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Sample records for vestibular function including

  1. Vestibular function testing.

    LENUS (Irish Health Repository)

    Lang, E E

    2010-06-01

    Vestibular symptoms of vertigo, dizziness and dysequilibrium are common complaints which can be disabling both physically and psychologically. Routine examination of the ear nose and throat and neurological system are often normal in these patients. An accurate history and thorough clinical examination can provide a diagnosis in the majority of patients. However, in a subgroup of patients, vestibular function testing may be invaluable in arriving at a correct diagnosis and ultimately in the optimal treatment of these patients.

  2. Dyscalculia and vestibular function.

    Science.gov (United States)

    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.

  3. Perspectives on aging vestibular function

    Directory of Open Access Journals (Sweden)

    Eric eAnson

    2016-01-01

    Full Text Available Much is known about age related anatomical changes in the vestibular system. Knowledge regarding how vestibular anatomical changes impact behavior for older adults continues to grow, in line with advancements in diagnostic testing. However, despite advancements in clinical diagnostics, much remains unknown about the functional impact that an aging vestibular system has on daily life activities like standing and walking. Modern diagnostic tests are very good at characterizing neural activity of the isolated vestibular system, but the tests themselves are artificial and do not reflect the multi-sensory aspects of natural human behavior. Also, the majority of clinical diagnostic tests are passively applied because active behavior can enhance performance. In this perspective paper we review anatomical and behavioral changes associated with an aging vestibular system and highlight several areas where a more functionally relevant perspective can be taken. For postural control, a multi-sensory perturbation approach could be used to bring balance rehabilitation into the arena of precision medicine. For walking and complex gaze stability, this may result in less physiologically specific impairments, but the trade-off would be a greater understanding of how the aging vestibular system truly impacts the daily life of older adults.

  4. Vestibular Function and Activities of Daily Living

    Directory of Open Access Journals (Sweden)

    Aisha Harun MD

    2015-09-01

    Full Text Available Objective: Vestibular dysfunction increases with age and is associated with mobility difficulties and fall risk in older individuals. We evaluated whether vestibular function influences the ability to perform activities of daily living (ADLs. Method: We analyzed the 1999 to 2004 National Health and Nutrition Examination Survey of adults aged older than 40 years ( N = 5,017. Vestibular function was assessed with the Modified Romberg test. We evaluated the association between vestibular function and difficulty level in performing specific basic and instrumental ADLs, and total number of ADL impairments. Results: Vestibular dysfunction was associated with significantly higher odds of difficulty with nine ADLs, most strongly with difficulty managing finances (odds ratio [ OR ] = 2.64, 95% confidence interval [CI] = [1.18, 5.90]. In addition, vestibular dysfunction was associated with a significantly greater number of ADL impairments (β = .21, 95% CI = [0.09, 0.33]. This effect size was comparable with the influence of heavy smoking (β = .21, 95% CI = [0.06, 0.36] and hypertension (β = .10, 95% CI = [0.02, 0.18] on the number of ADL impairments. Conclusion: Vestibular dysfunction significantly influences ADL difficulty, most strongly with a cognitive rather than mobility-based task. These findings underscore the importance of vestibular inputs for both cognitive and physical daily activities.

  5. Vestibular Function in Adults With Epilepsy of Unknown Etiology.

    Science.gov (United States)

    Hamed, Sherifa A; Tohamy, Amal M; Oseilly, Amira M

    2017-09-01

    This study aimed to evaluate vestibular function in adults with chronic epilepsy of unknown etiology in the inter-ictal period. Epilepsy is a chronic medical disorder. Life-long therapy may be required in one-third of patients. Epilepsy is associated with comorbid somatic conditions which impairs patients' quality of life. This cross-sectional study included 28 with generalized tonic clonic (GTC) convulsions and 14 and 3 with temporal (TLE) and frontal lobe (FLE) epilepsies with secondary generalization (all were on regular carbamazepine therapy) and 40 healthy control subjects. The patients' mean age was 34.97 ± 7.35 years and the duration of illness was 18.75 ± 7.99 years. All underwent videonystagmography (VNG). Compared with controls, patients had frequent vestibular symptoms including dizziness (62.22%) (p = 0.0001) and sense of imbalance (44.44%) (p = 0.0001). Eleven patients (24.44%) had central vestibular dysfunction (p = 0.0001); 9 (20%) had mixed vestibular dysfunction and one (2.22%) had peripheral vestibular dysfunction (p = 0.0001). Abnormalities were observed in saccadic (44.4%) and pursuit (42.2%) eye movements, optokinetic nystagmus (42.2%) and positioning/positional (11.11%) and caloric (13.33%) testing. TLE and FLE were associated with more VNG abnormalities than GTC. No significant differences were observed in the demographic and clinical characteristics between patients with and without VNG abnormalities. Vestibular manifestations are frequent in patients with epilepsy. This may be a result of the permanent damaging effect of chronic epilepsy on the vestibular cortical areas and/or a toxic effect from prolonged carbamazepine therapy on the peripheral and central vestibular systems.

  6. Vestibular Function Impairment in Alzheimer's Disease.

    Science.gov (United States)

    Nakamagoe, Kiyotaka; Fujimiya, Suguru; Koganezawa, Tadachika; Kadono, Kotarou; Shimizu, Kotone; Fujizuka, Natsu; Takiguchi, Shino; Ueno, Tomoyuki; Monzen, Tatsuya; Tamaoka, Akira

    2015-01-01

    Falls and fractures due to impaired balance in patients with Alzheimer's disease (AD) have an adverse effect on the clinical course of the disease. To evaluate balance impairment in AD from the viewpoint of vestibular functional impairment. The subjects were 12 patients with AD, 12 dementia-free elderly adults, and 12 younger adults. Vestibular function was assessed using a stepping test, caloric nystagmus, and a visual suppression (VS) test. The stepping test was abnormal in 9 of the 12 patients in the AD group. An abnormal stepping test was not associated with self-reported dizziness or tendency to fall. Significant VS abnormalities were present in the AD group. The suppression rate of VS was lower in AD patients with either a tendency to fall or constructional apraxia than in AD patients without either. The velocity of the rapid phase of caloric nystagmus before the VS test was similar in the AD group and the elderly control group. Significant abnormalities of both caloric nystagmus and VS were not present in either the elderly or the younger control groups. AD could involve impairments in the vestibular control of balance. The VS test is useful for assessing the tendency to fall in AD. Impairment of VS in AD might arise from cerebral vestibular cortex impairment rather than comorbid peripheral vestibular disorders.

  7. Improving Sensorimotor Function Using Stochastic Vestibular Stimulation

    Science.gov (United States)

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

    2014-01-01

    Astronauts experience sensorimotor changes during spaceflight, particularly during G-transition phases. Post flight sensorimotor changes may include postural and gait instability, spatial disorientation, and visual performance decrements, all of which can degrade operational capabilities of the astronauts and endanger the crew. Crewmember safety would be improved if these detrimental effects of spaceflight could be mitigated by a sensorimotor countermeasure and even further if adaptation to baseline could be facilitated. 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 performance through stochastic resonance (SR). The SR phenomenon occurs when the response of a nonlinear system to a weak input signal is optimized by the application of a particular nonzero level of noise. Two studies have been initiated to investigate the beneficial effects and potential practical usage of SVS. In both studies, electrical vestibular stimulation is applied via electrodes on the mastoid processes using a constant current stimulator. The first study aims to determine the repeatability of the effect of vestibular stimulation on sensorimotor performance and perception in order to better understand the practical use of SVS. The beneficial effect of low levels of SVS on balance performance has been shown in the past. This research uses the same balance task repeated multiple times within a day and across days to study the repeatability of the stimulation effects. The balance test consists of 50 sec trials in which the subject stands with his or her feet together, arms crossed, and eyes closed on compliant foam. Varying levels of SVS, ranging from 0-700 micro A, are applied across different trials. The subject-specific optimal SVS level is that which results in the best balance performance as measured by inertial

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

    Science.gov (United States)

    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.

  9. Audiovestibular Function Deficits in Vestibular Schwannoma

    Directory of Open Access Journals (Sweden)

    Constantin von Kirschbaum

    2016-01-01

    Full Text Available Introduction. Vestibular schwannomas (VS are benign tumours of the vestibular nerve and can lead to hearing loss, tinnitus, vertigo, facial palsy, and brainstem compression. Audiovestibular diagnostic tests are essential for detection and treatment planning. Methods. Medline was used to perform a systematic literature review with regard to how audiovestibular test parameters correlate with symptoms, tumour size, and tumour location. Results. The auditory brainstem response can be used to diagnose retrocochlear lesions caused by VS. Since hearing loss correlates poorly with tumour size, a retrocochlear lesion is probably not the only cause for hearing loss. Also cochlear mechanisms seem to play a role. This can be revealed by abnormal otoacoustic emissions, despite normal ABR and new MRI techniques which have demonstrated endolymphatic hydrops of the inner ear. Caloric and head impulse tests show frequency specific dynamics and vestibular evoked myogenic potentials may help to identify the location of the tumour regarding the involved nerve parts. Conclusion. In order to preserve audiovestibular function in VS, it is important to stop the growth of the tumour and to avoid degenerative changes in the inner ear. A detailed neurotological workup helps to diagnose VS of all sizes and can also provide useful prognostic information.

  10. Vestibular function in the space environment

    Science.gov (United States)

    Von Baumgarten, R. J.; Harth, O.; Thuemler, R.; Baldrighi, G.; Shillinger, G. L., Jr.

    1975-01-01

    The present work presents new results about the interdependence of optical illusory sensations and eye movements in man. To establish to what degree certain illusions previously obtained during centrifugation and parabolic flight can be explained by eye movements and by neuronal integration in the brain, real eye movements were measured as they occurred in the dark without optical fixation, during rectilinear accelerations on the ground, and during weightlessness in parabolic flight. Results provide valuable insight into normal vestibular function as well as resolution of within-the-eye and behind-the-eye contributions to the above illusions.

  11. Assessment of auditory and vestibular functions in vitiligo patients

    Directory of Open Access Journals (Sweden)

    Eman Abd Elmohsin Dawoud

    2017-09-01

    Conclusion: The results in this study showed that 50% of vitiligo patients suffered from peripheral vestibular disorders in addition to auditory affection. Vitiligo patients require routine monitoring for auditory and vestibular functions for early identification and monitoring of changes as the disease progress.

  12. Are Covert Saccade Functionally Relevant in Vestibular Hypofunction?

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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 30).

  14. [The changes in vestibular function in patients with diabetes mellitus and its clinical significance].

    Science.gov (United States)

    Li, Juan; Zhang, Tianyu; Shen, Jianzhong; Gong, Jingrong; Wang, Hongli; Zhang, Jimin; Pang, Yufeng

    2008-01-01

    To study the changes of vestibular function in patients with diabetes mellitus and its clinical significance. Electronystagmography (ENG) was used to examine 76 patients with diabetes mellitus and 60 healthy adults subjects. After clinical detection of vestibular function including spontaneous nystagmus, positional test, head shaking nystagmus, neck torsion test, caloric test, and sensory organization tests which consist of gaze, saccade and smooth pursuit test, the results of these two groups were recorded for qualitative and quantitative statistical analysis. The rate of vestibular dysfunction in patients with diabetes mellitus were 68.4%. and that of the controls were 8.3%. There was significant difference between these two groups (chi2 = 15.472, P Vertigo or dizziness occurred in patients with diabetes mellitus might be related to vestibular dysfunction. ENG test could be used as one of the objective clinical examinations in patients with diabetes mellitus.

  15. Age-related decline in functional connectivity of the vestibular cortical network.

    Science.gov (United States)

    Cyran, Carolin Anna Maria; Boegle, Rainer; Stephan, Thomas; Dieterich, Marianne; Glasauer, Stefan

    2016-04-01

    In the elderly, major complaints include dizziness and an increasing number of falls, possibly related to an altered processing of vestibular sensory input. In this study, we therefore investigate age-related changes induced by processing of vestibular sensory stimulation. While previous functional imaging studies of healthy aging have investigated brain function during task performance or at rest, we used galvanic vestibular stimulation during functional MRI in a task-free sensory stimulation paradigm to study the effect of healthy aging on central vestibular processing, which might only become apparent during stimulation processing. Since aging may affect signatures of brain function beyond the BOLD-signal amplitude-such as functional connectivity or temporal signal variability--we employed independent component analysis and partial least squares analysis of temporal signal variability. We tested for age-associated changes unrelated to vestibular processing, using a motor paradigm, voxel-based morphometry and diffusion tensor imaging. This allows us to control for general age-related modifications, possibly originating from vascular, atrophic or structural connectivity changes. Age-correlated decreases of functional connectivity and increases of BOLD--signal variability were associated with multisensory vestibular networks. In contrast, no age-related functional connectivity changes were detected in somatosensory networks or during the motor paradigm. The functional connectivity decrease was not due to structural changes but to a decrease in response amplitude. In synopsis, our data suggest that both the age-dependent functional connectivity decrease and the variability increase may be due to deteriorating reciprocal cortico-cortical inhibition with age and related to multimodal vestibular integration of sensory inputs.

  16. Influence of cochlear implantation on peripheral vestibular receptor function.

    Science.gov (United States)

    Krause, Eike; Louza, Julia P R; Wechtenbruch, Juliane; Gürkov, Robert

    2010-06-01

    The objectives of this study were 1) to assess the influence of a cochlear implantation on peripheral vestibular receptor function in the inner ear in the implant and in the nonimplant side, and 2) to analyze a possible correlation with resulting vertigo symptoms. Prospective clinical study. Cochlear implant center at tertiary referral hospital. A total of 32 patients, aged 15 to 83 years, undergoing cochlear implantation were assessed pre- and postoperatively for caloric horizontal semicircular canal response and vestibular-evoked myogenic potentials of the sacculus, and postoperatively for subjective vertigo symptoms. Patients with vertigo were compared with patients without symptoms with regard to the findings of the vestibular function tests. Cochlear implantation represents a significant risk factor for horizontal semicircular canal impairment (P 0.05). Cochlear implantation is a relevant risk factor for damage of peripheral vestibular receptor function. Therefore, preservation not only of residual hearing function but also of vestibular function should be aimed for, by using minimally invasive surgical techniques. Copyright 2010 American Academy of Otolaryngology-Head and Neck Surgery Foundation. Published by Mosby, Inc. All rights reserved.

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

    Science.gov (United States)

    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

  18. Improving Sensorimotor Function and Adaptation using Stochastic Vestibular Stimulation

    Science.gov (United States)

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

    2014-01-01

    Astronauts experience sensorimotor changes during adaption to G-transitions that occur when entering and exiting microgravity. Post space flight, these sensorimotor disturbances can include postural and gait instability, visual performance changes, manual control disruptions, spatial disorientation, and motion sickness, all of which can hinder the operational capabilities of the astronauts. Crewmember safety would be significantly increased if sensorimotor changes brought on by gravitational changes could be mitigated and adaptation could be facilitated. The goal of this research is to investigate and develop the use of electrical stochastic vestibular stimulation (SVS) as a countermeasure to augment sensorimotor function and facilitate adaptation. For this project, SVS will be applied via electrodes on the mastoid processes at imperceptible amplitude levels. We hypothesize that SVS will improve sensorimotor performance through the phenomena of stochastic resonance, which occurs when the response of a nonlinear system to a weak input signal is optimized by the application of a particular nonzero level of noise. In line with the theory of stochastic resonance, a specific optimal level of SVS will be found and tested for each subject [1]. Three experiments are planned to investigate the use of SVS in sensory-dependent tasks and performance. The first experiment will aim to demonstrate stochastic resonance in the vestibular system through perception based motion recognition thresholds obtained using a 6-degree of freedom Stewart platform in the Jenks Vestibular Laboratory at Massachusetts Eye and Ear Infirmary. A range of SVS amplitudes will be applied to each subject and the subjectspecific optimal SVS level will be identified as that which results in the lowest motion recognition threshold, through previously established, well developed methods [2,3,4]. The second experiment will investigate the use of optimal SVS in facilitating sensorimotor adaptation to system

  19. Vestibular migraine

    DEFF Research Database (Denmark)

    Lempert, Thomas; Olesen, Jes; Furman, Joseph

    2012-01-01

    This paper presents diagnostic criteria for vestibular migraine, jointly formulated by the Committee for Classification of Vestibular Disorders of the Bárány Society and the Migraine Classification Subcommittee of the International Headache Society (IHS). The classification includes vestibular...... migraine and probable vestibular migraine. Vestibular migraine will appear in an appendix of the third edition of the International Classification of Headache Disorders (ICHD) as a first step for new entities, in accordance with the usual IHS procedures. Probable vestibular migraine may be included...... in a later version of the ICHD, when further evidence has been accumulated. The diagnosis of vestibular migraine is based on recurrent vestibular symptoms, a history of migraine, a temporal association between vestibular symptoms and migraine symptoms and exclusion of other causes of vestibular symptoms...

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

    Science.gov (United States)

    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 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.

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

    Science.gov (United States)

    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. Effects of infrasound on vestibular function

    Science.gov (United States)

    Takigawa, H.; Sakamoto, H.; Murata, M.

    1991-12-01

    The present study was undertaken to elucidate subjective symptoms reported by some individuals exposed to various sounds, including infrasound. Narrow band infrasound of 5 Hz at center frequency and wide octave band audible noise were separately applied at an intensity of 95 dB. Parameters such as involuntary eye movement with the eyes visually fixed, body sway and pulse-wave were investigated. The total amount and power percentage in the low-frequency band of involuntary eye movement was significantly increased upon exposure to infrasound. Furthermore, confusion in postural control at the time of transition from opening to closing of the subject's eyes was inhibited by this exposure. Conversely, pulse-wave height decrement was observed upon exposure to both sounds, although this was smaller in the case of infrasound as compared with that of noise. These findings are taken to indicate that the effects taking place via the two different pathways were mixed in the subjective symptoms, and that functional changes caused by infrasound exposure were unrelated to an emotion stimulated by acoustical sensation.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  5. Stereotactic radiotherapy of vestibular schwannoma. Hearing preservation, vestibular function, and local control following primary and salvage radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Putz, Florian; Mueller, Jan; Wimmer, Caterina; Goerig, Nicole; Knippen, Stefan; Semrau, Sabine; Fietkau, Rainer; Lettmaier, Sebastian [Friedrich-Alexander-University Erlangen-Nuremberg, Department of Radiation Oncology, Erlangen (Germany); Iro, Heinrich; Grundtner, Philipp [Friedrich-Alexander-University Erlangen-Nuremberg, Department of Otorhinolaryngology - Head and Neck Surgery, Erlangen (Germany); Eyuepoglu, Ilker; Roessler, Karl [Friedrich-Alexander-University Erlangen-Nuremberg, Department of Neurosurgery, Erlangen (Germany)

    2017-03-15

    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. (orig.) [German] Praesentation von Langzeitdaten zu funktionellen Ergebnissen und Tumorkontrolle nach stereotaktischer Radiotherapie (RT) in einer Kohorte von 107 Patienten mit Akustikusneurinom. Zwischen Oktober 2002 und Dezember 2013 wurden 107 Patienten mit Akustikusneurinom (primaer oder rezidiviert nach vorangegangener Resektion) mittels stereotaktischer RT behandelt

  6. Vergence and Standing Balance in Subjects with Idiopathic Bilateral Loss of Vestibular Function.

    Directory of Open Access Journals (Sweden)

    Zoï Kapoula

    Full Text Available There is a natural symbiosis between vergence and vestibular responses. Deficits in vergence can lead to vertigo, disequilibrium, and postural instability. This study examines both vergence eye movements in patients with idiopathic bilateral vestibular loss, and their standing balance in relation to vergence. Eleven patients participated in the study and 16 controls. Bilateral loss of vestibular function was objectified with many tests; only patients without significant response to caloric tests, to video head impulse tests and without vestibular evoked myogenic potentials were included in the study.A LED display with targets at 20, 40, and 100 cm along the median plane was used to elicit vergence eye movements, recorded with the IRIS device.Four conditions were run, each lasting 1 min: fixation of a LED at 40 cm (convergence of 9°, at 150 cm (convergence of 2.3°; this last condition was repeated with eyes closed. Comparison of the eyes closed-eyes open conditions at 150 cm allowed evaluation of the Romberg Quotient. In the forth condition, two LEDS, at 20 and at 100 cm, were light on, one after the other for 1 sec, causing the eyes to converge then diverge. Standing balance was recorded with an accelerometer placed at the back near the center of mass (McRoberts, Dynaport.Relative to controls, convergence eye movements in patients showed significantly lower accuracy, lower mean velocity, and saccade intrusions of significantly higher amplitude.The normalized 90% area of body sway was significantly higher for patients than for controls for all conditions. Yet, similarly to controls, postural stability was better while fixating at near (sustained convergence than at far, or while making active vergence movements. We argue that vestibular loss deteriorates convergence, but even deficient, convergence can be helpful for postural control.

  7. Entrainment and phase-shifting by centrifugation abolished in mice lacking functional vestibular input

    Science.gov (United States)

    Fuller, Charles; Ringgold, Kristyn

    The circadian pacemaker can be phase shifted and entrained by appropriately timed locomotor activity, however the mechanism(s) involved remain poorly understood. Recent work in our lab has suggested the involvement of the vestibular otolith organs in activity-induced changes within the circadian timing system (CTS). For example, we have shown that changes in circa-dian period and phase in response to locomotion (wheel running) require functional macular gravity receptors. We believe the neurovestibular system is responsible for the transduction of gravitoinertial input associated with the types of locomotor activity that are known to af-fect the pacemaker. This study investigated the hypothesis that daily, timed gravitoinertial stimuli, as applied by centrifugation. would induce entrainment of circadian rhythms in only those animals with functional afferent vestibular input. To test this hypothesis, , chemically labyrinthectomized (Labx) mice, mice lacking macular vestibular input (head tilt or hets) and wildtype (WT) littermates were implanted i.p. with biotelemetry and individually housed in a 4-meter diameter centrifuge in constant darkness (DD). After 2 weeks in DD, the mice were exposed daily to 2G via centrifugation from 1000-1200 for 9 weeks. Only WT mice showed entrainment to the daily 2G pulse. The 2G pulse was then re-set to occur at 1200-1400 for 4 weeks. Only WT mice demonstrated a phase shift in response to the re-setting of the 2G pulse and subsequent re-entrainment to the new centrifugation schedule. These results provide further evidence that gravitoinertial stimuli require a functional vestibular system to both en-train and phase shift the CTS. Entrainment among only WT mice supports the role of macular gravity receptive cells in modulation of the CTS while also providing a functional mechanism by which gravitoinertial stimuli, including locomotor activity, may affect the pacemaker.

  8. Aging of the Human Vestibular System

    OpenAIRE

    Zalewski, Christopher K.

    2015-01-01

    Aging affects every sensory system in the body, including the vestibular system. Although its impact is often difficult to quantify, the deleterious impact of aging on the vestibular system is serious both medically and economically. The deterioration of the vestibular sensory end organs has been known since the 1970s; however, the measurable impact from these anatomical changes remains elusive. Tests of vestibular function either fall short in their ability to quantify such anatomical deteri...

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

    Science.gov (United States)

    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.

  10. Late radiation effects on hearing, vestibular function, and taste in brain tumor patients

    International Nuclear Information System (INIS)

    Johannesen, Tom B.; Rasmussen, Kjell; Winther, Finn Oe.; Halvorsen, Ulf; Lote, Knut

    2002-01-01

    Purpose: To investigate late radiation effects on hearing, vestibular function, and taste after conventional radiotherapy in brain tumor patients. Methods and Materials: Hearing, vestibular function, and taste were assessed in 33 brain tumor patients irradiated unilaterally to the tumor-bearing hemisphere and the temporal bone. Median observation time after completion of radiotherapy was 13 years; the fraction dose was 1.8 Gy, and mean radiation dose was 53.1 Gy. Results: Deep ulceration in the external ear canal and osteoradionecrosis on the irradiated side was seen in three patients. Reduced hearing was found for air and bone conduction of the irradiated side compared to the opposite side (0.25-2 kHz: 6.1 dB, 4 kHz: 10.3 dB, 6 kHz: 15.6 dB, and 8 kHz: 16.5 dB). For bone conduction, the corresponding figures were 0.25-2 kHz: 5.5 dB and 4 kHz: 8.2 dB. Three patients had a canal paresis of the irradiated side, and three patients had affection of the chorda tympani. Conclusion: Irradiation of the temporal bone with doses usually given in the treatment of patients with brain tumors may cause osteoradionecrosis, sensorineural hearing loss, dysfunction of the vestibular inner ear, and loss of taste. Head-and-neck examination should be included in the follow-up of long-term survivors

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

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

    2013-05-01

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

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

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    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.

  13. Ocular Motor Function in Patients with Bilateral Vestibular Weakness

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    Seyyed Amir Hossein Ghazizadeh Hashemi

    2016-05-01

    Full Text Available Introduction: Patients with bilateral weakness (BW have many difficulties in gaze stability that interfere with their normal function. The aim of this study was to evaluate ocular motor functions in patients with BW to better understand the problem of gaze instability in these patients.   Materials and Methods: Patients were referred from the Otolaryngology Department for Vestibular Assessment to our clinic between November 2014 and March 2015. We assessed ocular motor function (gaze, saccade, and smooth pursuit in patients over the age of 18 years with BW, as verified by a caloric test.   Results: Seventy-eight patients completed all the tests. The mean age of patients was 51.9 (±15.9 years, and 47 (60% were female. Abnormal results were found in five (6.4%, 32 (41%, and seven (9% patients with respect to gaze, smooth pursuit, and saccade, respectively. There were positive but relatively weak relationships between age and ocular motor results.   Conclusion:  Patients with BW suffer from dizziness and unsteadiness. These patients have abnormal function in ocular motor (especially smooth pursuit tests. The ocular motor dysfunction is responsible for gaze instability in static positions such as standing.

  14. The Relationship between Vestibular Function and Topographical Memory in Older Adults

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    Fred Henry Previc

    2014-06-01

    Full Text Available Research during the past two decades has demonstrated an important role of the vestibular system in topographical orientation and memory and the network of neural structures associated with them. Almost all of the supporting data have come from animal or human clinical studies, however. The purpose of the present study was to investigate the link between vestibular function and topographical memory in normal elderly humans. Twenty-five participants aged 70 to 85 years who scored from mildly impaired to normal on the Montreal Cognitive Assessment received three topographical memory tests: the Camden Topographical Recognition Memory Test (CTMRT, a computerized topographical mental rotation test (TMRT, and a virtual pond maze (VPM. They also received six vestibular or oculomotor tests: optokinetic nystagmus (OKN, visual pursuit (VP, actively generated vestibulo-ocular reflex (VOR, the sensory orientation test (SOT for posture, and two measures of rotational memory (error in degrees, or RMº, and correct directional recognition, or RM→. The only significant bivariate correlations were among the three vestibular measures primarily assessing horizontal canal function (VOR, RMº, and RM→. A multiple regression analysis showed significant relationships between vestibular and demographic predictors and both the TMRT (R=.78 and VPM (R=.66 measures. The significant relationship between the vestibular and topographical memory measures supports the theory that vestibular loss may contribute to topographical memory impairment in the elderly.

  15. Preservation of vestibular function after scala vestibuli cochlear implantation.

    Science.gov (United States)

    Suzuki, Mitsuya; Goto, Takio; Kashio, Akinori; Yasui, Takuya; Sakamoto, Takashi; Ito, Ken; Yamasoba, Tatsuya

    2011-10-01

    A 58-year-old man, in whom the cochlear implant (CI) had been inserted into the left ear, had right middle-ear cancer. The CI was removed immediately before receiving subtotal removal of right temporal bone. Four months later, the CI was again inserted in his left cochlea. Because of obliterated scala tympani, the 22 active electrodes of the CI were placed into the scala vestibuli. After the surgery, the patient complained that he experienced rotary vertigo and "jumbling of vertical direction" of objects on walking. Using rotation test, we evaluated vestibular function of remaining left ear. Numerous horizontal nystagmus beats were induced during earth-vertical axis rotation, whereas vertical downbeat nystagmus was scarcely induced during off-vertical axis rotation. The horizontal vestibulo-ocular reflex (VOR) was almost normally induced by sinusoidal stimulation at 0.8Hz. These data suggest that the scala vestibuli insertion of CI would be not so invasive against the lateral semicircular canal. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

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

    OpenAIRE

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

    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 chang...

  17. The development of vestibular system and related function in mammals: Impact of gravity

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    Marc eJamon

    2014-02-01

    Full Text Available This chapter reviews the knowledge about the adaptation to Earth gravity during the development of mammals. The impact of early exposure to altered gravity is evaluated at the level of the functions related to the vestibular system, including postural control, homeostatic regulation, and spatial memory. The hypothesis of critical periods in the adaptation to gravity is discussed. Demonstrating a critical period requires removing the gravity stimulus during delimited time windows, what is impossible to do on Earth surface. The Surgical destruction of the vestibular apparatus, and the use of mice strains with defective graviceptors have provided useful information on the consequences of missing gravity perception, and the possible compensatory mechanisms, but transitory suppression of the stimulus can only be operated during spatial flight. The rare studies on rat pups housed on board of space shuttle significantly contributed to this problem, but the use of hypergravity environment, produced by means of chronic centrifugation, is the only available tool when repeated experiments must be carried out on Earth. Even though hypergravity is sometimes considered as a mirror situation to microgravity, the two situations cannot be confused because a gravitational force is still present. The theoretical considerations that validate the paradigm of hypergravity to evaluate critical periods are discussed. The question of adaption of graviceptor is questioned from an evolutionary point of view. It is possible that graviception is hardwired, because life on Earth has evolved under the constant pressure of gravity. The rapid acquisition of motor programming by precocial mammals in minutes after birth is consistent with this hypothesis, but the slow development of motor skills in altricial species and the plasticity of vestibular perception in adults suggest that gravity experience is required for the tuning of graviceptors. The possible reasons for this

  18. Functional Plasticity after Unilateral Vestibular Midbrain Infarction in Human Positron Emission Tomography

    Science.gov (United States)

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

    2016-01-01

    The aim of the study was to uncover mechanisms of central compensation of vestibular function at brainstem, cerebellar, and cortical levels in patients with acute unilateral midbrain infarctions presenting with an acute vestibular tone imbalance. Eight out of 17 patients with unilateral midbrain infarctions were selected on the basis of signs of a vestibular tone imbalance, e.g., graviceptive (tilts of perceived verticality) and oculomotor dysfunction (skew deviation, ocular torsion) in F18-fluordeoxyglucose (FDG)-PET at two time points: A) in the acute stage, and B) after recovery 6 months later. Lesion-behavior mapping analyses with MRI verified the exact structural lesion sites. Group subtraction analyses and comparisons with healthy controls were performed with Statistic Parametric Mapping for the PET data. A comparison of PET A of acute-stage patients with that of healthy controls showed increases in glucose metabolism in the cerebellum, motion-sensitive visual cortex areas, and inferior temporal lobe, but none in vestibular cortex areas. At the supratentorial level bilateral signal decreases dominated in the thalamus, frontal eye fields, and anterior cingulum. These decreases persisted after clinical recovery in contrast to the increases. The transient activations can be attributed to ocular motor and postural recovery (cerebellum) and sensory substitution of vestibular function for motion perception (visual cortex). The persisting deactivation in the thalamic nuclei and frontal eye fields allows alternative functional interpretations of the thalamic nuclei: either a disconnection of ascending sensory input occurs or there is a functional mismatch between expected and actual vestibular activity. Our data support the view that both thalami operate separately for each hemisphere but receive vestibular input from ipsilateral and contralateral midbrain integration centers. Normally they have gatekeeper functions for multisensory input to the cortex and automatic

  19. Insertional Mutagenesis for Genes involved in Otic/Vestibular Development and Function in Xenopus Tropicalis

    Science.gov (United States)

    Torrejon, Marcela; Li, Erica; Nguyen, Minh; Winfree, Seth; Wang, Esther; Reinsch, Sigrid; Dalton, Bonnie (Technical Monitor)

    2002-01-01

    Sensitivity to gravity is essential for spatial orientation. Consequently, the gravity receptor system is one of the phylogenetically oldest sensory systems, and the special adaptations that enhance sensitivity to gravity are highly conserved. The main goal of this project is to use Xenopus (frog) to identify genes expressed during vestibular and auditory development. These studies will lead a better understanding of the molecular mechanisms involved in vestibular and auditory development and function. We are using a gene-trap approach in Xenopus tropicalis with the green fluorescent protein (GFP) gene as the transgene reporter. GFP expression occurs only when the GFP gene is correctly integrated in actively transcribed genes. Using the GFP as a tag we can easily identify and clone the mutated gene. In addition, we can study the function of the mutated gene by analyzing the defects generated by insertion of the GFP transgene. To date we have tissue specific GFP expression in X. tropicalis including expression in ear, neural tube, kidney, muscle, eyes and nose. Our transgenic animals will soon reach maturity so that we can outcross them and analyze their progeny. Our next goal is to isolate RNA from our transgenics and clone the tagged genes using RACE-PCR. Currently we are optimizing the RACE-PCR method using transgenics with crystallin GFP expression.

  20. Functional balance associated factors in the elderly with chronic vestibular disorder.

    Science.gov (United States)

    Gazzola, Juliana Maria; Perracini, Monica Rodrigues; Ganança, Maurício Malavasi; Ganança, Fernando Freitas

    2006-01-01

    Daily activities can be challenging for the elderly. To study the association between functional balance, evaluated by the Berg Balance Scale (BBS), sociodemographics, clinical and mobilility (Timed up and go test-TUGT, Dynamic Gait Index-DGI) variables in the elderly with chronic vestibular disorder. A series study with one hundred and twenty elderly with chronic vestibular disorder. We performed the Mann-Whitney test, the Kruskal-Wallis test followed by Dunn test and the Spearman Coefficient ([FORMULA: SEE TEXT]). Statistically significant associations and correlations were observed between total BBS score and age ([FORMULA: SEE TEXT]=-0.354; pfalls (p=0.010), tendency to fall (p=0.002), topographic diagnosis of central vestibular disorder (pFunctional balance in the elderly with chronic vestibular disorders evaluated by the BBS is worse when associated with aging, with a more advanced age group (80 years or more), increasing number of illnesses, presence of five or more illnesses, use of multiple medications, recurrent falls, tendency to fall, central vestibular syndromes, daily dizziness, mobility and gait impairments.

  1. Correlation between the body balance and functional capacity from elderly with chronic vestibular disorders.

    Science.gov (United States)

    Sousa, Raquel Ferreira de; Gazzola, Juliana Maria; Ganança, Maurício Malavasi; Paulino, Célia Aparecida

    2011-01-01

    Vestibular disorders are common among the elderly, mainly resulting in dizziness and imbalance--symptoms which can impact daily routine activities. To study the correlation between body balance and functional capacity and a comparison of risk of falls, actual falls and the functional capacity of the elderly with chronic vestibular dysfunctions. A cross-sectional, clinical and experimental study with 50 senior citizens--60 to 86 years, with chronic peripheral vestibular dysfunction. These participants underwent body balance assessment by the Dynamic Gait Index (DGI) and functional capacity assessment by the Functional Independence Measure (FIM). The data was tested using the Spearman correlation and comparison tests, Mann-Whitney and Kruskal-Wallis, being α=5% (0.05). There was a significant correlation between the total DGI score and all FIM scores, especially the total score (r=0.447; pfunctional capacity in elderly patients with the highest risk of falling (pfunctional capacity in elderly patients with peripheral vestibular disorders, that is: the better the balance, the better the individual's functional capacity. In addition, a worse functional capacity increases the individual's risk of falling.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  5. The effects of hypergravity and substrate vibration on vestibular function in developing chickens.

    Science.gov (United States)

    Jones, S M; Warren, L E; Shukla, R; Browning, A; Fuller, C A; Jones, T A

    2000-12-01

    We used linear vestibular evoked potentials (VsEPs) to characterize peripheral and central vestibular function in birds following embryogenesis at 2G centrifugation or at elevated levels of vibration (+20dB re: background levels). Additionally, we characterized peripheral and central vestibular adaptation to 2G centrifugation in early post-hatch birds. Linear VsEP response peak latencies, amplitudes, thresholds and input/output functions were quantified and compared between experimental and control animals. Birds vibrated throughout embryogenesis and up to one-week post-hatch revealed no changes in linear VsEP response components compared to control siblings. Birds centrifuged at 2G throughout embryogenesis also evidenced no changes in the linear VsEP measured at hatch (P0). Significant changes were seen, however, for linear VsEPs of post-hatch birds placed at 2G for 7 days beginning on post-hatch day 5. Linear VsEPs for these animals displayed significant reductions in response amplitudes associated with peaks P2, N2 and P3, response peaks generated by central neural relays of gravity receptors. The earliest response components, generated by the peripheral vestibular nerve (i.e., P1, N1), were not significantly altered with the 7-day exposure to 2G. Thus, there was no evidence of generalized changes in peripheral gravity receptor excitability or in the rate of maturation in developing animals under increased levels of gravity or vibration. If gravity level plays a critical role in shaping peripheral vestibular ontogeny at magnitudes between 1 and 2G, then it may serve to stabilize function under changing G-fields or it may operate on physiological features that can not be resolved by the VsEP. In contrast, exposure to elevated gravity during post-hatch periods does alter central vestibular function thus providing direct evidence for central vestibular adaptation to the gravitational environment. The fact that central functional change was observed in hatchlings

  6. [The significance of directional preponderance in the evaluation of vestibular function in patients with vertigo].

    Science.gov (United States)

    Wang, J; Zhou, Y J; Yu, J; Gu, J

    2017-03-07

    Objective: To analyze the relationship between directional preponderance (DP), spontaneous nystagmus(SN) and vestibular disorders, and to investigate the significance of DP in directing peripheral vestibular function in patients with vertigo. Methods: This was a retrospective analysis of 394 cases diagnosed with peripheral vestibular disease accompanied by vertigo from March 2012 to June 2014 in the Outpatient Department of the Eye & ENT Hospital of Fudan University. Results of static and dynamic posture equilibrium tests, SN, unilateral weakness(UW), and DP in videonystagmography(VNG) were analyzed and compared. Results: The mean interval time between the last vertigo attack and examination in patients with SN or DP in caloric test were 4.4 d and 7.3 d respectively, and those without SN or DP were 18.3 d and 17.5 d respectively. The patients were divided into two groups according to DP results of caloric test. DP-normal group had 203 cases and DP-abnormal group had 191 cases. Spontaneous nystagmus was presented in 44 cases in the DP-normal group (21.67%) and four in the DP-abnormal group (2.09%). A significant difference was found between the two groups (χ 2 =35.27, P =0.000). Deficiency of vestibular function was noted in 165 cases in the DP-normal group (81.28%) and 123 (64.40%) in the DP-abnormal group in static and dynamic posture equilibrium tests. The difference between the two groups was statistically significant (χ 2 =14.26, P =0.000). Conclusion: Compared with DP-normal patients, DP-abnormal patients are more likely to have spontaneous nystagmus and balance disorders due to vestibular dysfunction.

  7. Pesquisa da função vestibular em crianças com queixa de dificuldades escolares Vestibular function in children underperforming at school

    Directory of Open Access Journals (Sweden)

    Eloisa Sartori Franco

    2008-12-01

    Full Text Available O aprendizado é um processo complexo, dinâmico, estruturado a partir de um ato motor e perceptivo, que, elaborado corticalmente, dá origem à cognição. O equilíbrio é função neurológica importante para a manutenção de posturas adequadas, imprescindíveis no ato de aprender, indicativo de maturidade neurológica. OBJETIVO: Estudar a função vestibular em crianças com dificuldades escolares. ESTUDO DE CASO: Estudo clínico com coorte transversal. MATERIAL E MÉTODO: Foram estudadas 88 crianças entre 7 e 12 anos, que freqüentavam escolas públicas da cidade de Piracicaba durante os anos de 2004 e 2006. Os procedimentos utilizados foram: a anamnese; exame otorrinolaringológico; exame audiológico e avaliação vestibular. RESULTADOS: Das crianças avaliadas, 51,0% não relataram dificuldades escolares e 49,0% referiram ter dificuldades escolares. Encontramos 73,3% de exame vestibular normal nas crianças sem dificuldades escolares e 32,6% de normalidade nas crianças com dificuldades escolares. Encontramos alterações vestibulares de origem periférica irritativa tanto unilateral como bilateral, perfazendo um total de 67,4% para as crianças com dificuldades escolares e um total de 26,7% para crianças sem dificuldades escolares. CONCLUSÃO: Todas as alterações vestibulares encontradas foram de origem periférica irritativa. Os dados revelaram uma relação estatisticamente significante nas crianças com dificuldades escolares.Learning is a complex, dynamic process, structured from motor and perception skills which, when cortically processed, give birth to cognition. Balance is a fundamental neurological function that helps us maintain proper postures, an essential factor in learning and a sign or neurologic maturity. AIM: this paper aims to study vestibular function in children underperforming at school. STUDY DESIGN: this is a cross-sectional study. MATERIALS AND METHOD: eighty-eight children with ages ranging between 7 and 12

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

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    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.

  9. Mouse Models for Pendrin-Associated Loss of Cochlear and Vestibular Function

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    Philine Wangemann

    2013-12-01

    Full Text Available The human gene SLC26A4 and the mouse ortholog Slc26a4 code for the protein pendrin, which is an anion exchanger expressed in apical membranes of selected epithelia. In the inner ear, pendrin is expressed in the cochlea, the vestibular labyrinth and the endolymphatic sac. Loss-of-function and hypo-functional mutations cause an enlargement of the vestibular aqueduct (EVA and sensorineural hearing loss. The relatively high prevalence of SLC26A4 mutations provides a strong imperative to develop rational interventions that delay, ameliorate or prevent pendrin-associated loss of cochlear and vestibular function. This review summarizes recent studies in mouse models that have been developed to delineate the role of pendrin in the physiology of hearing and balance and that have brought forward the concept that a temporally and spatially limited therapy may be sufficient to secure a life-time of normal hearing in children bearing mutations of SLC26A4.

  10. [Vestibular function, falls and hip fracture in elderly--a relationship study].

    Science.gov (United States)

    Zur, Oz; Carmeli, Eli; Himellfarb, Mordechi; Berner, Yitshal N

    2004-03-01

    Falling is the main reason for which people over 70 arrive at emergency rooms. Over 90% of hip fractures occur as a direct result of falling. To examine the relationship between the function of the vestibular system and hip fractures following falls in elderly. The research group (n = 84) undergone hip surgery as a result of a fall and were then hospitalized in a rehabilitative geriatric care unit at the Meir Hospital in Kfar Sava. The control group (n = 85)--without any history of a hip fracture and living in a retirement home. Four clinical tests were given to each examinee in order to locate any impairment of the vestibular system. Three of the clinical examinations concentrated on testing the VOR while the fourth test was especially used to locate BPPV (Benign Paroxysmal Positional Vertigo). Sociodemographic status and medical history were taken. A significant difference was found between the two groups (those with a hip fracture and those without any hip fracture) with regard to the functioning of the VOR, age, endocrine disease and medications for treating diabetic. However, there was no significant difference found in the appearance of the BPPV. It is important to locate the elderly who are at risk of falling in nursing homes and the community at large by performing the four simple clinical tests. Correct diagnosis and early treatment of the vestibular impairment in elderly patient can prevent the next fall.

  11. Turning semicircular canal function on its head: dinosaurs and a novel vestibular analysis.

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    Georgi, Justin A; Sipla, Justin S; Forster, Catherine A

    2013-01-01

    Previous investigations have correlated vestibular function to locomotion in vertebrates by scaling semicircular duct radius of curvature to body mass. However, this method fails to discriminate bipedal from quadrupedal non-avian dinosaurs. Because they exhibit a broad range of relative head sizes, we use dinosaurs to test the hypothesis that semicircular ducts scale more closely with head size. Comparing the area enclosed by each semicircular canal to estimated body mass and to two different measures of head size, skull length and estimated head mass, reveals significant patterns that corroborate a connection between physical parameters of the head and semicircular canal morphology. Head mass more strongly correlates with anterior semicircular canal size than does body mass and statistically separates bipedal from quadrupedal taxa, with bipeds exhibiting relatively larger canals. This morphologic dichotomy likely reflects adaptations of the vestibular system to stability demands associated with terrestrial locomotion on two, versus four, feet. This new method has implications for reinterpreting previous studies and informing future studies on the connection between locomotion type and vestibular function.

  12. Turning semicircular canal function on its head: dinosaurs and a novel vestibular analysis.

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    Justin A Georgi

    Full Text Available Previous investigations have correlated vestibular function to locomotion in vertebrates by scaling semicircular duct radius of curvature to body mass. However, this method fails to discriminate bipedal from quadrupedal non-avian dinosaurs. Because they exhibit a broad range of relative head sizes, we use dinosaurs to test the hypothesis that semicircular ducts scale more closely with head size. Comparing the area enclosed by each semicircular canal to estimated body mass and to two different measures of head size, skull length and estimated head mass, reveals significant patterns that corroborate a connection between physical parameters of the head and semicircular canal morphology. Head mass more strongly correlates with anterior semicircular canal size than does body mass and statistically separates bipedal from quadrupedal taxa, with bipeds exhibiting relatively larger canals. This morphologic dichotomy likely reflects adaptations of the vestibular system to stability demands associated with terrestrial locomotion on two, versus four, feet. This new method has implications for reinterpreting previous studies and informing future studies on the connection between locomotion type and vestibular function.

  13. Vestibular Function After Cochlear Implantation: A Comparison of Three Types of Electrodes.

    Science.gov (United States)

    Frodlund, Jonas; Harder, Henrik; Mäki-Torkko, Elina; Ledin, Torbjörn

    2016-12-01

    To investigate the vestibular function after cochlear implantation with different types of electrode arrays. Retrospective cohort study. Academic tertiary referral center. Forty three adults underwent first cochlear implantation. Three consecutive series of patients: Group 1 (n = 13) implanted with a precurved electrode, Group 2 (n = 15) implanted with a straight electrode, Group 3 (n = 15) implanted with a flexible electrode. Patient's vestibular functions were assessed with pre- and postoperative caloric testing using videonystagmography (VNG). The postoperative reduction of the maximum slow phase velocity (MSPV) in the implanted ear was evaluated. Medical charts were reviewed to evaluate the occurrence of late onset of postoperative vestibular symptoms. Mean reduction of MSPV was 7.6/s (standard deviation [SD] 8.0) in Group 1, 23.1/s (SD 16.6) in Group 2, and 0.1/s (SD 18.5) in Group 3. Significant difference was found between Group 1 and 2 (p < 0.030) and between Group 2 and 3 (p < 0.001). Group 2 showed a higher prevalence of late onset of clinical vertigo (28.6%) than Group 1 (7.7%) and 3 (6.7%). In this prospective study, significantly larger reductions of caloric responses were found in subjects implanted with a straight electrode compared with subjects implanted with a precurved or flexible electrode. These findings seem to correlate to a higher prevalence of postoperative vertigo.

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

    Science.gov (United States)

    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

  15. Progress toward development of a multichannel vestibular prosthesis for treatment of bilateral vestibular deficiency.

    Science.gov (United States)

    Fridman, Gene Y; Della Santina, Charles C

    2012-11-01

    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

  16. Electrical vestibular stimulation after vestibular deafferentation and in vestibular schwannoma.

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    Swee Tin Aw

    Full Text Available BACKGROUND: Vestibular reflexes, evoked by human electrical (galvanic vestibular stimulation (EVS, are utilized to assess vestibular function and investigate its pathways. Our study aimed to investigate the electrically-evoked vestibulo-ocular reflex (eVOR output after bilateral and unilateral vestibular deafferentations to determine the characteristics for interpreting unilateral lesions such as vestibular schwannomas. METHODS: EVOR was recorded with dual-search coils as binocular three-dimensional eye movements evoked by bipolar 100 ms-step at EVS intensities of [0.9, 2.5, 5.0, 7.5, 10.0] mA and unipolar 100 ms-step at 5 mA EVS intensity. Five bilateral vestibular deafferented (BVD, 12 unilateral vestibular deafferented (UVD, four unilateral vestibular schwannoma (UVS patients and 17 healthy subjects were tested with bipolar EVS, and five UVDs with unipolar EVS. RESULTS: After BVD, bipolar EVS elicited no eVOR. After UVD, bipolar EVS of one functioning ear elicited bidirectional, excitatory eVOR to cathodal EVS with 9 ms latency and inhibitory eVOR to anodal EVS, opposite in direction, at half the amplitude with 12 ms latency, exhibiting an excitatory-inhibitory asymmetry. The eVOR patterns from UVS were consistent with responses from UVD confirming the vestibular loss on the lesion side. Unexpectedly, unipolar EVS of the UVD ear, instead of absent response, evoked one-third the bipolar eVOR while unipolar EVS of the functioning ear evoked half the bipolar response. CONCLUSIONS: The bidirectional eVOR evoked by bipolar EVS from UVD with an excitatory-inhibitory asymmetry and the 3 ms latency difference between normal and lesion side may be useful for detecting vestibular lesions such as UVS. We suggest that current spread could account for the small eVOR to 5 mA unipolar EVS of the UVD ear.

  17. Cervical and ocular vestibular evoked potentials in Machado-Joseph disease: Functional involvement of otolith pathways.

    Science.gov (United States)

    Ribeiro, Rodrigo Souza; Pereira, Melissa Marques; Pedroso, José Luiz; Braga-Neto, Pedro; Barsottini, Orlando Graziani Povoas; Manzano, Gilberto Mastrocola

    2015-11-15

    Machado-Joseph disease is defined as an autosomal dominant ataxic disorder caused by degeneration of the cerebellum and its connections and is associated with a broad range of clinical symptoms. The involvement of the vestibular system is responsible for several symptoms and signs observed in the individuals affected by the disease. We measured cervical and ocular vestibular evoked myogenic potentials in a sample of Machado-Joseph disease patients in order to assess functional pathways involved. Bilateral measures of cervical and ocular vestibular evoked myogenic potentials (cVEMP and oVEMP) were obtained from 14 symptomatic patients with genetically proven Machado-Joseph disease and compared with those from a control group of 20 healthy subjects. Thirteen (93%) patients showed at least one abnormal test result; oVEMP and cVEMP responses were absent in 17/28 (61%) and 11/28 (39%) measures, respectively; and prolonged latency of cVEMP was found in 3/28 (11%) measures. Of the 13 patients with abnormal responses, 9/13 (69%) patients showed discordant abnormal responses: four with absent oVEMP and present cVEMP, two with absent cVEMP and present oVEMP, and three showed unilateral prolonged cVEMP latencies. Both otolith-related vestibulocollic and vestibulo-ocular pathways are severely affected in Machado-Joseph disease patients evaluated by VEMPs. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Evaluation of the function of the vestibular system in patients with migraine.

    Science.gov (United States)

    Rzeski, Maciej; Stepień, Adam; Kaczorowski, Zbigniew

    2008-01-01

    Migraine is a common disorder with 1-year prevalence of 17.2% in women and 6% in men. Otoneurological symptoms such as phonophobia, tinnitus, vertigo, and dizziness are quite common in migraine. It is estimated that vertigo and dizziness are associated with migraine in 10% of all dizzy patients. The aim of the study was to evaluate the function of the vestibular system using electronystagmography (ENG) and videonystagmography (VNG) in patients with migraine compared to healthy controls. Sixty-two patients (46 women and 16 men) aged 20-35 years (mean age: 28.4 years) with migraine were qualified to the study. All other illnesses that can cause dysfunction of the vestibular system were excluded. The control group consisted of 31 healthy volunteers fulfilling the same demographic criteria as the migraine group (mean age: 29.2 years). Vertigo or dizziness was reported by 41 patients with migraine (66.1%). In ENG/VNG examination changes suggesting impairment of the peripheral or central part of the vestibular system were found in 34 patients (54.8%). In the control group, any abnormalities in ENG/VNG examination were present in 22.6% of individuals (p=0.0031). No statistical significance was found in the frequency of any ENG/VNG abnormalities in subgroups of patients with migraine with aura and migraine without aura. Factors predisposing to dysfunction of the vestibular system in our group of migraineurs were the frequency and duration of the migraine. Vertigo and dizziness are frequent co-existing symptoms in patients with migraine. ENG/VNG abnormali-ties are significantly more frequent in migraineurs than in healthy controls.

  19. Vestibular evaluation in children with otitis media with effusion.

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    Kolkaila, E A; Emara, A A; Gabr, T A

    2015-04-01

    Fifty per cent of children with serous otitis media may have some balance disturbances. To evaluate vestibular function in children with otitis media with effusion. The control group comprised 25 children with bilateral normal hearing and middle-ear function. The study group consisted of 30 children with bilateral otitis media with effusion; these were divided into 2 subgroups according to air-bone gap size. Measures included the Arabic Dizziness Handicap Inventory, an imbalance evaluation sheet for children, vestibular bedside tests for children, and air- and bone-conducted vestibular-evoked myogenic potential testing. Arabic Dizziness Handicap Inventory scores and some vestibular bedside test results were significantly abnormal, with normal video-nystagmography results, in children with otitis media with effusion. Air-conducted vestibular-evoked myogenic potentials were recorded in 73 per cent of children with otitis media with effusion, with significantly delayed latencies. Bone-conducted vestibular-evoked myogenic potentials were successfully detected in 100 per cent of children with otitis media with effusion with similar results to the control group. The Arabic Dizziness Handicap Inventory and vestibular bedside tests are valuable tools for detecting vestibular impairment in children. Bone-conducted vestibular-evoked myogenic potentials are useful for vestibular system evaluation.

