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Sample records for ocular motor nerves

  1. Imaging the ocular motor nerves.

    PubMed

    Ferreira, Teresa; Verbist, Berit; van Buchem, Mark; van Osch, Thijs; Webb, Andrew

    2010-05-01

    The ocular motor nerves (OMNs) comprise the oculomotor, trochlear and the abducens nerves. According to their course, they are divided into four or five anatomic segments: intra-axial, cisternal, cavernous and intra-orbital and, for the abducens nerve, an additional interdural segment. Magnetic resonance imaging is the imaging method of choice in the evaluation of the normal and pathologic ocular motor nerves. CT still plays a limited but important role in the evaluation of the intraosseous portions at the skull base and bony foramina. We describe for each segment of these cranial nerves, the normal anatomy, the most appropriate image sequences and planes, their imaging appearance and pathologic conditions. Magnetic resonance imaging with high magnetic fields is a developing and promising technique. We describe our initial experience with a Phillips 7.0T MRI scanner in the evaluation of the brainstem segments of the OMNs. As imaging becomes more refined, an understanding of the detailed anatomy is increasingly necessary, as the demand on radiology to diagnose smaller lesions also increases.

  2. Microsurgical anatomy of the ocular motor nerves.

    PubMed

    Zhang, Yi; Liu, Hao; Liu, En-Zhong; Lin, You-Zhi; Zhao, Shi-Guang; Jing, Guo-Hua

    2010-08-01

    This study was designed to provide anatomic data to help surgeons avoid damage to the ocular motor nerves during intraorbital operations. The microsurgical anatomy of the ocular motor nerves was studied in 50 adult cadaveric heads (100 orbits). Dissections were performed with a microscope. The nerves were exposed and the neural and muscular relationships of each portion of the nerve were examined and measured. The superior division of the oculomotor nerve coursed between the optic nerve and the superior rectus muscle after it left the annular tendon, and its branches entered into the superior rectus muscle and levator muscle. A mean of five fibers (range 3-7) innervated the superior rectus muscle, and a mean of one fiber (range 1-2) followed a medial direction (84%) or went straight through the superior rectus muscle (16%). The inferior division of the oculomotor nerve branched into the medial rectus, inferior rectus and inferior oblique muscles. The trochlear nerve ended on the orbital side of the posterior one-third of the superior oblique muscle in 76 specimens. The abducens nerve ended on the posterior one-third of the lateral rectus muscle in 86 specimens. If the belly of the lateral rectus muscle was divided into three superior-inferior parts, the nerve commonly entered into the middle one-third in 74 specimens. Based on the observed data, microanatomical relationships of the orbital contents were revised.

  3. Intraoperative Electrophysiologic Monitoring of Ocular Motor Nerves Under Conditions of Partial Neuromuscular Blockade During Skull Base Surgery

    PubMed Central

    Kawaguchi, Masahiko; Ohnishi, Hideyuki; Sakamoto, Takanori; Shimizu, Kiyoshi; Karasawa, Jun; Furuya, Hitoshi

    1996-01-01

    The feasibility and usefulness of intraoperative electromyographic monitoring of the oculomotor nerve (CN III), trochlear nerve (CN IV), and abducens nerve (CN IV) were evaluated under conditions of partial neuromuscular blockade in 21 patients undergoing skill base surgery. Intracranial electrical stimulation of each nerve was performed, and compound muscle action potentials (CMAPs) were reconded from the inferior or superior rectus muscle, the superior oblique muscle, and the lateral rectus muscle for monitoring of CN III, IV, and VI, respectively. Partial neuromuscular blockade was achieved by controlled infusion of vecuronium titrated to eliminate about 90% of the twitch response of the abductor pollicis brevis to electrical stimulation of the median nerve. A total of 30 cranial nerves were stimulated intraoperatively. Of these, 29 were successfully monitored (19 CN III, 6 CN IV, 4 CN VI). A relationship was found between intraoperative findings of cranial nerve monitoring, such as disappearance of response and increase in latency and stimulus threshold during manipulation of a lesion, and the presence of postoperative nerve deficits. We conclude that intraoperative electromyographic monitoring of ocular motor nerves is feasible during partial neuromuscular blockade, and that partial neuromuscular blockade does not affect the relationship between findings of intraoperative monitoring and postoperative nerve function. PMID:17170948

  4. Severity of infantile nystagmus syndrome-like ocular motor phenotype is linked to the extent of the underlying optic nerve projection defect in zebrafish belladonna mutant.

    PubMed

    Huber-Reggi, Sabina P; Chen, Chien-Cheng; Grimm, Lea; Straumann, Dominik; Neuhauss, Stephan C F; Huang, Melody Ying-Yu

    2012-12-12

    Infantile nystagmus syndrome (INS), formerly known as congenital nystagmus, is an ocular motor disorder in humans characterized by spontaneous eye oscillations (SOs) and, in several cases, reversed optokinetic response (OKR). Its etiology and pathomechanism is largely unknown, but misrouting of the optic nerve has been observed in some patients. Likewise, optic nerve misrouting, a reversed OKR and SOs with INS-like waveforms are observed in zebrafish belladonna (bel) mutants. We aimed to investigate whether and how misrouting of the optic nerve correlates with the ocular motor behaviors in bel larvae. OKR and SOs were quantified and subsequently the optic nerve fibers were stained with fluorescent lipophilic dyes. Eye velocity during OKR was reduced in larvae with few misprojecting optic nerve fibers and reversed in larvae with a substantial fraction of misprojecting fibers. All larvae with reversed OKR also displayed SOs. A stronger reversed OKR correlated with more frequent SOs. Since we did not find a correlation between additional retinal defects and ocular motor behavior, we suggest that axon misrouting is in fact origin of INS in the zebrafish animal model. Depending on the ratio between misprojecting ipsilateral and correctly projecting contralateral fibers, the negative feedback loop normally regulating OKR can turn into a positive loop, resulting in an increase in retinal slip. Our data not only give new insights into the etiology of INS but may also be of interest for studies on how the brain deals with and adapts to conflicting inputs.

  5. Medial medullary infarction: abnormal ocular motor findings.

    PubMed

    Kim, J Soo; Choi, K-D; Oh, S-Y; Park, S-H; Han, M-K; Yoon, B-W; Roh, J-K

    2005-10-25

    In 20 consecutive patients with isolated medial medullary infarction, abnormal ocular motor findings included nystagmus (n = 8), ocular contrapulsion (n = 5), and contralesional ocular tilt reaction (n = 2). The nystagmus was ipsilesional (n = 4), gaze-evoked (n = 5), upbeating (n = 4), and hemiseesaw (n = 1). The ocular motor abnormalities may be explained by involvements of the nucleus prepositus hypoglossi, medial longitudinal fasciculus or efferent fibers from the vestibular nuclei, climbing fibers, and cells of the paramedian tracts.

  6. Ocular Motor Manifestations of Multiple Sclerosis.

    PubMed

    Nerrant, Elodie; Tilikete, Caroline

    2017-09-01

    Multiple sclerosis (MS) is a demyelinating disease of the central nervous system leading to disability, especially in young patients. Acute or chronic lesions of MS within the brainstem and the cerebellum frequently result in ocular motor disorders. This review encompasses the spectrum of ocular motor disorders in patients with MS emphasizing prevalence, examination findings, diagnostic features, functional consequences, classification of MS course, and management of these disturbances of ocular motility. Ocular motor manifestations of MS can occur acutely in relapse or chronically, the latter as a consequence of previous relapses or as a chronic course of the disease. The most frequent and specific acute ocular motor manifestation is uni- or bilateral internuclear ophthalmoplegia (INO). The most frequent chronic manifestations include INO and cerebellar ocular motor disorders such as gaze-evoked nystagmus, saccadic hypermetria, and lack of vestibulo-ocular reflex inhibition. The most disabling syndrome is pendular nystagmus. The high prevalence of ocular motor manifestations emphasizes the importance of neuro-ophthalmological examination among patients with MS. Because chronic manifestations may cause minimal or no symptoms, a systematic investigation of the most common manifestations should be performed in daily practice. Appropriate treatment may improve visual outcome in some of these ocular motor disorders.

  7. Rehabilitation following motor nerve transfers.

    PubMed

    Novak, Christine B

    2008-11-01

    Cortical mapping and relearning are key factors in optimizing patient outcome following motor nerve transfers. To maximize function following nerve transfers, the rehabilitation program must include motor reeducation to initiate recruitment of the weak reinnervated muscles and to establish new motor patterns and cortical mapping. Patient education and a home program are essential to obtain the optimal functional result.

  8. Ocular Motor Function in Children with Spastic Hemiplegia Evaluated by the Ocular Motor Score.

    PubMed

    Rydberg, A; Ygge, J; Olsson, M

    2017-08-03

    To assess the ocular motor functions in children with spastic hemiplegia by using the Ocular Motor Score (OMS). This study included 34 children, median age 11 years. The children were divided into 3 groups according to the underlying brain lesion; group 1 malformations, group 2 white matter damage of immaturity (WMDI), and group 3 cortical/subcortical lesions. The OMS protocol consists of 15 different subtests evaluating ocular motor functions. The OMS is divided into 2 parts, a static and a dynamic. The results from each subtest are scored 0, 0.3, 0.5, or 1, according to the level of disturbance, where 0 corresponds to normal function and 1 represents the maximum disability in the certain subtest. A total OMS (tOMS) between 0 and 15 can be obtained. The median tOMS in the whole spastic hemiplegia group was 2.5 (range 1.3-5.8). The highest median tOMS 5.2 was seen in group 1, in the children with malformations. Strabismus was found in 45% (15/34) of the children, with an equal percentage in all 3 groups. The children with spastic hemiplegia had a median tOMS of 2.7 and the highest median tOMS was seen in children with malformations. The OMS protocol is easy to use clinically and gives a quick overview of the patient´s ocular motor functions.

  9. Albinism: particular attention to the ocular motor system.

    PubMed

    Hertle, Richard W

    2013-01-01

    The purpose of this report is to summarize an understanding of the ocular motor system in patients with albinism. Other than the association of vertical eccentric gaze null positions and asymmetric, (a) periodic alternating nystagmus in a large percentage of patients, the ocular motor system in human albinism does not contain unique pathology, rather has "typical" types of infantile ocular oscillations and binocular disorders. Both the ocular motor and afferent visual system are affected to varying degrees in patients with albinism, thus, combined treatment of both systems will maximize visual function.

  10. Albinism: Particular Attention to the Ocular Motor System

    PubMed Central

    Hertle, Richard W.

    2013-01-01

    The purpose of this report is to summarize an understanding of the ocular motor system in patients with albinism. Other than the association of vertical eccentric gaze null positions and asymmetric, (a) periodic alternating nystagmus in a large percentage of patients, the ocular motor system in human albinism does not contain unique pathology, rather has “typical” types of infantile ocular oscillations and binocular disorders. Both the ocular motor and afferent visual system are affected to varying degrees in patients with albinism, thus, combined treatment of both systems will maximize visual function. PMID:24014991

  11. Mechanics of mouse ocular motor plant quantified by optogenetic techniques

    PubMed Central

    Thumser, Zachary C.; May, Paul J.; Andrade, Francisco H.; Anderson, Sean R.; Dean, Paul

    2015-01-01

    Rigorous descriptions of ocular motor mechanics are often needed for models of ocular motor circuits. The mouse has become an important tool for ocular motor studies, yet most mechanical data come from larger species. Recordings of mouse abducens neurons indicate the mouse mechanics share basic viscoelastic properties with larger species but have considerably longer time constants. Time constants can also be extracted from the rate at which the eye re-centers when released from an eccentric position. The displacement can be accomplished by electrically stimulating ocular motor nuclei, but electrical stimulation may also activate nearby ocular motor circuitry. We achieved specific activation of abducens motoneurons through photostimulation in transgenic mice expressing channelrhodopsin in cholinergic neurons. Histology confirmed strong channelrhodopsin expression in the abducens nucleus with relatively little expression in nearby ocular motor structures. Stimulation was delivered as 20- to 1,000-ms pulses and 40-Hz trains. Relaxations were modeled best by a two-element viscoelastic system. Time constants were sensitive to stimulus duration. Analysis of isometric relaxation of isolated mouse extraocular muscles suggest the dependence is attributable to noninstantaneous decay of active forces in non-twitch fibers following stimulus offset. Time constants were several times longer than those obtained in primates, confirming that the mouse ocular motor mechanics are relatively sluggish. Finally, we explored the effects of 0.1- to 20-Hz sinusoidal photostimuli and demonstrated their potential usefulness in characterizing ocular motor mechanics, although this application will require further data on the temporal relationship between photostimulation and neuronal firing in extraocular motoneurons. PMID:26108953

  12. Mechanics of mouse ocular motor plant quantified by optogenetic techniques.

    PubMed

    Stahl, John S; Thumser, Zachary C; May, Paul J; Andrade, Francisco H; Anderson, Sean R; Dean, Paul

    2015-09-01

    Rigorous descriptions of ocular motor mechanics are often needed for models of ocular motor circuits. The mouse has become an important tool for ocular motor studies, yet most mechanical data come from larger species. Recordings of mouse abducens neurons indicate the mouse mechanics share basic viscoelastic properties with larger species but have considerably longer time constants. Time constants can also be extracted from the rate at which the eye re-centers when released from an eccentric position. The displacement can be accomplished by electrically stimulating ocular motor nuclei, but electrical stimulation may also activate nearby ocular motor circuitry. We achieved specific activation of abducens motoneurons through photostimulation in transgenic mice expressing channelrhodopsin in cholinergic neurons. Histology confirmed strong channelrhodopsin expression in the abducens nucleus with relatively little expression in nearby ocular motor structures. Stimulation was delivered as 20- to 1,000-ms pulses and 40-Hz trains. Relaxations were modeled best by a two-element viscoelastic system. Time constants were sensitive to stimulus duration. Analysis of isometric relaxation of isolated mouse extraocular muscles suggest the dependence is attributable to noninstantaneous decay of active forces in non-twitch fibers following stimulus offset. Time constants were several times longer than those obtained in primates, confirming that the mouse ocular motor mechanics are relatively sluggish. Finally, we explored the effects of 0.1- to 20-Hz sinusoidal photostimuli and demonstrated their potential usefulness in characterizing ocular motor mechanics, although this application will require further data on the temporal relationship between photostimulation and neuronal firing in extraocular motoneurons.

  13. Deficient FGF signaling causes optic nerve dysgenesis and ocular coloboma.

    PubMed

    Cai, Zhigang; Tao, Chenqi; Li, Hongge; Ladher, Raj; Gotoh, Noriko; Feng, Gen-Sheng; Wang, Fen; Zhang, Xin

    2013-07-01

    FGF signaling plays a pivotal role in eye development. Previous studies using in vitro chick models and systemic zebrafish mutants have suggested that FGF signaling is required for the patterning and specification of the optic vesicle, but due to a lack of genetic models, its role in mammalian retinal development remains elusive. In this study, we show that specific deletion of Fgfr1 and Fgfr2 in the optic vesicle disrupts ERK signaling, which results in optic disc and nerve dysgenesis and, ultimately, ocular coloboma. Defective FGF signaling does not abrogate Shh or BMP signaling, nor does it affect axial patterning of the optic vesicle. Instead, FGF signaling regulates Mitf and Pax2 in coordinating the closure of the optic fissure and optic disc specification, which is necessary for the outgrowth of the optic nerve. Genetic evidence further supports that the formation of an Frs2α-Shp2 complex and its recruitment to FGF receptors are crucial for downstream ERK signaling in this process, whereas constitutively active Ras signaling can rescue ocular coloboma in the FGF signaling mutants. Our results thus reveal a previously unappreciated role of FGF-Frs2α-Shp2-Ras-ERK signaling axis in preventing ocular coloboma. These findings suggest that components of FGF signaling pathway may be novel targets in the diagnosis of and the therapeutic interventions for congenital ocular anomalies.

  14. Lyme neuroborreliosis: a treatable cause of acute ocular motor disturbances in children.

    PubMed

    Correll, M H; Datta, N; Arvidsson, H S S; Melsom, H A; Thielberg, A K; Bjerager, M; Brodsky, M C; Saunte, J P

    2015-10-01

    Lyme neuroborreliosis (LNB) designates central nervous system involvement caused by the tick-borne spirochaete Borrelia burgdorferi (Bb). The present study describes a spectrum of acquired ocular motor disorders in children with LNB. Six paediatric patients (age 3-15 years) with ocular motor symptoms as first manifestations of LNB evaluated by a paediatrician and ophthalmologist are presented. Diagnosis was based on new onset ocular motor disturbances and detection of cerebrospinal fluid (CSF) pleocytosis and intrathecal synthesis of Bb IgM and/or IgG antibodies by lumbar puncture. The children were evaluated before and after antibiotic treatment with a follow-up time of 1-7 months. Videos were obtained both pre and post treatment in four patients. Two children presented with acquired nystagmus, one with combined nystagmus and partial sixth nerve palsy, one with partial sixth nerve palsy, one with ptosis and one with Adie's pupil. Five of the patients presented with severe fatigue, malaise, nausea, headache and fever. Four had recognised a tick bite recently, and two developed erythema migrans. Intrathecal synthesis of IgM and/or IgG antibodies specific for Bb was positive in all children, and five showed CSF pleocytosis. Cerebral MRI or CT of the brain were normal. Treatment with intravenous or oral antibiotics produced rapid clinical improvement in five of the six children. LNB can present as acute ocular motor disorders in conjunction with fatigue and other clinical manifestations. In endemic areas, children with unexplained, acquired ocular motor abnormalities should be evaluated for LNB, a treatable medical condition. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  15. The functional organization of motor nerve terminals.

    PubMed

    Slater, Clarke R

    2015-11-01

    Neuromuscular junctions (NMJs) have long been studied as particularly accessible examples of chemical synapses. Nonetheless, some important features of neuromuscular transmission are still poorly understood. One of these is the low statistical variability of the number of transmitter quanta released from motor nerve terminals by successive nerve impulses. This variability is well-described by a binomial distribution, suggesting that the quanta released are drawn, at high probability, from a small subset of those in the terminals. However, the nature of that subset remains unclear. In an effort to clarify what is understood, and what is not, about quantal release at NMJs, this review addresses the relationship between NMJ structure and function. After setting the biological context in which NMJs operate, key aspects of the variability of release and the structure of the motor nerve terminals are described. These descriptions are then used to explore the functional logic of motor nerve terminal organization and the structural basis of the low variability of release. This analysis supports the suggestion that the probability of release differs significantly at the different 'active zones' from which quanta are released. Finally, after a brief consideration of how release is maintained in the long term, a comparison is made of the features of NMJs with those of some well-studied neuronal synapses. An important conclusion is that NMJs share some important features with neuronal synapses, so continuing efforts to understand how motor nerve terminals work are likely to have much more general implications. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Relationship between Reinforcement and Eye Movements during Ocular Motor Training with Learning Disabled Children.

    ERIC Educational Resources Information Center

    Punnett, Audrey F.; Steinhauer, Gene D.

    1984-01-01

    Four reading disabled children were given eight sessions of ocular motor training with reinforcement and eight sessions without reinforcement. Two reading disabled control Ss were treated similarly but received no ocular motor training. Results demonstrated that reinforcement can improve ocular motor skills, which in turn elevates reading…

  17. Ocular motor signatures of cognitive dysfunction in multiple sclerosis.

    PubMed

    Fielding, Joanne; Clough, Meaghan; Beh, Shin; Millist, Lynette; Sears, Derek; Frohman, Ashley N; Lizak, Nathaniel; Lim, Jayne; Kolbe, Scott; Rennaker, Robert L; Frohman, Teresa C; White, Owen B; Frohman, Elliot M

    2015-11-01

    The anatomical and functional overlap between ocular motor command circuitry and the higher-order networks that form the scaffolding for cognition makes for a compelling hypothesis that measures of ocular motility could provide a means to sensitively interrogate cognitive dysfunction in people with multiple sclerosis (MS). Such an approach may ultimately provide objective and reproducible measures of cognitive dysfunction that offer an innovative capability to refine diagnosis, improve prognostication, and more accurately codify disease burden. A further dividend may be the validation and application of biomarkers that can be used in studies aimed at identifying and monitoring preventative, protective and even restorative properties of novel neurotherapeutics in MS. This Review discusses the utility of ocular motor measures in patients with MS to characterize disruption to wide-ranging networks that support cognitive function.

  18. Ocular motor features of alternating hemiplegia of childhood.

    PubMed

    Egan, Robert A

    2002-06-01

    A 14-month-old boy with alternating hemiplegia of childhood, an idiopathic disorder of early childhood causing episodic hemibody tonic spasms and hemiplegia, showed repetitive jerks of abduction of the ipsilateral eye during the spells. The mechanism of this ocular motor abnormality is unknown but may be unique to this disorder.

  19. Ocular Motor Score (OMS): a clinical tool to evaluating ocular motor functions in children. Intrarater and inter-rater agreement.

    PubMed

    Olsson, Monica; Teär Fahnehjelm, Kristina; Rydberg, Agneta; Ygge, Jan

    2015-08-01

    Ocular motor score (OMS) is a new clinical test protocol for evaluating ocular motor functions in children and young adults. OMS is a set of 15 important and relevant non-invasive ocular motor function parameters derived from clinical practice. The aim of the study was to evaluate OMS according to intrarater and inter-rater agreement. Forty children aged 4-10 years, 23 girls median age 6.5 (range 4.3-9.3) and 17 boys median age 5.8 (range 4.1-9.8) were included. The ocular motor functions were assessed and scored according to the OMS protocol. The examinations were videotaped. To obtain the intrarater agreement, the first author examined and scored the children twice, first in the clinic and 2 weeks later by watching the videotape. To obtain the inter-rater agreement, three other raters independently scored the ocular motor function of the children by watching the videotapes. The overall observed intrarater agreement was 88%, and the observed inter-rater agreement between the three raters was 80%. For none of the subtests was there an observed intrarater agreement lower than 65%. Three of the subtests had an observed inter-rater agreement of 65% or below. Overall there was high observed intra- and inter-rater agreement for the OMS test protocol. Subtests such as saccades and smooth pursuit were more difficult for raters to score similarly according the clinical OMS test protocol. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  20. Platysma Motor Nerve Transfer for Restoring Marginal Mandibular Nerve Function

    PubMed Central

    Jensson, David; Weninger, Wolfgang J.; Schmid, Melanie; Meng, Stefan; Tzou, Chieh-Han John

    2016-01-01

    Background: Injuries of the marginal mandibular nerve (MMN) of the facial nerve result in paralysis of the lower lip muscle depressors and an asymmetrical smile. Nerve reconstruction, when possible, is the method of choice; however, in cases of long nerve gaps or delayed nerve reconstruction, conventional nerve repairs may be difficult to perform or may provide suboptimal outcomes. Herein, we investigate the anatomical technical feasibility of transfer of the platysma motor nerve (PMN) to the MMN for restoration of lower lip function, and we present a clinical case where this nerve transfer was successfully performed. Methods: Ten adult fresh cadavers were dissected. Measurements included the number of MMN and PMN branches, the maximal length of dissection of the PMN from the parotid, and the distance from the anterior border of the parotid to the facial artery. The PMN reach for direct coaptation to the MMN at the level of the crossing with the facial artery was assessed. We performed histomorphometric analysis of the MMN and PMN branches. Results: The anatomy of the MMN and PMN was consistent in all dissections, with an average number of subbranches of 1.5 for the MMN and 1.2 for the PMN. The average maximal length of dissection of the PMN was 46.5 mm, and in every case, tension-free coaptation with the MMN was possible. Histomorphometric analysis demonstrated that the MMN contained an average of 3,866 myelinated fiber counts per millimeter, and the PMN contained 5,025. After a 3-year follow-up of the clinical case, complete recovery of MMN function was observed, without the need of central relearning and without functional or aesthetic impairment resulting from denervation of the platysma muscle. Conclusions: PMN to MMN transfer is an anatomically feasible procedure for reconstruction of isolated MMN injuries. In our patient, by direct nerve coaptation, a faster and full recovery of lower lip muscle depressors was achieved without the need of central

  1. Lyin’ Eyes: Ocular-motor Measures of Reading Reveal Deception

    PubMed Central

    Cook, Anne E.; Hacker, Douglas J.; Webb, Andrea K.; Osher, Dahvyn; Kristjansson, Sean; Woltz, Dan J.; Kircher, John C.

    2013-01-01

    Our goal was to evaluate an alternative to current methods for detecting deception in security screening contexts. We evaluated a new cognitive-based test of deception that measured participants’ ocular-motor responses (pupil responses and reading behaviors) while they read and responded to statements on a computerized questionnaire. In Experiment 1, participants from a university community were randomly assigned to either a “guilty” group that committed one of two mock crimes or an “innocent” group that only learned about the crime. Participants then reported for testing, where they completed the computer-administered questionnaire that addressed their possible involvement in the crimes. Experiment 2 also manipulated participants’ incentive to pass the test and difficulty of statements on the test. In both experiments, guilty participants had increased pupil responses to statements answered deceptively; however, they spent less time fixating on, reading, and re-reading those statements than statements answered truthfully. These ocular-motor measures were optimally weighted in a discrimination function that correctly classified 85% of participants as either guilty or innocent. Findings from Experiment 2 indicated that group discrimination was improved with greater incentives to pass the test and the use of statements with simple syntax. The present findings suggest that two cognitive processes are involved in deception -- vigilance and strategy -- and that these processes are reflected in different ocular-motor measures. The ocular-motor test reported here represents a new approach to detecting deception that may fill an important need in security screening contexts. PMID:22545928

  2. A Supranuclear Disorder of Ocular Motility as a Rare Initial Presentation of Motor Neurone Disease.

    PubMed

    Yu-Wai-Man, C; Petheram, K; Davidson, A W; Williams, T; Griffiths, P G

    2011-01-01

    A case is described of motor neurone disease presenting with an ocular motor disorder characterised by saccadic intrusions, impaired horizontal and vertical saccades, and apraxia of eyelid opening. The occurrence of eye movement abnormalities in motor neurone disease is discussed.

  3. Medical treatment of nystagmus and ocular motor disorders.

    PubMed

    Carlow, T J

    1986-01-01

    An increased compendium of drugs useful in ocular motor system dysfunction has expanded our capacity to treat selected ocular motility disorders. Adjunctive therapeutic modes (e.g., Fresnel prisms and orthoptic exercises) can also be beneficial. PAN and see-saw nystagmus can be treated with baclofen. Downbeat nystagmus may respond to clonazepam therapy, and prisms may help if the nystagmus can be modified with convergence. Congenital nystagmus may respond minimally to drugs (e.g., baclofen), but prisms or surgical procedures, or both, are still the primary treatment modalities. Innovar may be helpful in patients with severe, incapacitating vestibular disorders, and scopolamine alone or in combination with promethazine may be beneficial in patients with milder ambulatory acute peripheral vestibular disorders. Benign positional vertigo is best treated initially with positional exercises before drug therapy is instituted. Opsoclonus and ocular flutter have been treated successfully with corticosteroids, propranolol, and clonazepam, while microflutter, an extremely rare disorder, can resolve with baclofen. Although therapy with carbamazepine, 5-hydroxtryptophan, and scopolamine has been useful in selected patients with ocular palatal myoclonus, most do not respond to drug treatment. It is not usually necessary to treat voluntary nystagmus, but Fresnel prism lenses should be remembered in refractory patients. Potentially reversible and pseudointernuclear ophthalmoplegias also were discussed. Orthoptic exercises can be beneficial in posttraumatic internuclear ophthalmoplegia. Selected supranuclear palsies can be improved completely with the proper drug regimen. Lastly, superior oblique myokymia can be treated successfully with carbamazepine, with tight surveillance for possible adverse side effects. Descriptive phenomenology and pathophysiological localization must be correlated with brain stem neurochemistry and neuropharmacology to medically treat additional ocular

  4. Does the addition of a nerve wrap to a motor nerve repair affect motor outcomes?

    PubMed

    Lee, Joo-Yup; Parisi, Thomas J; Friedrich, Patricia F; Bishop, Allen T; Shin, Alexander Y

    2014-10-01

    The purpose of this study was to evaluate the effect of wrapping bioabsorbable nerve conduit around primary suture repair on motor nerve regeneration in a rat model. Forty rats were randomly divided into two experimental groups according to the type of repair of the rat sciatic nerve: group I had primary suture repair; group II had primary suture repair and bioabsorbable collagen nerve conduit (NeuraGen® 1.5 mm, Integra LifeSciences Corp., Plainsboro, NJ) wrapped around the repair. At 12 weeks, no significant differences in the percentage of recovery between the two groups were observed with respect to compound muscle action potentials, isometric muscle force, and muscle weight (P = 0.816, P = 0.698, P = 0.861, respectively). Histomorphometric analysis as compared to the non-operative sites was also not significantly different between the two groups in terms of number of myelinated axons, myelinated fiber area, and nerve fiber density (P = 0.368, P = 0.968, P = 0.071, respectively). Perineural scar tissue formation was greater in primary suture repair group (0.36 ± 0.15) than in primary repair plus conduit wrapping group (0.17 ± 0.08). This difference was statistically significant (P < 0.001). Wrapping bioabsorbable nerve conduit around primary nerve repair can decrease perineural scar tissue formation. Although the scar-decreasing effect of bioabsorbable nerve wrap does not translate into better motor nerve recovery in this study, it might have an effect on the functional outcome in humans where scar formation is much more evident than in rats.

  5. Infantile-onset saccade initiation delay (congenital ocular motor apraxia).

    PubMed

    Salman, Michael S

    2015-05-01

    Infantile-onset saccade initiation delay, also known as congenital ocular motor apraxia, typically presents in early infancy with horizontal head thrusts once head control is achieved. Defective initiation of horizontal saccades and saccade hypometria with normal saccadic velocity are characteristic findings. Isolated impairment of vertical saccades is rare. Impaired smooth ocular pursuit may be seen. Other relatively common features include developmental delay, hypotonia, ataxia, or clumsiness. Brain MRI may be normal or show a diverse range of abnormalities, most commonly involving the cerebellum. Defective slow phases of the optokinetic response are commonly associated with brain MRI abnormalities. Isolated defect of vertical saccade initiation may indicate supratentorial brain abnormalities on MRI. Joubert syndrome, a developmental midbrain-hindbrain malformation, and ataxia telangiectasia are both commonly associated with defective volitional and reflexive saccade initiation, saccade hypometria, and head thrusts. Both horizontal and vertical saccades are impaired in these two disorders.

  6. Ocular Motor and Sensory Function in Parkinson Disease

    PubMed Central

    Almer, Zina; Klein, Kathyrn S.; Marsh, Laura; Gerstenhaber, Melissa; Repka, Michael X.

    2011-01-01

    Purpose To evaluate the effect of dopaminergic medication and deep brain stimulation on ocular function in Parkinson disease (PD) and to measure vision-related quality of life in subjects with PD. Design Prospective comparative case series. Participants and Controls Twenty-seven PD and 16 control subjects were recruited. Methods We measured visual acuity, ocular motor function, convergence, and vision-related quality of life using the Visual Function Questionnaire–25 (VFQ-25). Visual sensory and motor measurements were made during the “on” and “off” states of PD dopaminergic treatment. Main Outcome Measures Convergence ability and vision related quality of life. Results The PD subjects had a mean age of 58.8 years; 30% were female. Their mean duration of PD was 10.9 ± 6.8 years. The control subjects had a mean age of 61.6 years; 56% were female. There was no difference in visual acuity, contrast sensitivity or color vision of the PD subjects in their “on” state compared with controls. Convergence amplitudes measured with base-out prism were significantly poorer in PD subjects compared with controls (24.1 ± 8 Δ vs 14.8 ±10.3 Δ; P=0.003). The mean composite VFQ-25 score was significantly worse in the PD subjects compared with the controls (87.1 ± 8.69 vs 96.6 ± 3.05; P=0.0001). Comparing the PD subjects in their “on” with their “off” states, there was no difference in distance exodeviation, near exodeviation or ocular ductions. Mean convergence amplitudes and near point of convergence were better in the “on” state compared with the “off” state, 14.8±10.3 Δ vs 10.7±9.0 Δ, (P=0.0006), and 13.1±9.1 cm vs 18.1±12.2, (P=0.002), respectively. Conclusions Convergence ability is significantly poorer in PD subjects in both their “on” and “off” states compared with controls, but significantly improves with systemic dopaminergic treatment. Ocular motor function in PD subjects fluctuates in response to treatment, which

  7. Current Treatment of Vestibular, Ocular Motor Disorders and Nystagmus

    PubMed Central

    Brandt, Thomas

    2009-01-01

    Vertigo and dizziness are among the most common complaints with a lifetime prevalence of about 30%. The various forms of vestibular disorders can be treated with pharmacological therapy, physical therapy, psychotherapeutic measures or, rarely, surgery. In this review, the current pharmacological treatment options for peripheral and central vestibular, cerebellar and ocular motor disorders will be described. They are as follows for peripheral vestibular disorders. In vestibular neuritis recovery of the peripheral vestibular function can be improved by treatment with oral corticosteroids. In Menière's disease a recent study showed long-term high-dose treatment with betahistine has a significant effect on the frequency of the attacks. The use of aminopyridines introduced a new therapeutic principle in the treatment of downbeat and upbeat nystagmus and episodic ataxia type 2 (EA 2). These potassium channel blockers presumably increase the activity and excitability of cerebellar Purkinje cells, thereby augmenting the inhibitory influence of these cells on vestibular and cerebellar nuclei. A few studies showed that baclofen improves periodic alternating nystagmus, and gabapentin and memantine, pendular nystagmus. However, many other eye movement disorders such as ocular flutter opsoclonus, central positioning, or see-saw nystagmus are still difficult to treat. Although progress has been made in the treatment of vestibular neuritis, downbeat and upbeat nystagmus, as well as EA 2, state-of-the-art trials must still be performed on many vestibular and ocular motor disorders, namely Menière's disease, bilateral vestibular failure, vestibular paroxysmia, vestibular migraine, and many forms of central eye movement disorders. PMID:21179531

  8. Two-level motor nerve transfer for the treatment of long thoracic nerve palsy.

    PubMed

    Ray, Wilson Z; Pet, Mitchell A; Nicoson, Michael C; Yee, Andrew; Kahn, Lorna C; Mackinnon, Susan E

    2011-10-01

    The authors report a case of long thoracic nerve (LTN) palsy treated with two-level motor nerve transfers of a pectoral fascicle of the middle trunk, and a branch of the thoracodorsal nerve. This procedure resulted in near-total improvement of the winged scapula deformity, and a return of excellent shoulder function. A detailed account of the postoperative physical therapy regimen is included, as this critical component of the favorable result cannot be overlooked. This case establishes the two-level motor nerve transfer as a new option for treating LTN palsy, and demonstrates that nerve transfers should be considered in the therapeutic algorithm of an idiopathic mononeuritis.

  9. Decreased Ocular Pulse Amplitude and Retinal Nerve Fibre Layer in Multiple Sclerosis

    PubMed Central

    Cetin, Ebru N.; Erdogan, Cagdas; Acer, Semra; Sarac, Gülden; Yıldırım, Cem; Bir, Levent S.

    2013-01-01

    Abstract This study was conducted to assess ocular pulse amplitude and retinal nerve fibre layer in patients with multiple sclerosis and their correlation with disease duration and with severity. Retinal nerve fibre layer thickness was measured by Heidelberg Retinal Tomography II (HRT-II; Heidelberg Engineering, Dossenheim, Germany) and ocular pulse amplitude was measured by dynamic contour tonometry (Ziemer Ophthalmic Systems, Port, Switzerland) in 37 multiple sclerosis patients and 72 age- and gender-matched controls. Ocular pulse amplitude was significantly reduced and retinal nerve fibre layer was significantly thinner in temporal, superotemporal, and nasal sectors in patients with multiple sclerosis regardless of having an optic neuritis attack. The retinal nerve fibre layer was thinner in eyes with a previous optic neuritis attack compared with the eyes without an attack, but the difference was not significant. Ocular pulse amplitude showed a positive correlation with visual evoked potential amplitude and a negative correlation with visual evoked potential latency. Retinal nerve fibre layer thickness showed a significant negative correlation with the disease duration but not with visually evoked potential, disease severity, nor previous optic neuritis. These findings indicate that the process of degeneration starts in the early period of the disease, as our study group is composed of early–middle-stage multiple sclerosis patients, and is independent of relapses. PMID:28163762

  10. Repair of ocular-oral synkinesis of postfacial paralysis using cross-facial nerve grafting.

    PubMed

    Zhang, Bo; Yang, Chuan; Wang, Wei; Li, Wei

    2010-08-01

    We present the surgical techniques and results of cross-facial nerve grafting that have been developed in the repair of ocular-oral synkinesis after facial paralysis. Eleven patients with ocular-oral synkinesis after facial paralysis underwent the cross-facial nerve grafting with facial nerve transposition at a tertiary academic hospital between 2003 and 2009. The patient selection for the study was based on the degree of disfigurement and facial function parameter rating using the Toronto Facial Grading System. The procedures used were surgeries done in two stages. All cases were followed up for 2 months to 6 years after the second surgery. The degree of improvement was evaluated at 6 to 7 months after the procedures. Six of the patients were followed up for more than 2 years after the stage-two surgery and demonstrated significant reduction in the ocular-oral synkinetic movements. The Toronto Facial Grading System scores from the postoperative follow-ups increased an average of 16 points (28%), and the patients had achieved symmetrical facial movement. We concluded that cross-facial nerve grafting with facial nerve branch transposition is effective and can be considered as an option for the repair of ocular-oral synkinesis after facial paralysis in select patients.

  11. Intermittent horizontal saccade failure ('ocular motor apraxia') in children.

    PubMed Central

    Harris, C M; Shawkat, F; Russell-Eggitt, I; Wilson, J; Taylor, D

    1996-01-01

    BACKGROUND: Ocular motor apraxia (OMA) in childhood is a poorly understood condition involving a failure of horizontal saccades. OMA is thought to be rare but the literature indicates wide clinical associations. OMA is often identified by abnormal head movements, but failure of reflexive quick phases has been reported in all but a few patients. The extent of this oculomotor disorder was examined in a large group of children with diverse clinical backgrounds. METHODS: The degree of quick phase failure during horizontal vestibular and optokinetic nystagmus was measured using DC electro-oculography and video in 74 affected children, aged 17 days to 14 years. RESULTS: All children showed an intermittent failure of nystagmic quick phases, except for total failure in one case. Other visuomotor abnormalities were common including saccadic hypometria (85%), low gain smooth pursuit (70%), neurological nystagmus (28%), strabismus (22%), and vertical abnormalities (11%). Non-ocular abnormalities were common including infantile hypotonia (61%), motor delay (77%), and speech delay (87%). There was a wide range of clinical associations including agenesis of the corpus callosum, Joubert syndrome, Dandy-Walker malformation, microcephaly, hydrocephalus, vermis hypoplasia, porencephalic cyst, megalocephaly, Krabbe leucodystrophy, Pelizaeus Merzbacher disease, infantile Gaucher disease, GM1 gangliosidosis, infantile Refsum's disease, propionic acidaemia, ataxia telangiectasia, Bardet-Biedl syndrome, vermis astrocytoma, vermis cyst, carotid fibromuscular hypoplasia, Cornelia de Lange syndrome, and microphthalmos. Perinatal and postnatal problems were found in 15% including perinatal hypoxia, meningitis, periventricular leucomalacia, athetoid cerebral palsy, perinatal septicaemia and anaemia, herpes encephalitis, and epilepsy. Only 27% were idiopathic. CONCLUSION: Quick phase failure is a constant feature of OMA, whereas abnormal head movements were detected in only about half

  12. Intermittent horizontal saccade failure ('ocular motor apraxia') in children.

    PubMed

    Harris, C M; Shawkat, F; Russell-Eggitt, I; Wilson, J; Taylor, D

    1996-02-01

    Ocular motor apraxia (OMA) in childhood is a poorly understood condition involving a failure of horizontal saccades. OMA is thought to be rare but the literature indicates wide clinical associations. OMA is often identified by abnormal head movements, but failure of reflexive quick phases has been reported in all but a few patients. The extent of this oculomotor disorder was examined in a large group of children with diverse clinical backgrounds. The degree of quick phase failure during horizontal vestibular and optokinetic nystagmus was measured using DC electro-oculography and video in 74 affected children, aged 17 days to 14 years. All children showed an intermittent failure of nystagmic quick phases, except for total failure in one case. Other visuomotor abnormalities were common including saccadic hypometria (85%), low gain smooth pursuit (70%), neurological nystagmus (28%), strabismus (22%), and vertical abnormalities (11%). Non-ocular abnormalities were common including infantile hypotonia (61%), motor delay (77%), and speech delay (87%). There was a wide range of clinical associations including agenesis of the corpus callosum, Joubert syndrome, Dandy-Walker malformation, microcephaly, hydrocephalus, vermis hypoplasia, porencephalic cyst, megalocephaly, Krabbe leucodystrophy, Pelizaeus Merzbacher disease, infantile Gaucher disease, GM1 gangliosidosis, infantile Refsum's disease, propionic acidaemia, ataxia telangiectasia, Bardet-Biedl syndrome, vermis astrocytoma, vermis cyst, carotid fibromuscular hypoplasia, Cornelia de Lange syndrome, and microphthalmos. Perinatal and postnatal problems were found in 15% including perinatal hypoxia, meningitis, periventricular leucomalacia, athetoid cerebral palsy, perinatal septicaemia and anaemia, herpes encephalitis, and epilepsy. Only 27% were idiopathic. Quick phase failure is a constant feature of OMA, whereas abnormal head movements were detected in only about half, depending on the underlying diagnosis. This

  13. The influence of nerve conduits diameter in motor nerve recovery after segmental nerve repair.

    PubMed

    Giusti, Guilherme; Shin, Richard H; Lee, Joo-Yup; Mattar, Tiago G; Bishop, Allen T; Shin, Alexander Y

    2014-11-01

    Many conduits have demonstrated potential to substitute nerve autografts; however, the influence of conduit inner diameter (ID) has never been studied as a separate parameter. This experimental study compared motor recovery after segmental nerve repair with two different ID collagen conduits: 1.5 and 2.0 mm. In addition, the conduits were analyzed in vitro to determine the variations of ID before and after hydration. Thirty rats were divided into three groups: 2.0 mm ID, 1.5 mm ID, and a control group autograft. After 12 weeks, the 1.5 mm ID group demonstrated significant increase in force (P < 0.0001) and weight (P < 0.0001) of the tibialis anterior muscle and better histomorphometry results of the peroneal nerve (P < 0.05) compared to 2.0 mm ID group; nevertheless, autograft results outperformed both conduits (P < 0.0001). Conduits ID were somewhat smaller than advertised, measuring 1.59 ± 0.03 mm and 1.25 ± 0.0 mm. Only the larger conduit showed a 6% increase in ID after hydration, changing to 1.69 ± 0.02 mm. Although autografts perform best, an improvement in motor recovery can be achieved with collagen conduits when a better size match conduit is being used. Minimal changes in collagen conduits ID can be expected after implantation.

  14. Marshall M. Parks Memorial Lecture: Ocular Motor Misbehavior in Children: Where Neuro-Ophthalmology Meets Strabismus.

    PubMed

    Brodsky, Michael C

    2017-06-01

    Clinical diagnosis has been supplemented by neuroimaging advances, genetic discoveries, and molecular research to generate new neurobiological discoveries pertaining to early maldevelopment of ocular motor control systems. In this focused review, I examine recent paradigm shifts that have transformed our understanding of pediatric ocular motor disease at the prenuclear and infranuclear levels. The pathogenesis of complex ocular motor disorders, such as paradoxical pupillary constriction to darkness, benign tonic upgaze of infancy, congenital fibrosis syndrome, and the constellation of unique eye movements that accompany Joubert syndrome, are elucidated. Copyright © 2017 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  15. Systemic and ocular findings in 100 patients with optic nerve hypoplasia.

    PubMed

    Garcia, M Lourdes; Ty, Edna B; Taban, Mehryar; David Rothner, A; Rogers, Douglas; Traboulsi, Elias I

    2006-11-01

    To describe associated ocular, neurologic, and systemic findings in a population of children with optic nerve hypoplasia, a retrospective chart review of 100 patients with optic nerve hypoplasia for the presence of neurologic, radiologic, and endocrine abnormalities was performed. Neuroimaging and endocrine studies were obtained in 65 cases. Visual acuity and associated ocular, neurologic, endocrine, systemic, and structural brain abnormalities were recorded. Seventy-five percent had bilateral optic nerve hypoplasia. Conditions previously associated with optic nerve hypoplasia and present in our patients include premature birth in 21%, fetal alcohol syndrome in 9%, maternal diabetes in 6%, and endocrine abnormalities in 6%. Developmental delay was present in 32%, cerebral palsy in 13%, and seizures in 12%. Of those imaged, 60% had an abnormal study. Neuroimaging showed abnormalities in ventricles or white- or gray-matter development in 29 patients, septo-optic dysplasia in 10, hydrocephalus in 10, and corpus callosum abnormalities in 8. There was an associated clinical neurologic abnormality in 57% of patients with bilateral optic nerve hypoplasia and in 32% of patients with unilateral optic nerve hypoplasia. Patients with unilateral and bilateral optic nerve hypoplasia frequently have a wide range and common occurrence of concomitant neurologic, endocrine, and systemic abnormalities.

  16. Rapid motor learning in the translational vestibulo-ocular reflex

    NASA Technical Reports Server (NTRS)

    Zhou, Wu; Weldon, Patrick; Tang, Bingfeng; King, W. M.; Shelhamer, M. J. (Principal Investigator)

    2003-01-01

    Motor learning was induced in the translational vestibulo-ocular reflex (TVOR) when monkeys were repeatedly subjected to a brief (0.5 sec) head translation while they tried to maintain binocular fixation on a visual target for juice rewards. If the target was world-fixed, the initial eye speed of the TVOR gradually increased; if the target was head-fixed, the initial eye speed of the TVOR gradually decreased. The rate of learning acquisition was very rapid, with a time constant of approximately 100 trials, which was equivalent to <1 min of accumulated stimulation. These learned changes were consolidated over >or=1 d without any reinforcement, indicating induction of long-term synaptic plasticity. Although the learning generalized to targets with different viewing distances and to head translations with different accelerations, it was highly specific for the particular combination of head motion and evoked eye movement associated with the training. For example, it was specific to the modality of the stimulus (translation vs rotation) and the direction of the evoked eye movement in the training. Furthermore, when one eye was aligned with the heading direction so that it remained motionless during training, learning was not expressed in this eye, but only in the other nonaligned eye. These specificities show that the learning sites are neither in the sensory nor the motor limb of the reflex but in the sensory-motor transformation stage of the reflex. The dependence of the learning on both head motion and evoked eye movement suggests that Hebbian learning may be one of the underlying cellular mechanisms.

  17. Rapid motor learning in the translational vestibulo-ocular reflex

    NASA Technical Reports Server (NTRS)

    Zhou, Wu; Weldon, Patrick; Tang, Bingfeng; King, W. M.; Shelhamer, M. J. (Principal Investigator)

    2003-01-01

    Motor learning was induced in the translational vestibulo-ocular reflex (TVOR) when monkeys were repeatedly subjected to a brief (0.5 sec) head translation while they tried to maintain binocular fixation on a visual target for juice rewards. If the target was world-fixed, the initial eye speed of the TVOR gradually increased; if the target was head-fixed, the initial eye speed of the TVOR gradually decreased. The rate of learning acquisition was very rapid, with a time constant of approximately 100 trials, which was equivalent to <1 min of accumulated stimulation. These learned changes were consolidated over >or=1 d without any reinforcement, indicating induction of long-term synaptic plasticity. Although the learning generalized to targets with different viewing distances and to head translations with different accelerations, it was highly specific for the particular combination of head motion and evoked eye movement associated with the training. For example, it was specific to the modality of the stimulus (translation vs rotation) and the direction of the evoked eye movement in the training. Furthermore, when one eye was aligned with the heading direction so that it remained motionless during training, learning was not expressed in this eye, but only in the other nonaligned eye. These specificities show that the learning sites are neither in the sensory nor the motor limb of the reflex but in the sensory-motor transformation stage of the reflex. The dependence of the learning on both head motion and evoked eye movement suggests that Hebbian learning may be one of the underlying cellular mechanisms.

  18. Reinnervation of Urethral and Anal Sphincters With Femoral Motor Nerve to Pudendal Nerve Transfer

    PubMed Central

    Ruggieri, Michael R.; Braverman, Alan S.; Bernal, Raymond M.; Lamarre, Neil S.; Brown, Justin M.; Barbe, Mary F.

    2012-01-01

    Aims Lower motor neuron damage to sacral roots or nerves can result in incontinence and a flaccid urinary bladder. We showed bladder reinnervation after transfer of coccygeal to sacral ventral roots, and genitofemoral nerves (L1, 2 origin) to pelvic nerves. This study assesses the feasibility of urethral and anal sphincter reinnervation using transfer of motor branches of the femoral nerve (L2–4 origin) to pudendal nerves (S1, 2 origin) that innervate the urethral and anal sphincters in a canine model. Methods Sacral ventral roots were selected by their ability to stimulate bladder, urethral sphincter, and anal sphincter contraction and transected. Bilaterally, branches of the femoral nerve, specifically, nervus saphenous pars muscularis [Evans HE. Miller’s anatomy of the dog. Philadelphia: W.B. Saunders; 1993], were transferred and end-to-end anastomosed to transected pudendal nerve branches in the perineum, then enclosed in unipolar nerve cuff electrodes with leads to implanted RF micro-stimulators. Results Nerve stimulation induced increased anal and urethral sphincter pressures in five of six transferred nerves. Retrograde neurotracing from the bladder, urethral sphincter, and anal sphincter using fluorogold, fast blue, and fluororuby, demonstrated urethral and anal sphincter labeled neurons in L2–4 cord segments (but not S1–3) in nerve transfer canines, consistent with rein-nervation by the transferred femoral nerve motor branches. Controls had labeled neurons only in S1–3 segments. Postmortem DiI and DiO labeling confirmed axonal regrowth across the nerve repair site. Conclusions These results show spinal cord reinnervation of urethral and anal sphincter targets after sacral ventral root transection and femoral nerve transfer (NT) to the denervated pudendal nerve. These surgical procedures may allow patients to regain continence. PMID:21953679

  19. Motor evoked potentials enable differentiation between motor and sensory branches of peripheral nerves in animal experiments.

    PubMed

    Turkof, Edvin; Jurasch, Nikita; Knolle, Erik; Schwendenwein, Ilse; Habib, Danja; Unger, Ewald; Reichel, Martin; Losert, Udo

    2006-10-01

    Differentiation between motor and sensory fascicles is frequently necessary in reconstructive peripheral nerve surgery. The goal of this experimental study was to verify if centrally motor evoked potentials (MEP) could be implemented to differentiate sensory from motor fascicles, despite the well-known intermingling between nerve fascicles along their course to their distant periphery. This new procedure would enable surgeons to use MEP for placing nerve grafts at corresponding fascicles in the proximal and distal stumps without the need to use time-consuming staining. In ten sheep, both ulnar nerves were exposed at the terminal bifurcation between the last sensory and motor branch. Animals were then relaxed to avoid volume conduction. On central stimulation, the evoked nerve compound action potentials were simultaneously recorded from both terminal branches. In all cases, neurogenic motor nerve action potentials were recorded only from the terminal motor branch. The conclusion was that MEPs can be used for intraoperative differentiation between sensory and motor nerves. Further studies are necessary to develop this method for in situ measurements on intact nerve trunks.

  20. Congenital Ocular Motor Apraxia: An Inter-Disciplinary Approach to Educational Intervention.

    ERIC Educational Resources Information Center

    Sultmann, William; And Others

    1981-01-01

    A coordinated approach adopted by support personnel (educational psychologist, remedial teacher, occupational therapist, and speech therapist) for two boys (8 and 11 years old) with ocular motor perceptual problems led to initial evaluation of progress in reading and spelling. (Author)

  1. Motor cortex neuroplasticity associated with lingual nerve injury in rats.

    PubMed

    Adachi, Kazunori; Lee, Jye-Chang; Hu, James W; Yao, Dongyuan; Sessle, Barry J

    2007-09-01

    The aim of this study was to determine if lingual nerve trauma affects the features of face primary motor cortex (MI) defined by intracortical microstimulation (ICMS). The left lingual nerve was transected in adult male rats by an oral surgical procedure; sham rats (oral surgery but no nerve transection) as well as naive intact rats served as control groups. ICMS was applied at post-operative days 0, 7, 14, 21, and 28 to map the jaw and tongue motor representations in face MI by analyzing ICMS-evoked movements and electromyographic activity recorded in the genioglossus (GG) and anterior digastric (AD) muscles. There were no statistically significant effects of acute (day 0) nerve transection or sham procedure (p > 0.05). The surgery in the sham animals was associated with limited post-operative change; this was reflected in a significant (p < 0.05) increase in the number of GG sites in left MI at post-operative day 14 compared to day 0. However, nerve transection was associated with significant increases in the total number of AD and GG sites in left or right MI or specifically the number of GG sites in rats at post-operative days 21 or 28 compared to earlier time periods. There were also significant differences between nerve-transected and sham groups at post-operative days 7, 14, or 21. These findings suggest that lingual nerve transection is associated with significant time-dependent neuroplastic changes in the tongue motor representations in face MI.

  2. Combined effect of motor imagery and peripheral nerve electrical stimulation on the motor cortex.

    PubMed

    Saito, Kei; Yamaguchi, Tomofumi; Yoshida, Naoshin; Tanabe, Shigeo; Kondo, Kunitsugu; Sugawara, Kenichi

    2013-06-01

    Although motor imagery enhances the excitability of the corticospinal tract, there are no peripheral afferent inputs during motor imagery. In contrast, peripheral nerve electrical stimulation (ES) can induce peripheral afferent inputs; thus, a combination of motor imagery and ES may enhance the excitability of the corticospinal tract compared with motor imagery alone. Moreover, the level of stimulation intensity may also be related to the modulation of the excitability of the corticospinal tract during motor imagery. Here, we evaluated whether a combination of motor imagery and peripheral nerve ES influences the excitability of the corticospinal tract and measured the effect of ES intensity on the excitability induced during motor imagery. The imagined task was a movement that involved touching the thumb to the little finger, whereas ES involved simultaneous stimulation of the ulnar and median nerves at the wrist. Two different ES intensities were used, one above the motor threshold and another above the sensory threshold. Further, we evaluated whether actual movement with afferent input induced by ES modulates the excitability of the corticospinal tract as well as motor imagery. We found that a combination of motor imagery and ES enhanced the excitability of the motor cortex in the thenar muscle compared with the other condition. Furthermore, we established that the modulation of the corticospinal tract was related to ES intensity. However, we found that the excitability of the corticospinal tract induced by actual movement was enhanced by peripheral nerve ES above the sensory threshold.

  3. Human tongue neuroanatomy: Nerve supply and motor endplates.

    PubMed

    Mu, Liancai; Sanders, Ira

    2010-10-01

    The human tongue has a critical role in speech, swallowing, and respiration, however, its motor control is poorly understood. Fundamental gaps include detailed information on the course of the hypoglossal (XII) nerve within the tongue, the branches of the XII nerve within each tongue muscle, and the type and arrangement of motor endplates (MEP) within each muscle. In this study, five adult human tongues were processed with Sihler's stain, a whole-mount nerve staining technique, to map out the entire intra-lingual course of the XII nerve and its branches. An additional five specimens were microdissected into individual muscles and stained with acetylcholinesterase and silver staining to study their MEP morphology and banding patterns. Using these techniques the course of the entire XII nerve was mapped from the main nerve to the smallest intramuscular branches. It was found that the human tongue innervation is extremely dense and complex. Although the basic mammalian pattern of XII is conserved in humans, there are notable differences. In addition, many muscle fibers contained multiple en grappe MEP, suggesting that they are some variant of the highly specialized slow tonic muscle fiber type. The transverse muscle group that comprises the core of the tongue appears to have the most complex innervation and has the highest percentage of en grappe MEP. In summary, the innervation of the human tongue has specializations not reported in other mammalian tongues, including nonhuman primates. These specializations appear to allow for fine motor control of tongue shape. © 2010 Wiley-Liss, Inc.

  4. Human Tongue Neuroanatomy: Nerve Supply and Motor Endplates

    PubMed Central

    Mu, Liancai; Sanders, Ira

    2010-01-01

    The human tongue has a critical role in speech, swallowing, and respiration, however, its motor control is poorly understood. Fundamental gaps include detailed information on the course of the hypoglossal (XII) nerve within the tongue, the branches of the XII nerve within each tongue muscle, and the type and arrangement of motor endplates (MEP) within each muscle. In this study, five adult human tongues were processed with Sihler’s stain, a whole-mount nerve staining technique, to map out the entire intra-lingual course of the XII nerve and its branches. An additional five specimens were microdissected into individual muscles and stained with acetylcholinesterase and silver staining to study their MEP morphology and banding patterns. Using these techniques the course of the entire XII nerve was mapped from the main nerve to the smallest intramuscular branches. It was found that the human tongue innervation is extremely dense and complex. Although the basic mammalian pattern of XII is conserved in humans, there are notable differences. In addition, many muscle fibers contained multiple en grappe MEP, suggesting that they are some variant of the highly specialized slow tonic muscle fiber type. The transverse muscle group that comprises the core of the tongue appears to have the most complex innervation and has the highest percentage of en grappe MEP. In summary, the innervation of the human tongue has specializations not reported in other mammalian tongues, including non-human primates. These specializations appear to allow for fine motor control of tongue shape. PMID:20607833

  5. Adult motor axons preferentially reinnervate predegenerated muscle nerve.

    PubMed

    Abdullah, M; O'Daly, A; Vyas, A; Rohde, C; Brushart, T M

    2013-11-01

    Preferential motor reinnervation (PMR) is the tendency for motor axons regenerating after repair of mixed nerve to reinnervate muscle nerve and/or muscle rather than cutaneous nerve or skin. PMR may occur in response to the peripheral nerve pathway alone in juvenile rats (Brushart, 1993; Redett et al., 2005), yet the ability to identify and respond to specific pathway markers is reportedly lost in adults (Uschold et al., 2007). The experiments reported here evaluate the relative roles of pathway and end organ in the genesis of PMR in adult rats. Fresh and 2-week predegenerated femoral nerve grafts were transferred in correct or reversed alignment to replace the femoral nerves of previously unoperated Lewis rats. After 8 weeks of regeneration the motoneurons projecting through the grafts to recipient femoral cutaneous and muscle branches and their adjacent end organs were identified by retrograde labeling. Motoneuron counts were subjected to Poisson regression analysis to determine the relative roles of pathway and end organ identity in generating PMR. Transfer of fresh grafts did not result in PMR, whereas substantial PMR was observed when predegenerated grafts were used. Similarly, the pathway through which motoneurons reached the muscle had a significant impact on PMR when grafts were predegenerated, but not when they were fresh. Comparison of the relative roles of pathway and end organ in generating PMR revealed that neither could be shown to be more important than the other. These experiments demonstrate unequivocally that adult muscle nerve and cutaneous nerve differ in qualities that can be detected by regenerating adult motoneurons and that can modify their subsequent behavior. They also reveal that two weeks of Wallerian degeneration modify the environment in the graft from one that provides no modality-specific cues for motor neurons to one that actively promotes PMR.

  6. Axonal Regeneration and Motor Neuron Survival after Microsurgical Nerve Reconstruction

    PubMed Central

    Fox, Ida K.; Brenner, Michael J.; Johnson, Philip J.; Hunter, Daniel A.; Mackinnon, Susan E.

    2014-01-01

    Rodent models are used extensively for studying nerve regeneration, but little is known about how sprouting and pruning influence peripheral nerve fiber counts and motor neuron pools. The purpose of this study was to identify fluctuations in nerve regeneration and neuronal survival over time. One hundred and forty-four Lewis rats were randomized to end-to-end repair or nerve grafting (1.5 cm graft) after sciatic nerve transection. Quantitative histomorphometry and retrograde labeling of motor neurons were performed at 1, 3, 6, 9, 12, and 24 months and supplemented by electron microscopy. Fiber counts and motor neuron counts increased between 1 and 3 months, followed by plateau. End-to-end repair resulted in persistently higher fiber counts compared to the grafting for all time points (P < 0.05). Percent neural tissue and myelin width increased with time while fibrin debris dissipated. In conclusion, these data detail the natural history of regeneration and demonstrate that overall fiber counts may remain stable despite pruning. PMID:22806696

  7. Diagnostic Biopsy of a Motor Branch of the Superficial Peroneal Nerve to the Peroneus Longus: A Convenient Alternative for Motor Nerve Biopsy.

    PubMed

    D'Amico, Randy S; Winfree, Christopher J

    2017-07-01

    Motor nerve biopsy is performed to supplement clinical, serologic, and imaging data in the workup of neuropathies of unknown origin, especially when motor neuron disease is suspected. We describe a surgical technique for biopsy of a motor branch of the superficial peroneal nerve innervating the peroneus longus muscle. Three patients presented with weakness concerning for motor neuropathy and underwent biopsy of a motor branch of the superficial peroneal nerve innervating the peroneus longus muscle. The surgical technique is described in detail. Biopsied tissue was sufficient for pathologic diagnosis. No patient suffered postsurgical sensory or motor deficits related to the procedure. No patient suffered postsurgical complications. Biopsy of the motor branch of the superficial peroneal nerve to the peroneus longus is a safe and effective alternative for motor nerve biopsy and can be easily combined with peroneus longus muscle biopsy. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Misdirection of regenerating motor axons after nerve injury and repair in the rat sciatic nerve model

    PubMed Central

    de Ruiter, Godard C. W.; Malessy, Martijn J. A.; Alaid, Awad O.; Spinner, Robert J.; Engelstad, JaNean K.; Sorenson, E. J.; Kaufman, K. R.; Dyck, Peter J.; Windebank, Anthony J.

    2010-01-01

    Misdirection of regenerating axons is one of the factors that can explain the poor results often found after nerve injury and repair. In this study, we quantified the degree of misdirection and the effect on recovery of function after different types of nerve injury and repair in the rat sciatic nerve model; crush injury, direct coaptation, and autograft repair. Sequential tracing with retrograde labeling of the peroneal nerve before and 8 weeks after nerve injury and repair was performed to quantify the accuracy of motor axon regeneration. Digital video analysis of ankle motion was used to investigate the recovery of function. In addition, serial compound action potential recordings and nerve and muscle morphometry were performed. In our study, accuracy of motor axon regeneration was found to be limited; only 71% (±4.9%) of the peroneal motoneurons were correctly directed 2 months after sciatic crush injury, 42% (±4.2%) after direct coaptation, and 25% (±6.6%) after autograft repair. Recovery of ankle motion was incomplete after all types of nerve injury and repair and demonstrated a disturbed balance of ankle plantar and dorsiflexion. The number of motoneurons from which axons had regenerated was not significantly different from normal. The number of myelinated axons was significantly increased distal to the site of injury. Misdirection of regenerating motor axons is a major factor in the poor recovery of nerves that innervate different muscles. The results of this study can be used as basis for developing new nerve repair techniques that may improve the accuracy of regeneration. PMID:18448099

  9. Surgical and conservative methods for restoring impaired motor function - facial nerve, spinal accessory nerve, hypoglossal nerve (not including vagal nerve or swallowing)

    PubMed Central

    Laskawi, R.; Rohrbach, S.

    2005-01-01

    The present review gives a survey of rehabilitative measures for disorders of the motor function of the mimetic muscles (facial nerve), and muscles innervated by the spinal accessory and hypoglossal nerves. The dysfunction can present either as paralysis or hyperkinesis (hyperkinesia). Conservative and surgical treatment options aimed at restoring normal motor function and correcting the movement disorders are described. Static reanimation techniques are not dealt with. The final section describes the use of botulinum toxin in the therapy of dysphagia. PMID:22073058

  10. [Nerve transfer between the intercostal nerves and the motor component of the musculocutaneous nerve. Anatomical study of feasibility].

    PubMed

    Fleury, M; Lepage, D; Pluvy, I; Pauchot, J

    2017-06-01

    The intercostal nerves (ICN) transfer to the musculocutaneous nerve (MCN) can restore elbow flexion in complete brachial plexus palsy. The last cases our service dealt with, allowed our staff to observe two different situations. In the 2 first patients, we were able to proceed with an intraneurodissection of the MCN motor component up to the axillary cavity level, while on the third case such dissection could not be performed as high. The aim of this work is to assess the feasibility of a transfer on the MCN's motor component. We conducted a series of 5 cadaver dissections of the MCN and ICN on the anatomy laboratory. Using magnifying loupes to perform an intraneurodissection, we were able to split the motor and sensory fibers as they stood out. It would help motor recuperation avoiding directional error on sensitive component. The ICN can be sutured on the motor component of the MCN, provided the dissection is very minutious. The intraneurodissection of the MCN up to the axillary cavity level is possible as the interfascicular exchanges are scarce there. Publications already refer to the possibility of a nerve transfer between the ICN and the motor component of the MCN. Therefore, our researches suggest that such a procedure can be considered for routine procedures. The neurotization is one of the latest breakthroughs in terms of brachial plexus surgery. We are hopeful that anatomical researches could lead to optimization possibilities. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  11. External ocular motor palsies in ophthalmic zoster: a review.

    PubMed Central

    Marsh, R J; Dulley, B; Kelly, V

    1977-01-01

    Seventy-seven new patients suffering from ophthalmic zoster and a selected group of 69 old patients were carefully examined with regard to external ocular movements. An incidence of 31% of ocular pareses was found in the new patients, and 58 in all were analysed. We were surprised to find several of these were contralateral and bilateral palsies. 28% of the palsies were asymptomatic, due to diplopia being present only in extremes of gaze and the rapid development of suppression in the affected eye. The theories of aetiology of these pareses are discussed. PMID:338027

  12. Histological observation of RGCs and optic nerve injury in acute ocular hypertension rats

    PubMed Central

    Li, Shuang; Fang, Jia-Hua; Jiang, Fa-Gang

    2010-01-01

    AIM To explore the injury of retinal ganglion cells (RGCs) and optic nerves in acute ocular hypertension (OHT) rats. METHODS We retrogradely labeled RGCs and optic nerves of Sprague-Dawley rats by injecting 20g/L fluorogold (FG) into bilateral superior colliculi. Twenty-four hours after the injection, the right eyes were performed physiological saline anterior chamber perfusion with intraocular pressure maintained at 100mmHg for 60 minutes, while the contralateral eyes were performed sham procedure as control group without elevation of the saline bottle. Retinal hematoxylin and eosin (HE) sections, retinal whole mounts and frozen sections were made 14 days later to observe the morphology and survival of RGCs. Frozen sections and transmission electron microscopy were utilized to investigate the histological manifestations of optic nerves at the same time. RESULTS A larger number of RGCs presented in control group. It had an average density of 1995±125/mm2 and distributed uniformly, while RGCs in OHT eyes reduced significantly to 1505±43/mm2 compared with control group (P<0.05). The optic nerves in control group showed stronger and more uniform fluorescence on the frozen sections, and the auxiliary fibers as well as myelin sheaths were in even and intact organization by transmission electron microscopy. However, exiguous fluorescence signals, vesicular dissociation and disintegration of myelin sheaths were found in OHT group. CONCLUSION The present study suggested that fluorogold retrograde tracing is a feasible, convenient method for quantitative and qualitative study of neuronal populations and axonal injury in acute ocular hypertension rats. PMID:22553581

  13. Peripheral nerve entrapment caused by motor vehicle crashes.

    PubMed

    Coert, J H; Dellon, A L

    1994-08-01

    During the era before seatbelts and air bags, extensive injury was common after motor vehicle collisions (MVCs). Yet upper extremity peripheral nerve problems, other than the brachial plexus injury, have not been ascribed previously to MVCs. Seven hundred twenty-five patients with the diagnosis of carpal tunnel syndrome (CTS), cubital tunnel syndrome (CT), and radial sensory nerve (RSN) entrapment in the forearm were reviewed. The number of MVC-caused nerve entrapments was 157 (68 for CTS, 64 for CT, and 25 for RSN). In 25% of the patients, the nerve entrapment was bilateral. This paper discusses the causal relationship between MVCs and subsequent nerve compressions in the upper extremity and discusses a suggested pathomechanism of injury. The most common pattern was for the injured person to be the driver, to have the injured hand or hands on the steering wheel, to be hit from the front or rear, and to develop a sudden onset of nerve compression symptoms within 1 week. Awareness of this causal relationship may allow early recognition and treatment.

  14. Motor Neuron Activation in Peripheral Nerves Using Infrared Neural Stimulation

    PubMed Central

    Peterson, EJ; Tyler, DJ

    2014-01-01

    Objective Localized activation of peripheral axons may improve selectivity of peripheral nerve interfaces. Infrared neural stimulation (INS) employs localized delivery to activate neural tissue. This study investigated INS to determine whether localized delivery limited functionality in larger mammalian nerves. Approach The rabbit sciatic nerve was stimulated extraneurally with 1875 nm-wavelength infrared light, electrical stimulation, or a combination of both. Infrared-sensitive regions (ISR) of the nerve surface and electromyogram (EMG) recruitment of the Medial Gastrocnemius, Lateral Gastrocnemius, Soleus, and Tibialis Anterior were the primary output measures. Stimulation applied included infrared-only, electrical-only, and combined infrared and electrical. Main results 81% of nerves tested were sensitive to INS, with 1.7± 0.5 ISR detected per nerve. INS was selective to a single muscle within 81% of identified ISR. Activation energy threshold did not change significantly with stimulus power, but motor activation decreased significantly when radiant power was decreased. Maximum INS levels typically recruited up to 2–9% of any muscle. Combined infrared and electrical stimulation differed significantly from electrical recruitment in 7% of cases. Significance The observed selectivity of INS indicates it may be useful in augmenting rehabilitation, but significant challenges remain in increasing sensitivity and response magnitude to improve the functionality of INS. PMID:24310923

  15. Motor neuron activation in peripheral nerves using infrared neural stimulation

    NASA Astrophysics Data System (ADS)

    Peterson, E. J.; Tyler, D. J.

    2014-02-01

    Objective. Localized activation of peripheral axons may improve selectivity of peripheral nerve interfaces. Infrared neural stimulation (INS) employs localized delivery to activate neural tissue. This study investigated INS to determine whether localized delivery limited functionality in larger mammalian nerves. Approach. The rabbit sciatic nerve was stimulated extraneurally with 1875 nm wavelength infrared light, electrical stimulation, or a combination of both. Infrared-sensitive regions (ISR) of the nerve surface and electromyogram (EMG) recruitment of the Medial Gastrocnemius, Lateral Gastrocnemius, Soleus, and Tibialis Anterior were the primary output measures. Stimulation applied included infrared-only, electrical-only, and combined infrared and electrical. Main results. 81% of nerves tested were sensitive to INS, with 1.7 ± 0.5 ISR detected per nerve. INS was selective to a single muscle within 81% of identified ISR. Activation energy threshold did not change significantly with stimulus power, but motor activation decreased significantly when radiant power was decreased. Maximum INS levels typically recruited up to 2-9% of any muscle. Combined infrared and electrical stimulation differed significantly from electrical recruitment in 7% of cases. Significance. The observed selectivity of INS indicates that it may be useful in augmenting rehabilitation, but significant challenges remain in increasing sensitivity and response magnitude to improve the functionality of INS.

  16. [Motor replacement surgery via tendon transfer in radial nerve palsy].

    PubMed

    Koulaxouzidis, G; Stark, G B; Lampert, F M

    2015-02-01

    Restoration of active extension of wrist, thumb and digits by muscle-tendon transposition. Radial nerve palsy due to peripheral nerve injury. Peripheral nerve disease. Muscle or tendon injury. Restoration of wrist extension in high radial nerve palsy. Reversible distal radial nerve palsy, absence of suitable donor muscles, spasticity, limited range of motion of affected joints, extensive scarring and inappropriate soft tissue conditions, unjustifiable loss of function at donor site. Reinnervated donor muscles, progressive muscle disease, insufficient patient compliance. Dissection of the flexor carpi ulnaris, palmaris longus and pronator teres tendon insertion. Transposition of the tendons. Interweaving of tendons of the pronator teres and extensor carpi radialis brevis muscles, the extensor digitorum communis and flexor carpi ulnaris muscles, as well as the extensor pollicis longus and palmaris longus muscles using the Pulvertaft technique. 3 Weeks immobilization in forearm splint. Additional immobilization for 2 weeks at night. Subsequently, intensive physical and occupational therapy for another 4-6 weeks is required, starting 3 weeks postoperatively. The procedure was carried out in 12 patients over the past 14 years. We treated proximal radial nerve palsy in nine cases. In accordance with the current medical literature, we consider the described motor replacement surgery a reliable procedure.

  17. Motor imagery muscle contraction strength influences spinal motor neuron excitability and cardiac sympathetic nerve activity.

    PubMed

    Bunno, Yoshibumi; Suzuki, Toshiaki; Iwatsuki, Hiroyasu

    2015-12-01

    [Purpose] The aim of this study was to investigate the changes in spinal motor neuron excitability and autonomic nervous system activity during motor imagery of isometric thenar muscle activity at 10% and 50% maximal voluntary contraction (MVC). [Methods] The F-waves and low frequency/high frequency (LF/HF) ratio were recorded at rest, during motor imagery, and post-trial. For motor imagery trials, subjects were instructed to imagine thenar muscle activity at 10% and 50% MVC while holding the sensor of a pinch meter for 5 min. [Results] The F-waves and LF/HF ratio during motor imagery at 50% MVC were significantly increased compared with those at rest, whereas those during motor imagery at 10% MVC were not significantly different from those at rest. The relative values of the F/M amplitude ratio during motor imagery at 50% MVC were significantly higher than those at 10% MVC. The relative values of persistence and the LF/HF ratio during motor imagery were similar during motor imagery at the two muscle contraction strengths. [Conclusion] Motor imagery can increase the spinal motor neuron excitability and cardiac sympathetic nerve activity. Motor imagery at 50% MVC may be more effective than motor imagery at 10% MVC.

  18. Reversal of Motor Learning in the Vestibulo-Ocular Reflex in the Absence of Visual Input

    ERIC Educational Resources Information Center

    Cohen, Marlene R.; Meissner, Geoffrey W.; Schafer, Robert J.; Raymond, Jennifer L.

    2004-01-01

    Motor learning in the vestibulo-ocular reflex (VOR) and eyeblink conditioning use similar neural circuitry, and they may use similar cellular plasticity mechanisms. Classically conditioned eyeblink responses undergo extinction after prolonged exposure to the conditioned stimulus in the absence of the unconditioned stimulus. We investigated the…

  19. Reversal of Motor Learning in the Vestibulo-Ocular Reflex in the Absence of Visual Input

    ERIC Educational Resources Information Center

    Cohen, Marlene R.; Meissner, Geoffrey W.; Schafer, Robert J.; Raymond, Jennifer L.

    2004-01-01

    Motor learning in the vestibulo-ocular reflex (VOR) and eyeblink conditioning use similar neural circuitry, and they may use similar cellular plasticity mechanisms. Classically conditioned eyeblink responses undergo extinction after prolonged exposure to the conditioned stimulus in the absence of the unconditioned stimulus. We investigated the…

  20. Ocular Motor Indicators of Executive Dysfunction in Fragile X and Turner Syndromes

    ERIC Educational Resources Information Center

    Lasker, Adrian G.; Mazzocco, Michele M. M.; Zee, David S.

    2007-01-01

    Fragile X and Turner syndromes are two X-chromosome-related disorders associated with executive function and visual spatial deficits. In the present study, we used ocular motor paradigms to examine evidence that disruption to different neurological pathways underlies these deficits. We tested 17 females with fragile X, 19 females with Turner…

  1. Ocular Motor Indicators of Executive Dysfunction in Fragile X and Turner Syndromes

    ERIC Educational Resources Information Center

    Lasker, Adrian G.; Mazzocco, Michele M. M.; Zee, David S.

    2007-01-01

    Fragile X and Turner syndromes are two X-chromosome-related disorders associated with executive function and visual spatial deficits. In the present study, we used ocular motor paradigms to examine evidence that disruption to different neurological pathways underlies these deficits. We tested 17 females with fragile X, 19 females with Turner…

  2. Manifestations of ALS in the cranial motor nerves: dynametric, neuropathologic, and speech motor data.

    PubMed

    DePaul, R; Abbs, J H

    1987-05-01

    Although our knowledge of ALS manifestations in the cranial motor nerves is limited, available retrospective and prospective reports, including associated neuropathology in the cranial motor nerves, clearly indicate fruitful directions for additional biologically based studies. These data further demonstrate that the brain stem, with multiple discrete motoneuron groups, is amenable to parallel behavioral, anatomic, histochemical, and pharmacologic analyses as a means to enhance clinical diagnosis and management of ALS. Moreover, the contribution of such studies to the further understanding of the underlying mechanisms of ALS may be of even greater potential.

