of unilateral keratoconus patients (p<0.05). All HOA values were higher in keratoconus eyes than in the control group. According to our study, SRI, SAI, EDP, EDD values, and HOA other than spherical aberration were higher in the clinically and topographically normal fellow eyes of unilateral keratoconus patients when compared to a control group. This finding may be due to the mild asymmetric and morphologic changes in the subclinical stage of keratoconus leading to deterioration in the indicators of corneal irregularity and elevation changes. Therefore, these eyes may be exhibiting the early form of the disease.

Eye, head, and body coordination during large gaze shifts in rhesus monkeys: movement kinematics and the influence of posture.

PubMed

McCluskey, Meaghan K; Cullen, Kathleen E

2007-04-01

Coordinated movements of the eye, head, and body are used to redirect the axis of gaze between objects of interest. However, previous studies of eye-head gaze shifts in head-unrestrained primates generally assumed the contribution of body movement to be negligible. Here we characterized eye-head-body coordination during horizontal gaze shifts made by trained rhesus monkeys to visual targets while they sat upright in a standard primate chair and assumed a more natural sitting posture in a custom-designed chair. In both postures, gaze shifts were characterized by the sequential onset of eye, head, and body movements, which could be described by predictable relationships. Body motion made a small but significant contribution to gaze shifts that were > or =40 degrees in amplitude. Furthermore, as gaze shift amplitude increased (40-120 degrees ), body contribution and velocity increased systematically. In contrast, peak eye and head velocities plateaued at velocities of approximately 250-300 degrees /s, and the rotation of the eye-in-orbit and head-on-body remained well within the physical limits of ocular and neck motility during large gaze shifts, saturating at approximately 35 and 60 degrees , respectively. Gaze shifts initiated with the eye more contralateral in the orbit were accompanied by smaller body as well as head movement amplitudes and velocities were greater when monkeys were seated in the more natural body posture. Taken together, our findings show that body movement makes a predictable contribution to gaze shifts that is systematically influenced by factors such as orbital position and posture. We conclude that body movements are part of a coordinated series of motor events that are used to voluntarily reorient gaze and that these movements can be significant even in a typical laboratory setting. Our results emphasize the need for caution in the interpretation of data from neurophysiological studies of the control of saccadic eye movements and/or eye-head gaze shifts because single neurons can code motor commands to move the body as well as the head and eyes.

BIlateral juxtapapillary retinal capillary haemangioma: Usefulness of aflibercept in the management of its complications.

PubMed

Campos Polo, R; Rubio Sánchez, C; García Guisado, D M; Díaz Luque, M J

2017-10-01

A 45 year-old man with a history of adrenal phaeochromocytoma presented with a subretinal juxtapapillary haemorrhage on his left eye and a small asymptomatic vascular tumour in the contralateral eye. With the mentioned findings, the patient was diagnosed with bilateral retinal capillary haemangioma in the context of a von Hippel Lindau disease. Intravitreal aflibercept was prescribed, with a good outcome of the disease. Many treatments have been proposed for the management of juxtapapillary retinal capillary haemangioma with variable results. Intravitreal aflibercept can be a useful treatment with a good safety profile. Copyright © 2017 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

Substance P and the neurokinin-1 receptor regulate electroencephalogram non-rapid eye movement sleep slow-wave activity locally

PubMed Central

Zielinski, Mark R.; Karpova, Svetlana A.; Yang, Xiaomei; Gerashchenko, Dmitry

2014-01-01

The neuropeptide substance P is an excitatory neurotransmitter produced by various cells including neurons and microglia that is involved in regulating inflammation and cerebral blood flow—functions that affect sleep and slow-wave activity (SWA). Substance P is the major ligand for the neurokinin-1 receptor (NK-1R), which is found throughout the brain including the cortex. The NK-1R is found on sleep-active cortical neurons expressing neuronal nitric oxide synthase whose activity is associated with SWA. We determined the effects of local cortical administration of a NK-1R agonist (substance P-fragment 1, 7) and a NK-1R antagonist (CP96345) on sleep and SWA in mice. The NK-1R agonist significantly enhanced SWA for several hours when applied locally to the cortex of the ipsilateral hemisphere as the electroencephalogram (EEG) electrode but not after application to the contralateral hemisphere when compared to saline vehicle control injections. In addition, a significant compensatory reduction in SWA was found after the NK-1R agonist-induced enhancements in SWA. Conversely, injections of the NK-1R antagonist into the cortex of the ipsilateral hemisphere of the EEG electrode attenuated SWA compared to vehicle injections but this effect was not found after injections of the NK-1R antagonist into contralateral hemisphere as the EEG electrode. Non-rapid eye movement sleep and rapid eye movement sleep duration responses after NK-1R agonist and antagonist injections were not significantly different from the responses to the vehicle. Our findings indicate that the substance P and the NK-1R are involved in regulating SWA locally. PMID:25301750

Measurement of wavefront aberrations and lens deformation in the accommodated eye with optical coherence tomography-equipped wavefront system.

PubMed

He, Ji C; Wang, Jianhua

2014-04-21

To quantitatively approach the relationship between optical changes in an accommodated eye and the geometrical deformation of its crystalline lens, a long scan-depth anterior segment OCT equipped wavefront sensor was developed and integrated with a Badal system. With this system, accommodation was stimulated up to 6.0D in the left eye and also measured in the same eye for three subjects. High correlations between the accommodative responses of refractive power and the radius of the anterior lens surface were found for the three subjects (r>0.98). The change in spherical aberration was also highly correlated with the change in lens thickness (r>0.98). The measurement was very well repeated at a 2nd measurement session on the same day for the three subjects and after two weeks for one subject. The novelty of incorporating the Badal system into the OCT equipped wavefront sensor eliminated axial misalignment of the measurement system with the test eye due to accommodative vergence, as in the contralateral paradigm. The design also allowed the wavefront sensor to capture conjugated sharp Hartmann-Shack images in accommodated eyes to accurately analyze wavefront aberrations. In addition, this design extended the accommodation range up to 10.0D. By using this system, for the first time, we demonstrated linear relationships of the changes between the refractive power and the lens curvature and also between the spherical aberration and the lens thickness during accommodation in vivo. This new system provides an accurate and useful technique to quantitatively study accommodation.

Measurement of wavefront aberrations and lens deformation in the accommodated eye with optical coherence tomography-equipped wavefront system

PubMed Central

He, Ji C.; Wang, Jianhua

2014-01-01

To quantitatively approach the relationship between optical changes in an accommodated eye and the geometrical deformation of its crystalline lens, a long scan-depth anterior segment OCT equipped wavefront sensor was developed and integrated with a Badal system. With this system, accommodation was stimulated up to 6.0D in the left eye and also measured in the same eye for three subjects. High correlations between the accommodative responses of refractive power and the radius of the anterior lens surface were found for the three subjects (r>0.98). The change in spherical aberration was also highly correlated with the change in lens thickness (r>0.98). The measurement was very well repeated at a 2nd measurement session on the same day for the three subjects and after two weeks for one subject. The novelty of incorporating the Badal system into the OCT equipped wavefront sensor eliminated axial misalignment of the measurement system with the test eye due to accommodative vergence, as in the contralateral paradigm. The design also allowed the wavefront sensor to capture conjugated sharp Hartmann-Shack images in accommodated eyes to accurately analyze wavefront aberrations. In addition, this design extended the accommodation range up to 10.0D. By using this system, for the first time, we demonstrated linear relationships of the changes between the refractive power and the lens curvature and also between the spherical aberration and the lens thickness during accommodation in vivo. This new system provides an accurate and useful technique to quantitatively study accommodation. PMID:24787861

Characterization of uveitis induced by use of a single intravitreal injection of bacterial lipopolysaccharide in cats.

PubMed

Del Sole, María J; Sande, Pablo H; Felipe, Antonio E; Fernandez, Diego C; Keller Sarmiento, María I; Aba, Marcelo A; Rosenstein, Ruth E

2008-11-01

To investigate the use of a single intravitreal injection of bacterial lipopolysaccharide (LPS) to experimentally induce uveitis in cats. 7 young male European shorthair cats that were considered physically and ophthalmologically healthy. In each cat, LPS was injected intravitreally into 1 eye; the contralateral eye was injected with the preparation vehicle. During a period of 45 days, both eyes were evaluated by means of clinical evaluation; assessment of the integrity of the blood-aqueous humor barrier (determined via measurement of protein concentration and cell content in samples of aqueous humor); functional analysis (via electroretinography); and following euthanasia, histologic examination of the retinas. In LPS-treated eyes, several clinical signs were observed until day 45 after injection. Compared with vehicle-treated eyes, intraocular pressure was significantly lower and protein concentration and the number of infiltrating cells were significantly higher in LPS-treated eyes. Mean amplitudes of scotopic electroretinographic a- and b-waves were significantly reduced in eyes injected with LPS, compared with findings in eyes injected with vehicle. At 45 days after injection, LPS-induced alterations in photoreceptors and the middle portion of the retina were detected histologically. Results indicated that a single intravitreal injection of LPS in eyes of cats induced clinical, biochemical, functional, and histologic changes that were consistent with the main features of naturally occurring uveitis. This technique may be a useful tool in the investigation of new treatment strategies for uveitis in cats.

Neurosteroid allopregnanolone reduces ipsilateral visual cortex potentiation following unilateral optic nerve injury.

PubMed

Sergeeva, Elena G; Espinosa-Garcia, Claudia; Atif, Fahim; Pardue, Machelle T; Stein, Donald G

2018-05-02

In adult mice with unilateral optic nerve crush injury (ONC), we studied visual response plasticity in the visual cortex following stimulation with sinusoidal grating. We examined visually evoked potentials (VEP) in the primary visual cortex ipsilateral and contralateral to the crushed nerve. We found that unilateral ONC induces enhancement of visual response on the side ipsilateral to the injury that is evoked by visual stimulation to the intact eye. This enhancement was associated with supranormal spatial frequency thresholds in the intact eye when tested using optomotor response. To probe whether injury-induced disinhibition caused the potentiation, we treated animals with the neurosteroid allopregnanolone, a potent agonist of the GABA A receptor, one hour after crush and on post-injury days 3, 8, 13, and 18. Allopregnanolone diminished enhancement of the VEP and this effect was associated with the upregulated synthesis of the δ-subunit of the GABA A receptor. Our study shows a new aspect of experience-dependent plasticity following unilateral ONC. This hyper-activity in the ipsilateral visual cortex is prevented by upregulation of GABA inhibition with allopregnanolone. Our findings suggest the therapeutic potential of allopregnanolone for modulation of plasticity in certain eye and brain disorders and a possible role for disinhibition in ipsilateral hyper-activity following unilateral ONC. Copyright © 2018. Published by Elsevier Inc.

STELLATE NONHEREDITARY IDIOPATHIC FOVEOMACULAR RETINOSCHISIS ACCOMPANIED BY CONTRALATERAL PERIPHERAL RETINOSCHISIS.

PubMed

Ahmed, Daniel; Stattin, Martin; Glittenberg, Carl; Krebs, Ilse; Ansari-Shahrezaei, Siamak

2017-01-16

To present a patient with stellate nonhereditary idiopathic foveomacular retinoschisis on one eye and peripheral retinoschisis without foveal affection on the other eye. A case report with complete workup of family history and clinical examination, including multimodal imaging with optical coherence tomography and angiography, fluorescein angiography, and infrared fundus imaging. Genetic testing for gene mutation XRLS1 was performed. A white woman with unremarkable medical history presented with stellate foveal splitting of the outer plexiform layer on the right eye and peripheral splitting of the outer plexiform layer on both eyes. All known allegeable trigger factors for the existence of a hereditary or acquired foveomacular retinoschisis were ruled out either by clinical presentation or genetic testing. This led to the diagnosis of stellate nonhereditary idiopathic foveomacular retinoschisis with central involvement only present on one eye. Although peripheral schisis of the outer plexiform layer is often concomitant with central splitting in X-linked juvenile retinoschisis, this is the first known report of nonhereditary cleavage of the outer plexiform layer of the peripheral retina without central affection in a patient with documented stellate nonhereditary idiopathic foveomacular retinoschisis on the other eye. These findings suggest an accurate bilateral examination of the peripheral retina while confirming the diagnose of stellate nonhereditary idiopathic foveomacular retinoschisis.

Effect of topical epigallocatechin gallate on corneal neovascularization in rabbits.

PubMed

Koh, Chang Hyun; Lee, Hyun Soo; Chung, Sung Kun

2014-05-01

The aim of this study was to evaluate the efficacy of topical application of epigallocatechin gallate (EGCG) for the treatment of corneal neovascularization in a rabbit model. Corneal neovascularization was induced in 12 rabbits by placing a black silk suture in the corneal stroma (24 eyes) for a week. After suturing, 1 randomly chosen eye of the 12 rabbits was treated with topical EGCG at 2 different concentrations: 0.01% (group 1) and 0.1% (group 2), whereas the contralateral eyes were treated with sterilized balanced salt solution as the control. All eye drops were applied for 2 weeks after suturing. The suture materials were removed from all eyes on day 7. The surface area of corneal neovascularization was measured and analyzed in all eyes on days 7 and 14. On day 14, all eyes were extracted to measure the concentrations of vascular endothelial growth factor (VEGF) messenger RNA and cyclooxygenase-2 (COX-2) protein. The surface area of induced corneal neovascularization was significantly smaller only in group 2 compared with that of the control group on days 7 and 14 (P < 0.001). The change in surface area of corneal neovascularization after removal of the suture material was not significantly different between all 3 groups. VEGF messenger RNA levels were significantly lower in group 2 than in the control group (P < 0.001). The concentration of COX-2 was significantly lower in group 2 than in the control group (P = 0.043), but no significant difference was observed between group 1 and the control group. Topical administration of EGCG effectively inhibits corneal neovascularization in rabbits. This inhibitory effect is probably related to the suppression of VEGF and COX-2 meditated angiogenesis.

Levator Muscle Enlargement in Thyroid Eye Disease-Related Upper Eyelid Retraction.

PubMed

Davies, Michael J; Dolman, Peter J

To identify levator palpebrae superioris enlargement in thyroid eye disease (TED)-related upper eyelid retraction (ULR). Retrospective case-control. Subjects included 50 consecutive patients with unilateral thyroid eye disease-related ULR ≥ 2 mm and no previous eyelid surgery. The contralateral side was used as control. Clinical information was recorded from charts. CT scans were assessed by investigators blinded to the clinical data. A prediction of retracted side was made based on CT scan appearance and on basis of measured levator palpebrae superioris cross-sectional area at 2 defined points. Statistical analysis determined correlation between levator palpebrae superioris size and presence of ULR. The study was approved by the institutional ethics committee. Side with ULR predicted from CT scan review in over 85% of cases. Mean cross-sectional area of levator palpebrae superioris on retracted side was significantly larger than nonretracted side at 2 separate sites. Levator palpebrae superioris area was larger on retracted side compared with nonretracted side in over 85% of subjects. More than 30% of subjects had no enlargement of other extraocular muscles. Only 6% of patients had enlargement of the ipsilateral inferior rectus muscle. Levator palpebrae superioris enlargement from inflammation or scar is a factor in thyroid eye disease-related ULR. Upper eyelid retraction can be predicted from CT scan appearance in over 85% of cases. Ipsilateral inferior rectus enlargement is rare. Levator palpebrae superioris is the most commonly targeted muscle in thyroid eye disease.

Evaluations of Corneas in Eyes with Isolated Iris Coloboma.

PubMed

Karatepe Haşhaş, Arzu Seyhan; Arifoğlu, Hasan Basri; Yüce, Yudum; Duru, Necati; Ulusoy, Döndü Melek; Zararsız, Gökmen

2017-01-01

We aimed to evaluate the differences in the corneas of eyes with isolated iris coloboma. This study was designed as a prospective study. Among patients who applied to our hospital within the last 3-year period, those with isolated iris coloboma in one eye and a completely normal contralateral eye were included in the study. In addition to a complete ophthalmologic examination, all patients were scanned by Pentacam Scheimpflug camera in the dark, and a corneal endothelium cell count was taken using a Topcon Specular Microscope. Data entered using SPSS software were then evaluated by paired t-test; p < 0.05 value was considered statistically significant. Nine patients, seven men and two women, with a mean age of 35.77 ± 22.50 (range 8-60) years, were included in the study. In comparison to normal eyes, the colobomatous eyes were statistically found to have lower keratometry values in diopters (43.82 ± 2.17, 44.46 ± 1.86; p = 0.040), a greater negative asphericity (Q value) (-0.38 ± 0.07, -0.22 ± 0.20; p = 0.042), increased corneal thickness (569.78 ± 25.42, 537.33 ± 27.36; p < 0.001), decreased anterior chamber depth (2.50 ± 0.32, 2.81 ± 0.50; p = 0.005), a shallower angle (30.51 ± 10.68, 35.29 ± 9.99; p = 0.057), higher best-fit sphere (BFS) values of the anterior and posterior corneal surfaces (7.88 ± 0.39, 7.67 ± 0.37; p = 0.001; 6.40 ± 0.26, 6.23 ± 0.19; p = 0.006), larger pupil diameter (3.48 ± 0.49, 2.80 ± 0.34; p = 0.001), smaller horizontal corneal diameter (HCD) (11.06 ± 0.42; 11.26 ± 0.45; p = 0.009), and higher value of endothelial cell density (ECD) (3161 ± 431; 2923 ± 590; p = 0.031). We have determined that a number of factors such as keratometry values, particularly of the corneal endothelium, are different from those of normal eyes. These differences should be taken into account in the follow-up and treatment of eyes with iris coloboma.

More than meets the eye: the 'pink salmon patch'.

PubMed

Pallavi, Ranjita; Popescu-Martinez, Andrea

2014-08-28

Ocular adnexal lymphomas account for 1-2% of all non-Hodgkin's lymphomas. Conjunctiva is the primary site of involvement in one-third of cases. We present a case of a 47-year-old Hispanic woman who presented with left eye itching and irritation associated with a painless pink mass. Physical examination revealed the presence of a 'pink salmon-patch' involving her left medial conjunctiva. Orbital CT showed a subcentimeter left preseptal soft tissue density. Biopsy revealed a dense subepithelial lymphoid infiltrate comprised predominantly of B cells that did not coexpress CD5 or CD43. These findings were consistent with B-cell marginal zone lymphoma. Further staging assessment did not reveal disseminated disease. She had stage 1E extranodal marginal zone lymphoma as per Ann Arbor staging system. She received external beam radiotherapy to her left eye with complete resolution of the lymphoma in 2 months and continues to remain tumour free at 8-month follow-up. She will be followed up closely for development of any local (unilateral or contralateral eye) or systemic recurrence in the long run. 2014 BMJ Publishing Group Ltd.

Sensorimotor Control of the Shoulder in Professional Volleyball Players with Isolated Infraspinatus Muscle Atrophy.

PubMed

Contemori, Samuele; Biscarini, Andrea; Botti, Fabio Massimo; Busti, Daniele; Panichi, Roberto; Pettorossi, Vito Enrico

2017-06-12

Isolated infraspinatus muscle atrophy (IIMA) only affects the hitting shoulder of overhead-activity athletes, and is caused by suprascapular nerve neuropathy. No study has assessed the static and dynamic stability of the shoulder in overhead professional athletes with IIMA to reveal possible shoulder sensorimotor alterations. To assess the shoulder static stability, dynamic stability, and strength in professional volleyball players with IIMA and in healthy control players. Cross-sectional study. Research laboratory. Twenty-four male professional volleyball players (12 players with diagnosed IIMA and 12 healthy players) recruited from local volleyball teams. Static stability was evaluated with two independent force platforms and dynamic stability was assessed with the "Upper Quarter Y Balance Test". The static stability assessment was conducted in different support (single hand and both hand) and vision (open and closed eyes) conditions. Data from each test were analyzed with ANOVA and paired t-test models, to highlight statistical differences within and between groups. In addition to reduced abduction and external rotation strength, athletes with IIMA consistently demonstrated significant less static (P < 0.001) and dynamic stability (P < 0,001), compared with the contralateral shoulder and with healthy athletes. Closed eyes condition significantly enhanced the static stability deficit of the shoulder with IIMA (P = 0.039 and P = 0.034 for both hand and single hand support, respectively), but had no effect in healthy contralateral and healthy players' shoulders. This study highlights an impairment of the sensorimotor control system of the shoulder with IIMA, which likely results from both proprioceptive and strength deficits. This condition could yield subtle alteration in the functional use of the shoulder and predispose it to acute or overuse injuries. The results of this study may help athletic trainers and physical/physiotherapists to prevent shoulder injuries and create specific proprioceptive and neuromuscular training programs.

Experience-enabled enhancement of adult visual cortex function.

PubMed

Tschetter, Wayne W; Alam, Nazia M; Yee, Christopher W; Gorz, Mario; Douglas, Robert M; Sagdullaev, Botir; Prusky, Glen T

2013-03-20

We previously reported in adult mice that visuomotor experience during monocular deprivation (MD) augmented enhancement of visual-cortex-dependent behavior through the non-deprived eye (NDE) during deprivation, and enabled enhanced function to persist after MD. We investigated the physiological substrates of this experience-enabled form of adult cortical plasticity by measuring visual behavior and visually evoked potentials (VEPs) in binocular visual cortex of the same mice before, during, and after MD. MD on its own potentiated VEPs contralateral to the NDE during MD and shifted ocular dominance (OD) in favor of the NDE in both hemispheres. Whereas we expected visuomotor experience during MD to augment these effects, instead enhanced responses contralateral to the NDE, and the OD shift ipsilateral to the NDE were attenuated. However, in the same animals, we measured NMDA receptor-dependent VEP potentiation ipsilateral to the NDE during MD, which persisted after MD. The results indicate that visuomotor experience during adult MD leads to enduring enhancement of behavioral function, not simply by amplifying MD-induced changes in cortical OD, but through an independent process of increasing NDE drive in ipsilateral visual cortex. Because the plasticity is resident in the mature visual cortex and selectively effects gain of visual behavior through experiential means, it may have the therapeutic potential to target and non-invasively treat eye- or visual-field-specific cortical impairment.

Effect of lipid-based dry eye supplements on the tear film in wearers of eye cosmetics.

PubMed

Wang, Michael T M; Cho, Irene Sung Hee; Jung, Soo Hee; Craig, Jennifer P

2017-08-01

To compare the effects on tear film parameters and contamination in cosmetic eyeliner wearers, after single application of two lipid-based dry eye treatments: a lipid-containing lubricant eye drop and a phospholipid liposomal spray. Fifty participants were enrolled in a prospective, randomised, paired-eye, investigator-masked trial. Pencil eyeliner (Body Shop ® Crayon Eye Definer) was applied to the upper eyelid periocular skin of both eyes, anterior to the lash line. Baseline tear film quality was assessed fifteen minutes after eyeliner application. A lubricant drop (Systane ® Balance) was then applied to one eye (randomised), and liposomal spray (Tears Again ® ) to the contralateral eye. Tear film contamination, lipid layer grade, non-invasive tear film break-up time and tear evaporation rate were evaluated fifteen minutes post-treatment and compared to pre-treatment values. Pre-treatment measurements did not differ between eyes assigned to lubricant drop and liposomal spray. Tear film contamination was observed in a greater proportion of eyes following both treatments (both p<0.05), with no significant difference between treatments (p=0.41). Both treatments improved lipid layer thickness (both p≤0.01), but effected no significant change in non-invasive tear film break-up time or tear evaporation rate (all p>0.05). Changes in tear film parameters did not differ between treatments (all p>0.05). Both the lipid-containing lubricant eye drop and phospholipid liposomal spray result in clinically apparent tear film contamination in eyeliner cosmetic wearers. Although both treatments effected an increase in lipid layer thickness, neither displayed clinical efficacy in improving tear film stability. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Wnt Signaling in Form Deprivation Myopia of the Mice Retina

PubMed Central

Ma, Mingming; Zhang, Zhengwei; Du, Ergang; Zheng, Wenjing; Gu, Qing; Xu, Xun; Ke, Bilian

2014-01-01

Background The canonical Wnt signaling pathway plays important roles in cellular proliferation and differentiation, axonal outgrowth, cellular maintenance in retinas. Here we test the hypothesis that elements of the Wnt signaling pathway are involved in the regulation of eye growth and prevention of myopia, in the mouse form-deprivation myopia model. Methodology/Principal Findings (1) One hundred twenty-five C57BL/6 mice were randomly distributed into form-deprivation myopia and control groups. Form-deprivation myopia (FDM) was induced by suturing the right eyelid, while the control group received no treatment. After 1, 2, and 4 weeks of treatment, eyes were assessed in vivo by cycloplegic retinoscopic refraction and axial length measurement by photography or A-scan ultrasonography. Levels of retinal Wnt2b, Fzd5 and β-catenin mRNA and protein were evaluated using RT-PCR and western blotting, respectively. (2) Another 96 mice were divided into three groups: control, drugs-only, and drugs+FDM (by diffuser). Experimentally treated eyes in the last two groups received intravitreal injections of vehicle or the proteins, DKK-1 (Wnt-pathway antagonist) or Norrin (Wnt-pathway agonist), once every three days, for 4 injections total. Axial length and retinoscopic refraction were measured on the 14th day of form deprivation. Following form-deprivation for 1, 2, and 4 weeks, FDM eyes had a relatively myopic refractive error, compared with contralateral eyes. There were no significant differences in refractive error between right and left eye in control group. The amounts of Wnt2b, Fzd5 and β-catenin mRNA and protein were significantly greater in form-deprived myopia eyes than in control eyes.DKK-1 (antagonist) reduced the myopic shift in refractive error and increase in axial elongation, whereas Norrin had the opposite effect in FDM eyes. Conclusions/Significance Our studies provide the first evidence that the Wnt2b signaling pathway may play a role in the development and progression of form-deprivation myopia, in a mammalian model. PMID:24755605

Wnt signaling in form deprivation myopia of the mice retina.

PubMed

Ma, Mingming; Zhang, Zhengwei; Du, Ergang; Zheng, Wenjing; Gu, Qing; Xu, Xun; Ke, Bilian

2014-01-01

The canonical Wnt signaling pathway plays important roles in cellular proliferation and differentiation, axonal outgrowth, cellular maintenance in retinas. Here we test the hypothesis that elements of the Wnt signaling pathway are involved in the regulation of eye growth and prevention of myopia, in the mouse form-deprivation myopia model. (1) One hundred twenty-five C57BL/6 mice were randomly distributed into form-deprivation myopia and control groups. Form-deprivation myopia (FDM) was induced by suturing the right eyelid, while the control group received no treatment. After 1, 2, and 4 weeks of treatment, eyes were assessed in vivo by cycloplegic retinoscopic refraction and axial length measurement by photography or A-scan ultrasonography. Levels of retinal Wnt2b, Fzd5 and β-catenin mRNA and protein were evaluated using RT-PCR and western blotting, respectively. (2) Another 96 mice were divided into three groups: control, drugs-only, and drugs+FDM (by diffuser). Experimentally treated eyes in the last two groups received intravitreal injections of vehicle or the proteins, DKK-1 (Wnt-pathway antagonist) or Norrin (Wnt-pathway agonist), once every three days, for 4 injections total. Axial length and retinoscopic refraction were measured on the 14th day of form deprivation. Following form-deprivation for 1, 2, and 4 weeks, FDM eyes had a relatively myopic refractive error, compared with contralateral eyes. There were no significant differences in refractive error between right and left eye in control group. The amounts of Wnt2b, Fzd5 and β-catenin mRNA and protein were significantly greater in form-deprived myopia eyes than in control eyes.DKK-1 (antagonist) reduced the myopic shift in refractive error and increase in axial elongation, whereas Norrin had the opposite effect in FDM eyes. Our studies provide the first evidence that the Wnt2b signaling pathway may play a role in the development and progression of form-deprivation myopia, in a mammalian model.

The effects of anterior arcuate and dorsomedial frontal cortex lesions on visually guided eye movements: 2. Paired and multiple targets.

PubMed

Schiller, P H; Chou, I

2000-01-01

This study examined the effects of anterior arcuate and dorsomedial frontal cortex lesions on the execution of saccadic eye movements made to paired and multiple targets in rhesus monkeys. Identical paired targets were presented with various temporal asynchronies to determine the temporal offset required to yield equal probability choices to either target. In the intact animal equal probability choices were typically obtained when the targets appeared simultaneously. After unilateral anterior arcuate lesions a major shift arose in the temporal offset required to obtain equal probability choices for paired targets that necessitated presenting the target in the hemifield contralateral to the lesion more than 100 ms prior to the target in the ipsilateral hemifield. This deficit was still pronounced 1 year after the lesion. Dorsomedial frontal cortex lesions produced much smaller but significant shifts in target selection that recovered more rapidly. Paired lesions produced deficits similar to those observed with anterior arcuate lesions alone. Major deficits were also observed on a multiple target temporal discrimination task after anterior arcuate but not after dorsomedial frontal cortex lesions. These results suggest that the frontal eye fields that reside in anterior bank of the arcuate sulcus play an important role in temporal processing and in target selection. Dorsomedial frontal cortex, that contains the medial eye fields, plays a much less important role in the execution of these tasks.

A Single Intravitreal Injection of Ranibizumab Provides No Neuroprotection in a Nonhuman Primate Model of Moderate-to-Severe Nonarteritic Anterior Ischemic Optic Neuropathy.

PubMed

Miller, Neil R; Johnson, Mary A; Nolan, Theresa; Guo, Yan; Bernstein, Steven L

2015-12-01

Ranibizumab, a vascular endothelial growth factor-antagonist, is said to be neuroprotective when injected intravitreally in patients with nonarteritic anterior ischemic optic neuropathy (NAION). We evaluated the efficacy of a single intravitreal (IVT) injection of ranibizumab in a nonhuman primate model of NAION (pNAION). We induced pNAION in one eye of four adult male rhesus monkeys using a laser-activated rose Bengal induction method. We then immediately injected the eye with either ranibizumab or normal saline (NS) intravitreally. We performed a clinical assessment, optical coherence tomography, electrophysiological testing, fundus photography, and fluorescein angiography in three of the animals (one animal developed significant retinal hemorrhages and, therefore, could not be analyzed completely) prior to induction, 1 day and 1, 2, and 4 weeks thereafter. Following the 4-week analysis of the first eye, we induced pNAION in the contralateral eye and then injected either ranibizumab or NS, whichever substance had not been injected in the first eye. We euthanized all animals 5 to 12 weeks after the final assessment of the second eye and performed both immunohistochemical and light and electron microscopic analyses of the retina and optic nerves of both eyes. A single IVT dose of ranibizumab administered immediately after induction of pNAION resulted in no significant reduction of clinical, electrophysiological, or histologic damage compared with vehicle-injected eyes. A single IVT dose of ranibizumab is not neuroprotective when administered immediately after induction of pNAION.

Monocular tool control, eye dominance, and laterality in New Caledonian crows.

PubMed

Martinho, Antone; Burns, Zackory T; von Bayern, Auguste M P; Kacelnik, Alex

2014-12-15

Tool use, though rare, is taxonomically widespread, but morphological adaptations for tool use are virtually unknown. We focus on the New Caledonian crow (NCC, Corvus moneduloides), which displays some of the most innovative tool-related behavior among nonhumans. One of their major food sources is larvae extracted from burrows with sticks held diagonally in the bill, oriented with individual, but not species-wide, laterality. Among possible behavioral and anatomical adaptations for tool use, NCCs possess unusually wide binocular visual fields (up to 60°), suggesting that extreme binocular vision may facilitate tool use. Here, we establish that during natural extractions, tool tips can only be viewed by the contralateral eye. Thus, maintaining binocular view of tool tips is unlikely to have selected for wide binocular fields; the selective factor is more likely to have been to allow each eye to see far enough across the midsagittal line to view the tool's tip monocularly. Consequently, we tested the hypothesis that tool side preference follows eye preference and found that eye dominance does predict tool laterality across individuals. This contrasts with humans' species-wide motor laterality and uncorrelated motor-visual laterality, possibly because bill-held tools are viewed monocularly and move in concert with eyes, whereas hand-held tools are visible to both eyes and allow independent combinations of eye preference and handedness. This difference may affect other models of coordination between vision and mechanical control, not necessarily involving tools. Copyright © 2014 Elsevier Ltd. All rights reserved.

A case of unilateral circumscribed posterior keratoconus evaluated by three different imaging tools: optical coherence tomography, videokeratography, and Scheimpflug corneal tomography.

PubMed

Spadea, Leopoldo; Maraone, Giorgia; Cagini, Carlo

2017-02-01

Posterior keratoconus is a rare corneal anomaly which is part of the ectatic corneal disorders. We report a clinical presentation of a unilateral posterior keratoconus in a 42-year-old man. At the time of presentation, corrected distance visual acuity (CDVA) was 20/20 with a correction of +2.50 +2.50 × 90° in the right eye and 20/40 with +1 +3.00 × 105° in the left eye. Slit lamp microscopy showed in the left eye an evidence of corneal thinning with a mild anterior protrusion and a remarkable posterior excavation. The intraocular pressure was 19 mmHg in right eye and 16 mmHg in left eye. Ultrasound pachymetry showed a minimum corneal thickness of 556 μ in right eye and 289 μ in left eye. The anterior segment optical coherence tomography (AS-OCT) revealed central corneal thinning and showed a reduced epithelial thickness. Videokeratography showed an increase of the corneal curvature in a defined area with central steepening in the area of the posterior corneal depression with gradual paracentral flattening. The description of this case underlines the importance of this instruments such us AS-OCT and corneal topography in diagnosis of posterior keratoconus. It can also be observed that in the contralateral eye there are no signs of ectasia as in the rare condition of unilateral keratoconus.

Eye movements and abducens motoneuron behavior after cholinergic activation of the nucleus reticularis pontis caudalis.

PubMed

Márquez-Ruiz, Javier; Escudero, Miguel

2010-11-01

the aim of this work was to characterize eye movements and abducens (ABD) motoneuron behavior after cholinergic activation of the nucleus reticularis pontis caudalis (NRPC). six female adult cats were prepared for chronic recording of eye movements (using the scleral search-coil technique), electroencephalography, electromyography, ponto-geniculo-occipital (PGO) waves in the lateral geniculate nucleus, and ABD motoneuron activities after microinjections of the cholinergic agonist carbachol into the NRPC. unilateral microinjections of carbachol in the NRPC induced tonic and phasic phenomena in the oculomotor system. Tonic effects consisted of ipsiversive rotation to the injected side, convergence, and downward rotation of the eyes. Phasic effects consisted of bursts of rhythmic rapid eye movements directed contralaterally to the injected side along with PGO-like waves in the lateral geniculate and ABD nuclei. Although tonic effects were dependent on the level of drowsiness, phasic effects were always present and appeared along with normal saccades when the animal was vigilant. ABD motoneurons showed phasic activities associated with ABD PGO-like waves during bursts of rapid eye movements, and tonic and phasic activities related to eye position and velocity during alertness. the cholinergic activation of the NRPC induces oculomotor phenomena that are somewhat similar to those described during REM sleep. A precise comparison of the dynamics and timing of the eye movements further suggests that a temporal organization of both NRPCs is needed to reproduce the complexity of the oculomotor behavior during REM sleep.

Stimulus Load and Oscillatory Activity in Higher Cortex

PubMed Central

Kornblith, Simon; Buschman, Timothy J.; Miller, Earl K.

2016-01-01

Exploring and exploiting a rich visual environment requires perceiving, attending, and remembering multiple objects simultaneously. Recent studies have suggested that this mental “juggling” of multiple objects may depend on oscillatory neural dynamics. We recorded local field potentials from the lateral intraparietal area, frontal eye fields, and lateral prefrontal cortex while monkeys maintained variable numbers of visual stimuli in working memory. Behavior suggested independent processing of stimuli in each hemifield. During stimulus presentation, higher-frequency power (50–100 Hz) increased with the number of stimuli (load) in the contralateral hemifield, whereas lower-frequency power (8–50 Hz) decreased with the total number of stimuli in both hemifields. During the memory delay, lower-frequency power increased with contralateral load. Load effects on higher frequencies during stimulus encoding and lower frequencies during the memory delay were stronger when neural activity also signaled the location of the stimuli. Like power, higher-frequency synchrony increased with load, but beta synchrony (16–30 Hz) showed the opposite effect, increasing when power decreased (stimulus presentation) and decreasing when power increased (memory delay). Our results suggest roles for lower-frequency oscillations in top-down processing and higher-frequency oscillations in bottom-up processing. PMID:26286916

Evidence-based guidelines for recommending cochlear implantation for postlingually deafened adults.

PubMed

Leigh, Jaime R; Moran, Michelle; Hollow, Rodney; Dowell, Richard C

2016-01-01

Adult selection criteria for cochlear implantation have been developed based on analysis of the post-operative performance of a large group of postlingually deafened adults. Original criteria published in 2004 were reviewed and amended to reflect outcomes currently being achieved by implant recipients. Retrospective review of 12-month post-operative speech perception performance of adults implanted at the Eye and Ear Hospital, Melbourne, Australia. A total of 382 postlingually deafened adults, using a Freedom, Nucleus 5, or CI422 Slim Straight cochlear implant were used to create a comparative set of data. Revised guidelines suggest that adults with postlingual hearing loss can now be considered cochlear implant candidates if they obtain scores of up to 55% for open-set phonemes in quiet in the ear to be implanted. Functional benefit may vary depending on the recipients' contralateral hearing. This study supports the provision of cochlear implants to candidates with significant residual hearing when at least one ear meets the criterion outlined above. Patient-specific counseling is required to ensure the potential to benefit predicted by the current model is acceptable to the individual patient and their family. Counseling regarding functional benefit must take into consideration hearing in the contralateral ear.

Unilateral optic nerve transection alters light response of suprachiasmatic nucleus and intergeniculate leaflet

NASA Technical Reports Server (NTRS)

Tang, I-Hsiung; Murakami, Dean M.; Fuller, Charles A.

2002-01-01

The suprachiasmatic nucleus (SCN), the circadian pacemaker, receives photic input directly from the retina to synchronize the pacemaker to the environment. Additionally, the intergeniculate leaflet (IGL), which innervates the SCN, is known to modulate the retinal photic input to the SCN. To further understand the role of the IGL in mediating the photic input to the SCN, this study examined the effects of unilateral optic nerve transection (UONx) on the photic response of the SCN and IGL in adult and neonatal hamsters. UONx led to an overall reduction in light-induced c-Fos expression in the SCN and IGL. The c-Fos expression was greater in the SCN ipsilateral to the remaining eye, despite a symmetrically bilateral retinohypothalamic tract projection as revealed by intraocular injection of horseradish peroxidase. In contrast, UONx led to a greater c-Fos expression in the contralateral IGL. The contralateral IGL of UONx animals also revealed more neuropeptide Y-immunoreactive neurons, while the ipsilateral SCN of these animals exhibited a denser neuropeptide Y terminal field. The neonates with UONx showed a similar pattern with a slight compensation of the photic-induced c-Fos in the SCN. This study suggests that the IGL may have an ipsilateral inhibitory effect in mediating retinal photic input to the SCN.

Determinants of macular pigment optical density and its relation to age-related maculopathy: results from the Muenster Aging and Retina Study (MARS).

PubMed

Dietzel, Martha; Zeimer, Meike; Heimes, Britta; Claes, Birte; Pauleikhoff, Daniel; Hense, Hans-Werner

2011-06-01

The controversial protective effect of macular pigment (MP), consisting of lutein (L) and zeaxantin (Z), in age-related maculopathy (ARM) and its late-stage, age-related macular degeneration (AMD) is discussed. Determinants of MP optical density (MPOD) and its relation to ARM were investigated. MPOD was accessed at eccentricities of 0.5° and 2.0° from the fovea in 369 participants in the 2.6-year follow-up examination of the prospective Muenster Aging and Retina Study using dual-wavelength analysis of autofluorescence images. ARM was graded from standardized fundus photographs according to the International Classification System. MPOD at 0.5° and 2.0° between pairs and within single eyes was strongly correlated (P < 0.001). Smoking and body mass index showed moderately inverse associations with MPOD at 2.0°, and age was positively related to MPOD at both eccentricities. Serum L, measured at the baseline examination, was significantly associated with MPOD measured at follow-up. Likewise, use of L/Z-containing supplements raised MPOD. Crude mean MPOD increased with ascending stage of ARM. However, adjustment for influential factors and exclusion of L supplement users removed differences of mean MPOD between ARM stages. Considering further the accompanying eye, study eyes with ARM had significantly higher MPOD when the contralateral eye had AMD. MPOD levels showed a high degree of intraindividual concordance and interindividual variability. Long-standing serum L levels, and in particular L supplementation, were the strongest determinants of MPOD. The hypothetical inverse association between MPOD and ARM stage was not confirmed.

The Deceptively Simple N170 Reflects Network Information Processing Mechanisms Involving Visual Feature Coding and Transfer Across Hemispheres

PubMed Central

Ince, Robin A. A.; Jaworska, Katarzyna; Gross, Joachim; Panzeri, Stefano; van Rijsbergen, Nicola J.; Rousselet, Guillaume A.; Schyns, Philippe G.

2016-01-01

A key to understanding visual cognition is to determine “where”, “when”, and “how” brain responses reflect the processing of the specific visual features that modulate categorization behavior—the “what”. The N170 is the earliest Event-Related Potential (ERP) that preferentially responds to faces. Here, we demonstrate that a paradigmatic shift is necessary to interpret the N170 as the product of an information processing network that dynamically codes and transfers face features across hemispheres, rather than as a local stimulus-driven event. Reverse-correlation methods coupled with information-theoretic analyses revealed that visibility of the eyes influences face detection behavior. The N170 initially reflects coding of the behaviorally relevant eye contralateral to the sensor, followed by a causal communication of the other eye from the other hemisphere. These findings demonstrate that the deceptively simple N170 ERP hides a complex network information processing mechanism involving initial coding and subsequent cross-hemispheric transfer of visual features. PMID:27550865

The U.S. Army Surface Ablation Study: comparison of PRK, MMC-PRK, and LASEK in moderate to high myopia.

PubMed

Sia, Rose K; Ryan, Denise S; Edwards, Jayson D; Stutzman, Richard D; Bower, Kraig S

2014-04-01

To compare visual outcomes following photorefractive keratectomy (PRK), PRK with mitomycin C (MMC-PRK), and LASEK in moderate and high myopia in military personnel. This prospective, randomized contralateral eye study included 167 patients 21 years or older with manifest spherical equivalent -5.99 ± 1.40 diopters (D) (range: -3.88 to -9.38 D) randomized to either MMC-PRK or LASEK treatment in their dominant eye and conventional PRK without MMC in the fellow eye. All procedures were performed using the LADARVision 4000 Excimer Laser System (Alcon Surgical Inc., Ft. Worth, TX). High- and low-contrast visual acuities, manifest refraction, endothelial cell count, and corneal haze were evaluated up to 12 months postoperatively. At 12 months postoperatively, visual outcomes were comparable among the treatment groups. Corneal haze of any grade was less common in MMC-PRK compared to PRK at 1 month (21.4% vs 31.0%; P < .01) and 3 months (12.8% vs 35.9%; P = .03) postoperatively; it was also less common in MMC-PRK compared to LASEK at 1 month (21.4% vs 55.9%; P < .01), 3 months (12.8% vs 42.4%; P < .01), and 6 months (12.2% vs 36.4%; P = .03) postoperatively. Haze rate (grade 0.5 or higher) was comparable between LASEK and PRK. Clinically significant haze (grade 2 or higher) developed after PRK (4 eyes) and LASEK (2 eyes), but not after MMC-PRK. MMC-PRK showed some benefits in minimizing corneal haze formation. One year after surgery, there was no discernible difference in the postoperative refractive outcomes among the three methods. Copyright 2014, SLACK Incorporated.

Sustained neuroprotection from a single intravitreal injection of PGJ2 in a rodent model of anterior ischemic optic neuropathy.

PubMed

Touitou, Valerie; Johnson, Mary A; Guo, Yan; Miller, Neil R; Bernstein, Steven L

2013-11-11

Nonarteritic anterior ischemic optic neuropathy (NAION) is the most common cause of sudden optic nerve-related vision loss in persons older than 50 in the United States. There currently is no treatment for this disorder. We previously showed that systemic administration of 15-deoxy, delta (12, 14) prostaglandin J2 (PGJ2) is neuroprotective in our rodent model of AION (rAION). In this study, we determined if a single intravitreal (IVT) injection of PGJ2 is neuroprotective after rAION, and if this method of administration is toxic to the retina, optic nerve, or both. TOXICITY was assessed after a single IVT injection of PGJ2 in one eye and PBS in the contralateral eye of normal, adult Long-Evans rats. EFFICACY was assessed by inducing rAION in one eye and injecting either PGJ2 or vehicle immediately following induction, with the fellow eye serving as naïve control. Visual evoked potentials (VEPs) and ERGs were performed before induction and at specific intervals thereafter. Animals were euthanized 30 days after induction, after which immunohistochemistry, transmission electron microscopy, and quantitative stereology of retinal ganglion cell (RGC) numbers were performed. IVT PGJ2 did not alter the VEP or ERG compared with PBS-injected control eyes, and neither IVT PGJ2 nor PBS reduced overall RGC numbers. IVT PGJ2 preserved VEP amplitude, reduced optic nerve edema, and resulted in significant preservation of RGCs and axons in eyes with rAION. A single IVT injection of PGJ2 is nontoxic to the retina and optic nerve and neuroprotective when given immediately after rAION induction.

Early light deprivation effects on human cone-driven retinal function.

PubMed

Esposito Veneruso, Paolo; Ziccardi, Lucia; Magli, Giulia; Parisi, Vincenzo; Falsini, Benedetto; Magli, Adriano

2017-03-01

To assess whether the early light deprivation induced by congenital cataract may influence the cone-driven retinal function in humans. Forty-one patients affected by congenital cataract (CC) who had undergone uncomplicated cataract extraction surgery and intraocular lens implant, and 14 healthy subjects (HS) were enrolled. All patients underwent complete ophthalmological and orthoptic evaluations and best-corrected visual acuity (BCVA) measurement; light-adapted full-field electroretinograms (ERG) and photopic negative responses (PhNR) were recorded to obtain a reliable measurement of the outer/inner retinal function and of the retinal ganglion cells' function respectively. Mean values of light-adapted ERG a- and b-wave and PhNR amplitude of CC eyes were significantly reduced and photopic ERG b-wave implicit time mean values were significantly delayed when compared to HS ones. When studying photopic ERG mean amplitudes at 5 ms, significant differences were found when comparing CC and control eyes. In CC eyes, statistically significant correlations were found between a- and b- wave amplitudes and PhNR amplitudes. No significant correlations were found between ERG parameters and BCVA, as well as between the age of CC patients at surgery and the time elapsed from lens extraction. No significant differences were found when functional parameters of bilateral and unilateral congenital cataract (uCC) eyes were compared, however uCC eyes showed significant differences when compared with contralateral healthy eyes. We found a significant impairment of cone-driven retinal responses in patients with a history of congenital cataract. These changes might result from the long-lasting effects of early light deprivation on the cone retinal pathways. Our findings support the relevance of retinal involvement in deficits induced by early light deprivation. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Upregulation of regulator of G-protein signaling 2 in the sclera of a form deprivation myopic animal model

PubMed Central

Zou, Leilei; Liu, Rui; Zhang, Xiaohui; Chu, Renyuan; Dai, Jinhui; Zhou, Hao

2014-01-01

Purpose Scleral remodeling is an important mechanism underlying the development of myopia. Atropine, an antagonist of G protein-coupled muscarinic receptors, is currently used as an off-label treatment for myopia. Regulator of G-protein signaling 2 (RGS2) functions as an intracellular selective inhibitor of muscarinic receptors. In this study we measured scleral RGS2 expression and scleral remodeling in an animal model of myopia in the presence or absence of atropine treatment. Methods Guinea pigs were assigned to four groups: normal (free of form deprivation), form deprivation myopia (FDM) for 4 weeks, FDM treated with saline, and FDM treated with atropine. Biometric measurements were then performed. RGS2 expression levels and scleral remodeling, including scleral thickness and collagen type I expression, were compared among the four groups. Results Compared with normal eyes and contralateral control eyes, the FDM eyes had the most prominent changes in refraction, axial length, and scleral remodeling, indicating myopia. There was no significant difference between control and normal eyes. Hematoxylin and eosin staining showed that the scleral thickness was significantly thinner in the posterior pole region of FDM eyes compared to normal eyes. Real-time PCR and western blot analysis showed a significant decrease in posterior scleral collagen type I mRNA and protein expression in the FDM eyes compared to the normal eyes. The FDM eyes also had increased levels of RGS2 mRNA and protein expression in the sclera. Atropine treatment attenuated the FDM-induced changes in refraction, axial length, and scleral remodeling. Interestingly, atropine treatment significantly increased collagen type I mRNA expression but decreased RGS2 mRNA and protein expression in the sclera of the FDM eyes. Conclusions We identified a significant RGS2 upregulation and collagen type I downregulation in the sclera of FDM eyes, which could be partially attenuated by atropine treatment. Our data suggest that targeting dysregulated RGS2 may provide a novel strategy for development of therapeutic agents to suppress myopia progression. PMID:25018620

[Investigation of color vision in acute unilateral optic neuritis using a web-based color vision test].

PubMed

Kuchenbecker, J; Blum, M; Paul, F

2016-03-01

In acute unilateral optic neuritis (ON) color vision defects combined with a decrease in visual acuity and contrast sensitivity frequently occur. This study investigated whether a web-based color vision test is a reliable detector of acquired color vision defects in ON and, if so, which charts are particularly suitable. In 12 patients with acute unilateral ON, a web-based color vision test ( www.farbsehtest.de ) with 25 color plates (16 Velhagen/Broschmann and 9 Ishihara color plates) was performed. For each patient the affected eye was tested first and then the unaffected eye. The mean best-corrected distance visual acuity (BCDVA) in the ON eye was 0.36 ± 0.20 and 1.0 ± 0.1 in the contralateral eye. The number of incorrectly read plates correlated with the visual acuity. For the ON eye a total of 134 plates were correctly identified and 166 plates were incorrectly identified, while for the disease-free fellow eye, 276 plates were correctly identified and 24 plates were incorrectly identified. Both of the blue/yellow plates were identified correctly 14 times and incorrectly 10 times using the ON eye and exclusively correctly (24 times) using the fellow eye. The Velhagen/Broschmann plates were incorrectly identified significantly more frequently in comparison with the Ishihara plates. In 4 out of 16 Velhagen/Broschmann plates and 5 out of 9 Ishihara plates, no statistically significant differences between the ON eye and the fellow eye could be detected. The number of incorrectly identified plates correlated with a decrease in visual acuity. Red/green and blue/yellow plates were incorrectly identified significantly more frequently with the ON eye, while the Velhagen/Broschmann color plates were incorrectly identified significantly more frequently than the Ishihara color plates. Thus, under defined test conditions the web-based color vision test can also be used to detect acquired color vision defects, such as those caused by ON. Optimization of the test by altering the combination of plates may be a useful next step.

Radiographic Risk Factors for Contralateral Rupture in Dogs with Unilateral Cranial Cruciate Ligament Rupture

PubMed Central

Chuang, Connie; Ramaker, Megan A.; Kaur, Sirjaut; Csomos, Rebecca A.; Kroner, Kevin T.; Bleedorn, Jason A.; Schaefer, Susan L.; Muir, Peter

2014-01-01

Background Complete cranial cruciate ligament rupture (CR) is a common cause of pelvic limb lameness in dogs. Dogs with unilateral CR often develop contralateral CR over time. Although radiographic signs of contralateral stifle joint osteoarthritis (OA) influence risk of subsequent contralateral CR, this risk has not been studied in detail. Methodology/Principal Findings We conducted a retrospective longitudinal cohort study of client-owned dogs with unilateral CR to determine how severity of radiographic stifle synovial effusion and osteophytosis influence risk of contralateral CR over time. Detailed survival analysis was performed for a cohort of 85 dogs after case filtering of an initial sample population of 513 dogs. This population was stratified based on radiographic severity of synovial effusion (graded on a scale of 0, 1, and 2) and severity of osteophytosis (graded on a scale of 0, 1, 2, and 3) of both index and contralateral stifle joints using a reproducible scoring method. Severity of osteophytosis in the index and contralateral stifles was significantly correlated. Rupture of the contralateral cranial cruciate ligament was significantly influenced by radiographic OA in both the index and contralateral stifles at diagnosis. Odds ratio for development of contralateral CR in dogs with severe contralateral radiographic stifle effusion was 13.4 at one year after diagnosis and 11.4 at two years. Odds ratio for development of contralateral CR in dogs with severe contralateral osteophytosis was 9.9 at one year after diagnosis. These odds ratios were associated with decreased time to contralateral CR. Breed, age, body weight, gender, and tibial plateau angle did not significantly influence time to contralateral CR. Conclusion Subsequent contralateral CR is significantly influenced by severity of radiographic stifle effusion and osteophytosis in the contralateral stifle, suggesting that synovitis and arthritic joint degeneration are significant factors in the disease mechanism underlying the arthropathy. PMID:25254499

Avoidance of a moving threat in the common chameleon (Chamaeleo chamaeleon): rapid tracking by body motion and eye use.

PubMed

Lev-Ari, Tidhar; Lustig, Avichai; Ketter-Katz, Hadas; Baydach, Yossi; Katzir, Gadi

2016-08-01

A chameleon (Chamaeleo chamaeleon) on a perch responds to a nearby threat by moving to the side of the perch opposite the threat, while bilaterally compressing its abdomen, thus minimizing its exposure to the threat. If the threat moves, the chameleon pivots around the perch to maintain its hidden position. How precise is the body rotation and what are the patterns of eye movement during avoidance? Just-hatched chameleons, placed on a vertical perch, on the side roughly opposite to a visual threat, adjusted their position to precisely opposite the threat. If the threat were moved on a horizontal arc at angular velocities of up to 85°/s, the chameleons co-rotated smoothly so that (1) the angle of the sagittal plane of the head relative to the threat and (2) the direction of monocular gaze, were positively and significantly correlated with threat angular position. Eye movements were role-dependent: the eye toward which the threat moved maintained a stable gaze on it, while the contralateral eye scanned the surroundings. This is the first description, to our knowledge, of such a response in a non-flying terrestrial vertebrate, and it is discussed in terms of possible underlying control systems.

Interhemispheric Transfer Time Asymmetry of Visual Information Depends on Eye Dominance: An Electrophysiological Study

PubMed Central

Chaumillon, Romain; Blouin, Jean; Guillaume, Alain

2018-01-01

The interhemispheric transfer of information is a fundamental process in the human brain. When a visual stimulus appears eccentrically in one visual-hemifield, it will first activate the contralateral hemisphere but also the ipsilateral one with a slight delay due to the interhemispheric transfer. This interhemispheric transfer of visual information is believed to be faster from the right to the left hemisphere in right-handers. Such an asymmetry is considered as a relevant fact in the context of the lateralization of the human brain. We show here using current source density (CSD) analyses of visually evoked potential (VEP) that, in right-handers and, to a lesser extent in left-handers, this asymmetry is in fact dependent on the sighting eye dominance, the tendency we have to prefer one eye for monocular tasks. Indeed, in right-handers, a faster interhemispheric transfer of visual information from the right to left hemisphere was observed only in participants with a right dominant eye (DE). Right-handers with a left DE showed the opposite pattern, with a faster transfer from the left to the right hemisphere. In left-handers, albeit a smaller number of participants has been tested and hence confirmation is required, only those with a right DE showed an asymmetrical interhemispheric transfer with a faster transfer from the right to the left hemisphere. As a whole these results demonstrate that eye dominance is a fundamental determinant of asymmetries in interhemispheric transfer of visual information and suggest that it is an important factor of brain lateralization. PMID:29515351

Interhemispheric Transfer Time Asymmetry of Visual Information Depends on Eye Dominance: An Electrophysiological Study.

PubMed

Chaumillon, Romain; Blouin, Jean; Guillaume, Alain

2018-01-01

The interhemispheric transfer of information is a fundamental process in the human brain. When a visual stimulus appears eccentrically in one visual-hemifield, it will first activate the contralateral hemisphere but also the ipsilateral one with a slight delay due to the interhemispheric transfer. This interhemispheric transfer of visual information is believed to be faster from the right to the left hemisphere in right-handers. Such an asymmetry is considered as a relevant fact in the context of the lateralization of the human brain. We show here using current source density (CSD) analyses of visually evoked potential (VEP) that, in right-handers and, to a lesser extent in left-handers, this asymmetry is in fact dependent on the sighting eye dominance, the tendency we have to prefer one eye for monocular tasks. Indeed, in right-handers, a faster interhemispheric transfer of visual information from the right to left hemisphere was observed only in participants with a right dominant eye (DE). Right-handers with a left DE showed the opposite pattern, with a faster transfer from the left to the right hemisphere. In left-handers, albeit a smaller number of participants has been tested and hence confirmation is required, only those with a right DE showed an asymmetrical interhemispheric transfer with a faster transfer from the right to the left hemisphere. As a whole these results demonstrate that eye dominance is a fundamental determinant of asymmetries in interhemispheric transfer of visual information and suggest that it is an important factor of brain lateralization.

Slump Test: Effect of Contralateral Knee Extension on Response Sensations in Asymptomatic Subjects and Cadaver Study.

PubMed

Shacklock, Michael; Yee, Brian; Van Hoof, Tom; Foley, Russ; Boddie, Keith; Lacey, Erin; Poley, J Bryan; Rade, Marinko; Kankaanpää, Markku; Kröger, Heikki; Airaksinen, Olavi

2016-02-01

Part 1: A randomized, single-blind study on the effect of contralateral knee extension on sensations produced by the slump test (ST) in asymptomatic subjects. Part 2: A cadaver study simulating the nerve root behavior of part 1. Part 1: Test if contralateral knee extension consistently reduces normal stretch sensations with the ST.Part 2: Ascertain in cadavers an explanation for the results. In asymptomatic subjects, contralateral knee extension reduces stretch sensations with the ST. In sciatica patients, contralateral SLR also can temporarily reduce sciatica. We studied this methodically in asymptomatic subjects before considering a clinical population. Part 1: Sixty-one asymptomatic subjects were tested in control (ST), sham, or intervention (contralateral ST) groups and their sensation response intensity compared.Part 2: Caudal tension was applied to the L5 nerve root of 3 cadavers and tension behavior of the contralateral neural tissue recorded visually. Part 1: Reduction of stretch sensations occurred in the intervention group but not in control and sham groups (P ≤ 0.001).Part 2: Tension in the contralateral lumbar nerve roots and dura reduced in a manner consistent with the responses in the intervention (contralateral ST) group. Part 1: In asymptomatic subjects, normal thigh stretch sensations with the ST reduced consistently with the contralateral ST, showing that this is normal and may now be compared with patients with sciatica.Part 2: Contralateral reduction in lumbar neural tension with unilateral application of tension-producing movements also occurred in cadavers, supporting the proposed explanatory hypothesis.

The sophisticated visual system of a tiny Cambrian crustacean: analysis of a stalked fossil compound eye

PubMed Central

Schoenemann, Brigitte; Castellani, Christopher; Clarkson, Euan N. K.; Haug, Joachim T.; Maas, Andreas; Haug, Carolin; Waloszek, Dieter

2012-01-01

Fossilized compound eyes from the Cambrian, isolated and three-dimensionally preserved, provide remarkable insights into the lifestyle and habitat of their owners. The tiny stalked compound eyes described here probably possessed too few facets to form a proper image, but they represent a sophisticated system for detecting moving objects. The eyes are preserved as almost solid, mace-shaped blocks of phosphate, in which the original positions of the rhabdoms in one specimen are retained as deep cavities. Analysis of the optical axes reveals four visual areas, each with different properties in acuity of vision. They are surveyed by lenses directed forwards, laterally, backwards and inwards, respectively. The most intriguing of these is the putatively inwardly orientated zone, where the optical axes, like those orientated to the front, interfere with axes of the other eye of the contralateral side. The result is a three-dimensional visual net that covers not only the front, but extends also far laterally to either side. Thus, a moving object could be perceived by a two-dimensional coordinate (which is formed by two axes of those facets, one of the left and one of the right eye, which are orientated towards the moving object) in a wide three-dimensional space. This compound eye system enables small arthropods equipped with an eye of low acuity to estimate velocity, size or distance of possible food items efficiently. The eyes are interpreted as having been derived from individuals of the early crustacean Henningsmoenicaris scutula pointing to the existence of highly efficiently developed eyes in the early evolutionary lineage leading towards the modern Crustacea. PMID:22048954

Effects of silicone hydrogel contact lenses on ocular surface after Sub-Bowman's Keratomileusis.

PubMed

Gao, Shaohui; Wu, Junshu; Li, Lili; Wang, Yong; Zhong, Xingwu

2013-11-01

To evaluate the efficacy of silicone hydrogel contact lenses on ocular surface after Sub-Bowman Keratomileusis (SBK). Forty-six patients suffered from myopia underwent a bilateral SBK. Post-operatively, one eye of each patient wore a PureVision contact lens for 24 h as a treated eye and the contralateral eye was as a blank control. Afterwards, corneal fluorescein (FL) staining, tear break-up time (TBUT), schirmer I test (SIT), central corneal thickness (CCT), ocular surface disease index (OSDI), corneal hysteresis (CH), corneal resistance factor (CRF) and corneal flap complications were assessed 1 d (except for CH and CRF), 1 week, 1 month and 3 months postoperatively. Following SBK, in contrast to the control, corneal fluorescein staining of treated eyes were significantly reduced and tear break-up time of treated eyes were significantly improved at 1 d and 1 week after SBK. However, Schirmer I test of treated and control eyes were not different after SBK. Central corneal thickness of treated eyes were significantly thinner than that of control at 1 d after SBK, however, there were no differences at other time points. Ocular surface disease index of treated eyes were obviously alleviated more than that of control at 1 d after SBK, but no differences were found at other visits. Moreover, Corneal hysteresis and corneal resistance factor of treated and un-treated eyes were not different after surgery. And also the rate of corneal flap complications were not different between treated and control eyes after SBK. Silicone hydrogel contact lenses played a positive role in accelerating corneal epithelial healing, enhancing tear film stability and reducing discomfort of patients in the early stage after SBK.

Incidence of Intraocular Pressure Elevation following Intravitreal Ranibizumab (Lucentis) for Age-related Macular Degeneration.

PubMed

Reis, Gustavo Msm; Grigg, John; Chua, Brian; Lee, Anne; Lim, Ridia; Higgins, Ralph; Martins, Alessandra; Goldberg, Ivan; Clement, Colin I

2017-01-01

The aim of this article is to evaluate the rate of patients developing sustained elevated intraocular pressure (IOP) after ranibizumab (Lucentis) intravitreal (IVT) injections. This is a retrospective study. Charts of 192 consecutive patients receiving Lucentis for age-related macular degeneration (AMD) were retrospectively reviewed. We enrolled patients with at least two IOP measurements between injections. Elevated IOP was defined as >21 mm Hg with an increase of at least 20% from baseline. Noninjected contralateral eyes of the same patient cohort were used as control. Primary outcome was defined as elevated IOP. Secondary outcomes were presence and type of glaucoma, number of injections, and time to IOP elevation. Elevated IOP occurred at a significantly higher rate in eyes receiving IVT ranibizumab (7.47%; n = 9) compared with control (0.93%; n = 1). Patients with preexisting glaucoma or ocular hypertension (OHT) were more likely to develop elevated IOP after IVT ranibizumab injection. Intravitreal ranibizumab injections are associated with sustained IOP elevation in some eyes. Reis GMSM, Grigg J, Chua B, Lee A, Lim R, Higgins R, Martins A, Goldberg I, Clement CI. The Incidence of Intraocular Pressure Elevation following Intravitreal Ranibizumab (Lucentis) for Age-related Macular Degeneration. J Curr Glaucoma Pract 2017;11(1):3-7.

Neural mechanisms of attention become more specialised during infancy: Insights from combined eye tracking and EEG.

PubMed

Kulke, Louisa; Atkinson, Janette; Braddick, Oliver

2017-03-01

The Fixation Shift Paradigm (FSP) measures infants' ability to shift gaze from a central fixation stimulus to a peripheral target (e.g. Hood & Atkinson, 1993: Infant Behavior and Development, 16(4), 405-422). Cortical maturation has been suggested as crucial for the developing ability to shift attention. This study investigated the development of neural mechanisms by combining EEG with simultaneous eye tracking during FSP testing, in typically developing infants aged between 1 and 8 months. The most prominent neural response was a frontal positivity which occurred only in the hemisphere contralateral to the target in the youngest infants but became more ipsilateral with age. This changing lateralisation was associated with improving ability to shift attention (decreasing saccade latencies and fewer 'sticky fixations'-failures to disengage attention from the central target). These findings suggest that the lateralisation of neural responses develops during infancy, possibly due to developing intracortical connections, allowing infants to shift attention more efficiently. Successful use of combined simultaneous remote eye tracking and EEG to measure infant attention shifts. Neural responses involved in attention shifts change in the first year of life. The lateralisation of EEG responses changes with age in the first year of life. Frontal cortex is involved in attention shifts from around 2 months of age. © 2016 Wiley Periodicals, Inc.

Successful gene therapy in the RPGRIP1-deficient dog: a large model of cone-rod dystrophy.

PubMed

Lhériteau, Elsa; Petit, Lolita; Weber, Michel; Le Meur, Guylène; Deschamps, Jack-Yves; Libeau, Lyse; Mendes-Madeira, Alexandra; Guihal, Caroline; François, Achille; Guyon, Richard; Provost, Nathalie; Lemoine, Françoise; Papal, Samantha; El-Amraoui, Aziz; Colle, Marie-Anne; Moullier, Philippe; Rolling, Fabienne

2014-02-01

For the development of new therapies, proof-of-concept studies in large animal models that share clinical features with their human counterparts represent a pivotal step. For inherited retinal dystrophies primarily involving photoreceptor cells, the efficacy of gene therapy has been demonstrated in canine models of stationary cone dystrophies and progressive rod-cone dystrophies but not in large models of progressive cone-rod dystrophies, another important cause of blindness. To address the last issue, we evaluated gene therapy in the retinitis pigmentosa GTPase regulator interacting protein 1 (RPGRIP1)-deficient dog, a model exhibiting a severe cone-rod dystrophy similar to that seen in humans. Subretinal injection of AAV5 (n = 5) or AAV8 (n = 2) encoding the canine Rpgrip1 improved photoreceptor survival in transduced areas of treated retinas. Cone function was significantly and stably rescued in all treated eyes (18-72% of those recorded in normal eyes) up to 24 months postinjection. Rod function was also preserved (22-29% of baseline function) in four of the five treated dogs up to 24 months postinjection. No detectable rod function remained in untreated contralateral eyes. More importantly, treatment preserved bright- and dim-light vision. Efficacy of gene therapy in this large animal model of cone-rod dystrophy provides great promise for human treatment.

A Single Intravitreal Injection of Ranibizumab Provides No Neuroprotection in a Nonhuman Primate Model of Moderate-to-Severe Nonarteritic Anterior Ischemic Optic Neuropathy

PubMed Central

Miller, Neil R.; Johnson, Mary A.; Nolan, Theresa; Guo, Yan; Bernstein, Steven L.

2015-01-01

Purpose Ranibizumab, a vascular endothelial growth factor-antagonist, is said to be neuroprotective when injected intravitreally in patients with nonarteritic anterior ischemic optic neuropathy (NAION). We evaluated the efficacy of a single intravitreal (IVT) injection of ranibizumab in a nonhuman primate model of NAION (pNAION). Methods We induced pNAION in one eye of four adult male rhesus monkeys using a laser-activated rose Bengal induction method. We then immediately injected the eye with either ranibizumab or normal saline (NS) intravitreally. We performed a clinical assessment, optical coherence tomography, electrophysiological testing, fundus photography, and fluorescein angiography in three of the animals (one animal developed significant retinal hemorrhages and, therefore, could not be analyzed completely) prior to induction, 1 day and 1, 2, and 4 weeks thereafter. Following the 4-week analysis of the first eye, we induced pNAION in the contralateral eye and then injected either ranibizumab or NS, whichever substance had not been injected in the first eye. We euthanized all animals 5 to 12 weeks after the final assessment of the second eye and performed both immunohistochemical and light and electron microscopic analyses of the retina and optic nerves of both eyes. Results A single IVT dose of ranibizumab administered immediately after induction of pNAION resulted in no significant reduction of clinical, electrophysiological, or histologic damage compared with vehicle-injected eyes. Conclusions A single IVT dose of ranibizumab is not neuroprotective when administered immediately after induction of pNAION. PMID:26624498

Generalized seizures and transient contralateral hemiparesis following retrobulbar anesthesia: a case report.

PubMed

Dettoraki, Maria; Dimitropoulou, Chrisafoula; Nomikarios, Nikolaos; Moschos, Marilita M; Brοuzas, Dimitrios

2015-07-28

Retrobulbar block is a local anesthetic technique widely used for intraocular surgery. Although retrobulbar anesthesia is considered to be relatively safe, a number of serious adverse events have been reported. To our knowledge, immediate onset of generalized seizures with contralateral hemiparesis after retrobulbar anesthesia has not been reported. A 62-year-old Caucasian healthy male with a right eye retinal detachment was admitted for pars plana vitrectomy. During retrobulbar anesthesia with ropivacaine and before needle withdrawal, the patient developed twitching of the face which rapidly progressed to generalized tonic-clonic seizures. Arterial oxygen saturation decreased to 75 %. Chin lift was performed and 100 % oxygen was administrated via face mask, which increased saturation to 99 %. Midazolam 2 mg was administrated intravenously to control seizures. After cessation of seizures, left-sided hemiparesis was evident. Brain computed tomography and electroencephalogram were normal 3 h later. The patient underwent pars plana vitrectomy under general anesthesia 4 days later. Serious complications of local anesthesia for ophthalmic surgery are uncommon. We present a case in which generalized tonic-clonic seizures developed during retrobulbar anesthesia, followed by transient contralateral hemiparesis. The early onset of seizures indicated intra-arterial injection of the anesthetic. Our case suggested the need for close monitoring during the performance of retrobulbar anesthesia and the presence of well-trained personnel for early recognition and immediate management of the complications.

Adolescents and female patients are at increased risk for contralateral anterior cruciate ligament reconstruction: a cohort study from the Swedish National Knee Ligament Register based on 17,682 patients.

PubMed

Snaebjörnsson, Thorkell; Hamrin Senorski, Eric; Sundemo, David; Svantesson, Eleonor; Westin, Olof; Musahl, Volker; Alentorn-Geli, Eduard; Samuelsson, Kristian

2017-12-01

The impact of different surgical techniques in index ACL reconstruction for patients undergoing contralateral ACL reconstruction was investigated. The study was based on data from the Swedish National Knee Ligament Register. Patients undergoing index ACL reconstruction and subsequent contralateral ACL reconstruction using hamstring graft under the study period were included. The following variables were evaluated: age at index surgery, gender, concomitant meniscal or cartilage injury registered at index injury, transportal femoral bone tunnel drilling and transtibial femoral bone tunnel drilling. The end-point of primary contralateral ACL surgery was analysed as well as the time-to-event outcomes using survivorship methods including Kaplan-Meier estimation and Cox proportional hazards regression models. A total of 17,682 patients [n = 10,013 males (56.6%) and 7669 females (43.4%)] undergoing primary ACL reconstruction from 1 January 2005 through 31 December 2014 were included in the study. A total of 526 (3.0%) patients [n = 260 males (49.4%) and 266 females (50.6%)] underwent primary contralateral ACL reconstruction after index ACL reconstruction during the study period. Females had a 33.7% greater risk of contralateral ACL surgery [HR 1.337 (95% CI 1.127-1.586); (P = 0 0.001)]. The youngest age group (13-15 years) showed an increased risk of contralateral ACL surgery compared with the reference (36-49) age group [HR 2.771 (95% CI 1.456-5.272); (P = 0.002)]. Decreased risk of contralateral ACL surgery was seen amongst patients with concomitant cartilage injury at index surgery [HR 0.765 (95% CI 0.623-0.939); (P = 0.010)]. No differences in terms of the risk of contralateral ACL surgery were found between anatomic and non-anatomic techniques of primary single-bundle ACL reconstruction, comparing transportal anatomic technique to transtibial non-anatomic, anatomic and partial-anatomic. Age and gender were identified as risk factors for contralateral ACL reconstruction; hence young individuals and females were more prone to undergo contralateral ACL reconstruction. Patients with concomitant cartilage injury at index ACL reconstruction had lower risk for contralateral ACL reconstruction. No significant differences between various ACL reconstruction techniques could be related to increased risk of contralateral ACL reconstruction. Retrospective Cohort Study, Level III.

Retinal Vascular Fractal Dimension, Childhood IQ, and Cognitive Ability in Old Age: The Lothian Birth Cohort Study 1936

PubMed Central

Taylor, Adele M.; MacGillivray, Thomas J.; Henderson, Ross D.; Ilzina, Lasma; Dhillon, Baljean; Starr, John M.; Deary, Ian J.

2015-01-01

Purpose Cerebral microvascular disease is associated with dementia. Differences in the topography of the retinal vascular network may be a marker for cerebrovascular disease. The association between cerebral microvascular state and non-pathological cognitive ageing is less clear, particularly because studies are rarely able to adjust for pre-morbid cognitive ability level. We measured retinal vascular fractal dimension (D f) as a potential marker of cerebral microvascular disease. We examined the extent to which it contributes to differences in non-pathological cognitive ability in old age, after adjusting for childhood mental ability. Methods Participants from the Lothian Birth Cohort 1936 Study (LBC1936) had cognitive ability assessments and retinal photographs taken of both eyes aged around 73 years (n = 648). IQ scores were available from childhood. Retinal vascular D f was calculated with monofractal and multifractal analysis, performed on custom-written software. Multiple regression models were applied to determine associations between retinal vascular D f and general cognitive ability (g), processing speed, and memory. Results Only three out of 24 comparisons (two eyes × four D f parameters × three cognitive measures) were found to be significant. This is little more than would be expected by chance. No single association was verified by an equivalent association in the contralateral eye. Conclusions The results show little evidence that fractal measures of retinal vascular differences are associated with non-pathological cognitive ageing. PMID:25816017

Visual area of the lateral suprasylvian gyrus (Clare—Bishop area) of the cat

PubMed Central

Hubel, David H.; Wiesel, Torsten N.

1969-01-01

On anatomical and physiological grounds a zone of cat cortex deep in the medial bank of the suprasylvian sulcus (the Clare—Bishop area) is known to receive strong visual projections both from the lateral geniculate body and area 17. We have mapped receptive fields of single cells in this area in eight cats. Active responses to visual stimuli were found over most of the medial bank of the suprasylvian sulcus extending to the depths and over to the lowest part of the lateral bank. The area is clearly topographically arranged. The first responsive cells, recorded over the lateral convexity and 2-3 mm down the medial bank, had receptive fields in the far periphery of the contralateral visual fields. The receptive fields tended to be large, but showed considerable variation in size and scatter in their positions. As the electrode advanced down the bank, fields of successively recorded cells gradually tended to move inwards, so that in the depths of the sulcus the inner borders of many of the fields reached the vertical mid line. Here the fields were smaller, though they still varied very much in size. Receptive fields were larger than in 17, 18, or 19, but otherwise were not obviously different from the complex and lower-order hypercomplex fields in those areas. No simple fields, or concentric fields of the retino-geniculate type, were seen. Cells with common receptive-field orientation were grouped together, but whether or not the grouping occurs in columns was not established. Most cells were driven independently by the two eyes. Fields in the two eyes seemed to be identical in organization. Cells dominated by the contralateral eye were much more common than ipsilaterally dominated ones, but when cells with parafoveal and peripheral fields were considered separately, the asymmetry was seen to apply mainly to cells with peripheral fields. PMID:5770897

Blindsight and Unconscious Vision: What They Teach Us about the Human Visual System

PubMed Central

Ajina, Sara; Bridge, Holly

2017-01-01

Damage to the primary visual cortex removes the major input from the eyes to the brain, causing significant visual loss as patients are unable to perceive the side of the world contralateral to the damage. Some patients, however, retain the ability to detect visual information within this blind region; this is known as blindsight. By studying the visual pathways that underlie this residual vision in patients, we can uncover additional aspects of the human visual system that likely contribute to normal visual function but cannot be revealed under physiological conditions. In this review, we discuss the residual abilities and neural activity that have been described in blindsight and the implications of these findings for understanding the intact system. PMID:27777337

Adaptive remodeling at the pedicle due to pars fracture: a finite element analysis study.

