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Sample records for vestibular loss uvl

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

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    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

  2. Unilateral vestibular loss impairs external space representation.

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    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.

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

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    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.

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

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    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

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

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    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

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

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    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.

  7. Saccadic entropy of head impulses in acute unilateral vestibular loss.

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

    2017-10-01

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

  8. A Xenograft Model of Vestibular Schwannoma and Hearing Loss.

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    Dinh, Christine T; Bracho, Olena; Mei, Christine; Bas, Esperanza; Fernandez-Valle, Cristina; Telischi, Fred; Liu, Xue-Zhong

    2018-03-19

    Microsurgical implantation of mouse merlin-deficient Schwann cells (MD-SC) into the cerebellopontine angle of immunodeficient rats will initiate tumor formation, hearing loss, and vestibular dysfunction. The progress in identifying effective drug therapies for treatment of Neurofibromatosis type II (NF2) is limited by the availability of animal models of VS that develop hearing loss and imbalance. A microsurgical technique for implanting MD-SCs onto the cochleovestibular nerve of rats was developed. Ten Rowett Nude rats were implanted with either ∼10 MD-SCs expressing luciferase (N = 5) or vehicle (N = 5). Rats received bioluminescence imaging, auditory brainstem response testing, and were observed for head tilt every 2 weeks after surgery, for a total of 6 weeks. Tumors were harvested and processed with hematoxylin & eosin staining and immunohistochemistry was performed for S100. Rats implanted with MD-SCs developed significantly higher tumor bioluminescence measurements and hearing threshold shifts at multiple frequencies by the 4th and 6th weeks post-implantation, compared with control rats. Rats implanted with MD-SCs also developed gross tumor. The tumor volume was significantly greater than nerve volumes obtained from rats in the control group. All rats with tumors developed a head tilt, while control rats had no signs of vestibular dysfunction. Tumors demonstrated histological features of schwannoma and express S100. Using this microsurgical technique, this xenograft rat model of VS develops tumors involving the cochleovestibular nerve, shifts in hearing thresholds, and vestibular dysfunction. This animal model can be used to investigate tumor-mediated hearing loss and perform preclinical drug studies for NF2.

  9. 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.

  10. Fractionated Stereotactic Radiotherapy of Vestibular Schwannomas Accelerates Hearing Loss

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    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.

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

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    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

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

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    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).

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

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    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

  14. 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.

  15. UV-LED Curing Efficiency of Wood Coatings

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    Véronic Landry

    2015-12-01

    Full Text Available Ultraviolet light emitting diodes (UV-LEDs have attracted great interest in recent years. They can be used to polymerize coatings, such as those used for prefinished wood flooring. In this project, two lamps were compared for their suitability to be used on a wood flooring finishing line: a UV-microwave and a UV-LED lamp. Low heat emission was found for the UV-LED lamp compared to the UV-microwave one. This study also reveals that the 4 W/cm2 UV-LED lamp used is not powerful enough to cure UV high solids acrylate coatings while satisfactory results can be obtained for UV water-based formulations. In fact, conversion percentages were found to be low for the high solids coatings, leaving the coatings tacky. Higher conversion percentages were obtained for the UV water-based formulations. As a result, mass loss, hardness, and scratch resistance found for the samples cured by UV-LED were closed to the ones found for the samples cured using the UV microwave lamp.

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

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

    2015-07-13

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

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

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    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

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

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    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.

  19. 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.

  20. Evaluation of the Vestibular System and Etiology in Children with Unilateral Sensorineural Hearing Loss.

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    Birdane, Leman; İncesulu, Armağan; Özüdoğru, Erkan; Cingi, Cemal; Caklı, Hamdi; Gürbüz, Melek Kezban; Adapınar, Baki

    2016-08-01

    The aim of this study was to evaluate the vestibular system of children with unilateral sensorineural hearing loss (USNHL), investigate the etiological factors of USNHL and analyze whether a genetic predisposition exists. Thirty-three children aged less than 18 years with USNHL, who visited the ear, nose, and throat (ENT) department between January 2004 and December 2012, were included in this study. Cases with conductive hearing loss were excluded from the study. The patients were subjected to etiologic, genetic, and ophthalmologic evaluation; radiologic imaging; electronystagmography (ENG); and vestibular evoked myogenic potential (VEMP) tests. The control group, which included 25 healthy children (13 males and 12 females), had undergone audiological assessment and were subjected to ENG and VEMP tests. All of the patients had severe-to-profound hearing loss. Mumps immunoglobulin G was positive in 22 (66.7%) of 33 patients. The 35delG mutation was not found in any of the patients. All of the patients underwent temporal computed tomography (CT) and magnetic resonance imaging (MRI). Inner ear anomaly was present in 51.5% of the patients. Overall, 21 of 31 ENG patients had canal paresis in the affected ear. The VEMP response was absent on the affected side in three patients. The n23 latency average of the patient group was longer than that of the control group. Because USNHL causes irreversible problems in children, early diagnosis and auditory rehabilitation are very important. As USNHL is accompanied by inner ear anomaly, children with USNHL should undergo temporal bone CT and MRI. To evaluate the vestibular system, ENG and VEMP are non-invasive and diagnostic tests.

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

    Science.gov (United States)

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

    2015-12-15

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

  2. [Bilateral vestibular loss as a post-infection complication of yersiniosis?].

    Science.gov (United States)

    Bücheler, M; Löwenheim, H

    1997-08-01

    Yersinia infections other than plaque are caused by Yersinia pseudotuberculosis and Yersinia enterocolitica. Food and water contamination as well as animal-to-person and person-to-person contact are common pathways of transmission. Clinical manifestations include enteritis, enterocolitis, acute appendicitis, inflammation of the terminal ileum, and mesenteric adenitis. Y. enterocolitica may cause bacteremia with subsequent septicemia predominantly in patients with underlying illnesses such as diabetes mellitus or malignancy. More frequently enteritis is followed by immunological post-infectious syndromes such as arthritis and erythema nodosum. The present case report discusses bilateral vestibular loss possibly caused by an infection with Y. enterocolitica. A 27-year-old caucasian woman initially presented with the otologic symptom of spinning vertigo accompanied by nausea and vomiting. Physical exam revealed spontaneous nystagmus to the left. Bithermal caloric responses were absent. Pure tone audiometry showed a bilateral symmetric high-frequency sensorineural hearing loss. Neurologic exams did not reveal involvement of the central vestibular system. Perilymphatic fistula on the left side was excluded by tympanoscopy. Serology for rheumatoid factors and HLA B27 was negative. Lead or mercury intoxication was also excluded. In her medical history the patient reported intermittent watery diarrhea and stress dependent arthralgia that had commenced during a stay in Argentina three years ago. Serology was positive, revealing elevated titers for Y. enterocolitica type 3 (1:200) and type 9 (1:400). Bilateral vestibular loss is rare. The main cause is aminoglycoside ototoxicity or meningitis. Yersina infections have not yet been described as inducing disease of the labyrinth. Present pathophysiologic knowledge of yersinia infections is described as follows: After peroral infection, gastrointestinal permeability is increased. Low-molecular-weight substances may enter the

  3. 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

  4. Gaze stabilization in chronic vestibular-loss and in cerebellar ataxia: interactions of feedforward and sensory feedback mechanisms.

    Science.gov (United States)

    Sağlam, M; Lehnen, N

    2014-01-01

    During gaze shifts, humans can use visual, vestibular, and proprioceptive feedback, as well as feedforward mechanisms, for stabilization against active and passive head movements. The contributions of feedforward and sensory feedback control, and the role of the cerebellum, are still under debate. To quantify these contributions, we increased the head moment of inertia in three groups (ten healthy, five chronic vestibular-loss and nine cerebellar-ataxia patients) while they performed large gaze shifts to flashed targets in darkness. This induces undesired head oscillations. Consequently, both active (desired) and passive (undesired) head movements had to be compensated for to stabilize gaze. All groups compensated for active and passive head movements, vestibular-loss patients less than the other groups (P feedforward mechanisms substantially contribute to gaze stabilization. Proprioception alone is not sufficient (gain 0.2). Stabilization against active and passive head movements was not impaired in our cerebellar ataxia patients.

  5. A common SLC26A4-linked haplotype underlying non-syndromic hearing loss with enlargement of the vestibular aqueduct

    DEFF Research Database (Denmark)

    Chattaraj, Parna; Munjal, Tina; Honda, Keiji

    2017-01-01

    BACKGROUND: Enlargement of the vestibular aqueduct (EVA) is the most common radiological abnormality in children with sensorineural hearing loss. Mutations in coding regions and splice sites of the SLC26A4 gene are often detected in Caucasians with EVA. Approximately one-fourth of patients with E...

  6. [From gene to disease; genetic causes of hearing loss and visual impairment sometimes accompanied by vestibular problems (Usher syndrome)

    NARCIS (Netherlands)

    Pennings, R.J.E.; Kremer, J.M.J.; Deutman, A.F.; Kimberling, W.J.; Cremers, C.W.R.J.

    2002-01-01

    Usher syndrome is an autosomal recessively inherited disease, characterised by sensorineural hearing loss, tapetoretinal degeneration and in some cases vestibular problems. Based on the clinical heterogeneity, the disease can be classified into three clinical types (I, II and III), which have their

  7. 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

  8. Annual rate of hearing loss falls after fractionated stereotactic irradiation for vestibular schwannoma

    International Nuclear Information System (INIS)

    Sakamoto, Touru; Shirato, Hiroki; Takeichi, Norihito; Aoyama, Hidefumi; Fukuda, Satoshi; Miyasaka, Kazuo

    2001-01-01

    Purpose: The rate of hearing loss in a population before and after irradiation was investigated to determine the effect of irradiation on hearing impairment. Methods and materials: In 72 patients with vestibular schwannoma who received fractionated stereotactic irradiation from 1992 to 1999, 21 had had their hearing levels examined 3 months or more before the treatment. The mean time between the initial examination and treatment was 18.6 months (range: 3-89 months), and the mean time between treatment and the last follow-up was 24.2 months (12-69 months). Thirty-six to 50 Gy in 20-25 fractions over 5 to 6 weeks was given using an X-ray beam from a linear accelerator. Pure tone average (PTA) was measured using the mean hearing level at five frequencies, and the annual rate of hearing loss was defined as [(hearing loss in PTA(dB))/(follow-up period (months)x12)]. Results: The actual cumulative curve of decrease in tumor size of 2 mm or more was 38.3% at 2 years and 80.0% at 3 years. The mean of hearing loss in PTA was 11.6±10.3 dB (-1 to 35 dB) from the initial examination to the start of irradiation and 11.9±14.4 dB (-14 to 37 dB) from the start of irradiation to the last follow-up. The mean annual rates of hearing loss before irradiation and in the 1st, 2nd, 3rd and 4th years after irradiation were, respectively, 18.6, 11.2, 6.2, 5.1, and 5.0 dB/year. The annual rates of hearing loss in the 2nd year (P=0.025) and 3rd year (P=0.018) were significantly slower than the rate before irradiation. Conclusions: The mean annual rate of hearing loss was higher before irradiation than after irradiation, and hearing loss slowed rather than accelerated after irradiation. Although hearing loss after the treatment was usually permanent, fractionated stereotactic irradiation was suggested to be effective to lower the rate of hearing loss

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

    Science.gov (United States)

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

    2013-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Parvane Mahdi

    2013-06-01

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

  11. UV-LED Curing Efficiency of Wood Coatings

    OpenAIRE

    Véronic Landry; Pierre Blanchet; Gabrielle Boivin; Jean-François Bouffard; Mirela Vlad

    2015-01-01

    Ultraviolet light emitting diodes (UV-LEDs) have attracted great interest in recent years. They can be used to polymerize coatings, such as those used for prefinished wood flooring. In this project, two lamps were compared for their suitability to be used on a wood flooring finishing line: a UV-microwave and a UV-LED lamp. Low heat emission was found for the UV-LED lamp compared to the UV-microwave one. This study also reveals that the 4 W/cm2 UV-LED lamp used is not powerf...

  12. 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.

  13. 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.

  14. 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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. 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

    Directory of Open Access Journals (Sweden)

    Dara Meldrum

    2012-03-01

    Full Text Available Abstract Background Unilateral peripheral vestibular loss results in gait and balance impairment, dizziness and oscillopsia. Vestibular rehabilitation benefits patients but optimal treatment remains unkown. 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. Methods/Design 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. Discussion 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. Trial registration Clinical trials.gov identifier: NCT01442623

  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. 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. [From gene to disease; genetic causes of hearing loss and visual impairment sometimes accompanied by vestibular problems (Usher syndrome)].

    Science.gov (United States)

    Pennings, R J E; Kremer, H; Deutman, A F; Kimberling, W J; Cremers, C W R J

    2002-12-07

    Usher syndrome is an autosomal recessively inherited disease, characterised by sensorineural hearing loss, tapetoretinal degeneration and in some cases vestibular problems. Based on the clinical heterogeneity, the disease can be classified into three clinical types (I, II and III), which have their own genetic subtypes (Usher 1A-Usher IG, Usher 2A-Usher 2C and Usher 3). The majority of the Usher type I cases are caused by mutations in the MYO7A gene (Usher 1B) while mutations in the USH2A gene (Usher 2A) are the cause of most cases of type II. Usher syndrome type III, caused by mutations in the USH3 gene, is frequently seen only in Finland.

  1. UV-LEDs Efficiently Inactivate DNA and RNA Coliphages

    Directory of Open Access Journals (Sweden)

    Alyaa M. Zyara

    2017-01-01

    Full Text Available UV-LEDs are a new method of disinfecting drinking water. Some viruses are very resistant to UV and the efficiency of UV-LEDs to disinfect them needs to be studied. Drinking water was disinfected with UV-LEDs after spiking the water with MS2 and four UV- and/or Cl-resistant coliphages belonging to RNA or DNA coliphages isolated from municipal wastewater. UV-LEDs operating at a wavelength of 270 nm for 2 min with 120 mW of irradiation caused 0.93–2.73 Log10-reductions of coliphages tested in a reactor of a 5.2 L volume. Irradiation time of 10 min in the same system increased the Log10-reductions to 4.30–5.16. Traditional mercury UV (Hg-UV lamp at a 254 nm wavelength caused 0.67–4.08 Log10-reductions in 2 min and 4.56–7.21 Log10-reductions in 10 min in 10 mL of water. All coliphages tested except MS2 achieved 4 Log10-reductions with UV-LEDs at a dose that corresponded to 70 mWs/cm2 using Hg-UV. Thus, UV-LEDs are a promising method of disinfecting UV- and/or Cl-resistant viruses.

  2. Partial Aminoglycoside Lesions in Vestibular Epithelia Reveal Broad Sensory Dysfunction Associated with Modest Hair Cell Loss and Afferent Calyx Retraction.

    Science.gov (United States)

    Sultemeier, David R; Hoffman, Larry F

    2017-01-01

    Although the effects of aminoglycoside antibiotics on hair cells have been investigated for decades, their influences on the dendrites of primary afferent neurons have not been widely studied. This is undoubtedly due to the difficulty in disassociating pathology to dendritic processes from that resulting from loss of the presynaptic hair cell. This was overcome in the present investigation through development of a preparation using Chinchilla laniger that enabled direct perilymphatic infusion. Through this strategy we unmasked gentamicin's potential effects on afferent calyces. The pathophysiology of the vestibular neuroepithelia after post-administration durations of 0.5 through 6 months was assessed using single-neuron electrophysiology, immunohistochemistry, and confocal microscopy. Hair cell densities within cristae central zones (0.5-, 1-, 2-, and 6-months) and utricle peri- and extrastriola (6-months) regions were determined, and damage to calretinin-immunoreactive calyces was quantified. Gentamicin-induced hair cell loss exhibited a profile that reflected elimination of a most-sensitive group by 0.5-months post-administration (18.2%), followed by loss of a second group (20.6%) over the subsequent 5.5 months. The total hair cell loss with this gentamicin dose (approximately 38.8%) was less than the estimated fraction of type I hair cells in the chinchilla's crista central zone (approximately 60%), indicating that viable type I hair cells remained. Extensive lesions to afferent calyces were observed at 0.5-months, though stimulus-evoked modulation was intact at this post-administration time. Widespread compromise to calyx morphology and severe attenuation of stimulus-evoked afferent discharge modulation was found at 1 month post-administration, a condition that persisted in preparations examined through the 6-month post-administration interval. Spontaneous discharge was robust at all post-administration intervals. All calretinin-positive calyces had retracted

  3. Hearing loss associated with enlarged vestibular aqueduct and zero or one mutant allele of SLC26A4.

    Science.gov (United States)

    Rose, Jane; Muskett, Julie A; King, Kelly A; Zalewski, Christopher K; Chattaraj, Parna; Butman, John A; Kenna, Margaret A; Chien, Wade W; Brewer, Carmen C; Griffith, Andrew J

    2017-07-01

    To characterize the severity and natural history of hearing loss, and the prevalence of having a cochlear implant in a maturing cohort of individuals with enlarged vestibular aqueduct (EVA) and zero or one mutant allele of SLC26A4. Prospective cohort study of subjects ascertained between 1998 and 2015 at the National Institutes of Health Clinical Center. Study subjects were 127 individuals (median age, 8 years; range, 0-59 years) with EVA in at least one ear. Ears with EVA and zero or one mutant allele of SLC26A4 had mean 0.5/1/2/4-kHz pure-tone averages of 62.6 and 52.9 dB HL, respectively, in contrast to EVA ears with two mutant alleles of SLC26A4 (88.1 dB HL; P zero, one, and two mutant alleles, respectively (P = .00833). This association was not independent (P = .534) but reflected underlying correlations with age at time of first audiogram (P = .003) or severity of hearing loss (P = .000). Ears with EVA and zero or one mutant allele of SLC26A4 have less severe hearing loss, no difference in prevalence of fluctuation, and a lower prevalence of cochlear implantation in comparison to ears with two mutant alleles of SLC26A4. NA Laryngoscope, 127:E238-E243, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  4. Microbial UV fluence-response assessment using a novel UV-LED collimated beam system.

    Science.gov (United States)

    Bowker, Colleen; Sain, Amanda; Shatalov, Max; Ducoste, Joel

    2011-02-01

    A research study has been performed to determine the ultraviolet (UV) fluence-response of several target non-pathogenic microorganisms to UV light emitting diodes (UV-LEDs) by performing collimated beam tests. UV-LEDs do not contain toxic mercury, offer design flexibility due to their small size, and have a longer operational life than mercury lamps. Comsol Multiphysics was utilized to create an optimal UV-LED collimated beam design based on number and spacing of UV-LEDs and distance of the sample from the light source while minimizing the overall cost. The optimized UV-LED collimated beam apparatus and a low-pressure mercury lamp collimated beam apparatus were used to determine the UV fluence-response of three surrogate microorganisms (Escherichia coli, MS-2, T7) to 255 nm UV-LEDs, 275 nm UV-LEDs, and 254 nm low-pressure mercury lamps. Irradiation by low-pressure mercury lamps produced greater E. coli and MS-2 inactivation than 255 nm and 275 nm UV-LEDs and similar T7 inactivation to irradiation by 275 nm UV-LEDs. The 275 nm UV-LEDs produced more efficient T7 and E. coli inactivation than 255 nm UV-LEDs while both 255 nm and 275 nm UV-LEDs produced comparable microbial inactivation for MS-2. Differences may have been caused by a departure from the time-dose reciprocity law due to microbial repair mechanisms. Copyright © 2010 Elsevier Ltd. All rights reserved.

  5. Common Vestibular Disorders

    Directory of Open Access Journals (Sweden)

    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

  6. Vestibular evoked myogenic potential testing for the diagnosis of conductive hearing loss: survey of pediatric otolaryngologists' knowledge and beliefs.

    Science.gov (United States)

    Dargie, Jenna M; Zhou, Guangwei; Dornan, Briana K; Whittemore, Kenneth R

    2014-11-01

    To assess physicians' knowledge and beliefs regarding vestibular evoked myogenic potential (VEMP) testing in children. A survey was delivered via email in html format to 1069 members of the American Academy of Otolaryngology--Head and Neck Surgery who identified as pediatric otolaryngologists. Study data were collected and managed using the Research Electronic Data Capture (REDCap) tools. 443 (41.4%) physicians opened the email. 190 (42.9% of opens) initiated the survey, of which 117 (61.9%) fully completed the survey of the physicians who responded to a question regarding knowledge of VEMP, 16% of respondents had never heard of the test. 16% of participants would use it in the setting of diagnosing pediatric conductive hearing loss. Responses regarding the youngest age at which VEMP is possible ranged from younger than 6 months through greater than 13 years of age. Beliefs regarding utility and reliability of VEMP varied, with 'unsure' as the most frequent response. Additionally, only 26% of pediatric otolaryngologists indicated some access to the test. The knowledge and availability of VEMP testing in the pediatric otolaryngology community varies widely. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  7. Cost-effectiveness analysis of a non-contrast screening MRI protocol for vestibular schwannoma in patients with asymmetric sensorineural hearing loss

    International Nuclear Information System (INIS)

    Crowson, Matthew G.; Rocke, Daniel J.; Kaylie, David M.; Hoang, Jenny K.; Weissman, Jane L.

    2017-01-01

    We aimed to determine if a non-contrast screening MRI is cost-effective compared to a full MRI protocol with contrast for the evaluation of vestibular schwannomas. A decision tree was constructed to evaluate full MRI and screening MRI strategies for patients with asymmetric sensorineural hearing loss. If a patient were to have a positive screening MRI, s/he received a full MRI. Vestibular schwannoma prevalence, MRI specificity and sensitivity, and gadolinium anaphylaxis incidence were obtained through literature review. Institutional charge data were obtained using representative patient cohorts. One-way and probabilistic sensitivity analyses were completed to determine CE model threshold points for MRI performance characteristics and charges. The mean charge for a full MRI with contrast was significantly higher than a screening MRI ($4089 ± 1086 versus $2872 ± 741; p < 0.05). The screening MRI protocol was more cost-effective than a full MRI protocol with a willingness-to-pay from $0 to 20,000 USD. Sensitivity analyses determined that the screening protocol dominated when the screening MRI charge was less than $4678, and the imaging specificity exceeded 78.2%. The screening MRI protocol also dominated when vestibular schwannoma prevalence was varied between 0 and 1000 in 10,000 people. A screening MRI protocol is more cost-effective than a full MRI with contrast in the diagnostic evaluation of a vestibular schwannoma. A screening MRI likely also confers benefits of shorter exam time and no contrast use. Further investigation is needed to confirm the relative performance of screening protocols for vestibular schwannomas. (orig.)

  8. Cost-effectiveness analysis of a non-contrast screening MRI protocol for vestibular schwannoma in patients with asymmetric sensorineural hearing loss

    Energy Technology Data Exchange (ETDEWEB)

    Crowson, Matthew G.; Rocke, Daniel J.; Kaylie, David M. [Duke University Medical Center, Division of Otolaryngology-Head and Neck Surgery, Durham, NC (United States); Hoang, Jenny K. [Duke University Medical Center, Department of Radiology, Durham, NC (United States); Weissman, Jane L. [Oregon Health Sciences University, Professor Emerita of Diagnostic Radiology, Portland, OR (United States)

    2017-08-15

    We aimed to determine if a non-contrast screening MRI is cost-effective compared to a full MRI protocol with contrast for the evaluation of vestibular schwannomas. A decision tree was constructed to evaluate full MRI and screening MRI strategies for patients with asymmetric sensorineural hearing loss. If a patient were to have a positive screening MRI, s/he received a full MRI. Vestibular schwannoma prevalence, MRI specificity and sensitivity, and gadolinium anaphylaxis incidence were obtained through literature review. Institutional charge data were obtained using representative patient cohorts. One-way and probabilistic sensitivity analyses were completed to determine CE model threshold points for MRI performance characteristics and charges. The mean charge for a full MRI with contrast was significantly higher than a screening MRI ($4089 ± 1086 versus $2872 ± 741; p < 0.05). The screening MRI protocol was more cost-effective than a full MRI protocol with a willingness-to-pay from $0 to 20,000 USD. Sensitivity analyses determined that the screening protocol dominated when the screening MRI charge was less than $4678, and the imaging specificity exceeded 78.2%. The screening MRI protocol also dominated when vestibular schwannoma prevalence was varied between 0 and 1000 in 10,000 people. A screening MRI protocol is more cost-effective than a full MRI with contrast in the diagnostic evaluation of a vestibular schwannoma. A screening MRI likely also confers benefits of shorter exam time and no contrast use. Further investigation is needed to confirm the relative performance of screening protocols for vestibular schwannomas. (orig.)