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

    Science.gov (United States)

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

    2009-08-01

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

  1. Balance Screening of Vestibular Function in Subjects Aged 4 Years and Older: A Living Laboratory Experience

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    María Carolina Bermúdez Rey

    2017-11-01

    Full Text Available To better understand the various individual factors that contribute to balance and the relation to fall risk, we performed the modified Romberg Test of Standing Balance on Firm and Compliant Support, with 1,174 participants between 4 and 83 years of age. This research was conducted in the Living Laboratory® at the Museum of Science, Boston. We specifically focus on balance test condition 4, in which individuals stand on memory foam with eyes closed, and must rely on their vestibular system; therefore, performance in this balance test condition provides a proxy for vestibular function. We looked for balance variations associated with sex, race/ethnicity, health factors, and age. We found that balance test performance was stable between 10 and 39 years of age, with a slight increase in the failure rate for participants 4–9 years of age, suggesting a period of balance development in younger children. For participants 40 years and older, the balance test failure rate increased progressively with age. Diabetes and obesity are the two main health factors we found associated with poor balance, with test condition 4 failure rates of 57 and 19%, respectively. An increase in the odds of having fallen in the last year was associated with a decrease in the time to failure; once individuals dropped below a time to failure of 10 s, there was a significant 5.5-fold increase in the odds of having fallen in the last 12 months. These data alert us to screen for poor vestibular function in individuals 40 years and older or suffering from diabetes, in order to undertake the necessary diagnostic and rehabilitation measures, with a focus on reducing the morbidity and mortality of falls.

  2. Vestibular function in patients with Niemann-Pick type C disease.

    Science.gov (United States)

    Bremova, Tatiana; Krafczyk, Siegbert; Bardins, Stanislavs; Reinke, Jörg; Strupp, Michael

    2016-11-01

    We investigated whether vestibular dysfunction may cause or contribute to postural imbalance and falls in patients with Niemann-Pick type C disease (NP-C). Eight patients with NP-C disease and 20 healthy controls were examined using the video-based head impulse test (vHIT) and caloric irrigation to investigate horizontal canal function as well as ocular- and cervical vestibular evoked myogenic potentials (o- and cVEMP), and binocular subjective visual vertical estimation (SVV) for otolith function, and static posturography. There were no significant differences in vestibulo-ocular gain, caloric excitability, o-/cVEMP measures or SVV between the two groups. Posturographic total sway path (tSP) and root mean square (RMS) were significantly higher in NP-C than in controls in 3 out of 4 conditions. The Romberg quotient (RQ) to assess the amount of visual stabilization was significantly lower in the NP-C than in the HC group. In contrast to other inherited metabolic disorders, such as Morbus Gaucher type 3, we did not find any evidence for an impairment of canal or otolith function in patients with NP-C as their cause of postural imbalance. Since RQ was low in NP-C patients, indicating proper sensory input, the observed increased postural sway is most likely due to a cerebellar dysfunction in NP-C, which may therefore, explain postural imbalance.

  3. Função vestibular no acidente vascular cerebral do território carot��deo Vestibular function in carotid territory stroke patients

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    Anna Paula Batista de Ávila Pires

    2013-02-01

    Full Text Available Pacientes após Acidente Vascular Cerebral (AVC podem apresentar sintomas otoneurológicos. OBJETIVO: Avaliar a função vestibular de pacientes com antecedente pessoal de AVC no território carotídeo. Desenho científico: estudo de coorte histórica com corte transversal. MÉTODO: Quarenta pacientes foram submetidos à anamnese, exame otorrinolaringológico, Dizziness Handicap Inventory e vectoeletronistagmografia. RESULTADOS: Anormalidades discretas dos movimentos sacádicos foram encontradas em 20 pacientes (50,0%; nove referiram desequilíbrio e um tontura. O ganho do rastreio pendular foi anormal em 17 casos (42,5%; seis referiram desequilíbrio e um tontura. Preponderância direcional anormal do nistagmoperrotatório ocorreu em dois casos (5,0%, que referiram desequilíbrio. A prova calórica identificou três casos (7,5% com predomínio labiríntico anormal e dois (5,0% com preponderância direcional anormal do nistagmo; os cinco casos relataram desequilíbrio. Dos 11 pacientes que não referiram manifestações de alteração do equilíbrio corporal, 10 apresentaram alterações nos movimentos sacádicos e no rastreio pendular e um apresentou exame vestibular normal. CONCLUSÃO: Pacientes com antecedente pessoal de AVC no território carotídeo podem apresentar tontura ou desequilíbrio corporal e sinais de comprometimento da motilidade ocular e da função vestibular.Stroke patients may present otoneurological symptoms. OBJECTIVE: To assess the vestibular function of subjects with a history of carotid territory stroke. METHOD: This historical cohort cross sectional study enrolled 40 patients; subjects answered the Dizziness Handicap Inventory, were interviewed and submitted to ENT examination and vectorelectronystagmography. RESULTS: Mild saccadic movement anomalies were seen in 20 patients (50.0%; nine complained of imbalance and dizziness. Abnormal smooth pursuit gain was seen in 17 cases (42.5%; six subjects reported imbalance and

  4. Studies of the Interactions Between Vestibular Function and Tactual Orientation Display Systems

    Science.gov (United States)

    Cholewiak, Roger W.; Reschke, Millard F.

    1997-01-01

    When humans experience conditions in which internal vestibular cues to movement or spatial location are challenged or contradicted by external visual information, the result can be spatial disorientation, often leading to motion sickness. Spatial disorientation can occur in any situation in which the individual is passively moved in the environment, but is most common in automotive, aircraft, or undersea travel. Significantly, the incidence of motion sickness in space travel is great: The majority of individuals in Shuttle operations suffer from the syndrome. Even after the space-sickness-producing influences of spatial disorientation dissipate, usually within several days, there are other situations in which, because of the absence of reliable or familiar vestibular cues, individuals in space still experience disorientation, resulting in a reliance on the already preoccupied sense of vision. One possible technique to minimize the deleterious effects of spatial disorientation might be to present attitude information (including orientation, direction, and motion) through another less-used sensory modality - the sense of touch. Data from experiences with deaf and blind persons indicate that this channel can provide useful communication and mobility information on a real-time basis. More recently, technologies have developed to present effective attitude information to pilots in situations in which dangerously ambiguous and conflicting visual and vestibular sensations occur. This summers project at NASA-Johnson Space Center will evaluate the influence of motion-based spatial disorientation on the perception of tactual stimuli representing veridical position and orientation information, presented by new dynamic vibrotactile array display technologies. In addition, the possibility will be explored that tactile presentations of motion and direction from this alternative modality might be useful in mitigating or alleviating spatial disorientation produced by multi

  5. Newly Diagnosed Meniere's Disease: Clinical Course With Initiation of Noninvasive Treatment Including an Accounting of Vestibular Migraine.

    Science.gov (United States)

    Sbeih, Firas; Christov, Florian; Gluth, Michael B

    2018-05-01

    To describe the course of Meniere's disease with noninvasive treatment during the first few years after initial diagnosis. A retrospective review of consecutive patients with newly diagnosed definite Meniere's disease between 2013 and 2016 and a minimum follow-up of 1 year. Patients received a written plan for low sodium, water therapy, and treatment with a diuretic and/or betahistine. Subjects were screened and treated for vestibular migraine as needed. Vertigo control and hearing status at most recent follow-up were assessed. Forty-four subjects had an average follow up of 24.3 months. Thirty-four percent had Meniere's disease and vestibular migraine, and 84% had unilateral Meniere's disease. Seventy-five percent had vertigo well controlled at most recent follow-up, with only noninvasive treatments. Age, gender, body mass index, presence of vestibular migraine, bilateral disease, and duration of follow-up did not predict noninvasive treatment failure. Worse hearing threshold at 250 Hz and lower pure tone average (PTA) at the time of diagnosis did predict failure. Fifty-two percent of ears had improved PTA at most recent visit, 20% had no change, and 28% were worse Conclusions: Encountering excellent vertigo control and stable hearing after a new diagnosis of Meniere's disease is possible with noninvasive treatments. Worse hearing status at diagnosis predicted treatment failure.

  6. The combination of vestibular impairment and congenital sensorineural hearing loss predisposes patients to ocular anomalies, including Usher syndrome.

    Science.gov (United States)

    Kletke, S; Batmanabane, V; Dai, T; Vincent, A; Li, S; Gordon, K A; Papsin, B C; Cushing, S L; Héon, E

    2017-07-01

    The co-occurrence of hearing impairment and visual dysfunction is devastating. Most deaf-blind etiologies are genetically determined, the commonest being Usher syndrome (USH). While studies of the congenitally deaf population reveal a variable degree of visual problems, there are no effective ophthalmic screening guidelines. We hypothesized that children with congenital sensorineural hearing loss (SNHL) and vestibular impairment were at an increased risk of having USH. A retrospective chart review of 33 cochlear implants recipients for severe to profound SNHL and measured vestibular dysfunction was performed to determine the ocular phenotype. All the cases had undergone ocular examination and electroretinogram (ERG). Patients with an abnormal ERG underwent genetic testing for USH. We found an underlying ocular abnormality in 81.81% (27/33) of cases; of which 75% had refractive errors, and 50% of those patients showed visual improvement with refractive correction. A total of 14 cases (42.42%; 14/33) had generalized rod-cone dysfunction on ERG suggestive of Usher syndrome type 1, confirmed by mutational analysis. This work shows that adding vestibular impairment as a criterion for requesting an eye exam and adding the ERG to detect USH increases the chances of detecting ocular anomalies, when compared with previous literature focusing only on congenital SNHL. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Aging of the Human Vestibular System

    Science.gov (United States)

    Zalewski, Christopher K.

    2015-01-01

    Aging affects every sensory system in the body, including the vestibular system. Although its impact is often difficult to quantify, the deleterious impact of aging on the vestibular system is serious both medically and economically. The deterioration of the vestibular sensory end organs has been known since the 1970s; however, the measurable impact from these anatomical changes remains elusive. Tests of vestibular function either fall short in their ability to quantify such anatomical deterioration, or they are insensitive to the associated physiologic decline and/or central compensatory mechanisms that accompany the vestibular aging process. When compared with healthy younger individuals, a paucity of subtle differences in test results has been reported in the healthy older population, and those differences are often observed only in response to nontraditional and/or more robust stimuli. In addition, the reported differences are often clinically insignificant insomuch that the recorded physiologic responses from the elderly often fall within the wide normative response ranges identified for normal healthy adults. The damaging economic impact of such vestibular sensory decline manifests itself in an exponential increase in geriatric dizziness and a subsequent higher prevalence of injurious falls. An estimated $10 to $20 billion dollar annual cost has been reported to be associated with falls-related injuries and is the sixth leading cause of death in the elderly population, with a 20% mortality rate. With an estimated 115% increase in the geriatric population over 65 years of age by the year 2050, the number of balanced-disordered patients with a declining vestibular system is certain to reach near epidemic proportions. An understanding of the effects of age on the vestibular system is imperative if clinicians are to better manage elderly patients with balance disorders, dizziness, and vestibular disease. PMID:27516717

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

    Science.gov (United States)

    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.

  9. Metabolic disorders of the vestibular system.

    Science.gov (United States)

    Rybak, L P

    1995-01-01

    This article reviews the impact of metabolic disorders on vestibular function. Diabetes mellitus is a disorder of glucose metabolism that can be associated with vestibular dysfunction. Vertigo can be alleviated by diet management in many cases. Elevated levels of blood lipids have been implicated in cochleovestibular disorders. Treatment with a lipid-lowering drug has resulted in improved auditory and vestibular function in a placebo-controlled trial. Hypothyroidism may affect different parts of the vestibular system depending on the severity and duration of thyroid deficiency. Severe congenital hypothyroidism can cause central vestibular disorders affecting the cerebellum, whereas mild hypothyroidism may result in peripheral vestibulopathy. Endogenous alterations in concentrations of estrogen and progesterone in the premenstrual syndrome or with the use of exogenous hormones such as oral contraceptives may trigger vertigo. Metabolic evaluations for unexplained vertigo should include a lipoprotein profile, with cholesterol and triglyceride levels, glucose tolerance test, and thyroid hormone measurements. Nutritional and drug therapy may be useful to reverse the vestibular dysfunction.

  10. Dynamic changes in the inner ear function and vestibular neural pathway related to the progression of labyrinthine infarction in patient with an anterior inferior cerebellar artery infarction.

    Science.gov (United States)

    Kim, Duk Rim; Lee, Hyo-Jeong; Kim, Hyung-Jong; Hong, Sung Kwang

    2011-12-01

    To describe changes in the inner ear function and the vestibular neural pathway according to the progression of a labyrinthine infarction in a patient with an anterior inferior cerebellar artery (AICA) infarction. A 58-year-old woman with hypertension who presented with isolated inner ear symptoms similar to those of endolymphatic hydrops but finally progressed to an AICA infarction. Serial neurotologic testing according to progression to an AICA infarction and antiplatelet therapy. Radiologic findings and neurotologic parameters, including pure tone audiogram thresholds, spontaneous nystagmus, summating potentials/action potentials on electrocochleography, interaural amplitude difference on the vestibular-evoked myogenic potential test, canal paresis and fixation index on the bithermal caloric test, and gain on oculomotor tests. Our patient initially presented with sudden hearing loss and was diagnosed with an acute AICA infarction on a follow up MRI. Dynamic change in neurotologic testing was observed during disease progression. The vertigo and motion intolerance improved gradually after antiplatelet therapy. Changes in the clinical profile, which were documented during a transition from isolated labyrinthine ischemia to an AICA infarction, suggest that sensitivity to an ischemic injury is variable in different components of the labyrinthine organs in addition to providing a new insight into the response of vestibular neural pathway to ischemic injury.

  11. Vestibular perception following acute unilateral vestibular lesions.

    Directory of Open Access Journals (Sweden)

    Sian Cousins

    Full Text Available Little is known about the vestibulo-perceptual (VP system, particularly after a unilateral vestibular lesion. We investigated vestibulo-ocular (VO and VP function in 25 patients with vestibular neuritis (VN acutely (2 days after onset and after compensation (recovery phase, 10 weeks. Since the effect of VN on reflex and perceptual function may differ at threshold and supra-threshold acceleration levels, we used two stimulus intensities, acceleration steps of 0.5°/s(2 and velocity steps of 90°/s (acceleration 180°/s(2. We hypothesised that the vestibular lesion or the compensatory processes could dissociate VO and VP function, particularly if the acute vertiginous sensation interferes with the perceptual tasks. Both in acute and recovery phases, VO and VP thresholds increased, particularly during ipsilesional rotations. In signal detection theory this indicates that signals from the healthy and affected side are still fused, but result in asymmetric thresholds due to a lesion-induced bias. The normal pattern whereby VP thresholds are higher than VO thresholds was preserved, indicating that any 'perceptual noise' added by the vertigo does not disrupt the cognitive decision-making processes inherent to the perceptual task. Overall, the parallel findings in VO and VP thresholds imply little or no additional cortical processing and suggest that vestibular thresholds essentially reflect the sensitivity of the fused peripheral receptors. In contrast, a significant VO-VP dissociation for supra-threshold stimuli was found. Acutely, time constants and duration of the VO and VP responses were reduced - asymmetrically for VO, as expected, but surprisingly symmetrical for perception. At recovery, VP responses normalised but VO responses remained shortened and asymmetric. Thus, unlike threshold data, supra-threshold responses show considerable VO-VP dissociation indicative of additional, higher-order processing of vestibular signals. We provide evidence of

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

    Science.gov (United States)

    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.

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

    OpenAIRE

    D'Silva, Linda J.; Lin, James; Staecker, Hinrich; Whitney, Susan L.; Kluding, Patricia M.

    2015-01-01

    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. Pa...

  14. Vestibular and balance issues following sport-related concussion.

    Science.gov (United States)

    Valovich McLeod, Tamara C; Hale, Troy D

    2015-01-01

    To review relevant literature regarding the effect of concussion on vestibular function, impairments, assessments and management strategies. REASONING: Dizziness and balance impairments are common following sport-related concussion. Recommendations regarding the management of sport-related concussion suggest including tests of balance within the multifactorial assessment paradigm for concussive injuries. The literature was searched for guidelines and original studies related to vestibular impairments following concussion, oculomotor and balance assessments and treatment or rehabilitation of vestibular impairments. The databases searched included Medline, CINAHL, Sport Discus and the Cochrane Database of Systematic Reviews through October 2013. Dizziness following concussion occurs in ∼67-77% of cases and has been implicated as a risk factor for a prolonged recovery. Balance impairments also occur after concussion and last 3-10 days post-injury. Assessments of balance can be done using both clinical and instrumented measures with success. Vestibular rehabilitation has been shown to improve outcomes in patients with vestibular impairments, with one study demonstrating success in decreasing symptoms and increasing function following concussion. Best practices suggest that the assessment of vestibular function through cranial nerve, oculomotor and balance assessments are an important aspect of concussion management. Future studies should evaluate the effectiveness of vestibular rehabilitation for improving patient outcomes.

  15. Recovery from Spatial Neglect with Intra- and Transhemispheric Functional Connectivity Changes in Vestibular and Visual Cortex Areas—A Case Study

    Directory of Open Access Journals (Sweden)

    Julian Conrad

    2018-03-01

    Full Text Available ObjectiveVestibular 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.MethodsResting-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.ResultsDuring 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.ConclusionImprovement 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.

  16. Vestibular Dysfunction in Patients with Enlarged Vestibular Aqueduct.

    Science.gov (United States)

    Zalewski, Chris K; Chien, Wade W; King, Kelly A; Muskett, Julie A; Baron, Rachel E; Butman, John A; Griffith, Andrew J; Brewer, Carmen C

    2015-08-01

    Enlarged vestibular aqueduct (EVA) is the most common inner ear malformation. While a strong correlative relationship between EVA and hearing loss is well established, its association with vestibular dysfunction is less well understood. In this study, we examine the effects of EVA on the vestibular system in patients with EVA. Prospective, cross-sectional study of a cohort ascertained between 1999 and 2013. National Institutes of Health Clinical Center, a federal biomedical research facility. In total, 106 patients with unilateral or bilateral EVA, defined as a midpoint diameter greater than 1.5 mm, were referred or self-referred to participate in a study of the clinical and molecular aspects of EVA. Clinical history was ascertained with respect to the presence or absence of various vestibular signs and symptoms and history of head trauma. Videonystagmography (VNG), cervical vestibular evoked myogenic potential (cVEMP), and rotational vestibular testing (RVT) were performed to assess the vestibular function. Of the patients with EVA, 45% had vestibular signs and symptoms, and 44% of tested patients had abnormal VNG test results. An increased number of vestibular signs and symptoms was correlated with the presence of bilateral EVA (P = .008) and a history of head injury (P VNG results also correlated with a history of head injury (P = .018). Vestibular dysfunction is common in patients with EVA. However, not all patients with vestibular signs and symptoms have abnormal vestibular test results. Clinicians should be aware of the high prevalence of vestibular dysfunction in patients with EVA. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

  17. Common Vestibular Disorders

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    Dimitrios G. Balatsouras

    2017-01-01

    Full Text Available The three most common vestibular diseases, benign paroxysmal positional vertigo (BPPV, Meniere's disease (MD and vestibular neuritis (VN, are presented in this paper. BPPV, which is the most common peripheral vestibular disorder, can be defined as transient vertigo induced by a rapid head position change, associated with a characteristic paroxysmal positional nystagmus. Canalolithiasis of the posterior semicircular canal is considered the most convincing theory of its pathogenesis and the development of appropriate therapeutic maneuvers resulted in its effective treatment. However, involvement of the horizontal or the anterior canal has been found in a significant rate and the recognition and treatment of these variants completed the clinical picture of the disease. MD is a chronic condition characterized by episodic attacks of vertigo, fluctuating hearing loss, tinnitus, aural pressure and a progressive loss of audiovestibular functions. Presence of endolymphatic hydrops on postmortem examination is its pathologic correlate. MD continues to be a diagnostic and therapeutic challenge. Patients with the disease range from minimally symptomatic, highly functional individuals to severely affected, disabled patients. Current management strategies are designed to control the acute and recurrent vestibulopathy but offer minimal remedy for the progressive cochlear dysfunction. VN is the most common cause of acute spontaneous vertigo, attributed to acute unilateral loss of vestibular function. Key signs and symptoms are an acute onset of spinning vertigo, postural imbalance and nausea as well as a horizontal rotatory nystagmus beating towards the non-affected side, a pathological headimpulse test and no evidence for central vestibular or ocular motor dysfunction. Vestibular neuritis preferentially involves the superior vestibular labyrinth and its afferents. Symptomatic medication is indicated only during the acute phase to relieve the vertigo and nausea

  18. Using Low Levels of Stochastic Vestibular Stimulation to Improve Balance Function.

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    Rahul Goel

    Full Text Available Low-level stochastic vestibular stimulation (SVS has been associated with improved postural responses in the medio-lateral (ML direction, but its effect in improving balance function in both the ML and anterior-posterior (AP directions has not been studied. In this series of studies, the efficacy of applying low amplitude SVS in 0-30 Hz range between the mastoids in the ML direction on improving cross-planar balance function was investigated. Forty-five (45 subjects stood on a compliant surface with their eyes closed and were instructed to maintain a stable upright stance. Measures of stability of the head, trunk, and whole body were quantified in ML, AP and combined APML directions. Results show that binaural bipolar SVS given in the ML direction significantly improved balance performance with the peak of optimal stimulus amplitude predominantly in the range of 100-500 μA for all the three directions, exhibiting stochastic resonance (SR phenomenon. Objective perceptual and body motion thresholds as estimates of internal noise while subjects sat on a chair with their eyes closed and were given 1 Hz bipolar binaural sinusoidal electrical stimuli were also measured. In general, there was no significant difference between estimates of perceptual and body motion thresholds. The average optimal SVS amplitude that improved balance performance (peak SVS amplitude normalized to perceptual threshold was estimated to be 46% in ML, 53% in AP, and 50% in APML directions. A miniature patch-type SVS device may be useful to improve balance function in people with disabilities due to aging, Parkinson's disease or in astronauts returning from long-duration space flight.

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

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    Michael Handler

    2017-12-01

    Full Text Available 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.

  20. A neuroscientific account of how vestibular disorders impair bodily self-consciousness

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    Christophe eLopez

    2013-12-01

    Full Text Available The consequences of vestibular disorders on balance, oculomotor control and self-motion perception have been extensively described in humans and animals. More recently, vestibular disorders have been related to cognitive deficits in spatial navigation and memory tasks. Less frequently, abnormal bodily perceptions have been described in patients with vestibular disorders. Altered forms of bodily self-consciousness include distorted body image and body schema, disembodied self-location (out-of-body experience, altered sense of agency, as well as more complex experiences of dissociation and detachment from the self (depersonalization. In this article, I suggest that vestibular disorders create sensory conflict or mismatch in multisensory brain regions, producing perceptual incoherence and abnormal body and self perceptions. This hypothesis is based on recent functional mapping of the human vestibular cortex, showing vestibular projections to the primary and secondary somatosensory cortex and in several multisensory areas found to be crucial for bodily self-consciousness.

  1. Trigeminal, Visceral and Vestibular Inputs May Improve Cognitive Functions by Acting through the Locus Coeruleus and the Ascending Reticular Activating System: A New Hypothesis

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    Vincenzo De Cicco

    2018-01-01

    Full Text Available It is known that sensory signals sustain the background discharge of the ascending reticular activating system (ARAS which includes the noradrenergic locus coeruleus (LC neurons and controls the level of attention and alertness. Moreover, LC neurons influence brain metabolic activity, gene expression and brain inflammatory processes. As a consequence of the sensory control of ARAS/LC, stimulation of a sensory channel may potential influence neuronal activity and trophic state all over the brain, supporting cognitive functions and exerting a neuroprotective action. On the other hand, an imbalance of the same input on the two sides may lead to an asymmetric hemispheric excitability, leading to an impairment in cognitive functions. Among the inputs that may drive LC neurons and ARAS, those arising from the trigeminal region, from visceral organs and, possibly, from the vestibular system seem to be particularly relevant in regulating their activity. The trigeminal, visceral and vestibular control of ARAS/LC activity may explain why these input signals: (1 affect sensorimotor and cognitive functions which are not directly related to their specific informational content; and (2 are effective in relieving the symptoms of some brain pathologies, thus prompting peripheral activation of these input systems as a complementary approach for the treatment of cognitive impairments and neurodegenerative disorders.

  2. Assessment of otolith function using cervical and ocular vestibular evoked myogenic potentials in individuals with motion sickness.

    Science.gov (United States)

    Singh, Niraj Kumar; Pandey, Preeti; Mahesh, Soumya

    2014-01-01

    The involvement of otolith organs in motion sickness has long been debated; however, equivocal findings exist in literature. The present study thus aimed at evaluating the otolith functioning in individuals with motion sickness. Cervical and ocular vestibular evoked myogenic potentials were recorded from 30 individuals with motion sickness, 30 professional drivers and 30 healthy individuals. The results revealed no significant difference in latencies and amplitudes between the groups (p>0.05). Nonetheless, thresholds were significantly elevated and inter-aural asymmetry ratio significantly higher in motion sickness susceptible group (p otolithic function seem the likely reasons behind motion sickness susceptibility.

  3. Vestibular function in a group of adults with HIV/AIDS on HAART ...

    African Journals Online (AJOL)

    Materials and Methods: The main aim of the current study was to investigate and monitor the vestibular status in a group of adult patients with AIDS receiving Highly Active Antiretroviral Therapy (HAART) and other therapies in a hospital outpatient clinic in Gauteng, South Africa. The study was exploratory and observational ...

  4. Complications of Microsurgery of Vestibular Schwannoma

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    Jan Betka

    2014-01-01

    Full Text Available Background. The aim of this study was to analyze complications of vestibular schwannoma (VS microsurgery. Material and Methods. A retrospective study was performed in 333 patients with unilateral vestibular schwannoma indicated for surgical treatment between January 1997 and December 2012. Postoperative complications were assessed immediately after VS surgery as well as during outpatient followup. Results. In all 333 patients microsurgical vestibular schwannoma (Koos grade 1: 12, grade 2: 34, grade 3: 62, and grade 4: 225 removal was performed. The main neurological complication was facial nerve dysfunction. The intermediate and poor function (HB III–VI was observed in 124 cases (45% immediately after surgery and in 104 cases (33% on the last followup. We encountered disordered vestibular compensation in 13%, permanent trigeminal nerve dysfunction in 1%, and transient lower cranial nerves (IX–XI deficit in 6%. Nonneurological complications included CSF leakage in 63% (lateral/medial variant: 99/1%, headache in 9%, and intracerebral hemorrhage in 5%. We did not encounter any case of meningitis. Conclusions. Our study demonstrates that despite the benefits of advanced high-tech equipment, refined microsurgical instruments, and highly developed neuroimaging technologies, there are still various and significant complications associated with vestibular schwannomas microsurgery.

  5. Clinical evaluation of elderly people with chronic vestibular disorder.

    Science.gov (United States)

    Gazzola, Juliana Maria; Ganança, Fernando Freitas; Aratani, Mayra Cristina; Perracini, Monica Rodrigues; Ganança, Maurício Malavasi

    2006-01-01

    Dizziness is common among the elderly. To characterize social, demographic, clinical, functional and otoneurological data in elderly patients with chronic vestibular disorder. A sequential study of 120 patients with chronic vestibular disorder. Simple descriptive analyses were undertaken. Most of the patients were female (68.3%) with a mean age of 73.40+/-5.77 years. The average number of illnesses associated with the vestibular disorder was 3.83+/-1.84; the patients were taking on average 3.86+/-2.27 different medications. The most prevalent diagnosis on the vestibular exam was unilateral vestibular loss (29.8%) and the most prevalent etiology was metabolic vestibulopathy (40.0%) followed by benign paroxysmal positional vertigo (36.7%). Fifty-two patients (43.3%) had experienced dizziness for 5 years or more. Sixty-four patients (53.3%) had at least one fall in the last year and thirty-five (29.2%) had recurrent falls. Most of the sample included females with associated diseases, and using many different drugs. The most prevalent vestibular diseases were metabolic and vascular labyrinth conditions. Dizziness is a chronic symptom in elderly patients. The association of two vestibular diseases is common. Falls are prevalent in chronic dizzy elderly patients.

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

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    Martin Göttlich

    2014-01-01

    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 changes in the resting brain are robust and task-independent as they were found in the absence of sensory stimulation and without a region-related a priori hypothesis. Therefore they may indicate a fundamental disease-related change in the resting brain. They may account for the patients' persistent deficits in visuo-spatial attention, spatial orientation and unsteadiness. The relation of increasing connectivity in the inferior parietal lobe, specifically SMG, to improvement of VOR during active head movements reflects cortical plasticity in BVF and may play a clinical role in vestibular rehabilitation.

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

    Science.gov (United States)

    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.

  8. A new dynamic visual acuity test to assess peripheral vestibular function.

    Science.gov (United States)

    Vital, Domenic; Hegemann, Stefan C A; Straumann, Dominik; Bergamin, Oliver; Bockisch, Christopher J; Angehrn, Dominik; Schmitt, Kai-Uwe; Probst, Rudolf

    2010-07-01

    To evaluate a novel test for dynamic visual acuity (DVA) that uses an adaptive algorithm for changing the size of Landolt rings presented during active or passive head impulses, and to compare the results with search-coil head impulse testing. Prospective study in healthy individuals and patients with peripheral vestibular deficits. Tertiary academic center. One hundred neuro-otologically healthy individuals (age range, 19-80 years) and 15 patients with bilateral (n = 5) or unilateral (n = 10) peripheral vestibular loss (age range, 27-72 years). Testing of static visual acuity (SVA), DVA during active and passive horizontal head rotations (optotype presentation at head velocities >100 degrees/s and >150 degrees/s), and quantitative horizontal head impulse testing with scleral search coils. Difference between SVA and DVA, that is, visual acuity loss (VA loss), gain of the high-acceleration vestibulo-ocular reflex. Passive head impulses and higher velocities were more effective than active impulses and lower velocities. Using passive head impulses and velocities higher than 150 degrees/s, the DVA test discriminated significantly (P test sensitivity was 100%, specificity was 94%, and accuracy was 95%, with search-coil head impulse testing used as a reference. In healthy individuals, VA loss increased significantly with age (P testing with Landolt rings that are adaptively changed in size enables detection of peripheral vestibular dysfunction in a fast and simple way.

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

    Science.gov (United States)

    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.

  10. The vestibular implant: Quo vadis?

    Directory of Open Access Journals (Sweden)

    Raymond eVan De Berg

    2011-08-01

    Full Text Available AbstractObjective: to assess the progress of the development of the vestibular implant and its feasibility short-term. Data sources: a search was performed in Pubmed, Medline and Embase. Key words used were vestibular prosth* and vestibular implant. The only search limit was language: English or Dutch. Additional sources were medical books, conference lectures and our personal experience with per-operative vestibular stimulation in patients selected for cochlear implantation.Study selection: all studies about the vestibular implant and related topics were included and evaluated by two reviewers. No study was excluded since every study investigated different aspects of the vestibular implant. Data extraction and synthesis: data was extracted by the first author from selected reports, supplemented by additional information, medical books conference lectures. Since each study had its own point of interest with its own outcomes, it was not possible to compare data of different studies. Conclusion: to use a basic vestibular implant in humans seems feasible in the very near future. Investigations show that electric stimulation of the canal nerves induces a nystagmus which corresponds to the plane of the canal which is innervated by the stimulated nerve branch. The brain is able to adapt to a higher baseline stimulation, while still reacting on a dynamic component. The best response will be achieved by a combination of the optimal stimulus (stimulus profile, stimulus location, precompensation, complemented by central vestibular adaptation. The degree of response will probably vary between individuals, depending on pathology and their ability to adapt.

  11. Distal radioulnar joint: functional anatomy, including pathomechanics.

    Science.gov (United States)

    Haugstvedt, J R; Langer, M F; Berger, R A

    2017-05-01

    The distal radioulnar joint allows the human to rotate the forearm to place the hand in a desired position to perform different tasks, without interfering with the grasping function of the hand. The ulna is the stable part of the forearm around which the radius rotates; the stability of the distal radioulnar joint is provided by the interaction between ligaments, muscles and bones. The stabilizing structures are the triangular fibrocartilage complex, the ulnocarpal ligament complex, the extensor carpi ulnaris tendon and tendon sheath, the pronator quadratus, the interosseous membrane and ligament, the bone itself and the joint capsule. The purpose of this review article is to present and illustrate the current understanding of the functional anatomy and pathomechanics of this joint.

  12. Why cold water delays the onset of vestibular vertigo-An functional MRI study

    Energy Technology Data Exchange (ETDEWEB)

    Wang Zhi [Department of Radiology, Beijing Hospital, No. 1 Dahua Road Dongdan, Beijing 100730 (China)], E-mail: zhiwang76@gmail.com; Chen Min [Department of Radiology, Beijing Hospital, No. 1 Dahua Road Dongdan, Beijing 100730 (China); Gong Xia; Huang Weining [Department of E.N.T., Beijing Hospital, No. 1 Dahua Road Dongdan, Beijing 100730 (China); Xu Liang [Department of Radiology, Beijing Hospital, No. 1 Dahua Road Dongdan, Beijing 100730 (China); Zhou Cheng [Department of Radiology, Beijing Hospital, No. 1 Dahua Road Dongdan, Beijing 100730 (China)], E-mail: chengzhou2000@yahoo.com

    2008-09-15

    The mechanism of vertigo is unclear. Generally, the peak time or the latency of blood oxygenation level dependent (BOLD) effect is about 6 s. However, clinically, the latency of vertigo or nystagmus induced by caloric stimulations is much longer than 6 s, commonly about 30 s induced by water of 30 deg. C or 44 deg. C. We hypothesize that there is an inhibitive power or mechanism for the occurrence of vestibular vertigo, since it is an unpleasant feeling. The caloric test was performed in healthy volunteers during the BOLD fMRI scanning. The overlaid results of statistical parametric mapping (SPM) showed that three brain regions showed neural activation during vestibular dizziness while deactivation occurred in response to cold water simulation: (1) supplementary motor area (SMA); (2) middle temporal area/medial superior temporal area (MT/MST); (3) visual association area (BA19). The time course of the regions further demonstrated that the signal decreased during the cold-water stimulation and increased during the period of vertigo. We therefore further hypothesize that there may be two forces for the production of vertigo: inhibitory power (IP) and promotive power (PP). The delayed onset of vertigo was the result of the interaction between IP and PP. All of our findings, for the first time, suggested such an original mechanism of vertigo.

  13. Why cold water delays the onset of vestibular vertigo-An functional MRI study

    International Nuclear Information System (INIS)

    Wang Zhi; Chen Min; Gong Xia; Huang Weining; Xu Liang; Zhou Cheng

    2008-01-01

    The mechanism of vertigo is unclear. Generally, the peak time or the latency of blood oxygenation level dependent (BOLD) effect is about 6 s. However, clinically, the latency of vertigo or nystagmus induced by caloric stimulations is much longer than 6 s, commonly about 30 s induced by water of 30 deg. C or 44 deg. C. We hypothesize that there is an inhibitive power or mechanism for the occurrence of vestibular vertigo, since it is an unpleasant feeling. The caloric test was performed in healthy volunteers during the BOLD fMRI scanning. The overlaid results of statistical parametric mapping (SPM) showed that three brain regions showed neural activation during vestibular dizziness while deactivation occurred in response to cold water simulation: (1) supplementary motor area (SMA); (2) middle temporal area/medial superior temporal area (MT/MST); (3) visual association area (BA19). The time course of the regions further demonstrated that the signal decreased during the cold-water stimulation and increased during the period of vertigo. We therefore further hypothesize that there may be two forces for the production of vertigo: inhibitory power (IP) and promotive power (PP). The delayed onset of vertigo was the result of the interaction between IP and PP. All of our findings, for the first time, suggested such an original mechanism of vertigo

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

    Science.gov (United States)

    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 (pexercise 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.

  15. Effects of deuterium oxide and galvanic vestibular stimulation on visual cortical cell function

    International Nuclear Information System (INIS)

    Reinis, S.; Landolt, J.P.; Weiss, D.S.; Money, K.E.

    1984-01-01

    The spontaneous and evoked unit activities of complex visual cortical cells were recorded from Brodmann's area 18 in immobilized, unanesthetized cats before, during, and after stimulation of the vestibular system. The vestibular system was stimulated by intravenous injection of deuterium oxide (D2O)--a noted nystagmogenic agent--or by direct galvanic stimulation of the labyrinth. Measures of the receptive-field areas, poststimulus time histograms, directional preferences, and the optimal speed of the light bar stimulating the cell were obtained before and after the application of D2O. Directional preferences were determined in a novel manner, using a method derived from a hierarchical clustering technique. Data were collected and analyzed from a) visual cortical cells in cats with intact labyrinths, b) visual cortical cells in cats following bilateral labrinthectomies, and c) nonvisual cortical cells in cats with intact labyrinths. The other cellular characteristics were also altered by the D2O. Galvanic stimulation of the labyrinth resembles, in its effects, the injection of D2O. In labyrinth-intact cats, the time course of area 18 spontaneous activity dramatically increased 30 min or more after D2O was administered. It peaked 2-3 h later and still had not returned to preinjection levels even 7 h after the D2O administration. In bilaterally labyrinthectomized cats, the spontaneous activity of the visual cells did not change following D2O administration. In nonvisual cells from labyrinth-intact cats, the spontaneous activity demonstrated a slight but significant decrease over time after D2O injection. In pilot studies, the cats were injected with D2O. Within 8-10 min afterward, signs of positional nystagmus commenced; and within 30 min, problems in maintaining balance were noted. This continued for 7-8 h before disappearing. In the labyrinthectomized animals, such effects were not observed

  16. Effects of deuterium oxide and galvanic vestibular stimulation on visual cortical cell function

    Energy Technology Data Exchange (ETDEWEB)

    Reinis, S.; Landolt, J.P.; Weiss, D.S.; Money, K.E.

    1984-03-01

    The spontaneous and evoked unit activities of complex visual cortical cells were recorded from Brodmann's area 18 in immobilized, unanesthetized cats before, during, and after stimulation of the vestibular system. The vestibular system was stimulated by intravenous injection of deuterium oxide (D2O)--a noted nystagmogenic agent--or by direct galvanic stimulation of the labyrinth. Measures of the receptive-field areas, poststimulus time histograms, directional preferences, and the optimal speed of the light bar stimulating the cell were obtained before and after the application of D2O. Directional preferences were determined in a novel manner, using a method derived from a hierarchical clustering technique. Data were collected and analyzed from a) visual cortical cells in cats with intact labyrinths, b) visual cortical cells in cats following bilateral labrinthectomies, and c) nonvisual cortical cells in cats with intact labyrinths. The other cellular characteristics were also altered by the D2O. Galvanic stimulation of the labyrinth resembles, in its effects, the injection of D2O. In labyrinth-intact cats, the time course of area 18 spontaneous activity dramatically increased 30 min or more after D2O was administered. It peaked 2-3 h later and still had not returned to preinjection levels even 7 h after the D2O administration. In bilaterally labyrinthectomized cats, the spontaneous activity of the visual cells did not change following D2O administration. In nonvisual cells from labyrinth-intact cats, the spontaneous activity demonstrated a slight but significant decrease over time after D2O injection. In pilot studies, the cats were injected with D2O. Within 8-10 min afterward, signs of positional nystagmus commenced; and within 30 min, problems in maintaining balance were noted. This continued for 7-8 h before disappearing. In the labyrinthectomized animals, such effects were not observed.

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

    Directory of Open Access Journals (Sweden)

    Amir Abbas Ebrahimi

    2018-01-01

    Full Text Available 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.

  18. A vestibular phenotype for Waardenburg syndrome?

    Science.gov (United States)

    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.

  19. Gene therapy restores auditory and vestibular function in a mouse model of Usher syndrome type 1c.

    Science.gov (United States)

    Pan, Bifeng; Askew, Charles; Galvin, Alice; Heman-Ackah, Selena; Asai, Yukako; Indzhykulian, Artur A; Jodelka, Francine M; Hastings, Michelle L; Lentz, Jennifer J; Vandenberghe, Luk H; Holt, Jeffrey R; Géléoc, Gwenaëlle S

    2017-03-01

    Because there are currently no biological treatments for hearing loss, we sought to advance gene therapy approaches to treat genetic deafness. We focused on Usher syndrome, a devastating genetic disorder that causes blindness, balance disorders and profound deafness, and studied a knock-in mouse model, Ush1c c.216G>A, for Usher syndrome type IC (USH1C). As restoration of complex auditory and balance function is likely to require gene delivery systems that target auditory and vestibular sensory cells with high efficiency, we delivered wild-type Ush1c into the inner ear of Ush1c c.216G>A mice using a synthetic adeno-associated viral vector, Anc80L65, shown to transduce 80-90% of sensory hair cells. We demonstrate recovery of gene and protein expression, restoration of sensory cell function, rescue of complex auditory function and recovery of hearing and balance behavior to near wild-type levels. The data represent unprecedented recovery of inner ear function and suggest that biological therapies to treat deafness may be suitable for translation to humans with genetic inner ear disorders.

  20. Epidemiology and natural history of vestibular schwannomas

    DEFF Research Database (Denmark)

    Stangerup, Sven-Eric; Caye-Thomasen, Per

    2012-01-01

    This article describes various epidemiologic trends for vestibular schwannomas over the last 35 years, including a brief note on terminology. Additionally, it provides information on the natural history of tumor growth and hearing level following the diagnosis of a vestibular schwannoma. A treatm......This article describes various epidemiologic trends for vestibular schwannomas over the last 35 years, including a brief note on terminology. Additionally, it provides information on the natural history of tumor growth and hearing level following the diagnosis of a vestibular schwannoma...

  1. Peripheral Vestibular System Disease in Vestibular Schwannomas

    DEFF Research Database (Denmark)

    Møller, Martin Nue; Hansen, Søren; Caye-Thomasen, Per

    2015-01-01

    density of the peripheral vestibular nerve branches, and atrophy of the neuroepithelium of the vestibular end organs. In cases with small tumors, peripheral disease occurred only in the tissue structures innervated by the specific nerve from which the tumor originated. CONCLUSION: Vestibular schwannomas...... are associated with distinctive disease of the peripheral vestibular tissue structures, suggesting anterograde degeneration and that dizziness in these patients may be caused by deficient peripheral vestibular nerve fibers, neurons, and end organs. In smaller tumors, a highly localized disease occurs, which...

  2. Balance Training Enhances Vestibular Function and Reduces Overactive Proprioceptive Feedback in Elderly

    Directory of Open Access Journals (Sweden)

    Isabella K. Wiesmeier

    2017-08-01

    Full Text Available Objectives: Postural control in elderly people is impaired by degradations of sensory, motor, and higher-level adaptive mechanisms. Here, we characterize the effects of a progressive balance training program on these postural control impairments using a brain network model based on system identification techniques.Methods and Material: We analyzed postural control of 35 healthy elderly subjects and compared findings to data from 35 healthy young volunteers. Eighteen elderly subjects performed a 10 week balance training conducted twice per week. Balance training was carried out in static and dynamic movement states, on support surfaces with different elastic compliances, under different visual conditions and motor tasks. Postural control was characterized by spontaneous sway and postural reactions to pseudorandom anterior-posterior tilts of the support surface. Data were interpreted using a parameter identification procedure based on a brain network model.Results: With balance training, the elderly subjects significantly reduced their overly large postural reactions and approximated those of younger subjects. Less significant differences between elderly and young subjects' postural control, namely larger spontaneous sway amplitudes, velocities, and frequencies, larger overall time delays and a weaker motor feedback compared to young subjects were not significantly affected by the balance training.Conclusion: Balance training reduced overactive proprioceptive feedback and restored vestibular orientation in elderly. Based on the assumption of a linear deterioration of postural control across the life span, the training effect can be extrapolated as a juvenescence of 10 years. This study points to a considerable benefit of a continuous balance training in elderly, even without any sensorimotor deficits.

  3. Correlation between vestibular and autonomous function after 6 months of spaceflight: Data of the SPIN and GAZE-SPIN experiments.

    Science.gov (United States)

    Wuyts, Floris; Clement, Gilles; Naumov, Ivan; Kornilova, Ludmila; Glukhikh, Dmitriy; Hallgren, Emma; MacDougall, Hamish; Migeotte, Pierre-Francois; Delière, Quentin; Weerts, Aurelie; Moore, Steven; Diedrich, Andre

    In 13 cosmonauts, the vestibulo-autonomic reflex was investigated before and after 6 months duration spaceflight. Cosmonauts were rotated on the mini-centrifuge VVIS, which is installed in Star City. Initially, this mini-centrifuge flew on board of the Neurolab mission (STS-90), and served to generate intermittent artificial gravity during that mission, with apparent very positive effects on the preservation of the orthostatic tolerance upon return to earth in the 4 crew members that were subjected to the rotations in space. The current experiments SPIN and GAZE-SPIN are control experiments to test the hypothesis that intermittent artificial gravity in space can serve as a counter measure against several deleterious effects of microgravity. Additionally, the effect of microgravity on the gaze holding system is studied as well. Cosmonauts from a long duration stay in the International Space Station were tested on the VVIS (1 g centripetal interaural acceleration; consecutive right-ear-out anti-clockwise and left-ear-out clockwise measurement) on 5 different days. Two measurements were scheduled about one month and a half prior to launch and the remaining three immediately after their return from space (typically on R+2, R+4, R+9; R = return day from space). The ocular counter roll (OCR) as a measure of otolith function was measured on before, during and after the rotation in the mini centrifuge, using infrared video goggles. The perception of verticality was monitored using an ultrasound system. Gaze holding was tested before, during and after rotation. After the centrifugation part, the crew was installed on a tilt table, and instrumented with several cardiovascular recording equipment (ECG, continuous blood pressure monitoring, respiratory monitoring), as well as with impedance measurement devices to investigate fluid redistribution throughout the operational tilt test. To measure heart rate variability parameters, imposed breathing periods were included in the

  4. Quantification of vestibular-induced eye movements in zebrafish larvae

    Directory of Open Access Journals (Sweden)

    Mo Weike

    2010-09-01

    Full Text Available Abstract Background Vestibular reflexes coordinate movements or sensory input with changes in body or head position. Vestibular-evoked responses that involve the extraocular muscles include the vestibulo-ocular reflex (VOR, a compensatory eye movement to stabilize retinal images. Although an angular VOR attributable to semicircular canal stimulation was reported to be absent in free-swimming zebrafish larvae, recent studies reveal that vestibular-induced eye movements can be evoked in zebrafish larvae by both static tilts and dynamic rotations that tilt the head with respect to gravity. Results We have determined herein the basis of sensitivity of the larval eye movements with respect to vestibular stimulus, developmental stage, and sensory receptors of the inner ear. For our experiments, video recordings of larvae rotated sinusoidally at 0.25 Hz were analyzed to quantitate eye movements under infrared illumination. We observed a robust response that appeared as early as 72 hours post fertilization (hpf, which increased in amplitude over time. Unlike rotation about an earth horizontal axis, rotation about an earth vertical axis at 0.25 Hz did not evoke eye movements. Moreover, vestibular-induced responses were absent in mutant cdh23 larvae and larvae lacking anterior otoliths. Conclusions Our results provide evidence for a functional vestibulo-oculomotor circuit in 72 hpf zebrafish larvae that relies upon sensory input from anterior/utricular otolith organs.

  5. Variation in the Use of Vestibular Diagnostic Testing for Patients Presenting to Otolaryngology Clinics with Dizziness

    Science.gov (United States)

    Piker, Erin G.; Schulz, Kris; Parham, Kourosh; Vambutas, Andrea; Witsell, David; Tucci, Debara; Shin, Jennifer J.; Pynnonen, Melissa A.; Nguyen-Huynh, Anh; Crowson, Matthew; Ryan, Sheila E.; Langman, Alan; Roberts, Rhonda; Wolfley, Anne; Lee, Walter T.

    2016-01-01

    Objective We used a national otolaryngology practice–based research network database to characterize the utilization of vestibular function testing in patients diagnosed with dizziness and/or a vestibular disorder. Study Design Database review. Setting The Creating Healthcare Excellence through Education and Research (CHEER) practice-based research network of academic and community providers Subjects and Methods Dizzy patients in the CHEER retrospective database were identified through ICD-9 codes; vestibular testing procedures were identified with CPT codes. Demographics and procedures per patient were tabulated. Analysis included number and type of vestibular tests ordered, stratified by individual clinic and by practice type (community vs academic). Chi-square tests were performed to assess if the percentage of patients receiving testing was statistically significant across clinics. A logistic regression model was used to examine the association between receipt of testing and being tested on initial visit. Results A total of 12,468 patients diagnosed with dizziness and/or a vestibular disorder were identified from 7 community and 5 academic CHEER network clinics across the country. One-fifth of these patients had at least 1 vestibular function test. The percentage of patients tested varied widely by site, from 3% to 72%; academic clinics were twice as likely to test. Initial visit vestibular testing also varied, from 0% to 96% of dizzy patients, and was 15 times more likely in academic clinics. Conclusion There is significant variation in use and timing of vestibular diagnostic testing across otolaryngology clinics. The CHEER network research database does not contain outcome data. These results illustrate the critical need for research that examines outcomes as related to vestibular testing. PMID:27371625

  6. Exhibition of Stochastic Resonance in Vestibular Perception

    Science.gov (United States)

    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

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

    Science.gov (United States)

    D'Silva, Linda J; Lin, James; Staecker, Hinrich; Whitney, Susan L; Kluding, Patricia M

    2016-03-01

    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. © 2016 American Physical Therapy Association.

  8. Local gene therapy durably restores vestibular function in a mouse model of Usher syndrome type 1G.

    Science.gov (United States)

    Emptoz, Alice; Michel, Vincent; Lelli, Andrea; Akil, Omar; Boutet de Monvel, Jacques; Lahlou, Ghizlene; Meyer, Anaïs; Dupont, Typhaine; Nouaille, Sylvie; Ey, Elody; Franca de Barros, Filipa; Beraneck, Mathieu; Dulon, Didier; Hardelin, Jean-Pierre; Lustig, Lawrence; Avan, Paul; Petit, Christine; Safieddine, Saaid

    2017-09-05

    Our understanding of the mechanisms underlying inherited forms of inner ear deficits has considerably improved during the past 20 y, but we are still far from curative treatments. We investigated gene replacement as a strategy for restoring inner ear functions in a mouse model of Usher syndrome type 1G, characterized by congenital profound deafness and balance disorders. These mice lack the scaffold protein sans, which is involved both in the morphogenesis of the stereociliary bundle, the sensory antenna of inner ear hair cells, and in the mechanoelectrical transduction process. We show that a single delivery of the sans cDNA by the adenoassociated virus 8 to the inner ear of newborn mutant mice reestablishes the expression and targeting of the protein to the tips of stereocilia. The therapeutic gene restores the architecture and mechanosensitivity of stereociliary bundles, improves hearing thresholds, and durably rescues these mice from the balance defects. Our results open up new perspectives for efficient gene therapy of cochlear and vestibular disorders by showing that even severe dysmorphogenesis of stereociliary bundles can be corrected.

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

    Science.gov (United States)

    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. The function and molecular identity of inward rectifier channels in vestibular hair cells of the mouse inner ear

    Science.gov (United States)

    Levin, Michaela E.

    2012-01-01

    Inner ear hair cells respond to mechanical stimuli with graded receptor potentials. These graded responses are modulated by a host of voltage-dependent currents that flow across the basolateral membrane. Here, we examine the molecular identity and the function of a class of voltage-dependent ion channels that carries the potassium-selective inward rectifier current known as IK1. IK1 has been identified in vestibular hair cells of various species, but its molecular composition and functional contributions remain obscure. We used quantitative RT-PCR to show that the inward rectifier gene, Kir2.1, is highly expressed in mouse utricle between embryonic day 15 and adulthood. We confirmed Kir2.1 protein expression in hair cells by immunolocalization. To examine the molecular composition of IK1, we recorded voltage-dependent currents from type II hair cells in response to 50-ms steps from −124 to −54 in 10-mV increments. Wild-type cells had rapidly activating inward currents with reversal potentials close to the K+ equilibrium potential and a whole-cell conductance of 4.8 ± 1.5 nS (n = 46). In utricle hair cells from Kir2.1-deficient (Kir2.1−/−) mice, IK1 was absent at all stages examined. To identify the functional contribution of Kir2.1, we recorded membrane responses in current-clamp mode. Hair cells from Kir2.1−/− mice had significantly (P < 0.001) more depolarized resting potentials and larger, slower membrane responses than those of wild-type cells. These data suggest that Kir2.1 is required for IK1 in type II utricle hair cells and contributes to hyperpolarized resting potentials and fast, small amplitude receptor potentials in response to current inputs, such as those evoked by hair bundle deflections. PMID:22496522

  11. [Threefold intraoperative electrophysiological monitoring of vestibular neurectomy].