PubMed

İnceoğlu, Serkan; Mageswaran, Prasath; Modic, Michael T; Benzel, Edward C

2014-09-01

Spondylolysis is a common condition among the general population and a major cause of back pain in young athletes. This condition can be difficult to detect with plain radiography and has been reported to lead to contralateral pars fracture or pedicle fracture in the terminal stages. Interestingly, some patients with late-stage spondylolysis are observed to have radiographic or CT evidence of a sclerotic pedicle on the side contralateral to the spondylolysis. Although computational studies have shown stress elevation in the contralateral pedicle after a pars fracture, it is not known if these changes would cause sclerotic changes in the contralateral pedicle. The objective of this study was to investigate the adaptive remodeling process at the pedicle due to a contralateral spondylolysis using finite element analysis. A multiscale finite element model of a vertebra was obtained by combining a continuum model of the posterior elements with a voxel-based pedicle section. Extension loading conditions were applied with or without a fracture at the contralateral pars to analyze the stresses in the contralateral pedicle. A remodeling algorithm was used to simulate and assess density changes in the contralateral pedicle. The remodeling algorithm demonstrated an increase in bone formation around the perimeter of the contralateral pedicle with some localized loss of mass in the region of cancellous bone. The authors' results indicated that a pars fracture results in sclerotic changes in the contralateral pedicle. Such a remodeling process could increase overall bone mass. However, focal bone loss in the region of the cancellous bone of the pedicle might predispose the pedicle to microfractures. This phenomenon explains, at least in part, the origin of pedicle stress fractures in the sclerotic contralateral pedicles of patients with unilateral spondylolysis.

Preoperative ultrasonographic evaluation of the contralateral patent processus vaginalis at the level of the internal inguinal ring is useful for predicting contralateral inguinal hernias in children: a prospective analysis.

PubMed

Kaneda, H; Furuya, T; Sugito, K; Goto, S; Kawashima, H; Inoue, M; Hosoda, T; Masuko, T; Ohashi, K; Ikeda, T; Koshinaga, T; Hoshino, M; Goto, H

2015-08-01

The current study aimed to verify the usefulness of preoperative ultrasonographic evaluation of contralateral patent processus vaginalis (PPV) at the level of the internal inguinal ring. This was a prospective study of patients undergoing unilateral inguinal hernia repair at two institutions during 2010-2011. The sex, age at initial operation, birth weight, initial operation side, and the preoperative diameter of the contralateral PPV as determined using ultrasonography (US) were recorded. We analyzed the incidence of contralateral inguinal hernia, risk factors, and the usefulness of the preoperative major diameter of the contralateral PPV. The follow-up period was 36 months. All 105 patients who underwent unilateral hernia repair completed 36 months of follow-up, during which 11 patients (10.5 %) developed a contralateral hernia. The following covariates were not associated with contralateral hernia development: sex (p = 0.350), age (p = 0.185), birth weight (p = 0.939), and initial operation side (p = 0.350). The preoperative major diameter of the contralateral PPV determined using US was significantly wider among patients with a contralateral hernia than those without a contralateral hernia (p = 0.001). When the 105 patients were divided into two groups according to cut-off values of the preoperative major diameter of the contralateral PPV (wide group, >2.0 mm; narrow group, ≤2.0 mm), a significant association was observed between the preoperative major diameter of the contralateral PPV and patient outcomes (p = 0.001). We used US and confirmed the usefulness of a preoperative evaluation of the major diameter of the contralateral PPV at the level of the internal inguinal ring in pediatric patients with unilateral inguinal hernias.

Remodeling of the Connective Tissue Microarchitecture of the Lamina Cribrosa in Early Experimental Glaucoma

PubMed Central

Roberts, Michael D.; Grau, Vicente; Grimm, Jonathan; Reynaud, Juan; Bellezza, Anthony J.; Burgoyne, Claude F.; Downs, J. Crawford

2009-01-01

Purpose To characterize the trabeculated connective tissue microarchitecture of the lamina cribrosa (LC) in terms of total connective tissue volume (CTV), connective tissue volume fraction (CTVF), predominant beam orientation, and material anisotropy in monkeys with early experimental glaucoma (EG). Methods The optic nerve heads from three monkeys with unilateral EG and four bilaterally normal monkeys were three dimensionally reconstructed from tissues perfusion fixed at an intraocular pressure of 10 mm Hg. A three-dimensional segmentation algorithm was used to extract a binary, voxel-based representation of the porous LC connective tissue microstructure that was regionalized into 45 subvolumes, and the following quantities were calculated: total CTV within the LC, mean and regional CTVF, regional predominant beam orientation, and mean and regional material anisotropy. Results Regional variation within the laminar microstructure was considerable within the normal eyes of all monkeys. The laminar connective tissue was generally most dense in the central and superior regions for the paired normal eyes, and laminar beams were radially oriented at the periphery for all eyes considered. CTV increased substantially in EG eyes compared with contralateral normal eyes (82%, 44%, 45% increases; P < 0.05), but average CTVF changed little (−7%, 1%, and −2% in the EG eyes). There were more laminar beams through the thickness of the LC in the EG eyes than in the normal controls (46%, 18%, 17% increases). Conclusions The substantial increase in laminar CTV with little change in CTVF suggests that significant alterations in connective and nonconnective tissue components in the laminar region occur in the early stages of glaucomatous damage. PMID:18806292

The Deceptively Simple N170 Reflects Network Information Processing Mechanisms Involving Visual Feature Coding and Transfer Across Hemispheres.

PubMed

Ince, Robin A A; Jaworska, Katarzyna; Gross, Joachim; Panzeri, Stefano; van Rijsbergen, Nicola J; Rousselet, Guillaume A; Schyns, Philippe G

2016-08-22

A key to understanding visual cognition is to determine "where", "when", and "how" brain responses reflect the processing of the specific visual features that modulate categorization behavior-the "what". The N170 is the earliest Event-Related Potential (ERP) that preferentially responds to faces. Here, we demonstrate that a paradigmatic shift is necessary to interpret the N170 as the product of an information processing network that dynamically codes and transfers face features across hemispheres, rather than as a local stimulus-driven event. Reverse-correlation methods coupled with information-theoretic analyses revealed that visibility of the eyes influences face detection behavior. The N170 initially reflects coding of the behaviorally relevant eye contralateral to the sensor, followed by a causal communication of the other eye from the other hemisphere. These findings demonstrate that the deceptively simple N170 ERP hides a complex network information processing mechanism involving initial coding and subsequent cross-hemispheric transfer of visual features. © The Author 2016. Published by Oxford University Press.

Congenital orbital cysts of neural tissue in two dogs.

PubMed

Regnier, Alain; Raymond-Letron, Isabelle; Peiffer, Robert L

2008-01-01

A 3-month-old English Cocker Spaniel and a 6-month-old miniature poodle presented with clinical signs related to an abnormal right eye since birth. In both dogs, the right globe could not be identified and was replaced by a fluctuant intraorbital mass covered by a vascularized mucous membrane. Ultrasonography demonstrated that both masses were cystic structures markedly larger in size than the normal contralateral globes. In both cases, surgical excision revealed a multilobular cyst filling the whole orbital cavity. Histopathologic examination and immunostaining for glial fibrillary acid protein and S100 protein supported a diagnosis of neural cysts associated with ocular dysplasia. The definitive diagnosis was congenital cystic eye and microphthalmos with cyst for the Cocker Spaniel and miniature poodle, respectively. Karyotype was normal in both dogs. Congenital cystic eye and microphthalmos with cyst result from defects in early embryonic life that arise following formation of the optic vesicle and prior to closure of the optic fissure. To the authors' knowledge neither has been reported in the canine species. They should be considered in the differential diagnosis of orbital cysts in dogs.

Radiation-induced ocular injury in the dog: a histological study.

PubMed

Ching, S V; Gillette, S M; Powers, B E; Roberts, S M; Gillette, E L; Withrow, S J

1990-08-01

Radiation-induced ocular injury secondary to treatment of nasal cancer occurs in humans and animals. Dogs with nasal carcinomas were randomized to receive 36 to 67.5 Gy in fractionated doses given in 4 weeks using a 6 MV linear accelerator. Ophthalmic examinations were performed according to a predetermined protocol and eyes were removed for histologic examination when dogs were euthanatized. The eye in the radiation field exhibited greater injury than the contralateral eye with nasal areas of the globe having more severe lesions than temporal areas. Lesions occurred in all dogs and at all doses. At 1 month or less postirradiation treatment, all dogs had blepharitis, keratoconjunctivitis and corneal epithelial atrophy. Surface lesions persisted in all eyes, becoming less severe and more chronic with time. At 3-6 months postirradiation treatment, degenerative angiopathy of retinal vessels appeared with multifocal retinal hemorrhage and mild diffuse retinal degeneration which affected outer layers first and progressed inwardly with time. At 6 months postirradiation treatment, there were cataracts, fibrosis of retinal vessel walls with loss of vascular smooth muscle, retinal hemorrhage, and mild to moderate retinal degeneration. At 1 year postirradiation treatment, retinal vessels remained sclerotic, retinal hemorrhage was less frequent, and there was moderate retinal degeneration with swelling and loss of ganglion cells. By 2 years or more postirradiation treatment, optic nerve axonal degeneration secondary to retinal changes had appeared. Tapetal and choroidal atrophy were inconsistently seen. Thus, ocular lesions at the doses received developed along a relatively predictable time course and recovery was not seen. Structures of the canine eye appear sufficiently sensitive that even relatively low total doses given in small doses per fraction cause significant long-term injury.

Enhancement of vision by monocular deprivation in adult mice.

PubMed

Prusky, Glen T; Alam, Nazia M; Douglas, Robert M

2006-11-08

Plasticity of vision mediated through binocular interactions has been reported in mammals only during a "critical" period in juvenile life, wherein monocular deprivation (MD) causes an enduring loss of visual acuity (amblyopia) selectively through the deprived eye. Here, we report a different form of interocular plasticity of vision in adult mice in which MD leads to an enhancement of the optokinetic response (OKR) selectively through the nondeprived eye. Over 5 d of MD, the spatial frequency sensitivity of the OKR increased gradually, reaching a plateau of approximately 36% above pre-deprivation baseline. Eye opening initiated a gradual decline, but sensitivity was maintained above pre-deprivation baseline for 5-6 d. Enhanced function was restricted to the monocular visual field, notwithstanding the dependence of the plasticity on binocular interactions. Activity in visual cortex ipsilateral to the deprived eye was necessary for the characteristic induction of the enhancement, and activity in visual cortex contralateral to the deprived eye was necessary for its maintenance after MD. The plasticity also displayed distinct learning-like properties: Active testing experience was required to attain maximal enhancement and for enhancement to persist after MD, and the duration of enhanced sensitivity after MD was extended by increasing the length of MD, and by repeating MD. These data show that the adult mouse visual system maintains a form of experience-dependent plasticity in which the visual cortex can modulate the normal function of subcortical visual pathways.

Parietal stimulation destabilizes spatial updating across saccadic eye movements.

PubMed

Morris, Adam P; Chambers, Christopher D; Mattingley, Jason B

2007-05-22

Saccadic eye movements cause sudden and global shifts in the retinal image. Rather than causing confusion, however, eye movements expand our sense of space and detail. In macaques, a stable representation of space is embodied by neural populations in intraparietal cortex that redistribute activity with each saccade to compensate for eye displacement, but little is known about equivalent updating mechanisms in humans. We combined noninvasive cortical stimulation with a double-step saccade task to examine the contribution of two human intraparietal areas to transsaccadic spatial updating. Right hemisphere stimulation over the posterior termination of the intraparietal sulcus (IPSp) broadened and shifted the distribution of second-saccade endpoints, but only when the first-saccade was directed into the contralateral hemifield. By interleaving trials with and without cortical stimulation, we show that the shift in endpoints was caused by an enduring effect of stimulation on neural functioning (e.g., modulation of neuronal gain). By varying the onset time of stimulation, we show that the representation of space in IPSp is updated immediately after the first-saccade. In contrast, stimulation of an adjacent IPS site had no such effects on second-saccades. These experiments suggest that stimulation of IPSp distorts an eye position or displacement signal that updates the representation of space at the completion of a saccade. Such sensory-motor integration in IPSp is crucial for the ongoing control of action, and may contribute to visual stability across saccades.

Risk of contralateral avascular necrosis (AVN) after total hip arthroplasty (THA) for non-traumatic AVN.

PubMed

Goker, Berna; Block, Joel A

2006-01-01

The risk of developing bilateral disease progressing to total hip arthroplasty (THA) among patients who undergo unilateral THA for non-traumatic avascular necrosis (AVN) remains poorly understood. An analysis of the time-course to contralateral THA, as well as the effects of underlying AVN risk factors, is presented. Forty-seven consecutive patients who underwent THA for AVN were evaluated. Peri-operative and annual post-operative antero-posterior pelvis radiographs were examined for evidence of contralateral involvement. Patient age, weight, height, underlying AVN risk factor(s), date of onset of contralateral hip pain if occurred, and date of contralateral THA if performed, were recorded. Bone scan, computerized tomography and magnetic resonance imaging data were utilized when available. Twenty-one patients (46.6%) underwent contralateral THA for AVN within a median of 9 months after the initial THA (range 0-93, interquartile range 28.5 months). The median follow-up for patients without contralateral THA was 75 months (range 3-109, interquartile range 69 months). Thirty-four patients had radiographic findings of contralateral AVN at study entry; 25 were symptomatic bilaterally at entry and 7 developed contralateral symptoms within a mean time of 12 months (median 10 months, interquartile range 12 months). None of the 13 patients who were free of radiographic evidence of contralateral AVN at study entry developed evidence of AVN during the follow-up. AVN associated with glucocorticoid use was more likely to manifest as bilateral disease than either idiopathic AVN or ethanol-associated AVN (P=0.02 and P=0.03 respectively). Radiographically-evident AVN in the contralateral hip at THA is unlikely to remain asymptomatic for a prolonged period of time. Conversely, asymptomatic contralateral hips without radiographic evidence of AVN are unlikely to develop clinically significant AVN.

Retrobulbar vs peribulbar regional anesthesia techniques using bupivacaine in dogs.

PubMed

Shilo-Benjamini, Yael; Pascoe, Peter J; Maggs, David J; Hollingsworth, Steven R; Strom, Ann R; Good, Kathryn L; Thomasy, Sara M; Kass, Philip H; Wisner, Erik R

2018-05-15

To compare the effectiveness of retrobulbar anesthesia (RBA) and peribulbar anesthesia (PBA) in dogs. Six adult mixed-breed dogs (18-24 kg). In a randomized, masked, crossover trial with a 10-day washout period, each dog was sedated with intravenously administered dexmedetomidine and administered 0.5% bupivacaine:iopamidol (4:1) as RBA (2 mL via a ventrolateral site) or PBA (5 mL divided equally between ventrolateral and dorsomedial sites). The contralateral eye acted as control. Injectate distribution was evaluated by computed tomography. Following intramuscularly administered atipamezole, corneal and periocular skin sensation, intraocular pressure (IOP), and ocular reflexes, and appearance were evaluated for 24 hours. Comparisons were performed with mixed-effects linear regression (IOP) or the exact Wilcoxon signed rank test (scores). Significance was set at P ≤ .05. Injectate distribution was intraconal in 2/6 RBA- and 4/6 PBA-injected eyes. Eyes undergoing PBA had significantly reduced lateral, ventral, and dorsal periocular skin sensation for 2-3 hours, and significantly reduced corneal sensitivity for 4 hours, relative to control eyes. Chemosis and exophthalmos occurred in 33%-40% of eyes undergoing RBA and 83%-100% eyes undergoing PBA but resolved within 14 hours. Anterior uveitis developed in 2/6 and 1/6 eyes of RBA and PBA, respectively, of them corneal ulcer developed in one eye of each treatment. Both resolved 1-3 days following medical treatment. Peribulbar injection produced notable anesthesia more reliably than did retrobulbar injection. Both techniques may produce adverse effects, although the uveitis/ulcer could have resulted from the contrast agent used. © 2018 American College of Veterinary Ophthalmologists.

Comparison of in vitro eye irritation potential by bovine corneal opacity and permeability (BCOP) assay to erythema scores in human eye sting test of surfactant-based formulations.

PubMed

Cater, Kathleen C; Harbell, John W

2008-01-01

The bovine corneal opacity and permeability (BCOP) assay can be used to predict relative eye irritation potential of surfactant-based personal care formulations relative to a corporate benchmark. The human eye sting test is typically used to evaluate product claims of no tears/no stinging for children's bath products. A preliminary investigation was conducted to test a hypothesis that the BCOP assay could be used as a prediction model for relative ranking of human eye irritation responses under conditions of a standard human eye sting test to surfactant-based formulations. BCOP assays and human eye sting tests were conducted on 4 commercial and 1 prototype body wash (BW) developed specifically for children or as mild bath products. In the human eye sting test, 10 mul of a 10% dosing solution is instilled into one eye of each panelist (n = 20), and the contralateral eye is dosed with sterile water as a control. Bulbar conjunctival erythema responses of each eye are graded at 30 seconds by an ophthalmologist. The BCOP assay permeability values (optical density at 490 nm [OD(490)]) for the 5 BWs ranged from 0.438 to 1.252 (i.e., least to most irritating). By comparison, the number of panelists exhibiting erythema responses (mild to moderately pink) ranged from 3 of 20 panelists for the least irritating BW to 10 of 20 panelists for the most irritating BW tested. The relative ranking of eye irritation potential of the 5 BWs in the BCOP assay compares favorably with the relative ranking of the BWs in the human eye sting test. Based on these findings, the permeability endpoint of the BCOP assay, as described for surfactant-based formulations, showed promise as a prediction model for relative ranking of conjunctival erythema responses in the human eye. Consequently, screening of prototype formulations in the BCOP assay would allow for formula optimization of mild bath products prior to investment in a human eye sting test.

Laser treatment in patients with bilateral large drusen: the complications of age-related macular degeneration prevention trial.

PubMed

2006-11-01

To evaluate the efficacy and safety of low-intensity laser treatment in the prevention of visual acuity (VA) loss among participants with bilateral large drusen. Multicenter randomized clinical trial. One eye of each participant was assigned to treatment, and the contralateral eye was assigned to observation. A total of 1052 participants who had > or =10 large (>125 microm) drusen and VA> or =20/40 in each eye enrolled through 22 clinical centers. The initial laser treatment protocol specified 60 barely visible burns applied in a grid pattern within an annulus between 1500 and 2500 mum from the foveal center. At 12 months, eyes assigned to treatment that had sufficient drusen remaining were retreated with 30 burns by targeting drusen within an annulus between 1000 and 2000 mum from the foveal center. Proportion of eyes at 5 years with loss of > or =3 lines of VA from baseline. Secondary outcome measures included the development of choroidal neovascularization or geographic atrophy (GA), change in contrast threshold, change in critical print size, and incidence of ocular adverse events. At 5 years, 188 (20.5%) treated eyes and 188 (20.5%) observed eyes had VA scores > or = 3 lines worse than at the initial visit (P = 1.00). Cumulative 5-year incidence rates for treated and observed eyes were 13.3% and 13.3% (P = 0.95) for choroidal neovascularization and 7.4% and 7.8% (P = 0.64) for GA, respectively. The contrast threshold doubled in 23.9% of treated eyes and in 20.5% of observed eyes (P = 0.40). The critical print size doubled in 29.6% of treated eyes and in 28.4% of observed eyes (P = 0.70). Seven treated eyes and 14 observed eyes had an adverse event of a > or =6-line loss in VA in the absence of late age-related macular degeneration or cataract. As applied in the Complications of Age-Related Macular Degeneration Prevention Trial, low-intensity laser treatment did not demonstrate a clinically significant benefit for vision in eyes of people with bilateral large drusen.

Contralateral comparison of wavefront-guided LASIK surgery with iris recognition versus without iris recognition using the MEL80 Excimer laser system.

PubMed

Wu, Fang; Yang, Yabo; Dougherty, Paul J

2009-05-01

To compare outcomes in wavefront-guided LASIK performed with iris recognition software versus without iris recognition software in different eyes of the same patient. A randomised, prospective study of 104 myopic eyes of 52 patients undergoing LASIK surgery with the MEL80 excimer laser system was performed. Iris recognition software was used in one eye of each patient (study group) and not used in the other eye (control group). Higher order aberrations (HOAs), contrast sensitivity, uncorrected vision (UCV), visual acuity (VA) and corneal topography were measured and recorded pre-operatively and at one month and three months post-operatively for each eye. The mean post-operative sphere and cylinder between groups was similar, however the post-operative angles of error (AE) by refraction were significantly smaller in the study group compared to the control group both in arithmetic and absolute means (p = 0.03, p = 0.01). The mean logMAR UCV was significantly better in the study group than in the control group at one month (p = 0.01). The mean logMAR VA was significantly better in the study group than in control group at both one and three months (p = 0.01, p = 0.03). In addition, mean trefoil, total third-order aberration, total fourth-order aberration and the total scotopic root-mean-square (RMS) HOAs were significantly less in the study group than those in the control group at the third (p = 0.01, p = 0.05, p = 0.04, p = 0.02). By three months, the contrast sensitivity had recovered in both groups but the study group performed better at 2.6, 4.2 and 6.6 cpd (cycles per degree) than the control group (p = 0.01, p < 0.01, p = 0.01). LASIK performed with iris recognition results in better VA, lower mean higher-order aberrations, lower refractive post-operative angles of error and better contrast sensitivity at three months post-operatively than LASIK performed without iris recognition.

An Individualized 3-Dimensional Designed and Printed Conformer After Dermis Fat Grafting for Complex Sockets.

PubMed

Mourits, Daphne L; Remmers, Jelmer S; Tan, Stevie H; Moll, Annette C; Hartong, Dyonne T

2018-04-03

To introduce a novel technique to design individually customized conformers for postenucleation sockets with dermis fat implants. We use a 3-dimensional scan of the frontal face/orbit and eyelid contour to design an individualized conformer. This polymethylmetacrylate printed conformer is adapted to patients' socket, palpebral fissures, horizontal eyelid aperture, curvature of the eyelids, and mean diameter of patients' contralateral eye. Sutures through holes in the inferior part of the conformer and in the extension can be placed to fixate the conformer and anchor fornix deepening sutures. A correct fitting conformer can be printed and attached to the socket and eyelids. The shape of this conformer can be used subsequently postsurgically to design the ocular prosthesis. Presurgical planning is important to anticipate for a functional socket to adequately fit an artificial eye. The presented technique using 3-dimensional imaging, designing, and printing promises to prevent conformer extrusion and forniceal shortening.

Evolution of TUNEL-labeling in the rat lens after in vivo exposure to just above threshold dose UVB.

PubMed

Kronschläger, Martin; Yu, Zhaohua; Talebizadeh, Nooshin; Meyer, Linda M; Hallböök, Finn; Söderberg, Per G

2013-08-01

To quantitatively analyse the evolution of TUNEL-labeling, after in vivo exposure to UVB. Altogether, 16 Sprague Dawley rats were unilaterally exposed in vivo for 15 min to close to threshold dose, 5 kJ/m(2), of ultraviolet radiation in the 300 nm wavelength region. Animals were sacrificed in groups of 4 at 1, 5, 24 and 120 h after exposure. For each animal, both eye globes were removed and frozen. The frozen eye was cryo-sectioned in 10 µm thick midsagittal sections. From each globe, three midsagittal sections with at least five sections interval in between were mounted on a microscope slide. Sections were TUNEL-labeled and counter stained with DAPI. For quantification of apoptosis, a fluorescence microscope was used. In sections with a continuous epithelial cell surface, the number of lens epithelial cell nuclei and the number of TUNEL-positive epithelial cell nuclei was counted. The total number of TUNEL-positive epithelial cell nuclei for all three sections of one lens in relation to the total number of epithelial cell nuclei for all three sections of the same lens was compared between exposed and contralateral not exposed lens for each animal. The relative difference of the fraction of TUNEL-positive nuclei between exposed and contralateral not exposed lens increased gradually, peaked in the time interval 5-120 h after exposure, and then declined. Close to threshold dose of UVB induces TUNEL-labeling that peaks in the time window 5-120 h after exposure to UVB.

In vivo biometry in the mouse eye with low coherence interferometry.

PubMed

Schmucker, Christine; Schaeffel, Frank

2004-01-01

A major drawback of the mouse model of myopia is that the ocular dimensions cannot be measured in vivo, and that histological techniques post-mortem suffer from limited resolution. We have tested the potential of a newly developed technique, optical low coherence interferometry (OLCI), adapted for short measurement distances by Meditec, Carl Zeiss, Jena, Germany (the "ACMaster"). Using this technique, ocular biometry was performed in mice with normal vision and after deprivation of form vision. Axial eye length, corneal thickness and anterior chamber depth were measured in 23 mice, aged 25-53 days, and standard deviations from repeated measurements in the same eyes, as well as intra-individual and inter-individual variability were determined in different age groups. The data were compared to those from a preceding study in which biometrical data were obtained from frozen sections [Vision Res. 44 (2004) 1857]. Refractions were measured by automated infrared photorefraction. Mice had either normal visual exposure or were monocularly deprived of form vision for 14 days. Using OLCI, axial length could be determined with an average standard deviation of 8.0 +/- 2.9 microm, corneal thickness with 3.5 +/- 2.1 microm, and anterior chamber depth with 10.6 +/- 12.3 microm. Neither axial length, nor corneal thickness, nor anterior chamber depth were significantly different in left and right eyes of individual mice that had normal visual experience (mean absolute difference between axial lengths: 17 +/- 18 microm, between corneal thickness 5.1 +/- 4.8 microm, and between anterior chamber depths 16.7 +/- 14.8 microm). Compared to the variability that was previously found in frozen sections, the variability of axial length measurements with OLCI was 2.7 times less. After two weeks of form deprivation, OLCI revealed a significant axial elongation in the occluded eyes, compared to the contralateral fellow eyes (+38 +/- 36 microm or 1.16%, p = 0.045, n = 7, paired t-test). In this sample, no accompanying myopic shift was observed in the occluded eyes but this observation is not unexpected given the inherently variable responses of mouse eye growth to visual deprivation. OLCI had sufficient resolution in living mice to detect axial length changes in vivo that were equivalent to a dioptric change of 2 D. Using this technique, it was confirmed that mouse eyes respond to form deprivation by axial elongation, similar to the eyes of other animal models. The lack of a myopic shift in this sample, despite the axial elongation, demonstrates that biometric data are particularly important when the mouse eye is used as a model to study myopia.

Wavefront-guided versus wavefront-optimized laser in situ keratomileusis: contralateral comparative study.

PubMed

Padmanabhan, Prema; Mrochen, Michael; Basuthkar, Subam; Viswanathan, Deepa; Joseph, Roy

2008-03-01

To compare the outcomes of wavefront-guided and wavefront-optimized treatment in fellow eyes of patients having laser in situ keratomileusis (LASIK) for myopia. Medical and Vision Research Foundation, Tamil Nadu, India. This prospective comparative study comprised 27 patients who had wavefront-guided LASIK in 1 eye and wavefront-optimized LASIK in the fellow eye. The Hansatome (Bausch & Lomb) was used to create a superior-hinged flap and the Allegretto laser (WaveLight Laser Technologie AG), for photoablation. The Allegretto wave analyzer was used to measure ocular wavefront aberrations and the Functional Acuity Contrast Test chart, to measure contrast sensitivity before and 1 month after LASIK. The refractive and visual outcomes and the changes in aberrations and contrast sensitivity were compared between the 2 treatment modalities. One month postoperatively, 92% of eyes in the wavefront-guided group and 85% in the wavefront-optimized group had uncorrected visual acuity of 20/20 or better; 93% and 89%, respectively, had a postoperative spherical equivalent refraction of +/-0.50 diopter. The differences between groups were not statistically significant. Wavefront-guided LASIK induced less change in 18 of 22 higher-order Zernike terms than wavefront-optimized LASIK, with the change in positive spherical aberration the only statistically significant one (P= .01). Contrast sensitivity improved at the low and middle spatial frequencies (not statistically significant) and worsened significantly at high spatial frequencies after wavefront-guided LASIK; there was a statistically significant worsening at all spatial frequencies after wavefront-optimized LASIK. Although both wavefront-guided and wavefront-optimized LASIK gave excellent refractive correction results, the former induced less higher-order aberrations and was associated with better contrast sensitivity.

Reduction in spontaneous firing of mouse excitatory layer 4 cortical neurons following visual classical conditioning

NASA Astrophysics Data System (ADS)

Bekisz, Marek; Shendye, Ninad; Raciborska, Ida; Wróbel, Andrzej; Waleszczyk, Wioletta J.

2017-08-01

The process of learning induces plastic changes in neuronal network of the brain. Our earlier studies on mice showed that classical conditioning in which monocular visual stimulation was paired with an electric shock to the tail enhanced GABA immunoreactivity within layer 4 of the monocular part of the primary visual cortex (V1), contralaterally to the stimulated eye. In the present experiment we investigated whether the same classical conditioning paradigm induces changes of neuronal excitability in this cortical area. Two experimental groups were used: mice that underwent 7-day visual classical conditioning and controls. Patch-clamp whole-cell recordings were performed from ex vivo slices of mouse V1. The slices were perfused with the modified artificial cerebrospinal fluid, the composition of which better mimics the brain interstitial fluid in situ and induces spontaneous activity. The neuronal excitability was characterized by measuring the frequency of spontaneous action potentials. We found that layer 4 star pyramidal cells located in the monocular representation of the "trained" eye in V1 had lower frequency of spontaneous activity in comparison with neurons from the same cortical region of control animals. Weaker spontaneous firing indicates decreased general excitability of star pyramidal neurons within layer 4 of the monocular representation of the "trained" eye in V1. Such effect could result from enhanced inhibitory processes accompanying learning in this cortical area.

Successful Gene Therapy in the RPGRIP1-deficient Dog: a Large Model of Cone–Rod Dystrophy

PubMed Central

Lhériteau, Elsa; Petit, Lolita; Weber, Michel; Le Meur, Guylène; Deschamps, Jack-Yves; Libeau, Lyse; Mendes-Madeira, Alexandra; Guihal, Caroline; François, Achille; Guyon, Richard; Provost, Nathalie; Lemoine, Françoise; Papal, Samantha; El-Amraoui, Aziz; Colle, Marie-Anne; Moullier, Philippe; Rolling, Fabienne

2014-01-01

For the development of new therapies, proof-of-concept studies in large animal models that share clinical features with their human counterparts represent a pivotal step. For inherited retinal dystrophies primarily involving photoreceptor cells, the efficacy of gene therapy has been demonstrated in canine models of stationary cone dystrophies and progressive rod–cone dystrophies but not in large models of progressive cone–rod dystrophies, another important cause of blindness. To address the last issue, we evaluated gene therapy in the retinitis pigmentosa GTPase regulator interacting protein 1 (RPGRIP1)-deficient dog, a model exhibiting a severe cone–rod dystrophy similar to that seen in humans. Subretinal injection of AAV5 (n = 5) or AAV8 (n = 2) encoding the canine Rpgrip1 improved photoreceptor survival in transduced areas of treated retinas. Cone function was significantly and stably rescued in all treated eyes (18–72% of those recorded in normal eyes) up to 24 months postinjection. Rod function was also preserved (22–29% of baseline function) in four of the five treated dogs up to 24 months postinjection. No detectable rod function remained in untreated contralateral eyes. More importantly, treatment preserved bright- and dim-light vision. Efficacy of gene therapy in this large animal model of cone–rod dystrophy provides great promise for human treatment. PMID:24091916

Alterations in molecular pathways in the retina of early experimental glaucoma eyes

PubMed Central

Cao, Li; Wang, Lin; Cull, Grant; Zhou, An

2015-01-01

Glaucoma is a multifactorial, neurodegenerative disease. The molecular mechanisms that underlie the pathophysiological changes in glaucomatous eyes, especially at the early stage of the disease, are poorly understood. Here, we report the findings from a quantitative proteomic analysis of retinas from experimental glaucoma (EG) eyes. An early stage of EG was modeled on unilateral eyes of five nonhuman primates (NHP) by laser treatment-induced elevation of intraocular pressure (IOP). Retinal proteins were extracted from individual EG eyes and their contralateral control eyes of the same animals, respectively, and analyzed by quantitative mass spectrometry (MS). As a result, a total, 475 retinal proteins were confidently identified and quantified. Results of bioinformatic analysis of proteins that showed an increase in the EG eyes suggested changes in apoptosis, DNA damage, immune response, cytoskeleton rearrangement and cell adhesion processes. Interestingly, hemoglobin subunit alpha (HBA) and Ras related C3 botulinum toxin substrate 1 (Rac1) were among the increased proteins. Results of molecular modeling of HBA- and Rac1-associated signaling network implicated the involvement of Mitogen-Activated Protein Kinase (MAPK) pathway in the EG, through which Rac1 may exert a regulatory role on HBA. This is the first observation of this potentially novel signaling network in the NHP retina and in EG. Results of Western blot analyses for Rac1, HBA and a selected MAPK pathway protein indicated synergistic changes in all three proteins in the EG eyes. Further, results of hierarchical cluster analysis of proteomes of control eyes revealed a clear age-proteome relationship, and such relationship appeared disrupted in the EG eyes. In conclusion, our results suggested an increased presence of a potentially novel signaling network at the early stage of glaucoma, and age might be one of the determinant factors in retinal proteomic characteristics under normal conditions. PMID:26069528

Short-Term Moderately Elevated Intraocular Pressure Is Associated With Elevated Scotopic Electroretinogram Responses

PubMed Central

Choh, Vivian; Gurdita, Akshay; Tan, Bingyao; Prasad, Ratna C.; Bizheva, Kostadinka; Joos, Karen M.

2016-01-01

Purpose Moderately elevated intraocular pressure (IOP) is a risk factor for open-angle glaucoma. Some patients suffer glaucoma despite clinically measured normal IOPs. Fluctuations in IOP may have a significant role since IOPs are higher during sleep and inversion activities. Controlled transient elevations of IOPs in rats over time lead to optic nerve structural changes that are similar to the early changes observed in constant chronic models of glaucoma. Because early intervention decreases glaucoma progression, this study was done to determine if early physiological changes to the retina could be detected with noninvasive electrophysiological and optical imaging tests during moderately elevated IOP. Methods Intraocular pressures were raised to moderately high levels (35 mm Hg) in one eye of Sprague-Dawley rats while the other (control) eye was untreated. One group of rats underwent scotopic threshold response (STR) and electroretinogram (ERG) testing, while another 3 groups underwent optical coherence tomography (OCT) imaging, Western blot, or histologic evaluation. Results The amplitudes of the STR and ERG responses in eyes with moderately elevated IOPs were enhanced compared to the values before IOP elevation, and compared to untreated contralateral eyes. Structural changes to the optic nerve also occurred during IOP elevation. Conclusions Although ischemic IOP elevations are well-known to globally reduce components of the scotopic ERG, acute elevation in rats to levels often observed in untreated glaucoma patients caused an increase in these parameters. Further exploration of these phenomena may be helpful in better understanding the mechanisms mediating early retinal changes during fluctuating or chronically elevated IOP. PMID:27100161

Development of Experimental Myopia in Chicks in a Natural Environment

PubMed Central

Stone, Richard A.; Cohen, Yuval; McGlinn, Alice M.; Davison, Sherrill; Casavant, Susan; Shaffer, James; Khurana, Tejvir S.; Pardue, Machelle T.; Iuvone, P. Michael

2016-01-01

Purpose The hypothesis that outdoor exposure might protect against myopia has generated much interest, although available data find only modest clinical efficacy. We tested the effect of outdoor rearing on form-deprivation myopia in chicks, a myopia model markedly inhibited by high-intensity indoor laboratory lighting. Methods Unilaterally goggled cohorts of White Leghorn chicks were maintained in a species-appropriate, outdoor rural setting during daylight hours to the extent permitted by weather. Control chicks were reared indoors with incandescent lighting. Besides ocular refraction and ultrasound, we determined dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) content in retina and vitreous and measured mRNA expression levels of selected clock and circadian rhythm-related genes in the retina/RPE. Results Myopia developed in the goggled eyes of all cohorts. Whereas outdoor rearing lessened myopia by 44% at 4 days, a protective effect was no longer evident at 11 days. Outdoor rearing had no consistent effect on retinal or vitreous content of dopamine or DOPAC. Conforming to prior data on form-deprivation myopia, retina and vitreous levels of DOPAC were reduced in goggled eyes. Compared with contralateral eyes, the retinal expression of clock and circadian rhythm-related genes was modestly altered in myopic eyes of chicks reared indoors or outdoors. Conclusions Outdoor rearing of chicks induces only a partial decrease of goggle-induced myopia that is not maintained, without evidence that retinal dopamine metabolism accounts for the partial myopia inhibition under these outdoor conditions. Although modest, alterations in retinal gene expression suggest that studying circadian signals might be informative for understanding refractive mechanisms. PMID:27618415

Oral Minocycline for the Treatment of Diabetic Macular Edema (DME): Results of a Phase I/II Clinical Study

PubMed Central

Cukras, Catherine A.; Petrou, Philip; Chew, Emily Y.; Meyerle, Catherine B.; Wong, Wai T.

2012-01-01

Purpose. Inflammation contributes significantly to the pathogenesis of diabetic macular edema (DME). In particular, retinal microglia demonstrate increased activation and aggregation in areas of DME. Study authors investigated the safety and potential efficacy of oral minocycline, a drug capable of inhibiting microglial activation, in the treatment of DME. Methods. A single-center, prospective, open-label phase I/II clinical trial enrolled five participants with fovea-involving DME who received oral minocycline 100 mg twice daily for 6 months. Main outcome measurements included best-corrected visual acuity (BCVA), central retinal subfield thickness (CST), and central macular volume using spectral domain optical coherence tomography (SD-OCT) and late leakage on fluorescein angiography (FA). Results. Findings indicated that the study drug was well tolerated and not associated with significant safety issues. In study eyes, mean BCVA improved continuously from baseline at 1, 2, 4, and 6 months by +1.0, +4.0, +4.0, and +5.8 letters, respectively, while mean retinal thickness (CST) on OCT decreased by −2.9%, −5.7%, −13.9, and −8.1% for the same time points. At month 6, mean area of late leakage on FA decreased by −34.4% in study eyes. Mean changes in contralateral fellow eyes also demonstrated similar trends. Improvements in outcome measures were not correlated with concurrent changes in systemic factors. Conclusions. In this pilot proof-of-concept study of DME, minocycline as primary treatment was associated with improved visual function, central macular edema, and vascular leakage, comparing favorably with historical controls from previous studies. Microglial inhibition with oral minocycline may be a promising therapeutic strategy targeting the inflammatory etiology of DME. (ClinicalTrials.gov number, NCT01120899.) PMID:22589436

Oral minocycline for the treatment of diabetic macular edema (DME): results of a phase I/II clinical study.

PubMed

Cukras, Catherine A; Petrou, Philip; Chew, Emily Y; Meyerle, Catherine B; Wong, Wai T

2012-06-22

Inflammation contributes significantly to the pathogenesis of diabetic macular edema (DME). In particular, retinal microglia demonstrate increased activation and aggregation in areas of DME. Study authors investigated the safety and potential efficacy of oral minocycline, a drug capable of inhibiting microglial activation, in the treatment of DME. A single-center, prospective, open-label phase I/II clinical trial enrolled five participants with fovea-involving DME who received oral minocycline 100 mg twice daily for 6 months. Main outcome measurements included best-corrected visual acuity (BCVA), central retinal subfield thickness (CST), and central macular volume using spectral domain optical coherence tomography (SD-OCT) and late leakage on fluorescein angiography (FA). Findings indicated that the study drug was well tolerated and not associated with significant safety issues. In study eyes, mean BCVA improved continuously from baseline at 1, 2, 4, and 6 months by +1.0, +4.0, +4.0, and +5.8 letters, respectively, while mean retinal thickness (CST) on OCT decreased by -2.9%, -5.7%, -13.9, and -8.1% for the same time points. At month 6, mean area of late leakage on FA decreased by -34.4% in study eyes. Mean changes in contralateral fellow eyes also demonstrated similar trends. Improvements in outcome measures were not correlated with concurrent changes in systemic factors. In this pilot proof-of-concept study of DME, minocycline as primary treatment was associated with improved visual function, central macular edema, and vascular leakage, comparing favorably with historical controls from previous studies. Microglial inhibition with oral minocycline may be a promising therapeutic strategy targeting the inflammatory etiology of DME. (ClinicalTrials.gov number, NCT01120899.).

Survey of the incidence of pectinate ligament dysplasia and glaucoma in the UK Leonberger population.

PubMed

Fricker, Georgina V; Smith, Kerry; Gould, David J

2016-09-01

To determine the prevalence of pectinate ligament dysplasia (PLD) in UK Leonbergers and identify cases affected by glaucoma. Also, to define the spectrum of pectinate ligament (PL) appearance in this breed and determine whether gonioscopic monitoring should be recommended. Data were compiled from 78 prospective gonioscopy examinations performed by one author (GF) and retrospective analysis of 233 UK eye scheme certificates (2009-2014). Clinical cases of glaucoma in Leonbergers diagnosed by UK veterinary ophthalmologists, where gonioscopy of the fellow eyes or histology of affected eyes had been performed, were also reviewed. In the prospective study, intraocular pressure was recorded prior to gonioscopy using a rebound tonometer. Gonioscopy was performed using a slit-lamp biomicroscope with a Koeppe goniolens. PLD was categorized according to the percentage of the iridocorneal drainage angle affected (grade 0 = <25% affected; grade 1 = 25-50% affected; grade 2 = 51-75% affected; and grade 3 = >75% affected), and the degree of narrowing of the angle was noted. Of 78 dogs examined prospectively, 64/78 (82%) were grade 0, 7/78 (9%) were grade 1, 3/78 (4%) were grade 2, and 4/78 (5%) were grade 3. A large phenotypic variation was observed. Spearman's rank correlation showed a positive correlation between age and severity of PLD (P < 0.0055). 52 (22%) of Leonbergers examined under the UK eye scheme 2009-2014 were affected by PLD. Five clinical cases of glaucoma were reviewed where gonioscopy had been performed and one where histology was performed. All individuals had grade 3 PLD with gonioscopy of the contralateral eye or severe goniodysgenesis with histological sections of the affected eye. This survey suggests the prevalence of PLD is sufficient to justify ongoing screening of Leonbergers. © 2015 American College of Veterinary Ophthalmologists.

Studies of intrastromal corneal ring segments for the correction of low to moderate myopic refractive errors.

PubMed Central

Schanzlin, D J

1999-01-01

PURPOSE: Intrastromal corneal ring segments (ICRS) were investigated for safety and reliability in the correction of low to moderate myopic refractive errors. METHODS: Initially, 74 patients with spherical equivalent refractive errors between -1.00 and -4.25 diopters (D) received the ICRS in 1 eye. After 6 months, 51 of these patients received the ICRS in the contralateral eye. The total number of eyes investigated was 125. The outcome measures were uncorrected and best-corrected visual acuity, predictability and stability of the refraction, refractive astigmatism, contrast sensitivity, and endothelial cell morphology. RESULTS: The 89 eyes with 12-month follow-up showed significant improvement with uncorrected visual acuities of 20/16 or better in 37%, 20/20 or better in 62%, and 20/40 or better in 97%. Cycloplegic refraction spherical equivalents showed that 68% of the eyes were within +/- 0.50 D and 90% within +/- 1.00 D of the intended correction. Refractive stability was present by 3 months after the surgery. Only 1 patients had a loss greater than 2 lines or 10 letters of best spectacle-corrected visual acuity, but the patient's acuity was 20/20. Refractive cylinder, contrast sensitivity, and endothelial cell morphology were not adversely affected. The ICRS was removed from the eyes of 6 patients. Three removals were prompted by glare and double images occurring at night; 3 were for nonmedical reasons. All patients returned to within +/- 1.00 D of their preoperative refractive spherical equivalent, and no patients lost more than 1 line of best corrected visual acuity by 3 months after ICRS removal. CONCLUSION: The ICRS safely and reliably corrects myopic refractive errors between -1.00 and -4.50 D. Images FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 6 FIGURE 7 FIGURE 8 FIGURE 9 FIGURE 10 FIGURE 11 FIGURE 12 PMID:10703146

[The efficacy of large spot indirect ophthalmoscopy laser alone or combined with systemic chemotherapy in retinoblastoma therapy].

PubMed

Liang, J H; Cheng, Y; Deng, X; Yu, Y Y; Li, X X

2016-10-11

Objective: To evaluate the efficacy of large spot indirect ophthalmoscopy laser alone or combined with systemic chemotherapy in the treatment of early and middle stage retinoblastoma. Methods: Retrospective series case study. Clinical data of 21 patients (22 eyes) who were diagnosed as retinoblastoma (RB) in Peking University People's Hospital from March 2009 to August 2014 were collected. Medical and family history, ocular ultrasound, orbital and cranial MRI or CT examination of RB Children were detailed recorded. Ocular examination and laser treatment were performed under general anesthesia, once every 3-4 weeks until the tumor was under control. The observation period was at least 3 months after the last treatment. The ocular examination included intraocular pressure measurement, anterior segment and fundus examination and the fundus photography with Retcam. Laser therapeutic instrument was large spot indirect ophthalmoscopy laser of 810nm wavelength. Results: Of the 21 children, 16 were male and 5 were female. The range of age was 3 to 82 months averaged 17.3 months. Among 22 eyes, four with small tumor, eight with medium tumor, and ten with large tumor. Two eyes underwent laser treatment only and 20 eyes underwent laser treatment combined with systemic chemotherapy. During the average observation period of 33.9 months, 15 tumors were treated successfully, but 7 failed. The total success rate was 68.2%. The number and success rate of small, medium and large tumor eyes were 4 (100%), 5 (62.5%) and 5 (50%), respectively. There was one case of tumor brain metastases, and the classification of contralateral eye of the child was E phase. Iris burns happened in one eye, obvious vitreous proliferation in one eye and mild vitreous hemorrhage occurred in two eyes, which did not affect the treatment of laser. However, obvious tumor hemorrhage happened in two eyes and affected laser therapy. There was no complicated cataract, iatrogenic retinal hole and tumor intravitreal implant caused by laser blasting effect. Conclusions: Indirect ophthalmoscope laser in 810-nm diode laser with large-spot alone or combined with systemic chemotherapy may be effective treatment for retinoblastoma in earlier than stage C of international classification. It is suitable for large and multiple retinoblastoma. (Chin J Ophthalmol, 2016, 52: 745-748) .

The value of preoperative 18F-FDG PET/CT for the assessing contralateral neck in head and neck cancer patients with unilateral node metastasis (N1-3).

PubMed

Joo, Y-H; Yoo, I-R; Cho, K-J; Park, J-O; Nam, I-C; Kim, C-S; Kim, S-Y; Kim, M-S

2014-12-01

The purpose of this study was to determine whether preoperative (18) F-FDG PET/CT is useful in assessing contralateral lymph node metastasis in the neck. A retrospective review of medical records was performed. Patients treated at a single institute. One hundred and fifty-seven patients whose pathology results were positive for unilateral node metastasis (N1-3) involvement and underwent preoperative (18) F-FDG PET/CT for head and neck squamous cell carcinoma (HNSCC) were reviewed. Prognostic factors and nodal SUVmax were studied to identify the risk of contralateral disease. Thirty-six (22.9%) patients had contralateral cervical lymph node metastases. The (18) F-FDG PET/CT had a sensitivity of 80% and a specificity of 96% in identifying the contralateral cervical lymph node metastases on a level-by-level basis. The median SUVmax values of the ipsilateral and contralateral lymph nodes were 3.99 ± 3.36 (range, 0-20.4) and 2.94 ± 2.04 (range, 0-8.7), respectively (P = 0.001). There was a significant difference in the median SUVmax of contralateral nodes between the benign and malignant cervical lymph nodes (2.31 ± 0.62 versus 3.28 ± 2.43, P = 0.014). The cut-off value of contralateral median SUVmax in the context of contralateral cervical metastasis was 2.5 with the sensitivity of 75% and the specificity of 94%. A median contralateral lymph node SUVmax  ≥ 2.5 was associated with 5-year disease-specific survival (P = 0.038). (18) F-FDG PET/CT median SUVmax cut-off values of contralateral lymph nodes ≥2.5 were associated with contralateral cervical lymph node metastases and 5-year disease-specific survival in HNSCC patients with unilateral metastases. © 2014 John Wiley & Sons Ltd.

A reliable unipedal stance test for the assessment of balance using a force platform.

PubMed

Ponce-González, J G; Sanchis-Moysi, J; González-Henriquez, J J; Arteaga-Ortiz, R; Calbet, J A L; Dorado, C

2014-02-01

The aim was to develop a unipedal stance test for the assessment of balance using a force platform. A single-leg balance test was conducted in 23 students (mean ± SD) age: 23 ± 3 years) in a standard position limiting the movement of the arms and non-supporting leg. Six attempts, with both the jumping (JL) and the contralateral leg (CL), were performed under 3 conditions: 1) eyes opened; 2) eyes closed; 3) eyes opened and executing a precision task. The same protocol was repeated two-week apart. The mean and the best result of the six attempts performed each day were taken as representative of balance. The speed of the centre of pressure (CP-Speed) showed excellent reliability for the "best result" analysis in all tests (ICCs 0.87-0.97), except in the test with the eyes closed performed on the CL (ICC<0.4). The CP-Speed had better reliability with the "best result" than with the "mean result" analysis (P<0.05), whilst no significant differences were observed between the JL and the CL (P=0.71 and P=0.96 for mean and best results analysis, respectively). A lower dispersion in the Bland and Altman graph was observed with the eyes opened than closed, and the dynamic test. The single-leg stance balance test proposed is a reliable method to assess balance, especially when performed in a static position, with the eyes opened and using the best result of six attempts as reference, independently of the stance leg.

Changes in rabbit corneal innervation induced by the topical application of benzalkonium chloride.

PubMed

Chen, Wensheng; Zhang, Zhenhao; Hu, Jiaoyue; Xie, Hui; Pan, Juxin; Dong, Nuo; Liu, Zuguo

2013-12-01

To investigate the effect of benzalkonium chloride (BAK) on corneal nerves. Fifty-four adult New Zealand Albino rabbits were randomly divided into 3 groups. BAK at concentrations of 0.005%, 0.01%, or 0.02% was applied once daily to 1 eye of each rabbit for 9 days. The contralateral untreated eyes were used as controls. Corneal mechanical sensitivity, aqueous tear production, tear break-up time (BUT), fluorescein, and Rose Bengal staining scores were compared with those of control values on days 3, 6, and 9. Corneal whole mounts were immunostained with a specific antitubulin βIII antibody to label nerve fibers. Epithelial superficial nerve terminal, subbasal, and stromal nerve fiber densities were quantified. The structure of the central cornea was examined by means of in vivo confocal microscopy on day 9. The topical application of BAK resulted in lower corneal sensitivity and higher Rose Bengal staining scores on day 3, whereas there were no significant changes in the BUT, Schirmer, and corneal fluorescein scores. Decreased nerve densities in superficial and subbasal layers were observed in BAK-treated eyes on days 3 and 6, respectively. The eyes treated with 0.02% BAK exhibited significantly reduced Schirmer scores, BUT, and stromal nerve fiber density, and increased fluorescein staining scores on day 9. Corneal superficial epithelial cell size was significantly larger in all BAK-treated eyes compared with that in control eyes. The topical application of BAK can quickly cause corneal hypoesthesia without tear deficiency. Changes in corneal innervation significantly correlate with BAK-induced ocular surface changes.

Ophthalmology in North America: Early Stories (1491-1801)

PubMed Central

Leffler, Christopher T; Schwartz, Stephen G; Wainsztein, Ricardo D; Pflugrath, Adam; Peterson, Eric

2017-01-01

New World plants, such as tobacco, tomato, and chili, were held to have beneficial effects on the eyes. Indigenous healers rubbed or scraped the eyes or eyelids to treat inflammation, corneal opacities, and even eye irritation from smoke. European settlers used harsh treatments, such as bleeding and blistering, when the eyes were inflamed or had loss of vision with a normal appearance (gutta serena). In New Spain, surgery for corneal opacity was performed in 1601 and cataract couching in 1611. North American physicians knew of contralateral loss of vision after trauma or surgery (sympathetic ophthalmia), which they called “sympathy.” To date, the earliest identified cataract couching by a surgeon trained in the New World was performed in 1769 by John Bartlett of Rhode Island. The American Revolution negatively affected ophthalmology, as loyalist surgeons were expelled and others were consumed with wartime activities. After the war, cataract extraction was imported to America in earnest and academic development resumed. Charles F Bartlett, the son of John, performed cataract extraction but was also a “rapacious privateer.” In 1801, a doctor in the frontier territory of Kentucky observed anticholinergic poisoning by Datura stramonium (Jimsonweed) and suggested that this agent be applied topically to dilate the pupil before cataract extraction. John Warren at Harvard preferred couching in the 1790s, but, after his son returned from European training, recommended treating angle closure glaucoma by lens extraction. Other eye procedures described or advertised in America before the 19th century included enucleation, resection of conjunctival lesions or periocular tumors, treatment of lacrimal fistula, and fitting of prosthetic eyes. PMID:28804247

An uncommon case of intermittent Pourfour du Petit Syndrome associated with acute angle-closure glaucoma successfully treated by laser iridotomy.

PubMed

Farci, Roberta; Napoli, Pietro Emanuele; Fossarello, Maurizio

2017-07-03

To describe a case of acute angle-closure glaucoma secondary to intermittent mydriasis related to Pourfour du Petit Syndrome caused by tracheal deviation. A 70-year-old Caucasian woman visited the Emergency Room of the University Eye Clinic complaining of blurring of vision and difficulty to move superior eyelid in her right eye. Examination revealed reactive mydriasis, and upper lid retraction on the right side. The rest of the ophthalmological examination was normal, and a cranial computed tomography (CT) did not identify any abnormalities. A cervical CT showed the presence of an accentuated lateral right convex deviation of the trachea, attributable to a fibrothorax. A right Pourfour du Petit syndrome was suspected. Although the mydriasis had in the meantime vanished, the patient was admitted to the Neurological Clinic. Five days later she suffered acute pain in her right eye. Ophthalmological examination of the right eye revealed conjunctival hyperemia, marked corneal edema, reduced depth of anterior chamber, permanent mydriasis. As assessed by Goldmann applanation tonometry, intraocular pressure (IOP) was 48 mm Hg. Fundus examination was normal in both eyes. Gonioscopy revealed angle closure in all quadrants. Slit lamp examination of the contralateral eye was normal; IOP was 10 mm Hg. After hypotensive medical therapy, iridotomy with YAG laser was performed. Thereafter, IOP stabilized at 12 mm Hg. This is the first report in the literature of a case of acute angle-closure glaucoma secondary to mydriasis related to Pourfour du Petit Syndrome caused by tracheal deviation.

Contralateral Masking in Bilateral Cochlear Implant Patients: A Model of Medial Olivocochlear Function Loss

PubMed Central

Aronoff, Justin M.; Padilla, Monica; Fu, Qian-Jie; Landsberger, David M.

2015-01-01

Contralateral masking is the phenomenon where a masker presented to one ear affects the ability to detect a signal in the opposite ear. For normal hearing listeners, contralateral masking results in masking patterns that are both sharper and dramatically smaller in magnitude than ipsilateral masking. The goal of this study was to investigate whether medial olivocochlear (MOC) efferents are needed for the sharpness and relatively small magnitude of the contralateral masking function. To do this, bilateral cochlear implant patients were tested because, by directly stimulating the auditory nerve, cochlear implants circumvent the effects of the MOC efferents. The results indicated that, as with normal hearing listeners, the contralateral masking function was sharper than the ipsilateral masking function. However, although there was a reduction in the magnitude of the contralateral masking function compared to the ipsilateral masking function, it was relatively modest. This is in sharp contrast to the results of normal hearing listeners where the magnitude of the contralateral masking function is greatly reduced. These results suggest that MOC function may not play a large role in the sharpness of the contralateral masking function but may play a considerable role in the magnitude of the contralateral masking function. PMID:25798581

Visual system plasticity in mammals: the story of monocular enucleation-induced vision loss

PubMed Central

Nys, Julie; Scheyltjens, Isabelle; Arckens, Lutgarde

2015-01-01

The groundbreaking work of Hubel and Wiesel in the 1960’s on ocular dominance plasticity instigated many studies of the visual system of mammals, enriching our understanding of how the development of its structure and function depends on high quality visual input through both eyes. These studies have mainly employed lid suturing, dark rearing and eye patching applied to different species to reduce or impair visual input, and have created extensive knowledge on binocular vision. However, not all aspects and types of plasticity in the visual cortex have been covered in full detail. In that regard, a more drastic deprivation method like enucleation, leading to complete vision loss appears useful as it has more widespread effects on the afferent visual pathway and even on non-visual brain regions. One-eyed vision due to monocular enucleation (ME) profoundly affects the contralateral retinorecipient subcortical and cortical structures thereby creating a powerful means to investigate cortical plasticity phenomena in which binocular competition has no vote.In this review, we will present current knowledge about the specific application of ME as an experimental tool to study visual and cross-modal brain plasticity and compare early postnatal stages up into adulthood. The structural and physiological consequences of this type of extensive sensory loss as documented and studied in several animal species and human patients will be discussed. We will summarize how ME studies have been instrumental to our current understanding of the differentiation of sensory systems and how the structure and function of cortical circuits in mammals are shaped in response to such an extensive alteration in experience. In conclusion, we will highlight future perspectives and the clinical relevance of adding ME to the list of more longstanding deprivation models in visual system research. PMID:25972788

A multicenter randomized controlled fellow eye trial of pulse-dosed difluprednate 0.05% versus prednisolone acetate 1% in cataract surgery.

PubMed

Donnenfeld, Eric D; Holland, Edward J; Solomon, Kerry D; Fiore, Jay; Gobbo, Anthony; Prince, Jessica; Sandoval, Helga P; Shull, Emily R; Perry, Henry D

2011-10-01

To compare the effects of 2 corticosteroids on corneal thickness and visual acuity after cataract surgery. Multicenter, randomized, contralateral-eye, double-masked trial. Fifty-two patients (104 eyes) underwent bilateral phacoemulsification. The first eye randomly received difluprednate 0.05% or prednisolone acetate 1%; the fellow eye received the alternative. Before surgery, 7 doses were administered over 2 hours; 3 additional doses were given after surgery, before discharge. For the remainder of the day, corticosteroids were administered every 2 hours, then 4 times daily during week 1 and twice daily during week 2. Corneal pachymetry, visual acuity, and corneal edema were evaluated before surgery and at days 1, 15, and 30 after surgery. Endothelial cell counts were evaluated before surgery and at 30 days after surgery. Retinal thickness was evaluated before surgery and at 15 and 30 days after surgery. Corneal thickness at day 1 was 33 μm less in difluprednate-treated eyes (P = .026). More eyes were without corneal edema in the difluprednate group than in the prednisolone group at day 1 (62% vs 38%, respectively; P = .019). Uncorrected and best-corrected visual acuity at day 1 were significantly better with difluprednate than prednisolone by 0.093 logMAR lines (P = .041) and 0.134 logMAR lines (P < .001), respectively. Endothelial cell density was 195.52 cells/mm(2) higher in difluprednate-treated eyes at day 30 (P < .001). Retinal thickness at day 15 was 7.74 μm less in difluprednate-treated eyes (P = .011). In this high-dose pulsed-therapy regimen, difluprednate reduced inflammation more effectively than prednisolone acetate, resulting in more rapid return of vision. Difluprednate was superior at protecting the cornea and reducing macular thickening after cataract surgery. Copyright © 2011 Elsevier Inc. All rights reserved.

Risk factors for choroidal neovascularization and geographic atrophy in the complications of age-related macular degeneration prevention trial.

PubMed

2008-09-01

To determine risk factors for choroidal neovascularization (CNV) and of geographic atrophy (GA) in eyes with large drusen. Cohort study within a multicenter, randomized clinical trial of laser treatment for the prevention of vision loss from advanced age-related macular degeneration. One thousand fifty-two participants with 10 or more large drusen (>or=125 microm) and visual acuity of 20/40 or better in each eye. At baseline, participants provided a brief medical history. Trained readers evaluated baseline color photographs for drusen characteristics and pigmentary abnormalities. One eye of each participant was assigned to laser treatment and the contralateral eye was assigned to observation. The Complications of Age-Related Macular Degeneration Prevention Trial (CAPT) Reading Center readers identified CNV and endpoint GA from color photographs and fluorescein angiograms obtained during follow-up visits scheduled for 5 or 6 years. Estimates of relative risks (RRs) and 95% confidence intervals (CIs) were obtained from survival analyses of observed and treated eyes, considered separately and combined. Development of CNV and of endpoint GA. Choroidal neovascularization developed in 141 observed eyes and 141 treated eyes, including 57 patients affected bilaterally. Statistically significant risk factors for CNV in the multivariate model for all eyes were older age (RR, 2.81 [95% CI, 1.33-5.94] for >79 years vs. 50-59 years), cigarette smoking (RR, 1.98 [95% CI, 1.16-3.39] for current vs. never), and focal hyperpigmentation (RR, 1.84 [95% CI, 1.22-2.76] for >or=250 microm vs. none). Among eyes free of GA at baseline, endpoint GA developed in 61 observed eyes and in 58 treated eyes, including 29 patients affected bilaterally. Statistically significant risk factors for GA in the multivariate model for all eyes were older age (RR, 6.39 [95% CI, 1.64-24.9] for >79 years vs. 50-59 years), greater retinal area covered by drusen (RR, 5.10 [95% CI, 2.57-10.1] for >or=25% vs. <10%), retinal pigment epithelium (RPE) depigmentation (RR, 2.64 [95% CI, 1.26-5.53), and focal hyperpigmentation (RR, 10.4 [95% CI, 4.51-24.0] for >or=250 microm vs. none). Among CAPT participants, increased age and focal hyperpigmentation were risk factors for the development of CNV and for GA. Cigarette smoking was significantly associated with CNV only, whereas retinal area covered by drusen and RPE depigmentation were associated significantly with GA only.

Impact of contra-lateral breast reshaping on mammographic surveillance in women undergoing breast reconstruction following mastectomy for breast cancer.

PubMed

Nava, Maurizio B; Rocco, Nicola; Catanuto, Giuseppe; Falco, Giuseppe; Capalbo, Emanuela; Marano, Luigi; Bordoni, Daniele; Spano, Andrea; Scaperrotta, Gianfranco

2015-08-01

The ultimate goal of breast reconstruction is to achieve symmetry with the contra-lateral breast. Contra-lateral procedures with wide parenchymal rearrangements are suspected to impair mammographic surveillance. This study aims to evaluate the impact on mammographic detection of mastopexies and breast reductions for contralateral adjustment in breast reconstruction. We retrospectively evaluated 105 women affected by uni-lateral breast cancer who underwent mastectomy and immediate two-stage reconstruction between 2002 and 2007. We considered three groups according to the contra-lateral reshaping technique: mastopexy or breast reduction with inferior dermoglandular flap (group 1); mastopexy or breast reduction without inferior dermoglandular flap (group 2); no contra-lateral reshaping (group 3). We assessed qualitative mammographic variations and breast density in the three groups. Statistically significant differences have been found when comparing reshaped groups with non reshaped groups regarding parenchymal distortions, skin thickening and stromal edema, but these differences did not affect cancer surveillance. The surveillance mammography diagnostic accuracy in contra-lateral cancer detection was not significantly different between the three groups (p = 0.56), such as the need for MRI for equivocal findings at mammographic contra-lateral breast (p = 0.77) and the need for core-biopsies to confirm mammographic suspect of contra-lateral breast cancer (p = 0.90). This study confirms previous reports regarding the safety of mastopexies and breast reductions when performed in the setting of contra-lateral breast reshaping after breast reconstruction. Mammographic accuracy, sensitivity and specificity are not affected by the glandular re-arrangement. These results provide a further validation of the safety of current reconstructive paradigms. Copyright © 2015 Elsevier Ltd. All rights reserved.

Influence of using a single facial vein as outflow in full-face transplantation: A three-dimensional computed tomographic study.

PubMed

Rodriguez-Lorenzo, Andres; Audolfsson, Thorir; Wong, Corrine; Cheng, Angela; Arbique, Gary; Nowinski, Daniel; Rozen, Shai

2015-10-01

The aim of this study was to evaluate the contribution of a single unilateral facial vein in the venous outflow of total-face allograft using three-dimensional computed tomographic imaging techniques to further elucidate the mechanisms of venous complications following total-face transplant. Full-face soft-tissue flaps were harvested from fresh adult human cadavers. A single facial vein was identified and injected distally to the submandibular gland with a radiopaque contrast (barium sulfate/gelatin mixture) in every specimen. Following vascular injections, three-dimensional computed tomographic venographies of the faces were performed. Images were viewed using TeraRecon Software (Teracon, Inc., San Mateo, CA, USA) allowing analysis of the venous anatomy and perfusion in different facial subunits by observing radiopaque filling venous patterns. Three-dimensional computed tomographic venographies demonstrated a venous network with different degrees of perfusion in subunits of the face in relation to the facial vein injection side: 100% of ipsilateral and contralateral forehead units, 100% of ipsilateral and 75% of contralateral periorbital units, 100% of ipsilateral and 25% of contralateral cheek units, 100% of ipsilateral and 75% of contralateral nose units, 100% of ipsilateral and 75% of contralateral upper lip units, 100% of ipsilateral and 25% of contralateral lower lip units, and 50% of ipsilateral and 25% of contralateral chin units. Venographies of the full-face grafts revealed better perfusion in the ipsilateral hemifaces from the facial vein in comparison with the contralateral hemifaces. Reduced perfusion was observed mostly in the contralateral cheek unit and contralateral lower face including the lower lip and chin units. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Simulating hemispatial neglect with virtual reality.

PubMed

Baheux, Kenji; Yoshizawa, Makoto; Yoshida, Yasuko

2007-07-19

Hemispatial neglect is a cognitive disorder defined as a lack of attention for stimuli contra-lateral to the brain lesion. The assessment is traditionally done with basic pencil and paper tests and the rehabilitation programs are generally not well adapted. We propose a virtual reality system featuring an eye-tracking device for a better characterization of the neglect that will lead to new rehabilitation techniques. This paper presents a comparison of eye-gaze patterns of healthy subjects, patients and healthy simulated patients on a virtual line bisection test. The task was also executed with a reduced visual field condition hoping that fewer stimuli would limit the neglect. We found that patients and healthy simulated patients had similar eye-gaze patterns. However, while the reduced visual field condition had no effect on the healthy simulated patients, it actually had a negative impact on the patients. We discuss the reasons for these differences and how they relate to the limitations of the neglect simulation. We argue that with some improvements the technique could be used to determine the potential of new rehabilitation techniques and also help the rehabilitation staff or the patient's relatives to better understand the neglect condition.

Torsional Eye Movements Evoked by Unilateral Labyrinthine Galvanic Polarizations in the Squirrel Monkey

NASA Technical Reports Server (NTRS)

Minor, Lloyd B.; Tomko, David L.; Paige, Gary D.

1995-01-01

Electrical stimulation of vestibular-nerve afferents innervating the semicircular canals has been used to identify the extraocular muscles receiving activation or inhibition by individual ampullary nerves. This technique was originally developed by Szentagothai (1950) and led to the description of three neuron reflex arcs that connect each semicircular canal through an interneuron traversing in the region of the medial longitudinal fasciculus to one ipsilateral and one contralateral eye muscle. Selective ampullary nerve stimulation was subsequently used by Cohen and colleagues (Cohen and Suzuki, 1963; Cohen et al., 1964; Suzuki et al., 1964; Cohen et al., 1966) to study movements of the eyes and activation of individual extraocular muscles in response to stimulation of combinations of ampullary nerves. This work led to a description of the now familiar relationships between activation of a semicircular canal ampullary nerves and the anticipated movement in each eye. Disconjugacy of eye movements induced by individual vertical canal stimulation and dependence of the pulling direction of vertical recti and oblique muscles on eye position were also defined in these experiments. Subsequent studies have defined the mechanisms by which externally applied galvanic currents result in a change in vestibular-nerve afferent discharge. The currents appear to act at the spike trigger site. Perilymphatic cathodal currents depolarize the trigger site and lead to excitation whereas anodal currents hyperpolarize and result in inhibition. Afferents innervating all five vestibular endorgans appear to be affected equally by the currents (Goldberg et al., 1984). Irregularly discharging afferents are about 5-10 times more sensitive than regularly discharging ones because of the steeper slope of the former's faster postspike recovery of excitability in encoder sensitivity (Smith and Goldberg, 1986). Response adaptation similar to that noted during acceleration steps is apparent for longer periods of current administration. This adaptation is manifested as a perstimulus return toward resting discharge and poststimulus after-response in the opposite direction (Goldberg et al., 1984; Minor and Goldberg, l991). Cathodal currents (with respect to the perilymphatic space of the vestibule) are excitatory whereas anodal currents are inhibitory. Horizontal eye movements evoked by unilateral galvanic polarizations administered through chronically implanted labyrinthine stimulating electrodes have been studied in alert squirrel monkeys (Minor and Goldberg, 1991). We sought to extend this analysis by recording three-dimensional eye movements during galvanic stimulation. As predicted based upon roughly equal stimulation of ampullary nerves innervating the vertical canals, a substantial torsional component to the nystagmus is noted. The trajectory of torsional slow phases and nystagmus profile after the polarization provide insight into the central mechanisms that influence these responses.

Contralateral pulmonary metastases in lung cancer

PubMed Central

Onuigbo, Wilson I. B.

1974-01-01

Onuigbo, W. I. B. (1974).Thorax, 29, 132-133. Contralateral pulmonary metastases in lung cancer. It has long been known that lung cancer may attack many organs and yet spare the opposite lung. In 100 cases of this tumour studied at necropsy, only 22 showed contralateral pulmonary spread. Contralateral deposits are generally small and may be related to damaged tissues. Although tissue unsuitability is supposed to underlie the limitation of metastases in recipient organs, this does not apply to the contralateral lung. Since lung tissue is readily accessible to bloodborne cancer cells, research should be directed towards explaining the paradoxical paucity of the metastases. PMID:4825544

Evaluation of the Contralateral Inguinal Ring in Clinically Unilateral Inguinal Hernia: A Systematic Review and Meta-analysis

PubMed Central

Kokorowski, Paul J; Wang, Hsin-Hsiao Scott; Routh, Jonathan C; Hubert, Katherine C; Nelson, Caleb P

2013-01-01

Purpose The management of the contralateral inguinal canal in children with clinical unilateral inguinal hernia is controversial. Our objective was to systematically review the literature regarding management of the contralateral inguinal canal. Methods We searched MEDLINE, EMBASE, and Cochrane databases (1940–2011) using ‘hernia’ and ‘inguinal’ and either ‘pediatric,’ ‘infant,’ or ‘child,’ to identify studies of pediatric (age≤21 yrs) patients with inguinal hernia. Among clinical unilateral hernia patients, we assessed the number of cases with contralateral patent processus (CPP) and incidence of subsequent clinical metachronous contralateral hernia (MCH). We evaluated three strategies for contralateral management: expectant management, laparoscopic evaluation or pre-operative ultrasound. Pooled estimates of MCH or CPP were generated with random effects by study when heterogeneity was found (I2>50%, or Cochrane’s Q p≥0.10). Results We identified 2,477 non-duplicated studies, 129 of which met our inclusion criteria and had sufficient information for quantitative analysis. The pooled incidence of MCH after open unilateral repair was 7.3% (95% CI 6.5%–8.1%). Laparoscopic examination identified CPP in 30% (95% CI 26%–34%). Lower age was associated with higher incidence of CPP (p<0.01). The incidence of MCH after a negative laparoscopic evaluation was 0.9% (95% CI 0.5%–1.3%). Significant heterogeneity was found in studies and pooled estimates should be interpreted with caution. Conclusions The literature suggests that laparoscopically identified CPP is a poor indicator of future contralateral hernia. Almost a third of patients will have a CPP, while less than one in 10 will develop MCH when managed expectantly. Performing contralateral hernia repair in patients with CPP results in overtreatment in roughly 2 out of 3 patients. PMID:23963735

Smooth-pursuit eye-movement deficits with chemical lesions in macaque nucleus reticularis tegmenti pontis.

PubMed

Suzuki, D A; Yamada, T; Hoedema, R; Yee, R D

1999-09-01

Anatomic and neuronal recordings suggest that the nucleus reticularis tegmenti pontis (NRTP) of macaques may be a major pontine component of a cortico-ponto-cerebellar pathway that subserves the control of smooth-pursuit eye movements. The existence of such a pathway was implicated by the lack of permanent pursuit impairment after bilateral lesions in the dorsolateral pontine nucleus. To provide more direct evidence that NRTP is involved with regulating smooth-pursuit eye movements, chemical lesions were made in macaque NRTP by injecting either lidocaine or ibotenic acid. Injection sites first were identified by the recording of smooth-pursuit-related modulations in neuronal activity. The resulting lesions caused significant deficits in both the maintenance and the initiation of smooth-pursuit eye movements. After lesion formation, the gain of constant-velocity, maintained smooth-pursuit eye movements decreased, on the average, by 44%. Recovery of the ability to maintain smooth-pursuit eye movements occurred over approximately 3 days when maintained pursuit gains attained normal values. The step-ramp, "Rashbass" task was used to investigate the effects of the lesions on the initiation of smooth-pursuit eye movements. Eye accelerations averaged over the initial 80 ms of pursuit initiation were determined and found to be decremented, on the average, by 48% after the administration of ibotenic acid. Impairments in the initiation and maintenance of smooth-pursuit eye movements were directional in nature. Upward pursuit seemed to be the most vulnerable and was impaired in all cases independent of lesioning agent and type of pursuit investigated. Downward smooth pursuit seemed more resistant to the effects of chemical lesions in NRTP. Impairments in horizontal tracking were observed with examples of deficits in ipsilaterally and contralaterally directed pursuit. The results provide behavioral support for the physiologically and anatomic-based conclusion that NRTP is a component of a cortico-ponto-cerebellar circuit that presumably involves the pursuit area of the frontal eye field (FEF) and projects to ocular motor-related areas of the cerebellum. This FEF-NRTP-cerebellum path would parallel a middle and medial superior temporal cerebral cortical area-dorsolateral pontine nucleus-cerebellum pathway also known to be involved with regulating smooth-pursuit eye movements.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harada, Ken, E-mail: keharada@ncc.go.jp; Murakami, Naoya; Kitaguchi, Mayuka

Purpose: To evaluate the natural history, behavior of progression, prognostic factors, and treatment-related adverse effects of primary ocular adnexal mucosa-associated lymphoid tissue (MALT) lymphoma (POAML). Methods and Materials: Eighty-six patients with histologically proven stage I POAML treated with radiation therapy at National Cancer Center Hospital, Tokyo between 1990 and 2010 were retrospectively reviewed. The median age was 56 years (range, 18-85 years). The median dose administered was 30 Gy (range, 30-46 Gy). Seventy-seven patients (90%) were treated by radiation therapy alone. Results: The median follow-up duration was 9 years (range, 0.9-22 years). The 5- and 10-year overall survival (OS) rates were 97.6% and 93.5%, respectively, andmore » no patients died of lymphoma. Patients with tumor sizes ≥4 cm showed a greater risk of contralateral relapse (P=.012). Six patients with contralateral relapse were seen and treated by radiation therapy alone, and all the lesions were controlled well, with follow-up times of 3 to 12 years. There was 1 case of local relapse after radiation therapy alone, and 3 cases of relapse occurred in a distant site. Cataracts developed in 36 of the 65 eyes treated without lens shielding and in 12 of the 39 patients with lens shielding (P=.037). Conclusions: The majority of patients with POAML showed behavior consistent with that of localized, indolent diseases. Thirty gray of local irradiation seems to be quite effective. The initial bilateral involvement and contralateral orbital relapses can be also controlled with radiation therapy alone. Lens shielding reduces the risk of cataract.« less

Restoration of Vision in the pde6β-deficient Dog, a Large Animal Model of Rod-cone Dystrophy

PubMed Central

Petit, Lolita; Lhériteau, Elsa; Weber, Michel; Le Meur, Guylène; Deschamps, Jack-Yves; Provost, Nathalie; Mendes-Madeira, Alexandra; Libeau, Lyse; Guihal, Caroline; Colle, Marie-Anne; Moullier, Philippe; Rolling, Fabienne

2012-01-01

Defects in the β subunit of rod cGMP phosphodiesterase 6 (PDE6β) are associated with autosomal recessive retinitis pigmentosa (RP), a childhood blinding disease with early retinal degeneration and vision loss. To date, there is no treatment for this pathology. The aim of this preclinical study was to test recombinant adeno-associated virus (AAV)-mediated gene addition therapy in the rod-cone dysplasia type 1 (rcd1) dog, a large animal model of naturally occurring PDE6β deficiency that strongly resembles the human pathology. A total of eight rcd1 dogs were injected subretinally with AAV2/5RK.cpde6β (n = 4) or AAV2/8RK.cpde6β (n = 4). In vivo and post-mortem morphological analysis showed a significant preservation of the retinal structure in transduced areas of both AAV2/5RK.cpde6β- and AAV2/8RK.cpde6β-treated retinas. Moreover, substantial rod-derived electroretinography (ERG) signals were recorded as soon as 1 month postinjection (35% of normal eyes) and remained stable for at least 18 months (the duration of the study) in treated eyes. Rod-responses were undetectable in untreated contralateral eyes. Most importantly, dim-light vision was restored in all treated rcd1 dogs. These results demonstrate for the first time that gene therapy effectively restores long-term retinal function and vision in a large animal model of autosomal recessive rod-cone dystrophy, and provide great promise for human treatment. PMID:22828504

Restoration of vision in the pde6β-deficient dog, a large animal model of rod-cone dystrophy.