  3. The Impact of Ocular Pressures, Material Properties and Geometry on Optic Nerve Head Deformation

    NASA Technical Reports Server (NTRS)

    Feola, Andrew J.; Myers, Jerry G.; Raykin, Julia; Nelson, Emily S.; Samuels, Brian C.; Ethier C. Ross

    2017-01-01

    Alteration in intracranial pressure (ICP) has been associated with various diseases that cause visual impairment, including glaucoma, idiopathic intracranial hypertension and Visual Impairment and Intracranial Pressure (VIIP) syndrome. However, how changes in ICP lead to vision loss is unclear, although it is hypothesized to involve deformations of the tissues in the optic nerve head (ONH). Recently, understanding the effect of ICP alterations on ocular tissues has become a major concern for NASA, where 42 of astronauts that partake in long duration space missions suffer from VIIP syndrome. Astronauts with VIIP syndrome suffer from visual impairment and changes in ocular anatomy that persist after returning to earth (1). It is hypothesized that the cephalad fluid shift that occurs upon entering microgravity increases ICP, which leads to an altered biomechanical environment in the posterior globe and optic nerve sheath, and subsequently VIIP syndrome. Our goal was to develop a finite element (FE) model to simulate the acute effects of elevated ICP on the posterior eye. Here, we simulated how inter-individual differences affect the deformation of ONH tissues. Further, we examined how several different geometries influenced deformations when exposed to elevated ICP.

  4. Congenital nystagmus: hypotheses for its genesis and complex waveforms within a behavioral ocular motor system model.

    PubMed

    Jacobs, Jonathan B; Dell'Osso, Louis F

    2004-07-27

    Attempts to simulate dysfunction within ocular motor system (OMS) models capable of exhibiting known ocular motor behavior have provided valuable insight into the structure of the OMS required for normal visual function. The pendular waveforms of congenital nystagmus (CN) appear to be quite complex, composed of a sustained sinusoidal oscillation punctuated by braking saccades and foveating saccades followed by periods of extended foveation. Previously, we verified that these quick phases are generated by the same mechanism as voluntary saccades. We propose a computer model of the ocular motor system that simulates the responses of individuals with pendular CN (including its variable waveforms) based on the instability exhibited by the normal pursuit subsystem and its interaction with other components of the normal ocular motor control system. Fixation data from subjects with CN using both infrared and magnetic search coil oculography were used as templates for our simulations. Our OMS model simulates data from individuals with CN during fixation and in response to complex stimuli. The use of position and velocity efference copy to suppress oscillopsia is the key element in allowing for normal ocular motor behavior. The model's responses to target steps, pulse-steps, ramps, and step-ramps support the hypothetical explanation for the conditions that result in sustained pendular oscillation and the rules for the corrective saccadic responses that shape this underlying oscillation into the well-known family of pendular CN waveforms: pendular (P), pseudopendular (PP), pendular with foveating saccades (Pfs), and pseudopendular with foveating saccades (PPfs). Position error determined the saccadic amplitudes of foveating saccades, whereas stereotypical braking saccades were not dependent on visual information. Additionally, we propose a structure and method of operation for the fixation subsystem, and use it to prolong the low-velocity intervals immediately following

  5. Cranial nerve modulation of human cortical swallowing motor pathways.

    PubMed

    Hamdy, S; Aziz, Q; Rothwell, J C; Hobson, A; Barlow, J; Thompson, D G

    1997-04-01

    Animal data indicate that cortical swallowing pathways can be modulated by cranial nerve afferent stimulation. We therefore studied the effects of human trigeminal and vagal nerve excitation on the corticofugal pathways to the oropharynx and esophagus, using electromagnetic stimulation. Unilateral stimulation of either the trigeminal or vagus nerve evoked two distinct reflex electromyographic responses in the pharynx and esophagus, an early response (latency range 19-30 ms) and a late response (latency range 42-72 ms). In the mylohyoid muscles, however, only a single response was seen (latency range 36-64 ms). Cortical stimulation also evoked electromyographic responses in the mylohyoid muscles, pharynx, and esophagus, with latencies of 8.5 +/- 0.3, 9.3 +/- 0.3, and 10.1 +/- 0.4 ms, respectively. When either trigeminal or vagus nerve stimulation preceded cortical stimulation, the cortically evoked responses were facilitated, with maximal effects at interstimulation intervals of 30-200 ms for pharynx and esophagus (P < 0.02) and at interstimulation intervals of 50-100 ms for mylohyoid muscles (P < 0.05). Our results demonstrate that stimulation of human cranial nerve afferent fibers facilitates cortical swallowing motor pathways.

  6. Influence of motor activities on the release of transmitter quanta from motor nerve terminals in mice.

    PubMed

    Taquahashi, Y; Yonezawa, K; Nishimura, M

    1999-05-01

    We investigated the effects of motor activities on transmitter release in mouse nerve-muscle preparations of the diaphragm muscle (DPH), extensor digitorum longus muscle (EDL), and soleus muscle (SOL). Mice were divided into a control group, a motor-restricted (RST) group, and a motor-compelled (CMP) group. The quantal content (m) of endplate potentials was measured intracellularly. In DPH the motor activity was unaffected. In the CMP group the m value of the EDL group increased with increases in the cooperativity of Ca2+ in transmitter release. Compared with the CMP group, the SOL of the RST group had a smaller m value with increases in the cooperativity of Ca2+ in transmitter release. These results suggest that motor activities can influence neuromuscular activity specific to different systems, however, the motor compulsion specifically activated the function of EDL and the motor restriction activated the function of SOL, and these effects might lead to altered activity of the release of transmitter quanta in motor nerve terminals of mice.

  7. Impediments to eye transplantation: ocular viability following optic-nerve transection or enucleation.

    PubMed

    Ellenberg, D; Shi, J; Jain, S; Chang, J-H; Ripps, H; Brady, S; Melhem, E R; Lakkis, F; Adamis, A; Chen, D-F; Ellis-Behnke, R; Langer, R S; Strittmatter, S M; Azar, D T

    2009-09-01

    Maintenance of ocular viability is one of the major impediments to successful whole-eye transplantation. This review provides a comprehensive understanding of the current literature to help guide future studies in order to overcome this hurdle. A systematic multistage review of published literature was performed. Three specific questions were addressed: (1) Is recovery of visual function following eye transplantation greater in cold-blooded vertebrates when compared with mammals? (2) Is outer retina function following enucleation and reperfusion improved compared with enucleation alone? (3) Following optic-nerve transection, is there a correlation between retinal ganglion cell (RGC) survival and either time after transection or proximity of the transection to the globe? In a majority of the studies performed in the literature, recovery of visual function can occur after whole-eye transplantation in cold-blooded vertebrates. Following enucleation (and reperfusion), outer retinal function is maintained from 4 to 9 h. RGC survival following optic-nerve transection is inversely related to both the time since transection and the proximity of transection to the globe. Lastly, neurotrophins can increase RGC survival following optic-nerve transection. This review of the literature suggests that the use of a donor eye is feasible for whole-eye transplantation.

  8. Impediments to eye transplantation: ocular viability following optic-nerve transection or enucleation

    PubMed Central

    Ellenberg, D; Shi, J; Jain, S; Chang, J-H; Ripps, H; Brady, S; Melhem, E R; Lakkis, F; Adamis, A; Chen, D-F; Ellis-Behnke, R; Langer, R S; Strittmatter, S M; Azar, D T

    2010-01-01

    Maintenance of ocular viability is one of the major impediments to successful whole-eye transplantation. This review provides a comprehensive understanding of the current literature to help guide future studies in order to overcome this hurdle. A systematic multistage review of published literature was performed. Three specific questions were addressed: (1) Is recovery of visual function following eye transplantation greater in cold-blooded vertebrates when compared with mammals? (2) Is outer retina function following enucleation and reperfusion improved compared with enucleation alone? (3) Following optic-nerve transection, is there a correlation between retinal ganglion cell (RGC) survival and either time after transection or proximity of the transection to the globe? In a majority of the studies performed in the literature, recovery of visual function can occur after whole-eye transplantation in cold-blooded vertebrates. Following enucleation (and reperfusion), outer retinal function is maintained from 4 to 9 h. RGC survival following optic-nerve transection is inversely related to both the time since transection and the proximity of transection to the globe. Lastly, neurotrophins can increase RGC survival following optic-nerve transection. This review of the literature suggests that the use of a donor eye is feasible for whole-eye transplantation. PMID:19286686

  9. Motor Nerve Conduction Velocity In Postmenopausal Women with Peripheral Neuropathy.

    PubMed

    Singh, Akanksha; Asif, Naiyer; Singh, Paras Nath; Hossain, Mohd Mobarak

    2016-12-01

    The post-menopausal phase is characterized by a decline in the serum oestrogen and progesterone levels. This phase is also associated with higher incidence of peripheral neuropathy. To explore the relationship between the peripheral motor nerve status and serum oestrogen and progesterone levels through assessment of Motor Nerve Conduction Velocity (MNCV) in post-menopausal women with peripheral neuropathy. This cross-sectional study was conducted at Jawaharlal Nehru Medical College during 2011-2013. The study included 30 post-menopausal women with peripheral neuropathy (age: 51.4±7.9) and 30 post-menopausal women without peripheral neuropathy (control) (age: 52.5±4.9). They were compared for MNCV in median, ulnar and common peroneal nerves and serum levels of oestrogen and progesterone estimated through enzyme immunoassays. To study the relationship between hormone levels and MNCV, a stepwise linear regression analysis was done. The post-menopausal women with peripheral neuropathy had significantly lower MNCV and serum oestrogen and progesterone levels as compared to control subjects. Stepwise linear regression analysis showed oestrogen with main effect on MNCV. The findings of the present study suggest that while the post-menopausal age group is at a greater risk of peripheral neuropathy, it is the decline in the serum estrogen levels which is critical in the development of peripheral neuropathy.

  10. Motor Nerve Conduction Velocity In Postmenopausal Women with Peripheral Neuropathy

    PubMed Central

    Asif, Naiyer; Singh, Paras Nath; Hossain, Mohd Mobarak

    2016-01-01

    Introduction The post-menopausal phase is characterized by a decline in the serum oestrogen and progesterone levels. This phase is also associated with higher incidence of peripheral neuropathy. Aim To explore the relationship between the peripheral motor nerve status and serum oestrogen and progesterone levels through assessment of Motor Nerve Conduction Velocity (MNCV) in post-menopausal women with peripheral neuropathy. Materials and Methods This cross-sectional study was conducted at Jawaharlal Nehru Medical College during 2011-2013. The study included 30 post-menopausal women with peripheral neuropathy (age: 51.4±7.9) and 30 post-menopausal women without peripheral neuropathy (control) (age: 52.5±4.9). They were compared for MNCV in median, ulnar and common peroneal nerves and serum levels of oestrogen and progesterone estimated through enzyme immunoassays. To study the relationship between hormone levels and MNCV, a stepwise linear regression analysis was done. Results The post-menopausal women with peripheral neuropathy had significantly lower MNCV and serum oestrogen and progesterone levels as compared to control subjects. Stepwise linear regression analysis showed oestrogen with main effect on MNCV. Conclusion The findings of the present study suggest that while the post-menopausal age group is at a greater risk of peripheral neuropathy, it is the decline in the serum estrogen levels which is critical in the development of peripheral neuropathy. PMID:28208850

  11. Mutant human myocilin induces strain specific differences in ocular hypertension and optic nerve damage in mice.

    PubMed

    McDowell, Colleen M; Luan, Tomi; Zhang, Zhang; Putliwala, Tasneem; Wordinger, Robert J; Millar, J Cameron; John, Simon W M; Pang, Iok-Hou; Clark, Abbot F

    2012-07-01

    0.19 (n = 18, p < 0.001) in the injected eye. There was no statistical difference in retinal ganglion cell death or superior colliculus damage at the 8-week time point in any of the strains tested. These results demonstrate strain dependent responses to Ad5.MYOC.Y437H-induced ocular hypertension and pressure-induced optic nerve damage. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Degeneration and regeneration of motor and sensory nerves: a stereological study of crush lesions in rat facial and mental nerves.

    PubMed

    Barghash, Z; Larsen, J O; Al-Bishri, A; Kahnberg, K-E

    2013-12-01

    The aim of this study was to evaluate the degeneration and regeneration of a sensory nerve and a motor nerve at the histological level after a crush injury. Twenty-five female Wistar rats had their mental nerve and the buccal branch of their facial nerve compressed unilaterally against a glass rod for 30s. Specimens of the compressed nerves and the corresponding control nerves were dissected at 3, 7, and 19 days after surgery. Nerve cross-sections were stained with osmium tetroxide and toluidine blue and analysed using two-dimensional stereology. We found differences between the two nerves both in the normal anatomy and in the regenerative pattern. The mental nerve had a larger cross-sectional area including all tissue components. The mental nerve had a larger volume fraction of myelinated axons and a correspondingly smaller volume fraction of endoneurium. No differences were observed in the degenerative pattern; however, at day 19 the buccal branch had regenerated to the normal number of axons, whereas the mental nerve had only regained 50% of the normal number of axons. We conclude that the regenerative process is faster and/or more complete in the facial nerve (motor function) than it is in the mental nerve (somatosensory function).

  13. Role of the flocculus of the cerebellum in motor learning of the vestibulo-ocular reflex

    NASA Technical Reports Server (NTRS)

    Highstein, S. M.

    1998-01-01

    Structure-function studies at the systems level are an effective method for understanding the relationship of the central nervous system to behavior. Motor learning or adaptation of the vestibulo-ocular reflex is a clear example wherein this approach has been productive. During a vestibulo-ocular reflex the brain converts a head velocity signal, transduced through the vestibular semicircular canals, into an eye movement command delivered to the extraocular muscles. If the viewed target remains on the fovea of the retina, the reflex is compensatory, and its gain, eye velocity/head velocity, is one. When the image of the viewed object slips across the retina, visual acuity decreases, and the gain of the reflex, which is no longer one, is plastically adapted or adjusted until retinal stability is restored. The anatomic substrate for this plasticity thus involves brain structures in which visual-vestibular interaction can potentially occur, as well as vestibular and visual sensory and oculomotor motor structures. Further, it has been known for many years that removal of the flocculus of the cerebellum permanently precludes further vestibulo-ocular reflex adaptation, demonstrating the involvement of the cerebellum in this behavior. Maekawa and Simpson (J Neurophysiol 1973;36: 649-66) discovered that one visual input to the flocculus involved the accessory optic system and the inferior olive. Ensuing work has demonstrated that the visual signals used to adapt the vestibulo-ocular reflex are transmitted by this accessory optic system to the flocculus and subsequently to brain stem structures involved in vestibulo-ocular reflex plasticity. Presently the inclusive list of anatomic sites involved in vestibulo-ocular reflex circuitry and its adaptive plasticity is small. Our laboratory continues to believe that this behavior should be caused by interactions within this small class of neurons. By studying each class of identified neuron and its interactions with others within

  14. Role of the flocculus of the cerebellum in motor learning of the vestibulo-ocular reflex

    NASA Technical Reports Server (NTRS)

    Highstein, S. M.

    1998-01-01

    Structure-function studies at the systems level are an effective method for understanding the relationship of the central nervous system to behavior. Motor learning or adaptation of the vestibulo-ocular reflex is a clear example wherein this approach has been productive. During a vestibulo-ocular reflex the brain converts a head velocity signal, transduced through the vestibular semicircular canals, into an eye movement command delivered to the extraocular muscles. If the viewed target remains on the fovea of the retina, the reflex is compensatory, and its gain, eye velocity/head velocity, is one. When the image of the viewed object slips across the retina, visual acuity decreases, and the gain of the reflex, which is no longer one, is plastically adapted or adjusted until retinal stability is restored. The anatomic substrate for this plasticity thus involves brain structures in which visual-vestibular interaction can potentially occur, as well as vestibular and visual sensory and oculomotor motor structures. Further, it has been known for many years that removal of the flocculus of the cerebellum permanently precludes further vestibulo-ocular reflex adaptation, demonstrating the involvement of the cerebellum in this behavior. Maekawa and Simpson (J Neurophysiol 1973;36: 649-66) discovered that one visual input to the flocculus involved the accessory optic system and the inferior olive. Ensuing work has demonstrated that the visual signals used to adapt the vestibulo-ocular reflex are transmitted by this accessory optic system to the flocculus and subsequently to brain stem structures involved in vestibulo-ocular reflex plasticity. Presently the inclusive list of anatomic sites involved in vestibulo-ocular reflex circuitry and its adaptive plasticity is small. Our laboratory continues to believe that this behavior should be caused by interactions within this small class of neurons. By studying each class of identified neuron and its interactions with others within

  15. Ocular, Neurologic and Systemic Findings of the Cases with Optic Nerve Hypoplasia

    PubMed Central

    Karahan, Eyyup; Tulin Berk, Ayse

    2016-01-01

    Aim: To describe the associated ocular, neurologic, and systemic findings in a population of children with optic nerve hypoplasia (ONH) and to evaluate the relationship between ocular signs and neurologic findings. Method: A retrospective chart review of 53 patients with the diagnosis of ONH seen between December 1998 and September 2012 was performed. All neurodevelopmental anomalies, neuroradiologic findings, endocrinologic and systemic findings were recorded. Poor vision was defined as the visual acuity poorer than logMAR 1.0 or inadequate central steady maintained fixation. Results: Thirty (56.6%) of the 53 children with ONH were boys. Mean age at presentation was 56.2±46.8 months (range; 3 months to 18 years). Poor vision defined for the purpose of this study was found in 47.2% of 53 patients. Thirty-three (62.3%) children had nystagmus. Thirty-four (64.2%) children had strabismus. Thirteen (38.2%) of those with strabismus had esotropia, 20 (58.8%) had exotropia. The total number of the children with neurodevelopmental deficit was 22 (41.5%) in our study. Conclusion: The vision of young children with ONH should be monitored at least annually, and any refractive errors should be treated. Neuroimaging of the brain and endocrinologic evaluation is necessary in all cases with ONH. PMID:27014380

  16. Sensory but not parasympathetic nerves are required for ocular vascular remodeling following chronic sympathectomy in rat.

    PubMed

    Steinle, J J; Smith, P G

    2003-11-28

    Choroidal vascularity increases following chronic sympathetic denervation in rats. The mechanisms of this remodeling are unclear. Since both nitric oxide and substance P/CGRP have been suggested as angiogenic factors in other targets, we hypothesized that sensory or parasympathetic nerves may also participate in ocular vascular remodeling. To test this hypothesis, sympathetic denervation was accomplished by superior cervical ganglionectomy. Sensory denervation was induced by subcutaneous injections of capsaicin on postnatal days 2 and 9, and ocular parasympathetic innervation was ablated by pterygopalatine ganglion excision on postnatal day 60. Eyes were processed and sectioned for light microscopic histomorphometry. Sympathetic denervation for 6 weeks resulted in increased choroidal thickness, vascular luminal area, numbers of large venules and large arterioles, and capillaries in the outer nuclear layer. Capsaicin pretreatment prevented sympathectomy-induced increases in choroidal thickness, vascular luminal area and large venules and large arterioles, whereas pterygopalatine ganglionectomy was without effect. Both sensory and parasympathetic denervation attenuated increases in outer nuclear layer capillaries. These studies indicate that increased choroidal vascularity noted after chronic sympathectomy requires intact sensory innervation.

  17. Ocular Neuromyotonia Associated with Chronic Inflammatory Demyelinating Polyneuropathy.

    PubMed

    Kung, Nathan H; Bucelli, Robert C; McClelland, Collin M; Van Stavern, Gregory P

    2015-10-01

    Ocular neuromyotonia (ONM) is a neuro-ophthalmic disorder characterized by episodic diplopia caused by contraction of one or more ocular muscles due to spontaneous excitation of the respective ocular motor nerve. We report a patient whose ocular neuromyotonia arose in the setting of a subacute demyelinating polyneuropathy consistent with chronic inflammatory demyelinating polyneuropathy (CIDP) and subsequently resolved following the initiation of intravenous immunoglobulin (IVIg) for her neuropathy. Our patient provides additional evidence towards the role of demyelination and ephaptic neurotransmission in ocular neuromyotonia and also represents the first reported case of ocular neuromyotonia associated with a systemic neurological condition.

  18. [Motor nerves of the face. Surgical and radiologic anatomy of facial paralysis and their surgical repair].

    PubMed

    Vacher, C; Cyna-Gorse, F

    2015-10-01

    Motor innervation of the face depends on the facial nerve for the mobility of the face, on the mandibular nerve, third branch of the trigeminal nerve, which gives the motor innervation of the masticator muscles, and the hypoglossal nerve for the tongue. In case of facial paralysis, the most common palliative surgical techniques are the lengthening temporalis myoplasty (the temporal is innervated by the mandibular nerve) and the hypoglossal-facial anastomosis. The aim of this work is to describe the surgical anatomy of these three nerves and the radiologic anatomy of the facial nerve inside the temporal bone. Then the facial nerve penetrates inside the parotid gland giving a plexus. Four branches of the facial nerve leave the parotid gland: they are called temporal, zygomatic, buccal and marginal which give innervation to the cutaneous muscles of the face. Mandibular nerve gives three branches to the temporal muscles: the anterior, intermediate and posterior deep temporal nerves which penetrate inside the deep aspect of the temporal muscle in front of the infratemporal line. The hypoglossal nerve is only the motor nerve to the tongue. The ansa cervicalis, which is coming from the superficial cervical plexus and joins the hypoglossal nerve in the submandibular area is giving the motor innervation to subhyoid muscles and to the geniohyoid muscle. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  19. Repression of inactive motor nerve terminals in partially denervated rat muscle after regeneration of active motor axons.

    PubMed Central

    Ribchester, R R; Taxt, T

    1984-01-01

    The fourth deep lumbrical muscle in the hind foot of adult rats was partially denervated by crushing the sural nerve (s.n.). The denervated muscle fibres became completely reinnervated by sprouts from lateral plantar nerve (l.p.n.) motor axons. By about 20 days after the nerve crush, s.n. motor axons started to reinnervate the muscle. In control muscles, a small proportion of the muscle fibres--about 2.5% of the muscle per motor unit--was reinnervated by s.n. motor axons over the following 20 days. Hence the regenerating terminals were able to re-establish functional synapses, despite the fact that all the muscle fibres were functionally innervated by l.p.n. terminals. When nerve impulse conduction in the l.p.n. was blocked with tetrodotoxin for up to 2 weeks, starting from the time when s.n. axons returned to the muscle, s.n. motor axons retrieved a much larger proportion of the muscle fibres--about 6.5% of the muscle per motor unit. There was a concomitant decrease in the tension produced by the sprouted l.p.n. motor axons. Intracellular recordings showed that many muscle fibres became innervated exclusively by regenerated s.n. motor nerve terminals. Measurements of end-plate potentials suggested that l.p.n. sprouts and the original nerve terminals were eliminated non-selectively. These results suggest that regenerating, active motor nerve terminals have an additional competitive advantage in reinnervating innervated muscles, if the intact terminals are inactive. When the l.p.n. was cut, rather than blocked, extensive reinnervation by the s.n. occurred-about 30% of the muscle per motor unit. This suggests that the absence of an intact nerve terminal in the motor end-plate provides a stronger stimulus than inactivity for synapse formation by regenerating motor axons. PMID:6707966

  20. CNS-derived glia ensheath peripheral nerves and mediate motor root development.

    PubMed

    Kucenas, Sarah; Takada, Norio; Park, Hae-Chul; Woodruff, Elvin; Broadie, Kendal; Appel, Bruce

    2008-02-01

    Motor function requires that motor axons extend from the spinal cord at regular intervals and that they are myelinated by Schwann cells. Little attention has been given to another cellular structure, the perineurium, which ensheaths the motor nerve, forming a flexible, protective barrier. Consequently, the origin of perineurial cells and their roles in motor nerve formation are poorly understood. Using time-lapse imaging in zebrafish, we show that perineurial cells are born in the CNS, arising as ventral spinal-cord glia before migrating into the periphery. In embryos lacking perineurial glia, motor neurons inappropriately migrated outside of the spinal cord and had aberrant axonal projections, indicating that perineurial glia carry out barrier and guidance functions at motor axon exit points. Additionally, reciprocal signaling between perineurial glia and Schwann cells was necessary for motor nerve ensheathment by both cell types. These insights reveal a new class of CNS-born glia that critically contributes to motor nerve development.

  1. The anatomy and physiology of the ocular motor system.

    PubMed

    Horn, Anja K E; Leigh, R John

    2011-01-01

    Accurate diagnosis of abnormal eye movements depends upon knowledge of the purpose, properties, and neural substrate of distinct functional classes of eye movement. Here, we summarize current concepts of the anatomy of eye movement control. Our approach is bottom-up, starting with the extraocular muscles and their innervation by the cranial nerves. Second, we summarize the neural circuits in the pons underlying horizontal gaze control, and the midbrain connections that coordinate vertical and torsional movements. Third, the role of the cerebellum in governing and optimizing eye movements is presented. Fourth, each area of cerebral cortex contributing to eye movements is discussed. Last, descending projections from cerebral cortex, including basal ganglionic circuits that govern different components of gaze, and the superior colliculus, are summarized. At each stage of this review, the anatomical scheme is used to predict the effects of lesions on the control of eye movements, providing clinical-anatomical correlation. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Disrupted Saccade Control in Chronic Cerebral Injury: Upper Motor Neuron-Like Disinhibition in the Ocular Motor System.

    PubMed

    Rizzo, John-Ross; Hudson, Todd E; Abdou, Andrew; Lui, Yvonne W; Rucker, Janet C; Raghavan, Preeti; Landy, Michael S

    2017-01-01

    Saccades rapidly direct the line of sight to targets of interest to make use of the high acuity foveal region of the retina. These fast eye movements are instrumental for scanning visual scenes, foveating targets, and, ultimately, serve to guide manual motor control, including eye-hand coordination. Cerebral injury has long been known to impair ocular motor control. Recently, it has been suggested that alterations in control may be useful as a marker for recovery. We measured eye movement control in a saccade task in subjects with chronic middle cerebral artery stroke with both cortical and substantial basal ganglia involvement and in healthy controls. Saccade latency distributions were bimodal, with an early peak at 60 ms (anticipatory saccades) and a later peak at 250 ms (regular saccades). Although the latencies corresponding to these peaks were the same in the two groups, there were clear differences in the size of the peaks. Classifying saccade latencies relative to the saccade "go signal" into anticipatory (latencies up to 80 ms), "early" (latencies between 80 and 160 ms), and "regular" types (latencies longer than 160 ms), stroke subjects displayed a disproportionate number of anticipatory saccades, whereas control subjects produced the majority of their saccades in the regular range. We suggest that this increase in the number of anticipatory saccade events may result from a disinhibition phenomenon that manifests as an impairment in the endogenous control of ocular motor events (saccades) and interleaved fixations. These preliminary findings may help shed light on the ocular motor deficits of neurodegenerative conditions, results that may be subclinical to an examiner, but clinically significant secondary to their functional implications.

  3. Disrupted Saccade Control in Chronic Cerebral Injury: Upper Motor Neuron-Like Disinhibition in the Ocular Motor System

    PubMed Central

    Rizzo, John-Ross; Hudson, Todd E.; Abdou, Andrew; Lui, Yvonne W.; Rucker, Janet C.; Raghavan, Preeti; Landy, Michael S.

    2017-01-01

    Saccades rapidly direct the line of sight to targets of interest to make use of the high acuity foveal region of the retina. These fast eye movements are instrumental for scanning visual scenes, foveating targets, and, ultimately, serve to guide manual motor control, including eye–hand coordination. Cerebral injury has long been known to impair ocular motor control. Recently, it has been suggested that alterations in control may be useful as a marker for recovery. We measured eye movement control in a saccade task in subjects with chronic middle cerebral artery stroke with both cortical and substantial basal ganglia involvement and in healthy controls. Saccade latency distributions were bimodal, with an early peak at 60 ms (anticipatory saccades) and a later peak at 250 ms (regular saccades). Although the latencies corresponding to these peaks were the same in the two groups, there were clear differences in the size of the peaks. Classifying saccade latencies relative to the saccade “go signal” into anticipatory (latencies up to 80 ms), “early” (latencies between 80 and 160 ms), and “regular” types (latencies longer than 160 ms), stroke subjects displayed a disproportionate number of anticipatory saccades, whereas control subjects produced the majority of their saccades in the regular range. We suggest that this increase in the number of anticipatory saccade events may result from a disinhibition phenomenon that manifests as an impairment in the endogenous control of ocular motor events (saccades) and interleaved fixations. These preliminary findings may help shed light on the ocular motor deficits of neurodegenerative conditions, results that may be subclinical to an examiner, but clinically significant secondary to their functional implications. PMID:28184211

  4. [Electrophysiological monitoring of cranial motor nerves (V, VII, IX, X, XI, XII)].

    PubMed

    Lefaucheur, J-P; Neves, D O; Vial, C

    2009-04-01

    In various neurosurgical operations, there is a risk of cranial nerve lesion that can be avoided or minimized with intraoperative electrophysiological monitoring. Regarding motor function of the cranial nerves, stimulodetection techniques are used, including electrical stimulation of nerve trunks and electromyographic recording of evoked motor responses. These techniques can be used for monitoring the trigeminal nerve (Vth cranial nerve), facial nerve (VIIth), glossopharyngeal nerve (IXth), pneumogastric nerve (Xth), spinal accessory nerve (XIth), and hypoglossal nerve (XIIth), in particular during surgical removal of tumors of the cerebellopontine angle or skull base. When beginning an operation, electrical stimulation is only used to identify the nerve structures. As removal of the tumor progresses, the goal is to verify that a surgical injury to the nerve is avoided by looking for the absence of any change regarding amplitude, morphology, and latency of motor responses. Intraoperative electromyographic monitoring can also be applied during the surgical treatment of primary hemifacial spasm by microvascular decompression. An effective decompression is usually associated with the disappearance of "lateral spread" motor responses to facial nerve branch stimulation. Therefore, the intraoperative disappearance of the lateral spread responses can be considered a predictive factor of good postoperative clinical outcome, even if this assertion remains a matter of debate.

  5. Collateral development and spinal motor reorganization after nerve injury and repair.

    PubMed

    Yu, Youlai; Zhang, Peixun; Han, Na; Kou, Yuhui; Yin, Xiaofeng; Jiang, Baoguo

    2016-01-01

    Functional recovery is often unsatisfactory after severe extended nerve defects or proximal nerve trunks injuries repaired by traditional repair methods, as the long regeneration distance for the regenerated axons to reinnervate their original target end-organs. The proximal nerve stump can regenerate with many collaterals that reinnervate the distal stump after peripheral nerve injury, it may be possible to use nearby fewer nerve fibers to repair more nerve fibers at the distal end to shorten the regenerating distance. In this study, the proximal peroneal nerve was used to repair both the distal peroneal and tibial nerve. The number and location of motor neurons in spinal cord as well as functional and morphological recovery were assessed at 2 months, 4 months and 8 months after nerve repair, respectively. Projections from the intact peroneal and tibial nerves were also studied in normal animals. The changes of motor neurons were assessed using the retrograde neurotracers FG and DiI to backlabel motor neurons that regenerate axons into two different pathways. To evaluate the functional recovery, the muscle forces and sciatic function index were examined. The muscles and myelinated axons were assessed using electrophysiology and histology. The results showed that all labeled motor neurons after nerve repair were always confined within the normal peroneal nerve pool and nearly all the distribution of motor neurons labeled via distal different nerves was disorganized as compared to normal group. However, there was a significant decline in the number of double labeled motor neurons and an obvious improvement with respect to the functional and morphological recovery between 2 and 8 months. In addition, the tibial/peroneal motor neuron number ratio at different times was 2.11±0.05, 2.13±0.08, 2.09±0.12, respectively, and was close to normal group (2.21±0.09). Quantitative analysis showed no significant morphological differences between myelinated nerve fibers

  6. Collateral development and spinal motor reorganization after nerve injury and repair

    PubMed Central

    Yu, Youlai; Zhang, Peixun; Han, Na; Kou, Yuhui; Yin, Xiaofeng; Jiang, Baoguo

    2016-01-01

    Functional recovery is often unsatisfactory after severe extended nerve defects or proximal nerve trunks injuries repaired by traditional repair methods, as the long regeneration distance for the regenerated axons to reinnervate their original target end-organs. The proximal nerve stump can regenerate with many collaterals that reinnervate the distal stump after peripheral nerve injury, it may be possible to use nearby fewer nerve fibers to repair more nerve fibers at the distal end to shorten the regenerating distance. In this study, the proximal peroneal nerve was used to repair both the distal peroneal and tibial nerve. The number and location of motor neurons in spinal cord as well as functional and morphological recovery were assessed at 2 months, 4 months and 8 months after nerve repair, respectively. Projections from the intact peroneal and tibial nerves were also studied in normal animals. The changes of motor neurons were assessed using the retrograde neurotracers FG and DiI to backlabel motor neurons that regenerate axons into two different pathways. To evaluate the functional recovery, the muscle forces and sciatic function index were examined. The muscles and myelinated axons were assessed using electrophysiology and histology. The results showed that all labeled motor neurons after nerve repair were always confined within the normal peroneal nerve pool and nearly all the distribution of motor neurons labeled via distal different nerves was disorganized as compared to normal group. However, there was a significant decline in the number of double labeled motor neurons and an obvious improvement with respect to the functional and morphological recovery between 2 and 8 months. In addition, the tibial/peroneal motor neuron number ratio at different times was 2.11±0.05, 2.13±0.08, 2.09±0.12, respectively, and was close to normal group (2.21±0.09). Quantitative analysis showed no significant morphological differences between myelinated nerve fibers

  7. Maxillofacial and ocular injuries in motor vehicle crashes.

    PubMed Central

    Brookes, Christopher Noel

    2004-01-01

    BACKGROUND: Injuries from motor vehicle crashes constitute a leading cause of death in the young and a high degree of morbidity and mortality in all age groups. Facial trauma has been consistently shown to be the single most common injury to the occupants of vehicles involved in crashes. This has been confirmed by more recent studies which have demonstrated a continuing high incidence of facial fractures amongst belted drivers. Airbags have been advocated as a supplemental restraint system. However, their deployment can cause injury particularly if the driver is of short stature, unrestrained or out of position within the vehicle. METHODS: The Crash Injury Research Engineering Network (CIREN) project aims to correlate the injuries received by occupants in vehicle crashes with the biomechanics of vehicle deformation. All cases of facial injury which presented to the University of Michigan Medical Center, USA in 1999 were retrospectively evaluated with reference to the methods of occupant restraint and to the correlation between the injuries sustained and vehicle deformation. RESULTS AND CONCLUSIONS: The case analysis confirmed the value of airbags to the safety of vehicle occupants but reinforced the conclusion that they must still be considered supplemental restraint systems. New generation airbags will minimise the risk of injury even to small stature or out of position occupants as they will prevent deployment in situations where they may have an adverse effect. PMID:15140296

  8. The Spectrum of Vestibular and Ocular Motor Abnormalities in Thiamine Deficiency.

    PubMed

    Kattah, Jorge C

    2017-05-01

    The first aim of this review is to summarize recent ocular motor signs in pre-encephalopathy patients with nutritional deficiency at risk of thiamine deficiency. Timely recognition of thiamine depletion in these patients, who may have a normal brain MRI, could lead to appropriate management and prevention of Wernicke's encephalopathy (WE) with full recovery. The second aim is to incorporate recent diagnostic testing on the revised WE diagnostic criteria and the identification of patients who may show slow, partial, or no response to treatment. Selective vulnerability of periventricular gray neurons in thiamine deficiency is well known. Involvement of the vestibular and abducens nuclei may precede encephalopathy. Studies have shown mild ophthalmoparesis and bilateral symmetric vestibular loss in thiamine deficiency. Moreover, quantitative data has shown decreased horizontal vestibulo-ocular reflex (VOR) gain and nystagmus, with a favorable response to timely treatment. Ophthalmoparesis, horizontal nystagmus, and decreased gain of the horizontal VOR, sparing the vertical VOR, may be present in the early pre-encephalopathy stage of thiamine deficiency. Rapid response to a loading dose of parenteral thiamine might be seen in some cases and normalization, albeit slower in others. In contrast, analogous to the Korsakoff's syndrome, ocular motor and vestibular abnormalities may show only partial improvement. Future studies in larger populations at risk are needed to confirm the results of these preliminary observations.

  9. A Brief Vestibular/Ocular Motor Screening (VOMS) Assessment to Evaluate Concussions

    PubMed Central

    Mucha, Anne; Collins, Michael W.; Elbin, R.J.; Furman, Joseph M.; Troutman-Enseki, Cara; DeWolf, Ryan M.; Marchetti, Greg; Kontos, Anthony P.

    2014-01-01

    Background Vestibular and ocular motor impairments and symptoms have been documented in patients with sport-related concussions. However, there is no current brief clinical screen to assess and monitor these issues. Purpose To describe and provide initial data for the internal consistency and validity of a brief clinical screening tool for vestibular and ocular motor impairments and symptoms after sport-related concussions. Study Design Cross-sectional study; Level of evidence, 2. Methods Sixty-four patients, aged 13.9 ± 2.5 years and seen approximately 5.5 ± 4.0 days after a sport-related concussion, and 78 controls were administered the Vestibular/Ocular Motor Screening (VOMS) assessment, which included 5 domains: (1) smooth pursuit, (2) horizontal and vertical saccades, (3) near point of convergence (NPC) distance, (4) horizontal vestibular ocular reflex (VOR), and (5) visual motion sensitivity (VMS). Participants were also administered the Post-Concussion Symptom Scale (PCSS). Results Sixty-one percent of patients reported symptom provocation after at least 1 VOMS item. All VOMS items were positively correlated to the PCSS total symptom score. The VOR (odds ratio [OR], 3.89; P <.001) and VMS (OR, 3.37; P <.01) components of the VOMS were most predictive of being in the concussed group. An NPC distance ≥5 cm and any VOMS item symptom score ≥2 resulted in an increase in the probability of correctly identifying concussed patients of 38% and 50%, respectively. Receiver operating characteristic curves supported a model including the VOR, VMS, NPC distance, and ln(age) that resulted in a high predicted probability (area under the curve = 0.89) for identifying concussed patients. Conclusion The VOMS demonstrated internal consistency as well as sensitivity in identifying patients with concussions. The current findings provide preliminary support for the utility of the VOMS as a brief vestibular/ocular motor screen after sport-related concussions. The VOMS may

  10. A Brief Vestibular/Ocular Motor Screening (VOMS) assessment to evaluate concussions: preliminary findings.

    PubMed

    Mucha, Anne; Collins, Michael W; Elbin, R J; Furman, Joseph M; Troutman-Enseki, Cara; DeWolf, Ryan M; Marchetti, Greg; Kontos, Anthony P

    2014-10-01

    Vestibular and ocular motor impairments and symptoms have been documented in patients with sport-related concussions. However, there is no current brief clinical screen to assess and monitor these issues. To describe and provide initial data for the internal consistency and validity of a brief clinical screening tool for vestibular and ocular motor impairments and symptoms after sport-related concussions. Cross-sectional study; Level of evidence, 2. Sixty-four patients, aged 13.9 ± 2.5 years and seen approximately 5.5 ± 4.0 days after a sport-related concussion, and 78 controls were administered the Vestibular/Ocular Motor Screening (VOMS) assessment, which included 5 domains: (1) smooth pursuit, (2) horizontal and vertical saccades, (3) near point of convergence (NPC) distance, (4) horizontal vestibular ocular reflex (VOR), and (5) visual motion sensitivity (VMS). Participants were also administered the Post-Concussion Symptom Scale (PCSS). Sixty-one percent of patients reported symptom provocation after at least 1 VOMS item. All VOMS items were positively correlated to the PCSS total symptom score. The VOR (odds ratio [OR], 3.89; P < .001) and VMS (OR, 3.37; P < .01) components of the VOMS were most predictive of being in the concussed group. An NPC distance ≥5 cm and any VOMS item symptom score ≥2 resulted in an increase in the probability of correctly identifying concussed patients of 38% and 50%, respectively. Receiver operating characteristic curves supported a model including the VOR, VMS, NPC distance, and ln(age) that resulted in a high predicted probability (area under the curve = 0.89) for identifying concussed patients. The VOMS demonstrated internal consistency as well as sensitivity in identifying patients with concussions. The current findings provide preliminary support for the utility of the VOMS as a brief vestibular/ocular motor screen after sport-related concussions. The VOMS may augment current assessment tools and may serve as a single

  11. Comparison of the fastest regenerating motor and sensory myelinated axons in the same peripheral nerve.

    PubMed

    Moldovan, Mihai; Sørensen, Jesper; Krarup, Christian

    2006-09-01

    Functional outcome after peripheral nerve regeneration is often poor, particularly involving nerve injuries far from their targets. Comparison of sensory and motor axon regeneration before target reinnervation is not possible in the clinical setting, and previous experimental studies addressing the question of differences in growth rates of different nerve fibre populations led to conflicting results. We developed an animal model to compare growth and maturation of the fastest growing sensory and motor fibres within the same mixed nerve after Wallerian degeneration. Regeneration of cat tibial nerve after crush (n = 13) and section (n = 7) was monitored for up to 140 days, using implanted cuff electrodes placed around the sciatic and tibial nerves and wire electrodes at plantar muscles. To distinguish between sensory and motor fibres, recordings were carried out from L6-S2 spinal roots using cuff electrodes. The timing of laminectomy was based on the presence of regenerating fibres along the nerve within the tibial cuff. Stimulation of unlesioned tibial nerves (n = 6) evoked the largest motor response in S1 ventral root and the largest sensory response in L7 dorsal root. Growth rates were compared by mapping the regenerating nerve fibres within the tibial nerve cuff to all ventral or dorsal roots and, regardless of the lesion type, the fastest growth was similar in sensory and motor fibres. Maturation was assessed as recovery of the maximum motor and sensory conduction velocities (CVs) within the tibial nerve cuff. Throughout the observation period the CV was approximately 14% faster in regenerated sensory fibres than in motor fibres in accordance with the difference observed in control nerves. Recovery of amplitude was only partial after section, whereas the root distribution pattern was restored. Our data suggest that the fastest growth and maturation rates that can be achieved during regeneration are similar for motor and sensory myelinated fibres.

  12. Myelinated sensory and alpha motor axon regeneration in peripheral nerve neuromas

    NASA Technical Reports Server (NTRS)

    Macias, M. Y.; Lehman, C. T.; Sanger, J. R.; Riley, D. A.

    1998-01-01

    Histochemical staining for carbonic anhydrase and cholinesterase (CE) activities was used to analyze sensory and motor axon regeneration, respectively, during neuroma formation in transected and tube-encapsulated peripheral nerves. Median-ulnar and sciatic nerves in the rodent model permitted testing whether a 4 cm greater distance of the motor neuron soma from axotomy site or intrinsic differences between motor and sensory neurons influenced regeneration and neuroma formation 10, 30, and 90 days later. Ventral root radiculotomy confirmed that CE-stained axons were 97% alpha motor axons. Distance significantly delayed axon regeneration. When distance was negligible, sensory axons grew out sooner than motor axons, but motor axons regenerated to a greater quantity. These results indicate regeneration differences between axon subtypes and suggest more extensive branching of motor axons within the neuroma. Thus, both distance from injury site to soma and inherent motor and sensory differences should be considered in peripheral nerve repair strategies.

  13. Myelinated sensory and alpha motor axon regeneration in peripheral nerve neuromas

    NASA Technical Reports Server (NTRS)

    Macias, M. Y.; Lehman, C. T.; Sanger, J. R.; Riley, D. A.

    1998-01-01

    Histochemical staining for carbonic anhydrase and cholinesterase (CE) activities was used to analyze sensory and motor axon regeneration, respectively, during neuroma formation in transected and tube-encapsulated peripheral nerves. Median-ulnar and sciatic nerves in the rodent model permitted testing whether a 4 cm greater distance of the motor neuron soma from axotomy site or intrinsic differences between motor and sensory neurons influenced regeneration and neuroma formation 10, 30, and 90 days later. Ventral root radiculotomy confirmed that CE-stained axons were 97% alpha motor axons. Distance significantly delayed axon regeneration. When distance was negligible, sensory axons grew out sooner than motor axons, but motor axons regenerated to a greater quantity. These results indicate regeneration differences between axon subtypes and suggest more extensive branching of motor axons within the neuroma. Thus, both distance from injury site to soma and inherent motor and sensory differences should be considered in peripheral nerve repair strategies.

  14. Ocular hypertension impairs optic nerve axonal transport leading to progressive retinal ganglion cell degeneration.

    PubMed

    Salinas-Navarro, Manuel; Alarcón-Martínez, Luis; Valiente-Soriano, Francisco J; Jiménez-López, Manuel; Mayor-Torroglosa, Sergio; Avilés-Trigueros, Marcelino; Villegas-Pérez, María Paz; Vidal-Sanz, Manuel

    2010-01-01

    Ocular hypertension (OHT) is the main risk factor of glaucoma, a neuropathy leading to blindness. Here we have investigated the effects of laser photocoagulation (LP)-induced OHT, on the survival and retrograde axonal transport (RAT) of adult rat retinal ganglion cells (RGC) from 1 to 12 wks. Active RAT was examined with fluorogold (FG) applied to both superior colliculi (SCi) 1 wk before processing and passive axonal diffusion with dextran tetramethylrhodamine (DTMR) applied to the optic nerve (ON) 2 d prior to sacrifice. Surviving RGCs were identified with FG applied 1 wk pre-LP or by Brn3a immunodetection. The ON and retinal nerve fiber layer were examined by RT97-neurofibrillar staining. RGCs were counted automatically and color-coded density maps were generated. OHT retinas showed absence of FG+ or DTMR+RGCs in focal, pie-shaped and diffuse regions of the retina which, by two weeks, amounted to, approximately, an 80% of RGC loss without further increase. At this time, there was a discrepancy between the total number of surviving FG-prelabelled RGCs and of DMTR+RGCs, suggesting that a large proportion of RGCs had their RAT impaired. This was further confirmed identifying surviving RGCs by their Brn3a expression. From 3 weeks onwards, there was a close correspondence of DTMR+RGCs and FG+RGCs in the same retinal regions, suggesting axonal constriction at the ON head. Neurofibrillar staining revealed, in ONs, focal degeneration of axonal bundles and, in the retinal areas lacking backlabeled RGCs, aberrant staining of RT97 characteristic of axotomy. LP-induced OHT results in a crush-like injury to ON axons leading to the anterograde and protracted retrograde degeneration of the intraocular axons and RGCs.

  15. Ocular motor measures of cognitive dysfunction in multiple sclerosis II: working memory.

    PubMed

    Clough, Meaghan; Mitchell, Laura; Millist, Lynette; Lizak, Nathaniel; Beh, Shin; Frohman, Teresa C; Frohman, Elliot M; White, Owen B; Fielding, Joanne

    2015-05-01

    Our companion paper documents pervasive inhibitory deficits in multiple sclerosis (MS) using ocular motor (OM) measures. Here we investigated the utility of an OM working memory (WMem) task in characterising WMem deficits in these patients as a function of disease status and disease duration. 22 patients with CIS, 22 early clinically definite MS patients (CDMS: <7 years of diagnosis), 22 late CDMS patients (>7 years from diagnosis), and 22 healthy controls participated. All participants completed the ocular motor WMem task, the paced auditory serial addition test (PASAT), and the symbol digit modalities test (SDMT). Clinical disability was characterised in CDMS patients using the Expanded Disability Severity Scale (EDSS). WMem performance was measured as proportion of errors (WMem errors), saccade latency, and relative sensitivity to WMem loading (WMem effect), an indicator of WMem capacity. All patient groups performed more WMem errors than controls with proportion of WMem errors, and degree of WMem effect increasing with increasing disease duration. A larger WMem effect, reflecting poorer WMem capacity, corresponded to poorer performance on neuropsychological measures, and a higher disability score for CDMS patients with the longest disease duration; an observation that suggests wider implication of WMem executive processes with advancing disease. Conspicuously, performance decrements on standard neuropsychological testing did not similarly increase commensurate with disease duration. The ocular motor WMem task appears to meaningfully dissociate WMem deficit from healthy individuals as well as a function of increasing disease duration. Potentially, this task represents a highly informative and objective method by which to ascertain progressive WMem changes from the earliest inception of MS.

  16. Normal maximal and minimal motor nerve conduction velocities in adults determined by a collision method.

    PubMed

    Arasaki, K; Iijima, M; Nakanishi, T

    1991-07-01

    Using a new collision method, we measured motor nerve conduction velocities of the ulnar nerve in the forearm and the action potential amplitude of the abductor digiti minimi muscle on 60 adults, ages 20 to 82 years and apparently free from diseases of the peripheral nervous system. Both maximal and minimal motor nerve conduction velocities were linear functions of age; 64.42-0.05 age and 60.45-0.12 age, respectively. The percentage of the minimal to the maximal motor nerve conduction velocities was expressed as 94.45-0.13 age. The maximum amplitude of evoked muscle action potentials was also correlated with age. This novel method may be useful in detecting pathology of motor nerve fibers which results in a decrease in submaximal conduction velocities.

  17. Protein expression of sensory and motor nerves: Two-dimensional gel electrophoresis and mass spectrometry.

    PubMed

    Ren, Zhiwu; Wang, Yu; Peng, Jiang; Zhang, Li; Xu, Wenjing; Liang, Xiangdang; Zhao, Qing; Lu, Shibi

    2012-02-15

    The present study utilized samples from bilateral motor branches of the femoral nerve, as well as saphenous nerves, ventral roots, and dorsal roots of the spinal cord, to detect differential protein expression using two-dimensional gel electrophoresis and nano ultra-high performance liquid chromatography electrospray ionization mass spectrometry tandem mass spectrometry techniques. A mass spectrum was identified using the Mascot search. Results revealed differential expression of 11 proteins, including transgelin, Ig kappa chain precursor, plasma glutathione peroxidase precursor, an unnamed protein product (gi|55628), glyceraldehyde-3-phosphate dehydrogenase-like protein, lactoylglutathione lyase, adenylate kinase isozyme 1, two unnamed proteins products (gi|55628 and gi|1334163), and poly(rC)-binding protein 1 in motor and sensory nerves. Results suggested that these proteins played roles in specific nerve regeneration following peripheral nerve injury and served as specific markers for motor and sensory nerves.

  18. Motorized head impulse stimulator to determine angular horizontal vestibulo-ocular reflex.

    PubMed

    Aalto, H; Hirvonen, T; Juhola, M

    2002-01-01

    The objective of the current study was to develop a computer-controlled mechanical system for the generation of impulsive head rotations to measure eye movements induced by angular horizontal vestibulo-ocular reflex. This is a clinical eye movement test recently introduced for the usage of otoneurological balance laboratories. We built the system and modified our prior computer software developed for other types of eye movement tests. Motor controlled stimulation has fulfilled the requirement of more uniform and constant acceleration stimulation than obtained with manually administrated impulses. After having executed preliminary experiments at our balance laboratory we found the system to be efficient, reliable and secure.

  19. Comparative proteomic analysis of differentially expressed proteins between peripheral sensory and motor nerves.

    PubMed

    He, Qianru; Man, Lili; Ji, Yuhua; Zhang, Shuqiang; Jiang, Maorong; Ding, Fei; Gu, Xiaosong

    2012-06-01

    Peripheral sensory and motor nerves have different functions and different approaches to regeneration, especially their distinct ability to accurately reinervate terminal nerve pathways. To understand the molecular aspects underlying these differences, the proteomics technique by coupling isobaric tags for relative and absolute quantitation (iTRAQ) with online two-dimensional liquid chromatography tandem mass spectrometry (2D LC-MS/MS) was used to investigate the protein profile of sensory and motor nerve samples from rats. A total of 1472 proteins were identified in either sensory or motor nerve. Of them, 100 proteins showed differential expressions between both nerves, and some of them were validated by quantitative real time RT-PCR, Western blot analysis, and immunohistochemistry. In the light of functional categorization, the differentially expressed proteins in sensory and motor nerves, belonging to a broad range of classes, were related to a diverse array of biological functions, which included cell adhesion, cytoskeleton, neuronal plasticity, neurotrophic activity, calcium-binding, signal transduction, transport, enzyme catalysis, lipid metabolism, DNA-binding, synaptosome function, actin-binding, ATP-binding, extracellular matrix, and commitment to other lineages. The relatively higher expressed proteins in either sensory or motor nerve were tentatively discussed in combination with their specific molecular characteristics. It is anticipated that the database generated in this study will provide a solid foundation for further comprehensive investigation of functional differences between sensory and motor nerves, including the specificity of their regeneration.

  20. Morphological study of external oblique motor nerves and nuclei in cats.

    PubMed

    Niwa, Masatoshi; Nakayama, Kiyomi; Sasaki, Sei-Ichi

    2008-03-01

    In order to clarify the morphological features of peripheral motor nerves and motoneurons that innervate trunk muscles, the size distribution of external oblique (EO) peripheral motor fibers and motoneurons of the thoracic and the lumbar segments were examined. Histograms of the size distribution of EO motor fibers in peripheral nerves after ganglionectomy clearly had a bimodal distribution of small fiber groups and large fiber groups. It is very likely that small fiber groups correspond to gamma motor fibers and large fiber groups to alpha motor fibers. Gamma and alpha motor fiber groups were separated at 8-14 microm. The average diameter of the gamma and alpha motor fibers were different in each segment. The ratio of gamma and alpha motor fibers was approximately 1:2.0 in the thoracic segments and from 1:1.8 to 1:0.9 in the lumbar segments. Horseradish peroxidase was applied to the central stump of EO nerves, and the size distribution of EO motoneuron cell bodies in the thoracic and the lumbar spinal cords was examined. The size distribution of motoneuron cell bodies was bimodal in one cat (small and large motoneurons) and unimodal in three cats. When the ratio of small motor fibers to large motor fibers in peripheral nerves was applied to that of small motoneurons to large motoneurons, the separation of small and large motoneurons was approximately 40 microm. These results suggest that the morphological characteristics in peripheral nerves of trunk muscles are not reflected in motoneurons.

  1. Motor unit estimation in a muscle supplied by the radial nerve.

    PubMed Central

    Defaria, C R; Toyonaga, K

    1978-01-01

    The number of motor units in a muscle, the abductor pollicis longus (APL), supplied by the radial nerve was estimated. In 40 APL muscles of control subjects, the mean number of motor units was found to be 421 +/- 99 (SD). Ten patients underwent conventional EMG examination to confirm the clinical suspicion of denervation in radial nerve territory. All presented a significant reduction in the number of motor units in the APL muscle. These results show that this method is useful in the evaluation of muscles supplied by the radial nerve. PMID:690650

  2. Integrin antagonists affect growth and pathfinding of ventral motor nerves in the trunk of embryonic zebrafish.

    PubMed

    Becker, Thomas; McLane, Mary Ann; Becker, Catherina G

    2003-05-01

    Integrins are thought to be important receptors for extracellular matrix (ECM) components on growing axons. Ventral motor axons in the trunk of embryonic zebrafish grow in a midsegmental pathway through an environment rich in ECM components. To test the role of integrins in this process, integrin antagonists (the disintegrin echistatin in native and recombinant form, as well as the Arg-Gly-Asp-Ser peptide) were injected into embryos just prior to axon outgrowth at 14-16 h postfertilization (hpf). All integrin antagonists affected growth of ventral motor nerves in a similar way and native echistatin was most effective. At 24 hpf, when only the three primary motor axons per trunk hemisegment had grown out, 80% (16 of 20) of the embryos analyzed had abnormal motor nerves after injection of native echistatin, corresponding to 19% (91 of 480) of all nerves. At 33 hpf, when secondary motor axons were present in the pathway, 100% of the embryos were affected (24 of 24), with 20% of all nerves analyzed (196 of 960) being abnormal. Phenotypes comprised abnormal branching (64% of all abnormal nerves) and truncations (36% of all abnormal nerves) of ventral motor nerves at 24 hpf and mostly branching of the nerves at 33 hpf (94% of all abnormal nerves). Caudal branches were at least twice as frequent as rostral branches. Surrounding trunk tissue and a number of other axon fascicles were apparently not affected by the injections. Thus integrin function contributes to both growth and pathfinding of axons in ventral motor nerves in the trunk of zebrafish in vivo.

  3. Vagus nerve stimulation delivered during motor rehabilitation improves recovery in a rat model of stroke.

    PubMed

    Khodaparast, Navid; Hays, Seth A; Sloan, Andrew M; Fayyaz, Tabbassum; Hulsey, Daniel R; Rennaker, Robert L; Kilgard, Michael P

    2014-09-01

    Neural plasticity is widely believed to support functional recovery following brain damage. Vagus nerve stimulation paired with different forelimb movements causes long-lasting map plasticity in rat primary motor cortex that is specific to the paired movement. We tested the hypothesis that repeatedly pairing vagus nerve stimulation with upper forelimb movements would improve recovery of motor function in a rat model of stroke. Rats were separated into 3 groups: vagus nerve stimulation during rehabilitation (rehab), vagus nerve stimulation after rehab, and rehab alone. Animals underwent 4 training stages: shaping (motor skill learning), prelesion training, postlesion training, and therapeutic training. Rats were given a unilateral ischemic lesion within motor cortex and implanted with a left vagus nerve cuff. Animals were allowed 1 week of recovery before postlesion baseline training. During the therapeutic training stage, rats received vagus nerve stimulation paired with each successful trial. All 17 trained rats demonstrated significant contralateral forelimb impairment when performing a bradykinesia assessment task. Forelimb function was recovered completely to prelesion levels when vagus nerve stimulation was delivered during rehab training. Alternatively, intensive rehab training alone (without stimulation) failed to restore function to prelesion levels. Delivering the same amount of stimulation after rehab training did not yield improvements compared with rehab alone. These results demonstrate that vagus nerve stimulation repeatedly paired with successful forelimb movements can improve recovery after motor cortex ischemia and may be a viable option for stroke rehabilitation.

  4. Identification of Changes in Gene expression of rats after Sensory and Motor Nerves Injury.

    PubMed

    Wang, Yu; Guo, Zhi-Yuan; Sun, Xun; Lu, Shi-Bi; Xu, Wen-Jing; Zhao, Qing; Peng, Jiang

    2016-06-02

    Wallerian degeneration is a sequence of events in the distal stump of axotomized nerves. Despite large numbers of researches concentrating on WD, the biological mechanism still remains unclear. Hence we constructed a rat model with both motor and sensory nerves injury and then conducted a RNA-seq analysis. Here the rats were divided into the 4 following groups: normal motor nerves (NMN), injured motor nerves (IMN), normal sensory nerves (NSN) and injured sensory nerves (ISN). The transcriptomes of rats were sequenced by the Illumina HiSeq. The differentially expressed genes (DEGs) of 4 combinations including NMN vs. IMN, NSN vs. ISN, NMN vs. NSN and IMN vs. ISN were identified respectively. For the above 4 combinations, we identified 1666, 1514, 95 and 17 DEGs. We found that NMN vs. IMN shared the most common genes with NSN vs. ISN indicating common mechanisms between motor nerves injury and sensory nerves injury. At last, we performed an enrichment analysis and observed that the DEGs of NMN vs IMN and NSN vs. ISN were significantly associated with binding and activity, immune response, biosynthesis, metabolism and development. We hope our study may shed light on the molecular mechanisms of nerves degeneration and regeneration during WD.

  5. Synergistic motor nerve fiber transfer between different nerves through the use of end-to-side coaptation.

    PubMed

    Schmidhammer, R; Nógrádi, A; Szabó, A; Redl, H; Hausner, T; van der Nest, D G; Millesi, H

    2009-06-01

    End-to-end nerve repair is a widely used and successful experimental microsurgical technique via which a denervated nerve stump is supplied with reinnervating motor or sensory axons. On the other hand, questions are still raised as concerns the reliability and usefulness of the end-to-side coaptation technique. This study had the aim of the reinnervation of the denervated forearm flexor muscles in baboons through the use of an end-to-side coaptation technique and the synergistic action of the radial nerve. The median and ulnar nerves were transected, and the motor branch of the radial nerve supplying the extensor carpi radialis muscles (MBECR) was used as an axon donor for the denervated superficial forearm flexors. A nerve graft was connected to the axon donor nerve through end-to-side coaptation, while at the other end of the graft an end-to-end connection was established so as to reinnervate the motor branch of the forearm flexors. Electrophysiological investigations and functional tests indicated successful reinnervation of the forearm flexors and recovery of the flexor function. The axon counts in the nerve segments proximal (1038+/-172 S.E.M.) and distal (1050+/-116 S.E.M.) to the end-to-side coaptation site and in the nerve graft revealed that motor axon collaterals were given to the graft without the loss or appreciable misdirection of the axons in the MBECR nerve distal to the coaptation site. The nerve graft was found to contain varying, but satisfactory numbers of axons (269+/-59 S.E.M.) which induced morphological reinnervation of the end-plates in the flexor muscles. Accordingly, we have provided evidence that end-to-side coaptation can be a useful technique when no free donor nerve is available. This technique is able to induce limited, but still useful reinnervation for the flexor muscles, thereby producing a synergistic action of the flexor and extensor muscles which allows the hand to achieve a basic gripping function.

  6. Accuracy of regenerating motor neurons: influence of diffusion in denervated nerve.

    PubMed

    Madison, R D; Robinson, G A

    2014-07-25

    Following injury to a peripheral nerve the denervated distal nerve segment undergoes remarkable changes including loss of the blood-nerve barrier, Schwann cell proliferation, macrophage invasion, and the production of many cytokines and neurotrophic factors. The aggregate consequence of such changes is that the denervated nerve becomes a permissive and even preferred target for regenerating axons from the proximal nerve segment. The possible role that an original end-organ target (e.g. muscle) may play in this phenomenon during the regeneration period is largely unexplored. We used the rat femoral nerve as an in vivo model to begin to address this question. We also examined the effects of disrupting communication with muscle in terms of accuracy of regenerating motor neurons as judged by their ability to correctly project to their original terminal nerve branch. Our results demonstrate that the accuracy of regenerating motor neurons is dependent upon the denervated nerve segment remaining in uninterrupted continuity with muscle. We hypothesized that this influence of muscle on the denervated nerve might be via diffusion-driven movement of biomolecules or the active axonal transport that continues in severed axons for several days in the rat, so we devised experiments to separate these two possibilities. Our data show that disrupting ongoing diffusion-driven movement in a denervated nerve significantly reduces the accuracy of regenerating motor neurons. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  7. Unexpected motor axons in the distal superficial radial and posterior interosseous nerves: a cadaver study.

    PubMed

    Okwueze, Martina I; Cardwell, Nancy L; Wolfort, Sean L; Nanney, Lillian B

    2007-10-01

    The prevalence of motor variations in the nerves supplying muscles of the first web space was evaluated by a visual dissection and immunohistochemical analysis from 56 cadaver hands. By microscopic visualization, 30% of the superficial radial nerves (SRNs) sent branches into muscles of the first web space. Since these unexpected penetrating branches were expected to be sensory or proprioceptive, markers of sensory and motor axons were used for confirmation. Positive identifications of motor axons (as identified by positive immunostaining for choline acetyltransferase) were made in 30% of SRNs and in 28.5% of posterior interosseous nerves. Classical teachings that the SRNs and PINs are exclusively sensory have been brought into question. Our data are in agreement with the rare clinical finding that motor function occasionally persists following devastating injury to both the ulnar and median nerves. Anatomic prevalence for this variation appears much higher than previous descriptions have indicated.

  8. Immune response against ocular tissues after immunization with optic nerve antigens in a model of autoimmune glaucoma

    PubMed Central

    Reinehr, Sabrina; Kuehn, Sandra; Laspas, Panagiotis; Gramlich, Oliver W.; Kuehn, Mathias; Tischoff, Iris; von Pein, Harald D.; Dick, H. Burkhard; Grus, Franz H.

    2013-01-01

    Purpose In recent years, numerous studies have investigated the involvement of immunological mechanisms in glaucoma. Until now, it has not been determined whether the altered antibody pattern detected in patients is harmful to retinal ganglion cells (RGCs) or triggers disease formation in any way. In a model of experimental autoimmune glaucoma, RGC loss can be induced through immunization with certain ocular antigens. In the current study, the time course of the levels of autoreactivity against ocular tissues after immunization was examined. Methods Intraocular pressure was measured regularly. Ten weeks after immunization with an optic nerve homogenate antigen (ONA), the number of RGCs was determined. Immunoglobulin G levels in aqueous humor were measured via enzyme-linked immunosorbent assay at the same time point. Serum from different time points was used to analyze the possible occurrence of autoreactive antibodies against the retina or optic nerve in this autoimmune glaucoma model. Additionally, optic nerve and brain sections were evaluated for possible pathological findings. Results Intraocular pressure stayed within the normal range throughout this study. A continuous increase of autoreactive antibodies against the optic nerve and retina sections was observed. At 4, 6, and 10 weeks, antibody reactivity was significantly higher in ONA animals (p<0.01). Aqueous humor immunoglobulin G levels were also significantly higher in the ONA group (p=0.006). Ten weeks after immunization, significantly fewer RGCs were noted in the ONA group (p=0.00003). The optic nerves from ONA animals exhibited damaged axons. No pathological findings appeared in any brain sections. Conclusions Our findings suggest that these modified antibodies play a substantial role in mechanisms leading to RGC death. The slow dissolution of RGCs observed in animals with autoimmune glaucoma is comparable to the slow progressive RGC loss in glaucoma patients, thus making this a useful model to develop

  9. Changes in angle of optic nerve and angle of ocular orbit with increasing age in Japanese children

    PubMed Central

    Tsukitome, Hideyuki; Hatsukawa, Yoshikazu; Morimitsu, Tomoko; Yagasaki, Teiji; Kondo, Mineo

    2015-01-01

    Purpose To study changes in the opening angle of the optic nerve and the angle of the ocular orbit with increasing age in normal Japanese children. Methods We studied 147 normal children (aged 6 months to 18 years) who had undergone CT as a diagnostic procedure. Measurements were performed on axial CT images that included the entire optic nerve of both eyes. The opening angle of the optic nerve was defined as the angle formed by the intersection of a line running through the left optic nerve and a vertical line passing through the centre of the nose. The opening angle of the orbit was defined as the angle formed by the intersection of a line running tangentially along the deep lateral wall of the left orbit and a vertical line passing through the centre of the nose. The relationship between age and these opening angles was analysed by regression analysis. Results The correlation between age and opening angle of the optic nerve was not significant. In contrast, the opening angle of the orbit decreased relatively rapidly until about 2–3 years of age, and then it stabilised. The decrease in the opening angle of the orbit with increasing age was significant (p<0.001). The relationship between these two parameters was best fitted by a logarithmic regression curve. Conclusions Because the opening angle of the orbit decreased significantly with increasing age, this factor must be considered when diagnosing and treating strabismus in children. PMID:25147368

  10. Processed nerve allografts for peripheral nerve reconstruction: a multicenter study of utilization and outcomes in sensory, mixed, and motor nerve reconstructions.

    PubMed

    Brooks, Darrell N; Weber, Renata V; Chao, Jerome D; Rinker, Brian D; Zoldos, Jozef; Robichaux, Michael R; Ruggeri, Sebastian B; Anderson, Kurt A; Bonatz, Ekkehard E; Wisotsky, Scott M; Cho, Mickey S; Wilson, Christopher; Cooper, Ellis O; Ingari, John V; Safa, Bauback; Parrett, Brian M; Buncke, Gregory M

    2012-01-01

    As alternatives to autograft become more conventional, clinical outcomes data on their effectiveness in restoring meaningful function is essential. In this study we report on the outcomes from a multicenter study on processed nerve allografts (Avance® Nerve Graft, AxoGen, Inc). Twelve sites with 25 surgeons contributed data from 132 individual nerve injuries. Data was analyzed to determine the safety and efficacy of the nerve allograft. Sufficient data for efficacy analysis were reported in 76 injuries (49 sensory, 18 mixed, and 9 motor nerves). The mean age was 41 ± 17 (18-86) years. The mean graft length was 22 ± 11 (5-50) mm. Subgroup analysis was performed to determine the relationship to factors known to influence outcomes of nerve repair such as nerve type, gap length, patient age, time to repair, age of injury, and mechanism of injury. Meaningful recovery was reported in 87% of the repairs reporting quantitative data. Subgroup analysis demonstrated consistency, showing no significant differences with regard to recovery outcomes between the groups (P > 0.05 Fisher's Exact Test). No graft related adverse experiences were reported and a 5% revision rate was observed. Processed nerve allografts performed well and were found to be safe and effective in sensory, mixed and motor nerve defects between 5 and 50 mm. The outcomes for safety and meaningful recovery observed in this study compare favorably to those reported in the literature for nerve autograft and are higher than those reported for nerve conduits. Copyright © 2011 Wiley-Liss, Inc.

  11. The effects of general anaesthesia on nerve-motor response characteristics (rheobase and chronaxie) to peripheral nerve stimulation.

    PubMed

    Tsui, B C

    2014-04-01

    Using a simple surface nerve stimulation system, I examined the effects of general anaesthesia on rheobase (the minimum current required to stimulate nerve activity) and chronaxie (the minimum time for a stimulus twice the rheobase to elicit nerve activity). Nerve stimulation was used to elicit a motor response from the ulnar nerve at varying pulse widths before and after induction of general anaesthesia. Mean (SD) rheobase before and after general anaesthesia was 0.91 (0.37) mA (95% CI 0.77-1.04 mA) and 1.11 (0.53) mA (95% CI 0.92-1.30 mA), respectively. Mean (SD) chronaxie measured before and after general anaesthesia was 0.32 (0.17) ms (95% CI 0.26-0.38 ms) and 0.29 (0.13) ms (95% CI 0.24-0.33 ms), respectively. Under anaesthesia, rheobase values increased by an average of 20% (p = 0.05), but chronaxie values did not change significantly (p = 0.39). These results suggest that threshold currents used for motor response from nerve stimulation under general anaesthesia might be higher than those used in awake patients. © 2014 The Association of Anaesthetists of Great Britain and Ireland.

  12. Effects of lead acetate on guinea pig - cochear microphonics, action potential, and motor nerve conduction velocity

    SciTech Connect

    Yamamura, K.; Maehara, N.; Terayama, K.; Ueno, N.; Kohyama, A.; Sawada, Y.; Kishi, R.

    1987-04-01

    Segmental demyelination and axonal degeneration of motor nerves induced by lead exposure is well known in man, and animals. The effect of lead acetate exposure to man may involve the cranial nerves, since vertigo and sensory neuronal deafness have been reported among lead workers. However, there are few reports concerning the dose-effects of lead acetate both to the peripheral nerve and the cranial VII nerve with measurement of blood lead concentration. The authors investigated the effects of lead acetate to the cochlea and the VIII nerve using CM (cochlear microphonics) and AP (action potential) of the guinea pigs. The effects of lead acetate to the sciatic nerve were measured by MCV of the sciatic nerve with measurement of blood lead concentration.

  13. Magnetic stimulation of the human motor cortex evokes skin sympathetic nerve activity.

    PubMed

    Silber, D H; Sinoway, L I; Leuenberger, U A; Amassian, V E

    2000-01-01

    Single-pulse magnetic coil stimulation (Cadwell MES 10) over the cranium induces without pain an electric pulse in the underlying cerebral cortex. Stimulation over the motor cortex can elicit a muscle twitch. In 10 subjects, we tested whether motor cortical stimulation could also elicit skin sympathetic nerve activity (SSNA; n = 8) and muscle sympathetic nerve activity (MSNA; n = 5) in the peroneal nerve. Focal motor cortical stimulation predictably elicited bursts of SSNA but not MSNA; with successive stimuli, the SSNA responses did not readily extinguish (94% of discharges to the motor cortex evoked SSNA responses) and had predictable latencies [739 +/- 33 (SE) to 895 +/- 13 ms]. The SSNA responses were similar after stimulation of dominant and nondominant sides. Focal stimulation posterior to the motor cortex elicited extinguishable SSNA responses. In three of six subjects, anterior cortical stimulation evoked SSNA responses similar to those seen with motor cortex stimulation but without detectable movement; in the other subjects, anterior stimulation evoked less SSNA discharge than that seen with motor cortex stimulation. Contrasting with motor cortical stimulation, evoked SSNA responses were more readily extinguished with 1) peripheral stimulation that directly elicited forearm muscle activation accompanied by electromyograms similar to those with motor cortical stimulation; 2) auditory stimulation by the click of the energized coil when off the head; and 3) in preliminary experiments, finger afferent stimulation sufficient to cause tingling. Our findings are consistent with the hypothesis that motor cortex stimulation can cause activation of both alpha-motoneurons and SSNA.

  14. Patterns of motor activity in the isolated nerve cord of the octopus arm.

    PubMed

    Gutfreund, Yoram; Matzner, Henry; Flash, Tamar; Hochner, Binyamin

    2006-12-01

    The extremely flexible octopus arm provides a unique opportunity for studying movement control in a highly redundant motor system. We describe a novel preparation that allows analysis of the peripheral nervous system of the octopus arm and its interaction with the muscular and mechanosensory elements of the arm's intrinsic muscular system. First we examined the synaptic responses in muscle fibers to identify the motor pathways from the axial nerve cord of the arm to the surrounding musculature. We show that the motor axons project to the muscles via nerve roots originating laterally from the arm nerve cord. The motor field of each nerve is limited to the region where the nerve enters the arm musculature. The same roots also carry afferent mechanosensory information from the intrinsic muscle to the axial nerve cord. Next, we characterized the pattern of activity generated in the dorsal roots by electrically stimulating the axial nerve cord. The evoked activity, although far reaching and long lasting, cannot alone account for the arm extension movements generated by similar electrical stimulation. The mismatch between patterns of activity in the isolated cord and in an intact arm may stem from the involvement of mechanosensory feedback in natural arm extension.

  15. Peripheral Nerve Injury in Developing Rats Reorganizes Representation Pattern in Motor Cortex

    NASA Astrophysics Data System (ADS)

    Donoghue, John P.; Sanes, Jerome N.

    1987-02-01

    We investigated the effect of neonatal nerve lesions on cerebral motor cortex organization by comparing the cortical motor representation of normal adult rats with adult rats that had one forelimb removed on the day of birth. Mapping of cerebral neocortex with electrical stimulation revealed an altered relationship between the motor cortex and the remaining muscles. Whereas distal forelimb movements are normally elicited at the lowest threshold in the motor cortex forelimb area, the same stimuli activated shoulder and trunk muscles in experimental animals. In addition, an expanded cortical representation of intact body parts was present and there was an absence of a distinct portion of motor cortex. These data demonstrate that representation patterns in motor cortex can be altered by peripheral nerve injury during development.

  16. Effects of brevetoxin-B on motor nerve terminals of mouse skeletal muscle.

    PubMed Central

    Tsai, M. C.; Chen, M. L.

    1991-01-01

    1. The effects of brevetoxin-B, a red tide toxin, on motor nerve terminal activity were assessed on mouse triangularis sterni nerve-muscle preparations. The perineural waveforms were recorded with extracellular electrodes placed in the perineural sheaths of motor nerves. 2. At 0.11 microM, brevetoxin-B increased the components of waveforms associated with sodium and potassium currents while it decreased the calcium activated potassium current and the slow calcium current of the nerve terminal. The fast calcium current and slow potassium current were not affected. 3. At 1.11 microM, brevetoxin-B decreased all of the components of waveforms associated with sodium, potassium and calcium currents. 4. It is concluded that brevetoxin-B affects sodium, potassium as well as calcium currents in the nerve terminal. The effects may contribute to its pharmacological actions on synaptic transmission. PMID:1652340

  17. Sub-lethal Ocular Trauma (SLOT): Establishing a Standardized Blast Threshold to Facilitate Diagnostic, Early Treatment, and Recovery Studies for Blast Injuries to the Eye and Optic Nerve

    DTIC Science & Technology

    2015-11-01

    Early Treatment , and Recovery Studies for Blast Injuries to the Eye and Optic Nerve PRINCIPAL INVESTIGATOR: Walt Gray, Ph.D. CONTRACTING...lethal Ocular Trauma (SLOT): Establishing a Standardized Blastr 5a. CONTRACT NUMBER Threshold to Facilitate Diagnostic, Early Treatment , and Recovery...Establishing a Standardized Blast Threshold to Facilitate Diagnostic, early Treatment , and Recovery Studies for Blast Injurieσ to the Eye and Optic Nerve

  18. Accommodation to hyperpolarizing currents: differences between motor and sensory nerves in mice.

    PubMed

    Nodera, Hiroyuki; Rutkove, Seward B

    2012-06-19

    Peripheral motor nerves have revealed variability in excitability by hyperpolarizing current at specific target response levels, likely reflecting differences in the hyperpolarization-activated current (Ih). Whether such variability in Ih exists in sensory axons is yet to be established. We performed nerve excitability testing in mouse tail motor and sensory nerves at 3 target response levels (20, 40, and 60% of the maximum amplitudes). Target-level dependent variability was present by long hyperpolarizing currents in motor and sensory nerves in which the recording at the low target level showed smaller threshold changes than at the high target level. Other excitability measures, however, showed no variability. Furthermore, the accommodation by long, strong hyperpolarization revealed smaller S3 accommodation (threshold change between the maximum and at the end of the 200 ms conditioning pulse) at the low target response level in sensory axons, but not in motor axons. Variation in the kinetics of the subtypes of the hyperpolarization-activated cyclic nucleotide-gated (HCN) channels in motor and sensory axons is the most likely explanation for these findings. The present study has proposed that nerve excitability testing may provide a non-invasive means for the assessment of the different types of Ih in neurological disorders where HCN subtypes play unique pathophysiological roles.

