Translabyrinthine vestibular neurectomy and simultaneous cochlear implant for Ménière's disease.

PubMed

Canzi, Pietro; Manfrin, Marco; Perotti, Marco; Aprile, Federico; Quaglieri, Silvia; Rebecchi, Elisabetta; Locatelli, Giulia; Benazzo, Marco

2017-01-01

Surgical management of Ménière's disease (MD) is recommended in case of medical and intratympanic treatment failures. Translabyrinthine vestibular nerve section has been considered the gold standard for denervation procedures in order to control vertigo attacks, although at the cost of sacrificing residual hearing. To the best of our knowledge, no work has been published with regard to a group of patients submitted to translabyrinthine vestibular neurectomy and simultaneous cochlear implant for MD. The aim of the present study was to assess the effectiveness of translabyrinthine vestibular nerve section and simultaneous cochlear implant in a prospective study. All adult patients (over 18 years of age) with a diagnosis of intractable unilateral definite MD and useless residual hearing function were enrolled after medical and intratympanic treatment failures. Pre- and postoperative otoneurological evaluation concerned: frequency of vertigo attacks, head impulse test and caloric testing, pure tone average and speech perception audiometry in quiet conditions, tinnitus handicap inventory test, functional level scale and rate of vertigo control, dizziness handicap inventory test, and MD patient-oriented severity index. At least 6 months of follow-up were needed to be enrolled in the study. Four patients were included in the study. Translabyrinthine vestibular nerve section and simultaneous cochlear implant seemed to considerably improve the disabling effects of MD, achieving a good control of vestibular symptoms (mean pre/postoperative vertigo attacks per month: 16.5/0), resolving hearing loss (mean pre/postoperative pure tone average in the affected ear: 86.2/32.5 dB), improving the tinnitus (mean pre/postoperative tinnitus handicap inventory test: 77.2/6), and finally increasing the overall quality-of-life parameters. In our preliminary report, translabyrinthine vestibular nerve section and simultaneous cochlear implant showed encouraging results in order to definitively control both vestibular and cochlear symptoms during the same therapeutic procedure.

Correlation between caloric and ocular vestibular evoked myogenic potential test results.

PubMed

Huang, Chi-Hsuan; Wang, Shou-Jen; Young, Yi-Ho

2012-02-01

The ocular vestibular evoked myogenic potential (o-VEMP) test results correlate significantly with caloric test results for patients with acoustic neuroma (AN), but not for patients with Meniere's disease (MD), indicating that the o-VEMP test may replace the caloric test for evaluating the vestibular nerve from which the AN arises. Conversely, the caloric, o-VEMP, and cervical VEMP (c-VEMP) tests should be performed to map lesion sites in the vestibular labyrinth. This study performed caloric, o-VEMP, and c-VEMP tests on patients with central and peripheral vestibular disorders to investigate their relationships. In all, 66 patients comprising 16 with unilateral AN and 50 with unilateral definite MD were enrolled. All patients underwent caloric, o-VEMP, and c-VEMP tests. In the AN group, the caloric test identified canal paresis and caloric areflexia in 10 ears, while the o-VEMP and c-VEMP tests identified abnormal (absent or delayed) responses in 12 and 11 ears, respectively. A significant correlation existed between caloric and o-VEMP test results, but not between caloric and c-VEMP test results, or between o-VEMP and c-VEMP test results. For the MD group, abnormal caloric, o-VEMP, and c-VEMP test results were obtained for 24%, 44%, and 38% of hydropic ears, respectively. No correlation existed between any two test results.

Efferent-Mediated Responses in Vestibular Nerve Afferents of the Alert Macaque

PubMed Central

Sadeghi, Soroush G.; Goldberg, Jay M.; Minor, Lloyd B.; Cullen, Kathleen E.

2009-01-01

The peripheral vestibular organs have long been known to receive a bilateral efferent innervation from the brain stem. However, the functional role of the efferent vestibular system has remained elusive. In this study, we investigated efferent-mediated responses in vestibular afferents of alert behaving primates (macaque monkey). We found that efferent-mediated rotational responses could be obtained from vestibular nerve fibers innervating the semicircular canals after conventional afferent responses were nulled by placing the corresponding canal plane orthogonal to the plane of motion. Responses were type III, i.e., excitatory for rotational velocity trapezoids (peak velocity, 320°/s) in both directions of rotation, consistent with those previously reported in the decerebrate chinchilla. Responses consisted of both fast and slow components and were larger in irregular (∼10 spikes/s) than in regular afferents (∼2 spikes/s). Following unilateral labyrinthectomy (UL) on the side opposite the recording site, similar responses were obtained. To confirm the vestibular source of the efferent-mediated responses, the ipsilateral horizontal and posterior canals were plugged following the UL. Responses to high-velocity rotations were drastically reduced when the superior canal (SC), the only intact canal, was in its null position, compared with when the SC was pitched 50° upward from the null position. Our findings show that vestibular afferents in alert primates show efferent-mediated responses that are related to the discharge regularity of the afferent, are of vestibular origin, and can be the result of both afferent excitation and inhibition. PMID:19091917

Efferent-mediated responses in vestibular nerve afferents of the alert macaque.

PubMed

Sadeghi, Soroush G; Goldberg, Jay M; Minor, Lloyd B; Cullen, Kathleen E

2009-02-01

The peripheral vestibular organs have long been known to receive a bilateral efferent innervation from the brain stem. However, the functional role of the efferent vestibular system has remained elusive. In this study, we investigated efferent-mediated responses in vestibular afferents of alert behaving primates (macaque monkey). We found that efferent-mediated rotational responses could be obtained from vestibular nerve fibers innervating the semicircular canals after conventional afferent responses were nulled by placing the corresponding canal plane orthogonal to the plane of motion. Responses were type III, i.e., excitatory for rotational velocity trapezoids (peak velocity, 320 degrees/s) in both directions of rotation, consistent with those previously reported in the decerebrate chinchilla. Responses consisted of both fast and slow components and were larger in irregular (approximately 10 spikes/s) than in regular afferents (approximately 2 spikes/s). Following unilateral labyrinthectomy (UL) on the side opposite the recording site, similar responses were obtained. To confirm the vestibular source of the efferent-mediated responses, the ipsilateral horizontal and posterior canals were plugged following the UL. Responses to high-velocity rotations were drastically reduced when the superior canal (SC), the only intact canal, was in its null position, compared with when the SC was pitched 50 degrees upward from the null position. Our findings show that vestibular afferents in alert primates show efferent-mediated responses that are related to the discharge regularity of the afferent, are of vestibular origin, and can be the result of both afferent excitation and inhibition.

An uncommon presentation of an VIII nerve tumor.

PubMed

Swensson, Rubem Cruz; Swensson, Rogério Poli; Pizzini, Fabio Eduardo Caramante; Boldorini, Pedro Robson; Jorge Júnior, José Jarjura

2008-01-01

Vestibular Shwannomas are responsible for 80-90% of the cerebelar-pontine angle tumors and their incidence is of 0.8 to 20.5% of all tumors. Unilateral and progressive hearing loss is the most frequent and premature symptom, and tinnitus is the second most common complaint. Only 5% of the patients have normal audiograms. In this case the patient complained of ipsilateral facial numbness and weak blink, posterior pinna hypoesthesia (Hitzelberger +), tear reduction and positive Romberg test. He also had mouth twisting but no other involvement of other cranial nerves. Hearing acuity was normal.

Ramsay Hunt syndrome with unilateral polyneuropathy involving cranial nerves V, VII, VIII, and XII in a diabetic patient.

PubMed

Sun, Wei-Lian; Yan, Jian-Liang; Chen, Li-Li

2011-01-01

Ramsay Hunt syndrome is a rare complication of the varicella zoster virus, defined as a peripheral facial palsy that typically results from involvement of the facial and auditory nerves. Ramsay Hunt syndrome can be associated with cranial nerves V, VI, IX, and X but rarely with XII. We describe an atypical case of Ramsay Hunt syndrome with multiple cranial nerve involvement of nerves V, VII, VIII, and XII. Antiviral drugs, antibiotics, insulin, and traditional Chinese drugs were administered immediately after admission. After 3 months of combination therapy, the patient had recovered satisfactorily. Herpes zoster can cause severe infections in diabetic patients and should be treated as soon after detection as possible. Ramsay Hunt syndrome should be recognized as a polycranial neuritis characterized by damage to sensory and motor nerves. In addition to facial and vestibular nerve paralysis, Ramsay Hunt syndrome may also involve cranial nerves V and XII.

The Video Head Impulse Test to Assess the Efficacy of Vestibular Implants in Humans

PubMed Central

Guinand, Nils; Van de Berg, Raymond; Cavuscens, Samuel; Ranieri, Maurizio; Schneider, Erich; Lucieer, Floor; Kingma, Herman; Guyot, Jean-Philippe; Pérez Fornos, Angélica

2017-01-01

The purpose of this study was to evaluate whether it is possible to restore the high-frequency angular vestibulo-ocular reflex (aVOR) in patients suffering from a severe bilateral vestibulopathy (BV) and implanted with a vestibular implant prototype. Three patients (S1–3) participated in the study. They received a prototype vestibular implant with one to three electrode branches implanted in the proximity of the ampullary branches of the vestibular nerve. Five electrodes were available for electrical stimulation: one implanted in proximity of the left posterior ampullary nerve in S1, one in the left lateral and another one in the superior ampullary nerves in S2, and one in the right lateral and another one in the superior ampullary nerves in S3. The high-frequency aVOR was assessed using the video head impulse test (EyeSeeCam; EyeSeeTec, Munich, Germany), while motion-modulated electrical stimulation was delivered via one of the implanted vestibular electrodes at a time. aVOR gains were compared to control measurements obtained in the same patients when the device was not activated. In three out of the five tested electrodes the aVOR gain increased monotonically with increased stimulation strength when head impulses were delivered in the plane of the implanted canal. In these cases, gains ranging from 0.4 to values above 1 were measured. A “reversed” aVOR could also be generated when inversed stimulation paradigms were used. In most cases, the gain for excitatory head impulses was superior to that recorded for inhibitory head impulses, consistent with unilateral vestibular stimulation. Improvements of aVOR gain were generally accompanied by a concomitant decrease of corrective saccades, providing additional evidence of an effective aVOR. High inter-electrode and inter-subject variability were observed. These results, together with previous research, demonstrate that it is possible to restore the aVOR in a broad frequency range using motion-modulated electrical stimulation of the vestibular afferents. This provides additional encouraging evidence of the possibility of achieving a useful rehabilitation alternative for patients with BV in the near future. PMID:29184530

Cross-axis adaptation improves 3D vestibulo-ocular reflex alignment during chronic stimulation via a head-mounted multichannel vestibular prosthesis

PubMed Central

Dai, Chenkai; Fridman, Gene Y.; Chiang, Bryce; Davidovics, Natan; Melvin, Thuy-Anh; Cullen, Kathleen E.; Della Santina, Charles C.

2012-01-01

By sensing three-dimensional (3D) head rotation and electrically stimulating the three ampullary branches of a vestibular nerve to encode head angular velocity, a multichannel vestibular prosthesis (MVP) can restore vestibular sensation to individuals disabled by loss of vestibular hair cell function. However, current spread to afferent fibers innervating non-targeted canals and otolith endorgans can distort the vestibular nerve activation pattern, causing misalignment between the perceived and actual axis of head rotation. We hypothesized that over time, central neural mechanisms can adapt to correct this misalignment. To test this, we rendered five chinchillas vestibular-deficient via bilateral gentamicin treatment and unilaterally implanted them with a head mounted MVP. Comparison of 3D angular vestibulo-ocular reflex (aVOR) responses during 2 Hz, 50°/s peak horizontal sinusoidal head rotations in darkness on the first, third and seventh days of continual MVP use revealed that eye responses about the intended axis remained stable (at about 70% of the normal gain) while misalignment improved significantly by the end of one week of prosthetic stimulation. A comparable time course of improvement was also observed for head rotations about the other two semicircular canal axes and at every stimulus frequency examined (0.2–5 Hz). In addition, the extent of disconjugacy between the two eyes progressively improved during the same time window. These results indicate that the central nervous system rapidly adapts to multichannel prosthetic vestibular stimulation to markedly improve 3D aVOR alignment within the first week after activation. Similar adaptive improvements are likely to occur in other species, including humans. PMID:21374081

Vestibular efferent neurons project to the flocculus

NASA Technical Reports Server (NTRS)

Shinder, M. E.; Purcell, I. M.; Kaufman, G. D.; Perachio, A. A.

2001-01-01

A bilateral projection from the vestibular efferent neurons, located dorsal to the genu of the facial nerve, to the cerebellar flocculus and ventral paraflocculus was demonstrated. Efferent neurons were double-labeled by the unilateral injections of separate retrograde tracers into the labyrinth and into the floccular and ventral parafloccular lobules. Efferent neurons were found with double retrograde tracer labeling both ipsilateral and contralateral to the sites of injection. No double labeling was found when using a fluorescent tracer with non-fluorescent tracers such as horseradish peroxidase (HRP) or biotinylated dextran amine (BDA), but large percentages of efferent neurons were found to be double labeled when using two fluorescent substances including: fluorogold, microruby dextran amine, or rhodamine labeled latex beads. These data suggest a potential role for vestibular efferent neurons in modulating the dynamics of the vestibulo-ocular reflex (VOR) during normal and adaptive conditions.

Morphological studies of the vestibular nerve

NASA Technical Reports Server (NTRS)

Bergstroem, B.

1973-01-01

The anatomy of the intratemporal part of the vestibular nerve in man, and the possible age related degenerative changes in the nerve were studied. The form and structure of the vestibular ganglion was studied with the light microscope. A numerical analysis of the vestibular nerve, and caliber spectra of the myelinated fibers in the vestibular nerve branches were studied in individuals of varying ages. It was found that the peripheral endings of the vestibular nerve form a complicated pattern inside the vestibular sensory epithelia. A detailed description of the sensory cells and their surface organelles is included.

Hearing outcome after concurrent endolymphatic shunt and vestibular nerve section.

PubMed

Moody-Antonio, Stephanie; House, John W

2003-05-01

To determine if endolymphatic shunt surgery concurrent with vestibular nerve section improves hearing outcome compared with vestibular nerve section alone. Retrospective observational study with cross-sectional survey. Tertiary otologic private practice. Thirty-five patients who underwent vestibular nerve section and endolymphatic shunt surgery and 17 patients who had vestibular nerve section alone between 1985 and 2000. Chart review and correspondence for audiogram results and survey. Hearing at last follow-up. Hearing Handicap Inventory, Dizziness Handicap Inventory, Tinnitus Handicap Inventory, and SF-36. Eight patients in the vestibular nerve section and 15 in the vestibular nerve section and endolymphatic shunt surgery group had an audiogram at more than 16 months after surgery available for review. In the vestibular nerve section group, three patients had same hearing whereas five were worse. In the vestibular nerve section and endolymphatic shunt surgery group, 2 patients showed improvement, 2 were the same, and 11 were worse. There was no significant difference in the change from preoperative pure tone average or Word Discrimination Score to postoperative levels between the surgical groups. Eighteen patients had serviceable hearing preoperatively. Five of 8 in the vestibular nerve section and 4 of 10 in the vestibular nerve section and endolymphatic shunt surgery groups maintained serviceable hearing postoperatively. Of the 52 patients, 33 responded to the survey (63%). There were no significant differences between the groups for Dizziness Handicap Inventory, Hearing Handicap Inventory, Tinnitus Handicap Inventory, or SF-36, suggesting that patient-oriented outcomes are the same in both groups. Concurrent endolymphatic shunt surgery and vestibular nerve section does not improve hearing or tinnitus outcome over vestibular nerve section alone.

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

NASA Technical Reports Server (NTRS)

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

1995-01-01

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

Sporadic Schwannomatosis: A Systematic Review Following the 2005 Consensus Statement.

PubMed

Chick, Gregoire; Victor, Jan; Poujade, Thibault; Hollevoet, Nadine

2018-06-14

 To identify the frequency of reports of sporadic schwannomatosis, the types of patients affected, and the nerves affected.  We identified all case reports and case series that reported on patients with sporadic schwannomatosis according to established criteria.  The initial search yielded 1,597 studies, of which 15 were included. A total of 38 of 55 individuals met the inclusion criteria. The mean age of the patients was 48 years; 41% were male. Thirty-three patients had peripheral nerve tumors, and 17 had spinal tumors. Twelve had tumors in both locations. Tumor distribution was unilateral in 25 of 30 cases (83.3%) and segmental (limited to one limb or five or fewer contiguous segments of the spine) in 28 of 38 cases (73.7%).  This systematic review quantified the number of individuals who meet the criteria for sporadic schwannomatosis and better described this population to facilitate the classification of neurofibromatosis in regard to the 2005 consensus statement. Unilateral or segmental distribution of nerve tumors are key aspects when dealing with multiple noncutaneous schwannomas without involvement of the vestibular nerve. Georg Thieme Verlag KG Stuttgart · New York.

The effect of severity of unilateral vestibular dysfunction on symptoms, disabilities and handicap in vertiginous patients.

PubMed

Bamiou, D E; Davies, R A; McKee, M; Luxon, L M

1999-02-01

This study compares the symptoms, disabilities and handicap, as assessed by means of a questionnaire, in two groups of patients with a unilateral peripheral vestibular disorder: those with a total canal paresis and those with a partial canal paresis, as judged by the duration parameter using the Fitzgerald Hallpike caloric test in the absence of optic fixation. The results of the study indicate that the severity of dizziness, the Dizziness Index (severity x frequency) and the overall level of disabilities related to visual vertigo are less severe in unilateral profound or total loss of vestibular function than in unilateral mild vestibular loss.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on Intraoperative Cranial Nerve Monitoring in Vestibular Schwannoma Surgery.

PubMed

Vivas, Esther X; Carlson, Matthew L; Neff, Brian A; Shepard, Neil T; McCracken, D Jay; Sweeney, Alex D; Olson, Jeffrey J

2018-02-01

Does intraoperative facial nerve monitoring during vestibular schwannoma surgery lead to better long-term facial nerve function? This recommendation applies to adult patients undergoing vestibular schwannoma surgery regardless of tumor characteristics. Level 3: It is recommended that intraoperative facial nerve monitoring be routinely utilized during vestibular schwannoma surgery to improve long-term facial nerve function. Can intraoperative facial nerve monitoring be used to accurately predict favorable long-term facial nerve function after vestibular schwannoma surgery? This recommendation applies to adult patients undergoing vestibular schwannoma surgery. Level 3: Intraoperative facial nerve can be used to accurately predict favorable long-term facial nerve function after vestibular schwannoma surgery. Specifically, the presence of favorable testing reliably portends a good long-term facial nerve outcome. However, the absence of favorable testing in the setting of an anatomically intact facial nerve does not reliably predict poor long-term function and therefore cannot be used to direct decision-making regarding the need for early reinnervation procedures. Does an anatomically intact facial nerve with poor electromyogram (EMG) electrical responses during intraoperative testing reliably predict poor long-term facial nerve function? This recommendation applies to adult patients undergoing vestibular schwannoma surgery. Level 3: Poor intraoperative EMG electrical response of the facial nerve should not be used as a reliable predictor of poor long-term facial nerve function. Should intraoperative eighth cranial nerve monitoring be used during vestibular schwannoma surgery? This recommendation applies to adult patients undergoing vestibular schwannoma surgery with measurable preoperative hearing levels and tumors smaller than 1.5 cm. Level 3: Intraoperative eighth cranial nerve monitoring should be used during vestibular schwannoma surgery when hearing preservation is attempted. Is direct monitoring of the eighth cranial nerve superior to the use of far-field auditory brain stem responses? This recommendation applies to adult patients undergoing vestibular schwannoma surgery with measurable preoperative hearing levels and tumors smaller than 1.5 cm. Level 3: There is insufficient evidence to make a definitive recommendation.  The full guideline can be found at: https://www.cns.org/guidelines/guidelines-manage-ment-patients-vestibular-schwannoma/chapter_4. Copyright © 2017 by the Congress of Neurological Surgeons

Procedures for restoring vestibular disorders

PubMed Central

Walther, Leif Erik

2005-01-01

This paper will discuss therapeutic possibilities for disorders of the vestibular organs and the neurons involved, which confront ENT clinicians in everyday practice. Treatment of such disorders can be tackled either symptomatically or causally. The possible strategies for restoring the body's vestibular sense, visual function and co-ordination include medication, as well as physical and surgical procedures. Prophylactic or preventive measures are possible in some disorders which involve vertigo (bilateral vestibulopathy, kinetosis, height vertigo, vestibular disorders when diving (Tables 1 (Tab. 1) and 2 (Tab. 2)). Glucocorticoid and training therapy encourage the compensation of unilateral vestibular loss. In the case of a bilateral vestibular loss, it is important to treat the underlying disease (e.g. Cogan's disease). Although balance training does improve the patient's sense of balance, it will not restore it completely. In the case of Meniere's disease, there are a number of medications available to either treat bouts or to act as a prophylactic (e.g. dimenhydrinate or betahistine). In addition, there are non-ablative (sacculotomy) as well as ablative surgical procedures (e.g. labyrinthectomy, neurectomy of the vestibular nerve). In everyday practice, it has become common to proceed with low risk therapies initially. The physical treatment of mild postural vertigo can be carried out quickly and easily in outpatients (repositioning or liberatory maneuvers). In very rare cases it may be necessary to carry out a semicircular canal occlusion. Isolated disturbances of the otolith function or an involvement of the otolith can be found in roughly 50% of labyrinth disturbances. A specific surgical procedure to selectively block the otolith organs is currently being studied. When an external perilymph fistula involving loss of perilymph is suspected, an exploratory tympanotomy involving also the round and oval window niches must be carried out. A traumatic rupture of the round window membrane can, for example, also be caused by an implosive inner ear barotrauma during the decompression phase of diving. Dehiscence of the anterior semicircular canal, a relatively rare disorder, can be treated conservatively (avoiding stimuli which cause dizziness), by non-ablative „resurfacing" or by „plugging" the semicircular canal. A perilymph fistula can cause a Tullio-phenomenon resulting from a traumatic dislocation or hypermobility of the stapes, which can be surgically corrected. Vestibular disorders can also result from otosurgical therapy. When balance disorders persist following stapedectomy it is necessary to carry out a revision operation in order to either exclude a perilymph fistula or shorten the piston. Surgically reducing the size of open mastoid cavities (using for example porous hydroxylapatite or cartilage) can result in a reduction of vertiginous symptoms while nursing or during exposure to ambient air. Vestibular disturbances can occur both before and after vestibular nerve surgery (acoustic neuroma). Initially, good vestibular compensation can be expected after surgically removing the acoustic neuroma. An aberrant regeneration of nerve fibers of the vestibulocochlear nerve has been suggested as a cause for secondary worsening. Episodes of vertigo can be caused by an irritation of the vestibular nerve (vascular loop). Neurovascular decompression is generally regarded as the best surgical therapy. In the elderly, vestibular disturbances can severely limit quality of life and are often aggravated by multiple comorbidities. Antivertiginous drugs (e.g. dimenhydrinate) in combination with movement training can significantly reduce symptoms. Administering antivertiginous drugs over varying periods of time (e.g. transdermal scopolamine application via patches) as well as kinetosis training can be used as both prophylactically and as a therapy for kinetosis. Exposure training should be used as a prophylactic for height vertigo. PMID:22073053

Hyperventilation-induced nystagmus in vestibular schwannoma and unilateral sensorineural hearing loss.

PubMed

Mandalà, Marco; Giannuzzi, Annalisa; Astore, Serena; Trabalzini, Franco; Nuti, Daniele

2013-07-01

We evaluated the incidence and characteristics of hyperventilation-induced nystagmus (HVN) in 49 patients with gadolinium-enhanced magnetic resonance imaging evidence of vestibular schwannoma and 53 patients with idiopathic unilateral sensorineural hearing loss and normal radiological findings. The sensitivity and specificity of the hyperventilation test were compared with other audio-vestibular diagnostic tests (bedside examination of eye movements, caloric test, auditory brainstem responses) in the two groups of patients. The hyperventilation test scored the highest diagnostic efficiency (sensitivity 65.3 %; specificity 98.1 %) of the four tests in the differential diagnosis of vestibular schwannoma and idiopathic unilateral sensorineural hearing loss. Small tumors with a normal caloric response or caloric paresis were associated with ipsilateral HVN and larger tumors and severe caloric deficits with contralateral HVN. These results confirm that the hyperventilation test is a useful diagnostic test for predicting vestibular schwannoma in patients with unilateral sensorineural hearing loss.

Inner ear disorders.

PubMed

Smouha, Eric

2013-01-01

To present a framework for the diagnosis and treatment of inner ear disorders, with an emphasis on problems common to neuro-rehabilitation. Disorders of the inner ear can cause hearing loss, tinnitus, vertigo and imbalance. Hearing loss can be conductive, sensorineural, or mixed; conductive hearing loss arises from the ear canal or middle ear, while sensorineural hearing loss arises from the inner ear or auditory nerve. Vertigo is a hallucination of motion, and is the cardinal symptom of vestibular system disease. It should be differentiated from other causes of dizziness: gait imbalance, disequilibrium, lightheadedness (pre-syncope). Vertigo can be caused by problems in the inner ear or central nervous system. The diagnosis of inner ear disorders begins with a targeted physical examination. The initial work-up of hearing loss is made by audiometry, and vertigo by electronystagmography (ENG). Supplemental tests and MRI are obtained when clinically indicated. The clinical pattern and duration of vertigo are the most important clinical features in the diagnosis. Common inner ear causes of vertigo include: vestibular neuritis (sudden, unilateral vestibular loss), Meniere's disease (episodic vertigo), benign paroxysmal positional vertigo (BPPV), and bilateral vestibular loss. Common central nervous system causes of vertigo include: post concussion syndrome, cervical vertigo, vestibular migraine, cerebrovascular disease, and acoustic neuroma. A basic knowledge of vestibular physiology, coupled with a understanding of common vestibular syndromes, will lead to correct diagnosis and treatment in most cases.

Habilitation of facial nerve dysfunction after resection of a vestibular schwannoma.

PubMed

Rudman, Kelli L; Rhee, John S

2012-04-01

Facial nerve dysfunction after resection of a vestibular schwannoma is one of the most common indications for facial nerve habilitation. This article presents an overview of common and emerging management options for facial habilitation following resection of a vestibular schwannoma. Immediate and delayed nerve repair options, as well as adjunctive surgical, medical, and physical therapies for facial nerve dysfunction, are discussed. Two algorithms are provided as guides for the assessment and treatment of facial nerve paralysis after resection of vestibular schwannoma. Copyright © 2012 Elsevier Inc. All rights reserved.

Acute Unilateral Vestibular Failure Does Not Cause Spatial Hemineglect.

PubMed

Conrad, Julian; Habs, Maximilian; Brandt, Thomas; Dieterich, Marianne

2015-01-01

Visuo-spatial neglect and vestibular disorders have common clinical findings and involve the same cortical areas. We questioned (1) whether visuo-spatial hemineglect is not only a disorder of spatial attention but may also reflect a disorder of higher cortical vestibular function and (2) whether a vestibular tone imbalance due to an acute peripheral dysfunction can also cause symptoms of neglect or extinction. Therefore, patients with an acute unilateral peripheral vestibular failure (VF) were tested for symptoms of hemineglect. Twenty-eight patients with acute VF were assessed for signs of vestibular deficits and spatial neglect using clinical measures and various common standardized paper-pencil tests. Neglect severity was evaluated further with the Center of Cancellation method. Pathological neglect test scores were correlated with the degree of vestibular dysfunction determined by the subjective visual vertical and caloric testing. Three patients showed isolated pathological scores in one or the other neglect test, either ipsilesionally or contralesionally to the VF. None of the patients fulfilled the diagnostic criteria of spatial hemineglect or extinction. A vestibular tone imbalance due to unilateral failure of the vestibular endorgan does not cause spatial hemineglect, but evidence indicates it causes mild attentional deficits in both visual hemifields.

Acute Unilateral Vestibular Failure Does Not Cause Spatial Hemineglect

PubMed Central

Conrad, Julian; Habs, Maximilian; Brandt, Thomas; Dieterich, Marianne

2015-01-01

Objectives Visuo-spatial neglect and vestibular disorders have common clinical findings and involve the same cortical areas. We questioned (1) whether visuo-spatial hemineglect is not only a disorder of spatial attention but may also reflect a disorder of higher cortical vestibular function and (2) whether a vestibular tone imbalance due to an acute peripheral dysfunction can also cause symptoms of neglect or extinction. Therefore, patients with an acute unilateral peripheral vestibular failure (VF) were tested for symptoms of hemineglect. Methods Twenty-eight patients with acute VF were assessed for signs of vestibular deficits and spatial neglect using clinical measures and various common standardized paper-pencil tests. Neglect severity was evaluated further with the Center of Cancellation method. Pathological neglect test scores were correlated with the degree of vestibular dysfunction determined by the subjective visual vertical and caloric testing. Results Three patients showed isolated pathological scores in one or the other neglect test, either ipsilesionally or contralesionally to the VF. None of the patients fulfilled the diagnostic criteria of spatial hemineglect or extinction. Conclusions A vestibular tone imbalance due to unilateral failure of the vestibular endorgan does not cause spatial hemineglect, but evidence indicates it causes mild attentional deficits in both visual hemifields. PMID:26247469

Artifacts produced during electrical stimulation of the vestibular nerve in cats. [autonomic nervous system components of motion sickness

NASA Technical Reports Server (NTRS)

Tang, P. C.

1973-01-01

Evidence is presented to indicate that evoked potentials in the recurrent laryngeal, the cervical sympathetic, and the phrenic nerve, commonly reported as being elicited by vestibular nerve stimulation, may be due to stimulation of structures other than the vestibular nerve. Experiments carried out in decerebrated cats indicated that stimulation of the petrous bone and not that of the vestibular nerve is responsible for the genesis of evoked potentials in the recurrent laryngeal and the cervical sympathetic nerves. The phrenic response to electrical stimulation applied through bipolar straight electrodes appears to be the result of stimulation of the facial nerve in the facial canal by current spread along the petrous bone, since stimulation of the suspended facial nerve evoked potentials only in the phrenic nerve and not in the recurrent laryngeal nerve. These findings indicate that autonomic components of motion sickness represent the secondary reactions and not the primary responses to vestibular stimulation.

[Anatomicopathological relation between facial nerve and large vestibular Schwannoma].

PubMed

Jiang, T; Yu, C; Guo, E; Guan, S; Yan, C

2001-05-10

To study the anatomicopathological relation between facial nerve and large vestibular schwannoma. Operation by suboccipital retrosigmoid sinus approach was performed on 40 cases with large vestibular schwannoma, During the operation, the anatomicopathological relation between the facial nerve and the vestibular schwannoma was observed directly. The facial nerve was found to be located ventrally (deep under the tumor), dorsally (over the tumor), at the upper pole of the tumor (near the tentorium cerebelli), at the lower pole of the tumor (near the rear group cranial nerves), or aberrant (unable to be identified because of infiltration of tumor). In 31 cases, mainly with parenchymatous tumor, the facial nerve was flat in shape. In 9 cases, mainly with cystic tumor, the facial nerve was bandlike. The facial nerve varies greatly in neuroanatomy among patients with large vestibular schwannoma. Strengthening of operative monitoring can increase the safety of operation.

Reliability, Validity, and Sensitivity to Change of Turkish Activities-Specific Balance Confidence Scale in Patients with Unilateral Peripheral Vestibular Disease

ERIC Educational Resources Information Center

Karapolat, Hale; Eyigor, Sibel; Kirazli, Yesim; Celebisoy, Nese; Bilgen, Cem; Kirazli, Tayfun

2010-01-01

The aim of this study is to evaluate the internal consistency, test-retest reliability, construct validity, and sensitivity to change of the Activities-specific Balance Confidence Scale (ABC) in people with peripheral vestibular disorder. Thirty-three patients with unilateral peripheral vestibular disease were included in the study. Patients were…

Sequential [(18)F]FDG µPET whole-brain imaging of central vestibular compensation: a model of deafferentation-induced brain plasticity.

PubMed

Zwergal, Andreas; Schlichtiger, Julia; Xiong, Guoming; Beck, Roswitha; Günther, Lisa; Schniepp, Roman; Schöberl, Florian; Jahn, Klaus; Brandt, Thomas; Strupp, Michael; Bartenstein, Peter; Dieterich, Marianne; Dutia, Mayank B; la Fougère, Christian

2016-01-01

Unilateral inner ear damage is followed by a rapid behavioural recovery due to central vestibular compensation. In this study, we utilized serial [(18)F]Fluoro-deoxyglucose ([(18)F]FDG)-µPET imaging in the rat to visualize changes in brain glucose metabolism during behavioural recovery after surgical and chemical unilateral labyrinthectomy, to determine the extent and time-course of the involvement of different brain regions in vestibular compensation and test previously described hypotheses of underlying mechanisms. Systematic patterns of relative changes of glucose metabolism (rCGM) were observed during vestibular compensation. A significant asymmetry of rCGM appeared in the vestibular nuclei, vestibulocerebellum, thalamus, multisensory vestibular cortex, hippocampus and amygdala in the acute phase of vestibular imbalance (4 h). This was followed by early vestibular compensation over 1-2 days where rCGM re-balanced between the vestibular nuclei, thalami and temporoparietal cortices and bilateral rCGM increase appeared in the hippocampus and amygdala. Subsequently over 2-7 days, rCGM increased in the ipsilesional spinal trigeminal nucleus and later (7-9 days) rCGM increased in the vestibulocerebellum bilaterally and the hypothalamus and persisted in the hippocampus. These systematic dynamic rCGM patterns during vestibular compensation, were confirmed in a second rat model of chemical unilateral labyrinthectomy by serial [(18)F]FDG-µPET. These findings show that deafferentation-induced plasticity after unilateral labyrinthectomy involves early mechanisms of re-balancing predominantly in the brainstem vestibular nuclei but also in thalamo-cortical and limbic areas, and indicate the contribution of spinocerebellar sensory inputs and vestibulocerebellar adaptation at the later stages of behavioural recovery.

Asymmetric vestibular evoked myogenic potentials in unilateral Menière patients

PubMed Central

Wit, H. P.

2010-01-01

Vestibular evoked myogenic potentials (VEMPs) were measured in 22 unilateral Menière patients with monaural and binaural stimulation with 250 and 500 Hz tone bursts. For all measurement situations significantly lower VEMP amplitudes were on average measured at the affected side compared to the unaffected side. Unilateral Menière patients have, in contrast to normal subjects, asymmetric VEMPs, indicating a permanently affected vestibular (most likely otolith) system at the side of hearing loss. The diagnostic value of VEMP amplitude asymmetry measurement in individual patients is low, because of the large overlap of the VEMP amplitude asymmetry range for unilateral Menière patients with that for normal subjects. PMID:20665043

Auditory adaptation testing as a tool for investigating tinnitus origin: two patients with vestibular schwannoma.

PubMed

Silverman, Carol A; Silman, Shlomo; Emmer, Michele B

2017-06-01

To enhance the understanding of tinnitus origin by disseminating two case studies of vestibular schwannoma (VS) involving behavioural auditory adaptation testing (AAT). Retrospective case study. Two adults who presented with unilateral, non-pulsatile subjective tinnitus and bilateral normal-hearing sensitivity. At the initial evaluation, the otolaryngologic and audiologic findings were unremarkable, bilaterally. Upon retest, years later, VS was identified. At retest, the tinnitus disappeared in one patient and was slightly attenuated in the other patient. In the former, the results of AAT were positive for left retrocochlear pathology; in the latter, the results were negative for the left ear although a moderate degree of auditory adaptation was present despite bilateral normal-hearing sensitivity. Imaging revealed a small VS in both patients, confirmed surgically. Behavioural AAT in patients with tinnitus furnishes a useful tool for exploring tinnitus origin. Decrease or disappearance of tinnitus in patients with auditory adaptation suggests that the tinnitus generator is the cochlea or the cochlear nerve adjacent to the cochlea. Patients with unilateral tinnitus and bilateral, symmetric, normal-hearing thresholds, absent other audiovestibular symptoms, should be routinely monitored through otolaryngologic and audiologic re-evaluations. Tinnitus decrease or disappearance may constitute a red flag for retrocochlear pathology.

Symptoms, disability and handicap in unilateral peripheral vestibular disorders. Effects of early presentation and initiation of balance exercises.

PubMed

Bamiou, D E; Davies, R A; McKee, M; Luxon, L M

2000-01-01

The aim of this study was to obtain a profile of disability and handicap in patients with unilateral peripheral vestibular disorders presenting to a specialist tertiary care unit. Two validated questionnaires were sent to patients who had a unilateral peripheral vestibular disorder as defined by strict criteria. Some patients still suffered moderate handicap and disability 5 years after the initial symptoms related to a unilateral vestibular disorder, although the duration of symptoms (onset to questionnaire completion) did not correlate with severity of disability and handicap, as judged by questionnaire scores. However, patients presenting to the unit within 6 months of onset of vertigo commenced balance exercises significantly earlier and had significantly lower disability scores than patients presenting later. A high proportion of non-compliance with, and delay in initiation of, vestibular rehabilitation exercises was noted in the total patient sample, while compliance with, and early initiation of, Cooksey Cawthorne exercises were significantly correlated with low disability and questionnaire scores. These findings suggest that early referral to a specialist balance unit for patients with persistent dizziness is associated with better outcome.

Head-shaking nystagmus predicts greater disability in unilateral peripheral vestibulopathy.

PubMed

Angeli, Simon I; Velandia, Sandra; Snapp, Hillary

2011-01-01

The objective of this study was to determine the association of the bedside test of head-shaking nystagmus (HSN) with patients' self-perceived dizziness handicap as well as this test's sensitivity and specificity in unilateral peripheral vestibular hypofunction. A retrospective case-control study was performed. The study was held at an academic, tertiary referral center. Fifty-three adult patients with unilateral peripheral hypofunction defined by the caloric test of the videonystagmography with documented bedside HSN and who had completed questionnaires of self-perceived dizziness handicap were included. The sensitivity and specificity of the bedside HSN in patients and 10 healthy controls in diagnosing unilateral vestibular hypofunction defined by videonystagmographic caloric testing and by abnormal gain and symmetry of the vestibular-ocular reflex by rotary chair testing were determined. Scores of the screening test of the Dizziness Handicap Index and Functional Level Scale questionnaires were taken. When using the caloric irrigation test as the reference standard for unilateral vestibular hypofunction, the sensitivity, specificity, and positive predictive value of the bedside HSN were 31%, 96%, and 97%, respectively. When comparing with results of rotational chair testing (vestibular-ocular reflex gain and symmetry), the sensitivity of the HSN test increases to 71%. Patients with positive bedside HSN had higher scores (greater self-perceived dizziness handicap) of the Dizziness Handicap Index (P = .049) and higher (worse) scores of the Functional Level Scale (P = .0377) than those with negative bedside HSN (Wilcoxon rank test). Greater perceived handicap was correlated with a positive bedside HSN in patients with unilateral peripheral vestibulopathy. The HSN has sufficient sensitivity to be used as screening test of uncompensated vestibulopathy in this series. However, a negative HSN alone does not rule out the diagnosis of peripheral vestibular dysfunction. Copyright © 2011 Elsevier Inc. All rights reserved.

Patterning of sympathetic nerve activity in response to vestibular stimulation

NASA Technical Reports Server (NTRS)

Kerman, I. A.; McAllen, R. M.; Yates, B. J.

2000-01-01

Growing evidence suggests a role for the vestibular system in regulation of autonomic outflow during postural adjustments. In the present paper we review evidence for the patterning of sympathetic nerve activity elicited by vestibular stimulation. In response to electrical activation of vestibular afferents, firing of sympathetic nerves located throughout the body is altered. However, activity of the renal nerve is most sensitive to vestibular inputs. In contrast, high-intensity simultaneous activation of cutaneous and muscle inputs elicits equivalent changes in firing of the renal, superior mesenteric and lumbar colonic nerves. Responses of muscle vasoconstrictor (MVC) efferents to vestibular stimulation are either inhibitory (Type I) or are comprised of a combination of excitation and inhibition (Type II). Interestingly, single MVC units located in the hindlimb exhibited predominantly Type I responses while those located in the forelimb and face exhibited Type II responses. Furthermore, brachial and femoral arterial blood flows were dissociated in response to vestibular stimulation, such that brachial vascular resistance increased while femoral resistance decreased. These studies demonstrate that vestibulosympathetic reflexes are patterned according to both the anatomical location and innervation target of a particular sympathetic nerve, and can lead to distinct changes in local blood flow.

Vestibular schwannomas occur in schwannomatosis and should not be considered an exclusion criterion for clinical diagnosis.

PubMed

Smith, Miriam J; Kulkarni, Anjana; Rustad, Cecilie; Bowers, Naomi L; Wallace, Andrew J; Holder, Susan E; Heiberg, Arvid; Ramsden, Richard T; Evans, D Gareth

2012-01-01

Schwannomatosis is a recently delineated inherited condition that has clinical overlap with neurofibromatosis type 2 (NF2). Diagnostic criteria have been developed to distinguish schwannomatosis from NF2, but the existence of mosaic NF2, which may closely mimic schwannomatosis, makes even these criteria problematic. In particular, it is not clear why there is a relative sparing of the cranial nerves from schwannomas in schwannomatosis. We have identified two individuals with schwannomatosis and a unilateral vestibular schwannoma (VS), where a diagnosis of NF2 has been excluded. A third case with an identified SMARCB1 mutation was reported by two radiologists to have a VS, but this was later confirmed as a jugular schwannoma. These cases question whether the current exclusion of a VS from the clinical diagnosis of schwannomatosis is justified. Copyright © 2011 Wiley Periodicals, Inc.

Transtympanic gentamicin and fibrin tissue adhesive for treatment of unilateral Menière's disease: effects on vestibular function.

PubMed

Casani, Augusto; Nuti, Daniele; Franceschini, Stefano Sellari; Gaudini, Elisa; Dallan, Iacopo

2005-12-01

To determine the effects of transtympanic injections, with a mixture composed of gentamicin and fibrin tissue adhesive (FTA), on vestibular function of patients with intractable unilateral Menière's disease. This was an open, prospective study. The study was performed at 2 tertiary referral centers. Twenty-six patients affected by "definite" unilateral Menière's disease, unresponsive to medical therapy for at least 6 months, were enrolled. A buffered gentamicin solution mixed with FTA was injected in the middle ear until the development of bedside vestibular hypofunction signs and/or caloric weakness in the treated ear. Vestibular function was evaluated by 3 bedside vestibular tests (observation of spontaneous nystagmus, head shaking test, and head thrust test) and by a caloric test. Tests were performed on days 10 and 30 after completion of treatment. Tests were also performed 3, 6, and 12 months from completion of the gentamicin-FTA protocol. The effects of treatment were also assessed in terms of hearing levels, control of vertigo, and disability status. In 22 of the 26 patients, only 1 gentamicin-FTA injection was necessary to obtain 1 or more signs indicating a reduction of the vestibular function in the treated ear. Four patients needed another treatment because of the persistence of their incapacitating symptoms during the follow-up. Four patients needed more than 1 injection to obtain a vestibular hypofunction. None of the patients who received 1 or 2 injections presented hearing loss in direct temporal relationship to the treatment. A mixture of gentamicin and fibrin glue makes it possible to considerably reduce the number of administrations in patients with intractable unilateral Menière's disease. Spontaneous nystagmus, post head shaking nystagmus, and a head thrust sign are the clinical signs that indicate onset or progression of unilateral vestibular hypofunction. These signs were obtained with only 1 injection in 81% of patients.

Bilateral tympanokeratomas (cholesteatomas) with bilateral otitis media, unilateral otitis interna and acoustic neuritis in a dog.

PubMed

Østevik, Liv; Rudlang, Kathrine; Holt Jahr, Tuva; Valheim, Mette; Njaa, Bradley Lyndon

2018-05-22

An aural cholesteatoma, more appropriately named tympanokeratoma, is an epidermoid cyst of the middle ear described in several species, including dogs, humans and Mongolian gerbils. The cyst lining consists of stratified, keratinizing squamous epithelium with central accumulation of a keratin debris. This case report describes vestibular ganglioneuritis and perineuritis in a dog with chronic otitis, bilateral tympanokeratomas and presumed extension of otic infection to the central nervous system. An 11-year-old intact male Dalmatian dog with chronic bilateral otitis externa and sudden development of symptoms of vestibular disease was examined. Due to the dog's old age the owner opted for euthanasia without any further examination or treatment and the dog was submitted for necropsy. Transection of the ears revealed grey soft material in the external ear canals and pearly white, dry material consistent with keratin in the tympanic bullae bilaterally. The brain and meninges were grossly unremarkable. Microscopical findings included bilateral otitis externa and media, unilateral otitis interna, ganglioneuritis and perineuritis of the spiral ganglion of the vestibulocochlear nerve and multifocal to coalescing, purulent meningitis. A keratinizing squamous epithelial layer continuous with the external acoustic meatus lined the middle ear compartments, consistent with bilateral tympanokeratomas. Focal bony erosion of the petrous portion of the temporal bone and squamous epithelium and Gram-positive bacterial cocci were evident in the left cochlea. The findings suggest that meningitis developed secondary to erosion of the temporal bone and ganglioneuritis and/or perineuritis of the vestibulocochlear nerve. Middle ear tympanokeratoma is an important and potentially life-threatening otic condition in the dog. Once a tympanokeratoma has developed expansion of the cyst can lead to erosion of bone and extension of otic infection to the inner ear, vestibulocochlear ganglion and nerve potentially leading to bacterial infection of the central nervous system.

[Peripheral, central and functional vertigo syndromes].

PubMed

Strupp, M; Dieterich, M; Zwergal, A; Brandt, T

2015-12-01

Depending on the temporal course, three forms of vertigo syndrome can be differentiated: 1) vertigo attacks, e.g. benign paroxysmal positional vertigo (BPPV), Menière's disease and vestibular migraine, 2) acute spontaneous vertigo lasting for days, e.g. acute unilateral vestibulopathy, brainstem or cerebellar infarction and 3) symptoms lasting for months or years, e.g. bilateral vestibulopathy and functional vertigo. The specific therapy of the various syndromes is based on three principles: 1) physical treatment with liberatory maneuvers for BPPV and balance training for vestibular deficits, 2) pharmacotherapy, e.g. for acute unilateral vestibulopathy (corticosteroids) and Menière's disease (transtympanic administration of gentamicin or steroids and high-dose betahistine therapy); placebo-controlled pharmacotherapy studies are currently being carried out for acute unilateral vestibulopathy, vestibular paroxysmia, prophylaxis of BPPV, vestibular migraine, episodic ataxia type 2 and cerebellar ataxia; 3) psychotherapy for functional dizziness.

Compensation Following Bilateral Vestibular Damage

PubMed Central

McCall, Andrew A.; Yates, Bill J.

2011-01-01

Bilateral loss of vestibular inputs affects far fewer patients than unilateral inner ear damage, and thus has been understudied. In both animal subjects and human patients, bilateral vestibular hypofunction (BVH) produces a variety of clinical problems, including impaired balance control, inability to maintain stable blood pressure during postural changes, difficulty in visual targeting of images, and disturbances in spatial memory and navigational performance. Experiments in animals have shown that non-labyrinthine inputs to the vestibular nuclei are rapidly amplified following the onset of BVH, which may explain the recovery of postural stability and orthostatic tolerance that occurs within 10 days. However, the loss of the vestibulo-ocular reflex and degraded spatial cognition appear to be permanent in animals with BVH. Current concepts of the compensatory mechanisms in humans with BVH are largely inferential, as there is a lack of data from patients early in the disease process. Translation of animal studies of compensation for BVH into therapeutic strategies and subsequent application in the clinic is the most likely route to improve treatment. In addition to physical therapy, two types of prosthetic devices have been proposed to treat individuals with bilateral loss of vestibular inputs: those that provide tactile stimulation to indicate body position in space, and those that deliver electrical stimuli to branches of the vestibular nerve in accordance with head movements. The relative efficacy of these two treatment paradigms, and whether they can be combined to facilitate recovery, is yet to be ascertained. PMID:22207864

Modification of tenascin-R expression following unilateral labyrinthectomy in rats indicates its possible role in neural plasticity of the vestibular neural circuit.

PubMed

Gaal, Botond; Jóhannesson, Einar Örn; Dattani, Amit; Magyar, Agnes; Wéber, Ildikó; Matesz, Clara

2015-09-01

We have previously found that unilateral labyrinthectomy is accompanied by modification of hyaluronan and chondroitin sulfate proteoglycan staining in the lateral vestibular nucleus of rats and the time course of subsequent reorganization of extracellular matrix assembly correlates to the restoration of impaired vestibular function. The tenascin-R has repelling effect on pathfinding during axonal growth/regrowth, and thus inhibits neural circuit repair. By using immunohistochemical method, we studied the modification of tenascin-R expression in the superior, medial, lateral, and descending vestibular nuclei of the rat following unilateral labyrinthectomy. On postoperative day 1, tenascin-R reaction in the perineuronal nets disappeared on the side of labyrinthectomy in the superior, lateral, medial, and rostral part of the descending vestibular nuclei. On survival day 3, the staining intensity of tenascin-R reaction in perineuronal nets recovered on the operated side of the medial vestibular nucleus, whereas it was restored by the time of postoperative day 7 in the superior, lateral and rostral part of the descending vestibular nuclei. The staining intensity of tenascin-R reaction remained unchanged in the caudal part of the descending vestibular nucleus bilaterally. Regional differences in the modification of tenascin-R expression presented here may be associated with different roles of individual vestibular nuclei in the compensatory processes. The decreased expression of the tenascin-R may suggest the extracellular facilitation of plastic modifications in the vestibular neural circuit after lesion of the labyrinthine receptors.

Correlation between afferent rearrangements and behavioral deficits after local excitotoxic insult in the mammalian vestibule: a rat model of vertigo symptoms.

PubMed

Gaboyard-Niay, Sophie; Travo, Cécile; Saleur, Aurélie; Broussy, Audrey; Brugeaud, Aurore; Chabbert, Christian

2016-10-01

Damage to inner ear afferent terminals is believed to result in many auditory and vestibular dysfunctions. The sequence of afferent injuries and repair, as well as their correlation with vertigo symptoms, remains poorly documented. In particular, information on the changes that take place at the primary vestibular endings during the first hours following a selective insult is lacking. In the present study, we combined histological analysis with behavioral assessments of vestibular function in a rat model of unilateral vestibular excitotoxic insult. Excitotoxicity resulted in an immediate but transient alteration of the balance function that was resolved within a week. Concomitantly, vestibular primary afferents underwent a sequence of structural changes followed by spontaneous repair. Within the first two hours after the insult, a first phase of pronounced vestibular dysfunction coincided with extensive swelling of afferent terminals. In the next 24 h, a second phase of significant but incomplete reduction of the vestibular dysfunction was accompanied by a resorption of swollen terminals and fiber retraction. Eventually, within 1 week, a third phase of complete balance restoration occurred. The slow and progressive withdrawal of the balance dysfunction correlated with full reconstitution of nerve terminals. Competitive re-innervation by afferent and efferent terminals that mimicked developmental synaptogenesis resulted in full re-afferentation of the sensory epithelia. By deciphering the sequence of structural alterations that occur in the vestibule during selective excitotoxic impairment, this study offers new understanding of how a vestibular insult develops in the vestibule and how it governs the heterogeneity of vertigo symptoms. © 2016. Published by The Company of Biologists Ltd.

Concurrent Vision Dysfunctions in Convergence Insufficiency with Traumatic Brain Injury

PubMed Central

Alvarez, Tara L.; Kim, Eun H.; Vicci, Vincent R.; Dhar, Sunil K.; Biswal, Bharat B.; Barrett, A. M.

2012-01-01

Purpose This study assessed the prevalence of convergence insufficiency (CI) with and without simultaneous vision dysfunctions within the traumatic brain injury (TBI) sample population because although CI is commonly reported with TBI, the prevalence of concurrent visual dysfunctions with CI in TBI is unknown. Methods A retrospective analysis of 557 medical records from TBI civilian patients was conducted. Patients were all evaluated by a single optometrist. Visual acuity, oculomotor, binocular vision function, accommodation, visual fields, ocular health and vestibular function were assessed. Statistical comparisons between the CI and non-CI, as well as in-patient and out-patient subgroups, were conducted using chi-squared and Z-tests. Results Approximately 9% of the TBI sample had CI without the following simultaneous diagnoses: saccade or pursuit dysfunction; 3rd, 4th, or 6th nerve palsy; visual field deficit; visual spatial inattention/neglect; vestibular dysfunction or nystagmus. Photophobia with CI was observed in 16.3% (N=21/130) and vestibular dysfunction with CI was observed in 18.5% (N=24/130) of the CI subgroup. CI and cranial nerve palsies were common and yielded prevalence rates of 23.3% (N=130/557) and 26.9% (N=150/557), respectively, within the TBI sample. Accommodative dysfunction was common within the non-presbyopic TBI sample with a prevalence of 24.4% (N=76/314). Visual field deficits or unilateral visual spatial inattention/neglect were observed within 29.6% (N=80/270) of the TBI in-patient subgroup and were significantly more prevalent compared to the out-patient subgroup (p<0.001). Most TBI patients had visual acuities of 20/60 or better in the TBI sample (85%;N=473/557). Conclusions CI without simultaneous visual or vestibular dysfunctions was observed in about 9% of the visually symptomatic TBI civilian population studied. A thorough visual and vestibular examination is recommended for all TBI patients. PMID:23190716

Head-Shaking Nystagmus Depends on Gravity

PubMed Central

Marti, Sarah; Straumann, Dominik

2005-01-01

In acute unilateral peripheral vestibular deficit, horizontal spontaneous nystagmus (SN) increases when patients lie on their affected ear. This phenomenon indicates an ipsilesional reduction of otolith function that normally suppresses asymmetric semicircular canal signals. We asked whether head-shaking nystagmus (HSN) in patients with chronic unilateral vestibular deficit following vestibular neuritis is influenced by gravity in the same way as SN in acute patients. Using a three-dimensional (3-D) turntable, patients (N = 7) were placed in different whole-body positions along the roll plane and oscillated (1 Hz, ±10°) about their head-fixed vertical axis. Eye movements were recorded with 3-D magnetic search coils. HSN was modulated by gravity: When patients lay on their affected ear, slow-phase eye velocity significantly increased upon head shaking and consisted of a horizontal drift toward the affected ear (average: 1.2°/s ±0.5 SD), which was added to the gravity-independent and directionally nonspecific SN. In conclusion, HSN in patients with chronic unilateral peripheral vestibular deficit is best elicited when they are lying on their affected ear. This suggests a gravity-dependent mechanism similar to the one observed for SN in acute patients, i.e., an asymmetric suppression of vestibular nystagmus by the unilaterally impaired otolith organs. PMID:15735939

Surgical access to separate branches of the cat vestibular nerve

NASA Technical Reports Server (NTRS)

Radkevich, L. A.; Ayzikov, G. S.

1981-01-01

A posteroventral approach for access to separate branches of the cat vestibular nerve is presented which permits simultaneous surgical access to the ampullary and otolithic nerves. Surgical procedures are discussed.

A new vestibulo-ocular reflex recording system designed for routine vestibular clinical use.

PubMed

Funabiki, K; Naito, Y; Matsuda, K; Honjo, I

1999-01-01

A new vestibulo-ocular reflex (VOR) recording system was developed, which consists of an infrared eye camera, a small velocity sensor and a frequency modulator. Using this system, the head velocity signal was frequency modulated and simultaneously recorded as a sound signal on the audio track of a Hi8 video recorder with eye images. This device enabled recording of the VOR response in routine vestibular clinical practice. The reliability and effectiveness of this system were estimated by recording and analysing the VOR response against manually controlled rotation in normal subjects (n = 22) and in patients with unilateral severe vestibular hypofunction (n = 11). VOR gain on clockwise rotation viewed from the top was defined as R gain, and counterclockwise rotation as L gain. Directional preponderance (DP%) was also calculated. VOR gain towards the diseased side was significantly lower than that towards the intact side, and also significantly lower than that of normal subjects. DP% of unilateral vestibular hypofunction cases was significantly larger than that of normal subjects. These findings indicate that this VOR recording system reliably detects severe unilateral vestibular hypofunction.

Muscarinic acetylcholine receptor subtype expression in avian vestibular hair cells, nerve terminals and ganglion cells.

PubMed

Li, G Q; Kevetter, G A; Leonard, R B; Prusak, D J; Wood, T G; Correia, M J

2007-04-25

Muscarinic acetylcholine receptors (mAChRs) are widely expressed in the CNS and peripheral nervous system and play an important role in modulating the cell activity and function. We have shown that the cholinergic agonist carbachol reduces the pigeon's inwardly rectifying potassium channel (pKir2.1) ionic currents in native vestibular hair cells. We have cloned and sequenced pigeon mAChR subtypes M2-M5 and we have studied the expression of all five mAChR subtypes (M1-M5) in the pigeon vestibular end organs (semicircular canal ampullary cristae and utricular maculae), vestibular nerve fibers and the vestibular (Scarpa's) ganglion using tissue immunohistochemistry (IH), dissociated single cell immunocytochemistry (IC) and Western blotting (WB). We found that vestibular hair cells, nerve fibers and ganglion cells each expressed all five (M1-M5) mAChR subtypes. Two of the three odd-numbered mAChRs (M1, M5) were present on the hair cell cilia, supporting cells and nerve terminals. And all three odd numbered mAChRs (M1, M3 and M5) were expressed on cuticular plates, myelin sheaths and Schwann cells. Even-numbered mAChRs were seen on the nerve terminals. M2 was also shown on the cuticular plates and supporting cells. Vestibular efferent fibers and terminals were not identified in our studies. Results from WB of the dissociated vestibular epithelia, nerve fibers and vestibular ganglia were consistent with the results from IH and IC. Our findings suggest that there is considerable co-expression of the subtypes on the neural elements of the labyrinth. Further electrophysiological and pharmacological studies should delineate the mechanisms of action of muscarinic acetylcholine receptors on structures in the labyrinth.

The lesion site of vestibular dysfunction in Ramsay Hunt syndrome: a study by click and galvanic VEMP.

PubMed

Ozeki, Hidenori; Iwasaki, Shinichi; Ushio, Munetaka; Takeuchi, Naonobu; Murofushi, Toshihisa

2006-01-01

Ramsay Hunt syndrome (RHS) is characterized by vestibulocochlear dysfunction in addition to facial paralysis and auricular vesicles. The present study investigated the lesion site of vestibular dysfunction in a group of 10 RHS patients. Caloric testing, vestibular evoked myogenic potentials by click sound (cVEMP) and by galvanic stimulation (gVEMP) were used to assess the function of the lateral semicircular canal, saccule, and their afferents. The results of caloric testing (all 10 cases showed canal paresis) mean the existence of lesion sites in lateral semicircular canal and/or superior vestibular nerve (SVN). Abnormal cVEMPs in 7 patients mean the existence of lesions in saccule and/or inferior vestibular nerve (IVN). Four of the 6 patients with absent cVEMP also underwent gVEMP. The results of gVEMP (2 absent and 2 normal) mean that the former 2 have lesions of the vestibular nerve, and the latter 2 have only saccular lesions concerning the pathway of VEMPs. Thus, our study suggested that lesion sites of vestibular symptoms in RHS could be in the vestibular nerve and/or labyrinth, and in SVN and/or IVN. In other words, in the light of vestibular symptoms, there is the diversity of lesion sites.

Electric Current Transmission Through Tissues of the Vestibular Labyrinth of a Patient: Perfection of the Vestibular Implant

NASA Astrophysics Data System (ADS)

Demkin, V. P.; Shchetinin, P. P.; Melnichuk, S. V.; Kingma, H.; Van de Berg, R.; Pleshkov, M. O.; Starkov, D. N.

2018-03-01

An electric model of current transmission through tissues of the vestibular labyrinth of a patient is suggested. To stimulate directly the vestibular nerve in surgical operation, terminations of the electrodes are implanted through the bone tissue of the labyrinth into the perilymph in the vicinity of the vestibular nerve. The biological tissue of the vestibular labyrinth surrounding the electrodes and having heterogeneous composition possesses conductive and dielectric properties. Thus, when a current pulse from the vestibular implant is applied to one of the electrodes, conductive disturbance currents may arise between the electrodes and the vestibular nerves that can significantly deteriorate the direct signal quality. To study such signals and to compensate for the conductive disturbance currents, an equivalent electric circuit with actual electric impedance properties of tissues of the vestibular system is suggested, and the time parameters of the conductive disturbance current transmission are calculated. It is demonstrated that these parameters can reach large values. The suggested electric model and the results of calculations can be used for perfection of the vestibular implant.

Examination and treatment of patients with unilateral vestibular damage, with focus on the musculoskeletal system: a case series.

PubMed

Wilhelmsen, Kjersti; Kvåle, Alice

2014-07-01

Persistent dizziness and balance problems have been reported in some patients with unilateral vestibular pathology. The purpose of this case series was to address the examination and treatment of musculoskeletal dysfunction in patients with unilateral vestibular hypofunction. The musculoskeletal system was evaluated with the Global Physiotherapy Examination, dynamic balance was measured during walking with triaxial accelerometers positioned on the lower and upper trunk, and symptoms and functional limitations were assessed with standardized self-report measures. The 4 included patients had symptoms of severe dizziness that had lasted more than 1 year after the onset of vestibular dysfunction and a moderate level of perceived disability. Musculoskeletal abnormalities typically included postural misalignment, restricted abdominal respiration, restricted trunk movements, and tense muscles of the upper trunk and neck. The patients attended a modified vestibular rehabilitation program consisting of body awareness exercises addressing posture, movements, and respiration. After the intervention, self-reported symptoms and perceived disability improved. Improvements in mobility and positive physical changes were found in the upper trunk and respiratory movements. The attenuation of mediolateral accelerations (ie, body oscillations) in the upper trunk changed; a relatively more stable upper trunk and a concomitantly more flexible lower trunk were identified during walking in 3 patients. The recovery process may be influenced by self-inflicted rigid body movements and behavior strategies that prevent compensation. Addressing physical dysfunction and enhancing body awareness directly and dizziness indirectly may help patients with unilateral vestibular hypofunction break a self-sustaining cycle of dizziness and musculoskeletal problems. Considering the body as a functional unit and including both musculoskeletal and vestibular systems in examination and treatment may be important. © 2014 American Physical Therapy Association.

Vestibular Rehabilitation for Peripheral Vestibular Hypofunction: An Evidence-Based Clinical Practice Guideline

PubMed Central

Herdman, Susan J.; Whitney, Susan L.; Cass, Stephen P.; Clendaniel, Richard A.; Fife, Terry D.; Furman, Joseph M.; Getchius, Thomas S. D.; Goebel, Joel A.; Shepard, Neil T.; Woodhouse, Sheelah N.

2016-01-01

Background: Uncompensated vestibular hypofunction results in postural instability, visual blurring with head movement, and subjective complaints of dizziness and/or imbalance. We sought to answer the question, “Is vestibular exercise effective at enhancing recovery of function in people with peripheral (unilateral or bilateral) vestibular hypofunction?” Methods: A systematic review of the literature was performed in 5 databases published after 1985 and 5 additional sources for relevant publications were searched. Article types included meta-analyses, systematic reviews, randomized controlled trials, cohort studies, case control series, and case series for human subjects, published in English. One hundred thirty-five articles were identified as relevant to this clinical practice guideline. Results/Discussion: Based on strong evidence and a preponderance of benefit over harm, clinicians should offer vestibular rehabilitation to persons with unilateral and bilateral vestibular hypofunction with impairments and functional limitations related to the vestibular deficit. Based on strong evidence and a preponderance of harm over benefit, clinicians should not include voluntary saccadic or smooth-pursuit eye movements in isolation (ie, without head movement) as specific exercises for gaze stability. Based on moderate evidence, clinicians may offer specific exercise techniques to target identified impairments or functional limitations. Based on moderate evidence and in consideration of patient preference, clinicians may provide supervised vestibular rehabilitation. Based on expert opinion extrapolated from the evidence, clinicians may prescribe a minimum of 3 times per day for the performance of gaze stability exercises as 1 component of a home exercise program. Based on expert opinion extrapolated from the evidence (range of supervised visits: 2-38 weeks, mean = 10 weeks), clinicians may consider providing adequate supervised vestibular rehabilitation sessions for the patient to understand the goals of the program and how to manage and progress themselves independently. As a general guide, persons without significant comorbidities that affect mobility and with acute or subacute unilateral vestibular hypofunction may need once a week supervised sessions for 2 to 3 weeks; persons with chronic unilateral vestibular hypofunction may need once a week sessions for 4 to 6 weeks; and persons with bilateral vestibular hypofunction may need once a week sessions for 8 to 12 weeks. In addition to supervised sessions, patients are provided a daily home exercise program. Disclaimer: These recommendations are intended as a guide for physical therapists and clinicians to optimize rehabilitation outcomes for persons with peripheral vestibular hypofunction undergoing vestibular rehabilitation. Video Abstract available for more insights from the author (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A124). PMID:26913496

Vestibular short latency responses to pulsed linear acceleration in unanesthetized animals

NASA Technical Reports Server (NTRS)

Jones, T. A.

1992-01-01

Linear acceleration transients were used to elicit vestibular compound action potentials in non-invasively prepared, unanesthetized animals for the first time (chicks, Gallus domesticus, n = 33). Responses were composed of a series of up to 8 dominant peaks occurring within 8 msec of the stimulus. Response amplitudes for 1.0 g stimulus ranged from 1 to 10 microV. A late, slow, triphasic, anesthesia-labile component was identified as a dominant response feature in unanesthetized animals. Amplitudes increased and latencies decreased as stimulus intensity was increased (MANOVA P less than 0.05). Linear regression slope ranges were: amplitudes = 1.0-5.0 microV/g; latencies = -300 to -1100 microseconds/g. Thresholds for single polarity stimuli (0.035 +/- 0.022 g, n = 11) were significantly lower than those of alternating polarity (0.074 +/- 0.028 g, n = 18, P less than 0.001). Bilateral labyrinthectomy eliminated responses whereas bilateral extirpation of cochleae did not significantly change response thresholds. Intense acoustic masking (100/104 dB SL) produced no effect in 2 animals, but did produce small to moderate effects on response amplitudes in 7 others. Changes were attributed to effects on vestibular end organs. Results of unilateral labyrinth blockade (tetrodotoxin) suggest that P1 and N1 preferentially reflect ipsilateral eighth nerve compound action potentials whereas components beyond approximately 2 msec reflect activity from vestibular neurons that depend on both labyrinths. The results demonstrate that short latency vestibular compound action potentials can be measured in unanesthetized, non-invasively prepared animals.

Predictors of vertigo in patients with untreated vestibular schwannoma.

PubMed

Andersen, Jan Fredrik; Nilsen, Kathrin Skorpa; Vassbotn, Flemming Slinning; Møller, Per; Myrseth, Erling; Lund-Johansen, Morten; Goplen, Frederik Kragerud

2015-04-01

Previous studies have shown that vertigo is the most powerful negative predictor of quality of life in patients with vestibular schwannomas, but the variability in vertigo symptom severity is still poorly understood. We wanted to find out whether vertigo could be related to objective parameters such as tumor size, location, vestibular nerve function, hearing, and postural stability in patients with untreated vestibular schwannomas. Baseline data from prospective cohort study. Tertiary referral center. Four hundred thirty-four consecutive patients with unilateral VS diagnosed on MRI. Mean age 56 years (range 16-84 yr). Fifty-three percent women. Diagnostic, with a medical history, otolaryngological examination, pure-tone and speech audiometry, MRI, posturography, and videonystagmography with bithermal caloric tests. Dizziness measured on a 100-mm visual analog scale (VAS). Secondary outcome measures were canal paresis and postural imbalance (static and dynamic posturography). Three hundred three patients (70%) completed the VAS. Severe dizziness, defined as VAS 75 or greater, was reported by 9% of the patients. Larger tumors were associated with higher risk of postural instability and canal paresis. Moderate to severe dizziness was associated with postural imbalance and canal paresis, and possibly with small to medium-sized tumors. Postural instability was related to tumor size and canal paresis when measured by dynamic, but not with static, posturography. A minority of VS patients experience severe vestibular symptoms related to canal paresis and postural instability. A curvilinear relationship is hypothesized between tumor size and dizziness.

Three-dimensional head-mounted gaming task procedure maximizes effects of vestibular rehabilitation in unilateral vestibular hypofunction: a randomized controlled pilot trial.

PubMed

Micarelli, Alessandro; Viziano, Andrea; Augimeri, Ivan; Micarelli, Domenico; Alessandrini, Marco

2017-12-01

Considering the emerging advantages related to virtual reality implementation in clinical rehabilitation, the aim of the present study was to discover possible (i) improvements achievable in unilateral vestibular hypofunction patients using a self-assessed head-mounted device (HMD)-based gaming procedure when combined with a classical vestibular rehabilitation protocol (HMD group) as compared with a group undergoing only vestibular rehabilitation and (ii) HMD procedure-related side effects. Therefore, 24 vestibular rehabilitation and 23-matched HMD unilateral vestibular hypofunction individuals simultaneously underwent a 4-week rehabilitation protocol. Both otoneurological measures (vestibulo-ocular reflex gain and postural arrangement by studying both posturography parameters and spectral values of body oscillation) and performance and self-report measures (Italian Dizziness Handicap Inventory; Activities-specific Balance Confidence scale; Zung Instrument for Anxiety Disorders, Dynamic Gait Index; and Simulator Sickness Questionnaire) were analyzed by means of a between-group/within-subject analysis of variance model. A significant post-treatment between-effect was found, and the HMD group demonstrated an overall improvement in vestibulo-ocular reflex gain on the lesional side, in posturography parameters, in low-frequency spectral domain, as well as in Italian Dizziness Handicap Inventory and Activities-specific Balance Confidence scale scores. Meanwhile, Simulator Sickness Questionnaire scores demonstrated a significant reduction in symptoms related to experimental home-based gaming tasks during the HMD procedure. Our findings revealed the possible advantages of HMD implementation in vestibular rehabilitation, suggesting it as an innovative, self-assessed, low-cost, and compliant tool useful in maximizing vestibular rehabilitation outcomes.

Cold shivering activity after unilateral destruction of the vestibular apparatus

NASA Technical Reports Server (NTRS)

Kuzmina, G. I.

1980-01-01

The bioelectric activity of muscles (flexors and extensors of the forelimbs and hindlimbs) during cold shivering after unilateral destruction of the vestibular apparatus. It was found, that unilateral delabyrinthing produces bilateral facilitation of cold shivering in the flexor extremities more pronounced on the ipsilateral side. In the extensor muscles there was an absence of bioelectric activity both before and after delabyrinthing. Enhancement of cold shivering in the flexor extremities following intervention was evidently conditioned by removal of the inhibiting effect of the vestibulary apparatus on the function of special centers.

Video Head Impulse Test to Preoperatively Identify the Nerve of Origin of Vestibular Schwannomas.

PubMed

Constanzo, Felipe; Sens, Patricia; Teixeira, Bernardo Corrêa de Almeida; Ramina, Ricardo

2018-05-10

Identification of the nerve of origin in vestibular schwannoma (VS) is an important prognostic factor for hearing preservation surgery. Thus far, vestibular functional tests and magnetic resonance imaging have not yielded reliable results to preoperatively evaluate this information. The development of the video head impulse test (vHIT) has allowed a precise evaluation of each semicircular canal, and its localizing value has been tested for some peripheral vestibular diseases, but not for VS. To correlate patterns of semicircular canal alteration on vHIT to intraoperative identification of the nerve of origin of VSs. A total 31 patients with sporadic VSs were preoperatively evaluated with vHIT (gain of vestibule-ocular reflex, overt and covert saccades on each semicircular canal) and then the nerve of origin was surgically identified during surgical resection via retrosigmoid approach. vHIT results were classified as normal, isolated superior vestibular nerve (SVN) pattern, isolated inferior vestibular nerve (IVN) pattern, predominant SVN pattern, and predominant IVN pattern. Hannover classification, cystic component, and distance between the tumor and the end of the internal auditory canal were also considered for analysis. Three patients had a normal vHIT, 12 had an isolated SVN pattern, 5 had an isolated IVN pattern, 7 had a predominant SVN pattern, and 4 had a predominant IVN pattern. vHIT was able to correctly identify the nerve of origin in 89.7% of cases (100% of altered exams). The pattern of semicircular canal dysfunction on vHIT has a localizing value to identify the nerve of origin in VSs.

Ultrastructural and cytochemical evidence for single impulse initiation zones in vestibular macular nerve fibers of rat

NASA Technical Reports Server (NTRS)

Ross, Muriel D.; Chee, Oliver; Black, Samuel; Cutler, Lynn

1991-01-01

Cupric ion-ferricyanide labeling methods and related ferrocyanide-stained tissues were used to locate the characterize, at the ultrastructural level, presumptive impulse initiation zones in the three types of vestibular macular nerve fibers. Large-diameter, M-type vestibular nerve fibers terminate in a calyx at the heminode, and labeling is coextensive with the base of the calyx. Intermediate, M/U-type nerve fibers have short, unmyelinated preterminal segments that sometimes bifurcate intamacularly, and small-diameter, U-type nerve fibers have long, unmyelinated preterminal axons and up to three branches. Preterminals of these nerve fibers display ultrastructural heterogeneity that is correlated with labeling patterns for sodium channels and/or associated polyanionic sites. They have a nodelike ultrastructure and label heavily from near the heminode to the base of the macula. Their intramacular branches, less organized ultrastructurally, label only slightly. Results indicate that vestibular nerve fibers have one impulse initiation zone, located near the heminode, that varies in length according to nerve fiber type. Structural heterogeneity may favor impulse conduction in the central direction, and length of the impulse initiation zone could influence nerve discharge patterns.

Neurofibromatosis

MedlinePlus

... cranial nerves, which are called vestibular schwannomas or acoustic neuromas.. The tumors press on and damage neighboring ... cranial nerves, which are called vestibular schwannomas or acoustic neuromas.. The tumors press on and damage neighboring ...

Vestibular schwannomas: clinical results and quality of life after microsurgery or gamma knife radiosurgery.

PubMed

Myrseth, Erling; Møller, Per; Pedersen, Paal-Henning; Vassbotn, Flemming S; Wentzel-Larsen, Tore; Lund-Johansen, Morten

2005-05-01

The aim of the present study was to evaluate the overall treatment efficacy (tumor control, facial nerve function, complications) and quality of life for patients treated primarily for unilateral vestibular schwannomas of 30 mm or less, either by microsurgery or by gamma knife (GK) radiosurgery. The results for the two treatment groups are compared with each other, with main emphasis on the long-term quality of life. This is a retrospective study of 189 consecutive patients, 86 treated by microsurgery and 103 by gamma knife. The mean observation time was 5.9 years. All patients had a magnetic resonance imaging scan and clinical evaluation performed toward the end of the study. To evaluate the quality of life, we used two standardized questionnaires, the Glasgow Benefit Inventory and Short-Form 36. The questionnaires were sent to the 168 living patients. The reply rate was 83.3%. A total of 79.8% of the patients in the microsurgery group and 94.8% of the GK patients had a good facial nerve function (House-Brackmann Grade 1-2). Hearing was usually lost after microsurgery, whereas the GK patients had preserved hearing, which often became reduced over the years after the treatment. The treatment efficacy, defined as no need for additional treatment, was similar for the two treatment modalities. Quality of life was reduced compared with normative data, being most reduced in the microsurgery group. Some of the quality of life questions showed an association with facial nerve function and sex. Posttreatment facial nerve function, hearing, complication rates, and quality of life were all significantly in favor of GK radiosurgery.

Sclerosteosis involving the temporal bone: histopathologic aspects.

PubMed

Nager, G T; Hamersma, H

1986-01-01

Sclerosteosis is a rare, potentially lethal, autosomal recessive, progressive craniotubular sclerosing bone dysplasia with characteristic facial and skeletal features. The temporal bone changes include a marked increase in overall size, extensive sclerosis, narrowing of the external auditory canal, and severe constriction of the internal auditory meatus, fallopian canal, eustachian tube, and middle ear cleft. Attenuation of the bony canals of the 9th, 10th, and 11th cranial nerves, reduction in size of the internal carotid artery, and severe obliteration of the sigmoid sinus and jugular bulb also occur. Loss of hearing, generally bilateral, is a frequent symptom. It often manifests in early childhood and initially is expressed as sound conduction impairment. Later, a sensorineural hearing loss and loss of vestibular nerve function often develop. Impairment of facial nerve function is another feature occasionally present at birth. In the beginning, a unilateral intermittent facial weakness may occur which eventually progresses to a bilateral permanent facial paresis. The histologic examination of the temporal bones from a patient with sclerosteosis explains the mechanisms involved in the progressive impairment of sound conduction and loss of cochlear, vestibular, and facial nerve function. There is a decrease of the arterial blood supply to the brain and an obstruction of the venous drainage from it. The histopathology reveals the obstacles to decompression of the middle ear cleft, ossicular chain, internal auditory and facial canals, and the risks, and in many instances the contraindications, to such procedures. On the other hand, decompression of the sigmoid sinus and jugular bulb should be considered as an additional life-saving procedure in conjunction with the prophylactic craniotomy recommended in all adult patients.

Prevalence of clinical abnormalities in cats found to have nonneoplastic middle ear disease at necropsy: 59 cases (1991-2007).

PubMed

Schlicksup, Michael D; Van Winkle, Thomas J; Holt, David E

2009-10-01

To determine the prevalence of nonneoplastic middle ear disease among cats undergoing necropsy and the prevalence of clinical abnormalities in cats in which nonneoplastic middle ear disease was identified. Retrospective case series. 59 cats that underwent necropsy between January 1991 and August 2007. Medical records were searched to identify cats in which nonneoplastic middle ear disease was identified at necropsy. For cats included in the study, data that were recorded included signalment, initial complaint, whether the cat had any clinical signs of middle or external ear disease, whether the cat had upper respiratory tract disease, necropsy diagnosis, gross appearance of the bullae, and reason for euthanasia. Signs of middle ear disease that were considered included unilateral peripheral vestibular disease without motor deficits, Horner syndrome, and facial nerve paralysis. Of the 3,442 cats that underwent necropsy during the study period, 59 (1.7%) had nonneoplastic middle ear disease. Six of the 59 (10%) cats, including 1 cat that was affected bilaterally, had clinical signs of middle ear disease. Of these, 5 had signs of unilateral peripheral vestibular disease, and 1 had Horner syndrome. Results suggested that most cats with nonneoplastic middle ear disease did not have associated clinical signs. Findings may be of clinical relevance for cats in which middle ear disease is identified as an incidental finding during computed tomography or magnetic resonance imaging for unrelated diseases.

Responses of non-eye movement central vestibular neurons to sinusoidal horizontal translation in compensated macaques after unilateral labyrinthectomy

PubMed Central

Lin, Nan; Wei, Min

2014-01-01

After vestibular labyrinth injury, behavioral deficits partially recover through the process of vestibular compensation. The present study was performed to improve our understanding of the physiology of the macaque vestibular system in the compensated state (>7 wk) after unilateral labyrinthectomy (UL). Three groups of vestibular nucleus neurons were included: pre-UL control neurons, neurons ipsilateral to the lesion, and neurons contralateral to the lesion. The firing responses of neurons sensitive to linear acceleration in the horizontal plane were recorded during sinusoidal horizontal translation directed along six different orientations (30° apart) at 0.5 Hz and 0.2 g peak acceleration (196 cm/s2). This data defined the vector of best response for each neuron in the horizontal plane, along which sensitivity, symmetry, detection threshold, and variability of firing were determined. Additionally, the responses of the same cells to translation over a series of frequencies (0.25–5.0 Hz) either in the interaural or naso-occipital orientation were obtained to define the frequency response characteristics in each group. We found a decrease in sensitivity, increase in threshold, and alteration in orientation of best responses in the vestibular nuclei after UL. Additionally, the phase relationship of the best neural response to translational stimulation changed with UL. The symmetry of individual neuron responses in the excitatory and inhibitory directions was unchanged by UL. Bilateral central utricular neurons still demonstrated two-dimension tuning after UL, consistent with spatio-temporal convergence from a single vestibular end-organ. These neuronal data correlate with known behavioral deficits after unilateral vestibular compromise. PMID:24717349

A new saccadic indicator of peripheral vestibular function based on the video head impulse test

PubMed Central

MacDougall, Hamish G.; McGarvie, Leigh A.; Rogers, Stephen J.; Manzari, Leonardo; Burgess, Ann M.; Curthoys, Ian S.; Weber, Konrad P.

2016-01-01

Objective: While compensatory saccades indicate vestibular loss in the conventional head impulse test paradigm (HIMP), in which the participant fixates an earth-fixed target, we investigated a complementary suppression head impulse paradigm (SHIMP), in which the participant is fixating a head-fixed target to elicit anticompensatory saccades as a sign of vestibular function. Methods: HIMP and SHIMP eye movement responses were measured with the horizontal video head impulse test in patients with unilateral vestibular loss, patients with bilateral vestibular loss, and in healthy controls. Results: Vestibulo-ocular reflex gains showed close correlation (R2 = 0.97) with slightly lower SHIMP than HIMP gains (mean gain difference 0.06 ± 0.05 SD, p < 0.001). However, the 2 paradigms produced complementary catch-up saccade patterns: HIMP elicited compensatory saccades in patients but rarely in controls, whereas SHIMP elicited large anticompensatory saccades in controls, but smaller or no saccades in bilateral vestibular loss. Unilateral vestibular loss produced covert saccades in HIMP, but later and smaller saccades in SHIMP toward the affected side. Cumulative HIMP and SHIMP saccade amplitude differentiated patients from controls with high sensitivity and specificity. Conclusions: While compensatory saccades indicate vestibular loss in conventional HIMP, anticompensatory saccades in SHIMP using a head-fixed target indicate vestibular function. SHIMP saccades usually appear later than HIMP saccades, therefore being more salient to the naked eye and facilitating vestibulo-ocular reflex gain measurements. The new paradigm is intuitive and easy to explain to patients, and the SHIMP results complement those from the standard video head impulse test. Classification of evidence: This case-control study provides Class III evidence that SHIMP accurately identifies patients with unilateral or bilateral vestibulopathies. PMID:27251884

Model-based Vestibular Afferent Stimulation: Modular Workflow for Analyzing Stimulation Scenarios in Patient Specific and Statistical Vestibular Anatomy.

PubMed

Handler, Michael; Schier, Peter P; Fritscher, Karl D; Raudaschl, Patrik; Johnson Chacko, Lejo; Glueckert, Rudolf; Saba, Rami; Schubert, Rainer; Baumgarten, Daniel; Baumgartner, Christian

2017-01-01

Our sense of balance and spatial orientation strongly depends on the correct functionality of our vestibular system. Vestibular dysfunction can lead to blurred vision and impaired balance and spatial orientation, causing a significant decrease in quality of life. Recent studies have shown that vestibular implants offer a possible treatment for patients with vestibular dysfunction. The close proximity of the vestibular nerve bundles, the facial nerve and the cochlear nerve poses a major challenge to targeted stimulation of the vestibular system. Modeling the electrical stimulation of the vestibular system allows for an efficient analysis of stimulation scenarios previous to time and cost intensive in vivo experiments. Current models are based on animal data or CAD models of human anatomy. In this work, a (semi-)automatic modular workflow is presented for the stepwise transformation of segmented vestibular anatomy data of human vestibular specimens to an electrical model and subsequently analyzed. The steps of this workflow include (i) the transformation of labeled datasets to a tetrahedra mesh, (ii) nerve fiber anisotropy and fiber computation as a basis for neuron models, (iii) inclusion of arbitrary electrode designs, (iv) simulation of quasistationary potential distributions, and (v) analysis of stimulus waveforms on the stimulation outcome. Results obtained by the workflow based on human datasets and the average shape of a statistical model revealed a high qualitative agreement and a quantitatively comparable range compared to data from literature, respectively. Based on our workflow, a detailed analysis of intra- and extra-labyrinthine electrode configurations with various stimulation waveforms and electrode designs can be performed on patient specific anatomy, making this framework a valuable tool for current optimization questions concerning vestibular implants in humans.

Up-regulation of GAP-43 (B50/F1) gene expression in vestibular efferent neurons following labyrinthectomy in the rat: in situ hybridization using an alkaline phosphatase-labeled probe.

PubMed

Ohno, K; Takeda, N; Kubo, T; Kiyama, H

1994-10-01

Growth-associated protein (GAP)-43 plays a significant role in nerve regeneration and synaptic remodeling. We examined the profiles of GAP-43 mRNA expression in vestibular efferent neurons after labyrinthectomy in adult rats, and clearly demonstrated that labyrinthectomy increased GAP-43 expression in these neurons. This finding suggests the ability of vestibular efferent nerves to regenerate after nerve injury.

Video Head Impulse Testing (vHIT) and the Assessment of Horizontal Semicircular Canal Function.