PubMed

Petit, Lolita; Lhériteau, Elsa; Weber, Michel; Le Meur, Guylène; Deschamps, Jack-Yves; Provost, Nathalie; Mendes-Madeira, Alexandra; Libeau, Lyse; Guihal, Caroline; Colle, Marie-Anne; Moullier, Philippe; Rolling, Fabienne

2012-11-01

Defects in the β subunit of rod cGMP phosphodiesterase 6 (PDE6β) are associated with autosomal recessive retinitis pigmentosa (RP), a childhood blinding disease with early retinal degeneration and vision loss. To date, there is no treatment for this pathology. The aim of this preclinical study was to test recombinant adeno-associated virus (AAV)-mediated gene addition therapy in the rod-cone dysplasia type 1 (rcd1) dog, a large animal model of naturally occurring PDE6β deficiency that strongly resembles the human pathology. A total of eight rcd1 dogs were injected subretinally with AAV2/5RK.cpde6β (n = 4) or AAV2/8RK.cpde6β (n = 4). In vivo and post-mortem morphological analysis showed a significant preservation of the retinal structure in transduced areas of both AAV2/5RK.cpde6β- and AAV2/8RK.cpde6β-treated retinas. Moreover, substantial rod-derived electroretinography (ERG) signals were recorded as soon as 1 month postinjection (35% of normal eyes) and remained stable for at least 18 months (the duration of the study) in treated eyes. Rod-responses were undetectable in untreated contralateral eyes. Most importantly, dim-light vision was restored in all treated rcd1 dogs. These results demonstrate for the first time that gene therapy effectively restores long-term retinal function and vision in a large animal model of autosomal recessive rod-cone dystrophy, and provide great promise for human treatment.

Postoperative corneal shape changes: microincision versus small-incision coaxial cataract surgery.

PubMed

Hayashi, Ken; Yoshida, Motoaki; Hayashi, Hideyuki

2009-02-01

To compare changes in corneal topography and in regular and irregular astigmatism after coaxial clear corneal microincision cataract surgery (MICS) and after coaxial small-incision cataract surgery (SICS). Hayashi Eye Hospital, Fukuoka, Japan. Induced corneal astigmatism was determined using vector analysis. The averaged corneal shape changes and degree of irregular astigmatism were examined using videokeratography preoperatively as well as 2 days and 1, 2, 4, and 8 weeks postoperatively. One hundred twenty eyes of 60 patients scheduled for phacoemulsification were evaluated. Sixty eyes had MICS (2.00 mm), and the 60 contralateral eyes had SICS (2.65 mm). The mean induced corneal astigmatism was significantly less in the MICS group than in the SICS group (P

Contralateral Cruciate Survival in Dogs with Unilateral Non-Contact Cranial Cruciate Ligament Rupture

PubMed Central

Muir, Peter; Schwartz, Zeev; Malek, Sarah; Kreines, Abigail; Cabrera, Sady Y.; Buote, Nicole J.; Bleedorn, Jason A.; Schaefer, Susan L.; Holzman, Gerianne; Hao, Zhengling

2011-01-01

Background Non-contact cranial cruciate ligament rupture (CrCLR) is an important cause of lameness in client-owned dogs and typically occurs without obvious injury. There is a high incidence of bilateral rupture at presentation or subsequent contralateral rupture in affected dogs. Although stifle synovitis increases risk of contralateral CrCLR, relatively little is known about risk factors for subsequent contralateral rupture, or whether therapeutic intervention may modify this risk. Methodology/Principal Findings We conducted a longitudinal study examining survival of the contralateral CrCL in client-owned dogs with unilateral CrCLR in a large baseline control population (n = 380), and a group of dogs that received disease-modifying therapy with arthroscopic lavage, intra-articular hyaluronic acid and oral doxycycline (n = 16), and were followed for one year. Follow-up in treated dogs included analysis of mobility, radiographic evaluation of stifle effusion and arthritis, and quantification of biomarkers of synovial inflammation. We found that median survival of the contralateral CrCL was 947 days. Increasing tibial plateau angle decreased contralateral ligament survival, whereas increasing age at diagnosis increased survival. Contralateral ligament survival was reduced in neutered dogs. Our disease-modifying therapy did not significantly influence contralateral ligament survival. Correlative analysis of clinical and biomarker variables with development of subsequent contralateral rupture revealed few significant results. However, increased expression of T lymphocyte-associated genes in the index unstable stifle at diagnosis was significantly related to development of subsequent non-contact contralateral CrCLR. Conclusion Subsequent contralateral CrCLR is common in client-owned dogs, with a median ligament survival time of 947 days. In this naturally occurring model of non-contact cruciate ligament rupture, cranial tibial translation is preceded by development of synovial inflammation. However, treatment with arthroscopic lavage, intra-articular hyaluronic acid and oral doxycycline does not significantly influence contralateral CrCL survival. PMID:21998650

Efficacy and safety of cross-cylinder photorefractive keratectomy versus single method in medium-high astigmatism: a randomized clinical trial.

PubMed

Sedghipour, Mohammad R; Lotfi, Afshin; Sadeghilar, Ayaz; Banan, Saeeid

2012-09-07

BACKGROUND: To compare efficacy and safety of photorefractive keratectomy (PRK) by cross-cylinder with single methods in medium-high astigmatism. DESIGN: Randomized clinical trial study PARTICIPANTS: Fifty patients with medium-high compound myopic astigmatism were enrolled between September 2007 and September 2008. METHODS: PRK was performed on 100 eyes of 50 patients with compound myopic astigmatism. Each patient underwent PRK by cross-cylinder approach in one eye and single method on the contralateral eye. Vector analysis was used to assess astigmatic results. MAIN OUTCOME MEASURES: Improvement of visual acuity (snelen chart), refraction, aberrometry. RESULTS: Uncorrected visual acuity (UCCA) equal to 20/40 or better after six months, was achieved in 98% of eyes in the cross-cylinder method versus 96% in single method.. Mean preoperative spherical equivalent(SE) was -5.2 ±2.1 D in the cross-cylinder method versus -5.1 ±0.5 D in the single method. At six months, the mean SE was - 0.5±0.4 D and -0.6±0.3 D, respectively. Mean IOS was 0.4±0.3 in the cross-cylinder group and 0.4±0.4 in the single group. Mean postoperative absolute change in total root-mean-square higher order aberrations in the cross-cylinder group and single group were 0.16 pm and 0.17 pm, respectively. Any of the mentioned differences didn't appear to be statistically significant. CONCLUSIONS: Both PRK methods appeared to be safe and effective in correcting medium-high astigmatism. © 2012 The Author. Clinical and Experimental Ophthalmology © 2012 Royal Australian and New Zealand College of Ophthalmologists.

The effects of subconjunctival bupivacaine, lidocaine, and mepivacaine on corneal sensitivity in healthy horses.

PubMed

Jinks, Maggie R; Fontenot, Robin L; Wills, Robert W; Betbeze, Caroline M

2017-12-12

To compare the efficacy and duration of effect of three local anesthetics on corneal sensitivity when administered subconjunctivally in horses. Eight healthy adult horses. A randomized, masked, crossover study design was used, with a two-week washout period between trials. The subconjunctival space of the randomly selected eye was injected with 0.2 mLs of bupivacaine (0.5%), lidocaine (2%), mepivacaine (2%), or saline. All horses received each medication once. The contralateral eye served as a control. The corneal touch threshold (CTT) was measured in both eyes with a Cochet-Bonnet esthesiometer prior to sedation with xylazine, after sedation, and at 10-min intervals after subconjunctival injection until corneal sensitivity returned to baseline. The total time of decreased CTT and the maximum decrease in CTT were compared for each medication using a general linear mixed model (P < 0.05). Total time of decreased CTT was 105.0 min for bupivacaine, 103.8 min for lidocaine, 138.8 min for mepivacaine, and 7.5 min for saline. All local anesthetics decreased CTT longer than saline (P < 0.001) and mepivacaine decreased CTT longer than lidocaine (P = 0.04). The mean minimum CTT was 1.67 cm for bupivacaine, 1.42 cm for lidocaine, and 0.73 cm for mepivacaine, which were all significantly less (P < 0.001) than saline (4.73 cm). No evidence of corneal toxicity was noted with any treatment. Subconjunctival injections of lidocaine, bupivacaine, and mepivacaine effectively and safely reduce corneal sensitivity in eyes of healthy horses for 1.5-2 h, and may be useful for providing perioperative analgesia for equine corneal procedures. © 2017 American College of Veterinary Ophthalmologists.

Comparison of Tear cytokines and clinical outcomes between off-flap and on-flap epi-LASIK with mitomycin C.

PubMed

Zhang, Yu; Chen, Yue-Guo; Xia, Ying-Jie; Qi, Hong

2012-09-01

To compare tear cytokines and clinical outcomes between off-flap and on-flap epi-LASIK eyes and explore the possible mechanism for the clinical differences. This double-masked, randomized study enrolled 18 myopic patients who underwent off-flap epi-LASIK with mitomycin C (MMC) in 1 eye and on-flap epi-LASIK with MMC in the contralateral eye. Tears were collected from each eye preoperatively and 2 hours, 1 day, and 5 days postoperatively. Concentrations of multiple tear cytokines were measured by a multiplex immunobead assay. Uncorrected distance visual acuity (UDVA), refraction, haze scores, pain scores, and percentage of corneal epithelial healing were evaluated. Compared with the on-flap group, the off-flap group had outcomes of better UDVA and higher percentages of epithelial healing at 5 days after surgery (P<.001) and lower levels of haze at 1 month after surgery (P=.049). Preoperatively, no significant differences were noted in the release rate of all tear cytokines between groups. At 2 hours postoperatively, the release rate of tear basic fibroblast growth factor (bFGF), platelet-derived growth factor-BB (PDGF-BB), interleukin-8 (IL-8), and tumor necrosis factor alpha (TNF-α) in the off-flap group were significantly lower than those in the on-flap group (P=.011, .017, .048, and .041, respectively). Off-flap epi-LASIK with MMC offers faster corneal epithelial healing and visual recovery, and temporary less haze than on-flap epi-LASIK with MMC. The lower tear levels of bFGF, PDGF-BB, IL-8, and TNF-α in the offflap group 2 hours after surgery may suggest a possible mechanism for the clinical differences. Copyright 2012, SLACK Incorporated.

PRK and butterfly LASEK: prospective, randomized, contralateral eye comparison of epithelial healing and ocular discomfort.

PubMed

Ghanem, Vinícius C; Souza, Giselle C; Souza, Denise C; Viese, Juliana M Z; Weber, Sarah L P; Kara-José, Newton

2008-06-01

To compare corneal reepithelialization, pain scores, ocular discomfort, and tear production after photorefractive keratectomy (PRK) and butterfly laser epithelial keratomileusis (LASEK). This prospective, randomized, double-masked study comprised 102 eyes of 51 patients who underwent laser refractive surgery. Each patient was randomized to have one eye operated on with PRK and the other with butterfly LASEK. Patients were followed for 1 year. The mean reepithelialization time in the PRK group was 4.35+/-0.48 days (range: 4 to 5 days) and 4.75+/-0.72 days (range: 4 to 6 days) in the butterfly LASEK group (P<.002). Pain scores and ocular discomfort were not statistically different between groups, although a trend towards a lower pain level with PRK was noted (3.31+/-4.09 vs 4.43+/-4.27; P=.18). Schirmer test values were significantly reduced from preoperative levels through 12 months with both PRK (23.6+/-8.1 vs 19.4+/-10.1; P<.002) and butterfly LASEK (22.4+/-8.7 vs 18.9+/-9.7; P=.01); however, no difference between groups was noted at any time. Photorefractive keratectomy showed a modest but statistically significant shorter reepithelialization time and a tendency towards lower pain scores than butterfly LASEK. The reepithelialization time was strongly associated with the duration of surgery in both techniques. A similar reduction of Schirmer test values was observed up to 1 year postoperatively in both groups.

Changes in cytokines in tears after endoscopic endonasal dacryocystorhinostomy for primary acquired nasolacrimal duct obstruction.

PubMed

Lee, J K; Kim, T H

2014-05-01

We attempted to compare the cytokine composition of tears between primary acquired nasolacrimal duct (NLD) obstruction and normal controls. We investigated the changes in cytokines in tears after endoscopic endonasal dacryocystorhinostomy (DCR). Eighteen patients underwent endonasal DCR, with seven patients undergoing bilateral DCR, resulting in twenty-five DCRs in total. Eleven contralateral un-operated eyes were used as normal controls. Silicone stents were removed 3 months after surgery. Tear samples were collected from all eyes before surgery, and at 1 month, 2 months, 3 months, and 4 months after surgery. The level of interleukin (IL)-1β, IL-2, IL-6, IL-10, transforming growth factor (TGF)-β2, fibroblast growth factor (FGF)-2, and vascular endothelial growth factor (VEGF) in the tears was measured. The concentrations of IL-2, IL-6, IL-10, VEGF, and FGF-2 were significantly higher in eyes with NLD obstruction than controls before surgery (P=0.006, 0.018, 0.002, 0.048, and 0.039, respectively). Most inflammatory cytokines (IL-1β, IL-2, IL-6, VEGF, and FGF-2) were higher in the tears of the DCR group compared with the controls during the postoperative follow-up, but then rapidly decreased to the level of the controls after removal of the silicone stent. The recurred eyes showed a higher level of TGF-β2 and FGF-2 in tears compared with the eyes that showed good surgical results (P<0.005 and <0.005, respectively). The tear levels of inflammatory cytokines were higher in eyes with NLD obstruction than controls. The changes in cytokine level during the postoperative period showed the importance of cytokine analysis in understanding wound healing after DCR.

Tinnitus Intensity Dependent Gamma Oscillations of the Contralateral Auditory Cortex

PubMed Central

van der Loo, Elsa; Gais, Steffen; Congedo, Marco; Vanneste, Sven; Plazier, Mark; Menovsky, Tomas; Van de Heyning, Paul; De Ridder, Dirk

2009-01-01

Background Non-pulsatile tinnitus is considered a subjective auditory phantom phenomenon present in 10 to 15% of the population. Tinnitus as a phantom phenomenon is related to hyperactivity and reorganization of the auditory cortex. Magnetoencephalography studies demonstrate a correlation between gamma band activity in the contralateral auditory cortex and the presence of tinnitus. The present study aims to investigate the relation between objective gamma-band activity in the contralateral auditory cortex and subjective tinnitus loudness scores. Methods and Findings In unilateral tinnitus patients (N = 15; 10 right, 5 left) source analysis of resting state electroencephalographic gamma band oscillations shows a strong positive correlation with Visual Analogue Scale loudness scores in the contralateral auditory cortex (max r = 0.73, p<0.05). Conclusion Auditory phantom percepts thus show similar sound level dependent activation of the contralateral auditory cortex as observed in normal audition. In view of recent consciousness models and tinnitus network models these results suggest tinnitus loudness is coded by gamma band activity in the contralateral auditory cortex but might not, by itself, be responsible for tinnitus perception. PMID:19816597

Does the type of somatosensory information from the contralateral finger touch affect grip force control while lifting an object?

PubMed

Chen, Bing; Aruin, Alexander S

2013-11-27

The magnitude of grip force used to lift and transport a hand-held object is decreased if a light finger touch from the contralateral arm is provided to the wrist of the target arm. We investigated whether the type of contralateral arm sensory input that became available with the finger touch to the target arm affects the way grip force is reduced. Nine healthy subjects performed the same task of lifting and transporting an instrumented object with no involvement of the contralateral arm and when an index finger touch of the contralateral arm was provided to the wrist, elbow, and shoulder. Touching the wrist and elbow involved movements of the contralateral arm; no movements were produced while touching the shoulder. Grip force was reduced by approximately the same amount in all conditions with the finger touch compared to the no touch condition. This suggests that information from the muscle and joint receptors of the contralateral arm is used in control of grip force when a finger touch is provided to the wrist and elbow, and cutaneous information is utilized when lifting an object while touching the shoulder. The results of the study provide additional evidence to support the use of a second arm in the performance of activities of daily living and stress the importance of future studies investigating contralateral arm sensory input in grip force control. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Long-term outcomes of gene therapy for the treatment of Leber's hereditary optic neuropathy.

PubMed

Yang, Shuo; Ma, Si-Qi; Wan, Xing; He, Heng; Pei, Han; Zhao, Min-Jian; Chen, Chen; Wang, Dao-Wen; Dong, Xiao-Yan; Yuan, Jia-Jia; Li, Bin

2016-08-01

Leber's hereditary optic neuropathy (LHON) is a disease that leads to blindness. Gene therapy has been investigated with some success, and could lead to important advancements in treating LHON. This was a prospective, open-label trial involving 9 LHON patients at Tongji Hospital, Wuhan, China, from August 2011 to December 2015. The purpose of this study was to evaluate the long-term outcomes of gene therapy for LHON. Nine LHON patients voluntarily received an intravitreal injection of rAAV2-ND4. Systemic examinations and visual function tests were performed during the 36-month follow-up period to determine the safety and efficacy of this gene therapy. Based on successful experiments in an animal model of LHON, 1 subject also received an rAAV2-ND4 injection in the second eye 12months after gene therapy was administered in the first eye. Recovery of visual acuity was defined as the primary outcome of this study. Changes in the visual field, visual evoked potential (VEP), optical coherence tomography findings, liver and kidney function, and antibodies against AAV2 were defined as secondary endpoints. Eight patients (Patients 2-9) received unilateral gene therapy and visual function improvement was observed in both treated eyes (Patients 4, 6, 7, and 8) and untreated eyes (Patients 2, 3, 4, 6 and 8). Visual regression fluctuations, defined as changes in visual acuity greater than or equal to 0.3 logMAR, were observed in Patients 2 and 9. Age at disease onset, disease duration, and the amount of remaining optic nerve fibers did not have a significant effect on the visual function improvement. The visual field and pattern reversal VEP also improved. The patient (Patient 1) who received gene therapy in both eyes had improved visual acuity in the injected eye after the first treatment. Unfortunately, visual acuity in this eye decreased 3months after he received gene therapy in the second eye. Animal experiments suggested that ND4 expression remains stable in the contralateral eye after intravitreal injections. No serious safety problem was observed in the 3-year follow-up of the 9 participants enrolled in this virus-based gene therapy. Meanwhile, our results support the use of intravitreal rAAV2-ND4 as an aggressive maneuver in our clinical trial. Further study in additional patients and in these 9 subjects is needed to better understand the effects of rAAV2-ND4 gene therapy on LHON and to increase the applications of this technique. Copyright © 2016 The Ohio State University Wexner Medical Center. Published by Elsevier B.V. All rights reserved.

Improved detection following Neuro-Eye Therapy in patients with post-geniculate brain damage.

PubMed

Sahraie, Arash; Macleod, Mary-Joan; Trevethan, Ceri T; Robson, Siân E; Olson, John A; Callaghan, Paula; Yip, Brigitte

2010-09-01

Damage to the optic radiation or the occipital cortex results in loss of vision in the contralateral visual field, termed partial cortical blindness or hemianopia. Previously, we have demonstrated that stimulation in the field defect using visual stimuli with optimal properties for blindsight detection can lead to increases in visual sensitivity within the blind field of a group of patients. The present study was aimed to extend the previous work by investigating the effect of positive feedback on recovery of visual sensitivity. Patients' abilities for detection of a range of spatial frequencies within their field defect were determined using a temporal two-alternative forced-choice technique, before and after a period of visual training (n = 4). Patients underwent Neuro-Eye Therapy which involved detection of temporally modulated spatial grating patches at specific retinal locations within their field defect. Three patients showed improved detection ability following visual training. Based on our previous studies, we had hypothesised that should the occipital brain lesion extend anteriorly to the thalamus, little recovery would be expected. Here, we describe one such case who showed no improvements after extensive training. The present study provides further evidence that recovery (a) can be gradual and may require a large number of training sessions (b) can be accelerated using positive feedback and (c) may be less likely to take place if the occipital damage extends anteriorly to the thalamus.

Can sparing of the superficial contralateral parotid lobe reduce xerostomia following radiotherapy for head and neck cancer?

PubMed

Nevens, Daan; Nuyts, Sandra

2017-12-01

The purpose of this study is to see whether sparing the superficial contralateral parotid lobe can help limiting xerostomia following radiotherapy for head and neck cancer. 88 patients that were included in two prospective randomized studies were analysed in the current study. Using the dosimetry of both the parotid glands, we divided our patients in four groups. Group 1 includes patients where we were able to reduce the radiation dose below the threshold in order to spare both the ipsilateral and contralateral parotid glands, Group 2 consists of patients where only the contralateral parotid gland could be spared. Group 3 consists of patients where only the contralateral superficial parotid lobe could be spared, while in Group 4 not even the contralateral superficial lobe could be spared. When we compared Group 1 and Group 2, we did not observe a significant difference between both groups in terms of xerostomia scores at 6 or 12 months. When we compared these groups with Group 3, we observed significant differences with more xerostomia in Group 3 where only the contralateral superficial lobe was spared. A significant difference was also observed between Group 3 and Group 4 with more xerostomia in Group 4. Sparing of just one superficial parotid lobe results in less xerostomia when compared to not sparing any lobe of both parotid glands. Advances in knowledge: When sparing of the whole contralateral parotid gland is not possible, delineating both the superficial parotid glands and trying to spare at least one of them can mean a way forward in limiting xerostomia in head and neck cancer patients treated with radiotherapy.

Sustained neuroprotection from a single intravitreal injection of PGJ₂ in a nonhuman primate model of nonarteritic anterior ischemic optic neuropathy.

PubMed

Miller, Neil R; Johnson, Mary A; Nolan, Theresa; Guo, Yan; Bernstein, Alexander M; Bernstein, Steven L

2014-10-08

Prostaglandin J₂ (PGJ₂) is neuroprotective in a murine model of nonarteritic anterior ischemic optic neuropathy (NAION). After assessing for potential toxicity, we evaluated the efficacy of a single intravitreal (IVT) injection of PGJ₂ in a nonhuman primate model of NAION (pNAION). We assessed PGJ₂ toxicity by administering it as a single high-dose intravenous (IV) injection, consecutive daily high-dose IV injections, or a single IVT injection in one eye of five adult rhesus monkeys. To assess efficacy, we induced pNAION in one eye of five adult male rhesus monkeys using a laser-activated rose bengal induction method. We then injected the eye with either PGJ₂ or phosphate-buffered saline (PBS) intravitreally immediately or 5 hours post induction. We performed a clinical assessment, optical coherence tomography, electrophysiological testing, fundus photography, and fluorescein angiography in all animals prior to induction and at 1 day, 1 week, 2 weeks, and 4 weeks after induction. Following analysis of the first eye, we induced pNAION in the contralateral eye and then injected either PGJ₂ or PBS. We euthanized all animals 5 weeks after final assessment of the fellow eye and performed both immunohistochemical and light and electron microscopic analyses of the retina and optic nerves. PGJ₂ caused no permanent systemic toxicity regardless of the amount injected or route of delivery, and there was no evidence of any ocular toxicity with the dose of PGJ₂ used in efficacy studies. Transient reduction in the amplitudes of the visual evoked potentials and the N95 component of the pattern electroretinogram (PERG) occurred after both IV and IVT administration of high doses of PGJ₂; however, the amplitudes returned to normal in all animals within 1 week. In all eyes, a single IVT dose of PGJ₂ administered immediately or shortly after induction of pNAION resulted in a significant reduction of clinical, electrophysiological, and histological damage compared with vehicle-injected eyes (P = 0.03 for both VEP and PERG; P = 0.05 for axon counts). In nonhuman primates, PGJ₂ administered either intravenously or intravitreally produces no permanent toxicity at even four times the dose given for neuroprotection. Additionally, a single IVT dose of PGJ₂ is neuroprotective when administered up to 5 hours after induction of pNAION. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Robotic simulation of identical athletic-task kinematics on cadaveric limbs exhibits a lack of differences in knee mechanics between contralateral pairs

PubMed Central

Bates, Nathaniel A.; McPherson, April L.; Nesbitt, Rebecca J.; Shearn, Jason T.; Myer, Gregory D.; Hewett, Timothy E.

2017-01-01

Limb asymmetry is a known factor for increased ACL injury risk. These asymmetries are normally observed during in vivo testing. Prior studies have developed in vitro testing methodologies driven by in vivo kinematics to investigate knee mechanics relative to ACL injury. The objective of this study was to determine if mechanical side-to-side asymmetries persist in contralateral pairs during in vitro simulation testing. In vivo kinematics were recorded for male and female drop vertical jump and sidestep cutting tasks. The recorded kinematics were used to robotically simulate the motions on 7 contralateral pairs of cadaveric lower extremities specimens. ACL and MCL force, torque, and strains were recorded and analyzed for differences between contralateral pairs. There was a general lack of mechanical differences between limb sides. Adduction peak torque for the male sidestep cut movement was significantly different between limb sides (p = 0.04). However, this is consistent with ACL injury mechanics in that movement in the frontal plane (abduction/adduction) increases injury risk and it is possible loading differences in this plane may have resulted from tolerances within the setup process. The findings of this study indicate that contralateral knee joints were representative of each other during biomechanical in vitro tests. In future cadaveric robotic simulations, contralateral limbs can be used interchangeably. In addition, direct comparisons of the structural behaviors of isolated conditions for contralateral knee joints can be performed. PMID:28062120

Trans-falcine and contralateral sub-frontal electrode placement in pediatric epilepsy surgery: technical note.

PubMed

Pindrik, Jonathan; Hoang, Nguyen; Tubbs, R Shane; Rocque, Brandon J; Rozzelle, Curtis J

2017-08-01

Phase II monitoring with intracranial electroencephalography (ICEEG) occasionally requires bilateral placement of subdural (SD) strips, grids, and/or depth electrodes. While phase I monitoring often demonstrates a preponderance of unilateral findings, individual studies (video EEG, single photon emission computed tomography [SPECT], and positron emission tomography [PET]) can suggest or fail to exclude a contralateral epileptogenic onset zone. This study describes previously unreported techniques of trans-falcine and sub-frontal insertion of contralateral SD grids and depth electrodes for phase II monitoring in pediatric epilepsy surgery patients when concern about bilateral abnormalities has been elicited during phase I monitoring. Pediatric patients with medically refractory epilepsy undergoing stage I surgery for phase II monitoring involving sub-frontal and/or trans-falcine insertion of SD grids and/or depth electrodes at the senior author's institution were retrospectively reviewed. Intra-operative technical details of sub-frontal and trans-falcine approaches were studied, while intra-operative complications or events were noted. Operative techniques included gentle subfrontal retraction and elevation of the olfactory tracts (while preserving the relationship between the olfactory bulb and cribriform plate) to insert SD grids across the midline for coverage of the contralateral orbito-frontal regions. Trans-falcine approaches involved accessing the inter-hemispheric space, bipolar cauterization of the anterior falx cerebri below the superior sagittal sinus, and sharp dissection using a blunt elevator and small blade scalpel. The falcine window allowed contralateral SD strip, grid, and depth electrodes to be inserted for coverage of the contralateral frontal regions. The study cohort included seven patients undergoing sub-frontal and/or trans-falcine insertion of contralateral SD strip, grid, and/or depth electrodes from February 2012 through June 2015. Five patients (71%) experienced no intra-operative events related to contralateral ICEEG electrode insertion. Intra-operative events of frontal territory venous engorgement (1/7, 14%) due to sacrifice of anterior bridging veins draining into the SSS and avulsion of a contralateral bridging vein (1/7, 14%), probably due to prior anterior corpus callosotomy, each occurred in one patient. There were no intra-operative or peri-operative complications in any of the patients studied. Two patients required additional surgery for supplemental SD strip and/or depth electrodes via burr hole craniectomy to enhance phase II monitoring. All patients proceeded to stage II surgery for resection of ipsilateral epileptogenic onset zones without adverse events. Trans-falcine and sub-frontal insertion of contralateral SD strip, grid, and depth electrodes are previously unreported techniques for achieving bilateral frontal coverage in phase II monitoring in pediatric epilepsy surgery. This technique obviates the need for contralateral craniotomy and parenchymal exposure with limited, remediable risks. Larger case series using the method described herein are now necessary.

Difference in postural control between patients with functional and mechanical ankle instability.

PubMed

Chen, Henry; Li, Hong-Yun; Zhang, Jian; Hua, Ying-Hui; Chen, Shi-Yi

2014-10-01

Lateral ankle sprain is one of the most common injuries. Since the structural and pathological differences in mechanical ankle instability (MAI) and functional ankle instability (FAI) may not be the same, it may be better to treat these as separate groups. The purpose of this study was to compare the difference in postural sway between MAI and FAI in patients with chronic ankle instability (CAI). Twenty-six patients with CAI and 14 healthy control participants were included in the study. The CAI patients were subdivided into MAI (15 patients) and FAI (11 patients) groups. Patients who were diagnosed with lateral ankle ligaments rupture by magnetic resonance imaging and ultrasonography were assigned to the MAI group. All participants performed single-limb postural sway tests 3 times on each leg with eyes closed and open. The average distances from the mean center of pressure position in the mediolateral and anteroposterior directions were recorded and compared among the 3 groups. The unstable ankles in the MAI group showed significantly greater postural sway in the anterior, posterior, and medial directions compared with those in the control group with eyes closed. With eyes open, significantly greater postural sway was found in the anterior direction. In the FAI group, no difference was found in postural sway compared with those in the control group. The MAI group showed significantly greater postural sway in the anterior direction compared with the FAI group with eyes closed and open. No significant difference in postural sway was found between the unstable and stable ankles in the MAI or FAI groups, with or without vision. Patients with MAI have deficits in postural control, especially in anterior-posterior directions. However, no difference was found in postural sway in patients with FAI compared with healthy people. As MAI patients suffer from deficits in postural control, balance training should be applied in those patients. In addition, special training should also include the contralateral side after a unilateral ankle ligament injured. © The Author(s) 2014.

Experimental erbium: YAG laser photoablation of trabecular meshwork in rabbits: an in-vivo study.

PubMed

Dietlein, T S; Jacobi, P C; Schröder, R; Krieglstein, G K

1997-05-01

Photoablative laser trabecular surgery has been proposed as an outflow-enhancing treatment for open-angle glaucoma. The aim of the study was to investigate the time course of repair response following low-thermal Erbium: YAG laser trabecular ablation. In 20 anaesthetized rabbits gonioscopically controlled ab-interno photoablation of the ligamenta pectinata and underlying trabecular meshwork (TM) was performed with a single-pulsed (200 microseconds) Erbium: YAG (2.94 microns) laser. The right eye received 12-15 single laser pulses (2 mJ) delivered through an articulated zirconium fluoride fiberoptic and a 200 microns (core diameter) quartz fiber tip, the left unoperated eye served as control. At time intervals of 30 minutes, 2, 10, 30, and 60 days after laser treatment, eyes were processed for light- and scanning electron microscopy. The applied energy density of 6-4 J cm-2 resulted in visible dissection of the ligamenta pectinata and reproducible microperforations of the TM exposing scleral tissue accompanied by blood reflux from the aqueous plexus. The initial ablation zones measured 154 +/- 36 microns in depth and 45 +/- 6 microns in width. Collateral thermal damage zones were 22 +/- 8 microns. At two days post-operative, ablation craters were still blood- and fibrin-filled. The inner surface of the craters were covered with granulocytes. No cellular infiltration of the collateral thermal damage zone was observed. At 10 days post-operative, progressive fibroblastic proliferation was observed, resulting in dense scar tissue formation with anterior synechiae, proliferating capillaries and loss of intertrabecular spaces inside the range of former laser treatment at 60 days post-operative. Trabecular microperforations were closed 60 days after laser treatment in all rabbits. IOP in treated and contralateral eyes did not significantly change its level during whole period of observation. Low-thermal infrared laser energy with minimal thermal damage to collateral structures could not effectively prevent early scarring of trabecular surgery in rabbits.

Does Roller Massage With a Foam Roll Change Pressure Pain Threshold of the Ipsilateral Lower Extremity Antagonist and Contralateral Muscle Groups? An Exploratory Study.

PubMed

Cheatham, Scott W; Kolber, Morey J

2018-03-01

Foam rolling is a popular intervention used by allied health professionals and the general population. Current research suggests that foam rolling may have an effect on the ipsilateral antagonist muscle group and produce a cross-over effect in the muscles of the contralateral limb. The purpose of this study was to examine the acute effects of foam rolling to the left quadriceps on ipsilateral antagonist hamstrings and contralateral quadriceps muscle group pressure pain threshold (PPT). Through this research, we sought to gather data to further develop the methodology for future studies of this intervention. A pretest-posttest exploratory study. University kinesiology laboratory. 21 healthy adults (age = 27.52 ± 8.9 y). Video-guided foam roll intervention on the left quadriceps musculature. Ipsilateral hamstring (antagonist) and contralateral quadriceps muscle PPT. A significant difference was found between pretest to posttest measures for the ipsilateral hamstrings (t[20] = -6.2, P < 0.001) and contralateral quadriceps (t[20] = -9.1, P < 0.001) suggesting an increase in PPT. These findings suggest that foam rolling of the quadriceps musculature may have an acute effect on the PPT of the ipsilateral hamstrings and contralateral quadriceps muscles. Clinicians should consider these results to be exploratory and future investigations examining this intervention on PPT is warranted.

Nitric oxide facilitates GABAergic neurotransmission in the cat oculomotor system: a physiological mechanism in eye movement control

PubMed Central

Moreno-López, Bernardo; Escudero, Miguel; Estrada, Carmen

2002-01-01

Nitric oxide (NO) synthesis by prepositus hypoglossi (PH) neurons is necessary for the normal performance of horizontal eye movements. We have previously shown that unilateral injections of NO synthase (NOS) inhibitors into the PH nucleus of alert cats produce velocity imbalance without alteration of the eye position control, both during spontaneous eye movements and the vestibulo-ocular reflex (VOR). This NO effect is exerted on the dorsal PH neuropil, whose fibres increase their cGMP content when stimulated by NO. In an attempt to determine whether NO acts by modulation of a specific neurotransmission system, we have now compared the oculomotor effects of NOS inhibition with those produced by local blockade of glutamatergic, GABAergic or glycinergic receptors in the PH nucleus of alert cats. Both glutamatergic antagonists used, 2-amino-5-phosphonovaleric acid (APV) and 2,3-dihydro-6-nitro-7-sulphamoyl-benzo quinoxaline (NBQX), induced a nystagmus contralateral to that observed upon NOS inhibition, and caused exponential eye position drift. In contrast, bicuculline and strychnine induced eye velocity alterations similar to those produced by NOS inhibitors, suggesting that NO oculomotor effects were due to facilitation of some inhibitory input to the PH nucleus. To investigate the anatomical location of the putative NO target neurons, the retrograde tracer Fast Blue was injected in one PH nucleus, and the brainstem sections containing Fast Blue-positive neurons were stained with double immunohistochemistry for NO-sensitive cGMP and glutamic acid decarboxylase. GABAergic neurons projecting to the PH nucleus and containing NO-sensitive cGMP were found almost exclusively in the ipsilateral medial vestibular nucleus and marginal zone. The results suggest that the nitrergic PH neurons control their own firing rate by a NO-mediated facilitation of GABAergic afferents from the ipsilateral medial vestibular nucleus. This self-control mechanism could play an important role in the maintenance of the vestibular balance necessary to generate a stable and adequate eye position signal. PMID:11927688

Change of Retinal Nerve Layer Thickness in Non-Arteritic Anterior Ischemic Optic Neuropathy Revealed by Fourier Domain Optical Coherence Tomography.

PubMed

Han, Mei; Zhao, Chen; Han, Quan-Hong; Xie, Shiyong; Li, Yan

2016-08-01

To examine the changes of non-arteritic anterior ischemic optic neuropathy (NAION) by serial morphometry using Fourier domain optical coherence tomography (FD-OCT). Retrospective study in patients with newly diagnosed NAION (n=33, all unilateral) and controls (n=75 unilateral NAION patients with full contralateral eye vision) who underwent FD-OCT of the optic disk, optic nerve head (ONH), and macula within 1 week of onset and again 1, 3, 6, and 12 months later. The patients showed no improvement in vision during follow-up. Within 1 week of onset, all NAION eyes exhibited severe ONH fiber crowding and peripapillary retinal nerve fiber layer (RNFL) edema. Four had subretinal fluid accumulation and 12 had posterior vitreous detachment (PVD) at the optic disc surface. Ganglion cell complex (GCC) and RNFL thicknesses were reduced at 1 and 3 months (p < 0.05), with no deterioration thereafter. Initial RNFL/GCC contraction magnitude in the superior hemisphere correlated with the severity of inferior visual field deficits. NAION progression is characterized by an initial phase of accelerated RNFL and GCC deterioration. These results reveal that the kinetic change of neural retina in NAION and may have implication on the time window for treatment of NAION. FD-OCT is useful in the evaluation of NAION.

Design of a noninvasive face mask for ocular occlusion in rats and assessment in a visual discrimination paradigm.

PubMed

Hager, Audrey M; Dringenberg, Hans C

2012-12-01

The rat visual system is structured such that the large (>90 %) majority of retinal ganglion axons reach the contralateral lateral geniculate nucleus (LGN) and visual cortex (V1). This anatomical design allows for the relatively selective activation of one cerebral hemisphere under monocular viewing conditions. Here, we describe the design of a harness and face mask allowing simple and noninvasive monocular occlusion in rats. The harness is constructed from synthetic fiber (shoelace-type material) and fits around the girth region and neck, allowing for easy adjustments to fit rats of various weights. The face mask consists of soft rubber material that is attached to the harness by Velcro strips. Eyeholes in the mask can be covered by additional Velcro patches to occlude either one or both eyes. Rats readily adapt to wearing the device, allowing behavioral testing under different types of viewing conditions. We show that rats successfully acquire a water-maze-based visual discrimination task under monocular viewing conditions. Following task acquisition, interocular transfer was assessed. Performance with the previously occluded, "untrained" eye was impaired, suggesting that training effects were partially confined to one cerebral hemisphere. The method described herein provides a simple and noninvasive means to restrict visual input for studies of visual processing and learning in various rodent species.

[Astigmatism after keratoplasty: influence of orthotopic transplantation].

PubMed

Feuerstacke, J; Hellwinkel, O; Naydis, I; Linke, S; Klemm, M

2014-09-01

Patients undergoing corneal transplantation often suffer from postoperative reduced vision due to high astigmatism. This retrospective study analyzed the influence of heterotopic or orthotopic transplantation on astigmatism and visual outcome. In this study 373 eyes of 334 patients were analyzed. Group 1 (OT) contained 186 eyes, which underwent orthotopic transplantation (side of recipient and donor corresponded), whereas group 2 (HT) included 187 heterotopic keratoplasties (donor cornea placed in the recipient's contralateral side). After 1, 3, 6, 12 and 24 months the median of keratometric astigmatism, objective astigmatism, topographic astigmatism and best corrected visual acuity (BCVA) were assessed and compared between groups. The long-term results showed no statistically significant differences regarding keratometric and objective astigmatism, whereas topographic astigmatism differed significantly (p = 0.04) after 3 months. We observed a lower astigmatism of 5.7 dpt (range 3.08-7.78 dpt) in group OT than in the group HT with 7.1 dpt (range 3.9-10.7 dpt). No differences were found at the other time points. The BCVA showed a significantly better effect after 1 month (p = 0.01) in the OT group of 0.2 (0.1-0.3) than in HT group of 0.1 (0.05/0.25). In the postoperative course no additional significant dissimilarities were documented. Heterotopic and orthotopic keratoplasty show no significant long-term differences in astigmatism and visual outcom.

The BRAFT1799A mutation is not associated with occult contralateral carcinoma in patients with unilateral papillary thyroid microcarcinoma.

PubMed

Wan, Han-Feng; Zhang, Bin; Yan, Dan-Gui; Xu, Zhen-Gang

2015-01-01

The phenomenon of occult carcinoma maybe observed in patients with clinically unilateral papillary thyroid microcarcinoma (PTMC). Although many studies have reported that the BRAFT1799A mutation is associated with aggressive PTMC, the relationship between BRAFT1799A mutation and occult carcinoma is unclear. The aim of this study was to investigate the risk factors, including BRAFT1799A mutation, for occult contralateral carcinoma in clinically unilateral PTMC accompanied by benign nodules in the contralateral lobe. From January 2011 to December 2013,we prospectively enrolled 89 consecutive PTMC patients with clinically unilateral carcinoma accompanied by benign nodules in the contralateral lobe who received a total thyroidectomy and cervical lymph node dissection. BRAFT1799A mutation was tested by pyrosequencing on postoperative paraffin specimens. The frequency and predictive factors for occult contralateral carcinoma were analyzed with respect to the following variables: age, gender, family history, tumor size, presence of Hashimoto thyroiditis, extrathyroidal extension, central lymph node metastasis, multifocality of primary tumor, or BRAFT1799A mutation. A total of 36 patients (40.4%) had occult PTMC in the contralateral lobe. The median diameter of the occult tumors was 0.33±0.21 cm. The BRAFT1799A mutation was found in 38 cases (42.7%). According to the univariate analysis, there were no significant differences between the presence of occult contralateral carcinoma and age, gender, family history, tumor size, presence of Hashimoto thyroiditis, extrathyroidal extension, central lymph node metastasis, multifocality of primary tumor, or BRAFT1799A mutation. Using current methods, it is difficult to preoperatively identify patients with PTMC, and further research is needed to determine predictive factors for the presence of occult contralateral carcinoma in patients with unilateral PTMC.

Initial Localization of the Memory Trace for a Basic Form of Learning

NASA Astrophysics Data System (ADS)

McCormick, David A.; Clark, Gregory A.; Lavond, David G.; Thompson, Richard F.

1982-04-01

Electrophysiological recording of neuronal unit activity during paired training trials from various regions of the ipsilateral cerebellum in rabbits well trained in the classically conditioned eyelid/nictitating membrane response have revealed both stimulus-evoked responses and responses that form an amplitude/temporal model of the learned behavioral response. Ablation of the ipsilateral, lateral cerebellum completely and permanently abolished the behavioral conditioned response in well-trained animals but had no effect at all on the unconditioned reflex response. In marked contrast, conditioned responses were easily trained in the eye contralateral to the cerebellar lesion. We suggest that at least part of the essential neuronal plasticity that codes the learned response may be localized to the cerebellum.

Transmission Electron Microscopy Analysis of Epithelial Basement Membrane Repair in Rabbit Corneas With Haze

PubMed Central

Torricelli, Andre A. M.; Singh, Vivek; Agrawal, Vandana; Santhiago, Marcony R.; Wilson, Steven E.

2013-01-01

Purpose. To assess the ultrastructure of the epithelial basement membrane using transmission electron microscopy (TEM) in rabbit corneas with and without subepithelial stroma opacity (haze). Methods. Two groups of eight rabbits each were included in this study. Photorefractive keratectomy (PRK) was performed using an excimer laser. The first group had −4.5-diopter (−4.5D) PRK and the second group had −9.0D PRK. Contralateral eyes were unwounded controls. Rabbits were sacrificed at 4 weeks after surgery. Immunohistochemical analysis was performed to detect the myofibroblast marker α-smooth muscle actin (SMA). TEM was performed to analyze the ultrastructure of the epithelial basement membrane and stroma. Results. At 4 weeks after PRK, α-SMA+ myofibroblasts were present at high density in the subepithelial stroma of rabbit eyes that had −9.0D PRK, along with prominent disorganized extracellular matrix, whereas few myofibroblasts and little disorganized extracellular matrix were noted in eyes that had −4.5D PRK. The epithelial basement membrane was irregular and discontinuous and lacking typical morphology in all corneas at 1 month after −9D PRK compared to corneas at 1 month in the −4.5D PRK group. Conclusions. The epithelial basement membrane acts as a critical modulator of corneal wound healing. Structural and functional defects in the epithelial basement membrane correlate to both stromal myofibroblast development from precursor cells and continued myofibroblast viability, likely through the modulation of epithelial–stromal interactions mediated by cytokines. Prolonged stromal haze in the cornea is associated with abnormal regeneration of the epithelial basement membrane. PMID:23696606

[Anatomical and functional results of macular hole surgery with internal limiting membrane peeling after 10-year follow-up].

PubMed

Foveau, P; Conart, J-B; Hubert, I; Selton, J; Berrod, J-P

2016-09-01

To evaluate the anatomical and functional results of macular hole surgery with internal limiting membrane (ILM) peeling after 10 years follow-up. Monocentric retrospective study of patients who had undergone macular hole surgery between 2003 and 2005 in the Nancy University Medical Center and still followed in the department in 2014. All patients underwent pars plana vitrectomy and ILM peeling without staining. Clinical examination at ten years including determination of best-corrected visual acuity (BCVA), evaluation of quality of life and spectral domain optical coherence tomography was performed. Four men and six women with mean age of 64±8 years were included. The mean diameter of the MH was 395±133μm. The mean best corrected visual acuity improved significantly from 0.90±0.22 logMAR to 0.14±0.14 logMAR after 10 years with a satisfactory quality of life in 90 % of patients. The integrity of the IS/OS layer was preserved in 9 eyes. Inner retinal dimples located in the temporal quadrant related to ILM peeling initiation were observed in 8 eyes. No significant RNFL or ganglion cell complex changes were found compared to the contralateral eye. Macular hole surgery with ILM peeling in this series resulted in a visual acuity gain of 8 ETDRS lines and persistent improvement in quality of life after a 10-year follow-up. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Treatment of conjunctival lymphomas by beta-ray brachytherapy using a strontium-90-yttrium-90 applicator.

PubMed

Regueiro, C A; Valcárcel, F J; Romero, J; de la Torre, A

2002-12-01

We reviewed the outcome of the 10 patients (13 eyes) with localized, biopsy-proven, low-grade lymphoma of the conjunctiva treated at our Department between 1988 and 1997. All patients were treated by beta-ray brachytherapy using a bidirectional 90Sr-90Y ophthalmic applicator (Applicator SIA 2, Amersham plc). Total doses, prescribed at the surface of the applicator, varied between 40 Gy and 80 Gy. With a median follow-up of 78 months (range: 14 to 146 months), seven patients remained with no evidence of relapse (67.5% 10 year disease free survival). Local control was achieved in 10 out of 13 eyes (76.9%). Two of the three local relapses were marginal. One of these three patients also developed a metachronous lymphoma in the contralateral conjunctiva. These three patients underwent a second course of brachytherapy with 90Sr/90Y and remained free of second relapse 109, 68 and 33 months after salvage therapy. No cases of systemic relapse were observed. Late (LENT-SOMA) complications were of grade 2 in five eyes, of grade 3 in one eye and of grade 4 in one eye. Late complications of grade 2 or higher were observed in one out of five patients (20%) treated with doses lower or equal to 50 Gy and in six out of eight patients (75%) treated with doses higher than 50 Gy (P=0.086). Our data indicates that beta-ray brachytherapy was ultimately able to control most conjunctival lymphomas but carried a risk of late complications and marginal relapses that was possibly higher than the rates reported for other radiotherapy techniques.

Mobile-bearing medial unicompartmental knee arthroplasty restores limb alignment comparable to that of the unaffected contralateral limb

PubMed Central

Mullaji, Arun B; Shah, Siddharth; Shetty, Gautam M

2017-01-01

Background and purpose — Medial unicompartmental knee arthroplasty (UKA) is undertaken in patients with a passively correctable varus deformity. We investigated whether restoration of natural soft tissue tension would result in a lower limb alignment similar to that of the contralateral unaffected lower limb after mobile-bearing medial UKA. Patients and methods — In this retrospective study, hip-knee-ankle (HKA) angle, position of the weight-bearing axis (WBA), and knee joint line obliquity (KJLO) after mobile-bearing medial UKA was compared with that of the unaffected (clinically and radiologically) contralateral lower limb in 123 patients. Results — Postoperatively, HKA angle was restored to within ±3° of the contralateral lower limb in 87% of the patients and the WBA passed within ±1 Kennedy and White’s tibial zone of the unaffected contralateral lower limb in 95% of the patients. The mean KJLO in the operated limbs was not significantly different from that in the unaffected lower limbs (p = 0.07) and the KJLO in the operated limb was restored to within ±3° of that in the contralateral lower limb in 96% of the patients. Interpretation — Lower limb alignment and knee joint line obliquity after mobile-bearing medial UKA were comparable to that of the unaffected contralateral limb in most patients. Comparison with the contralateral unaffected lower limb is a reliable method for evaluation and validation of limb mechanical alignment after mobile-bearing medial UKA. PMID:27794622

Dorsolateral prefrontal cortex bridges bilateral primary somatosensory cortices during cross-modal working memory.

PubMed

Zhao, Di; Ku, Yixuan

2018-05-01

Neural activity in the dorsolateral prefrontal cortex (DLPFC) has been suggested to integrate information from distinct sensory areas. However, how the DLPFC interacts with the bilateral primary somatosensory cortices (SIs) in tactile-visual cross-modal working memory has not yet been established. In the present study, we applied single-pulse transcranial magnetic stimulation (sp-TMS) over the contralateral DLPFC and bilateral SIs of human participants at various time points, while they performed a tactile-visual delayed matching-to-sample task with a 2-second delay. sp-TMS over the contralateral DLPFC or the contralateral SI at either an sensory encoding stage [i.e. 100 ms after the onset of a vibrotactile sample stimulus (200-ms duration)] or an early maintenance stage (i.e. 300 ms after the onset), significantly impaired the accuracy of task performance; sp-TMS over the contralateral DLPFC or the ipsilateral SI at a late maintenance stage (1600 ms and 1900 ms) also significantly disrupted the performance. Furthermore, at 300 ms after the onset of the vibrotactile sample stimulus, there was a significant correlation between the deteriorating effects of sp-TMS over the contralateral SI and the contralateral DLPFC. These results imply that the DLPFC and the bilateral SIs play causal roles at distinctive stages during cross-modal working memory, while the contralateral DLPFC communicates with the contralateral SI in the early delay, and cooperates with the ipsilateral SI in the late delay. Copyright © 2018 Elsevier B.V. All rights reserved.

Surgical treatment of dry eye syndrome: conjunctival graft of the minor salivary gland.

PubMed

Güerrissi, Jorge Orlando; Belmonte, Javier

2004-01-01

Despite the availability of efficient tear substitutes, many patients with dry eye syndrome experience severe corneal injuries and a subsequent loss of vision. Surgical techniques using mayor salivary glands to provide a substitute for tears have been reported; with this technique the drainage of saliva goes into the conjunctival fornix, permitting corneal and conjunctival humidification. The authors describe a new surgical approach in which minor salivary glands are autotransplanted into the conjunctival fornix by means of a graft of the intraoral mucosa-transporting salivary glands. This approach was used in a 56-year-old woman with a 2-year history of refractory and pharmacologically untreatable dry eye syndrome caused by Sjögren's syndrome. The right eye had more severe corneal and conjunctival lesions than did the contralateral one, so the treatment was planned in the right eye only. A weekly follow-up during the first 6 months confirmed the significant improvement of dry eye symptoms in the surgically treated eye. Three months after surgery, a biopsy was performed in the minor salivary gland graft, and the histologic findings revealed the presence of glandular acinus, duct with mucin content, and lymphocyte infiltration. The significant improvement obtained in this patient suggests that the secretion from the grafted salivary minor glands was better in promoting homeostasis of the ocular surface than are artificial tears. This may be explained by: (1) The lacrimal and salivary secretions contain biologically active constituents that may protect from infection and promote normal growth epithelium; (2) The secreted mucin is thought to coat the epithelial surface, reducing the high surface tension of the eye wetted by aqueous tears; (3) The thick secretions of the minor gland might act in reducing the evaporation of the underlying tear layer and form a hydrophobic barrier along the lid margin that can retain the lid margin tear string and prevent its flow onto the skin. Minor gland salivary autotransplant is a new surgical technique with effectiveness demonstrated in one patient, but the scientific explanation is not clear; additional experience with more cases could confirm the initial success.

Relationship of unilateral total hip arthroplasty (THA) to contralateral and ipsilateral knee joint degeneration - a longitudinal 3T MRI study from the Osteoarthritis Initiative (OAI).

PubMed

Jungmann, P M; Nevitt, M C; Baum, T; Liebl, H; Nardo, L; Liu, F; Lane, N E; McCulloch, C E; Link, T M

2015-07-01

To evaluate the association of prevalent unilateral total hip arthroplasty (THA) with worsening of degenerative knee abnormalities and clinical outcomes in the ipsilateral and contralateral knee. Both knees of 30 individuals in the Osteoarthritis Initiative (OAI) with unilateral THA (n = 14 left, n = 16 right) at baseline were assessed at baseline and at 4-year follow-up for Whole-organ MR Imaging Scores (WORMS), cartilage T2 relaxation times (only available for right knees), Western Ontario and McMasters Universities Arthritis Index (WOMAC) scores and upper leg isometric strength. Right knees of 30 individuals without THA were analyzed as controls. Contralateral knees were compared to ipsilateral knees with paired t-tests and to control knees with multivariate regression analysis adjusting for covariates. In paired analyses, compared to ipsilateral knees, contralateral knees had higher WORMS total (P = 0.008) and cartilage scores (P = 0.007) at baseline. Over 4 years contralateral knees worsened more on WORMS total score (P = 0.008). Cartilage T2 values were higher in knees contralateral to the THA (baseline, P = 0.02; follow-up, P < 0.001). Contralateral knees had greater declines in knee extension strength (P = 0.04) and had a trend for greater worsening in WOMAC pain, stiffness, function and total scores (P = 0.04-0.09). Similar results were found comparing contralateral knees with control knees in multivariate regression models. Prevalent unilateral THA is associated with an greater progression of degenerative findings for the knee contralateral to THA. Copyright © 2015 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Poor WOMAC scores in contralateral knee negatively impact TKA outcomes: data from the osteoarthritis initiative.

PubMed

Kahn, Timothy L; Soheili, Aydin C; Schwarzkopf, Ran

2014-08-01

While total knee arthroplasty (TKA) has been shown to have excellent outcomes, a significant proportion of patients experience relatively poor post-operative function. In this study, we test the hypothesis that the level of osteoarthritic symptoms in the contralateral knee at the time of TKA is associated with poorer post-operative outcomes in the operated knee. Using longitudinal cohort data from the Osteoarthritis Initiative (OAI), we included 171 patients who received a unilateral TKA. We compared pre-operative Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores in the contralateral knee to post-operative WOMAC scores in the index knee. Pre-operative contralateral knee WOMAC scores were associated with post-operative index knee WOMAC Total scores, indicating that the health of the pre-operative contralateral knee is a significant factor in TKA outcomes. Copyright © 2014 Elsevier Inc. All rights reserved.

Preference for a fixed combination of brinzolamide/timolol versus dorzolamide/timolol among patients with open-angle glaucoma or ocular hypertension.

PubMed

Sanseau, Ana; Sampaolesi, Juan; Suzuki, Emilio Rintaro; Lopes, Joao Franca; Borel, Hector

2013-01-01

To assess ocular discomfort upon instillation and patient preference for brinzolamide/timolol relative to dorzolamide/timolol, in patients with open-angle glaucoma or ocular hypertension. This was a multicenter, prospective, patient-masked, randomized, crossover study. On day 0, patients received one drop of brinzolamide/timolol in one eye and one drop of dorzolamide/timolol in the contralateral eye. On day 1, patients were randomly assigned to receive one drop of either brinzolamide/timolol or dorzolamide/timolol in both eyes; on day 2, patients received one drop of the alternate treatment in both eyes. Measures included a patient preference question on day 2 (primary) and mean ocular discomfort scale scores on days 1 and 2 (secondary). Safety assessments included adverse events, visual acuity, and slit-lamp examinations. Of 120 patients who enrolled, 115 completed the study. Of these, 112 patients instilled both medications and expressed a study medication preference on day 2. A significantly greater percentage preferred brinzolamide/timolol to dorzolamide/timolol (67.0% versus 30.4%; P < 0.001). The ocular discomfort (expressed as mean [standard deviation]) with brinzolamide/timolol was significantly lower than with dorzolamide/timolol (day 2:1.9 [2.3] versus 3.7 [2.8], respectively [P = 0.0003]; both days combined: 2.1 [2.5] versus 3.5 [2.9], respectively [P = 0.00014]). On day 1, five patients receiving brinzolamide/timolol reported five nonserious adverse events (AEs): flu (n = 1), bitter taste (n = 2), and headache (n = 2). Four events, bitter taste (two events) and headache (two events), were considered related to brinzolamide/timolol. Events were mild in intensity, except bitter taste of moderate intensity reported by one patient. No AEs were reported at day 2. All AEs resolved without additional treatment. No clinically relevant changes from baseline were observed in best-corrected visual acuity or slit-lamp examinations of ocular signs. Patients had less discomfort with brinzolamide/timolol than with dorzolamide/timolol, and more expressed a preference for brinzolamide/timolol. Both treatments were generally safe and well tolerated.

Risk factor of contralateral radiculopathy following microendoscopy-assisted minimally invasive transforaminal lumbar interbody fusion.

PubMed

Yang, Yang; Liu, Zhong-Yu; Zhang, Liang-Ming; Dong, Jian-Wen; Xie, Pei-Gen; Chen, Rui-Qiang; Yang, Bu; Liu, Chang; Liu, Bin; Rong, Li-Min

2017-12-08

Microendoscopy-assisted minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is an advantageous method for treating lumbar degenerative disease; however, some patients show contralateral radiculopathy postoperatively. This study aims to investigate its risk factor. A total of 130 cases who underwent microendoscopy-assisted MIS-TLIF at L4-5 level were divided into symptomatic and asymptomatic groups according to the presence of postoperative contralateral radiculopathy. Both preoperative and postoperative radiographic parameters, as well as their changes were compared between the two groups, including lumbar lordosis (LL), surgical segmental angle (SSA), disc height (DH), contralateral foramen area (CFA) and contralateral canal area (CCA). Screw breach on contralateral L4 pedicle and decompression method (ipsilateral or bilateral canal decompression through unilateral route) were also analyzed as potential risk factors. Receiver operating characteristic (ROC) curve was drawn for the risk factor to determine the optimal threshold for predicting postoperative contralateral radiculopathy. Besides, clinical outcome assessment, involving Visual Analog Score (VAS) for back and leg, Japanese Orthopaedics Association Score (JOA) and Oswestry Disability Index (ODI), was also compared between the two groups before surgery and at final follow-up (at least 3 months after the surgery for asymptomatic patients or final treatments of contralateral radiculopathy for symptomatic cases). Postoperative contralateral radiculopathy occurred in 11 (8.5%) of the 130 patients. Both preoperative and postoperative CFA as well as its change were significantly decreased in symptomatic group compared with asymptomatic group (all P < 0.05). For the remaining four parameters (LL, SSA, DH, CCA), their preoperative, postoperative and change values showed no statistical difference between the two groups (all P > 0.05). Neither screw breach nor decompression method revealed statistical association with this complication (both P > 0.05). Based on ROC curve, the optimal threshold of preoperative CFA was 0.76 cm 2 . At final follow-up, significant improvement in VAS (back and leg), JOA and ODI was observed in both groups compared with preoperative baseline (all P < 0.05), while no difference was found between the two groups (all P > 0.05). Preoperative contralateral foramen stenosis is the risk factor of contralateral radiculopathy following microendoscopy-assisted MIS-TLIF. If preoperative CFA at L4-5 level is not larger than 0.76 cm 2 , prophylactic measures, including both indirect and direct decompression of contralateral foramen, are recommended.

Sustained Neuroprotection From a Single Intravitreal Injection of PGJ2 in a Nonhuman Primate Model of Nonarteritic Anterior Ischemic Optic Neuropathy

PubMed Central

Miller, Neil R.; Johnson, Mary A.; Nolan, Theresa; Guo, Yan; Bernstein, Alexander M.; Bernstein, Steven L.

2014-01-01

Purpose. Prostaglandin J2 (PGJ2) is neuroprotective in a murine model of nonarteritic anterior ischemic optic neuropathy (NAION). After assessing for potential toxicity, we evaluated the efficacy of a single intravitreal (IVT) injection of PGJ2 in a nonhuman primate model of NAION (pNAION). Methods. We assessed PGJ2 toxicity by administering it as a single high-dose intravenous (IV) injection, consecutive daily high-dose IV injections, or a single IVT injection in one eye of five adult rhesus monkeys. To assess efficacy, we induced pNAION in one eye of five adult male rhesus monkeys using a laser-activated rose bengal induction method. We then injected the eye with either PGJ2 or phosphate-buffered saline (PBS) intravitreally immediately or 5 hours post induction. We performed a clinical assessment, optical coherence tomography, electrophysiological testing, fundus photography, and fluorescein angiography in all animals prior to induction and at 1 day, 1 week, 2 weeks, and 4 weeks after induction. Following analysis of the first eye, we induced pNAION in the contralateral eye and then injected either PGJ2 or PBS. We euthanized all animals 5 weeks after final assessment of the fellow eye and performed both immunohistochemical and light and electron microscopic analyses of the retina and optic nerves. Results. Toxicity: PGJ2 caused no permanent systemic toxicity regardless of the amount injected or route of delivery, and there was no evidence of any ocular toxicity with the dose of PGJ2 used in efficacy studies. Transient reduction in the amplitudes of the visual evoked potentials and the N95 component of the pattern electroretinogram (PERG) occurred after both IV and IVT administration of high doses of PGJ2; however, the amplitudes returned to normal in all animals within 1 week. Efficacy: In all eyes, a single IVT dose of PGJ2 administered immediately or shortly after induction of pNAION resulted in a significant reduction of clinical, electrophysiological, and histological damage compared with vehicle-injected eyes (P = 0.03 for both VEP and PERG; P = 0.05 for axon counts). Conclusions. In nonhuman primates, PGJ2 administered either intravenously or intravitreally produces no permanent toxicity at even four times the dose given for neuroprotection. Additionally, a single IVT dose of PGJ2 is neuroprotective when administered up to 5 hours after induction of pNAION. PMID:25298416

Status of the contralateral rotator cuff in patients undergoing rotator cuff repair.

PubMed

Ro, Kyung-Han; Park, Jong-Hoon; Lee, Soon-Hyuck; Song, Dong-Ik; Jeong, Ha-Joon; Jeong, Woong-Kyo

2015-05-01

Although the prevalence of rotator cuff tear (RCT) in the general population has been analyzed, little information is available on the status of the opposite-side rotator cuff in patients who have undergone arthroscopic rotator cuff repair. To identify the characteristics of the contralateral shoulder and to identify factors associated with RCT of the contralateral shoulder in patients who underwent surgery for symptomatic RCT. The hypothesis was that the prevalence of RCT in the contralateral shoulder would be higher in patients with increasingly larger cuff tears requiring surgical intervention. Case series; Level of evidence, 4. The study cohort consisted of 140 patients with RCT who underwent arthroscopic rotator cuff repair. Opposite-shoulder rotator cuff tendons of all patients were evaluated by ultrasonography. Demographic information and factors related to contralateral RCT were investigated, and risk factors associated with contralateral RCT were assessed. Of the 140 patients who underwent arthroscopic rotator cuff repair, 54 (38.6%) had an RCT of the contralateral shoulder. Of 51 patients with partial-thickness and small-sized full-thickness tears of the operated shoulder, 35 (68.6%) had no tears; 14 (27.5%) had partial-thickness tears; and 2 (3.9%) had small-sized full-thickness tears of the contralateral shoulder. Of 75 patients with medium-sized full-thickness tears, 43 (57.3%) had no tears; 12 (16%) had partial-thickness tears; and 20 (26.7%) had full-thickness tears of the contralateral shoulder. Of 14 patients with large to massive full-thickness tears, 8 (57.1%) had no tears; 1 (7.1%) had a partial-thickness tear; and 5 (35.7%) had full-thickness tears of the contralateral shoulder. The prevalence of RCT of the contralateral shoulder differed significantly among groups classified by tear size (P=.007). The mean American Shoulder and Elbow Surgeons score was significantly lower in the RCT than in the nontear group (55.8±16.9 vs 61.6±13.3; P=.03). Of 29 subjects with symptomatic tears involving the nondominant arm, 17 (58.6%) had contralateral asymptomatic RCT, compared with 37 of 111 (33.3%) subjects with symptomatic tears involving the dominant arm (P=.007). The prevalence of RCT of the contralateral asymptomatic shoulder tends to be higher in patients with more symptomatic RCT on one side, in patients with medium-sized or larger RCT in the operated shoulder, and in patients with symptomatic RCT in the nondominant arm. © 2015 The Author(s).

Diagnosing the occult contralateral inguinal hernia.

PubMed

Koehler, R H

2002-03-01

The incidence of bilateral inguinal hernias reported for total extra peritoneal (TEP) laparoscopic hernia repair, which reaches 45%, appears to be higher than that seen in studies of transabdominal laparoscopic and open repair. Given the unique ability of diagnostic laparoscopy to diagnose occult contralateral hernias (OCH) accurately, this study looked at how concurrent transabdominal diagnostic laparoscopy (TADL) would influence planned TEP repairs. A prospective study oF 100 consecutive TEP cases was conducted. All patients had diagnostic laparoscopy via a 5-mm 45 degrees scope through an umbilical incision with 15 mmHg of pneumoperitoneum, followed by laparoscopic TEPrepair. A contralateral occult hernia was diagnosed and repaired if a true peritoneal eventration through the inguinal region was observed. Among the 100 patients, preoperative diagnosis suggested 31 bilateral hernias (31%), whereas TADL confirmed 25 bilateral hernias (25%). Of these 25 bilateral hernias, TADL confirmed 16 that had been diagnosed preoperatively (64%), but excluded 15 contralateral hernias that were incorrectly diagnosed (37%). Transabdominal diagnostic laparoscopy found nine OCHs, representing 36% of all bilateral hernias and 13% of the 69 preoperatively determined unilateral hernias. The preoperative physician examination false-negative rate for contralateral hernias was 36%, and the false-positive rate was 37%. In 26 cases (26%), TADL changed the operative approach. In this study, patients believed to have unilateral inguinal hernias had OCHs in 13% of cases when examined by TADL. The actual bilateral hernia incidence was 25%, with a 37% false-positive rate for preoperatively diagnosed bilateral hernias. The high rate of bilateral hernias reported by the TEP approach alone suggests that some OCH findings may be an artifact of the TEP dissection. However, failure to search for an OCH could result in up to 13% of patients subsequently requiring a second repair. Because some surgeons are concerned about unnecessary TEP dissection of the asymptomatic contralateral side, the approach described here may offer a solution to accurate diagnosis of the contralateral inguinal region during planned laparoscopic TEP hernia repair.

Fractionated Stereotactic Radiotherapy in Patients With Optic Nerve Sheath Meningioma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paulsen, Frank, E-mail: frank.paulsen@med.uni-tuebingen.de; Doerr, Stefan; Wilhelm, Helmut

Purpose: To evaluate the effectiveness of fractionated stereotactic radiotherapy (SFRT) in the treatment of optic nerve sheath meningioma (ONSM). Methods and Materials: Between 1993 and 2005, 109 patients (113 eyes) with primary (n = 37) or secondary (n = 76) ONSM were treated according to a prospective protocol with SFRT to a median dose of 54 Gy. All patients underwent radiographic, ophthalmologic, and endocrine analysis before and after SFRT. Radiographic response, visual control, and late side effects were endpoints of the analysis. Results: Median time to last clinical, radiographic, and ophthalmologic follow up was 30.2 months (n = 113), 42.7more » months (n = 108), and 53.7 months (n = 91), respectively. Regression of the tumor was observed in 5 eyes and progression in 4 eyes, whereas 104 remained stable. Visual acuity improved in 12, deteriorated in 11, and remained stable in 68 eyes. Mean visual field defects reduced from 33.6% (n = 90) to 17.8% (n = 56) in ipsilateral and from 10% (n = 94) to 6.7% (n = 62) in contralateral eyes. Ocular motility improved in 23, remained stable in 65, and deteriorated in 3 eyes. Radiographic tumor control was 100% at 3 years and 98% at 5 years. Visual acuity was preserved in 94.8% after 3 years and in 90.9% after 5 years. Endocrine function was normal in 90.8% after 3 years and in 81.3% after 5 years. Conclusions: SFRT represents a highly effective treatment for ONSM. Interdisciplinary counseling of the patients is recommended. Because of the high rate of preservation of visual acuity we consider SFRT the standard approach for the treatment of ONSM. Prolonged observation is warranted to more accurately assess late visual impairment. Moderate de-escalation of the radiation dose might improve the preservation of visual acuity and pituitary gland function.« less

Effect of ligamenta flava hypertrophy on lumbar disc herniation with contralateral symptoms and signs: a clinical and morphometric study

PubMed Central

Yildizhan, Ahmet; Atar, Elmas K.; Yaycioglu, Soner; Gocmen-Mas, Nuket; Yazici, Canan

2010-01-01

Introduction The purpose of this study was to determine whether ligamentum flavum hypertrophy among disc herniated patients causes contralateral pain symptoms. For this reason we measured the thickness of the ligament in disc herniated patients with ipsilateral or contralateral symptoms. Material and methods Two hundred disc herniated patients with ipsilateral symptoms as group I were compared with five disc herniated patients with only contralateral symptoms as group II. Ligamenta flava thicknesses and spinal canal diameters of both groups were measured on magnetic resonance imaging (MRI) with a micro-caliper. Results Both groups underwent surgery only on the disc herniated side. The total thicknesses of the ligamenta flava in group II was thicker than in group I. There was no spinal stenosis in either group and no significance difference between the groups. Statistically significant differences were found for both ipsilateral and contralateral thickness of the ligament flava in both groups. We also compared thickness of the ligamenta flava for each level of disc herniation in group I; ligamenta flava hypertrophy was more common at L3-L4 and L4-L5 levels of vertebrae in females. Conclusions Aetiology of contralateral sciatica among disc herniated patients may be related to hypertrophy of the ligamenta flava, especially on the opposite side. Surgical approaches of the disc herniated side alone may be sufficient for a good outcome. PMID:22371809

Computed tomography demonstrates abnormalities of contralateral ear in subjects with unilateral sensorineural hearing loss.

PubMed

Marcus, Sonya; Whitlow, Christopher T; Koonce, James; Zapadka, Michael E; Chen, Michael Y; Williams, Daniel W; Lewis, Meagan; Evans, Adele K

2014-02-01

Prior studies have associated gross inner ear abnormalities with pediatric sensorineural hearing loss (SNHL) using computed tomography (CT). No studies to date have specifically investigated morphologic inner ear abnormalities involving the contralateral unaffected ear in patients with unilateral SNHL. The purpose of this study is to evaluate contralateral inner ear structures of subjects with unilateral SNHL but no grossly abnormal findings on CT. IRB-approved retrospective analysis of pediatric temporal bone CT scans. 97 temporal bone CT scans, previously interpreted as "normal" based upon previously accepted guidelines by board certified neuroradiologists, were assessed using 12 measurements of the semicircular canals, cochlea and vestibule. The control-group consisted of 72 "normal" temporal bone CTs with underlying SNHL in the subject excluded. The study-group consisted of 25 normal-hearing contralateral temporal bones in subjects with unilateral SNHL. Multivariate analysis of covariance (MANCOVA) was then conducted to evaluate for differences between the study and control group. Cochlea basal turn lumen width was significantly greater in magnitude and central lucency of the lateral semicircular canal bony island was significantly lower in density for audiometrically normal ears of subjects with unilateral SNHL compared to controls. Abnormalities of the inner ear were present in the contralateral audiometrically normal ears of subjects with unilateral SNHL. These data suggest that patients with unilateral SNHL may have a more pervasive disease process that results in abnormalities of both ears. The findings of a cochlea basal turn lumen width disparity >5% from "normal" and/or a lateral semicircular canal bony island central lucency disparity of >5% from "normal" may indicate inherent risk to the contralateral unaffected ear in pediatric patients with unilateral sensorineural hearing loss. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Stronger efferent suppression of cochlear neural potentials by contralateral acoustic stimulation in awake than in anesthetized chinchilla.

PubMed

Aedo, Cristian; Tapia, Eduardo; Pavez, Elizabeth; Elgueda, Diego; Delano, Paul H; Robles, Luis

2015-01-01

There are two types of sensory cells in the mammalian cochlea, inner hair cells, which make synaptic contact with auditory-nerve afferent fibers, and outer hair cells that are innervated by crossed and uncrossed medial olivocochlear (MOC) efferent fibers. Contralateral acoustic stimulation activates the uncrossed efferent MOC fibers reducing cochlear neural responses, thus modifying the input to the central auditory system. The chinchilla, among all studied mammals, displays the lowest percentage of uncrossed MOC fibers raising questions about the strength and frequency distribution of the contralateral-sound effect in this species. On the other hand, MOC effects on cochlear sensitivity have been mainly studied in anesthetized animals and since the MOC-neuron activity depends on the level of anesthesia, it is important to assess the influence of anesthesia in the strength of efferent effects. Seven adult chinchillas (Chinchilla laniger) were chronically implanted with round-window electrodes in both cochleae. We compared the effect of contralateral sound in awake and anesthetized condition. Compound action potentials (CAP) and cochlear microphonics (CM) were measured in the ipsilateral cochlea in response to tones in absence and presence of contralateral sound. Control measurements performed after middle-ear muscles section in one animal discarded any possible middle-ear reflex activation. Contralateral sound produced CAP amplitude reductions in all chinchillas, with suppression effects greater by about 1-3 dB in awake than in anesthetized animals. In contrast, CM amplitude increases of up to 1.9 dB were found in only three awake chinchillas. In both conditions the strongest efferent effects were produced by contralateral tones at frequencies equal or close to those of ipsilateral tones. Contralateral CAP suppressions for 1-6 kHz ipsilateral tones corresponded to a span of uncrossed MOC fiber innervation reaching at least the central third of the chinchilla cochlea.

Activity of neurons in area 6 of the cat during fixation and eye movements.

