Sample records for nas pregas vestibulares

  1. 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.

  2. [Vestibular compensation studies]. [Vestibular Compensation and Morphological Studies

    NASA Technical Reports Server (NTRS)

    Perachio, Adrian A. (Principal Investigator)

    1996-01-01

    The following topics are reported: neurophysiological studies on MVN neurons during vestibular compensation; effects of spinal cord lesions on VNC neurons during compensation; a closed-loop vestibular compensation model for horizontally canal-related MVN neurons; spatiotemporal convergence in VNC neurons; contributions of irregularly firing vestibular afferents to linear and angular VOR's; application to flight studies; metabolic measures in vestibular neurons; immediate early gene expression following vestibular stimulation; morphological studies on primary afferents, central vestibular pathways, vestibular efferent projection to the vestibular end organs, and three-dimensional morphometry and imaging.

  3. Vestibular recruitment

    NASA Technical Reports Server (NTRS)

    Tsemakhov, S. G.

    1980-01-01

    Vestibular recruitment is defined through the analysis of several references. It is concluded that vestibular recruitment is an objective phenomenon which manifests itself during the affection of the vestibular receptor and thus serves as a diagnostic tool during affection of the vestibular system.

  4. 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

  5. Vestibular rehabilitation outcomes in the elderly with chronic vestibular dysfunction.

    PubMed

    Bayat, Arash; Pourbakht, Akram; Saki, Nader; Zainun, Zuraida; Nikakhlagh, Soheila; Mirmomeni, Golshan

    2012-11-01

    Chronic vestibular dysfunction is a frustrating problem in the elderly and can have a tremendous impact on their life, but only a few studies are available. Vestibular rehabilitation therapy (VRT) is an important therapeutic option for the neuro-otologist in treating patients with significant balance deficits. The purpose of this study was to assess the effect of vestibular rehabilitation on dizziness in elderly patients with chronic vestibular dysfunction. A total of 33 patients older than 60 years with chronic vestibular dysfunction were studied. Clinical and objective vestibular tests including videonystagmography (VNG) and dizziness handicap inventory (DHI) were carried out at their first visit, 2 weeks, and 8 weeks post-VRT. The VRT exercises were performed according to Cawthorne and Cooksey protocols. Oculomotor assessments were within normal limits in all patients. Nineteen patients (57.57%) showed abnormal canal paralysis on caloric testing which at follow-up sessions; CP values were decreased remarkably after VRT exercises. We found a significant improvement between pre-VRT and post-VRT total DHI scores (P < 0.001). This improvement was most prominent in functional subscore. Our study demonstrated that VRT is an effective therapeutic method for elderly patients with chronic vestibular dysfunction.

  6. Top-down approach to vestibular compensation: translational lessons from vestibular rehabilitation

    PubMed Central

    Balaban, Carey D.; Hoffer, Michael E.; Gottshall, Kim R.

    2012-01-01

    This review examines vestibular compensation and vestibular rehabilitation from a unified translational research perspective. Laboratory studies illustrate neurobiological principles of vestibular compensation at the molecular, cellular and systems levels in animal models that inform vestibular rehabilitation practice. However, basic research has been hampered by an emphasis on ‘naturalistic’ recovery, with time after insult and drug interventions as primary dependent variables. The vestibular rehabilitation literature, on the other hand, provides information on how the degree of compensation can be shaped by specific activity regimens. The milestones of the early spontaneous static compensation mark the re-establishment of static gaze stability, which provides a common coordinate frame for the brain to interpret residual vestibular information in the context of visual, somatosensory and visceral signals that convey gravitoinertial information. Stabilization of the head orientation and the eye orientation (suppression of spontaneous nystagmus) appear to be necessary by not sufficient conditions for successful rehabilitation, and define a baseline for initiating retraining. The lessons from vestibular rehabilitation in animal models offer the possibility of shaping the recovery trajectory to identify molecular and genetic factors that can improve vestibular compensation. PMID:22981400

  7. [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.

  8. Vestibular-evoked myogenic potential in patients with unilateral vestibular neuritis: abnormal VEMP and its recovery.

    PubMed

    Ochi, Kentaro; Ohashi, Toru; Watanabe, Shoji

    2003-02-01

    The incidence of inferior vestibular nerve disorders in patients suffering from unilateral vestibular neuritis and the recovery of these disorders were evaluated by monitoring the vestibular-evoked myogenic potential (VEMP). Eight patients ranged from 21 to 73 years that suffered from unilateral vestibular neuritis underwent VEMP and caloric testing. Abnormal VEMP was observed in two of the eight patients with unilateral vestibular neuritis. Two patients were diagnosed as having an inferior vestibular nerve disorder. One of these patients showed recovery of the inferior vestibular nerve function as assessed by the VEMP. Disorders of the inferior vestibular nerve function and their recovery was confirmed by our current results. The time course of recoveries of the superior and inferior vestibular nerve systems were similar in the two patients.

  9. [Effectiveness of Self-efficacy Promoting Vestibular Rehabilitation Program for Patients with Vestibular Hypofunction].

    PubMed

    Lee, Hyun Jung; Choi-Kwon, Smi

    2016-10-01

    In this study an examination was done of the effect of self-efficacy promoting vestibular rehabilitation (S-VR) on dizziness, exercise selfefficacy, adherence to vestibular rehabilitation (VR), subjective and objective vestibular function, vestibular compensation and the recurrence of dizziness in patients with vestibular hypofunction. This was a randomized controlled study. Data were collected 3 times at baseline, 4 and 8 weeks after beginning the intervention. Outcome measures were level of dizziness, exercise self-efficacy, and level of adherence to VR. Subjective and objective vestibular function, vestibular compensation and the recurrence of dizziness were also obtained. Data were analyzed using Windows SPSS 21.0 program. After 4 weeks of S-VR, there was no difference between the groups for dizziness, subjective and objective vestibular functions. However, exercise self-efficacy and adherence to VR were higher in the experimental group than in the control group. After 8 weeks of S-VR, dizziness (p=.018) exercise self-efficacy (p<.001), adherence to VR (p<.001), total-dizziness handicap inventory (DHI) (p=.012), vision analysis ratio (p=.046) in the experimental group differ significantly from that of the control group. The number of patients with recurring dizziness were higher in the control group than in the experimental group (p<.001). The results indicate that continuous 8 weeks of S-VR is effective in reducing dizziness, and improving exercise self-efficacy, subjective vestibular function and adherence to VR. Objective vestibular function and vestibular compensation were also improved in the experimental group at the end of 8 weeks of S-VR.

  10. Neural Correlates of Sensory Substitution in Vestibular Pathways Following Complete Vestibular Loss

    PubMed Central

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

    2012-01-01

    Sensory substitution is the term typically used in reference to sensory prosthetic devices designed to replace input from one defective modality with input from another modality. Such devices allow an alternative encoding of sensory information that is no longer directly provided by the defective modality in a purposeful and goal-directed manner. The behavioral recovery that follows complete vestibular loss is impressive and has long been thought to take advantage of a natural form of sensory substitution in which head motion information is no longer provided by vestibular inputs, but instead by extra-vestibular inputs such as proprioceptive and motor efference copy signals. Here we examined the neuronal correlates of this behavioral recovery after complete vestibular loss in alert behaving monkeys (Macaca mulata). We show for the first time that extra-vestibular inputs substitute for the vestibular inputs to stabilize gaze at the level of single neurons in the VOR premotor circuitry. The summed weighting of neck proprioceptive and efference copy information was sufficient to explain simultaneously observed behavioral improvements in gaze stability. Furthermore, by altering correspondence between intended and actual head movement we revealed a four-fold increase in the weight of neck motor efference copy signals consistent with the enhanced behavioral recovery observed when head movements are voluntary versus unexpected. Thus, taken together our results provide direct evidence that the substitution by extra-vestibular inputs in vestibular pathways provides a neural correlate for the improvements in gaze stability that are observed following the total loss of vestibular inputs. PMID:23077054

  11. Aging of vestibular function evaluated using correlational vestibular autorotation test

    PubMed Central

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

    2014-01-01

    Background Imbalance from degeneration of vestibular end organs is a common problem in the elderly. However, the decline of vestibular function with aging was revealed in few vestibular function tests such as vestibular autorotation test (VAT). In the current VAT, there are drawbacks of poor test–retest reliability, slippage of the sensor at high-speed rotations, and limited data about the effect of aging. We developed a correlational-VAT (cVAT) system that included a small, light sensor (less than 20 g) with wireless data transmission technique to evaluate the aging of vestibular function. Material and methods We enrolled 53 healthy participants aged between 25 and 75 years and divided them into five age groups. The test conditions were vertical and horizontal head autorotations of frequencies from 0 to 3 Hz with closed eyes or open eyes. The cross-correlation coefficient (CCC) between eye velocity and head velocity was obtained for the head autorotations between 1 Hz and 3 Hz. The mean of the CCCs was used to represent the vestibular function. Results Age was significantly and negatively correlated with the mean CCC for all test conditions, including horizontal or vertical autorotations with open eyes or closed eyes (P<0.05). The mean CCC with open eyes declined significantly at 55–65 years old and the mean CCC with closed eyes declined significantly at 65–75 years old. Conclusion Vestibular function evaluated using mean CCC revealed a decline with age, and the function of visual-vestibulo-ocular reflex declined 10 years earlier than the function of vestibulo-ocular reflex. PMID:25214774

  12. 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

  13. 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

  14. 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.

  15. Review of book vestibular crises

    NASA Technical Reports Server (NTRS)

    Blagoveshchenskaya, N. S.

    1980-01-01

    The etiology, pathogenesis, clinical practice, treatment and rehabilitation of patients with vestibular crises is discussed. Classifications for vestibular disorders are given. Information on the frequency of vestibular crises is given.

  16. Adaptation to vestibular disorientation. XII, Habituation of vestibular responses : an overview.

    DOT National Transportation Integrated Search

    1974-03-01

    Vestibular and visual mechanisms are critical sensing systems in spatial orientation and in spatial disorientation. In aviation or space environments in particular, the role of the vestibular system is central to the problems of spatial disorientatio...

  17. 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.

  18. The Association Between Vestibular Physical Examination, Vertigo Questionnaires, and the Electronystagmography in Patients With Vestibular Symptoms.

    PubMed

    Gofrit, Shany G; Mayler, Yulia; Eliashar, Ron; Bdolah-Abram, Tali; Ilan, Ophir; Gross, Menachem

    2017-04-01

    Dizziness makes up a diagnostic and treatment challenge. The diagnostic accuracy of the medical history and vestibular physical examination in cases of vestibular symptoms is not clear. The aim of this study is to determine the association between vestibular physical examination, vestibular questionnaires, and electronystagmography (ENG) test in patients with vestibular symptoms. This is a prospective study of 135 adults with vestibular symptoms. The subjects underwent targeted physical examination and filled vestibular questionnaires, including the Dizziness Handicap Inventory (DHI), before ENG testing. The results of the physical examination and questionnaires were compared with the final ENG findings. Of patients who had normal ENG results, 32.1% (17/52) showed abnormal physical examination, and 48.8% (40/82) of the patient who had normal physical examination showed abnormal ENG results ( P = .46). Among patients with severe disability by DHI, 46.4% (13/28) had an abnormal ENG, and 42.9% (12/28) had a normal ENG ( P = .39). This study did not demonstrate association between vestibular physical examination, vestibular questionnaires, and ENG results. Although history (augmented by questionnaires) and physical examination are the initial steps in the evaluation of vertigo, the current study suggests that they should be complemented by objective testing for evaluation of inner ear origin of vertigo.

  19. Vestibular Findings in Military Band Musicians

    PubMed Central

    Zeigelboim, Bianca Simone; Gueber, Crislaine; Silva, Thanara Pruner da; Liberalesso, Paulo Breno Noronha; Gonçalves, Claudia Giglio de Oliveira; Faryniuk, João Henrique; Marques, Jair Mendes; Jurkiewicz, Ari Leon

    2014-01-01

    Introduction Exposure to music is the subject of many studies because it is related to an individual's professional and social activities. Objectives Evaluate the vestibular behavior in military band musicians. Methods A retrospective cross-sectional study was performed. Nineteen musicians with ages ranging from 21 to 46 years were evaluated (average = 33.7 years and standard deviation = 7.2 years). They underwent anamnesis and vestibular and otolaryngologic evaluation through vectoelectronystagmography. Results The most evident otoneurologic symptoms in the anamnesis were tinnitus (84.2%), hearing difficulties (47.3%), dizziness (36.8%), headache (26.3%), intolerance to intense sounds (21.0%), and earache (15.7%). Seven musicians (37.0%) showed vestibular abnormality, which occurred in the caloric test. The abnormality was more prevalent in the peripheral vestibular system, and there was a predominance of irritative peripheral vestibular disorders. Conclusion The alteration in vestibular exam occurred in the caloric test (37.0%). There were changes in the prevalence of peripheral vestibular system with a predominance of irritative vestibular dysfunction. Dizziness was the most significant symptom for the vestibular test in correlation with neurotologic symptoms. The present study made it possible to verify the importance of the labyrinthine test, which demonstrates that this population should be better studied because the systematic exposure to high sound pressure levels may cause major vestibular alterations. PMID:25992076

  20. International survey of vestibular rehabilitation therapists by the Barany Society Ad Hoc Committee on Vestibular Rehabilitation Therapy.

    PubMed

    Cohen, Helen S; Gottshall, Kim R; Graziano, Mariella; Malmstrom, Eva-Maj; Sharpe, Margaret H

    2009-01-01

    The goal of this study was to determine how occupational and physical therapists learn about vestibular rehabilitation therapy, their educational backgrounds, referral patterns, and their ideas about entry-level and advanced continuing education in vestibular rehabilitation therapy. The Barany Society Ad Hoc Committee for Vestibular Rehabilitation Therapy invited therapists around the world to complete an E-mail survey. Participants were either known to committee members or other Barany Society members, known to other participants, identified from their self-listings on the Internet, or volunteered after reading notices published in publications read by therapists. Responses were received from 133 therapists in 19 countries. They had a range of educational backgrounds, practice settings, and referral patterns. Few respondents had had any training about vestibular rehabilitation during their professional entry-level education. Most respondents learned about vestibular rehabilitation from continuing education courses, interactions with their colleagues, and reading. All of them endorsed the concept of developing standards and educating therapists about vestibular anatomy and physiology, vestibular diagnostic testing, vestibular disorders and current intervention strategies. Therefore, the Committee recommends the development of international standards for education and practice in vestibular rehabilitation therapy.

  1. Vestibular signals in the parasolitary nucleus.

    PubMed

    Barmack, N H; Yakhnitsa, V

    2000-06-01

    Vestibular primary afferents project to secondary vestibular neurons located in the vestibular complex. Vestibular primary afferents also project to the uvula-nodulus of the cerebellum where they terminate on granule cells. In this report we describe the physiological properties of neurons in a "new" vestibular nucleus, the parasolitary nucleus (Psol). This nucleus consists of 2,300 GABAergic neurons that project onto the ipsilateral inferior olive (beta-nucleus and dorsomedial cell column) as well as the nucleus reticularis gigantocellularis. These olivary neurons are the exclusive source of vestibularly modulated climbing fiber inputs to the cerebellum. We recorded the activity of Psol neurons during natural vestibular stimulation in anesthetized rabbits. The rabbits were placed in a three-axis rate table at the center of a large sphere, permitting vestibular and optokinetic stimulation. We recorded from 74 neurons in the Psol and from 23 neurons in the regions bordering Psol. The activity of 72/74 Psol neurons and 4/23 non-Psol neurons was modulated by vestibular stimulation in either the pitch or roll planes but not the horizontal plane. Psol neurons responded in phase with ipsilateral side-down head position or velocity during sinusoidal stimulation. Approximately 80% of the recorded Psol neurons responded to static roll-tilt. The optimal response planes of evoked vestibular responses were inferred from measurement of null planes. Optimal response planes usually were aligned with the anatomical orientation of one of the two ipsilateral vertical semicircular canals. The frequency dependence of null plane measurements indicated a convergence of vestibular information from otoliths and semicircular canals. None of the recorded neurons evinced optokinetic sensitivity. These results are consistent with the view that Psol neurons provide the vestibular signals to the inferior olive that eventually reached the cerebellum in the form of modulated climbing fiber

  2. Interaction of somatoform and vestibular disorders

    PubMed Central

    Best, C; Eckhardt‐Henn, A; Diener, G; Bense, S; Breuer, P; Dieterich, M

    2006-01-01

    Background The high coincidence of organic vestibular and somatoform vertigo syndromes has appeared to support pathogenic models showing a strong linkage between them. It was hypothesised that a persisting vestibular dysfunction causes the development of anxiety disorders. Objective To determine the relation between vestibular deficits and somatoform vertigo disorders in an interdisciplinary prospective study. Methods Participants were divided into eight diagnostic groups: healthy volunteers (n = 26) and patients with benign paroxysmal positioning vertigo (BPPV, n = 11), vestibular neuritis (n = 11), Menière's disease (n = 7), vestibular migraine (n = 15), anxiety (n = 23), depression (n = 12), or somatoform disorders (n = 22). Neuro‐otological diagnostic procedures included electro‐oculography with rotatory and caloric testing, orthoptic examination with measurements of subjective visual vertical (SVV) and ocular torsion, and a neurological examination. Psychosomatic diagnostic procedures comprised interviews and psychometric instruments. Results Patients with BPPV (35.3%) and with vestibular neuritis (52.2%) had pathological test values on caloric irrigation (p<0.001). Otolith dysfunction with pathological tilts of SVV and ocular torsion was found only in patients with vestibular neuritis (p<0.001). Patients with Menière's disease, vestibular migraine, and psychiatric disorders showed normal parameters for vestibular testing but pathological values for psychometric measures. There was no correlation between pathological neurological and pathological psychometric parameters. Conclusions High anxiety scores are not a result of vestibular deficits or dysfunction. Patients with Menière's disease and vestibular migraine but not vestibular deficits showed the highest psychiatric comorbidity. Thus the course of vertigo syndromes and the possibility of a pre‐existing psychopathological personality should be considered pathogenic

  3. Vestibular migraine: who is the patient?

    PubMed

    Colombo, Bruno; Teggi, Roberto

    2017-05-01

    Vestibular migraine has been classified as a specific entity in which vestibular symptomatology is defined as part of the migrainous disorder. New and appropriate diagnostic criteria have been proposed by the Barany and International Headache Societies. The diagnosis of vestibular migraine mainly depends on the patient history. The NIVE project is a prospectic multicentric study on vestibular migraine. The aim of this project is to evaluate demographics, epidemiology, clinical manifestations of migraine and vertigo in a large cohort of Caucasian patients affected by vestibular migraine.

  4. Vestibular blueprint in early vertebrates.

    PubMed

    Straka, Hans; Baker, Robert

    2013-11-19

    Central vestibular neurons form identifiable subgroups within the boundaries of classically outlined octavolateral nuclei in primitive vertebrates that are distinct from those processing lateral line, electrosensory, and auditory signals. Each vestibular subgroup exhibits a particular morpho-physiological property that receives origin-specific sensory inputs from semicircular canal and otolith organs. Behaviorally characterized phenotypes send discrete axonal projections to extraocular, spinal, and cerebellar targets including other ipsi- and contralateral vestibular nuclei. The anatomical locations of vestibuloocular and vestibulospinal neurons correlate with genetically defined hindbrain compartments that are well conserved throughout vertebrate evolution though some variability exists in fossil and extant vertebrate species. The different vestibular subgroups exhibit a robust sensorimotor signal processing complemented with a high degree of vestibular and visual adaptive plasticity.

  5. 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.

  6. A vestibular phenotype for Waardenburg syndrome?

    NASA Technical Reports Server (NTRS)

    Black, F. O.; Pesznecker, S. C.; Allen, K.; Gianna, C.

    2001-01-01

    OBJECTIVE: To investigate vestibular abnormalities in subjects with Waardenburg syndrome. STUDY DESIGN: Retrospective record review. SETTING: Tertiary referral neurotology clinic. SUBJECTS: Twenty-two adult white subjects with clinical diagnosis of Waardenburg syndrome (10 type I and 12 type II). INTERVENTIONS: Evaluation for Waardenburg phenotype, history of vestibular and auditory symptoms, tests of vestibular and auditory function. MAIN OUTCOME MEASURES: Results of phenotyping, results of vestibular and auditory symptom review (history), results of vestibular and auditory function testing. RESULTS: Seventeen subjects were women, and 5 were men. Their ages ranged from 21 to 58 years (mean, 38 years). Sixteen of the 22 subjects sought treatment for vertigo, dizziness, or imbalance. For subjects with vestibular symptoms, the results of vestibuloocular tests (calorics, vestibular autorotation, and/or pseudorandom rotation) were abnormal in 77%, and the results of vestibulospinal function tests (computerized dynamic posturography, EquiTest) were abnormal in 57%, but there were no specific patterns of abnormality. Six had objective sensorineural hearing loss. Thirteen had an elevated summating/action potential (>0.40) on electrocochleography. All subjects except those with severe hearing loss (n = 3) had normal auditory brainstem response results. CONCLUSION: Patients with Waardenburg syndrome may experience primarily vestibular symptoms without hearing loss. Electrocochleography and vestibular function tests appear to be the most sensitive measures of otologic abnormalities in such patients.

  7. Vestibular pathways involved in cognition

    PubMed Central

    Hitier, Martin; Besnard, Stephane; Smith, Paul F.

    2014-01-01

    Recent discoveries have emphasized the role of the vestibular system in cognitive processes such as memory, spatial navigation and bodily self-consciousness. A precise understanding of the vestibular pathways involved is essential to understand the consequences of vestibular diseases for cognition, as well as develop therapeutic strategies to facilitate recovery. The knowledge of the “vestibular cortical projection areas”, defined as the cortical areas activated by vestibular stimulation, has dramatically increased over the last several years from both anatomical and functional points of view. Four major pathways have been hypothesized to transmit vestibular information to the vestibular cortex: (1) the vestibulo-thalamo-cortical pathway, which probably transmits spatial information about the environment via the parietal, entorhinal and perirhinal cortices to the hippocampus and is associated with spatial representation and self-versus object motion distinctions; (2) the pathway from the dorsal tegmental nucleus via the lateral mammillary nucleus, the anterodorsal nucleus of the thalamus to the entorhinal cortex, which transmits information for estimations of head direction; (3) the pathway via the nucleus reticularis pontis oralis, the supramammillary nucleus and the medial septum to the hippocampus, which transmits information supporting hippocampal theta rhythm and memory; and (4) a possible pathway via the cerebellum, and the ventral lateral nucleus of the thalamus (perhaps to the parietal cortex), which transmits information for spatial learning. Finally a new pathway is hypothesized via the basal ganglia, potentially involved in spatial learning and spatial memory. From these pathways, progressively emerges the anatomical network of vestibular cognition. PMID:25100954

  8. Vestibular involvement in adults with HIV/AIDS.

    PubMed

    Heinze, Barbara M; Vinck, Bart M; Hofmeyr, Louis M; Swanepoel, De Wet

    2014-04-01

    HIV/AIDS is responsible for widespread clinical manifestations involving the head, and neck. The prevalence and nature of vestibular involvement is still largely unknown. This study, aimed to describe and compare the occurrence and nature of vestibular involvement among a group of, adults infected with HIV compared to a control group. It also aimed to compare the vestibular function, of symptomatic and asymptomatic HIV positive adults who receive antiretroviral (ARV) therapies to, subjects not receiving ARV. A cross-sectional study was conducted on 53 adults (29 male, 24 female, aged 23-49 years, mean=38.5, SD=4.4) infected with HIV, compared to a control group of 38 HIV negative adults (18, male, 20 female, aged 20-49 years, mean=36.9, SD=8.2). A structured interview probed the subjective, perception of vestibular symptoms. Medical records were reviewed for CD4+ cell counts and the use of, ARV medication. An otologic assessment and a comprehensive vestibular assessment (bedside, assessments, vestibular evoked myogenic potentials, ocular motor and positional tests and bithermal, caloric irrigation) were conducted. Vestibular involvement occurred in 79.2% of subjects with HIV in all categories of disease, progression, compared to 18.4% in those without HIV. Vestibular involvement increased from 18.9% in CDC category 1 to 30.2% in category 2. Vestibular involvement was 30.1% in category 3. There were, vestibular involvement in 35.9% of symptomatic HIV positive subjects, and 41.5% in asymptomatic, HIV positive subjects. There was no significant difference in the occurrence of vestibular involvement, in subjects receiving ARV therapies compared to those not receiving ARV therapies (p=.914; chi-square, test). The odds ratio indicates that individuals with HIV have a 16.61 times higher risk of developing, vestibular involvement during their lifetime of living with the disease and that it may occur despite, being asymptomatic. Vestibular involvement was significantly more

  9. 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

  10. [Inferior vestibular neuritis: diagnosis using VEMP].

    PubMed

    Walther, L E; Repik, I

    2012-02-01

    Vestibular evoked myogenic potentials (VEMP) are a new method to establish the functional status of the otolith organs. The sacculocollic reflex of the cervical VEMP to air conduction (AC) reflects predominantly saccular function due to saccular afferents to the inferior vestibular nerve. We describe a case of inferior vestibular neuritis as a rare differential diagnosis of vestibular neuritis. Clinical signs were a normal caloric response, unilaterally absent AC cVEMPs and bilaterally preserved ocular VEMPs (AC oVEMPs).

  11. 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.

  12. Otolith-Canal Convergence in Vestibular Nuclei Neurons

    NASA Technical Reports Server (NTRS)

    Dickman, J. David

    1996-01-01

    During manned spaceflight, acute vestibular disturbances often occur, leading to physical duress and a loss of performance. Vestibular adaptation to the weightless environment follows within two to three days yet the mechanisms responsible for the disturbance and subsequent adaptation are still unknown In order to understand vestibular system function in space and normal earth conditions the basic physiological mechanisms of vestibular information co coding must be determined. Information processing regarding head movement and head position with respect to gravity takes place in the vestibular nuclei neurons that receive signals From the semicircular canals and otolith organs in the vestibular labyrinth. These neurons must synthesize the information into a coded output signal that provides for the head and eye movement reflexes as well as the conscious perception of the body in three-dimensional space The current investigation will for the first time. determine how the vestibular nuclei neurons quantitatively synthesize afferent information from the different linear and angular acceleration receptors in the vestibular labyrinths into an integrated output signal. During the second year of funding, progress on the current project has been focused on the anatomical orientation of semicircular canals and the spatial orientation of the innervating afferent responses. This information is necessary in order to understand how vestibular nuclei neurons process the incoming afferent spatial signals particularly with the convergent otolith afferent signals that are also spatially distributed Since information from the vestibular nuclei is presented to different brain regions associated with differing reflexive and sensory functions it is important to understand the computational mechanisms used by vestibular neurons to produce the appropriate output signal.

  13. Oculo-vestibular recoupling using galvanic vestibular stimulation to mitigate simulator sickness.

    PubMed

    Cevette, Michael J; Stepanek, Jan; Cocco, Daniela; Galea, Anna M; Pradhan, Gaurav N; Wagner, Linsey S; Oakley, Sarah R; Smith, Benn E; Zapala, David A; Brookler, Kenneth H

    2012-06-01

    Despite improvement in the computational capabilities of visual displays in flight simulators, intersensory visual-vestibular conflict remains the leading cause of simulator sickness (SS). By using galvanic vestibular stimulation (GVS), the vestibular system can be synchronized with a moving visual field in order to lessen the mismatch of sensory inputs thought to result in SS. A multisite electrode array was used to deliver combinations of GVS in 21 normal subjects. Optimal electrode combinations were identified and used to establish GVS dose-response predictions for the perception of roll, pitch, and yaw. Based on these data, an algorithm was then implemented in flight simulator hardware in order to synchronize visual and GVS-induced vestibular sensations (oculo-vestibular-recoupled or OVR simulation). Subjects were then randomly exposed to flight simulation either with or without OVR simulation. A self-report SS checklist was administered to all subjects after each session. An overall SS score was calculated for each category of symptoms for both groups. The analysis of GVS stimulation data yielded six unique combinations of electrode positions inducing motion perceptions in the three rotational axes. This provided the algorithm used for OVR simulation. The overall SS scores for gastrointestinal, central, and peripheral categories were 17%, 22.4%, and 20% for the Control group and 6.3%, 20%, and 8% for the OVR group, respectively. When virtual head signals produced by GVS are synchronized to the speed and direction of a moving visual field, manifestations of induced SS in a cockpit flight simulator are significantly reduced.

  14. 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.

  15. Task-dependent vestibular feedback responses in reaching.

    PubMed

    Keyser, Johannes; Medendorp, W Pieter; Selen, Luc P J

    2017-07-01

    When reaching for an earth-fixed object during self-rotation, the motor system should appropriately integrate vestibular signals and sensory predictions to compensate for the intervening motion and its induced inertial forces. While it is well established that this integration occurs rapidly, it is unknown whether vestibular feedback is specifically processed dependent on the behavioral goal. Here, we studied whether vestibular signals evoke fixed responses with the aim to preserve the hand trajectory in space or are processed more flexibly, correcting trajectories only in task-relevant spatial dimensions. We used galvanic vestibular stimulation to perturb reaching movements toward a narrow or a wide target. Results show that the same vestibular stimulation led to smaller trajectory corrections to the wide than the narrow target. We interpret this reduced compensation as a task-dependent modulation of vestibular feedback responses, tuned to minimally intervene with the task-irrelevant dimension of the reach. These task-dependent vestibular feedback corrections are in accordance with a central prediction of optimal feedback control theory and mirror the sophistication seen in feedback responses to mechanical and visual perturbations of the upper limb. NEW & NOTEWORTHY Correcting limb movements for external perturbations is a hallmark of flexible sensorimotor behavior. While visual and mechanical perturbations are corrected in a task-dependent manner, it is unclear whether a vestibular perturbation, naturally arising when the body moves, is selectively processed in reach control. We show, using galvanic vestibular stimulation, that reach corrections to vestibular perturbations are task dependent, consistent with a prediction of optimal feedback control theory. Copyright © 2017 the American Physiological Society.

  16. 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.

  17. 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

  18. 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

  19. Dyscalculia and vestibular function.

    PubMed

    Smith, P F

    2012-10-01

    A few studies in humans suggest that changes in stimulation of the balance organs of the inner ear (the 'vestibular system') can disrupt numerical cognition, resulting in 'dyscalculia', the inability to manipulate numbers. Many studies have also demonstrated that patients with vestibular dysfunction exhibit deficits in spatial memory. It is suggested that there may be a connection between spatial memory deficits resulting from vestibular dysfunction and the occurrence of dyscalculia, given the evidence that numerosity is coupled to the processing of spatial information (e.g., the 'spatial numerical association of response codes ('SNARC') effect'). The evidence supporting this hypothesis is summarised and potential experiments to test it are proposed. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Subclinical vestibular dysfunction in migraine patients: a preliminary study of ocular and rectified cervical vestibular evoked myogenic potentials.

    PubMed

    Kim, Chul-Ho; Jang, Min-Uk; Choi, Hui-Chul; Sohn, Jong-Hee

    2015-01-01

    Many studies have identified various vestibular symptoms and laboratory abnormalities in migraineurs. Although the vestibular tests may be abnormal, the changes may exist without vestibular symptoms. To date, vestibular-evoked myogenic potential (VEMP) has been the easiest and simplest test for measuring vestibular function in clinical practice. Cervical VEMP (cVEMP) represents a vestibulo-collic reflex, whereas ocular VEMP (oVEMP) reflects a vestibulo-ocular pathway. Therefore, we determined whether ocular and rectified cervical VEMPs differed in patients with migraine or tension type headache (TTH) and compared the results to controls with no accompanying vestibular symptoms. The present study included 38 females with migraine without aura, 30 with episodic TTH, and 50 healthy controls without vestibular symptoms. oVEMP and cVEMP using a blood pressure manometer were recorded during a headache-free period. From the VEMP graphs, latency and amplitude parameters were analyzed, especially following EMG rectification in cVEMP. With respect to oVEMP, the migraine group exhibited significantly longer mean latencies of bilateral n1 and left p1 than the other groups (p < 0.05). Amplitudes of n1-p1 were lower than in other groups, but the difference did not reach statistical significance. In regards to cVEMP, p13 and n23 latencies and amplitudes after rectification did not differ significantly among groups. An abnormal interictal oVEMP profile was associated with subclinical vestibular dysfunction in migraineurs, suggesting pathology within the vestibulo-ocular reflex. oVEMP is a more reliable measure than cVEMP to evaluate vestibular function in migraineurs, although results from the two tests in patients with migraine are complementary.

  1. Vestibular Deficits Following Youth Concussion

    PubMed Central

    Corwin, Daniel J.; Wiebe, Douglas J.; Zonfrillo, Mark R.; Grady, Matthew F.; Robinson, Roni L.; Goodman, Arlene M.; Master, Christina L.

    2015-01-01

    Objective To characterize the prevalence and recovery of pediatric patients with concussion who manifest clinical vestibular deficits, and to describe the correlation of these deficits with neurocognitive function, based on computerized neurocognitive testing, in a sample of pediatric patients with concussion. Methods This was a retrospective cohort study of patients age 5–18 years old with concussion referred to a tertiary pediatric hospital-affiliated sports medicine clinic from 7/1/2010–12/31/2011. A random sample of all eligible patient visits was obtained, and all related visits for those patients were reviewed. Results 247 patients were chosen from 3740 eligible visits for detailed review and abstraction. 81% showed a vestibular abnormality on initial clinical exam. Those patients with vestibular signs on initial exam took a significantly longer time to return to school (median 59 days vs. 6 days, p=0.001) or to be fully cleared (median 106 days vs. 29 days, p=0.001). They additionally scored more poorly on initial computerized neurocognitive testing, and took longer for neurocognitive deficits to recover. Those patients with three or more prior concussions had a higher prevalence of vestibular deficits and took longer for those deficits to resolve. Conclusion Vestibular deficits in children and adolescents with a history of concussion are highly prevalent. These deficits appear to be associated with extended recovery times and poorer performance on neurocognitive testing. Further studies evaluating the effectiveness of vestibular therapy on improving such deficits are warranted. PMID:25748568

  2. Vestibular morphology in the German Waltzing guinea pig.

    PubMed

    Kawaguchi, Sachie; Hultcrantz, Malou; Jin, Zhe; Ulfendahl, Mats; Suzuki, Mamoru

    2010-04-01

    The German waltzing guinea pig is a special strain of animal with a recessively inherited inner ear defect, resulting in deafness and a severe vestibular dysfunction. The hearing loss in the cochlea of the German strain is a result of a collapse of the Reissner membrane and the absence of scala media. The vestibular organ has not yet been described. German waltzing guinea pigs (homozygote and heterozygote) of different ages ranging from embryologic age 25 days to adulthood were investigated. The living animals were tested with four different vestibular tests, and the fetuses were controlled according to breeding. The morphology of the vestibular parts (ampulla, saccule, and utricle) was observed by using the light and transmission electron microscopy. Collapse of the membranous labyrinth was found already at embryologic age 50 days and progressed over time. Vestibular dysfunction was noted already from birth. Vestibular atelectasis has been shown to have the same morphology as the reported vestibular dysfunction in the German waltzing guinea pig. Owing to this similarity, this animal can be a good model for vestibular research.

  3. 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

  4. A novel v- silicone vestibular stent: preventing vestibular stenosis and preserving nasal valves.

    PubMed

    Bassam, Wameedh Al; Bhargava, Deepa; Al-Abri, Rashid

    2012-01-01

    This report presents a novel style of placing nasal stents. Patients undergoing surgical procedures in the region of nasal vestibule and nasal valves are at risk of developing vestibular stenosis and lifelong problems with the external and internal nasal valves; sequels of the repair. The objective of the report is to demonstrate a simple and successful method of an inverted V- Stent placement to prevent potential complication of vestibular stenosis and nasal valve compromise later in life. Following a fall on a sharp edge of a metallic bed, a sixteen month old child with a deep lacerated nasal wound extending from the collumellar base toward the tip of the nose underwent surgical exploration and repair of the nasal vestibule and nasal cavity. A soft silicone stent fashioned as inverted V was placed bilaterally. The child made a remarkable recovery with no evidence of vestibular stenosis or nasal valve abnormalities. In patients with nasal trauma involving the nasal vestibule and internal and external nasal valves stent placement avoids sequels, adhesions, contractures, synechia vestibular stenosis and fibrosis involving these anatomical structures. The advantages of the described V- stents over the traditional readymade ridged nasal stents, tubing's and composite aural grafts are: a) technical simplicity of use, b) safety, c) less morbidity, d) more comfortable, and e) economical. To our knowledge, this is the first report of such a stent for prevention of vestibular stenosis and preserving nasal valves.

  5. A Novel V- Silicone Vestibular Stent: Preventing Vestibular Stenosis and Preserving Nasal Valves

    PubMed Central

    Bassam, Wameedh AL; Bhargava, Deepa; Al-Abri, Rashid

    2012-01-01

    This report presents a novel style of placing nasal stents. Patients undergoing surgical procedures in the region of nasal vestibule and nasal valves are at risk of developing vestibular stenosis and lifelong problems with the external and internal nasal valves; sequels of the repair. The objective of the report is to demonstrate a simple and successful method of an inverted V- Stent placement to prevent potential complication of vestibular stenosis and nasal valve compromise later in life. Following a fall on a sharp edge of a metallic bed, a sixteen month old child with a deep lacerated nasal wound extending from the collumellar base toward the tip of the nose underwent surgical exploration and repair of the nasal vestibule and nasal cavity. A soft silicone stent fashioned as inverted V was placed bilaterally. The child made a remarkable recovery with no evidence of vestibular stenosis or nasal valve abnormalities. In patients with nasal trauma involving the nasal vestibule and internal and external nasal valves stent placement avoids sequels, adhesions, contractures, synechia vestibular stenosis and fibrosis involving these anatomical structures. The advantages of the described V- stents over the traditional readymade ridged nasal stents, tubing’s and composite aural grafts are: a) technical simplicity of use, b) safety, c) less morbidity, d) more comfortable, and e) economical. To our knowledge, this is the first report of such a stent for prevention of vestibular stenosis and preserving nasal valves. PMID:22359729

  6. Vestibular development in marsupials and monotremes

    PubMed Central

    Ashwell, Ken W S; Shulruf, Boaz

    2014-01-01

    The young of marsupials and monotremes are all born in an immature state, followed by prolonged nurturing by maternal lactation in either a pouch or nest. Nevertheless, the level of locomotor ability required for newborn marsupials and monotremes to reach the safety of the pouch or nest varies considerably: some are transferred to the pouch or nest in an egg (monotremes); others are transferred passively by gravity (e.g. dasyurid marsupials); some have only a horizontal wriggle to make (e.g. peramelid and didelphid marsupials); and others must climb vertically for a long distance to reach the maternal pouch (e.g. diprotodontid marsupials). In the present study, archived sections of the inner ear and hindbrain held in the Bolk, Hill and Hubrecht collections at the Museum für Naturkunde, Berlin, were used to test the relationship between structural maturity of the vestibular apparatus and the locomotor challenges that face the young of these different mammalian groups. A system for staging different levels of structural maturity of the vestibular apparatus was applied to the embryos, pouch young and hatchlings, and correlated with somatic size as indicated by greatest body length. Dasyurids are born at the most immature state, with the vestibular apparatus at little more than the otocyst stage. Peramelids are born with the vestibular apparatus at a more mature state (fully developed semicircular ducts and a ductus reuniens forming between the cochlear duct and saccule, but no semicircular canals). Diprotodontids and monotremes are born with the vestibular apparatus at the most mature state for the non-eutherians (semicircular canals formed, maculae present, but vestibular nuclei in the brainstem not yet differentiated). Monotremes and marsupials reach the later stages of vestibular apparatus development at mean body lengths that lie within the range of those found for laboratory rodents (mouse and rat) reaching the same vestibular stage. PMID:24298911

  7. Vertigo Perception and Quality of Life in Patients after Surgical Treatment of Vestibular Schwannoma with Pretreatment Prehabituation by Chemical Vestibular Ablation

    PubMed Central

    Balatková, Zuzana; Chovanec, Martin; Čakrt, Ondřej; Hrubá, Silvie; Jeřábek, Jaroslav; Zvěřina, Eduard; Profant, Oliver; Fík, Zdeněk; Komarc, Martin; Kluh, Jan; Černý, Rudolf

    2016-01-01

    Surgical removal of vestibular schwannoma causes acute vestibular symptoms, including postoperative vertigo and oscillopsia due to nystagmus. In general, the dominant symptom postoperatively is vertigo. Preoperative chemical vestibular ablation can reduce vestibular symptoms postoperatively. We used 1.0 mL of 40 mg/mL nonbuffered gentamicin in three intratympanic installations over 2 days, 2 months preoperatively in 10 patients. Reduction of vestibular function was measured by the head impulse test and the caloric test. Reduction of vestibular function was found in all gentamicin patient groups. After gentamicin vestibular ablation, patients underwent home vestibular exercising for two months. The control group consisted of 10 patients who underwent only home vestibular training two months preoperatively. Postoperative rates of recovery and vertigo in both groups were evaluated with the Glasgow Benefit Inventory (GBI), the Glasgow Health Status Inventory (GHSI), and the Dizziness Handicap Inventory questionnaires, as well as survey of visual symptoms by specific questionnaire developed by us. There were no statistically significant differences between both groups with regard to the results of questionnaires. Patients who received preoperative gentamicin were more resilient to optokinetic and optic flow stimulation (p < 0.05). This trial is registered with clinical study registration number NCT02963896. PMID:28053986

  8. Vertigo Perception and Quality of Life in Patients after Surgical Treatment of Vestibular Schwannoma with Pretreatment Prehabituation by Chemical Vestibular Ablation.

    PubMed

    Čada, Zdeněk; Balatková, Zuzana; Chovanec, Martin; Čakrt, Ondřej; Hrubá, Silvie; Jeřábek, Jaroslav; Zvěřina, Eduard; Profant, Oliver; Fík, Zdeněk; Komarc, Martin; Betka, Jan; Kluh, Jan; Černý, Rudolf

    2016-01-01

    Surgical removal of vestibular schwannoma causes acute vestibular symptoms, including postoperative vertigo and oscillopsia due to nystagmus. In general, the dominant symptom postoperatively is vertigo. Preoperative chemical vestibular ablation can reduce vestibular symptoms postoperatively. We used 1.0 mL of 40 mg/mL nonbuffered gentamicin in three intratympanic installations over 2 days, 2 months preoperatively in 10 patients. Reduction of vestibular function was measured by the head impulse test and the caloric test. Reduction of vestibular function was found in all gentamicin patient groups. After gentamicin vestibular ablation, patients underwent home vestibular exercising for two months. The control group consisted of 10 patients who underwent only home vestibular training two months preoperatively. Postoperative rates of recovery and vertigo in both groups were evaluated with the Glasgow Benefit Inventory (GBI), the Glasgow Health Status Inventory (GHSI), and the Dizziness Handicap Inventory questionnaires, as well as survey of visual symptoms by specific questionnaire developed by us. There were no statistically significant differences between both groups with regard to the results of questionnaires. Patients who received preoperative gentamicin were more resilient to optokinetic and optic flow stimulation ( p < 0.05). This trial is registered with clinical study registration number NCT02963896.

  9. Vestibular reflexes of otolith origin

    NASA Technical Reports Server (NTRS)

    Wilson, Victor J.

    1988-01-01

    The vestibular system and its role in the maintenance of posture and in motion sickness is investigated using cats as experimental subjects. The assumption is that better understanding of the physiology of vestibular pathways is not only of intrinsic value, but will help to explain and eventually alleviate the disturbances caused by vestibular malfunction, or by exposure to an unusual environment such as space. The first project deals with the influence on the spinal cord of stimulation of the vestibular labyrinth, particularly the otoliths. A second was concerned with the properties and neural basis of the tonic neck reflex. These two projects are related, because vestibulospinal and tonic neck reflexes interact in the maintenance of normal posture. The third project began with an interest in mechanisms of motion sickness, and eventually shifted to a study of central control of respiratory muscles involved in vomiting.

  10. Quality of life of individuals submitted to vestibular rehabilitation.

    PubMed

    Patatas, Olívia Helena Gomes; Ganança, Cristina Freitas; Ganança, Fernando Freitas

    2009-01-01

    Balance disorders affect social, family and professional activities. Vestibular rehabilitation can reduce the impact of these disorders on the quality of life of individuals with vertigo. to study the influence of vestibular rehabilitation on the quality of life of individuals, correlating it with gender, age, results from computerized vectoelectronystagmography and vertigo. Retrospective. Twenty-two individuals were submitted to customized vestibular rehabilitation and the Brazilian Dizziness Handicap Inventory - DHI before and after vestibular rehabilitation. Results from this questionnaire were correlated with gender, age, vestibular assessment and the presence of vertigo. all the DHI scores reduced significantly after vestibular rehabilitation. There were no differences among genders; adults and elderly patients; irritative peripheral vestibular syndromes; deficiency syndromes and normal exams; the presence or absence of vertigo. all the individuals had improvements in their quality of life after customized vestibular rehabilitation.

  11. Combined ocular and cervical vestibular evoked myogenic potential in individuals with vestibular hyporeflexia and in patients with Ménière's disease.

    PubMed

    Silva, Tatiana Rocha; de Resende, Luciana Macedo; Santos, Marco Aurélio Rocha

    The vestibular evoked myogenic potential is a potential of mean latency that measures the muscle response to auditory stimulation. This potential can be generated from the contraction of the sternocleidomastoid muscle and also from the contraction of extraocular muscles in response to high-intensity sounds. This study presents a combined or simultaneous technique of cervical and ocular vestibular evoked myogenic potential in individuals with changes in the vestibular system, for use in otoneurologic diagnosis. To characterize the records and analyze the results of combined cervical and ocular VEMP in individuals with vestibular hyporeflexia and in those with Ménière's disease. The study included 120 subjects: 30 subjects with vestibular hyporeflexia, 30 with Ménière's disease, and 60 individuals with normal hearing. Data collection was performed by simultaneously recording the cervical and ocular vestibular evoked myogenic potential. There were differences between the study groups (individuals with vestibular hyporeflexia and individuals with Ménière's disease) and the control group for most of wave parameters in combined cervical and ocular vestibular evoked myogenic potential. For cervical vestibular evoked myogenic potential, it was observed that the prolongation of latency of the P13 and N23 waves was the most frequent finding in the group with vestibular hyporeflexia and in the group with Ménière's disease. For ocular vestibular evoked myogenic potential, prolonged latency of N10 and P15 waves was the most frequent finding in the study groups. Combined cervical and ocular vestibular evoked myogenic potential presented relevant results for individuals with vestibular hyporeflexia and for those with Ménière's disease. There were differences between the study groups and the control group for most of the wave parameters in combined cervical and ocular vestibular evoked myogenic potential. Copyright © 2016 Associação Brasileira de Otorrinolaringologia

  12. The clinical manifestations of vestibular migraine: A review.

    PubMed

    O'Connell Ferster, Ashley P; Priesol, Adrian J; Isildak, Huseyin

    2017-06-01

    To provide an overview of vestibular migraines presentation, pathology, and diagnosis, as well as an update on current diagnostic criteria. A review of the most recent literature on vestibular migraines was performed. Vestibular migraine is a process with significant impact on the quality of life for those afflicted with the disease, with attacks of spontaneous or positional vertigo and migraine symptoms lasting several minutes to 72h. Inner ear disease can co-exist with migraine and the vestibular symptoms occurring with vestibular migraine can mimic inner ear disorders providing a challenge for clinicians in establishing diagnosis. Recent diagnostic criteria for vestibular migraine proposed by a joint committee of the Bárány Society and the International Headache Society provide an important standard for clinical diagnosis and research endeavor. Vestibular migraine is a challenging disease process to both diagnose and treat. Proper diagnosis and treatment requires a thorough understanding of the current literature. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Vestibular vertigo is associated with abnormal sleep duration.

    PubMed

    Albathi, Monirah; Agrawal, Yuri

    2017-01-01

    Several small studies in animals and humans have suggested a relationship between vestibular function and sleep. In this study, we evaluate the association between vestibular vertigo and sleep duration in a large, representative sample of US adults. We used data from the National Health Interview Survey, which administered a Balance Supplement in 2008 in a sample of 20,950 adult respondents. We evaluated the cross-sectional association between vestibular vertigo (based on a well-validated definition) and sleep duration (defined as short <6 hours, normal 6-8 hours, and long >8 hours). We performed multiple and multinomial logistic regression analyses to estimate the odds ratio and relative risk ratio (RRR) of impaired sleep duration compared to normal sleep duration associated with vestibular vertigo. Analyses were adjusted for demographic, lifestyle and health behavior characteristics as well as relevant comorbid conditions. Thirty percent of individuals with vestibular vertigo reported abnormal sleep duration (15.5% short duration and 14.8% long duration). In adjusted analyses, individuals with vestibular vertigo had a 1.75 (95% CI 1.45-2.11) RRR of having short sleep duration compared to individuals without vestibular vertigo, and a 1.55 (95% CI 1.26-1.91) RRR of having long sleep duration compared to individuals without vestibular vertigo. This study presents epidemiologic evidence to support the association between vestibular function and sleep duration. Individuals with vestibular vertigo had a higher RRR for abnormally short or long sleep duration. Further work is needed to evaluate the causal direction(s) of this association.

  14. 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

  15. Vestibular ontogeny: Measuring the influence of the dynamic environment

    NASA Technical Reports Server (NTRS)

    Jones, Timothy A.; Devries, Sherri M.; Dubois, Linda M.; Nelson, Rick C.

    1993-01-01

    In comparison to other special senses, we are only meagerly informed about the development of vestibular function and the mechanisms that may operate to control or influence the course of vestibular ontogeny. Perhaps one contributing factor to this disparity is the difficulty of evaluating vestibular sense organs directly and noninvasively. The present report describes a recently developed direct noninvasive vestibular function test that can be used to address many basic questions about the developing vestibular system. More particularly, the test can be used to examine the effects of the dynamic environment (e.g. gravitational field and vibration) on vestibular ontogeny.

  16. Preliminary evidence of improved cognitive performance following vestibular rehabilitation in children with combined ADHD (cADHD) and concurrent vestibular impairment.

    PubMed

    Lotfi, Younes; Rezazadeh, Nima; Moossavi, Abdollah; Haghgoo, Hojjat Allah; Rostami, Reza; Bakhshi, Enayatollah; Badfar, Faride; Moghadam, Sedigheh Farokhi; Sadeghi-Firoozabadi, Vahid; Khodabandelou, Yousef

    2017-12-01

    Balance function has been reported to be worse in ADHD children than in their normal peers. The present study hypothesized that an improvement in balance could result in better cognitive performance in children with ADHD and concurrent vestibular impairment. This study was designed to evaluate the effects of comprehensive vestibular rehabilitation therapy on the cognitive performance of children with combined ADHD and concurrent vestibular impairment. Subject were 54 children with combined ADHD. Those with severe vestibular impairment (n=33) were randomly assigned to two groups that were matched for age. A rehabilitation program comprising overall balance and gate, postural stability, and eye movement exercises was assigned to the intervention group. Subjects in the control group received no intervention for the same time period. Intervention was administered twice weekly for 12 weeks. Choice reaction time (CRT) and spatial working memory (SWM) subtypes of the Cambridge Neuropsychological Test Automated Battery (CANTAB) were completed pre- and post-intervention to determine the effects of vestibular rehabilitation on the cognitive performance of the subjects with ADHD and concurrent vestibular impairment. ANCOVA was used to compare the test results of the intervention and control group post-test. The percentage of correct trial scores for the CRT achieved by the intervention group post-test increased significantly compared to those of the control group (p=0.029). The CRT mean latency scores were significantly prolonged in the intervention group following intervention (p=0.007) compared to the control group. No significant change was found in spatial functioning of the subjects with ADHD following 12 weeks of intervention (p>0.05). The study highlights the effect of vestibular rehabilitation on the cognitive performance of children with combined ADHD and concurrent vestibular disorder. The findings indicate that attention can be affected by early vestibular

  17. Visual and vestibular components of motion sickness.

    PubMed

    Eyeson-Annan, M; Peterken, C; Brown, B; Atchison, D

    1996-10-01

    The relative importance of visual and vestibular information in the etiology of motion sickness (MS) is not well understood, but these factors can be manipulated by inducing Coriolis and pseudo-Coriolis effects in experimental subjects. We hypothesized that visual and vestibular information are equivalent in producing MS. The experiments reported here aim, in part, to examine the relative influence of Coriolis and pseudo-Coriolis effects in inducing MS. We induced MS symptoms by combinations of whole body rotation and tilt, and environment rotation and tilt, in 22 volunteer subjects. Subjects participated in all of the experiments with at least 2 d between each experiment to dissipate after-effects. We recorded MS signs and symptoms when only visual stimulation was applied, when only vestibular stimulation was applied, and when both visual and vestibular stimulation were applied under specific conditions of whole body and environmental tilt. Visual stimuli produced more symptoms of MS than vestibular stimuli when only visual or vestibular stimuli were used (ANOVA F = 7.94, df = 1, 21 p = 0.01), but there was no significant difference in MS production when combined visual and vestibular stimulation were used to produce the Coriolis effect or pseudo-Coriolis effect (ANOVA: F = 0.40, df = 1, 21 p = 0.53). This was further confirmed by examination of the order in which the symptoms occurred and the lack of a correlation between previous experience and visually induced MS. Visual information is more important than vestibular input in causing MS when these stimuli are presented in isolation. In conditions where both visual and vestibular information are present, cross-coupling appears to occur between the pseudo-Coriolis effect and the Coriolis effect, as these two conditions are not significantly different in producing MS symptoms.

  18. The Effect of Vestibular Rehabilitation Therapy Program on Sensory Organization of Deaf Children With Bilateral Vestibular Dysfunction.

    PubMed

    Ebrahimi, Amir Abbas; Jamshidi, Ali Ashraf; Movallali, Guita; Rahgozar, Mehdi; Haghgoo, Hojjat Allah

    2017-11-01

    The purpose of this study was to determine the effect of vestibular rehabilitation therapy program on the sensory organization of deaf children with bilateral vestibular dysfunction. This cross-sectional and analytic study was conducted on 24 students between the age of 7 and 12 years (6 girls and 18 boys) with the profound sensorineural hearing loss (PTA>90 dB). They were assessed through the balance subtest in Bruininks-Oseretsky test of motor proficiency (BOTMP). For children which the total score of the balance subtest was 3 standard deviation lower than their peers with typical development, vestibular function testing was completed pre-intervention. Posturography Sensory organization testing (SOT) was completed pre- and post-intervention with SPS (Synapsys, Marseille, France). Children with bilateral vestibular impairment were randomly assigned to either the exercise or control group. Exercise intervention consisted of compensatory training, emphasizing enhancement of visual and somatosensory function, and balance training. The exercise group entered in vestibular rehabilitation therapy program for 8 weeks. The children initially participating in the control group were provided the exercise intervention following the post-test. Based on the results there was significant difference in condition 5 and 6, areas of limits of stability (LOS), vestibular ratio and global score in posturography at the end of the intervention, but there was no significant difference in the control group in posturography (P<0.05). The results indicated that testing of vestibular, and postural control function, as well as intervention for deficiencies identified, should be included in deaf children rehabilitation program.

  19. 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.

  20. Auditory and Vestibular Issues Related to Human Spaceflight

    NASA Technical Reports Server (NTRS)

    Danielson, Richard W.; Wood, Scott J.

    2009-01-01

    Human spaceflight provides unique opportunities to study human vestibular and auditory systems. This session will discuss 1) vestibular adaptive processes reflected by pronounced perceptual and motor coordination problems during, and after, space missions; 2) vestibular diagnostic and rehabilitative techniques (used to promote recovery after living in altered gravity environments) that may be relevant to treatment of vestibular disorders on earth; and 3) unique acoustical challenges to hearing loss prevention and crew performance during spaceflight missions.

  1. Multisensory effects on somatosensation: a trimodal visuo-vestibular-tactile interaction

    PubMed Central

    Kaliuzhna, Mariia; Ferrè, Elisa Raffaella; Herbelin, Bruno; Blanke, Olaf; Haggard, Patrick

    2016-01-01

    Vestibular information about self-motion is combined with other sensory signals. Previous research described both visuo-vestibular and vestibular-tactile bilateral interactions, but the simultaneous interaction between all three sensory modalities has not been explored. Here we exploit a previously reported visuo-vestibular integration to investigate multisensory effects on tactile sensitivity in humans. Tactile sensitivity was measured during passive whole body rotations alone or in conjunction with optic flow, creating either purely vestibular or visuo-vestibular sensations of self-motion. Our results demonstrate that tactile sensitivity is modulated by perceived self-motion, as provided by a combined visuo-vestibular percept, and not by the visual and vestibular cues independently. We propose a hierarchical multisensory interaction that underpins somatosensory modulation: visual and vestibular cues are first combined to produce a multisensory self-motion percept. Somatosensory processing is then enhanced according to the degree of perceived self-motion. PMID:27198907

  2. Passive motion reduces vestibular balance and perceptual responses

    PubMed Central

    Fitzpatrick, Richard C; Watson, Shaun R D

    2015-01-01

    With the hypothesis that vestibular sensitivity is regulated to deal with a range of environmental motion conditions, we explored the effects of passive whole-body motion on vestibular perceptual and balance responses. In 10 subjects, vestibular responses were measured before and after a period of imposed passive motion. Vestibulospinal balance reflexes during standing evoked by galvanic vestibular stimulation (GVS) were measured as shear reaction forces. Perceptual tests measured thresholds for detecting angular motion, perceptions of suprathreshold rotation and perceptions of GVS-evoked illusory rotation. The imposed conditioning motion was 10 min of stochastic yaw rotation (0.5–2.5 Hz ≤ 300 deg s−2) with subjects seated. This conditioning markedly reduced reflexive and perceptual responses. The medium latency galvanic reflex (300–350 ms) was halved in amplitude (48%; P = 0.011) but the short latency response was unaffected. Thresholds for detecting imposed rotation more than doubled (248%; P < 0.001) and remained elevated after 30 min. Over-estimation of whole-body rotation (30–180 deg every 5 s) before conditioning was significantly reduced (41.1 to 21.5%; P = 0.033). Conditioning reduced illusory vestibular sensations of rotation evoked by GVS (mean 113 deg for 10 s at 1 mA) by 44% (P < 0.01) and the effect persisted for at least 1 h (24% reduction; P < 0.05). We conclude that a system of vestibular sensory autoregulation exists and that this probably involves central and peripheral mechanisms, possibly through vestibular efferent regulation. We propose that failure of these regulatory mechanisms at different levels could lead to disorders of movement perception and balance control during standing. Key points Human activity exposes the vestibular organs to a wide dynamic range of motion. We aimed to discover whether the CNS regulates sensitivity to vestibular afference during exposure to ambient motion. Balance and perceptual

  3. 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

  4. Internal Models, Vestibular Cognition, and Mental Imagery: Conceptual Considerations.

    PubMed

    Mast, Fred W; Ellis, Andrew W

    2015-01-01

    Vestibular cognition has recently gained attention. Despite numerous experimental and clinical demonstrations, it is not yet clear what vestibular cognition really is. For future research in vestibular cognition, adopting a computational approach will make it easier to explore the underlying mechanisms. Indeed, most modeling approaches in vestibular science include a top-down or a priori component. We review recent Bayesian optimal observer models, and discuss in detail the conceptual value of prior assumptions, likelihood and posterior estimates for research in vestibular cognition. We then consider forward models in vestibular processing, which are required in order to distinguish between sensory input that is induced by active self-motion, and sensory input that is due to passive self-motion. We suggest that forward models are used not only in the service of estimating sensory states but they can also be drawn upon in an offline mode (e.g., spatial perspective transformations), in which interaction with sensory input is not desired. A computational approach to vestibular cognition will help to discover connections across studies, and it will provide a more coherent framework for investigating vestibular cognition.

  5. Outcome analysis of individualized vestibular rehabilitation protocols

    NASA Technical Reports Server (NTRS)

    Black, F. O.; Angel, C. R.; Pesznecker, S. C.; Gianna, C.