PubMed

Riska, Kristal M; Murnane, Owen; Akin, Faith W; Hall, Courtney

2015-05-01

Vestibular function (specifically, horizontal semicircular canal function) can be assessed across a broad frequency range using several different techniques. The head impulse test is a qualitative test of horizontal semicircular canal function that can be completed at bedside. Recently, a new instrument (video head impulse test [vHIT]) has been developed to provide an objective assessment to the clinical test. Questions persist regarding how this test may be used in the overall vestibular test battery. The purpose of this case report is to describe vestibular test results (vHIT, rotational testing, vestibular evoked myogenic potentials, and balance and gait performance) in an individual with a 100% unilateral caloric weakness who was asymptomatic for dizziness, vertigo or imbalance. Comprehensive assessment was completed to evaluate vestibular function. Caloric irrigations, rotary chair testing, vHIT, and vestibular evoked myogenic potentials were completed. A 100% left-sided unilateral caloric weakness was observed in an asymptomatic individual. vHIT produced normal gain with covert saccades. This case demonstrates the clinical usefulness of vHIT as a diagnostic tool and indicator of vestibular compensation and functional status. American Academy of Audiology.

Central and peripheral components of short latency vestibular responses in the chicken

NASA Technical Reports Server (NTRS)

Nazareth, A. M.; Jones, T. A.

1998-01-01

Far-field recordings of short latency vestibular responses to pulsed cranial translation are composed of a series of positive and negative peaks occurring within 10 ms following stimulus onset. In the bird, these vestibular evoked potentials (VsEPs) can be recorded noninvasively and have been shown in the chicken and quail to depend strictly upon the activation of the vestibular component of the eighth nerve. The utility of the VsEP in the study of vestibular systems is dependent upon a clear understanding of the neural sources of response components. The primary aim of the current research in the chicken was to critically test the hypotheses that 1) responses are generated by both peripheral and central neurons and 2) peaks P1 and N1 originate from first order vestibular neurons, whereas later waves primarily depend on activity in higher order neurons. The principal strategy used here was to surgically isolate the eighth nerve as it enters the brainstem. Interruption of primary afferents of the eighth nerve in the brainstem substantially reduced or eliminated peaks beyond P2, whereas P1 and N1 were generally spared. Surgical sections that spared vestibular pathways had little effect on responses. The degree of change in response components beyond N1 was correlated with the extent of damage to central vestibular relays. These findings support the conclusion that responses are produced by both peripheral and central elements of the vestibular system. Further, response peaks later than N1 appear to be dependent upon central relays, whereas P1 and N1 reflect activity of the peripheral nerve. These findings clarify the roles of peripheral and central neurons in the generation of vestibular evoked potentials and provide the basis for a more useful and detailed interpretation of data from vestibular response testing.

Responses evoked by a vestibular implant providing chronic stimulation.

PubMed

Thompson, Lara A; Haburcakova, Csilla; Gong, Wangsong; Lee, Daniel J; Wall, Conrad; Merfeld, Daniel M; Lewis, Richard F

2012-01-01

Patients with bilateral vestibular loss experience dehabilitating visual, perceptual, and postural difficulties, and an implantable vestibular prosthesis that could improve these symptoms would be of great benefit to these patients. In previous work, we have shown that a one-dimensional, unilateral canal prosthesis can improve the vestibulooccular reflex (VOR) in canal-plugged squirrel monkeys. In addition to the VOR, the potential effects of a vestibular prosthesis on more complex, highly integrative behaviors, such as the perception of head orientation and posture have remained unclear. We tested a one-dimensional, unilateral prosthesis in a rhesus monkey with bilateral vestibular loss and found that chronic electrical stimulation partially restored the compensatory VOR and also that percepts of head orientation relative to gravity were improved. However, the one-dimensional prosthetic stimulation had no clear effect on postural stability during quiet stance, but sway evoked by head-turns was modestly reduced. These results suggest that not only can the implementation of a vestibular prosthesis provide partial restitution of VOR but may also improve perception and posture in the presence of bilateral vestibular hypofunction (BVH). In this review, we provide an overview of our previous and current work directed towards the eventual clinical implementation of an implantable vestibular prosthesis.

[The application of subjective visual gravity in assessment of vestibular compensation: a pilot study].

PubMed

Zhao, Yuan; Chen, Taisheng; Wang, Wei; Xu, Kaixu; Wen, Chao; Liu, Qiang; Han, Xi; Li, Shanshan; Li, Xiaojie; Lin, Peng

2016-05-01

To discuss the characteristics of subjective visual gravity (subjective visual vertical/horizontal, SVV/SVH) and assess its clinical application for peripheral unilateral vestibular compensation. 69 cases of acute peripheral unilateral vestibular dysfunction patients (case group) accepted SVV/SVH, spontaneous nystagmus (SN), caloric test (CT) and other vestibular function tests. 49 healthy people (control group) accepted SVV/SVH only. SVV/SVH, SN and unilateral weakness (UW) were selected as for the observation indicators. The correlations between SVV/SVH, SN, UW and courses were investigated respectively, as well as the characteristic of SVV/SVH, SN in period of vestibular compensation. Among case group SVV, SVH positive in 42 patients(60.9%) and 44 patients(63.8%), the absolute values of the skew angle were in the range between 2.1°-20.0°, 2.1°-22.2°. Skew angles of SVV/SVH in control were in the range between -1.5°-2.0° and -2.0°-1.6°, and had no statistical significance with case group(t=5.336 and 5.864, P<0.05). SN-positive 28 cases (40.6%), the range of intensities at 2.4°-17.1°; UW-positive 50 cases (72.5%). In case group, positive correlation between SVV and SVH(r=0.948, P=0.00), negatively correlated between SVV/SVH and SN respectively(r values were -0.720, -0.733, P values were 0.00), no correlation between the skew angle of SVV/SVH, strength of SN and UW value(r values were 0.191, 0.189, and 0.179, P>0.05), there was no correlation between the absolute value of SVV, SVH, SN, UW with the duration (rs values were -0.075, -0.065, -0.212, and 0.126, P>0.05). Subjective visual gravity can be used not only to assess the range of unilateral peripheral vestibular dysfunction, but also help assess the static compensatory of otolithic, guidance and assessment of vestibular rehabilitation.

The vestibulocochlear nerve (VIII).

PubMed

Benoudiba, F; Toulgoat, F; Sarrazin, J-L

2013-10-01

The vestibulocochlear nerve (8th cranial nerve) is a sensory nerve. It is made up of two nerves, the cochlear, which transmits sound and the vestibular which controls balance. It is an intracranial nerve which runs from the sensory receptors in the internal ear to the brain stem nuclei and finally to the auditory areas: the post-central gyrus and superior temporal auditory cortex. The most common lesions responsible for damage to VIII are vestibular Schwannomas. This report reviews the anatomy and various investigations of the nerve. Copyright © 2013. Published by Elsevier Masson SAS.

Characteristics of vertigo and the affected vestibular nerve systems in idiopathic bilateral vestibulopathy.

PubMed

Fujimoto, Chisato; Kinoshita, Makoto; Kamogashira, Teru; Egami, Naoya; Sugasawa, Keiko; Yamasoba, Tatsuya; Iwasaki, Shinichi

2016-01-01

Vertigo attacks in IBV patients involving both the superior and inferior vestibular nerve systems were significantly more severe than vertigo attacks in patients with selective involvement of the inferior vestibular nerve system alone. To investigate the relationship between the frequency and duration of vertigo and the affected vestibular nerve system in idiopathic bilateral vestibulopathy (IBV). This study categorized 44 IBV patients into the following three sub-groups according to the affected vestibular nerve system: superior, inferior, and mixed type. These patients were also categorized into the following three sub-groups according to their clinical time course: progressive type showing no episodes of vertigo, sequential type showing recurrent vertigo attacks and single-attack type showing a single episode of vertigo. Ten, 11 and 23 patients were classified as the superior, the inferior, and the mixed type, respectively. Seventeen, 23, and four patients were classified as the progressive, the sequential, and the single-attack type, respectively. For the patients having one or more vertigo attacks, the duration of the vertigo attack was longer than 24 h in 69% of the mixed type, and the duration of vertigo in the mixed type was significantly longer than that in the inferior type (p < 0.05).

Brainstem abnormalities and vestibular nerve enhancement in acute neuroborreliosis.

PubMed

Farshad-Amacker, Nadja A; Scheffel, Hans; Frauenfelder, Thomas; Alkadhi, Hatem

2013-12-21

Borreliosis is a widely distributed disease. Neuroborreliosis may present with unspecific symptoms and signs and often remains difficult to diagnose in patients with central nervous system symptoms, particularly if the pathognomonic erythema chronica migrans does not develop or is missed. Thus, vigilance is mandatory in cases with atypical presentation of the disease and with potentially severe consequences if not recognized early. We present a patient with neuroborreliosis demonstrating brain stem and vestibular nerve abnormalities on magnetic resonance imaging. A 28-year-old Caucasian female presented with headaches, neck stiffness, weight loss, nausea, tremor, and gait disturbance. Magnetic resonance imaging showed T2-weighted hyperintense signal alterations in the pons and in the vestibular nerves as well as bilateral post-contrast enhancement of the vestibular nerves. Serologic testing of the cerebrospinal fluid revealed the diagnosis of neuroborreliosis. Patients infected with neuroborreliosis may present with unspecific neurologic symptoms and magnetic resonance imaging as a noninvasive imaging tool showing signal abnormalities in the brain stem and nerve root enhancement may help in establishing the diagnosis.

Asymmetric vestibular stimulation reveals persistent disruption of motion perception in unilateral vestibular lesions.

PubMed

Panichi, R; Faralli, M; Bruni, R; Kiriakarely, A; Occhigrossi, C; Ferraresi, A; Bronstein, A M; Pettorossi, V E

2017-11-01

Self-motion perception was studied in patients with unilateral vestibular lesions (UVL) due to acute vestibular neuritis at 1 wk and 4, 8, and 12 mo after the acute episode. We assessed vestibularly mediated self-motion perception by measuring the error in reproducing the position of a remembered visual target at the end of four cycles of asymmetric whole-body rotation. The oscillatory stimulus consists of a slow (0.09 Hz) and a fast (0.38 Hz) half cycle. A large error was present in UVL patients when the slow half cycle was delivered toward the lesion side, but minimal toward the healthy side. This asymmetry diminished over time, but it remained abnormally large at 12 mo. In contrast, vestibulo-ocular reflex responses showed a large direction-dependent error only initially, then they normalized. Normalization also occurred for conventional reflex vestibular measures (caloric tests, subjective visual vertical, and head shaking nystagmus) and for perceptual function during symmetric rotation. Vestibular-related handicap, measured with the Dizziness Handicap Inventory (DHI) at 12 mo correlated with self-motion perception asymmetry but not with abnormalities in vestibulo-ocular function. We conclude that 1 ) a persistent self-motion perceptual bias is revealed by asymmetric rotation in UVLs despite vestibulo-ocular function becoming symmetric over time, 2 ) this dissociation is caused by differential perceptual-reflex adaptation to high- and low-frequency rotations when these are combined as with our asymmetric stimulus, 3 ) the findings imply differential central compensation for vestibuloperceptual and vestibulo-ocular reflex functions, and 4 ) self-motion perception disruption may mediate long-term vestibular-related handicap in UVL patients. NEW & NOTEWORTHY A novel vestibular stimulus, combining asymmetric slow and fast sinusoidal half cycles, revealed persistent vestibuloperceptual dysfunction in unilateral vestibular lesion (UVL) patients. The compensation of motion perception after UVL was slower than that of vestibulo-ocular reflex. Perceptual but not vestibulo-ocular reflex deficits correlated with dizziness-related handicap. Copyright © 2017 the American Physiological Society.

Effectiveness of conventional versus virtual reality based vestibular rehabilitation in the treatment of dizziness, gait and balance impairment in adults with unilateral peripheral vestibular loss: a randomised controlled trial.

PubMed

Meldrum, Dara; Herdman, Susan; Moloney, Roisin; Murray, Deirdre; Duffy, Douglas; Malone, Kareena; French, Helen; Hone, Stephen; Conroy, Ronan; McConn-Walsh, Rory

2012-03-26

Unilateral peripheral vestibular loss results in gait and balance impairment, dizziness and oscillopsia. Vestibular rehabilitation benefits patients but optimal treatment remains unknown. Virtual reality is an emerging tool in rehabilitation and provides opportunities to improve both outcomes and patient satisfaction with treatment. The Nintendo Wii Fit Plus® (NWFP) is a low cost virtual reality system that challenges balance and provides visual and auditory feedback. It may augment the motor learning that is required to improve balance and gait, but no trials to date have investigated efficacy. In a single (assessor) blind, two centre randomised controlled superiority trial, 80 patients with unilateral peripheral vestibular loss will be randomised to either conventional or virtual reality based (NWFP) vestibular rehabilitation for 6 weeks. The primary outcome measure is gait speed (measured with three dimensional gait analysis). Secondary outcomes include computerised posturography, dynamic visual acuity, and validated questionnaires on dizziness, confidence and anxiety/depression. Outcome will be assessed post treatment (8 weeks) and at 6 months. Advances in the gaming industry have allowed mass production of highly sophisticated low cost virtual reality systems that incorporate technology previously not accessible to most therapists and patients. Importantly, they are not confined to rehabilitation departments, can be used at home and provide an accurate record of adherence to exercise. The benefits of providing augmented feedback, increasing intensity of exercise and accurately measuring adherence may improve conventional vestibular rehabilitation but efficacy must first be demonstrated. Clinical trials.gov identifier: NCT01442623.

Vestibular neurolabyrinthitis: a follow-up study with cervical and ocular vestibular evoked myogenic potentials and the video head impulse test.

PubMed

Magliulo, Giuseppe; Gagliardi, Silvia; Ciniglio Appiani, Mario; Iannella, Giannicola; Re, Massimo

2014-03-01

The aim of this study was to evaluate prospectively, in a group of patients affected by vestibular neurolabyrinthitis (VN), a diagnostic protocol including cervical vestibular evoked myogenic potentials (C-VEMPs), ocular vestibular evoked myogenic potentials (O-VEMPs), and the video head impulse test (vHIT). The diagnosis of VN was based on the patient's clinical history, an absence of associated auditory or neurologic symptoms, and a neuro-otological examination with an evaluation of lateral semicircular canal function by use of the Fitzgerald-Hallpike caloric vestibular test and the ice test. In our series, 55% of the cases were superior and inferior VN, 40% were superior VN, and 5% were inferior VN. These cases, however, comprised different degrees of vestibular involvement, as the individual vestibular end organs have different prognoses. Four patients had only deficits of the horizontal and superior semicircular canals or their ampullary nerves. The implementation of C-VEMPs, O-VEMPs, and the vHIT in a vestibular diagnostic protocol has made it possible to observe patients with ampullary VN in a way that has not been feasible with other types of vestibular examinations. The age of the patient seems to have some impact on recovery from VN. When recovery occurs in the utricular and saccular nerves first and in the ampullary nerves subsequently, it may be reasonable to expect a more favorable outcome.

Correlation of Fos expression and circling asymmetry during gerbil vestibular compensation

NASA Technical Reports Server (NTRS)

Kaufman, G. D.; Shinder, M. E.; Perachio, A. A.

1999-01-01

Vestibular compensation is a central nervous system process resulting in recovery of functional movement and control following a unilateral vestibular lesion. Small pressure injections of phosphorothioate 20mer oligonucleotides were used to probe the role of the Fos transcription protein during vestibular compensation in the gerbil brainstem. During isoflurane gas anesthesia, antisense probes against the c-fos mRNA sequence were injected into the medial vestibular and prepositus nuclei unilaterally prior to a unilateral surgical labyrinthectomy. Anionic dyes, which did not interact with the oligonucleotides, were used to mark the injection site and help determine the extent of diffusion. The antiFos oligonucleotide injections reduced Fos expression at the injection site in neurons which normally express Fos after the lesion, and also affected circling behavior induced by hemilabyrinthectomy. With both ipsilateral and contralateral medial vestibular and prepositus nuclei injections, less ipsilateral and more contralateral circling was noted in animals injected with antiFos injections as compared to non-injected controls. The degree of change in these behaviors was dependent upon the side of the injection. Histologically, antiFos injections reduced the number of Fos immunolabeled neurons around the injection site, and increased Fos expression contralaterally. The correlation of the number of neurons with Fos expression to turning behavior was stronger for contralateral versus ipsilateral turns, and for neurons in the caudal and ipsilateral sub-regions of the medial vestibular and prepositus nuclei. The results are discussed in terms of neuronal firing activity versus translational activity based on the asymmetrical expression of the Fos inducible transcription factor in the medial vestibular and prepositus nuclei. Although ubiquitous in the brain, transcription factors like Fos can serve localized and specific roles in sensory-specific adaptive stimuli. Antisense injections can be an effective procedure for localized intervention into complex physiological functions, e.g. vestibular compensation. Copyright 1999 Elsevier Science B.V.

Differential Involvement during Latent Herpes Simplex Virus 1 Infection of the Superior and Inferior Divisions of the Vestibular Ganglia: Implications for Vestibular Neuritis

PubMed Central

Lindemann, Anja; Sinicina, Inga; Horn, Anja K. E.; Brandt, Thomas; Strupp, Michael; Hüfner, Katharina

2017-01-01

ABSTRACT Controversy still surrounds both the etiology and pathophysiology of vestibular neuritis (VN). Especially uncertain is why the superior vestibular nerve (SVN) is more frequently affected than the inferior vestibular nerve (IVN), which is partially or totally spared. To address this question, we developed an improved method for preparing human vestibular ganglia (VG) and nerve. Subsequently, macro- and microanatomical as well as PCR studies were performed on 38 human ganglia from 38 individuals. The SVN was 2.4 mm longer than the IVN, and in 65% of the cases, the IVN ran in two separate bony canals, which was not the case for the SVN. Anastomoses between the facial and cochlear nerves were more common for the SVN (14/38 and 9/38, respectively) than for the IVN (7/38 and 2/38, respectively). Using reverse transcription-quantitative PCR (RT-qPCR), we found only a few latently herpes simplex virus 1 (HSV-1)-infected VG (18.4%). In cases of two separate neuronal fields, infected neurons were located in the superior part only. In summary, these PCR and micro- and macroanatomical studies provide possible explanations for the high frequency of SVN infection in vestibular neuritis. IMPORTANCE Vestibular neuritis is known to affect the superior part of the vestibular nerve more frequently than the inferior part. The reason for this clinical phenomenon remains unclear. Anatomical differences may play a role, or if latent HSV-1 infection is assumed, the etiology may be due to the different distribution of the infection. To shed further light on this subject, we conducted different macro- and microanatomical studies. We also assessed the presence of HSV-1 in VG and in different sections of the VG. Our findings add new information on the macro- and microanatomy of the VG as well as the pathophysiology of vestibular neuritis. We also show that latent HSV-1 infection of VG neurons is less frequent than previously reported. PMID:28446678

Differential Involvement during Latent Herpes Simplex Virus 1 Infection of the Superior and Inferior Divisions of the Vestibular Ganglia: Implications for Vestibular Neuritis.

PubMed

Himmelein, Susanne; Lindemann, Anja; Sinicina, Inga; Horn, Anja K E; Brandt, Thomas; Strupp, Michael; Hüfner, Katharina

2017-07-15

Controversy still surrounds both the etiology and pathophysiology of vestibular neuritis (VN). Especially uncertain is why the superior vestibular nerve (SVN) is more frequently affected than the inferior vestibular nerve (IVN), which is partially or totally spared. To address this question, we developed an improved method for preparing human vestibular ganglia (VG) and nerve. Subsequently, macro- and microanatomical as well as PCR studies were performed on 38 human ganglia from 38 individuals. The SVN was 2.4 mm longer than the IVN, and in 65% of the cases, the IVN ran in two separate bony canals, which was not the case for the SVN. Anastomoses between the facial and cochlear nerves were more common for the SVN (14/38 and 9/38, respectively) than for the IVN (7/38 and 2/38, respectively). Using reverse transcription-quantitative PCR (RT-qPCR), we found only a few latently herpes simplex virus 1 (HSV-1)-infected VG (18.4%). In cases of two separate neuronal fields, infected neurons were located in the superior part only. In summary, these PCR and micro- and macroanatomical studies provide possible explanations for the high frequency of SVN infection in vestibular neuritis. IMPORTANCE Vestibular neuritis is known to affect the superior part of the vestibular nerve more frequently than the inferior part. The reason for this clinical phenomenon remains unclear. Anatomical differences may play a role, or if latent HSV-1 infection is assumed, the etiology may be due to the different distribution of the infection. To shed further light on this subject, we conducted different macro- and microanatomical studies. We also assessed the presence of HSV-1 in VG and in different sections of the VG. Our findings add new information on the macro- and microanatomy of the VG as well as the pathophysiology of vestibular neuritis. We also show that latent HSV-1 infection of VG neurons is less frequent than previously reported. Copyright © 2017 American Society for Microbiology.

Utility of the hyperventilation test in the evaluation of the dizzy patient.

PubMed

Califano, Luigi; Mazzone, Salvatore; Salafia, Francesca

2013-10-01

The aim of the review is to value the incidence, patterns and temporal characteristics of hyperventilation-induced nystagmus (HVIN) in patients suffering from vestibular diseases, as well as its contribution to the differential diagnosis between vestibular neuritis and schwannoma of the eighth cranial nerve and its behavior in some central vestibular diseases. The hyperventilation test seems to be more useful than other bedside tests in detecting schwannoma of the eighth cranial nerve in the case of sudden monolateral hypacusia. The presence of an excitatory pattern of HVIN in vestibular schwannoma that has undergone to stereotactic surgery reveals that this therapy produces demyelinization in neural fibers. The hyperventilation test is easy to perform, well tolerated and able to reveal latent vestibular asymmetries; it acts both at peripheral and central vestibular levels through metabolic mechanisms or, more rarely, through changes in cerebrospinal fluid pressure. It can provide patterns of oculomotor responses suggesting the execution of gadolinium-enhanced MRI, upon the suspicion of schwannoma of the eighth cranial nerve or of a central disease. In our opinion, the presence of HVIN always needs to be viewed within the more general context of a complete examination of auditory and vestibular systems.

[Vestibular paroxismia].

PubMed

Likhachev, S A; Mar'enko, I P; Antonenko, A I

2013-01-01

The objective of the present publication was to demonstrate a clinical case of peripheral vestibular paroxismia verified in a woman with the help of the MRI technique. Vestibular paroxismia is a relatively rare disease manifested in such characteristic signs and symptoms as sudden and short-lived episodes of dizziness, unstable gait, and the concomitant vegetative disorders accompanied as a rule by tympanophonia, impairment of hearing, and falls. In typical cases, the duration of such episodes varies from several minutes to a few days. A case of vestibular paroxismia associated with the lesion in the peripheral section of the vestibular system is described; it was caused by compression of the nerve by a blood vessel as shown by means of magnetic resonance imaging of cranial nerves.

Diagnostics and therapy of vestibular schwannomas – an interdisciplinary challenge

PubMed Central

Rosahl, Steffen; Bohr, Christopher; Lell, Michael; Hamm, Klaus; Iro, Heinrich

2017-01-01

Vestibular schwannomas (VS) expand slowly in the internal auditory canal, in the cerebellopontine angle, inside the cochlear and the labyrinth. Larger tumors can displace and compress the brainstem. With an annual incidence of 1:100,000 vestibular schwannoma represent 6–7% of all intracranial tumors. In the cerebellopontine angle they are by far the most neoplasm with 90% of all lesions located in this region. Magnetic resonance imaging (MRI), audiometry, and vestibular diagnostics are the mainstays of the clinical workup for patients harboring tumors. The first part of this paper delivers an overview of tumor stages, the most common grading scales for facial nerve function and hearing as well as a short introduction to the examination of vestibular function. Upholding or improving quality of life is the central concern in counseling and treating a patient with vestibular schwannoma. Preservation of neuronal function is essential and the management options – watchful waiting, microsurgery and stereotactic radiation – should be custom-tailored to the individual situation of the patient. Continuing interdisciplinary exchange is important to monitor treatment quality and to improve treatment results. Recently, several articles and reviews have been published on the topic of vestibular schwannoma. On the occasion of the 88th annual meeting of the German Society of Oto-Rhino-Laryngology, Head and Neck surgery a special volume of the journal “HNO” will be printed. Hence this presentation has been designed to deviate from the traditional standard which commonly consists of a pure literature review. The current paper was conceptually woven around a series of interdisciplinary cases that outline examples for every stage of the disease that show characteristic results for management options to date. Systematic clinical decision pathways have been deduced from our experience and from results reported in the literature. These pathways are graphically outlined after the case presentations. Important criteria for decision making are size and growth rate of the tumor, hearing of the patient and the probability of total tumor resection with preservation of hearing and facial nerve function, age and comorbidity of the patient, best possible control of vertigo and tinnitus and last but not least the patient’s preference and choice. In addition to this, the experience and the results of a given center with each treatment modality will figure in the decision making process. We will discuss findings that are reported in the literature regarding facial nerve function, hearing, vertigo, tinnitus, and headache and reflect on recent studies on their influence on the patient’s quality of life. Vertigo plays an essential role in this framework since it is an independent predictor of quality of life and a patient’s dependence on social welfare. Pathognomonic bilateral vestibular schwannomas that occur in patients suffering from neurofibromatosis typ-2 (NF2) differ from spontaneous unilateral tumors in their biologic behavior. Treatment of neurofibromatosis type-2 patients requires a multidisciplinary team, especially because of the multitude of separate intracranial and spinal lesions. Off-label chemotherapy with Bevacizumab can stabilize tumor size of vestibular schwannomas and even improve hearing over longer periods of time. Hearing rehabilitation in NF2 patients can be achieved with cochlear and auditory brainstem implants. PMID:29279723

The Frog Vestibular System as a Model for Lesion-Induced Plasticity: Basic Neural Principles and Implications for Posture Control

PubMed Central

Lambert, François M.; Straka, Hans

2011-01-01

Studies of behavioral consequences after unilateral labyrinthectomy have a long tradition in the quest of determining rules and limitations of the central nervous system (CNS) to exert plastic changes that assist the recuperation from the loss of sensory inputs. Frogs were among the first animal models to illustrate general principles of regenerative capacity and reorganizational neural flexibility after a vestibular lesion. The continuous successful use of the latter animals is in part based on the easy access and identifiability of nerve branches to inner ear organs for surgical intervention, the possibility to employ whole brain preparations for in vitro studies and the limited degree of freedom of postural reflexes for quantification of behavioral impairments and subsequent improvements. Major discoveries that increased the knowledge of post-lesional reactive mechanisms in the CNS include alterations in vestibular commissural signal processing and activation of cooperative changes in excitatory and inhibitory inputs to disfacilitated neurons. Moreover, the observed increase of synaptic efficacy in propriospinal circuits illustrates the importance of limb proprioceptive inputs for postural recovery. Accumulated evidence suggests that the lesion-induced neural plasticity is not a goal-directed process that aims toward a meaningful restoration of vestibular reflexes but rather attempts a survival of those neurons that have lost their excitatory inputs. Accordingly, the reaction mechanism causes an improvement of some components but also a deterioration of other aspects as seen by spatio-temporally inappropriate vestibulo-motor responses, similar to the consequences of plasticity processes in various sensory systems and species. The generality of the findings indicate that frogs continue to form a highly amenable vertebrate model system for exploring molecular and physiological events during cellular and network reorganization after a loss of vestibular function. PMID:22518109

Small vestibular schwannomas presenting with facial nerve palsy.

PubMed

Espahbodi, Mana; Carlson, Matthew L; Fang, Te-Yung; Thompson, Reid C; Haynes, David S

2014-06-01

To describe the surgical management and convalescence of two patients presenting with severe facial nerve weakness associated with small intracanalicular vestibular schwannomas (VS). Retrospective review. Two adult female patients presenting with audiovestibular symptoms and subacute facial nerve paralysis (House-Brackmann Grade IV and V). In both cases, post-contrast T1-weighted magnetic resonance imaging revealed an enhancing lesion within the internal auditory canal without lateral extension beyond the fundus. Translabyrinthine exploration demonstrated vestibular nerve origin of tumor, extrinsic to the facial nerve, and frozen section pathology confirmed schwannoma. Gross total tumor resection with VIIth cranial nerve preservation and decompression of the labyrinthine segment of the facial nerve was performed. Both patients recovered full motor function between 6 and 8 months after surgery. Although rare, small VS may cause severe facial neuropathy, mimicking the presentation of facial nerve schwannomas and other less common pathologies. In the absence of labyrinthine extension on MRI, surgical exploration is the only reliable means of establishing a diagnosis. In the case of confirmed VS, early gross total resection with facial nerve preservation and labyrinthine segment decompression may afford full motor recovery-an outcome that cannot be achieved with facial nerve grafting.

Effectiveness of conventional versus virtual reality-based balance exercises in vestibular rehabilitation for unilateral peripheral vestibular loss: results of a randomized controlled trial.

PubMed

Meldrum, Dara; Herdman, Susan; Vance, Roisin; Murray, Deirdre; Malone, Kareena; Duffy, Douglas; Glennon, Aine; McConn-Walsh, Rory

2015-07-01

To compare the effectiveness of virtual reality-based balance exercises to conventional balance exercises during vestibular rehabilitation in patients with unilateral peripheral vestibular loss (UVL). Assessor-blind, randomized controlled trial. Two acute care university teaching hospitals. Patients with UVL (N=71) who had dizziness/vertigo, and gait and balance impairment. Patients with UVL were randomly assigned to receive 6 weeks of either conventional (n=36) or virtual reality-based (n=35) balance exercises during vestibular rehabilitation. The virtual reality-based group received an off-the-shelf virtual reality gaming system for home exercise, and the conventional group received a foam balance mat. Treatment comprised weekly visits to a physiotherapist and a daily home exercise program. The primary outcome was self-preferred gait speed. Secondary outcomes included other gait parameters and tasks, Sensory Organization Test (SOT), dynamic visual acuity, Hospital Anxiety and Depression Scale, Vestibular Rehabilitation Benefits Questionnaire, and Activities Balance Confidence Questionnaire. The subjective experience of vestibular rehabilitation was measured with a questionnaire. Both groups improved, but there were no significant differences in gait speed between the groups postintervention (mean difference, -.03m/s; 95% confidence interval [CI], -.09 to .02m/s). There were also no significant differences between the groups in SOT scores (mean difference, .82%; 95% CI, -5.00% to 6.63%) or on any of the other secondary outcomes (P>.05). In both groups, adherence to exercise was high (∼77%), but the virtual reality-based group reported significantly more enjoyment (P=.001), less difficulty with (P=.009) and less tiredness after (P=.03) balance exercises. At 6 months, there were no significant between-group differences in physical outcomes. Virtual reality-based balance exercises performed during vestibular rehabilitation were not superior to conventional balance exercises during vestibular rehabilitation but may provide a more enjoyable method of retraining balance after unilateral peripheral vestibular loss. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

State Anxiety Subjective Imbalance and Handicap in Vestibular Schwannoma.

PubMed

Saman, Yougan; Mclellan, Lucie; Mckenna, Laurence; Dutia, Mayank B; Obholzer, Rupert; Libby, Gerald; Gleeson, Michael; Bamiou, Doris-Eva

2016-01-01

Evidence is emerging for a significant clinical and neuroanatomical relationship between balance and anxiety. Research has suggested a potentially priming effect with anxiety symptoms predicting a worsening of balance function in patients with underlying balance dysfunction. We propose to show that a vestibular stimulus is responsible for an increase in state anxiety, and there is a relationship between increased state anxiety and worsening balance function. (1) To quantify state anxiety following a vestibular stimulus in patients with a chronic vestibular deficit. (2) To determine if state anxiety during a vestibular stimulus would correlate with the severity of chronic balance symptoms and handicap. Two separate cohorts of vestibular schwannoma (VS) patients underwent vestibular tests (electronystagmography, cervical and ocular vestibular evoked myogenic potentials, and caloric responses) and questionnaire assessments [vertigo handicap questionnaire (VHQ), vertigo symptom scale (VSS), and state-trait anxiety inventory (STAIY)]. Fifteen post-resection VS patients, with complete unilateral vestibular deafferentation, were assessed at a minimum of 6 months after surgery in Experiment 1 (Aim 1). Forty-five patients with VS in situ formed the cohort for Experiment 2 (Aim 2). Experiment 1: VS subjects (N = 15) with a complete post-resection unilateral vestibular deafferentation completed a state anxiety questionnaire before caloric assessment and again afterward with the point of maximal vertigo as the reference (Aim 1). Experiment 2: state anxiety measured at the point of maximal vertigo following a caloric assessment was compared between two groups of patients with VS in situ presenting with balance symptoms (Group 1, N = 26) and without balance symptoms (Group 2, N = 11) (Aim 2). The presence of balance symptoms was defined as having a positive score on the VSS-VER. In Experiment 1, a significant difference (p < 0.01) was found when comparing STAIY at baseline and at the peak of the subjective vertiginous response in post-resection patients with a unilateral vestibular deafferentation. In Experiment 2, VS in situ patients with balance symptoms had significantly worse state anxiety at the peak vertiginous response than patients without balance symptoms (p < 0.001), as did patients with a balance-related handicap (p < 0.001). Anxiety symptoms during a vestibular stimulus may contribute to a priming effect that could explain worsening balance function.

Immunohistochemical profile of cytokines and growth factors expressed in vestibular schwannoma and in normal vestibular nerve tissue.

PubMed

Taurone, Samanta; Bianchi, Enrica; Attanasio, Giuseppe; Di Gioia, Cira; Ierinó, Rocco; Carubbi, Cecilia; Galli, Daniela; Pastore, Francesco Saverio; Giangaspero, Felice; Filipo, Roberto; Zanza, Christian; Artico, Marco

2015-07-01

Vestibular schwannomas, also known as acoustic neuromas, are benign tumors, which originate from myelin-forming Schwann cells. They develop in the vestibular branch of the eighth cranial nerve in the internal auditory canal or cerebellopontine angle. The clinical progression of the condition involves slow and progressive growth, eventually resulting in brainstem compression. The objective of the present study was to investigate the expression level and the localization of the pro-inflammatory cytokines, transforming growth factor-β1 (TGF-β1) interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α), as well as the adhesion molecules, intracellular adhesion molecule-1 and vascular endothelial growth factor (VEGF), in order to determine whether these factors are involved in the transformation and development of human vestibular schwannoma. The present study investigated whether changes in inflammation are involved in tumor growth and if so, the mechanisms underlying this process. The results of the current study demonstrated that pro-inflammatory cytokines, including TGF-β1, IL-1β and IL-6 exhibited increased expression in human vestibular schwannoma tissue compared with normal vestibular nerve samples. TNF-α was weakly expressed in Schwann cells, confirming that a lower level of this cytokine is involved in the proliferation of Schwann cells. Neoplastic Schwann cells produce pro-inflammatory cytokines that may act in an autocrine manner, stimulating cellular proliferation. In addition, the increased expression of VEGF in vestibular schwannoma compared with that in normal vestibular nerve tissue, suggests that this factor may induce neoplastic growth via the promotion of angiogenesis. The present findings suggest that inflammation may promote angiogenesis and consequently contribute to tumor progression. In conclusion, the results of the present study indicated that VEGF and pro-inflammatory cytokines may be potential therapeutic targets in vestibular schwannoma. Further studies are necessary to confirm the involvement of these factors in the growth of neoplasms and to develop inhibitors of pro-inflammatory cytokines as a potential treatment option in the future.

Ocular vestibular evoked myogenic potential elicited from binaural air-conducted stimulations: clinical feasibility in patients with peripheral vestibular dysfunction.

PubMed

Iwasaki, Shinichi; Egami, Naoya; Inoue, Aki; Kinoshita, Makoto; Fujimoto, Chisato; Murofushi, Toshihisa; Yamasoba, Tatsuya

2013-07-01

Ocular vestibular evoked myogenic potentials (oVEMPs) to binaural air-conducted stimulation (ACS) may provide a convenient way of assessing the crossed vestibulo-ocular reflex in patients with vestibular dysfunction as well as in healthy subjects. To investigate the clinical feasibility of using oVEMPs in response to binaural ACS to assess normal subjects and patients with vestibular dysfunction. The study investigated 24 normal subjects (14 men and 10 women, aged from 23 to 60 years) and 14 patients with unilateral peripheral vestibular dysfunction. Each subject underwent oVEMP testing in response to monaural ACS and binaural ACS (500 Hz tone burst, 135 dBSPL). In normal subjects, bilateral oVEMPs were elicited in 75% of subjects in response to monaural ACS and in 91% in response to binaural ACS. Asymmetry ratios (ARs) of the responses to binaural ACS were significantly smaller than those of the responses to monaural ACS (p < 0.01). In patients with unilateral vestibular dysfunction, there were no significant differences in the amplitude, latency, or AR of the responses between monaural and binaural ACS. Approximately 30% of patients showed reduced ARs to binaural ACS relative to monaural ACS, primarily due to contamination by uncrossed responses elicited in healthy ears.

Health-related quality of life and disability in patients with acute unilateral peripheral vestibular disorders.

PubMed

Petri, Maria; Chirilă, Magdalena; Bolboacă, Sorana D; Cosgarea, Marcel

Health-related quality of life is used to denote that portion of the quality of life that is influenced by the person's health. To compare the health-related quality of life of individuals with vestibular disorders of peripheral origin by analyzing functional, emotional and physical disabilities before and after vestibular treatment. A prospective, non randomized case-controlled study was conduced in the ENT Department, between January 2015 and December 2015. All patients were submitted to customize a 36 item of health survey on quality of life, short form 36 health survey questionnaire (SF-36) and the Dizziness Handicap Inventory for assessing the disability. Individuals were diagnosed with acute unilateral vestibular peripheral disorders classified in 5 groups: vestibular neuritis, Ménière Disease, Benign Paroxysmal Positional Vertigo, cochlear-vestibular dysfunction (other than Ménière Disease), or other type of acute peripheral vertigo (as vestibular migraine). There was a statistical significant difference for each parameter of Dizziness Handicap Inventory score (the emotional, functional and physical) between the baseline and one month both in men and women, but with any statistical significant difference between 7 days and 14 days. It was found a statistical significant difference for all eight parameters of SF-36 score between the baseline and one month later both in men and women; the exception was the men mental health perception. The correlation between the Dizziness Handicap Inventory and the SF-36 scores according to diagnostics type pointed out that the Spearman's correlation coefficient was moderate correlated with the total scores of these instruments. The Dizziness Handicap Inventory and the SF-36 are useful, proved practical and valid instruments for assessing the impact of dizziness on the quality of life of patients with unilateral peripheral vestibular disorders. Copyright © 2016 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Large basolateral processes on type II hair cells comprise a novel processing unit in mammalian vestibular organs

PubMed Central

Pujol, Rémy; Pickett, Sarah B.; Nguyen, Tot Bui; Stone, Jennifer S.

2014-01-01

Sensory receptors in the vestibular system (hair cells) encode head movements and drive central motor reflexes that control gaze, body movements, and body orientation. In mammals, type I and II vestibular hair cells are defined by their shape, contacts with vestibular afferent nerves, and membrane conductance. Here, we describe unique morphological features of type II vestibular hair cells in mature rodents (mice and gerbils) and bats. These features are cytoplasmic processes that extend laterally from the hair cell’s base and project under type I hair cells. Closer analysis of adult mouse utricles demonstrated that the basolateral processes of type II hair cells range in shape, size, and branching, with the longest processes extending 3–4 hair cell widths. The hair cell basolateral processes synapse upon vestibular afferent nerves and receive inputs from vestibular efferent nerves. Further, some basolateral processes make physical contacts with the processes of other type II hair cells, forming some sort of network amongst type II hair cells. Basolateral processes are rare in perinatal mice and do not attain their mature form until 3–6 weeks of age. These observations demonstrate that basolateral processes are significant signaling regions of type II vestibular hair cells, and they suggest type II hair cells may directly communicate with each other, which has not been described in vertebrates. PMID:24825750

Large basolateral processes on type II hair cells are novel processing units in mammalian vestibular organs.

PubMed

Pujol, Rémy; Pickett, Sarah B; Nguyen, Tot Bui; Stone, Jennifer S

2014-10-01

Sensory receptors in the vestibular system (hair cells) encode head movements and drive central motor reflexes that control gaze, body movements, and body orientation. In mammals, type I and II vestibular hair cells are defined by their shape, contacts with vestibular afferent nerves, and membrane conductance. Here we describe unique morphological features of type II vestibular hair cells in mature rodents (mice and gerbils) and bats. These features are cytoplasmic processes that extend laterally from the hair cell base and project under type I hair cells. Closer analysis of adult mouse utricles demonstrated that the basolateral processes of type II hair cells vary in shape, size, and branching, with the longest processes extending three to four hair cell widths. The hair cell basolateral processes synapse upon vestibular afferent nerves and receive inputs from vestibular efferent nerves. Furthermore, some basolateral processes make physical contacts with the processes of other type II hair cells, forming some sort of network among type II hair cells. Basolateral processes are rare in perinatal mice and do not attain their mature form until 3-6 weeks of age. These observations demonstrate that basolateral processes are significant signaling regions of type II vestibular hair cells and suggest that type II hair cells may directly communicate with each other, which has not been described in vertebrates. © 2014 Wiley Periodicals, Inc.

[The clinical manifestations and neurophysiological features of long-lasting paroxysmal vertigo:theanalysis of the original observations].

PubMed

Likhachev, S A; Mar'enko, I P

2015-01-01

The objective of the present study was to elucidate specific features of etiology and pathophysiology of recurring chronic vestibular dysfunction. It included 90 patients with this pathology of whom 24 (26.6%) presented with vascular compression of the vestibulocochlear nerve diagnosed by means of high-field MRI. This method revealed the high frequency of positionally-dependent vestibular dysfunction associated with neurovascular interactions. Analysis of the state of vestibular dysfunction during the attack-free periods demonstrated the signs of latent vestibular dysfunction in 20 (83.3%) patients. The results of the study provide additional information on the prevalence of vascular compression of the vestibulocochlear nerve in the patients presenting with recurrent chronic dizziness; moreover, they make it possible to evaluate the state of vestibular function and develop the new diagnostic criteria for vestibular paroxismia.

Adaptation to vestibular disorientation. IV, Responses to angular acceleration and to bilateral caloric stimulation following unilateral caloric habituation.

DOT National Transportation Integrated Search

1967-01-01

The paper provides information that angular acceleration tests of the vestibular system transcend clinical caloric tests in revealing adaptation to angular accelerations as experienced in rotary motions, including flight situations. The caloric test ...

Surgical management of vestibular schwannoma: attempted preservation of hearing and facial function.

PubMed

Youssef, T F; Matter, A; Ahmed, M R

2013-05-01

Vestibular schwannomas are benign tumours which usually originate from the vestibular portion of the VIIIth cranial nerve. Treatment options include observation with serial imaging, stereotactic radiation and microsurgical removal. The goal of surgery was complete eradication of tumour with preservation of hearing and facial nerve function. A retrospective review was undertaken of 24 cases of vestibular schwannoma jointly operated upon by a team of neurosurgeons and otologists at the Suez Canal University Hospital, with assessment of VIIth and VIIIth cranial nerve function, tumour size, and extent of growth. All surgery utilised a retromastoid, suboccipital approach. Complete tumour removal was achieved in 19 patients. Anatomical preservation of the facial nerve was possible in 66.6 per cent of patients. Pre-operative, useful hearing was present in four patients, and preserved in 80 per cent. Cerebrospinal fluid leakage was diagnosed in two (8.3 per cent) patients, who responded to conservative therapy. The retromastoid, suboccipital surgical approach to the skull base can be safely and successfully achieved using a microsurgical technique, with minimal or no damage to neurovascular structures, even for large tumours.

Perception of tilt and ocular torsion of vestibular patients during eccentric rotation.

PubMed

Clément, Gilles; Deguine, Olivier

2010-01-04

Four patients following unilateral vestibular loss and four patients complaining of otolith-dependent vertigo were tested during eccentric yaw rotation generating 1 x g centripetal acceleration directed along the interaural axis. Perception of body tilt in roll and in pitch was recorded in darkness using a somatosensory plate that the subjects maintained parallel to the perceived horizon. Ocular torsion was recorded by a video camera. Unilateral vestibular-defective patients underestimated the magnitude of the roll tilt and had a smaller torsion when the centrifugal force was towards the operated ear compared to the intact ear and healthy subjects. Patients with otolithic-dependent vertigo overestimated the magnitude of roll tilt in both directions of eccentric rotation relative to healthy subjects, and their ocular torsion was smaller than in healthy subjects. Eccentric rotation is a promising tool for the evaluation of vestibular dysfunction in patients. Eye torsion and perception of tilt during this stimulation are objective and subjective measurements, which could be used to determine alterations in spatial processing in the CNS.

Modulated discharge of Purkinje and stellate cells persists after unilateral loss of vestibular primary afferent mossy fibers in mice

PubMed Central

Yakhnitsa, V.

2013-01-01

Cerebellar Purkinje cells are excited by two afferent pathways: climbing and mossy fibers. Climbing fibers evoke large “complex spikes” (CSs) that discharge at low frequencies. Mossy fibers synapse on granule cells whose parallel fibers excite Purkinje cells and may contribute to the genesis of “simple spikes” (SSs). Both afferent systems convey vestibular information to folia 9c–10. After making a unilateral labyrinthectomy (UL) in mice, we tested how the discharge of CSs and SSs was changed by the loss of primary vestibular afferent mossy fibers during sinusoidal roll tilt. We recorded from cells identified by juxtacellular neurobiotin labeling. The UL preferentially reduced vestibular modulation of CSs and SSs in folia 8–10 contralateral to the UL. The effects of a UL on Purkinje cell discharge were similar in folia 9c–10, to which vestibular primary afferents project, and in folia 8–9a, to which they do not project, suggesting that vestibular primary afferent mossy fibers were not responsible for the UL-induced alteration of SS discharge. UL also induced reduced vestibular modulation of stellate cell discharge contralateral to the UL. We attribute the decreased modulation to reduced vestibular modulation of climbing fibers. In summary, climbing fibers modulate CSs directly and SSs indirectly through activation of stellate cells. Whereas vestibular primary afferent mossy fibers cannot account for the modulated discharge of SSs or stellate cells, the nonspecific excitation of Purkinje cells by parallel fibers may set an operating point about which the discharges of SSs are sculpted by climbing fibers. PMID:23966673

Long-Term Facial Nerve Outcomes after Microsurgical Resection of Vestibular Schwannomas in Patients with Preoperative Facial Nerve Palsy.

PubMed

Mooney, Michael A; Hendricks, Benjamin; Sarris, Christina E; Spetzler, Robert F; Almefty, Kaith K; Porter, Randall W

2018-06-01

Objectives  This study aimed at evaluating facial nerve outcomes in vestibular schwannoma patients presenting with preoperative facial nerve palsy. Design  A retrospective review. Setting  Single-institution cohort. Participants  Overall, 368 consecutive patients underwent vestibular schwannoma resection. Patients with prior microsurgery or radiosurgery were excluded. Main Outcome Measures  Incidence, House-Brackmann grade. Results  Of 368 patients, 9 had confirmed preoperative facial nerve dysfunction not caused by prior treatment, for an estimated incidence of 2.4%. Seven of these nine patients had Koos grade 4 tumors. Mean tumor diameter was 3.0 cm (range: 2.1-4.4 cm), and seven of nine tumors were subtotally resected. All nine patients were followed up clinically for ≥ 6 months. Of the six patients with a preoperative House-Brackmann grade of II, two improved to grade I, three were stable, and one patient worsened to grade III. Of the three patients with grade III or worse, all remained stable at last follow-up. Conclusions  Preoperative facial nerve palsy is rare in patients with vestibular schwannoma; it tends to occur in patients with relatively large lesions. Detailed long-term outcomes of facial nerve function after microsurgical resection for these patients have not been reported previously. We followed nine patients and found that eight (89%) of the nine patients had either stable or improved facial nerve outcomes after treatment. Management strategies varied for these patients, including rates of subtotal versus gross-total resection and the use of stereotactic radiosurgery in patients with residual tumor. These results can be used to help counsel patients preoperatively on expected outcomes of facial nerve function after treatment.

Role of the cerebellum and the vestibular apparatus in regulation of orthostatic reflexes in the cat

NASA Technical Reports Server (NTRS)

Doba, N.; Reis, D. J.

1974-01-01

The contribution of the fastigial nucleus and the vestibular nerves (eighth cranial nerves) to the orthostatic reflexes in anesthetized, paralyzed cats was studied. Bilateral lesions of the rostral fastigial nucleus resulted in impairment of the reflex changes in blood pressure, femoral arterial flow, and resistance evoked by head-up tilting to 30 deg or 60 deg. The rostral fastigial nucleus, which might be triggered by the vestibular apparatus, appears to participate in concert with the baroreceptors in the initiation and possibly the maintenance of the orthostatic reflexes.

Probabilistic Tractography of the Cranial Nerves in Vestibular Schwannoma.

PubMed

Zolal, Amir; Juratli, Tareq A; Podlesek, Dino; Rieger, Bernhard; Kitzler, Hagen H; Linn, Jennifer; Schackert, Gabriele; Sobottka, Stephan B

2017-11-01

Multiple recent studies have reported on diffusion tensor-based fiber tracking of cranial nerves in vestibular schwannoma, with conflicting results as to the accuracy of the method and the occurrence of cochlear nerve depiction. Probabilistic nontensor-based tractography might offer advantages in terms of better extraction of directional information from the underlying data in cranial nerves, which are of subvoxel size. Twenty-one patients with large vestibular schwannomas were recruited. The probabilistic tracking was run preoperatively and the position of the potential depictions of the facial and cochlear nerves was estimated postoperatively by 3 independent observers in a blinded fashion. The true position of the nerve was determined intraoperatively by the surgeon. Thereafter, the imaging-based estimated position was compared with the intraoperatively determined position. Tumor size, cystic appearance, and postoperative House-Brackmann score were analyzed with regard to the accuracy of the depiction of the nerves. The probabilistic tracking showed a connection that correlated to the position of the facial nerve in 81% of the cases and to the position of the cochlear nerve in 33% of the cases. Altogether, the resulting depiction did not correspond to the intraoperative position of any of the nerves in 3 cases. In a majority of cases, the position of the facial nerve, but not of the cochlear nerve, could be estimated by evaluation of the probabilistic tracking results. However, false depictions not corresponding to any nerve do occur and cannot be discerned as such from the image only. Copyright © 2017 Elsevier Inc. All rights reserved.

Unilateral blindness with third cranial nerve palsy and abnormal enhancement of extraocular muscles on magnetic resonance imaging of orbit after the ingestion of methanol.

PubMed

Chung, Tae Nyoung; Kim, Sun Wook; Park, Yoo Seok; Park, Incheol

2010-05-01

Methanol is generally known to cause visual impairment and various systemic manifestations. There are a few reported specific findings for methanol intoxication on magnetic resonance imaging (MRI) of the brain. A case is reported of unilateral blindness with third cranial nerve palsy oculus sinister (OS) after the ingestion of methanol. Unilateral damage of the retina and optic nerve were confirmed by fundoscopy, flourescein angiography, visual evoked potential and electroretinogram. The optic nerve and extraocular muscles (superior rectus, medial rectus, inferior rectus and inferior oblique muscle) were enhanced by gadolinium-DTPA on MRI of the orbit. This is the first case report of permanent monocular blindness with confirmed unilateral damage of the retina and optic nerve, combined with third cranial nerve palsy after methanol ingestion.

Stereotactic radiosurgery vs. fractionated radiotherapy for tumor control in vestibular schwannoma patients: a systematic review.

PubMed

Persson, Oscar; Bartek, Jiri; Shalom, Netanel Ben; Wangerid, Theresa; Jakola, Asgeir Store; Förander, Petter

2017-06-01

Repeated controlled studies have revealed that stereotactic radiosurgery is better than microsurgery for patients with vestibular schwannoma (VS) <3 cm in need of intervention. In this systematic review we aimed to compare results from single-fraction stereotactic radiosurgery (SRS) to fractionated stereotactic radiotherapy (FSRT) for patients with VS. We systematically searched MEDLINE, Web of Science, Embase and Cochrane and screened relevant articles for references. Publications from 1995 through 2014 with a minimum of 50 adult (>18 years) patients with unilateral VS, followed for a median of >5 years, were eligible for inclusion. After screening titles and abstracts of the 1094 identified articles and systematically reviewing 98 of these articles, 19 were included. Patients with unilateral VS treated with radiosurgery were compared to patients treated with fractionated stereotactic radiotherapy. No randomized controlled trial (RCT) was identified. None of the identified controlled studies comparing SRS with FSRT were eligible according to the inclusion criteria. Nineteen case series on SRS (n = 17) and FSRT (n = 2) were included in the systematic review. Loss of tumor control necessitating a new VS-targeted intervention was found in an average of 5.0% of the patients treated with SRS and in 4.8% treated with FSRT. Mean deterioration ratio for patients with serviceable hearing before treatment was 49% for SRS and 45% for FSRT, respectively. The risk for facial nerve deterioration was 3.6% for SRS and 11.2% for FSRT and for trigeminal nerve deterioration 6.0% for SRS and 8.4% for FSRT. Since these results were obtained from case series, a regular meta-analysis was not attempted. SRS and FSRT are both noninvasive treatment alternatives for patients with VS with low rates of treatment failure in need of rescue therapy. In this selection of patients, the progression-free survival rates were on the order of 92-100% for both treatment options. There is a lack of high-quality studies comparing radiation therapy alternatives for patients with VS. Finally, 19 articles reported long-term tumor control after SRS, while only 2 articles reported long-term FSRT results, making effect estimates more uncertain for FSRT.

Long-term follow-up studies of Gamma Knife surgery for patients with neurofibromatosis Type 2.

PubMed

Sun, Shibin; Liu, Ali

2014-12-01

The aim of this study was to evaluate long-term clinical outcomes after Gamma Knife surgery (GKS) for patients with neurofibromatosis Type 2 (NF2) and the role of GKS in the management of NF2. From December 1994 through December 2008, a total of 46 patients (21 male, 25 female) with NF2 underwent GKS and follow-up evaluation for at least 5 years at the Gamma Knife Center of the Beijing Neurosurgical Institute. GKS was performed using the Leksell Gamma Knife Models B and C. The mean age of the patients was 30 years (range 13-59 years). A family history of NF2 was found for 9 (20%) patients. The NF2 phenotype was thought to be Wishart for 20 (44%) and Feiling-Gardner for 26 (56%) patients. Among these 46 patients, GKS was performed to treat 195 tumors (73 vestibular schwannomas and 122 other tumors including other schwannomas and meningiomas). For vestibular schwannomas, the mean volume was 5.1 cm(3) (median 3.6 cm(3), range 0.3-27.3 cm(3)), the mean margin dose was 12.9 Gy (range 10-14 Gy), and the mean maximum dose was 27.3 Gy (range 16.2-40 Gy). For other tumors, the mean volume was 1.7 cm(3) (range 0.3-5.5 cm(3)), the mean margin dose was 13.3 Gy (range 11-14 Gy), and the mean maximum dose was 26.0 Gy (range 18.0-30.4 Gy). The median duration of follow-up was 109 months (range 8-195 months). For the 73 vestibular schwannomas that underwent GKS, the latest follow-up MR images demonstrated regression of 30 (41%) tumors, stable size for 31 (43%) tumors, and enlargement of 12 (16%) tumors. The total rate of tumor control for bilateral vestibular schwannomas in patients with NF2 was 84%. Of the 122 other types of tumors that underwent GKS, 103 (85%) showed no tumor enlargement. The rate of serviceable hearing preservation after GKS was 31.9% (15/47). The actuarial rates for hearing preservation at 3 years, 5 years, 10 years, and 15 years were 98%, 93%, 44%, and 17%, respectively. Of the 46 patients, 22 (48%) became completely bilaterally deaf, 17 (37%) retained unilateral serviceable hearing, and 7 (15%) retained bilateral serviceable hearing. The mean history of the disease course was 12 years (range 5-38 years). GKS was confirmed to provide long-term local tumor control for small- to medium-sized vestibular schwannomas and other types of tumors, although vestibular schwannomas in patients with NF2 responded less well than did unilateral sporadic vestibular schwannomas. Phenotype is the most strongly predictive factor of final outcome after GKS for patients with NF2. The risk for loss of hearing is high, whereas the risk for other cranial nerve complications is low.

Modulation of Memory by Vestibular Lesions and Galvanic Vestibular Stimulation

PubMed Central

Smith, Paul F.; Geddes, Lisa H.; Baek, Jean-Ha; Darlington, Cynthia L.; Zheng, Yiwen

2010-01-01

For decades it has been speculated that there is a close association between the vestibular system and spatial memories constructed by areas of the brain such as the hippocampus. While many animal studies have been conducted which support this relationship, only in the last 10 years have detailed quantitative studies been carried out in patients with vestibular disorders. The majority of these studies suggest that complete bilateral vestibular loss results in spatial memory deficits that are not simply due to vestibular reflex dysfunction, while the effects of unilateral vestibular damage are more complex and subtle. Very recently, reports have emerged that sub-threshold, noisy galvanic vestibular stimulation can enhance memory in humans, although this has not been investigated for spatial memory as yet. These studies add to the increasing evidence that suggests a connection between vestibular sensory information and memory in humans. PMID:21173897

Preservation of Facial Nerve Function Repaired by Using Fibrin Glue-Coated Collagen Fleece for a Totally Transected Facial Nerve during Vestibular Schwannoma Surgery

PubMed Central

Choi, Kyung-Sik; Kim, Min-Su; Jang, Sung-Ho

2014-01-01

Recently, the increasing rates of facial nerve preservation after vestibular schwannoma (VS) surgery have been achieved. However, the management of a partially or completely damaged facial nerve remains an important issue. The authors report a patient who was had a good recovery after a facial nerve reconstruction using fibrin glue-coated collagen fleece for a totally transected facial nerve during VS surgery. And, we verifed the anatomical preservation and functional outcome of the facial nerve with postoperative diffusion tensor (DT) imaging facial nerve tractography, electroneurography (ENoG) and House-Brackmann (HB) grade. DT imaging tractography at the 3rd postoperative day revealed preservation of facial nerve. And facial nerve degeneration ratio was 94.1% at 7th postoperative day ENoG. At postoperative 3 months and 1 year follow-up examination with DT imaging facial nerve tractography and ENoG, good results for facial nerve function were observed. PMID:25024825

Observations on the elicitation of secondary and inverted primary nystagmus from the cat by unilateral caloric irrigation.

DOT National Transportation Integrated Search

1963-02-01

Vestibular stimulation by repeated unilateral caloric irrigation of cats occasioned the appearance of secondary, tertiary, and inverted primary nystagmus in some animals. These inverse responses were recorded with stimulus temperatures of 5, 23.5, an...

A long-lasting improvement of tactile extinction after galvanic vestibular stimulation: two Sham-stimulation controlled case studies.

PubMed

Kerkhoff, Georg; Hildebrandt, Helmut; Reinhart, Stefan; Kardinal, Mareike; Dimova, Violeta; Utz, Kathrin S

2011-01-01

Sensory extinction is frequent and often persistent after brain damage. Previous studies have shown the transient influence of sensory stimulation on tactile extinction. In the present two case studies we investigated whether subliminal galvanic vestibular stimulation (GVS) modulates tactile extinction. GVS induces polarity-specific changes in cerebral excitability in the vestibular cortices and adjacent cortical areas in the temporo-parietal cortex via polarization of the vestibular nerves. Two patients (DL, CJ) with left-sided tactile extinction due to chronic (5 vs. 6 (1/2) years lesion age) right-hemisphere lesions (right fronto-parietal in DL, right frontal and discrete parietal in CJ) were examined. Both showed normal tactile sensitivity to light touch and yielded 90-100% correct identifications in unilateral tactile stimulations for both hands. In Baseline investigations without GVS and Sham-GVS both showed stable left-sided tactile extinction rates of 40-55% (DL) and 49-72% (CJ). In contrast, one session of right-cathodal GVS (intensity: 0.6 mA, duration: 20 min) permanently improved tactile identification of identical stimuli, while a second session with left-cathodal GVS significantly reduced left-sided extinction rates for different stimuli in DL. Patient CJ's left-sided tactile extinction was significantly improved by left-cathodal GVS (0.5 mA, 20 min) for different stimuli, while right-cathodal GVS induced a significant reduction for identical materials. In contrast, Sham-stimulation was ineffective. Improvements remained stable for at least 1 year (DL) resp. 3 weeks (CJ). Control experiments ruled out improvements in tactile extinction merely by retesting. In conclusion, chronic tactile extinction may be permanently improved by GVS in a polarity-specific way. Copyright © 2010 Elsevier Ltd. All rights reserved.

Vestibular activation of sympathetic nerve activity

NASA Technical Reports Server (NTRS)

Ray, C. A.; Carter, J. R.

2003-01-01

AIM: The vestibulosympathetic reflex refers to sympathetic nerve activation by the vestibular system. Animal studies indicate that the vestibular system assists in blood pressure regulation during orthostasis. Although human studies clearly demonstrate activation of muscle sympathetic nerve activity (MSNA) during engagement of the otolith organs, the role of the vestibulosympathetic reflex in maintaining blood pressure during orthostasis is not well-established. Examination of the vestibulosympathetic reflex with other cardiovascular reflexes indicates that it is a powerful and independent reflex. Ageing, which is associated with an increased risk for orthostatic hypotension, attenuates the vestibulosympathetic reflex. The attenuated reflex is associated with a reduction in arterial pressure. CONCLUSION: These findings suggest that the vestibulosympathetic reflex assists in blood pressure regulation in humans, but future studies examining this reflex in other orthostatically intolerant populations are necessary to address this hypothesis.

Neuronal detection thresholds during vestibular compensation: contributions of response variability and sensory substitution.

PubMed

Jamali, Mohsen; Mitchell, Diana E; Dale, Alexis; Carriot, Jerome; Sadeghi, Soroush G; Cullen, Kathleen E

2014-04-01

The vestibular system is responsible for processing self-motion, allowing normal subjects to discriminate the direction of rotational movements as slow as 1-2 deg s(-1). After unilateral vestibular injury patients' direction-discrimination thresholds worsen to ∼20 deg s(-1), and despite some improvement thresholds remain substantially elevated following compensation. To date, however, the underlying neural mechanisms of this recovery have not been addressed. Here, we recorded from first-order central neurons in the macaque monkey that provide vestibular information to higher brain areas for self-motion perception. Immediately following unilateral labyrinthectomy, neuronal detection thresholds increased by more than two-fold (from 14 to 30 deg s(-1)). While thresholds showed slight improvement by week 3 (25 deg s(-1)), they never recovered to control values - a trend mirroring the time course of perceptual thresholds in patients. We further discovered that changes in neuronal response variability paralleled changes in sensitivity for vestibular stimulation during compensation, thereby causing detection thresholds to remain elevated over time. However, we found that in a subset of neurons, the emergence of neck proprioceptive responses combined with residual vestibular modulation during head-on-body motion led to better neuronal detection thresholds. Taken together, our results emphasize that increases in response variability to vestibular inputs ultimately constrain neural thresholds and provide evidence that sensory substitution with extravestibular (i.e. proprioceptive) inputs at the first central stage of vestibular processing is a neural substrate for improvements in self-motion perception following vestibular loss. Thus, our results provide a neural correlate for the patient benefits provided by rehabilitative strategies that take advantage of the convergence of these multisensory cues.

Neuronal detection thresholds during vestibular compensation: contributions of response variability and sensory substitution

PubMed Central

Jamali, Mohsen; Mitchell, Diana E; Dale, Alexis; Carriot, Jerome; Sadeghi, Soroush G; Cullen, Kathleen E

2014-01-01

The vestibular system is responsible for processing self-motion, allowing normal subjects to discriminate the direction of rotational movements as slow as 1–2 deg s−1. After unilateral vestibular injury patients’ direction–discrimination thresholds worsen to ∼20 deg s−1, and despite some improvement thresholds remain substantially elevated following compensation. To date, however, the underlying neural mechanisms of this recovery have not been addressed. Here, we recorded from first-order central neurons in the macaque monkey that provide vestibular information to higher brain areas for self-motion perception. Immediately following unilateral labyrinthectomy, neuronal detection thresholds increased by more than two-fold (from 14 to 30 deg s−1). While thresholds showed slight improvement by week 3 (25 deg s−1), they never recovered to control values – a trend mirroring the time course of perceptual thresholds in patients. We further discovered that changes in neuronal response variability paralleled changes in sensitivity for vestibular stimulation during compensation, thereby causing detection thresholds to remain elevated over time. However, we found that in a subset of neurons, the emergence of neck proprioceptive responses combined with residual vestibular modulation during head-on-body motion led to better neuronal detection thresholds. Taken together, our results emphasize that increases in response variability to vestibular inputs ultimately constrain neural thresholds and provide evidence that sensory substitution with extravestibular (i.e. proprioceptive) inputs at the first central stage of vestibular processing is a neural substrate for improvements in self-motion perception following vestibular loss. Thus, our results provide a neural correlate for the patient benefits provided by rehabilitative strategies that take advantage of the convergence of these multisensory cues. PMID:24366259

Characteristics of vestibular evoked myogenic potentials in children with enlarged vestibular aqueduct.

PubMed

Zhou, Guangwei; Gopen, Quinton

2011-01-01

To explore the characteristics of vestibular evoked myogenic potential (VEMP) in children with enlarged vestibular aqueduct (EVA) and to determine the diagnostic value of VEMP testing for this particular inner ear structural anomaly. Retrospective cohort study in a pediatric tertiary care facility. A total of 25 pediatric cases (37 ears) of EVA were identified with complete records, including otologic evaluation, CT scan of the temporal bone, and audiologic assessment. Results of audiometry, tympanometry, and VEMP testing were analyzed. Hearing loss was found in 97% (36/37) of the ears with EVA. Airbone gaps (conductive components) were found in all hearing losses with normal middle ear pressure and mobility. Abnormally low threshold VEMP responses were found in 92% (34/37) of the ears with EVA. VEMP responses were absent unilaterally in three EVA patients who had vestibular complaints. No clear correlation was found between the size of EVA and the audiologic findings. The presence of airbone gaps in children with EVA was found without apparent middle ear pathology. Characteristics of VEMP in EVA were lower thresholds and higher amplitudes despite of the presence of airbone gaps. The abnormally low threshold VEMP responses suggested a "third" window effect in the pathologic condition of EVA. Unilateral absence of VEMP may implicate peripheral vestibular impairment. The findings from our study are helpful in clinical evaluation of young children who usually give limited and ambiguous input regarding their hearing and vestibular problems.

Ultrastructural localization of ChAT-like immunoreactivity in the human vestibular periphery.

PubMed

Kong, W J; Hussl, B; Thumfart, W F; Schrott-Fischer, A

1998-05-01

Acetylcholine (ACh) has long been considered a neurotransmitter candidate in the efferent vestibular system of mammals. Recently, choline acetyltransferase (ChAT), the synthesizing enzyme for ACh, was immunocytochemically localized in all five end-organs of the rat vestibule (Kong et al. (1994) Hear. Res. 75, 192-200). However, there is little information in the literature concerning the cholinergic innervation in the vestibular periphery of man. In the present study the ultrastructural localization of the ChAT-like immunoreactivity in the human vestibular periphery was investigated in order to reveal the cholinergic innervation in the human vestibular end-organs. A modified method of pre-embedding immunoelectron microscopy was applied. It was found that the ChAT-like immunoreactivity was located in the bouton-type vesiculated nerve terminals in the vestibular neurosensory epithelia of man. These ChAT-like immunostained nerve terminals make synaptic contacts either with afferent chalices surrounding type I vestibular sensory hair cells, or with type II vestibular sensory hair cells. These results show that the ChAT-like immunoreactivity in the human vestibular periphery is confined to the efferent vestibular system. The ChAT-containing efferents innervate both type I hair cells and type II hair cells, making postsynaptic and presynaptic contacts, respectively. This study presents evidence that ACh is a neurotransmitter candidate in the efferent vestibular system of man.

[Air conducted ocular VEMP: II. First clinical investigations].

PubMed

Walther, L E; Schaaf, H; Sommer, D; Hörmann, K

2011-10-01

Vestibular-evoked myogenic potentials (VEMP) are widely used to assess vestibular function. Air conducted (AC) cervical VEMP (cVEMP) reflect sacculus and inferior vestibular nerve function. Ocular VEMP (oVEMP) however has been hardly examined up to now. In recent studies it has been assumed that AC oVEMP probably reflects superior vestibular nerve function. The aim of this pilot study was to evaluate clinical application of the AC oVEMP. AC oVEMP were recorded in patients with peripheral vestibular disorders (n=21). In addition thermal irritation and head impulse test were performed and AC cVEMP were recorded. For intense AC-sound stimulation tone bursts (500 Hz) with 100 dB nHL were used. In peripheral vestibular disorders AC oVEMP and AC cVEMP could be classified into: • type 1 (inferior vestibular neuritis) with loss of AC oVEMP but normal AC cVEMP, • type 2, probable type of superior vestibular neuritis, showing present AC cVEMP but loss of AC oVEMP, • type 3, probable complete vestibular neuritis, without AC oVEMP and AC cVEMP. AC oVEMP may be used as an appropriate test for clinical investigation in patients with vestibular disorders. AC oVEMP is an additional, essential test for assessing otolith function beside AC cVEMP. Further vestibular test are necessary for precise clinical interpretation. © Georg Thieme Verlag KG Stuttgart · New York.

Hyperventilation-induced nystagmus in a large series of vestibular patients.

PubMed

Califano, L; Melillo, M G; Vassallo, A; Mazzone, S

2011-02-01

The Hyperventilation Test is widely used in the "bed-side examination" of vestibular patients. It can either activate a latent nystagmus in central or peripheral vestibular diseases or it can interact with a spontaneous nystagmus, by reducing it or increasing it. Aims of this study were to determine the incidence, patterns and temporal characteristics of Hyperventilation-induced nystagmus in patients suffering from vestibular diseases, as well as its contribution to the differential diagnosis between vestibular neuritis and neuroma of the 8(th) cranial nerve, and its behaviour in some central vestibular diseases. The present study includes 1202 patients featuring, at vestibular examination, at least one sign of vestibular system disorders or patients diagnosed with a "Migraine-related vertigo" or "Chronic subjective dizziness". The overall incidence of Hyperventilation-induced nystagmus was 21.9%. It was detected more frequently in retrocochlear vestibular diseases rather than in end-organ vestibular diseases: 5.3% in Paroxysmal Positional Vertigo, 37.1% in Menière's disease, 37.6% in compensated vestibular neuritis, 77.2% in acute vestibular neuritis and 91.7% in neuroma of the 8(th) cranial nerve. In acute vestibular neuritis, three HVIN patterns were observed: Paretic pattern: temporary enhancement of the spontaneous nystagmus; Excitatory pattern: temporary inhibition of the spontaneous nystagmus; Strong excitatory pattern: temporary inversion of the spontaneous nystagmus. Excitatory patterns proved to be time-dependent in that they disappeared and were replaced by the paretic pattern over a period of maximum 18 days since the beginning of the disorder. In acoustic neuroma, Hyperventilation-induced nystagmus was frequently observed (91.7%), either in the form of an excitatory pattern (fast phases towards the affected site) or in the form of a paretic pattern (fast phases towards the healthy side). The direction of the nystagmus is only partially related to tumour size, whereas other mechanisms, such as demyelination or a break in nerve fibres, might have an important role in triggering the situation. Hyperventilation-induced nystagmus has frequently been detected in cases of demyelinating diseases and in cerebellar diseases: in multiple sclerosis, hyperventilation inhibits a central type of spontaneous nystagmus or evokes nystagmus in 75% of patients; in cerebellar diseases, hyperventilation evokes or enhances a central spontaneous nystagmus in 72.7% of patients. In conclusion the Hyperventilation Test can provide patterns of oculomotor responses that indicate a diagnostic investigation through cerebral magnetic resonance imaging enhanced by gadolinium, upon suspicion of neuroma of the 8(th) cranial nerve or of a central disease. In our opinion, however, Hyperventilation-induced nystagmus always needs to be viewed within the more general context of a complete examination of the vestibular and acoustic system.

Long-term potentiation and depression after unilateral labyrinthectomy in the medial vestibular nucleus of rats.

PubMed

Pettorossi, Vito Enrico; Dutia, Mayank; Frondaroli, Adele; Dieni, Cristina; Grassi, Silvarosa

2003-01-01

We previously demonstrated in rat brainstem slices that high-frequency stimulation (HFS) of the vestibular afferents induces long-term potentiation (LTP) in the ventral part (Vp) of the medial vestibular nucleus (MVN) and long-term depression (LTD) in the dorsal part (Dp). Both LTP and LTD depend on N-methyl-D-aspartate receptor activation, which increases synaptic efficacy; however, in the Dp, LTP reverses to LTD because of the activation of gamma-aminobutyric acid-ergic neurons. Here we show that the probability of inducing long-term effects in the MVN of rat brainstem slices is altered after unilateral labyrinthectomy (UL). In fact, LTP occurs less frequently in the ventral contra-lesional side compared with sham-operated rats. In the dorsal ipsi-lesional side, LTD is reduced and LTP enhanced, while the opposite occurs in the dorsal contra-lesional side. These changes in synaptic plasticity may be useful for re-balancing the tonic discharge of the MVN of the two sides during vestibular compensation, and for enhancing the dynamic responses of the deafferented MVN neurons in the long term.

The effects of hyperventilation on postural control mechanisms.

PubMed

Sakellari, V; Bronstein, A M; Corna, S; Hammon, C A; Jones, S; Wolsley, C J

1997-09-01

The effect of hyperventilation on postural balance was investigated. Voluntary hyperventilation increased body sway in normal subjects, particularly in the sagittal plane. The possibility that this hyperventilation-induced unsteadiness is due to interference with lower limb somatosensory input, vestibular reflexes or cerebellar function was assessed. (i) The effect of hyperventilation on peripheral compound sensory action potentials (SAPs) and somatosensory evoked potentials (SEPs) (recorded centrally, from the scalp) elicited by electrical stimulation of the sural nerve was measured in six normal adults. A reduction in the scalp SEP amplitude and an increase in the peripheral SAP amplitude were observed during hyperventilation, which reversed during the recovery period. These changes indicate increased peripheral neural excitability which could lead to a higher level of ectopic activity; the latter would interfere with central reception of peripheral input. (ii) The click-evoked vestibulo-collic reflex was recorded to study the effect of hyperventilation on vestibulo-spinal activity. EMG recordings from both sternocleidomastoid muscles of six healthy subjects were made in response to loud clicks presented to either ear. Neither the amplitude nor the latency of the response were altered significantly by hyperventilation. (iii) Eye-movement recordings were obtained in the six normal subjects to assess the effect of hyperventilation on the vestibulo-ocular reflex and its visual suppression, the latter being a function largely mediated by the cerebellum; no changes were detected. (iv) Three-dimensional eye-movement recordings and body-sway measurements were obtained in six patients with longstanding unilateral vestibular loss in order to evaluate if hyperventilation disrupts vestibular compensation. In all patients, a horizontal nystagmus either appeared or was significantly enhanced for > or = 60 s after voluntary hyperventilation. Sway was also enhanced by hyperventilation in these patients, particularly in the frontal plane. This study suggests that hyperventilation disrupts mechanisms mediating vestibular compensation. The increase in sway may be, at least partly, mediated by deranged peripheral and central somatosensory signals from the lower limbs. Hyperventilation seems to spare vestibular reflex activity and cerebellar-mediated eye movements.

Psychological symptoms and spatial orientation during the first 3 months after acute unilateral vestibular lesion.

PubMed

Gómez-Alvarez, Fatima B; Jáuregui-Renaud, Kathrine

2011-02-01

We undertook this study to assess the correlation between the results of simple tests of spatial orientation and the occurrence of common psychological symptoms during the first 3 months after an acute, unilateral, peripheral, vestibular lesion. Ten vestibular patients were selected and accepted to participate in the study. During a 3-month follow-up, we recorded the static visual vertical (VV), the estimation error of reorientation in the yaw plane and the responses to a standardized questionnaire of balance symptoms, the Dizziness Handicap Inventory (DHI), the depersonalization/derealization inventory by Cox and Swinson (DD), the Dissociative Experiences Scale (DES), the 12-item General Health Questionnaire (GHQ-12), the Zung Instrument for Anxiety Disorders and the Hamilton Depression Rating Scale. At week 1, all patients showed a VV >2° and failed to reorient themselves effectively. They reported several balance symptoms and handicap as well as DD symptoms, including attention/concentration difficulties; 80% of the patients had a Hamilton score ≥8. At this time the balance symptom score correlated with the DHI. After 3 months, all scores decreased. Multiple regression analysis of the differences from baseline showed that the DD score difference was related to the difference on the balance score, the reorientation error and the DHI score (p <0.01). No other linear relationships were observed (p >0.5). During the acute phase of a unilateral, peripheral, vestibular lesion, patients may show poor spatial orientation concurrent with DD symptoms including attention/concentration difficulties, and somatic depression symptoms. After vestibular rehabilitation, DD symptoms decrease as the spatial orientation improves, even if somatic symptoms of depression persist. Copyright © 2011 IMSS. Published by Elsevier Inc. All rights reserved.

The mixed blessing of treating symptoms in acute vestibular failure--evidence from a 4-aminopyridine experiment.

PubMed

Beck, Roswitha; Günther, Lisa; Xiong, Guoming; Potschka, Heidrun; Böning, Guido; Bartenstein, Peter; Brandt, Thomas; Jahn, Klaus; Dieterich, Marianne; Strupp, Michael; la Fougère, Christian; Zwergal, Andreas

2014-11-01

Early symptomatic treatment of acute unilateral vestibulopathy is thought to impede the course of ensuing central vestibular compensation (VC). Despite the great clinical importance of this hypothesis there is no experimental evidence of its validity. The present study addressed this question by investigating the direct effect of 4-aminopyridine (4-AP) on ocular motor and postural symptoms in acute unilateral vestibulopathy as well as its long-term consequences for VC in a rat model of chemical unilateral labyrinthectomy (UL). After UL, one group of Sprague-Dawley rats was treated with 4-AP p.o. (1mg/kg/day), another with 0.9% NaCl solution p.o. for 3days. Behavioural testing for symptoms of vestibular tone imbalance was done 1day before and 1, 2, 3, 5, 7, 9, 15, 21, and 30days after UL. In addition, sequential whole-brain [(18)F]-FDG-μPET was performed before and 1, 3, 7, 15, and 30days after UL to examine and visualize 4-AP-induced modulation of VC. Administration of 4-AP on days 1-3 significantly improved postural imbalance 2h after administration compared to that in controls. This effect was only transient. Remarkably, the 4-AP group had a prolonged and impaired course of postural compensation compared to that of controls. The μPET revealed a significant increase of regional cerebral glucose metabolism (rCGM) in the vestibulocerebellum 2h after administration of 4-AP. However, the 4-AP group exhibited a persistent asymmetry of rCGM after day 3 in the vestibular nuclei and posterolateral thalami. In conclusion, this study confirms the hypothesis that early pharmacological abatement of vestibular symptoms impedes VC. Copyright © 2014 Elsevier Inc. All rights reserved.

Convergence of limb, visceral, and vertical semicircular canal or otolith inputs onto vestibular nucleus neurons

NASA Technical Reports Server (NTRS)

Jian, B. J.; Shintani, T.; Emanuel, B. A.; Yates, B. J.

2002-01-01

The major goal of this study was to determine the patterns of convergence of non-labyrinthine inputs from the limbs and viscera onto vestibular nucleus neurons receiving signals from vertical semicircular canals or otolith organs. A secondary aim was to ascertain whether the effects of non-labyrinthine inputs on the activity of vestibular nucleus neurons is affected by bilateral peripheral vestibular lesions. The majority (72%) of vestibular nucleus neurons in labyrinth-intact animals whose firing was modulated by vertical rotations responded to electrical stimulation of limb and/or visceral nerves. The activity of even more vestibular nucleus neurons (93%) was affected by limb or visceral nerve stimulation in chronically labyrinthectomized preparations. Some neurons received non-labyrinthine inputs from a variety of peripheral sources, including antagonist muscles acting at the same joint, whereas others received inputs from more limited sources. There was no apparent relationship between the spatial and dynamic properties of a neuron's responses to tilts in vertical planes and the non-labyrinthine inputs that it received. These data suggest that non-labyrinthine inputs elicited during movement will modulate the processing of information by the central vestibular system, and may contribute to the recovery of spontaneous activity of vestibular nucleus neurons following peripheral vestibular lesions. Furthermore, some vestibular nucleus neurons with non-labyrinthine inputs may be activated only during particular behaviors that elicit a specific combination of limb and visceral inputs.

Convergence of limb, visceral, and vertical semicircular canal or otolith inputs onto vestibular nucleus neurons.

PubMed

Jian, B J; Shintani, T; Emanuel, B A; Yates, B J

2002-05-01

The major goal of this study was to determine the patterns of convergence of non-labyrinthine inputs from the limbs and viscera onto vestibular nucleus neurons receiving signals from vertical semicircular canals or otolith organs. A secondary aim was to ascertain whether the effects of non-labyrinthine inputs on the activity of vestibular nucleus neurons is affected by bilateral peripheral vestibular lesions. The majority (72%) of vestibular nucleus neurons in labyrinth-intact animals whose firing was modulated by vertical rotations responded to electrical stimulation of limb and/or visceral nerves. The activity of even more vestibular nucleus neurons (93%) was affected by limb or visceral nerve stimulation in chronically labyrinthectomized preparations. Some neurons received non-labyrinthine inputs from a variety of peripheral sources, including antagonist muscles acting at the same joint, whereas others received inputs from more limited sources. There was no apparent relationship between the spatial and dynamic properties of a neuron's responses to tilts in vertical planes and the non-labyrinthine inputs that it received. These data suggest that non-labyrinthine inputs elicited during movement will modulate the processing of information by the central vestibular system, and may contribute to the recovery of spontaneous activity of vestibular nucleus neurons following peripheral vestibular lesions. Furthermore, some vestibular nucleus neurons with non-labyrinthine inputs may be activated only during particular behaviors that elicit a specific combination of limb and visceral inputs.

One-shot, low-dosage intratympanic gentamicin for Ménière's disease: Clinical, posturographic and vestibular test findings.

PubMed

Daneshi, Ahmad; Jahandideh, Hesam; Pousti, Seyed Behzad; Mohammadi, Shabahang

2014-01-01

Ménière's disease has been remained as a difficult therapeutic challenge. The present study aimed to determine the effects of one-shot low-dosage intratympanic gentamicin on vertigo control, auditory outcomes and findings of computerized dynamic posturography and vestibular evoked myogenic potentials in patients with unilateral Ménière's disease. In a prospective clinical study, 30 patients with unilateral Ménière's disease were treated with one-shot intratympanic injection of 20 milligrams gentamicin. Main outcome measures included clinical, audiometric, postural and vestibular outcomes evaluated 1 and 9 months after the treatment. Mean vertigo attacks frequency, pure tone average threshold and functional level scale significantly decreased after the treatment (P < 0.05). Effective vertigo control (class A and B) obtained in 95.8% of the patients. In total, 75% of patients reported decrease in both aural fullness and tinnitus. Vestibular evoked myogenic potentials became absent in all the patients but four of them. Posturographic scores were improved after the treatment. One-shot low-dosage gentamicin was effective in controlling vertigo attacks in Ménière's disease and has useful effects on aural fullness and tinnitus of patients as well. Postural and vestibular tests only have adjunctive role for monitoring therapeutic responses in intratympanic gentamicin-therapy.

[The clinical values of VEMP in the diagnosis of vestibular nerve impairment in the patients with type 2 diabetes mellitus].

PubMed

Su, Juan; Zhang, Jing; Wang, Mingxin; Zhou, Huifang

2015-12-01

To explore the values of vestibular evoked myogenic potential (VEMP) in the diagnosis of vestibular nerve impairment in type 2 diabetes mellitus patients. Forty-two cases (84 ears) of diabetes mellitus patients and 42 cases (84 ears) normal subjects as the control group were enrolled from 2014 to 2015.Both the patients and normal subjects underwent conventional air-conducted ocular vestibular evoked myogenic potential (oVEMP) and cervical vestibular evoked myogenic potential (cVEMP) in bilateral ears.The results were compared between the patients and normal subjects. A commercially available software package, SPSS19.0, was used for statistical analysis. In 84 ears of the normal subjects, oVEMP was present in 70 ears, the educible rate was 83.3% (70/84). cVEMP was present in 74 ears, and the educible rate was 88.1% (74/84). In 84 ears of the diabetes mellitus patients, oVEMP was present in 49 ears, with the educible rate of 58.3% (49/84). cVEMP was present in 52 ears, with the educible rate of 61.9% (52/84). The educible rate in the control group was significantly higher than the diabetic group (oVEMP: χ(2)=12.71, P<0.05; cVEMP: χ(2)=15.37, P<0.05). In the diabetic group, the mean values of both oVEMP and cVEMP P1, N1 latencies were significantly longer when compared to the control group (P<0.05). No significantly statistical difference was found in oVEMP and cVEMP parameters (threshold, latency interval and amplitude) between groups (P>0.05). Vestibular nerve was impaired in diabetes mellitus patients in some degree. VEMP examinations could be useful in the diagnosis of vestibular nerve impairment in type 2 diabetes mellitus patients.

PubMed Central

CALIFANO, L.; MELILLO, M.G.; VASSALLO, A.; MAZZONE, S.