PubMed

Weyand, T G; Gafka, A C

1998-01-01

We studied the visuomotor properties of 645 neurons in area 6 of five cats trained in oculomotor tasks. The area we recorded from corresponds well with territories believed to contain the feline homologue of the frontal eye fields observed in primates. Despite an expectation that cells with pre-saccadic activity would be common, only a small fraction (approximately 5%) of the cells displayed activity that could be linked to subsequent saccadic eye movements. These pre-motor cells appeared to be distributed over a broad region of cortex mixed in with other cell types. As in primates, saccade-related activity tended to occur only during "purposeful" saccades. At least 30% (208/645) of the neurons were visual, with many of these cells possessing huge receptive fields that appeared to include the entire contralateral visual field. Visual responsiveness was generally attenuated by fixation during the oculomotor tasks. Although attentional mechanisms may play a role in this attenuation, this cortical area also exhibits powerful lateral interactions in which spatially displaced visual stimuli suppress each other. Most cells, visually responsive or not, were affected by fixation. Nearly equal proportions of cells showed increases or decreases in activity during fixation. For many of the cells affected by fixation, the source of this modulation appears to reflect cognitive, rather than sensory or motor processes. This included cells that showed anticipatory activity, and cells that responded to the reward only when it was presented in the context of the task. Based on the paucity of pre-saccadic neurons, it would be difficult to conclude that this region of cortex in the cat is homologous to the frontal eye fields of the monkey. However, when considered in the context of differences in the oculomotor habits of these two animals, we believe the homology fits. In addition to pre-motor neurons, the properties of several other cell types found in this area could contribute to the control of gaze.

Sensitivity to Pigment-Dispersing Factor (PDF) Is Cell-Type Specific among PDF-Expressing Circadian Clock Neurons in the Madeira Cockroach.

PubMed

Gestrich, Julia; Giese, Maria; Shen, Wen; Zhang, Yi; Voss, Alexandra; Popov, Cyril; Stengl, Monika; Wei, HongYing

2018-02-01

Transplantation studies have pinpointed the circadian clock of the Madeira cockroach to the accessory medulla (AME) of the brain's optic lobes. The AME is innervated by approximately 240 adjacent neuropeptidergic neurons, including 12 pigment-dispersing factor (PDF)-expressing neurons anterior to the AME (aPDFMEs). Four of the aPDFMEs project contralaterally, controlling locomotor activity rhythms of the night-active cockroach. The present in vitro Ca 2+ imaging analysis focuses on contralaterally projecting AME neurons and their responses to PDF, GABA, and acetylcholine (ACh). First, rhodamine-dextran backfills from the contralateral optic stalk identified contralaterally projecting AME neurons, which were then dispersed in primary cell cultures. After characterization of PDF, GABA, and ACh responses, PDF immunocytochemistry identified ipsilaterally and contralaterally projecting PDFMEs. All PDF-sensitive clock neurons, PDF-immunoreactive clock neurons, and the majority of ipsilaterally and contralaterally projecting cells were excited by ACh. GABA inhibited all PDF-expressing clock neurons, and about half of other ipsilaterally projecting and most contralaterally projecting clock neurons. For the first time, we identified PDF autoreceptors in PDF-secreting cockroach circadian pacemakers. The medium-sized aPDFMEs and all other contralaterally projecting PDF-sensitive clock cells were inhibited by PDF. The ipsilaterally remaining small PDF-sensitive clock cells were activated by PDF. Only the largest aPDFME did not express PDF autoreceptors. We hypothesize that opposing PDF signaling generates 2 different ensembles of clock cells with antiphasic activity, regulating and maintaining a constant phase relationship between rest and activity cycles of the night-active cockroach.

Lifetime Costs of Prophylactic Mastectomies and Reconstruction versus Surveillance.

PubMed

Mattos, David; Gfrerer, Lisa; Reish, Richard G; Hughes, Kevin S; Cetrulo, Curtis; Colwell, Amy S; Winograd, Jonathan M; Yaremchuk, Michael J; Austen, William G; Liao, Eric C

2015-12-01

The past decade has seen an increasing prevalence of prophylactic mastectomy with decreasing ages of patients treated for breast cancer. Data are limited on the fiscal impacts of contralateral prophylactic mastectomy trends, and no study has compared bilateral prophylactic mastectomy with reconstruction to surveillance in high-risk patients. Lifetime third-party payer costs over 30 years were estimated with 2013 Medicare reimbursement rates. Costs were estimated for patients choosing contralateral or bilateral prophylactic mastectomy versus surveillance, with immediate reconstructions using a single-stage implant, tissue expander, or perforator-based free flap approach. Published cancer incidence rates predicted the percentage of surveillance patients that would require mastectomies. Sensitivity analyses were conducted that varied cost growth, discount rate, cancer incidence rate, and other variables. Lifetime costs and present values (3 percent discount rate) were estimated. Lifetime prophylactic mastectomy costs were lower than surveillance costs, $1292 to $1993 lower for contralateral prophylactic mastectomy and $15,668 to $21,342 lower for bilateral prophylactic mastectomy, depending on the reconstruction. Present value estimates were slightly higher for contralateral prophylactic mastectomy over contralateral surveillance but still cost saving for bilateral prophylactic mastectomy compared with bilateral surveillance. Present value estimates are also cost saving for contralateral prophylactic mastectomy when the modeled contralateral breast cancer incidence rate is increased to at least 0.6 percent per year. These findings are consistent with contralateral and bilateral prophylactic mastectomy being cost saving in many scenarios, regardless of the reconstructive option chosen. They suggest that physicians and patients should continue to receive flexibility in deciding how best to proceed clinically in each case.

Mirror-image pain after nerve reconstruction in rats is related to enhanced density of epidermal peptidergic nerve fibers.

PubMed

Kambiz, S; Brakkee, E M; Duraku, L S; Hovius, S E R; Ruigrok, T J H; Walbeehm, E T

2015-05-01

Mirror-image pain is a phenomenon in which unprovoked pain is detected on the uninjured contralateral side after unilateral nerve injury. Although it has been implicated that enhanced production of nerve growth factor (NGF) in the contralateral dorsal root ganglion is important in the development of mirror-image pain, it is not known if this is related to enhanced expression of nociceptive fibers in the contralateral skin. Mechanical and thermal sensitivity in the contralateral hind paw was measured at four different time points (5, 10, 20 and 30weeks) after transection and immediate end-to-end reconstruction of the sciatic nerve in rats. These findings were compared to the density of epidermal (peptidergic and non-peptidergic) nerve fibers on the contralateral hind paw. Mechanical hypersensitivity of the contralateral hind paw was observed at 10weeks PO, a time point in which both subgroups of epidermal nerve fibers reached control values. Thermal hypersensitivity was observed with simultaneous increase in the density of epidermal peptidergic nerve fibers of the contralateral hind paw at 20weeks PO. Both thermal sensitivity and the density of epidermal nerve fibers returned to control values 30weeks PO. We conclude that changes in skin innervation and sensitivity are present on the uninjured corresponding side in a transient pain model. Therefore, the contralateral side cannot serve as control. Moreover, the current study confirms the involvement of the peripheral nervous system in the development of mirror-image pain. Copyright © 2015 Elsevier Inc. All rights reserved.

Adaptability of the Immature Ocular Motor Control System: Unilateral IGF-1 Medial Rectus Treatment.

PubMed

Willoughby, Christy L; Fleuriet, Jérome; Walton, Mark M; Mustari, Michael J; McLoon, Linda K

2015-06-01

Unilateral treatment with sustained release IGF-1 to one medial rectus muscle in infant monkeys was performed to test the hypothesis that strabismus would develop as a result of changes in extraocular muscles during the critical period of development of binocularity. Sustained release IGF-1 pellets were implanted unilaterally on one medial rectus muscle in normal infant monkeys during the first 2 weeks of life. Eye position was monitored using standard photographic methods. After 3 months of treatment, myofiber and neuromuscular size, myosin composition, and innervation density were quantified in all rectus muscles and compared to those in age-matched controls. Sustained unilateral IGF-1 treatments resulted in strabismus for all treated subjects; 3 of the 4 subjects had a clinically significant strabismus of more than 10°. Both the treated medial rectus and the untreated ipsilateral antagonist lateral rectus muscles had significantly larger myofibers. No adaptation in myofiber size occurred in the contralateral functionally yoked lateral rectus or in myosin composition, neuromuscular junction size, or nerve density. Sustained unilateral IGF-1 treatment to extraocular muscles during the sensitive period of development of orthotropic eye alignment and binocularity was sufficient to disturb ocular motor development, resulting in strabismus in infant monkeys. This could be due to altering fusion of gaze during the early sensitive period. Serial measurements of eye alignment suggested the IGF-1-treated infants received insufficient coordinated binocular experience, preventing the establishment of normal eye alignment. Our results uniquely suggest that abnormal signaling by the extraocular muscles may be a cause of strabismus.

Adaptability of the Immature Ocular Motor Control System: Unilateral IGF-1 Medial Rectus Treatment

PubMed Central

Willoughby, Christy L.; Fleuriet, Jérome; Walton, Mark M.; Mustari, Michael J.; McLoon, Linda K.

2015-01-01

Purpose. Unilateral treatment with sustained release IGF-1 to one medial rectus muscle in infant monkeys was performed to test the hypothesis that strabismus would develop as a result of changes in extraocular muscles during the critical period of development of binocularity. Methods. Sustained release IGF-1 pellets were implanted unilaterally on one medial rectus muscle in normal infant monkeys during the first 2 weeks of life. Eye position was monitored using standard photographic methods. After 3 months of treatment, myofiber and neuromuscular size, myosin composition, and innervation density were quantified in all rectus muscles and compared to those in age-matched controls. Results. Sustained unilateral IGF-1 treatments resulted in strabismus for all treated subjects; 3 of the 4 subjects had a clinically significant strabismus of more than 10°. Both the treated medial rectus and the untreated ipsilateral antagonist lateral rectus muscles had significantly larger myofibers. No adaptation in myofiber size occurred in the contralateral functionally yoked lateral rectus or in myosin composition, neuromuscular junction size, or nerve density. Conclusions. Sustained unilateral IGF-1 treatment to extraocular muscles during the sensitive period of development of orthotropic eye alignment and binocularity was sufficient to disturb ocular motor development, resulting in strabismus in infant monkeys. This could be due to altering fusion of gaze during the early sensitive period. Serial measurements of eye alignment suggested the IGF-1-treated infants received insufficient coordinated binocular experience, preventing the establishment of normal eye alignment. Our results uniquely suggest that abnormal signaling by the extraocular muscles may be a cause of strabismus. PMID:26030103

A mouse model of ocular blast injury that induces closed globe anterior and posterior pole damage

PubMed Central

Hines-Beard, Jessica; Marchetta, Jeffrey; Gordon, Sarah; Chaum, Edward; Geisert, Eldon E.; Rex, Tonia S.

2012-01-01

We developed and characterized a mouse model of primary ocular blast injury. The device consists of: a pressurized air tank attached to a regulated paintball gun with a machined barrel; a chamber that protects the mouse from direct injury and recoil, while exposing the eye; and a secure platform that enables fine, controlled movement of the chamber in relation to the barrel. Expected pressures were calculated and the optimal pressure transducer, based on the predicted pressures, was positioned to measure output pressures at the location where the mouse eye would be placed. Mice were exposed to one of three blast pressures (23.6, 26.4, or 30.4psi). Gross pathology, intraocular pressure, optical coherence tomography, and visual acuity were assessed 0, 3, 7, 14, and 28 days after exposure. Contralateral eyes and non-blast exposed mice were used as controls. We detected increased damage with increased pressures and a shift in the damage profile over time. Gross pathology included corneal edema, corneal abrasions, and optic nerve avulsion. Retinal damage was detected by optical coherence tomography and a deficit in visual acuity was detected by optokinetics. Our findings are comparable to those identified in Veterans of the recent wars with closed eye injuries as a result of blast exposure. In summary, this is a relatively simple system that creates injuries with features similar to those seen in patients with ocular blast trauma. This is an important new model for testing the short-term and long-term spectrum of closed globe blast injuries and potential therapeutic interventions. PMID:22504073

[Visual evoked potentials produced by monocular flash stimuli in the cerebral cortex of the rabbit. I. Typography].

PubMed

Pérez-Cobo, J C; Ruiz-Beramendi, M; Pérez-Arroyo, M

1990-12-01

The visually evoked potentials in the hemisphere contralateral to the stimulated eye in rabbit, can be described topographically as follows. While a positive wave (P1) begins forming in the anterior zones and in the V I binocular zone, the N0 wave, at times very large, is produced in a more occipital zone, which corresponds to the visual streak. Immediately afterwards, the positivity, P1, practically invades the whole of the hemisphere. After this, the N1 wave which is produced in the most posterior parts of the V I, begins forming. The whole phenomenon comes to an end when the P2 wave is generated in the most occipital zones.

Clinical Study of 27 Patients with Medial Medullary Infarction.

PubMed

Akimoto, Takayoshi; Ogawa, Katsuhiko; Morita, Akihiko; Suzuki, Yutaka; Kamei, Satoshi

2017-10-01

Medial medullary infarction (MMI) is a rare ischemic stroke. Frequency of each neurological finding in MMI was different in each study. We retrospectively evaluated the medical records of patients with cerebral infarction who were admitted between March 1998 and October 2015. Patients in our study were diagnosed as having MMI by magnetic resonance image examination. Of 2727 patients with ischemic stroke, 27 patients (20 males and 7 females) had MMI. The MMI was complicated by infarcts located in the pons (n = 6), cerebellum (n = 2), and lateral medulla (n = 1). One patient had bilateral MMI. Large-artery atherosclerosis was the most common etiology. Motor weakness of the extremities was the most common neurological finding. Diminished contralateral superficial sensation was more common than diminished contralateral vibratory sensation, and these 2 types of sensory disturbance were often complicated. The patients with large MMI significantly more often accompanied diminished touch (P = .003), pain (P = .017), and vibratory (P = .019) sensation. Facial weakness was shown more common contralateral to the infarcts than ipsilateral (n = 8 contralateral, n = 1 ipsilateral). Lingual palsy was also more common contralateral to the lesions (n = 3 contralateral, n = 1 ipsilateral). One patient alone fulfilled the classical Dejerine triad. In MMI, motor weakness of extremities was commonly shown, and complication of diminished sensations indicated the large infarcts. As for facial weakness and lingual palsy, the supranuclear type was more prominent than the infranuclear type. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Simple shielding reduces dose to the contralateral breast during prone breast cancer radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goyal, Uma, E-mail: uma.goyal@gmail.com; Locke, Angela; Smith-Raymond, Lexie

Our goal was to design a prone breast shield for the contralateral breast and study its efficacy in decreasing scatter radiation to the contralateral breast in a prone breast phantom setup receiving radiation therapy designed for breast cancer. We constructed a prone breast phantom setup consisting of (1) A thermoplastic mask with a left-sided depression created by a water balloon for a breast shape; (2) 2 plastic bags to hold water in the thermoplastic mask depression; (3) 2000 mL of water to fill the thermoplastic mask depression to create a water-based false breast; (4) 1-cm thick bolus placed in themore » contralateral breast holder; (5) 2 lead (Pb) sheets, each 0.1-cm thick for blocking scatter radiation in the contralateral bolus-based false breast; (6) a prone breast board to hold the thermoplastic mask, water, bolus, and lead; (7) 9 cm solid water on top of the breast board to simulate body; (8) a diode was used to verify dose for each treatment field of the treated water-based breast; (9) metal–oxide–semiconductor-field effect transistor (MOSFET) dosimeters to measure dose to the contralateral bolus-based breast. The phantom prone breast setup was CT simulated and treatment was designed with 95% isodose line covering the treated breast. The maximum dose was 107.1%. Megavoltage (MV) port images ensured accurate setup. Measurements were done using diodes on the treated water-based breast and MOSFET dosimeters at the medial and lateral sides of the contralateral bolus-based breast without and with the Pb shield. Five treatments were done for each of the 3 data sets and recorded individually for statistical purposes. All treatments were completed with 6 MV photons at 200 cGy per treatment. The dose contributions from each of the 3 data sets including 15 treatments total without and with the prone lead shield to the medial and lateral portions of contralateral bolus-based breast were averaged individually. Unshielded dose means were 37.11 and 2.94 cGy, and shielded dose means were 12.68 and 1.54 cGy, respectively. When comparing medial and lateral portions of the contralateral bolus-based doses without and with Pb, the shield significantly reduced dose to both sides of the contralateral breast (medial p = 2.64 × 10{sup −14}, lateral p = 4.91 × 10{sup −6}). The prone 0.2-cm Pb shield significantly reduced scatter dose to the contralateral breast on the order of 2 to 3 times. Reductions may be clinically relevant for women younger than 45 years by decreasing the risk of contralateral radiation-induced breast cancer in patients receiving radiation therapy for breast cancer. This shield is simple as it would be a part of the prone breast board during treatments, but future studies are warranted for safety and efficacy clinically.« less

The Impact of Inoculation Parameters on the Pathogenesis of Contact Lens–Related Infectious Keratitis

PubMed Central

Tam, Connie; Mun, James J.; Evans, David J.

2010-01-01

Purpose. Contact lens wear predisposes to Pseudomonas aeruginosa keratitis, but the mechanisms involved remain unclear. An in vivo model was used to study lens inoculation conditions enabling disease. Methods. Custom-made hydrogel contact lenses were fitted to rats after incubation in P. aeruginosa approximately 1011 cfu/mL (3 hours) or approximately 103 cfu/mL (24 hours). Another group was inadvertently inoculated with a suction pen previously used with high inocula, but rinsed in ethanol and stored dry (6 months). Some corneas were tissue paper–blotted to cause fluorescein staining before lens fitting. Contralateral eyes were untreated. Twenty-four hours after disease detection, lenses were transferred to naive rats or examined by confocal microscopy before homogenization to quantify viable bacteria. After lens removal, corneas were washed to collect nonadherent bacteria and were analyzed by immunohistochemistry. Results. All eyes challenged with unworn contaminated lenses developed keratitis after approximately 7 to 10 days. Disease delay and severity were unaffected by inoculum parameters or tissue blotting but occurred sooner with lenses transferred from infected eyes (∼2 days). Worn lenses and corneal washes contained infecting bacteria. Posterior, not anterior, lens surfaces harbored P. aeruginosa biofilms that penetrated the lens matrix. Diseased corneas showed an infiltration of phagocytes and T-lymphocytes. Conclusions. P. aeruginosa induces keratitis in this lens-wearing model after a single inoculation. Delayed disease onset was interesting considering the greater keratitis risk during extended wear. Infection did not require the disruption of corneal barrier function before lens wear and occurred without exposure to lens care solutions. The data suggest that keratitis involves biofilm formation or other bacterial adaptations in vivo. PMID:20130275

Glioprotection of Retinal Astrocytes After Intravitreal Administration of Memantine in the Mouse Optic Nerve Crush Model.

PubMed

Maciulaitiene, Ruta; Pakuliene, Giedre; Kaja, Simon; Pauza, Dainius Haroldas; Kalesnykas, Giedrius; Januleviciene, Ingrida

2017-03-07

BACKGROUND In glaucoma, non-intraocular pressure (IOP)-related risk factors can result in increased levels of extracellular glutamate, which triggers a cascade of neurodegeneration characterized by the excessive activation of N-methyl-D-aspartate (NMDA). The purpose of our study was to evaluate the glioprotective effects of memantine as a prototypic uncompetitive NMDA blocker on retinal astrocytes in the optic nerve crush (ONC) mouse model for glaucoma. MATERIAL AND METHODS Optic nerve crush was performed on all of the right eyes (n=8), whereas left eyes served as contralateral healthy controls (n=8) in Balb/c/Sca mice. Four randomly assigned mice received 2-µl intravitreal injections of memantine (1 mg/ml) after ONC in the experimental eye. One week after the experiment, optic nerves were dissec-ted and stained with methylene blue. Retinae were detached from the sclera. The tissue was immunostained. Whole-mount retinae were investigated by fluorescent microscopy. Astrocyte counts for each image were performed manually. RESULTS Histological sections of crushed optic nerves showed consistently moderate tissue damage in experimental groups. The mean number of astrocytes per image in the ONC group was significantly lower than in the healthy control group (7.13±1.5 and 10.47±1.9, respectively). Loss of astrocytes in the memantine-treated group was significantly lower (8.83±2.2) than in the ONC group. Assessment of inter-observer reliability showed excellent agreement among observations in control, ONC, and memantine groups. CONCLUSIONS The ONC is an effective method for investigation of astrocytic changes in mouse retina. Intravitreally administered memantine shows a promising glioprotective effect on mouse retinal astrocytes by preserving astrocyte count after ONC.

Development of a risk score for geographic atrophy in complications of the age-related macular degeneration prevention trial.

PubMed

Ying, Gui-Shuang; Maguire, Maureen G

2011-02-01

To develop a risk score for developing geographic atrophy (GA) involving easily obtainable information among patients with bilateral large drusen. Cohort study within a multicenter randomized clinical trial. We included 1052 participants with ≥ 10 large (>125 μm) drusen and visual acuity ≥ 20/40 in each eye. In the Complications of Age-related Macular Degeneration (AMD) Prevention Trial (CAPT), 1 eye of each participant was randomly assigned to laser treatment and the contralateral eye was assigned to observation to evaluate whether laser treatment of drusen could prevent vision loss. Gradings by a reading center were used to identify: CAPT end point GA (total area of GA [>250 μm] > 1 disc area), GA (>175 μm) involving the foveal center (CGA), and GA of any size and location (any GA). Established risk factors (age, smoking status, hypertension, Age-related Eye Disease Study simple severity scale score), both with and without a novel risk factor (night vision score), were used in assigning risk points. The risk scores were evaluated for the ability to discriminate and calibrate GA risk. Development of end point GA, CGA, and any GA. Among 942 CAPT participants who completed 5 years of follow-up and did not have any GA at baseline, 6.8% participants developed CAPT end point GA, 9.6% developed CGA, and 34.4% developed any GA. The 5-year incidence of end point GA in 1 or both eyes of a participant increased with the 15-point GA risk score, from 0.6% for <7 points to 15% for ≥ 12 points. The 5-factor risk score predicted development of GA moderately well with the area under the receiver operating characteristic curve (AUC) 0.76 (95% confidence interval [CI], 0.71-0.81) for end point GA; 0.76 (95% CI, 0.71-0.80) for CGA, and 0.68 (95% CI, 0.65-0.72) for any GA. Prediction from the risk score without the night vision score had lower AUCs (range, 0.67-0.72). If validated in other patients, the GA risk score will be useful for identifying high-risk patients for clinical trials of prevention of GA and for clinical assessment of GA risk in early AMD patients. Copyright © 2011 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Younger patients are at increased risk for graft rupture and contralateral injury after anterior cruciate ligament reconstruction.

PubMed

Webster, Kate E; Feller, Julian A; Leigh, Warren B; Richmond, Anneka K

2014-03-01

Graft rupture of the same knee or injury to the anterior cruciate ligament (ACL) in the contralateral knee is a devastating outcome after ACL reconstruction surgery. While a number of factors have been identified as potentially increasing the risk of subsequent ACL injury, the literature is far from definitive. To determine the rates of graft rupture and contralateral ACL injury in a large cohort and to investigate patient characteristics that may be associated with these. Case-control study; Level of evidence, 3. A consecutive cohort of 750 patients who had undergone primary ACL reconstruction surgery with a minimum 3-year follow-up were questioned about the incidence of ACL graft rupture, contralateral ACL injury, family history of ACL injury, and current activity level. Patient databases provided details for age, sex, original injury mechanism, meniscus or articular surface injury, and graft diameter. Responses were received from 561 patients (75%) at a mean ± SD follow-up time of 4.8 ± 1.1 years. Anterior cruciate ligament graft ruptures occurred in 25 patients (4.5%), and contralateral ACL injuries occurred in 42 patients (7.5%). The highest incidence of further ACL injury occurred in patients younger than 20 years at the time of surgery. In this group, 29% sustained a subsequent ACL injury to either knee. The odds for sustaining an ACL graft rupture or contralateral injury increased 6- and 3-fold, respectively, for patients younger than 20 years. Returning to cutting/pivoting sports increased the odds of graft rupture by a factor of 3.9 and contralateral rupture by a factor of 5. A positive family history doubled the odds for both graft rupture and contralateral ACL injury. Patients younger than 20 years who undergo ACL reconstruction are at significantly increased risk for both graft rupture and contralateral ACL injury. Whether age per se is a risk factor or age represents a proxy for other factors remains to be determined.

Coding of Velocity Storage in the Vestibular Nuclei.

PubMed

Yakushin, Sergei B; Raphan, Theodore; Cohen, Bernard

2017-01-01

Semicircular canal afferents sense angular acceleration and output angular velocity with a short time constant of ≈4.5 s. This output is prolonged by a central integrative network, velocity storage that lengthens the time constants of eye velocity. This mechanism utilizes canal, otolith, and visual (optokinetic) information to align the axis of eye velocity toward the spatial vertical when head orientation is off-vertical axis. Previous studies indicated that vestibular-only (VO) and vestibular-pause-saccade (VPS) neurons located in the medial and superior vestibular nucleus could code all aspects of velocity storage. A recently developed technique enabled prolonged recording while animals were rotated and received optokinetic stimulation about a spatial vertical axis while upright, side-down, prone, and supine. Firing rates of 33 VO and 8 VPS neurons were studied in alert cynomolgus monkeys. Majority VO neurons were closely correlated with the horizontal component of velocity storage in head coordinates, regardless of head orientation in space. Approximately, half of all tested neurons (46%) code horizontal component of velocity in head coordinates, while the other half (54%) changed their firing rates as the head was oriented relative to the spatial vertical, coding the horizontal component of eye velocity in spatial coordinates. Some VO neurons only coded the cross-coupled pitch or roll components that move the axis of eye rotation toward the spatial vertical. Sixty-five percent of these VO and VPS neurons were more sensitive to rotation in one direction (predominantly contralateral), providing directional orientation for the subset of VO neurons on either side of the brainstem. This indicates that the three-dimensional velocity storage integrator is composed of directional subsets of neurons that are likely to be the bases for the spatial characteristics of velocity storage. Most VPS neurons ceased firing during drowsiness, but the firing rates of VO neurons were unaffected by states of alertness and declined with the time constant of velocity storage. Thus, the VO neurons are the prime components of the mechanism of coding for velocity storage, whereas the VPS neurons are likely to provide the path from the vestibular to the oculomotor system for the VO neurons.

Coding of Velocity Storage in the Vestibular Nuclei

PubMed Central

Yakushin, Sergei B.; Raphan, Theodore; Cohen, Bernard

2017-01-01

Semicircular canal afferents sense angular acceleration and output angular velocity with a short time constant of ≈4.5 s. This output is prolonged by a central integrative network, velocity storage that lengthens the time constants of eye velocity. This mechanism utilizes canal, otolith, and visual (optokinetic) information to align the axis of eye velocity toward the spatial vertical when head orientation is off-vertical axis. Previous studies indicated that vestibular-only (VO) and vestibular-pause-saccade (VPS) neurons located in the medial and superior vestibular nucleus could code all aspects of velocity storage. A recently developed technique enabled prolonged recording while animals were rotated and received optokinetic stimulation about a spatial vertical axis while upright, side-down, prone, and supine. Firing rates of 33 VO and 8 VPS neurons were studied in alert cynomolgus monkeys. Majority VO neurons were closely correlated with the horizontal component of velocity storage in head coordinates, regardless of head orientation in space. Approximately, half of all tested neurons (46%) code horizontal component of velocity in head coordinates, while the other half (54%) changed their firing rates as the head was oriented relative to the spatial vertical, coding the horizontal component of eye velocity in spatial coordinates. Some VO neurons only coded the cross-coupled pitch or roll components that move the axis of eye rotation toward the spatial vertical. Sixty-five percent of these VO and VPS neurons were more sensitive to rotation in one direction (predominantly contralateral), providing directional orientation for the subset of VO neurons on either side of the brainstem. This indicates that the three-dimensional velocity storage integrator is composed of directional subsets of neurons that are likely to be the bases for the spatial characteristics of velocity storage. Most VPS neurons ceased firing during drowsiness, but the firing rates of VO neurons were unaffected by states of alertness and declined with the time constant of velocity storage. Thus, the VO neurons are the prime components of the mechanism of coding for velocity storage, whereas the VPS neurons are likely to provide the path from the vestibular to the oculomotor system for the VO neurons. PMID:28861030

[Prediction of occult carcinoma in contralateral nodules based on the ultrasonic features of unilateral papillary thyroid carcinoma].

PubMed

Yang, L M; Li, Q; Zhao, B W; Lyu, J G; Xu, H S; Xu, L L; Li, S Y; Gao, L; Zhu, J

2017-04-07

Objective: To investigate the occurrence of occult carcinoma in contralateral lobes based on the ultrasonic features of unilateral papillary thyroid carcinoma. Methods: The study included 202 consecutives cases of unilateral papillary thyroid carcinoma with benign nodules in the contralateral lobe identified by preoperative ultrasound or fine-needle aspiration from June 2014 to December 2015. All patients received total thyroidectomies, and with postoperative pathological examination they were divided into two groups, one including 60 cases with positive occult cancer and another one consisting of 142 cases with negative occult cancer. Univariate and multivariate analyses were performed to analyze the sonographic features of unilateral papillary thyroid carcinoma relevant to the occurrence of occult carcinoma in the contralateral nodules. Results: Univariate analysis indicated occult carcinoma in the contralateral lobes was associated with Hashimoto's thyroiditis(χ(2)=3.955, P =0.047), unclear border (χ(2)=4.375, P =0.036)and multifocality in the ipsilateral(χ(2)=7.375, P =0.007), but not with tumors maximum size, location, A/T, shape, internal structure, internal echo, acoustic halo, calcification, capsular invasion and blood flow signal in the lobe with carcinoma on another side. Multivariate analysis showed unclear border ( OR =2.727, P =0.010) and multifocality in the ipsilateral( OR =2.807, P =0.005)of carcinoma were independent predictive factor for contralateral occult PTC. Conclusions: Unclear border and multifocality of PTC in the ipsilateral were closely relevant to the occurrence of occult carcinoma in the contralateral nodules.

Ipsilateral hemiparesis in ischemic stroke patients.

PubMed

Inatomi, Y; Nakajima, M; Yonehara, T; Ando, Y

2017-07-01

To investigate clinical characteristics of ipsilateral hemiparesis in ischemic stroke patients. Patients with acute ischemic stroke were prospectively examined. Ipsilateral hemiparesis was defined as hemiparesis ipsilateral to recent stroke lesions. Patients with ipsilateral hemiparesis were examined with functional neuroimaging studies including transcranial magnetic stimulation (TMS) and functional MRI. Of 8360 patients, ipsilateral hemiparesis was detected in 14 patients (0.17%, mean age 71±6 years, eight men). Lesions responsible for the recent strokes were located in the frontal cortex in three patients, corona radiata in seven, internal capsule in one, and pons in three. These lesions were located along the typical route of the corticospinal tract in all but one patient. Thirteen patients also had a past history of stroke contralateral to the recent lesions; 12 of these had motor deficits contralateral to past stroke lesions. During TMS, ipsilateral magnetic evoked potentials were evoked in two of seven patients and contralateral potentials were evoked in all seven. Functional MRI activated cerebral hemispheres ipsilaterally in eight of nine patients and contralaterally in all nine. Most patients with ipsilateral hemiparesis had a past history of stroke contralateral to the recent one, resulting in motor deficits contralateral to the earlier lesions. Moreover, functional neuroimaging findings indicated an active crossed corticospinal tract in all of the examined patients. Both findings suggest the contribution of the uncrossed corticospinal tract contralateral to stroke lesions as a post-stroke compensatory motor system. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Risk of Cataract among Subjects with the Acquired Immune Deficiency Syndrome Free of Ocular Opportunistic Infections

PubMed Central

Kempen, John H.; Sugar, Elizabeth A.; Varma, Rohit; Dunn, James P.; Heinemann, Murk-Hein; Jabs, Douglas A.; Lyon, Alice T.; Lewis, Richard A.

2014-01-01

Purpose To evaluate the risk of cataract in the setting of AIDS. Design Prospective cohort study. Participants Subjects with AIDS free of ocular opportunistic infections throughout catamnesis. Methods During 1998–2008 inclusive, subjects ≥13 years of age were enrolled. Demographic characteristics and clinical characteristics were documented at enrollment and semiannually. Main Outcome Measures Cataract was defined as high-grade lens opacity observed by biomicroscopy and judged to be the cause of a best-corrected visual acuity worse than 20/40. Eyes that underwent cataract surgery during follow-up were considered to have developed cataract prior to the first visit when pseudophakia or aphakia was observed. Results Among 1,606 participants (3,212 eyes), at enrollment 1.9% (95% confidence interval (CI): 1.3%−2.7%) were observed to have cataract or prior cataract surgery. Among the 2,812 eyes initially free of cataract, and followed longitudinally (median follow-up=4.6 years), the incidence of cataract was 0.37%/eye-year (95% CI: 0.26%– 0.53%). In addition to age, significant cataract risk factors included prior cataract in the contralateral eye (adjusted hazard ratio (aHR)=21.6, 95% CI: 10.4–44.8), anterior segment inflammation (aHR=4.40, 95% CI: 1.64–11.9), prior retinal detachment (aHR=4.94, 95% CI: 2.21–11.0), and vitreous inflammation (aHR=7.12, 95% CI: 2.02– 25.0), each studied as a time-updated characteristic. Detectable HIV RNA in peripheral blood was associated with lower risk of cataract at enrollment (adjusted odds ratio=0.32, 95% CI: 0.12–0.80) but not of incident cataract (aHR=1.58, 95% CI: 0.90–2.76). After adjustment for other factors, neither the then current absolute CD4+ T cell count nor antiretroviral therapy status showed consistent association with cataract risk, nor did an additive diagnosis of other other co-morbidities. Compared to the available population-based studies that used similar definitions of cataract, the age-specific prevalence of cataract in our cohort was higher than in one of two such studies, and the age-specific incidence of cataract surgery was higher. Conclusions Our results suggest cataract may occur earlier among patients with AIDS free of ocular opportunistic infections than in the general population. Cataract risk was associated most strongly with age and with other ocular morbidity in this population. With improved survival, the burden of cataract likely will increase for persons with HIV/AIDS. PMID:25109932

Subsequent Total Joint Arthroplasty After Primary Total Knee or Hip Arthroplasty

PubMed Central

Sanders, Thomas L.; Maradit Kremers, Hilal; Schleck, Cathy D.; Larson, Dirk R.; Berry, Daniel J.

2017-01-01

Background: Despite the large increase in total hip arthroplasties and total knee arthroplasties, the incidence and prevalence of additional contralateral or ipsilateral joint arthroplasty are poorly understood. The purpose of this study was to determine the rate of additional joint arthroplasty after a primary total hip arthroplasty or total knee arthroplasty. Methods: This historical cohort study identified population-based cohorts of patients who underwent primary total hip arthroplasty (n = 1,933) or total knee arthroplasty (n = 2,139) between 1969 and 2008. Patients underwent passive follow-up through their medical records beginning with the primary total hip arthroplasty or total knee arthroplasty. We assessed the likelihood of undergoing a subsequent total joint arthroplasty, including simultaneous and staged bilateral procedures. Age, sex, and calendar year were evaluated as potential predictors of subsequent arthroplasty. Results: During a mean follow-up of 12 years after an initial total hip arthroplasty, we observed 422 contralateral total hip arthroplasties (29% at 20 years), 76 contralateral total knee arthroplasties (6% at 10 years), and 32 ipsilateral total knee arthroplasties (2% at 20 years). Younger age was a significant predictor of contralateral total hip arthroplasty (p < 0.0001), but not a predictor of the subsequent risk of total knee arthroplasty. During a mean follow-up of 11 years after an initial total knee arthroplasty, we observed 809 contralateral total knee arthroplasties (45% at 20 years), 31 contralateral total hip arthroplasties (3% at 20 years), and 29 ipsilateral total hip arthroplasties (2% at 20 years). Older age was a significant predictor of ipsilateral or contralateral total hip arthroplasty (p < 0.001). Conclusions: Patients undergoing total hip arthroplasty or total knee arthroplasty can be informed of a 30% to 45% chance of a surgical procedure in a contralateral cognate joint and about a 5% chance of a surgical procedure in noncognate joints within 20 years of initial arthroplasty. Increased risk of contralateral total knee arthroplasty following an initial total hip arthroplasty may be due to gait changes prior to and/or following total hip arthroplasty. The higher prevalence of bilateral total hip arthroplasty in younger patients may result from bilateral disease processes that selectively affect the young hip, such as osteonecrosis, or structural hip problems, such as acetabular dysplasia or femoroacetabular impingement. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence. PMID:28244910

The Influence of the Contralateral Knee Prior to Knee Arthroplasty on Post-Arthroplasty Function: The Multicenter Osteoarthritis Study

PubMed Central

Maxwell, Jessica; Niu, Jingbo; Singh, Jasvinder A.; Nevitt, Michael C.; Law, Laura Frey; Felson, David

2013-01-01

Background: Some of the poor functional outcomes of knee arthroplasty may be due to pain in the contralateral, unreplaced knee. We investigated the relationship between the preoperative pain status of the contralateral knee and the risk of a poor postoperative functional outcome in patients who underwent knee arthroplasty. Methods: We analyzed data on 271 patients in the Multicenter Osteoarthritis Study who had undergone knee arthroplasty since the time of enrollment. Eighty-six percent of these patients were white, 72% were female, and the mean age was sixty-seven years. The severity of pain in the knee contralateral to the one that was replaced was measured before the knee arthroplasty with use of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain scale, with the scores being grouped into four categories (0, 1 to 4, 5 to 9, and 10 to 20). Poor post-arthroplasty function six months or more after surgery was determined with use of the Patient Acceptable Symptom State (PASS) outcome tool and a clinical performance measure of walking speed. We evaluated the relationship between contralateral pain severity and the functional outcomes with use of Poisson regression. Results: Seventy-two (27%) of 264 patients demonstrated poor post-arthroplasty function by failing to attain the threshold PASS score, and seventy-six (30%) of 250 subjects had a slow walking speed. As the pre-arthroplasty pain in the contralateral knee increased, there was a steady increase in the proportion with poor post-arthroplasty function (p < 0.0001 for PASS and p = 0.04 for slow walking speed). Compared with patients who had no pre-arthroplasty pain in the contralateral knee, those in the highest category of contralateral pain severity had 4.1 times the risk (95% confidence interval, 1.5 to 11.5) of having poor self-reported post-arthroplasty function. Patients in whom both knees had been replaced at the time of outcome collection were less likely to have poor self-reported function than those in whom only one knee had been replaced. Conclusions: Preoperative pain in the contralateral knee is strongly associated with self-reported post-arthroplasty functional outcome and may therefore be a useful indicator of prognosis or a potential target of perioperative intervention. Level of Evidence: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence. PMID:23780536

Hemispheric differences of motor execution: a near-infrared spectroscopy study.

PubMed

Helmich, Ingo; Rein, Robert; Niermann, Nico; Lausberg, Hedda

2013-01-01

Distal movements of the limbs are predominantly controlled by the contralateral hemisphere. However, functional neuroimaging studies do not unequivocally demonstrate a lateralization of the cerebral activation during hand movements. While some studies show a predominant activation of the contralateral hemisphere, other studies provide evidence for a symmetrically distributed bihemispheric activation. However, the divergent results may also be due to methodological shortcomings. Therefore, the present study using functional near-infrared spectroscopy examines cerebral activation in both hemispheres during motor actions of the right and left hands. Twenty participants performed a flexion/extension task with the right- or left-hand thumb. Cerebral oxygenation changes were recorded from 48 channels over the primary motor, pre-motor, supplementary motor, primary somatosensory cortex, subcentral area, and the supramarginal gyrus of each hemisphere. A consistent increase of cerebral oxygenation was found for oxygenated and for total hemoglobin in the hemisphere contralateral to the moving hand, regardless of the laterality. These findings are in line with previous data from localization [1-3] and brain imaging studies [4-6]. The present data support the proposition that there is no hemispheric specialization for simple distal motor tasks. Both hemispheres are equally activated during movement of the contralateral upper limb.

Contralateral ear occlusion for improving the reliability of otoacoustic emission screening tests.

PubMed

Papsin, Emily; Harrison, Adrienne L; Carraro, Mattia; Harrison, Robert V

2014-01-01

Newborn hearing screening is an established healthcare standard in many countries and testing is feasible using otoacoustic emission (OAE) recording. It is well documented that OAEs can be suppressed by acoustic stimulation of the ear contralateral to the test ear. In clinical otoacoustic emission testing carried out in a sound attenuating booth, ambient noise levels are low such that the efferent system is not activated. However in newborn hearing screening, OAEs are often recorded in hospital or clinic environments, where ambient noise levels can be 60-70 dB SPL. Thus, results in the test ear can be influenced by ambient noise stimulating the opposite ear. Surprisingly, in hearing screening protocols there are no recommendations for avoiding contralateral suppression, that is, protecting the opposite ear from noise by blocking the ear canal. In the present study we have compared transient evoked and distortion product OAEs measured with and without contralateral ear plugging, in environmental settings with ambient noise levels <25 dB SPL, 45 dB SPL, and 55 dB SPL. We found out that without contralateral ear occlusion, ambient noise levels above 55 dB SPL can significantly attenuate OAE signals. We strongly suggest contralateral ear occlusion in OAE based hearing screening in noisy environments.

The Aortic Bifurcation Angle as a Factor in Application of the Outback for Femoropopliteal Lesions in Ipsilateral Versus Contralateral Approaches.

PubMed

Raskin, Daniel; Khaitovich, Boris; Balan, Shmuel; Silverberg, Daniel; Halak, Moshe; Rimon, Uri

2018-01-01

To assess the technical success of the Outback reentry device in contralateral versus ipsilateral approaches for femoropopliteal arterial occlusion. A retrospective review of patients treated for critical limb ischemia (CLI) using the Outback between January 2013 and July 2016 was performed. Age, gender, length and site of the occlusion, approach site, aortic bifurcation angle, and reentry site were recorded. Calcification score was assigned at both aortic bifurcation and reentry site. Technical success was assessed. During the study period, a total of 1300 endovascular procedures were performed on 489 patients for CLI. The Outback was applied on 50 femoropopliteal chronic total occlusions. Thirty-nine contralateral and 11 ipsilateral antegrade femoral were accessed. The device was used successfully in 41 patients (82%). There were nine failures, all in the contralateral approach group. Six due to inability to deliver the device due to acute aortic bifurcation angle and three due to failure to achieve luminal reentry. Procedural success was significantly affected by the aortic bifurcation angle (p = 0.013). The Outback has high technical success rates in treatment of femoropopliteal occlusion, when applied from either an ipsi- or contralateral approach. When applied in contralateral access, acute aortic bifurcation angle predicts procedural failure.

Miniopen Transforaminal Lumbar Interbody Fusion with Unilateral Fixation: A Comparison between Ipsilateral and Contralateral Reherniation

PubMed Central

Liu, Fubing; Jiang, Chun

2016-01-01

The aim of this study was to evaluate the risk factors between ipsilateral and contralateral reherniation and to compare the effectiveness of miniopen transforaminal lumbar interbody fusion (TLIF) with unilateral fixation for each group. From November 2007 to December 2014, clinical and radiographic data of each group (ipsilateral or contralateral reherniation) were collected and compared. Functional assessment (Visual Analog Scale (VAS) score and Japanese Orthopaedic Association (JOA)) and radiographic evaluation (fusion status, disc height, lumbar lordosis (LL), and functional spine unit (FSU) angle) were applied to compare surgical effect for each group preoperatively and at final followup. MacNab questionnaire was applied to further evaluate the satisfactory rate after the discectomy and fusion. No difference except pain-free interval was found between ipsilateral and contralateral groups. There was a significant difference in operative time between two groups. No differences were found in clinical and radiographic data for assessment of surgical effect between two groups. The satisfactory rate was decreasing in both groups with time passing after discectomy. Difference in pain-free interval may be a distinction for ipsilateral and contralateral reherniation. Miniopen TLIF with unilateral pedicle screw fixation can be a recommendable way for single level reherniation regardless of ipsilateral or contralateral reherniation. PMID:27885358

Assessment of rock musician's efferent system functioning using contralateral suppression of otoacoustic emissions.

PubMed

Kumar, Prawin; Grover, Vibhu; Publius A, Sam; Sanju, Himanshu Kumar; Sinha, Sachchidanand

2016-12-01

Contralateral suppression of oto acoustic emission (OAE) is referred as activation of efferent system. Previous literature mentioned about the importance of contralateral suppression of OAEs as a tool to assess efferent system in different groups of population. There is dearth of literature to explore the efferent system function in experienced musicians exposed to rock music using TEOAEs and DPOAEs. Two groups of participant (14 rock musicians and 14 non-musicians) in the age range of 18-25 years were involved in the study. Contralateral suppression of TEOAEs and DPOAEs were measured using ILO (Version 6) in both groups. Descriptive statistics showed higher suppression of TEOAEs and DPOAEs in rock-musicians at most of the frequencies in comparison to non-musicians. For DPOAE measures, Mann Whitney U test results revealed significantly greater DPOAE suppression only at 1 kHz and 3 kHz in rock-musicians compared to non-musicians. For within group comparison, Kruskal Wallis test results revealed there were significant difference observed across most of the frequencies i.e. at 1 kHz, 3 kHz and 6 kHz. For TEOAE measures, Mann Whitney U test results revealed that only at 2 kHz, TEOAE suppression in rock-musician was significantly greater compared to non-musicians. Similarly, Kuskal Wallis test results revealed that within group there were no significant differences observed for most of the frequencies except 2 kHz. Based on the above finding, present study concludes that rock musicians are having better efferent system compared to non-musicians. No suppression effect at few frequencies probably indicates more vulnerability at those frequencies. Contralateral suppression of DPOAE shows more significant finding in comparison to contralateral suppression of TEOAEs in present study.

Effect of Different Esthetic Post-Core Materials on Color of Direct-Composite Restorations: A Preliminary Clinical Study.

PubMed

Ayna, Buket; Yılmaz, Berivan D; Izol, Bozan S; Ayna, Emrah; Tacir, İbrahim Halil

2018-06-15

BACKGROUND The purpose of this study was to determine the influence of 2 different esthetic post materials on the final color of direct-composite restorations by using a digital technique under in vivo conditions. MATERIAL AND METHODS We included 22 pulpless incisor teeth treated with conventionally cemented zirconia (n=11) and polyethylene fiber (n=11) posts in the study. Teeth were restored with a hybrid resin. The color of direct-composite restorations and contralateral control teeth was measured using a digital technique. The Commission Internationale de L'Eclairage, or CIE, L*a*b* and RGB color systems were investigated. Descriptive statistical analysis was performed for the CIE L*a*b* values. Color differences (ΔE) for the average L*, a*, and b* color parameters between every pair of groups were calculated (P>.05). RESULTS Significant differences were not found in the color difference luminosity (lum), R, G, B, and L* a* b* values between the zircon-rich glass fiber post (Z) and contralateral control teeth (Cz) (P>.05) and between the polyethylene fiber post (P) and contralateral control teeth (Cp) (P>.05). However, there was a statistically significant difference between the color a* values of the polyethylene fiber post (P) and contralateral control teeth (Cp) (p<0.05). Color differences (ΔE) between the zircon-rich glass fiber post (Z) and contralateral control teeth, and the polyethylene fiber post (P) and contralateral teeth were not statistically significant (P>.05). CONCLUSIONS Definitive restorations were equally affected by the 2 materials. Both materials can be used reliably in clinical practice. However, further research that focuses on the effect of intraoral conditions is needed.

Adaptive functional change of the contralateral kidney after partial nephrectomy.

PubMed

Choi, Se Young; Yoo, Sangjun; You, Dalsan; Jeong, In Gab; Song, Cheryn; Hong, Bumsik; Hong, Jun Hyuk; Ahn, Hanjong; Kim, Choung-Soo

2017-08-01

Partial nephrectomy aims to maintain renal function by nephron sparing; however, functional changes in the contralateral kidney remain unknown. We evaluate the functional change in the contralateral kidney using a diethylene triamine penta-acetic acid (DTPA) renal scan and determine factors predicting contralateral kidney function after partial nephrectomy. A total of 699 patients underwent partial nephrectomy, with a DTPA scan before and after surgery to assess the separate function of each kidney. Patients were divided into three groups according to initial contralateral glomerular filtration rate (GFR; group 1 : <30 ml·min -1 ·1.73 m -2 , group 2 : 30-45 ml·min -1 ·1.73 m -2 , and group 3 : ≥45 ml·min -1 ·1.73 m -2 ). Multiple-regression analysis was used to identify the factors associated with increased GFR of the contralateral kidney over a 4-yr postoperative period. Patients in group 1 had a higher mean age and hypertension history, worse American Society of Anesthesiologists score, and larger tumor size than in the other two groups. The ipsilateral GFR changes at 4 yr after partial nephrectomy were -18.9, -3.6, and 3.9% in groups 1 , 2 , and 3 , respectively, whereas the contralateral GFR changes were 10.8, 25.7, and 38.8%. Age [β: -0.105, 95% confidence interval (CI): -0.213; -0.011, P < 0.05] and preoperative contralateral GFR (β: -0.256, 95% CI: -0.332; -0.050, P < 0.01) were significant predictive factors for increased GFR of the contralateral kidney after 4 yr. The contralateral kidney compensated for the functional loss of the ipsilateral kidney. The increase of GFR in contralateral kidney is more prominent in younger patients with decreased contralateral renal function. Copyright © 2017 the American Physiological Society.

Brain correlates of the orientation of auditory spatial attention onto speaker location in a "cocktail-party" situation.

PubMed

Lewald, Jörg; Hanenberg, Christina; Getzmann, Stephan

2016-10-01

Successful speech perception in complex auditory scenes with multiple competing speakers requires spatial segregation of auditory streams into perceptually distinct and coherent auditory objects and focusing of attention toward the speaker of interest. Here, we focused on the neural basis of this remarkable capacity of the human auditory system and investigated the spatiotemporal sequence of neural activity within the cortical network engaged in solving the "cocktail-party" problem. Twenty-eight subjects localized a target word in the presence of three competing sound sources. The analysis of the ERPs revealed an anterior contralateral subcomponent of the N2 (N2ac), computed as the difference waveform for targets to the left minus targets to the right. The N2ac peaked at about 500 ms after stimulus onset, and its amplitude was correlated with better localization performance. Cortical source localization for the contrast of left versus right targets at the time of the N2ac revealed a maximum in the region around left superior frontal sulcus and frontal eye field, both of which are known to be involved in processing of auditory spatial information. In addition, a posterior-contralateral late positive subcomponent (LPCpc) occurred at a latency of about 700 ms. Both these subcomponents are potential correlates of allocation of spatial attention to the target under cocktail-party conditions. © 2016 Society for Psychophysiological Research.

Proprioception in patients with posterior cruciate ligament tears: A meta-analysis comparison of reconstructed and contralateral normal knees

PubMed Central

Ko, Seung-Nam

2017-01-01

Posterior cruciate ligament (PCL) reconstruction for patients with PCL insufficiency has been associated with postoperative improvements in proprioceptive function due to mechanoreceptor regeneration. However, it is unclear whether reconstructed PCL or contralateral normal knees have better proprioceptive function outcomes. This meta-analysis was designed to compare the proprioceptive function of reconstructed PCL or contralateral normal knees in patients with PCL insufficiency. All studies that compared proprioceptive function, as assessed with threshold to detect passive movement (TTDPM) or joint position sense (JPS) in PCL reconstructed or contralateral normal knees were included. JPS was calculated by reproducing passive positioning (RPP). Five studies met the inclusion/exclusion criteria for the meta-analysis. The proprioceptive function, defined as TTDPM (95% CI: 0.25 to 0.51°; P<0.00001) and RPP (95% CI: 0.19 to 0.45°; P<0.00001), was significantly different between the reconstructed PCL and contralateral normal knees. The mean difference in angle of error between the reconstructed PCL and contralateral normal knees was 0.06° greater in TTDPM than by RPP. In addition, results from subgroup analyses, based on the starting angles and the moving directions of the knee, that evaluated TTDPM at 15° flexion to 45° extension, TTDPM at 45° flexion to 110° flexion, RPP in flexion, and RPP in extension demonstrated that mean angles of error were significantly greater, by 0.38° (P = 0.0001), 0.36° (P = 0.02), 0.36° (P<0.00001), and 0.23° (P = 0.04), respectively, in reconstructed PCL than in contralateral normal knees. The proprioceptive function of PCL reconstructed knees was decreased, compared with contralateral normal knees, as determined by both TTDPM and RPP. In addition, the amount of loss of proprioception was greater in TTDPM than in RPP, even with minute differences. Results from subgroup analysis, that evaluated the mean angles of error in moving directions through RPP, suggested that the moving direction of flexion has a significantly greater mean for angles of error than the moving direction of extension. Although the level of differences between various parameters were statistically significant, further studies are needed to determine whether the small differences (>1°) of the loss of proprioception are clinically relevant. PMID:28922423

Hemispheric and facial asymmetry: faces of academe.

PubMed

Smith, W M

1998-11-01

Facial asymmetry (facedness) of selected academic faculty members was studied in relation to brain asymmetry and cognitive specialization. Comparisons of facedness were made among humanities faculty (H), faculty members of mathematics and physics (M-P), psychologists (P), and a group of randomly selected individuals (R). Facedness was defined in terms of the relative sizes (in square centimeters) of the two hemifaces. It was predicted that the four groups would show differences in facedness, namely, H, right face bias; M-P, left face bias; P, no bias; and R, no bias. The predictions were confirmed, and the results interpreted in terms of known differences in hemispheric specialization of cognitive functions as they relate to the dominant cognitive activity of each of the different groups. In view of the contralateral control of the two hemifaces (below the eyes) by the two hemispheres of the brain, the two sides of the face undergo differential muscular development, thus creating facial asymmetry. Other factors, such as gender, also may affect facial asymmetry. Suggestions for further research on facedness are discussed.

Health of periodontal tissues and resorption status after orthodontic treatment of impacted maxillary canines.

PubMed

Oz, A Z; Ciger, S

2018-03-01

The aim of the present study was to evaluate the changes of incisor root resorption associated with impacted maxillary canines and health of periodontal tissues around maxillary canines erupted with orthodontic treatment. Twenty patients with a unilateral palatally impacted maxillary canine were included in the study. Cone-beam computed tomography images taken before and after orthodontic treatment were compared with the contralateral canines serving as control teeth. Root resorption was present in 10% of central and 40% of lateral incisors before treatment. After treatment, the incidence of resorption decreased. The thickness of the buccal bone surrounding the impacted canines was similar to that surrounding the contralateral canines, except in the apical area. Periodontal pocket depth and alveolar bone loss were greater for the impacted canine teeth than for the contralateral canines. Incisor root resorption associated with impacted canine teeth showed signs of repair after orthodontic treatment. Slight differences related to periodontal health were found between the previously impacted teeth and contralateral canine teeth.

Automated IMRT planning in Pinnacle : A study in head-and-neck cancer.

PubMed

Kusters, J M A M; Bzdusek, K; Kumar, P; van Kollenburg, P G M; Kunze-Busch, M C; Wendling, M; Dijkema, T; Kaanders, J H A M

2017-12-01

This study evaluates the performance and planning efficacy of the Auto-Planning (AP) module in the clinical version of Pinnacle 9.10 (Philips Radiation Oncology Systems, Fitchburg, WI, USA). Twenty automated intensity-modulated radiotherapy (IMRT) plans were compared with the original manually planned clinical IMRT plans from patients with oropharyngeal cancer. Auto-Planning with IMRT offers similar coverage of the planning target volume as the original manually planned clinical plans, as well as better sparing of the contralateral parotid gland, contralateral submandibular gland, larynx, mandible, and brainstem. The mean dose of the contralateral parotid gland and contralateral submandibular gland could be reduced by 2.5 Gy and 1.7 Gy on average. The number of monitor units was reduced with an average of 143.9 (18%). Hands-on planning time was reduced from 1.5-3 h to less than 1 h. The Auto-Planning module was able to produce clinically acceptable head and neck IMRT plans with consistent quality.

Contralateral radiculopathy after transforaminal lumbar interbody fusion in the treatment of lumbar degenerative diseases: A Case Series.

PubMed

Hu, Hong-Tao; Ren, Liang; Sun, Xian-Ze; Liu, Feng-Yu; Yu, Jin-He; Gu, Zhen-Fang

2018-04-01

Transforaminal lumbar interbody fusion (TLIF) is an effective treatment for patients with degenerative lumbar disc disorder. Contralateral radiculopathy, as a complication of TLIF, has been recognized in this institution, but is rarely reported in the literature. In this article, we report 2 cases of contralateral radiculopathy after TLIF in our institution and its associated complications. In the 2 cases, the postoperative computed tomography (CT) and magnetic resonance image (MRI) showed obvious upward movement of the superior articular process, leading to contralateral foraminal stenosis. Revision surgery was done at once to partially resect the opposite superior facet and to relieve nerve root compression. After revision surgery, the contralateral radiculopathy disappeared. Contralateral radiculopathy is an avoidable potential complication. It is very important to create careful preoperative plans and to conscientiously plan the use of intraoperative techniques. In case of postoperative contralateral leg pain, the patients should be examined by CT and MRI. If CT and MRI show that the superior articular process significantly migrated upwards, which leads to contralateral foraminal stenosis, revision surgery should be done at once to partially resect the contralateral superior facet so as to relieve nerve root compression and avoid possible long-term impairment.

The Hyperactivity of Efferent Auditory System in Patients with Schizophrenia: A Transient Evoked Otoacoustic Emissions Study

PubMed Central

Wahab, Suzaily; Abdul Rahman, Abdul Hamid; Sidek, Dinsuhaimi; Zakaria, Mohd. Normani

2016-01-01

Objective Electrophysiological studies, which are mostly focused on afferent pathway, have proven that auditory processing deficits exist in patients with schizophrenia. Nevertheless, reports on the suppressive effect of efferent auditory pathway on cochlear outer hair cells among schizophrenia patients are limited. The present, case-control, study examined the contralateral suppression of transient evoked otoacoustic emissions (TEOAEs) in patients with schizophrenia. Methods Participants were twenty-three healthy controls and sixteen schizophrenia patients with normal hearing, middle ear and cochlear outer hair cells function. Absolute non-linear and linear TEOAEs were measured in both ears by delivering clicks stimuli at 80 dB SPL and 60 dB SPL respectively. Subsequently, contralateral suppression was determined by subtracting the absolute TEOAEs response obtained at 60 dBpe SPL during the absence and presence of contralateral white noise delivered at 65 dB HL. No attention tasks were conducted during measurements. Results We found no significant difference in absolute TEOAEs responses at 80 dB SPL, in either diagnosis or ear groups (p>0.05). However, the overall contralateral suppression was significantly larger in schizophrenia patients (p<0.05). Specifically, patients with schizophrenia demonstrated significantly increased right ear contralateral suppression compared to healthy control (p<0.05). Conclusion The present findings suggest increased inhibitory effect of efferent auditory pathway especially on the right cochlear outer hair cells. Further studies to investigate increased suppressive effects are crucial to expand the current understanding of auditory hallucination mechanisms in schizophrenia patients. PMID:26766950

Severe ipsilateral carotid stenosis and middle cerebral artery disease in lacunar ischaemic stroke: innocent bystanders?

PubMed

Mead, G E; Lewis, S C; Wardlaw, J M; Dennis, M S; Warlow, C P

2002-03-01

Lacunar infarcts are thought to be mostly due to intracranial small vessel disease. Therefore, when a stroke patient with a relevant lacunar infarct does have severe ipsilateral internal carotid artery (ICA) or middle cerebral artery (MCA) disease, it is unclear whether the arterial disease is causative or coincidental. If causative, we would expect ICA/MCA disease to be more severe on the symptomatic side than on the asymptomatic side. Therefore, our aim was to compare the severity of ipsilateral with contralateral ICA and MCA disease in patients with lacunar ischaemic stroke. We studied 259 inpatients and outpatients with a recent lacunar ischaemic stroke and no other prior stroke. We used carotid Duplex ultrasound and transcranial Doppler (TCD) ultrasound to identify ICA and MCA disease, and compared our results with previously published data. In our study, there was no difference between the severity of ipsilateral and contralateral ICA stenosis within individuals (median difference 0%, Wilcoxon paired data p=0.24, comparing severity of ipsilateral and contralateral stenosis). The overall prevalence of severe ipsilateral stenosis was 5%, and the prevalence of severe contralateral stenosis was 4% (OR 1.6, 95% CI 0.6, 4.8). There was no difference in the prevalence of ipsilateral and contralateral MCA disease. A systematic review of the other available studies strengthened this conclusion. Carotid stenosis in patients with a lacunar ischaemic stroke may be coincidental. Further studies are required to elucidate the causes of lacunar stroke, and to evaluate the role of carotid endarterectomy.

Outcome after treatment of ametropia with implantable contact lenses.

PubMed

Lackner, Birgit; Pieh, Stefan; Schmidinger, Gerald; Hanselmayer, Georg; Dejaco-Ruhswurm, Irene; Funovics, Martin A; Skorpik, Christian

2003-11-01

To evaluate long-term results after insertion of implantable contact lenses (ICLs) in phakic eyes. Prospective, noncomparative, interventional case series. Seventy-five phakic eyes (65 myopic, 10 hyperopic eyes) of 45 patients aged 21.7 to 60.6 years were included. STAAR Collamer Implantable Contact Lenses (STAAR Surgical Inc., Nidau, Switzerland) were implanted for correction of high myopia and hyperopia. Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), and intraocular pressure (IOP) were determined. Presence of lens opacification and the distance between the ICL and the crystalline lens were assessed by slit-lamp examination before surgery and at 1, 3, 6 months, and yearly after lens implantation. Preoperative mean spherical equivalent was -16.23+/-5.29 diopters (D) for myopic eyes and +7.88 +/-1.46 D for hyperopic eyes. After ICL implantation, mean residual refractive error was -1.77+/-2.17 D in myopic patients and +0.44+/-0.69 D in hyperopic patients. Preoperative mean UCVA was Snellen 0.03+/-0.03 for myopic patients and Snellen 0.12+/-0.16 for hyperopic patients. Preoperative mean BCVA was Snellen 0.49+/-0.23 for myopic patients and Snellen 0.82+/-0.23 for hyperopic patients. After ICL implantation, mean UCVA up to the end of individual observation time was Snellen 0.36+/-0.36 for myopic patients and Snellen 0.58+/-0.28 for hyperopic patients. Mean BCVA was Snellen 0.73+/-0.26 for myopic and Snellen 0.80+/-0.24 for hyperopic patients. Mean preoperative IOP was 14.2+/-2.7 mmHg, and mean postoperative IOP was 13.46+/-2.1 mmHg over all follow-up investigations. The main complication was the development of subcapsular anterior opacifications of the crystalline lens in 25 eyes (33.3%), 2 of which showed direct contact to the ICL. Eleven eyes (14.7%) were stable in opacification and 14 eyes (18.7%) had progressive opacifications. The median time to opacification was 27.1 months. In 8 patients (10.7%), the subjective visual impairment mandated cataract surgery. The most significant long-term complication after ICL implantation is the formation of opacifications of the crystalline lens with the risk of the necessity of subsequent cataract surgery (10.7%). Old age, female gender, and contralateral opacification are independent significant risk factors for early formation of opacifications in this patient group.

Effect of task set-modulating attentional capture depends on the distractor cost in visual search: evidence from N2pc.

PubMed

Zhao, Dandan; Liang, Shengnan; Jin, Zhenlan; Li, Ling

2014-07-09

Previous studies have confirmed that attention can be modulated by the current task set while involuntarily captured by salient items. However, little is known on which factors the modulation of attentional capture is dependent on when the same stimuli with different task sets are presented. In the present study, participants conducted two visual search tasks with the same search arrays by varying target and distractor settings (color singleton as target, onset singleton as distractor, named as color task, and vice versa). Ipsilateral and contralateral color distractors resulted in two different relative saliences in two tasks, respectively. Both reaction times (RTs) and N2-posterior-contralateral (N2pc) results showed that there was no difference between ipsilateral and contralateral color distractors in the onset task. However, both RTs and the latency of N2pc showed a delay to the ipsilateral onset distractor compared with the contralateral onset distractor. Moreover, the N2pc observed under the contralateral distractor condition in the color task was reversed, and its amplitude was attenuated. On the basis of these results, we proposed a parameter called distractor cost (DC), computed by subtracting RTs under the contralateral distractor condition from the ipsilateral condition. The results suggest that an enhanced DC might be related to the modification of N2pc in searching for the color target. Taken together, these findings provide evidence that the effect of task set-modulating attentional capture in visual search is related to the DC.

Overnight corneal swelling with high and low powered silicone hydrogel lenses.

PubMed

Moezzi, Amir M; Fonn, Desmond; Varikooty, Jalaiah; Simpson, Trefford L

2015-01-01

To compare central corneal swelling after eight hours of sleep in eyes wearing four different silicone hydrogel lenses with three different powers. Twenty-nine neophyte subjects wore lotrafilcon A (Dk, 140), balafilcon A (Dk, 91), galyfilcon A (Dk, 60) and senofilcon A (Dk, 103) lenses in powers -3.00, -10.00 and +6.00 D on separate nights, in random order, and on one eye only. The contra-lateral eye (no lens) served as the control. Central corneal thickness was measured using a digital optical pachometer before lens insertion and immediately after lens removal on waking. For the +6.00 D and -10.00 D, lotrafilcon A induced the least swelling and galyfilcon A the most. The +6.00 D power, averaged across lens materials, induced significantly greater central swelling than the -10.00 and -3.00 D (Re-ANOVA, p<0.001), (7.7±2.9% vs. 6.8±2.8% and 6.5±2.5% respectively) but there was no difference between -10.00 and -3.00 D. Averaged for power, lotrafilcon A induced the least (6.2±2.8%) and galyfilcon A the most (7.6±3.0%) swelling at the center (Re-ANOVA, p<0.001). Central corneal swelling with +6.00 D was significantly greater than -10.00 D lens power despite similar levels of average lens transmissibility of these two lens powers. The differences in corneal swelling of the lens wearing eyes are consistent with the differences in oxygen transmission of the silicone hydrogel lenses. In silicone hydrogel lenses central corneal swelling is mainly driven by central lens oxygen transmissibility. Copyright © 2013 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

Optic neuritis and rapidly progressive necrotizing retinitis as the initial signs of subacute sclerosing panencephalitis: a case report with clinical and histopathologic findings.

PubMed

Oray, Merih; Tuncer, Samuray; Kir, Nur; Karacorlu, Murat; Tugal-Tutkun, Ilknur

2014-08-01

We report a case of subacute sclerosing panencephalitis (SSPE) presenting first with optic neuritis and rapidly progressive necrotizing retinitis at the posterior pole. We reviewed the clinical, laboratory, photographic, angiographic, and histopathologic records of a patient with SSPE. A 15-year-old girl was referred after rapid loss of vision due to optic neuritis and macular necrosis in the right eye. She had a history of cardiac valve surgery, but had no systemic symptoms and extensive work-up was unrewarding. Contralateral involvement with rapidly progressive optic neuritis and macular necrotizing retinitis prompted retinochoroidal biopsy of the right eye, which revealed necrosis of inner retinal layers and perivascular lymphoplasmocytic infiltration with intact choroid and outer retina without any findings of inclusion bodies, microorganisms, or atypical cells. The diagnosis was based on histopathologic findings consistent with SSPE, and detection of elevated measles antibody titers in cerebrospinal fluid and serum. It was further confirmed by development of typical electroencephalography pattern at 6 months and neurological symptoms at 4-year follow-up. Clinicians need to be aware that optic neuritis and necrotizing retinitis at the posterior pole may be the presenting features of SSPE.

Limbal Stem Cell Deficiency and Treatment with Stem Cell Transplantation.

PubMed

Barut Selver, Özlem; Yağcı, Ayşe; Eğrilmez, Sait; Gürdal, Mehmet; Palamar, Melis; Çavuşoğlu, Türker; Ateş, Utku; Veral, Ali; Güven, Çağrı; Wolosin, Jose Mario

2017-10-01

The cornea is the outermost tissue of the eye and it must be transparent for the maintenance of good visual function. The superficial epithelium of the cornea, which is renewed continuously by corneal stem cells, plays a critical role in the permanence of this transparency. These stem cells are localized at the cornea-conjunctival transition zone, referred to as the limbus. When this zone is affected/destroyed, limbal stem cell deficiency ensues. Loss of limbal stem cell function allows colonization of the corneal surface by conjunctival epithelium. Over 6 million people worldwide are affected by corneal blindness, and limbal stem cell deficiency is one of the main causes. Fortunately, it is becoming possible to recover vision by autologous transplantation of limbal cells obtained from the contralateral eye in unilateral cases. Due to the potential risks to the donor eye, only a small amount of tissue can be obtained, in which only 1-2% of the limbal epithelial cells are actually limbal stem cells. Vigorous attempts are being made to expand limbal stem cells in culture to preserve or even enrich the stem cell population. Ex vivo expanded limbal stem cell treatment in limbal stem cell deficiency was first reported in 1997. In the 20 years since, various protocols have been developed for the cultivation of limbal epithelial cells. It is still not clear which method promotes effective stem cell viability and this remains a subject of ongoing research. The most preferred technique for limbal cell culture is the explant culture model. In this approach, a small donor eye limbal biopsy is placed as an explant onto a biocompatible substrate (preferably human amniotic membrane) for expansion. The outgrowth (cultivated limbal epithelial cells) is then surgically transferred to the recipient eye. Due to changing regulations concerning cell-based therapy, the implementation of cultivated limbal epithelial transplantation in accordance with Good Laboratory Practice using xenobiotic-free systems is becoming widely accepted both in Turkey and worldwide.

Effect of excessive contralateral trunk tilt on pitching biomechanics and performance in high school baseball pitchers.

PubMed

Oyama, Sakiko; Yu, Bing; Blackburn, J Troy; Padua, Darin A; Li, Li; Myers, Joseph B

2013-10-01

There is a growing number of pitching-related upper extremity injuries among young baseball pitchers; however, there is a lack of data on the identification of injury prevention strategies, particularly the prevention of injuries through the instruction/modification of technique. The identification of technical parameters that are associated with increased joint loading is needed. To investigate the effects of excessive contralateral trunk tilt, a common technique identifiable by video observation, on pitching biomechanics and performance in high school baseball pitchers. The hypothesis was that this strategy is associated with greater joint loading and poor pitching performance. Descriptive laboratory study; Level of evidence, 3. The 3-dimensional pitching biomechanics, ball speed, and frontal view of the pitching technique from 72 high school baseball pitchers were captured on video and analyzed. The videos were reviewed to determine if the pitcher's trunk was excessively contralaterally tilted at the instant of maximal shoulder external rotation by examining whether the side of the pitcher's head ipsilateral to the throwing limb deviated by more than a head width from a vertical line passing through the pitcher's stride foot ankle. Upper extremity kinetics and upper extremity/trunk kinematics between pitchers with and without excessive contralateral trunk tilt were compared using independent t tests. Compared with pitchers who did not demonstrate excessive contralateral trunk tilt, those with excessive contralateral trunk tilt pitched at a higher ball speed (mean, 32.6 ± 2.2 vs 31.1 ± 2.9 m/s, respectively; P = .019) and experienced a greater elbow proximal force (mean, 103.9 ± 12.7 vs 93.2 ± 13.9 %weight, respectively; P = .001), shoulder proximal force (mean, 104.8 ± 14.1 vs 94.3 ± 15.5 %weight, respectively; P = .004), elbow varus moment (mean, 4.29 ± 0.73 vs 3.84 ± 0.8 %height*weight, respectively; P = .017), and shoulder internal rotation moment (mean, 4.21 ± 0.71 vs 3.75 ± 0.78 %height*weight, respectively; P = .011). Pitchers with excessive contralateral trunk tilt demonstrated less upper torso flexion at stride foot contact, less upper torso rotation, and greater upper torso contralateral flexion at maximal shoulder external rotation and ball release (P < .05). Excessive contralateral trunk tilt is a strategy that is associated with higher ball speeds and increased joint loading. Pitching with excessive contralateral trunk tilt, which can be identified through screening of the pitching technique, is associated with a benefit in performance and increased joint loading. Future study is warranted to determine if this strategy should be encouraged or discouraged by baseball coaches.

Noonan's syndrome with keratoconus and optic disc coloboma.

PubMed

Ascaso, F J; Del Buey, M A; Huerva, V; Latre, B; Palomar, A

1993-01-01

We report the case of a 14-year-old girl with multiple findings characteristic of Noonan's syndrome, including short stature, mild mental retardation, facial, skeletal and renal abnormalities. In addition, ophthalmic examination revealed a keratoconus in the left eye and a right optic disc coloboma. To date, only two cases of Noonan's syndrome with keratoconus have been reported, and this is the second case of this syndrome with optic disc coloboma. To our knowledge, this is the first report of Noonan's syndrome associated with unilateral keratoconus and contralateral optic disc coloboma. In view of the large number of patients with Noonan's syndrome reported to date and the rarity of these ocular abnormalities, it is most likely that this association is fortuitous. Ocular findings reported in patients with Noonan's syndrome are reviewed.

The nucleus of the optic tract (NOT) and the dorsal terminal nucleus (DTN) of opossums (Didelphis marsupialis aurita).

PubMed

Vargas, C D; Volchan, E; Nasi, J P; Bernardes, R F; Rocha-Miranda, C E

1996-01-01

Wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP) was injected unilaterally into the pretectocollicular region of opossums (Didelphis marsupialis aurita), primarily to investigate the existence of a commissural subcortical pathway but also to reveal afferents and efferents of the nucleus of the optic tract (NOT) and dorsal terminal nucleus (DTN) in this species. Labelled cells and terminals were observed in the contralateral NOT-DTN. Furthermore, HRP was injected bilaterally in the region of the inferior olive (IO) to verify if the distribution of labelled cells in the NOT-DTN overlapped the region of commissural labelled cells. The two subpopulations of retrogradely labelled cells coincided, being distributed within the retinal terminal field attributed to the NOT-DTN, as revealed by contralateral eye injections of HRP. The commissural cells were located slightly more ventral than the olivary cells in the optic tract. The pretectocollicular WGA-HRP injections also labelled cells and terminals bilaterally in the lateral terminal nucleus (LTN), interstitial nucleus of the superior fasciculus, posterior fibers (INSFp), ventral lateral geniculate nucleus (vLGN), and superior colliculus (SC) and ipsilaterally in the medial terminal nucleus (MTN). In addition, further caudally, labelled cells and terminals were observed bilaterally in the nuclei prepositus hypoglossi (PH) and in the medial (MVN) and lateral (LVN) vestibular nuclei. Labelled terminals were found in the ipsilateral nucleus reticularis tegmenti pontis (NRTP) and in the IO with ipsilateral predominance. This study allowed an anatomical delimitation of the NOT-DTN in this opossum species, as defined by the olivary and commissural subpopulations, as well as a hodological evaluation of this region. The existence of some common anatomical aspects with other mammalian species is discussed.

Contralaterally Controlled Functional Electrical Stimulation for Stroke Rehabilitation

PubMed Central

Knutson, Jayme S.; Harley, Mary Y.; Hisel, Terri Z.; Makowski, Nathaniel S.; Fu, Michael J.; Chae, John

2012-01-01

Contralaterally controlled functional electrical stimulation (CCFES) is an innovative method of delivering neuromuscular electrical stimulation for rehabilitation of paretic limbs after stroke. It is being studied to evaluate its efficacy in improving recovery of arm and hand function and ankle dorsiflexion in chronic and subacute stroke patients. The initial studies provide preliminary evidence supporting the efficacy of CCFES. PMID:23365893

Reducing contralateral SI activity reveals hindlimb receptive fields in the SI forelimb-stump representation of neonatally amputated rats.

PubMed

Pluto, Charles P; Chiaia, Nicolas L; Rhoades, Robert W; Lane, Richard D

2005-09-01

In adult rats that sustained forelimb amputation on the day of birth, >30% of multiunit recording sites in the forelimb-stump representation of primary somatosensory cortex (SI) also respond to cutaneous hindlimb stimulation when cortical GABA(A+B) receptors are blocked (GRB). This study examined whether hindlimb receptive fields could also be revealed in forelimb-stump sites by reducing one known source of excitatory input to SI GABAergic neurons, the contralateral SI cortex. Corpus callosum projection neurons connect homotopic SI regions, making excitatory contacts onto pyramidal cells and interneurons. Thus in addition to providing monosynaptic excitation in SI, callosal fibers can produce disynaptic inhibition through excitatory synapses with inhibitory interneurons. Based on the latter of these connections, we hypothesized that inactivating the contralateral (intact) SI forelimb region would "unmask" normally suppressed hindlimb responses by reducing the activity of SI GABAergic neurons. The SI forelimb-stump representation was first mapped under normal conditions and then during GRB to identify stump/hindlimb responsive sites. After GRB had dissipated, the contralateral (intact) SI forelimb region was mapped and reversibly inactivated with injections of 4% lidocaine, and selected forelimb-stump sites were retested. Contralateral SI inactivation revealed hindlimb responses in approximately 60% of sites that were stump/hindlimb responsive during GRB. These findings indicate that activity in the contralateral SI contributes to the suppression of reorganized hindlimb receptive fields in neonatally amputated rats.