    2000-01-01

    OBJECTIVE: To determine the outcome of vestibular rehabilitation protocols in subjects with peripheral vestibular disorders compared with normal and abnormal control subjects. STUDY DESIGN: Prospective study using repeated measure, matched control design. Subjects were solicited consecutively according to these criteria: vestibular disorder subjects who had abnormal results of computerized dynamic posturography (CDP) sensory organization tests (SOTs) 5 and 6 and underwent rehabilitation; vestibular disorder subjects who had abnormal results of SOTs 5 and 6 and did not undergo rehabilitation; and normal subjects (normal SOTs). SETTING: Tertiary neurotology clinic. SUBJECTS: Men and women over age 18 with chronic vestibular disorders and chief complaints of unsteadiness, imbalance, and/or motion intolerance, and normal subjects. INTERVENTIONS: Pre- and post-rehabilitation assessment included CDP, vestibular disability, and activities of daily living questionnaires. Individualized rehabilitation plans were designed and implemented to address the subject's specific complaints and functional deficits. Supervised sessions were held at weekly intervals, and self-administered programs were devised for daily home use. MAIN OUTCOME MEASURES: CDP composite and SOT scores, number of falls on CDP, and self-assessment questionnaire results. RESULTS: Subjects who underwent rehabilitation (Group A) showed statistically significant improvements in SOTs, overall composite score, and reduction in falls compared with abnormal (Group B) control groups. Group A's performances after rehabilitation were not significantly different from those of normal subjects (Group C) in SOTs 3 through 6, and close to normal on SOTs 1 and 2. Subjects in Group A also reported statistically significant symptomatic improvement. CONCLUSIONS: Outcome measures of vestibular protocol physical therapy confirmed objective and subjective improvement in subjects with chronic peripheral vestibular disorders. These

  6. Vestibular-induced vomiting after vestibulocerebellar lesions

    NASA Technical Reports Server (NTRS)

    Miller, A. D.; Wilson, V. J.

    1983-01-01

    Vestibular stimulation, by sinusoidal electrical polarization of the labyrinths of decerebrate cats which can produce vomiting and related activity which resembles motion sickness was examined. The symptoms include panting, salivation, swallowing, and retching as well as vomiting. These symptoms can be produced in cats with lesions of the posterior cerebellar vermis. It is suggested that a transcerebellar pathway from the vestibular apparatus through the nodulus and uvula to the vomiting center is not essential for vestibular induced vomiting and the occurrence of many symptoms of motion.

  7. Vestibular-induced vomiting after vestibulocerebellar lesions

    NASA Technical Reports Server (NTRS)

    Miller, A. D.; Wilson, V. J.

    1982-01-01

    Vestibular stimulation, by sinusoidal electrical polarization of the labyrinths of decerebrate cats which can produce vomiting and related activity which resembles motion sickness was examined. The symptoms include panting, salivation, swallowing, and retching as well as vomiting. These symptoms can be produced in cats with lesions of the posterior cerebellar vermis. It is suggested that a transcerebellar pathway from the vestibular apparatus through the nodulus and uvula to the vomiting center is not essential for vestibular induced vomiting and the occurrence of many symptoms of motion.

  8. Vestibular receptors contribute to cortical auditory evoked potentials.

    PubMed

    Todd, Neil P M; Paillard, Aurore C; Kluk, Karolina; Whittle, Elizabeth; Colebatch, James G

    2014-03-01

    Acoustic sensitivity of the vestibular apparatus is well-established, but the contribution of vestibular receptors to the late auditory evoked potentials of cortical origin is unknown. Evoked potentials from 500 Hz tone pips were recorded using 70 channel EEG at several intensities below and above the vestibular acoustic threshold, as determined by vestibular evoked myogenic potentials (VEMPs). In healthy subjects both auditory mid- and long-latency auditory evoked potentials (AEPs), consisting of Na, Pa, N1 and P2 waves, were observed in the sub-threshold conditions. However, in passing through the vestibular threshold, systematic changes were observed in the morphology of the potentials and in the intensity dependence of their amplitude and latency. These changes were absent in a patient without functioning vestibular receptors. In particular, for the healthy subjects there was a fronto-central negativity, which appeared at about 42 ms, referred to as an N42, prior to the AEP N1. Source analysis of both the N42 and N1 indicated involvement of cingulate cortex, as well as bilateral superior temporal cortex. Our findings are best explained by vestibular receptors contributing to what were hitherto considered as purely auditory evoked potentials and in addition tentatively identify a new component that appears to be primarily of vestibular origin. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  9. 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

  10. Vestibular function in families with inherited autosomal dominant hearing loss

    PubMed Central

    Street, Valerie A.; Kallman, Jeremy C.; Strombom, Paul D.; Bramhall, Naomi F.; Phillips, James O.

    2008-01-01

    The inner ear contains the developmentally related cochlea and peripheral vestibular labyrinth. Given the similar physiology between these two organs, hearing loss and vestibular dysfunction may be expected to occur simultaneously in individuals segregating mutations in inner ear genes. Twenty-two different genes have been discovered that when mutated lead to non-syndromic autosomal dominant hearing loss. A review of the literature indicates that families segregating mutations in 13 of these 22 genes have undergone formal clinical vestibular testing. Formal assessment revealed vestibular dysfunction in families with mutations in ten of these 13 genes. Remarkably, only families with mutations in the COCH and MYO7A genes self-report considerable vestibular challenges. Families segregating mutations in the other eight genes do not self-report significant balance problems and appear to compensate well in everyday life for vestibular deficits discovered during formal clinical vestibular assessment. An example of a family (referred to as the HL1 family) with progressive hearing loss and clinically-detected vestibular hypofunction that does not report vestibular symptoms is described in this review. Notably, one member of the HL1 family with clinically-detected vestibular hypofunction reached the summit of Mount Kilimanjaro. PMID:18776598

  11. Choline acetyltransferase immunoreactivity in the human vestibular end-organs.

    PubMed

    Ishiyama, A; Lopez, I; Wackym, P A

    1994-10-01

    Acetylcholine (ACh) is believed to play a major role in the efferent vestibular system in several animal models, however no information regarding the role of ACh in the human efferent vestibular system has been published. Post-embedding immunohistochemistry in a hydrophilic resin was used to investigate the choline acetyltransferase immunoreactivity (ChATi) and acetylcholinesterase (AChE) histochemistry in human vestibular end-organs. ChATi and AChE activity was found in numerous bouton-type terminals at the basal area of the vestibular hair cells. These terminals were found to contact type II vestibular hair cells and the afferent chalices surrounding type I hair cells. This study provides the first evidence that the human efferent vestibular axons and terminals are cholinergic.

  12. 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

  13. 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.

  14. 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.

  15. Neurotology symptoms at referral to vestibular evaluation

    PubMed Central

    2013-01-01

    Background Dizziness-vertigo is common in adults, but clinical providers may rarely diagnose vestibular impairment and referral could be delayed. To assess neurotology symptoms (including triggers) reported by patients with peripheral vestibular disease, during the year just before their referral to vestibular evaluation. Methods 282 patients with peripheral vestibular disease and 282 control subjects accepted to participate. They had no middle ear, retinal, neurological, psychiatric, autoimmune or autonomic disorders. They reported their symptoms by a standardized questionnaire along with their anxiety/depression symptoms. Results Patients were referred after months or years from the onset of their symptoms, 24% of them reported frequent falls with a long clinical evolution; 10% of them reported no vertigo but instability related to specific triggers; 86% patients and 12% control subjects reported instability when moving the head rapidly and 79% patients and 6% control subjects reported instability when changing posture. Seven out of the 9 symptoms explored by the questionnaire allowed the correct classification of circa 95% of the participants (Discriminant function analysis, p < 0.001). High blood pressure, dyslipidemia and anxiety/depression symptoms showed a mild correlation with the total score of symptoms (multiple R2 =0.18, p < 0.001). Conclusions Late referral to vestibular evaluation may underlie a history of frequent falls; some patients may not report vertigo, but instability related to specific triggers, which could be useful to prompt vestibular evaluation. High blood pressure, dyslipidemia and anxiety/depression symptoms may have a mild influence on the report of symptoms of vestibular disease in both, patients and control subjects. PMID:24279682

  16. Chronic inflammatory demyelinating polyneuropathy: evaluation of the vestibular system with cervical and ocular vestibular evoked myogenic potentials.

    PubMed

    Magliulo, Giuseppe; Iannella, Giannicola; Manno, Alessandra; Libonati, Laura; Onesti, Emanuela; Vestri, Annarita; Fegatelli, Danilo Alunni; Angeletti, Diletta; Pace, Annalisa; Gulotta, Giampiero; Gagliardi, Silvia; Inghilleri, Maurizio

    2018-06-01

    To investigate the possibility of vestibular damage in a group of patients suffering from chronic inflammatory demyelinating polyneuropathy (CIDP) using a diagnostic protocol including the caloric test, C-VEMPs and O-VEMPs. Twenty patients suffering from CIDP (mean age 58.5 years, range 33-80 years; 4 women and 16 men) were investigated. To assess any eventual audio-vestibular involvement, all patients of the study underwent pure tone audiometry, Fitzgerald-Hallpike caloric vestibular test, C-VEMPs and O-VEMPs. In 11 patients with CIDP values of both O-VEMPs and C-VEMPs were either absent or abnormal. An absent trace at O-VEMPs testing occurred in 36% of these pathological patients, whereas an increase of n10 latency and amplitude was present in the other 64% . A specific diagnostic protocol including the caloric test, C-VEMPS, O-VEMPS, could be useful when employed for identifying vestibular damage in CIDP patients.

  17. 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.

  18. 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

  19. Vestibular-visual interactions in flight simulators

    NASA Technical Reports Server (NTRS)

    Clark, B.

    1977-01-01

    The following research work is reported: (1) vestibular-visual interactions; (2) flight management and crew system interactions; (3) peripheral cue utilization in simulation technology; (4) control of signs and symptoms of motion sickness; (5) auditory cue utilization in flight simulators, and (6) vestibular function: Animal experiments.

  20. Optokinetic and Vestibular Responsiveness in the Macaque Rostral Vestibular and Fastigial Nuclei

    PubMed Central

    Bryan, Ayanna S.; Angelaki, Dora E.

    2009-01-01

    We recorded from rostral vestibular (VN) and rostral fastigial nuclei (FN) neurons that did not respond to eye movements during three-dimensional (3D) vestibular and optokinetic stimulation (OKS). The majority of neurons in both areas (76 and 69% in VN and FN, respectively) responded during both rotational and translational motion. Preferred directions scattered throughout 3D space for translation but showed some preference for pitch/roll over yaw for rotation. VN/FN neurons were also tested during OKS while monkeys suppressed their optokinetic nystagmus by fixating a head-fixed target. Only a handful of cells (VN: 17%, FN: 6%) modulated during 0.5-Hz OKS suppression, but the number of responsive cells increased (VN: 40%, FN: 48%) during 0.02-Hz OKS. Preferred directions for rotation and OKS were not matched on individual neurons, and OKS gains were smaller than the respective gains during rotation. These results were generally similar for VN and FN neurons. We conclude that optokinetic-vestibular convergence might not be as prevalent as earlier studies have suggested. PMID:19073813

  1. Increased independence and decreased vertigo after vestibular rehabilitation.

    PubMed

    Cohen, Helen S; Kimball, Kay T

    2003-01-01

    We sought to determine the effectiveness in decreasing some symptoms, such as vertigo, and increasing performance of daily life skills after vestibular rehabilitation. Patients who had chronic vertigo due to peripheral vestibular impairments were seen at a tertiary care center. They were referred for vestibular rehabilitation and were assessed on vertigo intensity and frequency with the use of the Vertigo Symptom Scale, the Vertigo Handicap Questionnaire, the Vestibular Disorders Activities of Daily Living Scale, and the Dizziness Handicap Inventory. They were then randomly assigned to 1 of 3 home program treatment groups. Vertigo decreased and independence in activities of daily living improved significantly. Improvement was not affected by age, gender, or history of vertigo. For many patients a simple home program of vestibular habituation head movement exercises is related to reduction in symptoms and increasing independence in activities of daily living.

  2. Vestibular system: the many facets of a multimodal sense.

    PubMed

    Angelaki, Dora E; Cullen, Kathleen E

    2008-01-01

    Elegant sensory structures in the inner ear have evolved to measure head motion. These vestibular receptors consist of highly conserved semicircular canals and otolith organs. Unlike other senses, vestibular information in the central nervous system becomes immediately multisensory and multimodal. There is no overt, readily recognizable conscious sensation from these organs, yet vestibular signals contribute to a surprising range of brain functions, from the most automatic reflexes to spatial perception and motor coordination. Critical to these diverse, multimodal functions are multiple computationally intriguing levels of processing. For example, the need for multisensory integration necessitates vestibular representations in multiple reference frames. Proprioceptive-vestibular interactions, coupled with corollary discharge of a motor plan, allow the brain to distinguish actively generated from passive head movements. Finally, nonlinear interactions between otolith and canal signals allow the vestibular system to function as an inertial sensor and contribute critically to both navigation and spatial orientation.

  3. 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.

  4. Association between vestibular function and motor performance in hearing-impaired children.

    PubMed

    Maes, Leen; De Kegel, Alexandra; Van Waelvelde, Hilde; Dhooge, Ingeborg

    2014-12-01

    The clinical balance performance of normal-hearing (NH) children was compared with the balance performance of hearing-impaired (HI) children with and without vestibular dysfunction to identify an association between vestibular function and motor performance. Prospective study. Tertiary referral center. Thirty-six children (mean age, 7 yr 5 mo; range, 3 yr 8 mo-12 yr 11 mo) divided into three groups: NH children with normal vestibular responses, HI children with normal vestibular responses, and HI children with abnormal vestibular function. A vestibular test protocol (rotatory and collic vestibular evoked myogenic potential testing) in combination with three clinical balance tests (balance beam walking, one-leg hopping, one-leg stance). Clinical balance performance. HI children with abnormal vestibular test results obtained the lowest quotients of motor performance, which were significantly lower compared with the NH group (p < 0.001 for balance beam walking and one-leg stance; p = 0.003 for one-leg hopping). The balance performance of the HI group with normal vestibular responses was better in comparison with the vestibular impaired group but still significantly lower compared with the NH group (p = 0.020 for balance beam walking; p = 0.001 for one-leg stance; not significant for one-leg hopping). These results indicate an association between vestibular function and motor performance in HI children, with a more distinct motor deterioration if a vestibular impairment is superimposed to the auditory dysfunction.

  5. Clinical application of vestibular evoked myogenic potential (VEMP).

    PubMed

    Murofushi, Toshihisa

    2016-08-01

    The author reviewed clinical aspects of vestibular evoked myogenic potentials (VEMPs). Now two types of VEMPs are available. The first one is cervical VEMP, which is recorded in the sternocleidomastoid muscle and predominantly reflects sacculo-collic reflex. The other is ocular VEMP, which is usually recorded below the lower eye lid and predominantly reflects utriculo-ocular reflex. VEMPs play important roles not only for assessment of common vestibular diseases but also for establishment of new clinical entities. Clinical application in Meniere's disease, vestibular neuritis, benign paroxysmal positional vertigo, vestibular migraine, idiopathic otolithic vertigo, and central vertigo/dizziness was reviewed. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  6. 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.

  7. Physiological principles of vestibular function on earth and in space

    NASA Technical Reports Server (NTRS)

    Minor, L. B.

    1998-01-01

    Physiological mechanisms underlying vestibular function have important implications for our ability to understand, predict, and modify balance processes during and after spaceflight. The microgravity environment of space provides many unique opportunities for studying the effects of changes in gravitoinertial force on structure and function of the vestibular system. Investigations of basic vestibular physiology and of changes in reflexes occurring as a consequence of exposure to microgravity have important implications for diagnosis and treatment of vestibular disorders in human beings. This report reviews physiological principles underlying control of vestibular processes on earth and in space. Information is presented from a functional perspective with emphasis on signals arising from labyrinthine receptors. Changes induced by microgravity in linear acceleration detected by the vestibulo-ocular reflexes. Alterations of the functional requirements for postural control in space are described. Areas of direct correlation between studies of vestibular reflexes in microgravity and vestibular disorders in human beings are discussed.

  8. Adaptive plasticity in vestibular influences on cardiovascular control

    NASA Technical Reports Server (NTRS)

    Yates, B. J.; Holmes, M. J.; Jian, B. J.

    2000-01-01

    Data collected in both human subjects and animal models indicate that the vestibular system influences the control of blood pressure. In animals, peripheral vestibular lesions diminish the capacity to rapidly and accurately make cardiovascular adjustments to changes in posture. Thus, one role of vestibulo-cardiovascular influences is to elicit changes in blood distribution in the body so that stable blood pressure is maintained during movement. However, deficits in correcting blood pressure following vestibular lesions diminish over time, and are less severe when non-labyrinthine sensory cues regarding body position in space are provided. These observations show that pathways that mediate vestibulo-sympathetic reflexes can be subject to plastic changes. This review considers the adaptive plasticity in cardiovascular responses elicited by the central vestibular system. Recent data indicate that the posterior cerebellar vermis may play an important role in adaptation of these responses, such that ablation of the posterior vermis impairs recovery of orthostatic tolerance following subsequent vestibular lesions. Furthermore, recent experiments suggest that non-labyrinthine inputs to the central vestibular system may be important in controlling blood pressure during movement, particularly following vestibular dysfunction. A number of sensory inputs appear to be integrated to produce cardiovascular adjustments during changes in posture. Although loss of any one of these inputs does not induce lability in blood pressure, it is likely that maximal blood pressure stability is achieved by the integration of a variety of sensory cues signaling body position in space.

  9. The vestibular system: a spatial reference for bodily self-consciousness

    PubMed Central

    Pfeiffer, Christian; Serino, Andrea; Blanke, Olaf

    2014-01-01

    Self-consciousness is the remarkable human experience of being a subject: the “I”. Self-consciousness is typically bound to a body, and particularly to the spatial dimensions of the body, as well as to its location and displacement in the gravitational field. Because the vestibular system encodes head position and movement in three-dimensional space, vestibular cortical processing likely contributes to spatial aspects of bodily self-consciousness. We review here recent data showing vestibular effects on first-person perspective (the feeling from where “I” experience the world) and self-location (the feeling where “I” am located in space). We compare these findings to data showing vestibular effects on mental spatial transformation, self-motion perception, and body representation showing vestibular contributions to various spatial representations of the body with respect to the external world. Finally, we discuss the role for four posterior brain regions that process vestibular and other multisensory signals to encode spatial aspects of bodily self-consciousness: temporoparietal junction, parietoinsular vestibular cortex, ventral intraparietal region, and medial superior temporal region. We propose that vestibular processing in these cortical regions is critical in linking multisensory signals from the body (personal and peripersonal space) with external (extrapersonal) space. Therefore, the vestibular system plays a critical role for neural representations of spatial aspects of bodily self-consciousness. PMID:24860446

  10. Peripheral vestibular pathology in Mondini dysplasia.

    PubMed

    Kaya, Serdar; Hızlı, Ömer; Kaya, Fatıma Kübra; Monsanto, Rafael DaCosta; Paparella, Michael M; Cureoglu, Sebahattin

    2017-01-01

    In this study, our objective was to histopathologically analyze the peripheral vestibular system in patients with Mondini dysplasia. Comparative human temporal bone study. We assessed the sensory epithelium of the human vestibular system with a focus on the number of type I and type II hair cells, as well as the total number of hair cells. We compared those numbers in our Mondini dysplasia group versus our control group. The loss of type I and type II hair cells in the cristae of the superior, lateral, and posterior semicircular canals, as well as in the saccular and utricular macula, was significantly higher in our Mondini dysplasia group than in our control group. The total number of hair cells significantly decreased in the cristae of the superior, lateral, and posterior semicircular canals, as well as in the saccular and utricular macula, in our Mondini dysplasia group. Loss of vestibular hair cells can lead to vestibular dysfunction in patients with Mondini dysplasia. NA Laryngoscope, 127:206-209, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  11. Normal and abnormal human vestibular ocular function

    NASA Technical Reports Server (NTRS)

    Peterka, R. J.; Black, F. O.

    1986-01-01

    The major motivation of this research is to understand the role the vestibular system plays in sensorimotor interactions which result in spatial disorientation and motion sickness. A second goal was to explore the range of abnormality as it is reflected in quantitative measures of vestibular reflex responses. The results of a study of vestibular reflex measurements in normal subjects and preliminary results in abnormal subjects are presented in this report. Statistical methods were used to define the range of normal responses, and determine age related changes in function.

  12. 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

  13. 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.

  14. Immediate postoperative nystagmus and vestibular symptoms after stapes surgery.

    PubMed

    Hirvonen, Timo P; Aalto, Heikki

    2013-08-01

    Vestibular disturbance is frequent, but mild even immediately after stapes surgery. Vestibular symptoms improved or disappeared quickly, and they did not correlate with nystagmus. Outpatient stapes surgery performed under local anaesthesia is a feasible approach. Vestibular symptoms are common and may prevent outpatient surgery. The time course of vestibular disturbance is unclear, and we aimed to evaluate it immediately after the operation in the recovery room. Twenty patients with otosclerosis undergoing stapedotomy were prospectively included in the study. Postoperative symptoms were collected and nystagmus was recorded with video-oculography (VOG) on average 29 min after the surgery. None of the patients had spontaneous nystagmus with gaze fixation. Nine patients (45%) had slow spontaneous horizontal nystagmus (mean slow phase velocity of 1.1°/s) in the primary position without gaze fixation. In seven of these, the nystagmus obeyed Alexander's law. Nine patients (45%) had vestibular symptoms at the end of the surgery, and four patients at the time of VOG recording. Vertigo was experienced immediately after the operation in five, floating sensation in two, and unspecific dizziness in two patients. Vestibular symptoms were mild or moderate in most patients. The occurrence of nystagmus did not correlate with vestibular symptoms (p > 0.05).

  15. 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.

  16. Altered vestibular function in fetal and newborn rats gestated in space

    NASA Technical Reports Server (NTRS)

    Ronca, A. E.; Alberts, J. R.

    1997-01-01

    Researchers evaluated vestibular development and function in rat pups flown during gestation on the NASA-NIH R1 and R2 missions. Fetal and postnatal vestibular function were examined. Altered vestibular-mediated responses in the experimental fetal pups are attributed to either direct effect of gravity on the vestibular system or indirect effects of microgravity transduced through the mother. The postnatal tests confirmed the hypothesis that the vestibular system continually adapts and responds to tonic stimulation.

  17. Mutation spectrum and differential gene expression in cystic and solid vestibular schwannoma.

    PubMed

    Zhang, Zhihua; Wang, Zhaoyan; Sun, Lianhua; Li, Xiaohua; Huang, Qi; Yang, Tao; Wu, Hao

    2014-03-01

    We sought to characterize the mutation spectrum of NF2 and the differential gene expression in cystic and solid vestibular schwannomas. We collected tumor tissue and blood samples of 31 cystic vestibular schwannomas and 114 solid vestibular schwannomas. Mutation screening of NF2 was performed in both tumor and blood DNA samples of all patients. cDNA microarray was used to analyze the differential gene expression between 11 cystic vestibular schwannomas and 6 solid vestibular schwannomas. Expression levels of top candidate genes were verified by quantitative reverse transcription PCR. NF2 mutations were identified in 34.5% of sporadic vestibular schwannomas, with all mutations being exclusively somatic. No significant difference was found between the mutation detection rates of cystic vestibular schwannoma (35.5%) and solid vestibular schwannoma (34.2%). cDNA microarray analysis detected a total of 46 differentially expressed genes between the cystic vestibular schwannoma and solid vestibular schwannoma samples. The significantly decreased expression of four top candidate genes, C1orf130, CNTF, COL4A3, and COL4A4, was verified by quantitative reverse transcription PCR. NF2 mutations are not directly involved in the cystic formation of vestibular schwannoma. In addition, the differential gene expression of cystic vestibular schwannoma reported in our study may provide useful insights into the molecular mechanism underlying this process.

  18. [Diagnosis and treatment of the most frequent vestibular syndromes].

    PubMed

    Kanashiro, Aline Mizuta Kozoroski; Pereira, Cristiana Borges; Melo, Antonio Carlos de Paiva; Scaff, Milberto

    2005-03-01

    The aims of this study were to identify the most common vestibular syndromes in a dizziness unit, and to observe their clinical aspects and response to treatment. Five hundred and fifteen patients were studied retrospectively in two institutions. Aspects of anamnesis, physical examination and the response to treatment were evaluated. The most frequent syndromes were: benign paroxysmal positioning vertigo (VPPB) (28.5%), phobic postural vertigo (11.5%), central vertigo (10.1%), vestibular neuritis (9.7%), Meniere disease (8.5%), and migraine (6.4%). A good response to treatment was observed in most patients with migraine (78.8%), VPPB (64%), vestibular neuritis (62%), Meniere disease (54.5%) and vestibular paroxismia (54.5%). On the other hand, patients with downbeat nystagmus and bilateral vestibulopathy had poor response (52.6% and 42.8%, respectively). The diagnosis of these most frequent vestibular syndromes were established through anamnesis and physical examination (with specific clinical tests for evaluation of the vestibular function). The correct diagnosis and adequate treatment are important since these syndromes may have a good prognosis.

  19. 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.

  20. 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

  1. Vestibular function assessment using the NIH Toolbox

    PubMed Central

    Schubert, Michael C.; Whitney, Susan L.; Roberts, Dale; Redfern, Mark S.; Musolino, Mark C.; Roche, Jennica L.; Steed, Daniel P.; Corbin, Bree; Lin, Chia-Cheng; Marchetti, Greg F.; Beaumont, Jennifer; Carey, John P.; Shepard, Neil P.; Jacobson, Gary P.; Wrisley, Diane M.; Hoffman, Howard J.; Furman, Gabriel; Slotkin, Jerry

    2013-01-01

    Objective: Development of an easy to administer, low-cost test of vestibular function. Methods: Members of the NIH Toolbox Sensory Domain Vestibular, Vision, and Motor subdomain teams collaborated to identify 2 tests: 1) Dynamic Visual Acuity (DVA), and 2) the Balance Accelerometry Measure (BAM). Extensive work was completed to identify and develop appropriate software and hardware. More than 300 subjects between the ages of 3 and 85 years, with and without vestibular dysfunction, were recruited and tested. Currently accepted gold standard measures of static visual acuity, vestibular function, dynamic visual acuity, and balance were performed to determine validity. Repeat testing was performed to examine reliability. Results: The DVA and BAM tests are affordable and appropriate for use for individuals 3 through 85 years of age. The DVA had fair to good reliability (0.41–0.94) and sensitivity and specificity (50%–73%), depending on age and optotype chosen. The BAM test was moderately correlated with center of pressure (r = 0.42–0.48) and dynamic posturography (r = −0.48), depending on age and test condition. Both tests differentiated those with and without vestibular impairment and the young from the old. Each test was reliable. Conclusion: The newly created DVA test provides a valid measure of visual acuity with the head still and moving quickly. The novel BAM is a valid measure of balance. Both tests are sensitive to age-related changes and are able to screen for impairment of the vestibular system. PMID:23479540

  2. The vestibular-related frontal cortex and its role in smooth-pursuit eye movements and vestibular-pursuit interactions

    PubMed Central

    Fukushima, Junko; Akao, Teppei; Kurkin, Sergei; Kaneko, Chris R.S.; Fukushima, Kikuro

    2006-01-01

    In order to see clearly when a target is moving slowly, primates with high acuity foveae use smooth-pursuit and vergence eye movements. The former rotates both eyes in the same direction to track target motion in frontal planes, while the latter rotates left and right eyes in opposite directions to track target motion in depth. Together, these two systems pursue targets precisely and maintain their images on the foveae of both eyes. During head movements, both systems must interact with the vestibular system to minimize slip of the retinal images. The primate frontal cortex contains two pursuit-related areas; the caudal part of the frontal eye fields (FEF) and supplementary eye fields (SEF). Evoked potential studies have demonstrated vestibular projections to both areas and pursuit neurons in both areas respond to vestibular stimulation. The majority of FEF pursuit neurons code parameters of pursuit such as pursuit and vergence eye velocity, gaze velocity, and retinal image motion for target velocity in frontal and depth planes. Moreover, vestibular inputs contribute to the predictive pursuit responses of FEF neurons. In contrast, the majority of SEF pursuit neurons do not code pursuit metrics and many SEF neurons are reported to be active in more complex tasks. These results suggest that FEF- and SEF-pursuit neurons are involved in different aspects of vestibular-pursuit interactions and that eye velocity coding of SEF pursuit neurons is specialized for the task condition. PMID:16917164

  3. 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.

  4. Towards a neuromorphic vestibular system.

    PubMed

    Corradi, Federico; Zambrano, Davide; Raglianti, Marco; Passetti, Giovanni; Laschi, Cecilia; Indiveri, Giacomo

    2014-10-01

    The vestibular system plays a crucial role in the sense of balance and spatial orientation in mammals. It is a sensory system that detects both rotational and translational motion of the head, via its semicircular canals and otoliths respectively. In this work, we propose a real-time hardware model of an artificial vestibular system, implemented using a custom neuromorphic Very Large Scale Integration (VLSI) multi-neuron chip interfaced to a commercial Inertial Measurement Unit (IMU). The artificial vestibular system is realized with spiking neurons that reproduce the responses of biological hair cells present in the real semicircular canals and otholitic organs. We demonstrate the real-time performance of the hybrid analog-digital system and characterize its response properties, presenting measurements of a successful encoding of angular velocities as well as linear accelerations. As an application, we realized a novel implementation of a recurrent integrator network capable of keeping track of the current angular position. The experimental results provided validate the hardware implementation via comparisons with a detailed computational neuroscience model. In addition to being an ideal tool for developing bio-inspired robotic technologies, this work provides a basis for developing a complete low-power neuromorphic vestibular system which integrates the hardware model of the neural signal processing pathway described with custom bio-mimetic gyroscopic sensors, exploiting neuromorphic principles in both mechanical and electronic aspects.

  5. Vestibular autonomic regulation (including motion sickness and the mechanism of vomiting)

    NASA Technical Reports Server (NTRS)

    Balaban, C. D.

    1999-01-01

    Autonomic manifestations of vestibular dysfunction and motion sickness are well established in the clinical literature. Recent studies of 'vestibular autonomic regulation' have focused predominantly on autonomic responses to stimulation of the vestibular sense organs in the inner ear. These studies have shown that autonomic responses to vestibular stimulation are regionally selective and have defined a 'vestibulosympathetic reflex' in animal experiments. Outside the realm of experimental preparations, however, the importance of vestibular inputs in autonomic regulation is unclear because controls for secondary factors, such as affective/emotional responses and cardiovascular responses elicited by muscle contraction and regional blood pooling, have been inadequate. Anatomic and physiologic evidence of an extensive convergence of vestibular and autonomic information in the brainstem suggests though that there may be an integrated representation of gravitoinertial acceleration from vestibular, somatic, and visceral receptors for somatic and visceral motor control. In the case of vestibular dysfunction or motion sickness, the unpleasant visceral manifestations (e.g. epigastric discomfort, nausea or vomiting) may contribute to conditioned situational avoidance and the development of agoraphobia.

  6. 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.

  7. Development and regeneration of vestibular hair cells in mammals.

    PubMed

    Burns, Joseph C; Stone, Jennifer S

    2017-05-01

    Vestibular sensation is essential for gaze stabilization, balance, and perception of gravity. The vestibular receptors in mammals, Type I and Type II hair cells, are located in five small organs in the inner ear. Damage to hair cells and their innervating neurons can cause crippling symptoms such as vertigo, visual field oscillation, and imbalance. In adult rodents, some Type II hair cells are regenerated and become re-innervated after damage, presenting opportunities for restoring vestibular function after hair cell damage. This article reviews features of vestibular sensory cells in mammals, including their basic properties, how they develop, and how they are replaced after damage. We discuss molecules that control vestibular hair cell regeneration and highlight areas in which our understanding of development and regeneration needs to be deepened. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. 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

  9. The role of the vestibular system in manual target localization

    NASA Technical Reports Server (NTRS)

    Barry, Susan R.; Mueller, S. Alyssa

    1995-01-01

    Astronauts experience perceptual and sensory-motor disturbances during spaceflight and immediately after return to the 1-g environment of Earth. During spaceflight, sensory information from the eyes, limbs and vestibular organs is reinterpreted by the central nervous system so that astronauts can produce appropriate body movements in microgravity. Alterations in sensory-motor function may affect eye-head-hand coordination and, thus, the crewmember's ability to manually locate objects in extrapersonal space. Previous reports have demonstrated that crewmembers have difficulty in estimating joint and limb position and in pointing to memorized target positions on orbit and immediately postflight. One set of internal cues that may assist in the manual localization of objects is information from the vestibular system. This system contributes to our sense of the body's position in space by providing information on head position and movement and the orientation of the body with respect to gravity. Research on the vestibular system has concentrated on its role in oculo-motor control. Little is known about the role that vestibular information plays in manual motor control, such as reaching and pointing movements. Since central interpretation of vestibular information is altered in microgravity, it is important to determine its role in this process. This summer, we determined the importance of vestibular information in a subject's ability to point accurately toward a target in extrapersonal space. Subjects were passively rotated across the earth-vertical axis and then asked to point back to a previously-seen target. In the first paradigm, the subjects used both visual and vestibular cues for the pointing response, while, in the second paradigm, subjects used only vestibular information. Subjects were able to point with 85 percent accuracy to a target using vestibular information alone. We infer from this result that vestibular input plays a role in the spatial programming of

  10. Current evidence of peripheral vestibular symptoms secondary to otitis media.

    PubMed

    Monsanto, Rafael da Costa; Kasemodel, Ana Luiza Papi; Tomaz, Andreza; Paparella, Michael M; Penido, Norma de Oliveira

    2018-05-06

    The association between otitis media and vestibular symptoms has been hypothesized in the past. Thus, in this study, we aimed to critically analyze (based in a systematic review of the literature) whether patients who have otitis media are at greater risk of developing vestibular impairment or not. We performed a systematic review of the literature and identified potentially relevant articles reporting vestibular symptoms and results of vestibular function tests in patients with otitis media through searches of the PubMED, Web of Science, Scopus, and Google Scholar databases. The quality of the final set of records was assessed using the "Newcaste-Ottawa Scale". Of the 2334 records searched, 43 met our inclusion and exclusion criteria, and those included 2250 patients. The records comprised 20 longitudinal studies, 21 cross-sectional studies, and 2 case reports. Regarding the type of otitis media studied, 25 examined vestibular impairment in otitis media with effusion, 6 acute otitis media, and 12 chronic otitis media. Results of anamnesis, clinical exams, and several vestibular function tests are reported and critically discussed. Most studies evaluating the association between otitis media and vestibular symptoms have potential methodological flaws. Clinical evidence suggests that patients with otitis media have increased chances for having vestibular symptoms, delayed acquisition of developmental milestones, and abnormalities in several vestibular function tests as compared with controls. Future studies with rigorous methodology aiming to assess the clinical significance (and prognostic factors) of the association between otitis media and vestibular impairment are warranted. Key message Several studies demonstrated long-term sequelae secondary to otitis media. However, the evidence supporting those assumptions are based in low-quality evidence. Thus, better structured studies are warranted to better understand the clinical relevance of such association.

  11. 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.

  12. Sensory processing in the vestibular nuclei during active head movements

    NASA Technical Reports Server (NTRS)

    Gdowski, G. T.; Boyle, R.; McCrea, R. A.; Peterson, B. W. (Principal Investigator)

    2000-01-01

    Many secondary vestibular neurons are sensitive to head on trunk rotation during reflex-induced and voluntary head movements. During passive whole body rotation the interaction of head on trunk signals related to the vestibulo-collic reflex with vestibular signals increases the rotational gain of many secondary vestibular neurons, including many that project to the spinal cord. In some units, the sensitivity to head on trunk and vestibular input is matched and the resulting interaction produces an output that is related to the trunk velocity in space. In other units the head on trunk inputs are stronger and the resulting interaction produces an output that is larger during the reflex. During voluntary head movements, inputs related to head on trunk movement combine destructively with vestibular signals, and often cancel the sensory reafferent consequences of self-generated movements. Cancellation of sensory vestibular signals was observed in all of the antidromically identified secondary vestibulospinal units, even though many of these units were not significantly affected by reflexive head on trunk movements. The results imply that the inputs to vestibular neurons related to head on trunk rotation during reflexive and voluntary movements arise from different sources. We suggest that the relative strength of reflexive head on trunk input to different vestibular neurons might reflect the different functional roles they have in controlling the posture of the neck and body.

  13. 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

  14. The prevalence of vestibular symptoms in migraine or tension-type headache.

    PubMed

    Akdal, Gülden; Ozge, Aynur; Ergör, Gül

    2013-01-01

    We assessed frequency of vestibular symptoms in Headache Clinic patients over 10 years. A descriptive study of 5111 consecutive patients with tension-type headache or migraine, analyzed for dizziness/ vertigo accompanying headache and for a lifetime history of motion-sickness, cyclic vomiting, recurrent abdominal pain or atopy. Migraine patients were re-grouped as those with vestibular symptoms (dizziness/vertigo or motion sickness) and those without and their data then re-analyzed. There were 1880 migraine patients and 3231 tension-type headache patients. Significantly more migraine patients than tension-type headache patients experienced vestibular symptoms (p< 0.0001). The migraine with vestibular symptoms group was significantly younger (p< 0.05) had more aura, more phonophobia with migraine attacks (p< 0.0001). Menstruation and reported sleep problems impacted on headaches. While past history of cyclical vomiting, recurrent abdominal pain or atopy was about twice as common in migraine with aura and it was also more common in migraine with vestibular symptoms than migraine without vestibular symptoms. Vestibular symptoms are common in migraine patients. Migraine with vestibular symptoms might constitute a special group, one more likely to have had cyclic vomiting, recurrent abdominal pain or atopy.

  15. Vestibular compensation after vestibular schwannoma surgery: normalization of the subjective visual vertical and disability.

    PubMed

    Batuecas-Caletrio, Angel; Santacruz-Ruiz, Santiago; Muñoz-Herrera, Angel; Sousa, Pablo; Otero, Alvaro; Perez-Fernandez, Nicolas

    2013-05-01

    The degree of caloric weakness before surgery influences faster or slower recovery of patients undergoing vestibular schwannoma surgery. The Dizziness Handicap Inventory (DHI) is a good index to show the recovery of patients as it relates directly to an improvement or not of the subjective visual vertical (SVV). To evaluate the process of recovery of patients as measured by the SVV and the DHI after surgical removal of vestibular schwannoma. We studied 24 consecutive patients of the University Hospital of Salamanca who underwent vestibular schwannoma surgery. We assessed age, tumour size, degree of canalicular weakness and preoperative SVV, and their relationship with DHI and SVV at discharge and also at 1, 3 and 6 months postoperatively. Patients with lesser degrees of caloric weakness took longer to normalize SVV than those with a higher caloric weakness before surgery (p < 0.05). There was a significant correlation between DHI and improvements in SVV with time. The differences disappeared in 6 months where all patients, with greater or lesser degree of caloric weakness, had the same results.

  16. The intrinsic organization of the vestibular complex: evidence for internuclear connectivity.

    PubMed

    Rubertone, J A; Mehler, W R; Cox, G E

    1983-03-14

    The HRP anterograde and retrograde labeling techniques provide evidence for extensive internuclear connectivity within the vestibular complex. Specifically: (1) the superior vestibular nucleus is topographically and reciprocally related to the spinal (spr) and medial vestibular nuclei (mv); (2) the lateral vestibular nucleus (lv) is reciprocally related to the mv, and (3) the lv receives afferent fibers from the spv but does not reciprocate this input.

  17. Symptoms Associated with Vestibular Impairment in Veterans with Posttraumatic Stress Disorder

    PubMed Central

    2016-01-01

    Posttraumatic stress disorder (PTSD) is a chronic and disabling, anxiety disorder resulting from exposure to life threatening events such as a serious accident, abuse or combat (DSM IV definition). Among veterans with PTSD, a common complaint is dizziness, disorientation and/or postural imbalance in environments such as grocery stores and shopping malls. The etiology of these symptoms in PTSD is poorly understood and some attribute them to anxiety or traumatic brain injury. There is a possibility that an impaired vestibular system may contribute to these symptoms since, symptoms of an impaired vestibular system include dizziness, disorientation and postural imbalance. To our knowledge, this is the first report to describe the nature of vestibular related symptoms in veterans with and without PTSD. We measured PTSD symptoms using the Posttraumatic Stress Disorder Checklist (PCL-C) and compared it to responses on vestibular function scales including the Dizziness Handicap Inventory (DHI), the Vertigo Symptom Scale Short Form (VSS-SF), the Chambless Mobility Inventory (CMI), and the Neurobehavioral Scale Inventory (NSI) in order to identify vestibular-related symptoms. Our findings indicate that veterans with worse PTSD symptoms report increased vestibular related symptoms. Additionally veterans with PTSD reported 3 times more dizziness related handicap than veterans without PTSD. Veterans with increased avoidance reported more vertigo and dizziness related handicap than those with PTSD and reduced avoidance. We describe possible contributing factors to increased reports of vestibular symptoms in PTSD, namely, anxiety, a vestibular component as well as an interactive effect of anxiety and vestibular impairment. We also present some preliminary analyses regarding the contribution of TBI. This data suggests possible evidence for vestibular symptom reporting in veterans with PTSD, which may be explained by possible underlying vestibular impairment, worthy of further

  18. 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

  19. Cognitive Rehabilitation in Bilateral Vestibular Patients: A Computational Perspective.

    PubMed

    Ellis, Andrew W; Schöne, Corina G; Vibert, Dominique; Caversaccio, Marco D; Mast, Fred W

    2018-01-01

    There is evidence that vestibular sensory processing affects, and is affected by, higher cognitive processes. This is highly relevant from a clinical perspective, where there is evidence for cognitive impairments in patients with peripheral vestibular deficits. The vestibular system performs complex probabilistic computations, and we claim that understanding these is important for investigating interactions between vestibular processing and cognition. Furthermore, this will aid our understanding of patients' self-motion perception and will provide useful information for clinical interventions. We propose that cognitive training is a promising way to alleviate the debilitating symptoms of patients with complete bilateral vestibular loss (BVP), who often fail to show improvement when relying solely on conventional treatment methods. We present a probabilistic model capable of processing vestibular sensory data during both passive and active self-motion. Crucially, in our model, knowledge from multiple sources, including higher-level cognition, can be used to predict head motion. This is the entry point for cognitive interventions. Despite the loss of sensory input, the processing circuitry in BVP patients is still intact, and they can still perceive self-motion when the movement is self-generated. We provide computer simulations illustrating self-motion perception of BVP patients. Cognitive training may lead to more accurate and confident predictions, which result in decreased weighting of sensory input, and thus improved self-motion perception. Using our model, we show the possible impact of cognitive interventions to help vestibular rehabilitation in patients with BVP.

  20. Assessment of Vestibular Rehabilitation Therapy Training and Practice Patterns.

    PubMed

    Bush, Matthew L; Dougherty, William

    2015-08-01

    Vestibular rehabilitation therapy (VRT) can benefit patients with a variety of balance and vestibular disorders. This expanding field requires knowledgeable and experienced therapists; however, the practice and experience of those providing this care may vary greatly. The purpose of this study was to analyze variations in training and practice patterns among practicing vestibular rehabilitation therapists. Case-controlled cohort study. Investigation of outpatient physical therapy and audiology practices that offer vestibular rehabilitation conducted by a tertiary academic referral center. Questionnaire-based investigation of level of training in vestibular disorders and therapy, practice patterns of vestibular rehabilitation, and referral sources for VRT patients. We identified 27 subjects within the state of Kentucky who practice vestibular rehabilitation and the questionnaire response rate was 63%. Responses indicated that 53% of respondents had no training in VRT during their professional degree program. Attendance of a course requiring demonstration of competence and techniques was 24% of participants. The development of VRT certification was significantly more favored by those who attended such courses compared with those who did not (p = 0.01). 50% of therapists have direct access to patients without physician referrals. There is a wide range of educational background and training among those practicing VRT. This variability in experience may affect care provided within some communities. Certification is not necessary for the practice of VRT but the development of certification is favored among some therapists to improve standardization of practice of this important specialty.

  1. Visual Dependency and Dizziness after Vestibular Neuritis

    PubMed Central

    Cousins, Sian; Cutfield, Nicholas J.; Kaski, Diego; Palla, Antonella; Seemungal, Barry M.; Golding, John F.; Staab, Jeffrey P.; Bronstein, Adolfo M.

    2014-01-01

    Symptomatic recovery after acute vestibular neuritis (VN) is variable, with around 50% of patients reporting long term vestibular symptoms; hence, it is essential to identify factors related to poor clinical outcome. Here we investigated whether excessive reliance on visual input for spatial orientation (visual dependence) was associated with long term vestibular symptoms following acute VN. Twenty-eight patients with VN and 25 normal control subjects were included. Patients were enrolled at least 6 months after acute illness. Recovery status was not a criterion for study entry, allowing recruitment of patients with a full range of persistent symptoms. We measured visual dependence with a laptop-based Rod-and-Disk Test and severity of symptoms with the Dizziness Handicap Inventory (DHI). The third of patients showing the worst clinical outcomes (mean DHI score 36–80) had significantly greater visual dependence than normal subjects (6.35° error vs. 3.39° respectively, p = 0.03). Asymptomatic patients and those with minor residual symptoms did not differ from controls. Visual dependence was associated with high levels of persistent vestibular symptoms after acute VN. Over-reliance on visual information for spatial orientation is one characteristic of poorly recovered vestibular neuritis patients. The finding may be clinically useful given that visual dependence may be modified through rehabilitation desensitization techniques. PMID:25233234

  2. Vestibular-visual interactions in flight simulators

    NASA Technical Reports Server (NTRS)

    Clark, B.

    1977-01-01

    All 139 research papers published under this ten-year program are listed. Experimental work was carried out at the Ames Research Center involving man's sensitivity to rotational acceleration, and psychophysical functioning of the semicircular canals; vestibular-visual interactions and effects of other sensory systems were studied in flight simulator environments. Experiments also dealt with the neurophysiological vestibular functions of animals, and flight management investigations of man-vehicle interactions.

  3. Regeneration of hair cells in the mammalian vestibular system.

    PubMed

    Li, Wenyan; You, Dan; Chen, Yan; Chai, Renjie; Li, Huawei

    2016-06-01

    Hair cells regenerate throughout the lifetime of non-mammalian vertebrates, allowing these animals to recover from hearing and balance deficits. Such regeneration does not occur efficiently in humans and other mammals. Thus, balance deficits become permanent and is a common sensory disorder all over the world. Since Forge and Warchol discovered the limited spontaneous regeneration of vestibular hair cells after gentamicininduced damage in mature mammals, significant efforts have been exerted to trace the origin of the limited vestibular regeneration in mammals after hair cell loss. Moreover, recently many strategies have been developed to promote the hair cell regeneration and subsequent functional recovery of the vestibular system, including manipulating the Wnt, Notch and Atoh1. This article provides an overview of the recent advances in hair cell regeneration in mammalian vestibular epithelia. Furthermore, this review highlights the current limitations of hair cell regeneration and provides the possible solutions to regenerate functional hair cells and to partially restore vestibular function.

  4. Diversity of head shaking nystagmus in peripheral vestibular disease.

    PubMed

    Kim, Min-Beom; Huh, Se Hyung; Ban, Jae Ho

    2012-06-01

    To evaluate the characteristics of head shaking nystagmus in various peripheral vestibular diseases. Retrospective case series. Tertiary referral center. Data of 235 patients with peripheral vestibular diseases including vestibular neuritis, Ménière's disease, and benign paroxysmal positional vertigo, were retrospectively analyzed. All subjects presented between August 2009 and July 2010. Patients were tested for vestibular function including head shaking nystagmus and caloric information. Regarding vestibular neuritis, all tests were again performed during the 1-month follow-up. Head shaking nystagmus was classified as monophasic or biphasic and, according to the affected ear, was divided as ipsilesional or contralesional. Of the 235 patients, 87 patients revealed positive head shaking nystagmus. According to each disease, positive rates of head shaking nystagmus were as follows: 35 (100%) of 35 cases of vestibular neuritis, 11 (68.8%) of 16 cases of Ménière's disease, and 41 (22.2%) of 184 cases of benign paroxysmal positional vertigo. All cases of vestibular neuritis initially presented as a monophasic, contralesional beating, head shaking nystagmus. However, 1 month after first visit, the direction of nystagmus was changed to biphasic (contralesional first then ipsilesional beating) in 25 cases (72.5%) but not in 10 cases (27.5%). There was a significant correlation between the degree of initial caloric weakness and the biphasic conversion of head shaking nystagmus (p = 0.02). In 72.5% of vestibular neuritis cases, head shaking nystagmus was converted to biphasic during the subacute period. The larger the initial canal paresis was present, the more frequent the biphasic conversion of head shaking nystagmus occurred. However, Ménière's disease and benign paroxysmal positional vertigo did not have specific patterns of head shaking nystagmus.

  5. Vestibular rehabilitation therapy: review of indications, mechanisms, and key exercises.

    PubMed

    Han, Byung In; Song, Hyun Seok; Kim, Ji Soo

    2011-12-01

    Vestibular rehabilitation therapy (VRT) is an exercise-based treatment program designed to promote vestibular adaptation and substitution. The goals of VRT are 1) to enhance gaze stability, 2) to enhance postural stability, 3) to improve vertigo, and 4) to improve activities of daily living. VRT facilitates vestibular recovery mechanisms: vestibular adaptation, substitution by the other eye-movement systems, substitution by vision, somatosensory cues, other postural strategies, and habituation. The key exercises for VRT are head-eye movements with various body postures and activities, and maintaining balance with a reduced support base with various orientations of the head and trunk, while performing various upper-extremity tasks, repeating the movements provoking vertigo, and exposing patients gradually to various sensory and motor environments. VRT is indicated for any stable but poorly compensated vestibular lesion, regardless of the patient's age, the cause, and symptom duration and intensity. Vestibular suppressants, visual and somatosensory deprivation, immobilization, old age, concurrent central lesions, and long recovery from symptoms, but there is no difference in the final outcome. As long as exercises are performed several times every day, even brief periods of exercise are sufficient to facilitate vestibular recovery. Here the authors review the mechanisms and the key exercises for each of the VRT goals.

  6. Vestibular Rehabilitation Therapy: Review of Indications, Mechanisms, and Key Exercises

    PubMed Central

    Song, Hyun Seok; Kim, Ji Soo

    2011-01-01

    Vestibular rehabilitation therapy (VRT) is an exercise-based treatment program designed to promote vestibular adaptation and substitution. The goals of VRT are 1) to enhance gaze stability, 2) to enhance postural stability, 3) to improve vertigo, and 4) to improve activities of daily living. VRT facilitates vestibular recovery mechanisms: vestibular adaptation, substitution by the other eye-movement systems, substitution by vision, somatosensory cues, other postural strategies, and habituation. The key exercises for VRT are head-eye movements with various body postures and activities, and maintaining balance with a reduced support base with various orientations of the head and trunk, while performing various upper-extremity tasks, repeating the movements provoking vertigo, and exposing patients gradually to various sensory and motor environments. VRT is indicated for any stable but poorly compensated vestibular lesion, regardless of the patient's age, the cause, and symptom duration and intensity. Vestibular suppressants, visual and somatosensory deprivation, immobilization, old age, concurrent central lesions, and long recovery from symptoms, but there is no difference in the final outcome. As long as exercises are performed several times every day, even brief periods of exercise are sufficient to facilitate vestibular recovery. Here the authors review the mechanisms and the key exercises for each of the VRT goals. PMID:22259614

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. Gap junction systems in the rat vestibular labyrinth: immunohistochemical and ultrastructural analysis.

    PubMed

    Kikuchi, T; Adams, J C; Paul, D L; Kimura, R S

    1994-09-01

    The distribution of gap junctions within the vestibular labyrinth was investigated using immunohistochemistry and transmission electron microscopy. Connexin26-like immunoreactivity was observed among supporting cells in each vestibular sensory epithelium. Reaction product was also present in the transitional epithelium of each vestibular endorgan and in the planum semilunatum of crista ampullaris. No connexin26-like immunoreactivity was observed among thin wall epithelial cells or among vestibular dark cells. In addition, fibrocytes within vestibular connective tissue were positively immunostained. Reaction product was also detected in the melanocyte area just beneath dark cells. Ultrastructural observations indicated that a gap junction network of vestibular supporting cells extends to the transitional epithelium and planum semilunatum and forms an isolated epithelial cell gap junction system in each vestibular endorgan. In contrast, no gap junctions were found among wall epithelial cells or among dark cells. Fibrocytes and melanocytes were coupled by gap junctions and belong to the connective tissue cell gap junction system, which is continuous throughout the vestibular system and the cochlea. The possible functional significance of these gap junction systems is discussed.

  12. Assessment of Vestibular Rehabilitation Therapy Training and Practice Patterns

    PubMed Central

    Bush, Matthew L.; Dougherty, William

    2015-01-01

    Objective Vestibular rehabilitation therapy (VRT) can benefit patients with a variety of balance and vestibular disorders. This expanding field requires knowledgeable and experienced therapists; however, the practice and experience of those providing this care may vary greatly. The purpose of this study was to analyze variations in training and practice patterns among practicing vestibular rehabilitation therapists. Study Design Case-controlled cohort study Setting Investigation of outpatient physical therapy and audiology practices that offer vestibular rehabilitation conducted by a tertiary academic referral center. Main Outcome Measure Questionnaire-based investigation of level of training in vestibular disorders and therapy, practice patterns of vestibular rehabilitation, and referral sources for VRT patients. Results We identified 27 subjects within the state of Kentucky who practice vestibular rehabilitation and the questionnaire response rate was 63%. Responses indicated that 53% of respondents had no training in VRT during their professional degree program. Attendance of a course requiring demonstration of competence and techniques was 24% of participants. The development of VRT certification was significantly more favored by those who attended such courses compared with those who did not (p=0.01). 50% of therapists have direct access to patients without physician referrals. Conclusions There is a wide range of educational background and training among those practicing VRT. This variability in experience may affect care provided within some communities. Certification is not necessary for the practice of VRT but the development of certification is favored among some therapists to improve standardization of practice of this important specialty. PMID:25700790

  13. Vestibular animal models: contributions to understanding physiology and disease.

    PubMed

    Straka, Hans; Zwergal, Andreas; Cullen, Kathleen E

    2016-04-01

    Our knowledge of the vestibular sensory system, its functional significance for gaze and posture stabilization, and its capability to ensure accurate spatial orientation perception and spatial navigation has greatly benefitted from experimental approaches using a variety of vertebrate species. This review summarizes the attempts to establish the roles of semicircular canal and otolith endorgans in these functions followed by an overview of the most relevant fields of vestibular research including major findings that have advanced our understanding of how this system exerts its influence on reflexive and cognitive challenges encountered during daily life. In particular, we highlight the contributions of different animal models and the advantage of using a comparative research approach. Cross-species comparisons have established that the morpho-physiological properties underlying vestibular signal processing are evolutionarily inherent, thereby disclosing general principles. Based on the documented success of this approach, we suggest that future research employing a balanced spectrum of standard animal models such as fish/frog, mouse and primate will optimize our progress in understanding vestibular processing in health and disease. Moreover, we propose that this should be further supplemented by research employing more "exotic" species that offer unique experimental access and/or have specific vestibular adaptations due to unusual locomotor capabilities or lifestyles. Taken together this strategy will expedite our understanding of the basic principles underlying vestibular computations to reveal relevant translational aspects. Accordingly, studies employing animal models are indispensible and even mandatory for the development of new treatments, medication and technical aids (implants) for patients with vestibular pathologies.

  14. Otolith-Canal Convergence In Vestibular Nuclei Neurons

    NASA Technical Reports Server (NTRS)

    Dickman, J. David; Si, Xiao-Hong

    2002-01-01

    The current final report covers the period from June 1, 1999 to May 31, 2002. The primary objective of the investigation was to determine how information regarding head movements and head position relative to gravity is received and processed by central vestibular nuclei neurons in the brainstem. Specialized receptors in the vestibular labyrinths of the inner ear function to detect angular and linear accelerations of the head, with receptors located in the semicircular canals transducing rotational head movements and receptors located in the otolith organs transducing changes in head position relative to gravity or linear accelerations of the head. The information from these different receptors is then transmitted to central vestibular nuclei neurons which process the input signals, then project the appropriate output information to the eye, head, and body musculature motor neurons to control compensatory reflexes. Although a number of studies have reported on the responsiveness of vestibular nuclei neurons, it has not yet been possible to determine precisely how these cells combine the information from the different angular and linear acceleration receptors into a correct neural output signal. In the present project, rotational and linear motion stimuli were separately delivered while recording responses from vestibular nuclei neurons that were characterized according to direct input from the labyrinth and eye movement sensitivity. Responses from neurons receiving convergent input from the semicircular canals and otolith organs were quantified and compared to non-convergent neurons.

  15. Vertigo with sudden hearing loss: audio-vestibular characteristics.

    PubMed

    Pogson, Jacob M; Taylor, Rachael L; Young, Allison S; McGarvie, Leigh A; Flanagan, Sean; Halmagyi, G Michael; Welgampola, Miriam S

    2016-10-01

    Acute vertigo with sudden sensorineural hearing loss (SSNHL) is a rare clinical emergency. Here, we report the audio-vestibular test profiles of 27 subjects who presented with these symptoms. The vestibular test battery consisted of a three-dimensional video head impulse test (vHIT) of semicircular canal function and recording ocular and cervical vestibular-evoked myogenic potentials (oVEMP, cVEMP) to test otolith dysfunction. Unlike vestibular neuritis, where the horizontal and anterior canals with utricular function are more frequently impaired, 74 % of subjects with vertigo and SSNHL demonstrated impairment of the posterior canal gain (0.45 ± 0.20). Only 41 % showed impairment of the horizontal canal gains (0.78 ± 0.27) and 30 % of the anterior canal gains (0.79 ± 0.26), while 38 % of oVEMPs [asymmetry ratio (AR) = 41.0 ± 41.3 %] and 33 % of cVEMPs (AR = 47.3 ± 41.2 %) were significantly asymmetrical. Twenty-three subjects were diagnosed with labyrinthitis/labyrinthine infarction in the absence of evidence for an underlying pathology. Four subjects had a definitive diagnosis [Ramsay Hunt Syndrome, vestibular schwannoma, anterior inferior cerebellar artery (AICA) infarction, and traction injury]. Ischemia involving the common-cochlear or vestibulo-cochlear branches of the labyrinthine artery could be the simplest explanation for vertigo with SSNHL. Audio-vestibular tests did not provide easy separation between ischaemic and non-ischaemic causes of vertigo with SSNHL.

  16. Magnetic vestibular stimulation modulates default mode network fluctuations.

    PubMed

    Boegle, Rainer; Stephan, Thomas; Ertl, Matthias; Glasauer, Stefan; Dieterich, Marianne

    2016-02-15

    Strong magnetic fields (>1 Tesla) can cause dizziness and it was recently shown that healthy subjects (resting in total darkness) developed a persistent nystagmus even when remaining completely motionless within a MR tomograph. Consequently, it was speculated that this magnetic vestibular stimulation (MVS) might influence fMRI results, as nystagmus is indicative of an imbalance in the vestibular system, potentially influencing other systems via multisensory vestibular interactions. The objective of our study was to investigate whether MVS does indeed modulate BOLD signal fluctuations. We recorded eye movements, as well as, resting-state fMRI of 30 volunteers in darkness at 1.5 T and 3.0 T to answer the question whether MVS modulated parts of the default mode resting-state network (DMN) in accordance with the Lorentz-force model for MVS, while distinguishing this from the known signal increase due to field strength related imaging effects. Our results showed that modulation of the default mode network occurred mainly in areas associated with vestibular and ocular motor function, and was in accordance with the Lorentz-force model, i.e., double than the expected signal scaling due to field strength alone. We discuss the implications of our findings for the interpretation of studies using resting-state fMRI, especially those concerning vestibular research. We conclude that MVS needs to be considered in vestibular research to avoid biased results, but it might also offer the possibility of manipulating network dynamics and may thus help in studying the brain as a dynamical system. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. To develop behavioral tests of vestibular functioning in the Wistar rat

    NASA Technical Reports Server (NTRS)

    Nielson, H. C.

    1980-01-01

    Two tests of vestibular functioning in the rat were developed. The first test was the water maze. In the water maze the rat does not have the normal proprioceptive feedback from its limbs to help it maintain its orientation, and must rely primarily on the sensory input from its visual and vestibular systems. By altering lighting conditions and visual cues the vestibular functioning without visual cues was assessed. Whether there was visual compensation for some vestibular dysfunction was determined. The second test measured vestibular functioning of the rat's behavior on a parallel swing. In this test the rat's postural adjustments while swinging on the swing with the otoliths being stimulated were assessed. Less success was achieved in developing the parallel swing as a test of vestibular functioning than with the water maze. The major problem was incorrect initial assumptions of what the rat's probable behavior on the parallel swing would be.