2011-01-01

SUMMARY The Hyperventilation Test is widely used in the "bed-side examination" of vestibular patients. It can either activate a latent nystagmus in central or peripheral vestibular diseases or it can interact with a spontaneous nystagmus, by reducing it or increasing it. Aims of this study were to determine the incidence, patterns and temporal characteristics of Hyperventilation-induced nystagmus in patients suffering from vestibular diseases, as well as its contribution to the differential diagnosis between vestibular neuritis and neuroma of the 8th cranial nerve, and its behaviour in some central vestibular diseases. The present study includes 1202 patients featuring, at vestibular examination, at least one sign of vestibular system disorders or patients diagnosed with a "Migraine-related vertigo" or "Chronic subjective dizziness". The overall incidence of Hyperventilation-induced nystagmus was 21.9%. It was detected more frequently in retrocochlear vestibular diseases rather than in end-organ vestibular diseases: 5.3% in Paroxysmal Positional Vertigo, 37.1% in Menière's disease, 37.6% in compensated vestibular neuritis, 77.2% in acute vestibular neuritis and 91.7% in neuroma of the 8th cranial nerve. In acute vestibular neuritis, three HVIN patterns were observed: Paretic pattern: temporary enhancement of the spontaneous nystagmus; Excitatory pattern: temporary inhibition of the spontaneous nystagmus; Strong excitatory pattern: temporary inversion of the spontaneous nystagmus. Excitatory patterns proved to be time-dependent in that they disappeared and were replaced by the paretic pattern over a period of maximum 18 days since the beginning of the disorder. In acoustic neuroma, Hyperventilation-induced nystagmus was frequently observed (91.7%), either in the form of an excitatory pattern (fast phases towards the affected site) or in the form of a paretic pattern (fast phases towards the healthy side). The direction of the nystagmus is only partially related to tumour size, whereas other mechanisms, such as demyelination or a break in nerve fibres, might have an important role in triggering the situation. Hyperventilation-induced nystagmus has frequently been detected in cases of demyelinating diseases and in cerebellar diseases: in multiple sclerosis, hyperventilation inhibits a central type of spontaneous nystagmus or evokes nystagmus in 75% of patients; in cerebellar diseases, hyperventilation evokes or enhances a central spontaneous nystagmus in 72.7% of patients. In conclusion the Hyperventilation Test can provide patterns of oculomotor responses that indicate a diagnostic investigation through cerebral magnetic resonance imaging enhanced by gadolinium, upon suspicion of neuroma of the 8th cranial nerve or of a central disease. In our opinion, however, Hyperventilation-induced nystagmus always needs to be viewed within the more general context of a complete examination of the vestibular and acoustic system. PMID:21808459

Altered vesicular glutamate transporter distributions in the mouse cochlear nucleus following cochlear insult

PubMed Central

Heeringa, Amarins N.; Stefanescu, Roxana A.; Raphael, Yehoash; Shore, Susan E.

2015-01-01

Vesicular glutamate transporters 1 and 2 (VGLUT1 and VGLUT2) have distinct distributions in the cochlear nucleus that correspond to the sources of the labeled terminals. VGLUT1 is mainly associated with terminals of auditory nerve fibers, whereas VGLUT2 is mainly associated with glutamatergic terminals deriving from other sources that project to the cochlear nucleus (CN), including somatosensory and vestibular terminals. Previous studies in guinea pig have shown that cochlear damage results in a decrease of VGLUT1-labeled puncta and an increase in VGLUT2-labeled puncta. This indicates cross-modal compensation that is of potential importance in somatic tinnitus. To examine whether this effect is consistent across species and to provide a background for future studies, using transgenesis, the current study examines VGLUT expression profiles upon cochlear insult by intracochlear kanamycin injections in the mouse. Intracochlear kanamycin injections abolished ipsilateral ABR responses in all animals and reduced ipsilateral spiral ganglion neuron densities in animals that were sacrificed after four weeks, but not in animals that were sacrificed after three weeks. In all unilaterally deafened animals, VGLUT1 density was decreased in CN regions that receive auditory nerve fiber terminals, i.e. in the deep layer of the dorsal cochlear nucleus (DCN), in the interstitial region where the auditory nerve enters the CN, and in the magnocellular region of the antero- and posteroventral CN. In contrast, density of VGLUT2 expression was upregulated in the fusiform cell layer of the DCN and in the granule cell lamina, which are known to receive somatosensory and vestibular terminals. These results show that a cochlear insult induces cross-modal compensation in the cochlear nucleus of the mouse, confirming previous findings in guinea pig, and that these changes are not dependent on the occurrence of spiral ganglion neuron degeneration. PMID:26705736

Altered vesicular glutamate transporter distributions in the mouse cochlear nucleus following cochlear insult.

PubMed

Heeringa, A N; Stefanescu, R A; Raphael, Y; Shore, S E

2016-02-19

Vesicular glutamate transporters 1 and 2 (VGLUT1 and VGLUT2) have distinct distributions in the cochlear nucleus that correspond to sources of the labeled terminals. VGLUT1 is mainly associated with terminals of auditory nerve fibers, whereas VGLUT2 is mainly associated with glutamatergic terminals deriving from other sources that project to the cochlear nucleus (CN), including somatosensory and vestibular terminals. Previous studies in guinea pig have shown that cochlear damage results in a decrease of VGLUT1-labeled puncta and an increase in VGLUT2-labeled puncta. This indicates cross-modal compensation that is of potential importance in somatic tinnitus. To examine whether this effect is consistent across species and to provide a background for future studies, using transgenesis, the current study examines VGLUT expression profiles upon cochlear insult by intracochlear kanamycin injections in the mouse. Intracochlear kanamycin injections abolished ipsilateral ABR responses in all animals and reduced ipsilateral spiral ganglion neuron densities in animals that were sacrificed after four weeks, but not in animals that were sacrificed after three weeks. In all unilaterally deafened animals, VGLUT1 density was decreased in CN regions that receive auditory nerve fiber terminals, i.e., in the deep layer of the dorsal cochlear nucleus (DCN), in the interstitial region where the auditory nerve enters the CN, and in the magnocellular region of the antero- and posteroventral CN. In contrast, density of VGLUT2 expression was upregulated in the fusiform cell layer of the DCN and in the granule cell lamina, which are known to receive somatosensory and vestibular terminals. These results show that a cochlear insult induces cross-modal compensation in the cochlear nucleus of the mouse, confirming previous findings in guinea pig, and that these changes are not dependent on the occurrence of spiral ganglion neuron degeneration. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Vestibular Restoration and Adaptation in Vestibular Neuritis and Ramsay Hunt Syndrome With Vertigo.

PubMed

Martin-Sanz, Eduardo; Rueda, Almudena; Esteban-Sanchez, Jonathan; Yanes, Joaquin; Rey-Martinez, Jorge; Sanz-Fernandez, Ricardo

2017-08-01

To evaluate vestibular restoration and the evolution of the compensatory saccades in acute severe inflammatory vestibular nerve paralysis, including vestibular neuritis and Ramsay Hunt syndrome with vertigo. Prospective. Tertiary referral center. Vestibular neuritis (n = 18) and Ramsay Hunt syndrome patients with vertigo (n = 13) were enrolled. After treatment with oral corticosteroids, patients were followed up for 6 months. Functional recovery of the facial nerve was scored according to the House-Brackman grading system. Caloric and video head impulse tests were performed in every patient at the time of enrolment. Subsequently, successive video head impulse test (vHIT) exploration was performed at the 1, 3, and 6-month follow-up. Eighteen patients with vestibular neuritis and 13 with Ramsay Hunt syndrome and associated vertigo were included. Vestibular function was significantly worse in patients with Ramsay Hunt syndrome than in those with vestibular neuritis. Similar compensatory saccades velocity and latency values were observed in both groups, in both the caloric and initial vHIT tests. Successive vHIT results showed a significantly higher vestibulo-ocular reflex gain recovery in vestibular neuritis patients than in Ramsay Hunt syndrome patients. A significantly faster reduction in the latency, velocity, and organization of the compensatory saccades was observed in neuritis than in Ramsay Hunt syndrome patients. In addition to the recovery of the vestibulo-ocular reflex, the reduction of latency, velocity and the organization of compensatory saccades play a role in vestibular compensation.

Plasticity of spontaneous excitatory and inhibitory synaptic activity in morphologically defined vestibular nuclei neurons during early vestibular compensation

PubMed Central

Shao, Mei; Hirsch, June C.

2012-01-01

After unilateral peripheral vestibular lesions, the brain plasticity underlying early recovery from the static symptoms is not fully understood. Principal cells of the chick tangential nucleus offer a subset of morphologically defined vestibular nuclei neurons to study functional changes after vestibular lesions. Chickens show posture and balance deficits immediately after unilateral vestibular ganglionectomy (UVG), but by 3 days most subjects begin to recover, although some remain uncompensated. With the use of whole cell voltage-clamp, spontaneous excitatory and inhibitory postsynaptic currents (sEPSCs and sIPSCs) and miniature excitatory and inhibitory postsynaptic currents (mEPSCs and mIPSCs) were recorded from principal cells in brain slices 1 and 3 days after UVG. One day after UVG, sEPSC frequency increased on the lesion side and remained elevated at 3 days in uncompensated chickens only. Also by 3 days, sIPSC frequency increased on the lesion side in all operated chickens due to major increases in GABAergic events. Significant change also occurred in decay time of the events. To determine whether fluctuations in frequency and kinetics influenced overall excitatory or inhibitory synaptic drive, synaptic charge transfer was calculated. Principal cells showed significant increase in excitatory synaptic charge transfer only on the lesion side of uncompensated chickens. Thus compensation continues when synaptic charge transfer is in balance bilaterally. Furthermore, excessive excitatory drive in principal cells on the lesion side may prevent vestibular compensation. Altogether, this work is important for it defines the time course and excitatory and inhibitory nature of changing spontaneous synaptic inputs to a morphologically defined subset of vestibular nuclei neurons during critical early stages of recovery after UVG. PMID:21957228

Adjustment of the dynamic weight distribution as a sensitive parameter for diagnosis of postural alteration in a rodent model of vestibular deficit

PubMed Central

Tighilet, Brahim; Péricat, David; Frelat, Alais; Cazals, Yves; Rastoldo, Guillaume; Boyer, Florent; Dumas, Olivier

2017-01-01

Vestibular disorders, by inducing significant posturo-locomotor and cognitive disorders, can significantly impair the most basic tasks of everyday life. Their precise diagnosis is essential to implement appropriate therapeutic countermeasures. Monitoring their evolution is also very important to validate or, on the contrary, to adapt the undertaken therapeutic actions. To date, the diagnosis methods of posturo-locomotor impairments are restricted to examinations that most often lack sensitivity and precision. In the present work we studied the alterations of the dynamic weight distribution in a rodent model of sudden and complete unilateral vestibular loss. We used a system of force sensors connected to a data analysis system to quantify in real time and in an automated way the weight bearing of the animal on the ground. We show here that sudden, unilateral, complete and permanent loss of the vestibular inputs causes a severe alteration of the dynamic ground weight distribution of vestibulo lesioned rodents. Characteristics of alterations in the dynamic weight distribution vary over time and follow the sequence of appearance and disappearance of the various symptoms that compose the vestibular syndrome. This study reveals for the first time that dynamic weight bearing is a very sensitive parameter for evaluating posturo-locomotor function impairment. Associated with more classical vestibular examinations, this paradigm can considerably enrich the methods for assessing and monitoring vestibular disorders. Systematic application of this type of evaluation to the dizzy or unstable patient could improve the detection of vestibular deficits and allow predicting better their impact on posture and walk. Thus it could also allow a better follow-up of the therapeutic approaches for rehabilitating gait and balance. PMID:29112981

Adjustment of the dynamic weight distribution as a sensitive parameter for diagnosis of postural alteration in a rodent model of vestibular deficit.

PubMed

Tighilet, Brahim; Péricat, David; Frelat, Alais; Cazals, Yves; Rastoldo, Guillaume; Boyer, Florent; Dumas, Olivier; Chabbert, Christian

2017-01-01

Vestibular disorders, by inducing significant posturo-locomotor and cognitive disorders, can significantly impair the most basic tasks of everyday life. Their precise diagnosis is essential to implement appropriate therapeutic countermeasures. Monitoring their evolution is also very important to validate or, on the contrary, to adapt the undertaken therapeutic actions. To date, the diagnosis methods of posturo-locomotor impairments are restricted to examinations that most often lack sensitivity and precision. In the present work we studied the alterations of the dynamic weight distribution in a rodent model of sudden and complete unilateral vestibular loss. We used a system of force sensors connected to a data analysis system to quantify in real time and in an automated way the weight bearing of the animal on the ground. We show here that sudden, unilateral, complete and permanent loss of the vestibular inputs causes a severe alteration of the dynamic ground weight distribution of vestibulo lesioned rodents. Characteristics of alterations in the dynamic weight distribution vary over time and follow the sequence of appearance and disappearance of the various symptoms that compose the vestibular syndrome. This study reveals for the first time that dynamic weight bearing is a very sensitive parameter for evaluating posturo-locomotor function impairment. Associated with more classical vestibular examinations, this paradigm can considerably enrich the methods for assessing and monitoring vestibular disorders. Systematic application of this type of evaluation to the dizzy or unstable patient could improve the detection of vestibular deficits and allow predicting better their impact on posture and walk. Thus it could also allow a better follow-up of the therapeutic approaches for rehabilitating gait and balance.

A Multi-channel Semicircular Canal Neural Prosthesis Using Electrical Stimulation to Restore 3D Vestibular Sensation

PubMed Central

Della Santina, Charles C.; Migliaccio, Americo A.; Patel, Amit H.

2009-01-01

Bilateral loss of vestibular sensation can be disabling. Those afflicted suffer illusory visual field movement during head movements, chronic disequilibrium and postural instability due to failure of vestibulo-ocular and vestibulo-spinal reflexes. A neural prosthesis that emulates the normal transduction of head rotation by semicircular canals could significantly improve quality of life for these patients. Like the 3 semicircular canals in a normal ear, such a device should at least transduce 3 orthogonal (or linearly separable) components of head rotation into activity on corresponding ampullary branches of the vestibular nerve. We describe the design, circuit performance and in vivo application of a head-mounted, semi-implantable multi-channel vestibular prosthesis that encodes head movement in 3 dimensions as pulse-frequency-modulated electrical stimulation of 3 or more ampullary nerves. In chinchillas treated with intratympanic gentamicin to ablate vestibular sensation bilaterally, prosthetic stimuli elicited a partly compensatory angular vestibulo-ocular reflex in multiple planes. Minimizing misalignment between the axis of eye and head rotation, apparently caused by current spread beyond each electrode’s targeted nerve branch, emerged as a key challenge. Increasing stimulation selectivity via improvements in electrode design, surgical technique and stimulus protocol will likely be required to restore AVOR function over the full range of normal behavior. PMID:17554821

Vestibulo-Ocular Reflex Responses to a Multichannel Vestibular Prosthesis Incorporating a 3D Coordinate Transformation for Correction of Misalignment

PubMed Central

Fridman, Gene Y.; Davidovics, Natan S.; Dai, Chenkai; Migliaccio, Americo A.

2010-01-01

There is no effective treatment available for individuals unable to compensate for bilateral profound loss of vestibular sensation, which causes chronic disequilibrium and blurs vision by disrupting vestibulo-ocular reflexes that normally stabilize the eyes during head movement. Previous work suggests that a multichannel vestibular prosthesis can emulate normal semicircular canals by electrically stimulating vestibular nerve branches to encode head movements detected by mutually orthogonal gyroscopes affixed to the skull. Until now, that approach has been limited by current spread resulting in distortion of the vestibular nerve activation pattern and consequent inability to accurately encode head movements throughout the full 3-dimensional (3D) range normally transduced by the labyrinths. We report that the electrically evoked 3D angular vestibulo-ocular reflex exhibits vector superposition and linearity to a sufficient degree that a multichannel vestibular prosthesis incorporating a precompensatory 3D coordinate transformation to correct misalignment can accurately emulate semicircular canals for head rotations throughout the range of 3D axes normally transduced by a healthy labyrinth. PMID:20177732

Habilitation of auditory and vestibular dysfunction.

PubMed

Snapp, Hillary A; Schubert, Michael C

2012-04-01

Although unilateral hearing loss is often the initial sign of vestibular schwannoma (VS), the pathogenesis of the associated structures within the cerebellopontine angle can result in vestibular, facial, or vascular symptoms. Removal of a VS causes deficits in hearing, balance, and gaze stability. The resulting hearing loss eliminates the benefits of binaural listening that provide localization, loudness summation, and listening-in-noise ability. Reduced balance and gaze stability increase fall risk. This review discusses modern treatment options for auditory and vestibular rehabilitation including contralateral routing of signals (CROS), bilateral CROS, bone-anchored implants, tinnitus management, gaze and gait stability exercises. Copyright © 2012 Elsevier Inc. All rights reserved.

Effect of Bluetooth headset and mobile phone electromagnetic fields on the human auditory nerve.

PubMed

Mandalà, Marco; Colletti, Vittorio; Sacchetto, Luca; Manganotti, Paolo; Ramat, Stefano; Marcocci, Alessandro; Colletti, Liliana

2014-01-01

The possibility that long-term mobile phone use increases the incidence of astrocytoma, glioma and acoustic neuroma has been investigated in several studies. Recently, our group showed that direct exposure (in a surgical setting) to cell phone electromagnetic fields (EMFs) induces deterioration of auditory evoked cochlear nerve compound action potential (CNAP) in humans. To verify whether the use of Bluetooth devices reduces these effects, we conducted the present study with the same experimental protocol. Randomized trial. Twelve patients underwent retrosigmoid vestibular neurectomy to treat definite unilateral Ménière's disease while being monitored with acoustically evoked CNAPs to assess direct mobile phone exposure or alternatively the EMF effects of Bluetooth headsets. We found no short-term effects of Bluetooth EMFs on the auditory nervous structures, whereas direct mobile phone EMF exposure confirmed a significant decrease in CNAPs amplitude and an increase in latency in all subjects. The outcomes of the present study show that, contrary to the finding that the latency and amplitude of CNAPs are very sensitive to EMFs produced by the tested mobile phone, the EMFs produced by a common Bluetooth device do not induce any significant change in cochlear nerve activity. The conditions of exposure, therefore, differ from those of everyday life, in which various biological tissues may reduce the EMF affecting the cochlear nerve. Nevertheless, these novel findings may have important safety implications. © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

Regeneration of the eighth cranial nerve in the bullfrog, Rana catesbeiana.

PubMed

Newman, A; Honrubia, V

1992-01-01

The present study was done in order to document the ability of the eighth cranial nerve of the bullfrog (Rana catesbeiana) to regenerate, the anatomic characteristics of the regenerated fibers, and the specificity of projections from individual endorgan branches of the nerve. The eighth cranial nerve was sharply transected between the ganglion cells and the brain stem in 40 healthy bullfrogs and allowed to regenerate. Anatomic studies were performed in these animals a minimum of 3 months postoperatively. Horseradish peroxidase was used to label the whole vestibular nerve or its individual endorgan branches. Labeled regenerated fibers could be identified crossing the site of the nerve section and projecting centrally to the vestibular nuclei in a pattern similar to that of normal frogs. Labeling of individual branches showed that regenerated fibers innervated the same specific areas found in normal frogs. Unlike normal animals, both thick and thin fibers projected to the medial nucleus.

Patterning of somatosympathetic reflexes

NASA Technical Reports Server (NTRS)

Kerman, I. A.; Yates, B. J.

1999-01-01

In a previous study, we reported that vestibular nerve stimulation in the cat elicits a specific pattern of sympathetic nerve activation, such that responses are particularly large in the renal nerve. This patterning of vestibulosympathetic reflexes was the same in anesthetized and decerebrate preparations. In the present study, we report that inputs from skin and muscle also elicit a specific patterning of sympathetic outflow, which is distinct from that produced by vestibular stimulation. Renal, superior mesenteric, and lumbar colonic nerves respond most strongly to forelimb and hindlimb nerve stimulation (approximately 60% of maximal nerve activation), whereas external carotid and hypogastric nerves were least sensitive to these inputs (approximately 20% of maximal nerve activation). In contrast to vestibulosympathetic reflexes, the expression of responses to skin and muscle afferent activation differs in decerebrate and anesthetized animals. In baroreceptor-intact animals, somatosympathetic responses were strongly attenuated (to <20% of control in every nerve) by increasing blood pressure levels to >150 mmHg. These findings demonstrate that different types of somatic inputs elicit specific patterns of sympathetic nerve activation, presumably generated through distinct neural circuits.

Where is straight ahead to a patient with unilateral vestibular loss?

PubMed

Saj, Arnaud; Honoré, Jacques; Bernard-Demanze, Laurence; Devèze, Arnaud; Magnan, Jacques; Borel, Liliane

2013-05-01

The vestibular system is classically associated with postural control, oculomotor reflexes and self-motion perception. The patients with vestibular loss are primarily concerned with balance and gait problems including head and trunk tilt and walking trajectory deviation to the lesioned side. These long-lasting postural and locomotor biases are thought to originate from changes in spatial perception of self. Indeed, we show here that vestibular cues are necessary for an accurate representation of body orientation. Patients with right (RVN; n=11) or left vestibular neurotomy (LVN; 9) as a treatment for Menière's disease were compared with 10 healthy controls. The subjective straight ahead (SSA) was investigated using a method disentangling lateral shift and tilt components of error. In the horizontal plane, subjects were required to align a rod with their body midline. In the frontal plane, they were asked to align the rod with the midline of head or trunk. The analysis of SSA clearly showed distinct results according to the side of the lesion. The LVN patients had a contralesional lateral shift of SSA. In addition, they showed an ipsilesional tilt, more severe for the head than for the trunk. By contrast, in RVN patients, the representation of the body midline was fairly accurate in both the horizontal and frontal planes and did not differ from that of control subjects. The present study shows deviations in body orientation representation after unilateral vestibular loss. Deviations are observed in the horizontal as well as in the frontal planes. Interestingly, only patients with left vestibular loss were concerned with these changes in perception of self-orientation in space. These data support the hypothesis of an asymmetric vestibular function in healthy subjects and confirm the similarity of functional disorders in patients with vestibular deficits or spatial neglect. For the first time, this similarity is found at the level of body representation. Copyright © 2012 Elsevier Ltd. All rights reserved.

Morphological correlation between caloric tests and vestibular hydrops in Ménière's disease using intravenous Gd enhanced inner ear MRI.

PubMed

Choi, Ji Eun; Kim, Yi-Kyung; Cho, Young Sang; Lee, Kieun; Park, Hyun Woo; Yoon, Sung Hoon; Kim, Hyung-Jin; Chung, Won-Ho

2017-01-01

The purpose of this study was to prove the hypothesis that caloric response in Ménière's disease (MD) is reduced by hydropic expansion of the vestibular labyrinth, not by vestibular hypofunction, by evaluating the correlation morphologically using an intravenous Gadolinium (IV-Gd) inner ear MRI. In study I, the prevalence of abnormal video Head Impulse Test (vHIT) results among the patients with definite unilateral MD (n = 24) and vestibular neuritis (VN) (n = 22) were investigated. All patients showed abnormal canal paresis (CP) (> 26%) on caloric tests. The prevalence of abnormal vHIT in patients with abnormal CP was significantly lower in MD patients (12.5%) than that in VN patients (81.8%) (p < 0.001). In study II, morphological correlation between caloric tests and vestibular hydrops level was evaluated in unilateral MD patients (n = 16) who had normal vHIT results. Eleven patients (61%) had abnormal CP. After taking the images of IV-Gd inner ear MRI, the vestibular hydrops ratio (endolymph volume/total lymph volume = %VH) was measured. In addition, the relative vestibular hydrops ratio (%RVH = (%VHaffected ear-%VHunaffected ear) / (%VHaffected ear + %VHunaffected ear)) was calculated. Each ratio (%VH and %RVH) was compared with average peak slow phase velocity (PSPV) and CP, respectively. In the MD patients, %VH of the affected ear correlated significantly with mean PSPV on the same side (rs = -0.569, p = 0.024), while %RVH correlated significantly with CP (rs = 0.602, p = 0.014). In most MD patients (87.5%) compared to VN patients, vHIT results were normal even though the caloric function was reduced. In addition, the reduced caloric function with normal vHIT was related to the severity of the vestibular hydrops measured by the IV-Gd inner ear MRI. These findings concluded that the abnormal caloric tests with normal vHIT in MD indicated severe endolymphatic hydrops rather than vestibular hypofunction.

Schwannomatosis: a genetic and epidemiological study.

PubMed

Evans, D Gareth; Bowers, Naomi L; Tobi, Simon; Hartley, Claire; Wallace, Andrew J; King, Andrew T; Lloyd, Simon K W; Rutherford, Scott A; Hammerbeck-Ward, Charlotte; Pathmanaban, Omar N; Freeman, Simon R; Ealing, John; Kellett, Mark; Laitt, Roger; Thomas, Owen; Halliday, Dorothy; Ferner, Rosalie; Taylor, Amy; Duff, Chris; Harkness, Elaine F; Smith, Miriam J

2018-06-16

Schwannomatosis is a dominantly inherited condition predisposing to schwannomas of mainly spinal and peripheral nerves with some diagnostic overlap with neurofibromatosis-2 (NF2), but the underlying epidemiology is poorly understood. We present the birth incidence and prevalence allowing for overlap with NF2. Schwannomatosis and NF2 cases were ascertained from the Manchester region of England (population=4.8 million) and from across the UK. Point prevalence and birth incidence were calculated from regional birth statistics. Genetic analysis was also performed on NF2 , LZTR1 and SMARCB1 on blood and tumour DNA samples when available. Regional prevalence for schwannomatosis and NF2 were 1 in 126 315 and 50 500, respectively, with calculated birth incidences of 1 in 68 956 and 1 in 27 956. Mosaic NF2 causes a substantial overlap with schwannomatosis resulting in the misdiagnosis of at least 9% of schwannomatosis cases. LZTR1 -associated schwannomatosis also causes a small number of cases that are misdiagnosed with NF2 (1%-2%), due to the occurrence of a unilateral vestibular schwannoma. Patients with schwannomatosis had lower numbers of non-vestibular cranial schwannomas, but more peripheral and spinal nerve schwannomas with pain as a predominant presenting symptom. Life expectancy was significantly better in schwannomatosis (mean age at death 76.9) compared with NF2 (mean age at death 66.2; p=0.004). Within the highly ascertained North-West England population, schwannomatosis has less than half the birth incidence and prevalence of NF2. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Head sway response to optic flow: effect of age is more important than the presence of unilateral vestibular hypofunction

PubMed Central

Sparto, Patrick J.; Furman, Joseph M.; Redfern, Mark S.

2014-01-01

Background The purpose of this study was to examine how older adults with vestibular impairment use sensory feedback for postural control. Methods Nine older adult subjects with unilateral vestibular hypofunction (UVH, mean age 69 y) and 14 older (mean age 70 y) and 8 young adult controls (CON, mean age 28 y) viewed full-field optic flow scenes while standing on a fixed or sway-referenced support surface. The subjects with UVH had 100% caloric asymmetry. Optic flow consisted of sinusoidal anterior-posterior movement of the visual surround at three frequencies and three amplitudes of stimulation. The anterior-posterior head sway was measured. The number of head sway responses that were coupled to the optic flow and magnitude of head sway during optic flow relative to during quiet stance on fixed floor was quantified. Results The number of trials in which the head sway response was significantly coupled to the optic flow was significantly greater in the Older UVH and Older CON subjects compared with the Young CON subjects. Furthermore, the magnitude of head sway was two to three times greater in Older UVH and CON compared with Young CON subjects. There was no difference in coupling or magnitude of head sway between Older UVH and Older CON subjects. The amplitude of sway was also dependent on the amount of surface support, stimulus frequency, and stimulus amplitude. Conclusions Older adults with unilateral vestibular hypofunction who are able to effectively compensate show no difference in postural responses elicited by optic flow compared with age-matched controls. PMID:17312341

Revisiting neurofibromatosis type 2 diagnostic criteria to exclude LZTR1-related schwannomatosis.

PubMed

Smith, Miriam J; Bowers, Naomi L; Bulman, Michael; Gokhale, Carolyn; Wallace, Andrew J; King, Andrew T; Lloyd, Simon K L; Rutherford, Scott A; Hammerbeck-Ward, Charlotte L; Freeman, Simon R; Evans, D Gareth

2017-01-03

To determine the specificity of the current clinical diagnostic criteria for neurofibromatosis type 2 (NF2) relative to the requirement for unilateral vestibular schwannoma (VS) and at least 2 other NF2-related tumors. We interrogated our Manchester NF2 database, which contained 205 individuals meeting NF2 criteria who initially presented with a unilateral VS. Of these, 83 (40.7%) went on to develop a contralateral VS. We concentrated our genetic analysis on a group of 70 who initially fulfilled NF2 criteria with a unilateral vestibular schwannoma and at least 2 additional nonintradermal schwannomas. Overall, 5/70 (7%) individuals with unilateral VS and at least 2 other schwannomas had a pathogenic or likely pathogenic LZTR1 mutation. Twenty of the 70 subsequently developed bilateral disease. Of the remaining 50, 5 (10%) had a germline LZTR1 mutation, equivalent to the number (n = 5) with a germline NF2 mutation. The most common etiology for unilateral VS and 2 additional NF2-associated tumors in this cohort was mosaic NF2. Germline LZTR1 and germline NF2 mutations were equally common in our cohort. This indicates that LZTR1 must be considered when making a diagnosis of NF2 in the presence of unilateral VS in individuals without a germline NF2 mutation. © 2016 American Academy of Neurology.

Revisiting neurofibromatosis type 2 diagnostic criteria to exclude LZTR1-related schwannomatosis

PubMed Central

Smith, Miriam J.; Bowers, Naomi L.; Bulman, Michael; Gokhale, Carolyn; Wallace, Andrew J.; King, Andrew T.; Lloyd, Simon K.L.; Rutherford, Scott A.; Hammerbeck-Ward, Charlotte L.; Freeman, Simon R.

2017-01-01

Objective: To determine the specificity of the current clinical diagnostic criteria for neurofibromatosis type 2 (NF2) relative to the requirement for unilateral vestibular schwannoma (VS) and at least 2 other NF2-related tumors. Methods: We interrogated our Manchester NF2 database, which contained 205 individuals meeting NF2 criteria who initially presented with a unilateral VS. Of these, 83 (40.7%) went on to develop a contralateral VS. We concentrated our genetic analysis on a group of 70 who initially fulfilled NF2 criteria with a unilateral vestibular schwannoma and at least 2 additional nonintradermal schwannomas. Results: Overall, 5/70 (7%) individuals with unilateral VS and at least 2 other schwannomas had a pathogenic or likely pathogenic LZTR1 mutation. Twenty of the 70 subsequently developed bilateral disease. Of the remaining 50, 5 (10%) had a germline LZTR1 mutation, equivalent to the number (n = 5) with a germline NF2 mutation. Conclusions: The most common etiology for unilateral VS and 2 additional NF2-associated tumors in this cohort was mosaic NF2. Germline LZTR1 and germline NF2 mutations were equally common in our cohort. This indicates that LZTR1 must be considered when making a diagnosis of NF2 in the presence of unilateral VS in individuals without a germline NF2 mutation. PMID:27856782

Comparative analysis of pharmacological treatments with N-acetyl-DL-leucine (Tanganil) and its two isomers (N-acetyl-L-leucine and N-acetyl-D-leucine) on vestibular compensation: Behavioral investigation in the cat.

PubMed

Tighilet, Brahim; Leonard, Jacques; Bernard-Demanze, Laurence; Lacour, Michel

2015-12-15

Head roll tilt, postural imbalance and spontaneous nystagmus are the main static vestibular deficits observed after an acute unilateral vestibular loss (UVL). In the UVL cat model, these deficits are fully compensated over 6 weeks as the result of central vestibular compensation. N-Acetyl-dl-leucine is a drug prescribed in clinical practice for the symptomatic treatment of acute UVL patients. The present study investigated the effects of N-acetyl-dl-leucine on the behavioral recovery after unilateral vestibular neurectomy (UVN) in the cat, and compared the effects of each of its two isomers N-acetyl-L-leucine and N-acetyl-D-leucine. Efficacy of these three drug treatments has been evaluated with respect to a placebo group (UVN+saline water) on the global sensorimotor activity (observation grids), the posture control (support surface measurement), the locomotor balance (maximum performance at the rotating beam test), and the spontaneous vestibular nystagmus (recorded in the light). Whatever the parameters tested, the behavioral recovery was strongly and significantly accelerated under pharmacological treatments with N-acetyl-dl-leucine and N-acetyl-L-leucine. In contrast, the N-acetyl-D-leucine isomer had no effect at all on the behavioral recovery, and animals of this group showed the same recovery profile as those receiving a placebo. It is concluded that the N-acetyl-L-leucine isomer is the active part of the racemate component since it induces a significant acceleration of the vestibular compensation process similar (and even better) to that observed under treatment with the racemate component only. Copyright © 2015 Elsevier B.V. All rights reserved.

Vestibular evoked myogenic potential (Vemp): evaluation of responses in normal subjects.

PubMed

Felipe, Lilian; Santos, Marco Aurélio Rocha; Gonçalves, Denise Utsch

2008-01-01

the Vestibular Evoked Myogenic Potential (Vemp) is formed by myogenic neurophysiologic responses activated by high-intensity sound stimulation. The response is registered through surface electromyography of the cervical muscles during muscle contraction. The acoustic stimuli activate the saccular macula, the vestibular inferior nerve and the pathways related to the vestibule-spinal descendant nerves. to describe Vemp parameters in a normal population. thirty adults, 13 men and 17 women with no otoneurological complaints were selected. The stimuli were 200 tone burst, with a frequency of 1Hz and intensity of 118 dB Na, band-pass filter ranging from 10Hz to 1500Hz. The first potential biphasic P13-N23 wave was analyzed. no significant difference was observed between the sides of stimulation in terms of latency and amplitude. However, a statistically significant difference was found for amplitude between genders. Vemp demonstrated to be a reliable instrument in the clinical assessment of the vestibular function.

Secondary rhinoplasty using flying-bird and vestibular tornado incisions for unilateral cleft lip patients.

PubMed

Matsuya, Tokuzo; Iida, Seiji; Kogo, Mikihiko

2003-08-01

To correct the nasal deformity in cleft lip patients, a new procedure of open rhinoplasty using a "flying-bird" incision in the nostril tip with a vestibule "tornado"-shaped incision in the cleft side is presented. The newly designed vestibular incision produces effective vestibular advancement with the freed lower lateral cartilage. The flying-bird incision makes it possible to produce a suitable nostril tip appearance with symmetrical external nostril vestibules. If the vestibular defect after flap advancement is wide, a full-thickness skin graft is used to give priority for making a good external nostril shape. This procedure is useful for most cleft lip noses, particularly in cases of moderate to severe deformity.

Preoperative Identification of Facial Nerve in Vestibular Schwannomas Surgery Using Diffusion Tensor Tractography

PubMed Central

Choi, Kyung-Sik; Kim, Min-Su; Kwon, Hyeok-Gyu; Jang, Sung-Ho

2014-01-01

Objective Facial nerve palsy is a common complication of treatment for vestibular schwannoma (VS), so preserving facial nerve function is important. The preoperative visualization of the course of facial nerve in relation to VS could help prevent injury to the nerve during the surgery. In this study, we evaluate the accuracy of diffusion tensor tractography (DTT) for preoperative identification of facial nerve. Methods We prospectively collected data from 11 patients with VS, who underwent preoperative DTT for facial nerve. Imaging results were correlated with intraoperative findings. Postoperative DTT was performed at postoperative 3 month. Facial nerve function was clinically evaluated according to the House-Brackmann (HB) facial nerve grading system. Results Facial nerve courses on preoperative tractography were entirely correlated with intraoperative findings in all patients. Facial nerve was located on the anterior of the tumor surface in 5 cases, on anteroinferior in 3 cases, on anterosuperior in 2 cases, and on posteroinferior in 1 case. In postoperative facial nerve tractography, preservation of facial nerve was confirmed in all patients. No patient had severe facial paralysis at postoperative one year. Conclusion This study shows that DTT for preoperative identification of facial nerve in VS surgery could be a very accurate and useful radiological method and could help to improve facial nerve preservation. PMID:25289119

Postural Compensation for Unilateral Vestibular Loss

PubMed Central

Peterka, Robert J.; Statler, Kennyn D.; Wrisley, Diane M.; Horak, Fay B.

2011-01-01

Postural control of upright stance was investigated in well-compensated, unilateral vestibular loss (UVL) subjects compared to age-matched control subjects. The goal was to determine how sensory weighting for postural control in UVL subjects differed from control subjects, and how sensory weighting related to UVL subjects’ functional compensation, as assessed by standardized balance and dizziness questionnaires. Postural control mechanisms were identified using a model-based interpretation of medial–lateral center-of-mass body-sway evoked by support-surface rotational stimuli during eyes-closed stance. The surface-tilt stimuli consisted of continuous pseudorandom rotations presented at four different amplitudes. Parameters of a feedback control model were obtained that accounted for each subject’s sway response to the surface-tilt stimuli. Sensory weighting factors quantified the relative contributions to stance control of vestibular sensory information, signaling body-sway relative to earth-vertical, and proprioceptive information, signaling body-sway relative to the surface. Results showed that UVL subjects made significantly greater use of proprioceptive, and therefore less use of vestibular, orientation information on all tests. There was relatively little overlap in the distributions of sensory weights measured in UVL and control subjects, although UVL subjects varied widely in the amount they could use their remaining vestibular function. Increased reliance on proprioceptive information by UVL subjects was associated with their balance being more disturbed by the surface-tilt perturbations than control subjects, thus indicating a deficiency of balance control even in well-compensated UVL subjects. Furthermore, there was some tendency for UVL subjects who were less able to utilize remaining vestibular information to also indicate worse functional compensation on questionnaires. PMID:21922014

Generalized mechanical pain sensitivity over nerve tissues in patients with strictly unilateral migraine.

PubMed

Fernández-de-las-Peñas, César; Arendt-Nielsen, Lars; Cuadrado, María Luz; Pareja, Juan A

2009-06-01

No study has previously analyzed pressure pain sensitivity of nerve trunks in migraine. This study aimed to examine the differences in mechanical pain sensitivity over specific nerves between patients with unilateral migraine and healthy controls. Blinded investigators assessed pressure pain thresholds (PPT) over the supra-orbital nerves (V1) and peripheral nerve trunks of both upper extremities (median, radial, and ulnar nerves) in 20 patients with strictly unilateral migraine and 20 healthy matched controls. Pain intensity after palpation over both supra-orbital nerves was also assessed. A pressure algometer was used to quantify PPT, whereas a 10-point numerical pain rate scale was used to evaluate pain to palpation over the supra-orbital nerve. The analysis of covariance revealed that pain to palpation over the supra-orbital nerve was significantly higher (P<0.001) on the symptomatic side (mean: 3.4, SD: 1.5) as compared with the nonsymptomatic side (mean: 0.5, SD: 1.2) in patients with migraine and both the dominant (mean: 0.2, SD: 0.4) and nondominant (mean: 0.3, SD: 0.5) sides in healthy controls. PPT assessed over the supra-orbital nerve on the symptomatic side (mean: 1.05, SD: 0.2 kg/cm) was significantly lower (P<0.05) than PPT measurements on the nonsymptomatic side (mean: 1.35, SD: 0.3 kg/cm) and either the dominant (mean: 1.9, SD: 0.2 kg/cm) or nondominant (mean: 1.9, SD: 0.3 kg/cm) sides in controls (P<0.001). Finally, PPT assessed over the median, ulnar, and radial nerves were significantly lower in patients with migraine as compared with controls (P<0.001), without side-to-side differences (P>0.6). In patients with unilateral migraine, we found increased mechano-sensitivity of the supra-orbital nerve on the symptomatic side of the head. Outside the head, the same patients showed increased mechano-sensitivity of the main peripheral nerves of both upper limbs, without asymmetries. Such diffuse hypersensitivity of the peripheral nerves lends further evidence to the presence of a state of hyperexcitability of the central nervous system in patients with unilateral migraine.

Multimodal Integration After Unilateral Labyrinthine Lesion: Single Vestibular Nuclei Neuron Responses and Implications for Postural Compensation

PubMed Central

Sadeghi, Soroush G.; Minor, Lloyd B.

2011-01-01

Plasticity in neuronal responses is necessary for compensation following brain lesions and adaptation to new conditions and motor learning. In a previous study, we showed that compensatory changes in the vestibuloocular reflex (VOR) following unilateral vestibular loss were characterized by dynamic reweighting of inputs from vestibular and extravestibular modalities at the level of single neurons that constitute the first central stage of VOR signal processing. Here, we studied another class of neurons, i.e., the vestibular-only neurons, in the vestibular nuclei that mediate vestibulospinal reflexes and provide information for higher brain areas. We investigated changes in the relative contribution of vestibular, neck proprioceptive, and efference copy signals in the response of these neurons during compensation after contralateral vestibular loss in Macaca mulata monkeys. We show that the time course of recovery of vestibular sensitivity of neurons corresponds with that of lower extremity muscle and tendon reflexes reported in previous studies. More important, we found that information from neck proprioceptors, which did not influence neuronal responses before the lesion, were unmasked after lesion. Such inputs influenced the early stages of the compensation process evidenced by faster and more substantial recovery of the resting discharge in proprioceptive-sensitive neurons. Interestingly, unlike our previous study of VOR interneurons, the improvement in the sensitivity of the two groups of neurons did not show any difference in the early or late stages after lesion. Finally, neuronal responses during active head movements were not different before and after lesion and were attenuated relative to passive movements over the course of recovery, similar to that observed in control conditions. Comparison of compensatory changes observed in the vestibuloocular and vestibulospinal pathways provides evidence for similarities and differences between the two classes of neurons that mediate these pathways at the functional and cellular levels. PMID:21148096

Multimodal integration after unilateral labyrinthine lesion: single vestibular nuclei neuron responses and implications for postural compensation.

PubMed

Sadeghi, Soroush G; Minor, Lloyd B; Cullen, Kathleen E

2011-02-01

Plasticity in neuronal responses is necessary for compensation following brain lesions and adaptation to new conditions and motor learning. In a previous study, we showed that compensatory changes in the vestibuloocular reflex (VOR) following unilateral vestibular loss were characterized by dynamic reweighting of inputs from vestibular and extravestibular modalities at the level of single neurons that constitute the first central stage of VOR signal processing. Here, we studied another class of neurons, i.e., the vestibular-only neurons, in the vestibular nuclei that mediate vestibulospinal reflexes and provide information for higher brain areas. We investigated changes in the relative contribution of vestibular, neck proprioceptive, and efference copy signals in the response of these neurons during compensation after contralateral vestibular loss in Macaca mulata monkeys. We show that the time course of recovery of vestibular sensitivity of neurons corresponds with that of lower extremity muscle and tendon reflexes reported in previous studies. More important, we found that information from neck proprioceptors, which did not influence neuronal responses before the lesion, were unmasked after lesion. Such inputs influenced the early stages of the compensation process evidenced by faster and more substantial recovery of the resting discharge in proprioceptive-sensitive neurons. Interestingly, unlike our previous study of VOR interneurons, the improvement in the sensitivity of the two groups of neurons did not show any difference in the early or late stages after lesion. Finally, neuronal responses during active head movements were not different before and after lesion and were attenuated relative to passive movements over the course of recovery, similar to that observed in control conditions. Comparison of compensatory changes observed in the vestibuloocular and vestibulospinal pathways provides evidence for similarities and differences between the two classes of neurons that mediate these pathways at the functional and cellular levels.

Hyperventilation-induced nystagmus in patients with vestibular schwannoma.

PubMed

Califano, Luigi; Iorio, Giuseppina; Salafia, Francesca; Mazzone, Salvatore; Califano, Maria

2015-02-01

To determine the utility of the hyperventilation test (HVT) in the diagnosis of vestibular schwannoma (VS). A retrospective analysis of hyperventilation-induced nystagmus (HVIN) in 45 patients with unilateral VS. A tertiary referral center. Forty-five patients with VS; 30 patients with chronic vestibular neuritis; 20 healthy subjects with normal hearing and without symptoms or a history of vertigo, migraine, or neurological diseases (control group). Audiological and vestibular examination; "side-stream" measurement of end-tidal CO2 pressure (P(EtCO2)) to standardize the procedure; magnetic resonance imaging (MRI) centered on the cerebellopontine angle. An analysis of HVIN, its patterns, and its appearance threshold via the measurement of P(EtCO2) correlations with the tumor size. HVIN was observed in 40 of 45 cases (88.9%) in the schwannoma group and in 12 of 30 cases (40%) in the chronic vestibular neuritis group; HVIN was not observed in the control group (0/20 cases) (p < 0.001). In the schwannoma group, HVIN was evoked at a mean P(EtCO2) value of 16.5 ± 1.15 mm Hg. The hypofunctional labyrinth was identified with high sensibility and specificity through caloric test, head shaking test, and head thrust test. The excitatory pattern, which included HVIN with slow phases that beat toward the hypofunctional side, and the paretic pattern, which included HVIN with slow phases that beat toward the hypofunctional side, were not significantly associated with VS size (19.04 ± 10.56 mm for the excitatory pattern and 19.06 ± 11.01 mm for the paretic pattern). The difference in the VS size in HVIN+ (19.05 ± 10.60 mm) and HVIN- (8.40 ± 2.19 mm) cases was significant (p = 0.009). A 60-second hyperventilation event causes metabolic changes in the vestibular system and reveals a latent vestibular asymmetry. The presence of an excitatory pattern is the major criterion that suggests VS in patients with signs of unilateral vestibular deficit.

Superficial neurofibromas in the setting of schwannomatosis: nosologic implications.

PubMed

Rodriguez, Fausto J; Scheithauer, Bernd W; George, David; Midha, Rajiv; MacCollin, Mia; Stemmer-Rachamimov, Anat O

2011-05-01

First described in the past decade, schwannomatosis is a syndrome distinct from neurofibromatosis 2 (NF2). It is characterized by the development of multiple schwannomas, sparing the vestibular division of cranial nerve VIII, and may also predispose to develop meningiomas. We report two female patients, a 27 and a 44 years old who developed multiple peripheral schwannomas, but without involvement of the vestibular nerves, satisfying clinical criteria for schwannomatosis. Lack of vestibular nerve involvement was confirmed with MRI using an internal auditory canal protocol with 3 mm thick slices in both patients after age 30. Both patients developed a small neurofibroma in axillary subcutaneous tissues and a diffuse cutaneous neurofibroma of the left buttock, respectively. This report highlights that superficial neurofibromas may arise in the setting of schwannomatosis, which may have implications for the diagnostic criteria of this unique syndrome. In particular, the presence of a cutaneous neurofibroma in a patient with multiple schwannomas should not lead to a diagnosis of NF2.

Superficial neurofibromas in the setting of schwannomatosis: nosologic implications

PubMed Central

Scheithauer, Bernd W.; George, David; Midha, Rajiv; MacCollin, Mia; Stemmer-Rachamimov, Anat O.

2015-01-01

First described in the past decade, schwannomatosis is a syndrome distinct from neurofibromatosis 2 (NF2). It is characterized by the development of multiple schwannomas, sparing the vestibular division of cranial nerve VIII, and may also predispose to develop meningiomas. We report two female patients, a 27 and a 44 years old who developed multiple peripheral schwannomas, but without involvement of the vestibular nerves, satisfying clinical criteria for schwannomatosis. Lack of vestibular nerve involvement was confirmed with MRI using an internal auditory canal protocol with 3 mm thick slices in both patients after age 30. Both patients developed a small neurofibroma in axillary subcutaneous tissues and a diffuse cutaneous neurofibroma of the left buttock, respectively. This report highlights that superficial neurofibromas may arise in the setting of schwannomatosis, which may have implications for the diagnostic criteria of this unique syndrome. In particular, the presence of a cutaneous neurofibroma in a patient with multiple schwannomas should not lead to a diagnosis of NF2. PMID:21191601

Changes in the Vestibular System with Age: An Abstracted Bibliography,

DTIC Science & Technology

1981-04-30

group." COMMENT: Similar to other articles in this series, showing significant loss of afferents (and possibly efferents) in the vestibular nerve. k...marked dependence of postural stability on vision . In them, the disturbing optokinetic stimulus leads to a marked ipsilateral postural deviation or...SUBJECTS (Number-age): N/A EXPERIMENTAL PROCEDURES: Review FINDINGS: 1. No mention of vestibular functioning. 2. Review sections on vision , audition

The induction and compensation of asymmetric eye movements following unilateral blockage of a horizontal semicircular canal in the rabbit.

PubMed

Barmack, N H; Pettorossi, V E

1988-08-01

The influence of unilateral plugs of the left horizontal semicircular canal (LHC plugs) of rabbits on the development and compensation of asymmetric eye movements evoked by horizontal vestibular stimulation was studied. LHC plugs caused an immediate reduction of 50-65% in the gain of the horizontal vestibuloocular reflex (HVOR). This reduction in gain was achieved without altering the symmetry of the HVOR, and was accompanied by a change in the axial alignment of eye movements evoked by vestibular stimulation about the vertical (HVOR) and longitudinal (VVOR) axes. Postoperative asymmetry of eye movements developed 12-48 hr after the plugging operation. The development of asymmetry was reduced if the rabbit was restrained for 24 hr, thereby minimizing vestibular stimulation following the plugging operation. Over a 3-4 week period, the normal symmetry of eye movements was restored and the axial alignments of the HVOR and VVOR returned to the preoperative values. The gain of the HVOR did not recover. The horizontal cervicoocular reflex (HCOR) was examined before the plugging operation and after compensation of asymmetry was complete. The gain and phase of the HCOR were not altered. A relatively simple set of explanations at a cellular level is proposed to account for the induction and compensation of asymmetric eye movements following a unilateral plug of the horizontal semicircular canal.

Consequences and assessment of human vestibular failure: implications for postural control.

PubMed

Colebatch, James G

2002-01-01

Labyrinthine afferents respond to both angular velocity (semicircular canals) and linear acceleration (otoliths), including gravity. Given their response to gravity, the otoliths are likely to have an important role in the postural functions of the vestibular apparatus. Unilateral vestibular ablation has dramatic effects on posture in many animals, but less so in primates. Nevertheless, bilateral vestibular lesions lead to disabling symptoms in man related to disturbed ocular and postural control and impaired perception of slopes and accelerations. While seimicircular canal function can be assessed through its effects on vestibular ocular reflexes, assessment of otolith function in man has traditionally been much more difficult. Recent definition of a short latency vestibulocollic reflex, activated by sound and appearing to arise from the saccule, shows promise as a new method of non-invasive assessment of otolith function.

Outcomes after vestibular rehabilitation and Wii® therapy in patients with chronic unilateral vestibular hypofunction.

PubMed

Verdecchia, Daniel H; Mendoza, Marcela; Sanguineti, Florencia; Binetti, Ana C

2014-01-01

Vestibular rehabilitation therapy is an exercise-based programme designed to promote central nervous system compensation for inner ear deficit. The objective of the present study was to analyse the differences in the perception of handicap, the risk of falls, and gaze stability in patients diagnosed with chronic unilateral vestibular hypofunction before and after vestibular rehabilitation treatment with complementary Wii® therapy. A review was performed on the clinical histories of patients in the vestibular rehabilitation area of a university hospital between April 2009 and May 2011. The variables studied were the Dizziness Handicap Inventory, the Dynamic Gait Index and dynamic visual acuity. All subjects received complementary Wii® therapy. There were 69 cases (41 woman and 28 men), with a median age of 64 years. The initial median Dizziness Handicap Inventory score was 40 points (range 0-84, percentile 25-75=20-59) and the final, 24 points (range 0-76, percentile 25-75=10.40), P<.0001. The initial median for the Dynamic Gait Index score was 21 points (range 8-24, percentile 25-75=17.5-2.3) and the final, 23 (range 12-24, percentile 25-75=21-23), P<.0001. The initial median for dynamic visual acuity was 2 (range 0-6, percentile 25-75=1-4) and the final, 1 (range 0-3, percentile 25-75=0-2), P<.0001. A reduction was observed in the Dizziness Handicap Inventory Values. Values for the Dynamic Gait Index increased and dynamic visual acuity improved. All these variations were statistically significant. Copyright © 2013 Elsevier España, S.L.U. y Sociedad Española de Otorrinolaringología y Patología Cérvico-Facial. All rights reserved.

Climbing fibers mediate vestibular modulation of both "complex" and "simple spikes" in Purkinje cells.

PubMed

Barmack, N H; Yakhnitsa, V

2015-10-01

Climbing and mossy fibers comprise two distinct afferent paths to the cerebellum. Climbing fibers directly evoke a large multispiked action potential in Purkinje cells termed a "complex spike" (CS). By logical exclusion, the other class of Purkinje cell action potential, termed "simple spike" (SS), has often been attributed to activity conveyed by mossy fibers and relayed to Purkinje cells through granule cells. Here, we investigate the relative importance of climbing and mossy fiber pathways in modulating neuronal activity by recording extracellularly from Purkinje cells, as well as from mossy fiber terminals and interneurons in folia 8-10. Sinusoidal roll-tilt vestibular stimulation vigorously modulates the discharge of climbing and mossy fiber afferents, Purkinje cells, and interneurons in folia 9-10 in anesthetized mice. Roll-tilt onto the side ipsilateral to the recording site increases the discharge of both climbing fibers (CSs) and mossy fibers. However, the discharges of SSs decrease during ipsilateral roll-tilt. Unilateral microlesions of the beta nucleus (β-nucleus) of the inferior olive blocks vestibular modulation of both CSs and SSs in contralateral Purkinje cells. The blockage of SSs occurs even though primary and secondary vestibular mossy fibers remain intact. When mossy fiber afferents are damaged by a unilateral labyrinthectomy (UL), vestibular modulation of SSs in Purkinje cells ipsilateral to the UL remains intact. Two inhibitory interneurons, Golgi and stellate cells, could potentially contribute to climbing fiber-induced modulation of SSs. However, during sinusoidal roll-tilt, only stellate cells discharge appropriately out of phase with the discharge of SSs. Golgi cells discharge in phase with SSs. When the vestibularly modulated discharge is blocked by a microlesion of the inferior olive, the modulated discharge of CSs and SSs is also blocked. When the vestibular mossy fiber pathway is destroyed, vestibular modulation of ipsilateral CSs and SSs persists. We conclude that climbing fibers are primarily responsible for the vestibularly modulated discharge of both CSs and SSs. Modulation of the discharge of SSs is likely caused by climbing fiber-evoked stellate cell inhibition.

Morphologically mixed chemical-electrical synapses formed by primary afferents in rodent vestibular nuclei as revealed by immunofluorescence detection of connexin36 and vesicular glutamate transporter-1

PubMed Central

Nagy, James I.; Bautista, Wendy; Blakley, Brian; Rash, John E.

2013-01-01

Axon terminals forming mixed chemical/electrical synapses in the lateral vestibular nucleus of rat were described over forty years ago. Because gap junctions formed by connexins are the morphological correlate of electrical synapses, and with demonstrations of widespread expression of the gap junction protein connexin36 (Cx36) in neurons, we investigated the distribution and cellular localization of electrical synapses in the adult and developing rodent vestibular nuclear complex, using immunofluorescence detection of Cx36 as a marker for these synapses. In addition, we examined Cx36 localization in relation to that of the nerve terminal marker vesicular glutamate transporter-1 (vglut-1). An abundance of immunolabelling for Cx36 in the form of Cx36-puncta was found in each of the four major vestibular nuclei of adult rat and mouse. Immunolabelling was associated with somata and initial dendrites of medium and large neurons, and was absent in vestibular nuclei of Cx36 knockout mice. Cx36-puncta were seen either dispersed or aggregated into clusters on the surface of neurons, and were never found to occur intracellularly. Nearly all Cx36-puncta were localized to large nerve terminals immunolabelled for vglut-1. These terminals and their associated Cx36-puncta were substantially depleted after labyrinthectomy. Developmentally, labelling for Cx36 was already present in the vestibular nuclei at postnatal day 5, where it was only partially co-localized with vglut-1, and did not become fully associated with vglut-1-positive terminals until postnatal day 20 to 25. The results show that vglut-1-positive primary afferent nerve terminals form mixed synapses throughout the vestibular nuclear complex, that the gap junction component of these synapses contain Cx36, that multiple Cx36-containing gap junctions are associated with individual vglut-1 terminals and that the development of these mixed synapses is protracted over several postnatal weeks. PMID:23912039

Long-term results of Gamma-knife stereotactic radiosurgery for vestibular schwannomas in patients with type 2 neurofibromatosis.

PubMed

Spatola, G; Carron, R; Delsanti, C; Thomassin, J-M; Roche, P-H; Régis, J

2016-08-12

The aim of this study was to analyze the long-term results of Gamma-knife radiosurgery treatment of vestibular schwannomas in type 2 neurofibromatosis patients. A cohort of 129 treatments for vestibular schwannomas in 103 patients was selected from a prospectively-maintained clinical database. Tumor control was assessed by volumetric analysis of the tumor at the last follow-up. Any need of a further procedure such as microsurgical removal or second treatment was regarded as a failure of tumor control. Hearing function was assessed based on Gardner-Robertson classification. Progression-free survival and functional hearing preservation rates were estimated using the Kaplan-Meier method. The median age at treatment was 34 years with no gender predominance. The median tumor volume was 1.5cm 3 . At a median clinical follow-up of 5.9 years, five patients had died, four underwent a second radiosurgical procedure and eight underwent microsurgical resection. Progression-free survival was 88 and 75% respectively at 5 and 10 years. Hearing was considered serviceable in 70 ears and remained functional in 28 ears. Kaplan-Meier estimates for 5 and 10 years functional hearing was 47 and 34%, respectively. Three patients developed new facial nerve palsy after radiosurgery at 15 days, 6 and 19 months respectively and only one partially recovered. Five patients complained of a subjective instability worsening. Four cases developed trigeminal neuropathy. No predictive factors were found to be statistically correlated with a better hearing outcome or an improved tumor growth control. Results prove less satisfying than in sporadic unilateral schwannomas. However, the lower rate of mortality and morbidity compared with microsurgical resection may support a proactive role of Gamma-knife in this pathology. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Polyamines in the lateral vestibular nuclei of the squirrel monkey and their potential role in vestibular compensation

NASA Technical Reports Server (NTRS)

Henley, C.; Igarashi, M.

1993-01-01

Polyamine synthesis increases in response to injurious stimuli including axotomy and denervation. Reduced eye nystagmus and head-deviation have been observed in unilateral labyrinthectomized (UL) guinea pigs treated with an inhibitor of polyamine synthesis, alpha-difluoromethylornithine (DFMO). We quantified polyamines in the lateral vestibular nuclei (LVN) of control and UL squirrel monkeys during the phase of vestibular compensation (VC) and performed an experiment to determine if DFMO reduces nystagmus previously observed in the guinea pig. Polyamines were detected in the LVN of control and UL squirrel monkeys. Putrescine and spermidine increased in the ipsilateral LVN 3 days after UL with no change in the contralateral LVN. No left-right differences were noted in the 5-day post-UL monkey. DFMO reduced nystagmus in a UL squirrel monkey. These findings suggest that polyamines are important in vestibular function and may contribute to nystagmus observed in VC.

Cyclin D1 expression and facial function outcome after vestibular schwannoma surgery.

PubMed

Lassaletta, Luis; Del Rio, Laura; Torres-Martin, Miguel; Rey, Juan A; Patrón, Mercedes; Madero, Rosario; Roda, Jose Maria; Gavilan, Javier

2011-01-01

The proto-oncogen cyclin D1 has been implicated in the development and behavior of vestibular schwannoma. This study evaluates the association between cyclin D1 expression and other known prognostic factors in facial function outcome 1 year after vestibular schwannoma surgery. Sixty-four patients undergoing surgery for vestibular schwannoma were studied. Immunohistochemistry analysis was performed with anticyclin D1 in all cases. Cyclin D1 expression, as well as other demographic, clinical, radiologic, and intraoperative data, was correlated with 1-year postoperative facial function. Good 1-year facial function (Grades 1-2) was achieved in 73% of cases. Cyclin D1 expression was found in 67% of the tumors. Positive cyclin D1 staining was more frequent in patients with Grades 1 to 2 (75%) than in those with Grades 3 to 6 (25%). Other significant variables were tumor volume and facial nerve stimulation after tumor resection. The area under the receiver operating characteristics curve increased when adding cyclin D1 expression to the multivariate model. Cyclin D1 expression is associated to facial outcome after vestibular schwannoma surgery. The prognostic value of cyclin D1 expression is independent of tumor size and facial nerve stimulation at the end of surgery.

Evidence for a systemic regulation of neurotrophin synthesis in response to peripheral nerve injury.

PubMed

Shakhbazau, Antos; Martinez, Jose A; Xu, Qing-Gui; Kawasoe, Jean; van Minnen, Jan; Midha, Rajiv

2012-08-01

Up-regulation of neurotrophin synthesis is an important mechanism of peripheral nerve regeneration after injury. Neurotrophin expression is regulated by a complex series of events including cell interactions and multiple molecular stimuli. We have studied neurotrophin synthesis at 2 weeks time-point in a transvertebral model of unilateral or bilateral transection of sciatic nerve in rats. We have found that unilateral sciatic nerve transection results in the elevation of nerve growth factor (NGF) and NT-3, but not glial cell-line derived neurotrophic factor or brain-derived neural factor, in the uninjured nerve on the contralateral side, commonly considered as a control. Bilateral transection further increased NGF but not other neurotrophins in the nerve segment distal to the transection site, as compared to the unilateral injury. To further investigate the distinct role of NGF in regeneration and its potential for peripheral nerve repair, we transduced isogeneic Schwann cells with NGF-encoding lentivirus and transplanted the over-expressing cells into the distal segment of a transected nerve. Axonal regeneration was studied at 2 weeks time-point using pan-neuronal marker NF-200 and found to directly correlate with NGF levels in the regenerating nerve. © 2012 The Authors. Journal of Neurochemistry © 2012 International Society for Neurochemistry.

Results of a prospective surgical audit of bilateral paediatric cochlear implantation in the UK.

PubMed

Broomfield, Stephen J; Murphy, John; Wild, Dominik C; Emmett, Stevan R; O'Donoghue, Gerard M

2014-09-01

Since being approved in 2009, bilateral simultaneous cochlear implantation (CI) has been the standard treatment for children in the UK who meet the criteria for CI. The aim was to report surgical outcomes of bilateral CI in the UK. Between January 2010 and December 2011, 14 UK CI centres collected data prospectively: demographics, aetiology, use of imaging, device type, surgery duration, use of intra-operative electrophysiology, length of stay, and post-operative complications. 1397 CI procedures in 961 CI recipients were included; 436 bilateral simultaneous, 394 bilateral sequential, and 131 unilateral. The majority (85%) were congenitally deaf. The commonest causes of acquired deafness were meningitis and cytomegalovirus infection. The median age for congenitally deaf bilateral simultaneous CI was 2.2 years, mean surgical duration 4.5 hours. 6.3% surgeries were day case procedures. Eight cases (2.0%) of planned bilateral CI had unilateral surgery. The overall major complication rate was 1.6% (0.9% excluding device failures), including explantation due to infection (0.2%), cerebrospinal fluid leak (0.2%), and meningitis (0.1%). There were no permanent facial nerve palsies and no deaths. Sixty-two (6.5%) immediate minor complications included 12 (1.3%) children with significant vestibular impairment. The complication rate was similar following bilateral CI compared to sequential and unilateral CI, and is comparable to other published series. This prospective multi-centre audit provides evidence that bilateral paediatric CI is a safe procedure in the UK, thus endorsing its role as a major therapeutic intervention in childhood deafness.

N-Acetyl-L-Leucine Accelerates Vestibular Compensation after Unilateral Labyrinthectomy by Action in the Cerebellum and Thalamus

PubMed Central

Xiong, Guoming; Potschka, Heidrun; Jahn, Klaus; Bartenstein, Peter; Brandt, Thomas; Dutia, Mayank; Dieterich, Marianne; Strupp, Michael; la Fougère, Christian; Zwergal, Andreas

2015-01-01

An acute unilateral vestibular lesion leads to a vestibular tone imbalance with nystagmus, head roll tilt and postural imbalance. These deficits gradually decrease over days to weeks due to central vestibular compensation (VC). This study investigated the effects of i.v. N-acetyl-DL-leucine, N-acetyl-L-leucine and N-acetyl-D-leucine on VC using behavioural testing and serial [18F]-Fluoro-desoxyglucose ([18F]-FDG)-μPET in a rat model of unilateral chemical labyrinthectomy (UL). Vestibular behavioural testing included measurements of nystagmus, head roll tilt and postural imbalance as well as sequential whole-brain [18F]-FDG-μPET was done before and on days 1,3,7 and 15 after UL. A significant reduction of postural imbalance scores was identified on day 7 in the N-acetyl-DL-leucine (p < 0.03) and the N-acetyl-L-leucine groups (p < 0.01), compared to the sham treatment group, but not in the N-acetyl-D-leucine group (comparison for applied dose of 24 mg i.v. per rat, equivalent to 60 mg/kg body weight, in each group). The course of postural compensation in the DL- and L-group was accelerated by about 6 days relative to controls. The effect of N-acetyl-L-leucine on postural compensation depended on the dose: in contrast to 60 mg/kg, doses of 15 mg/kg and 3.75 mg/kg had no significant effect. N-acetyl-L-leucine did not change the compensation of nystagmus or head roll tilt at any dose. Measurements of the regional cerebral glucose metabolism (rCGM) by means of μPET revealed that only N-acetyl-L-leucine but not N-acetyl-D-leucine caused a significant increase of rCGM in the vestibulocerebellum and a decrease in the posterolateral thalamus and subthalamic region on days 3 and 7. A similar pattern was found when comparing the effect of N-acetyl-L-leucine on rCGM in an UL-group and a sham UL-group without vestibular damage. In conclusion, N-acetyl-L-leucine improves compensation of postural symptoms after UL in a dose-dependent and specific manner, most likely by activating the vestibulocerebellum and deactivating the posterolateral thalamus. PMID:25803613

N-acetyl-L-leucine accelerates vestibular compensation after unilateral labyrinthectomy by action in the cerebellum and thalamus.

PubMed

Günther, Lisa; Beck, Roswitha; Xiong, Guoming; Potschka, Heidrun; Jahn, Klaus; Bartenstein, Peter; Brandt, Thomas; Dutia, Mayank; Dieterich, Marianne; Strupp, Michael; la Fougère, Christian; Zwergal, Andreas

2015-01-01

An acute unilateral vestibular lesion leads to a vestibular tone imbalance with nystagmus, head roll tilt and postural imbalance. These deficits gradually decrease over days to weeks due to central vestibular compensation (VC). This study investigated the effects of i.v. N-acetyl-DL-leucine, N-acetyl-L-leucine and N-acetyl-D-leucine on VC using behavioural testing and serial [18F]-Fluoro-desoxyglucose ([18F]-FDG)-μPET in a rat model of unilateral chemical labyrinthectomy (UL). Vestibular behavioural testing included measurements of nystagmus, head roll tilt and postural imbalance as well as sequential whole-brain [18F]-FDG-μPET was done before and on days 1,3,7 and 15 after UL. A significant reduction of postural imbalance scores was identified on day 7 in the N-acetyl-DL-leucine (p < 0.03) and the N-acetyl-L-leucine groups (p < 0.01), compared to the sham treatment group, but not in the N-acetyl-D-leucine group (comparison for applied dose of 24 mg i.v. per rat, equivalent to 60 mg/kg body weight, in each group). The course of postural compensation in the DL- and L-group was accelerated by about 6 days relative to controls. The effect of N-acetyl-L-leucine on postural compensation depended on the dose: in contrast to 60 mg/kg, doses of 15 mg/kg and 3.75 mg/kg had no significant effect. N-acetyl-L-leucine did not change the compensation of nystagmus or head roll tilt at any dose. Measurements of the regional cerebral glucose metabolism (rCGM) by means of μPET revealed that only N-acetyl-L-leucine but not N-acetyl-D-leucine caused a significant increase of rCGM in the vestibulocerebellum and a decrease in the posterolateral thalamus and subthalamic region on days 3 and 7. A similar pattern was found when comparing the effect of N-acetyl-L-leucine on rCGM in an UL-group and a sham UL-group without vestibular damage. In conclusion, N-acetyl-L-leucine improves compensation of postural symptoms after UL in a dose-dependent and specific manner, most likely by activating the vestibulocerebellum and deactivating the posterolateral thalamus.

Evidence of a gustatory-vestibular pathway for protein transport.

PubMed

Gacek, Richard; Lyon, Michael J

2010-02-01

To demonstrate anatomically a pathway for protein transport from the palate to the vestibular system. The vestibulofacial anastomosis and associated ganglion cells were identified in a collection of 160 horizontally sectioned human temporal bones that had been stained with hematoxylin and eosin. Wheat germ agglutinin-horseradish peroxidase (HRP) was applied to the greater superficial petrosal nerve in 4 Sprague-Dawley rats. After 30 hours, the rats were killed by intracardiac perfusion, and the seventh and eighth nerves with adjacent brainstem removed. Frozen sections cut at 30 mum through this block were then reacted for HRP, counterstained with neutral red, and mounted on slides for examination in the light microscope. Thirty-two of the 160 human temporal bones contained sections through the vestibulofacial anastomosis and its ganglion. In all cases, the ganglion was incorporated into the vestibular ganglion (VG) adjacent to the nervus intermedius. In all 4 experimental rats, HRP reaction product labeled a small number of ganglion cells in the VG adjacent to the nervus intermedius and facial nerve. These observations support the presence of a pathway from receptors in the palate to the VG.

Therapeutic profile of single-fraction radiosurgery of vestibular schwannoma: unrelated malignancy predicts tumor control

PubMed Central

Wowra, Berndt; Muacevic, Alexander; Fürweger, Christoph; Schichor, Christian; Tonn, Jörg-Christian

2012-01-01

Radiosurgery has become an accepted treatment option for vestibular schwannomas. Nevertheless, predictors of tumor control and treatment toxicity in current radiosurgery of vestibular schwannomas are not well understood. To generate new information on predictors of tumor control and cranial nerve toxicity of single-fraction radiosurgery of vestibular schwannomas, we conducted a single-institution long-term observational study of radiosurgery for sporadic vestibular schwannomas. Minimum follow-up was 3 years. Investigated as potential predictors of tumor control and cranial nerve toxicity were treatment technology; tumor resection preceding radiosurgery; tumor size; gender; patient age; history of cancer, vascular disease, or metabolic disease; tumor volume; radiosurgical prescription dose; and isodose line. Three hundred eighty-six patients met inclusion criteria. Treatment failure was observed in 27 patients. History of unrelated cancer (strongest predictor) and prescription dose significantly predicted tumor control. The cumulative incidence of treatment failure was 30% after 6.5 years in patients with unrelated malignancy and 10% after ≥15 years in patients without such cancer (P < .02). Tumor volume was the only predictor of trigeminal neuropathy (observed in 6 patients). No predictor of facial nerve toxicity was found. On the House and Brackmann scale, 1 patient had a permanent one-level drop and 7 a transient drop of 1 to 3 levels. Serviceable hearing was preserved in 75.1%. Tumor hearing before radiosurgery, recurrence, and prescription isodose predicted ototoxicity. Unrelated malignancy is a strong predictor of tumor control. Tumor recurrence predominantly predicts ototoxicity. These findings potentially will aid future clinical decision making in ambiguous cases. PMID:22561798

Unilateral abducens and bilateral facial nerve palsies associated with posterior fossa exploration surgery

PubMed Central

Khalil, Ayman; Clerkin, James; Mandiwanza, Tafadzwa; Green, Sandra; Javadpour, Mohsen

2016-01-01

Multiple cranial nerves palsies following a posterior fossa exploration confined to an extradural compartment is a rare clinical presentation. This case report describes a young man who developed a unilateral abducens and bilateral facial nerve palsies following a posterior fossa exploration confined to an extradural compartment. There are different theories to explain this presentation, but the exact mechanism remains unclear. We propose that this patient cranial nerve palsies developed following cerebrospinal fluid (CSF) leak, potentially as a consequence of rapid change in CSF dynamics. PMID:26951144

Changes in resting-state fMRI in vestibular neuritis.

PubMed

Helmchen, Christoph; Ye, Zheng; Sprenger, Andreas; Münte, Thomas F

2014-11-01

Vestibular neuritis (VN) is a sudden peripheral unilateral vestibular failure with often persistent head movement-related dizziness and unsteadiness. Compensation of asymmetrical activity in the primary peripheral vestibular afferents is accomplished by restoration of impaired brainstem vestibulo-ocular and vestibulo-spinal reflexes, but presumably also by changing cortical vestibular tone imbalance subserving, e.g., spatial perception and orientation. The aim of this study was to elucidate (i) whether there are changes of cerebral resting-state networks with respect to functional interregional connectivity (resting-state activity) in VN patients and (ii) whether these are related to neurophysiological, perceptual and functional parameters of vestibular-induced disability. Using independent component analysis (ICA), we compared resting-state networks between 20 patients with unilateral VN and 20 age- and gender-matched healthy control subjects. Patients were examined in the acute VN stage and after 3 months. A neural network (component 50) comprising the parietal lobe, medial aspect of the superior parietal lobule, posterior cingulate cortex, middle frontal gyrus, middle temporal gyrus, parahippocampal gyrus, anterior cingulate cortex, insular cortex, caudate nucleus, thalamus and midbrain was modulated between acute VN patients and healthy controls and in patients over time. Within this network, acute VN patients showed decreased resting-state activity (ICA) in the contralateral intraparietal sulcus (IPS), in close vicinity to the supramarginal gyrus (SMG), which increased after 3 months. Resting-state activity in IPS tended to increase over 3 months in VN patients who improved with respect to functional parameters of vestibular-induced disability (VADL). Resting-state activity in the IPS was not related to perceptual (subjective visual vertical) or neurophysiological parameters of vestibular-induced disability (e.g., gain of vestibulo-ocular reflex, caloric responsiveness, postural sway). VN leads to a change in resting-state activity of the contralateral IPS adjacent to the SMG, which reverses during vestibular compensation over 3 months. The ventral intraparietal area in the IPS contains multimodal regions with directionally selective responses to vestibular stimuli making them suitable for participating in spatial orientation and multisensory integration. The clinical importance is indicated by the fact that the increase in resting-state activity tended to be larger in those patients with only little disability at the follow-up examination. This may indicate powerful restitution-related or compensatory cortical changes in resting-state activity.

[The vestibular apparatus of quail embryos in an experiment on the Kosmos-1129 biosatellite].

PubMed

Lychakov, D V; Il'inskaia, E V; Dadasheva, O A; Gur'eva, T S

1993-01-01

The light microscope was used to study serial sections of labyrinths of quail embryos incubated and reared during 12 d orbiting of Cosmos 1129. On recovery the embryos were aged 9, 11.5 and 12 days. No significant deviations in the development of the vestibular apparatus in flight species were noted as compared to the controls. Given this and our experimental data about in-space development of fish and amphibians we may deduce that hypo-g does not exert a noticeable altering effect on the vestibular embryogenesis. Nevertheless, it should be pointed out that in all otolith organs and semicircular channel ampules of the flight embryos cup-form neural endings innervating type I sensory cells were markedly swollen in contrast to the control. Earlier swollen cup-form nerve endings have been found in one adult rat after 7 days of space flight aboard Cosmos 1667. However, exposure in space does not bring about a substantial swelling of bud-like nerve endings which contact type II sensory cells. Thus, a conclusion may be drawn that spaceflight factors are liable to produce shifts in the type I sensory cell--cup-form nerve ending unit but they do not affect type II sensory cell--bud-like nerve ending unit to the extent when effects can be identified by light microscopy.

Nicergoline facilitates vestibular compensation in aged male rats with unilateral labyrinthectomy.

PubMed

Rampello, L; Drago, F

1999-05-28

The ergoline derivatives, nicergoline (NIC) or dihydroergocristine (DHE) were administered at various doses (0.1, 0.5 and 1 mg/kg) to aged male rats subjected to labyrinth unilateral lesion (LBX). The nystagmus rate appeared to be lower in animals treated with DHE or NIC 1mg/kg than in saline-injected rats, when observed on day 1 and 2 after operation. The number of falls in the rotorod test of LBX animals was decreased by NIC 0.5 or 1 mg/kg at all observation times. This parameter was affected by DHE only at the higher dose. These results suggest that NIC facilitates vestibular compensation of LBX rats. DHE appeared to be less potent in this respect. Since both drugs act on central dopaminergic neurotransmission, it is possible that this neurotransmission may be involved in their mechanism of action.

Effect of Carbon Dioxide Laser on Increasing Vestibular Depth in Cleft Lip and Palate Patients.

PubMed

Yassaei, Sogra; Aghili, Hossein; Azam, Alireza Navab; Moghadam, Mahjobeh Gholdani; Safari, Isa

2017-09-01

Shallow upper buccal sulcus deformity in cleft lip and palate patients is one of the common secondary deformities after primary cleft lip and palate repair; this deformity may prevent or complicate orthodontic and prosthodontic procedures causing aesthetic and functional problems. A number of methods are described to increase the anterior maxillary sulcus in these patients. This study assessed the use of a carbon dioxide laser (CO 2 ) to increase the sulcus depth. Fifteen patients with cleft lip and palate (eight unilateral and seven bilateral) were studied. The surgical procedure was performed using CO 2 laser. The vestibular depth and lip length were measured at three time points namely before surgery (T0), 1 week following surgery (T1), and 4 months following surgery (T2). After data collection, statistical analyses were done using PASW ® version 18 SPSS. The mean values of vestibular depth were 9.46 ± 1.92, 13.83 ± 1.88, and 13.23 ± 1.76 mm for T0, T1, and T2, respectively. The vestibular depth significantly increased after 4 months of follow-up (p = 0.001). The mean amount of vestibular depth gain was not significantly different in unilateral and bilateral cleft groups (p = 0.908). The mean value of upper lip length increased by a mean of 1.23 mm and was statistically significant (p = 0.001). Upper buccal sulcus reconstruction with CO 2 laser provides successful and stable results. CO 2 laser application is suggested as an alternative to conventional vestibuloplasty.

Contribution of intracranial vertebral artery asymmetry to vestibular neuropathy.

PubMed

Chuang, Y M; Chern, C M; Liao, W H; Hsu, L C; Lien, C F; Lirng, J F; Shiao, A S; Ko, J S C

2011-07-01

To test the hypothesis that vertebral artery hypoplasia (VAH) may affect the lateralisation of vestibular neuropathy (VN), probably through haemodynamic effect on the vestibular labyrinth. 69 patients with unilateral VN were examined with a magnetic resonance angiographic (MRA) and caloric test. 50 healthy subjects served as controls. The diagnosis of intracranial VAH was based on MRA if <0.22 cm in VA diameter and a diameter asymmetry index >40%. The authors then correlated the canal paretic side with the VAH side. MRA study revealed 29 VAH (right/left: 23/6) in VN subjects and six VAH in controls (right/left: 5/1). The RR of VAH in VN subjects compared with controls was elevated (RR=2.2; 95% CI 1.8 to 2.8). There was a high accordance rate between the side of VAH and VN. Among 29 patients with unilateral VAH, 65.5% (N=19) had an ipsilateral VN, in which left VAH showed a higher accordance rate (83.3%) than the right side (60.9%). VN subjects with vascular risk factors also had a higher VAH accordance rate (81%) than those without (25%). VAH may serve as a regional haemodynamic negative contributor and impede blood supply to the ipsilateral vestibular labyrinth, contributing to the development of VN, which could be enhanced by atherosclerotic risk factors and the left-sided location.

Saccadic entropy of head impulses in acute unilateral vestibular loss.

PubMed

Hsieh, Li-Chun; Lin, Hung-Ching; Lee, Guo-She

2017-10-01

To evaluate the complexity of vestibular-ocular reflex (VOR) in patients with acute unilateral vestibular loss (AUVL) via entropy analysis of head impulses. Horizontal head impulse test (HIT) with high-velocity alternating directions was used to evaluate 12 participants with AUVL and 16 healthy volunteers. Wireless electro-oculography and electronic gyrometry were used to acquire eye positional signals and head velocity signals. The eye velocity signals were then obtained through differentiation, band-pass filtering. The approximate entropy of eye velocity to head velocity (R ApEn ) was used to evaluate chaos property. VOR gain, gain asymmetry ratio, and R ApEn asymmetry ratio were also used to compare the groups. For the lesion-side HIT of the patient group, the mean VOR gain was significantly lower and the mean R ApEn was significantly greater compared with both nonlesion-side HIT and healthy controls (p < 0.01, one-way analysis of variance). Both the R ApEn asymmetry ratio and gain asymmetry ratio of the AUVL group were significantly greater compared with those of the control group (p < 0.05, independent sample t test). Entropy and gain analysis of HIT using wireless electro-oculography system could be used to detect the VOR dysfunctions of AUVL and may become effective methods for evaluating vestibular disorders. Copyright © 2017. Published by Elsevier B.V.

Ocular vestibular evoked myogenic potentials to vertex low frequency vibration as a diagnostic test for superior canal dehiscence.

PubMed

Verrecchia, Luca; Westin, Magnus; Duan, Maoli; Brantberg, Krister

2016-04-01

To explore ocular vestibular evoked myogenic potentials (oVEMP) to low-frequency vertex vibration (125 Hz) as a diagnostic test for superior canal dehiscence (SCD) syndrome. The oVEMP using 125 Hz single cycle bone-conducted vertex vibration were tested in 15 patients with unilateral superior canal dehiscence (SCD) syndrome, 15 healthy controls and in 20 patients with unilateral vestibular loss due to vestibular neuritis. Amplitude, amplitude asymmetry ratio, latency and interaural latency difference were parameters of interest. The oVEMP amplitude was significantly larger in SCD patients when affected sides (53 μVolts) were compared to non-affected (17.2 μVolts) or compared to healthy controls (13.6 μVolts). Amplitude larger than 33.8 μVolts separates effectively the SCD ears from the healthy ones with sensitivity of 87% and specificity of 93%. The other three parameters showed an overlap between affected SCD ears and non-affected as well as between SCD ears and those in the two control groups. oVEMP amplitude distinguishes SCD ears from healthy ones using low-frequency vibration stimuli at vertex. Amplitude analysis of oVEMP evoked by low-frequency vertex bone vibration stimulation is an additional indicator of SCD syndrome and might serve for diagnosing SCD patients with coexistent conductive middle ear problems. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Postural compensation for vestibular loss and implications for rehabilitation.

PubMed

Horak, Fay B

2010-01-01

This chapter summarizes the role of the vestibular system in postural control so that specific and effective rehabilitation can be designed that facilitates compensation for loss of vestibular function. Patients with bilateral or unilateral loss of peripheral vestibular function are exposed to surface perturbations to quantify automatic postural responses. Studies also evaluated the effects of audio- and vibrotactile-biofeedback to improve stability in stance and gait. The most important role of vestibular information for postural control is to control orientation of the head and trunk in space with respect to gravitoinertial forces, particularly when balancing on unstable surfaces. Vestibular sensory references are particularly important for postural control at high frequencies and velocities of self-motion, to reduce trunk drift and variability, to provide an external reference frame for the trunk and head in space; and to uncouple coordination of the trunk from the legs and the head-in-space from the body CoM. The goal of balance rehabilitation for patients with vestibular loss is to help patients 1) use remaining vestibular function, 2) depend upon surface somatosensory information as their primary postural sensory system, 3) learn to use stable visual references, and 4) identify efficient and effective postural movement strategies.

Post-traumatic Unilateral Avulsion of the Abducens Nerve with Damage to Cranial Nerves VII and VIII: Case Report.

PubMed

Yamasaki, Fumiyuki; Akiyama, Yuji; Tsumura, Ryu; Kolakshyapati, Manish; Adhikari, Rupendra Bahadur; Takayasu, Takeshi; Nosaka, Ryo; Kurisu, Kaoru

2016-07-01

Traumatic injuries of the abducens nerve as a consequence of facial and/or head trauma occur with or without associated cervical or skull base fracture. This is the first report on unilateral avulsion of the abducens nerve in a 29-year-old man with severe right facial trauma. In addition, he exhibited mild left facial palsy, and moderate left hearing disturbance. Magnetic resonance imaging (MRI) using fast imaging employing steady-state acquisition (FIESTA) revealed avulsion of left sixth cranial nerve. We recommend thin-slice MR examination in patients with abducens palsy after severe facial and/or head trauma.

Vestibular dysfunction in the adult CBA/CaJ mouse after lead and cadmium treatment

PubMed Central

Klimpel, Katarina E. M.; Lee, Min Young; King, W. Michael; Raphael, Yehoash; Schacht, Jochen; Neitzel, Richard L.

2017-01-01

OBJECTIVES The vestibular system allows the perception of position and motion and its dysfunction presents as motion impairment, vertigo and balance abnormalities, leading to debilitating psychological discomfort and difficulty performing daily tasks. Although declines and deficits in vestibular function have been noted in rats exposed to lead (Pb) and in humans exposed to Pb and cadmium (Cd), no studies have directly examined the pathological and pathophysiological effects upon the vestibular apparatus of the inner ear. METHODS Eighteen young adult mice were exposed through their drinking water (3 mM Pb, 300 μM Cd, or a control treatment) for 10 weeks. Before and after treatment, they underwent a vestibular assessment, consisting of a rotarod performance test and a novel head stability test to measure the vestibulocolic reflex. At the conclusion of the study, the utricles were analyzed immunohistologically for condition of hair cells and nerve fibers. RESULTS Increased levels of Pb exposure correlated with decreased head stability in space; no significant decline in performance on rotarod test was found. No damage to the hair cells or the nerve fibers of the utricle was observed in histology. CONCLUSIONS The young adult CBA/CaJ mouse is able to tolerate occupationally-relevant Pb and Cd exposure well, but the correlation between Pb exposure and reduced head stability suggests that Pb exposure causes a decline in vestibular function. PMID:27257108

Effects of Weightlessness on Vestibular Development: Summary of Research on NIH.R1

NASA Technical Reports Server (NTRS)

Fritzsch, Bernd; Bruce, L. L.

