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Sample records for vestibular neuronitis

  1. Vestibular Neuronitis

    Science.gov (United States)

    ... Purulent Labyrinthitis Ear Disorders Caused by Drugs Acoustic Neuroma Vestibular neuronitis is a disorder characterized by a ... Purulent Labyrinthitis Ear Disorders Caused by Drugs Acoustic Neuroma NOTE: This is the Consumer Version. CONSUMERS: Click ...

  2. Vestibular neuronitis. An otoneurological evaluation.

    Science.gov (United States)

    Silvoniemi, P

    1988-01-01

    Eighty-one cases with vestibular neuronitis were examined. The diagnostic criteria were a sudden onset of vertigo without previous symptoms, spontaneous nystagmus towards the healthy side, totally extinguished caloric responses with 44 degrees C and 30 degrees C water irrigation and no involvement of hearing associated with the onset of the disease. The series was divided into a prospective and a retrospective group. The prospective group A was examined at the acute stage, about 1 month and 1 year afterwards. The retrospective group B fulfilled the same criteria as group A and was examined 1-8 years after the acute stage. The results of the acute stage in group B were analysed from the case history reports, electronystagmo- and audiograms. The preceding and predisposing factors and symptoms were inquired. The examination scheme included the clinical otoneurological examination, the nystagmographic, audiological and clinical neurophysiological measurements and the serological and hematological specimens were collected at the acute stage of group A to examine the role of virus infections in the etiology of vestibular neuronitis. The liquor specimens of 16 cases available in group A were analysed. A recent respiratory infection was reported by 9 cases (27.3 percent) in group A and by 18 cases (37.5 percent) in group B. The serological evidence (increase of IgM-antibodies) was observed in 1 case against influenza A and in 1 case against parainfluenza 3 and the hematological examinations revealed clues of virus infection in 6 cases (18.2 percent) of group A. Cell counts and protein analyses of the liquor specimens were within normal limits. Cases with arterial hypertension under medical control were observed in 15.2 percent of group A and 14.6 percent in group B. These figures do not exceed the age- and sex-correlated prevalence of arterial hypertension in Finnish population. The clinical symptoms included an acute chiefly rotatory vertigo associated with nausea and vomiting without subjective involvement of hearing. The prominent symptoms lessened gradually during the first week and most of the patients were able to their earlier work after one month. The prognosis of the disease was good. The clinical otoneurological findings of the acute stage included spontaneous nystagmus with Frenzel's glasses and disturbances of the vestibulospinal tests. These abnormalities improved markedly during the follow-up period. The results of electronystagmography were characteristic of a pure peripheral vestibular disorder. Nystagmic beats were observed almost regularly in the pendular eye-tracking test at the acute stage examination.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:3068952

  3. Vestibular convergence patterns in vestibular nuclei neurons of alert primates

    Science.gov (United States)

    Dickman, J. David; Angelaki, Dora E.

    2002-01-01

    Sensory signal convergence is a fundamental and important aspect of brain function. Such convergence may often involve complex multidimensional interactions as those proposed for the processing of otolith and semicircular canal (SCC) information for the detection of translational head movements and the effective discrimination from physically congruent gravity signals. In the present study, we have examined the responses of primate rostral vestibular nuclei (VN) neurons that do not exhibit any eye movement-related activity using 0.5-Hz translational and three-dimensional (3D) rotational motion. Three distinct neural populations were identified. Approximately one-fourth of the cells exclusively encoded rotational movements (canal-only neurons) and were unresponsive to translation. The canal-only central neurons encoded head rotation in SCC coordinates, exhibited little orthogonal canal convergence, and were characterized with significantly higher sensitivities to rotation as compared to primary SCC afferents. Another fourth of the neurons modulated their firing rates during translation (otolith-only cells). During rotations, these neurons only responded when the axis of rotation was earth-horizontal and the head was changing orientation relative to gravity. The remaining one-half of VN neurons were sensitive to both rotations and translations (otolith + canal neurons). Unlike primary otolith afferents, however, central neurons often exhibited significant spatiotemporal (noncosine) tuning properties and a wide variety of response dynamics to translation. To characterize the pattern of SCC inputs to otolith + canal neurons, their rotational maximum sensitivity vectors were computed using exclusively responses during earth-vertical axis rotations (EVA). Maximum sensitivity vectors were distributed throughout the 3D space, suggesting strong convergence from multiple SCCs. These neurons were also tested with earth-horizontal axis rotations (EHA), which would activate both vertical canals and otolith organs. However, the recorded responses could not be predicted from a linear combination of EVA rotational and translational responses. In contrast, one-third of the neurons responded similarly during EVA and EHA rotations, although a significant response modulation was present during translation. Thus this subpopulation of otolith + canal cells, which included neurons with either high- or low-pass dynamics to translation, appear to selectively ignore the component of otolith-selective activation that is due to changes in the orientation of the head relative to gravity. Thus contrary to primary otolith afferents and otolith-only central neurons that respond equivalently to tilts relative to gravity and translational movements, approximately one-third of the otolith + canal cells seem to encode a true estimate of the translational component of the imposed passive head and body movement.