  18. Vestibular signals in primate cortex for self-motion perception.

    PubMed

    Gu, Yong

    2018-04-21

    The vestibular peripheral organs in our inner ears detect transient motion of the head in everyday life. This information is sent to the central nervous system for automatic processes such as vestibulo-ocular reflexes, balance and postural control, and higher cognitive functions including perception of self-motion and spatial orientation. Recent neurophysiological studies have discovered a prominent vestibular network in the primate cerebral cortex. Many of the areas involved are multisensory: their neurons are modulated by both vestibular signals and visual optic flow, potentially facilitating more robust heading estimation through cue integration. Combining psychophysics, computation, physiological recording and causal manipulation techniques, recent work has addressed both the encoding and decoding of vestibular signals for self-motion perception. Copyright © 2018. Published by Elsevier Ltd.

  19. The Role of Cervical and Ocular Vestibular Evoked Myogenic Potentials in the Assessment of Patients with Vestibular Schwannomas

    PubMed Central

    Chiarovano, Elodie; Darlington, Cynthia; Vidal, Pierre-Paul; Lamas, Georges; de Waele, Catherine

    2014-01-01

    Objectives To investigate the clinical utility of VEMPs in patients suffering from unilateral vestibular schwannoma (VS) and to determine the optimal stimulation parameter (air conducted sound, bone conducted vibration) for evaluating the function of the vestibular nerve. Methods Data were obtained in 63 patients with non-operated VS, and 20 patients operated on VS. Vestibular function was assessed by caloric, cervical and ocular VEMP testing. 37/63 patients with conclusive ACS ocular VEMPs responses were studied separately. Results In the 63 non-operated VS patients, cVEMPs were abnormal in 65.1% of patients in response to AC STB and in 49.2% of patients to AC clicks. In the 37/63 patients with positive responses from the unaffected side, oVEMPs were abnormal in 75.7% of patients with ACS, in 67.6% with AFz and in 56.8% with mastoid BCV stimulation. In 16% of the patients, VEMPs were the only abnormal test (normal caloric and normal hearing). Among the 26 patients who did not show oVEMP responses on either side with ACS, oVEMPs responses could be obtained with AFz (50%) and with mastoid stimulation (89%). Conclusions The VEMP test demonstrated significant clinical value as it yielded the only abnormal test results in some patients suffering from a unilateral vestibular schwannoma. For oVEMPs, we suggest that ACS stimulation should be the initial test. In patients who responded to ACS and who had normal responses, BCV was not required. In patients with abnormal responses on the affected side using ACS, BCV at AFz should be used to confirm abnormal function of the superior vestibular nerve. In patients who exhibited no responses on either side to ACS, BCV was the only approach allowing assessment of the function of the superior vestibular nerve. We favor using AFz stimulation first because it is easier to perform in clinical practice than mastoid stimulation. PMID:25137289

  20. Vestibular dysfunction in Turner syndrome: a case report.

    PubMed

    Baxter, Michael; Agrawal, Yuri

    2014-02-01

    Turner syndrome is a well-known cause of sensorineural hearing loss, and the lack of estrogen has been implicated in cochlear dysfunction. It has never been associated with vestibular dysfunction. We report a case of a patient with Turner syndrome who was found to have bilateral vestibular dysfunction based on video-oculography (VOG) testing. A single patient with a history of Turner syndrome who was found to have significant bilateral vestibular dysfunction. After noticing a deficit in the vestibulo-ocular reflexes on qualitative horizontal head impulse examination, the patient underwent VOG testing. VOG testing quantatively measures angular vestibulo-ocular reflex (AVOR) gain in the horizontal semicircular canal plane. AVOR gain represents the eye movement response to a head movement; in normal individuals the eye movement is fully compensatory and gain values are close to unity. VOG results showed AVOR gains of 0.29 and 0.36 on the right and left sides, respectively. We have presented a case of a woman with Turner syndrome with asymptomatic vestibular dysfunction demonstrated with VOG testing. Although there is a documented relationship between Turner syndrome and sensorineural hearing loss, there are no previous studies or case reports linking Turner syndrome and vestibular dysfunction. Additional research and added vigilance in monitoring Turner syndrome patients may be warranted.

  1. Role of vestibular information in initiation of rapid postural responses

    NASA Technical Reports Server (NTRS)

    Runge, C. F.; Shupert, C. L.; Horak, F. B.; Zajac, F. E.; Peterson, B. W. (Principal Investigator)

    1998-01-01

    Patients with bilateral vestibular loss have difficulty maintaining balance without stepping when standing in tandem, on compliant surfaces, across narrow beams, or on one foot, especially with eyes closed. Normal individuals (with no sensory impairment) maintain balance in these tasks by employing quick, active hip rotation (a "hip strategy"). The absence of a hip strategy in vestibular patients responding to translations of a short support surface has previously been taken as evidence that the use of hip strategy requires an intact vestibular system. However, many tasks requiring hip strategy alter one or a combination of important system characteristics, such as initial state of the body (tandem stance), dynamics (compliant surfaces), or biomechanical limits of stability (narrow beams). Therefore, the balance deficit in these tasks may result from a failure to account for these support surface alterations when planning and executing sensorimotor responses. In this study, we tested the hypothesis that vestibular information is critical to trigger a hip strategy even on an unaltered support surface, which imposes no changes on the system characteristics. We recorded the postural responses of vestibular patients and control subjects with eyes closed to rearward support surface translations of varying velocity, in erect stance on a firm, flat surface. Subjects were instructed to maintain balance without stepping, if possible. Faster translation velocities (25 cm/s or more) produced a consistent pattern of early hip torque (first 400 ms) in control subjects (i.e., a hip strategy). Most of the patients with bilateral vestibular loss responded to the same translation velocities with similar torques. Contrary to our hypothesis, we conclude that vestibular function is not necessary to trigger a hip strategy. We postulate, therefore, that the balance deficit previously observed in vestibular patients during postural tasks that elicit a hip strategy may have been due to

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. The History and Evolution of Surgery on the Vestibular Labyrinth.

    PubMed

    Naples, James G; Eisen, Marc D

    2016-11-01

    The history of surgery on the vestibular labyrinth is rich but sparsely documented in the literature. The story begins over a century ago with the labyrinthectomy in an era that consisted exclusively of ablative surgery for infection or vertigo. Improved understanding of vestibular physiology and pathology produced an era of selective ablation and hearing preservation that includes semicircular canal occlusion for benign paroxysmal positional vertigo. An era of restoration began with a discovery of superior semicircular canal dehiscence and its repair. The final era of vestibular replacement is upon us as the possibility of successful prosthetic vestibular implantation becomes reality. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

  9. Retinoic acid deficiency impairs the vestibular function.

    PubMed

    Romand, Raymond; Krezel, Wojciech; Beraneck, Mathieu; Cammas, Laura; Fraulob, Valérie; Messaddeq, Nadia; Kessler, Pascal; Hashino, Eri; Dollé, Pascal

    2013-03-27

    The retinaldehyde dehydrogenase 3 (Raldh3) gene encodes a major retinoic acid synthesizing enzyme and is highly expressed in the inner ear during embryogenesis. We found that mice deficient in Raldh3 bear severe impairment in vestibular functions. These mutant mice exhibited spontaneous circling/tilted behaviors and performed poorly in several vestibular-motor function tests. In addition, video-oculography revealed a complete loss of the maculo-ocular reflex and a significant reduction in the horizontal angular vestibulo-ocular reflex, indicating that detection of both linear acceleration and angular rotation were compromised in the mutants. Consistent with these behavioral and functional deficiencies, morphological anomalies, characterized by a smaller vestibular organ with thinner semicircular canals and a significant reduction in the number of otoconia in the saccule and the utricle, were consistently observed in the Raldh3 mutants. The loss of otoconia in the mutants may be attributed, at least in part, to significantly reduced expression of Otop1, which encodes a protein known to be involved in calcium regulation in the otolithic organs. Our data thus reveal a previously unrecognized role of Raldh3 in structural and functional development of the vestibular end organs.

  10. Experimental and clinical study of EHF treatment of vascular-vestibular dysfunction

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

    Mal`tsev, A.E.; Abakarov, A.T.; Istomin, V.S.

    1994-07-01

    The authors present the results of a study of the effectiveness of EHF radiation on the cerebral hemodynamics, bioelectrical activity of the cerebral cortex, and functional state of the vestibular analyzer in chronic studies of cats using a model of vascular-vestibular dysfunction. The clinical part of the work reflects the results of studies of the functional state of cerebral blood circulation and the vestibular analyzer during the EHF treatment of angiovertebrogenic vestibular dysfunction in a background of initial manifestations of cerebral blood supply deficiency (angiodistonic variant).

  11. Analysis of vestibular testing in patients with vestibular schwannoma based on the nerve of origin, the localization, and the size of the tumor.

    PubMed

    Suzuki, Mitsuya; Yamada, Chikako; Inoue, Rika; Kashio, Akinori; Saito, Yuki; Nakanishi, Wakako

    2008-10-01

    We aimed to analyze the factors influencing caloric response and vestibular evoked myogenic potential (VEMP) in vestibular schwannoma. The subjects comprised 130 patients with unilateral vestibular schwannoma pathologically diagnosed by surgery. Caloric response and the amplitude and latency of VEMP were measured and analyzed based on the nerve of origin, localization, and size of the tumor. The tumors were classified into 3 types based on localization: intracanalicular, intermediate, and medial; and into 4 grades based on size: 9 mm or less, 10 to 19 mm, 20 to 29 mm, and 30 mm or greater. : Abnormal rates of caloric response and VEMP in patients with tumors arising from the superior vestibular nerve were not significantly different from those in patients with tumors of the inferior vestibular nerve. In the intermediate and medial type-but not in the intracanalicular type-a significant difference in tumor size was observed between patients with normal caloric response and those with canal paresis as also between patients with normal VEMP and those with abnormal VEMP. In patients with tumors that maximally measured 10 to 19 mm or of the intermediate type, the p- and n-wave latencies of VEMP were significantly prolonged compared with those in the normal opposite ear. 1) The nerve of origin of tumors cannot be predicted based on caloric response and VEMP. 2) In the intermediate and medial types, caloric response and the VEMP amplitude are significantly diminished in association with an increase in tumor size. 3) Prolonged VEMP latencies seem to be not only caused by tumor compression to the brainstem or vestibular spinal tract but also by tumor compression isolated to the inferior vestibular nerve.

  12. 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

  13. 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

  14. 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

  15. 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.

  16. Sensory substitution in bilateral vestibular a-reflexic patients

    PubMed Central

    Alberts, Bart B G T; Selen, Luc P J; Verhagen, Wim I M; Medendorp, W Pieter

    2015-01-01

    Patients with bilateral vestibular loss have balance problems in darkness, but maintain spatial orientation rather effectively in the light. It has been suggested that these patients compensate for vestibular cues by relying on extravestibular signals, including visual and somatosensory cues, and integrating them with internal beliefs. How this integration comes about is unknown, but recent literature suggests the healthy brain remaps the various signals into a task-dependent reference frame, thereby weighting them according to their reliability. In this paper, we examined this account in six patients with bilateral vestibular a-reflexia, and compared them to six age-matched healthy controls. Subjects had to report the orientation of their body relative to a reference orientation or the orientation of a flashed luminous line relative to the gravitational vertical, by means of a two-alternative-forced-choice response. We tested both groups psychometrically in upright position (0°) and 90° sideways roll tilt. Perception of body tilt was unbiased in both patients and controls. Response variability, which was larger for 90° tilt, did not differ between groups, indicating that body somatosensory cues have tilt-dependent uncertainty. Perception of the visual vertical was unbiased when upright, but showed systematic undercompensation at 90° tilt. Variability, which was larger for 90° tilt than upright, did not differ between patients and controls. Our results suggest that extravestibular signals substitute for vestibular input in patients’ perception of spatial orientation. This is in line with the current status of rehabilitation programs in acute vestibular patients, targeting at recognizing body somatosensory signals as a reliable replacement for vestibular loss. PMID:25975644

  17. Diversity of vestibular nuclei neurons targeted by cerebellar nodulus inhibition

    PubMed Central

    Meng, Hui; Blázquez, Pablo M; Dickman, J David; Angelaki, Dora E

    2014-01-01

    Abstract A functional role of the cerebellar nodulus and ventral uvula (lobules X and IXc,d of the vermis) for vestibular processing has been strongly suggested by direct reciprocal connections with the vestibular nuclei, as well as direct vestibular afferent inputs as mossy fibres. Here we have explored the types of neurons in the macaque vestibular nuclei targeted by nodulus/ventral uvula inhibition using orthodromic identification from the caudal vermis. We found that all nodulus-target neurons are tuned to vestibular stimuli, and most are insensitive to eye movements. Such non-eye-movement neurons are thought to project to vestibulo-spinal and/or thalamo-cortical pathways. Less than 20% of nodulus-target neurons were sensitive to eye movements, suggesting that the caudal vermis can also directly influence vestibulo-ocular pathways. In general, response properties of nodulus-target neurons were diverse, spanning the whole continuum previously described in the vestibular nuclei. Most nodulus-target cells responded to both rotation and translation stimuli and only a few were selectively tuned to translation motion only. Other neurons were sensitive to net linear acceleration, similar to otolith afferents. These results demonstrate that, unlike the flocculus and ventral paraflocculus which target a particular cell group, nodulus/ventral uvula inhibition targets a large diversity of cell types in the vestibular nuclei, consistent with a broad functional significance contributing to vestibulo-ocular, vestibulo-thalamic and vestibulo-spinal pathways. PMID:24127616

  18. Responses of Caudal Vestibular Nucleus Neurons of Conscious Cats to Rotations in Vertical Planes, Before and After a Bilateral Vestibular Neurectomy

    PubMed Central

    Miller, D. M.; Cotter, L. A.; Gandhi, N. J.; Schor, R. H.; Cass, S. P.; Huff, N. O.; Raj, S. G.; Shulman, J. A; Yates, B. J.

    2008-01-01

    Although many previous experiments have considered the responses of vestibular nucleus neurons to rotations and translations of the head, little data are available regarding cells in the caudalmost portions of the vestibular nuclei (CVN), which mediate vestibulo-autonomic responses among other functions. This study examined the responses of CVN neurons of conscious cats to rotations in vertical planes, both before and after a bilateral vestibular neurectomy. None of the units included in the data sample had eye movement-related activity. In labyrinth-intact animals, some CVN neurons (22%) exhibited graviceptive responses consistent with inputs from otolith organs, but most (55%) had dynamic responses with phases synchronized with stimulus velocity. Furthermore, the large majority of CVN neurons had response vector orientations that were aligned either near the roll or vertical canal planes, and only 18% of cells were preferentially activated by pitch rotations. Sustained head-up rotations of the body provide challenges to the cardiovascular system and breathing, and thus the response dynamics of the large majority of CVN neurons were dissimilar to those of posturally-related autonomic reflexes. These data suggest that vestibular influences on autonomic control mediated by the CVN are more complex than previously envisioned, and likely involve considerable processing and integration of signals by brainstem regions involved in cardiovascular and respiratory regulation. Following a bilateral vestibular neurectomy, CVN neurons regained spontaneous activity within 24 h, and a very few neurons (<10%) responded to vertical tilts <15° in amplitude. These findings indicate that nonlabyrinthine inputs are likely important in sustaining the activity of CVN neurons; thus, these inputs may play a role in functional recovery following peripheral vestibular lesions. PMID:18368395

  19. 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.

  20. 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

  1. Auditory and vestibular dysfunctions in systemic sclerosis: literature review.

    PubMed

    Rabelo, Maysa Bastos; Corona, Ana Paula

    2014-01-01

    To describe the prevalence of auditory and vestibular dysfunction in individuals with systemic sclerosis (SS) and the hypotheses to explain these changes. We performed a systematic review without meta-analysis from PubMed, LILACS, Web of Science, SciELO and SCOPUS databases, using a combination of keywords "systemic sclerosis AND balance OR vestibular" and "systemic sclerosis AND hearing OR auditory." We included articles published in Portuguese, Spanish, or English until December 2011 and reviews, letters, and editorials were excluded. We found 254 articles, out of which 10 were selected. The study design was described, and the characteristics and frequency of the auditory and vestibular dysfunctions in these individuals were listed. Afterwards, we investigated the hypothesis built by the authors to explain the auditory and vestibular dysfunctions in SS. Hearing loss was the most common finding, with prevalence ranging from 20 to 77%, being bilateral sensorineural the most frequent type. It is hypothesized that the hearing impairment in SS is due to vascular changes in the cochlea. The prevalence of vestibular disorders ranged from 11 to 63%, and the most frequent findings were changes in caloric testing, positional nystagmus, impaired oculocephalic response, changes in clinical tests of sensory interaction, and benign paroxysmal positional vertigo. High prevalence of auditory and vestibular dysfunctions in patients with SS was observed. Conducting further research can assist in early identification of these abnormalities, provide resources for professionals who work with these patients, and contribute to improving the quality of life of these individuals.

  2. Significance of Vestibular Testing on Distinguishing the Nerve of Origin for Vestibular Schwannoma and Predicting the Preservation of Hearing

    PubMed Central

    He, Yu-Bo; Yu, Chun-Jiang; Ji, Hong-Ming; Qu, Yan-Ming; Chen, Ning

    2016-01-01

    Background: Determining the nerve of origin for vestibular schwannoma (VS), as a method for predicting hearing prognosis, has not been systematically considered. The vestibular test can be used to investigate the function of the superior vestibular nerve (SVN) and the inferior vestibular nerve (IVN). This study aimed to preoperatively distinguish the nerve of origin for VS patients using the vestibular test, and determine if this correlated with hearing preservation. Methods: A total of 106 patients with unilateral VS were enrolled in this study prospectively. Each patient received a caloric test, vestibular-evoked myogenic potential (VEMP) test, and cochlear nerve function test (hearing) before the operation and 1 week, 3, and 6 months, postoperatively. All patients underwent surgical removal of the VS using the suboccipital approach. During the operation, the nerve of tumor origin (SVN or IVN) was identified by the surgeon. Tumor size was measured by preoperative magnetic resonance imaging. Results: The nerve of tumor origin could not be unequivocally identified in 38 patients (38/106, 35.80%). These patients were not subsequently evaluated. In 26 patients (nine females, seventeen males), tumors arose from the SVN and in 42 patients (18 females, 24 males), tumors arose from the IVN. Comparing with the nerve of origins (SVN and IVN) of tumors, the results of the caloric tests and VEMP tests were significantly different in tumors originating from the SVN and the IVN in our study. Hearing was preserved in 16 of 26 patients (61.54%) with SVN-originating tumors, whereas hearing was preserved in only seven of 42 patients (16.67%) with IVN-originating tumors. Conclusions: Our data suggest that caloric and VEMP tests might help to identify whether VS tumors originate from the SVN or IVN. These tests could also be used to evaluate the residual function of the nerves after surgery. Using this information, we might better predict the preservation of hearing for patients

  3. Effects of high intensity noise on the vestibular system in rats

    PubMed Central

    Stewart, Courtney; Yu, Yue; Huang, Jun; Maklad, Adel; Tang, Xuehui; Allison, Jerome; Mustain, William; Zhou, Wu; Zhu, Hong

    2016-01-01

    Some individuals with noise-induced hearing loss (NIHL) also report balance problems. These accompanying vestibular complaints are not well understood. The present study used a rat model to examine the effects of noise exposure on the vestibular system. Rats were exposed to continuous broadband white noise (0–24kHz) at an intensity of 116dB sound pressure level (SPL) via insert ear phones in one ear for three hours under isoflurane anesthesia. Seven days after the exposure, a significant increase in ABR threshold (43.3±1.9dB) was observed in the noise-exposed ears, indicating hearing loss. Effects of noise exposure on vestibular function were assessed by three approaches. First, fluorescein-conjugated phalloidin staining was used to assess vestibular stereocilia following noise exposure. This analysis revealed substantial sensory stereocilia bundle loss in the saccular and utricular maculae as well as in the anterior and horizontal semicircular canal cristae, but not in the posterior semicircular canal cristae. Second, single unit recording of vestibular afferent activity was performed under pentobarbital anesthesia. A total of 548 afferents were recorded from 10 noise-treated rats and 12 control rats. Noise exposure produced a moderate reduction in baseline firing rates of regular otolith afferents and anterior semicircular canal afferents. Also a moderate change was noted in the gain and phase of the horizontal and anterior semicircular canal afferent’s response to sinusoidal head rotation (1 and 2Hz, 45 degrees/s peak velocity). Third, noise exposure did not result in significant changes in gain or phase of the horizontal rotational and translational vestibular-ocular reflex (VOR). These results suggest that noise exposure not only causes hearing loss, but also causes substantial damage in the peripheral vestibular system in the absence of immediate clinically measurable vestibular signs. These peripheral deficits, however, may lead to vestibular disorders

  4. Role of somatosensory and vestibular cues in attenuating visually induced human postural sway

    NASA Technical Reports Server (NTRS)

    Peterka, Robert J.; Benolken, Martha S.

    1993-01-01

    The purpose was to determine the contribution of visual, vestibular, and somatosensory cues to the maintenance of stance in humans. Postural sway was induced by full field, sinusoidal visual surround rotations about an axis at the level of the ankle joints. The influences of vestibular and somatosensory cues were characterized by comparing postural sway in normal and bilateral vestibular absent subjects in conditions that provided either accurate or inaccurate somatosensory orientation information. In normal subjects, the amplitude of visually induced sway reached a saturation level as stimulus amplitude increased. The saturation amplitude decreased with increasing stimulus frequency. No saturation phenomena was observed in subjects with vestibular loss, implying that vestibular cues were responsible for the saturation phenomenon. For visually induced sways below the saturation level, the stimulus-response curves for both normal and vestibular loss subjects were nearly identical implying that (1) normal subjects were not using vestibular information to attenuate their visually induced sway, possibly because sway was below a vestibular-related threshold level, and (2) vestibular loss subjects did not utilize visual cues to a greater extent than normal subjects; that is, a fundamental change in visual system 'gain' was not used to compensate for a vestibular deficit. An unexpected finding was that the amplitude of body sway induced by visual surround motion could be almost three times greater than the amplitude of the visual stimulus in normals and vestibular loss subjects. This occurred in conditions where somatosensory cues were inaccurate and at low stimulus amplitudes. A control system model of visually induced postural sway was developed to explain this finding. For both subject groups, the amplitude of visually induced sway was smaller by a factor of about four in tests where somatosensory cues provided accurate versus inaccurate orientation information. This

  5. Role of somatosensory and vestibular cues in attenuating visually induced human postural sway

    NASA Technical Reports Server (NTRS)

    Peterka, R. J.; Benolken, M. S.

    1995-01-01

    The purpose of this study was to determine the contribution of visual, vestibular, and somatosensory cues to the maintenance of stance in humans. Postural sway was induced by full-field, sinusoidal visual surround rotations about an axis at the level of the ankle joints. The influences of vestibular and somatosensory cues were characterized by comparing postural sway in normal and bilateral vestibular absent subjects in conditions that provided either accurate or inaccurate somatosensory orientation information. In normal subjects, the amplitude of visually induced sway reached a saturation level as stimulus amplitude increased. The saturation amplitude decreased with increasing stimulus frequency. No saturation phenomena were observed in subjects with vestibular loss, implying that vestibular cues were responsible for the saturation phenomenon. For visually induced sways below the saturation level, the stimulus-response curves for both normal subjects and subjects experiencing vestibular loss were nearly identical, implying (1) that normal subjects were not using vestibular information to attenuate their visually induced sway, possibly because sway was below a vestibular-related threshold level, and (2) that subjects with vestibular loss did not utilize visual cues to a greater extent than normal subjects; that is, a fundamental change in visual system "gain" was not used to compensate for a vestibular deficit. An unexpected finding was that the amplitude of body sway induced by visual surround motion could be almost 3 times greater than the amplitude of the visual stimulus in normal subjects and subjects with vestibular loss. This occurred in conditions where somatosensory cues were inaccurate and at low stimulus amplitudes. A control system model of visually induced postural sway was developed to explain this finding. For both subject groups, the amplitude of visually induced sway was smaller by a factor of about 4 in tests where somatosensory cues provided

  6. Systematic review of vestibular disorders related to human immunodeficiency virus and acquired immunodeficiency syndrome.

    PubMed

    Heinze, B; Swanepoel, D W; Hofmeyr, L M

    2011-09-01

    Disorders of the auditory and vestibular system are often associated with human immunodeficiency virus infection and acquired immunodeficiency syndrome. However, the extent and nature of these vestibular manifestations are unclear. To systematically review the current peer-reviewed literature on vestibular manifestations and pathology related to human immunodeficiency virus and acquired immunodeficiency syndrome. Systematic review of peer-reviewed articles related to vestibular findings in individuals with human immunodeficiency virus infection and acquired immunodeficiency syndrome. Several electronic databases were searched. We identified 442 records, reduced to 210 after excluding duplicates and reviews. These were reviewed for relevance to the scope of the study. We identified only 13 reports investigating vestibular functioning and pathology in individuals affected by human immunodeficiency virus and acquired immunodeficiency syndrome. This condition can affect both the peripheral and central vestibular system, irrespective of age and viral disease stage. Peripheral vestibular involvement may affect up to 50 per cent of patients, and central vestibular involvement may be even more prevalent. Post-mortem studies suggest direct involvement of the entire vestibular system, while opportunistic infections such as oto- and neurosyphilis and encephalitis cause secondary vestibular dysfunction resulting in vertigo, dizziness and imbalance. Patients with human immunodeficiency virus and acquired immunodeficiency syndrome should routinely be monitored for vestibular involvement, to minimise functional limitations of quality of life.

  7. 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.

  8. The Vestibular System and Human Dynamic Space Orientation

    NASA Technical Reports Server (NTRS)

    Meiry, J. L.

    1966-01-01

    The motion sensors of the vestibular system are studied to determine their role in human dynamic space orientation and manual vehicle control. The investigation yielded control models for the sensors, descriptions of the subsystems for eye stabilization, and demonstrations of the effects of motion cues on closed loop manual control. Experiments on the abilities of subjects to perceive a variety of linear motions provided data on the dynamic characteristics of the otoliths, the linear motion sensors. Angular acceleration threshold measurements supplemented knowledge of the semicircular canals, the angular motion sensors. Mathematical models are presented to describe the known control characteristics of the vestibular sensors, relating subjective perception of motion to objective motion of a vehicle. The vestibular system, the neck rotation proprioceptors and the visual system form part of the control system which maintains the eye stationary relative to a target or a reference. The contribution of each of these systems was identified through experiments involving head and body rotations about a vertical axis. Compensatory eye movements in response to neck rotation were demonstrated and their dynamic characteristics described by a lag-lead model. The eye motions attributable to neck rotations and vestibular stimulation obey superposition when both systems are active. Human operator compensatory tracking is investigated in simple vehicle orientation control system with stable and unstable controlled elements. Control of vehicle orientation to a reference is simulated in three modes: visual, motion and combined. Motion cues sensed by the vestibular system through tactile sensation enable the operator to generate more lead compensation than in fixed base simulation with only visual input. The tracking performance of the human in an unstable control system near the limits of controllability is shown to depend heavily upon the rate information provided by the vestibular

  9. 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

  10. Optic flow detection is not influenced by visual-vestibular congruency.

    PubMed

    Holten, Vivian; MacNeilage, Paul R

    2018-01-01

    Optic flow patterns generated by self-motion relative to the stationary environment result in congruent visual-vestibular self-motion signals. Incongruent signals can arise due to object motion, vestibular dysfunction, or artificial stimulation, which are less common. Hence, we are predominantly exposed to congruent rather than incongruent visual-vestibular stimulation. If the brain takes advantage of this probabilistic association, we expect observers to be more sensitive to visual optic flow that is congruent with ongoing vestibular stimulation. We tested this expectation by measuring the motion coherence threshold, which is the percentage of signal versus noise dots, necessary to detect an optic flow pattern. Observers seated on a hexapod motion platform in front of a screen experienced two sequential intervals. One interval contained optic flow with a given motion coherence and the other contained noise dots only. Observers had to indicate which interval contained the optic flow pattern. The motion coherence threshold was measured for detection of laminar and radial optic flow during leftward/rightward and fore/aft linear self-motion, respectively. We observed no dependence of coherence thresholds on vestibular congruency for either radial or laminar optic flow. Prior studies using similar methods reported both decreases and increases in coherence thresholds in response to congruent vestibular stimulation; our results do not confirm either of these prior reports. While methodological differences may explain the diversity of results, another possibility is that motion coherence thresholds are mediated by neural populations that are either not modulated by vestibular stimulation or that are modulated in a manner that does not depend on congruency.

  11. 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.

  12. Vestibular involvement in cognition: Visuospatial ability, attention, executive function, and memory.

    PubMed

    Bigelow, Robin T; Agrawal, Yuri

    2015-01-01

    A growing body of literature suggests the inner ear vestibular system has a substantial impact on cognitive function. The strongest evidence exists in connecting vestibular function to the cognitive domain of visuospatial ability, which includes spatial memory, navigation, mental rotation, and mental representation of three-dimensional space. Substantial evidence also exists suggesting the vestibular system has an impact on attention and cognitive processing ability. The cognitive domains of memory and executive function are also implicated in a number of studies. We will review the current literature, discuss possible causal links between vestibular dysfunction and cognitive performance, and suggest areas of future research.

  13. 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.

  14. Gait ataxia in humans: vestibular and cerebellar control of dynamic stability.

    PubMed

    Schniepp, Roman; Möhwald, Ken; Wuehr, Max

    2017-10-01

    During human locomotion, vestibular feedback control is fundamental for maintaining dynamic stability and adapting the gait pattern to external circumstances. Within the supraspinal locomotor network, the cerebellum represents the key site for the integration of vestibular feedback information. The cerebellum is further important for the fine-tuning and coordination of limb movements during walking. The aim of this review article is to highlight the shared structural and functional sensorimotor principles in vestibular and cerebellar locomotion control. Vestibular feedback for the maintenance of dynamic stability is integrated into the locomotor pattern via midline, caudal cerebellar structures (vermis, flocculonodular lobe). Hemispheric regions of the cerebellum facilitate feed-forward control of multi-joint coordination and higher locomotor functions. Characteristic features of the gait disorder in patients with vestibular deficits or cerebellar ataxia are increased levels of spatiotemporal gait variability in the fore-aft and the medio-lateral gait dimension. In the fore-aft dimension, pathologic increases of gait fluctuations critically depend on the locomotion speed and predominantly manifest during slow walking velocities. This feature is associated with an increased risk of falls in both patients with vestibular hypofunction as well as patients with cerebellar ataxia. Pharmacological approaches for the treatment of vestibular or cerebellar gait ataxia are currently not available. However, new promising options are currently tested in randomized, controlled trials (fampridine/FACEG; acetyl-DL-leucine/ALCAT).

  15. Vestibular rehabilitation: clinical benefits to patients with Parkinson's disease.

    PubMed

    Zeigelboim, Bianca Simone; Klagenberg, Karlin Fabianne; Teive, Hélio A Ghizoni; Munhoz, Renato Puppi; Martins-Bassetto, Jackeline

    2009-06-01

    To evaluate the effectiveness of the vestibular rehabilitation (VR) exercises by means of an assessment before and after the application of the Brazilian version of the Dizziness Handicap Inventory (DHI) questionnaire. Twelve patients were studied, the following procedures were carried out: anamnesis, otorhinolaryngological and vestibular evaluation, and the application of the DHI before and after the VR. Clinically resting tremors and subjective postural instability were the motor complaints most frequently associated with complaints of vertigo in 12 cases (100%); in the vestibular exam, all the patients presented abnormalities, frequently from the uni and bilateral peripheral vestibular deficiency syndromes in 10 cases (83.3%); there was significant improvement in the physical, functional and emotional aspects of the DHI after the completion of the VR. The VR following the Cawthorne and Cooksey protocol were shown to be useful in managing subjective complaints of several aspects evaluated in this protocol.

  16. [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.

  17. Short latency vestibular evoked potentials in the chicken embryo

    NASA Technical Reports Server (NTRS)

    Jones, S. M.; Jones, T. A.

    1996-01-01

    Electrophysiological responses to pulsed linear acceleration stimuli were recorded in chicken embryos incubated for 19 or 20 days (E19/E20). Responses occurred within the first 16 ms following the stimulus onset. The evoked potentials disappeared following bilateral labyrinthectomy, but persisted following cochlear destruction alone, thus demonstrating that the responses were vestibular. Approximately 8 to 10 response peaks could be identified. The first 4 positive and corresponding negative components (early peaks with latencies < 6.0 ms) were scored and latencies and amplitudes quantified. Vestibular response latencies were significantly longer (P < 0.01) and amplitudes significantly smaller (P < 0.001) than those observed in 2-week-old birds. Mean response threshold for anesthetized embryos was -15.9dBre 1.0 g/ms, which was significantly higher (P < 0.03) than those observed in 2-week-old birds (-23.0dBre 1.0 g/ms). Latency/intensity functions (that is, slopes) were not significantly different between embryos and 2-week-old animals, but amplitude/intensity functions for embryos were significantly shallower than those for 2-week-old birds (P < 0.001). We presume that these differences reflect the refinement of sensory function that occurs following 19 to 20 days of incubation. The recording of vestibular evoked potentials provides an objective, direct and noninvasive measure of peripheral vestibular function in the embryo and, as such, the method shows promise as an investigative tool. The results of the present study form the definitive basis for using vestibular evoked potentials in the detailed study of avian vestibular ontogeny and factors that may influence it.

  18. Hair cell specific NTPDase6 immunolocalisation in vestibular end organs: potential role of purinergic signaling in vestibular sensory transduction.

    PubMed

    O'Keeffe, Mary G; Thorne, Peter R; Housley, Gary D; Robson, Simon C; Vlajkovic, Srdjan M

    2012-01-01

    A complex extracellular nucleotide signalling system acting on P2 receptors is involved in regulation of cochlear function in the mammalian inner ear. Ectonucleoside triphosphate diphosphohydrolases (E-NTPDases) are ectonucleotidases that regulate P2 receptor signalling pathways in mammalian tissues by hydrolysing extracellular nucleotides to the respective nucleosides. All enzymes from the CD39/ENTPD family (NTPDase1-8) are expressed in the adult rat cochlea, but their expression and distribution in the vestibular end organ is unknown. This report demonstrates selective expression of NTPDase6 by rat vestibular hair cells. Hair cells transducing both angular acceleration (crista ampullaris) and static head position (maculae of the utricle and saccule) exhibited strong immunolabelling with a bias towards the sensory pole and in particular, the hair cell bundle. NTPDase6 is an intracellular enzyme that can be released in a soluble form from cell cultures and shows an enzymatic preference for nucleoside 5'-diphosphates, such as guanosine 5'-diphosphate (GDP) and uridine 5'-diphosphate (UDP). The main function of NTPDase6 may be the regulation of nucleotide levels in cellular organelles by regulating the conversion of nucleotides to nucleosides. NTPDase6 immunolocalisation in the vestibular end organ could be linked to the regulation of P2 receptor signalling and sensory transduction, including maintenance of vestibular hair bundles.

  19. Exhibition of Stochastic Resonance in Vestibular Perception

    NASA Technical Reports Server (NTRS)

    Galvan-Garza, R. C.; Clark, T. K.; Merfeld, D. M.; Bloomberg, J. J.; Oman, C. M.; Mulavara, A. P.

    2016-01-01

    Astronauts experience sensorimotor changes during spaceflight, particularly during G-transitions. Post flight sensorimotor changes include spatial disorientation, along with postural and gait instability that may degrade operational capabilities of the astronauts and endanger the crew. A sensorimotor countermeasure that mitigates these effects would improve crewmember safety and decrease risk. The goal of this research is to investigate the potential use of stochastic vestibular stimulation (SVS) as a technology to improve sensorimotor function. We hypothesize that low levels of SVS will improve sensorimotor perception through the phenomenon of stochastic resonance (SR), when the response of a nonlinear system to a weak input signal is enhanced by the application of a particular nonzero level of noise. This study aims to advance the development of SVS as a potential countermeasure by 1) demonstrating the exhibition of stochastic resonance in vestibular perception, a vital component of sensorimotor function, 2) investigating the repeatability of SR exhibition, and 3) determining the relative contribution of the semicircular canals (SCC) and otolith (OTO) organs to vestibular perceptual SR. A constant current stimulator was used to deliver bilateral bipolar SVS via electrodes placed on each of the mastoid processes, as previously done. Vestibular perceptual motion recognition thresholds were measured using a 6-degree of freedom MOOG platform and a 150 trial 3-down/1-up staircase procedure. In the first test session, we measured vestibular perceptual thresholds in upright roll-tilt at 0.2 Hz (SCC+OTO) with SVS ranging from 0-700 µA. In a second test session a week later, we re-measured roll-tilt thresholds with 0, optimal (from test session 1), and 1500 µA SVS levels. A subset of these subjects, plus naive subjects, participated in two additional test sessions in which we measured thresholds in supine roll-rotation at 0.2 Hz (SCC) and upright y-translation at 1 Hz

  20. Effects of sleep loss on vestibular response during simple and complex vestibular stimulation.

    DOT National Transportation Integrated Search

    1986-07-01

    Few data are available concerning the effects of sleep loss on vestibular responses although those responses are significant products of motion in aviation environments. This study assessed periodically throughout approx. 55 hrs. of sleep loss the oc...

  1. Monoclonal L-citrulline immunostaining reveals nitric oxide-producing vestibular neurons

    NASA Technical Reports Server (NTRS)

    Holstein, G. R.; Friedrich, V. L. Jr; Martinelli, G. P.

    2001-01-01

    Nitric oxide is an unstable free radical that serves as a novel messenger molecule in the central nervous system (CNS). In order to understand the interplay between classic and novel chemical communication systems in vestibular pathways, the staining obtained using a monoclonal antibody directed against L-citrulline was compared with the labeling observed using more traditional markers for the presence of nitric oxide. Brainstem tissue from adult rats was processed for immunocytochemistry employing a monoclonal antibody directed against L-citrulline, a polyclonal antiserum against neuronal nitric oxide synthase, and/or NADPH-diaphorase histochemistry. Our findings demonstrate that L-citrulline can be fixed in situ by vascular perfusion, and can be visualized in fixed CNS tissue sections by immunocytochemistry. Further, the same vestibular regions and cell types are labeled by NADPH-diaphorase histochemistry, by the neuronal nitric oxide synthase antiserum, and by our anti-L-citrulline antibody. Clusters of L-citrulline-immunoreactive neurons are present in subregions of the vestibular nuclei, including the caudal portion of the inferior vestibular nucleus, the magnocellular portion of the medial vestibular nucleus, and the large cells in the ventral tier of the lateral vestibular nucleus. NADPH-diaphorase histochemical staining of these neurons clearly demonstrated their multipolar, fusiform and globular somata and long varicose dendritic processes. These results provide support for the suggestion that nitric oxide serves key roles in both vestibulo-autonomic and vestibulo-spinal pathways.

  2. 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.

  3. 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.

  4. Vestibular rehabilitation ameliorates chronic dizziness through the SIRT1 axis

    PubMed Central

    Kao, Chung-Lan; Tsai, Kun-Ling; Cheng, Yuan-Yang; Kuo, Chia-Hua; Lee, Shin-Da; Chan, Rai-Chi

    2014-01-01

    Dizziness is a common clinical symptom frequently referred to general neurologists and practitioners. Exercise intervention, in the form of vestibular rehabilitation, is known as an effective clinical management for dizziness. This intervention is reported to have a functional role in correcting dizziness, improving gaze stability, retraining balance and gait, and enhancing physical fitness. Dizziness is known to be highly related to inflammation and oxidative stress. SIRT1 is a major molecule for the regulation of inflammation and mitigation of oxidative stress in chronic diseases such as atherosclerosis and chronic obstructive pulmonary disease. However, the bio-molecular roles of SIRT1 involved in the pathogenesis of dizziness are still largely unclear. In this study, a total of 30 subjects were recruited (15 patients with chronic dizziness, and 15 age/gender matched non-dizzy control subjects). The dizzy subjects group received 18 sessions of 30-min vestibular training. We found that the mRNA and protein expression levels of SIRT1 in the blood samples of chronic dizzy patients were repressed compared with those of healthy controls. After vestibular training, the dizzy patients had significant symptomatic improvements. The SIRT1 expression and its downstream genes (PPAR-γ and PGC-1α) were upregulated after vestibular exercises in dizzy subjects. Notably, the catalytic activity of SIRT1, NADPH and antioxidant enzyme activities were also activated in dizzy patients after vestibular training. Furthermore, vestibular exercise training reduced oxidative events and p53 expression in patients with dizziness. This study demonstrated that vestibular exercise training improved dizziness symptoms, and mechanisms for alleviation of chronic dizziness may partly involve the activation of the SIRT1 axis and the repression of redox status. PMID:24624081

  5. 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.

  6. 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.

  7. Current concepts and future approaches to vestibular rehabilitation.

    PubMed

    Tjernström, Fredrik; Zur, Oz; Jahn, Klaus

    2016-04-01

    Over the last decades methods of vestibular rehabilitation to enhance adaptation to vestibular loss, habituation to changing sensory conditions, and sensory reweighting in the compensation process have been developed. However, the use of these techniques still depends to a large part on the educational background of the therapist. Individualized assessment of deficits and specific therapeutic programs for different disorders are sparse. Currently, vestibular rehabilitation is often used in an unspecific way in dizzy patients irrespective of the clinical findings. When predicting the future of vestibular rehabilitation, it is tempting to foretell advances in technology for assessment and treatment only, but the current intense exchange between clinicians and basic scientists also predicts advances in truly understanding the complex interactions between the peripheral senses and central adaptation mechanisms. More research is needed to develop reliable techniques to measure sensory dependence and to learn how this knowledge can be best used--by playing off the patient's sensory strength or working on the weakness. To be able using the emerging concepts, the neuro-otological community must strive to educate physicians, physiotherapists and nurses to perform the correct examinations for assessment of individual deficits and to look for factors that might impede rehabilitation.

  8. 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

  9. 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.

  10. Prediction of Balance Compensation After Vestibular Schwannoma Surgery.

    PubMed

    Parietti-Winkler, Cécile; Lion, Alexis; Frère, Julien; Perrin, Philippe P; Beurton, Renaud; Gauchard, Gérome C

    2016-06-01

    Background Balance compensation after vestibular schwannoma (VS) surgery is under the influence of specific preoperative patient and tumor characteristics. Objective To prospectively identify potential prognostic factors for balance recovery, we compared the respective influence of these preoperative characteristics on balance compensation after VS surgery. Methods In 50 patients scheduled for VS surgical ablation, we measured postural control before surgery (BS), 8 (AS8) days after, and 90 (AS90) days after surgery. Based on factors found previously in the literature, we evaluated age, body mass index and preoperative physical activity (PA), tumor grade, vestibular status, and preference for visual cues to control balance as potential prognostic factors using stepwise multiple regression models. Results An asymmetric vestibular function was the sole significant explanatory factor for impaired balance performance BS, whereas the preoperative PA alone significantly contributed to higher performance at AS8. An evaluation of patients' balance recovery over time showed that PA and vestibular status were the 2 significant predictive factors for short-term postural compensation (BS to AS8), whereas none of these preoperative factors was significantly predictive for medium-term postoperative postural recovery (AS8 to AS90). Conclusions We identified specific preoperative patient and vestibular function characteristics that may predict postoperative balance recovery after VS surgery. Better preoperative characterization of these factors in each patient could inform more personalized presurgical and postsurgical management, leading to a better, more rapid balance recovery, earlier return to normal daily activities and work, improved quality of life, and reduced medical and societal costs. © The Author(s) 2015.

  11. Sensory convergence in the parieto-insular vestibular cortex

    PubMed Central

    Shinder, Michael E.

    2014-01-01

    Vestibular signals are pervasive throughout the central nervous system, including the cortex, where they likely play different roles than they do in the better studied brainstem. Little is known about the parieto-insular vestibular cortex (PIVC), an area of the cortex with prominent vestibular inputs. Neural activity was recorded in the PIVC of rhesus macaques during combinations of head, body, and visual target rotations. Activity of many PIVC neurons was correlated with the motion of the head in space (vestibular), the twist of the neck (proprioceptive), and the motion of a visual target, but was not associated with eye movement. PIVC neurons responded most commonly to more than one stimulus, and responses to combined movements could often be approximated by a combination of the individual sensitivities to head, neck, and target motion. The pattern of visual, vestibular, and somatic sensitivities on PIVC neurons displayed a continuous range, with some cells strongly responding to one or two of the stimulus modalities while other cells responded to any type of motion equivalently. The PIVC contains multisensory convergence of self-motion cues with external visual object motion information, such that neurons do not represent a specific transformation of any one sensory input. Instead, the PIVC neuron population may define the movement of head, body, and external visual objects in space and relative to one another. This comparison of self and external movement is consistent with insular cortex functions related to monitoring and explains many disparate findings of previous studies. PMID:24671533

  12. Structural and functional connectivity mapping of the vestibular circuitry from human brainstem to cortex.

    PubMed

    Kirsch, V; Keeser, D; Hergenroeder, T; Erat, O; Ertl-Wagner, B; Brandt, T; Dieterich, M

    2016-04-01

    Structural and functional interconnections of the bilateral central vestibular network have not yet been completely delineated. This includes both ipsilateral and contralateral pathways and crossing sites on the way from the vestibular nuclei via the thalamic relay stations to multiple "vestibular cortex" areas. This study investigated "vestibular" connectivity in the living human brain in between the vestibular nuclei and the parieto-insular vestibular cortex (PIVC) by combined structural and functional connectivity mapping using diffusion tensor imaging and functional connectivity magnetic resonance imaging in 24 healthy right-handed volunteers. We observed a congruent functional and structural link between the vestibular nuclei and the ipsilateral and contralateral PIVC. Five separate and distinct vestibular pathways were identified: three run ipsilaterally, while the two others cross either in the pons or the midbrain. Two of the ipsilateral projections run through the posterolateral or paramedian thalamic subnuclei, while the third bypasses the thalamus to reach the inferior part of the insular cortex directly. Both contralateral pathways travel through the posterolateral thalamus. At the cortical level, the PIVC regions of both hemispheres with a right hemispherical dominance are interconnected transcallosally through the antero-caudal splenium. The above-described bilateral vestibular circuitry in its entirety takes the form of a structure of a rope ladder extending from the brainstem to the cortex with three crossings in the brainstem (vestibular nuclei, pons, midbrain), none at thalamic level and a fourth cortical crossing through the splenium of the corpus callosum.

  13. Right-sided dominance of the bilateral vestibular system in the upper brainstem and thalamus.

    PubMed

    Dieterich, Marianne; Kirsch, V; Brandt, T

    2017-10-01

    MRI diffusion tensor imaging tractography was performed on the bilateral vestibular brainstem pathways, which run from the vestibular nuclei via the paramedian and posterolateral thalamic subnuclei to the parieto-insular vestibular cortex. Twenty-one right-handed healthy subjects participated. Quantitative analysis revealed a rope-ladder-like system of vestibular pathways in the brainstem with crossings at pontine and mesencephalic levels. Three structural types of right-left fiber distributions could be delineated: (1) evenly distributed pathways at the lower pontine level from the vestibular nuclei to the pontine crossing, (2) a moderate, pontomesencephalic right-sided lateralization between the pontine and mesencephalic crossings, and (3) a further increase of the right-sided lateralization above the mesencephalic crossing leading to the thalamic vestibular subnuclei. The increasing lateralization along the brainstem was the result of an asymmetric number of pontine and mesencephalic crossing fibers which was higher for left-to-right crossings. The dominance of the right vestibular meso-diencephalic circuitry in right-handers corresponds to the right-hemispheric dominance of the vestibular cortical network. The structural asymmetry apparent in the upper brainstem might be interpreted in relation to the different functions of the vestibular system depending on their anatomical level: a symmetrical sensorimotor reflex control of eye, head, and body mediated by the lower brainstem; a lateralized right-sided upper brainstem-thalamic function as part of the dominant right-sided cortical/subcortical vestibular system that enables a global percept of body motion and orientation in space.

  14. Vestibular stimulation, spatial hemineglect and dysphasia, selective effects.

    PubMed

    Vallar, G; Papagno, C; Rusconi, M L; Bisiach, E

    1995-09-01

    The selectivity of the effects of vestibular stimulation was investigated in a left brain-damaged patient suffering from right visuo-spatial hemineglect and severe dysplasia. Vestibular stimulation temporarily improved the former but not the latter disorder. These results support the view that this treatment improves hemineglect by a specific effect, running counter the rightward distortion of egocentric co-ordinates, rather than by a general hemispheric activation.

  15. Rescue of peripheral vestibular function in Usher syndrome mice using a splice-switching antisense oligonucleotide.

    PubMed

    Vijayakumar, Sarath; Depreux, Frederic F; Jodelka, Francine M; Lentz, Jennifer J; Rigo, Frank; Jones, Timothy A; Hastings, Michelle L

    2017-09-15

    Usher syndrome type 1C (USH1C/harmonin) is associated with profound retinal, auditory and vestibular dysfunction. We have previously reported on an antisense oligonucleotide (ASO-29) that dramatically improves auditory function and balance behavior in mice homozygous for the harmonin mutation Ush1c c.216G > A following a single systemic administration. The findings were suggestive of improved vestibular function; however, no direct vestibular assessment was made. Here, we measured vestibular sensory evoked potentials (VsEPs) to directly assess vestibular function in Usher mice. We report that VsEPs are absent or abnormal in Usher mice, indicating profound loss of vestibular function. Strikingly, Usher mice receiving ASO-29 treatment have normal or elevated vestibular response thresholds when treated during a critical period between postnatal day 1 and 5, respectively. In contrast, treatment of mice with ASO-29 treatment at P15 was minimally effective at rescuing vestibular function. Interestingly, ASO-29 treatment at P1, P5 or P15 resulted in sufficient vestibular recovery to support normal balance behaviors, suggesting a therapeutic benefit to balance with ASO-29 treatment at P15 despite the profound vestibular functional deficits that persist with treatment at this later time. These findings provide the first direct evidence of an effective treatment of peripheral vestibular function in a mouse model of USH1C and reveal the potential for using antisense technology to treat vestibular dysfunction. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. 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.

  17. Visual-vestibular processing deficits in mild traumatic brain injury.

    PubMed

    Wright, W G; Tierney, R T; McDevitt, J

    2017-01-01

    The search for reliable and valid signs and symptoms of mild traumatic brain injury (mTBI), commonly synonymous with concussion, has lead to a growing body of evidence that individuals with long-lasting, unremitting impairments often experience visual and vestibular symptoms, such as dizziness, postural and gait disturbances. Investigate the role of visual-vestibular processing deficits following concussion. A number of clinically accepted vestibular, oculomotor, and balance assessments as well as a novel virtual reality (VR)-based balance assessment device were used to assess adults with post-acute concussion (n = 14) in comparison to a healthy age-matched cohort (n = 58). Significant between-group differences were found with the VR-based balance device (p = 0.001), with dynamic visual motion emerging as the most discriminating balance condition. The symptom reports collected after performing the oculomotor and vestibular tests: rapid alternating horizontal eye saccades, optokinetic stimulation, and gaze stabilization, were all sensitive to health status (p < 0.05), despite the absence of oculomotor abnormalities being observed, except for near-point convergence. The BESS, King-Devick, and Dynamic Visual Acuity tests did not detect between-group differences. Postural and visual-vestibular tasks most closely linked to spatial and self-motion perception had the greatest discriminatory outcomes. The current findings suggest that mesencephalic and parieto-occipital centers and pathways may be involved in concussion.

  18. The Development of the Vestibular Apparatus Under Conditions of Weightlessness

    NASA Technical Reports Server (NTRS)

    Vinnikov, Y. A.; Gazenko, O. G.; Lychakov, D. V.; Palmbakh, L. R.

    1984-01-01

    A series of experiments has been carried out on the effect of space flight conditions on morphogenesis and the structure of the vestibular apparatus in amphibian and fish larvae. Larval development proceeded in weightlessness without serious morphological defects. The vestibular apparatus developed; its organization in the experimental animals did not differ qualitatively from that in the controls. The specific external stimulus (gravitation) appears not to be a necessary condition for the development of a gravitation receptor in ontogenesis although the appearance of the vestibular apparatus in phylogenesis was apparently related to this stimulus.

  19. Fluoxetine for vestibular dysfunction and anxiety: a prospective pilot study.

    PubMed

    Simon, Naomi M; Parker, Stephen W; Wernick-Robinson, Mara; Oppenheimer, Julia E; Hoge, Elizabeth A; Worthington, John J; Korbly, Nicole B; Pollack, Mark H

    2005-01-01

    Anxiety states and disorders amplify the symptoms and impairment associated with vestibular dysfunction. Five patients with inner ear vestibular dysfunction and anxiety were prospectively treated with fluoxetine, 20-60 mg/day, and received an extensive battery of assessments at baseline and after 12 weeks of treatment. Fluoxetine led to significant or near significant reductions in anxiety measures and in impairment due to dizziness; improvements in clinical balance function and vestibular function were less clear. The data add to the literature suggesting a role for selective serotonin reuptake inhibitors in the treatment of dizziness and anxiety.

  20. Effects of droperidol in management of vestibular disorders.

    PubMed

    Johnson, W H; Fenton, R S; Evans, A

    1976-07-01

    The chemo-therapy of vestibular disease has involved a wide spectrum of pharmacological agents insofar as their mode of action is concerned. In our experience, however, droperidol is one pharmaceutical agent which is remarkably effective in depressing vestibular disturbance regardless of etiology. This medication (also called Inapsine) belongs to a relatively new class of compounds known as butyrophenones and its pharmacological action can best be described as a dopa blocking agent. The activity of droperidol on the nervous system first became evident when it was used in combination with the potent analgesic fentanyl citrate in order to produce an anesthetic condition that has been termed neuroleptanalgesia. This mixture (also called Innovar) is rapid in action and results in complete suppression of vestibular activity of both normal subjects and those with Ménière's disease as described by Dowdy, et al., in a preliminary report. These impressive results have prompted us to evaluate the effectiveness of this medication in the treatment of different disorders of the labyrinth. The patients chosen for evaluation were referred for vestibular examination at the Toronto General and St. Michael's Hospitals. Electronystagmography was used to record objectively the effects of the drugs being tested while subjective symptoms including side effects were also noted. These studies involved 20 patients receiving Innovar while 12 patients were tested with Inapsine. Innovar administered in a single dose (droperidol 5 mg, fentanyl 0.1 mg) to patients undergoing acute episodes of vestibular disease (vestibular neuronitis and Ménière's disease) was found effective in the following symptoms and/or signs: nausea, vertigo, nystagmus, the positive past-pointing test and the Romberg test. Innovar appeared to be effective in the amelioration of vomiting although the population was too small to demonstrate statistical significance in this regard. The drug mixture appeared to have no

  1. NAS: The first year

    NASA Technical Reports Server (NTRS)

    Bailey, F. R.; Kutler, Paul

    1988-01-01

    Discussed are the capabilities of NASA's Numerical Aerodynamic Simulation (NAS) Program and its application as an advanced supercomputing system for computational fluid dynamics (CFD) research. First, the paper describes the NAS computational system, called the NAS Processing System Network, and the advanced computational capabilities it offers as a consequence of carrying out the NAS pathfinder objective. Second, it presents examples of pioneering CFD research accomplished during NAS's first operational year. Examples are included which illustrate CFD applications for predicting fluid phenomena, complementing and supplementing experimentation, and aiding in design. Finally, pacing elements and future directions for CFD and NAS are discussed.

  2. 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

  3. 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.

  4. Multisensory Origin of the Subjective First-Person Perspective: Visual, Tactile, and Vestibular Mechanisms

    PubMed Central

    Pfeiffer, Christian; Lopez, Christophe; Schmutz, Valentin; Duenas, Julio Angel; Martuzzi, Roberto; Blanke, Olaf

    2013-01-01

    In three experiments we investigated the effects of visuo-tactile and visuo-vestibular conflict about the direction of gravity on three aspects of bodily self-consciousness: self-identification, self-location, and the experienced direction of the first-person perspective. Robotic visuo-tactile stimulation was administered to 78 participants in three experiments. Additionally, we presented participants with a virtual body as seen from an elevated and downward-directed perspective while they were lying supine and were therefore receiving vestibular and postural cues about an upward-directed perspective. Under these conditions, we studied the effects of different degrees of visuo-vestibular conflict, repeated measurements during illusion induction, and the relationship to a classical measure of visuo-vestibular integration. Extending earlier findings on experimentally induced changes in bodily self-consciousness, we show that self-identification does not depend on the experienced direction of the first-person perspective, whereas self-location does. Changes in bodily self-consciousness depend on visual gravitational signals. Individual differences in the experienced direction of first-person perspective correlated with individual differences in visuo-vestibular integration. Our data reveal important contributions of visuo-vestibular gravitational cues to bodily self-consciousness. In particular we show that the experienced direction of the first-person perspective depends on the integration of visual, vestibular, and tactile signals, as well as on individual differences in idiosyncratic visuo-vestibular strategies. PMID:23630611

  5. Vestibular-somatosensory interactions: effects of passive whole-body rotation on somatosensory detection.

    PubMed

    Ferrè, Elisa Raffaella; Kaliuzhna, Mariia; Herbelin, Bruno; Haggard, Patrick; Blanke, Olaf

    2014-01-01

    Vestibular signals are strongly integrated with information from several other sensory modalities. For example, vestibular stimulation was reported to improve tactile detection. However, this improvement could reflect either a multimodal interaction or an indirect interaction driven by vestibular effects on spatial attention and orienting. Here we investigate whether natural vestibular activation induced by passive whole-body rotation influences tactile detection. In particular, we assessed the ability to detect faint tactile stimuli to the fingertips of the left and right hand during spatially congruent or incongruent rotations. We found that passive whole-body rotations significantly enhanced sensitivity to faint shocks, without affecting response bias. Critically, this enhancement of somatosensory sensitivity did not depend on the spatial congruency between the direction of rotation and the hand stimulated. Thus, our results support a multimodal interaction, likely in brain areas receiving both vestibular and somatosensory signals.

  6. Left hemispheric dominance of vestibular processing indicates lateralization of cortical functions in rats.

    PubMed

    Best, Christoph; Lange, Elena; Buchholz, Hans-Georg; Schreckenberger, Mathias; Reuss, Stefan; Dieterich, Marianne

    2014-11-01

    Lateralization of cortical functions such as speech dominance, handedness and processing of vestibular information are present not only in humans but also in ontogenetic older species, e.g. rats. In human functional imaging studies, the processing of vestibular information was found to be correlated with the hemispherical dominance as determined by the handedness. It is located mainly within the right hemisphere in right handers and within the left hemisphere in left handers. Since dominance of vestibular processing is unknown in animals, our aim was to study the lateralization of cortical processing in a functional imaging study applying small-animal positron emission tomography (microPET) and galvanic vestibular stimulation in an in vivo rat model. The cortical and subcortical network processing vestibular information could be demonstrated and correlated with data from other animal studies. By calculating a lateralization index as well as flipped region of interest analyses, we found that the vestibular processing in rats follows a strong left hemispheric dominance independent from the "handedness" of the animals. These findings support the idea of an early hemispheric specialization of vestibular cortical functions in ontogenetic older species.

  7. Impact of Diabetic Complications on Balance and Falls: Contribution of the Vestibular System

    PubMed Central

    Lin, James; Staecker, Hinrich; Whitney, Susan L.; Kluding, Patricia M.