Influence of contralateral acoustic hearing on adult bimodal outcomes after cochlear implantation.

PubMed

Plant, Kerrie; van Hoesel, Richard; McDermott, Hugh; Dawson, Pamela; Cowan, Robert

2016-08-01

To examine post-implantation benefit and time taken to acclimate to the cochlear implant for adult candidates with more hearing in the contralateral non-implanted ear than has been previously considered within local candidacy guidelines. Prospective, within-subject experimental design. Forty postlingual hearing-impaired adult subjects with a contralateral ear word score in quiet ranging from 27% to 100% (median 67%). Post-implantation improvement of 2.4 dB and 4.0 dB was observed on a sentence in coincident babble test at presentation levels of 65 and 55 dB SPL respectively, and a 2.1 dB benefit in spatial release from masking (SRM) advantage observed when the noise location favoured the implanted side. Significant post-operative group mean change of between 2.1 and 3.0 was observed on the sub-scales of the speech, spatial, and qualities (SSQ) questionnaire. Degree of post-implantation speech reception threshold (SRT) benefit on the coincident babble test and on perception of soft speech and sounds in the environment was greater for subjects with less contralateral hearing. The degree of contralateral acoustic hearing did not affect time taken to acclimate to the device. The findings from this study support cochlear implantation for candidates with substantial acoustic hearing in the contralateral ear, and provide guidance regarding post-implantation expectations.

Imaging dose in breast radiotherapy: does breast size affect the dose to the organs at risk and the risk of secondary cancer to the contralateral breast?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Batumalai, Vikneswary, E-mail: vikneswary.batumalai@sswahs.nsw.gov.au; South Western Clinical School, University of New South Wales, Sydney, New South Wales; Quinn, Alexandra

Correct target positioning is crucial for accurate dose delivery in breast radiotherapy resulting in utilisation of daily imaging. However, the radiation dose from daily imaging is associated with increased probability of secondary induced cancer. The aim of this study was to quantify doses associated with three imaging modalities and investigate the correlation of dose and varying breast size in breast radiotherapy. Planning computed tomography (CT) data sets of 30 breast cancer patients were utilised to simulate the dose received by various organs from a megavoltage computed tomography (MV-CT), megavoltage electronic portal image (MV-EPI) and megavoltage cone-beam computed tomography (MV-CBCT). Themore » mean dose to organs adjacent to the target volume (contralateral breast, lungs, spinal cord and heart) were analysed. Pearson correlation analysis was performed to determine the relationship between imaging dose and primary breast volume and the lifetime attributable risk (LAR) of induced secondary cancer was calculated for the contralateral breast. The highest contralateral breast mean dose was from the MV-CBCT (1.79 Gy), followed by MV-EPI (0.22 Gy) and MV-CT (0.11 Gy). A similar trend was found for all organs at risk (OAR) analysed. The primary breast volume inversely correlated with the contralateral breast dose for all three imaging modalities. As the primary breast volume increases, the likelihood of a patient developing a radiation-induced secondary cancer to the contralateral breast decreases. MV-CBCT showed a stronger relationship between breast size and LAR of developing a radiation-induced contralateral breast cancer in comparison with the MV-CT and MV-EPI. For breast patients, imaging dose to OAR depends on imaging modality and treated breast size. When considering the use of imaging during breast radiotherapy, the patient's breast size and contralateral breast dose should be taken into account.« less

The critical role of the external carotid artery in cerebral perfusion of patients with total occlusion of the internal carotid artery.

PubMed

Dalainas, I; Avgerinos, E D; Daskalopoulos, M E; Papapetrou, A; Papasideris, C P; Katsikas, V; Xiromeritis, K; Moulakakis, K; Gianakopoulos, T; Liapis, C D

2012-02-01

The ipsilateral external carotid artery (ECA) can potentially provide an important collateral pathway for cerebral blood flow in the presence of occlusion or severe stenosis of the internal carotid artery (ICA), recovering up to 15% of the middle cerebral arterial flow. The aim of the study is to elucidate the role of ECA in cerebral flow of patients with total ICA occlusion. Retrospective study of prospectively collected data of 139 patients with total ICA occlusions. The patients were divided to symptomatic and asymptomatic and were categorized in four subgroups according to the stenosis rates: A) ipsilateral ECA<70% and contralateral internal carotid artery stenosis <70%; B) ipsilateral ECA stenosis <70% and contralateral internal carotid artery stenosis ≥70%; C) ipsilateral ECA stenosis ≥70% and contralateral ICA stenosis <70%; D) ipsilateral ECA stenosis ≥70% and contralateral ICA stenosis ≥75%. Fifty eight (41.7%) patients were asymptomatic. The highest rate (48.2%) of asymptomatic patients was in Group A. Among patients with strokes, the highest rate belonged in groups C and D (44.4% and 50% respectively) where ipsilateral ECA stenosis was ≥70% irrespectively of the contralateral ICA patency. Ipsilateral external carotid artery stenosis ≥70% proved to be and independent risk factor for symptom presentation (P=0.013). The study reveals the significant role of ECA patency in cerebral flow in patients with ICA occlusion.

Experimental murine myopia induces collagen type Iα1 (COL1A1) DNA methylation and altered COL1A1 messenger RNA expression in sclera

PubMed Central

Zhou, Xiangtian; Ji, Fengtao; An, Jianhong; Zhao, Fuxin; Shi, Fanjun; Huang, Furong; Li, Yuan; Jiao, Shiming; Yan, Dongsheng; Chen, Xiaoyan; Chen, JiangFan

2012-01-01

Purpose To investigate whether myopia development is associated with changes of scleral DNA methylation in cytosine-phosphate-guanine (CpG) sites in the collagen 1A1 (COL1A1) promoter and messenger RNA (mRNA) levels following murine form deprivation myopia. Methods Fifty-seven C57BL/6 mice (postnatal day 23) were randomly assigned to four groups: (1) monocular form deprivation (MD) in which a diffuser lens was placed over one eye for 28 days; (2) normal controls without MD; (3) MD recovery in which the diffuser lens was removed for seven days; and (4) MD recovery normal controls. The DNA methylation pattern in COL1A1 promoter and exon 1 was determined by bisulfite DNA sequencing, and the COL1A1 mRNA level in sclera was determined by quantitative PCR. Results MD was found to induce myopia in the treated eyes. Six CpG sites in the promoter and exon 1 region of COL1A1 were methylated with significantly higher frequency in the treated eyes than normal control eyes (p<0.05), with CpG island methylation in MD-contralateral eyes being intermediate. Consistent with the CpG methylation, scleral COL1A1 mRNA was reduced by 57% in the MD-treated eyes compared to normal controls (p<0.05). After seven days of MD recovery, CpG methylation was significantly reduced (p=0.01). The methylation patterns returned to near normal level in five CpG sites, but the sixth was hypomethylated compared to normal controls. Conclusions In parallel with the development of myopia and the reduced COL1A1 mRNA, the frequency of methylation in CpG sites of the COL1A1 promoter/exon 1 increased during MD and returned to near normal during recovery. Thus, hypermethylation of CpG sites in the promoter/exon 1 of COL1A1 may underlie reduced collagen synthesis at the transcriptional level in myopic scleras. PMID:22690110

Postoperative recovery of hippocampal contralateral diffusivity in medial temporal lobe epilepsy.

PubMed

Thivard, Lionel; Tanguy, Marie-Laure; Adam, Claude; Clémenceau, Stéphane; Dezamis, Edouard; Lehéricy, Stéphane; Dormont, Didier; Chiras, Jacques; Baulac, Michel; Dupont, Sophie

2007-03-01

To search for a recovery after surgery of mean diffusivity (MD) values in the contralateral nonsclerotic hippocampus of patients with medial temporal lobe epilepsy (MTLE) and hippocampal sclerosis (HS). Twenty-four MTLE patients (12 right-sided and 12 left-sided MTLE) and 36 healthy volunteers were investigated using diffusion tensor imaging. A region-of-interest approach was used to measure pre- and postoperative interictal hippocampal MD values in patients. Diffusion abnormalities in contralateral nonsclerotic hippocampus recovered after surgery (p<0.0001). A subgroup of 14 patients exhibited a clear increase in MD values whereas the remaining 10 patients were stable. No significant difference was found between the two subgroups for each of the electroclinical data studied including early postoperative outcome, all patients being either seizure free or with rare persistent auras. This finding suggests that diffusion abnormalities in contralateral hippocampus may represent a functional mechanism linked to the active epileptic process.

Does the Dumbbell-Carrying Position Change the Muscle Activity in Split Squats and Walking Lunges?

PubMed

Stastny, Petr; Lehnert, Michal; Zaatar, Amr M Z; Svoboda, Zdenek; Xaverova, Zuzana

2015-11-01

The forward walking lunge (WL) and split squat (SSq) are similar exercises that have differences in the eccentric phase, and both can be performed in the ipsilateral or contralateral carrying conditions. This study aimed to determine the effects of dumbbell-carrying position on the kinematics and electromyographic (EMG) amplitudes of the gluteus medius (Gmed), vastus medialis (VM), vastus lateralis (VL), and biceps femoris during WLs and SSqs. The resistance-trained (RT) and the non-resistance-trained (NT) groups (both n = 14) performed ipsilateral WLs, contralateral WLs, ipsilateral SSqs, and contralateral SSqs in a randomized order in a simulated training session. The EMG amplitude, expressed as a percentage of the maximal voluntary isometric contraction (%MVIC), and the kinematics, expressed as the range of motion (ROM) of the hip and knee, were measured during 5 repetition maximum for both legs. The repeated measure analyses of variance showed significant differences between the RT and NT groups. The NT group showed a smaller knee flexion ROM (p < 0.001, η = 0.36) during both types of WLs, whereas the RT group showed a higher eccentric Gmed amplitude (p < 0.001, η = 0.46) during all exercises and a higher eccentric VL amplitude (p < 0.001, η = 0.63) during contralateral WLs. Further differences were found between contralateral and ipsilateral WLs in both the RT (p < 0.001, η = 0.69) and NT groups (p < 0.001, η = 0.80), and contralateral WLs resulted in higher eccentric Gmed amplitudes. Contralateral WLs highly activated the Gmed (90% MVIC); therefore, this exercise can increase the Gmed maximal strength. The ipsilateral loading condition did not increase the Gmed or VM activity in the RT or NT group.

Differential involvement of ipsilateral and contralateral spinal cord astrocyte D-serine in carrageenan-induced mirror-image pain: role of σ1 receptors and astrocyte gap junctions.

PubMed

Choi, Hoon-Seong; Roh, Dae-Hyun; Yoon, Seo-Yeon; Choi, Sheu-Ran; Kwon, Soon-Gu; Kang, Suk-Yun; Moon, Ji-Young; Han, Ho-Jae; Beitz, Alvin J; Lee, Jang-Hern

2018-02-01

Although we have recently demonstrated that spinal astrocyte gap junctions mediate the development of mirror-image pain (MIP), it is still unclear which astrocyte-derived factor is responsible for the development of MIP and how its production is controlled. In the present study, we focused on the role of ipsilateral versus contralateral D-serine in the development of MIP and investigated the possible involvement of σ1 receptors and gap junctions in astrocyte D-serine production. Following carrageenan injection, mechanical allodynia was tested at various time points to examine the effect of individual drugs. Immunohistochemistry and Western blot analyses were performed to clarify the expression levels of spinal D-serine, serine racemase, σ1 receptors and connexin 43. The expression of ipsilateral D-serine was up-regulated during the early phase of inflammation, while contralateral D-serine increased during the later phase of inflammation. The pharmacological inhibition of D-serine during the early phase blocked the development of both ipsilateral and contralateral mechanical allodynia. However, the inhibition of D-serine during the later phase of inflammation blocked contralateral, but not ipsilateral mechanical allodynia. Furthermore, the inhibition of σ1 receptors during the earlier phase of inflammation inhibited the increase in ipsilateral D-serine. Conversely, the blockade of astrocyte gap junctions suppressed the up-regulation of contralateral D-serine during the later phase of inflammation. Spinal astrocyte D-serine plays an important role in the development of mirror-image pain. Furthermore, σ1 receptors and astrocyte gap junction signalling mediate ipsilateral and contralateral D-serine production respectively. © 2017 The British Pharmacological Society.

Chronic In Vivo Imaging Shows No Evidence of Dendritic Plasticity or Functional Remapping in the Contralesional Cortex after Stroke

PubMed Central

Johnston, David G.; Denizet, Marie; Mostany, Ricardo

2013-01-01

Most stroke survivors exhibit a partial recovery from their deficits. This presumably occurs because of remapping of lost capabilities to functionally related brain areas. Functional brain imaging studies suggest that remapping in the contralateral uninjured cortex might represent a transient stage of compensatory plasticity. Some postmortem studies have also shown that cortical lesions, including stroke, can trigger dendritic plasticity in the contralateral hemisphere, but the data are controversial. We used longitudinal in vivo two-photon microscopy in the contralateral homotopic cortex to record changes in dendritic spines of layer 5 pyramidal neurons in green fluorescent protein mice. We could not detect de novo growth of dendrites or changes in the density or turnover of spines for up to 4 weeks after stroke. We also used intrinsic optical signal imaging to investigate whether the forepaw (FP) sensory representation is remapped to the spared homotopic cortex after stroke. Stimulation of the contralateral FP reliably produced strong intrinsic signals in the spared hemisphere, but we could never detect a signal with ipsilateral FP stimulation after stroke. This lack of contralateral plasticity at the level of apical dendrites of layer 5 pyramidal neurons and FP sensory maps suggests that the contralesional cortex may not contribute to functional recovery after stroke and that, at least in mice, the peri-infarct cortex plays the dominant role in postischemic plasticity. PMID:22499800

MMP-2 as an early synovial biomarker for cranial cruciate ligament disease in dogs.

PubMed

Boland, L; Danger, R; Cabon, Q; Rabillard, M; Brouard, S; Bouvy, B; Gauthier, O

2014-01-01

To measure the activity of matrix metalloproteinases (MMP)-2 and -9 in synovial fluid from the stifle joints of dogs with cranial cruciate ligament (CrCL) rupture and to compare that to values from contralateral stifle joints and dogs with clinically normal stifle joints. Additionally, the C-reactive protein (CRP) levels were also measured. Fourteen large breed dogs with unilateral CrCL rupture and 11 large breed normal dogs were included in this prospective clinical study. Synovial fluid was collected from CrCL-ruptured stifle joints, contralateral clinically normal stifle joints of the same dogs, and stifle joints of normal dogs. Serum was also collected. Synovial fluid activities of MMP-2 and MMP-9 and serum CRP level were measured. The MMP-2 activity in synovial fluid was significantly higher in CrCL-ruptured joints compared to contralateral joints and to stifles from normal dogs. There was no significant difference in activity of MMP-2 in contralateral joints of CrCL-ruptured dogs compared to normal dogs. Both serum CRP level and MMP-9 activity did not differ significantly between the studied conditions. It was confirmed that MMP-2 activity is significantly related to CrCL rupture, but there was a failure to demonstrate any significant increase in the contralateral joints compared to the stifle joints of normal dogs. The MMP-2 involvement in progressing CrCL disease still has to be defined.

Chronic in vivo imaging shows no evidence of dendritic plasticity or functional remapping in the contralesional cortex after stroke.

PubMed

Johnston, David G; Denizet, Marie; Mostany, Ricardo; Portera-Cailliau, Carlos

2013-04-01

Most stroke survivors exhibit a partial recovery from their deficits. This presumably occurs because of remapping of lost capabilities to functionally related brain areas. Functional brain imaging studies suggest that remapping in the contralateral uninjured cortex might represent a transient stage of compensatory plasticity. Some postmortem studies have also shown that cortical lesions, including stroke, can trigger dendritic plasticity in the contralateral hemisphere, but the data are controversial. We used longitudinal in vivo two-photon microscopy in the contralateral homotopic cortex to record changes in dendritic spines of layer 5 pyramidal neurons in green fluorescent protein mice. We could not detect de novo growth of dendrites or changes in the density or turnover of spines for up to 4 weeks after stroke. We also used intrinsic optical signal imaging to investigate whether the forepaw (FP) sensory representation is remapped to the spared homotopic cortex after stroke. Stimulation of the contralateral FP reliably produced strong intrinsic signals in the spared hemisphere, but we could never detect a signal with ipsilateral FP stimulation after stroke. This lack of contralateral plasticity at the level of apical dendrites of layer 5 pyramidal neurons and FP sensory maps suggests that the contralesional cortex may not contribute to functional recovery after stroke and that, at least in mice, the peri-infarct cortex plays the dominant role in postischemic plasticity.

Comparison of the inflammatory burden of truly asymptomatic carotid atheroma with atherosclerotic plaques contralateral to symptomatic carotid stenosis: an ultra small superparamagnetic iron oxide enhanced magnetic resonance study

PubMed Central

Tang, Tjun Y; Howarth, Simon P S; Miller, Sam R; Graves, Martin J; U‐King‐Im, Jean‐Marie; Trivedi, Rikin A; Li, Zhi Yong; Walsh, Stewart R; Brown, Andrew P; Kirkpatrick, Peter J; Gaunt, Michael E; Gillard, Jonathan H

2007-01-01

Background Inflammation is a recognised risk factor for the vulnerable atherosclerotic plaque. The aim of this study was to explore whether there is a difference in the degree of magnetic resonance (MR) defined inflammation using ultra small superparamagnetic iron oxide (USPIO) particles within carotid atheroma in completely asymptomatic individuals and the asymptomatic carotid stenosis contralateral to the symptomatic side. Methods 20 symptomatic patients with contralateral disease and 20 completely asymptomatic patients underwent multi‐sequence MR imaging before and 36 h after USPIO infusion. Images were manually segmented into quadrants and signal change in each quadrant was calculated following USPIO administration. Mean signal change was compared across all quadrants in the two groups. Results The mean percentage of quadrants showing signal loss was 53% in the contralateral group compared with 31% in completely asymptomatic individuals (p = 0.025). The mean percentages showing enhancement were 44% and 65%, respectively (p = 0.024). The mean signal difference between the two groups was 8.6% (95% CI 1.6% to 15.6%; p = 0.017). Conclusions Truly asymptomatic plaques seem to demonstrate inflammation but not to the extent of the contralateral asymptomatic stenosis to the symptomatic side. Inflammatory activity may be a significant risk factor in asymptomatic disease. PMID:17578854

Form-Deprivation Myopia in Chick Induces Limited Changes in Retinal Gene Expression

PubMed Central

McGlinn, Alice M.; Baldwin, Donald A.; Tobias, John W.; Budak, Murat T.; Khurana, Tejvir S.; Stone, Richard A.

2007-01-01

Purpose Evidence has implicated the retina as a principal controller of refractive development. In the present study, the retinal transcriptome was analyzed to identify alterations in gene expression and potential signaling pathways involved in form-deprivation myopia of the chick. Methods One-week-old white Leghorn chicks wore a unilateral image-degrading goggle for 6 hours or 3 days (n = 6 at each time). Total RNA from the retina/(retinal pigment epithelium) was used for expression profiling with chicken gene microarrays (Chicken GeneChips; Affymetrix, Santa Clara, CA). To identify gene expression level differences between goggled and contralateral nongoggled eyes, normalized microarray signal intensities were analyzed by the significance analysis of microarrays (SAM) approach. Differentially expressed genes were validated by real-time quantitative reverse transcription–polymerase chain reaction (qPCR) in independent biological replicates. Results Small changes were detected in differentially expressed genes in form-deprived eyes. In chickens that had 6 hours of goggle wear, downregulation of bone morphogenetic protein 2 and connective tissue growth factor was validated. In those with 3 days of goggle wear, downregulation of bone morphogenetic protein 2, vasoactive intestinal peptide, preopro-urotensin II–related peptide and mitogen-activated protein kinase phosphatase 2 was validated, and upregulation of endothelin receptor type B and interleukin-18 was validated. Conclusions Form-deprivation myopia, in its early stages, is associated with only minimal changes in retinal gene expression at the level of the transcriptome. While the list of validated genes is short, each merits further study for potential involvement in the signaling cascade mediating myopia development. PMID:17652709

The effect of midline crossing of lateral supraglottic cancer on contralateral cervical lymph node metastasis.

PubMed

Yılmaz, Taner; Süslü, Nilda; Atay, Gamze; Günaydın, Rıza Önder; Bajin, Münir Demir; Özer, Serdar

2015-05-01

The degree of midline crossing of lateral supraglottic cancer does not significantly change its rate of contralateral cervical metastasis. The rate of occult metastasis is too high to take the risk of contralateral regional recurrence. We support routine bilateral neck dissection even in lateral supraglottic cancers with no or minimal midline crossing. Data on the rate of contralateral cervical metastasis of laterally located supraglottic cancer, the effect of its degree of midline crossing on contralateral cervical metastasis, and its treatment are still controversial. This was a retrospective cohort, chart review involving 305 surgically treated patients with T1-3 squamous cell carcinoma of the supraglottic larynx. In all, 184 patients had bilateral neck dissection; 86 N0 contralateral necks were followed up. Thirty-five patients who needed postoperative radiation therapy because of the primary tumor or ipsilateral neck dissection specimen also received radiation therapy to the contralateral neck. The degree of midline crossing at the epiglottis was measured on a laryngectomy specimen with a ruler and expressed as 'no,' '<5 mm' or '≥5 mm.' The rates of occult and overall contralateral metastasis in our series were 16% and 28%, respectively. There was no statistically significant difference between contralateral neck metastasis and recurrence rates in the neck dissection, follow-up, and irradiation groups according to the degree of midline crossing.

Choosing the appropriate side for subcutaneous port catheter placement in patients with mastectomy: ipsilateral or contralateral?

PubMed

Nas, Omer Fatih; Hacikurt, Kadir; Kaya, Ahmet; Dogan, Nurullah; Sanal, Bekir; Ozkaya, Guven; Dundar, Halit Ziya; Erdogan, Cuneyt

2017-06-01

To evaluate long-term clinical follow-up results of implanting subcutaneous port catheters (SPCs) on ipsilateral or contralateral with mastectomy side in patients with axillary lymph node dissection. A total of 73 patients composed of ipsilateral (34 catheters) and contralateral (39 catheters) groups, with SPCs were included. All patients had lumpectomy or modified radical mastectomy for breast cancer. Ipsilateral and contralateral groups had similar patient characteristics. Five late complications were seen in the ipsilateral group and 2 late complications in the contralateral group. No statistical significant difference was seen between two groups in regard to late complications. Four complications of the ipsilateral group were classified as major group C and 1 as major group D, while 1 complication of the contralateral group was classified as minor group B and 1 as major group C according to Society of Interventional Radiology (SIR) classification. No statistical significant difference was seen between complication rates of two groups in regard to SIR classification. SPC related complications do not differ in regard to ipsilateral or contralateral side selection on mastectomized patients with breast cancer and lymph node dissection. SPCs can be implanted on ipsilateral or contralateral sides of the operation in these patients.

Unilateral lesion of dorsal hippocampus in adult rats impairs contralateral long-term potentiation in vivo and spatial memory in the early postoperative phase.

PubMed

Li, Hongjie; Wu, Xiaoyan; Bai, Yanrui; Huang, Yan; He, Wenting; Dong, Zhifang

2012-05-01

It is well documented that bilateral hippocampal lesions or unilateral hippocampal lesion at birth causes impairment of contralateral LTP and long-term memory. However, effects of unilateral hippocampal lesion in adults on contralateral in vivo LTP and memory are not clear. We here examined the influence of unilateral electrolytic dorsal hippocampal lesion in adult rats on contralateral LTP in vivo and spatial memory during different postoperative phases. We found that acute unilateral hippocampal lesion had no effect on contralateral LTP. However, contralateral LTP was impaired at 1 week after lesion, and was restored to the control level at postoperative week 4. Similarly, spatial memory was also impaired at postoperative week 1, and was restored at postoperative week 4. In addition, the rats at postoperative week 1 showed stronger spatial exploratory behavior in a novel open-field environment. The sham operation had no effects on contralateral LTP, spatial memory and exploration at either postoperative week 1 or week 4. These results suggest that unilateral dorsal hippocampal lesion in adult rats causes transient contralateral LTP impairment and spatial memory deficit. Copyright © 2012 Elsevier B.V. All rights reserved.

Simultaneous cranioplasty and subdural-peritoneal shunting for contralateral symptomatic subdural hygroma following decompressive craniectomy.

PubMed

Lin, Muh-Shi; Chen, Tzu-Hsuan; Kung, Woon-Man; Chen, Shuo-Tsung

2015-01-01

Contralateral subdural hygroma caused by decompressive craniectomy tends to combine with external cerebral herniation, causing neurological deficits. Nine patients who underwent one-stage, simultaneous cranioplasty and contralateral subdural-peritoneal shunting were included in this study. Clinical outcome was assessed by Glasgow Outcome Scale as well as Glasgow Coma Scale, muscle power scoring system, and complications. Postoperative computed tomography scans demonstrated completely resolved subdural hygroma and reversed midline shifts, indicating excellent outcome. Among these 9 patients, 4 patients (44%) had improved GOS following the proposed surgery. Four out of 4 patients with lethargy became alert and orientated following surgical intervention. Muscle strength improved significantly 5 months after surgery in 7 out of 7 patients with weakness. Two out of 9 patients presented with drowsiness due to hydrocephalus at an average time of 65 days after surgery. Double gradient shunting is useful to eliminate the respective hydrocephalus and contralateral subdural hygroma. The described surgical technique is effective in treating symptomatic contralateral subdural hygroma following decompressive craniectomy and is associated with an excellent structural and functional outcome. However, subdural-peritoneal shunting plus cranioplasty thoroughly resolves the subdural hygroma collection, which might deteriorate the cerebrospinal fluid circulation, leading to hydrocephalus.

Women's preferences for contralateral prophylactic mastectomy: An investigation using protection motivation theory.

PubMed

Tesson, Stephanie; Richards, Imogen; Porter, David; Phillips, Kelly-Anne; Rankin, Nicole; Musiello, Toni; Marven, Michelle; Butow, Phyllis

2016-05-01

Most women diagnosed with unilateral breast cancer without BRCA1 or BRCA2 mutations are at low risk of contralateral breast cancer. Contralateral Prophylactic Mastectomy (CPM) decreases the relative risk of contralateral breast cancer, but may not increase life expectancy; yet international uptake is increasing. This study applied protection motivation theory (PMT) to determine factors associated with women's intentions to undergo CPM. Three hundred eighty-eight women previously diagnosed with unilateral breast cancer and of negative or unknown BRCA1 or BRCA2 status were recruited from an advocacy group's research database. Participants completed measures of PMT constructs based on a common hypothetical CPM decision-making scenario. PMT constructs explained 16% of variance in intentions to undergo CPM. Response efficacy (CPM's advantages) and response costs (CPM's disadvantages) were unique individual predictors of intentions. Decision-making appears driven by considerations of the psychological, cosmetic and emotional advantages and disadvantages of CPM. Overestimations of threat to life from contralateral breast cancer and survival benefit from CPM also appear influential factors. Patients require balanced and medically accurate information regarding the pros and cons of CPM, survival rates, and recurrence risks to ensure realistic and informed decision-making.

Topographic organization, number, and laminar distribution of callosal cells connecting visual cortical areas 17 and 18 of normally pigmented and Siamese cats.

PubMed

Berman, N E; Grant, S

1992-07-01

The callosal connections between visual cortical areas 17 and 18 in adult normally pigmented and "Boston" Siamese cats were studied using degeneration methods, and by transport of WGA-HRP combined with electrophysiological mapping. In normal cats, over 90% of callosal neurons were located in the supragranular layers. The supragranular callosal cell zone spanned the area 17/18 border and extended, on average, some 2-3 mm into both areas to occupy a territory which was roughly co-extensive with the distribution of callosal terminations in these areas. The region of the visual field adjoining the vertical meridian that was represented by neurons in the supragranular callosal cell zone was shown to increase systematically with decreasing visual elevation. Thus, close to the area centralis, receptive-field centers recorded from within this zone extended only up to 5 deg into the contralateral hemifield but at elevations of -10 deg and -40 deg they extended as far as 8 deg and 14 deg, respectively, into this hemifield. This suggests an element of visual non-correspondence in the callosal pathway between these cortical areas, which may be an essential substrate for "coarse" stereopsis at the visual midline. In the Siamese cats, the callosal cell and termination zones in areas 17 and 18 were expanded in width compared to the normal animals, but the major components were less robust. The area 17/18 border was often devoid of callosal axons and, in particular, the number of supragranular layer neurons participating in the pathway were drastically reduced, to only about 25% of those found in the normally pigmented adults. The callosal zones contained representations of the contralateral and ipsilateral hemifields that were roughly mirror-symmetric about the vertical meridian, and both hemifield representations increased with decreasing visual elevation. The extent and severity of the anomalies observed were similar across individual cats, regardless of whether a strabismus was also present. The callosal pathway between these visual cortical areas in the Siamese cat has been considered "silent," since nearly all neurons within its territory are activated only by the contralateral eye. The paucity of supragranular pyramidal neurons involved in the pathway may explain this silence.

Is prophylactic fixation a cost-effective method to prevent a future contralateral fragility hip fracture?

PubMed

Faucett, Scott C; Genuario, James W; Tosteson, Anna N A; Koval, Kenneth J

2010-02-01

: A previous hip fracture more than doubles the risk of a contralateral hip fracture. Pharmacologic and environmental interventions to prevent hip fracture have documented poor compliance. The purpose of this study was to examine the cost-effectiveness of prophylactic fixation of the uninjured hip to prevent contralateral hip fracture. : A Markov state-transition model was used to evaluate the cost and quality-adjusted life-years (QALYs) for unilateral fixation of hip fracture alone (including internal fixation or arthroplasty) compared with unilateral fixation and contralateral prophylactic hip fixation performed at the time of hip fracture or unilateral fixation and bilateral hip pad protection. Prophylactic fixation involved placement of a cephalomedullary nail in the uninjured hip and was initially assumed to have a relative risk of a contralateral fracture of 1%. Health states included good health, surgery-related complications requiring a second operation (infection, osteonecrosis, nonunion, and malunion), fracture of the uninjured hip, and death. The primary outcome measure was the incremental cost-effectiveness ratio estimated as cost per QALY gained in 2006 US dollars with incremental cost-effectiveness ratios below $50,000 per QALY gained considered cost-effective. Sensitivity analyses evaluated the impact of patient age, annual mortality and complication rates, intervention effectiveness, utilities, and costs on the value of prophylactic fixation. : In the baseline analysis, in a 79-year-old woman, prophylactic fixation was not found to be cost-effective (incremental cost-effectiveness ratio = $142,795/QALY). However, prophylactic fixation was found to be a cost-effective method to prevent contralateral hip fracture in: 1) women 71 to 75 years old who had 30% greater relative risk for a contralateral fracture; and 2) women younger than age 70 years. Cost-effectiveness was greater when the additional costs of prophylaxis were less than $6000. However, for most analyses, the success of prophylactic fixation was highly sensitive to the effectiveness and the relative morbidity and mortality of the additional procedure. : Prophylactic fixation with a cephalomedullary nail was not found to be cost-effective for the average older woman who sustained a hip fracture. However, it may be appropriate for select patient populations. The study supports the need for basic science and clinical trials investigating the effectiveness of prophylactic fixation for patient populations at higher lifetime risk for contralateral hip fracture.

Hypothalamic hypocretinergic/orexinergic neurons projecting to the oral pontine rapid eye movement sleep inducing site in the cat.

PubMed

García-García, Berta; Reinoso-Suárez, Fernando; Rodrigo-Angulo, Margarita L

2013-05-01

The cat ventral oral pontine reticular nucleus (vRPO) is responsible for the generation and maintenance of rapid eye movement (REM) sleep. Hypothalamic neurons containing the peptide hypocretin-1 (also called orexin-A) which will be herewith defined as orexinergic (Orx) neurons, occupy a pre-eminent place in the integration and stabilization of arousal networks as well as in the physiopathology of narcolepsy/cataplexy. In the previous investigations, low-volume and dose microinjections of hypocretin-1 in cat vRPO produced a specific and significant suppression of REM sleep. The aim of this study is to map the hypothalamic Orx neurons that project to the vRPO and suppress REM sleep generation in the cat. Five adult cats received microinjections of the retrograde tracer cholera toxin (CTb) into the vRPO. Brains were processed employing both CTb staining and antiorexin-A immunocytochemistry techniques. A large number of double-labeled neurons (Orx-CTb) intermingled with the single CTb-positive and single Orx neurons were detected in the ipsilateral lateral, perifornical, dorsal, anterior, perimammillothalamic, and posterior hypothalamic areas but were very scarce in the paraventricular, dorsomedial, ventromedial, and periventricular hypothalamic nuclei. A considerable number of double-labeled neurons were also observed in both the dorsal and the lateral hypothalamic areas in the contralateral hypothalamus. Our results suggest that the widely distributed Orx neuronal hypothalamic groups could physiologically inhibit REM sleep generation in vRPO. Copyright © 2013 Wiley Periodicals, Inc.

Screening for carcinoma in situ in the contralateral testicle in patients with testicular cancer: a population-based study.

PubMed

Kier, M G G; Lauritsen, J; Almstrup, K; Mortensen, M S; Toft, B G; Rajpert-De Meyts, E; Skakkebaek, N E; Rørth, M; von der Maase, H; Agerbaek, M; Holm, N V; Andersen, K K; Dalton, S O; Johansen, C; Daugaard, G

2015-04-01

Screening programmes for contralateral carcinoma in situ (CIS) testis in patients with unilateral germ-cell cancer (GCC) have never been evaluated. We investigated the effect of screening for contralateral CIS in a large nation-wide, population-based study. A contralateral single-site biopsy was offered to 4130 patients in whom GCC had been diagnosed in 1984-2007 (screened cohort); 462 patients in whom GCC was diagnosed in 1984-1988 comprised the unscreened cohort. Cases with CIS were offered radiotherapy. Initially CIS-negative biopsies in patients with metachronous GCC were revised according to today's standards. Risk for metachronous GCC was estimated using cumulative incidence and the Cox proportional hazards model. In the screened cohort, contralateral CIS was found in 181 (4.4%) patients. The cumulative incidence of metachronous GCC after 20 years was 1.9% in the screened cohort and 3.1% in the unscreened cohort (P = 0.097), hazard ratio (HR) for the unscreened cohort: 1.59 (P = 0.144). Expert revision with contemporary methodology of CIS-negative biopsy samples from patients with metachronous cancer revealed CIS in 17 out of 45 (38%) cases. Decreased risks for metachronous GCC were related to older age at diagnosis (HR 0.52 per 10 years, P < 0.001) and chemotherapy (HR 0.35, P = 0.002). Limitations include the small number of patients in the unscreened cohort and the retrospective study design. Our evaluation of a national population-based screening programme for contralateral CIS in patients with testicular cancer showed no significant difference in the risk for metachronous GCC between a screened and an unscreened cohort. Single-site biopsy including modern immunohistochemistry does not identify all cases of CIS. © The Author 2014. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Automatic gain control of neural coupling during cooperative hand movements.

PubMed

Thomas, F A; Dietz, V; Schrafl-Altermatt, M

2018-04-13

Cooperative hand movements (e.g. opening a bottle) are controlled by a task-specific neural coupling, reflected in EMG reflex responses contralateral to the stimulation site. In this study the contralateral reflex responses in forearm extensor muscles to ipsilateral ulnar nerve stimulation was analyzed at various resistance and velocities of cooperative hand movements. The size of contralateral reflex responses was closely related to the level of forearm muscle activation required to accomplish the various cooperative hand movement tasks. This indicates an automatic gain control of neural coupling that allows a rapid matching of corrective forces exerted at both sides of an object with the goal 'two hands one action'.

Suppression of Retinal Neovascularization in vivo by Inhibition of Vascular Endothelial Growth Factor (VEGF) Using Soluble VEGF-Receptor Chimeric Proteins

NASA Astrophysics Data System (ADS)

Aiello, Lloyd Paul; Pierce, Eric A.; Foley, Eliot D.; Takagi, Hitoshi; Chen, Helen; Riddle, Lavon; Ferrara, Napoleone; King, George L.; Smith, Lois E. H.

1995-11-01

The majority of severe visual loss in the United States results from complications associated with retinal neovascularization in patients with ischemic ocular diseases such as diabetic retinopathy, retinal vein occlusion, and retinopathy of prematurity. Intraocular expression of the angiogenic protein vascular endothelial growth factor (VEGF) is closely correlated with neovascularization in these human disorders and with ischemia-induced retinal neovascularization in mice. In this study, we evaluated whether in vivo inhibition of VEGF action could suppress retinal neovascularization in a murine model of ischemic retinopathy. VEGF-neutralizing chimeric proteins were constructed by joining the extracellular domain of either human (Flt) or mouse (Flk) high-affinity VEGF receptors with IgG. Control chimeric proteins that did not bind VEGF were also used. VEGF-receptor chimeric proteins eliminated in vitro retinal endothelial cell growth stimulation by either VEGF (P < 0.006) or hypoxic conditioned medium (P < 0.005) without affecting growth under nonstimulated conditions. Control proteins had no effect. To assess in vivo response, animals with bilateral retinal ischemia received intravitreal injections of VEGF antagonist in one eye and control protein in the contralateral eye. Retinal neovascularization was quantitated histologically by a masked protocol. Retinal neovascularization in the eye injected with human Flt or murine Flk chimeric protein was reduced in 100% (25/25; P < 0.0001) and 95% (21/22; P < 0.0001) of animals, respectively, compared to the control treated eye. This response was evident after only a single intravitreal injection and was dose dependent with suppression of neovascularization noted after total delivery of 200 ng of protein (P < 0.002). Reduction of histologically evident neovascular nuclei per 6-um section averaged 47% ± 4% (P < 0.001) and 37% ± 2% (P < 0.001) for Flt and Flk chimeric proteins with maximal inhibitory effects of 77% and 66%, respectively. No retinal toxicity was observed by light microscopy. These data demonstrate VEGF's causal role in retinal angiogenesis and prove the potential of VEGF inhibition as a specific therapy for ischemic retinal disease.

Occlusion, sternocleidomastoid muscle activity, and body sway: a pilot study in male astronauts.

PubMed

Sforza, Chiarella; Tartaglia, Gianluca M; Solimene, Umberto; Morgun, Valery; Kaspranskiy, Rustem R; Ferrario, Virgilio F

2006-01-01

The modifications induced by microgravity on the coordinated patterns of movement of the head, trunk, and limbs are reported on extensively. However, apparently there is little data on the masticatory muscles. In normal gravitational conditions, information from the neck and stomatognathic apparatus play a role in maintaining the body's balance and equilibrium. The current pilot study used normal gravity conditions to investigate the hypothesis of a functional coupling between occlusion and neck muscles and body postural oscillations. The immediate effect of modified occlusal surfaces on the contraction pattern of the sternocleidomastoid muscles during maximum voluntary clenching and on the oscillation of the center of foot pressure was analyzed in 11 male astronauts (aged 31-54 yrs). All subjects were healthy and free from pathologies of the neck and stomatognathic apparatus. Occlusal splints were prepared using impressions of their dental arches. The splints were modeled on the mandibular arch, had only posterior contacts, and were modified to obtain a more symmetric, standardized contraction of the masseter and temporalis muscles during teeth clenching. Surface EMG activity of the sternocleidomastoid muscles was recorded during a maximal voluntary clench with and without the splint. Sternocleidomastoid potentials were standardized as percent of the mean potentials recorded during a maximum contralateral rotation of the head, and the symmetry of the EMG waves of left- and right-side muscles was measured. Body sway was assessed with and without the splint, either with eyes open or closed. The variations of the center of foot pressure were analyzed through bivariate analysis, and the area of the 90% standard ellipse was computed. Within each visual condition (eyes open or closed), the difference between the areas of oscillation measured with and without the splint was computed. Muscular activity was more symmetric with the splint. The area of oscillation of the center of foot pressure was larger without the splint than with the splint, both with eyes open and eyes closed. The modifications, induced by the occlusal splint in the sternocleidomastoid muscles' symmetry, and center of foot pressure differential area with closed eyes, were significantly related (p < 0.05): the larger the increment in muscular symmetry, the smaller the area of oscillation with the splint as compared to without the splint. A functionally more symmetric maxillo-mandibular position resulted in a more symmetric sternocleidomastoid muscle contraction pattern and less body sway. Modifications in the contraction of the masticatory muscles may therefore affect the whole body.

Multichannel fiber-based diffuse reflectance spectroscopy for the rat brain exposed to a laser-induced shock wave: comparison between ipsi- and contralateral hemispheres

NASA Astrophysics Data System (ADS)

Miyaki, Mai; Kawauchi, Satoko; Okuda, Wataru; Nawashiro, Hiroshi; Takemura, Toshiya; Sato, Shunichi; Nishidate, Izumi

2015-03-01

Due to considerable increase in the terrorism using explosive devices, blast-induced traumatic brain injury (bTBI) receives much attention worldwide. However, little is known about the pathology and mechanism of bTBI. In our previous study, we found that cortical spreading depolarization (CSD) occurred in the hemisphere exposed to a laser- induced shock wave (LISW), which was followed by long-lasting hypoxemia-oligemia. However, there is no information on the events occurred in the contralateral hemisphere. In this study, we performed multichannel fiber-based diffuse reflectance spectroscopy for the rat brain exposed to an LISW and compared the results for the ipsilateral and contralateral hemispheres. A pair of optical fibers was put on the both exposed right and left parietal bone; white light was delivered to the brain through source fibers and diffuse reflectance signals were collected with detection fibers for both hemispheres. An LISW was applied to the left (ipsilateral) hemisphere. By analyzing reflectance signals, we evaluated occurrence of CSD, blood volume and oxygen saturation for both hemispheres. In the ipsilateral hemispheres, we observed the occurrence of CSD and long-lasting hypoxemia-oligemia in all rats examined (n=8), as observed in our previous study. In the contralateral hemisphere, on the other hand, no occurrence of CSD was observed, but we observed oligemia in 7 of 8 rats and hypoxemia in 1 of 8 rats, suggesting a mechanism to cause hypoxemia or oligemia or both that is (are) not directly associated with CSD in the contralateral hemisphere.

A systematic review of contralateral liver lobe hypertrophy after unilobar selective internal radiation therapy with Y90.

PubMed

Teo, Jin-Yao; Allen, John C; Ng, David C; Choo, Su-Pin; Tai, David W M; Chang, Jason P E; Cheah, Foong-Khoon; Chow, Pierce K H; Goh, Brian K P

2016-01-01

Curative liver resection is the treatment of choice for both primary and secondary liver malignancies. However, an inadequate future liver remnant (FLR) frequently precludes successful surgery. Portal vein embolization is the gold-standard modality for inducing hypertrophy of the FLR. In recent times, unilobar Yttrium-90 selective internal radiation therapy (SIRT) has been reported to induce hypertrophy of the contralateral, untreated liver lobe. The aim of this study is to review the current literature reporting on contralateral liver hypertrophy induced by unilobar SIRT. A systematic review of the English-language literature between 2000 and 2014 was performed using the search terms "Yttrium 90" OR "selective internal radiation therapy" OR "radioembolization" AND "hypertrophy". Seven studies, reporting on 312 patients, were included. Two hundred and eighty four patients (91.0%) received treatment to the right lobe. Two hundred and fifteen patients had hepatocellular carcinoma (HCC), 12 had intrahepatic cholangiocarcinoma, and 85 had liver metastases from mixed primaries. Y90 SIRT resulted in contralateral liver hypertrophy which ranged from 26 to 47% at 44 days-9 months. All studies were retrospective in nature, and heterogeneous, with substantial variations relative to pathology treated, underlying liver disease, dosage and delivery of Y90, number of treatment sessions and time to measurement of hypertrophy. Unilobar Y90 SIRT results in significant hypertrophy of the contralateral liver lobe. The rate of hypertrophy seems to be slower than that achieved by other methods. Copyright © 2015 International Hepato-Pancreato-Biliary Association Inc. Published by Elsevier Ltd. All rights reserved.

Contralateral Noise Stimulation Delays P300 Latency in School-Aged Children.

PubMed

Ubiali, Thalita; Sanfins, Milaine Dominici; Borges, Leticia Reis; Colella-Santos, Maria Francisca

2016-01-01

The auditory cortex modulates auditory afferents through the olivocochlear system, which innervates the outer hair cells and the afferent neurons under the inner hair cells in the cochlea. Most of the studies that investigated the efferent activity in humans focused on evaluating the suppression of the otoacoustic emissions by stimulating the contralateral ear with noise, which assesses the activation of the medial olivocochlear bundle. The neurophysiology and the mechanisms involving efferent activity on higher regions of the auditory pathway, however, are still unknown. Also, the lack of studies investigating the effects of noise on human auditory cortex, especially in peadiatric population, points to the need for recording the late auditory potentials in noise conditions. Assessing the auditory efferents in schoolaged children is highly important due to some of its attributed functions such as selective attention and signal detection in noise, which are important abilities related to the development of language and academic skills. For this reason, the aim of the present study was to evaluate the effects of noise on P300 responses of children with normal hearing. P300 was recorded in 27 children aged from 8 to 14 years with normal hearing in two conditions: with and whitout contralateral white noise stimulation. P300 latencies were significantly longer at the presence of contralateral noise. No significant changes were observed for the amplitude values. Contralateral white noise stimulation delayed P300 latency in a group of school-aged children with normal hearing. These results suggest a possible influence of the medial olivocochlear activation on P300 responses under noise condition.

Early Outcomes of Endoscopic Contralateral Foraminal and Lateral Recess Decompression via an Interlaminar Approach in Patients with Unilateral Radiculopathy from Unilateral Foraminal Stenosis.

PubMed

Kim, Hyeun Sung; Patel, Ravish; Paudel, Byapak; Jang, Jee-Soo; Jang, Il-Tae; Oh, Seong-Hoon; Park, Jae Eun; Lee, Sol

2017-12-01

Percutaneous endoscopic contralateral interlaminar lumbar foraminotomy (PECILF) for lumbar degenerative spinal stenosis is an established procedure. Better preservation of contralateral facet joint compared with that of the approach side has been shown with uniportal bilateral decompression. The aim of this retrospective case series was to analyze the early clinical and radiologic outcomes of stand-alone contralateral foraminotomy and lateral recess decompression using PECILF. Twenty-six consecutive patients with unilateral lower limb radiculopathy underwent contralateral foraminotomy and lateral recess decompression using PECILF. Their clinical outcomes were evaluated with visual analog scale leg pain score, Oswestry Disability Index, and the MacNab criteria. Completeness of decompression was documented with a postoperative magnetic resonance imaging. Mean age for the study group was 62.9 ± 9.2 years and the male/female ratio was 4:9. A total of 30 levels were decompressed, with 18 patients (60%) undergoing decompression at L4-L5, 9 at L5-S1 (30%), 2 at L3-L4 (6.7%), and 1 at L2-L3 (3.3%). Mean estimated blood loss was 27 ± 15 mL per level. Mean operative duration was 48 ± 12 minutes/level. Visual analog scale leg score improved from 7.7 ± 1 to 1.8 ± 0.8 (P < 0.0001). Oswestry Disability Index improved from 64.4 ± 5.8 to 21 ± 4.5 (P < 0.0001). Mean follow-up of the study was 13.7 ± 2.7 months. According to the MacNab criteria, 10 patients (38.5%) had good results, 14 patients (53.8%) had excellent results, and 2 patients (7.7%) had fair results. One patient required revision surgery. Facet-preserving contralateral foraminotomy and lateral recess decompression with PECILF is effective for treatment of lateral recess and foraminal stenosis. Thorough decompression with acceptable early clinical outcomes and minimal perioperative morbidity can be obtained with the contralateral endoscopic approach. Copyright © 2017 Elsevier Inc. All rights reserved.

Cross-education of muscular strength following unilateral resistance training: a meta-analysis.

PubMed

Manca, A; Dragone, D; Dvir, Z; Deriu, Franca

2017-11-01

Cross-education (CE) of strength is a well-known phenomenon whereby exercise of one limb can induce strength gains in the contralateral untrained limb. The only available meta-analyses on CE, which date back to a decade ago, estimated a modest 7.8% increase in contralateral strength following unilateral training. However, in recent years new evidences have outlined larger contralateral gains, which deserve to be systematically evaluated. Therefore, the aim of this meta-analysis was to appraise current data on CE and determine its overall magnitude of effect. Five databases were searched from inception to December 2016. All randomized controlled trials focusing on unilateral resistance training were carefully checked by two reviewers who also assessed the eligibility of the identified trials and extracted data independently. The risk of bias was assessed using the Cochrane Risk-of-Bias tool. Thirty-one studies entered the meta-analysis. Data from 785 subjects were pooled and subgroup analyses by body region (upper/lower limb) and type of training (isometric/concentric/eccentric/isotonic-dynamic) were performed. The pooled estimate of CE was a significant 11.9% contralateral increase (95% CI 9.1-14.8; p < 0.00001; upper limb: + 9.4%, p < 0.00001; lower limb: + 16.4%, p < 0.00001). Significant CE effects were induced by isometric (8.2%; p = 0.0003), concentric (11.3%; p < 0.00001), eccentric (17.7%; p = 0.003) and isotonic-dynamic training (15.9%; p < 0.00001), although a high risk of bias was detected across the studies. Unilateral resistance training induces significant contraction type-dependent gains in the contralateral untrained limb. Methodological issues in the included studies are outlined to provide guidance for a reliable quantification of CE in future studies.

External root resorption during orthodontic treatment in root-filled teeth and contralateral teeth with vital pulp: A clinical study of contributing factors.

PubMed

Lee, Yun Ju; Lee, Tae Yeon

2016-01-01

There is a lack of research to support the belief that root canal treatment can be considered for stopping or decreasing external apical root resorption (EARR). There is conflicting evidence as to whether root-filled teeth are more or less likely to experience EARR after orthodontic treatment. The purpose of this study was to compare the degree of EARR of root-filled teeth with that of contralateral teeth with vital pulp after fixed orthodontic treatment. The study sample consisted of 35 patients aged 25.23 ± 4.92 years who had at least 1 root-filled tooth before orthodontic treatment. Digital panoramic radiographs of each patient taken before and after orthodontic treatment were used to measure the EARR. The Student t test for matched pairs and the Pearson correlation analysis were applied. The mean EARR values were 0.22 (0.14, 0.35) for root-filled teeth and 0.87 (0.59, 1.31) for contralateral teeth with vital pulp, indicating significantly less EARR for root-filled teeth compared with the contralateral teeth with vital pulp after orthodontic treatment. EARR was influenced by the patient's age, treatment duration, treatment type, and periapical pathosis, but not by tooth type and sex. Root-filled teeth appear to be associated with significantly less EARR than are contralateral teeth with vital pulp. This study suggests that the possible complication of EARR in root-filled teeth may not be an important consideration in orthodontic treatment planning, and root canal treatment can be considered for stopping or decreasing EARR when severe EARR occurs during orthodontic treatment. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Perilesional and contralateral white matter evolution and integrity in patients with periventricular nodular heterotopia and epilepsy: a longitudinal diffusion tensor imaging study.

PubMed

Liu, W; Yan, B; An, D; Niu, R; Tang, Y; Tong, X; Gong, Q; Zhou, D

2017-12-01

This study aimed to assess the evolution of perinodular and contralateral white matter abnormalities in patients with periventricular nodular heterotopia (PNH) and epilepsy. Diffusion tensor imaging (DTI) (64 directions) and 3 T structural magnetic resonance imaging were performed in 29 PNH patients (mean age 27.3 years), and 16 patients underwent a second scan (average time between the two scans 1.1 years). Fractional anisotropy and mean diffusivity were measured within the perilesional and contralateral white matter. Longitudinal analysis showed that white matter located 10 mm from the focal nodule displayed characteristics intermediate to tissue 5 mm away, and normal-appearing white matter (NAWM) also established evolution profiles of perinodular white matter in different cortical lobes. Compared to 29 age- and sex-matched healthy controls, significant decreased fractional anisotropy and elevated mean diffusivity values were observed in regions 5 and 10 mm from nodules (P < 0.01), whilst DTI metrics of the remaining NAWM did not differ significantly from controls. Additionally, normal DTI metrics were shown in the contralateral region in patients with unilateral PNH. Periventricular nodular heterotopia is associated with microstructural abnormalities within the perilesional white matter and the extent decreases with increasing distance from the nodule. In the homologous contralateral region, white matter diffusion metrics were unchanged in unilateral PNH. These findings have clinical implications with respect to the medical and surgical interventions of PNH-related epilepsy. © 2017 EAN.

Blood-Brain Barrier Alterations Provide Evidence of Subacute Diaschisis in an Ischemic Stroke Rat Model

PubMed Central

Garbuzova-Davis, Svitlana; Rodrigues, Maria C. O.; Hernandez-Ontiveros, Diana G.; Tajiri, Naoki; Frisina-Deyo, Aric; Boffeli, Sean M.; Abraham, Jerry V.; Pabon, Mibel; Wagner, Andrew; Ishikawa, Hiroto; Shinozuka, Kazutaka; Haller, Edward; Sanberg, Paul R.; Kaneko, Yuji; Borlongan, Cesario V.

2013-01-01

Background Comprehensive stroke studies reveal diaschisis, a loss of function due to pathological deficits in brain areas remote from initial ischemic lesion. However, blood-brain barrier (BBB) competence in subacute diaschisis is uncertain. The present study investigated subacute diaschisis in a focal ischemic stroke rat model. Specific focuses were BBB integrity and related pathogenic processes in contralateral brain areas. Methodology/Principal Findings In ipsilateral hemisphere 7 days after transient middle cerebral artery occlusion (tMCAO), significant BBB alterations characterized by large Evans Blue (EB) parenchymal extravasation, autophagosome accumulation, increased reactive astrocytes and activated microglia, demyelinization, and neuronal damage were detected in the striatum, motor and somatosensory cortices. Vascular damage identified by ultrastuctural and immunohistochemical analyses also occurred in the contralateral hemisphere. In contralateral striatum and motor cortex, major ultrastructural BBB changes included: swollen and vacuolated endothelial cells containing numerous autophagosomes, pericyte degeneration, and perivascular edema. Additionally, prominent EB extravasation, increased endothelial autophagosome formation, rampant astrogliosis, activated microglia, widespread neuronal pyknosis and decreased myelin were observed in contralateral striatum, and motor and somatosensory cortices. Conclusions/Significance These results demonstrate focal ischemic stroke-induced pathological disturbances in ipsilateral, as well as in contralateral brain areas, which were shown to be closely associated with BBB breakdown in remote brain microvessels and endothelial autophagosome accumulation. This microvascular damage in subacute phase likely revealed ischemic diaschisis and should be considered in development of treatment strategies for stroke. PMID:23675488

Restoration of the Patient-Specific Anatomy of the Proximal and Distal Parts of the Humerus: Statistical Shape Modeling Versus Contralateral Registration Method.

PubMed

Vlachopoulos, Lazaros; Lüthi, Marcel; Carrillo, Fabio; Gerber, Christian; Székely, Gábor; Fürnstahl, Philipp

2018-04-18

In computer-assisted reconstructive surgeries, the contralateral anatomy is established as the best available reconstruction template. However, existing intra-individual bilateral differences or a pathological, contralateral humerus may limit the applicability of the method. The aim of the study was to evaluate whether a statistical shape model (SSM) has the potential to predict accurately the pretraumatic anatomy of the humerus from the posttraumatic condition. Three-dimensional (3D) triangular surface models were extracted from the computed tomographic data of 100 paired cadaveric humeri without a pathological condition. An SSM was constructed, encoding the characteristic shape variations among the individuals. To predict the patient-specific anatomy of the proximal (or distal) part of the humerus with the SSM, we generated segments of the humerus of predefined length excluding the part to predict. The proximal and distal humeral prediction (p-HP and d-HP) errors, defined as the deviation of the predicted (bone) model from the original (bone) model, were evaluated. For comparison with the state-of-the-art technique, i.e., the contralateral registration method, we used the same segments of the humerus to evaluate whether the SSM or the contralateral anatomy yields a more accurate reconstruction template. The p-HP error (mean and standard deviation, 3.8° ± 1.9°) using 85% of the distal end of the humerus to predict the proximal humeral anatomy was significantly smaller (p = 0.001) compared with the contralateral registration method. The difference between the d-HP error (mean, 5.5° ± 2.9°), using 85% of the proximal part of the humerus to predict the distal humeral anatomy, and the contralateral registration method was not significant (p = 0.61). The restoration of the humeral length was not significantly different between the SSM and the contralateral registration method. SSMs accurately predict the patient-specific anatomy of the proximal and distal aspects of the humerus. The prediction errors of the SSM depend on the size of the healthy part of the humerus. The prediction of the patient-specific anatomy of the humerus is of fundamental importance for computer-assisted reconstructive surgeries.

Carotid artery stiffness in patients with symptomatic carotid artery disease with contralateral asymptomatic carotid artery disease and in patients with bilateral asymptomatic carotid artery disease: a cine phase-contrast carotid MR study.

PubMed

Sadat, Umar; Usman, Ammara; Howarth, Simon P S; Tang, Tjun Y; Alam, Fahreyar; Graves, Martin J; Gillard, Jonathan H

2014-04-01

Atherosclerosis is a systemic inflammatory disease that may affect multiple arterial beds simultaneously. Vascular distensibility is increasingly used in the clinical assessment of patients with atherosclerotic disease. In this study, we assess distensibility of symptomatic atherosclerotic carotid artery and of contralateral asymptomatic side. We also investigate the distensibility of bilaterally asymptomatic atherosclerotic carotid arteries using cine phase-contrast carotid magnetic resonance (MR) imaging. Nineteen patients with bilateral carotid artery disease underwent cine phase-contrast carotid imaging on a 1.5 T MR system. Ten patients had ipsilateral symptomatic carotid artery disease and contralateral asymptomatic stenosis. Nine additional patients with bilateral asymptomatic carotid artery disease constituted historical control group. Cine phase-contrast MR imaging acquired at the common carotid artery, maximum luminal stenosis, and internal carotid artery was used to determine carotid distensibility bilaterally for carotid arteries in both patient groups. Symptomatic carotid arteries were found to be significantly less distensible (mean distensibility coefficient [DC] 35.4 ± 6.12 × 10(-3)/kPa) than the contralateral asymptomatic vessels (mean DC 54.4 ± 7.88 × 10(-3)/kPa, P = .03) at the level of the common carotid artery. A similar trend of high distensibility for asymptomatic side in the area of maximum stenosis and the internal carotid artery was seen, but it was not found to be statistically significant. Plaque burden was comparable between the 2 groups at all locations. DC was comparable for patients with bilateral asymptomatic carotid artery stenoses. Distensibility of bilaterally asymptomatic carotid arteries was greater than that of asymptomatic carotid artery contralateral to the symptomatic side. Symptomatic carotid artery is stiffer than the contralateral asymptomatic side, despite comparable plaque burden. Patients with bilateral asymptomatic carotid artery disease have comparable stiffness. Larger studies are warranted to further investigate the findings of this MR study. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

High infusion pressure in conjunction with vitreous surgery alters the morphology and function of the retina of rabbits.

PubMed

Minami, Masahiro; Oku, Hidehiro; Okuno, Takashi; Fukuhara, Masayuki; Ikeda, Tsunehiko

2007-09-01

To investigate the effects of high infusion pressure in conjunction with pars plana vitrectomy (PPV) on retinal morphology and function in rabbits. Pars plana vitrectomy was performed under urethane (0.8 mg/kg) anaesthesia in the right eye of albino rabbits following phacoemulsification and aspiration (PEA). The left eyes were not touched. After PEA, the animals were divided into two groups. In six eyes, intraocular pressure (IOP) was increased to 80 mmHg for 30 mins (high-pressure group) and in five eyes IOP was maintained at 40 mmHg for 30 mins (low-pressure group). The IOPs were regulated by the height of the bottle of balanced salt solution (BSS) and monitored with a pressure transducer. After the pressure elevation, vitreous fluid was collected to measure the glutamate concentration. Then, PPV was performed for 15 mins in both groups under an infusion pressure of 40 mmHg. In five additional rabbits, PEA alone was performed in the right eye, and vitreous fluid was collected (PEA group). Functional alterations were assessed by recording visual evoked potentials (VEPs) and electroretinograms (ERGs). Ten days after the IOP changes, the animals were killed with intravenous pentobarbital sodium and the eyes were prepared for histological analysis. Damage to retinal ganglion cells (RGCs) was quantified by counting the number of cells in the ganglion cell layer (GCL). The contralateral eyes in the high-pressure group served as controls (n = 6). The mean implicit time (IT) of the VEPs in the high-pressure group was significantly longer than that before the IOP elevation, by 114-124% (p < 0.05, paired t-test), and also than that of control eyes (p < 0.05, anova followed by t-test). No significant changes in the VEPs were detected in either the low-pressure group or the PEA group. There were significantly fewer cells in the GCL in the high-pressure group (24.7/mm) than in the control animals (41.4/mm; p < 0.05, Dunnett's test). The number of cells in the GCL in the low-pressure and PEA groups did not significantly differ to that in the controls. The amplitudes of the ERG a- and b-waves were not significantly changed (p > 0.05, paired t-test). These results suggest that high infusion pressure in conjunction with PPV leads to morphological and functional changes in the retina. The absence of ERG changes and presence of VEP changes suggest that these changes were due to damage to RGCs, which supports the morphological observations.

Evaluating the dose to the contralateral breast when using a dynamic wedge versus a regular wedge.

PubMed

Weides, C D; Mok, E C; Chang, W C; Findley, D O; Shostak, C A

1995-01-01

The incidence of secondary cancers in the contralateral breast after primary breast irradiation is several times higher than the incidence of first time breast cancer. Studies have shown that the scatter radiation to the contralateral breast may play a large part in the induction of secondary breast cancers. Factors that may contribute to the contralateral breast dose may include the use of blocks, the orientation of the field, and wedges. Reports have shown that the use of regular wedges, particularly for the medial tangential field, gives a significantly higher dose to the contralateral breast compared to an open field. This paper compares the peripheral dose outside the field using a regular wedge, a dynamic wedge, and an open field technique. The data collected consisted of measurements taken with patients, solid water and a Rando phantom using a Varian 2300CD linear accelerator. Ion chambers, thermoluminescent dosimeters (TLD), diodes, and films were the primary means for collecting the data. The measurements show that the peripheral dose outside the field using a dynamic wedge is close to that of open fields, and significantly lower than that of regular wedges. This information indicates that when using a medial wedge, a dynamic wedge should be used.

Backward masked fearful faces enhance contralateral occipital cortical activity for visual targets within the spotlight of attention

PubMed Central

Reinke, Karen S.; LaMontagne, Pamela J.; Habib, Reza

2011-01-01

Spatial attention has been argued to be adaptive by enhancing the processing of visual stimuli within the ‘spotlight of attention’. We previously reported that crude threat cues (backward masked fearful faces) facilitate spatial attention through a network of brain regions consisting of the amygdala, anterior cingulate and contralateral visual cortex. However, results from previous functional magnetic resonance imaging (fMRI) dot-probe studies have been inconclusive regarding a fearful face-elicited contralateral modulation of visual targets. Here, we tested the hypothesis that the capture of spatial attention by crude threat cues would facilitate processing of subsequently presented visual stimuli within the masked fearful face-elicited ‘spotlight of attention’ in the contralateral visual cortex. Participants performed a backward masked fearful face dot-probe task while brain activity was measured with fMRI. Masked fearful face left visual field trials enhanced activity for spatially congruent targets in the right superior occipital gyrus, fusiform gyrus and lateral occipital complex, while masked fearful face right visual field trials enhanced activity in the left middle occipital gyrus. These data indicate that crude threat elicited spatial attention enhances the processing of subsequent visual stimuli in contralateral occipital cortex, which may occur by lowering neural activation thresholds in this retinotopic location. PMID:20702500

Contralateral Deep Vein Thrombosis after Iliac Vein Stent Placement in Patients with May-Thurner Syndrome.

PubMed

Le, Trong Binh; Lee, Taeg Ki; Park, Keun-Myoung; Jeon, Yong Sun; Hong, Kee Chun; Cho, Soon Gu

2018-04-25

To investigate the incidence and potential causes of contralateral deep vein thrombosis (DVT) after common iliac vein (CIV) stent placement in patients with May-Thurner syndrome (MTS). Data of 111 patients (women: 73%) who had CIV stent implantation for symptomatic MTS at a single center were retrospectively analyzed. Mean patient age was 63.1 ± 15.2 years. Median follow-up was 36 months (range, 1-142 months). Stent location was determined by venogram and classified as extended to the inferior vena cava (IVC), covered the confluence, or confined to the iliac vein. Potential causes of contralateral DVT were presumed based on venographic findings. The relationship between stent location and contralateral DVT was analyzed. Ten patients (9%, men/women: 4/6) exhibited contralateral DVT at a median timing of 40 months (range, 6-98 months). Median age was 69 years (range, 42-85 years). Median follow-up was 73.5 months (range, 20-134 months). Potential causes were venous intimal hyperplasia (VIH) (n = 7), "jailing" (n = 2), and indeterminate (n = 1). All patients with VIH had previous CIV stents overextended to the IVC. Overextension of CIV stent was associated with contralateral DVT (P < .001). The primary patency rate of the contralateral CIV stent was 70% at 20 months. Contralateral DVT after CIV stent implantation has a relatively high incidence and often occurs late during follow-up. Overextension of the CIV stent to the IVC is associated with development of contralateral DVT, and VIH should be considered a potential cause. Copyright © 2018 SIR. Published by Elsevier Inc. All rights reserved.

Contralateral Hyperalgesia from Injection of Endothelin-1 into the Ipsilateral Paw Requires Efferent Conduction into the Contralateral Paw.

PubMed

Strichartz, Gary R; Khodorova, Alla; Wang, Jeffrey Chi-Fei; Chen, Yu-Wen; Huang, Chuan-Chin

2015-10-01

Contralateral hyperalgesia, occurring after unilateral injury, is usually explained by central sensitization in spinal cord and brain. We previously reported that injection of endothelin-1 (ET-1) into one rat hindpaw induces prolonged mechanical and chemical sensitization of the contralateral hindpaw. Here, we examined the role of contralateral efferent activity in this process. ET-1 (2 nmol, 10 μL) was injected subcutaneously into the plantar surface of right (ipsilateral) hindpaw (ILP), and the thermal response latency and mechanical threshold for nocifensive withdrawal were determined by the use of, respectively, plantar radiant heating and von Frey filaments, for both ILP and contralateral hindpaws (CLP). Either paw was anesthetized for 60 minutes by direct injection of bupivacaine (0.25%, 40 μL), 30 minutes before ET-1. Alternatively, the contralateral sciatic nerve was blocked for 6 to 12 hours by percutaneous injection of bupivacaine-releasing microspheres 30 minutes before injection of ET-1. Systemic actions of these bupivacaine formulations were simulated by subcutaneous injection at the nuchal midline. After the injection of ET-1, the mechanical threshold of both ILP and CLP decreased by 2 hours, appeared to be lowest around 24 hours, and recovered through 48 hours to preinjection baseline at 72 hours. These hypersensitive responses were suppressed by bupivacaine injected into the ipsilateral paw before ET-1. Injection of the CLP by bupivacaine also suppressed the hypersensitivity of the CLP at all test times, and that of the ILP, except at 2 hours when it increased the sensitivity. This same pattern of change occurred when the contralateral sciatic nerve was blocked by bupivacaine-releasing microspheres. The systemic actions of these bupivacaine formulations were much smaller and only reached significance at 24 hours post-ET-1. Thermal hypersensitivity after ET-1 injection also occurred in both ILP and CLP and showed the same pattern in response to the 2 contralateral anesthetic procedures. These results show that efferent transmission through the contralateral innervation into the paw is necessary for contralateral sensitization by ET-1, suggesting that the release of substances by distal nerve endings is involved. The release of substances in the periphery is essential for contralateral sensitization by ET-1 and may also contribute to secondary hyperalgesia, occurring at loci distant from the primary injury, that occurs after surgery or nerve damage.

Temperature-controlled in vivo ocular exposure to 1090-nm radiation suggests that near-infrared radiation cataract is thermally induced

NASA Astrophysics Data System (ADS)

Yu, Zhaohua; Schulmeister, Karl; Talebizadeh, Nooshin; Kronschläger, Martin; Söderberg, Per

2015-01-01

The damage mechanism for near-infrared radiation (IRR) induced cataract is unclear. Both a photochemical and a thermal mechanism were suggested. The current paper aims to elucidate a photochemical effect based on investigation of irradiance-exposure time reciprocity. Groups of 20 rats were unilaterally exposed to 96-W/cm2 IRR at 1090 nm within the dilated pupil accumulating 57, 103, 198, and 344 kJ/cm2, respectively. Temperature was recorded at the limbus of the exposed eye. Seven days after exposure, the lenses were macroscopically imaged and light scattering was quantitatively measured. The average maximum temperature increases for exposure times of 10, 18, 33, and 60 min were expressed as 7.0±1.1, 6.8±1.1, 7.6±1.3, and 7.4±1.1°C [CI (0.95)] at the limbus of the exposed eye. The difference of light scattering in the lenses between exposed and contralateral not-exposed eyes was 0.00±0.02, 0.01±0.03, -0.01±0.02, and -0.01±0.03 transformed equivalent diazepam concentration (tEDC), respectively, and no apparent morphological changes in the lens were observed. An exposure to 96-W/cm2 1090-nm IRR projected on the cornea within the dilated pupil accumulating radiant exposures up to 344 kJ/cm2 does not induce cataract if the temperature rise at the limbus is <8°C. This is consistent with a thermal damage mechanism for IRR-induced cataract.

Successful Medical Management of Presumptive Pythium insidiosum Keratitis.

PubMed

Ramappa, Muralidhar; Nagpal, Ritu; Sharma, Savitri; Chaurasia, Sunita

2017-04-01

To describe the previously unreported successful treatment of presumptive Pythium keratitis (PK) with medical therapy alone. A 42-year-old female homemaker presented to us with a 15-day history of pain and redness in the right eye after a trivial injury. Her vision was 20/80 at presentation. Slit-lamp biomicroscopy revealed a central, dense and dry-looking, grayish-white infiltrate reaching mid stroma. The infiltrate had feathery margins and was surrounded by multiple tentacle-like lesions and peripherally expanding pinhead-sized subepithelial lesions. The contralateral eye was essentially normal. Diagnostic corneal scraping on smears revealed broad, aseptate, hyaline filaments with ribbon-like folds; very characteristic of Pythium species. Confocal imaging revealed fungal filaments. Based on corroborative evidence, a diagnosis of presumptive PK was made. She was administered a combination therapy consisting of eye drop linezolid 0.2% 1 hourly, azithromycin 1% 2 hourly, atropine sulfate 1% thrice daily, and oral azithromycin 500 mg once daily for 3 days in a week. After initial worsening in the form of stromal expansion, regression of pinhead-sized lesions was seen with onset of scarring by as early as day 4 of intense medical therapy. The tentacle-like lesions did not worsen. On day 8, significant resolution was noted with scarring, and by the end of 2 weeks, the entire stromal lesion had scarred and complete resolution of expanding tentacles was observed in 3 weeks. Presumptive Pythium keratitis of the patient completely resolved with antibacterial treatment alone. It is pertinent for ophthalmologists to be aware of this new treatment regimen.

Surgical planning and innervation in pontine gaze palsy with ipsilateral esotropia.

PubMed

Somer, Deniz; Cinar, Fatma Gul; Kaderli, Ahmet; Ornek, Firdevs

2016-10-01

To discuss surgical intervention strategies among patients with horizontal gaze palsy with concurrent esotropia. Five consecutive patients with dorsal pontine lesions are presented. Each patient had horizontal gaze palsy with symptomatic diplopia as a consequence of esotropia in primary gaze and an anomalous head turn to attain single binocular vision. Clinical findings in the first 2 patients led us to presume there was complete loss of rectus muscle function from rectus muscle palsy. Based on this assumption, medial rectus recessions with simultaneous partial vertical muscle transposition (VRT) on the ipsilateral eye of the gaze palsy and recession-resection surgery on the contralateral eye were performed, resulting in significant motility limitation. Sequential recession-resection surgery without simultaneous VRT on the 3rd patient created an unexpected motility improvement to the side of gaze palsy, an observation differentiating rectus muscle palsy from paresis. Recession combined with VRT approach in the esotropic eye was abandoned on subsequent patients. Simultaneous recession-resection surgery without VRT in the next 2 patients resulted in alleviation of head postures, resolution of esotropia, and also substantial motility improvements to the ipsilateral hemifield of gaze palsy without limitations in adduction and vertical deviations. Ocular misalignment and abnormal head posture as a result of conjugate gaze palsy can be successfully treated by basic recession-resection surgery, with the advantage of increasing versions to the ipsilateral side of the gaze palsy. Improved motility after surgery presumably represents paresis, not "paralysis," with residual innervation in rectus muscles. Copyright © 2016 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

Contralateral versus ipsilateral rTMS of temporoparietal cortex for the treatment of chronic unilateral tinnitus: comparative study.

PubMed

Khedr, E M; Abo-Elfetoh, N; Rothwell, J C; El-Atar, A; Sayed, E; Khalifa, H

2010-07-01

Repetitive transcranial magnetic stimulation (rTMS) applied over left temporoparietal cortex has been reported to have a long-term therapeutic effect on tinnitus. We compare the impact of 1 and 25 Hz rTMS delivered either contralateral or ipsilateral to symptoms in 62 patients with unilateral chronic tinnitus. Patients were randomly assigned to one of four treatment groups: with stimulation at 1 or 25 Hz applied either ipsilateral or contralateral to symptoms. Two thousand pulses per session were given daily for 2 weeks. Changes in tinnitus handicap inventory (THI), self-rating scores of loudness, awareness, and annoyance were measured monthly for 10 months. Duration of residual inhibition (RI) and psychiatric morbidity were evaluated monthly for 3 months. There was a significant main effect of time (P < 0.0001) and a significant time x side interaction (P = 0.032) between groups. This was because of the fact that contralateral stimulation had a greater effect on THI than ipsilateral stimulation; it was also superior to left side stimulation (P = 0.027). Ratings of loudness improved more after contralateral rTMS (P = 0.037). Twenty patients had no remaining tinnitus after 3 months; the remainder had a significant increase in RI. Patients with the shortest history of tinnitus tended to respond better to rTMS. There was a significant correlation between changes in THI score and changes in Hamilton anxiety and depression scores. Ten daily treatments of 1 and 25 Hz rTMS contralateral to the side of tinnitus have a greater beneficial effect on symptoms than either ipsilateral or left side stimulation.

Neural Correlates of the Antinociceptive Effects of Stimulating the Anterior Pretectal Nucleus in Rats.

PubMed

Genaro, Karina; Prado, Wiliam A

2016-11-01

Stimulation-evoked antinociception (SEA) from the anterior pretectal nucleus (APtN) activates mechanisms that descend to the spinal cord through the dorsolateral funiculus, but the encephalic route followed by the descending pathways from the APtN is not completely known. This study evaluated the changes in the SEA from the APtN in the Wistar rat tail-flick test after lidocaine-induced neural block or N-methyl-d-aspartate-induced neurotoxic lesion of the deep mesencephalic nucleus (DpMe), tegmental pedunculopontine nucleus (PPTg), or lateral paragigantocellular nucleus (LPGi). The SEA from the APtN was less intense after neural block of the contralateral DpMe or PPTg or the ipsilateral LPGi, but was not changed by the neural block of the ipsilateral DpMe or PPTg or the contralateral LPGi. Antinociception did not occur when APtN stimulation was carried out 5 minutes after lidocaine or 6 days after N-methyl-d-aspartate injections into the contralateral DpMe and the ipsilateral LPGi, or into the contralateral PPTg and the ipsilateral LPGi. We conclude that the SEA from the APtN activates 2 descending pain inhibitory pathways, one relaying in the ipsilateral LPGi and another relaying sequentially in the contralateral DpMe and PPTg. The antinociceptive effect of the APtN stimulation involves 2 descending pathways: one relaying in the ipsilateral LPGi and another descending contralaterally via relays in the DpMe and PPTg. Copyright © 2016 American Pain Society. Published by Elsevier Inc. All rights reserved.