1998-01-01

In our original application we proposed to investigate the effects of gravity on the formation of connections between the gravity receptors of the ear and the brain in rat pups raised in space beginning at an age before these connections are made until near the time of birth, when they are to some extent functional. We used the neuronal tracer, Dil, which could be applied to tissue obtained immediately after landing of the space shuttle, thus minimizing changes due to the earth's gravity. We hoped to determine whether the vestibular system develops in two phases, as do other sensory systems (such as the visual system). In these other systems the first phase of development is controlled genetically and the second phase is controlled by environmental stimulation. Our data collected strongly supports the idea that the vestibular system has these same two phases of development. The tissue obtained from the NIH.R1 experiment was of exceptionally high quality for our analysis. Therefore, we expanded our investigation into the ultrastructural effects of microgravity on vestibular development. For the sake of clarity we will subdivide our summary into two categories: (1) analysis of the branching pattern of axons between the vestibular nerve and the gravistatic receptors of the ear in flight and control animals, and (2) analysis of the branching pattern of axons between the vestibular nerve and the brain in flight and control animals.

Radiotherapy for Vestibular Schwannomas: A Critical Review

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

Murphy, Erin S., E-mail: murphye3@ccf.or; Suh, John H.

2011-03-15

Vestibular schwannomas are slow-growing tumors of the myelin-forming cells that cover cranial nerve VIII. The treatment options for patients with vestibular schwannoma include active observation, surgical management, and radiotherapy. However, the optimal treatment choice remains controversial. We have reviewed the available data and summarized the radiotherapeutic options, including single-session stereotactic radiosurgery, fractionated conventional radiotherapy, fractionated stereotactic radiotherapy, and proton beam therapy. The comparisons of the various radiotherapy modalities have been based on single-institution experiences, which have shown excellent tumor control rates of 91-100%. Both stereotactic radiosurgery and fractionated stereotactic radiotherapy have successfully improved cranial nerve V and VII preservation tomore » >95%. The mixed data regarding the ideal hearing preservation therapy, inherent biases in patient selection, and differences in outcome analysis have made the comparison across radiotherapeutic modalities difficult. Early experience using proton therapy for vestibular schwannoma treatment demonstrated local control rates of 84-100% but disappointing hearing preservation rates of 33-42%. Efforts to improve radiotherapy delivery will focus on refined dosimetry with the goal of reducing the dose to the critical structures. As future randomized trials are unlikely, we suggest regimented pre- and post-treatment assessments, including validated evaluations of cranial nerves V, VII, and VIII, and quality of life assessments with long-term prospective follow-up. The results from such trials will enhance the understanding of therapy outcomes and improve our ability to inform patients.« less

Vestibular evoked myogenic potentials (VEMP) can detect asymptomatic saccular hydrops.

PubMed

Lin, Ming-Yee; Timmer, Ferdinand C A; Oriel, Brad S; Zhou, Guangwei; Guinan, John J; Kujawa, Sharon G; Herrmann, Barbara S; Merchant, Saumil N; Rauch, Steven D

2006-06-01

The objective of this study was to explore the useful of vestibular evoked myogenic potential (VEMP) testing for detecting endolymphatic hydrops, especially in the second ear of patients with unilateral Ménière disease (MD). This study was performed at a tertiary care academic medical center. Part I consisted of postmortem temporal bone specimens from the temporal bone collection of the Massachusetts Eye & Ear Infirmary; part II consisted of consecutive consenting adult patients (n = 82) with unilateral MD by American Academy of Otolaryngology-Head and Neck Surgery criteria case histories. Outcome measures consisted of VEMP thresholds in patients and histologic saccular endolymphatic hydrops in postmortem temporal bones. Saccular hydrops was observed in the asymptomatic ear in six of 17 (35%) of temporal bones from donors with unilateral MD. Clinic patients with unilateral MD showed elevated mean VEMP thresholds and altered VEMP tuning in their symptomatic ears and, to a lesser degree, in their asymptomatic ears. Specific VEMP frequency and tuning criteria were used to define a "Ménière-like" response. This "Ménière-like" response was seen in 27% of asymptomatic ears of our patients with unilateral MD. Bilateral involvement is seen in approximately one third of MD cases. Saccular hydrops appears to precede symptoms in bilateral MD. Changes in VEMP threshold and tuning appear to be sensitive to these structural changes in the saccule. If so, then VEMP may be useful as a detector of asymptomatic saccular hydrops and as a predictor of evolving bilateral MD.

Shrinkage of ipsilateral taste buds and hyperplasia of contralateral taste buds following chorda tympani nerve transection.

PubMed

Li, Yi-Ke; Yang, Juan-Mei; Huang, Yi-Bo; Ren, Dong-Dong; Chi, Fang-Lu

2015-06-01

The morphological changes that occur in the taste buds after denervation are not well understood in rats, especially in the contralateral tongue epithelium. In this study, we investigated the time course of morphological changes in the taste buds following unilateral nerve transection. The role of the trigeminal component of the lingual nerve in maintaining the structural integrity of the taste buds was also examined. Twenty-four Sprague-Dawley rats were randomly divided into three groups: control, unilateral chorda tympani nerve transection and unilateral chorda tympani nerve transection + lingual nerve transection. Rats were allowed up to 42 days of recovery before being euthanized. The taste buds were visualized using a cytokeratin 8 antibody. Taste bud counts, volumes and taste receptor cell numbers were quantified and compared among groups. No significant difference was detected between the chorda tympani nerve transection and chorda tympani nerve transection + lingual nerve transection groups. Taste bud counts, volumes and taste receptor cell numbers on the ipsilateral side all decreased significantly compared with control. On the contralateral side, the number of taste buds remained unchanged over time, but they were larger, and taste receptor cells were more numerous postoperatively. There was no evidence for a role of the trigeminal branch of the lingual nerve in maintaining the structural integrity of the anterior taste buds.

Sonographic evaluation of the greater occipital nerve in unilateral occipital neuralgia.

PubMed

Cho, John Chin-Suk; Haun, Daniel W; Kettner, Norman W

2012-01-01

Occipital neuralgia is a headache that may result from greater occipital nerve entrapment. Entrapped peripheral nerves typically have an increase in cross-sectional area. The purpose of this study was to measure the cross-sectional area and circumference of symptomatic and asymptomatic greater occipital nerves in patients with unilateral occipital neuralgia and to correlate the greater occipital nerve cross-sectional area with headache severity, sex, and body mass index. Both symptomatic and contralateral asymptomatic greater occipital nerve cross-sectional areas and circumferences were measured by a single examiner using sonography in 17 patients. The Wilcoxon signed rank test and Spearman rank order correlation coefficient were used to analyze the data. Significant differences between the cross-sectional areas and circumferences of the symptomatic and asymptomatic greater occipital nerves were noted (P < .001). No difference existed in cross-sectional area (P = .40) or circumference (P = .10) measurements of the nerves between male and female patients. A significant correlation existed between the body mass index and symptomatic (r = 0.424; P = .045) and asymptomatic (r = 0.443; P = .037) cross-sectional areas. There was no correlation shown between the cross-sectional area of the symptomatic nerve and the severity of Headache Impact Test 6 scores (r = -0.342; P = .179). We report sonographic evidence showing an increased cross-sectional area and circumference of the symptomatic greater occipital nerve in patients with unilateral occipital neuralgia.

Vestibular-related neuroscience and manned space flight

NASA Technical Reports Server (NTRS)

Igarashi, Makoto

1988-01-01

The effects of weightlessness on the human vestibular system are examined, reviewing the results of recent investigations. The functional, neurophysiological, and neurochemical changes which occur during adaptation to weightlessness are discussed; theoretical models proposed to explain the underlying mechanism are outlined; and particular attention is given to the author's experiments on squirrel monkeys. There, good correlations were found between (1) the recovery of locomotor balance function in the acute compensation phase after unilateral labyrinthectomy and (2) the bilateral imbalance in the optical density of GABA-like immunoreactivity.

Recovery of vestibular function following hair cell destruction by streptomycin

NASA Technical Reports Server (NTRS)

Jones, T. A.; Nelson, R. C.

1992-01-01

Can the vestibular periphery of warm-blooded vertebrates recover functionally from severe sensory hair cell loss? Recent findings in birds suggest a mechanism for recovery but in fact no direct functional evidence has been reported. We produced vestibular hair cell lesions using the ototoxic agent streptomycin sulfate (600 mg/kg/day, 8 days, chicks, Gallus domesticus). Compound action potentials of the vestibular nerve were used as a direct measure of peripheral vestibular function. Vestibular thresholds, neural activation latencies and amplitudes were documented. Eight days of drug treatment elevated thresholds significantly (P < 0.001) and eliminated all but remnants of vestibular activity. Virtually complete physiological recovery occurred in all animals studied over a period of 70 days following treatment. Thresholds recovered within two weeks of drug treatment whereas the return of response morphologies including activation latencies and amplitudes required an additional 6-8 weeks.

Mastoid vibration affects dynamic postural control during gait in healthy older adults

NASA Astrophysics Data System (ADS)

Chien, Jung Hung; Mukherjee, Mukul; Kent, Jenny; Stergiou, Nicholas

2017-01-01

Vestibular disorders are difficult to diagnose early due to the lack of a systematic assessment. Our previous work has developed a reliable experimental design and the result shows promising results that vestibular sensory input while walking could be affected through mastoid vibration (MV) and changes are in the direction of motion. In the present paper, we wanted to extend this work to older adults and investigate how manipulating sensory input through mastoid vibration (MV) could affect dynamic postural control during walking. Three levels of MV (none, unilateral, and bilateral) applied via vibrating elements placed on the mastoid processes were combined with the Locomotor Sensory Organization Test (LSOT) paradigm to challenge the visual and somatosensory systems. We hypothesized that the MV would affect sway variability during walking in older adults. Our results revealed that MV significantly not only increased the amount of sway variability but also decreased the temporal structure of sway variability only in anterior-posterior direction. Importantly, the bilateral MV stimulation generally produced larger effects than the unilateral. This is an important finding that confirmed our experimental design and the results produced could guide a more reliable screening of vestibular system deterioration.

A Patient-Assessed Morbidity to Evaluate Outcome in Surgically Treated Vestibular Schwannomas.

PubMed

Al-Shudifat, Abdul Rahman; Kahlon, Babar; Höglund, Peter; Lindberg, Sven; Magnusson, Måns; Siesjo, Peter

2016-10-01

Outcome after treatment of vestibular schwannomas can be evaluated by health providers as mortality, recurrence, performance, and morbidity. Because mortality and recurrence are rare events, evaluation has to focus on performance and morbidity. The latter has mostly been reported by health providers. In the present study, we validate 2 new scales for patient-assessed performance and morbidity in comparison with different outcome tools, such as quality of life (QOL) (European Quality of Life-5 dimensions [EQ-5D]), facial nerve score, and work capacity. There were 167 total patients in a retrospective (n = 90) and prospective (n = 50) cohort of surgically treated vestibular schwannomas. A new patient-assessed morbidity score (paMS), a patient-assessed Karnofsky score (paKPS), the patient-assessed QOL (EQ-5D) score, work capacity, and the House-Brackmann facial nerve score were used as outcome measures. Analysis of paMS components and their relation to other outcomes was done as uni- and multivariate analysis. All outcome instruments, except EQ-5D and paKPS, showed a significant decrease postoperatively. Only the facial nerve score (House-Brackmann facial nerve score) differed significantly between the retrospective and prospective cohorts. Out of the 16 components of the paMS, hearing dysfunction, tear dysfunction, balance dysfunction, and eye irritation were most often reported. Both paMS and EQ-5D correlated significantly with work capacity. Standard QOL and performance instruments may not be sufficiently sensitive or specific to measure outcome at the cohort level after surgical treatment of vestibular schwannomas. A morbidity score may yield more detailed information on symptoms that can be relevant for rehabilitation and occupational training after surgery. Copyright © 2016 Elsevier Inc. All rights reserved.

Vestibular stimulation leads to distinct hemodynamic patterning

NASA Technical Reports Server (NTRS)

Kerman, I. A.; Emanuel, B. A.; Yates, B. J.

2000-01-01

Previous studies demonstrated that responses of a particular sympathetic nerve to vestibular stimulation depend on the type of tissue the nerve innervates as well as its anatomic location. In the present study, we sought to determine whether such precise patterning of vestibulosympathetic reflexes could lead to specific hemodynamic alterations in response to vestibular afferent activation. We simultaneously measured changes in systemic blood pressure and blood flow (with the use of Doppler flowmetry) to the hindlimb (femoral artery), forelimb (brachial artery), and kidney (renal artery) in chloralose-urethane-anesthetized, baroreceptor-denervated cats. Electrical vestibular stimulation led to depressor responses, 8 +/- 2 mmHg (mean +/- SE) in magnitude, that were accompanied by decreases in femoral vasoconstriction (23 +/- 4% decrease in vascular resistance or 36 +/- 7% increase in vascular conductance) and increases in brachial vascular tone (resistance increase of 10 +/- 6% and conductance decrease of 11 +/- 4%). Relatively small changes (<5%) in renal vascular tone were observed. In contrast, electrical stimulation of muscle and cutaneous afferents produced pressor responses (20 +/- 6 mmHg) that were accompanied by vasoconstriction in all three beds. These data suggest that vestibular inputs lead to a complex pattern of cardiovascular changes that is distinct from that which occurs in response to activation of other types of somatic afferents.

Unilateral Loss of Spontaneous Venous Pulsations in an Astronaut

NASA Technical Reports Server (NTRS)

Mader, Thomas H.; Gibson, C. Robert; Lee, Andrew G.; Patel, Nimesh; Hart, Steven; Pettit, Donald R.

2014-01-01

Spontaneous venous pulsations seen on the optic nerve head (optic disc) are presumed to be caused by fluctuations in the pressure gradient between the intraocular and retrolaminar venous systems. The disappearance of previously documented spontaneous venous pulsations is a well-recognized clinical sign usually associated with a rise in intracranial pressure and a concomitant bilateral elevation of pressure in the subarachnoid space surrounding the optic nerves. In this correspondence we report the unilateral loss of spontaneous venous pulsations in an astronaut 5 months into a long duration space flight. We documented a normal lumbar puncture opening pressure 8 days post mission. The spontaneous venous pulsations were also documented to be absent 21 months following return to Earth.. We hypothesize that these changes may have resulted from a chronic unilateral rise in optic nerve sheath pressure caused by a microgravity-induced optic nerve sheath compartment syndrome.

[Built-in emergency brake in the balance system. Animal experiment research shows that a hierarchy of mechanisms compensate after acute peripheral vestibular decline].

PubMed

Magnusson, Anna K; Tham, Richard

A sudden unilateral loss of peripheral vestibular input results in the onset of acute dizziness and imbalance associated with spontaneous nystagmus, postural instability and nausea. Fortunately, these symptoms ameliorate rapidly, even without treatment, due to central nervous plastic changes which are collectively termed "vestibular compensation". This concept has become a widely accepted research model for studying lesion-induced plasticity. Recent research has dealt in particular with the plasticity of the medial vestibular nuclei that mediate the horizontal vestibulo-ocular reflex. Studies range from a cellular level in vitro to a functional level in vivo. Taken together, results from such studies have contributed greatly to what is known of vestibular compensation today. This article summarises evidence for several plasticity mechanisms that drive the recovery of spontaneous nystagmus, one of which is dependent on an endocrine stress-response. In the long run, such knowledge might influence the management and treatment of patients with balance disorders.

Insensitivity of the "Romberg test of standing balance on firm and compliant support surfaces" to the results of caloric and VEMP tests.

PubMed

Jacobson, Gary P; McCaslin, Devin L; Piker, Erin G; Gruenwald, Jill; Grantham, Sarah; Tegel, Lauren

2011-01-01

The objective of this study was to assess the sensitivity, specificity, and positive and negative predictive value of the Romberg Test of Standing Balance on Firm and Compliant Support Surfaces (RTSBFCSS) for the identification of patients with vestibular system impairments affecting the horizontal semicircular canal, saccule, and/or inferior and superior vestibular nerves. The RTSBFCSS was developed for the National Health and Nutrition Examination Survey (NHANES) and was used recently to estimate the numbers of individuals aged 40 yr or older with vestibular system impairments among the general population of the United States. A retrospective analysis of the medical records of 103 consecutive patients aged 40 yr or older (mean age 59 ± 12 yr, 71 females) who had undergone vestibular assessment at the Balance Disorders Clinic at the Vanderbilt University School of Medicine. Patients with complete electro- or videonystagmography testing, cervical vestibular evoked myogenic potential (cVEMP) testing, and the RTSBFCSS screening test were included in the analysis. A series of 2 × 2 tables were created that represented the number of "true positives," "true negatives," "false positives," and "false negatives" of the RTSBFCSS under conditions where the caloric test was abnormal and then separately where the cVEMP test was abnormal. The data were analyzed in a manner such that sensitivity, specificity, and both positive and negative predictive value of the RTSBFCSS could be calculated. When the caloric test was used as the criterion standard and the subject selection criteria in the NHANES study were used (i.e., subjects who were able to maintain postural stability for trials 1-3 of the RTSBFCSS; N = 45), the sensitivity and specificity of the RTSBFCSS to impairment of the horizontal semicircular canal or superior vestibular nerve were 55% and 64%, respectively, yielding positive and negative predictive values of 55% and 64%, respectively. When all patients aged 40 yr or older were evaluated (N = 103), the sensitivity and specificity were 61% and 58%, respectively, yielding positive and negative predictive values of 39% and 78%, respectively. Using the cVEMP test as the criterion standard for the detection of impairment affecting the saccule and/or inferior vestibular nerve did not improve the performance criteria of the NHANES screening measure. The RTSBFCSS should not be used as a screening measure for vestibular impairment.

Anterior Inferior Cerebellar Arteries Juxtaposed with the Internal Acoustic Meatus and Their Relationship to the Cranial Nerve VII/VIII Complex

PubMed Central

Alonso, Fernando; Iwanaga, Joe; Oskouian, Rod J; Loukas, Marios; Demerdash, Amin; Tubbs, R. Shane

2017-01-01

Vascular loops in the cerebellopontine angle (CPA) and their relationship to cranial nerves have been used to explain neurological symptoms. The anterior inferior cerebellar artery (AICA) has variable branches producing vascular loops that can compress the facial cranial nerve (CN) VII and vestibulocochlear (CN VIII) nerves. AICA compression of the facial-vestibulocochlear nerve complex can lead to various clinical presentations, including hemifacial spasm (HFS), tinnitus, and hemiataxia. The formation of arterial loops inside or outside of the internal auditory meatus (IAM) can cause abutment or compression of CN VII and CN VIII. Twenty-five (50 sides) fresh adult cadavers underwent dissection of the cerebellopontine angle in the supine position. In regard to relationships between the AICA and the nerves of the facial/vestibulocochlear complex, 33 arteries (66%) traveled in a plane between the facial/nervus intermedius nerves and the cochlear and vestibular nerves. Five arteries (10%) traveled below the CN VII/VIII complex, six (12%) traveled posterior to the nerve complex, four (8%) formed a semi-circle around the upper half of the nerve complex, and two (4%) traveled between and partially separated the nervus intermedius and facial nerve proper. Our study found that the majority of AICA will travel in a plane between the facial/nervus intermedius nerves and the cochlear and vestibular nerves. Although the relationship between the AICA and porus acusticus and AICA and the nerves of the CN VII/VIII complex are variable, based on our findings, some themes exist. Surgeons should consider these with approaches to the cerebellopontine angle. PMID:29057182

Anterior Inferior Cerebellar Arteries Juxtaposed with the Internal Acoustic Meatus and Their Relationship to the Cranial Nerve VII/VIII Complex.

PubMed

Alonso, Fernando; Kassem, Mohammad W; Iwanaga, Joe; Oskouian, Rod J; Loukas, Marios; Demerdash, Amin; Tubbs, R Shane

2017-08-16

Vascular loops in the cerebellopontine angle (CPA) and their relationship to cranial nerves have been used to explain neurological symptoms. The anterior inferior cerebellar artery (AICA) has variable branches producing vascular loops that can compress the facial cranial nerve (CN) VII and vestibulocochlear (CN VIII) nerves. AICA compression of the facial-vestibulocochlear nerve complex can lead to various clinical presentations, including hemifacial spasm (HFS), tinnitus, and hemiataxia. The formation of arterial loops inside or outside of the internal auditory meatus (IAM) can cause abutment or compression of CN VII and CN VIII. Twenty-five (50 sides) fresh adult cadavers underwent dissection of the cerebellopontine angle in the supine position. In regard to relationships between the AICA and the nerves of the facial/vestibulocochlear complex, 33 arteries (66%) traveled in a plane between the facial/nervus intermedius nerves and the cochlear and vestibular nerves. Five arteries (10%) traveled below the CN VII/VIII complex, six (12%) traveled posterior to the nerve complex, four (8%) formed a semi-circle around the upper half of the nerve complex, and two (4%) traveled between and partially separated the nervus intermedius and facial nerve proper. Our study found that the majority of AICA will travel in a plane between the facial/nervus intermedius nerves and the cochlear and vestibular nerves. Although the relationship between the AICA and porus acusticus and AICA and the nerves of the CN VII/VIII complex are variable, based on our findings, some themes exist. Surgeons should consider these with approaches to the cerebellopontine angle.

Hypo-fractionated stereotactic radiotherapy of five fractions with linear accelerator for vestibular schwannomas: A systematic review and meta-analysis.

PubMed

Nguyen, Thien; Duong, Courtney; Sheppard, John P; Lee, Seung Jin; Kishan, Amar U; Lee, Percy; Tenn, Stephen; Chin, Robert; Kaprealian, Tania B; Yang, Isaac

2018-03-01

Vestibular schwannomas (VS) are benign tumors stemming from the eighth cranial nerve. Treatment options for VS include conservative management, microsurgery, stereotactic radiosurgery, and fractionated radiotherapy. Though microsurgery has been the standard of care for larger lesions, hypo-fractionated stereotactic radiotherapy (hypo-FSRT) is an emerging modality. However, its clinical efficacy and safety have yet to be established. We conducted a systematic review and meta-analysis of manuscripts indexed in PubMed, Scopus, Web of Science, Embase, and Cochrane databases reporting outcomes of VS cases treated with hypo-FSRT. Five studies representing a total of 228 patients were identified. Across studies, the pooled rates of tumor control, hearing, facial nerve, and trigeminal nerve preservation were 95%, 37%, 97%, and 98%. No instances of malignant induction were observed at median follow-up of 34.8 months. Complications included trigeminal neuropathy (n = 3), maxillary paresthesia (n = 1), neuralgia (n = 1), vestibular dysfunction (n = 1), radionecrosis (n = 1), and hydrocephalus (n = 1). Hypo-FSRT may be another useful approach to manage VS, but studies with extended follow-up times are required to establish long-term safety. Copyright © 2018. Published by Elsevier B.V.

The OTOLITH Experiment - Assessment of Otolith Function During Postflight Re-adaption

NASA Technical Reports Server (NTRS)

Clarke, A. H.; Wood, S. J.; Schoenfeld, U.

2010-01-01

The ongoing "Otolith" experiment is designed to comprehensively assess the otolith function during the re-adaptation phase after spaceflight. The novel protocol includes unilateral testing of each of the two otolith organs the utricle and the saccule. To assess utricle function, the otolith-ocular response (OOR) and the subjective visual vertical (SVV) are measured during unilateral centrifugation, which permits independent stimulation of the right and left ear. Measurement of the unilateral otolith-ocular response (uOOR) yields information on the response behaviour of the right and left peripheral utricles, whereas the SVV reflects the behaviour of the entire pathway from the peripheral otolith receptors to the vestibular cortex. Thus, by comparative evaluation of the results from the two tests, the degree of peripheral versus central adaptation during the post-flight period can be determined. To assess unilateral saccule function, vestibular evoked myogenic potentials (VEMP) are recorded. Since the saccules are predominantly aligned to gravity, and interplay with the antigravity muscles, it is hypothesised that these potentials shall be altered after spaceflight. To date the study has been conducted with 5 of a planned 8 short-flight Shuttle astronauts. Preliminary results will be discussed together with those from clinical studies of dizziness patients, where the same test protocol is employed. ACKNOWLEDGEMENT This work is supported by the German Aerospace Center (Grant DLR W130729) and is conducted under the auspices of ESA, in cooperation with NASA.

Our experience with facial nerve monitoring in vestibular schwannoma surgery under partial neuromuscular blockade.

PubMed

Vega-Céliz, Jorge; Amilibia-Cabeza, Emili; Prades-Martí, José; Miró-Castillo, Nuria; Pérez-Grau, Marta; Pintanel Rius, Teresa; Roca-Ribas Serdà, Francesc

2015-01-01

Facial nerve monitoring is fundamental in the preservation of the facial nerve in vestibular schwannoma surgery. Our objective was to analyse the usefulness of facial nerve monitoring under partial neuromuscular blockade. This was a retrospective analysis of 69 patients operated in a tertiary hospital. We monitored 100% of the cases. In 75% of the cases, we could measure an electromyographic response after tumour resection. In 17 cases, there was an absence of electromyographic response. Fifteen of them had an anatomic lesion with loss of continuity of the facial nerve and, in 2 cases, there was a lesion with preservation of the nerve. Preoperative facial palsy (29% 7%; P=.0349), large tumour size (88 vs. 38%; P=.0276), and a non-functional audition (88 vs. 51%; P=.0276) were significantly related with an absence of electromyographic response. Facial nerve monitoring under neuromuscular blockade is possible and safe in patients without previous facial palsy. If the patient had an electromyographic response after tumour excision, they developed better facial function in the postoperative period and after a year of follow up. Copyright © 2014 Elsevier España, S.L.U. and Sociedad Española de Otorrinolaringología y Patología Cérvico-Facial. All rights reserved.

Hearing preservation and facial nerve function after microsurgery for intracanalicular vestibular schwannomas: comparison of middle fossa and retrosigmoid approaches.

PubMed

Noudel, R; Gomis, P; Duntze, J; Marnet, D; Bazin, A; Roche, P H

2009-08-01

Therapeutic options for vestibular schwannomas (VS) include microsurgery, stereotactic radiosurgery and conservative management. Early treatment of intracanalicular vestibular schwannomas (IVS) may be advisable because their spontaneous course will show hearing loss in most cases. Advanced microsurgical techniques and continuous intraoperative monitoring of cranial nerves may allow hearing preservation (HP) without facial nerve damage. However, there are still controversies about the definition of hearing preservation, and the best surgical approach that should be used. In this study, we reviewed the main data from the recent literature on IVS surgery and compared hearing, facial function and complication rates after the retrosigmoid (RS) and middle fossa (MF) approaches, respectively. The results showed that the average HP rate after IVS surgery ranged from 58% (RS) to 62% (MF). HP varied widely depending on the audiometric criteria that were used for definition of serviceable hearing. There was a trend to show that the MF approach offered a better quality of postoperative hearing (not statistically significant), whereas the RS approach offered a better facial nerve preservation and fewer complications (not statistically significant). We believe that the timing of treatment in the course of the disease and selection between radiosurgical versus microsurgical procedure are key issues in the management of IVS. Preservation of hearing and good facial nerve function in surgery for VS is a reasonable goal for many patients with intracanalicular tumors and serviceable hearing. Once open surgery has been decided, selection of the approach mainly depends on individual anatomical considerations and experience of the surgeon.

Unilateral abducens and bilateral facial nerve palsies associated with posterior fossa exploration surgery.

PubMed

Khalil, Ayman; Clerkin, James; Mandiwanza, Tafadzwa; Green, Sandra; Javadpour, Mohsen

2016-03-06

Multiple cranial nerves palsies following a posterior fossa exploration confined to an extradural compartment is a rare clinical presentation. This case report describes a young man who developed a unilateral abducens and bilateral facial nerve palsies following a posterior fossa exploration confined to an extradural compartment. There are different theories to explain this presentation, but the exact mechanism remains unclear. We propose that this patient cranial nerve palsies developed following cerebrospinal fluid (CSF) leak, potentially as a consequence of rapid change in CSF dynamics. Published by Oxford University Press and JSCR Publishing Ltd. All rights reserved. © The Author 2016.

The relationship between the Activities-specific Balance Confidence Scale and the Dynamic Gait Index in peripheral vestibular dysfunction.

PubMed

Legters, Kristine; Whitney, Susan L; Porter, Rebecca; Buczek, Frank

2005-01-01

People with vestibular dysfunction experience dizziness, vertigo and postural instability. The persistence of these symptoms may result in decreased balance confidence. The purpose of the present study was to examine the relationship between decreased balance confidence and gait dysfunction in patients with unilateral peripheral vestibular dysfunction. A retrospective review of 137 charts with the Activities-specific Balance Confidence (ABC) Scale and the Dynamic Gait Index (DGI) scores was completed. Spearman rank-order correlation analysis was performed of the total sample, by age group and by degree of vestibular weakness. A moderate correlation of r = 0.58 (p < 0.001) was found between the ABC Scale score and the DGI score in the total sample. Those with mild or moderate vestibular weakness had a correlation of r = 0.72 (p < 0.001) between the ABC Scale score and the DGI score, compared with a correlation of r = 0.48 in those with severe or total vestibular weakness. Decreased balance confidence and increased fall risk are critical issues for people with vestibular dysfunction. The effects of aging did not have a significant impact on the relationship. The correlation between balance confidence and gait dysfunction was stronger in those with mild or moderate vestibular weakness, although those with severe or total weakness were more disabled by their vestibular symptoms.

Expression of vesicular glutamate transporters in peripheral vestibular structures and vestibular nuclear complex of rat.

PubMed

Zhang, F X; Pang, Y W; Zhang, M M; Zhang, T; Dong, Y L; Lai, C H; Shum, D K Y; Chan, Y S; Li, J L; Li, Y Q

2011-01-26

Glutamate transmission from vestibular end organs to central vestibular nuclear complex (VNC) plays important role in transferring sensory information about head position and movements. Three isoforms of vesicular glutamate transporters (VGLUTs) have been considered so far the most specific markers for glutamatergic neurons/cells. In this study, VGLUT1 and VGLUT2 were immunohistochemically localized to axon terminals in VNC and somata of vestibular primary afferents in association with their central and peripheral axon endings, and VGLUT1 and VGLUT3 were co-localized to hair cells of otolith maculae and cristae ampullaris. VGLUT1 and VGLUT2 defined three subsets of Scarpa's neurons (vestibular ganglionic neurons): those co-expressing VGLUT1 and VGLUT2 or expressing only VGLUT2, and those expressing neither. In addition, many neurons located in all vestibular subnuclei were observed to contain hybridized signals for VGLUT2 mRNA and a few VNC neurons, mostly scattered in medial vestibular nucleus (MVe), displayed VGLUT1 mRNA labelling. Following unilateral ganglionectomy, asymmetries of VGLUT1-immunoreactivity (ir) and VGLUT2-ir occurred between two VNCs, indicating that the VNC terminals containing VGLUT1 and/or VGLUT2 are partly of peripheral origin. The present data indicate that the constituent cells/neurons along the vestibular pathway selectively apply VGLUT isoforms to transport glutamate into synaptic vesicles for glutamate transmission. © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

The differential effects of acute right- vs. left-sided vestibular failure on brain metabolism.

PubMed

Becker-Bense, Sandra; Dieterich, Marianne; Buchholz, Hans-Georg; Bartenstein, Peter; Schreckenberger, Mathias; Brandt, Thomas

2014-07-01

The human vestibular system is represented in the brain bilaterally, but it has functional asymmetries, i.e., a dominance of ipsilateral pathways and of the right hemisphere in right-handers. To determine if acute right- or left-sided unilateral vestibular neuritis (VN) is associated with differential patterns of brain metabolism in areas representing the vestibular network and the visual-vestibular interaction, patients with acute VN (right n = 9; left n = 13) underwent resting state (18)F-FDG PET once in the acute phase and once 3 months later after central vestibular compensation. The contrast acute vs. chronic phase showed signal differences in contralateral vestibular areas and the inverse contrast in visual cortex areas, both more pronounced in VN right. In VN left additional regions were found in the cerebellar hemispheres and vermis bilaterally, accentuated in severe cases. In general, signal changes appeared more pronounced in patients with more severe vestibular deficits. Acute phase PET data of patients compared to that of age-matched healthy controls disclosed similarities to these patterns, thus permitting the interpretation that the signal changes in vestibular temporo-parietal areas reflect signal increases, and in visual areas, signal decreases. These data imply that brain activity in the acute phase of right- and left-sided VN exhibits different compensatory patterns, i.e., the dominant ascending input is shifted from the ipsilateral to the contralateral pathways, presumably due to the missing ipsilateral vestibular input. The visual-vestibular interaction patterns were preserved, but were of different prominence in each hemisphere and more pronounced in patients with right-sided failure and more severe vestibular deficits.

Vestibular Evoked Myogenic Potentials (VEMP) Can Detect Asymptomatic Saccular Hydrops

PubMed Central

Lin, Ming-Yee; Timmer, Ferdinand C. A.; Oriel, Brad S.; Zhou, Guangwei; Guinan, John J.; Kujawa, Sharon G.; Herrmann, Barbara S.; Merchant, Saumil N.; Rauch, Steven D.

2009-01-01

Objective The objective of this study was to explore the useful of vestibular evoked myogenic potential (VEMP) testing for detecting endolymphatic hydrops, especially in the second ear of patients with unilateral Ménière disease (MD). Methods This study was performed at a tertiary care academic medical center. Part I consisted of postmortem temporal bone specimens from the temporal bone collection of the Massachusetts Eye & Ear Infirmary; part II consisted of consecutive consenting adult patients (n = 82) with unilateral MD by American Academy of Otolaryngology–Head and Neck Surgery criteria case histories. Out-come measures consisted of VEMP thresholds in patients and histologic saccular endolymphatic hydrops in postmortem temporal bones. Results Saccular hydrops was observed in the asymptomatic ear in six of 17 (35%) of temporal bones from donors with unilateral MD. Clinic patients with unilateral MD showed elevated mean VEMP thresholds and altered VEMP tuning in their symptomatic ears and, to a lesser degree, in their asymptomatic ears. Specific VEMP frequency and tuning criteria were used to define a “Ménière-like” response. This “Ménière-like” response was seen in 27% of asymptomatic ears of our patients with unilateral MD. Conclusions Bilateral involvement is seen in approximately one third of MD cases. Saccular hydrops appears to precede symptoms in bilateral MD. Changes in VEMP threshold and tuning appear to be sensitive to these structural changes in the saccule. If so, then VEMP may be useful as a detector of asymptomatic saccular hydrops and as a predictor of evolving bilateral MD. PMID:16735912

Recognizing schwannomatosis and distinguishing it from neurofibromatosis type 1 or 2.

PubMed

Westhout, Franklin D; Mathews, Marlon; Paré, Laura S; Armstrong, William B; Tully, Patricia; Linskey, Mark E

2007-06-01

Schwannomatosis has become a newly recognized classification of neurofibromatosis. Although the genetic loci are on chromosome 22, it lacks the classic bilateral vestibular schwannomas as seen in NF-2. We present the surgical treatment of 4 patients with schwannomatosis, including a brother and sister. Case 1 presented with multiple progressively enlarging peripheral nerve sheath tumors. Case 4 presented with a trigeminal schwannoma and a vagal nerve schwannoma. Three of 4 patients had spinal intradural, extramedullary nerve sheath tumors. Surgery in all was multistaged and consisted of spinal laminectomies, site-specific explorations, and microsurgical tumor dissection and resection, with intraoperative neurophysiologic monitoring (including somatosensory-evoked and motor-evoked potentials, upper extremity electromyography and intraoperative nerve action potential monitoring, as appropriate). Intraoperatively the schwannomas had cystic and solid features and in all surgical cases the tumors arose from discrete fascicles of sensory nerve roots or sensory peripheral nerve branches. None of the patients experienced neurologic worsening as a result of their resections. Pathologic analysis of specimens from all cases demonstrated schwannoma. Not all patients with multiple schwannomas of cranial nerve, spinal nerve root, or peripheral nerve origin have NF-1 or NF-2. In schwannomatosis, these lesions are present in the absence of cutaneous stigmata, neurofibromas, vestibular schwannomas, or parenchymal brain tumors. Schwannomas in schwannomatosis can be large, cystic, and multiple. However, the predominant nerve involvement seems to be sensory and discrete fascicular in origin, facilitating microsurgical resection with minimal deficit.

Vestibular evoked myogenic potentials and health-related quality of life in patients with vestibular neuritis.

PubMed

Viciana, David; Lopez-Escamez, Jose A

2010-08-01

To evaluate the usefulness of vestibular evoked myogenic potentials (VEMPs) in subjects with vestibular neuritis (VN) and to determine the impact of the disease in health-related quality of life (HRQoL). Case series. Tertiary referral center. Fifty patients with VN (episode of sudden onset of prolonged vertigo [>24 h] associated with peripheral vestibular hypofunction, imbalance in absence of hearing loss, or other neurologic symptoms). VEMPs were measured in 41 patients by using an air-conducted 500 Hz tone burst. HRQoL was evaluated in all cases by the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36) and Dizziness Handicap Inventory Short Form (DHI-S) instruments, after the acute episode was resolved. Latencies P1 or N1 peaks, corrected amplitude or the absence of response, for VEMPs; scores obtained in SF-36 and DHI-S instruments. VEMPs showed abnormal results in 21 (51%) of 41 cases, with an increase in ipsilateral latencies for P1 and N1 peaks being the most common finding. Three patients (7%) had ipsilateral abnormal VEMP response with normal caloric response, indicating isolated involvement of inferior vestibular nerve. The total score obtained for the DHI-S was 14.76 +/- 11.07 (range, 0-34/40), suggesting a variable impact among patients with VN. For the SF-36, scores in men with VN were worse than their age-matched controls for all dimensions, except for mental health. However, women only showed lower scores for general health and social function. Abnormal VEMP responses demonstrate the involvement of the inferior vestibular nerve in half of the patients with VN. Moreover, VN has a moderate impact in HRQoL, and it is perceived more disabling by men than women.

Effects of Saccular Function on Recovery of Subjective Dizziness After Vestibular Rehabilitation.

PubMed

Jeong, Junhui; Jung, Jinsei; Lee, Jeon Mi; Suh, Michelle J; Kwak, Sang Hyun; Kim, Sung Huhn

2017-08-01

We attempted to investigate whether the integrity of saccular function influences the severity of subjective dizziness after vestibular rehabilitation in vestibular neuritis. Retrospective analysis. Tertiary referral center. Forty-six patients with acute unilateral vestibular neuritis were included. Diagnostic, therapeutic, and rehabilitative. All the patients completed vestibular rehabilitation therapy until their computerized dynamic posturography and rotary chair test results were significantly improved. The rehabilitation patients were classified into the normal to mild subjective dizziness and moderate to severe subjective dizziness groups according to the dizziness handicap inventory score (cutoff of 40). Differences between the two groups were analyzed. After rehabilitation, 32.6% of the patients still complained of moderate to severe dizziness. Age, sex distribution, the presence of comorbidities, caloric weakness, pre- and postrehabilitation gain values in rotary chair test, postrehabilitation composite scores in posturography, and the duration of rehabilitation were not significantly different between the two groups. However, initial dizziness handicap inventory (DHI) score and composite score in dynamic posturography were worse and the proportion of patients with absent cervical vestibular-evoked myogenic potential in the moderate to severe group was much higher (93.3% vs. 35.5%, p < 0.001). After multiple regression analysis of those factors, initial DHI score and absent cervical vestibular-evoked myogenic potential response were identified as being associated with higher postrehabilitation DHI score. Saccular dysfunction in acute vestibular neuritis can contribute to persistent subjective dizziness, even after the objective parameters of vestibular function tests have been improved by vestibular rehabilitation.

Unilateral phrenic nerve lesion in Lyme neuroborreliosis

PubMed Central

2013-01-01

Background Among a variety of more common differential diagnoses, the aetiology of acute respiratory failure includes Lyme neuroborreliosis. Case presentation We report an 87-years old huntsman with unilateral phrenic nerve palsy as a consequence of Lyme neuroborreliosis. Conclusion Although Lyme neuroborreliosis is a rare cause of diaphragmatic weakness, it should be considered in the differential workup because of its potentially treatable nature. PMID:23327473

Rare encounter of unilateral facial nerve palsy in an adolescent with Guillain-Barré syndrome

PubMed Central

Iqbal, Mehtab; Sharma, Parnika; Charadva, Creana; Prasad, Manish

2016-01-01

Unilateral facial nerve palsy is rarely encountered in Guillain-Barré syndrome (GBS). We report a case of an adolescent girl who presented with peripheral ascending weakness, preceded by Campylobacter jejuni infection. After treatment with intravenous immunoglobulin, the peripheral weakness improved. Electro-diagnostic testing confirmed axonal dysfunction and the patient was positive for antiganglioside antibodies. However, the patient developed unilateral left-sided facial weakness. She was managed with further intravenous immunoglobulin and intensive physiotherapy. The outcome for facial palsy was very good, with almost complete resolution after 2 weeks. PMID:26823357

Vibration-induced nystagmus in patients with vestibular schwannoma: Characteristics and clinical implications.

PubMed

Lee, Jeon Mi; Kim, Mi Joo; Kim, Jin Won; Shim, Dae Bo; Kim, Jinna; Kim, Sung Huhn

2017-07-01

To investigate the clinical significance of vibration-induced nystagmus (VIN) in unilateral vestibular asymmetry and vestibular schwannoma. Thirteen patients with vestibular schwannoma underwent the VIN test, in which stimulation was applied to the mastoid processes and sternocleidomastoid (SCM) muscles on the ipsilateral and contralateral sides of lesions. Preoperative VIN was measured, and changes in VIN were followed up for 6months after tumor removal. Significance of VIN was determined by evaluation of its sensitivity, correlation with vestibular function tests and tumor volume, and postoperative changes. The overall pre and postoperative sensitivities of VIN were 92.3% and 100%, respectively, considering stimulation at all four sites. Maximum slow-phase velocity (MSPV) of VIN was linearly correlated with caloric weakness and tumor volume, especially when stimulation was applied to the SCM muscle. Postoperative MSPV of VIN exhibited stronger linear correlation with postoperative changes in canal paresis value and inverse correlation with tumor size upon stimulation of the ipsilateral SCM muscle than upon stimulation of other sites. During the 6-month follow-up period, persistence of VIN without changes in MSPV was observed even after vestibular compensation. Evoking VIN by stimulation of the mastoid processes and SCM muscles is effective for detecting vestibular asymmetry. It could also help determine the degree of vestibular asymmetry and volume of vestibular schwannoma if stimulation is applied to the SCM muscle. The results of this study could provide clues for the basic application of VIN in patients with vestibular loss and vestibular schwannoma. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Refractory episodic vertigo: role of intratympanic gentamicin and vestibular evoked myogenic potentials.

PubMed

Celis-Aguilar, Erika; Hinojosa-González, Ramon; Vales-Hidalgo, Olivia; Coutinho-Toledo, Heloisa

Even today, the treatment of intractable vertigo remains a challenge. Vestibular ablation with intratympanic gentamicin stands as a good alternative in the management of refractory vertigo patients. To control intractable vertigo through complete saccular and horizontal canal vestibular ablation with intratympanic gentamicin treatment. Patients with refractory episodic vertigo were included. The inclusion criteria were: unilateral ear disease, moderate to profound sensorineural hearing loss, and failure to other treatments. Included patients underwent 0.5-0.8mL of gentamicin intratympanic application at a 30mg/mL concentration. Vestibular ablation was confirmed by the absence of response on cervical vestibular evoked myogenic potentials and no response on caloric tests. Audiometry, electronystagmography with iced water, and vestibular evoked myogenic potentials were performed in all patients. Ten patients were included; nine patients with Meniere's disease and one patient with (late onset) delayed hydrops. Nine patients showed an absent response on vestibular evoked myogenic potentials and no response on caloric tests. The only patient with low amplitude on cervical vestibular evoked myogenic potentials had vertigo recurrence. Vertigo control was achieved in 90% of the patients. One patient developed hearing loss >30dB. Cervical vestibular evoked myogenic potentials confirmed vestibular ablation in patients treated with intratympanic gentamicin. High-grade vertigo control was due to complete saccular and horizontal canal ablation (no response to iced water in electronystagmography and no response on cervical vestibular evoked myogenic potentials). Copyright © 2016 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Conditioned taste aversion induced by motion is prevented by selective vagotomy in the rat

NASA Technical Reports Server (NTRS)

Fox, Robert A.; Mckenna, Susan

1991-01-01

The role of the vagus nerve in motion-induced conditioned taste aversion (CTA) was studied in hooded rats. Animals with complete, selective gastric vagotomy failed to form conditioned taste aversion after multiple conditioning sessions in which the conditioned stimulus (a cider vinegar solution) was drunk immediately before a 30-min exposure to vertical axis rotation at 150 deg/s. Results are discussed with reference to the use of CTA as a measure of motion-induced 'sickness' or gastrointestinal disturbance, and because motion-induced CTA requires that both the vagus nerve and the vestibular apparatus be intact, in light of the possible convergence of vegal and vestibular functions.

Intraoperative cochlear nerve mapping with the mobile cochlear nerve compound action potential tracer in vestibular schwannoma surgery.

PubMed

Watanabe, Nobuyuki; Ishii, Takuya; Fujitsu, Kazuhiko; Kaku, Shogo; Ichikawa, Teruo; Miyahara, Kosuke; Okada, Tomu; Tanino, Shin; Uriu, Yasuhiro; Murayama, Yuichi

2018-05-18

OBJECTIVE The authors describe the usefulness and limitations of the cochlear nerve compound action potential (CNAP) mobile tracer (MCT) that they developed to aid in cochlear nerve mapping during vestibular schwannoma surgery (VSS) for hearing preservation. METHODS This MCT device requires no more than 2 seconds for stable placement on the nerve to obtain the CNAP and thus is able to trace the cochlear nerve instantaneously. Simultaneous bipolar and monopolar recording is possible. The authors present the outcomes of 18 consecutive patients who underwent preoperative useful hearing (defined as class I or II of the Gardner-Robertson classification system) and underwent hearing-preservation VSS with the use of the MCT. Mapping was considered successful when it was possible to detect and trace the cochlear nerve. RESULTS Mapping of the cochlear nerve was successful in 13 of 18 patients (72.2%), and useful hearing was preserved in 11 patients (61.1%). Among 8 patients with large tumors (Koos grade 3 or 4), the rate of successful mapping was 62.5% (5 patients). The rate of hearing preservation in patients with large tumors was 50% (4 patients). CONCLUSIONS In addition to microsurgical presumption of the arrangement of each nerve, frequent probing on and around an unidentified nerve and comparison of each waveform are advisable with the use of both more sensitive monopolar and more location-specific bipolar MCT. MCT proved to be useful in cochlear nerve mapping and may consequently be helpful in hearing preservation. The authors discuss some limitations and problems with this device.

Unilateral or bilateral vagotomy induces ovulation in both ovaries of rats with polycystic ovarian syndrome.

PubMed

Linares, Rosa; Hernández, Denisse; Morán, Carolina; Chavira, Roberto; Cárdenas, Mario; Domínguez, Roberto; Morales-Ledesma, Leticia

2013-07-17

Injecting estradiol valerate (EV) to pre-pubertal or adult female rat results in effects similar to those observed in women with polycystic ovarian syndrome (PCOS). One of the mechanisms involved in PCOS development is the hyperactivity of the sympathetic nervous system. In EV-induced PCOS rats, the unilateral sectioning of the superior ovarian nerve (SON) restores ovulation of the innervated ovary. This suggests that, in addition to the sympathetic innervation, other neural mechanisms are involved in the development/maintenance of PCOS. The aims of present study were analyze if the vagus nerve is one of the neural pathways participating in PCOS development. Ten-day old rats were injected with EV dissolved in corn oil. At 24-days of age sham-surgery, unilateral, or bilateral sectioning of the vagus nerve (vagotomy) was performed on these rats. The animals were sacrificed at 90-92 days of age, when they presented vaginal estrous preceded by a pro-estrus smear. In EV-induced PCOS rats, unilateral or bilateral vagotomy restored ovulation in both ovaries. Follicle-stimulating hormone (FSH) levels in PCOS rats with unilateral or bilateral vagotomy were lower than in control rats. This result suggests that in EV-induced PCOS rats the vagus nerve is a neural pathway participating in maintaining PCOS. The vagus nerve innervates the ovaries directly and indirectly through its synapsis in the celiac-superior-mesenteric ganglion, where the somas of neurons originating in the SON are located. Then, it is possible that vagotomy effects in EV-induced PCOS rats may be explained as a lack of communication between the central nervous system and the ovaries.

Sural nerve grafting in robotic laparoscopic radical prostatectomy: interim report.

PubMed

Mikhail, Albert A; Song, David H; Zorn, Kevin C; Orvieto, Marcelo A; Taxy, Jerome B; Lin, Shang P; Mendiola, Frederick P; Shalhav, Arieh L; Zagaja, Gregory P

2007-12-01

Sural nerve grafting for patients undergoing prostatectomy has been previously reported using open and minimally invasive methods. We report our experience with sural nerve grafting during robot-assisted laparoscopic radical prostatectomy (RLRP). Patients with preoperative potency and a minimum of 6 months follow-up were included in this prospective review. A total of 333 patients were identified between February 2003 and January 2006 who met these criteria including 22 of the 25 patients who underwent sural nerve grafting. Patients were divided into 5 groups to compare unilateral and bilateral sural nerve cohorts with non-nerve-sparing and unilateral and bilateral nerve-sparing groups. Patients were followed prospectively using health-related quality-of-life questionnaires. Twenty-two patients underwent sural nerve grafting that included three bilateral grafts. Mean follow-up was 14 months. There was no statistical difference in patients' ages, body mass index, preoperative prostate-specific antigen level, blood loss, complications, and positive margin rate. Operative time was statistically longer for both sural graft cohorts when compared with unilateral (without graft) and bilateral nerve sparing cohorts. No significant differences in subjective or objective sexual function, sexual bother, or urinary function were seen with 6 and 12 months follow-up, possibly related to smaller sural cohorts. Graft-related complications include leg pain in one patient. Sural nerve grafting during RLRP is technically feasible and safe and offers improved dexterity and visualization deep within the pelvis. However, a larger randomized cohort of patients will be required to validate any improved benefits afforded by the robot system.

Restoring tactile and erogenous penile sensation in low-spinal-lesion patients: procedural and technical aspects following 43 TOMAX nerve transfer procedures.

PubMed

Overgoor, Max L E; de Jong, Tom P V M; Kon, Moshe

2014-08-01

The "TOMAX" (TO MAX-imize sensation, sexuality, and quality of life) procedure restores genital sensation in men with low spinal lesions, improving sexual health, as shown previously. It connects the dorsal nerve of the penis to the intact ipsilateral ilioinguinal nerve, unilaterally or bilaterally. This study reports on the technical aspects based on 43 TOMAX nerve transfers. In 40 patients with no penile but intact groin sensation, 43 nerve transfers were performed. Data on patient selection, surgical history, anatomy of the ilioinguinal nerve and dorsal nerve of the penis, unilateral or bilateral surgery, surgical technique, complications, and patient information were collected prospectively. Regardless of origin, all patients with no penile but good groin sensation are eligible for the procedure, provided the ilioinguinal nerve is not damaged because of former inguinal surgery or absent because of anatomical variations. Selection of a unilateral or bilateral procedure depends on the presence or absence of reflex erections and bulbocavernosus reflex. Preliminary experience with the first three bilateral cases shows that it is technically feasible, with encouraging results. The surgical technique has evolved (described in detail, including video) to enhance outcome and reduce complications. Patients are better informed, resulting in realistic expectations. This article synthesizes the procedural and technical experience of 43 TOMAX nerve transfers. Anyone skilled in peripheral nerve surgery and microsurgery can adopt this concept and further develop it. The TOMAX procedure can then be used to restore erogenous penile sensation and improve the quality of sexual health in patients with absent penile but good groin sensation.

Evaluation of Vestibular Functions in Patients with Vogt-Koyanagi-Harada Disease.

PubMed

Fujiwara, Keishi; Morita, Shinya; Hoshino, Kimiko; Fukuda, Atsushi; Nakamaru, Yuji; Homma, Akihiro

2017-01-01

Vogt-Koyanagi-Harada (VKH) disease is an idiopathic, multisystem autoimmune disorder characterized by bilateral, diffuse granulomatous uveitis associated with neurological, audiovestibular, and dermatological manifestations. The purpose of this study is to investigate vestibular functions in patients with VKH disease. A total of 43 patients with VKH disease in Hokkaido University Hospital were enrolled in this study. Subjective symptoms such as dizziness or vertigo and the results of various vestibular examinations including nystagmus testing, caloric testing, and vestibular-evoked myogenic potential (VEMP) testing were investigated. Eight of 42 patients (19.0%) complained of subjective vestibular symptoms. On the other hand, 12 of 28 patients (42.9%) showed nystagmus, and 7 of 15 patients (46.7%) showed unilateral or bilateral weakness in the caloric test. VEMP testing was performed for 16 patients. Seven (43.8%) and 8 (50.0%) patients were evaluated as abnormal in cervical VEMP and ocular VEMP testing, respectively. The rate of detection of nystagmus was significantly higher than that of subjective symptoms. As vestibular dysfunction in patients with VKH disease cannot be detected through history taking alone, nystagmus testing, caloric testing, and VEMP testing should be performed to evaluate vestibular functions associated with VKH disease. It is considered that abnormal VEMP findings are associated with otolith organ dysfunction. © 2017 S. Karger AG, Basel.

The effect of vestibular nerve section on the expression of the hyaluronan in the frog, Rana esculenta.

PubMed

Halasi, Gábor; Wolf, Ervin; Bácskai, Tímea; Székely, György; Módis, László; Szigeti, Zsuzsa M; Mészár, Zoltán; Felszeghy, Szabolcs; Matesz, Clara

2007-12-01

Following postganglionic lesion of the eighth cranial nerve, the changes in the expression of hyaluronan (HA), one of the extracellular matrix macromolecules, were examined in the medial (MVN) and lateral (LVN) vestibular nuclei and in the entry or transitional zone (TZ) of the nerve in the frog. HA was detected in different survival times by using a specific biotinylated hyaluronan-binding probe. HA expression was defined by the area-integrated optical density (AIOD), calculated from pixel intensities of digitally captured images. During the first postoperative days the perineuronal net (PN), a HA-rich area around the neurons, was not distinguishable from the surrounding neuropil in the MVN and LVN, characterized by a bilateral drop of AIOD specifically on the operated side. From postoperative day 14 onwards AIOD increased whilst the PN reorganized. In contrast, the AIOD wobbled up and down bilaterally without any trend in the TZ. Statistical analysis indicated that AIOD changes in the structures studied ran parallel bilaterally presumably because of the operation. Our results demonstrated for the first time that (1) the lesion of the eighth cranial nerve is accompanied by the modification of AIOD reflected HA expression in the MVN, LVN and TZ, (2) different tendencies exist in the time course of AIOD in the structures studied and (3) these tendencies are similar on the intact and operated sides. Our findings may suggest an area dependent molecular mechanism of HA in the restoration of vestibular function.

Adaptation to vestibular disorientation. I, Vertigo and nystagmus following repeated clinical stimulation.

DOT National Transportation Integrated Search

1965-05-01

Forty unilateral caloric irrigations were administered in a habituation series to each of two groups of subjects. One group was tested in total darkness. Subjects in the second group were stimulated in illumination and actively attempted to control a...

Surgery for vertigo: 10-year audit from a contemporary vertigo clinic.

PubMed

Patnaik, U; Srivastava, A; Sikka, K; Thakar, A

2015-12-01

To present the profile of patients undergoing surgical treatment for vertigo at a contemporary institutional vertigo clinic. A retrospective analysis of clinical charts. The charts of 1060 patients, referred to an institutional vertigo clinic from January 2003 to December 2012, were studied. The clinical profile and long-term outcomes of patients who underwent surgery were analysed. Of 1060 patients, 12 (1.13 per cent) were managed surgically. Of these, disease-modifying surgical procedures included perilymphatic fistula repair (n = 7) and microvascular decompression of the vestibular nerve (n = 1). Labyrinth destructive procedures included transmastoid labyrinthectomy (n = 2) and labyrinthectomy with vestibular nerve section (n = 1). One patient with vestibular schwannoma underwent both a disease-modifying and destructive procedure (translabyrinthine excision). All patients achieved excellent vertigo control, classified as per the American Academy of Otolaryngology - Head and Neck Surgery 1995 criteria. With the advent of intratympanic treatments, surgical treatments for vertigo have become further limited. However, surgery with directed intent, in select patients, can give excellent results.

Interaction between Vestibular Compensation Mechanisms and Vestibular Rehabilitation Therapy: 10 Recommendations for Optimal Functional Recovery

PubMed Central

Lacour, Michel; Bernard-Demanze, Laurence

2015-01-01

This review questions the relationships between the plastic events responsible for the recovery of vestibular function after a unilateral vestibular loss (vestibular compensation), which has been well described in animal models in the last decades, and the vestibular rehabilitation (VR) therapy elaborated on a more empirical basis for vestibular loss patients. The main objective is not to propose a catalog of results but to provide clinicians with an understandable view on when and how to perform VR therapy, and why VR may benefit from basic knowledge and may influence the recovery process. With this perspective, 10 major recommendations are proposed as ways to identify an optimal functional recovery. Among them are the crucial role of active and early VR therapy, coincidental with a post-lesion sensitive period for neuronal network remodeling, the instructive role that VR therapy may play in this functional reorganization, the need for progression in the VR therapy protocol, which is based mainly on adaptation processes, the necessity to take into account the sensorimotor, cognitive, and emotional profile of the patient to propose individual or “à la carte” VR therapies, and the importance of motivational and ecologic contexts. More than 10 general principles are very likely, but these principles seem crucial for the fast recovery of vestibular loss patients to ensure good quality of life. PMID:25610424

Evaluation of vestibular functions in children with vertigo attacks

PubMed Central

Uneri, A; Turkdogan, D

2003-01-01

Aim: To examine vestibular system functions in children with episodic vertigo attacks. Methods: Thirty four children (20 males) aged 4–18 years with paroxysmal dizziness and/or vertigo attacks were evaluated. A medical history for vestibular symptoms and migraine was taken. Vestibular and auditory functions were assessed. Results: Chronic headache attacks consistent with migraine were reported in 12 children and motion sickness was reported in 30. Family history in first degree relatives was positive for migraine in 29 children and for episodic vertigo in 22. Electronystagmography and videonystagmography showed two types of nystagmus: spontaneous vestibular nystagmus (41%) and benign paroxysmal positional nystagmus (BPPN) (59%). The first type of nystagmus was assessed as a sign of vestibulopathy and the patients with BPPN were diagnosed as having benign paroxysmal positional vertigo (BPPV). Audiometric examination in four cases revealed bilateral sensory neural hearing loss in low frequencies. Pure tone averages in 30 cases were within normal ranges; however low frequencies in 28 of them were approximately 10 dB lower than high frequencies. Unilateral caloric responses diminished in eight children. Conclusions: Peripheral vestibular problems in childhood present in a wide spectrum, which varies from a short episode of dizziness to a typical vestibular attack with fluctuating sensory neural hearing loss or episodes of BPPV. A considerable number of these vestibular problems might be related to the migraine syndrome. PMID:12765917

Unilateral occipital nerve stimulation for bilateral occipital neuralgia: a case report and literature review

PubMed Central

Liu, Aijun; Jiao, Yongcheng; Ji, Huijun; Zhang, Zhiwen

2017-01-01

Objectives The aim of this study is to present a case of successful relief of bilateral occipital neuralgia (ON) using unilateral occipital nerve stimulation (ONS) and to discuss the possible underlying mechanisms. Materials and methods We present the case of a 59-year-old female patient with severe bilateral ON treated with unilateral ONS. We systematically reviewed previous studies of ONS for ON, discussing the possible mechanisms of ONS in the relief of ON. Results The patient reported complete pain relief after consistent unilateral ONS during the follow-up period. The underlying mechanisms may be linked to the relationship between pain and several brain regions, including the pons, midbrain, and periaqueductal gray. Conclusion ONS is an effective and safe option for treating ON. Future studies will be required to clarify the mechanisms by which unilateral occipital stimulation provided relief for bilateral neuralgia in this case. PMID:28176938

Unilateral occipital nerve stimulation for bilateral occipital neuralgia: a case report and literature review.

PubMed

Liu, Aijun; Jiao, Yongcheng; Ji, Huijun; Zhang, Zhiwen

2017-01-01

The aim of this study is to present a case of successful relief of bilateral occipital neuralgia (ON) using unilateral occipital nerve stimulation (ONS) and to discuss the possible underlying mechanisms. We present the case of a 59-year-old female patient with severe bilateral ON treated with unilateral ONS. We systematically reviewed previous studies of ONS for ON, discussing the possible mechanisms of ONS in the relief of ON. The patient reported complete pain relief after consistent unilateral ONS during the follow-up period. The underlying mechanisms may be linked to the relationship between pain and several brain regions, including the pons, midbrain, and periaqueductal gray. ONS is an effective and safe option for treating ON. Future studies will be required to clarify the mechanisms by which unilateral occipital stimulation provided relief for bilateral neuralgia in this case.

Vestibular function outcomes after vestibular neurectomy in Meniere disease: can vestibular neurectomy provide complete vestibular deafferentation?

PubMed

Leveque, M; Seidermann, L; Tran, H; Langagne, T; Ulmer, E; Chays, A

2010-06-01

Vestibular neurectomy is considered the reference treatment of incapacitating vertigo accompanying Meniere disease, with an efficiency rate of 85-95% in most literature reports. The aim of this study is to evaluate if vestibular neurectomy can provide a complete vestibular deafferentation by investigating complete vestibular function after surgery. Prospective study. Twenty-four patients suffering from incapacitated Meniere vertigo crisis beneficiated from a vestibular neurectomy by retrosigmoid approach. The average time between surgery and vestibular evaluation was 1 year. We performed (i) kinetic test, (ii) caloric test and (iii) vibration-induced nystagmus (VIN) at 30, 60 and 100Hz under videonystagmography recording, (iv) vestibular evoked myogenic potentials (VEMP), (v) video head impulsed test (VHIT) for each semicircular canals and (vi) an evaluation of visual vertical and horizontal subjective (VVS and HVS). On clinical evaluation, all the patients except one had never experienced any recurrence of vertigo crisis after surgery. The 24 patients would definitely undergo the surgery again. On vestibular evaluation, on the operated side, all patients showed a total areflexia at caloric test; 23 patients had no VEMP response; 23 patients had abolished canals response to VHIT. All the patients had VVS and HVS deviated towards the operated side; 23 patients had a high velocity VIN from 30 to 60Hz. This study proves that vestibular neurectomy can provide a complete vestibular deafferentation. We discuss this vestibular evaluation protocol and the main difficulties encounter during surgery, which could lead to partial nerve section and partial relief, and explain residual vestibular function after vestibular neurectomy. Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.

Isolated cochlear neuritis from varicella reactivation mimicking a vestibular schwannoma.

PubMed

Goodale, Adam D; Golub, Justin S; Cornelius, Rebecca S; Samy, Ravi N

2016-09-01

We present a case of a patient with progressive unilateral sensorineural hearing loss and tinnitus with internal auditory canal enhancement on magnetic resonance imaging (MRI) secondary to isolated cochlear neuritis from varicella reactivation. MRI following antiviral treatment showed resolution of enhancement. Varicella reactivation is commonly seen in the form of Ramsay Hunt syndrome, which is known to produce abnormal MRI enhancement from facial and vestibulocochlear neuritis; however, its characteristic clinical signs aid the diagnosis. This case is unique in that the only manifestation of varicella infection was unilateral hearing loss. This case outlines the importance of maintaining a broad differential diagnosis in the evaluation of unilateral hearing loss as well as recognizing the limited specificity of MRI.

Rapid compensatory changes in GABA receptor efficacy in rat vestibular neurones after unilateral labyrinthectomy

PubMed Central

Yamanaka, Toshiaki; Him, Aydin; Cameron, Susan A; Dutia, Mayank B

2000-01-01

The inhibitory effects of the GABAA agonist muscimol and the GABAB agonist baclofen on tonically active medial vestibular nucleus (MVN) neurones were recorded in slices of the rat dorsal brainstem in vitro, to determine whether any changes occurred in the functional efficacy of GABAergic inhibition in these cells during the initial rapid stage of ‘vestibular compensation’, the behavioural recovery that takes place after unilateral labyrinthectomy (UL). These experiments were carried out in preparations where the midline was cut, severing all commissural connections between the two vestibular nuclei. Slices of the MVN were prepared from normal animals and animals that had been unilaterally labyrinthectomised 4 h earlier. The mean in vitro discharge rate of MVN neurones in the rostral region of the ipsi-lesional nucleus after UL was significantly higher than that in control slices, confirming our earlier reports of an increase in intrinsic excitability of these cells in the early stage of vestibular compensation. The in vitro discharge rates of caudal ipsi-lesional MVN cells, and rostral and caudal contra-lesional MVN cells, were not different from controls. Muscimol and baclofen caused reversible, dose-related inhibition of the tonic discharge rate of MVN cells in control slices. In slices prepared from UL animals, MVN cells in the rostral region of the ipsi-lesional nucleus showed a marked downregulation of their response to both muscimol and baclofen, seen as a rightward shift and a decrease in slope of the dose-response relationships for the two agonists. In the contra-lesional nucleus, there was a small but significant upregulation of the responsiveness of both rostral and caudal MVN cells to baclofen, and a marked upregulation of the responsiveness of caudal MVN cells to muscimol. In slices from animals that had undergone bilateral labyrinthectomy 4 h earlier, the downregulation of the functional efficacy of GABA receptors in the rostral MVN cells did not occur. The changes in GABA receptor efficacy after UL are therefore not due to the vestibular de-afferentation itself, but are instead due to the imbalance in excitability of the vestibular nuclei of the lesioned and intact sides, and the enhanced commissural inhibition of the ipsi-lesional MVN cells that follows UL. The downregulation of GABA receptor efficacy in the ipsi-lesional MVN neurones is functionally compensatory, in that their response to commissural and cerebellar inhibitory drive will be significantly reduced after UL. Their intrinsic membrane conductances, and their remaining excitatory synaptic inputs, will consequently be more effective in causing depolarisation and the restoration of resting activity. Simultaneously the upregulation of GABAergic efficacy in the contra-lesional MVN will tend to reduce the hyperactivity on the contralateral side. These adaptive changes therefore represent a plausible cellular mechanism for the recovery of resting discharge in the ipsi-lesional MVN neurones, and the ‘re-balancing’ of the excitability of the vestibular neurones of the lesioned and intact sides, as occurs after UL in vivo. We propose that the adaptive regulation of the functional efficacy of GABA receptors in the MVN neurones may be an important cellular mechanism for the ‘homeostasis of bilateral excitability’ of the vestibular nuclei of the two sides. PMID:10699085

Organization of projections from the raphe nuclei to the vestibular nuclei in rats

NASA Technical Reports Server (NTRS)

Halberstadt, A. L.; Balaban, C. D.

2003-01-01

Previous anatomic and electrophysiological evidence suggests that serotonin modulates processing in the vestibular nuclei. This study examined the organization of projections from serotonergic raphe nuclei to the vestibular nuclei in rats. The distribution of serotonergic axons in the vestibular nuclei was visualized immunohistochemically in rat brain slices using antisera directed against the serotonin transporter. The density of serotonin transporter-immunopositive fibers is greatest in the superior vestibular nucleus and the medial vestibular nucleus, especially along the border of the fourth ventricle; it declines in more lateral and caudal regions of the vestibular nuclear complex. After unilateral iontophoretic injections of Fluoro-Gold into the vestibular nuclei, retrogradely labeled neurons were found in the dorsal raphe nucleus (including the dorsomedial, ventromedial and lateral subdivisions) and nucleus raphe obscurus, and to a minor extent in nucleus raphe pallidus and nucleus raphe magnus. The combination of retrograde tracing with serotonin immunohistofluorescence in additional experiments revealed that the vestibular nuclei receive both serotonergic and non-serotonergic projections from raphe nuclei. Tracer injections in densely innervated regions (especially the medial and superior vestibular nuclei) were associated with the largest numbers of Fluoro-Gold-labeled cells. Differences were observed in the termination patterns of projections from the individual raphe nuclei. Thus, the dorsal raphe nucleus sends projections that terminate predominantly in the rostral and medial aspects of the vestibular nuclear complex, while nucleus raphe obscurus projects relatively uniformly throughout the vestibular nuclei. Based on the topographical organization of raphe input to the vestibular nuclei, it appears that dense projections from raphe nuclei are colocalized with terminal fields of flocculo-nodular lobe and uvula Purkinje cells. It is hypothesized that raphe-vestibular connections are organized to selectively modulate processing in regions of the vestibular nuclear complex that receive input from specific cerebellar zones. This represents a potential mechanism whereby motor activity and behavioral arousal could influence the activity of cerebellovestibular circuits.

Neuroactive substances in the human vestibular end organs.

PubMed

Usami, S; Matsubara, A; Shinkawa, H; Matsunaga, T; Kanzaki, J

1995-01-01

In order to evaluate the involvement of neuroactive substances in the human vestibular periphery, the immunocytochemical distribution of substance P (SP), calcitonin gene-related peptide (CGRP), and choline acetyltransferase (ChAT) was examined. SP-like immunoreactivity (LI) was present around and beneath sensory hair cells, probably corresponding to their afferent nerve endings. SP-LI was found predominantly in subpopulations of the primary afferents distributed in the peripheral region of the end organs. ChAT-LI and CGRP-LI were found throughout as small puncta below the hair cell layer, probably corresponding to efferent endings. The present results indicate that these neuroactive substances, previously described in animals, are also distributed in the human vestibular periphery, and almost certainly contribute to human vestibular function.

Functional organization of primate translational vestibulo-ocular reflexes and effects of unilateral labyrinthectomy

NASA Technical Reports Server (NTRS)

Angelaki, D. E.; McHenry, M. Q.; Newlands, S. D.; Dickman, J. D.

1999-01-01

Translational vestibulo-ocular reflexes (trVORs) are characterized by distinct spatio-temporal properties and sensitivities that are proportional to the inverse of viewing distance. Anodal (inhibitory) labyrinthine stimulation (100 microA, < 2 s) during motion decreased the high-pass filtered dynamics, as well as horizontal trVOR sensitivity and its dependence on viewing distance. Cathodal (excitatory) currents had opposite effects. Translational VORs were also affected after unilateral labyrinthectomy. Animals lost their ability to modulate trVOR sensitivity as a function of viewing distance acutely after the lesion. These deficits partially recovered over time, albeit a significant reduction in trVOR sensitivity as a function of viewing distance remained in compensated animals. During fore-aft motion, the effects of unilateral labyrinthectomy were more dramatic. Both acute and compensated animals permanently lost their ability to modulate fore-aft trVOR responses as a function of target eccentricity. These results suggest that (1) the dynamics and viewing distance-dependent properties of the trVORs are very sensitive to changes in the resting firing rate of vestibular afferents and, consequently, vestibular nuclei neurons; (2) the most irregularly firing primary otolith afferents that are most sensitive to labyrinthine electrical stimulation might contribute to reflex dynamics and sensitivity; (3) inputs from both labyrinths are necessary for the generation of the translational VORs.

Single Fraction Versus Fractionated Linac-Based Stereotactic Radiotherapy for Vestibular Schwannoma: A Single-Institution Experience

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

Collen, Christine, E-mail: ccollen@uzbrussel.be; Ampe, Ben; Gevaert, Thierry

2011-11-15

Purpose: To evaluate and compare outcomes for patients with vestibular schwannoma (VS) treated in a single institution with linac-based stereotactic radiosurgery (SRS) or by fractionated stereotactic radiotherapy (SRT). Methods and Materials: One hundred and nineteen patients (SRS = 78, SRT = 41) were treated. For both SRS and SRT, beam shaping is performed by a mini-multileaf collimator. For SRS, a median single dose of 12.5 Gy (range, 11-14 Gy), prescribed to the 80% isodose line encompassing the target, was applied. Of the 42 SRT treatments, 32 treatments consisted of 10 fractions of 3-4 Gy, and 10 patients received 25 sessionsmore » of 2 Gy, prescribed to the 100% with the 95% isodose line encompassing the planning target volume. Mean largest tumor diameter was 16.6 mm in the SRS and 24.6 mm in the SRT group. Local tumor control, cranial nerve toxicity, and preservation of useful hearing were recorded. Any new treatment-induced cranial nerve neuropathy was scored as a complication. Results: Median follow-up was 62 months (range, 6-136 months), 5 patients progressed, resulting in an overall 5-year local tumor control of 95%. The overall 5-year facial nerve preservation probability was 88% and facial nerve neuropathy was statistically significantly higher after SRS, after prior surgery, for larger tumors, and in Koos Grade {>=}3. The overall 5-year trigeminal nerve preservation probability was 96%, not significantly influenced by any of the risk factors. The overall 4-year probability of preservation of useful hearing (Gardner-Robertson score 1 or 2) was 68%, not significantly different between SRS or SRT (59% vs. 82%, p = 0.089, log rank). Conclusion: Linac-based RT results in good local control and acceptable clinical outcome in small to medium-sized vestibular schwannomas (VSs). Radiosurgery for large VSs (Koos Grade {>=}3) remains a challenge because of increased facial nerve neuropathy.« less

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

PubMed

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

2018-05-02

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

Preservation of auditory and vestibular function after surgical removal of bilateral vestibular schwannomas in a patient with neurofibromatosis type 2

NASA Technical Reports Server (NTRS)

Black, F. O.; Brackmann, D. E.; Hitselberger, W. E.; Purdy, J.

1995-01-01

The outcome of acoustic neuroma (vestibular schwannoma) surgery continues to improve rapidly. Advances can be attributed to several fields, but the most important contributions have arisen from the identification of the genes responsible for the dominant inheritance of neurofibromatosis types 1 (NF1) and 2 (NF2) and the development of magnetic resonance imaging with gadolinium enhancement for the early anatomic confirmation of the pathognomonic, bilateral vestibular schwannomas in NF2. These advances enable early diagnosis and treatment when the tumors are small in virtually all subjects at risk for NF2. The authors suggest that advising young NF2 patients to wait until complications develop, especially hearing loss, before diagnosing and operating for bilateral eighth nerve schwannomas may not always be in the best interest of the patient. To the authors' knowledge, this is the first reported case of preservation of both auditory and vestibular function in a patient after bilateral vestibular schwannoma excision.

An experimental vestibular neural prosthesis: design and preliminary results with rhesus monkeys stimulated with modulated pulses.

PubMed

Nie, Kaibao; Ling, Leo; Bierer, Steven M; Kaneko, Chris R S; Fuchs, Albert F; Oxford, Trey; Rubinstein, Jay T; Phillips, James O

2013-06-01

A vestibular neural prosthesis was designed on the basis of a cochlear implant for treatment of Meniere's disease and other vestibular disorders. Computer control software was developed to generate patterned pulse stimuli for exploring optimal parameters to activate the vestibular nerve. Two rhesus monkeys were implanted with the prototype vestibular prosthesis and they were behaviorally evaluated post implantation surgery. Horizontal and vertical eye movement responses to patterned electrical pulse stimulations were collected on both monkeys. Pulse amplitude modulated (PAM) and pulse rate modulated (PRM) trains were applied to the lateral canal of each implanted animal. Robust slow-phase nystagmus responses following the PAM or PRM modulation pattern were observed in both implanted monkeys in the direction consistent with the activation of the implanted canal. Both PAM and PRM pulse trains can elicit a significant amount of in-phase modulated eye velocity changes and they could potentially be used for efficiently coding head rotational signals in future vestibular neural prostheses.

Acoustic Neuroma Mimicking Orofacial Pain: A Unique Case Report

PubMed Central

Srinivas, Naveen; Mendigeri, Vijaylaxmi; Puranik, Surekha R.

2016-01-01

Acoustic neuroma (AN), also called vestibular schwannoma, is a tumor composed of Schwann cells that most frequently involve the vestibular division of the VII cranial nerve. The most common symptoms include orofacial pain, facial paralysis, trigeminal neuralgia, tinnitus, hearing loss, and imbalance that result from compression of cranial nerves V–IX. Symptoms of acoustic neuromas can mimic and present as temporomandibular disorder. Therefore, a thorough medical and dental history, radiographic evaluation, and properly conducted diagnostic testing are essential in differentiating odontogenic pain from pain that is nonodontogenic in nature. This article reports a rare case of a young pregnant female patient diagnosed with an acoustic neuroma located in the cerebellopontine angle that was originally treated for musculoskeletal temporomandibular joint disorder. PMID:28053796

Mobile phones: influence on auditory and vestibular systems.

PubMed

Balbani, Aracy Pereira Silveira; Montovani, Jair Cortez

2008-01-01

Telecommunications systems emit radiofrequency, which is an invisible electromagnetic radiation. Mobile phones operate with microwaves (450900 MHz in the analog service, and 1,82,2 GHz in the digital service) very close to the users ear. The skin, inner ear, cochlear nerve and the temporal lobe surface absorb the radiofrequency energy. literature review on the influence of cellular phones on hearing and balance. systematic review. We reviewed papers on the influence of mobile phones on auditory and vestibular systems from Lilacs and Medline databases, published from 2000 to 2005, and also materials available in the Internet. Studies concerning mobile phone radiation and risk of developing an acoustic neuroma have controversial results. Some authors did not see evidences of a higher risk of tumor development in mobile phone users, while others report that usage of analog cellular phones for ten or more years increase the risk of developing the tumor. Acute exposure to mobile phone microwaves do not influence the cochlear outer hair cells function in vivo and in vitro, the cochlear nerve electrical properties nor the vestibular system physiology in humans. Analog hearing aids are more susceptible to the electromagnetic interference caused by digital mobile phones. there is no evidence of cochleo-vestibular lesion caused by cellular phones.

Posterior insular cortex - a site of vestibular-somatosensory interaction?

PubMed

Baier, Bernhard; Zu Eulenburg, Peter; Best, Christoph; Geber, Christian; Müller-Forell, Wibke; Birklein, Frank; Dieterich, Marianne

2013-09-01

Background In previous imaging studies the insular cortex (IC) has been identified as an essential part of the processing of a wide spectrum of perception and sensorimotor integration. Yet, there are no systematic lesion studies in a sufficient number of patients examining whether processing of vestibular and the interaction of somatosensory and vestibular signals take place in the IC. Methods We investigated acute stroke patients with lesions affecting the IC in order to fill this gap. In detail, we explored signs of a vestibular tone imbalance such as the deviation of the subjective visual vertical (SVV). We applied voxel-lesion behaviour mapping analysis in 27 patients with acute unilateral stroke. Results Our data demonstrate that patients with lesions of the posterior IC have an abnormal tilt of SVV. Furthermore, re-analysing data of 20 patients from a previous study, we found a positive correlation between thermal perception contralateral to the stroke and the severity of the SVV tilt. Conclusions We conclude that the IC is a sensory brain region where different modalities might interact.

Brain stem and inner ear abnormalities in children with auditory neuropathy spectrum disorder and cochlear nerve deficiency.

PubMed

Huang, B Y; Roche, J P; Buchman, C A; Castillo, M

2010-11-01

Cranial abnormalities, including CND, are common in children with ANSD. The purpose of this study was to assess whether CND is associated with brain or inner ear abnormalities in a cohort of children with ANSD. Two neuroradiologists retrospectively reviewed cranial MR imaging examinations in 103 children with ANSD. Brain, cochlear nerve, and temporal bone abnormalities were described and tabulated. Findings were stratified on the basis of the presence and laterality of CND, and differences in the presence of associated inner ear or intracranial abnormalities were assessed by using 2-tailed Fisher exact tests. CND was identified in 33.0% of children and 26.9% of ears with ANSD. Significantly more patients with bilateral CND had intracranial abnormalities than those with unilateral CND (60.0% versus 15.8%; P = .012). Forty percent of patients with bilateral CND, 0% of patients with unilateral CND, and 10.1% of those without CND demonstrated hindbrain malformations. Patients with bilateral CND were more likely to demonstrate hindbrain malformations than patients with normal nerves (P = .01) or unilateral CND (P = .004). Labyrinthine abnormalities were significantly more common in patients with bilateral CND than in those without CND (P ≤ .001). Cochlear anomalies were more common in patients with bilateral versus unilateral CND (P = .01). IAC and cochlear aperture stenosis were more common in those with unilateral and bilateral CND than those without CND (both P < .001). Cochlear and hindbrain abnormalities are significantly more common among patients with ANSD with bilateral CND compared with those with at least 1 intact cochlear nerve.

Morphological changes in the cervical intervertebral foramen dimensions with unilateral facet joint dislocation.

PubMed

Ebraheim, Nabil A; Liu, Jiayong; Ramineni, Satheesh K; Liu, Xiaochen; Xie, Joe; Hartman, Ryan G; Goel, Vijay K

2009-11-01

Many investigators have conducted studies to determine the biomechanics, causes, complications and treatment of unilateral facet joint dislocation in the cervical spine. However, there is no quantitative data available on morphological changes in the intervertebral foramen of the cervical spine following unilateral facet joint dislocation. These data are important to understand the cause of neurological compromise following unilateral facet joint dislocation. Eight embalmed human cadaver cervical spine specimens ranging from level C1-T1 were used. The nerve roots of these specimens at C5-C6 level were marked by wrapping a 0.12mm diameter wire around them. Unilateral facet dislocation at C5-C6 level was simulated by serially sectioning the corresponding ligamentous structures. A CT scan of the specimens was obtained before and after the dislocation was simulated. A sagittal plane through the centre of the pedicle and facet joint was constructed and used for measurement. The height and area of the intervertebral foramen, the facet joint space, nerve root diameter and area, and vertebral alignment both before and after dislocation were evaluated. The intervertebral foramen area changed from 50.72+/-0.88mm(2) to 67.82+/-4.77mm(2) on the non-dislocated side and from 41.39+/-1.11mm(2) to 113.77+/-5.65mm(2) on the dislocated side. The foraminal heights changed from 9.02+/-0.30mm to 10.52+/-0.50mm on the non-dislocated side and 10.43+/-0.50mm to 17.04+/-0.96mm on the dislocated side. The facet space area in the sagittal plane changed from 6.80+/-0.80mm(2) to 40.02+/-1.40mm(2) on the non-dislocated side. The C-5 anterior displacement showed a great change from 0mm to 5.40+/-0.24mm on the non-dislocated side and from 0mm to 3.42+/-0.20mm on the dislocated side. Neither of the nerve roots on either side showed a significant change in size. The lack of change in nerve root area indicates that the associated nerve injury with unilateral facet joint dislocation is probably due to distraction rather than due to direct nerve root compression.

Preoperative vestibular assessment protocol of cochlear implant surgery: an analytical descriptive study.

PubMed

Bittar, Roseli Saraiva Moreira; Sato, Eduardo Setsuo; Ribeiro, Douglas Jósimo Silva; Tsuji, Robinson Koji

Cochlear implants are undeniably an effective method for the recovery of hearing function in patients with hearing loss. To describe the preoperative vestibular assessment protocol in subjects who will be submitted to cochlear implants. Our institutional protocol provides the vestibular diagnosis through six simple tests: Romberg and Fukuda tests, assessment for spontaneous nystagmus, Head Impulse Test, evaluation for Head Shaking Nystagmus and caloric test. 21 patients were evaluated with a mean age of 42.75±14.38 years. Only 28% of the sample had all normal test results. The presence of asymmetric vestibular information was documented through the caloric test in 32% of the sample and spontaneous nystagmus was an important clue for the diagnosis. Bilateral vestibular areflexia was present in four subjects, unilateral arreflexia in three and bilateral hyporeflexia in two. The Head Impulse Test was a significant indicator for the diagnosis of areflexia in the tested ear (p=0.0001). The sensitized Romberg test using a foam pad was able to diagnose severe vestibular function impairment (p=0.003). The six clinical tests were able to identify the presence or absence of vestibular function and function asymmetry between the ears of the same individual. Copyright © 2016 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Noise-induced hearing loss: neuropathic pain via Ntrk1 signaling

PubMed Central

Manohar, Senthilvelan; Dahar, Kimberly; Adler, Henry J.; Dalian, Ding; Salvi, Richard

2016-01-01

Severe noise-induced damage to the inner ear leads to auditory nerve fiber degeneration thereby reducing the neural input to the cochlear nucleus (CN). Paradoxically, this leads to a significant increase in spontaneous activity in the CN which has been linked to tinnitus, hyperacusis and ear pain. The biological mechanisms that lead to an increased spontaneous activity are largely unknown, but could arise from changes in glutamatergic or GABAergic neurotransmission or neuroinflammation. To test this hypothesis, we unilaterally exposed rats for 2 h to a 126 dB SPL narrow band noise centered at 12 kHz. Hearing loss measured by auditory brainstem responses exceeded 55 dB from 6 to 32 kHz. The mRNA from the exposed CN was harvested at 14 or 28 days post-exposure and qRT-PCR analysis was performed on 168 genes involved in neural inflammation, neuropathic pain and glutamatergic or GABAergic neurotransmission. Expression levels of mRNA of Slc17a6 and Gabrg3, involved in excitation and inhibition respectively, were significantly increased at 28 days post-exposure, suggesting a possible role in the CN spontaneous hyperactivity associated with tinnitus and hyperacusis. In the pain and inflammatory array, noise exposure up-regulated mRNA expression levels of four pain/inflammatory genes, Tlr2, Oprd1, Kcnq3 and Ntrk1 and decreased mRNA expression levels of two more genes, Ccl12 and Il1β. Pain/inflammatory gene expression changes via Ntrk1 signaling may induce sterile inflammation, neuropathic pain, microglial activation and migration of nerve fibers from the trigeminal nerve and cuneate and vestibular nuclei into the CN. These changes could contribute to somatic tinnitus, hyperacusis and otalgia. PMID:27473923

Thermometric diagnosis of peripheral nerve injuries. Assessment of the diagnostic accuracy of a new practical technique.