  9. 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.

  10. Development of a method for the characterization and operation of UV-LED for water treatment.

    Science.gov (United States)

    Kheyrandish, Ataollah; Mohseni, Madjid; Taghipour, Fariborz

    2017-10-01

    Tremendous improvements in semiconductor technology have made ultraviolet light-emitting diodes (UV-LEDs) a viable alternative to conventional UV sources for water treatment. A robust and validated experimental protocol for studying the kinetics of microorganism inactivation is key to the further development of UV-LEDs for water treatment. This study proposes a protocol to operate UV-LEDs and control their output as a polychromatic radiation source. In order to systematically develop this protocol, the results of spectral power distribution, radiation profile, and radiant power measurements of a variety of UV-LEDs are presented. A wide range of UV-LEDs was selected for this study, covering various UVA, UVB, and UVC wavelengths, viewing angles from 3.5° to 135°, and a variety of output powers. The effects of operational conditions and measurement techniques were investigated on these UV-LEDs using a specially designed and fabricated setup. Operating conditions, such as the UV-LED electrical current and solder temperature, were found to significantly affect the power and peak wavelength output. The measurement techniques and equipment, including the detector size, detector distance from the UV-LED, and potential reflection from the environment, were shown to influence the results for many of the UV-LEDs. The results obtained from these studies were analyzed and applied to the development of a protocol for UV-LED characterization. This protocol is presented as a guideline that allows the operation and control of UV-LEDs in any structure, as well as accurately measuring the UV-LED output. Such information is essential for performing a reliable UV-LED assessment for the inactivation of microorganisms and for obtaining precise kinetic data. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Investigation of UV-LED Initiated Photopolymerisation of Bio-compatible HEMA

    OpenAIRE

    McDermott, Sharon

    2008-01-01

    Ultraviolet (UV) fluorescent lamps are widely used in photopolymerisation processes. However, there a number of disadvantages to these lamps, namely, their intensity varies over time and has to be constantly monitored. This thesis is concerned with the possibility of replacing these lamps with UV Light Emitting Diodes (UV-LEDs). A number of emission characteristics of both the fluorescent lamp and the UV-LEDs were measured and compared to ensure that the optical properties of the UV-LEDs were...

  12. Progressive irreversible hearing loss is caused by stria vascularis degeneration in an Slc26a4-insufficient mouse model of large vestibular aqueduct syndrome.

    Science.gov (United States)

    Ito, T; Nishio, A; Wangemann, P; Griffith, A J

    2015-12-03

    Hearing loss of patients with enlargement of the vestibular aqueduct (EVA) can fluctuate or progress, with overall downward progression. The most common detectable cause of EVA is mutations of SLC26A4. We previously described a transgenic Slc26a4-insufficient mouse model of EVA in which Slc26a4 expression is controlled by doxycycline administration. Mice that received doxycycline from conception until embryonic day 17.5 (DE17.5; doxycycline discontinued at embryonic day 17.5) had fluctuating hearing loss between 1 and 6 months of age with an overall downward progression after 6 months of age. In this study, we characterized the cochlear functional and structural changes underlying irreversible hearing loss in DE17.5 mice at 12 months of age. The endocochlear potential was decreased and inversely correlated with auditory brainstem response thresholds. The stria vascularis was thickened and edematous in ears with less severe hearing loss, and thinned and atrophic in ears with more severe hearing loss. There were pathologic changes in marginal cell morphology and gene expression that were not observed at 3 months. We conclude that strial dysfunction and degeneration are the primary causes of irreversible progressive hearing loss in our Slc26a4-insufficient mouse model of EVA. This model of primary strial atrophy may be used to explore the mechanisms of progressive hearing loss due to strial dysfunction. Published by Elsevier Ltd.

  13. Protocol for Determining Ultraviolet Light Emitting Diode (UV-LED) Fluence for Microbial Inactivation Studies.

    Science.gov (United States)

    Kheyrandish, Ataollah; Mohseni, Madjid; Taghipour, Fariborz

    2018-06-15

    Determining fluence is essential to derive the inactivation kinetics of microorganisms and to design ultraviolet (UV) reactors for water disinfection. UV light emitting diodes (UV-LEDs) are emerging UV sources with various advantages compared to conventional UV lamps. Unlike conventional mercury lamps, no standard method is available to determine the average fluence of the UV-LEDs, and conventional methods used to determine the fluence for UV mercury lamps are not applicable to UV-LEDs due to the relatively low power output, polychromatic wavelength, and specific radiation profile of UV-LEDs. In this study, a method was developed to determine the average fluence inside a water suspension in a UV-LED experimental setup. In this method, the average fluence was estimated by measuring the irradiance at a few points for a collimated and uniform radiation on a Petri dish surface. New correction parameters were defined and proposed, and several of the existing parameters for determining the fluence of the UV mercury lamp apparatus were revised to measure and quantify the collimation and uniformity of the radiation. To study the effect of polychromatic output and radiation profile of the UV-LEDs, two UV-LEDs with peak wavelengths of 262 and 275 nm and different radiation profiles were selected as the representatives of typical UV-LEDs applied to microbial inactivation. The proper setup configuration for microorganism inactivation studies was also determined based on the defined correction factors.

  14. Improved performance of UV-LED by p-AlGaN with graded composition

    KAUST Repository

    Yan, Jianchang

    2010-11-02

    AlGaN-based ultraviolet light emitting diodes (UV-LEDs) on AlN/sapphire template were grown by metal organic chemical vapour deposition. The AlN template was characterized by atomic force microscopy and high resolution X-ray diffraction. Atomic force microscopy image shows that the AlN surface is very flat, while high resolution X-ray diffraction results prove the good crystalline quality of the AlN template. A novel structure UV-LED which has several p-AlGaN layers with graded composition is compared with a common structure UV-LED which has a single p-Al0.5Ga0.5N layer. The forward bias voltage at 20 mA driving current for the novel structure UV-LED is nearly 3 V higher than that of the common structure UV-LED, however, the electroluminescence intensity of the former is over two times higher than that of the latter. The total quantum efficiency of the novel structure UV-LED is more than 50% higher than that of the common structure UV-LED. The improvement is considered to be the result of better holes injection efficiency in the novel structure UV-LED. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Atypical Manifestation of Vestibular Schwannoma

    Directory of Open Access Journals (Sweden)

    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.

  16. Fluorescence image excited by a scanning UV-LED light

    Science.gov (United States)

    Tsai, Hsin-Yi; Chen, Yi-Ju; Huang, Kuo-Cheng

    2013-03-01

    An optical scanning system using UV-LED light to induced fluorescence technology can enhance a fluorescence image significantly in a short period. It has several advantages such as lower power consumption, no scattering effect in skins, and multilayer images can be obtained to analyze skin disease. From the experiment results, the light intensity increases with increase spot size and decrease scanning speed, but the image resolution is oppositely. Moreover, the system could be widely used in clinical diagnosis and photodynamic therapy for skin disease because even the irradiated time of fluorescence substance is short but it will provide accurately positioning of fluorescence object.

  17. 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.

  18. 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

  19. 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

  20. Inactivation kinetics and efficiencies of UV-LEDs against Pseudomonas aeruginosa, Legionella pneumophila, and surrogate microorganisms.

    Science.gov (United States)

    Rattanakul, Surapong; Oguma, Kumiko

    2018-03-01

    To demonstrate the effectiveness of UV light-emitting diodes (UV-LEDs) to disinfect water, UV-LEDs at peak emission wavelengths of 265, 280, and 300 nm were adopted to inactivate pathogenic species, including Pseudomonas aeruginosa and Legionella pneumophila, and surrogate species, including Escherichia coli, Bacillus subtilis spores, and bacteriophage Qβ in water, compared to conventional low-pressure UV lamp emitting at 254 nm. The inactivation profiles of each species showed either a linear or sigmoidal survival curve, which both fit well with the Geeraerd's model. Based on the inactivation rate constant, the 265-nm UV-LED showed most effective fluence, except for with E. coli which showed similar inactivation rates at 265 and 254 nm. Electrical energy consumption required for 3-log 10 inactivation (E E,3 ) was lowest for the 280-nm UV-LED for all microbial species tested. Taken together, the findings of this study determined the inactivation profiles and kinetics of both pathogenic bacteria and surrogate species under UV-LED exposure at different wavelengths. We also demonstrated that not only inactivation rate constants, but also energy efficiency should be considered when selecting an emission wavelength for UV-LEDs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Personality Changes in Patients with Vestibular Dysfunction

    Directory of Open Access Journals (Sweden)

    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.

  2. 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...

  3. High-power UV-LED degradation: Continuous and cycled working condition influence

    Science.gov (United States)

    Arques-Orobon, F. J.; Nuñez, N.; Vazquez, M.; Segura-Antunez, C.; González-Posadas, V.

    2015-09-01

    High-power (HP) UV-LEDs can replace UV lamps for real-time fluoro-sensing applications by allowing portable and autonomous systems. However, HP UV-LEDs are not a mature technology, and there are still open issues regarding their performance evolution over time. This paper presents a reliability study of 3 W UV-LEDs, with special focus on LED degradation for two working conditions: continuous and cycled (30 s ON and 30 s OFF). Accelerated life tests are developed to evaluate the influence of temperature and electrical working conditions in high-power LEDs degradation, being the predominant failure mechanism the degradation of the package. An analysis that includes dynamic thermal and optical HP UV-LED measurements has been performed. Static thermal and stress simulation analysis with the finite element method (FEM) identifies the causes of package degradation. Accelerated life test results prove that HP UV-LEDs working in cycled condition have a better performance than those working in continuous condition.

  4. 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 ...

  5. 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.

  6. 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.

  7. Improved performance of UV-LED by p-AlGaN with graded composition

    KAUST Repository

    Yan, Jianchang; Wang, Junxi; Cong, Peipei; Sun, Lili; Liu, Naixin; Liu, Zhe; Zhao, Chao; Li, Jinmin

    2010-01-01

    force microscopy image shows that the AlN surface is very flat, while high resolution X-ray diffraction results prove the good crystalline quality of the AlN template. A novel structure UV-LED which has several p-AlGaN layers with graded composition

  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. Development and future of ultraviolet light-emitting diodes: UV-LED will replace the UV lamp

    Science.gov (United States)

    Muramoto, Yoshihiko; Kimura, Masahiro; Nouda, Suguru

    2014-06-01

    Ultraviolet light-emitting diodes (UV-LEDs) have started replacing UV lamps. The power per LED of high-power LED products has reached 12 W (14 A), which is 100 times the values observed ten years ago. In addition, the cost of these high-power LEDs has been decreasing. In this study, we attempt to understand the technologies and potential of UV-LEDs.

  10. Development and future of ultraviolet light-emitting diodes: UV-LED will replace the UV lamp

    International Nuclear Information System (INIS)

    Muramoto, Yoshihiko; Kimura, Masahiro; Nouda, Suguru

    2014-01-01

    Ultraviolet light-emitting diodes (UV-LEDs) have started replacing UV lamps. The power per LED of high-power LED products has reached 12 W (14 A), which is 100 times the values observed ten years ago. In addition, the cost of these high-power LEDs has been decreasing. In this study, we attempt to understand the technologies and potential of UV-LEDs. (invited article)

  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. Lens of controllable optical field with thin film metallic glasses for UV-LEDs.

    Science.gov (United States)

    Pan, C T; Chen, Y C; Lin, Po-Hung; Hsieh, C C; Hsu, F T; Lin, Po-Hsun; Chang, C M; Hsu, J H; Huang, J C

    2014-06-16

    In the exposure process of photolithography, a free-form lens is designed and fabricated for UV-LED (Ultraviolet Light-Emitting Diode). Thin film metallic glasses (TFMG) are adopted as UV reflection layers to enhance the irradiance and uniformity. The Polydimethylsiloxane (PDMS) with high transmittance is used as the lens material. The 3-D fast printing is attempted to make the mold of the lens. The results show that the average irradiance can be enhanced by 6.5~6.7%, and high uniformity of 85~86% can be obtained. Exposure on commercial thick photoresist using this UV-LED system shows 3~5% dimensional deviation, lower than the 6~8% deviation for commercial mercury lamp system. This current system shows promising potential to replace the conventional mercury exposure systems.

  13. Development of Efficient UV-LED Phosphor Coatings for Energy Saving Solid State Lighting

    International Nuclear Information System (INIS)

    Uwe Happek

    2006-01-01

    The University of Georgia, in collaboration with GE Global Research, has investigated the relevant quenching mechanism of phosphor coatings used in white light devices based on UV LEDs. The final goal of the project was the design and fabrication of a high-efficacy white light UV-LED device through improved geometry and optimized phosphor coatings. At the end of the research period, which was extended to seamlessly carry over the research to a follow-up program, we have demonstrated a two-fold improvement in the conversion efficiency of a white light LED device, where the increase efficacy is due to both improved phosphor quantum efficiency and lamp geometry. Working prototypes have been displayed at DOE sponsored meetings and during the final presentation at the DOE Headquarters in Washington, DC. During the first phase of the project, a fundamental understanding of quenching processes in UV-LEDs was obtained, and the relationships that describe the performance of the phosphor as a function of photon flux, temperature, and phosphor composition were established. In the second phase of the project, these findings were then implemented to design the improved UV-LED lamp. In addition, our research provides a road map for the design of efficient white light LEDs, which will be an important asset during a follow-up project led by GE

  14. CFD modeling of a UV-LED photocatalytic odor abatement process in a continuous reactor

    International Nuclear Information System (INIS)

    Wang, Zimeng; Liu, Jing; Dai, Yuancan; Dong, Weiyang; Zhang, Shicheng; Chen, Jianmin

    2012-01-01

    Highlights: ► A CFD model is developed for a UV-LED based photocatalytic deodorization reactor. ► Radiation field model and Langmuir–Hinshelwood kinetics are integrated in the model. ► The model can predict the pollutant concentration profile and the reactor performance. ► LED distance is predicted to be a critical parameter in photocatalytic reactor design. - Abstract: This paper presents a model study of a UV light-emitting-diode (UV-LED) based photocatalytic odor abatement process. It integrated computational fluid dynamics (CFD) modeling of the gas flow in the reactor with LED-array radiation field calculation and Langmuir–Hinshelwood reaction kinetics. It was applied to simulate the photocatalytic degradation of dimethyl sulfide (DMS) in a UV-LED reactor based on experimentally determined chemical kinetic parameters. A non-linear power law relating reaction rate to irradiation intensity was adopted. The model could predict the steady state DMS concentration profiles by calculating the advection, diffusion and Langmuir–Hinshelwood reaction kinetics. By affecting the radiation intensity and uniformity, the position of the LED array relative to the catalyst appeared to be a critical parameter determining DMS removal efficiency. Too small distances might yield low quantum efficiency and consequently poor abatement performance. This study provided an example of LED-based photocatalytic process modeling and gave insights into the optimization of light source design for photocatalytic applications.

  15. Ground testing and flight demonstration of charge management of insulated test masses using UV-LED electron photoemission

    Science.gov (United States)

    Saraf, Shailendhar; Buchman, Sasha; Balakrishnan, Karthik; Lui, Chin Yang; Soulage, Michael; Faied, Dohy; Hanson, John; Ling, Kuok; Jaroux, Belgacem; Suwaidan, Badr Al; AlRashed, Abdullah; Al-Nassban, Badr; Alaqeel, Faisal; Harbi, Mohammed Al; Salamah, Badr Bin; Othman, Mohammed Bin; Qasim, Bandar Bin; Alfauwaz, Abdulrahman; Al-Majed, Mohammed; DeBra, Daniel; Byer, Robert

    2016-12-01

    The UV-LED mission demonstrates the precise control of the potential of electrically isolated test masses. Test mass charge control is essential for the operation of space accelerometers and drag-free sensors which are at the core of geodesy, aeronomy and precision navigation missions as well as gravitational wave experiments and observatories. Charge management using photoelectrons generated by the 254 nm UV line of Hg was first demonstrated on Gravity Probe B and is presently part of the LISA Pathfinder technology demonstration. The UV-LED mission and prior ground testing demonstrates that AlGaN UVLEDs operating at 255 nm are superior to Hg lamps because of their smaller size, lower power draw, higher dynamic range, and higher control authority. We show laboratory data demonstrating the effectiveness and survivability of the UV-LED devices and performance of the charge management system. We also show flight data from a small satellite experiment that was one of the payloads on KACST’s SaudiSat-4 mission that demonstrates ‘AC charge control’ (UV-LEDs and bias are AC modulated with adjustable relative phase) between a spherical test mass and its housing. The result of the mission brings the UV-LED device Technology Readiness Level (TRL) to TRL-9 and the charge management system to TRL-7. We demonstrate the ability to control the test mass potential on an 89 mm diameter spherical test mass over a 20 mm gap in a drag-free system configuration, with potential measured using an ultra-high impedance contact probe. Finally, the key electrical and optical characteristics of the UV-LEDs showed less than 7.5% change in performance after 12 months in orbit.

  16. Ground testing and flight demonstration of charge management of insulated test masses using UV-LED electron photoemission

    International Nuclear Information System (INIS)

    Saraf, Shailendhar; Buchman, Sasha; Balakrishnan, Karthik; Lui, Chin Yang; Alfauwaz, Abdulrahman; DeBra, Daniel; Soulage, Michael; Faied, Dohy; Hanson, John; Ling, Kuok; Jaroux, Belgacem; Suwaidan, Badr Al; AlRashed, Abdullah; Al-Nassban, Badr; Alaqeel, Faisal; Harbi, Mohammed Al; Salamah, Badr Bin; Othman, Mohammed Bin; Qasim, Bandar Bin; Al-Majed, Mohammed

    2016-01-01

    The UV-LED mission demonstrates the precise control of the potential of electrically isolated test masses. Test mass charge control is essential for the operation of space accelerometers and drag-free sensors which are at the core of geodesy, aeronomy and precision navigation missions as well as gravitational wave experiments and observatories. Charge management using photoelectrons generated by the 254 nm UV line of Hg was first demonstrated on Gravity Probe B and is presently part of the LISA Pathfinder technology demonstration. The UV-LED mission and prior ground testing demonstrates that AlGaN UVLEDs operating at 255 nm are superior to Hg lamps because of their smaller size, lower power draw, higher dynamic range, and higher control authority. We show laboratory data demonstrating the effectiveness and survivability of the UV-LED devices and performance of the charge management system. We also show flight data from a small satellite experiment that was one of the payloads on KACST’s SaudiSat-4 mission that demonstrates ‘AC charge control’ (UV-LEDs and bias are AC modulated with adjustable relative phase) between a spherical test mass and its housing. The result of the mission brings the UV-LED device Technology Readiness Level (TRL) to TRL-9 and the charge management system to TRL-7. We demonstrate the ability to control the test mass potential on an 89 mm diameter spherical test mass over a 20 mm gap in a drag-free system configuration, with potential measured using an ultra-high impedance contact probe. Finally, the key electrical and optical characteristics of the UV-LEDs showed less than 7.5% change in performance after 12 months in orbit. (paper)

  17. 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.

  18. 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...

  19. 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.

  20. 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.

  1. 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....

  2. 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.

  3. 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...

  4. 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.

  5. MR imaging features and clinical value of vestibular aqueduct and endolymphatic sac in patients with large vestibular aqueduct syndrome

    International Nuclear Information System (INIS)

    Fang Zheming; Lou Xin; Lan Lan; Wang Hui; Wang Qiuju; Wu Nanzhou; Zhang Xiaojing

    2012-01-01

    Objective: To investigate MR imaging features of endolymphatic sac and vestibular aqueduct in patients with large vestibular aqueduct syndrome (LVAS) and its correlation with hearing loss. Methods: MR imaging findings of LVAS were analyzed in 31 cases (62 ears) retrospectively. MR imaging features were grouped into 4 types. In the first type, the signals of endolymphatic and vestibular aqueduct were hypointense without any hyperintense area. In the second type, the signals of endolymphatic sac and vestibular were hyperintense which were confined within vestibular fissure. In the third type, the area from vestibular aqueduct backward out of the edge of the petrous bone was hyperintense, but its lower boundary was above posterior semicircular. In the fourth type the area which was hyperintense was below the posterior semicircular. To avoid errors in visual inspection, the hyperintense and hypointense area of endolymphatic and the signal intensity of vestibular aqueduct and cerebrospinal fluid (CSF) were measured. The differences of signal intensity among the vestibular endolymphatic sac between the high-signal areas and low signal areas were compared with paired t-test. The correlation of the endolymphatic sac MRI classification and degree of hearing loss was analyzed by corrected Chi-square test and Spearman correlation analysis. Result: Ten ears belonged to type Ⅰ (moderate hearing loss in 1 ear,severe in 4 ears,profound in 5 ears), 17 ears belonged to type Ⅱ (moderate hearing loss in 1 ear; severe in 5 ears,profound in 11 ears), 23 ears to type Ⅲ (moderate hearing loss in 3 ear, severe in 5 ears, profound in 15 ears) and 12 ears belonged to Ⅳ (mild hearing loss in 1 ear, moderate in 1 ear, severe 3 ear, profound in 7 ears). The boundary between hyperintense and hypointense area was clear, and the signal intensity ratios was 2.02 ± 0.06. The signal ratios of hyperintense and hypointense area to vestibular and CSF were 0.95 ±0.12, 0.49 ±0.10, 0.99 ± 0

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

    Directory of Open Access Journals (Sweden)

    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.

  7. 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.

  8. [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.

  9. Comparison of UV-LED and low pressure UV for water disinfection: Photoreactivation and dark repair of Escherichia coli.