    2016-01-01

    Diabetes causes many complications, including retinopathy and peripheral neuropathy, which are well understood as contributing to gait instability and falls. A less understood complication of diabetes is the effect on the vestibular system. The vestibular system contributes significantly to balance in static and dynamic conditions by providing spatially orienting information. It is noteworthy that diabetes has been reported to affect vestibular function in both animal and clinical studies. Pathophysiological changes in peripheral and central vestibular structures due to diabetes have been noted. Vestibular dysfunction is associated with impaired balance and a higher risk of falls. As the prevalence of diabetes increases, so does the potential for falls due to diabetic complications. The purpose of this perspective article is to present evidence on the pathophysiology of diabetes-related complications and their influence on balance and falls, with specific attention to emerging evidence of vestibular dysfunction due to diabetes. Understanding this relationship may be useful for screening (by physical therapists) for possible vestibular dysfunction in people with diabetes and for further developing and testing the efficacy of interventions to reduce falls in this population. PMID:26251477

  8. Baseline vestibular and auditory findings in a trial of post-concussive syndrome

    PubMed

    Meehan, Anna; Searing, Elizabeth; Weaver, Lindell; Lewandowski, Andrew

    2016-01-01

    Previous studies have reported high rates of auditory and vestibular-balance deficits immediately following head injury. This study uses a comprehensive battery of assessments to characterize auditory and vestibular function in 71 U.S. military service members with chronic symptoms following mild traumatic brain injury that did not resolve with traditional interventions. The majority of the study population reported hearing loss (70%) and recent vestibular symptoms (83%). Central auditory deficits were most prevalent, with 58% of participants failing the SCAN3:A screening test and 45% showing abnormal responses on auditory steady-state response testing presented at a suprathreshold intensity. Only 17% of the participants had abnormal hearing (⟩25 dB hearing loss) based on the pure-tone average. Objective vestibular testing supported significant deficits in this population, regardless of whether the participant self-reported active symptoms. Composite score on the Sensory Organization Test was lower than expected from normative data (mean 69.6 ±vestibular tests, vestibulo-ocular reflex, central auditory dysfunction, mild traumatic brain injury, post-concussive symptoms, hearing15.6). High abnormality rates were found in funduscopy torsion (58%), oculomotor assessments (49%), ocular and cervical vestibular evoked myogenic potentials (46% and 33%, respectively), and monothermal calorics (40%). It is recommended that a full peripheral and central auditory, oculomotor, and vestibular-balance evaluation be completed on military service members who have sustained head trauma.

  9. Representation of vestibular and visual cues to self-motion in ventral intraparietal (VIP) cortex

    PubMed Central

    Chen, Aihua; Deangelis, Gregory C.; Angelaki, Dora E.

    2011-01-01

    Convergence of vestibular and visual motion information is important for self-motion perception. One cortical area that combines vestibular and optic flow signals is the ventral intraparietal area (VIP). We characterized unisensory and multisensory responses of macaque VIP neurons to translations and rotations in three dimensions. Approximately half of VIP cells show significant directional selectivity in response to optic flow, half show tuning to vestibular stimuli, and one-third show multisensory responses. Visual and vestibular direction preferences of multisensory VIP neurons could be congruent or opposite. When visual and vestibular stimuli were combined, VIP responses could be dominated by either input, unlike medial superior temporal area (MSTd) where optic flow tuning typically dominates or the visual posterior sylvian area (VPS) where vestibular tuning dominates. Optic flow selectivity in VIP was weaker than in MSTd but stronger than in VPS. In contrast, vestibular tuning for translation was strongest in VPS, intermediate in VIP, and weakest in MSTd. To characterize response dynamics, direction-time data were fit with a spatiotemporal model in which temporal responses were modeled as weighted sums of velocity, acceleration, and position components. Vestibular responses in VIP reflected balanced contributions of velocity and acceleration, whereas visual responses were dominated by velocity. Timing of vestibular responses in VIP was significantly faster than in MSTd, whereas timing of optic flow responses did not differ significantly among areas. These findings suggest that VIP may be proximal to MSTd in terms of vestibular processing but hierarchically similar to MSTd in terms of optic flow processing. PMID:21849564

  10. Influences of Vestibular System on Sympathetic Nervous System. Implications for countermeasures.

    NASA Astrophysics Data System (ADS)

    Denise, Pr Pierre

    As gravity is a direct and permanent stress on body fluids, muscles and bones, it is not surpris-ing that weightlessness has important effects on cardiovascular and musculo-skeletal systems. However, these harmful effects do not totally result from the removal of the direct stress of gravity on these organs, but are also partially and indirectly mediated by the vestibular sys-tem. Besides its well known crucial role in spatial orientation and postural equilibrium, it is now clear that the vestibular system is also involved in the regulation of other important physi-ological systems: respiratory and cardiovascular systems, circadian regulation, food intake and even bone mineralization. The neuroanatomical substrate for these vestibular-mediated reg-ulations is still poorly defined, but there is much evidence that vestibular system has strong impacts not only on brainstem autonomic centers but on many hypothalamic nuclei as well. As autonomic nervous system controls almost all body organs, bringing into play the vestibular system by hypergravity or microgravity could virtually affects all major physiological func-tions. There is experimental evidence that weightlessness as well as vestibular lesion induce sympathetic activation thus participating in space related physiological alterations. The fact that some effects of weightlessness on biological systems are mediated by the vestibular system has an important implication for using artificial gravity as a countermeasure: artificial gravity should load not only bones and the cardiovascular system but the vestibular system as well. In short-arm centrifuges, the g load at the head level is low because the head is near the axis of rotation. If the vestibular system is involved in cardiovascular deconditioning and bone loss during weightlessness, it would be more effective to significantly stimulate it and thus it would be necessary to place the head off-axis. Moreover, as the otolithic organs are non longer stimu-lated in

  11. Effect of meprobamate on the vestibulosensory and vestibular somatic reaction

    NASA Technical Reports Server (NTRS)

    Khinchikashvili, N. V.

    1980-01-01

    The influence of meprobamate on the vestibular illusion of counter-rotation, movement coordination and vertical writing was investigated by a double blind trial method and placebo. The results confirm the possibility of the meprobamate application for prophylaxis and correction of vestibular disturbances.

  12. 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.

  13. Kv1 channels and neural processing in vestibular calyx afferents.

    PubMed

    Meredith, Frances L; Kirk, Matthew E; Rennie, Katherine J

    2015-01-01

    Potassium-selective ion channels are important for accurate transmission of signals from auditory and vestibular sensory end organs to their targets in the central nervous system. During different gravity conditions, astronauts experience altered input signals from the peripheral vestibular system resulting in sensorimotor dysfunction. Adaptation to altered sensory input occurs, but it is not explicitly known whether this involves synaptic modifications within the vestibular epithelia. Future investigations of such potential plasticity require a better understanding of the electrophysiological mechanisms underlying the known heterogeneity of afferent discharge under normal conditions. This study advances this understanding by examining the role of the Kv1 potassium channel family in mediating action potentials in specialized vestibular afferent calyx endings in the gerbil crista and utricle. Pharmacological agents selective for different sub-types of Kv1 channels were tested on membrane responses in whole cell recordings in the crista. Kv1 channels sensitive to α-dendrotoxin and dendrotoxin-K were found to prevail in the central regions, whereas K(+) channels sensitive to margatoxin, which blocks Kv1.3 and 1.6 channels, were more prominent in peripheral regions. Margatoxin-sensitive currents showed voltage-dependent inactivation. Dendrotoxin-sensitive currents showed no inactivation and dampened excitability in calyces in central neuroepithelial regions. The differential distribution of Kv1 potassium channels in vestibular afferents supports their importance in accurately relaying gravitational and head movement signals through specialized lines to the central nervous system. Pharmacological modulation of specific groups of K(+) channels could help alleviate vestibular dysfunction on earth and in space.

  14. 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.

  15. Association Between Vestibular Vertigo and Motor Vehicle Accidents: Data From the 2016 National Health Interview Survey.

    PubMed

    Wei, Eric X; Agrawal, Yuri

    2018-05-18

    Recent evidence has shown that individuals with vestibular impairment have higher rates of self-reported driving difficulty compared with individuals without vestibular impairment. However, it is unknown whether individuals with vestibular impairment are more likely to be involved in motor vehicle accidents. We used data from the 2016 National Health Interview Survey of U.S. adults to evaluate whether individuals with vestibular vertigo are more likely to experience motor vehicle accidents relative to individuals without vestibular vertigo. In multivariate analysis, vestibular vertigo was associated with an over threefold increased odds of motor vehicle accidents (odds ratio, 3.5; 95% confidence interval, 1.7-7.3). This study supports an assciation between vestibular dysfunction and driving impairment, and provides a relative risk of motor vehicle accidents associated with vestibular vertigo that clinicians may utilize in counseling patients on the potential safety hazards of driving.

  16. The Effects of Aging on Clinical Vestibular Evaluations

    PubMed Central

    Maheu, Maxime; Houde, Marie-Soleil; Landry, Simon P.; Champoux, François

    2015-01-01

    Balance disorders are common issues for aging populations due to the effects of normal aging on peripheral vestibular structures. These changes affect the results of vestibular function evaluations and make the interpretation of these results more difficult. The objective of this article is to review the current state of knowledge of clinically relevant vestibular measures. We will first focus on otolith function assessment methods cervical-VEMP (cVEMP) and ocular-VEMP (oVEMP), then the caloric and video-head impulse test (vHIT) methods for semicircular canals assessment. cVEMP and oVEMP are useful methods, though research on the effects of age for some parameters are still inconclusive. vHIT results are largely independent of age as compared to caloric stimulation and should therefore be preferred for the evaluation of the semicircular canals function. PMID:26441824

  17. Migraine patients consistently show abnormal vestibular bedside tests.

    PubMed

    Maranhão, Eliana Teixeira; Maranhão-Filho, Péricles; Luiz, Ronir Raggio; Vincent, Maurice Borges

    2016-01-01

    Migraine and vertigo are common disorders, with lifetime prevalences of 16% and 7% respectively, and co-morbidity around 3.2%. Vestibular syndromes and dizziness occur more frequently in migraine patients. We investigated bedside clinical signs indicative of vestibular dysfunction in migraineurs. To test the hypothesis that vestibulo-ocular reflex, vestibulo-spinal reflex and fall risk (FR) responses as measured by 14 bedside tests are abnormal in migraineurs without vertigo, as compared with controls. Cross-sectional study including sixty individuals - thirty migraineurs, 25 women, 19-60 y-o; and 30 gender/age healthy paired controls. Migraineurs showed a tendency to perform worse in almost all tests, albeit only the Romberg tandem test was statistically different from controls. A combination of four abnormal tests better discriminated the two groups (93.3% specificity). Migraine patients consistently showed abnormal vestibular bedside tests when compared with controls.

  18. 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.

  19. Vestibular evoked myogenic potentials in patients with ankylosing spondylitis.

    PubMed

    Özgür, Abdulkadir; Serdaroğlu Beyazal, Münevver; Terzi, Suat; Coşkun, Zerrin Özergin; Dursun, Engin

    2016-10-01

    Ankylosing spondylitis (AS) is a chronic systemic inflammatory disease with unknown etiology. Although sacroiliac joint involvement is the classic sign along with the formed immune mediators, it may result in immune-mediated inner ear disease and may cause damage to the audiovestibular system. Vestibular evoked myogenic potentials (VEMP) is a clinical reflex test used in the diagnosis of vestibular diseases and is performed by recording and evaluating the muscle potentials resulting from the stimulation of the vestibular system with different stimuli. The aim of this study is to evaluate the cervical VEMP test results in AS patients without vestibular symptoms. Thirty-three patients with AS and a control group of 30 healthy volunteers with similar demographic characteristics were evaluated in the study. VEMP wave latency, P13-N23 wave amplitude, and VEMP asymmetry ratio (VAR) values were compared between the groups. The relationship between clinical and laboratory findings of the AS patients and VEMP data were also investigated. Compared with healthy people, this study shows the response rate of patients with ankylosing spondylitis was reduced in the VEMP test, and P13-N23 wave amplitude showed a decrease in AS patients who had VEMP response (p < 0.001). There was no correlation between the clinical and laboratory findings and VEMP findings in patients with ankylosing spondylitis. The data obtained from this study suggest that AS may lead to decreased sensitivity of the vestibular system.

  20. Impaired math achievement in patients with acute vestibular neuritis.

    PubMed

    Moser, Ivan; Vibert, Dominique; Caversaccio, Marco D; Mast, Fred W

    2017-12-01

    Broad cognitive difficulties have been reported in patients with peripheral vestibular deficit, especially in the domain of spatial cognition. Processing and manipulating numbers relies on the ability to use the inherent spatial features of numbers. It is thus conceivable that patients with acute peripheral vestibular deficit show impaired numerical cognition. Using the number Stroop task and a short math achievement test, we tested 20 patients with acute vestibular neuritis and 20 healthy, age-matched controls. On the one hand, patients showed normal congruency and distance effects in the number Stroop task, which is indicative of normal number magnitude processing. On the other hand, patients scored lower than healthy controls in the math achievement test. We provide evidence that the lower performance cannot be explained by either differences in prior math knowledge (i.e., education) or slower processing speed. Our results suggest that peripheral vestibular deficit negatively affects numerical cognition in terms of the efficient manipulation of numbers. We discuss the role of executive functions in math performance and argue that previously reported executive deficits in patients with peripheral vestibular deficit provide a plausible explanation for the lower math achievement scores. In light of the handicapping effects of impaired numerical cognition in daily living, it is crucial to further investigate the mechanisms that cause mathematical deficits in acute PVD and eventually develop adequate means for cognitive interventions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Velocity dependence of vestibular information for postural control on tilting surfaces

    PubMed Central

    Kluzik, JoAnn; Hlavacka, Frantisek

    2016-01-01

    Vestibular information is known to be important for postural stability on tilting surfaces, but the relative importance of vestibular information across a wide range of surface tilt velocities is less clear. We compared how tilt velocity influences postural orientation and stability in nine subjects with bilateral vestibular loss and nine age-matched, control subjects. Subjects stood on a force platform that tilted 6 deg, toes-up at eight velocities (0.25 to 32 deg/s), with and without vision. Results showed that visual information effectively compensated for lack of vestibular information at all tilt velocities. However, with eyes closed, subjects with vestibular loss were most unstable within a critical tilt velocity range of 2 to 8 deg/s. Subjects with vestibular deficiency lost their balance in more than 90% of trials during the 4 deg/s condition, but never fell during slower tilts (0.25–1 deg/s) and fell only very rarely during faster tilts (16–32 deg/s). At the critical velocity range in which falls occurred, the body center of mass stayed aligned with respect to the surface, onset of ankle dorsiflexion was delayed, and there was delayed or absent gastrocnemius inhibition, suggesting that subjects were attempting to actively align their upper bodies with respect to the moving surface instead of to gravity. Vestibular information may be critical for stability at velocities of 2 to 8 deg/s because postural sway above 2 deg/s may be too fast to elicit stabilizing responses through the graviceptive somatosensory system, and postural sway below 8 deg/s may be too slow for somatosensory-triggered responses or passive stabilization from trunk inertia. PMID:27486101

  2. Vision and Vestibular System Dysfunction Predicts Prolonged Concussion Recovery in Children.

    PubMed

    Master, Christina L; Master, Stephen R; Wiebe, Douglas J; Storey, Eileen P; Lockyer, Julia E; Podolak, Olivia E; Grady, Matthew F

    2018-03-01

    Up to one-third of children with concussion have prolonged symptoms lasting beyond 4 weeks. Vision and vestibular dysfunction is common after concussion. It is unknown whether such dysfunction predicts prolonged recovery. We sought to determine which vision or vestibular problems predict prolonged recovery in children. A retrospective cohort of pediatric patients with concussion. A subspecialty pediatric concussion program. Four hundred thirty-two patient records were abstracted. Presence of vision or vestibular dysfunction upon presentation to the subspecialty concussion program. The main outcome of interest was time to clinical recovery, defined by discharge from clinical follow-up, including resolution of acute symptoms, resumption of normal physical and cognitive activity, and normalization of physical examination findings to functional levels. Study subjects were 5 to 18 years (median = 14). A total of 378 of 432 subjects (88%) presented with vision or vestibular problems. A history of motion sickness was associated with vestibular dysfunction. Younger age, public insurance, and presence of headache were associated with later presentation for subspecialty concussion care. Vision and vestibular problems were associated within distinct clusters. Provocable symptoms with vestibulo-ocular reflex (VOR) and smooth pursuits and abnormal balance and accommodative amplitude (AA) predicted prolonged recovery time. Vision and vestibular problems predict prolonged concussion recovery in children. A history of motion sickness may be an important premorbid factor. Public insurance status may represent problems with disparities in access to concussion care. Vision assessments in concussion must include smooth pursuits, saccades, near point of convergence (NPC), and accommodative amplitude (AA). A comprehensive, multidomain assessment is essential to predict prolonged recovery time and enable active intervention with specific school accommodations and targeted rehabilitation.

  3. Diabetes, vestibular dysfunction, and falls: analyses from the National Health and Nutrition Examination Survey.

    PubMed

    Agrawal, Yuri; Carey, John P; Della Santina, Charles C; Schubert, Michael C; Minor, Lloyd B

    2010-12-01

    Patients with diabetes are at increased risk both for falls and for vestibular dysfunction, a known risk factor for falls. Our aims were 1) to further characterize the vestibular dysfunction present in patients with diabetes and 2) to evaluate for an independent effect of vestibular dysfunction on fall risk among patients with diabetes. National cross-sectional survey. Ambulatory examination centers. Adults from the United States aged 40 years and older who participated in the 2001-2004 National Health and Nutrition Examination Survey (n = 5,86). Diagnosis of diabetes, peripheral neuropathy, and retinopathy. Vestibular function measured by the modified Romberg Test of Standing Balance on Firm and Compliant Support Surfaces and history of falling in the previous 12 months. We observed a higher prevalence of vestibular dysfunction in patients with diabetes with longer duration of disease, greater serum hemoglobin A1c levels and other diabetes-related complications, suggestive of a dose-response relationship between diabetes mellitus severity and vestibular dysfunction. We also noted that vestibular dysfunction independently increased the odds of falling more than 2-fold among patients with diabetes (odds ratio, 2.3; 95% confidence interval, 1.1-5.1), even after adjusting for peripheral neuropathy and retinopathy. Moreover, we found that including vestibular dysfunction, peripheral neuropathy, and retinopathy in multivariate models eliminated the significant association between diabetes and fall risk. Vestibular dysfunction may represent a newly recognized diabetes-related complication, which acts as a mediator of the effect of diabetes mellitus on fall risk.

  4. Synaptic plasticity in the medial vestibular nuclei: role of glutamate receptors and retrograde messengers in rat brainstem slices.

    PubMed

    Grassi, S; Pettorossi, V E

    2001-08-01

    The analysis of cellular-molecular events mediating synaptic plasticity within vestibular nuclei is an attempt to explain the mechanisms underlying vestibular plasticity phenomena. The present review is meant to illustrate the main results, obtained in vitro, on the mechanisms underlying long-term changes in synaptic strength within the medial vestibular nuclei. The synaptic plasticity phenomena taking place at the level of vestibular nuclei could be useful for adapting and consolidating the efficacy of vestibular neuron responsiveness to environmental requirements, as during visuo-vestibular recalibration and vestibular compensation. Following a general introduction on the most salient features of vestibular compensation and visuo-vestibular adaptation, which are two plastic events involving neuronal circuitry within the medial vestibular nuclei, the second and third sections describe the results from rat brainstem slice studies, demonstrating the possibility to induce long-term potentiation and depression in the medial vestibular nuclei, following high frequency stimulation of the primary vestibular afferents. In particular the mechanisms sustaining the induction and expression of vestibular long-term potentiation and depression, such as the role of various glutamate receptors and retrograde messengers have been described. The relevant role of the interaction between the platelet-activating factor, acting as a retrograde messenger, and the presynaptic metabotropic glutamate receptors, in determining the full expression of vestibular long-term potentiation is also underlined. In addition, the mechanisms involved in vestibular long-term potentiation have been compared with those leading to long-term potentiation in the hippocampus to emphasize the most significant differences emerging from vestibular studies. The fourth part, describes recent results demonstrating the essential role of nitric oxide, another retrograde messenger, in the induction of vestibular

  5. 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

  6. 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.

  7. 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

  8. Enhancement of Otolith Specific Ocular Responses Using Vestibular Stochastic Resonance

    NASA Technical Reports Server (NTRS)

    Fiedler, Matthew; De Dios, Yiri E.; Esteves, Julie; Galvan, Raquel; Wood, Scott; Bloomberg, Jacob; Mulavara, Ajitkumar

    2011-01-01

    Introduction: Astronauts experience disturbances in sensorimotor function after spaceflight during the initial introduction to a gravitational environment, especially after long-duration missions. Our goal is to develop a countermeasure based on vestibular stochastic resonance (SR) that could improve central interpretation of vestibular input and mitigate these risks. SR is a mechanism by which noise can assist and enhance the response of neural systems to relevant, imperceptible sensory signals. We have previously shown that imperceptible electrical stimulation of the vestibular system enhances balance performance while standing on an unstable surface. Methods: Eye movement data were collected from 10 subjects during variable radius centrifugation (VRC). Subjects performed 11 trials of VRC that provided equivalent tilt stimuli from otolith and other graviceptor input without the normal concordant canal cues. Bipolar stochastic electrical stimulation, in the range of 0-1500 microamperes, was applied to the vestibular system using a constant current stimulator through electrodes placed over the mastoid process behind the ears. In the VRC paradigm, subjects were accelerated to 216 deg./s. After the subjects no longer sensed rotation, the chair oscillated along a track at 0.1 Hz to provide tilt stimuli of 10 deg. Eye movements were recorded for 6 cycles while subjects fixated on a target in darkness. Ocular counter roll (OCR) movement was calculated from the eye movement data during periods of chair oscillations. Results: Preliminary analysis of the data revealed that 9 of 10 subjects showed an average increase of 28% in the magnitude of OCR responses to the equivalent tilt stimuli while experiencing vestibular SR. The signal amplitude at which performance was maximized was in the range of 100-900 microamperes. Discussion: These results indicate that stochastic electrical stimulation of the vestibular system can improve otolith specific responses. This will have a

  9. ELECTROMYOGRAPHIC ACTIVITY OF STERNOCLEIDOMASTOID AND MASTICATORY MUSCLES IN PATIENTS WITH VESTIBULAR LESIONS

    PubMed Central

    Tartaglia, Gianluca M.; Barozzi, Stefania; Marin, Federico; Cesarani, Antonio; Ferrario, Virgilio F.

    2008-01-01

    This study evaluated the electromyographic characteristics of masticatory and neck muscles in subjects with vestibular lesions. Surface electromyography of the masseter, temporalis and sternocleidomastoid muscles was performed in 19 patients with Ménière's disease, 12 patients with an acute peripheral vestibular lesion, and 19 control subjects matched for sex and age. During maximum voluntary clenching, patients with peripheral vestibular lesions had the highest co-contraction of the sternocleidomastoid muscle (analysis of covariance, p=0.02), the control subjects had the smallest values, and the patients with Ménière's disease had intermediate values. The control subjects had larger standardized muscle activities than the other patient groups (p=0.001). In conclusion, during maximum voluntary tooth clenching, patients with vestibular alterations have both more active neck muscles, and less active masticatory muscles than normal controls. Results underline the importance of a more inclusive craniocervical assessment of patients with vestibular lesions. PMID:19082397

  10. Calcitonin gene-related Peptide and choline acetyltransferase colocalization in the human vestibular periphery.

    PubMed

    Popper, Paul; Ishiyama, Akira; Lopez, Ivan; Wackym, Phillip A

    2002-01-01

    Within the vestibular system, calcitonin gene-related peptide (CGRP) has been localized in the efferent terminals and their brainstem neuronal cell bodies in several animal models. Presently, very few studies have verified these findings in the vestibular system in adult primates or humans. CGRP immunoreactivity (CGRPi) and its colocalization with choline acetyltransferase immunoreactivity (ChATi) in human vestibular end organs and Scarpa's ganglion were studied using polyclonal antibodies against CGRP and ChAT, at the light-microscopic level. The CGRPi axons ramified to produce numerous CGRPi terminals throughout the neurosensory epithelium of the maculae and cristae, primarily in the basal and midbasal areas. Numerous CGRPi efferent terminals made contact with both type II vestibular hair cells and the afferent chalices surrounding type I vestibular hair cells. All CGRP immunoreactive fibers also exhibited ChATi. As in the animal models, no CGRPi was found within Scarpa's ganglion. This study provides evidence for CGRPi in the human vestibular periphery and validates the biomedical relevance of the current animal models. Copyright 2002 S. Karger AG, Basel

  11. Adaptations of the vestibular system to short and long-term exposures to altered gravity

    NASA Astrophysics Data System (ADS)

    Bruce, L.

    Long-term space flight creates unique environmental conditions to which the vestibular system must adapt for optimal survival. We are studying two aspects of this vestibular adaptation: (1) How does long-term exposure to microgravity and hypergravity affect the development of vestibular afferents? (2) How does short- term exposure to extremely rapid changes in gravity, such as those that occur during launch and landing, affect the vestibular system. During space flight the gravistatic receptors in the otolith organs are effectively unloaded. In hypergravity conditions they are overloaded. However, the angular acceleration receptors of the semicircular canals receive relatively normal stimulation in both micro- and hypergravity.Rat embryos exposed to microgravity from gestation day 10 (prior to vestibular function) until gestation day 20 (vestibular system is somewhat functional) showed that afferents from the posterior vertical canal projecting to the medial vestibular nucleus developed similarly in microgravity, hypergravity, and in controls . However, afferents from the saccule showed delayed development in microgravity as compared to development in hypergravity and in controls. Cerebellar plasticity is crucial for modification of sensory-motor control and learning. Thus we explored the possibility that strong vestibular stimuli would modify cerebellar motor control (i.e., eye movement, postural control, gut motility) by altering the morphology of cerebellar Purkinje cells. To study the effects of short-term exposures to strong vestibular stimuli we focused on structural changes in the vestibulo-cerebellum that are caused by strong vestibular stimuli. Adult mice were exposed to various combinations of constant and/or rapidly changing angular and linear accelerations for 8.5 min (the time length of shuttle launch). Our data shows that these stimuli cause intense excitation of cerebellar Purkinje cells, inducing up-regulation of clathrin-mediated endocytosis

  12. Adaptation to vestibular disorientation. VIII, "Coriolis" vestibular stimulation and the influence of different visual surrounds.

    DOT National Transportation Integrated Search

    1967-08-01

    Disorientation caused by 'Coriolis' vestibular reactions has been cited frequently as a significant factor in flying safety. In addition, personnel who maintain rotating radar towers may also be adversely affected by 'Coriolis' problems. In the study...

  13. Hypothyroid-associated central vestibular disease in 10 dogs: 1999-2005.

    PubMed

    Higgins, Michael A; Rossmeisl, John H; Panciera, David L

    2006-01-01

    With the exception of myxedema coma, central nervous system signs are rare in hypothyroid dogs. Central vestibular dysfunction is a possible and reversible manifestation of hypothyroidism. Medical records of dogs with vestibular dysfunction and hypothyroidism were reviewed. Of 113 records identified, 10 dogs with at least 2 concurrent clinical neurologic abnormalities localizable to the central vestibular system were included. Retrospective, descriptive study. Median age at diagnosis was 7 years (range, 5-10 years). All dogs were referred for progressive neurologic disease. Lesions were localized to the myelencephalic region in 5 dogs and to the vestibulocerebellum in 5 dogs. Two dogs had evidence of multifocal intracranial disease. Non-neurologic physical abnormalities suggestive of hypothyroidism were absent in 7 of 10 dogs. Hypercholesterolemia was the only consistent clinicopathologic abnormality detected, and was present in 7 of 10 dogs. All dogs had total thyroxine (TT4) and free thyroxine (fT4) concentrations below reference ranges, and 9 of 10 had increased TSH concentrations. Intracranial imaging studies were normal in 5 of 8 dogs, and identified lesions consistent with infarctions in 3 of 8 dogs. Albuminocytologic dissociation was detected in 5 of 6 CSF analyses. Brainstem auditory-evoked responses disclosed prolonged wave V latencies in 3 of 4 dogs tested. No other causes of central vestibular dysfunction were identified during other diagnostic investigations. The median time from initiation of treatment to clinical improvement was 4 days. Vestibular signs resolved in 9 of 10 dogs within 4 weeks. Although the pathogenesis in dogs without evidence of infarction is unknown, central vestibular dysfunction appears to be a rare but reversible neurologic sequelae of hypothyroidism.

  14. Development and Function of the Mouse Vestibular System in the Absence of Gravity Perception

    NASA Technical Reports Server (NTRS)

    Wolgemuth, Debra J.

    2005-01-01

    The hypothesis that was tested in this research was that the absence of gravity perception, such as would occur in space, would affect the development and function of the vestibular and central nervous systems. Further, we postulated that these effects would be more significant at specific stages of post-natal development of the animal. We also proposed the use of molecular genetic approaches that would provide important information as to the hierarchy of gene function during the development and subsequent function of the vestibular system. The tilted (tlt) mutant mouse has been characterized as lacking the ability to provide sensory input to the gravity receptors. The tlt/tlt mutant mice were a particularly attractive model for the study of vestibular function since the primary defect was limited to the receptor part of the vestibular system, and there were no detectable abnormal phenotypes in other organ systems. The goal of the proposed studies was to assess immediate and delayed effects of the lack of gravity perception on the vestibular system. Particular attention was paid to characterizing primarily affected periods of vestibular morphogenesis, and to identifying downstream genetic pathways that are altered in the CNS of the tlt/tlt mutant mouse. The specific aims were: (1) to characterize the postnatal morphogenesis of the CNS in the tlt mutant mouse, using detailed morphometric analysis of isolated vestibular ganglia and brain tissue at different stages of postnatal development and assessment of apoptotic cell death; (2) to examine the expression of selected genes implicated by mutational analysis to be important in vestibular development or function by in situ hybridization or immunohistochemistry in the mutant mice; and (3) to identify other genes involved in vestibular development and function, using differential cloning strategies to isolate genes whose expression is changed in the mutant versus normal vestibular system.

  15. The development of the ICF vestibular environmental scale.

    PubMed

    Whitney, Susan L; Alghadir, Ahmad; Alghwiri, Alia; Alshebber, Kefah M; Alshehri, Mohammed; Furman, Joseph M; Mueller, Martin; Grill, Eva

    2016-07-02

    People with vestibular disorders report changes in symptoms based on their environment with many situations increasing their symptoms. The purpose of this paper was to utilize the International Classification of Functioning Disability and Health (ICF) from the World Health Organization (WHO) to describe common environmental triggers for dizziness in persons living with balance and vestibular disorders. A multi-centre cross-sectional study was conducted with four different centres on three different continents, including patients from the United States (Pittsburgh), Germany (Munich), Jordan (Amman) and Saudi Arabia (Riyadh). Three hundred eighty one persons with vestibular disorders participated. A 9-item questionnaire (the Vestibular Environmental Scale) was developed from existing ICF items, which were compared to Dizziness Handicap Inventory (DHI) scores. Sixty-five percent of participants reported that "quick movements in the vicinity" increased symptoms, "crowds" at 45%, and "design of buildings, e.g. narrow hallways, stairs, elevators" at 42%. The "crowds" item was a good positive predictor of psychogenic vertigo (OR 1.8, 95% Confidence Interval 1.03-3.16), while "food" (OR 0.47, 95% Confidence Interval 0.17-1.29) and "light" (OR 0.41 95% Confidence Interval 0.23-0.75) were negative predictors of psychogenic vertigo. There also was a positive correlation between the number of triggers and DHI score (Spearman correlation coefficient 0.47, p < 0.0001). Sixty-eight percent of the subjects reported an increase in symptoms with between 1 and 4 environmental triggers. In our cross cultural sample, environmental triggers affect dizziness in persons living with balance and vestibular disorders. The use of items from the ICF of the WHO may help to promote cross cultural sharing of information in persons with dizziness.

  16. Brain Activations for Vestibular Stimulation and Dual Tasking Change with Spaceflight

    NASA Technical Reports Server (NTRS)

    Yuan, Peng; Koppelmans, Vincent; Reuter-Lorenz, Patricia; De Dios, Yiri; Gadd, Nichole; Wood, Scott; Riascos, Roy; Kofman, Igor; Bloomberg, Jacob; Mulavara, Ajitkumar; hide

    2017-01-01

    Previous studies have documented the effects of spaceflight on human physiology and behavior, including muscle mass, cardiovascular function, gait, balance, manual motor control, and cognitive performance. An understanding of spaceflight-related changes provides important information about human adaptive plasticity and facilitates future space travel. In the current study, we evaluated how brain activations associated with vestibular stimulation and dual tasking change as a function of spaceflight. Five crewmembers were included in this study. The durations of their spaceflight missions ranged from 3 months to 7 months. All of them completed at least two preflight assessments and at least one postflight assessment. The preflight sessions occurred, on average, about 198 days and 51 days before launch; the first postflight sessions were scheduled 5 days after return. Functional MRI was acquired during vestibular stimulation and dual tasking, at each session. Vestibular stimulation was administered via skull taps delivered by a pneumatic tactile pulse system placed over the lateral cheekbones. The magnitude of brain activations for vestibular stimulation increased with spaceflight relative to the preflight levels, in frontal areas and the precuneus. In addition, longer flight duration was associated with greater preflight-to-postflight increases in vestibular activation in frontal regions. Functional MRI for finger tapping was acquired during both single-task (finger tapping only) and dual-task (simultaneously performing finger tapping and a secondary counting task) conditions. Preflight-to-post-spaceflight decreases in brain activations for dual tasking were observed in the right postcentral cortex. An association between flight duration and amplitude of flight-related change in activations for dual tasking was observed in the parietal cortex. The spaceflight-related increase in vestibular brain activations suggests that after a long-term spaceflight, more neural

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Patients with chronic dizziness following traumatic head injury typically have multiple diagnoses involving combined peripheral and central vestibular dysfunction.

    PubMed

    Arshad, Q; Roberts, R E; Ahmad, H; Lobo, R; Patel, M; Ham, T; Sharp, D J; Seemungal, B M

    2017-04-01

    We hypothesised that chronic vestibular symptoms (CVS) of imbalance and dizziness post-traumatic head injury (THI) may relate to: (i) the occurrence of multiple simultaneous vestibular diagnoses including both peripheral and central vestibular dysfunction in individual patients increasing the chance of missed diagnoses and suboptimal treatment; (ii) an impaired response to vestibular rehabilitation since the central mechanisms that mediate rehabilitation related brain plasticity may themselves be disrupted. We report the results of a retrospective analysis of both the comprehensive clinical and vestibular laboratory testing of 20 consecutive THI patients with prominent and persisting vestibular symptoms still present at least 6months post THI. Individual THI patients typically had multiple vestibular diagnoses and unique to this group of vestibular patients, often displayed both peripheral and central vestibular dysfunction. Despite expert neuro-otological management, at two years 20% of patients still had persisting vestibular symptoms. In summary, chronic vestibular dysfunction in THI could relate to: (i) the presence of multiple vestibular diagnoses, increasing the risk of 'missed' vestibular diagnoses leading to persisting symptoms; (ii) the impact of brain trauma which may impair brain plasticity mediated repair mechanisms. Apart from alerting physicians to the potential for multiple vestibular diagnoses in THI, future work to identify the specific deficits in brain function mediating poor recovery from post-THI vestibular dysfunction could provide the rationale for developing new therapy for head injury patients whose vestibular symptoms are resistant to treatment. Copyright © 2017. Published by Elsevier B.V.

  2. A systems concept of the vestibular organs

    NASA Technical Reports Server (NTRS)

    Mayne, R.

    1974-01-01

    A comprehensive model of vestibular organ function is presented. The model is based on an analogy with the inertial guidance systems used in navigation. Three distinct operations are investigated: angular motion sensing, linear motion sensing, and computation. These operations correspond to the semicircular canals, the otoliths, and central processing respectively. It is especially important for both an inertial guidance system and the vestibular organs to distinguish between attitude with respect to the vertical on the one hand, and linear velocity and displacement on the other. The model is applied to various experimental situations and found to be corroborated by them.

  3. Comparison of virtual reality based therapy with customized vestibular physical therapy for the treatment of vestibular disorders.

    PubMed

    Alahmari, Khalid A; Sparto, Patrick J; Marchetti, Gregory F; Redfern, Mark S; Furman, Joseph M; Whitney, Susan L

    2014-03-01

    We examined outcomes in persons with vestibular disorders after receiving virtual reality based therapy (VRBT) or customized vestibular physical therapy (PT) as an intervention for habituation of dizziness symptoms. Twenty subjects with vestibular disorders received VRBT and 18 received PT. During the VRBT intervention, subjects walked on a treadmill within an immersive virtual grocery store environment, for six sessions approximately one week apart. The PT intervention consisted of gaze stabilization, standing balance and walking exercises individually tailored to each subject. Before, one week after, and at six months after the intervention, subjects completed self-report and balance performance measures. Before and after each VRBT session, subjects also reported symptoms of nausea, headache, dizziness, and visual blurring. In both groups, significant improvements were noted on the majority of self-report and performance measures one week after the intervention. Subjects maintained improvements on self report and performance measures at six months follow up. There were not between group differences. Nausea, headache, dizziness and visual blurring increased significantly during the VRBT sessions, but overall symptoms were reduced at the end of the six-week intervention. While this study did not find a difference in outcomes between PT and VRBT, the mechanism by which subjects with chronic dizziness demonstrated improvement in dizziness and balance function may be different.

  4. 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

  5. Rapid adaptation of multisensory integration in vestibular pathways

    PubMed Central

    Carriot, Jerome; Jamali, Mohsen; Cullen, Kathleen E.

    2015-01-01

    Sensing gravity is vital for our perception of spatial orientation, the control of upright posture, and generation of our everyday activities. When an astronaut transitions to microgravity or returns to earth, the vestibular input arising from self-motion will not match the brain's expectation. Our recent neurophysiological studies have provided insight into how the nervous system rapidly reorganizes when vestibular input becomes unreliable by both (1) updating its internal model of the sensory consequences of motion and (2) up-weighting more reliable extra-vestibular information. These neural strategies, in turn, are linked to improvements in sensorimotor performance (e.g., gaze and postural stability, locomotion, orienting) and perception characterized by similar time courses. We suggest that furthering our understanding of the neural mechanisms that underlie sensorimotor adaptation will have important implications for optimizing training programs for astronauts before and after space exploration missions and for the design of goal-oriented rehabilitation for patients. PMID:25932009

  6. Purchase decision-making is modulated by vestibular stimulation.

    PubMed

    Preuss, Nora; Mast, Fred W; Hasler, Gregor

    2014-01-01

    Purchases are driven by consumers' product preferences and price considerations. Using caloric vestibular stimulation (CVS), we investigated the role of vestibular-affective circuits in purchase decision-making. CVS is an effective noninvasive brain stimulation method, which activates vestibular and overlapping emotional circuits (e.g., the insular cortex and the anterior cingulate cortex (ACC)). Subjects were exposed to CVS and sham stimulation while they performed two purchase decision-making tasks. In Experiment 1 subjects had to decide whether to purchase or not. CVS significantly reduced probability of buying a product. In Experiment 2 subjects had to rate desirability of the products and willingness to pay (WTP) while they were exposed to CVS and sham stimulation. CVS modulated desirability of the products but not WTP. The results suggest that CVS interfered with emotional circuits and thus attenuated the pleasant and rewarding effect of acquisition, which in turn reduced purchase probability. The present findings contribute to the rapidly growing literature on the neural basis of purchase decision-making.

  7. Purchase decision-making is modulated by vestibular stimulation

    PubMed Central

    Preuss, Nora; Mast, Fred W.; Hasler, Gregor

    2014-01-01

    Purchases are driven by consumers’ product preferences and price considerations. Using caloric vestibular stimulation (CVS), we investigated the role of vestibular-affective circuits in purchase decision-making. CVS is an effective noninvasive brain stimulation method, which activates vestibular and overlapping emotional circuits (e.g., the insular cortex and the anterior cingulate cortex (ACC)). Subjects were exposed to CVS and sham stimulation while they performed two purchase decision-making tasks. In Experiment 1 subjects had to decide whether to purchase or not. CVS significantly reduced probability of buying a product. In Experiment 2 subjects had to rate desirability of the products and willingness to pay (WTP) while they were exposed to CVS and sham stimulation. CVS modulated desirability of the products but not WTP. The results suggest that CVS interfered with emotional circuits and thus attenuated the pleasant and rewarding effect of acquisition, which in turn reduced purchase probability. The present findings contribute to the rapidly growing literature on the neural basis of purchase decision-making. PMID:24600365

  8. Motor Performance is Impaired Following Vestibular Stimulation in Ageing Mice.

    PubMed

    Tung, Victoria W K; Burton, Thomas J; Quail, Stephanie L; Mathews, Miranda A; Camp, Aaron J

    2016-01-01

    Balance and maintaining postural equilibrium are important during stationary and dynamic movements to prevent falls, particularly in older adults. While our sense of balance is influenced by vestibular, proprioceptive, and visual information, this study focuses primarily on the vestibular component and its age-related effects on balance. C57Bl/6J mice of ages 1, 5-6, 8-9 and 27-28 months were tested using a combination of standard (such as grip strength and rotarod) and newly-developed behavioral tests (including balance beam and walking trajectory tests with a vestibular stimulus). In the current study, we confirm a decline in fore-limb grip strength and gross motor coordination as age increases. We also show that a vestibular stimulus of low frequency (2-3 Hz) and duration can lead to age-dependent changes in balance beam performance, which was evident by increases in latency to begin walking on the beam as well as the number of times hind-feet slip (FS) from the beam. Furthermore, aged mice (27-28 months) that received continuous access to a running wheel for 4 weeks did not improve when retested. Mice of ages 1, 10, 13 and 27-28 months were also tested for changes in walking trajectory as a result of the vestibular stimulus. While no linear relationship was observed between the changes in trajectory and age, 1-month-old mice were considerably less affected than mice of ages 10, 13 and 27-28 months. this study confirms there are age-related declines in grip strength and gross motor coordination. We also demonstrate age-dependent changes to finer motor abilities as a result of a low frequency and duration vestibular stimulus. These changes showed that while the ability to perform the balance beam task remained intact across all ages tested, behavioral changes in task performance were observed.

  9. Visual and proprioceptive interaction in patients with bilateral vestibular loss.

    PubMed

    Cutfield, Nicholas J; Scott, Gregory; Waldman, Adam D; Sharp, David J; Bronstein, Adolfo M

    2014-01-01

    Following bilateral vestibular loss (BVL) patients gradually adapt to the loss of vestibular input and rely more on other sensory inputs. Here we examine changes in the way proprioceptive and visual inputs interact. We used functional magnetic resonance imaging (fMRI) to investigate visual responses in the context of varying levels of proprioceptive input in 12 BVL subjects and 15 normal controls. A novel metal-free vibrator was developed to allow vibrotactile neck proprioceptive input to be delivered in the MRI system. A high level (100 Hz) and low level (30 Hz) control stimulus was applied over the left splenius capitis; only the high frequency stimulus generates a significant proprioceptive stimulus. The neck stimulus was applied in combination with static and moving (optokinetic) visual stimuli, in a factorial fMRI experimental design. We found that high level neck proprioceptive input had more cortical effect on brain activity in the BVL patients. This included a reduction in visual motion responses during high levels of proprioceptive input and differential activation in the midline cerebellum. In early visual cortical areas, the effect of high proprioceptive input was present for both visual conditions but in lateral visual areas, including V5/MT, the effect was only seen in the context of visual motion stimulation. The finding of a cortical visuo-proprioceptive interaction in BVL patients is consistent with behavioural data indicating that, in BVL patients, neck afferents partly replace vestibular input during the CNS-mediated compensatory process. An fMRI cervico-visual interaction may thus substitute the known visuo-vestibular interaction reported in normal subject fMRI studies. The results provide evidence for a cortical mechanism of adaptation to vestibular failure, in the form of an enhanced proprioceptive influence on visual processing. The results may provide the basis for a cortical mechanism involved in proprioceptive substitution of vestibular

  10. 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.

  11. Multisensory integration in early vestibular processing in mice: the encoding of passive vs. active motion

    PubMed Central

    Medrea, Ioana

    2013-01-01

    The mouse has become an important model system for studying the cellular basis of learning and coding of heading by the vestibular system. Here we recorded from single neurons in the vestibular nuclei to understand how vestibular pathways encode self-motion under natural conditions, during which proprioceptive and motor-related signals as well as vestibular inputs provide feedback about an animal's movement through the world. We recorded neuronal responses in alert behaving mice focusing on a group of neurons, termed vestibular-only cells, that are known to control posture and project to higher-order centers. We found that the majority (70%, n = 21/30) of neurons were bimodal, in that they responded robustly to passive stimulation of proprioceptors as well as passive stimulation of the vestibular system. Additionally, the linear summation of a given neuron's vestibular and neck sensitivities predicted well its responses when both stimuli were applied simultaneously. In contrast, neuronal responses were suppressed when the same motion was actively generated, with the one striking exception that the activity of bimodal neurons similarly and robustly encoded head on body position in all conditions. Our results show that proprioceptive and motor-related signals are combined with vestibular information at the first central stage of vestibular processing in mice. We suggest that these results have important implications for understanding the multisensory integration underlying accurate postural control and the neural representation of directional heading in the head direction cell network of mice. PMID:24089394

  12. 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.

  13. Timing of neuron development in the rodent vestibular system

    NASA Technical Reports Server (NTRS)

    Keefe, J. R.

    1982-01-01

    The timing of cell generation (onset and duration) in the developing rat vestibular and proprioceptive systems is investigated. The results clearly indicate a defined time-span for generation of all neurons in the central nervous system nuclei studied. This cytogenetic period in both vestibular and proprioceptive sensory nuclei is determined to occur during and immediately after placentation, a potentially critical period for spaceflight exposure due to alterations in maternal physiology.

  14. Experiment M131. Human vestibular function

    NASA Technical Reports Server (NTRS)

    Graybiel, A.; Miller, E. F., II; Homick, J. L.

    1977-01-01

    The lower susceptibility to vestibular stimulation aloft, compared with that on ground under experimental conditions, is attributed to a precondition, namely, either there is no need to adapt, or, as exemplified by the Skylab 3 pilot, adaptation to weightlessness is achieved. Findings in some of the astronauts emphasize the distinction between two categories of vestibular side effects: immediate reflex phenomena (illusions, sensations of turning, etc.), and delayed epiphenomena that include the constellation of symptoms and syndromes comprising motion sickness. The drug combinations 1-scopolamine and d-amphetamine and promethazine hydrochloride and ephedrine sulfate are effective in prevention and treatment of motion sickness. It is concluded that prevention of motion sickness in any stressful motion environment involves selection, adaptation, and the use of drugs.

  15. Health‐related quality of life and economic burden of vestibular loss in older adults

    PubMed Central

    Agrawal, Yuri; Semenov, Yevgeniy R.

    2017-01-01

    Objectives Vestibular loss is a debilitating condition, and despite its high prevalence in older adults, the quality of life (QoL) burden of vestibular loss in older individuals has not been well‐studied. This report quantifies the impact on overall QoL and identifies domains of health most affected. We hypothesize vestibular loss will be associated with impairment in diverse domains of health‐related QoL. Study Design Prospective, case‐control study. Methods A convenience sample of 27 patients age ≥60 years with vestibular physiologic loss was recruited from an academic neurotology clinic. The patients did not have any identifiable cause of their vestibular loss other than aging. The convenience sample was compared to an age‐matched cross‐sectional sample of the general US population (n = 1266). The main outcome was QoL measured by the Ontario Health Utilities Index Mark III (HUI3). Results Compared to the general population, patients with vestibular loss had significantly lower overall unadjusted HUI3 scores (−0.32, p < 0.001). Multivariate regression analysis showed vestibular loss was significantly associated with poorer performance in vision (−0.11 p < 0.0001), speech (−0.15, p < 0.0001), dexterity (−0.13, p < 0.0001), and emotion (−0.07, p = 0.0065). Adjusted aggregate HUI3 was also significantly lower for vestibular loss (−0.15, p = 0.0105). These QoL decrements resulted in an average loss of 1.30 Quality‐Adjusted Life Years (QALYs). When using a $50,000/QALY willingness‐to‐pay threshold, vestibular loss was associated with a $64,929 lifetime economic burden per affected older adult, resulting in a total lifetime societal burden of $227 billion for the US population ≥60 years of age. Conclusions Loss of vestibular function with aging significantly decreases quality of life across multiple domains of well‐being. These QoL reductions are responsible for heavy societal economic burdens of vestibular

  16. 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.

  17. Regenerative therapy for vestibular disorders using human induced pluripotent stem cells (iPSCs): neural differentiation of human iPSC-derived neural stem cells after in vitro transplantation into mouse vestibular epithelia.

    PubMed

    Taura, Akiko; Nakashima, Noriyuki; Ohnishi, Hiroe; Nakagawa, Takayuki; Funabiki, Kazuo; Ito, Juichi; Omori, Koichi

    2016-10-01

    Vestibular ganglion cells, which convey sense of motion from vestibular hair cells to the brainstem, are known to degenerate with aging and after vestibular neuritis. Thus, regeneration of vestibular ganglion cells is important to aid in the recovery of balance for associated disorders. The present study derived hNSCs from induced pluripotent stem cells (iPSCs) and transplanted these cells into mouse utricle tissues. After a 7-day co-culture period, histological and electrophysiological examinations of transplanted hNSCs were performed. Injected hNSC-derived cells produced elongated axon-like structures within the utricle tissue that made contact with vestibular hair cells. A proportion of hNSC-derived cells showed spontaneous firing activities, similar to those observed in cultured mouse vestibular ganglion cells. However, hNSC-derived cells around the mouse utricle persisted as immature neurons or occasionally differentiated into putative astrocytes. Moreover, electrophysiological examination showed hNSC-derived cells around utricles did not exhibit any obvious spontaneous firing activities. Injected human neural stem cells (hNSCs) showed signs of morphological maturation including reconnection to denervated hair cells and partial physiological maturation, suggesting hNSC-derived cells possibly differentiated into neurons.

  18. Macaque Parieto-Insular Vestibular Cortex: Responses to self-motion and optic flow

    PubMed Central

    Chen, Aihua; DeAngelis, Gregory C.; Angelaki, Dora E.

    2011-01-01

    The parieto-insular vestibular cortex (PIVC) is thought to contain an important representation of vestibular information. Here we describe responses of macaque PIVC neurons to three-dimensional (3D) vestibular and optic flow stimulation. We found robust vestibular responses to both translational and rotational stimuli in the retroinsular (Ri) and adjacent secondary somatosensory (S2) cortices. PIVC neurons did not respond to optic flow stimulation, and vestibular responses were similar in darkness and during visual fixation. Cells in the upper bank and tip of the lateral sulcus (Ri and S2) responded to sinusoidal vestibular stimuli with modulation at the first harmonic frequency, and were directionally tuned. Cells in the lower bank of the lateral sulcus (mostly Ri) often modulated at the second harmonic frequency, and showed either bimodal spatial tuning or no tuning at all. All directions of 3D motion were represented in PIVC, with direction preferences distributed roughly uniformly for translation, but showing a preference for roll rotation. Spatio-temporal profiles of responses to translation revealed that half of PIVC cells followed the linear velocity profile of the stimulus, one-quarter carried signals related to linear acceleration (in the form of two peaks of direction selectivity separated in time), and a few neurons followed the derivative of linear acceleration (jerk). In contrast, mainly velocity-coding cells were found in response to rotation. Thus, PIVC comprises a large functional region in macaque areas Ri and S2, with robust responses to 3D rotation and translation, but is unlikely to play a significant role in visual/vestibular integration for self-motion perception. PMID:20181599

  19. Functional Imaging of Human Vestibular Cortex Activity Elicited by Skull Tap and Auditory Tone Burst

    NASA Technical Reports Server (NTRS)

    Noohi, F.; Kinnaird, C.; Wood, S.; Bloomberg, J.; Mulavara, A.; Seidler, R.

    2016-01-01

    The current study characterizes brain activation in response to two modes of vestibular stimulation: skull tap and auditory tone burst. The auditory tone burst has been used in previous studies to elicit either the vestibulo-spinal reflex (saccular-mediated colic Vestibular Evoked Myogenic Potentials (cVEMP)), or the ocular muscle response (utricle-mediated ocular VEMP (oVEMP)). Some researchers have reported that air-conducted skull tap elicits both saccular and utricle-mediated VEMPs, while being faster and less irritating for the subjects. However, it is not clear whether the skull tap and auditory tone burst elicit the same pattern of cortical activity. Both forms of stimulation target the otolith response, which provides a measurement of vestibular function independent from semicircular canals. This is of high importance for studying otolith-specific deficits, including gait and balance problems that astronauts experience upon returning to earth. Previous imaging studies have documented activity in the anterior and posterior insula, superior temporal gyrus, inferior parietal lobule, inferior frontal gyrus, and the anterior cingulate cortex in response to different modes of vestibular stimulation. Here we hypothesized that skull taps elicit similar patterns of cortical activity as the auditory tone bursts, and previous vestibular imaging studies. Subjects wore bilateral MR compatible skull tappers and headphones inside the 3T GE scanner, while lying in the supine position, with eyes closed. Subjects received both forms of the stimulation in a counterbalanced fashion. Pneumatically powered skull tappers were placed bilaterally on the cheekbones. The vibration of the cheekbone was transmitted to the vestibular system, resulting in the vestibular cortical response. Auditory tone bursts were also delivered for comparison. To validate our stimulation method, we measured the ocular VEMP outside of the scanner. This measurement showed that both skull tap and auditory

  20. Postural threat influences vestibular-evoked muscular responses.

    PubMed

    Lim, Shannon B; Cleworth, Taylor W; Horslen, Brian C; Blouin, Jean-Sébastien; Inglis, J Timothy; Carpenter, Mark G

    2017-02-01

    Standing balance is significantly influenced by postural threat. While this effect has been well established, the underlying mechanisms of the effect are less understood. The involvement of the vestibular system is under current debate, and recent studies that investigated the effects of height-induced postural threat on vestibular-evoked responses provide conflicting results based on kinetic (Horslen BC, Dakin CJ, Inglis JT, Blouin JS, Carpenter MG. J Physiol 592: 3671-3685, 2014) and kinematic (Osler CJ, Tersteeg MC, Reynolds RF, Loram ID. Eur J Neurosci 38: 3239-3247, 2013) data. We examined the effect of threat of perturbation, a different form of postural threat, on coupling (cross-correlation, coherence, and gain) of the vestibulo-muscular relationship in 25 participants who maintained standing balance. In the "No-Threat" conditions, participants stood quietly on a stable surface. In the "Threat" condition, participants' balance was threatened with unpredictable mediolateral support surface tilts. Quiet standing immediately before the surface tilts was compared to an equivalent time from the No-Threat conditions. Surface EMG was recorded from bilateral trunk, hip, and leg muscles. Hip and leg muscles exhibited significant increases in peak cross-correlation amplitudes, coherence, and gain (1.23-2.66×) in the Threat condition compared with No-Threat conditions, and significant correlations were observed between threat-related changes in physiological arousal and medium-latency peak cross-correlation amplitude in medial gastrocnemius (r = 0.408) muscles. These findings show a clear threat effect on vestibular-evoked responses in muscles in the lower body, with less robust effects of threat on trunk muscles. Combined with previous work, the present results can provide insight into observed changes during balance control in threatening situations. This is the first study to show increases in vestibular-evoked responses of the lower body muscles under conditions

  1. Evidence for vestibular dysfunction in orthostatic hypotension.

    PubMed

    Aoki, Mitsuhiro; Sakaida, Yuzuru; Tanaka, Kunihiko; Mizuta, Keisuke; Ito, Yatsuji

    2012-03-01

    There is little definitive evidence of the clinical significance of the vestibular-cardiovascular reflex in humans, despite the fact that the vestibular system is known to contribute to cardiovascular control in animals. The present study involved 248 dizzy patients (127 male patients and 121 female patients) aged 65 years and younger. We classified all participants into three groups based on their vestibular evoked myogenic potential (VEMP) responses; absent VEMP, asymmetry VEMP and normal VEMP. To investigate the effect of the otolith disorder, which was estimated by the VEMP, on the orthostatic blood pressure responses, the subjects' systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate were monitored during the orthostatic test after they actively stood up. The male patients in the absent VEMP group had a significant drop in their DBP at 1 min after active standing up (P < 0.05) without any change in their SBP. Conversely, male patients in the asymmetry VEMP and normal VEMP groups showed a significant increase in the SBP at 1 min after active standing up (P < 0.05). Female patients in the absent VEMP group did not show any significant drop in their blood pressure after standing up (P > 0.05). In the entire group of participants, a total of 19.6% of the patients in the absent VEMP group fulfilled the criteria for orthostatic hypotension (OH), which was significantly > the 8.6% of patients in the normal VEMP group and the 7.2% in the asymmetry VEMP group (P < 0.05). Our results suggest that vestibular disorders due to the dysfunction of otolith organs provoke OH.

  2. Vertigo in Vestibular Schwannoma Patients Due to Other Pathologies.

    PubMed

    Sahyouni, Ronald; Moshtaghi, Omid; Haidar, Yarah M; Mahboubi, Hossein; Moshtaghi, Afsheen; Lin, Harrison W; Djalilian, Hamid R

    2017-12-01

    To report findings from a cohort of vestibular schwannoma (VS) patients presenting with vertigo from a secondary comorbid vestibular disorder; and to discuss management strategies for this subset of patients presenting with both episodic vertigo and VS. All VS patients who presented with vertigo as the primary symptom from 2012 to 2015 and endorsing no other major complaints were examined. Treatment with migraine lifestyle and prophylactic therapy, or Epley maneuver. Resolution of vertigo following medical treatment alone. Of the nine patients studied, seven (78%) suffered from vestibular migraine, and two (22%) experienced benign positional vertigo. All patients experienced complete resolution of symptoms after treatment. As a result of symptomatic improvement, seven patients (78%) avoided surgery in favor of observation, while two patients (22%) underwent radiosurgery due to continued tumor growth and other nonvertigo symptoms. VS patients can sometimes present with a history of recurrent episodic vertigo. The etiology of the vertigo could be due to the tumor itself or may be due to an underlying comorbidity such as vestibular migraine or benign positional vertigo. VS patients presenting with vertigo should undergo a standard vertigo history and examination to identify other potential causes of vertigo. Most VS patients in our cohort avoided intervention and had resolution of their vertigo.

  3. Vestibular regeneration--experimental models and clinical implications.

    PubMed

    Albu, Silviu; Muresanu, Dafin F

    2012-09-01

    Therapies aimed at the protection and/or regeneration of inner ear hair cells are of great interest, given the significant monetary and quality of life impact of balance disorders. Different viral vectors have been shown to transfect various cell types in the inner ear. The past decade has provided tremendous advances in the use of adenoviral vectors to achieve targeted treatment delivery. Several routes of delivery have been identified to introduce vectors into the inner ear while minimizing injury to surrounding structures. Recently, the transcription factor Atoh1 was determined to play a critical role in hair cell differentiation. Adenoviral-mediated overexpression of Atoh1 in culture and in vivo has demonstrated the ability to regenerate vestibular hair cells by causing transdifferentiation of neighbouring epithelial-supporting cells. Functional recovery of the vestibular system has also been documented following adenoviral-induced Atoh1 overexpression. Experiments demonstrating gene transfer in human vestibular epithelial cells reveal that the human inner ear is a suitable target for gene therapy. © 2012 The Authors Journal of Cellular and Molecular Medicine © 2012 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.

  4. Rotatory and collic vestibular evoked myogenic potential testing in normal-hearing and hearing-impaired children.

    PubMed

    Maes, Leen; De Kegel, Alexandra; Van Waelvelde, Hilde; Dhooge, Ingeborg

    2014-01-01

    Vertigo and imbalance are often underestimated in the pediatric population, due to limited communication abilities, atypical symptoms, and relatively quick adaptation and compensation in children. Moreover, examination and interpretation of vestibular tests are very challenging, because of difficulties with cooperation and maintenance of alertness, and because of the sometimes nauseatic reactions. Therefore, it is of great importance for each vestibular laboratory to implement a child-friendly test protocol with age-appropriate normative data. Because of the often masked appearance of vestibular problems in young children, the vestibular organ should be routinely examined in high-risk pediatric groups, such as children with a hearing impairment. Purposes of the present study were (1) to determine age-appropriate normative data for two child-friendly vestibular laboratory techniques (rotatory and collic vestibular evoked myogenic potential [cVEMP] test) in a group of children without auditory or vestibular complaints, and (2) to examine vestibular function in a group of children presenting with bilateral hearing impairment. Forty-eight typically developing children (mean age 8 years 0 months; range: 4 years 1 month to 12 years 11 months) without any auditory or vestibular complaints as well as 39 children (mean age 7 years 8 months; range: 3 years 8 months to 12 years 10 months) with a bilateral sensorineural hearing loss were included in this study. All children underwent three sinusoidal rotations (0.01, 0.05, and 0.1 Hz at 50 degrees/s) and bilateral cVEMP testing. No significant age differences were found for the rotatory test, whereas a significant increase of N1 latency and a significant threshold decrease was noticeable for the cVEMP, resulting in age-appropriate normative data. Hearing-impaired children demonstrated significantly lower gain values at the 0.01 Hz rotation and a larger percentage of absent cVEMP responses compared with normal-hearing children

  5. Adaptation to vestibular disorientation. X, Modification of vestibular nystagmus and "vertigo" by means of visual stimulation.