PubMed

Ya'ish, F M M; Cooper, J P; Craigen, M A C

2007-07-01

The diagnosis of nerve injury using thermotropic liquid crystal temperature strips was compared blindly and prospectively against operative findings in 36 patients requiring surgical exploration for unilateral upper limb lacerations with suspected nerve injury. Thermotropic liquid crystal strips were applied to affected and non-affected segments in both hands in all subjects. A pilot study showed that a simple unilateral laceration without nerve injury results in a cutaneous temperature difference between limbs, but not within each limb. Thus, for detection of a nerve injury, comparison was made against the unaffected nerve distribution in the same hand. Receiver operating characteristic curve analysis showed that an absolute temperature difference > or = 1.0 degrees C was diagnostic of a nerve injury (area under the curve = 0.985, sensitivity = 100%, specificity = 93.8%). Thermotropic liquid crystal strip assessment is a new, reliable and objective method for the diagnosis of traumatic peripheral nerve injuries. If implemented in the acute setting, it could improve the reliability of clinical assessment and reduce the number of negative surgical explorations.

Upregulation of Ryk expression in rat dorsal root ganglia after peripheral nerve injury.

PubMed

Li, Xin; Li, Yao-hua; Yu, Shun; Liu, Yaobo

2008-10-22

To study changes of Ryk expression in dorsal root ganglia (DRG) after peripheral nerve injury, we set up an animal model of unilateral sciatic nerve lesioned rats. Changes of Ryk protein expression in DRG neurons after unilateral sciatic nerve injury were investigated by immunostaining. Changes of Ryk mRNA were also tested by semi-quantitative PCR concurrently. We found, both at the level of protein and mRNA, that Ryk could be induced in cells of ipsilateral DRG after unilateral sciatic nerve lesion. Further investigation by co-immunostaining confirmed that the Ryk-immunoreactive (Ryk-IR) cells were NeuN-immunoreactive (NeuN-IR) neurons of DRG. We also showed the pattern of Ryk induction in DRG neurons after sciatic nerve injury: the number of Ryk IR neurons peaked at 2 weeks post-lesion and decreased gradually by 3 weeks post-lesion. The proportions of different sized Ryk IR neurons were also observed and counted at various stages after nerve lesion. Analysis of Ryk mRNA by RT-PCR showed the same induction pattern as by immunostaining. Ryk mRNA was not expressed in normal or contralateral DRG, but was expressed 1, 2 and 3 weeks post-lesion in the ipsilateral DRG. Ryk mRNA levels increased slightly from 1 to 2 weeks, decreased then by 3 weeks post-lesion. These results indicate that Ryk might be involved in peripheral nerve plasticity after injury. This is a novel function apart from its well-known fundamental activity as a receptor mediating axon guidance and outgrowth.

Microvascular Decompression for Treatment of Trigeminal Neuralgia in Patient with Facial Nerve Schwannoma.

PubMed

Marinelli, John P; Van Gompel, Jamie J; Link, Michael J; Carlson, Matthew L

2018-05-01

Secondary trigeminal neuralgia (TN) is uncommon. When a space-occupying lesion with mass effect is identified, the associated TN is often exclusively attributed to the tumor. This report illustrates the importance of considering coexistent actionable pathology when surgically treating secondary TN. A 51-year-old woman presented with abrupt-onset TN of the V2 and V3 nerve divisions with hypesthesia. She denied changes in hearing, balance, or facial nerve dysfunction. Magnetic resonance imaging revealed a 1.6-cm contrast-enhancing cerebellopontine angle tumor that effaced the trigeminal nerve, consistent with a vestibular schwannoma. In addition, a branch of the superior cerebellar artery abutted the cisternal segment of the trigeminal nerve on T2-weighted thin-slice magnetic resonance imaging. Intraoperative electrical stimulation of the tumor elicited a response from the facial nerve at low threshold over the entire accessible tumor surface, indicating that the tumor was a facial nerve schwannoma. Considering the patient's lack of facial nerve deficit and that the tumor exhibited no safe entry point for intracapsular debulking, tumor resection was not performed. Working between the tumor and tentorium, a branch of the superior cerebellar artery was identified and decompressed with a Teflon pad. At last follow-up, the patient exhibited resolution of her TN. Her hearing and facial nerve function remained intact. Despite obstruction from a medium-sized tumor, it is still possible to achieve microvascular decompression of the fifth cranial nerve. This emphasizes the importance of considering other actionable pathology during surgical management of presumed tumor-induced TN. Further, TN is relatively uncommon with medium-sized vestibular schwannomas and coexistent causes should be considered. Copyright © 2018 Elsevier Inc. All rights reserved.

Glioneuronal Heterotopia Presenting As a Cerebellopontine angle Tumor of the cranial Nerve VIII, Case Report.

PubMed

Peris-Celda, M; Giannini, C; Diehn, F E; Eckel, L J; Neff, B A; Van Gompel, J J

2018-04-03

Vestibular schwannomas and meningiomas account for the great majority of lesions arising in the cerebellopontine angle (CPA). In this report, we present a case of glioneuronal heterotopia, also known as glioneuronal hamartoma, arising from the VIII cranial nerve, which is an extremely uncommon lesion. Important radiologic and surgical aspects are reviewed, which may help in early recognition and intraoperative decision making when these lesions are encountered. A healthy 29-year-old female presented with intermittent right facial numbness. Magnetic resonance imaging (MRI) showed an incidental minimally enhancing cerebellopontine angle lesion on the right VII-VIII cranial nerve complex. The patient declined serial observation and opted for operative intervention for resection. Intraoperatively, the lesion resembled neural tissue and was continuous with the VIII cranial nerve. Pathological analysis demonstrated mature glioneuronal tissue consistent with hamartomatous brain tissue. The patient maintained normal hearing and facial nerve function after surgery. Radiologic, surgical and pathological characteristics are described. Ectopic glioneuronal tissue of the VIII cranial nerve is a rare non-neoplastic lesion, and should be considered in the differential diagnosis of unusual appearing intracanalicular and cerebellopontine angle lesions. The congenital and benign nature of this entity makes observation a valid option for these cases, although they are so infrequent that they are often presumptively managed as vestibular schwannomas. Attempts to radically resect these lesions may result in higher rates of hearing loss or facial palsy due to their continuity with the cranial nerves. Copyright © 2018 Elsevier Inc. All rights reserved.

Surgical management of internal auditory canal and cerebellopontine angle facial nerve schwannoma

PubMed Central

Mowry, Sarah; Hansen, Marlan; Gantz, Bruce

2013-01-01

Objective To investigate the long-term patient outcomes following tumor debulking for internal auditory canal facial schwannoma (FNS). Study Design retrospective case review Setting Tertiary referral center Patients Patients operated on between 1998–2010 for a preoperative diagnosis of vestibular schwannoma with the intraoperative identification FNS instead. Intervention diagnostic and therapeutic Main Outcome Measures House-Brackmann facial nerve score immediately and at long term follow up (>1 yr); recurrence of tumor. Results 16 patients were identified who were presumed to have vestibular schwannoma but intraoperatively were diagnosed with facial nerve schwannoma. Eleven underwent debulking surgery (67%–99% tumor removal), 2 underwent decompression only, 2 were diagnosed with nervus intermedius tumors and had total tumor removal with preservation of the motor branch of CN VII, 1 had complete tumor removal with facial nerve grafting. Five of 11 debulking patients underwent the MCF approach for tumor removal; the remainder had translabyrinthine resections. One debulking patient was lost to follow-up. Nine of 10 patients with long term follow up had H/B grade I or II facial function. One patient had recurrence of the tumor that required revision surgery with total removal and facial nerve grafting. Conclusions Tumor debulking for FNS provides an opportunity for tumor removal and excellent facial nerve function. Continuous facial nerve monitoring is vital for successful debulking surgery. FNS debulking is feasible via the MCF approach. Serial postoperative imaging is warranted to monitor for recurrence. PMID:22772011

[Study of the structure of receptor organs of the vestibular apparatus of rats after space flight on "Kosmos-1667"].

PubMed

Lychakov, D V; Pashchinin, A N; Boiadzhieva-Mikhaĭlova, A; Khristov, I

1989-01-01

The receptor organs of the vestibular apparatus of rats flown for 7 days on Cosmos-1667 were examined. Serial sections were examined by light microscopy, some utriculus sections by electron microscopy, and otolith membranes by scanning electron microscopy. The fixation method used revealed a distinct structural heterogeneity of the receptor epithelium. In the striola area of the utriculus and sacculus as well as in the central apical area of cristae there are receptor cells surrounded by enlarged cup-like nerve endings. The nerve endings occupy over 70% of the cup-receptor cell complex. The area incorporating the enlarged nerve endings differs in size from animal to animal and from left to right ear in the same animal. The flown rat that was the first to be killed after recovery showed a very well pronounced asymmetry: in the right ear enlarged cups were seen all over the epithelium while in the left ear they were located in distinct spots. Since such changes were not identified in the remaining flown and control rats, it is concluded that they were produced by space flight effects but remained reversible and disappeared after recovery. This paper describes the causes responsible of the changes and their structural and functional relevances as well as other structural modifications that should be considered during vestibular studies.

Facial nerve paralysis secondary to occult malignant neoplasms.

PubMed

Boahene, Derek O; Olsen, Kerry D; Driscoll, Colin; Lewis, Jean E; McDonald, Thomas J

2004-04-01

This study reviewed patients with unilateral facial paralysis and normal clinical and imaging findings who underwent diagnostic facial nerve exploration. Study design and setting Fifteen patients with facial paralysis and normal findings were seen in the Mayo Clinic Department of Otorhinolaryngology. Eleven patients were misdiagnosed as having Bell palsy or idiopathic paralysis. Progressive facial paralysis with sequential involvement of adjacent facial nerve branches occurred in all 15 patients. Seven patients had a history of regional skin squamous cell carcinoma, 13 patients had surgical exploration to rule out a neoplastic process, and 2 patients had negative exploration. At last follow-up, 5 patients were alive. Patients with facial paralysis and normal clinical and imaging findings should be considered for facial nerve exploration when the patient has a history of pain or regional skin cancer, involvement of other cranial nerves, and prolonged facial paralysis. Occult malignancy of the facial nerve may cause unilateral facial paralysis in patients with normal clinical and imaging findings.

Evaluation of the chemical model of vestibular lesions induced by arsanilate in rats

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

Vignaux, G.; Univ Caen, Caen, F-14000; Chabbert, C.

Several animal models of vestibular deficits that mimic the human pathology phenotype have previously been developed to correlate the degree of vestibular injury to cognate vestibular deficits in a time-dependent manner. Sodium arsanilate is one of the most commonly used substances for chemical vestibular lesioning, but it is not well described in the literature. In the present study, we used histological and functional approaches to conduct a detailed exploration of the model of vestibular lesions induced by transtympanic injection of sodium arsanilate in rats. The arsanilate-induced damage was restricted to the vestibular sensory organs without affecting the external ear, themore » oropharynx, or Scarpa's ganglion. This finding strongly supports the absence of diffusion of arsanilate into the external ear or Eustachian tubes, or through the eighth cranial nerve sheath leading to the brainstem. One of the striking observations of the present study is the complete restructuring of the sensory epithelia into a non sensory epithelial monolayer observed at 3 months after arsanilate application. This atrophy resembles the monolayer epithelia observed postmortem in the vestibular epithelia of patients with a history of lesioned vestibular deficits such as labyrinthectomy, antibiotic treatment, vestibular neuritis, or Ménière's disease. In cases of Ménière's disease, aminoglycosides, and platinum-based chemotherapy, vestibular hair cells are destroyed, regardless of the physiopathological process, as reproduced with the arsanilate model of vestibular lesion. These observations, together with those presented in this study of arsanilate vestibular toxicity, suggest that this atrophy process relies on a common mechanism of degeneration of the sensory epithelia.« less

Polyradiculopathies from schwannomatosis.

PubMed

Jia, Yuxia; Kraus, James A; Reddy, Hasini; Groff, Michael; Wong, Eric T

2011-01-01

We describe a case of schwannomatosis presenting as radicular pain and numbness in multiple radicular nerve distributions. There were multiple peripheral nerve tumors detected by magnetic resonance imaging (MRI) at the left vestibular nerve, cauda equina, right radial nerve, thoracic paraspinal nerve, and brachial plexi. Several resected tumors have features of schwannomas, including hypercellular Antoni A areas, hypocellular Antoni B areas, Verocay bodies, and hyalinized blood vessels. The specimens are also positive for immunohistochemical staining for INI1 with diffuse nuclear staining. The findings are consistent with sporadic form of schwannomatosis. This case highlights the importance of using MRI and INI1 immunohistochemistry to differentiate familial schwannomatosis, neurofibromatosis 2 (NF2)-associated schwannomatosis, and sporadic schwannomatosis.

Artificial Balance: Restoration of the Vestibulo-Ocular Reflex in Humans with a Prototype Vestibular Neuroprosthesis

PubMed Central

Perez Fornos, Angelica; Guinand, Nils; van de Berg, Raymond; Stokroos, Robert; Micera, Silvestro; Kingma, Herman; Pelizzone, Marco; Guyot, Jean-Philippe

2014-01-01

The vestibular system plays a crucial role in the multisensory control of balance. When vestibular function is lost, essential tasks such as postural control, gaze stabilization, and spatial orientation are limited and the quality of life of patients is significantly impaired. Currently, there is no effective treatment for bilateral vestibular deficits. Research efforts both in animals and humans during the last decade set a solid background to the concept of using electrical stimulation to restore vestibular function. Still, the potential clinical benefit of a vestibular neuroprosthesis has to be demonstrated to pave the way for a translation into clinical trials. An important parameter for the assessment of vestibular function is the vestibulo-ocular reflex (VOR), the primary mechanism responsible for maintaining the perception of a stable visual environment while moving. Here we show that the VOR can be artificially restored in humans using motion-controlled, amplitude modulated electrical stimulation of the ampullary branches of the vestibular nerve. Three patients received a vestibular neuroprosthesis prototype, consisting of a modified cochlear implant providing vestibular electrodes. Significantly higher VOR responses were observed when the prototype was turned ON. Furthermore, VOR responses increased significantly as the intensity of the stimulation increased, reaching on average 79% of those measured in healthy volunteers in the same experimental conditions. These results constitute a fundamental milestone and allow us to envision for the first time clinically useful rehabilitation of patients with bilateral vestibular loss. PMID:24808890

Localization of efferent neurotransmitters in the inner ear of the homozygous Bronx waltzer mutant mouse.

PubMed

Kong, W J; Scholtz, A W; Hussl, B; Kammen-Jolly, K; Schrott-Fischer, A

2002-05-01

Naturally occurring mutant mice provide an excellent model for the study of genetic malformations of the inner ear. Mice homozygous for the Bronx waltzer (bv/bv) mutation are severely hearing impaired or deaf and exhibit a 'waltzing' gait. Functional aspects of cochlear and vestibular efferents in the bv/bv mutant mouse are not well known. The present study was designed to evaluate several candidates of efferent neurotransmitters or neuromodulators including choline acetyltransferase (ChAT), gamma-aminobutyric acid (GABA), and calcitonin gene-related peptide (CGRP) in the inner ear of the bv/bv mutant mouse. Ultrastructural investigations at both light and electron microscopic level were performed. Ultrastructural morphologic evaluations of the cochlea and the vestibular end-organs were also undertaken. It is demonstrated that ChAT, GABA and CGRP immunoreactivities are present in the cochlea and in vestibular end-organs of bv/bv mutant mice. In the organ of Corti, immunoreactivity of ChAT, GABA and CGRP is confined to the inner spiral fibers, tunnel-crossing fibers, and the vesiculated nerve endings synapsing with outer hair cells. Interestingly, immunoreactivity was detectable even where inner hair cells appeared missing. Results also revealed malformations of the outer hair cells with synaptic contacts to efferent nerve endings consistently intact. In the neurosensory epithelia of the vestibular end-organs, the presence of ChAT, GABA, and CGRP immunoreactivity was localized at the vestibular efferents, with the exception of the macula of saccule. In one 8-month-old macula of utricle where the depletion of hair cells appeared highest, ChAT immunostaining was still discernible. Ultrastructural investigation demonstrated that vesiculated efferent nerve endings make synaptic contact with the outer hair cells in the organ of Corti and with type II hair cells in the vestibular end-organs. The present study provides further support that the efferent system in the bv/bv mutant inner ear is morphologically as well as functionally mature. These findings also demonstrate that if and when the onset of efferent degeneration in the bv/bv mutant inner ear occurs, it transpires subsequent to pathological conditions in the hair cells. The present findings give further indication that the efferent systems of the bv/bv mutant inner ear are independent of the afferent systems in many aspects including development, maturation as well as degeneration.

Peripheral nerves are pathologically small in cerebellar ataxia neuropathy vestibular areflexia syndrome: a controlled ultrasound study.

PubMed

Pelosi, L; Mulroy, E; Leadbetter, R; Kilfoyle, D; Chancellor, A M; Mossman, S; Wing, L; Wu, T Y; Roxburgh, R H

2018-04-01

Sensory neuronopathy is a cardinal feature of cerebellar ataxia neuropathy vestibular areflexia syndrome (CANVAS). Having observed that two patients with CANVAS had small median and ulnar nerves on ultrasound, we set out to examine this finding systematically in a cohort of patients with CANVAS, and compare them with both healthy controls and a cohort of patients with axonal neuropathy. We have previously reported preliminary findings in seven of these patients with CANVAS and seven healthy controls. We compared the ultrasound cross-sectional area of median, ulnar, sural and tibial nerves of 14 patients with CANVAS with 14 healthy controls and 14 age- and gender-matched patients with acquired primarily axonal neuropathy. We also compared the individual nerve cross-sectional areas of patients with CANVAS and neuropathy with the reference values of our laboratory control population. The nerve cross-sectional area of patients with CANVAS was smaller than that of both the healthy controls and the neuropathy controls, with highly significant differences at most sites (P < 0.001). Conversely, the nerve cross-sectional areas in the upper limb were larger in neuropathy controls than healthy controls (P < 0.05). On individual analysis, the ultrasound abnormality was sufficiently characteristic to be detected in all but one patient with CANVAS. Small nerves in CANVAS probably reflect nerve thinning from loss of axons due to ganglion cell loss. This is distinct from the ultrasound findings in axonal neuropathy, in which nerve size was either normal or enlarged. Our findings indicate a diagnostic role for ultrasound in CANVAS sensory neuronopathy and in differentiating neuronopathy from neuropathy. © 2018 EAN.

The diagnostic value of earlier and later components of Vestibular Evoked Myogenic Potentials (VEMP) in multiple sclerosis.

PubMed

Eleftheriadou, A; Deftereos, S N; Zarikas, V; Panagopoulos, G; Sfetsos, S; Karageorgiou, C L; Ferekidou, E; Kandiloros, D; Korres, S

2009-01-01

To evaluate the ability of VEMP to disclose spatial dissemination of Multiple Sclerosis. Forty-six MS patients with auditory and/or vestibular symptoms were studied. Patients were divided in two groups. Group 1 included 24 patients with brainstem MRI findings, and Group 2 included 22 patients without MRI findings. VEMP and BAEP have been recorded and assessed. Abnormal p13n23 wave was observed in 50%, while unilateral absence or bilateral delay of the n34p44 in 43% of the patients. The overall diagnostic value considering abnormal cases suggested by both first and second VEMP waves was increased to 71%. Statistically significant differences revealed between patients and controls for p13 latency (p=0.018). The p13n23 was abnormal in 7 patients, although MRI scanning did not reveal brainstem lesions. In 9 out of 18 MS patients suffering from unilateral hearing loss, n34p44 was present in the unaffected ears and absent in the affected side, although p13n23 was normal. Abnormal VEMP imply the presence of lesions undetected by MRI neuroimaging, which verifies the diagnostic value of the method. Unilateral absence of n34p44 complex was related with sensorineural hearing loss, supporting the hypothesis that n34p44 is of cochlear origin.

Gamma Knife radiosurgery for vestibular schwannoma: case report and review of the literature

PubMed Central

2009-01-01

Vestibular schwannomas, also called acoustic neuromas, are benign tumors of the vestibulocochlear nerve. Patients with these tumours almost always present with signs of hearing loss, and many also experience tinnitus, vertigo, and equilibrium problems. Following diagnosis with contrast enhanced MRI, patients may choose to observe the tumour with subsequent scans or seek active treatment in the form of microsurgery, radiosurgery, or radiotherapy. Unfortunately, definitive guidelines for treating vestibular schwannomas are lacking, because of insufficient evidence comparing the outcomes of therapeutic modalities. We present a contemporary case report, describing the finding of a vestibular schwannoma in a patient who presented with dizziness and a "clicking" sensation in the ear, but no hearing deficit. Audible clicking is a symptom that, to our knowledge, has not been associated with vestibular schwannoma in the literature. We discuss the diagnosis and patient's decision-making process, which led to treatment with Gamma Knife radiosurgery. Treatment resulted in an excellent radiographic response and complete hearing preservation. This case highlights an atypical presentation of vestibular schwannoma, associated with audible "clicks" and normal hearing. We also provide a concise review of the available literature on modern vestibular schwannoma treatment, which may be useful in guiding treatment decisions. PMID:20021676

Gamma Knife radiosurgery for vestibular schwannoma: case report and review of the literature.

PubMed

Arthurs, Benjamin J; Lamoreaux, Wayne T; Giddings, Neil A; Fairbanks, Robert K; Mackay, Alexander R; Demakas, John J; Cooke, Barton S; Lee, Christopher M

2009-12-18

Vestibular schwannomas, also called acoustic neuromas, are benign tumors of the vestibulocochlear nerve. Patients with these tumours almost always present with signs of hearing loss, and many also experience tinnitus, vertigo, and equilibrium problems. Following diagnosis with contrast enhanced MRI, patients may choose to observe the tumour with subsequent scans or seek active treatment in the form of microsurgery, radiosurgery, or radiotherapy. Unfortunately, definitive guidelines for treating vestibular schwannomas are lacking, because of insufficient evidence comparing the outcomes of therapeutic modalities.We present a contemporary case report, describing the finding of a vestibular schwannoma in a patient who presented with dizziness and a "clicking" sensation in the ear, but no hearing deficit. Audible clicking is a symptom that, to our knowledge, has not been associated with vestibular schwannoma in the literature. We discuss the diagnosis and patient's decision-making process, which led to treatment with Gamma Knife radiosurgery. Treatment resulted in an excellent radiographic response and complete hearing preservation. This case highlights an atypical presentation of vestibular schwannoma, associated with audible "clicks" and normal hearing. We also provide a concise review of the available literature on modern vestibular schwannoma treatment, which may be useful in guiding treatment decisions.

Isolation and culture of adult mouse vestibular nucleus neurons

PubMed

Him, Aydın; Altuntaş, Serap; Öztürk, Gürkan; Erdoğan, Ender; Cengiz, Nureddin

2017-12-19

Background/aim: Isolated cell cultures are widely used to study neuronal properties due to their advantages. Although embryonic animals are preferred for culturing, their morphological or electrophysiological properties may not reflect adult neurons, which may be important in neurodegenerative diseases. This paper aims to develop a method for preparing isolated cell cultures of medial vestibular nucleus (MVN) from adult mice and describe its morphological and electrophysiological properties.Materials and methods: Vestibular nucleus neurons were mechanically and enzymatically isolated and cultured using a defined medium with known growth factors. Cell survival was measured with propidium iodide, and electrophysiological properties were investigated with current-clamp recording.Results: Vestibular neurons grew neurites in cultures, gaining adult-like morphological properties, and stayed viable for 3 days in culture. Adding bovine calf serum, nerve growth factor, or insulin-like growth factor into the culture medium enhanced neuronal viability. Current-clamp recording of the cultured neurons revealed tonic and phasic-type neurons with similar input resistance, resting membrane potential, action potential amplitude, and duration. Conclusion: Vestibular neurons from adult mice can be cultured, and regenerate axons in a medium containing appropriate growth factors. Culturing adult vestibular neurons provides a new method to study age-related pathologies of the vestibular system.

Progress Toward Development of a Multichannel Vestibular Prosthesis for Treatment of Bilateral Vestibular Deficiency

PubMed Central

FRIDMAN, GENE Y.; DELLA SANTINA, CHARLES C.

2014-01-01

This article reviews vestibular pathology and the requirements and progress made in the design and construction of a vestibular prosthesis. Bilateral loss of vestibular sensation is disabling. When vestibular hair cells are injured by ototoxic medications or other insults to the labyrinth, the resulting loss of sensory input disrupts vestibulo-ocular reflexes (VORs) and vestibulo-spinal reflexes that normally stabilize the eyes and body. Affected individuals suffer poor vision during head movement, postural instability, chronic disequilibrium, and cognitive distraction. Although most individuals with residual sensation compensate for their loss over time, others fail to do so and have no adequate treatment options. A vestibular prosthesis analogous to cochlear implants but designed to modulate vestibular nerve activity during head movement should improve quality of life for these chronically dizzy individuals. We describe the impact of bilateral loss of vestibular sensation, animal studies supporting feasibility of prosthetic vestibular stimulation, the current status of multichannel vestibular sensory replacement prosthesis development, and challenges to successfully realizing this approach in clinical practice. In bilaterally vestibular-deficient rodents and rhesus monkeys, the Johns Hopkins multichannel vestibular prosthesis (MVP) partially restores the three-dimensional (3D) VOR for head rotations about any axis. Attempts at prosthetic vestibular stimulation of humans have not yet included the 3D eye movement assays necessary to accurately evaluate VOR alignment, but these initial forays have revealed responses that are otherwise comparable to observations in animals. Current efforts now focus on refining electrode design and surgical technique to enhance stimulus selectivity and preserve cochlear function, optimizing stimulus protocols to improve dynamic range and reduce excitation–inhibition asymmetry, and adapting laboratory MVP prototypes into devices appropriate for use in clinical trials. PMID:23044664

Genetics Home Reference: neurofibromatosis type 2

MedlinePlus

... neurofibromatosis type 2 are called vestibular schwannomas or acoustic neuromas. These growths develop along the nerve that ... Boston Children's Hospital GeneReview: Neurofibromatosis 2 MedlinePlus ... Encyclopedia: Neurofibromatosis 2 Neurofibromatosis Clinic, Massachusetts ...

Peripheral innervation patterns of vestibular nerve afferents in the bullfrog utriculus

NASA Technical Reports Server (NTRS)

Baird, Richard A.; Schuff, N. R.

1994-01-01

Vestibular nerve afferents innervating the bullfrog utriculus differ in their response dynamics and sensitivity to natural stimulation. They also supply hair cells that differ markedly in hair bundle morphology. To examine the peripheral innervation patterns of individual utricular afferents more closely, afferent fibers were labeled by the extracellular injection of horseradish peroxidase (HRP) into the vestibular nerve after sectioning the vestibular nerve medial to Scarpa's ganglion to allow the degeneration of sympathetic and efferent fibers. The peripheral arborizations of individual afferents were then correlated with the diameters of their parent axons, the regions of the macula they innervate, and the number and type of hair cells they supply. The utriculus is divided by the striola, a narrow zone of distinctive morphology, into media and lateral parts. Utiricular afferents were classified as striolar or extrastriolar according to the epithelial entrance of their parent axons and the location of their terminal fields. In general, striolar afferents had thicker parent axons, fewer subepithelial bifurcations, larger terminal fields, and more synaptic endings than afferents in extrstriolar regions. Afferents in a juxtastriolar zone, immediately adjacent to the medial striola, had innervation patterns transitional between those in the striola and more peripheral parts of the medial extrastriola. moast afferents innervated only a single macular zone. The terminal fields of striolar afferents, with the notable exception of a few afferents with thin parent axons, were generally confined to one side of the striola. Hair cells in the bullfrog utriculus have perviously been classified into four types based on hair bundle morphology. Afferents in the extrastriolar and juxtastriolar zones largely or exclusively innervated Type B hair cells, the predominant hair cell type in the utricular macula. Striolar afferents supplied a mixture of four hair cell types, but largely contacted Type B and Type C hair cells, particularly on the outer rows of the medial striola. Afferents supplying more central striolar regions innervated fewer Type B and larger numbers of Type E and Type F hair cells. Striolar afferents with thin parent axons largely supplied Type E hair cells with bulbed kniocilia in the innermost striolar rows.

Angiofibroma Originating outside the Nasopharynx: A Management Dilemma

PubMed Central

Mahmood, Ashraf Nabeel; Saey, Hamad Al; Ashkanani, Sarah; Ganesan, Shanmugam

2016-01-01

Background. Angiofibroma is a benign tumor, consisting of fibrous tissue with varying degrees of vascularity, characterized by proliferation of stellate and spindle cells around the blood vessels. It most commonly arises from the nasopharynx, although it may rarely arise in extranasopharyngeal sites. Case Report. A 46-year-old male presented with left side nasal obstruction and epistaxis for one month. Clinical nasal examination revealed left sided polypoidal mass arising from the vestibular region of the lateral nasal wall. Results. CT scan and MRI showed highly vascular soft tissue mass occupying the anterior part of the left nostril. Preoperative selective embolization followed by transnasal excision was performed. Histopathological examination confirmed the diagnoses of nasal vestibular angiofibroma. Conclusion. Extranasopharyngeal angiofibroma is a very rare pathology. It should be kept in mind as a differential diagnosis with any unilateral nasal vestibular mass causing nasal obstruction and epistaxis. A biopsy without further investigation can cause life threatening bleeding in the patient. PMID:27957369

Primary unilateral cleft lip repair.

PubMed

Adenwalla, H S; Narayanan, P V

2009-10-01

The unilateral cleft lip is a complex deformity. Surgical correction has evolved from a straight repair through triangular and quadrilateral repairs to the Rotation Advancement Technique of Millard. The latter is the technique followed at our centre for all unilateral cleft lip patients. We operate on these at five to six months of age, do not use pre-surgical orthodontics, and follow a protocol to produce a notch-free vermillion. This is easy to follow even for trainees. We also perform closed alar dissection and extensive primary septoplasty in all these patients. This has improved the overall result and has no long-term deleterious effect on the growth of the nose or of the maxilla. Other refinements have been used for prevention of a high-riding nostril, and correction of the vestibular web.

Primary unilateral cleft lip repair

PubMed Central

Adenwalla, H. S.; Narayanan, P. V.

2009-01-01

The unilateral cleft lip is a complex deformity. Surgical correction has evolved from a straight repair through triangular and quadrilateral repairs to the Rotation Advancement Technique of Millard. The latter is the technique followed at our centre for all unilateral cleft lip patients. We operate on these at five to six months of age, do not use pre-surgical orthodontics, and follow a protocol to produce a notch-free vermillion. This is easy to follow even for trainees. We also perform closed alar dissection and extensive primary septoplasty in all these patients. This has improved the overall result and has no long-term deleterious effect on the growth of the nose or of the maxilla. Other refinements have been used for prevention of a high-riding nostril, and correction of the vestibular web. PMID:19884683

Input/output properties of the lateral vestibular nucleus

NASA Technical Reports Server (NTRS)

Boyle, R.; Bush, G.; Ehsanian, R.

2004-01-01

This article is a review of work in three species, squirrel monkey, cat, and rat studying the inputs and outputs from the lateral vestibular nucleus (LVN). Different electrophysiological shock paradigms were used to determine the synaptic inputs derived from thick to thin diameter vestibular nerve afferents. Angular and linear mechanical stimulations were used to activate and study the combined and individual contribution of inner ear organs and neck afferents. The spatio-temporal properties of LVN neurons in the decerebrated rat were studied in response to dynamic acceleration inputs using sinusoidal linear translation in the horizontal head plane. Outputs were evaluated using antidromic identification techniques and identified LVN neurons were intracellularly injected with biocytin and their morphology studied.

Dynamic expression of transcription factor Brn3b during mouse cranial nerve development

PubMed Central

Sajgo, Szilard; Ali, Seid; Popescu, Octavian; Badea, Tudor Constantin

2015-01-01

During development transcription factor combinatorial codes define a large variety of morphologically and physiologically distinct neurons. Such a combinatorial code has been proposed for the differentiation of projection neurons of the somatic and visceral components of cranial nerves. It is possible that individual neuronal cell types are not specified by unique transcription factors, but rather emerge through the intersection of their expression domains. Brn3a, Brn3b and Brn3c, in combination with each other and/or transcription factors of other families, can define subgroups of Retinal Ganglion Cells (RGC), Spiral and Vestibular Ganglia, inner ear and vestibular hair cell neurons in the vestibuloacoustic system, and groups of somatosensory neurons in the Dorsal Root Ganglia (DRG). In the present study we investigated the expression and potential role of the Brn3b transcription factor in cranial nerves and associated nuclei of the brainstem. We report the dynamic expression of Brn3b in the somatosensory component of cranial nerves II, V, VII and VIII and visceromotor nuclei of nerves VII, IX, X, as well as other brainstem nuclei during different stages of development into adult stage. We find that genetically identified Brn3bKO RGC axons show correct but delayed pathfinding during the early stages of embryonic development. However loss of Brn3b does not affect the anatomy of the other cranial nerves normally expressing this transcription factor. PMID:26356988

BDNF is required for taste axon regeneration following unilateral chorda tympani nerve section.

PubMed

Meng, Lingbin; Huang, Tao; Sun, Chengsan; Hill, David L; Krimm, Robin

2017-07-01

Taste nerves readily regenerate to reinnervate denervated taste buds; however, factors required for regeneration have not yet been identified. When the chorda tympani nerve is sectioned, expression of brain-derived neurotrophic factor (BDNF) remains high in the geniculate ganglion and lingual epithelium, despite the loss of taste buds. These observations suggest that BDNF is present in the taste system after nerve section and may support taste nerve regeneration. To test this hypothesis, we inducibly deleted Bdnf during adulthood in mice. Shortly after Bdnf gene recombination, the chorda tympani nerve was unilaterally sectioned causing a loss of both taste buds and neurons, irrespective of BDNF levels. Eight weeks after nerve section, however, regeneration was differentially affected by Bdnf deletion. In control mice, there was regeneration of the chorda tympani nerve and taste buds reappeared with innervation. In contrast, few taste buds were reinnervated in mice lacking normal Bdnf expression such that taste bud number remained low. In all genotypes, taste buds that were reinnervated were normal-sized, but non-innervated taste buds remained small and atrophic. On the side of the tongue contralateral to the nerve section, taste buds for some genotypes became larger and all taste buds remained innervated. Our findings suggest that BDNF is required for nerve regeneration following gustatory nerve section. Copyright © 2017 Elsevier Inc. All rights reserved.

Polyradiculopathies from Schwannomatosis

PubMed Central

Jia, Yuxia; Kraus, James A.; Reddy, Hasini; Groff, Michael; Wong, Eric T

2011-01-01

We describe a case of schwannomatosis presenting as radicular pain and numbness in multiple radicular nerve distributions. There were multiple peripheral nerve tumors detected by magnetic resonance imaging (MRI) at the left vestibular nerve, cauda equina, right radial nerve, thoracic paraspinal nerve, and brachial plexi. Several resected tumors have features of schwannomas, including hypercellular Antoni A areas, hypocellular Antoni B areas, Verocay bodies, and hyalinized blood vessels. The specimens are also positive for immunohistochemical staining for INI1 with diffuse nuclear staining. The findings are consistent with sporadic form of schwannomatosis. This case highlights the importance of using MRI and INI1 immunohistochemistry to differentiate familial schwannomatosis, neurofibromatosis 2 (NF2)-associated schwannomatosis, and sporadic schwannomatosis. PMID:21643503

Facial neuropathy with imaging enhancement of the facial nerve: a case report

PubMed Central

Mumtaz, Sehreen; Jensen, Matthew B

2014-01-01

A young women developed unilateral facial neuropathy 2 weeks after a motor vehicle collision involving fractures of the skull and mandible. MRI showed contrast enhancement of the facial nerve. We review the literature describing facial neuropathy after trauma and facial nerve enhancement patterns with different causes of facial neuropathy. PMID:25574155

Herpes zoster: A clinicocytopathological insight.

PubMed

Shah, Snehal; Singaraju, Sasidhar; Einstein, A; Sharma, Ashish

2016-01-01

Herpes zoster or shingles is reactivation of the varicella zoster virus that had entered the cutaneous nerve endings during an earlier episode of chicken pox traveled to the dorsal root ganglia and remained in a latent form. This condition is characterized by occurrence of multiple, painful, unilateral vesicles and ulceration which shows a typical single dermatome involvement. In this case report, we present a patient with herpes zoster involving the mandibular division of the trigeminal nerve, with unilateral vesicles over the right side of lower third of face along the trigeminal nerve tract, with intraoral involvement of buccal mucosa, labial mucosa and the tongue of the same side. Cytopathology revealed classic features of herpes infection including inclusion bodies, perinuclear halo and multinucleated cells.

Experimental studies of gastric dysfunction in motion sickness: The effect of gastric and vestibular stimulation on the vagal and splanchnic gastric efferents

NASA Technical Reports Server (NTRS)

Niijima, A.; Jiang, Z. Y.; Daunton, Nancy G.; Fox, Robert A.

1991-01-01

The experiments were conducted in anaesthetized rats. In the first part of the experiments, the effect of CuSO4 on the afferent activity in the gastric branch of the vagus nerve was investigated. Gastric perfusion of CuSO4 solution (0.04 percent and 0.08 percent) provoked an increase in afferent activity. In the second part of the experiments, the reflex effects of gastric perfusion of CuSO4 solution, repetitive stimulation of the gastric vagus nerve, and caloric stimulation of the right vestibular apparatus (5-18 C water) on gastric autonomic outflow were investigated. The results of these experiments showed that these three different types of stimulation caused an inhibition in efferent activity of the gastric vagus nerve and a slight activation of the splanchnic gastric efferents. The summation of the effect of each stimulation was also observed. These results, therefore, provide evidence for a possible integrative inhibitory function of the vagal gastric center as well as an excitatory function of gastric sympathetic motoneurons in relation to motion sickness.

Single institution experience treating 104 vestibular schwannomas with fractionated stereotactic radiation therapy or stereotactic radiosurgery.

PubMed

Anderson, Bethany M; Khuntia, Deepak; Bentzen, Søren M; Geye, Heather M; Hayes, Lori L; Kuo, John S; Baskaya, Mustafa K; Badie, Behnam; Basavatia, Amar; Pyle, G Mark; Tomé, Wolfgang A; Mehta, Minesh P

2014-01-01

The pupose of this study is to assess the long-term outcome and toxicity of fractionated stereotactic radiation therapy (FSRT) and stereotactic radiosurgery (SRS) for 100 vestibular schwannomas treated at a single institution. From 1993 to 2007, 104 patients underwent were treated with radiation therapy for vestibular schwannoma. Forty-eight patients received SRS, with a median prescription dose of 12.5 Gy for SRS (range 9.7-16 Gy). For FSRT, two different fraction schedules were employed: a conventional schedule (ConFSRT) of 1.8 Gy per fraction (Gy/F) for 25 or 28 fractions to a total dose of 45 or 50.4 Gy (n = 19); and a once weekly hypofractionated course (HypoFSRT) consisting of 4 Gy/F for 5 fractions to a total dose of 20 Gy (n = 37). Patients treated with FSRT had better baseline hearing, facial, and trigeminal nerve function, and were more likely to have a diagnosis of NF2. The 5-year progression free rate (PFR) was 97.0 after SRS, 90.5% after HypoFSRT, and 100.0% after ConFSRT (p = NS). Univariate analysis demonstrated that NF2 and larger tumor size (greater than the median) correlated with poorer local control, but prior surgical resection did not. Serviceable hearing was preserved in 60.0% of SRS patients, 63.2% of HypoFSRT patients, and 44.4% of ConFSRT patients (p = 0.6). Similarly, there were no significant differences in 5-year rates of trigeminal toxicity facial nerve toxicity, vestibular dysfunction, or tinnitus. Equivalent 5-year PFR and toxicity rates are shown for patients with vestibular schwanoma selected for SRS, HypoFSRT, and ConFSRT after multidisciplinary evaluation. Factors correlating with tumor progression included NF2 and larger tumor size.

Signal processing related to the vestibulo-ocular reflex during combined angular rotation and linear translation of the head

NASA Technical Reports Server (NTRS)

McCrea, R. A.; Chen-Huang, C.; Peterson, B. W. (Principal Investigator)

1999-01-01

The contributions of vestibular nerve afferents and central vestibular pathways to the angular (AVOR) and linear (LVOR) vestibulo-ocular reflex were studied in squirrel monkeys during fixation of near and far targets. Irregular vestibular afferents did not appear to be necessary for the LVOR, since when they were selectively silenced with galvanic currents the LVOR was essentially unaffected during both far- and near-target viewing. The linear translation signals generated by secondary AVOR neurons in the vestibular nuclei were, on average, in phase with head velocity, inversely related to viewing distance, and were nearly as strong as AVOR-related signals. We suggest that spatial-temporal transformation of linear head translation signals to angular eye velocity commands is accomplished primarily by the addition of viewing distance multiplied, centrally integrated, otolith regular afferent signals to angular VOR pathways.

Cervical Vestibular-Evoked Myogenic Potentials: Norms and Protocols

PubMed Central

Isaradisaikul, Suwicha; Navacharoen, Niramon; Hanprasertpong, Charuk; Kangsanarak, Jaran

2012-01-01

Vestibular-evoked myogenic potential (VEMP) testing is a vestibular function test used for evaluating saccular and inferior vestibular nerve function. Parameters of VEMP testing include VEMP threshold, latencies of p1 and n1, and p1-n1 interamplitude. Less commonly used parameters were p1-n1 interlatency, interaural difference of p1 and n1 latency, and interaural amplitude difference (IAD) ratio. This paper recommends using air-conducted 500 Hz tone burst auditory stimulation presented monoaurally via an inserted ear phone while the subject is turning his head to the contralateral side in the sitting position and recording the responses from the ipsilateral sternocleidomastoid muscle. Normative values of VEMP responses in 50 normal audiovestibular volunteers were presented. VEMP testing protocols and normative values in other literature were reviewed and compared. The study is beneficial to clinicians as a reference guide to set up VEMP testing and interpretation of the VEMP responses. PMID:22577386

The primary vestibular projection to the cerebellar cortex in the pigeon (Columba livia)

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

Schwarz, I.E.; Schwarz, D.W.

1983-06-01

The cerebellar cortex of the pigeon receiving direct vestibular afferents was delineated by anterograde transport of (/sup 3/H)-amino acids injected into the vestibular nerve. Labelled mossy fiber rosettes in the granular layer were concentrated in lobule X (nodulus) and to a lesser extent, in the ventral portion of lobule IXd (uvula and paraflocculus). A few solitary labelled rosettes were also found in more dorsal portions of lobule IX, as well as in the anterior lobe between lobule II and IV. The lingula remained unlabelled. Discrete injections of (/sup 3/H)-leucine into the cristae of each of the three semicircular canals ormore » the utricular macula yielded a similar distribution of fewer labelled rosettes. A few primary mossy fiber terminals labelled after cochlear injections are attributed to afferents from the lagenar macula. Since effective diffusion of label from the injection site was excluded by controls, it is concluded that projection of individual canal and macula nerves to the vestibulocerebellar cortex is not topographically separated. It is proposed that this extensive convergence of various afferents is required by the cerebellum to compute precise and directionally specific control signals during head rotation in all conceivable planes.« less

Delayed presentation of traumatic facial nerve (CN VII) paralysis.

PubMed

Napoli, Anthony M; Panagos, Peter

2005-11-01

Facial nerve paralysis (Cranial Nerve VII, CN VII) can be a disfiguring disorder with profound impact upon the patient. The etiology of facial nerve paralysis may be congenital, iatrogenic, or result from neoplasm, infection, trauma, or toxic exposure. In the emergency department, the most common cause of unilateral facial paralysis is Bell's palsy, also known as idiopathic facial paralysis (IFP). We report a case of delayed presentation of unilateral facial nerve paralysis 3 days after sustaining a traumatic head injury. Re-evaluation and imaging of this patient revealed a full facial paralysis and temporal bone fracture extending into the facial canal. Because cranial nerve injuries occur in approximately 5-10% of head-injured patients, a good history and physical examination is important to differentiate IFP from another etiology. Newer generation high-resolution computed tomography (CT) scans are commonly demonstrating these fractures. An understanding of this complication, appropriate patient follow-up, and early involvement of the Otolaryngologist is important in management of these patients. The mechanism as well as the timing of facial nerve paralysis will determine the proper evaluation, consultation, and management for the patient. Patients with total or immediate paralysis as well as those with poorly prognostic audiogram results are good candidates for surgical repair.

Vestibular Evoked Myogenic Potential Produced by Bone-Conducted Stimuli: A Study on its Basics and Clinical Applications in Patients with Conductive and Sensorineural Hearing Loss and a Group with Vestibular Schawannoma.

PubMed

Mahdi, Parvane; Amali, Amin; Pourbakht, Akram; Karimi Yazdi, Alireza; Bassam, Ali

2013-06-01

Vestibular evoked myogenic potential (VEMP) has recently been broadly studied in vestibular disorders. As it is evoked by loud sound stimulation, even mild conductive hearing loss may affect VEMP results. Bone-conducted (BC) stimulus is an alternative stimulation for evoking this response. This study aims to assess the characteristics of BC-VEMP in different groups of patients. We performed a cross sectional analysis on 20 healthy volunteers with normal pure-tone audiometry as a control group; and on a group of patients consisted of 20 participants with conductive hearing loss, five with bilateral sensorineural hearing loss and four with vestibular schawannoma. AC and BC-VEMP were performed in all participants. In control group the VEMP responses to both kinds of stimuli had an acceptable morphology and consisted of p13 and n23 waves. Latency value of these main components in each type of stimulus was not significantly different (P>0.05). However, the mean amplitude was larger in BC modality than AC stimulation (P=0.025). In the group with conductive hearing loss, the VEMP response was absent in fifteen (46.87%) of the 32 ears using the AC method, whereas all (100%) displayed positive elicitability of VEMP by BC method. Normal VEMP responses in both stimuli were evoked in all patients with sensorineural hearing loss. In patients with unilateral vestibular schwannomas (VS), 2 (50.00%) had neither AC-VEMP nor BC-VEMP. Auditory stimuli delivered by bone conduction can evoke VEMP response. These responses are of vestibular origin and can be used in vestibular evaluation of patients with conductive hearing loss.

Vestibular Evoked Myogenic Potential Produced by Bone-Conducted Stimuli: A Study on its Basics and Clinical Applications in Patients with Conductive and Sensorineural Hearing Loss and a Group with Vestibular Schawannoma

PubMed Central

Mahdi, Parvane; Amali, Amin; Pourbakht, Akram; Karimi Yazdi, Alireza; Bassam, Ali

2013-01-01

Introduction: Vestibular evoked myogenic potential (VEMP) has recently been broadly studied in vestibular disorders. As it is evoked by loud sound stimulation, even mild conductive hearing loss may affect VEMP results. Bone-conducted (BC) stimulus is an alternative stimulation for evoking this response. This study aims to assess the characteristics of BC-VEMP in different groups of patients. Materials and Methods: We performed a cross sectional analysis on 20 healthy volunteers with normal pure-tone audiometry as a control group; and on a group of patients consisted of 20 participants with conductive hearing loss, five with bilateral sensorineural hearing loss and four with vestibular schawannoma. AC and BC-VEMP were performed in all participants. Results: In control group the VEMP responses to both kinds of stimuli had an acceptable morphology and consisted of p13 and n23 waves. Latency value of these main components in each type of stimulus was not significantly different (P>0.05). However, the mean amplitude was larger in BC modality than AC stimulation (P=0.025). In the group with conductive hearing loss, the VEMP response was absent in fifteen (46.87%) of the 32 ears using the AC method, whereas all (100%) displayed positive elicitability of VEMP by BC method. Normal VEMP responses in both stimuli were evoked in all patients with sensorineural hearing loss. In patients with unilateral vestibular schwannomas (VS), 2 (50.00%) had neither AC-VEMP nor BC-VEMP. Conclusion: Auditory stimuli delivered by bone conduction can evoke VEMP response. These responses are of vestibular origin and can be used in vestibular evaluation of patients with conductive hearing loss. PMID:24303434

The Dizziness Handicap Inventory does not correlate with vestibular function tests: a prospective study.

PubMed

Yip, Chun Wai; Strupp, Michael

2018-05-01

The Dizziness Handicap Inventory (DHI) is believed to quantitate the handicap related to the presence or severity of underlying vestibular dysfunction. However, patients with chronic vestibular diseases may manifest various degrees of behavioural and physiological adaptation resulting in variances of the DHI. Our primary study objective is to evaluate the correlation between the DHI and measurable vestibular parameters. Secondarily, we compared DHI among different vestibular disorders (central, peripheral and functional), and different types of anatomic deficits (semicircular canal vs otolithic). We also correlated the DHI and posturography. We prospectively evaluated 799 patients with precise vestibular diagnoses using video head impulse testing (vHIT), caloric irrigation, and cervical/ocular vestibular-evoked myogenic potentials (c/oVEMP). Posturography was done for 84 patients. All participants completed the DHI. No significant correlation was found between DHI and (1) vestibulo-ocular reflex parameters: unilateral weakness r = - 0.018, total calorics r = 0.055, vHIT right r = 0.007, vHIT left r = - 0.091, vHIT asymmetry r = 0.013; (2) otolith parameters: cVEMP amplitude right r = - 0.034, amplitude left r = - 0.004, asymmetry r = 0.016; oVEMP amplitude right r = 0.044, amplitude left r = - 0.007, asymmetry r = - 0.008. Patients with central vestibular disorders had higher DHI than those with peripheral (z = - 4.743, p = 0.001) or functional disorders (z = - 2.902, p = 0.004). DHI of patients with deficits of canal or otolith function did not differ significantly from those with no deficits (z = 2.153, p = 0.541). There was no significant correlation between DHI and postural sway on posturography. Therefore, the DHI does not correlate with vestibular tests, and neither reflects the presence nor severity of peripheral vestibular deficits.

Role of otolith endorgans in the genesis of vestibular-visual conflict sickness (pitch) in the squirrel monkey (First report)

NASA Technical Reports Server (NTRS)

Igarashi, Makoto; Himi, Tetsuo; Kulecz, Walter B.; Kobayashi, Kazutoyo

1987-01-01

The effects of ablation of the macula utriculi and macula sacculi on vestibular-visual conflict emesis in squirrel monkeys are investigated. An optokinetic drum and a turntable were used for the direction conflict experiment. A significant difference between the preoperative condition and postunilateral and postbilateral utriculo-sacculectomy conditions is observed. It is detected that after unilateral sacculectomy the conflict sickness decreases and no emesis occurs; however, 4.5 months after sacculectomy, the animals regain their conflict sickness. The data reveal that macular afferents are important in the genesis of sensory conflict emesis and two submodalities may be needed to cause conflict sickness onset.

The results of vestibular evoked myogenic potentials, with consideration of age-related changes, in vestibular neuritis, benign paroxysmal positional vertigo, and Meniere's disease.

PubMed

Hong, Seok Min; Yeo, Seung Geun; Kim, Sung Wan; Cha, Chang Il

2008-08-01

We interpreted VEMP findings in patients with the three major peripheral vertigo diseases, taking age-related changes into consideration. We found different abnormal VEMP rates among the three diseases, as well as differences in the proportion of parameters that were abnormal, according to the type of disease. Vestibular neuritis, benign paroxysmal positional vertigo (BPPV), and Meniere's disease, common diseases that cause peripheral vertigo, often affect the saccule or inferior vestibular nerve, which are pathways of vestibular evoked myogenic potential (VEMP). Also, aging could have a primary effect on diminished VEMP responses. Our study investigated VEMP the findings in patients with the diseases in relation to their age. A total of 134 patients with vestibular neuritis, 62 with BPPV, and 29 with Meniere's disease were enrolled in this study. The VEMP findings in patients within the three disease groups were interpreted using our own normative ranges according to age. Abnormal VEMP rates in the vestibular neuritis, BPPV, and Meniere's disease groups were 36.6%, 25.8%, and 69%, respectively. The proportion of prolonged p13 latency in BPPV patients with abnormal VEMP responses was relatively high compared with the other two diseases. VEMP asymmetry in the patients with Meniere's disease was relatively high.

[Functional anatomy of the cochlear nerve and the central auditory system].

PubMed

Simon, E; Perrot, X; Mertens, P

2009-04-01

The auditory pathways are a system of afferent fibers (through the cochlear nerve) and efferent fibers (through the vestibular nerve), which are not limited to a simple information transmitting system but create a veritable integration of the sound stimulus at the different levels, by analyzing its three fundamental elements: frequency (pitch), intensity, and spatial localization of the sound source. From the cochlea to the primary auditory cortex, the auditory fibers are organized anatomically in relation to the characteristic frequency of the sound signal that they transmit (tonotopy). Coding the intensity of the sound signal is based on temporal recruitment (the number of action potentials) and spatial recruitment (the number of inner hair cells recruited near the cell of the frequency that is characteristic of the stimulus). Because of binaural hearing, commissural pathways at each level of the auditory system and integration of the phase shift and the difference in intensity between signals coming from both ears, spatial localization of the sound source is possible. Finally, through the efferent fibers in the vestibular nerve, higher centers exercise control over the activity of the cochlea and adjust the peripheral hearing organ to external sound conditions, thus protecting the auditory system or increasing sensitivity by the attention given to the signal.

The vestibulosympathetic reflex in humans: neural interactions between cardiovascular reflexes

NASA Technical Reports Server (NTRS)

Ray, Chester A.; Monahan, Kevin D.

2002-01-01

1. Over the past 5 years, there has been emerging evidence that the vestibular system regulates sympathetic nerve activity in humans. We have studied this issue in humans by using head-down rotation (HDR) in the prone position. 2. These studies have clearly demonstrated increases in muscle sympathetic nerve activity (MSNA) and calf vascular resistance during HDR. These responses are mediated by engagement of the otolith organs and not the semicircular canals. 3. However, differential activation of sympathetic nerve activity has been observed during HDR. Unlike MSNA, skin sympathetic nerve activity does not increase with HDR. 4. Examination of the vestibulosympathetic reflex with other cardiovascular reflexes (i.e. barorereflexes and skeletal muscle reflexes) has shown an additive interaction for MSNA. 5. The additive interaction between the baroreflexes and vestibulosympathetic reflex suggests that the vestibular system may assist in defending against orthostatic challenges in humans by elevating MSNA beyond that of the baroreflexes. 6. In addition, the further increase in MSNA via otolith stimulation during isometric handgrip, when arterial pressure is elevated markedly, indicates that the vestibulosympathetic reflex is a powerful activator of MSNA and may contribute to blood pressure and flow regulation during dynamic exercise. 7. Future studies will help evaluate the importance of the vestibulosympathetic reflex in clinical conditions associated with orthostatic hypotension.

Vestibular influences on autonomic cardiovascular control in humans

NASA Technical Reports Server (NTRS)

Biaggioni, I.; Costa, F.; Kaufmann, H.; Robertson, D. (Principal Investigator)

1998-01-01

There is substantial evidence that anatomical connections exist between vestibular and autonomic nuclei. Animal studies have shown functional interactions between the vestibular and autonomic systems. The nature of these interactions, however, is complex and has not been fully defined. Vestibular stimulation has been consistently found to reduce blood pressure in animals. Given the potential interaction between vestibular and autonomic pathways this finding could be explained by a reduction in sympathetic activity. However, rather than sympathetic inhibition, vestibular stimulation has consistently been shown to increase sympathetic outflow in cardiac and splanchnic vascular beds in most experimental models. Several clinical observations suggest that a link between vestibular and autonomic systems may also exist in humans. However, direct evidence for vestibular/autonomic interactions in humans is sparse. Motion sickness has been found to induce forearm vasodilation and reduce baroreflex gain, and head down neck flexion induces transient forearm and calf vasoconstriction. On the other hand, studies using optokinetic stimulation have found either very small, variable, or inconsistent changes in heart rate and blood pressure, despite substantial symptoms of motion sickness. Furthermore, caloric stimulation severe enough to produce nystagmus, dizziness, and nausea had no effect on sympathetic nerve activity measured directly with microneurography. No effect was observed on heart rate, blood pressure, or plasma norepinephrine. Several factors may explain the apparent discordance of these results, but more research is needed before we can define the potential importance of vestibular input to cardiovascular regulation and orthostatic tolerance in humans.

Hearing Outcomes After Stereotactic Radiosurgery for Unilateral Intracanalicular Vestibular Schwannomas: Implication of Transient Volume Expansion

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

Kim, Young-Hoon; Department of Neurosurgery, Seoul National University College of Medicine, Seoul; Kim, Dong Gyu, E-mail: gknife@plaza.snu.ac.kr

2013-01-01

Purpose: We evaluated the prognostic factors for hearing outcomes after stereotactic radiosurgery (SRS) for unilateral sporadic intracanalicular vestibular schwannomas (IC-VSs) as a clinical homogeneous group of VSs. Methods and Materials: Sixty consecutive patients with unilateral sporadic IC-VSs, defined as tumors in the internal acoustic canal, and serviceable hearing (Gardner-Roberson grade 1 or 2) were treated with SRS as an initial treatment. The mean tumor volume was 0.34 {+-} 0.03 cm{sup 3} (range, 0.03-1.00 cm{sup 3}), and the mean marginal dose was 12.2 {+-} 0.1 Gy (range, 11.5-13.0 Gy). The median follow-up duration was 62 months (range, 36-141 months). Results: Themore » actuarial rates of serviceable hearing preservation were 70%, 63%, and 55% at 1, 2, and 5 years after SRS, respectively. In multivariate analysis, transient volume expansion of {>=}20% from initial tumor size was a statistically significant risk factor for loss of serviceable hearing and hearing deterioration (increase of pure tone average {>=}20 dB) (odds ratio = 7.638; 95% confidence interval, 2.317-25.181; P=.001 and odds ratio = 3.507; 95% confidence interval, 1.228-10.018; P=.019, respectively). The cochlear radiation dose did not reach statistical significance. Conclusions: Transient volume expansion after SRS for VSs seems to be correlated with hearing deterioration when defined properly in a clinically homogeneous group of patients.« less

Bilaterally Abnormal Head Impulse Tests Indicate a Large Cerebellopontine Angle Tumor.

PubMed

Kim, Hyo Jung; Park, Seong Ho; Kim, Ji Soo; Koo, Ja Won; Kim, Chae Yong; Kim, Young Hoon; Han, Jung Ho

2016-01-01

Tumors involving the cerebellopontine angle (CPA) pose a diagnostic challenge due to their diverse manifestations. Head impulse tests (HITs) have been used to evaluate vestibular function, but few studies have explored the head impulse gain of the vestibulo-ocular reflex (VOR) in patients with a vestibular schwannoma. This study tested whether the head impulse gain of the VOR is an indicator of the size of a unilateral CPA tumor. Twenty-eight patients (21 women; age=64±12 years, mean±SD) with a unilateral CPA tumor underwent a recording of the HITs using a magnetic search coil technique. Patients were classified into non-compressing (T1-T3) and compressing (T4) groups according to the Hannover classification. Most (23/28, 82%) of the patients showed abnormal HITs for the semicircular canals on the lesion side. The bilateral abnormality in HITs was more common in the compressing group than the non-compressing group (80% vs. 8%, Pearson's chi-square test: p<0.001). The tumor size was inversely correlated with the head impulse gain of the VOR in either direction. Bilaterally abnormal HITs indicate that a patient has a large unilateral CPA tumor. The abnormal HITs in the contralesional direction may be explained either by adaptation or by compression and resultant dysfunction of the cerebellar and brainstem structures. The serial evaluation of HITs may provide information on tumor growth, and thereby reduce the number of costly brain scans required when following up patients with CPA tumors.

[Amyotrophic neuralgia associated with bilateral phrenic paralysis treated with non-invasive mechanical ventilation].

PubMed

García García, María Del Carmen; Hernández Borge, Jacinto; Antona Rodríguez, María José; Pires Gonçalves, Pedro; García García, Gema

2015-09-07

Amyotrophic neuralgia is an uncommon neuropathy characterized by severe unilateral shoulder pain. Isolated or concomitant involvement of other peripheral motor nerves depending on the brachial plexus such as phrenic or laryngeal nerves is unusual(1). Its etiology is unknown, yet several explanatory factors have been proposed. Phrenic nerve involvement, either unilateral or bilateral, is exceedingly rare. Diagnosis relies on anamnesis, functional and imaging investigations and electromyogram. We report the case of a 48-year-old woman with a past history of renal transplantation due to proliferative glomerulonephritis with subsequent transplant rejection, who was eventually diagnosed with amyotrophic neuralgia with bilateral phrenic involvement, and who required sustained non-invasive mechanical ventilation. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

Translabyrinthine surgery for disabling vertigo in vestibular schwannoma patients.

PubMed

Godefroy, W P; Hastan, D; van der Mey, A G L

2007-06-01

To determine the impact of translabyrinthine surgery on the quality of life in vestibular schwannoma patients with rotatory vertigo. Prospective study in 18 vestibular schwannoma patients. The study was conducted in a multispecialty tertiary care clinic. All 18 patients had a unilateral intracanalicular vestibular schwannoma, without serviceable hearing in the affected ear and severely handicapped by attacks of rotatory vertigo and constant dizziness. Despite an initial conservative treatment, extensive vestibular rehabilitation exercises, translabyrinthine surgery was performed because of the disabling character of the vertigo, which considerably continued to affect the patients' quality of life. Preoperative and postoperative quality of life using the Short Form 36 Health Survey (Short Form-36) scores and Dizziness Handicap Inventory (DHI) scores. A total of 17 patients (94%) completed the questionnaire preoperatively and 3 and 12 months postoperatively. All Short Form-36 scales of the studied patients scored significantly lower when compared with the healthy Dutch control sample (P < 0.05). There was a significant improvement of DHI total scores and Short Form-36 scales on physical and social functioning, role-physical functioning, role-emotional functioning, mental health and general health at 12 months after surgery when compared with preoperative scores (P < 0.05). Vestibular schwannoma patients with disabling vertigo, experience significant reduced quality of life when compared with a healthy Dutch population. Translabyrinthine tumour removal significantly improved the patients' quality of life. Surgical treatment should be considered in patients with small- or medium-sized tumours and persisting disabling vertigo resulting in a poor quality of life.

Diplopia as the primary presentation of foodborne botulism.

PubMed

Khakshoor, Hamid; Moghaddam, Ali Akbar Saber; Vejdani, Amir Hossein; Armstrong, Blair K; Moshirfar, Majid

2012-05-01

Foodborne botulism is a serious condition caused by Clostridium botulinum neurotoxin. Clinically, botulism presents as bilateral cranial nerve neuropathy and descending paralysis. We report a unique presentation of botulism to remind clinicians of this potentially fatal condition. In this observational case report initial evaluation showed only esodeviation. This progressed to unilateral cranial nerve six (CN VI) paresis along with systemic signs. Clinical diagnosis was made based on in-depth history and concurrent symptoms in three other patients. Foodborne botulism presenting as diplopia and unilateral motility deficits is rare and can represent a diagnostic and therapeutic challenge to the ophthalmologist.

Diplopia as the primary presentation of foodborne botulism

PubMed Central

Khakshoor, Hamid; Moghaddam, Ali Akbar Saber; Vejdani, Amir Hossein; Armstrong, Blair K.; Moshirfar, Majid

2012-01-01

Foodborne botulism is a serious condition caused by Clostridium botulinum neurotoxin. Clinically, botulism presents as bilateral cranial nerve neuropathy and descending paralysis. We report a unique presentation of botulism to remind clinicians of this potentially fatal condition. In this observational case report initial evaluation showed only esodeviation. This progressed to unilateral cranial nerve six (CN VI) paresis along with systemic signs. Clinical diagnosis was made based on in-depth history and concurrent symptoms in three other patients. Foodborne botulism presenting as diplopia and unilateral motility deficits is rare and can represent a diagnostic and therapeutic challenge to the ophthalmologist. PMID:22993467

Unilateral Punctate Keratitis Secondary to Wallenberg Syndrome

PubMed Central

Boto, Ana; Del Hierro, Almudena; Capote, Maria; Noval, Susana; Garcia, Amanda; Santiago, Susana

2014-01-01

We studied three patients who developed left unilateral punctate keratitis after suffering left-sided Wallenberg Syndrome. A complex evolution occurred in two of them. In all cases, neurophysiological studies showed damage in the trigeminal sensory component at the bulbar level. Corneal involvement secondary to Wallenberg syndrome is a rare cause of unilateral superficial punctate keratitis. The loss of corneal sensitivity caused by trigeminal neuropathy leads to epithelial erosions that are frequently unobserved by the patient, resulting in a high risk of corneal-ulcer development with the possibility of superinfection. Neurophysiological studies can help to locate the anatomical level of damage at the ophthalmic branch of the trigeminal nerve, confirming the suspected etiology of stroke, and demonstrating that prior vascular involvement coincides with the location of trigeminal nerve damage. In some of these patients, oculofacial pain is a distinctive feature. PMID:24882965

A pathway in the brainstem for roll-tilt of the subjective visual vertical: evidence from a lesion-behavior mapping study.

PubMed

Baier, Bernhard; Thömke, Frank; Wilting, Janine; Heinze, Caroline; Geber, Christian; Dieterich, Marianne

2012-10-24

The perceived subjective visual vertical (SVV) is an important sign of a vestibular otolith tone imbalance in the roll plane. Previous studies suggested that unilateral pontomedullary brainstem lesions cause ipsiversive roll-tilt of SVV, whereas pontomesencephalic lesions cause contraversive roll-tilts of SVV. However, previous data were of limited quality and lacked a statistical approach. We therefore tested roll-tilt of the SVV in 79 human patients with acute unilateral brainstem lesions due to stroke by applying modern statistical lesion-behavior mapping analysis. Roll-tilt of the SVV was verified to be a brainstem sign, and for the first time it was confirmed statistically that lesions of the medial longitudinal fasciculus (MLF) and the medial vestibular nucleus are associated with ipsiversive tilt of the SVV, whereas contraversive tilts are associated with lesions affecting the rostral interstitial nucleus of the MLF, the superior cerebellar peduncle, the oculomotor nucleus, and the interstitial nucleus of Cajal. Thus, these structures constitute the anatomical pathway in the brainstem for verticality perception. Present data indicate that graviceptive otolith signals present a predominant role in the multisensory system of verticality perception.

Transnasal Endoscopic Optic Nerve Decompression in Post Traumatic Optic Neuropathy.

PubMed

Gupta, Devang; Gadodia, Monica

2018-03-01

To quantify the successful outcome in patients following optic nerve decompression in post traumatic unilateral optic neuropathy in form of improvement in visual acuity. A prospective study was carried out over a period of 5 years (January 2011 to June 2016) at civil hospital Ahmedabad. Total 20 patients were selected with optic neuropathy including patients with direct and indirect trauma to unilateral optic nerve, not responding to conservative management, leading to optic neuropathy and subsequent impairment in vision and blindness. Decompression was done via Transnasal-Ethmo-sphenoidal route and outcome was assessed in form of post-operative visual acuity improvement at 1 month, 6 months and 1 year follow up. After surgical decompression complete recovery of visual acuity was achieved in 16 (80%) patients and partial recovery in 4 (20%). Endoscopic transnasal approach is beneficial in traumatic optic neuropathy not responding to steroid therapy and can prevent permanent disability if earlier intervention is done prior to irreversible damage to the nerve. Endoscopic optic nerve surgery can decompress the traumatic and oedematous optic nerve with proper exposure of orbital apex and optic canal without any major intracranial, intraorbital and transnasal complications.

Constriction of the buccal branch of the facial nerve produces unilateral craniofacial allodynia.

PubMed

Lewis, Susannah S; Grace, Peter M; Hutchinson, Mark R; Maier, Steven F; Watkins, Linda R

2017-08-01

Despite pain being a sensory experience, studies of spinal cord ventral root damage have demonstrated that motor neuron injury can induce neuropathic pain. Whether injury of cranial motor nerves can also produce nociceptive hypersensitivity has not been addressed. Herein, we demonstrate that chronic constriction injury (CCI) of the buccal branch of the facial nerve results in long-lasting, unilateral allodynia in the rat. An anterograde and retrograde tracer (3000MW tetramethylrhodamine-conjugated dextran) was not transported to the trigeminal ganglion when applied to the injury site, but was transported to the facial nucleus, indicating that this nerve branch is not composed of trigeminal sensory neurons. Finally, intracisterna magna injection of interleukin-1 (IL-1) receptor antagonist reversed allodynia, implicating the pro-inflammatory cytokine IL-1 in the maintenance of neuropathic pain induced by facial nerve CCI. These data extend the prior evidence that selective injury to motor axons can enhance pain to supraspinal circuits by demonstrating that injury of a facial nerve with predominantly motor axons is sufficient for neuropathic pain, and that the resultant pain has a neuroimmune component. Copyright © 2016 Elsevier Inc. All rights reserved.

Bilateral LMAN lesions cancel differences in HVC neuronal recruitment induced by unilateral syringeal denervation. Lateral magnocellular nucleus of the anterior neostriatum.

PubMed

Wilbrecht, L; Petersen, T; Nottebohm, F

2002-12-01

Twenty-six-day-old male zebra finches received (1) unilateral section of their tracheosyringeal nerve, (2) bilateral lesions of the lateral magnocellular nucleus of the anterior neostriatum (LMAN), and (3) both operations. All birds were kept with an adult, singing male as a tutor until day 65. Tracheo-syringeal nerve-cut birds were able to imitate this model, but LMAN-lesioned birds were not. Bromodeoxyuridine, a marker of cell division, was injected intramuscularly during post-hatching days 61-65 and all birds were killed at 91 days of age. The number of bromodeoxyuridine+ neurons in the high vocal center of the tracheosyringeal-cut birds was twice as high in the intact as in the nerve cut side. This asymmetry disappeared when nerve section was combined with bilateral LMAN lesions. The latter operation, by itself, had no effect on new neuron counts. We suggest that the single nerve cut produced a hemispheric asymmetry in learning, reflected in new neuron recruitment, which disappeared when LMAN lesions blocked learning.

Stop the World from Spinning | NIH MedlinePlus the Magazine

MedlinePlus

... are using a device based on the same technology found in a cochlear implant to stop a Ménière's attack by restoring a stable pattern of electrical activity in the vestibular nerve of the damaged ...

Sonographic evaluation of sciatic nerves in patients with unilateral sciatica.

PubMed

Kara, Murat; Özçakar, Levent; Tiftik, Tülay; Kaymak, Bayram; Özel, Sumru; Akkuş, Selami; Akinci, Ayşen

2012-09-01

To evaluate the sciatic nerves of patients with unilateral sciatica by using an ultrasound, and to determine whether ultrasonographic findings were related to clinical and electrophysiologic parameters. Cross-sectional study. Physical medicine and rehabilitation departments of a university hospital and a rehabilitation hospital. Consecutive patients (N=30; 10 men, 20 women) with complaints of low back pain and unilateral sciatica of more than 1 month of duration were enrolled. Not applicable. All patients underwent a substantial clinical assessment, and they were also evaluated by electromyogram and magnetic resonance imaging. Pain was evaluated by a visual analog scale and the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) Scale. A linear array probe (7.5-12MHz) was used to scan sciatic nerves bilaterally in the prone position. Sciatic nerve diameters-thickness (short axis) and width (long axis)-and cross-sectional areas were measured bilaterally at the same levels, proximal to the bifurcation and midthigh. The values pertaining to the unaffected limbs were taken as controls. When compared with the unaffected sides, mean values for sciatic nerve measurements-long axis at bifurcation level (P=.017) and cross-sectional area at midthigh level (P=.005)-were significantly larger on the affected sides. Swelling ratios negatively correlated with symptom duration (r=-.394, P=.038) and LANSS scores (r=-.451, P=.016) at only midthigh level. Sciatic nerves seem to be enlarged on the side of sciatica in patients with low back pain. Our preliminary results may provide insight into better understanding the lower limb radiating pain in this group of patients. Copyright © 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Phrenic and hypoglossal nerve activity during respiratory response to hypoxia in 6-OHDA unilateral model of Parkinson's disease.

PubMed

Andrzejewski, Kryspin; Budzińska, Krystyna; Kaczyńska, Katarzyna

2017-07-01

Parkinson's disease (PD) patients apart from motor dysfunctions exhibit respiratory disturbances. Their mechanism is still unknown and requires investigation. Our research was designed to examine the activity of phrenic (PHR) and hypoglossal (HG) nerves activity during a hypoxic respiratory response in the 6-hydroxydopamine (6-OHDA) model of PD. Male adult Wistar rats were injected unilaterally with 6-OHDA (20μg) or the vehicle into the right medial forebrain bundle (MFB). Two weeks after the surgery the activity of the phrenic and hypoglossal nerve was registered in anesthetized, vagotomized, paralyzed, and mechanically ventilated rats under normoxic and hypoxic conditions. Lesion effectiveness was confirmed by the cylinder test, performed before the MFB injection and 14days after, before the respiratory experiment. 6-OHDA lesioned animals showed a significant increase in normoxic inspiratory time. Expiratory time and total time of the respiratory cycle were prolonged in PD rats after hypoxia. The amplitude of the PHR activity and its minute activity were increased in comparison to the sham group at recovery time and during 30s of hypoxia. The amplitude of the HG activity was increased in response to hypoxia in 6-OHDA lesioned animals. The degeneration of dopaminergic neurons decreased the pre-inspiratory/inspiratory ratio of the hypoglossal burst amplitude during and after hypoxia. Unilateral MFB lesion changed the activity of the phrenic and hypoglossal nerves. The altered pre-inspiratory hypoglossal nerve activity indicates modifications to the central mechanisms controlling the activity of the HG nerve and may explain respiratory disorders seen in PD, i.e. apnea. Copyright © 2017 Elsevier Inc. All rights reserved.

The cellular localization of the neuropeptides substance P, neurokinin A, calcitonin gene-related peptide and neuropeptide Y in guinea-pig vestibular sensory organs: a high-resolution confocal microscopy study.

PubMed

Scarfone, E; Ulfendahl, M; Lundeberg, T

1996-11-01

Four neuropeptides, substance P, neurokinin A, calcitonin gene-related peptide and neuropeptide Y, were detected by radioimmunoassay in guinea-pig vestibular end-organs. High-resolution confocal microscopy visualization of immunofluorescence staining was used to determine the cellular localization of these peptides. Substance P- and neurokinin A-like immunoreactivities were found to co-exist in afferent fibers innervating the peripheral regions of both the utricular and ampullar sensory organs. The immunoreactivity was more concentrated in the distal ends of the calyceal-shaped nerve endings that innervate type I sensory cells. While in the guinea-pig, nerve calyces and type I cells are distributed in both the central and peripheral regions of the sensory epithelia, immunoreactive calyces were found only in the peripheral regions. Calcitonin gene-related peptide-like immunoreactivity was localized in small bouton endings situated at the level of the base of the hair cells. These boutons were in a position to make axosomatic contacts with type II sensory cells and axodendritic contacts with afferent nerve endings. Calcitonin gene-related peptide immunoreactivity co-existed with choline acetyltransferase immunoreactivity. The localization and shape of these boutons identified them as the axonal endings of efferent vestibular fibers. Neuropeptide Y-like immunoreactivity was not observed in the actual sensory epithelium but in the underlying connective tissue, where it was located in varicose fibers along blood vessels. The synaptic position of the tachykinins is clearly distinct from that of calcitonin gene-related peptide. This segregation distinguishes the vestibular end-organs from most peripheral tissues where these peptides are co-localized. The tachykinin-immunoreactive afferent fibers are postsynaptic to the hair cells. If, as in somatic sensory endings, these fibers can be triggered to release the neuropeptides by an axon reflex type of activation, then the tachykinins could interfere directly with the function of type I and type II vestibular hair cells. Calcitonin gene-related peptide co-exists with acetylcholine in the efferent axonal endings that are presynaptic to type II hair cells and to afferent fibers. Calcitonin gene-related peptide can thus interfere by direct synaptic action with type II hair cells only. It may also regulate the activity of the tachykinin-containing afferents.

Multiple Lower Extremity Mononeuropathies by Segmental Schwannomatosis: A Case Report

PubMed Central

Kwon, Na Yeon; Oh, Hyun-Mi

2015-01-01

Schwannoma is an encapsulated nerve sheath tumor that is distinct from neurofibromatosis. It is defined as the occurrence of multiple schwannomas without any bilateral vestibular schwannomas. A 46-year-old man with multiple schwannomas involving peripheral nerves of the ipsilateral lower extremity presented with neurologic symptoms. Electrodiagnostic studies revealed multiple mononeuropathies involving the left sciatic, common peroneal, tibial, femoral and superior gluteal nerves. Histologic findings confirmed the diagnosis of schwannoma. We reported this rare case of segmental schwannomatosis that presented with neurologic symptoms including motor weakness, which was confirmed as multiple mononeuropathies by electrodiagnostic studies. PMID:26605183

Multiple Lower Extremity Mononeuropathies by Segmental Schwannomatosis: A Case Report.

PubMed

Kwon, Na Yeon; Oh, Hyun-Mi; Ko, Young Jin

2015-10-01

Schwannoma is an encapsulated nerve sheath tumor that is distinct from neurofibromatosis. It is defined as the occurrence of multiple schwannomas without any bilateral vestibular schwannomas. A 46-year-old man with multiple schwannomas involving peripheral nerves of the ipsilateral lower extremity presented with neurologic symptoms. Electrodiagnostic studies revealed multiple mononeuropathies involving the left sciatic, common peroneal, tibial, femoral and superior gluteal nerves. Histologic findings confirmed the diagnosis of schwannoma. We reported this rare case of segmental schwannomatosis that presented with neurologic symptoms including motor weakness, which was confirmed as multiple mononeuropathies by electrodiagnostic studies.

Loss of α-calcitonin gene-related peptide (αCGRP) reduces the efficacy of the Vestibulo-ocular Reflex (VOR).

PubMed

Luebke, Anne E; Holt, Joseph C; Jordan, Paivi M; Wong, Yi Shan; Caldwell, Jillian S; Cullen, Kathleen E

2014-07-30

The neuroactive peptide calcitonin-gene related peptide (CGRP) is known to act at efferent synapses and their targets in hair cell organs, including the cochlea and lateral line. CGRP is also expressed in vestibular efferent neurons as well as a number of central vestibular neurons. Although CGRP-null (-/-) mice demonstrate a significant reduction in cochlear nerve sound-evoked activity compared with wild-type mice, it is unknown whether and how the loss of CGRP influence vestibular system function. Vestibular function was assessed by quantifying the vestibulo-ocular reflex (VOR) in alert mice. The loss of CGRP in (-/-) mice was associated with a reduction of the VOR gain of ≈50% without a concomitant change in phase. Using immunohistochemistry, we confirmed that, although CGRP staining was absent in the vestibular end-organs of null (-/-) mice, cholinergic staining appeared normal, suggesting that the overall gross development of vestibular efferent innervation was unaltered. We further confirmed that the observed deficit in vestibular function of null (-/-) mice was not the result of nontargeted effects at the level of the extraocular motor neurons and/or their innervation of extraocular muscles. Analysis of the relationship between vestibular quick phase amplitude and peak velocity revealed that extraocular motor function was unchanged, and immunohistochemistry revealed no abnormalities in motor endplates. Together, our findings show that the neurotransmitter CGRP plays a key role in ensuring VOR efficacy. Copyright © 2014 the authors 0270-6474/14/3410453-06$15.00/0.

Trigeminal Proprioception Evoked by Strong Stretching of the Mechanoreceptors in Müller's Muscle Induces Reflex Contraction of the Orbital Orbicularis Oculi Slow-Twitch Muscle Fibers.

PubMed

Matsuo, Kiyoshi; Ban, Ryokuya; Ban, Midori; Yuzuriha, Shunsuke

2014-01-01

The mixed orbicularis oculi muscle lacks an intramuscular proprioceptive system such as muscle spindles, to induce reflex contraction of its slow-twitch fibers. We evaluated whether the mechanoreceptors in Müller's muscle function as extrinsic mechanoreceptors to induce reflex contraction of the slow-twitch fibers of the orbicularis oculi in addition to those of the levator and frontalis muscles. We evaluated in patients with aponeurosis-disinserted blepharoptosis whether strong stretching of the mechanoreceptors in Müller's muscle from upgaze with unilateral lid load induced reflex contraction of the orbicularis oculi slow-twitch fibers and whether anesthesia of Müller's muscle precluded the contraction. We compared the electromyographic responses of the bilateral orbicularis oculi muscles to unilateral intraoperative direct stimulation of the trigeminal proprioceptive nerve with those to unilateral transcutaneous electrical stimulation of the supraorbital nerve. Upgaze with a unilateral 3-g lid load induced reflex contraction of the bilateral orbicularis oculi muscles with ipsilateral dominance. Anesthesia of Müller's muscle precluded the reflex contraction. The orbicularis oculi reflex evoked by stimulation of the trigeminal proprioceptive nerve differed from that by electrical stimulation of the supraorbital nerve in terms of the intensity of current required to induce the reflex, the absence of R1, and duration. The mechanoreceptors in Müller's muscle functions as an extramuscular proprioceptive system to induce reflex contraction of the orbital orbicularis oculi slow-twitch fibers. Whereas reflex contraction of the pretarsal orbicularis fast-twitch fibers functions in spontaneous or reflex blinking, that of the orbital orbicularis oculi slow-twitch fibers may factor in grimacing and blepharospasm.

Trigeminal Proprioception Evoked by Strong Stretching of the Mechanoreceptors in Müller's Muscle Induces Reflex Contraction of the Orbital Orbicularis Oculi Slow-Twitch Muscle Fibers

PubMed Central

Ban, Ryokuya; Ban, Midori; Yuzuriha, Shunsuke

2014-01-01

Objective: The mixed orbicularis oculi muscle lacks an intramuscular proprioceptive system such as muscle spindles, to induce reflex contraction of its slow-twitch fibers. We evaluated whether the mechanoreceptors in Müller's muscle function as extrinsic mechanoreceptors to induce reflex contraction of the slow-twitch fibers of the orbicularis oculi in addition to those of the levator and frontalis muscles. Methods: We evaluated in patients with aponeurosis-disinserted blepharoptosis whether strong stretching of the mechanoreceptors in Müller's muscle from upgaze with unilateral lid load induced reflex contraction of the orbicularis oculi slow-twitch fibers and whether anesthesia of Müller's muscle precluded the contraction. We compared the electromyographic responses of the bilateral orbicularis oculi muscles to unilateral intraoperative direct stimulation of the trigeminal proprioceptive nerve with those to unilateral transcutaneous electrical stimulation of the supraorbital nerve. Results: Upgaze with a unilateral 3-g lid load induced reflex contraction of the bilateral orbicularis oculi muscles with ipsilateral dominance. Anesthesia of Müller's muscle precluded the reflex contraction. The orbicularis oculi reflex evoked by stimulation of the trigeminal proprioceptive nerve differed from that by electrical stimulation of the supraorbital nerve in terms of the intensity of current required to induce the reflex, the absence of R1, and duration. Conclusions: The mechanoreceptors in Müller's muscle functions as an extramuscular proprioceptive system to induce reflex contraction of the orbital orbicularis oculi slow-twitch fibers. Whereas reflex contraction of the pretarsal orbicularis fast-twitch fibers functions in spontaneous or reflex blinking, that of the orbital orbicularis oculi slow-twitch fibers may factor in grimacing and blepharospasm. PMID:25210572

PLCγ-activated signalling is essential for TrkB mediated sensory neuron structural plasticity

PubMed Central

2010-01-01

Background The vestibular system provides the primary input of our sense of balance and spatial orientation. Dysfunction of the vestibular system can severely affect a person's quality of life. Therefore, understanding the molecular basis of vestibular neuron survival, maintenance, and innervation of the target sensory epithelia is fundamental. Results Here we report that a point mutation at the phospholipase Cγ (PLCγ) docking site in the mouse neurotrophin tyrosine kinase receptor TrkB (Ntrk2) specifically impairs fiber guidance inside the vestibular sensory epithelia, but has limited effects on the survival of vestibular sensory neurons and growth of afferent processes toward the sensory epithelia. We also show that expression of the TRPC3 cation calcium channel, whose activity is known to be required for nerve-growth cone guidance induced by brain-derived neurotrophic factor (BDNF), is altered in these animals. In addition, we find that absence of the PLCγ mediated TrkB signalling interferes with the transformation of bouton type afferent terminals of vestibular dendrites into calyces (the largest synaptic contact of dendrites known in the mammalian nervous system) on type I vestibular hair cells; the latter are normally distributed in these mutants as revealed by an unaltered expression pattern of the potassium channel KCNQ4 in these cells. Conclusions These results demonstrate a crucial involvement of the TrkB/PLCγ-mediated intracellular signalling in structural aspects of sensory neuron plasticity. PMID:20932311

Effects of bilateral vestibular nucleus lesions on cardiovascular regulation in conscious cats.