    Science.gov (United States)

    Li, Guo-Qiang; Wang, Wen-Long; Huo, Zheng-Yang; Lu, Yun; Hu, Hong-Ying

    2017-12-01

    Studies on ultraviolet light-emitting diode (UV-LED) water disinfection have shown advantages, such as safety, flexible design, and lower starting voltages. However, information about reactivation after UV-LED disinfection is limited, which is an important issue of UV light-based technology. In this study, the photoreactivation and dark repair of Escherichia coli after UV-LEDs and low pressure (LP) UV disinfection were compared. Four UV-LED units, 265 nm, 280 nm, the combination of 265 + 280 (50%), and 265 + 280 (75%) were tested. 265 nm LEDs was more effective than 280 nm LEDs and LP UV lamps for E. coli inactivation. No synergic effect for disinfection was observed from the combination of 265 and 280 nm LEDs. 265 nm LEDs had no different reactivation performances with that of LP UV, while 280 nm LEDs could significantly repress photoreactivation and dark repair at a low irradiation intensity of 6.9 mJ/cm 2 . Furthermore, the UV-induced damage of 280 nm LEDs was less repaired which was determined by endonuclease sensitive site (ESS) assay. The impaired protein activities by 280 nm LEDs might be one of the reasons that inhibited reactivation. A new reactivation rate constant, K max , was introduced into the logistic model to simulate the reactivation data, which showed positive relationship with the maximum survival ratio and was more reasonable to interpret the results of photoreactivation and dark repair. This study revealed the distinct roles of different UV lights in disinfection and reactivation, which is helpful for the future design of UV-LED equipment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Computer numerical control (CNC) lithography: light-motion synchronized UV-LED lithography for 3D microfabrication

    International Nuclear Information System (INIS)

    Kim, Jungkwun; Allen, Mark G; Yoon, Yong-Kyu

    2016-01-01

    This paper presents a computer-numerical-controlled ultraviolet light-emitting diode (CNC UV-LED) lithography scheme for three-dimensional (3D) microfabrication. The CNC lithography scheme utilizes sequential multi-angled UV light exposures along with a synchronized switchable UV light source to create arbitrary 3D light traces, which are transferred into the photosensitive resist. The system comprises a switchable, movable UV-LED array as a light source, a motorized tilt-rotational sample holder, and a computer-control unit. System operation is such that the tilt-rotational sample holder moves in a pre-programmed routine, and the UV-LED is illuminated only at desired positions of the sample holder during the desired time period, enabling the formation of complex 3D microstructures. This facilitates easy fabrication of complex 3D structures, which otherwise would have required multiple manual exposure steps as in the previous multidirectional 3D UV lithography approach. Since it is batch processed, processing time is far less than that of the 3D printing approach at the expense of some reduction in the degree of achievable 3D structure complexity. In order to produce uniform light intensity from the arrayed LED light source, the UV-LED array stage has been kept rotating during exposure. UV-LED 3D fabrication capability was demonstrated through a plurality of complex structures such as V-shaped micropillars, micropanels, a micro-‘hi’ structure, a micro-‘cat’s claw,’ a micro-‘horn,’ a micro-‘calla lily,’ a micro-‘cowboy’s hat,’ and a micro-‘table napkin’ array. (paper)

  11. 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.

  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 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.

  14. Effection of UV-LED Illuminant on the Curation of Photolatent-amidine Mixed with Bisphenol A Epoxy Acrylate under Printing Conditions

    Directory of Open Access Journals (Sweden)

    Duan Huawei

    2016-01-01

    Full Text Available In order to make photocuring ink or coating cured by UV-LED illuminant, we synthesized (4-((hexahydropyrrolo[1,2-a]pyrimidin-1 (2H-ylmethylphenyl(phenylmethanone(PL -DBN and (4-((octahydropyrimido[1,2-a]azepin-1(2H-ylmethylphenyl(phenylmet hanone(PL -DBU as photoinitiators. Different mass fraction of the photoinitiators was mixed with bisphenol A epoxy acrylate, cured by different wavelengths and power of UV-LED illuminant,and investigated the curing effects of photoinitiators on bisphenol A epoxy acrylate. The results show that the conversion of C=C double bonds of bisphenol A epoxy acrylate will increase as the mass fraction of the photoinitiators or the power of UV-LED illuminant increase. In the same conditions, the curing effect of using 365nm UV-LED illuminant on bisphenol A epoxy acrylate is better than using 395nm UV-LED illuminant. PL-DBU has a better curing effect on the bisphenol A epoxy acrylate rather than PL-DBN. When using the 8W/cm2 of 365nm UV-LED illuminant to cure a mixture of 3% PL-DBU and 97% bisphenol A epoxy acrylate, it will be dry completely in 2 seconds, moreover, the conversion reach 79%.

  15. 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.

  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. 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.

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

    Science.gov (United States)

    Baxter, Michael; Agrawal, Yuri

    2014-02-01

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

  19. 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.

  20. 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.

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. Age-Related Change in Vestibular Ganglion Cell Populations in Individuals With Presbycusis and Normal Hearing.

    Science.gov (United States)

    Gluth, Michael B; Nelson, Erik G

    2017-04-01

    We sought to establish that the decline of vestibular ganglion cell counts uniquely correlates with spiral ganglion cell counts, cochlear hair cell counts, and hearing phenotype in individuals with presbycusis. The relationship between aging in the vestibular system and aging in the cochlea is a topic of ongoing investigation. Histopathologic age-related changes the vestibular system may mirror what is seen in the cochlea, but correlations with hearing phenotype and the impact of presbycusis are not well understood. Vestibular ganglion cells, spiral ganglion cells, and cochlear hair cells were counted in specimens from individuals with presbycusis and normal hearing. These were taken from within a large collection of processed human temporal bones. Correlations between histopathology and hearing phenotype were investigated. Vestibular ganglion cell counts were positively correlated with spiral ganglion cell counts and cochlear hair cell counts and were negatively correlated with hearing phenotype. There was no statistical evidence on linear regression to suggest that the relationship between age and cell populations differed significantly according to whether presbycusis was present or not. Superior vestibular ganglion cells were more negatively correlated with age than inferior ganglion cells. No difference in vestibular ganglion cells was noted based on sex. Vestibular ganglion cell counts progressively deteriorate with age, and this loss correlates closely with changes in the cochlea, as well as hearing phenotype. However, these correlations do not appear to be unique in individuals with presbycusis as compared with those with normal hearing.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Evidence for a role of orexin/hypocretin system in vestibular lesion-induced locomotor abnormalities in rats

    Directory of Open Access Journals (Sweden)

    Leilei Pan

    2016-07-01

    Full Text Available Vestibular damage can induce locomotor abnormalities in both animals and humans. Rodents with bilateral vestibular loss showed vestibular deficits syndrome such as circling, opisthotonus as well as locomotor and exploratory hyperactivity. Previous studies have investigated the changes in the dopamine system after vestibular loss, but the results are inconsistent and inconclusive. Numerous evidences indicate that the orexin system is implicated in central motor control. We hypothesized that orexin may be potentially involved in vestibular loss-induced motor disorders. In this study, we examined the effects of arsanilate- or 3, 3′-iminodipropionitrile (IDPN-induced vestibular lesion (AVL or IVL on the orexin-A (OXA labeling in rat hypothalamus using immunohistochemistry. The vestibular lesion-induced locomotor abnormalities were recorded and verified using a histamine H4 receptor antagonist JNJ7777120 (20 mg/kg, i.p.. The effects of the orexin receptor type 1 antagonist SB334867 (16 μg, i.c.v. on these behavior responses were also investigated. At 72 h post-AVL and IVL, animals exhibited vestibular deficit syndrome and locomotor hyperactivity in the home cages. These responses were significantly alleviated by JNJ7777120 which also eliminated AVL-induced increases in exploratory behavior in an open field. The numbers of OXA-labeled neurons in the hypothalamus were significantly increased in the AVL animals at 72 h post-AVL and in the IVL animals at 24, 48 and 72 h post-IVL. SB334867 significantly attenuated the vestibular deficit syndrome and locomotor hyperactivity at 72 h post-AVL and IVL. It also decreased exploratory behavior in the AVL animals. These results suggested that the alteration of OXA expression might contribute to locomotor abnormalities after acute vestibular lesion. The orexin receptors might be the potential therapeutic targets for vestibular disorders.

  14. 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...

  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

    Full Text Available OBJETIVO: verificar os achados vestibulares em pacientes com perda auditiva neurossenssorial usuários de aparelho de amplificação sonora individual. MÉTODOS: vinte pacientes, 11 do sexo feminino e nove do sexo masculino, com idades entre 39 e 85 anos, com perda auditiva neurossenssorial bilateral de grau moderado e severo foram atendidos em uma Instituição de Ensino Superior e submetidos a uma anamnese, inspeção otológica, avaliação audiológica, imitanciometria e ao exame vestibular por meio da vectoeletronistagmografia. RESULTADOS: a dos 20 pacientes avaliados, 18 (90% apresentaram queixa de zumbido, 15 (75% queixa de tontura e oito (40% queixa de cefaléia; b houve predomínio de alteração na prova calórica e no sistema vestibular periférico; c o resultado do exame vestibular esteve alterado em 14 pacientes (70%, sendo, oito casos (40% de síndrome vestibular periférica irritativa e seis casos (30% de síndrome vestibular periférica deficitária; d verificou-se diferença significativa entre o resultado do exame vestibular e o tempo de uso do aparelho de amplificação sonora individual; e dos cinco pacientes que não referiram nenhum sintoma vestibular, quatro (80% apresentaram alteração no exame. CONCLUSÃO: ressalta-se a sensibilidade e importância do estudo funcional do sistema do equilíbrio neste tipo de população, uma vez que podem ocorrer alterações na avaliação labiríntica independente da presença de sintomas.PURPOSE: to check vestibular findings in patients with sensoneural hearing loss, hearing aid users. METHODS: 20 patients (eleven females and nine males aging from 39 to 85-year-old with bilateral sensorineural hearing loss, from moderate to severe degrees, were attended in a higher education institution evaluated by medical history, otological inspections, complete basic conventional audiological evaluations, acoustic impedance tests and vectoeletronystagmography. RESULTS: a from the 20 evaluated

  16. 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/

  17. 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...

  18. [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.

  19. Functional Analysis in Long-Term Operation of High Power UV-LEDs in Continuous Fluoro-Sensing Systems for Hydrocarbon Pollution

    Science.gov (United States)

    Arques-Orobon, Francisco Jose; Nuñez, Neftali; Vazquez, Manuel; Gonzalez-Posadas, Vicente

    2016-01-01

    This work analyzes the long-term functionality of HP (High-power) UV-LEDs (Ultraviolet Light Emitting Diodes) as the exciting light source in non-contact, continuous 24/7 real-time fluoro-sensing pollutant identification in inland water. Fluorescence is an effective alternative in the detection and identification of hydrocarbons. The HP UV-LEDs are more advantageous than classical light sources (xenon and mercury lamps) and helps in the development of a low cost, non-contact, and compact system for continuous real-time fieldwork. This work analyzes the wavelength, output optical power, and the effects of viscosity, temperature of the water pollutants, and the functional consistency for long-term HP UV-LED working operation. To accomplish the latter, an analysis of the influence of two types 365 nm HP UV-LEDs degradation under two continuous real-system working mode conditions was done, by temperature Accelerated Life Tests (ALTs). These tests estimate the mean life under continuous working conditions of 6200 h and for cycled working conditions (30 s ON & 30 s OFF) of 66,000 h, over 7 years of 24/7 operating life of hydrocarbon pollution monitoring. In addition, the durability in the face of the internal and external parameter system variations is evaluated. PMID:26927113

  20. Monitoring of TiO2-catalytic UV-LED photo-oxidation of cyanide contained in mine wastewater and leachate.

    Science.gov (United States)

    Kim, Seong Hee; Lee, Sang Woo; Lee, Gye Min; Lee, Byung-Tae; Yun, Seong-Taek; Kim, Soon-Oh

    2016-01-01

    A photo-oxidation process using UV-LEDs and TiO2 was studied for removal of cyanide contained in mine wastewater and leachates. This study focused on monitoring of a TiO2-catalyzed LED photo-oxidation process, particularly emphasizing the effects of TiO2 form and light source on the efficiency of cyanide removal. The generation of hydroxyl radicals was also examined during the process to evaluate the mechanism of the photo-catalytic process. The apparent removal efficiency of UV-LEDs was lower than that achieved using a UV-lamp, but cyanide removal in response to irradiation as well as consumption of electrical energy was observed to be higher for UV-LEDs than for UV-lamps. The Degussa P25 TiO2 showed the highest performance of the TiO2 photo-catalysts tested. The experimental results indicate that hydroxyl radicals oxidize cyanide to OCN(-), NO2(-), NO3(-), HCO3(-), and CO3(2-), which have lower toxicity than cyanide. In addition, the overall efficacy of the process appeared to be significantly affected by diverse operational parameters, such as the mixing ratio of anatase and rutile, the type of gas injected, and the number of UV-LEDs used. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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.

  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. Current concepts and future approaches to vestibular rehabilitation.

    Science.gov (United States)

    Tjernström, Fredrik; Zur, Oz; Jahn, Klaus

    2016-04-01

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

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

    Science.gov (United States)

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

    2005-02-01

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

  5. Epitaxial growth and properties of AlGaN-based UV-LEDs on Si(111) substrates

    Energy Technology Data Exchange (ETDEWEB)

    Saengkaew, Phannee

    2010-07-08

    An increasing demand for bright and efficient ultraviolet light emitting diodes (UVLEDs) is generated by numerous applications such as biochemical sensors, purification and sterilization, and solid-state white lighting. Al{sub x}Ga{sub 1-x}N is a promising material to develop UVLEDs due to the direct wide-bandgap material for emission wavelengths in the UV range and the capability of n- and p-type doping. To develop UV-LEDs on Si substrates is very interesting for low-cost UV-light sources since the Si substrate is available at low cost, in large-diameter size enabling the integration with well-known Si electronics. This work presents the first crack-free AlGaN-based UV-LEDs on Si(111) substrates by MOVPE growth. This AlGaN-based UV-LED on Si(111) substrate consists of Al{sub 0.1}Ga{sub 0.9}N:Si layers on LT-AlN/HT-AlN SL buffer layers and an active layer of GaN/Al{sub 0.1}Ga{sub 0.9}N MQWs followed by Mg-doped (GaN/Al{sub 0.1}Ga{sub 0.9}N) superlattices and GaN:Mg cap layers. It yields a {proportional_to}350 nm UV electroluminescence at room temperature and a turn-on voltage in a range of 2.6-3.1 V by current-voltage (I-V) measurements. The novel LT-AlN/HT-AlN superlattice buffer layers efficiently improve the crystalline quality of Al{sub x}Ga{sub 1-x}N layers and compensate a thermal tensile strain in Al{sub x}Ga{sub 1-x}N layers after cooling as observed by in-situ curvature measurements. The dislocation density could be reduced from 8.4 x 10{sup 10} cm{sup -2} in the AlN-based SLs to 1.8 x 10{sup 10} cm{sup -2} in the Al{sub 0.1}Ga{sub 0.9}N layers as determined by cross-sectional transmission electron microscopy (TEM) measurements. Crack-free Al{sub x}Ga{sub 1-x}N layers grown on these LT-AlN/HT-AlN superlattices with 0.05{<=}x{<=} 0.65 are achieved on Si substrates with good crystalline, optical, and electrical properties. The best crystalline quality of Al{sub 0.1}Ga{sub 0.9}N is obtained with {omega}-FWHMs of the (0002) and (10-10) reflections of

  6. 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.

  7. 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...

  8. Extremely discrepant mutation spectrum of SLC26A4 between Chinese patients with isolated Mondini deformity and enlarged vestibular aqueduct

    OpenAIRE

    Huang, Shasha; Han, Dongyi; Yuan, Yongyi; Wang, Guojian; Kang, Dongyang; Zhang, Xin; Yan, Xiaofei; Meng, Xiaoxiao; Dong, Min; Dai, Pu

    2011-01-01

    Abstract Background Mutations in SLC26A4 cause Pendred syndrome (hearing loss with goiter) or DFNB4 (non-syndromic hearing loss with inner ear malformation, such as enlarged vestibular aqueduct or Mondini deformity). The relationship between mutations in SLC26A4 and Mondini deformity without enlarged vestibular aqueduct has not been studied in any Chinese deaf population. The purpose of this study was to assess whether mutations in the SLC26A4 gene cause Mondini deformity without an enlarged ...

  9. 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.

  10. In-situ metrology in multiwafer reactors during MOVPE of AIN-based UV-LEDs (Conference Presentation)

    Science.gov (United States)

    Knauer, Arne; Brunner, Frank; Kolbe, Tim; Hagedorn, Sylvia; Kueller, Viola; Weyers, Markus

    2017-02-01

    UV-LEDs are of great interest for applications like disinfection, gas sensing, and phototherapy. The cost sensitive LEDs are commonly grown by MOVPE on transparent AlN/sapphire templates. The large thermal and lattice mismatch between AlN and sapphire generates a very high dislocation density (DD) and causes big challenges in strain management. The threading dislocation density should be reduced to the order of low 108cm-2 for high internal efficiency of the AlGaN based UV-LED structures. The TDD will be reduced mainly by dislocation annihilation during the growth of thick Al(Ga)N layers, which is a challenge in terms of strain management. We present how in-situ reflectometry and curvature measurement (EpiCurveTT(at)LayTec) in commercial multiwafer growth reactors helps to optimize the growth processes concerning growth rates, surface roughening and avoidance of layer cracking on 2inch substrates and enhance the reproducibility of epitaxial growth. The growth of up to 3 μm thick planar AlN templates and up-to 10 μm thick AlN/sapphire templates by epitaxial lateral overgrowth of stripe patterned templates for UV-C LED structures will be highlighted. The implementation of different types of AlN/GaN superlattices for the subsequent growth of up to 5μm thick Al0.5Ga0.5N layer for UVB LED structures will be shown. Correlations to ex-situ measurements like X-ray diffraction and TEM analysis of defects in the LED structures will be shown. Some challenges of in-situ control through very narrow viewports as in Close Coupled Showerhead reactors will be discussed as well as the influence of silicon doping on curvature and dislocation density in Al(Ga)N layers.

  11. 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

  12. 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.

  13. 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...

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

    Directory of Open Access Journals (Sweden)

    Fairbanks Robert K

    2009-12-01

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

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

    Science.gov (United States)

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

    2009-12-18

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

  16. 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.

  17. [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.

  18. Immunohistochemical characterisation and localisation of cannabinoid CB1 receptor protein in the rat vestibular nucleus complex and the effects of unilateral vestibular deafferentation.

    Science.gov (United States)

    Ashton, John C; Zheng, Yiwen; Liu, Ping; Darlington, Cynthia L; Smith, Paul F

    2004-09-24

    CB1 receptor expression has been reported to be low in the brainstem compared with the forebrain, and low in the vestibular nucleus complex (VNC) compared with other regions in the brainstem. However, a frequent effect of cannabis is dizziness and loss of balance. This may be due to the activation of cannabinoid receptors in the central vestibular pathways. We used immunohistochemistry to study the distribution of CB1 receptor protein in the VNC, and Western blotting to measure CB1 receptor expression in the VNC following unilateral vestibular deafferentation (UVD); the hippocampal CA1, CA2/3 and dentate gyrus (DG) regions were also analysed for comparison. This study confirms a previous electrophysiological demonstration that CB1 receptors exist in significant densities in the VNC and are likely to contribute to the neurochemical control of the vestibular reflexes. Nonetheless, CB1 receptor expression did not change significantly in the VNC during vestibular compensation. In addition, despite some small but significant changes in CB1 receptor expression in the CA2/3 and the DG following UVD, in no case were these differences statistically significant in comparison to both control groups.

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

    Science.gov (United States)

    Kluzik, JoAnn; Hlavacka, Frantisek

    2016-01-01

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

  20. [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.

  1. 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.

  2. Audio-vestibular signs and symptoms in Chiari malformation type i. Case series and literature review.

    Science.gov (United States)

    Guerra Jiménez, Gloria; Mazón Gutiérrez, Ángel; Marco de Lucas, Enrique; Valle San Román, Natalia; Martín Laez, Rubén; Morales Angulo, Carmelo

    2015-01-01

    Chiari malformation is an alteration of the base of the skull with herniation through the foramen magnum of the brain stem and cerebellum. Although the most common presentation is occipital headache, the association of audio-vestibular symptoms is not rare. The aim of our study was to describe audio-vestibular signs and symptoms in Chiari malformation type i (CM-I). We performed a retrospective observational study of patients referred to our unit during the last 5 years. We also carried out a literature review of audio-vestibular signs and symptoms in this disease. There were 9 patients (2 males and 7 females), with an average age of 42.8 years. Five patients presented a Ménière-like syndrome; 2 cases, a recurrent vertigo with peripheral features; one patient showed a sudden hearing loss; and one case suffered a sensorineural hearing loss with early childhood onset. The most common audio-vestibular symptom indicated in the literature in patients with CM-I is unsteadiness (49%), followed by dizziness (18%), nystagmus (15%) and hearing loss (15%). Nystagmus is frequently horizontal (74%) or down-beating (18%). Other audio-vestibular signs and symptoms are tinnitus (11%), aural fullness (10%) and hyperacusis (1%). Occipital headache that increases with Valsalva manoeuvres and hand paresthesias are very suggestive symptoms. The appearance of audio-vestibular manifestations in CM-I makes it common to refer these patients to neurotologists. Unsteadiness, vertiginous syndromes and sensorineural hearing loss are frequent. Nystagmus, especially horizontal and down-beating, is not rare. It is important for neurotologists to familiarise themselves with CM-I symptoms to be able to consider it in differential diagnosis. Copyright © 2014 Elsevier España, S.L.U. y Sociedad Española de Otorrinolaringología y Patología Cérvico-Facial. All rights reserved.

  3. 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.

  4. 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.

  5. 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.

  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. 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.

  8. 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...

  9. Auditory, Vestibular and Cognitive Effects due to Repeated Blast Exposure on the Warfighter

    Science.gov (United States)

    2012-10-01

    rocket-propelled grenades (RPG) and from impacts to the head from accidents caused by enemy action, equipment failure, or other factors. The...Vestibular schwannoma o Sudden sensorineural hearing loss o Cerebrovascular disorders o Whiplash injury o Systemic disorders: e.g. chronic renal

  10. 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

  11. Characterization and optimization of an inkjet-printed smart textile UV-sensor cured with UV-LED light

    Science.gov (United States)

    Seipel, S.; Yu, J.; Periyasamy, A. P.; Viková, M.; Vik, M.; Nierstrasz, V. A.

    2017-10-01

    For the development of niche products like smart textiles and other functional high-end products, resource-saving production processes are needed. Niche products only require small batches, which makes their production with traditional textile production techniques time-consuming and costly. To achieve a profitable production, as well as to further foster innovation, flexible and integrated production techniques are a requirement. Both digital inkjet printing and UV-light curing contribute to a flexible, resource-efficient, energy-saving and therewith economic production of smart textiles. In this article, a smart textile UV-sensor is printed using a piezoelectric drop-on-demand printhead and cured with a UV-LED lamp. The UVcurable ink system is based on free radical polymerization and the integrated UVsensing material is a photochromic dye, Reversacol Ruby Red. The combination of two photoactive compounds, for which UV-light is both the curer and the activator, challenges two processes: polymer crosslinking of the resin and color performance of the photochromic dye. Differential scanning calorimetry (DSC) is used to characterize the curing efficiency of the prints. Color measurements are made to determine the influence of degree of polymer crosslinking on the developed color intensities, as well as coloration and decoloration rates of the photochromic prints. Optimized functionality of the textile UV-sensor is found using different belt speeds and lamp intensities during the curing process.

  12. Investigation of the effect of UV-LED exposure conditions on the production of vitamin D in pig skin

    DEFF Research Database (Denmark)

    Barnkob, Line Lundbæk; Argyraki, Aikaterini; Petersen, Paul Michael

    2016-01-01

    study the exposure conditions with ultraviolet (UV) LEDs were systematically investigated in the wavelength range 280-340 nm for achieving optimal vitamin D bio-fortification in pig skin. A wavelength of 296 nm was found to be optimal for vitamin D3 production. The maximum dose of 20 kJ/m2 produced 3.......5-4 µg vitamin D3/cm2 pig skin. Vitamin D3 produced was independent on the combination of time and intensity of the LED source. The increased UV exposure by UV-LEDs may be readily implemented in existing food production facilities, without major modifications to the process or processing equipment......The dietary intake of vitamin D is currently below the recommended intake of 10-20 µg vitamin D/day. Foods with increased content of vitamin D or new products with enhanced vitamin D are warranted. Light-emitting diodes (LEDs) are a potential new resource in food production lines. In the present...