    Science.gov (United States)

    Hausler, R; Kasper, A

    1991-01-01

    A threefold intraoperative monitoring of facial nerve, auditory nerve and vestibular nerve function was performed in 14 cases of retrosigmoidal neurectomy. The facial nerve was monitoring with a pressure transducer placed against the cheek (Opalarm system). The auditory nerve was monitored with acoustically (click) evoked early potentials and the vestibular nerve was monitored with electrically evoked vestibular potentials obtained by direct stimulation (biphasic current pulses of 0.75-mA p-p, 100 us, 20/s) of the exposed vestibular nerve in the cerebellopontine angle before, during and after neurectomy. A characteristic vertex negative peak having a latency of approximately 2 ms and approximately 0.5 uV amplitude was obtained between a forehead and an ipsilateral ear lobe electrode (2 x 1,000 averaged responses over 10 ms) before the neurectomy. This response disappeared after selective vestibular nerve section proximal to the stimulation site. A diminished response amplitude was measured after incomplete nerve section. Simultaneous acoustic masking had no influence on the vestibular potential. The 14 operated patients became all free of vertiginous spells and drop-attacks except one patient who developed a contralateral Menière's. Facial nerve function remained normal in all. Hearing preservation was obtained in 12 patients (86%). The threefold intraoperative monitoring has turned out to be an additional safety factor for facial and auditory nerve preservation and, thanks to the recording of vestibular potentials, it increased the efficiency of vestibular neurectomy.

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

    Science.gov (United States)

    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/

  13. Neurophysiology of vestibular rehabilitation.

    Science.gov (United States)

    Hain, Timothy C

    2011-01-01

    The vestibular system is a sophisticated human control system. Accurate processing of sensory input about rapid head and postural motion is critical. Not surprisingly, the body uses multiple, partially redundant sensory inputs and motor outputs, combined with a very competent central repair capability. The system as a whole can adapt to substantial peripheral vestibular dysfunction. The Achilles' heel of the vestibular system is a relative inability to repair central vestibular dysfunction.

  14. Neurophysiology of vestibular rehabilitation

    OpenAIRE

    Hain Timothy, C.

    2011-01-01

    The vestibular system is a sophisticated human control system. Accurate processing of sensory input about rapid head and postural motion is critical. Not surprisingly, the body uses multiple, partially redundant sensory inputs and motor outputs, combined with a very competent central repair capability. The system as a whole can adapt to substantial peripheral vestibular dysfunction. The Achilles' heel of the vestibular system is a relative inability to repair central vestibular dysfunction.

  15. [Infrared videonystagmography in vestibular diagnosis].

    Science.gov (United States)

    Frisina, A; Piazza, F; Quaranta, N

    2000-01-01

    Vestibular examination relied upon electronystagmography (ENG) for more than 50 years. This method is based on recording of nystagmus (Ny) without any possibility to see the ocular movements directly. More recently, infrared videonystagmography (VNG) entered the diagnostic protocol of vestibular disorders. VNG permits to record and visualize Ny, both in the darkness and with open eyes. Aim of the present study was to verify the possible advantages of VNG versus ENG for functional evaluation of the vestibular system in patients suffering from otoneurological disorders. To that purpose, VNG and ENG tracings were recorded in 12 patients. The preliminary results show that there are not significant differences in quantitative evaluation of Ny between the two methods. Anyhow, VNG has some technical and clinical advantages that make it the method of choice.

  16. Facial nerve function after vestibular schwannoma surgery following failed conservative management

    DEFF Research Database (Denmark)

    Kaltoft, Mikkel; Stangerup, Sven-Eric; Cayé-Thomasen, Per

    2012-01-01

    the risk of impaired facial nerve function post-surgery. OBJECTIVE:: To compare facial nerve function in patients operated soon after diagnosis with patients allocated to conservative management, and the subgroup of these who later had surgery due to tumor growth. METHODS:: 1378 consecutive patients...... patients had normal facial nerve function at the end of observation. Good facial nerve outcome was found in 87 % of patients operated at diagnosis, and in 84 % of patients operated after established tumor growth. For the subgroup of small extrameatal tumors this difference was significant. Pooling all...... to preservation of the facial nerve function. Tumor growth during observation is found in only a minor proportion of the patients, and in these cases surgery or irradiation should be performed immediately....

  17. The Vestibular Effects of Repeated Low-Level Blasts.

    Science.gov (United States)

    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.

  18. Signal detection theory and vestibular perception: III. Estimating unbiased fit parameters for psychometric functions.

    Science.gov (United States)

    Chaudhuri, Shomesh E; Merfeld, Daniel M

    2013-03-01

    Psychophysics generally relies on estimating a subject's ability to perform a specific task as a function of an observed stimulus. For threshold studies, the fitted functions are called psychometric functions. While fitting psychometric functions to data acquired using adaptive sampling procedures (e.g., "staircase" procedures), investigators have encountered a bias in the spread ("slope" or "threshold") parameter that has been attributed to the serial dependency of the adaptive data. Using simulations, we confirm this bias for cumulative Gaussian parametric maximum likelihood fits on data collected via adaptive sampling procedures, and then present a bias-reduced maximum likelihood fit that substantially reduces the bias without reducing the precision of the spread parameter estimate and without reducing the accuracy or precision of the other fit parameters. As a separate topic, we explain how to implement this bias reduction technique using generalized linear model fits as well as other numeric maximum likelihood techniques such as the Nelder-Mead simplex. We then provide a comparison of the iterative bootstrap and observed information matrix techniques for estimating parameter fit variance from adaptive sampling procedure data sets. The iterative bootstrap technique is shown to be slightly more accurate; however, the observed information technique executes in a small fraction (0.005 %) of the time required by the iterative bootstrap technique, which is an advantage when a real-time estimate of parameter fit variance is required.

  19. Stereotactic radiotherapy for vestibular schwannoma

    DEFF Research Database (Denmark)

    Muzevic, Dario; Legcevic, Jelena; Splavski, Bruno

    2014-01-01

    BACKGROUND: Vestibular schwannomas (acoustic neuromas) are common benign tumours that arise from the Schwann cells of the vestibular nerve. Management options include observation with neuroradiological follow-up, microsurgical resection and stereotactic radiotherapy. OBJECTIVES: To assess...... the effect of stereotactic radiotherapy compared to observation, microsurgical resection, any other treatment modality, or a combination of two or more of the above approaches for vestibular schwannoma. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials; PubMed; EMBASE; CINAHL......; Web of Science; CAB Abstracts; ISRCTN and additional sources for published and unpublished trials. The date of the search was 24 July 2014. SELECTION CRITERIA: Randomised controlled trials (RCTs) exploring the efficacy of stereotactic radiotherapy compared with observation alone, microsurgical...

  20. Visuo-Vestibular Interactions

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  3. The Use of Computer-Assisted Home Exercises to Preserve Physical Function after a Vestibular Rehabilitation Program: A Randomized Controlled Study

    Directory of Open Access Journals (Sweden)

    Michael Smaerup

    2016-01-01

    Full Text Available Objective. The purpose of this study was to evaluate whether elderly patients with vestibular dysfunction are able to preserve physical functional level, reduction in dizziness, and the patient’s quality of life when assistive computer technology is used in comparison with printed instructions. Materials and Methods. Single-blind, randomized, controlled follow-up study. Fifty-seven elderly patients with chronic dizziness were randomly assigned to a computer-assisted home exercise program or to home exercises as described in printed instructions and followed for tree month after discharge from an outpatient clinic. Results. Both groups had maintained their high functional levels three months after finishing the outpatient rehabilitation. No statistically significant difference was found in outcome scores between the two groups. In spite of moderate compliance levels, the patients maintained their high functional level indicating that the elderly should not necessarily exercise for the first three months after termination of the training in the outpatient clinic. Conclusion. Elderly vestibular dysfunction patients exercising at home seem to maintain their functional level, level of dizziness, and quality of life three months following discharge from hospital. In this specific setup, no greater effect was found by introducing a computer-assisted training program, when compared to standard home training guided by printed instructions. This trial is registered with NCT01344408.

  4. Acute Bilateral Superior Branch Vestibular Neuropathy

    Directory of Open Access Journals (Sweden)

    Dario A. Yacovino

    2018-05-01

    Full Text Available The rapid onset of a bilateral vestibular hypofunction (BVH is often attributed to vestibular ototoxicity. However, without any prior exposure to ototoxins, the idiopathic form of BVH is most common. Although sequential bilateral vestibular neuritis (VN is described as a cause of BVH, clinical evidence for simultaneous and acute onset bilateral VN is unknown. We describe a patient with an acute onset of severe gait ataxia and oscillopsia with features compatible with acute BVH putatively due to a bilateral VN, which we serially evaluated with clinical and laboratory vestibular function testing over the course of 1 year. Initially, bilateral superior and horizontal semicircular canals and bilateral utricles were impaired, consistent with damage to both superior branches of each vestibular nerve. Hearing was spared. Only modest results were obtained following 6 months of vestibular rehabilitation. At a 1-year follow-up, only the utricular function of one side recovered. This case is the first evidence supporting an acute presentation of bilateral VN as a cause for BVH, which would not have been observed without critical assessment of each of the 10 vestibular end organs.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  7. A Pilot Study to Assess the Vestibular Apparatus Function with Videonystagmography During Chronic Otitis Media with Effusion.

    Science.gov (United States)

    Saliba, Issam; Dagher, Chady; El-Zir, Elie; Yammine, Fady G

    2015-01-01

    To assess the effect of chronic middle ear effusion (CMEE) on balance and equilibrium. Prospective study controlling two groups of children. The active arm consisted of children having a unilateral or bilateral CMEE that persisted for at least 3 months. The control group consisted of children presenting with normal middle ear. Children and parents in both groups were questioned about any symptom of vertigo, dizziness, disequilibrium or child's tendency to fall. ENT exam included an assessment with pneumatic and microscopic otoscopy, evaluation of the vestibular system with the Romberg test, the Fukuda test, the head-shaking test and the Starwalk test. The study group consisted of 15 children (mean = 6.5 years, SD = 2; 10 females and 5 males). The control group consisted also of 15 children (mean = 7.2 years, SD = 1.8; 8 females and 7 males). The duration of MEE was between 3 and 12 months (mean = 8 months). Three children (20%) in the study group had a history of vertigo, imbalance, disequilibrium and/or tendency to fall. None of the children in the control group had such a history (p = 0.22); Five children in the study group had abnormal head-shaking test, Fukuda and/or Starwalk tests (33.33%). Two children in the control group had such a finding (13.33%) (p = 0.39). Romberg test was normal in all children in both groups. In the study group, one child showed positional and spontaneous nystagmus on VNG testing. Another one showed positional nystagmus. Hence, 2 children had abnormal findings on VNG (13.33%). In the control group, VNG was normal in all children (p = 0.46). Tympanometry showed a type B curve in 26 ears, a type C curve in 3 ears and type A in one ear. In the control group all patients presented a type A curve. This paper describes the first study using VNG in a population of children with CMEE. The presence of balance disturbances associated or not with hearing loss is of paramount importance to the clinician as to the indications of myringotomy with a

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

    Science.gov (United States)

    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.

  9. Evaluation of Galvanic Vestibular Stimulation System

    Science.gov (United States)

    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

  10. Functional Testing of SLC26A4 Variants—Clinical and Molecular Analysis of a Cohort with Enlarged Vestibular Aqueduct from Austria

    Science.gov (United States)

    Bernardinelli, Emanuele; Nofziger, Charity; Patsch, Wolfgang; Rasp, Gerd; Paulmichl, Markus; Dossena, Silvia

    2018-01-01

    The prevalence and spectrum of sequence alterations in the SLC26A4 gene, which codes for the anion exchanger pendrin, are population-specific and account for at least 50% of cases of non-syndromic hearing loss associated with an enlarged vestibular aqueduct. A cohort of nineteen patients from Austria with hearing loss and a radiological alteration of the vestibular aqueduct underwent Sanger sequencing of SLC26A4 and GJB2, coding for connexin 26. The pathogenicity of sequence alterations detected was assessed by determining ion transport and molecular features of the corresponding SLC26A4 protein variants. In this group, four uncharacterized sequence alterations within the SLC26A4 coding region were found. Three of these lead to protein variants with abnormal functional and molecular features, while one should be considered with no pathogenic potential. Pathogenic SLC26A4 sequence alterations were only found in 12% of patients. SLC26A4 sequence alterations commonly found in other Caucasian populations were not detected. This survey represents the first study on the prevalence and spectrum of SLC26A4 sequence alterations in an Austrian cohort and further suggests that genetic testing should always be integrated with functional characterization and determination of the molecular features of protein variants in order to unequivocally identify or exclude a causal link between genotype and phenotype. PMID:29320412

  11. Patients with vestibular loss, tullio phenomenon, and pressure-induced nystagmus: vestibular atelectasis?

    Science.gov (United States)

    Wenzel, Angela; Ward, Bryan K; Schubert, Michael C; Kheradmand, Amir; Zee, David S; Mantokoudis, Georgios; Carey, John Patrick

    2014-06-01

    To propose an etiology for a syndrome of bilateral vestibular hypofunction and sound and/or pressure-evoked eye movements with normal hearing thresholds. Retrospective case series. Tertiary care referral center. Four patients with bilateral vestibular hypofunction, sound and/or pressure-evoked nystagmus and normal hearing thresholds were identified over a 3-year period. No evidence of other known vestibular disorders was identified. None of these patients presented with a history of exposure to toxins, radiation, aminoglycosides or chemotherapy; head trauma; or a family history of inherited vestibular loss. All patients underwent high-resolution CT scan of the temporal bones to evaluate for labyrinthine dehiscence. Additionally, all individuals underwent audiometric testing to ANSI standards, vestibular-evoked myogenic potentials (VEMP) testing using either click stimulus cervical VEMPs (cVEMPs), or tone burst ocular VEMPs (oVEMPs). Bithermal caloric stimulation was used to measure horizontal semicircular canal function, with either videonystagmography (VNG) or electronystagmography (ENG) to record eye movements. Individual responses of each of the 6 semicircular canals (SCC) to rapid head rotations were tested with the bedside head impulse test. We identified 4 patients with a combination of bilateral vestibular hypofunction and sound and/or pressure-induced eye movements, normal-hearing thresholds and no evidence for any other vestibular disorder. We suggest that this unique combination of symptoms should be considered as the clinical presentation of vestibular atelectasis, which has been previously described histologically as collapse of the endolymph-containing portions of the labyrinth.

  12. HASHIMOTO THYROIDITIS AND VESTIBULAR DYSFUNCTION.

    Science.gov (United States)

    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.

  13. Evaluation of diagnostic tests of the otolith organs and their application in various vestibular pathologies

    NARCIS (Netherlands)

    Winters, S.M.

    2014-01-01

    Current vestibular testing is limited. The general function of the vestibular system on both sides of the head can be tested, and one part of the peripheral vestibular organ, the horizontal semicircular canal, can be tested unilaterally. However, recently a test for the function of the otolith

  14. A review of the interrelationship between vestibular dysfunction ...

    African Journals Online (AJOL)

    functions, the effect of rehabilitation focused on the functioning of a specific canal, and the effect of different rehabilitation programmes on different vestibular deficiencies are suggested. Keywords: Vestibular dysfunction; Motor development; Learning disabilities; Posture; Rehabilitation and exercises. South African Journal ...

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

    Science.gov (United States)

    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.

  16. Unilateral vestibular loss impairs external space representation.

    Directory of Open Access Journals (Sweden)

    Liliane Borel

    Full Text Available The vestibular system is responsible for a wide range of postural and oculomotor functions and maintains an internal, updated representation of the position and movement of the head in space. In this study, we assessed whether unilateral vestibular loss affects external space representation. Patients with Menière's disease and healthy participants were instructed to point to memorized targets in near (peripersonal and far (extrapersonal spaces in the absence or presence of a visual background. These individuals were also required to estimate their body pointing direction. Menière's disease patients were tested before unilateral vestibular neurotomy and during the recovery period (one week and one month after the operation, and healthy participants were tested at similar times. Unilateral vestibular loss impaired the representation of both the external space and the body pointing direction: in the dark, the configuration of perceived targets was shifted toward the lesioned side and compressed toward the contralesioned hemifield, with higher pointing error in the near space. Performance varied according to the time elapsed after neurotomy: deficits were stronger during the early stages, while gradual compensation occurred subsequently. These findings provide the first demonstration of the critical role of vestibular signals in the representation of external space and of body pointing direction in the early stages after unilateral vestibular loss.

  17. Vestibular asymmetry predicts falls among elderly patients with multi-sensory dizziness.

    Science.gov (United States)

    Ekvall Hansson, Eva; Magnusson, Måns

    2013-07-22

    Dizziness is the most common symptom in elderly patients and has been identified as a risk factor for falls. While BPPV is the most common cause of dizziness among elderly, multisensory deficits is the second, with visual, vestibular and proprioceptive reduced function. Asymmetric vestibular function is overrepresented in elderly persons with hip fractures and wrist fractures and can be accessed for screening. In this prospective study with one year observation period, 55 patients (41 women, 14 men), 65 to 90 years old (median 80, interquartile range 11) with multisensory dizziness were included. Headshake test were pathologic in 24 patients, which substantially increased the risk of falls (OR 3.4). Thirteen of the 21 patients who had fallen (p = 0.03), and all 6 patients who sustained three falls or more (p = 0.04), had vestibular asymmetry. No other measure could predict the risk of falls (OR 0.55-1.71). Signs of vestibular asymmetry among elderly with multisensory dizziness could predict falls. Hence, it seems important to address fall-prevention programs to such a group of patients. Simple bedside tests of vestibular asymmetry might be a possibility to screen for one risk factor for falls among elderly.

  18. The Use of Computer-Assisted Home Exercises to Preserve Physical Function after a Vestibular Rehabilitation Program: A Randomized Controlled Study

    DEFF Research Database (Denmark)

    Brandt, Michael Smærup; Læssøe, Uffe; Grönvall, Erik

    2016-01-01

    . Materials and Methods. Single-blind, randomized, controlled follow-up study. Fifty-seven elderly patients with chronic dizziness were randomly assigned to a computer-assisted home exercise program or to home exercises as described in printed instructions and followed for tree month after discharge from......, and quality of life three months following discharge from hospital. In this specific setup, no greater effect was found by introducing a computer-assisted training program, when compared to standard home training guided by printed instructions. This trial is registered with NCT01344408.......Objective. The purpose of this study was to evaluate whether elderly patients with vestibular dysfunction are able to preserve physical functional level, reduction in dizziness, and the patient's quality of life when assistive computer technology is used in comparison with printed instructions...

  19. Prophylactic treatment of vestibular migraine

    Directory of Open Access Journals (Sweden)

    Márcio Cavalcante Salmito

    Full Text Available Abstract Introduction: Vestibular migraine (VM is now accepted as a common cause of episodic vertigo. Treatment of VM involves two situations: the vestibular symptom attacks and the period between attacks. For the latter, some prophylaxis methods can be used. The current recommendation is to use the same prophylactic drugs used for migraines, including β-blockers, antidepressants and anticonvulsants. The recent diagnostic definition of vestibular migraine makes the number of studies on its treatment scarce. Objective: To evaluate the efficacy of prophylactic treatment used in patients from a VM outpatient clinic. Methods: Review of medical records from patients with VM according to the criteria of the Bárány Society/International Headache Society of 2012 criteria. The drugs used in the treatment and treatment response obtained through the visual analog scale (VAS for dizziness and headache were assessed. The pre and post-treatment VAS scores were compared (the improvement was evaluated together and individually, per drug used. Associations with clinical subgroups of patients were also assessed. Results: Of the 88 assessed records, 47 were eligible. We included patients that met the diagnostic criteria for VM and excluded those whose medical records were illegible and those of patients with other disorders causing dizziness and/or headache that did not meet the 2012 criteria for VM. 80.9% of the patients showed improvement with prophylaxis (p < 0.001. Amitriptyline, Flunarizine, Propranolol and Topiramate improved vestibular symptoms (p < 0.001 and headache (p < 0.015. The four drugs were effective in a statistically significant manner. There was a positive statistical association between the time of vestibular symptoms and clinical improvement. There was no additional benefit in hypertensive patients who used antihypertensive drugs as prophylaxis or depressed patients who used antidepressants in relation to other prophylactic drugs. Drug

  20. Evaluation of postural control in unilateral vestibular hypofunction

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    Rafaela Maia Quitschal

    2014-07-01

    Full Text Available INTRODUCTION: Patients with vestibular hypofunction, a typical finding in peripheral vestibular disorders, show body balance alterations. OBJECTIVE: To evaluate the postural control of patients with vertigo and unilateral vestibular hypofunction. METHOD: This is a clinical cross-sectional study. Twenty-five patients with vertigo and unilateral vestibular hypofunction and a homogeneous control group consisting of 32 healthy individuals were submitted to a neurotological evaluation including the Tetrax Interactive Balance System posturography in eight different sensory conditions. RESULTS: For different positions, vertiginous patients with unilateral vestibular hypofunction showed significantly higher values of general stability index, weight distribution index, right/left and tool/heel synchronizations, Fourier transformation index and fall index than controls. CONCLUSION: Increased values in the indices of weight distribution, right/left and tool/heel synchronizations, Fourier transformation and fall risk characterize the impairment of postural control in patients with vertigo and unilateral vestibular hypofunction.

  1. Can a finding of cervical vestibular evoked myogenic potentials contribute to vestibular migraine diagnostics?

    Directory of Open Access Journals (Sweden)

    Tihana Vešligaj

    2016-02-01

    Full Text Available Aim To investigate differences in vestibular evoked myogenic potentials (VEMP results with patients suffering from vestibular migraine and healthy people, taking into consideration values of threshold and latency of occurrence of the characteristic wave complex, size of amplitude, and interaural amplitude ratio. According to the results, determine the importance and usefulness of VEMP in vestibular migraine diagnostics. Methods A total number of 62 subjects were included in the study, 32 of them belonging to a group of patients suffering from vestibular migraine (VM, while other 30 were in a control group of healthy subjects. Information was collected during the diagnostic evaluation. General and otoneurological history of patients and bedside tests, audiological results, videonystagmography and cervical vestibular evoked myogenic potentials (cVEMP were made. Results There was a difference in an interaural ratio of amplitudes in the experimental and control groups, but it was not found to be clinically significant. By ToneBurst 500 Hz method, the interaural amplitude ratio higher than 35% was measured in 46.97% subjects, while the response was totally unilaterally missing in 28.8% patients. Conclusion Even the sophisticated method as cVEMP does not give the ultimate result confirming the vestibular migraine diagnosis, and neither do other diagnostic methods. cVEMP result can contribute to the completion of full mosaic of vestibular migraine diagnostics.

  2. Morphology and electrophysiology of the vestibular organ in the guinea pig

    NARCIS (Netherlands)

    Oei, Markus Lee Yang Murti

    2003-01-01

    To obtain more information about the anatomy and function of the vestibular organ in normal and pathological conditions, evaluation methods are needed. For experimental purposes, the vestibular organ of the guinea pig is often used as a model for the human vestibular organ. The purpose of the

  3. Inner ear malformations in siblings presenting with vestibular ...

    African Journals Online (AJOL)

    Although the association between inner ear abnormalities and progressive sensorineural hearing loss is well known, vestibular signs or loss of vestibular function in these ... We provide a brief overview of the latest classification of these inner ear defects as well as a review of the literature pertaining to children with inner ear ...

  4. Angiogenesis in vestibular schwannomas

    DEFF Research Database (Denmark)

    Møller, Martin Nue; Werther, Kim; Nalla, Amarnadh

    2010-01-01

    Vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs) are potent mediators of tumor angiogenesis. It has been demonstrated that vestibular schwannoma VEGF expression correlates with tumor growth pattern, whereas knowledge on the expression of MMPs is lacking. This study...

  5. Vestibular involvement in adults with HIV/AIDS.

    Science.gov (United States)

    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

  6. Bedside examination for vestibular screening in occupational medicine.

    Science.gov (United States)

    Zamysłowska-Szmytke, Ewa; Szostek-Rogula, Sylwia; Śliwińska-Kowalska, Mariola

    2015-01-01

    The aim of the study was to assess the usefulness of bedside examination for screening of vestibular and balance system for occupational medicine purposes. Study group comprised 165 patients referred to Audiology and Phoniatric Clinic due to vestibular and/or balance problems. Caloric canal paresis of 19% was the cut off value to divide patients into 43 caloric-positive vestibular subjects and 122 caloric-negative patients. The latter group comprised 79 subjects revealing abnormalities of videonystagmographic (VNG) oculomotor tests (central group) and 43 subjects with normal VNG. Vestibular and balance symptoms were collected. Five tests were included to bedside examination: Romberg and Unterberger tests, Head Impulse Test (HIT), Dynamic Visual Acuity (DVA) and gaze nystagmus assessment. Vestibular and balance symptoms were reported by 82% of vestibular, 73% of central and 40% of VNG-normal patients. Thirteen out of 18 VNG-normal but symptomatic subjects (73%) had abnormal tests in clinical assessment. The sensitivity of bedside test set for vestibular pathology was 88% as compared to caloric test and 68% for central pathology as compared to VNG oculomotor tests. The combination of 5 bedside tests reveal satisfactory sensitivity to detect vestibular abnormalities. Bedside examination abnormalities are highly correlated with vestibular/balance symptoms, regardless the normal results of VNG. Thus, this method should be recommended for occupational medicine purposes. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  7. Bedside examination for vestibular screening in occupational medicine

    Directory of Open Access Journals (Sweden)

    Ewa Zamysłowska-Szmytke

    2015-04-01

    Full Text Available Objectives: The aim of the study was to assess the usefulness of bedside examination for screening of vestibular and balance system for occupational medicine purposes. Study group comprised 165 patients referred to Audiology and Phoniatric Clinic due to vestibular and/or balance problems. Caloric canal paresis of 19% was the cut off value to divide patients into 43 caloric-positive vestibular subjects and 122 caloric-negative patients. The latter group comprised 79 subjects revealing abnormalities of videonystagmographic (VNG oculomotor tests (central group and 43 subjects with normal VNG. Material and Methods: Vestibular and balance symptoms were collected. Five tests were included to bedside examination: Romberg and Unterberger tests, Head Impulse Test (HIT, Dynamic Visual Acuity (DVA and gaze nystagmus assessment. Results: Vestibular and balance symptoms were reported by 82% of vestibular, 73% of central and 40% of VNG-normal patients. Thirteen out of 18 VNG-normal but symptomatic subjects (73% had abnormal tests in clinical assessment. The sensitivity of bedside test set for vestibular pathology was 88% as compared to caloric test and 68% for central pathology as compared to VNG oculomotor tests. Conclusions: The combination of 5 bedside tests reveal satisfactory sensitivity to detect vestibular abnormalities. Bedside examination abnormalities are highly correlated with vestibular/balance symptoms, regardless the normal results of VNG. Thus, this method should be recommended for occupational medicine purposes.

  8. Deregulated genes in sporadic vestibular schwannomas

    DEFF Research Database (Denmark)

    Cayé-Thomasen, Per; Helweg-Larsen, Rehannah Holga Andrea; Stangerup, Sven-Eric

    2010-01-01

    In search of genes associated with vestibular schwannoma tumorigenesis, this study examines the gene expression in human vestibular nerve versus vestibular schwannoma tissue samples using microarray technology.......In search of genes associated with vestibular schwannoma tumorigenesis, this study examines the gene expression in human vestibular nerve versus vestibular schwannoma tissue samples using microarray technology....

  9. Hereditary familial vestibular degenerative diseases.

    NARCIS (Netherlands)

    Sun, J.; Alphen, A.M. van; Wagenaar, M.; Huygen, P.L.M.; Hoogenraad, C.C.; Hasson, T.; Koekkoek, S.K.; Bohne, B.A.; Zeeuw, C.I. de

    2001-01-01

    Identification of genes involved in hereditary vestibular disease is growing at a remarkable pace. Mutant mouse technology can be an important tool for understanding the biological mechanism of human vestibular diseases.

  10. Vestibular neuritis: three-dimensional videonystagmography and vestibular evoked myogenic potential results.

    Science.gov (United States)

    Chen, C W; Young, Y H; Wu, C H

    2000-10-01

    Eight patients diagnosed with vestibular neuritis received the newly developed three-dimensional videonystagmography (3D VNG) and vestibular evoked myogenic potential (VEMP) examination in order to localize the lesion site. Two (25%) of the 8 patients exhibited spontaneous nystagmus with 3 components, indicating that both the horizontal semicircular canal (HSCC) and anterior semicircular canal (ASCC) were affected. The remaining 6 patients (75%) displayed only horizontal nystagmus, meaning that only the HSCC was involved. Seven (88%) of the 8 patients had bilateral normal VEMPs, revealing sparing of the posterior semicircular canal (PSCC). In a comparative study, another seven patients with vestibular neuritis 1 year post-treatment also received the caloric test, 3D VNG and VEMP examination. Only one patient exhibited spontaneous nystagmus. An absent caloric response of the lesioned side persisted in 5 (71%) of the 7 patients. However, all patients showed normal VEMPs bilaterally. 3D VNG and VEMP examination indicates that vestibular neuritis mainly affects the superior division of the vestibular nerve, which innervates the HSCC and ASCC. Meanwhile, the function of the PSCC and saccule, innervated by the inferior vestibular nerve, is preserved.

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

    Science.gov (United States)

    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

  12. Vestibular System Evaluation: Results on Analysis of Vestibulony stagmography (VNG

    Directory of Open Access Journals (Sweden)

    Mitra Janghorban

    2015-04-01

    Full Text Available Objective: Falls are one of the major problems in the elderly and are considered one of the “Geriatric Giants”. Recurrent falls an important cause of morbidity and mortality in this segment of the population and is a marker of poor physical and cognitive status. The aim of the present study is to compare the VNG (Videonystagmography test results in adults with and without falls history. Materials & Methods: 60 adults ( 30 with one or more falls history and 30 without any falls history above 65 year old performed the VNG subtests included saccade, gaze, smooth pursuit, positional nystagmus, spontaneous nystagmus and caloric at rehabilitation faculty of Tehran University of Medical Sciences. Results: According to the data 74% of the faller group showed abnormal performance in the caloric subtest and more than 60% had abnormal results in the saccade, gaze and smooth pursuit subtests too. The members who suffered from central vestibular disorders had worse function than the others who suffered from peripheral vestibular ones. Conclusion: The non- faller group had better performance than the faller group in all of the subtests which indicates better vestibular system status in this group. According to the results, VNG performance can help guide the clinicians in the development of a safe exercise program.

  13. [The importance of vestibular evoked myogenic potentials for the assessment of the otolith function in the patients presenting with benign paroxysmal positional vertigo].

    Science.gov (United States)

    Kunel'skaya, N L; Baybakova, E V; Guseva, A L; Chugunova, M A; Manaenkova, E A

    The objective of the present study was to evaluate the otolith function in the patients presenting with idiopathic benign paroxysmal positional vertigo (pBPPV) attributable to the occlusion of the posterior semicircular canal (PSCC) of the inner ear with the use of vestibular evoked myogenic potentials (VEMP). Cervical (cVEMP) and ocular VEMP (oVEMP) were measured in 34 patients with idiopathic pBPPV before and 7 days after the treatment by means of reposition maneuvers. The results of the repeated Dix-Hallpike test performed 7 days after the repositioning maneuver were negative in 27 patients and positive in 7 patients. There was no statistically significant difference in the amplitude of cervical VEMP between the healthy and affected ears either before or after the repositioning treatment. The measurement of oVEMP revealed a reduction of the response amplitude on the affected side. The average values of the plnl on the healthy side were 12.84±1.09 and those on the affected side 4.62±0.69 (potolith function.

  14. Update on the status of rehabilitative countermeasures to ameliorate the effects of long-duration exposure to microgravity on vestibular and sensorimotor function.

    Science.gov (United States)

    Cohen, Helen S

    2003-01-01

    This paper is an overview of current research on development of rehabilitative countermeasures to ameliorate the effects of long-term exposure to microgravity on sensorimotor function during space flight. After many years of work we do not yet have operational countermeasures, probably for several reasons: 1) changes in the use of vestibular input are manifested in many ways, 2) due to multiple mechanisms for funding research, investigators doing related research may not coordinate their work, and 3) relatively few scientists work on this problem. The number of investigators and physicians who routinely deal with the functional problems of astronauts and the limitations of working in the space environment is tiny; the number of investigators who are therapists, and who therefore have experience and expertise in developing rehabilitation programs, is miniscule. That's the bad news. The good news is that as a group, we are little but mighty. Therefore, the entire group of investigators can plan to take a more coordinated, collaborative approach than investigators in larger fields. Also, serendipitously, individual research groups have begun approaching different rehabilitative aspects of this problem. If we make a greater effort toward a coordinated, multidimensional approach, guided by rehabilitation concepts, we will be able to provide operational sensorimotor countermeasures when they are needed.

  15. Acute Unilateral Vestibular Failure Does Not Cause Spatial Hemineglect.

    Directory of Open Access Journals (Sweden)

    Julian Conrad

    Full Text Available 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.

  16. Vestibular Compensation in Unilateral Patients Often Causes Both Gain and Time Constant Asymmetries in The VOR

    Directory of Open Access Journals (Sweden)

    Mina eRanjbaran

    2016-03-01

    Full Text Available The vestibulo-ocular reflex (VOR is essential in our daily life to stabilize retinal images during head movements. Balanced vestibular functionality secures optimal reflex performance which can be distorted in case of peripheral vestibular lesions. Luckily, vestibular compensation in different neuronal sites restores VOR function to some extent over time. Studying vestibular compensation gives insight into the possible mechanisms for plasticity in the brain.In this work, novel experimental analysis tools are employed to reevaluate the VOR characteristics following unilateral vestibular lesions and compensation. Our results suggest that following vestibular lesions, asymmetric performance of the VOR is not only limited to its gain. Vestibular compensation also causes asymmetric dynamics, i.e. different time constants for the VOR during leftward or rightward passive head rotation. Potential mechanisms for these experimental observations are provided using simulation studies.

  17. Clinical Significance of the Presence of Autonomic and Vestibular Dysfunction in Diabetic Patients with Peripheral Neuropathy

    Directory of Open Access Journals (Sweden)

    Soo Kyoung Kim

    2012-02-01

    Full Text Available BackgroundWe investigated the prevalence of diabetic autonomic neuropathy (DAN and vestibular dysfunction (VD in diabetic patients with peripheral neuropathy.MethodsThirty-five diabetic patients with peripheral neuropathy were enrolled from August 2008 to July 2009. All subjects underwent autonomic function tests. Nineteen of the patients (54.3% underwent videonystagmography.ResultsDiabetic autonomic neuropathy was observed in 28 patients (80%. A mild degree of autonomic failure was observed in 18 patients (64.3%, and a moderate degree of autonomic failure was observed in ten patients (35.7%. Factors related to DAN included diabetic nephropathy (P=0.032, degree of chronic kidney disease (P=0.003, and duration of diabetes (P=0.044. Vestibular dysfunction was observed in 11 of 19 patients (57.9%. There was no significant association between DAN and VD.ConclusionDiabetic autonomic neuropathy was observed in 28 diabetic patients (80% with peripheral neuropathy. Vestibular dysfunction was observed in nearly 60% of diabetic patients with peripheral neuropathy who complained of dizziness but showed no significant association with DAN. Diabetic patients who complained of dizziness need to examine both autonomic function and vestibular function.

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

    Science.gov (United States)

    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.

  19. [Clinical research of vestibular autorotation test for patients with vertebrobasilar insufficiency].

    Science.gov (United States)

    Chen, Tai-sheng; Wang, Wen-hong; Song, Wei; Lu, Hong-hua; Zuo, Xian-hua; Zhang, Jin-mei

    2006-10-01

    To explore the diagnostic values of vestibular autorotation test (VAT) for patients with vertebrobasilar insufficiency (VBI). VAT and videonystagmography ( VNG) were performed on 73 patients with VBI and 48 patients with peripheral vestibular lesions (contrast group). Parameters analyzed included Gain, phase and asymmetry of VAT, as well as the canal paresis (CP) of caloric test and results of optokinetic-pursuit tests in VNG. Positive result of the test could be defined if anyone of the parameters was abnormal. For VAT test, Gain was enhanced in VBI group and was reduced in contrast group. In VBI group and contrast group, Gain enhanced showed in 47 (64.4%) cases and 5 (10.4%) cases, respectively (chi2 = 31.19, P VNG test, results with optokinetic-pursuit tests were more abnormal in VBI group than that in contrast group, which showed central lesions characteristics. Forty-four cases (60.3%) in VBI group and 10 cases (20.8%) in control group showed central lesions results with optokinetic-pursuit tests and visual fixation test (chi2 = 15.89, P < 0.01). Unilateral or bilateral CP showed in 33 cases (68.6%) in control group and 51 cases (69.9%) in VBI group with caloric test. Gain of VAT is mostly enhanced in VBI group, and Gain as a main characteristic is reduced in patients with peripheral vestibular lesions. The Gain parameter is availability for assessing characteristics of vestibular lesions. Phase and asymmetry can be used to assess the vestibular function but can not indicate the characteristics of vestibular lesions.

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

    Science.gov (United States)

    Grassi, S; Pettorossi, V E

    2001-08-01

    potentiation. Finally the fifth part suggests the possible functional significance of different action times of the two retrograde messengers and metabotropic glutamate receptors, which are involved in mediating the presynaptic mechanism sustaining vestibular long-term potentiation.

  1. STATE ANXIETY, SUBJECTIVE IMBALANCE AND HANDICAP IN VESTIBULAR SCHWANNOMA

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    Yougan Saman

    2016-07-01

    Full Text Available ABSTRACTEvidence is emerging of a significant clinical and neuro-anatomical 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. Aims1.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. MethodsTwo separate cohorts Vestibular Schwannoma (VS patients underwent vestibular tests (electronystagmography, cervical and ocular vestibular evoked myogenic potentials and caloric responses and questionnaire assessment (Vertigo handicap Questionnaire, Vertigo Symptom Scale, State Trait Anxiety InventoryFifteen post resection Vestibular schwannoma 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 and with preserved vestibular function 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 afterwards 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 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.ResultsIn experiment 1, a significant difference (p<0.01 was found when comparing

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

    Science.gov (United States)

    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

  3. Relationship of vestibular balancing function to executive function in children with attention-deficit/hyperactivity disorder%注意缺陷多动障碍儿童的前庭平衡功能与执行功能

    Institute of Scientific and Technical Information of China (English)

    李静; 程嘉; 丰雷; 王玉凤

    2012-01-01

    目的:探讨不同前庭平衡功能状态的8~10岁注意缺陷多动障碍(ADHD)儿童的执行功能特点.方法:对符合美国精神障碍诊断与统计手册第4版( DSM-Ⅳ)诊断标准的143名ADHD儿童,采用Stroop色字命名任务、Rey复杂图形记忆、连线测试、汉诺塔、言语流畅性任务、数字广度、心理推理能力任务测查执行功能.采用人体动静态姿势测试仪,选用感觉整合测试(SOT)评定平衡功能,以前庭感觉分的中位数为界,分为平衡功能好组(n=71)与平衡差组(n=72).结果:平衡功能好组的Stroop字义命名完成时间[(19.3±5.2) svs.(21.8±8.1)s]、色字命字完成时间[(24.8±8.0)svs.(28.8±11.9)s]均少于平衡功能差组(均P<0.05);平衡功能好组汉诺塔任务完成率高于(78.9% vs.63.9%)平衡功能差组,汉诺塔任务犯规次数[1(0,2)vs.1(1,3)]少于平衡功能差组(均P<0.05).在Rey复杂图形记忆、连线测试、数字广度、心理推理能力任务比较中,两组差异无统计学意义.结论:前庭平衡功能差的ADHD儿童,其执行功能的抑制、计划能力受损更明显.%Objective: To explore the characteristics of executive function of attention deficit hyperactivity disorder (ADHD) children in S to 10 years with varying vestibular balancing status. Methods: Totally 143 children who were diagnosed as ADHD according to the criteria of Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) were selected. They were assessed with the executive function including Stroop color-word test, Rey-Osterrieth complex figure test, Trail Making Test, Tower of Hanoi task, verbal fluency test, Digital Span, theory of mind tests(deceptive container task and false-belief task), and balancing function using SMART EQUITEST Balance Master 8.0 with Sensory Organization Test (SOT). The subjects were divided into two groups according to their vestibular perception scores. The subject whose score was above the median was

  4. Significant vestibular system impairment is common in a cohort of elderly patients referred for assessment of falls risk.

    Science.gov (United States)

    Jacobson, Gary P; McCaslin, Devin L; Grantham, Sarah L; Piker, Erin G

    2008-01-01

    Falls in elderly patients are associated with morbidity, mortality, and cost to the healthcare system. The development of falls risk assessment programs have represented a method of responding to what is known about injurious falls. The multidimensional assessments involve the comparison against normative data of a patient's performance on metrics known to influence the likelihood of future falls. The factors assessed usually include falls and medication history, measures of mentation, depression, orthostatic hypotension, simple or choice reaction time, gait stability, postural stability, and the integrity of the patient's vision, somesthetic, and vestibular senses. This investigation was conducted to measure the proportion of patients referred for falls risk assessment who have evidence of vestibular system impairment. Qualitative, retrospective review of data collected from 2003 to 2007. The cohort was 185 consecutive patients referred for multidimensional assessments of falls risk. Patients underwent quantitative assessments of peripheral and central vestibular system function consisting of electro- or videonystagmography (i.e., ENG/VNG), and sinusoidal harmonic acceleration testing. Results of these tests were compared to normative data. We found that 73% of the sample who underwent vestibular system assessment had quantitative evidence of either peripheral or central vestibular system impairment. Our results suggest that quantitative assessments of the vestibulo-ocular reflex should be conducted on patients who are evaluated for falls risk. These examinations should include at least caloric testing and, where available, rotational testing.

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

    Science.gov (United States)

    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 vertigo, as well as differences in the prevention and self-control of the patients against the vertigo.

  6. [Vestibular testing abnormalities in individuals with motion sickness].

    Science.gov (United States)

    Ma, Yan; Ou, Yongkang; Chen, Ling; Zheng, Yiqing

    2009-08-01

    To evaluate the vestibular function of motion sickness. VNG, which tests the vestibular function of horizontal semicircular canal, and CPT, which tests vestibulospinal reflex and judge proprioceptive, visual and vestibular status, were performed in 30 motion sickness patients and 20 healthy volunteers (control group). Graybiel score was recorded at the same time. Two groups' Graybiel score (12.67 +/- 11.78 vs 2.10 +/- 6.23; rank test P<0.05), caloric test labyrinth value [(19.02 +/- 8.59) degrees/s vs (13.58 +/- 5.25) degrees/s; t test P<0.05], caloric test labyrinth value of three patients in motion sickness group exceeded 75 degrees/s. In computerized posturography testing (CPT), motion sickness patients were central type (66.7%) and disperse type (23.3%); all of control group were central type. There was statistical significance in two groups' CTP area, and motion sickness group was obviously higher than control group. While stimulating vestibulum in CPT, there was abnormality (35%-50%) in motion sickness group and none in control group. Generally evaluating CPT, there was only 2 proprioceptive hypofunction, 3 visual hypofunction, and no vestibular hypofunction, but none hypofunction in control group. Motion sickness patients have high vestibular susceptible, some with vestibular hyperfunction. In posturography, a large number of motion sickness patients are central type but no vestibular hypofunction, but it is hard to keep balance when stimulating vestibulum.

  7. Effects of vibrotactile vestibular substitution on vestibular rehabilitation - preliminary study,

    Directory of Open Access Journals (Sweden)

    Cibele Brugnera

    2015-12-01

    Full Text Available ABSTRACT INTRODUCTION: Some patients with severe impairment of body balance do not obtain adequate improvement from vestibular rehabilitation (VR. OBJECTIVE: To evaluate the effectiveness of Vertiguard(tm biofeedback equipment as a sensory substitution (SS of the vestibular system in patients who did not obtain sufficient improvement from VR. METHODS: This was a randomized prospective clinical study. Thirteen patients without satisfactory response to conventional VR were randomized into a study group (SG, which received the vibrotactile stimulus from Vertiguard(tm for ten days, and a control group (CG, which used equipment without the stimulus. For pre- and post-treatment assessment, the Sensory Organization Test (SOT protocol of the Computerized Dynamic Posturography (CDP and two scales of balance self-perception, Activities-specific Balance Confidence (ABC and Dizziness Handicap Inventory (DHI, were used. RESULTS: After treatment, only the SG showed statistically significant improvement in C5 (p = 0.007 and C6 (p = 0.01. On the ABC scale, there was a significant difference in the SG (p= 0.04. The DHI showed a significant difference in CG and SG with regard to the physical aspect, and only in the SG for the functional aspect (p = 0.04. CONCLUSION: The present findings show that sensory substitution using the vibrotactile stimulus of the Vertiguard(tm system helped with the integration of neural networks involved in maintaining posture, improving the strategies used in the recovery of body balance.

  8. Interaural difference values of vestibular evoked myogenic.

    Directory of Open Access Journals (Sweden)

    Marziyeh Moallemi

    2015-01-01

    Full Text Available Migraine is a neurologic disease, which often is associated with a unilateral headache. Vestibular abnormalities are common in migraine. Vestibular evoked myogenic potentials (VEMPs assess otolith function in particular functional integrity of the saccule and the inferior vestibular nerve. We used VEMP to evaluate if the migraine headache can affect VEMP asymmetry parameters. A total of 25 patients with migraine (22 females and 3 males who were diagnosed according to the criteria of IHS-1988 were enrolled in this cross-sectional study. Control group consisted of 26 healthy participants (18 female and 8 male, without neurotological symptoms and history of migraine. The short tone burst (95 dB nHL, 500 Hz was presented to ears. VEMP was recorded with surface electromyography over the contracted ipsilateral sternocleidomastoid (SCM muscle. Although current results showed that the amplitude ratio is greater in migraine patients than normal group, there was no statistical difference between two groups in mean asymmetry parameters of VEMP. Asymmetry measurements in vestibular evoked myogenic potentials probably are not indicators of unilateral deficient in saccular pathways of migraine patients.

  9. New insights into pathophysiology of vestibular migraine

    Directory of Open Access Journals (Sweden)

    Juan Manuel Espinosa-Sanchez

    2015-02-01

    Full Text Available Vestibular migraine (VM is a common disorder in which genetic, epigenetic and environmental factors probably contribute to its development. The pathophysiology of VM is unknown; nevertheless in the last few years, several studies are contributing to understand the neurophysiological pathways involved in VM. The current hypotheses are mostly based on the knowledge of migraine itself. The evidence of trigeminal innervation of the labyrinth vessels and the localization of vasoactive neuropeptides in the perivascular afferent terminals of these trigeminal fibers support the involvement of the trigemino-vascular system. The neurogenic inflammation triggered by activation of the trigeminal-vestibulocochlear reflex, with the subsequent inner ear plasma protein extravasation and the release of inflammatory mediators, can contribute to a sustained activation and sensitization of the trigeminal primary afferent neurons explaining VM symptoms. The reciprocal connections between brainstem vestibular nuclei and the structures that modulate trigeminal nociceptive inputs (rostral ventromedial medulla, ventrolateral periaqueductal grey, locus coeruleus and nucleus raphe magnus are critical to understand the pathophysiology of VM. Although cortical spreading depression can affect cortical areas involved in processing vestibular information, functional neuroimaging techniques suggest a dysmodulation in the multimodal sensory integration and processing of vestibular and nociceptive information, resulting from a vestibulo-thalamo-cortical dysfunction, as the pathogenic mechanism underlying VM. The elevated prevalence of VM suggests that multiple functional variants may confer a genetic susceptibility leading to a dysregulation of excitatory-inhibitory balance in brain structures involved in the processing of sensory information, vestibular inputs and pain. The interactions among several functional and structural neural networks could explain the pathogenic

  10. Vestibular asymmetry predicts falls among elderly patients with multi- sensory dizziness

    OpenAIRE

    Ekvall Hansson, Eva; Magnusson, M?ns

    2013-01-01

    Background: Dizziness is the most common symptom in elderly patients and has been identified as a risk factor for falls. While BPPV is the most common cause of dizziness among elderly, multisensory deficits is the second, with visual, vestibular and proprioceptive reduced function. Asymmetric vestibular function is overrepresented in elderly persons with hip fractures and wrist fractures and can be accessed for screening. The objective was to study if vestibular asymmetry, vibration sense, ba...

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

    Science.gov (United States)

    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

  12. Drug therapy for peripheral vestibular vertigo

    Directory of Open Access Journals (Sweden)

    L. M. Antonenko

    2017-01-01

    Full Text Available The choice of effective treatments for vestibular vertigo is one of the important problems, by taking into account the high prevalence of peripheral vestibular diseases. Different drugs, such as vestibular suppressants for the relief of acute vertigo attacks and vestibular compensation stimulants for rehabilitation treatment, are used to treat vestibular vertigo. Drug therapy in combination with vestibular exercises is effective in patients with vestibular neuronitis, Meniere's disease, so is that with therapeutic maneuvers in patients with benign paroxysmal positional vertigo. The high therapeutic efficacy and safety of betahistines permit their extensive use for the treatment of various vestibular disorders.

  13. Vestibular feedback maintains reaching accuracy during body movement

    Science.gov (United States)

    Reynolds, Raymond F.

    2016-01-01

    Key points Reaching movements can be perturbed by vestibular input, but the function of this response is unclear.Here, we applied galvanic vestibular stimulation concurrently with real body movement while subjects maintained arm position either fixed in space or fixed with respect to their body.During the fixed‐in‐space conditions, galvanic vestibular stimulation caused large changes in arm trajectory consistent with a compensatory response to maintain upper‐limb accuracy in the face of body movement.Galvanic vestibular stimulation responses were absent during the body‐fixed task, demonstrating task dependency in vestibular control of the upper limb.The results suggest that the function of vestibular‐evoked arm movements is to maintain the accuracy of the upper limb during unpredictable body movement, but only when reaching in an earth‐fixed reference frame. Abstract When using our arms to interact with the world, unintended body motion can introduce movement error. A mechanism that could detect and compensate for such motion would be beneficial. Observations of arm movements evoked by vestibular stimulation provide some support for this mechanism. However, the physiological function underlying these artificially evoked movements is unclear from previous research. For such a mechanism to be functional, it should operate only when the arm is being controlled in an earth‐fixed rather than a body‐fixed reference frame. In the latter case, compensation would be unnecessary and even deleterious. To test this hypothesis, subjects were gently rotated in a chair while being asked to maintain their outstretched arm pointing towards either earth‐fixed or body‐fixed memorized targets. Galvanic vestibular stimulation was applied concurrently during rotation to isolate the influence of vestibular input, uncontaminated by inertial factors. During the earth‐fixed task, galvanic vestibular stimulation produced large polarity‐dependent corrections in arm

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

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    Erika Celis-Aguilar

    Full Text Available Abstract Introduction: 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. Objective: To control intractable vertigo through complete saccular and horizontal canal vestibular ablation with intratympanic gentamicin treatment. Methods: 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 0.5-0.8 mL of gentamicin intratympanic application at a 30 mg/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. Results: 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 >30 dB. Conclusions: 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.

  15. [Presbyastasis and application of vestibular rehabilitation in geriatrics].

    Science.gov (United States)

    Costa de Araujo, P; Demanez, L; Lechien, J; Bauvir, P; Petermans, J

    2011-03-01

    Balance disorders can have a major functional impact among the elderly. The main risk is falling. Three elements are implicated in the loss of balance: vision, proprioception and the vestibular system. This article will discuss mainly vestibular damage and its implications. The assessment of balance disorders, particularly in geriatric patients, is based on validated scales composed of several items. These provide scores and are based on the results of chronometric measurements. They can be useful for the application of Vestibular Rehabilitation (VR), a technique improving the adaptation and autonomy of these patients. Vestibular rehabilitation is therefore part of an overall support, the goal of therapy being to improve daily life and to reduce the risk of falls.

  16. True incidence of vestibular schwannoma?

    DEFF Research Database (Denmark)

    Stangerup, Sven-Eric; Tos, Mirko; Thomsen, Jens

    2010-01-01

    The incidence of diagnosed sporadic unilateral vestibular schwannomas (VS) has increased, due primarily to more widespread access to magnetic resonance imaging.......The incidence of diagnosed sporadic unilateral vestibular schwannomas (VS) has increased, due primarily to more widespread access to magnetic resonance imaging....

  17. Postural threat differentially affects the feedforward and feedback components of the vestibular-evoked balance response.

    Science.gov (United States)

    Osler, Callum J; Tersteeg, M C A; Reynolds, Raymond F; Loram, Ian D

    2013-10-01

    Circumstances may render the consequence of falling quite severe, thus maximising the motivation to control postural sway. This commonly occurs when exposed to height and may result from the interaction of many factors, including fear, arousal, sensory information and perception. Here, we examined human vestibular-evoked balance responses during exposure to a highly threatening postural context. Nine subjects stood with eyes closed on a narrow walkway elevated 3.85 m above ground level. This evoked an altered psycho-physiological state, demonstrated by a twofold increase in skin conductance. Balance responses were then evoked by galvanic vestibular stimulation. The sway response, which comprised a whole-body lean in the direction of the edge of the walkway, was significantly and substantially attenuated after ~800 ms. This demonstrates that a strong reason to modify the balance control strategy was created and subjects were highly motivated to minimise sway. Despite this, the initial response remained unchanged. This suggests little effect on the feedforward settings of the nervous system responsible for coupling pure vestibular input to functional motor output. The much stronger, later effect can be attributed to an integration of balance-relevant sensory feedback once the body was in motion. These results demonstrate that the feedforward and feedback components of a vestibular-evoked balance response are differently affected by postural threat. Although a fear of falling has previously been linked with instability and even falling itself, our findings suggest that this relationship is not attributable to changes in the feedforward vestibular control of balance. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  18. Hoxb1 controls anteroposterior identity of vestibular projection neurons.