  4. Direction discrimination thresholds of vestibular and cerebellar nuclei neurons.

    Science.gov (United States)

    Liu, Sheng; Yakusheva, Tatyana; Deangelis, Gregory C; Angelaki, Dora E

    2010-01-13

    To understand the roles of the vestibular system in perceptual detection and discrimination of self-motion, it is critical to account for response variability in computing the sensitivity of vestibular neurons. Here we study responses of neurons with no eye movement sensitivity in the vestibular (VN) and rostral fastigial nuclei (FN) using high-frequency (2 Hz) oscillatory translational motion stimuli. The axis of translation (i.e., heading) varied slowly (1 degrees /s) in the horizontal plane as the animal was translated back and forth. Signal detection theory was used to compute the threshold sensitivity of VN/FN neurons for discriminating small variations in heading around all possible directions of translation. Across the population, minimum heading discrimination thresholds averaged 16.6 degrees +/- 1 degrees SE for FN neurons and 15.3 degrees +/- 2.2 degrees SE for VN neurons, severalfold larger than perceptual thresholds for heading discrimination. In line with previous studies and theoretical predictions, maximum discriminability was observed for directions where firing rate changed steeply as a function of heading, which occurs at headings approximately perpendicular to the maximum response direction. Forward/backward heading thresholds tended to be lower than lateral motion thresholds, and the ratio of lateral over forward heading thresholds averaged 2.2 +/- 6.1 (geometric mean +/- SD) for FN neurons and 1.1 +/- 4.4 for VN neurons. Our findings suggest that substantial pooling and/or selective decoding of vestibular signals from the vestibular and deep cerebellar nuclei may be important components of further processing. Such a characterization of neural sensitivity is critical for understanding how early stages of vestibular processing limit behavioral performance. PMID:20071508

  5. Glutamatergic vestibular neurons express Fos after vestibular stimulation and project to the NTS and the PBN in rats.

    Science.gov (United States)

    Cai, Yi-Ling; Ma, Wen-Ling; Li, Min; Guo, Jun-Sheng; Li, Yi-Qian; Wang, Li-Gang; Wang, Wei-Zhong

    2007-05-01

    In this study, retrograde tracing method combined with phosphate-activated glutaminase (PAG) and Fos immunofluorescence histochemistry was used to identify glutamatergic vestibular nucleus (VN) neurons receiving vestibular inputs and projecting to the nucleus of the solitary tract (NTS) and the parabrachial nucleus (PBN). Conscious animals were subjected to 120 min Ferris-wheel like rotation stimulation. Neuronal activation was assessed by Fos expression in the nucleus of VN neurons. After Fluoro-gold (FG) injection into the caudal NTS, approximately 48% FG-labeled VN neurons were immunoreactive for PAG, and about 14% PAG/FG double-labeled neurons co-existed with Fos. Following FG injection into the PBN, approximately 56% FG-labeled VN neurons were double-labeled with PAG, and about 12% of the PAG/FG double-labeled neurons also expressed Fos. Careful examination of the typology and distribution pattern of these PAG-immunoreactive neurons indicated that the vast majority of these neurons were glutamatergic rather than GABAergic. These results suggest that PAG-immunoreactive VN neurons might constitute excitatory glutamatergic VN-NTS and VN-PBN transmission pathways and these pathways might be involved in vestibulo-autonomic reflexes during vestibular stimulation. PMID:17412503

  6. The effects of bilateral vestibular loss on hippocampal volume, neuronal number and cell proliferation in rats

    OpenAIRE

    PaulSmith; MichaelStrupp

    2012-01-01

    Previous studies in humans have shown that bilateral loss of vestibular function is associated with a significant bilateral atrophy of the hippocampus, which correlated with the patients’ spatial memory deficits. More recently, patients who had recovered from unilateral vestibular neuritis have been reported to exhibit a significant atrophy of the left posterior hippocampus. Therefore, we investigated whether bilateral vestibular deafferentation (BVD) would result in a decrease in neuronal ...