    DOT National Transportation Integrated Search

    1968-10-01

    A conflict among sensory signals frequently underlies problems of disorientation, vertigo, and motion sickness. In this study, visual information in conflict with vestibular signals was presented to groups of subjects by illuminating the test room fo...

  6. 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.

  7. Vestibular vertigo and comorbid cognitive and psychiatric impairment: the 2008 National Health Interview Survey.

    PubMed

    Bigelow, Robin T; Semenov, Yevgeniy R; du Lac, Sascha; Hoffman, Howard J; Agrawal, Yuri

    2016-04-01

    Patients with vestibular disease have been observed to have concomitant cognitive and psychiatric dysfunction. We evaluated the association between vestibular vertigo, cognitive impairment and psychiatric conditions in a nationally representative sample of US adults. We performed a cross-sectional analysis using the 2008 National Health Interview Survey (NHIS), which included a Balance and Dizziness Supplement, and questions about cognitive function and psychiatric comorbidity. We evaluated the association between vestibular vertigo, cognitive impairment (memory loss, difficulty concentrating, confusion) and psychiatric diagnoses (depression, anxiety and panic disorder). We observed an 8.4% 1-year prevalence of vestibular vertigo among US adults. In adjusted analyses, individuals with vestibular vertigo had an eightfold increased odds of 'serious difficulty concentrating or remembering' (OR 8.3, 95% CI 4.8 to 14.6) and a fourfold increased odds of activity limitation due to difficulty remembering or confusion (OR 3.9, 95% CI 3.1 to 5.0) relative to the rest of the US adults. Individuals with vestibular vertigo also had a threefold increased odds of depression (OR 3.4, 95% CI 2.9 to 3.9), anxiety (OR 3.2, 95% CI 2.8 to 3.6) and panic disorder (OR 3.4, 95% CI 2.9 to 4.0). Our findings indicate that vestibular impairment is associated with increased risk of cognitive and psychiatric comorbidity. The vestibular system is anatomically connected with widespread regions of the cerebral cortex, hippocampus and amygdala. Loss of vestibular inputs may lead to impairment of these cognitive and affective circuits. Further longitudinal research is required to determine if these associations are causal. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  8. Fifth Symposium on the Role of the Vestibular Organs in Space Exploration

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Vestibular problems of manned space flight are investigated for weightlessness and reduced gravity conditions with emphasis on space station development. Intensive morphological studies on the vestibular system and its central nervous system connections are included.

  9. Vestibular Assessment and Rehabilitation: Ten-Year Survey Trends of Audiologists' Opinions and Practice.

    PubMed

    Nelson, M Dawn; Akin, Faith W; Riska, Kristal M; Andresen, Kimberly; Mondelli, Stephanie Stamps

    2016-02-01

    The past decade has yielded changes in the education and training of audiologists and technological advancements that have become widely available for clinical balance function testing. It is unclear if recent advancements in vestibular instrumentation or the transition to an AuD degree have affected audiologists' vestibular clinical practice or opinions. The purpose of this study was to examine predominant opinions and practices for vestibular assessment (VA) and vestibular rehabilitation (VR) over the past decade and between master's- and AuD-level audiologists. A 31-question survey was administered to audiologists via U.S. mail in 2003 (N = 7,500) and electronically in 2014 (N = 9,984) with a response rate of 12% and 10%, respectively. There was an increase in the number of audiologists providing vestibular services in the past decade. Most respondents agreed that audiologists were the most qualified professionals to conduct VA. Less than half of the surveyed audiologists felt that graduate training was adequate for VA. AuD-level audiologists were more satisfied with graduate training and felt more comfortable performing VA compared to master's-level audiologists. Few respondents agreed that audiologists were the most qualified professionals to conduct VR or that graduate training prepared them to conduct VR. The basic vestibular test battery was unchanged across surveys and included: calorics, smooth pursuit, saccades, search for spontaneous, positional, gaze and optokinetic nystagmus, Dix-Hallpike, case history, and hearing evaluation. There was a trend toward greater use of air (versus water) calorics, videonystagmography (versus electronystagmography), and additional tests of vestibular and balance function. VA is a growing specialty area in the field of audiology. Better training opportunities are needed to increase audiologists' knowledge and skills for providing vestibular services. The basic tests performed during VA have remained relatively unchanged

  10. 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.

  11. 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

  12. Manual control of yaw motion with combined visual and vestibular cues

    NASA Technical Reports Server (NTRS)

    Zacharias, G. L.; Young, L. R.

    1977-01-01

    Measurements are made of manual control performance in the closed-loop task of nulling perceived self-rotation velocity about an earth-vertical axis. Self-velocity estimation was modelled as a function of the simultaneous presentation of vestibular and peripheral visual field motion cues. Based on measured low-frequency operator behavior in three visual field environments, a parallel channel linear model is proposed which has separate visual and vestibular pathways summing in a complementary manner. A correction to the frequency responses is provided by a separate measurement of manual control performance in an analogous visual pursuit nulling task. The resulting dual-input describing function for motion perception dependence on combined cue presentation supports the complementary model, in which vestibular cues dominate sensation at frequencies above 0.05 Hz. The describing function model is extended by the proposal of a non-linear cue conflict model, in which cue weighting depends on the level of agreement between visual and vestibular cues.

  13. Adaptations of the vestibular system to short and long-term exposures to altered gravity

    NASA Astrophysics Data System (ADS)

    Bruce, L. L.

    2003-10-01

    Long-term space flight creates unique environmental conditions to which the vestibular system must adapt for optimal survival of a given organism. The development and maintenance of vestibular connections are controlled by environmental gravitational stimulation as well as genetically controlled molecular interactions. This paper describes the effects of hypergravity on axonal growth and dendritic morphology, respectively. Two aspects of this vestibular adaptation are examined: (1) How does long-term exposure to hypergravity affect the development of vestibular axons? (2) How does short-term exposure to extremely rapid changes in gravity, such as those that occur during shuttle launch and landing, affect dendrites of the vestibulocerebellar system? To study the effects of longterm exposures to altered gravity, embryonic rats that developed in hypergravity were compared to microgravity-exposed and control rats. Examination of the vestibular projections from epithelia devoted to linear and angular acceleration revealed that the terminal fields segregate differently in rat embryos that gestated in each of the gravitational environments.To study the effects of short-term exposures to altered gravity, mice were exposed briefly to strong vestibular stimuli and the vestibulocerebellum was examined for any resulting morphological changes. My data show that these stimuli cause intense vestibular excitation of cerebellar Purkinje cells, which induce up-regulation of clathrin-mediated endocytosis and other morphological changes that are comparable to those seen in long-term depression. This system provides a basis for studying how the vestibular environment can modify cerebellar function, allowing animals to adapt to new environments.

  14. Vestibular-somatosensory convergence in head movement control during locomotion after long-duration space flight.

    PubMed

    Mulavara, A P; Ruttley, T; Cohen, H S; Peters, B T; Miller, C; Brady, R; Merkle, L; Bloomberg, J J

    2012-01-01

    Space flight causes astronauts to be exposed to adaptation in both the vestibular and body load-sensing somatosensory systems. The goal of these studies was to examine the contributions of vestibular and body load-sensing somatosensory influences on vestibular mediated head movement control during locomotion after long-duration space flight. Subjects walked on a motor driven treadmill while performing a gaze stabilization task. Data were collected from three independent subject groups that included bilateral labyrinthine deficient (LD) patients, normal subjects before and after 30 minutes of 40% bodyweight unloaded treadmill walking, and astronauts before and after long-duration space flight. Motion data from the head and trunk segments were used to calculate the amplitude of angular head pitch and trunk vertical translation movement while subjects performed a gaze stabilization task, to estimate the contributions of vestibular reflexive mechanisms in head pitch movements. Exposure to unloaded locomotion caused a significant increase in head pitch movements in normal subjects, whereas the head pitch movements of LD patients were significantly decreased. This is the first evidence of adaptation of vestibular mediated head movement responses to unloaded treadmill walking. Astronaut subjects showed a heterogeneous response of both increases and decreases in the amplitude of head pitch movement. We infer that body load-sensing somatosensory input centrally modulates vestibular input and can adaptively modify vestibularly mediated head-movement control during locomotion. Thus, space flight may cause central adaptation of the converging vestibular and body load-sensing somatosensory systems leading to alterations in head movement control.

  15. Role of cerebellar nodulus and uvula on the vestibular quick phase spatial constancy.

    PubMed

    Pettorossi, V E; Grassi, S; Errico, P; Barmack, N H

    2001-01-01

    We investigated the orientation of quick phases (QPs) of vestibularly-induced eye movements in rabbits in response to "off-vertical" sinusoidal vestibular stimulation. We also examined the possible role of the cerebellar nodulus and ventral uvula in controlling QP spatial orientation and modification. During "off-vertical" vestibular stimulation QPs remained aligned with the earth's horizontal plane, while the slow phases (SPs) were aligned with the plane of vestibular stimulation. This suggests that QPs are coded in gravito-inertial coordinates and SPs in head coordinates. When rabbits were oscillated in the light (20 degrees peak-to-peak; 0.2 Hz) about an "off-vertical" axis for 2 h, the QPs changed their trajectory, abandoning the earth's horizontal plane to approach the plane of the stimulus. By contrast, in the absence of conjunctive optokinetic stimulation, QPs remained fixed in the earth's horizontal plane even after 2 h of "off-vertical" stimulation. The conjunctive combination of optokinetic and vestibular stimulation caused QPs to change their plane of rotation. After lesion of the nodulus-uvula the ability of rabbits to reorient QPs during conjoint vestibular-optokinetic stimulation was maintained. We conclude that the space orientation and adaptation of QPs do not require cerebellar control.

  16. 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

  17. Bilateral Vestibular Dysfunction Associated With Chronic Exposure to Military Jet Propellant Type-Eight Jet Fuel

    PubMed Central

    Fife, Terry D.; Robb, Michael J. A.; Steenerson, Kristen K.; Saha, Kamala C.

    2018-01-01

    We describe three patients diagnosed with bilateral vestibular dysfunction associated with the jet propellant type-eight (JP-8) fuel exposure. Chronic exposure to aromatic and aliphatic hydrocarbons, which are the main constituents of JP-8 military aircraft jet fuel, occurred over 3–5 years’ duration while working on or near the flight line. Exposure to toxic hydrocarbons was substantiated by the presence of JP-8 metabolite n-hexane in the blood of one of the cases. The presenting symptoms were dizziness, headache, fatigue, and imbalance. Rotational chair testing confirmed bilateral vestibular dysfunction in all the three patients. Vestibular function improved over time once the exposure was removed. Bilateral vestibular dysfunction has been associated with hydrocarbon exposure in humans, but only recently has emphasis been placed specifically on the detrimental effects of JP-8 jet fuel and its numerous hydrocarbon constituents. Data are limited on the mechanism of JP-8-induced vestibular dysfunction or ototoxicity. Early recognition of JP-8 toxicity risk, cessation of exposure, and customized vestibular therapy offer the best chance for improved balance. Bilateral vestibular impairment is under-recognized in those chronically exposed to all forms of jet fuel. PMID:29867750

  18. Bilateral Vestibular Dysfunction Associated With Chronic Exposure to Military Jet Propellant Type-Eight Jet Fuel.

    PubMed

    Fife, Terry D; Robb, Michael J A; Steenerson, Kristen K; Saha, Kamala C

    2018-01-01

    We describe three patients diagnosed with bilateral vestibular dysfunction associated with the jet propellant type-eight (JP-8) fuel exposure. Chronic exposure to aromatic and aliphatic hydrocarbons, which are the main constituents of JP-8 military aircraft jet fuel, occurred over 3-5 years' duration while working on or near the flight line. Exposure to toxic hydrocarbons was substantiated by the presence of JP-8 metabolite n -hexane in the blood of one of the cases. The presenting symptoms were dizziness, headache, fatigue, and imbalance. Rotational chair testing confirmed bilateral vestibular dysfunction in all the three patients. Vestibular function improved over time once the exposure was removed. Bilateral vestibular dysfunction has been associated with hydrocarbon exposure in humans, but only recently has emphasis been placed specifically on the detrimental effects of JP-8 jet fuel and its numerous hydrocarbon constituents. Data are limited on the mechanism of JP-8-induced vestibular dysfunction or ototoxicity. Early recognition of JP-8 toxicity risk, cessation of exposure, and customized vestibular therapy offer the best chance for improved balance. Bilateral vestibular impairment is under-recognized in those chronically exposed to all forms of jet fuel.

  19. Comparison of Virtual Reality Based Therapy with Customized Vestibular Physical Therapy for the Treatment of Vestibular Disorders

    PubMed Central

    Alahmari, Khalid A.; Sparto, Patrick J; Marchetti, Gregory F.; Redfern, Mark S.; Furman, Joseph M.; Whitney, Susan L.

    2017-01-01

    We examined outcomes in persons with vestibular disorders after receiving virtual reality based therapy (VRBT) or customized vestibular physical therapy (PT) as an intervention for habituation of dizziness symptoms. Twenty subjects with vestibular disorders received VRBT and 18 received PT. During the VRBT intervention, subjects walked on a treadmill within an immersive virtual grocery store environment, for 6 sessions approximately one week apart. The PT intervention consisted of gaze stabilization, standing balance and walking exercises individually tailored to each subject. Before, one week after, and at 6-months after the intervention, subjects completed self-report and balance performance measures. Before and after each VRBT session, subjects also reported symptoms of nausea, headache, dizziness, and visual blurring. In both groups, significant improvements were noted on the majority of self-report and performance measures one week after the intervention. Subjects maintained improvements on self report and performance measures at 6 months follow up. There were not between group differences. Nausea, headache, dizziness and visual blurring increased significantly during the VRBT sessions, but overall symptoms were reduced at the end of the six-week intervention. While this study did not find a difference in outcomes between PT and VRBT, the mechanism by which subjects with chronic dizziness demonstrated improvement in dizziness and balance function may be different. PMID:24608691

  20. Peripheral generators of the vestibular evoked potentials (VsEPs) in the chick.

    PubMed

    Weisleder, P; Jones, T A; Rubel, E W

    1990-10-01

    Electrophysiological activity in response to linear acceleration stimuli was recorded from young chickens by means of subcutaneous electrodes. This investigation had 2 purposes: (1) to establish the vestibular origin of the potentials; and (2) to investigate the contribution of each vestibular labyrinth to the response. The stimuli consisted of pulses of linear acceleration delivered by a mechanical vibrator (shaker). In the first set of experiments vestibular evoked potentials (VsEPs) were recorded prior to and 24 h after bilateral cochlea removal. In the second set of experiments responses were recorded before and after unilateral or bilateral intralabyrinthine injections of tetrodotoxin (TTX). Different groups of subjects were used for each experimental condition. The general morphology of the VsEPs was maintained after bilateral cochlea removal. Absolute latency of wave P2, the most prominent component of the response, was not significantly affected by the manipulation. Unilateral intralabyrinthine TTX injections consistently prolonged the latency and reduced the amplitude of wave P2. Following binaural TTX injections we were unable to elicit responses at the acceleration levels used in this study. The results from these experiments suggest that: (1) the activity recorded in response to linear acceleration stimuli is vestibular in origin; (2) when recorded from intact animals the evoked response is composed of activity from both vestibular systems; and (3) TTX consistently blocks the activity of the vestibular portion of the VIIIth cranial nerve.

  1. Vestibular sensory functional status of cochlear implanted ears versus non-implanted ears in bilateral profound deaf adults.

    PubMed

    Cozma, Romică Sebastian; Dima-Cozma, Lucia Corina; Rădulescu, Luminiţa Mihaela; Hera, Maria Cristina; Mârţu, Cristian; Olariu, Raluca; Cobzeanu, Bogdan Mihail; Bitere, Oana Roxana; Cobzeanu, Mihail Dan

    2018-01-01

    Patients with hearing loss who underwent cochlear implantation can present symptomatic or asymptomatic vestibular damages earlier or later after the surgery. The vestibular permanent lesions could be acute, produced by surgical trauma or could be progressive due to local morphological changes made by the presence of the portelectrode in the inner ear (fibrosis related, ossification, basilar membrane distortion, endolymphatic hydrops). Besides histopathological findings in inner ear of cochlear implanted patients, the vestibular permanent damages could be found by assessment of clinical vestibular status. This study reports the sensorial vestibular functional findings for adults in cochlear implanted ears related to the electrode insertion type (cochleostomy or round window approach) and comparing to non-implanted deaf ears. A total of 20 adult patients with 32 cochlear implanted ears (12 patients with binaural cochlear implant and eight with monoaural) were selected for postoperatory vestibular examination by cervical and ocular vestibular myogenic potentials and vestibular caloric tests. The same tests were made for a control group of 22 non-implanted deaf ears. Functional testing results were reported related to the electrode insertion approach. For the cochleostomy group, we found different deficits: in 40% for saccular function, 44% for utricular function, and 12% horizontal canal dysfunction. In round window group, the deficit was present in 14.29% for saccular function, 28.57% for utricular function, and 28.58% for horizontal canal. In 46.88% of implanted ears, the vestibular function was completely preserved on all tested sensors. In conclusion, the vestibular functional status after inner ear surgery presents sensorial damages in 53.12% ears compare with the vestibular dysfunction existing in 50% of deaf non-operated ears. Round window insertion allows for better conservation of the vestibular function.

  2. Evaluating Inhibition of Motoneuron Firing From Electromyogram Data to Assess Vestibular Output Using Vestibular Evoked Myogenic Potentials.

    PubMed

    Prakash, S R; Herrmann, Barbara S; Milojcic, Rupprecht; Rauch, Steven D; Guinan, John J

    2015-01-01

    Vestibular evoked myogenic potentials (VEMPs) are due to vestibular responses producing brief inhibitions of muscle contractions that are detectable in electromyographic (EMG) responses. VEMP amplitudes are traditionally measured by the peak to peak amplitude of the averaged EMG response (VEMPpp) or by a normalized VEMPpp (nVEMPpp). However, a brief EMG inhibition does not satisfy the statistical assumptions for the average to be the optimal processing strategy. Here, it is postulated that the inhibition depth of motoneuron firing is the desired metric for showing the influence of the vestibular system on the muscle system. The authors present a metric called "VEMPid" that estimates this inhibition depth from the EMG data obtained in a usual VEMP data acquisition. The goal of this article was to compare how well VEMPid, VEMPpp, and nVEMPpp track inhibition depth. To find a robust method to compare VEMPid, VEMPpp, and nVEMPpp, realistic physiological models for the inhibition of VEMP EMG signals were made using VEMP data from four measurement sessions on each of the five normal subjects. Each of the resulting 20 EMG-production models was adjusted to match the EMG autocorrelation of an individual subject and session. Simulated VEMP traces produced by these models were used to compare how well VEMPid, VEMPpp, and nVEMPpp tracked model inhibition depth. Applied to simulated and real VEMP data, VEMPid showed good test-retest consistency and greater sensitivity at low stimulus levels than VEMPpp or nVEMPpp. For large-amplitude responses, nVEMPpp and VEMPid were equivalent in their consistency across subjects and sessions, but for low-amplitude responses, VEMPid was superior. Unnormalized VEMPpp was always worse than nVEMPpp or VEMPid. VEMPid provides a more reliable measurement of vestibular function at low sound levels than the traditional nVEMPpp, without requiring a change in how VEMP tests are performed. The calculation method for VEMPid should be applicable whenever

  3. Effects of microgravity on vestibular ontogeny: direct physiological and anatomical measurements following space flight (STS-29)

    NASA Technical Reports Server (NTRS)

    Jones, T. A.; Fermin, C.; Hester, P. Y.; Vellinger, J.

    1993-01-01

    Does space flight change gravity receptor development? The present study measured vestibular form and function in birds flown as embryos for 5 days in earth orbit (STS-29). No major changes in vestibular gross morphology were found. Vestibular response mean amplitudes and latencies were unaffected by space flight. However, the results of measuring vestibular thresholds were mixed and abnormal responses in 3 of the 8 flight animals raise important questions.

  4. The Development of Vestibular Connections in Rat Embryos in Microgravity

    NASA Technical Reports Server (NTRS)

    Bruce, Laura L.; Fritzsch, Bernd

    1997-01-01

    Existing experimental embryological data suggests that the vestibular system initially develops in a very rigid and genetically controlled manner. Nevertheless, gravity appears to be a critical factor in the normal development of the vestibular system that monitors position with respect to gravity (saccule and utricle). In fact several studies have shown that prenatal exposure to microgravity causes temporary deficits in gravity-dependent righting behaviors, and prolonged exposure to hypergravity from conception to weaning causes permanent deficits in gravity-dependent righting behaviors. Data on hypergravity and microgravity exposure suggest some changes in the otolith formation during development, in particular the size although these changes may actually vary with the species involved. In adults exposed to microgravity there is a change in the synaptic density in the otic sensory epithelia suggesting that some adaptation may occur there. However, effects have also been reported in the brainstem. Several studies have shown synaptic changes in the lateral vestibular nucleus and in the nodulus of the cerebellum after neonatal exposure to hypergravity. We report here that synaptogenesis in the medial vestibular nucleus is retarded in developing rat embryos that were exposed to microgravity from gestation days 9 to 19.

  5. Visual gravitational motion and the vestibular system in humans

    PubMed Central

    Lacquaniti, Francesco; Bosco, Gianfranco; Indovina, Iole; La Scaleia, Barbara; Maffei, Vincenzo; Moscatelli, Alessandro; Zago, Myrka

    2013-01-01

    The visual system is poorly sensitive to arbitrary accelerations, but accurately detects the effects of gravity on a target motion. Here we review behavioral and neuroimaging data about the neural mechanisms for dealing with object motion and egomotion under gravity. The results from several experiments show that the visual estimates of a target motion under gravity depend on the combination of a prior of gravity effects with on-line visual signals on target position and velocity. These estimates are affected by vestibular inputs, and are encoded in a visual-vestibular network whose core regions lie within or around the Sylvian fissure, and are represented by the posterior insula/retroinsula/temporo-parietal junction. This network responds both to target motions coherent with gravity and to vestibular caloric stimulation in human fMRI studies. Transient inactivation of the temporo-parietal junction selectively disrupts the interception of targets accelerated by gravity. PMID:24421761

  6. Visual gravitational motion and the vestibular system in humans.

    PubMed

    Lacquaniti, Francesco; Bosco, Gianfranco; Indovina, Iole; La Scaleia, Barbara; Maffei, Vincenzo; Moscatelli, Alessandro; Zago, Myrka

    2013-12-26

    The visual system is poorly sensitive to arbitrary accelerations, but accurately detects the effects of gravity on a target motion. Here we review behavioral and neuroimaging data about the neural mechanisms for dealing with object motion and egomotion under gravity. The results from several experiments show that the visual estimates of a target motion under gravity depend on the combination of a prior of gravity effects with on-line visual signals on target position and velocity. These estimates are affected by vestibular inputs, and are encoded in a visual-vestibular network whose core regions lie within or around the Sylvian fissure, and are represented by the posterior insula/retroinsula/temporo-parietal junction. This network responds both to target motions coherent with gravity and to vestibular caloric stimulation in human fMRI studies. Transient inactivation of the temporo-parietal junction selectively disrupts the interception of targets accelerated by gravity.

  7. A brief review of the clinical anatomy of the vestibular-ocular connections-how much do we know?

    PubMed

    Bronstein, A M; Patel, M; Arshad, Q

    2015-02-01

    The basic connectivity from the vestibular labyrinth to the eye muscles (vestibular ocular reflex, VOR) has been elucidated in the past decade, and we summarise this in graphic format. We also review the concept of 'velocity storage', a brainstem integrator that prolongs vestibular responses. Finally, we present new discoveries of how complex visual stimuli, such as binocular rivalry, influence VOR processing. In contrast to the basic brainstem circuits, cortical vestibular circuits are far from being understood, but parietal-vestibular nuclei projections are likely to be involved.

  8. Long-term mobile phone use and the risk of vestibular schwannoma: a Danish nationwide cohort study.

    PubMed

    Schüz, Joachim; Steding-Jessen, Marianne; Hansen, Søren; Stangerup, Sven-Eric; Cayé-Thomasen, Per; Poulsen, Aslak Harbo; Olsen, Jørgen H; Johansen, Christoffer

    2011-08-15

    Vestibular schwannomas grow in the region within the brain where most of the energy by radiofrequency electromagnetic fields from using mobile phones is absorbed. The authors used 2 Danish nationwide cohort studies, one a study of all adult Danes subscribing for a mobile phone in 1995 or earlier and one on sociodemographic factors and cancer risk, and followed subjects included in both cohorts for occurrence of vestibular schwannoma up to 2006 inclusively. In this study including 2.9 million subjects, a long-term mobile phone subscription of ≥11 years was not related to an increased vestibular schwannoma risk in men (relative risk estimate = 0.87, 95% confidence interval: 0.52, 1.46), and no vestibular schwannoma cases among long-term subscribers occurred in women versus 1.6 expected. Vestibular schwannomas did not occur more often on the right side of the head, although the majority of Danes reported holding their mobile phone to the right ear. Vestibular schwannomas in long-term male subscribers were not of larger size than expected. Overall, no evidence was found that mobile phone use is related to the risk of vestibular schwannoma. Because of the usually slow growth of vestibular schwannoma and possible diagnostic delay, further surveillance is indicated.

  9. Maternal susceptibility to nausea and vomiting of pregnancy: is the vestibular system involved?

    NASA Technical Reports Server (NTRS)

    Black, F. Owen

    2002-01-01

    Nausea and vomiting of pregnancy shares many characteristics with motion sickness, a vestibular dependent phenomenon. A number of physiologic changes that occur in normal pregnancy are also known to accompany nausea and vomiting in patients with motion sickness and certain vestibular disorders. This chapter summarizes some shared features of both phenomena. The unmasking of subclinical vestibular disorders may account for some cases of hyperemesis gravidarum. Hormonal effects on neurotransmitter function may also play a role in nausea and vomiting of pregnancy and in some vestibular disorders; however, the specific neural mechanisms of nausea and vomiting have not been identified. Until the neurochemical processes underlying these phenomena are understood, prevention and management will remain in the domain of astute, but so far limited, clinical observation.

  10. Who is at risk for ongoing dizziness and psychological strain after a vestibular disorder?

    PubMed

    Best, C; Tschan, R; Eckhardt-Henn, A; Dieterich, M

    2009-12-29

    Patients with vestibular vertigo syndromes often suffer from anxiety and depression, whereas patients with psychiatric disorders often experience subjective unsteadiness, dizziness, or vertigo. Thus, it has been hypothesized that the vestibular system may be interlinked with the emotion processing systems. The aim of the current study was to evaluate this hypothesis by correlating vestibular and psychiatric symptoms with the course of the disease over 1 year. This interdisciplinary, prospective, longitudinal study included a total of 68 patients with acute vestibular vertigo syndromes. Four subgroups of patients with benign paroxysmal positioning vertigo (BPPV, n=19), acute vestibular neuritis (VN, n=14), vestibular migraine (VM, n=27), or Menière's disease (MD, n=8) were compared. All patients underwent neurological and neuro-otological examinations and filled out standardized self-report inventories including the Vertigo Symptom Scale (VSS), the Vertigo Handicap Questionnaire (VHQ) and the Symptom Checklist 90R (GSI, SCL-90R) at five different times (T0-T4) in the course of 1 year. VM patients experienced significantly more "vertigo and related symptoms" (VSS-VER), "somatic anxiety and autonomic arousal" (VSS-AA), and "vertigo induced handicap" (VHQ) than all other patients (P<0.001-P=0.006). Patients with a positive history of psychiatric disorders had significantly more emotional distress (GSI, SCL-90R), regardless of the specific phenomenology of the four diagnostic subgroups. Finally, fluctuations of vestibular excitability correlated positively with the extent of subjectively perceived vertigo. VM patients are significantly more handicapped by vertigo and related symptoms. They show significantly elevated fluctuations of vestibular excitability, which correlate with the (subjective) severity of vertigo symptoms.

  11. 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

  12. Visual and proprioceptive interaction in patients with bilateral vestibular loss☆

    PubMed Central

    Cutfield, Nicholas J.; Scott, Gregory; Waldman, Adam D.; Sharp, David J.; Bronstein, Adolfo M.

    2014-01-01

    Following bilateral vestibular loss (BVL) patients gradually adapt to the loss of vestibular input and rely more on other sensory inputs. Here we examine changes in the way proprioceptive and visual inputs interact. We used functional magnetic resonance imaging (fMRI) to investigate visual responses in the context of varying levels of proprioceptive input in 12 BVL subjects and 15 normal controls. A novel metal-free vibrator was developed to allow vibrotactile neck proprioceptive input to be delivered in the MRI system. A high level (100 Hz) and low level (30 Hz) control stimulus was applied over the left splenius capitis; only the high frequency stimulus generates a significant proprioceptive stimulus. The neck stimulus was applied in combination with static and moving (optokinetic) visual stimuli, in a factorial fMRI experimental design. We found that high level neck proprioceptive input had more cortical effect on brain activity in the BVL patients. This included a reduction in visual motion responses during high levels of proprioceptive input and differential activation in the midline cerebellum. In early visual cortical areas, the effect of high proprioceptive input was present for both visual conditions but in lateral visual areas, including V5/MT, the effect was only seen in the context of visual motion stimulation. The finding of a cortical visuo-proprioceptive interaction in BVL patients is consistent with behavioural data indicating that, in BVL patients, neck afferents partly replace vestibular input during the CNS-mediated compensatory process. An fMRI cervico-visual interaction may thus substitute the known visuo-vestibular interaction reported in normal subject fMRI studies. The results provide evidence for a cortical mechanism of adaptation to vestibular failure, in the form of an enhanced proprioceptive influence on visual processing. The results may provide the basis for a cortical mechanism involved in proprioceptive substitution of vestibular

  13. Motor Performance is Impaired Following Vestibular Stimulation in Ageing Mice

    PubMed Central

    Tung, Victoria W. K.; Burton, Thomas J.; Quail, Stephanie L.; Mathews, Miranda A.; Camp, Aaron J.

    2016-01-01

    Balance and maintaining postural equilibrium are important during stationary and dynamic movements to prevent falls, particularly in older adults. While our sense of balance is influenced by vestibular, proprioceptive, and visual information, this study focuses primarily on the vestibular component and its age-related effects on balance. C57Bl/6J mice of ages 1, 5–6, 8–9 and 27–28 months were tested using a combination of standard (such as grip strength and rotarod) and newly-developed behavioral tests (including balance beam and walking trajectory tests with a vestibular stimulus). In the current study, we confirm a decline in fore-limb grip strength and gross motor coordination as age increases. We also show that a vestibular stimulus of low frequency (2–3 Hz) and duration can lead to age-dependent changes in balance beam performance, which was evident by increases in latency to begin walking on the beam as well as the number of times hind-feet slip (FS) from the beam. Furthermore, aged mice (27–28 months) that received continuous access to a running wheel for 4 weeks did not improve when retested. Mice of ages 1, 10, 13 and 27–28 months were also tested for changes in walking trajectory as a result of the vestibular stimulus. While no linear relationship was observed between the changes in trajectory and age, 1-month-old mice were considerably less affected than mice of ages 10, 13 and 27–28 months. Conclusion: this study confirms there are age-related declines in grip strength and gross motor coordination. We also demonstrate age-dependent changes to finer motor abilities as a result of a low frequency and duration vestibular stimulus. These changes showed that while the ability to perform the balance beam task remained intact across all ages tested, behavioral changes in task performance were observed. PMID:26869921

  14. Medial vestibular connections with the hypocretin (orexin) system

    NASA Technical Reports Server (NTRS)

    Horowitz, Seth S.; Blanchard, Jane; Morin, Lawrence P.

    2005-01-01

    The mammalian medial vestibular nucleus (MVe) receives input from all vestibular endorgans and provides extensive projections to the central nervous system. Recent studies have demonstrated projections from the MVe to the circadian rhythm system. In addition, there are known projections from the MVe to regions considered to be involved in sleep and arousal. In this study, afferent and efferent subcortical connectivity of the medial vestibular nucleus of the golden hamster (Mesocricetus auratus) was evaluated using cholera toxin subunit-B (retrograde), Phaseolus vulgaris leucoagglutinin (anterograde), and pseudorabies virus (transneuronal retrograde) tract-tracing techniques. The results demonstrate MVe connections with regions mediating visuomotor and postural control, as previously observed in other mammals. The data also identify extensive projections from the MVe to regions mediating arousal and sleep-related functions, most of which receive immunohistochemically identified projections from the lateral hypothalamic hypocretin (orexin) neurons. These include the locus coeruleus, dorsal and pedunculopontine tegmental nuclei, dorsal raphe, and lateral preoptic area. The MVe itself receives a projection from hypocretin cells. CTB tracing demonstrated reciprocal connections between the MVe and most brain areas receiving MVe efferents. Virus tracing confirmed and extended the MVe afferent connections identified with CTB and additionally demonstrated transneuronal connectivity with the suprachiasmatic nucleus and the medial habenular nucleus. These anatomical data indicate that the vestibular system has access to a broad array of neural functions not typically associated with visuomotor, balance, or equilibrium, and that the MVe is likely to receive information from many of the same regions to which it projects.

  15. Clinical investigation of vestibular damage by antituberculous drugs.

    PubMed

    Nakayama, M; Natori, Y; Tachi, H; Yoshizawa, M; Takayama, S; Miura, H; Kanayama, M; Kamei, T

    1986-01-01

    Vestibular function testing was done regularly on the cases given streptomycin, kanamycin, or enviomycin and a method to detect the cases of vestibular dysfunction at an early stage was discussed, as well as the time these drugs should be discontinued. Subjects were 85 cases of tuberculosis treated with streptomycin, kanamycin, or enviomycin who were admitted to our hospital from December 1984 to May 1986. The method of equilibrium examination performed at regular intervals is as follows: standing test (Romberg test), stepping test, and Meyer zum Gottesberge's head-shaking test were done once a week for a month after starting antituberculous injections and they were re-examined once every 2 weeks for at least 3 months after beginning the injections. After the 3 months these tests were done once a month. Eight cases of vestibular damage due to streptomycin or enviomycin could be easily detected at an early stage by performing Meyer zum Gottesberge's head-shaking test, together with the standing test and the stepping test. Vestibular dysfunction is apt to occur after about 1 month or within a month from the start of daily injections especially with streptomycin. Therefore, the method of equilibrium examination, we suggest, is that the Meyer zum Gottesberge's head-shaking test, the standing test (Romberg test), and the stepping test should be performed once a week during the first month after the start of this drug. When the result of the Meyer zum Gottesberge's head-shaking test is less than 50% and swaying and/or rotation occur in the stepping test, the drugs being given should be discontinued.

  16. Visuo-Vestibular Interactions

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Session TA3 includes short reports covering: (1) Vestibulo-Oculomotor Interaction in Long-Term Microgravity; (2) Effects of Weightlessness on the Spatial Orientation of Visually Induced Eye Movements; (3) Adaptive Modification of the Three-Dimensional Vestibulo-Ocular Reflex during Prolonged Microgravity; (4) The Dynamic Change of Brain Potential Related to Selective Attention to Visual Signals from Left and Right Visual Fields; (5) Locomotor Errors Caused by Vestibular Suppression; and (6) A Novel, Image-Based Technique for Three-Dimensional Eye Measurement.

  17. Framing susceptibility in a risky choice game is altered by galvanic vestibular stimulation.

    PubMed

    Preuss, Nora; Kalla, Roger; Müri, Rene; Mast, Fred W

    2017-06-07

    Recent research provides evidence that galvanic vestibular stimulation (GVS) has a modulating effect on somatosensory perception and spatial cognition. However, other vestibular stimulation techniques have induced changes in affective control and decision making. The aim of this study was to investigate the effect of GVS on framing susceptibility in a risky-choice game. The participants were to decide between a safe and a risky option. The safe option was framed either positively or negatively. During the task, the participants were exposed to either left anodal/right cathodal GVS, right anodal/left cathodal GVS, or sham stimulation (control condition). While left anodal/right cathodal GVS activated more right-hemispheric vestibular brain areas, right anodal/left cathodal GVS resulted in more bilateral activation. We observed increased framing susceptibility during left anodal/right cathodal GVS, but no change in framing susceptibility during right anodal/left cathodal GVS. We propose that GVS results in increased reliance on the affect heuristic by means of activation of cortical and subcortical vestibular-emotional brain structures and that this effect is modulated by the lateralization of the vestibular cortex.

  18. Does the vestibular system contribute to head direction cell activity in the rat?

    NASA Technical Reports Server (NTRS)

    Brown, J. E.; Yates, B. J.; Taube, J. S.; Oman, C. M. (Principal Investigator)

    2002-01-01

    Head direction cells (HDC) located in several regions of the brain, including the anterior dorsal nucleus of the thalamus (ADN), postsubiculum (PoS), and lateral mammillary nuclei (LMN), provide the neural substrate for the determination of head direction. Although activity of HDC is influenced by various sensory signals and internally generated cues, lesion studies and some anatomical and physiological evidence suggest that vestibular inputs are critical for the maintenance of directional sensitivity of these cells. However, vestibular inputs must be transformed considerably in order to signal head direction, and the neuronal circuitry that accomplishes this signal processing has not been fully established. Furthermore, it is unclear why the removal of vestibular inputs abolishes the directional sensitivity of HDC, as visual and other sensory inputs and motor feedback signals strongly affect the firing of these neurons and would be expected to maintain their directional-related activity. Further physiological studies will be required to establish the role of vestibular system in producing HDC responses, and anatomical studies are needed to determine the neural circuitry that mediates vestibular influences on determination of head direction.

  19. Vestibular ablation and a semicircular canal prosthesis affect postural stability during head turns

    PubMed Central

    Thompson, Lara A.; Haburcakova, Csilla; Lewis, Richard F.

    2016-01-01

    In our study, we examined postural stability during head turns for two rhesus monkeys: one, single animal study contrasted normal and mild bilateral vestibular ablation and a second animal study contrasted severe bilateral vestibular ablation with and without prosthetic stimulation. The monkeys freely stood, unrestrained on a balance platform and made voluntary head turns between visual targets. To quantify each animals’ posture, motions of the head and trunk, as well as torque about the body’s center-of-mass, were measured. In the mildly ablated animal, we observed less foretrunk sway in comparison to the normal state. When the canal prosthesis provided electric stimulation to the severely ablated animal, it showed a decrease in trunk sway during head turns. Because the rhesus monkey with severe bilateral vestibular loss exhibited a decrease in trunk sway when receiving vestibular prosthetic stimulation, we propose that the prosthetic electrical stimulation partially restored head velocity information. Our results provide an indication that a semicircular canal prosthesis may be an effective way to improve postural stability in patients with severe peripheral vestibular dysfunction. PMID:27405997

  20. Multivariate Analyses of Balance Test Performance, Vestibular Thresholds, and Age

    PubMed Central

    Karmali, Faisal; Bermúdez Rey, María Carolina; Clark, Torin K.; Wang, Wei; Merfeld, Daniel M.

    2017-01-01

    We previously published vestibular perceptual thresholds and performance in the Modified Romberg Test of Standing Balance in 105 healthy humans ranging from ages 18 to 80 (1). Self-motion thresholds in the dark included roll tilt about an earth-horizontal axis at 0.2 and 1 Hz, yaw rotation about an earth-vertical axis at 1 Hz, y-translation (interaural/lateral) at 1 Hz, and z-translation (vertical) at 1 Hz. In this study, we focus on multiple variable analyses not reported in the earlier study. Specifically, we investigate correlations (1) among the five thresholds measured and (2) between thresholds, age, and the chance of failing condition 4 of the balance test, which increases vestibular reliance by having subjects stand on foam with eyes closed. We found moderate correlations (0.30–0.51) between vestibular thresholds for different motions, both before and after using our published aging regression to remove age effects. We found that lower or higher thresholds across all threshold measures are an individual trait that account for about 60% of the variation in the population. This can be further distributed into two components with about 20% of the variation explained by aging and 40% of variation explained by a single principal component that includes similar contributions from all threshold measures. When only roll tilt 0.2 Hz thresholds and age were analyzed together, we found that the chance of failing condition 4 depends significantly on both (p = 0.006 and p = 0.013, respectively). An analysis incorporating more variables found that the chance of failing condition 4 depended significantly only on roll tilt 0.2 Hz thresholds (p = 0.046) and not age (p = 0.10), sex nor any of the other four threshold measures, suggesting that some of the age effect might be captured by the fact that vestibular thresholds increase with age. For example, at 60 years of age, the chance of failing is roughly 5% for the lowest roll tilt thresholds

  1. Examining the Effect of Age on Visual-Vestibular Self-Motion Perception Using a Driving Paradigm.

    PubMed

    Ramkhalawansingh, Robert; Keshavarz, Behrang; Haycock, Bruce; Shahab, Saba; Campos, Jennifer L

    2017-05-01

    Previous psychophysical research has examined how younger adults and non-human primates integrate visual and vestibular cues to perceive self-motion. However, there is much to be learned about how multisensory self-motion perception changes with age, and how these changes affect performance on everyday tasks involving self-motion. Evidence suggests that older adults display heightened multisensory integration compared with younger adults; however, few previous studies have examined this for visual-vestibular integration. To explore age differences in the way that visual and vestibular cues contribute to self-motion perception, we had younger and older participants complete a basic driving task containing visual and vestibular cues. We compared their performance against a previously established control group that experienced visual cues alone. Performance measures included speed, speed variability, and lateral position. Vestibular inputs resulted in more precise speed control among older adults, but not younger adults, when traversing curves. Older adults demonstrated more variability in lateral position when vestibular inputs were available versus when they were absent. These observations align with previous evidence of age-related differences in multisensory integration and demonstrate that they may extend to visual-vestibular integration. These findings may have implications for vehicle and simulator design when considering older users.

  2. Distorted own-body representations in patients with dizziness and during caloric vestibular stimulation.

    PubMed

    Lopez, Christophe; Nakul, Estelle; Preuss, Nora; Elzière, Maya; Mast, Fred W

    2018-06-06

    There is increasing evidence that vestibular disorders evoke deficits reaching far beyond imbalance, oscillopsia and spatial cognition. Yet, how vestibular disorders affect own-body representations, in particular the perceived body shape and size, has been overlooked. Here, we explored vestibular contributions to own-body representations using two approaches. Study 1 measured the occurrence and severity of distorted own-body representations in 60 patients with dizziness and 60 healthy controls using six items from the Cambridge Depersonalization Scale. 12% of the patients have experienced distorted own-body representations (their hands or feet felt larger or smaller), 37% reported abnormal sense of agency, 35% reported disownership for the body, and 22% reported disembodiment. These proportions were larger in patients than controls. Study 2 aimed at testing whether artificial stimulation of the vestibular apparatus produced comparable distortions of own-body representations in healthy volunteers. We compared the effects of right-warm/left-cold caloric vestibular stimulation (CVS), left-warm/right-cold CVS and sham CVS on internal models of the left and right hands using a pointing task. The perceived length of the dorsum of the hand was increased specifically during left-warm/right-cold CVS, and this effect was found for both hands. Our studies show a vestibular contribution to own-body representations and should help understand the complex symptomatology of patients with dizziness.

  3. Brain or strain? Symptoms alone do not distinguish physiologic concussion from cervical/vestibular injury.

    PubMed

    Leddy, John J; Baker, John G; Merchant, Asim; Picano, John; Gaile, Daniel; Matuszak, Jason; Willer, Barry

    2015-05-01

    To compare symptoms in patients with physiologic postconcussion disorder (PCD) versus cervicogenic/vestibular PCD. We hypothesized that most symptoms would not be equivalent. In particular, we hypothesized that cognitive symptoms would be more often associated with physiologic PCD. Retrospective review of symptom reports from patients who completed a 22-item symptom questionnaire. University-based concussion clinic. Convenience sample of 128 patients who had symptoms after head injury for more than 3 weeks and who had provocative treadmill exercise testing. Subjects were classified as either physiologic PCD (abnormal treadmill performance and a normal cervical/vestibular physical examination) or cervicogenic/vestibular PCD (CGV, normal treadmill performance, and an abnormal cervical/vestibular physical examination). Self-reported symptoms. Univariate and multivariate methods, including t tests, tests of equivalence, a logistic regression model, k-nearest neighbor analysis, multidimensional scaling, and principle components analysis were used to see whether symptoms could distinguish PCD from CGV. None of the statistical methods used to analyze self-reported symptoms was able to adequately distinguish patients with PCD from patients with CGV. Symptoms after head injury, including cognitive symptoms, have traditionally been ascribed to brain injury, but they do not reliably discriminate between physiologic PCD and cervicogenic/vestibular PCD. Clinicians should consider specific testing of exercise tolerance and perform a physical examination of the cervical spine and the vestibular/ocular systems to determine the etiology of postconcussion symptoms. Symptoms after head injury, including cognitive symptoms, do not discriminate between concussion and cervical/vestibular injury.

  4. Functional Brain Activation in Response to a Clinical Vestibular Test Correlates with Balance

    PubMed Central

    Noohi, Fatemeh; Kinnaird, Catherine; DeDios, Yiri; Kofman, Igor S.; Wood, Scott; Bloomberg, Jacob; Mulavara, Ajitkumar; Seidler, Rachael

    2017-01-01

    The current study characterizes brain fMRI activation in response to two modes of vestibular stimulation: Skull tap and auditory tone burst. The auditory tone burst has been used in previous studies to elicit either a vestibulo-spinal reflex [saccular-mediated colic Vestibular Evoked Myogenic Potentials (cVEMP)], or an ocular muscle response [utricle-mediated ocular VEMP (oVEMP)]. Research suggests that the skull tap elicits both saccular and utricle-mediated VEMPs, while being faster and less irritating for subjects than the high decibel tones required to elicit VEMPs. However, it is not clear whether the skull tap and auditory tone burst elicit the same pattern of brain activity. Previous imaging studies have documented activity in the anterior and posterior insula, superior temporal gyrus, inferior parietal lobule, inferior frontal gyrus, and the anterior cingulate cortex in response to different modes of vestibular stimulation. Here we hypothesized that pneumatically powered skull taps would elicit a similar pattern of brain activity as shown in previous studies. Our results provide the first evidence of using pneumatically powered skull taps to elicit vestibular activity inside the MRI scanner. A conjunction analysis revealed that skull taps elicit overlapping activation with auditory tone bursts in the canonical vestibular cortical regions. Further, our postural control assessments revealed that greater amplitude of brain activation in response to vestibular stimulation was associated with better balance control for both techniques. Additionally, we found that skull taps elicit more robust vestibular activity compared to auditory tone bursts, with less reported aversive effects, highlighting the utility of this approach for future clinical and basic science research. PMID:28344549

  5. Gain and phase of perceived virtual rotation evoked by electrical vestibular stimuli

    PubMed Central

    Peters, Ryan M.; Rasman, Brandon G.; Inglis, J. Timothy

    2015-01-01

    Galvanic vestibular stimulation (GVS) evokes a perception of rotation; however, very few quantitative data exist on the matter. We performed psychophysical experiments on virtual rotations experienced when binaural bipolar electrical stimulation is applied over the mastoids. We also performed analogous real whole body yaw rotation experiments, allowing us to compare the frequency response of vestibular perception with (real) and without (virtual) natural mechanical stimulation of the semicircular canals. To estimate the gain of vestibular perception, we measured direction discrimination thresholds for virtual and real rotations. Real direction discrimination thresholds decreased at higher frequencies, confirming multiple previous studies. Conversely, virtual direction discrimination thresholds increased at higher frequencies, implying low-pass filtering of the virtual perception process occurring potentially anywhere between afferent transduction and cortical responses. To estimate the phase of vestibular perception, participants manually tracked their perceived position during sinusoidal virtual and real kinetic stimulation. For real rotations, perceived velocity was approximately in phase with actual velocity across all frequencies. Perceived virtual velocity was in phase with the GVS waveform at low frequencies (0.05 and 0.1 Hz). As frequency was increased to 1 Hz, the phase of perceived velocity advanced relative to the GVS waveform. Therefore, at low frequencies GVS is interpreted as an angular velocity signal and at higher frequencies GVS becomes interpreted increasingly as an angular position signal. These estimated gain and phase spectra for vestibular perception are a first step toward generating well-controlled virtual vestibular percepts, an endeavor that may reveal the usefulness of GVS in the areas of clinical assessment, neuroprosthetics, and virtual reality. PMID:25925318

  6. Vestibular responses in the macaque pedunculopontine nucleus and central mesencephalic reticular formation

    PubMed Central

    Aravamuthan, Bhooma R.; Angelaki, Dora E.

    2012-01-01

    The pedunculopontine nucleus (PPN) and central mesencephalic reticular formation (cMRF) both send projections and receive input from areas with known vestibular responses. Noting their connections with the basal ganglia, the locomotor disturbances that occur following lesions of the PPN or cMRF, and the encouraging results of PPN deep brain stimulation in Parkinson’s disease patients, both the PPN and cMRF have been linked to motor control. In order to determine the existence of and characterize vestibular responses in the PPN and cMRF, we recorded single neurons from both structures during vertical and horizontal rotation, translation, and visual pursuit stimuli. The majority of PPN cells (72.5%) were vestibular-only cells that responded exclusively to rotation and translation stimuli but not visual pursuit. Visual pursuit responses were much more prevalent in the cMRF (57.1%) though close to half of cMRF cells were vestibular-only cells (41.1%). Directional preferences also differed between the PPN, which was preferentially modulated during nose-down pitch, and cMRF, which was preferentially modulated during ipsilateral yaw rotation. Finally, amplitude responses were similar between the PPN and cMRF during rotation and pursuit stimuli, but PPN responses to translation were of higher amplitude than cMRF responses. Taken together with their connections to the vestibular circuit, these results implicate the PPN and cMRF in the processing of vestibular stimuli and suggest important roles for both in responding to motion perturbations like falls and turns. PMID:22864184

  7. Influence of galvanic vestibular stimulation on egocentric and object-based mental transformations.

    PubMed

    Lenggenhager, Bigna; Lopez, Christophe; Blanke, Olaf

    2008-01-01

    The vestibular system analyses angular and linear accelerations of the head that are important information for perceiving the location of one's own body in space. Vestibular stimulation and in particular galvanic vestibular stimulation (GVS) that allow a systematic modification of vestibular signals has so far mainly been used to investigate vestibular influence on sensori-motor integration in eye movements and postural control. Comparatively, only a few behavioural and imaging studies have investigated how cognition of space and body may depend on vestibular processing. This study was designed to differentiate the influence of left versus right anodal GVS compared to sham stimulation on object-based versus egocentric mental transformations. While GVS was applied, subjects made left-right judgments about pictures of a plant or a human body presented at different orientations in the roll plane. All subjects reported illusory sensations of body self-motion and/or visual field motion during GVS. Response times in the mental transformation task were increased during right but not left anodal GVS for the more difficult stimuli and the larger angles of rotation. Post-hoc analyses suggested that the interfering effect of right anodal GVS was only present in subjects who reported having imagined turning themselves to solve the mental transformation task (egocentric transformation) as compared to those subjects having imagined turning the picture in space (object-based mental transformation). We suggest that this effect relies on shared functional and cortical mechanisms in the posterior parietal cortex associated with both right anodal GVS and mental imagery.

  8. Short latency vestibular evoked potentials in the Japanese quail (Coturnix coturnix japonica)

    NASA Technical Reports Server (NTRS)

    Jones, S. M.; Jones, T. A.; Shukla, R.

    1997-01-01

    Short-latency vestibular-evoked potentials to pulsed linear acceleration were characterized in the quail. Responses occurred within 8 ms following the onset of stimuli and were composed of a series of positive and negative peaks. The latencies and amplitudes of the first four peaks were quantitatively characterized. Mean latencies at 1.0 g ms-1 ranged from 1265 +/- 208 microseconds (P1, N = 18) to 4802 +/- 441 microseconds (N4, N = 13). Amplitudes ranged from 3.72 +/- 1.51 microV (P1/N1, N = 18) to 1.49 +/- 0.77 microV (P3/N3, N = 16). Latency-intensity (LI) slopes ranged from -38.7 +/- 7.3 microseconds dB-1 (P1, N = 18) to -71.6 +/- 21.9 microseconds dB-1 (N3, N = 15) and amplitude-intensity (AI) slopes ranged from 0.20 +/- 0.08 microV dB-1 (P1/N1, N = 18) to 0.07 +/- 0.04 microV dB-1 (P3/N3, N = 11). The mean response threshold across all animals was -21.83 +/- 3.34 dB re: 1.0 g ms-1 (N = 18). Responses remained after cochlear extirpation showing that they could not depend critically on cochlear activity. Responses were eliminated by destruction of the vestibular end organs, thus showing that responses depended critically and specifically on the vestibular system. The results demonstrate that the responses are vestibular and the findings provide a scientific basis for using vestibular responses to evaluate vestibular function through ontogeny and senescence in the quail.

  9. 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.

  10. Influence of Caloric Vestibular Stimulation on Body Experience in Healthy Humans

    PubMed Central

    Schönherr, Andreas; May, Christian Albrecht

    2016-01-01

    The vestibular system has more connections with and influence on higher cortical centers than previously thought. These interactions with higher cortical centers and the phenomena that they elicit require a structural intact cerebral cortex. To date, little is known about the role and influence of the vestibular system on one’s body experience. In this study we show that caloric vestibular stimulation (CVS) in healthy participants has an effect on the perceptive component of one’s body experience. After CVS all participants showed a statistically significant difference of thigh width estimation. In contrast to previous studies, which demonstrated an influence of CVS on higher cortical centers with an intact cerebral cortex both the cognitive and affective component of body experience were not effected by the CVS. Our results demonstrate the influence of the vestibular system on body perception and emphasize its role in modulating different perceptive-qualities which contributes to our body experience. We found that CVS has a limited influence on one’s conscious state, thought process and higher cortical functions. PMID:27013995

  11. 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.

  12. The vestibular system of the owl

    NASA Technical Reports Server (NTRS)

    Money, K. E.; Correia, M. J.

    1973-01-01

    Five owls were given vestibular examinations, and two of them were sacrificed to provide serial histological sections of the temporal bones. The owls exhibited a curious variability in the postrotatory head nystagmus following abrupt deceleration; sometimes a brisk nystagnus with direction opposite to that appropriate to the stimulus would occur promptly after deceleration. It was found also that owls can exhibit a remarkable head stability during angular movement of the body about any axis passing through the skull. The vestibular apparatus in the owl is larger than in man, and a prominent crista neglecta is present. The tectorial membrane, the cupula, and the otolithic membranes of the utricle, saccule, and lagena are all attached to surfaces in addition to the surfaces hearing hair cells. These attachments are very substantial in the utricular otolithic membrane and in the cupula.

  13. Astronaut Owen Garriott - Test Subject - Human Vestibular Function Experiment

    NASA Image and Video Library

    1973-08-09

    S73-34171 (9 Aug. 1973) --- Scientist-astronaut Owen K. Garriott, Skylab 3 science pilot, serves as test subject for the Skylab ?Human Vestibular Function? M131 Experiment, as seen in this photographic reproduction taken from a television transmission made by a color TV camera aboard the Skylab space station in Earth orbit. The objectives of the Skylab M131 experiment are to obtain data pertinent to establishing the validity of measurements of specific behavioral/physiological responses influenced by vestibular activity under one-g and zero-g conditions; to determine man?s adaptability to unusual vestibular conditions and predict habitability of future spacecraft conditions involving reduced gravity and Coriollis forces; and to measure the accuracy and variability in man?s judgment of spatial coordinates based on atypical gravity receptor cues and inadequate visual cures. Dr. Garriott is seated in the experiment?s litter chair which can rotate the test subject at predetermined rotational velocity or programmed acceleration/decelerational profile. Photo credit: NASA

  14. Sex Differences in Vestibular/Ocular and Neurocognitive Outcomes After Sport-Related Concussion.

    PubMed

    Sufrinko, Alicia M; Mucha, Anne; Covassin, Tracey; Marchetti, Greg; Elbin, R J; Collins, Michael W; Kontos, Anthony P

    2017-03-01

    To examine sex differences in vestibular and oculomotor symptoms and impairment in athletes with sport-related concussion (SRC). The secondary purpose was to replicate previously reported sex differences in total concussion symptoms, and performance on neurocognitive and balance testing. Prospective cross-sectional study of consecutively enrolled clinic patients within 21 days of a SRC. Specialty Concussion Clinic. Included male (n = 36) and female (n = 28) athletes ages 9 to 18 years. Vestibular symptoms and impairment was measured with the Vestibular/Ocular Motor Screening (VOMS). Participants completed the Immediate Post-concussion Assessment and Cognitive Test (ImPACT), Post-concussion Symptom Scale (PCSS), and Balance Error Scoring System (BESS). Sex differences on clinical measures. Females had higher PCSS scores (P = 0.01) and greater VOMS vestibular ocular reflex (VOR) score (P = 0.01) compared with males. There were no sex differences on BESS or ImPACT. Total PCSS scores together with female sex accounted for 45% of the variance in VOR scores. Findings suggest higher VOR scores after SRC in female compared with male athletes. Findings did not extend to other components of the VOMS tool suggesting that sex differences may be specific to certain types of vestibular impairment after SRC. Additional research on the clinical significance of the current findings is needed.

  15. Immunohistochemical localization of calcium-binding proteins in the brainstem vestibular nuclei of the jaundiced Gunn rat.

    PubMed

    Shaia, Wayne T; Shapiro, Steven M; Heller, Andrew J; Galiani, David L; Sismanis, Aristides; Spencer, Robert F

    2002-11-01

    Vestibular gaze and postural abnormalities are major sequelae of neonatal hyperbilirubinemia. The sites and cellular effects of bilirubin toxicity in the brainstem vestibular pathway are not easily detected. Since altered intracellular calcium homeostasis may play a role in neuronal cell death, we hypothesized that altered expression of calcium-binding proteins may occur in brainstem vestibular nuclei of the classic animal model of bilirubin neurotoxicity. The expression of the calcium-binding proteins calbindin-D28k and parvalbumin in the brainstem vestibular pathways and cerebellum of homozygous recessive jaundiced (jj) Gunn rats was examined by light microscopy and immunohistochemistry at 18 days postnatally and compared to the findings obtained from age-matched non-jaundiced heterozygous (Nj) littermate controls. Jaundiced animals exhibited decreased parvalbumin immunoreactivity specifically in synaptic inputs to superior, medial, and inferior vestibular nuclei, and to oculomotor and trochlear nuclei, whereas the neurons retained their normal immunoreactivity. Jaundiced animals also demonstrated a decrease in calbindin expression in the lateral vestibular nuclei and a paucity of calbindin-immunoreactive synaptic endings on the somata of Deiters' neurons. The involved regions are related to the control of the vestibulo-ocular and vestibulospinal reflexes. Decreased expression of calcium-binding proteins in brainstem vestibular neurons may relate to the vestibulo-ocular and vestibulospinal dysfunction seen with clinical kernicterus, and may provide a sensitive new way to assess bilirubin toxicity in the vestibular system.

  16. Evaluation of Galvanic Vestibular Stimulation System

    NASA Technical Reports Server (NTRS)

    Kofman, I. S.; Warren, E.; DeSoto, R.; Moroney, G.; Chastain, J.; De Dios, Y. E.; Gadd, N.; Taylor, L.; Peters, B. T.; Allen, E.; hide

    2017-01-01

    Microgravity exposure results in an adaptive central reinterpretation of information from multiple sensory sources to produce a sensorimotor state appropriate for motor actions in this unique environment, but this new adaptive state is no longer appropriate for the 1-g gravitational environment on Earth. During these gravitational transitions, astronauts experience deficits in both perceptual and motor functions including impaired postural control, disruption in spatial orientation, impaired control of locomotion that include alterations in muscle activation variability, modified lower limb kinematics, alterations in head-trunk coordination as well as reduced dynamic visual acuity. Post-flight changes in postural and locomotor control might have adverse consequences if a rapid egress was required following a long-duration mission, where support personnel may not be available to aid crewmembers. The act of emergency egress includes, but is not limited to standing, walking, climbing a ladder, jumping down, monitoring displays, actuating discrete controls, operating auxiliary equipment, and communicating with Mission Control and recovery teams while maintaining spatial orientation, mobility and postural stability in order to escape safely. The average time to recover impaired postural control and functional mobility to preflight levels of performance has been shown to be approximately two weeks after long-duration spaceflight. The postflight alterations are due in part to central reinterpretation of vestibular information caused by exposure to microgravity. In this study we will use a commonly used technique of transcutaneous electrical stimulation applied across the vestibular end organs (galvanic vestibular stimulation, GVS) to disrupt vestibular function as a simulation of post-flight disturbances. The goal of this project is an engineering human-in-the-loop evaluation of a device that can degrade performance of functional tasks (e.g. to maintain upright balance

  17. Vestibular response to pseudorandom angular velocity input: progress report.

    PubMed

    Lessard, C S; Wong, W C

    1987-09-01

    Space motion sickness was not reported during the first Apollo missions; however, since Apollo 8 through the current Shuttle and Skylab missions, approximately 50% of the crewmembers have experienced instances of space motion sickness. One of NASA's efforts to resolve the space adaptation syndrome is to model the vestibular response for both basic knowledge and as a possible predictor of an individual's susceptibility to the disorder. This report describes a method to analyze the vestibular system when subjected to a pseudorandom angular velocity input.