    Science.gov (United States)

    Chen, Yiju; Takano-Maruyama, Masumi; Fritzsch, Bernd; Gaufo, Gary O

    2012-01-01

    The vestibular nuclear complex (VNC) consists of a collection of sensory relay nuclei that integrates and relays information essential for coordination of eye movements, balance, and posture. Spanning the majority of the hindbrain alar plate, the rhombomere (r) origin and projection pattern of the VNC have been characterized in descriptive works using neuroanatomical tracing. However, neither the molecular identity nor developmental regulation of individual nucleus of the VNC has been determined. To begin to address this issue, we found that Hoxb1 is required for the anterior-posterior (AP) identity of precursors that contribute to the lateral vestibular nucleus (LVN). Using a gene-targeted Hoxb1-GFP reporter in the mouse, we show that the LVN precursors originate exclusively from r4 and project to the spinal cord in the stereotypic pattern of the lateral vestibulospinal tract that provides input into spinal motoneurons driving extensor muscles of the limb. The r4-derived LVN precursors express the transcription factors Phox2a and Lbx1, and the glutamatergic marker Vglut2, which together defines them as dB2 neurons. Loss of Hoxb1 function does not alter the glutamatergic phenotype of dB2 neurons, but alters their stereotyped spinal cord projection. Moreover, at the expense of Phox2a, the glutamatergic determinants Lmx1b and Tlx3 were ectopically expressed by dB2 neurons. Our study suggests that the Hox genes determine the AP identity and diversity of vestibular precursors, including their output target, by coordinating the expression of neurotransmitter determinant and target selection properties along the AP axis.

  19. Hoxb1 controls anteroposterior identity of vestibular projection neurons.

    Directory of Open Access Journals (Sweden)

    Yiju Chen

    Full Text Available The vestibular nuclear complex (VNC consists of a collection of sensory relay nuclei that integrates and relays information essential for coordination of eye movements, balance, and posture. Spanning the majority of the hindbrain alar plate, the rhombomere (r origin and projection pattern of the VNC have been characterized in descriptive works using neuroanatomical tracing. However, neither the molecular identity nor developmental regulation of individual nucleus of the VNC has been determined. To begin to address this issue, we found that Hoxb1 is required for the anterior-posterior (AP identity of precursors that contribute to the lateral vestibular nucleus (LVN. Using a gene-targeted Hoxb1-GFP reporter in the mouse, we show that the LVN precursors originate exclusively from r4 and project to the spinal cord in the stereotypic pattern of the lateral vestibulospinal tract that provides input into spinal motoneurons driving extensor muscles of the limb. The r4-derived LVN precursors express the transcription factors Phox2a and Lbx1, and the glutamatergic marker Vglut2, which together defines them as dB2 neurons. Loss of Hoxb1 function does not alter the glutamatergic phenotype of dB2 neurons, but alters their stereotyped spinal cord projection. Moreover, at the expense of Phox2a, the glutamatergic determinants Lmx1b and Tlx3 were ectopically expressed by dB2 neurons. Our study suggests that the Hox genes determine the AP identity and diversity of vestibular precursors, including their output target, by coordinating the expression of neurotransmitter determinant and target selection properties along the AP axis.

  20. Early and phasic cortical metabolic changes in vestibular neuritis onset.

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    Marco Alessandrini

    Full Text Available Functional brain activation studies described the presence of separate cortical areas responsible for central processing of peripheral vestibular information and reported their activation and interactions with other sensory modalities and the changes of this network associated to strategic peripheral or central vestibular lesions. It is already known that cortical changes induced by acute unilateral vestibular failure (UVF are various and undergo variations over time, revealing different cortical involved areas at the onset and recovery from symptoms. The present study aimed at reporting the earliest change in cortical metabolic activity during a paradigmatic form of UVF such as vestibular neuritis (VN, that is, a purely peripheral lesion of the vestibular system, that offers the opportunity to study the cortical response to altered vestibular processing. This research reports [(18F]fluorodeoxyglucose positron emission tomography brain scan data concerning the early cortical metabolic activity associated to symptoms onset in a group of eight patients suffering from VN. VN patients' cortical metabolic activity during the first two days from symptoms onset was compared to that recorded one month later and to a control healthy group. Beside the known cortical response in the sensorimotor network associated to vestibular deafferentation, we show for the first time the involvement of Entorhinal (BAs 28, 34 and Temporal (BA 38 cortices in early phases of symptomatology onset. We interpret these findings as the cortical counterparts of the attempt to reorient oneself in space counteracting the vertigo symptom (Bas 28, 34 and of the emotional response to the new pathologic condition (BA 38 respectively. These interpretations were further supported by changes in patients' subjective ratings in balance, anxiety, and depersonalization/derealization scores when tested at illness onset and one month later. The present findings contribute in expanding

  1. Removal of vestibular schwannoma and facial nerve preservation using small suboccipital retrosigmoid craniotomy

    Institute of Scientific and Technical Information of China (English)

    CHEN Ling; CHEN Li-hua; LING Feng; LIU Yun-sheng; Madjid Samii; Amir Samii

    2010-01-01

    Background Vestibular schwannoma, the commonest form of intracranial schwannoma, arises from the Schwann cells investing the vestibular nerve. At present, the surgery for vestibular schwannoma remains one of the most complicated operations demanding for surgical skills in neurosurgery. And the trend of minimal invasion should also be the major influence on the management of patients with vestibular schwannomas. We summarized the microsurgical removal experience in a recent series of vestibular schwannomas and presented the operative technique and cranial nerve preservation in order to improve the rates of total tumor removal and facial nerve preservation.Methods A retrospective analysis was performed in 145 patients over a 7-year period who suffered from vestibular schwannomas that had been microsurgicaily removed by suboccipital retrosigmoid transmeatus approach with small craniotomy. CT thinner scans revealed the tumor size in the internal auditory meatus and the relationship of the posterior wall of the internal acoustic meatus to the bone labyrinths preoperatively. Brain stem evoked potential was monitored intraoperatively. The posterior wall of the internal acoustic meatus was designedly drilled off. Patient records and operative reports, including data from the electrophysiological monitoring, follow-up audiometric examinations, and neuroradiological findings were analyzed.Results Total tumor resection was achieved in 140 cases (96.6%) and subtotal resection in 5 cases. The anatomical integrity of the facial nerve was preserved in 91.0% (132/145) of the cases. Intracranial end-to-end anastomosis of the facial nerve was performed in 7 cases. Functional preservation of the facial nerve was achieved in 115 patients (Grade Ⅰ and Grade Ⅱ, 79.3%). No patient died in this series. Preservation of nerves and vessels were as important as tumor removal dudng the operation. CT thinner scan could show the relationship between the posterior wall of the internal

  2. Optimal duration of therapy in the recovery period of vestibular diseases

    Directory of Open Access Journals (Sweden)

    M. V. Zamergrad

    2014-01-01

    Full Text Available Dizziness is a common symptom in neurological and general medical practice. In most cases it is caused by diseases of the central or peripheral vestibular system. The most common vestibular system diseases include benign paroxysmal postural vertigo, dizziness, Meniere's disease, vestibular neuronitis, and cerebrovascular diseases. One of the main treatments for the diseases accompanied by dizziness is vestibular rehabilitation that is a complex of exercises, the goal of which is to stimulate vestibular compensation. Adequate vestibular compensation allows a patient to get rid of dizziness and unsteadiness even though vestibular system injury is irreversible. Some medications are able to enhance the efficiency of vestibular rehabilitation. At the same time, the optimal duration of treatment for the most common vestibular disorders has not beenadequately explored. The paper gives the results of an observational program, whose purpose was to determine the optimal duration of vestibular rehabilitation in combination with the use of tanakan in patients with non-progressive unilateral peripheral vestibular disorder.Patients and methods. Data on 46 patients aged 19 to 70 years who underwent vestibular rehabilitation and took tanakan for vertigo caused by vestibular neuronitis (n = 44, labyrinthitis (n =1, or Ramsay Hunt syndrome (n = 1 were analyzed. All the patients were examined four times. The symptoms were recorded and the histories of disease were considered. The degree of vestibular disorders, including vertigo, was assessed when collecting complaints. The symptoms of vertigo were objectivized using its vertigo rating scale and five-point subjective rating scale for vertigo. All the patients underwent standard somatic and neurological examinations and videonystagmography. During the first visit after diagnosis, vestibular exercises were chosen for the patients and tanakan was used in a dose of 40 mg thrice daily to accelerate

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

    Science.gov (United States)

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

    2012-01-01

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

  4. Radiotherapy for Vestibular Schwannomas: A Critical Review

    International Nuclear Information System (INIS)

    Murphy, Erin S.; Suh, John H.

    2011-01-01

    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 to >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.

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

    International Nuclear Information System (INIS)

    Vignaux, G.; Chabbert, C.; Gaboyard-Niay, S.; Travo, C.; Machado, M.L.; Denise, P.; Comoz, F.; Hitier, M.; Landemore, G.; Philoxène, B.; Besnard, S.

    2012-01-01

    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, the 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Vignaux, G. [INSERM, ERI27, Caen, F-14000 (France); Univ Caen, Caen, F-14000 (France); Chabbert, C.; Gaboyard-Niay, S.; Travo, C. [INSERM U1051, Institut des Neurosciences de Montpellier, Montpellier, F-34090,France (France); Machado, M.L. [INSERM, ERI27, Caen, F-14000 (France); Univ Caen, Caen, F-14000 (France); Denise, P. [INSERM, ERI27, Caen, F-14000 (France); Univ Caen, Caen, F-14000 (France); CHRU Caen, Explorations Fonctionnelles, Caen, F-14000 (France); Comoz, F. [CHRU Caen, Laboratoire d' anatomopathologie, Caen, F-14000 (France); Hitier, M. [CHRU Caen, Service d' Otorhinolaryngologie, Caen, F-14000,France (France); Landemore, G. [CHRU Caen, Laboratoire d' anatomopathologie, Caen, F-14000 (France); Philoxène, B. [INSERM, ERI27, Caen, F-14000 (France); Univ Caen, Caen, F-14000 (France); CHRU Caen, Explorations Fonctionnelles, Caen, F-14000 (France); Besnard, S., E-mail: besnard-s@phycog.org [INSERM, ERI27, Caen, F-14000 (France); Univ Caen, Caen, F-14000 (France); CHRU Caen, Explorations Fonctionnelles, Caen, F-14000 (France)

    2012-01-01

    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, the 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.

  7. Presbivértigo: ejercicios vestibulares Presbivertigo: vestibular exercises

    Directory of Open Access Journals (Sweden)

    Esther Bernal Valls

    2006-12-01

    Full Text Available El uso de ejercicios en el tratamiento de pacientes con déficit vestibular crónico está incrementándose de forma notable, lo que evidencia que se trata de un procedimiento que resulta beneficioso para este tipo de pacientes. Los buenos resultados que se obtienen sugieren que los ejercicios vestibulares dan lugar a una estabilidad postural y a una disminución de la sensación de desequilibrio.The use of exercises in the treatment of patients with vestibular deficits is increasing in a representative way, what evidences this is a profitable process for this kind of patients. The good results suggest that vestibular exercises permit a postural stability and a decrease in the perception of disequilibrium.

  8. Evidence of central and peripheral vestibular pathology in blast-related traumatic brain injury.

    Science.gov (United States)

    Scherer, Matthew R; Burrows, Holly; Pinto, Robin; Littlefield, Philip; French, Louis M; Tarbett, Aaron K; Schubert, Michael C

    2011-06-01

    To prospectively assay the vestibular and oculomotor systems of blast-exposed service members with traumatic brain injury (TBI). Prospective, nonblinded, nonrandomized descriptive study. Tertiary care facility (Department of Defense Medical Center). Twenty-four service members recovering from blast-related TBI sustained in Iraq or Afghanistan. Focused history and physical, videonystagmography (VNG), rotational chair, cervical vestibular-evoked myogenic potentials, computerized dynamic posturography, and self-report measures. Vestibular testing confirms a greater incidence of vestibular and oculomotor dysfunction in symptomatic (vestibular-like dizziness) personnel with blast-related TBI relative to asymptomatic group members. VNG in the symptomatic group revealed abnormal nystagmus or oculomotor findings in 6 of 12 subjects tested. Similarly, rotational chair testing in this group revealed evidence of both peripheral (4/12) and central (2/12) vestibular pathology. By contrast, the asymptomatic group revealed less vestibular impairment with 1 of 10 rotational chair abnormalities. The asymptomatic group was further characterized by fewer aberrant nystagmus findings (4/12 abnormal VNGs). Computerized dynamic posturography testing revealed no significant differences between groups. Self-report measures demonstrated differences between groups. Vestibular function testing confirms a greater incidence of peripheral vestibular hypofunction in dizzy service members with blast-related TBI relative to those who are asymptomatic. Additionally, oculomotor abnormalities and/or nystagmus consistent with central involvement were present in 10 of the 24 study participants tested. The precise cause of these findings remains unknown.

  9. Characterization of Cochlear, Vestibular and Cochlear-Vestibular Electrically Evoked Compound Action Potentials in Patients with a Vestibulo-Cochlear Implant

    Directory of Open Access Journals (Sweden)

    T. A. K. Nguyen

    2017-11-01

    Full Text Available The peripheral vestibular system is critical for the execution of activities of daily life as it provides movement and orientation information to motor and sensory systems. Patients with bilateral vestibular hypofunction experience a significant decrease in quality of life and have currently no viable treatment option. Vestibular implants could eventually restore vestibular function. Most vestibular implant prototypes to date are modified cochlear implants to fast-track development. These use various objective measurements, such as the electrically evoked compound action potential (eCAP, to supplement behavioral information. We investigated whether eCAPs could be recorded in patients with a vestibulo-cochlear implant. Specifically, eCAPs were successfully recorded for cochlear and vestibular setups, as well as for mixed cochlear-vestibular setups. Similarities and slight differences were found for the recordings of the three setups. These findings demonstrated the feasibility of eCAP recording with a vestibulo-cochlear implant. They could be used in the short term to reduce current spread and avoid activation of non-targeted neurons. More research is warranted to better understand the neural origin of vestibular eCAPs and to utilize them for clinical applications.

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

    Science.gov (United States)

    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

  11. GABAergic systems in the vestibular nucleus and their contribution to vestibular compensation.

    Science.gov (United States)

    Gliddon, Catherine M; Darlington, Cynthia L; Smith, Paul F

    2005-01-01

    GABA and the GABAA and GABAB receptors play a pivotal role in the coordination of the central vestibular pathways. The commissural inhibition, which exists between the two vestibular nucleus complexes (VNCs) and which is responsible for enhancing the dynamic sensitivity of VNC neurons to head acceleration, is known to be substantially mediated by GABA acting on GABAA and GABAB receptors. After unilateral vestibular deafferentation (UVD), the large asymmetry in spontaneous resting activity between the two VNCs is reinforced and exacerbated by the GABAergic interaction between the ipsilateral and contralateral sides. Although it has been suggested that reduced GABAergic inhibition of the ipsilateral VNC may be partially responsible for the recovery of resting activity that underlies vestibular compensation of the static symptoms of UVD, at present there are few data available to test this hypothesis systematically. There is some evidence that GABA concentrations change in the ipsilateral VNC during the development of compensation; however, it is unclear whether these changes relate to GABA release or to metabolic pools of GABA. Most biochemical studies of GABA receptors have been conducted at the gene expression level. Therefore, it is unclear whether changes in the receptor protein also occur, although the most recent data suggest that changes in GABAA and GABAB receptor density in the VNC are unlikely. The few radioligand binding data relate to GABAA receptors with benzodiazepine binding sites only. A decrease in the sensitivity of ipsilateral VNC neurons from compensated animals to GABA receptor agonists has been reported; however, these studies have employed brainstem slices and therefore the functional identity of the neurons involved has been unclear. Although it seems likely that some changes in central GABAergic systems accompany the recovery of resting activity in the ipsilateral VNC during the development of vestibular compensation, at the present stage

  12. The effects of aging on clinical vestibular evaluations

    Directory of Open Access Journals (Sweden)

    Maxime eMaheu

    2015-09-01

    Full Text Available 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 cVEMP and oVEMP, then the caloric and vHIT methods for semi-circular 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 semi-circular canals function.

  13. Three-dimensional, virtual reality vestibular rehabilitation for chronic imbalance problem caused by Ménière's disease: a pilot study.

    Science.gov (United States)

    Hsu, Su-Yi; Fang, Te-Yung; Yeh, Shih-Ching; Su, Mu-Chun; Wang, Pa-Chun; Wang, Victoria Y

    2017-08-01

    The purpose of this study was to evaluate a three-dimensional, virtual reality system for vestibular rehabilitation in patients with intractable Ménière's disease and chronic vestibular dysfunction. We included 70 patients (36 for study, 34 as control) with a chronic imbalance problem caused by uncompensated Ménière's disease. The virtual reality vestibular rehabilitation comprised four training tasks (modified Cawthorne-Cooksey exercises: eye, head, extension, and coordination exercises) performed in six training sessions (in 4 weeks). Measurements of the task scores and balance parameters obtained at the baseline and after final training sessions were compared. A significant improvement was observed in extension and coordination scores. Patients in the early stages of Ménière's disease had a significantly greater improvement in the center of gravity sway and trajectory excursion in the mediolateral direction than did patients in the late stages of Ménière's disease. Mild functional disability attributable to Ménière's disease was a predictor of improvement in the statokinesigram and maximum trajectory excursion in the anteroposterior direction after rehabilitation. The control group showed no significant improvement in almost all parameters. Virtual reality vestibular rehabilitation may be useful in patients with Ménière's disease, particular those in the early stages or having mild functional disability. Implication for rehabilitation Chronic imbalance caused by uncompensated Ménière's disease is an indication for vestibular rehabilitation. The interactive virtual reality video game, when integrated into vestibular rehabilitation exercise protocol, may assist patients who have mild disability Ménière's disease and who cannot benefit from treatment with drugs or surgery. The initial data from this study support the applicability of three-dimensional virtual reality technology in vestibular rehabilitation programs. The technology gives

  14. [Video-nystagmography and vibration test in the diagnosis of vestibular schwannoma. Review of 100 cases].

    Science.gov (United States)

    Négrevergne, M; Ribeiro, S; Moraes, C L; Maunsell, R; Morata, G Celis; Darrouzet, V

    2003-01-01

    To evaluate informations given by the combination of videonystagmography (VNG) including vibratory tests and auditory brainstem responses (ABR) in patients suffering vestibular schwannoma (VS) and try to find the most conclusive test(s). Combination of different functional tests is supposed to improve diagnosis and preoperative evaluation and precise indication for magnetic resonance imaging (MRI) facing audiological and vestibular symptoms. A prospective study of 100 patients with VS. All patients underwent a preoperative work-up including complete audiometry, auditory brainstem response (ABR) and videonystagmography (VNG). VNG protocol included caloric testing, rotatory tests, oculometry tests (saccade testing, optokinetic testing) and spontaneous and gaze-evoked nystagmus. From these six tests a score of positivity could be set, from 0 to 6. The vibratory test is non invasive and easy to realize. Were observed: 1/ a good sensitivity in vibratory test to elicit nystagmus in this context. 2/ a good correlation between subliminal rotatory chair tests and vibratory tests 3/ a better control of caloric testing using vibratory test. 4/ a good but deficient sensitivity of ABR alone with regard to VS (95%) 5/ an increase of sensitivity of VNG when coupling it with ABR and using as a criterion the score of positivity: no patient had all tests negative. The vibratory test is a non-invasive, fast examination with an easy execution. It reinforces VNG-ABR association screening power to diagnose VS. It constitutes, combined to caloric testing a good tool to diagnose and evaluate unilateral vestibular weakness.

  15. Vestibular findings in fibromyalgia patients

    Directory of Open Access Journals (Sweden)

    Zeigelboim, Bianca Simone

    2011-07-01

    Full Text Available Introduction: Fibromyalgia (FM is a non-inflammatory musculoskeletal chronic syndrome, whose etiology is unknown, characterized by a diffuse pain, increase in palpation sensitivity and such symptoms as tiredness, insomnia, anxiety, depression, cold intolerance and otologic complaints. Objective: Evaluate the vestibular behavior in fibromyalgia patients. Method: A retrospective transversal study was performed. 25 patients aged between 26 and 65 (average age - 52.2 and standard deviation - 10.3 were evaluated and submitted to the following procedures: anamnesis, otorhinolaryngologic and vestibular evaluation by way of vector electronystamography. Results: a The most evident otoneurologic symptoms were: difficulty or pain when moving the neck and pain was spread to an arm or shoulder (92.0% in each, dizziness (84.0% and headache (76.0%. The different clinical symptoms mostly reported were: depression (80.0%, anxiety (76.0% and insomnia (72.0%; b vestibular examination showed an alteration in 12 patients (48.0% in the caloric test; c an alteration in the peripheral vestibular system prevailed, and d deficient peripheral vestibular disorders were prevalent. Conclusion: This study enabled the importance of the labyrinthic test to be verified, thus emphasizing that this kind of people must be studied better, since a range of rheumatologic diseases can cause severe vestibular changes as a result of their manifestations and impairment areas.

  16. Atypical Manifestation of Vestibular Schwannoma

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    Webster, Guilherme

    2013-09-01

    Full Text Available Introduction: Vestibular schwannoma (also known as acoustic neuroma is a benign tumor whose cells are derived from Schwann sheaths, which commonly occurs from the vestibular portion of the eighth cranial nerve. Furthermore, vestibular schwannomas account for ∼8% of intracranial tumors in adults and 80 to 90% of tumors of the cerebellopontine angle. Its symptoms are varied, but what stands out most is a unilateral sensorineural hearing loss, with a low index of speech recognition. Objective: Describe an atypical manifestation of vestibular schwannoma. Case Report: The 46-year-old woman had vertigo and binaural hearing loss and fullness, with ear, nose, and throat examination suggestive of cochlear injury. After 6 months, the patient developed worsening of symptoms and onset of right unilateral tinnitus. In further exams the signs of cochlear damage remained, except for the vestibular test (hyporeflexia. Magnetic resonance imaging showed an expansive lesion in the right cerebellopontine angle. Discussion: This report warns about the atypical manifestations of vestibular schwannoma, which must always be remembered in investigating and diagnosing hearing loss.

  17. Vestibular hearing and neural synchronization.

    Science.gov (United States)

    Emami, Seyede Faranak; Daneshi, Ahmad

    2012-01-01

    Objectives. Vestibular hearing as an auditory sensitivity of the saccule in the human ear is revealed by cervical vestibular evoked myogenic potentials (cVEMPs). The range of the vestibular hearing lies in the low frequency. Also, the amplitude of an auditory brainstem response component depends on the amount of synchronized neural activity, and the auditory nerve fibers' responses have the best synchronization with the low frequency. Thus, the aim of this study was to investigate correlation between vestibular hearing using cVEMPs and neural synchronization via slow wave Auditory Brainstem Responses (sABR). Study Design. This case-control survey was consisted of twenty-two dizzy patients, compared to twenty healthy controls. Methods. Intervention comprised of Pure Tone Audiometry (PTA), Impedance acoustic metry (IA), Videonystagmography (VNG), fast wave ABR (fABR), sABR, and cVEMPs. Results. The affected ears of the dizzy patients had the abnormal findings of cVEMPs (insecure vestibular hearing) and the abnormal findings of sABR (decreased neural synchronization). Comparison of the cVEMPs at affected ears versus unaffected ears and the normal persons revealed significant differences (P < 0.05). Conclusion. Safe vestibular hearing was effective in the improvement of the neural synchronization.

  18. Vestibular Dysfunction in Wernicke’s Encephalopathy: Predominant Impairment of the Horizontal Semicircular Canals

    Directory of Open Access Journals (Sweden)

    Seung-Han Lee

    2018-03-01

    Full Text Available BackgroundWernicke’s encephalopathy (WE, a metabolic disorder due to thiamine deficiency, manifests with various neurological symptoms and signs. It has been known as a cause of vestibular dysfunction. Preliminary reports have proposed predominant involvement of the horizontal semicircular canals (HSCs.ObjectiveTo better characterize the pattern of vestibular impairment in patients with WE using quantitative video head-impulse testing and to review the literature regarding this topic.MethodFrom January 2014 to December 2016, we retrospectively enrolled five cases of WE that received quantitative video-head-impulse testing (vHIT. We retrieved the clinical features from the medical records and reviewed quantitative head-impulse testing (qHIT and caloric irrigation. Based on the gain and the number of corrective saccades, the function (normal vs. impaired of each semicircular canal was rated. In addition, we conducted a MEDLINE and EMBASE search to identify other published cases of WE that had received qHIT. Neuro-otologic and neuro-ophthalmologic findings and vestibular testing results were extracted.ResultsA total of 17 patients (own series = 5; published cases = 12 aged 54.6 ± 11 years were included. Key neurologic findings were ataxia of stance and gait (13/13, 100%, spontaneous nystagmus (7/14, 50%, gaze-evoked nystagmus (GEN (17/17, 100%, positive bedside head-impulse testing for the horizontal canals (16/17, 94%, and memory impairment and mental changes (6/11, 54.5%. Regarding vestibular testing, qHIT (either video based or search-coil based documented selective bilateral horizontal canal dysfunction with normal or minimal vertical canal impairment (14/14, 100%. On caloric irrigation, bilateral horizontal canal paresis was noted in most cases (10/11, 91%.ConclusionIn WE, signs of both peripheral and central vestibular dysfunction (i.e., GEN, ataxia of stance and gait, abnormal head-impulse testing were common. Selective or

  19. Electrophysiological Measurements of Peripheral Vestibular Function—A Review of Electrovestibulography

    Directory of Open Access Journals (Sweden)

    Daniel J. Brown

    2017-05-01

    Full Text Available Electrocochleography (EcochG, incorporating the Cochlear Microphonic (CM, the Summating Potential (SP, and the cochlear Compound Action Potential (CAP, has been used to study cochlear function in humans and experimental animals since the 1930s, providing a simple objective tool to assess both hair cell (HC and nerve sensitivity. The vestibular equivalent of ECochG, termed here Electrovestibulography (EVestG, incorporates responses of the vestibular HCs and nerve. Few research groups have utilized EVestG to study vestibular function. Arguably, this is because stimulating the cochlea in isolation with sound is a trivial matter, whereas stimulating the vestibular system in isolation requires significantly more technical effort. That is, the vestibular system is sensitive to both high-level sound and bone-conducted vibrations, but so is the cochlea, and gross electrical responses of the inner ear to such stimuli can be difficult to interpret. Fortunately, several simple techniques can be employed to isolate vestibular electrical responses. Here, we review the literature underpinning gross vestibular nerve and HC responses, and we discuss the nomenclature used in this field. We also discuss techniques for recording EVestG in experimental animals and humans and highlight how EVestG is furthering our understanding of the vestibular system.

  20. Vestibular brain changes within 70 days of head down bed rest.

    Science.gov (United States)

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

    2018-03-12

    Head-down-tilt bed rest (HDBR) is frequently utilized as a spaceflight analog research environment to study the effects of axial body unloading and fluid shifts that are associated with spaceflight in the absence of gravitational modifications. HDBR has been shown to result in balance changes, presumably due to sensory reweighting and adaptation processes. Here, we examined whether HDBR results in changes in the neural correlates of vestibular processing. Thirteen men participated in a 70-day HDBR intervention; we measured balance, functional mobility, and functional brain activity in response to vestibular stimulation at 7 time points before, during, and after HDBR. Vestibular stimulation was administered by means of skull taps, resulting in activation of the vestibular cortex and deactivation of the cerebellar, motor, and somatosensory cortices. Activation in the bilateral insular cortex, part of the vestibular network, gradually increased across the course of HDBR, suggesting an upregulation of vestibular inputs in response to the reduced somatosensory inputs experienced during bed rest. Furthermore, greater increase of activation in multiple frontal, parietal, and occipital regions in response to vestibular stimulation during HDBR was associated with greater decrements in balance and mobility from before to after HDBR, suggesting reduced neural efficiency. These findings shed light on neuroplastic changes occurring with conditions of altered sensory inputs, and reveal the potential for central vestibular-somatosensory convergence and reweighting with bed rest. © 2018 Wiley Periodicals, Inc.

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

    Science.gov (United States)

    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.

  2. Plasticity during vestibular compensation: the role of saccades

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    Hamish Gavin MacDougall

    2012-02-01

    Full Text Available This paper is focussed on one major aspect of compensation: the recent behavioural findings concerning oculomotor responses in human vestibular compensation and their possible implications for recovery after unilateral vestibular loss (UVL. New measurement techniques have provided new insights into how patients recover after UVL and have given clues for vestibular rehabilitation. Prior to this it has not been possible to quantify the level of function of all the peripheral vestibular sense organs. Now it is. By using vestibular-evoked myogenic potentials to measure utricular and saccular function and by new video head impulse testing to measure semicircular canal function to natural values of head accelerations. With these new video procedures it is now possible to measure both slow phase eye velocity and also saccades during natural head movements. The present evidence is that there is little or no recovery of slow phase eye velocity responses to natural head accelerations. It is doubtful as to whether the modest changes in slow phase eye velocity to small angular accelerations are functionally effective during compensation. On the other hand it is now clear that saccades can play a very important role in helping patients compensate and return to a normal lifestyle. Preliminary evidence suggests that different patterns of saccadic response may predict how well patients recover. It may be possible to train patients to produce more effective saccadic patterns in the first days after their unilateral loss. Some patients do learn new strategies, new behaviours, to conceal their inadequate VOR but when those strategies are prevented from operating by using passive, unpredictable, high acceleration natural head movements, as in the head impulse test, their vestibular loss can be demonstrated. It is those very strategies which the tests exclude, which may be the cause of their successful compensation.

  3. Otolith-Canal Convergence In Vestibular Nuclei Neurons

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  5. Treatment of peripheral vestibular dysfunction using photobiomodulation

    Science.gov (United States)

    Lee, Min Young; Hyun, Jai-Hwan; Suh, Myung-Whan; Ahn, Jin-Chul; Chung, Phil-Sang; Jung, Jae Yun; Rhee, Chung Ku

    2017-08-01

    Gentamicin, which is still used in modern medicine, is a known vestibular toxic agent, and various degrees of balance problems have been observed after exposure to this pharmacologic agent. Photobiomodulation is a candidate therapy for vertigo due to its ability to reach deep inner ear organs such as the cochlea. Previous reports have suggested that photobiomodulation can improve hearing and cochlea function. However, few studies have examined the effect of photobiomodulation on balance dysfunction. We used a rat model to mimic human vestibulopathy resulting from gentamicin treatment and evaluated the effect of photobiomodulation on vestibular toxicity. Slow harmonic acceleration (SHA) rotating platform testing was used for functional evaluation and both qualitative and quantitative epifluorescence analyses of cupula histopathology were performed. Animals were divided into gentamicin only and gentamicin plus laser treatment groups. Laser treatment was applied to one ear, and function and histopathology were evaluated in both ears. Decreased function was observed in both ears after gentamicin treatment, demonstrated by low gain and no SHA asymmetry. Laser treatment minimized the damage resulting from gentamicin treatment as shown by SHA asymmetry and recovered gain in the treated ear. Histology results reflected the functional results, showing increased hair cell density and epifluorescence intensity in laser-treated cupulae.

  6. Allicin protects against cisplatin-induced vestibular dysfunction by inhibiting the apoptotic pathway.

    Science.gov (United States)

    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.

  7. 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

    Directory of Open Access Journals (Sweden)

    Kikuro eFukushima

    2011-12-01

    Full Text Available 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 cancelling 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

  8. Vestibular myogenic and acoustical brainstem evoked potentials in neurological practice

    Directory of Open Access Journals (Sweden)

    O. S. Korepina

    2012-01-01

    Full Text Available Along with the inspection of acoustical cortex and brainstem EP in neurologic, otoneurologic and audiologic practice recently start to use so-called vestibular evoked myogenic potentials (VEMP. It is shown, that at ear stimulation by a loud sound and record of sterno-cleidomastoid contraction is possible to estimate function of the inferior vestibular nerve and vestibulospinal pathways, a sacculo-cervical reflex. In article some methodical and clinical questions of application of these kinds are presented. Combine research acoustic brainstem EP and VEMP allows to confirm effectively lesions of acoustical and vestibular ways at brainstem. The conclusion becomes, that this kind of inspection is important for revealing demielinisation and defeats in vestibulospinal tract, that quite often happens at MS, and at estimation of efficiency of treatment

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

    Science.gov (United States)

    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

  10. Dizziness and Imbalance in the Elderly: Age-related Decline in the Vestibular System

    Science.gov (United States)

    Iwasaki, Shinichi; Yamasoba, Tatsuya

    2015-01-01

    Dizziness and imbalance are amongst the most common complaints in older people, and are a growing public health concern since they put older people at a significantly higher risk of falling. Although the causes of dizziness in older people are multifactorial, peripheral vestibular dysfunction is one of the most frequent causes. Benign paroxysmal positional vertigo is the most frequent form of vestibular dysfunction in the elderly, followed by Meniere’s disease. Every factor associated with the maintenance of postural stability deteriorates during aging. Age-related deterioration of peripheral vestibular function has been demonstrated through quantitative measurements of the vestibulo-ocular reflex with rotational testing and of the vestibulo-collic reflex with testing of vestibular evoked myogenic potentials. Age-related decline of vestibular function has been shown to correlate with the age-related decrease in the number of vestibular hair cells and neurons. The mechanism of age-related cellular loss in the vestibular endorgan is unclear, but it is thought that genetic predisposition and cumulative effect of oxidative stress may both play an important role. Since the causes of dizziness in older people are multi-factorial, management of this disease should be customized according to the etiologies of each individual. Vestibular rehabilitation is found to be effective in treating both unilateral and bilateral vestibular dysfunction. Various prosthetic devices have also been developed to improve postural balance in older people. Although there have been no medical treatments improving age-related vestibular dysfunction, new medical treatments such as mitochondrial antioxidants or caloric restriction, which have been effective in preventing age-related hearing loss, should be ienvestigated in the future. PMID:25657851

  11. Distinct roles of Eps8 in the maturation of cochlear and vestibular hair cells.

    Science.gov (United States)

    Tavazzani, Elisa; Spaiardi, Paolo; Zampini, Valeria; Contini, Donatella; Manca, Marco; Russo, Giancarlo; Prigioni, Ivo; Marcotti, Walter; Masetto, Sergio

    2016-07-22

    Several genetic mutations affecting the development and function of mammalian hair cells have been shown to cause deafness but not vestibular defects, most likely because vestibular deficits are sometimes centrally compensated. The study of hair cell physiology is thus a powerful direct approach to ascertain the functional status of the vestibular end organs. Deletion of Epidermal growth factor receptor pathway substrate 8 (Eps8), a gene involved in actin remodeling, has been shown to cause deafness in mice. While both inner and outer hair cells from Eps8 knockout (KO) mice showed abnormally short stereocilia, inner hair cells (IHCs) also failed to acquire mature-type ion channels. Despite the fact that Eps8 is also expressed in vestibular hair cells, Eps8 KO mice show no vestibular deficits. In the present study we have investigated the properties of vestibular Type I and Type II hair cells in Eps8-KO mice and compared them to those of cochlear IHCs. In the absence of Eps8, vestibular hair cells show normally long kinocilia, significantly shorter stereocilia and a normal pattern of basolateral voltage-dependent ion channels. We have also found that while vestibular hair cells from Eps8 KO mice show normal voltage responses to injected sinusoidal currents, which were used to mimic the mechanoelectrical transducer current, IHCs lose their ability to synchronize their responses to the stimulus. We conclude that the absence of Eps8 produces a weaker phenotype in vestibular hair cells compared to cochlear IHCs, since it affects the hair bundle morphology but not the basolateral membrane currents. This difference is likely to explain the absence of obvious vestibular dysfunction in Eps8 KO mice. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

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

    DEFF Research Database (Denmark)

    Schüz, Joachim; Steding-Jessen, Marianne; Hansen, Søren

    2011-01-01

    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...... 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...

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

    DEFF Research Database (Denmark)

    Schüz, Joachim; Steding-Jessen, Marianne; Hansen, Søren

    2011-01-01

    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...... 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...

  17. Intermediate Latency-Evoked Potentials of Multimodal Cortical Vestibular Areas: Galvanic Stimulation

    Directory of Open Access Journals (Sweden)

    Stefan Kammermeier

    2017-11-01

    Full Text Available IntroductionHuman multimodal vestibular cortical regions are bilaterally anterior insulae and posterior opercula, where characteristic vestibular-related cortical potentials were previously reported under acoustic otolith stimulation. Galvanic vestibular stimulation likely influences semicircular canals preferentially. Galvanic stimulation was compared to previously established data under acoustic stimulation.Methods14 healthy right-handed subjects, who were also included in the previous acoustic potential study, showed normal acoustic and galvanic vestibular-evoked myogenic potentials. They received 2,000 galvanic binaural bipolar stimuli for each side during EEG recording.ResultsVestibular cortical potentials were found in all 14 subjects and in the pooled data of all subjects (“grand average” bilaterally. Anterior insula and posterior operculum were activated exclusively under galvanic stimulation at 25, 35, 50, and 80 ms; frontal regions at 30 and 45 ms. Potentials at 70 ms in frontal regions and at 110 ms at all of the involved regions could also be recorded; these events were also found using acoustic stimulation in our previous study.ConclusionGalvanic semicircular canal stimulation evokes specific potentials in addition to those also found with acoustic otolith stimulation in identically located regions of the vestibular cortex. Vestibular cortical regions activate differently by galvanic and acoustic input at the peripheral sensory level.SignificanceDifferential effects in vestibular cortical-evoked potentials may see clinical use in specific vertigo disorders.

  18. Reduced systemic toxicity and preserved vestibular toxicity following co-treatment with nitriles and CYP2E1 inhibitors: a mouse model for hair cell loss.

    Science.gov (United States)

    Saldaña-Ruíz, Sandra; Boadas-Vaello, Pere; Sedó-Cabezón, Lara; Llorens, Jordi

    2013-10-01

    Several nitriles, including allylnitrile and cis-crotononitrile, have been shown to be ototoxic and cause hair cell degeneration in the auditory and vestibular sensory epithelia of mice. However, these nitriles can also be lethal due in large part to the microsomal metabolic release of cyanide, which is mostly dependent on the activity of the 2E1 isoform of the cytochrome P450 (CYP2E1). In this study, we co-administered mice with a nitrile and, to reduce their lethal effects, a selective CYP2E1 inhibitor: diallylsulfide (DAS) or trans-1,2-dichloroethylene (TDCE). Both in female 129S1/SvImJ (129S1) mice co-treated with DAS and cis-crotononitrile and in male RjOrl:Swiss/CD-1 (Swiss) mice co-treated with TDCE and allylnitrile, the nitrile caused a dose-dependent loss of vestibular function, as assessed by a specific behavioral test battery, and of hair cells, as assessed by hair bundle counts using scanning electron microscopy. In the experiments, the CYP2E1 inhibitors provided significant protection against the lethal effects of the nitriles and did not diminish the vestibular toxicity as assessed by behavioral effects in comparison to animals receiving no inhibitor. Additional experiments using a single dose of allylnitrile demonstrated that TDCE does not cause hair cell loss on its own and does not modify the vestibular toxicity of the nitrile in either male or female 129S1 mice. In all the experiments, high vestibular dysfunction scores in the behavioral test battery predicted extensive to complete loss of hair cells in the utricles. This provides a means of selecting animals for subsequent studies of vestibular hair cell regeneration or replacement.

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

    Science.gov (United States)

    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.

  20. Migraine patients consistently show abnormal vestibular bedside tests

    Directory of Open Access Journals (Sweden)

    Eliana Teixeira Maranhão

    2015-01-01

    Full Text Available 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.Objective 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.Method Cross-sectional study including sixty individuals – thirty migraineurs, 25 women, 19-60 y-o; and 30 gender/age healthy paired controls.Results 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.Conclusion Migraine patients consistently showed abnormal vestibular bedside tests when compared with controls.

  1. Migraine patients consistently show abnormal vestibular bedside tests.

    Science.gov (United States)

    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.

  2. Vestibular migraine: who is the patient?

    Science.gov (United States)

    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.

  3. Neuroticism modulates brain visuo-vestibular and anxiety systems during a virtual rollercoaster task.

    Science.gov (United States)

    Riccelli, Roberta; Indovina, Iole; Staab, Jeffrey P; Nigro, Salvatore; Augimeri, Antonio; Lacquaniti, Francesco; Passamonti, Luca

    2017-02-01

    Different lines of research suggest that anxiety-related personality traits may influence the visual and vestibular control of balance, although the brain mechanisms underlying this effect remain unclear. To our knowledge, this is the first functional magnetic resonance imaging (fMRI) study that investigates how individual differences in neuroticism and introversion, two key personality traits linked to anxiety, modulate brain regional responses and functional connectivity patterns during a fMRI task simulating self-motion. Twenty-four healthy individuals with variable levels of neuroticism and introversion underwent fMRI while performing a virtual reality rollercoaster task that included two main types of trials: (1) trials simulating downward or upward self-motion (vertical motion), and (2) trials simulating self-motion in horizontal planes (horizontal motion). Regional brain activity and functional connectivity patterns when comparing vertical versus horizontal motion trials were correlated with personality traits of the Five Factor Model (i.e., neuroticism, extraversion-introversion, openness, agreeableness, and conscientiousness). When comparing vertical to horizontal motion trials, we found a positive correlation between neuroticism scores and regional activity in the left parieto-insular vestibular cortex (PIVC). For the same contrast, increased functional connectivity between the left PIVC and right amygdala was also detected as a function of higher neuroticism scores. Together, these findings provide new evidence that individual differences in personality traits linked to anxiety are significantly associated with changes in the activity and functional connectivity patterns within visuo-vestibular and anxiety-related systems during simulated vertical self-motion. Hum Brain Mapp 38:715-726, 2017. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

  4. Linear accelerator-based stereotactic radiosurgery for bilateral vestibular schwannomas in patients with neurofibromatosis type 2

    NARCIS (Netherlands)

    Meijer, Otto W. M.; Vandertop, W. Peter; Lagerwaard, Frank J.; Slotman, Ben J.

    2008-01-01

    OBJECTIVE: Patients with neurofibromatosis Type 2 (NF2) patients typically have bilateral vestibular schwannomas (VS) and are at risk for developing bilateral deafness, bilateral trigeminal, and bilateral facial nerve function loss. Previous reports suggested that treatment outcomes in these

  5. Towards a neuromorphic vestibular system.

    Science.gov (United States)

    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.

  6. Perspectival Structure and Vestibular Processing

    DEFF Research Database (Denmark)

    Alsmith, Adrian John Tetteh

    2016-01-01

    I begin by contrasting a taxonomic approach to the vestibular system with the structural approach I take in the bulk of this commentary. I provide an analysis of perspectival structure. Employing that analysis and following the structural approach, I propose three lines of empirical investigation...

  7. Vestibular evoked myogenic potentials: an overview Potencial evocado miogênico vestibular: uma visão geral

    Directory of Open Access Journals (Sweden)

    Renato Cal

    2009-06-01

    Full Text Available The vestibular evoked myogenic potential (VEMP test is a relatively new diagnostic tool that is in the process of being investigated in patients with specific vestibular disorders. Briefly, the VEMP is a biphasic response elicited by loud clicks or tone bursts recorded from the tonically contracted sternocleidomastoid muscle, being the only resource available to assess the function of the saccule and the lower portion of the vestibular nerve. AIM: In this review, we shall highlight the history, methods, current VEMP status, and discuss its specific application in the diagnosis of the Ménière's Syndrome.O teste do potencial evocado miogênico vestibular (PEMV é um instrumento diagnóstico relativamente novo e ainda em processo de validação em estudos com pacientes portadores de desordens vestibulares específicas. De forma resumida, o PEMV é uma resposta bifásica em resposta a estímulos sonoros gravados a partir de contrações do músculo esternocleidomastóideo e é o único recurso existente para avaliar a função do sáculo e da divisão inferior do nervo vestibular. OBJETIVO: Nesta revisão iremos destacar a história, método de realização, situação atual da pesquisa envolvendo o PEMV, além de discutir as suas aplicações específicas no diagnóstico da síndrome de Ménière.

  8. Spatio-temporal pattern of vestibular information processing after brief caloric stimulation

    International Nuclear Information System (INIS)

    Marcelli, Vincenzo; Esposito, Fabrizio; Aragri, Adriana; Furia, Teresa; Riccardi, Pasquale; Tosetti, Michela; Biagi, Laura; Marciano, Elio; Di Salle, Francesco

    2009-01-01

    Processing of vestibular information at the cortical and subcortical level is essential for head and body orientation in space and self-motion perception, but little is known about the neural dynamics of the brain regions of the vestibular system involved in this task. Neuroimaging studies using both galvanic and caloric stimulation have shown that several distinct cortical and subcortical structures can be activated during vestibular information processing. The insular cortex has been often targeted and presented as the central hub of the vestibular cortical system. Since very short pulses of cold water ear irrigation can generate a strong and prolonged vestibular response and a nystagmus, we explored the effects of this type of caloric stimulation for assessing the blood-oxygen-level-dependent (BOLD) dynamics of neural vestibular processing in a whole-brain event-related functional magnetic resonance imaging (fMRI) experiment. We evaluated the spatial layout and the temporal dynamics of the activated cortical and subcortical regions in time-locking with the instant of injection and were able to extract a robust pattern of neural activity involving the contra-lateral insular cortex, the thalamus, the brainstem and the cerebellum. No significant correlation with the temporal envelope of the nystagmus was found. The temporal analysis of the activation profiles highlighted a significantly longer duration of the evoked BOLD activity in the brainstem compared to the insular cortex suggesting a functional de-coupling between cortical and subcortical activity during the vestibular response.

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

    Science.gov (United States)

    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

  10. Motor performance is impaired following vestibular stimulation in ageing mice.

    Directory of Open Access Journals (Sweden)

    Victoria W.K. Tung

    2016-02-01

    Full Text Available 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 behavioural 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 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, behavioural changes in task performance were observed.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  13. Outcome after translabyrinthine surgery for vestibular schwannomas

    DEFF Research Database (Denmark)

    Springborg, Jacob Bertram; Fugleholm, Kåre; Poulsgaard, Lars

    2012-01-01

    The objective of this article is to study the outcome after translabyrinthine surgery for vestibular schwannomas, with special focus on the facial nerve function. The study design is a case series from a national centralized database and it is set in two University Hospitals in Denmark....... Participants were 1244 patients who underwent translabyrinthine surgery during a period of 33 years from 1976 to 2009. Main outcome measures were tumor removal, intraoperative facial nerve preservation, complications, and postoperative facial nerve function. In 84% patients, the tumor was totally resected...... and in ~85% the nerve was intact during surgery. During 33 years, 12 patients died from complications to surgery and ~14% had cerebrospinal fluid leakage. Before surgery, 74 patients had facial paresis and 46% of these improved after surgery. In patients with normal facial function, overall ~70% had a good...

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

    Science.gov (United States)

    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.

  15. Achados vestibulares em usuários de aparelho de amplificação sonora individual Vestibular findings in hearing aid users

    Directory of Open Access Journals (Sweden)

    Fabiane Paulin

    2009-01-01

    patients, 18 (90% showed tinnitus complaint, 15 (75% dizziness complaint and eight (40% headache complaint; b There was a prevalence of alterations in the caloric test and in the peripheral vestibular system; c the results of the vestibular exam showed alterations in 14 patients (70% being, eight cases (40% of peripheral vestibular irritative syndromes and six cases (30% of peripheral vestibular deficiency syndromes; d we verified significant difference between the vestibular exam results and how long the patient had use the hearing aid; e from the five patients that did not related vestibular symptoms four (80% showed alterations in the vestibular exam. CONCLUSION: the importance and sensibility of the functional study regarding the balance system in this type of population must be emphasized because same disorders may occur in the vestibular exam in spite of symptom presence.

  16. Direct fragmentation of quarkonia including Fermi motion using light-cone wave function

    Energy Technology Data Exchange (ETDEWEB)

    Nobary, M.A. Gomshi [Razi University, Department of Physics, Faculty of Science, Kermanshah (Iran); A.E.O.I., Center for Theoretical Physics and Mathematics, Tehran (Iran); Javadi, B. [Razi University, Department of Physics, Faculty of Science, Kermanshah (Iran)

    2005-07-01

    We investigate the effect of Fermi motion on the direct fragmentation of the J/{psi} and {upsilon} states employing a light-cone wave function. Consistent with such a wave function we set up the kinematics of a heavy quark fragmenting into quarkonia such that the Fermi motion of the constituents splits into a longitudinal as well as a transverse direction and thus calculate the fragmentation functions for these states. In the framework of our investigation, we estimate that the fragmentation probabilities of J/{psi} and {upsilon} may increase at least up to 14 percent when including this degree of freedom. (orig.)

  17. Galvanic vestibular stimulation speeds visual memory recall.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  19. Integration of Visual and Vestibular Information Used to Discriminate Rotational Self-Motion

    Directory of Open Access Journals (Sweden)

    Florian Soyka

    2011-10-01

    Full Text Available Do humans integrate visual and vestibular information in a statistically optimal fashion when discriminating rotational self-motion stimuli? Recent studies are inconclusive as to whether such integration occurs when discriminating heading direction. In the present study eight participants were consecutively rotated twice (2s sinusoidal acceleration on a chair about an earth-vertical axis in vestibular-only, visual-only and visual-vestibular trials. The visual stimulus was a video of a moving stripe pattern, synchronized with the inertial motion. Peak acceleration of the reference stimulus was varied and participants reported which rotation was perceived as faster. Just-noticeable differences (JND were estimated by fitting psychometric functions. The visual-vestibular JND measurements are too high compared to the predictions based on the unimodal JND estimates and there is no JND reduction between visual-vestibular and visual-alone estimates. These findings may be explained by visual capture. Alternatively, the visual precision may not be equal between visual-vestibular and visual-alone conditions, since it has been shown that visual motion sensitivity is reduced during inertial self-motion. Therefore, measuring visual-alone JNDs with an underlying uncorrelated inertial motion might yield higher visual-alone JNDs compared to the stationary measurement. Theoretical calculations show that higher visual-alone JNDs would result in predictions consistent with the JND measurements for the visual-vestibular condition.

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

    Directory of Open Access Journals (Sweden)

    Terry D. Fife

    2018-05-01

    Full Text Available 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.

  1. Molecular composition of extracellular matrix in the vestibular nuclei of the rat.

    Science.gov (United States)

    Rácz, Eva; Gaál, Botond; Kecskes, Szilvia; Matesz, Clara

    2014-07-01

    Previous studies have demonstrated that the molecular and structural composition of the extracellular matrix (ECM) shows regional differences in the central nervous system. By using histochemical and immunohistochemical methods, we provide here a detailed map of the distribution of ECM molecules in the vestibular nuclear complex (VNC) of the rat. We have observed common characteristics of the ECM staining pattern in the VNC and a number of differences among the individual vestibular nuclei and their subdivisions. The perineuronal net (PNN), which is the pericellular condensation of ECM, showed the most intense staining for hyaluronan, aggrecan, brevican and tenascin-R in the superior, lateral and medial vestibular nuclei, whereas the HAPLN1 link protein and the neurocan exhibited moderate staining intensity. The rostral part of the descending vestibular nucleus (DVN) presented a similar staining pattern in the PNN, with the exception of brevican, which was negative. The caudal part of the DVN had the weakest staining for all ECM molecules in the PNN. Throughout the VNC, versican staining in the PNN, when present, was distinctive due to its punctuate appearance. The neuropil also exhibited heterogeneity among the individual vestibular nuclei in ECM staining pattern and intensity. We find that the heterogeneous distribution of ECM molecules is associated in many cases with the variable cytoarchitecture and hodological organization of the vestibular nuclei, and propose that differences in the ECM composition may be related to specific neuronal functions associated with gaze and posture control and vestibular compensation.

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

    Science.gov (United States)

    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

  3. Predictors of vertigo in patients with untreated vestibular schwannoma.

    Science.gov (United States)

    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.

  4. Bilateral Vestibular Deficiency: Quality of Life and Economic Implications.

    Science.gov (United States)

    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 work days (P life and imposes substantial economic burdens on individuals and society. These results underscore the limits of adaptation and compensation in BVD. Furthermore, they quantify the potential benefits of prosthetic restoration of vestibular function both to these individuals and to society.