Optogenetic perturbations reveal the dynamics of an oculomotor integrator

PubMed Central

Gonçalves, Pedro J.; Arrenberg, Aristides B.; Hablitzel, Bastian; Baier, Herwig; Machens, Christian K.

2014-01-01

Many neural systems can store short-term information in persistently firing neurons. Such persistent activity is believed to be maintained by recurrent feedback among neurons. This hypothesis has been fleshed out in detail for the oculomotor integrator (OI) for which the so-called “line attractor” network model can explain a large set of observations. Here we show that there is a plethora of such models, distinguished by the relative strength of recurrent excitation and inhibition. In each model, the firing rates of the neurons relax toward the persistent activity states. The dynamics of relaxation can be quite different, however, and depend on the levels of recurrent excitation and inhibition. To identify the correct model, we directly measure these relaxation dynamics by performing optogenetic perturbations in the OI of zebrafish expressing halorhodopsin or channelrhodopsin. We show that instantaneous, inhibitory stimulations of the OI lead to persistent, centripetal eye position changes ipsilateral to the stimulation. Excitatory stimulations similarly cause centripetal eye position changes, yet only contralateral to the stimulation. These results show that the dynamics of the OI are organized around a central attractor state—the null position of the eyes—which stabilizes the system against random perturbations. Our results pose new constraints on the circuit connectivity of the system and provide new insights into the mechanisms underlying persistent activity. PMID:24616666

Saccade Generation by the Frontal Eye Fields in Rhesus Monkeys Is Separable from Visual Detection and Bottom-Up Attention Shift

PubMed Central

Lee, Kyoung-Min; Ahn, Kyung-Ha; Keller, Edward L.

2012-01-01

The frontal eye fields (FEF), originally identified as an oculomotor cortex, have also been implicated in perceptual functions, such as constructing a visual saliency map and shifting visual attention. Further dissecting the area’s role in the transformation from visual input to oculomotor command has been difficult because of spatial confounding between stimuli and responses and consequently between intermediate cognitive processes, such as attention shift and saccade preparation. Here we developed two tasks in which the visual stimulus and the saccade response were dissociated in space (the extended memory-guided saccade task), and bottom-up attention shift and saccade target selection were independent (the four-alternative delayed saccade task). Reversible inactivation of the FEF in rhesus monkeys disrupted, as expected, contralateral memory-guided saccades, but visual detection was demonstrated to be intact at the same field. Moreover, saccade behavior was impaired when a bottom-up shift of attention was not a prerequisite for saccade target selection, indicating that the inactivation effect was independent of the previously reported dysfunctions in bottom-up attention control. These findings underscore the motor aspect of the area’s functions, especially in situations where saccades are generated by internal cognitive processes, including visual short-term memory and long-term associative memory. PMID:22761923

Saccade generation by the frontal eye fields in rhesus monkeys is separable from visual detection and bottom-up attention shift.

PubMed

Lee, Kyoung-Min; Ahn, Kyung-Ha; Keller, Edward L

2012-01-01

The frontal eye fields (FEF), originally identified as an oculomotor cortex, have also been implicated in perceptual functions, such as constructing a visual saliency map and shifting visual attention. Further dissecting the area's role in the transformation from visual input to oculomotor command has been difficult because of spatial confounding between stimuli and responses and consequently between intermediate cognitive processes, such as attention shift and saccade preparation. Here we developed two tasks in which the visual stimulus and the saccade response were dissociated in space (the extended memory-guided saccade task), and bottom-up attention shift and saccade target selection were independent (the four-alternative delayed saccade task). Reversible inactivation of the FEF in rhesus monkeys disrupted, as expected, contralateral memory-guided saccades, but visual detection was demonstrated to be intact at the same field. Moreover, saccade behavior was impaired when a bottom-up shift of attention was not a prerequisite for saccade target selection, indicating that the inactivation effect was independent of the previously reported dysfunctions in bottom-up attention control. These findings underscore the motor aspect of the area's functions, especially in situations where saccades are generated by internal cognitive processes, including visual short-term memory and long-term associative memory.

A circuit for saccadic suppression in the primate brain

PubMed Central

Cavanaugh, James; McAlonan, Kerry; Wurtz, Robert H.

2017-01-01

Saccades should cause us to see a blur as the eyes sweep across a visual scene. Specific brain mechanisms prevent this by producing suppression during saccades. Neuronal correlates of such suppression were first established in the visual superficial layers of the superior colliculus (SC) and subsequently have been observed in cortical visual areas, including the middle temporal visual area (MT). In this study, we investigated suppression in a recently identified circuit linking visual SC (SCs) to MT through the inferior pulvinar (PI). We examined responses to visual stimuli presented just before saccades to reveal a neuronal correlate of suppression driven by a copy of the saccade command, referred to as a corollary discharge. We found that visual responses were similarly suppressed in SCs, PI, and MT. Within each region, suppression of visual responses occurred with saccades into both visual hemifields, but only in the contralateral hemifield did this suppression consistently begin before the saccade (~100 ms). The consistency of the signal along the circuit led us to hypothesize that the suppression in MT was influenced by input from the SC. We tested this hypothesis in one monkey by inactivating neurons within the SC and found evidence that suppression in MT depends on corollary discharge signals from motor SC (SCi). Combining these results with recent findings in rodents, we propose a complete circuit originating with corollary discharge signals in SCi that produces suppression in visual SCs, PI, and ultimately, MT cortex. NEW & NOTEWORTHY A fundamental puzzle in visual neuroscience is that we frequently make rapid eye movements (saccades) but seldom perceive the visual blur accompanying each movement. We investigated neuronal correlates of this saccadic suppression by recording from and perturbing a recently identified circuit from brainstem to cortex. We found suppression at each stage, with evidence that it was driven by an internally generated signal. We conclude that this circuit contributes to neuronal suppression of visual signals during eye movements. PMID:28003409

Contralateral Effects and Binaural Interactions in Dorsal Cochlear Nucleus

PubMed Central

2005-01-01

The dorsal cochlear nucleus (DCN) receives afferent input from the auditory nerve and is thus usually thought of as a monaural nucleus, but it also receives inputs from the contralateral cochlear nucleus as well as descending projections from binaural nuclei. Evidence suggests that some of these commissural and efferent projections are excitatory, whereas others are inhibitory. The goals of this study were to investigate the nature and effects of these inputs in the DCN by measuring DCN principal cell (type IV unit) responses to a variety of contralateral monaural and binaural stimuli. As expected, the results of contralateral stimulation demonstrate a mixture of excitatory and inhibitory influences, although inhibitory effects predominate. Most type IV units are weakly, if at all, inhibited by tones but are strongly inhibited by broadband noise (BBN). The inhibition evoked by BBN is also low threshold and short latency. This inhibition is abolished and excitation is revealed when strychnine, a glycine-receptor antagonist, is applied to the DCN; application of bicuculline, a GABAA-receptor antagonist, has similar effects but does not block the onset of inhibition. Manipulations of discrete fiber bundles suggest that the inhibitory, but not excitatory, inputs to DCN principal cells enter the DCN via its output pathway, and that the short latency inhibition is carried by commissural axons. Consistent with their respective monaural effects, responses to binaural tones as a function of interaural level difference are essentially the same as responses to ipsilateral tones, whereas binaural BBN responses decrease with increasing contralateral level. In comparison to monaural responses, binaural responses to virtual space stimuli show enhanced sensitivity to the elevation of a sound source in ipsilateral space but reduced sensitivity in contralateral space. These results show that the contralateral inputs to the DCN are functionally relevant in natural listening conditions, and that one role of these inputs is to enhance DCN processing of spectral sound localization cues produced by the pinna. PMID:16075189

Does the Dumbbell-Carrying Position Change the Muscle Activity in Split Squats and Walking Lunges?

PubMed Central

Lehnert, Michal; Zaatar, Amr M.Z.; Svoboda, Zdenek; Xaverova, Zuzana

2015-01-01

Abstract Stastny, P, Lehnert, M, Zaatar, AMZ, Svoboda, Z, and Xaverova, Z. Does the dumbbell-carrying position change the muscle activity in split squats and walking lunges? J Strength Cond Res 29(11): 3177–3187, 2015—The forward walking lunge (WL) and split squat (SSq) are similar exercises that have differences in the eccentric phase, and both can be performed in the ipsilateral or contralateral carrying conditions. This study aimed to determine the effects of dumbbell-carrying position on the kinematics and electromyographic (EMG) amplitudes of the gluteus medius (Gmed), vastus medialis (VM), vastus lateralis (VL), and biceps femoris during WLs and SSqs. The resistance-trained (RT) and the non–resistance-trained (NT) groups (both n = 14) performed ipsilateral WLs, contralateral WLs, ipsilateral SSqs, and contralateral SSqs in a randomized order in a simulated training session. The EMG amplitude, expressed as a percentage of the maximal voluntary isometric contraction (%MVIC), and the kinematics, expressed as the range of motion (ROM) of the hip and knee, were measured during 5 repetition maximum for both legs. The repeated measure analyses of variance showed significant differences between the RT and NT groups. The NT group showed a smaller knee flexion ROM (p < 0.001, η2 = 0.36) during both types of WLs, whereas the RT group showed a higher eccentric Gmed amplitude (p < 0.001, η2 = 0.46) during all exercises and a higher eccentric VL amplitude (p < 0.001, η2 = 0.63) during contralateral WLs. Further differences were found between contralateral and ipsilateral WLs in both the RT (p < 0.001, η2 = 0.69) and NT groups (p < 0.001, η2 = 0.80), and contralateral WLs resulted in higher eccentric Gmed amplitudes. Contralateral WLs highly activated the Gmed (90% MVIC); therefore, this exercise can increase the Gmed maximal strength. The ipsilateral loading condition did not increase the Gmed or VM activity in the RT or NT group. PMID:25968228

Role of Active Listening and Listening Effort on Contralateral Suppression of Transient Evoked Otoacousic Emissions.

PubMed

Kalaiah, Mohan Kumar; Theruvan, Nikhitha B; Kumar, Kaushlendra; Bhat, Jayashree S

2017-04-01

The present study aimed to investigate the effect of active listening and listening effort on the contralateral suppression of transient evoked otoacoustic emissions (CSTEOAEs). Twenty eight young adults participated in the study. Transient evoked otoacoustic emissions (TEOAEs) were recorded using 'linear' clicks at 60 dB peSPL, in three contralateral noise conditions. In condition 1, TEOAEs were obtained in the presence of white noise in the contralateral ear. While, in condition 2, speech was embedded into white noise at +3, -3, and -9 dB signal-to-noise ratio (SNR) and delivered to the contralateral ear. The SNR was varied to investigate the effect of listening effort on the CSTEOAE. In condition 3, speech was played backwards and embedded into white noise at -3 dB SNR. The conditions 1 and 3 served as passive listening condition and the condition 2 served as active listening condition. In active listening condition, the participants categorized the words in to two groups (e.g., animal and vehicle). CSTEOAE was found to be largest in the presence of white noise, and the amount of CSTEOAE was not significantly different between active and passive listening conditions (condition 2 and 3). Listening effort had an effect on the CSTEOAE, the amount of suppression increased with listening effort, when SNR was decreased from +3 dB to -3 dB. However, when the SNR was further reduced to -9 dB, there was no further increase in the amount of CSTEOAE, instead there was a reduction in the amount of suppression. The findings of the present study show that listening effort might affect CSTEOAE.

Role of Active Listening and Listening Effort on Contralateral Suppression of Transient Evoked Otoacousic Emissions

PubMed Central

Theruvan, Nikhitha B; Kumar, Kaushlendra; Bhat, Jayashree S

2017-01-01

Background and Objectives The present study aimed to investigate the effect of active listening and listening effort on the contralateral suppression of transient evoked otoacoustic emissions (CSTEOAEs). Subjects and Methods Twenty eight young adults participated in the study. Transient evoked otoacoustic emissions (TEOAEs) were recorded using ‘linear’ clicks at 60 dB peSPL, in three contralateral noise conditions. In condition 1, TEOAEs were obtained in the presence of white noise in the contralateral ear. While, in condition 2, speech was embedded into white noise at +3, −3, and −9 dB signal-to-noise ratio (SNR) and delivered to the contralateral ear. The SNR was varied to investigate the effect of listening effort on the CSTEOAE. In condition 3, speech was played backwards and embedded into white noise at −3 dB SNR. The conditions 1 and 3 served as passive listening condition and the condition 2 served as active listening condition. In active listening condition, the participants categorized the words in to two groups (e.g., animal and vehicle). Results CSTEOAE was found to be largest in the presence of white noise, and the amount of CSTEOAE was not significantly different between active and passive listening conditions (condition 2 and 3). Listening effort had an effect on the CSTEOAE, the amount of suppression increased with listening effort, when SNR was decreased from +3 dB to −3 dB. However, when the SNR was further reduced to −9 dB, there was no further increase in the amount of CSTEOAE, instead there was a reduction in the amount of suppression. Conclusions The findings of the present study show that listening effort might affect CSTEOAE. PMID:28417101

Is NAA reduction in normal contralateral cerebral tissue in stroke patients dependent on underlying risk factors?

PubMed

Walker, P M; Ben Salem, D; Giroud, M; Brunotte, F

2006-05-01

This retrospective study investigated the dependence of N-acetyl aspartate (NAA) ratios on risk factors for cerebral vasculopathy such as sex, age, hypertension, diabetes mellitus, carotid stenosis, and dyslipidaemia, which may have affected brain vessels and induced metabolic brain abnormalities prior to stroke. We hypothesise that in stroke patients metabolic alterations in the apparently normal contralateral brain are dependent on the presence or not of such risk factors. Fifty nine patients (31 male, 28 female: 58.8+/-16.1 years old) with cortical middle cerebral artery (MCA) territory infarction were included. Long echo time chemical shift imaging spectroscopy was carried out on a Siemens 1.5 T Magnetom Vision scanner using a multi-voxel PRESS technique. Metabolite ratios (NAA/choline, NAA/creatine, lactate/choline, etc) were studied using uni- and multivariate analyses with respect to common risk factors. The influence of age, stroke lesion size, and time since stroke was studied using a linear regression approach. Age, sex, and hypertension all appeared to individually influence metabolite ratios, although only hypertension was significant after multivariate analysis. In both basal ganglia and periventricular white matter regions in apparently normal contralateral brain, the NAA/choline ratio was significantly lower in hypertensive (1.37+/-0.16 and 1.50+/-0.19, respectively) than in normotensive patients (1.72+/-0.19 and 1.85+/-0.15, respectively). Regarding MCA infarction, contralateral tissue remote from the lesion behaves abnormally in the presence of hypertension, the NAA ratios in hypertensive patients being significantly lower. These data suggest that hypertension may compromise the use of contralateral tissue data as a reference for comparison with ischaemic tissue.

Contralateral limb during total contact casting. A dynamic pressure and thermometric analysis.

PubMed

Armstrong, D G; Liswood, P J; Todd, W F

1995-12-01

The authors draw attention to the importance of evaluation of the contralateral limb when treating unilateral sequelae secondary to distal symmetrical polyneuropathy. Plantar pressure measurements of the contralateral limb during total contact casting are reviewed. The results of thermometric evaluation before and after initiation of repetitive stress were reviewed. The results suggest that the patient walking in a total contact cast may experience a reduced focal pressure on the contralateral limb when compared with uncasted walking and three-point walking with crutches. Dermal thermometry may be a highly sensitive tool in evaluating even mild increases in repetitive stress. To explain this decrease in contralateral stress, the authors examine the features inherent to the total contact cast and propose the concept of proprioceptive stability.

[Glomerular changes in the contralateral kidney in the rat with experimental hydronephrosis].

PubMed

Castillo Bernabéu, R; Gázquez Ortiz, A; Bonillo Morales, A; Sierra Planas, M A; Ocaña Losa, J M; Romanos Lezcano, A

1985-10-31

We have studied under optic and electronmicroscopes the alterations of glomeruli in contralateral kidneys of rats with experimental hydronephrosis. Forty-eight Wistar rats, divided into two groups (control and experimental) were used. They were sacrificed 3, 6, 9 and 12 days after ureteral obstruction. There was a slight hypertrophy of glomeruli and hiperplasia of other components accompanied by a increased development of podocytes.

[The morphological features of the nervous and vascular components of communication systems in the cervix uteri].

PubMed

Dorosevich, A E; Bekhtereva, I A; Sudilovskaia, V V

2009-01-01

The investigation has indicated the presence of adrenergic and cholinergic autonomic nerve terminals (ANT) in the tissues of squamous cell carcinomas of the cervix uteri in a tumor growth area and contralaterally. Heterogeneity of the local neuromediator background in the tumor growth area and contralaterally may be explained, by studying the specific features of the cell microenvironment of ANT.

Adaptation of muscles of the lumbar spine to sudden imbalance in patients with lower back pain caused by military training.

PubMed

Gao, Ying; Shi, Jian-guo; Ye, Hong; Liu, Zhi-rong; Zheng, Long-bao; Ni, Zhi-ming; Fan, Liang-quan; Wang, Jian; Hou, Zhen-hai

2014-11-01

This study aims to investigate the effects of sudden load changes (expected and unexpected imbalance) on the activity of muscles of the lumbar spine and their central motor control strategy in military personnel with or without chronic low back pain (LBP). Bilateral sudden imbalance was examined (2 × 2 factorial design). The 117th PLA Hospital, Hangzhou, China Twenty-one male subjects with lower back pain and 21 male healthy control subjects were active members of the Nanjing Military Region land forces. Independent variables: LBP vs. healthy controls and imbalance anticipation (expected and unexpected imbalance). rapid reaction time (RRT) and intensity of rapid reaction (IRR) of bilateral lumbar (L3-L4) erector spinae (ES), lumbar (L5-S1) multifidus (MF), and abdominal external oblique muscles. Results Under expected or unexpected sudden imbalance conditions, subjects with LBP demonstrated significantly greater IRR than healthy controls in ipsilateral and contralateral ES and MF, respectively (P < 0.05 for all). IRR of contralateral ES was significantly larger than that of the ipsilateral ES. A significant group effect of RRT of both ipsilateral and contralateral ES muscles and a significant time expectation effect on RRT of contralateral MF muscles were also observed. RRT of the contralateral ES muscles was significantly lower than that of the ipsilateral ES muscles (P < 0.001). Sudden imbalance prolonged RRT of selected trunk muscles in patients with chronic LBP. The activation amplitude increased. The results may provide a theoretical basis for a study on the pathogenesis of chronic LBP.

Endothelinergic Contractile Hyperreactivity in Rat Contralateral Carotid to Balloon Injury: Integrated Role for ETB Receptors and Superoxide Anion

PubMed Central

Gimenes, Lilian R.; Gomes, Mayara S.; do Vale, Bruno N.; Cardoso, Cristina R. B.; de Oliveira, Ana M.; Moreira, Josimar D.

2017-01-01

Temporal consequences of neurocompensation to balloon injury on endothelinergic functionality in rat contralateral carotid were evaluated. Rats underwent balloon injury in left carotid and were treated with CP-96345 (NK1 antagonist). Concentration-response curves for endothelin-1 were obtained in contralateral (right) carotid at 2, 8, 16, 30, or 45 days after surgery in the absence or presence of BQ-123 (ETA antagonist), BQ-788 (ETB antagonist), or Tempol (superoxide-dismutase mimic). Endothelin-1-induced calcium mobilization was evaluated in functional assays carried out with BQ-123, BQ-788, or Tempol. Endothelin-1-induced NADPH oxidase-driven superoxide generation was measured by lucigenin chemiluminescence assays performed with BQ-123 or BQ-788. Endothelin-1-induced contraction was increased in contralateral carotid from the sixteenth day after surgery. This response was restored in CP-96345-treated rats. Endothelium removal or BQ-123 did not change endothelin-1-induced contraction in contralateral carotid. This response was restored by BQ-788 or Tempol. Contralateral carotid exhibited an increased endothelin-1-induced calcium mobilization, which was restored by BQ-788 or Tempol. Contralateral carotid exhibited an increased endothelin-1-induced lucigenin chemiluminescence, which was restored by BQ-788. We conclude that the NK1-mediated neurocompensatory response to balloon injury elicits a contractile hyperreactivity to endothelin-1 in rat contralateral carotid by enhancing the muscular ETB-mediated NADPH oxidase-driven generation of superoxide, which activates calcium channels. PMID:29062837

SOD1 overexpression prevents acute hyperglycemia-induced cerebral myogenic dysfunction: relevance to contralateral hemisphere and stroke outcomes

PubMed Central

Coucha, Maha; Li, Weiguo; Hafez, Sherif; Abdelsaid, Mohammed; Johnson, Maribeth H.; Fagan, Susan C.

2014-01-01

Admission hyperglycemia (HG) amplifies vascular injury and neurological deficits in acute ischemic stroke, but the mechanisms remain controversial. We recently reported that ischemia-reperfusion (I/R) injury impairs the myogenic response in both hemispheres via increased nitration. However, whether HG amplifies contralateral myogenic dysfunction and whether loss of tone in the contralateral hemisphere contributes to stroke outcomes remain to be determined. Our hypothesis was that contralateral myogenic dysfunction worsens stroke outcomes after acute hyperglycemic stroke in an oxidative stress-dependent manner. Male wild-type or SOD1 transgenic rats were injected with saline or 40% glucose solution 10 min before surgery and then subjected to 30 min of ischemia/45 min or 24 h of reperfusion. In another set of animals (n = 5), SOD1 was overexpressed only in the contralateral hemisphere by stereotaxic adenovirus injection 2–3 wk before I/R. Myogenic tone and neurovascular outcomes were determined. HG exacerbated myogenic dysfunction in contralateral side only, which was associated with infarct size expansion, increased edema, and more pronounced neurological deficit. Global and selective SOD1 overexpression restored myogenic reactivity in ipsilateral and contralateral sides, respectively, and enhanced neurovascular outcomes. In conclusion, our results show that SOD1 overexpression nullified the detrimental effects of HG on myogenic tone and stroke outcomes and that the contralateral hemisphere may be a novel target for the management of acute hyperglycemic stroke. PMID:25552308

Prior contralateral amputation predicts worse outcomes for lower extremity bypasses performed in the intact limb.

PubMed

Baril, Donald T; Goodney, Philip P; Robinson, William P; Nolan, Brian W; Stone, David H; Li, YouFu; Cronenwett, Jack L; Schanzer, Andres

2012-08-01

To date, history of a contralateral amputation as a potential predictor of outcomes after lower extremity bypass (LEB) for critical limb ischemia (CLI) has not been studied. We sought to determine if a prior contralateral lower extremity amputation predicts worse outcomes in patients undergoing LEB in the remaining intact limb. A retrospective analysis of all patients undergoing infrainguinal LEB for CLI between 2003 and 2010 within hospitals comprising the Vascular Study Group of New England was performed. Patients were stratified according to whether or not they had previously undergone a contralateral major or minor amputation before LEB. Primary end points included major amputation and graft occlusion at 1 year postoperatively. Secondary end points included in-hospital major adverse events, discharge status, and mortality at 1 year. Of 2636 LEB procedures, 228 (8.6%) were performed in the setting of a prior contralateral amputation. Patients with a prior amputation compared to those without were younger (66.5 vs 68.7; P = .034), more like to have congestive heart failure (CHF; 25% vs 16%; P = .002), hypertension (94% vs 85%; P = .015), renal insufficiency (26% vs 14%; P = .0002), and hemodialysis-dependent renal failure (14% vs 6%; P = .0002). They were also more likely to be nursing home residents (8.0% vs 3.6%; P = .036), less likely to ambulate without assistance (41% vs 80%; P < .0002), and more likely to have had a prior ipsilateral bypass (20% vs 12%; P = .0005). These patients experience increased in-hospital major adverse events, including myocardial infarction (MI; 8.9% vs 4.2%; P = .002), CHF (6.1% vs 3.4%; P = .044), deterioration in renal function (9.0% vs 4.7%; P = .006), and respiratory complications (4.2% vs 2.3%; P = .034). They were less likely to be discharged home (52% vs 72%; P < .0001) and less likely to be ambulatory on discharge (25% vs 55%; P < .0001). Although patients with a prior contralateral amputation experienced increased rates of graft occlusion (38% vs 17%; P < .0001) and major amputation (16% vs 7%; P < .0001) at 1 year, there was not a significant difference in mortality (16% vs 10%; P = .160). On multivariable analysis, prior contralateral amputation was an independent predictor of both major amputation (odds ratio, 1.73; confidence interval, 1.06-2.83; P = .027) and graft occlusion (odds ratio, 1.93; confidence interval, 1.39-2.68; P < .0001) at 1 year. Patients with prior contralateral amputations who present with CLI in the intact limb represent a high-risk population, even among patients with advanced peripheral arterial disease. When considering LEB in this setting, both physicians and patients should expect increased rates of perioperative adverse events, increased rates of 1-year graft occlusion, and decreased rates of limb salvage, when compared with patients who have not undergone a contralateral amputation. Copyright © 2012 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Prior contralateral amputation predicts worse outcomes for lower extremity bypasses performed in the intact limb

PubMed Central

Baril, Donald T.; Goodney, Philip P.; Robinson, William P.; Nolan, Brian W.; Stone, David H.; Li, YouFu; Cronenwett, Jack L.; Schanzer, Andres

2013-01-01

Introduction To date, history of a contralateral amputation as a potential predictor of outcomes after lower extremity bypass (LEB) for critical limb ischemia (CLI) has not been studied. We sought to determine if a prior contralateral lower extremity amputation predicts worse outcomes in patients undergoing LEB in the remaining intact limb. Methods A retrospective analysis of all patients undergoing infrainguinal LEB for CLI between 2003 and 2010 within hospitals comprising the Vascular Study Group of New England was performed. Patients were stratified according to whether or not they had previously undergone a contralateral major or minor amputation before LEB. Primary end points included major amputation and graft occlusion at 1 year postoperatively. Secondary end points included in-hospital major adverse events, discharge status, and mortality at 1 year. Results Of 2636 LEB procedures, 228 (8.6%) were performed in the setting of a prior contralateral amputation. Patients with a prior amputation compared to those without were younger (66.5 vs 68.7; P = .034), more like to have congestive heart failure (CHF; 25% vs 16%; P = .002), hypertension (94% vs 85%; P = .015), renal insufficiency (26% vs 14%; P = .0002), and hemodialysis-dependent renal failure (14% vs 6%; P = .0002). They were also more likely to be nursing home residents (8.0% vs 3.6%; P = .036), less likely to ambulate without assistance (41% vs 80%; P < .0002), and more likely to have had a prior ipsilateral bypass (20% vs 12%; P = .0005). These patients experience increased in-hospital major adverse events, including myocardial infarction (MI; 8.9% vs 4.2%; P = .002), CHF (6.1% vs 3.4%; P = .044), deterioration in renal function (9.0% vs 4.7%; P = .006), and respiratory complications (4.2% vs 2.3%; P = .034). They were less likely to be discharged home (52% vs 72%; P < .0001) and less likely to be ambulatory on discharge (25% vs 55%; P < .0001). Although patients with a prior contralateral amputation experienced increased rates of graft occlusion (38% vs 17%; P < .0001) and major amputation (16% vs 7%; P < .0001) at 1 year, there was not a significant difference in mortality (16% vs 10%; P = .160). On multivariable analysis, prior contralateral amputation was an independent predictor of both major amputation (odds ratio, 1.73; confidence interval, 1.06–2.83; P = .027) and graft occlusion (odds ratio, 1.93; confidence interval, 1.39–2.68; P < .0001) at 1 year. Conclusions Patients with prior contralateral amputations who present with CLI in the intact limb represent a high-risk population, even among patients with advanced peripheral arterial disease. When considering LEB in this setting, both physicians and patients should expect increased rates of perioperative adverse events, increased rates of 1-year graft occlusion, and decreased rates of limb salvage, when compared with patients who have not undergone a contralateral amputation. PMID:22480762

Acupuncture for lateral epicondylitis (tennis elbow): study protocol for a randomized, practitioner-assessor blinded, controlled pilot clinical trial.

PubMed

Shin, Kyung-Min; Kim, Joo-Hee; Lee, Seunghoon; Shin, Mi-Suk; Kim, Tae-Hun; Park, Hyo-Ju; Lee, Min-Hee; Hong, Kwon-Eui; Lee, Seungdeok; Choi, Sun-Mi

2013-06-14

Lateral epicondylitis is the most frequent cause of pain around the elbow joint. It causes pain in the region of the elbow joint and results in dysfunction of the elbow and deterioration of the quality of life. The purpose of this study is to compare the effects of ipsilateral acupuncture, contralateral acupuncture and sham acupuncture on lateral epicondylitis. Forty-five subjects with lateral epicondylitis will be randomized into three groups: the ipsilateral acupuncture group, contralateral acupuncture group and the sham acupuncture group. The inclusion criteria will be as follows: (1) age between 19 and 65 years with pain due to one-sided lateral epicondylitis that persisted for at least four weeks, (2) with tenderness on pressure limited to regions around the elbow joint, (3) complaining of pain during resistive extension of the middle finger or the wrist, (4) with average pain of NRS 4 or higher during the last one week at a screening visit and (5) voluntarily agree to this study and sign a written consent. Acupuncture treatment will be given 10 times in total for 4 weeks to all groups. Follow up observations will be conducted after the completion of the treatment, 8 weeks and 12 weeks after the random assignment. Ipsilateral acupuncture group and contralateral acupuncture group will receive acupuncture on LI4, TE5, LI10, LI11, LU5, LI12 and two Ashi points. The sham acupuncture group will receive treatment on acupuncture points not related to the lateral epicondylitis using a non-invasive method. The needles will be maintained for 20 minutes. The primary outcome will be differences in the visual analogue scale (VAS) for elbow pain between the groups. The secondary outcome will be differences in patient-rated tennis elbow evaluation (PRTEE), pain-free/maximum grip strength (Dynamometer), pressure pain threshold, clinically relevant improvement, patient global assessment, and the EQ-5D. The data will be analyzed with the paired t-test and ANCOVA (P <0.05). The results of this study will allow evaluation of contralateral acupuncture from two aspects. First, if the contralateral acupuncture shows the effects similar to ipsilateral acupuncture, this will establish clinical basis for contralateral acupuncture. Second, if the effects of contralateral acupuncture are not comparable to the effects of ipsilateral acupuncture, but are shown to be similar to the effects of the sham acupuncture, we can establish the basis for using the same acupoints of the unaffected side as a control in acupuncture clinical studies. This trial has been registered with the 'Clinical Research Information Service (CRIS)', Republic of Korea: KCT0000628.

Acupuncture for lateral epicondylitis (tennis elbow): study protocol for a randomized, practitioner-assessor blinded, controlled pilot clinical trial

PubMed Central

2013-01-01

Background Lateral epicondylitis is the most frequent cause of pain around the elbow joint. It causes pain in the region of the elbow joint and results in dysfunction of the elbow and deterioration of the quality of life. The purpose of this study is to compare the effects of ipsilateral acupuncture, contralateral acupuncture and sham acupuncture on lateral epicondylitis. Methods/design Forty-five subjects with lateral epicondylitis will be randomized into three groups: the ipsilateral acupuncture group, contralateral acupuncture group and the sham acupuncture group. The inclusion criteria will be as follows: (1) age between 19 and 65 years with pain due to one-sided lateral epicondylitis that persisted for at least four weeks, (2) with tenderness on pressure limited to regions around the elbow joint, (3) complaining of pain during resistive extension of the middle finger or the wrist, (4) with average pain of NRS 4 or higher during the last one week at a screening visit and (5) voluntarily agree to this study and sign a written consent. Acupuncture treatment will be given 10 times in total for 4 weeks to all groups. Follow up observations will be conducted after the completion of the treatment, 8 weeks and 12 weeks after the random assignment. Ipsilateral acupuncture group and contralateral acupuncture group will receive acupuncture on LI4, TE5, LI10, LI11, LU5, LI12 and two Ashi points. The sham acupuncture group will receive treatment on acupuncture points not related to the lateral epicondylitis using a non-invasive method. The needles will be maintained for 20 minutes. The primary outcome will be differences in the visual analogue scale (VAS) for elbow pain between the groups. The secondary outcome will be differences in patient-rated tennis elbow evaluation (PRTEE), pain-free/maximum grip strength (Dynamometer), pressure pain threshold, clinically relevant improvement, patient global assessment, and the EQ-5D. The data will be analyzed with the paired t-test and ANCOVA (P <0.05). Discussion The results of this study will allow evaluation of contralateral acupuncture from two aspects. First, if the contralateral acupuncture shows the effects similar to ipsilateral acupuncture, this will establish clinical basis for contralateral acupuncture. Second, if the effects of contralateral acupuncture are not comparable to the effects of ipsilateral acupuncture, but are shown to be similar to the effects of the sham acupuncture, we can establish the basis for using the same acupoints of the unaffected side as a control in acupuncture clinical studies. Trial registration This trial has been registered with the ‘Clinical Research Information Service (CRIS)’, Republic of Korea: KCT0000628. PMID:23768129

Ocular examination for trauma; clinical ultrasound aboard the International Space Station.

PubMed

Chiao, Leroy; Sharipov, Salizhan; Sargsyan, Ashot E; Melton, Shannon; Hamilton, Douglas R; McFarlin, Kellie; Dulchavsky, Scott A

2005-05-01

Ultrasound imaging is a successful modality in a broad variety of diagnostic applications including trauma. Ultrasound has been shown to be accurate when performed by non-radiologist physicians; recent reports have suggested that non-physicians can perform limited ultrasound examinations. A multipurpose ultrasound system is installed on the International Space Station (ISS) as a component of the Human Research Facility (HRF). This report documents the first ocular ultrasound examination conducted in space, which demonstrated the capability to assess physiologic alterations or pathology including trauma during long-duration space flight. An ISS crewmember with minimal sonography training was remotely guided by an imaging expert from Mission Control Center (MCC) through a comprehensive ultrasound examination of the eye. A multipurpose ultrasound imager was used in conjunction with a space-to-ground video downlink and two-way audio. Reference cards with topological reference points, hardware controls, and target images were used to facilitate the examination. Multiple views of the eye structures were obtained through a closed eyelid. Pupillary response to light was demonstrated by modifying the light exposure of the contralateral eye. A crewmember on the ISS was able to complete a comprehensive ocular examination using B- and M-mode ultrasonography with remote guidance from an expert in the MCC. Multiple anteroposterior, oblique, and coronal views of the eye clearly demonstrated the anatomic structures of both segments of the globe. The iris and pupil were readily visualized with probe manipulation. Pupillary diameter was assessed in real time in B- and M-mode displays. The anatomic detail and fidelity of ultrasound video were excellent and could be used to answer a variety of clinical and space physiologic questions. A comprehensive, high-quality ultrasound examination of the eye was performed with a multipurpose imager aboard the ISS by a non-expert operator using remote guidance. Ocular ultrasound images were of diagnostic quality despite the 2-second communication latency and the unconventional setting of a weightless spacecraft environment. The remote guidance techniques developed to facilitate this successful NASA research experiment will support wider applications of ultrasound for remote medicine on Earth including the assessment of pupillary reactions in patients with severe craniofacial trauma and swelling.

Ocular examination for trauma; clinical ultrasound aboard the International Space Station

NASA Technical Reports Server (NTRS)

Chiao, Leroy; Sharipov, Salizhan; Sargsyan, Ashot E.; Melton, Shannon; Hamilton, Douglas R.; McFarlin, Kellie; Dulchavsky, Scott A.

2005-01-01

BACKGROUND: Ultrasound imaging is a successful modality in a broad variety of diagnostic applications including trauma. Ultrasound has been shown to be accurate when performed by non-radiologist physicians; recent reports have suggested that non-physicians can perform limited ultrasound examinations. A multipurpose ultrasound system is installed on the International Space Station (ISS) as a component of the Human Research Facility (HRF). This report documents the first ocular ultrasound examination conducted in space, which demonstrated the capability to assess physiologic alterations or pathology including trauma during long-duration space flight. METHODS: An ISS crewmember with minimal sonography training was remotely guided by an imaging expert from Mission Control Center (MCC) through a comprehensive ultrasound examination of the eye. A multipurpose ultrasound imager was used in conjunction with a space-to-ground video downlink and two-way audio. Reference cards with topological reference points, hardware controls, and target images were used to facilitate the examination. Multiple views of the eye structures were obtained through a closed eyelid. Pupillary response to light was demonstrated by modifying the light exposure of the contralateral eye. RESULTS: A crewmember on the ISS was able to complete a comprehensive ocular examination using B- and M-mode ultrasonography with remote guidance from an expert in the MCC. Multiple anteroposterior, oblique, and coronal views of the eye clearly demonstrated the anatomic structures of both segments of the globe. The iris and pupil were readily visualized with probe manipulation. Pupillary diameter was assessed in real time in B- and M-mode displays. The anatomic detail and fidelity of ultrasound video were excellent and could be used to answer a variety of clinical and space physiologic questions. CONCLUSIONS: A comprehensive, high-quality ultrasound examination of the eye was performed with a multipurpose imager aboard the ISS by a non-expert operator using remote guidance. Ocular ultrasound images were of diagnostic quality despite the 2-second communication latency and the unconventional setting of a weightless spacecraft environment. The remote guidance techniques developed to facilitate this successful NASA research experiment will support wider applications of ultrasound for remote medicine on Earth including the assessment of pupillary reactions in patients with severe craniofacial trauma and swelling.

Photoreceptor protection by adeno-associated virus-mediated LEDGF expression in the RCS rat model of retinal degeneration: probing the mechanism.

PubMed

Raz-Prag, Dorit; Zeng, Yong; Sieving, Paul A; Bush, Ronald A

2009-08-01

Lens epithelium-derived growth factor (LEDGF) is upregulated in response to stress and enhances the survival of neurons in the retina and optic nerve, as well as a wide range of other cells, such as fibroblasts and keratinocytes. Photoreceptor protection was investigated in the RCS rat retinal degeneration model after Ledgf delivery with an adeno-associated virus (AAV) and the mechanism of protection explored. Thirty-six RCS and nine P23H rats had bilateral subretinal injections of AAV-Ledgf in one eye and buffer in the contralateral eye as the control. Retinal function was evaluated 8 weeks later by the electroretinogram and compared with photoreceptor cell layer count. LEDGF mRNA and protein levels and mRNA levels of known stress-related factors were compared in treated and control retinas to explore the mechanism of LEDGF protection. Nine RCS rats were treated with adenovirus-heat shock protein 27 (Ad-HSP27) and examined for protection. Significant photoreceptor protection was evident functionally and morphologically in 65% to 100% of the RCS rats treated at early ages of up to 7 weeks. Cell protection was more prominent in the superior retinal hemisphere which has a slower natural degeneration rate in untreated eyes. Although many of the heat shock proteins and other stress-related genes showed significant elevation in the AAV-Ledgf-treated eyes, all increases were approximately twofold or less. Transduction of retinal cells with Ad-HSP27 also resulted in photoreceptor protection. AAV-Ledgf elicited no photoreceptor functional protection in P23H rhodopsin transgenic rat retina. Chronic LEDGF treatment via AAV-Ledgf administration gave successful protection of photoreceptors in the RCS rat retina and retarded cell death by about 2 weeks. Induction of heat shock proteins also gave photoreceptor protection. However, compelling evidence was not found that LEDGF protection was associated with upregulation of heat shock proteins.

Monaural and binaural contributions to interaural-level-difference sensitivity in human auditory cortex.

PubMed

Stecker, G Christopher; McLaughlin, Susan A; Higgins, Nathan C

2015-10-15

Whole-brain functional magnetic resonance imaging was used to measure blood-oxygenation-level-dependent (BOLD) responses in human auditory cortex (AC) to sounds with intensity varying independently in the left and right ears. Echoplanar images were acquired at 3 Tesla with sparse image acquisition once per 12-second block of sound stimulation. Combinations of binaural intensity and stimulus presentation rate were varied between blocks, and selected to allow measurement of response-intensity functions in three configurations: monaural 55-85 dB SPL, binaural 55-85 dB SPL with intensity equal in both ears, and binaural with average binaural level of 70 dB SPL and interaural level differences (ILD) ranging ±30 dB (i.e., favoring the left or right ear). Comparison of response functions equated for contralateral intensity revealed that BOLD-response magnitudes (1) generally increased with contralateral intensity, consistent with positive drive of the BOLD response by the contralateral ear, (2) were larger for contralateral monaural stimulation than for binaural stimulation, consistent with negative effects (e.g., inhibition) of ipsilateral input, which were strongest in the left hemisphere, and (3) also increased with ipsilateral intensity when contralateral input was weak, consistent with additional, positive, effects of ipsilateral stimulation. Hemispheric asymmetries in the spatial extent and overall magnitude of BOLD responses were generally consistent with previous studies demonstrating greater bilaterality of responses in the right hemisphere and stricter contralaterality in the left hemisphere. Finally, comparison of responses to fast (40/s) and slow (5/s) stimulus presentation rates revealed significant rate-dependent adaptation of the BOLD response that varied across ILD values. Copyright © 2015. Published by Elsevier Inc.

PubMed Central

SENNAROĞLU, G.; YÜCEL, E.; BELGIN, E.; MANCINI, P.

2015-01-01

SUMMARY The aim of this study was to investigate the amount of binaural squelch effect (BSE) and head shadow effect (HSE) in children who use unilateral cochlear implants (CI) and contralateral hearing aids (HA). The study group consisted of 19 CI recipient children who consistently wore a contralateral HA. Speech sounds were used to evaluate speech perception performance in noise. Testing was performed in three listening conditions: (1) bimodal listening with noise source on HA side; (2) CI only with noise source contralaterally (HA off); (3) CI only with noise source on the CI side. Statistical analysis revealed a significant difference between the three listening conditions and post hoc tests indicated significant differences for all pairwise comparisons (p < 0.001). The average BSE and HSE were 11.8% and 17.1% respectively. The majority of bimodal CI users showed BSE and HSE with significant speech perception improvement in the presence of noise. PMID:26824917

Cervical sympathetic block prolongs the latency and reduces the amplitude of trigeminal somatosensory evoked potentials on the contralateral side.

PubMed

Kawaguchi, Jun; Matsuura, Nobuyuki; Kasahara, Masataka; Ichinohe, Tatsuya

2015-02-01

The purpose of this study was to investigate the latency and amplitude of trigeminal somatosensory evoked potentials to clarify how nerve function on the contralateral side is affected after cervical sympathetic block (CSB). Subjects comprised 16 volunteers. For CSB, the tip of a needle was contacted with the transverse process of the sixth cervical vertebra on the right side, and lidocaine was injected. Trigeminal somatosensory evoked potentials were recorded bilaterally from C5/C6 scalp positions. Pupil diameters were also measured. Electrical stimulations were applied to the left-side lower lip, and trigeminal somatosensory evoked potentials waveforms derived from both sides of the scalp were recorded. Then, electrical stimulations were applied to the right-side of the lower lip, and recording was again performed. Recordings were performed at 5, 15, and 30 minutes after CSB. On the CSB side, pupil diameter decreased at 5 and 15 minutes after CSB. Trigeminal somatosensory evoked potentials at contralateral stimulation showed a prolongation of the latency in both P20 and N25 components on bilateral recording sites 5 and 15 minutes after CSB. Trigeminal somatosensory evoked potentials' amplitude at contralateral stimulation was smaller than at ipsilateral stimulation 5 minutes after CSB. Cervical sympathetic block prolongs the latency and reduces the amplitude of trigeminal somatosensory evoked potentials on the contralateral side.

Improvement in Cerebral and Ocular Hemodynamics Early after Carotid Endarterectomy in Patients of Severe Carotid Artery Stenosis with or without Contralateral Carotid Occlusion.

PubMed

Wang, Jian; Wang, Weici; Jin, Bi; Zhang, Yanrong; Xu, Ping; Xiang, Feixiang; Zheng, Yi; Chen, Juan; Sheng, Shi; Ouyang, Chenxi; Li, Yiqing

2016-01-01

Purpose. To investigate the alternation in cerebral and ocular blood flow velocity (BFV) in patients of carotid stenosis (CS) with or without contralateral carotid occlusion (CO) early after carotid endarterectomy (CEA). Patients and Methods. Nineteen patients underwent CEA for ≥50% CS. Fourteen patients had the unilateral CS, and five patients had the ipsilateral CS and the contralateral CO. Transcranial Doppler (TCD) and Color Doppler Imaging (CDI) were performed before and early after CEA. Results. In patients with unilateral CS, significant improvements in BFV were observed in anterior cerebral artery (ACA) and middle cerebral artery (MCA) on the ipsilateral side after CEA. In patients of ipsilateral CS and contralateral CO, significant improvements in BFV were observed in the ACA and MCA not only on the ipsilateral side but also on the contralateral side postoperatively. The ipsilateral ophthalmic artery (OA) retrograde flows in two patients were recovered to anterograde direction following CEA. The BFV in short posterior ciliary artery (SPCA) of the ipsilateral side significantly increased postoperatively irrespective of the presence of contralateral CO. Conclusions. CEA improved cerebral anterior circulation hemodynamics especially in patients of unilateral CS and contralateral CO, normalized the OA reverse flow, and increased the blood perfusion of SPCA.

Granger causal time-dependent source connectivity in the somatosensory network

NASA Astrophysics Data System (ADS)

Gao, Lin; Sommerlade, Linda; Coffman, Brian; Zhang, Tongsheng; Stephen, Julia M.; Li, Dichen; Wang, Jue; Grebogi, Celso; Schelter, Bjoern

2015-05-01

Exploration of transient Granger causal interactions in neural sources of electrophysiological activities provides deeper insights into brain information processing mechanisms. However, the underlying neural patterns are confounded by time-dependent dynamics, non-stationarity and observational noise contamination. Here we investigate transient Granger causal interactions using source time-series of somatosensory evoked magnetoencephalographic (MEG) elicited by air puff stimulation of right index finger and recorded using 306-channel MEG from 21 healthy subjects. A new time-varying connectivity approach, combining renormalised partial directed coherence with state space modelling, is employed to estimate fast changing information flow among the sources. Source analysis confirmed that somatosensory evoked MEG was mainly generated from the contralateral primary somatosensory cortex (SI) and bilateral secondary somatosensory cortices (SII). Transient Granger causality shows a serial processing of somatosensory information, 1) from contralateral SI to contralateral SII, 2) from contralateral SI to ipsilateral SII, 3) from contralateral SII to contralateral SI, and 4) from contralateral SII to ipsilateral SII. These results are consistent with established anatomical connectivity between somatosensory regions and previous source modeling results, thereby providing empirical validation of the time-varying connectivity analysis. We argue that the suggested approach provides novel information regarding transient cortical dynamic connectivity, which previous approaches could not assess.

Contralateral Dpoae Suppression in Humans at Very Low Sound Intensities

NASA Astrophysics Data System (ADS)

Janssen, T.; Gehr, D. D.; Kevanishvili, Z.

2003-02-01

Different functions are attributed to the olivo-cochlear bundle system (OCBS) such as protecting the ear from acoustic injury, improving signal detection in noise, and mediating selective attention. OCBS reflex strength can be evaluated, in animals as well as in humans, by measuring the degree of suppression of an ipsilateral DPOAE by a contralateral sound. The purpose of the study was to evaluate OCBS reflex strength depending on ipsilateral stimulus level, especially at threshold, by means of extrapolated DPOAE I/O-functions. Additionally, DPOAE was measured at near-to-threshold contralateral stimulus levels when using low-level ipsilateral stimulation for investigating possible enhancement of outer hair cell motion in the presence of low-level contralateral sound. The recording of the 2f1-f2 DPOAE in the presence or absence of contralateral sound was performed in normally hearing human subjects at f2 = 2 kHz. DPOAE I/O-functions were measured in a primary tone level range from L2 = 20 to L2 = 65 dB SPL (L1 = 0.4L2 + 39, f2/f1=1.2). Broad-band noise (BBN), narrow-band noise from 1720 to 2320 Hz (NBN), and pure tones (PT) at f2, 2f1-f2, geometric mean of f1 and f2, and 0.1oct + f2 were used for contralateral stimulation. The contralateral stimulus level (Ls) was decreased from 70 down to 10 dB SPL in 10 dB steps. DPOAE suppression was highest at the lowest primary tone level and was more pronounced for BBN and NBN than for pure tones, suggesting a more diffuse than a strong tonotopic organisation of the OCBS. The contralateral stimulus level at which significant DPOAE suppression occurred (p < 0.05) was different for the different stimuli being 20, 40, and 70 dB SPL for BBN, NBN, and pure-tone (f2), respectively. Significant DPOAE suppression to BBN and NBN occurred at Ls well below audiological middle-ear reflex threshold. DPOAE time course was different for Ls below and above middle-ear reflex threshold. Thus, middle-ear muscle contraction is suggested not to be involved in DPOAE suppression at low Ls. No enhancement of DPOAE could be found. The findings suggest the OCBS to be functioning in a more protective way than for improving signal detection in noise.

Polyamines in the lateral vestibular nuclei of the squirrel monkey and their potential role in vestibular compensation

NASA Technical Reports Server (NTRS)

Henley, C.; Igarashi, M.

1993-01-01

Polyamine synthesis increases in response to injurious stimuli including axotomy and denervation. Reduced eye nystagmus and head-deviation have been observed in unilateral labyrinthectomized (UL) guinea pigs treated with an inhibitor of polyamine synthesis, alpha-difluoromethylornithine (DFMO). We quantified polyamines in the lateral vestibular nuclei (LVN) of control and UL squirrel monkeys during the phase of vestibular compensation (VC) and performed an experiment to determine if DFMO reduces nystagmus previously observed in the guinea pig. Polyamines were detected in the LVN of control and UL squirrel monkeys. Putrescine and spermidine increased in the ipsilateral LVN 3 days after UL with no change in the contralateral LVN. No left-right differences were noted in the 5-day post-UL monkey. DFMO reduced nystagmus in a UL squirrel monkey. These findings suggest that polyamines are important in vestibular function and may contribute to nystagmus observed in VC.

Hyperventilation-induced nystagmus in vestibular schwannoma and unilateral sensorineural hearing loss.

PubMed

Mandalà, Marco; Giannuzzi, Annalisa; Astore, Serena; Trabalzini, Franco; Nuti, Daniele

2013-07-01

We evaluated the incidence and characteristics of hyperventilation-induced nystagmus (HVN) in 49 patients with gadolinium-enhanced magnetic resonance imaging evidence of vestibular schwannoma and 53 patients with idiopathic unilateral sensorineural hearing loss and normal radiological findings. The sensitivity and specificity of the hyperventilation test were compared with other audio-vestibular diagnostic tests (bedside examination of eye movements, caloric test, auditory brainstem responses) in the two groups of patients. The hyperventilation test scored the highest diagnostic efficiency (sensitivity 65.3 %; specificity 98.1 %) of the four tests in the differential diagnosis of vestibular schwannoma and idiopathic unilateral sensorineural hearing loss. Small tumors with a normal caloric response or caloric paresis were associated with ipsilateral HVN and larger tumors and severe caloric deficits with contralateral HVN. These results confirm that the hyperventilation test is a useful diagnostic test for predicting vestibular schwannoma in patients with unilateral sensorineural hearing loss.

Diversity of bilateral synaptic assemblies for binaural computation in midbrain single neurons.

PubMed

He, Na; Kong, Lingzhi; Lin, Tao; Wang, Shaohui; Liu, Xiuping; Qi, Jiyao; Yan, Jun

2017-11-01

Binaural hearing confers many beneficial functions but our understanding of its underlying neural substrates is limited. This study examines the bilateral synaptic assemblies and binaural computation (or integration) in the central nucleus of the inferior colliculus (ICc) of the auditory midbrain, a key convergent center. Using in-vivo whole-cell patch-clamp, the excitatory and inhibitory postsynaptic potentials (EPSPs/IPSPs) of single ICc neurons to contralateral, ipsilateral and bilateral stimulation were recorded. According to the contralateral and ipsilateral EPSP/IPSP, 7 types of bilateral synaptic assemblies were identified. These include EPSP-EPSP (EE), E-IPSP (EI), E-no response (EO), II, IE, IO and complex-mode (CM) neurons. The CM neurons showed frequency- and/or amplitude-dependent EPSPs/IPSPs to contralateral or ipsilateral stimulation. Bilateral stimulation induced EPSPs/IPSPs that could be larger than (facilitation), similar to (ineffectiveness) or smaller than (suppression) those induced by contralateral stimulation. Our findings have allowed our group to characterize novel neural circuitry for binaural computation in the midbrain. Copyright © 2017 Elsevier B.V. All rights reserved.

Can the contralateral limb be used as a control during the growing period in a rodent model?

PubMed

Mustafy, Tanvir; Londono, Irène; Villemure, Isabelle

2018-05-12

The contralateral limb is often used as a control in various clinical, forensic and anthropological studies. However, no studies have been performed to determine if the contra-lateral limb is a suitable control during the bone development period. The aim of this study was to determine the bilateral symmetry of growing rat tibiae in terms of geometric shape, mechanical strength and bone morphological parameters with developmental stages. Left and right tibias of 18 male Sprague-Dawley rats at 4, 8 and 12 weeks of age were scanned with micro-CT for bone-morphometric evaluation and for 3D deviation analysis to quantify the geometric shape variations between left and right tibiae. Overall tibial lengths and curvatures were also measured, and bone mechanical strength was investigated using three-point bending tests. Deviation distributions between bilateral tibiae remained below 0.5 mm for more than 80% of the geometry for all groups. Tibial lengths, longitudinal tibial curvatures, bone-morphometric parameters and mechanical strengths changed significantly during the growing period but kept a strong degree of symmetry between bilateral tibiae. These results suggest that bilateral tibiae can be considered symmetrical in nature and that contralateral limb can be used as a control during the growing period in different experimental scenarios. Copyright © 2018 Elsevier Ltd. All rights reserved.

Asymmetry Analysis of Macular Inner Retinal Layers for Glaucoma Diagnosis: Swept-Source Optical Coherence Tomography Study.

PubMed

Lee, Sang-Yoon; Lee, Eun Kyoung; Park, Ki Ho; Kim, Dong Myung; Jeoung, Jin Wook

2016-01-01

To report an asymmetry analysis of macular inner retinal layers using swept-source optical coherence tomography (OCT) and to evaluate the utility for glaucoma diagnosis. Observational, cross-sectional study. Seventy normal healthy subjects and 62 glaucoma patients. Three-dimensional scans were acquired from 70 normal subjects and 62 open angle glaucoma patients by swept-source OCT. The thickness of the retinal nerve fiber layer, ganglion cell-inner plexiform layer (GCIPL), ganglion cell complex, and total retina were calculated within a 6.2×6.2 mm macular area divided into a 31×31 grid of 200×200 μm superpixels. For each of the corresponding superpixels, the thickness differences between the subject eyes and contra-lateral eyes and between the upper and lower macula halves of the subject eyes were determined. The negative differences were displayed on a gray-scale asymmetry map. Black superpixels were defined as thickness decreases over the cut-off values. The negative inter-ocular and inter-hemisphere differences in GCIPL thickness (mean ± standard deviation) were -2.78 ± 0.97 μm and -3.43 ± 0.71 μm in the normal group and -4.26 ± 2.23 μm and -4.88 ± 1.46 μm in the glaucoma group. The overall extent of the four layers' thickness decrease was larger in the glaucoma group than in the normal group (all Ps<0.05). The numbers of black superpixels on all of the asymmetry maps were larger in the glaucoma group than in the normal group (all Ps<0.05). The area under receiver operating characteristic curves of average negative thickness differences in macular inner layers for glaucoma diagnosis ranged from 0.748 to 0.894. The asymmetry analysis of macular inner retinal layers showed significant differences between the normal and glaucoma groups. The diagnostic performance of the asymmetry analysis was comparable to that of previous methods. These findings suggest that the asymmetry analysis can be a potential ancillary diagnostic tool.

Asymmetry Analysis of Macular Inner Retinal Layers for Glaucoma Diagnosis: Swept-Source Optical Coherence Tomography Study

PubMed Central

Lee, Sang-Yoon; Lee, Eun Kyoung; Park, Ki Ho; Kim, Dong Myung

2016-01-01

Purpose To report an asymmetry analysis of macular inner retinal layers using swept-source optical coherence tomography (OCT) and to evaluate the utility for glaucoma diagnosis. Design Observational, cross-sectional study. Participants Seventy normal healthy subjects and 62 glaucoma patients. Methods Three-dimensional scans were acquired from 70 normal subjects and 62 open angle glaucoma patients by swept-source OCT. The thickness of the retinal nerve fiber layer, ganglion cell-inner plexiform layer (GCIPL), ganglion cell complex, and total retina were calculated within a 6.2×6.2 mm macular area divided into a 31×31 grid of 200×200 μm superpixels. For each of the corresponding superpixels, the thickness differences between the subject eyes and contra-lateral eyes and between the upper and lower macula halves of the subject eyes were determined. The negative differences were displayed on a gray-scale asymmetry map. Black superpixels were defined as thickness decreases over the cut-off values. Results The negative inter-ocular and inter-hemisphere differences in GCIPL thickness (mean ± standard deviation) were -2.78 ± 0.97 μm and -3.43 ± 0.71 μm in the normal group and -4.26 ± 2.23 μm and -4.88 ± 1.46 μm in the glaucoma group. The overall extent of the four layers’ thickness decrease was larger in the glaucoma group than in the normal group (all Ps<0.05). The numbers of black superpixels on all of the asymmetry maps were larger in the glaucoma group than in the normal group (all Ps<0.05). The area under receiver operating characteristic curves of average negative thickness differences in macular inner layers for glaucoma diagnosis ranged from 0.748 to 0.894. Conclusions The asymmetry analysis of macular inner retinal layers showed significant differences between the normal and glaucoma groups. The diagnostic performance of the asymmetry analysis was comparable to that of previous methods. These findings suggest that the asymmetry analysis can be a potential ancillary diagnostic tool. PMID:27764166

Ovum transmigration after salpingectomy for ectopic pregnancy.

PubMed

Ross, Jackie A; Davison, Amelia Z; Sana, Yasmin; Appiah, Adjoa; Johns, Jemma; Lee, Christopher T

2013-04-01

What proportion of pregnancies are a result of ovum transmigration after salpingectomy for ectopic pregnancy? Approximately one-third of spontaneously conceived pregnancies are a result of pick-up of the ovum from the ovary contralateral to the remaining tube in women with a history of salpingectomy. The corpus luteum has been found contralateral to tubal ectopic pregnancies in 32% of reported cases. The rate of contralateral ovum pick-up in intrauterine pregnancies is not known. We conducted a retrospective cohort study of clinical and ultrasound records collected over a 12-year period 1999-2010. Ten per cent of cases identified were excluded from the final analysis due to incomplete data or bilateral corpora lutea. Included were 842 pregnancies in 707 women with a history of unilateral salpingectomy for ectopic pregnancy and subsequent spontaneous pregnancy. The study was set in the Early Pregnancy Unit of a large UK inner city teaching hospital. The outcome measure was the side of the corpus luteum in relation to the side of the remaining tube. The corpus luteum was located in the ovary contralateral to the remaining tube in 266/842 pregnancies (31.6%; 95% CI 28.5-34.8%). There was no significant difference in this proportion between intrauterine and ectopic pregnancies [246/769 (32.0%) versus 21/73 (28.8%), P = 0.60]. This was a retrospective study and so did not address the conception rate according to the laterality of ovulation. Our findings were very similar to the frequency of ectopic pregnancies found contralateral to the corpus luteum described in previous studies. Ovum pick-up from the cul-de-sac probably occurs reasonably frequently and is unlikely to have a causative role in the pathogenesis of ectopic pregnancy. It is not known how often this phenomenon occurs in women with intact Fallopian tubes. No specific funding was obtained. The authors have no conflicts of interest to declare.

Properties of vestibular neurones projecting to neck segments of the cat spinal cord*

PubMed Central

Rapoport, S.; Susswein, A.; Uchino, Y.; Wilson, V. J.

1977-01-01

1. Vestibular neurones projecting to the upper cervical grey matter (vestibulocollic neurones) were identified by localized microstimulation in the C3 segment of the cat spinal cord. 2. The neurones were found in the lateral (Deiters'), medial and descending nuclei bilaterally and projected to the spinal cord in the lateral and medial vestibulospinal tracts (LVST and MVST). Ipsilateral axons of Deiters' neurones were mostly in the LVST, axons of medial and descending neurones in the MVST; a few Deiters' neurones had axons in the MVST; some descending neurones had axons in the LVST. Most axons of contralateral neurones were in the MVST. 3. The axons of 62% of ipsilateral vestibulocollic Deiters' neurones not only gave off a collateral to C3, but also extended as far as the cervical enlargement (`branching'); some of these neurones projected as far as the upper thoracic cord, almost none to the lumbar cord. Ipsilateral descending nucleus neurones branch in the same fashion, but there is no branching in the relatively small medial nucleus population. 4. A large majority of vestibulocollic neurones receive monosynaptic excitation from the ipsilateral labyrinth and a number are inhibited by stimulation of the contralateral labyrinth (commissural inhibition). It is possible that commissural inhibition acts on a broad population of vestibular neurones involved in the control of eye, head and trunk movement. 5. Vestibulocollic neurones do not make up a homogeneous population acting only on the neck. Instead it is likely that subpopulations, for example branching and non-branching neurones, have different functions. PMID:874918

Risk of cataract in persons with cytomegalovirus retinitis and the acquired immune deficiency syndrome.

PubMed

Kempen, John H; Sugar, Elizabeth A; Lyon, Alice T; Lewis, Richard Alan; Jabs, Douglas A; Heinemann, Murk-Hein; Dunn, James P

2012-11-01

To evaluate cataract risk in eyes of patients with AIDS and cytomegalovirus (CMV) retinitis and to identify risk factors. Prospective cohort study. Patients with AIDS and CMV retinitis. Patients 13 years of age and older were enrolled between 1998 and 2008. Demographic and clinical characteristics, slit-lamp biomicroscopy findings, and dilated ophthalmoscopy results were documented at quarterly visits. Cataract status was determined at the initial visit (prevalence) and at follow-up visits (incidence). For cataract, a high grade of lens opacity by biomicroscopy to which best-corrected visual acuity worse than 20/40 was attributed. Eyes that had undergone cataract surgery before enrollment or between visits also were counted as having cataract. Seven hundred twenty-nine eyes of 489 patients diagnosed with CMV retinitis were evaluated. Higher prevalence was observed for patients with bilateral versus unilateral CMV retinitis (adjusted odds ratio [aOR], 2.74; 95% confidence interval [CI], 1.76-4.26) and, among unilateral CMV retinitis cases, for eyes with retinitis versus without retinitis (15% vs. 1.4%; P<0.0001). The age-adjusted prevalence of cataract among CMV retinitis cases was higher than that in a population-based sample (P<0.0001). Cataract prevalence increased with age (aOR, 11.77; 95% CI, 2.28-60.65 for age ≥ 60 years vs. younger than 40 years) and longer duration of retinitis (aOR, 1.36; 95% CI, 1.20-1.54 per year). Among eyes with CMV retinitis initially free of cataract, the cataract incidence was 8.1%/eye-year (95% CI, 6.7%-10.0%). Prior retinal detachment was associated with higher cataract risk (if repaired with silicone oil: adjusted hazard ratio [aHR], 10.37; 95% CI, 6.51-16.52; otherwise: aHR, 2.90; 95% CI, 1.73-4.87). Large CMV retinitis lesions also were associated with higher risk of cataract (for involvement of 25-49% retinal area: aHR, 2.30; 95% CI, 1.51-3.50; for ≥ 50% involvement: aHR, 3.63; 95% CI, 2.18-6.04), each with respect to ≤ 24% involvement, as were anterior segment inflammation (aHR, 2.27; 95% CI, 1.59-3.25) and contralateral cataract (aHR, 2.52; 95% CI, 1.74-3.66). Cytomegalovirus retinitis is associated with a high absolute and relative risk of cataract. Among several risk factors, large retinal lesion size and use of silicone oil in retinal detachment repair are potentially modifiable, albeit not in all cases. Cataract is likely to be an increasingly important cause of visual morbidity in this population. Copyright © 2012 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Risk of Cataract in Persons with Cytomegalovirus Retinitis and the Acquired Immune Deficiency Syndrome

PubMed Central

Kempen, John H.; Sugar, Elizabeth A.; Lyon, Alice T.; Lewis, Richard Alan; Jabs, Douglas A.; Heinemann, Murk-Hein; Dunn, James P.

2012-01-01

Objective To evaluate cataract risk in eyes of patients with AIDS and cytomegalovirus (CMV) retinitis and to identify risk factors. Design Prospective cohort study. Participants Patients with AIDS and CMV retinitis. Methods Patients 13 years of age and older were enrolled between 1998 and 2008. Demographic and clinical characteristics, slit-lamp biomicroscopy findings, and dilated ophthalmoscopy results were documented at quarterly visits. Cataract status was determined at the initial visit (prevalence) and at follow-up visits (incidence). Main Outcome Measures For cataract, a high grade of lens opacity by biomicroscopy to which best-corrected visual acuity worse than 20/40 was attributed. Eyes that had undergone cataract surgery before enrollment or between visits also were counted as having cataract. Results Seven hundred twenty-nine eyes of 489 patients diagnosed with CMV retinitis were evaluated. Higher prevalence was observed for patients with bilateral versus unilateral CMV retinitis (adjusted odds ratio [aOR], 2.74; 95% confidence interval [CI], 1.76–4.26) and, among unilateral CMV retinitis cases, for eyes with retinitis versus without retinitis (15% vs. 1.4%; P<0.0001). The age-adjusted prevalence of cataract among CMV retinitis cases was higher than that in a population-based sample (P<0.0001). Cataract prevalence increased with age (aOR, 11.77; 95% CI, 2.28–60.65 for age ≥60 years vs. younger than 40 years) and longer duration of retinitis (aOR, 1.36; 95% CI, 1.20–1.54 per year). Among eyes with CMV retinitis initially free of cataract, the cataract incidence was 8.1%/eye-year (95% CI, 6.7%–10.0%). Prior retinal detachment was associated with higher cataract risk (if repaired with silicone oil: adjusted hazard ratio [aHR], 10.37; 95% CI, 6.51–16.52; otherwise: aHR, 2.90; 95% CI, 1.73–4.87). Large CMV retinitis lesions also were associated with higher risk of cataract (for involvement of 25–49% retinal area: aHR, 2.30; 95% CI, 1.51–3.50; for ≥50% involvement: aHR, 3.63; 95% CI, 2.18–6.04), each with respect to ≤24% involvement, as were anterior segment inflammation (aHR, 2.27; 95% CI, 1.59–3.25) and contralateral cataract (aHR, 2.52; 95% CI, 1.74–3.66). Conclusions Cytomegalovirus retinitis is associated with a high absolute and relative risk of cataract. Among several risk factors, large retinal lesion size and use of silicone oil in retinal detachment repair are potentially modifiable, albeit not in all cases. Cataract is likely to be an increasingly important cause of visual morbidity in this population. PMID:22853972

The effect of prazosin on skin microcirculation as assessed by laser Doppler flowmetry.

PubMed Central

Khan, F; Struthers, A D; Spence, V A

1988-01-01

1. Laser Doppler flowmetry was used in six normal volunteers to record changes in fingertip skin blood flow after the administration of prazosin to block postsynaptic alpha 1-adrenoceptors. 2. Prazosin (0.5 mg orally) did not alter systolic or diastolic blood pressure or heart rate. 3. Prazosin did significantly increase basal skin blood flow 2 h after its administration but this effect was no longer evident after contralateral hand warming. Prazosin markedly reduced the skin vasoconstrictor response to deep inspiration and to contralateral hand cooling. 4. This study suggests that postsynaptic alpha 1-adrenoceptors are involved in maintaining skin vasoconstrictor tone at rest and are also involved in the rapid skin vasoconstriction seen in response to a deep inspiration and to contralateral hand cooling. PMID:2846022

Different functional reorganization of motor cortex after transfer of the contralateral C7 to different recipient nerves in young rats with total brachial plexus root avulsion.

PubMed

Pan, Feng; Wei, Hai-feng; Chen, Liang; Gu, Yu-dong

2012-12-07

Clinically, contralateral C7 transfer is used for nerve reconstruction in brachial plexus injuries. Postoperatively, synchronous motions at the donor limb are noteworthy. This study studied if different recipient nerves influenced transhemispheric functional reorganization of motor cortex after this procedure. 90 young rats with total root avulsion of the brachial plexus were divided into groups 1-3 of contralateral C7 transfer to anterior division of the upper trunk, to both the musculocutaneous and median nerves, and to the median nerve, respectively. After reinnervation of target muscles, number of sites for forelimb representations in bilateral motor cortices was determined by intracortical microstimulation at 1.5, 3, 6, 9, and 12 months postoperatively. At nine months, transhemispheric reorganization of nerves neurotized by contralateral C7 was fulfilled in four of six rats in group 1, one of six in group 2 and none in group 3, respectively; at 12 months, that was fulfilled in five of six in group 1, four of six in groups 2 and 3, respectively. Logistic regression analysis showed that rate of fulfilled transhemispheric reorganization in group 1 was 12.19 times that in group 3 (95% CI 0.006-0.651, p=0.032). At 12 months, number of sites for hindlimb representations which had encroached upon original forelimb representations on the uninjured side was statistically more in group 3 than in group 2 (t=9.5, p<0.0001). It is concluded that contralateral C7 transfer to upper trunk or to both the musculocutaneous and median nerves induces faster transhemispheric functional reorganization of motor cortex than that to median nerve alone in rats. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Adaptation of muscles of the lumbar spine to sudden imbalance in patients with lower back pain caused by military training

PubMed Central

Gao, Ying; Shi, Jian-guo; Ye, Hong; Liu, Zhi-rong; Zheng, Long-bao; Ni, Zhi-ming; Fan, Liang-quan; Wang, Jian; Hou, Zhen-hai

2014-01-01

Objective This study aims to investigate the effects of sudden load changes (expected and unexpected imbalance) on the activity of muscles of the lumbar spine and their central motor control strategy in military personnel with or without chronic low back pain (LBP). Design Bilateral sudden imbalance was examined (2 × 2 factorial design). Setting The 117th PLA Hospital, Hangzhou, China Participants Twenty-one male subjects with lower back pain and 21 male healthy control subjects were active members of the Nanjing Military Region land forces. Outcome measures Independent variables: LBP vs. healthy controls and imbalance anticipation (expected and unexpected imbalance). Dependent variables: rapid reaction time (RRT) and intensity of rapid reaction (IRR) of bilateral lumbar (L3–L4) erector spinae (ES), lumbar (L5–S1) multifidus (MF), and abdominal external oblique muscles. Results Under expected or unexpected sudden imbalance conditions, subjects with LBP demonstrated significantly greater IRR than healthy controls in ipsilateral and contralateral ES and MF, respectively (P < 0.05 for all). IRR of contralateral ES was significantly larger than that of the ipsilateral ES. A significant group effect of RRT of both ipsilateral and contralateral ES muscles and a significant time expectation effect on RRT of contralateral MF muscles were also observed. RRT of the contralateral ES muscles was significantly lower than that of the ipsilateral ES muscles (P < 0.001). Conclusions Sudden imbalance prolonged RRT of selected trunk muscles in patients with chronic LBP. The activation amplitude increased. The results may provide a theoretical basis for a study on the pathogenesis of chronic LBP. PMID:24621023

GABA-mediated changes in inter-hemispheric beta frequency activity in early-stage Parkinson’s disease

PubMed Central

Hall, S.D.; Prokic, E.J.; McAllister, C.J.; Ronnqvist, K.C.; Williams, A.C.; Yamawaki, N.; Witton, C.; Woodhall, G.L.; Stanford, I.M.

2014-01-01

In Parkinson’s disease (PD), elevated beta (15–35 Hz) power in subcortical motor networks is widely believed to promote aspects of PD symptomatology, moreover, a reduction in beta power and coherence accompanies symptomatic improvement following effective treatment with l-DOPA. Previous studies have reported symptomatic improvements that correlate with changes in cortical network activity following GABAA receptor modulation. In this study we have used whole-head magnetoencephalography to characterize neuronal network activity, at rest and during visually cued finger abductions, in unilaterally symptomatic PD and age-matched control participants. Recordings were then repeated following administration of sub-sedative doses of the hypnotic drug zolpidem (0.05 mg/kg), which binds to the benzodiazepine site of the GABAA receptor. A beamforming based ‘virtual electrode’ approach was used to reconstruct oscillatory power in the primary motor cortex (M1), contralateral and ipsilateral to symptom presentation in PD patients or dominant hand in control participants. In PD patients, contralateral M1 showed significantly greater beta power than ipsilateral M1. Following zolpidem administration contralateral beta power was significantly reduced while ipsilateral beta power was significantly increased resulting in a hemispheric power ratio that approached parity. Furthermore, there was highly significant correlation between hemispheric beta power ratio and Unified Parkinson’s Disease Rating Scale (UPDRS). The changes in contralateral and ipsilateral beta power were reflected in pre-movement beta desynchronization and the late post-movement beta rebound. However, the absolute level of movement-related beta desynchronization was not altered. These results show that low-dose zolpidem not only reduces contralateral beta but also increases ipsilateral beta, while rebalancing the dynamic range of M1 network oscillations between the two hemispheres. These changes appear to underlie the symptomatic improvements afforded by low-dose zolpidem. PMID:25261686

Examination of Poststroke Alteration in Motor Unit Firing Behavior Using High-Density Surface EMG Decomposition.

PubMed

Li, Xiaoyan; Holobar, Ales; Gazzoni, Marco; Merletti, Roberto; Rymer, William Zev; Zhou, Ping

2015-05-01

Recent advances in high-density surface electromyogram (EMG) decomposition have made it a feasible task to discriminate single motor unit activity from surface EMG interference patterns, thus providing a noninvasive approach for examination of motor unit control properties. In the current study, we applied high-density surface EMG recording and decomposition techniques to assess motor unit firing behavior alterations poststroke. Surface EMG signals were collected using a 64-channel 2-D electrode array from the paretic and contralateral first dorsal interosseous (FDI) muscles of nine hemiparetic stroke subjects at different isometric discrete contraction levels between 2 to 10 N with a 2 N increment step. Motor unit firing rates were extracted through decomposition of the high-density surface EMG signals and compared between paretic and contralateral muscles. Across the nine tested subjects, paretic FDI muscles showed decreased motor unit firing rates compared with contralateral muscles at different contraction levels. Regression analysis indicated a linear relation between the mean motor unit firing rate and the muscle contraction level for both paretic and contralateral muscles (p < 0.001), with the former demonstrating a lower increment rate (0.32 pulses per second (pps)/N) compared with the latter (0.67 pps/N). The coefficient of variation (averaged over the contraction levels) of the motor unit firing rates for the paretic muscles (0.21 ± 0.012) was significantly higher than for the contralateral muscles (0.17 ± 0.014) (p < 0.05). This study provides direct evidence of motor unit firing behavior alterations poststroke using surface EMG, which can be an important factor contributing to hemiparetic muscle weakness.