  18. Sensory Reinforcement: Effects of Response-Contingent Vestibular Stimulation on Multiply Handicapped Children.

    ERIC Educational Resources Information Center

    Sandler, Allen G.; McLain, Susan C.

    1987-01-01

    Investigation of the reinforcing properties of vestibular stimulation with five multiply disabled severely retarded young children indicated that vestibular stimulation (10 seconds of swinging) was reinforcing to all subjects and was preferred (over food, praise, visual, and auditory stimulation) by four of the five children. (Author/DB)

  19. Zebrafish pax5 regulates development of the utricular macula and vestibular function.

    PubMed

    Kwak, Su-Jin; Vemaraju, Shruti; Moorman, Stephen J; Zeddies, David; Popper, Arthur N; Riley, Bruce B

    2006-11-01

    The zebrafish otic vesicle initially forms with only two sensory epithelia, the utricular and saccular maculae, which primarily mediate vestibular and auditory function, respectively. Here, we test the role of pax5, which is preferentially expressed in the utricular macula. Morpholino knockdown of pax5 disrupts vestibular function but not hearing. Neurons of the statoacoustic ganglion (SAG) develop normally. Utricular hair cells appear to form normally but a variable number subsequently undergo apoptosis and are extruded from the otic vesicle. Dendrites of the SAG persist in the utricle but become disorganized after hair cell loss. Hair cells in the saccule develop and survive normally. Otic expression of pax5 requires pax2a and fgf3, mutations in which cause vestibular defects, albeit by distinct mechanisms. Thus, pax5 works in conjunction with fgf3 and pax2a to establish and/or maintain the utricular macula and is essential for vestibular function. (c) 2006 Wiley-Liss, Inc.

  20. Objective vestibular testing of children with dizziness and balance complaints following sports-related concussions.

    PubMed

    Zhou, Guangwei; Brodsky, Jacob R

    2015-06-01

    To conduct objective assessment of children with balance and vestibular complaints following sports-related concussions and identify the underlying deficits by analyzing laboratory test outcomes. Case series with chart review. Pediatric tertiary care facility. Medical records were reviewed of 42 pediatric patients with balance and/or vestibular complaints following sports-related concussions who underwent comprehensive laboratory testing on their balance and vestibular function. Patients' characteristics were summarized and results analyzed. More than 90% of the children with protracted dizziness or imbalance following sports-related concussion had at least 1 abnormal finding from the comprehensive balance and vestibular evaluation. The most frequent deficit was found in dynamic visual acuity test, followed by Sensory Organization Test and rotational test. Patient's balance problem associated with concussion seemed to be primarily instigated by vestibular dysfunction. Furthermore, semicircular canal dysfunction was involved more often than dysfunction of otolith organs. Yet, <10% of the children experienced a hearing loss following sports-related concussion. Vestibular impairment is common among children with protracted dizziness or imbalance following sports-related concussion. Our study demonstrated that proper and thorough evaluation is imperative to identify these underlying deficits and laboratory tests were helpful in the diagnosis and recommendation of following rehabilitations. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

  1. Unilateral vestibular schwannoma in a patient with schwannomatosis in the absence of LZTR1 mutation

    PubMed Central

    Mehta, Gautam U.; Feldman, Michael J.; Wang, Herui; Ding, Dale; Chittiboina, Prashant

    2016-01-01

    The presence of vestibular schwannomas has long been considered an exclusion criterion for the diagnosis of schwannomatosis. Recently, 2 cases of vestibular schwannoma were reported in patients with schwannomatosis, leading to a revision of the diagnostic criteria for this genetic disorder. Overall, the relative infrequency of vestibular schwannomas in schwannomatosis is unexplained, and the genetics of this uncommon phenomenon have not been described. The authors report on a family with clinical manifestations consistent with schwannomatosis, including 4 affected members, that was identified as having an affected member harboring a unilateral cerebellopontine angle mass with extension into the internal auditory canal. Radiologically, this mass was consistent with a vestibular schwannoma and resulted in a symptomatic change in ipsilateral hearing (word recognition 86% at 52 dB) and increased latency of the wave I–V interval on auditory brainstem response testing. The patient was found to be negative for a germline mutation of NF2 and LZTR1, and her affected mother was found to harbor neither NF2 nor SMARCB1 mutations on genetic testing. Although vestibular schwannomas have been classically considered to not occur in the setting of schwannomatosis, this patient with schwannomatosis and a vestibular schwannoma further confirms that schwannomas can occur on the vestibular nerve in this syndrome. Further, this is the first such case found to be negative for a mutation on the LZTR1 gene. PMID:26848914

  2. Unilateral vestibular schwannoma in a patient with schwannomatosis in the absence of LZTR1 mutation.

    PubMed

    Mehta, Gautam U; Feldman, Michael J; Wang, Herui; Ding, Dale; Chittiboina, Prashant

    2016-12-01

    The presence of vestibular schwannomas has long been considered an exclusion criterion for the diagnosis of schwannomatosis. Recently, 2 cases of vestibular schwannoma were reported in patients with schwannomatosis, leading to a revision of the diagnostic criteria for this genetic disorder. Overall, the relative infrequency of vestibular schwannomas in schwannomatosis is unexplained, and the genetics of this uncommon phenomenon have not been described. The authors report on a family with clinical manifestations consistent with schwannomatosis, including 4 affected members, that was identified as having an affected member harboring a unilateral cerebellopontine angle mass with extension into the internal auditory canal. Radiologically, this mass was consistent with a vestibular schwannoma and resulted in a symptomatic change in ipsilateral hearing (word recognition 86% at 52 dB) and increased latency of the wave I-V interval on auditory brainstem response testing. The patient was found to be negative for a germline mutation of NF2 and LZTR1, and her affected mother was found to harbor neither NF2 nor SMARCB1 mutations on genetic testing. Although vestibular schwannomas have been classically considered to not occur in the setting of schwannomatosis, this patient with schwannomatosis and a vestibular schwannoma further confirms that schwannomas can occur on the vestibular nerve in this syndrome. Further, this is the first such case found to be negative for a mutation on the LZTR1 gene.

  3. Current practices in vestibular schwannoma management: a survey of American and Canadian neurosurgeons.

    PubMed

    Fusco, Matthew R; Fisher, Winfield S; McGrew, Benjamin M; Walters, Beverly C

    2014-12-01

    Comprehensive therapy for vestibular schwannomas has changed dramatically over the past fifty years. Previously, neurosurgeons were most likely to treat these tumors via an independent surgical approach. Currently, many neurosurgeons treat vestibular schwannomas employing an interdisciplinary team approach with neuro-otologists and radiation oncologists. This survey aims to determine the current treatment paradigm for vestibular schwannomas among American and Canadian neurosurgeons, with particular attention to the utilization of a team approach to the surgical resection of these lesions. A seventeen part survey questionnaire was sent by electronic mail to residency trained members of the American Association of Neurological Surgeons currently practicing in Canada or the United States. Questions were divided into groups regarding physician background, overall practice history, recent practice history, opinions on treatment paradigms, and experience with an interdisciplinary team approach. Seven hundred and six responses were received. The vast majority of neurosurgeons surgically resect vestibular schwannomas as part of an interdisciplinary team (85.7%). Regional variations were observed in the use of an interdisciplinary team: 52.3% of responding neurosurgeons who surgically treat vestibular schwannomas without neuro-otologists currently practice in the South (no other region represented more than 15.4% of this group, p=0.02). Surgeons who have treated >50 vestibular schwannomas show a trend towards more frequent utilization of an interdisciplinary approach than less experienced surgeons, but this did not reach statistical significance. The majority of neurosurgeons in the United States and Canada surgically resect vestibular schwannomas via an interdisciplinary approach with the participation of a neuro-otologist. Neurosurgeons in the South appear more likely to surgically treat these tumors alone than neurosurgeons in other regions of the U.S. and Canada

  4. 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

  5. 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.

  6. Visual Vestibular Interaction in the Dynamic Visual Acuity Test during Voluntary Head Rotation

    NASA Technical Reports Server (NTRS)

    Lee, Moo Hoon; Durnford, Simon; Crowley, John; Rupert, Angus

    1996-01-01

    Although intact vestibular function is essential in maintaining spatial orientation, no good screening tests of vestibular function are available to the aviation community. High frequency voluntary head rotation was selected as a vestibular stimulus to isolate the vestibulo-ocular reflex (VOR) from visual influence. A dynamic visual acuity test that incorporates voluntary head rotation was evaluated as a potential vestibular function screening tool. Twenty-seven normal subjects performed voluntary sinusoidal head rotation at frequencies from 0.7-4.0 Hz under three different visual conditions: visually-enhanced VOR, normal VOR, and visually suppressed VOR. Standardized Baily-Lovie chart letters were presented on a computer monitor in front of the subject, who then was asked to read the letters while rotating his head horizontally. The electro-oculogram and dynamic visual acuity score were recorded and analyzed. There were no significant differences in gain or phase shift among three visual conditions in the frequency range of 2.8 to 4.0 Hz. The dynamic visual acuity score shifted less than 0.3 logMAR at frequencies under 2.0 Hz. The dynamic visual acuity test at frequencies a round 2.0 Hz can be recommended for evaluating vestibular function.

  7. Central adaptation to repeated galvanic vestibular stimulation: implications for pre-flight astronaut training.

    PubMed

    Dilda, Valentina; Morris, Tiffany R; Yungher, Don A; MacDougall, Hamish G; Moore, Steven T

    2014-01-01

    Healthy subjects (N = 10) were exposed to 10-min cumulative pseudorandom bilateral bipolar Galvanic vestibular stimulation (GVS) on a weekly basis for 12 weeks (120 min total exposure). During each trial subjects performed computerized dynamic posturography and eye movements were measured using digital video-oculography. Follow up tests were conducted 6 weeks and 6 months after the 12-week adaptation period. Postural performance was significantly impaired during GVS at first exposure, but recovered to baseline over a period of 7-8 weeks (70-80 min GVS exposure). This postural recovery was maintained 6 months after adaptation. In contrast, the roll vestibulo-ocular reflex response to GVS was not attenuated by repeated exposure. This suggests that GVS adaptation did not occur at the vestibular end-organs or involve changes in low-level (brainstem-mediated) vestibulo-ocular or vestibulo-spinal reflexes. Faced with unreliable vestibular input, the cerebellum reweighted sensory input to emphasize veridical extra-vestibular information, such as somatosensation, vision and visceral stretch receptors, to regain postural function. After a period of recovery subjects exhibited dual adaption and the ability to rapidly switch between the perturbed (GVS) and natural vestibular state for up to 6 months.

  8. 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.

  9. Optimal Stimulus Amplitude for Vestibular Stochastic Stimulation to Improve Sensorimotor Function

    NASA Technical Reports Server (NTRS)

    Goel, R.; Kofman, I.; DeDios, Y. E.; Jeevarajan, J.; Stepanyan, V.; Nair, M.; Congdon, S.; Fregia, M.; Cohen, H.; Bloomberg, J. J.; hide

    2014-01-01

    Sensorimotor changes such as postural and gait instabilities can affect the functional performance of astronauts when they transition across different gravity environments. We are developing a method, based on stochastic resonance (SR), to enhance information transfer by applying non-zero levels of external noise on the vestibular system (vestibular stochastic resonance, VSR). Our previous work has shown the advantageous effects of VSR in a balance task of standing on an unstable surface. This technique to improve detection of vestibular signals uses a stimulus delivery system that is wearable or portable and provides imperceptibly low levels of white noise-based binaural bipolar electrical stimulation of the vestibular system. The goal of this project is to determine optimal levels of stimulation for SR applications by using a defined vestibular threshold of motion detection. A series of experiments were carried out to determine a robust paradigm to identify a vestibular threshold that can then be used to recommend optimal stimulation levels for SR training applications customized to each crewmember. Customizing stimulus intensity can maximize treatment effects. The amplitude of stimulation to be used in the VSR application has varied across studies in the literature such as 60% of nociceptive stimulus thresholds. We compared subjects' perceptual threshold with that obtained from two measures of body sway. Each test session was 463s long and consisted of several 15s sinusoidal stimuli, at different current amplitudes (0-2 mA), interspersed with 20-20.5s periods of no stimulation. Subjects sat on a chair with their eyes closed and had to report their perception of motion through a joystick. A force plate underneath the chair recorded medio-lateral shear forces and roll moments. First we determined the percent time during stimulation periods for which perception of motion (activity above a pre-defined threshold) was reported using the joystick, and body sway (two

  10. Gain and phase of perceived virtual rotation evoked by electrical vestibular stimuli.

    PubMed

    Peters, Ryan M; Rasman, Brandon G; Inglis, J Timothy; Blouin, Jean-Sébastien

    2015-07-01

    Galvanic vestibular stimulation (GVS) evokes a perception of rotation; however, very few quantitative data exist on the matter. We performed psychophysical experiments on virtual rotations experienced when binaural bipolar electrical stimulation is applied over the mastoids. We also performed analogous real whole body yaw rotation experiments, allowing us to compare the frequency response of vestibular perception with (real) and without (virtual) natural mechanical stimulation of the semicircular canals. To estimate the gain of vestibular perception, we measured direction discrimination thresholds for virtual and real rotations. Real direction discrimination thresholds decreased at higher frequencies, confirming multiple previous studies. Conversely, virtual direction discrimination thresholds increased at higher frequencies, implying low-pass filtering of the virtual perception process occurring potentially anywhere between afferent transduction and cortical responses. To estimate the phase of vestibular perception, participants manually tracked their perceived position during sinusoidal virtual and real kinetic stimulation. For real rotations, perceived velocity was approximately in phase with actual velocity across all frequencies. Perceived virtual velocity was in phase with the GVS waveform at low frequencies (0.05 and 0.1 Hz). As frequency was increased to 1 Hz, the phase of perceived velocity advanced relative to the GVS waveform. Therefore, at low frequencies GVS is interpreted as an angular velocity signal and at higher frequencies GVS becomes interpreted increasingly as an angular position signal. These estimated gain and phase spectra for vestibular perception are a first step toward generating well-controlled virtual vestibular percepts, an endeavor that may reveal the usefulness of GVS in the areas of clinical assessment, neuroprosthetics, and virtual reality. Copyright © 2015 the American Physiological Society.

  11. Vestibular-ocular accommodation reflex in man

    NASA Technical Reports Server (NTRS)

    Clark, B.; Randle, R. J.; Stewart, J. D.

    1975-01-01

    Stimulation of the vestibular system by angular acceleration produces widespread sensory and motor effects. The present paper studies a motor effect which has not been reported in the literature, i.e., the influence of rotary acceleration of the body on ocular accommodation. The accommodation of 10 young men was recorded before and after a high-level deceleration to zero velocity following 30 sec of rotating. Accommodation was recorded continuously on an infrared optometer for 110 sec under two conditions: while the subjects observed a target set at the far point, and while they viewed the same target through a 0.3-mm pinhole. Stimulation by high-level rotary deceleration produced positive accommodation or a pseudomyopia under both conditions, but the positive accommodation was substantially greater and lasted much longer during fixation through the pinhole. It is hypothesized that this increase in accommodation is a result of a vestibular-ocular accommodation reflex.

  12. 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

  13. Sympathetic Arousal to a Vestibular Stressor in High and Low Hostile Men

    ERIC Educational Resources Information Center

    Carmona, Joseph E.; Holland, Alissa K.; Stratton, Harrison J.; Harrison, David W.

    2008-01-01

    The aim of the present experiment was to extend the literature on hostility and a cerebral systems based model of sympathetic arousal to a vestibular-based stress. Several authors have concluded that autonomic stress reactivity in high hostile individuals must be interpersonally based, whereas healthy vestibular system functioning does not depend…

  14. Vestibular factors influencing the biomedical support of humans in space

    NASA Astrophysics Data System (ADS)

    Lichtenberg, Byron K.

    This paper will describe the biomedical support aspects of humans in space with respect to the vestibular system. The vestibular system is thought to be the primary sensory system involved in the short-term effects of space motion sickness although there is increasing evidence that many factors play a role in this complex set of symptoms. There is the possibility that an individual's inner sense of orientation may be strongly coupled with the susceptibility to space motion sickness. A variety of suggested countermeasures for space motion sickness will be described. Although there are no known ground-based tests that can predict space motion sickness, the search should go on. The long term effects of the vestibular system in weightlessness are still relatively unknown. Some preliminary data has shown that the otoconia are irregular in size and distribution following extended periods of weightlessness. The ramifications of this data are not yet known and because the data was obtained on lower order animals, definitive studies and results must wait until the space station era when higher primates can be studied for long durations. This leads us to artificial gravity, the last topic of this paper. The vestibular system is intimately tied to this question since it has been shown on Earth that exposure to a slow rotating room causes motion sickness for some period of time before adaptation occurs. If the artificial gravity is intermittent, will this mean that people will get sick every time they experience it? The data from many astronauts returning to Earth indicates that a variety of sensory illusions are present, especially immediately upon return to a 1- g environment. Oscillopsia or apparent motion of the visual surround upon head motion along with inappropriate eye motions for a given head motion, all indicate that there is much to be studied yet about the vestibular and CNS systems reaction to a sudden application of a steady state acceleration field like 1- g

  15. Vestibular factors influencing the biomedical support of humans in space

    NASA Technical Reports Server (NTRS)

    Lichtenberg, B. K.

    1988-01-01

    This paper will describe the biomedical support aspects of humans in space with respect to the vestibular system. The vestibular system is thought to be the primary sensory system involved in the short-term effects of space motion sickness although there is increasing evidence that many factors play a role in this complex set of symptoms. There is the possibility that an individual's inner sense of orientation may be strongly coupled with the susceptibility to space motion sickness. A variety of suggested countermeasures for space motion sickness will be described. Although there are no known ground-based tests that can predict space motion sickness, the search should go on. The long term effects of the vestibular system in weightlessness are still relatively unknown. Some preliminary data has shown that the otoconia are irregular in size and distribution following extended periods of weightlessness. The ramifications of this data are not yet known and because the data was obtained on lower order animals, definitive studies and results must wait until the space station era when higher primates can be studied for long durations. This leads us to artificial gravity, the last topic of this paper. The vestibular system is intimately tied to this question since it has been shown on Earth that exposure to a slow rotating room causes motion sickness for some period of time before adaptation occurs. If the artificial gravity is intermittent, will this mean that people will get sick every time they experience it? The data from many astronauts returning to Earth indicates that a variety of sensory illusions are present, especially immediately upon return to a 1-g environment. Oscillopsia or apparent motion of the visual surround upon head motion along with inappropriate eye motions for a given head motion, all indicate that there is much to be studied yet about the vestibular and CNS systems reaction to a sudden application of a steady state acceleration field like 1-g. From

  16. Vestibular factors influencing the biomedical support of humans in space.

    PubMed

    Lichtenberg, B K

    1988-01-01

    This paper will describe the biomedical support aspects of humans in space with respect to the vestibular system. The vestibular system is thought to be the primary sensory system involved in the short-term effects of space motion sickness although there is increasing evidence that many factors play a role in this complex set of symptoms. There is the possibility that an individual's inner sense of orientation may be strongly coupled with the susceptibility to space motion sickness. A variety of suggested countermeasures for space motion sickness will be described. Although there are no known ground-based tests that can predict space motion sickness, the search should go on. The long term effects of the vestibular system in weightlessness are still relatively unknown. Some preliminary data has shown that the otoconia are irregular in size and distribution following extended periods of weightlessness. The ramifications of this data are not yet known and because the data was obtained on lower order animals, definitive studies and results must wait until the space station era when higher primates can be studied for long durations. This leads us to artificial gravity, the last topic of this paper. The vestibular system is intimately tied to this question since it has been shown on Earth that exposure to a slow rotating room causes motion sickness for some period of time before adaptation occurs. If the artificial gravity is intermittent, will this mean that people will get sick every time they experience it? The data from many astronauts returning to Earth indicates that a variety of sensory illusions are present, especially immediately upon return to a 1-g environment. Oscillopsia or apparent motion of the visual surround upon head motion along with inappropriate eye motions for a given head motion, all indicate that there is much to be studied yet about the vestibular and CNS systems reaction to a sudden application of a steady state acceleration field like 1-g. From

  17. Cross-Modal Attention Effects in the Vestibular Cortex during Attentive Tracking of Moving Objects.

    PubMed

    Frank, Sebastian M; Sun, Liwei; Forster, Lisa; Tse, Peter U; Greenlee, Mark W

    2016-12-14

    The midposterior fundus of the Sylvian fissure in the human brain is central to the cortical processing of vestibular cues. At least two vestibular areas are located at this site: the parietoinsular vestibular cortex (PIVC) and the posterior insular cortex (PIC). It is now well established that activity in sensory systems is subject to cross-modal attention effects. Attending to a stimulus in one sensory modality enhances activity in the corresponding cortical sensory system, but simultaneously suppresses activity in other sensory systems. Here, we wanted to probe whether such cross-modal attention effects also target the vestibular system. To this end, we used a visual multiple-object tracking task. By parametrically varying the number of tracked targets, we could measure the effect of attentional load on the PIVC and the PIC while holding the perceptual load constant. Participants performed the tracking task during functional magnetic resonance imaging. Results show that, compared with passive viewing of object motion, activity during object tracking was suppressed in the PIVC and enhanced in the PIC. Greater attentional load, induced by increasing the number of tracked targets, was associated with a corresponding increase in the suppression of activity in the PIVC. Activity in the anterior part of the PIC decreased with increasing load, whereas load effects were absent in the posterior PIC. Results of a control experiment show that attention-induced suppression in the PIVC is stronger than any suppression evoked by the visual stimulus per se. Overall, our results suggest that attention has a cross-modal modulatory effect on the vestibular cortex during visual object tracking. In this study we investigate cross-modal attention effects in the human vestibular cortex. We applied the visual multiple-object tracking task because it is known to evoke attentional load effects on neural activity in visual motion-processing and attention-processing areas. Here we

  18. Postural Control in Bilateral Vestibular Failure: Its Relation to Visual, Proprioceptive, Vestibular, and Cognitive Input.

    PubMed

    Sprenger, Andreas; Wojak, Jann F; Jandl, Nico M; Helmchen, Christoph

    2017-01-01

    Patients with bilateral vestibular failure (BVF) suffer from postural and gait unsteadiness with an increased risk of falls. The aim of this study was to elucidate the differential role of otolith, semicircular canal (SSC), visual, proprioceptive, and cognitive influences on the postural stability of BVF patients. Center-of-pressure displacements were recorded by posturography under six conditions: target visibility; tonic head positions in the pitch plane; horizontal head shaking; sensory deprivation; dual task; and tandem stance. Between-group analysis revealed larger postural sway in BVF patients on eye closure; but with the eyes open, BVF did not differ from healthy controls (HCs). Head tilts and horizontal head shaking increased sway but did not differ between groups. In the dual task condition, BVF patients maintained posture indistinguishable from controls. On foam and tandem stance, postural sway was larger in BVF, even with the eyes open. The best predictor for the severity of bilateral vestibulopathy was standing on foam with eyes closed. Postural control of our BVF was indistinguishable from HCs once visual and proprioceptive feedback is provided. This distinguishes them from patients with vestibulo-cerebellar disorders or functional dizziness. It confirms previous reports and explains that postural unsteadiness of BVF patients can be missed easily if not examined by conditions of visual and/or proprioceptive deprivation. In fact, the best predictor for vestibular hypofunction (VOR gain) was examining patients standing on foam with the eyes closed. Postural sway in that condition increased with the severity of vestibular impairment but not with disease duration. In the absence of visual control, impaired otolith input destabilizes BVF with head retroflexion. Stimulating deficient SSC does not distinguish patients from controls possibly reflecting a shift of intersensory weighing toward proprioceptive-guided postural control. Accordingly, proprioceptive

  19. Postural Control in Bilateral Vestibular Failure: Its Relation to Visual, Proprioceptive, Vestibular, and Cognitive Input

    PubMed Central

    Sprenger, Andreas; Wojak, Jann F.; Jandl, Nico M.; Helmchen, Christoph

    2017-01-01

    Patients with bilateral vestibular failure (BVF) suffer from postural and gait unsteadiness with an increased risk of falls. The aim of this study was to elucidate the differential role of otolith, semicircular canal (SSC), visual, proprioceptive, and cognitive influences on the postural stability of BVF patients. Center-of-pressure displacements were recorded by posturography under six conditions: target visibility; tonic head positions in the pitch plane; horizontal head shaking; sensory deprivation; dual task; and tandem stance. Between-group analysis revealed larger postural sway in BVF patients on eye closure; but with the eyes open, BVF did not differ from healthy controls (HCs). Head tilts and horizontal head shaking increased sway but did not differ between groups. In the dual task condition, BVF patients maintained posture indistinguishable from controls. On foam and tandem stance, postural sway was larger in BVF, even with the eyes open. The best predictor for the severity of bilateral vestibulopathy was standing on foam with eyes closed. Postural control of our BVF was indistinguishable from HCs once visual and proprioceptive feedback is provided. This distinguishes them from patients with vestibulo-cerebellar disorders or functional dizziness. It confirms previous reports and explains that postural unsteadiness of BVF patients can be missed easily if not examined by conditions of visual and/or proprioceptive deprivation. In fact, the best predictor for vestibular hypofunction (VOR gain) was examining patients standing on foam with the eyes closed. Postural sway in that condition increased with the severity of vestibular impairment but not with disease duration. In the absence of visual control, impaired otolith input destabilizes BVF with head retroflexion. Stimulating deficient SSC does not distinguish patients from controls possibly reflecting a shift of intersensory weighing toward proprioceptive-guided postural control. Accordingly, proprioceptive

  20. 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

  1. Natural history of vestibular schwannomas and hearing loss in NF2 patients.

    PubMed

    Peyre, M; Bernardeschi, D; Sterkers, O; Kalamarides, M

    2015-07-13

    Bilateral vestibular schwannomas are the hallmark of neurofibromatosis 2 (NF2), occurring in 95% of patients. These tumors are associated with significant morbidity due to hearing loss, tinnitus, imbalance and facial weakness. As radiosurgery and chemotherapy have been recently introduced in the treatment armamentarium in addition to surgery, a thorough evaluation of vestibular schwannoma natural history is mandatory to determine the role and timing of each treatment modality. An exhaustive review of the literature was performed using the PubMed database concerning the natural history of tumor growth and hearing loss in NF2 patients with vestibular schwannomas. Although some aspects of vestibular schwannoma natural history remain uncertain (pattern of tumor growth, mean tumor growth rate), factors influencing growth such as age at presentation and paracrine factors are well established. Studies focusing on the natural history of hearing have highlighted different patterns of hearing loss and the possible role of intralabyrinthine tumors. The polyclonality of vestibular schwannomas in NF2 was recently unveiled, giving a new perspective to their growth mechanisms. An uniform evaluation of tumor growth using volumetric evaluation and hearing with standard classifications will ensure the use of common endpoints and should improve the quality of clinical trials as well as foster comparison among studies while ensuring more consistency in decision-making. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  2. Vestibular (dys)function in children with sensorineural hearing loss: a systematic review.

    PubMed

    Verbecque, Evi; Marijnissen, Tessa; De Belder, Niels; Van Rompaey, Vincent; Boudewyns, An; Van de Heyning, Paul; Vereeck, Luc; Hallemans, Ann

    2017-06-01

    The objective of this study is to provide an overview of the prevalence of vestibular dysfunction in children with SNHL classified according to the applied test and its corresponding sensitivity and specificity. Data were gathered using a systematic search query including reference screening. Pubmed, Web of Science and Embase were searched. Strategy and reporting of this review was based on the Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines. Methodological quality was assessed with the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist. All studies, regardless the applied vestibular test, showed that vestibular function differs significantly between children with hearing loss and normal hearing (p < 0.05). Compared with caloric testing, the sensitivity of the Rotational Chair Test (RCT) varies between 61 and 80% and specificity between 21 and 80%, whereas this was, respectively, 71-100% and 30-100% for collic Vestibular Evoked Myogenic Potentials (cVEMP). Compared with RCT, the sensitivity was 88-100% and the specificity was 69-100% for the Dynamic Visual Acuity test, respectively, 67-100% and 71-100% for the (video) Head Impulse Test and 83% and 86% for the ocular VEMP. Currently, due to methodological shortcoming, evidence on sensitivity and specificity of vestibular tests is unknown to moderate. Future research should focus on adequate sample sizes (subgroups >30).

  3. Postural Effects of Vestibular Manipulation Depend on the Physical Activity Status

    PubMed Central

    Maitre, Julien; Paillard, Thierry

    2016-01-01

    The purpose of this study was to compare the effects of galvanic vestibular stimulation (GVS) on postural control for participants of different physical activity status (i.e. active and non-active). Two groups of participants were recruited: one group of participants who regularly practised sports activities (active group, n = 17), and one group of participants who did not practise physical and/or sports activities (non-active group, n = 17). They were compared in a reference condition (i.e bipedal stance with eyes open) and four vestibular manipulation condition (i.e. GVS at 0.5 mA and 3 mA, in accordance with two designs) lasting 20 seconds. The centre of foot pressure displacement velocities were compared between the two groups. The main results indicate that the regular practice of sports activities counteracts postural control disruption caused by GVS. The active group demonstrated better postural control than the non-active group when subjected to higher vestibular manipulation. The active group may have developed their ability to reduce the influence of inaccurate vestibular signals. The active participants could identify the relevant sensory input, thought a better central integration, which enables them to switch faster between sensory inputs. PMID:27627441

  4. UAS-NAS Stakeholder Feedback Report

    NASA Technical Reports Server (NTRS)

    Randall, Debra; Murphy, Jim; Grindle, Laurie

    2016-01-01

    The need to fly UAS in the NAS to perform missions of vital importance to national security and defense, emergency management, science, and to enable commercial applications has been continually increasing over the past few years. To address this need, the NASA Aeronautics Research Mission Directorate (ARMD) Integrated Aviation Systems Program (IASP) formulated and funded the Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) Project (hereafter referred to as UAS-NAS Project) from 2011 to 2016. The UAS-NAS Project identified the following need statement: The UAS community needs routine access to the global airspace for all classes of UAS. The Project identified the following goal: To provide research findings to reduce technical barriers associated with integrating UAS into the NAS utilizing integrated system level tests in a relevant environment. This report provides a summary of the collaborations between the UAS-NAS Project and its primary stakeholders and how the Project applied and incorporated the feedback.

  5. 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.

  6. 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.

  7. 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

  8. Vestibular-Related Frontal Cortical Areas and Their Roles in Smooth-Pursuit Eye Movements: Representation of Neck Velocity, Neck-Vestibular Interactions, and Memory-Based Smooth-Pursuit

    PubMed Central

    Fukushima, Kikuro; Fukushima, Junko; Warabi, Tateo

    2011-01-01

    Smooth-pursuit eye movements are voluntary responses to small slow-moving objects in the fronto-parallel plane. They evolved in primates, who possess high-acuity foveae, to ensure clear vision about the moving target. The primate frontal cortex contains two smooth-pursuit related areas; the caudal part of the frontal eye fields (FEF) and the supplementary eye fields (SEF). Both areas receive vestibular inputs. We review functional differences between the two areas in smooth-pursuit. Most FEF pursuit neurons signal pursuit parameters such as eye velocity and gaze-velocity, and are involved in canceling the vestibulo-ocular reflex by linear addition of vestibular and smooth-pursuit responses. In contrast, gaze-velocity signals are rarely represented in the SEF. Most FEF pursuit neurons receive neck velocity inputs, while discharge modulation during pursuit and trunk-on-head rotation adds linearly. Linear addition also occurs between neck velocity responses and vestibular responses during head-on-trunk rotation in a task-dependent manner. During cross-axis pursuit–vestibular interactions, vestibular signals effectively initiate predictive pursuit eye movements. Most FEF pursuit neurons discharge during the interaction training after the onset of pursuit eye velocity, making their involvement unlikely in the initial stages of generating predictive pursuit. Comparison of representative signals in the two areas and the results of chemical inactivation during a memory-based smooth-pursuit task indicate they have different roles; the SEF plans smooth-pursuit including working memory of motion–direction, whereas the caudal FEF generates motor commands for pursuit eye movements. Patients with idiopathic Parkinson’s disease were asked to perform this task, since impaired smooth-pursuit and visual working memory deficit during cognitive tasks have been reported in most patients. Preliminary results suggested specific roles of the basal ganglia in memory-based smooth

  9. Stimulus Characteristics for Vestibular Stochastic Resonance to Improve Balance Function

    NASA Technical Reports Server (NTRS)

    Mulavara, Ajitkumar; Fiedler, Matthew; Kofman, Igor; Peters, Brian; Wood, Scott; Serrado, Jorge; Cohen, Helen; Reschke, Millard; Bloomberg, Jacob

    2010-01-01

    Stochastic resonance (SR) is a mechanism by which noise can enhance the response of neural systems to relevant sensory signals. Studies have shown that imperceptible stochastic vestibular electrical stimulation, when applied to normal young and elderly subjects, significantly improved their ocular stabilization reflexes in response to whole-body tilt as well as balance performance during postural disturbances. The goal of this study was to optimize the amplitude characteristics of the stochastic vestibular signals for balance performance during standing on an unstable surface. Subjects performed a standard balance task of standing on a block of foam with their eyes closed. Bipolar stochastic electrical stimulation was applied to the vestibular system using constant current stimulation through electrodes placed over the mastoid process behind the ears. Amplitude of the signals varied in the range of 0-700 microamperes. Balance performance was measured using a force plate under the foam block, and inertial motion sensors were placed on the torso and head. Balance performance with stimulation was significantly greater (10%-25%) than with no stimulation. The signal amplitude at which performance was maximized was in the range of 100-300 microamperes. Optimization of the amplitude of the stochastic signals for maximizing balance performance will have a significant impact on development of vestibular SR as a unique system to aid recovery of function in astronauts after long-duration space flight or in patients with balance disorders.

  10. Relationships Between Vestibular Measures as Potential Predictors for Spaceflight Sensorimotor Adaptation

    NASA Technical Reports Server (NTRS)

    Clark, T. K.; Peters, B.; Gadd, N. E.; De Dios, Y. E.; Wood, S.; Bloomberg, J. J.; Mulavara, A. P.

    2016-01-01

    Introduction: During space exploration missions astronauts are exposed to a series of novel sensorimotor environments, requiring sensorimotor adaptation. Until adaptation is complete, sensorimotor decrements occur, affecting critical tasks such as piloted landing or docking. Of particularly interest are locomotion tasks such as emergency vehicle egress or extra-vehicular activity. While nearly all astronauts eventually adapt sufficiently, it appears there are substantial individual differences in how quickly and effectively this adaptation occurs. These individual differences in capacity for sensorimotor adaptation are poorly understood. Broadly, we aim to identify measures that may serve as pre-flight predictors of and individual's adaptation capacity to spaceflight-induced sensorimotor changes. As a first step, since spaceflight is thought to involve a reinterpretation of graviceptor cues (e.g. otolith cues from the vestibular system) we investigate the relationships between various measures of vestibular function in humans. Methods: In a set of 15 ground-based control subjects, we quantified individual differences in vestibular function using three measures: 1) ocular vestibular evoked myogenic potential (oVEMP), 2) computerized dynamic posturography and 3) vestibular perceptual thresholds. oVEMP responses are elicited using a mechanical stimuli approach. Computerized dynamic posturography was used to quantify Sensory Organization Tests (SOTs), including SOT5M which involved performing pitching head movements while balancing on a sway-reference support surface with eyes closed. We implemented a vestibular perceptual threshold task using the tilt capabilities of the Tilt-Translation Sled (TTS) at JSC. On each trial, the subject was passively roll-tilted left ear down or right ear down in the dark and verbally provided a forced-choice response regarding which direction they felt tilted. The motion profile was a single-cycle sinusoid of angular acceleration with a

  11. 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.

  12. Immunological Influences on the Vestibular System

    NASA Technical Reports Server (NTRS)

    Warchol, Mark E.

    2003-01-01

    The goals of this project were to examine the influence of immune signaling molecules on the survival and replacement of sensory hair cells in the vestibular organs. We have made considerable progress toward that goal, particularly in the characterization of mechanisms that underlie hair cell death.

  13. Vestibular rehabilitation using video gaming in adults with dizziness: a pilot study.

    PubMed

    Phillips, J S; Fitzgerald, J; Phillis, D; Underwood, A; Nunney, I; Bath, A

    2018-03-01

    To determine the effectiveness of vestibular rehabilitation using the Wii Fit balance platform, in adults with dizziness. A single-site prospective clinical trial was conducted in a university hospital in the UK. Forty patients with dizziness, who would normally be candidates for vestibular rehabilitation, were identified and considered as potential participants. Participants were randomised into either the treatment group (the Wii Fit group) or the control group (standard customised vestibular rehabilitation protocol). Participants were assessed over a 16-week period using several balance and quality of life questionnaires. Both exercise regimes resulted in a reduction of dizziness and an improvement in quality of life scores over time, but no statistically significant difference between the two interventions was identified. This pilot study demonstrated that use of the Wii Fit balance platform resulted in a statistically significant improvement in balance function and quality of life. Furthermore, outcomes were comparable to a similar group of individuals following a standard customised vestibular rehabilitation protocol. The study provides useful information to inform the design and execution of a larger clinical trial.

  14. The effects of vestibular stimulation and fatigue on postural control in classical ballet dancers.

    PubMed

    Hopper, Diana M; Grisbrook, Tiffany L; Newnham, Prudence J; Edwards, Dylan J

    2014-01-01

    This study aimed to investigate the effects of ballet-specific vestibular stimulation and fatigue on static postural control in ballet dancers and to establish whether these effects differ across varying levels of ballet training. Dancers were divided into three groups: professional, pre-professional, and recreational. Static postural control of 23 dancers was measured on a force platform at baseline and then immediately, 30 seconds, and 60 seconds after vestibular stimulation (pirouettes) and induction of fatigue (repetitive jumps). The professional dancers' balance was unaffected by both the vestibular stimulation and the fatigue task. The pre-professional and recreational dancers' static sway increased following both perturbations. It is concluded that professional dancers are able to compensate for vestibular and fatiguing perturbations due to a higher level of skill-specific motor training.

  15. Vestibular-ocular accommodation reflex in man.

    PubMed

    Clark, B R; Randle, R J; Stewart, J D

    1975-11-01

    Stimulation of the vestibular system by angular acceleration produces widespread sensory and motor effects. The present study was designed to study a motor effect which has not been reported in the literature, i.e., the influence of rotary acceleration of the body on ocular accommodation. The accommodation of 10 young men was recorded before and after a high-level deceleration to zero velocity following 30 s of rotation. Accommodation was recorded continuously on an infrared optometer for 110 s under two conditions; while the subjects observed a target set at the far point, and while they viewed the same target through a 0.3-mm pinhole. Stimulation by high-level rotary deceleration produced positive accommodation or a pseudomyopia under both conditions, but the positive accommodation was substantially greater and lasted much longer during fixation through the pinhole. It is hypothesized that this increase in accommodation is a result of a vestibular-ocular accommodation reflex.

  16. Management of mal de debarquement syndrome as vestibular migraines.

    PubMed

    Ghavami, Yaser; Haidar, Yarah M; Ziai, Kasra N; Moshtaghi, Omid; Bhatt, Jay; Lin, Harrison W; Djalilian, Hamid R

    2017-07-01

    Mal de debarquement syndrome (MdDS) is a balance disorder that typically starts after an extended exposure to passive motion, such as a boat or plane ride. Management is typically supportive (e.g. physical therapy), and symptoms that persist beyond 6 months have been described as unlikely to remit. This study was conducted to evaluate the response of patients with MdDS to management with migraine prophylaxis, including lifestyle changes and medical therapy. Prospective review. Ambulatory setting at a tertiary care medical center. Clinical history, detailed questionnaires, and audiograms were used to diagnose patients with MdDS. Those patients with the diagnosis of the MdDS were placed on our institutional vestibular migraine management protocol. Treatment response was assessed with a quality-of-life (QOL) survey and visual analog scale. Fifteen patients were diagnosed with MdDS, with a predominance of females (73%) and a mean age of 50 ± 13 years. Eleven patients (73%) responded well to management with a vestibular migraine protocol, which included lifestyle changes, as well as pharmacotherapy with verapamil, nortriptyline, topiramate, or a combination thereof. In comparison, a retrospective control group of 17 patients demonstrated a lower rate of improvement when treated with vestibular rehabilitation and physical therapy. Management of MdDS as vestibular migraine can improve patients' symptoms and increase the QOL. Nearly all the patients suffering from MdDS had a personal or family history of migraine headaches or had signs or symptoms suggestive of atypical migraine. 4 Laryngoscope, 127:1670-1675, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  17. Assessment and Treatment of Blast-Induced Auditory and Vestibular Injuries

    DTIC Science & Technology

    2016-06-01

    Year 2: Q 1 – 2. Examine cochlear and vestibular tissue at 1d and 7d after bTBI Q 3 – 4. Examine cochlear and vestibular tissue at 30d and 60d...the key features of blast wave flow conditions, including the negative phase and secondary shock. However the ABS has not been previously utilized to...isoflurane can be easily adjusted by the flow control. However, due to movement artefact and nosecone constraints, it is a sub-optimal anesthetic

  18. 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.

  19. 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.

  20. Vestibular Activation Differentially Modulates Human Early Visual Cortex and V5/MT Excitability and Response Entropy

    PubMed Central

    Guzman-Lopez, Jessica; Arshad, Qadeer; Schultz, Simon R; Walsh, Vincent; Yousif, Nada

    2013-01-01

    Head movement imposes the additional burdens on the visual system of maintaining visual acuity and determining the origin of retinal image motion (i.e., self-motion vs. object-motion). Although maintaining visual acuity during self-motion is effected by minimizing retinal slip via the brainstem vestibular-ocular reflex, higher order visuovestibular mechanisms also contribute. Disambiguating self-motion versus object-motion also invokes higher order mechanisms, and a cortical visuovestibular reciprocal antagonism is propounded. Hence, one prediction is of a vestibular modulation of visual cortical excitability and indirect measures have variously suggested none, focal or global effects of activation or suppression in human visual cortex. Using transcranial magnetic stimulation-induced phosphenes to probe cortical excitability, we observed decreased V5/MT excitability versus increased early visual cortex (EVC) excitability, during vestibular activation. In order to exclude nonspecific effects (e.g., arousal) on cortical excitability, response specificity was assessed using information theory, specifically response entropy. Vestibular activation significantly modulated phosphene response entropy for V5/MT but not EVC, implying a specific vestibular effect on V5/MT responses. This is the first demonstration that vestibular activation modulates human visual cortex excitability. Furthermore, using information theory, not previously used in phosphene response analysis, we could distinguish between a specific vestibular modulation of V5/MT excitability from a nonspecific effect at EVC. PMID:22291031

  1. Enhancing vestibular function in the elderly with imperceptible electrical stimulation.

    PubMed

    Serrador, Jorge M; Deegan, Brian M; Geraghty, Maria C; Wood, Scott J

    2018-01-10

    Age-related loss of vestibular function can result in decrements in gaze stabilization and increased fall risk in the elderly. This study was designed to see if low levels of electrical stochastic noise applied transcutaneously to the vestibular system can improve a gaze stabilization reflex in young and elderly subject groups. Ocular counter-rolling (OCR) using a video-based technique was obtained in 16 subjects during low frequency passive roll tilts. Consistent with previous studies, there was a significant reduction in OCR gains in the elderly compared to the young group. Imperceptible stochastic noise significantly increased OCR in the elderly (Mean 23%, CI: 17-35%). Increases in OCR gain were greatest for those with lowest baseline gain and were negligible in those with normal gain. Since stimulation was effective at low levels undetectable to subjects, stochastic noise may provide a new treatment alternative to enhance vestibular function, specifically otolith-ocular reflexes, in the elderly or patient populations with reduced otolith-ocular function.

  2. 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

  3. Vision can recalibrate the vestibular reafference signal used to re-establish postural equilibrium following a platform perturbation.

    PubMed

    Toth, Adam J; Harris, Laurence R; Zettel, John; Bent, Leah R

    2017-02-01

    Visuo-vestibular recalibration, in which visual information is used to alter the interpretation of vestibular signals, has been shown to influence both oculomotor control and navigation. Here we investigate whether vision can recalibrate the vestibular feedback used during the re-establishment of equilibrium following a perturbation. The perturbation recovery responses of nine participants were examined following exposure to a period of 11 s of galvanic vestibular stimulation (GVS). During GVS in VISION trials, occlusion spectacles provided 4 s of visual information that enabled participants to correct for the GVS-induced tilt and associate this asymmetric vestibular signal with a visually provided 'upright'. NoVISION trials had no such visual experience. Participants used the visual information to assist in realigning their posture compared to when visual information was not provided (p < 0.01). The initial recovery response to a platform perturbation was not impacted by whether vision had been provided during the preceding GVS, as determined by peak centre of mass and pressure deviations (p = 0.09). However, after using vision to reinterpret the vestibular signal during GVS, final centre of mass and pressure equilibrium positions were significantly shifted compared to trials in which vision was not available (p < 0.01). These findings support previous work identifying a prominent role of vestibular input for re-establishing postural equilibrium following a perturbation. Our work is the first to highlight the capacity for visual feedback to recalibrate the vertical interpretation of vestibular reafference for re-establishing equilibrium following a perturbation. This demonstrates the rapid adaptability of the vestibular reafference signal for postural control.

  4. 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.

  5. 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.

  6. A simple model for the generation of the vestibular evoked myogenic potential (VEMP).

    PubMed

    Wit, Hero P; Kingma, Charlotte M

    2006-06-01

    To describe the mechanism by which the vestibular evoked myogenic potential is generated. Vestibular evoked myogenic potential generation is modeled by adding a large number of muscle motor unit action potentials. These action potentials occur randomly in time along a 100 ms long time axis. But because between approximately 15 and 20 ms after a loud short sound stimulus (almost) no action potentials are generated during VEMP measurements in human subjects, no action potentials are present in the model during this time. The evoked potential is the result of the lack of amplitude cancellation in the averaged surface electromyogram at the edges of this 5 ms long time interval. The relatively simple model describes generation and some properties of the vestibular evoked myogenic potential very well. It is shown that, in contrast with other evoked potentials (BAEPs, VERs), the vestibular evoked myogenic potential is the result of an interruption of activity and not that of summed synchronized neural action potentials.

  7. 3D hybrid electrode structure as implantable interface for a vestibular neural prosthesis in humans.

    PubMed

    Hoffmann, Klaus-P; Poppendieck, Wigand; Tätzner, Simon; DiGiovanna, Jack; Kos, Maria Izabel; Guinand, Nils; Guyot, Jean-P; Micera, Silvestro

    2011-01-01

    Implantable interfaces are essential components of vestibular neural prostheses. They interface the biological system with electrical stimulation that is used to restore transfer of vestibular information. Regarding the anatomical situation special 3D structures are required. In this paper, the design and the manufacturing process of a novel 3D hybrid microelectrode structure as interface to the human vestibular system are described. Photolithography techniques, assembling technology and rapid prototyping are used for manufacturing.

  8. Vestibulo-cortical Hemispheric Dominance: the link between Anxiety and the Vestibular System?

    PubMed

    Bednarczuk, Nadja F; Casanovas Ortega, Marta; Fluri, Anne-Sophie; Arshad, Qadeer

    2018-05-16

    Vestibular processing and anxiety networks are functionally intertwined, as demonstrated by reports of reciprocal influences upon each other. Yet whether there is an underlying link between these two systems remains unknown Previous findings have highlighted the involvement of hemispheric lateralisation in processing of both anxiety and vestibular signals. Accordingly, we explored the interaction between vestibular cortical processing and anxiety by assessing the relationship between anxiety levels and the degree of hemispheric lateralisation of vestibulo-cortical processing in 64 right-handed, healthy individuals. Vestibulo-cortical hemispheric lateralisation was determined by gaging the degree of caloric-induced nystagmus suppression following modulation of cortical excitability using trans-cranial direct current stimulation targeted over the posterior parietal cortex, an area implicated in the processing of vestibular signals. The degree of nystagmus suppression yields an objective biomarker, allowing the quantification of the degree of right vestibulo-cortical hemisphere dominance. Anxiety levels were quantified using the Trait component of the Spielberger State-Trait Anxiety Questionnaire. Our findings demonstrate that the degree of an individual's vestibulo-cortical hemispheric dominance correlates with their anxiety levels. That is, those individuals with greater right hemispheric vestibulo-cortical dominance exhibited lower levels of anxiety. By extension, our results support the notion that hemispheric lateralisation determines an individual's emotional processing, thereby linking cortical circuits involved in processing anxiety and vestibular signals respectively. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  9. Requirement for Lmo4 in the Vestibular Morphogenesis of Mouse Inner Ear

    PubMed Central

    Deng, Min; Pan, Ling; Xie, Xiaoling; Gan, Lin

    2009-01-01

    During development, compartmentalization of an early embryonic structure produces blocks of cells with distinct properties and developmental potentials. The auditory and vestibular components of vertebrate inner ears are derived from defined compartments within the otocyst during embryogenesis. The vestibular apparatus, including three semicircular canals, saccule, utricle, and their associated sensory organs, detects angular and linear acceleration of the head and relays the information through vestibular neurons to vestibular nuclei in the brainstem. How the early developmental events manifest vestibular structures at the molecular level is largely unknown. Here, we show that LMO4, a LIM-domain-only transcriptional regulator, is required for the formation of semicircular canals and their associated sensory cristae. Targeted disruption of Lmo4 resulted in the dysmorphogenesis of the vestibule and in the absence of three semicircular canals, anterior and posterior cristae. In Lmo4-null otocysts, canal outpouches failed to form and cell proliferation was reduced in the dorsolateral region. Expression analysis of the known otic markers showed that Lmo4 is essential for the normal expression of Bmp4, Fgf10, Msx1, Isl1, Gata3, and Dlx5 in the dorsolateral domain of the otocyst, whereas the initial compartmentalization of the otocyst remains unaffected. Our results demonstrate that Lmo4 controls the development of the dorsolateral otocyst into semicircular canals and cristae through two distinct mechanisms: regulating the expression of otic specific genes and stimulating the proliferation of the dorsolateral part of the otocyst. PMID:19913004

  10. Saccular function in otosclerosis patients: bone conducted-vestibular evoked myogenic potential analysis.

    PubMed

    Amali, Amin; Mahdi, Parvane; Karimi Yazdi, Alireza; Khorsandi Ashtiyani, Mohammad Taghi; Yazdani, Nasrin; Vakili, Varasteh; Pourbakht, Akram

    2014-01-01

    Vestibular involvements have long been observed in otosclerotic patients. Among vestibular structures saccule has the closest anatomical proximity to the sclerotic foci, so it is the most prone vestibular structure to be affected during the otosclerosis process. The aim of this study was to investigate the saccular function in patients suffering from otosclerosis, by means of Vestibular Evoked Myogenic Potential (VEMP). The material consisted of 30 otosclerosis patients and 20 control subjects. All participants underwent audiometric and VEMP testing. Analysis of tests results revealed that the mean values of Air-Conducted Pure Tone Average (AC-PTA) and Bone-Conducted Pure Tone Average (BC-PTA) in patients were 45.28 ± 15.57 and 19.68 ± 10.91, respectively and calculated 4 frequencies Air Bone Gap (ABG) was 25.64 ± 9.95. The VEMP response was absent in 14 (28.57%) otosclerotic ears. A statistically significant increase in latency of the p13 was found in the affected ears (P=0.004), differences in n23 latency did not reach a statistically significant level (P=0.112). Disparities in amplitude of p13-n23 in between two study groups was statistically meaningful (P=0.009), indicating that the patients with otosclerosis had lower amplitudes. This study tends to suggest that due to the direct biotoxic effect of the materials released from the otosclerosis foci on saccular receptors, there might be a possibility of vestibular dysfunction in otosclerotic patients.

  11. Does Otosclerosis Affect Dark and Transitional Cells in the Human Vestibular Labyrinth?

    PubMed

    Kaya, Serdar; Paparella, Michael M; Cureoglu, Sebahattin

    2017-02-01

    The density of vestibular dark cells (DCs) and vestibular transitional cells (TCs) can be quantitatively decreased in human temporal bones with otosclerosis. Previous reports have shown that otosclerosis can lead to vestibular symptoms. We examined 61 human temporal bone specimens from 52 deceased donors with otosclerosis group-with and without endosteal involvement (EI), and with and without endolymphatic hydrops (EH)-versus 25 specimens from 18 age-matched controls. Using light microscopy, we evaluated the nonsensory epithelium of the lateral semicircular canal (LSC) and posterior semicircular canal (PSC) of the human vestibular labyrinth, focusing on the density of DCs and TCs. In both the LSC and the PSC, as compared with the control group, the mean density of DCs significantly decreased in the EI (+) group, in the EI (+) and EH (+) subgroup, and in the EI (+) and EH (-) subgroup (p < 0.05). In addition, we found a significant difference in the mean density of DCs between the EI (+) group and the EI (-) group in the LSC and in the PSC (p < 0.05). But we found no significant difference in the mean density of TCs in any of the otosclerosis groups or subgroups as compared with the control group (p > 0.05). We found a decrease in the density of DCs associated with EI in human temporal bone specimens with otosclerosis, regardless of the presence of EH. This decrease might cause damage in ion and water transportation, leading to vestibular symptoms.

  12. Evidence for vestibular regulation of autonomic functions in a mouse genetic model

    NASA Technical Reports Server (NTRS)

    Murakami, Dean M.; Erkman, Linda; Hermanson, Ola; Rosenfeld, Michael G.; Fuller, Charles A.

    2002-01-01

    Physiological responses to changes in the gravitational field and body position, as well as symptoms of patients with anxiety-related disorders, have indicated an interrelationship between vestibular function and stress responses. However, the relative significance of cochlear and vestibular information in autonomic regulation remains unresolved because of the difficulties in distinguishing the relative contributions of other proprioceptive and interoceptive inputs, including vagal and somatic information. To investigate the role of cochlear and vestibular function in central and physiological responses, we have examined the effects of increased gravity in wild-type mice and mice lacking the POU homeodomain transcription factor Brn-3.1 (Brn-3bPou4f3). The only known phenotype of the Brn-3.1(-/-) mouse is related to hearing and balance functions, owing to the failure of cochlear and vestibular hair cells to differentiate properly. Here, we show that normal physiological responses to increased gravity (2G exposure), such as a dramatic drop in body temperature and concomitant circadian adjustment, were completely absent in Brn-3.1(-/-) mice. In line with the lack of autonomic responses, the massive increase in neuronal activity after 2G exposure normally detected in wild-type mice was virtually abolished in Brn-3.1(-/-) mice. Our results suggest that cochlear and vestibular hair cells are the primary regulators of autonomic responses to altered gravity and provide genetic evidence that these cells are sufficient to alter neural activity in regions involved in autonomic and neuroendocrine control.

  13. Vestibular-dependent inter-stimulus interval effects on sound evoked potentials of central origin.

    PubMed

    Todd, N P M; Govender, S; Colebatch, J G

    2016-11-01

    Todd et al. (2014ab) have recently demonstrated the presence of vestibular-dependent contributions to auditory evoked potentials (AEPs) when passing through the vestibular threshold as determined by vestibular evoked myogenic potentials (VEMPs), including a particular deflection labeled as an N42/P52 prior to the long-latency AEPs N1 and P2. In this paper we report the results of an experiment to determine the effect of inter-stimulus interval (ISI) and regularity on potentials recorded above and below VEMP threshold. Five healthy, right-handed subjects were recruited and evoked potentials were recorded to binaurally presented sound stimulation, above and below vestibular threshold, at seven stimulus rates with ISIs of 212, 300, 424, 600, 848, 1200 and 1696 ms. The inner five intervals, i.e. 300, 424, 600, 848, 1200 ms, were presented twice in both regular and irregular conditions. ANOVA on the global field power (GFP) were conducted for each of four waves, N42, P52, N1 and P2 with factors of intensity, ISI and regularity. Both N42 and P52 waves showed significant ANOVA effects of intensity but no other main effects or interactions. In contrast both N1 and P2 showed additional effects of ISI, as well as intensity, and evidence of non-linear interactions between ISI and intensity. A source analysis was carried out consistent with prior work suggesting that when above vestibular threshold, in addition to bilateral superior temporal cortex, ocular, cerebellar and cingulate sources are recruited. Further statistical analysis of the source currents indicated that the origin of the interactions with intensity may be the ISI sensitivity of the vestibular-dependent sources. This in turn may reflect a specific vestibular preference for stimulus rates associated with locomotion, i.e. rates close to 2 Hz, or ISIs close to 500 ms, where saccular afferents show increased gain and the corresponding reflexes are most sensitive. Copyright © 2016 The Authors. Published by

  14. ACh-induced hyperpolarization and decreased resistance in mammalian type II vestibular hair cells.

    PubMed

    Poppi, Lauren A; Tabatabaee, Hessam; Drury, Hannah R; Jobling, Phillip; Callister, Robert J; Migliaccio, Americo A; Jordan, Paivi M; Holt, Joseph C; Rabbitt, Richard D; Lim, Rebecca; Brichta, Alan M

    2018-01-01

    In the mammalian vestibular periphery, electrical activation of the efferent vestibular system (EVS) has two effects on afferent activity: 1) it increases background afferent discharge and 2) decreases afferent sensitivity to rotational stimuli. Although the cellular mechanisms underlying these two contrasting afferent responses remain obscure, we postulated that the reduction in afferent sensitivity was attributed, in part, to the activation of α9- containing nicotinic acetylcholine (ACh) receptors (α9*nAChRs) and small-conductance potassium channels (SK) in vestibular type II hair cells, as demonstrated in the peripheral vestibular system of other vertebrates. To test this hypothesis, we examined the effects of the predominant EVS neurotransmitter ACh on vestibular type II hair cells from wild-type (wt) and α9-subunit nAChR knockout (α9 -/- ) mice. Immunostaining for choline acetyltransferase revealed there were no obvious gross morphological differences in the peripheral EVS innervation among any of these strains. ACh application onto wt type II hair cells, at resting potentials, produced a fast inward current followed by a slower outward current, resulting in membrane hyperpolarization and decreased membrane resistance. Hyperpolarization and decreased resistance were due to gating of SK channels. Consistent with activation of α9*nAChRs and SK channels, these ACh-sensitive currents were antagonized by the α9*nAChR blocker strychnine and SK blockers apamin and tamapin. Type II hair cells from α9 -/- mice, however, failed to respond to ACh at all. These results confirm the critical importance of α9nAChRs in efferent modulation of mammalian type II vestibular hair cells. Application of exogenous ACh reduces electrical impedance, thereby decreasing type II hair cell sensitivity. NEW & NOTEWORTHY Expression of α9 nicotinic subunit was crucial for fast cholinergic modulation of mammalian vestibular type II hair cells. These findings show a multifaceted

  15. Altered auditory and vestibular functioning in individuals with low bone mineral density: a systematic review.

    PubMed

    Singh, Niraj Kumar; Jha, Raghav Hira; Gargeshwari, Aditi; Kumar, Prawin

    2018-01-01

    Alteration in the process of bone remodelling is associated with falls and fractures due to increased bone fragility and altered calcium functioning. The auditory system consists of skeletal structures and is, therefore, prone to getting affected by altered bone remodelling. In addition, the vestibule consists of huge volumes of calcium (CaCO3) in the form of otoconia crystals and alteration in functioning calcium levels could, therefore, result in vestibular symptoms. Thus, the present study aimed at compiling information from various studies on assessment of auditory or vestibular systems in individuals with reduced bone mineral density (BMD). A total of 1977 articles were searched using various databases and 19 full-length articles which reported auditory and vestibular outcomes in persons with low BMD were reviewed. An intricate relationship between altered BMD and audio-vestibular function was evident from the studies; nonetheless, how one aspect of hearing or balance affects the other is not clear. Significant effect of reduced bone mineral density could probably be due to the metabolic changes at the level of cochlea, secondary to alterations in BMD. One could also conclude that sympathetic remodelling is associated with vestibular problems in individual; however, whether vestibular problems lead to altered BMD cannot be ascertained with confidence. The studies reviewed in the article provide an evidence of possible involvement of hearing and vestibular system abnormalities in individuals with reduced bone mineral density. Hence, the assessment protocol for these individuals must include hearing and balance evaluation as mandatory for planning appropriate management.