  7. The Effects of Bilateral Vestibular Loss on Hippocampal Volume, Neuronal Number, and Cell Proliferation in Rats

    OpenAIRE

    Zheng, Yiwen; Balabhadrapatruni, Sangeeta; Baek, Jean Ha; Chung, Phoebe; Gliddon, Catherine; Zhang, Ming; Cynthia L. Darlington; Napper, Ruth; Strupp, Michael; Brandt, Thomas; Paul F. Smith

    2012-01-01

    Previous studies in humans have shown that bilateral loss of vestibular function is associated with a significant bilateral atrophy of the hippocampus, which correlated with the patients’ spatial memory deficits. More recently, patients who had recovered from unilateral vestibular neuritis have been reported to exhibit a significant atrophy of the left posterior hippocampus. Therefore, we investigated whether bilateral vestibular deafferentation (BVD) would result in a decrease in neuronal ...

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

    OpenAIRE

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

    2010-01-01

    Plasticity in neuronal responses is necessary for compensation following brain lesions and adaptation to new conditions and motor learning. In a previous study, we showed that compensatory changes in the vestibuloocular reflex (VOR) following unilateral vestibular loss were characterized by dynamic reweighting of inputs from vestibular and extravestibular modalities at the level of single neurons that constitute the first central stage of VOR signal processing. Here, we studied another class ...

  9. Physiological Characterization of Vestibular Efferent Brainstem Neurons Using a Transgenic Mouse Model

    OpenAIRE

    Leijon, Sara; Magnusson, Anna K.

    2014-01-01

    The functional role of efferent innervation of the vestibular end-organs in the inner ear remains elusive. This study provides the first physiological characterization of the cholinergic vestibular efferent (VE) neurons in the brainstem by utilizing a transgenic mouse model, expressing eGFP under a choline-acetyltransferase (ChAT)-locus spanning promoter in combination with targeted patch clamp recordings. The intrinsic electrical properties of the eGFP-positive VE neurons were compared to th...

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

    Science.gov (United States)

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

    2001-01-01

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

  11. Postnatal developmental changes in the responses of mouse primary vestibular neurons to externally applied galvanic currents.

    Science.gov (United States)

    Desmadryl, G

    1991-12-17

    The ontogenesis of vestibular primary neuron sensitivity to depolarisation produced by galvanic current stimulations was studied in mouse inner ear explants maintained in vitro. Cathodal galvanic stimulations, which elicit an increase of the discharge frequencies, are assumed to act on the spike initiation site by depolarizing the neuron. The responses of neurons to galvanic currents at various developmental stages were recorded. The pattern of responses reflected the sensitivities of the neurons to depolarization. At birth, about 75% of the vestibular neurons responded weakly to high intensity galvanic currents thus indicating that they were able to generate action potentials. However, the very low gain of the response to the stimulation revealed the immaturity of the neurons at the spike generation site. Between the day of birth and the ninth postnatal day, an increase in the gain of the responses was observed, indicating the enhancement of the sensitivity of the vestibular neurons to the galvanic currents. This increase in sensitivity was more pronounced from the fourth postnatal day. The response of the neurons to galvanic stimulation increased gradually during postnatal development without reaching a plateau at postnatal day 9 indicating that a further physiological maturation occurs after this stage. These results are consistent with the morphological maturation of the vestibular primary afferents and with previous studies showing that the physiological maturation parallels myelination of the afferent fibers. PMID:1786638

  12. Response of central vestibular neurons to horizontal linear acceleration in the rat.

    Science.gov (United States)

    Lannou, J; Cazin, L; Hamann, K F

    1980-05-01

    Responses of central vestibular neurons to horizontal sinusoidal translation (F:0.25Hz) were recorded in albino rat. 57.5% of vestibular neurons were responding to this stimulation by a modulation of their firing rate, the mean phase angle of the response, averaged from the whole population being 22 +/- 79 deg. lag, relative to the peak of contralateral acceleration. Dynamic characteristics of phase and gain were studied and appeared to be different from previous reports on primary afferents: the gain decreased or was flat with increasing acceleration at one frequency, and the phase lag which was flat in the same conditions increased with increasing frequency. A phase lead of some units has been observed at low frequency (0.1 Hz). Regarding the convergence between otolith and canal inputs on nuclear vestibular neurons, it was shown that the major pattern of convergence is between canal and otolith inputs of same polarity. PMID:6248837