  5. Normalization reduces intersubject variability in cervical vestibular evoked myogenic potentials.

    Science.gov (United States)

    van Tilburg, Mark J; Herrmann, Barbara S; Guinan, John J; Rauch, Steven D

    2014-09-01

    Cervical vestibular evoked myogenic potentials are used to assess saccular and inferior vestibular nerve function. Normalization of the VEMP waveform has been proposed to reduce the variability in vestibular evoked myogenic potentials by correcting for muscle activation. In this study, we test the hypothesis that normalization of the raw cervical VEMP waveform causes a significant decrease in the intersubject variability. Prospective cohort study. Large specialty hospital, department of otolaryngology. Twenty healthy subjects were used in this study. All subjects underwent cervical vestibular evoked myogenic potential testing using short tone bursts at 250, 500, 750, and 1,000 Hz. Both intersubject and intrasubject variability was assessed. Variability between raw and normalized peak-to-peak amplitudes was compared using the coefficient of variation. Intrasubject variability was assessed using the intraclass correlation coefficient and interaural asymmetry ratio. cVEMPs were present in most ears. Highest peak-to-peak amplitudes were recorded at 750 Hz. Normalization did not alter cVEMP tuning characteristics. Normalization of the cVEMP response caused a significant reduction in intersubject variability of the peak-to-peak amplitude. No significant change was seen in the intrasubject variability. Normalization significantly reduces cVEMP intersubject variability in healthy subjects without altering cVEMP characteristics. By reducing cVEMP amplitude variation due to nonsaccular, muscle-related factors, cVEMP normalization is expected to improve the ability to distinguish between healthy and pathologic responses in the clinical application of cVEMP testing.

  6. Imaging-documented repeated intratumoral hemorrhage in vestibular schwannoma: a case report

    NARCIS (Netherlands)

    Mandl, E. S.; Vandertop, W. P.; Meijer, O. W. M.; Peerdeman, S. M.

    2009-01-01

    Intratumoral hemorrhage in vestibular schwannomas is rare. Symptoms often have an acute onset and include headache, nausea, vomiting, vertigo, and depressed consciousness. Intratumoral hemorrhage is probably caused by vascular fragility associated with tumor characteristics and growth. With

  7. Prediction of Balance Compensation After Vestibular Schwannoma Surgery.

    Science.gov (United States)

    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.

  8. A study on vestibular-evoked myogenic potentials via galvanic vestibular stimulation in normal people

    Directory of Open Access Journals (Sweden)

    Ying Cheng

    2018-03-01

    Discussions: Galvanic vestibular stimulation could elicit biphasic EMG responses from SCM via the vestibular nerve but not from the otolith organs. Galvanic stimulation together with air conducted sound (ACS or bone conducted vibration (BCV can elicit VEMPs and may enable the differentiation of retrolabyrinthine lesions from labyrinthine lesions in vestibular system.

  9. Association between functional performance and executive cognitive functions in an elderly population including patients with low ankle–brachial index

    Science.gov (United States)

    Ferreira, Naomi Vidal; Cunha, Paulo Jannuzzi; da Costa, Danielle Irigoyen; dos Santos, Fernando; Costa, Fernando Oliveira; Consolim-Colombo, Fernanda; Irigoyen, Maria Cláudia

    2015-01-01

    Introduction Peripheral arterial disease, as measured by the ankle–brachial index (ABI), is prevalent among the elderly, and is associated with functional performance, assessed by the 6-minute walk test (6MWT). Executive cognitive function (ECF) impairments are also prevalent in this population, but no existing study has investigated the association between ECF and functional performance in an elderly population including individuals with low ABI. Aim To investigate the association between functional performance, as measured by the 6MWT, and loss in ECF, in an elderly sample including individuals with low ABI. Method The ABI group was formed by 26 elderly individuals with low ABI (mean ABI: 0.63±0.19), and the control group was formed by 40 elderly individuals with normal ABI (mean ABI: 1.08±0.07). We analyzed functional performance using the 6MWT, global cognition using the Mini-Mental State Examination (MMSE), and ECF using the Digit Span for assessing attention span and working memory, the Stroop Color Word Test (SCWT) for assessing information processing speed and inhibitory control/impulsivity, and the Controlled Oral Word Association Test (COWAT) for assessing semantic verbal fluency and phonemic verbal fluency. We also used a factor analysis on all of the ECF tests (global ECF). Results Before adjustment, the ABI group performed worse on global cognition, attention span, working memory, inhibitory control/impulsivity, semantic verbal fluency, and phonemic verbal fluency. After adjustment, the ABI group performance remained worse for working memory and semantic verbal fluency. In a simple correlation analysis including all of the subjects, the 6MWT was associated with global cognition, attention span, working memory, information processing speed, inhibitory control/impulsivity, semantic verbal fluency, and global ECF. After adjustment, all the associations remained statistically significant. Conclusion This study found an independent association between

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

    Science.gov (United States)

    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.

  11. A new wall function boundary condition including heat release effect for supersonic combustion flows

    International Nuclear Information System (INIS)

    Gao, Zhen-Xun; Jiang, Chong-Wen; Lee, Chun-Hian

    2016-01-01

    Highlights: • A new wall function including heat release effect is theoretically derived. • The new wall function is a unified form holding for flows with/without combustion. • The new wall function shows good results for a supersonic combustion case. - Abstract: A new wall function boundary condition considering combustion heat release effect (denoted as CWFBC) is proposed, for efficient predictions of skin friction and heat transfer in supersonic combustion flows. Based on a standard flow model including boundary-layer combustion, the Shvab–Zeldovich coupling parameters are introduced to derive a new velocity law-of-the-wall including the influence of combustion. For the temperature law-of-the-wall, it is proposed to use the enthalpy–velocity relation, instead of the Crocco–Busemann equation, to eliminate explicit influence of chemical reactions. The obtained velocity and temperature law-of-the-walls constitute the CWFBC, which is a unified form simultaneously holding for single-species, multi-species mixing and multi-species reactive flows. The subsequent numerical simulations using this CWFBC on an experimental case indicate that the CWFBC could accurately reflect the influences on the skin friction and heat transfer by the chemical reactions and heat release, and show large improvements compared to previous WFBC. Moreover, the CWFBC can give accurate skin friction and heat flux for a coarse mesh with y"+ up to 200 for the experimental case, except for slightly larger discrepancy of the wall heat flux around ignition position.

  12. Personality Changes in Patients with Vestibular Dysfunction

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    Paul eSmith

    2013-10-01

    Full Text Available The vestibular system is a sensory system that has evolved to detect linear and angular acceleration of the head in all planes so that the brain is not predominantly reliant on visual information to determine self-motion. Since the vestibular system first evolved in invertebrate species in order to detect gravitational vertical, it is likely that the central nervous system has developed a special dependence upon vestibular input. In addition to the deficits in eye movement and postural reflexes that occur following vestibular dysfunction, there is convincing evidence that vestibular loss also causes cognitive and emotional disorders, some of which may be due to the reflexive deficits and some of which are related to the role that ascending vestibular pathways to the limbic system and cortex play in the sense of spatial orientation. Beyond this, however, patients with vestibular disorders have been reported to experience other personality changes that suggest that vestibular sensation is implicated in the sense of self. These are depersonalisation and derealisation symptoms such as feeling ‘spaced out’, ‘body feeling strange’ and ‘not feeling in control of self’. We suggest in this review that these symptoms suggest that the vestibular system may make a unique contribution to the concept of self through the information regarding self-motion and self-location that it transmits, albeit indirectly, to areas of the brain such as the temporo-parietal junction.

  13. TS Fuzzy Model-Based Controller Design for a Class of Nonlinear Systems Including Nonsmooth Functions

    DEFF Research Database (Denmark)

    Vafamand, Navid; Asemani, Mohammad Hassan; Khayatiyan, Alireza

    2018-01-01

    This paper proposes a novel robust controller design for a class of nonlinear systems including hard nonlinearity functions. The proposed approach is based on Takagi-Sugeno (TS) fuzzy modeling, nonquadratic Lyapunov function, and nonparallel distributed compensation scheme. In this paper, a novel...... criterion, new robust controller design conditions in terms of linear matrix inequalities are derived. Three practical case studies, electric power steering system, a helicopter model and servo-mechanical system, are presented to demonstrate the importance of such class of nonlinear systems comprising...

  14. Representing uncertainty in objective functions: extension to include the influence of serial correlation

    Science.gov (United States)

    Croke, B. F.

    2008-12-01

    The role of performance indicators is to give an accurate indication of the fit between a model and the system being modelled. As all measurements have an associated uncertainty (determining the significance that should be given to the measurement), performance indicators should take into account uncertainties in the observed quantities being modelled as well as in the model predictions (due to uncertainties in inputs, model parameters and model structure). In the presence of significant uncertainty in observed and modelled output of a system, failure to adequately account for variations in the uncertainties means that the objective function only gives a measure of how well the model fits the observations, not how well the model fits the system being modelled. Since in most cases, the interest lies in fitting the system response, it is vital that the objective function(s) be designed to account for these uncertainties. Most objective functions (e.g. those based on the sum of squared residuals) assume homoscedastic uncertainties. If model contribution to the variations in residuals can be ignored, then transformations (e.g. Box-Cox) can be used to remove (or at least significantly reduce) heteroscedasticity. An alternative which is more generally applicable is to explicitly represent the uncertainties in the observed and modelled values in the objective function. Previous work on this topic addressed the modifications to standard objective functions (Nash-Sutcliffe efficiency, RMSE, chi- squared, coefficient of determination) using the optimal weighted averaging approach. This paper extends this previous work; addressing the issue of serial correlation. A form for an objective function that includes serial correlation will be presented, and the impact on model fit discussed.

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    Andreas Sprenger

    2017-09-01

    Full Text Available 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

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

    Science.gov (United States)

    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

  18. A Cross-sectional Survey and Cross-sectional Clinical Trial to Determine the Prevalence and Management of Eye Movement Disorders and Vestibular Dysfunction in Post-Stroke Patients in the Sub-Acute Phase: Protocol.

    Science.gov (United States)

    van Wyk, Andoret; Eksteen, Carina A; Becker, Piet J; Heinze, Barbara M

    2016-01-01

    Visual impairment, specifically eye movement disorders and vestibular dysfunction may have a negative influence on the functional recovery in post-stroke patients. This type of sensory dysfunction may further be associated with poor functional outcome in patients' post-stroke. In phase 1, a cross-sectional survey ( n  = 100) will be conducted to determine the prevalence of eye movement disorders and vestibular dysfunction in patients who sustained a stroke. A cross-sectional clinical trial ( n  = 60) will be conducted during phase 2 of the study to determine the effect of the combination of vestibular rehabilitation therapy (VRT) and visual scanning exercises (VSE) (experimental group) integrated with task-specific activities compared with the effect of task-specific activities as an intervention (control group) on patients who present with eye movement impairment and central vestibular dysfunction post-stroke. An audiologist will assess (a) visual acuity (static and dynamic), (b) nystagmus, (c) saccadic eye movements, (d) smooth pursuit eye movements, (e) vestibulo-ocular reflex, and (f) saccular, utricular, and vestibular nerve function. An independent physiotherapist will assess (1) cognitive function, (2) residual oculomotor visual performance, (3) visual-perceptual system, (4) functional balance, (5) gait, (6) functional ability, (7) presence of anxiety and/or depression, and (8) level of participation in physical activity. Ethics approval has been obtained from the Ethics Committee of the Faculty of Health Sciences at the University of Pretoria (UP) (374/2015). The study will be submitted as fulfillment for the PhD degree at UP. Dissemination will include submission to peer-reviewed professional journals and presentation at congresses. Training of rehabilitation team members on the integration of VSE and VRT into task-specific activities in rehabilitation will be done if the outcome of the experimental group's functional performance is clinically and

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

    Science.gov (United States)

    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.

  20. Clinical Characteristics and Etiology of Bilateral Vestibular Loss in a Cohort from Central Illinois

    Directory of Open Access Journals (Sweden)

    Jorge C. Kattah

    2018-03-01

    Full Text Available BackgroundPrevious series of bilateral vestibular loss (BVL identified numerous etiologies, but surprisingly, a cause in a significant number of cases remains unknown. In an effort to understand possible etiology and management strategies, a global effort is currently in progress. Here, I contribute my 10-year experience with both acute and chronic BVL during the 2007–2017 decade.MethodsThis is a retrospective review of the charts and EMR of patients diagnosed with BVL in the last 10 years. Following Institutional IRB approval, we identified 57 patients with a diagnosis of BVL and utilized the current diagnostic criteria listed by the Barany society (1. The inclusion criteria included patients with BVL of any cause, within an age span older than 18 and a neuro-otologic examination supporting the clinical impression of BVL.ResultsDuring the current decade 2007–2017, I identified two broad categories of BVL (acute and chronic in 57 patients; only 41 of them had records available. The etiology includes: idiopathic: n = 9, Wernicke’s encephalopathy n = 11, superficial siderosis n = 3, paraneoplastic syndrome: n = 3, bilateral vestibular neuritis (recurrent AVS lasting days without cochlear symptoms n = 3, simultaneous ototoxicity of aminoglycoside and chemotherapy toxicity n = 2, MELAS n = 2, Meniere’s disease treated with intra-tympanic streptomycin in one ear n = 1, acute phenytoin intoxication: n = 1, combined chronic unilateral tumor-related vestibulopathy and new contralateral vestibular neuritis (this patient presented with Betcherew’s phenomenon n = 1, bilateral AICA stroke n = 1, mixed spinocerebellar ataxia type 3, n = 2 and CANVAS n = 2.ConclusionThis cohort included a 28% overall incidence of acute and subacute BVL; among them, 65% improved with intervention. In the thiamine deficiency group, specifically, the vestibular function improved in 80% of the patients. Even though

  1. Comparative analysis of vestibular ecomorphology in birds.

    Science.gov (United States)

    Benson, Roger B J; Starmer-Jones, Ethan; Close, Roger A; Walsh, Stig A

    2017-12-01

    The bony labyrinth of vertebrates houses the semicircular canals. These sense rotational accelerations of the head and play an essential role in gaze stabilisation during locomotion. The sizes and shapes of the semicircular canals have hypothesised relationships to agility and locomotory modes in many groups, including birds, and a burgeoning palaeontological literature seeks to make ecological interpretations from the morphology of the labyrinth in extinct species. Rigorous tests of form-function relationships for the vestibular system are required to support these interpretations. We test the hypothesis that the lengths, streamlines and angles between the semicircular canals are related to body size, wing kinematics and flying style in birds. To do this, we applied geometric morphometrics and multivariate phylogenetic comparative methods to a dataset of 64 three-dimensional reconstructions of the endosseous labyrinth obtained using micro-computed tomography scanning of bird crania. A strong relationship between centroid size of the semicircular canals and body size indicates that larger birds have longer semicircular canals compared with their evolutionary relatives. Wing kinematics related to manoeuvrability (and quantified using the brachial index) explain a small additional portion of the variance in labyrinth size. We also find strong evidence for allometric shape change in the semicircular canals of birds, indicating that major aspects of the shape of the avian labyrinth are determined by spatial constraints. The avian braincase accommodates a large brain, a large eye and large semicircular canals compared with other tetrapods. Negative allometry of these structures means that the restriction of space within the braincase is intense in small birds. This may explain our observation that the angles between planes of the semicircular canals of birds deviate more strongly from orthogonality than those of mammals, and especially from agile, gliding and flying

  2. Manual therapy with and without vestibular rehabilitation for cervicogenic dizziness: a systematic review

    Directory of Open Access Journals (Sweden)

    Lystad Reidar P

    2011-09-01

    Full Text Available Abstract Background Manual therapy is an intervention commonly advocated in the management of dizziness of a suspected cervical origin. Vestibular rehabilitation exercises have been shown to be effective in the treatment of unilateral peripheral vestibular disorders, and have also been suggested in the literature as an adjunct in the treatment of cervicogenic dizziness. The purpose of this systematic review is to evaluate the evidence for manual therapy, in conjunction with or without vestibular rehabilitation, in the management of cervicogenic dizziness. Methods A comprehensive search was conducted in the databases Scopus, Mantis, CINHAL and the Cochrane Library for terms related to manual therapy, vestibular rehabilitation and cervicogenic dizziness. Included studies were assessed using the Maastricht-Amsterdam criteria. Results A total of fifteen articles reporting findings from thirteen unique investigations, including five randomised controlled trials and eight prospective, non-controlled cohort studies were included in this review. The methodological quality of the included studies was generally poor to moderate. All but one study reported improvement in dizziness following either unimodal or multimodal manual therapy interventions. Some studies reported improvements in postural stability, joint positioning, range of motion, muscle tenderness, neck pain and vertebrobasilar artery blood flow velocity. Discussion Although it has been argued that manual therapy combined with vestibular rehabilitation may be superior in the treatment of cervicogenic dizziness, there are currently no observational and experimental studies demonstrating such effects. A rationale for combining manual therapy and vestibular rehabilitation in the management of cervicogenic dizziness is presented. Conclusion There is moderate evidence to support the use of manual therapy, in particular spinal mobilisation and manipulation, for cervicogenic dizziness. The evidence

  3. Proton beam stereotactic radiosurgery of vestibular schwannomas

    International Nuclear Information System (INIS)

    Harsh, Griffith R.; Thornton, Allan F.; Chapman, Paul H.; Bussiere, Marc R.; Rabinov, James D.; Loeffler, Jay S.

    2002-01-01

    Purpose: The proton beam's Bragg peak permits highly conformal radiation of skull base tumors. This study, prompted by reports of transient (30% each) and permanent (10% each) facial and trigeminal neuropathy after stereotactic radiosurgery of vestibular schwannomas with marginal doses of 16-20 Gy, assessed whether proton beam radiosurgery using a marginal dose of only 12 Gy could control vestibular schwannomas while causing less neuropathy. Methods and Materials: Sixty-eight patients (mean age 67 years) were treated between 1992 and 1998. The mean tumor volume was 2.49 cm 3 . The dose to the tumor margin (70% isodose line) was 12 Gy. The prospectively specified follow-up consisted of neurologic evaluation and MRI at 6, 12, 24, and 36 months. Results: After a mean clinical follow-up of 44 months and imaging follow-up of 34 months in 64 patients, 35 tumors (54.7%) were smaller and 25 (39.1%) were unchanged (tumor control rate 94%; actuarial control rate 94% at 2 years and 84% at 5 years). Three tumors enlarged: one shrank after repeated radiosurgery, one remained enlarged at the time of unrelated death, and one had not been imaged for 4 years in a patient who remained asymptomatic at last follow-up. Intratumoral hemorrhage into one stable tumor required craniotomy that proved successful. Thus, 97% of tumors required no additional treatment. Three patients (4.7%) underwent shunting for hydrocephalus evident as increased ataxia. Of 6 patients with functional hearing ipsilaterally, 1 improved, 1 was unchanged, and 4 progressively lost hearing. Cranial neuropathies were infrequent: persistent facial hypesthesia (2 new, 1 exacerbated; 4.7%); intermittent facial paresthesias (5 new, 1 exacerbated; 9.4%); persistent facial weakness (2 new, 1 exacerbated; 4.7%) requiring oculoplasty; transient partial facial weakness (5 new, 1 exacerbated; 9.4%), and synkinesis (5 new, 1 exacerbated; 9.4%). Conclusion: Proton beam stereotactic radiosurgery of vestibular schwannomas at the

  4. The frog vestibular system as a model for lesion-induced plasticity: basic neural principles and implications for posture control

    Directory of Open Access Journals (Sweden)

    Francois M Lambert

    2012-04-01

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

  5. Defining the breeding goal for a sheep breed including production and functional traits using market data.

    Science.gov (United States)

    Theodoridis, A; Ragkos, A; Rose, G; Roustemis, D; Arsenos, G

    2017-11-16

    In this study, the economic values for production and functional traits of dairy sheep are estimated through the application of a profit function model using farm-level technical and economic data. The traits incorporated in the model were milk production, prolificacy, fertility, milking speed, longevity and mastitis occurrence. The economic values for these traits were derived as the approximate partial derivative of the specified profit function. A sensitivity analysis was also conducted in order to examine how potential changes in input and output prices would affect the breeding goal. The estimated economic values of the traits revealed their economic impact on the definition of the breeding goal for the specified production system. Milk production and fertility had the highest economic values (€40.30 and €20.28 per standard genetic deviation (SDa)), while, mastitis only had a low negative value of -0.57 €/SDa. Therefore, breeding for clinical mastitis will have a minor impact on farm profitability because it affects a small proportion of the flock and has low additive variance. The production traits, which include milk production, prolificacy and milking speed, contributed most to the breeding goal (70.0%), but functional traits still had a considerable share (30.0%). The results of this study highlight the importance of the knowledge of economic values of traits in the design of a breeding program. It is also suggested that the production and functional traits under consideration can be categorized as those which can be efficiently treated through genetic improvement (e.g. milk production and fertility) while others would be better dealt with through managerial interventions (e.g. mastitis occurrence). Also, sub-clinical mastitis that affects a higher proportion of flocks could have a higher contribution to breeding goals.

  6. Magnetic Vestibular Stimulation in Subjects with Unilateral Labyrinthine Disorders

    Directory of Open Access Journals (Sweden)

    Bryan Kevin Ward

    2014-03-01

    Full Text Available We recently discovered that static magnetic fields from high-strength MRI machines induce nystagmus in all normal humans, and that a magnetohydrodynamic (MHD Lorentz force, derived from ionic currents in the endolymph and pushing on the cupula, best explains this effect. Individuals with no labyrinthine function have no nystagmus. The influence of magnetic vestibular stimulation (MVS in individuals with unilateral loss of labyrinthine function is unknown and may provide insight into mechanism of MVS. These individuals should experience MVS, but with differences consistent with their residual labyrinthine function. We recorded eye movements in the static magnetic field of a 7T MRI machine in nine individuals with unilateral labyrinthine hypofunction, as determined by head impulse testing and vestibular-evoked myogenic potentials (VEMP. Eye movements were recorded using infrared videooculography. Static head positions were varied in pitch with the body supine, and slow-phase eye velocity (SPV was assessed. All subjects exhibited predominantly horizontal nystagmus after entering the magnet head-first, lying supine. The SPV direction reversed when entering feet-first. Pitching chin-to-chest caused subjects to reach a null point for horizontal SPV. Right unilateral vestibular hypofunction (UVH subjects developed slow-phase-up nystagmus and left UVH subjects, slow-phase-down nystagmus. Vertical and torsional components were consistent with superior semicircular canal excitation or inhibition, respectively, of the intact ear. These findings provide compelling support for the hypothesis that MVS is a result of a Lorentz force and suggest that the function of individual structures within the labyrinth can be assessed with MVS. As a novel method of comfortable and sustained labyrinthine stimulation, MVS can provide new insights into vestibular physiology and pathophysiology.

  7. Etiopathophysiological assessment of cases with chronic daily headache: A functional magnetic resonance imaging included investigation

    Science.gov (United States)

    Hashemi, Akram; Nami, Mohammad Torabi; Oghabian, Mohammad Ali; Ganjgahi, Habib; Vahabi, Zahra

    2012-01-01

    Background Chronic daily headache (CDH) has gained little attention in functional neuro-imaging. When no structural abnormality is found in CDH, defining functional correlates between activated brain regions during headache bouts may provide unique insights towards understanding the pathophysiology of this type of headache. Methods We recruited four CDH cases for comprehensive assessments, including history taking, physical examinations and neuropsychological evaluations (The Addenbrooke's Cognitive Evaluation, Beck's Anxiety and Depression Inventories, Pittsburg Sleep Quality Index and Epworth Sleepiness Scale). Visual analogue scale (VAS) was used to self-rate the intensity of headache. Patients then underwent electroencephalography (EEG), transcranial Doppler (TCD) and functional magnetic resonance imaging (fMRI) evaluations during maximal (VAS = 8-10/10) and off-headache (VAS = 0-3/10) conditions. Data were used to compare in both conditions. We also used BOLD (blood oxygen level dependent) -group level activation map fMRI to possibly locate headache-related activated brain regions. Results General and neurological examinations as well as conventional MRIs were unremarkable. Neuropsychological assessments showed moderate anxiety and depression in one patient and minimal in others. Unlike three patients, maximal and off-headache TCD evaluation in one revealed increased middle cerebral artery blood flow velocity, at the maximal pain area. Although with no seizure history, the same patient's EEG showed paroxysmal epileptic discharges during maximal headache intensity, respectively. Group level activation map fMRI showed activated classical pain matrix regions upon headache bouts (periaqueductal grey, substantia nigra and raphe nucleus), and markedly bilateral occipital lobes activation. Conclusion The EEG changes were of note. Furthermore, the increased BOLD signals in areas outside the classical pain matrix (i.e. occipital lobes) during maximal headaches may

  8. Posture, head stability, and orientation recovery during vestibular regeneration in pigeons.

    Science.gov (United States)

    Dickman, J David; Lim, Insook

    2004-09-01

    Compensatory behavior such as oculomotor, gaze, and postural responses that occur during movement largely depend upon a functioning vestibular system. In the present study, the initial loss and subsequent recovery of postural and head stability in pigeons undergoing vestibular regeneration were examined. Adult pigeons were trained to manipulate a straight run chamber to peck an illuminated key for fluid reward. Six behavioral measures assessing performance, posture, and head stability were quantified. These included run latency, steps (walking), path negotiation (lane changes), gaze saccades, head bobs, and head shakes. Once normative values were obtained for four birds, complete lesion of all receptor cells and denervation of the epithelia in the vestibular endorgans were produced using a single intralabyrinthine application of streptomycin sulfate. Each bird was then tested at specific times during regeneration and the same behavioral measures examined. At 7 days post-streptomycin treatment (PST), all birds exhibited severe postural and head instability, with tremors, head shakes, staggering, and circling predominating. No normal trial runs, walking, gaze saccades, or head bobs were present. Many of these dysfunctions persisted through 3-4 weeks PST. Gradually, tremor and head shakes diminished and were replaced with an increasing number of normal head bobs during steps and gaze saccades. Beginning at 4 weeks PST, but largely inaccurate, was the observed initiation of directed steps, less staggering, and some successful path negotiation. As regeneration progressed, spatial orientation and navigation ability increased and, by 49 days PST, most trials were successful. By 70 days PST, all birds had recovered to pretreatment levels. Thus, it was observed that ataxia must subside, coincident with normalized head and postural stability prior to the recovery of spatial orientation and path navigation recovery. Parallels in recovery were drawn to hair cell regeneration

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

    Science.gov (United States)

    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.

  10. [Functional results of cryosurgical procedures in rhegmatogenous retinal detachment including macula region - our experience].

    Science.gov (United States)

    Chrapek, O; Sín, M; Jirková, B; Jarkovský, J; Rehák, J

    2013-10-01

    Aim of this study is to evaluate retrospectively functional results of cryosurgical treatment of uncomplicated, idiopathic rhegmatogenous retinal detachment including macula region in phakic patients operated on at the Department of Ophthalmology, Faculty Hospital, Palacký University, Olomouc, Czech Republic, E.U., during the period 2002 -2013, and to evaluate the significance of the macula detachment duration for the final visual acuity. In the study group were included 56 eyes of 56 patients operated in the years 2003 - 2012 at the Department of Ophthalmology, Faculty Hospital, Palacký University, Olomouc. All patients were phakic and in all of them, the retinal detachment including the macula region was diagnosed. The mean follow-up period of the patients was 8,75 months. The initial and final visual acuity testing were performed. Comparing the initial and final visual acuity we rated the level of the visual acuity change. The result was stated as improved, if the visual acuity improved by 1 or more lines on the ETDRS chart. The result was rated as stabilized, if the visual acuity remained the same or it changed by 1 line of the ETDRS chart only. The result was evaluated as worsened, if the visual acuity decreased by 1 or more lines of the ETDRS chart. In the followed-up group, the authors compared visual acuity levels in patients with the macula detachment duration 10 days and 11 days. For the statistical evaluation of achieved results, the Mann - Whitney U test was used. The visual acuity improved in 49 (87 %), did not changed in 5 (9 %) and worsened in 2 (4 %) patients. The patients with macula detachment duration 10 days achieved statistically significant better visual acuity than patients with macula detachment duration 11 days. Patients with macula detachment duration 10 days have better prognosis for functional result than patients with macula detachment duration 11 days.

  11. Diagnostics and therapy of vestibular schwannomas – an interdisciplinary challenge

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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, 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.

  13. Communication: importance sampling including path correlation in semiclassical initial value representation calculations for time correlation functions.

    Science.gov (United States)

    Pan, Feng; Tao, Guohua

    2013-03-07

    Full semiclassical (SC) initial value representation (IVR) for time correlation functions involves a double phase space average over a set of two phase points, each of which evolves along a classical path. Conventionally, the two initial phase points are sampled independently for all degrees of freedom (DOF) in the Monte Carlo procedure. Here, we present an efficient importance sampling scheme by including the path correlation between the two initial phase points for the bath DOF, which greatly improves the performance of the SC-IVR calculations for large molecular systems. Satisfactory convergence in the study of quantum coherence in vibrational relaxation has been achieved for a benchmark system-bath model with up to 21 DOF.

  14. Vestibular Rehabilitation in a Patient with Whiplash-associated Disorders

    Directory of Open Access Journals (Sweden)

    Kwo-Shieng Tuo

    2006-12-01

    Full Text Available Whiplash-associated disorders are characterized by multiple physical complaints after a flexion-extension trauma to the neck. They are difficult to treat, and they often result in great impact on the patient's quality of life. In this paper, the comprehensive treatment of a patient with whiplash-associated disorders is presented. The purpose is to highlight the importance of accurate diagnosis and appropriate treatment plans to improve patients' quality of life. This 23-year-old woman experienced a traffic accident which caused severely painful neck disability, numbness over bilateral upper limbs, dizziness, double vision and loss of balance. Among these symptoms, dizziness was the problem that bothered the patient most. She received a comprehensive rehabilitation program including physical modalities, trigger point injections for relief of pain, as well as a vestibular rehabilitation program, which included exercises challenging and improving her balance function, head-eye coordination exercise, visual-ocular control exercise and sensory substitution-promoting exercises. She resumed her previous full-time work after 3 weeks of treatment. This successfully treated case illustrates the importance of correct diagnosis and appropriate treatment for patients who suffer from whiplash-associated disorders.

  15. The influence of caffeine on calorics and cervical vestibular evoked myogenic potentials (cVEMPs).

    Science.gov (United States)

    McNerney, Kathleen; Coad, Mary Lou; Burkard, Robert

    2014-03-01

    Prior to undergoing vestibular function testing, it is not uncommon for clinicians to request that patients abstain from caffeine 24 hr prior to the administration of the tests. However, there is little evidence that caffeine affects vestibular function. To evaluate whether the results from two tests commonly used in a clinical setting to assess vestibular function (i.e., calorics and the cervical vestibular evoked myogenic potential [cVEMP]) are affected by caffeine. Subjects were tested with and without consuming a moderate amount of caffeine prior to undergoing calorics and cVEMPs. Thirty young healthy controls (mean = 23.28 yr; females = 21). Subjects were excluded if they reported any history of vestibular/balance impairment. The Variotherm Plus Caloric Irrigator was used to administer the water, while the I-Portal VNG software was used to collect and analyze subjects' eye movements. The TECA Evoked Potential System was used for the cVEMP stimulus presentation as well as for the data collection. During cVEMP collection, subjects were asked to monitor their sternocleidomastoid muscle contraction with a Delsys EMG monitor. IBM SPSS Statistics 20 was used to statistically analyze the results via paired t-tests. Analysis of the data revealed that ingestion of caffeine did not significantly influence the results of either test of vestibular function. The results revealed that a moderate amount of caffeine does not have a clinically significant effect on the results from caloric and cVEMP tests in young healthy adults. Future research is necessary to determine whether similar results would be obtained from individuals with a vestibular impairment, as well as older adults. American Academy of Audiology.

  16. Representation of visual gravitational motion in the human vestibular cortex.

    Science.gov (United States)

    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. Epidemiology of vestibular vertigo: a neurotologic survey of the general population.

    Science.gov (United States)

    Neuhauser, H K; von Brevern, M; Radtke, A; Lezius, F; Feldmann, M; Ziese, T; Lempert, T

    2005-09-27

    The purpose of this study was to determine the prevalence and incidence of vestibular vertigo in the general population and to describe its clinical characteristics and associated factors. The neurotologic survey had a two-stage general population sampling design: nationwide modified random digit dialing sampling for participation in the German National Telephone Health Interview Survey 2003 (response rate 52%) with screening of a random sample of 4,869 participants for moderate or severe dizziness or vertigo, followed by detailed neurotologic interviews developed through piloting and validation (n = 1,003, response rate 87%). Diagnostic criteria for vestibular vertigo were rotational vertigo, positional vertigo, or recurrent dizziness with nausea and oscillopsia or imbalance. Vestibular vertigo was detected by our interview with a specificity of 94% and a sensitivity of 84[corrected]% in a concurrent validation study using neurotology clinic diagnoses as an accepted standard (n = 61). The lifetime prevalence of vestibular vertigo was 7.4[corrected]%, the 1-year prevalence was 4.9[corrected]%, and the incidence was 1.4[corrected]%. In 80% of affected individuals, vertigo resulted in a medical consultation, interruption of daily activities, or sick leave. Female sex, age, lower educational level, and various comorbid conditions, including tinnitus, depression, and several cardiovascular diseases and risk factors, were associated with vestibular vertigo in the past year in univariate analysis. In multivariable analysis, only female sex, self-reported depression, tinnitus, hypertension, and dyslipidemia had an independent effect on vestibular vertigo. Vestibular vertigo is common in the general population, affecting [corrected] 5% of adults in 1 year. The frequency and health care impact of vestibular symptoms at the population level have been underestimated.

  18. Association between vestibular schwannomas and mobile phone use

    OpenAIRE

    Moon, In Seok; Kim, Bo Gyung; Kim, Jinna; Lee, Jong Dae; Lee, Won-Sang

    2013-01-01

    Vestibular schwannomas (VSs) grow in the region where the energy from mobile phone use is absorbed. We examined the associations of VSs with mobile phone use. This study included 119 patients who had undergone surgical tumor removal. We used two approaches in this investigation. First, a case–control study for the association of mobile phone use and incidence of VSs was conducted. Both cases and controls were investigated with questions based on INTERPHONE guidelines. Amount of mobile phone u...

  19. Optimisation of chromatographic resolution using objective functions including both time and spectral information.

    Science.gov (United States)

    Torres-Lapasió, J R; Pous-Torres, S; Ortiz-Bolsico, C; García-Alvarez-Coque, M C

    2015-01-16

    The optimisation of the resolution in high-performance liquid chromatography is traditionally performed attending only to the time information. However, even in the optimal conditions, some peak pairs may remain unresolved. Such incomplete resolution can be still accomplished by deconvolution, which can be carried out with more guarantees of success by including spectral information. In this work, two-way chromatographic objective functions (COFs) that incorporate both time and spectral information were tested, based on the peak purity (analyte peak fraction free of overlapping) and the multivariate selectivity (figure of merit derived from the net analyte signal) concepts. These COFs are sensitive to situations where the components that coelute in a mixture show some spectral differences. Therefore, they are useful to find out experimental conditions where the spectrochromatograms can be recovered by deconvolution. Two-way multivariate selectivity yielded the best performance and was applied to the separation using diode-array detection of a mixture of 25 phenolic compounds, which remained unresolved in the chromatographic order using linear and multi-linear gradients of acetonitrile-water. Peak deconvolution was carried out using the combination of orthogonal projection approach and alternating least squares. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Vestibular Loss in Older Adults Is Associated with Impaired Spatial Navigation: Data from the Triangle Completion Task

    Directory of Open Access Journals (Sweden)

    Yanjun Xie

    2017-04-01

    Full Text Available BackgroundVestibular inputs have been shown to play a critical role in spatial navigation. In this study, we sought to evaluate whether vestibular loss due to aging contributes to impaired spatial navigation as measured by the triangle completion task (TCT.Materials and methodsWe recruited three types of participants: young controls <55 years of age, older controls ≥55 years of age, and older patients from a Neurotology Clinic with evidence of vestibular physiologic impairment but who did not have any known vestibular disorder. We performed the cervical vestibular-evoked myogenic potential to evaluate saccular function and video head impulse testing to quantify horizontal semicircular canal vestibulo-ocular reflex gain. To assess spatial navigation ability, we administered the TCT, in which participants were conveyed along two segments of a pre-drawn triangular path and instructed to complete the final segment independently. We measured the angle (degrees and distance (centimeters of deviation from the correct trajectory. We evaluated the influence of vestibular inputs on TCT performance.ResultsForty-eight adults participated in the study (mean age: 62.0 years; 52.1% females, including 9 young controls, 15 older controls, and 24 clinic patients. Clinic patients had the greatest distance of deviation (67.7 cm, followed by older controls (45.4 cm, then young controls (27.8 cm; p < 0.01. Similarly, clinic patients had greater rotational angles (22.1° compared to older (13.3° and younger controls (12.4°; p < 0.01. Following multivariate linear regression adjusting for demographic variables, loss of otolith function was associated with an 18.2 cm increase in distance of deviation (95% CI: 15.2–47.4 and a 9.2° increase in rotational angle (95% CI: 3.0–15.5. Abnormal semicircular canal function was associated with a 26.0 cm increase in distance of deviation (95% CI: 0.2–51.8 and a 10.8° increase in rotational angle

  1. Home-Based Computer Gaming in Vestibular Rehabilitation of Gaze and Balance Impairment.

    Science.gov (United States)

    Szturm, Tony; Reimer, Karen M; Hochman, Jordan

    2015-06-01

    Disease or damage of the vestibular sense organs cause a range of distressing symptoms and functional problems that could include loss of balance, gaze instability, disorientation, and dizziness. A novel computer-based rehabilitation system with therapeutic gaming application has been developed. This method allows different gaze and head movement exercises to be coupled to a wide range of inexpensive, commercial computer games. It can be used in standing, and thus graded balance demands using a sponge pad can be incorporated into the program. A case series pre- and postintervention study was conducted of nine adults diagnosed with peripheral vestibular dysfunction who received a 12-week home rehabilitation program. The feasibility and usability of the home computer-based therapeutic program were established. Study findings revealed that using head rotation to interact with computer games, when coupled to demanding balance conditions, resulted in significant improvements in standing balance, dynamic visual acuity, gaze control, and walking performance. Perception of dizziness as measured by the Dizziness Handicap Inventory also decreased significantly. These preliminary findings provide support that a low-cost home game-based exercise program is well suited to train standing balance and gaze control (with active and passive head motion).

  2. Deconvolution of the vestibular evoked myogenic potential.

    Science.gov (United States)

    Lütkenhöner, Bernd; Basel, Türker

    2012-02-07

    The vestibular evoked myogenic potential (VEMP) and the associated variance modulation can be understood by a convolution model. Two functions of time are incorporated into the model: the motor unit action potential (MUAP) of an average motor unit, and the temporal modulation of the MUAP rate of all contributing motor units, briefly called rate modulation. The latter is the function of interest, whereas the MUAP acts as a filter that distorts the information contained in the measured data. Here, it is shown how to recover the rate modulation by undoing the filtering using a deconvolution approach. The key aspects of our deconvolution algorithm are as follows: (1) the rate modulation is described in terms of just a few parameters; (2) the MUAP is calculated by Wiener deconvolution of the VEMP with the rate modulation; (3) the model parameters are optimized using a figure-of-merit function where the most important term quantifies the difference between measured and model-predicted variance modulation. The effectiveness of the algorithm is demonstrated with simulated data. An analysis of real data confirms the view that there are basically two components, which roughly correspond to the waves p13-n23 and n34-p44 of the VEMP. The rate modulation corresponding to the first, inhibitory component is much stronger than that corresponding to the second, excitatory component. But the latter is more extended so that the two modulations have almost the same equivalent rectangular duration. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Heat pulse excitability of vestibular hair cells and afferent neurons

    Science.gov (United States)

    Brichta, Alan M.; Tabatabaee, Hessam; Boutros, Peter J.; Ahn, JoongHo; Della Santina, Charles C.; Poppi, Lauren A.; Lim, Rebecca

    2016-01-01

    In the present study we combined electrophysiology with optical heat pulse stimuli to examine thermodynamics of membrane electrical excitability in mammalian vestibular hair cells and afferent neurons. We recorded whole cell currents in mammalian type II vestibular hair cells using an excised preparation (mouse) and action potentials (APs) in afferent neurons in vivo (chinchilla) in response to optical heat pulses applied to the crista (ΔT ≈ 0.25°C per pulse). Afferent spike trains evoked by heat pulse stimuli were diverse and included asynchronous inhibition, asynchronous excitation, and/or phase-locked APs synchronized to each infrared heat pulse. Thermal responses of membrane currents responsible for APs in ganglion neurons were strictly excitatory, with Q10 ≈ 2. In contrast, hair cells responded with a mix of excitatory and inhibitory currents. Excitatory hair cell membrane currents included a thermoelectric capacitive current proportional to the rate of temperature rise (dT/dt) and an inward conduction current driven by ΔT. An iberiotoxin-sensitive inhibitory conduction current was also evoked by ΔT, rising in heat pulse excitability in vestibular sensory organs and provide quantitative methods for rational application of optical heat pulses to examine protein biophysics and manipulate cellular excitability. PMID:27226448

  4. Mobile phones: influence on auditory and vestibular systems.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  6. Effect of practicing yoga on cervical vestibular evoked myogenic potential.

    Science.gov (United States)

    Shambhu, Tejaswini; Kumar, Shubhaganga Dhrruva; Prabhu, Prashanth

    2017-10-01

    The present study attempted to determine the effect of practicing yoga on functioning of sacculo-collic pathway using cervical vestibular evoked myogenic potential (cVEMP). cVEMP was recorded from 40 participants (20 who practice yoga regularly and 20 who do not practice yoga regularly). The differences in amplitude of P1, N1, P1-N1 complex, asymmetry ratio and latencies of P1 and N1 of cVEMP were compared between both the groups. The results of the study showed that there was a significant increase (p yoga was significantly lower (Mean = 6.73) compared to the control group (Mean = 19.13). Multivariate regression analyses suggested that the number of years of yoga practice significantly predicted the amplitude of P1-N1 complex (β = 0.70, p yoga improves postural control and strengthens the muscles and vestibular system leading to enhanced cVEMP responses. The plastic changes in the vestibular system and increased muscular strength because of constant practicing of yoga could have led to changes in cVEMP responses. However, further studies on a larger group of individuals are essential for better clinical applicability of the results.

  7. Galvanic Vestibular Stimulation in Hemi-Spatial Neglect

    Directory of Open Access Journals (Sweden)

    David eWilkinson

    2014-01-01

    Full Text Available Hemi-spatial neglect is an attentional disorder in which the sufferer fails to acknowledge or respond to stimuli appearing in contralesional space. In recent years, it has become clear that a measurable reduction in contralesional neglect can occur during galvanic vestibular stimulation, a technique by which transmastoid, small amplitude current induces lateral, attentional shifts via asymmetric modulation of the left and right vestibular nerves. However, it remains unclear whether this reduction persists after stimulation is stopped. To estimate longevity of effect, we therefore conducted a double-blind, randomized, dose-response trial involving a group of stroke patients suffering from left-sided neglect (n=52, mean age=66 years. To determine whether repeated sessions of galvanic vestibular stimulation more effectively induce lasting relief than a single session, participants received 1, 5, or 10 sessions, each lasting 25mins, of sub-sensory, left-anodal right-cathodal noisy direct current (mean amplitude=1mA. Ninety five percent confidence intervals indicated that all three treatment arms showed a statistically significant improvement between the pre-stimulation baseline and the final day of stimulation on the primary outcome measure, the conventional tests of the Behavioural Inattention Test. More remarkably, this change (mean change=28%, SD=18 was still evident 1month later. Secondary analyses indicated an allied increase of 20% in median Barthel Index score, a measure of functional capacity, in the absence of any adverse events or instances of participant non-compliance. Together these data suggest that galvanic vestibular stimulation, a simple, cheap technique suitable for home-based administration, may produce lasting reductions in neglect that are clinically important. Further protocol optimization is now needed ahead of a larger effectiveness study.

  8. Pulmonary Function After Treatment for Embryonal Brain Tumors on SJMB03 That Included Craniospinal Irradiation

    International Nuclear Information System (INIS)

    Green, Daniel M.; Merchant, Thomas E.; Billups, Catherine A.; Stokes, Dennis C.; Broniscer, Alberto; Bartels, Ute; Chintagumpala, Murali; Hassall, Timothy E.; Gururangan, Sridharan; McCowage, Geoffrey B.; Heath, John A.; Cohn, Richard J.; Fisher, Michael J.; Srinivasan, Ashok; Robinson, Giles W.; Gajjar, Amar

    2015-01-01

    Purpose: The treatment of children with embryonal brain tumors (EBT) includes craniospinal irradiation (CSI). There are limited data regarding the effect of CSI on pulmonary function. Methods: Protocol SJMB03 enrolled patients 3 to 21 years of age with EBT. Pulmonary function tests (PFTs) (forced expiratory volume in 1 second [FEV 1 ] and forced vital capacity [FVC] by spirometry, total lung capacity [TLC] by nitrogen washout or plethysmography, and diffusing capacity of the lung for carbon monoxide corrected for hemoglobin [DLCO corr ]) were obtained. Differences between PFTs obtained immediately after the completion of CSI and 24 or 60 months after the completion of treatment (ACT) were compared using exact Wilcoxon signed-rank tests and repeated-measures models. Results: Between June 24, 2003, and March 1, 2010, 303 eligible patients (spine dose: ≤2345 cGy, 201; >2345 cGy, 102; proton beam, 20) were enrolled, 260 of whom had at least 1 PFT. The median age at diagnosis was 8.9 years (range, 3.1-20.4 years). The median thoracic spinal radiation dose was 23.4 Gy (interquartile range [IQR], 23.4-36.0 Gy). The median cyclophosphamide dose was 16.0 g/m 2 (IQR, 15.7-16.0 g/m 2 ). At 24 and 60 months ACT, DLCO corr was <75% predicted in 23% (27/118) and 25% (21/84) of patients, FEV 1 was <80% predicted in 20% (34/170) and 29% (32/109) of patients, FVC was <80% predicted in 27% (46/172) and 28% (30/108) of patients, and TLC was <75% predicted in 9% (13/138) and 11% (10/92) of patients. DLCO corr was significantly decreased 24 months ACT (median difference [MD] in % predicted, 3.00%; P=.028) and 60 months ACT (MD in % predicted, 6.00%; P=.033) compared with the end of radiation therapy. These significant decreases in DLCO corr were also observed in repeated-measures models (P=.011 and P=.032 at 24 and 60 months ACT, respectively). Conclusions: A significant minority of EBT survivors experience PFT deficits after CSI. Continued monitoring of this cohort

  9. Pulmonary Function After Treatment for Embryonal Brain Tumors on SJMB03 That Included Craniospinal Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Green, Daniel M., E-mail: daniel.green@stjude.org [Department of Epidemiology and Cancer Control, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Merchant, Thomas E. [Department of Radiological Sciences, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Billups, Catherine A. [Department of Biostatistics, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Stokes, Dennis C. [Department of Pediatrics, University of Tennessee School of Medicine, Memphis, Tennessee (United States); Broniscer, Alberto [Department of Oncology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Bartels, Ute [Department of Haematology and Oncology, The Hospital for Sick Children, Toronto, Ontario (Canada); Chintagumpala, Murali [Department of Pediatric Medicine, Texas Children' s Cancer and Hematology Centers, Baylor College of Medicine, Houston, Texas (United States); Hassall, Timothy E. [Department of Haematology and Oncology, Royal Children' s Hospital, Brisbane (Australia); Gururangan, Sridharan [Department of Pediatrics, Duke University Medical Center, Durham, North Carolina (United States); McCowage, Geoffrey B. [Department of Pediatrics, Children' s Hospital at Westmead, Sydney (Australia); Heath, John A. [Children' s Cancer Center, Royal Children' s Hospital Melbourne, Melbourne (Australia); Cohn, Richard J. [Department of Clinical Oncology, Sydney Children' s Hospital, Sydney (Australia); Fisher, Michael J. [Department of Pediatrics, Children' s Hospital of Philadelphia, Philadelphia, Pennsylvania (United States); Srinivasan, Ashok [Department of Bone Marrow Transplantation & Cellular Therapy, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Robinson, Giles W.; Gajjar, Amar [Department of Oncology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States)

    2015-09-01

    Purpose: The treatment of children with embryonal brain tumors (EBT) includes craniospinal irradiation (CSI). There are limited data regarding the effect of CSI on pulmonary function. Methods: Protocol SJMB03 enrolled patients 3 to 21 years of age with EBT. Pulmonary function tests (PFTs) (forced expiratory volume in 1 second [FEV{sub 1}] and forced vital capacity [FVC] by spirometry, total lung capacity [TLC] by nitrogen washout or plethysmography, and diffusing capacity of the lung for carbon monoxide corrected for hemoglobin [DLCO{sub corr}]) were obtained. Differences between PFTs obtained immediately after the completion of CSI and 24 or 60 months after the completion of treatment (ACT) were compared using exact Wilcoxon signed-rank tests and repeated-measures models. Results: Between June 24, 2003, and March 1, 2010, 303 eligible patients (spine dose: ≤2345 cGy, 201; >2345 cGy, 102; proton beam, 20) were enrolled, 260 of whom had at least 1 PFT. The median age at diagnosis was 8.9 years (range, 3.1-20.4 years). The median thoracic spinal radiation dose was 23.4 Gy (interquartile range [IQR], 23.4-36.0 Gy). The median cyclophosphamide dose was 16.0 g/m{sup 2} (IQR, 15.7-16.0 g/m{sup 2}). At 24 and 60 months ACT, DLCO{sub corr} was <75% predicted in 23% (27/118) and 25% (21/84) of patients, FEV{sub 1} was <80% predicted in 20% (34/170) and 29% (32/109) of patients, FVC was <80% predicted in 27% (46/172) and 28% (30/108) of patients, and TLC was <75% predicted in 9% (13/138) and 11% (10/92) of patients. DLCO{sub corr} was significantly decreased 24 months ACT (median difference [MD] in % predicted, 3.00%; P=.028) and 60 months ACT (MD in % predicted, 6.00%; P=.033) compared with the end of radiation therapy. These significant decreases in DLCO{sub corr} were also observed in repeated-measures models (P=.011 and P=.032 at 24 and 60 months ACT, respectively). Conclusions: A significant minority of EBT survivors experience PFT deficits after CSI

  10. Diversity and functional traits of culturable microbiome members, including cyanobacteria in the rice phyllosphere.

    Science.gov (United States)

    Venkatachalam, S; Ranjan, K; Prasanna, R; Ramakrishnan, B; Thapa, S; Kanchan, A

    2016-07-01

    The diversity and abundance of culturable microbiome members of the rice phyllosphere was investigated using cv. Pusa Punjab Basmati 1509. Both diversity and species richness of bacteria were significantly higher in plants in pots in a semi-controlled environment than those in fields. Application of fertilisers reduced both diversity and species richness in field-grown plants under a conventional flooded system of rice intensification (SRI) and in dry-seeded rice (DSR) modes. Sequence analyses of 16S rDNA of culturable bacteria, those selected after amplified ribosomal DNA restriction analysis (ARDRA), showed the dominance of α-proteobacteria (35%) and actinobacteria (38%); Pantoea, Exiguobacterium and Bacillus were common among the culturable phyllospheric bacteria. About 34% of 83 culturable bacterial isolates had higher potential (>2 μg·ml(-1) ) for indole acetic acid production in the absence of tryptophan. Interestingly, the phyllosphere bacterial isolates from the pot experiment had significantly higher potential for nitrogen fixation than isolates from the field experiment. Enrichment for cyanobacteria showed both unicellular forms and non-heterocystous filaments under aerobic as well as anaerobic conditions. PCR-DGGE analysis of these showed that aerobic and anaerobic conditions as well as the three modes of cultivation of rice in the field strongly influenced the number and abundance of phylotypes. The adaptability and functional traits of these culturable microbiome members suggest enormous diversity in the phyllosphere, including potential for plant growth promotion, which was also significantly influenced by the different methods of growing rice. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  11. Management of vestibular schwannomas with linear accelerator-based stereotactic radiosurgery: a single center experience.

    Science.gov (United States)

    Sager, Omer; Beyzadeoglu, Murat; Dincoglan, Ferrat; Demiral, Selcuk; Uysal, Bora; Gamsiz, Hakan; Oysul, Kaan; Dirican, Bahar; Sirin, Sait

    2013-01-01

    The primary goal of treatment for vestibular schwannoma is to achieve local control without comprimising regional cranial nerve function. Stereotactic radiosurgery has emerged as a viable therapeutic option for vestibular schwannoma. The aim of the study is to report our 15-year single center experience using linear accelerator-based stereotactic radiosurgery in the management of patients with vestibular schwannoma. Between July 1998 and January 2013, 68 patients with unilateral vestibular schwannoma were treated using stereotactic radiosurgery at the Department of Radiation Oncology, Gulhane Military Medical Academy. All patients underwent high-precision stereotactic radiosurgery using a linear accelerator with 6-MV photons. Median follow-up time was 51 months (range, 9-107). Median age was 45 years (range, 20-77). Median dose was 12 Gy (range, 10-13) prescribed to the 85%-95% isodose line encompassing the target volume. Local tumor control in patients with periodic follow-up imaging was 96.1%. Overall hearing preservation rate was 76.5%. Linear accelerator-based stereotactic radiosurgery offers a safe and effective treatment for patients with vestibular schwannoma by providing high local control rates along with improved quality of life through well-preserved hearing function.

  12. Changes in resting-state fMRI in vestibular neuritis.

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  14. [Vertigo and falls in the elderly. Part 1: epidemiology, pathophysiology, vestibular diagnostics and risk of falling].