  19. Motor affliction of the L5 nerve root in lumbar nerve root compression syndromes.

    PubMed

    Jönsson, B; Strömqvist, B

    1995-09-15

    From a prospective and consecutive study on degenerative lumbar spine disorders containing 416 patients, all patients with a severely reduced or absent strength of the extensor hallucis longus muscle (n = 35) before surgery were identified. The incidence, diagnosis, and recovery after surgery of patients with L5 root compression syndromes and a severely reduced or absent power before surgery of the big toe extensor was evaluated. The L5 root is commonly involved in disc herniation and central and lateral spinal stenosis. Whether motor recovery occurs after root decompression is not fully known. All patients underwent a conventional radiologic evaluation before surgery including one or more myelography, computed tomography scan, and magnetic resonance imaging. At examination before surgery, extensor hallucis longus-power was graded as normal, reduced, or severely reduced/absent, and the latter group is presented here. Surgical findings were registered. Clinical investigation was performed after 4, 12-, and 24-month follow-up periods. A pronounced extensor hallucis longus paresis was seen in disc herniation in 20 of 187 patients, in lateral spinal stenosis in 10 of 122 patients, and central spinal stenosis 5 of 107 patients. Improvement of the paresis after surgery was equally common in disc herniation (15 of 20 patients) and lateral spinal stenosis (7 of 10 patients). Complete restitution was more common in disc herniation. None of the five patients with central spinal stenosis improved concerning paresis at the follow-up period. Improvement was most common during the first 4 months after surgery. No correlation between age or preoperative symptom duration and recovery was noted in either group. The incidence of pronounced extensor hallucis longus paresis in lumbar nerve root compression varied between 5-11%. Recovery after surgery was common in disc herniation and lateral spinal stenosis but did not occur in central stenosis. Complete recovery was most common in

  20. Changes in angle of optic nerve and angle of ocular orbit with increasing age in Japanese children.

    PubMed

    Tsukitome, Hideyuki; Hatsukawa, Yoshikazu; Morimitsu, Tomoko; Yagasaki, Teiji; Kondo, Mineo

    2015-02-01

    To study changes in the opening angle of the optic nerve and the angle of the ocular orbit with increasing age in normal Japanese children. We studied 147 normal children (aged 6 months to 18 years) who had undergone CT as a diagnostic procedure. Measurements were performed on axial CT images that included the entire optic nerve of both eyes. The opening angle of the optic nerve was defined as the angle formed by the intersection of a line running through the left optic nerve and a vertical line passing through the centre of the nose. The opening angle of the orbit was defined as the angle formed by the intersection of a line running tangentially along the deep lateral wall of the left orbit and a vertical line passing through the centre of the nose. The relationship between age and these opening angles was analysed by regression analysis. The correlation between age and opening angle of the optic nerve was not significant. In contrast, the opening angle of the orbit decreased relatively rapidly until about 2-3 years of age, and then it stabilised. The decrease in the opening angle of the orbit with increasing age was significant (p<0.001). The relationship between these two parameters was best fitted by a logarithmic regression curve. Because the opening angle of the orbit decreased significantly with increasing age, this factor must be considered when diagnosing and treating strabismus in children. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  1. Inhibition of Rho-kinase differentially affects axon regeneration of peripheral motor and sensory nerves.

    PubMed

    Joshi, Abhijeet R; Bobylev, Ilja; Zhang, Gang; Sheikh, Kazim A; Lehmann, Helmar C

    2015-01-01

    The small GTPase RhoA and its down-stream effector Rho-kinase (ROCK) are important effector molecules of the neuronal cytoskeleton. Modulation of the RhoA/ROCK pathway has been shown to promote axonal regeneration, however in vitro and animal studies are inconsistent regarding the extent of axonal outgrowth induced by pharmacological inhibition of ROCK. We hypothesized that injury to sensory and motor nerves result in diverse activation levels of RhoA, which may impact the response of those nerve fiber modalities to ROCK inhibition. We therefore examined the effects of Y-27632, a chemical ROCK inhibitor, on the axonal outgrowth of peripheral sensory and motor neurons grown in the presence of growth-inhibiting chondroitin sulfate proteoglycans (CSPGs). In addition we examined the effects of three different doses of Y-27632 on nerve regeneration of motor and sensory nerves in animal models of peripheral nerve crush. In vitro, sensory neurons were less responsive to Y-27632 compared to motor neurons in a non-growth permissive environment. These differences were associated with altered expression and activation of RhoA in sensory and motor axons. In vivo, systemic treatment with high doses of Y-27632 significantly enhanced the regeneration of motor axons over short distances, while the regeneration of sensory fibers remained largely unchanged. Our results support the concept that in a growth non-permissive environment, the regenerative capacity of sensory and motor axons is differentially affected by the RhoA/ROCK pathway, with motor neurons being more responsive compared to sensory. Future treatments, that are aimed to modulate RhoA activity, should consider this functional diversity.

  2. Cognitive requirements for vestibular and ocular motor processing in healthy adults and patients with unilateral vestibular lesions.

    PubMed

    Talkowski, M E; Redfern, M S; Jennings, J R; Furman, J M

    2005-09-01

    This study investigated the role of cognition in the vestibulo-ocular reflex (VOR) and ocular pursuit using a dual-task paradigm in patients with unilateral peripheral vestibular loss and healthy adults. We hypothesized that cognitive resources are involved in successful processing and integration of vestibular and ocular motor sensory information, and this requirement would be greater in patients with vestibular dysfunction. Sixteen well-compensated patients with surgically confirmed absent unilateral peripheral vestibular function and 16 healthy age- and sex-matched controls underwent seven combinations of vestibular-only, visual-only, and visual-vestibular stimuli while performing three different information processing tasks. Visual-vestibular stimuli included a semicircular canal and an otolith stimulus provided through seated chair rotations; fixation on a laser target and sinusoidal smooth pursuit while still; and fixation on a head-fixed laser target during chair rotations. The information processing tasks were three different auditory reaction time (RT) tasks: (1) simple RT, (2) disjunctive RT, and (3) choice RT. Our results showed increases in RTs in both patients and controls under all vestibular-only stimulation conditions and during ocular pursuit. Patients showed greater increases in RTs during vestibular stimulation and the more complex disjunctive and choice RT tasks. No differences between the groups were found during the visual-only or visual-vestibular interaction conditions. These results reveal interference between vestibulo-ocular processing and a concurrent RT task, suggesting that the VOR and the ocular motor system are dependent upon cognitive resources to some extent, and thus, are not fully automatic systems. We speculate that this interference with cognition occurs as a result of the sensory integration required for resolving inputs from multiple sensory streams. The particularly large decrement in information processing task performance

  3. Motor nerves of the head and neck that are susceptible to damage during dermatological surgery.

    PubMed

    Brown, S M; Oliphant, T; Langtry, J

    2014-08-01

    As the incidence of non melanoma skin cancer rises, dermatologists will increasingly be called upon to perform excisions in the head and neck region. Damage to the motor nerves of the head and neck represents an important adverse event for patients, and a source of litigation for surgeons. Understanding the anatomy of this region is key to counselling patients about the possibility of motor nerve injury associated with particular skin surgical procedures. We describe the anatomy of the motor nerves of the head and neck that are most vulnerable to injury during dermatological surgery. The consequences of injury are outlined, and the surface anatomy and anatomical landmarks that may be used to identify the relevant danger zones are described.

  4. Variations in the motor nerve supply of the thenar and hypothenar muscles of the hand.

    PubMed Central

    Ajmani, M L

    1996-01-01

    The distribution pattern of the muscular branch of median and ulnar nerves and motor innervation of the thenar and hypothenar muscles were studied in 68 palmar regions taken from 34 adult cadavers of both sexes aged 40 to 70 y. The structure of the flexor pollicis brevis was examined in all 68 hands. In 13 of the 68 hands an anastomosis was seen between the ulnar and median nerves. Images Fig. 3 Fig. 4 PMID:8771405

  5. Factors predicting sensory and motor recovery after the repair of upper limb peripheral nerve injuries

    PubMed Central

    He, Bo; Zhu, Zhaowei; Zhu, Qingtang; Zhou, Xiang; Zheng, Canbin; Li, Pengliang; Zhu, Shuang; Liu, Xiaolin; Zhu, Jiakai

    2014-01-01

    OBJECTIVE: To investigate the factors associated with sensory and motor recovery after the repair of upper limb peripheral nerve injuries. DATA SOURCES: The online PubMed database was searched for English articles describing outcomes after the repair of median, ulnar, radial, and digital nerve injuries in humans with a publication date between 1 January 1990 and 16 February 2011. STUDY SELECTION: The following types of article were selected: (1) clinical trials describing the repair of median, ulnar, radial, and digital nerve injuries published in English; and (2) studies that reported sufficient patient information, including age, mechanism of injury, nerve injured, injury location, defect length, repair time, repair method, and repair materials. SPSS 13.0 software was used to perform univariate and multivariate logistic regression analyses and to investigate the patient and intervention factors associated with outcomes. MAIN OUTCOME MEASURES: Sensory function was assessed using the Mackinnon-Dellon scale and motor function was assessed using the manual muscle test. Satisfactory motor recovery was defined as grade M4 or M5, and satisfactory sensory recovery was defined as grade S3+ or S4. RESULTS: Seventy-one articles were included in this study. Univariate and multivariate logistic regression analyses showed that repair time, repair materials, and nerve injured were independent predictors of outcome after the repair of nerve injuries (P < 0.05), and that the nerve injured was the main factor affecting the rate of good to excellent recovery. CONCLUSION: Predictors of outcome after the repair of peripheral nerve injuries include age, gender, repair time, repair materials, nerve injured, defect length, and duration of follow-up. PMID:25206870

  6. Assessment of temporal dispersion in motor nerves with normal conduction velocity.

    PubMed

    Schulte-Mattler, W J; Jakob, M; Zierz, S

    1999-04-01

    Demyelinated nerves attenuate high-frequency components of propagating action potentials. In order to study if there is diagnostic use of this in motor nerves, the spectral energy above 49 Hz, amplitude, area, and duration of the compound muscle action potentials were measured; values after distal and proximal stimulation of posterior tibial nerves were compared. Normative data were collected in 48 control subjects. The same measurements were made in 20 patients with polyneuropathy and reduced motor nerve conduction velocity, in 21 patients with mild polyneuropathy but normal motor nerve conduction velocity, and in 8 patients with myasthenia gravis. Overall, high-frequency attenuation was closely correlated with amplitude decay (r = 0.63, P<10(-19)) and with increase of action potential duration (r = 0.34, P = 10(-5)). In the group of patients with normal NCV, high-frequency attenuation was abnormal in 9 (43%), amplitude decay was abnormal in two (10%), and area decay was abnormal in one (5%) patient. The action potential duration was normal in all of these patients. High-frequency attenuation was not influenced by stimulus intensity, thus it is not changed by conduction block, and it was not influenced by impaired neuromuscular transmission. Hence, high-frequency attenuation, both sensitively and specifically does indicate abnormal temporal dispersion. In conclusion, the simple measurement of high-frequency attenuation markedly improves detection and characterization of demyelination of human motor fibers.

  7. [Peculiarities of synaptic vesicle recycling in frog and mouse motor nerve terminals].

    PubMed

    Zefirov, A L; Zakharov, A V; Mukhamedzianov, R D; Petrov, A M

    2008-01-01

    Using electrophysiology and fluorescence microscopy (dye FM1-43), comparative study of neurotransmitter secretion, synaptic vesicle exo-endocytosis, and recycling has been carried out in frog and mouse motor nerve terminals during a long strong stimulation (3 min; 20 imp/s). The obtained data have revealed three synaptic vesicle pools and two recycling ways existing on motor nerve terminals. The strong stimulation induced consecutive depletion of readily releasable, mobilized, and reserve vesicle pools of frog nerve terminals. The exocytosis rate exceeded the endocytosis rate; predominant was the slow synaptic vesicle recycling that replenished the reserve pool. In mouse nerve endings, vesicles of the readily releasable and mobilized pools were only exocytosed, the pools being replenished by fast recycling. At the same time, exo- and endocytosis occurred nearly in parallel and vesicles of the reserve pool did not participate in the neurotransmitter secretion. In is suggested that evolution of motor nerve terminals was directed to a decrease of the vesicle pool size, economic spending, and effective reuse of synaptic vesicles. This is achieved by an increase of endocytosis and recycling rates. These features can provide a long maintenance of a quite level of neurotransmitter secretion in nerve terminals of homoiothermal animals to preserve reliability of synaptic transmission during the high-frequency activity.

  8. [Physiological approach to peripheral neuropathy. Conventional nerve conduction studies and magnetic motor root stimulation].

    PubMed

    Ugawa, Yoshikazu

    2004-11-01

    In this communication, I first show some points we should mind in the conventional peripheral nerve conduction studies and later present clinical usefulness of motor root stimulation for peripheral neuropathy. CONVENTIONAL NERVE CONDUCTION STUDIES (NCS): The most important point revealed by the conventional NCSs is whether neuropathy is due to axonal degeneration or demyelinating process. Precise clinical examination with this neurophysiological information leads us to a diagnosis and treatment. Poor clinical examination makes these findings useless. Long standing axonal degeneration sometimes induces secondary demyelination at the most distal part of involved nerves. On the other hand, severe segmental demyelination often provokes secondary axonal degeneration at distal parts to the site of demyelination. These secondary changes show the same abnormal neurophysiological findings as those of the primary involvement. We should be careful of this possibility when interpreting the results of NCS. NCS of sensory nerves is not good at revealing demyelinating process. Mild temporal dispersion of potentials often reduces an amplitude of SNAP or loss of responses, which usually suggests axonal degeneration, because of short duration of sensory nerve potentials. MOTOR ROOT STIMULATION IN PERIPHERAL NEUROPATHY: Magnetic stimulation with a coil placed over the spine activates motor roots and evokes EMG responses from upper and lower limb muscles. The site of activation with this method was determined to be where the motor roots exit from the spinal canal (intervertebral foramina) (J Neurol Neurosurg Psychiatry 52 (9): 1025-1032, 1989) because induced currents are very dense at such a foramen made by electric resistant bones. In several kinds of peripheral neuropathy, this method has been used to detect a lesion at a proximal part of the peripheral nerves which can not be detected by the conventional NCSs. I present a few cases in whom motor root stimulation had a clinical

  9. Multifocal acquired demyelinating sensory and motor neuropathy presenting as a peripheral nerve tumor.

    PubMed

    Allen, David C; Smallman, Clare A; Mills, Kerry R

    2006-09-01

    A man with multifocal acquired demyelinating sensory and motor neuropathy (MADSAM), or Lewis-Sumner syndrome, presented with a progressive left lumbosacral plexus lesion resembling a neurofibroma. After 7 years he developed a left ulnar nerve lesion with conduction block in its upper segment. Treatment with intravenous immunoglobulin improved the symptoms and signs of both lesions. We conclude that inflammatory neuropathy must be considered in the differential diagnosis of peripheral nerve tumors, and that unifocal lesions may precede multifocal involvement in MADSAM by several years. In addition, we discuss the clinical features in 9 patients attending a specialist peripheral nerve clinic and review the literature.

  10. Immunity to nerve growth factor and the effect on motor unit reinnervation in the rabbit.

    PubMed

    Finkelstein, D I; Luff, A R; Schuijers, J A

    1992-05-01

    The trophic effects of nerve growth factor (NGF) on sympathetic, peripheral afferent, and other neural crest-derived cells have been intensively investigated. More recently, NGF has been shown to have an influence on motoneurons. This study was undertaken to investigate whether NGF had any influence on the mechanical or histological properties of reinnervated motor units. Three groups of rabbits were used: normal rabbits, rabbits in which the nerve to medial gastrocnemius (MG) was cut and allowed to reinnervate for 56 days, and rabbits in which the MG nerve reinnervated in the presence of immunity to NGF. Immunity to NGF did not affect the ability of motor axons to reinnervate a muscle, nor were the contractile characteristics of the motor units altered. The size of horseradish peroxidase-labeled motoneurons was not influenced by immunization against NGF; however, the distribution of afferent neuron sizes was altered. Conduction velocity of motor axons proximal to the neuroma was significantly faster after immunization against NGF. Transection and subsequent reinnervation by a peripheral nerve normally causes an increase in myelin thickness proximal to the neuroma. However, immunization against NGF appeared to decrease the magnitude of myelin thickening. It was concluded that immunization against NGF affects motor axonal conduction velocity via an influence on the neural crest-derived Schwann cells.

  11. Behavioral and Neural Plasticity of Ocular Motor Control: Changes in Performance and fMRI Activity Following Antisaccade Training

    PubMed Central

    Jamadar, Sharna D.; Johnson, Beth P.; Clough, Meaghan; Egan, Gary F.; Fielding, Joanne

    2015-01-01

    The antisaccade task provides a model paradigm that sets the inhibition of a reflexively driven behavior against the volitional control of a goal-directed behavior. The stability and adaptability of antisaccade performance was investigated in 23 neurologically healthy individuals. Behavior and brain function were measured using functional magnetic resonance imaging (fMRI) prior to and immediately following 2 weeks of daily antisaccade training. Participants performed antisaccade trials faster with no change in directional error rate following 2 weeks of training; however this increased speed came at the cost of the spatial accuracy of the saccade (gain) which became more hypometric following training. Training on the antisaccade task resulted in increases in fMRI activity in the fronto-basal ganglia-parietal-cerebellar ocular motor network. Following training, antisaccade latency was positively associated with fMRI activity in the frontal and supplementary eye fields, anterior cingulate and intraparietal sulcus; antisaccade gain was negatively associated with fMRI activity in supplementary eye fields, anterior cingulate, intraparietal sulcus, and cerebellar vermis. In sum, the results suggest that following training, larger antisaccade latency is associated with larger activity in fronto-parietal-cerebellar ocular motor regions, and smaller antisaccade gain is associated with larger activity in fronto-parietal ocular motor regions. PMID:26733841

  12. Treatment of transected peripheral nerves with artemin improved motor neuron regeneration, but did not reduce nerve injury-induced pain behaviour.

    PubMed

    Widenfalk, Johan; Wu, Weiping; Hao, Jingxia; Person, Jonas K E; Wiesenfeldt-Hallin, Zsuzsanna; Risling, Mårten

    2009-01-01

    Incomplete recovery of function and neuropathic pain are common problems after peripheral nerve injury. To develop new treatment strategies for peripheral nerve injuries we investigated whether the neurotrophic factor artemin could improve outcome after sciatic nerve injuries in rats. Artemin is a member of the glial cell line-derived neurotrophic factor (GDNF) family and exerts neuroprotective effects on sensory neurons as well as influencing behavioural thermal sensitivity. We additionally evaluated if fibrin sealant, which is sometimes used as a nerve glue, had any effects on neuropathic pain-related behaviour. After the sciatic nerve had been transected, 30 animals were randomised to one of three groups: treatment with a fibrin sealant that contained artemin in conjunction with sutures; fibrin sealant with no artemin (sham) in conjunction with sutures; or sutures alone (n=10 in each group). Motor function, sensory function, and autotomy were evaluated from 1 to 12 weeks after injury. Retrograde flourogold tracing 12 weeks after injury showed that the addition of artemin increased the number of regenerating motor neurons. However, it did not improve their performance, as measured by the Sciatic Function Index, compared with sham or suture alone. Animals treated with artemin had a non-significant increase in motor nerve conduction velocity compared with sham. However, artemin did not reverse nerve injury-induced pain behaviour such as cold or heat hypersensitivity. Fibrin sealant in itself did not ameliorate motor performance, or regeneration of motor neurons, or give rise to nerve injury-induced pain behaviour. The results indicate that artemin is of value as a treatment for peripheral nerve injuries, although the effects were limited. As the artemin high-affinity receptor GFRalpha-3 is present in Schwann cells and not in motor neurons, the effect on motor neuron axon regeneration may result from an indirect effect through Schwann cells in the injured nerve.

  13. The Intersection between Ocular and Manual Motor Control: Eye-Hand Coordination in Acquired Brain Injury.

    PubMed

    Rizzo, John-Ross; Hosseini, Maryam; Wong, Eric A; Mackey, Wayne E; Fung, James K; Ahdoot, Edmond; Rucker, Janet C; Raghavan, Preeti; Landy, Michael S; Hudson, Todd E

    2017-01-01

    Acute and chronic disease processes that lead to cerebral injury can often be clinically challenging diagnostically, prognostically, and therapeutically. Neurodegenerative processes are one such elusive diagnostic group, given their often diffuse and indolent nature, creating difficulties in pinpointing specific structural abnormalities that relate to functional limitations. A number of studies in recent years have focused on eye-hand coordination (EHC) in the setting of acquired brain injury (ABI), highlighting the important set of interconnected functions of the eye and hand and their relevance in neurological conditions. These experiments, which have concentrated on focal lesion-based models, have significantly improved our understanding of neurophysiology and underscored the sensitivity of biomarkers in acute and chronic neurological disease processes, especially when such biomarkers are combined synergistically. To better understand EHC and its connection with ABI, there is a need to clarify its definition and to delineate its neuroanatomical and computational underpinnings. Successful EHC relies on the complex feedback- and prediction-mediated relationship between the visual, ocular motor, and manual motor systems and takes advantage of finely orchestrated synergies between these systems in both the spatial and temporal domains. Interactions of this type are representative of functional sensorimotor control, and their disruption constitutes one of the most frequent deficits secondary to brain injury. The present review describes the visually mediated planning and control of eye movements, hand movements, and their coordination, with a particular focus on deficits that occur following neurovascular, neurotraumatic, and neurodegenerative conditions. Following this review, we also discuss potential future research directions, highlighting objective EHC as a sensitive biomarker complement within acute and chronic neurological disease processes.

  14. The Intersection between Ocular and Manual Motor Control: Eye–Hand Coordination in Acquired Brain Injury

    PubMed Central

    Rizzo, John-Ross; Hosseini, Maryam; Wong, Eric A.; Mackey, Wayne E.; Fung, James K.; Ahdoot, Edmond; Rucker, Janet C.; Raghavan, Preeti; Landy, Michael S.; Hudson, Todd E.

    2017-01-01

    Acute and chronic disease processes that lead to cerebral injury can often be clinically challenging diagnostically, prognostically, and therapeutically. Neurodegenerative processes are one such elusive diagnostic group, given their often diffuse and indolent nature, creating difficulties in pinpointing specific structural abnormalities that relate to functional limitations. A number of studies in recent years have focused on eye–hand coordination (EHC) in the setting of acquired brain injury (ABI), highlighting the important set of interconnected functions of the eye and hand and their relevance in neurological conditions. These experiments, which have concentrated on focal lesion-based models, have significantly improved our understanding of neurophysiology and underscored the sensitivity of biomarkers in acute and chronic neurological disease processes, especially when such biomarkers are combined synergistically. To better understand EHC and its connection with ABI, there is a need to clarify its definition and to delineate its neuroanatomical and computational underpinnings. Successful EHC relies on the complex feedback- and prediction-mediated relationship between the visual, ocular motor, and manual motor systems and takes advantage of finely orchestrated synergies between these systems in both the spatial and temporal domains. Interactions of this type are representative of functional sensorimotor control, and their disruption constitutes one of the most frequent deficits secondary to brain injury. The present review describes the visually mediated planning and control of eye movements, hand movements, and their coordination, with a particular focus on deficits that occur following neurovascular, neurotraumatic, and neurodegenerative conditions. Following this review, we also discuss potential future research directions, highlighting objective EHC as a sensitive biomarker complement within acute and chronic neurological disease processes. PMID:28620341

  15. Acute corneal epithelial debridement unmasks the corneal stromal nerve responses to ocular stimulation in rats: Implications for abnormal sensations of the eye.

    PubMed

    Hirata, Harumitsu; Mizerska, Kamila K; Dallacasagrande, Valentina A; Guaiquil, Victor H; Rosenblatt, Mark I

    2017-03-01

    It is widely accepted that the mechanisms for transducing sensory information reside in the nerve terminals. Occasionally, however, studies have appeared demonstrating that similar mechanisms may exist in the axon to which these terminals are connected. We examined this issue using the cornea where nerve terminals in the epithelial cell layers are easily accessible for debridement, leaving the underlying stromal (axonal) nerves undisturbed. In isoflurane-anesthetized rats, we recorded extracellularly from single trigeminal ganglion neurons innervating the cornea that are excited by ocular dryness and cooling: low threshold (<2 oC cooling) and high threshold (>2 oC) cold-sensitive plus dry sensitive (LT-CS+DS and HT-CS+DS) neurons, playing possible roles in tearing and ocular pain. We found that the responses in both types of neurons to dryness, wetness, and menthol stimuli were effectively abolished by the debridement, indicating that their transduction mechanisms lie in the nerve terminals. However, some responses to the cold, heat and hyperosmolar stimuli in LT-CS+DS neurons still remained. Surprisingly, the responses to heat in ~ half of the neurons were augmented after the debridement. We were also able to evoke these residual responses and follow the trajectory of the stromal nerves, which we subsequently confirmed histologically. The residual responses always disappeared when the stromal nerves were cut at the limbus, suggesting that the additional transduction mechanisms for these sensory modalities originated mostly likely in stromal nerves. The functional significance of these residual and enhanced responses from stromal nerves may be related to the abnormal sensations observed in ocular disease.

  16. Ocular motor indicators of executive dysfunction in fragile X and Turner syndromes.

    PubMed

    Lasker, Adrian G; Mazzocco, Michèle M M; Zee, David S

    2007-04-01

    Fragile X and Turner syndromes are two X-chromosome-related disorders associated with executive function and visual spatial deficits. In the present study, we used ocular motor paradigms to examine evidence that disruption to different neurological pathways underlies these deficits. We tested 17 females with fragile X, 19 females with Turner syndrome, and 40 females with neither disorder who comprised the comparison group. Group differences emerged for both the fragile X and Turner syndrome groups, each relative to the comparison group: Females with fragile X had deficits in generating memory-guided saccades, predictive saccades, and saccades made in the overlap condition of a gap/overlap task. Females with Turner syndrome showed deficits in generating memory-guided saccades, but not during either the predictive saccade or gap/overlap task. Females with Turner syndrome, but not females with fragile X, showed deficits in visually guided saccades and anti-saccades. These findings indicate that different brain regions are affected in the two disorders, and suggest that different pathways lead to the similar cognitive phenotypes described for fragile X and Turner syndromes.

  17. Respiratory motor responses to cranial nerve afferent stimulation in rats.

    PubMed

    Hayashi, F; McCrimmon, D R

    1996-10-01

    It was hypothesized that, because rats appear to lack a prominent disynaptic projection from the dorsal respiratory group to phrenic motoneurons (Phr), they would lack the short-latency excitation of Phr output seen in cats in response to stimulation of some cranial nerve afferents. Single-pulse superior laryngeal nerve (SLN) stimulation elicited a short-latency bilateral excitation of glossopharyngeal (IX) and hypoglossal (XII) nerves and an ipsilateral excitation of pharyngeal branch of vagus (PhX) in 67% of rats, but no excitation of Phr. Vagus (X) stimulation elicited a bilateral excitation of Phr and a predominantly ipsilateral excitation of IX and PhX. Single-pulse stimulation of SLN or X also elicited longer-latency, bilateral decreases in activity of all recorded nerves. Repetitive stimulation (50 Hz) of SLN or X suppressed inspiratory activity and prolonged expiration. Lung inflation (7.5 cmH2O) inhibited Phr and PhX activity; X stimulation inhibited Phr but prolonged PhX activity. In conclusion, rats predictably lack the SLN-induced short latency Phr excitation but exhibit other short latency reflexes for which the underlying circuitry is not clear.

  18. Oberlin's ulnar nerve transfer to the biceps motor nerve in obstetric brachial plexus palsy: indications, and good and bad results.

    PubMed

    Noaman, Hassan Hamdy; Shiha, Anis Elsayed; Bahm, Jörg

    2004-01-01

    We present 7 children with obstetric brachial plexus palsy treated by transferring two motor fascicles out of the ulnar nerve to the biceps nerve. Three were male, and 4 were female. The left-side brachial plexus was affected in 4 patients, and the right side in 3 patients. All children had vaginal delivery; two of them presented with shoulder dystocia. The average birth weight was 4300 g (range, 3620-5500 g). Average age at time of operation was 16 months (range, 11-24 months). The indication for the operation was absent active elbow flexion with active shoulder abduction against gravity in 4 cases, and no biceps function and bad shoulder function in 3 cases. Oberlin's ulnar nerve transfer was done in 4 cases without brachial plexus exploration in those children with good shoulder function, and exploration of the brachial plexus was performed in the other 3 cases with bad shoulder function. The average follow-up was 19 months (range, 13-30 months). Five children had biceps muscle >or=M(3) with active elbow flexion against gravity, and 2 children had biceps muscle nerve transfer for upper-type obstetric brachial plexus palsy in 1). breech delivery with avulsion of C5 and C6 nerve roots,) late presentation with good recovery of shoulder function, and 3). neuroma-in-continuity of the upper trunk with intraoperative good nerve conduction for the shoulder muscles, the same as preoperative good shoulder function but with no biceps action. Copyright 2004 Wiley-Liss, Inc.

  19. Interest of Electrostimulation of Peripheral Motor Nerves during Percutaneous Thermal Ablation

    SciTech Connect

    Tsoumakidou, Georgia Garnon, Julien Ramamurthy, Nitin Buy, Xavier Gangi, Afshin

    2013-12-15

    Purpose: We present our experience of utilizing peripheral nerve electrostimulation as a complementary monitoring technique during percutaneous thermal ablation procedures; and we highlight its utility and feasibility in the prevention of iatrogenic neurologic thermal injury. Methods: Peripheral motor nerve electrostimulation was performed in 12 patients undergoing percutaneous image-guided thermal ablations of spinal/pelvic lesions in close proximity to the spinal cord and nerve roots. Electrostimulation was used in addition to existing insulation (active warming/cooling with hydrodissection, passive insulation with CO{sub 2} insufflation) and temperature monitoring (thermocouples) techniques. Impending neurologic deficit was defined as a visual reduction of muscle response or need for a stronger electric current to evoke muscle contraction, compared with baseline. Results: Significant reduction of the muscle response to electrostimulation was observed in three patients during the ablation, necessitating temporary interruption, followed by injection of warm/cool saline. This resulted in complete recovery of the muscle response in two cases, while for the third patient the response did not improve and the procedure was terminated. No patient experienced postoperative motor deficit. Conclusion: Peripheral motor nerve electrostimulation is a simple, easily accessible technique allowing early detection of impending neurologic injury during percutaneous image-guided thermal ablation. It complements existing monitoring techniques and provides a functional assessment along the whole length of the nerve.

  20. Alpha-synuclein pathology and axonal degeneration of the peripheral motor nerves innervating pharyngeal muscles in Parkinson disease.

    PubMed

    Mu, Liancai; Sobotka, Stanislaw; Chen, Jingming; Su, Hungxi; Sanders, Ira; Adler, Charles H; Shill, Holly A; Caviness, John N; Samanta, Johan E; Beach, Thomas G

    2013-02-01

    Parkinson disease (PD) is a neurodegenerative disease primarily characterized by cardinal motor manifestations and CNS pathology. Current drug therapies can often stabilize these cardinal motor symptoms, and attention has shifted to the other motor and nonmotor symptoms of PD that are resistant to drug therapy. Dysphagia in PD is perhaps the most important drug-resistant symptom because it leads to aspiration and pneumonia, the leading cause of death. Here, we present direct evidence for degeneration of the pharyngeal motor nerves in PD. We examined the cervical vagal nerve (cranial nerve X), pharyngeal branch of nerve X, and pharyngeal plexus innervating the pharyngeal muscles in 14 postmortem specimens, that is, from 10 patients with PD and 4 age-matched control subjects. Synucleinopathy in the pharyngeal nerves was detected using an immunohistochemical method for phosphorylated α-synuclein. Alpha-synuclein aggregates were revealed in nerve X and the pharyngeal branch of nerve X, and immunoreactive intramuscular nerve twigs and axon terminals within the neuromuscular junctions were identified in all of the PD patients but in none of the controls. These findings indicate that the motor nervous system of the pharynx is involved in the pathologic process of PD. Notably, PD patients who have had dysphagia had a higher density of α-synuclein aggregates in the pharyngeal nerves than those without dysphagia. These findings indicate that motor involvement of the pharynx in PD is one of the factors leading to oropharyngeal dysphagia commonly seen in PD patients.

  1. A conduction block in sciatic nerves can be detected by magnetic motor root stimulation.

    PubMed

    Matsumoto, Hideyuki; Konoma, Yuko; Fujii, Kengo; Hanajima, Ritsuko; Terao, Yasuo; Ugawa, Yoshikazu

    2013-08-15

    Useful diagnostic techniques for the acute phase of sciatic nerve palsy, an entrapment neuropathy, are not well established. The aim of this paper is to demonstrate the diagnostic utility of magnetic sacral motor root stimulation for sciatic nerve palsy. We analyzed the peripheral nerves innervating the abductor hallucis muscle using both electrical stimulations at the ankle and knee and magnetic stimulations at the neuro-foramina and conus medullaris levels in a patient with sciatic nerve palsy at the level of the piriformis muscle due to gluteal compression related to alcohol consumption. On the fourth day after onset, magnetic sacral motor root stimulation using a MATS coil (the MATS coil stimulation method) clearly revealed a conduction block between the knee and the sacral neuro-foramina. Two weeks after onset, needle electromyography supported the existence of the focal lesion. The MATS coil stimulation method clearly revealed a conduction block in the sciatic nerve and is therefore a useful diagnostic tool for the abnormal neurophysiological findings associated with sciatic nerve palsy even at the acute phase.

  2. Recording sensory and motor information from peripheral nerves with Utah Slanted Electrode Arrays.

    PubMed

    Clark, Gregory A; Ledbetter, Noah M; Warren, David J; Harrison, Reid R

    2011-01-01

    Recording and stimulation via high-count penetrating microelectrode arrays implanted in peripheral nerves may help restore precise motor and sensory function after nervous system damage or disease. Although previous work has demonstrated safety and relatively successful stimulation for long-term implants of 100-electrode Utah Slanted Electrode Arrays (USEAs) in feline sciatic nerve [1], two major remaining challenges were 1) to maintain viable recordings of nerve action potentials long-term, and 2) to overcome contamination of unit recordings by myoelectric (EMG) activity in awake, moving animals. In conjunction with improvements to USEAs themselves, we have redesigned several aspects of our USEA containment and connector systems. Although further increases in unit yield and long-term stability remain desirable, here we report considerable progress toward meeting both of these goals: We have successfully recorded unit activity from USEAs implanted intrafascicularly in sciatic nerve for periods up to 4 months (the terminal experimental time point), and we have developed a containment system that effectively eliminates or substantially reduces EMG contamination of unit recordings in the moving animal. In addition, we used a 100-channel wireless recording integrated circuit attached to implanted USEAs to transmit broadband or spike-threshold data from nerve. Neural data thusly obtained during imposed limb movements were decoded blindly to drive a virtual prosthetic limb in real time. These results support the possibility of using USEAs in peripheral nerves to provide motor control and cutaneous or proprioceptive sensory feedback in individuals after limb loss or spinal cord injury.

  3. Temporary Nerve Block at Selected Digits Revealed Hand Motor Deficits in Grasping Tasks

    PubMed Central

    Carteron, Aude; McPartlan, Kerry; Gioeli, Christina; Reid, Emily; Turturro, Matt; Hahn, Barry; Benson, Cynthia; Zhang, Wei

    2016-01-01

    Peripheral sensory feedback plays a crucial role in ensuring correct motor execution throughout hand grasp control. Previous studies utilized local anesthesia to deprive somatosensory feedback in the digits or hand, observations included sensorimotor deficits at both corticospinal and peripheral levels. However, the questions of how the disturbed and intact sensory input integrate and interact with each other to assist the motor program execution, and whether the motor coordination based on motor output variability between affected and non-affected elements (e.g., digits) becomes interfered by the local sensory deficiency, have not been answered. The current study aims to investigate the effect of peripheral deafferentation through digital nerve blocks at selective digits on motor performance and motor coordination in grasp control. Our results suggested that the absence of somatosensory information induced motor deficits in hand grasp control, as evidenced by reduced maximal force production ability in both local and non-local digits, impairment of force and moment control during object lift and hold, and attenuated motor synergies in stabilizing task performance variables, namely the tangential force and moment of force. These findings implied that individual sensory input is shared across all the digits and the disturbed signal from local sensory channel(s) has a more comprehensive impact on the process of the motor output execution in the sensorimotor integration process. Additionally, a feedback control mechanism with a sensation-based component resides in the formation process for the motor covariation structure. PMID:27932964

  4. Stimulus electrodiagnosis and motor and functional evaluations during ulnar nerve recovery

    PubMed Central

    Fernandes, Luciane F. R. M.; Oliveira, Nuno M. L.; Pelet, Danyelle C. S.; Cunha, Agnes F. S.; Grecco, Marco A. S.; Souza, Luciane A. P. S.

    2016-01-01

    BACKGROUND: Distal ulnar nerve injury leads to impairment of hand function due to motor and sensorial changes. Stimulus electrodiagnosis (SE) is a method of assessing and monitoring the development of this type of injury. OBJECTIVE: To identify the most sensitive electrodiagnostic parameters to evaluate ulnar nerve recovery and to correlate these parameters (Rheobase, Chronaxie, and Accommodation) with motor function evaluations. METHOD: A prospective cohort study of ten patients submitted to ulnar neurorrhaphy and evaluated using electrodiagnosis and motor assessment at two moments of neural recovery. A functional evaluation using the DASH questionnaire (Disability of the Arm, Shoulder, and Hand) was conducted at the end to establish the functional status of the upper limb. RESULTS: There was significant reduction only in the Chronaxie values in relation to time of injury and side (with and without lesion), as well as significant correlation of Chronaxie with the motor domain score. CONCLUSION: Chronaxie was the most sensitive SE parameter for detecting differences in neuromuscular responses during the ulnar nerve recovery process and it was the only parameter correlated with the motor assessment. PMID:26786072

  5. Superficial radial neuropathy and brachioradial motor nerve palsy associated with proximal radius osteochondroma.

    PubMed

    Oz, Oğuzhan; Yücel, Mehmet; Ulaş, Umit; Eroğlu, Erdal; Odabaşi, Zeki

    2010-01-01

    The cutaneous branch of the radial nerve (superficial radial nerve, SRN) might be compressed or injured at various anatomical sites along its course in the forearm. Compression of the SRN occurring at the proximal third of the forearm is unusual. A 22-year-old man was admitted with pain and paraesthesia over the lateral aspect of his right wrist and thumb and pain at the elbow for six months. In electrodiagnostic testing, a sensory nerve action potential from the right SRN could not be recorded, while it was normal on the left. In a needle electromyography study, denervation potentials have been seen in the right brachioradial muscle and a decrease in interference pattern signals was also found. An exophytic lesion of the proximal radius was observed in radiographs. Computed tomography evaluation revealed an osteochondroma of the proximal radius. Neuropathies of the SRN and the brachioradial motor branch of the radial nerve are thought to be associated with proximal radial osteochondroma.

  6. Motor nerve damage is associated with anti-ganglioside antibodies in diabetes.

    PubMed

    Matà, Sabrina; Betti, Elisabetta; Masotti, Giulio; Pinto, Francesco; Lolli, Francesco

    2004-09-01

    Few reports exist on the association between the humoral immune response to glycolipids and neuropathic findings in diabetes. To address this issue, we assayed serum anti-GM1, GD1b, GD1a, and sulfatides IgG and IgM in a group of 85 non-selected diabetic patients, and correlated these antibodies to clinical and electrophysiological findings. Diabetic patients had higher mean titers of anti-GM1 (IgM), GD1b, GD1a, and sulfatide (IgG) antibodies when compared to healthy controls. Patients with a positive titer of anti-ganglioside antibodies had significant alterations of motor conduction parameters. The statistical significance increased when considering those patients with both anti-ganglioside reactivity and a high value for glycosylated hemoglobin. Production of antibodies to ganglioside may follow the exposure of hidden motor nerve epitopes in damaged motor nerves and contribute to the neuropathy.

  7. Coordinated Respiratory Motor Activity in Nerves Innervating the Upper Airway Muscles in Rats

    PubMed Central

    Tachikawa, Satoshi; Nakayama, Kiyomi; Nakamura, Shiro; Mochizuki, Ayako; Iijima, Takehiko; Inoue, Tomio

    2016-01-01

    Maintaining the patency of the upper airway during breathing is of vital importance. The activity of various muscles is related to the patency of the upper airway. In the present study, we examined the respiratory motor activity in the efferent nerves innervating the upper airway muscles to determine the movements of the upper airway during respiration under normocapnic conditions (pH = 7.4) and in hypercapnic acidosis (pH = 7.2). Experiments were performed on arterially perfused decerebrate rats aged between postnatal days 21–35. We recorded the efferent nerve activity in a branch of the cervical spinal nerve innervating the infrahyoid muscles (CN), the hypoglossal nerve (HGN), the external branch of the superior laryngeal nerve (SLN), and the recurrent laryngeal nerve (RLN) with the phrenic nerve (PN). Inspiratory nerve discharges were observed in all these nerves under normocapnic conditions. The onset of inspiratory discharges in the CN and HGN was slightly prior to those in the SLN and RLN. When the CO2 concentration in the perfusate was increased from 5% to 8% to prepare for hypercapnic acidosis, the peak amplitudes of the inspiratory discharges in all the recorded nerves were increased. Moreover, hypercapnic acidosis induced pre-inspiratory discharges in the CN, HGN, SLN, and RLN. The onset of pre-inspiratory discharges in the CN, HGN, and SLN was prior to that of discharges in the RLN. These results suggest that the securing of the airway that occurs a certain time before dilation of the glottis may facilitate ventilation and improve hypercapnic acidosis. PMID:27832132

  8. Coordinated Respiratory Motor Activity in Nerves Innervating the Upper Airway Muscles in Rats.

    PubMed

    Tachikawa, Satoshi; Nakayama, Kiyomi; Nakamura, Shiro; Mochizuki, Ayako; Iijima, Takehiko; Inoue, Tomio

    2016-01-01

    Maintaining the patency of the upper airway during breathing is of vital importance. The activity of various muscles is related to the patency of the upper airway. In the present study, we examined the respiratory motor activity in the efferent nerves innervating the upper airway muscles to determine the movements of the upper airway during respiration under normocapnic conditions (pH = 7.4) and in hypercapnic acidosis (pH = 7.2). Experiments were performed on arterially perfused decerebrate rats aged between postnatal days 21-35. We recorded the efferent nerve activity in a branch of the cervical spinal nerve innervating the infrahyoid muscles (CN), the hypoglossal nerve (HGN), the external branch of the superior laryngeal nerve (SLN), and the recurrent laryngeal nerve (RLN) with the phrenic nerve (PN). Inspiratory nerve discharges were observed in all these nerves under normocapnic conditions. The onset of inspiratory discharges in the CN and HGN was slightly prior to those in the SLN and RLN. When the CO2 concentration in the perfusate was increased from 5% to 8% to prepare for hypercapnic acidosis, the peak amplitudes of the inspiratory discharges in all the recorded nerves were increased. Moreover, hypercapnic acidosis induced pre-inspiratory discharges in the CN, HGN, SLN, and RLN. The onset of pre-inspiratory discharges in the CN, HGN, and SLN was prior to that of discharges in the RLN. These results suggest that the securing of the airway that occurs a certain time before dilation of the glottis may facilitate ventilation and improve hypercapnic acidosis.

  9. Institutional profile: integrated center for research and treatment of vertigo, balance and ocular motor disorders.

    PubMed

    Brandt, Thomas; Zwergal, Andreas; Jahn, Klaus; Strupp, Michael

    2010-01-01

    In 2009 the German BMBF (German Ministry of Education and Research) established an Integrated Center for Research and Treatment (IFB(LMU)) of Vertigo, Balance and Ocular Motor Disorders in Munich. After the 10-year period of funding by the BMBF, it is envisioned that the (IFB(LMU)) will continue over the long term with the joint support of the University Hospital, the Medical Faculty, and the Bavarian State. Vertigo is one of the most common complaints in medicine. Despite its high prevalence, patients with vertigo generally receive either inappropriate or inadequate treatment. This deplorable situation is internationally well known and its causes are multiple: insufficient interdisciplinary cooperation, no standardized diagnostics and therapy, the failure to translate findings of basic science into clinical applications, and the scarcity of clinical multicenter studies. The (IFB(LMU)) will constitute a suitable tool with which these structural, clinical, and scientific deficits can be overcome. It will also make possible the establishment of an international interdisciplinary referral center. Munich has become the site of a unique concentration of leading experts on vertigo, balance and ocular motor disorders, both in the clinical and basic sciences. Academic structures have paved the way for the creation of an interdisciplinary horizontal network that also allows structured, vertical academic career paths via the Bachelor's and Master's degree programs in Neuroscience, a Graduate School of Systemic Neurosciences, and the Munich Center for Neurosciences - Brain and Mind. The (IFB(LMU)) has the following objectives as regards structure and content: to create an independent patient-oriented clinical research center under the auspices of the Medical Faculty but with autonomous administration and budget; to overcome existing clinical and academic barriers separating the traditional specializations; to establish a standardized interdisciplinary longitudinal and

  10. [Integrated Center for Research and Treatment of Vertigo, Balance and Ocular Motor Disorders].

    PubMed

    Brandt, T; Zwergal, A; Jahn, K; Strupp, M

    2009-08-01

    The German BMBF (German Ministry of Education and Research) has decided to establish an Integrated Center for Research and Treatment of Vertigo, Balance and Ocular Motor Disorders (IFB(LMU)) in Munich in 2010. After funding over a 10-year period, the long-term continuation of the IFB(LMU) by the medical faculty and the hospital is envisioned. Vertigo is one of the most common complaints in medicine. Despite its high prevalence patients with vertigo generally receive either inappropriate or inadequate treatment. This deplorable situation is internationally well known and its causes are multiple: insufficient interdisciplinary cooperation, no standardized diagnostics and therapy, the failure to translate findings of basic science into clinical applications and the scarcity of clinical multicenter studies. The IFB(LMU) will constitute a suitable tool with which these structural, clinical, and scientific deficits can be overcome. It will also make possible the establishment of an international interdisciplinary referral center. Munich has become the site of a unique concentration of leading experts on vertigo, balance and ocular motor disorders, both in the clinical and basic sciences. Academic structures have paved the way for the creation of an interdisciplinary horizontal network that also allows structured, vertical academic career paths via the Bachelor's and Master's degree programs in neuroscience, a Graduate School of Systemic Neurosciences, and the Munich Center for Neuroscience "Brain and Mind". The IFB(LMU) has the following objectives with regard to structure and content: to create an independent patient-oriented clinical research center under the auspices of the Medical Faculty but with autonomic administration and budget; to overcome existing clinical and academic barriers separating the traditional specializations, to establish a standardized interdisciplinary longitudinal and transversal network at one site for the management of patients. This should

  11. Ciguatoxin enhances quantal transmitter release from frog motor nerve terminals.

    PubMed Central

    Molgó, J.; Comella, J. X.; Legrand, A. M.

    1990-01-01

    1. Ciguatoxin (CTX), a marine toxin produced by the benthic dinoflagellate Gambierdiscus toxicus, is responsible for a complex endemic disease in man known as ciguatera fish poisoning. In the present study we have investigated the effects of purified CTX extracted for Gymnothorax javanicus moray-eel liver on frog isolated neuromuscular preparations with conventional electrophysiological techniques. 2. CTX (1-2.5 nM) applied to cutaneous pectoris nerve-muscle preparations induced, after a short delay, spontaneous fibrillations of the muscle fibres that could be suppressed with 1 microM tetrodotoxin (TTX) or by formamide to uncouple excitation-contraction. 3. In preparations treated with formamide, CTX (1-2.5 nM) caused either spontaneous or repetitive muscle action potentials (up to frequencies of 60-100 Hz) in response to a single nerve stimulus. Recordings performed at extrajunctional regions of the muscle membrane revealed that during the repetitive firing a prolongation of the repolarizing phase of the action potential occurred. At junctional sites the repetitive action potentials were triggered by repetitive endplate potentials (e.p.ps). 4. CTX (2.5 nM) caused a TTX-sensitive depolarization of the muscle membrane. 5. In junctions equilibrated in solutions containing high Mg2+ + low Ca2+, addition of CTX (1.5 nM) first induced an average increase of 239 +/- 36% in the mean quantal content of e.p.ps. Subsequently CTX reduced and finally blocked nerve-evoked transmitter release irreversibly. 6. CTX (1.5-2.5 nM) increased the frequency of miniature endplate potentials (m.e.p.ps) in junctions bathed either in normal Ringer, low Ca2(+)-high Mg2+ medium or in a nominally Ca2(+)-free solution containing EGTA.2+ Extensive washing with toxin-free solutions did not reverse the effect.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1972891

  12. Ocular motor measures of cognitive dysfunction in multiple sclerosis I: inhibitory control.

    PubMed

    Clough, Meaghan; Millist, Lynette; Lizak, Nathaniel; Beh, Shin; Frohman, Teresa C; Frohman, Elliot M; White, Owen B; Fielding, Joanne

    2015-05-01

    Our ability to control and inhibit behaviours that are inappropriate, unsafe, or no longer required is crucial for functioning successfully in complex environments. Here, we investigated whether a series of ocular motor (OM) inhibition tasks could dissociate deficits in patients with multiple sclerosis (MS), including patients with only a probable diagnosis (clinically isolated syndrome: CIS), from healthy individuals as well as a function of increasing disease duration. 25 patients with CIS, 25 early clinically definite MS patients (CDMS: ≤7 years of diagnosis), 24 late CDMS patients (>7 years from diagnosis), and 25 healthy controls participated. All participants completed a series of classic OM inhibition tasks [antisaccade (AS) task, memory-guided (MG) task, endogenous cue task], and a neuropsychological inhibition task [paced auditory serial addition test (PASAT)]. Clinical disability was characterised in CDMS patients using the Expanded Disability Severity Scale (EDSS). OM (latency and error) and PASAT performance were compared between patient groups and controls, as well as a function of disease duration. For CDMS patients only, results were correlated with EDSS score. All patient groups made more errors than controls on all OM tasks; error rate did not increase with increasing disease duration. In contrast, saccade latency (MG and endogenous cue tasks) was found to worsen with increasing disease duration. PASAT performance did not discriminate patient groups or disease duration. The EDSS did not correlate with any measure. These OM measures appear to dissociate deficit between patients at different disease durations. This suggests their utility as a measure of progression from the earliest inception of the disease.

  13. Neurotransmitter release evoked by nerve impulses without Ca2+ entry through Ca2+ channels in frog motor nerve endings.

    PubMed Central

    Silinsky, E M; Watanabe, M; Redman, R S; Qiu, R; Hirsh, J K; Hunt, J M; Solsona, C S; Alford, S; MacDonald, R C

    1995-01-01

    1. The requirement for extracellular Ca2+ in the process of evoked acetylcholine (ACh) release by nerve impulses was tested at endplates in frog skeletal muscle. Ca(2+)-containing lipid vesicles (Ca2+ liposomes) were used to elevate cytoplasmic Ca2+ concentrations under conditions in which Ca2+ entry from the extracellular fluid was prevented. 2. In an extracellular solution containing no added Ca2+ and 1 mM Mg2+ ('Ca(2+)-free' solution), Ca2+ liposomes promoted the synchronous release of ACh quanta, reflected electrophysiologically as endplate potentials (EPPs), in response to temporally isolated nerve impulses. 3. Motor nerve stimulation generated EPPs during superfusion with Ca2+ liposomes in Ca(2+)-free solutions containing the Ca2+ channel blocker Co2+ (1 mM), and the Ca2+ chelator EGTA (2 mM). As a physiological control for Ca2+ leakage from the liposomes to the extracellular fluid, the effect of Ca2+ liposomes on asynchronous evoked ACh release mediated by Ba2+ was examined. In contrast to the effects of 0.2-0.3 mM extracellular Ca2+, which generated EPPs but antagonized Ba(2+)-mediated asynchronous ACh release, Ca2+ liposomes generated EPPs but did not reduce asynchronous release mediated by Ba2+. The effects of Ca2+ liposomes were thus not due to leakage of Ca2+ from the liposome to the extracellular fluid. 4. Morphological studies using fluorescently labelled liposomes in conjunction with a confocal microscope demonstrate that lipid is transferred from the liposomes to nerve endings and liposomal contents are delivered to the nerve terminal cytoplasm. 5. The results suggest that when intracellular Ca2+ is elevated using liposomes as a vehicle, evoked ACh release can occur in the absence of Ca2+ entry via Ca2+ channels. Images Figure 5 Figure 6 PMID:7738845

  14. α-Synuclein Pathology and Axonal Degeneration of the Peripheral Motor Nerves Innervating Pharyngeal Muscles in Parkinson’s Disease

    PubMed Central

    Mu, Liancai; Sobotka, Stanislaw; Chen, Jingming; Su, Hungxi; Sanders, Ira; Adler, Charles H.; Shill, Holly A.; Caviness, John N.; Samanta, Johan E.; Beach, Thomas G.

    2012-01-01

    Parkinson’s disease (PD) is a neurodegenerative disease primarily characterized by cardinal motor symptoms and central nervous system pathology. As current drug therapies can often stabilize these cardinal motor symptoms attention has shifted to the other motor and non-motor symptoms of PD which are resistant to drug therapy. Dysphagia in PD is perhaps the most important drug resistant symptom as it leads to aspiration and pneumonia, the leading cause of death. Here, we present direct evidence for degeneration of the pharyngeal motor nerves in PD. In this study, we examined the cervical vagal (X) nerve, pharyngeal branch of the X nerve (Ph-X), and pharyngeal plexus innervating the pharyngeal muscles in 14 postmortem specimens, 10 subjects with PD and 4 age-matched control subjects. Synucleinopathy in the pharyngeal nerves was detected using an immunohistochemical method for phosphorylated α-synuclein. α-Synuclein aggregates were revealed in the X nerve and Ph-X and immunoreactive intramuscular nerve twigs and axon terminals within the neuromuscular junctions were identified in all the PD subjects and in none of the controls. These findings indicate that the motor nervous system of the pharynx is involved in the pathological process of PD. Notably, PD subjects with dysphagia had a higher density of α-synuclein aggregates in the pharyngeal nerves as compared with those without dysphagia. Motor involvement of the pharynx in PD appears to be one of the factors leading to oropharyngeal dysphagia commonly seen in PD patients. PMID:23334595

  15. Use of the masseter motor nerve in facial animation with free muscle transfer.

    PubMed

    Bianchi, Bernardo; Copelli, Chiara; Ferrari, Silvano; Ferri, Andrea; Sesenna, Enrico

    2012-10-01

    Facial paralysis is either congenital or acquired, and of varying severity, which leads to an asymmetrical or absent facial expression. It is an important disability both from the aesthetic and functional points of view. Between 2003 and 2008, at the Department of Maxillofacial Surgery, University of Parma, Italy, 21 patients with facial paralysis had their faces reanimated with a gracilis transplant reinnervated by the masseter motor nerve. All free-muscle transplants survived the transfer, and no flap was lost. Facial symmetry at rest and while smiling was excellent or good in most cases, and we found an appreciable improvement in both speech and oral competence. We consider that the masseter motor nerve is a powerful and reliable donor nerve, which allows us to obtain movement of the commissure and upper lip similar to those of the normal site for degree and direction. There may be a role for the masseter motor nerve in innervation of patients with facial paralysis. Copyright © 2011 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  16. ECEL1 mutation implicates impaired axonal arborization of motor nerves in the pathogenesis of distal arthrogryposis.

    PubMed

    Nagata, Kenichi; Kiryu-Seo, Sumiko; Tamada, Hiromi; Okuyama-Uchimura, Fumi; Kiyama, Hiroshi; Saido, Takaomi C

    2016-07-01

    The membrane-bound metalloprotease endothelin-converting enzyme-like 1 (ECEL1) has been newly identified as a causal gene of a specific type of distal arthrogryposis (DA). In contrast to most causal genes of DA, ECEL1 is predominantly expressed in neuronal cells, suggesting a unique neurogenic pathogenesis in a subset of DA patients with ECEL1 mutation. The present study analyzed developmental motor innervation and neuromuscular junction formation in limbs of the rodent homologue damage-induced neuronal endopeptidase (DINE)-deficient mouse. Whole-mount immunostaining was performed in DINE-deficient limbs expressing motoneuron-specific GFP to visualize motor innervation throughout the limb. Although DINE-deficient motor nerves displayed normal trajectory patterns from the spinal cord to skeletal muscles, they indicated impaired axonal arborization in skeletal muscles in the forelimbs and hindlimbs. Systematic examination of motor innervation in over 10 different hindlimb muscles provided evidence that DINE gene disruption leads to insufficient arborization of motor nerves after arriving at the skeletal muscle. Interestingly, the axonal arborization defect in foot muscles appeared more severe than in other hindlimb muscles, which was partially consistent with the proximal-distal phenotypic discordance observed in DA patients. Additionally, the number of innervated neuromuscular junction was significantly reduced in the severely affected DINE-deficient muscle. Furthermore, we generated a DINE knock-in (KI) mouse model with a pathogenic mutation, which was recently identified in DA patients. Axonal arborization defects were clearly detected in motor nerves of the DINE KI limb, which was identical to the DINE-deficient limb. Given that the encoded sequences, as well as ECEL1 and DINE expression profiles, are highly conserved between mouse and human, abnormal arborization of motor axons and subsequent failure of NMJ formation could be a primary cause of DA with ECEL1

  17. Long-Standing Motor and Sensory Recovery following Acute Fibrin Sealant Based Neonatal Sciatic Nerve Repair

    PubMed Central

    Ferreira Junior, Rui Seabra

    2016-01-01

    Brachial plexus lesion results in loss of motor and sensory function, being more harmful in the neonate. Therefore, this study evaluated neuroprotection and regeneration after neonatal peripheral nerve coaptation with fibrin sealant. Thus, P2 neonatal Lewis rats were divided into three groups: AX: sciatic nerve axotomy (SNA) without treatment; AX+FS: SNA followed by end-to-end coaptation with fibrin sealant derived from snake venom; AX+CFS: SNA followed by end-to-end coaptation with commercial fibrin sealant. Results were analyzed 4, 8, and 12 weeks after lesion. Astrogliosis, microglial reaction, and synapse preservation were evaluated by immunohistochemistry. Neuronal survival, axonal regeneration, and ultrastructural changes at ventral spinal cord were also investigated. Sensory-motor recovery was behaviorally studied. Coaptation preserved synaptic covering on lesioned motoneurons and led to neuronal survival. Reactive gliosis and microglial reaction decreased in the same groups (AX+FS, AX+CFS) at 4 weeks. Regarding axonal regeneration, coaptation allowed recovery of greater number of myelinated fibers, with improved morphometric parameters. Preservation of inhibitory synaptic terminals was accompanied by significant improvement in the motor as well as in the nociceptive recovery. Overall, the present data suggest that acute repair of neonatal peripheral nerves with fibrin sealant results in neuroprotection and regeneration of motor and sensory axons. PMID:27446617

  18. Reliability of a digital electroneurometer for the determination of motor latency of the median nerve.

    PubMed

    Cook, T M; Rosecrance, J C; Brokman, S J; Rulon, A S; Wise, C A

    1991-06-01

    Measurement of distal motor latencies of the median nerve are often part of electrodiagnostic studies used to verify a diagnosis of peripheral neuropathy. Since electrodiagnostic studies are time consuming, expensive, and impractical for large-scale screening of at-risk individuals, a portable digital electroneurometer was developed for measuring motor latencies as a screening tool for early detection of nerve compression syndromes, including carpal tunnel syndrome. The purpose of this study was to determine the intertester and intratester reliability of a digital electroneurometer in subjects with (n=12) and without (n=20) clinical signs of carpal tunnel syndrome. This study addressed only the reliability and not the validity of this device. Using a repeated measures design, three evaluators performed two distal motor latency tests on the median nerve of each of the subjects. Pearson product-moment correlations for intratester reliability ranged from 0.94 to 0.99, and the intraclass correlation coefficient for intertester reliability was 0.96. Two examiners obtained statistically larger latency values on the second test, although these differences are judged to be clinically insignificant. Use of an electroneurometer may expand motor latency testing to a wider variety of settings.

  19. Evaluation of the motor and sensory components of the pudendal nerve.

    PubMed

    Loening-Baucke, V; Read, N W; Yamada, T; Barker, A T

    1994-02-01

    Extensive neurophysiological investigations consisting of different techniques to evaluate the efferents and afferents of the pudendal nerve were carried out in 27 healthy subjects. These investigations included motor evoked potential recordings from the external anal sphincter in response to magnetic stimulation of the cortex and lumbosacral roots, measurement of sacral reflex latency to magnetic and electrical stimulation, and cortical sensory evoked potential recording after stimulation of the dorso-genital nerve and anal canal. Motor latencies after transcranial magnetic stimulation to the anal sphincter were 25.1 +/- 2.9 msec at rest and 20.9 +/- 2.0 msec with voluntary sphincter contraction (facilitation). Motor latency after lumbosacral root stimulation was 3.7 +/- 1.0 msec. Mean sacral reflex latency after magnetic stimulation was 43.8 +/- 11.2 msec and was significantly longer than after electrical stimulation (37.0 +/- 7.2 msec; P < 0.05). P1 latency of the sensory evoked potentials after dorso-genital nerve stimulation was 40 +/- 3 msec and was significantly shorter than after anal stimulation 46 +/- 3 msec (P < 0.01). Evoked potential recording allows us to study both upper and lower motor neuron components to the anal sphincter. The present study paves the way for the combined application of these tests in the evaluation of disorders of the pelvic floor.

  20. Upslope treadmill exercise enhances motor axon regeneration but not functional recovery following peripheral nerve injury

    PubMed Central

    Cannoy, Jill; Crowley, Sam; Jarratt, Allen; Werts, Kelly LeFevere; Osborne, Krista; Park, Sohee

    2016-01-01

    Following peripheral nerve injury, moderate daily exercise conducted on a level treadmill results in enhanced axon regeneration and modest improvements in functional recovery. If the exercise is conducted on an upwardly inclined treadmill, even more motor axons regenerate successfully and reinnervate muscle targets. Whether this increased motor axon regeneration also results in greater improvement in functional recovery from sciatic nerve injury was studied. Axon regeneration and muscle reinnervation were studied in Lewis rats over an 11 wk postinjury period using stimulus evoked electromyographic (EMG) responses in the soleus muscle of awake animals. Motor axon regeneration and muscle reinnervation were enhanced in slope-trained rats. Direct muscle (M) responses reappeared faster in slope-trained animals than in other groups and ultimately were larger than untreated animals. The amplitude of monosynaptic H reflexes recorded from slope-trained rats remained significantly smaller than all other groups of animals for the duration of the study. The restoration of the amplitude and pattern of locomotor EMG activity in soleus and tibialis anterior and of hindblimb kinematics was studied during treadmill walking on different slopes. Slope-trained rats did not recover the ability to modulate the intensity of locomotor EMG activity with slope. Patterned EMG activity in flexor and extensor muscles was not noted in slope-trained rats. Neither hindblimb length nor limb orientation during level, upslope, or downslope walking was restored in slope-trained rats. Slope training enhanced motor axon regeneration but did not improve functional recovery following sciatic nerve transection and repair. PMID:27466130

  1. Management of acute cranial nerve 3, 4 and 6 palsies: role of neuroimaging.

    PubMed

    Tamhankar, Madhura A; Volpe, Nicholas J

    2015-11-01

    This article will discuss the management of isolated, acute cranial nerve 3,4 and 6 palsies with special focus on the role of neuroimaging in older adults based on recently published data. Acute cranial nerve palsies affecting the third, fourth or sixth cranial nerves in isolation or in combination with other neurological signs and symptoms can be due to a variety of causes such as ischemia, inflammation, infection and compression of the ocular motor nerves. Although neuroimaging is generally recommended in all individuals presenting with ocular motor nerve palsies that occur in association with other neurological signs and symptoms, the indications for neuroimaging in older individuals (age > 50 years) who present with acute isolated ocular motor nerve palsies are less clear and controversial. Past and recent studies have attempted to address this question. A recent prospective study found that overall 16.5% of adult patients presenting with acute ocular motor mononeuropathy had structural lesions on MRI scan and 4.6% with fourth and sixth nerve palsies and no risk factors were found to have positive MRI scans. On the basis of recently published data, we recommend contrast-enhanced MRI for all patients presenting with acute, isolated ocular motor mononeuropathies irrespective of age. Studies have clearly shown a small but significant prevalence of important findings in this group of patients thus favoring neuroimaging at the time of diagnosis.

  2. Direct motor evoked potentials and cortical mapping using the NIM® nerve monitoring system: A technical note.

    PubMed

    Bharadwaj, Suparna; Haji, Faizal; Hebb, Matthew; Chui, Jason

    2017-04-01

    Motor evoked potentials (MEPs) are commonly used to prevent neurological injury when operating in close proximity to the motor cortex or corticospinal pathway. We report a novel application of the NIM® nerve monitoring system (Medtronic@ NIM response 3.0) for intraoperative direct cortical (dc)-MEPs monitoring. A 69-year-old female patient presented with a 4month history of progressive left hemiparesis resulting from a large right sided posterior frontal meningioma that abutted and compressed the motor cortex. Motor cortical mapping and MEPs were indicated. The patient was anesthetized and maintained on total intravenous anesthetics. Compound muscle action potentials (CMAP) of the right upper limb were monitored using the NIM system. After a craniotomy was performed, we first used the Ojemann stimulator (monopolar) for dc-stimulation and then switched to use the monopolar nerve stimulator probe of the NIM system. The CMAP response was successfully elicited using the NIM stimulating probe (pulse width=250s, train frequency=7pulses/s, current=20mA). A gross total resection of the tumor was achieved with intermittent cortical mapping of MEPs. There were no intraoperative complications and the patient's motor function was preserved after the surgery. In this case, we reported the successful use of the NIM nerve monitoring system to elicit dc-MEPs under general anesthesia. The advantages of using this system include a simple set up and application, neurosurgeon familiarity, wide availability and lower cost. dc-MEPs can be achieved using the NIM system. We conclude that the NIM nerve monitoring system is a feasible alternative to standard neurophysiological monitoring systems.

  3. Early motor neuron pool identity and muscle nerve trajectory defined by postmitotic restrictions in Nkx6.1 activity.

    PubMed

    De Marco Garcia, Natalia V; Jessell, Thomas M

    2008-01-24

    The fidelity with which spinal motor neurons innervate their limb target muscles helps to coordinate motor behavior, but the mechanisms that determine precise patterns of nerve-muscle connectivity remain obscure. We show that Nkx6 proteins, a set of Hox-regulated homeodomain transcription factors, are expressed by motor pools soon after motor neurons leave the cell cycle, before the formation of muscle nerve side branches in the limb. Using mouse genetics, we show that the status of Nkx6.1 expression in certain motor neuron pools regulates muscle nerve formation, and the pattern of innervation of individual muscles. Our findings provide genetic evidence that neurons within motor pools possess an early transcriptional identity that controls target muscle specificity.

  4. Analysis of motor fibers in the communicating branch between the cervical nerves and the spinal accessory nerve to innervate trapezius in the rat.

    PubMed

    Yan, Jun; Hitomi, Jiro

    2006-11-01

    The communicating branch between the ventral rami of cervical nerves and the spinal accessory nerve (SAN) has been reported to also send motor fibers to supply the trapezius. However, the motor fiber type of the communicating branch and its peripheral distribution are still unclear. To determine the fiber elements within the branch and its peripheral distribution of the motor fibers in the trapezius, the anterograde tracing method was used in this study. The results show that a few a motor end plates from the communicating branch were observed on the extrafusal fibers, while in the muscle spindle the motor elements from the communicating branch were distributed to the polar portions of the intrafusal fibers. These results indicated that the motor fibers passing through the communicating branch to supply the trapezius are mainly y motor fibers, with some a motor fibers. Moreover, the a and y motor fibers from the communicating branch were observed in the clavotrapezius, acromiotrapezius and the rostral part of spinotrapezius. These findings also correlate with the clinical observation indicating that even when the spinal accessory nerve is injured, the trapezius is still capable of slight movement.

  5. Vascular and neuronal protection induced by the ocular administration of nerve growth factor in diabetic-induced rat encephalopathy.

    PubMed

    Tirassa, Paola; Maccarone, Mattia; Florenzano, Fulvio; Cartolano, Sara; De Nicolò, Sara

    2013-05-01

    Based on our previous findings on the efficacy of ocular applied nerve growth factor as eye drops (oNGF) to act in brain and counteract neuronal damage, we hypothesized that oNGF treatment might revert neuronal atrophy occurring in diabetic brain also by controlling neurotrophin system changes. The major NGF brain target areas, such as the septum and the hippocampus, were used as an experimental paradigma to test this hypothesis. Bilateral oNGF treatment was performed twice a day for 2 weeks in full-blown streptozotocin-treated adult male rats. The forebrain distribution of cholinergic and endothelial cell markers and NGF receptors were studied by confocal microscopy. The septo-hippocampal content of NGF mature and precursor form and NGF receptors expression were also analyzed by Elisa and Western blot. oNGF treatment recovers the morphological alterations and the neuronal atrophy in septum and normalized the expression of mature and pro-NGF, as well as NGF receptors in the septum and hippocampus of diabetic rats. In addition, oNGF stimulated brain vascularization and up-regulated the TRKA receptor in vessel endothelium. Our findings confirm that reduced availability of mature NGF and NGF signaling impairment favors vascular and neuronal alterations in diabetic septo-hippocampal areas and corroborate the ability of oNGF to act as a neuroprotective agent in brain. © 2013 Blackwell Publishing Ltd.

  6. Nerve growth factor antibody stimulates reactivation of ocular herpes simplex virus type 1 in latently infected rabbits.

    PubMed

    Hill, J M; Garza, H H; Helmy, M F; Cook, S D; Osborne, P A; Johnson, E M; Thompson, H W; Green, L C; O'Callaghan, R J; Gebhardt, B M

    1997-06-01

    Anti-nerve growth factor (anti-NGF) antibody has been shown to induce reactivation of latent herpes simplex virus type 1 (HSV-1) in vitro. We found that systemically administered anti-NGF induces ocular shedding of HSV-1 in vivo in rabbits harboring latent virus. Rabbits in which HSV-1 latency had been established were given intravenous injections of goat anti-NGF serum daily for 10 days beginning 42 days after primary viral infection. Tears were assayed for virus for 12 days beginning on the day of the first injection. All eight rabbits given high titer anti-NGF had infectious virus in their tears at least once during the 12-day period. Fifteen of 16 eyes were positive and the average duration of viral shedding for these eyes was 4.0 days. Latently infected rabbits receiving daily injections of nonimmune goat serum or saline for 10 consecutive days were controls. Only six of the 16 (38%) eyes from rabbits receiving nonimmune goat serum shed virus. Only one of 12 eyes from untreated rabbits shed virus. Sera from control rabbits had no detectable anti-NGF activity; titers in anti-NGF-treated rabbits ranged between 1:1000 and 1:10,000. NGF deprivation may act as a neuronal stressor and may share a common second messenger pathway with heat- or cold-stress induced reactivation of latent HSV-1.

  7. Structure/Function assessment of synapses at motor nerve terminals

    PubMed Central

    Johnstone, A. F. M.; Viele, K.; Cooper, R. L.

    2010-01-01

    The release of transmitter at neuromuscular junctions (NMJ) of the opener muscle in crayfish is quantal in nature. This NMJ offers the advantage of being able to record quantal events at specific visually identified release sites, thus allowing measurement of the physiological parameters of vesicle release and its response to be directly correlated with synaptic structure. These experiments take advantage of areas between the varicosities on the nerve terminal that we define as “stems”. Stems were chosen as the region to study because of their low synaptic output due to fewer synaptic sites. Through 3-D reconstruction from hundreds of serial sections, obtained by transmission electron microscopy (TEM), at a site in which focal macropatch recordings were obtained, the number of synapses and AZs are revealed. Thus, physiological profiles with various stimulation conditions can be assessed in regards to direct synaptic structure. Here we used the properties of the quantal shape to determine if distinct subsets of quantal signatures existed and if differences in the distributions are present depending on the frequency of stimulation. Such a quantal signature could come about by parameters of area, rise time, peak amplitude, latency and tau decay. In this study, it is shown that even at defined sites on the stem, with few active zones, synaptic transmission is still complex and the quantal responses appear to be variable even for a given synapse over time. In this study we could not identify a quantal signature for the conditions utilized. PMID:20730805

  8. Structure/function assessment of synapses at motor nerve terminals.

    PubMed

    Johnstone, A F M; Viele, K; Cooper, R L

    2011-04-01

    The release of transmitter at neuromuscular junctions (NMJ) of the opener muscle in crayfish is quantal in nature. This NMJ offers the advantage of being able to record quantal events at specific visually identified release sites, thus allowing measurement of the physiological parameters of vesicle release and its response to be directly correlated with synaptic structure. These experiments take advantage of areas between the varicosities on the nerve terminal that we define as "stems." Stems were chosen as the region to study because of their low synaptic output due to fewer synaptic sites. Through 3D reconstruction from hundreds of serial sections, obtained by transmission electron microscopy (TEM), at a site in which focal macropatch recordings were obtained, the number of synapses and AZs are revealed. Thus, physiological profiles with various stimulation conditions can be assessed in regards to direct synaptic structure. Here, we used the properties of the quantal shape to determine if distinct subsets of quantal signatures existed and if differences in the distributions are present depending on the frequency of stimulation. Such a quantal signature could come about by parameters of area, rise time, peak amplitude, latency, and tau decay. In this study, it is shown that even at defined sites on the stem, with few active zones, synaptic transmission is still complex and the quantal responses appear to be variable even for a given synapse over time. In this study, we could not identify a quantal signature for the conditions utilized. Copyright © 2010 Wiley-Liss, Inc.

  9. Nerve ultrasound as follow-up tool in treated multifocal motor neuropathy.

    PubMed

    Rattay, T W; Winter, N; Décard, B F; Dammeier, N M; Härtig, F; Ceanga, M; Axer, H; Grimm, A

    2017-09-01

    High-resolution ultrasound is a valuable tool in supporting the diagnosis of multifocal motor neuropathy (MMN) but longitudinal data under therapy are lacking. The change in peripheral nerve ultrasound pattern in patients with MMN was assessed over time. Patients with MMN received a thorough initial examination and follow-up over a period of 6-12 months using high-resolution ultrasound of the cervical roots and the nerves of the arms and legs, nerve conduction studies, Medical Research Council Sum Score (MRCSS) and Rotterdam Inflammatory Neuropathy Cause and Treatment Group (INCAT) score to evaluate changes under treatment. The Ultrasound Pattern Sum Score (UPSS) was used as standardized peripheral nerve ultrasound protocol. Seventeen patients with MMN received initial examinations of whom 12 were successfully followed up. All patients with MMN showed at least localized but often multifocal peripheral nerve enlargement. An enlarged overall cross-sectional area as well as enlarged single fascicles (>3 mm²) in clinically and electrophysiologically affected (>90%) and unaffected (>70%) nerves were found. The UPSS did not correlate with clinical disability at both visits. However, the change in clinical disability (evaluated as difference in MRCSS) and the change in UPSS correlated significantly inversely (P = 0.004). High-resolution sonography of peripheral nerves revealed multifocal nerve enlargement in MMN. Distinct enlargement patterns may support the diagnosis. Ultrasound findings did not correlate well with clinical severity or electrophysiological findings at initial presentation. As changes in UPSS correlated significantly with the clinical course in terms of muscle strength (MRCSS), sonographic assessment may represent a useful tool for therapeutic monitoring. © 2017 EAN.

  10. Optic Nerve Sheath as a Novel Mechanical Load on the Globe in Ocular Duction

    PubMed Central

    Demer, Joseph L.