  13. Presbyequilibrium in the oldest old, a combination of vestibular, oculomotor and postural deficits.

    Science.gov (United States)

    Tuunainen, Eeva; Poe, Dennis; Jäntti, Pirkko; Varpa, Kirsi; Rasku, Jyrki; Toppila, Esko; Pyykkö, Ilmari

    2011-01-01

    Dizziness, impaired balance and fear of falling are common complaints in the elderly. We evaluated the association of vestibular symptoms with vestibular findings in the elderly by posturography and video-oculography (VOG). We studied 38 oldest old subjects (≥ 85 yrs, mean age 89) living in a residential home. Vestibular symptoms were taken with a structured questionnaire, the Mini Mental State Examination (MMSE) was scored and any falls were recorded over a period of 12 months. Posturography was measured with a force platform and eye movements were measured by video-oculography. In the majority of the elderly, vestibular abnormalities were found, such as reduced vestibulo-ocular reflex gain 6/38, spontaneous nystagmus 5/38, gaze deviation nystagmus 5/38, head shaking nystagmus 9/38, pathologic head thrust test 10/38, and positional nystagmus 17/38. Posturography demonstrated two major findings: the body support area was limited and the use of vision for postural control was reduced. In principal component analysis of the vertigo, four major factors described elements of failure in the vestibular and other systems important to maintenance of balance: episodic vertigo, postural instability, multisystem failure (frail) and presyncopal imbalance. These four factors were associated in different degrees to vestibular abnormalities and falls. During the follow-up period, in 19 elderly (19/38), one or more falls were recorded. Progressive loss of balance in the aged, or "presbyequilibrium," is a complex and incompletely understood process involving vestibular, oculomotor, visual acuity, proprioception, motor, organ system and metabolic weaknesses and disorders. These factors provide a potential basis for streamlining diagnostic evaluations and aiding in planning for effective therapy. In oldest old, these problems are magnified, increasing the need for additional expertise in their care, which may be met by training specialized healthcare staff.

  14. A novel single-step surgical technique for vestibular deepening using laser in conjunction with periodontal flap surgery

    Directory of Open Access Journals (Sweden)

    Ashu Bhardwaj

    2016-01-01

    Full Text Available Moderate-to-severe chronic periodontitis results in clinical loss of attachment, reduced width of attached gingiva (AG, periodontal pockets beyond mucogingival junction (MGJ, gingival recession, loss of alveolar bone, and decreased vestibular depth (VD. The encroachment of frenal and muscle attachments on marginal gingiva increases the rate of progression of periodontal pockets, prevents healing, and causes their recurrence after therapy. Loss of VD and AG associated with continuous progression of pocket formation and bone loss requires two-stage surgical procedures. In this article, one-stage surgical procedure is being described for the first time, to treat the periodontal pockets extending beyond the MGJ by periodontal flap surgery along with vestibular deepening with diode laser to increase the AG. One-step surgical technique is illustrated whereby pocket therapy with reconstruction of lost periodontal tissues can be done along with gingival augmentation by vestibular deepening.

  15. 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

  16. 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 ...

  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

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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2016-01-01

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

  20. Audiological and vestibular features in affected subjects with USH3: a genotype/phenotype correlation.

    Science.gov (United States)

    Sadeghi, Mehdi; Cohn, Edward S; Kimberling, William J; Tranebjaerg, Lisbeth; Möller, Claes

    2005-05-01

    The aims were to compare the genotype/phenotype relationship between USH3 mutations and the consequent hearing and vestibular phenotype; and to compare hearing loss (HL) progression between Usher syndrome types IB, IIA and USH3. Genetic, audiometric and vestibular examinations were performed in 28 subjects with USH3. Five different mutations in USH3 were identified. Severe HL was present from an early age (4 to 6 years) in 35% of subjects with USH3. Progression of HL begins in the first decade, and approximately 50% of subjects with USH3 become profoundly deaf by age 40. Various vestibular abnormalities were found in about half (10/22) of the tested subjects with USH3. Depending on the severity of HL, subjects with USH3 might be misdiagnosed as either Usher type IB or IIA. The results from this study can be used as discriminatory features in differential diagnosis of this syndrome.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. Material and device studies for the development of ultra-violet light emitting diodes (UV-LEDS) along polar, non-polar and semi-polar directions

    Science.gov (United States)

    Chandrasekaran, Ramya

    Over the past few years, significant effort was dedicated to the development of ultraviolet light emitting diodes (UV-LEDs) for a variety of applications. Such applications include chemical and biological detection, water purification and solid-state lighting. III-Nitride LEDs based on multiple quantum wells (MQWs) grown along the conventional [0001] (polar) direction suffer from the quantum confined Stark effect (QCSE), due to the existence of strong electric fields that arise from spontaneous and piezoelectric polarization. Thus, there is strong motivation to develop MQW-based III-nitride LED structures grown along non-polar and semi-polar directions. The goal of this dissertation is to develop UV-LEDs along the [0001] polar and [11 2¯ 0] non-polar directions by the method of Molecular Beam Epitaxy (MBE). The polar and non-polar LEDs were grown on the C-plane and R-plane sapphire substrates respectively. This work is a combination of materials science studies related to the nucleation, growth and n- and p-type doping of III-nitride films on these two substrates, as well as device studies related to fabrication and characterization of UV-LEDs. It was observed that the crystallographic orientation of the III-nitride films grown on R-plane sapphire depends strongly on the kinetic conditions of growth of the Aluminum Nitride (AIN) buffer. Specifically, growth of the AIN buffer under group III-rich conditions leads to nitride films having the (11 2¯ 0) non polar planes parallel to the sapphire surface, while growth of the buffer under nitrogen rich conditions leads to nitride films with the (11 2¯ 6) semi-polar planes parallel to the sapphire surface. The electron concentration and mobility for the films grown along the polar, non-polar and semi-polar directions were investigated. P-type doping of Gallium Nitride (GaN) films grown on the nonpolar (11 2¯ 0) plane do not suffer from polarity inversion and thus the material was doped p-type with a hole concentration

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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....

  11. Vestibular schwannoma and fitness to fly.

    Science.gov (United States)

    Pons, Yoann; Raynal, Marc; Hunkemöller, Iris; Lepage, Pierre; Kossowski, Michel

    2010-10-01

    When a pilot is referred for vestibular schwannoma (VS), his or her fitness to fly may be questioned. The objective of this retrospective study was to describe a series of VS cases in a pilot population and to discuss their fitness to fly options. Between September 2002 and March 2010, the ENT/Head and Neck Surgery Department of the National Pilot Expertise Center conducted nearly 120,000 expert consultations for 40,000 pilots. We examined the files of 10 pilots who were referred to our 2 national experts for VS. At the time of the expert consultation, hypoacusis was present in nine cases (four with total deafness), tinnitus in one case, and vertigo in nine cases. In our series, only 2 of the 10 pilots experienced a negative impact on their fitness to fly. Decisions on fitness to fly were based on several factors: minimally disturbed audition, i.e., less than a 35-dB hearing loss with a good speech discrimination score; good balance, i.e., no reported difficulties; no spontaneous nystagmus recorded on videonystagmography (VNG); no postural deviation; and a normal head-shaking test. The delay and the VS's evolution between diagnosis and expert consultation are important because the selection of a treatment to control VS is critical in minimizing the possible associated complications. When a pilot is referred for VS, his or her fitness to fly is determined by the size of the tumor, balance, auditory status, and the follow-up results of these findings. The complications that may arise from VS treatments must also be considered.

  12. [Cavernous haemangiomas: hearing and vestibular inaugural symptoms].

    Science.gov (United States)

    Dumas, G; Schmerber, S

    2004-11-01

    Cavernous haemangiomas (cavernomas)(CH) are relatively rare (2% of cranial tumoral pathology) vascular malformations mostly observed in the central nervous system. Their most common topographical site in brain stem is midline in the pons, for which clinical course may mimic symptoms of peripheral origin (sudden deafness, fluctuating hearing loss, Meniere-like vertigo). To establish the correlation between the clinical manifestations of hearing and balance disturbance and the anatomical site within the pons of cavernous haemangiomas, and to describe their clinical features, and the findings on auditory brainstem response (ABR) and magnetic resonance imaging (MRI). To propose a literature review about CH and its implications. We made a retrospective review of the histories of three patients aged 24, 44 and 45 years, diagnosed as having cavernomas of the brainstem in which audiometric evaluation, videonystagmography (VNG), ABR and imaging techniques lead to the diagnosis of intracranial cavernoma. The clinical and radiological files were reviewed and a direct relationship between symptoms and localization was found in all 3 patients, especially in relation to our understanding of the auditory and vestibular pathways within the brainstem. The literature regarding cavernomas of the pons is reviewed and the clinical, neuroimage, pathological, natural course and management aspects of the disease are discussed. We recommend the use of cerebral MRI for initial diagnosis which shows a typical rosette-like appearance with a heterogeneous signal on T2-weighted images, along with follow-up and investigation into similar profiles among family members. At present there is no consensus about the treatment to follow when cavernomas are located in the brain stem. There is no specific medical treatment for this condition, and surgery is indicated only exceptionally. Anticoagulant therapy, platelet-dispersing medication and violent sports activities are contraindicated.

  13. 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.

  14. 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.

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

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    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.

  16. 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.

  17. 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

  18. Vestibular-Evoked Myogenic Potentials in Bilateral Vestibulopathy

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    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.

  19. 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.

  20. 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.

  1. 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.

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

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    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.

  3. 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.

  4. Vestibular migraine: clinical and epidemiological aspects

    Directory of Open Access Journals (Sweden)

    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.

  5. Interaural difference values of vestibular evoked myogenic.

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    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. 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

  8. Computed tomography findings in large vestibular aqueduct syndrome.

    Science.gov (United States)

    Ma, Xiufang; Yang, Ying; Xia, Ming; Li, Dumin; Xu, Anting

    2009-07-01

    Patients with large vestibular aqueduct syndrome (LVAS) have disturbed morphogenesis of bony labyrinth. Semicircular canal anomalies are common in LVAS. To describe the additional inner ear anomalies on CT imaging in pediatric patients with LVAS, and to investigate the lateral semicircular canal (LSCC) anomalies associated with LVAS by measurement of the LSCC bony island width. We retrospectively reviewed the digitally stored temporal bone CT imaging obtained for 23 patients with LVAS, additional inner ear anomalies were noted, and measurements of the LSCC bony island width were made on axial CT scans on the workstation. Measurements were compared to the normative data obtained from 20 patients without sensorineural hearing loss. Of the 23 patients (bilateral in 22 and unilateral in 1), additional inner ear malformations were identified in 21 cases presenting either singly or in combination. A small LSCC bony island (Mondini deformity was identified in 6 ears.

  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. Hearing, speech, language, and vestibular disorders in the fetal alcohol syndrome: a literature review.

    Science.gov (United States)

    Church, M W; Kaltenbach, J A

    1997-05-01

    Fetal alcohol syndrome (FAS) is characterized in part by mental impairment, as well as craniofacial and ocular anomalies. These conditions are traditionally associated with childhood hearing disorders, because they all have a common embryonic origin in malformations of the first and second branchial arches, and have similar critical periods of vulnerability to toxic insult. A review of human and animal research indicates that there are four types of hearing disorders associated with FAS. These are: (1) a developmental delay in auditory maturation, (2) sensorineural hearing loss, (3) intermittent conductive hearing loss due to recurrent serous otitis media, and (4) central hearing loss. The auditory and vestibular systems share the same peripheral apparatuses (the inner ear and eighth cranial nerve) and are embryologically and structurally similar. Consequently, vestibular disorders in FAS children might be expected. The evidence for vestibular dysfunction in FAS is ambiguous, however. Like other syndromes associated with craniofacial anomalies, hearing disorders, and mental impairment, FAS is also characterized by a high prevalence of speech and language pathology. Hearing disorders are a form of sensory deprivation. If present during early childhood, they can result in permanent hearing, language, and mental impairment. Early identification and intervention to treat hearing, language, and speech disorders could therefore result in improved outcome for the FAS child. Specific recommendations are made for intervention and future research.

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

    Science.gov (United States)

    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.

  12. Photocatalytic decomposition of selected estrogens and their estrogenic activity by UV-LED irradiated TiO_2 immobilized on porous titanium sheets via thermal-chemical oxidation

    International Nuclear Information System (INIS)

    Arlos, Maricor J.; Liang, Robert; Hatat-Fraile, Melisa M.; Bragg, Leslie M.; Zhou, Norman Y.; Servos, Mark R.; Andrews, Susan A.

    2016-01-01

    Highlights: • TiO_2 self-assembled on oxidized porous titanium sheets. • UV-LED/TiO_2 membrane treatment reduced the concentrations of estrogens. • Different pH conditions affect treatment efficiency. • The estrogenic activity removal was similar to the chemical disappearance. - Abstract: The removal of endocrine disrupting compounds (EDCs) remains a big challenge in water treatment. Risks associated with these compounds are not clearly defined and it is important that the water industry has additional options to increase the resiliency of water treatment systems. Titanium dioxide (TiO_2) has potential applications for the removal of EDCs from water. TiO_2 has been immobilized on supports using a variety of synthesis methods to increase its feasibility for water treatment. In this study, we immobilized TiO_2 through the thermal-chemical oxidation of porous titania sheets. The efficiency of the material to degrade target EDCs under UV-LED irradiation was examined under a wide range of pH conditions. A yeast-estrogen screen assay was used to complement chemical analysis in assessing removal efficiency. All compounds but 17β-estradiol were degraded and followed a pseudo first-order kinetics at all pH conditions tested, with pH 4 and pH 11 showing the most and the least efficient treatments respectively. In addition, the total estrogenic activity was substantially reduced even with the inefficient degradation of 17β-estradiol. Additional studies will be required to optimize different treatment conditions, UV-LED configurations, and membrane fouling mitigation measures to make this technology a more viable option for water treatment.

  13. 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

  14. 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

  15. 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.

  16. 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

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. Otological and vestibular symptoms in patients with low grade (Quebec grades one and two) whiplash injury.

    Science.gov (United States)

    Rowlands, R G; Campbell, I K; Kenyon, G S

    2009-02-01

    To establish the prevalence of new vestibular and otological symptoms in a group of patients who had sustained a low grade (Quebec grades one or two) whiplash injury. A retrospective review of the case records of 109 patients undergoing assessment by a single practitioner for the purposes of compiling a medicolegal report on their whiplash injury. Four patients complained of short-lived, non-specific dizziness symptoms in the acute phase following their original injury. There were no reports of vertigo, tinnitus or hearing loss after a mean period of 149 days following the whiplash injury. No patients reported otological or persistent vestibular symptoms in the acute phase following their whiplash injury. This suggests that caution should be exercised when attributing these symptoms to such an injury. Before whiplash injuries are admitted as an aetiological factor in the development of such symptoms, other causes should be excluded.

  2. 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

  3. 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.

  4. 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

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

    Directory of Open Access Journals (Sweden)

    Brahim Tighilet

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

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

    Science.gov (United States)

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

    2017-01-01

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

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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 ...

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

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    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.

  13. 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....

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

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    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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. EL SINDROME VESTIBULAR EN EL ADULTO MAYOR

    Directory of Open Access Journals (Sweden)

    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.

  5. 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.

  6. Common clinical features of children with enlarged vestibular aqueduct and Mondini dysplasia.

    Science.gov (United States)

    Wu, Chen-Chi; Chen, Yuh-Shyang; Chen, Pei-Jer; Hsu, Chuan-Jen

    2005-01-01

    The purpose of the study was to investigate the etiological factors and the audiological data of different types of inner ear malformations, which the authors thought might be helpful in elucidating the inter-relation among malformations and shedding light on pathogenesis. Retrospective study from 1998 to 2002 at a tertiary care university hospital. One hundred sixty consecutive children with a total of 302 affected ears undergoing high-resolution computed tomography of the temporal bone for sensorineural hearing loss were enrolled. The image results were correlated with causes and origins, hearing loss patterns, hearing levels, and audiogram configurations. Inner ear malformation was present in 114 (38%) ears. The most common malformations were enlarged vestibular aqueduct, incomplete partition of cochlea (Mondini dysplasia), large vestibule, and semicircular canal dysplasia, presenting either as isolated finding or in combination. Eighty-four (74%) ears had abnormalities confined to these four malformations; only 30 (26%) ears showed other malformations. Patients with complex of enlarged vestibular aqueduct, Mondini dysplasia, large vestibule, and semicircular canal dysplasia (EMVS complex) demonstrated a significantly higher incidence of fluctuating hearing loss (93%) and a better hearing level compared with those with other malformations. Homogeneity in audiological features among these four malformations was also disclosed. The authors identified a distinct clinical entity, the EMVS complex, which is characterized by fluctuating hearing loss and a better hearing level. The authors proposed that malformations belonging to this complex result from a common pathogenetic mechanism.

  7. Characterization of 380nm UV-LEDs grown on free-standing GaN by atmospheric-pressure metal-organic chemical vapor deposition

    Science.gov (United States)

    Shieh, C. Y.; Li, Z. Y.; Kuo, H. C.; Chang, J. Y.; Chi, G. C.

    2014-03-01

    We reported the defects and optical characterizations of the ultraviolet light-emitting diodes grown on free-standing GaN substrate (FS-GaN) and sapphire. Cross-sectional transmission electron microscopy (TEM) images showed that the total defect densities of grown UV LEDs on FS-GaN and sapphire including edge, screw and mixed type were 3.6×106 cm-2 and 5.5×108 cm-2. When substrate of UV LEDs was changed from sapphire to FS-GaN, it can be clearly found that the crystallography of GaN epilayers was drastically different from that GaN epilayers on sapphire. Besides, the microstructures or indium clustering can be not observed at UV LEDs on FS-GaN from TEM measurement. The internal quantum efficiency of UVLEDs on FS-GaN and sapphire were 34.8 % and 39.4 % respectively, which attributed to indium clustering in multi-layers quantum wells (MQWs) of UV LEDs on sapphire. The relationship between indiumclustering and efficiency droop were investigated by temperature-dependent electroluminescence (TDEL) measurements.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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

  10. Adaptive Changes in the Vestibular System of Land Snail to a 30-Day Spaceflight and Readaptation on Return to Earth

    Directory of Open Access Journals (Sweden)

    Nikolay Aseyev

    2017-11-01

    Full Text Available The vestibular system receives a permanent influence from gravity and reflexively controls equilibrium. If we assume gravity has remained constant during the species' evolution, will its sensory system adapt to abrupt loss of that force? We address this question in the land snail Helix lucorum exposed to 30 days of near weightlessness aboard the Bion-M1 satellite, and studied geotactic behavior of postflight snails, differential gene expressions in statocyst transcriptome, and electrophysiological responses of mechanoreceptors to applied tilts. Each approach revealed plastic changes in the snail's vestibular system assumed in response to spaceflight. Absence of light during the mission also affected statocyst physiology, as revealed by comparison to dark-conditioned control groups. Readaptation to normal tilt responses occurred at ~20 h following return to Earth. Despite the permanence of gravity, the snail responded in a compensatory manner to its loss and readapted once gravity was restored.

  11. 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)

  12. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. 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.

  16. [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.

  17. 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

  18. 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

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

    OpenAIRE

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

    2018-01-01

    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 Ve...

  20. Vestibular system paresis due to emergency endovascular catheterization

    Directory of Open Access Journals (Sweden)

    Simoceli, Lucinda

    2012-01-01

    Full Text Available Objective: The objective of this story of case is to describe an uncommon cause of associated peripheral Vestibulopathy to the unilateral auditory loss in aged patient after catheterization of urgency. Story of case: Patient of the masculine sort, 82 years, submitted to the correction of abdominal ragged aneurism of aorta, in the intra-operative suffered heart attack acute from the myocardium needing primary angioplasty. High after hospital it relates to complaint of accented hearing loss to the right and crippling vertigo, without focal neurological signals. To the otorhinolaryngological clinical examination it presented: Test of Weber lateralized for the left, spontaneous nystagmus for the left, marches rocking, has taken normal disbasia and ataxia, index-nose and diadochokinesia, Test of Romberg with oscillation without fall and Fukuda with lateral shunting line for the right. The audiometric examination evidenced deafness to the right and sensorineural loss to the left in sharps, areflexia initial to the right in caloric test e, the computerized tomography of the secular bones and brainstem, presence of metallic connecting rod crossing the right secular bone, from the vein internal jugular vein and bulb jugular vein, crossing the posterior, superior and vestibule semicircular canals, projecting itself in temporal lobe. The radiological diagnoses was traumatic injury for guide to endovascular metallic during catheterization of urgency and the behavior, considering that the patient had not compensated the balance, it was vestibular rehabilitation. Conclusion: Complaints of giddiness in the aged patient must be closely evaluated of its pathological clinical description because the antecedents of illnesses and previous treatments, in general, direct the diagnostic hypotheses however they can bring unexpected alterations.

  1. Vestibular system paresis due to emergency endovascular catheterization.

    Science.gov (United States)

    Simoceli, Lucinda; Sguillar, Danilo Anunciatto; Santos, Henrique Mendes Paiva; Caputti, Camilla

    2012-04-01

     The objective of this story of case is to describe an uncommon cause of associated peripheral Vestibulopathy to the unilateral auditory loss in aged patient after catheterization of urgency. Story of case: Patient of the masculine sort, 82 years, submitted to the correction of abdominal ragged aneurism of aorta, in the intra-operative suffered heart attack acute from the myocardium needing primary angioplasty. High after hospital it relates to complaint of accented hearing loss to the right and crippling vertigo, without focal neurological signals. To the otorhinolaryngological clinical examination it presented: Test of Weber lateralized for the left, spontaneous nystagmus for the left, marches rocking, has taken normal disbasia and ataxia, index-nose and diadochokinesia, Test of Romberg with oscillation without fall and Fukuda with lateral shunting line for the right. The audiometric examination evidenced deafness to the right and sensorineural loss to the left in sharps, areflexia initial to the right in caloric test e, the computerized tomography of the secular bones and brainstem, presence of metallic connecting rod crossing the right secular bone, from the vein internal jugular vein and bulb jugular vein, crossing the posterior, superior and vestibule semicircular canals, projecting itself in temporal lobe. The radiological diagnoses was traumatic injury for guide to endovascular metallic during catheterization of urgency and the behavior, considering that the patient had not compensated the balance, it was vestibular rehabilitation.  Complaints of giddiness in the aged patient must be closely evaluated of its pathological clinical description because the antecedents of illnesses and previous treatments, in general, direct the diagnostic hypotheses however they can bring unexpected alterations.

  2. Genetic inactivation of Trpml3 does not lead to hearing and vestibular impairment in mice.

    Directory of Open Access Journals (Sweden)

    Simone Jörs

    2010-12-01

    Full Text Available TRPML3, a member of the transient receptor potential (TRP family, is an inwardly rectifying, non-selective Ca2+-permeable cation channel that is regulated by extracytosolic Na+ and H+ and can be activated by a variety of small molecules. The severe auditory and vestibular phenotype of the TRPML3(A419P varitint-waddler mutation made this protein particularly interesting for inner ear biology. To elucidate the physiological role of murine TRPML3, we conditionally inactivated Trpml3 in mice. Surprisingly, lack of functional TRPML3 did not lead to circling behavior, balance impairment or hearing loss.

  3. Congenital sensorineural hearing loss

    International Nuclear Information System (INIS)

    Mafee, M.F.; Selis, J.E.; Yannias, D.A.; Valvassori, G.E.; Pruzansky, S.; Applebaum, E.L.; Capek, V.