PubMed

Mori, R L; Cotter, L A; Arendt, H E; Olsheski, C J; Yates, B J

2005-02-01

The vestibular system participates in cardiovascular regulation during postural changes. In prior studies (Holmes MJ, Cotter LA, Arendt HE, Cas SP, and Yates BJ. Brain Res 938: 62-72, 2002, and Jian BJ, Cotter LA, Emanuel BA, Cass SP, and Yates BJ. J Appl Physiol 86: 1552-1560, 1999), transection of the vestibular nerves resulted in instability in blood pressure during nose-up body tilts, particularly when no visual information reflecting body position in space was available. However, recovery of orthostatic tolerance occurred within 1 wk, presumably because the vestibular nuclei integrate a variety of sensory inputs reflecting body location. The present study tested the hypothesis that lesions of the vestibular nuclei result in persistent cardiovascular deficits during orthostatic challenges. Blood pressure and heart rate were monitored in five conscious cats during nose-up tilts of varying amplitude, both before and after chemical lesions of the vestibular nuclei. Before lesions, blood pressure remained relatively stable during tilts. In all animals, the blood pressure responses to nose-up tilts were altered by damage to the medial and inferior vestibular nuclei; these effects were noted both when animals were tested in the presence and absence of visual feedback. In four of the five animals, the lesions also resulted in augmented heart rate increases from baseline values during 60 degrees nose-up tilts. These effects persisted for longer than 1 wk, but they gradually resolved over time, except in the animal with the worst deficits. These observations suggest that recovery of compensatory cardiovascular responses after loss of vestibular inputs is accomplished at least in part through plastic changes in the vestibular nuclei and the enhancement of the ability of vestibular nucleus neurons to discriminate body position in space by employing nonlabyrinthine signals.

Amiodarone-associated bilateral vestibulopathy.

PubMed

Gürkov, Robert; Manzari, Leonardo; Blödow, Alexander; Wenzel, Angela; Pavlovic, Dusan; Luis, Leonal

2018-03-01

Bilateral vestibulopathy (BVP) is a debilitating disorder characterized by the hypofunction of both vestibular end organs or nerves. The most frequent identifiable causes of BVP are ototoxic drug effects, infectious and autoimmune disorders. The majority of cases, however, remain idiopathic. Medical records of patients diagnosed with idiopathic BVP were examined in five dizziness clinics. We identified 126 patients with "idiopathic" BVP. Out of these, 15 patients had a history of Amiodarone treatment before the diagnosis of BVP, resulting in a 12% prevalence. The present report supports the hypothesis that Amiodarone can cause BVP. Vestibular examination in patients taking Amiodarone and suffering from balance-related symptoms are recommended, to recognize this adverse effect as early as possible and allow for an informed judgement on a potential dose reduction or withdrawal for recovery of the vestibular function.

Peripheral nerve blocks for the treatment of short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) during pregnancy.

PubMed

Yalın, Osman Özgür; Uludüz, Derya; Özge, Aynur

2018-01-01

Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) is a rare, primary headache syndrome, which is classified as a subtype of trigeminal autonomic cephalalgias. Although SUNCT is usually refractory to treatment, several antiepileptic drugs have recently shown promising results for its treatment. However, there is a lack of evidence regarding the course of SUNCT during pregnancy and the available treatment options. Here, we present a 30-week pregnant female with SUNCT who was successfully treated with infra- and supraorbital nerve blocks. Headache attacks completely diminished after the injection, and recurrence was not observed. Although lamotrigine may be relatively safe in pregnant patients with SUNCT attacks, peripheral nerve block may be a feasible technique and can be considered as a safe and effective treatment option. This is the first SUNCT case in the literature that was successfully treated with infra- and supraorbital nerve blocks during pregnancy.

Vestibular effects of cochlear implantation.

PubMed

Buchman, Craig A; Joy, Jennifer; Hodges, Annelle; Telischi, Fred F; Balkany, Thomas J

2004-10-01

Cochlear implantation (CI) carries with it the potential risk for vestibular system insult or stimulation with resultant dysfunction. As candidate profiles continue to evolve and with the recent development of bilateral CI, understanding the significance of this risk takes on an increasing importance. Between 1997 to 2001, a prospective observational study was carried out in a tertiary care medical center to assess the effects of unilateral CI on the vestibular system. Assessment was performed using the dizziness handicap inventory (DHI), vestibulo-ocular reflex (VOR) testing using both alternate bithermal caloric irrigations (ENG) and rotational chair-generated sinusoidal harmonic accelerations (SHA), and computerized dynamic platform posturography (CDP) at preoperative, 1-month, 4-month, 1-year and 2-year postimplantation visits. CI was carried out without respect to the preoperative vestibular function test results. Specifically, 86 patients were entered into the study after informed consent. For the group as a whole, pair wise comparisons revealed few significant differences between preoperative and postoperative values for VOR testing (ENG and SHA) at any of the follow-up intervals. Likewise, DHI testing was also unchanged except for significant reductions (improvements) in the emotional subcategory scores at both the 4-month and 1-year intervals. CDP results demonstrated substantial improvements in postural sway in the vestibular conditions (5 and 6) as well as composite scores with the device "off" and "on" at the 1-month, 4-month, 1-year, and 2-year intervals. Device activation appeared to improve postural stability in some conditions. Excluding those patients with preoperative areflexic or hyporeflexic responses in the implanted ear (total [warm + cool] caloric response or=21 deg/s maximum slow phase velocity) in total caloric response were observed for 8 (29%) patients at the 4-month interval. These persisted throughout the study period. These changes were accompanied by significant low frequency phase changes on SHA testing confirming a VOR insult. Of interest, no significant changes were detected in the DHI or CDP, and there were no effects of age, sex, device manufacturer, or etiology of hearing loss (HL) for these patients. Unilateral CI rarely results in significant adverse effects on the vestibular system as measured by the DHI, ENG, SHA, and CDP. On the contrary, patients that underwent CI experienced significant improvements in the objective measures of postural stability as measured by CDP. Device activation in music appeared to have an additional positive effect on postural stability during CDP testing. Although VOR testing demonstrated some decreases in response, patients did not suffer from disabling vestibular effects following CI. The mechanism underlying these findings remains speculative. These findings should be considered in counseling patients about CI.

The video ocular counter-roll (vOCR): a clinical test to detect loss of otolith-ocular function

PubMed Central

Otero-Millan, Jorge; Treviño, Carolina; Winnick, Ariel; Zee, David S.; Carey, John P.; Kheradmand, Amir

2017-01-01

Conclusion vOCR can detect loss of otolith-ocular function without specifying the side of vestibular loss. Since vOCR is measured with a simple head tilt maneuver, it can be potentially used as a bedside clinical test in combination with video head impulse test. Objective Video-oculography (VOG) goggles are being integrated into the bedside assessment of patients with vestibular disorders. Lacking, however, is a method to evaluate otolith function. This study validated a VOG test for loss of otolith function. Methods VOG was used to measure ocular counter-roll (vOCR) in 12 healthy controls, 14 patients with unilateral vestibular loss (UVL), and six patients with bilateral vestibular loss (BVL) with a static lateral head tilt of 30°. The results were compared with vestibular evoked myogenic potentials (VEMP), a widely-used laboratory test of otolith function. Results The average vOCR for healthy controls (4.6°) was significantly different from UVL (2.7°) and BVL (1.6°) patients (p < 0.0001). The vOCR and VEMP measurements were correlated across subjects, especially the click and tap oVEMPs (click oVEMP R = 0.45, tap oVEMP R = 0.51; p < 0.0003). The receiver operator characteristic (ROC) analysis showed that vOCR and VEMPs detected loss of otolith function equally well. The best threshold for vOCR to detect vestibular loss was at 3°. The vOCR values from the side of vestibular loss and the healthy side were not different in UVL patients (2.53° vs 2.8°; p = 0.59). PMID:28084887

The Vestibular Effects of Repeated Low-Level Blasts.

PubMed

Littlefield, Philip D; Pinto, Robin L; Burrows, Holly L; Brungart, Douglas S

2016-01-01

The objective of this study was to use a prospective cohort of United States Marine Corps (USMC) instructors to identify any acute or long-term vestibular dysfunction following repeated blast exposures during explosive breaching training. They were assessed in clinic and on location during training at the USMC Methods of Entry School, Quantico, VA. Subjects received comprehensive baseline vestibular assessments and these were repeated in order to identify longitudinal changes. They also received shorter assessments immediately following blast exposure in order to identify acute findings. The main outcome measures were the Neurobehavioral Symptom Inventory, vestibular Visual Analog Scale (VAS) of subjective vestibular function, videonystagmography (VNG), vestibular evoked myogenic potentials (VEMP), rotary chair (including the unilateral centrifugation test), computerized dynamic posturography, and computerized dynamic visual acuity. A total of 11 breachers and 4 engineers were followed for up to 17 months. No acute effects or longitudinal deteriorations were identified, but there were some interesting baseline group differences. Upbeat positional nystagmus was common, and correlated (p<0.005) with a history of mild traumatic brain injury (mTBI). Several instructors had abnormally short low-frequency phase leads on rotary chair testing. This study evaluated breaching instructors over a longer test period than any other study, and the results suggest that this population appears to be safe from a vestibular standpoint at the current exposure levels. Upbeat positional nystagmus correlated with a history of mTBI in this population, and this has not been described elsewhere. The data trends also suggest that this nystagmus could be an acute blast effect. However, the reasons for the abnormally short phase leads seen in rotary chair testing are unclear at this time. Further investigation seems warranted.

Beyond Dizziness: Virtual Navigation, Spatial Anxiety and Hippocampal Volume in Bilateral Vestibulopathy

PubMed Central

Kremmyda, Olympia; Hüfner, Katharina; Flanagin, Virginia L.; Hamilton, Derek A.; Linn, Jennifer; Strupp, Michael; Jahn, Klaus; Brandt, Thomas

2016-01-01

Bilateral vestibulopathy (BVP) is defined as the impairment or loss of function of either the labyrinths or the eighth nerves. Patients with total BVP due to bilateral vestibular nerve section exhibit difficulties in spatial memory and navigation and show a loss of hippocampal volume. In clinical practice, most patients do not have a complete loss of function but rather an asymmetrical residual functioning of the vestibular system. The purpose of the current study was to investigate navigational ability and hippocampal atrophy in BVP patients with residual vestibular function. Fifteen patients with BVP and a group of age- and gender- matched healthy controls were examined. Self-reported questionnaires on spatial anxiety and wayfinding were used to assess the applied strategy of wayfinding and quality of life. Spatial memory and navigation were tested directly using a virtual Morris Water Maze Task. The hippocampal volume of these two groups was evaluated by voxel-based morphometry. In the patients, the questionnaire showed a higher spatial anxiety and the Morris Water Maze Task a delayed spatial learning performance. MRI revealed a significant decrease in the gray matter mid-hippocampal volume (Left: p = 0.006, Z = 4.58, Right: p < 0.001, Z = 3.63) and posterior parahippocampal volume (Right: p = 0.005, Z = 4.65, Left: p < 0.001, Z = 3.87) compared to those of healthy controls. In addition, a decrease in hippocampal formation volume correlated with a more dominant route-finding strategy. Our current findings demonstrate that even partial bilateral vestibular loss leads to anatomical and functional changes in the hippocampal formation and objective and subjective behavioral deficits. PMID:27065838

Virtual head rotation reveals a process of route reconstruction from human vestibular signals

PubMed Central

Day, Brian L; Fitzpatrick, Richard C

2005-01-01

The vestibular organs can feed perceptual processes that build a picture of our route as we move about in the world. However, raw vestibular signals do not define the path taken because, during travel, the head can undergo accelerations unrelated to the route and also be orientated in any direction to vary the signal. This study investigated the computational process by which the brain transforms raw vestibular signals for the purpose of route reconstruction. We electrically stimulated the vestibular nerves of human subjects to evoke a virtual head rotation fixed in skull co-ordinates and measure its perceptual effect. The virtual head rotation caused subjects to perceive an illusory whole-body rotation that was a cyclic function of head-pitch angle. They perceived whole-body yaw rotation in one direction with the head pitched forwards, the opposite direction with the head pitched backwards, and no rotation with the head in an intermediate position. A model based on vector operations and the anatomy and firing properties of semicircular canals precisely predicted these perceptions. In effect, a neural process computes the vector dot product between the craniocentric vestibular vector of head rotation and the gravitational unit vector. This computation yields the signal of body rotation in the horizontal plane that feeds our perception of the route travelled. PMID:16002439

The Vestibular System Implements a Linear–Nonlinear Transformation In Order to Encode Self-Motion

PubMed Central

Massot, Corentin; Schneider, Adam D.; Chacron, Maurice J.; Cullen, Kathleen E.

2012-01-01

Although it is well established that the neural code representing the world changes at each stage of a sensory pathway, the transformations that mediate these changes are not well understood. Here we show that self-motion (i.e. vestibular) sensory information encoded by VIIIth nerve afferents is integrated nonlinearly by post-synaptic central vestibular neurons. This response nonlinearity was characterized by a strong (∼50%) attenuation in neuronal sensitivity to low frequency stimuli when presented concurrently with high frequency stimuli. Using computational methods, we further demonstrate that a static boosting nonlinearity in the input-output relationship of central vestibular neurons accounts for this unexpected result. Specifically, when low and high frequency stimuli are presented concurrently, this boosting nonlinearity causes an intensity-dependent bias in the output firing rate, thereby attenuating neuronal sensitivities. We suggest that nonlinear integration of afferent input extends the coding range of central vestibular neurons and enables them to better extract the high frequency features of self-motion when embedded with low frequency motion during natural movements. These findings challenge the traditional notion that the vestibular system uses a linear rate code to transmit information and have important consequences for understanding how the representation of sensory information changes across sensory pathways. PMID:22911113

A patient with bilateral facial palsy associated with hypertension and chickenpox: learning points.

PubMed

Al-Abadi, Eslam; Milford, David V; Smith, Martin

2010-11-26

Bilateral facial nerve paralysis is an uncommon presentation and even more so in children. There are reports of different causes of bilateral facial nerve palsy. It is well-established that hypertension and chickenpox causes unilateral facial paralysis and the importance of checking the blood pressure in children with facial nerve paralysis cannot be stressed enough. The authors report a boy with bilateral facial nerve paralysis in association with hypertension and having recently recovered from chickenpox. The authors review aspects of bilateral facial nerve paralysis as well as hypertension and chickenpox causing facial nerve paralysis.

A patient with bilateral facial palsy associated with hypertension and chickenpox: learning points

PubMed Central

Al-Abadi, Eslam; Milford, David V; Smith, Martin

2010-01-01

Bilateral facial nerve paralysis is an uncommon presentation and even more so in children. There are reports of different causes of bilateral facial nerve palsy. It is well-established that hypertension and chickenpox causes unilateral facial paralysis and the importance of checking the blood pressure in children with facial nerve paralysis cannot be stressed enough. The authors report a boy with bilateral facial nerve paralysis in association with hypertension and having recently recovered from chickenpox. The authors review aspects of bilateral facial nerve paralysis as well as hypertension and chickenpox causing facial nerve paralysis. PMID:22797481

Differential central projections of vestibular afferents in pigeons

NASA Technical Reports Server (NTRS)

Dickman, J. D.; Fang, Q.

1996-01-01

The question of whether a differential distribution of vestibular afferent information to central nuclear neurons is present in pigeons was studied using neural tracer compounds. Discrete tracing of afferent fibers innervating the individual semicircular canal and otolith organs was produced by sectioning individual branches of the vestibular nerve that innervate the different receptor organs and applying crystals of horseradish peroxidase, or a horseradish peroxidase/cholera toxin mixture, or a biocytin compound for neuronal uptake and transport. Afferent fibers and their terminal distributions within the brainstem and cerebellum were visualized subsequently. Discrete areas in the pigeon central nervous system that receive primary vestibular input include the superior, dorsal lateral, ventral lateral, medial, descending, and tangential vestibular nuclei; the A and B groups; the intermediate, medial, and lateral cerebellar nuclei; and the nodulus, the uvula, and the paraflocculus. Generally, the vertical canal afferents projected heavily to medial regions in the superior and descending vestibular nuclei as well as the A group. Vertical canal projections to the medial and lateral vestibular nuclei were observed but were less prominent. Horizontal canal projections to the superior and descending vestibular nuclei were much more centrally located than those of the vertical canals. A more substantial projection to the medial and lateral vestibular nuclei was seen with horizontal canal afferents compared to vertical canal fibers. Afferents innervating the utricle and saccule terminated generally in the lateral regions of all vestibular nuclei in areas that were separate from the projections of the semicircular canals. In addition, utricular fibers projected to regions in the vestibular nuclei that overlapped with the horizontal semicircular canal terminal fields, whereas saccular afferents projected to regions that received vertical canal fiber terminations. Lagenar afferents projected throughout the cochlear nuclei, to the dorsolateral regions of the cerebellar nuclei, and to lateral regions of the superior, lateral, medial, and descending vestibular nuclei.

Current and Future Management of Bilateral Loss of Vestibular Sensation – An update on the Johns Hopkins Multichannel Vestibular Prosthesis Project

PubMed Central

Della Santina, Charles C.; Migliaccio, Americo A.; Hayden, Russell; Melvin, Thuy-Anh; Fridman, Gene Y.; Chiang, Bryce; Davidovics, Natan S.; Dai, Chenkai; Carey, John P.; Minor, Lloyd B.; Anderson, Iee-Ching; Park, HongJu; Lyford-Pike, Sofia; Tang, Shan

2012-01-01

Bilateral loss of vestibular sensation can disable individuals whose vestibular hair cells are injured by ototoxic medications, infection, Ménière’s disease or other insults to the labyrinth including surgical trauma during cochlear implantation. Without input to vestibulo-ocular and vestibulo-spinal reflexes that normally stabilize the eyes and body, affected patients suffer blurred vision during head movement, postural instability, and chronic disequilibrium. While individuals with some residual sensation often compensate for their loss through rehabilitation exercises, those who fail to do so are left with no adequate treatment options. An implantable neuroelectronic vestibular prosthesis that emulates the normal labyrinth by sensing head movement and modulating activity on appropriate branches of the vestibular nerve could significantly improve quality of life for these otherwise chronically dizzy patients. This brief review describes the impact and current management of bilateral loss of vestibular sensation, animal studies supporting the feasibility of prosthetic vestibular stimulation, and a vestibular prosthesis designed to restore sensation of head rotation in all directions. Similar to a cochlear implant in concept and size, the Johns Hopkins Multichannel Vestibular Prosthesis (MVP) includes miniature gyroscopes to sense head rotation, a microcontroller to process inputs and control stimulus timing, and current sources switched between pairs of electrodes implanted within the vestibular labyrinth. In rodents and rhesus monkeys rendered bilaterally vestibular-deficient via treatment with gentamicin and/or plugging of semicircular canals, the MVP partially restores the vestibulo-ocular reflex for head rotations about any axis of rotation in 3-dimensional space. Our efforts now focus on addressing issues prerequisite to human implantation, including refinement of electrode designs and surgical technique to enhance stimulus selectivity and preserve cochlear function, optimization of stimulus protocols, and reduction of device size and power consumption. PMID:21756683

Metastatic breast carcinoma presenting as unilateral pulsatile tinnitus: a case report.

PubMed

Moore, Andrew; Cunnane, Max; Fleming, Jason C

2015-02-01

Pulsatile tinnitus is a rare symptom, yet it may herald life-threatening pathology in the absence of other symptoms or signs. Pulsatile tinnitus tends to imply a vascular cause, but metastatic disease also can present in this way. Clinicians should therefore adopt a specific diagnostic algorithm for pulsatile tinnitus and always consider the possibility of metastatic disease. A history of malignant disease and new cranial nerve palsies should raise clinical suspicion for skull base metastases. We describe the case of a 63-year-old woman presenting with unilateral subjective pulsatile tinnitus and a middle ear mass visible on otoscopy. Her background included the diagnosis of idiopathic unilateral vagal and hypoglossal nerve palsies 4 years previously, with normal magnetic resonance imaging (MRI). Repeat MRI and computed tomography imaging were consistent with metastatic breast carcinoma. This case raises important questions about imaging protocols and the role of serial scanning in patients at high risk of metastatic disease.

Proton beam radiosurgery for vestibular schwannoma: tumor control and cranial nerve toxicity.

PubMed

Weber, Damien C; Chan, Annie W; Bussiere, Marc R; Harsh, Griffith R; Ancukiewicz, Marek; Barker, Fred G; Thornton, Allan T; Martuza, Robert L; Nadol, Joseph B; Chapman, Paul H; Loeffler, Jay S

2003-09-01

We sought to determine the tumor control rate and cranial nerve function outcomes in patients with vestibular schwannomas who were treated with proton beam stereotactic radiosurgery. Between November 1992 and August 2000, 88 patients with vestibular schwannomas were treated at the Harvard Cyclotron Laboratory with proton beam stereotactic radiosurgery in which two to four convergent fixed beams of 160-MeV protons were applied. The median transverse diameter was 16 mm (range, 2.5-35 mm), and the median tumor volume was 1.4 cm(3) (range, 0.1-15.9 cm(3)). Surgical resection had been performed previously in 15 patients (17%). Facial nerve function (House-Brackmann Grade 1) and trigeminal nerve function were normal in 79 patients (89.8%). Eight patients (9%) had good or excellent hearing (Gardner-Robertson [GR] Grade 1), and 13 patients (15%) had serviceable hearing (GR Grade 2). A median dose of 12 cobalt Gray equivalents (range, 10-18 cobalt Gray equivalents) was prescribed to the 70 to 108% isodose lines (median, 70%). The median follow-up period was 38.7 months (range, 12-102.6 mo). The actuarial 2- and 5-year tumor control rates were 95.3% (95% confidence interval [CI], 90.9-99.9%) and 93.6% (95% CI, 88.3-99.3%). Salvage radiosurgery was performed in one patient 32.5 months after treatment, and a craniotomy was required 19.1 months after treatment in another patient with hemorrhage in the vicinity of a stable tumor. Three patients (3.4%) underwent shunting for hydrocephalus, and a subsequent partial resection was performed in one of these patients. The actuarial 5-year cumulative radiological reduction rate was 94.7% (95% CI, 81.2-98.3%). Of the 21 patients (24%) with functional hearing (GR Grade 1 or 2), 7 (33.3%) retained serviceable hearing ability (GR Grade 2). Actuarial 5-year normal facial and trigeminal nerve function preservation rates were 91.1% (95% CI, 85-97.6%) and 89.4% (95% CI, 82-96.7%). Univariate analysis revealed that prescribed dose (P = 0.005), maximum dose (P = 0.006), and the inhomogeneity coefficient (P = 0.03) were associated with a significant risk of long-term facial neuropathy. No other cranial nerve deficits or cancer relapses were observed. Proton beam stereotactic radiosurgery has been shown to be an effective means of tumor control. A high radiological response rate was observed. Excellent facial and trigeminal nerve function preservation rates were achieved. A reduced prescribed dose is associated with a significant decrease in facial neuropathy.

The masseteric nerve: a versatile power source in facial animation techniques.

PubMed

Bianchi, B; Ferri, A; Ferrari, S; Copelli, C; Salvagni, L; Sesenna, E

2014-03-01

The masseteric nerve has many advantages including low morbidity, its proximity to the facial nerve, the strong motor impulse, its reliability, and the fast reinnervation that is achievable in most patients. Reinnervation of a neuromuscular transplant is the main indication for its use, but it has been used for the treatment of recent facial palsies with satisfactory results. We have retrospectively evaluated 60 patients who had facial animation procedures using the masseteric nerve during the last 10 years. The patients included those with recent, and established or congenital, unilateral and bilateral palsies. The masseteric nerve was used for coaptation of the facial nerve either alone or in association with crossfacial nerve grafting, or for the reinnervation of gracilis neuromuscular transplants. Reinnervation was successful in all cases, the mean (range) time being 4 (2-5) months for facial nerve coaptation and 4 (3-7) months for neuromuscular transplants. Cosmesis was evaluated (moderate, n=10, good, n=30, and excellent, n=20) as was functional outcome (no case of impairment of masticatory function, all patients able to smile, and achievement of a smile independent from biting). The masseteric nerve has many uses, including in both recent, and established or congenital, cases. In some conditions it is the first line of treatment. The combination of combined techniques gives excellent results in unilateral palsies and should therefore be considered a valid option. Copyright © 2014 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

[Proven and innovative operative techniques for reanimation of the paralyzed face].

PubMed

Frey, M; Michaelidou, M; Tzou, C-H J; Hold, A; Pona, I; Placheta, E

2010-04-01

This overview on the currently most effective reconstructive techniques for reanimation of the unilaterally or bilaterally paralysed face includes all important techniques of neuromuscular reconstruction as well as of supplementary static procedures, which contribute significantly to the efficiency and quality of the functional overall result. Attention is paid to the best indications at the best time since onset of the facial palsy, depending on the age of the patient, the cause of the lesion, and the compliance of the patient for a long-lasting and complex rehabilitation programme. Immediate neuromuscular reconstruction of mimic function is favourable by nerve suture or nerve grafting of the facial nerve, or by using the contralateral healthy facial nerve via cross-face nerve grafting as long as the time since onset of the irreversible palsy is short enough that the paralysed mimic muscles can still be reinnervated. For the most frequent indication, the unilateral irreversible and complete palsy, a three-stage concept is described including cross-face nerve grafting, free functional gracilis muscle transplantation, and several supplementary procedures. In patients with limited life expectancy, transposition of the masseteric muscles is favoured. Bilateral facial palsy is treated by bilateral free gracilis muscle transplantation with the masseteric nerve branches for motor reinnervation. Functional upgrading in incomplete lesions is achieved by cross-face nerve grafting with distal end-to-side neurorrhaphy or by functional muscle transplantation with ipsilateral facial nerve supply. (c) Georg Thieme Verlag KG Stuttgart-New York.

Vestibular evoked myogenic potential (VEMP) in patients with Ménière's disease with drop attacks.

PubMed

Timmer, Ferdinand C A; Zhou, Guangwei; Guinan, John J; Kujawa, Sharon G; Herrmann, Barbara S; Rauch, Steven D

2006-05-01

In this retrospective study, we tested the hypothesis that vestibular evoked myogenic potential (VEMP) thresholds are more often elevated or absent in patients with Ménière's disease experiencing Tumarkin drop attacks than in other patients with Ménière's disease. Subjects included normal subjects (n = 14) and patients with unilateral Ménière's disease by AAO-HNS (1995) diagnostic criteria with (n = 12) and without (n = 82) Tumarkin drop attacks at a large specialty hospital otology service. VEMP threshold testing was conducted using 250, 500, and 1,000 Hz tone burst stimuli. VEMP responses were present in at all frequencies in both ears of all normal subjects. In unaffected ears of patients with unilateral Ménière's disease, VEMPs were undetectable in 13% of measurements attempted. This number rose to 18% in affected ears of patients with unilateral Ménière's disease and to 41% in Meniere ears with Tumarkin drop attacks. Frequency tuning of the VEMP response in normal subjects showed lowest thresholds at 500 Hz. In Meniere ears, the tuning was altered such that the 500-Hz thresholds were higher than the 1,000-Hz thresholds. There was a gradient of threshold elevation and altered tuning that corresponded to the gradient of worsening disease. Our findings support the hypothesis that Tumarkin drop attacks arise from advanced disease involving the saccule and that VEMP may be a clinically valuable metric of disease severity or progression in patients with Ménière's disease.

Interactive wiimote gaze stabilization exercise training system for patients with vestibular hypofunction

PubMed Central

2012-01-01

Background Peripheral vestibular hypofunction is a major cause of dizziness. When complicated with postural imbalance, this condition can lead to an increased incidence of falls. In traditional clinical practice, gaze stabilization exercise is commonly used to rehabilitate patients. In this study, we established a computer-aided vestibular rehabilitation system by coupling infrared LEDs to an infrared receiver. This system enabled the subjects’ head-turning actions to be quantified, and the training was performed using vestibular exercise combined with computer games and interactive video games that simulate daily life activities. Methods Three unilateral and one bilateral vestibular hypofunction patients volunteered to participate in this study. The participants received 30 minutes of computer-aided vestibular rehabilitation training 2 days per week for 6 weeks. Pre-training and post-training assessments were completed, and a follow-up assessment was completed 1 month after the end of the training period. Results After 6 weeks of training, significant improvements in balance and dynamic visual acuity (DVA) were observed in the four participants. Self-reports of dizziness, anxiety and depressed mood all decreased significantly. Significant improvements in self-confidence and physical performance were also observed. The effectiveness of this training was maintained for at least 1 month after the end of the training period. Conclusion Real-time monitoring of training performance can be achieved using this rehabilitation platform. Patients demonstrated a reduction in dizziness symptoms after 6 weeks of training with this short-term interactive game approach. This treatment paradigm also improved the patients’ balance function. This system could provide a convenient, safe and affordable treatment option for clinical practitioners. PMID:23043886

Interactive wiimote gaze stabilization exercise training system for patients with vestibular hypofunction.

PubMed

Chen, Po-Yin; Hsieh, Wan-Ling; Wei, Shun-Hwa; Kao, Chung-Lan

2012-10-09

Peripheral vestibular hypofunction is a major cause of dizziness. When complicated with postural imbalance, this condition can lead to an increased incidence of falls. In traditional clinical practice, gaze stabilization exercise is commonly used to rehabilitate patients. In this study, we established a computer-aided vestibular rehabilitation system by coupling infrared LEDs to an infrared receiver. This system enabled the subjects' head-turning actions to be quantified, and the training was performed using vestibular exercise combined with computer games and interactive video games that simulate daily life activities. Three unilateral and one bilateral vestibular hypofunction patients volunteered to participate in this study. The participants received 30 minutes of computer-aided vestibular rehabilitation training 2 days per week for 6 weeks. Pre-training and post-training assessments were completed, and a follow-up assessment was completed 1 month after the end of the training period. After 6 weeks of training, significant improvements in balance and dynamic visual acuity (DVA) were observed in the four participants. Self-reports of dizziness, anxiety and depressed mood all decreased significantly. Significant improvements in self-confidence and physical performance were also observed. The effectiveness of this training was maintained for at least 1 month after the end of the training period. Real-time monitoring of training performance can be achieved using this rehabilitation platform. Patients demonstrated a reduction in dizziness symptoms after 6 weeks of training with this short-term interactive game approach. This treatment paradigm also improved the patients' balance function. This system could provide a convenient, safe and affordable treatment option for clinical practitioners.

Neural correlates of motor learning in the vestibulo-ocular reflex: dynamic regulation of multimodal integration in the macaque vestibular system

PubMed Central

Sadeghi, Soroush G.; Minor, Lloyd B.; Cullen, Kathleen E.

2010-01-01

Motor learning is required for the reacquisition of skills that have been compromised as a result of brain lesion or disease, as well as for the acquisition of new skills. Behaviors with well-characterized anatomy and physiology are required to yield significant insight into changes that occur in the brain during motor learning. The vestibulo-ocular-reflex (VOR) is well suited to establish connections between neurons, neural circuits, and motor performance during learning. Here we examined the linkage between neuronal and behavioural VOR responses in alert behaving monkeys (macaca mulatta) during the impressive recovery that occurs after unilateral vestibular loss. We show, for the first time, that motor learning is characterized by the dynamic reweighting of inputs from different modalities (i.e., vestibular versus extra-vestibular) at the level of the single neurons which constitute the first central stage of vestibular processing. Specifically, two types of information, which did not influence neuronal responses prior to the lesion, had an important role during compensation. First, unmasked neck proprioceptive inputs played a critical role in the early stages of this process demonstrated by faster and more substantial recovery of vestibular responses in proprioceptive sensitive neurons. Second, neuronal and VOR responses were significantly enhanced during active relative to passive head motion later in the compensation process (>3 weeks). Taken together, our findings provide evidence linking the dynamic regulation of multimodal integration at the level of single neurons and behavioural recovery, suggesting a role for homeostatic mechanisms in VOR motor learning. PMID:20668199

[Immediate recurrent laryngeal nerve reconstruction in the treatment of thyroid cancer invading the recurrent laryngeal nerve].

PubMed

Feng, Yun; Yang, Dazhang; Liu, Dandan; Chen, Jian; Bi, Qingling; Luo, Keqiang

2014-08-01

To explore the application of immediate recurrent laryngeal nerve reconstruction in the treatment of thyroid cancer invading the recurrent laryngeal nerve. Ten patients with thyroid cancer invading unilateral recurrent laryngeal nerve underwent radical surgery and immediate recurrent laryngeal nerve reconstruction. The reconstructive surgical approach included recurrent laryngeal nerve decompression surgery, end-to-end anastomosis of the recurrent laryngeal nerve, anastomosis of ansa cervicalis nerve to the recurrent laryngeal nerve, and nerve-muscle pedicle (NMP) technique. Among the ten patients, one underwent nerve decompression, one underwent end-to-end anastomosis of the recurrent laryngeal nerve, seven had anastomosis of ansa cervicalis to recurrent laryngeal nerve, and one case had anastomosis of ansa cervicalis to recurrent laryngeal nerve combined with nerve-muscle pedicle (NMP) technique. The effect of surgery was evaluated by videolaryngoscopy, maximum phonation time (MPT), phonation efficiency index (PEI) and voice assessment. T-test was used in the statistical analysis. All of the 10 patients had no complications including tumor recurrence and hypoparathyroidism after the surgery. Their hoarseness symptoms were improved, and the patients returned to normal or near-normal voice. Postoperative videolaryngoscopy showed that paralyzed vocal cord returned to normal muscle tone and volume, and the vocal cord vibration and mucosal wave were symmetric and the patients got good glottal closure. The pre- and post-operative maximum phone times of the patients were (4.52 ± 0.89) s and (11.91 ± 1.87) s, respectively (P < 0.01). The pre- and post-operative phonation efficiency indices were (1.37 ± 0.43) s/L and (4.02 ± 1.33) s/L, respectively (P < 0.05). In patients with thyroid cancer invading unilateral recurrent laryngeal nerve, immediate recurrent laryngeal nerve reconstruction following radical surgery of thyroid cancer can effectively achieve recovery in phonation function and improve the quality of life of the patients.

Children with optic nerve hypoplasia face a high risk of neurodevelopmental disorders.

PubMed

Dahl, Sara; Wickström, Ronny; Ek, Ulla; Teär Fahnehjelm, Kristina

2018-03-01

Optic nerve hypoplasia (ONH) is a congenital ocular malformation that has been associated with neurodevelopmental disorders, but the prevalence in unilateral disease and less severe visual impairment is unknown. We studied intellectual disability and autism spectrum disorders (ASDs) in patients with ONH. This was a population-based cross-sectional cohort study of 65 patients (33 female) with ONH below 20 years of age, living in Stockholm in December 2009, with data analysed in January 2016. Of these 35 were bilateral and 30 were unilateral. Neurodevelopmental disorders were diagnosed or confirmed by neurological assessments, the Five to Fifteen parent questionnaire and reviewing previous neuropsychological investigations or conducting neuropsychological tests. Bilateral ONH patients had lower mean full scale intelligence quotient scores than unilateral patients (84.4 and 99.4, respectively, p = 0.049). We assessed intellectual disability in 55 eligible patients, and it was more common in patients with bilateral ONH (18 of 32, 56%) than unilateral ONH (two of 23, 9%, p < 0.001). ASDs were diagnosed in seven of 42 (17%) patients. Children with bilateral ONH had a high risk of neurodevelopmental disorders, especially intellectual disability. The risk was lower in unilateral ONH, but the levels of neurodevelopmental disorders warrant screening of both groups. ©2017 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Stereotactic radiosurgery for vestibular schwannoma: International Stereotactic Radiosurgery Society (ISRS) Practice Guideline.

PubMed

Tsao, May N; Sahgal, Arjun; Xu, Wei; De Salles, Antonio; Hayashi, Motohiro; Levivier, Marc; Ma, Lijun; Martinez, Roberto; Régis, Jean; Ryu, Sam; Slotman, Ben J; Paddick, Ian

2017-01-01

The aim of this systematic review was to develop International Stereotactic Radiosurgery Society (ISRS) consensus guideline statements for vestibular schwannoma. A systematic review of the literature was performed up to April 2015. A total of 55 full-text articles were included in the analysis. All studies were retrospective, except for 2 prospective quality of life studies. Five-year tumour control rates with Gamma Knife radiosurgery (RS), single fraction linac RS, or fractionated (either hypofractionated or conventional fractionation) stereotactic radiation therapy (FSRT) were similar at 81-100%. The single fraction RS series (linac or Gamma Knife) with tumour marginal doses between 12 and 14 Gy revealed 5-year tumour control rates of 90-99%, hearing preservation rates of 41-79%, facial nerve preservation rates of 95-100% and trigeminal preservation rates of 79-99%.There were 6 non-randomized studies comparing single fraction RS versus FSRT. There was no statistically significant difference in tumour control; HR=1.66 (95% CI 0.81, 3.42), p =0.17, facial nerve function; HR = 0.67 (95% CI 0.30, 1.49), p =0.33, trigeminal nerve function; HR = 0.80 (95% CI 0.41, 1.56), p =0.51, and hearing preservation; HR = 1.10 (95% CI 0.72, 1.68), p =0.65 comparing single fraction RS with FSRT.Nine quality of life reports yielded conflicting results as to which modality (surgery, observation, or radiation) was associated with better quality of life outcomes. There are no randomized trials to help guide management of patients with vestibular schwannoma. Within the limitations of the retrospective series, a number of consensus statements were made.

Stereotactic radiosurgery for vestibular schwannoma: International Stereotactic Radiosurgery Society (ISRS) Practice Guideline

PubMed Central

Sahgal, Arjun; Xu, Wei; De Salles, Antonio; Hayashi, Motohiro; Levivier, Marc; Ma, Lijun; Martinez, Roberto; Régis, Jean; Ryu, Sam; Slotman, Ben J.; Paddick, Ian

2017-01-01

Objectives The aim of this systematic review was to develop International Stereotactic Radiosurgery Society (ISRS) consensus guideline statements for vestibular schwannoma. Methods A systematic review of the literature was performed up to April 2015. Results A total of 55 full-text articles were included in the analysis. All studies were retrospective, except for 2 prospective quality of life studies. Five-year tumour control rates with Gamma Knife radiosurgery (RS), single fraction linac RS, or fractionated (either hypofractionated or conventional fractionation) stereotactic radiation therapy (FSRT) were similar at 81-100%. The single fraction RS series (linac or Gamma Knife) with tumour marginal doses between 12 and 14 Gy revealed 5-year tumour control rates of 90-99%, hearing preservation rates of 41-79%, facial nerve preservation rates of 95-100% and trigeminal preservation rates of 79-99%. There were 6 non-randomized studies comparing single fraction RS versus FSRT. There was no statistically significant difference in tumour control; HR=1.66 (95% CI 0.81, 3.42), p =0.17, facial nerve function; HR = 0.67 (95% CI 0.30, 1.49), p =0.33, trigeminal nerve function; HR = 0.80 (95% CI 0.41, 1.56), p =0.51, and hearing preservation; HR = 1.10 (95% CI 0.72, 1.68), p =0.65 comparing single fraction RS with FSRT. Nine quality of life reports yielded conflicting results as to which modality (surgery, observation, or radiation) was associated with better quality of life outcomes. Conclusions There are no randomized trials to help guide management of patients with vestibular schwannoma. Within the limitations of the retrospective series, a number of consensus statements were made. PMID:29296459

Progression of vestibular schawnnoma after GammaKnife radiosurgery: A challenge for microsurgical resection.

PubMed

Aboukaïs, Rabih; Bonne, Nicolas-Xavier; Touzet, Gustavo; Vincent, Christophe; Reyns, Nicolas; Lejeune, Jean-Paul

2018-05-01

We aimed to evaluate the outcome of patients who underwent salvage microsurgery for vestibular schwannoma (VS) that failed primary Gammaknife radiosurgery (GKS). Among the 1098 patients who received GKS for the treatment of VS in our center between January 2004 and December 2012, the follow-up was organized in our institution for 290 patients who lived in our recruitment area. Tumor progression was noted in 23 patients. A salvage microsurgical resection was performed in 11 patients, who were included in our study. Grading of facial function was done according to the House & Brackman scale. The mean age at diagnosis was 50.2 years (19-68 years) and the mean follow-up was 9.4 years (4-13 years). The mean dose was 11.8 Gy (11-12 Gy) and the mean volume was 922 mm3 (208-2500 mm3). The mean period between GKS and diagnosis of tumor progression was 32 months (18-72 months). Concerning salvage microsurgery, complete resection was obtained in 8 patients. Small residual tumor on the facial nerve was deliberately left in 3 patients and no tumor progression was noted with a mean follow-up of 26 months. At last follow-up, facial nerve function was grade 1 in 4 patients, grade 2 in 3 patients, grade 3 in 1 patient and grade 4 in 3 patients. Salvage surgery of recurrent vestibular schwannoma after failed initial GKS remains a good treatment. However, facial nerve preservation is more challenging in this case and small tumor remnant could be sometimes deliberately left. Copyright © 2018 Elsevier B.V. All rights reserved.

Treatment of traumatic infra orbital nerve paresthesia

PubMed Central

Lone, Parveen Akhter; Singh, R. K.; Pal, U. S.

2012-01-01

This study was done to find out the role of topiramate therapy in infraorbital nerve paresthesia after miniplate fixation in zygomatic complxex fractures. A total 2 cases of unilateral zygomatic complex fracture, 2-3 weeks old with infra orbital nerve paresthesia were slected. Open reduction and plating was done in frontozygomaticregion. Antiepileptic drug tab topiramate was given in therapeutic doses and dose was increased slowly until functional recovery was noticed. PMID:23833503

Convergence of linear acceleration and yaw rotation signals on non-eye movement neurons in the vestibular nucleus of macaques.

PubMed

Newlands, Shawn D; Abbatematteo, Ben; Wei, Min; Carney, Laurel H; Luan, Hongge

2018-01-01

Roughly half of all vestibular nucleus neurons without eye movement sensitivity respond to both angular rotation and linear acceleration. Linear acceleration signals arise from otolith organs, and rotation signals arise from semicircular canals. In the vestibular nerve, these signals are carried by different afferents. Vestibular nucleus neurons represent the first point of convergence for these distinct sensory signals. This study systematically evaluated how rotational and translational signals interact in single neurons in the vestibular nuclei: multisensory integration at the first opportunity for convergence between these two independent vestibular sensory signals. Single-unit recordings were made from the vestibular nuclei of awake macaques during yaw rotation, translation in the horizontal plane, and combinations of rotation and translation at different frequencies. The overall response magnitude of the combined translation and rotation was generally less than the sum of the magnitudes in responses to the stimuli applied independently. However, we found that under conditions in which the peaks of the rotational and translational responses were coincident these signals were approximately additive. With presentation of rotation and translation at different frequencies, rotation was attenuated more than translation, regardless of which was at a higher frequency. These data suggest a nonlinear interaction between these two sensory modalities in the vestibular nuclei, in which coincident peak responses are proportionally stronger than other, off-peak interactions. These results are similar to those reported for other forms of multisensory integration, such as audio-visual integration in the superior colliculus. NEW & NOTEWORTHY This is the first study to systematically explore the interaction of rotational and translational signals in the vestibular nuclei through independent manipulation. The results of this study demonstrate nonlinear integration leading to maximum response amplitude when the timing and direction of peak rotational and translational responses are coincident.

Quality of life in patients with unilateral vestibular schwannoma on wait and see - strategy.

PubMed

Klersy, P C; Arlt, F; Hofer, M; Meixensberger, J

2018-01-01

A 'wait and see' strategy is an option when managing patients with small vestibular schwannomas (VS). A risk of growth and worsening of hearing may influence a patient's daily quality of life (QOL). Therefore, the present study focused on QOL parameters in patients who are on a 'wait and see' strategy following magnetic resonance imaging (MRI)-based diagnosis of small unilateral VS. Sixty-five patients (mean age 64.4 years; male:female, 32:33) who suffered from a small unilateral VS (9.34 mm, range 1.5-23 mm) between 2013 and 2016 were included in a prospective single center study. During follow-up, in addition to clinical and neurological examinations and MRI imaging, all patients answered the Short Form 36 questionnaire once to characterize QOL. Additionally, the severity of tinnitus was determined by the Mini-TQ-12 from Hiller and Goebel. It was found during follow-up that there was no lowering of QOL in patients with small VS who were on 'wait and see' strategy compared with Germany's general population and no tumor growth was detected in 53 patients (81.5%). Patients with a tumor diameter larger than 10 mm did not suffer from stronger tinnitus, vertigo or unsteadiness than the group with an average tumor size, which is smaller than 10 mm. Sixty-two patients (95.4%) showed ipsilateral hearing loss and three of these reported deafness (4.6%). Severe vertigo or tinnitus is connected with lower levels of mental component scale and physical component scale. These findings reduced the QOL (p = 0.05). In our series, QOL is not influenced in patients with unilateral untreated small VS in comparison to Germany's general population. This is helpful information when advising patients during follow-up and finding out the optimal timing of individual treatment.

Tumor Biology of Vestibular Schwannoma: A Review of Experimental Data on the Determinants of Tumor Genesis and Growth Characteristics.

PubMed

de Vries, Maurits; van der Mey, Andel G L; Hogendoorn, Pancras C W

2015-08-01

Provide an overview of the literature on vestibular schwannoma biology with special attention to tumor behavior and targeted therapy. Vestibular schwannomas are benign tumors originating from the eighth cranial nerve and arise due to inactivation of the NF2 gene and its product merlin. Unraveling the biology of these tumors helps to clarify their growth pattern and is essential in identifying therapeutic targets. PubMed search for English-language articles on vestibular schwannoma biology from 1994 to 2014. Activation of merlin and its role in cell signaling seem as key aspects of vestibular schwannoma biology. Merlin is regulated by proteins such as CD44, Rac, and myosin phosphatase-targeting subunit 1. The tumor-suppressive functions of merlin are related to receptor tyrosine kinases, such as the platelet-derived growth factor receptor and vascular endothelial growth factor receptor. Merlin mediates the Hippo pathway and acts within the nucleus by binding E3 ubiquiting ligase CRL4. Angiogenesis is an important mechanism responsible for the progression of these tumors and is affected by processes such as hypoxia and inflammation. Inhibiting angiogenesis by targeting vascular endothelial growth factor receptor seems to be the most successful pharmacologic strategy, but additional therapeutic options are emerging. Over the years, the knowledge on vestibular schwannoma biology has significantly increased. Future research should focus on identifying new therapeutic targets by investigating vestibular schwannoma (epi)genetics, merlin function, and tumor behavior. Besides identifying novel targets, testing new combinations of existing treatment strategies can further improve vestibular schwannoma therapy.

[Enlarged vestibular aqueduct syndrome. A review of 55 paediatric patients].

PubMed

Santos, Saturnino; Sgambatti, Luciano; Bueno, Antonio; Albi, Gustavo; Suárez, Alicia; Domínguez, Maria Jesús

2010-01-01

Enlarged vestibular aqueduct (EVA) is the commonest congenital anomaly found with imaging techniques in paediatric sensorineural hearing loss (SNHL). Our aim was to describe clinical and audiological findings in paediatric hearing loss associated to EVA. Retrospective review of 55 children with imaging-technique EVA findings from 2000 to 2009. Subjective and/or objective audiological tests were analysed and audiological findings related to clinical features were described. Thirty-seven patients (67.27%) showed bilateral EVA and 18 (32.72%) were unilateral. Hearing loss was bilateral in 46 (83.63%) patients and unilateral in 9 (16.36%). Mean age at diagnosis was 3.78 years. Fifty-three (96.36%) children showed SNHL (28 bilateral and profound), while 2 (3.63%) patients had mixed hearing loss. There were 3 cases of hearing loss progression, 2 fluctuations, 2 of them were asymmetric and 2 patients suffered from vestibular symptoms. Concomitant image findings were 6 cochlear hypoplasia, 2 enlarged internal auditory canals, 1 enlarged vestibule and 1 hypoplastic lateral semicircular canal. Six clinical syndromes were found (2 cases of Down's, and 1 each of Jacobsen, Pendred, Waardenburg and branchio-oto-renal). One child was positive for GJB2 mutation. Familial hearing loss was demonstrated on 12 (21.8%) cases. The clinical picture of hearing loss associated to EVA is characterised by great variability. It should be included in the differential diagnosis of unexplained mixed hearing loss. Familial and syndromic findings have to be taken into consideration in the diagnostic evaluations of such patients. Knowledge about the natural history of this illness is needed so as to give parents prognostic information. Copyright © 2010 Elsevier España, S.L. All rights reserved.

Leg orientation as a clinical sign for pusher syndrome

PubMed Central

Johannsen, Leif; Broetz, Doris; Karnath, Hans-Otto

2006-01-01

Background Effective control of (upright) body posture requires a proper representation of body orientation. Stroke patients with pusher syndrome were shown to suffer from severely disturbed perception of own body orientation. They experience their body as oriented 'upright' when actually tilted by nearly 20° to the ipsilesional side. Thus, it can be expected that postural control mechanisms are impaired accordingly in these patients. Our aim was to investigate pusher patients' spontaneous postural responses of the non-paretic leg and of the head during passive body tilt. Methods A sideways tilting motion was applied to the trunk of the subject in the roll plane. Stroke patients with pusher syndrome were compared to stroke patients not showing pushing behaviour, patients with acute unilateral vestibular loss, and non brain damaged subjects. Results Compared to all groups without pushing behaviour, the non-paretic leg of the pusher patients showed a constant ipsiversive tilt across the whole tilt range for an amount which was observed in the non-pusher subjects when they were tilted for about 15° into the ipsiversive direction. Conclusion The observation that patients with acute unilateral vestibular loss showed no alterations of leg posture indicates that disturbed vestibular afferences alone are not responsible for the disordered leg responses seen in pusher patients. Our results may suggest that in pusher patients a representation of body orientation is disturbed that drives both conscious perception of body orientation and spontaneous postural adjustment of the non-paretic leg in the roll plane. The investigation of the pusher patients' leg-to-trunk orientation thus could serve as an additional bedside tool to detect pusher syndrome in acute stroke patients. PMID:16928280

Recovery of Vestibulo-Ocular Reflex Symmetry After an Acute Unilateral Peripheral Vestibular Deficit: Time Course and Correlation With Canal Paresis.

PubMed

Allum, John H J; Cleworth, T; Honegger, Flurin

2016-07-01

We investigated how response asymmetries and deficit side response amplitudes for head accelerations used clinically to test the vestibular ocular reflex (VOR) are correlated with caloric canal paresis (CP) values. 30 patients were examined at onset of an acute unilateral peripheral vestibular deficit (aUPVD) and 3, 6, and 13 weeks later with three different VOR tests: caloric, rotating chair (ROT), and video head impulse tests (vHIT). Response changes over time were fitted with an exponential decay model and compared with using linear regression analysis. Recovery times (to within 10% of steady state) were similar for vHIT-asymmetry and CP (>10 weeks) but shorter for ROT asymmetry (<4 weeks). Regressions with CP were similar (vHIT asymmetry, R = 0.68, ROT, R = 0.62). Responses to the deficit side were also equally well correlated with CP values (R = 0.71). Specificity for vHIT and 20 degrees/s ROT deficit side responses was 100% in comparison to CP values, sensitivity was 74% for vHIT, 75% for ROT. A decrease in normal side responses occurred for ROT but not for vHIT at 3 weeks. Normal side responses were weekly correlated with CP for ROT (R = 0.49) but not for vHIT (R = 0.17). These results indicate that vHIT deficit side VOR gains are slightly better correlated with CP values than ROT, probably because of similar recovery time courses of vHIT and caloric responses and the lack of normal side vHIT changes. However, specificity and sensitivity is the same for vHIT and ROT tests.

Spine Topographical Distribution of Skin α-Synuclein Deposits in Idiopathic Parkinson Disease.

PubMed

Donadio, Vincenzo; Incensi, Alex; Rizzo, Giovanni; Scaglione, Cesa; Capellari, Sabina; Fileccia, Enrico; Avoni, Patrizia; Liguori, Rocco

2017-05-01

Phosphorylated α-synuclein (p-syn) in skin nerves mainly in the proximal sites is a promising neurodegenerative biomarker for idiopathic Parkinson disease (IPD). However, the p-syn spine distribution particularly in patients with unilateral motor dysfunctions remains undefined. This study aimed to investigate in IPD p-syn differences between left and right cervical spine sites in patients with prevalent unilateral motor symptoms, and cervical and thoracic spine sites in patients with bilateral motor symptoms. We enrolled 28 IPD patients fulfilling clinical diagnostic criteria associated with abnormal nigro-striatal DatScan and cardiac MIBG: 15 with prevalently unilateral motor symptoms demonstrated by DatScan; 13 with bilateral motor symptoms and DatScan abnormalities. Patients underwent skin biopsy searching for intraneural p-syn deposits: skin samples were taken from C7 paravertebral left and right sites in unilateral patients and from cervical (C7) and thoracic (Th12) paravertebral spine regions in bilateral patients. Unilateral patients displayed 20% of abnormal p-syn deposits in the affected motor site, 60% in both sites and 20% only in the non-affected site. P-syn was found in all patients in C7 but in only 62% of patients in Th12. Our data showed that cervical p-syn deposits displayed a uniform distribution between both sides not following the motor dysfunction in unilateral patients, and skin nerve p-syn deposits demonstrated a spine gradient with the cervical site expressing the highest positivity. © 2017 American Association of Neuropathologists, Inc. All rights reserved.

Occlusion of carotid artery and hypergravity loading of animals caused similar effects on L-[14C]glutamate uptake in rat brain nerve terminals

NASA Astrophysics Data System (ADS)

Borisova, Tatiana; Sivko, Roman; Krisanova, Natalia

Changes in sodium-dependent L-[14C]glutamate uptake in rat brain nerve terminals was com-paratively analysed after hypergravity loading of animals (centrifugation of rats in special con-tainers at 10 G for 1 hour) and unilateral occlusion of carotid artery (20 min). The initial velocity of L-[14C]glutamate uptake was decreased from 2.5 ± 0.2 nmol x min-1 x mg-1 of proteins to 2.05 ± 0.1 nmol x min-1 x mg-1 of proteins after hypergravity and after occlusion -up to 2.25 ± 0.1 nmol x min-1 x mg-1 of proteins. Recently, we have shown that a decrease in L-[14C]glutamate uptake was at least partially caused by the redaction in the membrane potential of nerve terminals and the proton gradient of synaptic vesicles. These parameters were analysed after unilateral occlusion of carotid artery, where one brain hemisphere was used as a control, whereas the second one as subjected to ischemic/hypoxic conditions. Similarly with hypergravity, we revealed a decrease in the membrane potential of nerve terminals by ˜ 10 % and a reduction of the proton gradient of synaptic vesicles by ˜ 5 % after occlusion of carotid artery. Thus, a decrease in the activity of glutamate transporters after hypergrav-ity and unilateral occlusion of carotid artery was at least partially caused by changes in the membrane potential of nerve terminals and the proton gradient of synaptic vesicles. This fact may be considered in support of the suggestion that ischemia/hypoxia was a main unspecific stressor, which caused the alterations in glutamatergic neurotransmission under conditions of hypergravity.

Hemicrania Continua: Beneficial Effect of Non-Invasive Vagus Nerve Stimulation in a Patient With a Contraindication for Indomethacin.

PubMed

Eren, Ozan; Straube, Andreas; Schöberl, Florian; Schankin, Christoph

2017-02-01

Hemicrania continua (HC) is a primary chronic headache disorder, characterized by a continuous and strictly unilateral headache, with possible cranial autonomic symptoms during episodes of pain exacerbation. The unilateral headache generally responds well to indomethacin; however, continuous indomethacin intake is often not tolerated due to severe adverse effects, like hypertension, gastrointestinal discomfort (especially if combined with aspirin), slightly increased risk of vascular events, and bronchial spasms. Therefore, alternative treatment options are desperately needed. Non-invasive vagus nerve stimulation (nVNS) has been shown to be effective in patients with cluster headache, another trigeminal autonomic cephalalgia (TAC), with cranial parasympathetic autonomic activation during the attacks. © 2016 American Headache Society.

Studies on the cellular localization of spinal cord substance P receptors.

PubMed

Helke, C J; Charlton, C G; Wiley, R G

1986-10-01

Substance P-immunoreactivity and specific substance P binding sites are present in the spinal cord. Receptor autoradiography showed the discrete localization of substance P binding sites in both sensory and motor regions of the spinal cord and functional studies suggested an important role for substance P receptor activation in autonomic outflow, nociception, respiration and somatic motor function. In the current studies, we investigated the cellular localization of substance P binding sites in rat spinal cord using light microscopic autoradiography combined with several lesioning techniques. Unilateral injections of the suicide transport agent, ricin, into the superior cervical ganglion reduced substance P binding and cholinesterase-stained preganglionic sympathetic neurons in the intermediolateral cell column. However, unilateral electrolytic lesions of ventral medullary substance P neurons which project to the intermediolateral cell column did not alter the density of substance P binding in the intermediolateral cell column. Likewise, 6-hydroxydopamine and 5,7-dihydroxytryptamine, which destroy noradrenergic and serotonergic nerve terminals, did not reduce the substance P binding in the intermediolateral cell column. It appears, therefore, that the substance P binding sites are located postsynaptically on preganglionic sympathetic neurons rather than presynaptically on substance P-immunoreactive processes (i.e. as autoreceptors) or on monoamine nerve terminals. Unilateral injections of ricin into the phrenic nerve resulted in the unilateral destruction of phrenic motor neurons in the cervical spinal cord and caused a marked reduction in the substance P binding in the nucleus. Likewise, sciatic nerve injections of ricin caused a loss of associated motor neurons in the lateral portion of the ventral horn of the lumbar spinal cord and a reduction in the substance P binding. Sciatic nerve injections of ricin also destroyed afferent nerves of the associated dorsal root ganglia and increased the density of substance P binding in the dorsal horn. Capsaicin, which destroys small diameter primary sensory neurons, similarly increased the substance P binding in the dorsal horn. These studies show that the cellular localization of substance P binding sites can be determined by analysis of changes in substance P binding to discrete regions of spinal cord after selective lesions of specific groups of neurons. The data show the presence of substance P binding sites on preganglionic sympathetic neurons in the intermediolateral cell column and on somatic motor neurons in the ventral horn, including the phrenic motor nucleus.(ABSTRACT TRUNCATED AT 400 WORDS)

Interaction of the vestibular system and baroreflexes on sympathetic nerve activity in humans

NASA Technical Reports Server (NTRS)

Ray, C. A.

2000-01-01

Muscle sympathetic nerve activity (MSNA) is altered by vestibular otolith stimulation. This study examined interactive effects of the vestibular system and baroreflexes on MSNA in humans. In study 1, MSNA was measured during 4 min of lower body negative pressure (LBNP) at either -10 or -30 mmHg with subjects in prone posture. During the 3rd min of LBNP, subjects lowered their head over the end of a table (head-down rotation, HDR) to engage the otolith organs. The head was returned to baseline upright position during the 4th min. LBNP increased MSNA above baseline during both trials with greater increases during the -30-mmHg trial. HDR increased MSNA further during the 3rd min of LBNP at -10 and -30 mmHg (Delta32% and Delta34%, respectively; P < 0.01). MSNA returned to pre-HDR levels during the 4th min of LBNP when the head was returned upright. In study 2, MSNA was measured during HDR, LBNP, and simultaneously performed HDR and LBNP. The sum of MSNA responses during individual HDR and LBNP trials was not significantly different from that observed during HDR and LBNP performed together (Delta131 +/- 28 vs. Delta118 +/- 47 units and Delta340 +/- 77 vs. Delta380 +/- 90 units for the -10 and -30 trials, respectively). These results demonstrate that vestibular otolith stimulation can increase MSNA during unloading of the cardiopulmonary and arterial baroreflexes. Also, the interaction between the vestibulosympathetic reflex and baroreflexes is additive in humans. These studies indicate that the vestibulosympathetic reflex may help defend against orthostatic challenges in humans by increasing sympathetic outflow.

Phrenic nerve decompression for the management of unilateral diaphragmatic paralysis – preoperative evaluation and operative technique

PubMed Central

Hoshide, Reid; Brown, Justin

2017-01-01

Background: Unilateral diaphragmatic paralysis (UDP) can be a very disabling, typically causing shortness of breath and reduced exercise tolerance. We present a case of a surgical decompression of the phrenic nerve of a patient who presented with UDP, which occurred following cervical spine surgery. Methods: The workup for the etiology of UDP demonstrated paradoxical movement on “sniff test” and notably impaired pulmonary function tests. Seven months following the onset of the UDP, he underwent a surgical decompression of the phrenic nerve at the level of the anterior scalene. Results: He noted rapid symptomatic improvement following surgery and reversal of the above noted objective findings was documented. At his 4-year follow-up, he had complete resolution of his clinical symptoms. Repeated physiologic testing of his respiratory function had shown a complete reversal of his UDP. Conclusions: Anatomical compression of the phrenic nerve by redundant neck vasculature should be considered in the differential diagnosis of UDP. Here we demonstrated the techniques in workup and surgical management, with both subjective and objective evidence of success. PMID:29184705

Phrenic nerve decompression for the management of unilateral diaphragmatic paralysis - preoperative evaluation and operative technique.

PubMed

Hoshide, Reid; Brown, Justin

2017-01-01

Unilateral diaphragmatic paralysis (UDP) can be a very disabling, typically causing shortness of breath and reduced exercise tolerance. We present a case of a surgical decompression of the phrenic nerve of a patient who presented with UDP, which occurred following cervical spine surgery. The workup for the etiology of UDP demonstrated paradoxical movement on "sniff test" and notably impaired pulmonary function tests. Seven months following the onset of the UDP, he underwent a surgical decompression of the phrenic nerve at the level of the anterior scalene. He noted rapid symptomatic improvement following surgery and reversal of the above noted objective findings was documented. At his 4-year follow-up, he had complete resolution of his clinical symptoms. Repeated physiologic testing of his respiratory function had shown a complete reversal of his UDP. Anatomical compression of the phrenic nerve by redundant neck vasculature should be considered in the differential diagnosis of UDP. Here we demonstrated the techniques in workup and surgical management, with both subjective and objective evidence of success.

Cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS) with chronic cough and preserved muscle stretch reflexes: evidence for selective sparing of afferent Ia fibres.

PubMed

Infante, Jon; García, Antonio; Serrano-Cárdenas, Karla M; González-Aguado, Rocío; Gazulla, José; de Lucas, Enrique M; Berciano, José

2018-06-01

The aim of this study was to describe five patients with cerebellar ataxia, neuropathy and vestibular areflexia syndrome (CANVAS) with chronic cough and preserved limb muscle stretch reflexes. All five patients were in the seventh decade of age, their gait imbalance having been initiated in the fifth decade. In four patients cough antedated gait imbalance between 15 and 29 years; cough was spasmodic and triggered by variable factors. Established clinical picture included severe hypopallesthesia predominating in the lower limbs with postural imbalance, and variable degree of cerebellar axial and appendicular ataxia, dysarthria and horizontal gaze-evoked nystagmus. Upper- and lower-limb tendon jerks were preserved, whereas jaw jerk was absent. Vestibular function testing showed bilateral impairment of the vestibulo-ocular reflex. Nerve conduction studies demonstrated normal motor conduction parameters and absence or severe attenuation of sensory nerve action potentials. Somatosensory evoked potentials were absent or severely attenuated. Biceps and femoral T-reflex recordings were normal, while masseter reflex was absent or attenuated. Sympathetic skin responses were normal. Cranial MRI showed vermian and hemispheric cerebellar atrophy predominating in lobules VI, VII and VIIa. We conclude that spasmodic cough may be an integral part of the clinical picture in CANVAS, antedating the appearance of imbalance in several decades and that sparing of muscle spindle afferents (Ia fibres) is probably the pathophysiological basis of normoreflexia.

Posterior insular cortex – a site of vestibular–somatosensory interaction?

PubMed Central

Baier, Bernhard; zu Eulenburg, Peter; Best, Christoph; Geber, Christian; Müller-Forell, Wibke; Birklein, Frank; Dieterich, Marianne

2013-01-01

Background In previous imaging studies the insular cortex (IC) has been identified as an essential part of the processing of a wide spectrum of perception and sensorimotor integration. Yet, there are no systematic lesion studies in a sufficient number of patients examining whether processing of vestibular and the interaction of somatosensory and vestibular signals take place in the IC. Methods We investigated acute stroke patients with lesions affecting the IC in order to fill this gap. In detail, we explored signs of a vestibular tone imbalance such as the deviation of the subjective visual vertical (SVV). We applied voxel-lesion behaviour mapping analysis in 27 patients with acute unilateral stroke. Results Our data demonstrate that patients with lesions of the posterior IC have an abnormal tilt of SVV. Furthermore, re-analysing data of 20 patients from a previous study, we found a positive correlation between thermal perception contralateral to the stroke and the severity of the SVV tilt. Conclusions We conclude that the IC is a sensory brain region where different modalities might interact. PMID:24392273

Motion sickness is linked to nystagmus-related trigeminal brain stem input: a new hypothesis.

PubMed

Gupta, Vinod Kumar

2005-01-01

Motion sickness is a common and distressing but poorly understood syndrome associated with nausea/vomiting and autonomic nervous system accompaniments that develops in the air or space as well as on sea or land. A bidirectional aetiologic link prevails between migraine and motion-sickness. Motion sickness provokes jerk nystagmus induced by both optokinetic and vestibular stimulation. Fixation of gaze or closure of eyes generally prevents motion sickness while vestibular otolithic function is eliminated in microgravity of space, indicating a predominant pathogenetic role for visuo-sensory input. Scopolamine, dimenhydrinate, and promethazine reduce motion-related nystagmus. Contraction of extraocular muscles generates proprioceptive neural traffic and can provoke an ocular hypertensive response. It is proposed that repetitive contractions of the extraocular muscles during motion-related jerk nystagmus rapidly augment brain stem afferent input by increasing proprioceptive neural traffic through connections of the oculomotor nerves with the ophthalmic nerve in the lateral wall of the cavernous sinus as well as by raising the intraocular pressure thereby stimulating anterior segment ocular trigeminal nerve fibers. This verifiable hypothesis defines the pathophysiological basis of individual susceptibility to motion sickness, elucidates the preventive mechanism of gaze fixation or ocular closure, advances the aetiologic link between MS and migraine, rationalizes the mechanism of known preventive drugs, and explores new therapeutic possibilities.

Changes in Listing plane thickness caused by vestibular schwannoma: a parameter for evaluating the accuracy of the gravity-oriented internal model.

PubMed

Tsutsumi, Takeshi; Ikeda, Takuo; Watanabe, Kensuke; Kikuchi, Shigeru

2011-12-01

Three-dimensional analysis of video-oculograms can be used to calculate Listing plane for patients and experimental subjects. Listing plane reflects the head's orientation with respect to gravity, which suggests that the plane is derived from otolithic vestibular input, itself, or from a gravity-oriented internal model constructed through integration of visual, vestibular, and proprioceptive sensory inputs. The goal of this study was to determine whether the Listing plane can serve as a parameter for evaluating static (peripheral or central) vestibular function. Prospective study. Tertiary referral center. Healthy subjects and patients with unilateral vestibular schwannoma without any previous treatment. Diagnostic. Video-oculograms were recorded from healthy subjects (aged 36.8 ± 6.3 yr) and from patients (aged 60.3 ± 7.5 yr) during voluntary gaze with the head in an upright or each-side-down orientation, and the thicknesses of the calculated Listing planes were then compared. Results revealed thickening of the Listing plane in patients only when the head was in an impaired-side-down orientation (1.250 ± 0.795 and 1.074 ± 0.759 degrees in the right- and left-side-down head orientations in healthy subjects versus 2.222 ± 1.237 degrees in the impaired-side-down orientation in patients), and this thickening correlated with caloric weakness. By contrast, neither the sensation of postural instability nor postural disturbance in force platform recordings contributed to the thickness of Listing plane. The thickness of the Listing plane could be a novel parameter for quantitatively evaluating static vestibular (otolithic) function, although central compensation might exist.

HASHIMOTO THYROIDITIS AND VESTIBULAR DYSFUNCTION.

PubMed

Chiarella, Giuseppe; Russo, Diego; Monzani, Fabio; Petrolo, Claudio; Fattori, Bruno; Pasqualetti, Giuseppe; Cassandro, Ettore; Costante, Giuseppe

2017-07-01

The aim of this review was to analyze the existing literature concerning the relationship between Hashimoto thyroiditis (HT) and vestibular dysfunction. We used electronic databases (PubMed, EMBASE, Cochrane Library) to search and collect all published articles about the association between HT and vestibular disorders. Several observational and retrospective studies have postulated a relationship between thyroid autoimmunity and vestibular disorders. In most cases, an appropriate control group was lacking, and the impact of thyroid functional status could not precisely be established. In recent years, two well-designed prospective studies have provided convincing evidence that the association is not random. One article reported that patients with Ménière disease (MD) had a significantly higher prevalence of positive anti-thyroid autoantibody as compared to healthy controls. Moreover, more than half of MD patients had either positive anti-thyroid or non-organ-specific autoantibody titers, compared to less than 30% of both patients with unilateral vestibular paresis without cochlear involvement and healthy controls. Another study found that patients with benign paroxysmal positional vertigo (BPPV) had significantly higher serum thyroid-stimulating hormone and antithyroid autoantibody levels than healthy controls. Additionally, almost one-fifth of euthyroid patients with HT had signs of BPPV. The published results indicate that patients with MD or BPPV are potential candidates to also develop HT. Thus, in HT patients, the presence of even slight symptoms or signs potentially related to vestibular lesions should be carefully investigated. AITD = autoimmune thyroid disease; BPPV = benign paroxysmal positional vertigo; EH = endolymphatic hydrops; HT = Hashimoto thyroiditis; L-T 4 = L-thyroxine; MD = Ménière disease; PS = Pendred syndrome; Tg = thyroglobulin; TPO = thyroid peroxidase; TSH = thyroid-stimulating hormone.

[The significance of directional preponderance in the evaluation of vestibular function in patients with vertigo].

PubMed

Wang, J; Zhou, Y J; Yu, J; Gu, J

2017-03-07

Objective: To analyze the relationship between directional preponderance (DP), spontaneous nystagmus(SN) and vestibular disorders, and to investigate the significance of DP in directing peripheral vestibular function in patients with vertigo. Methods: This was a retrospective analysis of 394 cases diagnosed with peripheral vestibular disease accompanied by vertigo from March 2012 to June 2014 in the Outpatient Department of the Eye & ENT Hospital of Fudan University. Results of static and dynamic posture equilibrium tests, SN, unilateral weakness(UW), and DP in videonystagmography(VNG) were analyzed and compared. Results: The mean interval time between the last vertigo attack and examination in patients with SN or DP in caloric test were 4.4 d and 7.3 d respectively, and those without SN or DP were 18.3 d and 17.5 d respectively. The patients were divided into two groups according to DP results of caloric test. DP-normal group had 203 cases and DP-abnormal group had 191 cases. Spontaneous nystagmus was presented in 44 cases in the DP-normal group (21.67%) and four in the DP-abnormal group (2.09%). A significant difference was found between the two groups (χ 2 =35.27, P =0.000). Deficiency of vestibular function was noted in 165 cases in the DP-normal group (81.28%) and 123 (64.40%) in the DP-abnormal group in static and dynamic posture equilibrium tests. The difference between the two groups was statistically significant (χ 2 =14.26, P =0.000). Conclusion: Compared with DP-normal patients, DP-abnormal patients are more likely to have spontaneous nystagmus and balance disorders due to vestibular dysfunction.

Integration of vestibular and head movement signals in the vestibular nuclei during whole-body rotation

NASA Technical Reports Server (NTRS)

Gdowski, G. T.; McCrea, R. A.; Peterson, B. W. (Principal Investigator)

1999-01-01

Single-unit recordings were obtained from 107 horizontal semicircular canal-related central vestibular neurons in three alert squirrel monkeys during passive sinusoidal whole-body rotation (WBR) while the head was free to move in the yaw plane (2.3 Hz, 20 degrees /s). Most of the units were identified as secondary vestibular neurons by electrical stimulation of the ipsilateral vestibular nerve (61/80 tested). Both non-eye-movement (n = 52) and eye-movement-related (n = 55) units were studied. Unit responses recorded when the head was free to move were compared with responses recorded when the head was restrained from moving. WBR in the absence of a visual target evoked a compensatory vestibulocollic reflex (VCR) that effectively reduced the head velocity in space by an average of 33 +/- 14%. In 73 units, the compensatory head movements were sufficiently large to permit the effect of the VCR on vestibular signal processing to be assessed quantitatively. The VCR affected the rotational responses of different vestibular neurons in different ways. Approximately one-half of the units (34/73, 47%) had responses that decreased as head velocity decreased. However, the responses of many other units (24/73) showed little change. These cells had signals that were better correlated with trunk velocity than with head velocity. The remaining units had responses that were significantly larger (15/73, 21%) when the VCR produced a decrease in head velocity. Eye-movement-related units tended to have rotational responses that were correlated with head velocity. On the other hand, non-eye-movement units tended to have rotational responses that were better correlated with trunk velocity. We conclude that sensory vestibular signals are transformed from head-in-space coordinates to trunk-in-space coordinates on many secondary vestibular neurons in the vestibular nuclei by the addition of inputs related to head rotation on the trunk. This coordinate transformation is presumably important for controlling postural reflexes and constructing a central percept of body orientation and movement in space.

Vestibular Response to Electrical Stimulation of the Otolith Organs. Implications in the Development of A Vestibular Implant for the Improvement of the Sensation of Gravitoinertial Accelerations.

PubMed

Ramos de Miguel, Angel; Falcon Gonzalez, Juan Carlos; Ramos Macias, Angel

2017-08-01

Electrical stimulation of the utricular and saccular portions of the vestibular nerve improves stability in patients suffering from vestibular dysfunction. The main objective of this study was to evaluate a new technique, vestibular response telemetry (VRT), for measuring the electrically evoked vestibular compound action potential (saccular and utricular) after stimulating the otolith organ (saccular and utricular) in adults. This study used evidence that the otolith organ can be electrically stimulated in order to develop a new vestibular implant design to improve the sensation of gravitoinertial acceleration. Four adult patients were evaluated by using a variety of measurement procedures with novel VRT software. VRT values were obtained by stimulating with three full-band Nucleus CI24RE (ST) electrodes. Specific stimuli were used. Simultaneously, electrical ocular vestibular evoked myogenic potentials (eoVEMPs) were recorded in the contralateral side. Electrically evoked compound action potentials were obtained in 10 of the 12 electrodes tested, and eoVEMPs were recorded when VRT was present. In addition to the validation of this technique, a set of default clinical test parameters was established. The VRT response morphology consisted of a biphasic waveform with an initial negative peak (N1) followed by a positive peak (P1), and latencies were typically 400 μs for N1 and 800 μs for P1. The consequences for the development of a vestibular implant for the improvement of gravitoinertial acceleration sensation are also presented. The VRT measurement technique has been shown to be a useful tool to record neural response on the otolith organ, and thus it is a convenient tool to evaluate whether the implanted electrodes provide a neural response or not. This can be used for the early development of vestibular implants to improve gravitoinertial acceleration sensation.

A Low-Power ASIC Signal Processor for a Vestibular Prosthesis.

PubMed

Töreyin, Hakan; Bhatti, Pamela T

2016-06-01

A low-power ASIC signal processor for a vestibular prosthesis (VP) is reported. Fabricated with TI 0.35 μm CMOS technology and designed to interface with implanted inertial sensors, the digitally assisted analog signal processor operates extensively in the CMOS subthreshold region. During its operation the ASIC encodes head motion signals captured by the inertial sensors as electrical pulses ultimately targeted for in-vivo stimulation of vestibular nerve fibers. To achieve this, the ASIC implements a coordinate system transformation to correct for misalignment between natural sensors and implanted inertial sensors. It also mimics the frequency response characteristics and frequency encoding mappings of angular and linear head motions observed at the peripheral sense organs, semicircular canals and otolith. Overall the design occupies an area of 6.22 mm (2) and consumes 1.24 mW when supplied with ± 1.6 V.

A Low-Power ASIC Signal Processor for a Vestibular Prosthesis

PubMed Central

Töreyin, Hakan; Bhatti, Pamela T.

2017-01-01

A low-power ASIC signal processor for a vestibular prosthesis (VP) is reported. Fabricated with TI 0.35 μm CMOS technology and designed to interface with implanted inertial sensors, the digitally assisted analog signal processor operates extensively in the CMOS subthreshold region. During its operation the ASIC encodes head motion signals captured by the inertial sensors as electrical pulses ultimately targeted for in-vivo stimulation of vestibular nerve fibers. To achieve this, the ASIC implements a coordinate system transformation to correct for misalignment between natural sensors and implanted inertial sensors. It also mimics the frequency response characteristics and frequency encoding mappings of angular and linear head motions observed at the peripheral sense organs, semicircular canals and otolith. Overall the design occupies an area of 6.22 mm2 and consumes 1.24 mW when supplied with ± 1.6 V. PMID:26800546

Evidence that protons act as neurotransmitters at vestibular hair cell-calyx afferent synapses.

PubMed

Highstein, Stephen M; Holstein, Gay R; Mann, Mary Anne; Rabbitt, Richard D

2014-04-08

Present data support the conclusion that protons serve as an important neurotransmitter to convey excitatory stimuli from inner ear type I vestibular hair cells to postsynaptic calyx nerve terminals. Time-resolved pH imaging revealed stimulus-evoked extrusion of protons from hair cells and a subsequent buildup of [H(+)] within the confined chalice-shaped synaptic cleft (ΔpH ∼ -0.2). Whole-cell voltage-clamp recordings revealed a concomitant nonquantal excitatory postsynaptic current in the calyx terminal that was causally modulated by cleft acidification. The time course of [H(+)] buildup limits the speed of this intercellular signaling mechanism, but for tonic signals such as gravity, protonergic transmission offers a significant metabolic advantage over quantal excitatory postsynaptic currents--an advantage that may have driven the proliferation of postsynaptic calyx terminals in the inner ear vestibular organs of contemporary amniotes.

Tonic Investigation Concept of Cervico-vestibular Muscle Afferents

PubMed Central

Dorn, Linda Josephine; Lappat, Annabelle; Neuhuber, Winfried; Scherer, Hans; Olze, Heidi; Hölzl, Matthias

2016-01-01

Introduction Interdisciplinary research has contributed greatly to an improved understanding of the vestibular system. To date, however, very little research has focused on the vestibular system's somatosensory afferents. To ensure the diagnostic quality of vestibular somatosensory afferent data, especially the extra cranial afferents, stimulation of the vestibular balance system has to be precluded. Objective Sophisticated movements require intra- and extra cranial vestibular receptors. The study's objective is to evaluate an investigation concept for cervico-vestibular afferents with respect to clinical feasibility. Methods A dedicated chair was constructed, permitting three-dimensional trunk excursions, during which the volunteer's head remains fixed. Whether or not a cervicotonic provocation nystagmus (c-PN) can be induced with static trunk excursion is to be evaluated and if this can be influenced by cervical monophasic transcutaneous electrical nerve stimulation (c-TENS) with a randomized test group. 3D-video-oculography (VOG) was used to record any change in cervico-ocular examination parameters. The occurring nystagmuses were evaluated visually due to the small caliber of nystagmus amplitudes in healthy volunteers. Results The results demonstrate: no influence of placebo-controlled c-TENS on the spontaneous nystagmus; a significant increase of the vertical nystagmus on the 3D-trunk-excursion chair in static trunk flexion with cervical provocation in all young healthy volunteers (n = 49); and a significant difference between vertical and horizontal nystagmuses during static trunk excursion after placebo-controlled c-TENS, except for the horizontal nystagmus during trunk torsion. Conclusion We hope this cervicotonic investigation concept on the 3D trunk-excursion chair will contribute to new diagnostic and therapeutic perspectives on cervical pathologies in vestibular head-to-trunk alignment. PMID:28050208

Morphological evidence for local microcircuits in rat vestibular maculae

NASA Technical Reports Server (NTRS)

Ross, M. D.

1997-01-01

Previous studies suggested that intramacular, unmyelinated segments of vestibular afferent nerve fibers and their large afferent endings (calyces) on type I hair cells branch. Many of the branches (processes) contain vesicles and are presynaptic to type II hair cells, other processes, intramacular nerve fibers, and calyces. This study used serial section transmission electron microscopy and three-dimensional reconstruction methods to document the origins and distributions of presynaptic processes of afferents in the medial part of the adult rat utricular macula. The ultrastructural research focused on presynaptic processes whose origin and termination could be observed in a single micrograph. Results showed that calyces had 1) vesiculated, spine-like processes that invaginated type I cells and 2) other, elongate processes that ended on type II cells pre- as well as postsynaptically. Intramacular, unmyelinated segments of afferent nerve fibers gave origin to branches that were presynaptic to type II cells, calyces, calyceal processes, and other nerve fibers in the macula. Synapses with type II cells occurred opposite subsynaptic cisternae (C synapses); all other synapses were asymmetric. Vesicles were pleomorphic but were differentially distributed according to process origin. Small, clear-centered vesicles, approximately 40-60 nm in diameter, predominated in processes originating from afferent nerve fibers and basal parts of calyces. Larger vesicles approximately 70-120 nm in diameter having approximately 40-80 nm electron-opaque cores were dominant in processes originating from the necks of calyces. Results are interpreted to indicate the existence of a complex system of intrinsic feedforward (postsynaptic)-feedback (presynaptic) connections in a network of direct and local microcircuits. The morphological findings support the concept that maculae dynamically preprocess linear acceleratory information before its transmission to the central nervous system.

[Immunocytochemical study of cholinergic innervation in the neurosensory epithelia of human vestibule].

PubMed

Kong, W; Hussl, B; Schrott-Fischer, A

1998-02-01

To investigate the cholinergic innervation of the neurosensory epithelia of human vestibule. A modified preembedding immunostaining technique for immunoelectronmicroscopy was applied to this study. A polyclonal antibody to choline acetyltransferase (ChAT) was used as the marker of cholinergic fibers. ChAT-immunoreactive products were restricted to the nerve fibers and terminals which were rich in synaptic vesicles. The ChAT-immunoreactive fibers synaps with afferent chalice as well as with type II sensory hair cells. This study demonstrates that cholinergic fibers innervate the neurosensory epithelia of human vestible. The cholinergic fibers of human vestibular sensory epithelia belong to the vestibular efferent system.

Retrograde transport of (/sup 3/H)-D-aspartate label by cochlear and vestibular efferent neurons

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

Schwarz, D.W.; Schwarz, I.E.

1988-01-01

(/sup 3/H)-D-aspartic acid was injected into the inner ear of rats. After a six hour survival time, labeled cells were found at all locations known to contain efferent cochlear or vestibular neurons. Most labeled neurons were found in the ipsilateral lateral superior olivary nucleus (LSO), although both ventral nuclei of the trapezoid body (VTB), group E, and the caudal pontine reticular nucleus (CPR) just adjacent to the ascending limb of the facial nerve also contained labeled cells. Because not all efferent neurons in the rat could be previously shown to be cholinergic, aspartate and glutamate are efferent transmitter candidates.

OFO experimental techniques and preliminary conclusions - Is artificial gravity needed during prolonged weightlessness.

NASA Technical Reports Server (NTRS)

Gualtierotti, T.; Bracchi, F.

1972-01-01

The technique of single unit recording from body systems generating electrical pulses coherent with their basic function (CNS, muscles, sense organs) has been proved feasible during the OFO A orbital flight, an automatic physiological experiment. The results of recording 155 hours of orbital flight of pulses from the nerve fibres of four vestibular gravity sensors in two bull frogs indicate that the vestibular organ adjusts to zero g. As all the other biological changes observed during orbit are due to lack of exercise, it is concluded that artificial gravity might not be necessary during prolonged space missions or on low gravity celestial bodies.

Early extraction: a silver bullet to avoid nerve injury in lower third molar removal?

PubMed

Zhang, Q-B; Zhang, Z-Q

2012-10-01

This retrospective study evaluated the effects of early extraction of immature lower third molar on preventing complications, particularly nerve injury following lower third molar removal. Patients were grouped according to age and radiographic results: group A (518 patients, ≤23 years, immature teeth with apical foramen not closed); group B (532 patients, >23 years, mature teeth with closed apical foramen). Group A included 230 males and 288 females (average age 17 years). In group A, 808 lower mandibular third molars were extracted bilaterally in 290 and unilaterally in 228 patients; the incidence of complications was 2.48% (20/808) (all were temporary), the incidence of nerve injury was 0%. Group B included 250 males and 282 females (average age 39 years). In group B, 810 lower third molars were extracted bilaterally in 278 and unilaterally in 254 patients; the incidence of complications was 10% (81/810), the incidence of nerve injury was 1.6% (13/810). All complications were temporary, except two removals of permanent inferior alveolar nerve numbness (>6 months). In this study, early removal of the lower third molar was effective in avoiding some postoperative complications, especially nerve injury. Early extraction of lower third molar in youngsters is recommended following a team consultation. Copyright © 2012 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Monitored transoral endoscopic thyroidectomy via long monopolar stimulation probe.