    2016-01-01

    Purpose The optic nerve (ON) sheath's role in limiting duction has been previously unappreciated. This study employed magnetic resonance imaging (MRI) to demonstrate this constraint on adduction. Methods High-resolution, surface coil axial MRI was obtained in 11 normal adults, 14 subjects with esotropia (ET) having normal axial length (AL) < 25.8 mm, 13 myopic subjects with ET and mean AL 29.3 ± 3.3 (SD) mm, and 7 subjects with exotropia (XT). Gaze angles and ON lengths were measured for scans employing eccentric lateral fixation in which an ON became completely straightened. Results In all groups, ON straightening occurred only in the adducting, not abducting, eye. Adduction at ON straightening was 26.0 ± 8.8° in normal subjects, not significantly different from XT at 22.2 ± 11.8°. However, there was significant increase in comparable adduction in ET to 36.3 ± 9.3°, and in myopic ET to 33.6 ± 10.7° (P < 0.04). Optic nerve length at straightening was 27.6 ± 2.7 mm in normals, not significantly different from 28.2 ± 2.8 mm in ET and 27.8 ± 2.7 mm in XT. In myopic ET, ON length at straightening was significantly reduced to 24.0 ± 2.9 mm (P < 0.002) and was associated with globe retraction in adduction, suggesting ON tethering. Conclusions Large adduction may exhaust length redundancy in the normally sinuous ON and sheath, so that additional adduction must stretch the sheath and retract or deform the globe. These mechanical effects are most significant in ET with axial myopia, but may also exert traction on the posterior sclera absent strabismus or myopia. Tethering by the ON sheath in adduction is an important, novel mechanical load on the globe. PMID:27082297

  11. The degree of facial movement following microvascular muscle transfer in pediatric facial reanimation depends on donor motor nerve axonal density.

    PubMed

    Snyder-Warwick, Alison K; Fattah, Adel Y; Zive, Leanne; Halliday, William; Borschel, Gregory H; Zuker, Ronald M

    2015-02-01

    Free functional muscle transfer to the face is a standard of facial animation. The contralateral facial nerve, via a cross-face nerve graft, provides spontaneous innervation for the transferred muscle, but is not universally available and has additional shortcomings. The motor nerve to the masseter provides an alternative innervation source. In this study, the authors compared donor nerve histomorphometry and clinical outcomes in a single patient population undergoing free muscle transfer to the face. Pediatric patients undergoing dynamic facial (re-)animation with intraoperative nerve biopsies and gracilis transfer to the face powered by either the contralateral facial nerve via a cross-face nerve graft or the motor nerve to the masseter were reviewed over a 7-year period. Myelinated nerve counts were assessed histomorphometrically, and functional outcomes were evaluated with the Scaled Measurement of Improvement in Lip Excursion software. From 2004 to 2011, 91 facial (re-)animation procedures satisfied study inclusion criteria. Average myelinated fiber counts were 6757 per mm2 in the donor facial nerve branch, 1647 per mm in the downstream cross-face nerve graft at the second stage, and 5289 per mm in the masseteric nerve. Reconstructions with either innervation source resulted in improvements in oral commissure excursion and smile symmetry, with the greatest amounts of oral commissure excursion noted in the masseteric nerve group. Facial (re-)animation procedures with use of the cross-face nerve graft or masseteric nerve are effective and result in symmetric smiles. The masseteric nerve provides a more robust innervation source and results in greater commissure excursion. Therapeutic, III.

  12. Intercostal nerve transfer to the biceps motor branch in complete traumatic brachial plexus injuries.

    PubMed

    Cho, Alvaro Baik; Iamaguchi, Raquel Bernardelli; Silva, Gustavo Bersani; Paulos, Renata Gregorio; Kiyohara, Leandro Yoshinobu; Sorrenti, Luiz; de Menezes, Klícia de Oliveira Costa Riker Teles; de Rezende, Marcelo Rosa; Wei, Teng Hsiang; Mattar Júnior, Rames

    2015-09-01

    The purpose of this report is to critically evaluate our results of two intercostal nerve transfers directly to the biceps motor branch in complete traumatic brachial plexus injuries. From January 2007 to November 2012, 19 patients were submitted to this type of surgery, but only 15 of them had a follow-up for ≥2 years and were included in this report. The mean interval from trauma to surgery was 6.88 months (ranging from 3 to 9 months). Two intercostals nerves were dissected and transferred directly to the biceps motor branch. The mean follow-up was 38.06 months (ranging from 24 to 62 months). Ten patients (66.6%) recovered an elbow flexion strength ≥M3. Four of them (26.66%) recovered a stronger elbow flexion ≥M4. One patient (6.25%) recovered an M2 elbow flexion and four patients (26.66%) did not regain any movement. We concluded that two intercostal nerve transfers to the biceps motor branch is a procedure with moderate results regarding elbow flexion recovery, but it is still one of the few options available in complete brachial plexus injuries, especially in five roots avulsion scenario. © 2015 Wiley Periodicals, Inc.

  13. Effects of Latrodectus spider venoms on sensory and motor nerve terminals of muscle spindles.

    PubMed

    Queiroz, L S; Duchen, L W

    1982-08-23

    The effects of the venoms of the spiders Latrodectus mactans tredecimguttatus (black widow) and Latrodectus mactans hasselti (red back) on sensory nerve terminals in muscle spindles were studied in the mouse. A sublethal dose of venom was injected into tibialis anterior and extensor digitorum longus muscles of one leg. After survival from 30 minutes to 6 weeks muscles were examined in serial paraffin sections impregnated with silver or by electron microscopy. Sensory endings became swollen, some within 30 minutes, while over the next few hours there was progressive degeneration of annulospiral endings. By 24 hours every spindle identified by light or electron microscopy was devoid of sensory terminals. Degenerated nerve endings were taken up into the sarcoplasm of intrafusal muscle fibres. Regeneration of sensory axons began within 24 hours, new incomplete spirals were formed by 5 days and by 1 week annulospiral endings were almost all normal in appearance. Intrafusal motor terminals underwent similar acute degenerative and regenerative changes. These experiments show that intrafusal sensory and motor terminals are equally affected by Latrodectus venoms. Sensory nerve fibres possess a capacity for regeneration equal to that of motor fibres and reinnervate intrafusal muscle fibres close to their original sites of innervation.

  14. The effect of visual therapy on the ocular motor control of seven- to eight-year-old children with developmental coordination disorder (DCD).

    PubMed

    Coetzee, Dané; Pienaar, Anita E

    2013-11-01

    The aims of this study were to determine the extent of ocular, motor control problems and the effect of visual therapy on such problems, among seven- to eight-year-old children diagnosed with DCD. Thirty-two, children with a mean age of 95.66 months (SD ± 3.54) participated in the study. The MABC was used to classify children into DCD categories (<15th, percentile) while the Sensory Input Systems Screening Test and QNST-II, were used to evaluate ocular motor control. A two-group pre-test-post-test, cross-over design was followed with a retention test two years, thereafter to determine the lasting effect of the visual therapy, intervention. The 18-week visual therapy programme was executed once a week, for 40 min during school hours, after which the two groups were, crossed over. Percentages of ocular motor control problems ranging, between 6.25% and 93.75% were found in both the groups before participating, in the visual therapy programme, with the highest percentage problems found, in visual pursuit with the left eye. Visual therapy contributed to a, significant improvement of 75-100% in visual pursuit, fixation, ocular, alignment and convergence, with significant lasting effects (p<0.001). Visual therapy is recommended for children with DCD experiencing poor, ocular motor control. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Central connections of the sensory and motor nuclei of the vagus nerve.

    PubMed

    Sawchenko, P E

    1983-10-01

    Recent morphological and immunohistochemical studies bearing on the central pathways involved in processing vagal afferent information and in modulating the activity of vagal preganglionic neurons are summarized. The nucleus of the solitary tract (NTS), the principal recipient of first order vagal afferent inputs, projects to preganglionic cell groups of both divisions of the autonomic nervous system, to motor nuclei of cranial nerves that supply the face and tongue, to a series of 'relay' nuclei in the brainstem, and to a number of cell groups in the hypothalamus and the limbic region of the telencephalon that integrate autonomic, neuroendocrine and regulatory behavioral responses. With the exception of the cranial nerve motor nuclei, each cell group in receipt of direct inputs from the NTS projects back to this region and/or to the vagal motor nuclei, and is thereby in a position to influence vagal motor outflow. This central vagal system is further characterized by the presence of neurons that contain an impressive diversity of neuropeptides and monoamines. Examples are cited to illustrate how biochemically specified projections within this system are organized, and how they provide potential substrates for encoding information transfer between its components.

  16. Reorganization of Motor Cortex by Vagus Nerve Stimulation Requires Cholinergic Innervation.

    PubMed

    Hulsey, Daniel R; Hays, Seth A; Khodaparast, Navid; Ruiz, Andrea; Das, Priyanka; Rennaker, Robert L; Kilgard, Michael P

    2016-01-01

    Vagus nerve stimulation (VNS) paired with forelimb training drives robust, specific reorganization of movement representations in the motor cortex. The mechanisms that underlie VNS-dependent enhancement of map plasticity are largely unknown. The cholinergic nucleus basalis (NB) is a critical substrate in cortical plasticity, and several studies suggest that VNS activates cholinergic circuitry. We examined whether the NB is required for VNS-dependent enhancement of map plasticity in the motor cortex. Rats were trained to perform a lever pressing task and then received injections of the immunotoxin 192-IgG-saporin to selectively lesion cholinergic neurons of the NB. After lesion, rats underwent five days of motor training during which VNS was paired with successful trials. At the conclusion of behavioral training, intracortical microstimulation was used to document movement representations in motor cortex. VNS paired with forelimb training resulted in a substantial increase in the representation of proximal forelimb in rats with an intact NB compared to untrained controls. NB lesions prevent this VNS-dependent increase in proximal forelimb area and result in representations similar to untrained controls. Motor performance was similar between groups, suggesting that differences in forelimb function cannot account for the difference in proximal forelimb representation. Together, these findings indicate that the NB is required for VNS-dependent enhancement of plasticity in the motor cortex and may provide insight into the mechanisms that underlie the benefits of VNS therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Intraoperative Monitoring of Facial Nerve Motor-Evoked Potentials in Children.

    PubMed

    Bozinov, Oliver; Grotzer, Michael A; Sarnthein, Johannes

    2015-09-01

    To determine whether transcranial motor-evoked potential monitoring of the facial nerve (FNMEP) during eloquent tumor resection is feasible in children and can predict both immediate and postoperative facial nerve (FN) function. We included 24 consecutive procedures involving 21 patients (median age 5.5 years, range 5 months to 15 years, 8 female) who were operated on with FNMEP monitoring by the first author in 2013 and 2014. During surgery, we maintained a constant response amplitude by increasing the stimulation intensity and aimed to establish a warning criterion based on the "threshold-level" method. A threshold increase of greater than 20 mA for eliciting the FNMEP in the most reliable facial nerve target muscle was considered to be a prediction of reduced postoperative facial nerve function and consequently, a warning was given to the surgeon. The preoperative and early postoperative function was documented with the House-Brackmann grading system. Monitoring of the FNMEP was feasible in all the surgeries in at least one facial nerve target muscle. The orbicularis oris muscle yielded the best result (95% of the trials), followed by the mentalis (87%) and orbicularis oculi muscles (86%). The median stimulation threshold was initially 65 mA (range 40-110 mA) for the FNMEP and 60 mA (15-220 mA) for the motor-evoked potential of the thenar muscles. The FNMEP deterioration showed a sensitivity of 100% for House-Brackmann deterioration and specificity of 74%. Intraoperative FNMEP monitoring is feasible and safe in infants and children. We found no evidence that the procedures and thresholds should differ from FNMEP monitoring in adults. FNMEP monitoring provides valid evidence for FN function in pediatric eloquent area surgery; its use is complementary to direct electrical FN stimulation and continuous EMG monitoring of FN target muscles. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Development of regenerative peripheral nerve interfaces for motor control of neuroprosthetic devices

    NASA Astrophysics Data System (ADS)

    Kemp, Stephen W. P.; Urbanchek, Melanie G.; Irwin, Zachary T.; Chestek, Cynthia A.; Cederna, Paul S.

    2017-05-01

    Traumatic peripheral nerve injuries suffered during amputation commonly results in debilitating neuropathic pain in the affected limb. Modern prosthetic technologies allow for intuitive, simultaneous control of multiple degrees of freedom. However, these state-of-the-art devices require separate, independent control signals for each degree of freedom, which is currently not possible. As a result, amputees reject up to 75% of myoelectric devices preferring instead to use body-powered artificial limbs which offer subtle sensory feedback. Without meaningful and intuitive sensory feedback, even the most advanced myoelectric prostheses remain insensate, burdensome, and are associated with enormous cognitive demand and mental fatigue. The ideal prosthetic device is one which is capable of providing intuitive somatosensory feedback essential for interaction with the environment. Critical to the design of such a bioprosthetic device is the development of a reliable biologic interface between human and machine. This ideal patient-prosthetic interface allows for transmission of both afferent somatosensory information and efferent motor signals for a closed-loop feedback system of neural control. Our lab has developed the Regenerative Peripheral Nerve Interface (RPNI) as a biologic nerve interface designed for stable integration of a prosthetic device with transected peripheral nerves in a residual limb. The RPNI is constructed by surgically implanting the distal end of a transected peripheral nerve into an autogenous muscle graft. Animal experiments in our lab have shown recording of motor signals from RPNI's implanted into both rodents and monkeys. Here, we achieve high amplitude EMG signals with a high signal to noise (SNR) ratio.

  19. Scanning laser ophthalmoscopy of the optic nerve head in exfoliation glaucoma and ocular hypertension with exfoliation syndrome

    PubMed Central

    Harju, M.; Vesti, E.

    2001-01-01

    AIMS—To study the relation between optic nerve head topography (Heidelberg retina tomograph, HRT) and disc area, visual field index mean defect (MD), and intraocular pressure (IOP), and to see whether change in HRT parameters is associated with change in MD in a prospective follow up.
METHODS—80 consecutive patients (69 patients with exfoliation glaucoma and 11 with ocular hypertension combined with exfoliation syndrome) were examined before IOP reducing intervention and prospectively followed every 6 months for 2 years.
RESULTS—At the entry point, multiple regression analysis showed significant linear association between MD and all HRT parameters, when controlling for disc area. Disc area showed significant association with cup area, cup/disc area ratio, rim area, cup volume, and mean RNFL thickness. Six months after intervention IOP had decreased significantly. Reversible changes in cup area, cup/disc area ratio, rim area, cup volume, rim volume, mean cup depth, and maximum cup depth were associated with decrease in IOP. During the follow up period from 6 month to 2 years, IOP did not change significantly, and MD was used as a measure of progression of glaucoma. During this period, only cup shape measure among HRT parameters showed significant association with subsequent change in MD.
CONCLUSION—Disc area should be taken into account when using HRT to compare patients. Any effect of change in IOP should be also taken into account when using HRT in follow up. Cup shape measure is a promising indicator of progression of glaucomatous damage.

 PMID:11222334

  20. The release of acetylcholine from the spinal cord of the cat by antidromic stimulation of motor nerves

    PubMed Central

    Kuno, M.; Rudomin, P.

    1966-01-01

    1. ACh was measured in the effluent from the perfused lumbosacral cord of the cat with or without stimulation of the central ends of the cut left sciatic and femoral nerves after section of the left dorsal roots. 2. In about 30% of the preparations ACh was obtained in the samples collected at rest (average 3·3 ng/min); the amount of ACh release was increased 1·3-9 times by stimulation of the peripheral nerves. The average amount of ACh collected during stimulation of the peripheral nerves at 5/sec was 6·9 ng/min. Antidromic motor nerve impulses responsible for the ACh release were likely to be only those in alpha motor fibres. 3. There was a depression in ACh release/stimulus as the stimulus frequency was increased more than 10/sec. Such changes in ACh release with various stimulus frequencies were correlated with depression in the response of Renshaw cells to excitation through motor-axon collaterals. 4. Amounts of ACh release during stimulation of the peripheral nerves at 5/sec were significantly increased for 1 or 2 min after a short tetanic stimulation of the nerves. 5. Intravenous injection of dihydro-β-erythroidine did not reduce the amount of ACh release produced by stimulation of the peripheral nerves. 6. It is concluded that antidromic impulses in alpha motor fibres liberate ACh from the presynaptic terminals at the central synapses on Renshaw cells. PMID:5972160

  1. The release of acetylcholine from the spinal cord of the cat by antidromic stimulation of motor nerves.

    PubMed

    Kuno, M; Rudomin, P

    1966-11-01

    1. ACh was measured in the effluent from the perfused lumbosacral cord of the cat with or without stimulation of the central ends of the cut left sciatic and femoral nerves after section of the left dorsal roots.2. In about 30% of the preparations ACh was obtained in the samples collected at rest (average 3.3 ng/min); the amount of ACh release was increased 1.3-9 times by stimulation of the peripheral nerves. The average amount of ACh collected during stimulation of the peripheral nerves at 5/sec was 6.9 ng/min. Antidromic motor nerve impulses responsible for the ACh release were likely to be only those in alpha motor fibres.3. There was a depression in ACh release/stimulus as the stimulus frequency was increased more than 10/sec. Such changes in ACh release with various stimulus frequencies were correlated with depression in the response of Renshaw cells to excitation through motor-axon collaterals.4. Amounts of ACh release during stimulation of the peripheral nerves at 5/sec were significantly increased for 1 or 2 min after a short tetanic stimulation of the nerves.5. Intravenous injection of dihydro-beta-erythroidine did not reduce the amount of ACh release produced by stimulation of the peripheral nerves.6. It is concluded that antidromic impulses in alpha motor fibres liberate ACh from the presynaptic terminals at the central synapses on Renshaw cells.

  2. Functional coupling between motor and sensory nerves through contraction of sphincters in the pudendal area of the female cat.

    PubMed

    Lagunes-Córdoba, Roberto; Hernández, Pablo Rogelio; Raya, José Guadalupe; Muñoz-Martínez, E J

    2010-01-01

    The question of whether skin receptors might help in the perception of muscle contraction and body movement has not been settled. The present study gives direct evidence of skin receptor firing in close coincidence with the contraction of the vaginal and anal sphincters. The distal stump of the sectioned motor pudendal nerve was stimulated. Single shocks induced a wavelike increase in the lumen pressure of the distal vagina and the anal canal, as well as constriction of the vaginal introitus and the anus. The constriction pulls on and moves the surrounding skin, which was initially detected visually. In the present experiments, a thin strain gauge that pressed on the skin surface detected its displacement. Single shocks to the motor nerve induced a wave of skin movement with maximal amplitude at 5 mm from the anus and propagated with decrement beyond 35 mm. The peripheral terminals of the sensory pudendal nerve and the posterior femoral nerve supply the skin that moves. Sensory axons from both nerves fired in response to both tactile stimulation and the skin movement produced by the constriction of the orifices (motor-sensory coupling). In cats with all nerves intact, a single shock to the sensory nerves induced reflex waves of skin movement and lumen pressure (sensory-motor coupling). Both couplings provide evidence for a feedforward action that might help to maintain the female posture during mating and to the perception of muscle contraction.

  3. Cathepsin B-dependent motor neuron death after nerve injury in the adult mouse

    SciTech Connect

    Sun, Li; Wu, Zhou; Baba, Masashi; Peters, Christoph; Uchiyama, Yasuo; Nakanishi, Hiroshi

    2010-08-27

    Research highlights: {yields} Cathepsin B (CB), a lysosomal cysteine protease, is expressed in neuron and glia. {yields} CB increased in hypogrossal nucleus neurons after nerve injury in adult mice. {yields} CB-deficiency significantly increased the mean survival ratio of injured neurons. {yields} Thus, CB plays a critical role in axotomy-induced neuronal death in adult mice. -- Abstract: There are significant differences in the rate of neuronal death after peripheral nerve injury between species. The rate of neuronal death of motor neurons after nerve injury in the adult rats is very low, whereas that in adult mice is relatively high. However, the understanding of the mechanism underlying axotomy-induced motor neuron death in adult mice is limited. Cathepsin B (CB), a typical cysteine lysosomal protease, has been implicated in three major morphologically distinct pathways of cell death; apoptosis, necrosis and autophagic cell death. The possible involvement of CB in the neuronal death of hypogrossal nucleus (HGN) neurons after nerve injury in adult mice was thus examined. Quantitative analyses showed the mean survival ratio of HGN neurons in CB-deficient (CB-/-) adult mice after nerve injury was significantly greater than that in the wild-type mice. At the same time, proliferation of microglia in the injured side of the HGN of CB-/- adult mice was markedly reduced compared with that in the wild-type mice. On the injured side of the HGN in the wild-type adult mice, both pro- and mature forms of CB markedly increased in accordance with the increase in the membrane-bound form of LC3 (LC3-II), a marker protein of autophagy. Furthermore, the increase in CB preceded an increase in the expression of Noxa, a major executor for axotomy-induced motor neuron death in the adult mouse. Conversely, expression of neither Noxa or LC3-II was observed in the HGN of adult CB-/- mice after nerve injury. These observations strongly suggest that CB plays a critical role in axotomy

  4. Relationship between vitamin B12 and sensory and motor peripheral nerve function in older adults.

    PubMed

    Leishear, Kira; Boudreau, Robert M; Studenski, Stephanie A; Ferrucci, Luigi; Rosano, Caterina; de Rekeneire, Nathalie; Houston, Denise K; Kritchevsky, Stephen B; Schwartz, Ann V; Vinik, Aaron I; Hogervorst, Eva; Yaffe, Kristine; Harris, Tamara B; Newman, Anne B; Strotmeyer, Elsa S

    2012-06-01

    To examine whether deficient B12 status or low serum B12 levels are associated with worse sensory and motor peripheral nerve function in older adults. Cross-sectional. Health, Aging and Body Composition Study. Two thousand two hundred and eighty-seven adults aged 72 to 83 (mean 76.5 ± 2.9; 51.4% female; 38.3% black). Low serum B12 was defined as serum B12 less than 260 pmol/L, and deficient B12 status was defined as B12 less than 260 pmol/L, methylmalonic acid (MMA) greater than 271 nmol/L, and MMA greater than 2-methylcitrate. Peripheral nerve function was assessed according to peroneal nerve conduction amplitude and velocity (NCV) (motor), 1.4 g/10 g monofilament detection, average vibration threshold detection, and peripheral neuropathy symptoms (numbness, aching or burning pain, or both) (sensory). B12-deficient status was found in 7.0% of participants, and an additional 10.1% had low serum B12 levels. B12 deficient status was associated with greater insensitivity to light (1.4 g) touch (odds ratio = 1.50, 95% confidence interval = 1.06-2.13) and worse NCV (42.3 vs 43.5 m/s) (β = -1.16, P = .01) after multivariable adjustment for demographics, lifestyle factors, and health conditions. Associations were consistent for the alternative definition using low serum B12 only. No significant associations were found for deficient B12 status or the alternative low serum B12 definition and vibration detection, nerve conduction amplitude, or peripheral neuropathy symptoms. Poor B12 (deficient B12 status and low serum B12) is associated with worse sensory and motor peripheral nerve function. Nerve function impairments may lead to physical function declines and disability in older adults, suggesting that prevention and treatment of low B12 levels may be important to evaluate. © 2012, Copyright the Authors Journal compilation © 2012, The American Geriatrics Society.

  5. Perineurial glia require Notch signaling during motor nerve development but not regeneration

    PubMed Central

    Binari, Laura A.; Lewis, Gwendolyn M.; Kucenas, Sarah

    2013-01-01

    Motor nerves play the critical role of shunting information out of the CNS to targets in the periphery. Their formation requires the coordinated development of distinct cellular components, including motor axons and the Schwann cells and perineurial glia that ensheath them. During nervous system assembly, these glial cells must migrate long distances and terminally differentiate, ensuring the efficient propagation of action potentials. Although we know quite a bit about the mechanisms that control Schwann cell development during this process, nothing is known about the mechanisms that mediate the migration and differentiation of perineurial glia. Using in vivo imaging in zebrafish, we demonstrate that Notch signaling is required for both perineurial migration and differentiation during nerve formation, but not regeneration. Interestingly, loss of Notch signaling in perineurial cells also causes a failure of Schwann cell differentiation, demonstrating that Schwann cells require perineurial glia for aspects of their own development. These studies describe a novel mechanism that mediates multiple aspects of perineurial development and reveal the critical importance of perineurial glia for Schwann cell maturation and nerve formation. PMID:23467342

  6. Responses in the rat thalamus to whisker movements produced by motor nerve stimulation

    PubMed Central

    Brown, A. W. S.; Waite, Phil M. E.

    1974-01-01

    1. The effect of electrical stimulation of the motor nerve supplying the whiskers on the activity of single cells in the vibrissal region of the ventrobasal complex of the thalamus has been studied in rats under urethane anaesthesia. 2. The stimulation caused protraction of the ipsilateral whiskers. 60% of the cells which fired to mechanical movements of the whiskers were found to respond to this electrical stimulus with 1-2 impulses at short latency (average 7·7 msec), provided the stimulus was sufficient to move the whiskers. 3. When the moving whiskers hit a barrier, 92% of the cells responded to the stimulus. The most effective position of the barrier was in front of the whiskers, although other positions often produced a response as well. Static displacement of the whiskers, particularly in the forward direction, could abolish the response or increase its latency. 4. The following-frequencies for these cells were 5-10 stimuli/sec. Combinations of electrical stimuli with mechanical ramp movements of the whiskers showed that similar recovery times followed both types of stimuli. 5. These results are compared with those reported from studies in the afferent nerve fibres after electrical stimulation of the motor nerve and also with responses in the thalamus following mechanical movements of the whiskers. The possible importance of the latency of these sensory responses is considered. PMID:4840852

  7. Intrinsic and therapeutic factors determining the recovery of motor function after peripheral nerve transection.

    PubMed

    Skouras, Emmanouil; Ozsoy, Umut; Sarikcioglu, Levent; Angelov, Doychin N

    2011-07-01

    Insufficient recovery after peripheral nerve injury has been attributed to (i) poor pathfinding of regrowing axons, (ii) excessive collateral axonal branching at the lesion site and (iii) polyneuronal innervation of the neuromuscular junctions (NMJ). The facial nerve transection model has been used initially to measure restoration of function after varying therapies and to examine the mechanisms underlying their effects. Since it is very difficult to control the navigation of several thousand axons, efforts concentrated on collateral branching and NMJ-polyinnervation. Treatment with antibodies against trophic factors to combat branching improved the precision of reinnervation, but had no positive effects on functional recovery. This suggested that polyneuronal reinnervation--rather than collateral branching--may be the critical limiting factor. The former could be reduced by pharmacological agents known to perturb microtubule assembly and was followed by recovery of function. Because muscle polyinnervation is activity-dependent and can be manipulated, attempts to design a clinically feasible therapy were performed by electrical stimulation or by soft tissue massage. Electrical stimulation applied to the transected facial nerve or to paralysed facial muscles did not improve vibrissal motor performance and failed to diminish polyinnervation. In contrast, gentle stroking of the paralysed muscles (vibrissal, orbicularis oculi, tongue musculature) resulted in full recovery of function. This manual stimulation was also effective after hypoglossal-facial nerve suture and after interpositional nerve grafting, but not after surgical reconstruction of the median nerve. All these findings raise hopes that clinically feasible and effective therapies could be soon designed and tested. Copyright © 2011 Elsevier GmbH. All rights reserved.

  8. Gallic acid and exercise training improve motor function, nerve conduction velocity but not pain sense reflex after experimental sciatic nerve crush in male rats.

    PubMed

    Hajimoradi, Maryam; Fazilati, Mohammad; Gharib-Naseri, Mohammad Kazem; Sarkaki, Alireza

    2015-01-01

    The aim of present study was to evaluate the effects of oral administration of gallic acid (GA) for 21 days alone and in combination with exercise on nerve conduction velocity and sensory and motor functions in rats with sciatic nerve crush. Seventy adult male Wistar rats (250-300 g) were divided randomly into 7 groups with 10 in each: 1) Control (Cont), 2) Crushed + Vehicle (Cr +Veh), 3-5) Crushed + gallic acid (Cr+GA) (50, 100, and 200 mg/kg/2 mL, orally), 6) Crushed + exercise (Cr+Exe), and 7) Crushed + exercise + effective dose of gallic acid (Cr+Exe +GA200) for 21 days. In order to establish an animal model of sciatic nerve crush, equivalent to 7 kg of force pressed on 2-3 mm of sciatic nerve for 30 s, three times with 30 s intervals. Pain sense reflex in hot plate, motor coordination in rotarod, and sciatic nerve conduction velocity (SNCV) in all groups were tested. Data were analyzed using one-way ANOVA followed by Tukey's post hoc test and p<0.05 has assigned as the significant difference. Pain threshold was increased significantly in untreated crushed rats while motor function and SNCV were decreased in all groups with nerve crush (p<0.05, p<0.01, p<0.001 vs. control). Pain reflex latency was not changed in treated groups. Motor coordination and SNCV were improved in groups Cr+GA200 and Cr+Exe + GA200 (p<0.05, p<0.01 vs. Cr+Veh). GA, dose-dependently, may have therapeutic potential to improve the peripheral nerve degeneration, which is most likely related, at least in part, to its antioxidant and therapeutic properties.

  9. Transplantation of embryonic motor neurons into peripheral nerve combined with functional electrical stimulation restores functional muscle activity in the rat sciatic nerve transection model.

    PubMed

    Kurimoto, Shigeru; Kato, Shuichi; Nakano, Tomonori; Yamamoto, Michiro; Takanobu, Nishizuka; Hirata, Hitoshi

    2016-10-01

    Reinnervation of denervated muscle by motor neurons transplanted into the peripheral nerve may provide the potential to excite muscles artificially with functional electrical stimulation (FES). Here we investigated whether transplantation of embryonic motor neurons into peripheral nerve combined with FES restored functional muscle activity in adult Fischer 344 rats after transection of the sciatic nerve. One week after sciatic nerve transection, cell culture medium containing (cell transplantation group, n = 6) or lacking (surgical control group, n = 6) dissociated embryonic spinal neurons was injected into the distal stump of the tibial and peroneal nerves. Electrophysiological and tissue analyses were performed in the cell transplantation and surgical control groups 12 weeks after transplantation, as well as a in naïve control group (n = 6) that received no surgery. In the cell transplantation group, ankle angle was measured during gait, with and without FES of the peroneal nerve. Ankle angle at mid-swing was more flexed during gait with FES (26.6 ± 8.7°) than gait without FES (51.4 ± 12.8°, p = 0.011), indicating that transplantated motor neurons in conjunction with FES restored ankle flexion in gait, even though no neural connection between central nervous system and muscle was present. These results indicate that transplantation of embryonic motor neurons into peripheral nerve combined with FES can provide a novel treatment strategy for paralysed muscles. Copyright © 2013 John Wiley & Sons, Ltd.

  10. Structural protein transport in elongating motor axons after sciatic nerve crush. Effect of a conditioning lesion.

    PubMed

    McQuarrie, I G

    1986-12-01

    In elongating motor axons of the rat sciatic nerve, the maximum outgrowth rate increased from 4.6 to 5.3 mm/d (5.3-6.1 X 10(-8) m/s) when a testing lesion of spinal nerves L4 and L5 was preceded 2 wk earlier by a conditioning lesion of the sciatic nerve. Axonal outgrowth was examined by measuring the transport of 35[S]methionine-labeled structural proteins (tubulin, actin, and neurofilament triplet) from "parent" axon stumps into "daughter" axon sprouts. Since these proteins are conveyed by the slow component of axonal transport at 1-5 mm/d (1.2-6.0 X 10(-8) m/s), the isotope was injected into the spinal cord 1 wk before the testing lesion. Nerves were removed 8 d after the testing lesion, sectioned into 3-mm segments, and homogenized; soluble proteins were separated by polyacrylamide gel electrophoresis. Fluorographs were used as templates to identify gel segments for removal, solubilization, and liquid scintillation counting. Distributions of mean radioactivity for tubulin, actin, and neurofilament triplet were plotted for animals receiving a conditioning vs sham-conditioning lesion. Greater amounts of tubulin and actin were transported into daughter axons in the conditioned group. Tubulin was mainly increased in axon shafts, whereas actin was mainly increased in axon tips. These findings suggest that the axonal transport of tubulin and actin governs the rate of elongation.

  11. Vagus Nerve Stimulation Delivered with Motor Training Enhances Recovery of Function after Traumatic Brain Injury

    PubMed Central

    Schmid, Ariel N.; Kim, Lily J.; Abe, Caroline M.; Trieu, Jenny L.; Choua, Connie; Hays, Seth A.; Kilgard, Michael P.; Rennaker, Robert L.

    2016-01-01

    Abstract Traumatic Brain Injury (TBI) is one of the largest health problems in the United States, and affects nearly 2 million people every year. The effects of TBI, including weakness and loss of coordination, can be debilitating and last years after the initial injury. Recovery of motor function is often incomplete. We have developed a method using electrical stimulation of the vagus nerve paired with forelimb use by which we have demonstrated enhanced recovery from ischemic and hemorrhagic stroke. Here we have tested the hypothesis that vagus nerve stimulation (VNS) paired with physical rehabilitation could enhance functional recovery after TBI. We trained rats to pull on a handle to receive a food reward. Following training, they received a controlled-cortical impact (CCI) in the forelimb area of motor cortex opposite the trained forelimb, and were then randomized into two treatment groups. One group of animals received VNS paired with rehabilitative therapy, whereas another group received rehabilitative therapy without VNS. Following CCI, volitional forelimb strength and task success rate in all animals were significantly reduced. VNS paired with rehabilitative therapy over a period of 5 weeks significantly increased recovery of both forelimb strength and success rate on the isometric pull task compared with rehabilitative training without VNS. No significant improvement was observed in the Rehab group. Our findings indicate that VNS paired with rehabilitative therapy enhances functional motor recovery after TBI. PMID:26058501

  12. Crosstalk between p38, Hsp25 and Akt in spinal motor neurons after sciatic nerve injury

    NASA Technical Reports Server (NTRS)

    Murashov, A. K.; Ul Haq, I.; Hill, C.; Park, E.; Smith, M.; Wang, X.; Wang, X.; Goldberg, D. J.; Wolgemuth, D. J.

    2001-01-01

    The p38 stress-activated protein kinase pathway is involved in regulation of phosphorylation of Hsp25, which in turn regulates actin filament dynamic in non-neuronal cells. We report that p38, Hsp25 and Akt signaling pathways were specifically activated in spinal motor neurons after sciatic nerve axotomy. The activation of the p38 kinase was required for induction of Hsp25 expression. Furthermore, Hsp25 formed a complex with Akt, a member of PI-3 kinase pathway that prevents neuronal cell death. Together, our observations implicate Hsp25 as a central player in a complex system of signaling that may both promote regeneration of nerve fibers and prevent neuronal cell death in the injured spinal cord.

  13. Crosstalk between p38, Hsp25 and Akt in spinal motor neurons after sciatic nerve injury

    NASA Technical Reports Server (NTRS)

    Murashov, A. K.; Ul Haq, I.; Hill, C.; Park, E.; Smith, M.; Wang, X.; Wang, X.; Goldberg, D. J.; Wolgemuth, D. J.

    2001-01-01

    The p38 stress-activated protein kinase pathway is involved in regulation of phosphorylation of Hsp25, which in turn regulates actin filament dynamic in non-neuronal cells. We report that p38, Hsp25 and Akt signaling pathways were specifically activated in spinal motor neurons after sciatic nerve axotomy. The activation of the p38 kinase was required for induction of Hsp25 expression. Furthermore, Hsp25 formed a complex with Akt, a member of PI-3 kinase pathway that prevents neuronal cell death. Together, our observations implicate Hsp25 as a central player in a complex system of signaling that may both promote regeneration of nerve fibers and prevent neuronal cell death in the injured spinal cord.

  14. Acceptable differences in sensory and motor latencies between the median and ulnar nerves.

    PubMed

    Grossart, Elizabeth A; Prahlow, Nathan D; Buschbacher, Ralph M

    2006-01-01

    The median and ulnar nerves are often studied during the same electrodiagnostic examination. The sensory and motor latencies of these nerves have been compared to detect a common electrodiagnostic entity: median neuropathy at the wrist. However, this comparison could also be used to diagnose less common ulnar pathology. For this reason, it is important to establish normal values for comparing median and ulnar sensory and motor latencies. Previous research deriving these differences in latency has had some limitations. The purpose of this study was to derive an improved normative database for the acceptable differences in latency between the median and ulnar sensory and motor nerves of the same limb. Median and ulnar sensory and motor latencies were obtained from 219 and 238 asymptomatic risk-factor-free subjects, respectively. An analysis of variance was performed to determine whether physical characteristics, specifically age, race, gender, height, or body mass index (as an indicator of obesity), correlated with differences in latency. Differences in sensory latencies were unaffected by physical characteristics. The upper limit of normal difference between median and ulnar (median longer than ulnar) onset latency was 0.5 ms (97th percentile), whereas the peak latency value was 0.4 ms (97th percentile). The upper limit of normal difference between ulnar-versus-median (ulnar longer than median) onset latency was 0.3 ms (97th percentile), whereas the peak-latency value was 0.5 ms (97th percentile). The mean difference in motor latencies correlated with age, with older subjects having a greater variability. In subjects aged 50 and over, the mean difference in median-versus-ulnar latency was 0.9 ms +/- 0.4 ms. The upper limit of normal difference (median longer than ulnar) was 1.7 ms (97th percentile). The upper limit of normal ulnar motor latency is attained if the ulnar latency comes within 0.3 ms of the median latency. In individuals less than 50 years of age, the

  15. Enhancement by Anemonia sulcata toxin II of spontaneous quantal transmitter release from mammalian motor nerve terminals.

    PubMed

    Molgo, J; Lemeignan, M; Tazieff-Depierre, F

    1986-01-01

    The action of Anemonia sulcata toxin II (ATX-II) on spontaneous quantal transmitter release from motor nerve terminals was investigated by recording miniature end-plate potentials (MEPPs) from isolated mouse phrenic nerve--hemidiaphragm nerve--muscle preparations. ATX-II (3.2 microM) when applied for 3-40 min to junctions bathed in a normal ionic medium enhanced about one hundred fold the rate of spontaneous MEPPs. Concomitantly, ATX-II depolarized the muscle fiber. The effect of the toxin on MEPP frequency was markedly reduced when junctions were exposed to Na-deficient solutions or pre-treated with dantrolene sodium (10 microM). ATX-II (0.24-3.2 microM) increased MEPP rate in junctions exposed to a Ca-free medium containing 2 mM EGTA and 2 mM Mg2+ in a dose- and time-dependent manner. Tetrodotoxin (0.2-1 microM) prevented the effects of ATX-II on MEPP frequency and on the resting membrane potential of muscle fibers. Tetrodotoxin also antagonized the acceleration of MEPP induced by ATX-II. The experimental findings suggest that ATX-II acts to increase quantal transmitter output from motor nerve terminals by enhancing Na+ influx through tetrodotoxin-sensitive presynaptic channels, since ATX-II action does not appear to depend upon entry of Ca2+ from the extracellular medium. It is likely that ATX-II, by increasing intraterminal Na+ concentration, may trigger calcium release from internal stores.

  16. Cranial nerves palsy as an initial feature of an early onset distal hereditary motor neuropathy--a new distal hereditary motor neuropathy phenotype.

    PubMed

    Haberlová, J; Claeys, K G; De Jonghe, P; Seeman, P

    2009-06-01

    Distal hereditary motor neuropathy is a heterogeneous group of disorders characterised by a pure motor axonal neuropathy. It is occasionally associated with additional signs such as facial weakness, vocal cord paralysis, weakness of the diaphragm, and pyramidal signs. Although predominantly the inheritance is autosomal dominant, all types of inheritance have been described. Here we report a Czech family with cranial nerves palsy as an initial feature of a non progressive infantile onset dominant distal hereditary motor neuropathy. This family may represent a new subtype of distal hereditary motor neuropathy.

  17. Location of motor fibers within branches of the recurrent laryngeal nerve with extralaryngeal terminal bifurcation; Functional identification by intraoperative neuromonitoring.

    PubMed

    Gurleyik, Emin

    2015-11-01

    Extralaryngeal terminal bifurcation (ETB) of the recurrent laryngeal nerve (RLN) is an anatomic variation that threatens the safety of thyroid operation. Therefore, it is important to identify motor function in nerve branches to preserve appropriate motor activity. Intraoperative neuromonitoring (IONM) is an accepted procedure to identify motor function of the RLN. We established the operative anatomy of RLNs with ETB in 47 patients. The main trunk, bifurcation point, and the branches were identified and exposed completely during thyroid operation. The location of motor fibers within nerve branches was investigated by identifying motor function via IONM. Wave amplitudes were recorded after electrophysiologic stimulation. A total of 61 RLNs had ETBs with anterior and posterior branches. Bifurcation occurred early along the pre-arterial (proximal) segment in 13% of bifid RLNs. IONM showed motor function in all anterior branches. IONM identified motor activity in 4 (18%) posterior branches of 22 right, 3 (8%) posterior branches of 39 left, and 7 (12%) posterior branches of all 61 RLNs with ETB. The rate of recorded wave amplitudes of motor function in seven posterior branches was between 14 and 78% of those of corresponding anterior branches. In the RLN, the anterior branch always and the posterior branch uncommonly contain motor fibers. Wave amplitude analysis showed that motor function in the posterior branch is weaker than that in the anterior branch. On the basis of the location of motor fibers in both branches, total exposure and preservation of anatomy and function of all branches of the RLN is mandatory for complication-free thyroid surgery. Electrophysiologic testing may be as an important adjunct to visualization of the nerve with anatomic variation. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Size-related differences in the branching pattern of the motor nerve terminals in triangularis sterni muscle of the mouse.

    PubMed

    Tomasi, J; Fenol, R; Santafe, M; Mayayo, E

    1989-01-01

    A light microscopy morphometric study was performed in singly innervated synaptic areas of the triangularis sterni muscle of the normal adult Swiss mouse. Investigating mechanisms of the motor nerve growth control, we tested the hypothesis that significant differences in the nerve terminal branching pattern can be detected between different populations of nerve endings classified according to their arborization complexity or size. The main observations of this morphometric study are first, that the mean segment length of the terminal arborization between branch points behaves as an independent variable from the remaining parameters; the mean value of this parameter did not change in nerve endings of differing size and complexity. Secondly, the increase in size of the nerve endings is accompanied by a significant reduction in the mean length of the distal free-end segments. Results are discussed in the context of the possible regulatory mechanisms governing nerve terminal growth and remodelling.

  19. Sensory-motor axonal polyneuropathy involving cranial nerves: An uncommon manifestation of disulfiram toxicity.

    PubMed

    Santos, Telma; Martins Campos, António; Morais, Hugo

    2017-01-01

    Disulfiram (tetraethylthiuram disulfide) has been used for the treatment of alcohol dependence. An axonal sensory-motor polyneuropathy with involvement of cranial pairs due to disulfiram is exceedingly rare. The authors report a unique case of an extremely severe axonal polyneuropathy involving cranial nerves that developed within weeks after a regular dosage of 500mg/day disulfiram. To the authors best knowledge, such a severe and rapidly-progressive course has never been described with disulfiram dosages of only 500mg/day.

  20. Using Acute Performance on a Comprehensive Neurocognitive, Vestibular, and Ocular Motor Assessment Battery to Predict Recovery Duration After Sport-Related Concussions.

    PubMed

    Sufrinko, Alicia M; Marchetti, Gregory F; Cohen, Paul E; Elbin, R J; Re, Valentina; Kontos, Anthony P

    2017-04-01

    A sport-related concussion (SRC) is a heterogeneous injury that requires a multifaceted and comprehensive approach for diagnosis and management, including symptom reports, vestibular/ocular motor assessments, and neurocognitive testing. To determine which acute (eg, within 7 days) vestibular, ocular motor, neurocognitive, and symptom impairments predict the duration of recovery after an SRC. Cohort study (prognosis); Level of evidence, 2. Sixty-nine patients with a mean age of 15.3 ± 1.9 years completed a neurocognitive, vestibular/ocular motor, and symptom assessment within 7 days of a diagnosed concussion. Patients were grouped by recovery time: ≤14 days (n = 27, 39.1%), 15-29 days (n = 25, 36.2%), and 30-90 days (n = 17, 24.6%). Multinomial regression was used to identify the best subset of predictors associated with prolonged recovery relative to ≤14 days. Acute visual motor speed and cognitive-migraine-fatigue symptoms were associated with an increased likelihood of recovery times of 30-90 days and 15-29 days relative to a recovery time of ≤14 days. A model with visual motor speed and cognitive-migraine-fatigue symptoms within the first 7 days of an SRC was 87% accurate at identifying patients with a recovery time of 30-90 days. The current study identified cognitive-migraine-fatigue symptoms and visual motor speed as the most robust predictors of protracted recovery after an SRC according to the Post-concussion Symptom Scale, Immediate Post-concussion Assessment and Cognitive Testing, and Vestibular/Ocular Motor Screening (VOMS). While VOMS components were sensitive in identifying a concussion, they were not robust predictors for recovery. Clinicians may consider particular patterns of performance on clinical measures when providing treatment recommendations and discussing anticipated recovery with patients.

  1. Percutaneous sciatic nerve block with tramadol induces analgesia and motor blockade in two animal pain models

    PubMed Central

    Sousa, A.M.; Ashmawi, H.A.; Costa, L.S.; Posso, I.P.; Slullitel, A.

    2011-01-01

    Local anesthetic efficacy of tramadol has been reported following intradermal application. Our aim was to investigate the effect of perineural tramadol as the sole analgesic in two pain models. Male Wistar rats (280-380 g; N = 5/group) were used in these experiments. A neurostimulation-guided sciatic nerve block was performed and 2% lidocaine or tramadol (1.25 and 5 mg) was perineurally injected in two different animal pain models. In the flinching behavior test, the number of flinches was evaluated and in the plantar incision model, mechanical and heat thresholds were measured. Motor effects of lidocaine and tramadol were quantified and a motor block score elaborated. Tramadol, 1.25 mg, completely blocked the first and reduced the second phase of the flinching behavior test. In the plantar incision model, tramadol (1.25 mg) increased both paw withdrawal latency in response to radiant heat (8.3 ± 1.1, 12.7 ± 1.8, 8.4 ± 0.8, and 11.1 ± 3.3 s) and mechanical threshold in response to von Frey filaments (459 ± 82.8, 447.5 ± 91.7, 320.1 ± 120, 126.43 ± 92.8 mN) at 5, 15, 30, and 60 min, respectively. Sham block or contralateral sciatic nerve block did not differ from perineural saline injection throughout the study in either model. The effect of tramadol was not antagonized by intraperitoneal naloxone. High dose tramadol (5 mg) blocked motor function as well as 2% lidocaine. In conclusion, tramadol blocks nociception and motor function in vivo similar to local anesthetics. PMID:22183244

  2. Relationship Between Visual Field Sensitivity and Retinal Nerve Fiber Layer Thickness Measured by Scanning Laser Polarimetry and Optical Coherence Tomography in Normal, Ocular Hypertensive and Glaucomatous Eyes

    PubMed Central

    Lleó-Pérez, Antonio; Ortuño-Soto, Amparo; Rahhal, M.S.; Sanchis-Gimeno, Juan A.

    2010-01-01

    Purpose To evaluate the correlation between automated achromatic perimetry (AAP) and the output of two retinal nerve fiber layer (RNFL) analysers: scanning laser polarimetry (GDx-VCC) and optical coherence tomography (OCT). Methods Quantitative RNFL measurements with GDx-VCC and Stratus-OCT were obtained in one eye from 52 healthy subjects, 38 ocular hypertensive (OHT) patients and 94 glaucomatous patients. All patients underwent a complete examination, including AAP using the Swedish interactive threshold algorithm (SITA). The relationship between RNFL measurements and SITA visual field global indices were assessed by means of the following methods: analysis of variance, bivariate Pearson's correlation coefficient, multivariate linear regression techniques and nonlinear regression models, and the coefficient of determination (r2) was calculated. Results RNFL thickness values were significantly lower in glaucomatous eyes than in healthy and ocular hypertensive eyes for both nerve fiber analysers (P≤0.001), except for the inferior 120° average thickness in GDx-VCC. Linear regression models constructed for GDx-VCC measurements and OCT-derived RNFL thickness with SITA visual field global indices demonstrated that, for the mean deviation, the only predictor in the model was the nerve fiber indicator for GDx-VCC (r2=0.255), and for the pattern standard deviation, the predictors in the model were the nerve fiber indicator for GDx-VCC (r2=0.246) and the maximum thickness in the superior quadrant for Stratus-OCT (r2=0.196). The best curvilinear fit was obtained with the cubic model. Conclusions Quantitative measurements of RNFL thickness using either GDx-VCC or OCT correlate moderately with visual field global indices in moderate glaucoma patients. We did not find a correlation between visual field global indices and RNFL thickness in early glaucoma patients. Further study is needed to develop new analytical methods that will increase RNFL analyser's sensitivity in

  3. Positive or negative feedback of optokinetic signals: degree of the misrouted optic flow determines system dynamics of human ocular motor behavior.

    PubMed

    Chen, Chien-Cheng; Bockisch, Christopher J; Olasagasti, Itsaso; Weber, Konrad P; Straumann, Dominik; Huang, Melody Ying-Yu

    2014-04-09

    The optokinetic system in healthy humans is a negative-feedback system that stabilizes gaze: slow-phase eye movements (i.e., the output signal) minimize retinal slip (i.e., the error signal). A positive-feedback optokinetic system may exist due to the misrouting of optic fibers. Previous studies have shown that, in a zebrafish mutant with a high degree of the misrouting, the optokinetic response (OKR) is reversed. As a result, slow-phase eye movements amplify retinal slip, forming a positive-feedback optokinetic loop. The positive-feedback optokinetic system cannot stabilize gaze, thus leading to spontaneous eye oscillations (SEOs). Because the misrouting in human patients (e.g., with a condition of albinism or achiasmia) is partial, both positive- and negative-feedback loops co-exist. How this co-existence affects human ocular motor behavior remains unclear. We presented a visual environment consisting of two stimuli in different parts of the visual field to healthy subjects. One mimicked positive-feedback optokinetic signals and the other preserved negative-feedback optokinetic signals. By changing the ratio and position of the visual field of these visual stimuli, various optic nerve misrouting patterns were simulated. Eye-movement responses to stationary and moving stimuli were measured and compared with computer simulations. The SEOs were correlated with the magnitude of the virtual positive-feedback optokinetic effect. We found a correlation among the simulated misrouting, the corresponding OKR, and the SEOs in humans. The proportion of the simulated misrouting needed to be greater than 50% to reverse the OKR and at least greater than or equal to 70% to evoke SEOs. Once the SEOs were evoked, the magnitude positively correlated to the strength of the positive-feedback OKR. This study provides a mechanism of how the misrouting of optic fibers in humans could lead to SEOs, offering a possible explanation for a subtype of infantile nystagmus syndrome (INS).

  4. Identifying motor and sensory myelinated axons in rabbit peripheral nerves by histochemical staining for carbonic anhydrase and cholinesterase activities

    NASA Technical Reports Server (NTRS)

    Riley, Danny A.; Sanger, James R.; Matloub, Hani S.; Yousif, N. John; Bain, James L. W.

    1988-01-01

    Carbonic anhydrase (CA) and cholinesterase (CE) histochemical staining of rabbit spinal nerve roots and dorsal root ganglia demonstrated that among the reactive myeliated axons, with minor exceptions, sensory axons were CA positive and CE negative whereas motor axons were CA negative and CE positive. The high specificity was achieved by adjusting reaction conditions to stain subpopulations of myelinated axons selectively while leaving 50 percent or so unstained. Fixation with glutaraldehyde appeared necessary for achieving selectivity. Following sciatic nerve transection, the reciprocal staining pattern persisted in damaged axons and their regenerating processes which formed neuromas within the proximal nerve stump. Within the neuromas, CA-stained sensory processes were elaborated earlier and in greater numbers than CE-stained regenerating motor processes. The present results indicate that histochemical axon typing can be exploited to reveal heterogeneous responses of motor and sensory axons to injury.

  5. Identifying motor and sensory myelinated axons in rabbit peripheral nerves by histochemical staining for carbonic anhydrase and cholinesterase activities

    NASA Technical Reports Server (NTRS)

    Riley, Danny A.; Sanger, James R.; Matloub, Hani S.; Yousif, N. John; Bain, James L. W.

    1988-01-01

    Carbonic anhydrase (CA) and cholinesterase (CE) histochemical staining of rabbit spinal nerve roots and dorsal root ganglia demonstrated that among the reactive myeliated axons, with minor exceptions, sensory axons were CA positive and CE negative whereas motor axons were CA negative and CE positive. The high specificity was achieved by adjusting reaction conditions to stain subpopulations of myelinated axons selectively while leaving 50 percent or so unstained. Fixation with glutaraldehyde appeared necessary for achieving selectivity. Following sciatic nerve transection, the reciprocal staining pattern persisted in damaged axons and their regenerating processes which formed neuromas within the proximal nerve stump. Within the neuromas, CA-stained sensory processes were elaborated earlier and in greater numbers than CE-stained regenerating motor processes. The present results indicate that histochemical axon typing can be exploited to reveal heterogeneous responses of motor and sensory axons to injury.

  6. Two protein trafficking processes at motor nerve endings unveiled by botulinum neurotoxin E.

    PubMed

    Lawrence, Gary; Wang, Jiafu; Chion, C K N Kwo; Aoki, K Roger; Dolly, J Oliver

    2007-01-01

    The unique ability of a family of botulinum neurotoxins to block neuroexocytosis specifically-by selective interaction with peripheral cholinergic nerve endings, endocytotic uptake, translocation to the cytosol, and enzymic cleavage of essential proteins-underlies their increasing therapeutic applications. Although clinical use of type A is most widespread due to its prolonged inactivation of the synaptosomal-associated protein of 25 kDa, botulinum neurotoxin E cleaves this same target but at a different bond and exhibits faster onset of neuromuscular paralysis. Herein, insights were gained into the different dynamics of action of types A and E toxins, which could help in designing variants with new pharmacological profiles. Natural and recombinant type E dichain forms showed similar proteolytic and neuromuscular paralytic activities. The neuroparalysis induced by type E toxin was accelerated between 21 and 35 degrees C and attenuated by bafilomycin A1. Temperature elevation also revealed an unanticipated bipartite dose response indicative of two distinct internalization processes, one being independent of temperature and the other dependent. Although elevating the temperature also hastened intoxication by type A, a second uptake mechanism was not evident. Increasing the frequency of nerve stimulation raised the uptake of type E via both processes, but the enhanced trafficking through the temperature-dependent pathway was only seen at 35 degrees C. These novel observations reveal that two membrane retrieval mechanisms are operative at motor nerve terminals which type E toxin exploits to gain entry via an acidification-dependent step, whereas A uses only one.

  7. The superior laryngeal nerve: its projection to the dorsal motor nucleus of the vagus in the guinea pig.

    PubMed

    Basterra, J; Chumbley, C C; Dilly, P N

    1988-01-01

    The distribution of neurons in the dorsal motor nucleus of the vagus nerve (DMNV) that innervate the supraglottic and glottic areas of the larynx of the guinea pig have been studied using the horseradish peroxidase (HRP) technique. Following soaking of the superior laryngeal nerve in a solution of HRP, labeled neurons were always located ipsilaterally, at levels between the estria acustica and the caudal end of the inferior olivary nucleus. Characteristically, the neurons were small or medium in size.

  8. Stimulus-response curve of human motor nerves: multicenter assessment of various indexes.

    PubMed

    Boërio, D; Hogrel, J-Y; Lefaucheur, J-P; Wang, F C; Verschueren, A; Pouget, J; Carrera, E; Kuntzer, T

    2008-02-01

    The value of various indexes to characterize the stimulus-response curve of human motor nerves was assessed in 40 healthy subjects recruited from four European centers of investigation (Créteil, Lausanne, Liège, Marseille). Stimulus-response curves were established by stimulating the right median and ulnar motor nerves at the wrist, with stimulus durations of 0.05 and 0.5 ms. The following parameters were studied: the threshold intensity of stimulation to obtain 10% (I 10), 50% (I 50), and 90% (I 90) of the maximal compound muscle action potential, the ratios I 10/I 50, I 90/I 50, (I 90 - I 10)/I 10, (I 90-I 50)/I 50, and (I 50 - I 10)/I 10, and the slopes of the stimulus-response curves with or without normalization to I 50. For each parameter, within-center variability and reproducibility (in a test-retest study) were assessed and between-center comparisons were made. For most of the parameters, the results varied significantly within and between the centers. Within the centers, only the ratios I 10/I 50 and I 90/I 50 were found constant and reproducible. Between the centers, the absolute intensity thresholds (I 10, I 50, I 90) and the ratio I 90/I 50 did not show significant differences at stimulus duration of 0.5 ms, whatever the stimulated nerve. The reduced variability and good reproducibility of the ratios I 10/I 50 and I 90/I 50 open perspectives in neurophysiological practice for the use of these indexes of the stimulus-response curve, a rapid and noninvasive test.

  9. Plantar pressure displacement after anesthetic motor block and tibial nerve neurotomy in spastic equinovarus foot.

    PubMed

    Khalil, Nathalie; Chauvière, Claudie; Le Chapelain, Loïc; Guesdon, Hélène; Speyer, Elodie; Bouaziz, Hervé; Mainard, Didier; Beis, Jean-Marie; Paysant, Jean

    2016-01-01

    The aim of this study was to analyze the displacements of center of pressure (COP) using an in-shoe recording system (F-Scan) before and after motor nerve block and neurotomy of the tibial nerve in spastic equinovarus foot. Thirty-nine patients (age 45 ± 15 yr) underwent a motor nerve block; 16 (age 38 ± 15.2 yr) had tibial neurotomy, combined with tendinous surgery (n = 9). The displacement of the COP (anteroposterior [AP], lateral deviation [LD], posterior margin [PM]) was compared between paretic and nonparetic limbs before and after block and surgery. At baseline, the nonparetic limb had a higher AP (17.3 vs 12.3 cm, p < 0.001) and LD (4.0 vs 3.3 cm, p = 0.001) and a smaller PM (2.9 vs 4.7 cm, p = 0.001). For the paretic limb, a significant increase of AP was observed after block (13.5 vs 12.3 cm, p = 0.02) and after surgery (13.7 vs 12.3 cm, p = 0.03). A significant decrease of PM was observed after surgery (4.5 vs 3.3 cm, p < 0.001) with no more difference between two limbs (2.8 vs 3.3 cm; p = 0.44). This study shows that the F-Scan system can be used to quantify impairments and be useful to evaluate the effects of treatment for spastic foot. It suggests that changes in AP displacement following block may predict the effects of neurotomy.

  10. Schwann cells transduced with a lentiviral vector encoding Fgf-2 promote motor neuron regeneration following sciatic nerve injury.

    PubMed

    Allodi, Ilary; Mecollari, Vasil; González-Pérez, Francisco; Eggers, Ruben; Hoyng, Stefan; Verhaagen, Joost; Navarro, Xavier; Udina, Esther

    2014-10-01

    Fibroblast growth factor 2 (FGF-2) is a trophic factor expressed by glial cells and different neuronal populations. Addition of FGF-2 to spinal cord and dorsal root ganglia (DRG) explants demonstrated that FGF-2 specifically increases motor neuron axonal growth. To further explore the potential capability of FGF-2 to promote axon regeneration, we produced a lentiviral vector (LV) to overexpress FGF-2 (LV-FGF2) in the injured rat peripheral nerve. Cultured Schwann cells transduced with FGF-2 and added to collagen matrix embedding spinal cord or DRG explants significantly increased motor but not sensory neurite outgrowth. LV-FGF2 was as effective as direct addition of the trophic factor to promote motor axon growth in vitro. Direct injection of LV-FGF2 into the rat sciatic nerve resulted in increased expression of FGF-2, which was localized in the basal lamina of Schwann cells. To investigate the in vivo effect of FGF-2 overexpression on axonal regeneration after nerve injury, Schwann cells transduced with LV-FGF2 were grafted in a silicone tube used to repair the resected rat sciatic nerve. Electrophysiological tests conducted for up to 2 months after injury revealed accelerated and more marked reinnervation of hindlimb muscles in the animals treated with LV-FGF2, with an increase in the number of motor and sensory neurons that reached the distal tibial nerve at the end of follow-up. © 2014 Wiley Periodicals, Inc.

  11. Aspects of static and dynamic motor function in peripheral nerve regeneration: SSI and CatWalk gait analysis.

    PubMed

    Bozkurt, A; Scheffel, J; Brook, G A; Joosten, E A; Suschek, C V; O'Dey, D M; Pallua, N; Deumens, R

    2011-05-16

    Assessment of the therapeutic potential of interventions to bridge-repair peripheral nerve defects heavily relies on the demonstration of improved functional outcome. In the present study we used CatWalk gait analysis (locomotor-test) and Static Sciatic Index (SSI) (static-toe-spread-test) to assess the behavioural benefits of autologous nerve transplantation (ANT) repair of 2-cm rat sciatic nerve defects (neurotmesis-lesion). A reproducible and standardised rat sciatic nerve crush lesion model (axonotmesis-lesion) was used to assess the extent of recovery supported by maximal axon regeneration (measured by SSI and CatWalk). Animals were behaviourally followed for a period of 10 weeks. SSI analysis showed that ANT induced a significant improvement in motor deficit from about -95 to -65, however, CatWalk analysis did not show any major indication of locomotor recovery. This discrepancy might suggest that improvements in static motor functions (such as toe spreading) could reflect an early indicator for the recovery of function. We also noted differences in axon regeneration including increased axon density, smaller axon diameters and thinner myelin sheaths in the distal region of the ANT in comparison to the equivalent region of crushed and normal nerves. This difference in axon regeneration may be related to the clearly improved toe spreading function. We conclude that SSI and CatWalk present different advantages and disadvantages for the assessment of motor recovery after bridge-repair of peripheral nerve defects.

  12. Diagnostic biopsy of the pronator teres and a motor branch of the median nerve: indications and technique.

    PubMed

    Dy, Christopher J; Lange, Dale J; Jones, Kristofer J; Garg, Rohit; DiCarlo, Edward F; Wolfe, Scott W

    2012-12-01

    Biopsy of muscle tissue and motor nerve is helpful in the neurological evaluation of patients who present with upper limb and/or diffuse motor weakness. The procedure is indicated to supplement clinical, serological, and imaging diagnostic work-up of myopathic and neuropathic disorders. We describe a surgical technique and clinical series of biopsy of the pronator teres muscle and a motor branch of the median nerve. We performed a retrospective review of 20 patients who underwent biopsy of the pronator teres and a motor branch of the median nerve as part of a clinical, serological, and radiographic evaluation for weakness of the upper extremity. All of the biopsies were performed by a single surgeon. The surgical technique is described. Follow-up visits with both the surgeon and the neurologist were reviewed to evaluate preoperative and postoperative neurological function to identify any changes in nerve or muscle function and any postoperative complications. Biopsied tissue was sufficient for pathological diagnosis in all 20 patients. Diagnoses included multifocal motor neuropathy in 14 patients, amyotrophic lateral sclerosis in 3 patients (2 sporadic; 1 familial), inclusion body myositis (1 patient), inflammatory myopathy (1 patient), and chronic inflammatory demyelinating polyneuropathy (1 patient). At a mean follow-up of 11 weeks (range, 5-31 wk), there were 6 minor surgical complications, all of which were superficial hematomas that resolved with use of a compressive wrap. Biopsy of the pronator teres and a motor branch of the median nerve was safe and effective. The technique is particularly useful when considering the diagnosis of multifocal motor neuropathy affecting the upper extremity. Copyright © 2012 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  13. A Preclinical Study of Laryngeal Motor-Evoked Potentials as a Marker Vagus Nerve Activation.

    PubMed

    Grimonprez, Annelies; Raedt, Robrecht; De Taeye, Leen; Larsen, Lars Emil; Delbeke, Jean; Boon, Paul; Vonck, Kristl

    2015-12-01

    Vagus nerve stimulation (VNS) is a treatment for refractory epilepsy and depression. Previous studies using invasive recording electrodes showed that VNS induces laryngeal motor-evoked potentials (LMEPs) through the co-activation of the recurrent laryngeal nerve and subsequent contractions of the laryngeal muscles. The present study investigates the feasibility of recording LMEPs in chronically VNS-implanted rats, using a minimally-invasive technique, to assess effective current delivery to the nerve and to determine optimal VNS output currents for vagal fiber activation. Three weeks after VNS electrode implantation, signals were recorded using an electromyography (EMG) electrode in the proximity of the laryngeal muscles and a reference electrode on the skull. The VNS output current was gradually ramped up from 0.1 to 1.0 mA in 0.1 mA steps. In 13/27 rats, typical LMEPs were recorded at low VNS output currents (median 0.3 mA, IQR 0.2-0.3 mA). In 11/27 rats, significantly higher output currents were required to evoke electrophysiological responses (median 0.7 mA, IQR 0.5-0.7 mA, p < 0.001). The latencies of these responses deviated significantly from LMEPs (p < 0.05). In 3/27 rats, no electrophysiological responses to simulation were recorded. Minimally invasive LMEP recordings are feasible to assess effective current delivery to the vagus nerve. Furthermore, our results suggest that low output currents are sufficient to activate vagal fibers.

  14. Intraoperative nerve action and compound motor action potential recordings in patients with obstetric brachial plexus lesions.

    PubMed

    Pondaag, Willem; van der Veken, Lieven P A J; van Someren, Paul J; van Dijk, J Gert; Malessy, Martijn J A

    2008-11-01

    A typical finding in supraclavicular exploration of infants with severe obstetric brachial plexus lesions (OBPLs) is a neuroma-in-continuity with the superior trunk and/or a root avulsion at C-5, C-6, or C-7. The operative strategy in these cases is determined by the intraoperative assessment of the severity of the lesion. Intraoperative nerve action potential (NAP) and evoked compound motor action potential (CMAP) recordings have been shown to be helpful diagnostic tools in adults, whereas their value in the intraoperative assessment of infants with OBPLs remains to be determined. Intraoperative NAPs and CMAPs were systematically recorded from damaged and normal nerves of the upper brachial plexus in a consecutive series of 95 infants (mean age 175 days) with OBPLs. A total of 599 intraoperative NAP and 836 CMAP recordings were analyzed. The severity of the nerve lesions was graded as normal, axonotmesis, neurotmesis, or root avulsion, based on surgical, clinical, histological, and radiographic criteria. The correlation of NAP and CMAP recordings with the severity of the lesion was assessed. The specificity of an absent NAP or CMAP to predict a severe lesion (neurotmesis or avulsion) was > 0.9. However, the sensitivity of an absent NAP or CMAP for predicting a severe lesion was low (typically < 0.3). The severity of the nerve lesion was related to CMAP and NAP amplitudes. Cutoff points useful for intraoperative decision making could not be found to differentiate between lesion types in individual patients. Intraoperative NAP and CMAP recordings do not assist in decision making in the surgical treatment of infants with OBPLs. The authors' findings in infants cannot be generalized to adults.

  15. Magnesium administration provokes motor unit survival, after sciatic nerve injury in neonatal rats

    PubMed Central

    Gougoulias, N; Hatzisotiriou, A; Kapoukranidou, D; Albani, M

    2004-01-01

    Background We examined the time course of the functional alterations in two types of muscles following sciatic nerve crush in neonatal rats and the neuroprotective effect of Mg2+. Methods The nerve crush was performed on the 2nd postnatal day. MgSO4*7H2O was administered daily for two weeks. Animals were examined for the contractile properties and for the number of motor units of extensor digitorum longus and soleus muscles at three postnatal stages and adulthood. Four experimental groups were included in this study: i) controls, ii) axotomized rats, iii) magnesium treated controls and iv) axotomized and Mg2+-treated rats. Results Axotomy resulted in 20% MU survival in EDL and 50% in soleus. In contrast, magnesium treatment resulted in a significant motor unit survival (40% survival in EDL and 80% in soleus). The neuroprotective effects of Mg2+ were evident immediately after the Mg2+-treatment. Immature EDL and soleus muscles were slow and fatigueable. Soleus gradually became fatigue resistant, whereas, after axotomy, soleus remained fatigueable up to adulthood. EDL gradually became fastcontracting. Tetanic contraction in axotomized EDL was just 3,3% of the control side, compared to 15,2% in Mg2+-treated adult rats. The same parameter for axotomized soleus was 12% compared to 97% in Mg2+-treated adult rats. Conclusions These results demonstrate that motoneuron death occurs mostly within two weeks of axotomy. Magnesium administration rescues motoneurons and increases the number of motor units surviving into adulthood. Fast and slow muscles respond differently to axotomy and to subsequent Mg2+ treatment in vivo. PMID:15447790

  16. MRI abnormalities of peripheral nerve and muscle are common in amyotrophic lateral sclerosis and share features with multifocal motor neuropathy

    PubMed Central

    Staff, Nathan P.; Amrami, Kimberly K.; Howe, Benjamin M.

    2015-01-01

    Introduction MRI of peripheral nerve and muscle in patients with ALS may be performed to investigate alternative diagnoses including multifocal motor neuropathy (MMN). MRI findings of peripheral nerve and muscle are not well described in these conditions, making interpretation of results difficult. Methods We examined systematically the peripheral nerve and muscle MRI findings in patients with ALS (n=60) and MMN (n=8). Results In patients with ALS and MMN, abnormal MRIs were common (85% and 75%, respectively) but did not correlate with disease severity. Peripheral nerve MRI abnormalities were similar in frequency (ALS: 58% vs. MMN: 63%) with most changes being of mild-to-moderate severity. Muscle MRI changes were more common in ALS (57% vs. 33%), and no muscle atrophy was seen in patients with MMN. Discussion MRI abnormalities of peripheral nerve and muscle in ALS and MMN are common and share some features. PMID:25736373

  17. Effects of Valproic Acid on Axonal Regeneration and Recovery of Motor Function after Peripheral Nerve Injury in the Rat

    PubMed Central

    Rao, Ting; Wu, Fei; Xing, Danmou; Peng, Zhengren; Ren, Dong; Feng, Wei; Chen, Yan; Zhao, Zhiming; Wang, Huan; Wang, Junweng; Kan, Wusheng; Zhang, Qingsong

    2014-01-01

    Background: Valproic acid (VPA) is used to be an effective anti-epileptic drug and mood stabilizer. It has recently been demonstrated that VPA could promote neurite outgrowth, activate the extracellular signal regulated kinase pathway, and increases bcl-2 and growth cone-associated protein 43 levels in spinal cord. In the present research we demonstrate the effect of VPA on peripheral nerve regeneration and recovery of motor function following sciatic nerve transaction in rats. Methods: The rats in VPA group and control group were administered with valproic acid (300mg/kg) and sodium chloride respectively after operation. Each animal was observed sciatic nerve index (SFI) at 2-week intervals and studied electrophysiology at 4-week intervals for 12 weeks. Histological and morphometrical analyses were performed 12 weeks after operation. Using the digital image-analysis system, thickness of the myelin sheath was measured, and total numbers of regenerated axons were counted. Results: There was a significant difference in SFI, electrophysiological index (motor-nerve conduct velocity), and morphometrical results (regenerated axon number and thickness of myelin sheath) in nerve regeneration between the VPA group and controls (P<0.05). Conclusions: The results demonstrated that VPA is able to enhance sciatic nerve regeneration in rats, suggesting the potential clinical application of VPA for the treatment of peripheral nerve injury in humans. PMID:25207308

  18. Heightened motor and sensory (mirror-touch) referral induced by nerve block or topical anesthetic.

    PubMed

    Case, Laura K; Gosavi, Radhika; Ramachandran, Vilayanur S

    2013-08-01

    Mirror neurons allow us to covertly simulate the sensation and movement of others. If mirror neurons are sensory and motor neurons, why do we not actually feel this simulation- like "mirror-touch synesthetes"? Might afferent sensation normally inhibit mirror representations from reaching consciousness? We and others have reported heightened sensory referral to phantom limbs and temporarily anesthetized arms. These patients, however, had experienced illness or injury of the deafferented limb. In the current study we observe heightened sensory and motor referral to the face after unilateral nerve block for routine dental procedures. We also obtain double-blind, quantitative evidence of heightened sensory referral in healthy participants completing a mirror-touch confusion task after topical anesthetic cream is applied. We suggest that sensory and motor feedback exist in dynamic equilibrium with mirror representations; as feedback is reduced, the brain draws more upon visual information to determine- perhaps in a Bayesian manner- what to feel. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Preliminary study on the lesion location and prognosis of cubital tunnel syndrome by motor nerve conduction studies.

    PubMed

    Liu, Zhu; Jia, Zhi-Rong; Wang, Ting-Ting; Shi, Xin; Liang, Wei

    2015-05-05

    To study lesions' location and prognosis of cubital tunnel syndrome (CubTS) by routine motor nerve conduction studies (MNCSs) and short-segment nerve conduction studies (SSNCSs, inching test). Thirty healthy subjects were included and 60 ulnar nerves were studied by inching studies for normal values. Sixty-six patients who diagnosed CubTS clinically were performed bilaterally by routine MNCSs and SSNCSs. Follow-up for 1-year, the information of brief complaints, clinical symptoms, and physical examination were collected. Sixty-six patients were included, 88 of nerves was abnormal by MNCS, while 105 was abnormal by the inching studies. Medial epicondyle to 2 cm above medial epicondyle is the most common segment to be detected abnormally (59.09%), P < 0.01. Twenty-two patients were followed-up, 17 patients' symptoms were improved. Most of the patients were treated with drugs and modification of bad habits. (1) SSNCSs can detect lesions of compressive neuropathy in CubTS more precisely than the routine motor conduction studies. (2) SSNCSs can diagnose CubTS more sensitively than routine motor conduction studies. (3) In this study, we found that medial epicondyle to 2 cm above the medial epicondyle is the most vulnerable place that the ulnar nerve compressed. (4) The patients had a better prognosis who were abnormal in motor nerve conduction time only, but not amplitude in compressed lesions than those who were abnormal both in velocity and amplitude. Our study suggests that SSNCSs is a practical method in detecting ulnar nerve compressed neuropathy, and sensitive in diagnosing CubTS. The compound muscle action potentials by SSNCSs may predict prognosis of CubTS.

  20. Preliminary Study on the Lesion Location and Prognosis of Cubital Tunnel Syndrome by Motor Nerve Conduction Studies

    PubMed Central

    Liu, Zhu; Jia, Zhi-Rong; Wang, Ting-Ting; Shi, Xin; Liang, Wei

    2015-01-01

    Background: To study lesions’ location and prognosis of cubital tunnel syndrome (CubTS) by routine motor nerve conduction studies (MNCSs) and short-segment nerve conduction studies (SSNCSs, inching test). Methods: Thirty healthy subjects were included and 60 ulnar nerves were studied by inching studies for normal values. Sixty-six patients who diagnosed CubTS clinically were performed bilaterally by routine MNCSs and SSNCSs. Follow-up for 1-year, the information of brief complaints, clinical symptoms, and physical examination were collected. Results: Sixty-six patients were included, 88 of nerves was abnormal by MNCS, while 105 was abnormal by the inching studies. Medial epicondyle to 2 cm above medial epicondyle is the most common segment to be detected abnormally (59.09%), P < 0.01. Twenty-two patients were followed-up, 17 patients’ symptoms were improved. Most of the patients were treated with drugs and modification of bad habits. Conclusions: (1) SSNCSs can detect lesions of compressive neuropathy in CubTS more precisely than the routine motor conduction studies. (2) SSNCSs can diagnose CubTS more sensitively than routine motor conduction studies. (3) In this study, we found that medial epicondyle to 2 cm above the medial epicondyle is the most vulnerable place that the ulnar nerve compressed. (4) The patients had a better prognosis who were abnormal in motor nerve conduction time only, but not amplitude in compressed lesions than those who were abnormal both in velocity and amplitude. Our study suggests that SSNCSs is a practical method in detecting ulnar nerve compressed neuropathy, and sensitive in diagnosing CubTS. The compound muscle action potentials by SSNCSs may predict prognosis of CubTS. PMID:25947398

  1. Reliability and Associated Risk Factors for Performance on the Vestibular/Ocular Motor Screening (VOMS) Tool in Healthy Collegiate Athletes.