    1984-01-01

    The ears of 47 selected patients with congenital sensorineural hearing loss were examined with complex-motion tomography. The patients were divided into 3 general categories: those with a recognized syndrome, those with sensorineural hearing loss unrelated to any known syndrome, and those with microtia. A great variety of inner ear anomalies was detected, but rarely were these characteristic of a particular clinical entity. The most common finding was the Mondini malformation or one of its variants. Isolated dysplasia of the internal auditory canal or the vestibular aqueduct may be responsible for sensorineural hearing loss in some patients. Patients with microtia may also have severe inner ear abnormalities despite the fact that the outer and inner ears develop embryologically from completely separate systems

  4. Congenital sensorineural hearing loss

    Energy Technology Data Exchange (ETDEWEB)

    Mafee, M.F.; Selis, J.E.; Yannias, D.A.; Valvassori, G.E.; Pruzansky, S.; Applebaum, E.L.; Capek, V.

    1984-02-01

    The ears of 47 selected patients with congenital sensorineural hearing loss were examined with complex-motion tomography. The patients were divided into 3 general categories: those with a recognized syndrome, those with sensorineural hearing loss unrelated to any known syndrome, and those with microtia. A great variety of inner ear anomalies was detected, but rarely were these characteristic of a particular clinical entity. The most common finding was the Mondini malformation or one of its variants. Isolated dysplasia of the internal auditory canal or the vestibular aqueduct may be responsible for sensorineural hearing loss in some patients. Patients with microtia may also have severe inner ear abnormalities despite the fact that the outer and inner ears develop embryologically from completely separate systems.

  5. 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.

  6. 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.

  7. Improved results for vestibular schwannoma radiosurgery

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. 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

  9. Effectiveness of Vestibular Rehabilitation Therapy for Treatment of Concussed Adolescents With Persistent Symptoms of Dizziness and Imbalance.

    Science.gov (United States)

    Park, Kyoungyoun; Ksiazek, Thomas; Olson, Bernadette

    2018-05-04

    Adolescents who suffer sport concussion typically respond to a prescription of cognitive and physical rest in the acute phases of healing; however, some adolescents do not respond to rest alone. Dizziness, unsteadiness, and imbalance are impairments, which may linger longer than 30 days, leading to a diagnosis of postconcussion syndrome (PCS). Vestibular assessment and therapy may benefit adolescents suffering from these persistent symptoms. Does vestibular rehabilitation therapy (VRT) rather than continued prescription of rest (cognitive and physical) reduce recovery time and persistent symptoms of dizziness, unsteadiness, and imbalance in adolescents (12-18 y) who suffer PCS following a sports-related concussion? Summary of Key Findings: All 4 studies selected included adolescents suffering from PCS, specifically continued dizziness, unsteadiness, and imbalance. VRT was an effective intervention for this population. Adolescents presenting with this cluster of symptoms may also demonstrate verbal and visual memory loss linked to changes in the vestibular system postconcussion. Improved screening tools can help better understand vestibular system changes, identify adolescents who may benefit from VRT sooner, and decrease long-term impairments. Clinical Bottom Line: Moderate evidence supports that adolescents who suffer from persistent symptoms of dizziness, unsteadiness, and imbalance following sport concussion should be evaluated more specifically and earlier for vestibular dysfunction and can benefit from participation in individualized VRT. Early evaluation and treatment may result in a reduction of time lost from sport as well as a return to their premorbid condition. For these adolescents, VRT may be more beneficial than continued physical and cognitive rest when an adolescent's symptoms last longer than 30 days. Strength of Recommendation: Grade B evidence exists to support that VRT is more effective than continued cognitive and physical rest in reducing

  10. 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 receive direct sensory input from peripheral afferents. To infer whether asymmetric projections can facilitate sensory encoding or motor output, we modeled differentially projecting sets of central vestibular neurons. Whereas motor command strength was independent of projection allocation, asymmetric projections enabled more accurate representation of nose-up stimuli. The model shows how asymmetric connectivity could enhance the representation of imbalance during nose-up postures while preserving gaze stabilization performance. Finally, we found that central vestibular neurons were necessary for a vital behavior requiring maintenance of a nose-up posture: swim bladder inflation. These observations suggest that asymmetric connectivity in the vestibular system facilitates representation of ethologically relevant stimuli without

  11. 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.

  12. 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.

  13. 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.

  14. 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...

  15. 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.

  16. 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...

  17. 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...

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

    Science.gov (United States)

    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

    2015-06-01

    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 demonstrate the viability of the tissue and labeling with specific markers of hair cell function and of ion homeostasis in the epithelium. Samples obtained from the oldest patients revealed a significant loss of hair cells across the tissue surface, but we found immature hair bundles present in epithelia harvested from patients >60 years of age. These results suggest that the environment of the human vestibular sensory epithelium could be responsive to stimulation of developmental pathways to enhance hair cell regeneration, as has been demonstrated successfully in the vestibular organs of adult mice. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  19. 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

  20. Conservative management of vestibular schwannoma--a prospective cohort study: treatment, symptoms, and quality of life.

    Science.gov (United States)

    Breivik, Cathrine Nansdal; Varughese, Jobin K; Wentzel-Larsen, Tore; Vassbotn, Flemming; Lund-Johansen, Morten

    2012-05-01

    One hundred ninety-three patients with sporadic unilateral vestibular schwannoma given conservative management were enrolled in a prospective study. To evaluate the efficacy of conservative management and to determine the effect of an initial conservative management on the quality of life (QOL) and severity of audio vestibular symptoms. The patients underwent magnetic resonance imaging scans, clinical examination, and QOL assessment by 2 validated questionnaires, the Short Form-36 (SF-36) and Glasgow Benefit Inventory (GBI). Using regression analysis of clustered data, we analyzed possible associations between tumor growth and symptoms and tested whether our earlier finding that vertigo is associated with reduced QOL could be verified. The median follow-up time was 43 months (range, 9-115 months; SD, 21.48 months). Results are based on 703 clinical controls and 642 (SF-36) and 638 (GBI) questionnaires. Seven patients were lost to follow-up. Approximately 40% of patients were in need of treatment during follow-up. We found a statistically significant association between tinnitus and vertigo and tumor growth. Vertigo was found to significantly reduce QOL. There was a significant drop in the Social Function subscales of both SF-36 and GBI, possibly attributable to progressive hearing loss. Otherwise, there was no overall trend toward any change in QOL during the observation period. In addition, QOL seemed to be little affected by treatment. There was a small but statistically significant improvement in vestibular complaints and no change in the occurrence of tinnitus. Except for hearing loss caused by surgery, treatment did not affect symptoms or QOL significantly. Growth was associated with the occurrence of tinnitus and balance problems.

  1. 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.

  2. 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

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

    Directory of Open Access Journals (Sweden)

    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

  4. 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.

  5. Definition of fluctuant hearing loss.

    Science.gov (United States)

    Shea, J J

    1975-06-01

    In summary, fluctuant hearing loss is defined as a disorder of the inner ear characterized by fullness, roaring tinnitus, and fluctuations in hearing. It is believed to be caused by an inadequate absorption of endolymph from the endolymphatic sac, with or without one or more metabolic disorders, that interferes with the delicate balance between the production and absorption of endolymph and thus produces cochlear hydrops. This triad of fullness, roaring tinnitus, and fluctuant hearing loss resulting from cochlear hydrops is much more common than the quadrad of true turning vertigo, fullness, roaring tinnitus, and fluctuant hearing loss due to vestibular and cochlear hydrops known as Meniere's disease. Although patients with fluctuant hearing loss only may eventually develop vertigo as the chief complaint and then be said to have Meniere's disease, it is remarkable how many patients continue to suffer mainly from cochlear symptoms at all times. It would appear, because of the greater frequency of fluctuant hearing loss than in Meniere's disease, that the cochlear labyrinth is more susceptible to hydrops than the vestibular labyrinth. For the purposes of diagnosis and treatment it is very useful to separate patients into those with fluctuant hearing loss and those with Meniere's disease.

  6. 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.

  7. Progression of changes in the sensorial elements of the cochlear and peripheral vestibular systems: The otitis media continuum.

    Science.gov (United States)

    Monsanto, Rafael da Costa; Schachern, Patricia; Paparella, Michael M; Cureoglu, Sebahattin; Penido, Norma de Oliveira

    2017-08-01

    Our study aimed to evaluate pathologic changes in the cochlear (inner and outer hair cells and stria vascularis) and vestibular (vestibular hair cells, dark, and transitional cells) sensorial elements in temporal bones from donors who had otitis media. We studied 40 temporal bones from such donors, which were categorized in serous otitis media (SOM), serous-purulent otitis media (SPOM), mucoid/mucoid-purulent otitis media (MOM/MPOM), and chronic otitis media (COM); control group comprised 10 nondiseased temporal bones. We found significant loss of inner and outer cochlear hair cells in the basal turn of the SPOM, MOM/MPOM and COM groups; significant loss of vestibular hair cells was observed in the MOM/MPOM and COM groups. All otitis media groups had smaller mean area of the stria vascularis in the basal turn of the cochlea when compared to controls. In conclusion, our study demonstrated more severe pathologic changes in the later stages of the continuum of otitis media (MOM/MPOM and COM). Those changes seem to progress from the basal turn of the cochlea (stria vascularis, then inner and outer hair cells) to the middle turn of the cochlea and to the saccule and utricle in the MOM/MPOM and COM stages. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Post-operative complications after removal of sporadic vestibular schwannoma via retrosigmoid-suboccipital approach: current diagnosis and management.

    Science.gov (United States)

    Charalampakis, Stylianos; Koutsimpelas, Dimitrios; Gouveris, Haralampos; Mann, Wolf

    2011-05-01

    The retrosigmoid (suboccipital) approach is one of four surgical approaches for the treatment of vestibular schwannomas (acoustic neuromas). It is increasingly used by otologic surgeons, and in experienced hands is associated with improved results and more limited complications. Mortality rates are minimal and often zero, while postoperative sequelae, on the other hand, are not rare. In order to not only save the patient's life, but also to assure good quality of life after the surgery, one must consider many different aspects of management of the respective complications. In this review the issues of current management of CSF leak and meningitis, facial paresis, headache, hearing loss, unsteadiness, disequilibrium, vertigo, tinnitus, cerebellar and brain stem injuries or abscess, vascular complications and venous air embolism after retrosigmoid approach for removal of vestibular schwannomas are presented. © Springer-Verlag 2011

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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

  15. Age, gender and tumour size predict work capacity after surgical treatment of vestibular schwannomas.

    Science.gov (United States)

    Al-Shudifat, Abdul Rahman; Kahlon, Babar; Höglund, Peter; Soliman, Ahmed Y; Lindskog, Kristoffer; Siesjo, Peter

    2014-01-01

    The aim of the present study was to identify predictive factors for outcome after surgery of vestibular schwannomas. This is a retrospective study with partially collected prospective data of patients who were surgically treated for vestibular schwannomas at a single institution from 1979 to 2000. Patients with recurrent tumours, NF2 and those incapable of answering questionnaires were excluded from the study. The short form 36 (SF36) questionnaire and a specific questionnaire regarding neurological status, work status and independent life (IL) status were sent to all eligible patients. The questionnaires were sent to 430 eligible patients (out of 537) and 395 (93%) responded. Scores for work capacity (WC) and IL were compared with SF36 scores as outcome estimates. Patients were divided into two groups (group age, gender and tumour diameter were independent predictive factors for postoperative WC in multivariate analysis. A high-risk group was identified in women with age >50 years and tumour diameter >25 mm. In patients ≥64, gender and tumour diameter were significant predictive factors for IL in univariate analysis. Perioperative and postoperative objective factors as length of surgery, blood loss and complications did not predict outcome in the multivariable analysis for any age group. Patients' assessment of change in balance function was the only neurological factor that showed significance both in univariate and multivariable analysis in both age cohorts. While SF36 scores were lower in surgically treated patients in relation to normograms for the general population, they did not correlate significantly to WC and IL. The SF36 questionnaire did not correlate to outcome measures as WC and IL in patients undergoing surgery for vestibular schwannomas. Women and patients above 50 years with larger tumours have a high risk for reduced WC after surgical treatment. These results question the validity of quality of life scores in assessment of outcome after surgery

  16. Subjective visual horizontal during follow-up after unilateral vestibular deafferentation with gentamicin.

    Science.gov (United States)

    Tribukait, A; Bergenius, J; Brantberg, K

    1998-07-01

    The subjective visual horizontal (SVH) was measured by means of a small, rotatable, luminous line in darkness in the upright head and body position and at 10, 20 and 30 degrees of tilt to the right and left before, and repeatedly during a follow-up period of 1 year after intratympanic gentamicin instillations in 12 patients with recurrent vertigo attacks. This treatment caused a loss of the bithermal caloric responses on the diseased side. Shortly after treatment there was a significant tilt of SVH towards the treated side (group mean = 10.6 degrees). Repeated testing made it possible to characterize mathematically the changes with time for SVH. For the group of patients as a whole this otolithic component of vestibular compensation was best described by a power function, SVH = 8.65t(-0.16) degrees, where t is time in days after maximum tilt of SVH. After 1 year, SVH was still significantly tilted towards the treated side (group mean = 3.16 degrees). Gentamicin treatment also caused a significant reduction in the perception of head and body tilt towards the deafferented side, while the perception of tilt towards the healthy side did not show any significant changes. During follow-up there was a gradual improvement in the perception of tilt towards the treated side. However, a significant asymmetry in roll-tilt perception was still present 1 year after deafferentation. There was no correlation between SVH in the upright position and roll-tilt perception, suggesting that these parameters are to some extent dependent on different afferent input from the vestibular organ. They were also found to be complementary for the detection of vestibular disturbance.

  17. 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

  18. Acute necrosis after Gamma Knife surgery in vestibular schwannoma leading to multiple cranial nerve palsies.

    Science.gov (United States)

    Kapitza, Sandra; Pangalu, Athina; Horstmann, Gerhard A; van Eck, Albert T; Regli, Luca; Tarnutzer, Alexander A

    2016-08-01

    We discuss a rare acute complication after Gamma Knife therapy (Elekta AB, Stockholm, Sweden) in a single patient. A 52-year-old woman presented with vertigo, facial weakness and hearing loss emerging 48hours following Gamma Knife radiosurgery for a right-sided vestibular schwannoma. Neurological examination 6days after symptom onset showed right-sided facial palsy, spontaneous left-beating nystagmus and pathologic head-impulse testing to the right. Pure-tone audiogram revealed right-sided sensorineural hearing loss. A diagnosis of acute vestibulocochlear and facial neuropathy was made. Brain MRI demonstrated focal contrast sparing within the schwannoma, likely related to acute radiation necrosis. Acute multiple cranial neuropathies of the cerebellopontine angle after Gamma Knife treatment should raise suspicion of acute tissue damage within the schwannoma and should result in urgent MRI. Treatment with steroids may be considered based on accompanying swelling and edema. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Unilateral vestibular deafferentation-induced changes in calcium signaling-related molecules in the rat vestibular nuclear complex.

    Science.gov (United States)

    Masumura, Chisako; Horii, Arata; Mitani, Kenji; Kitahara, Tadashi; Uno, Atsuhiko; Kubo, Takeshi

    2007-03-23

    Inquiries into the neurochemical mechanisms of vestibular compensation, a model of lesion-induced neuronal plasticity, reveal the involvement of both voltage-gated Ca(2+) channels (VGCC) and intracellular Ca(2+) signaling. Indeed, our previous microarray analysis showed an up-regulation of some calcium signaling-related genes such as the alpha2 subunit of L-type calcium channels, calcineurin, and plasma membrane Ca(2+) ATPase 1 (PMCA1) in the ipsilateral vestibular nuclear complex (VNC) following unilateral vestibular deafferentation (UVD). To further elucidate the role of calcium signaling-related molecules in vestibular compensation, we used a quantitative real-time polymerase chain reaction (PCR) method to confirm the microarray results and investigated changes in expression of these molecules at various stages of compensation (6 h to 2 weeks after UVD). We also investigated the changes in gene expression during Bechterew's phenomenon and the effects of a calcineurin inhibitor on vestibular compensation. Real-time PCR showed that genes for the alpha2 subunit of VGCC, PMCA2, and calcineurin were transiently up-regulated 6 h after UVD in ipsilateral VNC. A subsequent UVD, which induced Bechterew's phenomenon, reproduced a complete mirror image of the changes in gene expressions of PMCA2 and calcineurin seen in the initial UVD, while the alpha2 subunit of VGCC gene had a trend to increase in VNC ipsilateral to the second lesion. Pre-treatment by FK506, a calcineurin inhibitor, decelerated the vestibular compensation in a dose-dependent manner. Although it is still uncertain whether these changes in gene expression are causally related to the molecular mechanisms of vestibular compensation, this observation suggests that after increasing the Ca(2+) influx into the ipsilateral VNC neurons via up-regulated VGCC, calcineurin may be involved in their synaptic plasticity. Conversely, an up-regulation of PMCA2, a brain-specific Ca(2+) pump, would increase an efflux of Ca

  20. 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.

  1. Stereotactic radiation therapy for large vestibular schwannomas

    International Nuclear Information System (INIS)

    Mandl, Ellen S.; Meijer, Otto W.M.; Slotman, Ben J.; Vandertop, W. Peter; Peerdeman, Saskia M.

    2010-01-01

    Background and purpose: To evaluate the morbidity and tumor-control rate in the treatment of large vestibular schwannomas (VS) after stereotactic radiation therapy in our institution. Material and methods: Twenty-five consecutive patients (17 men, 8 women) with large VS (diameter 3.0 cm or larger), treated with stereotactic radiotherapy (SRT) or stereotactic radiosurgery (SRS) between 1992 and 2007, were retrospectively studied after a mean follow-up period of three years with respect to tumor-control rate and complications. Results: Actuarial 5-year maintenance of pre-treatment hearing level probability of 30% was achieved. Five of 17 patients suffered permanent new facial nerve dysfunction. The actuarial 5-year facial nerve preservation probability was 80%. Permanent new trigeminal nerve neuropathy occurred in two of 15 patients, resulting in an actuarial 5-year trigeminal nerve preservation probability of 85%. Tumor progression occurred in four of 25 (16%) patients. The overall 5-year tumor control probability was 82%. Conclusion: Increased morbidity rates were found in patients with large VS treated with SRT or SRS compared to the published series on regular sized VS and other smaller retrospective studies on large VS.

  2. Cost-effective analysis of unilateral vestibular weakness investigation.

    Science.gov (United States)

    Gandolfi, Michele M; Reilly, Erin K; Galatioto, Jessica; Judson, Randy B; Kim, Ana H

    2015-02-01

    To evaluate the cost-effectiveness of obtaining a magnetic resonance imaging (MRI) in patients with abnormal electronystagmography (ENG) or videonystagmography (VNG) results. Retrospective chart review. Academic specialty center. Patients presenting with vertigo between January 1, 2010, and August 30, 2013. Patients who fit the following abnormal criteria were included in the study: unilateral caloric weakness (≥20%), abnormal ocular motor testing, and nystagmus on positional testing. Patients with abnormal findings who then underwent MRI with gadolinium were evaluated. Of the 1,996 charts reviewed, there were 1,358 patients who met the inclusion criteria. The average age of these patients was 62 years (12-94 yr). The male:female ratio was approximately 1:2. Of the 1,358 patients, 253 received an MRI with the following pathologies: four vestibular schwannomas, three subcortical/periventricular white matter changes suspicious for demyelinating disease, four acute cerebellar/posterior circulation infarct, two vertebral artery narrowing, one pseudomeningocele of internal auditory canal, and two white matter changes indicative of migraines. The positive detection rate on MRI was 5.5% based on MRI findings of treatable pathologies causing vertigo. Average cost of an MRI is $1,200, thereby making the average cost of identifying a patient with a positive MRI finding $15,180. In our study, those patients with a positive MRI had a constellation of symptoms and findings (asymmetric sensorineural hearing loss, tinnitus, vertigo, and abnormal ENG/VNG). Cost-effectiveness can be improved by ordering an MRI only when clinical examination and VNG point toward a central pathology. Clinical examination and appropriate testing should be factored when considering the cost-effectiveness of obtaining an MRI in patients with abnormal ENG/VNG findings.

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

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    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.

  4. 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.

  5. 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.

  6. 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.

  7. Predictors of Preoperative Tinnitus in Unilateral Sporadic Vestibular Schwannoma

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    Georgios Naros

    2017-08-01

    Full Text Available ObjectiveNearly two-thirds of patients with vestibular schwannoma (VS are reporting a significantly impaired quality of life due to tinnitus. VS-associated tinnitus is attributed to an anatomical and physiological damage of the hearing nerve by displacing growth of the tumor. In contrast, the current pathophysiological concept of non-VS tinnitus hypothesizes a maladaptive neuroplasticity of the central nervous system to a (hidden hearing impairment resulting in a subjective misperception. However, it is unclear whether this concept fits to VS-associated tinnitus. This study aims to determine the clinical predictors of VS-associated tinnitus to ascertain the compatibility of both pathophysiological concepts.MethodsThis retrospective study includes a group of 478 neurosurgical patients with unilateral sporadic VS evaluated preoperatively regarding the occurrence of ipsilateral tinnitus depending on different clinical factors, i.e., age, gender, tumor side, tumor size (T1–T4 according to the Hannover classification, and hearing impairment (Gardner–Robertson classification, GR1–5, using a binary logistic regression.Results61.8% of patients complain about a preoperative tinnitus. The binary logistic regression analysis identified male gender [OR 1.90 (1.25–2.75; p = 0.002] and hearing impairment GR3 [OR 1.90 (1.08–3.35; p = 0.026] and GR4 [OR 8.21 (2.29–29.50; p = 0.001] as positive predictors. In contrast, patients with large T4 tumors [OR 0.33 (0.13–0.86; p = 0.024] and complete hearing loss GR5 [OR 0.36 (0.15–0.84; p = 0.017] were less likely to develop a tinnitus. Yet, 60% of the patients with good clinical hearing (GR1 and 25% of patients with complete hearing loss (GR5 suffered from tinnitus.ConclusionThese data are good accordance with literature about non-VS tinnitus indicating hearing impairment as main risk factor. In contrast, complete hearing loss appears a negative predictor for tinnitus. For the first

  8. Directional plasticity rapidly improves 3D vestibulo-ocular reflex alignment in monkeys using a multichannel vestibular prosthesis.

    Science.gov (United States)

    Dai, Chenkai; Fridman, Gene Y; Chiang, Bryce; Rahman, Mehdi A; Ahn, Joong Ho; Davidovics, Natan S; Della Santina, Charles C

    2013-12-01

    Bilateral loss of vestibular sensation can be disabling. We have shown that a multichannel vestibular prosthesis (MVP) can partly restore vestibular sensation as evidenced by improvements in the 3-dimensional angular vestibulo-ocular reflex (3D VOR). However, a key challenge is to minimize misalignment between the axes of eye and head rotation, which is apparently caused by current spread beyond each electrode's targeted nerve branch. We recently reported that rodents wearing a MVP markedly improve 3D VOR alignment during the first week after MVP activation, probably through the same central nervous system adaptive mechanisms that mediate cross-axis adaptation over time in normal individuals wearing prisms that cause visual scene movement about an axis different than the axis of head rotation. We hypothesized that rhesus monkeys would exhibit similar improvements with continuous prosthetic stimulation over time. We created bilateral vestibular deficiency in four rhesus monkeys via intratympanic injection of gentamicin. A MVP was mounted to the cranium, and eye movements in response to whole-body passive rotation in darkness were measured repeatedly over 1 week of continuous head motion-modulated prosthetic electrical stimulation. 3D VOR responses to whole-body rotations about each semicircular canal axis were measured on days 1, 3, and 7 of chronic stimulation. Horizontal VOR gain during 1 Hz, 50 °/s peak whole-body rotations before the prosthesis was turned on was prosthetic stimulation under normal diurnal lighting. Similar improvements were noted for all animals, all three axes of rotation tested, for all sinusoidal frequencies tested (0.05-5 Hz), and for high-acceleration transient rotations. VOR asymmetry changes did not reach statistical significance, although they did trend toward slight improvement over time. Prior studies had already shown that directional plasticity reduces misalignment when a subject with normal labyrinths views abnormal visual scene

  9. Extremely discrepant mutation spectrum of SLC26A4 between Chinese patients with isolated Mondini deformity and enlarged vestibular aqueduct.