PubMed

Dionigi, Gianlorenzo; Wu, Che-Wei; Tufano, Ralph P; Rizzo, Antonio Giacomo; Anuwong, Angkoon; Sun, Hui; Carcoforo, Paolo; Antonino, Cancellieri; Portinari, Mattia; Kim, Hoon Yub

2018-01-01

This video aimed to describe the role of intraoperative neuromonitoring (IONM) during transoral endoscopic thyroidectomy vestibular approach (TOETVA) with emphasis given to IONM technical and technological notes, the identification of recurrent laryngeal nerve (RLN). Standardized technique of IONM consist in identifying and monitoring both the vagus nerve and the RLNs before and after resection (V1, V2, R1, R2). According to this report, IONM during TOETVA is feasible and safe in providing identification and function of laryngeal nerves. IONM enable surgeons to feel more comfortable with their initial approach to TOETVA or extended indications. Larger series are needed for appropriated evaluation of IONM in reduction of the rates for RLN complications.

Monitored transoral endoscopic thyroidectomy via long monopolar stimulation probe

PubMed Central

Wu, Che-Wei; Tufano, Ralph P.; Rizzo, Antonio Giacomo; Anuwong, Angkoon; Sun, Hui; Carcoforo, Paolo; Antonino, Cancellieri; Portinari, Mattia; Kim, Hoon Yub

2018-01-01

This video aimed to describe the role of intraoperative neuromonitoring (IONM) during transoral endoscopic thyroidectomy vestibular approach (TOETVA) with emphasis given to IONM technical and technological notes, the identification of recurrent laryngeal nerve (RLN). Standardized technique of IONM consist in identifying and monitoring both the vagus nerve and the RLNs before and after resection (V1, V2, R1, R2). According to this report, IONM during TOETVA is feasible and safe in providing identification and function of laryngeal nerves. IONM enable surgeons to feel more comfortable with their initial approach to TOETVA or extended indications. Larger series are needed for appropriated evaluation of IONM in reduction of the rates for RLN complications. PMID:29445610

Further investigation of the spontaneous and evoked activity of the primary neurons of statoreceptors (and other receptors) of the labyrinth of the bullfrog before, during and after an extended period of weightlessness, including alternative intervals of artificial gravity

NASA Technical Reports Server (NTRS)

1977-01-01

Vestibular neuron activity was examined by studying nerve stimulation and evoked response. A cooling element, applied to the nerve consisted of a silver hook through which a coolant fluid flowed. Temperature changes were recorded via microtermistors on an eight channel brush recorder, together with response. Diffusion of the cooling effect was measured, recovery time was assessed, and the nerve was then studied hystologically and ultrastructurally. Problems in frog preparation were discussed along with problems in maintaining healthy specimens and bacteria controlled aquaria.

Vestibular evoked myogenic potential findings in multiple sclerosis.

PubMed

Escorihuela García, Vicente; Llópez Carratalá, Ignacio; Orts Alborch, Miguel; Marco Algarra, Jaime

2013-01-01

Multiple sclerosis is an inflammatory disease involving the occurrence of demyelinating, chronic neurodegenerative lesions in the central nervous system. We studied vestibular evoked myogenic potentials (VEMPs) in this pathology, to allow us to evaluate the saccule, inferior vestibular nerve and vestibular-spinal pathway non-invasively. There were 23 patients diagnosed with multiple sclerosis who underwent VEMP recordings, comparing our results with a control group consisting of 35 healthy subjects. We registered p13 and n23 wave latencies, interaural amplitude difference and asymmetry ratio between both ears. Subjects also underwent an otoscopy and audiometric examination. The prolongation of p13 and n23 wave latencies was the most notable characteristic, with a mean p13 wave latency of 19.53 milliseconds and a mean latency of 30.06 milliseconds for n23. In contrast, the asymmetry index showed no significant differences with our control group. In case of multiple sclerosis, the prolongation of the p13 and n23 VEMP wave latencies is a feature that has been attributed to slowing of conduction by demyelination of the vestibular-spinal pathway. In this regard, alteration of the response or lack thereof in these potentials has a locator value of injury to the lower brainstem. Copyright © 2013 Elsevier España, S.L. All rights reserved.

Characterization of pulse amplitude and pulse rate modulation for a human vestibular implant during acute electrical stimulation

NASA Astrophysics Data System (ADS)

Nguyen, T. A. K.; DiGiovanna, J.; Cavuscens, S.; Ranieri, M.; Guinand, N.; van de Berg, R.; Carpaneto, J.; Kingma, H.; Guyot, J.-P.; Micera, S.; Perez Fornos, A.

2016-08-01

Objective. The vestibular system provides essential information about balance and spatial orientation via the brain to other sensory and motor systems. Bilateral vestibular loss significantly reduces quality of life, but vestibular implants (VIs) have demonstrated potential to restore lost function. However, optimal electrical stimulation strategies have not yet been identified in patients. In this study, we compared the two most common strategies, pulse amplitude modulation (PAM) and pulse rate modulation (PRM), in patients. Approach. Four subjects with a modified cochlear implant including electrodes targeting the peripheral vestibular nerve branches were tested. Charge-equivalent PAM and PRM were applied after adaptation to baseline stimulation. Vestibulo-ocular reflex eye movement responses were recorded to evaluate stimulation efficacy during acute clinical testing sessions. Main results. PAM evoked larger amplitude eye movement responses than PRM. Eye movement response axes for lateral canal stimulation were marginally better aligned with PRM than with PAM. A neural network model was developed for the tested stimulation strategies to provide insights on possible neural mechanisms. This model suggested that PAM would consistently cause a larger ensemble firing rate of neurons and thus larger responses than PRM. Significance. Due to the larger magnitude of eye movement responses, our findings strongly suggest PAM as the preferred strategy for initial VI modulation.

Incomplete segregation of endorgan-specific vestibular ganglion cells in mice and rats

NASA Technical Reports Server (NTRS)

Maklad, A.; Fritzsch, B.

1999-01-01

The endorgan-specific distribution of vestibular ganglion cells was studied in neonatal and postnatal rats and mice using indocarbocyanine dye (DiI) and dextran amines for retrograde and anterograde labeling. Retrograde DiI tracing from the anterior vertical canal labeled neurons scattered throughout the whole superior vestibular ganglion, with denser labeling at the dorsal and central regions. Horizontal canal neurons were scattered along the dorsoventral axis with more clustering toward the dorsal and ventral poles of this axis. Utricular ganglion cells occupied predominantly the central region of the superior vestibular ganglion. This utricular population overlapped with both the anterior vertical and horizontal canals' ganglion cells. Posterior vertical canal neurons were clustered in the posterior part of the inferior vestibular ganglion. The saccular neurons were distributed in the two parts of the vestibular ganglion, the superior and inferior ganglia. Within the inferior ganglion, the saccular neurons were clustered in the anterior part. In the superior ganglion, the saccular neurons were widely scattered throughout the whole ganglion with more numerous neurons at the posterior half. Small and large neurons were labeled from all endorgans. Examination of the fiber trajectory within the superior division of the vestibular nerve showed no clear lamination of the fibers innervating the different endorgans. These results demonstrate an overlapping pattern between the different populations within the superior ganglion, while in the inferior ganglion, the posterior canal and saccular neurons show tighter clustering but incomplete segregation. This distribution implies that the ganglion cells are assigned for their target during development in a stochastic rather than topographical fashion.

Inputs from regularly and irregularly discharging vestibular nerve afferents to secondary neurons in squirrel monkey vestibular nuclei. III. Correlation with vestibulospinal and vestibuloocular output pathways

NASA Technical Reports Server (NTRS)

Boyle, R.; Goldberg, J. M.; Highstein, S. M.

1992-01-01

1. A previous study measured the relative contributions made by regularly and irregularly discharging afferents to the monosynaptic vestibular nerve (Vi) input of individual secondary neurons located in and around the superior vestibular nucleus of barbiturate-anesthetized squirrel monkeys. Here, the analysis is extended to more caudal regions of the vestibular nuclei, which are a major source of both vestibuloocular and vestibulospinal pathways. As in the previous study, antidromic stimulation techniques are used to classify secondary neurons as oculomotor or spinal projecting. In addition, spinal-projecting neurons are distinguished by their descending pathways, their termination levels in the spinal cord, and their collateral projections to the IIIrd nucleus. 2. Monosynaptic excitatory postsynaptic potentials (EPSPs) were recorded intracellularly from secondary neurons as shocks of increasing strength were applied to Vi. Shocks were normalized in terms of the threshold (T) required to evoke field potentials in the vestibular nuclei. As shown previously, the relative contribution of irregular afferents to the total monosynaptic Vi input of each secondary neuron can be expressed as a %I index, the ratio (x100) of the relative sizes of the EPSPs evoked by shocks of 4 x T and 16 x T. 3. Antidromic stimulation was used to type secondary neurons as 1) medial vestibulospinal tract (MVST) cells projecting to spinal segments C1 or C6; 2) lateral vestibulospinal tract (LVST) cells projecting to C1, C6; or L1; 3) vestibulooculo-collic (VOC) cells projecting both to the IIIrd nucleus and by way of the MVST to C1 or C6; and 4) vestibuloocular (VOR) neurons projecting to the IIIrd nucleus but not to the spinal cord. Most of the neurons were located in the lateral vestibular nucleus (LV), including its dorsal (dLV) and ventral (vLV) divisions, and adjacent parts of the medial (MV) and descending nuclei (DV). Cells receiving quite different proportions of their direct inputs from regular and irregular afferents were intermingled in all regions explored. 4. LVST neurons are restricted to LV and DV and show a somatotopic organization. Those destined for the cervical and thoracic cord come from vLV, from a transition zone between vLV and DV, and to a lesser extent from dLV. Lumbar-projecting neurons are located more dorsally in dLV and more caudally in DV. MVST neurons reside in MV and in the vLV-DV transition zone.(ABSTRACT TRUNCATED AT 400 WORDS).

[Facial nerve injuries cause changes in central nervous system microglial cells].

PubMed

Cerón, Jeimmy; Troncoso, Julieta

2016-12-01

Our research group has described both morphological and electrophysiological changes in motor cortex pyramidal neurons associated with contralateral facial nerve injury in rats. However, little is known about those neural changes, which occur together with changes in surrounding glial cells. To characterize the effect of the unilateral facial nerve injury on microglial proliferation and activation in the primary motor cortex. We performed immunohistochemical experiments in order to detect microglial cells in brain tissue of rats with unilateral facial nerve lesion sacrificed at different times after the injury. We caused two types of lesions: reversible (by crushing, which allows functional recovery), and irreversible (by section, which produces permanent paralysis). We compared the brain tissues of control animals (without surgical intervention) and sham-operated animals with animals with lesions sacrificed at 1, 3, 7, 21 or 35 days after the injury. In primary motor cortex, the microglial cells of irreversibly injured animals showed proliferation and activation between three and seven days post-lesion. The proliferation of microglial cells in reversibly injured animals was significant only three days after the lesion. Facial nerve injury causes changes in microglial cells in the primary motor cortex. These modifications could be involved in the generation of morphological and electrophysiological changes previously described in the pyramidal neurons of primary motor cortex that command facial movements.

Dizziness, migrainous vertigo and psychiatric disorders.

PubMed

Teggi, R; Caldirola, D; Colombo, B; Perna, G; Comi, G; Bellodi, L; Bussi, M

2010-03-01

This study sought to establish the prevalence of vestibular disorders, migraine and definite migrainous vertigo in patients with psychiatric disorders who were referred for treatment of dizziness, without a lifetime history of vertigo. Retrospective study. Out-patients in a university hospital. Fifty-two dizzy patients with panic disorders and agoraphobia, 30 with panic disorders without agoraphobia, and 20 with depressive disorders underwent otoneurological screening with bithermal caloric stimulation. The prevalence of migraine and migrainous vertigo was assessed. The level of dizziness was evaluated using the Dizziness Handicap Inventory. Dizzy patients with panic disorders and agoraphobia had a significantly p = 0.05 regarding the prevalence of peripheral vestibular abnormalities in the group of subjects with PD and agoraphobia and in those with depressive disorders. Migraine was equally represented in the three groups, but panic disorder patients had a higher prevalence of migrainous vertigo definite migrainous vertigo. Almost all patients with a peripheral vestibular disorder had a final diagnosis of definite migrainous vertigo according to Neuhauser criteria. These patients had higher Dizziness Handicap Inventory scores. The Dizziness Handicap Inventory total score was higher in the subgroup of patients with panic disorders with agoraphobia also presenting unilateral reduced caloric responses or definite migrainous vertigo, compared with the subgroup of remaining subjects with panic disorders with agoraphobia (p < 0.001). Our data support the hypothesis that, in patients with panic disorders (and especially those with additional agoraphobia), dizziness may be linked to malfunction of the vestibular system. However, the data are not inconsistent with the hypothesis that migrainous vertigo is the most common pathophysiological mechanism for vestibular disorders.

Evaluation of Dizziness Handicap in Adolescents and Adults with Auditory Neuropathy Spectrum Disorder

PubMed Central

Prabhu, Prashanth; Jamuar, Pratyasha

2018-01-01

Introduction  Vestibular symptoms and damage to the vestibular branch of the eighth cranial nerve is reported in individuals with auditory neuropathy spectrum disorder (ANSD). However, the real life handicap caused by these vestibular problems in individuals with ANSD is not studied. Objective  The present study attempted to evaluate the dizziness-related handicap in adolescents and adults with ANSD. Method  The dizziness handicap inventory (DHI) was administered to 40 adolescents and adults diagnosed with ANSD. The study also attempted to determine if there is any gender effect on DHI scores and its correlation to the reported onset of hearing loss. Results  The results of the study showed that adolescents and adults with ANSD had a moderate degree of dizziness-related handicap. The dizziness affected their quality of life, causing emotional problems. There was no gender effect, and the level of the handicap was greater in the cases in which the onset of the hearing loss was reported soon after the diagnosis of ANSD. There could be a vestibular compensation that could have resulted in a reduction in symptoms in individuals in whom the onset of the hearing loss was reported later on. Conclusion  Thus, a detailed assessment of vestibular problems and their impact on quality of life is essential in adolescents and adults with ANSD. Appropriate management strategies should be considered to resolve their vestibular problems and improve their quality of life. PMID:29371893

Evaluation of Dizziness Handicap in Adolescents and Adults with Auditory Neuropathy Spectrum Disorder.

PubMed

Prabhu, Prashanth; Jamuar, Pratyasha

2018-01-01

Introduction  Vestibular symptoms and damage to the vestibular branch of the eighth cranial nerve is reported in individuals with auditory neuropathy spectrum disorder (ANSD). However, the real life handicap caused by these vestibular problems in individuals with ANSD is not studied. Objective  The present study attempted to evaluate the dizziness-related handicap in adolescents and adults with ANSD. Method  The dizziness handicap inventory (DHI) was administered to 40 adolescents and adults diagnosed with ANSD. The study also attempted to determine if there is any gender effect on DHI scores and its correlation to the reported onset of hearing loss. Results  The results of the study showed that adolescents and adults with ANSD had a moderate degree of dizziness-related handicap. The dizziness affected their quality of life, causing emotional problems. There was no gender effect, and the level of the handicap was greater in the cases in which the onset of the hearing loss was reported soon after the diagnosis of ANSD. There could be a vestibular compensation that could have resulted in a reduction in symptoms in individuals in whom the onset of the hearing loss was reported later on. Conclusion  Thus, a detailed assessment of vestibular problems and their impact on quality of life is essential in adolescents and adults with ANSD. Appropriate management strategies should be considered to resolve their vestibular problems and improve their quality of life.

[Isolated palsy of the hypoglossal nerve complicating infectious mononucleosis].

PubMed

Carra-Dallière, C; Mernes, R; Juntas-Morales, R

2011-01-01

Neurological complications of infectious mononucleosis are rare. Various disorders have been described: meningitis, encephalitis, peripheral neuropathy. Isolated cranial nerve palsy has rarely been reported. A 16-year-old man was admitted for isolated and unilateral hypoglossal nerve palsy, four weeks after infectious mononucleosis. Cerebral MRI, cerebrospinal fluid study and electromyography were normal. IgM anti-VCA were positive. Two months later, without treatment, the tongue had almost fully recovered. To the best of our knowledge, only seven cases of isolated palsy of the hypoglossal nerve complicating infectious mononucleosis have been previously reported. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Newly Diagnosed Meniere's Disease: Clinical Course With Initiation of Noninvasive Treatment Including an Accounting of Vestibular Migraine.

PubMed

Sbeih, Firas; Christov, Florian; Gluth, Michael B

2018-05-01

To describe the course of Meniere's disease with noninvasive treatment during the first few years after initial diagnosis. A retrospective review of consecutive patients with newly diagnosed definite Meniere's disease between 2013 and 2016 and a minimum follow-up of 1 year. Patients received a written plan for low sodium, water therapy, and treatment with a diuretic and/or betahistine. Subjects were screened and treated for vestibular migraine as needed. Vertigo control and hearing status at most recent follow-up were assessed. Forty-four subjects had an average follow up of 24.3 months. Thirty-four percent had Meniere's disease and vestibular migraine, and 84% had unilateral Meniere's disease. Seventy-five percent had vertigo well controlled at most recent follow-up, with only noninvasive treatments. Age, gender, body mass index, presence of vestibular migraine, bilateral disease, and duration of follow-up did not predict noninvasive treatment failure. Worse hearing threshold at 250 Hz and lower pure tone average (PTA) at the time of diagnosis did predict failure. Fifty-two percent of ears had improved PTA at most recent visit, 20% had no change, and 28% were worse Conclusions: Encountering excellent vertigo control and stable hearing after a new diagnosis of Meniere's disease is possible with noninvasive treatments. Worse hearing status at diagnosis predicted treatment failure.

Susceptibility to Fear of Heights in Bilateral Vestibulopathy and Other Disorders of Vertigo and Balance

PubMed Central

Brandt, Thomas; Grill, Eva; Strupp, Michael; Huppert, Doreen

2018-01-01

Aims: To determine the susceptibility to visual height intolerance (vHI) in patients with acquired bilateral vestibulopathy (BVP). The question was whether postural instability in BVP, which is partially compensated for by visual substitution of the impaired vestibular control of balance, leads to an increased susceptibility. This is of particular importance since fear of heights is dependent on body posture, and visual control of balance at heights can no longer substitute vestibular input. For comparison susceptibility to vHI was determined in patients with other vestibular or functional disorders. Methods: A total of 150 patients aged 18 or above who had been referred to the German Center for Vertigo and Balance Disorders and diagnosed to have BVP were surveyed with a standardized questionnaire by specifically trained neurological professionals. Further, 481 patients with other vestibular or functional disorders were included. Results: Susceptibility to vHI was reported by 29% (32 % in females, 25% in males) of the patients with BVP. Patients with vHI were slightly younger (67 vs. 71 years). Seventy percent of those with vHI reported avoidance of climbing, hiking, stairs, darkness, cycling or swimming (84% of those without vHI). Mean age for onset of vHI was 40 years. Susceptibility to vHI was higher in patients with other vertigo disorders than in those with BVP: 64% in those with phobic postural vertigo, 61% in vestibular migraine, 56% in vestibular paroxysmia, 54% in benign paroxysmal positional vertigo, 49% in unilateral vestibulopathy and 48% in Menière's disease. Conclusions: The susceptibility to vHI in BVP was not higher than that of the general population (28%).This allows two explanations that need not be alternatives but contribute to each other: (1) Patients with a bilateral peripheral vestibular deficit largely avoid exposure to heights because of their postural instability. (2) The irrational anxiety to fall from heights triggers increased susceptibility to vHI, not the objective postural instability. However, patients with BVP do not exhibit increased comorbid anxiety disorders. This view is supported by the significantly increased susceptibility to vHI in other vestibular syndromes, which are characterized by an increased comorbidity of anxiety disorders.

Evolution of Gravity Receptors in the Ear

NASA Technical Reports Server (NTRS)

Popper, Arthur N. (Principal Investigator)

1996-01-01

The general status of a grant to investigate the origins and evolution of two hair cell types in the ears of a teleost fish, Astronotus ocellatus (the oscar), is presented. First, it was demonstrated that the cells in the rostral end of the saccule of the , Carassius auratus, are type 1-like, while those at the caudal end are type 2 cells. It was demonstrated that the dichotomy of hair cell types found in the utricle of the oscar is also found in the goldfish. Second, the lateral line system of the oscar was examined using gentamicin sulphate, an ototocix drug that destroys type 1- like hair cells but does not appear to damage type 2 hair cells. It was demonstrated that the hair cells found in neuromasts of lateral line canal organs were totally destroyed within 1 day of treatment, while the hair cells in free neuromasts were undamaged after 12 days of treatment. Third, it was demonstrated that the calyx, the specialized nerve ending, is not unique to amniotes and that it is present at least in the cristae of semicirular canals in goldfish. These results have demonstrated that: (1) there are multiple hair cell types in the vestibular endorgans of the ear of fishes, (2) these hair cell types are very similar to those found in the mammalian vestibular endorgans, (3) the nerve calyx is also present in fishes, and (4) multiple hair cell types and the calyx have evolved far earlier in the course of vertebrate evolution than heretofore thought. Understanding the structure of the vestibular endorgans has important implications for being able to understand how these organs respond to gravistatic, acceleration and acoustic input. The vestibular endorgans of fishes may provide an ideal system in which to analyze functional differences in hair cells. Not only are the two hair cell types similar to those found in mammals, they are located in very discrete regions in each endorgan. Thus, it is relatively easy to gain access to cells of one or the other type. The presence of two cell types in the lateral line have equally significant implications for studies of the vestibular system.

Leukemic optic neuropathy.

PubMed

Brown, G C; Shields, J A; Augsburger, J J; Serota, F T; Koch, P

1981-03-01

The clinical course and ophthalmic manifestations of an eight year old child with acute undifferentiated leukemia and unilateral blindness secondary to leukemic optic nerve head infiltration are described. At autopsy the involved nerve head and peripapillary retina demonstrated massive leukemic cell infiltration and hemorrhagic necrosis. This manifestation of leukemia is quite uncommon and prognosis for life in such cases is poor with existing methods of therapy.

Tic douloureux.

PubMed

Sweeney, P J

1981-02-01

Tic douloureux (trigerminal neuralgia) usually has its onset in the sixth or seventh decade and is characterized by severe, excruciating facial pain which is almost always unilateral. The mandibular division and the maxillary division of the fifth cranial nerve are most commonly affected. Carbamazepine is the drug of choice. Currently popular surgical procedures include decompression of the fifth cranial nerve and percutaneous thermal lesioning of the gasserian ganglion.

[Extended middle fossa approach in treatment of vestibular schwannoma--technique of surgery and postoperative complications].

PubMed

Jamróz, Barbara; Niemczyk, Kazimierz; Morawski, Krzysztof; Bartoszewicz, Robert

2010-06-01

The main tumor of cerebellopontine angle are vestibular schwannoma (80-90%). According to National Institute of Health Consensus Development Conference the best treatment method is microsurgery. There are three principal surgical approaches: translabyrinthin, retrosigmoid and middle fossa. Only the latter two approaches provide the possibility of hearing preservation. Technique of surgery and postoperative morbidity after MFA. 39 patients (40 tumor) suffered from tumor of cerebellopontine angle, operated by using middle fossa approach in years 1998-2007. We evaluate hearing preservation and function of facial nerve and others postoperative morbidity. 22.5% of patients has hearing impairment and 32.5% has facial weakness. By individual cases we observed: CSF leak, meningitis, corneal ulceration, ischialgia, wound bleeding and venue thrombosis. 1/3 of patients suffered from headache and disequilibrium and 1/6 suffered from tinnitus. According to NIH middle fossa approach is one of three possible approaches in microsurgery of cerebellopontine angle tumors. There is possible total tumor removal with hearing preservation. Monitoring of facial and cochlear nerve during operation is recommended.

Middle Fossa Approach for Vestibular Schwannoma: Good Hearing and Facial Nerve Outcomes with Low Morbidity.

PubMed

Raheja, Amol; Bowers, Christian A; MacDonald, Joel D; Shelton, Clough; Gurgel, Richard K; Brimley, Cameron; Couldwell, William T

2016-08-01

The middle fossa approach (MFA) is not used as frequently as the traditional translabyrinthine and retrosigmoid approaches for accessing vestibular schwannomas (VSs). Here, MFA was used to remove primarily intracanalicular tumors in patients in whom hearing preservation is a goal of surgery. A retrospective chart review was performed to identify consecutive adult patients who underwent MFA for VS. Demographic profile, perioperative complications, pre- and postoperative hearing, and facial nerve outcomes were analyzed with linear regression analysis to identify factors predicting hearing outcome. Among 78 identified patients (mean age, 49 years; 53% female; mean tumor size, 7.5 mm), 78% had functional hearing preoperatively (American Academy of Otolaryngology-Head and Neck Surgery class A/B). Follow-up audiologic data were available for 60 patients overall (mean follow-up, 15.1 months). The hearing preservation rate was 75.5% (37/49) at last known follow-up for patients with functional hearing preoperatively. Other than preoperative hearing status (P < 0.001), none of the factors assessed, including demographic profile, size of tumor, and fundal fluid cap, predicted hearing preservation (P > 0.05). Good functional preservation of the facial nerve (House-Brackmann class I/II) was achieved in 90% of patients. The only operative complications were 3 wound infections (3.8%). Preliminary results from this single-center retrospective study of patients undergoing MFA for resection of VS showed that good hearing preservation and facial nerve outcomes could be achieved with few complications. These results suggest that resection via the MFA is a rational alternative to watchful waiting or stereotactic radiosurgery. Copyright © 2016 Elsevier Inc. All rights reserved.

Unilateral or "side-locked" migrainous headache with autonomic symptoms linked to night guard use.

PubMed

Strahlendorf, Jean; Schiffer, Randolph; Strahlendorf, Howard

2008-01-01

Night guards are commonly prescribed as a palliative measure for bruxism, temporomandibular joint symptoms, and associated disorders. We describe a patient with a 10- to 12-year history of night guard use with concurrent unilateral side-locked migrainous headaches with autonomic symptoms characteristic of trigeminal autonomic cephalgia. These headaches were refractory to numerous pharmacological interventions. Upon self-initiated cessation of night guard use, there was complete remission of headaches. We believe the headaches were initiated by night guard-initiated irritation of the trigeminal nerve and a trigeminal autonomic reflex resulting in unilateral migrainous headache with autonomic signs.

Restoring penis sensation in patients with low spinal cord lesions: the role of the remaining function of the dorsal nerve in a unilateral or bilateral TOMAX procedure.

PubMed

Overgoor, Max L E; Braakhekke, Jan P; Kon, Moshe; De Jong, Tom P V M

2015-04-01

The recently developed TOMAX-procedure restores unilateral genital sensation, improving sexual health in men with a low spinal lesion (LSL). It connects one dorsal nerve of the penis (DNP) to the intact ipsilateral ilioinguinal nerve. We proposed bilateral neurotization for full sensation of the glans but this entails cutting both DNPs, risking patients' erection/ejaculation ability. The objective was to select patients for a bilateral TOMAX-procedure by measuring remaining DNP function, and perform the first bilateral cases. In 30 LSL patients with no penile- but normal groin sensation selected for a unilateral TOMAX-procedure the integrity of the sacral-reflex-arc and DNP function was tested pre-operatively using bilateral needle electromyography (EMG)-bulbocavernosus reflex (BCR) measurements, and an interview about reflex erections (RE) ability. In 13 spina bifida- and 17 spinal cord injury patients [median age 29.5 years (range 13-59 years), spinal lesion T12 (incomplete) to sacral], seven (23%) patients reported RE, four (57%) with intact BCR, and of nine (30%) patients with intact BCR, four reported RE (44%). Even patients with a LSL and no penile sensation can have signs of remaining DNP function, but cutting both DNPs to restore full glans sensation in a bilateral TOMAX-procedure might interfere with their RE/ejaculation. To avoid this risk, we propose a selecting-protocol for a unilateral- or bilateral procedure using RE and BCR measurements. Using this protocol, three patients were bilaterally operated with promising preliminary results. Full sensation of the glans could lead to further improvement in sexual function. © 2014 Wiley Periodicals, Inc.

Weight bearing of the limb as a confounding factor in assessment of mechanical allodynia in the rat.

PubMed

Kauppila, T; Kontinen, V K; Pertovaara, A

1998-01-01

Effect of weight bearing of the hindlimbs on the assessment of mechanically-induced hindlimb withdrawal threshold was determined in intact rats and in rats with various pathophysiological conditions causing allodynia or hyperalgesia. Hindlimb withdrawal was elicited by applying a series of calibrated monofilaments to the plantar or the dorsal surface of the paw. During testing the rat was either in a restraint tube with hindlimbs hanging semi-extended without weight bearing or it was standing on a metal grid (bearing its own weight). In intact rats, the withdrawal thresholds were significantly lower when the stimulus site was the dorsal hairy skin rather than the plantar glabrous skin. Also, thresholds were significantly lower when the hindlimbs were not bearing weight. Following carrageenan-induced unilateral inflammation of the plantar paw or a tibial nerve cut there was a marked threshold decrease to test stimuli applied to plantar or dorsal paw, respectively, ipsilateral to the pathological condition in standing rats. However, when the hindlimbs were not weight bearing the unilateral threshold decrease was markedly attenuated (carrageenan-treated rats) or completely abolished (tibial cut). In contrast, in rats with a unilateral spinal nerve ligation the threshold decrease ipsilateral to the nerve lesion was highly significant independent of the weight bearing of the hindlimbs. The results indicate that weight bearing of hindlimbs is an important confounding factor in the assessment of tactile allodynia in rats.

Fungiform taste bud degeneration in C57BL/6J mice following chorda-lingual nerve transection.

PubMed

Guagliardo, Nick A; Hill, David L

2007-09-10

Taste buds are dependent on innervation for normal morphology and function. Fungiform taste bud degeneration after chorda tympani nerve injury has been well documented in rats, hamsters, and gerbils. The current study examines fungiform taste bud distribution and structure in adult C57BL/6J mice from both intact taste systems and after unilateral chorda-lingual nerve transection. Fungiform taste buds were visualized and measured with the aid of cytokeratin 8. In control mice, taste buds were smaller and more abundant on the anterior tip (<1 mm) of the tongue. By 5 days after nerve transection taste buds were smaller and fewer on the side of the tongue ipsilateral to the transection and continued to decrease in both size and number until 15 days posttransection. Degenerating fungiform taste buds were smaller due to a loss of taste bud cells rather than changes in taste bud morphology. While almost all taste buds disappeared in more posterior fungiform papillae by 15 days posttransection, the anterior tip of the tongue retained nearly half of its taste buds compared to intact mice. Surviving taste buds could not be explained by an apparent innervation from the remaining intact nerves. Contralateral effects of nerve transection were also observed; taste buds were larger due to an increase in the number of taste bud cells. These data are the first to characterize adult mouse fungiform taste buds and subsequent degeneration after unilateral nerve transection. They provide the basis for more mechanistic studies in which genetically engineered mice can be used. (c) 2007 Wiley-Liss, Inc.

Facial reanimation with gracilis muscle transfer neurotized to cross-facial nerve graft versus masseteric nerve: a comparative study using the FACIAL CLIMA evaluating system.

PubMed

Hontanilla, Bernardo; Marre, Diego; Cabello, Alvaro

2013-06-01

Longstanding unilateral facial paralysis is best addressed with microneurovascular muscle transplantation. Neurotization can be obtained from the cross-facial or the masseter nerve. The authors present a quantitative comparison of both procedures using the FACIAL CLIMA system. Forty-seven patients with complete unilateral facial paralysis underwent reanimation with a free gracilis transplant neurotized to either a cross-facial nerve graft (group I, n=20) or to the ipsilateral masseteric nerve (group II, n=27). Commissural displacement and commissural contraction velocity were measured using the FACIAL CLIMA system. Postoperative intragroup commissural displacement and commissural contraction velocity means of the reanimated versus the normal side were first compared using the independent samples t test. Mean percentage of recovery of both parameters were compared between the groups using the independent samples t test. Significant differences of mean commissural displacement and commissural contraction velocity between the reanimated side and the normal side were observed in group I (p=0.001 and p=0.014, respectively) but not in group II. Intergroup comparisons showed that both commissural displacement and commissural contraction velocity were higher in group II, with significant differences for commissural displacement (p=0.048). Mean percentage of recovery of both parameters was higher in group II, with significant differences for commissural displacement (p=0.042). Free gracilis muscle transfer neurotized by the masseteric nerve is a reliable technique for reanimation of longstanding facial paralysis. Compared with cross-facial nerve graft neurotization, this technique provides better symmetry and a higher degree of recovery. Therapeutic, III.

Properties and connections of cat fastigiospinal neurons.

PubMed

Wilson, V J; Uchino, Y; Maunz, R A; Susswein, A; Fukushima, K

1978-05-12

1. Neurons in the cat fastigial nucleus that project to the upper cervical spinal segments (fastigiospinal neurons) were fired by antidromic stimulation of the contralateral spinal cord. Dye ejection from the recording electrode was used to show that most neurons were in the rostral half of the fastigial nucleus. 2. Fastigiospinal neurons can be excited and/or inhibited by stimulation of forelimb and hindlimb nerves and by stimulation of the vestibular nerve. These inputs converge on many neurons. 3. Antidromic microstimulation was used to trace fastigiospinal axons to the vicinity of motor nuclei in in C2-C3. 4. The rostral fastigial nucleus was stimulated in preparations with the medial longitudinal fasciculus transected by a wide lesion that impinged on the medial reticular formation in the caudal medulla, to eliminate some potential axon reflexes. Short-latency EPSPs were recorded in some trapezius and biventer-cervicis motoneurons. In many cases there was little or no occlusion between these EPSPs and others evoked by stimulation of the vestibular nerve ipsilateral to the motoneurons. 5. Movement of the stimulating electrode and placement of this electrode lateral to the fastigial nucleus show that the zone from which low threshold EPSPs can be evoked is localized. 6. Latency measurements and lack of temporal facilitation with double shocks suggest that the EPSPs are monosynaptic. The evidence suggests that they are caused by fastigiospinal fibers terminating on motoneurons.

Sympathetic preganglionic efferent and afferent neurons mediated by the greater splanchnic nerve in rabbit

NASA Technical Reports Server (NTRS)

Torigoe, Yasuhiro; Cernucan, Roxana D.; Nishimoto, Jo Ann S.; Blanks, Robert H. I.

1985-01-01

As a part of the study of the vestibular-autonomic pathways involved in motion sickness, the location and the morphology of preganglionic sympathetic neurons (PSNs) projecting via the greater splanchnic nerve were examined. Retrograde labeling of neurons was obtained by application of horseradish peroxidase to the cut end of the greater splanchnic nerve. Labeled PSNs were found, ipsilaterally, within the T1 to T11 spinal cord segments, with the highest density of neurons in T6. Most PSNs were located within the intermediolateral column, but a significant portion also occurred within the lateral funiculus, the intercalated region, and the central autonomic area; the proportion of labeling between the four regions depended on the spinal cord segment.

Predicting Nonauditory Adverse Radiation Effects Following Radiosurgery for Vestibular Schwannoma: A Volume and Dosimetric Analysis

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

Hayhurst, Caroline; Monsalves, Eric; Bernstein, Mark

2012-04-01

Purpose: To define clinical and dosimetric predictors of nonauditory adverse radiation effects after radiosurgery for vestibular schwannoma treated with a 12 Gy prescription dose. Methods: We retrospectively reviewed our experience of vestibular schwannoma patients treated between September 2005 and December 2009. Two hundred patients were treated at a 12 Gy prescription dose; 80 had complete clinical and radiological follow-up for at least 24 months (median, 28.5 months). All treatment plans were reviewed for target volume and dosimetry characteristics; gradient index; homogeneity index, defined as the maximum dose in the treatment volume divided by the prescription dose; conformity index; brainstem; andmore » trigeminal nerve dose. All adverse radiation effects (ARE) were recorded. Because the intent of our study was to focus on the nonauditory adverse effects, hearing outcome was not evaluated in this study. Results: Twenty-seven (33.8%) patients developed ARE, 5 (6%) developed hydrocephalus, 10 (12.5%) reported new ataxia, 17 (21%) developed trigeminal dysfunction, 3 (3.75%) had facial weakness, and 1 patient developed hemifacial spasm. The development of edema within the pons was significantly associated with ARE (p = 0.001). On multivariate analysis, only target volume is a significant predictor of ARE (p = 0.001). There is a target volume threshold of 5 cm3, above which ARE are more likely. The treatment plan dosimetric characteristics are not associated with ARE, although the maximum dose to the 5th nerve is a significant predictor of trigeminal dysfunction, with a threshold of 9 Gy. The overall 2-year tumor control rate was 96%. Conclusions: Target volume is the most important predictor of adverse radiation effects, and we identified the significant treatment volume threshold to be 5 cm3. We also established through our series that the maximum tolerable dose to the 5th nerve is 9 Gy.« less

Neural readaptation to Earth's gravity following return from space.

PubMed

Boyle, R; Mensinger, A F; Yoshida, K; Usui, S; Intravaia, A; Tricas, T; Highstein, S M

2001-10-01

The consequence of exposure to microgravity on the otolith organs was studied by recording the responses of vestibular nerve afferents supplying the utricular otolith organ to inertial accelerations in four toadfish, Opsanus tau, sequentially for 5 days following two National Aeronautics and Space Administration shuttle orbital flights. Within the first day postflight, the magnitude of response to an applied translation was on average three times greater than for controls. The reduced gravitational acceleration in orbit apparently resulted in an upregulation of the sensitivity of utricular afferents. By 30 h postflight, responses were statistically similar to control. The time course of return to normal afferent sensitivity parallels the reported decrease in vestibular disorientation in astronauts following return from space.

Neural readaptation to Earth's gravity following return from space

NASA Technical Reports Server (NTRS)

Boyle, R.; Mensinger, A. F.; Yoshida, K.; Usui, S.; Intravaia, A.; Tricas, T.; Highstein, S. M.

2001-01-01

The consequence of exposure to microgravity on the otolith organs was studied by recording the responses of vestibular nerve afferents supplying the utricular otolith organ to inertial accelerations in four toadfish, Opsanus tau, sequentially for 5 days following two National Aeronautics and Space Administration shuttle orbital flights. Within the first day postflight, the magnitude of response to an applied translation was on average three times greater than for controls. The reduced gravitational acceleration in orbit apparently resulted in an upregulation of the sensitivity of utricular afferents. By 30 h postflight, responses were statistically similar to control. The time course of return to normal afferent sensitivity parallels the reported decrease in vestibular disorientation in astronauts following return from space.

[Segmental schwannomatosis in upper-extremity: 5 cases report and literature review].

PubMed

Wang, Zhi-Xin; Chen, Shan-Lin; Yi, Chuan-Jun; Li, Chun; Rong, Yan-Bo; Tian, Guang-Lei

2013-10-18

Multiple schwannomas localized in a single body part not crossing the midline constitute a rare variant of neurofibromatosis, segmental schwannomatosis. We report our experience with 5 cases of segmental schwannomatosis of the upper extremity and review the related literature to improve our skills in diagnosis and differentiation. Five patients with segmental schwannomatosis received surgical treatment in our department from 2003 to 2012, of whom 4 were female and the other one male. The mean age was 38 years, ranging from 29 to 48 years. In retrospect, we discussed the clinical appearance, histologic characteristics, genetic data and surgical management. A total of 351 patients with schwannomas were treated in the recent decade. There were 326 patients with solitary schwannoma, accounting for 92.88%, 25 with neurofibromatosis type 2 (NF-2), occupying 7.12% and 5 with segmental schwannomatosis representing 1.42% of the total. Schwannomas are limited in one upper extremity and randomly located at ulnar nerve, median nerve and radial nerve and their branches, with no obvious predisposition. Their family history was negative for cutaneous tumors or central nervous system disease. Neurological examinations did not reveal symptoms related to vestibular nerves or optic nerves, which excluded NF-2 preliminarily. The prior symptom of three cases was pain which could be irradiated to the nerve distribution area. No pain but slight numbness was found in two cases. MRI disclosed multiple masses along the course of the nerves. They were isointense to muscle on T1-weighed images and hyperintense to subcutaneous fat on T2-weighed images. All schwannomas were resected and histological sections exhibited a characteristic feature of schwannoma. Follow-up work of 4.5 years was done to 4 cases and no recurrence or impairment of nerves was found. Segmental schwannomatosis is characterized by multiple schwannomas localized in one limb (upper extremity in our cases) without vestibular nerve tumors, most frequently seen in females at the age of 30-60 years. Segmental schwannomatosis is rarely seen in the previous literature. We found around 20 cases in English articles and no cases in domestic articles. In consideration of the clinical appearances of these 5 cases and the genetic research in the related literature, we recommend that segmental schwannomatosis is a distinct form of neurofibromatosis which needs to be more studied. We should also pay more attention to differentiating this disease from other forms of neurofibromatosis.

Neurological abnormalities associated with CDMA exposure.

PubMed

Hocking, B; Westerman, R

2001-09-01

Dysaesthesiae of the scalp and neurological abnormality after mobile phone use have been reported previously, but the roles of the phone per se or the radiations in causing these findings have been questioned. We report finding a neurological abnormality in a patient after accidental exposure of the left side of the face to mobile phone radiation [code division multiple access (CDMA)] from a down-powered mobile phone base station antenna. He had headaches, unilateral left blurred vision and pupil constriction, unilateral altered sensation on the forehead, and abnormalities of current perception thresholds on testing the left trigeminal ophthalmic nerve. His nerve function recovered during 6 months follow-up. His exposure was 0.015-0.06 mW/cm(2) over 1-2 h. The implications regarding health effects of radiofrequency radiation are discussed.

Psychological comorbidities and their relationship to self-reported handicap in samples of dizzy patients.

PubMed

Piker, Erin G; Jacobson, Gary P; McCaslin, Devin L; Grantham, Sarah L

2008-04-01

Factors such as anxiety, depression, somatic awareness, autonomic symptoms, and differences in coping strategies are known to affect dizziness handicap. We studied these factors in 63 consecutive "dizzy" patients. This sample was subgrouped into normals and patients with benign paroxysmal positional vertigo, compensated and uncompensated unilateral peripheral vestibular system impairment, or abnormal vestibular evoked myogenic potential as a single significant diagnostic finding. Results showed that (1) anxiety and depression occur with greater frequency in dizzy patients than in the normal population; (2) the magnitude of anxiety, depression, somatization, and autonomic symptoms does not differ significantly in subgroups of patients; (3) women tended to report greater handicap and somatic/autonomic symptoms; and (4) Dizziness Handicap Inventory total scores were correlated with patients' complaints of somatic/autonomic symptoms, anxiety, depression, and coping strategies. These findings suggest that self-reported measures represent unique pieces of information important for the management of dizzy patients.

Acute vestibular syndrome: clinical head impulse test versus video head impulse test.

PubMed

Celebisoy, Nese

2018-03-05

HINTS battery involving head impulse test (HIT), nystagmus, and test of skew is the critical bedside examination to differentiate acute unilateral peripheral vestibulopathy from posterior circulation stroke (PCS) in acute vestibular syndrome (AVS). The highest sensitivity component of the battery has been reported to be the horizontal HIT, whereas skew deviation is defined as the most specific but non-sensitive sign for PCS. Video-oculography-based HIT (vHIT) may have an additional power in making the differentiation. If vHIT is undertaken, then both gain and gain asymmetry should be taken into account as anterior inferior cerebellar artery (AICA) strokes are at risk of being misclassified based on VOR gain alone. Further refinement in video technology, increased operator proficiency and incorporation with saccade analysis will increase the sensitivity of vHIT for PCS diagnosis. For the time being, clinical examination seems adequate in frontline diagnostic evaluation of AVS.

Herpes zoster ophthalmicus and strabismus: a unique cause of secondary Brown syndrome.

PubMed

Broderick, Kevin M; Raymond, William R; Boden, John H

2017-08-01

Herpes zoster ophthalmicus can be associated with a variety of ocular and visual sequelae, including isolated or even multiple cranial neuropathies, potentially affecting the oculomotor, trochlear, or abducens nerves. We report a case of a secondary Brown syndrome following resolution of a unilateral isolated trochlear nerve palsy associated with herpes zoster ophthalmicus in an immunocompetent 57-year-old man. Published by Elsevier Inc.

A novel technique to identify the nerve of origin in head and neck schwannomas.

PubMed

Ching, H H; Spinner, A G; Reeve, N H; Wang, R C

2018-04-18

Identifying the nerve of origin in head and neck schwannomas is a diagnostic challenge. Surgical management leads to a risk of permanent deficit. Accurate identification of the nerve would improve operative planning and patient counselling. Three patients with head and neck schwannomas underwent a diagnostic procedure hypothesised to identify the nerve of origin. The masses were infiltrated with 1 per cent lidocaine solution, and the patients were observed for neurological deficits. All three patients experienced temporary loss of nerve function after lidocaine injection. Facial nerve palsy, voice changes with documented unilateral same-side vocal fold paralysis, and numbness in the distribution of the maxillary nerve (V2), respectively, led to a likely identification of the nerve of origin. Injection of lidocaine into a schwannoma is a safe, in-office procedure that produces a temporary nerve deficit, which may enable accurate identification of the nerve of origin of a schwannoma. Identifying the nerve of origin enhances operative planning and patient counselling.

Recurrent Isolated Oculomotor Nerve Palsy after Radiation of a Mesencephalic Metastasis. Case Report and Mini Review

PubMed Central

Grabau, Olga; Leonhardi, Jochen; Reimers, Carl D.

2014-01-01

Introduction: Recurrent oculomotor nerve palsies are extremely rare clinical conditions. Case report: Here, we report on a unique case of a short-lasting recurrent unilateral incomplete external and complete internal oculomotor nerve palsy. The episodic palsies were probably caused by an ipsilateral mesencephalic metastasis of a breast carcinoma and occurred after successful brain radiation therapy. Discussion: While the pathogenic mechanism remains unclear, the recurrent sudden onset and disappearance of the palsies and their decreasing frequency after antiepileptic treatment suggest the occurrence of epilepsy-like brainstem seizures. A review of case reports of spontaneous reversible oculomotor nerve palsies is presented. PMID:25104947

Galvanic vestibular stimulation speeds visual memory recall.

PubMed

Wilkinson, David; Nicholls, Sophie; Pattenden, Charlotte; Kilduff, Patrick; Milberg, William

2008-08-01

The experiments of Alessandro Volta were amongst the first to indicate that visuo-spatial function can be altered by stimulating the vestibular nerves with galvanic current. Until recently, the beneficial effects of the procedure were masked by the high levels of electrical current applied, which induced nystagmus-related gaze deviation and spatial disorientation. However, several neuropsychological studies have shown that much weaker, imperceptible currents that do not elicit unpleasant side-effects can help overcome visual loss after stroke. Here, we show that visual processing in neurologically healthy individuals can also benefit from galvanic vestibular stimulation. Participants first learnt the names of eight unfamiliar faces and then after a short delay, answered questions from memory about how pairs of these faces differed. Mean correct reaction times were significantly shorter when sub-sensory, noise-enhanced anodal stimulation was administered to the left mastoid, compared to when no stimulation was administered at all. This advantage occurred with no loss in response accuracy, and raises the possibility that the procedure may constitute a more general form of cognitive enhancement.

Four cases of acoustic neuromas with normal hearing.

PubMed

Valente, M; Peterein, J; Goebel, J; Neely, J G

1995-05-01

In 95 percent of the cases, patients with acoustic neuromas will have some magnitude of hearing loss in the affected ear. This paper reports on four patients who had acoustic neuromas and normal hearing. Results from the case history, audiometric evaluation, auditory brainstem response (ABR), electroneurography (ENOG), and vestibular evaluation are reported for each patient. For all patients, the presence of unilateral tinnitus was the most common complaint. Audiologically, elevated or absent acoustic reflex thresholds and abnormal ABR findings were the most powerful diagnostic tools.

Roll-Tilt Perception Using a Somatosensory Bar Task

NASA Technical Reports Server (NTRS)

Black, F. O.; Wade, S. W.; Arshi, A.

1999-01-01

Visual estimates of roll-tilt perception during static roll-tilt are confounded by an offset due to the ocular counterroll that simultaneously occurs. An alternative, non-visual ('somatosensory') measure of roll-tilt perception was developed which is not contaminated by this offset. The aims of this study were to determine: 1) inter-subject variability of somatosensory settings across test session in normal subjects and patients with unilateral or bilateral vestibular loss and 2) intra-subject variability of settings across test session in normal subjects.

A CMOS Neural Interface for a Multichannel Vestibular Prosthesis

PubMed Central

Hageman, Kristin N.; Kalayjian, Zaven K.; Tejada, Francisco; Chiang, Bryce; Rahman, Mehdi A.; Fridman, Gene Y.; Dai, Chenkai; Pouliquen, Philippe O.; Georgiou, Julio; Della Santina, Charles C.; Andreou, Andreas G.

2015-01-01

We present a high-voltage CMOS neural-interface chip for a multichannel vestibular prosthesis (MVP) that measures head motion and modulates vestibular nerve activity to restore vision- and posture-stabilizing reflexes. This application specific integrated circuit neural interface (ASIC-NI) chip was designed to work with a commercially available microcontroller, which controls the ASIC-NI via a fast parallel interface to deliver biphasic stimulation pulses with 9-bit programmable current amplitude via 16 stimulation channels. The chip was fabricated in the ONSemi C5 0.5 micron, high-voltage CMOS process and can accommodate compliance voltages up to 12 V, stimulating vestibular nerve branches using biphasic current pulses up to 1.45 ± 0.06 mA with durations as short as 10 µs/phase. The ASIC-NI includes a dedicated digital-to-analog converter for each channel, enabling it to perform complex multipolar stimulation. The ASIC-NI replaces discrete components that cover nearly half of the 2nd generation MVP (MVP2) printed circuit board, reducing the MVP system size by 48% and power consumption by 17%. Physiological tests of the ASIC-based MVP system (MVP2A) in a rhesus monkey produced reflexive eye movement responses to prosthetic stimulation similar to those observed when using the MVP2. Sinusoidal modulation of stimulus pulse rate from 68–130 pulses per second at frequencies from 0.1 to 5 Hz elicited appropriately-directed slow phase eye velocities ranging in amplitude from 1.9–16.7°/s for the MVP2 and 2.0–14.2°/s for the MVP2A. The eye velocities evoked by MVP2 and MVP2A showed no significant difference (t-test, p = 0.034), suggesting that the MVP2A achieves performance at least as good as the larger MVP2. PMID:25974945

Firing behavior of vestibular neurons during active and passive head movements: vestibulo-spinal and other non-eye-movement related neurons

NASA Technical Reports Server (NTRS)

McCrea, R. A.; Gdowski, G. T.; Boyle, R.; Belton, T.; Peterson, B. W. (Principal Investigator)

1999-01-01

The firing behavior of 51 non-eye movement related central vestibular neurons that were sensitive to passive head rotation in the plane of the horizontal semicircular canal was studied in three squirrel monkeys whose heads were free to move in the horizontal plane. Unit sensitivity to active head movements during spontaneous gaze saccades was compared with sensitivity to passive head rotation. Most units (29/35 tested) were activated at monosynaptic latencies following electrical stimulation of the ipsilateral vestibular nerve. Nine were vestibulo-spinal units that were antidromically activated following electrical stimulation of the ventromedial funiculi of the spinal cord at C1. All of the units were less sensitive to active head movements than to passive whole body rotation. In the majority of cells (37/51, 73%), including all nine identified vestibulo-spinal units, the vestibular signals related to active head movements were canceled. The remaining units (n = 14, 27%) were sensitive to active head movements, but their responses were attenuated by 20-75%. Most units were nearly as sensitive to passive head-on-trunk rotation as they were to whole body rotation; this suggests that vestibular signals related to active head movements were cancelled primarily by subtraction of a head movement efference copy signal. The sensitivity of most units to passive whole body rotation was unchanged during gaze saccades. A fundamental feature of sensory processing is the ability to distinguish between self-generated and externally induced sensory events. Our observations suggest that the distinction is made at an early stage of processing in the vestibular system.

Vestibular schwannoma management: Part II. Failed radiosurgery and the role of delayed microsurgery.

PubMed

Pollock, Bruce E; Lunsford, L Dade; Kondziolka, Douglas; Sekula, Raymond; Subach, Brian R; Foote, Robert L; Flickinger, John C

2013-12-01

The indications, operative findings, and outcomes of vestibular schwannoma microsurgery are controversial when it is performed after stereotactic radiosurgery. To address these issues, the authors reviewed the experience at two academic medical centers. During a 10-year interval, 452 patients with unilateral vestibular schwannomas underwent gamma knife radiosurgery. Thirteen patients (2.9%) underwent delayed microsurgery at a median of 27 months (range 7–72 months) after they had undergone radiosurgery. Six of the 13 patients had undergone one or more microsurgical procedures before they underwent radiosurgery. The indications for surgery were tumor enlargement with stable symptoms in five patients, tumor enlargement with new or increased symptoms in five patients, and increased symptoms without evidence of tumor growth in three patients. Gross-total resection was achieved in seven patients and near-gross-total resection in four patients. The surgery was described as more difficult than that typically performed for schwannoma in eight patients, no different in four patients, and easier in one patient. At the last follow-up evaluation, three patients had normal or near-normal facial function, three patients had moderate facial dysfunction, and seven had facial palsies. Three patients were incapable of caring for themselves, and one patient died of progression of a malignant triton tumor. Failed radiosurgery in cases of vestibular schwannoma was rare. No clear relationship was demonstrated between the use of radiosurgery and the subsequent ease or difficulty of delayed microsurgery. Because some patients have temporary enlargement of their tumor after radiosurgery, the need for surgical resection after radiosurgery should be reviewed with the neurosurgeon who performed the radiosurgery and should be delayed until sustained tumor growth is confirmed. A subtotal tumor resection should be considered for patients who require surgical resection of their tumor after vestibular schwannoma radiosurgery.

Bilateral Vestibular Deficiency: Quality of Life and Economic Implications.

PubMed

Sun, Daniel Q; Ward, Bryan K; Semenov, Yevgeniy R; Carey, John P; Della Santina, Charles C

2014-06-01

Bilateral vestibular deficiency (BVD) causes chronic imbalance and unsteady vision and greatly increases the risk of falls; however, its effects on quality of life and economic impact are not well defined. To quantify disease-specific and health-related quality of life, health care utilization, and economic impact on individuals with BVD in comparison with those with unilateral vestibular deficiency (UVD). Cross-sectional survey study of patients with BVD or UVD and healthy controls at an academic medical center. Vestibular dysfunction was diagnosed by means of caloric nystagmography. Survey questionnaire. Health status was measured using the Dizziness Handicap Index (DHI) and Health Utility Index Mark 3 (HUI3). Economic burden was estimated using participant responses to questions on disease-specific health care utilization and lost productivity. Fifteen patients with BVD, 22 with UVD, and 23 healthy controls participated. In comparison with patients with UVD and controls, patients with BVD had significantly worse DHI (P < .001) and HUI3 scores. Statistically significant between-group differences were observed for overall HUI3 score (P < .001) and for specific attributes including vision, hearing, ambulation, emotion, and pain (P < .001 for all). Generalized linear model analysis of clinical variables associated with HUI3 scores after adjustment for other variables (including sex, race, education, age, and frequency of dizziness-related outpatient clinic visits) showed that the presence of UVD (P < .001) or BVD (P < .001), increased dizziness-related emergency room visits (P = .002), and increased dizziness-related missed work days (P < .001) were independently associated with worse HUI3 scores. Patients with BVD and UVD incurred estimated mean (range) annual economic burdens of $13,019 ($0-$48,830) and $3531 ($0-$48,442) per patient, respectively. Bilateral vestibular deficiency significantly decreases quality of life and imposes substantial economic burdens on individuals and society. These results underscore the limits of adaptation and compensation in BVD. Furthermore, they quantify the potential benefits of prosthetic restoration of vestibular function both to these individuals and to society.

Bell’s palsy: data from a study of 70 cases

PubMed Central

Cirpaciu, D; Goanta, CM

2014-01-01

Bell’s palsy is a condition that affects the facial nerve, which is one of the twelve cranial nerves. Its main function is to control all the muscles of the facial expression. It is a unilateral, acute, partial or complete paralysis of the facial nerve. Bell's palsy remains the most common cause of facial nerve paralysis, more often encountered in females aged 17 to 30 years, recurrent in many cases and with poor associations with other pathologic conditions. In modern literature, the suspected etiology could be due to the reactivation of the latent herpes viral infections in the geniculate ganglia, and their subsequent migration to the facial nerve but, favorable outcome by using vasodilators, neurotrophic and corticosteroid therapy was recorded. PMID:25870668

Bell's palsy: data from a study of 70 cases.

PubMed

Cirpaciu, D; Goanta, C M

2014-01-01

Bell's palsy is a condition that affects the facial nerve, which is one of the twelve cranial nerves. Its main function is to control all the muscles of the facial expression. It is a unilateral, acute, partial or complete paralysis of the facial nerve. Bell's palsy remains the most common cause of facial nerve paralysis, more often encountered in females aged 17 to 30 years, recurrent in many cases and with poor associations with other pathologic conditions. In modern literature, the suspected etiology could be due to the reactivation of the latent herpes viral infections in the geniculate ganglia, and their subsequent migration to the facial nerve but, favorable outcome by using vasodilators, neurotrophic and corticosteroid therapy was recorded.

Differences in individual susceptibility affect the development of trigeminal neuralgia☆

PubMed Central

Duransoy, Yusuf Kurtuluş; Mete, Mesut; Akçay, Emrah; Selçuki, Mehmet

2013-01-01

Trigeminal neuralgia is a syndrome due to dysfunctional hyperactivity of the trigeminal nerve, and is characterized by a sudden, usually unilateral, recurrent lancinating pain arising from one or more divisions of the nerve. The most accepted pathogenetic mechanism for trigeminal neuralgia is compression of the nerve at its dorsal root entry zone or in its distal course. In this paper, we report four cases with trigeminal neuralgia due to an unknown mechanism after an intracranial intervention. The onset of trigeminal neuralgia after surgical interventions that are unrelated to the trigeminal nerve suggests that in patients with greater individual susceptibility, nerve contact with the vascular structure due to postoperative pressure and changes in cerebrospinal fluid flow may cause the onset of pain. PMID:25206428

Asymmetrical perception of body rotation after unilateral injury to human vestibular cortex.

PubMed

Philbeck, John W; Behrmann, Marlene; Biega, Tim; Levy, Lucien

2006-01-01

Vestibular information plays a key role in many perceptual and cognitive functions, but surprisingly little is known about how vestibular signals are processed at the cortical level in humans. To address this issue, we tested the ability of two patients, with damage to key components of the vestibular network in either the left or right hemisphere, to perceive passive whole-body rotations (25-125 degrees) about the yaw axis. In both patients, the posterior insula, hippocampus, putamen, and thalamus were extensively damaged. The patients' responses were compared with those of nine age- and sex-matched neurologically intact participants. The body rotations were conducted without vision and the peak angular velocities ranged from 40 degrees to 90 degrees per second. Perceived rotation was assessed by open-loop manual pointing. The right hemisphere patient exhibited poor sensitivity for body rotations toward the contralesional (left) hemispace and generally underestimated the rotations. By contrast, his judgments of rotations toward the ipsilesional (right) hemispace greatly overestimated the physical rotation by 50-70 degrees for all tested magnitudes. The left hemisphere patient's responses were more appropriately scaled for both rotation directions, falling in the low-normal range. These findings suggest that there is some degree of hemispheric specialization in the cortical processing of dynamic head rotations in the yaw plane. In this view, right hemisphere structures play a dominant role, processing rotations in both directions, while left hemisphere structures process rotations only toward the contralesional hemispace.

[Vertigo and dizziness in the emergency room].

PubMed

Zwergal, A; Möhwald, K; Dieterich, M

2017-06-01

Vertigo and dizziness are among the most common chief complaints in the emergency department. Etiologies can be categorized into three subgroups: neurootological (vestibular), medical (especially cardiovascular, metabolic), and psychiatric disorders. The diagnostic approach in the emergency department is based on a systematic analysis of case history (type, time course of symptoms, modulating factors, associated symptoms), clinical examination of the vestibular, ocular motor, and cerebellar systems (head impulse test, nystagmus, skew deviation, positioning maneuver, test of gait and stance), as well as a basal monitoring (vital signs, 12-lead ECG, blood tests). For differentiation of peripheral and central etiologies in acute vestibular syndrome, the HINTS exam (head impulse test, nystagmus, test of skew) and examination of smooth pursuit and saccades should be applied. Nonselective use of neuroimaging is not indicated due to a low diagnostic yield. Cranial imaging should be done in the following constellations: (1) detection of focal neurological or central ocular motor and vestibular signs on clinical exam, (2) acute abasia with only minor ocular motor signs, (3) presence of various cardiovascular risk factors, (4) headache of unknown quality as an accompanying symptom. Besides the symptomatic therapy of vertigo and dizziness with antiemetics or analgesics, further diagnostic differentiation is urgent to guide proper treatment. Examples are the acute therapy in cerebral ischemia, the execution of positioning maneuvers in benign paroxysmal positional vertigo, the use of corticosteroids in acute unilateral vestibulopathy, as well as the readjustment of metabolic homeostasis in medical disorders.

Unilateral Superior Laryngeal Nerve Lesion in an Animal Model of Dysphagia and Its Effect on Sucking and Swallowing

PubMed Central

Campbell-Malone, Regina; Holman, Shaina D.; Lukasik, Stacey L.; Fukuhara, Takako; Gierbolini-Norat, Estela M.; Thexton, Allan J.; German, Rebecca Z.

2013-01-01

We tested two hypotheses relating to the sensory deficit that follows a unilateral superior laryngeal nerve (SLN) lesion in an infant animal model. We hypothesized that it would result in (1) a higher incidence of aspiration and (2) temporal changes in sucking and swallowing. We ligated the right-side SLN in six 2–3-week-old female pigs. Using videofluoroscopy, we recorded swallows in the same pre- and post-lesion infant pigs. We analyzed the incidence of aspiration and the duration and latency of suck and swallow cycles. After unilateral SLN lesioning, the incidence of silent aspiration during swallowing increased from 0.7 to 41.5 %. The durations of the suck containing the swallow, the suck immediately following the swallow, and the swallow itself were significantly longer in the post-lesion swallows, although the suck prior to the swallow was not different. The interval between the start of the suck containing a swallow and the subsequent epiglottal movement was longer in the post-lesion swallows. The number of sucks between swallows was significantly greater in post-lesion swallows compared to pre-lesion swallows. Unilateral SLN lesion increased the incidence of aspiration and changed the temporal relationships between sucking and swallowing. The longer transit time and the temporal coordinative dysfunction between suck and swallow cycles may contribute to aspiration. These results suggest that swallow dysfunction and silent aspiration are common and potentially overlooked sequelae of unilateral SLN injury. This validated animal model of aspiration has the potential for further dysphagia studies. PMID:23417250

Unilateral nasal pain with migraine features.

PubMed

Alvarez, Mónica; Montojo, Teresa; de la Casa, Beatriz; Vela, Lydia; Pareja, Juan A

2013-09-01

Migraine attacks exclusively felt in the face are very rare, the pain involving the territories supplied by the second and third branches of the trigeminal nerve. Two patients suffering from heminasal pain attacks accompanied with typical migrainous features and responsive to oral or intranasal triptans - but not to intranasal lidocaine or oxymetazoline. In one patient, the attacks could be precipitated upon slight touching on the tip of the nose, in the other attacks were preceded by the nasal sensation typically heralding sneezing. Migraine pain mostly develops within the innervation territory of the first branch of the trigeminal nerve, which includes the nose. Therefore, episodes of unilateral nasal pain with migrainous features could be considered a migraine with unusual topography (nasal migraine). Painful nasal attacks occasionally preceded by stimulation of trigeminal afferents in the nose, could be conceived of as migraine-tic syndrome.

Abducens Nerve in Patients with Type 3 Duane’s Retraction Syndrome

PubMed Central

Hwang, Jeong-Min

2016-01-01

Background We have previously reported that the presence of the abducens nerve was variable in patients with type 3 Duane’s retraction syndrome (DRS), being present in 2 of 5 eyes (40%) and absent in 3 (60%) on magnetic resonance imaging (MRI). The previous study included only 5 eyes with unilateral DRS type 3. Objectives To supplement existing scarce pathologic information by evaluating the presence of the abducens nerve using high resolution thin-section MRI system in a larger number of patients with DRS type 3, thus to provide further insight into the pathogenesis of DRS. Data Extraction A retrospective review of medical records on ophthalmologic examination and high resolution thin-section MRI at the brainstem level and orbit was performed. A total of 31 patients who showed the typical signs of DRS type 3, including abduction and adduction deficit, globe retraction, narrowing of fissure on adduction and upshoot and/or downshoot, were included. The abducens nerve and any other extraocular muscle abnormalities discovered by MRI were noted. Results DRS was unilateral in 26 patients (84%) and bilateral in 5 patients (16%). Two out of 5 bilateral patients had DRS type 3 in the right eye and DRS type 1 in the left eye. Of the 34 affected orbits with DRS type 3 in 31 patients, the abducens nerve was absent or hypoplastic in 31 eyes (91%) and present in 3 eyes (9%). Patients with a present abducens nerve showed more limitation in adduction compared to patients with an absent abducens nerve (P = 0.030). Conclusions The abducens nerve is absent or hypoplastic in 91% of DRS type 3. Patients with a present abducens nerve showed more prominent limitation of adduction. As DRS type 3 partly share the same pathophysiology with type 1 and 2 DRS, the classification of DRS may have to be revised according to MRI findings. PMID:27352171

Sacral nerve stimulation enhances epithelial barrier of the rectum: results from a porcine model.

PubMed

Meurette, G; Blanchard, C; Duchalais-Dassonneville, E; Coquenlorge, S; Aubert, P; Wong, M; Lehur, P-A; Neunlist, M

2012-03-01

The mechanism of action of sacral nerve stimulation (SNS) remains largely elusive. The aims of this study were to develop a clinically relevant animal model for percutaneous SNS and to describe its effect on the epithelial barrier of the rectum. Under general anesthesia and after percutaneous electrode placement for S3 nerve root stimulation, six pigs underwent unilateral stimulation and six bilateral stimulation. Animals were stimulated for 3 h using an external pulse generator (1-2.5 V; 14 Hz; 210 μs). Six animals underwent electrode implantation without stimulation and served as controls. Full-thickness rectal biopsies were performed prior to and after stimulation. Paracellular permeability was evaluated by measuring sulfonic acid flux across the rectal mucosa in Ussing chambers. Histological assessment of mucosal thickness, epithelial desquamation, and mucus expression were performed. Percutaneous stimulation resulted in successful anal contractions whose amplitude and uniformity was enhanced following bilateral compared with unilateral stimulation. In controls, paracellular permeability significantly increased during the stimulation period whereas it remained unchanged following unilateral stimulation. In contrast, permeability was significantly reduced by bilateral stimulation. This effect was associated with a concomitant reduction in mucosal thickness and a trend toward increased amount of mucus on surface epithelium compared with controls. The development of a porcine model of percutaneous SNS revealed the ability of neuromodulation to reinforce rectal epithelial barrier. Furthermore, our results suggest that SNS could be used for treatment of gastrointestinal pathologies with reduced rectal mucosal barrier functions. © 2012 Blackwell Publishing Ltd.

Bilateral widespread mechanical pain sensitivity in carpal tunnel syndrome: evidence of central processing in unilateral neuropathy.

PubMed

Fernández-de-las-Peñas, César; de la Llave-Rincón, Ana Isabel; Fernández-Carnero, Josué; Cuadrado, María Luz; Arendt-Nielsen, Lars; Pareja, Juan A

2009-06-01

The aim of this study was to investigate whether bilateral widespread pressure hypersensitivity exists in patients with unilateral carpal tunnel syndrome. A total of 20 females with carpal tunnel syndrome (aged 22-60 years), and 20 healthy matched females (aged 21-60 years old) were recruited. Pressure pain thresholds were assessed bilaterally over median, ulnar, and radial nerve trunks, the C5-C6 zygapophyseal joint, the carpal tunnel and the tibialis anterior muscle in a blinded design. The results showed that pressure pain threshold levels were significantly decreased bilaterally over the median, ulnar, and radial nerve trunks, the carpal tunnel, the C5-C6 zygapophyseal joint, and the tibialis anterior muscle in patients with unilateral carpal tunnel syndrome as compared to healthy controls (all, P < 0.001). Pressure pain threshold was negatively correlated to both hand pain intensity and duration of symptoms (all, P < 0.001). Our findings revealed bilateral widespread pressure hypersensitivity in subjects with carpal tunnel syndrome, which suggest that widespread central sensitization is involved in patients with unilateral carpal tunnel syndrome. The generalized decrease in pressure pain thresholds associated with pain intensity and duration of symptoms supports a role of the peripheral drive to initiate and maintain central sensitization. Nevertheless, both central and peripheral sensitization mechanisms are probably involved at the same time in carpal tunnel syndrome.

Hearing Preservation after Low-dose Gamma Knife Radiosurgery of Vestibular Schwannomas

PubMed Central

HORIBA, Ayako; HAYASHI, Motohiro; CHERNOV, Mikhail; KAWAMATA, Takakazu; OKADA, Yoshikazu

2016-01-01

The objective of the retrospective study was to evaluate the factors associated with hearing preservation after low-dose Gamma Knife radiosurgery (GKS) of vestibular schwannomas performed according to the modern standards. From January 2005 to September 2010, 141 consecutive patients underwent such treatment in Tokyo Women’s Medical University. Mean marginal dose was 11.9 Gy (range, 11–12 Gy). The doses for the brain stem, cranial nerves (V, VII, and VIII), and cochlea were kept below 14 Gy, 12 Gy, and 4 Gy, respectively. Out of the total cohort, 102 cases with at least 24 months follow-up were analyzed. Within the median follow-up of 56 months (range, 24–99 months) the crude tumor growth control was 92% (94 cases), whereas its actuarial rate at 5 years was 93%. Out of 49 patients with serviceable hearing on the side of the tumor before GKS, 28 (57%) demonstrated its preservation at the time of the last follow-up. No one evaluated factor, namely Gardner-Robertson hearing class before irradiation, Koos tumor stage, extension of the intrameatal part of the neoplasm up to fundus, nerve of tumor origin, presence of cystic changes in the neoplasm, and cochlea dose demonstrated statistically significant association with preservation of the serviceable hearing after radiosurgery. In conclusion, GKS of vestibular schwannomas performed according to the modern standards of treatment permits to preserve serviceable hearing on the side of the tumor in more than half of the patients. The actual causes of hearing deterioration after radiosurgery remain unclear. PMID:26876903

Vestibular control of sympathetic activity. An otolith-sympathetic reflex in humans

NASA Technical Reports Server (NTRS)

Kaufmann, H.; Biaggioni, I.; Voustianiouk, A.; Diedrich, A.; Costa, F.; Clarke, R.; Gizzi, M.; Raphan, T.; Cohen, B.

2002-01-01

It has been proposed that a vestibular reflex originating in the otolith organs and other body graviceptors modulates sympathetic activity during changes in posture with regard to gravity. To test this hypothesis, we selectively stimulated otolith and body graviceptors sinusoidally along different head axes in the coronal plane with off-vertical axis rotation (OVAR) and recorded sympathetic efferent activity in the peroneal nerve (muscle sympathetic nerve activity, MSNA), blood pressure, heart rate, and respiratory rate. All parameters were entrained during OVAR at the frequency of rotation, with MSNA increasing in nose-up positions during forward linear acceleration and decreasing when nose-down. MSNA was correlated closely with blood pressure when subjects were within +/-90 degrees of nose-down positions with a delay of 1.4 s, the normal latency of baroreflex-driven changes in MSNA. Thus, in the nose-down position, MSNA was probably driven by baroreflex afferents. In contrast, when subjects were within +/-45 degrees of the nose-up position, i.e., when positive linear acceleration was maximal along the naso-ocipital axis, MSNA was closely related to gravitational acceleration at a latency of 0.4 s. This delay is too short for MSNA changes to be mediated by the baroreflex, but it is compatible with the delay of a response originating in the vestibular system. We postulate that a vestibulosympathetic reflex, probably originating mainly in the otolith organs, contributes to blood pressure maintenance during forward linear acceleration. Because of its short latency, this reflex may be one of the earliest mechanisms to sustain blood pressure upon standing.

Vestibular control of sympathetic activity. An otolith-sympathetic reflex in humans.

PubMed

Kaufmann, H; Biaggioni, I; Voustianiouk, A; Diedrich, A; Costa, F; Clarke, R; Gizzi, M; Raphan, T; Cohen, B

2002-04-01

It has been proposed that a vestibular reflex originating in the otolith organs and other body graviceptors modulates sympathetic activity during changes in posture with regard to gravity. To test this hypothesis, we selectively stimulated otolith and body graviceptors sinusoidally along different head axes in the coronal plane with off-vertical axis rotation (OVAR) and recorded sympathetic efferent activity in the peroneal nerve (muscle sympathetic nerve activity, MSNA), blood pressure, heart rate, and respiratory rate. All parameters were entrained during OVAR at the frequency of rotation, with MSNA increasing in nose-up positions during forward linear acceleration and decreasing when nose-down. MSNA was correlated closely with blood pressure when subjects were within +/-90 degrees of nose-down positions with a delay of 1.4 s, the normal latency of baroreflex-driven changes in MSNA. Thus, in the nose-down position, MSNA was probably driven by baroreflex afferents. In contrast, when subjects were within +/-45 degrees of the nose-up position, i.e., when positive linear acceleration was maximal along the naso-ocipital axis, MSNA was closely related to gravitational acceleration at a latency of 0.4 s. This delay is too short for MSNA changes to be mediated by the baroreflex, but it is compatible with the delay of a response originating in the vestibular system. We postulate that a vestibulosympathetic reflex, probably originating mainly in the otolith organs, contributes to blood pressure maintenance during forward linear acceleration. Because of its short latency, this reflex may be one of the earliest mechanisms to sustain blood pressure upon standing.

Acoustic Overexposure Increases the Expression of VGLUT-2 Mediated Projections from the Lateral Vestibular Nucleus to the Dorsal Cochlear Nucleus

PubMed Central

Barker, Matthew; Solinski, Hans Jürgen; Hashimoto, Haruka; Tagoe, Thomas; Pilati, Nadia; Hamann, Martine

2012-01-01

The dorsal cochlear nucleus (DCN) is a first relay of the central auditory system as well as a site for integration of multimodal information. Vesicular glutamate transporters VGLUT-1 and VGLUT-2 selectively package glutamate into synaptic vesicles and are found to have different patterns of organization in the DCN. Whereas auditory nerve fibers predominantly co-label with VGLUT-1, somatosensory inputs predominantly co-label with VGLUT-2. Here, we used retrograde and anterograde transport of fluorescent conjugated dextran amine (DA) to demonstrate that the lateral vestibular nucleus (LVN) exhibits ipsilateral projections to both fusiform and deep layers of the rat DCN. Stimulating the LVN induced glutamatergic synaptic currents in fusiform cells and granule cell interneurones. We combined the dextran amine neuronal tracing method with immunohistochemistry and showed that labeled projections from the LVN are co-labeled with VGLUT-2 by contrast to VGLUT-1. Wistar rats were exposed to a loud single tone (15 kHz, 110 dB SPL) for 6 hours. Five days after acoustic overexposure, the level of expression of VGLUT-1 in the DCN was decreased whereas the level of expression of VGLUT-2 in the DCN was increased including terminals originating from the LVN. VGLUT-2 mediated projections from the LVN to the DCN are likely to play a role in the head position in response to sound. Amplification of VGLUT-2 expression after acoustic overexposure could be a compensatory mechanism from vestibular inputs in response to hearing loss and to a decrease of VGLUT-1 expression from auditory nerve fibers. PMID:22570693

Chicken (Gallus domesticus) inner ear afferents

NASA Technical Reports Server (NTRS)

Hara, H.; Chen, X.; Hartsfield, J. F.; Hara, J.; Martin, D.; Fermin, C. D.

1998-01-01

Neurons from the vestibular (VG) and the statoacoustic (SAG) ganglion of the chick (Gallus domesticus) were evaluated histologically and morphometrically. Embryos at stages 34 (E8 days), 39 (E13 days) and 44 (E18 days) were sacrificed and temporal bones microdissected. Specimens were embedded in JB-4 methacrylate plastic, and stained with a mixture of 0.2% toluidine blue (TB) and 0.1% basic Fuschin in 25% ethanol or with a mixture of 2% TB and 1% paraphenylenediamine (PDA) for axon and myelin measurement study. Images of the VIIIth nerve were produced by a V150 (R) color imaging system and the contour of 200-300 neuronal bodies (perikarya) was traced directly on a video screen with a mouse in real time. The cross-sectional area of VG perikarya was 67.29 micrometers2 at stage 34 (E8), 128.46 micrometers2 at stage 39 (E13) and 275.85 micrometers2 at stage 44 (E18). The cross-sectional area of SAG perikarya was 62.44 micrometers2 at stage 34 (E8), 102.05 micrometers2 at stage 39 (E13) and 165.02 micrometers2 at stage 44 (E18). A significant cross-sectional area increase of the VG perikarya between stage 39 (E13) and stage 44 (E18) was determined. We randomly measured the cross-sectional area of myelin and axoplasm of hatchling afferent nerves, and found a correspondence between axoplasmic and myelin cross-sectional area in the utricular, saccular and semicircular canal nerve branches of the nerve. The results suggest that the period between stage 34 (E8) and 39 (E13) is a critical period for afferent neuronal development. Physiological and behavioral vestibular properties of developing and maturing hatchlings may change accordingly. The results compliment previous work by other investigators and provide valuable anatomical measures useful to correlate physiological data obtained from stimulation of the whole nerve or its parts.

Transtympanic Facial Nerve Paralysis: A Review of the Literature

PubMed Central

Schaefer, Nathan; O’Donohue, Peter; French, Heath; Griffin, Aaron; Gochee, Peter

2015-01-01

Summary: Facial nerve paralysis because of penetrating trauma through the external auditory canal is extremely rare, with a paucity of published literature. The objective of this study is to review the literature on transtympanic facial nerve paralysis and increase physician awareness of this uncommon injury through discussion of its clinical presentation, management and prognosis. We also aim to improve patient outcomes in those that have sustained this type of injury by suggesting an optimal management plan. In this case report, we present the case of a 46-year-old white woman who sustained a unilateral facial nerve paresis because of a garfish penetrating her tympanic membrane and causing direct damage to the tympanic portion of her facial nerve. On follow-up after 12 months, her facial nerve function has largely returned to normal. Transtympanic facial nerve paralysis is a rare injury but can have a favorable prognosis if managed effectively. PMID:26090278

Cranial nerve injury after Le Fort I osteotomy.

PubMed

Kim, J-W; Chin, B-R; Park, H-S; Lee, S-H; Kwon, T-G

2011-03-01

A Le Fort I osteotomy is widely used to correct dentofacial deformity because it is a safe and reliable surgical method. Although rare, various complications have been reported in relation to pterygomaxillary separation. Cranial nerve damage is one of the serious complications that can occur after Le Fort I osteotomy. In this report, a 19-year-old man with unilateral cleft lip and palate underwent surgery to correct maxillary hypoplasia, asymmetry and mandibular prognathism. After the Le Fort I maxillary osteotomy, the patient showed multiple cranial nerve damage; an impairment of outward movement of the eye (abducens nerve), decreased vision (optic nerve), and paraesthesia of the frontal and upper cheek area (ophthalmic and maxillary nerve). The damage to the cranial nerve was related to an unexpected sphenoid bone fracture and subsequent trauma in the cavernous sinus during the pterygomaxillary osteotomy. Copyright © 2010 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

A case of bilateral lower cranial nerve palsies after base of skull trauma with complex management issues: case report and review of the literature.

PubMed

Lehn, Alexander Christoph; Lettieri, Jennie; Grimley, Rohan

2012-05-01

Fractures of the skull base can cause lower cranial nerve palsies because of involvement of the nerves as they traverse the skull. A variety of syndromes have been described, often involving multiple nerves. These are most commonly unilateral, and only a handful of cases of bilateral cranial nerve involvement have been reported. We describe a 64-year-old man with occipital condylar fracture complicated by bilateral palsies of IX and X nerves associated with dramatic physiological derangement causing severe management challenges. Apart from debilitating postural hypotension, he developed dysphagia, severe gastrointestinal dysmotility, issues with airway protection as well as airway obstruction, increased oropharyngeal secretions and variable respiratory control. This is the first report of a patient with traumatic bilateral cranial nerve IX and X nerve palsies. This detailed report and the summary of all 6 previous case reports of traumatic bilateral lower cranial nerve palsies illustrate clinical features, treatment strategies, and outcomes of these rare events.

Superior Canal Dehiscence Syndrome Affecting 3 Families.

PubMed

Heidenreich, Katherine D; Kileny, Paul R; Ahmed, Sameer; El-Kashlan, Hussam K; Melendez, Tori L; Basura, Gregory J; Lesperance, Marci M

2017-07-01

Superior canal dehiscence syndrome (SCDS) is an increasingly recognized cause of hearing loss and vestibular symptoms, but the etiology of this condition remains unknown. To describe 7 cases of SCDS across 3 families. This retrospective case series included 7 patients from 3 different families treated at a neurotology clinic at a tertiary academic medical center from 2010 to 2014. Patients were referred by other otolaryngologists or were self-referred. Each patient demonstrated unilateral or bilateral SCDS or near dehiscence. Clinical evaluation involved body mass index calculation, audiometry, cervical vestibular evoked myogenic potential testing, electrocochleography, and multiplanar computed tomographic (CT) scan of the temporal bones. Zygosity testing was performed on twin siblings. The diagnosis of SCDS was made if bone was absent over the superior semicircular canal on 2 consecutive CT images, in addition to 1 physiologic sign consistent with labyrinthine dehiscence. Near dehiscence was defined as absent bone on only 1 CT image but with symptoms and at least 1 physiologic sign of labyrinthine dehiscence. A total of 7 patients (5 female and 2 male; age range, 8-49 years) from 3 families underwent evaluation. Family A consisted of 3 adult first-degree relatives, of whom 2 were diagnosed with SCDS and 1 with near dehiscence. Family B included a mother and her child, both of whom were diagnosed with unilateral SCDS. Family C consisted of adult monozygotic twins, each of whom was diagnosed with unilateral SCDS. For all cases, dehiscence was located at the arcuate eminence. Obesity alone did not explain the occurrence of SCDS because 5 of the 7 cases had a body mass index (calculated as weight in kilograms divided by height in meters squared) less than 30.0. Superior canal dehiscence syndrome is a rare, often unrecognized condition. This report of 3 multiplex families with SCDS provides evidence in support of a potential genetic contribution to the etiology. Symptomatic first-degree relatives of patients diagnosed with SCDS should be offered evaluation to improve detection of this disorder.

Hyperglycemia and diabetes mellitus are related to vestibular organs dysfunction: truth or suggestion? A literature review.

PubMed

Gioacchini, Federico Maria; Albera, Roberto; Re, Massimo; Scarpa, Alfonso; Cassandro, Claudia; Cassandro, Ettore

2018-06-23

Diabetes mellitus is an independent risk factor for falling, particularly in the elderly. Due to chronic hyperglycemia and hyperinsulinemia patients with diabetes mellitus may have neurological deficits as peripheral neuropathy that is a debilitating micro-vascular complication affecting the proximal and distal peripheral sensory and motor nerves. Sensory neuropathy is prominent and represents the chief contributor to postural instability in diabetic subjects. Diabetic retinopathy is another complication consequent to a breakdown of the inner blood-retinal barrier with accumulation of extracellular fluids in the macula and growth of new vessels causing retinal detachment. Together peripheral neuropathy and retinopathy contribute to increase the risk of falls in diabetic patients, but a certain vestibular organs impairment should not be underestimated. Nevertheless, the exact mechanism and localization of peripheral vestibular damage consequent to chronic hyperglycemia and hyperinsulinemia are currently not still understood. Moreover it is not defined the possible role of these two blood conditions in worsening the prognosis of typical vestibular pathologies like "benign paroxysmal positional vertigo" and "Meniere disease". The aim of this review was to retrieve all studies investigating about the balance system alterations in patients suffering of diabetes. A search thorough Ovid MEDLINE was performed to enroll all eligible articles. Fourteen studies comprising a total of 1364 patients were included and analyzed in detail. On the basis of data reported in our review it appears plausible to hypothesize a direct connection among chronic hyperglycemic/hyperinsulinemic damage and peripheral vestibular organ dysfunction.

Relationship Between Laryngeal Electromyography and Video Laryngostroboscopy in Vocal Fold Paralysis.