Examination of Post-stroke Alteration in Motor Unit Firing Behavior Using High Density Surface EMG Decomposition

PubMed Central

Li, Xiaoyan; Holobar, Aleš; Gazzoni, Marco; Merletti, Roberto; Rymer, William Z.; Zhou, Ping

2014-01-01

Recent advances in high density surface electromyogram (EMG) decomposition have made it a feasible task to discriminate single motor unit activity from surface EMG interference patterns, thus providing a noninvasive approach for examination of motor unit control properties. In the current study we applied high density surface EMG recording and decomposition techniques to assess motor unit firing behavior alterations post-stroke. Surface EMG signals were collected using a 64-channel 2-dimensional electrode array from the paretic and contralateral first dorsal interosseous (FDI) muscles of nine hemiparetic stroke subjects at different isometric discrete contraction levels between 2 N to 10 N with a 2 N increment step. Motor unit firing rates were extracted through decomposition of the high density surface EMG signals, and compared between paretic and contralateral muscles. Across the nine tested subjects, paretic FDI muscles showed decreased motor unit firing rates compared with contralateral muscles at different contraction levels. Regression analysis indicated a linear relation between the mean motor unit firing rate and the muscle contraction level for both paretic and contralateral muscles (p < 0.001), with the former demonstrating a lower increment rate (0.32 pulses per second (pps)/N) compared with the latter (0.67 pps/N). The coefficient of variation (CoV, averaged over the contraction levels) of the motor unit firing rates for the paretic muscles (0.21 ± 0.012) was significantly higher than for the contralateral muscles (0.17 ± 0.014) (p < 0.05). This study provides direct evidence of motor unit firing behavior alterations post-stroke using surface EMG, which can be an important factor contributing to hemiparetic muscle weakness. PMID:25389239

Evaluation of root and alveolar bone development of unilateral osseous impacted immature maxillary central incisors after the closed-eruption technique.

PubMed

Shi, Xiangru; Xie, Xiaoyan; Quan, Junkang; Wang, Xiaozhe; Sun, Xiangyu; Zhang, Chenying; Zheng, Shuguo

2015-10-01

In this study, we evaluated root and alveolar bone development in unilateral osseous impacted immature maxillary central incisors by cone-beam computed tomography before and after closed-eruption treatment, in comparison with naturally erupted contralateral immature maxillary central incisors. The study included 30 patients, 20 boys and 10 girls, with a mean age of 8.44 ± 1.20 years (range, 6.5-11.2 years). After treatment, the root lengths of both the impacted maxillary central incisors (10.66 ± 2.10 mm) and the contralateral maxillary central incisors (11.04 ± 1.76 mm) were significantly greater than their pretreatment values (6.67 ± 1.94 and 9.02 ± 2.13 mm, respectively). The root canal widths of the incisors decreased significantly after treatment. From the posttreatment cone-beam computed tomography images, the ratio of exposed root length to total root length and the thickness of the alveolar bone at 1 mm under the alveolar crest and at the apex were calculated to evaluate alveolar bone development. Impacted immature maxillary central incisors differed significantly from contralateral immature maxillary central incisors in labial exposed root length, labial ratio to total root length, and lingual alveolar crest. Clinical crown height was higher (statistically but not clinically) for the impacted incisors (9.87 mm) than for the contralateral incisors (9.37 mm). Impacted immature incisors grew to the same stage as did erupted contralateral incisors after closed-eruption treatment. Both incisor types had some alveolar bone loss, and thin alveolar bone surrounded the roots. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Two-year analysis for predicting renal function and contralateral hypertrophy after robot-assisted partial nephrectomy: A three-dimensional segmentation technology study.

PubMed

Kim, Dae Keun; Jang, Yujin; Lee, Jaeseon; Hong, Helen; Kim, Ki Hong; Shin, Tae Young; Jung, Dae Chul; Choi, Young Deuk; Rha, Koon Ho

2015-12-01

To analyze long-term changes in both kidneys, and to predict renal function and contralateral hypertrophy after robot-assisted partial nephrectomy. A total of 62 patients underwent robot-assisted partial nephrectomy, and renal parenchymal volume was calculated using three-dimensional semi-automatic segmentation technology. Patients were evaluated within 1 month preoperatively, and postoperatively at 6 months, 1 year and continued up to 2-year follow up. Linear regression models were used to identify the factors predicting variables that correlated with estimated glomerular filtration rate changes and contralateral hypertrophy 2 years after robot-assisted partial nephrectomy. The median global estimated glomerular filtration rate changes were -10.4%, -11.9%, and -2.4% at 6 months, 1 and 2 years post-robot-assisted partial nephrectomy, respectively. The ipsilateral kidney median parenchymal volume changes were -24%, -24.4%, and -21% at 6 months, 1 and 2 years post-robot-assisted partial nephrectomy, respectively. The contralateral renal volume changes were 2.3%, 9.6% and 12.9%, respectively. On multivariable linear analysis, preoperative estimated glomerular filtration rate was the best predictive factor for global estimated glomerular filtration rate change on 2 years post-robot-assisted partial nephrectomy (B -0.452; 95% confidence interval -0.84 to -0.14; P = 0.021), whereas the parenchymal volume loss rate (B -0.43; 95% confidence interval -0.89 to -0.15; P = 0.017) and tumor size (B 5.154; 95% confidence interval -0.11 to 9.98; P = 0.041) were the significant predictive factors for the degree of contralateral renal hypertrophy on 2 years post-robot-assisted partial nephrectomy. Preoperative estimated glomerular filtration rate significantly affects post-robot-assisted partial nephrectomy renal function. Renal mass size and renal parenchyma volume loss correlates with compensatory hypertrophy of the contralateral kidney. Contralateral hypertrophy of the renal parenchyma compensates for the functional loss of the ipsilateral kidney. © 2015 The Japanese Urological Association.

Defocus-induced changes in ZENK expression in the chicken retina.

PubMed

Bitzer, Michaela; Schaeffel, Frank

2002-01-01

To characterize the visual stimuli that control the expression of the transcription factor ZENK in glucagon-immunoreactive amacrine cells of the chicken retina. ZENK was previously found to change in correlation with the sign (+ or -) of imposed defocus, making it a potential candidate for regulation of the synthesis of growth factors involved in emmetropization. Chicks were unilaterally treated with positive or negative lenses from 40 minutes to 2 hours. They were either kept in their cage environment (1000 lux) or in a large hemispheric dome under more homogeneous illumination (300 lux) in white or quasimonochromatic light (555 nm). In another experiment they were permitted only one viewing distance. ZENK expression was quantified in glucagon amacrine cells after the different treatments by means of double staining and cell counting. In all conditions tested, the number of ZENK-expressing cells was increased with positive lenses and reduced with negative lenses after only 40 minutes of exposure. If only one viewing distance was possible, the level of ZENK still responded to the sign of imposed defocus, although it required 80 minutes of treatment. In this experiment, the interocular difference was largely produced by changes in the contralateral control eyes rather than the lens-treated eyes. Finally, changes in ZENK expression appeared to be related to lens powers with a sigmoidal function, with saturation at approximately +7 D and -7 D of defocus, respectively. The results confirm that changes in ZENK expression are selective for the sign of imposed defocus. They may be independent of illuminance and do not require chromatic cues or variable viewing distances. The pathways for the substantial interactions between both eyes are not clear at present.

[Three cases of an intracranial wooden foreign body].

PubMed

Fujimoto, S; Onuma, T; Amagasa, M; Okudaira, Y

1987-07-01

Three cases of intracranial wooden foreign body are reported discussing the diagnostic and therapeutic problems. First case is a 50-year-old man. After drinking, he drove a bike and fell to the ground. On admission the wooden foreign body could not been detected in appearance. CT scan showed low density area similar to air in bilateral anterior horn of lateral ventricle. The patient was treated for traumatic pneumocephalus at first. Later, it proved that he was stabbed with a foreign body penetrating into the contralateral frontal lobe through the left nasal cavity. It was extracted by endonasal approach by otolaryngologist, fortunately without trouble. The foreign body was a branch of tree. The second case is an 18-year-old man. He was driving a car, and suffered injury. He was stabbed with a wooden stake penetrating into his left eye. Immediately, bifrontal craniotomy was performed and the stake was withdrawn carefully. Moreover bone fragments were removed. The third case is a 61-year-old man. When he cut the timber by chain saw, a piece of wood hit and stabbed his right eye directly. Immediately right front temporal craniotomy was performed. The piece of wood was withdrawn from the right eye, and pieces of glass, wood and bone fragments were evacuated. It is difficult to confirm intracranial foreign body accurately by means of only plain skull film and usual CT scans. It is necessary to utilize various function of CT scanner. For example, it is useful to know CT values or select measure mode with window width and level or make reconstruction image to sagittal or coronal section, and so on.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of the intraocular jet flows and pressure gradients induced by air and fluid infusion: mechanism of focal chorioretinal damage.

PubMed

Kim, Yong Joon; Jo, Sungkil; Moon, Daruchi; Joo, Youngcheol; Choi, Kyung Seek

2014-05-01

To comprehend the mechanism of focal chorioretinal damage by analysis of the pressure distribution and dynamic pressure induced by infused air during fluid-air exchange. A precise simulation featuring a model eye and a fluid circuit was designed to analyze fluid-air exchange. The pressure distribution, flow velocity, and dynamic pressure induced by infusion of air into an air-filled eye were analyzed using an approach based on fluid dynamics. The size of the port and the infusion pressure were varied during simulated iterations. We simulated infusion of an air-filled eye with balanced salt solution (BSS) to better understand the mechanism of chorioretinal damage induced by infused air. Infused air was projected straight toward a point on the retina contralateral to the infusion port (the "vulnerable point"). The highest pressure was evident at the vulnerable point, and the lowest pressure was recorded on most retinal areas. Simulations using greater infusion pressure and a port of larger size were associated with elevations in dynamic pressure and the pressure gradient. The pressure gradients were 2.8 and 5.1 mm Hg, respectively, when infusion pressures of 30 and 50 mm Hg were delivered through a 20-gauge port. The pressure gradient associated with BSS infusion was greater than that created by air, but lasted for only a moment. Our simulation explains the mechanism of focal chorioretinal damage in numerical terms. Infused air induces a prolonged increase in focal pressure on the vulnerable point, and this may be responsible for visual field defects arising after fluid-air exchange. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Patient-Specific Computational Modeling of Keratoconus Progression and Differential Responses to Collagen Cross-linking

PubMed Central

Sinha Roy, Abhijit

2011-01-01

Purpose. To model keratoconus (KC) progression and investigate the differential responses of central and eccentric cones to standard and alternative collagen cross-linking (CXL) patterns. Methods. Three-dimensional finite element models (FEMs) were generated with clinical tomography and IOP measurements. Graded reductions in regional corneal hyperelastic properties and thickness were imposed separately in the less affected eye of a KC patient. Topographic results, including maximum curvature and first-surface, higher-order aberrations (HOAs), were compared to those of the more affected contralateral eye. In two eyes with central and eccentric cones, a standard broad-beam CXL protocol was simulated with 200- and 300-μm treatment depths and compared to spatially graded broad-beam and cone-centered CXL simulations. Results. In a model of KC progression, maximum curvature and HOA increased as regional corneal hyperelastic properties were decreased. A topographic cone could be generated without a reduction in corneal thickness. Simulation of standard 9-mm-diameter CXL produced decreases in corneal curvature comparable to clinical reports and affected cone location. A 100-μm increase in CXL depth enhanced flattening by 24% to 34% and decreased HOA by 22% to 31%. Topographic effects were greatest with cone-centered CXL simulations. Conclusions. Progressive hyperelastic weakening of a cornea with subclinical KC produced topographic features of manifest KC. The clinical phenomenon of topographic flattening after CXL was replicated. The magnitude and higher-order optics of this response depended on IOP and the spatial distribution of stiffening relative to the cone location. Smaller diameter simulated treatments centered on the cone provided greater reductions in curvature and HOA than a standard broad-beam CXL pattern. PMID:22039252

Stimulation of the substantia nigra influences the specification of memory-guided saccades

PubMed Central

Mahamed, Safraaz; Garrison, Tiffany J.; Shires, Joel

2013-01-01

In the absence of sensory information, we rely on past experience or memories to guide our actions. Because previous experimental and clinical reports implicate basal ganglia nuclei in the generation of movement in the absence of sensory stimuli, we ask here whether one output nucleus of the basal ganglia, the substantia nigra pars reticulata (nigra), influences the specification of an eye movement in the absence of sensory information to guide the movement. We manipulated the level of activity of neurons in the nigra by introducing electrical stimulation to the nigra at different time intervals while monkeys made saccades to different locations in two conditions: one in which the target location remained visible and a second in which the target location appeared only briefly, requiring information stored in memory to specify the movement. Electrical manipulation of the nigra occurring during the delay period of the task, when information about the target was maintained in memory, altered the direction and the occurrence of subsequent saccades. Stimulation during other intervals of the memory task or during the delay period of the visually guided saccade task had less effect on eye movements. On stimulated trials, and only when the visual stimulus was absent, monkeys occasionally (∼20% of the time) failed to make saccades. When monkeys made saccades in the absence of a visual stimulus, stimulation of the nigra resulted in a rotation of the endpoints ipsilaterally (∼2°) and increased the reaction time of contralaterally directed saccades. When the visual stimulus was present, stimulation of the nigra resulted in no significant rotation and decreased the reaction time of contralaterally directed saccades slightly. Based on these measurements, stimulation during the delay period of the memory-guided saccade task influenced the metrics of saccades much more than did stimulation during the same period of the visually guided saccade task. Because these effects occurred with manipulation of nigral activity well before the initiation of saccades and in trials in which the visual stimulus was absent, we conclude that information from the basal ganglia influences the specification of an action as it is evolving primarily during performance of memory-guided saccades. When visual information is available to guide the specification of the saccade, as occurs during visually guided saccades, basal ganglia information is less influential. PMID:24259551

Limiting Radiotherapy to the Contralateral Retropharyngeal and High Level II Lymph Nodes in Head and Neck Squamous Cell Carcinoma is Safe and Improves Quality of Life

PubMed Central

Spencer, Christopher R.; Gay, Hiram A.; Haughey, Bruce H.; Nussenbaum, Brian; Adkins, Douglas R.; Wildes, Tanya M.; DeWees, Todd A.; Lewis, James S.; Thorstad, Wade L.

2014-01-01

Background Radiation treatment volumes in head and neck squamous cell carcinoma (HNSCC) are controversial. Here we report the outcomes, failures, and quality of life (QOL) of patients treated using intensity modulated radiation therapy (IMRT) that eliminated treatment of contralateral retropharyngeal lymph nodes (RPLN) in the clinically uninvolved neck. Methods A prospective institutional database identified patients with primary oral cavity, oropharynx, hypopharynx, larynx and unknown primary HNSCC treated using IMRT. There were three temporal groups (G1-3). G1 received comprehensive neck IMRT with parotid sparing, G2 eliminated the contralateral high level II (HLII) lymph nodes, and G3 further eliminated the contralateral RPLN in the clinically uninvolved neck. Patterns of failure and survival analyses were completed and QOL data measured by the MD Anderson Dysphagia Inventory (MDADI) was compared in a subset of patients from G1 and G3. Results There were 748 patients identified. Of the 488 patients treated in G2 or G3, 406 had a clinically uninvolved contralateral neck. There were no failures in the spared RPLNs (95% CI; 0-1.3%) or high contralateral neck (95% CI; 0-0.7%). QOL data was compared between 44 patients in G1 and 51 patients in G3. QOL improved both globally and in all domains assessed for G3 in which reduced radiotherapy volumes were used (p < 0.007). Conclusions For patients with locally advanced HNSCC, eliminating coverage to the contralateral HLII and contralateral RPLN in the clinically uninvolved side of the neck is associated with minimal risk of failure in these regions and significantly improved patient-reported QOL. PMID:25143048

Decreased contralateral breast volume after mastectomy, adjuvant chemotherapy, and anti-estrogen therapy, in particular in breasts with high density.

PubMed

Ishii, Naohiro; Ando, Jiro; Harao, Michiko; Takemae, Masaru; Kishi, Kazuo

2017-10-01

Adjuvant chemotherapy and anti-estrogenic therapy can result in decreased volume of the contralateral breast, following mastectomy for the treatment of breast cancer. However, no data on the effect of adjuvant therapy on contralateral breast volume have previously been reported. We aimed to evaluate the extent to which adjuvant therapy and differences in breast density contribute to decreased breast volume. We conducted a prospective cohort study, selecting 40 nonconsecutive patients who underwent immediate breast reconstruction with mastectomy and expander insertion followed by expander replacement. We measured the contralateral breast volume before each procedure. The extent of the change was analyzed with respect to adjuvant therapy and breast density measured by preoperative mammography. The greatest decrease in breast volume was 135.1 cm 3 . The decrease in breast volume was significantly larger in the adjuvant therapy (+) group, particularly in patients with high breast density, than in the adjuvant therapy (-) group. Significant differences between the chemotherapy (+), tamoxifen (+) group and the chemotherapy (-), tamoxifen (+) group were not found. Breast density scores had a range of 2.0-3.3 (mean: 2.8). In breast reconstruction, particularly when performed in one stage, preoperative mammography findings are valuable to plastic surgeons, and possible decreases in the contralateral breast volume due to adjuvant therapy, particularly in patients with high breast density, should be considered carefully. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Contralateral suppression of transient-evoked otoacoustic emissions in children with sickle cell disease.

PubMed

Stuart, Andrew; Preast, June L

2012-01-01

In previous studies, otoacoustic emissions (OAEs) have been found to be larger in normal-hearing children with sickle cell disease (SCD). It was hypothesized that some dysfunction or reduction in the medial olivocochlear efferent suppression of outer hair cell activity was responsible for this phenomenon. To test this hypothesis, contralateral suppression of transient-evoked otoacoustic emissions (TEOAEs) was examined in children with and without SCD. Thirteen African American school-aged normal-hearing children with homozygous SCD and 13 age- and gender-matched control children participated. TEOAEs were obtained bilaterally with 80 dB peSPL nonlinear click stimuli. To examine contralateral suppression, TEOAEs were obtained with 60 dB peSPL linear click stimuli with and without a contralateral 65 dB SPL white noise suppressor. Overall and half-octave band TEOAE levels were found to be larger in children with SCD relative to the normal control children (p < 0.05), consistent with previous reports of increased OAE levels. There was no significant difference (p > 0.05) in the absolute or proportional amount of TEOAE suppression as a function of group and ear. There were also no significant correlations or linear predictive relationships between TEOAE suppression and TEOAE level for either ear or group (p > 0.05). These findings do not support the notion that increased OAE levels in children with SCD are a consequence of abnormal medial olivocochlear system function as assessed with contralateral suppression of TEOAEs.

Single-session tDCS over the dominant hemisphere affects contralateral spectral EEG power, but does not enhance neurofeedback-guided event-related desynchronization of the non-dominant hemisphere's sensorimotor rhythm.

PubMed

Mondini, Valeria; Mangia, Anna Lisa; Cappello, Angelo

2018-01-01

Transcranial direct current stimulation (tDCS) and neurofeedback-guided motor imagery (MI) have attracted considerable interest in neurorehabilitation, given their ability to influence neuroplasticity. As tDCS has been shown to modulate event-related desynchronization (ERD), the neural signature of motor imagery detected for neurofeedback, a combination of the techniques was recently proposed. One limitation of this approach is that the area targeted for stimulation is the same from which the signal for neurofeedback is acquired. As tDCS may interfere with proximal electroencephalographic (EEG) electrodes, in this study our aim was to test whether contralateral tDCS could have interhemispheric effects on the spectral power of the unstimulated hemisphere, possibly mediated by transcallosal connection, and whether such effects could be used to enhance ERD magnitudes. A contralateral stimulation approach would indeed facilitate co-registration, as the stimulation electrode would be far from the recording sites. Twenty right-handed healthy volunteers (aged 21 to 32) participated in the study: ten assigned to cathodal, ten to anodal versus sham stimulation. We applied stimulation over the dominant (left) hemisphere, and assessed ERD and spectral power over the non-dominant (right) hemisphere. The effect of tDCS was evaluated over time. Spectral power was assessed in theta, alpha and beta bands, under both rest and MI conditions, while ERD was evaluated in alpha and beta bands. Two main findings emerged: (1) contralateral alpha-ERD was reduced after anodal (p = 0.0147), but not enhanced after cathodal tDCS; (2) both stimulations had remote effects on the spectral power of the contralateral hemisphere, particularly in theta and alpha (significant differences in the topographical t-value maps). The absence of contralateral cathodal ERD enhancement suggests that the protocol is not applicable in the context of MI training. Nevertheless, ERD results of anodal and spectral power results of both stimulations complement recent findings on the distant tDCS effects between functionally related areas.

Single-session tDCS over the dominant hemisphere affects contralateral spectral EEG power, but does not enhance neurofeedback-guided event-related desynchronization of the non-dominant hemisphere's sensorimotor rhythm

PubMed Central

Mangia, Anna Lisa; Cappello, Angelo

2018-01-01

Background and objective Transcranial direct current stimulation (tDCS) and neurofeedback-guided motor imagery (MI) have attracted considerable interest in neurorehabilitation, given their ability to influence neuroplasticity. As tDCS has been shown to modulate event-related desynchronization (ERD), the neural signature of motor imagery detected for neurofeedback, a combination of the techniques was recently proposed. One limitation of this approach is that the area targeted for stimulation is the same from which the signal for neurofeedback is acquired. As tDCS may interfere with proximal electroencephalographic (EEG) electrodes, in this study our aim was to test whether contralateral tDCS could have interhemispheric effects on the spectral power of the unstimulated hemisphere, possibly mediated by transcallosal connection, and whether such effects could be used to enhance ERD magnitudes. A contralateral stimulation approach would indeed facilitate co-registration, as the stimulation electrode would be far from the recording sites. Methods Twenty right-handed healthy volunteers (aged 21 to 32) participated in the study: ten assigned to cathodal, ten to anodal versus sham stimulation. We applied stimulation over the dominant (left) hemisphere, and assessed ERD and spectral power over the non-dominant (right) hemisphere. The effect of tDCS was evaluated over time. Spectral power was assessed in theta, alpha and beta bands, under both rest and MI conditions, while ERD was evaluated in alpha and beta bands. Results Two main findings emerged: (1) contralateral alpha-ERD was reduced after anodal (p = 0.0147), but not enhanced after cathodal tDCS; (2) both stimulations had remote effects on the spectral power of the contralateral hemisphere, particularly in theta and alpha (significant differences in the topographical t-value maps). Conclusion The absence of contralateral cathodal ERD enhancement suggests that the protocol is not applicable in the context of MI training. Nevertheless, ERD results of anodal and spectral power results of both stimulations complement recent findings on the distant tDCS effects between functionally related areas. PMID:29513682

Impact of Node Negative Target Volume Delineation on Contralateral Parotid Gland Dose Sparing Using IMRT in Head and Neck Cancer.

PubMed

Magnuson, William J; Urban, Erich; Bayliss, R Adam; Harari, Paul M

2015-06-01

There is considerable practice variation in treatment of the node negative (N0) contralateral neck in patients with head and neck cancer. In this study, we examined the impact of N0 neck target delineation volume on radiation dose to the contralateral parotid gland. Following institutional review board approval, 12 patients with head and neck cancer were studied. All had indications for treatment of the N0 neck, such as midline base of tongue or soft palate extension or advanced ipsilateral nodal disease. The N0 neck volumes were created using the Radiation Therapy Oncology Group head and neck contouring atlas. The physician-drawn N0 neck clinical target volume (CTV) was expanded by 25% to 200% to generate volume variation, followed by a 3-mm planning target volume (PTV) expansion. Surrounding organs at risk were contoured and complete intensity-modulated radiation therapy plans were generated for each N0 volume expansion. The median N0 target volume drawn by the radiation oncologist measured 93 cm(3) (range 71-145). Volumetric expansion of the N0 CTV by 25% to 200% increased the resultant mean dose to the contralateral parotid gland by 1.4 to 8.5 Gray (Gy). For example, a 4.1-mm increase in the N0 neck CTV translated to a 2.0-Gy dose increase to the parotid, 7.4 mm to a 4.5 Gy dose increase, and 12.5 mm to an 8.5 Gy dose increase, respectively. The treatment volume designated for the N0 neck has profound impact on resultant dose to the contralateral parotid gland. Variations of up to 15 mm are routine across physicians in target contouring, reflecting individual preference and training expertise. Depending on the availability of immobilization and image guidance techniques, experts commonly recommend 3 to 10 mm margin expansions to generate the PTV. Careful attention to the original volume of the N0 neck CTV, as well as expansion margins, is important in achieving effective contralateral gland sparing to reduce the resultant xerostomia and dysguesia that may ensue after radiotherapy. © The Author(s) 2014.

Three-dimensional in vivo patellofemoral kinematics and contact area of anterior cruciate ligament-deficient and -reconstructed subjects using magnetic resonance imaging.

PubMed

Shin, Choongsoo S; Carpenter, R Dana; Majumdar, Sharmila; Ma, C Benjamin

2009-11-01

The purpose of this study was to test whether (1) the 3-dimensional in vivo patellofemoral kinematics and patellofemoral contact area of anterior cruciate ligament (ACL)-deficient knees are different from those of normal, contralateral knees and (2) ACL reconstruction restores in vivo patellofemoral kinematics and contact area. Ten ACL-deficient knees and twelve ACL-reconstructed knees, as well as the contralateral uninjured knees, were tested. Magnetic resonance imaging was performed at full extension and 40 degrees of flexion under simulated partial weight-bearing conditions. Six-degrees of freedom patellofemoral kinematics, patellofemoral contact area, and contact location were analyzed by use of magnetic resonance image-based 3-dimensional patellofemoral knee models. The patella in the ACL-deficient knees underwent significantly more lateral tilt during flexion (P < .05) and tended to translate more laterally (P = .083) than the patella in contralateral knees. After ACL reconstruction, no kinematic parameters were significantly different from those in contralateral knees. The patellofemoral contact areas of ACL-deficient knees at both the extended and flexed positions (37 +/- 22 mm(2) and 357 +/- 53 mm(2), respectively) were significantly smaller than those of contralateral knees (78 +/- 45 mm(2) and 437 +/- 119 mm(2), respectively) (P < .05). After reconstruction, the patellofemoral contact area of ACL-reconstructed knees in the extended position (86 +/- 41 mm(2)) was significantly larger (P < .05) than that of contralateral knees (50 +/- 34 mm(2)), but no difference was detected in the flexed position. Reproducibility of all patellofemoral kinematic parameters, contact centroid translation, and contact area showed coefficients of variation of less than 6.8%. ACL injuries alter patellofemoral kinematics including patellar tilt and patellar lateral translation, but ACL reconstruction with hamstring or allograft restores altered patellar tilt. ACL injuries reduce the patellofemoral contact area at both the extended and flexed positions, but ACL reconstruction enlarges the patellofemoral contact area at extension and restores the normal contact area at low angles of flexion. Level III, case-control study.

The evolution of contralateral control of the body by the brain: is it a protective mechanism?

PubMed

Whitehead, Lorne; Banihani, Saleh

2014-01-01

Contralateral control, the arrangement whereby most of the human motor and sensory fibres cross the midline in order to provide control for contralateral portions of the body, presents a puzzle from an evolutionary perspective. What caused such a counterintuitive and complex arrangement to become dominant? In this paper we offer a new perspective on this question by showing that in a complex interactive control system there could be a significant net survival advantage with contralateral control, associated with the effect of injuries of intermediate severity. In such cases an advantage could arise from a combination of non-linear system response combined with correlations between injuries on the same side of the head and body. We show that a simple mathematical model of these ideas emulates such an advantage. Based on this model, we conclude that effects of this kind are a plausible driving force for the evolution of contralateral control.

Spaceflight Effects and Molecular Responses in the Mouse Eye: Observations after NASA Shuttle Mission STS-133

NASA Technical Reports Server (NTRS)

ProsperoPonce, Claudia Maria; Zanello, Susana B.; Theriot, Corey A.; Chevez-Barrios, Patricia

2012-01-01

Background: Human space exploration implies a combination of stressors including microgravityinduced cephalad fluid shift and radiation exposure. Ocular changes in astronauts leading to visual impairment are of occupational health relevance. The effect of this complex environment on ocular morphology and function is poorly understood. Material and Methods: Mice were assigned to a Flight (FLT) group flown on shuttle mission STS133, Animal Enclosure Module (AEM), or vivarium (VIV) ground controls. Eyes were collected at 1, 5 and 7 days after landing, and were fixed for histological sectioning. The contralateral eye was used for gene expression profiling by qRT-PCR. Routine histology and immunohistochemistry using 8-hydroxy-2'-deoxyguanosine (8-OHdG), caspase-3, glial fibrillary acidic protein (GFAP) and beta-amyloid were used to study the eyes. Results and Conclusions: 8-OHdG and caspase-3 immunoreactivity was increased in the retina in FLT samples at return from flight (R+1) compared to ground controls, and decreased at day 7 (R+7), suggesting an increase in oxidative stress and cell apoptosis. FLT mice showed evidence of retinal pigment epithelium (RPE) apoptosis possibly secondary to oxidative damage. Although attenuation of RPE has been related to retinal choroidal folds in astronauts, it is yet to be determined whether or not increased RPE apoptosis may contribute to the formation of choroidal folds or may increase the risk for other retinal pathologies, such as AMD. beta-amyloid was seen in the nerve fibers at the post-laminar region of the optic nerve in the flight samples (R+7). Deposition of beta-amyloid has a strong correlation with mechanical trauma. The coexpression of GFAP in astrocytes and oligodentrocytes in these same areas supports the possible mechanical origin probably secondary to intracranial pressure that is transmitted into the nerve, as a result of an increase in venous pressure associated to microgravity-induced cephalic fluid shift. However, there is the need to further investigate the nature of the changes through additional experimental work. Gene expression of oxidative and cellular stress response genes was unregulated in the retina of FLT samples upon landing followed by lower levels by R+7. These results suggest that reversible molecular damage occurs in the retina of mice exposed to spaceflight and that protective cellular and molecular pathways are induced in the retina in response to these changes.

Ipsilateral Breast Tumor Reappearance and Contralateral Breast Cancer after Primary Breast Cancer Treatment: A Comprehensive Retrospective Study of 15,168 Patients.

PubMed

Corso, Giovanni; Maisonneuve, Patrick; Santomauro, Giorgia Irene; De Scalzi, Alessandra Margherita; Toesca, Antonio; Bassi, Fabio Domenico; Farante, Gabriel; Caldarella, Pietro; Intra, Mattia; Galimberti, Viviana; Veronesi, Paolo

2018-05-30

The aim of this retrospective study was to assess the risk factors for developing ipsilateral breast tumor reappearance (IBTR) and de novo contralateral breast cancer (BC) after primary BC treatment. Retrospectively, 15,168 consecutive patients with primary monolateral BC were enrolled in this monocentric study (from June 1994 to December 2006). Clinicopathological features, follow-up, and survival at 15 years were considered for statistical analysis. Significant associations of increased risk for IBTR were verified with metastatic axillary lymph nodes (HR 1.37 [1.15-1.62], p = 0.0004), high tumor grade G2 (HR 1.35 [1.05-1.74], p = 0.02) and G3 (HR 1.35 [1.01-1.79], p = 0.04), luminal B (HR 1.51 [1.25-1.82], p < 0.0001), and HER2-positive (HR1.66 [1.14-2.41], p = 0.008) and triple-negative subtype (HR 1.54 [1.07-2.21], p = 0.02). Older age (HR 1.44 [1.08-1.91], p = 0.01) and positive family history (HR 1.85 [1.47-2.32], p < 0.0001) were risk factors for contralateral BC. Significant protective factors for IBTR were hormonotherapy (HR 0.71 [0.59-0.85], p = 0.0003), chemotherapy (HR 0.72 [0.60-0.87], p = 0.001), and radiotherapy (HR 0.73 [0.61-0.87], p = 0.0005). Hormonotherapy was also confirmed as a protective factor for contralateral second BC (HR 0.43 [0.30-0.60], p < 0.0001). We classified factors for IBTR and contralateral BC in high- and low-risk groups. In the high-risk group, breast surgery still remains more important than in the low-risk group, which seems to benefit more from adjuvant treatments. © 2018 S. Karger AG, Basel.

Efficacy of laparoscopically assisted high ligation of patent processus vaginalis in children.

PubMed

Ahmed, H; Youssef, M K; Salem, E A; Fawzi, A M; Desoky, E A E; Eliwa, A M; Sakr, A M N; Shahin, A M S

2016-02-01

Laparoscopic hernia repairs have been proven to be efficient and safe for children, despite the slightly higher recurrence rate compared with the classic surgical repair. They have the advantage of easy and precise identification of the type of defect and its correction, both in ipsilateral and contralateral sides. The objectives of this study were to evaluate the efficacy, safety and outcome of the laparoscopically assisted piecemeal high ligation of a patent processus vaginalis (PPV) in children. A total of 40 children were enrolled into this prospective study; they were aged ≥ 6 months and had an inguinal hernia. The peritoneal cavity, including the contralateral side, was inspected for the possibility of bilateral hernias using a 3-mm 30° telescope. Another 3-mm port was introduced through the same infra-umbilical incision. The hernia was manually reduced or with the aid of a working infra-umbilical grasper. A prolene or vicryl 2/0 or 3/0 suture on a curved semicircle round-bodied taper-ended 25-30 mm needle was introduced through a very small inguinal skin-crease incision. It was passed through the abdominal wall layers to the peritoneum and was manipulated by the laparoscopic grasper to pick up the peritoneum in piecemeal all around the internal ring. The needle was then pushed to the outside near to the entrance site, thus forming a semicircle around the internal ring. The suture was then tied and the knot was subcutaneously buried. The primary outcome of the procedure was the incidence of intraoperative diagnosis and surgical repair of contralateral hernias in pre-operatively diagnosed unilateral cases. The secondary outcomes were defined as the incidence of complications and hernia recurrence. The exploratory laparoscopy found contralateral patent processus vaginalis (CPPV) with a detection rate of 28.1%. Chan et al., Esposito et al., Toufique et al. and Niyogi et al. reported similar figures for laparoscopic contralateral hernia detection rates of 28%, 39%, 39.7% and 29.2%, respectively. The limitations of this study were the small sample size, plus the risk factors and clinical significance for CPPV. Laparascopically assisted piecemeal closure of the internal inguinal ring in children is a safe and effective procedure. It helps in detecting a contralateral hernia without prolonging the operative time. Copyright © 2015 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Postoperative Time Dependent Tibiofemoral Articular Cartilage Contact Kinematics during Step-up after ACL Reconstruction

PubMed Central

Lin, Lin; Li, Jing-Sheng; Kernkamp, Willem A.; Hosseini, Ali; Kim, ChangWan; Yin, Peng; Wang, Lianxin; Tsai, Tsung-Yuan; Asnis, Peter; Li, Guoan

2016-01-01

This study was to investigate the in vivo tibiofemoral cartilage contact locations before and after anterior cruciate ligament (ACL) reconstruction at 6 and 36 months. Ten patients with unilateral ACL injury were included. A step-up motion was analyzed using a combined magnetic resonance modeling and dual fluoroscopic imaging techniques. The preoperative (i.e. ACL deficient and healthy contralateral) and postoperative cartilage contact locations at 6 and 36 months were analyzed. Similar patterns of the cartilage contact locations during the step-up motion were found for the preoperative and postoperative knee states as compared to the preoperative healthy contralateral side. At the end of step-up motion, the medial contact locations at postoperative 36 months were more anterior when compared to the preoperative healthy contralateral (p=0.02) and 6 months postoperative knee states (p=0.01). The changes of the cartilage contact locations at 36 months after ACL reconstruction compared to the healthy contralateral side were strongly correlated with the changes at 6 months postoperatively. This study showed that the tibiofemoral cartilage contact locations of the knee changes with time after ACL reconstruction, implying an ongoing recovery process within the 36 months after the surgery. There could be an association between the short-term (6 months) and longer-term (36 months) contact kinematics after ACL reconstruction. Future studies need to investigate the intrinsic relationship between knee kinematics at different times after ACL reconstruction. PMID:27720228

Decoding of intended saccade direction in an oculomotor brain-computer interface

NASA Astrophysics Data System (ADS)

Jia, Nan; Brincat, Scott L.; Salazar-Gómez, Andrés F.; Panko, Mikhail; Guenther, Frank H.; Miller, Earl K.

2017-08-01

Objective. To date, invasive brain-computer interface (BCI) research has largely focused on replacing lost limb functions using signals from the hand/arm areas of motor cortex. However, the oculomotor system may be better suited to BCI applications involving rapid serial selection from spatial targets, such as choosing from a set of possible words displayed on a computer screen in an augmentative and alternative communication (AAC) application. Here we aimed to demonstrate the feasibility of a BCI utilizing the oculomotor system. Approach. We developed a chronic intracortical BCI in monkeys to decode intended saccadic eye movement direction using activity from multiple frontal cortical areas. Main results. Intended saccade direction could be decoded in real time with high accuracy, particularly at contralateral locations. Accurate decoding was evident even at the beginning of the BCI session; no extensive BCI experience was necessary. High-frequency (80-500 Hz) local field potential magnitude provided the best performance, even over spiking activity, thus simplifying future BCI applications. Most of the information came from the frontal and supplementary eye fields, with relatively little contribution from dorsolateral prefrontal cortex. Significance. Our results support the feasibility of high-accuracy intracortical oculomotor BCIs that require little or no practice to operate and may be ideally suited for ‘point and click’ computer operation as used in most current AAC systems.

New Technique of Exposed Glaucoma Drainage Tube Repair: Report of a Case.

PubMed

Berezina, Tamara L; Fechtner, Robert D; Cohen, Amir; Kim, Eliott E; Chu, David S

2015-01-01

We present the case of successful repair of an exposed glaucoma drainage tube by cornea graft fixation with tissue adhesive, and without subsequent coverage by adjacent conjunctiva or donor tissues. Patient with history of keratoglobus with thin cornea and sclera, and phthisical contralateral eye, underwent three unsuccessful corneal grafts followed by Boston type 1 keratoprosthesis in the right eye. Ahmed drainage device with sclera patch graft was implanted to control the intraocular pressure. Two years later the tube eroded through sclera graft and conjunctiva. Repair was performed by covering the tube with a corneal patch graft secured by tissue adhesive after the conjunctiva in this area was dissected away. The cornea graft was left uncovered due to fragility of adjacent conjunctiva. The healing of ocular and graft surfaces was complete prior to the 1 month follow-up. Conjunctival epithelium covered the corneal patch graft. At 12 months follow-up, the graft and the tube remained stable. Our report suggests that corneal patch graft fixation to the sclera by means of tissue adhesive, without closing the conjunctiva, can be considered as an effective alternative surgical approach for managing exposed glaucoma drainage tube, accompanied by adjacent conjunctiva tissue deficiency. How to cite this article: Berezina TL, Fechtner RD, Cohen A, Kim EE, Chu DS. New Technique of Exposed Glaucoma Drainage Tube Repair: Report of a Case. J Curr Glaucoma Pract 2015;9(2):62-64.

Dose to the contralateral breast: a comparison of two techniques using the enhanced dynamic wedge versus a standard wedge.

PubMed

Warlick, W B; O'Rear, J H; Earley, L; Moeller, J H; Gaffney, D K; Leavitt, D D

1997-01-01

The dose to the contralateral breast has been associated with an increased risk of developing a second breast malignancy. Varying techniques have been devised and described in the literature to minimize this dose. Metal beam modifiers such as standard wedges are used to improve the dose distribution in the treated breast, but unfortunately introduce an increased scatter dose outside the treatment field, in particular to the contralateral breast. The enhanced dynamic wedge is a means of remote wedging created by independently moving one collimator jaw through the treatment field during dose delivery. This study is an analysis of differing doses to the contralateral breast using two common clinical set-up techniques with the enhanced dynamic wedge versus the standard metal wedge. A tissue equivalent block (solid water), modeled to represent a typical breast outline, was designed as an insert in a Rando phantom to simulate a standard patient being treated for breast conservation. Tissue equivalent material was then used to complete the natural contour of the breast and to reproduce appropriate build-up and internal scatter. Thermoluminescent dosimeter (TLD) rods were placed at predetermined distances from the geometric beam's edge to measure the dose to the contralateral breast. A total of 35 locations were used with five TLDs in each location to verify the accuracy of the measured dose. The radiation techniques used were an isocentric set-up with co-planar, non divergent posterior borders and an isocentric set-up with a half beam block technique utilizing the asymmetric collimator jaw. Each technique used compensating wedges to optimize the dose distribution. A comparison of the dose to the contralateral breast was then made with the enhanced dynamic wedge vs. the standard metal wedge. The measurements revealed a significant reduction in the contralateral breast dose with the enhanced dynamic wedge compared to the standard metal wedge in both set-up techniques. The dose was measured at varying distances from the geometric field edge, ranging from 2 to 8 cm. The average dose with the enhanced dynamic wedge was 2.7-2.8%. The average dose with the standard wedge was 4.0-4.7%. Thermoluminescent dosimeter measurements suggest an increase in both scattered electrons and photons with metal wedges. The enhanced dynamic wedge is a practical clinical advance which improves the dose distribution in patients undergoing breast conservation while at the same time minimizing dose to the contralateral breast, thereby reducing the potential carcinogenic effects.

"Facilitated" amino acid transport is upregulated in brain tumors.

PubMed

Miyagawa, T; Oku, T; Uehara, H; Desai, R; Beattie, B; Tjuvajev, J; Blasberg, R

1998-05-01

The goal of this study was to determine the magnitude of "facilitated" amino acid transport across tumor and brain capillaries and to evaluate whether amino acid transporter expression is "upregulated" in tumor vessels compared to capillaries in contralateral brain tissue. Aminocyclopentane carboxylic acid (ACPC), a non-metabolized [14C]-labeled amino acid, and a reference molecule for passive vascular permeability, [67Ga]-gallium-diethylenetriaminepentaacetic acid (Ga-DTPA), were used in these studies. Two experimental rat gliomas were studied (C6 and RG2). Brain tissue was rapidly processed for double label quantitative autoradiography 10 minutes after intravenous injection of ACPC and Ga-DTPA. Parametric images of blood-to-brain transport (K1ACPC and K1Ga-DTPA, microL/min/g) produced from the autoradiograms and the histology were obtained from the same tissue section. These three images were registered in an image array processor; regions of interest in tumor and contralateral brain were defined on morphologic criteria (histology) and were transferred to the autoradiographic images to obtain mean values. The facilitated component of ACPC transport (deltaK1ACPC) was calculated from the K1ACPC and K1Ga-DTPA data, and paired comparisons between tumor and contralateral brain were performed. ACPC flux, K1ACPC, across normal brain capillaries (22.6 +/- 8.1 microL/g/min) was >200-fold greater than that of Ga-DTPA (0.09 +/- 0.04 microL/g/min), and this difference was largely (approximately 90%) due to facilitated ACPC transport. Substantially higher K1ACPC values compared to corresponding K1DTPA values were also measured in C6 and RG2 gliomas. The deltaK1ACPC values for C6 glioma were more than twice that of contralateral brain cortex. K1ACPC and deltaK1ACPC values for RG2 gliomas was not significantly higher than that of contralateral cortex, although a approximately 2-fold difference in facilitated transport is obtained after normalization for differences in capillary surface area between RG2 tumors and contralateral cortex. K1ACPC, deltaK1ACPC, and K DTPA were directly related to tumor cell density, were higher in regions of "impending" necrosis, and the tumor/contralateral brain ACPC radio-activity ratios (0 to 10 minutes) were very similar to that obtained with 0 to 60 minutes experiments. These results indicate that facilitated transport of ACPC is upregulated across C6 and RG2 glioma capillaries, and that tumors can induce upregulation of amino acid transporter expression in their supporting vasculature. They also suggest that early imaging (e.g., 0 to 20 minutes) with radiolabeled amino acids in a clinical setting may be optimal for defining brain tumors.

Effects of slow repetitive transcranial magnetic stimulation in patients with corticobasal syndrome.

PubMed

Civardi, Carlo; Pisano, Fabrizio; Delconte, Carmen; Collini, Alessandra; Monaco, Francesco

2015-06-01

Corticobasal syndrome is characterized by asymmetric cortical sensorimotor dysfunction and parkinsonism; an altered cortical excitability has been reported. We explored with transcranial magnetic stimulation the motor cortical excitability in corticobasal syndrome, and the effects of slow repetitive transcranial magnetic stimulation. With transcranial magnetic stimulation, we studied two corticobasal syndrome patients. We determined bilaterally from the first dorsal interosseous muscle: relaxed threshold, and contralateral and ipsilateral silent period. We also evaluated the contralateral silent period after active/sham slow repetitive transcranial magnetic stimulation on the most affected side. At T0 the silent period was bilaterally short. On the most affected side, active slow repetitive transcranial magnetic stimulation induced a short lasting prolongation of the contralateral silent period. In corticobasal syndrome, transcranial magnetic stimulation showed a reduction cortical inhibitory phenomenon potentially reversed transiently by slow repetitive transcranial magnetic stimulation.

The Coordinated Noninvasive Studies (CNS) Project. Phase 1

DTIC Science & Technology

1991-12-01

may reveal functional asymmetries that represent the influence of two factors: 1) the "contralateral effect ," based on the side -of-space source of...asymmetries, where processing on that side of the CNS opposite the side of input is favored, and 2) an effect based J.L. Lauter [CNS Project/AFOSR 88-0352...extent that these exist over and above sidedness bias as well as side -of-space asymmetries -- since in these experiments, contralateral effects are

Radiographic Evaluation of Ankle Joint Stability After Calcaneofibular Ligament Elevation During Open Reduction and Internal Fixation of Calcaneus Fracture.

PubMed

Wang, Chien-Shun; Tzeng, Yun-Hsuan; Lin, Chun-Cheng; Huang, Ching-Kuei; Chang, Ming-Chau; Chiang, Chao-Ching

2016-09-01

The aim of this prospective study was to evaluate the influence of sectioning the calcaneofibular ligament (CFL) during an extensile lateral approach during open reduction and internal fixation (ORIF) of calcaneal fractures on ankle joint stability. Forty-two patients with calcaneal fractures that received ORIF were included. Talar tilt stress and anterior drawer radiographs were performed on the operative and contralateral ankles 6 months postoperatively. The average degree of talar tilt on stress radiographs was 3.4 degrees (range, 0-12 degrees) on the operative side and 3.2 degrees (range, 0-14 degrees) on the contralateral side. The mean anterior drawer on stress radiographs of the CFL incised ankle was 6.1 mm (range, 2.4-11.8 mm) and on the contralateral ankle was 5.7 mm (range, 2.6-8.6 mm). There was no statistically significant difference of talar tilt and anterior drawer between the CFL incised side and the contralateral side (P = .658 and .302, respectively). The results suggest that sectioning of the CFL without any repair during ORIF of a calcaneal fracture does not have a negative effect on stability of the ankle. Repair of the CFL is, thus, probably not necessary following extended lateral approach for ORIF of calcaneal fractures. Level II, comparative study. © The Author(s) 2016.

The effects of ipsilateral, contralateral, and bilateral broadband noise on the mid-level hump in intensity discriminationa)

PubMed Central

Roverud, Elin; Strickland, Elizabeth A.

2015-01-01

Previous psychoacoustical and physiological studies indicate that the medial olivocochlear reflex (MOCR), a bilateral, sound-evoked reflex, may lead to improved sound intensity discrimination in background noise. The MOCR can decrease the range of basilar-membrane compression and can counteract effects of neural adaptation from background noise. However, the contribution of these processes to intensity discrimination is not well understood. This study examined the effect of ipsilateral, contralateral, and bilateral noise on the “mid-level hump.” The mid-level hump refers to intensity discrimination Weber fractions (WFs) measured for short-duration, high-frequency tones which are poorer at mid levels than at lower or higher levels. The mid-level hump WFs may reflect a limitation due to basilar-membrane compression, and thus may be decreased by the MOCR. The noise was either short (50 ms) or long (150 ms), with the long noise intended to elicit the sluggish MOCR. For a tone in quiet, mid-level hump WFs improved with ipsilateral noise for most listeners, but not with contralateral noise. For a tone in ipsilateral noise, WFs improved with contralateral noise for most listeners, but only when both noises were long. These results are consistent with MOCR-induced WF improvements, possibly via decreases in effects of compression and neural adaptation. PMID:26627798

Unique cortical physiology associated with ipsilateral hand movements and neuroprosthetic implications.

PubMed

Wisneski, Kimberly J; Anderson, Nicholas; Schalk, Gerwin; Smyth, Matt; Moran, Daniel; Leuthardt, Eric C

2008-12-01

Brain computer interfaces (BCIs) offer little direct benefit to patients with hemispheric stroke because current platforms rely on signals derived from the contralateral motor cortex (the same region injured by the stroke). For BCIs to assist hemiparetic patients, the implant must use unaffected cortex ipsilateral to the affected limb. This requires the identification of distinct electrophysiological features from the motor cortex associated with ipsilateral hand movements. In this study we studied 6 patients undergoing temporary placement of intracranial electrode arrays. Electrocorticographic (ECoG) signals were recorded while the subjects engaged in specific ipsilateral or contralateral hand motor tasks. Spectral changes were identified with regards to frequency, location, and timing. Ipsilateral hand movements were associated with electrophysiological changes that occur in lower frequency spectra, at distinct anatomic locations, and earlier than changes associated with contralateral hand movements. In a subset of 3 patients, features specific to ipsilateral and contralateral hand movements were used to control a cursor on a screen in real time. In ipsilateral derived control this was optimal with lower frequency spectra. There are distinctive cortical electrophysiological features associated with ipsilateral movements which can be used for device control. These findings have implications for patients with hemispheric stroke because they offer a potential methodology for which a single hemisphere can be used to enhance the function of a stroke induced hemiparesis.

Probing the Effects and Mechanisms of Electroacupuncture at Ipsilateral or Contralateral ST36-ST37 Acupoints on CFA-induced Inflammatory Pain.

PubMed

Lu, Kung-Wen; Hsu, Chao-Kuei; Hsieh, Ching-Liang; Yang, Jun; Lin, Yi-Wen

2016-02-24

Transient receptor potential vanilloid 1 (TRPV1) and associated signaling pathways have been reported to be increased in inflammatory pain signaling. There are accumulating evidences surrounding the therapeutic effect of electroacupuncture (EA). EA can reliably attenuate the increase of TRPV1 in mouse inflammatory pain models with unclear signaling mechanisms. Moreover, the difference in the clinical therapeutic effects between using the contralateral and ipsilateral acupoints has been rarely studied. We found that inflammatory pain, which was induced by injecting the complete Freund's adjuvant (CFA), (2.14 ± 0.1, p < 0.05, n = 8) can be alleviated after EA treatment at either ipsilateral (3.91 ± 0.21, p < 0.05, n = 8) or contralateral acupoints (3.79 ± 0.25, p < 0.05, n = 8). EA may also reduce nociceptive Nav sodium currents in dorsal root ganglion (DRG) neurons. The expression of TRPV1 and associated signaling pathways notably increased after the CFA injection; this expression can be further attenuated significantly in EA treatment. TRPV1 and associated signaling pathways can be prevented in TRPV1 knockout mice, suggesting that TRPV1 knockout mice are resistant to inflammatory pain. Through this study, we have increased the understanding of the mechanism that both ipsilateral and contralateral EA might alter TRPV1 and associated signaling pathways to reduce inflammatory pain.

Auditory enhancement of increments in spectral amplitude stems from more than one source.

PubMed

Carcagno, Samuele; Semal, Catherine; Demany, Laurent

2012-10-01

A component of a test sound consisting of simultaneous pure tones perceptually "pops out" if the test sound is preceded by a copy of itself with that component attenuated. Although this "enhancement" effect was initially thought to be purely monaural, it is also observable when the test sound and the precursor sound are presented contralaterally (i.e., to opposite ears). In experiment 1, we assessed the magnitude of ipsilateral and contralateral enhancement as a function of the time interval between the precursor and test sounds (10, 100, or 600 ms). The test sound, randomly transposed in frequency from trial to trial, was followed by a probe tone, either matched or mismatched in frequency to the test sound component which was the target of enhancement. Listeners' ability to discriminate matched probes from mismatched probes was taken as an index of enhancement magnitude. The results showed that enhancement decays more rapidly for ipsilateral than for contralateral precursors, suggesting that ipsilateral enhancement and contralateral enhancement stem from at least partly different sources. It could be hypothesized that, in experiment 1, contralateral precursors were effective only because they provided attentional cues about the target tone frequency. In experiment 2, this hypothesis was tested by presenting the probe tone before the precursor sound rather than after the test sound. Although the probe tone was then serving as a frequency cue, contralateral precursors were again found to produce enhancement. This indicates that contralateral enhancement cannot be explained by cuing alone and is a genuine sensory phenomenon.

The medial olivocochlear reflex in children during active listening

PubMed Central

Smith, Spencer B.; Cone, Barbara

2015-01-01

Objective To determine if active listening modulates the strength of the medial olivocochlear (MOC) reflex in children. Design Click-evoked otoacoustic emissions (CEOAEs) were recorded from the right ear in quiet and in four test conditions: one with contralateral broadband noise (BBN) only, and three with active listening tasks wherein attention was directed to speech embedded in contralateral BBN. Study sample Fifteen typically-developing children (ranging in age from 8 to 14 years) with normal hearing. Results CEOAE levels were reduced in every condition with contralateral acoustic stimulus (CAS) when compared to preceding quiet conditions. There was an additional systematic decrease in CEOAE level with increased listening task difficulty, although this effect was very small. These CEOAE level differences were most apparent in the 8–18 ms region after click onset. Conclusions Active listening may change the strength of the MOC reflex in children, although the effects reported here are very subtle. Further studies are needed to verify that task difficulty modulates the activity of the MOC reflex in children. PMID:25735203

Assessing Hand Muscle Structural Modifications in Chronic Stroke.

PubMed

Zong, Ya; Shin, Henry H; Wang, Ying-Chih; Li, Sheng; Zhou, Ping; Li, Xiaoyan

2018-01-01

The purpose of the study is to assess poststroke muscle structural alterations by examining muscular electrical conductivity and inherent electrophysiological properties. In particular, muscle impedance and compound muscle action potentials (CMAP) were measured from the hypothenar muscle bilaterally using the electrical impedance myography and the electrophysiological techniques, respectively. Significant changes of muscle impedance were observed in the paretic muscle compared with the contralateral side (resistance: paretic: 27.54 ± 0.97 Ω, contralateral: 25.46 ± 0.91 Ω, p  < 0.05; phase angle: paretic: 8.81 ± 0.61°, contralateral: 10.79 ± 0.69°, p  < 0.05). In addition, impedance changes correlated moderately with the CMAP amplitude in the paretic hand (phase angle: r  = 0.66, p  < 0.05; reactance: r  = 0.58, p  < 0.05). The study discloses significant muscle rearrangements as a result of fiber loss or atrophy, fat infiltration or impaired membrane integrity in chronic stroke.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, H; Cape Breton Cancer Centre, Sydney, NS

Purpose: To perform the comparison of dose distributions and dosevolume- histograms generated by VMAT and conventional field-in-field technique for left-sided breast and chestwall cancers; to determine whether VMAT offers more dosimetric benefits than does the field-in-field technique. Methods: All VMAT and field-in-filed plans were produced in Eclipse(version 10). Five plans were generated for left-sided breast and leftsided chestwall with supraclavicular nodes, respectively. A clockwise arc (CW) and a counter-clockwise arc (CCW) were used with start and stop angles being 310o±10o and 140o±10o. Collimator angles were 30o for CW and 330o for CCW. The conformity index (CI) is the ratio ofmore » V95% over PTV. The homogeneity index (HI) is the ratio of the difference between D2% and D98% over the prescribed dose. The V5, as an indicator of low dose bath to organs-at-risk, was used for ipsilateral lung, heart, contralateral lung, and contralateral breast. The V20, as an indicator of radiation pneumonitis, was used for ipsilateral lung. Results: Breast/chestwall VMAT delivers much higher low dose bath to ipsilateral lung, contralateral lung and contralateral breast/chestwall for both intact breast and chestwall with nodes. V5 for heart is increased in VMAT plans. V20 for ipsilateral lung is lower in VMAT plans. PTV coverage is similar for both techniques. For one particular chestwall patient with supraclavicular and internal mammary nodes, VMAT offers superior dose coverage of PTVs with slightly more low-dose-wash to heart, contralateral lung and contralateral breast. Conclusion: This study indicates that there is generally no benefit using VMAT for left-sided intact breast, due to large low-dose-bath (5Gy) to normal tissues with insignificant improvement in PTV coverage. Dosimetric benefits will be seen in VMAT plans for some chestwall patients with large size, and/or internal mammary nodes, etc. Whether a chestwall patient is treated with VMAT should be carefully analyzed on an individual basis.« less

Is it necessary to use the entire root as a donor when transferring contralateral C7 nerve to repair median nerve?

PubMed

Gao, Kai-Ming; Lao, Jie; Guan, Wen-Jie; Hu, Jing-Jing

2018-01-01

If a partial contralateral C 7 nerve is transferred to a recipient injured nerve, results are not satisfactory. However, if an entire contralateral C 7 nerve is used to repair two nerves, both recipient nerves show good recovery. These findings seem contradictory, as the above two methods use the same donor nerve, only the cutting method of the contralateral C 7 nerve is different. To verify whether this can actually result in different repair effects, we divided rats with right total brachial plexus injury into three groups. In the entire root group, the entire contralateral C 7 root was transected and transferred to the median nerve of the affected limb. In the posterior division group, only the posterior division of the contralateral C 7 root was transected and transferred to the median nerve. In the entire root + posterior division group, the entire contralateral C 7 root was transected but only the posterior division was transferred to the median nerve. After neurectomy, the median nerve was repaired on the affected side in the three groups. At 8, 12, and 16 weeks postoperatively, electrophysiological examination showed that maximum amplitude, latency, muscle tetanic contraction force, and muscle fiber cross-sectional area of the flexor digitorum superficialis muscle were significantly better in the entire root and entire root + posterior division groups than in the posterior division group. No significant difference was found between the entire root and entire root + posterior division groups. Counts of myelinated axons in the median nerve were greater in the entire root group than in the entire root + posterior division group, which were greater than the posterior division group. We conclude that for the same recipient nerve, harvesting of the entire contralateral C 7 root achieved significantly better recovery than partial harvesting, even if only part of the entire root was used for transfer. This result indicates that the entire root should be used as a donor when transferring contralateral C 7 nerve.

Is it necessary to use the entire root as a donor when transferring contralateral C7 nerve to repair median nerve?

PubMed Central

Gao, Kai-ming; Lao, Jie; Guan, Wen-jie; Hu, Jing-jing

2018-01-01

If a partial contralateral C7 nerve is transferred to a recipient injured nerve, results are not satisfactory. However, if an entire contralateral C7 nerve is used to repair two nerves, both recipient nerves show good recovery. These findings seem contradictory, as the above two methods use the same donor nerve, only the cutting method of the contralateral C7 nerve is different. To verify whether this can actually result in different repair effects, we divided rats with right total brachial plexus injury into three groups. In the entire root group, the entire contralateral C7 root was transected and transferred to the median nerve of the affected limb. In the posterior division group, only the posterior division of the contralateral C7 root was transected and transferred to the median nerve. In the entire root + posterior division group, the entire contralateral C7 root was transected but only the posterior division was transferred to the median nerve. After neurectomy, the median nerve was repaired on the affected side in the three groups. At 8, 12, and 16 weeks postoperatively, electrophysiological examination showed that maximum amplitude, latency, muscle tetanic contraction force, and muscle fiber cross-sectional area of the flexor digitorum superficialis muscle were significantly better in the entire root and entire root + posterior division groups than in the posterior division group. No significant difference was found between the entire root and entire root + posterior division groups. Counts of myelinated axons in the median nerve were greater in the entire root group than in the entire root + posterior division group, which were greater than the posterior division group. We conclude that for the same recipient nerve, harvesting of the entire contralateral C7 root achieved significantly better recovery than partial harvesting, even if only part of the entire root was used for transfer. This result indicates that the entire root should be used as a donor when transferring contralateral C7 nerve. PMID:29451212

In vivo imaging of human burn injuries with polarization-sensitive optical coherence tomography

NASA Astrophysics Data System (ADS)

Kim, Ki Hean; Pierce, Mark C.; Maguluri, Gopi; Park, B. Hyle; Yoon, Sang June; Lydon, Martha; Sheridan, Robert; de Boer, Johannes F.

2012-06-01

The accurate determination of burn depth is critical in the clinical management of burn wounds. Polarization-sensitive optical coherence tomography (PS-OCT) has been proposed as a potentially non-invasive method for determining burn depth by measuring thermally induced changes in the structure and birefringence of skin, and has been investigated in pre-clinical burn studies with animal models and ex vivo human skin. In this study, we applied PS-OCT to the in-vivo imaging of two pediatric burn patients. Deep and superficial burned skins along with contralateral controls were imaged in 3D. The imaging size was 8 mm×6 mm×2 mm in width, length, and depth in the air respectively, and the imaging time was approximately 6 s per volume. Superficially burned skins exhibited the same layered structure as the contralateral controls, but more visible vasculature and reduced birefringence compared to the contralateral controls. In contrast, a deeply burned skin showed loss of the layered structure, almost absent vasculature, and smaller birefringence compared to superficial burns. This study suggested the vasculature and birefringence as parameters for characterizing burn wounds.

Is it sufficient to repeat LINEAR accelerator stereotactic radiosurgery in choroidal melanoma?

PubMed

Furdova, A; Horkovicova, K; Justusova, P; Sramka, M

One day session LINAC based stereotactic radiosurgery (SRS) at LINAC accelerator is a method of "conservative" attitude to treat the intraocular malignant uveal melanoma. We used model Clinac 600 C/D Varian (system Aria, planning system Corvus version 6.2 verification IMRT OmniPro) with 6 MeV X by rigid immobilization of the eye to the Leibinger frame. The stereotactic treatment planning after fusion of CT and MRI was optimized according to the critical structures (lens, optic nerve, also lens and optic nerve at the contralateral side, chiasm). The first plan was compared and the best plan was applied for therapy at C LINAC accelerator. The planned therapeutic dose was 35.0 Gy by 99 % of DVH (dose volume histogram). In our clinical study in the group of 125 patients with posterior uveal melanoma treated with SRS, in 2 patients (1.6 %) was repeated SRS indicated. Patient age of the whole group ranged from 25 to 81 years with a median of 54 TD was 35.0 Gy. In 2 patients after 5 year interval after stereotactic radiosurgery for uveal melanoma stage T1, the tumor volume increased to 50 % of the primary tumor volume and repeated SRS was necessary. To find out the changes in melanoma characteristics after SRS in long term interval after irradiation is necessary to follow up the patient by an ophthalmologist regularly. One step LINAC based stereotactic radiosurgery with a single dose 35.0 Gy is one of treatment options to treat T1 to T3 stage posterior uveal melanoma and to preserve the eye globe. In some cases it is possible to repeat the SRS after more than 5 year interval (Fig. 8, Ref. 23).

A Bioengineering Approach to Myopia Control Tested in a Guinea Pig Model

PubMed Central

Garcia, Mariana B.; Jha, Amit K.; Healy, Kevin E.; Wildsoet, Christine F.

2017-01-01

Purpose To investigate the biocompatibility of an injectable hydrogel and its ability to control myopia progression in guinea pigs. Methods The study used a hydrogel synthesized from acrylated hyaluronic acid with a conjugated cell-binding peptide and enzymatically degradable crosslinker. Seven-day-old guinea pigs were first form deprived (FD) with diffusers for 1 week. One group was kept as an FD-only control; two groups received a sub-Tenon's capsule injection of either hydrogel or buffer (sham surgery) at the posterior pole of the eye. Form deprivation treatments were then continued for 3 additional weeks. Treatment effects were evaluated in terms of ocular axial length and refractive error. Safety was evaluated via intraocular pressure (IOP), visual acuity, flash electroretinograms (ERG), and histology. Results Both hydrogel and sham surgery groups showed significantly reduced axial elongation and myopia progression compared to the FD-only group. For axial lengths, net changes in interocular difference (treated minus control) were 0.04 ± 0.06, 0.02 ± 0.09, and 0.24 ± 0.08 mm for hydrogel, sham, and FD-only groups, respectively (P = 0.0006). Intraocular pressures, visual acuities, and ERGs of treated eyes were not significantly different from contralateral controls. Extensive cell migration into the implants was evident. Both surgery groups showed noticeable Tenon's capsule thickening. Conclusions Sub-Tenon's capsule injections of both hydrogel and buffer inhibited myopia progression, with no adverse effects on ocular health. The latter unexpected effect warrants further investigation as a potential novel myopia control therapy. That the hydrogel implant supported significant cell infiltration offers further proof of its biocompatibility, with potential application as a tool for drug and cell delivery. PMID:28358959

Analysis of linear electrode array EMG for assessment of hemiparetic biceps brachii muscles.

PubMed

Yao, Bo; Zhang, Xu; Li, Sheng; Li, Xiaoyan; Chen, Xiang; Klein, Cliff S; Zhou, Ping

2015-01-01

This study presents a frequency analysis of surface electromyogram (EMG) signals acquired by a linear electrode array from the biceps brachii muscles bilaterally in 14 hemiparetic stroke subjects. For different levels of isometric contraction ranging from 10 to 80% of the maximum voluntary contraction (MVC), the power spectra of 19 bipolar surface EMG channels arranged proximally to distally along the muscle fibers were examined in both paretic and contralateral muscles. It was found that across all stroke subjects, the median frequency (MF) and the mean power frequency (MPF), averaged from different surface EMG channels, were significantly smaller in the paretic muscle compared to the contralateral muscle at each of the matched percent MVC contractions. The muscle fiber conduction velocity (MFCV) was significantly slower in the paretic muscle than in the contralateral muscle. No significant correlation between the averaged MF, MPF, or MFCV vs. torque was found in both paretic and contralateral muscles. However, there was a significant positive correlation between the global MFCV and MF. Examination of individual EMG channels showed that electrodes closest to the estimated muscle innervation zones produced surface EMG signals with significantly higher MF and MPF than more proximal or distal locations in both paretic and contralateral sides. These findings suggest complex central and peripheral neuromuscular alterations (such as selective loss of large motor units, disordered control of motor units, increased motor unit synchronization, and atrophy of muscle fibers, etc.) which can collectively influence the surface EMG signals. The frequency difference with regard to the innervation zone also confirms the relevance of electrode position in surface EMG analysis.

Decreased oxygen saturation in asymmetrically prominent cortical veins in patients with cerebral ischemic stroke.

PubMed

Xia, Shuang; Utriainen, David; Tang, Jin; Kou, Zhifeng; Zheng, Gang; Wang, Xuesong; Shen, Wen; Haacke, E Mark; Lu, Guangming

2014-12-01

Decreased oxygen saturation in asymmetrically prominent cortical veins (APCV) seen in ischemic stroke has been hypothesized to correlate with an increase of de-oxygenated hemoglobin. Our goal is to quantify magnetic susceptibility to define APCV by establishing a cutoff above which the deoxyhemoglobin levels are considered abnormal. A retrospective study was conducted on 26 patients with acute ischemic stroke in one cerebral hemisphere that exhibited APCV with 30 age- and sex-matched healthy controls. Quantitative susceptibility mapping (QSM) was used to calculate the magnetic susceptibility of the cortical veins. A paired t-test was used to compare the susceptibility of the cortical veins in the left and right hemispheres for healthy controls as well as in the contralateral hemisphere for stroke patients with APCV. The change in oxygen saturation in the APCV relative to the contralateral side was calculated after thresholding the susceptibility using the mean plus two standard deviations of the contralateral side for each individual. The thresholded susceptibility value of the APCVs in the stroke hemisphere was 254±48 ppb which was significantly higher (p<0.05) than that in the contralateral hemisphere (123±12 ppb) and in healthy controls (125±8 ppb). There was a decrease of oxygen saturation in the APCV ranging from 16% to 44% relative to the veins of the contralateral hemisphere. In conclusion, APCV seen in SWI correspond to reduced levels of oxygen saturation and these abnormal veins can be identified using a susceptibility threshold on the QSM data. Copyright © 2014 Elsevier Inc. All rights reserved.

Anterior transarticular C1-C2 fixation with contralateral screw insertion: a report of two cases and technical note.

PubMed

Lvov, Ivan; Grin, Andrey; Kaykov, Aleksandr; Smirnov, Vladimir; Krylov, Vladimir

2017-08-08

Anterior transarticular fixation of the C1-C2 vertebrae is a well-known technique that involves screw insertion through the body of the C2 vertebra into the lateral masses of the atlas through an anterior transcervical approach. Meanwhile, contralateral screw insertion has been previously described only in anatomical studies. We describe two case reports of the clinical application of this new technique. In Case 1, the patient was diagnosed with an unstable C1 fracture. The clinical features of the case did not allow for any type of posterior atlantoaxial fusion, Halo immobilization, or routine anterior fixation using the Reindl and Koller techniques. The possible manner of screw insertion into the anterior third of the right lateral mass was via a contralateral trajectory, which was performed in this case. Case 2 involved a patient with neglected posteriorly dislocated dens fracture who could not lie in the prone position due to concomitant cardiac pathology. Reduction of atlantoaxial dislocation was insufficient, even after scar tissue resection at the fracture, while transdental fusion was not possible. Considering the success of the previous case, atlantoaxial fixation was performed through the small approach, using the Reindl technique and contralateral screw insertion. These two cases demonstrate the potential of anterior transarticular fixation of C1-C2 vertebrae in cases where posterior atlantoaxial fusion is not achievable. This type of fixation can be performed through a single approach if one screw is inserted using the Reindl technique and another is inserted via a contralateral trajectory.

Bilateral Activity-Dependent Interactions in the Developing Corticospinal System

PubMed Central

Friel, Kathleen M.; Martin, John H.

2009-01-01

Activity-dependent competition between the corticospinal (CS) systems in each hemisphere drives postnatal development of motor skills and stable CS tract connections with contralateral spinal motor circuits. Unilateral restriction of motor cortex (M1) activity during an early postnatal critical period impairs contralateral visually guided movements later in development and in maturity. Silenced M1 develops aberrant connections with the contralateral spinal cord whereas the initially active M1, in the other hemisphere, develops bilateral connections. In this study, we determined whether the aberrant pattern of CS tract terminations and motor impairments produced by early postnatal M1 activity restriction could be abrogated by reducing activity-dependent synaptic competition from the initially active M1 later in development. We first inactivated M1 unilaterally between postnatal weeks 5–7. We next inactivated M1 on the other side from weeks 7–11 (alternate inactivation), to reduce the competitive advantage that this side may have over the initially inactivated side. Alternate inactivation redirected aberrant contralateral CS tract terminations from the initially silenced M1 to their normal spinal territories and reduced the density of aberrant ipsilateral terminations from the initially active side. Normal movement endpoint control during visually guided locomotion was fully restored. This reorganization of CS terminals reveals an unsuspected late plasticity after the critical period for establishing the pattern of CS terminations in the spinal cord. Our findings show that robust bilateral interactions between the developing CS systems on each side are important for achieving balance between contralateral and ipsilateral CS tract connections and visuomotor control. PMID:17928450

Motor activation in patients with Pantothenate-Kinase Associated Neurodegeneration: a functional magnetic resonance imaging study.

PubMed

Stoeter, P; Rodriguez-Raecke, R; Vilchez, C; Perez-Then, E; Speckter, H; Oviedo, J; Roa-Sanchez, P

2012-11-01

In a variety of dystonias, functional magnetic resonance imaging has shown deviations of cortical and basal ganglia activations within the motor network, which might cause the movement disturbances. Because these investigations have never been performed in secondary dystonia due to Pantothenate-Kinase Associated Neurodegeneration, we report our results in a small group of such patients from the Dominican Republic. Functional magnetic resonance imaging was carried out in 7 patients with a genetically confirmed mutation of the PANK2 gene and a non-affected control group (matched pairs) using an event-related motor activation paradigm (hand movements). Compared to the control group (p ≤ 0.01), patients showed a larger amount of activated voxels starting in the contralateral cerebellum and contralateral premotor cortex 2 s before the actual hand movement. Whereas these "hyperactivations" gradually diminished over time, activations in the contralateral primary motor cortex and the supplementary motor area peaked during the next second and those of the contralateral putamen at the time of the actual hand movement. In a multiple regression analysis, all these areas correlated positively with the degree of dystonia of the contralateral arm as judged by the Burke-Fahn-Marsden-scale (p ≤ 0.001). As in other forms of dystonia, the increased activations of the motor system found in our patients could be related to the origin of the dystonic movements. Because in this condition the primary lesion affects the pallidum, a defect of the feed-back control mechanism between basal ganglia and cortex might be the responsible factor. © 2012 Elsevier Ltd. All rights reserved.

Protective effect of sildenafil citrate on contralateral testis injury after unilateral testicular torsion/detorsion.

PubMed

Yíldíz, Hamit; Durmus, Ali Said; Simşek, Halil; Yaman, Mine

2011-01-01

This study was designed to investigate prevention of contralateral testicular injury with sildenafil citrate after unilateral testicular torsion/detorsion. Thirty-seven adult male rats were divided into four groups: sham operated (group 1, n = 7), torsion/detorsion + saline (group 2, n = 10), torsion/detorsion + 0.7 mg of sildenafil citrate (group 3, n = 10) and torsion/detorsion + 1.4 mg of sildenafil citrate (group 4, n = 10). Unilateral testicular torsion was created by rotating the right testis 720º in a clockwise direction for 2 h in other groups, except for group 1, which was served as sham group. After torsion (2 h) and detorsion (2 h) periods, rats were killed. The level of reduced glutathion (GSH) (p < 0.05) and the activities of catalase (p < 0.01) and glutathione peroxidase (p < 0.05) in the contralateral testis from group 2 were significantly lower and nitric oxide (NO) (p < 0.05) level in the contralateral testis were significantly higher than those of group 1. Administration of low-dose sildenafil citrate (group 3) prevented the increases in malondialdehyde and NO levels and decreases in glutathione peroxidase activities and GSH values induced by testicular torsion. However, administration of high-dose sildenafil citrate (group 4) had no effect on these testicular parameters (p > 0.05). Histopathological changes were detected in groups 2, 3 and 4. These results suggest that biochemically and histologically torsion/detorsion injury occurs in the contralateral testis following 2-h torsion and 2-h detorsion and that administration of low-dose sildenafil citrate before detorsion prevents ischemia/reperfusion cellular damage in testicular tissue.

Objective assessment of the compensatory effect of clinical hind limb lameness in horses: 37 cases (2011-2014).

PubMed

Maliye, Sylvia; Marshall, John F

2016-10-15

OBJECTIVE To characterize and describe the compensatory load redistribution that results from unilateral hind limb lameness in horses. DESIGN Retrospective case series. ANIMALS 37 client-owned horses. PROCEDURES Medical records were reviewed to identify horses with unilateral hind limb lameness that responded positively (by objective assessment) to diagnostic local anesthesia during lameness evaluation and that were evaluated before and after diagnostic local anesthesia with an inertial sensor-based lameness diagnosis system. Horses were grouped as having hind limb lameness only, hind limb and ipsilateral forelimb lameness, or hind limb and contralateral forelimb lameness. Measures of head and pelvic movement asymmetry before (baseline) and after diagnostic local anesthesia were compared. The effect of group on baseline pelvic movement asymmetry variables was analyzed statistically. RESULTS Maximum pelvic height significantly decreased from the baseline value after diagnostic local anesthesia in each of the 3 lameness groups and in all horses combined. Minimum pelvic height significantly decreased after the procedure in all groups except the hind limb and contralateral forelimb lameness group. Head movement asymmetry was significantly decreased after diagnostic local anesthesia for horses with hind limb and ipsilateral forelimb lameness and for all horses combined, but not for those with hind limb lameness only or those with hind limb and contralateral forelimb lameness. CONCLUSIONS AND CLINICAL RELEVANCE Results supported that hind limb lameness can cause compensatory load redistribution evidenced as ipsilateral forelimb lameness. In this population of horses, contralateral forelimb lameness was not compensatory and likely reflected true lameness. Further studies are needed to investigate the source of the contralateral forelimb lameness in such horses.

Evaluation of anticollagen type I antibody titers in synovial fluid of both stifle joints and the left shoulder joint of dogs with unilateral cranial cruciate disease.