    Science.gov (United States)

    Walther, L E; Nikolaus, T; Schaaf, H; Hörmann, K

    2008-08-01

    Disorders of the equilibrium function in the elderly will increase in the coming years due to demographic changes in Germany. In addition to a reduction in the quality of life of affected patients, the risk of suffering from a fall increases with age. At the morphological level age-specific changes of the peripheral vestibular structures, somatosensory pathways and vision can be found, such as degenerative alterations, reduced number of cells and receptors and an accumulation of lipofuscin. Disorders of the equilibrium function in old age are individual-specific, complex procedures which develop from age-related physiological, degenerative alterations in the components of the sensomotor system which maintain equilibrium and can come into being together with vestibular and non-vestibular accompanying diseases as well as psychological factors.

  15. Place of Gamma Knife Stereotactic Radiosurgery in Grade 4 Vestibular Schwannoma Based on Case Series of 86 Patients with Long-Term Follow-Up.

    Science.gov (United States)

    Lefranc, Michel; Da Roz, Leila Maria; Balossier, Anne; Thomassin, Jean Marc; Roche, Pierre Hugue; Regis, Jean

    2018-06-01

    Grade IV vestibular schwannoma (Koos classification) is generally considered to be an indication for microsurgical resection or combined radiosurgery-microsurgery. However, the place of Gamma Knife stereotactic surgery (GK-SRS), either as first-line treatment or when progression of residual tumor compresses the brainstem, has not been clearly evaluated. This article reports the results of a large case series of patients with grade 4 vestibular schwannoma treated by GK-SRS. All consecutive patients with grade IV vestibular schwannoma treated by GK-SRS in our department between 1996 and 2011 with a minimum follow-up of 3 years were included in this study. 86 patients were treated by GK-SRS with a minimum follow-up of 3 years. Mean follow-up was 6.2 years (3-16 years). The mean age of the patients at the time of GK-SRS was 54.6 years (range: 23-84) and the sex ratio was 0.6. At the time of radiosurgery, no patient presented brainstem dysfunction prior to GK-SRS. 38 patients had functional hearing before treatment. One patient presented mild trigeminal neuralgia before GK-SRS. Tumor control with no clinical deterioration was obtained in 78 patients (90.7%). No radiation-induced brainstem or cranial nerve toxicity was observed in any of these patients. Functional hearing was maintained in 25 patients. 8 (9.3%) patients presented tumor growth and required microsurgical resection in 7 cases and ventricular shunt in 1 case. On the basis of this large series, GK-SRS appears to be a safe and effective treatment option for grade IV vestibular schwannoma for patients with no signs of brainstem dysfunction. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Simultaneous measurements of work function and H‒ density including caesiation of a converter surface

    Science.gov (United States)

    Cristofaro, S.; Friedl, R.; Fantz, U.

    2017-08-01

    Negative hydrogen ion sources rely on the surface conversion of neutral atomic hydrogen and positive hydrogen ions to H-. The efficiency of this process depends on the actual work function of the converter surface. By introducing caesium into the source the work function decreases, enhancing the negative ion yield. In order to study the impact of the work function on the H- surface production at similar conditions to the ones in ion sources for fusion devices like ITER and DEMO, fundamental investigations are performed in a flexible laboratory experiment. The work function of the converter surface can be absolutely measured by photoelectric effect, while a newly installed cavity ring-down spectroscopy system (CRDS) measures the H- density. The CRDS is firstly tested and characterized by investigations on H- volume production. Caesiation of a stainless steel sample is then performed in vacuum and the plasma effect on the Cs layer is investigated also for long plasma-on times. A minimum work function of (1.9±0.1) eV is reached after some minutes of plasma treatment, resulting in a reduction by a value of 0.8 eV compared to vacuum measurements. The H- density above the surface is (2.1±0.5)×1015 m-3. With further plasma exposure of the caesiated surface, the work function increases up to 3.75 eV, due to the impinging plasma particles which gradually remove the Cs layer. As a result, the H- density decreases by a factor of at least 2.

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

    Science.gov (United States)

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

    2018-01-01

    "auditory and vestibular system development and function" terms. We also found 108 genes showing tonotopic gene expression in the cochlear ENHCs. Conclusions : We have predicted the main pathways and molecular networks for ENHCs in the organ of Corti and vestibular neuroepithelium. These pathways will facilitate the design of molecular maps to select novel candidate genes for hearing or vestibular loss to conduct functional studies.

  18. Avaliação vestibular em mulheres com disfunção temporomandibular Vestibular evaluation in women with temporomandibular dysfunction

    Directory of Open Access Journals (Sweden)

    Bianca Simone Zeigelboim

    2007-06-01

    Full Text Available OBJETIVO: avaliar o comportamento vestibular em pacientes com disfunção temporomandibular. MÉTODOS: avaliaram-se 27 pacientes do sexo feminino, na faixa etária de 30 a 53 anos, encaminhadas do Centro de Diagnóstico e Tratamento da Articulação Temporomandibular para o Laboratório de Otoneurologia da Universidade Tuiuti do Paraná. Realizaram-se os seguintes procedimentos: anamnese, inspeção otológica e avaliação vestibular por meio da vectoeletronistagmografia. RESULTADOS: as queixas mais freqüentes foram: dificuldade ou dor ao movimento do pescoço (77,7%, dor irradiada para ombro/braço (77,7%, zumbido e formigamento de extremidade superior (77,7%, tontura e dor de cabeça (66,6%, ansiedade (55,5%, sensação de cabeça oca (51,8%, agitação durante o sono (51,8% e depressão (51,8%. O exame vestibular esteve alterado em 20 pacientes (74,0% na prova calórica. Houve freqüência de alteração no sistema vestibular periférico. Houve predomínio das síndromes vestibulares periféricas deficitárias. CONCLUSÃO: ressalta-se a importância de se estudar a relação do sistema vestibular com a disfunção temporomandibular uma vez que observamos, na presente pesquisa, um número elevado de alteração no exame labiríntico.PURPOSE: to evaluate the vestibular functioning in patients with temporomandibular joint dysfunction. METHODS: 27 female patients were evaluated, with age varying from 30 to 53-year-old, referred from the Centre of Diagnosis and Treatment of Temporomandibular Joint Dysfunction to the Otoneurological Laboratory of Tuiuti University of Paraná. The following exams were carried out: anamnesis, otoscopy and vestibular evaluations through vectoelectronystagmography. RESULTS: the most frequent complaints were: difficulty or pain with movement of the neck (77.7%, pain irradiated to the shoulder/arm (77.7%, tinnitus and paresthesia of superior extremities (77.7% in each one, dizziness and headaches (66,6%, anxiety (55

  19. Hearing loss in enlarged vestibular aqueduct and incomplete partition type II.

    Science.gov (United States)

    Ahadizadeh, Emily; Ascha, Mustafa; Manzoor, Nauman; Gupta, Amit; Semaan, Maroun; Megerian, Cliff; Otteson, Todd

    The purpose of this work is to identify the role of incomplete partition type II on hearing loss among patients with enlarged vestibular aqueduct (EVA). EVA is a common congenital inner ear malformation among children with hearing loss, where vestibular aqueduct morphology in this population has been shown to correlate to hearing loss. However, the impact of incomplete partition between cochlear turns on hearing loss has not been, despite meaningful implications for EVA pathophysiology. A retrospective review of radiology reports for patients who had computed tomography (CT) scans with diagnoses of hearing loss at a tertiary medical center between January 2000 and June 2016 were screened for EVA. CT scans of the internal auditory canal (IAC) for those patients with EVA were examined for evidence of incomplete partition type II (IP-II), measurements of midpoint width and operculum width a second time, and patients meeting Cincinnati criteria for EVA selected for analysis. Statistical analysis including chi-square, Wilcoxon rank-sum, and t-tests were used to identify differences in outcomes and clinical predictors, as appropriate for the distribution of the data. Linear mixed models of hearing test results for all available tests were constructed, both univariable and adjusting for vestibular aqueduct morphometric features, with ear-specific intercepts and slopes over time. There were no statistically significant differences in any hearing test results or vestibular aqueduct midpoint and operculum widths. Linear mixed models, both univariable and those adjusting for midpoint and operculum widths, did not indicate a statistically significant effect of incomplete partition type II on hearing test results. Hearing loss due to enlarged vestibular aqueduct does not appear to be affected by the presence of incomplete partition type II. Our results suggest that the pathophysiological processes underlying hearing loss in enlarged vestibular aqueduct may not be a result of

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Valentina Dilda

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  3. Effectiveness of Otolith Repositioning Maneuvers and Vestibular Rehabilitation exercises in elderly people with Benign Paroxysmal Positional Vertigo: a systematic review.

    Science.gov (United States)

    Ribeiro, Karyna Figueiredo; Oliveira, Bruna Steffeni; Freitas, Raysa V; Ferreira, Lidiane M; Deshpande, Nandini; Guerra, Ricardo O

    2017-06-29

    Benign Paroxysmal Positional Vertigo is highly prevalent in elderly people. This condition is related to vertigo, hearing loss, tinnitus, poor balance, gait disturbance, and an increase in risk of falls, leading to postural changes and quality of life decreasing. To evaluate the outcomes obtained by clinical trials on the effectiveness of Otolith Repositioning Maneuver and Vestibular Rehabilitation exercises in the treatment of Benign Paroxysmal Positional Vertigo in elderly. The literature research was performed using PubMed, Scopus, Web of Science and PEDro databases, and included randomized controlled clinical trials in English, Spanish and Portuguese, published during January 2000 to August 2016. The methodological quality of the studies was assessed by PEDro score and the outcomes analysis was done by critical revision of content. Six studies were fully reviewed. The average age of participants ranged between 67.2 and 74.5 years. The articles were classified from 2 to 7/10 through the PEDro score. The main outcome measures analyzed were vertigo, positional nystagmus and postural balance. Additionally, the number of maneuvers necessary for remission of the symptoms, the quality of life, and the functionality were also assessed. The majority of the clinical trials used Otolith Repositioning Maneuver (n=5) and 3 articles performed Vestibular Rehabilitation exercises in addition to Otolith Repositioning Maneuver or pharmacotherapy. One study showed that the addition of movement restrictions after maneuver did not influence the outcomes. There was a trend of improvement in Benign Paroxysmal Positional Vertigo symptomatology in elderly patients who underwent Otolith Repositioning Maneuver. There is sparse evidence from methodologically robust clinical trials that examined the effects of Otolith Repositioning Maneuver and Vestibular Rehabilitation exercises for treating Benign Paroxysmal Positional Vertigo in the elderly. Randomized controlled clinical trials with

  4. Effectiveness of Otolith Repositioning Maneuvers and Vestibular Rehabilitation exercises in elderly people with Benign Paroxysmal Positional Vertigo: a systematic review

    Directory of Open Access Journals (Sweden)

    Karyna Figueiredo Ribeiro

    Full Text Available Abstract Introduction Benign Paroxysmal Positional Vertigo is highly prevalent in elderly people. This condition is related to vertigo, hearing loss, tinnitus, poor balance, gait disturbance, and an increase in risk of falls, leading to postural changes and quality of life decreasing. Objective To evaluate the outcomes obtained by clinical trials on the effectiveness of Otolith Repositioning Maneuver and Vestibular Rehabilitation exercises in the treatment of Benign Paroxysmal Positional Vertigo in elderly. Methods The literature research was performed using PubMed, Scopus, Web of Science and PEDro databases, and included randomized controlled clinical trials in English, Spanish and Portuguese, published during January 2000 to August 2016. The methodological quality of the studies was assessed by PEDro score and the outcomes analysis was done by critical revision of content. Results Six studies were fully reviewed. The average age of participants ranged between 67.2 and 74.5 years. The articles were classified from 2 to 7/10 through the PEDro score. The main outcome measures analyzed were vertigo, positional nystagmus and postural balance. Additionally, the number of maneuvers necessary for remission of the symptoms, the quality of life, and the functionality were also assessed. The majority of the clinical trials used Otolith Repositioning Maneuver (n = 5 and 3 articles performed Vestibular Rehabilitation exercises in addition to Otolith Repositioning Maneuver or pharmacotherapy. One study showed that the addition of movement restrictions after maneuver did not influence the outcomes. Conclusion There was a trend of improvement in Benign Paroxysmal Positional Vertigo symptomatology in elderly patients who underwent Otolith Repositioning Maneuver. There is sparse evidence from methodologically robust clinical trials that examined the effects of Otolith Repositioning Maneuver and Vestibular Rehabilitation exercises for treating Benign Paroxysmal

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

    Science.gov (United States)

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

    2018-06-01

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

  6. Vestibular-Evoked Myogenic Potentials in Bilateral Vestibulopathy

    Directory of Open Access Journals (Sweden)

    Sally M. Rosengren

    2018-04-01

    Full Text Available Bilateral vestibulopathy (BVP is a chronic condition in which patients have a reduction or absence of vestibular function in both ears. BVP is characterized by bilateral reduction of horizontal canal responses; however, there is increasing evidence that otolith function can also be affected. Cervical and ocular vestibular-evoked myogenic potentials (cVEMPs/oVEMPs are relatively new tests of otolith function that can be used to test the saccule and utricle of both ears independently. Studies to date show that cVEMPs and oVEMPs are often small or absent in BVP but are in the normal range in a significant proportion of patients. The variability in otolith function is partly due to the heterogeneous nature of BVP but is also due to false negative and positive responses that occur because of the large range of normal VEMP amplitudes. Due to their variability, VEMPs are not part of the diagnosis of BVP; however, they are helpful complementary tests that can provide information about the extent of disease within the labyrinth. This article is a review of the use of VEMPs in BVP, summarizing the available data on VEMP abnormalities in patients and discussing the limitations of VEMPs in diagnosing bilateral loss of otolith function.

  7. Interactive Healthcare Systems in the Home: Vestibular Rehabilitation

    DEFF Research Database (Denmark)

    Aarhus, Rikke; Grönvall, Erik; Larsen, Simon Bo

    2010-01-01

    Vestibular dysfunction is a balance disorder, causing dizziness that provokes discomfort and fall situations. This paper discusses early results from a project that aims to develop assistive technologies to support home-based rehabilitation for elderly affected by Vestibular dysfunction.......Vestibular dysfunction is a balance disorder, causing dizziness that provokes discomfort and fall situations. This paper discusses early results from a project that aims to develop assistive technologies to support home-based rehabilitation for elderly affected by Vestibular dysfunction....

  8. Age-Related Neurochemical Changes in the Vestibular Nuclei

    Directory of Open Access Journals (Sweden)

    Paul eSmith

    2016-03-01

    Full Text Available There is evidence that the normal aging process is associated with impaired vestibulo-ocular (VOR and vestibulo-spinal reflexes, causing reduced visual acuity and postural instability. Nonetheless, the available evidence is not entirely consistent, especially with respect to the VOR. Some recent studies have reported that VOR gain can be intact even above 80 years of age. Similarly, although there is evidence for age-related hair cell loss and neuronal loss in Scarpa’s ganglion and the vestibular nucleus complex (VNC, it is not entirely consistent. Whatever structural and functional changes occur in the VNC as a result of aging, either to cause vestibular impairment or to compensate for it, neurochemical changes must underlie them. However, the neurochemical changes that occur in the VNC with aging are poorly understood because the available literature is very limited. This review summarises and critically evaluates the available evidence relating to the noradrenaline, serotonin, dopamine, glutamate, GABA, glycine, and nitric oxide neurotransmitter systems in the aging VNC. It is concluded that, at present, it is difficult, if not impossible, to relate the neurochemical changes observed to the function of specific VNC neurons and whether the observed changes are the cause of a functional deficit in the VNC or an effect of it. A better understanding of the neurochemical changes that occur during aging may be important for the development of potential drug treatments for age-related vestibular disorders. However, this will require the use of more sophisticated methodology such as in vivo microdialysis with single neuron recording and perhaps new technologies such as optogenetics.

  9. Age-Related Neurochemical Changes in the Vestibular Nuclei.

    Science.gov (United States)

    Smith, Paul F

    2016-01-01

    There is evidence that the normal aging process is associated with impaired vestibulo-ocular reflexes (VOR) and vestibulo-spinal reflexes, causing reduced visual acuity and postural instability. Nonetheless, the available evidence is not entirely consistent, especially with respect to the VOR. Some recent studies have reported that VOR gain can be intact even above 80 years of age. Similarly, although there is evidence for age-related hair cell loss and neuronal loss in Scarpa's ganglion and the vestibular nucleus complex (VNC), it is not entirely consistent. Whatever structural and functional changes occur in the VNC as a result of aging, either to cause vestibular impairment or to compensate for it, neurochemical changes must underlie them. However, the neurochemical changes that occur in the VNC with aging are poorly understood because the available literature is very limited. This review summarizes and critically evaluates the available evidence relating to the noradrenaline, serotonin, dopamine, glutamate, GABA, glycine, and nitric oxide neurotransmitter systems in the aging VNC. It is concluded that, at present, it is difficult, if not impossible, to relate the neurochemical changes observed to the function of specific VNC neurons and whether the observed changes are the cause of a functional deficit in the VNC or an effect of it. A better understanding of the neurochemical changes that occur during aging may be important for the development of potential drug treatments for age-related vestibular disorders. However, this will require the use of more sophisticated methodology such as in vivo microdialysis with single neuron recording and perhaps new technologies such as optogenetics.

  10. Vestibular Schwannoma or acoustic neuroma

    Directory of Open Access Journals (Sweden)

    Hekmatara M

    1997-04-01

    Full Text Available Vestibular schwannoma is the most common tumor of the posterior fossa of the skull. Patients referred with the primary otologic symptoms such as hearing loss, tinnitus, vertigo, imbalance, and the cranial nerve palsy. Thirty-three patients were operated and treated by a team of otolaryngologist and neurosurgeon, anudiometrist, and internist. Patients'chiefcomplaint was due to 94% hearing loss and 27% tinnitus. They scarcely complain of vertigo. If a patient refers with the palsy or paralysis of facial nerve preoperation, we must think of the facial nerve schwannoma or hemangioma or congential cholestoma or malignant metastases rather than acoustic neuroma. The best way for preoperative diagnosis is audiometry, ABR (Auditory Brain Response, and SDS (speech discrimination score with 90% success, but computer Tomography (CT scan and MRI (Magnetic Resonance Image are the valuable anatomic diagnostic radiographic devices. The best method of operation is translabirynthine approach (TLA, since it has the advantages such as an easy access to nerve paths and being the nearest path to CPA (Cerebellopontine Angle. Physicians ought to talk to patients about the importance of the microscopic surgery, surgical methods, and their probable diverse effects such as hearing loss, facial nerve palsy, and intracranial problems.

  11. Dynamical density functional theory for arbitrary-shape colloidal fluids including inertia and hydrodynamic interactions

    Science.gov (United States)

    Duran-Olivencia, Miguel A.; Goddard, Ben; Kalliadasis, Serafim

    2015-11-01

    Over the last few decades the classical density-functional theory (DFT) and its dynamic extensions (DDFTs) have become a remarkably powerful tool in the study of colloidal fluids. Recently there has been extensive research to generalise all previous DDFTs finally yielding a general DDFT equation (for spherical particles) which takes into account both inertia and hydrodynamic interactions (HI) which strongly influence non-equilibrium properties. The present work will be devoted to a further generalisation of such a framework to systems of anisotropic particles. To this end, the kinetic equation for the Brownian particle distribution function is derived starting from the Liouville equation and making use of Zwanzig's projection-operator techniques. By averaging over all but one particle, a DDFT equation is finally obtained with some similarities to that for spherical colloids. However, there is now an inevitable translational-rotational coupling which affects the diffusivity of asymmetric particles. Lastly, in the overdamped (high friction) limit the theory is notably simplified leading to a DDFT equation which agrees with previous derivations. We acknowledge financial support from European Research Council via Advanced Grant No. 247031.

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

    Science.gov (United States)

    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

  13. Vestibular apparatus disorders after external radiation therapy for head and neck cancers

    International Nuclear Information System (INIS)

    Gabriele, P.; Orecchia, R.; Sannazzari, G.L.; Magnano, M.; Albera, R.

    1992-01-01

    External irradiation of different head and neck cancers may involve parts of the ear. The vestibular function of 25 patients in which the inner ear was comprised in the irradiated volume was investigated by electronystagmography (ENG). Doses administered (3/5 with vertigo) showed vestibular abnormalities to ENG (44% of the total). Altered responses to specific test were as follows : 6 patients to the bithermal caloric stimulation, to pendular-sinusoidal 2, and the other 3 to both of them. Patients were evaluated 3 and 6 months after ending of the radiation therapy course. At the 1st evaluation, abnormalities to caloric test were noted in 3 patients (12%) and to sinusoidal rotary test in 1 patient (4%). At the second rates of abnormal response increased to 36 and 20% respectively. Vestibular disorders seemed to be scantely related to total radiation dose. Data of literature are discussed in order to identify possible implications on treatment planning. (author). 33 refs., 3 tabs

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

    Science.gov (United States)

    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.

  15. Origin of vestibular dysfunction in Usher syndrome type 1B.

    NARCIS (Netherlands)

    Sun, J.; Alphen, A.M. van; Wagenaar, M.; Huygen, P.L.M.; Hoogenraad, C.C.; Hasson, T.; Koekkoek, S.K.; Bohne, B.A.; Zeeuw, C.I. de

    2001-01-01

    It is still debated to what extent the vestibular deficits in Usher patients are due to either central vestibulocerebellar or peripheral vestibular problems. Here, we determined the origin of the vestibular symptoms in Usher 1B patients by subjecting them to compensatory eye movement tests and by

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

    Science.gov (United States)

    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

  17. Pulmonary alveolar microlithiasis. A review including ultrastructural and pulmonary function studies

    International Nuclear Information System (INIS)

    Prakash, U.B.; Barham, S.S.; Rosenow, E.C.; Brown, M.L.; Payne, W.S.

    1983-01-01

    Pulmonary alveolar microlithiasis is a rare disease of unknown cause in which calcium phosphate microliths are deposited throughout the lungs. These deposits are of sufficient density to be almost diagnostic on chest roentgenograms. The Mayo Clinic experience with 8 patients is added to the approximately 120 cases reported in the world literature. The age range of all patients is from newborn to 80 years, with a mean age at diagnosis of about 35 years. No sexual predominance has been noted, but in about half of the reported cases a familial pattern has been found. The progression of the disease is generally very slow, some patients having been followed up for more than 30 years without evidence of change. No specific treatment is available. Pulmonary function studies demonstrate a tendency toward a restrictive pattern. Technetium-99m scanning and scanning and transmission electron microscopy are useful procedures for analysis of pulmonary alveolar microliths

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

    Science.gov (United States)

    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

  19. Inflation including collapse of the wave function: the quasi-de Sitter case

    Energy Technology Data Exchange (ETDEWEB)

    Leon, Gabriel [Universidad de Buenos Aires, Ciudad Universitaria-PabI, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina); Landau, Susana J. [Universidad de Buenos Aires y IFIBA, CONICET, Ciudad Universitaria-PabI, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina); Piccirilli, Maria Pia [Universidad Nacional de La Plata, Grupo de Astrofisica, Relatividad y Cosmologia, Facultad de Ciencias Astronomicas y Geofisicas, Pcia de Buenos Aires (Argentina)

    2015-08-15

    The precise physical mechanism describing the emergence of the seeds of cosmic structure from a perfect isotropic and homogeneous universe has not been fully explained by the standard version of inflationary models. To handle this shortcoming, D. Sudarsky and collaborators have developed a proposal: the self-induced collapse hypothesis. In this scheme, the objective collapse of the inflaton wave function is responsible for the emergence of inhomogeneity and anisotropy at all scales. In previous papers, the proposal was developed with an almost exact de Sitter space-time approximation for the background that led to a perfect scale-invariant power spectrum. In the present article, we consider a full quasi-de Sitter expansion and calculate the primordial power spectrum for three different choices of the self-induced collapse. The consideration of a quasi-de Sitter background allows us to distinguish departures from an exact scale-invariant power spectrum that are due to the inclusion of the collapse hypothesis. These deviations are also different from the prediction of standard inflationary models with a running spectral index. A comparison with the primordial power spectrum and the CMB temperature fluctuation spectrum preferred by the latest observational data is also discussed. From the analysis performed in this work, it follows that most of the collapse schemes analyzed in this paper are viable candidates to explain the present observations of the CMB fluctuation spectrum. (orig.)

  20. Inflation including collapse of the wave function: the quasi-de Sitter case

    International Nuclear Information System (INIS)

    Leon, Gabriel; Landau, Susana J.; Piccirilli, Maria Pia

    2015-01-01

    The precise physical mechanism describing the emergence of the seeds of cosmic structure from a perfect isotropic and homogeneous universe has not been fully explained by the standard version of inflationary models. To handle this shortcoming, D. Sudarsky and collaborators have developed a proposal: the self-induced collapse hypothesis. In this scheme, the objective collapse of the inflaton wave function is responsible for the emergence of inhomogeneity and anisotropy at all scales. In previous papers, the proposal was developed with an almost exact de Sitter space-time approximation for the background that led to a perfect scale-invariant power spectrum. In the present article, we consider a full quasi-de Sitter expansion and calculate the primordial power spectrum for three different choices of the self-induced collapse. The consideration of a quasi-de Sitter background allows us to distinguish departures from an exact scale-invariant power spectrum that are due to the inclusion of the collapse hypothesis. These deviations are also different from the prediction of standard inflationary models with a running spectral index. A comparison with the primordial power spectrum and the CMB temperature fluctuation spectrum preferred by the latest observational data is also discussed. From the analysis performed in this work, it follows that most of the collapse schemes analyzed in this paper are viable candidates to explain the present observations of the CMB fluctuation spectrum. (orig.)

  1. The Skull Vibration-Induced Nystagmus Test of Vestibular Function—A Review

    Science.gov (United States)

    Dumas, Georges; Curthoys, Ian S.; Lion, Alexis; Perrin, Philippe; Schmerber, Sébastien

    2017-01-01

    A 100-Hz bone-conducted vibration applied to either mastoid induces instantaneously a predominantly horizontal nystagmus, with quick phases beating away from the affected side in patients with a unilateral vestibular loss (UVL). The same stimulus in healthy asymptomatic subjects has little or no effect. This is skull vibration-induced nystagmus (SVIN), and it is a useful, simple, non-invasive, robust indicator of asymmetry of vestibular function and the side of the vestibular loss. The nystagmus is precisely stimulus-locked: it starts with stimulation onset and stops at stimulation offset, with no post-stimulation reversal. It is sustained during long stimulus durations; it is reproducible; it beats in the same direction irrespective of which mastoid is stimulated; it shows little or no habituation; and it is permanent—even well-compensated UVL patients show SVIN. A SVIN is observed under Frenzel goggles or videonystagmoscopy and recorded under videonystagmography in absence of visual-fixation and strong sedative drugs. Stimulus frequency, location, and intensity modify the results, and a large variability in skull morphology between people can modify the stimulus. SVIN to 100 Hz mastoid stimulation is a robust response. We describe the optimum method of stimulation on the basis of the literature data and testing more than 18,500 patients. Recent neural evidence clarifies which vestibular receptors are stimulated, how they cause the nystagmus, and why the same vibration in patients with semicircular canal dehiscence (SCD) causes a nystagmus beating toward the affected ear. This review focuses not only on the optimal parameters of the stimulus and response of UVL and SCD patients but also shows how other vestibular dysfunctions affect SVIN. We conclude that the presence of SVIN is a useful indicator of the asymmetry of vestibular function between the two ears, but in order to identify which is the affected ear, other information and careful clinical judgment are

  2. Role of CYP2E1-mediated metabolism in the acute and vestibular toxicities of nineteen nitriles in the mouse.

    Science.gov (United States)

    Saldaña-Ruíz, Sandra; Soler-Martín, Carla; Llorens, Jordi

    2012-01-25

    Allylnitrile, cis-crotononitrile, and 3,3'-iminodipropionitrile are known to cause vestibular toxicity in rodents, and evidence is available indicating that cis-2-pentenenitrile shares this effect. We evaluated nineteen nitriles for vestibular toxicity in wild type (129S1) and CYP2E1-null mice, including all the above, several neurotoxic nitriles, and structurally similar nitriles. A new acute toxicity test protocol was developed to facilitate evaluation of the vestibular toxicity by a specific behavioral test battery at doses up to sub-lethal levels while using a limited number of animals. A mean number of 8.5±0.3 animals per nitrile, strain and sex was necessary to obtain evidence of vestibular toxicity and optionally an estimation of the lethal dose. For several but not all nitriles, lethal doses significantly increased in CYP2E1-null mice. The protocol revealed the vestibular toxicity of five nitriles, including previously identified ototoxic compounds and one nitrile (trans-crotononitrile) known to have a different profile of neurotoxic effects in the rat. In all five cases, both sexes were affected and no decrease in susceptibility was apparent in CYP2E1-null mice respect to 129S1 mice. Fourteen nitriles caused no vestibular toxicity, including six nitriles tested in CYP2E1-null mice at doses significantly larger than the maximal doses that can be tested in wild type animals. We conclude that only a subset of low molecular weight nitriles is toxic to the vestibular system, that species-dependent differences exist in this vestibular toxicity, and that CYP2E1-mediated metabolism is not involved in this effect of nitriles although it has a role in the acute lethality of some of these compounds. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  3. Structural and functional effects of heavy metals on the nervous system, including sense organs, of fish

    DEFF Research Database (Denmark)

    Baatrup, E

    1991-01-01

    metals are well known pollutants in the aquatic environment. Their interaction with relevant chemical stimuli may interfere with the communication between fish and environment. 5. The affinity for a number of ligands and macromolecules makes heavy metals most potent neurotoxins. 6. The present Mini......1. Today, fish in the environment are inevitably exposed to chemical pollution. Although most hazardous substances are present at concentrations far below the lethal level, they may still cause serious damage to the life processes of these animals. 2. Fish depend on an intact nervous system......, including their sense organs, for mediating relevant behaviour such as food search, predator recognition, communication and orientation. 3. Unfortunately, the nervous system is most vulnerable and injuries to its elements may dramatically change the behaviour and consequently the survival of fish. 4. Heavy...

  4. Indications of Gamma knife radiosurgery for vestibular schwannomas

    International Nuclear Information System (INIS)

    Fukuoka, Seiji; Takanashi, Masami; Hojyo, Atsufumi; Tanaka, Chiharu; Konishi, Masanori; Nakamura, Hirohiko

    2007-01-01

    The purpose of this study was to investigate the indication of gamma knife radiosurgery for vestibular schwannomas by analyzing tumor control and possible complications using low marginal doses and conformal multiple shots to fit irregular tumor shapes. The authors evaluated 223 patients with followed-up periods ranging from 5 years to 15 years (mean 7.7 years, median 7.4 years). Marginal doses were 9 to 15 Gy (mean 12.5 Gy, median 12 Gy) with corresponding treatment volumes being between 0.1 and 18.7 cm 3 (mean 2.6 cm 3 , median 1.8 cm 3 ). The number of isocenters varied from 2 to 24 shots (mean 9, median 9.2). The actuarial tumor control rates were 95% at 5 years and 94% at 7 years, respectively. Larger tumors (p=0.0068) and those in younger patients (p=0.093) tended to recur significantly. The preservation rates of useful hearing were 84%, 71%, and 64% at 2, 4, and 7 years, respectively. The most deterioration seemed to occur in cases with elderly patients (p=0.0048). Facial and trigeminal functions were preserved at 100%, and 97.8%, respectively. Amongst all patients, 20.6% developed transient dizziness, with persistent dizziness remaining in 1.5% of the total. Fifty-six other patients not in the long-term evaluation consecutively underwent caloric testing and static stabilometry as well as neurological examinations to evaluate vestibular function in detail, both before and after gamma knife radiosurgery (GKRS). The results showed that 90% of the patients had already developed vestibular dysfunction before the treatment despite reported symptoms of dizziness. GKRS did not significantly affect vestibular function. Hydrocephalus was recognized in 5.5% of all patients, and seemed to occur primarily in cases with larger tumors (p=0.0189). GKRS provides a safe and effective therapy for small to medium sized tumors up to 8 cm 3 . Long-term hearing preservation rate may be affected by presbycusis in elderly patients. (author)

  5. INFLUENCE OF DANCE TRAINING ON SACCULOCOLLIC PATHWAY: VESTIBULAR EVOKED MYOGENIC POTENTIALS (VEMP) AS AN OBJECTIVE TOOL

    OpenAIRE

    Swathi; Sathish Kumar

    2013-01-01

    ABSTRACT : Auditory system is shaped by experience and training. Training (s ensory experience) induces neurophysiologic changes & plasticity in normal hearing individuals, hearing loss patients, hearing aid users and cochlear implanted subjects. Not only speech stimulus, but music also brings about functional and structural organi zation of the brain in musician compared to non - musicians. The Vestibular evoked myogenic potentials (VEMP) are a biphasic in...

  6. Bayesian quantification of sensory reweighting in a familial bilateral vestibular disorder (DFNA9)

    NARCIS (Netherlands)

    Alberts, B.B.G.T.; Selen, L.P.J.; Verhagen, W.I.M.; Pennings, R.J.E.; Medendorp, W.P.

    2018-01-01

    DFNA9 is a rare progressive autosomal dominantly inherited vestibulo-cochlear disorder, resulting in a homogeneous group of patients with hearing impairment and bilateral vestibular function loss. These patients suffer from a deteriorated sense of spatial orientation, leading to balance problems in

  7. Histopathological and ultrastructural analysis of vestibular endorgans in Meniere's disease reveals basement membrane pathology

    Directory of Open Access Journals (Sweden)

    McCall Andrew A

    2009-06-01

    Full Text Available Abstract Background We report the systematic analysis of the ultrastructural and cytological histopathology of vestibular endorgans acquired from labyrinthectomy in Meniere's disease. Methods 17 subjects with intractable Meniere's disease and ipsilateral non-serviceable hearing presenting to the Neurotology Clinic from 1997 to 2006 who chose ablative labyrinthectomy (average age = 62 years; range 29–83 years participated. The average duration of symptoms prior to surgery was 7 years (range 1–20 years. Results Nearly all vestibular endorgans demonstrated varying degrees of degeneration. A monolayer of epithelial cells occurred significantly more frequently in the horizontal cristae (12/13 = 92% (p Conclusion Systematic histopathological analysis of the vestibular endorgans from Meniere's disease demonstrated neuroepithelial degeneration which was highly correlated with an associated BM thickening. Other findings included hair cell and supporting cell microvessicles, increased intercellular clear spaces in the stroma, and endothelial cell vacuolization and stromal perivascular BM thickening.

  8. Economic values of production and functional traits, including residual feed intake, in Finnish milk production.

    Science.gov (United States)

    Hietala, P; Wolfová, M; Wolf, J; Kantanen, J; Juga, J

    2014-02-01

    Improving the feed efficiency of dairy cattle has a substantial effect on the economic efficiency and on the reduction of harmful environmental effects of dairy production through lower feeding costs and emissions from dairy farming. To assess the economic importance of feed efficiency in the breeding goal for dairy cattle, the economic values for the current breeding goal traits and the additional feed efficiency traits for Finnish Ayrshire cattle under production circumstances in 2011 were determined. The derivation of economic values was based on a bioeconomic model in which the profit of the production system was calculated, using the generated steady state herd structure. Considering beef production from dairy farms, 2 marketing strategies for surplus calves were investigated: (A) surplus calves were sold at a young age and (B) surplus calves were fattened on dairy farms. Both marketing strategies were unprofitable when subsidies were not included in the revenues. When subsidies were taken into account, a positive profitability was observed in both marketing strategies. The marginal economic values for residual feed intake (RFI) of breeding heifers and cows were -25.5 and -55.8 €/kg of dry matter per day per cow and year, respectively. The marginal economic value for RFI of animals in fattening was -29.5 €/kg of dry matter per day per cow and year. To compare the economic importance among traits, the standardized economic weight of each trait was calculated as the product of the marginal economic value and the genetic standard deviation; the standardized economic weight expressed as a percentage of the sum of all standardized economic weights was called relative economic weight. When not accounting for subsidies, the highest relative economic weight was found for 305-d milk yield (34% in strategy A and 29% in strategy B), which was followed by protein percentage (13% in strategy A and 11% in strategy B). The third most important traits were calving

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

    Science.gov (United States)

    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.

  10. Role of the medial medullary reticular formation in relaying vestibular signals to the diaphragm and abdominal muscles

    Science.gov (United States)

    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.

  11. Progression of vestibular schawnnoma after GammaKnife radiosurgery: A challenge for microsurgical resection.

    Science.gov (United States)

    Aboukaïs, Rabih; Bonne, Nicolas-Xavier; Touzet, Gustavo; Vincent, Christophe; Reyns, Nicolas; Lejeune, Jean-Paul

    2018-05-01

    We aimed to evaluate the outcome of patients who underwent salvage microsurgery for vestibular schwannoma (VS) that failed primary Gammaknife radiosurgery (GKS). Among the 1098 patients who received GKS for the treatment of VS in our center between January 2004 and December 2012, the follow-up was organized in our institution for 290 patients who lived in our recruitment area. Tumor progression was noted in 23 patients. A salvage microsurgical resection was performed in 11 patients, who were included in our study. Grading of facial function was done according to the House & Brackman scale. The mean age at diagnosis was 50.2 years (19-68 years) and the mean follow-up was 9.4 years (4-13 years). The mean dose was 11.8 Gy (11-12 Gy) and the mean volume was 922 mm3 (208-2500 mm3). The mean period between GKS and diagnosis of tumor progression was 32 months (18-72 months). Concerning salvage microsurgery, complete resection was obtained in 8 patients. Small residual tumor on the facial nerve was deliberately left in 3 patients and no tumor progression was noted with a mean follow-up of 26 months. At last follow-up, facial nerve function was grade 1 in 4 patients, grade 2 in 3 patients, grade 3 in 1 patient and grade 4 in 3 patients. Salvage surgery of recurrent vestibular schwannoma after failed initial GKS remains a good treatment. However, facial nerve preservation is more challenging in this case and small tumor remnant could be sometimes deliberately left. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. 25 CFR 1000.361 - Will the annual review include a review of the Secretary's residual trust functions?

    Science.gov (United States)

    2010-04-01

    ... Evaluations § 1000.361 Will the annual review include a review of the Secretary's residual trust functions... Department official will be notified of the need for corrective action. The review of the Secretary's trust... 25 Indians 2 2010-04-01 2010-04-01 false Will the annual review include a review of the Secretary...

  13. Sensitivity and specificity of the amer dizziness diagnostic scale (adds) for patients with vestibular disorders.

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    Al Saif, Amer; Alsenany, Samira

    2015-01-01

    [Purpose] To investigate the sensitivity and specificity of a newly developed diagnostic tool, the Amer Dizziness Diagnostic Scale (ADDS), to evaluate and differentially diagnose vestibular disorder and to identify the strengths and weaknesses of the scale and its usefulness in clinical practice. [Subjects and Methods] Two hundred subjects of both genders (72 males, 128 females) aged between 18 to 60 (49.5±7.8) who had a history of vertigo and/or dizziness symptoms for this previous two weeks or less were recruited for the study. All subjects were referred by otolaryngologists, neurologists or family physicians in and around Jeddah, Kingdom of Saudi Arabia. On the first clinic visit, all the patients were evaluated once using the ADDS, following which they underwent routine testing of clinical signs and symptoms, audiometry, and a neurological examination, coupled with tests of Vestibulo-Ocular Reflex function, which often serves as the "gold standard" for determining the probability of a vestibular deficit. [Results] The results show that the ADDS strongly correlated with "true-positive" and "true-negative" responses for determining the probability of a vestibular disorder (r =0.95). A stepwise linear regression was conducted and the results indicate that the ADDS was a significant predictor of "true-positive" and "true-negative" responses in vestibular disorders (R(2) =0.90). Approximately 90% of the variability in the vestibular gold standard test was explained by its relationship to the ADDS. Moreover, the ADDS was found to have a sensitivity of 96% and a specificity of 96%. [Conclusion] This study showed that the Amer Dizziness Diagnostic Scale has high sensitivity and specificity and that it can be used as a method of differential diagnosis for patients with vestibular disorders.

  14. 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.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  16. Central vestibular dysfunction in an otorhinolaryngological vestibular unit: incidence and diagnostic strategy.

    Science.gov (United States)

    Mostafa, Badr E; Kahky, Ayman O El; Kader, Hisham M Abdel; Rizk, Michael

    2014-07-01

    Introduction Vertigo can be due to a variety of central and peripheral causes. The relative incidence of central causes is underestimated. This may have an important impact of the patients' management and prognosis. Objective The objective of this work is to determine the incidence of central vestibular disorders in patients presenting to a vestibular unit in a tertiary referral academic center. It also aims at determining the best strategy to increase the diagnostic yield of the patients' visit. Methods This is a prospective observational study on 100 consecutive patients with symptoms suggestive of vestibular dysfunction. All patients completed a structured questionnaire and received bedside and vestibular examination and neuroimaging as required. Results There were 69 women and 31 men. Their ages ranged between 28 and 73 (mean 42.48 years). Provisional videonystagmography (VNG) results were: 40% benign paroxysmal positional vertigo (BPPV), 23% suspicious of central causes, 18% undiagnosed, 15% Meniere disease, and 4% vestibular neuronitis. Patients with an unclear diagnosis or central features (41) had magnetic resonance imaging (MRI) and Doppler studies. Combining data from history, VNG, and imaging studies, 23 patients (23%) were diagnosed as having a central vestibular lesion (10 with generalized ischemia/vertebra basilar insufficiency, 4 with multiple sclerosis, 4 with migraine vestibulopathy, 4 with phobic postural vertigo, and 1 with hyperventilation-induced nystagmus). Conclusions Combining a careful history with clinical examination, VNG, MRI, and Doppler studies decreases the number of undiagnosed cases and increases the detection of possible central lesions.

  17. Central Vestibular Dysfunction in an Otorhinolaryngological Vestibular Unit: Incidence and Diagnostic Strategy

    Directory of Open Access Journals (Sweden)

    Mostafa, Badr E.

    2014-03-01

    Full Text Available Introduction Vertigo can be due to a variety of central and peripheral causes. The relative incidence of central causes is underestimated. This may have an important impact of the patients' management and prognosis. Objective The objective of this work is to determine the incidence of central vestibular disorders in patients presenting to a vestibular unit in a tertiary referral academic center. It also aims at determining the best strategy to increase the diagnostic yield of the patients' visit. Methods This is a prospective observational study on 100 consecutive patients with symptoms suggestive of vestibular dysfunction. All patients completed a structured questionnaire and received bedside and vestibular examination and neuroimaging as required. Results There were 69 women and 31 men. Their ages ranged between 28 and 73 (mean 42.48 years. Provisional videonystagmography (VNG results were: 40% benign paroxysmal positional vertigo (BPPV, 23% suspicious of central causes, 18% undiagnosed, 15% Meniere disease, and 4% vestibular neuronitis. Patients with an unclear diagnosis or central features (41 had magnetic resonance imaging (MRI and Doppler studies. Combining data from history, VNG, and imaging studies, 23 patients (23% were diagnosed as having a central vestibular lesion (10 with generalized ischemia/vertebra basilar insufficiency, 4 with multiple sclerosis, 4 with migraine vestibulopathy, 4 with phobic postural vertigo, and 1 with hyperventilation-induced nystagmus. Conclusions Combining a careful history with clinical examination, VNG, MRI, and Doppler studies decreases the number of undiagnosed cases and increases the detection of possible central lesions.

  18. Vestibular migraine: clinical and epidemiological aspects

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    Ligia Oliveira Gonçalves Morganti

    Full Text Available ABSTRACT INTRODUCTION: Vestibular migraine (VM is one of the most often common diagnoses in neurotology, but only recently has been recognized as a disease. OBJECTIVE: To analyze the clinical and epidemiological profile of patients with VM. METHODS: This was a retrospective, observational, and descriptive study, with analysis of patients' records from an outpatient VM clinic. RESULTS: 94.1% of patients were females and 5.9% were males. The mean age was 46.1 years; 65.6% of patients had had headache for a longer period than dizziness. A correlation was detected between VM symptoms and the menstrual period. 61.53% of patients had auditory symptoms, with tinnitus the most common, although tonal audiometry was normal in 68.51%. Vectoelectronystagmography was normal in 67.34%, 10.20% had hyporeflexia, and 22.44% had vestibular hyperreflexia. Electrophysiological assessment showed no abnormalities in most patients. Fasting plasma glucose and glycemic curve were normal in most patients, while the insulin curve was abnormal in 75%. 82% of individuals with MV showed abnormalities on the metabolism of carbohydrates. CONCLUSION: VM affects predominantly middle-aged women, with migraine headache representing the first symptom, several years before vertigo. Physical, auditory, and vestibular evaluations are usually normal. The most frequent vestibular abnormality was hyperreflexia. Most individuals showed abnormality related to carbohydrate metabolism.

  19. CONTRIBUTION OF THE AUDIOLOGICAL AND VESTIBULAR ASSESSMENT TO THE DIFFERENTIAL AND ETIOLOGICAL DIAGNOSIS OF PERIPHERIC VESTIBULAR SYNDROMES

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    Loreta Ungureanu

    2012-09-01

    Full Text Available Scope of the study: Vestibular pathology is a complex one, requiring a minute clinical evaluation, as well as numerous paraclinical investigations. The present study analyzes the contribution of the modern methods of vestibular and auditive investigation to the diagnosis of dizziness. Materials and method: The results of the investigations performed on 84 patients with peripheric vestibular syndrome, on whom a complete audiological and vestibular assessment had been also made, have been retrospectively analyzed. Results: Anamnestic data and the results of evaluation permitted classification of peripheric vestibular pathology according to topo-lesional and etiological criteria. The most frequently diagnosed diseases were: benign paroxysmal positional vertigo, Ménière syndrome and vestibular neuronitis. Conclusions: Testing of the vestibulo-ocular and vestibulo-spinal reflexes through videonystagmoscopy and, respectively, computerized dynamic posturography, besides tonal vocal audiometry and precocious auditive potentials, is especially important for a positive diagnosis and etiological differentiation of vestibular syndromes.

  20. [Kinesitherapy in patients with the peripheral vestibular system disorders].

    Science.gov (United States)

    Szczepanik, Marcin; Walak, Jarosław; Woszczak, Marek; Józefowicz-Korczyńska, Magdalena

    2013-01-01

    Kinesitherapy is widely accepted management in patients with vertigo and imbalance, but there has been inadequate evidence that one form of therapy is superior to another. of the study was to compare effectiveness of two kinesitherapy protocols in patients with the peripheral vestibular system disorders. Fifty patients (mean age 46.0±13.1 year) with vertigo and balance instability lasting over 3 months with unilateral vestibular disorder, confirmed in Videnystagmography, were included in the study. Thirty patients underwent supervised and 20 patients home-based exercise programs. All of them were assessed three times at the baseline, after 4 weeks and 3 months, on vertigo intensity and frequency with the Vertigo Syndrome Scale (VSS), Vertigo Visual Analog Scale (VAS) and clinical unsteadiness with tests (Romberg, Amended Motor Club Assesment (AMCA), Eurofit test - standing on one leg. In both groups the clinical tasks and the intensity of vertigo in VAS significantly decreased. The mean value of VSS (part physical and emotional)score significantly decreased only in supervised group at the end of 4 weeks and 3 months (p=ns). Recovery was more dynamic in supervised group than home-based exercises group, in AMCA test (3.9 vs. 1.3 s, p<0.05) in Eurofit tests eye open (14.1 vs. 0.9 s, p<0.05) and eye closed (3.5 vs. 1 s, p<0.05). In patients with unilateral peripheral vestibular dysfunction supervised and home-based group kinesitherapy is an effective treatment method. In supervised group patients recovery has been faster. Copyright © 2013 Polish Otorhinolaryngology - Head and Neck Surgery Society. Published by Elsevier Urban & Partner Sp. z.o.o. All rights reserved.

  1. Differences between otolith- and semicircular canal-activated neural circuitry in the vestibular system.

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    Uchino, Yoshio; Kushiro, Keisuke

    2011-12-01

    In the last two decades, we have focused on establishing a reliable technique for focal stimulation of vestibular receptors to evaluate neural connectivity. Here, we summarize the vestibular-related neuronal circuits for the vestibulo-ocular reflex, vestibulocollic reflex, and vestibulospinal reflex arcs. The focal stimulating technique also uncovered some hidden neural mechanisms. In the otolith system, we identified two hidden neural mechanisms that enhance otolith receptor sensitivity. The first is commissural inhibition, which boosts sensitivity by incorporating inputs from bilateral otolith receptors, the existence of which was in contradiction to the classical understanding of the otolith system but was observed in the utricular system. The second mechanism, cross-striolar inhibition, intensifies the sensitivity of inputs from both sides of receptive cells across the striola in a single otolith sensor. This was an entirely novel finding and is typically observed in the saccular system. We discuss the possible functional meaning of commissural and cross-striolar inhibition. Finally, our focal stimulating technique was applied to elucidate the different constructions of axonal projections from each vestibular receptor to the spinal cord. We also discuss the possible function of the unique neural connectivity observed in each vestibular receptor system. Copyright © 2011 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

  2. A predator-prey model with a holling type I functional response including a predator mutual interference

    Science.gov (United States)

    Seo, G.; DeAngelis, D.L.

    2011-01-01

    The most widely used functional response in describing predator-prey relationships is the Holling type II functional response, where per capita predation is a smooth, increasing, and saturating function of prey density. Beddington and DeAngelis modified the Holling type II response to include interference of predators that increases with predator density. Here we introduce a predator-interference term into a Holling type I functional response. We explain the ecological rationale for the response and note that the phase plane configuration of the predator and prey isoclines differs greatly from that of the Beddington-DeAngelis response; for example, in having three possible interior equilibria rather than one. In fact, this new functional response seems to be quite unique. We used analytical and numerical methods to show that the resulting system shows a much richer dynamical behavior than the Beddington-DeAngelis response, or other typically used functional responses. For example, cyclic-fold, saddle-fold, homoclinic saddle connection, and multiple crossing bifurcations can all occur. We then use a smooth approximation to the Holling type I functional response with predator mutual interference to show that these dynamical properties do not result from the lack of smoothness, but rather from subtle differences in the functional responses. ?? 2011 Springer Science+Business Media, LLC.

  3. Risk of Impaired Control of Spacecraft/Associated Systems and Decreased Mobility Due to Vestibular/Sensorimotor Alterations Associated with Space flight

    Science.gov (United States)

    Bloomberg, Jacob J.; Reschke, Millard F.; Clement, Gilles R.; Mulavara, Ajitkumar P.; Taylor, Laura C..

    2015-01-01

    Control of vehicles and other complex systems is a high-level integrative function of the central nervous system (CNS). It requires well-functioning subsystem performance, including good visual acuity, eye-hand coordination, spatial and geographic orientation perception, and cognitive function. Evidence from space flight research demonstrates that the function of each of these subsystems is altered by removing gravity, a fundamental orientation reference, which is sensed by vestibular, proprioceptive, and haptic receptors and used by the CNS for spatial orientation, posture, navigation, and coordination of movements. The available evidence also shows that the degree of alteration of each subsystem depends on a number of crew- and mission-related factors. There is only limited operational evidence that these alterations cause functional impacts on mission-critical vehicle (or complex system) control capabilities. Furthermore, while much of the operational performance data collected during space flight has not been available for independent analysis, those that have been reviewed are somewhat equivocal owing to uncontrolled (and/or unmeasured) environmental and/or engineering factors. Whether this can be improved by further analysis of previously inaccessible operational data or by development of new operational research protocols remains to be seen. The true operational risks will be estimable only after we have filled the knowledge gaps and when we can accurately assess integrated performance in off-nominal operational settings (Paloski et al. 2008). Thus, our current understanding of the Risk of Impaired Control of Spacecraft/Associated Systems and Decreased Mobility Due to Vestibular/Sensorimotor Alterations Associated with Space flight is limited primarily to extrapolation of scientific research findings, and, since there are limited ground-based analogs of the sensorimotor and vestibular changes associated with space flight, observation of their functional

  4. Comparison of Vestibular Evoked Myogenic Potential and Caloric Tests Findings in Noise Induced Hearing Loss-Affected and Healthy Individuals

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    Farinoosh Fakharnia

    2010-06-01

    Full Text Available Background and Aim: Balance disturbance is one of the non-auditory effects of noisy industrial environments that is usually neglected. The aim of the current study was to investigate the effect of occupational noise on vestibular system among workers with noise-induced hearing loss (NIHL, based on both vestibular evoked myogenic potentials (VEMP and caloric tests.Methods: Thirty male workers with noise-induced hearing loss and thirty male matched controls were examined by VEMP and caloric tests. Study parameters included unilateral weakness, p13 and n23 latencies, and p13-n23 amplitude. Caloric test was performed only for 20 patients.Results: No significant difference was observed in unilateral weakness between the two groups. On the other hand, the difference in mean latencies of p13 in the right ear (p=0.003 and left ear (p=0.01 was significant between the two groups. However, the difference in n23 latency was significant only in the right ear (p=0.03. There was no significant difference between groups in p13-n23 amplitude.Conclusion: It seems that pars inferior of vestibule is the susceptible part in individuals with NIHL. In general, abnormal findings in both VEMP and caloric tests were more common compared to functional symptoms such as vertigo, which may be due to central compensation and the symmetry of the disorder.