  16. Distribution of zebrin-immunoreactive Purkinje cell terminals in the cerebellar and vestibular nuclei of birds.

    PubMed

    Wylie, Douglas R; Pakan, Janelle M P; Huynh, Hang; Graham, David J; Iwaniuk, Andrew N

    2012-05-01

    Zebrin II (aldolase C) is expressed in a subset of Purkinje cells in the mammalian and avian cerebella such that there is a characteristic parasagittal organization of zebrin-immunopositive stripes alternating with zebrin-immunonegative stripes. Zebrin is expressed not only in the soma and dendrites of Purkinje cells but also in their axonal terminals. Here we describe the distribution of zebrin immunoreactivity in both the vestibular and the cerebellar nuclei of pigeons (Columba livia) and hummingbirds (Calypte anna, Selasphorus rufus). In the medial cerebellar nucleus, zebrin-positive labeling was particularly heavy in the “shell,” whereas the “core” was zebrin negative. In the lateral cerebellar nucleus, labeling was not as heavy, but a positive shell and negative core were also observed. In the vestibular nuclear complex, zebrin-positive terminal labeling was heavy in the dorsolateral vestibular nucleus and the lateral margin of the superior vestibular nucleus. The central and medial regions of the superior nucleus were generally zebrin negative. Labeling was moderate to heavy in the medial vestibular nucleus, particulary the rostral half of the parvocellular subnucleus. A moderate amount of zebrin-positive labeling was present in the descending vestibular nucleus: this was heaviest laterally, and the central region was generally zebrin negative. Zebrin-positive terminals were also observed in the the cerebellovestibular process, prepositus hypoglossi, and lateral tangential nucleus. We discuss our findings in light of similar studies in rats and with respect to the corticonuclear projections to the cerebellar nuclei and the functional connections of the vestibulocerebellum with the vestibular nuclei. Copyright © 2011 Wiley Periodicals, Inc.

  17. Disorders of balance and vestibular function in US adults: data from the National Health and Nutrition Examination Survey, 2001-2004.

    PubMed

    Agrawal, Yuri; Carey, John P; Della Santina, Charles C; Schubert, Michael C; Minor, Lloyd B

    2009-05-25

    Balance dysfunction can be debilitating and can lead to catastrophic outcomes such as falls. The inner ear vestibular system is an important contributor to balance control. However, to our knowledge, the prevalence of vestibular dysfunction in the United States and the magnitude of the increased risk of falling associated with vestibular dysfunction have never been estimated. The objective of this study was to determine the prevalence of vestibular dysfunction among US adults, evaluate differences by sociodemographic characteristics, and estimate the association between vestibular dysfunction and risk of falls. We included data from the 2001-2004 National Health and Nutrition Examination Surveys, which were cross-sectional surveys of US adults aged 40 years and older (n = 5086). The main outcome measure was vestibular function as measured by the modified Romberg Test of Standing Balance on Firm and Compliant Support Surfaces. From 2001 through 2004, 35.4% of US adults aged 40 years and older (69 million Americans) had vestibular dysfunction. Odds of vestibular dysfunction increased significantly with age, were 40.3% lower in individuals with more than a high school education, and were 70.0% higher among people with diabetes mellitus. Participants with vestibular dysfunction who were clinically symptomatic (ie, reported dizziness) had a 12-fold increase in the odds of falling. Vestibular dysfunction, as measured by a simple postural metric, is common among US adults. Vestibular dysfunction significantly increases the likelihood of falls, which are among the most morbid and costly health conditions affecting older individuals. These data suggest the importance of diagnosing, treating, and potentially screening for vestibular deficits to reduce the burden of fall-related injuries and deaths in the United States.

  18. Disability rank in vestibular older adults.

    PubMed

    Aratani, Mayra Cristina; Perracini, Monica Rodrigues; Caovilla, Heloísa Helena; Gazzola, Juliana Maria; Ganança, Mauricio Malavasi; Ganança, Fernando Freitas

    2011-01-01

    To analyze the hierarchical structure of activities of daily living (ADL) among vestibular older adults, according to its power to discriminate disability. An exploratory cross-sectional study was conducted comprising 235 elderly, aged 65 years and older, with chronic vestibular dysfunction. Functional capacity was assessed through the Brazilian version of OARS Multidimensional Functional Assessment Questionnaire which consists of 15 activities of daily living (ADL). The sample was classified in each ADL according to the difficulty level in performing the activity. A multiple correlation analysis technique and discriminant analysis was used to analyze the hierarchical structure of ADL. The sample consisted of 75.3% women, with an average age of 73.55±5.94 years. The ADL and their respective discrimination measurements were: getting into and out of bed (0.293); eating (0.129); combing hair (0.150); walking on flat surfaces (0.270); having a bath/shower (0.512); getting dressed (0.325); getting to the toilet in time (0.107); climbing stairs (0.338); taking medicines on time (0.035); walking close to home (0.529); shopping (0.503); preparing meals (0.398); cutting toenails (0.242); getting off buses (0.452); and cleaning the house (0.408). The tasks that reflect a higher demand upon the vestibular system were the most impaired, in the following order: walking close to home, having a bath/shower, shopping, getting off buses, cleaning the house, preparing meals, climbing stairs, getting dressed, getting into and out of bed, walking on flat surfaces, cutting toenails, combing hair, eating, getting to the toilet in time, taking medicines on time. © 2010 Japan Geriatrics Society.

  19. Vestibular Dysfunction after Subconcussive Head Impact

    PubMed Central

    Ma, Lei; Kawata, Keisuke; Tierney, Ryan; Jeka, John J.

    2017-01-01

    Abstract Current thinking views mild head impact (i.e., subconcussion) as an underrecognized phenomenon that has the ability to cause significant current and future detrimental neurological effects. Repeated mild impacts to the head, however, often display no observable behavioral deficits based on standard clinical tests, which may lack sensitivity. The current study investigates the effects of subconcussive impacts from soccer heading with innovative measures of vestibular function and walking stability in a pre- 0–2 h, post- 24 h post-heading repeated measures design. The heading group (n = 10) executed 10 headers with soccer balls projected at a velocity of 25 mph (11.2 m/sec) over 10 min. Subjects were evaluated 24 h before, immediately after, and 24 h after soccer heading with: the modified Balance Error Scoring System (mBESS); a walking stability task with visual feedback of trunk movement; and galvanic vestibular stimulation (GVS) while standing with eyes closed on foam. A control group (n = 10) followed the same protocol with no heading. The results showed significant decrease in trunk angle, leg angle gain, and center of mass gain relative to GVS for the heading group compared with controls. Medial-lateral trunk orientation displacement and velocity during treadmill walking increased immediately after mild head impact for the heading group compared with controls. Controls showed an improvement in mBESS scores over time, indicating a learning effect, which was not observed with the heading group. These results suggest that mild head impact leads to a transient dysfunction in vestibular processing, which deters walking stability during task performance. PMID:26885560

  20. Vestibular Dysfunction after Subconcussive Head Impact.

    PubMed

    Hwang, Sungjae; Ma, Lei; Kawata, Keisuke; Tierney, Ryan; Jeka, John J

    2017-01-01

    Current thinking views mild head impact (i.e., subconcussion) as an underrecognized phenomenon that has the ability to cause significant current and future detrimental neurological effects. Repeated mild impacts to the head, however, often display no observable behavioral deficits based on standard clinical tests, which may lack sensitivity. The current study investigates the effects of subconcussive impacts from soccer heading with innovative measures of vestibular function and walking stability in a pre- 0-2 h, post- 24 h post-heading repeated measures design. The heading group (n = 10) executed 10 headers with soccer balls projected at a velocity of 25 mph (11.2 m/sec) over 10 min. Subjects were evaluated 24 h before, immediately after, and 24 h after soccer heading with: the modified Balance Error Scoring System (mBESS); a walking stability task with visual feedback of trunk movement; and galvanic vestibular stimulation (GVS) while standing with eyes closed on foam. A control group (n = 10) followed the same protocol with no heading. The results showed significant decrease in trunk angle, leg angle gain, and center of mass gain relative to GVS for the heading group compared with controls. Medial-lateral trunk orientation displacement and velocity during treadmill walking increased immediately after mild head impact for the heading group compared with controls. Controls showed an improvement in mBESS scores over time, indicating a learning effect, which was not observed with the heading group. These results suggest that mild head impact leads to a transient dysfunction in vestibular processing, which deters walking stability during task performance.

  1. Physical and sporting activities improve vestibular afferent usage and balance in elderly human subjects.

    PubMed

    Gauchard, G C; Jeandel, C; Perrin, P P

    2001-01-01

    Ageing is associated with a reduction in balance, in particular through dysfunction of each level of postural control, which results in an increased risk of falling. Conversely, the practice of physical activities has been shown to modulate postural control in elderly people. This study examined the potential positive effects of two types of regular physical and sporting activities on vestibular information and their relation to posture. Gaze and postural stabilisation was evaluated by caloric and rotational vestibular tests on 18 healthy subjects over the age of 60 who regularly practised low-energy or bioenergetic physical activities and on 18 controls of a similar age who only walked on a regular basis. These subjects were also submitted to static and dynamic posturographic tests. The control group displayed less balance control, with a lower vestibular sensitivity and a relatively high dependency on vision compared to the group practising low-energy physical activities, which had better postural control with good vestibular sensitivity and less dependency on vision. The postural control and vestibular sensitivity of subjects practising bioenergetic activities was average, and required higher visual afferent contribution. Low-energy exercises, already shown to have the most positive impact on balance control by relying more on proprioception, also appear to develop or maintain a high level of vestibular sensitivity allowing elderly people practising such exercises to reduce the weight of vision. Copyright 2001 S. Karger AG, Basel

  2. 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

  3. 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.

  4. Influence of combined visual and vestibular cues on human perception and control of horizontal rotation

    NASA Technical Reports Server (NTRS)

    Zacharias, G. L.; Young, L. R.

    1981-01-01

    Measurements are made of manual control performance in the closed-loop task of nulling perceived self-rotation velocity about an earth-vertical axis. Self-velocity estimation is modeled as a function of the simultaneous presentation of vestibular and peripheral visual field motion cues. Based on measured low-frequency operator behavior in three visual field environments, a parallel channel linear model is proposed which has separate visual and vestibular pathways summing in a complementary manner. A dual-input describing function analysis supports the complementary model; vestibular cues dominate sensation at higher frequencies. The describing function model is extended by the proposal of a nonlinear cue conflict model, in which cue weighting depends on the level of agreement between visual and vestibular cues.

  5. Sensitivity of caloric test and video head impulse as screening test for chronic vestibular complaints.

    PubMed

    Mezzalira, Raquel; Bittar, Roseli Saraiva Moreira; do Carmo Bilécki-Stipsky, Marcia Maria; Brugnera, Cibele; Grasel, Signe Schuster

    2017-08-01

    This study compared the results of the caloric test with those of the video head impulse test obtained during the same session and evaluated whether the former can be used to screen for non-acute vestibular dysfunction. A total of 157 participants complaining of dizziness with vestibular characteristics of varying durations and clinical courses completed the caloric test and video head impulse test. Significantly more caloric test results than video head impulse test results were abnormal. The results of the caloric test and video head impulse test are distinct but complement each other. Within our sample, the caloric test was more sensitive for vestibular dysfunction. Therefore, the video head impulse test is not a suitable screening tool of the vestibular system in patients with chronic complaints.

  6. Improving Sensorimotor Adaptation Following Long Duration Space Flight by Enhancing Vestibular Information Transfer

    NASA Technical Reports Server (NTRS)

    Mulavara, A. P.; Kofman, I. S.; De Dios, Y. E; Galvan, R.; Goel, R.; Miller, C.; Peters, B.; Cohen, H. S.; Jeevarajan, J.; Reschke, M.; hide

    2014-01-01

    Crewmember adapted to the microgravity state may need to egress the vehicle within a few minutes for safety and operational reasons after gravitational transitions. The transition from one sensorimotor state to another consists of two main mechanisms: strategic and plastic-adaptive and have been demonstrated in astronauts returning after long duration space flight. Strategic modifications represent "early adaptation" - immediate and transitory changes in control that are employed to deal with short-term changes in the environment. If these modifications are prolonged then plastic-adaptive changes are evoked that modify central nervous system function, automating new behavioral responses. More importantly, this longer term adaptive recovery mechanism was significantly associated with their strategic ability to recover on the first day after return to Earth G. We are developing a method based on stochastic resonance to enhance information transfer by improving the brain's ability to detect vestibular signals (Vestibular Stochastic Resonance, VSR) especially when combined with balance training exercises such as sensorimotor adaptability (SA) training for rapid improvement in functional skill, for standing and mobility. This countermeasure to improve detection of vestibular signals is a stimulus delivery system that is wearable/portable providing low imperceptible levels of white noise based binaural bipolar electrical stimulation of the vestibular system (stochastic vestibular stimulation). To determine efficacy of vestibular stimulation on physiological and perceptual responses during otolith-canal conflicts and dynamic perturbations we have conducted a series of studies: We have shown that imperceptible binaural bipolar electrical stimulation of the vestibular system across the mastoids enhances balance performance in the mediolateral (ML) plane while standing on an unstable surface. We have followed up on the previous study showing VSR stimulation improved balance

  7. 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.

  8. Estimation of an Optimal Stimulus Amplitude for Using Vestibular Stochastic Stimulation to Improve Balance Function

    NASA Technical Reports Server (NTRS)

    Goel, R.; Kofman, I.; DeDios, Y. E.; Jeevarajan, J.; Stepanyan, V.; Nair, M.; Congdon, S.; Fregia, M.; Peters, B.; Cohen, H.; hide

    2015-01-01

    Sensorimotor changes such as postural and gait instabilities can affect the functional performance of astronauts when they transition across different gravity environments. We are developing a method, based on stochastic resonance (SR), to enhance information transfer by applying non-zero levels of external noise on the vestibular system (vestibular stochastic resonance, VSR). The goal of this project was to determine optimal levels of stimulation for SR applications by using a defined vestibular threshold of motion detection.

  9. Dizziness: relating the severity of vertigo to the degree of handicap by measuring vestibular impairment.

    PubMed

    Pérez, Nicolás; Martin, Eduardo; Garcia-Tapia, Rafael

    2003-03-01

    We sought to correlate the severity of vertigo and handicap in patients with vestibular pathology according to measures of impairment. We conducted a prospective assessment of patients with dizziness by means of caloric, rotatory test, and computerized dynamic posturography to estimate impairment. Handicap and severity of vertigo were determined with specific questionnaires (Dizziness Handicap Inventory and UCLA-DQ). A fair relationship were found between severity of dizziness and vestibular handicap. When impairment was taken into consideration, values were still fair and only moderate for a group of patients with an abnormal caloric test as the only pathologic finding. The composite score from the sensory organization test portion of the computerized dynamic posturography is fairly correlated to severity of vertigo and handicap in the whole population of patients, but no correlation was found when they were assigned to groups of vestibular impairment. To assess vestibular impairment, the results from several tests must be taken into account. However, vestibular handicap is not solely explained with measurements of impairment and/or severity.

  10. 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.

  11. Vestibular Function Measurement Devices

    PubMed Central

    Miles, Richard D.; Zapala, David A.

    2015-01-01

    Vestibular function laboratories utilize a multitude of diagnostic instruments to evaluate a dizzy patient. Caloric irrigators, oculomotor stimuli, and rotational chairs produce a stimulus whose accuracy is required for the patient response to be accurate. Careful attention to everything from cleanliness of equipment to threshold adjustments determine on a daily basis if patient data are going to be correct and useful. Instrumentation specifications that change with time such as speed and temperature must periodically be checked using calibrated instruments. PMID:27516710

  12. 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

  13. The art of perception: Patients drawing their vestibular schwannoma.

    PubMed

    van Leeuwen, Bibian M; Herruer, Jasmijn M; Putter, Hein; van der Mey, Andel G L; Kaptein, Adrian A

    2015-12-01

    Drawings made by patients are an innovative way to assess the perceptions of patients on their illness. The objective of this study, at a university tertiary referral center, on patients who have recently been diagnosed with vestibular schwannoma, was to examine whether patients' illness perceptions can be assessed by drawings and are related to their quality of life. Cross-sectional study. Patients diagnosed with vestibular schwannoma (mean age [range], 55.4 [17-85] years) between April 2011 and October 2012 were included (N = 253). Sociodemographics, illness perceptions (Brief Illness Perception Questionnaire [B-IPQ]), and disease-specific quality of life (Penn Acoustic Neuroma Quality of Life [PANQOL] scale) were assessed to evaluate the impact of being diagnosed with vestibular schwannoma. Furthermore, patients' drawings of their tumor were analyzed to explore the association between illness perceptions, drawings, and quality of life. Comparison of the B-IPQ scores of the current sample (N = 139; response rate 54.9%) with other disease samples shows a significantly lower score for patients with vestibular schwannoma on the Coherence dimension, indicating a low understanding of the illness. Illustration of emotions (N = 12) in the drawings gave a negative association with quality of life. Intercorrelations indicate a positive association between a low amount of physical and emotional consequences of the illness and a higher score on the Balance, Hearing, and Energy dimensions of the PANQOL. Patients' drawings give an insight into their perception of the tumor inside their head. Use of drawings may be helpful when developing and offering self-management programs. Quality of life appears to be significantly affected by the diagnosis. 4. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

  14. Inertial vestibular coding of motion: concepts and evidence

    NASA Technical Reports Server (NTRS)

    Hess, B. J.; Angelaki, D. E.

    1997-01-01

    Central processing of inertial sensory information about head attitude and motion in space is crucial for motor control. Vestibular signals are coded relative to a non-inertial system, the head, that is virtually continuously in motion. Evidence for transformation of vestibular signals from head-fixed sensory coordinates to gravity-centered coordinates have been provided by studies of the vestibulo-ocular reflex. The underlying central processing depends on otolith afferent information that needs to be resolved in terms of head translation related inertial forces and head attitude dependent pull of gravity. Theoretical solutions have been suggested, but experimental evidence is still scarce. It appears, along these lines, that gaze control systems are intimately linked to motor control of head attitude and posture.

  15. Development of vestibular afferent projections into the hindbrain and their central targets

    NASA Technical Reports Server (NTRS)

    Maklad, Adel; Fritzsch, Bernd

    2003-01-01

    In contrast to most other sensory systems, hardly anything is known about the neuroanatomical development of central projections of primary vestibular neurons and how their second order target neurons develop. Recent data suggest that afferent projections may develop not unlike other sensory systems, forming first the overall projection by molecular means followed by an as yet unspecified phase of activity mediated refinement. The latter aspect has not been tested critically and most molecules that guide the initial projection are unknown.The molecular and topological origin of the vestibular and cochlear nucleus neurons is also only partially understood. Auditory and vestibular nuclei form from several rhombomeres and a given rhombomere can contribute to two or more auditory or vestibular nuclei. Rhombomere compartments develop as functional subdivisions from a single column that extends from the hindbrain to the spinal cord. Suggestions are provided for the molecular origin of these columns but data on specific mutants testing these proposals are not yet available. Overall, the functional significance of both overlapping and segregated projections are not yet fully experimentally explored in mammals. Such lack of details of the adult organization compromises future developmental analysis.

  16. Vesibulotoxicity and Management of Vestibular Disorders

    ERIC Educational Resources Information Center

    Carey, John P.

    2005-01-01

    The toxicity of certain aminoglycoside antibiotics for vestibular hair cells has been used to special advantage in the treatment of Meniere's disease. Intratympanic (middle ear) injections of these drugs are being increasingly used to control vertigo in this disorder when it has not responded to medical therapy. The mechanisms by which these drugs…

  17. 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.

  18. Vestibular migraine: the most frequent entity of episodic vertigo.

    PubMed

    Dieterich, Marianne; Obermann, Mark; Celebisoy, Nese

    2016-04-01

    Vestibular migraine (VM) is the most common cause of episodic vertigo in adults as well as in children. The diagnostic criteria of the consensus document of the International Bárány Society for Neuro-Otology and the International Headache Society (2012) combine the typical signs and symptoms of migraine with the vestibular symptoms lasting 5 min to 72 h and exclusion criteria. Although VM accounts for 7% of patients seen in dizziness clinics and 9% of patients seen in headache clinics it is still underdiagnosed. This review provides an actual overview on the pathophysiology, the clinical characteristics to establish the diagnosis, the differential diagnosis, and the treatment of VM.

  19. Quality of Life in 807 Patients with Vestibular Schwannoma: Comparing Treatment Modalities.

    PubMed

    Soulier, Géke; van Leeuwen, Bibian M; Putter, Hein; Jansen, Jeroen C; Malessy, Martijn J A; van Benthem, Peter Paul G; van der Mey, Andel G L; Stiggelbout, Anne M

    2017-07-01

    Objective In vestibular schwannoma treatment, the choice among treatment modalities is controversial. The first aim of this study was to examine the quality of life of patients with vestibular schwannoma having undergone observation, radiation therapy, or microsurgical resection. The second aim was to examine the relationship between perceived symptoms and quality of life. Last, the association between quality of life and time since treatment was studied. Study Design Cross-sectional study. Setting Tertiary referral center. Subjects and Methods A total of 1208 patients treated for sporadic vestibular schwannoma between 2004 and 2014 were mailed the disease-specific Penn Acoustic Neuroma Quality of Life (PANQOL) questionnaire and additional questions on symptoms associated with vestibular schwannoma. Total and domain scores were calculated and compared among treatment groups. Propensity scores were used, and results were stratified according to tumor size to control for potential confounders. Correlations were calculated to examine the relationship between self-reported symptoms and quality of life, as well as between quality of life and time since treatment. Results Patients with small tumors (≤10 mm) under observation showed a higher PANQOL score when compared with the radiation therapy and microsurgical resection groups. A strong negative correlation was found between self-reported symptoms and quality of life, with balance problems and vertigo having the largest impact. No correlation was found between PANQOL score and time since treatment. Conclusion This study suggests that patients with small vestibular schwannomas experience better quality of life when managed with observation than do patients who have undergone active treatment.

  20. [Clinical characteristics of vestibular migraine: considerations in a series of 41 patients].

    PubMed

    Martinez, E; Ruiz-Pinero, M; de Lera, M; Baron, J; Pedraza, M I; Guerrero-Peral, A L

    2017-01-01

    After years of debate about its being approached from headaches and its denomination, vestibular migraine has recently been included in the research appendix of the 3rd edition of the International Headache Classification. To analyse the characteristics of a series of patients with vestibular migraine who visited because of headaches. Our sample consisted of patients who were attended in a headache unit between January 2014 and December 2015. The demographic variables and the characteristics of both migraine and vestibular symptoms were considered, and cases with other otorhinolaryngological conditions were excluded. The sample was finally made up of 41 patients (11 males, 30 females) with a mean age of 31.8 ± 13.3 years at the time they were included in the study. Sixteen patients (39%) met criteria for chronic migraine and two (4.9%) presented visual auras. The vestibular symptoms were considered severe in eight cases (19.5%) and occurred in 74.6% of the migraine attacks. Vertigo was described as internal in 18 cases (43.9%), external in 22 (53.7%) and mixed in one case (2.4%). The most frequent symptom was positional vertigo (n = 25; 61%), followed by that induced by head movements (n = 18; 43.9%) and spontaneous (n = 15; 36.6%). Accompanying symptoms included tinnitus (n = 12; 29.3%) and a feeling of fullness in the ear (n = 8; 19.5%). It is not uncommon to identify symptoms consistent with vestibular migraine in patients who visit a headache unit; they are patients whose day-to-day activities are not usually affected by their vertigo.

  1. Does Otosclerosis Affect Dark and Transitional Cells in the Human Vestibular Labyrinth?

    PubMed Central

    Kaya, Serdar; Paparella, Michael M.; Cureoglu, Sebahattin

    2016-01-01

    Hypothesis The density of vestibular dark cells (DCs) and vestibular transitional cells (TCs) can be quantitatively decreased in human temporal bones with otosclerosis. Background Previous reports have shown that otosclerosis can lead to vestibular symptoms. Methods We examined 61 human temporal bone specimens from 52 deceased donors with otosclerosis group—with and without endosteal involvement (EI), and with and without endolymphatic hydrops (EH)—vs. 25 specimens from 18 age-matched controls. Using light microscopy, we evaluated the nonsensory epithelium of the lateral semicircular canal (LSC) and posterior semicircular canal (PSC) of the human vestibular labyrinth, focusing on the density of DCs and TCs. Results In both the LSC and the PSC, as compared with the control group, the mean density of DCs significantly decreased in the EI (+) group, in the EI (+) and EH (+) subgroup, and in the EI (+) and EH (−) subgroup (P < 0.05). In addition, we found a significant difference in the mean density of DCs between the EI (+) group and the EI (−) group in the LSC and in the PSC (P < 0.05). But we found no significant difference in the mean density of TCs in any of the otosclerosis groups or subgroups as compared with the control group (P > 0.05). Conclusion We found a decrease in the density of DCs associated with EI in human temporal bone specimens with otosclerosis, regardless of the presence of EH. This decrease might cause damage in ion and water transportation, leading to vestibular symptoms. PMID:27851656

  2. 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.

  3. Anxiety and depression among patients with different types of vestibular peripheral vertigo.

    PubMed

    Yuan, Qing; Yu, Lisheng; Shi, Dongmei; Ke, Xingxing; Zhang, Hua

    2015-02-01

    Numerous studies have been published on comorbid anxiety and depression in patients with vertigo. However, very few studies have separately described and analyzed anxiety or depression in patients with different types of vestibular peripheral vertigo. The present study investigated anxiety and depression among patients with 4 different types of peripheral vertigo. A total of 129 patients with 4 types of peripheral vertigo, namely, benign paroxysmal positional vertigo (BPPV, n = 49), migrainous vertigo (MV, n = 37), Menière disease (MD, n = 28), and vestibular neuritis (VN, n = 15), were included in the present study. Otological and neurootological examinations were carefully performed, and self-rating anxiety scale and self-rating depression scale were used to evaluate anxiety and depression. Patients were divided into 2 groups, according to the vestibular function: normal and abnormal vestibular function. There was no significant difference in the risk of anxiety/depression between these 2 groups. However, for patients with the 4 different vertigo types, the prevalence of anxiety (MV = 45.9%, MD = 50%) and depression (MV = 27%, MD = 28.6%) was significantly higher in the patients with MV or MD than those with BPPV or VN (P < 0.05). Vestibular function is not significantly associated with the risk of anxiety/depression. Anxiety/depression is more common in patients with MV or MD than those with BPPV or VN. This may be due to the different mechanisms involved in these 4 types of vertigo, as well as differences in the prevention and self-control of the patients against the vertigo.

  4. Vestibular responses in the macaque pedunculopontine nucleus and central mesencephalic reticular formation.

    PubMed

    Aravamuthan, B R; Angelaki, D E

    2012-10-25

    The pedunculopontine nucleus (PPN) and central mesencephalic reticular formation (cMRF) both send projections and receive input from areas with known vestibular responses. Noting their connections with the basal ganglia, the locomotor disturbances that occur following lesions of the PPN or cMRF, and the encouraging results of PPN deep brain stimulation in Parkinson's disease patients, both the PPN and cMRF have been linked to motor control. In order to determine the existence of and characterize vestibular responses in the PPN and cMRF, we recorded single neurons from both structures during vertical and horizontal rotation, translation, and visual pursuit stimuli. The majority of PPN cells (72.5%) were vestibular-only (VO) cells that responded exclusively to rotation and translation stimuli but not visual pursuit. Visual pursuit responses were much more prevalent in the cMRF (57.1%) though close to half of cMRF cells were VO cells (41.1%). Directional preferences also differed between the PPN, which was preferentially modulated during nose-down pitch, and cMRF, which was preferentially modulated during ipsilateral yaw rotation. Finally, amplitude responses were similar between the PPN and cMRF during rotation and pursuit stimuli, but PPN responses to translation were of higher amplitude than cMRF responses. Taken together with their connections to the vestibular circuit, these results implicate the PPN and cMRF in the processing of vestibular stimuli and suggest important roles for both in responding to motion perturbations like falls and turns. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

  5. Vestibular-Somatosensory Convergence in Head Movement Control During Locomotion after Long-Duration Space Flight

    NASA Technical Reports Server (NTRS)

    Mulavara, Ajitkumar; Ruttley, Tara; Cohen, Helen; Peters, Brian; Miller, Chris; Brady, Rachel; Merkle, Lauren; Bloomberg, Jacob

    2010-01-01

    Exposure to the microgravity conditions of space flight induces adaptive modification in the control of vestibular-mediated reflexive head movement during locomotion after space flight. Space flight causes astronauts to be exposed to somatosensory adaptation in both the vestibular and body load-sensing (BLS) systems. The goal of these studies was to examine the contributions of vestibular and BLS-mediated somatosensory influences on head movement control during locomotion after long-duration space flight. Subjects were asked to walk on a treadmill driven at 1.8 m/s while performing a visual acuity task. Data were collected using the same testing protocol from three independent subject groups; 1) normal subjects before and after exposure to 30 minutes of 40% bodyweight unloaded treadmill walking, 2) bilateral labyrinthine deficient (LD) patients and 3) astronauts who performed the protocol before and after long duration space flight. Motion data from head and trunk segmental motion data were obtained to calculate the angular head pitch (HP) movements during walking trials while subjects performed the visual task, to estimate the contributions of vestibular reflexive mechanisms in HP movements. Results showed that exposure to unloaded locomotion caused a significant increase in HP movements, whereas in the LD patients the HP movements were significantly decreased. Astronaut subjects results showed a heterogeneous response of both increases and decreases in the amplitude of HP movement. We infer that BLS-mediated somatosensory input centrally modulates vestibular input and can adaptively modify head-movement control during locomotion. Thus, space flight may cause a central adaptation mediated by the converging vestibular and body load-sensing somatosensory systems.

  6. Uptake of Fluorescent Gentamicin by Peripheral Vestibular Cells after Systemic Administration

    PubMed Central

    Liu, Jianping; Kachelmeier, Allan; Dai, Chunfu; Li, Hongzhe; Steyger, Peter S.

    2015-01-01

    Objective In addition to cochleotoxicity, systemic aminoglycoside pharmacotherapy causes vestibulotoxicity resulting in imbalance and visual dysfunction. The underlying trafficking routes of systemically-administered aminoglycosides from the vasculature to the vestibular sensory hair cells are largely unknown. We investigated the trafficking of systemically-administered gentamicin into the peripheral vestibular system in C56Bl/6 mice using fluorescence-tagged gentamicin (gentamicin-Texas-Red, GTTR) imaged by scanning laser confocal microscopy to determine the cellular distribution and intensity of GTTR fluorescence in the three semicircular canal cristae, utricular, and saccular maculae at 5 time points over 4 hours. Results Low intensity GTTR fluorescence was detected at 0.5 hours as both discrete puncta and diffuse cytoplasmic fluorescence. The intensity of cytoplasmic fluorescence peaked at 3 hours, while punctate fluorescence was plateaued after 3 hours. At 0.5 and 1 hour, higher levels of diffuse GTTR fluorescence were present in transitional cells compared to hair cells and supporting cells. Sensory hair cells typically exhibited only diffuse cytoplasmic fluorescence at all time-points up to 4 hours in this study. In contrast, non-sensory cells rapidly exhibited both intense fluorescent puncta and weaker, diffuse fluorescence throughout the cytosol. The numbers and size of fluorescent puncta in dark cells and transitional cells increased over time. There is no preferential GTTR uptake by the five peripheral vestibular organs’ sensory cells. Control vestibular tissues exposed to Dulbecco’s phosphate-buffered saline or hydrolyzed Texas Red had negligible fluorescence. Conclusions All peripheral vestibular cells rapidly take up systemically-administered GTTR, reaching peak intensity 3 hours after injection. Sensory hair cells exhibited only diffuse fluorescence, while non-sensory cells displayed both diffuse and punctate fluorescence. Transitional cells may

  7. Effects of Vestibular Loss on Orthostatic Responses to Tilts in the Pitch Plane

    NASA Technical Reports Server (NTRS)

    Wood, Scott J.; Serrador, Jorge M.; Black, F. Owen; Rupert,Angus H.; Schlegel, Todd T.

    2004-01-01

    The purpose of this study was to determine the extent to which vestibular loss might impair orthostatic responses to passive tilts in the pitch plane in human subjects. Data were obtained from six subjects having chronic bilateral vestibular loss and six healthy individuals matched for age, gender, and body mass index. Vestibular loss was assessed with a comprehensive battery including dynamic posturography, vestibulo-ocular and optokinetic reflexes, vestibular evoked myogenic potentials, and ocular counterrolling. Head up tilt tests were conducted using a motorized two-axis table that allowed subjects to be tilted in the pitch plane from either a supine or prone body orientation at a slow rate (8 deg/s). The sessions consisted of three tilts, each consisting of20 min rest in a horizontal position, tilt to 80 deg upright for 10 min, and then return to the horizontal position for 5 min. The tilts were performed in darkness (supine and prone) or in light (supine only). Background music was used to mask auditory orientation cues. Autonomic measurements included beat-to-beat recordings of blood pressure (Finapres), heart rate (ECG), cerebral blood flow velocity in the middle cerebral artery (transcranial Doppler), end tidal CO2, respiratory rate and volume (Respritrace), and stroke volume (impedance cardiography). For both patients and control subjects, cerebral blood flow appeared to exhibit the most rapid adjustment following transient changes in posture. Outside of a greater cerebral hypoperfusion in patients during the later stages of tilt, responses did not differ dramatically between the vestibular loss and control subjects, or between tilts performed in light and dark room conditions. Thus, with the 'exception of cerebrovascular regulation, we conclude that orthostatic responses during slow postural tilts are not substantially impaired in humans following chronic loss of vestibular function, a result that might reflect compensation by nonvisual graviceptor

  8. 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

  9. Altered resting-state functional connectivity in patients with chronic bilateral vestibular failure.

    PubMed

    Göttlich, Martin; Jandl, Nico M; Wojak, Jann F; Sprenger, Andreas; von der Gablentz, Janina; Münte, Thomas F; Krämer, Ulrike M; Helmchen, Christoph

    2014-01-01

    Patients with bilateral vestibular failure (BVF) suffer from gait unsteadiness, oscillopsia and impaired spatial orientation. Brain imaging studies applying caloric irrigation to patients with BVF have shown altered neural activity of cortical visual-vestibular interaction: decreased bilateral neural activity in the posterior insula and parietal operculum and decreased deactivations in the visual cortex. It is unknown how this affects functional connectivity in the resting brain and how changes in connectivity are related to vestibular impairment. We applied a novel data driven approach based on graph theory to investigate altered whole-brain resting-state functional connectivity in BVF patients (n= 22) compared to age- and gender-matched healthy controls (n= 25) using resting-state fMRI. Changes in functional connectivity were related to subjective (vestibular scores) and objective functional parameters of vestibular impairment, specifically, the adaptive changes during active (self-guided) and passive (investigator driven) head impulse test (HIT) which reflects the integrity of the vestibulo-ocular reflex (VOR). BVF patients showed lower bilateral connectivity in the posterior insula and parietal operculum but higher connectivity in the posterior cerebellum compared to controls. Seed-based analysis revealed stronger connectivity from the right posterior insula to the precuneus, anterior insula, anterior cingulate cortex and the middle frontal gyrus. Excitingly, functional connectivity in the supramarginal gyrus (SMG) of the inferior parietal lobe and posterior cerebellum correlated with the increase of VOR gain during active as compared to passive HIT, i.e., the larger the adaptive VOR changes the larger was the increase in regional functional connectivity. Using whole brain resting-state connectivity analysis in BVF patients we show that enduring bilateral deficient or missing vestibular input leads to changes in resting-state connectivity of the brain. These

  10. Investigations of the Effects of Altered Vestibular System Function on Hindlimb Anti-Gravity Muscles

    NASA Technical Reports Server (NTRS)

    Lowery, Mary Sue

    1998-01-01

    Exposure to different gravitational environments, both the microgravity of spaceflight and the hypergravity of centrifugation, result in altered vestibulo-spinal function which can be reversed by reacclimation to earth gravity (2). Control of orientation, posture, and locomotion are functions of the vestibular system which are altered by changes in gravitational environment. Not only is the vestibular system involved with coordination and proprioception, but the gravity sensing portion of the vestibular system also plays a major role in maintaining muscle tone through projections to spinal cord motoneurons that control anti-gravity muscles. I have been involved with investigations of several aspects of the link between vestibular inputs and muscle morphology and function during my work with Dr. Nancy Daunton this summer and the previous summer. We have prepared a manuscript for submission (4) to Aviation, Space, and Environmental Medicine based on work that I performed last summer in Dr. Daunton's lab. Techniques developed for that project will be utilized in subsequent experiments begun in the summer of 1998. I have been involved with the development of a pilot project to test the effects of vestibular galvanic stimulation (VGS) on anti-gravity muscles and in another project testing the effects of the ototoxic drug streptomycin on the otolith-spinal reflex and anti-gravity muscle morphology.

  11. 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

  12. 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.

  13. Vestibular signals in macaque extrastriate visual cortex are functionally appropriate for heading perception

    PubMed Central

    Liu, Sheng; Angelaki, Dora E.

    2009-01-01

    Visual and vestibular signals converge onto the dorsal medial superior temporal area (MSTd) of the macaque extrastriate visual cortex, which is thought to be involved in multisensory heading perception for spatial navigation. Peripheral otolith information, however, is ambiguous and cannot distinguish linear accelerations experienced during self-motion from those due to changes in spatial orientation relative to gravity. Here we show that, unlike peripheral vestibular sensors but similar to lobules 9 and 10 of the cerebellar vermis (nodulus and uvula), MSTd neurons respond selectively to heading and not to changes in orientation relative to gravity. In support of a role in heading perception, MSTd vestibular responses are also dominated by velocity-like temporal dynamics, which might optimize sensory integration with visual motion information. Unlike the cerebellar vermis, however, MSTd neurons also carry a spatial orientation-independent rotation signal from the semicircular canals, which could be useful in compensating for the effects of head rotation on the processing of optic flow. These findings show that vestibular signals in MSTd are appropriately processed to support a functional role in multisensory heading perception. PMID:19605631

  14. 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.

  15. 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

  16. 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.

  17. Regional differences in lectin binding patterns of vestibular hair cells

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

    Surface glycoconjugates of hair cells and supporting cells in the vestibular endorgans of the bullfrog were identified using biotinylated lectins with different carbohydrate specificities. Lectin binding in hair cells was consistent with the presence of glucose and mannose (CON A), galactose (RCA-I), N-acetylgalactosamine (VVA), but not fucose (UEA-I) residues. Hair cells in the bullfrog sacculus, unlike those in the utriculus and semicircular canals, did not stain for N-acetylglucosamine (WGA) or N-acetylgalactosamine (VVA). By contrast, WGA and, to a lesser extent, VVA, differentially stained utricular and semicircular canal hair cells, labeling hair cells located in peripheral, but not central, regions. In mammals, WGA uniformly labeled Type 1 hair cells while labeling, as in the bullfrog, Type 2 hair cells only in peripheral regions. These regional variations were retained after enzymatic digestion. We conclude that vestibular hair cells differ in their surface glycoconjugates and that differences in lectin binding patterns can be used to identify hair cell types and to infer the epithelial origin of isolated vestibular hair cells.

  18. Regional differences in lectin binding patterns of vestibular hair cells

    NASA Technical Reports Server (NTRS)

    Baird, R. A.; Schuff, N. R.; Bancroft, J.

    1993-01-01

    Surface glycoconjugates of hair cells and supporting cells in the vestibular endorgans of the bullfrog were identified using biotinylated lectins with different carbohydrate specificities. Lectin binding in hair cells was consistent with the presence of glucose and mannose (CON A), galactose (RCA-I), N-acetylglucosamine (WGA), N-acetylgalactosamine (VVA), but not fucose (UEA-I) residues. Hair cells in the bullfrog sacculus, unlike those in the utriculus and semicircular canals, did not strain for N-acetylglucosamine (WGA) or N-acetylgalactosamine (VVA). By contrast, WGA and, to a lesser extent, VVA, differentially stained utricular and semicircular canal hair cells, labeling hair cells located in peripheral, but not central, regions. In mammals, WGA uniformly labeled Type I hair cells while labeling, as in the bullfrog, Type II hair cells only in peripheral regions. These regional variations were retained after enzymatic digestion. We conclude that vestibular hair cells differ in their surface glycoconjugates and that differences in lectin binding patterns can be used to identify hair cell types and to infer the epithelial origin of isolated vestibular hair cells.

  19. Counteracting Muscle Atrophy using Galvanic Stimulation of the Vestibular System

    NASA Technical Reports Server (NTRS)

    Fox, Robert A.; Polyakov, Igor

    1999-01-01

    The unloading of weight bearing from antigravity muscles during space flight produces significant muscle atrophy and is one of the most serious health problems facing the space program. Various exercise regimens have been developed and used either alone or in combination with pharmacological techniques to ameliorate this atrophy, but no effective countermeasure exists for this problem. The research in this project was conducted to evaluate the potential use of vestibular galvanic stimulation (VGS) to prevent muscle atrophy resulting from unloading of weight bearing from antigravity muscles. This approach was developed based on two concepts related to the process of maintaining the status of the anti-gravity neuromuscular system. These two premises are: (1) The "tone," or bias on spinal motorneurons is affected by vestibular projections that contribute importantly to maintaining muscle health and status. (2) VGS can be used to modify the excitability, or 'tone' of motorneuron of antigravity muscles. Thus, the strategy is to use VGS to modify the gain of vestibular projections to antigravity muscles and thereby change the general status of these muscles.

  20. Interaction of visual and vestibular stimulation on spatial coordinates for eye movements in rabbits.

    PubMed

    Pettorossi, V E; Errico, P; Ferraresi, A; Minciotti, M; Barmack, N H

    1998-07-01

    Researchers investigated how vestibular and optokinetic signals alter the spatial transformation of the coordinate system that governs the spatial orientation of reflexive eye movements. Also examined were the effects of sensory stimulation when vestibular and optokinetic signals act synergistically and when the two signals are in conflict.

  1. 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

  2. Differential effects of galvanic vestibular stimulation on arm position sense in right- vs. left-handers.

    PubMed

    Schmidt, Lena; Artinger, Frank; Stumpf, Oliver; Kerkhoff, Georg

    2013-04-01

    The human brain is organized asymmetrically in two hemispheres with different functional specializations. Left- and right-handers differ in many functional capacities and their anatomical representations. Right-handers often show a stronger functional lateralization than left-handers, the latter showing a more bilateral, symmetrical brain organization. Recent functional imaging evidence shows a different lateralization of the cortical vestibular system towards the side of the preferred hand in left- vs. right-handers as well. Since the vestibular system is involved in somatosensory processing and the coding of body position, vestibular stimulation should affect such capacities differentially in left- vs. right-handers. In the present, sham-stimulation-controlled study we explored this hypothesis by studying the effects of galvanic vestibular stimulation (GVS) on proprioception in both forearms in left- and right-handers. Horizontal arm position sense (APS) was measured with an opto-electronic device. Second, the polarity-specific online- and after-effects of subsensory, bipolar GVS on APS were investigated in different sessions separately for both forearms. At baseline, both groups did not differ in their unsigned errors for both arms. However, right-handers showed significant directional errors in APS of both arms towards their own body. Right-cathodal/left-anodal GVS, resulting in right vestibular cortex activation, significantly deteriorated left APS in right-handers, but had no detectable effect on APS in left-handers in either arm. These findings are compatible with a right-hemisphere dominance for vestibular functions in right-handers and a differential vestibular organization in left-handers that compensates for the disturbing effects of GVS on APS. Moreover, our results show superior arm proprioception in left-handers in both forearms. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Symptoms elicited in persons with vestibular dysfunction while performing gaze movements in optic flow environments

    PubMed Central

    Whitney, Susan L.; Sparto, Patrick J.; Cook, James R.; Redfern, Mark S.; Furman, Joseph M.

    2016-01-01

    Introduction People with vestibular disorders often experience space and motion discomfort when exposed to moving or highly textured visual scenes. The purpose of this study was to measure the type and severity of symptoms in people with vestibular dysfunction during coordinated head and eye movements in optic flow environments. Methods Seven subjects with vestibular disorders and 25 controls viewed four different full-field optic flow environments on six different visits. The optic flow environments consisted of textures with various contrasts and spatial frequencies. Subjects performed 8 gaze movement tasks, including eye saccades, gaze saccades, and gaze stabilization tasks. Subjects reported symptoms using Subjective Units of Discomfort (SUD) and the Simulator Sickness Questionnaire (SSQ). Self-reported dizziness handicap and space and motion discomfort were also measured. Results/ Conclusion Subjects with vestibular disorders had greater discomfort and experienced greater oculomotor and disorientation symptoms. The magnitude of the symptoms increased during each visit, but did not depend on the optic flow condition. Subjects who reported greater dizziness handicap and space motion discomfort had greater severity of symptoms during the experiment. Symptoms of fatigue, difficulty focusing, and dizziness during the experiment were evident. Compared with controls, subjects with vestibular disorders had less head movement during the gaze saccade tasks. Overall, performance of gaze pursuit and gaze stabilization tasks in moving visual environments elicited greater symptoms in subjects with vestibular disorders compared with healthy subjects. PMID:23549055

  4. Role of the vestibular nuclei in endothelin-1-induced barrel rotation in rats.

    PubMed

    Kozako, Tomohiro; Kawachi, Akio; Cheng, Shi-Bin; Kuchiiwa, Satoshi; Motoya, Toshiro; Nakagawa, Shiro; Yamada, Katsushi

    2002-11-15

    The fourth or lateral ventricular injection of endothelin-1 resulted in a dose-dependent increase in the barrel rotation and produced marked induction of c-Fos-positive cells in the vestibular nuclei. The doses of the former injection were lower and had shorter mean latent periods compared with the later injection. c-Fos expression after endothelin-1 injection was prevented by the pretreatment with the endothelin ET(A) receptor antagonist, cyclo(D-alpha-aspartyl-L-propyl-D-valyl-L-leucyl-D-tryptophyl) (BQ-123), the glutamate NMDA receptor antagonist, dizocilpine maleate (MK-801), or the L-type Ca(2+) channel antagonist, verapamil, in addition to the incidence of the rotational behavior. There was a significant difference in c-Fos expression between the right and left medial vestibular nuclei, and the number of c-Fos-labeled neurons in the medial vestibular nucleus was markedly increased on the opposite side of the rotational direction. These results suggest that the elicitation of the barrel rotation may be mediated by endothelin ET(A) receptors, glutamate NMDA receptors, and L-type Ca(2+) channels. The changes in the receptor and channel systems induced by endothelin-1 injections appeared to exert crucial influences on the vestibular nuclei and then on the maintenance of equilibrium. The direction of the barrel rotation has a deep connection with the imbalance of neuronal activity in the left and right medial vestibular nuclei.

  5. Can the Risks of Cerebrospinal Fluid Leak After Vestibular Schwannoma Surgery Be Predicted?

    PubMed

    Russel, Adrien; Hoffmann, Charles P; Nguyen, Duc T; Beurton, Renaud; Parietti-Winkler, Cécile

    2017-02-01

    Identifying predictive factors of cerebrospinal fluid (CSF) leak after translabyrinthine approach (TLA) for vestibular schwannoma. Retrospective study. Tertiary care center. All patients (n = 275) operated for a vestibular schwannoma by TLA between 2004 and 2013 were included. Vestibular schwannoma surgery by TLA. The rate of postoperative CSF leak considering the age, sex, body mass index (BMI), tumor staging, and duration of surgical procedure. A logistic regression model was used to identify the predictors and compute a biometric predictive model of CSF leak. Thirty-three patients (12.0%) developed a CSF leak after surgery. In a multivariable model, an increased risk of CSF leak was found for younger patients (OR 0.95, 95% CI 0.92-0.98), longer duration of surgery (OR 1.85, 95% CI 1.12-3.05), and the male sex (0 = male; 1 = female; OR 0.22, 95% CI 0.09-0.54), while also adjusting for BMI. The probability of developing a CSF leak after vestibular schwannoma surgery was calculated using a statistical prediction model, with a percentage of false negative of 7.0% and an overall correct prediction of 88.4%. The predictors of CSF leak after TLA for vestibular schwannoma are young age, male sex, longer duration of surgery, which adjusting for BMI. In this regard, the surgical team should adapt its management during pre- and postoperative period to decrease the likelihood of a leak.

  6. 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.

  7. Comparative Transduction Mechanisms of Vestibular Otolith Hair Cells

    NASA Technical Reports Server (NTRS)

    Baird, Richard A.

    1994-01-01

    Hair cells in the bullfrog vestibular otolith organs regenerate following aminoglycoside ototoxicity. Hair cells in these organs are differentially sensitive to gentamicin, with saccular hair cells and hair cells in the utricular striola being damaged at lower gentamicin concentrations than hair cells in the utricular extrastriola. Regenerating hair cells in these organs have short hair bundles and can be classified into a number of phenotypes using the same morphological criteria used to identify their mature counterparts. Our studies suggest that some supporting cells can convert, or transdifferentiate,into hair cells without an intervening cell division. By stimulating these processes in humans, clinicians may be able to alleviate human deafness and peripheral vestibular disorders by regenerating and replacing lost hair cells. In vivo and in vitro studies were done on cell proliferation and hair cell regeneration.

  8. Determine Optimal Stimulus Amplitude for Using Vestibular Stochastic Stimulation to Improve Balance Function

    NASA Technical Reports Server (NTRS)

    Goel, R.; Kofman, I.; DeDios, Y. E.; Jeevarajan, J.; Stepanyan, V.; Nair, M.; Congdon, S.; Fregia, M.; Cohen, H.; Bloomberg, J.J.; hide

    2015-01-01

    Sensorimotor changes such as postural and gait instabilities can affect the functional performance of astronauts when they transition across different gravity environments. We are developing a method, based on stochastic resonance (SR), to enhance information transfer by applying non-zero levels of external noise on the vestibular system (vestibular stochastic resonance, VSR). Our previous work has shown the advantageous effects of VSR in a balance task of standing on an unstable surface [1]. This technique to improve detection of vestibular signals uses a stimulus delivery system that provides imperceptibly low levels of white noise-based binaural bipolar electrical stimulation of the vestibular system. The goal of this project is to determine optimal levels of stimulation for SR applications by using a defined vestibular threshold of motion detection. A series of experiments were carried out to determine a robust paradigm to identify a vestibular threshold that can then be used to recommend optimal stimulation levels for sensorimotor adaptability (SA) training applications customized to each crewmember. The amplitude of stimulation to be used in the VSR application has varied across studies in the literature such as 60% of nociceptive stimulus thresholds [2]. We compared subjects' perceptual threshold with that obtained from two measures of body sway. Each test session was 463s long and consisted of several 15s long sinusoidal stimuli, at different current amplitudes (0-2 mA), interspersed with 20-20.5s periods of no stimulation. Subjects sat on a chair with their eyes closed and had to report their perception of motion through a joystick. A force plate underneath the chair recorded medio-lateral shear forces and roll moments. Comparison of threshold of motion detection obtained from joystick data versus body sway suggests that perceptual thresholds were significantly lower. In the balance task, subjects stood on an unstable surface and had to maintain balance

  9. Bioinformatic Integration of Molecular Networks and Major Pathways Involved in Mice Cochlear and Vestibular Supporting Cells.

    PubMed

    Requena, Teresa; Gallego-Martinez, Alvaro; Lopez-Escamez, Jose A

    2018-01-01

    Background : Cochlear and vestibular epithelial non-hair cells (ENHCs) are the supporting elements of the cellular architecture in the organ of Corti and the vestibular neuroepithelium in the inner ear. Intercellular and cell-extracellular matrix interactions are essential to prevent an abnormal ion redistribution leading to hearing and vestibular loss. The aim of this study is to define the main pathways and molecular networks in the mouse ENHCs. Methods : We retrieved microarray and RNA-seq datasets from mouse epithelial sensory and non-sensory cells from gEAR portal (http://umgear.org/index.html) and obtained gene expression fold-change between ENHCs and non-epithelial cells (NECs) against HCs for each gene. Differentially expressed genes (DEG) with a log2 fold change between 1 and -1 were discarded. The remaining genes were selected to search for interactions using Ingenuity Pathway Analysis and STRING platform. Specific molecular networks for ENHCs in the cochlea and the vestibular organs were generated and significant pathways were identified. Results : Between 1723 and 1559 DEG were found in the mouse cochlear and vestibular tissues, respectively. Six main pathways showed enrichment in the supporting cells in both tissues: (1) "Inhibition of Matrix Metalloproteases"; (2) "Calcium Transport I"; (3) "Calcium Signaling"; (4) "Leukocyte Extravasation Signaling"; (5) "Signaling by Rho Family GTPases"; and (6) "Axonal Guidance Si". In the mouse cochlea, ENHCs showed a significant enrichment in 18 pathways highlighting "axonal guidance signaling (AGS)" ( p = 4.37 × 10 -8 ) and "RhoGDI Signaling" ( p = 3.31 × 10 -8 ). In the vestibular dataset, there were 20 enriched pathways in ENHCs, the most significant being "Leukocyte Extravasation Signaling" ( p = 8.71 × 10 -6 ), "Signaling by Rho Family GTPases" ( p = 1.20 × 10 -5 ) and "Calcium Signaling" ( p = 1.20 × 10 -5 ). Among the top ranked networks, the most biologically significant network contained the

  10. Technique of electrical stimulation of the vestibular analyzer under clinical conditions

    NASA Technical Reports Server (NTRS)

    Khechinashvili, S. N.; Zargaryan, B. M.; Karakozov, K. G.

    1980-01-01

    Vestibular reactions appear under the action of direct current (dc) on the labyrinth of man and animals. A decrease of the stimulation effect of dc on the extralabyrinthine nervous formations in the suggested method is achieved by the use of electric pulses with steep front and back parts, as well as by previous anesthetization of the skin in the electrode application area by means of novocain solution electrophoresis. For this purpose a pulse producer giving trapezoid pulses with smoothly changing fronts and duration was constructed. With the help of an interrupter it is possible to stop the current increase instantly, and stimulation is performed at the level of the pulse 'plateau'. To induce vestibular reactions under monopolar stimulation, it is necessary to apply the current twice as high as that with bipolar electrode position. The use of short pulses with steep front and back parts for electrode stimulation of the vestibular analyzer is considered to be inexpedient.

  11. Vestibular Assessments in Children With Global Developmental Delay: An Exploratory Study.

    PubMed

    Dannenbaum, Elizabeth; Horne, Victoria; Malik, Farwa; Villeneuve, Myriam; Salvo, Lora; Chilingaryan, Gevorg; Lamontagne, Anouk

    2016-01-01

    To compare results of 3 clinical vestibular tests between children with global developmental delay (GDD) and children with typical development (TD) and investigate the test-retest reliability. Twenty children with GDD (aged 4.1-12.1 years) and 11 age-matched controls with TD participated. Participants with GDD underwent 2 sessions of testing. Each session consisted of the Clinical Test of Sensory Interaction and Balance (CTSIB), Dynamic Visual Acuity (DVA) test, and the modified Emory Clinical Vestibular Chair Test (m-ECVCT). Up to 33% of the children with GDD had abnormal DVA scores. m-ECVCT results of children with GDD demonstrated larger variance than children with TD. The CTSIB score was significantly reduced in the group with GDD. The test-retest reliability varied, with good reliability for the m-ECVCT and CTSIB, and fair reliability for the DVA. Findings suggest vestibular involvement in children in GDD. The clinical tests demonstrated moderate test-retest reliability.

  12. 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.

  13. [Static posturography versus clinical tests in elderly people with vestibular pathology].

    PubMed

    Ortuño-Cortés, Miguel A; Martín-Sanz, Eduardo; Barona-de Guzmán, Rafael

    2008-01-01

    Balance can be quantified by clinical tests and through instrumental studies. The objective of this paper is to determine the correlation between static posturography and 4 clinical tests of balance in elderly people with vestibular disorders and to identify its capability to discriminate the groups studied. 60 patients with vestibular disorders and 60 healthy subjects performed 4 clinical tests (one leg standing with opened eyes, Timed Up and Go, Tinetti and Berg tests) and a static posturography analysis (NedSVE/IBV system) under 4 conditions: Romberg Test, Eyes Open (REO), Romberg Test, Eyes Closed (REC), Romberg Test on Foam with Eyes Open (RFEO), and Romberg Test on Foam with Eyes Closed (RFEC). RFEO correlated best with the clinical tests and RFEC was the worst. RFEO distinguished between healthy individuals and decompensated patients. RFEO gave the best information about postural balance in the elderly. RFEC was not useful. Static posturography can be useful to distinguish vestibular compensation status.

  14. A short latency vestibular evoked potential (VsEP) produced by bone-conducted acoustic stimulation

    NASA Astrophysics Data System (ADS)

    McAngus Todd, Neil P.; Rosengren, Sally M.; Colebatch, James G.

    2003-12-01

    In this paper data are presented from an experiment which provides evidence for the existence of a short latency, acoustically evoked potential of probable vestibular origin. The experiment was conducted in two phases using bone-conducted acoustic stimulation. In the first phase subjects were stimulated with 6-ms, 500-Hz tone bursts in order to obtain the threshold VT for vestibular evoked myogenic potentials (VEMP). It was confirmed that the difference between bone-conducted auditory and acoustic vestibular thresholds was slightly over 30 dB. The estimated threshold was then used as a reference value in the second part of the experiment to stimulate subjects over a range of intensities from -6 to +18 dB (re:VT). Averaged EEG recordings were made with eight Ag/AgCl electrodes placed on the scalp at Fpz, F3, F4, F7, F8, Cz, T3, and T4 according to the 10-20 system. Below VT auditory midlatency responses (MLRs) were observed. Above VT two additional potentials appeared: a positivity at about 10 ms (P10) which was maximal at Cz, and a negativity at about 15 ms (N15) which was maximal at Fpz. Extrapolation of the growth functions for the P10 and N15 indicated a threshold close to VT, consistent with a vestibular origin of these potentials. Given the low threshold of vestibular acoustic sensitivity it is possible that this mode may make a contribution to the detection of and affective responses to loud low frequency sounds. The evoked potentials may also have application as a noninvasive and nontraumatic test of vestibular projections to the cortex.

  15. Information transmission and detection thresholds in the vestibular nuclei: single neurons vs. population encoding

    PubMed Central

    Massot, Corentin; Chacron, Maurice J.

    2011-01-01

    Understanding how sensory neurons transmit information about relevant stimuli remains a major goal in neuroscience. Of particular relevance are the roles of neural variability and spike timing in neural coding. Peripheral vestibular afferents display differential variability that is correlated with the importance of spike timing; regular afferents display little variability and use a timing code to transmit information about sensory input. Irregular afferents, conversely, display greater variability and instead use a rate code. We studied how central neurons within the vestibular nuclei integrate information from both afferent classes by recording from a group of neurons termed vestibular only (VO) that are known to make contributions to vestibulospinal reflexes and project to higher-order centers. We found that, although individual central neurons had sensitivities that were greater than or equal to those of individual afferents, they transmitted less information. In addition, their velocity detection thresholds were significantly greater than those of individual afferents. This is because VO neurons display greater variability, which is detrimental to information transmission and signal detection. Combining activities from multiple VO neurons increased information transmission. However, the information rates were still much lower than those of equivalent afferent populations. Furthermore, combining responses from multiple VO neurons led to lower velocity detection threshold values approaching those measured from behavior (∼2.5 vs. 0.5–1°/s). Our results suggest that the detailed time course of vestibular stimuli encoded by afferents is not transmitted by VO neurons. Instead, they suggest that higher vestibular pathways must integrate information from central vestibular neuron populations to give rise to behaviorally observed detection thresholds. PMID:21307329

  16. 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

  17. 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.