  13. Plasticity of Scarpa’s ganglion neurons as a possible basis for functional restoration within vestibular endorgans

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    SophieGaboyard-Niay

    2012-06-01

    Full Text Available In a previous study (Brugeaud et al., 2007, we observed spontaneous restoration of the vestibular function in young adult rodents following excitotoxic injury of the neuronal network of vestibular endorgans. The functional restoration was supported by a repair of synaptic contacts between hair cells and primary vestibular neurons. This process was observed in 2/3 of the animals studied and occurred within five days following the synapse insult. To assess whether structural plasticity is a fundamental trait of altered vestibular endorgans and to decipher the cellular mechanisms that support such a repair process, we studied the neuronal regeneration and synaptogenesis in co-cultures of vestibular epithelia and Scarpa’s ganglion from young and adult rodents. We demonstrate that under specific culture conditions, primary vestibular neurons from young mice or rats exhibit robust ability to regenerate nervous processes. When co-cultured with vestibular epithelia, primary vestibular neurons were able to establish de novo contacts with hair cells. Under the present paradigm, these contacts displayed morphological features of immature synaptic contacts. This reparative capacity remained in older mice although to a lesser extent. Identifying the basic mechanisms underlying the repair process may provide a basis for novel therapeutic strategies to restore mature and functional vestibular synaptic contacts following damage or loss.

  14. Retrograde transport of [3H]-D-aspartate label by cochlear and vestibular efferent neurons

    International Nuclear Information System (INIS)

    [3H]-D-aspartic acid was injected into the inner ear of rats. After a six hour survival time, labeled cells were found at all locations known to contain efferent cochlear or vestibular neurons. Most labeled neurons were found in the ipsilateral lateral superior olivary nucleus (LSO), although both ventral nuclei of the trapezoid body (VTB), group E, and the caudal pontine reticular nucleus (CPR) just adjacent to the ascending limb of the facial nerve also contained labeled cells. Because not all efferent neurons in the rat could be previously shown to be cholinergic, aspartate and glutamate are efferent transmitter candidates

  15. The effects of bilateral vestibular loss on hippocampal volume, neuronal number and cell proliferation in rats

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    PaulSmith

    2012-02-01

    Full Text Available Previous studies in humans have shown that bilateral loss of vestibular function is associated with a significant bilateral atrophy of the hippocampus, which correlated with the patients’ spatial memory deficits. More recently, patients who had recovered from unilateral vestibular neuritis have been reported to exhibit a significant atrophy of the left posterior hippocampus. Therefore, we investigated whether bilateral vestibular deafferentation (BVD would result in a decrease in neuronal number or volume in the rat hippocampus, using stereological methods. At 16 months post-BVD, we found no significant differences in hippocampal neuronal number or volume compared to sham controls, despite the fact that these animals exhibited severe spatial memory deficits. By contrast, using bromodeoxyuridine (BrdU as a marker of cell proliferation, we found that the number of BrdU-labelled cells significantly increased in the dentate gyrus of the hippocampus between 48 h and 1 week following BVD. Although a substantial proportion of these cells survived for up to 1 month, the survival rate was significantly lower in BVD animals when compared with that in sham animals. These results suggest a dissociation between the effects of BVD on spatial memory and hippocampal structure in rats and humans, which cannot be explained by an injury-induced increase in cell proliferation.

  16. Reconsidering the role of neuronal intrinsic properties and neuromodulation in vestibular homeostasis

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    MathieuBeraneck

    2012-02-01

    Full Text Available The sensorimotor transformations performed by central vestibular neurons (2°VN constantly adapt as the animal faces conflicting sensory information or sustains injuries. In order to ensure the homeostasis of vestibular-related functions, neural changes could in part rely on the regulation of 2°VN intrinsic properties. Here, we review evidence which demonstrates modulation and plasticity of 2°VN intrinsic properties. We first present partition of rodents 2°VN into distinct subtypes, namely type A and type B. Then, we focus on the respective properties of each type and their putative roles in vestibular functions. The intrinsic properties of 2°VN can be swiftly modulated by a wealth of neuromodulators, to adapt rapidly, for example, to temporary changes of the ecophysiological surroundings. To illustrate how intrinsic excitability can rapidly be modified in physiological conditions and therefore be targeted in the clinic, we present the modulation of vestibular reflexes in relation to the neuromodulatory fluctuation of the sleep/wake cycle. On the other hand, intrinsic properties can also be slowly yet deeply modified in response to major perturbations as is the case following a unilateral labyrinthectomy (UL. We revisit the experimental evidence which demonstrate that drastic alterations of the 2°VN intrinsic properties occur following UL, however with a slow dynamic, more on par with the compensation of dynamic deficits than static ones. Data are interpreted in the framework of a distributed process which progress from the global, large scale coping mechanisms (e.g. changes in behavioural strategies to the local, small scale ones (e.g. changes in intrinsic properties. Within this framework, the compensation of dynamic deficits improves with time as deeper modifications are engraved within the finer parts of the vestibular-related networks. Finally, we propose perspectives and working hypotheses to pave the way for future research aiming at understanding the m