    Science.gov (United States)

    Huang, Shasha; Han, Dongyi; Yuan, Yongyi; Wang, Guojian; Kang, Dongyang; Zhang, Xin; Yan, Xiaofei; Meng, Xiaoxiao; Dong, Min; Dai, Pu

    2011-09-30

    Mutations in SLC26A4 cause Pendred syndrome (hearing loss with goiter) or DFNB4 (non-syndromic hearing loss with inner ear malformation, such as enlarged vestibular aqueduct or Mondini deformity). The relationship between mutations in SLC26A4 and Mondini deformity without enlarged vestibular aqueduct has not been studied in any Chinese deaf population. The purpose of this study was to assess whether mutations in the SLC26A4 gene cause Mondini deformity without an enlarged vestibular aqueduct (isolated Mondini deformity) in a Chinese population. In total, 144 patients with sensorineural hearing loss were included and subjected to high-resolution temporal bone CT. Among them, 28 patients with isolated Mondini dysplasia (MD group), 50 patients with enlarged vestibular aqueduct with Mondini dysplasia (EVA with MD group), 50 patients with enlarged vestibular aqueduct without Mondini dysplasia (EVA group), and 16 patients with other types of inner ear malformations (IEM group) were identified. The coding exons of SLC26A4 were analyzed in all subjects. DNA sequence analysis of SLC26A4 was performed in all 144 patients. In the different groups, the detection rate of the SLC26A4 mutation differed. In the isolated MD group, only one single allelic mutation in SLC26A4 was found in one patient (1/28, 3.6%). In the EVA with MD group, biallelic and monoallelic SLC26A4 mutations were identified in 46 patients (46/50, 92.0%) and three patients (3/50, 6.0%), respectively. Also, in the EVA group, biallelic and monoallelic SLC26A4 mutations were identified in 46 patients (46/50, 92.0%) and three patients (3/50, 6.0%), respectively. These percentages were identical to those in the EVA plus MD group. Only two patients carried monoallelic mutations of the SLC26A4 gene in the IEM group (2/16, 12.5%). There were significant differences in the frequency of SLC26A4 mutation among the groups (P0.5). Although mutations in the SLC26A4 gene were frequently found in Chinese EVA patients with and

  10. 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.

  11. 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.

  12. 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

  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. Vestibular evoked myogenic potentials and digital vectoelectronystagmography's study in patients with benign paroxysmal positional vertigo

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    Lira-Batista, Marta Maria da Silva

    2013-04-01

    Full Text Available Introduction: Benign Paroxysmal Positional Vertigo (BPPV is a very common vestibular disorder characterized by brief but intense attacks of rotatory vertigo triggered by simple rapid movement of the head. The integrity of the vestibular pathways can be assessed using tests such as digital vectoelectronystagmography (VENG and vestibular evoked myogenic potentials (VEMP. Aim: This study aimed to determine the VEMP findings with respect to latency, amplitude, and waveform peak to peak and the results of the oculomotor and vestibular components of VENG in patients with BPPV. Method: Although this otoneurological condition is quite common, little is known of the associated VEMP and VENG changes, making it important to research and describe these results. Results: We examined the records of 4438 patients and selected 35 charts after applying the inclusion and exclusion criteria. Of these, 26 patients were women and 9 men. The average age at diagnosis was 52.7 years, and the most prevalent physiological cause, accounting for 97.3% of cases, was ductolithiasis. There was a statistically significant association between normal hearing and mild contralateral sensorineural hearing loss. The results of the oculomotor tests were within the normal reference ranges for all subjects. Patients with BPPV exhibited symmetrical function of the semicircular canals in their synergistic pairs (p < 0.001. The caloric test showed statistically normal responses from the lateral canals. The waveforms of all patients were adequate, but the VEMP results for the data-crossing maneuver with positive positioning showed a trend toward a relationship for the left ear Lp13. There was also a trend towards an association between normal reflexes in the caloric test and the inter-peak VEMP of the left ear. It can be concluded that although there are some differences between the average levels of the VENG and VEMP results, these differences were not statistically significant

  15. Immunocytochemical and stereological analysis of GABA(B) receptor subunit expression in the rat vestibular nucleus following unilateral vestibular deafferentation.

    Science.gov (United States)

    Zhang, Rong; Ashton, John; Horii, Arata; Darlington, Cynthia L; Smith, Paul F

    2005-03-10

    The process of behavioral recovery that occurs following damage to one vestibular labyrinth, vestibular compensation, has been attributed in part to a down-regulation of GABA(B) receptors in the vestibular nucleus complex (VNC) ipsilateral to the lesion, which could potentially reduce commissural inhibition from the contralateral VNC. In this study, we tested the possibility that this occurs through a decrease in the expression of either the GABA(B1) or GABA(B2) subunits of the GABA(B) receptor. We used Western blotting to quantify the expression of these subunits in the VNC at 10 h and 50 h following unilateral vestibular deafferentation (UVD) or sham surgery in rats. We then used immunocytochemistry and stereological counting methods to estimate the number of neurons expressing these subunits in the MVN at 10 h and 2 weeks following UVD or sham surgery. Compared to sham controls, we found no significant changes in either the expression of the two GABA(B) receptor subunits in the VNC or in the number of MVN neurons expressing these GABA(B) receptor subunits post-UVD. These results suggest that GABA(B) receptor expression does not change substantially in the VNC during the process of vestibular compensation.

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

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    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

  17. The effects of aging on clinical vestibular evaluations

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    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.

  18. Visual gravitational motion and the vestibular system in humans

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    Francesco eLacquaniti

    2013-12-01

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

  19. Migraine patients consistently show abnormal vestibular bedside tests

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    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.

  20. 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.

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

    Science.gov (United States)

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

    2013-12-26

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

  2. Rapid adaptation of multisensory integration in vestibular pathways

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    Jerome eCarriot

    2015-04-01

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

  3. Continuous Hair Cell Turnover in the Inner Ear Vestibular Organs of a Mammal, the Daubenton's Bat (Myotis daubentonii)

    Science.gov (United States)

    Kirkegaard, M.; Jørgensen, J. M.

    In both humans and mice the number of hair cells in the inner ear sensory epithelia declines with age, indicating cell death (Park et al. 1987; Rosenhall 1973). However, recent reports demonstrate the ability of the vestibular sensory epithelia to regenerate after injury (Forge et al. 1993, 1998; Kuntz and Oesterle 1998; Li and Forge 1997; Rubel et al. 1995; Tanyeri et al. 1995). Still, a continuous hair cell turnover in the vestibular epithelia has not previously been demonstrated in mature mammals. Bats are the only flying mammals, and they are known to live to a higher age than animals of equal size. The maximum age of many species is 20years, with average lifespans of 4-6years (Schober and Grimmberger 1989). Further, the young are fully developed and able to fly at the age of 2months, and thus the vestibular organs are thought to be differentiated at that age. Consequently, long-lived mammals such as bats might compensate for the loss of hair cells by producing new hair cells in their postembryonic life. Here we show that the utricular macula of adult Daubenton's bats (more than 6months old) contains innervated immature hair cells as well as apoptotic hair cells, which strongly indicates a continuous turnover of hair cells, as previously demonstrated in birds.

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

    Science.gov (United States)

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

    2016-04-01

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

  5. 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).

  6. 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

  7. 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.

  8. 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.

  9. Kv1 channels and neural processing in vestibular calyx afferents

    Directory of Open Access Journals (Sweden)

    Frances L Meredith

    2015-06-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

  11. 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.

  12. Diagnostic criteria for enlarged vestibular aqueduct (EVA) on CT of the temporal bones. Borderline cases of EVA

    International Nuclear Information System (INIS)

    Matsumoto, Mariko; Hoshino, Tomoyuki; Kikura, Mikino; Kikawada, Keiko; Kikawada, Toru

    2005-01-01

    The objective of this study was to examine measurements of the vestibular aqueduct on axial CT figures and to examine the cases with borderline EVA. The width of the vestibular aqueduct was measured in two places, the midpoint of the duct and the external aperture in the posterior cranial fossa. Criteria was as follow: Enlargement; ≥1.5 mm at the midpoint, ≥2 mm at the aperture, Borderline; 1-1.4 mm at the midpoint, 1.5-1.9 mm at the aperture. Three hundred forty-five cases with CT scans of the temporal bones taken during July 2003 to June 2004 in the secondary ENT referral center. Those patients include sensorinearal, mixed or conductive deafness, vertigo, ear infections and other ear diseases. Enlarged vestibular aqueduct was found in 10 ears with sensorineural deafness (SD) and 2 ears without SD. Borderline measurements were found in 19 ears with SD and 33 ears without SD. The enlarged midpoint measurement was not seen in the cases without SD. More than 1.5 mm of the definition for the enlargement at the midpoint of the vestibular aqueduct seemed to be appropriate in the clinical situation. The measurement at the midpoint of the duct is more reliable than at the external aperture. The conductive component in EVA Syndrome with mixed hearing loss is present only at the lower frequencies (250, 500 Hz), not at the middle and higer frequencies. Long-term follow-up of hearing should be done in the borderline cases with check-up of PDS gene anomaly if necessary. (author)

  13. Repeat Gamma Knife surgery for vestibular schwannomas

    Science.gov (United States)

    Lonneville, Sarah; Delbrouck, Carine; Renier, Cécile; Devriendt, Daniel; Massager, Nicolas

    2015-01-01

    Background: Gamma Knife (GK) surgery is a recognized treatment option for the management of small to medium-sized vestibular schwannoma (VS) associated with high-tumor control and low morbidity. When a radiosurgical treatment fails to stop tumor growth, repeat GK surgery can be proposed in selected cases. Methods: A series of 27 GK retreatments was performed in 25 patients with VS; 2 patients underwent three procedures. The median time interval between GK treatments was 45 months. The median margin dose used for the first, second, and third GK treatments was 12 Gy, 12 Gy, and 14 Gy, respectively. Six patients (4 patients for the second irradiation and 2 patients for the third irradiation) with partial tumor regrowth were treated only on the growing part of the tumor using a median margin dose of 13 Gy. The median tumor volume was 0.9, 2.3, and 0.7 cc for the first, second, and third treatments, respectively. Stereotactic positron emission tomography (PET) guidance was used for dose planning in 6 cases. Results: Mean follow-up duration was 46 months (range 24–110). At the last follow-up, 85% of schwannomas were controlled. The tumor volume decreased, remained unchanged, or increased after retreatment in 15, 8, and 4 cases, respectively. Four patients had PET during follow-up, and all showed a significant metabolic decrease of the tumor. Hearing was not preserved after retreatment in any patients. New facial or trigeminal palsy did not occur after retreatment. Conclusions: Our results support the long-term efficacy and low morbidity of repeat GK treatment for selected patients with tumor growth after initial treatment. PMID:26500799

  14. A Stimulator ASIC Featuring Versatile Management for Vestibular Prostheses.

    Science.gov (United States)

    Dai Jiang; Demosthenous, Andreas; Perkins, Timothy; Xiao Liu; Donaldson, Nick

    2011-04-01

    This paper presents a multichannel stimulator ASIC for an implantable vestibular prosthesis. The system features versatile stimulation management which allows fine setting of the parameters for biphasic stimulation pulses. To address the problem of charge imbalance due to rounding errors, the digital processor can calculate and provide accurate charge correction. A technique to reduce the data rate to the stimulator is described. The stimulator ASIC was implemented in 0.6-μ m high-voltage CMOS technology occupying an area of 2.27 mm(2). The measured performance of the ASIC has been verified using vestibular electrodes in saline.

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

    Science.gov (United States)

    Dieterich, Marianne; Obermann, Mark; Celebisoy, Nese

    2016-04-01

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

  16. Focal increase of blood flow in the cerebral cortex of man during vestibular stimulation

    DEFF Research Database (Denmark)

    Friberg, L; Olsen, T S; Roland, P E

    1985-01-01

    This study is an attempt to reveal projection areas for vestibular afferents to the human brain. Changes in regional cerebral blood flow (rCBF) were measured over 254 cortical regions during caloric vestibular stimulation with warm water (44 degrees C). rCBF was measured when the external auditory...... meatus was irrigated with water at body temperature as a control to vestibular stimulation. During vestibular stimulation there was only a single cortical area, located in the superior temporal region, which showed a consistent focal activation in the hemisphere contralateral to the stimulated side...... stimulation that gives rise to the associated conscious vestibular sensation of vertigo....

  17. 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.

  18. 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.

  19. 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

  20. Vestibular schwannoma (acoustic neuroma mimicking temporomandibular disorders: a case report Schwannoma vestibular (neurinoma do acústico imitando desordens temporomandibulares: um relato de caso

    Directory of Open Access Journals (Sweden)

    Maurício A. Bisi

    2006-12-01

    Full Text Available 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.Aproximadamente 6 a 16% dos pacientes com sintomas de neuralgia trigeminal apresentam tumores intracranianos, sendo mais comum o schwannoma vestibular (neurinoma do acústico. Alguns sintomas relatados pelos pacientes são perda da audição, zumbido, dores de cabeça, vertigens e distúrbios trigeminais. Uma resposta muscular aumentada na musculatura associada da cabeça e do pescoço também pode ser observada, o que pode mimetizar sinais e sintomas de desordens temporomandibulares. Nestes casos é de grande valia o uso de imagem de ressonância magnética (IRM para detecção de tumores. É importante, também, a diferenciação de dores miofasciais e neurálgicas, pois ambas podem apresentar características semelhantes, mas com origens e tratamentos diferentes. O objetivo desse trabalho foi demonstrar através de relato de caso clínico a associação entre sintomas de neuralgia trigeminal, tumores intracranianos e disfunção temporomandibular.

  1. Scalar position in cochlear implant surgery and outcome in residual hearing and the vestibular system.

    Science.gov (United States)

    Nordfalk, Karl Fredrik; Rasmussen, Kjell; Hopp, Einar; Greisiger, Ralf; Jablonski, Greg Eigner

    2014-02-01

    To evaluate the effect of the intracochlear electrode position on the residual hearing and VNG- and cVEMP responses. Prospective pilot study. Thirteen adult patients who underwent unilateral cochlear implant surgery were examined with high-resolution rotational tomography after cochlear implantation. All subjects were also tested with VNG, and 12 of the subjects were tested with cVEMP and audiometry before and after surgery. We found that although the electrode was originally planned to be positioned inside the scala tympani, only 8 of 13 had full insertion into the scala tympani. Loss of cVEMP response occurred to the same extent in the group with full scala tympani positioning and the group with scala vestibuli involvement. There was a non-significant difference in the loss of caloric response and residual hearing between the two groups. Interscalar dislocation of the electrode inside the cochlea was observed in two patients. A higher loss of residual hearing could be seen in the group with electrode dislocation between the scalae. Our findings indicate that intracochlear electrode dislocation is a possible cause to loss of residual hearing during cochlear implantation but cannot be the sole cause of postoperative vestibular loss.

  2. 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.

  3. Task-dependent vestibular feedback responses in reaching

    NARCIS (Netherlands)

    Keyser, J.; Medendorp, W.P.; Selen, L.P.J.

    2017-01-01

    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

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. Photocatalytic decomposition of selected estrogens and their estrogenic activity by UV-LED irradiated TiO{sub 2} immobilized on porous titanium sheets via thermal-chemical oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Arlos, Maricor J., E-mail: mjarlos@uwaterloo.ca [Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Liang, Robert; Hatat-Fraile, Melisa M. [Centre for Advanced Materials Joining, Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Waterloo Institute of Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Bragg, Leslie M. [Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Zhou, Norman Y. [Centre for Advanced Materials Joining, Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Waterloo Institute of Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Servos, Mark R. [Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Andrews, Susan A. [Civil Engineering Department, University of Toronto, Toronto, Ontario M5S 1A4 (Canada)

    2016-11-15

    Highlights: • TiO{sub 2} self-assembled on oxidized porous titanium sheets. • UV-LED/TiO{sub 2} membrane treatment reduced the concentrations of estrogens. • Different pH conditions affect treatment efficiency. • The estrogenic activity removal was similar to the chemical disappearance. - Abstract: The removal of endocrine disrupting compounds (EDCs) remains a big challenge in water treatment. Risks associated with these compounds are not clearly defined and it is important that the water industry has additional options to increase the resiliency of water treatment systems. Titanium dioxide (TiO{sub 2}) has potential applications for the removal of EDCs from water. TiO{sub 2} has been immobilized on supports using a variety of synthesis methods to increase its feasibility for water treatment. In this study, we immobilized TiO{sub 2} through the thermal-chemical oxidation of porous titania sheets. The efficiency of the material to degrade target EDCs under UV-LED irradiation was examined under a wide range of pH conditions. A yeast-estrogen screen assay was used to complement chemical analysis in assessing removal efficiency. All compounds but 17β-estradiol were degraded and followed a pseudo first-order kinetics at all pH conditions tested, with pH 4 and pH 11 showing the most and the least efficient treatments respectively. In addition, the total estrogenic activity was substantially reduced even with the inefficient degradation of 17β-estradiol. Additional studies will be required to optimize different treatment conditions, UV-LED configurations, and membrane fouling mitigation measures to make this technology a more viable option for water treatment.

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

    Science.gov (United States)

    Lichtenberg, B K

    1988-01-01

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

  10. Stereotactic radiosurgery vs. fractionated radiotherapy for tumor control in vestibular schwannoma patients

    DEFF Research Database (Denmark)

    Persson, Oscar; Bartek, Jiri; Shalom, Netanel Ben

    2017-01-01

    OBJECTIVE: Repeated controlled studies have revealed that stereotactic radiosurgery is better than microsurgery for patients with vestibular schwannoma (VS) ... to patients treated with fractionated stereotactic radiotherapy. RESULTS: No randomized controlled trial (RCT) was identified. None of the identified controlled studies comparing SRS with FSRT were eligible according to the inclusion criteria. Nineteen case series on SRS (n = 17) and FSRT (n = 2) were...... included in the systematic review. Loss of tumor control necessitating a new VS-targeted intervention was found in an average of 5.0% of the patients treated with SRS and in 4.8% treated with FSRT. Mean deterioration ratio for patients with serviceable hearing before treatment was 49% for SRS and 45...

  11. MR imaging of the vestibular aqueduct in normal volunteers and patients with Meniere's disease

    International Nuclear Information System (INIS)

    Naganawa, Shinji; Asai, Hideaki; Ishigaki, Takeo; Sakuma, Sadayuki

    1991-01-01

    In this paper we attempted MR visualization of the vestibular aqueduct (VA) with a surface coil. Sagittal plane was most preferable from the result of preliminary study using a dry temporal bone. In all of ten normal volunteers, VAs were visualized well. In none of them, proton-density weighted spin-echo (SE) images were inferior to both T1- and T2-weighted SE images. In four of eight patients with Meniere's disease, VAs were not visualized due to obstruction of VA, although in all of ten non-Meniere's disease patients with hearing loss or vertigo, VAs were well visualized. Although further investigation is needed, MR imaging of VA including both its content and surrounding bony structure would give important information to manage the patients with either Meniere's disease or other disorders of internal ears. (author)

  12. 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.

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

    Science.gov (United States)

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

    2013-07-01

    Ocular vestibular evoked myogenic potentials (oVEMPs) to binaural air-conducted stimulation (ACS) may provide a convenient way of assessing the crossed vestibulo-ocular reflex in patients with vestibular dysfunction as well as in healthy subjects. To investigate the clinical feasibility of using oVEMPs in response to binaural ACS to assess normal subjects and patients with vestibular dysfunction. The study investigated 24 normal subjects (14 men and 10 women, aged from 23 to 60 years) and 14 patients with unilateral peripheral vestibular dysfunction. Each subject underwent oVEMP testing in response to monaural ACS and binaural ACS (500 Hz tone burst, 135 dBSPL). In normal subjects, bilateral oVEMPs were elicited in 75% of subjects in response to monaural ACS and in 91% in response to binaural ACS. Asymmetry ratios (ARs) of the responses to binaural ACS were significantly smaller than those of the responses to monaural ACS (p binaural ACS. Approximately 30% of patients showed reduced ARs to binaural ACS relative to monaural ACS, primarily due to contamination by uncrossed responses elicited in healthy ears.

  14. 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.

  15. 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

  16. 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

  17. 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

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

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

    Directory of Open Access Journals (Sweden)

    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.

  19. 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...

  20. 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.

  1. 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...

  2. 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.

  3. 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.

  4. Tai Chi and vestibular rehabilitation improve vestibulopathic gait via different neuromuscular mechanisms: Preliminary report

    Directory of Open Access Journals (Sweden)

    Parker Stephen W

    2005-02-01

    gait and reduced excessive hip compensation. The VR group's improvements, however, were not the result of lower extremity neuromuscular pattern changes. Lower-extremity MEE increases corresponded to attenuated forward trunk linear and angular movement in the VR group, suggesting better control of upper body motion to minimize loss of balance. These data support a growing body of evidence that Tai Chi may be a valuable complementary treatment for vestibular disorders.

  5. A rare case of vestibular sinus tract: A periodontist enigma

    Directory of Open Access Journals (Sweden)

    Disha Nagpal

    2016-01-01

    Full Text Available Sinus tract occurs commonly in teeth with periapical/periodontal infection but the formation of a vestibular opening, causing esthetic compromise and food lodgement, is uncommon. Definitive treatment of a chronic sinus tract requires treatment of the original problem, that is, the necrotic pulp treated by endodontic therapy or by extraction of the tooth. However, at times endodontic therapy may not be adequate necessitating periodontal intervention. The present case had vestibular opening communicating with root canal of concerned tooth appearing ten years after trauma. The diagnosis of such cases can only be made after careful evaluation and the treatment plan has to be modified from the conventional. The success of such cases depends on the regular follow up as presented here and careful observation after each phase of treatment.

  6. 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.

  7. 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

  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. 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.

  10. Potencial evocado miogênico vestibular ocular: revisão de literatura

    OpenAIRE

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

    2016-01-01

    RESUMO Objetivo Identificar e sistematizar os principais estudos sobre o potencial evocado miogênico vestibular ocular e suas aplicações no diagnóstico das diversas doenças vestibulares. Estratégia de pesquisa Foram localizados artigos que descrevem a utilização do potencial evocado miogênico vestibular ocular na avaliação de doenças vestibulares nas bases PubMed, Web of Science, MEDLINE, Scopus, LILACS e SciELO. Critérios de seleção Foram incluídos estudos originais, com resumo disponí...

  11. 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.

  12. Galvanic Vestibular Stimulation in Hemi-Spatial Neglect

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    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.

  13. Comparative anatomy of the vestibular nuclear complex in submammalian vertebrates.

    Science.gov (United States)

    Mehler, W. R.