    PubMed

    Kontos, Anthony P; Sufrinko, Alicia; Elbin, R J; Puskar, Alicia; Collins, Michael W

    2016-06-01

    The Vestibular/Ocular Motor Screening (VOMS) is a newly developed screening tool that evaluates vestibular and ocular motor symptom (eg, headache, dizziness, nausea, fogginess) provocation after a sport-related concussion. Baseline data on the VOMS are needed to extend the application of this measure to broad age groups and to document normal variations in performance. The primary purpose of this study was to examine the internal consistency of the VOMS in a large sample of healthy, nonconcussed collegiate athletes. The secondary purpose was to investigate the effects of patient sex and history of motion sickness, migraines, and concussions on baseline VOMS scores. Cohort study; Level of evidence, 2. A total of 263 National Collegiate Athletic Association Division I athletes (mean ± SD age, 19.85 ± 1.35 years) completed self-reported demographic and medical history at preseason physical examinations and baseline screening. Internal consistency of the VOMS was assessed with Cronbach α. A series of univariate nonparametric tests (χ(2) with odds ratios [ORs] and 95% CIs) were used to examine the associations among medical history risk factors and VOMS clinical cutoff scores (score of ≥2 for any individual VOMS symptom, near point of convergence [NPC] distance of ≥5 cm), with higher scores representing greater symptom provocation. Internal consistency of the VOMS was high (Cronbach α = .97), and 89% of athletes scored below cutoff levels (ie, 11% false-positive rate). Female athletes (OR, 2.99 [95% CI, 1.34-6.70]; P = .006) and those with a personal history of motion sickness (OR, 7.73 [95% CI, 1.94-30.75]; P = .009) were more likely to have ≥1 VOMS scores above cutoff levels. No risk factors were associated with increased odds of an abnormal NPC distance. The VOMS possesses internal consistency and an acceptable false-positive rate among healthy Division I collegiate student-athletes. Female sex and a history of motion sickness were risk factors for VOMS

  2. Hindlimb spasticity after unilateral motor cortex lesion in rats is reduced by contralateral nerve root transfer

    PubMed Central

    Zong, Haiyang; Ma, Fenfen; Zhang, Laiyin; Lu, Huiping; Gong, Jingru; Cai, Min; Lin, Haodong; Zhu, Yizhun; Hou, Chunlin

    2016-01-01

    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). Hmax (H-wave maximum amplitude)/Mmax (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

  3. The reflex effects of nonnoxious sural nerve stimulation on human triceps surae motor neurons.

    PubMed

    Kukulka, C G

    1994-05-01

    1. The effects of low-intensity electrical stimulation of the ipsilateral sural nerve on the reflex response of human triceps surae motor neurons were examined in 169 motor units recorded in 11 adult volunteers: 69 units from soleus (SOL), 48 units from lateral gastrocnemius (LG), and 52 units from medial gastrocnemius (MG). The reflex effects were assessed by the peristimulus time histogram (PSTH) technique, categorized according to onset latencies, and the magnitudes of effects were calculated as percent changes in baseline firing rates. 2. Sural stimulation evoked complex changes in motor-unit firing at onset latencies between 28 and 140 ms. The two most common responses seen in all muscles were a short-latency depression (D1) in firing (mean onset latency = 40 ms) in 42% of all units studied and a secondary enhancement (E2) in firing (mean onset latency = 72 ms) in 43% of all units. In LG, the D1 effect represented a mean decrease in firing of 52% which was statistically different from the changes in MG (42% decrease) and SOL (38% decrease). The magnitudes of E2 effects were similar across muscles with an average of 47% increase in firing. 3. No differences were found in the frequencies of occurrence for the enhancements in firing among the muscles studied. The main difference in reflex responses was the occurrence of an intermediate latency depression (D2) in 27% of the LG units with a mean onset latency of 72 ms. 4. Based on estimates of conduction times for activation of low-threshold cutaneous afferents, the short-latency D1 response likely represents an oligosynaptic spinal reflex with transmission times similar to the Ia reciprocal inhibitory pathway. These findings raise the question as to the possibility of low-threshold cutaneous afferents sharing common interneurons with low-threshold muscle afferent reflexes that have identical onset latencies. The complex reflex effects associated with low-level stimulation of a cutaneous nerve indicate a rich

  4. Interaction of /sup 125/I-labeled botulinum neurotoxins with nerve terminals. II. Autoradiographic evidence for its uptake into motor nerves by acceptor-mediated endocytosis

    SciTech Connect

    Black, J.D.; Dolly, J.O.

    1986-01-01

    Using pharmacological and autoradiographic techniques it has been shown that botulinum neurotoxin (BoNT) is translocated across the motor nerve terminal membrane to reach a postulated intraterminal target. In the present study, the nature of this uptake process was investigated using electron microscopic autoradiography. It was found that internalization is acceptor-mediated and that binding to specific cell surface acceptors involves the heavier chain of the toxin. In addition, uptake was shown to be energy and temperature-dependent and to be accelerated by nerve stimulation, a treatment which also shortens the time course of the toxin-induced neuroparalysis. These results, together with the observation that silver grains were often associated with endocytic structures within the nerve terminal, suggested that acceptor-mediated endocytosis is responsible for toxin uptake. Possible recycling of BoNT acceptors (an important aspect of acceptor-mediated endocytosis of toxins) at motor nerve terminals was indicated by comparing the extent of labeling in the presence and absence of metabolic inhibitors. On the basis of these collective results, it is concluded that BoNT is internalized by acceptor-mediated endocytosis and, hence, the data support the proposal that this toxin inhibits release of acetylcholine by interaction with an intracellular target.

  5. [Investigation of maximal motor nerve conductivity and distal latency before and after galvanic cell bath (author's transl)].

    PubMed

    Trnavsky, G

    1982-04-30

    Measurements about maximal motor nerve conductivity of ulnaris and medianus were carried out before and after constant galvanisation from neck to hand. Significant results of conductivity, distal latency and amplitude of summation potential could not be registered neither by plus nor by minus pole at the hand.

  6. Phrenic nerve conduction and diaphragmatic motor evoked potentials: evaluation of respiratory dysfunction.

    PubMed

    Lu, Z; Tang, X; Huang, X

    1998-06-01

    To investigate preliminarily the value of phrenic nerve conduction (PNC) and diaphragmatic motor evoked potentials (MEPs) in the evaluation of various respiratory dysfunction (RDF). Thirty-four patients with various RDF, (19 patients with neurogenical diseases and 15 patients with respiratory disorders) were investigated. Fifty healthy volunteers served as controls. The phrenic nerve was cutaneously stimulated by electrical pulse current at the midpoint of the posterior border of the sternomastoid muscle, and the diaphragmatic muscle compound action potentials (DCAP) were recorded between the 7th and 8th intercostal space and xiphoid process. When the magnetic transcranial stimulation (MTS) of the cortex was given, the recordings were made under the condition of maximal deep inspiration. All patients with myopathies had normal PNC. The patients with Guillain Barre syndrome (GBS), hereditary motor and sensory neuropathy (HMSN) and myasthenic crisis had abnormal PNC. The findings in PNC studies remarkably correlated with RDF, while serial examinations were performed in the patients with GBS and myasthenia gravis (MG). In 7 patients with sleep apnea syndrome (SAS), 4 had abnormal PNC, and 2 of 3 patients with chronic obstructive pulmonary diseases (COPD), and 1 of 5 patients with chest tightness or breathlessness on the supine position showed decreased amplitude. When MEPs were recorded, 3 of 5 patients showed abnormal SAS (1 had no response, 2 lower amplitude). Three patients with COPD had normal MEP. PNC studies could not only evaluate neuromuscular RDF and predict the outcome of diseases, but also supply additional information about diaphragmatic dysfunction for the RDF caused by respiratory disorders. The results of PNC and diaphragmatic MEP may differentiate the types of SAS.

  7. Calmodulin increases transmitter release by mobilizing quanta at the frog motor nerve terminal.

    PubMed

    Brailoiu, Eugen; Miyamoto, Michael D; Dun, Nae J

    2002-11-01

    The role of calmodulin (CaM) in transmitter release was investigated using liposomes to deliver CaM and monoclonal antibodies against CaM (antiCaM) directly into the frog motor nerve terminal. Miniature endplate potentials (MEPPs) were recorded in a high K+ solution, and effects on transmitter release were monitored using estimates of the quantal release parameters m (number of quanta released), n (number of functional transmitter release sites), p (mean probability of release), and var(s) p (spatial variance in p). Administration of CaM, but not heat-inactivated CaM, encapsulated in liposomes (1000 units ml(-1)) produced an increase in m (25%) that was due to an increase in n. MEPP amplitude was not altered by CaM. Administration of antiCaM, but not heat-inactivated antiCaM, in liposomes (50 microl ml(-1)) produced a progressive decrease in m (40%) that was associated with decreases in n and p. MEPP amplitude was decreased (15%) after a 25 min lag time, suggesting a separation in time between the decreases in quantal release and quantal size. Bath application of the membrane-permeable CaM antagonist W7 (28 microM) produced a gradual decrease in m (25%) that was associated with a decrease in n. W7 also produced a decrease in MEPP amplitude that paralleled the decrease in m. The decreases in MEPP size and m produced by W7 were both reversed by addition of CaM. Our results suggest that CaM increases transmitter release by mobilizing synaptic vesicles at the frog motor nerve terminal.

  8. [From the abducens nucleus to spatial memory: an ocular motor journey].

    PubMed

    Pierrot-Deseilligny, C

    2005-05-01

    Advances in our knowledge on eye movements over the last 25 years are reviewed, focusing on the author's experience. First, the advantages of binocular frontal vision, which is a common characteristic of all predator mammals, are compared to those of lateral vision, characterizing their preys. Binocular frontal vision implies a perfect parallelism of both eyes, which is ensured in the pons by means of the abducens nucleus, controlling abduction as well as adduction. The pathological example of the "one-and-a-half" syndrome, in which the abducens nucleus and the adjacent medial longitudinal fasciculus are simultaneously impaired, is described. The main brainstem syndromes involving vertical eye movements are also reviewed: in particular, the third nerve nucleus syndrome, in which both ipsilateral third nerve paralysis and contralateral superior rectus paralysis (with hypotropia) result from a unilateral third nerve nucleus lesion. A case of upbeat nystagmus (in the primary position of gaze) due to a small upper pontine lesion, probably affecting the ventral tegmental tract (VTT) is also reported. This is an opportunity to emphasize that, although a number of cases of upbeat nystagmus due to focal brainstem lesions affecting the upward vestibular pathway (UVP)--either at the upper pontine (VTT) or caudal medullary level--exist in the literature, no convincing cases with downbeat nystagmus (in the primary position of gaze) due to a focal brainstem lesion have been reported. Downbeat nystagmus could result from a UVP hyperactivity (secondary to a floccular lesion) and the notion that this pathway is physiologically predominant compared to the downward pathway, maybe due to gravity, is developed. A new hypothesis about the role of the caudal medulla in UVP is also proposed. Next, the cortical control of saccadic eye movements is reviewed, with a reminder that reflexive saccades are mainly triggered by the parietal eye field whereas intentional saccades depend upon the

  9. Fistula in ano surgery has no impact on pudendal nerve terminal motor latency.

    PubMed

    Daniel, Fady; Thomas, Christian; Etienney, Isabelle; Atienza, Patrick

    2006-07-01

    Anal fistula surgery is recognized as a major risk factor for anal incontinence. This incontinence is mainly due to surgical sphincter lesions, although a neurogenic mechanism through damage to the pudendal nerve is not excluded. The objective of our study was to evaluate the influence of anal surgery on the anal terminal motor latency of the pudendal nerve (PNTML). The PNTML values were measured pre- and postoperatively, respectively, in 33 patients (28 men, 5 women) treated for anal suppuration and 34 patients (21 men, 13 women) undergoing pedicular hemorrhoidectomy using the Milligan and Morgan technique. The average age was 49.6 years in the hemorrhoid group and 45 years in the fistula group (p=0.19). There was no difference in the sex ratio between the two groups (p=0.06). In the anal fistula group, the preoperative mean PNTML was 2.42 (+/-0.46) ms on the infected side and 2.40 (+/-0.42) ms on the healthy side, with a significant difference from the control group's preoperative ipsilateral latencies: 2.73 (+/-0.60) ms (p=0.02, p=0.01). The variations in the postoperative PNTML of the fistula group, both on the healthy side (DeltaPNTML=0.06+/-0.42 ms) and on the diseased side (DeltaPNTML=0.03+/-0.40 ms), are comparable with those of the hemorrhoid group (DeltaPNTML=0.01+/-0.48 ms; p=0.63, p=0.84). The nervous conduction of the pudendal nerves does not seem to be altered by the presence of an infectious process in the ischiorectal fossa nor by the surgical procedure. However, a more refined electrophysiological study would seem to be necessary to assess the repercussions on the perineal innervation.

  10. Branching pattern of the motor nerve endings in a skeletal muscle of the adult rat.

    PubMed Central

    Tomas, J; Fenoll, R; Mayayo, E; Santafé, M

    1990-01-01

    We have performed a morphometric analysis of the branching pattern of the rat sternomastoid motor nerve terminals in normal and regenerated singly-innervated synaptic areas, in junctions with an accessory ending and also in dually-innervated synaptic areas. We tried to seek measurable differences related to the terminal complexity and size in these different situations. The number of sole-plate nuclei is always significantly correlated with the nerve terminal parameters and unrelated to the muscle cell diameter. A significant correlation between the terminal complexity and the postsynaptic size is found only in the smallest endings whereas correlation is lost with the increase in nerve terminal complexity. In normal singly-innervated areas, the mean length of the distal free-end segments of the terminal arborisation becomes reduced with the increase in complexity of the terminals, whereas the mean length of the segments between branching points and the mean angle of branch emergence is, on average, constant. Whereas the accessory endings show the same branching pattern as the endings during the initial days of regeneration, the parent ending can be considered as a miniature version of the endings in normal singly-innervated junctions. In dually-innervated areas, the smallest endings show a similar branching pattern to the accessory endings and the endings during the initial process of reinnervation, whereas the larger endings show a significant reduction in the length of the distally placed segments compared to the normal endings in singly-innervated areas. Results indicate that the terminal branching pattern is not haphazard but, on the contrary, general rules and tendencies can be measured. PMID:2323988

  11. The effect of loco-regional anaesthesia on motor activity induced by direct stimulation of the sciatic nerve in dogs.

    PubMed

    Murdoch, A P; Michou, J N

    2016-03-01

    A prospective, randomised, blinded, case-controlled clinical study was designed using client-owned dogs undergoing unilateral pelvic limb orthopaedic surgery, to determine the effect on induced motor activity by electrical stimulation of the sciatic nerve distal to the site of local anaesthetic administration. Dogs were administered 0.5% bupivacaine either extradurally or via a femoral and transgluteal sciatic electrolocation-guided nerve block prior to pelvic limb surgery. Motor response to electrical stimulation of branches of the sciatic nerve was tested and the minimum current required to induce muscle twitch was recorded prior to bupivacaine administration. Provided sensory blockade had been deemed successful intraoperatively, testing was repeated postoperatively, with each dog acting as its own control. Paired t-tests were performed to compare pre- and postoperative minimum currents. Eleven dogs administered extradural and 11 dogs administered femoral and sciatic perineural bupivacaine were eligible for post-operative testing. All dogs displayed normal motor response to electrical stimulation of the sciatic nerve at both sites tested before and after bupivacaine administration. There was no significant difference in the minimum current required to induce muscle twitch between pre- and post-operative testing (P = 0.31 sciatic site, P = 0.36 peroneal site), nor between the two groups using different loco-regional anaesthetic techniques (minimum P = 0.13). This study shows that stimulation of the sciatic nerve distal to the site of bupivacaine administration induces motor activity, despite adequate sensory blockade. This is relevant in surgical cases where mechanical stimulation of the sciatic nerve might be expected and needs to be recognised to avoid postoperative neurapraxia.

  12. PlexinA3 restricts spinal exit points and branching of trunk motor nerves in embryonic zebrafish.

    PubMed

    Feldner, Julia; Reimer, Michell M; Schweitzer, Jörn; Wendik, Björn; Meyer, Dirk; Becker, Thomas; Becker, Catherina G

    2007-05-02

    The pioneering primary motor axons in the zebrafish trunk are guided by multiple cues along their pathways. Plexins are receptor components for semaphorins that influence motor axon growth and path finding. We cloned plexinA3 in zebrafish and localized plexinA3 mRNA in primary motor neurons during axon outgrowth. Antisense morpholino knock-down led to substantial errors in motor axon growth. Errors comprised aberrant branching of primary motor nerves as well as additional exit points of axons from the spinal cord. Excessively branched and supernumerary nerves were found in both ventral and dorsal pathways of motor axons. The trunk environment and several other types of axons, including trigeminal axons, were not detectably affected by plexinA3 knock-down. RNA overexpression rescued all morpholino effects. Synergistic effects of combined morpholino injections indicate interactions of plexinA3 with semaphorin3A homologs. Thus, plexinA3 is a crucial receptor for axon guidance cues in primary motor neurons.

  13. Development of Vestibular Stochastic Resonance as a Sensorimotor Countermeasure: Improving Otolith Ocular and Motor Task Responses

    NASA Technical Reports Server (NTRS)

    Mulavara, Ajitkumar; Fiedler, Matthew; DeDios,Yiri E.; Galvan, Raquel; Bloomberg, Jacob; Wood, Scott

    2011-01-01

    Astronauts experience disturbances in sensorimotor function after spaceflight during the initial introduction to a gravitational environment, especially after long-duration missions. Stochastic resonance (SR) is a mechanism by which noise can assist and enhance the response of neural systems to relevant, imperceptible sensory signals. We have previously shown that imperceptible electrical stimulation of the vestibular system enhances balance performance while standing on an unstable surface. The goal of our present study is to develop a countermeasure based on vestibular SR that could improve central interpretation of vestibular input and improve motor task responses to mitigate associated risks.

  14. Ocular motor responses to abrupt interaural head translation in normal humans

    NASA Technical Reports Server (NTRS)

    Ramat, Stefano; Zee, David S.; Shelhamer, M. J. (Principal Investigator)

    2003-01-01

    We characterized the interaural translational vestibulo-ocular reflex (tVOR) in 6 normal humans to brief (approximately 200 ms), high-acceleration (0.4-1.4g) stimuli, while they fixed targets at 15 or 30 cm. The latency was 19 +/- 5 ms at 15-cm and 20 +/- 12 ms at 30-cm viewing. The gain was quantified using the ratio of actual to ideal behavior. The median position gain (at time of peak head velocity) was 0.38 and 0.37, and the median velocity gain, 0.52 and 0.62, at 15- and 30-cm viewing, respectively. These results suggest the tVOR scales proportionally at these viewing distances. Likewise, at both viewing distances, peak eye velocity scaled linearly with peak head velocity and gain was independent of peak head acceleration. A saccade commonly occurred in the compensatory direction, with a greater latency (165 vs. 145 ms) and lesser amplitude (1.8 vs. 3.2 deg) at 30- than 15-cm viewing. Even with saccades, the overall gain at the end of head movement was still considerably undercompensatory (medians 0.68 and 0.77 at 15- and 30-cm viewing). Monocular viewing was also assessed at 15-cm viewing. In 4 of 6 subjects, gains were the same as during binocular viewing and scaled closely with vergence angle. In sum the low tVOR gain and scaling of the response with viewing distance and head velocity extend previous results to higher acceleration stimuli. tVOR latency (approximately 20 ms) was lower than previously reported. Saccades are an integral part of the tVOR, and also scale with viewing distance.

  15. Ocular motor responses to abrupt interaural head translation in normal humans.

    PubMed

    Ramat, Stefano; Zee, David S

    2003-08-01

    We characterized the interaural translational vestibulo-ocular reflex (tVOR) in 6 normal humans to brief (approximately 200 ms), high-acceleration (0.4-1.4g) stimuli, while they fixed targets at 15 or 30 cm. The latency was 19 +/- 5 ms at 15-cm and 20 +/- 12 ms at 30-cm viewing. The gain was quantified using the ratio of actual to ideal behavior. The median position gain (at time of peak head velocity) was 0.38 and 0.37, and the median velocity gain, 0.52 and 0.62, at 15- and 30-cm viewing, respectively. These results suggest the tVOR scales proportionally at these viewing distances. Likewise, at both viewing distances, peak eye velocity scaled linearly with peak head velocity and gain was independent of peak head acceleration. A saccade commonly occurred in the compensatory direction, with a greater latency (165 vs. 145 ms) and lesser amplitude (1.8 vs. 3.2 deg) at 30- than 15-cm viewing. Even with saccades, the overall gain at the end of head movement was still considerably undercompensatory (medians 0.68 and 0.77 at 15- and 30-cm viewing). Monocular viewing was also assessed at 15-cm viewing. In 4 of 6 subjects, gains were the same as during binocular viewing and scaled closely with vergence angle. In sum the low tVOR gain and scaling of the response with viewing distance and head velocity extend previous results to higher acceleration stimuli. tVOR latency (approximately 20 ms) was lower than previously reported. Saccades are an integral part of the tVOR, and also scale with viewing distance.

  16. Ocular motor responses to abrupt interaural head translation in normal humans

    NASA Technical Reports Server (NTRS)

    Ramat, Stefano; Zee, David S.; Shelhamer, M. J. (Principal Investigator)

    2003-01-01

    We characterized the interaural translational vestibulo-ocular reflex (tVOR) in 6 normal humans to brief (approximately 200 ms), high-acceleration (0.4-1.4g) stimuli, while they fixed targets at 15 or 30 cm. The latency was 19 +/- 5 ms at 15-cm and 20 +/- 12 ms at 30-cm viewing. The gain was quantified using the ratio of actual to ideal behavior. The median position gain (at time of peak head velocity) was 0.38 and 0.37, and the median velocity gain, 0.52 and 0.62, at 15- and 30-cm viewing, respectively. These results suggest the tVOR scales proportionally at these viewing distances. Likewise, at both viewing distances, peak eye velocity scaled linearly with peak head velocity and gain was independent of peak head acceleration. A saccade commonly occurred in the compensatory direction, with a greater latency (165 vs. 145 ms) and lesser amplitude (1.8 vs. 3.2 deg) at 30- than 15-cm viewing. Even with saccades, the overall gain at the end of head movement was still considerably undercompensatory (medians 0.68 and 0.77 at 15- and 30-cm viewing). Monocular viewing was also assessed at 15-cm viewing. In 4 of 6 subjects, gains were the same as during binocular viewing and scaled closely with vergence angle. In sum the low tVOR gain and scaling of the response with viewing distance and head velocity extend previous results to higher acceleration stimuli. tVOR latency (approximately 20 ms) was lower than previously reported. Saccades are an integral part of the tVOR, and also scale with viewing distance.

  17. Nerve growth factor preserves a critical motor period in rat striatum.

    PubMed

    Wolansky, M J; Paratcha, G C; Ibarra, G R; Azcurra, J M

    1999-01-01

    We previously found the occurrence of a critical motor period during rat postnatal development where circling training starting the 7-day schedule at 30 days-but not before or after-induces a lifetime drop in the binding to cholinergic muscarinic receptors (mAChRs) in striatum. Here, we studied whether nerve growth factor (NGF) participates in this restricted period of muscarinic sensitivity. For this purpose, we administered mouse salival gland 2.5S NGF (1.4 or 0.4 microg/day, infused by means of ALZA minipumps) by intrastriatal unilateral route between days 25 and 39, and then trained rats starting at 40 days. Under these conditions, NGF induced a long-term reduction in the striatal [3H] quinuclidilbenzylate (QNB) binding sites despite the fact that motor training was carried out beyond the natural critical period. Thus, at day 70, measurement of specific QNB binding in infused striata of trained rats showed decreases of 42% (p < .0004) and 33% (p < .02) after administration of the higher and lower NGF doses, respectively, with respect to trained rats treated with cytochrome C, for control. Noncannulated striata of the NGF-treated rats also showed a decrease in QNB binding sites (44%; p < .0001) only at the higher infusion rate. This effect was not found in the respective control groups. Our observations show that NGF modulates the critical period in which activity-dependent mAChR setting takes place during rat striatal maturation.

  18. Unraveling gene expression profiles in peripheral motor nerve from amyotrophic lateral sclerosis patients: insights into pathogenesis

    PubMed Central

    Riva, Nilo; Clarelli, Ferdinando; Domi, Teuta; Cerri, Federica; Gallia, Francesca; Trimarco, Amelia; Brambilla, Paola; Lunetta, Christian; Lazzerini, Alberto; Lauria, Giuseppe; Taveggia, Carla; Iannaccone, Sandro; Nobile-Orazio, Eduardo; Comi, Giancarlo; D’Antonio, Maurizio; Martinelli-Boneschi, Filippo; Quattrini, Angelo

    2016-01-01

    The aim of the present study is to investigate the molecular pathways underlying amyotrophic lateral sclerosis (ALS) pathogenesis within the peripheral nervous system. We analyzed gene expression changes in human motor nerve diagnostic biopsies obtained from eight ALS patients and seven patients affected by motor neuropathy as controls. An integrated transcriptomics and system biology approach was employed. We identified alterations in the expression of 815 genes, with 529 up-regulated and 286 down-regulated in ALS patients. Up-regulated genes clustered around biological process involving RNA processing and protein metabolisms. We observed a significant enrichment of up-regulated small nucleolar RNA transcripts (p = 2.68*10-11) and genes related to endoplasmic reticulum unfolded protein response and chaperone activity. We found a significant down-regulation in ALS of genes related to the glutamate metabolism. Interestingly, a network analysis highlighted HDAC2, belonging to the histone deacetylase family, as the most interacting node. While so far gene expression studies in human ALS have been performed in postmortem tissues, here specimens were obtained from biopsy at an early phase of the disease, making these results new in the field of ALS research and therefore appealing for gene discovery studies. PMID:27982123

  19. Ciliary neurotrophic factor promotes motor reinnervation of the musculocutaneous nerve in an experimental model of end-to-side neurorrhaphy

    PubMed Central

    2011-01-01

    Background It is difficult to repair nerve if proximal stump is unavailable or autogenous nerve grafts are insufficient for reconstructing extensive nerve damage. Therefore, alternative methods have been developed, including lateral anastomosis based on axons' ability to send out collateral sprouts into denervated nerve. The different capacity of a sensory or motor axon to send a sprout is controversial and may be controlled by cytokines and/or neurotrophic factors like ciliary neurotrophic factor (CNTF). The aim of the present study was to quantitatively assess collateral sprouts sent out by intact motor and sensory axons in the end-to-side neurorrhaphy model following intrathecal administration of CNTF in comparison with phosphate buffered saline (vehiculum) and Cerebrolysin. The distal stump of rat transected musculocutaneous nerve (MCN) was attached in an end-to-side fashion with ulnar nerve. CNTF, Cerebrolysin and vehiculum were administered intrathecally for 2 weeks, and all animals were allowed to survive for 2 months from operation. Numbers of spinal motor and dorsal root ganglia neurons were estimated following their retrograde labeling by Fluoro-Ruby and Fluoro-Emerald applied to ulnar and musculocutaneous nerve, respectively. Reinnervation of biceps brachii muscles was assessed by electromyography, behavioral test, and diameter and myelin sheath thickness of regenerated axons. Results Vehiculum or Cerebrolysin administration resulted in significantly higher numbers of myelinated axons regenerated into the MCN stumps compared with CNTF treatment. By contrast, the mean diameter of the myelinated axons and their myelin sheath thickness in the cases of Cerebrolysin- or CNTF-treated animals were larger than were those for rats treated with vehiculum. CNTF treatment significantly increased the percentage of motoneurons contributing to reinnervation of the MCN stumps (to 17.1%) when compared with vehiculum or Cerebrolysin treatments (at 9.9 or 9

  20. Central command does not decrease cardiac parasympathetic efferent nerve activity during spontaneous fictive motor activity in decerebrate cats.

    PubMed

    Kadowaki, Akito; Matsukawa, Kanji; Wakasugi, Rie; Nakamoto, Tomoko; Liang, Nan

    2011-04-01

    To examine whether withdrawal of cardiac vagal efferent nerve activity (CVNA) predominantly controls the tachycardia at the start of exercise, the responses of CVNA and cardiac sympathetic efferent nerve activity (CSNA) were directly assessed during fictive motor activity that occurred spontaneously in unanesthetized, decerebrate cats. CSNA abruptly increased by 71 ± 12% at the onset of the motor activity, preceding the tachycardia response. The increase in CSNA lasted for 4-5 s and returned to the baseline, even though the motor activity was not ended. The increase of 6 ± 1 beats/min in heart rate appeared with the same time course of the increase in CSNA. In contrast, CVNA never decreased but increased throughout the motor activity, in parallel with a rise in mean arterial blood pressure (MAP). The peak increase in CVNA was 37 ± 9% at 5 s after the motor onset. The rise in MAP gradually developed to 21 ± 2 mmHg and was sustained throughout the spontaneous motor activity. Partial sinoaortic denervation (SAD) blunted the baroreflex sensitivity of the MAP-CSNA and MAP-CVNA relationship to 22-33% of the control. Although partial SAD blunted the initial increase in CSNA to 53% of the control, the increase in CSNA was sustained throughout the motor activity. In contrast, partial SAD almost abolished the increase in CVNA during the motor activity, despite the augmented elevation of 31 ± 1 mmHg in MAP. Because afferent inputs from both muscle receptors and arterial baroreceptors were absent or greatly attenuated in the partial SAD condition, only central command was operating during spontaneous fictive motor activity in decerebrate cats. Therefore, it is likely that central command causes activation of cardiac sympathetic outflow but does not produce withdrawal of cardiac parasympathetic outflow during spontaneous motor activity.

  1. Ocular-motor function and information processing: implications for the reading process.

    PubMed

    Leisman, G; Schwartz, J

    1977-01-01

    This paper discusses the dichotomy between continually moving eyes and the lack of blurred visual experience. A discontinuous model of visual perception is proposed, with the discontinuities being phase and temporally related to saccadic eye movements. It is further proposed that deviant duration and angular velocity characteristics of saccades in patients with hypertonic motor impairment relate to information processing defects. Stabilized retinal image procedures, which control for the effects of eye movements, significantly increase the ability of these patients actively to recall information presented for periods of less than three sec. A model of the reading process is presented based on these findings that addresses itself to the specific components of an interactions between eye movement, information transmission and information processing.

  2. An Evaluation of Automotive Interior Packages Based on Human Ocular and Joint Motor Properties

    NASA Astrophysics Data System (ADS)

    Tanaka, Yoshiyuki; Rakumatsu, Takeshi; Horiue, Masayoshi; Miyazaki, Tooru; Nishikawa, Kazuo; Nouzawa, Takahide; Tsuji, Toshio

    This paper proposes a new evaluation method of an automotive interior package based on human oculomotor and joint-motor properties. Assuming the long-term driving situation in the express high way, the three evaluation indices were designed on i) the ratio of head motion at gazing the driving items; ii) the load torque for maintaining the standard driving posture; and iii) the human force manipulability at the end-point of human extremities. Experiments were carried out for two different interior packages with four subjects who have the special knowledge on the automobile development. Evaluation results demonstrate that the proposed method can quantitatively analyze the driving interior in good agreement with the generally accepted subjective opinion in the automobile industry.

  3. A Small Motor Cortex Lesion Abolished Ocular Dominance Plasticity in the Adult Mouse Primary Visual Cortex and Impaired Experience-Dependent Visual Improvements

    PubMed Central

    Pielecka-Fortuna, Justyna; Kalogeraki, Evgenia; Greifzu, Franziska; Löwel, Siegrid

    2015-01-01

    It was previously shown that a small lesion in the primary somatosensory cortex (S1) prevented both cortical plasticity and sensory learning in the adult mouse visual system: While 3-month-old control mice continued to show ocular dominance (OD) plasticity in their primary visual cortex (V1) after monocular deprivation (MD), age-matched mice with a small photothrombotically induced (PT) stroke lesion in S1, positioned at least 1 mm anterior to the anterior border of V1, no longer expressed OD-plasticity. In addition, in the S1-lesioned mice, neither the experience-dependent increase of the spatial frequency threshold (“visual acuity”) nor of the contrast threshold (“contrast sensitivity”) of the optomotor reflex through the open eye was present. To assess whether these plasticity impairments can also occur if a lesion is placed more distant from V1, we tested the effect of a PT-lesion in the secondary motor cortex (M2). We observed that mice with a small M2-lesion restricted to the superficial cortical layers no longer expressed an OD-shift towards the open eye after 7 days of MD in V1 of the lesioned hemisphere. Consistent with previous findings about the consequences of an S1-lesion, OD-plasticity in V1 of the nonlesioned hemisphere of the M2-lesioned mice was still present. In addition, the experience-dependent improvements of both visual acuity and contrast sensitivity of the open eye were severely reduced. In contrast, sham-lesioned mice displayed both an OD-shift and improvements of visual capabilities of their open eye. To summarize, our data indicate that even a very small lesion restricted to the superficial cortical layers and more than 3mm anterior to the anterior border of V1 compromised V1-plasticity and impaired learning-induced visual improvements in adult mice. Thus both plasticity phenomena cannot only depend on modality-specific and local nerve cell networks but are clearly influenced by long-range interactions even from distant brain

  4. A Small Motor Cortex Lesion Abolished Ocular Dominance Plasticity in the Adult Mouse Primary Visual Cortex and Impaired Experience-Dependent Visual Improvements.

    PubMed

    Pielecka-Fortuna, Justyna; Kalogeraki, Evgenia; Greifzu, Franziska; Löwel, Siegrid

    2015-01-01

    It was previously shown that a small lesion in the primary somatosensory cortex (S1) prevented both cortical plasticity and sensory learning in the adult mouse visual system: While 3-month-old control mice continued to show ocular dominance (OD) plasticity in their primary visual cortex (V1) after monocular deprivation (MD), age-matched mice with a small photothrombotically induced (PT) stroke lesion in S1, positioned at least 1 mm anterior to the anterior border of V1, no longer expressed OD-plasticity. In addition, in the S1-lesioned mice, neither the experience-dependent increase of the spatial frequency threshold ("visual acuity") nor of the contrast threshold ("contrast sensitivity") of the optomotor reflex through the open eye was present. To assess whether these plasticity impairments can also occur if a lesion is placed more distant from V1, we tested the effect of a PT-lesion in the secondary motor cortex (M2). We observed that mice with a small M2-lesion restricted to the superficial cortical layers no longer expressed an OD-shift towards the open eye after 7 days of MD in V1 of the lesioned hemisphere. Consistent with previous findings about the consequences of an S1-lesion, OD-plasticity in V1 of the nonlesioned hemisphere of the M2-lesioned mice was still present. In addition, the experience-dependent improvements of both visual acuity and contrast sensitivity of the open eye were severely reduced. In contrast, sham-lesioned mice displayed both an OD-shift and improvements of visual capabilities of their open eye. To summarize, our data indicate that even a very small lesion restricted to the superficial cortical layers and more than 3mm anterior to the anterior border of V1 compromised V1-plasticity and impaired learning-induced visual improvements in adult mice. Thus both plasticity phenomena cannot only depend on modality-specific and local nerve cell networks but are clearly influenced by long-range interactions even from distant brain regions.

  5. Morphological features of nerve terminal degeneration as part of the remodeling process in the motor endplate in adult muscles.

    PubMed

    Kawabuchi, M; He, J W; Ting, L W; Zhou, C J; Wang, S; Hirata, K

    2000-01-01

    With the exception of signs of retraction and withdrawal, there have been few morphological data concerning degenerated neural profiles in adult motor endplates. Here, investigation into the ultrastructure of the soleus motor endplates of adult rats (4 months old) turned up particular axonal degeneration in approximately 3% of the subjects. These axons occur as synaptic debris in the synaptic matrix of the motor endplate, adjacent to thin processes of the perisynaptic cells occupying the outermost layer of the motor endplate and were devoid of basal lamina. They often possessed dense-cored vesicles (50-80 nm). Axonal debris released from Schwann cell processes occurred during the period of acute sciatic neurectomy, when nerve terminals progressively disrupted within the motor endplate-associated Schwann cells. Finally, immunohistochemical staining for antibodies to label macrophages (ED1 or ED2) has shown that nerve fiber-associated macrophages are located near the motor endplate. The results suggest that during the course of endplate remodeling, a few parts of the terminal branches are disposed of through spontaneous collapse, subsequent release from the Schwann cell investment, and eventual ingestion by macrophages in the perisynaptic space.

  6. The anabolic steroid nandrolone enhances motor and sensory functional recovery in rat median nerve repair with long interpositional nerve grafts.

    PubMed

    Ghizoni, Marcos Flávio; Bertelli, Jayme Augusto; Grala, Carolina Giesel; da Silva, Rosemeri Maurici

    2013-01-01

    Recovery from peripheral nerve repair is frequently incomplete. Hence drugs that enhance nerve regeneration are needed clinically. To study the effects of nandrolone decanoate in a model of deficient reinnervation in the rat. In 40 rats, a 40-mm segment of the left median nerve was removed and interposed between the stumps of a sectioned right median nerve. Starting 7 days after nerve grafting and continuing over a 6-month period, we administered nandrolone at a dose of 5 mg/kg/wk to half the rats (n = 20). All rats were assessed behaviorally for grasp function and nociceptive recovery for up to 6 months. At final assessment, reinnervated muscles were tested electrophysiologically and weighed. Results were compared between rats that had received versus not received nandrolone and versus 20 nongrafted controls. Rats in the nandrolone group recovered finger flexion faster. At 90 days postsurgery, they had recovered 42% of normal grasp strength versus just 11% in rats grafted but not treated with nandrolone. At 180 days, the average values for grasp strength recovery in the nandrolone and no-nandrolone groups were 40% and 33% of normal values for controls, respectively. At 180 days, finger flexor muscle twitch strength was 16% higher in treated versus nontreated rats. Thresholds for nociception were not detected in either group 90 days after nerve grafting. At 180 days, nociceptive thresholds were significantly lower in the nandrolone group. Nandrolone decanoate improved functional recovery in a model of deficient reinnervation.

  7. Anatomical study of the motor branches of the median nerve to the forearm and guidelines for selective neurectomy.

    PubMed

    Parot, Catalina; Leclercq, Caroline

    2016-07-01

    The median nerve is responsible for the motor innervation of most of the muscles usually involved in upper limb spasticity. Selective neurectomy is one of the treatments utilized to reduce spasticity. The purpose of this study was to describe the variations of the motor branches of the median nerve in the forearm and draw recommendations for an appropriate planning of selective neurectomy. The median nerve was dissected in the forearm of 20 fresh cadaver upper limbs. Measurements included number, origin, division, and entry point of each motor branch into the muscles. One branch for the pronator teres was the most common pattern. In 9/20 cases, it arose as a common trunk with other branches. A single trunk innervated the flexor carpi radialis with a common origin with other branches in 17/20 cases. Two, three or four branches innervated the flexor digitorum superficialis, the first one frequently through a common trunk with other branches. They were very difficult to identify unless insertions of pronator teres and flexor digitorum superficialis were detached. The flexor digitorum profundus received one to five branches and flexor pollicis longus one to two branches from the anterior interosseous nerve. There is no regular pattern of the motor branches of the median nerve in the forearm. Our findings differ in many points from the classical literature. Because of the frequency of common trunks for different muscles, we recommend the use of peroperative electrical stimulation. Selective neurotomy of flexor digitorum superficialis is technically difficult, because the entry point of some of their terminal branches occurs just below the arch and deep to the muscle belly.

  8. Chapter 23: Manual stimulation of target muscles has different impact on functional recovery after injury of pure motor or mixed nerves.

    PubMed

    Sinis, Nektarios; Manoli, Thodora; Werdin, Frank; Kraus, Armin; Schaller, Hans E; Guntinas-Lichius, Orlando; Grosheva, Maria; Irintchev, Andrey; Skouras, Emanouil; Dunlop, Sarah; Angelov, Doychin N

    2009-01-01

    Direct coaptation and interpositional nerve grafting (IPNG) of an injured peripheral nerve is still associated with poor functional recovery. Main reasons for that are thought to be an extensive collateral axonal branching at the site of transection and the polyinnervation of motor endplates due to terminal axonal and intramuscular sprouting. Moreover, severe changes occurring within the muscle after long-term denervation, like loss of muscle bulk and circulation as well as progressive fibrosis, have a negative effect on the quality of functional recovery after reinnervation. We have recently shown that manual stimulation (MS) of paralyzed vibrissal muscles in rat promotes full recovery after facial nerve coaptation. Furthermore, MS improved functional recovery after hypoglossal nerve repair, hypoglossal-facial IPNG of the facial nerve in rat. In contrary, MS did not improve recovery after injury of the median nerve in rat, which is however a mixed peripheral nerve comparing to the facial nerve. It is speculated that manually stimulated recovery of motor function requires an intact sensory input, which is affected in case of mixed peripheral nerves but not in case of pure motor nerves. In this article, we summarize our results of MS in several peripheral nerve injury models in order to illustrate the application potential of this method and to give insights into further investigations on that field.

  9. Further observations on back-firing in the motor nerve fibres of a muscle during twitch contractions.

    PubMed Central

    Buller, A J; Proske, U

    1978-01-01

    1. The tension developed by a muscle in response to a single supramaximal nerve volley is often the sum of two contractions, the second resulting from re-excitation of some nerve terminals during the first contraction. Re-excitation or back-firing can be prevented if the muscle nerve is stimulated twice with the second volley arriving in the muscle at a time when muscle fibres are still refractory following the first volley (Brown & Matthews, 1960). 2. Back-firing has been studied here in the medial gastrocnemius muscle of the spinal cat and responses have been recorded, either representing the summed activity of the muscle's motor supply or discharges of single functional motor axons. 3. When stimulating at a distance from the muscle, the second of two shocks is effective in suppressing back-firing over a narrower range of stimulus intervals than when stimulating close to the muscle. 4. The amount of back-firing can be reduced by stretching the muscle. At a length corresponding to the optimum for a twitch little if any back-firing remains. 5. Measurements of threshold to electrical stimulation of single functional motor axons suggests that low threshold axons are more likely to show back-firing. In the majority of cases, most or all of the motor units in the muscle have to be active before back-firing can be observed. PMID:745126

  10. Motor and sensory nerve conduction are affected differently by ice pack, ice massage, and cold water immersion.

    PubMed

    Herrera, Esperanza; Sandoval, Maria C; Camargo, Diana M; Salvini, Tania F

    2010-04-01

    It is well known that reducing tissue temperature changes sensory and motor nerve conduction. However, few studies have compared the effect of different cold modalities on nerve conduction parameters. The purpose of this study was to compare the effects of ice pack, ice massage, and cold water immersion on the conduction parameters of the sural (sensorial) and tibial motor nerves. An experimental study was conducted in which the participants were randomly assigned to 1 of 3 intervention groups (n=12 per group). Independent variables were cold modality and pre- and post-cooling measurement time. Dependent variables were skin temperature and nerve conduction parameters. Thirty-six people who were healthy, with a mean (SD) age of 20.5 (1.9) years, participated in the study. Each group received 1 of the 3 cold modalities, applied to the right calf region for 15 minutes. Skin temperature and nerve conduction parameters were measured before and immediately after cooling. All 3 modalities reduced skin temperature (mean=18.2 degrees C). There also was a reduction in amplitude and an increase in latency and duration of the compound action potential. Ice massage, ice pack, and cold water immersion reduced sensory nerve conduction velocity (NCV) by 20.4, 16.7, and 22.6 m/s and motor NCV by 2.5, 2.1, and 8.3 m/s, respectively. Cold water immersion was the most effective modality in changing nerve conduction parameters. The cooling area of the ice massage and ice pack was smaller than that of the cold water immersion. The examiner was not blinded to the treatment group. The population included only participants who were healthy and young. All 3 modalities were effective in reducing skin temperature and changing sensory conduction at a physiological level that is sufficient to induce a hypoalgesic effect. The results suggest that cold water immersion, as applied in this study, is the most indicated modality for inducing therapeutic effects associated with the reduction of motor

  11. A Positive Vestibular/Ocular Motor Screening (VOMS) Is Associated With Increased Recovery Time After Sports-Related Concussion in Youth and Adolescent Athletes.

    PubMed

    Anzalone, Anthony J; Blueitt, Damond; Case, Tami; McGuffin, Tiffany; Pollard, Kalyssa; Garrison, J Craig; Jones, Margaret T; Pavur, Robert; Turner, Stephanie; Oliver, Jonathan M

    2017-02-01

    Vestibular and ocular motor impairments are routinely reported in patients with sports-related concussion (SRC) and may result in delayed return to play (RTP). The Vestibular/Ocular Motor Screening (VOMS) assessment has been shown to be consistent and sensitive in identifying concussion when used as part of a comprehensive examination. To what extent these impairments or symptoms are associated with length of recovery is unknown. To examine whether symptom provocation or clinical abnormality in specific domains of the VOMS results in protracted recovery (time from SRC to commencement of RTP protocol). Cohort study (prognosis); Level of evidence, 2. A retrospective chart review was conducted of 167 patients (69 girls, 98 boys; mean ± SD age, 15 ± 2 years [range, 11-19 years]) presenting with SRC in 2014. During the initial visit, VOMS was performed in which symptom provocation or clinical abnormality (eg, unsmooth eye movements) was documented by use of a dichotomous scale (0 = not present, 1 = present). The VOMS used in this clinic consisted of smooth pursuits (SMO_PUR), horizontal and vertical saccades (HOR_SAC and VER_SAC), horizontal and vertical vestibular ocular reflex (HOR_VOR and VER_VOR), near point of convergence (NPC), and accommodation (ACCOM). Domains were also categorized into ocular motor (SMO_PUR, HOR_SAC, VER_SAC, NPC, ACCOM) and vestibular (HOR_VOR, VER_VOR). Cox proportional hazard models were used to explore the relationship between the domains and recovery. Alpha was set at P ≤ .05. Symptom provocation and/or clinical abnormality in all domains except NPC ( P = .107) and ACCOM ( P = .234) delayed recovery (domain, hazard ratio [95% CI]: SMO_PUR, 0.65 [0.47-0.90], P = .009; HOR_SAC, 0.68 [0.50-0.94], P = .018; VER_SAC, 0.55 [0.40-0.75], P < .001; HOR_VOR, 0.68 [0.49-0.94], P = .018; VER_VOR, 0.60 [0.44-0.83], P = .002). The lowest crude hazard ratio was for ocular motor category (0.45 [0.32-0.63], P < .001). These data suggest that symptom

  12. Kv3 voltage-gated potassium channels regulate neurotransmitter release from mouse motor nerve terminals.

    PubMed

    Brooke, Ruth E; Moores, Thomas S; Morris, Neil P; Parson, Simon H; Deuchars, Jim

    2004-12-01

    Voltage-gated potassium (Kv) channels are critical to regulation of neurotransmitter release throughout the nervous system but the roles and identity of the subtypes involved remain unclear. Here we show that Kv3 channels regulate transmitter release at the mouse neuromuscular junction (NMJ). Light- and electron-microscopic immunohistochemistry revealed Kv3.3 and Kv3.4 subunits within all motor nerve terminals of muscles examined [transversus abdominus, lumbrical and flexor digitorum brevis (FDB)]. To determine the roles of these Kv3 subunits, intracellular recordings were made of end-plate potentials (EPPs) in FDB muscle fibres evoked by electrical stimulation of tibial nerve. Tetraethylammonium (TEA) applied at low concentrations (0.05-0.5 mM), which blocks only a few known potassium channels including Kv3 channels, did not affect muscle fibre resting potential but significantly increased the amplitude of all EPPs tested. Significantly, this effect of TEA was still observed in the presence of the large-conductance calcium-activated potassium channel blockers iberiotoxin (25-150 nM) and Penitrem A (100 nM), suggesting a selective action on Kv3 subunits. Consistent with this, 15-microM 4-aminopyridine, which blocks Kv3 but not large-conductance calcium-activated potassium channels, enhanced evoked EPP amplitude. Unexpectedly, blood-depressing substance-I, a toxin selective for Kv3.4 subunits, had no effect at 0.05-1 microM. The combined presynaptic localization of Kv3 subunits and pharmacological enhancement of EPP amplitude indicate that Kv3 channels regulate neurotransmitter release from presynaptic terminals at the NMJ.

  13. Quantal potential fields around individual active zones of amphibian motor-nerve terminals.

    PubMed Central

    Bennett, M R; Farnell, L; Gibson, W G; Macleod, G T; Dickens, P

    2000-01-01

    The release of a quantum from a nerve terminal is accompanied by the flow of extracellular current, which creates a field around the site of transmitter action. We provide a solution for the extent of this field for the case of a quantum released from a site on an amphibian motor-nerve terminal branch onto the receptor patch of a muscle fiber and compare this with measurements of the field using three extracellular electrodes. Numerical solution of the equations for the quantal potential field in cylindrical coordinates show that the density of the field at the peak of the quantal current gives rise to a peak extracellular potential, which declines approximately as the inverse of the distance from the source at distances greater than about 4 microm from the source along the length of the fiber. The peak extracellular potential declines to 20% of its initial value in a distance of about 6 microm, both along the length of the fiber and in the circumferential direction around the fiber. Simultaneous recordings of quantal potential fields, made with three electrodes placed in a line at right angles to an FM1-43 visualized branch, gave determinations of the field strengths in accord with the numerical solutions. In addition, the three electrodes were placed so as to straddle the visualized release sites of a branch. The positions of these sites were correctly predicted on the basis of the theory and independently ascertained by FM1-43 staining of the sites. It is concluded that quantal potential fields at the neuromuscular junction that can be measured with available recording techniques are restricted to regions within about 10 microm of the release site. PMID:10692301

  14. Motor training and the combination of action observation and peripheral nerve stimulation reciprocally interfere with the plastic changes induced in primary motor cortex excitability.

    PubMed

    Bisio, Ambra; Avanzino, Laura; Biggio, Monica; Ruggeri, Piero; Bove, Marco

    2017-04-21

    AO-PNS is a stimulation protocol combining action observation (AO) and peripheral nerve stimulation (PNS) to induce plasticity in the primary motor cortex (M1) (increased excitability). Another method to increase M1 excitability is motor training. The combination of two protocols, which individually induce long-term potentiation (LTP)-like plasticity in overlapping neural circuits, results in a transitory occlusion or reverse of this phenomenon. This study aimed to understand the neurophysiological mechanisms underlying AO-PNS by testing whether AO-PNS and motor training induced LTP-like plasticity in, at least partially, overlapping neural networks. One group of participants practiced a motor training (finger opposition movements) followed by AO-PNS, whereas another group performed the two protocols in reverse order. Motor performance was evaluated by means of a sensor-engineered glove and transcranial magnetic stimulation was used to assess M1 excitability before and after each conditioning protocol. Motor training increased movement frequency, suggesting the occurrence of motor learning in both groups. When applied on first, both motor training and AO-PNS significantly increased the motor-evoked potential (MEP), but occluded the increase of cortical excitability expected after the following protocol, leading to a significant decrease of MEP amplitude. These results suggest that motor training and AO-PNS act on partially overlapping neuronal networks, which include M1, and that AO-PNS might be able to induce LTP-like plasticity in a similar way to overt movement execution. This candidates AO-PNS as methodology potentially useful when planning rehabilitative interventions on patients who cannot voluntarily move.

  15. The anesthetic eye: an investigation of changes in the anterior ocular segment of the monkey caused by interrupting the trigeminal nerve at various levels along its course.

    PubMed Central

    Alper, M G

    1975-01-01

    Operations were performed at four different levels on the fifth nerve of the monkey to determine which procedure offers the best chance of avoiding ocular complications after surgical treatment of trigeminal neuralgia (Figure 18). (1) Section of the ophthalmic branch of N V results in immediate corneal anesthesia. After one week, chromatolysis of the unipolar gasserian ganglion cells subserving the first division occurs and Wallerian degeneration of the corneal nerves of the ipsilateral eye is seen. This is associated with perilimbal round cell invasion of the superficial cornea and subconjunctival area. In addition, iritis develops de novo or becomes worse if it pre-exists. Miosis occurs, but the chemodiagnostic tests of cocaine and adrenalin indicate an intact sympathetic system. The cause for this inflammatory reaction and pupillary change is unexplained by this study. The intraocular pressure is slightly lower on the side of the section than in the normal fellow control eye after surgery, but the difference is not statistically significant. (2) Section of the posterior sensory root of N V in the middle cranial fossa at a point between the gasserian glanglion and the tentorium results in similar ocular changes as is seen after interrupting the ophthalmic division alone. Wallerian degeneration of the corneal nerves, however, is not seen after seven, twelve or twenty-one days. (3) Transtentorial section of the trigeminal posterior sensory root performed in the middle cranial fossa, results in immediate corneal anesthesia. The gasserian ganglion cells, however, remain healthy and there is no perilimbal round cell invasion of the superficial cornea or subconjunctival tissue. Miosis occurs but the chemodiagnostic tests of cocaine and adrenalin indicate an intact sympathetic system. The intraocular pressure is only slightly lower on the side of section than in the control eye, but the difference is not statistically significant. (4) Suboccipital rhizotomy of the

  16. The anesthetic eye: an investigation of changes in the anterior ocular segment of the monkey caused by interrupting the trigeminal nerve at various levels along its course.

    PubMed

    Alper, M G

    1975-01-01

    Operations were performed at four different levels on the fifth nerve of the monkey to determine which procedure offers the best chance of avoiding ocular complications after surgical treatment of trigeminal neuralgia (Figure 18). (1) Section of the ophthalmic branch of N V results in immediate corneal anesthesia. After one week, chromatolysis of the unipolar gasserian ganglion cells subserving the first division occurs and Wallerian degeneration of the corneal nerves of the ipsilateral eye is seen. This is associated with perilimbal round cell invasion of the superficial cornea and subconjunctival area. In addition, iritis develops de novo or becomes worse if it pre-exists. Miosis occurs, but the chemodiagnostic tests of cocaine and adrenalin indicate an intact sympathetic system. The cause for this inflammatory reaction and pupillary change is unexplained by this study. The intraocular pressure is slightly lower on the side of the section than in the normal fellow control eye after surgery, but the difference is not statistically significant. (2) Section of the posterior sensory root of N V in the middle cranial fossa at a point between the gasserian glanglion and the tentorium results in similar ocular changes as is seen after interrupting the ophthalmic division alone. Wallerian degeneration of the corneal nerves, however, is not seen after seven, twelve or twenty-one days. (3) Transtentorial section of the trigeminal posterior sensory root performed in the middle cranial fossa, results in immediate corneal anesthesia. The gasserian ganglion cells, however, remain healthy and there is no perilimbal round cell invasion of the superficial cornea or subconjunctival tissue. Miosis occurs but the chemodiagnostic tests of cocaine and adrenalin indicate an intact sympathetic system. The intraocular pressure is only slightly lower on the side of section than in the control eye, but the difference is not statistically significant. (4) Suboccipital rhizotomy of the

  17. Validity and Reliability of the Vestibular/Ocular Motor Screening and Associations With Common Concussion Screening Tools.

    PubMed

    Yorke, Amy M; Smith, Laura; Babcock, Mitch; Alsalaheen, Bara

    Sustaining a concussion commonly results in vestibular impairments that may be associated with balance deficits. To screen for vestibular impairments after a concussion, the Vestibular/Ocular Motor Screening (VOMS) tool was developed. The relationship between the VOMS and other concussion screening tools, such as the Balance Error Scoring System (BESS) and King-Devick (K-D), have not been explored. (1) VOMS would provide reliable results and not provoke symptoms in healthy adolescents and (2) VOMS test items would measure related aspects of vestibular function that are not measured through the BESS or K-D. Cross-sectional, descriptive. Level 4. A total of 105 healthy adolescents (53 male, 52 female; mean age, 15.4 years) completed the VOMS, BESS, and K-D tests. A subsample of 21 adolescents (16 male, 5 female; mean age, 15.5 years) completed the VOMS twice. The median total symptom score for all 7 VOMS items was 0 (0-5). The majority of the individual VOMS test items total symptom scores demonstrated a significant correlation with each other ( rs = 0.25-0.66, P < 0.02). The individual VOMS items did not demonstrate a significant relationship to the BESS or K-D. VOMS items demonstrated high agreement in total symptom scores between testing trials, with near point convergence (NPC) distance demonstrating an intraclass correlation coefficient (ICC) of 0.95 (95% CI, 0.89-0.98; P < 0.001). The MDC95 (minimal detectable change with 95 confidence) for NPC distance was 4 cm. The VOMS did not provoke vestibular symptoms in healthy adolescents. The VOMS items measured unique aspects of vestibular function other than those measured by the BESS or K-D with good reliability. Clinicians should consider implementing the VOMS as part of a comprehensive concussion assessment if vestibular impairment is suspected. If NPC distance is measured twice, a difference of >4 cm would be considered real change outside of measurement error.

  18. Peripheral Nerve Ultrasonography in Chronic Inflammatory Demyelinating Polyradiculoneuropathy and Multifocal Motor Neuropathy: Correlations with Clinical and Neurophysiological Data

    PubMed Central

    Merola, Aristide; Rosso, Michela; Romagnolo, Alberto; Peci, Erdita; Cocito, Dario

    2016-01-01

    Objective. This cross-sectional study analyzes the pattern of ultrasound peripheral nerve alterations in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and multifocal motor neuropathy (MMN) at different stages of functional disability. Material and Methods. 22 CIDP and 10 MMN patients and a group of 70 healthy controls were evaluated with an ultrasound scan of the median, ulnar, peroneal, tibial, and sural nerves. Results were correlated with clinical disability scales and nerve conduction studies. Results. Patients with intermediate functional impairment showed relatively larger cross-sectional areas than subjects with either a milder (p < 0.05) or more severe impairment (p < 0.05), both in CIDP and in MMN. In addition, MMN was associated with greater side-to-side intranerve variability (p < 0.05), while higher cross-sectional areas were observed in CIDP (p < 0.05) and in nerve segments with predominantly demyelinating features (p < 0.05). Higher CSA values were observed in nerves with demyelinating features versus axonal damage (p < 0.05 for CIDP; p < 0.05 for MMN). Discussion and Conclusions. Greater extent of quantitative and qualitative US alterations was observed in patients at intermediate versus higher functional disability and in nerves with demyelinating versus axonal damage. CIDP and MMN showed differential US aspects, with greater side-to-side intranerve variability in MMN and higher cross-sectional areas in CIDP. PMID:27313890

  19. Anodal transcranial direct current stimulation (tDCS) over the motor cortex increases sympathetic nerve activity.

    PubMed

    Clancy, Jennifer A; Johnson, Robyn; Raw, Rachael; Deuchars, Susan A; Deuchars, Jim

    2014-01-01

    Transcranial direct current stimulation (tDCS) is currently being investigated as a non-invasive neuromodulation therapy for a range of conditions including stroke rehabilitation. tDCS affects not only the area underlying the electrodes but also other areas of the cortex and subcortical structures. This could lead to unintended alteration in brain functions such as autonomic control. We investigated the potential effects of tDCS on cardiovascular autonomic function in healthy volunteers. Anodal (n = 14) or cathodal (n = 8) tDCS at 1 mA was applied over the primary motor cortex with the second electrode placed on the contralateral supraorbital region. Subjects visited the department twice and received active or sham tDCS for 15 min. Heart rate, blood pressure and respiration were recorded at baseline, during tDCS and after stimulation. Heart rate variability (HRV) was calculated using spectral analysis of beat-to-beat intervals derived from ECG data. Microneurography was also used to record muscle sympathetic nerve activity (MSNA; n = 5). Anodal tDCS caused a significant shift in HRV toward sympathetic predominance (P = 0.017), whereas there was no significant change in the cathodal or sham groups. Microneurography results also showed a significant increase in MSNA during anodal tDCS that continued post-stimulation. Anodal tDCS of the motor cortex shifts autonomic nervous system balance toward sympathetic dominance due at least in part to an increase in sympathetic output. These results suggest further investigation is warranted on tDCS use in patient groups with potential autonomic dysfunction, such as stroke patients. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Repetitive common peroneal nerve stimulation increases ankle dorsiflexor motor evoked potentials in incomplete spinal cord lesions.

    PubMed

    Thompson, Aiko K; Lapallo, Brandon; Duffield, Michael; Abel, Briana M; Pomerantz, Ferne

    2011-04-01

    Plasticity of corticospinal tract (CST) activity likely plays a key role in motor function recovery after central nervous system (CNS) lesions. In non-injured adults, 30 min of repetitive common peroneal nerve stimulation (rCPnS) increases CST excitability by 40-50% and the effect persists for at least 30 min. The present study evaluated with transcranial magnetic stimulation (TMS) the changes in CST excitability after 30 min of rCPnS in people with foot drop due to incomplete SCI. Suprathreshold rCPnS (25 Hz, alternating 1 s on 1 s off stimulation cycle) was given for two 15-min periods, while the subject sat at rest with ankle and knee joints fixed. Before, between, and after the periods of stimulation, the tibialis anterior (TA) motor evoked potentials (MEPs) to TMS were measured at a TMS intensity that originally produced a half-maximum MEP (typically 10-20% above threshold) while the sitting subject provided 25-30% maximum voluntary TA contraction. In 10 subjects with SCI, the peak-to-peak TA MEP increased by 14 ± 3% after rCPnS and the peak increase (+21 ± 7%) occurred 15 min after the cessation of rCPnS. The TA H-reflex, measured in separate experiments in 7 subjects, did not increase after rCPnS. The results indicate that rCPnS can increase CST excitability for the TA in people with incomplete SCI, although its effects appear smaller and shorter lasting than those found in non-injured control subjects. Such short-term plasticity in the CST excitability induced by rCPnS may contribute to long-term therapeutic effects of functional electrical stimulation previously reported in people with CNS lesions.

  1. Motor nerve conduction study in cauda equina with high-voltage electrical stimulation in multifocal motor neuropathy and amyotrophic lateral sclerosis.

    PubMed

    Akaza, Miho; Kanouchi, Tadashi; Inaba, Akira; Numasawa, Yoshiyuki; Irioka, Takashi; Mizusawa, Hidehiro; Yokota, Takanori

    2011-02-01

    In this study we aim to establish a motor nerve conduction study (NCS) for the cauda equina and examine its usefulness in multifocal motor neuropathy (MMN) and amyotrophic lateral sclerosis (ALS). NCS of the tibial nerve proximal to the knee was performed with an optimized high-voltage electrical stimulation (HV-ES) method in 21 normal subjects, 5 with MMN, and 11 with ALS. HV-ES, but not magnetic stimulation, could supramaximally stimulate the cauda equina. Cauda equina motor conduction time determined by HV-ES, but not that with F-waves, correlated well with cauda equina length on magnetic resonance imaging. HV-ES revealed proximal lesions in 4 MMN patients but in none of the ALS patients. Importantly, 1 patient with "MMN without conduction block (CB)" had a CB in the cauda equina. Cauda equina motor conduction is better evaluated by HV-ES than with F-wave study or magnetic stimulation. HV-ES can help to distinguish MMN and "MMN without CB" from ALS.

  2. Motor unit recruitment when neuromuscular electrical stimulation is applied over a nerve trunk compared with a muscle belly: triceps surae.

    PubMed

    Bergquist, A J; Clair, J M; Collins, D F

    2011-03-01

    Neuromuscular electrical stimulation (NMES) can be delivered over a nerve trunk or muscle belly and can generate contractions by activating motor (peripheral pathway) and sensory (central pathway) axons. In the present experiments, we compared the peripheral and central contributions to plantar flexion contractions evoked by stimulation over the tibial nerve vs. the triceps surae muscles. Generating contractions through central pathways follows Henneman's size principle, whereby low-threshold motor units are activated first, and this may have advantages for rehabilitation. Statistical analyses were performed on data from trials in which NMES was delivered to evoke 10-30% maximum voluntary torque 2-3 s into the stimulation (Time(1)). Two patterns of stimulation were delivered: 1) 20 Hz for 8 s; and 2) 20-100-20 Hz for 3-2-3 s. Torque and soleus electromyography were quantified at the beginning (Time(1)) and end (Time(2); 6-7 s into the stimulation) of each stimulation train. H reflexes (central pathway) and M waves (peripheral pathway) were quantified. Motor unit activity that was not time-locked to each stimulation pulse as an M wave or H reflex ("asynchronous" activity) was also quantified as a second measure of central recruitment. Torque was not different for stimulation over the nerve or the muscle. In contrast, M waves were approximately five to six times smaller, and H reflexes were approximately two to three times larger during NMES over the nerve vs. the muscle. Asynchronous activity increased by 50% over time, regardless of the stimulation location or pattern, and was largest during NMES over the muscle belly. Compared with NMES over the triceps surae muscles, NMES over the tibial nerve produced contractions with a relatively greater central contribution, and this may help reduce muscle atrophy and fatigue when NMES is used for rehabilitation.

  3. Does the motor branch of the long head of the triceps brachii arise from the radial nerve? An anatomic and electromyographic study.

    PubMed

    de Sèze, M P; Rezzouk, J; de Sèze, M; Uzel, M; Lavignolle, B; Midy, D; Durandeau, A

    2004-12-01

    Anatomy textbooks say that the motor branch of the long head of the triceps brachii (LHT) arises from the radial nerve. Some clinical observations of traumatic injuries of the axillary nerve with associated paralysis of the LHT have suggested that the motor branch of the LHT may arise from the axillary nerve. This anatomic study was performed, using both cadaver anatomical dissections and a surgical study, to determine the exact origin of the motor branch of the LHT. From the adult cadaver specimens (group I), 20 posterior cords were dissected from 10 subjects (eight embalmed, two fresh) using 3.5x magnification. The axillary nerve was followed from its onset to the posteromedial part of the surgical neck of the humerus and the radial nerve. We looked for the origin of the proximal branch of the LHT by a meticulous double anterior and posterior dissection. From the surgical group (group II), 15 posterior cords were dissected from 15 patients suffering from a C5-C6 injured paralysis, without paralysis of the LHT. During the surgical procedure, we looked for the origins of the motor branch of the LHT with a nerve stimulator. In group I, the motor branch of the LHT arose in 13 cases from the axillary nerve near its origin, in five cases from the terminal division of the posterior cord itself, and in two cases from the posterior cord 10 mm before its terminal division into the radial and axillary nerves. In no case did we find the motor branch of the LHT arising from the radial nerve. In eight cases, we found some accessory branches that arose near the principal branch. In group II, the motor branch of the LHT arose in 11 cases from the axillary nerve near its origin and in four cases from the terminal division of the posterior cord itself. The motor branch of the LHT never originated from the radial nerve. In four cases, we found some accessory branches that arose near the principal branch of the LHT. These results reveal that the motor branch of the LHT seems to

  4. Median nerve stimulation modulates extracellular signals in the primary motor area of a macaque monkey.

    PubMed

    Papazachariadis, Odysseas; Dante, Vittorio; Ferraina, Stefano

    2013-08-29

    Aiming to better define the functional influence of somatosensory stimuli on the primary motor cortex (M1) of primates, we investigated changes in extracellular neural activity induced by repetitive median nerve stimulation (MNS). We described neural adaptation and signal integration in both the multiunit activity (MUA) and the local field potential (LFP). To identify integration of initial M1 activity in the MNS response, we tested the correlation between peak amplitude responses and band energy preceding the peaks. Most of the sites studied in the M1 resulted responsive to MNS. MUA response peak amplitude decreased significantly in time in all sites during repetitive MNS, LFP response peak amplitude instead resulted more variable. Similarly, correlation analysis with the initial activity revealed a significant influence when tested using MUA peak amplitude modulation and a less significant correlation when tested using LFP peak amplitude. Our findings improve current knowledge on mechanisms underlying early M1 changes consequent to afferent somatosensory stimuli. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  5. Effect of chronic renal failure, dialysis and transplantation on motor nerve conduction velocity in children.

    PubMed Central

    Arbus, G. S.; Barnor, N. A.; Hsu, A. C.; Murphy, E. G.; Radde, I. C.

    1975-01-01

    Ulnar and peroneal motor nerve conduction volocities (MNCVs) were measured in 47 children in a dialysis-transplantation program. Mean peroneal MNCV was significantly decreased from normal in children with mild renal failure (serum creatinine concentration, 1.5 to 2.9 mg/dl), whereas ulnar MNCV was significantly decreased only when the serum creatinine value was at least 9 mg/dl. Both ulnar and peroneal MNCVs remained unchanged during long-term hemodialysis or peritoneal dialysis; however, after individual dialyses ulnar MNCV increased. After renal transplantation ulnar MNCV returned to normal within a year and peroneal MNCV within 3 years. Before dialysis was required and during long-term dialysis most plasma magnesium values were elevated; ionized calcium activity was decreased in about 50% of determinations. After transplantation and the concentration of divalent cations rapidly returned to normal. These children differed from adults studied in that (a) there was no correlation between severity of renal failure and MNCV, (b) long-term dialysis did not improve MNCV and (c) peroneal velocities did not recover for 3 years after transplantation. PMID:1098759

  6. Motor Nerve Conduction Velocity Depends on Stimuli Frequency in the Rat

    NASA Astrophysics Data System (ADS)

    Méndez, Ma C.; Cruz, Elizabeth; Caudillo, Cipriana; Sosa, Modesto; Gamiño, Sergio M.

    2003-09-01

    This study was performed to evaluate the effect of frequency and duration of stimuli on motor nerve conduction velocity (MNCV) in the rat. MNCV was evaluated in two separate series of records. In the first the frequency of stimuli was varied between 1.0 and 10.0 Hz, by 1 Hz steps, keeping the duration of the pulses constant at 0.1 ms. In a second experimental trial, the frequency of the stimuli was kept at 10.0 Hz, while duration increased from 0.05 to 1.00 ms, at customized steps. Supramaximal stimulation pulses were always used. Measures were performed in the right pelvic limb of 12 anesthetized rats. The active needle electrode was inserted in the second interosseus space of the paw, while a subcutaneous reference electrode was inserted in the third toe. The ground electrode was placed on dorsal surface of the limb. The proximal stimuli site was identified at the sciatic notch and the distal one at the ankle. Surface stimulation was used. Latency, duration, area under the curve and amplitude of the muscular action potential were also measured. MNCV was estimated by dividing distal to proximal latency difference by the distance between stimuli sites. MNCV exhibited an increase to a plateu with stimulus frequency growth. Duration also showed the same behavior.

  7. Potassium channel blocking actions of beta-bungarotoxin and related toxins on mouse and frog motor nerve terminals.

    PubMed Central

    Rowan, E. G.; Harvey, A. L.

    1988-01-01

    1. beta-Bungarotoxin and other snake toxins with phospholipase activity augment acetylcholine release evoked from mouse motor nerve terminals before they produce blockade. This action of the toxins is independent of their phospholipase A2 activity, but the underlying mechanism for the facilitation of release is unclear. To determine whether the toxins affect ionic currents at motor nerve terminals, extracellular recordings were made from perineural sheaths of motor nerves innervating mouse triangularis sterni muscles. 2. Perineural waveforms had a characteristic shape, with two major negative deflections, the first being associated with nodal Na+ currents and the second with terminal K+ currents. Block of the K+ currents revealed a Ca2+-dependent component. 3. During the facilitatory phase of its action, beta-bungarotoxin (150 nM) reduced the second negative component of the perineural waveform by 30-50%. 4. The reduction could be a consequence of a decreased K+ ion contribution or of an increase in the current carried by Ca2+. As beta-bungarotoxin had similar effects in solutions which contained no added Ca2+, it is unlikely to be acting on the Ca2+ current. Also, it is unlikely to be blocking the Ca2+-activated K+ current, which is suppressed in zero Ca2+ conditions. 5. Other prejunctionally active snake toxins (taipoxin, notexin and crotoxin) had similar effects to those of beta-bungarotoxin, but a similar basic phospholipase of low toxicity from cobra venom had no effect. 6. Thus, beta-bungarotoxin and related toxins block a fraction of the K+ current in the motor nerve terminals of mouse preparations.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3263160

  8. Ocular disease and driving.

    PubMed

    Wood, Joanne M; Black, Alex A

    2016-09-01

    As the driving population ages, the number of drivers with visual impairment resulting from ocular disease will increase given the age-related prevalence of ocular disease. The increase in visual impairment in the driving population has a number of implications for driving outcomes. This review summarises current research regarding the impact of common ocular diseases on driving ability and safety, with particular focus on cataract, glaucoma, age-related macular degeneration, hemianopia and diabetic retinopathy. The evidence considered includes self-reported driving outcomes, driving performance (on-road and simulator-based) and various motor vehicle crash indices. Collectively, this review demonstrates that driving ability and safety are negatively affected by ocular disease; however, further research is needed in this area. Older drivers with ocular disease need to be aware of the negative consequences of their ocular condition and in the case where treatment options are available, encouraged to seek these earlier for optimum driving safety and quality of life benefits.

  9. Simultaneous expression of glutathione, thioredoxin-1, and their reductases in nerve transected hypoglossal motor neurons of rat.

    PubMed

    Hama, Isuzu; Nakagomi, Saya; Konishi, Hiroyuki; Kiyama, Hiroshi

    2010-01-08

    Anti-oxidative stress responses are crucial for the survival of nerve-injured motor neurons. Herein, we examined changes in expression of glutathione reductase (GSHr), thioredoxins (TRX1 and TRX2), and thioredoxin reductases (TRXr1 and TRXr2), important constituents of anti-oxidative pathways, following rat hypoglossal nerve transection. RT-PCR and in situ hybridization demonstrated that GSHr, TRX1, and TRXr1 mRNAs were significantly up-regulated during the first few weeks in nerve-injured motor neurons, while TRX2 and TRXr2 mRNAs were unchanged throughout 8 weeks after nerve transection. The up-regulation of GSH, GSHr, TRX1, and TRXr1 proteins in injured neurons was confirmed by immunohistochemical analysis. Western blotting also demonstrated up-regulation of GSHr, TRX1, and TRXr1 in injured neurons. These data suggest that the two major redox systems, GSH/GSHr and TRX1/TRXr1, are simultaneously activated in injured neurons, and likely provide protection of injured neurons against oxidative stress.

  10. Neuromuscular electrical stimulation of the median nerve facilitates low motor cortex excitability in patients with spinocerebellar ataxia.

    PubMed

    Chen, Chih-Chung; Chuang, Yu-Fen; Yang, Hsiao-Chu; Hsu, Miao-Ju; Huang, Ying-Zu; Chang, Ya-Ju

    2015-02-01

    The neuromodulation of motor excitability has been shown to improve functional movement in people with central nervous system damage. This study aimed to investigate the mechanism of peripheral neuromuscular electrical stimulation (NMES) in motor excitability and its effects in people with spinocerebellar ataxia (SCA). This single-blind case-control study was conducted on young control (n=9), age-matched control (n=9), and SCA participants (n=9; 7 SCAIII and 2 sporadic). All participants received an accumulated 30 min of NMES (25 Hz, 800 ms on/800 ms off) of the median nerve. The central motor excitability, measured by motor evoked potential (MEP) and silent period, and the peripheral motor excitability, measured by the H-reflex and M-wave, were recorded in flexor carpi radialis (FCR) muscle before, during, and after the NMES was applied. The results showed that NMES significantly enhanced the MEP in all 3 groups. The silent period, H-reflex and maximum M-wave were not changed by NMES. We conclude that NMES enhances low motor excitability in patients with SCA and that the mechanism of the neuromodulation was supra-segmental. These findings are potentially relevant to the utilization of NMES for preparation of motor excitability. The protocol was registered at Clinicaltrials.gov (NCT02103075). Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. Pontine-to-midbrain ratio indexes ocular-motor function and illness stage in adult Niemann-Pick disease type C.

    PubMed

    Walterfang, M; Macfarlane, M D; Looi, J C L; Abel, L; Bowman, E; Fahey, M C; Desmond, P; Velakoulis, D

    2012-03-01

    Niemann-Pick disease type C (NPC) is a progressive neurovisceral disorder associated with dystonia, ataxia and a characteristic gaze palsy. Neuropathological studies have demonstrated brainstem atrophy associated with neuronal inclusions and loss, and neurofibrillary tangles, although it is not known whether this pathology can be detected in vivo or how these changes relate to illness variables, particularly ocular-motor changes. Our aim was to utilize a method for brainstem atrophy, validated in progressive supranuclear palsy (PSP), in a group of adult patients with NPC, and explore its relationship to illness variables and ocular-motor functioning. We calculated the midbrain and pontine area, and pontine-to-midbrain ratio (PMR) from midsagittal images of 10 adult patients with NPC and 27 age- and gender-matched controls. Measures were correlated with illness variables, and measures of horizontal saccadic functioning. Pontine-to-midbrain ratio was 14% higher in the NPC group, but this difference was not significant. However, PMR showed a significant positive correlation with duration of illness and a measure of illness severity. Furthermore, PMR was significantly negatively correlated with saccadic peak velocity and gain, and self-paced saccadic performance. Pontine-to-midbrain ratio was increased in adult patients with NPC compared to controls, although not to the same degree as previously described in PSP, which also presents with significant gaze palsy. These changes were driven predominantly by progressive midbrain atrophy. The strong correlation with illness and ocular-motor variables suggests that it may be a useful marker for illness progression in NPC. © 2011 The Author(s). European Journal of Neurology © 2011 EFNS.

  12. Effect of Treating Streptozotocin-Induced Diabetic Rats With Sorbinil, Myo-Inositol or Aminoguanidine on Endoneurial Blood Flow, Motor Nerve Conduction Velocity and Vascular Function of Epineurial Arterioles of the Sciatic Nerve

    PubMed Central

    Coppey, Lawrence J.; Gellett, Jill S.; Davidson, Eric P.; Dunlap, Joyce A.