  17. Spatiotemporal processing of linear acceleration: primary afferent and central vestibular neuron responses

    Science.gov (United States)

    Angelaki, D. E.; Dickman, J. D.

    2000-01-01

    Spatiotemporal convergence and two-dimensional (2-D) neural tuning have been proposed as a major neural mechanism in the signal processing of linear acceleration. To examine this hypothesis, we studied the firing properties of primary otolith afferents and central otolith neurons that respond exclusively to horizontal linear accelerations of the head (0.16-10 Hz) in alert rhesus monkeys. Unlike primary afferents, the majority of central otolith neurons exhibited 2-D spatial tuning to linear acceleration. As a result, central otolith dynamics vary as a function of movement direction. During movement along the maximum sensitivity direction, the dynamics of all central otolith neurons differed significantly from those observed for the primary afferent population. Specifically at low frequencies (neurons peaked in phase with linear velocity, in contrast to primary afferents that peaked in phase with linear acceleration. At least three different groups of central response dynamics were described according to the properties observed for motion along the maximum sensitivity direction. "High-pass" neurons exhibited increasing gains and phase values as a function of frequency. "Flat" neurons were characterized by relatively flat gains and constant phase lags (approximately 20-55 degrees ). A few neurons ("low-pass") were characterized by decreasing gain and phase as a function of frequency. The response dynamics of central otolith neurons suggest that the approximately 90 degrees phase lags observed at low frequencies are not the result of a neural integration but rather the effect of nonminimum phase behavior, which could arise at least partly through spatiotemporal convergence. Neither afferent nor central otolith neurons discriminated between gravitational and inertial components of linear acceleration. Thus response sensitivity was indistinguishable during 0.5-Hz pitch oscillations and fore-aft movements. The fact that otolith-only central neurons with "high-pass" filter properties exhibit semicircular canal-like dynamics during head tilts might have important consequences for the conclusions of previous studies of sensory convergence and sensorimotor transformations in central vestibular neurons.

  18. Fos expression in neurons of the rat vestibulo-autonomic pathway activated by sinusoidal galvanic vestibular stimulation

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    GayRHolstein

    2012-02-01

    Full Text Available The vestibular system sends projections to brainstem autonomic nuclei that modulate heart rate and blood pressure in response to changes in head and body position with regard to gravity. Consistent with this, binaural sinusoidal galvanic vestibular stimulation (sGVS in humans causes vasoconstriction in the legs, while low frequency (0.02-0.04 Hz sGVS causes a rapid drop in heart rate and blood pressure in anesthetized rats. We have hypothesized that these responses occur through activation of vestibulo-sympathetic pathways. In the present study, c-Fos protein expression was examined in neurons of the vestibular nuclei and rostral ventrolateral medullary region (RVLM that were activated by low frequency sGVS. We found c-Fos-labeled neurons in the spinal, medial and superior vestibular nuclei (SpVN, MVN and SVN, respectively and the parasolitary nucleus. The highest density of c-Fos-positive vestibular nuclear neurons was observed in MVN, where immunolabeled cells were present throughout the rostro-caudal extent of the nucleus. C-Fos expression was concentrated in the parvocellular region and largely absent from magnocellular MVN. C-Fos-labeled cells were scattered throughout caudal SpVN, and the immunostained neurons in SVN were restricted to a discrete wedge-shaped area immediately lateral to the IVth ventricle. Immunofluorescence localization of c-Fos and glutamate revealed that approximately one third of the c-Fos-labeled vestibular neurons showed intense glutamate-like immunofluorescence, far in excess of the stain reflecting the metabolic pool of cytoplasmic glutamate. In the RVLM, which receives a direct projection from the vestibular nuclei and sends efferents to preganglionic sympathetic neurons in the spinal cord, we observed an approximately 3-fold increase in c-Fos labeling in the sGVS-activated rats. We conclude that localization of c-Fos protein following sGVS is a reliable marker for sGVS-activated neurons of the vestibulo-sympathetic pathway.