    1972-01-01

    A synopsis of the literature on the natural history of the vestibular nuclear complex (VNC) in lower vertebrates is presented in an attempt to assess the knowledge available. The review discloses that there is considerable descriptive information that is widely dispersed in the literature. However, information about the topology, number, and cellular composition of the cell groups that compose the VNC is sketchy. Major cytological and hodological information is still needed to establish which parts of the VNC actually are homologous.

  14. 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...

  15. Radiation Therapy and Hearing Loss

    International Nuclear Information System (INIS)

    Bhandare, Niranjan; Jackson, Andrew; Eisbruch, Avraham; Pan, Charlie C.; Flickinger, John C.; Antonelli, Patrick; Mendenhall, William M.

    2010-01-01

    A review of literature on the development of sensorineural hearing loss after high-dose radiation therapy for head-and-neck tumors and stereotactic radiosurgery or fractionated stereotactic radiotherapy for the treatment of vestibular schwannoma is presented. Because of the small volume of the cochlea a dose-volume analysis is not feasible. Instead, the current literature on the effect of the mean dose received by the cochlea and other treatment- and patient-related factors on outcome are evaluated. Based on the data, a specific threshold dose to cochlea for sensorineural hearing loss cannot be determined; therefore, dose-prescription limits are suggested. A standard for evaluating radiation therapy-associated ototoxicity as well as a detailed approach for scoring toxicity is presented.

  16. 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.

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

    Science.gov (United States)

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

    2014-01-01

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

  18. 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.

  19. 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

  20. Contribution of intracranial vertebral artery asymmetry to vestibular neuropathy.

    Science.gov (United States)

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

    2011-07-01

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

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

    Science.gov (United States)

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

    2013-09-01

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

  2. 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.

  3. 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.

  4. 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.

  5. Eliciting Cervical Vestibular-Evoked Myogenic Potentials by Bone-Conducted Vibration via Various Tapping Sites.

    Science.gov (United States)

    Tseng, Chia-Chen; Young, Yi-Ho

    2016-01-01

    This study compared bone-conducted vibration (BCV) cervical vestibular-evoked myogenic potentials (cVEMPs) via tapping at various skull sites in healthy subjects and patients with vestibular migraine (VM) to optimize stimulation conditions. Twenty healthy subjects underwent a series of cVEMP tests by BCV tapping via a minishaker at the Fz (forehead), Cz (vertex), and inion (occiput) sites in a randomized order of tapping sites. Another 20 VM patients were also enrolled in this study for comparison. All 20 healthy subjects had clear BCV cVEMPs when tapping at the inion (100%) or Cz (100%), but not at the Fz (75%). Mean p13 and n23 latencies from the Cz tapping were significantly longer than those from the Fz tapping, but not longer than those from the inion tapping. Unlike healthy subjects, tapping at the Cz (95%) elicited a significantly higher response rate of present cVEMPs than tapping at the inion (78%) in 20 VM patients (40 ears), because seven of nine VM ears with absent cVEMPs by inion tapping turned out to be present cVEMPs by Cz tapping. While both inion and Cz tapping elicited 100% response rate of cVEMPs for healthy individuals, Cz tapping had a higher response rate of cVEMPs than inion tapping for the VM group. In cases of total loss of saccular function, cVEMPs could not be activated by either inion or Cz tapping. However, if residual saccular function remains, Cz tapping may activate saccular afferents more efficiently than inion tapping.

  6. Pre-adaptation to noisy Galvanic vestibular stimulation is associated with enhanced sensorimotor performance in novel vestibular environments

    Directory of Open Access Journals (Sweden)

    Steven T Moore

    2015-06-01

    Full Text Available Performance on a visuomotor task in the presence of novel vestibular stimulation was assessed in nine healthy subjects. Four subjects had previously been adapted to 120 minutes exposure to noisy Galvanic vestibular stimulation (GVS over 12 weekly sessions of 10 minutes; the remaining five subjects had never experienced GVS. Subjects were seated in a flight simulator and asked to null the roll motion of a visual bar presented on a screen using a joystick. Both the visual bar and the simulator cabin were moving in roll with a pseudorandom (sum of sines waveform that were uncorrelated. The cross correlation coefficient, which ranges from 1 (identical waveforms to 0 (unrelated waveforms, was calculated for the ideal (perfect nulling of bar motion and actual joystick input waveform for each subject. The cross correlation coefficient for the GVS-adapted group (0.90 [SD 0.04] was significantly higher (t[8]=3.162; p=0.013 than the control group (0.82 [SD 0.04], suggesting that prior adaptation to GVS was associated with an enhanced ability to perform the visuomotor task in the presence of novel vestibular noise.

  7. 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

  8. 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

  9. 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.

  10. 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

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

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    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.

  12. Rapid limb-specific modulation of vestibular contributions to ankle muscle activity during locomotion

    NARCIS (Netherlands)

    Forbes, Patrick A.; Vlutters, Mark; Dakin, Christopher J.; van der Kooij, Herman; Blouin, Jean Sébastien; Schouten, Alfred C.

    2017-01-01

    Key points: -The vestibular influence on human walking is phase-dependent and modulated across both limbs with changes in locomotor velocity and cadence. -Using a split-belt treadmill, we show that vestibular influence on locomotor activity is modulated independently in each limb. -The independent

  13. 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.

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

    Science.gov (United States)

    Akdal, Gülden; Ozge, Aynur; Ergör, Gül

    2013-01-01

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

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

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    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.

  16. Impaired mental rotation in benign paroxysmal positional vertigo and acute vestibular neuritis.

    Directory of Open Access Journals (Sweden)

    Matteo eCandidi

    2013-11-01

    Full Text Available Vestibular processing is fundamental to our sense of orientation in space which is a core aspect of the representation of the self. Vestibular information is processed in a large subcortical-cortical neural network. Tasks requiring mental rotations of human bodies in space are known to activate neural regions within this network suggesting that vestibular processing is involved in the control of mental rotation. We studied whether mental rotation is impaired in patients suffering from two different forms of unilateral vestibular disorders (Vestibular Neuritis – VN- and Benign Paroxysmal positional Vertigo – BPPV with respect to healthy matched controls (C. We used two mental rotation tasks in which participants were required to: i mentally rotate their own body in space (egocentric rotation thus using vestibular processing to a large extent and ii mentally rotate human figures (allocentric rotation thus using own body representations to a smaller degree. Reaction times and accuracy of responses showed that VN and BPPV patients were impaired in both tasks with respect to C. Significantly, the pattern of results was similar in the three groups suggesting that patients were actually performing the mental rotation without using a different strategy from the control individuals. These results show that dysfunctional vestibular inflow impairs mental rotation of both own body and human figures suggesting that unilateral acute disorders of the peripheral vestibular input massively affect the cerebral processes underlying mental rotations.

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

    Science.gov (United States)

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

    1998-07-01

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

  18. Hearing loss

    Science.gov (United States)

    Decreased hearing; Deafness; Loss of hearing; Conductive hearing loss; Sensorineural hearing loss; Presbycusis ... Symptoms of hearing loss may include: Certain sounds seeming too loud Difficulty following conversations when two or more people are talking ...

  19. Repair of nostril stenosis using a triple flap combination: boomerang, nasolabial, and vestibular rotation flaps.

    Science.gov (United States)

    Bozkurt, Mehmet; Kapi, Emin; Kuvat, Samet Vasfi; Selçuk, Caferi Tayyar

    2012-11-01

    Tissue losses within the nose due to various reasons result in the loss of normal anatomy and function. The external nasal valve area is one of the most important functional components of the nose. The columella, lobule, nostril, and alar region are among the components forming the external nasal valve area. Deformities of the nostrils are among the most frequently observed features that interfere with the functional anatomy of the nose. Malformations of the nostrils often emerge subsequent to cleft lip repairs. Stenoses are a common type of pathology among nostril deformities. In cases where a stenosis has formed, breathing problems and developmental anomalies may occur. In the patient with nostril stenosis presented in this report, there was a serious alar collapse and contracture subsequent to a cleft lip repair. In order to repair the nostril stenosis, a "boomerang flap" was chosen. This boomerang flap was used in combination with a nasolabial flap, a vestibular rotation flap, and a conchal cartilage graft to achieve a satisfactory repair.

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

    Directory of Open Access Journals (Sweden)

    Elisa Raffaella Ferrè

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

  1. Extremely discrepant mutation spectrum of SLC26A4 between Chinese patients with isolated Mondini deformity and enlarged vestibular aqueduct

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    Yan Xiaofei

    2011-09-01

    Full Text Available Abstract Background Mutations in SLC26A4 cause Pendred syndrome (hearing loss with goiter or DFNB4 (non-syndromic hearing loss with inner ear malformation, such as enlarged vestibular aqueduct or Mondini deformity. The relationship between mutations in SLC26A4 and Mondini deformity without enlarged vestibular aqueduct has not been studied in any Chinese deaf population. The purpose of this study was to assess whether mutations in the SLC26A4 gene cause Mondini deformity without an enlarged vestibular aqueduct (isolated Mondini deformity in a Chinese population. Methods In total, 144 patients with sensorineural hearing loss were included and subjected to high-resolution temporal bone CT. Among them, 28 patients with isolated Mondini dysplasia (MD group, 50 patients with enlarged vestibular aqueduct with Mondini dysplasia (EVA with MD group, 50 patients with enlarged vestibular aqueduct without Mondini dysplasia (EVA group, and 16 patients with other types of inner ear malformations (IEM group were identified. The coding exons of SLC26A4 were analyzed in all subjects. Results DNA sequence analysis of SLC26A4 was performed in all 144 patients. In the different groups, the detection rate of the SLC26A4 mutation differed. In the isolated MD group, only one single allelic mutation in SLC26A4 was found in one patient (1/28, 3.6%. In the EVA with MD group, biallelic and monoallelic SLC26A4 mutations were identified in 46 patients (46/50, 92.0% and three patients (3/50, 6.0%, respectively. Also, in the EVA group, biallelic and monoallelic SLC26A4 mutations were identified in 46 patients (46/50, 92.0% and three patients (3/50, 6.0%, respectively. These percentages were identical to those in the EVA plus MD group. Only two patients carried monoallelic mutations of the SLC26A4 gene in the IEM group (2/16, 12.5%. There were significant differences in the frequency of SLC26A4 mutation among the groups (P SLC26A4 mutation in the isolated MD group was

  2. 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.

  3. 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.

  4. 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.

  5. 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.

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

    Science.gov (United States)

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

    1998-01-01

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

  7. 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.

  8. [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.

  9. Gd enhanced MRI in sensorineural hearing loss

    International Nuclear Information System (INIS)

    Takenaka, Mika; Tono, Tetsuya; Toyama, Katsuhiro; Kano, Kiyo; Morimitsu, Tamotsu

    1996-01-01

    The enhanced MRI hearing findings of the inner ear in 124 patients with sensorineural hearing loss were evaluated. MR images were obtained before and after the intravenous administration of gadolinium (0.1 mmol/kg). In three out of seventy-nine patients with unilateral healing loss, cochlear and/or the vestibular enhancement was noted on the symptomatic side. The positive cases included those with Ramsay-Hunt syndrome, mumps and so-called sudden deafness. Forty-five patients with bilateral hearing loss showed no enhancement within the inner ear. Although positive gadolinium enhancement of the inner ear may detect inflammatory lesions due to a viral infection, its incidence in sensorineural hearing loss, including cases of sudden deafness. seems to be extremely rare. (author)

  10. Coding of Velocity Storage in the Vestibular Nuclei

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    Sergei B. Yakushin

    2017-08-01

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

  11. Sociodemographic factors and vestibular schwannoma: a Danish nationwide cohort study

    DEFF Research Database (Denmark)

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

    2010-01-01

    Vestibular schwannoma (VS) (or acoustic neuroma) accounts for about 5%-6% of all intracranial tumors; little is known about the etiology. We investigated the association between various sociodemographic indicators and VS in a cohort of 3.26 million Danish residents, with 1087 cases identified in 35...... 308 974 person-years under risk, with data accrued from 1993 to 2006. Complete ascertainment of cases was ensured by using population-based and clinical cancer registries. Information on sociodemographic indicators was obtained on an annually updated individual level from Statistics Denmark. Log...

  12. 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)

  13. Usher syndrome: Hearing loss, retinal degeneration and associated abnormalities

    OpenAIRE

    Mathur, Pranav; Yang, Jun

    2015-01-01

    Usher syndrome (USH), clinically and genetically heterogeneous, is the leading genetic cause of combined hearing and vision loss. USH is classified into three types, based on the hearing and vestibular symptoms observed in patients. Sixteen loci have been reported to be involved in the occurrence of USH and atypical USH. Among them, twelve have been identified as causative genes and one as a modifier gene. Studies on the proteins encoded by these USH genes suggest that USH proteins interact a...

  14. Vestibular syndrome in giant anteater (Myrmecophaga tridactyla / Síndrome vestibular em tamanduá-bandeira (Myrmecophaga tridactyla

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    Leandro Luís Martins

    2009-10-01

    Full Text Available The vestibular syndrome is a well-defined disease in domestic animals but little known in wild ones. Here this affection of central origin is described in a caquetic adult female giant anteater (Myrmecophaga tridactyla, which presented circling behavior, extensor hypermetry in thoracic limbs, head tilt and spontaneous horizontal and positional vertical nystagmus. The animal received tube feeding twice daily and dexamethasone was given subcutaneous once daily at the dosis of 6mg/kg, with a progressive improvement of health after the second day of treatment. Dose was reduced to a half from fourth to sixth day, and to a quarter on seventh day, when the animal died. On the fifth day, however, circle deambulation had ceased and hypermetry, head tilt and nystagmus were reduced. Treating vestibular syndrome is a challenge in wild animal practice. Treatment is affected by hyporexia and anorexia, making difficult the animals´ health improvement, which generally present muscle atrophy.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 dose 6mg/kg, 1x/dia, com melhora progressiva a partir da segunda administração. A dose foi diminuída pela metade do quarto ao sexto dia, e reduzida novamente à metade no sétimo dia, quando ocorreu óbito. Entretanto, no quinto dia de tratamento, a deambulação em círculos foi interrompida, e a hipermetria, desvio da cabeça e nistagmo diminuídos. O tratamento de animais selvagens com síndrome vestibular é um desafio e é prejudicado pela hiporexia ou anorexia

  15. 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.

  16. 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.

  17. Tandem walking as a quick screening test for vestibular disorders.

    Science.gov (United States)

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

    2017-12-11

    Although many screening tests of balance are available, few of them have been well validated for clinical or research uses. The goal of this study was to test an updated version of an old test, Tandem Walking, to determine how useful it is for screening patients with vestibular disorders. Case-control study. Subjects were 90 adult patients with vestibular disorders and 292 healthy adult controls. They were tested on the number of correct tandem steps they could perform with arms crossed and eyes closed in a series of 10 steps. Correct steps could be nonconsecutive. Subjects were given one practice trial with eyes open and three experimental trials with eyes closed. Receiver operating characteristic (ROC), and sensitivity and specificity were calculated. ROC values, sensitivity, and specificity were, at best, only moderate, no matter how the age range was cut. Even for subjects in the age group with the highest ROC value (i.e., age less than 50 years), ROC = 0.8, sensitivity = 0.77, and specificity = 0.72. These results indicate that 23% of patients will not be identified. Therefore, we recommend that if this test is used for screening patients in the clinic or healthy volunteers, the result should be interpreted with care. 3b Laryngoscope, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  18. Prevalence of hydrocephalus in 157 patients with vestibular schwannoma

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    Rogg, Jeffrey M.; Ahn, S.H.; Tung, G.A. [Rhode Island Hospital, Department of Diagnostic Imaging, Providence, Rhode Island (United States); Reinert, S.E. [Rhode Island Hospital, Lifespan Medical Computing, Providence, Rhode Island (United States); Noren, G. [Rhode Island Hospital, Department of Neurosurgery, Providence, Rhode Island (United States)

    2005-05-01

    The purpose of this study was to determine the prevalence of hydrocephalus in patients with vestibular schwannoma. A second objective was to investigate possible etiologies for hydrocephalus in this population by attempting to correlate the incidence and severity of hydrocephalus with tumor volume and extent of fourth ventricular compression. The MRI examinations of 157 adult patients with vestibular schwannoma were retrospectively reviewed. Tumor size was quantified, and the presence of accompanying hydrocephalus was assessed, categorized as communicating type or non-communicating type and then rated as mild, moderate or severe (grades 1-3). Next, the degree of fourth ventricular distortion caused by tumor mass effect was evaluated and categorized as mild, moderate or severe (grades 1-3). Spearman's rank correlation coefficient was used to test the relationships between tumor volume and (1) the extent of fourth ventricular effacement and (2) severity of hydrocephalus. Hydrocephalus was present in 28/157 (18%) cases and was categorized as mild in 11/28 (39%), moderate in 15/28 (54%) and severe in 2/28 (7%). Communicating-type hydrocephalus was present in 17/28 (61%) and non-communicating type in 11/28 (39%). There was a positive correlation between the grade of non-communicating hydrocephalus and tumor volume (r=0.38; P<0.001) and between the severity of fourth ventricular compression and extent of hydrocephalus in this group(r=0.43; P<0.001). (orig.)

  19. Evidence of a gustatory-vestibular pathway for protein transport.

    Science.gov (United States)

    Gacek, Richard; Lyon, Michael J

    2010-02-01

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

  20. 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

  1. Early diagnosis of acoustic neuroma by the vestibular test

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    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.

  2. An evidence-based case of acoustic/vestibular schwannoma

    Directory of Open Access Journals (Sweden)

    Girish Gupta

    2015-01-01

    Full Text Available A vestibular schwannoma, often called an acoustic neuroma/schwannoma, is a benign primary intracranial tumor of the myelin-forming cells of the vestibulo-cochlear nerve (8 th cranial nerve. This tumor arises from the Schwann cells responsible for the myelin sheath that helps keep peripheral nerves insulated. [1] Approximately, 3000 cases are diagnosed each year in the United States with a prevalence of about 1 in 100,000 worldwide. It comprises 5-10% of all intracranial neoplasms in adults. Incidence peaks in the fifth and sixth decades and both sexes are affected equally. Studies in Denmark published in 2004 show the incidence of 17.4/million. Most acoustic neuromas are diagnosed in patients between the ages of 30 and 60, and men and women appear to be affected equally. [2] The case illustrated here is a rare one of acoustic/vestibular schwannoma a surgical conditions, treated with Lycopodium, which produced improvement on both subjective and objective parameters.

  3. Preoperative predictive factors for hearing preservation in vestibular schwannoma surgery.

    Science.gov (United States)

    Rohit; Piccirillo, Enrico; Jain, Yogesh; Augurio, Angela; Sanna, Mario

    2006-01-01

    We performed a retrospective chart review to evaluate the various predictive factors for postoperative hearing preservation in the surgical management of vestibular schwannoma. Of 792 patients operated on for vestibular schwannoma between April 1987 and July 2002, 107 were candidates for hearing preservation surgery. These patients were divided into group 1 (hearing preserved) and group 2 (hearing not preserved), and both of these groups were evaluated for age, sex, pure tone average, sound discrimination score, tumor size, and auditory brain stem response parameters. A corrected chi2 test and a corrected t-test were used for statistical analysis. Multiple regression analysis was further done to evaluate independent predictive factors, either alone or in combination. The results were evaluated by use of the modified Sanna classification and the guidelines of the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS). Preoperative pure tone average and tumor size were the 2 predictive factors in our study. A Pearson correlation test showed that there was no multicollinearity between the factors. On multiple regression analysis by backward elimination of nonsignificant factors, we found that tumor size is an independent predictive factor for postoperative hearing. According to the modified Sanna classification, postoperative hearing was preserved in 11.2% of patients (equivalent to class A of AAO-HNS guidelines). In our series, preoperative pure tone average and tumor size were found to be predictors of postoperative hearing levels.

  4. 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.

  5. Hearing impairment caused by mutations in two different genes responsible for nonsyndromic and syndromic hearing loss within a single family.

    Science.gov (United States)

    Niepokój, Katarzyna; Rygiel, Agnieszka M; Jurczak, Piotr; Kujko, Aleksandra A; Śniegórska, Dominika; Sawicka, Justyna; Grabarczyk, Alicja; Bal, Jerzy; Wertheim-Tysarowska, Katarzyna

    2018-02-01

    Usher syndrome is rare genetic disorder impairing two human senses, hearing and vision, with the characteristic late onset of vision loss. This syndrome is divided into three types. In all cases, the vision loss is postlingual, while loss of hearing is usually prelingual. The vestibular functions may also be disturbed in Usher type 1 and sometimes in type 3. Vestibular areflexia is helpful in making a proper diagnosis of the syndrome, but, often, the syndrome is misdiagnosed as a nonsyndromic hearing loss. Here, we present a Polish family with hearing loss, which was clinically classified as nonsyndromic. After excluding mutations in the DFNB1 locus, we implemented the next-generation sequencing method and revealed that hearing loss was syndromic and mutations in the USH2A gene indicate Usher syndrome. This research highlights the importance of molecular analysis in establishing a clinical diagnosis of congenital hearing loss.

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

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    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.

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

    Science.gov (United States)

    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.

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

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    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.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. Pregnancy Loss

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    ... To receive Pregnancy email updates Enter email Submit Pregnancy loss Pregnancy loss is a harsh reality faced ... have successful pregnancies. Expand all | Collapse all Why pregnancy loss happens As many as 10 to 15 ...

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

    Science.gov (United States)

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

    2017-12-01

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

  16. 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.

  17. How does high-frequency sound or vibration activate vestibular receptors?

    Science.gov (United States)

    Curthoys, I S; Grant, J W

    2015-03-01

    The mechanism by which vestibular neural phase locking occurs and how it relates to classical otolith mechanics is unclear. Here, we put forward the hypothesis that sound and vibration both cause fluid pressure waves in the inner ear and that it is these pressure waves which displace the hair bundles on vestibular receptor hair cells and result in activation of type I receptor hair cells and phase locking of the action potentials in the irregular vestibular afferents, which synapse on type I receptors. This idea has been suggested since the early neural recordings and recent results give it greater credibility.