    2002-01-01

    Previously we have demonstrated that diabetes causes impairment in vascular function of epineurial vessels, which precedes the slowing of motor nerve conduction velocity. Treatment of diabetic rats with aldose reductase inhibitors, aminoguanidine or myo-inositol supplementation have been shown to improve motor nerve conduction velocity and/or decreased endoneurial blood flow. However, the effect these treatments have on vascular reactivity of epineurial vessels of the sciatic nerve is unknown. In these studies we examined the effect of treating streptozotocininduced rats with sorbinil, aminoguanidine or myo-inositol on motor nerve conduction velocity, endoneurial blood flow and endothelium dependent vascular relaxation of arterioles that provide circulation to the region of the sciatic nerve. Treating diabetic rats with sorbinil, aminoguanidine or myo-inositol improved the reduction of endoneurial blood flow and motor nerve conduction velocity. However, only sorbinil treatment significantly improved the diabetes-induced impairment of acetylcholinemediated vasodilation of epineurial vessels of the sciatic nerve. All three treatments were efficacious in preventing the appropriate metabolic derangements associated with either activation of the polyol pathway or increased nonenzymatic glycation. In addition, sorbinil was shown to prevent the diabetes-induced decrease in lens glutathione level. However, other markers of oxidative stress were not vividly improved by these treatments. These studies suggest that sorbinil treatment may be more effective in preventing neural dysfunction in diabetes than either aminoguanidine or myoinositol. PMID:11900277

  13. Refining the Sensory and Motor Ratunculus of the Rat Upper Extremity Using fMRI and Direct Nerve Stimulation

    PubMed Central

    Cho, Younghoon R.; Pawela, Christopher P.; Li, Rupeng; Kao, Dennis; Schulte, Marie L.; Runquist, Matthew L.; Yan, Ji-Geng; Matloub, Hani S.; Jaradeh, Safwan S.; Hudetz, Anthony G.; Hyde, James S.

    2008-01-01

    It is well understood that the different regions of the body have cortical representations in proportion to the degree of innervation. Our current understanding of the rat upper extremity has been enhanced using functional MRI (fMRI), but these studies are often limited to the rat forepaw. The purpose of this study is to describe a new technique that allows us to refine the sensory and motor representations in the cerebral cortex by surgically implanting electrodes on the major nerves of the rat upper extremity and providing direct electrical nerve stimulation while acquiring fMRI images. This technique was used to stimulate the ulnar, median, radial, and musculocutaneous nerves in the rat upper extremity using four different stimulation sequences that varied in frequency (5 Hz vs. 10 Hz) and current (0.5 mA vs. 1.0 mA). A distinct pattern of cortical activation was found for each nerve. The higher stimulation current resulted in a dramatic increase in the level of cortical activation. The higher stimulation frequency resulted in both increases and attenuation of cortical activation in different regions of the brain, depending on which nerve was stimulated. PMID:17969116

  14. N10 potential as an antidromic motor evoked potential in a median nerve short-latency somatosensory evoked potential study.

    PubMed

    Inoue, Ken; Mimori, Yasuyo; Nakamura, Shigenobu

    2002-01-01

    When stimulating the mixed nerve to record evoked potential, both sensory and motor fibers are activated before entering the spinal cord. The N10 potential has been described as an antidromic motor evoked potential based on results obtained by recording at the anterior midneck. In the present study, we examined the changes in latencies of Erb's potential, N10, and N13 by stimulating the median nerve distally at the wrist and proximally at the elbow. The conduction velocity of N10 calculated by the difference between N10 latencies at the two stimulation points was consistent with motor conduction velocity, although N13 conduction velocity estimated by the same method reflected a sensory conduction velocity. A positive relation was also observed between the indirect latency from the stimulation point to the anterior root as calculated using the equation (F - M - 1) / 2 (ms) and the direct latency to the negative peak of the N10 potential. Our data support the notion that N10 represents antidromic motor potential originating in the spinal entry zone of the anterior root.

  15. Noninvasive Peroneal Sensory and Motor Nerve Conduction Recordings in the Rabbit Distal Hindlimb: Feasibility, Variability and Neuropathy Measure

    PubMed Central

    Hotson, John R.

    2014-01-01

    The peroneal nerve anatomy of the rabbit distal hindlimb is similar to humans, but reports of distal peroneal nerve conduction studies were not identified with a literature search. Distal sensorimotor recordings may be useful for studying rabbit models of length-dependent peripheral neuropathy. Surface electrodes were adhered to the dorsal rabbit foot overlying the extensor digitorum brevis muscle and the superficial peroneal nerve. The deep and superficial peroneal nerves were stimulated above the ankle and the common peroneal nerve was stimulated at the knee. The nerve conduction studies were repeated twice with a one-week intertest interval to determine measurement variability. Intravenous vincristine was used to produce a peripheral neuropathy. Repeat recordings measured the response to vincristine. A compound muscle action potential and a sensory nerve action potential were evoked in all rabbits. The compound muscle action potential mean amplitude was 0.29 mV (SD ± 0.12) and the fibula head to ankle mean motor conduction velocity was 46.5 m/s (SD ± 2.9). The sensory nerve action potential mean amplitude was 22.8 μV (SD ± 2.8) and the distal sensory conduction velocity was 38.8 m/s (SD ± 2.2). Sensorimotor latencies and velocities were least variable between two test sessions (coefficient of variation  =  2.6–5.9%), sensory potential amplitudes were intermediate (coefficient of variation  =  11.1%) and compound potential amplitudes were the most variable (coefficient of variation  = 19.3%). Vincristine abolished compound muscle action potentials and reduced sensory nerve action potential amplitudes by 42–57% while having little effect on velocity. Rabbit distal hindlimb nerve conduction studies are feasible with surface recordings and stimulation. The evoked distal sensory potentials have amplitudes, configurations and recording techniques that are similar to humans and may be valuable for measuring large sensory fiber function in chronic

  16. Effect of transgenic human insulin-like growth factor-1 on spinal motor neurons following peripheral nerve injury.

    PubMed

    Gu, Jiaxiang; Liu, Hongjun; Zhang, Naichen; Tian, Heng; Pan, Junbo; Zhang, Wenzhong; Wang, Jingcheng

    2015-07-01

    The aim of the present study was to observe the protective effect of exogenous human insulin-like growth factor-1 (hIGF-1) on spinal motor neurons, following its local transfection into an area of peripheral nerve injury. A total of 90 male Wistar rats that had been established as sciatic nerve crush injury models were randomly divided into three groups: hIGF-1 treatment, sham-transfected control and blank control groups. The different phases of hIGF-1 expression were observed in the spinal cord via postoperative immunostaining and the apoptosis of motor neurons was observed using the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling method. Pathological changes of the motor neurons and Nissl bodies within cell bodies were observed via Marsland and Luxol fast blue double staining, while changes in the neuropil of the spinal cord anterior horn were investigated via ultrastructural observation. It was found that hIGF-1, locally transfected into an area of peripheral nerve injury, was expressed in the spinal anterior horn following axoplasmic transport; the peak hIGF-1 expression occurred approximately a week following transfection. The number of apoptotic spinal cord motor neurons observed in the hIGF-1 treatment group was fewer than that in the sham-transfected and blank control groups at days 7, 14 and 21 following transfection (P<0.01). Furthermore, the quantity of motor neuron cells in the anterior horn of the spinal cord in the hIGF-1 treatment group was higher compared with those in the sham-transfected and blank control groups at days 2, 7, 14 and 28 following transfection (P<0.01). The degenerative changes of Nissl bodies within the cytoplasm of the hIGF-1 treatment group were less severe compared with those of the sham-transfected and blank control groups. At day 56 following transfection, the spinal anterior horn neuropil ultrastructure in the hIGF-1 treatment group was generally normal, while the sham-transfected and blank control

  17. Simulation system of spinal cord motor nuclei and associated nerves and muscles, in a Web-based architecture.

    PubMed

    Cisi, Rogerio R L; Kohn, André F

    2008-12-01

    A Web-based simulation system of the spinal cord circuitry responsible for muscle control is described. The simulator employs two-compartment motoneuron models for S, FR and FF types, with synaptic inputs acting through conductance variations. Four motoneuron pools with their associated interneurons are represented in the simulator, with the possibility of inclusion of more than 2,000 neurons and 2,000,000 synapses. Each motoneuron action potential is followed, after a conduction delay, by a motor unit potential and a motor unit twitch. The sums of all motor unit potentials and twitches result in the electromyogram (EMG), and the muscle force, respectively. Inputs to the motoneuron pool come from populations of interneurons (Ia reciprocal inhibitory interneurons, Ib interneurons, and Renshaw cells) and from stochastic point processes associated with descending tracts. To simulate human electrophysiological experiments, the simulator incorporates external nerve stimulation with orthodromic and antidromic propagation. This provides the mechanisms for reflex generation and activation of spinal neuronal circuits that modulate the activity of another motoneuron pool (e.g., by reciprocal inhibition). The generation of the H-reflex by the Ia-motoneuron pool system and its modulation by spinal cord interneurons is included in the simulation system. Studies with the simulator may include the statistics of individual motoneuron or interneuron spike trains or the collective effect of a motor nucleus on the dynamics of muscle force control. Properties associated with motor-unit recruitment, motor-unit synchronization, recurrent inhibition and reciprocal inhibition may be investigated.

  18. Sensitivity and specificity of monochromatic photography of the ocular fundus in differentiating optic nerve head drusen and optic disc oedema: optic disc drusen and oedema.

    PubMed

    Gili, Pablo; Flores-Rodríguez, Patricia; Yangüela, Julio; Orduña-Azcona, Javier; Martín-Ríos, María Dolores

    2013-03-01

    Evaluation of the efficacy of monochromatic photography of the ocular fundus in differentiating optic nerve head drusen (ONHD) and optic disc oedema (ODE). Sixty-six patients with ONHD, 31 patients with ODE and 70 healthy subjects were studied. Colour and monochromatic fundus photography with different filters (green, red and autofluorescence) were performed. The results were analysed blindly by two observers. The sensitivity, specificity and interobserver agreement (k) of each test were assessed. Colour photography offers 65.5 % sensitivity and 100 % specificity for the diagnosis of ONHD. Monochromatic photography improves sensitivity and specificity and provides similar results: green filter (71.20 % sensitivity, 96.70 % specificity), red filter (80.30 % sensitivity, 96.80 % specificity), and autofluorescence technique (87.8 % sensitivity, 100 % specificity). The interobserver agreement was good with all techniques used: autofluorescence (k = 0.957), green filter (k = 0.897), red filter (k = 0.818) and colour (k = 0.809). Monochromatic fundus photography permits ONHD and ODE to be differentiated, with good sensitivity and very high specificity. The best results were obtained with autofluorescence and red filter study.

  19. Reaching the Limit of the Oculomotor Plant: 3D Kinematics after Abducens Nerve Stimulation during the Torsional Vestibulo-Ocular Reflex

    PubMed Central

    Meng, Hui; Angelaki, Dora E.

    2012-01-01

    Accumulating evidence shows that the oculomotor plant is capable of implementing aspects of three-dimensional kinematics such as Listing's law and the half-angle rule. But these studies have only examined the eye under static conditions or with movements that normally obey these rules (e.g., saccades and pursuit). Here we test the capability of the oculomotor plant to rearrange itself as necessary for non-half-angle behavior. Three monkeys (Macaca mulatta) fixated five vertically displaced targets along the midsagittal plane while sitting on a motion platform that rotated sinusoidally about the naso-occipital axis. This activated the torsional, rotational vestibulo-ocular reflex, which exhibits a zero-angle or negative-angle rule (depending on the visual stimulus). On random sinusoidal cycles, we stimulated the abducens nerve and observed the resultant eye movements. If the plant has rearranged itself to implement this non-half-angle behavior, then stimulation should reveal this behavior. On the other hand, if the plant is only capable of half-angle behavior, then stimulation should reveal a half-angle rule. We find the latter to be true and therefore additional neural signals are likely necessary to implement non-half-angle behavior. PMID:22993439

  20. Hyperemic responses of the optic nerve head blood flow to chromatic equiluminant flicker are reduced by ocular hypertension and early glaucoma

    NASA Astrophysics Data System (ADS)

    Falsini, Benedetto; Riva, Charles E.; Salgarello, Tommaso; Logean, Eric; Colotto, Alberto; Giudiceandrea, Andrea

    2014-06-01

    We evaluated in ocular hypertension (OHT) and early glaucoma (EOAG) patients the optic nerve head (ONH) blood flow response (RF) to chromatic equiluminant flicker. This stimulus generates neural activity dominated by the parvo-cellular system. Eleven EOAG, 20 OHT patients, and 8 age-matched control subjects were examined. The blood flow (F) at the neuroretinal rim was continuously monitored by laser Doppler flowmetry before, during, and after a 60-s exposure to a 4 Hz, red-green equiluminant flicker stimulus (30 deg field). RF was expressed as percentage F-change during the last 20 s of flicker relative to baseline F. Responses were collected at a number of temporal sites. The highest RF value was used for subsequent analysis. As compared to controls, both OHT and EOAG patients showed a decrease (p<0.01) in mean RF. We conclude that RF elicited by chromatic equiluminant flicker is abnormally reduced in OHT and EOAG patients indicating an impairment of the parvo-cellular-mediated vasoactivity. This decrease of vascular response may occur independently of neural activity loss early in the disease process.

  1. Delineation of the working memory profile in female FMR1 premutation carriers: the effect of cognitive load on ocular motor responses.

    PubMed

    Shelton, Annie L; Cornish, Kim M; Godler, David E; Clough, Meaghan; Kraan, Claudine; Bui, Minh; Fielding, Joanne

    2015-04-01

    Fragile X mental retardation 1 (FMR1) premutation carriers (PM-carriers) are characterised as having mid-sized expansions of between 55 and 200 CGG repeats in the 5' untranslated region of the FMR1 gene. While there is evidence of executive dysfunction in PM-carriers, few studies have explicitly explored working memory capabilities in female PM-carriers. 14 female PM-carriers and 13 age- and IQ-matched healthy controls completed an ocular motor n-back working memory paradigm. This task examined working memory ability and the effect of measured increases in cognitive load. Female PM-carriers were found to have attenuated working memory capabilities. Increasing the cognitive load did not elicit the expected reciprocal increase in the task errors for female PM-carriers, as it did in controls. However female PM-carriers took longer to respond than controls, regardless of the cognitive load. Further, FMR1 mRNA levels were found to significantly predict PM-carrier response time. Although preliminary, these findings provide further evidence of executive dysfunction, specifically disruption to working memory processes, which were found to be associated with increases in FMR1 mRNA expression in female PM-carriers. With future validation, ocular motor paradigms such as the n-back paradigm will be critical to the development of behavioural biomarkers for identification of PM-carrier cognitive-affective phenotypes.

  2. Hydrogen-rich saline promotes motor functional recovery following peripheral nerve autografting in rats

    PubMed Central

    ZHANG, YONG-GUANG; SHENG, QING-SONG; WANG, ZHI-JUN; LV, LI; ZHAO, WEI; CHEN, JIAN-MEI; XU, HAO

    2015-01-01

    Despite the application of nerve grafts and considerable microsurgical innovations, the functional recovery across a long peripheral nerve gap is generally partial and unsatisfactory. Thus, additional strategies are required to improve nerve regeneration across long nerve gaps. Hydrogen possesses antioxidant and anti-apoptotic properties, which could be neuroprotective in the treatment of peripheral nerve injury; however, such a possibility has not been experimentally tested in vivo. The aim of the present study was to investigate the effectiveness of hydrogen-rich saline in promoting nerve regeneration after 10-mm sciatic nerve autografting in rats. The rats were randomly divided into two groups and intraperitoneally administered a daily regimen of 5 ml/kg hydrogen-rich or normal saline. Axonal regeneration and functional recovery were assessed through a combination of behavioral analyses, electrophysiological evaluations, Fluoro-Gold™ retrograde tracings and histomorphological observations. The data showed that rats receiving hydrogen-rich saline achieved better axonal regeneration and functional recovery than those receiving normal saline. These findings indicated that hydrogen-rich saline promotes nerve regeneration across long gaps, suggesting that hydrogen-rich saline could be used as a neuroprotective agent for peripheral nerve injury therapy. PMID:26622383

  3. Broadband Prosthetic Interfaces: Combining Nerve Transfers and Implantable Multichannel EMG Technology to Decode Spinal Motor Neuron Activity

    PubMed Central

    Bergmeister, Konstantin D.; Vujaklija, Ivan; Muceli, Silvia; Sturma, Agnes; Hruby, Laura A.; Prahm, Cosima; Riedl, Otto; Salminger, Stefan; Manzano-Szalai, Krisztina; Aman, Martin; Russold, Michael-Friedrich; Hofer, Christian; Principe, Jose; Farina, Dario; Aszmann, Oskar C.

    2017-01-01

    Modern robotic hands/upper limbs may replace multiple degrees of freedom of extremity function. However, their intuitive use requires a high number of control signals, which current man-machine interfaces do not provide. Here, we discuss a broadband control interface that combines targeted muscle reinnervation, implantable multichannel electromyographic sensors, and advanced decoding to address the increasing capabilities of modern robotic limbs. With targeted muscle reinnervation, nerves that have lost their targets due to an amputation are surgically transferred to residual stump muscles to increase the number of intuitive prosthetic control signals. This surgery re-establishes a nerve-muscle connection that is used for sensing nerve activity with myoelectric interfaces. Moreover, the nerve transfer determines neurophysiological effects, such as muscular hyper-reinnervation and cortical reafferentation that can be exploited by the myoelectric interface. Modern implantable multichannel EMG sensors provide signals from which it is possible to disentangle the behavior of single motor neurons. Recent studies have shown that the neural drive to muscles can be decoded from these signals and thereby the user's intention can be reliably estimated. By combining these concepts in chronic implants and embedded electronics, we believe that it is in principle possible to establish a broadband man-machine interface, with specific applications in prosthesis control. This perspective illustrates this concept, based on combining advanced surgical techniques with recording hardware and processing algorithms. Here we describe the scientific evidence for this concept, current state of investigations, challenges, and alternative approaches to improve current prosthetic interfaces. PMID:28769755

  4. Movement and afferent representations in human motor areas: a simultaneous neuroimaging and transcranial magnetic/peripheral nerve-stimulation study

    PubMed Central

    Shitara, H.; Shinozaki, T.; Takagishi, K.; Honda, M.; Hanakawa, T.

    2013-01-01

    Neuroimaging combined with transcranial magnetic stimulation (TMS) to primary motor cortex (M1) is an emerging technique that can examine motor-system functionality through evoked activity. However, because sensory afferents from twitching muscles are widely represented in motor areas the amount of evoked activity directly resulting from TMS remains unclear. We delivered suprathreshold TMS to left M1 or gave electrical right median nerve stimulation (MNS) in 18 healthy volunteers while simultaneously conducting functional magnetic resonance imaging and monitoring with electromyography (EMG). We examined in detail the localization of TMS-, muscle afferent- and superficial afferent-induced activity in M1 subdivisions. Muscle afferent- and TMS-evoked activity occurred mainly in rostral M1, while superficial afferents generated a slightly different activation distribution. In 12 participants who yielded quantifiable EMG, differences in brain activity ascribed to differences in movement-size were adjusted using integrated information from the EMGs. Sensory components only explained 10–20% of the suprathreshold TMS-induced activity, indicating that locally and remotely evoked activity in motor areas mostly resulted from the recruitment of neural and synaptic activity. The present study appears to justify the use of fMRI combined with suprathreshold TMS to M1 for evoked motor network imaging. PMID:24062660

  5. Noninvasive and painless magnetic stimulation of nerves improved brain motor function and mobility in a cerebral palsy case.

    PubMed

    Flamand, Véronique H; Schneider, Cyril

    2014-10-01

    Motor deficits in cerebral palsy disturb functional independence. This study tested whether noninvasive and painless repetitive peripheral magnetic stimulation could improve motor function in a 7-year-old boy with spastic hemiparetic cerebral palsy. Stimulation was applied over different nerves of the lower limbs for 5 sessions. We measured the concurrent aftereffects of this intervention on ankle motor control, gait (walking velocity, stride length, cadence, cycle duration), and function of brain motor pathways. We observed a decrease of ankle plantar flexors resistance to stretch, an increase of active dorsiflexion range of movement, and improvements of corticospinal control of ankle dorsiflexors. Joint mobility changes were still present 15 days after the end of stimulation, when all gait parameters were also improved. Resistance to stretch was still lower than prestimulation values 45 days after the end of stimulation. This case illustrates the sustained effects of repetitive peripheral magnetic stimulation on brain plasticity, motor function, and gait. It suggests a potential impact for physical rehabilitation in cerebral palsy. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  6. Localization and expression of ciliary neurotrophic factor (CNTF) in postmortem sciatic nerve from patients with motor neuron disease and diabetic neuropathy

    SciTech Connect

    Lee, D.A.; Gross, L.; Wittrock, D.A.; Windebank, A.J.

    1996-08-01

    Ciliary neurotrophic factor (CNTF) is thought to play an important role in the maintenance of the mature motor system. The factor is found most abundantly in myelinating Schwann cells in the adult sciatic nerve. Lack of neuronal growth factors has been proposed as one possible etiology of amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA). Growth factor replacement therapies are currently being evaluated as a treatment for motor neuron disease. In this report we determined whether the expression of CNTF in sciatic nerve differed in patients with motor neuron disease compared to controls or patients with another form of axonopathy. We identified 8 patients (7 with ALS and 1 with SMA) with motor neuron disease and 6 patients with diabetic motor neuropathy who had autopsy material available. Immunoperoxidase staining showed reduced CNTF expression in nerves of patients with motor neuron disease but not in patients with diabetic motor neuropathy. Decreased CNTF appears be associated with primary motor neuron disease rather than a generalized process of axon loss. This result supports suggestions that CNTF deficiency may be an important factor in the development of motor neuron disease. 20 refs., 4 figs., 1 tab.

  7. Recovery of motor neuron excitability after facial nerve impairment in rats.

    PubMed

    Ohki, Masafumi; Takeuchi, Naonobu

    2014-05-07

    Multiple studies have demonstrated alterations in excitability in the central nervous system after peripheral nerve injury. However, there are few reports on changes in the central nervous system after peripheral facial nerve injury. Our objective was to determine the excitability changes that occur in the facial nucleus after facial nerve impairment. The excitability changes in the facial nucleus were investigated by assessing two types of compound muscle action potentials (M and F waves) in the orbicularis oculi muscles, evoked by electrical stimulation of the zygomatic branch of the facial nerve. In rats, M and F waves were measured in the orbicularis oculi muscles before and every week up to 8 weeks after the application of nerve compression under anesthesia. M and F waves disappeared after nerve compression, only to reappear 2 weeks later, although M-wave amplitude was decreased and the latencies of both waves were delayed. Thereafter, these waves recovered gradually. During the recovery period, the F/M wave amplitude ratio, which is an indicator of facial nucleus excitability, significantly increased on the impaired side but not on the intact side. This increase was most prominent within 3 weeks; thereafter, the ratio gradually decreased and reached the levels recorded before facial nerve impairment by 7 weeks. Facial nerve impairment leads to hyperexcitability of the facial nucleus during the recovery period.

  8. On the calcium receptor that mediates depolarization-secretion coupling at cholinergic motor nerve terminals

    PubMed Central

    Silinsky, E.M.

    1981-01-01

    Ca that produce equal levels of ACh release in the presence and absence of La3+ (0.5 μm-3 μm). KCa was estimated to be between 0.02 and 0.06 mm-1. 6 Efficacy (e), which is thought to reflect the ability of Ca or Sr once bound to receptors to support ACh release, was determined by the modified occupation theory of Stephenson (1956). The eCa was estimated to be 9-20 and eSr was 0.2-0.5. 7 The experimentally determined values for KCa, KSr, eCa, eSr along with the assumptions that spare Ca binding sites exist and that the non-linearities in the log [Ca] or log [Sr]-m̄ curves are introduced beyond the sites of binding and efficacy were used to generate theoretical log [Me]-m̄ curves. The theoretical relationships were similar to the experimental results. 8 The results suggest that spare Ca receptors are present at motor nerve endings and that receptor theory provides an accurate quantitative description of the lumped events between Ca binding and ACh secretion. The possible physical correlates of affinity and efficacy are discussed. PMID:6972242

  9. Optic nerve sheath diameter threshold by ocular ultrasonography for detection of increased intracranial pressure in Korean adult patients with brain lesions

    PubMed Central

    Lee, Si Un; Jeon, Jin Pyeong; Lee, Hannah; Han, Jung Ho; Seo, Mingu; Byoun, Hyoung Soo; Cho, Won-Sang; Ryu, Ho Geol; Kang, Hyun-Seung; Kim, Jeong Eun; Kim, Heung Cheol; Jang, Kyung-Sool

    2016-01-01

    Abstract Optic nerve sheath diameter (ONSD) seen on ocular US has been associated with increased intracranial pressure (IICP). However, most studies have analyzed normal range of ONSD and its optimal cut-off point for IICP in Caucasian populations. Considering ONSD differences according to ethnicity, previous results may not accurately reflect the association between IICP and ONSD in Koreans. Therefore, we conducted this study to investigate normal range of ONSD and its optimal threshold for detecting IICP in Korean patients. This prospective multicenter study was performed for patients with suspected IICP. ONSD was measured 3 mm behind the globe using a 13-MHz US probe. IICP was defined as significant brain edema, midline shift, compression of ventricle or basal cistern, effacement of sulci, insufficient gray/white differentiation, and transfalcine herniation by radiologic tests. The results of the ONSD are described as the median (25th–75th percentile). The differences of ONSD according to disease entity were analyzed. A receiver operator characteristic (ROC) curve was generated to determine the optimal cut-off point for identifying IICP. A total of 134 patients were enrolled. The patients were divided into 3 groups as follows: patients with IICP, n = 81 (60.5%); patients without IICP, n = 27 (20.1%); and control group, n = 26 (19.4%). ONSD in patients with IICP (5.9 mm [5.8–6.2]) is significantly higher than those without IICP (5.2 mm [4.8–5.4]) (P < 0.01) and normal control group (4.9 mm [4.6–5.2]) (P < 0.001). Between patients without IICP and normal control group, the difference of ONSD did not reach statistical significance (P = 0.31). ONSD >5.5 mm yielded a sensitivity of 98.77% (95% CI: 93.3%–100%) and a specificity of 85.19% (95% CI: 66.3%–95.8%). In conclusion, the optimal cut-off point of ONSD for identifying IICP was 5.5 mm. ONSD seen on ocular US can be a feasible method for detection and serial monitoring of ICP in

  10. Presence and Absence of Muscle Contraction Elicited by Peripheral Nerve Electrical Stimulation Differentially Modulate Primary Motor Cortex Excitability.

    PubMed

    Sasaki, Ryoki; Kotan, Shinichi; Nakagawa, Masaki; Miyaguchi, Shota; Kojima, Sho; Saito, Kei; Inukai, Yasuto; Onishi, Hideaki

    2017-01-01

    Modulation of cortical excitability by sensory inputs is a critical component of sensorimotor integration. Sensory afferents, including muscle and joint afferents, to somatosensory cortex (S1) modulate primary motor cortex (M1) excitability, but the effects of muscle and joint afferents specifically activated by muscle contraction are unknown. We compared motor evoked potentials (MEPs) following median nerve stimulation (MNS) above and below the contraction threshold based on the persistence of M-waves. Peripheral nerve electrical stimulation (PES) conditions, including right MNS at the wrist at 110% motor threshold (MT; 110% MNS condition), right MNS at the index finger (sensory digit nerve stimulation [DNS]) with stimulus intensity approximately 110% MNS (DNS condition), and right MNS at the wrist at 90% MT (90% MNS condition) were applied. PES was administered in a 4 s ON and 6 s OFF cycle for 20 min at 30 Hz. In Experiment 1 (n = 15), MEPs were recorded from the right abductor pollicis brevis (APB) before (baseline) and after PES. In Experiment 2 (n = 15), M- and F-waves were recorded from the right APB. Stimulation at 110% MNS at the wrist evoking muscle contraction increased MEP amplitudes after PES compared with those at baseline, whereas DNS at the index finger and 90% MNS at the wrist not evoking muscle contraction decreased MEP amplitudes after PES. M- and F-waves, which reflect spinal cord or muscular and neuromuscular junctions, did not change following PES. These results suggest that muscle contraction and concomitant muscle/joint afferent inputs specifically enhance M1 excitability.

  11. Presence and Absence of Muscle Contraction Elicited by Peripheral Nerve Electrical Stimulation Differentially Modulate Primary Motor Cortex Excitability

    PubMed Central

    Sasaki, Ryoki; Kotan, Shinichi; Nakagawa, Masaki; Miyaguchi, Shota; Kojima, Sho; Saito, Kei; Inukai, Yasuto; Onishi, Hideaki

    2017-01-01

    Modulation of cortical excitability by sensory inputs is a critical component of sensorimotor integration. Sensory afferents, including muscle and joint afferents, to somatosensory cortex (S1) modulate primary motor cortex (M1) excitability, but the effects of muscle and joint afferents specifically activated by muscle contraction are unknown. We compared motor evoked potentials (MEPs) following median nerve stimulation (MNS) above and below the contraction threshold based on the persistence of M-waves. Peripheral nerve electrical stimulation (PES) conditions, including right MNS at the wrist at 110% motor threshold (MT; 110% MNS condition), right MNS at the index finger (sensory digit nerve stimulation [DNS]) with stimulus intensity approximately 110% MNS (DNS condition), and right MNS at the wrist at 90% MT (90% MNS condition) were applied. PES was administered in a 4 s ON and 6 s OFF cycle for 20 min at 30 Hz. In Experiment 1 (n = 15), MEPs were recorded from the right abductor pollicis brevis (APB) before (baseline) and after PES. In Experiment 2 (n = 15), M- and F-waves were recorded from the right APB. Stimulation at 110% MNS at the wrist evoking muscle contraction increased MEP amplitudes after PES compared with those at baseline, whereas DNS at the index finger and 90% MNS at the wrist not evoking muscle contraction decreased MEP amplitudes after PES. M- and F-waves, which reflect spinal cord or muscular and neuromuscular junctions, did not change following PES. These results suggest that muscle contraction and concomitant muscle/joint afferent inputs specifically enhance M1 excitability. PMID:28392766

  12. Region-related modular nerve-dependent motor activity in anorectum--cholinergic and nitrergic contribution to rat model.

    PubMed

    Stavreva, Galya; Radomirov, Radomir

    2012-01-01

    Disturbances of enteric nerve-mediated anorectal evacuation mechanisms have medical and social impact. The study aimed at further eliciting the contribution of cholinergic and nitrergic neurotransmission systems to modular nerve networks in different regions of Wistar rat anorectum. Electrical field stimulation (EFS, 0.8 ms, 40 V, 2, 5 or 10 Hz, 20 s), computerized mechanographic on-line setup and drugs were used to evaluate the motor responses of isolated rings from circular muscle of rectum (proximal, middle, and distal part), internal anal sphincter, and anal canal. Twitch-like frequency-dependent contractions, more pronounced in rectal preparations, characterized the modular motor responses of rectal circular muscle rings and anal canal. Depending on the frequency of stimulation, the motor activity of internal anal sphincter varied from deep long-lasting relaxation to initial short-lasting relaxation, followed by a contraction. Electrically-evoked responses of anorectal preparations were tetrodotoxin (0.1 microM)-sensitive. In the presence of atropine (0.3 microM) the contractions of rectal rings decreased, relaxation of internal anal sphincter increased and inhibition of the contractions of the anal canal occurred, followed by relaxation. During atropine treatment, NG-nitro-L-arginine (0.5 microM) increased the contractile responses and suppressed internal anal sphincter relaxations. L-arginine (0.5 microM) decreased the contractions and extended the relaxations of internal anal sphincter and anal canal. Our results suggest that cholinergic and nitrergic systems are not equally involved in modular nerve networks of various regions of anorectum. Cholinergic transmission is more expressed in distal rectum, underlying its contractile potency, while nitric oxide-dependent transmission(s) control the relaxation ability of the internal anal sphincter and anal canal.

  13. Longitudinal changes of nerve conduction velocity, distal motor latency, compound motor action potential duration, and skin temperature during prolonged exposure to cold in a climate chamber.

    PubMed

    Maetzler, Walter; Klenk, Jochen; Becker, Clemens; Zscheile, Julia; Gabor, Kai-Steffen; Lindemann, Ulrich

    2012-09-01

    Changes of nerve conduction velocity (NCV), distal motor latency (DML), compound motor action potential (CMAP) duration, and skin temperature with regard to cold have been investigated by use of ice packs or cold water baths, but not after cooling of environmental temperature which has higher ecological validity. The aim of this study was to investigate these parameters during cooled room temperature. NCV, DML, and CMAP duration of the common fibular nerve, and skin temperature were measured in 20 healthy young females during exposure to 15°C room temperature, coming from 25°C room. We found that NCV decreased and DML increased linearly during 45 min observation time, in contrast to CMAP duration and skin temperature which changes followed an exponential curve. To the best of our knowledge, this is the first study investigating changes of these parameters during exposure to environmental cold. The results may pilot some new hypotheses and studies on physiological and pathological changes of the peripheral nervous system and skin to environmental cold, e.g., in elderly with peripheral neuropathies.

  14. Effect of eicosapentaenoic acids-rich fish oil supplementation on motor nerve function after eccentric contractions.

    PubMed

    Ochi, Eisuke; Tsuchiya, Yosuke; Yanagimoto, Kenichi

    2017-01-01

    This study investigated the effect of supplementation with fish oil rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on the M-wave latency of biceps brachii and muscle damage after a single session of maximal elbow flexor eccentric contractions (ECC). Twenty-one men were completed the randomized, double-blind, placebo-controlled, and parallel-design study. The subjects were randomly assigned to the fish oil group (n = 10) or control group (n = 11). The fish oil group consumed eight 300-mg EPA-rich fish oil softgel capsules (containing, in total, 600 mg EPA and 260 mg DHA) per day for 8 weeks before the exercise, and continued this for a further 5 days. The control group consumed an equivalent number of placebo capsules. The subjects performed six sets of ten eccentric contractions of the elbow flexors using a dumbbell set at 40% of their one repetition maximum. M-wave latency was assessed as the time taken from electrical stimulation applied to Erb's point to the onset of M-wave of the biceps brachii. This was measured before and immediately after exercise, and then after 1, 2, 3, and 5 days. Changes in maximal voluntary isometric contraction (MVC) torque, range of motion (ROM), upper arm circumference, and delayed onset muscle soreness (DOMS) were assessed at the same time points. Compared with the control group, M-wave latency was significantly shorter in the fish oil group immediately after exercise (p = 0.040), MVC torque was significantly higher at 1 day after exercise (p = 0.049), ROM was significantly greater at post and 2 days after exercise (post; p = 0.006, day 2; p = 0.014), and there was significantly less delayed onset muscle soreness at 1 and 2 days after exercise (day 1; p = 0.049, day 2; p = 0.023). Eight weeks of EPA and DHA supplementation may play a protective role against motor nerve function and may attenuate muscle damage after eccentric contractions. This trial was registered on July 14th 2015 (https

  15. Perineural Administration of Dexmedetomidine in Combination with Bupivacaine Enhances Sensory and Motor Blockade in Sciatic Nerve Block without Inducing Neurotoxicity in the Rat

    PubMed Central

    Brummett, Chad M.; Norat, Mary A.; Palmisano, John M.; Lydic, Ralph

    2008-01-01

    Background The present study was designed to test the hypothesis that high-dose dexmedetomidine added to local anesthetic would increase the duration of sensory and motor blockade in a rat model of sciatic nerve blockade without causing nerve damage. Methods Thirty-one adult Sprague Dawley rats received bilateral sciatic nerve blocks with either 0.2 ml of 0.5% bupivacaine and 0.5% bupivacaine plus 0.005% dexmedetomidine in the contralateral leg, or 0.2 ml of 0.005% dexmedetomidine and normal saline in the contralateral leg. Sensory and motor function were assessed by a blinded investigator every 30 minutes until the return of normal sensory and motor function. Sciatic nerves were harvested at either 24 hours or 14 days after injection and analyzed for perineural inflammation and nerve damage. Results High-dose dexmedetomidine added to bupivacaine significantly enhanced the duration of sensory and motor blockade. Dexmedetomidine alone did not cause significant motor or sensory block. All of the nerves analyzed had normal axons and myelin at 24 hours and 14 days. Bupivacaine plus dexmedetomidine showed less perineural inflammation at 24 hours than the bupivacaine group when compared with the saline control. Conclusion The finding that high-dose dexmedetomidine can safely improve the duration of bupivacaine-induced antinociception following sciatic nerve blockade in rats is an essential first step encouraging future studies in humans. The dose of dexmedetomidine used in this study may exceed the sedative safety threshold in humans and could cause prolonged motor blockade, therefore future work with clinically relevant doses is necessary. PMID:18719449

  16. Sciatic nerve grafting and inoculation of FGF-2 promotes improvement of motor behavior and fiber regrowth in rats with spinal cord transection.

    PubMed

    Guzen, Fausto Pierdoná; Soares, Joacil Germano; de Freitas, Leandro Moura; Cavalcanti, José Rodolfo Lopes de Paiva; Oliveira, Francisco Gilberto; Araújo, John Fontenele; Cavalcante, Jeferson de Souza; Cavalcante, Judney Cley; do Nascimento, Expedito Silva; de Oliveira Costa, Miriam Stela Maris

    2012-01-01

    Failure of severed adult central nervous system (CNS) axons to regenerate could be attributed with a reduced intrinsic growing capacity. Severe spinal cord injury is frequently associated with a permanent loss of function because the surviving neurons are impaired to regrow their fibers and to reestablish functional contacts. Peripheral nerves are known as good substrate for bridging CNS trauma with neurotrophic factor addition. We evaluated whether fibroblastic growth factor 2 (FGF-2) placed in a gap promoted by complete transection of the spinal cord may increase the ability of sciatic nerve graft to enhance motor recovery and fibers regrow. We used a complete spinal cord transection model. Rats received a 4 mm-long gap at low thoracic level and were repaired with saline (control) or fragment of the sciatic nerve (Nerve) or FGF-2 was added to nerve fragment (Nerve+FGF-2) to the grafts immediately after complete transection. The hind limbs performance was evaluated weekly for 8 weeks by using motor behavior score (BBB) and sensorimotor tests-linked to the combined behavior score (CBS), which indicate the degree of the motor improvement and the percentage of functional deficit, respectively. Neuronal plasticity were evaluated at the epicenter of the injury using MAP-2 and GAP-43 expression. Spinal cord treatment with sciatic nerve and sciatic nerve plus FGF-2 allowed recovery of hind limb movements compared to control, manifested by significantly higher behavioral scores. Higher amounts of MAP-2 and GAP-43 immunoreactive fibers were found in the epicenter of the graft when FGF-2 was added. FGF-2 added to the nerve graft favored the motor recovery and fiber regrowth. Thus, these results encourage us to explore autologous transplantation as a novel and promising cell therapy for treatment of spinal cord lesion.

  17. Identification of gangliosides recognized by IgG anti-GalNAc-GD1a antibodies in bovine spinal motor neurons and motor nerves.

    PubMed

    Yoshino, Hiide; Ariga, Toshio; Suzuki, Akemi; Yu, Robert K; Miyatake, Tadashi

    2008-08-28

    The presence of immunoglobulin G (IgG)-type antibodies to the ganglioside, N-acetylgalactosaminyl GD1a (GalNAc-GD1a), is closely associated with the pure motor type of Guillain-Barré syndrome (GBS). In the present study, we isolated disialogangliosides from the motor neurons and motor nerves of bovine spinal cords by DEAE-Sephadex column chromatography. The disialoganglioside fraction contained GD1a, GD2, GD1b, and three gangliosides, designated X1, X2 and X3. Serum from a patient with axonal GBS with IgG anti-GalNAc-GD1a antibody yielded positive immunostaining with X1, X2, and X3. When isolated by preparative thin-layer chromatography (TLC), X1 migrated at the same position as GalNAc-GD1a from Tay-Sachs brain, suggesting that X1 is GalNAc-GD1a containing N-acetylneuraminic acid (NeuAc). TLC of isolated X2 revealed that it migrated between GD1a and GD2. On the other hand, X3 had a migratory rate on TLC between and GD1b and GT1b. Since both X2 and X3 were recognized by IgG anti-GalNAc-GD1a antibody, the results suggest that X2 is a GalNAc-GD1a species containing a mixture containing a NeuAc-and an N-glycolylneuraminic acid (NeuGc) species, and X3 is a GalNAc-GD1a species with two NeuGc. This evidence indicating the specific localization of GalNAc-GD1a and its isomers in spinal motor neurons should be useful in elucidating the pathogenic role of IgG anti-GalNAc-GD1a antibody in pure motor-type GBS.

  18. Convection enhanced drug delivery of BDNF through a microcannula in a rodent model to strengthen connectivity of a peripheral motor nerve bridge model to bypass spinal cord injury.

    PubMed

    Martin Bauknight, W; Chakrabarty, Samit; Hwang, Brian Y; Malone, Hani R; Joshi, Shailendra; Bruce, Jeffrey N; Sander Connolly, E; Winfree, Christopher J; Cunningham, Miles G; Martin, John H; Haque, Raqeeb

    2012-04-01

    Models employing peripheral nerve to bypass spinal cord injury (SCI), although highly promising, may benefit from improved nerve regeneration and motor bridge connectivity. Recent studies have demonstrated that neuronal growth factor-induced enhancement of endogenous neurorestoration may improve neuronal connectivity after severe neurologic injury, particularly if delivered intraparenchymally with zero-order kinetics. We sought to investigate the effect of convection-enhanced delivery of brain-derived neurotrophic factor (BDNF), a neuronal growth factor, on the connectivity of a peripheral motor-nerve bridge in a rodent model using electrophysiology and immunohistochemistry (IHC). Spinal cords of 29 female rats were hemisected at the L1 level. Ipsilateral T13 peripheral nerves were dissected from their muscular targets distally, while maintaining their connections with the spinal cord, and inserted caudal to the injury site to establish the nerve bridge. A microcannula attached to a six-week mini-osmotic pump was used to deliver either BDNF (n=12), saline (n=14), or fluorescein dye (n=3) directly into the spinal cord parenchyma between the site of nerve insertion and hemisection to a depth of 2mm into the area of the lateral motor pool. After four weeks, gastrocnemius muscle activation was assessed electromyographically in five animals from each group. Spinal cords were harvested and analyzed with IHC for cannula-associated injury, and nerve regeneration. Strength of motor bridge connection was illustrated by electrophysiology data. Intraspinal BDNF levels were measured using enzyme-linked immunosorbent assay. IHC revealed increased intraparenchymal BDNF concentration at the nerve bridge insertion site with evidence of minimal trauma from cannulation. BDNF infusion resulted in stronger connections between bridge nerves and spinal motor axons. Bridge nerve electrical stimulation in BDNF-treated rats evoked hind leg electromyogram responses of shorter latency and

  19. Ocular nerve growth factor administration counteracts the impairment of neural precursor cell viability and differentiation in the brain subventricular area of rats with streptozotocin-induced diabetes.

    PubMed

    Tirassa, Paola; Maccarone, Mattia; Carito, Valentina; De Nicolò, Sara; Fiore, Marco

    2015-05-01

    The ocular administration of nerve growth factor (NGF) as eye drops (oNGF) has been shown to exert protective effects in forebrain-injured animal models, including adult diabetes induced by a single injection of streptozotocin (STZ) (60 mg/kg body weight). This type 1 diabetes model was used in this study to investigate whether oNGF might extend its actions on neuronal precursors localised in the subventricular zone (SVZ). NGF or saline was administrated as eye drops twice daily for 2 weeks in rats with STZ-induced diabetes and healthy control rats. The expression of mature and precursor NGF and the NGF receptors, tropomyosin-related kinase A and neurotrophin receptor p75, and the levels of DNA fragmentation were analysed by ELISA and western blotting. Incorporation of bromodeoxyuridine was used to trace newly formed cells. Nestin, polysialylated neuronal cell adhesion molecule (PSA-NCAM), doublecortin (DCX) and glial fibrillary acidic protein antibodies were used to identify the SVZ cells by confocal microscopy. It was found that oNGF counteracts the STZ-induced cell death and the alteration of mature/pro-NGF expression in the SVZ. It also affects the survival and differentiation of SVZ progenitors. In particular, oNGF counteracts the reduction in the number of cells expressing PSA-NCAM/DCX (neuroblast type A cells) and the related reductions in the number and distribution of nestin/DCX-positive cells (C-type cells), or glia-committed cells (type B cells), observed in the SVZ of diabetic rats. These findings show that oNGF treatment counteracts the effect of type 1 diabetes on neuronal precursors in the SVZ, and further support the neuroprotective and reparative role of oNGF in the brain.

  20. [Steroid induced ocular hypertension and glaucoma].

    PubMed

    Călugăru, D; Călugăru, M

    2009-01-01

    Steroid induced ocular hypertension and glaucoma represent iatrogenic changes of pharmacogenic nature. They are mainly due to exogenous steroids following ocular periocular, intravitreal and systemic administration. Elevated ocular pressure is brought about by structural trabecular changes as well as obstruction of the outflow ways of the aqueous humor localized within the trabecular juxtacanalicular area. Although mostly raised ocular pressure spontaneously descends to basal values after ceasing the steroid therapy, progressive optic nerve damages and glaucomatous visual field defects may occur. Therapy of steroid induced ocular hypertension and glaucoma is similar to that of ocular hypertension and primary open-angle glaucoma.

  1. Novel cryoneurolysis device for the treatment of sensory and motor peripheral nerves.

    PubMed

    Ilfeld, Brian M; Preciado, Jessica; Trescot, Andrea M

    2016-08-01

    Cryoneurolysis is the direct application of low temperatures to reversibly ablate peripheral nerves to provide pain relief. Recent development of a handheld cryoneurolysis device with small gauge probes and an integrated skin warmer broadens the clinical applications to include treatment of superficial nerves, further enabling treatments for pre-operative pain, post-surgical pain, chronic pain, and muscle movement disorders. Cryoneurolysis is the direct application of cold temperatures to a peripheral nerve, resulting in reversible ablation due to Wallerian degeneration and nerve regeneration. Use over the last 50 years attests to a very low incidence of complications and adverse effects. Cryoprobes have traditionally been applied through a surgical incision; but, recent technical advances allow percutaneous administration. A new hand-held device is now approved for use within the United States. Cryoneurolysis has been used to treat postoperative and chronic pain states as well as spasticity. Expert commentary: Changes in the US healthcare system such as a push for the reduction of opioid use and the incorporation of Diagnostic Related Group codes, as well as recent technological advances including a handheld unit that allows for treatment of superficial nerves while protecting the skin from damage, may contribute to the resurgence of cryoneurolysis for the treatment of peripheral nerves.

  2. The ocular motor features of adult-onset alexander disease: a case and review of the literature.

    PubMed

    Pfeffer, Gerald; Abegg, Mathias; Vertinsky, A Talia; Ceccherini, Isabella; Caroli, Francesco; Barton, Jason J S

    2011-06-01

    A 51-year-old Chinese man presented with gaze-evoked nystagmus, impaired smooth pursuit and vestibular ocular reflex cancellation, and saccadic dysmetria, along with a family history suggestive of late-onset autosomal dominant parkinsonism. MRI revealed abnormalities of the medulla and cervical spinal cord typical of adult-onset Alexander disease, and genetic testing showed homozygosity for the p.D295N polymorphic allele in the gene encoding the glial fibrillary acidic protein. A review of the literature shows that ocular signs are frequent in adult-onset Alexander disease, most commonly gaze-evoked nystagmus, pendular nystagmus, and/or oculopalatal myoclonus, and less commonly ptosis, miosis, and saccadic dysmetria. These signs are consistent with the propensity of adult-onset Alexander disease to cause medullary abnormalities on neuroimaging.

  3. Isolated trigeminal nerve palsy with motor involvement as a presenting manifestation of multiple sclerosis in an equatorial region – a case report

    PubMed Central

    2012-01-01

    Introduction Isolated cranial nerve palsies are considered to be an uncommon presenting feature of multiple sclerosis. Involvement of the trigeminal nerve, particularly its motor component as part of a clinically isolated syndrome of multiple sclerosis has rarely been reported in equatorial regions and no cases have been described in Sri Lanka thus far. Case Presentation We report a case of isolated right sided trigeminal nerve palsy (Motor and Sensory) in a 34 year old previously well lady from urban Sri Lanka who was found to have characteristic lesions on Magnetic Resonance Imaging highly suggestive of multiple sclerosis. Conclusions Multiple sclerosis should be considered in the differential diagnosis of patients who present with isolated cranial nerve palsies. Clinicians should have a high index of suspicion when evaluating such patients especially in low prevalence regions close to the equator. Early recognition and treatment of such a “Clinically Isolated Syndrome” may prevent early relapse. PMID:22647398

  4. Polychlorinated biphenyl poisoning: correlation of sensory and motor nerve conduction, neurologic symptoms, and blood levels of polychlorinated biphenyls, quaterphenyls, and dibenzofurans

    SciTech Connect

    Chen, R.C.; Tang, S.Y.; Miyata, H.; Kashimoto, T.; Chang, Y.C.; Chang, K.J.; Tung, T.C.

    1985-08-01

    In 1979 in Taiwan, more than 2000 people were poisoned with rice cooking oil contaminated with polychlorinated biphenyls (PCB). One hundred ten patients were studied within one year of the exposure. The blood PCB levels were 39.3 +/- 16.6 ppb. The blood levels of the PCB derivatives, polychlorinated quaterphenyls (PCQ) and polychlorinated dibenzofurans (PCDF), were 8.6 +/- 4.8 and 0.076 +/- 0.038 ppb, respectively. Both the sensory and motor nerve conduction velocities (NCV) of the patients were significantly lower than the control. Abnormal slowing of sensory NCV was found in 43.6% and abnormal slowing of motor NCV was seen in 21.8%. Patients who had higher PCQ blood levels has significantly slower median nerve sensory NCV than those with lower PCQ levels. Patients with higher PCB blood levels had significantly slower peroneal nerve motor NCV than those with lower PCB levels.

  5. Tibial motor nerve conduction studies: an investigation into the mechanism for amplitude drop of the proximal evoked response.

    PubMed

    Barkhaus, Paul E; Kincaid, John C; Nandedkar, Sanjeev D

    2011-11-01

    The amplitude of the compound muscle action potential (CMAP) of abductor hallucis (AH) shows the largest drop with proximal stimulation of any routinely studied motor nerves. The cause has not been established. Four experiments of tibial motor nerve conduction in several healthy control subjects were performed using far-field recordings, collision, H-reflex, and intramuscular recordings of foot muscles. The proximal CMAP showed a mean peak-peak amplitude of 66% (range 57-79%) compared with the distal response. Collision and H-reflex recordings in AH did not show evidence of a contribution from the tibial-innervated calf muscle. Needle electrode recordings of CMAPs showed consistently different latencies between different foot muscles. Our experiments indicate that temporal dispersion and phase cancellation between the distal tibial-innervated foot muscles recorded by the E2 (i.e., reference) electrode can explain the drop in amplitude between the proximal and distal tibial evoked CMAP. Copyright © 2011 Wiley Periodicals, Inc.

  6. Pycnogenol efficiency on glycaemia, motor nerve conduction velocity and markers of oxidative stress in mild type diabetes in rats.

    PubMed

    Jankyova, S; Kucera, P; Goldenberg, Z; Yaghi, D; Navarova, J; Kyselova, Z; Stolc, S; Klimas, J; Racanska, E; Matyas, S

    2009-08-01

    The aim of this study was to describe the effects of Pycnogenol at various doses on preprandial and postprandial glucose levels, the levels of thiobarbituric acid reactive substances (TBARs) and N-acetyl-beta-d-glucosaminidase (NAGA) and on motor nerve conduction velocity (MNCV) in streptozotocin (STZ)-induced diabetic rats. Pycnogenol treatment (10, 20, 50 mg/kg body weight (b.w.)/day) lasted for 8 weeks after induction of diabetes. Pycnogenol significantly decreased elevated levels of preprandial glycaemia in treated animals at all doses. At doses of 10 mg/kg b.w./day and 20 mg/kg b.w./day it significantly decreased elevated levels of postprandial glycaemia compared with diabetic non-treated animals. Pycnogenol failed to induce a significant decrease of postprandial glycaemia at a dose of 50 mg/kg b.w./day. Pycnogenol improved significantly the impaired MNCV at doses of 10 and 20 mg/kg b.w./day compared with non-treated animals. The levels of TBARs were elevated in diabetic rats. The levels of NAGA increased gradually despite the treatment. Pycnogenol failed to affect the increased levels of TBARs and NAGA. Pycnogenollowered the elevated levels of glycaemia and reduced the decline in motor nerve conduction velocity in STZ-induced diabetic rats. The effect of Pycnogenol on postprandial glycaemic levels and MNCV was not dose-dependent.

  7. Analysis of activity of motor units in the biceps brachii muscle after intercostal-musculocutaneous nerve transfer.

    PubMed

    Sakuta, Naoki; Sasaki, Sei-Ichi; Ochiai, Naoyuki

    2005-04-01

    We examined respiratory activity of motor units (MUs) in the internal intercostal nerves (IICNs)-transferred biceps brachii muscle (IC-biceps) in cats. MUs of IC-biceps showed respiratory discharges in inspiratory and expiratory phases, and these were enhanced by CO2 inhalation. Narrowing the airway also enhanced inspiratory and expiratory MUs activity. A mechanical load to the thorax immediately enhanced inspiratory MUs activity and weakened expiratory MUs activity. We analyzed the cross-correlation of MUs activity in interchondral muscle and IC-biceps to characterize the respiratory spinal descending inputs to motoneurons. We confirmed the short-term synchronization from interchondral muscles indicating divergence of a single respiratory presynaptic axon to thoracic motoneurons, but could not find synchronization from IC-biceps. The motor axonal conduction velocity (axonal CV) of IC-biceps MUs was lower than that of interchondral muscles. There was no correlation between the respiratory recruitment order of IC-biceps MUs and their axonal CV. These results indicate that IC-biceps shows the respiratory activities and afferent inputs from intercostal muscle spindles in the neighboring segments remain influential on activity of IC-biceps. In addition, the short-term synchronization from IC-biceps could not be found, suggesting that the intercostal nerve transfer alters the respiratory spinal descending inputs to thoracic motoneurons.

  8. Electrical Stimulation of the Vagus Nerve Enhances Cognitive and Motor Recovery following Moderate Fluid Percussion Injury in the Rat

    PubMed Central

    SMITH, DOUGLAS C.; MODGLIN, ARLENE A.; ROOSEVELT, RODNEY W.; NEESE, STEVEN L.; JENSEN, ROBERT A.; BROWNING, RONALD A.; CLOUGH, RICHARD W.

    2006-01-01

    Intermittent, chronically delivered electrical stimulation of the vagus nerve (VNS) is an FDA-approved procedure for the treatment of refractory complex/partial epilepsy in humans. Stimulation of the vagus has also been shown to enhance memory storage processes in laboratory rats and human subjects. Recent evidence suggests that some of these effects of VNS may be due to the activation of neurons in the nucleus locus coeruleus resulting in the release of norepinephrine (NE) throughout the neuraxis. Because antagonism of NE systems has been shown to delay recovery of function following brain damage, it is possible that enhanced release of NE in the CNS may facilitate recovery of function. To evaluate this hypothesis the lateral fluid percussion injury (LFP) model of traumatic brain injury was used and a variety of motor and cognitive behavioral tests were employed to assess recovery in pre-trained stimulated, control, and sham-injured laboratory rats. Two hours following moderate LFP, vagus nerve stimulation (30.0-sec trains of 0.5 mA, 20.0 Hz, biphasic pulses) was initiated. Stimulation continued in each animal’s home cage at 30-min intervals for a period of 14 days, with the exception of brief periods when the animals were disconnected for behavioral assessments. Motor behaviors were evaluated every other day following LFP and tests included beam walk, locomotor placing, and skilled forelimb reaching. In each measure an enhanced rate of recovery and/or level of final performance was observed in the VNS-LFP animals compared to non-stimulated LFP controls. Behavior in the Morris water maze was assessed on days 11–14 following injury. Stimulated LFP animals showed significantly shorter latencies to find the hidden platform than did controls. Despite these behavioral effects, neurohistological examination did not reveal significant differences in lesion extent, density of fluorojade positive neurons, reactive astrocytes or numbers of spared neurons in the CA3

  9. Central regulation of motor cortex neuronal responses to forelimb nerve inputs during precision walking in the cat

    PubMed Central

    Marple-Horvat, D E; Armstrong, D M

    1999-01-01

    The responses of neurones in forelimb motor cortex to impulse volleys evoked by single pulse electrical stimulation (at 1.5 or 2 times the threshold for most excitable nerve fibres) of the superficial radial (SR) and ulnar (UL) nerves of the contralateral forelimb were studied in awake cats both resting quietly and walking on a horizontal ladder. Nerve volley amplitude was monitored by recording the compound action potential elicited by the stimulus. In the resting animal 34/82 (41 %) cells yielded statistically significant responses to SR stimulation, and 20/72 (28 %) responded to UL stimulation. Some responses were confined to or began with an increase in firing probability (‘excitatory’ responses) and others with a decrease in firing (‘inhibitory’ responses), typically including a brief interruption of the spike train (zero rate). Cells responding to both nerves usually yielded responses similar in type. Most (78 %) response onset latencies were less than 30 ms. Responses involved the addition or subtraction of from 3.4 to 0.1 impulses stimulus−1 (most < 1 impulse stimulus−1). The distribution of response sizes was continuous down to the smallest values, i.e. there was no ‘gap’ which would represent a clear separation into ‘responsive’ and ‘unresponsive’ categories. Responses were commonest in the lateral part of the pericruciate cortex, and commoner among pyramidal tract neurones (PTNs) than non-PTNs. During ladder walking most cells generated a rhythmic step-related discharge; in assessing the size of responses to nerve stimulation (20 studied, from 13 cells) this activity was first subtracted. Response onset latencies (90 % < 30 ms) and durations showed little or no change. Although most cells were overall more active than during rest both ‘excitatory’ and ‘inhibitory’ responses in both PTNs and non-PTNs were often markedly reduced in large parts of the step cycle; over some (usually brief) parts responses approached or

  10. Verification of the median-to-ulnar and ulnar-to-median nerve motor fiber anastomosis in the forearm: an electrophysiological study.

    PubMed

    Amoiridis, Georgios; Vlachonikolis, Ioannis G

    2003-01-01

    To estimate the real occurrence of the motor median-to-ulnar nerve anastomosis in the proximal forearm (Martin-Gruber anastomosis, MGA), as its frequency varies between 6 and 44% in the literature and to investigate the incidence of the ulnar-to-median nerve anastomosis in the distal forearm. Compound muscle action potentials (CMAP) recorded over thenar, hypothenar, and first dorsal interosseus muscle on median or ulnar nerve stimulation at wrist and elbow and collision blocks of the median and ulnar nerve were compared in a group of 50 healthy volunteers. Particular precautions were undertaken in order to avoid false positive results due to stimulus spread to the neighboring nerve. Cases of uncertain MGA were classified as either MGA or non-MGA on the basis of posterior probabilities estimated by discriminant analysis. The estimated frequency of MGA was 54% using the potential comparison method and 46% using the collision technique. An ulnar-to-median nerve anastomosis was not found in any subject. While the MGA is very common, the ulnar-to-median nerve anastomosis is a rarity. Standard nerve conduction studies of the median nerve with CMAP recordings solely over thenar will detect less than 14% of MGA cases.

  11. Evaluation of the Predictive Value of Intraoperative Changes in Motor-Evoked Potentials of Caudal Cranial Nerves for the Postoperative Functional Outcome.

    PubMed

    Kullmann, Marcel; Tatagiba, Marcos; Liebsch, Marina; Feigl, Guenther C

    2016-11-01

    The predictive value of changes in intraoperatively acquired motor-evoked potentials (MEPs) of the lower cranial nerves (LCN) IX-X (glossopharyngeal-vagus nerve) and CN XII (hypoglossal nerve) on operative outcomes was investigated. MEPs of CN IX-X and CN XII were recorded intraoperatively in 63 patients undergoing surgery of the posterior cranial fossa. We correlated the changes of the MEPs with postoperative nerve function. For CN IX-X, we found a correlation between the amplitude of the MEP ratio and uvula deviation (P = 0.028) and the amplitude duration of the MEP and gag reflex function (P = 0.027). Patients with an MEP ratio of the glossopharyngeal-vagus amplitude ≤1.47 μV had a 3.4 times increased risk of developing a uvula deviation. Patients with a final MEP duration of the CN IX-X ≤11.6 milliseconds had a 3.6 times increased risk for their gag reflex to become extinct. Our study greatly contributes to the current knowledge of intraoperative MEPs as a predictor for postoperative cranial nerve function. We were able to extent previous findings on MEP values of the facial nerve on postoperative nerve function to 3 additional cranial nerves. Finding reliable predictors for postoperative nerve function is of great importance to the overall quality of life for a patient undergoing surgery of the posterior cranial fossa. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Nerve Stimulation Enhances Task-Oriented Training in Chronic, Severe Motor Deficit After Stroke: A Randomized Trial.

    PubMed

    Carrico, Cheryl; Chelette, Kenneth C; Westgate, Philip M; Powell, Elizabeth; Nichols, Laurie; Fleischer, Anne; Sawaki, Lumy

    2016-07-01

    A sensory-based intervention called peripheral nerve stimulation can enhance outcomes of motor training for stroke survivors with mild-to-moderate hemiparesis. Further research is needed to establish whether this paired intervention can have benefit in cases of severe impairment (almost no active movement). Subjects with chronic, severe poststroke hemiparesis (n=36) were randomized to receive 10 daily sessions of either active or sham stimulation (2 hours) immediately preceding intensive task-oriented training (4 hours). Upper extremity movement function was assessed using Fugl-Meyer Assessment (primary outcome measure), Wolf Motor Function Test, and Action Research Arm Test at baseline, immediately post intervention and at 1-month follow-up. Statistically significant difference between groups favored the active stimulation group on Fugl-Meyer at postintervention (95% confidence interval [CI], 1.1-6.9; P=0.008) and 1-month follow-up (95% CI, 0.6-8.3; P=0.025), Wolf Motor Function Test at postintervention (95% CI, -0.21 to -0.02; P=0.020), and Action Research Arm Test at postintervention (95% CI, 0.8-7.3; P=0.015) and 1-month follow-up (95% CI, 0.6-8.4; P=0.025). Only the active stimulation condition was associated with (1) statistically significant within-group benefit on all outcomes at 1-month follow-up and (2) improvement exceeding minimal detectable change, as well as minimal clinically significant difference, on ≥1 outcomes at ≥1 time points after intervention. After stroke, active peripheral nerve stimulation paired with intensive task-oriented training can effect significant improvement in severely impaired upper extremity movement function. Further confirmatory studies that consider a larger group, as well as longer follow-up, are needed. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02633215. © 2016 American Heart Association, Inc.

  13. Transfer of a motor fascicle from the ulnar nerve to the branch of the radial nerve destined to the long head of the triceps for restoration of elbow extension in brachial plexus surgery: technical case report.

    PubMed

    Flores, Leandro Pretto

    2012-02-01

    Restoration of elbow extension has not been considered of much importance regarding functional outcomes in brachial plexus surgery; however, the flexion of the elbow joint is only fully effective if the motion can be stabilized, what can be achieved solely if the triceps brachii is coactivated. To present a novel nerve transfer of a healthy motor fascicle from the ulnar nerve to the nerve of the long head of the triceps to restore the elbow extension function in brachial plexus injuries involving the upper and middle trunks. Case 1 is a 32-year-old man sustaining a right brachial extended upper plexus injury in a motorcycle accident 5 months before admission. The computed tomography myelogram demonstrated avulsion of the C5 and C6 roots. Case 2 is a 24-year-old man who sustained a C5-C7 injury to the left brachial plexus in a traffic accident 4 months before admission. Computed tomography myelogram demonstrated signs of C6 and C7 root avulsion. The technique included an incision at the medial border of the biceps, in the proximal third of the involved arm, followed by identification of the ulnar nerve, the radial nerve, and the branch to the long head of the triceps. The proximal stump of a motor fascicle from the ulnar nerve was sutured directly to the distal stump of the nerve of the long head of the triceps. Techniques to restore elbow flexion and shoulder abduction were applied in both cases. Triceps strength Medical Research Council M4 grade was obtained in both cases. The attempted nerve transfer was effective for restoration of elbow extension in primary brachial plexus surgery; however, it should be selected only for cases in which other reliable donor nerves were used to restore elbow flexion.

  14. A functional model and simulation of spinal motor pools and intrafascicular recordings of motoneuron activity in peripheral nerve

    PubMed Central

    Abdelghani, Mohamed N.; Abbas, James J.; Horch, Kenneth W.; Jung, Ranu

    2014-01-01

    Decoding motor intent from recorded neural signals is essential for the development of effective neural-controlled prostheses. To facilitate the development of online decoding algorithms we have developed a software platform to simulate neural motor signals recorded with peripheral nerve electrodes, such as longitudinal intrafascicular electrodes (LIFEs). The simulator uses stored motor intent signals to drive a pool of simulated motoneurons with various spike shapes, recruitment characteristics, and firing frequencies. Each electrode records a weighted sum of a subset of simulated motoneuron activity patterns. As designed, the simulator facilitates development of a suite of test scenarios that would not be possible with actual data sets because, unlike with actual recordings, in the simulator the individual contributions to the simulated composite recordings are known and can be methodically varied across a set of simulation runs. In this manner, the simulation tool is suitable for iterative development of real-time decoding algorithms prior to definitive evaluation in amputee subjects with implanted electrodes. The simulation tool was used to produce data sets that demonstrate its ability to capture some features of neural recordings that pose challenges for decoding algorithms. PMID:25452711

  15. Probabilistic secretion of quanta at somatic motor-nerve terminals: the fusion-pore model, quantal detection and autoinhibition.

    PubMed

    Thomson, P C; Lavidis, N A; Robinson, J; Bennett, M R

    1995-08-29

    The probability of detecting first, second, and later quanta secreted at release sites of a motor-nerve terminal during the early release period following a nerve impulse has been addressed. The possibility that early quantal release autoinhibits later quantal release during this period has also been ascertained. In this investigation, a model for the secretion of a quantum at a release site is developed in which, following the influx and diffusion of calcium ions to a release site protein associated with synaptic vesicles, kappa steps of association of the ions with the protein then occur at rate alpha. The release site protein then undergoes a conformational change which may not go on to completion if calcium ions dissociate from the protein at rate gamma. If this process does reach completion then a fusion-pore between the vesicle and the presynaptic membrane is created; this happens at rate delta. Key assumptions of this fusion-pore model are that the quantal secretions from each site are independent of each other, and that there is a large number of vesicles, each with a small probability of secretion, so that the number of secretions is Poisson in nature. These assumptions allow analytical expressions to be obtained for predicting the times at which first, second and later quanta are secreted during the early release period following an impulse. To test the model, experiments were performed in which the times of first, second and later quantal releases were determined at discrete regions along the length of visualized motor-terminal branches in toad (Bufo marinus) muscles. Estimates of model rate constants and of kappa from the times for first quantal secretions failed to give satisfactory predictions of the observed times of later secretions. Therefore, either the model fails, or the procedure used for detecting later quantal events as a consequence of their being masked by earlier quantal events is inadequate. To solve this detection problem, a two

  16. Remodelling of motor nerve terminals in demyelinating axons of periaxin null mutant mice

    PubMed Central

    Court, Felipe A; Brophy, Peter J; Ribchester, Richard R

    2015-01-01

    Myelin formation around axons increases nerve conduction velocity and regulates phenotypic characteristics of the myelinated axon. In the peripheral nervous system, demyelinating forms of hereditary Charcot-Marie-Tooth (CMT) diseases, due to Schwann-cell intrinsic molecular defects, leads to reduced nerve conduction velocity and changes in the axonal phenotype. Several mouse models of CMT diseases have been generated, allowing the study of consequences of demyelination in peripheral nerve fibres. Nevertheless, the effect of demyelination at the level of the neuromuscular synapse has been largely overlooked. Here we show that in the periaxin knock-out mice, a model of CMT condition, neuromuscular junctions develop profound morphological changes in pre-terminal region of motoraxons. These changes include extensive preterminal branches which originate in demyelinated regions of the nerve fibre and axonal swellings associated with residually-myelinated regions of the fibre. Using intracellular recording from muscle fibres we detected asynchronous failure of action potential transmission at high but not low stimulation frequencies, a phenomenon consistent with branch point failure. Taken together, our morphological and electrophysiological findings suggest that preterminal branching due to segmental demyelination near the neuromuscular synapse in periaxin KO mice may underlie phenotypic disabilities present in this mouse model of CMT disease. These results opens a new avenue of research in order to understand the cellular changes responsible for clinical disabilities in demyelinating conditions. PMID:18205176

  17. Genetically encoded pH-indicators reveal activity-dependent cytosolic acidification of Drosophila motor nerve termini in vivo

    PubMed Central

    Rossano, Adam J; Chouhan, Amit K; Macleod, Gregory T

    2013-01-01

    All biochemical processes, including those underlying synaptic function and plasticity, are pH sensitive. Cytosolic pH (pHcyto) shifts are known to accompany nerve activity in situ, but technological limitations have prevented characterization of such shifts in vivo. Genetically encoded pH-indicators (GEpHIs) allow for tissue-specific in vivo measurement of pH. We expressed three different GEpHIs in the cytosol of Drosophila larval motor neurons and observed substantial presynaptic acidification in nerve termini during nerve stimulation in situ. SuperEcliptic pHluorin was the most useful GEpHI for studying pHcyto shifts in this model system. We determined the resting pH of the nerve terminal cytosol to be 7.30 ± 0.02, and observed a decrease of 0.16 ± 0.01 pH units when the axon was stimulated at 40 Hz for 4 s. Realkalinization occurred upon cessation of stimulation with a time course of 20.54 ± 1.05 s (τ). The chemical pH-indicator 2′,7′-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein corroborated these changes in pHcyto. Bicarbonate-derived buffering did not contribute to buffering of acid loads from short (≤4 s) trains of action potentials but did buffer slow (∼60 s) acid loads. The magnitude of cytosolic acid transients correlated with cytosolic Ca2+ increase upon stimulation, and partial inhibition of the plasma membrane Ca2+-ATPase, a Ca2+/H+ exchanger, attenuated pHcyto shifts. Repeated stimulus trains mimicking motor patterns generated greater cytosolic acidification (∼0.30 pH units). Imaging through the cuticle of intact larvae revealed spontaneous pHcyto shifts in presynaptic termini in vivo, similar to those seen in situ during fictive locomotion, indicating that presynaptic pHcyto shifts cannot be dismissed as artifacts of ex vivo preparations. PMID:23401611

  18. Single fibre motor evoked potentials to brain, spinal roots and nerve stimulation. Comparisons of the 'central' and 'peripheral' response jitter to magnetic and electric stimuli.

    PubMed

    Zarola, F; Caramia, M D; Paradiso, C; Mariorenzi, R; Martino, G; Traversa, R; Rossini, P M

    1989-08-28

    Single fibre motor evoked potentials to magnetic and electric non-invasive stimulation of brain, spinal cord and peripheral nerve were recorded in 8 healthy volunteers. The 'central motor jitter' and the 'peripheral motor jitter' were respectively calculated and a comparison between the magnetic and electric modalities was made. The highest degree of latency variability was observed for both magnetic and electric central motor jitter, whilst the peripheral motor jitter to nerve stimulation was as low as the neuromuscular one (range 16-60 microsecond). The magnetic 'central motor jitter' (range 94-1024 microsecond) was much larger than the electric one (range 55-280 microsecond), which was in the order of jitter calculated on H-reflex studies; moreover, the former was organized in a bi- or trimodal distribution. On the contrary, no significant differences were observed between the two modalities when the jitter to nerve stimulation was taken into account. Possible contributions of corticocortical circuitries containing several synaptic interruptions during magnetic as opposed to electric transcranial stimulation, is discussed.

  19. Nestin-expressing stem cells from the hair follicle can differentiate into motor neurons and reduce muscle atrophy after transplantation to injured nerves.

    PubMed

    Liu, Fang; Zhang, Chuansen; Hoffman, Robert M

    2014-02-01

    We have previously shown that nestin-expressing hair follicle stem cells from the mouse and human are multipotent and can differentiate into many cell types, including neurons and glial cells. The nestin-expressing hair follicle stem cells can effect nerve and spinal cord repair upon transplantation in mouse models. In the present study, nestin-expressing hair follicle stem cells expressing red fluorescent protein (RFP) were induced by retinoic acid and fetal bovine serum to differentiate and then transplanted together with Matrigel into the transected distal sciatic or tibial nerve stump of transgenic nude mice ubiquitously expressing green fluorescent protein (GFP). Control mice were transplanted with Matrigel only. The transplanted cells appeared neuron like, with large round nuclei and long extensions. Immunofluorescence staining showed that some of the transplanted cells in the distal nerve stump expressed the neuron marker Tuj1 as well as motor neuron markers Isl 1/2 and EN1. These transplanted cells contacted each other as well as host nerve fibers. Two weeks post-transplantation, nerve fibers in the distal sciatic nerve stump of the transplanted mice had greater expression of motor neuron markers and neurotrophic factor-3 than those in the Matrigel-only transplanted mice. Muscle fiber areas in the nestin-expressing stem cell plus Matrigel-transplanted animals were much bigger than that in the Matrigel-only transplanted animals after 4 weeks. The present results suggest that transplanted nestin-expressing hair follicle stem cells can differentiate into motor neurons and reduce muscle atrophy after sciatic nerve transection. This study demonstrates a new and accessible neuron source to reduce muscle atrophy after nerve injury.

  20. Regulation of synaptic vesicles pools within motor nerve terminals during short-term facilitation and neuromodulation.

    PubMed

    Logsdon, S; Johnstone, A F M; Viele, K; Cooper, R L

    2006-02-01

    The reserve pool (RP) and readily releasable pool (RRP) of synaptic vesicles within presynaptic nerve terminals were physiologically differentiated into distinctly separate functional groups. This was accomplished in glutamatergic nerve terminals by blocking the glutamate transporter with dl-threo-beta-benzyloxyaspartate (TBOA; 10 microM) during electrical stimulation with either 40 Hz of 10 pulses within a train or 20- or 50-Hz continuous stimulation. The 50-Hz continuous stimulation decreased the excitatory postsynaptic potential amplitude 60 min faster than for the 20-Hz continuous stimulation in the presence of TBOA (P < 0.05). There was no significant difference between the train stimulation and 20-Hz continuous stimulation in the run-down time in the presence of TBOA. After TBOA-induced synaptic depression, the excitatory postsynaptic potentials were rapidly (<1 min) revitalized by exposure to serotonin (5-HT, 1 microM) in every preparation tested (P < 0.05). At this glutamatergic nerve terminal, 5-HT promotes an increase probability of vesicular docking and fusion. Quantal recordings made directly at nerve terminals revealed smaller quantal sizes with TBOA exposure with a marked increase in quantal size as well as a continual appearance of smaller quanta upon 5-HT treatment after TBOA-induced depression. Thus 5-HT was able to recruit vesicles from the RP that were not rapidly depleted by acute TBOA treatment and electrical stimulation. The results support the notion that the RRP is selectively activated during rapid electrical stimulation sparing the RP; however, the RP can be recruited by the neuromodulator 5-HT. This suggests at least two separate kinetic and distinct regulatory paths for vesicle recycling within the presynaptic nerve terminal.

  1. Morphometric evaluation of changes with time in optic disc structure and thickness of retinal nerve fibre layer in chronic ocular hypertensive monkeys.

    PubMed

    Shimazawa, Masamitsu; Tomita, Goji; Taniguchi, Takazumi; Sasaoka, Masaaki; Hara, Hideaki; Kitazawa, Yoshiaki; Araie, Makoto

    2006-03-01

    We examined the time course of changes in optic disc structure by means of a scanning laser ophthalmoscope (Heidelberg Retina Tomograph, HRT) in ocular hypertensive (experimental glaucoma) monkeys, and clarified the relationships between the histological RNFL thickness and HRT parameters. Further, the time course of changes in retinal nerve fiber layer (RNFL) thickness in individual eyes was measured using a scanning laser polarimeter with fixed corneal polarization compensator (GDx FCC). In the present study, two separate experiments were carried out. A chronic intraocular pressure (IOP) elevation was induced by laser trabeculoplasty in the left eye in 11 cynomolgus monkeys. In Experiment 1, the HRT and GDx parameters were measured 12 weeks after the laser treatment in 10 eyes in five monkeys. In Experiment 2, the time course of changes in the HRT and GDx parameters was examined before and 1, 3, 4, 5, 6, 8, 10, 12, 14, and 16 weeks after the laser treatment in 12 eyes in six monkeys. The retardation values (thickness parameters) obtained from the GDx were used to derive thickness and ratio parameters in the superior, inferior, nasal and temporal quadrants. Ratio parameters were expressed as a ratio of superior and inferior quadrant to nasal quadrant. After the last measurements, each eye was enucleated, and retinal cross sections were prepared for histological analysis. In the left (hypertensive) eyes, IOP was persistently elevated throughout the observation periods in both Experiments 1 and 2. In the HRT measurements in Experiment 1, seven out of eight global topographic parameters (exception, disc area) were statistically different between the hypertensive and control eyes 12 weeks after the laser treatment. In Experiment 2, the HRT parameters changed in a time-dependent manner, but each of them almost plateaued at about 4 weeks after the laser treatment. Significant correlations were seen between the histological mean RNFL thickness at 1.5 disc diameters from

  2. Rapid-rate paired associative stimulation of the median nerve and motor cortex can produce long-lasting changes in motor cortical excitability in humans

    PubMed Central

    Quartarone, Angelo; Rizzo, Vincenzo; Bagnato, Sergio; Morgante, Francesca; Sant'Angelo, Antonino; Girlanda, Paolo; Roman Siebner, Hartwig

    2006-01-01

    Repetitive transcranial magnetic stimulation (rTMS) or repetitive electrical peripheral nerve stimulation (rENS) can induce changes in the excitability of the human motor cortex (M1) that is often short-lasting and variable, and occurs only after prolonged periods of stimulation. In 10 healthy volunteers, we used a new repetitive paired associative stimulation (rPAS) protocol to facilitate and prolong the effects of rENS and rTMS on cortical excitability. Sub-motor threshold 5 Hz rENS of the right median nerve was synchronized with submotor threshold 5 Hz rTMS of the left M1 at a constant interval for 2 min. The interstimulus interval (ISI) between the peripheral stimulus and the transcranial stimulation was set at 10 ms (5 Hz rPAS10ms) or 25 ms (5 Hz rPAS25ms). TMS was given over the hot spot of the right abductor pollicis brevis (APB) muscle. Before and after rPAS, we measured the amplitude of the unconditioned motor evoked potential (MEP), intracortical inhibition (ICI) and facilitation (ICF), short- and long-latency afferent inhibition (SAI and LAI) in the conditioned M1. The 5 Hz rPAS25ms protocol but not the 5 Hz rPAS10ms protocol caused a somatotopically specific increase in mean MEP amplitudes in the relaxed APB muscle. The 5 Hz rPAS25ms protocol also led to a loss of SAI, but there was no correlation between individual changes in SAI and corticospinal excitability. These after-effects were still present 6 h after 5 Hz rPAS25ms. There was no consistent effect on ICI, ICF and LAI. The 5 Hz rENS and 5 Hz rTMS protocols failed to induce any change in corticospinal excitability when given alone. These findings show that 2 min of 5 Hz rPAS25ms produce a long-lasting and somatotopically specific increase in corticospinal excitability, presumably by sensorimotor disinhibition. PMID:16825301

  3. Intraoperative monitoring during decompression of the spinal cord and spinal nerves using transcranial motor-evoked potentials: The law of twenty percent.