PubMed

Maamary, Joel A; Cole, Ian; Darveniza, Paul; Pemberton, Cecilia; Brake, Helen Mary; Tisch, Stephen

2017-09-01

The objective of this study was to better define the relationship of laryngeal electromyography and video laryngostroboscopy in the diagnosis of vocal fold paralysis. Retrospective diagnostic cohort study with cross-sectional data analysis METHODS: Data were obtained from 57 patients with unilateral vocal fold paralysis who attended a large tertiary voice referral center. Electromyographic findings were classified according to recurrent laryngeal nerve, superior laryngeal nerve, and high vagal/combined lesions. Video laryngostroboscopy recordings were classified according to the position of the immobile fold into median, paramedian, lateral, and a foreshortened/hooded vocal fold. The position of the paralyzed vocal fold was then analyzed according to the lesion as determined by electromyography. The recurrent laryngeal nerve was affected in the majority of cases with left-sided lesions more common than right. Vocal fold position differed between recurrent laryngeal and combined vagal lesions. Recurrent laryngeal nerve lesions were more commonly associated with a laterally displaced immobile fold. No fold position was suggestive of a combined vagal lesion. The inter-rater reliability for determining fold position was high. Laryngeal electromyography is useful in diagnosing neuromuscular dysfunction of the larynx and best practice recommends its continued implementation along with laryngostroboscopy. While recurrent laryngeal nerve lesions are more likely to present with a lateral vocal fold, this does not occur in all cases. Such findings indicate that further unknown mechanisms contribute to fold position in unilateral paralysis. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Vestibulosympathetic reflex during mental stress

NASA Technical Reports Server (NTRS)

Carter, Jason R.; Ray, Chester A.; Cooke, William H.

2002-01-01

Increases in sympathetic neural activity occur independently with either vestibular or mental stimulation, but it is unknown whether sympathetic activation is additive or inhibitive when both stressors are combined. The purpose of the present study was to investigate the combined effects of vestibular and mental stimulation on sympathetic neural activation and arterial pressure in humans. Muscle sympathetic nerve activity (MSNA), arterial pressure, and heart rate were recorded in 10 healthy volunteers in the prone position during 1) head-down rotation (HDR), 2) mental stress (MS; using arithmetic), and 3) combined HDR and MS. HDR significantly (P < 0.05) increased MSNA (9 +/- 2 to 13 +/- 2 bursts/min). MS significantly increased MSNA (8 +/- 2 to 13 +/- 2 bursts/min) and mean arterial pressure (87 +/- 2 to 101 +/- 2 mmHg). Combined HDR and MS significantly increased MSNA (9 +/- 1 to 16 +/- 2 bursts/min) and mean arterial pressure (89 +/- 2 to 100 +/- 3 mmHg). Increases in MSNA (7 +/- 1 bursts/min) during the combination trial were not different from the algebraic sum of each trial performed alone (8 +/- 2 bursts/min). We conclude that the interaction for MSNA and arterial pressure is additive during combined vestibular and mental stimulation. Therefore, vestibular- and stress-mediated increases of MSNA appear to occur independently in humans.

Imaging anatomy of the vestibular and visual systems.

PubMed

Gunny, Roxana; Yousry, Tarek A

2007-02-01

This review will outline the imaging anatomy of the vestibular and visual pathways, using computed tomography and magnetic resonance imaging, with emphasis on the more recent developments in neuroimaging. Technical advances in computed tomography and magnetic resonance imaging, such as the advent of multislice computed tomography and newer magnetic resonance imaging techniques such as T2-weighted magnetic resonance cisternography, have improved the imaging of the vestibular and visual pathways, allowing better visualization of the end organs and peripheral nerves. Higher field strength magnetic resonance imaging is a promising tool, which has been used to evaluate and resolve fine anatomic detail in vitro, as in the labyrinth. Advanced magnetic resonance imaging techniques such as functional magnetic resonance imaging and diffusion tractography have been used to identify cortical areas of activation and associated white matter pathways, and show potential for the future identification of complex neuronal relays involved in integrating these pathways. The assessment of the various components of the vestibular and the visual systems has improved with more detailed research on the imaging anatomy of these systems, the advent of high field magnetic resonance scanners and multislice computerized tomography, and the wider use of specific techniques such as tractography which displays white matter tracts not directly accessible until now.

Anatomy, Physiology and Function of the Auditory System

NASA Astrophysics Data System (ADS)

Kollmeier, Birger

The human ear consists of the outer ear (pinna or concha, outer ear canal, tympanic membrane), the middle ear (middle ear cavity with the three ossicles malleus, incus and stapes) and the inner ear (cochlea which is connected to the three semicircular canals by the vestibule, which provides the sense of balance). The cochlea is connected to the brain stem via the eighth brain nerve, i.e. the vestibular cochlear nerve or nervus statoacusticus. Subsequently, the acoustical information is processed by the brain at various levels of the auditory system. An overview about the anatomy of the auditory system is provided by Figure 1.

Stereotactic radiotherapy of vestibular schwannoma : Hearing preservation, vestibular function, and local control following primary and salvage radiotherapy.

PubMed

Putz, Florian; Müller, Jan; Wimmer, Caterina; Goerig, Nicole; Knippen, Stefan; Iro, Heinrich; Grundtner, Philipp; Eyüpoglu, Ilker; Rössler, Karl; Semrau, Sabine; Fietkau, Rainer; Lettmaier, Sebastian

2017-03-01

The aim of this publication is to present long-term data on functional outcomes and tumor control in a cohort of 107 patients treated with stereotactic radiotherapy (RT) for vestibular schwannoma. Included were 107 patients with vestibular schwannoma (primary or recurrent following resection) treated with stereotactic RT (either fractioned or single-dose radiosurgery) between October 2002 and December 2013. Local control and functional outcomes were determined. Analysis of hearing preservation was limited to a subgroup of patients with complete audiometric data collected before treatment and during follow-up. Vestibular function test (FVT) results could be analyzed in a subset of patients and were compared to patient-reported dizziness. After a mean follow-up of 46.3 months, actuarial local control for the whole cohort was 100% after 2, 97.6% after 5, and 94.1% after 10 years. In patients with primary RT, serviceable hearing was preserved in 72%. Predictors for preservation of serviceable hearing in multivariate analysis were time of follow-up (odds ratio, OR = 0.93 per month; p = 0.021) and pre-RT tumor size (Koos stage I-IIa vs. IIb-IV; OR = 0.15; p = 0.031). Worsening of FVT results was recorded in 17.6% (N = 3). Profound discrepancy of patient-reported dizziness and FVT results was observed after RT. In patients with primary RT, worsening of facial nerve function occurred in 1.7% (N = 1). Stereotactic RT of vestibular schwannoma provides good functional outcomes and high control rates. Dependence of hearing preservation on time of follow-up and initial tumor stage has to be considered.

Herpes virus and Ménière's disease.

PubMed

Gartner, M; Bossart, W; Linder, T

2008-01-01

The main goal of this study was to examine the vestibular ganglia from patients with intractable classic Ménière's disease (MD) for the presence or absence of DNA from three neurotropic viruses herpes simplex virus 1 and 2 (HSV1, HSV2) and varicella zoster virus (VZV) and to investigate the hypothesis that MD is associated with virus reactivation within Scarpa's ganglion. Polymerase chain reaction (PCR) was performed with nested primer sets specific for viral genomic DNA of HSV1, HSV2 and VZV in biopsies of the ganglion scarpae of patients with MD who underwent vestibular neurectomy. Included were patients with MD classified as definite MD according to American Academy of Otolaryngology/Head and Neck Surgery criteria. The ganglion scarpae and ganglion geniculi harvested at autopsy from patients without history of MD or facial palsy served as control specimens. No viral DNA was detected in the vestibular ganglion of 7 patients with definite MD. In 34% of the vestibular ganglia of the control group we detected either HSV1 or VZV. Only one Scarpa's ganglion had both viruses present at the same time. Thirty-two out of 34 ganglia from the geniculate segment of the facial nerve contained either HSV1 and/or VZV genomic DNA. Eight specimens contained both viruses simultaneously. Altogether viral DNA was found in 94% of ganglia. Viral genomic DNA of HSV2 was not detected. Although HSV and VZV appear to be present in many ganglion cells throughout the human body, we were unable to find genomic DNA of these viruses in patients with definite MD and disabling vertigo, who underwent vestibular neurectomy. Based on these results, reactivation of HSV1 and VZV in the vestibular ganglion does not seem to play a role in the pathogenesis of MD. (c) 2008 S. Karger AG, Basel

Influence of bone-conducted vibration on simulator sickness in virtual reality

PubMed Central

Moon, Jae; Troje, Nikolaus F.

2018-01-01

Use of virtual reality (VR) technology is often accompanied by a series of unwanted symptoms, including nausea and headache, which are characterised as ‘simulator sickness’. Sensory mismatch has been thought to lie at the heart of the problem and recent studies have shown that reducing cue mismatch in VR can have a therapeutic effect. Specifically, electrical stimulation of vestibular afferent nerves (galvanic vestibular stimulation; GVS) can reduce simulator sickness in VR. However, GVS poses a risk to certain populations and can also result in negative symptoms in normal, healthy individuals. Here, we tested whether noisy vestibular stimulation through bone-vibration can also reduce symptoms of simulator sickness. We carried out two experiments in which participants performed a spatial navigation task in VR and completed the Simulator Sickness Questionnaire over a series of trials. Experiment 1 was conducted using a high-end projection-based VR display, whereas Experiment 2 involved the use of a consumer head mounted display. During each trial, vestibular stimulation was either: 1) absent; 2) coupled with large angular accelerations of the projection camera; or 3) applied randomly throughout each trial. In half of the trials, participants actively navigated using a motion controller, and in the other half they were moved passively through the environment along pre-recorded motion trajectories. In both experiments we obtained lower simulator sickness scores when vestibular stimulation was coupled with angular accelerations of the camera. This effect was obtained for both active and passive movement control conditions, which did not differ. The results suggest that noisy vestibular stimulation can reduce simulator sickness, and that this effect appears to generalize across VR conditions. We propose further examination of this stimulation technique. PMID:29590147

The adequate stimulus for avian short latency vestibular responses to linear translation

NASA Technical Reports Server (NTRS)

Jones, T. A.; Jones, S. M.; Colbert, S.

1998-01-01

Transient linear acceleration stimuli have been shown to elicit eighth nerve vestibular compound action potentials in birds and mammals. The present study was undertaken to better define the nature of the adequate stimulus for neurons generating the response in the chicken (Gallus domesticus). In particular, the study evaluated the question of whether the neurons studied are most sensitive to the maximum level of linear acceleration achieved or to the rate of change in acceleration (da/dt, or jerk). To do this, vestibular response thresholds were measured as a function of stimulus onset slope. Traditional computer signal averaging was used to record responses to pulsed linear acceleration stimuli. Stimulus onset slope was systematically varied. Acceleration thresholds decreased with increasing stimulus onset slope (decreasing stimulus rise time). When stimuli were expressed in units of jerk (g/ms), thresholds were virtually constant for all stimulus rise times. Moreover, stimuli having identical jerk magnitudes but widely varying peak acceleration levels produced virtually identical responses. Vestibular response thresholds, latencies and amplitudes appear to be determined strictly by stimulus jerk magnitudes. Stimulus attributes such as peak acceleration or rise time alone do not provide sufficient information to predict response parameter quantities. Indeed, the major response parameters were shown to be virtually independent of peak acceleration levels or rise time when these stimulus features were isolated and considered separately. It is concluded that the neurons generating short latency vestibular evoked potentials do so as "jerk encoders" in the chicken. Primary afferents classified as "irregular", and which traditionally fall into the broad category of "dynamic" or "phasic" neurons, would seem to be the most likely candidates for the neural generators of short latency vestibular compound action potentials.

Ocular Vestibular Evoked Myogenic Potentials Using Head Striker Stimulation

NASA Technical Reports Server (NTRS)

De Dios, Y. E.; Gadd, N. E.; Kofman, I. S.; Peters, B. T.; Reschke, M.; Bloomberg, J. J.; Wood, S. J.; Noohibezanjani, F.; Kinnaird, C.; Seidler, R. D.;

Framework Surgery for Treatment of Unilateral Vocal Fold Paralysis

PubMed Central

Daniero, James J.; Garrett, C. Gaelyn; Francis, David O.

2014-01-01

Laryngeal framework surgery is the current gold standard treatment for unilateral vocal fold paralysis. It provides a permanent solution to glottic insufficiency caused by injury to the recurrent laryngeal nerve. Various modifications to the original Isshiki type I laryngoplasty procedure have been described to improve voice and swallowing outcomes. The success of this procedure is highly dependent on the experience of the surgeon as it epitomizes the intersection of art and science in the field. The following article reviews the evidence, controversies, and complications related to laryngoplasty for unilateral vocal fold paralysis. It also provides a detailed analysis of how and when arytenoid-positioning procedures should be considered, and summarizes the literature on postoperative outcomes. PMID:24883239

A unilateral optic perineuritis in a teenager - A case report.

PubMed

Ameilia, Ahmad; Shatriah, Ismail; Wan-Hitam, Wan Hazabbah; Yunus, Rohaizan

2015-06-01

Optic perineuritis is an uncommon inflammatory disorder that involves optic nerve sheath. Numerous case reports have been published on optic perineuritis in adults, the majority of whom had bilateral presentation. There are limited data on optic perineuritis occurring in pediatric patients. We report a teenager who presented with a unilateral sign that mimicked the presentation of optic neuritis. The orbit and brain magnetic resonance imaging confirmed features of unilateral optic perineuritis. She was treated with a high dose of corticosteroids for 2weeks, and her final visual outcome was satisfactory. No signs of relapse were noted during follow-up visits. Copyright © 2014 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Cochleovestibular nerve development is integrated with migratory neural crest cells

PubMed Central

Sandell, Lisa L.; Butler Tjaden, Naomi E.; Barlow, Amanda J.; Trainor, Paul A.

2015-01-01

The cochleovestibular (CV) nerve, which connects the inner ear to the brain, is the nerve that enables the senses of hearing and balance. The aim of this study was to document the morphological development of the mouse CV nerve with respect to the two embryonic cells types that produce it, specifically, the otic vesicle-derived progenitors that give rise to neurons, and the neural crest cell (NCC) progenitors that give rise to glia. Otic tissues of mouse embryos carrying NCC lineage reporter transgenes were whole mount immunostained to identify neurons and NCC. Serial optical sections were collected by confocal microscopy and were compiled to render the three dimensional (3D) structure of the developing CV nerve. Spatial organization of the NCC and developing neurons suggest that neuronal and glial populations of the CV nerve develop in tandem from early stages of nerve formation. NCC form a sheath surrounding the CV ganglia and central axons. NCC are also closely associated with neurites projecting peripherally during formation of the vestibular and cochlear nerves. Physical ablation of NCC in chick embryos demonstrates that survival or regeneration of even a few individual NCC from ectopic positions in the hindbrain results in central projection of axons precisely following ectopic pathways made by regenerating NCC. PMID:24252775

PubMed Central

Praticò, A.D.; Serra, A.; Maiolino, L.; Cocuzza, S.; Di Mauro, P.; Licciardello, L.; Milone, P.; Privitera, G.; Belfiore, G.; Di Pietro, M.; Di Raimondo, F.; Romano, A.; Chiarenza, A.; Muglia, M.; Polizzi, A.; Evans, D.G.

2016-01-01

SUMMARY Neurofibromatosis type 2 [NF2; MIM # 101000] is an autosomal dominant disorder characterised by the occurrence of vestibular schwannomas (VSs), schwannomas of other cranial, spinal and cutaneous nerves, cranial and spinal meningiomas and/or other central nervous system (CNS) tumours (e.g., ependymomas, astrocytomas). Additional features include early onset cataracts, optic nerve sheath meningiomas, retinal hamartomas, dermal schwannomas (i.e., NF2-plaques), and (few) café-au-lait spots. Clinically, NF2 children fall into two main groups: (1) congenital NF2 - with bilateral VSs detected as early as the first days to months of life, which can be stable/asymptomatic for one-two decades and suddenly progress; and (2) severe pre-pubertal (Wishart type) NF2- with multiple (and rapidly progressive) CNS tumours other-than-VS, which usually present first, years before VSs [vs. the classical adult (Gardner type) NF2, with bilateral VSs presenting in young adulthood, sometimes as the only disease feature]. Some individuals can develop unilateral VS associated with ipsilateral meningiomas or multiple schwannomas localised to one part of the peripheral nervous system [i.e., mosaic NF2] or multiple non-VS, non-intradermal cranial, spinal and peripheral schwannomas (histologically proven) [schwannomatosis]. NF2 is caused by mutations in the NF2 gene at chromosome 22q12.1, which encodes for a protein called merlin or schwannomin, most similar to the exrin-readixin-moesin (ERM) proteins; mosaicNF2 is due to mosaic phenomena for the NF2 gene, whilst schwannomatosis is caused by coupled germ-line and mosaic mutations either in the SMARCB1 gene [SWNTS1; MIM # 162091] or the LZTR1 gene [SWNTS2; MIM # 615670] both falling within the 22q region and the NF2 gene. Data driven from in vitro and animal studies on the merlin pathway [e.g., post-translational and upstream/downstream regulation] allowed biologically targeted treatment strategies [e.g., Lapatinib, Erlotinib, Bevacizumab] aimed to multiple tumour shrinkage and/or regression and tumour arrest of progression with functional improvement. PMID:27958595

Novel Model of Somatosensory Nerve Transfer in the Rat.

PubMed

Paskal, Adriana M; Paskal, Wiktor; Pelka, Kacper; Podobinska, Martyna; Andrychowski, Jaroslaw; Wlodarski, Pawel K

2018-05-09

Nerve transfer (neurotization) is a reconstructive procedure in which the distal denervated nerve is joined with a proximal healthy nerve of a less significant function. Neurotization models described to date are limited to avulsed roots or pure motor nerve transfers, neglecting the clinically significant mixed nerve transfer. Our aim was to determine whether femoral-to-sciatic nerve transfer could be a feasible model of mixed nerve transfer. Three Sprague Dawley rats were subjected to unilateral femoral-to-sciatic nerve transfer. After 50 days, functional recovery was evaluated with a prick test. At the same time, axonal tracers were injected into each sciatic nerve distally to the lesion site, to determine nerve fibers' regeneration. In the prick test, the rats retracted their hind limbs after stimulation, although the reaction was moderately weaker on the operated side. Seven days after injection of axonal tracers, dyes were visualized by confocal microscopy in the spinal cord. Innervation of the recipient nerve originated from higher segments of the spinal cord than that on the untreated side. The results imply that the femoral nerve axons, ingrown into the damaged sciatic nerve, reinnervate distal targets with a functional outcome.

Measurement of amino acid levels in the vitreous humor of rats after chronic intraocular pressure elevation or optic nerve transection.

PubMed

Levkovitch-Verbin, Hana; Martin, Keith R G; Quigley, Harry A; Baumrind, Lisa A; Pease, Mary Ellen; Valenta, Danielle

2002-10-01

To investigate whether the levels of free amino acids and protein in the vitreous of rat eyes are altered with chronic intraocular pressure (IOP) elevation or after optic nerve transection. The concentrations of 20 amino acids in the vitreous humor were measured by high-performance liquid chromatography in both eyes of 41 rats with unilateral IOP elevation induced by translimbal photocoagulation. Eyes were studied 1 day and 1, 2, 4, and 9 weeks after initial IOP elevation. The same amino acids were measured in 41 rats 1 day and 2, 4, and 9 weeks after unilateral transection of the orbital optic nerve. The intravitreal protein level was assayed in additional 22 rats with IOP elevation and 12 rats after nerve transection. Two masked observers evaluated the amount of optic nerve damage with a semiquantitative, light-microscopic technique. In rats with experimental glaucoma, amino acid concentrations were unchanged 1 day after treatment. At 1 week, 4 of 20 amino acids (aspartate, proline, alanine, and lysine) were higher than in control eyes ( < or = 0.01), but this difference was nonsignificant after Bonferroni correction for multiple simultaneous amino acid comparisons (none achieved < 0.0025). No amino acid was significantly different from control in the nerve transection groups (all > 0.05). Vitreous protein level was significantly higher in glaucomatous eyes than their paired controls at 1 day ( < 0.0001) and 1 week ( < 0.002). One day and 1 week after optic nerve transection, vitreal proteins were significantly elevated compared with control eyes from untreated animals ( < 0.0020 and < 0.0022, respectively), though not compared with their fellow eyes ( = 0.25 and 0.10). Chronic experimental glaucoma and transection of the optic nerve increase the amount of protein in the rat vitreous above control levels. In the vitreous of rats with experimental glaucoma, a number of free amino acids were transiently elevated to a modest degree, but no significant difference in vitreous glutamate concentration was detected ( > 0.01).

Novel use of narrow paddle electrodes for occipital nerve stimulation--technical note.

PubMed

Abhinav, Kumar; Park, Nicholas D; Prakash, Savithru K; Love-Jones, Sarah; Patel, Nikunj K

2013-01-01

Occipital nerve stimulation (ONS), an established treatment for medically intractable headache syndromes, has lead migration rates quoted up to 24%. In a series of patients with ideal characteristics for this treatment modality, we describe an operative technique for ONS involving the novel use of narrow paddle electrodes: "S8 Lamitrode" (St. Jude Medical [SJM], St. Paul, MN, USA). Five patients (occipital neuralgia [ON] = 4; chronic migraine [CM] = 1) were treated with ONS between 2010 and 2011. All patients had a successful trial of peripheral neurostimulation (Algotec Ltd, Crawley, UK) therapy. Operative technique involved the use of a park-bench position, allowing simultaneous exposure of the occipital and infraclavicular regions. Through a retromastoid/occipital incision just beneath the external occipital protruberance, exposing the extrafascial plane, the S8 Lamitrode is implanted to intersect both greater occipital nerves for bilateral pain or unilateral greater and lesser occipital nerves for unilateral ON or with significant component of the pain relating to the lesser occipital nerve. Over the median follow-up of 12 months, there were no episodes of lead migration or revision. There also was significant improvement in symptoms in all patients. This is the first reported use of S8 Lamitrode electrode for ONS. This narrow electrode is suited for this role leading to minimal trauma during surgical placement, facilitates resolution of problems with lead migration, and optimizes effect with stimulation focused more in direction of the occipital nerves without skin involvement. To date, the SJM Genesis neurostimulation system, with percutaneous electrodes only, is CE mark approved in Europe for peripheral nerve stimulation of the occipital nerves for the management of pain and disability for patients diagnosed with intractable CM. Further developments and studies are required for better devices to suit ONS, thereby avoiding frequently encountered problems and which may clarify the role of paddle leads in ONS. © 2012 International Neuromodulation Society.

Recovery of function, peripheral sensitization and sensory neurone activation by novel pathways following axonal injury in Aplysia californica.

PubMed

Dulin, M F; Steffensen, I; Morris, C E; Walters, E T

1995-10-01

Recovery of behavioural and sensory function was examined following unilateral pedal nerve crush in Aplysia californica. Nerve crush that transected all axons connecting the tail to the central nervous system (CNS) eliminated the ipsilateral tail-evoked siphon reflex, whose sensory input travels in the crushed tail nerve (p9). The first reliable signs of recovery of this reflex were observed within 1 week, and most animals displayed tail-evoked siphon responses within 2 weeks. Wide-dynamic-range mechanosensory neurons with somata in the ventrocaudal (VC) cluster of the ipsilateral pleural ganglion exhibited a few receptive fields (RFs) on the tail 3 weeks after unilateral pedal nerve crush, indicating that the RFs had either regenerated or been reconnected to the central somata. These RFs were smaller and sensitized compared with corresponding RFs on the contralateral, uncrushed side. Centrally conducted axon responses of VC sensory neurones to electrical stimulation distal to the nerve crush site did not reappear until at least 10 days after the crush. Because the crush site was much closer to the CNS than to the tail, the failure of axon responses to be restored earlier than the behavioural responses indicates that early stages of reflex recovery are not due to regeneration of VC sensory neurone axons into the tail. Following nerve crush, VC sensory neurones often could be activated by stimulating central connectives or peripheral nerves that do not normally contain the sensory neurone's axons. These results suggest that recovery of behavioral function after nerve injury involves complex mechanisms, including regenerative growth of axotomized VC sensory neurones, sensitization of regenerating RFs and sprouting of VC sensory neurone fibres within the CNS. Furthermore, the rapidity of behavioural recovery indicates that its initial phases are mediated by additional mechanisms, perhaps centripetal regeneration of unidentified sensory neurones having peripheral somata, or transient reconnection of proximal and distal stumps of axotomized VC cells.

Sciatic Nerve Stimulation and its Effects on Upper Airway Resistance in the Anesthetized Rabbit Model Relevant to Sleep Apnea.

PubMed

Schiefer, Matthew; Gamble, Jenniffer; Strohl, Kingman Perkins

2018-06-07

Obstructive sleep apnea (OSA) is a disorder characterized by collapse of the velopharynx and/or oropharynx during sleep when drive to the upper airway is reduced. Here, we explore an indirect approach for activation of upper airway muscles which might affect airway dynamics- unilateral electrical stimulation of the afferent fibers of the sciatic nerve- in an anesthetized rabbit model. A nerve cuff electrode was placed around the sciatic and hypoglossal nerves to deliver stimulus while air flow, air pressure, and alae nasi electromyogram (EMG) were monitored both prior to and after sciatic transection. Sciatic nerve stimulation increased respiratory effort, rate, and alae nasi EMG, which persisted for seconds after stimulation; however, upper airway resistance was unchanged. Hypoglossal stimulation reduced resistance without altering drive. While sciatic nerve stimulation is not ideal for treating obstructive sleep apnea, it remains a target for altering respiratory drive.

Acquired auditory neuropathy spectrum disorder after an attack of chikungunya: case study.

PubMed

Prabhu, Prashanth

2016-01-01

Auditory neuropathy spectrum disorder (ANSD) is a retrocochlear disorder in which the cochlear functioning is normal but the transmission in the auditory neural pathway is affected. The present study reports of a 14-year-old teenager with acquired ANSD after an attack of chikungunya. He reported symptoms of difficulty in understanding speech, tinnitus and vertigo when exposed to loud sounds. The audiological characteristics suggested auditory neuropathy spectrum disorder with raising audiogram configuration. The results of tinnitus evaluation showed low-pitched tinnitus and it was persistent causing significant handicap to him based on self report tinnitus handicap questionnaire results. The results of depression, anxiety and stress scale also suggested symptoms of mild depression and anxiety. Chikungunya virus is suspected to be neurotropic in nature which can damage auditory nerve cells and may have caused ANSD. The result also shows presence of tullio's phenomenon and absence of cervical vestibular evoked myogenic potentials suggesting damage to the vestibular neuronal system. The possible pathophysiology of chikungunya virus causing ANSD and vestibular symptoms needs to be explored further in future studies.

The vestibulocochlear bases for wartime posttraumatic stress disorder manifestations.

PubMed

Tigno, T A; Armonda, R A; Bell, R S; Severson, M A

2017-09-01

Preliminary findings based on earlier retrospective studies of 229 wartime head injuries managed by the Walter Reed Army Medical Center (WRAMC)/National Naval Medical Center (NNMC) Neurosurgery Service during the period 2003-08 detected a threefold rise in Posttraumatic Stress Disorder (PTSD) manifestations (10.45%) among Traumatic Brain Injuries (TBI) having concomitant vestibulocochlear injuries compared to 3% for the TBI group without vestibulo-cochlear damage (VCD), prompting the authors to undertake a more focused study of the vestibulo-auditory pathway in explaining the development of posttraumatic stress disorder manifestations among the mostly Blast-exposed head-injured. The subsequent historical review of PTSD pathophysiology studies, the evidence for an expanded vestibular system and of a dominant vestibular system, the vascular vulnerability of the vestibular nerves in stress states as well as the period of cortical imprinting has led to the formation of a coherent hypotheses utilizing the vestibulocochlear pathway in understanding the development of PTSD manifestations. Neuroimaging and neurophysiologic tests to further validate the vestibulocochlear concept on the development of PTSD manifestations are proposed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Modelling the vestibular head tilt response.

PubMed

Heibert, D; Lithgow, B

2005-03-01

This paper attempts to verify the existence of potentially diagnostically significant periodic signals thought to exist in recordings of neural activity originating from the vestibular nerve, following a single tilt of the head. It then attempts to find the physiological basis of this signal, in particular focusing on the mechanical response of the vestibular system. Simple mechanical models of the semi circular canals having angular velocities applied to them were looked at. A simple single canal model was simulated using CFX software. Finally, a simple model of all three canals with elastic duct walls and a moving cupula was constructed. Pressure waves within the canals were simulated using water hammer or pressure transient theory. In particular, it was investigated whether pressure waves within the utricle following a square pulse angular velocity applied to the canal(s) may be responsible for quasi-periodic oscillatory signals. The simulations showed that there are no pressure waves resonating within the canals following a square pulse angular velocity applied to the canal(s). The results show that the oscillatory signals are most likely not mechanical in origin. It was concluded that further investigation is required.

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

PubMed

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

2016-12-01

Lower extremity spasticity is a common sequela among patients with acquired brain injury. The optimum treatment remains controversial. The aim of our study was to test the feasibility and effectiveness of contralateral nerve root transfer in reducing post stroke spasticity of the affected hindlimb muscles in rats. In our study, we for the first time created a novel animal hindlimb spastic hemiplegia model in rats with photothrombotic lesion of unilateral motor cortex and we established a novel surgical procedure in reducing motor cortex lesion-induced hindlimb spastic hemiplegia in rats. Thirty six rats were randomized into three groups. In group A, rats received sham operation. In group B, rats underwent unilateral hindlimb motor cortex lesion. In group C, rats underwent unilateral hindlimb cortex lesion followed by contralateral L4 ventral root transfer to L5 ventral root of the affected side. Footprint analysis, Hoffmann reflex (H-reflex), cholera toxin subunit B (CTB) retrograde tracing of gastrocnemius muscle (GM) motoneurons and immunofluorescent staining of vesicle glutamate transporter 1 (VGLUT1) on CTB-labelled motoneurons were used to assess spasticity of the affected hindlimb. Sixteen weeks postoperatively, toe spread and stride length recovered significantly in group C compared with group B (P<0.001). H max (H-wave maximum amplitude)/M max (M-wave maximum amplitude) ratio of gastrocnemius and plantaris muscles (PMs) significantly reduced in group C (P<0.01). Average VGLUT1 positive boutons per CTB-labelled motoneurons significantly reduced in group C (P<0.001). We demonstrated for the first time that contralateral L4 ventral root transfer to L5 ventral root of the affected side was effective in relieving unilateral motor cortex lesion-induced hindlimb spasticity in rats. Our data indicated that this could be an alternative treatment for unilateral lower extremity spasticity after brain injury. Therefore, contralateral neurotization may exert a potential therapeutic candidate to improve the function of lower extremity in patients with spastic hemiplegia. © 2016 The Author(s).

Indications for Direct Laryngoscopic Examination of Vocal Cord Function Prior to Anterior Cervical Surgery

PubMed Central

Nazemi, Alireza; Carmouche, Jonathan; Albert, Todd; Behrend, Caleb

2016-01-01

Recurrent laryngeal nerve palsy (RLNP) is among the most common complications in both thyroid surgeries and anterior approaches to the cervical spine, having both a diverse etiology and presentation. Most bilateral paresis, with subsequent devastating impact on patients, are due to failure to recognize unilateral recurrent laryngeal nerve paralysis and, although rare, are entirely preventable with appropriate history and screening. Recurrent laryngeal nerve palsy has been shown to present asymptomatically in as high as 32% of cases, which yields limitations on exclusively screening with physical examination. Based on the available literature, diagnosis of unilateral RLNP is the critical factor in preventing the occurrence of bilateral RLNP as the surgeon may elect to operate on the injured side to prevent bilateral paresis. Analysis of incidence rates shows postoperative development of unilateral RLNP is 13.1 (95% confidence interval [CI]: 6.1-28.1) and 13.90 (95% CI: 6.6-29.3) times more likely in anterior spine and thyroid surgery, respectively, in comparison with intubation. Currently, there is no consensus on when to order a preoperative laryngoscopic examination prior to anterior cervical spine surgery. The importance of patient history should be emphasized, as it is the basis for indications of preoperative laryngoscopy. Efforts to minimize postoperative complications must be made, especially when considering the rising rate of cervical fusion. This study presents a systematic review of the literature defining key causes of RLNP, with a probability-based protocol to indicate direct laryngoscopy prior to anterior cervical surgery as a screening tool in the prevention of bilateral RLNP. PMID:28255513

Can Vestibular-Evoked Myogenic Potentials Help Differentiate Ménière Disease from Vestibular Migraine?

PubMed Central

Zuniga, M. Geraldine; Janky, Kristen L.; Schubert, Michael C.; Carey, John P.

2013-01-01

Objectives To characterize both cervical and ocular vestibular-evoked myogenic potential (cVEMP, oVEMP) responses to air-conducted sound (ACS) and midline taps in Ménière disease (MD), vestibular migraine (VM), and controls, as well as to determine if cVEMP or oVEMP responses can differentiate MD from VM. Study Design Prospective cohort study. Setting Tertiary referral center. Subjects and Methods Unilateral definite MD patients (n = 20), VM patients (n = 21) by modified Neuhauser criteria, and age-matched controls (n = 28). cVEMP testing used ACS (clicks), and oVEMP testing used ACS (clicks and 500-Hz tone bursts) and midline tap stimuli (reflex hammer and Mini-Shaker). Outcome parameters were cVEMP peak-to-peak amplitudes and oVEMP n10 amplitudes. Results Relative to controls, MD and VM groups both showed reduced click-evoked cVEMP (P < .001) and oVEMP (P < .001) amplitudes. Only the MD group showed reduction in tone-evoked amplitudes for oVEMP. Tone-evoked oVEMPs differentiated MD from controls (P = .001) and from VM (P = .007). The oVEMPs in response to the reflex hammer and Mini-Shaker midline taps showed no differences between groups (P > .210). Conclusions Using these techniques, VM and MD behaved similarly on most of the VEMP test battery. A link in their pathophysiology may be responsible for these responses. The data suggest a difference in 500-Hz tone burst–evoked oVEMP responses between MD and MV as a group. However, no VEMP test that was investigated segregated individuals with MD from those with VM. PMID:22267492

Do bilateral and unilateral greater occipital nerve block effectiveness differ in chronic migraine patients?

PubMed

Ünal-Artık, Hanzade Aybüke; İnan, Levent Ertuğrul; Ataç-Uçar, Ceyla; Yoldaş, Tahir Kurtuluş

2017-06-01

We aimed to compare the effectiveness of bilateral and unilateral block application in chronic migraine patients and whether there were differences in their effectiveness retrospectively. In chronic migraine patients undergoing Greater occipital nerve (GON) block, mean number of days with pain per month before and after block, mean duration of pain in attacks (in hours), and mean Visual Analog Scale (VAS) in attack and pain severity were recorded from files. The patients underwent one block a week for the first 1 month, thereafter one block a month according to GON block protocol used by our institute. Of 41 patients included in the study, 23 underwent unilateral block (group 1) and 18 underwent bilateral block (group 2). In both groups, number of days with migraine decreased significantly in 2 and 3 months as compared to pre-block treatment (P < 0.001). Mean duration of headache decreased in group 2 during treatment (P < 0.001). In group 1, mean duration of headache also decreased but did not differ significantly (P = 0.051). Mean severity of migraine decreased significantly differ in group 1 in 2, 3 months as compared to pre-block treatment (P < 0.001). No differences were observed in frequency, severity and duration of headache between groups during 3-month treatment period. GON block is effective in chronic migraine and bilateral application is no superior over unilateral application.

Somatosensory Projections to Cochlear Nucleus are Up-regulated after Unilateral Deafness

PubMed Central

Zeng, Chunhua; Yang, Ziheng; Shreve, Lauren; Bledsoe, Sanford; Shore, Susan

2012-01-01

The cochlear nucleus (CN) receives innervation from auditory and somatosensory structures, which can be identified using vesicular glutamate transporters, VGLUT1 and VGLUT2. VGLUT1 is highly expressed in the magnocellular ventral CN (VCN), which receives auditory nerve inputs. VGLUT2 is predominantly expressed in the granule cell domain (GCD), which receives non-auditory inputs from somatosensory nuclei, including spinal trigeminal nucleus (Sp5) and cuneate nucleus (Cu). Two weeks after unilateral deafening VGLUT1 is significantly decreased in ipsilateral VCN while VGLUT2 is significantly increased in the ipsilateral GCD (Zeng et al., 2009), putatively reflecting decreased inputs from auditory nerve and increased inputs from non-auditory structures in guinea pigs. Here we wished to determine whether the upregulation of VGLUT2 represents increases in the number of somatosensory projections to the CN that are maintained for longer periods of time. Thus we examined concurrent changes in VGLUT levels and somatosensory projections in the CN using immunohistochemistry combined with anterograde tract tracing three and six weeks following unilateral deafening. The data reveal that unilateral deafness leads to increased numbers of VGLUT2-colabeled Sp5 and Cu projections to the ventral and dorsal CN. These findings suggest that Sp5 and Cu play significant and unique roles in cross-modal compensation and that, unlike after shorter term deafness, neurons in the magnocelluar regions also participate in the compensation. The enhanced glutamatergic somatosensory projections to the CN may play a role in neural spontaneous hyperactivity associated with tinnitus. PMID:23136418

Transient facial nerve paralysis (Bell's palsy) following administration of hepatitis B recombinant vaccine: a case report.

PubMed

Paul, R; Stassen, L F A

2014-01-01

Bell's palsy is the sudden onset of unilateral transient paralysis of facial muscles resulting from dysfunction of the seventh cranial nerve. Presented here is a 26-year-old female patient with right lower motor neurone facial palsy following hepatitis B vaccination. Readers' attention is drawn to an uncommon cause of Bell's palsy, as a possible rare complication of hepatitis B vaccination, and steps taken to manage such a presentation.

Pharmacological Prevention and Reversion of Erectile Dysfunction after Radical Prostatectomy, By Modulation of Nitric Oxide/Cgmp Pathways

DTIC Science & Technology

2008-03-01

Figure 3. Time course of the effect of bilateral cavernosal nerve resection on the smooth muscle cell content in the rat corpora cavernosa. Penile...iindicates the apoptotic cells in the corpora cavernosa. Bottom: QIA for TUNEL ***Pɘ.001 Figure 7: Time course of the effect of bilateral...Figure 6 Effect of unilateral and bilateral cavernosal nerve resection and long-term sildenafil treatment on cell proliferation and turnover in the

Otolith and Vertical Canal Contributions to Dynamic Postural Control

NASA Technical Reports Server (NTRS)

Black, F. Owen

1999-01-01

The objective of this project is to determine: 1) how do normal subjects adjust postural movements in response to changing or altered otolith input, for example, due to aging? and 2) how do patients adapt postural control after altered unilateral or bilateral vestibular sensory inputs such as ablative inner ear surgery or ototoxicity, respectively? The following hypotheses are under investigation: 1) selective alteration of otolith input or abnormalities of otolith receptor function will result in distinctive spatial, frequency, and temporal patterns of head movements and body postural sway dynamics. 2) subjects with reduced, altered, or absent vertical semicircular canal receptor sensitivity but normal otolith receptor function or vice versa, should show predictable alterations of body and head movement strategies essential for the control of postural sway and movement. The effect of altered postural movement control upon compensation and/or adaptation will be determined. These experiments provide data for the development of computational models of postural control in normals, vestibular deficient subjects and normal humans exposed to unusual force environments, including orbital space flight.

On the Origin of the 1,000 Hz Peak in the Spectrum of the Human Tympanic Electrical Noise

PubMed Central

Pardo-Jadue, Javiera; Dragicevic, Constantino D.; Bowen, Macarena; Delano, Paul H.

2017-01-01

The spectral analysis of the spontaneous activity recorded with an electrode positioned near the round window of the guinea pig cochlea shows a broad energy peak between 800 and 1,000 Hz. This spontaneous electric activity is called round window noise or ensemble background activity. In guinea pigs, the proposed origin of this peak is the random sum of the extracellular field potentials generated by action potentials of auditory nerve neurons. In this study, we used a non-invasive method to record the tympanic electric noise (TEN) in humans by means of a tympanic wick electrode. We recorded a total of 24 volunteers, under silent conditions or in response to stimuli of different modalities, including auditory, vestibular, and motor activity. Our results show a reliable peak of spontaneous activity at ~1,000 Hz in all studied subjects. In addition, we found stimulus-driven responses with broad-band noise that in most subjects produced an increase in the magnitude of the energy band around 1,000 Hz (between 650 and 1,200 Hz). Our results with the vestibular stimulation were not conclusive, as we found responses with all caloric stimuli, including 37°C. No responses were observed with motor tasks, like eye movements or blinking. We demonstrate the feasibility of recording neural activity from the electric noise of the tympanic membrane with a non-invasive method. From our results, we suggest that the 1,000 Hz component of the TEN has a mixed origin including peripheral and central auditory pathways. This research opens up the possibility of future clinical non-invasive techniques for the functional study of auditory and vestibular nerves in humans. PMID:28744193

On the Origin of the 1,000 Hz Peak in the Spectrum of the Human Tympanic Electrical Noise.

PubMed

Pardo-Jadue, Javiera; Dragicevic, Constantino D; Bowen, Macarena; Delano, Paul H

2017-01-01

The spectral analysis of the spontaneous activity recorded with an electrode positioned near the round window of the guinea pig cochlea shows a broad energy peak between 800 and 1,000 Hz. This spontaneous electric activity is called round window noise or ensemble background activity. In guinea pigs, the proposed origin of this peak is the random sum of the extracellular field potentials generated by action potentials of auditory nerve neurons. In this study, we used a non-invasive method to record the tympanic electric noise (TEN) in humans by means of a tympanic wick electrode. We recorded a total of 24 volunteers, under silent conditions or in response to stimuli of different modalities, including auditory, vestibular, and motor activity. Our results show a reliable peak of spontaneous activity at ~1,000 Hz in all studied subjects. In addition, we found stimulus-driven responses with broad-band noise that in most subjects produced an increase in the magnitude of the energy band around 1,000 Hz (between 650 and 1,200 Hz). Our results with the vestibular stimulation were not conclusive, as we found responses with all caloric stimuli, including 37°C. No responses were observed with motor tasks, like eye movements or blinking. We demonstrate the feasibility of recording neural activity from the electric noise of the tympanic membrane with a non-invasive method. From our results, we suggest that the 1,000 Hz component of the TEN has a mixed origin including peripheral and central auditory pathways. This research opens up the possibility of future clinical non-invasive techniques for the functional study of auditory and vestibular nerves in humans.

Unfavourable results in the repair of the cleft lip

PubMed Central

Narayanan, Puthucode V.; Adenwalla, Hirji Sorab

2013-01-01

Introduction: Unfavorable results in unilateral and bilateral cleft lip repair are often easy to spot but not always easy to prevent as to treat. We have tried to deal with the more common problems and explain possible causes and the best possible management options from our experience. Unilateral cleft lip repair: Unfavorable results immediately after repair involve Dehiscence and Scaring. Delayed blemishes include vermillion notching, a short lip, deficiency in the height of the lateral vermillion on the cleft side, white roll malalignment, oro-vestibular fistula, the cleft lip nose deformity, a narrow nostril and a “high-riding” nostril. We analyze the causes of these blemishes and outline our views regarding the treatment of these. Bilateral cleft lip: Immediate problems again include dehiscence as also loss of prolabium or premaxilla. Delayed unfavorable results are central vermillion deficiency, a lip that is too tight, bilateral cleft lip nose deformity, problems with the premaxilla and maxillary growth disturbances. Here again we discuss the causation of these problems and our preferred methods of treatment. Conclusion: We have detailed the significant unfavorable results after unilateral and bilateral cleft lip surgery. The methods of treatment advocated have been layer from our own experience. PMID:24501453

Phrenic Nerve Palsy Secondary to Parsonage-Turner Syndrome: A Diagnosis Commonly Overlooked.

PubMed

McEnery, Tom; Walsh, Ronan; Burke, Conor; McGowan, Aisling; Faul, John; Cormican, Liam

2017-04-01

Neuralgic Amyotrophy (NA) or Parsonage-Turner syndrome is an idiopathic neuropathy commonly affecting the brachial plexus. Associated phrenic nerve involvement, though recognised, is thought to be very rare. We present a case series of four patients (all male, mean age 53) presenting with dyspnoea preceded by severe self-limiting upper limb and shoulder pain, with an elevated hemi-diaphragm on clinical examination and chest X-ray. Neurological examination of the upper limb at the time of presentation was normal. Diaphragmatic fluoroscopy confirmed unilateral diaphragmatic paralysis. Pulmonary function testing demonstrated characteristic reduction in forced vital capacity between supine and sitting position (mean 50%, range 42-65% predicted, mean change 23%, range 22-46%), reduced maximal inspiratory pressures (mean 61%, range 43-86% predicted), reduced sniff nasal inspiratory pressure (mean 88.25, range 66-109 cm H 2 O) and preserved maximal expiratory pressure (mean 107%, range 83-130% predicted). Phrenic nerve conduction studies confirmed phrenic nerve palsy. All patients were managed conservatively. Follow-up ranged from 6 months to 3 years. Symptoms and lung function variables normalised in three patients and improved significantly in the fourth. The classic history of severe ipsilateral shoulder and upper limb neuromuscular pain should be elicited and thus NA considered in the differential for a unilateral diaphragmatic paralysis, even in the absence of neurological signs. Parsonage-Turner syndrome is likely to represent a significantly under-diagnosed aetiology of phrenic nerve palsy. Conservative management as opposed to surgical intervention is advocated as most patients demonstrate gradual resolution over time in this case series.

Correlation between bithermal caloric test results and vestibular evoked myogenic potentials (VEMPs) in normal subjects.

PubMed

Andrade, Isabel Vaamonde Sanchez; Santos-Perez, Sofia; Diz, Pilar Gayoso; Caballero, Torcuato Labella; Soto-Varela, Andrés

2013-05-01

Bithermal caloric testing and vestibular evoked myogenic potentials (VEMPs) are both diagnostic tools for the study of the vestibular system. The first tests the horizontal semicircular canal and the second evaluates the saccule and lower vestibular nerve. The results of these two tests can therefore be expected to be correlated. The aim of this study was to compare bithermal caloric test results with VEMP records in normal subjects to verify whether they are correlated. A prospective study was conducted in 60 healthy subjects (30 men and 30 women) who underwent otoscopy, pure tone audiometry, bithermal caloric testing and VEMPs. From the caloric test, we assessed the presence of possible vestibular hypofunction, whether there was directional preponderance and reflectivity of each ear (all based on both slow phase velocity and nystagmus frequency). The analysed VEMPs variables were: p1 and n1 latency, corrected amplitude, interaural p1 latency difference and p1 interaural amplitude asymmetry. We compared the reflectivity, hypofunction and directional preponderance of the caloric tests with the corrected amplitudes and amplitude asymmetries of the VEMPs. No correlations were found in the different comparisons between bithermal caloric testing results and VEMPs except for a weak correlation (p = 0.039) when comparing preponderance based on the number of nystagmus in the caloric test and amplitude asymmetry with 99 dB tone burst in the VEMPs test. The results indicate that the two diagnostic tests are not comparable, so one of them cannot replace the other, but the use of both increases diagnostic success in some conditions.

Facial nerve activity disrupts psychomotor rhythms in the forehead microvasculature.

PubMed

Drummond, Peter D; O'Brien, Geraldine

2011-10-28

Forehead blood flow was monitored in seven participants with a unilateral facial nerve lesion during relaxation, respiratory biofeedback and a sad documentary. Vascular waves at 0.1Hz strengthened during respiratory biofeedback, in tune with breathing cycles that also averaged 0.1Hz. In addition, a psychomotor rhythm at 0.15Hz was more prominent in vascular waveforms on the denervated than intact side of the forehead, both before and during relaxation and the sad documentary. These findings suggest that parasympathetic activity in the facial nerve interferes with the psychomotor rhythm in the forehead microvasculature. Copyright © 2011 Elsevier B.V. All rights reserved.

Tumors Presenting as Multiple Cranial Nerve Palsies

PubMed Central

Kumar, Kishore; Ahmed, Rafeeq; Bajantri, Bharat; Singh, Amandeep; Abbas, Hafsa; Dejesus, Eddy; Khan, Rana Raheel; Niazi, Masooma; Chilimuri, Sridhar

2017-01-01

Cranial nerve palsy could be one of the presenting features of underlying benign or malignant tumors of the head and neck. The tumor can involve the cranial nerves by local compression, direct infiltration or by paraneoplastic process. Cranial nerve involvement depends on the anatomical course of the cranial nerve and the site of the tumor. Patients may present with single or multiple cranial nerve palsies. Multiple cranial nerve involvement could be sequential or discrete, unilateral or bilateral, painless or painful. The presentation could be acute, subacute or recurrent. Anatomic localization is the first step in the evaluation of these patients. The lesion could be in the brain stem, meninges, base of skull, extracranial or systemic disease itself. We present 3 cases of underlying neoplasms presenting as cranial nerve palsies: a case of glomus tumor presenting as cochlear, glossopharyngeal, vagus and hypoglossal nerve palsies, clivus tumor presenting as abducens nerve palsy, and diffuse large B-cell lymphoma presenting as oculomotor, trochlear, trigeminal and abducens nerve palsies due to paraneoplastic involvement. History and physical examination, imaging, autoantibodies and biopsy if feasible are useful for the diagnosis. Management outcomes depend on the treatment of the underlying tumor. PMID:28553221

Glucocorticoids improve acute dizziness symptoms following acute unilateral vestibulopathy.

PubMed

Batuecas-Caletrío, Angel; Yañez-Gonzalez, Raquel; Sanchez-Blanco, Carmen; Pérez, Pedro Blanco; González-Sanchez, Enrique; Sanchez, Luis Alberto Guardado; Kaski, Diego

2015-11-01

Acute unilateral vestibulopathy (AUV) is characterized by acute vertigo, nausea, and imbalance without neurological deficits or auditory symptomatology. Here, we explore the effect of glucocorticoid treatment on the degree of canal paresis in patients with AUV, and critically, establish its relationship with dizziness symptom recovery. We recruited consecutive patients who were retrospectively assigned to one of the two groups according to whether they received glucocorticoid treatment (n = 32) or not (n = 44). All patients underwent pure-tone audiometry, bithermal caloric testing, MRI brain imaging, and were asked to complete a dizziness handicap inventory on admission to hospital and just prior to hospital discharge. In the treatment group, the canal paresis at discharge was significantly lower than in the control group (mean ± SD % 38.04 ± 21.57 versus 82.79 ± 21.51, p < 0.001). We also observed a significant reduction in the intensity of nystagmus in patients receiving glucocorticoid treatment compared to the non-treatment group (p = 0.03). DHI test score was significantly lower at discharge in the treatment group (mean ± SD % 23.15 ± 12.40 versus 64.07 ± 12.87, p < 0.001), as was the length of hospital stay (2.18 ± 1.5 days versus 3.6 ± 1.7 days, p = 0.002). Glucocorticoid treatment leads to acute symptomatic improvement, with a reduced hospital stay and reduction in the intensity of acute nystagmus. Our findings suggest that glucocorticoids may accelerate vestibular compensation via a restoration of peripheral vestibular function, and therefore has important clinical implications for the treatment of AUV.

Intracellular distributions and putative functions of calcium-binding proteins in the bullfrog vestibular otolith organs

NASA Technical Reports Server (NTRS)

Baird, R. A.; Steyger, P. S.; Schuff, N. R.

1997-01-01

Hair cells in the bullfrog vestibular otolith organs were immunolabeled by monoclonal and polyclonal antisera against calbindin (CaB), calmodulin (CaM), calretinin (CaR), and parvalbumin (PA). S-100, previously shown to immunolabel striolar hair cells in fish vestibular organs, only weakly immunolabeled hair cells in the bullfrog vestibular otolith organs. Immunolabeling was not detected in supporting cells. With the exception of CaR, myelinated axons and unmyelinated nerve terminals were immunolabeled by all of the above antisera. Immunolabeling was seen in all saccular hair cells, although hair cells at the macular margins were immunolabeled more intensely for CaB, CaM, and PA than more centrally located hair cells. As the macula margins are known to be a growth zone, this labeling pattern suggests that marginal hair cells up-regulate their calcium-binding proteins during hair cell development. In the utriculus, immunolabeling for CaM and PA was generally restricted to striolar hair cells. CaR immunolabeling was restricted to the stereociliary array. Immunolabeling for other calcium-binding proteins was generally seen in both the cell body and hair bundles of hair cells, although this labeling was often localized to the stereociliary array and the apical portion of the cell body. CaM and PA immunolabeling in the stereociliary array in saccular and utricular striolar cells suggests a functional role for these proteins in mechanoelectric transduction and adaptation.

Hearing, speech, language, and vestibular disorders in the fetal alcohol syndrome: a literature review.

PubMed

Church, M W; Kaltenbach, J A

1997-05-01

Fetal alcohol syndrome (FAS) is characterized in part by mental impairment, as well as craniofacial and ocular anomalies. These conditions are traditionally associated with childhood hearing disorders, because they all have a common embryonic origin in malformations of the first and second branchial arches, and have similar critical periods of vulnerability to toxic insult. A review of human and animal research indicates that there are four types of hearing disorders associated with FAS. These are: (1) a developmental delay in auditory maturation, (2) sensorineural hearing loss, (3) intermittent conductive hearing loss due to recurrent serous otitis media, and (4) central hearing loss. The auditory and vestibular systems share the same peripheral apparatuses (the inner ear and eighth cranial nerve) and are embryologically and structurally similar. Consequently, vestibular disorders in FAS children might be expected. The evidence for vestibular dysfunction in FAS is ambiguous, however. Like other syndromes associated with craniofacial anomalies, hearing disorders, and mental impairment, FAS is also characterized by a high prevalence of speech and language pathology. Hearing disorders are a form of sensory deprivation. If present during early childhood, they can result in permanent hearing, language, and mental impairment. Early identification and intervention to treat hearing, language, and speech disorders could therefore result in improved outcome for the FAS child. Specific recommendations are made for intervention and future research.

Electrophysiological abnormalities associated with extensive myelinated retinal nerve fibers.

PubMed

Tay, Su Ann; Sanjay, Srinivasan

2012-07-01

An observational case report of electrophysiological abnormalities in a patient with anisomyopic amblyopia as a result of unilateral extensive myelinated retinal nerve fibers (MNFs) is illustrated. The electrophysiological readings revealed an abnormal pattern electroretinogram (PERG) but normal full-field electroretinogram readings in the affected eye. The visual-evoked potential was also undetectable in that eye. Our findings suggest that extensive MNFs can be associated with electrophysiological abnormalities, in particular the PERG, which can aid in diagnosing the cause of impaired vision when associated with amblyopia.

Abnormalities of gaze in cerebrovascular disease.

PubMed

Pedersen, R A; Troost, B T

1981-01-01

Disorders of ocular motility may occur after injury at several levels of the neuraxis. Unilateral supranuclear disorders of gaze tend to be transient; bilateral disorders more enduring. Nuclear disorders of gaze also tend to be enduring and are frequently present in association with long tract signs and cranial nerve palsies on opposite sides of the body. Nystagmus is a reliable sign of posterior fossa or peripheral eight nerve pathology. Familiarity with these concepts may help the clinician answer questions regarding localization and prognosis.

Vestibular evoked myogenic potentials in response to lateral skull taps are dependent on two different mechanisms.

PubMed

Brantberg, Krister; Westin, Magnus; Löfqvist, Lennart; Verrecchia, Luca; Tribukait, Arne

2009-05-01

To explore the mechanisms for skull tap induced vestibular evoked myogenic potentials (VEMP). The muscular responses were recorded over both sternocleidomastoid (SCM) muscles using skin electrodes. A skull tapper which provided a constant stimulus intensity was used to test cervical vestibular evoked myogenic potentials (VEMP) in response to lateral skull taps in healthy subjects (n=10) and in patients with severe unilateral loss of vestibular function (n=10). Skull taps applied approximately 2 cm above the outer ear canal caused highly reproducible VEMP. There were differences in VEMP in both normals and patients depending on side of tapping. In normals, there was a positive-negative ("normal") VEMP on the side contra-lateral to the skull tapping, but no significant VEMP ipsi-laterally. In patients, skull taps above the lesioned ear caused a contra-lateral positive-negative VEMP (as it did in the normals), in addition there was an ipsi-lateral negative-positive ("inverted") VEMP. When skull taps were presented above the healthy ear there was only a small contra-lateral positive-negative VEMP but, similar to the normals, no VEMP ipsi-laterally. The present data, in conjunction with earlier findings, support a theory that skull-tap VEMP responses are mediated by two different mechanisms. It is suggested that skull tapping causes both a purely ipsi-lateral stimulus side independent SCM response and a bilateral and of opposite polarity SCM response that is stimulus side dependent. Possibly, the skull tap induced VEMP responses are the sum of a stimulation of two species of vestibular receptors, one excited by vibration (which is rather stimulus site independent) and one excited by translation (which is more stimulus site dependent). Skull-tap VEMP probably have two different mechanisms. Separation of the two components might reveal the status of different labyrinthine functions.

The Vestibular Apparatus under Water and in Compressed Gas Environments: Abstracts of Translated Studies

DTIC Science & Technology

1975-02-01

found no evidence for progressive degeneration of the neurological symptoms, although there was no recovery either. 13. LANGE, J., I. ROZSAHEGYI...des Gehoemerven in den Maculae und Cristae Acustlcae Im Gehoerlabyrinth der Wirbeltiere. (The manner of termina- tion of the auditory nerve in the... maculae and cristae acustlcae in the auditory labyrinth of vertebrates. Trans, by Mrs. A. Woke, NMRI, 1972.) Biologische Untersuchungen (Stockholm

Electrophysiologic identification of the cochlear nerve fibers during cerebello-pontine angle surgery.

PubMed

Colletti, V; Fiorino, F G

1993-11-01

To facilitate identification and preservation of the auditory nerve during cerebello-pontine angle surgery, bipolar recording of cochlear nerve compound action potentials (CNAPs) was performed. Two silver wires insulated with teflon up to the exposed ends were utilized as electrodes. They were twisted together, the distance between the two tips being 1 mm or less. Rarefaction polarity clicks (31/s) ranging from the psychoacoustical threshold to 120 dB pe SPL were used as stimuli. The investigation was performed in three groups of patients. The first group consisted of 9 patients submitted to vestibular neurectomy and 4 patients operated on by microvascular decompression of the eighth nerve. The second group comprised 8 patients with acoustic tumors smaller than 2 mm and serviceable hearing. Postoperative audiometric results in the subjects in the second group were compared with those obtained in well-matched homogeneous controls consisting of patients with acoustic neuroma operated on without the aid of CNAP recording. Bipolar recording from the eighth nerve was extremely selective, a good response being obtained only when positioning the electrode on the cochlear portion of the eighth nerve. During removal of the acoustic neuroma, repeated bipolar probing of the tumor and eighth nerve facilitated the task of distinguishing the cochlear nerve from other nervous structures and from the tumor, and contributed to preserving hearing in most patients.

Pan-brachial plexus neuropraxia following lightning: A rare case report.

PubMed

Patnaik, Ashis; Mahapatra, Ashok Kumar; Jha, Menka

2015-01-01

Neurological complications following lightning are rare and occur in form of temporary neurological deficits of central origin. Involvement of peripheral nervous system is extremely rare and only a few cases have been described in the literature. Isolated unilateral pan-brachial plexus neuropraxia has never been reported in the literature. Steroids have long been used for treatment of neuropraxia. However, their use in lightning neural injury is unique and requires special mention. We report a rare case of lightning-induced unilateral complete flaccid paralysis along with sensory loss in a young patient. Lightning typically causes central nervous involvement in various types of motor and sensory deficit. Surprisingly, the nerve conduction study showed the involvement of peripheral nervous system involvement. Steroids were administered and there was significant improvement in neurological functions within a short span of days. Patients' functions in the affected limb were normal in one month. Our case was interesting since it is the first such case in the literature where lightning has caused such a rare instance of unilateral pan-brachial plexus lesion. Such cases when seen, raises the possibility of more common central nervous system pathology rather than peripheral involvement. However, such lesions can be purely benign forms of peripheral nerve neuropraxia, which can be managed by steroid treatment without leaving any long-term neurological deficits.

Cutaneous Surgical Denervation: A Method for Testing the Requirement for Nerves in Mouse Models of Skin Disease.

PubMed

Peterson, Shelby C; Brownell, Isaac; Wong, Sunny Y

2016-06-26

Cutaneous somatosensory nerves function to detect diverse stimuli that act upon the skin. In addition to their established sensory roles, recent studies have suggested that nerves may also modulate skin disorders including atopic dermatitis, psoriasis and cancer. Here, we describe protocols for testing the requirement for nerves in maintaining a cutaneous mechanosensory organ, the touch dome (TD). Specifically, we discuss methods for genetically labeling, harvesting and visualizing TDs by whole-mount staining, and for performing unilateral surgical denervation on mouse dorsal back skin. Together, these approaches can be used to directly compare TD morphology and gene expression in denervated as well as sham-operated skin from the same animal. These methods can also be readily adapted to examine the requirement for nerves in mouse models of skin pathology. Finally, the ability to repeatedly sample the skin provides an opportunity to monitor disease progression at different stages and times after initiation.

On the impact of examiners on latencies and amplitudes in cervical and ocular vestibular-evoked myogenic potentials evaluated over a large sample (N = 1,038).

PubMed

Ertl, Matthias; Boegle, R; Kirsch, V; Dieterich, M

2016-02-01

Vestibular-evoked myogenic potentials (VEMPs) are frequently used in the clinical diagnosis and research of vertigo syndromes. Altered latencies or amplitudes are typically interpreted as an indication of disturbance in the processing of vestibular stimuli along the otolithic pathways. Correct interpretation, however, can be difficult as VEMP amplitudes can vary greatly across subjects and across laboratories, likely because they are very sensitive to measurement conditions. Here, we attempted to quantify the impact of examiner differences on VEMP data. We collected data from 1,038 people using eight different experimental examiners, and investigated the effect of examiner on VEMP latencies and amplitudes. We found that the examiner collecting the data had a strong effect on outcome measures with significant differences (p < 0.001) in cVEMP and oVEMP latencies and in oVEMP amplitudes. No significant differences between examiners were found for the cVEMP amplitudes. When we compared the healthy and pathological sides of patients with a clinically diagnosed unilateral disease, no significant differences between sides were found. Given our results and the results reported in the literature, we conclude that the signal features of VEMPs are very sensitive to variables that may be influenced by the examiner. The field should therefore work on a better standard for VEMP recordings.

Neck Proprioception Shapes Body Orientation and Perception of Motion

PubMed Central

Pettorossi, Vito Enrico; Schieppati, Marco

2014-01-01

This review article deals with some effects of neck muscle proprioception on human balance, gait trajectory, subjective straight-ahead (SSA), and self-motion perception. These effects are easily observed during neck muscle vibration, a strong stimulus for the spindle primary afferent fibers. We first remind the early findings on human balance, gait trajectory, SSA, induced by limb, and neck muscle vibration. Then, more recent findings on self-motion perception of vestibular origin are described. The use of a vestibular asymmetric yaw-rotation stimulus for emphasizing the proprioceptive modulation of motion perception from the neck is mentioned. In addition, an attempt has been made to conjointly discuss the effects of unilateral neck proprioception on motion perception, SSA, and walking trajectory. Neck vibration also induces persistent aftereffects on the SSA and on self-motion perception of vestibular origin. These perceptive effects depend on intensity, duration, side of the conditioning vibratory stimulation, and on muscle status. These effects can be maintained for hours when prolonged high-frequency vibration is superimposed on muscle contraction. Overall, this brief outline emphasizes the contribution of neck muscle inflow to the construction and fine-tuning of perception of body orientation and motion. Furthermore, it indicates that tonic neck-proprioceptive input may induce persistent influences on the subject’s mental representation of space. These plastic changes might adapt motion sensitiveness to lasting or permanent head positional or motor changes. PMID:25414660

Neck proprioception shapes body orientation and perception of motion.

PubMed

Pettorossi, Vito Enrico; Schieppati, Marco

2014-01-01

This review article deals with some effects of neck muscle proprioception on human balance, gait trajectory, subjective straight-ahead (SSA), and self-motion perception. These effects are easily observed during neck muscle vibration, a strong stimulus for the spindle primary afferent fibers. We first remind the early findings on human balance, gait trajectory, SSA, induced by limb, and neck muscle vibration. Then, more recent findings on self-motion perception of vestibular origin are described. The use of a vestibular asymmetric yaw-rotation stimulus for emphasizing the proprioceptive modulation of motion perception from the neck is mentioned. In addition, an attempt has been made to conjointly discuss the effects of unilateral neck proprioception on motion perception, SSA, and walking trajectory. Neck vibration also induces persistent aftereffects on the SSA and on self-motion perception of vestibular origin. These perceptive effects depend on intensity, duration, side of the conditioning vibratory stimulation, and on muscle status. These effects can be maintained for hours when prolonged high-frequency vibration is superimposed on muscle contraction. Overall, this brief outline emphasizes the contribution of neck muscle inflow to the construction and fine-tuning of perception of body orientation and motion. Furthermore, it indicates that tonic neck-proprioceptive input may induce persistent influences on the subject's mental representation of space. These plastic changes might adapt motion sensitiveness to lasting or permanent head positional or motor changes.

Disability perception in Menière's disease: when, how much and why?

PubMed

Soto-Varela, Andres; Huertas-Pardo, Belen; Gayoso-Diz, Pilar; Santos-Perez, Sofia; Sanchez-Sellero, Ines

2016-04-01

The purpose of the study was to evaluate self-perceived handicap in patients with definite Menière's disease (MD). A cross-sectional study was conducted. To examine the self-perception of disability, participants completed a DHI (Dizziness Handicap Inventory). Parameters compared with DHI scores: sex, age, unilateral/bilateral affectation, time elapsed since the onset of symptoms, pure-tone average (PTA), stages of MD, audiometric change (last 6 months), PTA in low frequencies (PTAl) and audiometric change in PTAl, subjective perception of fluctuating hearing threshold, tinnitus between attacks, number of vertiginous episodes (last 6 months), time elapsed since last attack, subjective perception of instability intercrises and Tumarkin attacks. 90 patients were included; they completed a total of 104 questionnaires. DHI scores ranged from 2 to 100 (average: 47.08, SD 24.45). In 29 cases (27.9 %) the disability perception was mild, in 43 (41.3 %) moderate, and in 32 (30.8 %) severe. Correlation between disability perception and some vestibular symptoms was found: number of typical attacks (last 6 months), time elapsed since last attack, instability intercrises and Tumarkin attacks. No relationship was found with the rest of variables. Disability perception in patients with MD depends primarily on vestibular symptoms (particularly, instability and frequency of attacks). So, we suggest to design a new staging system of MD taking into account both auditory criteria and also vestibular symptoms.

Early uneven ear input induces long-lasting differences in left-right motor function.

PubMed

Antoine, Michelle W; Zhu, Xiaoxia; Dieterich, Marianne; Brandt, Thomas; Vijayakumar, Sarath; McKeehan, Nicholas; Arezzo, Joseph C; Zukin, R Suzanne; Borkholder, David A; Jones, Sherri M; Frisina, Robert D; Hébert, Jean M

2018-03-01

How asymmetries in motor behavior become established normally or atypically in mammals remains unclear. An established model for motor asymmetry that is conserved across mammals can be obtained by experimentally inducing asymmetric striatal dopamine activity. However, the factors that can cause motor asymmetries in the absence of experimental manipulations to the brain remain unknown. Here, we show that mice with inner ear dysfunction display a robust left or right rotational preference, and this motor preference reflects an atypical asymmetry in cortico-striatal neurotransmission. By unilaterally targeting striatal activity with an antagonist of extracellular signal-regulated kinase (ERK), a downstream integrator of striatal neurotransmitter signaling, we can reverse or exaggerate rotational preference in these mice. By surgically biasing vestibular failure to one ear, we can dictate the direction of motor preference, illustrating the influence of uneven vestibular failure in establishing the outward asymmetries in motor preference. The inner ear-induced striatal asymmetries identified here intersect with non-ear-induced asymmetries previously linked to lateralized motor behavior across species and suggest that aspects of left-right brain function in mammals can be ontogenetically influenced by inner ear input. Consistent with inner ear input contributing to motor asymmetry, we also show that, in humans with normal ear function, the motor-dominant hemisphere, measured as handedness, is ipsilateral to the ear with weaker vestibular input.

Preoperative Visualization of Cranial Nerves in Skull Base Tumor Surgery Using Diffusion Tensor Imaging Technology.

PubMed

Ma, Jun; Su, Shaobo; Yue, Shuyuan; Zhao, Yan; Li, Yonggang; Chen, Xiaochen; Ma, Hui

2016-01-01

To visualize cranial nerves (CNs) using diffusion tensor imaging (DTI) with special parameters. This study also involved the evaluation of preoperative estimates and intraoperative confirmation of the relationship between nerves and tumor by verifying the accuracy of visualization. 3T magnetic resonance imaging scans including 3D-FSPGR, FIESTA, and DTI were used to collect information from 18 patients with skull base tumor. DTI data were integrated into the 3D slicer for fiber tracking and overlapped anatomic images to determine course of nerves. 3D reconstruction of tumors was achieved to perform neighboring, encasing, and invading relationship between lesion and nerves. Optic pathway including the optic chiasm could be traced in cases of tuberculum sellae meningioma and hypophysoma (pituitary tumor). The oculomotor nerve, from the interpeduncular fossa out of the brain stem to supraorbital fissure, was clearly visible in parasellar meningioma cases. Meanwhile, cisternal parts of trigeminal nerve and abducens nerve, facial nerve were also imaged well in vestibular schwannomas and petroclival meningioma cases. The 3D-spatial relationship between CNs and skull base tumor estimated preoperatively by tumor modeling and tractography corresponded to the results determined during surgery. Supported by DTI and 3D slicer, preoperative 3D reconstruction of most CNs related to skull base tumor is feasible in pathological circumstances. We consider DTI Technology to be a useful tool for predicting the course and location of most CNs, and syntopy between them and skull base tumor.

Recovery trajectories of vestibulopathic subjects after perturbations during locomotion

NASA Technical Reports Server (NTRS)

Wall, C. 3rd; Oddsson, L. I.; Patronik, N.; Sienko, K.; Kentala, E.

2002-01-01

We compared the mediolateral (M/L) responses to perturbations during locomotion of vestibulopathic (VP) subjects to those of controls. Eight subjects with unilateral vestibular loss (100% Reduced Vestibular Response from the caloric test) resulting from surgery for vestibular schwannoma and 11 controls were selected for this study. Despite their known vestibulopathy, all VP subjects scored within the normal range on computerized dynamic posturography Sensory Organization Tests. During gait, subjects were given surface perturbations of the right support-phase foot in two possible directions (forward-right and backward-left) at two possible magnitudes (5 and 10 cm) that were randomly mixed with trials having no perturbations. M/L stability was quantified by estimating the length of the M/L moment arm between the support foot and the trunk, and the M/L accelerations of the sternum and the head. The VP group had greater changes (p < 0.05) in their moment arm responses compared to controls. The number of steps that it took for the moment arm oscillations to return to normal and the variability in the moment arms were greater for the VP group. Differences in the sternum and head accelerations between VP and control groups were not as consistent, but there was a trend toward greater response deviations in the VP group for all 4 perturbation types. Increased response magnitude and variability of the VP group is consistent with an increase in their sensory noise of vestibular inputs due to the surgical lesion. Another possibility is a reduced sensitivity to motion inputs. This perturbation approach may prove useful for characterizing subtle vestibulopathies and similar changes in the human orientation mechanism after exposure to microgravity.

Subjective visual horizontal during follow-up after unilateral vestibular deafferentation with gentamicin.

PubMed

Tribukait, A; Bergenius, J; Brantberg, K

1998-07-01

The subjective visual horizontal (SVH) was measured by means of a small, rotatable, luminous line in darkness in the upright head and body position and at 10, 20 and 30 degrees of tilt to the right and left before, and repeatedly during a follow-up period of 1 year after intratympanic gentamicin instillations in 12 patients with recurrent vertigo attacks. This treatment caused a loss of the bithermal caloric responses on the diseased side. Shortly after treatment there was a significant tilt of SVH towards the treated side (group mean = 10.6 degrees). Repeated testing made it possible to characterize mathematically the changes with time for SVH. For the group of patients as a whole this otolithic component of vestibular compensation was best described by a power function, SVH = 8.65t(-0.16) degrees, where t is time in days after maximum tilt of SVH. After 1 year, SVH was still significantly tilted towards the treated side (group mean = 3.16 degrees). Gentamicin treatment also caused a significant reduction in the perception of head and body tilt towards the deafferented side, while the perception of tilt towards the healthy side did not show any significant changes. During follow-up there was a gradual improvement in the perception of tilt towards the treated side. However, a significant asymmetry in roll-tilt perception was still present 1 year after deafferentation. There was no correlation between SVH in the upright position and roll-tilt perception, suggesting that these parameters are to some extent dependent on different afferent input from the vestibular organ. They were also found to be complementary for the detection of vestibular disturbance.

Conservative management of vestibular schwannoma--a prospective cohort study: treatment, symptoms, and quality of life.

PubMed

Breivik, Cathrine Nansdal; Varughese, Jobin K; Wentzel-Larsen, Tore; Vassbotn, Flemming; Lund-Johansen, Morten

2012-05-01

One hundred ninety-three patients with sporadic unilateral vestibular schwannoma given conservative management were enrolled in a prospective study. To evaluate the efficacy of conservative management and to determine the effect of an initial conservative management on the quality of life (QOL) and severity of audio vestibular symptoms. The patients underwent magnetic resonance imaging scans, clinical examination, and QOL assessment by 2 validated questionnaires, the Short Form-36 (SF-36) and Glasgow Benefit Inventory (GBI). Using regression analysis of clustered data, we analyzed possible associations between tumor growth and symptoms and tested whether our earlier finding that vertigo is associated with reduced QOL could be verified. The median follow-up time was 43 months (range, 9-115 months; SD, 21.48 months). Results are based on 703 clinical controls and 642 (SF-36) and 638 (GBI) questionnaires. Seven patients were lost to follow-up. Approximately 40% of patients were in need of treatment during follow-up. We found a statistically significant association between tinnitus and vertigo and tumor growth. Vertigo was found to significantly reduce QOL. There was a significant drop in the Social Function subscales of both SF-36 and GBI, possibly attributable to progressive hearing loss. Otherwise, there was no overall trend toward any change in QOL during the observation period. In addition, QOL seemed to be little affected by treatment. There was a small but statistically significant improvement in vestibular complaints and no change in the occurrence of tinnitus. Except for hearing loss caused by surgery, treatment did not affect symptoms or QOL significantly. Growth was associated with the occurrence of tinnitus and balance problems.

[Influence of trigeminal nerve lesion on facial growth: study of two cases of Goldenhar syndrome].

PubMed

Darris, Pierre; Treil, Jacques; Marchal-Sixou, Christine; Baron, Pascal

2015-06-01

This cases report confirms the hypothesis that embryonic and maxillofacial growth are influenced by the peripheral nervous system, including the trigeminal nerve (V). So, it's interesting to use the stigma of the trigeminal nerve as landmarks to analyze the maxillofacial volume and understand its growth. The aim of this study is to evaluate the validity of the three-dimensional cephalometric analysis of Treil based on trigeminal landmarks. The first case is a caucasian female child with Goldenhar syndrome. The second case is a caucasian male adult affected by the same syndrome. In both cases, brain MRI showed an unilateral trigeminal nerve lesion, ipsilateral to the facial dysmorphia. The results of this radiological study tend to prove the primary role of the trigeminal nerve in craniofacial growth. These cases demonstrate the validity of the theory of Moss. They are one of anatomo-functional justifications of the three-dimensional cephalometric biometry of Treil based on trigeminal nerve landmarks. © EDP Sciences, SFODF, 2015.

Complete dislocation of the ulnar nerve at the elbow: a protective effect against neuropathy?

PubMed

Leis, A Arturo; Smith, Benn E; Kosiorek, Heidi E; Omejec, Gregor; Podnar, Simon

2017-08-01

Recurrent complete ulnar nerve dislocation has been perceived as a risk factor for development of ulnar neuropathy at the elbow (UNE). However, the role of dislocation in the pathogenesis of UNE remains uncertain. We studied 133 patients with complete ulnar nerve dislocation to determine whether this condition is a risk factor for UNE. In all, the nerve was palpated as it rolled over the medial epicondyle during elbow flexion. Of 56 elbows with unilateral dislocation, UNE localized contralaterally in 17 elbows (30.4%) and ipsilaterally in 10 elbows (17.9%). Of 154 elbows with bilateral dislocation, 26 had UNE (16.9%). Complete dislocation decreased the odds of having UNE by 44% (odds ratio = 0.475; P =  0.028), and was associated with less severe UNE (P = 0.045). UNE occurs less frequently and is less severe on the side of complete dislocation. Complete dislocation may have a protective effect on the ulnar nerve. Muscle Nerve 56: 242-246, 2017. © 2016 Wiley Periodicals, Inc.

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). Copyright © 2013 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

The Experience of Soviet Medicine in the Great Patriotic War 1941-1945,

DTIC Science & Technology

1980-02-06

mainly during shock/counterblow of brain against the contradictory/opposite walls of skull. Subliminal stimulations cause system resFonse of IX-X nerve...the same effect was cbtained during the stimulation of external auditory passage and muccsa of ncse. Vith sharp pressure to the region of the inguinal...zone of stimulation are invclved the centers cf tespcral region in combination with vestibular, auditory or gustatory aura. At the same time the

Schwannomatosis on a single foot: a case report.

PubMed

Min, Hak-Jin; Kim, Ki Chun; Jun, Sung Han; Lee, Young Gun

2015-06-01

Schwannomatosis has been recently recognized as the third major type of neurofibromatosis. It causes multiple schwannomas without the vestibular tumors that are diagnostic of neurofibromatosis type 2. Schwannoma is rarely found in the foot, and it is still rarer to find multiple schawannomas in a single peripheral nerve on the foot. In this article, we describe a case of schwannomatosis case on a single foot. Case report, Level IV. © 2014 The Author(s).

Place of Gamma Knife Stereotactic Radiosurgery in Grade 4 Vestibular Schwannoma Based on Case Series of 86 Patients with Long-Term Follow-Up.

PubMed

Lefranc, Michel; Da Roz, Leila Maria; Balossier, Anne; Thomassin, Jean Marc; Roche, Pierre Hugue; Regis, Jean

2018-06-01

Grade IV vestibular schwannoma (Koos classification) is generally considered to be an indication for microsurgical resection or combined radiosurgery-microsurgery. However, the place of Gamma Knife stereotactic surgery (GK-SRS), either as first-line treatment or when progression of residual tumor compresses the brainstem, has not been clearly evaluated. This article reports the results of a large case series of patients with grade 4 vestibular schwannoma treated by GK-SRS. All consecutive patients with grade IV vestibular schwannoma treated by GK-SRS in our department between 1996 and 2011 with a minimum follow-up of 3 years were included in this study. 86 patients were treated by GK-SRS with a minimum follow-up of 3 years. Mean follow-up was 6.2 years (3-16 years). The mean age of the patients at the time of GK-SRS was 54.6 years (range: 23-84) and the sex ratio was 0.6. At the time of radiosurgery, no patient presented brainstem dysfunction prior to GK-SRS. 38 patients had functional hearing before treatment. One patient presented mild trigeminal neuralgia before GK-SRS. Tumor control with no clinical deterioration was obtained in 78 patients (90.7%). No radiation-induced brainstem or cranial nerve toxicity was observed in any of these patients. Functional hearing was maintained in 25 patients. 8 (9.3%) patients presented tumor growth and required microsurgical resection in 7 cases and ventricular shunt in 1 case. On the basis of this large series, GK-SRS appears to be a safe and effective treatment option for grade IV vestibular schwannoma for patients with no signs of brainstem dysfunction. Copyright © 2018 Elsevier Inc. All rights reserved.

Effects of 17beta-estradiol on glutamate synaptic transmission and neuronal excitability in the rat medial vestibular nuclei.

PubMed

Grassi, S; Frondaroli, A; Scarduzio, M; Dutia, M B; Dieni, C; Pettorossi, V E

2010-02-17

We investigated the effects of the neurosteroid 17beta-estradiol (E(2)) on the evoked and spontaneous activity of rat medial vestibular nucleus (MVN) neurons in brainstem slices. E(2) enhances the synaptic response to vestibular nerve stimulation in type B neurons and depresses the spontaneous discharge in both type A and B neurons. The amplitude of the field potential, as well as the excitatory post-synaptic potential (EPSP) and current (EPSC), in type B neurons, are enhanced by E(2). Both effects are long-term phenomena since they outlast the drug washout. The enhancement of synaptic response is mainly due to facilitation of glutamate release mediated by pre-synaptic N-methyl-D-aspartate receptors (NMDARs), since the reduction of paired pulse ratio (PPR) and the increase of miniature EPSC frequency after E(2) are abolished under D-(-)-2-amino-5-phosphonopentanoic acid (AP-5). E(2) also facilitates post-synaptic NMDARs, but it does not affect directly alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) and group I-metabotropic glutamate receptors (mGluRs-I). In contrast, the depression of the spontaneous discharge of type A and type B neurons appears to depend on E(2) modulation of intrinsic ion conductances, as the effect remains after blockade of glutamate, GABA and glycine receptors (GlyRs). The net effect of E(2) is to enhance the signal-to-noise ratio of the synaptic response in type B neurons, relative to resting activity of all MVN neurons. These findings provide evidence for a novel potential mechanism to modulate the responsiveness of vestibular neurons to afferent inputs, and so regulate vestibular function in vivo.

Repair of facial nerve defects with decellularized artery allografts containing autologous adipose-derived stem cells in a rat model.

PubMed

Sun, Fei; Zhou, Ke; Mi, Wen-Juan; Qiu, Jian-Hua

2011-07-20

The purpose of this study was to investigate the effects of a decellularized artery allograft containing autologous adipose-derived stem cells (ADSCs) on an 8-mm facial nerve branch lesion in a rat model. At 8 weeks postoperatively, functional evaluation of unilateral vibrissae movements, morphological analysis of regenerated nerve segments and retrograde labeling of facial motoneurons were all analyzed. Better regenerative outcomes associated with functional improvement, great axonal growth, and improved target reinnervation were achieved in the artery-ADSCs group (2), whereas the cut nerves sutured with artery conduits alone (group 1) achieved inferior restoration. Furthermore, transected nerves repaired with nerve autografts (group 3) resulted in significant recovery of whisking, maturation of myelinated fibers and increased number of labeled facial neurons, and the latter two parameters were significantly different from those of group 2. Collectively, though our combined use of a decellularized artery allograft with autologous ADSCs achieved regenerative outcomes inferior to a nerve autograft, it certainly showed a beneficial effect on promoting nerve regeneration and thus represents an alternative approach for the reconstruction of peripheral facial nerve defects. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

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

PubMed

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

2016-08-01

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

Comparison of Direct Side-to-End and End-to-End Hypoglossal-Facial Anastomosis for Facial Nerve Repair.

PubMed

Samii, Madjid; Alimohamadi, Maysam; Khouzani, Reza Karimi; Rashid, Masoud Rafizadeh; Gerganov, Venelin

2015-08-01

The hypoglossal facial anastomosis (HFA) is the gold standard for facial reanimation in patients with severe facial nerve palsy. The major drawbacks of the classic HFA technique are lingual morbidities due to hypoglossal nerve transection. The side-to-end HFA is a modification of the classic technique with fewer tongue-related morbidities. In this study we compared the outcome of the classic end-to-end and the direct side-to-end HFA surgeries performed at our center in regards to the facial reanimation success rate and tongue-related morbidities. Twenty-six successive cases of HFA were enrolled. In 9 of them end-to-end anastomoses were performed, and 17 had direct side-to-end anastomoses. The House-Brackmann (HB) and Pitty and Tator (PT) scales were used to document surgical outcome. The hemiglossal atrophy, swallowing, and hypoglossal nerve function were assessed at follow-up. The original pathology was vestibular schwannoma in 15, meningioma in 4, brain stem glioma in 4, and other pathologies in 3. The mean interval between facial palsy and HFA was 18 months (range: 0-60). The median follow-up period was 20 months. The PT grade at follow-up was worse in patients with a longer interval from facial palsy and HFA (P value: 0.041). The lesion type was the only other factor that affected PT grade (the best results in vestibular schwannoma and the worst in the other pathologies group, P value: 0.038). The recovery period for facial tonicity was longer in patients with radiation therapy before HFA (13.5 vs. 8.5 months) and those with a longer than 2-year interval from facial palsy to HFA (13.5 vs. 8.5 months). Although no significant difference between the side-to-end and the end-to-end groups was seen in terms of facial nerve functional recovery, patients from the side-to-end group had a significantly lower rate of lingual morbidities (tongue hemiatrophy: 100% vs. 5.8%, swallowing difficulty: 55% vs. 11.7%, speech disorder 33% vs. 0%). With the side-to-end HFA technique the functional restoration outcome is at least as good as that following the classic end-to-end HFA, but the complications related to the complete hypoglossal nerve transection can be avoided. Best results are achieved if this procedure is performed within the first 2 years after facial nerve injury. Patients with facial palsy of longer duration also have the chance for good functional restoration after HFA. Copyright © 2015 Elsevier Inc. All rights reserved.