PubMed

de Bruin, Tanya; de Rooster, Hilde; van Bree, Henri; Cox, Eric

2007-03-01

To evaluate anticollagen type I antibodies in synovial fluid of the affected stifle joint, the contralateral stifle joint, and the left shoulder joint of dogs with unilateral cranial cruciate ligament (CrCL) rupture during an extended period of 12 to 18 months. 13 client-owned dogs with CrCL rupture and 2 sham-operated dogs. All dogs were examined and arthrocentesis of all 3 joints was performed every 6 months after surgery. Synovial fluid samples were tested for anticollagen type I antibodies by use of an ELISA. Dogs with partial CrCL rupture had higher antibody titers than dogs with complete rupture. Six of 13 dogs ruptured the contralateral CrCL during the study, whereby higher antibody titers were found for the stifle joints than for the shoulder joint. Seronegative dogs or dogs with extremely low antibody titers and 2 dogs with high antibody titers did not sustain a CrCL rupture in the contralateral stifle joint. In most dogs that had a CrCL rupture of the contralateral stifle joint, a distinct antibody titer gradient toward the stifle joints was detected, suggesting that there was a local inflammatory process in these joints. However, only a small number of sham-operated dogs were used to calculate the cutoff values used to determine the anticollagen type I antibody titers in these patients. Synovial fluid antibodies against collagen type I alone do not initiate CrCL rupture because not all dogs with high antibody titers sustained a CrCL rupture in the contralateral stifle joint.

Dose-dependent effect of mammographic breast density on the risk of contralateral breast cancer.

PubMed

Chowdhury, Marzana; Euhus, David; O'Donnell, Maureen; Onega, Tracy; Choudhary, Pankaj K; Biswas, Swati

2018-07-01

Increased mammographic breast density is a significant risk factor for breast cancer. It is not clear if it is also a risk factor for the development of contralateral breast cancer. The data were obtained from Breast Cancer Surveillance Consortium and included women diagnosed with invasive breast cancer or ductal carcinoma in situ between ages 18 and 88 and years 1995 and 2009. Each case of contralateral breast cancer was matched with three controls based on year of first breast cancer diagnosis, race, and length of follow-up. A total of 847 cases and 2541 controls were included. The risk factors included in the study were mammographic breast density, age of first breast cancer diagnosis, family history of breast cancer, anti-estrogen treatment, hormone replacement therapy, menopausal status, and estrogen receptor status, all from the time of first breast cancer diagnosis. Both univariate analysis and multivariate conditional logistic regression analysis were performed. In the final multivariate model, breast density, family history of breast cancer, and anti-estrogen treatment remained significant with p values less than 0.01. Increasing breast density had a dose-dependent effect on the risk of contralateral breast cancer. Relative to 'almost entirely fat' category of breast density, the adjusted odds ratios (and p values) in the multivariate analysis for 'scattered density,' 'heterogeneously dense,' and 'extremely dense' categories were 1.65 (0.036), 2.10 (0.002), and 2.32 (0.001), respectively. Breast density is an independent and significant risk factor for development of contralateral breast cancer. This risk factor should contribute to clinical decision making.

Manipulating the disengage operation of covert visual spatial attention.

PubMed

Danckert, J; Maruff, P

1997-05-01

Processes of covert visual spatial attention have been closely linked to the programming of saccadic eye movements. In particular, it has been hypothesized that the reduction in saccadic latency that occurs in the gap paradigm is due to the prior disengagement of covert visual spatial attention. This explanation has received considerable criticism. No study as yet as attempted to demonstrate a facilitation of the disengagement of attention from a covertly attended object. If such facilitation were possible, it would support the hypothesis that the predisengagement of covert attention is necessary for the generation of express saccades. In two experiments using covert orienting of visual attention tasks (COVAT), with a high probability that targets would appear contralateral to the cued location, we attempted to facilitate the disengagement of covert attention by extinguishing peripheral cues prior to the appearance of targets. We hypothesized that the gap between cue offset and target onset would facilitate disengagement of attention from a covertly attended object. For both experiments, responses to targets appearing after a gap were slower than were responses in the no-gap condition. These results suggest that the prior offset of a covertly attended object does not facilitate the disengagement of attention.

A case of loss of consciousness with contralateral acute subdural haematoma during awake craniotomy

PubMed Central

Kamata, Kotoe; Maruyama, Takashi; Nitta, Masayuki; Ozaki, Makoto; Muragaki, Yoshihiro; Okada, Yoshikazu

2014-01-01

We are reporting the case of a 56-year-old woman who developed loss of consciousness during awake craniotomy. A thin subdural haematoma in the contralateral side of the craniotomy was identified with intraoperative magnetic resonance imaging and subsequently removed. Our case indicates that contralateral acute subdural haematoma could be a cause of deterioration of the conscious level during awake craniotomy. PMID:25301378

Knee Kinematics and Joint Moments During Stair Negotiation in Participants With Anterior Cruciate Ligament Deficiency and Reconstruction: A Systematic Review and Meta-Analysis.

PubMed

Hajizadeh, Maryam; Hashemi Oskouei, Alireza; Ghalichi, Farzan; Sole, Gisela

2016-06-01

Biomechanical changes have been reported for patients with anterior cruciate ligament deficiency (ACLD) and anterior cruciate ligament (ACL reconstruction) (ACLR), likely due to loss of stability and changes in proprioception and neuromotor control. This review evaluated kinematics and kinetics of ACLD and ACLR knees, compared with those on the contralateral uninjured sides, as well as and those in asymptomatic controls during stair navigation. This is a systematic review and meta-analysis. Electronic database searches were conducted from their original available dates to January 2015. Studies that included participants with ACLD or ACLR and reported knee joint angles or moments during stair ascent or descent were included. Nine studies met the inclusion criteria, and the methodological quality of these was assessed with a modified Downs and Black checklist. Effect sizes for differences between injured leg and uninjured contralateral leg or controls were calculated, and meta-analyses were performed if two or more studies considered the same variable. Quality assessment showed an average (± standard deviation) of 70.3% ± 7.2%. Meta-analysis showed less knee flexion at initial contact for ACLR knees compared with that in contralateral knees during stair ascent, with a moderate effect size and minimal heterogeneity. Knees with ACLD showed less peak knee flexion compared with that on contralateral sides during stair ascent, with minimal heterogeneity. External knee flexion moments were lower for ACLR compared with those in controls and contralateral sides during ascent and descent, whereas these moments were decreased for the ACLD compared with controls only during ascent. Meta-analysis results exhibited moderate/high heterogeneity or small/trivial effect sizes. Differences for kinematics and kinetics for the ACL-injured knees indicate long-term compensatory and asymmetric movement patterns while ascending and descending stairs. Due to the heterogeneity as well as the small numbers of available studies, the consequences of these differences in terms of long-term function or posttraumatic osteoarthritis need further exploration. Copyright © 2016. Published by Elsevier Inc.

The temporal evolution of electromagnetic markers sensitive to the capacity limits of visual short-term memory.

PubMed

Mitchell, Daniel J; Cusack, Rhodri

2011-01-01

An electroencephalographic (EEG) marker of the limited contents of human visual short-term memory (VSTM) has previously been described. Termed contralateral delay activity, this consists of a sustained, posterior, negative potential that correlates with memory load and is greatest contralateral to the remembered hemifield. The current investigation replicates this finding and uses magnetoencephalography (MEG) to characterize its magnetic counterparts and their neural generators as they evolve throughout the memory delay. A parametric manipulation of memory load, within and beyond capacity limits, allows separation of signals that asymptote with behavioral VSTM performance from additional responses that contribute to a linear increase with set-size. Both EEG and MEG yielded bilateral signals that track the number of objects held in memory, and contralateral signals that are independent of memory load. In MEG, unlike EEG, the contralateral interaction between hemisphere and item load is much weaker, suggesting that bilateral and contralateral markers of memory load reflect distinct sources to which EEG and MEG are differentially sensitive. Nonetheless, source estimation allowed both the bilateral and the weaker contralateral capacity-limited responses to be localized, along with a load-independent contralateral signal. Sources of global and hemisphere-specific signals all localized to the posterior intraparietal sulcus during the early delay. However the bilateral load response peaked earlier and its generators shifted later in the delay. Therefore the hemifield-specific response may be more closely tied to memory maintenance while the global load response may be involved in initial processing of a limited number of attended objects, such as their individuation or consolidation into memory.

Interaural Phase and Level Difference Sensitivity in Low-Frequency Neurons in the Lateral Superior Olive

PubMed Central

Tollin, Daniel J.; Yin, Tom C. T.

2006-01-01

The lateral superior olive (LSO) is believed to encode differences in sound level at the two ears, a cue for azimuthal sound location. Most high-frequency-sensitive LSO neurons are binaural, receiving inputs from both ears. An inhibitory input from the contralateral ear, via the medial nucleus of the trapezoid body (MNTB), and excitatory input from the ipsilateral ear enable level differences to be encoded. However, the classical descriptions of low-frequency-sensitive neurons report primarily monaural cells with no contralateral inhibition. Anatomical and physiological evidence, however, shows that low-frequency LSO neurons receive low-frequency inhibitory input from ipsilateral MNTB, which in turn receives excitatory input from the contralateral cochlear nucleus and low-frequency excitatory input from the ipsilateral cochlear nucleus. Therefore, these neurons would be expected to be binaural with contralateral inhibition. Here, we re-examined binaural interaction in low-frequency (less than ~3 kHz) LSO neurons and phase locking in the MNTB. Phase locking to low-frequency tones in MNTB and ipsilaterally driven LSO neurons with frequency sensitivities < 1.2 kHz was enhanced relative to the auditory nerve. Moreover, most low-frequency LSO neurons exhibited contralateral inhibition: ipsilaterally driven responses were suppressed by raising the level of the contralateral stimulus; most neurons were sensitive to interaural time delays in pure tone and noise stimuli such that inhibition was nearly maximal when the stimuli were presented to the ears in-phase. The data demonstrate that low-frequency LSO neurons of cat are not monaural and can exhibit contralateral inhibition like their high-frequency counterparts. PMID:16291937

Imaging the Spatio-Temporal Dynamics of Supragranular Activity in the Rat Somatosensory Cortex in Response to Stimulation of the Paws

PubMed Central

Morales-Botello, M. L.; Aguilar, J.; Foffani, G.

2012-01-01

We employed voltage-sensitive dye (VSD) imaging to investigate the spatio-temporal dynamics of the responses of the supragranular somatosensory cortex to stimulation of the four paws in urethane-anesthetized rats. We obtained the following main results. (1) Stimulation of the contralateral forepaw evoked VSD responses with greater amplitude and smaller latency than stimulation of the contralateral hindpaw, and ipsilateral VSD responses had a lower amplitude and greater latency than contralateral responses. (2) While the contralateral stimulation initially activated only one focus, the ipsilateral stimulation initially activated two foci: one focus was typically medial to the focus activated by contralateral stimulation and was stereotaxically localized in the motor cortex; the other focus was typically posterior to the focus activated by contralateral stimulation and was stereotaxically localized in the somatosensory cortex. (3) Forepaw and hindpaw somatosensory stimuli activated large areas of the sensorimotor cortex, well beyond the forepaw and hindpaw somatosensory areas of classical somatotopic maps, and forepaw stimuli activated larger cortical areas with greater activation velocity than hindpaw stimuli. (4) Stimulation of the forepaw and hindpaw evoked different cortical activation dynamics: forepaw responses displayed a clear medial directionality, whereas hindpaw responses were much more uniform in all directions. In conclusion, this work offers a complete spatio-temporal map of the supragranular VSD cortical activation in response to stimulation of the paws, showing important somatotopic differences between contralateral and ipsilateral maps as well as differences in the spatio-temporal activation dynamics in response to forepaw and hindpaw stimuli. PMID:22829873

A useful method for assessing differences of compensatory hypertrophy in the contralateral kidney before and after radical nephrectomy in patients with renal cell carcinoma: ellipsoid formula on computed tomography.

PubMed

Park, Bong Hee; Cho, Kang Jun; Kim, Jung Im; Bae, Sang Rak; Lee, Yong Seok; Kang, Sung Hak; Kim, Joon Chul; Han, Chang Hee

2018-02-01

To investigate the usefulness of the ellipsoid formula for assessing compensatory hypertrophy of the contralateral kidney on pre-operative and post-operative CT in renal cell carcinoma (RCC) patients. We retrospectively identified 389 patients who had radical nephrectomy for RCC between 2011  and 2015. Contrast-enhanced CT was performed within 3 months pre-operative and at 1 year post-operative. The kidney volumes were calculated from CT using the ellipsoid formula. We subdivided patients into three groups based on tumour size (I: ≤4 cm, II: 4-7 cm, III: >7 cm). Volumetric renal parameters were compared and multivariate analyses were performed to determine predictors associated with pre-operative  and post-operative compensatory hypertrophy. Kidney volume calculation using the ellipsoid  method took a median of 51 s. Group III had a significantly larger median pre-operative contralateral renal volume than Groups I and II (I:  140.4, II: 141.6, III: 166.7 ml, p < 0.05). However, the median ratio of post-operative contralateral renal volume change was significantly higher in Groups I and II than Group III (I: 0.36, II: 0.23, III: 0.12, p < 0.001). On multivariate analysis, tumour size revealed the strongest positive association with pre-operative contralateral kidney volume (partial regression coefficient: β = 30.8, >7 cm) and ratio of post-operative contralateral kidney volume change (β  = 0.214, I vs III; β = 0.168, II vs III). Kidney volume calculation for assessing pre- and post-operative compensatory hypertrophy of the contralateral kidney in RCC patients can be easily and rapidly performed from CT images using the ellipsoid formula. Advances in knowledge: The ellipsoid formula allows reliable method for assessing pre-operative and post-operative compensatory hypertrophy of the contralateral kidney in RCC.

Analysis of electromyographic activity in spastic biceps brachii muscle following neural mobilization.

PubMed

Castilho, Jéssica; Ferreira, Luiz Alfredo Braun; Pereira, Wagner Menna; Neto, Hugo Pasini; Morelli, José Geraldo da Silva; Brandalize, Danielle; Kerppers, Ivo Ilvan; Oliveira, Claudia Santos

2012-07-01

Hypertonia is prevalent in anti-gravity muscles, such as the biceps brachii. Neural mobilization is one of the techniques currently used to reduce spasticity. The aim of the present study was to assess electromyographic (EMG) activity in spastic biceps brachii muscles before and after neural mobilization of the upper limb contralateral to the hemiplegia. Repeated pre-test and post-test EMG measurements were performed on six stroke victims with grade 1 or 2 spasticity (Modified Ashworth Scale). The Upper Limb Neurodynamic Test (ULNT1) was the mobilization technique employed. After neural mobilization contralateral to the lesion, electromyographic activity in the biceps brachii decreased by 17% and 11% for 90° flexion and complete extension of the elbow, respectively. However, the results were not statistically significant (p gt; 0.05). When performed using contralateral techniques, neural mobilization alters the electrical signal of spastic muscles. Copyright © 2011 Elsevier Ltd. All rights reserved.

Abnormal functional motor lateralization in healthy siblings of patients with schizophrenia.

PubMed

Altamura, Mario; Fazio, Leonardo; De Salvia, Michela; Petito, Annamaria; Blasi, Giuseppe; Taurisano, Paolo; Romano, Raffaella; Gelao, Barbara; Bellomo, Antonello; Bertolino, Alessandro

2012-07-30

Earlier neuroimaging studies of motor function in schizophrenia have demonstrated reduced functional lateralization in the motor network during motor tasks. Here, we used event-related functional magnetic resonance imaging during a visually guided motor task in 18 clinically unaffected siblings of patients with schizophrenia and 24 matched controls to investigate if abnormal functional lateralization is related to genetic risk for this brain disorder. Whereas activity associated with motor task performance was mainly contralateral with only a marginal ipsilateral component in healthy participants, unaffected siblings had strong bilateral activity with significantly greater response in ipsilateral and contralateral premotor areas as well as in contralateral subcortical motor regions relative to controls. Reduced lateralization in siblings was also identified with a measure of laterality quotient. These findings suggest that abnormal functional lateralization of motor circuitry is related to genetic risk of schizophrenia. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Changes in Abundance of Oral Microbiota Associated with Oral Cancer

PubMed Central

Schmidt, Brian L.; Kuczynski, Justin; Bhattacharya, Aditi; Huey, Bing; Corby, Patricia M.; Queiroz, Erica L. S.; Nightingale, Kira; Kerr, A. Ross; DeLacure, Mark D.; Veeramachaneni, Ratna; Olshen, Adam B.; Albertson, Donna G.

2014-01-01

Individual bacteria and shifts in the composition of the microbiome have been associated with human diseases including cancer. To investigate changes in the microbiome associated with oral cancers, we profiled cancers and anatomically matched contralateral normal tissue from the same patient by sequencing 16S rDNA hypervariable region amplicons. In cancer samples from both a discovery and a subsequent confirmation cohort, abundance of Firmicutes (especially Streptococcus) and Actinobacteria (especially Rothia) was significantly decreased relative to contralateral normal samples from the same patient. Significant decreases in abundance of these phyla were observed for pre-cancers, but not when comparing samples from contralateral sites (tongue and floor of mouth) from healthy individuals. Weighted UniFrac principal coordinates analysis based on 12 taxa separated most cancers from other samples with greatest separation of node positive cases. These studies begin to develop a framework for exploiting the oral microbiome for monitoring oral cancer development, progression and recurrence. PMID:24887397

In Vivo Measurement of Glenohumeral Joint Contact Patterns

NASA Astrophysics Data System (ADS)

Bey, Michael J.; Kline, Stephanie K.; Zauel, Roger; Kolowich, Patricia A.; Lock, Terrence R.

2009-12-01

The objectives of this study were to describe a technique for measuring in-vivo glenohumeral joint contact patterns during dynamic activities and to demonstrate application of this technique. The experimental technique calculated joint contact patterns by combining CT-based 3D bone models with joint motion data that were accurately measured from biplane x-ray images. Joint contact patterns were calculated for the repaired and contralateral shoulders of 20 patients who had undergone rotator cuff repair. Significant differences in joint contact patterns were detected due to abduction angle and shoulder condition (i.e., repaired versus contralateral). Abduction angle had a significant effect on the superior/inferior contact center position, with the average joint contact center of the repaired shoulder 12.1% higher on the glenoid than the contralateral shoulder. This technique provides clinically relevant information by calculating in-vivo joint contact patterns during dynamic conditions and overcomes many limitations associated with conventional techniques for quantifying joint mechanics.

Studies of the mechanism of contralateral polyuria after renal artery stenosis.

PubMed Central

Galvez, O G; Roberts, B W; Mishkind, M H; Bay, W H; Ferris, T F

1977-01-01

Acute renal artery stenosis in hydropenic dogs caused a contralateral increase in urine volume and free water clearance without change in glomerular filtration, renal blood flow, or osmolar clearance. The increase in urine volume was not dependent on the development of hypertension since it occurred in animals pretreated with trimethaphan but was dependent upon angiotensin since it was presented with angiotensin blockade with Saralasin. The effect was not caused by angiotensin inhibiting antidiuretic hormone release since the polyuria occurred in hypophysectomized animals receiving a constant infusion of 10 muU/kg per min of aqueous Pitressin. Since the rise in urine volume was associated with an increase in renal vein prostaglandin E concentration and was prevented by pretreatment with indomethacin (5 mg/kg) the results suggest that the rise in plasma angiotensin after renal artery stenosis causes an increase in contralateral prostaglandin E synthesis with resultant antagonism to antidiuretic hormone at the collecting tubule. PMID:845253

Contralateral Superior Cerebellar Artery Syndrome: A Consequence of Brain Herniation

PubMed Central

Mohseni, Meysam; Habibi, Zohreh; Nejat, Farideh

2017-01-01

Vascular compromise is a well-known consequence of brain herniation syndromes. Transtentorial brain herniation most often involves posterior cerebral arteries. However, isolated involvement of contralateral superior cerebellar artery (SCA) during unilateral impending brain herniation is reported only once and we present another case of this exceedingly rare entity. A 24-year-old man was referred to us with impending herniation due to a multiloculated hydrocephalus, and during the course of illness, he developed an isolated SCA ischemia in the opposite side of the most dilated entrapped horn. In the current article we discuss the probable pathophysiologic mechanisms of this phenomenon, as well as recommending more inclusive brain studies in cases suspected of Kernohan-Woltman notch phenomenon in unilateral brain herniation. The rationale for this commentary is that contralateral SCA transient ischemia or infarct might be the underdiagnosed underlying pathomechanism of ipsilateral hemiparesis occurring in many cases of this somehow vague phenomenon. PMID:28490164

More target features in visual working memory leads to poorer search guidance: Evidence from contralateral delay activity

PubMed Central

Schmidt, Joseph; MacNamara, Annmarie; Proudfit, Greg Hajcak; Zelinsky, Gregory J.

2014-01-01

The visual-search literature has assumed that the top-down target representation used to guide search resides in visual working memory (VWM). We directly tested this assumption using contralateral delay activity (CDA) to estimate the VWM load imposed by the target representation. In Experiment 1, observers previewed four photorealistic objects and were cued to remember the two objects appearing to the left or right of central fixation; Experiment 2 was identical except that observers previewed two photorealistic objects and were cued to remember one. CDA was measured during a delay following preview offset but before onset of a four-object search array. One of the targets was always present, and observers were asked to make an eye movement to it and press a button. We found lower magnitude CDA on trials when the initial search saccade was directed to the target (strong guidance) compared to when it was not (weak guidance). This difference also tended to be larger shortly before search-display onset and was largely unaffected by VWM item-capacity limits or number of previews. Moreover, the difference between mean strong- and weak-guidance CDA was proportional to the increase in search time between mean strong-and weak-guidance trials (as measured by time-to-target and reaction-time difference scores). Contrary to most search models, our data suggest that trials resulting in the maintenance of more target features results in poor search guidance to a target. We interpret these counterintuitive findings as evidence for strong search guidance using a small set of highly discriminative target features that remain after pruning from a larger set of features, with the load imposed on VWM varying with this feature-consolidation process. PMID:24599946

More target features in visual working memory leads to poorer search guidance: evidence from contralateral delay activity.

PubMed

Schmidt, Joseph; MacNamara, Annmarie; Proudfit, Greg Hajcak; Zelinsky, Gregory J

2014-03-05

The visual-search literature has assumed that the top-down target representation used to guide search resides in visual working memory (VWM). We directly tested this assumption using contralateral delay activity (CDA) to estimate the VWM load imposed by the target representation. In Experiment 1, observers previewed four photorealistic objects and were cued to remember the two objects appearing to the left or right of central fixation; Experiment 2 was identical except that observers previewed two photorealistic objects and were cued to remember one. CDA was measured during a delay following preview offset but before onset of a four-object search array. One of the targets was always present, and observers were asked to make an eye movement to it and press a button. We found lower magnitude CDA on trials when the initial search saccade was directed to the target (strong guidance) compared to when it was not (weak guidance). This difference also tended to be larger shortly before search-display onset and was largely unaffected by VWM item-capacity limits or number of previews. Moreover, the difference between mean strong- and weak-guidance CDA was proportional to the increase in search time between mean strong-and weak-guidance trials (as measured by time-to-target and reaction-time difference scores). Contrary to most search models, our data suggest that trials resulting in the maintenance of more target features results in poor search guidance to a target. We interpret these counterintuitive findings as evidence for strong search guidance using a small set of highly discriminative target features that remain after pruning from a larger set of features, with the load imposed on VWM varying with this feature-consolidation process.

Magnifications of Single and Dual Element Accommodative Intraocular Lenses: Paraxial Optics Analysis

PubMed Central

Ale, Jit B; Manns, Fabrice; Ho, Arthur

2010-01-01

Purpose Using an analytical approach of paraxial optics, we evaluated the magnification of a model eye implanted with single-element (1E) and dual-element (2E) translating-optics accommodative intraocular lenses (AIOL) with an objective of understanding key control parameters relevant to their design. Potential clinical implications of the results arising from pseudophakic accommodation were also considered. Methods Lateral and angular magnifications in a pseudophakic model eye were analyzed using the matrix method of paraxial optics. The effects of key control parameters such as direction (forward or backward) and distance (0 to 2 mm) of translation, power combinations of the 2E-AIOL elements (front element power range +20.0 D to +40.0 D), and amplitudes of accommodation (0 to 4 D) were tested. Relative magnification, defined as the ratio of the retinal image size of the accommodated eye to that of unaccommodated phakic (rLM1) or pseudophakic (rLM2) model eyes, was computed to determine how retinal image size changes with pseudophakic accommodation. Results Both lateral and angular magnifications increased with increased power of the front element in 2E-AIOL and amplitude of accommodation. For a 2E-AIOL with front element power of +35 D, rLM1 and rLM2 increased by 17.0% and 16.3%, respectively, per millimetre of forward translation of the element, compared to the magnification at distance focus (unaccommodated). These changes correspond to a change of 9.4% and 6.5% per dioptre of accommodation, respectively. Angular magnification also increased with pseudophakic accommodation. 1E-AIOLs produced consistently less magnification than 2E-AIOLs. Relative retinal image size decreased at a rate of 0.25% with each dioptre of accommodation in the phakic model eye. The position of the image space nodal point shifted away from the retina (towards the cornea) with both phakic and pseudophakic accommodation. Conclusion Power of the mobile element, and amount and direction of the translation (or the achieved accommodative amplitude) are important parameters in determining the magnifications of the AIOLs. The results highlight the need for caution in the prescribing of AIOL. Aniso-accommodation or inter-ocular differences in AIOL designs (or relative to the natural lens of the contralateral eye) may introduce dynamic aniseikonia and consequent impaired binocular vision. Nevertheless, some designs, offering greater increases in magnification on accommodation, may provide enhanced near vision depending on patient needs. PMID:21054469

Which surgery should be offered for carpal tunnel syndrome in a patient who was previously treated for recurrence on the contralateral side? Preliminary study of 13 patients with the Canaletto® implant.

PubMed

Illuminati, I; Seigle-Murandi, F; Gouzou, S; Fabacher, T; Facca, S; Hidalgo Diaz, J J; Liverneaux, P

2017-12-01

There are no published studies on the management of carpal tunnel syndrome (CTS) patients who have already been operated for recurrent CTS on the contralateral side. The aim of this study was to evaluate 13 patients with CTS who underwent primary release using a Canaletto ® implant. The 13 patients had all been operated for recurrent CTS previously. On the contralateral side, they all had subjective signs, and two of them already had complications. All were operated with the Canaletto ® implant according to Duché's technique, in a mean of 20minutes. After a mean 19.3-month follow-up, paresthesia, pain, and QuickDASH scores were significantly improved, even in one patient who underwent revision at another facility. This preliminary study suggests that use of a Canaletto ® implant as first-line treatment for CTS in patients who already underwent revision surgery on the other side is a simple and safe technique, without worsening of symptoms. These findings should be assessed with a prospective randomized controlled trial. Copyright © 2017 SFCM. Published by Elsevier Masson SAS. All rights reserved.

What Drives Bird Vision? Bill Control and Predator Detection Overshadow Flight.

PubMed

Martin, Graham R

2017-01-01

Although flight is regarded as a key behavior of birds this review argues that the perceptual demands for its control are met within constraints set by the perceptual demands of two other key tasks: the control of bill (or feet) position, and the detection of food items/predators. Control of bill position, or of the feet when used in foraging, and timing of their arrival at a target, are based upon information derived from the optic flow-field in the binocular region that encompasses the bill. Flow-fields use information extracted from close to the bird using vision of relatively low spatial resolution. The detection of food items and predators is based upon information detected at a greater distance and depends upon regions in the retina with relatively high spatial resolution. The tasks of detecting predators and of placing the bill (or feet) accurately, make contradictory demands upon vision and these have resulted in trade-offs in the form of visual fields and in the topography of retinal regions in which spatial resolution is enhanced, indicated by foveas, areas, and high ganglion cell densities. The informational function of binocular vision in birds does not lie in binocularity per se (i.e., two eyes receiving slightly different information simultaneously about the same objects) but in the contralateral projection of the visual field of each eye. This ensures that each eye receives information from a symmetrically expanding optic flow-field centered close to the direction of the bill, and from this the crucial information of direction of travel and time-to-contact can be extracted, almost instantaneously. Interspecific comparisons of visual fields between closely related species have shown that small differences in foraging techniques can give rise to different perceptual challenges and these have resulted in differences in visual fields even within the same genus. This suggests that vision is subject to continuing and relatively rapid natural selection based upon individual differences in the structure of the optical system, retinal topography, and eye position in the skull. From a sensory ecology perspective a bird is best characterized as "a bill guided by an eye" and that control of flight is achieved within constraints on visual capacity dictated primarily by the demands of foraging and bill control.

Estimating associations of mobile phone use and brain tumours taking into account laterality: a comparison and theoretical evaluation of applied methods.

PubMed

Frederiksen, Kirsten; Deltour, Isabelle; Schüz, Joachim

2012-12-10

Estimating exposure-outcome associations using laterality information on exposure and on outcome is an issue, when estimating associations of mobile phone use and brain tumour risk. The exposure is localized; therefore, a potential risk is expected to exist primarily on the side of the head, where the phone is usually held (ipsilateral exposure), and to a lesser extent at the opposite side of the head (contralateral exposure). Several measures of the associations with ipsilateral and contralateral exposure, dealing with different sampling designs, have been presented in the literature. This paper presents a general framework for the analysis of such studies using a likelihood-based approach in a competing risks model setting. The approach clarifies the implicit assumptions required for the validity of the presented estimators, particularly that in some approaches the risk with contralateral exposure is assumed to be zero. The performance of the estimators is illustrated in a simulation study showing for instance that while in some scenarios there is a loss of statistical power, others - in case of a positive ipsilateral exposure-outcome association - would result in a negatively biased estimate of the contralateral exposure parameter, irrespective of any additional recall bias. In conclusion, our theoretical evaluations and results from the simulation study emphasize the importance of setting up a formal model, which furthermore allows for estimation in more complicated and perhaps more realistic exposure settings, such as taking into account exposure to both sides of the head. Copyright © 2012 John Wiley & Sons, Ltd.

Proteomic analysis of trans-hemispheric motor cortex reorganization following contralateral C7 nerve transfer

PubMed Central

Yuan, Yin; Xu, Xiu-yue; Lao, Jie; Zhao, Xin

2018-01-01

Nerve transfer is the most common treatment for total brachial plexus avulsion injury. After nerve transfer, the movement of the injured limb may be activated by certain movements of the healthy limb at the early stage of recovery, i.e., trans-hemispheric reorganization. Previous studies have focused on functional magnetic resonance imaging and changes in brain-derived neurotrophic factor and growth associated protein 43, but there have been no proteomics studies. In this study, we designed a rat model of total brachial plexus avulsion injury involving contralateral C7 nerve transfer. Isobaric tags for relative and absolute quantitation and western blot assay were then used to screen differentially expressed proteins in bilateral motor cortices. We found that most differentially expressed proteins in both cortices of upper limb were associated with nervous system development and function (including neuron differentiation and development, axonogenesis, and guidance), microtubule and cytoskeleton organization, synapse plasticity, and transmission of nerve impulses. Two key differentially expressed proteins, neurofilament light (NFL) and Thy-1, were identified. In contralateral cortex, the NFL level was upregulated 2 weeks after transfer and downregulated at 1 and 5 months. The Thy-1 level was upregulated from 1 to 5 months. In the affected cortex, the NFL level increased gradually from 1 to 5 months. Western blot results of key differentially expressed proteins were consistent with the proteomic findings. These results indicate that NFL and Thy-1 play an important role in trans-hemispheric organization following total brachial plexus root avulsion and contralateral C7 nerve transfer. PMID:29557385

The correlation of background parenchymal enhancement in the contralateral breast with patient and tumor characteristics of MRI-screen detected breast cancers.

PubMed

Vreemann, Suzan; Gubern-Mérida, Albert; Borelli, Cristina; Bult, Peter; Karssemeijer, Nico; Mann, Ritse M

2018-01-01

Higher background parenchymal enhancement (BPE) could be used for stratification of MRI screening programs since it might be related to a higher breast cancer risk. Therefore, the purpose of this study is to correlate BPE to patient and tumor characteristics in women with unilateral MRI-screen detected breast cancer who participated in an intermediate and high risk screening program. As BPE in the affected breast may be difficult to discern from enhancing cancer, we assumed that BPE in the contralateral breast is a representative measure for BPE in women with unilateral breast cancer. This retrospective study was approved by our local institutional board and a waiver for consent was granted. MR-examinations of women with unilateral breast cancers screen-detected on breast MRI were evaluated by two readers. BPE in the contralateral breast was rated according to BI-RADS. Univariate analyses were performed to study associations. Observer variability was computed. Analysis included 77 breast cancers in 76 patients (age: 48±9.8 years), including 62 invasive and 15 pure ductal carcinoma in-situ cases. A negative association between BPE and tumor grade (p≤0.016) and a positive association with progesterone status (p≤0.021) was found. The correlation was stronger when only considering invasive disease. Inter-reader agreement was substantial. Lower BPE in the contralateral breast in women with unilateral breast cancer might be associated to higher tumor grade and progesterone receptor negativity. Great care should be taken using BPE for stratification of patients to tailored screening programs.

Endodontic management of contralateral mandibular first molars with six root canals

PubMed Central

Bhargav, Kambhampati; Sirisha, Kantheti; Jyothi, Mandava; Boddeda, Mohan Rao

2017-01-01

The knowledge of variations in root canal morphology is essential for a successful endodontic outcome. Contralateral mandibular molar with six root canals is a rare entity. Root canal treatment of mandibular molars with aberrant canal configuration can be diagnostically and technically challenging. While dealing with variant mandibular molars, mishaps may happen. This case report describes variations in contralateral mandibular molars and also an endodontic mishap while managing them. PMID:29259369

The predictive value of retinal vascular findings for carotid artery atherosclerosis: are further recommendations with regard to carotid atherosclerosis screening needed?

PubMed

Song, Yeo-Jeong; Cho, Kyoung-Im; Kim, Seong-Man; Jang, Hyun-Duk; Park, Jung-Min; Kim, Sang-Soo; Kim, Dong-Jun; Lee, Hyeon-Gook; Kim, Tae-Ik

2013-05-01

Vascular retinopathy is the consequence of vascular disease, and the retina is the only place where the arteries can be visualized directly. The purpose of this study was to evaluate the predictive value of retinal vascular findings for carotid artery atherosclerosis. From December 2009 to January 2011, the carotid intima-media thickness (IMT) and total plaque area (TPA) were measured in 179 consecutive patients, who received a fundoscopic examination. The patients were divided into groups as follows: normal retinal artery (normal; n = 44), diabetic retinopathy (DR; n = 25), retinal artery occlusion (RAO; n = 17), retinal vein occlusion (RVO; n = 67), and hypertensive retinopathy (HTN-R; n = 26). The subjects were classified according to the presence of an increased (≥ 1 mm) IMT and plaque. The values of the mean carotid IMT in the patients with vascular retinopathy (DR, 0.87 ± 0.14 mm; RAO, 1.18 ± 0.47 mm; RVO, 0.84 ± 0.14 mm; HTN-R, 0.90 ± 0.20 mm) were significantly increased compared with those in the normal subjects (0.77 ± 0.13 mm). A total 77 of 135 vascular retinopathy patients demonstrated an increased IMT (57 %), and 97 vascular retinopathy patients had carotid artery plaque (72 %). The relative risk of vascular retinopathy in the prediction of an increased IMT and the presence of plaque was 2.79 and 3.95, respectively. Although The TPA was significantly increased in the patients with RAO (1.87 ± 2.67 cm(2)) and RVO (0.27 ± 0.23 cm(2)) compared with the normal subjects (0.18 ± 0.23 cm(2), all Ps < 0.05), there was no significant difference in the ipsilateral carotid IMT and TPA of the affected eye compared with that of the contralateral eye. In conclusion, vascular retinopathy demonstrated a good predictive value in identifying asymptomatic carotid artery atherosclerosis, and this was not confined to the ipsilateral carotid artery of the affected eye. Further recommendations with regard to carotid atherosclerosis screening in patients with vascular retinopathy should be considered.

Biomechanics of unilateral and bilateral sacroiliac joint stabilization: laboratory investigation.

PubMed

Lindsey, Derek P; Parrish, Robin; Gundanna, Mukund; Leasure, Jeremi; Yerby, Scott A; Kondrashov, Dimitriy

2018-03-01

OBJECTIVE Bilateral symptoms have been reported in 8%-35% of patients with sacroiliac (SI) joint dysfunction. Stabilization of a single SI joint may significantly alter the stresses on the contralateral SI joint. If the contralateral SI joint stresses are significantly increased, degeneration may occur; alternatively, if the stresses are significantly reduced, bilateral stabilization may be unnecessary for patients with bilateral symptoms. The biomechanical effects of 1) unilateral stabilization on the contralateral SI joint and 2) bilateral stabilization on both SI joints are currently unknown. The objectives of this study were to characterize bilateral SI joint range of motion (ROM) and evaluate and compare the biomechanical effects of unilateral and bilateral implant placement for SI joint fusion. METHODS A lumbopelvic model (L5-pelvis) was used to test the ROM of both SI joints in 8 cadavers. A single-leg stance setup was used to load the lumbar spine and measure the ROM of each SI joint in flexion-extension, lateral bending, and axial rotation. Both joints were tested 1) while intact, 2) after unilateral stabilization, and 3) after bilateral stabilization. Stabilization consisted of lateral transiliac placement of 3 triangular titanium plasma-sprayed (TPS) implants. RESULTS Intact testing showed that during single-leg stance the contralateral SI joint had less ROM in flexion-extension (27%), lateral bending (32%), and axial rotation (69%) than the loaded joint. Unilateral stabilization resulted in significant reduction of flexion-extension ROM (46%) on the treated side; no significant ROM changes were observed for the nontreated side. Bilateral stabilization resulted in significant reduction of flexion-extension ROM of the primary (45%) and secondary (75%) SI joints. CONCLUSIONS This study demonstrated that during single-leg loading the ROMs for the stance (loaded) and swing (unloaded) SI joints are significantly different. Unilateral stabilization for SI joint dysfunction significantly reduces the ROM of the treated side, but does not significantly reduce the ROM of the nontreated contralateral SI joint. Bilateral stabilization is necessary to significantly reduce the ROM for both SI joints.

Hindlimb spasticity after unilateral motor cortex lesion in rats is reduced by contralateral nerve root transfer.

PubMed

Zong, Haiyang; Ma, Fenfen; Zhang, Laiyin; Lu, Huiping; Gong, Jingru; Cai, Min; Lin, Haodong; Zhu, Yizhun; Hou, Chunlin

2016-12-01

Lower extremity spasticity is a common sequela among patients with acquired brain injury. The optimum treatment remains controversial. The aim of our study was to test the feasibility and effectiveness of contralateral nerve root transfer in reducing post stroke spasticity of the affected hindlimb muscles in rats. In our study, we for the first time created a novel animal hindlimb spastic hemiplegia model in rats with photothrombotic lesion of unilateral motor cortex and we established a novel surgical procedure in reducing motor cortex lesion-induced hindlimb spastic hemiplegia in rats. Thirty six rats were randomized into three groups. In group A, rats received sham operation. In group B, rats underwent unilateral hindlimb motor cortex lesion. In group C, rats underwent unilateral hindlimb cortex lesion followed by contralateral L4 ventral root transfer to L5 ventral root of the affected side. Footprint analysis, Hoffmann reflex (H-reflex), cholera toxin subunit B (CTB) retrograde tracing of gastrocnemius muscle (GM) motoneurons and immunofluorescent staining of vesicle glutamate transporter 1 (VGLUT1) on CTB-labelled motoneurons were used to assess spasticity of the affected hindlimb. Sixteen weeks postoperatively, toe spread and stride length recovered significantly in group C compared with group B (P<0.001). H max (H-wave maximum amplitude)/M max (M-wave maximum amplitude) ratio of gastrocnemius and plantaris muscles (PMs) significantly reduced in group C (P<0.01). Average VGLUT1 positive boutons per CTB-labelled motoneurons significantly reduced in group C (P<0.001). We demonstrated for the first time that contralateral L4 ventral root transfer to L5 ventral root of the affected side was effective in relieving unilateral motor cortex lesion-induced hindlimb spasticity in rats. Our data indicated that this could be an alternative treatment for unilateral lower extremity spasticity after brain injury. Therefore, contralateral neurotization may exert a potential therapeutic candidate to improve the function of lower extremity in patients with spastic hemiplegia. © 2016 The Author(s).

The Role of Procurement Biopsies in Acceptance Decisions for Kidneys Retrieved for Transplant

PubMed Central

Stewart, Darren E.; Bista, Bipin R.; Salkowski, Nicholas; Snyder, Jon J.; Israni, Ajay K.; Crary, Gretchen S.; Rosendale, John D.; Matas, Arthur J.; Delmonico, Francis L.

2014-01-01

Background and objectives There is a shortage of kidneys for transplant, and many patients on the deceased donor kidney transplant waiting list would likely benefit from kidneys that are currently being discarded. In the United States, the most common reason given for discarding kidneys retrieved for transplant is procurement biopsy results. This study aimed to compare biopsy results from discarded kidneys with discard attributed to biopsy findings, with biopsy results from comparable kidneys that were successfully transplanted. Design, setting, participants, & measurements In this retrospective, observational, case-control study, biopsy reports were examined from 83 kidneys discarded in 2010 due to biopsy findings (cases), 83 contralateral transplanted kidneys from the same donor (contralateral controls), and 83 deceased donors randomly matched to cases by donor risk profile (randomly matched controls). A second procurement biopsy was obtained in 64 of 332 kidneys (19.3%). Results The quality of biopsy reports was low, with amounts of tubular atrophy, interstitial inflammation, arteriolar hyalinosis, and acute tubular necrosis often not indicated; 69% were wedge biopsies and 94% used frozen tissue. The correlation between first and second procurement biopsies was poor; only 25% of the variability (R2) in glomerulosclerosis was explained by biopsies being from the same kidney. The percentages of glomerulosclerosis overlapped substantially between cases, contralateral controls, and randomly matched controls: 17.1%±15.3%, 9.0%±6.6%, and 5.0%±5.9%, respectively. Of all biopsy findings, only glomerulosclerosis>20% was independently correlated with discard (cases versus contralateral controls; odds ratio, 15.09; 95% confidence interval, 2.47 to 92.41; P=0.003), suggesting that only this biopsy result was used in acceptance decisions. One-year graft survival was 79.5% and 90.7% in contralateral and randomly matched controls, respectively, versus 91.6% among all deceased donor transplants in the Scientific Registry of Transplant Recipients. Conclusions Routine use of biopsies could lead to unnecessary kidney discards. PMID:24558053

SU-E-J-87: Ventilation Weighting Effect On Mean Doses of Both Side Lungs for Patients with Advanced Stage Lung Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qu, H; Xia, P; Yu, N

Purpose: To study ventilation weighting effect on radiation doses to both side lungs for patients with advanced stage lung cancer. Methods: Fourteen patients with advanced stage lung cancer were included in this retrospective study. Proprietary software was developed to calculate the lung ventilation map based on 4DCT images acquired for radiation therapy. Two phases of inhale (0%) and exhale (50%) were used for the lung ventilation calculations. For each patient, the CT images were resampled to the same dose calculation resolution of 3mmx3mmx3mm. The ventilation distribution was then normalized by the mean value of the ventilation. The ventilation weighted dosemore » was calculated by applying linearly weighted ventilation to the dose of each pixel. The lung contours were automatically delineated from patient CT image with lung window, excluding the tumor and high density tissues. For contralateral and ipsilateral lungs, the mean lung doses from the original plan and ventilation weighted mean lung doses were compared using two tail t-Test. Results: The average of mean dose was 6.1 ±3.8Gy for the contralateral lungs, and 26.2 ± 14.0Gy for the ipsilateral lungs. The average of ventilation weighted dose was 6.3± 3.8Gy for the contralateral lungs and 24.6 ± 13.1Gy for the ipsilateral lungs. The statistics analysis shows the significance of the mean dose increase (p<0.015) for the contralateral lungs and decrease (p<0.005) for the ipsilateral lungs. Conclusion: Ventilation weighted doses were greater than the un-weighted doses for contralateral lungs and smaller for ipsilateral lungs. This Result may be helpful to understand the radiation dosimetric effect on the lung function and provide planning guidance for patients with advance stage lung cancer.« less

A Standardized Rat Model of Volumetric Muscle Loss Injury for the Development of Tissue Engineering Therapies

PubMed Central

Wu, Xiaowu; Corona, Benjamin T.; Chen, Xiaoyu

2012-01-01

Abstract Soft tissue injuries involving volumetric muscle loss (VML) are defined as the traumatic or surgical loss of skeletal muscle with resultant functional impairment and represent a challenging clinical problem for both military and civilian medicine. In response, a variety of tissue engineering and regenerative medicine treatments are under preclinical development. A wide variety of animal models are being used, all with critical limitations. The objective of this study was to develop a model of VML that was reproducible and technically uncomplicated to provide a standardized platform for the development of tissue engineering and regenerative medicine solutions to VML repair. A rat model of VML involving excision of ∼20% of the muscle's mass from the superficial portion of the middle third of the tibialis anterior (TA) muscle was developed and was functionally characterized. The contralateral TA muscle served as the uninjured control. Additionally, uninjured age-matched control rats were also tested to determine the effect of VML on the contralateral limb. TA muscles were assessed at 2 and 4 months postinjury. VML muscles weighed 22.7% and 19.5% less than contralateral muscles at 2 and 4 months postinjury, respectively. These differences were accompanied by a reduction in peak isometric tetanic force (Po) of 28.4% and 32.5% at 2 and 4 months. Importantly, Po corrected for differences in body weight and muscle wet weights were similar between contralateral and age-matched control muscles, indicating that VML did not have a significant impact on the contralateral limb. Lastly, repair of the injury with a biological scaffold resulted in rapid vascularization and integration with the wound. The technical simplicity, reliability, and clinical relevance of the VML model developed in this study make it ideal as a standard model for the development of tissue engineering solutions for VML. PMID:23515319

Probing the Effects and Mechanisms of Electroacupuncture at Ipsilateral or Contralateral ST36–ST37 Acupoints on CFA-induced Inflammatory Pain

PubMed Central

Lu, Kung-Wen; Hsu, Chao-Kuei; Hsieh, Ching-Liang; Yang, Jun; Lin, Yi-Wen

2016-01-01

Transient receptor potential vanilloid 1 (TRPV1) and associated signaling pathways have been reported to be increased in inflammatory pain signaling. There are accumulating evidences surrounding the therapeutic effect of electroacupuncture (EA). EA can reliably attenuate the increase of TRPV1 in mouse inflammatory pain models with unclear signaling mechanisms. Moreover, the difference in the clinical therapeutic effects between using the contralateral and ipsilateral acupoints has been rarely studied. We found that inflammatory pain, which was induced by injecting the complete Freund’s adjuvant (CFA), (2.14 ± 0.1, p < 0.05, n = 8) can be alleviated after EA treatment at either ipsilateral (3.91 ± 0.21, p < 0.05, n = 8) or contralateral acupoints (3.79 ± 0.25, p < 0.05, n = 8). EA may also reduce nociceptive Nav sodium currents in dorsal root ganglion (DRG) neurons. The expression of TRPV1 and associated signaling pathways notably increased after the CFA injection; this expression can be further attenuated significantly in EA treatment. TRPV1 and associated signaling pathways can be prevented in TRPV1 knockout mice, suggesting that TRPV1 knockout mice are resistant to inflammatory pain. Through this study, we have increased the understanding of the mechanism that both ipsilateral and contralateral EA might alter TRPV1 and associated signaling pathways to reduce inflammatory pain. PMID:26906464

Assessment of volume measurement of breast cancer-related lymphedema by three methods: circumference measurement, water displacement, and dual energy X-ray absorptiometry.

PubMed

Gjorup, Caroline; Zerahn, Bo; Hendel, Helle W

2010-06-01

Following treatment for breast cancer 12%-60% develop breast cancer-related lymphedema (BCRL). There are several ways of assessing BCRL. Circumference measurement (CM) and water displacement (WD) for volume measurements (VM) are frequently used methods in practice and research, respectively. The aim of this study was to evaluate CM and WD for VM of the BCRL arm and the contralateral arm, comparing the results with regional dual energy X-ray absorptiometry (DXA). Twenty-four women with unilateral BCRL were included in the study. Blinded duplicate VM were obtained from both arms using the three methods mentioned above. CM and DXA were performed by two observers. WD was performed by a group of observers. Mean differences (d) in duplicated volumes, limits of agreement (LOA), and 95% confidence intervals (CI) were calculated for each method. The repeatability expressed as d (95% CI) between the duplicated VM of the BCRL arm and the contralateral arm was for DXA 3 ml (-6-11) and 3 ml (1-7), respectively. For CM and WD, the d (95% CI) of the BCRL arm were 107 ml (86-127) and 26 ml (-26-79), respectively and in the contralateral arm 100 ml (78-122) and -6 ml (-29-17), respectively. DXA is superior in repeatability when compared to CM and WD for VM, especially for the BCRL arm but also the contralateral arm.

Difference of motor overflow depending on the impaired or unimpaired hand in stroke patients.

PubMed

Kim, Yushin; Kim, Woo-Sub; Shim, Jae Kun; Suh, Dong Won; Kim, TaeYeong; Yoon, BumChul

2015-02-01

The aim of this study was to investigate the patterns of contralateral motor overflow (i.e. mirror movement) between the homologous body parts on the right and left side, in stroke patients during single-finger and multi-finger maximum force production tasks. Forty subjects, including stroke (n=20) and normal subjects (n=20), participated in this study. The stroke subjects maximally pressed force sensors with their fingers in a flexed position using a single (index, middle, ring, or little) or all fingers (all 4 fingers) using the impaired (IH) or unimpaired (UIH) hand, while the non-patient subjects used their right hands for the same tasks. The maximal voluntary forces in the ipsilateral and unintended pressing forces of each contralateral finger were recorded during the tasks. The magnitude of motor overflow to the contralateral side was calculated using the index of contralateral independence (CI). During the single finger tasks, the finger CI was significantly decreased in the UIH (91%) compared with that in the IH (99%) or normal hands (99%). Likewise, the multiple finger tasks showed that the CI was significantly lower in the UIH (84%) compared with that in the IH (96%) or normal hands (99%). However, the maximal forces were significantly lower in the IH relative to those in the UIH and normal hands. These data demonstrate that stroke patients have greater motor overflow from the UIH to the IH. Copyright © 2014 Elsevier B.V. All rights reserved.

Three-dimensional analysis of a ballet dancer with ischial tuberosity apophysitis. A case study.

PubMed

Pohjola, Hanna; Sayers, Mark; Mellifont, Rebecca; Mellifont, Daniel; Venojärvi, Mika

2014-12-01

The purpose of this case study was to describe the three-dimensional biomechanics of common ballet exercises in a ballet dancer with ischial tuberosity apophysitis. This was achieved by comparing kinematics between the symptomatic (i.e. ischial apophyseal symptoms) and contralateral lower limbs, as well as via reported pain. Results suggest consistent differences in movement patterns in this dancer. These differences included: 1) decreased external rotation of contralateral hip, hence a decreased hip contribution to 'turn out'; 2) increased contralateral knee adduction and internal rotation; 3) an apparent synchronicity in the contralateral lower limb of the decreased hip external rotation and increased knee adduction; and 4) minimal use of ankle plantar/dorsiflexion movement for symptomatic side. Pain related to the left ischial apophysitis was associated with reduced amplitudes especially in fast ballet movements that required large range of motion in flexion and adduction in the left hip joint. These findings suggest that ischial apophysitis may limit dancer's ballet technique and performance. Key PointsThe pain related to the left ischial apophysitis was associated with reduced amplitudes especially in fast ballet movements that require large range of motion. This may affect to the lower limbs kinematics, and limit dancer's technique and performance.Compensatory strategies in the kinetic chain, differences in the joint angles between the lower limbs, traction forces, velocity and amplitude demands should be taken in consideration while training and rehabilitation of the ischial apophyseal injury within classical ballet.

Study of external root resorption during orthodontic treatment in root filled teeth compared with their contralateral teeth with vital pulps.

PubMed

Llamas-Carreras, J M; Amarilla, A; Solano, E; Velasco-Ortega, E; Rodríguez-Varo, L; Segura-Egea, J J

2010-08-01

To determine whether root filled teeth and those with vital pulps exhibit a similar degree of external root resorption (ERR) as a consequence of orthodontic treatment. The study sample consisted of 77 patients, with a mean age of 32.7 +/- 10.7 years, who had one root filled tooth before completion of multiband/bracket orthodontic therapy for at least 1 year. For each patient, digital panoramic radiographs taken before and after orthodontic treatment were used to determine the proportion of external root resorption (PRR), defined as the ratio between the root resorption in the root filled tooth and that in its contralateral tooth with a vital pulp. The student's t-test, anova and logistic regression analysis were used to determine statistical significance. The mean PRR was 1.00 +/- 0.13, indicating that, in the total sample, there were no significant differences in root resorption in the root filled teeth and their contralateral teeth with vital pulps. Multivariate logistic regression analysis suggested that PRR was significantly greater in incisors (P = 0.0014; odds ratio = 6.2885, C.I. 95% = 2.0-19.4), compared to other teeth, and in women (P = 0.0255; odds ratio = 4.2, C.I. 95% = 1.2-14.6), compared to men. There was no significant difference in the amount or severity of external root resorption during orthodontic movement between root filled teeth and their contralateral teeth with vital pulps.

Leg kinematics and kinetics in landing from a single-leg hop for distance. A comparison between dominant and non-dominant leg.

PubMed

van der Harst, J J; Gokeler, A; Hof, A L

2007-07-01

Anterior cruciate ligament (ACL) deficiency can be a major problem for athletes and subsequent reconstruction of the ACL may be indicated if a conservative regimen has failed. After ACL reconstruction signs of abnormality in the use of the leg remain for a long time. It is expected that the landing after a single-leg hop for distance (horizontal hop) might give insight in the differences in kinematics and kinetics between uninjured legs and ACL-reconstructed legs. Before the ACL-reconstructed leg can be compared with the contralateral leg, knowledge of differences between legs of uninjured subjects is needed. Kinematic and kinetic variables of both legs were measured with an optoelectronic system and a force plate and calculated by inverse dynamics. The dominant leg (the leg with biggest horizontal hop distance) and the contralateral leg of nine uninjured subjects were compared. No significant differences were found in most of the kinematic and kinetic variables between dominant leg and contralateral leg of uninjured subjects. Only hop distance and hip extension angles differed significantly. This study suggests that there are no important differences between dominant leg and contralateral leg in healthy subjects. As a consequence, the uninvolved leg of ACL-reconstructed patients can be used as a reference. The observed variables of this study can be used as a reference of normal values and normal differences between legs in healthy subjects.

Transrectal Doppler sonography of uterine blood flow during the first two weeks after parturition in Simmenthal heifers

PubMed Central

Krüger, Lars; Leidl, Stephanie; Bollwein, Heinrich

2013-01-01

Transrectal Doppler sonography was used to evaluate uterine blood flow during the first two weeks after parturition in six primiparous Simmental cows. The uterine blood flow was evaluated on the day of parturition (Day 0), once daily from Days 1 to 8 and then every other day until Day 14. Blood flow was quantified by determining the diameter (D), the time-averaged maximum velocity (TAMV), the pulsatility index (PI) and the blood flow volume (BFV) of the uterine arteries ipsilateral and contralateral to the formerly pregnant uterine horn. During the first four days after calving D, TAMV and BFV declined (ipsilateral: TAMV 70%, BFV 87%, contralateral: D 47%, BFV 84%; p < 0.05), while PI increased (ipsilateral 158%, contralateral 100%; p < 0.05) distinctly. Between Days 4 and 14 only the ipsilateral D (12%) and the BFV of both arteries (ipsilateral 5%, contralateral 8%) decreased (p < 0.05). Blood flow variables were very strongly correlated with each other (r > ±0.75, p < 0.05), with negative correlations with PI and positive correlations with all other investigated factors. Overall, this study revealed characteristic changes in uterine perfusion during the first two weeks after parturition in cows that were pronounced during the first four days postpartum. PMID:23820167

Transrectal Doppler sonography of uterine blood flow during the first two weeks after parturition in Simmenthal heifers.

PubMed

Heppelmann, Maike; Krüger, Lars; Leidl, Stephanie; Bollwein, Heinrich

2013-01-01

Transrectal Doppler sonography was used to evaluate uterine blood flow during the first two weeks after parturition in six primiparous Simmental cows. The uterine blood flow was evaluated on the day of parturition (Day 0), once daily from Days 1 to 8 and then every other day until Day 14. Blood flow was quantified by determining the diameter (D), the time-averaged maximum velocity (TAMV), the pulsatility index (PI) and the blood flow volume (BFV) of the uterine arteries ipsilateral and contralateral to the formerly pregnant uterine horn. During the first four days after calving D, TAMV and BFV declined (ipsilateral: TAMV 70%, BFV 87%, contralateral: D 47%, BFV 84%; p < 0.05), while PI increased (ipsilateral 158%, contralateral 100%; p < 0.05) distinctly. Between Days 4 and 14 only the ipsilateral D (12%) and the BFV of both arteries (ipsilateral 5%, contralateral 8%) decreased (p < 0.05). Blood flow variables were very strongly correlated with each other (r > ±0.75, p < 0.05), with negative correlations with PI and positive correlations with all other investigated factors. Overall, this study revealed characteristic changes in uterine perfusion during the first two weeks after parturition in cows that were pronounced during the first four days postpartum.

Changes in Serial Optical Topography and TMS during Task Performance after Constraint-Induced Movement Therapy in Stroke: A Case Study

PubMed Central

Park, Si-Woon; Butler, Andrew J.; Cavalheiro, Vanessa; Alberts, Jay L.; Wolf, Steven L.

2013-01-01

The authors examined serial changes in optical topography in a stroke patient performing a functional task, as well as clinical and physiologic measures while undergoing constraint-induced therapy (CIT). A 73-year-old right hemiparetic patient, who had a subcortical stroke 4 months previously, received 2 weeks of CIT. During the therapy, daily optical topography imaging using near-infrared light was measured serially while the participant performed a functional key-turning task. Clinical outcome measures included the Wolf Motor Function Test (WMFT), Motor Activity Log (MAL), and functional key grip test. Transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) were also used to map cortical areas and hemodynamic brain responses, respectively. Optical topography measurement showed an overall decrease in oxy-hemoglobin concentration in both hemispheres as therapy progressed and the laterality index increased toward the contralateral hemisphere. An increased TMS motor map area was observed in the contralateral cortex following treatment. Posttreatment fMRI showed bilateral primary motor cortex activation, although slightly greater in the contralateral hemisphere, during affected hand movement. Clinical scores revealed marked improvement in functional activities. In one patient who suffered a stroke, 2 weeks of CIT led to improved function and cortical reorganization in the hemisphere contralateral to the affected hand. PMID:15228805

Mental Practice Combined with Physical Practice to Enhance Hand Recovery in Stroke Patients

PubMed Central

Liu, Hua; Song, Lu-ping

2014-01-01

Objectives. To evaluate whether combining mental practice with physical practice training enhances hand function in patients with stroke. Methods. 10 for treatment and 10 for control were recruited for this pre/posttraining matched case control study. In the treatment group, subjects underwent combining mental practice with physical practice for four weeks. In the control group, subjects only participated in physical practice. Change of hand function and the number of activated voxels of the contralateral somatosensory motor cortex (SMC) acquired by functional magnetic resonance imaging were measured. Results. After training, the Action Research Arm Test score increased by 12.65 for treatment and by 5.20 for control. There was a significant difference in the Action Research Arm Test score between the two groups (P = 0.04). The activated voxels number of the contralateral SMC increased in both groups, but the activated voxels number in the contralateral SMC and the improvement of hand function for treatment were greater than for control. In the treatment group, the number of activated voxels of the contralateral SMC was positively correlated with better hand function scores. Conclusions. Combining mental practice with physical practice may be a more effective treatment strategy than physical training alone for hand recovery in stroke patients. PMID:25435713

Contralateral cerebello-thalamo-cortical pathways with prominent involvement of associative areas in humans in vivo.

PubMed

Palesi, Fulvia; Tournier, Jacques-Donald; Calamante, Fernando; Muhlert, Nils; Castellazzi, Gloria; Chard, Declan; D'Angelo, Egidio; Wheeler-Kingshott, Claudia A M

2015-11-01

In addition to motor functions, it has become clear that in humans the cerebellum plays a significant role in cognition too, through connections with associative areas in the cerebral cortex. Classical anatomy indicates that neo-cerebellar regions are connected with the contralateral cerebral cortex through the dentate nucleus, superior cerebellar peduncle, red nucleus and ventrolateral anterior nucleus of the thalamus. The anatomical existence of these connections has been demonstrated using virus retrograde transport techniques in monkeys and rats ex vivo. In this study, using advanced diffusion MRI tractography we show that it is possible to calculate streamlines to reconstruct the pathway connecting the cerebellar cortex with contralateral cerebral cortex in humans in vivo. Corresponding areas of the cerebellar and cerebral cortex encompassed similar proportion (about 80%) of the tract, suggesting that the majority of streamlines passing through the superior cerebellar peduncle connect the cerebellar hemispheres through the ventrolateral thalamus with contralateral associative areas. This result demonstrates that this kind of tractography is a useful tool to map connections between the cerebellum and the cerebral cortex and moreover could be used to support specific theories about the abnormal communication along these pathways in cognitive dysfunctions in pathologies ranging from dyslexia to autism.

Malalignment and subchondral bone turnover in contralateral knees of overweight/obese women with unilateral osteoarthritis: implications for bilateral disease.

PubMed

Mazzuca, Steven A; Brandt, Kenneth D; Lane, Kathleen A; Chakr, Rafael

2011-11-01

To explore whether the risk of incident tibiofemoral (TF) osteoarthritis (OA) in the radiographically normal contralateral knee of overweight/obese women with unilateral knee OA is mediated by malalignment and/or preceded by increased turnover of subchondral bone. We used data of post hoc analyses from a randomized controlled trial. Cross-sectional analyses evaluated the baseline association between frontal plane alignment and bone turnover in the medial TF compartment in 78 radiographically normal contralateral knees. Longitudinal analyses ascertained whether incident radiographic OA (TF osteophyte formation within 30 months) was associated with malalignment and/or increased bone turnover at baseline. Alignment subcategories (varus/neutral/valgus) were based on the anatomic axis angle. (99m)Tc-methylene diphosphonate uptake in a late-phase bone scan was quantified in regions of interest in the medial tibia (MT) and medial femur (MF) and adjusted for uptake in a reference segment of the ipsilateral tibial shaft (TS). MF and MT uptake in varus contralateral knees was 50-55% greater than in the TS. Adjusted MT uptake in varus contralateral knees was significantly greater than that in neutral and valgus contralateral knees (mean 1.55 versus 1.38 and 1.43, respectively; P < 0.05). Among 69 contralateral knees followed longitudinally, 22 (32%) developed TF OA. Varus angulation was associated with a marginally significant increase in the odds of incident OA (adjusted odds ratio 3.98, P = 0.067). While the small sample size limited our ability to detect statistically significant risk factors, these data suggest that the risk of developing bilateral TF OA in overweight/obese women may be mediated by varus malalignment. Copyright © 2011 by the American College of Rheumatology.

Microplasmin-Induced Posterior Vitreous Detachment Affects Vitreous Oxygen Levels

PubMed Central

Quiram, Polly A.; Leverenz, Victor R.; Baker, Robert M.; Dang, Loan; Giblin, Frauk J.; Trese, Michael T.

2009-01-01

Purpose To determine if enzymatic induction of a posterior vitreous detachment (PVD) and/or vitreous liquefaction affects O2 concentration in the vitreous cavity in animals with vascularized and avascular retinal circulations. Methods Either microplasmin or hyaluronidase was injected intravitreally into guinea pigs (avascular retinal circulation), brown Norway rats (vascularized retinal circulation without fovea), or cats (vascularized retinal circulation with fovea) with the contralateral eye used as a control. One to 2 weeks post injection, vitreal oxygen concentration was measured using a highly sensitive, platinum-based fluorophore O2 sensor. In addition, control and microplasmin-injected rats, guinea pigs, and cats were exposed to 100% oxygen and vitreal O2 levels were measured over time. Scanning electron microscopy (SEM) was used to evaluate the vitreoretinal interface for the presence of a PVD. Results In animals with a vascularized retinal circulation (brown Norway rats and cats), intravitreal injection of microplasmin with induction of a PVD significantly increased baseline O2 concentration in the vitreous cavity compared to hyaluronidase injected eyes and controls in rats (35, 25, and 23 mm Hg, P < 0.001 and P < 0.001, respectively) and cats (26, 18, and 16 mm Hg, P < 0.01 and P < 0.001, respectively). Interestingly, intravitreal injection of hyaluronidase (vitreous liquefaction without induction of a PVD) did not significantly increase vitreal O2 levels in any of the animal species (P > 0.1). Upon exposure to 100% oxygen by facemask, microplasmin injected animals showed a rapid increase in vitreal oxygen levels compared to hyaluronidase injected animals and controls, indicating that the presence of a PVD allows rapid O2 exchange within the vitreous cavity. Similarly, once O2 was discontinued, the O2 concentration decreased in a similarly rapid rate. SEM showed smooth retinal surfaces in microplasmin-injected cat eyes, indicating the presence of a PVD which was not present in hyaluronidase injected or control eyes. Conclusion The results suggest that enzymatic-assisted PVD with microplasmin increases vitreal O2 levels and increases the rate of O2 exchange within the vitreous cavity. PMID:18040251

Sounds Activate Visual Cortex and Improve Visual Discrimination

PubMed Central

Störmer, Viola S.; Martinez, Antigona; McDonald, John J.; Hillyard, Steven A.

2014-01-01

A recent study in humans (McDonald et al., 2013) found that peripheral, task-irrelevant sounds activated contralateral visual cortex automatically as revealed by an auditory-evoked contralateral occipital positivity (ACOP) recorded from the scalp. The present study investigated the functional significance of this cross-modal activation of visual cortex, in particular whether the sound-evoked ACOP is predictive of improved perceptual processing of a subsequent visual target. A trial-by-trial analysis showed that the ACOP amplitude was markedly larger preceding correct than incorrect pattern discriminations of visual targets that were colocalized with the preceding sound. Dipole modeling of the scalp topography of the ACOP localized its neural generators to the ventrolateral extrastriate visual cortex. These results provide direct evidence that the cross-modal activation of contralateral visual cortex by a spatially nonpredictive but salient sound facilitates the discriminative processing of a subsequent visual target event at the location of the sound. Recordings of event-related potentials to the targets support the hypothesis that the ACOP is a neural consequence of the automatic orienting of visual attention to the location of the sound. PMID:25031419

The effect of limb amputation on standing weight distribution in the remaining three limbs in dogs.

PubMed

Cole, Grayson Lee; Millis, Darryl

2017-01-16

Despite the fact that limb amputation is a commonly performed procedure in veterinary medicine, quantitative data regarding outcomes are lacking. The intention of this study was to evaluate the effect of limb amputation on weight distribution to the remaining three limbs at a stance in dogs. Ten dogs with a prior forelimb amputation and ten dogs with a prior hindlimb amputation; all of which had no history of orthopaedic or neural disease in the remaining three limbs were included in the study. Standing weight bearing was evaluated with a commercial stance analyzer in all dogs. Five valid trials were obtained and a mean percentage of weight bearing was calculated for each remaining limb. The dogs with a previous forelimb amputation, and also those with a previous hindlimb amputation, had the largest mean increase in weight bearing in the contralateral forelimb. In conclusion, proactive monitoring of orthopaedic disease in the contralateral forelimb may be advisable in dogs with a previous limb amputation. In addition, when determining candidacy for a limb amputation, disease of the contralateral forelimb should be thoroughly evaluated.

Fluorescein photodiagnosis of idiopathic retinal vasculitis, aneurysms, and neuroretinitis (IRVAN) syndrome: A case report and long-term outcome of photocoagulation therapy.

PubMed

Xia, Yonghui; Su, Yu; Wong, Ian Hin Yat; Ma, Xiaoli; Hua, Rui

2016-12-01

Idiopathic retinal vasculitis, aneurysms, and neuroretinitis (IRVAN) syndrome is a disease characterized by multiple retinal macroaneurysms, neuroretinitis and peripheral capillary non-perfusion, leading to irreversible visual loss. It includes five stages and has previously been rarely reported. IRVAN syndrome is especially rare in Asia. In this report, we describe laser diagnosis and therapy in an Asian patient with IRVAN syndrome over two years of follow-up. We observed non-perfusion retina and dilated retinal capillaries in the contralateral eye. Photocoagulation is an effective therapy to control retinal macroaneurysms and nonperfusions and to prevent visual loss, particularly in the early stages of IRVAN syndrome (stages 2 & 3). To the best of our knowledge, this is the first long-term observation of photocoagulation in IRVAN syndrome. We discovered the early signs of such lesions, which may be beneficial for clinical diagnosis and therapy. Copyright © 2016 Elsevier B.V. All rights reserved.

Evaluation of nerve transfer options for treating total brachial plexus avulsion injury: a retrospective study of 73 participants

PubMed Central

Gao, Kai-ming; Hu, Jing-jing; Lao, Jie; Zhao, Xin

2018-01-01

Despite recent great progress in diagnosis and microsurgical repair, the prognosis in total brachial plexus-avulsion injury remains unfavorable. Insufficient number of donors and unreasonable use of donor nerves might be key factors. To identify an optimal treatment strategy for this condition, we conducted a retrospective review. Seventy-three patients with total brachial plexus avulsion injury were followed up for an average of 7.3 years. Our analysis demonstrated no significant difference in elbow-flexion recovery between phrenic nerve-transfer (25 cases), phrenic nerve-graft (19 cases), intercostal nerve (17 cases), or contralateral C7-transfer (12 cases) groups. Restoration of shoulder function was attempted through anterior accessory nerve (27 cases), posterior accessory nerve (10 cases), intercostal nerve (5 cases), or accessory + intercostal nerve transfer (31 cases). Accessory nerve + intercostal nerve transfer was the most effective method. A significantly greater amount of elbow extension was observed in patients with intercostal nerve transfer (25 cases) than in those with contralateral C7 transfer (10 cases). Recovery of median nerve function was noticeably better for those who received entire contralateral C7 transfer (33 cases) than for those who received partial contralateral C7 transfer (40 cases). Wrist and finger extension were reconstructed by intercostal nerve transfer (31 cases). Overall, the recommended surgical treatment for total brachial plexus-avulsion injury is phrenic nerve transfer for elbow flexion, accessory nerve + intercostal nerve transfer for shoulder function, intercostal nerves transfer for elbow extension, entire contralateral C7 transfer for median nerve function, and intercostal nerve transfer for finger extension. The trial was registered at ClinicalTrials.gov (identifier: NCT03166033). PMID:29623932

Analysis of Surgical Freedom Variation Across the Basilar Artery Bifurcation: Towards a Deeper Insight Into Approach Selection for Basilar Apex Aneurysms.

PubMed

Tayebi Meybodi, Ali; Benet, Arnau; Rodriguez Rubio, Roberto; Yousef, Sonia; Lawton, Michael T

2018-03-03

The orbitozygomatic approach is generally advocated over the pterional approach for basilar apex aneurysms. However, the impact of the extensions of the pterional approach on the obtained maneuverability over multiple vascular targets (relevant to basilar apex surgery) has not been studied before. To analyze the patterns of surgical freedom change across the basilar bifurcation between the pterional, orbitopterional, and orbitozygomatic approaches. Surgical freedom was assessed for 3 vascular targets important in basilar apex aneurysm surgery (ipsilateral and contralateral P1-P2 junctions, and basilar apex), and compared between the pterional, orbitopterional, and orbitozygomatic approaches in 10 cadaveric specimens. Transitioning from the pterional to orbitopterional approach, the surgical freedom increased significantly at all 3 targets (P < .05). However, the gain in surgical freedom declined progressively from the most superficial target (60% for ipsilateral P1-P2 junction) to the deepest target (35% for contralateral P1-P2 junction). Conversely, transitioning from the orbitopterional to the orbitozygomatic approach, the gain in surgical freedom was minimal for the ipsilateral P1-P2 and basilar apex (<4%), but increased dramatically to 19% at the contralateral P1-P2 junction. The orbitopterional approach provides a remarkable increase in surgical maneuverability compared to the pterional approach for the basilar apex target and the relevant adjacent arterial targets. However, compared to the orbitopterional, the orbitozygomatic approach adds little maneuverability except for the deepest target (ie, contralateral P1-P2 junction). Therefore, the orbitozygomatic approach may be most efficacious with larger basilar apex aneurysms limiting the control over of the contralateral P1 PCA.

Use-Dependent Dendritic Regrowth Is Limited after Unilateral Controlled Cortical Impact to the Forelimb Sensorimotor Cortex

PubMed Central

Jones, Theresa A.; Liput, Daniel J.; Maresh, Erin L.; Donlan, Nicole; Parikh, Toral J.; Marlowe, Dana

2012-01-01

Abstract Compensatory neural plasticity occurs in both hemispheres following unilateral cortical damage incurred by seizures, stroke, and focal lesions. Plasticity is thought to play a role in recovery of function, and is important for the utility of rehabilitation strategies. Such effects have not been well described in models of traumatic brain injury (TBI). We examined changes in immunoreactivity for neural structural and plasticity-relevant proteins in the area surrounding a controlled cortical impact (CCI) to the forelimb sensorimotor cortex (FL-SMC), and in the contralateral homotopic cortex over time (3–28 days). CCI resulted in considerable motor deficits in the forelimb contralateral to injury, and increased reliance on the ipsilateral forelimb. The density of dendritic processes, visualized with immunostaining for microtubule-associated protein-2 (MAP-2), were bilaterally decreased at all time points. Synaptophysin (SYN) immunoreactivity increased transiently in the injured hemisphere, but this reflected an atypical labeling pattern, and it was unchanged in the contralateral hemisphere compared to uninjured controls. The lack of compensatory neuronal structural plasticity in the contralateral homotopic cortex, despite behavioral asymmetries, is in contrast to previous findings in stroke models. In the cortex surrounding the injury (but not the contralateral cortex), decreases in dendrites were accompanied by neurodegeneration, as indicated by Fluoro-Jade B (FJB) staining, and increased expression of the growth-inhibitory protein Nogo-A. These studies indicate that, following unilateral CCI, the cortex undergoes neuronal structural degradation in both hemispheres out to 28 days post-injury, which may be indicative of compromised compensatory plasticity. This is likely to be an important consideration in designing therapeutic strategies aimed at enhancing plasticity following TBI. PMID:22352953

Carotid Artery Stenting and Blood-Brain Barrier Permeability in Subjects with Chronic Carotid Artery Stenosis.

PubMed

Szarmach, Arkadiusz; Halena, Grzegorz; Kaszubowski, Mariusz; Piskunowicz, Maciej; Studniarek, Michal; Lass, Piotr; Szurowska, Edyta; Winklewski, Pawel J

2017-05-08

Failure of the blood-brain barrier (BBB) is a critical event in the development and progression of diseases such as acute ischemic stroke, chronic ischemia or small vessels disease that affect the central nervous system. It is not known whether BBB breakdown in subjects with chronic carotid artery stenosis can be restrained with postoperative recovery of cerebral perfusion. The aim of the study was to assess the short-term effect of internal carotid artery stenting on basic perfusion parameters and permeability surface area-product (PS) in such a population. Forty subjects (23 males) with stenosis of >70% within a single internal carotid artery and neurological symptoms who underwent a carotid artery stenting procedure were investigated. Differences in the following computed tomography perfusion (CTP) parameters were compared before and after surgery: global cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), time to peak (TTP) and PS. PS acquired by CTP is used to measure the permeability of the BBB to contrast material. In all baseline cases, the CBF and CBV values were low, while MTT and TTP were high on both the ipsi- and contralateral sides compared to reference values. PS was approximately twice the normal value. CBF was higher (+6.14%), while MTT was lower (-9.34%) on the contralateral than on the ipsilateral side. All perfusion parameters improved after stenting on both the ipsilateral (CBF +22.66%; CBV +18.98%; MTT -16.09%, TTP -7.62%) and contralateral (CBF +22.27%, CBV +19.72%, MTT -14.65%, TTP -7.46%) sides. PS decreased by almost half: ipsilateral -48.11%, contralateral -45.19%. The decline in BBB permeability was symmetrical on the ipsi- and contralateral sides to the stenosis. Augmented BBB permeability can be controlled by surgical intervention in humans.