    PubMed

    Tanaka, Satoshi; Hirao, Jun; Oka, Hidehiro; Akimoto, Jiro; Takanashi, Junko; Yamada, Junichi

    2015-09-01

    Motor-evoked potential (MEP) monitoring was performed during 196 consecutive spinal (79 cervical and 117 lumbar) surgeries for the decompression of compressive spinal and spinal nerve diseases. MEP monitoring in spinal surgery has been considered sensitive to predict postoperative neurological recovery. In this series, transcranial stimulation consisted of trains of five pulses at a constant voltage (200-600 V). For the normalization of MEP, we recorded compound muscle action potentials (CMAP) after peripheral nerve stimulation, usually on the median nerve at the wrist 2 seconds before or after each transcranial stimulation of the motor area, for all operations. The sensitivity and specificity of MEP monitoring was 100% and 97.4%, respectively, or 96.9% with or without CMAP compensation (if the threshold of postoperative motor palsy was defined as 20% relative amplitude rate [RAR]). The mean RAR after CMAP normalization, of the most affected muscle in the patient group with excellent postoperative results (recovery rate of a Japan Orthopedic Association score of more than 50%) was significantly higher than that in the other groups (p=0.0224). All patients with an amplitude increase rate (AIR) with CMAP normalization of more than 20% achieved neurological recovery postoperatively. Our results suggest that if the RAR is more than 20%, postoperative motor palsy can be avoided in spinal surgery. If the AIR with normalization by CMAP after peripheral nerve stimulation is more than 20%, neurological recovery can be expected in spinal surgery.

  4. Ocular Rosacea

    MedlinePlus

    ... Staff Ocular rosacea is inflammation that causes redness, burning and itching of the eyes. It often develops ... symptoms of ocular rosacea may include: Dry eyes Burning or stinging in the eyes Itchy eyes Grittiness ...

  5. Peribulbar anesthesia for cataract surgery: Effect of lidocaine warming and alkalinization on injection pain, motor and sensory nerve blockade

    PubMed Central

    Jaichandran, Venkatakrishnan; Vijaya, Lingam; George, Ronnie Jacob; InderMohan, Bhanulakshmi

    2010-01-01

    Aim: To compare self-reported pain and efficacy of warmed, alkalinized, and warmed alkalinized lidocaine with plain 2% lidocaine at room temperature for peribulbar anesthesia in cataract surgery. Materials and Methods: Through a prospective, single-blinded, randomized, controlled clinical trial 200 patients were divided into four groups. They received either lidocaine at operating room temperature 18°C, control group (Group C), lidocaine warmed to 37°C (Group W), lidocaine alkalinized to a pH of 7.09 ± 0.10 (Group B) or lidocaine at 37°C alkalinized to a pH of 6.94 ± 0.05 (Group WB). All solutions contained Inj. Hyaluronidase 50 IU/ml. Pain was assessed using a 10-cm visual analog score scale. Time of onset of sensory and motor blockade and time to onset of postoperative pain were recorded by a blinded observer. Results: Mean pain score was significantly lower in Group B and WB compared with Group C (P < 0.001). Onset of analgesia was delayed in Group C compared with Group B (P = 0.021) and WB (P < 0.001). Mean time taken for the onset of complete akinesia and supplementation required for the block was significantly lower in Group B. Time of onset of pain after operation was significantly earlier in Group W compared with Group C (P = 0.036). Conclusion: Alkalinized lidocaine with or without warming produced less pain than lidocaine injected at room temperature. Alkalinization enhances the effect of warming for sensory nerve blockade, but warming does not enhance alkalinization, in fact it reduces the efficacy of alkalinized solution for blocking the motor nerves in the eye. PMID:20195031

  6. Smile reconstruction in adults with free muscle transfer innervated by the masseter motor nerve: effectiveness and cerebral adaptation.

    PubMed

    Manktelow, Ralph T; Tomat, Laura R; Zuker, Ron M; Chang, Mary

    2006-09-15

    This study assesses the ability of the masseter motor nerve-innervated microneurovascular muscle transfer to produce an effective smile in adult patients with bilateral and unilateral facial paralysis. The operation consists of a one-stage microneurovascular transfer of a portion of the gracilis muscle that is innervated with the masseter motor nerve. The muscle is inserted into the cheek and attached to the mouth to produce a smile. The outcomes assessed were the amount of movement of the transferred muscle; the aesthetic quality of the smile; the control, use, and spontaneity of the smile; and the functional effects on eating, drinking, and speech. The study included 27 patients aged 16 to 61 years who received 45 muscle transfers. All 45 muscle transfers developed movement. The commissure movement averaged 13.0 +/- 4.7 mm at an angle of 47 +/- 15 degrees above the horizontal, and the mid upper lip movement averaged 8.3 +/- 3.0 mm at 42 +/- 17 degrees. Age did not affect the amount of movement. Patients older than 50 years had the same amount of movement as patients younger than 26 years (p = 0.605). Ninety-six percent of patients were satisfied with their smile. A spontaneous smile, the ability to smile without thinking about it, occurred routinely in 59 percent and occasionally in 29 percent of patients. Eighty-five percent of patients learned to smile without biting. Age did not affect the degree of spontaneity of smiling or the patient's ability to smile without biting.

  7. Relationship between interstitial cells of Cajal, fibroblast-like cells and inhibitory motor nerves in the internal anal sphincter.

    PubMed

    Cobine, Caroline A; Hennig, Grant W; Kurahashi, Masaaki; Sanders, Kenton M; Ward, Sean M; Keef, Kathleen D

    2011-04-01

    Interstitial cells of Cajal (ICC) have been shown to participate in nitrergic neurotransmission in various regions of the gastrointestinal (GI) tract. Recently, fibroblast-like cells, which are positive for platelet-derived growth factor receptor α (PDGFRα(+)), have been suggested to participate additionally in inhibitory neurotransmission in the GI tract. The distribution of ICC and PDGFRα(+) cell populations and their relationship to inhibitory nerves within the mouse internal anal sphincter (IAS) are unknown. Immunohistochemical techniques and confocal microscopy were therefore used to examine the density and arrangement of ICC, PDGFRα(+) cells and neuronal nitric-oxide-synthase-positive (nNOS(+)) nerve fibers in the IAS of wild-type (WT) and W/W ( v ) mice. Of the total tissue volume within the IAS circular muscle layer, 18% consisted in highly branched PDGFRα(+) cells (PDGFRα(+)-IM). Other populations of PDGFRα(+) cells were observed within the submucosa and along the serosal and myenteric surfaces. Spindle-shaped intramuscular ICC (ICC-IM) were present in the WT mouse IAS but were largely absent from the W/W ( v ) IAS. The ICC-IM volume (5% of tissue volume) in the WT mouse IAS was significantly smaller than that of PDGFRα(+)-IM. Stellate-shaped submucosal ICC (ICC-SM) were observed in the WT and W/W ( v ) IAS. Minimum surface distance analysis revealed that nNOS(+) nerve fibers were closely aligned with both ICC-IM and PDGFRα(+)-IM. An even closer association was seen between ICC-IM and PDGFRα(+)-IM. Thus, a close morphological arrangement exists between inhibitory motor neurons, ICC-IM and PDGFRα(+)-IM suggesting that some functional interaction occurs between them contributing to inhibitory neurotransmission in the IAS.

  8. Can motor nerve conduction velocity predict foot problems in diabetic subjects over a 6-year outcome period?

    PubMed

    Carrington, Anne L; Shaw, Jonathan E; Van Schie, Carine H M; Abbott, Caroline A; Vileikyte, Loretta; Boulton, Andrew J M

    2002-11-01

    This study examined motor nerve conduction velocity (MNCV) and other peripheral nerve and vascular tests as predictors for foot ulceration, amputation, and mortality in diabetes over a 6-year follow-up period. We recruited 169 diabetic subjects (without significant peripheral vascular disease with an ankle brachial pressure index [ABPI] >/=0.75) for the study and separated them into groups (to ensure diversity of nerve function). The control group consisted of 22 nondiabetic people. At baseline, all subjects underwent assessment of MNCV; vibration, pressure, and temperature perception thresholds; peripheral vascular function; and other diabetes assessments. Over the 6-year outcome period, 37.3% of the diabetic subjects developed at least one new ulcer, 11.2% had a lower-limb amputation (LLA) (minor or major), and 18.3% died. Using multivariate Cox's regression analysis (RR [95% CI] and removing previous ulcers as a confounding variable, MNCV was found to be the best predictor of new ulceration (0.90 [0.84-0.96], P = 0.001) and the best predictors of amputation were pressure perception threshold (PPT) (5.18 [1.96-13.68], P = 0.001) and medial arterial calcification (2.88 [1.13-7.35], P = 0.027). Creatinine (1.01 [1.00-1.01], P < 0.001), MNCV (0.84 [0.73-0.97], P = 0.016), and skin oxygen levels (14.32 [3.04-67.52], P = 0.001) were the best predictors of mortality. This study shows that MNCV, which is often assessed in clinical trials of neuropathy, can predict foot ulceration and death in diabetes. In addition, tests of PPT and medial arterial calcification can be used in the clinic to predict LLA in diabetic subjects.

  9. Interaction of /sup 125/I-labeled botulinum neurotoxins with nerve terminals. I. Ultrastructural autoradiographic localization and quantitation of distinct membrane acceptors for types A and B on motor nerves

    SciTech Connect

    Black, J.D.; Dolly, J.O.

    1986-01-01

    The labeling patterns produced by radioiodinated botulinum neurotoxin (/sup 125/I-BoNT) types A and B at the vertebrate neuromuscular junction were investigated using electron microscopic autoradiography. The data obtained allow the following conclusions to be made. (a) /sup 125/I-BoNT type A, applied in vivo or in vitro to mouse diaphragm or frog cutaneous pectoris muscle, interacts saturably with the motor nerve terminal only; silver grains occur on the plasma membrane, within the synaptic bouton, and in the axoplasm of the nerve trunk, suggesting internalization and retrograde intra-axonal transport of toxin or fragments thereof. (b) /sup 125/I-BoNT type B, applied in vitro to the murine neuromuscular junction, interacts likewise with the motor nerve terminal except that a lower proportion of internalized radioactivity is seen. This result is reconcilable with the similar, but not identical, pharmacological action of these toxin types. (c) The saturability of labeling in each case suggested the involvement of acceptors; on preventing the internalization step with metabolic inhibitors, their precise location became apparent. They were found on all unmyelinated areas of the nerve terminal membrane, including the preterminal axon and the synaptic bouton. (d) It is not proposed that these membrane acceptors target BoNT to the nerve terminal and mediate its delivery to an intracellular site, thus contributing to the toxin's selective inhibitory action on neurotransmitter release.

  10. 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.

  11. A differential synaptic input to the motor nuclei of triceps surae from the caudal and lateral cutaneous sural nerves.

    PubMed

    LaBella, L A; Kehler, J P; McCrea, D A

    1989-02-01

    1. Postsynaptic potentials (PSPs) were recorded in 115 triceps surae motoneurons of 10 chloralose-anesthetized adult cats (spinal cord intact), upon electrical stimulation of the caudal and lateral cutaneous sural nerve branches (CCS and LCS, respectively). 2. With twice threshold (2T) stimulation of CCS, excitatory PSPs (EPSPs) were the predominant effect in 95% of all medial gastrocnemius (MG) motoneurons tested (min. central latency 1.5 ms; mean 2.4 ms). In only a few MG cells was the EPSP followed by an inhibitory postsynaptic potential (IPSP) and in only one cell was an IPSP the sole effect. Increasing the stimulus intensity to 5T tended to enhance both the later EPSP and IPSP components, with less change in the amplitude or latency of the earliest EPSPs. 3. In lateral gastrocnemius (LG) and soleus (SOL) motoneurons, 2T CCS stimulation led to either inhibition or no potential change in the majority of cells tested: EPSPs were the predominant effect in only 15 and 30% of LG and SOL cells, respectively (min. central latency 2.5 ms; mean 3.0 ms) and rarely occurred without subsequent inhibition. Again, increasing the stimulus intensity to 5T had more of an effect on later rather than earlier PSP components. 4. A predominance of depolarization in MG motoneurons but not in SOL motoneurons is in agreement with previous findings that CCS excitation is more powerful in "fast type" triceps surae motoneurons. However, the strong predominance of hyperpolarizing effects of CCS stimulation in the present LG population is evidence that such an organization does not transcend triceps surae motor nuclei as a whole. 5. Postsynaptic effects of LCS stimulation at 2T were frequently weak or absent but increasing the stimulus intensity to 5T produced predominant inhibition in 71% of all triceps surae motoneurons studied (n = 107). Of the few cells which did receive excitation from this nerve, most were MG, a few were SOL, and none were LG. These EPSPs occurred more frequently at 5

  12. Successive motor nerve blocks to identify the muscles causing a spasticity pattern: example of the arm flexion pattern.

    PubMed

    Genet, F; Schnitzler, A; Droz-Bartholet, F; Salga, M; Tatu, L; Debaud, C; Denormandie, P; Parratte, B

    2017-01-01

    Botulinum Toxin A has been the main treatment for spasticity since the beginning of the 1990s. Surprisingly, there is still no consensus regarding injection parameters or, importantly, how to determine which muscles to target to improve specific functions. The aim of this study was to develop a systematic approach to determine this, using the example of the arm flexion pattern. We first determined anatomical landmarks for selective motor block of the brachialis nerve, using 20 forearms from 10 fresh cadavers in Ecole Européenne de Chirurgie and a university-based dissection centre, Paris, France. We then carried out selective blocks of the motor nerves to the brachialis, brachioradialis and biceps brachii in patients with stroke with an arm flexion pattern, in a University Rehabilitation Hospital, Garches, France. We measured: the resting angle of the elbow angle in standing (manual goniometer), active and passive range of extension, and spasticity using the Held and Tardieu and the Modified Ashworth scales. Range of passive elbow extension was also measured with the shoulder in 90° of flexion. The resting angle of the elbow in standing decreased by 35.0° (from 87.6 ± 23.7 to 52.6 ± 24.2°) with inhibition of brachialis, by a further 3.9° (from 52.6 ± 24.2 to 48.7 ± 23.7°) with inhibition of brachioradialis and a further 14.5° (from 48.7 ± 23.7to 34.2 ± 20.7°) with inhibition of biceps brachii. These results were consistent with the clinical evaluation of passive elbow range of motion with the shoulder at 90°. Sequential blocking of the nerves to the three main elbow flexors revealed that the muscle that limited elbow extension the most, was brachialis. This muscle should be the main target to improve the arm flexion pattern. These results show that it is important not simply to inject the most superficial or powerful muscles to treat a spastic deformity. A comprehensive assessment is required. The strategy proposed in this paper should

  13. Collateral projections of the dorsal motor nucleus of the vagus nerve to the stomach and the intestines in the rat.

    PubMed

    Hayakawa, Tetsu; Kuwahara-Otani, Sachi; Maeda, Seishi; Tanaka, Koichi; Seki, Makoto

    2013-01-01

    The vagal motor neurons project to the gastrointestinal tract by way of the gastric, celiac and hepatic branches of the vagus trunk. We have examined whether single neurons in the dorsal motor nucleus of the vagus nerve (DMV) have collateral projections to the stomach, the duodenum and the intestines using a double-labeling tracing method. Following application of Fluorogold to the cut end of the accessory celiac branch and injection of cholera toxin subunit b (CTb) into the body of stomach, many Fluorogold- and CTb-labeled neurons were found throughout the DMV. Most CTb-labeled neurons (about 90%) were also labeled with Fluorogold. When Fluorogold was applied to the cut end of the accessory celiac or the gastric branch and CTb was injected into the duodenum, many Fluorogold-labeled neurons and CTb-labeled neurons were found in the DMV. About 20% of CTb-labeled neurons were also labeled with Fluorogold. These results indicate that many neurons in the DMV send collateral projections to both the stomach and the intestines innervated by way of the celiac branch. However, many neurons in the DMV projecting to the duodenum do not project to the stomach or the intestines caudal to the duodenum.

  14. Eye movement recordings as an effectiveness indicator of gene therapy in RPE65-deficient canines: implications for the ocular motor system.

    PubMed

    Jacobs, Jonathan B; Dell'Osso, Louis F; Hertle, Richard W; Acland, Gregory M; Bennett, Jean

    2006-07-01

    To perform ocular motility recordings of infantile nystagmus (IN) in RPE65-deficient canines and determine whether they can be used as a motor indicator of restored retinal function to investigate the effects of gene therapy. Treated and untreated canines were comfortably suspended in a custom-built sling and encouraged to fixate on distant targets at gaze angles varying between +/-15 degrees horizontally and +/-10 degrees vertically. Ocular motility recordings were made, using two distinct methods-infrared reflection and high-speed video. The resultant recordings from three untreated, four treated, and three pre- and post-treatment dogs were analyzed for using the eXpanded Nystagmus Acuity Function (NAFX), which yields an objective assessment of best potential visual acuity, based on the duration and repeatable accuracy of foveation and centralisation. During fixation, the untreated dogs exhibited large-amplitude, classic IN waveforms, including pendular and jerk in both the horizontal and vertical planes, which prevented them from keeping the targets within the area centralis (the region of highest receptor density, spanning +/-3 degrees horizontally by +/-1.5 degrees vertically, analogous to the fovea). Some untreated dogs also had small-amplitude (0.5-1 degrees), high-frequency (6-9 Hz) oscillations. Under the same conditions, successfully treated canines no longer exhibited clinically detectable IN. Their IN was converted to waveforms with very low amplitudes that yielded higher NAFX values and allowed target images to remain well within the area centralis. Of note, uniocular treatment appeared to damp the IN in both eyes. Behaviorally, the treated dogs were able to successfully navigate through obstacles more easily without inadvertent contact, a task beyond the untreated dogs' ability. Gene therapy that successfully restored retinal function also reduced the accompanying IN to such a great extent that it was not clinically detectable approximately 90% of the

  15. Characterization of Thoracic Motor and Sensory Neurons and Spinal Nerve Roots in Canine Degenerative Myelopathy, a Potential Disease Model of Amyotrophic Lateral Sclerosis

    PubMed Central

    Morgan, Brandie R.; Coates, Joan R.; Johnson, Gayle C.; Shelton, G. Diane; Katz, Martin L.

    2014-01-01

    Canine Degenerative Myelopathy (DM) is a progressive adult-onset multisystem degenerative disease with many features in common with amyotrophic lateral sclerosis (ALS). As with some forms of ALS, DM is associated with mutations in superoxide dismutase 1 (SOD1). Clinical signs include general proprioceptive ataxia and spastic upper motor neuron paresis in pelvic limbs, which progress to flaccid tetraplegia and dysphagia. The purpose of this study was to characterize DM as a potential disease model for ALS. We previously reported that intercostal muscle atrophy develops in dogs with advanced stage DM. To determine if other components of the thoracic motor unit (MU) also demonstrated morphological changes consistent with dysfunction, histopathologic and morphometric analyses were conducted on thoracic spinal motor neurons (MN) and dorsal root ganglia (DRG), and in motor and sensory nerve root axons from DM-affected Boxers and Pembroke Welsh Corgis (PWCs). No alterations in MNs, or motor root axons were observed in either breed. However, advanced stage PWCs exhibited significant losses of sensory root axons, and numerous DRG sensory neurons displayed evidence of degeneration. These results indicate that intercostal muscle atrophy in DM is not preceded by physical loss of the motor neurons innervating these muscles, or of their axons. Axonal loss in thoracic sensory roots and sensory nerve death suggest sensory involvement may play an important role in DM disease progression. Further analysis of the mechanisms responsible for these morphological findings would aid in the development of therapeutic intervention for DM and some forms of ALS. PMID:24375814

  16. Motor responses of muscles supplied by cranial nerves to subthalamic nucleus deep brain stimuli.

    PubMed

    Costa, João; Valls-Solé, Josep; Valldeoriola, Francesc; Rumià, Jordi; Tolosa, Eduardo

    2007-01-01

    The distribution of human corticobulbar motor excitatory and inhibitory output is not fully understood. In particular, it is unclear whether the pattern of innervation is the same for upper and lower facial muscles, and what is the motor cortical area giving rise to such innervation. We used electrodes implanted in the subthalamic nucleus (STN) in patients with Parkinson's disease to activate motor tracts at a subcortical level. We examined the excitatory and inhibitory effects of unilateral single STN deep brain stimulation (sSTN-DBS) in 14 patients by taking recordings from facial, cervical and upper limb muscles on both sides. We measured the latency and amplitude of the motor-evoked potentials (MEPs), and the latency and duration of the silent periods, and compared ipsilateral with contralateral responses and responses obtained in different muscles. Unilateral sSTN-DBS induced strictly contralateral MEPs in the trapezius, deltoid, biceps and thenar muscles. The same stimulus always induced bilateral MEPs in the orbicularis oculi, orbicularis oris, masseter and sternocleidomastoid at a mean latency in the range 6.0-9.1 ms. MEP latencies in the orbicularis oculi and orbicularis oris were significantly longer than in the masseter and sternocleidomastoid (P < 0.01). A short latency small action potential was recorded in the ipsilateral orbicularis oculi that was likely generated by activation of extraocular muscles. During sustained voluntary muscle contraction, a silent period was recorded at similar onset latency on both sides. This period was significantly shorter in orbicularis oculi than in masseter, and in the ipsilateral side for both muscles (P < 0.01). sSTN-DBS is able to activate the descending projecting fibres in the corticobulbar tract eliciting bilateral MEPs and silent periods in facial and cranial muscles. This suggests that fibres to both ipsi- and contralateral motor nuclei descend together at the level of the STN. These findings are relevant in

  17. Presynaptic mitochondria in functionally different motor neurons exhibit similar affinities for Ca2+ but exert little influence as Ca2+ buffers at nerve firing rates in situ

    PubMed Central

    Chouhan, Amit K.; Zhang, Jinhui; Zinsmaier, Konrad E.; Macleod, Gregory T.

    2010-01-01

    Mitochondria accumulate within nerve terminals and support synaptic function, most notably through ATP production. They can also sequester Ca2+ during nerve stimulation, but it is unknown whether this limits presynaptic Ca2+ levels at physiological nerve firing rates. Similarly, it is unclear whether mitochondrial Ca2+ sequestration differs between functionally different nerve terminals. We addressed these questions using a combination of synthetic and genetically-encoded Ca2+ indicators (GECIs) to examine cytosolic and mitochondrial Ca2+ levels in presynaptic terminals of tonic (MN13-Ib) and phasic (MNSNb/d-Is) motor neurons in Drosophila, which, as we determined, fire during fictive locomotion at ∼42 Hz and ∼8 Hz, respectively. Mitochondrial Ca2+ sequestration starts in both terminals at ∼250 nM, exhibits a similar Ca2+-uptake affinity (∼410 nM), and does not require Ca2+ release from the endoplasmic reticulum. Nonetheless, mitochondrial Ca2+ uptake in type-Is terminals is more responsive to low frequency nerve stimulation and this is due to higher cytosolic Ca2+ levels. Since type-Ib terminals have a higher mitochondrial density than Is terminals, it seemed possible that greater mitochondrial Ca2+ sequestration may be responsible for the lower cytosolic Ca2+ levels in Ib terminals. However, genetic and pharmacological manipulations of mitochondrial Ca2+ uptake did not significantly alter nerve-stimulated elevations in cytosolic Ca2+ levels in either terminal type within physiologically relevant rates of stimulation. Our findings indicate that presynaptic mitochondria have a similar affinity for Ca2+ in functionally different nerve terminals, but do not limit cytosolic Ca2+ levels within the range of motor neuron firing rates in situ. PMID:20130196

  18. Presynaptic mitochondria in functionally different motor neurons exhibit similar affinities for Ca2+ but exert little influence as Ca2+ buffers at nerve firing rates in situ.

    PubMed

    Chouhan, Amit K; Zhang, Jinhui; Zinsmaier, Konrad E; Macleod, Gregory T

    2010-02-03

    Mitochondria accumulate within nerve terminals and support synaptic function, most notably through ATP production. They can also sequester Ca(2+) during nerve stimulation, but it is unknown whether this limits presynaptic Ca(2+) levels at physiological nerve firing rates. Similarly, it is unclear whether mitochondrial Ca(2+) sequestration differs between functionally different nerve terminals. We addressed these questions using a combination of synthetic and genetically encoded Ca(2+) indicators to examine cytosolic and mitochondrial Ca(2+) levels in presynaptic terminals of tonic (MN13-Ib) and phasic (MNSNb/d-Is) motor neurons in Drosophila, which, as we determined, fire during fictive locomotion at approximately 42 Hz and approximately 8 Hz, respectively. Mitochondrial Ca(2+) sequestration starts in both terminals at approximately 250 nM, exhibits a similar Ca(2+)-uptake affinity (approximately 410 nM), and does not require Ca(2+) release from the endoplasmic reticulum. Nonetheless, mitochondrial Ca(2+) uptake in type Is terminals is more responsive to low-frequency nerve stimulation and this is due to higher cytosolic Ca(2+) levels. Since type Ib terminals have a higher mitochondrial density than Is terminals, it seemed possible that greater mitochondrial Ca(2+) sequestration may be responsible for the lower cytosolic Ca(2+) levels in Ib terminals. However, genetic and pharmacological manipulations of mitochondrial Ca(2+) uptake did not significantly alter nerve-stimulated elevations in cytosolic Ca(2+) levels in either terminal type within physiologically relevant rates of stimulation. Our findings indicate that presynaptic mitochondria have a similar affinity for Ca(2+) in functionally different nerve terminals, but do not limit cytosolic Ca(2+) levels within the range of motor neuron firing rates in situ.

  19. Constituent ratio of motor fibers from the C5-C7 spinal nerves in the radial nerve is greater in pup rats than in adult rats.

    PubMed

    Nie, Mingbo; Chen, Liang; Gu, Yudong

    2012-06-01

    Clinically, injuries of C5-C7 of the brachial plexus cause falling of the wrist and fingers in infants but not in adults unless 4 consecutive spinal nerves are injured. The purpose of this study was to compare the constituent difference of spinal nerves in the radial nerve between pup and adult rats.A group of 16 pup rats and a group of 16 adult rats were each divided into 2 groups of 8 (P1 and A1 groups, C5-C6 were divided; P2 and A2 groups, C5-C7 were divided]). A nerve conduction study and histological examination were performed to evaluate radial nerve innervation to the extensor digitorum communis muscle after dividing the spinal nerves. Retrograde tracing with 5% cholera toxin B for anterior horn motoneurons of the spinal cord innervating the radial nerve was performed in 8 pup rats and 8 adult rats. Results showed that the division of C5-C7 caused more significant damage to radial nerve innervation to the extensor digitorum communis in pups than in adults, although the division of C5-C6 did not. In pups, the percentages (median with interquartile) of anterior horn motoneurons of the spinal cord innervating the radial nerve were 36.4 (28.3-38.5) in C5-C6, 28.1 (24.5-32.5) in C7, and 37.5 (36.5-39.3) in C8-T1. In adults, they were 24.2 (23.6-27.8) in C5-C6, 21.8 (19.5-26.3) in C7, and 50.7 (48.7-55.5) C8-T1.This study implies that C7 innervation in the radial nerve in humans may be more critical to the function of this nerve in infants than in adults.

  20. [Ocular allergies].

    PubMed

    Messmer, E M

    2005-05-01

    Recent developments indicate that ocular allergy is more than an IgE-mediated allergic conjunctivitis. Ocular allergy is a disease affecting the entire ocular surface including conjunctiva, lids, cornea, lacrimal gland and tear film. Besides an IgE-mediated reaction, a complex chronic inflammation is involved in the pathogenesis of many ocular allergies. According to their pathogenesis and clinical picture, ocular allergies are classified into mild forms, such as seasonal and perennial allergic conjunctivitis as well as giant papillary conjunctivitis, and chronic, potentially blinding forms such as atopic keratoconjunctivitis and vernal keratoconjunctivitis. New therapeutics act on the entire inflammatory process or try to modulate the allergic reaction early and specifically. The association with non-ocular allergic symptoms requires an interdisciplinary approach.

  1. Role of the Internal Superior Laryngeal Nerve in the Motor Responses of Vocal Cords and the Related Voice Acoustic Changes

    PubMed Central

    Seifpanahi, Sadegh; Izadi, Farzad; Jamshidi, Ali-Ashraf; Torabinezhad, Farhad; Sarrafzadeh, Javad; Mohammadi, Siavash

    2016-01-01

    Background: Repeated efforts by researchers to impose voice changes by laryngeal surface electrical stimulation (SES) have come to no avail. This present pre-experimental study employed a novel method for SES application so as to evoke the motor potential of the internal superior laryngeal nerve (ISLN) and create voice changes. Methods: Thirty-two normal individuals (22 females and 10 males) participated in this study. The subjects were selected from the students of Iran University of Medical Sciences in 2014. Two monopolar active electrodes were placed on the thyrohyoid space at the location of the ISLN entrance to the larynx and 1 dispersive electrode was positioned on the back of the neck. A current with special programmed parameters was applied to stimulate the ISLN via the active electrodes and simultaneously the resultant acoustic changes were evaluated. All the means of the acoustic parameters during SES and rest periods were compared using the paired t-test. Results: The findings indicated significant changes (P=0.00) in most of the acoustic parameters during SES presentation compared to them at rest. The mean of fundamental frequency standard deviation (SD F0) at rest was 1.54 (SD=0.55) versus 4.15 (SD=3.00) for the SES period. The other investigated parameters comprised fundamental frequency (F0), minimum F0, jitter, shimmer, harmonic-to-noise ratio (HNR), mean intensity, and minimum intensity. Conclusion: These findings demonstrated significant changes in most of the important acoustic features, suggesting that the stimulation of the ISLN via SES could induce motor changes in the vocal folds. The clinical applicability of the method utilized in the current study in patients with vocal fold paralysis requires further research. PMID:27582586

  2. Heparin blocks functional innervation of cultured human muscle by rat motor nerve.

    PubMed

    Marš, Tomaž; King, Michael P; Miranda, Armand F; Grubič, Zoran

    2000-01-01

    In vitro innervated human muscle is the only experimental model to study synaptogenesis of the neuromuscular junction in humans. Cultured human muscle never contracts spontaneously but will if innervated and therefore is a suitable model to study the effects of specific neural factors on the formation of functional neuromuscular contacts. Here, we tested the hypothesis that nerve derived factor agrin is essential for the formation of functional synapses between human myotubes and motoneurons growing from the explant of embryonic rat spinal cord. Agrin actions were blocked by heparin and the formation of functional neuromuscular contacts was quantitated. At a heparin concentration of 25 μg/ml, the number of functional contacts was significantly reduced. At higher concentrations, formation of such contacts was blocked completely. Except at the highest heparin concentrations (150 μg/ml) neuronal outgrowth was normal indicating that blockade of neuromuscular junction formation was not due to neuronal dysfunction. Our results are in accord with the concept that binding of neural agrin to the synaptic basal lamina is essential for the formation of functional neuromuscular junctions in the human muscle.

  3. Heparin blocks functional innervation of cultured human muscle by rat motor nerve.

    PubMed

    Mars, T; King, M P; Miranda, A F; Grubic, Z

    2000-01-01

    In vitro innervated human muscle is the only experimental model to study synaptogenesis of the neuromuscular junction in humans. Cultured human muscle never contracts spontaneously but will if innervated and therefore is a suitable model to study the effects of specific neural factors on the formation of functional neuromuscular contacts. Here, we tested the hypothesis that nerve derived factor agrin is essential for the formation of functional synapses between human myotubes and motoneurons growing from the explant of embryonic rat spinal cord. Agrin actions were blocked by heparin and the formation of functional neuromuscular contacts was quantitated. At a heparin concentration of 25 microg/ml, the number of functional contacts was significantly reduced. At higher concentrations, formation of such contacts was blocked completely. Except at the highest heparin concentrations (150 microg/ml) neuronal outgrowth was normal indicating that blockade of neuromuscular junction formation was not due to neuronal dysfunction. Our results are in accord with the concept that binding of neural agrin to the synaptic basal lamina is essential for the formation of functional neuromuscular junctions in the human muscle.

  4. Sequence and phylogenetic analysis of squid myosin-V: a vesicle motor in nerve cells.

    PubMed

    Molyneaux, B J; Mulcahey, M K; Stafford, P; Langford, G M

    2000-06-01

    We have shown that vesicles in the axoplasm of the squid giant axon move on actin filaments and that movement is inhibited by myosin V-specific antibodies [Tabb et al., 1998]. In the study reported in this article, experiments were performed to clone and sequence the cDNA for squid brain myosin V. Five proteolytic fragments of purified squid brain myosin V were analyzed by direct protein sequencing [Tabb et al., 1998]. Based on this sequence information, degenerate primers were constructed and used to isolate cDNA clones by PCR. Five clones, representing overlapping segments of the gene, were sequenced. The sequence data and the previous biochemical characterization of the molecule support the classification of this vesicle-associated myosin as a member of the class V myosins. Motif analysis of the head, neck, and tail domains revealed that squid MyoV has consensus sequences for all the motifs found in vertebrate members of the myosin V family of motor proteins. A phylogenetic tree was constructed from a sequence alignment by the neighbor-joining method, using Megalign (DNAStar, Madison, WI); the resulting phylogenetic tree showed that squid MyoV is more closely related to vertebrate MyoV (mouse dilute, chicken dilute, rat myr6, and human myo5a) than Drosophila and yeast (myo2, and myo4) myosins V. These new data on the phylogenetic relationships of squid myosin V to vertebrate myosin V strengthens the argument that myosin V functions as a vesicle motor in vertebrate neurons. Copyright 2000 Wiley-Liss, Inc.

  5. Increase in flexor but not extensor corticospinal motor outputs following ischemic nerve block.

    PubMed

    Vallence, Ann-Maree; Hammond, Geoffrey R; Reilly, Karen T

    2012-06-01

    Human motor cortex is capable of rapid and long-lasting reorganization, evident globally, as shifts in body part representations, and at the level of individual muscles as changes in corticospinal excitability. Representational shifts provide an overview of how various body parts reorganize relative to each other but do not tell us whether all muscles in a given body part reorganize in the same manner and to the same extent. Transcranial magnetic stimulation (TMS) provides information about individual muscles and can therefore inform us about the uniformity of plastic changes within a body part. We used TMS to investigate changes in corticospinal excitability of forearm flexors and extensors after inflation of a tourniquet around the wrist. Motor evoked potential (MEP) amplitudes and input/output (I/O) curves were obtained from wrist flexors and extensors simultaneously before and during block. TMS was delivered to the optimal site for eliciting MEPs in flexors in experiment 1, extensors in experiment 2, and both flexors and extensors in experiment 3. In all experiments flexor MEP amplitude increased during block while extensor MEP amplitude showed no systematic change, and the slope of flexor but not extensor I/O curves increased. Flexor H-reflex amplitude normalized to maximal M wave showed negligible changes during block, suggesting that the increase in corticospinal excitability in the flexors cannot be completely explained by increased excitability at the spinal cord level. These findings show that forearm flexors and extensors differ in their potential for plastic changes, highlight the importance of investigating how experimentally induced plasticity affects anatomically close, but functionally distinct, muscle groups, and suggest that rehabilitation interventions aiming to alter cortical organization should consider the differential sensitivity of various muscle groups to plasticity processes.

  6. Linear methods for reducing EMG contamination in peripheral nerve motor decodes.

    PubMed

    Kagan, Zachary B; Wendelken, Suzanne; Page, David M; Davis, Tyler; Hutchinson, Douglas T; Clark, Gregory A; Warren, David J

    2016-08-01

    Signals recorded from the peripheral nervous system (PNS) with high channel count penetrating microelectrode arrays, such as the Utah Slanted Electrode Array (USEA), often have electromyographic (EMG) signals contaminating the neural signal. This common-mode signal source may prevent single neural units from successfully being detected, thus hindering motor decode algorithms. Reducing this EMG contamination may lead to more accurate motor decode performance. A virtual reference (VR), created by a weighted linear combination of signals from a subset of all available channels, can be used to reduce this EMG contamination. Four methods of determining individual channel weights and six different methods of selecting subsets of channels were investigated (24 different VR types in total). The methods of determining individual channel weights were equal weighting, regression-based weighting, and two different proximity-based weightings. The subsets of channels were selected by a radius-based criteria, such that a channel was included if it was within a particular radius of inclusion from the target channel. These six radii of inclusion were 1.5, 2.9, 3.2, 5, 8.4, and 12.8 electrode-distances; the 12.8 electrode radius includes all USEA electrodes. We found that application of a VR improves the detectability of neural events via increasing the SNR, but we found no statistically meaningful difference amongst the VR types we examined. The computational complexity of implementation varies with respect to the method of determining channel weights and the number of channels in a subset, but does not correlate with VR performance. Hence, we examined the computational costs of calculating and applying the VR and based on these criteria, we recommend an equal weighting method of assigning weights with a 3.2 electrode-distance radius of inclusion. Further, we found empirically that application of the recommended VR will require less than 1 ms for 33.3 ms of data from one USEA.

  7. Targeted delivery into motor nerve terminals of inhibitors for SNARE-cleaving proteases via liposomes coupled to an atoxic botulinum neurotoxin.

    PubMed

    Edupuganti, Om P; Ovsepian, Saak V; Wang, Jiafu; Zurawski, Tomas H; Schmidt, James J; Smith, Leonard; Lawrence, Gary W; Dolly, J Oliver

    2012-07-01

    A targeted drug carrier (TDC) is described for transferring functional proteins or peptides into motor nerve terminals, a pivotal locus for therapeutics to treat neuromuscular disorders. It exploits the pronounced selectivity of botulinum neurotoxin type B (BoNT/B) for interacting with acceptors on these cholinergic nerve endings and becoming internalized. The gene encoding an innocuous BoNT/B protease-inactive mutant (BoTIM) was fused to that for core streptavidin, expressed in Escherichia coli and the purified protein was conjugated to surface-biotinylated liposomes. Such decorated liposomes, loaded with fluorescein as traceable cargo, acquired pronounced specificity for motor nerve terminals in isolated mouse hemidiaphragms and facilitated the intraneuronal transfer of the fluor, as revealed by confocal microscopy. Delivery of the protease light chain of botulinum neurotoxin type A (BoNT/A) via this TDC accelerated the onset of neuromuscular paralysis, indicative of improved translocation of this enzyme into the presynaptic cytosol with subsequent proteolytic inactivation of synaptosomal-associated protein of molecular mass 25 kDa (SNAP-25), an exocytotic soluble N-ethyl-maleimide-sensitive factor attachment protein receptor (SNARE) essential for neurotransmitter release. BoTIM-coupled liposomes, loaded with peptide inhibitors of proteases, yielded considerable attenuation of the neuroparalytic effects of BoNT/A or BoNT/F as a result of their cytosolic transfer, the first in situ demonstration of the ability of designer antiproteases to suppress the symptoms of botulism ex vivo. Delivery of the BoNT/A inhibitor by liposomes targeted with the full-length BoTIM proved more effective than that mediated by its C-terminal neuroacceptor-binding domain. This demonstrated versatility of TDC for nonviral cargo transfer into cholinergic nerve endings has unveiled its potential for direct delivery of functional targets into motor nerve endings.

  8. Central command: control of cardiac sympathetic and vagal efferent nerve activity and the arterial baroreflex during spontaneous motor behaviour in animals.

    PubMed

    Matsukawa, Kanji

    2012-01-01

    Feedforward control by higher brain centres (termed central command) plays a role in the autonomic regulation of the cardiovascular system during exercise. Over the past 20 years, workers in our laboratory have used the precollicular-premammillary decerebrate animal model to identify the neural circuitry involved in the CNS control of cardiac autonomic outflow and arterial baroreflex function. Contrary to the traditional idea that vagal withdrawal at the onset of exercise causes the increase in heart rate, central command did not decrease cardiac vagal efferent nerve activity but did allow cardiac sympathetic efferent nerve activity to produce cardiac acceleration. In addition, central command-evoked inhibition of the aortic baroreceptor-heart rate reflex blunted the baroreflex-mediated bradycardia elicited by aortic nerve stimulation, further increasing the heart rate at the onset of exercise. Spontaneous motor activity and associated cardiovascular responses disappeared in animals decerebrated at the midcollicular level. These findings indicate that the brain region including the caudal diencephalon and extending to the rostral mesencephalon may play a role in generating central command. Bicuculline microinjected into the midbrain ventral tegmental area of decerebrate rats produced a long-lasting repetitive activation of renal sympathetic nerve activity that was synchronized with the motor nerve discharge. When lidocaine was microinjected into the ventral tegmental area, the spontaneous motor activity and associated cardiovascular responses ceased. From these findings, we conclude that cerebral cortical outputs trigger activation of neural circuits within the caudal brain, including the ventral tegmental area, which causes central command to augment cardiac sympathetic outflow at the onset of exercise in decerebrate animal models.

  9. Stimulation-induced changes in [Ca2+] in lizard motor nerve terminals.

    PubMed Central

    David, G; Barrett, J N; Barrett, E F

    1997-01-01

    1. Motor axons were injected ionophoretically with one of five Ca(2+)-sensitive dyes (fluo-3, Calcium Green-2, Calcium Green-5N, fluo-3FF and Oregon Green BAPTA-5N). Changes in fluorescence (delta F/Frest) within motor terminal boutons following a single action potential and brief stimulus trains were monitored with high temporal resolution using a confocal microscope. 2. Stimulation-induced increases in delta F/Frest were confined primarily to boutons, with roughly uniform increases in all the boutons of a terminal. The increase in delta F/Frest began prior to, and decayed more slowly than, the endplate potential (EPP) recorded in the underlying muscle fibre. delta F/Frest was graded with bath [Ca2+]. Both delta F/Frest and the EPP were reduced, but not eliminated, by omega-conotoxin GVIA (5-10 microM). 3. For dyes with lower affinity for Ca2+ (e.g. Oregon Green BAPTA-5N, Kd approximately 60 microM) stimulation-induced increases in delta F/Frest were measured in the presence of the K+ channel blocker 3,4-diaminopyridine (3,4-DAP, 100 microM). During brief stimulus trains (4 at 50 Hz) in 3,4-DAP, the EPP exhibited profound depression, but the fluorescence increase associated with each stimulus showed little decrement, suggesting that depression was not mediated by a reduction in Ca2+ entry. 4. For dyes with a higher affinity for Ca2+ (e.g. fluo-3, Kd approximately 0.5-1 microM) stimulation-induced increases in delta F/Frest could also be measured in normal physiological saline. Increases in delta F/Frest were much greater with 3,4-DAP present, but the amplitude decreased with successive stimuli due to partial dye saturation. 5. Calculations suggested that following a single action potential the average [Ca2+] within a bouton increased by up to 150 nM in normal saline and 940 nM in 3,4-DAP. With low affinity dyes the delta F/Frest measured near the membrane had a higher peak amplitude and a faster early decay than that measured in the centre of the bouton

  10. Adverse ocular reactions to drugs.

    PubMed Central

    Spiteri, M. A.; James, D. G.

    1983-01-01

    Drugs acting on various parts of the body may also affect the eye insidiously. Increased awareness of such drug toxicity by the prescribing doctor should encourage him to consider effects on the cornea, lens, retina, optic nerve and elsewhere when checking the patient's progress. The following review concerns adverse ocular effects of systemic drug administration. PMID:6356101

  11. Ageing-induced changes in the redox status of peripheral motor nerves imply an effect on redox signalling rather than oxidative damage.

    PubMed

    McDonagh, Brian; Scullion, Siobhan M; Vasilaki, Aphrodite; Pollock, Natalie; McArdle, Anne; Jackson, Malcolm J

    2016-05-01

    Ageing is associated with loss of skeletal muscle fibres, atrophy of the remaining fibres and weakness. These changes in muscle are accompanied by disruption of motor neurons and neuromuscular junctions although the direct relationship between the nerve and muscle degeneration is not understood. Oxidative changes have been implicated in the mechanisms leading to age-related loss of muscle mass and in degeneration of the central nervous system, but little is known about age-related changes in oxidation in specific peripheral nerves that supply muscles that are affected by ageing. We have therefore examined the sciatic nerve of old mice at an age when loss of tibialis anterior muscle mass and function is apparent. Sciatic nerve from old mice did not show a gross increase in oxidative damage, but electron paramagnetic resonance (EPR) studies indicated an increase in the activity of superoxide and/or peroxynitrite in the nerves of old mice at rest that was further exacerbated by electrical stimulation of the nerve to activate muscle contractions. Proteomic analyses indicated that specific redox-sensitive proteins are increased in content in the nerves of old mice that may reflect an adaptation to regulate the increased superoxide/peroxynitrite and maintain redox homoeostasis. Analysis of redox active cysteines showed some increase in reversible oxidation in specific proteins in nerves of old mice, but this was not universally seen across all redox-active cysteines. Detailed analysis of the redox-active cysteine in one protein in the nerve of old mice that is key to redox signalling (Peroxiredoxin 6, Cys 47) showed a minor increase in reversible oxidation that would be compatible with a change in its redox signalling function. In conclusion, the data presented indicate that sciatic nerve from old mice does not show a gross increase in oxidative damage similar to that seen in the TA and other muscles that it innervates. Our results indicate an adaptation to increased

  12. Ageing-induced changes in the redox status of peripheral motor nerves imply an effect on redox signalling rather than oxidative damage

    PubMed Central

    McDonagh, Brian; Scullion, Siobhan M.; Vasilaki, Aphrodite; Pollock, Natalie; McArdle, Anne; Jackson, Malcolm J.

    2016-01-01

    Ageing is associated with loss of skeletal muscle fibres, atrophy of the remaining fibres and weakness. These changes in muscle are accompanied by disruption of motor neurons and neuromuscular junctions although the direct relationship between the nerve and muscle degeneration is not understood. Oxidative changes have been implicated in the mechanisms leading to age-related loss of muscle mass and in degeneration of the central nervous system, but little is known about age-related changes in oxidation in specific peripheral nerves that supply muscles that are affected by ageing. We have therefore examined the sciatic nerve of old mice at an age when loss of tibialis anterior muscle mass and function is apparent. Sciatic nerve from old mice did not show a gross increase in oxidative damage, but electron paramagnetic resonance (EPR) studies indicated an increase in the activity of superoxide and/or peroxynitrite in the nerves of old mice at rest that was further exacerbated by electrical stimulation of the nerve to activate muscle contractions. Proteomic analyses indicated that specific redox-sensitive proteins are increased in content in the nerves of old mice that may reflect an adaptation to regulate the increased superoxide/peroxynitrite and maintain redox homoeostasis. Analysis of redox active cysteines showed some increase in reversible oxidation in specific proteins in nerves of old mice, but this was not universally seen across all redox-active cysteines. Detailed analysis of the redox-active cysteine in one protein in the nerve of old mice that is key to redox signalling (Peroxiredoxin 6, Cys 47) showed a minor increase in reversible oxidation that would be compatible with a change in its redox signalling function. In conclusion, the data presented indicate that sciatic nerve from old mice does not show a gross increase in oxidative damage similar to that seen in the TA and other muscles that it innervates. Our results indicate an adaptation to increased

  13. Proximal motor branches from the tibial nerve as direct donors to restore function of the deep fibular nerve for treatment of high sciatic nerve injuries: a cadaveric feasibility study.

    PubMed

    Flores, Leandro Pretto

    2009-12-01

    The results of surgical repair of the fibular division of the sciatic nerve have been considered unsatisfactory, especially if grafts are necessary to reconstruct the nerve. To consider the clinical application of the concept of distal nerve transfer for the treatment of high sciatic nerve injuries, this study aimed to determine detailed anatomic data about the possible donor branches from the tibial nerve that are available for reinnervation of the deep fibular nerve at the level of the popliteal fossa. An anatomic study was performed that included the dissection of the popliteal fossa in 12 lower limbs of 6 formalin-fixed adult cadavers. It focused on the detailed anatomy of the tibial nerve and its branches at the level of the proximal leg as well as the anatomy of the common fibular nerve and its largest divisions at the level of the neck of the fibula, i.e., the deep and superficial fibular nerves. The branches of the tibial nerve destined to the lateral and medial head of the gastrocnemius had a mean length of 43 mm and 35 mm, respectively. The branch to the posterior soleus muscle had a mean length of 65 mm. Intraneural dissection of the common fibular nerve, isolating its deep and superficial fibular divisions, was possible to a proximal mean distance of 71 mm. A tensionless direct suture to the deep fibular nerve was made possible by using the nerve to the lateral head of the gastrocnemius and the nerve to the posterior soleus muscle in all specimens. Direct suture of the nerve to the medial head of the gastrocnemius was possible in all cases except 1. The nerve to the lateral and medial heads of the gastrocnemius and the nerve to the posterior soleus muscle can be used as donors to restore function of the deep fibular nerve in cases of high sciatic nerve injury. However, proximal intraneural dissection of the deep fibular division of the common fibular nerve must also be performed. We recommend that the nerve to the posterior soleus muscle should be the

  14. Control of ventricular excitability by neurons of the dorsal motor nucleus of the vagus nerve

    PubMed Central

    Machhada, Asif; Ang, Richard; Ackland, Gareth L.; Ninkina, Natalia; Buchman, Vladimir L.; Lythgoe, Mark F.; Trapp, Stefan; Tinker, Andrew; Marina, Nephtali; Gourine, Alexander V.

    2015-01-01

    Background The central nervous origins of functional parasympathetic innervation of cardiac ventricles remain controversial. Objective This study aimed to identify a population of vagal preganglionic neurons that contribute to the control of ventricular excitability. An animal model of synuclein pathology relevant to Parkinson’s disease was used to determine whether age-related loss of the activity of the identified group of neurons is associated with changes in ventricular electrophysiology. Methods In vivo cardiac electrophysiology was performed in anesthetized rats in conditions of selective inhibition of the dorsal vagal motor nucleus (DVMN) neurons by pharmacogenetic approach and in mice with global genetic deletion of all family members of the synuclein protein. Results In rats anesthetized with urethane (in conditions of systemic beta-adrenoceptor blockade), muscarinic and neuronal nitric oxide synthase blockade confirmed the existence of a tonic parasympathetic control of cardiac excitability mediated by the actions of acetylcholine and nitric oxide. Acute DVMN silencing led to shortening of the ventricular effective refractory period (vERP), a lowering of the threshold for triggered ventricular tachycardia, and prolongation of the corrected QT (QTc) interval. Lower resting activity of the DVMN neurons in aging synuclein-deficient mice was found to be associated with vERP shortening and QTc interval prolongation. Conclusion Activity of the DVMN vagal preganglionic neurons is responsible for tonic parasympathetic control of ventricular excitability, likely to be mediated by nitric oxide. These findings provide the first insight into the central nervous substrate that underlies functional parasympathetic innervation of the ventricles and highlight its vulnerability in neurodegenerative diseases. PMID:26051529

  15. Ocular Sarcoidosis

    PubMed Central

    Pasadhika, Sirichai; Rosenbaum, James T

    2015-01-01

    Sarcoidosis is one of the leading causes of inflammatory eye disease. Ocular sarcoidosis can involve any part of the eye and its adnexal tissues, and may cause uveitis, episcleritis/scleritis, eyelid abnormalities, conjunctival granuloma, optic neuropathy, lacrimal gland enlargement and orbital inflammation. Glaucoma and cataract can be complications from inflammation itself or adverse effects from therapy. Ophthalmic manifestations can be isolated, or associated with other organ involvement. Patients with ocular sarcoidosis can present with a wide range of clinical presentations and severity. Multi-disciplinary approaches are required to achieve the best treatment outcomes for both ocular and systemic manifestations. PMID:26593141

  16. Characterization of thoracic motor and sensory neurons and spinal nerve roots in canine degenerative myelopathy, a potential disease model of amyotrophic lateral sclerosis.

    PubMed

    Morgan, Brandie R; Coates, Joan R; Johnson, Gayle C; Shelton, G Diane; Katz, Martin L

    2014-04-01

    Canine degenerative myelopathy (DM) is a progressive, adult-onset, multisystem degenerative disease with many features in common with amyotrophic lateral sclerosis (ALS). As with some forms of ALS, DM is associated with mutations in superoxide dismutase 1 (SOD1). Clinical signs include general proprioceptive ataxia and spastic upper motor neuron paresis in pelvic limbs, which progress to flaccid tetraplegia and dysphagia. The purpose of this study was to characterize DM as a potential disease model for ALS. We previously reported that intercostal muscle atrophy develops in dogs with advanced-stage DM. To determine whether other components of the thoracic motor unit (MU) also demonstrated morphological changes consistent with dysfunction, histopathologic and morphometric analyses were conducted on thoracic spinal motor neurons (MNs) and dorsal root ganglia (DRG) and in motor and sensory nerve root axons from DM-affected boxers and Pembroke Welsh corgis (PWCs). No alterations in MNs or motor root axons were observed in either breed. However, advanced-stage PWCs exhibited significant losses of sensory root axons, and numerous DRG sensory neurons displayed evidence of degeneration. These results indicate that intercostal muscle atrophy in DM is not preceded by physical loss of the motor neurons innervating these muscles, nor of their axons. Axonal loss in thoracic sensory roots and sensory neuron death suggest that sensory involvement may play an important role in DM disease progression. Further analysis of the mechanisms responsible for these morphological findings would aid in the development of therapeutic intervention for DM and some forms of ALS.

  17. Regulation of jaw-specific isoforms of myosin-binding protein-C and tropomyosin in regenerating cat temporalis muscle innervated by limb fast and slow motor nerves.

    PubMed

    Kang, Lucia H D; Hoh, Joseph F Y

    2010-11-01

    Cat jaw-closing muscles are a distinct muscle allotype characterized by the expression of masticatory-specific myofibrillar proteins. Transplantation studies showed that expression of masticatory myosin heavy chain (m-MyHC) is promoted by fast motor nerves, but suppressed by slow motor nerves. We investigated whether masticatory myosin-binding protein-C (m-MBP-C) and masticatory tropomyosin (m-Tm) are similarly regulated. Temporalis muscle strips were transplanted into limb muscle beds to allow innervation by fast or slow muscle nerve during regeneration. Regenerated muscles were examined postoperatively up to 168 days by peroxidase IHC using monoclonal antibodies to m-MyHC, m-MBP-C, and m-Tm. Regenerates in both muscle beds expressed fetal and slow MyHCs, m-MyHC, m-MBP-C, and m-Tm during the first 4 weeks. Longer-term regenerates innervated by fast nerve suppressed fetal and slow MyHCs, retaining m-MyHC, m-MBP-C, and m-Tm, whereas fibers innervated by slow nerve suppressed fetal MyHCs and the three masticatory-specific proteins, induced slow MyHC, and showed immunohistochemical characteristics of jaw-slow fibers. We concluded that expression of m-MBP-C and m-Tm is coregulated by m-MyHC and that neural impulses to limb slow muscle are capable of suppressing masticatory-specific proteins and to channel gene expression along the jaw-slow phenotype unique to jaw-closing muscle.

  18. Peripheral nerve palsy by torsional nerve injury.

    PubMed

    Guerra, Waltraud Kleist-Welch; Schroeder, Henry W S

    2011-04-01

    Peripheral nerve palsy caused by torsional nerve injury is rare. Only a few patients have been reported in the literature. The etiology of this type of nerve lesion is poorly understood. To report on 5 patients presenting with peripheral nerve palsy caused by a torsional nerve injury. Five patients presented with 6 upper peripheral nerve palsy involving the axillary nerve (n = 2), musculocutaneous nerve (n = 2), radial nerve (n = 1), and suprascapular nerve (n = 1). There was no history of trauma in 3 patients, but in the other 2 patients, nerve palsy occurred after a traumatic event. Because of a lack of spontaneous recovery, surgical exploration was performed. Torsion of the whole nerve (n = 5) or only 1 fascicle (n = 1) was found. Epifascicular epineurectomy and detorsion, as well as resection of the torsion site with subsequent primary nerve suture, were performed in 3 lesions. Good to excellent recovery of motor function was achieved in all 5 patients. In the last patient who presented with 2 nerve torsions, the follow-up period after the last surgery is too short to allow evaluation. Although not a frequent event, torsional nerve injury should be taken into consideration when dealing with peripheral nerve injuries. Surgical exploration with detorsion or suture results in good recovery.

  19. Release of [3H-noradrenaline from the motor adrenergic nerves of the anococcygeus muscle by lysergic acid diethylamide, tyramine or nerve stimulation.

    PubMed Central

    McGrath, J C; Olverman, H J

    1978-01-01

    1 A method is described for labelling the neuronal noradrenaline (NA) stores of rat anococcygeus with [3H]-NA and detecting subsequent release of 3H from the superfused tissue by nerve stimulation or drugs. 2 Lysergic acid diethylamide (LSD) or tyramine but not barium chloride or carbachol increased the efflux of 3H although each drug produced an equivalent contractile response. This confirms that LDS has an indirect sympathomimetic action. 3 LSD was found to produce a proportionately smaller reduction of the nerve-induced efflux of 3H than of the accompanying contractile response. 4 The inhibition of nerve-induced contractile responses by LSD was shown to be independent of the neuronal uptake of noradrenaline and any post-junctional inhibition demonstrated to be non-specific. PMID:728688

  20. [Third cranial nerve palsy in sphenoid sinusitis].

    PubMed

    Dores, Luís Almeida; Simão, Marco Alveirinho; Marques, Marta Canas; Dias, Éscar

    2014-01-01

    Sphenoid sinus disease is particular not only for its clinical presentation, as well as their complications. Although rare, these may present as cranial nerve deficits, so it is important to have a high index of suspicion and be familiar with its diagnosis and management. Symptoms are often nonspecific, but the most common are headache, changes in visual acuity and diplopia due to dysfunction of one or more ocular motor nerves. The authors report a case of a 59 years-old male, who was referred to the ENT emergency department with frontal headaches for one week which had progressively worsened and were associated, since the last 12 hours, with diplopia caused by left third cranial nerve palsy. Neurologic examination was normal aside from the left third cranial nerve palsy. Anterior and posterior rhinoscopy excluded the presence of nasal masses and purulent rhinorrhea. The CT scan revealed a soft tissue component and erosion of the roof of the left sphenoid sinus. Patient was admitted for intravenous antibiotics and steroids treatment without any benefit after 48 hours. He was submitted to endoscopic sinus surgery with resolution of the symptoms 10 days after surgery. The authors present this case for its rarity focusing on the importance of differential diagnosis in patients with headaches and cranial nerves palsies.

  1. Motor palsies of cranial nerves (excluding VII) after vaccination: reports to the US Vaccine Adverse Event Reporting System.

    PubMed

    Woo, Emily Jane; Winiecki, Scott K; Ou, Alan C

    2014-01-01

    We reviewed cranial nerve palsies, other than VII, that have been reported to the US Vaccine Adverse Event Reporting System (VAERS). We examined patterns for differences in vaccine types, seriousness, age, and clinical characteristics. We identified 68 reports of cranial nerve palsies, most commonly involving the oculomotor (III), trochlear (IV), and abducens (VI) nerves. Isolated cranial nerve palsies, as well as palsies occurring as part of a broader clinical entity, were reported. Forty reports (59%) were classified as serious, suggesting that a cranial nerve palsy may sometimes be the harbinger of a broader and more ominous clinical entity, such as a stroke or encephalomyelitis. There was no conspicuous clustering of live vs. inactivated vaccines. The patient age range spanned the spectrum from infants to the elderly. Independent data may help to clarify whether, when, and to what extent the rates of cranial nerve palsies following particular vaccines may exceed background levels.

  2. European Federation of Neurological Societies/Peripheral Nerve Society guideline on management of multifocal motor neuropathy. Report of a joint task force of the European Federation of Neurological Societies and the Peripheral Nerve Society--first revision.

    PubMed

    2010-12-01

    A European Federation of Neurological Societies/Peripheral Nerve Society consensus guideline on the definition, investigation, and treatment of multifocal motor neuropathy (MMN) was published in 2006. The aim is to revise this guideline. Disease experts considered references retrieved from MEDLINE and Cochrane Systematic Reviews published between August 2004 and July 2009 and prepared statements that were agreed to in an iterative fashion. The Task Force agreed on Good Practice Points to define clinical and electrophysiological diagnostic criteria for MMN, investigations to be considered, and principal recommendations for treatment.

  3. Corneal nerve microstructure in Parkinson's disease.

    PubMed

    Misra, Stuti L; Kersten, Hannah M; Roxburgh, Richard H; Danesh-Meyer, Helen V; McGhee, Charles N J

    2017-03-03

    Ocular surface changes and blink abnormalities are well-established in Parkinson's disease. Blink rate may be influenced by corneal sub-basal nerve density, however, this relationship has not yet been investigated in Parkinson's disease. This case-control study examined the ocular surface in patients with moderately severe Parkinson's disease, including confocal microscopy of the cornea. Fifteen patients with moderately severe Parkinson's disease (modified Hoehn and Yahr grade 3 or 4) and fifteen control participants were recruited. Ophthalmic assessment included slit-lamp examination, blink rate assessment, central corneal aesthesiometry and in vivo corneal confocal microscopy. The effect of disease laterality was also investigated. Of the 15 patients with Parkinson's disease, ten were male and the mean age was 65.5±8.6years. The corneal sub-basal nerve plexus density was markedly reduced in patients with Parkinson's disease (7.56±2.4mm/mm(2)) compared with controls (15.91±2.6mm/mm(2)) (p<0.0001). Corneal sensitivity did not differ significantly between the patients with Parkinson's disease (0.79±1.2mBAR) and the control group (0.26±0.35mBAR), p=0.12. Sub-basal nerve density was not significantly different between the eye ipsilateral to the side of the body with most-severe motor symptoms, and the contralateral eye. There was a significant positive correlation between ACE-R scores and sub-basal corneal nerve density (R(2)=0.66, p=0.02). This is the first study to report a significant reduction in corneal sub-basal nerve density in Parkinson's disease and demonstrate an association with cognitive dysfunction. These results provide further evidence to support the involvement of the peripheral nervous system in Parkinson's disease, previously thought to be a central nervous system disorder.

  4. Ranirestat (AS-3201), a potent aldose reductase inhibitor, reduces sorbitol levels and improves motor nerve conduction velocity in streptozotocin-diabetic rats.

    PubMed

    Matsumoto, Takafumi; Ono, Yoshiyuki; Kurono, Masuo; Kuromiya, Akemi; Nakamura, Keiji; Bril, Vera

    2008-07-01

    Ranirestat (AS-3201) is a novel aldose reductase (AR) inhibitor with potentially beneficial effects on diabetic sensorimotor polyneuropathy. In this study, we performed a kinetic analysis to determine the mode of inhibition of ranirestat on AR and investigated the effects of ranirestat on sorbitol levels in the sciatic nerves and lens of streptozotocin (STZ)-diabetic rats. We also evaluated the effects on motor nerve conduction velocity (MNCV) in STZ-diabetic rats. Kinetic analyses revealed that the ranirestat inhibition of AR is uncompetitive and reversible. In the sciatic nerve and lens of STZ-diabetic rats, single oral administration of ranirestat slightly reduced sorbitol levels. However, repeated oral administration of ranirestat for 5, 21, or 60 days enhanced the reducing effect of the ranirestat on sorbitol levels in the sciatic nerves and lens of STZ-diabetic rats with maximum effects after 21 days of treatment. Finally, repeated oral administration of ranirestat for 21 or 42 days dose-dependently improved the STZ-induced decrease in MNCV in STZ-diabetic rats. These findings demonstrate that repeated oral administration of ranirestat reduces sorbitol accumulation and improves MNCV in STZ-diabetic rats, indicating that ranirestat is an agent for the management of diabetic sensorimotor polyneuropathy.

  5. Third-Degree Hindpaw Burn Injury Induced Apoptosis of Lumbar Spinal Cord Ventral Horn Motor Neurons and Sciatic Nerve and Muscle Atrophy in Rats

    PubMed Central

    Wu, Sheng-Hua; Cheng, Kuang-I; Chai, Chee-Yin; Yeh, Jwu-Lai; Wu, Tai-Cheng; Kwan, Aij-Lie

    2015-01-01

    Background. Severe burns result in hypercatabolic state and concomitant muscle atrophy that persists for several months, thereby limiting patient recovery. However, the effects of burns on the corresponding spinal dermatome remain unknown. This study aimed to investigate whether burns induce apoptosis of spinal cord ventral horn motor neurons (VHMNs) and consequently cause skeletal muscle wasting. Methods. Third-degree hindpaw burn injury with 1% total body surface area (TBSA) rats were euthanized 4 and 8 weeks after burn injury. The apoptosis profiles in the ventral horns of the lumbar spinal cords, sciatic nerves, and gastrocnemius muscles were examined. The Schwann cells in the sciatic nerve were marked with S100. The gastrocnemius muscles were harvested to measure the denervation atrophy. Result. The VHMNs apoptosis in the spinal cord was observed after inducing third-degree burns in the hindpaw. The S100 and TUNEL double-positive cells in the sciatic nerve increased significantly after the burn injury. Gastrocnemius muscle apoptosis and denervation atrophy area increased significantly after the burn injury. Conclusion. Local hindpaw burn induces apoptosis in VHMNs and Schwann cells in sciatic nerve, which causes corresponding gastrocnemius muscle denervation atrophy. Our results provided an animal model to evaluate burn-induced muscle wasting, and elucidate the underlying mechanisms. PMID:25695065

  6. Central command does not suppress baroreflex control of cardiac sympathetic nerve activity at the onset of spontaneous motor activity in the decerebrate cat.

    PubMed

    Matsukawa, Kanji; Ishii, Kei; Asahara, Ryota; Idesako, Mitsuhiro

    2016-10-01

    Our laboratory has reported that central command blunts the sensitivity of the aortic baroreceptor-heart rate (HR) reflex at the onset of voluntary static exercise in animals. We have examined whether baroreflex control of cardiac sympathetic nerve activity (CSNA) and/or cardiovagal baroreflex sensitivity are altered at the onset of spontaneously occurring motor behavior, which was monitored with tibial nerve activity in paralyzed, decerebrate cats. CSNA exhibited a peak increase (126 ± 17%) immediately after exercise onset, followed by increases in HR and mean arterial pressure (MAP). With development of the pressor response, CSNA and HR decreased near baseline, although spontaneous motor activity was not terminated. Atropine methyl nitrate (0.1-0.2 mg/kg iv) with little central influence delayed the initial increase in HR but did not alter the response magnitudes of HR and CSNA, while atropine augmented the pressor response. The baroreflex-induced decreases in CSNA and HR elicited by brief occlusion of the abdominal aorta were challenged at the onset of spontaneous motor activity. Spontaneous motor activity blunted the baroreflex reduction in HR by aortic occlusion but did not alter the baroreflex inhibition of CSNA. Similarly, atropine abolished the baroreflex reduction in HR but did not influence the baroreflex inhibition of CSNA. Thus it is likely that central command increases CSNA and decreases cardiac vagal outflow at the onset of spontaneous motor activity while preserving baroreflex control of CSNA. Accordingly, central command must attenuate cardiovagal baroreflex sensitivity against an excess rise in MAP as estimated from the effect of muscarinic blockade.

  7. The Swimmeret System of Crayfish: A Practical Guide for the Dissection of the Nerve Cord and Extracellular Recordings of the Motor Pattern

    PubMed Central

    Seichter, Henriette A.; Blumenthal, Felix; Smarandache-Wellmann, Carmen R.

    2014-01-01

    Here we demonstrate the dissection of the crayfish abdominal nerve cord. The preparation comprises the last two thoracic ganglia (T4, T5) and the chain of abdominal ganglia (A1 to A6). This chain of ganglia includes the part of the central nervous system (CNS) that drives coordinated locomotion of the pleopods (swimmerets): the swimmeret system. It is known for over five decades that in crayfish each swimmeret is driven by its own independent pattern generating kernel that generates rhythmic alternating activity 1-3. The motor neurons innervating the musculature of each swimmeret comprise two anatomically and functionally distinct populations 4. One is responsible for the retraction (power stroke, PS) of the swimmeret. The other drives the protraction (return stroke, RS) of the swimmeret. Motor neurons of the swimmeret system are able to produce spontaneously a fictive motor pattern, which is identical to the pattern recorded in vivo 1. The aim of this report is to introduce an interesting and convenient model system for studying rhythm generating networks and coordination of independent microcircuits for students’ practical laboratory courses. The protocol provided includes step-by-step instructions for the dissection of the crayfish’s abdominal nerve cord, pinning of the isolated chain of ganglia, desheathing the ganglia and recording the swimmerets fictive motor pattern extracellularly from the isolated nervous system. Additionally, we can monitor the activity of swimmeret neurons recorded intracellularly from dendrites. Here we also describe briefly these techniques and provide some examples. Furthermore, the morphology of swimmeret neurons can be assessed using various staining techniques. Here we provide examples of intracellular (by iontophoresis) dye filled neurons and backfills of pools of swimmeret motor neurons. In our lab we use this preparation to study basic functions of fictive locomotion, the effect of sensory feedback on the activity of the CNS

  8. The swimmeret system of crayfish: a practical guide for the dissection of the nerve cord and extracellular recordings of the motor pattern.

    PubMed

    Seichter, Henriette A; Blumenthal, Felix; Smarandache-Wellmann, Carmen R

    2014-11-25

    Here we demonstrate the dissection of the crayfish abdominal nerve cord. The preparation comprises the last two thoracic ganglia (T4, T5) and the chain of abdominal ganglia (A1 to A6). This chain of ganglia includes the part of the central nervous system (CNS) that drives coordinated locomotion of the pleopods (swimmerets): the swimmeret system. It is known for over five decades that in crayfish each swimmeret is driven by its own independent pattern generating kernel that generates rhythmic alternating activity . The motor neurons innervating the musculature of each swimmeret comprise two anatomically and functionally distinct populations. One is responsible for the retraction (power stroke, PS) of the swimmeret. The other drives the protraction (return stroke, RS) of the swimmeret. Motor neurons of the swimmeret system are able to produce spontaneously a fictive motor pattern, which is identical to the pattern recorded in vivo. The aim of this report is to introduce an interesting and convenient model system for studying rhythm generating networks and coordination of independent microcircuits for students' practical laboratory courses. The protocol provided includes step-by-step instructions for the dissection of the crayfish's abdominal nerve cord, pinning of the isolated chain of ganglia, desheathing the ganglia and recording the swimmerets fictive motor pattern extracellularly from the isolated nervous system. Additionally, we can monitor the activity of swimmeret neurons recorded intracellularly from dendrites. Here we also describe briefly these techniques and provide some examples. Furthermore, the morphology of swimmeret neurons can be assessed using various staining techniques. Here we provide examples of intracellular (by iontophoresis) dye filled neurons and backfills of pools of swimmeret motor neurons. In our lab we use this preparation to study basic functions of fictive locomotion, the effect of sensory feedback on the activity of the CNS, and

  9. Outcomes of Transferring a Healthy Motor Fascicle From the Radial Nerve to a Branch for the Triceps to Recover Elbow Extension in Partial Brachial Plexus Palsy.

    PubMed

    Flores, Leandro Pretto

    2017-03-01

    Triceps reinnervation is an important objective to pursue when repairing the brachial plexus for cases with upper roots injuries, and a number of different techniques have been developed in order to restore elbow extension in such cases. To demonstrate the surgical outcomes associated with the technique of transferring a single healthy motor fascicle from the radial nerve of the affected arm to a branch innervating 1 of the 3 heads of the triceps. A retrospective study of 13 adult patients sustaining an upper trunk syndrome associated with total elbow extension palsy who underwent the proposed technique as part of the surgical planning for reconstruction of the brachial plexus. Outcomes scored as M4 for elbow extension were noted in 9 cases (70%), M3 in 3 (23%), and M1 in 1 subject (7%). No patient considered the postoperative strength for carpal or finger extension as impaired. There were no differences in outcomes by using a fascicle activating carpal or finger extension as donor, as well as regarding the use of the branch to the medial or lateral head of the triceps as the recipient. The technique of transferring a healthy motor fascicle from the radial nerve of the affected side to one of its nonfunctional motor branches to the triceps is an effective and safe procedure for recovering elbow extension function in patients sustaining partial injuries of the brachial plexus.

  10. Iris mammillations in ocular melanocytosis.

    PubMed

    Swann, Peter G

    2001-01-01

    Hyperpigmentation of the ocular tissues and of the skin around the eye is uncommon. In ocular melanosis, the episclera, uveal tract and the angle of the anterior chamber may be involved. Heterochromia iridis may be present, if the iris is affected. In oculodermal melanocytosis or the naevus of Ota, hyperpigmentation of the skin follows the distribution of the first and second divisions of the fifth cranial nerve. This report documents a patient with episcleral pigment, heterochromia iridis and numerous tiny pigmented nodules on the iris (mammillations). The possible significance of these findings is discussed.

  11. Sub-lethal Ocular Trauma (SLOT): Establishing a Standardized Blast Threshold to Facilitate Diagnostic, Early Treatment, and Recovery Studies for Blast Injuries to the Eye and Optic Nerve

    DTIC Science & Technology

    2014-09-01

    previously described components. Once constructed, parts were exported from SolidWorks in the ACIS SAT file format . The SAT part files were...around the pseudocolor map of the protein size distributions in the tissue. Data format as in Figure 28. 43 Figure 31. Average protein...44 Figure 33. MALDI imaging analysis of the location indicated by the gold star in the optic nerve of a traumatized eye. Data format as

  12. Eye Position Feedback in a Model of the Vestibulo-Ocular Reflex for Spino-Cerebellar Ataxia 6

    DTIC Science & Technology

    2007-11-02

    neurodegenerative diseases characterized by progressive instability of posture and gait, incoordination, ocular motor dysfunction, and dysarthria ...characterized by progressive instability of posture and gait, incoordination, ocular motor dysfunction, and dysarthria due to degeneration of cerebellar

  13. The role of the vagus nerve in the migrating motor complex and ghrelin- and motilin-induced gastric contraction in suncus.

    PubMed

    Miyano, Yuki; Sakata, Ichiro; Kuroda, Kayuri; Aizawa, Sayaka; Tanaka, Toru; Jogahara, Takamichi; Kurotani, Reiko; Sakai, Takafumi

    2013-01-01

    The upper gastrointestinal (GI) tract undergoes a temporally coordinated cyclic motor pattern known as the migrating motor complex (MMC) in both dogs and humans during the fasted state. Feeding results in replacement of the MMC by a pattern of noncyclic, intermittent contractile activity termed as postprandial contractions. Although the MMC is known to be stimulated by motilin, recent studies have shown that ghrelin, which is from the same peptide family as motilin, is also involved in the regulation of the MMC. In the present study, we investigated the role of the vagus nerve on gastric motility using conscious suncus-a motilin- and ghrelin-producing small animal. During the fasted state, cyclic MMC comprising phases I, II, and III was observed in both sham-operated and vagotomized suncus; however, the duration and motility index (MI) of phase II was significantly decreased in vagotomized animals. Motilin infusion (50 ng·kg(-1)·min(-1) for 10 min) during phase I had induced phase III-like contractions in both sham-operated and vagotomized animals. Ghrelin infusion (0.1, 0.3, 1, 3, or 10 µg·kg(-1)·min(-1) for 10 min) enhanced the amplitude of phase II MMC in sham-operated animals, but not in vagotomized animals. After feeding, phase I was replaced by postprandial contractions, and motilin infusion (50 ng·kg(-1)·min(-1) for 10 min) did not induce phase III-like contractions in sham-operated suncus. However, in vagotomized suncus, feeding did not evoke postprandial contractions, but exogenous motilin injection strongly induced phase III-like contractions, as noted during the phase I period. Thus, the results indicate that ghrelin stimulates phase II of the MMC via the vagus nerve in suncus. Furthermore, the vagus nerve is essential for initiating postprandial contractions, and inhibition of the phase III-like contractions induced by motilin is highly dependent on the vagus nerve.