  18. Anxiety and Depression Among Patients With Different Types of Vestibular Peripheral Vertigo

    PubMed Central

    Yuan, Qing; Yu, Lisheng; Shi, Dongmei; Ke, Xingxing; Zhang, Hua

    2015-01-01

    Abstract Numerous studies have been published on comorbid anxiety and depression in patients with vertigo. However, very few studies have separately described and analyzed anxiety or depression in patients with different types of vestibular peripheral vertigo. The present study investigated anxiety and depression among patients with 4 different types of peripheral vertigo. A total of 129 patients with 4 types of peripheral vertigo, namely, benign paroxysmal positional vertigo (BPPV, n = 49), migrainous vertigo (MV, n = 37), Menière disease (MD, n = 28), and vestibular neuritis (VN, n = 15), were included in the present study. Otological and neurootological examinations were carefully performed, and self-rating anxiety scale and self-rating depression scale were used to evaluate anxiety and depression. Patients were divided into 2 groups, according to the vestibular function: normal and abnormal vestibular function. There was no significant difference in the risk of anxiety/depression between these 2 groups. However, for patients with the 4 different vertigo types, the prevalence of anxiety (MV = 45.9%, MD = 50%) and depression (MV = 27%, MD = 28.6%) was significantly higher in the patients with MV or MD than those with BPPV or VN (P < 0.05). Vestibular function is not significantly associated with the risk of anxiety/depression. Anxiety/depression is more common in patients with MV or MD than those with BPPV or VN. This may be due to the different mechanisms involved in these 4 types of vertigo, as well as differences in the prevention and self-control of the patients against the vertigo. PMID:25654382

  19. The effects of vestibular stimulation on a child with hypotonic cerebral palsy

    PubMed Central

    An, Sun-Joung Leigh

    2015-01-01

    [Purpose] The purpose of this case report is to present the effects of vestibular stimulation on a child with hypotonic cerebral palsy through the use of swings. [Case Description] The subject was a 19-month-old boy with a diagnosis of hypotonic cerebral palsy (CP) and oscillating nystagmus. The subject had received both physical therapy and occupational therapy two times per week since he was 5 months old but showed little to no improvement. [Methods] Pre and post-intervention tests were completed by the researcher using the Bayley Scales of Infant and Toddler Development II. The subject was provided with vestibular stimulation 3 times per week for 10 weeks in 1 hour sessions conducted by his mother as instructed by the researcher. During this research all other therapies were stopped to determine the effects of the vestibular stimulation and to exclude the effects of other therapies. [Results] The subject demonstrated improvement of 4 months in motor skills and of 3 months in mental skills as shown by the Bayley Scales of Infant and Toddler Development II. [Conclusion] Vestibular stimulation was effective in improving postural control, movement, emotional well-being, and social participation of a child with hypotonic cerebral palsy. PMID:25995606

  20. Postural Instability Induced by Visual Motion Stimuli in Patients With Vestibular Migraine

    PubMed Central

    Lim, Yong-Hyun; Kim, Ji-Soo; Lee, Ho-Won; Kim, Sung-Hee

    2018-01-01

    Patients with vestibular migraine are susceptible to motion sickness. This study aimed to determine whether the severity of posture instability is related to the susceptibility to motion sickness. We used a visual motion paradigm with two conditions of the stimulated retinal field and the head posture to quantify postural stability while maintaining a static stance in 18 patients with vestibular migraine and in 13 age-matched healthy subjects. Three parameters of postural stability showed differences between VM patients and controls: RMS velocity (0.34 ± 0.02 cm/s vs. 0.28 ± 0.02 cm/s), RMS acceleration (8.94 ± 0.74 cm/s2 vs. 6.69 ± 0.87 cm/s2), and sway area (1.77 ± 0.22 cm2 vs. 1.04 ± 0.25 cm2). Patients with vestibular migraine showed marked postural instability of the head and neck when visual stimuli were presented in the retinal periphery. The pseudo-Coriolis effect induced by head roll tilt was not responsible for the main differences in postural instability between patients and controls. Patients with vestibular migraine showed a higher visual dependency and low stability of the postural control system when maintaining quiet standing, which may be related to susceptibility to motion sickness. PMID:29930534

  1. Postural Instability Induced by Visual Motion Stimuli in Patients With Vestibular Migraine.

    PubMed

    Lim, Yong-Hyun; Kim, Ji-Soo; Lee, Ho-Won; Kim, Sung-Hee

    2018-01-01

    Patients with vestibular migraine are susceptible to motion sickness. This study aimed to determine whether the severity of posture instability is related to the susceptibility to motion sickness. We used a visual motion paradigm with two conditions of the stimulated retinal field and the head posture to quantify postural stability while maintaining a static stance in 18 patients with vestibular migraine and in 13 age-matched healthy subjects. Three parameters of postural stability showed differences between VM patients and controls: RMS velocity (0.34 ± 0.02 cm/s vs. 0.28 ± 0.02 cm/s), RMS acceleration (8.94 ± 0.74 cm/s 2 vs. 6.69 ± 0.87 cm/s 2 ), and sway area (1.77 ± 0.22 cm 2 vs. 1.04 ± 0.25 cm 2 ). Patients with vestibular migraine showed marked postural instability of the head and neck when visual stimuli were presented in the retinal periphery. The pseudo-Coriolis effect induced by head roll tilt was not responsible for the main differences in postural instability between patients and controls. Patients with vestibular migraine showed a higher visual dependency and low stability of the postural control system when maintaining quiet standing, which may be related to susceptibility to motion sickness.

  2. 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.

  3. MICROLESIONS OF THE INFERIOR OLIVE REDUCE VESTIBULAR MODULATION OF PURKINJE CELL COMPLEX AND SIMPLE SPIKES IN MOUSE CEREBELLUM

    PubMed Central

    Barmack, N.H.; Yakhnitsa, V.

    2011-01-01

    Cerebellar Purkinje cells have two distinct action potentials: Complex spikes (CSs) are evoked by single climbing fibers that originate from the contralateral inferior olive. Simple spikes (SSs) are often ascribed to mossy fiber---granule cell---parallel fiber inputs to Purkinje cells. Although generally accepted, this view lacks experimental support. Vestibular stimulation independently activates primary afferent mossy fibers and tertiary afferent climbing fibers that project to theuvula-nodulus (folia 8-10). CSs and SSs normally discharge antiphasically during sinusoidal roll-tilt. When CSs increase, SSs decrease. We tested the relative independence of these pathways in mice by making electrolytic microlesions of the two inferior olivary nuclei from which vestibular climbing fibers originate; the β-nucleus and dorsomedial cell column (DMCC). This reduced vestibular climbing fiber signaling to the contralateral folia 8-10, while leaving intact vestibular primary and secondary afferent mossy fibers. We recorded from Purkinje cells and interneurons in folia 8-10, identified by juxtacellular labeling with neurobiotin. Microlesions of the inferior olive increased the spontaneous discharge of SSs in contralateral folia 8-10, but blocked their modulation during vestibular stimulation. The vestibularly-evoked discharge of excitatory cerebellar interneurons (granule cells and unipolar brush cells) was not modified by olivary microlesions. The modulated discharge of stellate cells, but not Golgi cells was reduced by olivary microlesions. We conclude that vestibular modulation of CSs and SSs depends on intact climbing fibers. The absence of vestibularly-modulated SSs following olivary microlesions reflects the loss of climbing fiber-evoked stellate cell discharge. PMID:21734274

  4. Sleep and vestibular adaptation: implications for function in microgravity

    NASA Technical Reports Server (NTRS)

    Hobson, J. A.; Stickgold, R.; Pace-Schott, E. F.; Leslie, K. R.

    1998-01-01

    Optimal human performance depends upon integrated sensorimotor and cognitive functions, both of which are known to be exquisitely sensitive to loss of sleep. Under the microgravity conditions of space flight, adaptation of both sensorimotor (especially vestibular) and cognitive functions (especially orientation) must occur quickly--and be maintained--despite any concurrent disruptions of sleep that may be caused by microgravity itself, or by the uncomfortable sleeping conditions of the spacecraft. It is the three-way interaction between sleep quality, general work efficiency, and sensorimotor integration that is the subject of this paper and the focus of new work in our laboratory. To record sleep under field conditions including microgravity, we utilize a novel system called the Nightcap that we have developed and extensively tested on normal and sleep-disordered subjects. To perturb the vestibular system in ground-based studies, we utilize a variety of experimental conditions including optokinetic stimulation and both minifying and reversing goggle paradigms that have been extensively studied in relation to plasticity of the vestibulo-ocular reflex. Using these techniques we will test the hypothesis that vestibular adaptation both provokes and is enhanced by REM sleep under both ground-based and space conditions. In this paper we describe preliminary results of some of our studies.

  5. Effects of vestibular rehabilitation combined with transcranial cerebellar direct current stimulation in patients with chronic dizziness: An exploratory study.

    PubMed

    Koganemaru, Satoko; Goto, Fumiyuki; Arai, Miki; Toshikuni, Keitaro; Hosoya, Makoto; Wakabayashi, Takeshi; Yamamoto, Nobuko; Minami, Shujiro; Ikeda, Satoshi; Ikoma, Katsunori; Mima, Tatsuya

    Vestibular rehabilitation is useful to alleviate chronic dizziness in patients with vestibular dysfunction. It aims to induce neuronal plasticity in the central nervous system (especially in the cerebellum) to promote vestibular compensation. Transcranial cerebellar direct current stimulation (tcDCS) reportedly enhances cerebellar function. We investigated whether vestibular rehabilitation partially combined with tcDCS is superior to the use of rehabilitation alone for the alleviation of dizziness. Patients with chronic dizziness due to vestibular dysfunction received rehabilitation concurrently with either 20-min tcDCS or sham stimulation for 5 days. Pre- and post-intervention (at 1 month) dizziness handicap inventory (DHI) scores and psychometric and motor parameters were compared. Sixteen patients completed the study. DHI scores in the tcDCS group showed significant improvement over those in the sham group (Mann-Whitney U test, p = 0.033). Vestibular rehabilitation partially combined with tcDCS appears to be a promising approach. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. 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.

  7. 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

  8. Effect of low level laser (LLL) on cochlear and vestibular inner ear including tinnitus

    NASA Astrophysics Data System (ADS)

    Rhee, Chung-Ku; Lim, Eun-Seok; Kim, Young-Saeng; Chung, Yong-Won; Jung, Jae-Yun; Chung, Phil-Sang

    2006-02-01

    Objectives: 1. To investigate preventive effect of LLL on gentamicin-induced vestibular ototoxicity. 2. To evaluate the effectiveness of lower level laser (LLL) in the treatment of tinnitus. Methods: 1. Twenty guinea pigs were divided into control and laser groups. Vestibular ototoxicity was induced by intratympanic injection of gentamicin into left ear. LLL was irradiated into left ear canal of animals in laser group. Vestibular function of the animals was evaluated with vertical and off-vertical axis rotation testing. 2. Forty patients with tinnitus were treated with ginkgo biloba orally and randomly divided into control and laser groups. The 20 patients of laser group received 80.4 J/cm2 of 830 nm laser, 3 times per week for 4 weeks, via transmeatal irradiation. Tinnitus was evaluated by visual analogue scale (VAS) and tinnitus handicap inventory (THI). Results: 1. Preventive effect of LLL to gentamicin induced vestibular ototoxicity was demonstrated by preventing reduction of gain in slow harmonic acceleration test and modulation in the off-vertical axis rotation test. 2. Eleven of 20 laser group patients have shown significant improvement in VAS and THI compared to those of the control group. Conclusions: 1. LLL therapy may have preventive effect to vestibular ototoxicity. 2. LLL therapy in combination with ginkgo biloba seems to be worth trying on patients with tinnitus.

  9. Distribution of efferent cholinergic terminals and alpha-bungarotoxin binding to putative nicotinic acetylcholine receptors in the human vestibular end-organs.

    PubMed

    Ishiyama, A; Lopez, I; Wackym, P A

    1995-11-01

    Although acetylcholine (ACh) has been identified as the primary neurotransmitter of the efferent vestibular system in most animals studied, no direct evidence exists that ACh is the efferent neurotransmitter of the human vestibular system. Choline acetyltransferase immunohistochemistry (ChATi), acetylcholinesterase (AChE) histochemistry, and alpha-bungarotoxin binding were used in human vestibular end-organs to address this question. ChATi and AChE activity was found in numerous bouton-type terminals contacting the basal area of type II vestibular hair cells and the afferent chalices surrounding type I hair cells; alpha-bungarotoxin binding suggested the presence of nicotinic acetylcholine receptors on type II vestibular hair cells and on the afferent chalices surrounding type I hair cells. This study provides evidence that the human efferent vestibular axons and terminals are cholinergic and that the receptors receiving this innervation may be nicotinic.

  10. Multisensory Integration of Visual and Vestibular Signals Improves Heading Discrimination in the Presence of a Moving Object

    PubMed Central

    Dokka, Kalpana; DeAngelis, Gregory C.

    2015-01-01

    Humans and animals are fairly accurate in judging their direction of self-motion (i.e., heading) from optic flow when moving through a stationary environment. However, an object moving independently in the world alters the optic flow field and may bias heading perception if the visual system cannot dissociate object motion from self-motion. We investigated whether adding vestibular self-motion signals to optic flow enhances the accuracy of heading judgments in the presence of a moving object. Macaque monkeys were trained to report their heading (leftward or rightward relative to straight-forward) when self-motion was specified by vestibular, visual, or combined visual-vestibular signals, while viewing a display in which an object moved independently in the (virtual) world. The moving object induced significant biases in perceived heading when self-motion was signaled by either visual or vestibular cues alone. However, this bias was greatly reduced when visual and vestibular cues together signaled self-motion. In addition, multisensory heading discrimination thresholds measured in the presence of a moving object were largely consistent with the predictions of an optimal cue integration strategy. These findings demonstrate that multisensory cues facilitate the perceptual dissociation of self-motion and object motion, consistent with computational work that suggests that an appropriate decoding of multisensory visual-vestibular neurons can estimate heading while discounting the effects of object motion. SIGNIFICANCE STATEMENT Objects that move independently in the world alter the optic flow field and can induce errors in perceiving the direction of self-motion (heading). We show that adding vestibular (inertial) self-motion signals to optic flow almost completely eliminates the errors in perceived heading induced by an independently moving object. Furthermore, this increased accuracy occurs without a substantial loss in the precision. Our results thus demonstrate that

  11. Lack of effects of astemizole on vestibular ocular reflex, motion sickness, and cognitive performance in man

    NASA Technical Reports Server (NTRS)

    Kohl, Randall L.; Homick, Jerry L.; Cintron, Nitza; Calkins, Dick S.

    1987-01-01

    Astemizole was orally administered to 20 subjects in a randomized, double-blind design to assess the efficacy of this peripherally active antihistamine as an antimotion sickness drug possessing no central side-effects. Measures of vestibular ocular reflex (VOR) were made to evaluate the agent as a selective vestibular depressant. Following one week of orally administered astemizole (30 mg daily), a Staircase Profile Test, a VOR test, and a variety of tests of cognitive performance were administered. These tests revealed no statistically significant effects of astemizole. This leads to the conclusion that, although the drug probably reaches the peripheral vestibular apparatus in man by crossing the blood-vestibular barrier, a selective peripheral antihistamine (H1) action is inadequate to control motion sickness induced through cross-coupled accelerative semicircular canal stimulation in a rotating chair.

  12. A versatile stereoscopic visual display system for vestibular and oculomotor research.

    PubMed

    Kramer, P D; Roberts, D C; Shelhamer, M; Zee, D S

    1998-01-01

    Testing of the vestibular system requires a vestibular stimulus (motion) and/or a visual stimulus. We have developed a versatile, low cost, stereoscopic visual display system, using "virtual reality" (VR) technology. The display system can produce images for each eye that correspond to targets at any virtual distance relative to the subject, and so require the appropriate ocular vergence. We elicited smooth pursuit, "stare" optokinetic nystagmus (OKN) and after-nystagmus (OKAN), vergence for targets at various distances, and short-term adaptation of the vestibulo-ocular reflex (VOR), using both conventional methods and the stereoscopic display. Pursuit, OKN, and OKAN were comparable with both methods. When used with a vestibular stimulus, VR induced appropriate adaptive changes of the phase and gain of the angular VOR. In addition, using the VR display system and a human linear acceleration sled, we adapted the phase of the linear VOR. The VR-based stimulus system not only offers an alternative to more cumbersome means of stimulating the visual system in vestibular experiments, it also can produce visual stimuli that would otherwise be impractical or impossible. Our techniques provide images without the latencies encountered in most VR systems. Its inherent versatility allows it to be useful in several different types of experiments, and because it is software driven it can be quickly adapted to provide a new stimulus. These two factors allow VR to provide considerable savings in time and money, as well as flexibility in developing experimental paradigms.

  13. A modified intranasal endoscopic excision for nasal vestibular cyst in China.

    PubMed

    Huang, Zizhen; Li, Jingjia; Yang, Qintai; Li, Peng; Ye, Jin; Liu, Xian; Zhang, Gehua

    2015-03-01

    This study aimed to improve the surgical removal procedure for nasal vestibular cysts. Twenty-three patients with nasal vestibular cysts underwent surgical removal of the cyst via a transoral sublabial approach and another 30 patients via a modified intranasal endoscopic excision method. The 30 patients were treated with local anesthesia and the roof of the cyst, which was firmly attached to the mucous membrane of the anterior floor of the nasal cavity, was removed transnasally with microdebrider. Bleeding of the opening was stopped by electric coagulation without nasal packing. Among the 30 consecutive patients who underwent the modified surgical procedure, all patients were successfully treated. The mean duration of surgery was 5.7 ± 2.6 min. The mean estimated blood loss was 3.5 ± 2.1 ml. All patients were outpatients. The mean hospital stay was 1 h. The mean total cost was 140. The visual analog scale scores of postoperative pain, pressure and nasal obstruction were 1, 0 and 1, respectively. The incidence rate of postoperative lip swelling or numbness was 0 %. Postoperative endoscopic findings revealed that the cyst was replaced by an air-containing sinus with a persistent opening at the anterolateral nasal floor. There was no recurrence during a mean follow-up of 18 months. The modified intranasal endoscopic excision is a simple, less invasive, low-cost and effective surgical procedure for the treatment of nasal vestibular cysts. It might change the pattern of treatment for nasal vestibular cysts in China.

  14. Effects of vestibular rehabilitation on gait performance in poststroke patients: a pilot randomized controlled trial.

    PubMed

    Mitsutake, Tsubasa; Sakamoto, Maiko; Ueta, Kozo; Oka, Shinichiro; Horikawa, Etsuo

    2017-09-01

    The effects of vestibular rehabilitation on poststroke patients are unknown. This study aimed to investigate whether or not vestibular rehabilitation would improve both the vestibulo-ocular reflex and gait performance of patients with poststroke hemiparesis. Twenty-eight patients with stroke were assigned randomly to either an experimental group (N=14) or a control group (N=14). The experimental group performed the conventional physical therapy for 40 min and vestibular rehabilitation for 20 min, as a 60 min session, during the first 3 weeks and then completed only the conventional intervention for 60 min for the following 3 weeks. The control group performed only the 60 min conventional physical therapy for 6 weeks. Both groups were measured using the gaze stabilization test, the 10 m walking test, the timed up and go test, and the dynamic gait index. Patients were assessed at baseline, and at 3 and 6 weeks. Although the control group showed no significant difference in any outcome measures, the experimental group showed an improvement in gaze stabilization test scoring, which increased significantly after 3 weeks compared with the baseline (P=0.030). The dynamic gait index was also significantly increased after 3 and 6 weeks compared with the baseline (P=0.049 and 0.024, respectively). This study indicated that vestibular rehabilitation might improve poststroke patients' vestibulo-ocular reflex. Moreover, patients might show improved gait performance at least up to 3 weeks after the vestibular intervention by the sensory reweight to coordinate vestibular input.

  15. Are Covert Saccade Functionally Relevant in Vestibular Hypofunction?

    PubMed

    Hermann, R; Pelisson, D; Dumas, O; Urquizar, Ch; Truy, E; Tilikete, C

    2018-06-01

    The vestibulo-ocular reflex maintains gaze stabilization during angular or linear head accelerations, allowing adequate dynamic visual acuity. In case of bilateral vestibular hypofunction, patients use saccades to compensate for the reduced vestibulo-ocular reflex function, with covert saccades occurring even during the head displacement. In this study, we questioned whether covert saccades help maintain dynamic visual acuity, and evaluated which characteristic of these saccades are the most relevant to improve visual function. We prospectively included 18 patients with chronic bilateral vestibular hypofunction. Subjects underwent evaluation of dynamic visual acuity in the horizontal plane as well as video recording of their head and eye positions during horizontal head impulse tests in both directions (36 ears tested). Frequency, latency, consistency of covert saccade initiation, and gain of covert saccades as well as residual vestibulo-ocular reflex gain were calculated. We found no correlation between residual vestibulo-ocular reflex gain and dynamic visual acuity. Dynamic visual acuity performance was however positively correlated with the frequency and gain of covert saccades and negatively correlated with covert saccade latency. There was no correlation between consistency of covert saccade initiation and dynamic visual acuity. Even though gaze stabilization in space during covert saccades might be of very short duration, these refixation saccades seem to improve vision in patients with bilateral vestibular hypofunction during angular head impulses. These findings emphasize the need for specific rehabilitation technics that favor the triggering of covert saccades. The physiological origin of covert saccades is discussed.

  16. Visual-Vestibular Conflict Detection Depends on Fixation.

    PubMed

    Garzorz, Isabelle T; MacNeilage, Paul R

    2017-09-25

    Visual and vestibular signals are the primary sources of sensory information for self-motion. Conflict among these signals can be seriously debilitating, resulting in vertigo [1], inappropriate postural responses [2], and motion, simulator, or cyber sickness [3-8]. Despite this significance, the mechanisms mediating conflict detection are poorly understood. Here we model conflict detection simply as crossmodal discrimination with benchmark performance limited by variabilities of the signals being compared. In a series of psychophysical experiments conducted in a virtual reality motion simulator, we measure these variabilities and assess conflict detection relative to this benchmark. We also examine the impact of eye movements on visual-vestibular conflict detection. In one condition, observers fixate a point that is stationary in the simulated visual environment by rotating the eyes opposite head rotation, thereby nulling retinal image motion. In another condition, eye movement is artificially minimized via fixation of a head-fixed fixation point, thereby maximizing retinal image motion. Visual-vestibular integration performance is also measured, similar to previous studies [9-12]. We observe that there is a tradeoff between integration and conflict detection that is mediated by eye movements. Minimizing eye movements by fixating a head-fixed target leads to optimal integration but highly impaired conflict detection. Minimizing retinal motion by fixating a scene-fixed target improves conflict detection at the cost of impaired integration performance. The common tendency to fixate scene-fixed targets during self-motion [13] may indicate that conflict detection is typically a higher priority than the increase in precision of self-motion estimation that is obtained through integration. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Eye instability induced by vestibular stimulation in rabbits.

    PubMed

    Ferraresi, A; Azzena, G B; Troiani, D

    2001-07-03

    The slow compensatory phases of the vestibulo-ocular reflex (VOR) in the rabbit tend to drift and the drift reverses the direction. This periodic alternating drift (PAD) has two peculiar characteristics: (1) it is induced by sinusoidal vestibular stimulation in naive animals, being evoked immediately after stimulus onset and persisting after the end of stimulation; (2) the peak velocity and period of the drift are dependent on stimulus amplitude. PAD of the rabbit has strong similarities with PAN, a periodic alternating nystagmus observed in humans with cerbellar disorders and in monkeys after nodulo-uvulectomy, although its peak velocity is smaller. It is hypothesized that PAD is due to a slight instability, caused by vestibular stimulation in darkness, of the cerebellar adaptive loop, which exerts a variable gain control on the time constant of the velocity storage integrator.

  18. Vestibular-evoked myogenic potentials, clinical evaluation, and imaging findings in multiple sclerosis.

    PubMed

    Güven, Hayat; Bayır, Omer; Aytaç, Emrah; Ozdek, Ali; Comoğlu, Selim Selçuk; Korkmaz, Hakan

    2014-02-01

    Vestibular-evoked myogenic potentials (VEMP), short-latency electromyographic responses elicited by acoustic stimuli, evaluate the function of vestibulocollic reflex and may give information about brainstem function. The aim of the present study is to evaluate the potential contribution of VEMP to the diagnosis of multiple sclerosis (MS). Fifty patients with MS and 30 healthy control subjects were included in this study. The frequency of VEMP p1-n1 and n2-p2 waves; mean p1, n1, n2, and p2 latency; and mean p1-n1 and n2-p2 amplitude were determined. The relation between clinical and imaging findings and VEMP parameters was evaluated. The p1-n1 and n2-p2 waves were more frequently absent in MS than in control subjects [p1-n1 wave absent: MS, 25 (25 %) ears; control, 6 (10 %) ears; P ≤ 0.02] [n2-p2 wave absent: MS, 44 (44 %) ears; control, 7 (12 %) ears; P ≤ 0.001]. The mean p1-n1 amplitude was lower in MS than in control subjects (MS, 19.1 ± 7.2 μV; control, 23.3 ± 7.4 μV; P ≤ 0.002). A total of 24/50 (48 %) MS patients had VEMP abnormalities (absent responses and/or prolonged latencies). VEMP abnormalities were more frequent in patients with than without vestibular symptoms (P ≤ 0.02) and with brainstem functional system score (FSS) ≥ 1 than FSS = 0 (P ≤ 0.02). In patients with MS, absence of p1-n1 wave was more frequent in patients with than without vestibular symptoms [absence of p1-n1 wave: vestibular symptoms, 9 (45 %) ears; no vestibular symptoms, 16 (20 %) ears; P ≤ 0.03] and patients with Expanded Disability Status Scale (EDSS) score ≥ 5.5 [absence of p1-n1 wave: EDSS ≥ 5.5, 7 (70 %) ears; EDSS <5.5, 18 (20 %) ears; P ≤ 0.001]. Abnormal VEMP may be noted in MS patients, especially those with vestibular symptoms and greater disability. The VEMP test may complement other studies for diagnosis and follow-up of patients with MS.

  19. Functional Imaging of Human Vestibular Cortex Activity Elicited by Skull Tap and Auditory Tone Burst

    NASA Technical Reports Server (NTRS)

    Noohi, Fatemeh; Kinnaird, Catherine; Wood, Scott; Bloomberg, Jacob; Mulavara, Ajitkumar; Seidler, Rachael

    2014-01-01

    The aim of the current study was to characterize the brain activation in response to two modes of vestibular stimulation: skull tap and auditory tone burst. The auditory tone burst has been used in previous studies to elicit saccular Vestibular Evoked Myogenic Potentials (VEMP) (Colebatch & Halmagyi 1992; Colebatch et al. 1994). Some researchers have reported that airconducted skull tap elicits both saccular and utricle VEMPs, while being faster and less irritating for the subjects (Curthoys et al. 2009, Wackym et al., 2012). However, it is not clear whether the skull tap and auditory tone burst elicit the same pattern of cortical activity. Both forms of stimulation target the otolith response, which provides a measurement of vestibular function independent from semicircular canals. This is of high importance for studying the vestibular disorders related to otolith deficits. Previous imaging studies have documented activity in the anterior and posterior insula, superior temporal gyrus, inferior parietal lobule, pre and post central gyri, inferior frontal gyrus, and the anterior cingulate cortex in response to different modes of vestibular stimulation (Bottini et al., 1994; Dieterich et al., 2003; Emri et al., 2003; Schlindwein et al., 2008; Janzen et al., 2008). Here we hypothesized that the skull tap elicits the similar pattern of cortical activity as the auditory tone burst. Subjects put on a set of MR compatible skull tappers and headphones inside the 3T GE scanner, while lying in supine position, with eyes closed. All subjects received both forms of the stimulation, however, the order of stimulation with auditory tone burst and air-conducted skull tap was counterbalanced across subjects. Pneumatically powered skull tappers were placed bilaterally on the cheekbones. The vibration of the cheekbone was transmitted to the vestibular cortex, resulting in vestibular response (Halmagyi et al., 1995). Auditory tone bursts were also delivered for comparison. To validate

  20. [Effects of electromagnetic fields emitted by cellular phone on auditory and vestibular labyrinth].

    PubMed

    Sievert, U; Eggert, S; Goltz, S; Pau, H W

    2007-04-01

    It is the subject of this study to investigate the biological effect of the HF radiation produced by the Global System for Mobile Communications-( GSM)-mobile phone on the inner ear with its sensors of the vestibular and auditive systems. Thermographic investigations made on various model materials and on the human temporal bone should show whether mobile phone does induce any increases of temperature which would lead to a relevant stimulus for the auditive and vestibular system or not. We carried out video-nystagmographic recordings of 13 subjects, brainstem electric response audiometry of 24 ears, and recordings of distorsion products of otoacoustic emissions of 20 ears. All tests were made with and without a mobile phone in use. The data was then analyzed for variation patterns in the functional parameters of the hearing and balance system that are subject to the (non)existence of electromagnetic radiation from the mobile phone. The thermographic investigations suggest that the mobile phone does not induce any increases of temperature which would lead to a relevant stimulus for the auditive and vestibular system. Video-nystagmographic recordings under field effect do not furnish any indication of vestibular reactions generated by field effects. Compared with the recording without field, the brainstem electric response audiometry under field effect did not reveal any changes of the parameters investigated, i. e. absolute latency of the peaks I, III, V and the interpeak latency between the peaks I and V. The distorsion products of otoacoustic emissions do not indicate, comparing the three measuring situations, i. e. before field effect, pulsed field and continuous field, any possible impacts of the HF field on the spectrum or levels of emissions for none of the probands. The investigations made show that the electromagnetic fields generated in using the mobile phone do not have an effect on the inner ear and auditive system to the colliculus inferior in the

  1. Acquired intolerance to organic solvents and results of vestibular testing

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

    Gyntelberg, F.; Vesterhauge, S.; Fog, P.

    1986-01-01

    Among 160 consecutive patients referred to the Clinic of Occupational Medicine, Rigshospitalet, for symptoms connected with exposure to organic solvents, 20 exhibited symptoms of acquired intolerance to minor amounts of organic solvents. Later, an additional 30 consecutive patients with symptoms of acquired intolerance were included, yielding a total of 43 men and 7 women. The characteristics of the clinical syndrome described are complaints of dizziness, nausea, and weakness after exposure to minimal solvent vapor concentrations. After having tolerated long-term occupational exposure to moderate or high air concentrations of various organic solvents, the patients became intolerant within a short period ofmore » time. Since dizziness was a frequent complaint, we tried to obtain a measure of the patients' complaints using vestibular tests. As a diagnostic test the combined vestibular tests had a sensitivity of 0.55 and a specificity of 0.87. No differences between patients with and without intolerance could be detected by the vestibular tests used. We conclude that acquired intolerance to organic solvents is a new but characteristic and easily recognizable syndrome, often with severe consequences for the patient's working ability.« less

  2. Post-spaceflight orthostatic intolerance: possible relationship to microgravity-induced plasticity in the vestibular system

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

    Even after short spaceflights, most astronauts experience at least some postflight reduction of orthostatic tolerance; this problem is severe in some subjects. The mechanisms leading to postflight orthostatic intolerance are not well-established, but have traditionally been thought to include the following: changes in leg hemodynamics, alterations in baroreceptor reflex gain, decreases in exercise tolerance and aerobic fitness, hypovolemia, and altered sensitivity of beta-adrenergic receptors in the periphery. Recent studies have demonstrated that signals from vestibular otolith organs play an important role in regulating blood pressure during changes in posture in a 1-g environment. Because spaceflight results in plastic changes in the vestibular otolith organs and in the processing of inputs from otolith receptors, it is possible that another contributing factor to postflight orthostatic hypotension is alterations in the gain of vestibular influences on cardiovascular control. Preliminary data support this hypothesis, although controlled studies will be required to determine the relationship between changes in the vestibular system and orthostatic hypotension following exposure to microgravity. Copyright 1998 Elsevier Science B.V.

  3. Generalization of vestibular learning to earth-fixed targets is possible but limited when the polarity of afferent vestibular information is changed.

    PubMed

    Mackrous, I; Simoneau, M

    2014-02-28

    To maintain perception of the world around us during body motion, the brain must update the spatial presentation of visual stimuli, known as space updating. Previous studies have demonstrated that vestibular signals contribute to space updating. Nonetheless, when being passively rotated in the dark, the ability to keep track of a memorized earth-fixed target (EFT) involves learning mechanism(s). We tested whether such learning generalizes across different EFT eccentricities. Furthermore, we ascertained whether learning transfers to similar target eccentricities but in the opposite direction. Participants were trained to predict the position of an EFT (located at 45° to their left) while being rotated counterclockwise (i.e., they press a push button when they perceived that their body midline have cross the position of the target). Overall, the results indicated that learning transferred to other target eccentricity (30° and 60°) for identical body rotation direction. In contrast, vestibular learning partly transferred to target location's matching body rotation but in the opposite rotation direction. Generalization of learning implies that participants do not adopt cognitive strategies to improve their performance during training. We argue that the brain learned to use vestibular signals for space updating. Generalization of learning while being rotated in the opposite direction implies that some parts of the neural networks involved in space updating is shared between trained and untrained direction. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

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

    PubMed Central

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

    2014-01-01

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

  5. Vestibular Migraine in Children and Adolescents: Clinical Findings and Laboratory Tests

    PubMed Central

    Langhagen, Thyra; Lehrer, Nicole; Borggraefe, Ingo; Heinen, Florian; Jahn, Klaus

    2015-01-01

    Introduction: Vestibular migraine (VM) is the most common cause of episodic vertigo in children. We summarize the clinical findings and laboratory test results in a cohort of children and adolescents with VM. We discuss the limitations of current classification criteria for dizzy children. Methods: A retrospective chart analysis was performed on 118 children with migraine related vertigo at a tertiary care center. Patients were grouped in the following categories: (1) definite vestibular migraine (dVM); (2) probable vestibular migraine (pVM); (3) suspected vestibular migraine (sVM); (4) benign paroxysmal vertigo (BPV); and (5) migraine with/without aura (oM) plus vertigo/dizziness according to the International Classification of Headache Disorders, 3rd edition (beta version). Results: The mean age of all patients was 12 ± 3 years (range 3–18 years, 70 females). 36 patients (30%) fulfilled criteria for dVM, 33 (28%) for pVM, 34 (29%) for sVM, 7 (6%) for BPV, and 8 (7%) for oM. Somatoform vertigo (SV) co-occurred in 27% of patients. Episodic syndromes were reported in 8%; the family history of migraine was positive in 65%. Mild central ocular motor signs were found in 24% (most frequently horizontal saccadic pursuit). Laboratory tests showed that about 20% had pathological function of the horizontal vestibulo-ocular reflex, and almost 50% had abnormal postural sway patterns. Conclusion: Patients with definite, probable, and suspected VM do not differ in the frequency of ocular motor, vestibular, or postural abnormalities. VM is the best explanation for their symptoms. It is essential to establish diagnostic criteria in clinical studies. In clinical practice, however, the most reasonable diagnosis should be made in order to begin treatment. Such a procedure also minimizes the fear of the parents and children, reduces the need to interrupt leisure time and school activities, and prevents the development of SV. PMID:25674076

  6. 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.

  7. Interrelated striated elements in vestibular hair cells of the rat

    NASA Technical Reports Server (NTRS)

    Ross, M. D.; Bourne, C.

    1983-01-01

    A series of interrelated striated organelles in types I and II vestibular hair cells of the rat which appear to be less developed in cochlear hair cells have been revealed by unusual fixation procedures, suggesting that contractile elements may play a role in sensory transduction in the inner ear, especially in the vestibular system. Included in the series of interrelated striated elements are the cuticular plate and its basal attachments to the hair cell margins, the connections of the strut array of the kinociliary basal body to the cuticular plate, and striated organelles associated with the plasma membrane and extending below the apical junctional complexes.

  8. Vestibular evoked myogenic potential (VEMP) in patients with acoustic neuromas.

    PubMed

    Takeichi, N; Sakamoto, T; Fukuda, S; Inuyama, Y

    2001-05-01

    To study the utility of VEMP (vestibular-evoked myogenic potential) in the diagnosis of acoustic neuromas. Eighteen patients with unilateral acoustic neuromas were subjected to this study. Myogenic potential responding to loud click stimuli was recorded at ipsilateral sternocleidomastoid muscle. A normal range of VEMP was obtained from 20 controls. VEMP responses were compared with both, clinical symptoms and results of caloric tests. Thirteen out of 18 patients showed decreased responses of VEMP at the affected side. VEMP responses seemed to have little relation with dysequilibrium, spontaneous nystagmus, canal paresis and pure-tone hearing. VEMP is useful for detecting dysfunction of inferior vestibular nerve in patients with acoustic neuromas.

  9. Vestibular thalamus: Two distinct graviceptive pathways.

    PubMed

    Baier, Bernhard; Conrad, Julian; Stephan, Thomas; Kirsch, Valerie; Vogt, Thomas; Wilting, Janine; Müller-Forell, Wibke; Dieterich, Marianne

    2016-01-12

    To determine whether there are distinct thalamic regions statistically associated with either contraversive or ipsiversive disturbance of verticality perception measured by subjective visual vertical (SVV). We used modern statistical lesion behavior mapping on a sample of 37 stroke patients with isolated thalamic lesions to clarify which thalamic regions are involved in graviceptive otolith processing and whether there are distinct regions associated with contraversive or ipsiversive SVV deviation. We found 2 distinct systems of graviceptive processing within the thalamus. Contraversive tilt of SVV was associated with lesions to the nuclei dorsomedialis, intralamellaris, centrales thalami, posterior thalami, ventrooralis internus, ventrointermedii, ventrocaudales and superior parts of the nuclei parafascicularis thalami. The regions associated with ipsiversive tilt of SVV were located in more inferior regions, involving structures such as the nuclei endymalis thalami, inferior parts of the nuclei parafascicularis thalami, and also small parts of the junction zone of the nuclei ruber tegmenti and brachium conjunctivum. Our data indicate that there are 2 anatomically distinct graviceptive signal processing mechanisms within the vestibular network in humans that lead, when damaged, to a vestibular tone imbalance either to the contraversive or to the ipsiversive side. © 2015 American Academy of Neurology.

  10. 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.

  11. 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

  12. 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

  13. BRN 3.1 Knockouts Affect the Vestibular, Autonomic, and Circadian Rhythm Responses to 2G Exposure

    NASA Technical Reports Server (NTRS)

    Murakami, D. M.; Erkman, L.; Rosenfeld, M. G.; Fuller, C. A.

    1999-01-01

    Our previous studies have demonstrated that 2G exposure via centrifugation significantly attenuated the daily mean and circadian rhythm amplitude of rat body temperature (Tb), heart rate, and activity (Act). In addition, 2G exposure activates neural responses in several vestibular, autonomic, and circadian nuclei. Although we have characterized the effect of 2G on an animal's physiological, neuronal, and behavioral responses, it will be important to understand the underlying neural and physiological mechanisms that mediate those responses. For example, the vestibular responses, proprioceptive feedback, or fluid shifts may be the critical factors that mediate the responses to 2G. As a first step to understand the relative importance of these different response pathways to altered gravitational fields, this study examined the contribution of the vestibular system by utilizing an animal model from molecular biology. Brain 3.1 (Bm 3.1) is a POU domain homeobox gene involved in the normal development of the vestibular and auditory system. Brn 3.1 deletion results in a loss of hair cells in the otoliths, semicircular canals, and cochlea. As a result mice with a Brn 3.1 deletion do not have a functioning vestibular or auditory system. The BRN 3.1 knockout mouse could be a very useful animal model for isolating the role of the vestibular system in mediating the physiological responses to 2G exposure. Therefore, this study compared the effect of 2G exposure via centrifugation between Brn 3.1 knockout (KO) versus Wildtype (W) mice.

  14. 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

  15. The contribution of visual and vestibular information to spatial orientation by 6- to 14-month-old infants and adults.

    PubMed

    Bremner, J Gavin; Hatton, Fran; Foster, Kirsty A; Mason, Uschi

    2011-09-01

    Although there is much research on infants' ability to orient in space, little is known regarding the information they use to do so. This research uses a rotating room to evaluate the relative contribution of visual and vestibular information to location of a target following bodily rotation. Adults responded precisely on the basis of visual flow information. Seven-month-olds responded mostly on the basis of visual flow, whereas 9-month-olds responded mostly on the basis of vestibular information, and 12-month-olds responded mostly on the basis of visual information. Unlike adults, infants of all ages showed partial influence by both modalities. Additionally, 7-month-olds were capable of using vestibular information when there was no visual information for movement or stability, and 9-month-olds still relied on vestibular information when visual information was enhanced. These results are discussed in the context of neuroscientific evidence regarding visual-vestibular interaction, and in relation to possible changes in reliance on visual and vestibular information following acquisition of locomotion. © 2011 Blackwell Publishing Ltd.

  16. Problems of space biology. Volume 50: Nystagmometry for evaulation of the status of the vestibular function

    NASA Technical Reports Server (NTRS)

    Levashov, M. M.; Kislyakov, V. A. (Editor)

    1985-01-01

    Various aspects of nystagmometry are studied, primarily those in which the study of hystagmus serves as a means to learn about the vestibular apparatus. Along with exhaustive published material, the monograph presents data from many years of research on the physioloigical mechanisms of nystagmus, the features of nystagmus when vestibular stimulation is combined with optokinetic, the pole of vertibular afferentation asymmetry in the asymmetry of reactions to optokinetic stimulus, a nystagmometric approach to studying the hydrodynamic interaction among semicircular canals, as well as several other questions. A great deal of attention is given to methods of recording nystagmus, calibrating nystagmograms, quantitative evaluation of nystagmographic material, new nystagmometric characteristics and diagnostic techniques. A diagnostic model is proposed which makes it possible to obtain important information on the condition of the vestibular system from results of vestibular testing.

  17. 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

  18. Computational fluid dynamics simulation of pressure and velocity distribution inside Meniere’s diseased vestibular system

    NASA Astrophysics Data System (ADS)

    Shamsuddin, N. F. H.; Isa, N. M.; Taib, I.; Mohammed, A. N.

    2017-09-01

    Meniere’s disease or known as endolymphatic hydrops is an incurable vestibular disorder of the inner ear. This is due to the excessive fluid build-up in the endolymphatic sac which causing the vestibular endolymphatic membrane to start stretching. Although this mechanism has been widely accepted as the likely mechanism of Meniere’s syndrome, the reason for its occurrence remains unclear. Thus, the aims of this study to investigate the critical parameters of fluid flow in membranous labyrinth that is influencing instability of vestibular system. In addition, to visualise the flow behaviour between a normal membranous labyrinth and dilated membranous labyrinth in Meniere’s disease in predicting instability of vestibular system. Three dimensional geometry of endolymphatic sac is obtained from Magnetic Resonance Images (MRI) and reconstructed using commercial software. As basis of comparison the two different model of endolymphatic sac is considered in this study which are normal membranous labyrinth for model I and dilated membranous labyrinth for model II. Computational fluid dynamics (CFD) method is used to analyse the behaviour of pressure and velocity flow in the endolymphatic sac. The comparison was made in terms of pressure distribution and velocity profile. The results show that the pressure for dilated membranous labyrinth is greater than normal membranous labyrinth. Due to abnormally pressure in the vestibular system, it leads to the increasing value of the velocity at dilated membranous labyrinth while at the normal membranous labyrinth the velocity values decreasing. As a conclusion by changing the parameters which is pressure and velocity can significantly affect to the instability of vestibular system for Meniere’s disease.

  19. Coding of Velocity Storage in the Vestibular Nuclei.

    PubMed

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

    2017-01-01

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

  20. Coding of Velocity Storage in the Vestibular Nuclei

    PubMed Central

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

    2017-01-01

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

  1. 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.

  2. Role of the medial medullary reticular formation in relaying vestibular signals to the diaphragm and abdominal muscles

    NASA Technical Reports Server (NTRS)

    Mori, R. L.; Bergsman, A. E.; Holmes, M. J.; Yates, B. J.

    2001-01-01

    Changes in posture can affect the resting length of respiratory muscles, requiring alterations in the activity of these muscles if ventilation is to be unaffected. Recent studies have shown that the vestibular system contributes to altering respiratory muscle activity during movement and changes in posture. Furthermore, anatomical studies have demonstrated that many bulbospinal neurons in the medial medullary reticular formation (MRF) provide inputs to phrenic and abdominal motoneurons; because this region of the reticular formation receives substantial vestibular and other movement-related input, it seems likely that medial medullary reticulospinal neurons could adjust the activity of respiratory motoneurons during postural alterations. The objective of the present study was to determine whether functional lesions of the MRF affect inspiratory and expiratory muscle responses to activation of the vestibular system. Lidocaine or muscimol injections into the MRF produced a large increase in diaphragm and abdominal muscle responses to vestibular stimulation. These vestibulo-respiratory responses were eliminated following subsequent chemical blockade of descending pathways in the lateral medulla. However, inactivation of pathways coursing through the lateral medulla eliminated excitatory, but not inhibitory, components of vestibulo-respiratory responses. The simplest explanation for these data is that MRF neurons that receive input from the vestibular nuclei make inhibitory connections with diaphragm and abdominal motoneurons, whereas a pathway that courses laterally in the caudal medulla provides excitatory vestibular inputs to these motoneurons.

  3. Recovery from Spatial Neglect with Intra- and Transhemispheric Functional Connectivity Changes in Vestibular and Visual Cortex Areas-A Case Study.

    PubMed

    Conrad, Julian; Boegle, Rainer; Ertl, Matthias; Brandt, Thomas; Dieterich, Marianne

    2018-01-01

    Vestibular signals are involved in higher cortical functions like spatial orientation and its disorders. Vestibular dysfunction contributes, for example, to spatial neglect which can be transiently improved by caloric stimulation. The exact roles and mechanisms of the vestibular and visual systems for the recovery of neglect are not yet known. Resting-state functional connectivity (fc) magnetic resonance imaging was recorded in a patient with hemispatial neglect during the acute phase and after recovery 6 months later following a right middle cerebral artery infarction before and after caloric vestibular stimulation. Seeds in the vestibular [parietal operculum (OP2)], the parietal [posterior parietal cortex (PPC); 7A, hIP3], and the visual cortex (VC) were used for the analysis. During the acute stage after caloric stimulation the fc of the right OP2 to the left OP2, the anterior cingulum, and the para/hippocampus was increased bilaterally (i.e., the vestibular network), while the interhemispheric fc was reduced between homologous regions in the VC. After 6 months, similar fc increases in the vestibular network were found without stimulation. In addition, fc increases of the OP2 to the PPC and the VC were seen; interhemispherically this was true for both PPCs and for the right PPC to both VCs. Improvement of neglect after caloric stimulation in the acute phase was associated with increased fc of vestibular cortex areas in both hemispheres to the para-hippocampus and the dorsal anterior cingulum, but simultaneously with reduced interhemispheric VC connectivity. This disclosed a, to some extent, similar but also distinct short-term mechanism (vestibular stimulation) of an improvement of spatial orientation compared to the long-term recovery of neglect.

  4. Assessing Readability and Reliability of Online Patient Information Regarding Vestibular Schwannoma.

    PubMed

    Spiers, Harry; Amin, Nikul; Lakhani, Raj; Martin, Andrew J; Patel, Parag M

    2017-12-01

    The aim of this study is to objectively assess the quality and readability of websites related to vestibular schwannomas. Patients are increasingly seeking information on confirmed or suspected diagnoses through the Internet. Clinicians are often concerned regarding the accuracy, quality, and readability of web-based sites. Online information relating to vestibular schwannoma was searched using the three most popular search engines. The terms "acoustic neuroma" and "vestibular schwannoma" were used. The top 50 results from each site were assessed for readability using the Flesch-Kincaid Grade Level, Flesch Reading Ease Score, and the Gunning-Fog Index. Quality of website information was scored using the DISCERN tool. Of 300 search results analyzed, 58 separate appropriate websites were identified. The mean readability score using Flesch-Kincaid Grade Level was 10.27 (95% confidence interval [CI] 9.84-10.70). The mean Flesch Reading Ease Score was 48.75 (95% CI 46.57-50.92). The Gunning-Fog Index was 13.40 (95% CI 12.92-13.89). These scores equate to someone finishing secondary school/first year university student. DISCERN scores were highly variable but consistently demonstrated great variability in quality of information. Online patient information on vestibular schwannoma is highly variable in quality. Although there are a wide range of different websites easily available to patients on their condition and its treatment options, the information is written at a difficult level which may exceed the understanding level of many patients as it is written at a higher than average level of expected reading ability.

  5. Vestibular control of standing balance is enhanced with increased cognitive load.

    PubMed

    McGeehan, Michael A; Woollacott, Marjorie H; Dalton, Brian H

    2017-04-01

    When cognitive load is elevated during a motor task, cortical inhibition and reaction time are increased; yet, standing balance control is often unchanged. This disconnect is likely explained by compensatory mechanisms within the balance system such as increased sensitivity of the vestibulomotor pathway. This study aimed to determine the effects of increased cognitive load on the vestibular control of standing balance. Participants stood blindfolded on a force plate with their head facing left and arms relaxed at their sides for two trials while exposed to continuous electrical vestibular stimulation (EVS). Participants either stood quietly or executed a cognitive task (double-digit arithmetic). Surface electromyography (EMG) and anterior-posterior ground-body forces (APF) were measured in order to evaluate vestibular-evoked balance responses in the frequency (coherence and gain) and time (cumulant density) domains. Total distance traveled for anterior-posterior center of pressure (COP) was assessed as a metric of balance variability. Despite similar distances traveled for COP, EVS-medial gastrocnemius (MG) EMG and EVS-APF coherence and EVS-TA EMG and EVS-MG EMG gain were elevated for multiple frequencies when standing with increased cognitive load. For the time domain, medium-latency peak amplitudes increased by 13-54% for EVS-APF and EVS-EMG relationships with the cognitive task compared to without. Peak short-latency amplitudes were unchanged. These results indicate that reliance on vestibular control of balance is enhanced when cognitive load is elevated. This augmented neural strategy may act to supplement divided cortical processing resources within the balance system and compensate for the acute neuromuscular modifications associated with increased cognitive demand.

  6. 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.

  7. Allicin protects against cisplatin-induced vestibular dysfunction by inhibiting the apoptotic pathway.

    PubMed

    Wu, Xianmin; Cai, Jing; Li, Xiaofei; Li, He; Li, Jianfeng; Bai, Xiaohui; Liu, Wenwen; Han, Yuechen; Xu, Lei; Zhang, Daogong; Wang, Haibo; Fan, Zhaomin

    2017-06-15

    Cisplatin is an anticancer drug that causes the impairment of inner ear function as side effects, including hearing loss and balance dysfunction. The purpose of this study was to investigate the effects of allicin against cisplatin-induced vestibular dysfunction in mice and to make clear the mechanism underlying the protective effects of allicin on oto-vestibulotoxicity. Mice intraperitoneally injected with cisplatin exhibited vestibular dysfunction in swimming test, which agreed with impairment in vestibule. However, these impairments were significantly prevented by pre-treatment with allicin. Allicin markedly reduced cisplatin-activated expression of cleaved-caspase-3 in hair cells and vascular layer cells of utricule, saccule and ampulla, but also decreased AIF nuclear translocation of hair cells in utricule, saccule and ampulla. These results showed that allicin played an effective role in protecting vestibular dysfunction induced by cisplatin via inhibiting caspase-dependent and caspase-independent apoptotic pathways. Therefore, allicin may be useful in preventing oto-vestibulotoxicity mediated by cisplatin. Copyright © 2017. Published by Elsevier B.V.

  8. The cortical spatiotemporal correlate of otolith stimulation: Vestibular evoked potentials by body translations.

    PubMed

    Ertl, M; Moser, M; Boegle, R; Conrad, J; Zu Eulenburg, P; Dieterich, M

    2017-07-15

    The vestibular organ senses linear and rotational acceleration of the head during active and passive motion. These signals are necessary for bipedal locomotion, navigation, the coordination of eye and head movements in 3D space. The temporal dynamics of vestibular processing in cortical structures have hardly been studied in humans, let alone with natural stimulation. The aim was to investigate the cortical vestibular network related to natural otolith stimulation using a hexapod motion platform. We conducted two experiments, 1. to estimate the sources of the vestibular evoked potentials (VestEPs) by means of distributed source localization (n=49), and 2. to reveal modulations of the VestEPs through the underlying acceleration intensity (n=24). For both experiments subjects were accelerated along the main axis (left/right, up/down, fore/aft) while the EEG was recorded. We were able to identify five VestEPs (P1, N1, P2, N2, P3) with latencies between 38 and 461 ms as well as an evoked beta-band response peaking with a latency of 68 ms in all subjects and for all acceleration directions. Source localization gave the cingulate sulcus visual (CSv) area and the opercular-insular region as the main origin of the evoked potentials. No lateralization effects due to handedness could be observed. In the second experiment, area CSv was shown to be integral in the processing of acceleration intensities as sensed by the otolith organs, hinting at its potential role in ego-motion detection. These robust VestEPs could be used to investigate the mechanisms of inter-regional interaction in the natural context of vestibular processing and multisensory integration. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Vestibular short-latency evoked potential abolished by low-frequency noise exposure in rats.

    PubMed

    Stewart, Courtney E; Kanicki, Ariane C; Altschuler, Richard A; King, W M

    2018-02-01

    The vestibular system plays a critical role in detection of head movements and is essential for normal postural control. Because of their anatomical proximity to the cochlea, the otolith organs are selectively exposed to sound pressure and are at risk for noise overstimulation. Clinical reports suggest a link between noise exposure and balance problems, but the structural and physiological basis for this linkage is not well understood. The goal of this study was to determine the effects of low-frequency noise (LFN) on the otolith organs by correlating changes in vestibular short-latency evoked potentials (VsEPs) with changes in saccular afferent endings following noise exposure. LFN exposure transiently abolished the VsEP and reduced the number of stained calyces within the sacculus. Although some recovery of the VsEP waveform could be observed within 3 days after noise, at 3 wk recovery was only partial in most animals, consistent with a reduced number of afferents with calyceal endings. These data show that a single intense noise exposure is capable of causing a vestibular deficit that appears to mirror the synaptic deficit associated with hidden hearing loss after noise-induced cochlear injury. NEW & NOTEWORTHY This is the first study to explore the effects of low-frequency high-intensity noise on vestibular short-latency evoked potential (VsEP) responses, which shows a linkage between attenuated noise-induced VsEPs and pathological changes to otolith organ afferents. This finding suggests a potential limitation of the VsEP for evaluation of vestibular dysfunction, since the VsEP measurement may assess the activity of a specific class rather than all afferents.

  10. 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).

  11. 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.

  12. Relationship between endolymphatic hydrops and vestibular-evoked myogenic potential.

    PubMed

    Katayama, Naomi; Yamamoto, Masako; Teranishi, Masaaki; Naganawa, Shinji; Nakata, Seiichi; Sone, Michihiko; Nakashima, Tsutomu

    2010-08-01

    Vestibular-evoked myogenic potential (VEMP) can be used to examine endolymphatic hydrops, especially in the vestibule. To investigate the relationship between the degree of endolymphatic hydrops revealed by magnetic resonance imaging (MRI) and VEMP. Gadolinium diluted with saline was injected intratympanically in 49 ears (40 patients). One day after the injection, the endolymphatic space in the vestibule and the cochlea was visualized by 3 Tesla MRI. A VEMP test was done, and VEMP was judged as absent when the VEMP was within the noise level. VEMP was present in 21 ears and absent in 28 ears. Endolymphatic hydrops was significantly associated with the disappearance of VEMP. Endolymphatic hydrops in the vestibule had a stronger effect than endolymphatic hydrops in the cochlea. Five patients with extremely large vestibular hydrops showed no response of VEMP.

  13. Research on biophysical evaluation of the human vestibular system

    NASA Technical Reports Server (NTRS)

    Young, L. R.

    1974-01-01

    The human vestibular function was studied by the combined approach of advanced measurement and mathematical modelling. Fundamental measurements of some physical properties of endolymph and perilymph, combined with nystagmus measurements and fluid mechanical analysis of semicircular canal function furthered the theory of canal mechanical response to angular acceleration, caloric stimulation and relating linear acceleration. The effects of adaptation seen at low frequency angular stimulation were studied and modelled to remove some shortcomings of the torsion pendulum models. Otolith function was also studied experimentally and analytically, leading to a new set of models for subjective orientation. Applications to special problems of space, including the case of rotating spacecraft were investigated and the interaction of visual and vestibular cues and their relation to proprioceptive information was explored relative to postural control.

  14. Reporting success rates in the treatment of vestibular schwannomas: are we accounting for the natural history?

    PubMed

    Miller, Timothy; Lau, Tsz; Vasan, Rohit; Danner, Christopher; Youssef, A Samy; van Loveren, Harry; Agazzi, Siviero

    2014-06-01

    Stereotactic radiosurgery is generally accepted as one of the best treatment options for vestibular schwannomas. We question whether growth control is an accurate measure of success in vestibular schwannoma treatment. We aim to clarify the success rate of stereotactic radiosurgery and adjust the reported results to the benign natural history of untreated tumors. All articles were taken from a PubMed search of the English literature from the years 2000-2011. Inclusion criteria were articles containing the number of patients treated, radiation technique, average tumor size, follow-up time, and percentage of tumors growing during follow-up. Data were extracted from 19 articles. Success rates were adjusted using published data that 17% to 30% of vestibular schwannomas grow. The average reported success rate for stereotactic radiosurgery across all articles was 95.5%. When considering 17% or 30% natural growth without intervention, the adjusted success rates became 78.2% and 86.9% respectively. These rates were obtained by applying the natural history growth percentages to any tumors not reported to be growing before radiosurgical intervention. Success in the treatment of vestibular schwannomas with stereotactic radiosurgery is often defined as lack of further growth. Recent data on the natural growth history of vestibular schwannomas raise the question of whether this is the best definition of success. We have identified a lack of continuity regarding the reporting of success and emphasize the importance of the clarification of the success of radiosurgery to make informed decisions regarding the best treatment options for vestibular schwannoma. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Personality traits modulate subcortical and cortical vestibular and anxiety responses to sound-evoked otolithic receptor stimulation.

    PubMed

    Indovina, Iole; Riccelli, Roberta; Staab, Jeffrey P; Lacquaniti, Francesco; Passamonti, Luca

    2014-11-01

    Strong links between anxiety, space-motion perception, and vestibular symptoms have been recognized for decades. These connections may extend to anxiety-related personality traits. Psychophysical studies showed that high trait anxiety affected postural control and visual scanning strategies under stress. Neuroticism and introversion were identified as risk factors for chronic subjective dizziness (CSD), a common psychosomatic syndrome. This study examined possible relationships between personality traits and activity in brain vestibular networks for the first time using functional magnetic resonance imaging (fMRI). Twenty-six right-handed healthy individuals underwent fMRI during sound-evoked vestibular stimulation. Regional brain activity and functional connectivity measures were correlated with personality traits of the Five Factor Model (neuroticism, extraversion-introversion, openness, agreeableness, consciousness). Neuroticism correlated positively with activity in the pons, vestibulo-cerebellum, and para-striate cortex, and negatively with activity in the supra-marginal gyrus. Neuroticism also correlated positively with connectivity between pons and amygdala, vestibulo-cerebellum and amygdala, inferior frontal gyrus and supra-marginal gyrus, and inferior frontal gyrus and para-striate cortex. Introversion correlated positively with amygdala activity and negatively with connectivity between amygdala and inferior frontal gyrus. Neuroticism and introversion correlated with activity and connectivity in cortical and subcortical vestibular, visual, and anxiety systems during vestibular stimulation. These personality-related changes in brain activity may represent neural correlates of threat sensitivity in posture and gaze control mechanisms in normal individuals. They also may reflect risk factors for anxiety-related morbidity in patients with vestibular disorders, including previously observed associations of neuroticism and introversion with CSD. Copyright

  16. Representation of visual gravitational motion in the human vestibular cortex.

    PubMed

    Indovina, Iole; Maffei, Vincenzo; Bosco, Gianfranco; Zago, Myrka; Macaluso, Emiliano; Lacquaniti, Francesco

    2005-04-15

    How do we perceive the visual motion of objects that are accelerated by gravity? We propose that, because vision is poorly sensitive to accelerations, an internal model that calculates the effects of gravity is derived from graviceptive information, is stored in the vestibular cortex, and is activated by visual motion that appears to be coherent with natural gravity. The acceleration of visual targets was manipulated while brain activity was measured using functional magnetic resonance imaging. In agreement with the internal model hypothesis, we found that the vestibular network was selectively engaged when acceleration was consistent with natural gravity. These findings demonstrate that predictive mechanisms of physical laws of motion are represented in the human brain.

  17. 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

  18. Advances in Oculomotor and Vestibular Physiology

    DTIC Science & Technology

    1980-11-24

    and nucleus reticularis tegmenti pontis in serving as an input to the flocculus and in mediating visual-vestibular interactions. Karten showed direct...demonstrated that the region in an around the Interstitial Nucleus of Cajal is important for the generation of torsional or rolling eye movements. 3...demonstrated that activity related to full field motion reaches the flocculus of mammals over mossy fiber Lnpits that arise from cells in nucleus

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

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  20. 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.