  5. Effects of Vestibular Rehabilitation on Balance Control in Older People with Chronic Dizziness: A Randomized Clinical Trial.

    Science.gov (United States)

    Ricci, Natalia Aquaroni; Aratani, Mayra Cristina; Caovilla, Heloísa Helena; Ganança, Fernando Freitas

    2016-04-01

    The aim of this study was to compare the effects of vestibular rehabilitation protocols on balance control in elderly with dizziness. This is a randomized clinical trial with 3-mo follow-up period. The sample was composed of 82 older individuals with chronic dizziness from vestibular disorders. The control group was treated according to the Conventional Cawthorne & Cooksey protocol (n = 40), and the experimental group was submitted to a Multimodal Cawthorne & Cooksey protocol (n = 42). Measures included Dynamic Gait Index, fall history, hand grip strength, Time Up-and-Go Test, sit-to-stand test, multidirectional reach, and static balance tests. With the exception of history of falls, Forward Functional Reach, Unipedal Right and Left Leg Eyes Closed, and Sensorial Romberg Eyes Open, all outcomes improved after treatments. Such results persisted at follow-up period, with the exception of the Tandem Eyes Open and the Timed Up-and-Go manual. The between-group differences for Sensorial Romberg Eyes Closed (4.27 secs) and Unipedal Left Leg Eyes Open (4.08 secs) were significant after treatment, favoring the Multimodal protocol. Both protocols resulted in improvement on elderly's balance control, which was maintained during a short-term period. The multimodal protocol presented better performance on specific static balance tests.

  6. Cochleo-vestibular clinical findings among drug resistant Tuberculosis Patients on therapy-a pilot study

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    Ramma Lebogang

    2012-01-01

    Full Text Available Abstracts Background To investigate the Cochleo-vestibular clinical and audiometric findings in Multi and Extreme Drug Resistance(MDR and XDR tuberculosis(TB patients on treatment and make recommendations. Methods A cross-sectional study of adult MDR and XDR-TB patients was conducted in a general hospital in Cape-Town-South-Africa. Ethical approval was secured and all consenting patients administered with pretested and validated questionnaire under the guidance of International Classification of Functioning, Disability and Health(ICF Checklist-version-2.1a. Audiometric evaluation included: Otoscopy, Diagnostic Audiometry and Tympanometry. The data analyses were done with SPSS version 16, Chi-square and StatCalc-7. Results Fifty-three adults, ages 18-60 (mean-33 years comprising 26 males and 27 females participated in the study. Hospital stay duration varied from 1-18 months (mean-6 months and all were on anti-Koch's second line drugs (regimen 2. MDR TB group were 45(85% and XDR 8(15%. Vertigo was the most common vestibular symptoms, 24(45% whereas, tinnitus 23(42% and hearing loss 13(25% were most frequent auditory complaints. Bilateral sensorineural hearing losses of varying degrees were confirmed in 23(47%. There was no association between gender and age with hearing loss [χ2 (P = 0.16, ά = 0.05 and (p = 0.13, ά = 0.05]. Furthermore, MDR and XTR TB groups [20/42 Vs 3/8; Z = 0.46 and P = 0.64], showed no difference in pattern of the hearing losses. Conclusions A multi-disciplinary close surveillance of MDR and XDR TB patients on therapy is imperative. Finally, researches into therapeutic trials on antidotes and potent safer substitutes for aminoglycosides in the management are recommended.

  7. Heat pulse excitability of vestibular hair cells and afferent neurons.

    Science.gov (United States)

    Rabbitt, Richard D; Brichta, Alan M; Tabatabaee, Hessam; Boutros, Peter J; Ahn, JoongHo; Della Santina, Charles C; Poppi, Lauren A; Lim, Rebecca

    2016-08-01

    In the present study we combined electrophysiology with optical heat pulse stimuli to examine thermodynamics of membrane electrical excitability in mammalian vestibular hair cells and afferent neurons. We recorded whole cell currents in mammalian type II vestibular hair cells using an excised preparation (mouse) and action potentials (APs) in afferent neurons in vivo (chinchilla) in response to optical heat pulses applied to the crista (ΔT ≈ 0.25°C per pulse). Afferent spike trains evoked by heat pulse stimuli were diverse and included asynchronous inhibition, asynchronous excitation, and/or phase-locked APs synchronized to each infrared heat pulse. Thermal responses of membrane currents responsible for APs in ganglion neurons were strictly excitatory, with Q10 ≈ 2. In contrast, hair cells responded with a mix of excitatory and inhibitory currents. Excitatory hair cell membrane currents included a thermoelectric capacitive current proportional to the rate of temperature rise (dT/dt) and an inward conduction current driven by ΔT An iberiotoxin-sensitive inhibitory conduction current was also evoked by ΔT, rising in protein biophysics and manipulate cellular excitability. Copyright © 2016 the American Physiological Society.

  8. Vestibular Migraine: Clinical Challenges and Opportunities for Multidisciplinarity

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    Isabel Luzeiro

    2016-01-01

    Full Text Available Migraine and vertigo are two very prevalent conditions in general population. The coexistence of both in the same subject is a significant clinical challenge, since it is not always possible to understand whether they are causally related or associated by chance, requiring different diagnostic and therapeutic approaches. In this review we analyze and summarize the actual knowledge about vestibular migraine (VM, focusing on the new concepts proposed by the International Classification of Headache Disorders 3-beta and by the Bárány Society and also addressing the former concepts, which are still present in clinical practice. We conclude that clinical studies using a multidisciplinary approach are crucial in this field, since different specialists observe the same pathology with different eyes. Clinical presentation of VM is variable in what concerns vestibular symptoms temporal relation with migraine headache, as well as in their accompanying manifestations. Biomarkers, either genomics or functional, and molecular imaging techniques will be helpful to clarify many aspects of the complexity of this entity, helping to define to what extent can VM be considered a separate and independent clinical entity.

  9. Vestibular Migraine: Clinical Challenges and Opportunities for Multidisciplinarity

    Science.gov (United States)

    Luís, Leonel; Gonçalves, Freire; Pavão Martins, Isabel

    2016-01-01

    Migraine and vertigo are two very prevalent conditions in general population. The coexistence of both in the same subject is a significant clinical challenge, since it is not always possible to understand whether they are causally related or associated by chance, requiring different diagnostic and therapeutic approaches. In this review we analyze and summarize the actual knowledge about vestibular migraine (VM), focusing on the new concepts proposed by the International Classification of Headache Disorders 3-beta and by the Bárány Society and also addressing the former concepts, which are still present in clinical practice. We conclude that clinical studies using a multidisciplinary approach are crucial in this field, since different specialists observe the same pathology with different eyes. Clinical presentation of VM is variable in what concerns vestibular symptoms temporal relation with migraine headache, as well as in their accompanying manifestations. Biomarkers, either genomics or functional, and molecular imaging techniques will be helpful to clarify many aspects of the complexity of this entity, helping to define to what extent can VM be considered a separate and independent clinical entity. PMID:28082766

  10. Small vestibular schwannomas presenting with facial nerve palsy.

    Science.gov (United States)

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

    2014-06-01

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

  11. A cross-sectional survey and cross-sectional clinical trial to determine the prevalence and management of eye movement disorders and vestibular dysfunction in post-stroke patients in the sub-acute phase: protocol

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    Andoret Van Wyk

    2016-09-01

    Full Text Available Introduction: Visual impairment, specifically eye movement disorders and vestibular dysfunction may have a negative influence on the functional recovery in post stroke patients. This type of sensory dysfunction may further be associated with poor functional outcome in patients post stroke.Methods: In phase 1 a cross-sectional survey (n = 100 will be conducted to determine the prevalence of eye movement disorders and vestibular dysfunction in patients that sustained a stroke. A cross-sectional clinical trial (n = 60 will be conducted during phase 2 of the study to determine the effect of the combination of vestibular rehabilitation therapy (VRT and visual scanning exercises (VSE (experimental group integrated with task-specific activities compared to the effect of task-specific activities as an intervention (control group on patients that present with eye movement impairment and central vestibular dysfunction post-stroke. An audiologist will assess; (a visual acuity (static and dynamic; (b nystagmus; (c; saccadic eye movements; (d smooth pursuit eye movements; (e vestibulo-ocular reflex; and (f saccular, utricular and vestibular nerve function. An independent physiotherapist will assess; (1 cognitive function; (2 residual oculomotor visual performance; (3 visual-perceptual system; (4 functional balance; (5 a patient’s ability to modify gait in response to changing task demands; (6 functional ability; and (7 presence of anxiety and/or depression and (8 level of participation in physical activity. Ethics and dissemination: Ethics approval has been obtained from the Ethics Committee of the Faculty of Health Sciences at the University of Pretoria (UP (374/2015. The study will be submitted as fulfilment for the PhD degree at UP. Dissemination will include submission to peer-reviewed professional journals and presentation at congresses. Training of rehabilitation team members on the integration of VSE and VRT into task-specific activities in

  12. Vestibular Symptoms in Factory Workers Subjected to Noise for a Long Period

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    G Raghunath

    2012-06-01

    Full Text Available Background: Noise can cause permanent or temporary hearing loss. High levels of noise may stimulate the vestibular system and thereby cause disturbances in the balancing mechanism. Objective: To determine the effect of long-term exposure to occupational noise on the vestibular system. Methods: A dizziness questionnaire was administered to 20 factory workers who were exposed to occupational noise for more than 10 years. The results were compared with 2 control groups. The control group 1 consisted of 20 people who had similar physical activity during work but were not exposed to high level of noise. Control group 2 consisted of 20 students never exposed to hazardous noise. Results: There was significant difference between the experimental group and the 2 control groups in terms of frequency of vestibular symptoms. However, most of the symptoms were subtle in nature. Tinnitus was significantly (p<0.05 more frequent in the experimental group than the 2 control groups. Conclusions: Long-term exposure to noise may cause vestibular symptoms before clinically detectable hearing loss. The symptoms are subtle for which they are mostly neglected; the symptoms do not affect the functional ability of workers.

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

    Science.gov (United States)

    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. Utility of quick oculomotor tests for screening the vestibular system in the subacute and chronic populations.

    Science.gov (United States)

    Cohen, Helen S; Stitz, Jasmine; Sangi-Haghpeykar, Haleh; Williams, Susan P; Mulavara, Ajitkumar P; Peters, Brian T; Bloomberg, Jacob J

    2018-04-01

    The goal of this study was to determine the sensitivity and specificity of some widely used, easily administered clinical tests. Simple tests of oculomotor function have become widely used for clinical screening of patients suspected of having vestibular disorders despite a paucity of evidence showing good statistical support for their use in this highly variable population. Healthy controls with no history of otologic or neurologic disorders (n = 291) were compared to patients with known vestibular disorders (n = 62). All subjects performed passive and active head shaking, un-instrumented head impulse tests (HT), and video head impulse tests (vHIT) recorded with infrared video-oculography. For both passive and active head shaking, using presence/absence of vertigo and of nystagmus, sensitivity was low (<0.40). Sensitivity of presence/absence of saccades on HT was even lower (<0.15). On vHIT, gains were all approximately = 1.0, so sensitivity was very low (approximately 0.15-0.35). Sensitivity and specificity for presence/absence of saccades were moderately poor (less than 0.70). None of these tests are adequate for screening patients in the out-patient clinic for vestibular disorders or for screening people in epidemiologic studies to determine the prevalence of vestibular disorders.

  15. Development of a multichannel vestibular prosthesis prototype by modification of a commercially available cochlear implant.

    Science.gov (United States)

    Valentin, Nicolas S; Hageman, Kristin N; Dai, Chenkai; Della Santina, Charles C; Fridman, Gene Y

    2013-09-01

    No adequate treatment exists for individuals who remain disabled by bilateral loss of vestibular (inner ear inertial) sensation despite rehabilitation. We have restored vestibular reflexes using lab-built multichannel vestibular prostheses (MVPs) in animals, but translation to clinical practice may be best accomplished by modification of a commercially available cochlear implant (CI). In this interim report, we describe preliminary efforts toward that goal. We developed software and circuitry to sense head rotation and drive a CI's implanted stimulator (IS) to deliver up to 1 K pulses/s via nine electrodes implanted near vestibular nerve branches. Studies in two rhesus monkeys using the modified CI revealed in vivo performance similar to our existing dedicated MVPs. A key focus of our study was the head-worn unit (HWU), which magnetically couples across the scalp to the IS. The HWU must remain securely fixed to the skull to faithfully sense head motion and maintain continuous stimulation. We measured normal and shear force thresholds at which HWU-IS decoupling occurred as a function of scalp thickness and calculated pressure exerted on the scalp. The HWU remained attached for human scalp thicknesses from 3-7.8 mm for forces experienced during routine daily activities, while pressure on the scalp remained below capillary perfusion pressure.

  16. Sensitivity evaluation in air and water caloric stimulation of the vestibular organs using videonystagmography.

    Science.gov (United States)

    Jałocha-Kaczka, Anna; Pietkiewicz, Piotr; Zielińska-Bliźniewska, Hanna; Miłoński, Jarosław; Olszewski, Jurek

    2014-01-01

    The aim of the study was to compare air and water caloric stimulation of the vestibular organs using videonystagmography (VNG). The study covered 18 women aged 21-63 and 11 men aged 21-74 years hospitalized at the ENT, without complaints for vertigo and/or balance disorders. The alternate binaural bithermal caloric test with cool 30°C and warm 44°C air or water irrigations (after 2h interval for the recordings) with the use of VNG was done. All parameters of air and water vestibular caloric stimulations, assessed in the VNG, differed significantly but were within the normal range. The research showed a statistically significant difference between canal paresis but only for the left ear at 30°C and 44°C. Absolute directional preponderance, relative directional preponderance, vestibular excitability, slow component velocity, frequency were different statistically for both ears at both temperatures. Our study showed that both air and water caloric stimulations were able to distinguish physiological and impaired vestibular function. The obtained results showed statistically higher response for water than air stimulation. Copyright © 2014 Polish Otorhinolaryngology - Head and Neck Surgery Society. Published by Elsevier Urban & Partner Sp. z.o.o. All rights reserved.

  17. Early diagnosis of acoustic neuroma by the vestibular test

    Energy Technology Data Exchange (ETDEWEB)

    Haid, T; Rettinger, G; Berg, M; Wigand, M E

    1981-11-01

    In a series of 390 cases with suspicion of acoustic neurinomas 78 such tumors could be diagnosed, including 12 early stage neurinomas. This relatively high detection quote of small neurinomas is due to a special diagnostical programme: Every patient with unilateral and sensoneural hearingloss, independent of vertigo anamnesis or of the result of X-rays must be further examined by a vestibular test. All 78 patients with acoustic neuroma had pathological vestibular findings. The positional test turned out to be the most sensitive examination in the early diagnosis of acoustic neuromas and yields a still higher incidence than the thermic test: 95% of the patients with a neuroma showed pathological findings in the positional test. Every patient suffering from an unidentified unilateral and sensoneural hearingloss combined with a pathological result in the positional test must be further checked by a cisternomeatography or computerized tomography using airinsufflation. Every fifth of these patients showed typical signs of an acoustic neuroma in the neuroradiological tests. 68 neuromas are operated today and verfied histologically, 10 patients are still waiting for surgical treatment.

  18. Evaluation of vestibular evoked myogenic potentials (VEMP) and electrocochleography for the diagnosis of Ménière's disease.

    Science.gov (United States)

    Lamounier, Pauliana; de Souza, Thiago Silva Almeida; Gobbo, Debora Aparecida; Bahmad, Fayez

    Ménière's disease (MD) is an inner ear disorder characterized by episodic vertigo, tinnitus, ear fullness, and fluctuating hearing. Its diagnosis can be especially difficult in cases where vestibular symptoms are present in isolation (vestibular MD). The definitive diagnosis is made histologically and can only be performed post-mortem, after analysis of the temporal bone. Endolymphatic hydrops is a histopathological finding of the disease and occurs more often in the cochlea and saccule, followed by the utricle and semicircular canals. Vestibular evoked myogenic potentials (VEMP) emerged as the method of assessment of vestibular function in 1994. Until then, there was no unique way of assessing saccular function and the inferior vestibular nerve. Given that the saccule is responsible for most cases of severe hydrops, VEMP appears as a new tool to assist in the diagnosis of MD. To evaluate the sensitivity and specificity of VEMP and electrocochleography (EcochG) in the diagnosis of definite MD compared with clinical diagnosis. The study includes 12 patients (24 ears) diagnosed with definite MD defined according to the clinical criteria proposed by the American Academy of Otolaryngology - Head and Neck Surgery (AAO-HNS) in 1995, as well as 12 healthy volunteers allocated to the control group (24 ears). A clinical diagnosis by the AAO-HNS criteria was considered as the gold standard. All patients underwent an otoneurological examination, including pure tone and speech audiometry, VEMP, and extratympanic EcochG. The sensitivity and specificity to detect the presence or absence of disease were calculated, as well as their 95% confidence intervals. The reliability of VEMP and EcochG in both ears was assessed using the kappa index. In both tests and in both ears, the ability to diagnose healthy cases was high, with specificity ranging from 84.6% to 100%. Moreover, the ability of the tests to diagnose the disease varied from low to moderate sensitivity, with values

  19. Vestibular-ocular accommodation reflex in man

    Science.gov (United States)

    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.

  20. Potenciais miogênicos evocados vestibulares: metodologias de registro em homens e cobaias Vestibular evoked myogenic potential: recording methods in humans and guinea pigs

    Directory of Open Access Journals (Sweden)

    Aline Cabral de Oliveira

    2008-10-01

    Full Text Available O potencial miogênico evocado vestibular (VEMP é um teste clínico que avalia a função vestibular através de um reflexo vestíbulo-cervical inibitório captado nos músculos do corpo em resposta à estimulação acústica de alta intensidade. OBJETIVO: Verificar e analisar os diversos métodos de registro dos potenciais miogênicos evocados vestibulares no homem e em cobaias. MATERIAL E MÉTODO: Realizou-se busca eletrônica nas bases de dados MEDLINE, LILACS, SCIELO e COCHRANE. RESULTADOS: Foram verificadas divergências quanto às formas de registro dos potenciais miogênicos evocados vestibulares, relacionadas com os seguintes fatores: posição do paciente no momento do registro, tipo de estímulo sonoro utilizado (clicks ou tone bursts, parâmetros para a promediação dos estímulos (intensidade, freqüência, tempo de apresentação, filtros, ganho de amplificação das respostas e janelas para captação dos estímulos, tipo de fone utilizado e forma de apresentação dos estímulos (monoaural ou binaural, ipsi ou contralateral. CONCLUSÃO: Não existe consenso na literatura quanto ao melhor método de registro dos potenciais evocados miogênicos vestibulares, havendo necessidade de pesquisas mais específicas para comparação entre estes registros e a definição de um modelo padrão para a utilização na prática clínica.The vestibular evoked myogenic potential (VEMP is a clinical test that assess the vestibular function by means of an inhibitory vestibulo-neck reflex, recorded in body muscles in response to high intensity acoustic stimuli. AIM: To check and analyze the different methods used to record VEMPs in humans and in guinea pigs. MATERIALS AND METHODS: We researched the following databases: MEDLINE, LILACS, SCIELO and COCHRANE. RESULTS: we noticed discrepancies in relation to the ways used to record the vestibular evoked myogenic potentials in relation to the following factors: patient position at the time of recording

  1. Complications of microsurgery of vestibular schwannoma

    Czech Academy of Sciences Publication Activity Database

    Betka, J.; Zvěřina, E.; Balogová, Zuzana; Profant, Oliver; Skřivan, J.; Kraus, J.; Lisý, J.; Syka, Josef; Chovanec, M.

    2014-01-01

    Roč. 2014, May 28 (2014), s. 315952 ISSN 2314-6133 R&D Projects: GA MZd NT12459 Grant - others:GA MZd(CZ) NT11543; GA MŠk(CZ) UNCE 204013; GA UK(CZ) SVV 266513; GA MŠk(CZ) Prvouk-P27/LF1/1 Institutional support: RVO:68378041 Keywords : acoustic neurona surgery * tumor surgery * vestibular schwannomas Subject RIV: FF - HEENT, Dentistry Impact factor: 1.579, year: 2014

  2. Vestibular evoked myogenic potentials and video head impulse test in patients with vertigo, dizziness and imbalance.

    Science.gov (United States)

    Skorić, Magdalena Krbot; Adamec, Ivan; Pavičić, Tin; Pavlović, Ivan; Ruška, Berislav; Crnošija, Luka; Habek, Mario

    2017-05-01

    The aim of this study was to compare vestibular evoked myogenic potentials (VEMP) and video head impulse test (vHIT) results in patients presenting with vertigo and dizziness. We retrospectively analyzed data of all patients with the chief complaint of vertigo, dizziness, or imbalance that underwent VEMP and vHIT from January 2015 to January 2016. A total of 117 patients (73 females, mean age 53.92±16.76) fulfilled inclusion criteria: group 1 included patients with the final diagnosis of vestibular neuritis (VN) (N=31 (16 right and 15 left VN)), group 2 included patients with the final diagnosis of vertigo of central origin (N=23) and group 3 included patients with the final diagnosis of unspecified dizziness (N=63). There was significant correlation between oVEMP asymmetry and asymmetry of the lateral canals 60ms gains on vHIT (r=0.225, p=0.026). Significant correlation between oVEMP and vHIT asymmetry was present in VN patients (r=0.749, p<0.001), while no correlation was found in the groups 2 and 3. oVEMP and vHIT lateral canals asymmetries were significantly greater in patients with vestibular neuritis. Furthermore, positive correlations of oVEMP amplitudes with 60ms gain of the lateral semicircular canal and slope of the anterior semicircular canal on vHIT, and cVEMP with slope of the posterior semicircular canal on the vHIT were found. These changes were significantly more pronounced in patients with vestibular neuritis. In conclusion, VEMPs and vHIT data should be used complementarily; asymmetry on both tests strongly supports peripheral vestibular system involvement. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Characterizing human vestibular sensory epithelia for experimental studies: new hair bundles on old tissue and implications for therapeutic interventions in ageing

    OpenAIRE

    Taylor, Ruth R.; Jagger, Daniel J.; Saeed, Shakeel R.; Axon, Patrick; Donnelly, Neil; Tysome, James; Moffatt, David; Irving, Richard; Monksfield, Peter; Coulson, Chris; Freeman, Simon R.; Lloyd, Simon K.; Forge, Andrew

    2015-01-01

    Balance disequilibrium is a significant contributor to falls in the elderly. The most common cause of balance dysfunction is loss of sensory cells from the vestibular sensory epithelia of the inner ear. However, inaccessibility of inner ear tissue in humans severely restricts possibilities for experimental manipulation to develop therapies to ameliorate this loss. We provide a structural and functional analysis of human vestibular sensory epithelia harvested at trans-labyrinthine surgery. We ...

  4. Effect of caffeine on vestibular evoked myogenic potential: a systematic review with meta-analysis.

    Science.gov (United States)

    Souza, Maria Eduarda Di Cavalcanti Alves de; Costa, Klinger Vagner Teixeira da; Menezes, Pedro de Lemos

    2017-12-24

    Caffeine can be considered the most consumed drug by adults worldwide, and can be found in several foods, such as chocolate, coffee, tea, soda and others. Overall, caffeine in moderate doses, results in increased physical and intellectual productivity, increases the capacity of concentration and reduces the time of reaction to sensory stimuli. On the other hand, high doses can cause noticeable signs of mental confusion and error induction in intellectual tasks, anxiety, restlessness, muscle tremors, tachycardia, labyrinthine changes, and tinnitus. Considering that the vestibular evoked myogenic potential is a clinical test that evaluates the muscular response of high intensity auditory stimulation, the present systematic review aimed to analyze the effects of caffeine on vestibular evoked myogenic potential. This study consisted of the search of the following databases: MEDLINE, CENTRAL, ScienceDirect, Scopus, Web of Science, LILACS, SciELO and ClinicalTrials.gov. Additionally, the gray literature was also searched. The search strategy included terms related to intervention (caffeine or coffee consumption) and the primary outcome (vestibular evoked myogenic potential). Based on the 253 potentially relevant articles identified through the database search, only two full-text publications were retrieved for further evaluation, which were maintained for qualitative analysis. Analyzing the articles found, caffeine has no effect on vestibular evoked myogenic potential in normal individuals. Copyright © 2017 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  5. Investigating the Effects of Vestibular Stimulation on Balance Performance in Children with Cerebral Palsy: A Randomized Clinical Trial Study

    Directory of Open Access Journals (Sweden)

    Seyed Ali Hosseini

    2015-06-01

    Full Text Available Background: Centre of pressure displacement is an indicator of postural control. Children with cerebral palsy have poor postural control. One common intervention to enhance their balance is vestibular stimulation. The aim of this research was to investigate the effect of vestibular stimulation on COP parameters in children with cerebral palsy (3-10 years old. Methods: This study was a randomized double-blind controlled clinical trial. Twenty children with cerebral palsy received vestibular stimulation, two sessions per week with a course of twelve sessions, based on vestibular stimulation protocol including anteroposterior, lateral, ascending–descending movements and spinning. One cerebral palsy group experienced current and conventional occupational therapy while the other received a period of vestibular stimulation during treatment. Force plate outcome measures were center of pressure displacement parameters as well as velocity, area, displacement in X and Y axes. Results: According to Mann-Whitney U test, means in post-tests in two groups with both conditions of eyes open and closed were significant in velocity parameter (eyes open P=0.036; eyes closed P=0.021 while Area parameter, COP displacement in X axis (Rang fore after, COP displacement in Y axis (Rang side way were not significant (P>0.05. Wilcoxon Test showed significant difference in the velocity parameter; eyes open (P=0.012 and eyes closed (P=0.018. Conclusion: Children who received vestibular stimulation are able to change and control COP displacement faster (according to changes in velocity parameters. So we suggest rehabilitation team members especially occupational therapist to apply vestibular stimulation during their treatment.

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

    Science.gov (United States)

    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 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 augment current assessment tools and may serve as a single component of a comprehensive approach

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

    Directory of Open Access Journals (Sweden)

    Chen Po-Yin

    2012-10-01

    Full Text Available Abstract 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.

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

    Science.gov (United States)

    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.

  9. Neurosteroid modulation of neuronal excitability and synaptic transmission in the rat medial vestibular nuclei.

    Science.gov (United States)

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

    2007-07-01

    In rat brainstem slices, we investigated the influence of the neurosteroids tetrahydrodeoxycorticosterone (THDOC) and allopregnanolone (ALLO) on the synaptically driven and spontaneous activity of vestibular neurons, by analysing their effects on the amplitude of the field potentials evoked in the medial vestibular nuclei (MVN) by vestibular afferent stimulation and on the spontaneous firing rate of MVN neurons. Furthermore, the interaction with gamma-aminobutyric acid (GABA) and glutamate receptors was analysed by using specific antagonists for GABA(A) (bicuculline), alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/ kainate [2,3-dioxo-6-nitro-1,2,3,4-tetrahydrobenzo(f)quinoxaline-7-sulphonamide disodium salt (NBQX)], N-methyl-D-aspartate (NMDA) [D-(-)-2-amino-5-phosphonopentanoic acid (AP-5)] and group I metabotropic glutamate receptors (mGlu-I) [(R,S)-1-aminoindan-1,5-dicarboxylic acid (AIDA)] receptors. THDOC and ALLO evoked two opposite long-lasting effects, consisting of either a potentiation or a reduction of field potential and firing rate, which showed early and late components, occurring in conjunction or separately after neurosteroid application. The depressions depended on GABA(A) receptors, as they were abolished by bicuculline, while early potentiation involved glutamate AMPA/kainate receptors, as NBQX markedly reduced the incidence of early firing rate enhancement and, in the case of ALLO, even provoked depression. This suggests that THDOC and ALLO enhance the GABA(A) inhibitory influence on the MVN neurons and facilitate the AMPA/kainate facilitatory one. Conversely, a late potentiation effect, which was still induced after glutamate and GABA(A) receptor blockade, might involve a different mechanism. We conclude that the modulation of neuronal activity in the MVN by THDOC and ALLO, through their actions on GABA(A) and AMPA/kainate receptors, may have a physiological role in regulating the vestibular system function under normal

  10. Avaliação vestibular por videonistagmografia de portadores de deficiência crônica de zinco por síndrome do intestino curto Vestibular evaluation using videonystagmography of chronic zinc deficient patients due to short bowell syndrome

    Directory of Open Access Journals (Sweden)

    Gustavo Duarte Paiva Ferreira

    2009-04-01

    Full Text Available A presença do elemento químico zinco na via auditiva e a sua provável participação na gênese de alguns tipos de disacusia estão bem documentadas, porém não há estudos funcionais que mostrem os impacto da deficiência sistêmica de zinco no sistema vestibular, nem estudos anatômicos descritivos comprovando a existência do íon nas estruturas da via vestibular. OBJETIVO: Este estudo foi realizado com o objetivo de relacionar a alteração na homeostase do zinco com anormalidades do funcionamento da via vestibular. MATERIAL E MÉTODOS: Este é um estudo de casos, retrospectivo, clínico, onde nove indivíduos portadores de deficiência crônica de zinco, entre outros distúrbios nutricionais, consequentes à síndrome de má absorção, foram submetidos à avaliação vestibular. Os resultados deste grupo foram comparados com os resultados de um grupo considerado normal do ponto de vista nutricional (grupo controle. RESULTADOS: Todos os parâmetros da análise vestibular do grupo experimental mostraram-se alterados em comparação com o grupo controle. CONCLUSÃO: A comparação entre os grupos mostrou diferenças significativas em diversos parâmetros da análise vestibular e chamou a atenção para uma possível participação das alterações disabsortivas na origem das desordens vestibulares.The presence of zinc in the auditory pathways and its probable participation in tinnitus and hearing loss are known facts, although there are no clinical trials and experimental studies showing the impact of hypozincemia in the vestibular system and zinc existence in the vestibular pathway, respectively. AIM: This study is an attempt to correlate hypozincemia and abnormal vestibular function. METHODS: This is a clinical retrospective case study where nine patients suffering of chronic zinc deficiency had their serum zinc determined and were submitted to videonystagmography. Results were compared to a normal (control group. RESULTS: All

  11. TRANSAT-- method for detecting the conserved helices of functional RNA structures, including transient, pseudo-knotted and alternative structures.

    Science.gov (United States)

    Wiebe, Nicholas J P; Meyer, Irmtraud M

    2010-06-24

    The prediction of functional RNA structures has attracted increased interest, as it allows us to study the potential functional roles of many genes. RNA structure prediction methods, however, assume that there is a unique functional RNA structure and also do not predict functional features required for in vivo folding. In order to understand how functional RNA structures form in vivo, we require sophisticated experiments or reliable prediction methods. So far, there exist only a few, experimentally validated transient RNA structures. On the computational side, there exist several computer programs which aim to predict the co-transcriptional folding pathway in vivo, but these make a range of simplifying assumptions and do not capture all features known to influence RNA folding in vivo. We want to investigate if evolutionarily related RNA genes fold in a similar way in vivo. To this end, we have developed a new computational method, Transat, which detects conserved helices of high statistical significance. We introduce the method, present a comprehensive performance evaluation and show that Transat is able to predict the structural features of known reference structures including pseudo-knotted ones as well as those of known alternative structural configurations. Transat can also identify unstructured sub-sequences bound by other molecules and provides evidence for new helices which may define folding pathways, supporting the notion that homologous RNA sequence not only assume a similar reference RNA structure, but also fold similarly. Finally, we show that the structural features predicted by Transat differ from those assuming thermodynamic equilibrium. Unlike the existing methods for predicting folding pathways, our method works in a comparative way. This has the disadvantage of not being able to predict features as function of time, but has the considerable advantage of highlighting conserved features and of not requiring a detailed knowledge of the cellular

  12. Telefones celulares: influência nos sistemas auditivo e vestibular Mobile phones: influence on auditory and vestibular systems

    Directory of Open Access Journals (Sweden)

    Aracy Pereira Silveira Balbani

    2008-02-01

    review. METHODS: 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. RESULTS: 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. CONCLUSION: there is no evidence of cochleo-vestibular lesion caused by cellular phones.

  13. Effect of yoga practices on pulmonary function tests including transfer factor of lung for carbon monoxide (TLCO) in asthma patients.

    Science.gov (United States)

    Singh, Savita; Soni, Ritu; Singh, K P; Tandon, O P

    2012-01-01

    Prana is the energy, when the self-energizing force embraces the body with extension and expansion and control, it is pranayama. It may affect the milieu at the bronchioles and the alveoli particularly at the alveolo-capillary membrane to facilitate diffusion and transport of gases. It may also increase oxygenation at tissue level. Aim of our study is to compare pulmonary functions and diffusion capacity in patients of bronchial asthma before and after yogic intervention of 2 months. Sixty stable asthmatic-patients were randomized into two groups i.e group 1 (Yoga training group) and group 2 (control group). Each group included thirty patients. Lung functions were recorded on all patients at baseline, and then after two months. Group 1 subjects showed a statistically significant improvement (Pincreased significantly. It was concluded that pranayama & yoga breathing and stretching postures are used to increase respiratory stamina, relax the chest muscles, expand the lungs, raise energy levels, and calm the body.

  14. Estimation of Optimum Stimulus Amplitude for Balance Training using Electrical Stimulation of the Vestibular System

    Science.gov (United States)

    Goel, R.; Rosenberg, M. J.; De Dios, Y. E.; Cohen, H. S.; Bloomberg, J. J.; Mulavara, A. P.

    2016-01-01

    Sensorimotor changes such as posture and gait instabilities can affect the functional performance of astronauts after gravitational transitions. Sensorimotor Adaptability (SA) training can help alleviate decrements on exposure to novel sensorimotor environments based on the concept of 'learning to learn' by exposure to varying sensory challenges during posture and locomotion tasks (Bloomberg 2015). Supra-threshold Stochastic Vestibular Stimulation (SVS) can be used to provide one of many challenges by disrupting vestibular inputs. In this scenario, the central nervous system can be trained to utilize veridical information from other sensory inputs, such as vision and somatosensory inputs, for posture and locomotion control. The minimum amplitude of SVS to simulate the effect of deterioration in vestibular inputs for preflight training or for evaluating vestibular contribution in functional tests in general, however, has not yet been identified. Few studies (MacDougall 2006; Dilda 2014) have used arbitrary but fixed maximum current amplitudes from 3 to 5 mA in the medio-lateral (ML) direction to disrupt balance function in healthy adults. Giving this high level of current amplitude to all the individuals has a risk of invoking side effects such as nausea and discomfort. The goal of this study was to determine the minimum SVS level that yields an equivalently degraded balance performance. Thirteen subjects stood on a compliant foam surface with their eyes closed and were instructed to maintain a stable upright stance. Measures of stability of the head, trunk, and whole body were quantified in the ML direction. Duration of time they could stand on the foam surface was also measured. The minimum SVS dosage was defined to be that level which significantly degraded balance performance such that any further increase in stimulation level did not lead to further balance degradation. The minimum SVS level was determined by performing linear fits on the performance variable

  15. Computation of transverse muon-spin relaxation functions including trapping-detrapping reactions, with application to electron-irradiated tantalum

    International Nuclear Information System (INIS)

    Doering, K.P.; Aurenz, T.; Herlach, D.; Schaefer, H.E.; Arnold, K.P.; Jacobs, W.; Orth, H.; Haas, N.; Seeger, A.; Max-Planck-Institut fuer Metallforschung, Stuttgart

    1986-01-01

    A new technique for the economical evaluation of transverse muon spin relaxation functions in situations involving μ + trapping at and detrapping from crystal defects is applied to electron-irradiated Ta exhibiting relaxation maxima at about 35 K, 100 K, and 250 K. The long-range μ + diffusion is shown to be limted by traps over the entire temperature range investigated. The (static) relaxation rates for several possible configurations of trapped muons are discussed, including the effect of the simultaneous presence of a proton in a vacancy. (orig.)

  16. 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.

    Science.gov (United States)

    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.

  17. [Skull vibratory test in partial vestibular lesions--influence of the stimulus frequency on the nystagmus direction].

    Science.gov (United States)

    Dumas, G; Perrin, P; Morel, N; N'Guyen, D Q; Schmerber, S

    2005-01-01

    Results of the skull vibratory test (SVT) in partial unilateral vestibular peripheral lesions (PUVL) are different from the results in total vestibular lesions (TUVL). To reveal a correlation between the results of the analysis of the skull vibratory nystagmus (SVN) horizontal component and the side of the lesion; to correlate these results with the stimulus frequency. To find out a predictive correlation between the SVN horizontal and vertical components and the topography of a vestibular lesion. To appreciate the degree of vestibular deafferentation (extended to high frequencies) provoked by gentamicin labyrinthectomy and its efficiency in Meniere's disease. 53 patients with a SVN and a PUVL were included and compared with 10 TUVL and 10 normal subjects. Protocol included a HST (2 Hz), a SVT at 30, 60 and 100 Hz and a caloric test. Recordings were performed with a 2D and 3D VNG device. In PUVL, SVN at 30, 60 and 100 Hz was obtained in 80, 90 and 90% of cases respectively. SVN is correlated with the side of the lesion at 30, 60 and 100 Hz respectively in 65%, 63%, 80% of cases. SVN is not correlated with the side of the lesion in 20% of Meniere's disease, in 8% of vestibular neuritis and in 6% of vestibular schwannoma. In PUVL HSN is correlated with the side of the lesion in 69% of cases. The direction of the HSN and of the SVN was different in 23% when the nystagmus attended at the same time for both tests. In PUVL the direction of the SVN is different at 100 Hz and 30 Hz in 16% of cases when they are concomittant on the same patient. After Gentamicine labyrinthectomy, the coherence of the results in caloric test, HSN and SVN (areflexy and lesional nystagmus beating toward the safe side) was correlated with the efficiency of the therapy. A SVN vertical component was met in 10% of PUVL (essentially in anterior canal dehiscence and few cases of partial labyrinthitis). The horizontal SVN SPV is significantly slower in PUVL than in TUVL patients (p=0.0004). The SVT

  18. Are stage IV vestibular schwannomas preoperatively different from other stages?

    Science.gov (United States)

    Tringali, Stéphane; Dubreuil, Christian; Zaouche, Sandra; Ferber-Viart, Chantal

    2008-01-01

    The aim of this study was to focus on the clinical and paraclinical symptoms of patients suffering from Stage IV vestibular schwannomas (VSs). In this prospective study, we included 734 patients who have VS and candidates for operation. Patients were classified as having Stage I, II, III, or IV tumors according to Tos criteria as evaluated by magnetic resonance imaging. PREOPERATIVE CLINICAL EVALUATION: We recorded the occurrence of complaints (%) and duration (yr) of hearing loss, tinnitus, and balance disorder. Preoperative paraclinical evaluation included pure-tone (PTA) and speech audiometry, auditory brainstem response (ABR) patterns, and vestibular deficit at videonystamography (VNG). Continuous variables were compared between Stage IV and other stages using analysis of variance. Qualitative variables expressed as a percentage of presence were compared between Stage IV and other stages using percentage comparison. Quantitative Parameters. Patients with Stage IV VS were significantly younger as compared with patients with other stages. Stage IV hearing loss was greater compared with other stages at 250 and 500 Hz but smaller at 2,000 and 8,000 Hz. We found no difference in the loss of PTA between Stage IV and the other stages. Speech discriminancy score was smaller in Stage IV. The durations of hearing loss, tinnitus, and balance disorders were similar whatever the tumor stage. Auditory brainstem response patterns showed no difference in Wave III latency between Stage IV VS and other stages, whereas Wave V latency and V-I interval were higher in Stage IV. Both ABR threshold and VNG caloric deficit were higher in Stage IV VS compared with other stages. Qualitative Parameters. The percentage of patients with Stage IV was lower than that with Stages II and III. The percentage of men and women was similar in all stages. The occurrence of hearing loss was similar in all stages, whereas that of tinnitus was lower in Stage IV compared with Stages I and II. In

  19. Translabyrinthine surgery for disabling vertigo in vestibular schwannoma patients

    NARCIS (Netherlands)

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

    2007-01-01

    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

  20. Body ownership and embodiment: vestibular and multisensory mechanisms.

    Science.gov (United States)

    Lopez, C; Halje, P; Blanke, O

    2008-06-01

    Body ownership and embodiment are two fundamental mechanisms of self-consciousness. The present article reviews neurological data about paroxysmal illusions during which body ownership and embodiment are affected differentially: autoscopic phenomena (out-of-body experience, heautoscopy, autoscopic hallucination, feeling-of-a-presence) and the room tilt illusion. We suggest that autoscopic phenomena and room tilt illusion are related to different types of failures to integrate body-related information (vestibular, proprioceptive and tactile cues) in addition to a mismatch between vestibular and visual references. In these patients, altered body ownership and embodiment has been shown to occur due to pathological activity at the temporoparietal junction and other vestibular-related areas arguing for a key importance of vestibular processing. We also review the possibilities of manipulating body ownership and embodiment in healthy subjects through exposition to weightlessness as well as caloric and galvanic stimulation of the peripheral vestibular apparatus. In healthy subjects, disturbed self-processing might be related to interference of vestibular stimulation with vestibular cortex leading to disintegration of bodily information and altered body ownership and embodiment. We finally propose a differential contribution of the vestibular cortical areas to the different forms of altered body ownership and embodiment.

  1. Vestibular morphology in the German Waltzing guinea pig.

    Science.gov (United States)

    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.

  2. Long-term hearing preservation in vestibular schwannoma

    DEFF Research Database (Denmark)

    Stangerup, Sven-Eric; Thomsen, Jens; Tos, Mirko

    2010-01-01

    The aim of the present study was to evaluate the long-term hearing during "wait and scan" management of vestibular schwannomas.......The aim of the present study was to evaluate the long-term hearing during "wait and scan" management of vestibular schwannomas....

  3. Evidence for cognitive vestibular integration impairment in idiopathic scoliosis patients

    Directory of Open Access Journals (Sweden)

    Mercier Pierre

    2009-08-01

    Full Text Available Abstract Background Adolescent idiopathic scoliosis is characterized by a three-dimensional deviation of the vertebral column and its etiopathogenesis is unknown. Various factors cause idiopathic scoliosis, and among these a prominent role has been attributed to the vestibular system. While the deficits in sensorimotor transformations have been documented in idiopathic scoliosis patients, little attention has been devoted to their capacity to integrate vestibular information for cognitive processing for space perception. Seated idiopathic scoliosis patients and control subjects experienced rotations of different directions and amplitudes in the dark and produced saccades that would reproduce their perceived spatial characteristics of the rotations (vestibular condition. We also controlled for possible alteration of the oculomotor and vestibular systems by measuring the subject's accuracy in producing saccades towards memorized peripheral targets in absence of body rotation and the gain of their vestibulo-ocular reflex. Results Compared to healthy controls, the idiopathic scoliosis patients underestimated the amplitude of their rotations. Moreover, the results revealed that idiopathic scoliosis patients produced accurate saccades to memorized peripheral targets in absence of body rotation and that their vestibulo-ocular reflex gain did not differ from that of control participants. Conclusion Overall, results of the present study demonstrate that idiopathic scoliosis patients have an alteration in cognitive integration of vestibular signals. It is possible that severe spine deformity developed partly due to impaired vestibular information travelling from the cerebellum to the vestibular cortical network or alteration in the cortical mechanisms processing the vestibular signals.

  4. Visual-vestibular integration motion perception reporting

    Science.gov (United States)

    Harm, Deborah L.; Reschke, Millard R.; Parker, Donald E.

    1999-01-01

    Self-orientation and self/surround-motion perception derive from a multimodal sensory process that integrates information from the eyes, vestibular apparatus, proprioceptive and somatosensory receptors. Results from short and long duration spaceflight investigations indicate that: (1) perceptual and sensorimotor function was disrupted during the initial exposure to microgravity and gradually improved over hours to days (individuals adapt), (2) the presence and/or absence of information from different sensory modalities differentially affected the perception of orientation, self-motion and surround-motion, (3) perceptual and sensorimotor function was initially disrupted upon return to Earth-normal gravity and gradually recovered to preflight levels (individuals readapt), and (4) the longer the exposure to microgravity, the more complete the adaptation, the more profound the postflight disturbances, and the longer the recovery period to preflight levels. While much has been learned about perceptual and sensorimotor reactions and adaptation to microgravity, there is much remaining to be learned about the mechanisms underlying the adaptive changes, and about how intersensory interactions affect perceptual and sensorimotor function during voluntary movements. During space flight, SMS and perceptual disturbances have led to reductions in performance efficiency and sense of well-being. During entry and immediately after landing, such disturbances could have a serious impact on the ability of the commander to land the Orbiter and on the ability of all crew members to egress from the Orbiter, particularly in a non-nominal condition or following extended stays in microgravity. An understanding of spatial orientation and motion perception is essential for developing countermeasures for Space Motion Sickness (SMS) and perceptual disturbances during spaceflight and upon return to Earth. Countermeasures for optimal performance in flight and a successful return to Earth require

  5. Reliability of inertial sensors in the assessment of patients with vestibular disorders: a feasibility study

    Directory of Open Access Journals (Sweden)

    Sathish K. Sankarpandi

    2017-02-01

    Full Text Available Abstract Background Vestibular disorders affect an individual’s stability, balance, and gait and predispose them to falls. Traditional laboratory-based semi-objective vestibular assessments are intrusive and cumbersome provide little information about their functional ability. Commercially available wearable inertial sensors allow us to make this real life assessments objective, with a detailed view of their functional abilities. Timed Up and Go (TUG and Postural Sway tests are commonly used tests for gait and balance assessments. Our aim was to assess the feasibility, test-retest reliability and ability to classify fall status in individuals with vestibular disorders using parameters derived from the commercially available wearable system (inertial sensors and the Mobility Lab Software, APDM, Inc.. Methods We recruited 27 individuals diagnosed either with unilateral or bilateral vestibular loss on vestibular function testing. Instrumented Timed Up and Go (iTUG and Postural Sway (iSway were administered three times during the first session and then repeated at a similar time the following week. To evaluate within and between sessions reliability of the parameters the Intra-Class Correlation coefficient (ICC was used. Subsequently, the ability of reliable parameters (ICC ≥ 0.8 to classify fallers from non-fallers was estimated. Results The iTUG test parameters showed good within and between sessions’ reliability with mean ICC (between-sessions values of 0.81 ± 0.17 and 0.69 ± 0.15, respectively. For the iSway test, the relative figures were; 0.76 ± 0.13 and 0.71 ± 0.14, respectively. A retrospective falls classification analysis with past 12 months falls history data yielded an accuracy of 66.70% with an area under the curve of 0.79. Mean Distance from centre of COP (mm of accelerometer’s trajectory (m/s2 from the iSway test was the only significant parameter to classify fallers from non-fallers. Conclusions Using

  6. Head–Eye Vestibular Motion Therapy Affects the Mental and Physical Health of Severe Chronic Postconcussion Patients

    Directory of Open Access Journals (Sweden)

    Frederick Robert Carrick

    2017-08-01

    Full Text Available ContextApproximately 1.8–3.6 million annual traumatic brain injuries occur in the United States. An evidence-based treatment for concussions that is reliable and effective has not been available.ObjectiveThe objective of this study is to test whether head–eye vestibular motion (HEVM therapy is associated with decreased symptoms and increased function in postconcussive syndrome (PCS patients that have been severely impaired for greater than 6 months after a mild traumatic brain injury.DesignRetrospective clinical chart review.Setting and participantsTertiary Specialist Brain Rehabilitation Center.InterventionsAll subjects underwent comprehensive neurological examinations including measurement of eye and head movement. The seven modules of the C3 Logix Comprehensive Concussion Management System were used for pre- and postmeasurements of outcome of HEVM therapy.Materials and methodsWe utilized an objective validated measurement of physical and mental health characteristics of our patients before and after a 1-week HEVM rehabilitation program. We included only PCS patients that were disabled from work or school for a period of time exceeding 6 months after suffering a sports concussion. These subjects all were enrolled in a 5-day HEVM rehabilitation program at our Institutional Brain Center with pre- and post-C3 Logix testing outcomes.ResultsThere were statistical and substantive significant decreases in PCS symptom severity after treatment and statistical and substantive significant increases in standardized assessment of concussion scores. The outcomes were associated with positive changes in mental and physical health issues. This is a retrospective review and no control group has been included in this study. These are major limitations with retrospective reviews and further investigations with prospective designs including a randomized controlled study are necessary to further our understanding.ConclusionHead–eye vestibular motion

  7. Vestibular characterization in the menstrual cycle Caracterização vestibular no ciclo menstrual

    Directory of Open Access Journals (Sweden)

    Cintia Ishii

    2009-06-01

    Full Text Available Hormonal disorders in the menstrual cycle can affect labyrinthine fluid homeostasis, causing balance and hearing dysfunctions. STUDY DESIGN: Clinical prospective. AIM: compare the results from vestibular tests in young women, in the premenstrual and postmenstrual periods. MATERIALS AND METHODS: twenty women were selected with ages ranging from 18 to 35 years, who were not using any kind of contraceptive method for at least six months, and without vestibular or hearing complaints. The test was carried out in each subject before and after the menstrual period, respecting the limit of ten days before or after menstruation. RESULTS: there was a statistically significant difference in the menstrual cycle phases only in the following vestibular tests: calibration, saccadic movements, PRPD and caloric-induced nystagmus. We also noticed that age; a regular menstrual cycle; hearing loss or dizziness cases in the family; and premenstrual symptoms such as tinnitus, headache, sleep disorders, anxiety, nausea and hyperacusis can interfere in the vestibular test. CONCLUSION: there are differences in the vestibular tests of healthy women when comparing their pre and postmenstrual periods.As alterações hormonais do ciclo menstrual podem comprometer a homeostase dos fluidos labirínticos, gerando alterações no equilíbrio e na audição. FORMA DO ESTUDO: Clínico prospectivo. OBJETIVO: Comparar os resultados dos testes do exame vestibular em mulheres jovens, nos períodos pré e pós-menstrual. MATERIAL E MÉTODO: Foram selecionadas vinte mulheres, entre dezoito e trinta e cinco anos, que não fizessem uso de qualquer tipo de anticoncepcional, com audição normal e sem queixas vestibulares. O exame vestibular foi realizado em cada participante no período pré e no período pós-menstrual, em ordem aleatória, e respeitando o limite de até dez dias antes do início da menstruação e até dez dias após o início da menstruação. RESULTADO: Foi observada

  8. A vestibular sensation: probabilistic approaches to spatial perception.

    Science.gov (United States)

    Angelaki, Dora E; Klier, Eliana M; Snyder, Lawrence H

    2009-11-25

    The vestibular system helps maintain equilibrium and clear vision through reflexes, but it also contributes to spatial perception. In recent years, research in the vestibular field has expanded to higher-level processing involving the cortex. Vestibular contributions to spatial cognition have been difficult to study because the circuits involved are inherently multisensory. Computational methods and the application of Bayes theorem are used to form hypotheses about how information from different sensory modalities is combined together with expectations based on past experience in order to obtain optimal estimates of cognitive variables like current spatial orientation. To test these hypotheses, neuronal populations are being recorded during active tasks in which subjects make decisions based on vestibular and visual or somatosensory information. This review highlights what is currently known about the role of vestibular information in these processes, the computations necessary to obtain the appropriate signals, and the benefits that have emerged thus far.

  9. Vestibular schwannoma with contralateral facial pain – case report

    Directory of Open Access Journals (Sweden)

    Ghodsi Mohammad

    2003-03-01

    Full Text Available Abstract Background Vestibular schwannoma (acoustic neuroma most commonly presents with ipsilateral disturbances of acoustic, vestibular, trigeminal and facial nerves. Presentation of vestibular schwannoma with contralateral facial pain is quite uncommon. Case presentation Among 156 cases of operated vestibular schwannoma, we found one case with unusual presentation of contralateral hemifacial pain. Conclusion The presentation of contralateral facial pain in the vestibular schwannoma is rare. It seems that displacement and distortion of the brainstem and compression of the contralateral trigeminal nerve in Meckel's cave by the large mass lesion may lead to this atypical presentation. The best practice in these patients is removal of the tumour, although persistent contralateral pain after operation has been reported.

  10. Bioelectrical activity of limb muscles during cold shivering of stimulation of the vestibular apparatus

    Science.gov (United States)

    Kuzmina, G. I.

    1980-01-01

    The effects of caloric and electric stimulation of the vestibular receptors on the EMG activity of limb muslces in anesthetized cats during cold induced shivering involved flexor muscles alone. Both types of stimulation suppressed bioelectrical activity more effectively in the ipsilateral muscles. The suppression of shivering activity seems to be due to the increased inhibitory effect of descending labyrinth pathways on the function of flexor motoneurons.

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

    OpenAIRE

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

    2014-01-01

    Objective Facial nerve palsy is a common complication of treatment for vestibular schwannoma (VS), so preserving facial nerve function is important. The preoperative visualization of the course of facial nerve in relation to VS could help prevent injury to the nerve during the surgery. In this study, we evaluate the accuracy of diffusion tensor tractography (DTT) for preoperative identification of facial nerve. Methods We prospectively collected data from 11 patients with VS, who underwent pr...