  14. Potentiation by tonic A2a-adenosine receptor activation of CGRP-facilitated [3H]-ACh release from rat motor nerve endings.

    PubMed Central

    Correia-de-Sá, P.; Ribeiro, J. A.

    1994-01-01

    1. The effect of calcitonin gene-related peptide (CGRP) on [3H]-acetylcholine ([3H]-ACh) release from motor nerve endings and its interaction with presynaptic facilitatory A2a-adenosine and nicotinic acetylcholine receptors was studied on rat phrenic nerve-hemidiaphragm preparations loaded with [3H]-choline. 2. CGRP (100-400 nM) increased electrically evoked [3H]-ACh release from phrenic nerve endings in a concentration-dependent manner. 3. The magnitude of CGRP excitation increased with the increase of the stimulation pulse duration from 40 microseconds to 1 ms, keeping the frequency, the amplitude and the train length constants. With 1 ms pulses, the evoked [3H]-ACh release was more intense than with 40 microseconds pulse duration. 4. Both the nicotinic acetylcholine receptor agonist, 1,1-dimethyl-4-phenylpiperazinium, and the A2a adenosine receptor agonist, CGS 21680C, increased evoked [3H]-ACh release, but only CGS 21680C potentiated the facilitatory effect of CGRP. This potentiation was prevented by the A2a adenosine receptor antagonist, PD 115,199. 5. Adenosine deaminase prevented the excitatory effect of CGRP (400 nM) on [3H]-ACh release. This effect was reversed by the non-hydrolysable A2a-adenosine receptor agonist, CGS 21680C. 6. The nicotinic antagonist, tubocurarine, did not significantly change, whereas the A2-adenosine receptor antagonist, PD 115,199, blocked the CGRP facilitation. The A1-adenosine receptor antagonist, 1,3-dipropyl-8-cyclopentylxanthine, potentiated the CGRP excitatory effect. 7. The results suggest that the facilitatory effect of CGRP on evoked [3H]-ACh release from rat phrenic motor nerve endings depends on the presence of endogenous adenosine which tonically activates A2a-adenosine receptors.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8004402

  15. Home-based nerve stimulation to enhance effects of motor training in patients in the chronic phase after stroke: a proof-of-principle study.

    PubMed

    Dos Santos-Fontes, Renata Laurenti; Ferreiro de Andrade, Karina Nocelo; Sterr, Annette; Conforto, Adriana Bastos

    2013-01-01

    Somatosensory stimulation in the form of repetitive peripheral nerve stimulation (RPSS) is a promising strategy to improve motor function of the upper limb in chronic stroke. Home-based RPSS may be an alternative to hospital-based RPSS. To investigate the feasibility and safety of an innovative program of home-based RPSS combined with motor training and to collect preliminary data on the efficacy of this program to enhance hand motor function in patients in the chronic phase after stroke. Twenty patients were randomized to either active or sham RPSS associated with daily motor training performed at home over 4 consecutive weeks. All the patients were able to perform tasks of the Jebsen-Taylor Test (JTT). The primary outcome measures were feasibility, evaluated by self-reported compliance with the intervention, and safety (adverse events). Secondary outcomes comprised improvements in hand function in the JTT after end of treatment and after a 4-month follow-up period. There were no relevant adverse events. Compliance with RPSS and motor training was significantly greater in the active group than in the sham group. Upper extremity performance improved significantly more in the active group compared with the sham group at the end of treatment. This difference remained significant 4 months later, even when differences in compliance with motor training were considered. Home-based active RPSS associated with motor training was feasible, was safe, and led to long-lasting enhancement of paretic arm performance in the chronic phase after stroke for those who can perform the JTT. These results point to the need for an efficacy trial.

  16. Experimental beta beta'-iminodipropionitrile (IDPN) neuropathy: neurofilament profile of sensory, motor and autonomic nerves as seen by immunocytochemistry on whole-mount preparations.

    PubMed

    Ferri, G L; Cichi, A; Bastone, A; Gaudio, R M; Frontali, N; Dahl, D

    1994-09-19

    IDPN-induced changes in a variety of sensory, motor and autonomic nerves were studied by whole-mount immunocytochemistry. A full range of proximo-distal accumulations of neurofilament-like material was found, from paranuclear round bodies in perikarya to distal and preterminal axonal dilations. Conversely, both terminal areas and nodal-paranodal regions of myelinated axons showed striking, sharply localized loss of neurofilament-immunostaining. The latter change, when transport of neurofilaments is halted by IDPN, may indicate their local processing and/or differential transport at nodal-paranodal regions.

  17. Enhanced adenoviral gene delivery to motor and dorsal root ganglion neurons following injection into demyelinated peripheral nerves.

    PubMed

    Zhang, Yongjie; Zheng, Yiyan; Zhang, Yi Ping; Shields, Lisa B E; Hu, Xiaoling; Yu, Panpan; Burke, Darlene A; Wang, Heming; Jun, Cai; Byers, Jonathan; Whittemore, Scott R; Shields, Christopher B

    2010-08-15

    Injection of viral vectors into peripheral nerves may transfer specific genes into their dorsal root ganglion (DRG) neurons and motoneurons. However, myelin sheaths of peripheral axons block the entry of viral particles into nerves. We studied whether mild, transient peripheral nerve demyelination prior to intraneural viral vector injection would enhance gene transfer to target DRG neurons and motoneurons. The right sciatic nerve of C57BL/6 mice was focally demyelinated with 1% lysolecithin, and the left sciatic nerve was similarly injected with saline (control). Five days after demyelination, 0.5 microl of Ad5-GFP was injected into both sciatic nerves at the site of previous injection. The effectiveness of gene transfer was evaluated by counting GFP(+) neurons in the DRGs and ventral horns. After peripheral nerve demyelination, there was a fivefold increase in the number of infected DRG neurons and almost a 15-fold increase in the number of infected motoneurons compared with the control, nondemyelinated side. Focal demyelination reduced the myelin sheath barrier, allowing greater virus-axon contact. Increased CXADR expression on the demyelinated axons facilitated axoplasmic viral entry. No animals sustained any prolonged neurological deficits. Increased gene delivery into DRG neurons and motoneurons may provide effective treatment for amyotrophic lateral sclerosis, pain, and spinal cord injury.

  18. Ocular toxocariasis.

    PubMed

    Arevalo, J Fernando; Espinoza, Juan V; Arevalo, Fernando A

    2013-01-01

    Ocular toxocariasis is an uncommon worldwide parasitic infection that affects mostly children and is found in both rural and metropolitan areas. In many parts of the world, parasitic infections of the eye are a major cause of blindness. The diagnosis of toxocariasis is essentially clinical, based on the lesion morphology and supportive laboratory data such as serum enzyme-linked immunosorbent assay (ELISA) titers and ELISA Toxocara titers on aqueous humor; other diagnostic methods are imaging studies including optical coherence tomography, fluorescein angiography, computed tomography, and ocular ultrasound. Treatment is directed at complications arising from intraocular inflammation and vitreous membrane traction. Early vitrectomy may be of value both diagnostically and therapeutically.

  19. Ocular Pathology.

    PubMed

    Bauer, Bianca S

    2015-08-01

    Although not comprehensive of all ocular conditions in the equine species, this article concentrates on various ophthalmic conditions observed in the horse where laboratory diagnostics are recommended. The importance of laboratory diagnostic testing cannot be underestimated with equine ophthalmic disease. In many cases, laboratory diagnostics can aid in obtaining an early diagnosis and determining appropriate therapy, which in turn, can provide a better prognosis. In unfortunate cases where ocular disease results in a blind, painful eye necessitating enucleation, light microscopic evaluation is imperative to determine or confirm the cause of the blindness and provide a prognosis for the contralateral eye.

  20. Ocular manifestations in systemic lupus erythematosus.

    PubMed

    Silpa-archa, Sukhum; Lee, Joan J; Foster, C Stephen

    2016-01-01

    Systemic lupus erythematosus (SLE) can involve many parts of the eye, including the eyelid, ocular adnexa, sclera, cornea, uvea, retina and optic nerve. Ocular manifestations of SLE are common and may lead to permanent blindness from the underlying disease or therapeutic side effects. Keratoconjunctivitis sicca is the most common manifestation. However, vision loss may result from involvement of the retina, choroid and optic nerve. Ocular symptoms are correlated to systemic disease activity and can present as an initial manifestation of SLE. The established treatment includes prompt systemic corticosteroids, steroid-sparing immunosuppressive drugs and biological agents. Local ocular therapies are options with promising efficacy. The early recognition of disease and treatment provides reduction of visual morbidity and mortality.

  1. Ocular morbidity in leprosy patients with lagophthalmos.

    PubMed

    Khandpur, S; Robertson, S J; Rao, P S S

    2009-01-01

    Lagophthalmos is a well known complication in leprosy due to the involvement of seventh cranial nerve resulting in incomplete closure of the eyelids. The real magnitude of ocular morbidity as a consequence of lagophthalmos is unknown, as several ocular complications can occur independently due to involvement of the fifth (trigeminal) nerve or due to secondary infection. Therefore, a study was designed to carefully examine the eyes of 100 consecutive leprosy patients with lagophthalmos seeking treatment at a leprosy referral centre in Delhi. Among the eyes examined, 145 had lagophthalmos. The symptomatology and anterior-posterior chamber morbidity in eyes with lagophthalmos were significantly higher as compared to unaffected eyes. Significantly, higher morbidity was seen regardless of sex or type of leprosy or deformity. Capacity building of the health professionals regarding ocular morbidity and increased emphasis on the importance of self care among patients can significantly reduce ocular morbidity.

  2. [Neuromuscular spindles of the extrinsic ocular musculature of the moufflon].

    PubMed

    Palmieri, G; Farina, V; Sanna, L; Asole, A; Panu, R; Piu, C

    1989-01-01

    Proprioceptive innervation of moufflon extrinsic ocular musculature and m. levator palpebrae superioris was studied. Muscle spindles and Golgi tendon organs were found. The first ones are usually between 1st and 2nd order muscle fascicles. The muscle spindles are highly represented in the extrinsic ocular muscles, but less numerous in m. levator palpebrae superioris. Their number varies according to muscles and individuals. In the same subject, also the ratio between the number of the muscle spindles found in m. rectus dorsalis and that of m. levator palpebrae superioris was examined. Besides, the histological structure of the intrafusal fascicles was investigated. Particular attention was devoted to the nerve supply of the muscle spindle. By means of impregnating methods, sensory and motor endings were identified. Primary and secondary sensory endings only in a few cases showed their usual pattern: motor fibres can end in form of plates or trails. Golgi tendon organs were observed between the tendon and the muscular tissue and are always less numerous.

  3. Ocular phototherapy.

    PubMed

    Singh, A D

    2013-02-01

    Phototherapy can be translated to mean 'light or radiant energy-induced treatment.' Lasers have become the exclusive source of light or radiant energy for all applications of phototherapy. Depending on the wavelength, intensity, and duration of exposure, tissues can either absorb the energy (photocoagulation, thermotherapy, and photodynamic therapy (PDT)) or undergo ionization (photodisruption). For phototherapy to be effective, the energy has to be absorbed by tissues or more specifically by naturally occurring pigment (xanthophyll, haemoglobin, and melanin) within them. In tissues or tumours that lack natural pigment, dyes (verteporphin, Visudyne) with narrow absorption spectrum can be injected intravenously that act as focal absorbent of laser energy after they have preferentially localized within the tumour. Ocular phototherapy has broad applications in treatment of ocular tumours. Laser photocoagulation, thermotherapy, and PDT can be delivered with low rates of complications and with ease in the outpatient setting. Review of the current literature suggests excellent results when these treatments are applied for benign tumours, particularly for vascular tumours such as circumscribed choroidal haemangioma. For primary malignant tumours, such as choroidal melanoma, thermotherapy, and PDT do not offer local tumour control rates that are equivalent or higher than those achieved with plaque or proton radiation therapy. However, for secondary malignant tumours (choroidal metastases), thermotherapy and PDT can be applied as a palliative treatment. Greater experience is necessary to fully comprehend risks, comparative benefits, and complication of ocular phototherapy of ocular tumours.

  4. Use of the accelerating rotarod for assessment of motor performance decrement induced by potential anticonvulsant compounds in nerve agent poisoning. (Reannouncement with new availability information)

    SciTech Connect

    Capacio, B.R.; Harris, L.W.; Anderson, D.R.; Lennox, W.J.; Gales, V.

    1992-12-31

    The accelerating rotarod was used to assess motor performance decrement in rats after administration of candidate anticonvulsant compounds (acetazolamide, amitriptyline, chlordiazepoxide, diazepan, diazepam-lysine, lorazepam, loprazolam, midazolam, phenobarbital and scopolamine) against nerve agent poisoning. AH compounds were tested as the commercially available injectable preparation except for diazepam-lysine and loprazolam, which are not FDA approved. A peak effect time, as well as a dose to decrease performance time by 50% from control (PDD50), was determined. The calculated PDD50 (micrometer ol/kg) values and peak effect tunes were midazolam, 1.16 at 15 min; loprazolam, 1.17 at 15 min; diazepam-lysine, 4.17 at 30 min; lorazepwn, 4.98 at 15 min; diazepam, 5.27 at 15 min; phenobarbital, 101.49 at 45 min; chlordiazepoxide, 159.21 at 30 min; scopolamine, amitriptyline and acetazolamide did not demonstrate a performance decrement at any of the doses tested. The PDD50 values were compared with doses which have been utilized against nerve agent-induced convulsions or published ED50 values from standard anticonvulsant screening tests (maximal electroshock MES and subcutaneous pentylenetetrazol (scMET)). I serve agents, anticonvulsants, diazepam, accelerating rotarod, motor performance.

  5. A mouse ocular explant model that enables the study of living optic nerve head events after acute and chronic intraocular pressure elevation: Focusing on retinal ganglion cell axons and mitochondria.

    PubMed

    Kimball, Elizabeth C; Pease, Mary E; Steinhart, Matthew R; Oglesby, Ericka N; Pitha, Ian; Nguyen, Cathy; Quigley, Harry A

    2017-07-01

    We developed an explant model of the mouse eye and optic nerve that facilitates the study of retinal ganglion cell axons and mitochondria in the living optic nerve head (ONH) in an ex vivo environment. Two transgenic mouse strains were used, one expressing yellow fluorescent protein in selected axons and a second strain expressing cyan fluorescent protein in all mitochondria. We viewed an explanted mouse eye and optic nerve by laser scanning microscopy at and behind the ONH, the site of glaucoma injury. Explants from previously untreated mice were studied with the intraocular pressure (IOP) set artificially at normal or elevated levels for several hours. Explants were also studied from eyes that had undergone chronic IOP elevation from 14 h to 6 weeks prior to ex vivo study. Image analysis in static images and video of individual mitochondria or axonal structure determined effects of acute and chronic IOP elevation. At normal IOP, fluorescent axonal structure was stable for up to 3 h under ex vivo conditions. After chronic IOP elevation, axonal integrity index values indicated fragmentation of axon structure in the ONH. In mice with fluorescent mitochondria, the normal density decreased with distance behind the ONH by 45% (p = 0.002, t-test). Density increased with prior chronic IOP elevation to 21,300 ± 4176 mitochondria/mm(2) compared to control 16,110 ± 3159 mitochondria/mm(2) (p = 0.025, t-test), but did not increase significantly after 4 h, acute IOP elevation (1.5% decrease in density, p = 0.83, t-test). Mean normal mitochondrial length of 2.3 ± 1.4 μm became 13% smaller after 4 h of IOP elevation ex vivo compared to baseline (p = 0.015, t-test, N-10). Normal mitochondrial speed of movement was significantly slower in the anterograde direction (towards the brain) than retrograde, but there were more mitochondria in motion and traveling longer lengths in anterograde direction. The percent of mitochondria in motion decreased by >50

  6. The impact of high-frequency magnetic stimulation of peripheral nerves: muscle hardness, venous blood flow, and motor function of upper extremity in healthy subjects.

    PubMed

    Okudera, Yoshihiko; Matsunaga, Toshiki; Sato, Mineyoshi; Chida, Satoaki; Hatakeyama, Kazutoshi; Watanabe, Motoyuki; Shimada, Yoichi

    2015-01-01

    The purpose of this study was to investigate the impact of high-frequency peripheral nerve magnetic stimulation on the upper limb function. Twenty-five healthy adults (16 men and 9 women) participated in this study. The radial nerve of the non-dominant hand was stimulated by high-frequency magnetic stimulation device. A total of 600 impulses were applied at a frequency of 20 Hz and intensity of 1.2 resting motor threshold (rMT). At three time points (before, immediately after, and 15 min after stimulation), muscle hardness of the extensor digitorum muscle on the stimulated side was measured using a mechanical tissue hardness meter and a shear wave imaging device, cephalic venous blood flow on the stimulated side was measured using an ultrasound system, and the Box and Block test (BBT) was performed. Mechanical tissue hardness results did not show any significant differences between before, immediately after, and 15 min after stimulation. Measurements via shear wave imaging showed that muscle hardness significantly decreased both immediately and 15 min after stimulation compared to before stimulation (P < 0.05). Peripheral venous blood flow and BBT score significantly increased both immediately and 15 min after stimulation compared to before stimulation (P < 0.01). High-frequency peripheral nerve magnetic stimulation can achieve effects similar to electrical stimulation in a less invasive manner, and may therefore become an important element in next-generation rehabilitation.

  7. Air bags and ocular injuries.

    PubMed Central

    Stein, J D; Jaeger, E A; Jeffers, J B

    1999-01-01

    PURPOSE: This investigation retrospectively examined ocular injuries associated with air bag deployment to gain a better appreciation of potential risk factors in motor vehicle accidents. National statistics regarding the efficacy of air bags were reviewed. METHODS: Review of the literature from 1991 to 1998 identified 44 articles describing 97 patients with air-bag-induced ocular injuries. Variables extracted from each case were age, sex, height, position in the car, eye wear, vehicle impact speed, visual acuity, and specific ocular injuries. RESULTS: Corneal abrasions occurred in 49% of occupants, hyphemas in 43%, vitreous or retinal hemorrhages in 25%, and retinal tears or detachments in 15%. The globe was ruptured in 10 patients. Patients involved in higher-speed accidents (over 30 mph) sustained a greater percentage of vitreous or retinal hemorrhages and traumatic cataracts, while those at slower speeds were more prone to retinal tears or detachments. In a subset of 14 patients with serious ocular injuries, the impact speed of 11 patients was recorded at 30 mph or less. Slower speed may be a risk factor for some ocular injuries. Occupant height was not a significant factor. National statistics confirm that air bags reduce fatalities in motor vehicle accidents. However, children sitting in the front seat without a seat belt and infants in passenger-side rear-facing car seats are at risk for fatal injury. CONCLUSION: Air bags combined with seat belts are an effective means of reducing injury and death in adults during motor vehicle accidents. However, this study has documented a wide variety of ocular injuries associated with air bag deployment. It is hoped that researchers can develop modifications that continue to save lives while minimizing additional harm. Images FIGURE 1 FIGURE 2A FIGURE 2B FIGURE 2C FIGURE 2D FIGURE 3A FIGURE 3B FIGURE 4 FIGURE 5 FIGURE 7 FIGURE 8 PMID:10703118

  8. Air bags and ocular injuries.

    PubMed

    Stein, J D; Jaeger, E A; Jeffers, J B

    1999-01-01

    This investigation retrospectively examined ocular injuries associated with air bag deployment to gain a better appreciation of potential risk factors in motor vehicle accidents. National statistics regarding the efficacy of air bags were reviewed. Review of the literature from 1991 to 1998 identified 44 articles describing 97 patients with air-bag-induced ocular injuries. Variables extracted from each case were age, sex, height, position in the car, eye wear, vehicle impact speed, visual acuity, and specific ocular injuries. Corneal abrasions occurred in 49% of occupants, hyphemas in 43%, vitreous or retinal hemorrhages in 25%, and retinal tears or detachments in 15%. The globe was ruptured in 10 patients. Patients involved in higher-speed accidents (over 30 mph) sustained a greater percentage of vitreous or retinal hemorrhages and traumatic cataracts, while those at slower speeds were more prone to retinal tears or detachments. In a subset of 14 patients with serious ocular injuries, the impact speed of 11 patients was recorded at 30 mph or less. Slower speed may be a risk factor for some ocular injuries. Occupant height was not a significant factor. National statistics confirm that air bags reduce fatalities in motor vehicle accidents. However, children sitting in the front seat without a seat belt and infants in passenger-side rear-facing car seats are at risk for fatal injury. Air bags combined with seat belts are an effective means of reducing injury and death in adults during motor vehicle accidents. However, this study has documented a wide variety of ocular injuries associated with air bag deployment. It is hoped that researchers can develop modifications that continue to save lives while minimizing additional harm.

  9. Ocular manifestations of Mycoplasma pneumoniae infection.

    PubMed

    Salzman, M B; Sood, S K; Slavin, M L; Rubin, L G

    1992-05-01

    Ocular manifestations of Mycoplasma pneumoniae infection, other than conjunctivitis, are uncommon. Optic disk swelling, optic nerve atrophy, retinal exudates and hemorrhages, and cranial nerve palsies have been infrequently reported. We describe a 15-year-old patient who developed bilateral optic disk edema and iritis during an acute infection with M. pneumoniae and review the world literature on findings associated with ocular manifestations of infection with this pathogen. Although our patient experienced complete resolution of iritis and optic disk edema after 6 weeks, several patients described in the literature have experienced permanent sequelae as a result of optic neuropathy.

  10. Purinergic receptors in ocular inflammation.

    PubMed

    Guzman-Aranguez, Ana; Gasull, Xavier; Diebold, Yolanda; Pintor, Jesús

    2014-01-01

    Inflammation is a complex process that implies the interaction between cells and molecular mediators, which, when not properly "tuned," can lead to disease. When inflammation affects the eye, it can produce severe disorders affecting the superficial and internal parts of the visual organ. The nucleoside adenosine and nucleotides including adenine mononucleotides like ADP and ATP and dinucleotides such as P(1),P(4)-diadenosine tetraphosphate (Ap4A), and P(1),P(5)-diadenosine pentaphosphate (Ap5A) are present in different ocular locations and therefore they may contribute/modulate inflammatory processes. Adenosine receptors, in particular A2A adenosine receptors, present anti-inflammatory action in acute and chronic retinal inflammation. Regarding the A3 receptor, selective agonists like N(6)-(3-iodobenzyl)-5'-N-methylcarboxamidoadenosine (CF101) have been used for the treatment of inflammatory ophthalmic diseases such as dry eye and uveoretinitis. Sideways, diverse stimuli (sensory stimulation, large intraocular pressure increases) can produce a release of ATP from ocular sensory innervation or after injury to ocular tissues. Then, ATP will activate purinergic P2 receptors present in sensory nerve endings, the iris, the ciliary body, or other tissues surrounding the anterior chamber of the eye to produce uveitis/endophthalmitis. In summary, adenosine and nucleotides can activate receptors in ocular structures susceptible to suffer from inflammatory processes. This involvement suggests the possible use of purinergic agonists and antagonists as therapeutic targets for ocular inflammation.

  11. Purinergic Receptors in Ocular Inflammation

    PubMed Central

    Guzman-Aranguez, Ana; Gasull, Xavier; Diebold, Yolanda; Pintor, Jesús

    2014-01-01

    Inflammation is a complex process that implies the interaction between cells and molecular mediators, which, when not properly “tuned,” can lead to disease. When inflammation affects the eye, it can produce severe disorders affecting the superficial and internal parts of the visual organ. The nucleoside adenosine and nucleotides including adenine mononucleotides like ADP and ATP and dinucleotides such as P1,P4-diadenosine tetraphosphate (Ap4A), and P1,P5-diadenosine pentaphosphate (Ap5A) are present in different ocular locations and therefore they may contribute/modulate inflammatory processes. Adenosine receptors, in particular A2A adenosine receptors, present anti-inflammatory action in acute and chronic retinal inflammation. Regarding the A3 receptor, selective agonists like N6-(3-iodobenzyl)-5′-N-methylcarboxamidoadenosine (CF101) have been used for the treatment of inflammatory ophthalmic diseases such as dry eye and uveoretinitis. Sideways, diverse stimuli (sensory stimulation, large intraocular pressure increases) can produce a release of ATP from ocular sensory innervation or after injury to ocular tissues. Then, ATP will activate purinergic P2 receptors present in sensory nerve endings, the iris, the ciliary body, or other tissues surrounding the anterior chamber of the eye to produce uveitis/endophthalmitis. In summary, adenosine and nucleotides can activate receptors in ocular structures susceptible to suffer from inflammatory processes. This involvement suggests the possible use of purinergic agonists and antagonists as therapeutic targets for ocular inflammation. PMID:25132732

  12. Sacculo-ocular reflex connectivity in cats.

    PubMed

    Isu, N; Graf, W; Sato, H; Kushiro, K; Zakir, M; Imagawa, M; Uchino, Y

    2000-04-01

    The otolith system contributes to the vestibulo-ocular reflexes (VOR) when the head moves linearly in the horizontal plane or tilts relative to gravity. The saccules are thought to detect predominantly accelerations along the gravity vector. Otolith-induced vertical eye movements following vertical linear accelerations are attributed to the saccules. However, information on the neural circuits of the sacculo-ocular system is limited, and the effects of saccular inputs on extraocular motoneurons remain unclear. In the present study, synaptic responses to saccular-nerve stimulation were recorded intracellularly from identified motoneurons of all twelve extraocular muscles. Experiments were successfully performed in eleven cats. Individual motoneurons of the twelve extraocular muscles--the bilateral superior recti (SR), inferior recti (IR), superior obliques (SO), inferior obliques (IO), lateral recti (LR), and medial recti (MR) were identified antidromically following bipolar stimulation of their respective nerves. The saccular nerve was selectively stimulated by a pair of tungsten electrodes after removing the utricular nerve and the ampullary nerves of the semicircular canals. Stimulus intensities were determined from the stimulus-response curves of vestibular N1 field potentials in order to avoid current spread. Intracellular recordings were performed from 129 extraocular motoneurons. The majority of the neurons showed no response to saccular-nerve stimulation. In 17 (30%) of 56 extraocular motoneurons related to vertical eye movements (bilateral SR and IR), depolarizing and/or hyperpolarizing postsynaptic potentials (PSPs) were observed in response to saccular-nerve stimulation. The latencies of PSPs ranged from 2.3 to 8.9 ms, indicating that the extraocular motoneurons received neither monosynaptic nor disynaptic inputs from saccular afferents. The majority of the latencies of the depolarization, including depolarization-hyperpolarization, were in the range of 2

  13. Ocular metastases

    PubMed Central

    Cohen, V M L

    2013-01-01

    The eye is a rare site for disseminated malignancy because of the absence of a lymphatic system. Metastases to the ocular structures occur by haematogenous spread and therefore the parts of the eye with the best vascular supply are most likely to be affected. Many patients with Stage 4 carcinomatosis (distal metastatic spread) already have a history of a previous primary cancer. However, this is not always the case for lung cancer as this can metastasise early to the uveal tract and therefore the ophthalmologist may be the first to discover the presence of terminal metastatic disease. Broadly speaking, treatment options are focused on improving the patients' quality of life if visual acuity is threatened. Long-term side effects of treatment need to be considered as systemic cancer treatments and therefore patient life expectancy is improving. In this manuscript, presented at the Cambridge symposium 2012, the diagnosis and challenges involved in the management of ocular metastases are presented. PMID:23222564

  14. Ocular onchocerciasis

    PubMed Central

    Thylefors, B.

    1978-01-01

    Well over 20 million people in the world are infected with Onchocerca volvulus and it is probable that 200 000-500 000 people are blind as a result of this infection, which is the most important cause of blindness in certain areas of Africa and Latin America. Treatment of the disease is difficult and often produces serious adverse reactions in the patient. Combined use of diethylcarbamazine citrate and suramin is still the most suitable form of treatment. Screening for the early detection of cases at high risk of ocular manifestations must be organized, and their treatment undertaken, if blindness is to be avoided. Prevention of ocular onchocerciasis is feasible, using vector control methods to reduce transmission, but the procedures are costly and may have to be maintained for many years. Research is needed to improve treatment and to find a chemoprophylactic agent or a preventive vaccine. PMID:307448

  15. Tail Nerve Electrical Stimulation and Electro-Acupuncture Can Protect Spinal Motor Neurons and Alleviate Muscle Atrophy after Spinal Cord Transection in Rats.

    PubMed

    Zhang, Yu-Ting; Jin, Hui; Wang, Jun-Hua; Wen, Lan-Yu; Yang, Yang; Ruan, Jing-Wen; Zhang, Shu-Xin; Ling, Eng-Ang; Ding, Ying; Zeng, Yuan-Shan

    2017-01-01

    Spinal cord injury (SCI) often results in death of spinal neurons and atrophy of muscles which they govern. Thus, following SCI, reorganizing the lumbar spinal sensorimotor pathways is crucial to alleviate muscle atrophy. Tail nerve electrical stimulation (TANES) has been shown to activate the central pattern generator (CPG) and improve the locomotion recovery of spinal contused rats. Electroacupuncture (EA) is a traditional Chinese medical practice which has been proven to have a neural protective effect. Here, we examined the effects of TANES and EA on lumbar motor neurons and hindlimb muscle in spinal transected rats, respectively. From the third day postsurgery, rats in the TANES group were treated 5 times a week and those in the EA group were treated once every other day. Four weeks later, both TANES and EA showed a significant impact in promoting survival of lumbar motor neurons and expression of choline acetyltransferase (ChAT) and ameliorating atrophy of hindlimb muscle after SCI. Meanwhile, the expression of neurotrophin-3 (NT-3) in the same spinal cord segment was significantly increased. These findings suggest that TANES and EA can augment the expression of NT-3 in the lumbar spinal cord that appears to protect the motor neurons as well as alleviate muscle atrophy.

  16. Tail Nerve Electrical Stimulation and Electro-Acupuncture Can Protect Spinal Motor Neurons and Alleviate Muscle Atrophy after Spinal Cord Transection in Rats

    PubMed Central

    Zhang, Yu-Ting; Jin, Hui; Wang, Jun-Hua; Wen, Lan-Yu; Yang, Yang; Ruan, Jing-Wen; Zhang, Shu-Xin; Ling, Eng-Ang

    2017-01-01

    Spinal cord injury (SCI) often results in death of spinal neurons and atrophy of muscles which they govern. Thus, following SCI, reorganizing the lumbar spinal sensorimotor pathways is crucial to alleviate muscle atrophy. Tail nerve electrical stimulation (TANES) has been shown to activate the central pattern generator (CPG) and improve the locomotion recovery of spinal contused rats. Electroacupuncture (EA) is a traditional Chinese medical practice which has been proven to have a neural protective effect. Here, we examined the effects of TANES and EA on lumbar motor neurons and hindlimb muscle in spinal transected rats, respectively. From the third day postsurgery, rats in the TANES group were treated 5 times a week and those in the EA group were treated once every other day. Four weeks later, both TANES and EA showed a significant impact in promoting survival of lumbar motor neurons and expression of choline acetyltransferase (ChAT) and ameliorating atrophy of hindlimb muscle after SCI. Meanwhile, the expression of neurotrophin-3 (NT-3) in the same spinal cord segment was significantly increased. These findings suggest that TANES and EA can augment the expression of NT-3 in the lumbar spinal cord that appears to protect the motor neurons as well as alleviate muscle atrophy. PMID:28744378

  17. Usefulness of intraoperative monitoring of oculomotor and abducens nerves during surgical treatment of the cavernous sinus meningiomas.

    PubMed

    Kaspera, Wojciech; Adamczyk, Piotr; Ślaska-Kaspera, Aleksandra; Ładziński, Piotr

    2015-03-01

    We analyzed the usefulness and prognostic value of intraoperative monitoring for identification of the oculomotor (III) and the abducens (VI) nerve in patients with cavernous sinus meningiomas. 43 patients diagnosed with cavernous sinus meningiomas were divided according to their topography. Function of the nerves was scored on original clinical and neurophysiological scales. The percentage of nerves identified correctly with the monitoring was significantly higher (91% vs. 53% for nerve III and 70% vs. 23% for nerve VI, p<0.001). The fractions of nerves III and VI identified correctly by means of the monitoring were significantly higher in the case of tumors with intra- and extracavernous location (89% vs. 32%, p<0.01) and intracavernous tumors (80% vs. 20%, p<0.05), respectively. The quality of post-resection recording correlated with functional status of both the nerves determined 9 months after the surgery (R=0.51, p<0.001 for nerve III and R=0.57, p<0.01 for nerve VI). Even a trace or pathological response to the post-resection stimulation was associated with improved functional status (90% vs. 50%, p<0.05 for nerve III and 93% vs. 38%, p<0.01 for nerve VI). Neurophysiological monitoring of ocular motor nerves enables their intraoperative identification during resections of the cavernous sinus meningiomas. Intraoperative monitoring of nerve III is particularly important in the case of tumors with extra- and intracavernous location, and the monitoring of nerve VI in the case of intracavernous tumors. The outcome of the post-resection monitoring has prognostic value with regard to the clinical status of the nerves on long-term follow-up. Copyright © 2014 Medical University of Bialystok. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  18. Subconjunctival hemorrhage and vision loss after regional ocular anesthesia.

    PubMed

    Behera, Umesh Chandra; Panda, Lapam; Gupta, Sumi; Modi, Rohit Ramesh

    2017-04-22

    To report two cases of retinal vascular occlusion and associated subconjunctival hemorrhage in needle optic nerve injury during local bulbar anesthesia. Surgical records of these two subjects who presented with acute vision loss after cataract extraction were studied, and systemic workup and ocular imaging were carried out to establish the cause. Computerized tomography showed evidence of optic nerve injury. Subconjunctival hemorrhage could be an associated clinical finding in hypodermic needle injury-related retinal vascular occlusion during ocular anesthesia.

  19. Ligation of mouse L4 and L5 spinal nerves produces robust allodynia without major motor function deficit.

    PubMed

    Ye, Gui-Lan; Savelieva, Katerina V; Vogel, Peter; Baker, Kevin B; Mason, Sara; Lanthorn, Thomas H; Rajan, Indrani

    2015-01-01

    Spinal nerve L5/L6 ligation (SNL) in rats has become the standard for mechanistic studies of peripheral neuropathy and screening for novel analgesics. Conventional SNL in our hybrid mice resulted in a wide range of allodynia. Anatomical evaluation indicated that a variable number of lumbar vertebrae existed, resulting in L4/L5 or L5/L6 being ligated. Surprisingly, L4/L5 ligation did not result in ipsilateral hind limb paralysis and produced robust allodynia. Following a recent report that the mouse L4 neural segment is homologous with rat L5 we generated L4, L5 or both L4 and L5 (L4/L5) ligations in C57 mice after establishing a modified set of surgical landmarks. In contrast to rats, L4 ligation in these mice did not result in hind limb paralysis. Robust allodynia was observed in all three ligation groups. Nerve degeneration confirmed that L4 and L5, respectively, are primary contributors to the tibial and sural branches of the sciatic nerve in mice. A larger von Frey sensitive area reflected the wider distribution of Wallerian degeneration in the hindlimb of L4- compared to L5-ligated mice. Ligation of mouse L4 and L5 spinal nerves produces consistent, robust neuropathic pain behaviors and is suitable as a model for investigating mechanisms of neuropathic pain and for testing of novel analgesics. Gabapentin, used as a validation drug in neuropathic pain models and as a reference compound for novel analgesics, significantly reduced allodynia in the mice tested (L4/L5 ligations). Given the ease of surgery, robust allodynia, and larger von Frey sensitive area, we conclude that combined ligation of spinal nerves L4 and L5 optimizes the SNL model in mice.

  20. Primary sensory and motor cortex excitability are co-modulated in response to peripheral electrical nerve stimulation.

    PubMed

    Schabrun, Siobhan M; Ridding, Michael C; Galea, Mary P; Hodges, Paul W; Chipchase, Lucinda S

    2012-01-01

    Peripheral electrical stimulation (PES) is a common clinical technique known to induce changes in corticomotor excitability; PES applied to induce a tetanic motor contraction increases, and PES at sub-motor threshold (sensory) intensities decreases, corticomotor excitability. Understanding of the mechanisms underlying these opposite changes in corticomotor excitability remains elusive. Modulation of primary sensory cortex (S1) excitability could underlie altered corticomotor excitability with PES. Here we examined whether changes in primary sensory (S1) and motor (M1) cortex excitability follow the same time-course when PES is applied using identical stimulus parameters. Corticomotor excitability was measured using transcranial magnetic stimulation (TMS) and sensory cortex excitability using somatosensory evoked potentials (SEPs) before and after 30 min of PES to right abductor pollicis brevis (APB). Two PES paradigms were tested in separate sessions; PES sufficient to induce a tetanic motor contraction (30-50 Hz; strong motor intensity) and PES at sub motor-threshold intensity (100 Hz). PES applied to induce strong activation of APB increased the size of the N(20)-P(25) component, thought to reflect sensory processing at cortical level, and increased corticomotor excitability. PES at sensory intensity decreased the size of the P25-N33 component and reduced corticomotor excitability. A positive correlation was observed between the changes in amplitude of the cortical SEP components and corticomotor excitability following sensory and motor PES. Sensory PES also increased the sub-cortical P(14)-N(20) SEP component. These findings provide evidence that PES results in co-modulation of S1 and M1 excitability, possibly due to cortico-cortical projections between S1 and M1. This mechanism may underpin changes in corticomotor excitability in response to afferent input generated by PES.

  1. Primary Sensory and Motor Cortex Excitability Are Co-Modulated in Response to Peripheral Electrical Nerve Stimulation

    PubMed Central

    Schabrun, Siobhan M.; Ridding, Michael C.; Galea, Mary P.; Hodges, Paul W.; Chipchase, Lucinda S.

    2012-01-01

    Peripheral electrical stimulation (PES) is a common clinical technique known to induce changes in corticomotor excitability; PES applied to induce a tetanic motor contraction increases, and PES at sub-motor threshold (sensory) intensities decreases, corticomotor excitability. Understanding of the mechanisms underlying these opposite changes in corticomotor excitability remains elusive. Modulation of primary sensory cortex (S1) excitability could underlie altered corticomotor excitability with PES. Here we examined whether changes in primary sensory (S1) and motor (M1) cortex excitability follow the same time-course when PES is applied using identical stimulus parameters. Corticomotor excitability was measured using transcranial magnetic stimulation (TMS) and sensory cortex excitability using somatosensory evoked potentials (SEPs) before and after 30 min of PES to right abductor pollicis brevis (APB). Two PES paradigms were tested in separate sessions; PES sufficient to induce a tetanic motor contraction (30–50 Hz; strong motor intensity) and PES at sub motor-threshold intensity (100 Hz). PES applied to induce strong activation of APB increased the size of the N20-P25 component, thought to reflect sensory processing at cortical level, and increased corticomotor excitability. PES at sensory intensity decreased the size of the P25-N33 component and reduced corticomotor excitability. A positive correlation was observed between the changes in amplitude of the cortical SEP components and corticomotor excitability following sensory and motor PES. Sensory PES also increased the sub-cortical P14-N20 SEP component. These findings provide evidence that PES results in co-modulation of S1 and M1 excitability, possibly due to cortico-cortical projections between S1 and M1. This mechanism may underpin changes in corticomotor excitability in response to afferent input generated by PES. PMID:23227260

  2. An examination of the effects of osmotic pressure changes upon transmitter release from mammalian motor nerve terminals.

    PubMed

    Hubbard, J I; Jones, S F; Landau, E M

    1968-08-01

    1. When the frequency of miniature end-plate potentials (m.e.p.p.s) was measured at neuromuscular junctions in rat diaphragm nerve preparations in vitro bathed in solutions having osmolarities between 200 and 700 m-osmoles/l. it was found that m.e.p.p. frequency was transiently increased by exposure to osmotic gradients exceeding 75 m-osmoles/l., and then declined, within 1 hr, to a steady level slightly higher than the control level of frequency. Smaller osmotic gradients caused a maintained increase in m.e.p.p. frequency. E.p.p. quantal content was initially increased and later profoundly decreased upon exposure of preparations to solutions with an osmotic pressure of 500 or 600 m-osmoles/l. but was unaffected by less hypertonic solutions.2. Variation of the Ca or Mg content of the bathing solutions did not alter these effects of osmotic pressure on the early transient increase in m.e.p.p. frequency or e.p.p. quantal content but affected the late steady increase in m.e.p.p. frequency.3. The value of the transient increase in m.e.p.p. frequency was exponentially related to the osmotic gradient in the range 0-300 m-osmoles/l. with a Q(10) of 1.95 (range 11-34 degrees C). Greater osmotic gradients did not further increase m.e.p.p. frequency. Variation of the ionic strength of the bathing medium did not influence osmotic effects upon frequency.4. The discrepancy between the effects of osmotic gradients upon spontaneous and nerve-impulse induced transmitter release was explained by an occlusion of the osmotic effects by depolarization of nerve terminals. Time-course studies showed that in the presence of 20 mM-KCl the m.e.p.p. frequency increase in response to an increase in osmotic pressure was small and was followed by a reduction in frequency to below control levels while osmotic pressure changes had no immediate effect upon m.e.p.p. frequency in solutions containing 30 mM-KCl.5. It was concluded that increased osmotic gradients could release transmitter by a

  3. Neurophysiological navigation in the trigeminal nerve: use of masticatory responses and facial motor responses evoked by electrical stimulationof the trigeminal rootlets for RF-thermorhizotomy guidance.

    PubMed

    Sindou, M P

    1999-01-01

    RF-thermorhizotomy of the trigeminal nerve is an effective and safe treatment of trigeminal neuralgia, provided lesioning of the sensory fibers is performed precisely. To control the accurate placement of the electrode tip, electrical stimulation testing, prior to thermal lesioning, is of prime importance. The clinical observation of direct masticatory responses (DMR) and facial evoked motor responses (EMR) produced by stimulation of the trigeminal rootlets (at 5 Hz) helps to place the electrode tip in the optimal location. The best location is the one where the threshold for eliciting DMR is high and the threshold for evoking facial EMR in the area corresponding to the trigger zone is low. EMR in orbicularis oculi indicates location in V1, levator labii EMR signifies V2 and orbicular oris EMR corresponds to V3.

  4. Studies on conversion of motor function in intercostal nerves crossing for complete brachial plexus injuries of root avulsion type.

    PubMed

    Takahashi, M

    1983-11-01

    The progress of the functional conversion in cases where the 3rd and 4th intercostal nerves were crossed to the musculocutaneous nerve to regain elbow flexion after a total avulsion type of brachial plexus injury was followed up by means of the electromyogram, goniogram and spirogram in 25 patients. The joint position sense was further studied. It was found that in the early stage of reinnervation, spontaneous activity which synchronized with respiration was found in the biceps brachii muscles, but this involuntary element disappeared gradually and followed this the volitional control and endurance improved and became quite satisfactory within several years. It was observed that skin sensation played an important role in judging joint position.

  5. [The time course of the evoked secretion of the mediator quanta in various regions of the frog motor nerve ending].

    PubMed

    Nikol'skiĭ, E E; Bukharaeva, E A; Samigullin, D V; Gaĭnulov, R Kh

    2000-09-01

    Apart from the fact that the gradient of the velocity of the AP propagation along the nerve terminal and the intensity of secretion do exist, the kinetics of a quanta transmitter release may also be revealed in different parts of the terminal. The velocity of the propagation and the minimum sympatric delay tend to diminish along with moving away from the myelinated part of axon, whereas the synchronicity of the quanta release rises. The distinctions in the time course of secretion in different parts of the terminal were amplified when the calcium ion concentration in the medium was enhanced. The observed peculiarities of the secretion kinetics in different regions of nerve ending seem to compensate for diminishing of the amplitude of multiquantal endplate current.

  6. Apparent block of K+ currents in mouse motor nerve terminals by tetrodotoxin, mu-conotoxin and reduced external sodium.

    PubMed Central

    Braga, M. F.; Anderson, A. J.; Harvey, A. L.; Rowan, E. G.

    1992-01-01

    1. In mouse triangularis sterni nerve-muscle preparations, reduced extracellular Na+ concentrations and low concentrations of the Na+ channel blocking toxins tetrodotoxin (TTX, 18-36 nM) and mu-conotoxin GIIIB (0.4-2.0 microM) selectively decreased the amplitude of the component of perineural waveforms associated with nerve terminal K+ currents, without affecting the main Na+ spike. 2. Intracellular recording of endplate potentials (e.p.ps) and miniature endplate potentials (m.e.p.ps) from triangularis sterni preparations revealed that TTX and mu-conotoxin GIIIB depressed the evoked quantal release of acetylcholine without significant effects on m.e.p.p. amplitude, frequency or time constant of decay. 3. The apparent block of K+ current by low concentrations of TTX and mu-conotoxin is probably not a direct effect on K+ channels but results from a decrease in the passive depolarization of nerve terminals following blockade of a small proportion of axonal Na+ channels. PMID:1324070

  7. Responses of single units in the inferior olive to stimulation of the limb nerves, peripheral skin receptors, cerebellum, caudate nucleus and motor cortex

    PubMed Central

    Sedgwick, E. M.; Williams, T. D.

    1967-01-01

    1. Extra- and intracellular responses of single units in the inferior olive following stimulation of the cerebellum, limb nerves, skin receptors, the caudate nucleus and cerebral cortex have been described. 2. Responses following cerebellar stimulation were assumed to be antidromic spikes when they occurred after a latency of less than 4 msec and followed stimulus frequencies greater than 220/sec. Other responses with longer latencies were thought to be transynaptic. Evidence for recurrent inhibition of the Renshaw type is given. 3. Following limb nerve stimulation two types of units have been observed; units responding after a short latency and to stimulation of one limb only and units responding with a long latency following stimulation of one or more of the limbs. 4. Units responding to stimulation of the limb nerve after a short latency could often be excited by hair movement and/or light touch on the pads. Other units were excited by pinching and others could not be excited by a physiological stimulus. The receptive field of these units was small and there was no evidence of fringe inhibition. 5. Most units observed represented the contralateral forelimb but there was a significant number of units representing the ipsilateral limbs. 6. The caudato-olivary pathway has been shown to be excitatory. Short latency limb units do not receive afferents from the caudate nucleus. 7. Afferents from the motor cortex excite units in the inferior olive. A remarkable correlation of latencies of responses from both the cerebral cortex and the limbs on to individual units has been described. 8. The results suggest a complex organization of neurones within the inferior olive. A possible plan of the organization of neurones is given and discussed. PMID:5340538

  8. Ocular findings in conjoined (Siamese) twins.

    PubMed

    Mansour, A M; Mansour, N; Rosenberg, H S

    1991-01-01

    Conjoined twinning is a rare form of congenital anomaly. The ocular findings in six sets of conjoined twins as well as those reported elsewhere include abnormal optic nerve decussation, pseudosynophthalmos, microphthalmia, abnormal eyelids, orbital encephalocele, occipital encephalocele, and eyelid coloboma. These findings are interpreted as due to deformations from appositional fusion-related factors or malformations from developmental factors.

  9. Ocular dispersion

    NASA Astrophysics Data System (ADS)

    Hammer, Daniel X.; Noojin, Gary D.; Thomas, Robert J.; Stolarski, David J.; Rockwell, Benjamin A.; Welch, Ashley J.

    1999-06-01

    Spectrally resolved white-light interferometry (SRWLI) was used to measure the wavelength dependence of refractive index (i.e., dispersion) for various ocular components. The accuracy of the technique was assessed by measurement of fused silica and water, the refractive indices of which have been measured at several different wavelengths. The dispersion of bovine and rabbit aqueous and vitreous humor was measured from 400 to 1100 nm. Also, the dispersion was measured from 400 to 700 nm for aqueous and vitreous humor extracted from goat and rhesus monkey eyes. For the humors, the dispersion did not deviate significantly from water. In an additional experiment, the dispersion of aqueous and vitreous humor that had aged up to a month was compared to freshly harvested material. No difference was found between the fresh and aged media. An unsuccessful attempt was also made to use the technique for dispersion measurement of bovine cornea and lens. Future refinement may allow measurement of the dispersion of cornea and lens across the entire visible and near-infrared wavelength band. The principles of white- light interferometry including image analysis, measurement accuracy, and limitations of the technique, are discussed. In addition, alternate techniques and previous measurements of ocular dispersion are reviewed.

  10. Nerve growth factor administration attenuates cognitive but not neurobehavioral motor dysfunction or hippocampal cell loss following fluid-percussion brain injury in rats.

    PubMed

    Sinson, G; Voddi, M; McIntosh, T K

    1995-11-01

    Lateral fluid-percussion brain injury in rats results in cognitive deficits, motor dysfunction, and selective hippocampal cell loss. Neurotrophic factors have been shown to have potential therapeutic applications in neurodegenerative diseases, and nerve growth factor (NGF) has been shown to be neuroprotective in models of excitotoxicity. This study evaluated the neuroprotective efficacy of intracerebral NGF infusion after traumatic brain injury. Male Sprague-Dawley rats received lateral fluid-percussion brain injury of moderate severity (2.1-2.3 atm). A miniosmotic pump was implanted 24 h after injury to infuse NGF (n = 34) or vehicle (n = 16) directly into the region of maximal cortical injury. Infusions of NGF continued until the animal was killed at 72 h, 1 week, or 2 weeks after injury. Animals were evaluated for cognitive dysfunction (Morris Water Maze) and regional neuronal cell loss (Nissl staining) at each of the three time points. Animals surviving for 1 or 2 weeks were also evaluated for neurobehavioral motor function. Although an improvement in memory scores was not observed at 72 h after injury, animals receiving NGF infusions showed significantly improved memory scores when tested at 1 or 2 weeks after injury compared with injured animals receiving vehicle infusions (p < 0.05). Motor scores and CA3 hippocampal cell loss were not significantly different in any group of NGF-treated animals when compared with controls. These data suggest that NGF administration, in the acute, posttraumatic period following fluid-percussion brain injury, may have potential in improving post-traumatic cognitive deficits.

  11. A role for complexes of survival of motor neurons (SMN) protein with gemins and profilin in neurite-like cytoplasmic extensions of cultured nerve cells

    SciTech Connect

    Sharma, Aarti; Lambrechts, Anja; Le thi Hao; Le, Thanh T.; Sewry, Caroline A.; Ampe, Christophe; Burghes, Arthur H.M.; Morris, Glenn E. . E-mail: glenn.morris@rjah.nhs.uk

    2005-09-10

    Spinal muscular atrophy (SMA) is caused by reduced levels of SMN (survival of motor neurons protein) and consequent loss of motor neurons. SMN is involved in snRNP transport and nuclear RNA splicing, but axonal transport of SMN has also been shown to occur in motor neurons. SMN also binds to the small actin-binding protein, profilin. We now show that SMN and profilin II co-localise in the cytoplasm of differentiating rat PC12 cells and in neurite-like extensions, especially at their growth cones. Many components of known SMN complexes were also found in these extensions, including gemin2 (SIP-1), gemin6, gemin7 and unrip (unr-interacting protein). Coilin p80 and Sm core protein immunoreactivity, however, were seen only in the nucleus. SMN is known to associate with {beta}-actin mRNA and specific hnRNPs in axons and in neurite extensions of cultured nerve cells, and SMN also stimulates neurite outgrowth in cultures. Our results are therefore consistent with SMN complexes, rather than SMN alone, being involved in the transport of actin mRNPs along the axon as in the transport of snRNPs into the nucleus by similar SMN complexes. Antisense knockdown of profilin I and II isoforms inhibited neurite outgrowth of PC12 cells and caused accumulation of SMN and its associated proteins in cytoplasmic aggregates. BIAcore studies demonstrated a high affinity interaction of SMN with profilin IIa, the isoform present in developing neurons. Pathogenic missense mutations in SMN, or deletion of exons 5 and 7, prevented this interaction. The interaction is functional in that SMN can modulate actin polymerisation in vitro by reducing the inhibitory effect of profilin IIa. This suggests that reduced SMN in SMA might cause axonal pathfinding defects by disturbing the normal regulation of microfilament growth by profilins.

  12. [Laterofacial malformations (maxillomandibular neurocristopathies) associated with anomalies of the brain stem and cranial nerves].

    PubMed

    Couly, G; Le Lievre-Ayer, C

    1983-01-01

    Neurological and cerebral computed tomography examinations were conducted in 25 infants and young children with uni- or bilateral maxillomandibular neurocristopathies (Goldenhar's, Franceschetti's first arch syndromes or transient forms). Taking all lesions into account, 18 children (82%) presented morphological and motor anomalies of the brain stem (mesencephalus, metencephalus) and its corresponding cranial nerves: four had morphological anomalies of the cerebellum and pons; four presented disorders of bulbopontine control (heart, lungs, deglutition); fifteen demonstrated sensory, sensorial, and motor deficiencies of the paired cranial nerves III, V, VI, VII, and VIII. The high frequency of ocular malformations in this series is emphasized: there were three cases of cryptophthalmia and one case of bilateral iris coloboma. These findings are in agreement with recent acquisitions in the field of cephalic developmental biology: the cephalic neural crest cells, after migration from the mesencephalorhombencephalic neural fold, contribute to the latero-facial and ocular organogenesis. The unity of origin of the face and brain provides an explanation for the predictive role of the former in case of malformations of the brain and its cranial nerves.

  13. Effect of prolonged inactivity on skeletal motor nerve terminals during aestivation in the burrowing frog, Cyclorana alboguttata.

    PubMed

    Hudson, Nicholas J; Lavidis, Nickolas A; Choy, Peng T; Franklin, Craig E

    2005-04-01

    This study examined the effect of prolonged inactivity, associated with aestivation, on neuromuscular transmission in the green-striped burrowing frog, Cyclorana alboguttata. We compared the structure and function of the neuromuscular junctions on the iliofibularis muscle from active C. alboguttata and from C. alboguttata that had been aestivating for 6 months. Despite the prolonged period of immobility, there was no significant difference in the shape of the terminals (primary, secondary or tertiary branches) or the length of primary terminal branches between aestivators and non-aestivators. Furthermore, there was no significant difference in the membrane potentials of muscle fibres or in miniature end plate potential (EPP) frequency and amplitude. However, there was a significant decrease in evoked transmitter release characterised by a 56% decrease in mean EPP amplitude, and a 29% increase in the failure rate of nerve terminal action potentials to evoke transmitter release. The impact of this suite of neuromuscular characteristics on the locomotor performance of emergent frogs is discussed.

  14. Infiltration of carbon-labelled monocytes into the dorsal motor nucleus following an intraneural injection of ricinus communis agglutinin-60 into the vagus nerve in rats.

    PubMed

    Ling, E A; Leong, S K

    1988-08-01

    A marked increase in the number of non-neuronal cells occurred in the neuropil of the ipsilateral dorsal motor nucleus (DMN) 6 days after an intraneural injection of Ricinus communis agglutinin-60 into the vagus nerve in the cervical region of rats. Other structural changes in the DMN were the hypertrophy and reduction in number of the neurons. In order to verify the origin of the non-neuronal cells, a single intravenous injection of carbon was administered into these rats 4 days before, simultaneously, or 4 days after, the injection of the RCA-60. Thus, in rats given carbon 4 days before the RCA-60 injection, none of the non-neuronal cells were labelled. A few labelled cells, however, were observed in rats given carbon and RCA-60 simultaneously. Labelled non-neuronal cells were most common in rats given carbon 4 days after the RCA-60 injection. They were located in the neuropil as well as in the walls of blood vessels. Some blood elements in the lumen of blood vessels in the DMN were also labelled by carbon. Histochemical study at the electron microscopical level showed that some of the non-neuronal cells present in the neuropil of DMN were stained positively for non-specific esterase. They were located in the perivascular region and in the neuropil far removed from the blood vessels. Occasional non-specific esterase-positive mononuclear cells were observed seemingly in their passage through the endothelium of blood vessels. It was concluded from this study that a small proportion of non-neuronal cells which appear in the DMN following a RCA-60 injection into the vagus nerve are derived from blood monocytes. The infiltration of these cells, which had been labelled by intravenous carbon injection, is probably elicited by the degenerating neurons destroyed by the retrograde transport of RCA-60.

  15. Ocular Histopathologic Features of Congenital Zika Syndrome.

    PubMed

    Fernandez, Maria P; Parra Saad, Edgar; Ospina Martinez, Martha; Corchuelo, Sheryl; Mercado Reyes, Marcela; Herrera, Maria Jose; Parra Saavedra, Miguel; Rico, Angelica; Fernandez, Angela M; Lee, Richard K; Ventura, Camila V; Berrocal, Audina M; Dubovy, Sander R

    2017-09-21

    Congenital Zika syndrome (CZS) is known to be associated with severe malformations in newborns. Although microcephaly is the hallmark of this disease, the ocular findings are important given the severe visual impairment that has been observed in these patients. Regardless of the increased number of CZS cases reported, to date, no studies have described the ocular histopathologic findings of this entity. To evaluate the presence of Zika virus (ZIKV) antigens and describe the associated ocular histopathologic features of 4 cases of CZS. In this observational case series performed from June 19, 2015, through April 30, 2017, ocular tissue samples from 4 deceased fetuses with a diagnosis of CZS from the National Institute of Health in Colombia were sent to the Florida Lions Ocular Pathology Laboratory for evaluation. The microscopic features of each specimen were described, and immunostaining was performed using a ZIKV NS2B protein antibody. Ocular tissue samples from the 4 deceased fetuses (2 female, 2 male) ranging from 21.5 to 29 weeks' gestation with a diagnosis of CZS were studied. The 4 eyes manifested with pupillary membranes, immature anterior chamber angles, loss of pigment and thinning of the retinal pigment epithelium, choroidal thinning, undifferentiated nuclear layers of the retina, and a perivascular inflammatory infiltrate within the choroid. The optic nerve, present in 2 of the eyes, demonstrated atrophy. Expression of ZIKV antigen was present in the iris in cases 1, 3, and 4; the neural retina and choroid in case 1; and in the optic nerve in case 4. Loss of retinal pigment epithelium, the presence of a thin choroid, a perivascular choroidal inflammatory infiltrate, and atrophic changes within the optic nerve were consistently present. These findings may be attributed to ZIKV infection and warrant further study.

  16. Firing patterns and functional roles of different classes of spinal afferents in rectal nerves during colonic migrating motor complexes in mouse colon.

    PubMed

    Zagorodnyuk, Vladimir P; Kyloh, Melinda; Brookes, Simon J; Nicholas, Sarah J; Spencer, Nick J

    2012-08-01

    The functional role of the different classes of visceral afferents that innervate the large intestine is poorly understood. Recent evidence suggests that low-threshold, wide-dynamic-range rectal afferents play an important role in the detection and transmission of visceral pain induced by noxious colorectal distension in mice. However, it is not clear which classes of spinal afferents are activated during naturally occurring colonic motor patterns or during intense contractions of the gut smooth muscle. We developed an in vitro colorectum preparation to test how the major classes of rectal afferents are activated during spontaneous colonic migrating motor complex (CMMC) or pharmacologically induced contraction. During CMMCs, circular muscle contractions increased firing in low-threshold, wide-dynamic-range muscular afferents and muscular-mucosal afferents, which generated a mean firing rate of 1.53 ± 0.23 Hz (n = 8) under isotonic conditions and 2.52 ± 0.36 Hz (n = 17) under isometric conditions. These low-threshold rectal afferents were reliably activated by low levels of circumferential stretch induced by increases in length (1-2 mm) or load (1-3 g). In a small proportion of cases (5 of 34 units), some low-threshold muscular and muscular-mucosal afferents decreased their firing rate during the peak of the CMMC contractions. High-threshold afferents were never activated during spontaneous CMMC contractions or tonic contractions induced by bethanechol (100 μM). High-threshold rectal afferents were only activated by intense levels of circumferential stretch (10-20 g). These results show that, in the rectal nerves of mice, low-threshold, wide-dynamic-range muscular and muscular-mucosal afferents are excited during contraction of the circular muscle that occurs during spontaneous CMMCs. No activation of high-threshold rectal afferents was detected during CMMCs or intense contractile activity in naïve mouse colorectum.

  17. Emerging ocular biomarkers of Alzheimer disease.

    PubMed

    van Wijngaarden, Peter; Hadoux, Xavier; Alwan, Mostafa; Keel, Stuart; Dirani, Mohamed

    2017-01-01

    Interest in reliable biomarkers of Alzheimer disease, the leading cause of dementia, has been fuelled by challenges in diagnosing the disease and monitoring disease progression as well as the response to therapy. A range of ocular manifestations of Alzheimer disease, including retinal and lens amyloid-beta accumulation, retinal nerve fiber layer loss, and retinal vascular changes, have been proposed as potential biomarkers of the disease. Herein, we examine the evidence regarding the potential value of these ocular biomarkers of Alzheimer disease. © 2016 Royal Australian and New Zealand College of Ophthalmologists.

  18. Hypertonic enhancement of transmitter release from frog motor nerve terminals: Ca2+ independence and role of integrins

    NASA Technical Reports Server (NTRS)

    Kashani, A. H.; Chen, B. M.; Grinnell, A. D.

    2001-01-01

    Hyperosmotic solutions cause markedly enhanced spontaneous quantal release of neurotransmitter from many nerve terminals. The mechanism of this enhancement is unknown. We have investigated this phenomenon at the frog neuromuscular junction with the aim of determining the degree to which it resembles the modulation of release by stretch, which has been shown to be mediated by mechanical tension on integrins.The hypertonicity enhancement, like the stretch effect, does not require Ca2+ influx or release from internal stores, although internal release may contribute to the effect. The hypertonicity effect is sharply reduced (but not eliminated) by peptides containing the RGD sequence, which compete with native ligands for integrin bonds.There is co-variance in the magnitude of the stretch and osmotic effects; that is, individual terminals exhibiting a large stretch effect also show strong enhancement by hypertonicity, and vice versa. The stretch and osmotic enhancements also can partially occlude each other.There remain some clear-cut differences between osmotic and stretch forms of modulation: the larger range of enhancement by hypertonic solutions, the relative lack of effect of osmolarity on evoked release, and the reported higher temperature sensitivity of osmotic enhancement. Nevertheless, our data strongly implicate integrins in a significant fraction of the osmotic enhancement, possibly acting via the same mechanism as stretch modulation.

  19. Central respiratory effects on motor nerve activities after organophosphate exposure in a working heart brainstem preparation of the rat.

    PubMed

    Klein-Rodewald, Tanja; Seeger, Thomas; Dutschmann, Mathias; Worek, Franz; Mörschel, Michael

    2011-09-25

    The impact of organophosphorus compound (OP) intoxication on the activity of central respiratory circuitry, causing acetylcholinesterase (AChE) inhibition and accumulation of acetylcholine in the respiratory brainstem circuits, is not understood. We investigated the central effect of the OP Crotylsarin (CRS) on respiratory network activity using the working heart brainstem preparation, which specifically allows for the analysis of central drug effects without changes in brainstem oxygenation possibly caused by drug effects on peripheral cardio-respiratory activity. Respiratory network activity was determined from phrenic and hypoglossal or vagal nerve activities (PNA, HNA, VNA). To investigate combined central and peripheral CRS effects hypo-perfusion was used mimicking additional peripheral cardiovascular collapse. Systemic CRS application induced a brief central apnea and complete AChE-inhibition in the brainstem. Subsequently, respiration was characterised by highly significant reduced PNA minute activity, while HNA showed expiratory related extra bursting indicative for activation of un-specified oro-pharyngeal behaviour. During hypo-perfusion CRS induced significantly prolonged apnoea. In all experiments respiratory activity fully recovered after 1h. We conclude that CRS mediated AChE inhibition causes only transient central breathing disturbance. Apparently intrinsic brainstem mechanisms can compensate for cholinergic over activation. Nevertheless, combination of hypo-perfusion and CRS exposure evoke the characteristic breathing arrests associated with OP poisoning.

  20. Acellular Nerve Allografts in Peripheral Nerve Regeneration: A Comparative Study

    PubMed Central

    Moore, Amy M.; MacEwan, Matthew; Santosa, Katherine B.; Chenard, Kristofer E.; Ray, Wilson Z.; Hunter, Daniel A.; Mackinnon, Susan E.; Johnson, Philip J.

    2011-01-01

    Background Processed nerve allografts offer a promising alternative to nerve autografts in the surgical management of peripheral nerve injuries where short deficits exist. Methods Three established models of acellular nerve allograft (cold-preserved, detergent-processed, and AxoGen® -processed nerve allografts) were compared to nerve isografts and silicone nerve guidance conduits in a 14 mm rat sciatic nerve defect. Results All acellular nerve grafts were superior to silicone nerve conduits in support of nerve regeneration. Detergent-processed allografts were similar to isografts at 6 weeks post-operatively, while AxoGen®-processed and cold-preserved allografts supported significantly fewer regenerating nerve fibers. Measurement of muscle force confirmed that detergent-processed allografts promoted isograft-equivalent levels of motor recovery 16 weeks post-operatively. All acellular allografts promoted greater amounts of motor recovery compared to silicone conduits. Conclusions These findings provide evidence that differential processing for removal of cellular constituents in preparing acellular nerve allografts affects recovery in vivo. PMID:21660979

  1. Ocular perfusion pressure and ocular blood flow in glaucoma

    PubMed Central

    Cherecheanu, A Popa; Garhofer, G; Schmidl, D; Werkmeister, R; Schmetterer, L

    2013-01-01

    Glaucoma is a progressive optic neuropathy of unknown origin. It has been hypothesized that a vascular component is involved in glaucoma pathophysiology. This hypothesis has gained support from studies showing that reduced ocular perfusion pressure is a risk factor for the disease. The exact nature of the involvement is, however, still a matter of debate. Based on recent evidence we propose a model including primary and secondary insults in glaucoma. The primary insult appears to happen at the optic nerve head. Increased intraocular pressure and ischemia at the post-laminar optic nerve head affects retinal ganglion cell axons. Modulating factors are the biomechanical properties of the tissues and cerebrospinal fluid pressure. After this primary insult retinal ganglion cells function at a reduced energy level and are sensitive to secondary insults. These secondary insults may happen if ocular perfusion pressure falls below the lower limit of autoregulation or if neurovascular coupling fails. Evidence for both faulty autoregulation and reduced hyperemic response to neuronal stimulation has been provided in glaucoma patients. The mechanisms appear to involve vascular endothelial dysfunction and impaired astrocyte-vessel signaling. A more detailed understanding of these pathways is required to direct neuroprotective strategies via the neurovascular pathway. PMID:23009741

  2. Phrenic nerve transfer to the musculocutaneous nerve for the repair of brachial plexus injury: electrophysiological characteristics

    PubMed Central

    Liu, Ying; Xu, Xun-cheng; Zou, Yi; Li, Su-rong; Zhang, Bin; Wang, Yue

    2015-01-01

    Phrenic nerve transfer is a major dynamic treatment used to repair brachial plexus root avulsion. We analyzed 72 relevant articles on phrenic nerve transfer to repair injured brachial plexus that were indexed by Science Citation Index. The keywords searched were brachial plexus injury, phrenic nerve, repair, surgery, protection, nerve transfer, and nerve graft. In addition, we performed neurophysiological analysis of the preoperative condition and prognosis of 10 patients undergoing ipsilateral phrenic nerve transfer to the musculocutaneous nerve in our hospital from 2008 to 201 3 and observed the electromyograms of the biceps brachii and motor conduction function of the musculocutaneous nerve. Clinically, approximately 28% of patients had brachial plexus injury combined with phrenic nerve injury, and injured phrenic nerve cannot be used as a nerve graft. After phrenic nerve transfer to the musculocutaneous nerve, the regenerated potentials first appeared at 3 months. Recovery of motor unit action potential occurred 6 months later and became more apparent at 12 months. The percent of patients recovering ‘excellent’ and ‘good’ muscle strength in the biceps brachii was 80% after 18 months. At 12 months after surgery, motor nerve conduction potential appeared in the musculocutaneous nerve in seven cases. These data suggest that preoperative evaluation of phrenic nerve function may help identify the most appropriate nerve graft in patients with an injured brachial plexus. The functional recovery of a transplanted nerve can be dynamically observed after the surgery. PMID:25883637

  3. Aldose reductase-deficient mice are protected from delayed motor nerve conduction velocity, increased c-Jun NH2-terminal kinase activation, depletion of reduced glutathione, increased superoxide accumulation, and DNA damage.

    PubMed

    Ho, Eric C M; Lam, Karen S L; Chen, Yuk Shan; Yip, Johnny C W; Arvindakshan, Meena; Yamagishi, Shin-Ichiro; Yagihashi, Soroku; Oates, Peter J; Ellery, Craig A; Chung, Stephen S M; Chung, Sookja K

    2006-07-01

    The exaggerated flux through polyol pathway during diabetes is thought to be a major cause of lesions in the peripheral nerves. Here, we used aldose reductase (AR)-deficient (AR(-/-)) and AR inhibitor (ARI)-treated mice to further understand the in vivo role of polyol pathway in the pathogenesis of diabetic neuropathy. Under normal conditions, there were no obvious differences in the innervation patterns between wild-type AR (AR(+/+)) and AR(-/-) mice. Under short-term diabetic conditions, AR(-/-) mice were protected from the reduction of motor and sensory nerve conduction velocities observed in diabetic AR(+/+) mice. Sorbitol levels in the sciatic nerves of diabetic AR(+/+) mice were increased significantly, whereas sorbitol levels in the diabetic AR(-/-) mice were significantly lower than those in diabetic AR(+/+) mice. In addition, signs of oxidative stress, such as increased activation of c-Jun NH(2)-terminal kinase (JNK), depletion of reduced glutathione, increase of superoxide formation, and DNA damage, observed in the sciatic nerves of diabetic AR(+/+) mice were not observed in the diabetic AR(-/-) mice, indicating that the diabetic AR(-/-) mice were protected from oxidative stress in the sciatic nerve. The diabetic AR(-/-) mice also excreted less 8-hydroxy-2'-deoxyguanosine in urine than diabetic AR(+/+) mice. The structural abnormalities observed in the sural nerve of diabetic AR(+/+) mice were less severe in the diabetic AR(-/-) mice, although it was only mildly protected by AR deficiency under short-term diabetic conditions. Signs of oxidative stress and functional and structural abnormalities were also inhibited by the ARI fidarestat in diabetic AR(+/+) nerves, similar to those in diabetic AR(-/-) mice. Taken together, increased polyol pathway flux through AR is a major contributing factor in the early signs of diabetic neuropathy, possibly through depletion of glutathione, increased superoxide accumulation, increased JNK activation, and DNA damage.

  4. Nerve conduction and electromyography studies.

    PubMed

    Kane, N M; Oware, A

    2012-07-01

    Nerve conduction studies (NCS) and electromyography (EMG), often shortened to 'EMGs', are a useful adjunct to clinical examination of the peripheral nervous system and striated skeletal muscle. NCS provide an efficient and rapid method of quantifying nerve conduction velocity (CV) and the amplitude of both sensory nerve action potentials (SNAPs) and compound motor action potentials (cMAPs). The CV reflects speed of propagation of action potentials, by saltatory conduction, along large myelinated axons in a peripheral nerve. The amplitude of SNAPs is in part determined by the number of axons in a sensory nerve, whilst amplitude of cMAPs reflects integrated function of the motor axons, neuromuscular junction and striated muscle. Repetitive nerve stimulation (RNS) can identify defects of neuromuscular junction (NMJ) transmission, pre- or post-synaptic. Needle EMG examination can detect myopathic changes in muscle and signs of denervation. Combinations of these procedures can establish if motor and/or sensory nerve cell bodies or peripheral nerves are damaged (e.g. motor neuronopathy, sensory ganglionopathy or neuropathy), and also indicate if the primary target is the axon or the myelin sheath (i.e. axonal or demyelinating neuropathies). The distribution of nerve damage can be determined as either generalised, multifocal (mononeuropathy multiplex) or focal. The latter often due to compression at the common entrapment sites (such as the carpal tunnel, Guyon's canal, cubital tunnel, radial groove, fibular head and tarsal tunnel, to name but a few of the reported hundred or so 'entrapment neuropathies').

  5. Ice test in diagnosis of ocular myasthenia.

    PubMed

    Quddus, M A; Rahman, H Z; Ali, Z M; Khan, O S; Aftabuddin, M

    2013-10-01

    This observational, non-control, non equivalent pretest and post test descriptive study was carried out at Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from June 2009 to December 2009 to compare the efficacy of ice test and repetitive nerve stimulation (RNS) in diagnosis of ocular myasthenia gravis. Ten patients with fluctuating ptosis (4 male and 6 female) who were suspected of having ocular myasthenia were included in the study. Male and female ratio in the study was 2:3. The mean age of the patients was 28.1 years. Positive response to pyridostigmine was taken as confirmation of ocular myasthenia. A piece of ice (2cm × 1cm) was placed over the upper eyelid for 2 minutes and the vertical eye lid fissure height was noted before and after the application of ice. Repetitive nerve stimulation was performed in the same subjects subsequently. Results of two tests were compared. Eight patients shows good (>2mm) elevation of eyelid with ice and three patients had abnormal RNS. In conclusion, ice test appears as more sensitive clinical test to detect ocular myasthenia than RNS test.

  6. A system for functional imaging of the ocular fundus

    NASA Astrophysics Data System (ADS)

    Bonaiuti, Matteo; Rovati, Luigi; Riva, Charles E.

    2007-02-01

    Neurovascular coupling in the optic nerve is the physiological mechanism that adjusts the blood perfusion in the microcirculation of the optic nerve to support the neural activity induced by vision. The resulting variations in blood flow and thus in neural tissue oxygenation induce changes in the optical properties of the tissues. These variations can be detected optically as reflectivity changes in the neural tissues, i.e. the retina and optic nerve disk. To achieve a better understanding of the mechanisms underlying the neurovascular coupling, our study is aimed at the evaluation of reflectance changes of the optic nerve induced by visual stimulation. For this purpose, an ocular fundus reflectometer has been developed.

  7. Tetanic depression is overcome by tonic adenosine A2A receptor facilitation of L-type Ca2+ influx into rat motor nerve terminals

    PubMed Central

    Oliveira, Laura; Timóteo, M Alexandrina; Correia-de-Sá, Paulo

    2004-01-01

    Motor nerve terminals possess multiple voltage-sensitive calcium channels operating acetylcholine (ACh) release. In this study, we investigated whether facilitation of neuromuscular transmission by adenosine generated during neuronal firing was operated by Ca2+ influx via ‘prevalent’ P-type or via the recruitment of ‘silent’ L-type channels. The release of [3H]ACh from rat phrenic nerve endings decreased upon increasing the stimulation frequency of the trains (750 pulses) from 5 Hz (83 ± 4 × 103 disintegrations per minute per gram (d.p.m. g−1); n = 11) to 50 Hz (30 ± 3 × 103 d.p.m. g−1; n = 5). The P-type Ca2+ channel blocker, ω-agatoxin IVA (100 nm) reduced (by 40 ± 10%; n = 6) the release of [3H]ACh evoked by 50-Hz trains, while nifedipine (1 μm, an L-type blocker) was inactive. Tetanic depression was overcome (88 ± 6 × 103 d.p.m. g−1; n = 12) by stimulating the phrenic nerve with 50-Hz bursts (five bursts of 150 pulses, 20 s interburst interval). In these conditions, ω-agatoxin IVA (100 nm) failed to affect transmitter release, but nifedipine (1 μm) decreased [3H]ACh release by 21 ± 7% (n = 4). Inactivation of endogenous adenosine with adenosine deaminase (ADA, 0.5 U ml−1) reduced (by 54 ± 8%, n = 5) the release of [3H]ACh evoked with 50-Hz bursts. This effect was opposite to the excitatory actions of adenosine (0.5 mm), S-(p-nitrobenzyl)-6-thioinosine (5 μm, an adenosine uptake blocker) and CGS 21680C (3 nm, a selective A2A receptor agonist); as the A1 receptor agonist R-N6-phenylisopropyl adenosine (R-PIA, 300 nm) failed to affect the release of [3H]ACh, the results indicate that adenosine generated during 50-Hz bursts exerts an A2A-receptor-mediated tonus. The effects of ADA (0.5 U ml−1) and CGS 21680C (3 nm) were prevented by nifedipine (1 μm). Blocking tonic A2A receptor activation, with ADA (0.5 U ml−1) or 3,7-dimethyl-1-propargyl xanthine (10 μm, an A2A antagonist), recovered ω-agatoxin IVA (100 nm) inhibition and