  18. 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

    Full Text Available Os sistemas de telecomunicações emitem radiofreqüência, uma radiação eletromagnética invisível. Telefones celulares transmitem microondas (450900 MHz no sistema analógico e 1,82,2 GHz no sistema digital, muito próximo à orelha do usuário. Esta energia é absorvida pela pele, orelha interna, nervo vestibulococlear e superfície do lobo temporal. OBJETIVO: Revisar a literatura sobre influência dos telefones celulares na audição e equilíbrio. FORMA DE ESTUDO: Revisão sistemática. METODOLOGIA: Foram pesquisados artigos nas bases Lilacs e Medline sobre a influência dos telefones celulares nos sistemas auditivo e vestibular, publicados de 2000 a 2005, e também materiais veiculados na Internet. RESULTADOS: Os estudos sobre radiação do telefone celular e risco de neurinoma do acústico apresentam resultados contraditórios. Alguns autores não encontram maior probabilidade de aparecimento do tumor nos usuários de celulares, enquanto outros relatam que a utilização de telefones analógicos por 10 anos ou mais aumenta o risco para o tumor. A exposição aguda às microondas emitidas pelo celular não influencia a atividade das células ciliadas externas da cóclea, in vivo e in vitro, a condução elétrica no nervo coclear, nem a fisiologia do sistema vestibular em humanos. As próteses auditivas analógicas são mais suscetíveis à interferência eletromagnética dos telefones celulares digitais. CONCLUSÃO: Não há comprovação de lesão cocleovestibular pelos telefones celulares.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 user’s ear. The skin, inner ear, cochlear nerve and the temporal lobe surface absorb the radiofrequency energy. AIM: literature review on the influence of cellular phones on hearing and balance. STUDY DESIGN: systematic

  19. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young-Hoon [Department of Neurosurgery, Seoul National University Bundang Hospital, Seongnam-si (Korea, Republic of); Department of Neurosurgery, Seoul National University College of Medicine, Seoul (Korea, Republic of); Kim, Dong Gyu, E-mail: gknife@plaza.snu.ac.kr [Department of Neurosurgery, Seoul National University Hospital, Seoul (Korea, Republic of); Department of Neurosurgery, Seoul National University College of Medicine, Seoul (Korea, Republic of); Han, Jung Ho [Department of Neurosurgery, Seoul National University Bundang Hospital, Seongnam-si (Korea, Republic of); Department of Neurosurgery, Seoul National University College of Medicine, Seoul (Korea, Republic of); Chung, Hyun-Tai; Kim, In Kyung; Song, Sang Woo [Department of Neurosurgery, Seoul National University Hospital, Seoul (Korea, Republic of); Department of Neurosurgery, Seoul National University College of Medicine, Seoul (Korea, Republic of); Park, Jeong-Hoon [Department of Neurosurgery, Seoul National University Bundang Hospital, Seongnam-si (Korea, Republic of); Department of Neurosurgery, Seoul National University College of Medicine, Seoul (Korea, Republic of); Kim, Jin Wook; Kim, Yong Hwy; Park, Chul-Kee [Department of Neurosurgery, Seoul National University Hospital, Seoul (Korea, Republic of); Department of Neurosurgery, Seoul National University College of Medicine, Seoul (Korea, Republic of); Kim, Chae-Yong [Department of Neurosurgery, Seoul National University Bundang Hospital, Seongnam-si (Korea, Republic of); Department of Neurosurgery, Seoul National University College of Medicine, Seoul (Korea, Republic of); Paek, Sun Ha; Jung, Hee-Won [Department of Neurosurgery, Seoul National University Hospital, Seoul (Korea, Republic of); Department of Neurosurgery, Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2013-01-01

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

  1. Large vestibular schwannomas and hydrocephalus: Lessons learnt from a single centre experience

    Directory of Open Access Journals (Sweden)

    Prakash Nair

    2014-01-01

    Full Text Available Aim: The aim of the following study is to analyze the outcome following surgery in 169 patients with large vestibular schwannoma (VS and to evaluate hydrocephalus as a prognostic factor in patients of the VSs. Subjects and Methods: Retrospective analysis of all cases of VSs admitted to our tertiary neurosurgical center from January 2005 to December 2010 was performed. Comparison of patients who underwent pre-operative cerebrospinal fluid (CSF diversion and those who underwent primary surgery was carried out for post-operative complications and delayed hydrocephalus. Results: A total of 169 patients of VS were seen. The mean age at presentation was 39.03 years (12-72 years. The most common symptom was hearing loss seen in 161 (95.2% cases. Giant VS was seen in 130 (75.5% and hydrocephalus was present in 110 (63.9%. Pre-operative CSF diversion was done in 23 (13.1% patients; 8 (4.6% patients developed gradually symptomatic hydrocephalus following surgery and underwent ventriculoperitoneal shunt. Total surgical excision was done in 92.9% patients and subtotal excision was done in 7% patients. Conclusions: Hydrocephalus occurs in longstanding untreated cases of VS. Hydrocephalus causes no statistically significant increase in post-operative complications like CSF leak and post-operative hematoma. Patients with hydrocephalus presenting with acute symptoms of raised intracranial pressure benefit from CSF diversion. In most patients, tumor resection will restore patency of the CSF pathway and CSF diversion can be avoided.

  2. Three-dimensional Organotypic Cultures of Vestibular and Auditory Sensory Organs.

    Science.gov (United States)

    Gnedeva, Ksenia; Hudspeth, A J; Segil, Neil

    2018-06-01

    The sensory organs of the inner ear are challenging to study in mammals due to their inaccessibility to experimental manipulation and optical observation. Moreover, although existing culture techniques allow biochemical perturbations, these methods do not provide a means to study the effects of mechanical force and tissue stiffness during development of the inner ear sensory organs. Here we describe a method for three-dimensional organotypic culture of the intact murine utricle and cochlea that overcomes these limitations. The technique for adjustment of a three-dimensional matrix stiffness described here permits manipulation of the elastic force opposing tissue growth. This method can therefore be used to study the role of mechanical forces during inner ear development. Additionally, the cultures permit virus-mediated gene delivery, which can be used for gain- and loss-of-function experiments. This culture method preserves innate hair cells and supporting cells and serves as a potentially superior alternative to the traditional two-dimensional culture of vestibular and auditory sensory organs.

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

    International Nuclear Information System (INIS)

    Kim, Young-Hoon; Kim, Dong Gyu; Han, Jung Ho; Chung, Hyun-Tai; Kim, In Kyung; Song, Sang Woo; Park, Jeong-Hoon; Kim, Jin Wook; Kim, Yong Hwy; Park, Chul-Kee; Kim, Chae-Yong; Paek, Sun Ha; Jung, Hee-Won

    2013-01-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

  5. Comparison of contrast-enhanced T1-weighted and 3D constructive interference in steady state images for predicting outcome after hearing-preservation surgery for vestibular schwannoma

    Energy Technology Data Exchange (ETDEWEB)

    Kocaoglu, M.; Bulakbasi, N.; Ucoz, T.; Ustunsoz, B.; Tayfun, C.; Somuncu, I. [GATA Department of Radiology, 06018, Etlik, Ankara (Turkey); Pabuscu, Y. [Department of Radiology, Celal Bayar University, Manisa (Turkey)

    2003-07-01

    We compared contrast-enhanced T1-weighted and 3D constructive interference in steady state (CISS) sequences for demonstrating possible prognostic factors in hearing-preservation surgery for vestibular schwannoma. We studied 22 patients with vestibular schwannomas having hearing-preservation surgery. Postoperatively six (27%) had a facial palsy and eight (36%) had hearing loss. There was a significant correlation between the size of the tumour and facial palsy (r=-0.72). Both techniques adequately demonstrated all tumours. Involvement of the fundus of the internal auditory canal (IAC) and a small distance between the lateral border of the tumour and the fundus were correlated significantly with hearing loss (r=-0.81 and -0.75, respectively). The 3D-CISS sequence, by virtue of its high contrast resolution was superior to T1-weighted images (P<0.05) for detection of the fundal involvement. The direction of displacement of the facial nerve did not correlate with facial palsy or hearing loss. We think that 3D-CISS images better show the features influencing surgical outcome, but that contrast-enhanced T1-weighted images are required for diagnosis. (orig.)

  6. Comparison of contrast-enhanced T1-weighted and 3D constructive interference in steady state images for predicting outcome after hearing-preservation surgery for vestibular schwannoma

    International Nuclear Information System (INIS)

    Kocaoglu, M.; Bulakbasi, N.; Ucoz, T.; Ustunsoz, B.; Tayfun, C.; Somuncu, I.; Pabuscu, Y.

    2003-01-01

    We compared contrast-enhanced T1-weighted and 3D constructive interference in steady state (CISS) sequences for demonstrating possible prognostic factors in hearing-preservation surgery for vestibular schwannoma. We studied 22 patients with vestibular schwannomas having hearing-preservation surgery. Postoperatively six (27%) had a facial palsy and eight (36%) had hearing loss. There was a significant correlation between the size of the tumour and facial palsy (r=-0.72). Both techniques adequately demonstrated all tumours. Involvement of the fundus of the internal auditory canal (IAC) and a small distance between the lateral border of the tumour and the fundus were correlated significantly with hearing loss (r=-0.81 and -0.75, respectively). The 3D-CISS sequence, by virtue of its high contrast resolution was superior to T1-weighted images (P<0.05) for detection of the fundal involvement. The direction of displacement of the facial nerve did not correlate with facial palsy or hearing loss. We think that 3D-CISS images better show the features influencing surgical outcome, but that contrast-enhanced T1-weighted images are required for diagnosis. (orig.)

  7. 78 FR 53700 - Revised Medical Criteria for Evaluating Hearing Loss and Disturbances of Labyrinthine-Vestibular...

    Science.gov (United States)

    2013-08-30

    ... your comments to the Office of Regulations and Reports Clearance, Social Security Administration, 107... explanation? Are the requirements for otological examinations and audiometric testing provided in sections 2... medical reasons for a discrepancy between the speech reception threshold and the pure tone average? Could...

  8. Potencial evocado miogênico vestibular a baixas frequências de estimulação Vestibular evoked myogenic potentials using low frequency stimuli

    Directory of Open Access Journals (Sweden)

    Aline Cabral de Oliveira

    2011-12-01

    Full Text Available Os potenciais evocados miogênicos vestibulares são reflexos vestíbulo-cervicais, decorrentes da estimulação do sáculo com sons de forte intensidade. São necessários parâmetros de normalidade para indivíduos jovens normais, utilizando-se estímulos a baixas frequências, as quais configuram a região de maior sensibilidade desse órgão sensorial. OBJETIVO: Realizar normatização do potencial evocado miogênico vestibular para baixas frequências de estimulação. MATERIAL E MÉTODO: Captou-se o potencial evocado miogênico vestibular em 160 orelhas, no músculo esternocleidomastoideo, de forma ipsilateral, por meio da promediação de 200 tone bursts, frequência de 250 Hz, intensidade de 95 dB NAn. FORMA DE ESTUDO: Estudo de coorte contemporânea com corte transversal. RESULTADOS: Aplicando-se o teste T de Student ou o Teste de Mann-Whitney, não foi constatada diferença significativa para parâmetros do potencial evocado miogênico vestibular entre os gêneros, para p Vestibular evoked myogenic potentials are vestibulocervical reflexes resulting from sacculus stimulation with strong intensity sounds. Normality parameters are necessary for young normal individuals, using low frequency stimuli, which configure the most sensitive region of this sensory organ. AIM: To establish vestibular evoked myogenic potential standards for low frequency stimulation. MATERIAL AND METHOD: Vestibular evoked myogenic potential was captured from 160 ears, in the ipsilateral sternocleidomastoid muscle, using 200 averaged tone-burst stimuli, at 250 Hz, with an intensity of 95 dB NAn. CASE STUDY: Clinical observational cross-sectional. RESULTS: Neither the student's t-test nor the Mann-Whitney test showed a significant difference in latency or vestibular evoked myogenic potential amplitudes, for p <; 0.05. Irrespective of gender, we found latencies of p13-n23 and p13-n23 interpeaks of 13.84 ms (± 1.41, 23.81 ms (±1.99 and 10.62 ms (± 6.56, respectively

  9. Dosimetric and Clinical Analysis of Spatial Distribution of the Radiation Dose in Gamma Knife Radiosurgery for Vestibular Schwannoma

    International Nuclear Information System (INIS)

    Massager, Nicolas; Lonneville, Sarah; Delbrouck, Carine; Benmebarek, Nadir; Desmedt, Françoise; Devriendt, Daniel

    2011-01-01

    Objectives: We investigated variations in the distribution of radiation dose inside (dose inhomogeneity) and outside (dose falloff) the target volume during Gamma Knife (GK) irradiation of vestibular schwannoma (VS). We analyzed the relationship between some parameters of dose distribution and the clinical and radiological outcome of patients. Methods and Materials: Data from dose plans of 203 patients treated for a vestibular schwannoma by GK C using same prescription dose (12 Gy at the 50% isodose) were collected. Four different dosimetric indexes were defined and calculated retrospectively in all plannings on the basis of dose–volume histograms: Paddick conformity index (PI), gradient index (GI), homogeneity index (HI), and unit isocenter (UI). The different measures related to distribution of the radiation dose were compared with hearing and tumor outcome of 203 patients with clinical and radiological follow-up of minimum 2 years. Results: Mean, median, SD, and ranges of the four indexes of dose distribution analyzed were calculated; large variations were found between dose plans. We found a high correlation between the target volume and PI, GI, and UI. No significant association was found between the indexes of dose distribution calculated in this study and tumor control, tumor volume shrinkage, hearing worsening, loss of functional hearing, or complete hearing loss at last follow-up. Conclusions: Parameters of distribution of the radiation dose during GK radiosurgery for VS can be highly variable between dose plans. The tumor and hearing outcome of patients treated is not significantly related to these global indexes of dose distribution inside and around target volume. In GK radiosurgery for VS, the outcome seems more to be influenced by local radiation dose delivered to specific structures or volumes than by global dose gradients.

  10. Posturografia em idosos com distúrbios vestibulares e quedas

    Directory of Open Access Journals (Sweden)

    Camila Macedo

    2013-05-01

    Full Text Available Introdução: A posturografia estática e dinâmica tem sido usada para analisar a habilidade de idosos com disfunção vestibular em manter o equilíbrio corporal em diferentes condições de conflitos sensoriais. O objetivo do exame é quantificar a velocidade de oscilação e o deslocamento do centro de pressão nas condições de conflitos visual, somatossensorial e interação visuo-vestibular, e o limite de estabilidade. Objetivo: Analisar a literatura referente ao controle do equilíbrio corporal em idosos com distúrbios vestibulares por meio de posturografia computadorizada estática e dinâmica. Métodos: Revisão nas bases de dados LILACS, EMBASE, MEDLINE, Scielo, Cochrane, ISI Web of Knowledge e bibliotecas virtuais de teses e dissertações, utilizando as palavras-chave “Idoso”, “Equilíbrio Postural”, “Avaliação”, “Controle Postural”, “Quedas”, “Posturografia”, “Vestibular” e/ou “Tontura” de publicações dos últimos vinte anos. Resultados: Há vários modelos de posturografias que mensuram as respostas posturais e o risco de quedas em indivíduos idosos, perante os diferentes estímulos sensoriais, incluindo a tecnologia de realidade virtual. Os idosos com desequilíbrio corporal, tontura, e/ou com histórico de quedas apresentam pior desempenho que idosos sem queixas, sem histórico de quedas e indivíduos mais jovens. Conclusão: A posturografia é uma valiosa ferramenta para análise quantitativa do controle postural, permitindo a identificação das condições sensoriais nas quais os idosos vestibulopatas apresentam maior instabilidade.

  11. 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

  12. [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.

  13. 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.

  14. Beyond the Vestibulo-Ocular Reflex: Vestibular Input is Processed Centrally to Achieve Visual Stability

    Directory of Open Access Journals (Sweden)

    Edwin S. Dalmaijer

    2018-03-01

    Full Text Available The current study presents a re-analysis of data from Zink et al. (1998, Electroencephalography and Clinical Neurophysiology, 107, who administered galvanic vestibular stimulation through unipolar direct current. They placed electrodes on each mastoid and applied either right or left anodal stimulation. Ocular torsion and visual tilt were measured under different stimulation intensities. New modelling introduced here demonstrates that directly proportional linear models fit reasonably well with the relationship between vestibular input and visual tilt, but not to that between vestibular input and ocular torsion. Instead, an exponential model characterised by a decreasing slope and an asymptote fitted best. These results demonstrate that in the results presented by Zink et al. (1998, ocular torsion could not completely account for visual tilt. This suggests that vestibular input is processed centrally to stabilise vision when ocular torsion is insufficient. Potential mechanisms and seemingly conflicting literature are discussed.

  15. Galvanic Vestibular Stimulation (GVS) as an Analogue of Post-flight Sensorimotor Dysfunction

    Data.gov (United States)

    National Aeronautics and Space Administration — Aim 1A (complete): Tolerance to GVS. Dilda, V, MacDougall HG, Moore, ST. Tolerance to extended Galvanic vestibular stimulation: optimal exposure for astronaut...

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

    Science.gov (United States)

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

    2014-01-01

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

  17. Angiogenesis in vestibular schwannomas: expression of extracellular matrix factors MMP-2, MMP-9, and TIMP-1

    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...

  18. 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

  19. SENTIDOS DO LETRAMENTO: A ESCRITA NO EVENTO VESTIBULAR

    Directory of Open Access Journals (Sweden)

    Victoria Wilson da Costa Coelho

    2015-06-01

    Full Text Available The aim of this paper is to pose a reflection on explicit or underlying literacy practices in a literacy event such as the Brazilian university entrance exams (vestibular using, as an object of study, the essays written during that event. We aim to understand the educated writing culture, or Brazilian literacy, in its very extreme, that is, the end of High School, based on Bakhtin’s theory of enunciation. Despite pedagogical measures focused on elaborate (argumentative writing in view of college assessment exams and ENEM (National High School Exam, we know how unsatisfactory its results still are, in terms of the school literacy practices, which still remains to be sufficiently reflected on. It is also worth highlighting that we understand writing (school writing more as a set of social practices than as a set of skills alone.

  20. Motility of vestibular hair cells in the chick.

    Science.gov (United States)

    Ogata, Y; Sekitani, T

    1993-01-01

    Recent studies of the outer hair cells in cochlea have demonstrated active motilities. However, very little study has been done on the vestibular hair cells (VHCs). The present study shows the motile response of the VHCs induced by application of Ca2+/ATP promoting contraction. Reversible cell shape changes could be shown in 10 of 16 isolated type I hair cells and 9 of 15 isolated type II hair cells by applying the contraction solution. Furthermore, the sensory hair bundles in the utricular epithelium pivoted around the base and stood perpendicularly to the apical borderline of the epithelium in response to the application of the same solution. It is suggested that the contraction of the isolated VHCs may be transferred to tension which causes the sensory hair bundles to restrict their motion in normal tissue, instead of changing the cell shape.

  1. Probabilistic Tractography of the Cranial Nerves in Vestibular Schwannoma.

    Science.gov (United States)

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

    2017-11-01

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

  2. Influence of vestibular activation on respiration in humans

    Science.gov (United States)

    Monahan, Kevin D.; Sharpe, Melissa K.; Drury, Daniel; Ertl, Andrew C.; Ray, Chester A.

    2002-01-01

    The purpose of this study was to determine the effects of the semicircular canals and otolith organs on respiration in humans. On the basis of animal studies, we hypothesized that vestibular activation would elicit a vestibulorespiratory reflex. To test this hypothesis, respiratory measures, arterial blood pressure, and heart rate were measured during engagement of semicircular canals and/or otolith organs. Dynamic upright pitch and roll (15 cycles/min), which activate the otolith organs and semicircular canals, increased respiratory rate (Delta2 +/- 1 and Delta3 +/- 1 breaths/min, respectively; P < 0.05). Dynamic yaw and lateral pitch (15 cycles/min), which activate the semicircular canals, increased respiration similarly (Delta3 +/- 1 and Delta2 +/- 1, respectively; P < 0.05). Dynamic chair rotation (15 cycles/min), which mimics dynamic yaw but eliminates neck muscle afferent, increased respiration (Delta3 +/- 1; P < 0.05) comparable to dynamic yaw (15 cycles/min). Increases in respiratory rate were graded as greater responses occurred during upright (Delta5 +/- 2 breaths/min) and lateral pitch (Delta4 +/- 1) and roll (Delta5 +/- 1) performed at 30 cycles/min. Increases in breathing frequency resulted in increases in minute ventilation during most interventions. Static head-down rotation, which activates otolith organs, did not alter respiratory rate (Delta1 +/- 1 breaths/min). Collectively, these data indicate that semicircular canals, but not otolith organs or neck muscle afferents, mediate increased ventilation in humans and support the concept that vestibular activation alters respiration in humans.

  3. Use of Virtual Reality Tools for Vestibular Disorders Rehabilitation: A Comprehensive Analysis

    OpenAIRE

    Bergeron, Mathieu; Lortie, Catherine L.; Guitton, Matthieu J.

    2015-01-01

    Classical peripheral vestibular disorders rehabilitation is a long and costly process. While virtual reality settings have been repeatedly suggested to represent possible tools to help the rehabilitation process, no systematic study had been conducted so far. We systematically reviewed the current literature to analyze the published protocols documenting the use of virtual reality settings for peripheral vestibular disorders rehabilitation. There is an important diversity of settings and prot...

  4. 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.

  5. 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

  6. 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...

  7. Vestibular Balance Deficits Following Head Injury: Recommendations Concerning Evaluation and Rehabilitation in the Military Setting

    Science.gov (United States)

    2012-02-27

    audiogram, magnetic resonance imaging ( MRI ) scan, and a battery of neuro-vestibular tests, etc. (see appendix B). Many of the findings are detailed...bills108/s1217.html 19 E.g., driven by a laptop, tablet PC, or PDA.   42 The authors also considered testing needs immediately after referral (by the... MRI scan   72 Neuro-vestibular testing o Dynamic Computerized Postu rography o Rotat ional chair t est ing of gain, phase, and symmet ry o Step

  8. 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

  9. 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

  10. Augmented asymmetrical visual field dependence in asymptomatic diabetics: evidence of subclinical asymmetrical bilateral vestibular dysfunction.

    Science.gov (United States)

    Razzak, Rima Abdul; Bagust, Jeffery; Docherty, Sharon; Hussein, Wiam; Al-Otaibi, Abdullah

    2015-01-01

    Diabetes negatively affects the vestibular system in many ways, with vestibular dysfunction (VD), a co-morbidity with a high prevalence in diabetics. The ability to perceive subjective visual vertical (SVV), as a sign of vestibular dysfunction, and visual field dependence was measured using a computerized rod and frame test (CRAF). Alignment errors recorded from 47 asymptomatic Type II diabetics (no vertigo or falls, without peripheral neuropathy or retinopathy) were compared to 29 healthy age matched (46-69years) controls. Visual field dependence was significantly larger and more asymmetrical in the diabetics than controls. In the absence of any visual references, or when a vertical reference frame was provided, SVV perception was accurate in both groups, with no significant difference between the controls and diabetics. During tilted frame presentations, the proportion of subjects with either SVV deviations, or an asymmetry index, larger than an upper limit derived from the control data was significantly greater in diabetics than controls. These results suggest that the decreased ability to resolve visuo-vestibular conflict in asymptomatic diabetic patients (free of retinopathy and peripheral neuropathy) compared to controls may be related to diabetic complications affecting vestibular structures and thus causing a decompensation of subclinical vestibular asymmetries. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. 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.

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

    Science.gov (United States)

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

    2001-01-01

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

  13. 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...

  14. 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...

  15. 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

  16. 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

  17. 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

  18. KCNJ10 may not be a contributor to nonsyndromic enlargement of vestibular aqueduct (NSEVA in Chinese subjects.

    Directory of Open Access Journals (Sweden)

    Jiandong Zhao

    Full Text Available BACKGROUND: Nonsyndromic enlargement of vestibular aqueduct (NSEVA is an autosomal recessive hearing loss disorder that is associated with mutations in SLC26A4. However, not all patients with NSEVA carry biallelic mutations in SLC26A4. A recent study proposed that single mutations in both SLC26A4 and KCNJ10 lead to digenic NSEVA. We examined whether KCNJ10 excert a role in the pathogenesis of NSEVA in Chinese patients. METHODS: SLC26A4 was sequenced in 1056 Chinese patients with NSEVA. KCNJ10 was screened in 131 patients who lacked mutations in either one or both alleles of SLC26A4. Additionally, KCNJ10 was screened in 840 controls, including 563 patients diagnosed with NSEVA who carried biallelic SLC26A4 mutations, 48 patients with nonsyndromic hearing loss due to inner ear malformations that did not involve enlargement of the vestibular aqueduct (EVA, 96 patients with conductive hearing loss due to various causes, and 133 normal-hearing individuals with no family history of hereditary hearing loss. RESULTS: 925 NSEVA patients were found carrying two-allele pathogenic SLC26A4 mutations. The most frequently detected KCNJ10 mutation was c.812G>A (p.R271H. Compared with the normal-hearing control subjects, the occurrence rate of c.812G>A in NSEVA patients with lacking mutations in one or both alleles of SLC26A