  12. Association between functional performance and executive cognitive functions in an elderly population including patients with low ankle–brachial index

    Directory of Open Access Journals (Sweden)

    Ferreira NV

    2015-05-01

    Full Text Available Naomi Vidal Ferreira,1 Paulo Jannuzzi Cunha,2 Danielle Irigoyen da Costa,3 Fernando dos Santos,1 Fernando Oliveira Costa,1 Fernanda Consolim-Colombo,4 Maria Cláudia Irigoyen1 1Heart Institute, Medical School, Universidade de São Paulo, São Paulo, SP, Brazil; 2Neuroimaging in Psychiatry Laboratory, Department of Psychiatry, Medical School, Universidade de São Paulo, São Paulo, SP, Brazil; 3Rio Grande do Sul Cardiology Institute, Fundação Universitária de Cardiologia, Porto Alegre, RS, Brazil; 4Medical School, Universidade Nove de Julho, São Paulo, SP, Brazil Introduction: Peripheral arterial disease, as measured by the ankle–brachial index (ABI, is prevalent among the elderly, and is associated with functional performance, assessed by the 6-minute walk test (6MWT. Executive cognitive function (ECF impairments are also prevalent in this population, but no existing study has investigated the association between ECF and functional performance in an elderly population including individuals with low ABI.Aim: To investigate the association between functional performance, as measured by the 6MWT, and loss in ECF, in an elderly sample including individuals with low ABI.Method: The ABI group was formed by 26 elderly individuals with low ABI (mean ABI: 0.63±0.19, and the control group was formed by 40 elderly individuals with normal ABI (mean ABI: 1.08±0.07. We analyzed functional performance using the 6MWT, global cognition using the Mini-Mental State Examination (MMSE, and ECF using the Digit Span for assessing attention span and working memory, the Stroop Color Word Test (SCWT for assessing information processing speed and inhibitory control/impulsivity, and the Controlled Oral Word Association Test (COWAT for assessing semantic verbal fluency and phonemic verbal fluency. We also used a factor analysis on all of the ECF tests (global ECF.Results: Before adjustment, the ABI group performed worse on global cognition, attention span, working

  13. VESTIBULAR SCHWANNOMA (ACOUSTIC NEUROMA) MIMICKING TEMPOROMANDIBULAR DISORDERS: A CASE REPORT

    Science.gov (United States)

    Bisi, Maurício A.; Selaimen, Caio M. P.; Chaves, Karen D.; Bisi, Melissa C.; Grossi, Márcio L.

    2006-01-01

    Approximately 6 to 16% of patients with trigeminal neuralgia symptoms present intracranial tumors, the most common being the vestibular schwannoma (acoustic neuroma). Some symptoms reported by patients include hearing loss, tinnitus, headaches, vertigo and trigeminal disturbances. An increased muscle response in the surrounding head and neck musculature may also be observed, which mimics signs and symptoms of temporomandibular disorders. In these cases, magnetic resonance imaging (MRI) has proved to be a useful tool in tumor diagnosis. The differential diagnosis between myofascial and neuralgic pain is important, as both may present similar characteristics, while being of different origin, and demanding special treatment approaches. The purpose of this paper is to demonstrate the relationship among trigeminal neuralgia symptoms, intracranial tumors and temporomandibular dysfunction by presenting a clinical case. PMID:19089251

  14. Task-dependent vestibular feedback responses in reaching.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  16. Linear accelerator stereotactic radiosurgery for vestibular schwannomas: a UK series.

    Science.gov (United States)

    Benghiat, H; Heyes, G; Nightingale, P; Hartley, A; Tiffany, M; Spooner, D; Geh, J I; Cruickshank, G; Irving, R M; Sanghera, P

    2014-06-01

    To evaluate non-auditory toxicity and local control after linear accelerator stereotactic radiosurgery (SRS) for the treatment of vestibular schwannomas. The institutional policy was to use SRS for radiologically progressing vestibular schwannomas. Case notes and plans were retrospectively reviewed for all patients undergoing SRS for vestibular schwannomas between September 2002 and June 2012. All patients were surgically immobilised using a BrainLab stereotactic head frame. The treatment plan was generated using BrainLab software (BrainScan 5.03). The aim was to deliver 12 Gy to the surface of the target with no margin. Patients with a minimum of 12 months of follow-up were included for toxicity and local control assessment. Radiological progression was defined as growth on imaging beyond 2 years of follow-up. Overall local control was defined in line with other series as absence of surgical salvage. Ninety-nine patients were identified. Two patients were lost to follow-up. After a median follow-up interval of 2.4 years, the actuarial radiological progression-free survival at 3 years was 100% and overall local control was also 100%. However, two patients progressed radiologically at 3.3 and 4.5 years, respectively. Twenty-one of 97 (22%) evaluable patients suffered trigeminal toxicity and this was persistent in 8/97 (8%). Two of 97 (2%) suffered long-term facial nerve toxicity (one with associated radiological progression causing hemi-facial spasm alone). One of 97 (1%) required intervention for obstructive hydrocephalus. No statistically significant dosimetric relationship could be shown to cause trigeminal or facial nerve toxicity. However, 7/8 patients with persistent trigeminal nerve toxicity had tumours in contact with the trigeminal nerve. SRS delivering 12 Gy using a linear accelerator leads to high local control rates, but only prospective evaluation will fully establish short-term toxicity. In this study, persistent trigeminal toxicity occurred almost

  17. EL SINDROME VESTIBULAR EN EL ADULTO MAYOR

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    Dr. Hamlet Suárez

    2016-11-01

    Full Text Available El vértigo, la inestabilidad y las caídas tienen una incidencia relevante en el adulto mayor, disminuye su calidad de vida y puede ser causa de muerte en esta población. Este artículo describe las presentaciones clínicas y el abordaje de la evaluación de la patología vestibular en este grupo de edad, utilizando diferentes instrumentos para el diagnóstico así como también las reglas generales del tratamiento.

  18. ON A COURNOT DUOPOLY GAME WITH DIFFERENTIATED GOODS, HETEROGENEOUS EXPECTATIONS AND A COST FUNCTION INCLUDING EMISSION COSTS

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    Georges SARAFOPOULOS

    2017-07-01

    Full Text Available In this study we investigate the dynamics of a nonlinear Cournot- type duopoly game with differentiated goods, linear demand and a cost function that includes emission costs. The game is modeled with a system of two difference equations. Existence and stability of equilibria of this system are studied. We show that the model gives more complex chaotic and unpredictable trajectories as a consequence of change in the parameter of horizontal product differentiation and a higher (lower degree of product differentiation (weaker or fiercer competition destabilize (stabilize the economy. The chaotic features are justified numerically via computing Lyapunov numbers and sensitive dependence on initial conditions. Also, we show that in this case there are stable trajectories and a higher (lower degree of product differentiation does not tend to destabilize the economy.

  19. An impedance function approach for soil-structure interaction analyses including structure-to-structure interaction effects

    International Nuclear Information System (INIS)

    Gantayat, A.; Kamil, H.

    1981-01-01

    The dynamic soil-structure and structure-to-structure interaction effects may be determined in one of the two ways: by modeling the entire soil-structure system by a finite-element model, or by using a frequency-dependent (or frequency-independent) impedance function approach. In seismic design of nuclear power plant structures, the normal practice is to use the first approach because of its simplicity and easy availability of computer codes to perform such analyses. However, in the finite-element approach, because of the size and cost restrictions, the three-dimensional behavior of the entire soil-structure system and the radiation damping in soil are only approximately included by using a two-dimensional finite-element mesh. In using the impedance function approach, the soil-structure analyses can be performed in four steps: (a) determination of the dynamic properties of the fixed base superstructure, (b) determination of foundation and structure impedance matrices and input motions, (c) evaluation of foundation motion, (d) analysis of the fixed base superstructure using computed foundation motion. (orig./RW)

  20. Vision rehabilitation for visual-vestibular dysfunction: the role of the neuro-optometrist.

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    Cohen, Allen H

    2013-01-01

    This article discusses, in a clinically relevant format, the importance of including a neuro-optometrist as a member of the management team for patients with balance disorders. To review the importance of vision and visual processing for maintaining a sense of balance and equilibrium and the role of the neuro-optometrist in the overall rehabilitation of patients with balance disorders Dizziness, balance problems and the sensation that the space world is moving (vertigo) are one of the most commonly reported problems in general medical practice. Persons with a central nervous system injury or other idiopathic causes of visual processing problems or who have functional vision problems that are not adequately managed, often experience extreme difficulty with balance and movement, as well as with their perception of space. Consequently, the patient often experiences difficulty functioning in an environment with excessive visual stimulation such as a grocery store or shopping mall. Symptoms of disequilibrium, vestibular and balance problems are commonly a result of VOR disturbance secondary to an inner ear problem and an unstable binocularity. The combination of neuro-optomertic rehabilitative therapy and balance therapy will result in a is an effective treatment for reducing or resolving these symptoms.

  1. Practice guideline: Cervical and ocular vestibular evoked myogenic potential testing: Report of the Guideline Development, Dissemination, and Implementation Subcommittee of the American Academy of Neurology.

    Science.gov (United States)

    Fife, Terry D; Colebatch, James G; Kerber, Kevin A; Brantberg, Krister; Strupp, Michael; Lee, Hyung; Walker, Mark F; Ashman, Eric; Fletcher, Jeffrey; Callaghan, Brian; Gloss, David S

    2017-11-28

    To systematically review the evidence and make recommendations with regard to diagnostic utility of cervical and ocular vestibular evoked myogenic potentials (cVEMP and oVEMP, respectively). Four questions were asked: Does cVEMP accurately identify superior canal dehiscence syndrome (SCDS)? Does oVEMP accurately identify SCDS? For suspected vestibular symptoms, does cVEMP/oVEMP accurately identify vestibular dysfunction related to the saccule/utricle? For vestibular symptoms, does cVEMP/oVEMP accurately and substantively aid diagnosis of any specific vestibular disorder besides SCDS? The guideline panel identified and classified relevant published studies (January 1980-December 2016) according to the 2004 American Academy of Neurology process. Level C positive: Clinicians may use cVEMP stimulus threshold values to distinguish SCDS from controls (2 Class III studies) (sensitivity 86%-91%, specificity 90%-96%). Corrected cVEMP amplitude may be used to distinguish SCDS from controls (2 Class III studies) (sensitivity 100%, specificity 93%). Clinicians may use oVEMP amplitude to distinguish SCDS from normal controls (3 Class III studies) (sensitivity 77%-100%, specificity 98%-100%). oVEMP threshold may be used to aid in distinguishing SCDS from controls (3 Class III studies) (sensitivity 70%-100%, specificity 77%-100%). Level U: Evidence is insufficient to determine whether cVEMP and oVEMP can accurately identify vestibular function specifically related to the saccule/utricle, or whether cVEMP or oVEMP is useful in diagnosing vestibular neuritis or Ménière disease. Level C negative: It has not been demonstrated that cVEMP substantively aids in diagnosing benign paroxysmal positional vertigo, or that cVEMP or oVEMP aids in diagnosing/managing vestibular migraine. © 2017 American Academy of Neurology.

  2. A Comparative Density Functional Theory and Density Functional Tight Binding Study of Phases of Nitrogen Including a High Energy Density Material N8

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    Nicholas Capel

    2015-11-01

    Full Text Available We present a comparative dispersion-corrected Density Functional Theory (DFT and Density Functional Tight Binding (DFTB-D study of several phases of nitrogen, including the well-known alpha, beta, and gamma phases as well as recently discovered highly energetic phases: covalently bound cubic gauche (cg nitrogen and molecular (vdW-bound N8 crystals. Among several tested parametrizations of N–N interactions for DFTB, we identify only one that is suitable for modeling of all these phases. This work therefore establishes the applicability of DFTB-D to studies of phases, including highly metastable phases, of nitrogen, which will be of great use for modelling of dynamics of reactions involving these phases, which may not be practical with DFT due to large required space and time scales. We also derive a dispersion-corrected DFT (DFT-D setup (atom-centered basis parameters and Grimme dispersion parameters tuned for accurate description simultaneously of several nitrogen allotropes including covalently and vdW-bound crystals and including high-energy phases.

  3. Role of intracanalicular volumetric and dosimetric parameters on hearing preservation after vestibular schwannoma radiosurgery

    International Nuclear Information System (INIS)

    Massager, Nicolas; Nissim, Ouzi; Delbrouck, Carine; Devriendt, Daniel; David, Philippe; Desmedt, Francoise; Wikler, David; Hassid, Sergio; Brotchi, Jacques; Levivier, Marc

    2006-01-01

    Purpose: To analyze the relationship between hearing preservation after gamma knife radiosurgery (GKR) for vestibular schwannoma (VS) and some volumetric and dosimetric parameters of the intracanalicular components of VS. Methods and Materials: This study included 82 patients with a VS treated by GKR; all patients had no NF2 disease, a Gardner-Robertson hearing class 1-4 before treatment, a marginal dose of 12 Gy, and a radiologic and audiologic follow-up ≥1 year post-GKR. The volume of both the entire tumor and the intracanalicular part of the tumor and the mean and integrated dose of these two volumes were correlated to the auditory outcomes of patients. Results: At last hearing follow-up, 52 patients had no hearing worsening, and 30 patients had an increase of ≥1 class on Gardner-Robertson classification. We found that hearing preservation after GKR is significantly correlated with the intracanalicular tumor volume, as well as with the integrated dose delivered to the intracanalicular tumor volume. Conclusions: Some volumetric and dosimetric parameters of the intracanalicular part of the tumor influence hearing preservation after GKR of VS. Consequently, we advise the direct treatment of patients with preserved functional hearing and a VS including a small intracanalicular volume

  4. Fractionated Stereotactic Radiotherapy of Vestibular Schwannomas Accelerates Hearing Loss

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    Rasmussen, Rune, E-mail: rune333@gmail.com [Department of Neurosurgery, Rigshospitalet, Copenhagen (Denmark); Claesson, Magnus [Department of Neurosurgery, Rigshospitalet, Copenhagen (Denmark); Stangerup, Sven-Eric [Ear, Nose, and Throat Department, Rigshospitalet, Copenhagen (Denmark); Roed, Henrik [Department of Radiation Oncology, Rigshospitalet, Copenhagen (Denmark); Christensen, Ib Jarle [Finsen Laboratory, Rigshospitalet, Copenhagen (Denmark); Caye-Thomasen, Per [Ear, Nose, and Throat Department, Rigshospitalet, Copenhagen (Denmark); Juhler, Marianne [Department of Neurosurgery, Rigshospitalet, Copenhagen (Denmark)

    2012-08-01

    Objective: To evaluate long-term tumor control and hearing preservation rates in patients with vestibular schwannoma treated with fractionated stereotactic radiotherapy (FSRT), comparing hearing preservation rates to an untreated control group. The relationship between radiation dose to the cochlea and hearing preservation was also investigated. Methods and Materials: Forty-two patients receiving FSRT between 1997 and 2008 with a minimum follow-up of 2 years were included. All patients received 54 Gy in 27-30 fractions during 5.5-6.0 weeks. Clinical and audiometry data were collected prospectively. From a 'wait-and-scan' group, 409 patients were selected as control subjects, matched by initial audiometric parameters. Radiation dose to the cochlea was measured using the original treatment plan and then related to changes in acoustic parameters. Results: Actuarial 2-, 4-, and 10-year tumor control rates were 100%, 91.5%, and 85.0%, respectively. Twenty-one patients had serviceable hearing before FSRT, 8 of whom (38%) retained serviceable hearing at 2 years after FSRT. No patients retained serviceable hearing after 10 years. At 2 years, hearing preservation rates in the control group were 1.8 times higher compared with the group receiving FSRT (P=.007). Radiation dose to the cochlea was significantly correlated to deterioration of the speech reception threshold (P=.03) but not to discrimination loss. Conclusion: FSRT accelerates the naturally occurring hearing loss in patients with vestibular schwannoma. Our findings, using fractionation of radiotherapy, parallel results using single-dose radiation. The radiation dose to the cochlea is correlated to hearing loss measured as the speech reception threshold.

  5. Fractionated Stereotactic Radiotherapy of Vestibular Schwannomas Accelerates Hearing Loss

    International Nuclear Information System (INIS)

    Rasmussen, Rune; Claesson, Magnus; Stangerup, Sven-Eric; Roed, Henrik; Christensen, Ib Jarle; Cayé-Thomasen, Per; Juhler, Marianne

    2012-01-01

    Objective: To evaluate long-term tumor control and hearing preservation rates in patients with vestibular schwannoma treated with fractionated stereotactic radiotherapy (FSRT), comparing hearing preservation rates to an untreated control group. The relationship between radiation dose to the cochlea and hearing preservation was also investigated. Methods and Materials: Forty-two patients receiving FSRT between 1997 and 2008 with a minimum follow-up of 2 years were included. All patients received 54 Gy in 27-30 fractions during 5.5-6.0 weeks. Clinical and audiometry data were collected prospectively. From a “wait-and-scan” group, 409 patients were selected as control subjects, matched by initial audiometric parameters. Radiation dose to the cochlea was measured using the original treatment plan and then related to changes in acoustic parameters. Results: Actuarial 2-, 4-, and 10-year tumor control rates were 100%, 91.5%, and 85.0%, respectively. Twenty-one patients had serviceable hearing before FSRT, 8 of whom (38%) retained serviceable hearing at 2 years after FSRT. No patients retained serviceable hearing after 10 years. At 2 years, hearing preservation rates in the control group were 1.8 times higher compared with the group receiving FSRT (P=.007). Radiation dose to the cochlea was significantly correlated to deterioration of the speech reception threshold (P=.03) but not to discrimination loss. Conclusion: FSRT accelerates the naturally occurring hearing loss in patients with vestibular schwannoma. Our findings, using fractionation of radiotherapy, parallel results using single-dose radiation. The radiation dose to the cochlea is correlated to hearing loss measured as the speech reception threshold.

  6. Effectiveness of vestibular exercise in acute vertigo

    International Nuclear Information System (INIS)

    Hashim, N.D.; Abdullah, A.; Ami, M.; Rahman, R.A.

    2015-01-01

    To evaluate effectiveness of vestibular exercises in acute vertigo. 45 patients with acute vertigo were divided into 2 groups; 23 in study group (SG) and 22 in control group (CG). All patients were given tablet betahistine 24 mg twice daily as basic medical treatment and tablet Stemetil 5mg as a rescue. Those in SG also received vestibular exercise. Assessment was done using validated questionnaires, neuro-otology tests and individual diaries. Results : Intragroup comparison of intensity of symptoms showed a significant improvement from baseline, 3-month and 6-month visit with p<0.001. While intergroup comparison showed reduction of scores in both groups and which was greater in SG at 6 months visit. An improvement of neuro-otology tests was seen in all five tests whereby the Romber test, Unterberger-Fukuda test and spontaneous nystagmus test showed earlier improvement in SG at 3-month visit than CG. The SG also recovered faster and used lesser medication. 30.4% patients in SG were asymptomatic as early as first to third week after intervention. The number of rescue medications required in each group lessened towards the end of study. By week 7, 56.3% of SG and 43.8% of CG needed no rescue medication. (author)

  7. Cross-Modal Calibration of Vestibular Afference for Human Balance.

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    Martin E Héroux

    Full Text Available To determine how the vestibular sense controls balance, we used instantaneous head angular velocity to drive a galvanic vestibular stimulus so that afference would signal that head movement was faster or slower than actual. In effect, this changed vestibular afferent gain. This increased sway 4-fold when subjects (N = 8 stood without vision. However, after a 240 s conditioning period with stable balance achieved through reliable visual or somatosensory cues, sway returned to normal. An equivalent galvanic stimulus unrelated to sway (not driven by head motion was equally destabilising but in this situation the conditioning period of stable balance did not reduce sway. Reflex muscle responses evoked by an independent, higher bandwidth vestibular stimulus were initially reduced in amplitude by the galvanic stimulus but returned to normal levels after the conditioning period, contrary to predictions that they would decrease after adaptation to increased sensory gain and increase after adaptation to decreased sensory gain. We conclude that an erroneous vestibular signal of head motion during standing has profound effects on balance control. If it is unrelated to current head motion, the CNS has no immediate mechanism of ignoring the vestibular signal to reduce its influence on destabilising balance. This result is inconsistent with sensory reweighting based on disturbances. The increase in sway with increased sensory gain is also inconsistent with a simple feedback model of vestibular reflex action. Thus, we propose that recalibration of a forward sensory model best explains the reinterpretation of an altered reafferent signal of head motion during stable balance.

  8. Impedance pattern of vaginal and vestibular mucosa in cyclic goats

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    Ivo Křivánek

    2008-01-01

    Full Text Available The changes of vaginal and vestibular impedance during the oestrous cycle in goats were examined. The onset of oestrus was teased with a buck once a day during the experiment. Impedance was mea­sured by a four-terminal method. The vaginal impedance was recorded under slight pressure of electrodes to the vaginal dorsal wall at the cervix. The vestibular impedance was recorded under slight pressure of electrodes to the vestibular dorsal wall 5 cm from the vulva and at the vulva. The im­pe­dan­ce was measured once a day from 4 days before the expected oestrus to 6 days after onset of oestrus. The vaginal impedance at the cervix decreased during pro-oestrus (P < 0.01 and increased du­ring oestrus (P < 0.01. The vestibular impedance 5 cm from the vulva decreased during pro-oestrus (P < 0.01 and increased after oestrus (P < 0.01. The decrease of vaginal impedance during peri-oestrus was nearly twofold in comparison with the vestibular impedance 5 cm from the vulva. No sig­ni­fi­cant decrease of the vestibular impedance at the vulva was found during the oestrous cycle. The results indicate that the vaginal impedance at the cervix and vestibular impedance 5 cm from the vulva measured by means of a four-terminal method during the oestrous cycle display cyclic changes that are closely related to the oestrous behaviour of goats.

  9. Vestibular disorders among adults in a tertiary hospital in Lagos, Nigeria.

    Science.gov (United States)

    Somefun, O A; Giwa, O S; Bamgboye, B A; Okeke-Igbokwe, I Irene; Azeez, A A Abdul

    2010-10-01

    Dizziness is not an uncommon complaint in the Otolaryngological clinics among other symptoms. To a large number of practitioners, the treatment of dizziness remains the same irrespective of the etiology, i.e., anti-vertiginous drugs. The objective of this study was to document the evaluation, causes and treatment of vestibular disorders among our patients. The design includes descriptive prospective study conducted in the Oto-rhino-laryngology and Orthopedic Clinics of Lagos University Teaching Hospital, Lagos and Nigerian Army Audiological Centre, 68 Nigerian Army Reference Hospital, Yaba, Lagos, Nigeria. Adult patients referred to the audiology clinic for dizziness had detailed history obtained by using structured questionnaire. General physical and neuro-otological examinations were done. Clinical diagnoses were made on standardized criteria. The patients had hearing evaluation, videonystagmography (VNG) evaluation using infrared videonystagmography system. X-ray of the cervical spine and computerized tomogram scan of internal auditory meatus and brain when indicated were done. A total of 102 patients were seen with age range between 21 and 90 years. Thirty patients (29.4%) recorded average duration of episode of vertiginous attacks in seconds, 69 (67.6%) recorded within minutes to hours and 3 (2.9%) with no definite pattern. Clinical signs on neuro-otological examination were elicited on 39 (38.2%) of the patients while on VNG the vestibular subtest mainly caloric test was abnormal unilaterally and bilaterally in 47 (46.1%) while with the oculomotor subtests, smooth pursuit tests were abnormal in 5 (6.9%), saccade tests were abnormal in 8 (7.8%) and OPK were abnormal in 9 (8.8%). Peripheral vestibular disorders are common of which benign paroxysmal positional vertigo (BPPV) was seen in 29 (28.4%), Meniere's disease in 22 (21.6%), recurrent vestibulopathy in 20 (19.6%), cervical vertigo in 18 (17.6%), psychogenic vertigo in 2 (2%), vestibular schwannoma

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

    Science.gov (United States)

    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.

  11. Improved results for vestibular schwannoma radiosurgery

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    Flickinger, J C; Kondziolka, D; Pollock, B; Lunsford, L D

    1995-07-01

    PURPOSE/OBJECTIVE: Treatment techniques in radiosurgery have changed since 1987. We reviewed patients who received radiosurgery for vestibular schwannoma to identify these changes and to investigate any differences in tumor control and complications. MATERIALS and METHODS: One hundred thirty-eight unilateral vestibular schwannoma patients with a minimum follow-up of two years after treatment with gamma knife radiosurgery between 1987 and 1992 were analyzed. The early treatment group consisted of 55 patients treated between 1987-1989 (median: tumor volume 3.63 cc, Dmin 18.1 Gy, Dmax 35.4 Gy, isocenters 2.3, follow-up 50.4 mos.). The later treatment group consisted of 83 patients treated between 1990-1992 (median: tumor volume 3.81 cc, Dmin 16.0 Gy, Dmax 31.6 Gy, isocenters 4.7, follow-up 35.8 mos.) RESULTS: Clinical tumor recurrence requiring surgical intervention occurred in one patient in each group. The overall actuarial clinical tumor control rate was 98%. Slight increases in tumor size (1 to 2 mm) were identified in five other patients not requiring intervention, because of no further tumor growth (n=4) or shrinkage (n=1). This led to an overall radiologic tumor control rate of 92% (not significantly different in either group). Compared to the early treatment group, the incidence of facial neuropathy (temporary or permanent) decreased in the later group (49% vs. 11%, p < 0.0001), as did trigeminal neuropathy (40% vs. 8%, p < 0.0001). Serviceable hearing preservation improved only slightly in the later group (27% vs. 40%, p = 0.70). CONCLUSION: We document a significant decrease in the morbidity of vestibular schwannoma radiosurgery over this time period with no decrease in the high rate of tumor control. This improvement is attributed to a) better conformal dose-planning with stereotactic MRI rather than CT, b) an increase in the number of isocenters used, and c) a reduction in the average dose administered by 2 Gy.

  12. Depolarization-induced release of amino acids from the vestibular nuclear complex.

    Science.gov (United States)

    Godfrey, Donald A; Sun, Yizhe; Frisch, Christopher; Godfrey, Matthew A; Rubin, Allan M

    2012-04-01

    There is evidence from immunohistochemistry, quantitative microchemistry, and pharmacology for several amino acids as neurotransmitters in the vestibular nuclear complex (VNC), including glutamate, γ-aminobutyrate (GABA), and glycine. However, evidence from measurements of release has been limited. The purpose of this study was to measure depolarization-stimulated calcium-dependent release of amino acids from the VNC in brain slices. Coronal slices containing predominantly the VNC were prepared from rats and perfused with artificial cerebrospinal fluid (ACSF) in an interface chamber. Fluid was collected from the chamber just downstream from the VNC using a microsiphon. Depolarization was induced by 50 mM potassium in either control calcium and magnesium concentrations or reduced calcium and elevated magnesium. Amino acid concentrations in effluent fluid were measured by high performance liquid chromatography. Glutamate release increased fivefold during depolarization in control calcium concentration and twofold in low calcium/high magnesium. These same ratios were 6 and 1.5 for GABA, 2 and 1.3 for glycine, and 2 and 1.5 for aspartate. Differences between release in control and low calcium/high magnesium ACSF were statistically significant for glutamate, GABA, and glycine. Glutamine release decreased during and after depolarization, and taurine release slowly increased. No evidence for calcium-dependent release was found for serine, glutamine, alanine, threonine, arginine, taurine, or tyrosine. Our results support glutamate and GABA as major neurotransmitters in the VNC. They also support glycine as a neurotransmitter and some function for taurine.

  13. Cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS) with chronic cough and preserved muscle stretch reflexes: evidence for selective sparing of afferent Ia fibres.

    Science.gov (United States)

    Infante, Jon; García, Antonio; Serrano-Cárdenas, Karla M; González-Aguado, Rocío; Gazulla, José; de Lucas, Enrique M; Berciano, José

    2018-04-25

    The aim of this study was to describe five patients with cerebellar ataxia, neuropathy and vestibular areflexia syndrome (CANVAS) with chronic cough and preserved limb muscle stretch reflexes. All five patients were in the seventh decade of age, their gait imbalance having been initiated in the fifth decade. In four patients cough antedated gait imbalance between 15 and 29 years; cough was spasmodic and triggered by variable factors. Established clinical picture included severe hypopallesthesia predominating in the lower limbs with postural imbalance, and variable degree of cerebellar axial and appendicular ataxia, dysarthria and horizontal gaze-evoked nystagmus. Upper- and lower-limb tendon jerks were preserved, whereas jaw jerk was absent. Vestibular function testing showed bilateral impairment of the vestibulo-ocular reflex. Nerve conduction studies demonstrated normal motor conduction parameters and absence or severe attenuation of sensory nerve action potentials. Somatosensory evoked potentials were absent or severely attenuated. Biceps and femoral T-reflex recordings were normal, while masseter reflex was absent or attenuated. Sympathetic skin responses were normal. Cranial MRI showed vermian and hemispheric cerebellar atrophy predominating in lobules VI, VII and VIIa. We conclude that spasmodic cough may be an integral part of the clinical picture in CANVAS, antedating the appearance of imbalance in several decades and that sparing of muscle spindle afferents (Ia fibres) is probably the pathophysiological basis of normoreflexia.

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

    Science.gov (United States)

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

    2017-09-01

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

  15. The minimal ice water caloric test compared with established vestibular caloric test procedures.

    Science.gov (United States)

    Schmäl, Frank; Lübben, Björn; Weiberg, Kerstin; Stoll, Wolfgang

    2005-01-01

    Caloric testing of the vestibular labyrinth is usually performed by classical caloric test procedures (CCTP) using water warmed to 30 degrees C and 44 degrees C. Ice water irrigation (4 degrees C) is usually not performed, although it might be useful as a bedside test. To verify the validity of the Minimal Ice Water Caloric Test (MIWCT), comparative video-oculographic investigations were performed in 22 healthy subjects using ice water (0.5 ml, 1.0 ml, 2 ml), CCTP, and cold air (27 degrees C). Frequency, amplitude, slow phase velocity (SPV), the onset, and the duration of nystagmus were documented. After addition of three ice cubes, the temperature of conventional tap water (16 degrees C) fell within 13 min to 4 degrees C. In pessimum position the subjects demonstrated no nystagmus response. Compared to CCTP, MIWCT was associated with a significantly later onset of nystagmus and a significant prolongation of the nystagmus reaction. In contrast to air stimulation (27 degrees C), a significant Spearman's correlation was noted between MIWCT (1 and 2 ml) and established CCTP in respect of essential nystagmus parameters (frequency, amplitude and SPV). Furthermore, MIWCT (0.5 and 1 ml) showed a higher sensitivity and specificity with regard to the detection of canal paresis based on Jongkees' formula compared to stimulation with air 27 degrees C. Thus, MIWCT appears to be a suitable procedure for bedside investigation of vestibular function outside the vestibular laboratory, e.g. in a hospital ward, where bedridden patients with vertigo occasionally require vestibular testing.

  16. Pulsed infrared radiation excites cultured neonatal spiral and vestibular ganglion neurons by modulating mitochondrial calcium cycling.

    Science.gov (United States)

    Lumbreras, Vicente; Bas, Esperanza; Gupta, Chhavi; Rajguru, Suhrud M

    2014-09-15

    Cochlear implants are currently the most effective solution for profound sensorineural hearing loss, and vestibular prostheses are under development to treat bilateral vestibulopathies. Electrical current spread in these neuroprostheses limits channel independence and, in some cases, may impair their performance. In comparison, optical stimuli that are spatially confined may result in a significant functional improvement. Pulsed infrared radiation (IR) has previously been shown to elicit responses in neurons. This study analyzes the response of neonatal rat spiral and vestibular ganglion neurons in vitro to IR (wavelength = 1,863 nm) using Ca(2+) imaging. Both types of neurons responded consistently with robust intracellular Ca(2+) ([Ca(2+)]i) transients that matched the low-frequency IR pulses applied (4 ms, 0.25-1 pps). Radiant exposures of ∼637 mJ/cm(2) resulted in continual neuronal activation. Temperature or [Ca(2+)] variations in the media did not alter the IR-evoked transients, ruling out extracellular Ca(2+) involvement or primary mediation by thermal effects on the plasma membrane. While blockage of Na(+), K(+), and Ca(2+) plasma membrane channels did not alter the IR-evoked response, blocking of mitochondrial Ca(2+) cycling with CGP-37157 or ruthenium red reversibly inhibited the IR-evoked [Ca(2+)]i transients. Additionally, the magnitude of the IR-evoked transients was dependent on ryanodine and cyclopiazonic acid-dependent Ca(2+) release. These results suggest that IR modulation of intracellular calcium cycling contributes to stimulation of spiral and vestibular ganglion neurons. As a whole, the results suggest selective excitation of neurons in the IR beam path and the potential of IR stimulation in future auditory and vestibular prostheses. Copyright © 2014 the American Physiological Society.

  17. Vestibular Stimulation and Auditory Perception in Children with Attention Deficit Hyperactivity Disorder

    Directory of Open Access Journals (Sweden)

    Azin Salamati

    2014-09-01

    Full Text Available Objectives: Rehabilitation strategies play a pivotal role in reliving the inappropriate behaviors and improving children's performance during school. Concentration and visual and auditory comprehension in children are crucial to effective learning and have drawn interest from researchers and clinicians. Vestibular function deficits usually cause high level of alertness and vigilance, and problems in maintaining focus, paying selective attention, and altering in precision and attention to the stimulus. The aim of this study is to investigate the correlation between vestibular stimulation and auditory perception in children with attention deficit hyperactivity disorder. Methods: Totally 30 children aged from 7 to 12 years with attention deficit hyperactivity disorder participated in this study. They were assessed based on the criteria of diagnostic and statistical manual of mental disorders. After obtaining guardian and parental consent, they were enrolled and randomly matched on age to two groups of intervention and control. Integrated visual and auditory continuous performance test was carried out as a pre-test. Those in the intervention group received vestibular stimulation during the therapy sessions, twice a week for 10 weeks. At the end the test was done to both groups as post-test. Results: The pre-and post-test scores were measured and compared the differences between means for two subject groups. Statistical analyses found a significant difference for the mean differences regarding auditory comprehension improvement. Discussion: The findings suggest that vestibular training is a reliable and powerful option treatment for attention deficit hyperactivity disorder especially along with other trainings, meaning that stimulating the sense of balance highlights the importance of interaction between inhabitation and cognition.

  18. PREHAB vs. REHAB - presurgical treatment in vestibular schwannoma surgery enhances recovery of postural control better than postoperative rehabilitation: Retrospective case series.

    Science.gov (United States)

    Tjernström, Fredrik; Fransson, Per-Anders; Kahlon, Babar; Karlberg, Mikael; Lindberg, Sven; Siesjö, Peter; Magnusson, Måns

    2018-01-01

    To evaluate post-surgical postural stability when treating patients with remaining vestibular function with intratympanic gentamicin (PREHAB) prior to schwannoma surgery. 44 consecutive patients with some form remaining vestibular function scheduled for vestibular schwannoma surgery. 20 were medically deafferented with intratympanic gentamicin before surgery and 24 were not. Both groups were of the same age, had the same tumor size, same type of surgery, and same perioperative sensory rehabilitation (training exercises), and no surgical complications. Postural stability measured as energy expenditure while standing on a force platform during vibratory stimulation of the calf muscles, performed prior to surgery (or gentamicin treatment) and 6 months after surgery. Patients pretreated with gentamicin had significantly better postural stability at the time for follow-up (p postural challenge (p control their stability (p postural control system benefited from a better short-term (adaptation) and long-term (habituation) recovery, when experiencing a postural challenge or resolving a sensory conflict. The benefits could be attributed to; active and continuous motor learning as the vestibular function slowly attenuates; no concomitant central nervous dysfunction due to effects from neurosurgery, thus allowing time for a separate unimpeded recovery process with more limited challenges and objectives; and the initiation and certain progression of sensory reweighting processes allowed prior to surgery. In contrast, worse compensation could be due to; immobilization from nausea after surgery, harmful amount of stress and cognitive dysfunction from the combination of surgical and sensory trauma and an abrupt vestibular deafferentation and its consequences on sensory reweighting.

  19. Vestibular schwannomas: Accuracy of tumor volume estimated by ice cream cone formula using thin-sliced MR images.

    Science.gov (United States)

    Ho, Hsing-Hao; Li, Ya-Hui; Lee, Jih-Chin; Wang, Chih-Wei; Yu, Yi-Lin; Hueng, Dueng-Yuan; Ma, Hsin-I; Hsu, Hsian-He; Juan, Chun-Jung

    2018-01-01

    We estimated the volume of vestibular schwannomas by an ice cream cone formula using thin-sliced magnetic resonance images (MRI) and compared the estimation accuracy among different estimating formulas and between different models. The study was approved by a local institutional review board. A total of 100 patients with vestibular schwannomas examined by MRI between January 2011 and November 2015 were enrolled retrospectively. Informed consent was waived. Volumes of vestibular schwannomas were estimated by cuboidal, ellipsoidal, and spherical formulas based on a one-component model, and cuboidal, ellipsoidal, Linskey's, and ice cream cone formulas based on a two-component model. The estimated volumes were compared to the volumes measured by planimetry. Intraobserver reproducibility and interobserver agreement was tested. Estimation error, including absolute percentage error (APE) and percentage error (PE), was calculated. Statistical analysis included intraclass correlation coefficient (ICC), linear regression analysis, one-way analysis of variance, and paired t-tests with P ice cream cone method, and ellipsoidal and Linskey's formulas significantly reduced the APE to 11.0%, 10.1%, and 12.5%, respectively (all P ice cream cone method and other two-component formulas including the ellipsoidal and Linskey's formulas allow for estimation of vestibular schwannoma volume more accurately than all one-component formulas.

  20. The role of vestibular and support-tactile-proprioceptive inputs in visual-manual tracking

    Science.gov (United States)

    Kornilova, Ludmila; Naumov, Ivan; Glukhikh, Dmitriy; Khabarova, Ekaterina; Pavlova, Aleksandra; Ekimovskiy, Georgiy; Sagalovitch, Viktor; Smirnov, Yuriy; Kozlovskaya, Inesa

    Sensorimotor disorders in weightlessness are caused by changes of functioning of gravity-dependent systems, first of all - vestibular and support. The question arises, what’s the role and the specific contribution of the support afferentation in the development of observed disorders. To determine the role and effects of vestibular, support, tactile and proprioceptive afferentation on characteristics of visual-manual tracking (VMT) we conducted a comparative analysis of the data obtained after prolonged spaceflight and in a model of weightlessness - horizontal “dry” immersion. Altogether we examined 16 Russian cosmonauts before and after prolonged spaceflights (129-215 days) and 30 subjects who stayed in immersion bath for 5-7 days to evaluate the state of the vestibular function (VF) using videooculography and characteristics of the visual-manual tracking (VMT) using electrooculography & joystick with biological visual feedback. Evaluation of the VF has shown that both after immersion and after prolonged spaceflight there were significant decrease of the static torsional otolith-cervical-ocular reflex (OCOR) and simultaneous significant increase of the dynamic vestibular-cervical-ocular reactions (VCOR) with a revealed negative correlation between parameters of the otoliths and canals reactions, as well as significant changes in accuracy of perception of the subjective visual vertical which correlated with changes in OCOR. Analyze of the VMT has shown that significant disorders of the visual tracking (VT) occurred from the beginning of the immersion up to 3-4 day after while in cosmonauts similar but much more pronounced oculomotor disorders and significant changes from the baseline were observed up to R+9 day postflight. Significant changes of the manual tracking (MT) were revealed only for gain and occurred on 1 and 3 days in immersion while after spaceflight such changes were observed up to R+5 day postflight. We found correlation between characteristics

  1. Balancing awareness: Vestibular signals modulate visual consciousness in the absence of awareness.

    Science.gov (United States)

    Salomon, Roy; Kaliuzhna, Mariia; Herbelin, Bruno; Blanke, Olaf

    2015-11-01

    The processing of visual and vestibular information is crucial for perceiving self-motion. Visual cues, such as optic flow, have been shown to induce and alter vestibular percepts, yet the role of vestibular information in shaping visual awareness remains unclear. Here we investigated if vestibular signals influence the access to awareness of invisible visual signals. Using natural vestibular stimulation (passive yaw rotations) on a vestibular self-motion platform, and optic flow masked through continuous flash suppression (CFS) we tested if congruent visual-vestibular information would break interocular suppression more rapidly than incongruent information. We found that when the unseen optic flow was congruent with the vestibular signals perceptual suppression as quantified with the CFS paradigm was broken more rapidly than when it was incongruent. We argue that vestibular signals impact the formation of visual awareness through enhanced access to awareness for congruent multisensory stimulation. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Inner ear malformations in siblings presenting with vestibular ...

    African Journals Online (AJOL)

    Any child presenting with vestibular symptoms should be referred for an audiological assessment. I R T Butler, MMed ... rhythmically to music. The patient was ... was enrolled in an intensive speech therapy programme at age 2 years 7 months.

  3. Distinct spontaneous shrinkage of a sporadic vestibular schwannoma

    DEFF Research Database (Denmark)

    Huang, Xiaowen; Cayé-Thomasen, Per; Stangerup, Sven-Eric

    2013-01-01

    on "shrinkage" or "negative growth" or "regression" or "involution" of the tumor were selected, and the contents on the rate, extent and mechanism of spontaneous tumor shrinkage were extracted and reviewed. The reported rate of spontaneous shrinkage of vestibular schwannoma is 5-10% of patients managed......We present a case with outspoken spontaneous vestibular schwannoma shrinkage and review the related literature. The patient was initially diagnosed with a left-sided, intrameatal vestibular schwannoma, which subsequently grew into the cerebello-pontine angle (CPA), followed by total shrinkage...... of the CPA component without any intervention over a 12-year observation period. The literature on spontaneous tumor shrinkage was retrieved by searching the subject terms "vestibular schwannoma, conservative management" in PubMed/MEDLINE database, without a time limit. Of the published data, the articles...

  4. Caloric vestibular stimulation in aphasic syndrome

    Directory of Open Access Journals (Sweden)

    David eWilkinson

    2013-12-01

    Full Text Available Caloric vestibular stimulation (CVS is commonly used to diagnose brainstem disorder but its therapeutic application is much less established. Based on the finding that CVS increases blood flow to brain structures associated with language and communication, we assessed whether the procedure has potential to relieve symptoms of post-stroke aphasia. Three participants, each presenting with chronic, unilateral lesions to the left hemisphere, were administered daily CVS for 4 consecutive weeks. Relative to their pre-treatment baseline scores, two of the three participants showed significant improvement on both picture and responsive naming at immediate and one-week follow-up. One of these participants also showed improved sentence repetition, and another showed improved auditory word discrimination. No adverse reactions were reported. These data provide the first, albeit tentative, evidence that CVS may relieve expressive and receptive symptoms of aphasia. A larger, sham-controlled study is now needed to further assess efficacy.

  5. Vestibular syndrome in giant anteater (Myrmecophaga tridactyla)

    OpenAIRE

    Oliveira, Fabricio Singaretti de; Gubulin Carvalho, Paula Fernanda; Bueno de Camargo, Mauro Henrique; Delfini, Aline; Martins, Leandro [UNESP

    2009-01-01

    A síndrome vestibular é uma afecção bem descrita em animais domésticos e pouco relatada em selvagens. Este relato descreveu essa afecção de origem central em uma fêmea adulta de tamanduá-bandeira (Myrmecophaga tridactyla), caquética, apresentando deambulação em círculos, hipermetria extensora nos membros torácicos, desvio da cabeça e nistagmo espontâneo horizontal e posicional vertical. O animal foi alimentado por sonda oral, 2x/dia e instituiu-se tratamento com dexametasona subcutânea na dos...

  6. Prognostic significance of electrophysiological tests for facial nerve outcome in vestibular schwannoma surgery.

    Science.gov (United States)

    van Dinther, J J S; Van Rompaey, V; Somers, T; Zarowski, A; Offeciers, F E

    2011-01-01

    To assess the prognostic significance of pre-operative electrophysiological tests for facial nerve outcome in vestibular schwannoma surgery. Retrospective study design in a tertiary referral neurology unit. We studied a total of 123 patients with unilateral vestibular schwannoma who underwent microsurgical removal of the lesion. Nine patients were excluded because they had clinically abnormal pre-operative facial function. Pre-operative electrophysiological facial nerve function testing (EPhT) was performed. Short-term (1 month) and long-term (1 year) post-operative clinical facial nerve function were assessed. When pre-operative facial nerve function, evaluated by EPhT, was normal, the outcome from clinical follow-up at 1-month post-operatively was excellent in 78% (i.e. HB I-II) of patients, moderate in 11% (i.e. HB III-IV), and bad in 11% (i.e. HB V-VI). After 1 year, 86% had excellent outcomes, 13% had moderate outcomes, and 1% had bad outcomes. Of all patients with normal clinical facial nerve function, 22% had an abnormal EPhT result and 78% had a normal result. No statistically significant differences could be observed in short-term and long-term post-operative facial function between the groups. In this study, electrophysiological tests were not able to predict facial nerve outcome after vestibular schwannoma surgery. Tumour size remains the best pre-operative prognostic indicator of facial nerve function outcome, i.e. a better outcome in smaller lesions.

  7. Timing of neuron development in the rodent vestibular system

    Science.gov (United States)

    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.

  8. Morphological analysis of the vestibular aqueduct by computerized tomography images

    International Nuclear Information System (INIS)

    Marques, Sergio Ricardo; Smith, Ricardo Luiz; Isotani, Sadao; Alonso, Luis Garcia; Anadao, Carlos Augusto; Prates, Jose Carlos; Lederman, Henrique Manoel

    2007-01-01

    Objective: In the last two decades, advances in the computerized tomography (CT) field revise the internal and medium ear evaluation. Therefore, the aim of this study is to analyze the morphology and morphometric aspects of the vestibular aqueduct on the basis of computerized tomography images (CTI). Material and method: Computerized tomography images of vestibular aqueducts were acquired from patients (n = 110) with an age range of 1-92 years. Thereafter, from the vestibular aqueducts images a morphometric analysis was performed. Through a computerized image processing system, the vestibular aqueduct measurements comprised of its area, external opening, length and the distance from the vestibular aqueduct to the internal acoustic meatus. Results: The morphology of the vestibular aqueduct may be funnel-shaped, filiform or tubular and the respective proportions were found to be at 44%, 33% and 22% in children and 21.7%, 53.3% and 25% in adults. The morphometric data showed to be of 4.86 mm 2 of area, 2.24 mm of the external opening, 4.73 mm of length and 11.88 mm of the distance from the vestibular aqueduct to the internal acoustic meatus, in children, and in adults it was of 4.93 mm 2 , 2.09 mm, 4.44 mm, and 11.35 mm, respectively. Conclusions: Computerized tomography showed that the vestibular aqueduct presents high morphological variability. The morphometric analysis showed that the differences found between groups of children and adults or between groups of both genders were not statistically significant

  9. Quality of life in patients after vestibular Schwannoma surgery

    OpenAIRE

    Hajná, Barbora

    2011-01-01

    TVestibular schwannoma is a benign tumor that arises from the Schwann cells of the vestibular nerve. Unilateral hearing loss, tinnitus, facial and trigeminal dysfunction and vertigo are the most common symptoms. Surgical removal of the tumor is one of the treatment modalities of this disease. Surgical excision usually involves the complete vestibular nerve resection and there is also a risk of cochlear and facial nerve lesion. This thesis deals with changes in quality of life in patients afte...

  10. Prognostic Factors of Balance Quality After Transpetrosal Vestibular Schwannoma Microsurgery: An Instrumentally and DHI-based Prospective Cohort Study of 48 Patients.

    Science.gov (United States)

    Thomeer, Hans; Bonnard, Damien; Franco-Vidal, Valérie; Porez, Florence; Darrouzet, Patricia; Liguoro, Dominique; Darrouzet, Vincent

    2015-06-01

    To evaluate short- and mid-term level of imbalance after vestibular schwannoma (VS) microsurgery by the transpetrosal approach, to search for factors predictive of vestibular compensation, and to determine which patient categories need a postoperative vestibular rehabilitation program. Prospective cohort study at a tertiary referral center. Between 2010 and 2011, patients aged 18 to 75 operated on for VS by transpetrosal approaches were included. VS was characterized by its size (Koos classification) and the presence or not of a cystic component. Hearing was classified according to the Gardner Robertson grading. The preoperative workup included an audiogram, computerized video nystagmography (VNG) with caloric testing, gaze study, rotatory tests, click-evoked cervical vestibular evoked myogenic potential measurements (cVEMPs), and subjective visual vertical test. Patients were asked to complete a Dizziness Handicap Inventory (DHI). Postoperatively, patients were reevaluated on D7 (clinical status), D90 (VNG and DHI), and D180 (DHI). Timing and duration of vestibular rehabilitation were also recorded. Forty-eight patients were included. Preoperatively, 77% experienced mild instability problems with a mean DHI score of 14.1 (range 4-32). Postoperatively, 71% reported stable or even improved perceived stability. Mean DHI scores were 28.1 on D90 and 19.8 on D180. Serviceable hearing, cystic transformation, normal cVEMPs, diplopia, and vestibular syndrome on D7 were found to be predictive of worse equilibrium outcome than when absent. A preoperative caloric deficit greater than 75% seemed to be a good prognostic factor. Vestibular rehabilitation was conducted in 56% of patients. Starting it early (<1 mo) seemed to be beneficial for final equilibrium outcome. VS microsurgery provides good stability results. Some preoperative parameters may be predictive of worse or improved balance recovery, as is clinical status on D7.

  11. Isolation and culture of adult mouse vestibular nucleus neurons

    Science.gov (United States)

    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.

  12. Precerebellar and vestibular nuclei of the short-beaked echidna (Tachyglossus aculeatus).

    Science.gov (United States)

    Ashwell, K W S; Paxinos, G; Watson, C R R

    2007-09-01

    The monotremes are a unique group of living mammals, which diverged from the line leading to placental mammals at least 125 million years ago. We have examined the organization of pontine, inferior olivary, lateral reticular and vestibular nuclei in the brainstem of the short-beaked echidna (Tachyglossus aculeatus) to determine if the cyto- and chemoarchitecture of these nuclei are similar to that in placental mammals and marsupials. We have used Nissl staining in conjunction with enzyme-histochemistry for acetylcholinesterase, cytochrome oxidase and NADPH diaphorase as well as immunohistochemistry for non-phosphorylated neurofilament protein (SMI-32 antibody) and calcium binding proteins (parvalbumin, calbindin, calretinin). Homologies could be established between the arch shaped inferior olivary complex of the echidna and the principal, dorsal and medial accessory subdivisions of the therian inferior olivary complex. The pontine nuclei of the echidna included basilar and reticulotegmental components with similar cyto- and chemarchitectural features to therians and there were magnocellular and subtrigeminal components of the lateral reticular nucleus, also as seen in therians. Subdivisions and chemoarchitecture of the vestibular complex of the echidna were both similar to that region in rodents. In all three precerebellar nuclear groups studied and in the vestibular nucleus organization, the cyto- and chemoarchitecture of the echidna was very similar to that seen in therian mammals and no "primitive" or "reptilian" features were evident.

  13. [Results of videonystagmographic (VNG) analysis in vestibular post-traumatic pathology].

    Science.gov (United States)

    Armato, E; Ferri, E; García Purrinos, F

    2001-10-01

    From February 1998 to July 1999, 569 patients affected by vestibular disorders--following a whiplash injury and/or a cranial trauma--were studied. The neuro-otological examination included a tonal audiometry, brain stem auditory evoked potentials, clinical and instrumental vestibular tests (caloric test, rotatory test, assessment of visually guided eye movements). The study of eye movements was conducted with the support of the Ulmer video-oculographical system. The aim of the research was to analyse, both from a qualitative and a quantitative perspective, the vestibular and clinical findings. Particular emphasis was laid on the incidence of the "up-beating" nystagmus in different categories of patients, all supported by a statistical study. As a result, an etiopathogenetical hypothesis of the nystagmus was advanced, based on altered otolithic and cervical inputs. At the same time, the importance of the video-nystagmographical system was stressed, to the extent that it leads to a standardised and objective analysis, fundamental for clinical and forensic aspects.

  14. Gaze-Stabilizing Central Vestibular Neurons Project Asymmetrically to Extraocular Motoneuron Pools.

    Science.gov (United States)

    Schoppik, David; Bianco, Isaac H; Prober, David A; Douglass, Adam D; Robson, Drew N; Li, Jennifer M B; Greenwood, Joel S F; Soucy, Edward; Engert, Florian; Schier, Alexander F

    2017-11-22

    Within reflex circuits, specific anatomical projections allow central neurons to relay sensations to effectors that generate movements. A major challenge is to relate anatomical features of central neural populations, such as asymmetric connectivity, to the computations the populations perform. To address this problem, we mapped the anatomy, modeled the function, and discovered a new behavioral role for a genetically defined population of central vestibular neurons in rhombomeres 5-7 of larval zebrafish. First, we found that neurons within this central population project preferentially to motoneurons that move the eyes downward. Concordantly, when the entire population of asymmetrically projecting neurons was stimulated collectively, only downward eye rotations were observed, demonstrating a functional correlate of the anatomical bias. When these neurons are ablated, fish failed to rotate their eyes following either nose-up or nose-down body tilts. This asymmetrically projecting central population thus participates in both upward and downward gaze stabilization. In addition to projecting to motoneurons, central vestibular neurons also r