  19. Betahistine produces post-synaptic inhibition of the excitability of the primary afferent neurons in the vestibular endorgans.

    Science.gov (United States)

    Soto, E; Chávez, H; Valli, P; Benvenuti, C; Vega, R

    2001-01-01

    Betahistine has been used to treat several vestibular disorders of both central and peripheral origin. The objective of this work was to study the action of betahistine in the vestibular endorgans. Experiments were done in wild larval axolotl (Ambystoma tigrinum). Multiunit extracellular recordings were obtained from the semicircular canal nerve using a suction electrode. Betahistine (10 microM to 10 mM; n = 32) inhibited the basal spike discharge of the vestibular afferent neurons with an IC50 of 600 microM. To define the site of action of betahistine, its interactions with the nitric oxide synthase inhibitor NG-nitro-L-arginine (3 microM) and with the cholinergic antagonists atropine (10 microM; n = 3) and d-tubocurarine (10 microM; n = 3) were studied. The action of betahistine when co-administered with these drugs was the same as that in control experiments, indicating that its effects did not include nitric oxide production or the activation of cholinergic receptors. In contrast, 0.01-1 mM betahistine reduced the excitatory action of kainic acid (10 microM; n = 6) and quiscualic acid (1 microM; n = 13). These results indicate that the action of betahistine on the spike discharge of afferent neurons seems to be due to a post-synaptic inhibitory action on the primary afferent neuron response to the hair cell neurotransmitter. PMID:11677735

  20. THE COMPARATIVE CHARACTERISTICS OF BACKGROUND IMPULSE ACTIVITY OF IPSI- AND CONTRALATERAL MEDIAL VESTIBULAR NUCLUS NEURONS IN LABYRINTHECTOMIZED RATS

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    S.H.Sarkisyan

    2011-02-01

    Full Text Available The background neuronal impulse activity of right and left medial vestibular nuclei of rats was carried out in norm and after unilateral labyrinthectomy (UL on 2-d, 7-th, 12-th and 17-th days. It was shown by computer analysis, that characteristics of both nuclei neurons impulse activity in the control group have revealled primery asymmetry of the average freguency of variation (accordingly 16,6±1,7 Hz; and 23,6±1,5 Hz; p<0,01. It is shown that on 7-th day following UL value of the average frequency corresponded to source (16,6±1,2 Hz and 23,6±1,7Hz.We discussed particularities of the process to compensations and functional importance got result.

  1. Inhibitory effects of motilin, somatostatin, [Leu]enkephalin, [Met]enkephalin, and taurine on neurons of the lateral vestibular nucleus: Interactions with ?-aminobutyric acid

    OpenAIRE

    Chan-Palay, Victoria; Ito, Masao; Tongroach, Pavich; Sakurai, Masaki; Palay, Sanford

    1982-01-01

    Motilin, [Met]enkephalin, [Leu]enkephalin, somatostatin, taurine, ?-aminobutyric acid (GABA), and glycine were tested for their effects on Deiters neurons of the lateral vestibular nucleus in rabbits. Iontophoresis was carried out with multibarrelled micropipettes. All four peptides and three amino acids produced depression of neuron firing. No facilitatory responses were observed. The depressant action of each peptide when iontophoresed alone was dose-dependent and was rapid in onset and rec...

  2. Molecular characterization of cholinergic vestibular and olivocochlear efferent neurons in the rodent brainstem.

    OpenAIRE

    Leijon, Sara

    2010-01-01

    The neural code from the inner ear to the brain is dynamically controlled by central nervous efferent feedback to the audio-vestibular epithelium. Although such efference provides the basis for a cognitive control of our hearing and balance, we know surprisingly little about this feedback system. This project has investigated the applicability of a transgenic mouse model, expressing a fluorescent protein under the choline-acetyltransferase (ChAT) promoter, for targeting the cholinergic audio-...

  3. ACTIVITY OF THE INFERIOR VESTIBULAR NUCLEI NEURONS BY STIMULATION OF HYPOTHALAMIC PARAVENTRICULAR AND SUPRAOPTIC NUCLEI IN CONDITIONS OF UNILATERAL LABYRINTHECTOMY COMBINED WITH VIBRATION EXPOSURE

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    S.H. Sarkisyan

    2012-02-01

    Full Text Available We have performed the programmed analysis of changes of frequency of single neuronal spike activity flow of inferior vestibular nucleus (IVN of rats, evoked by high frequency stimulation (HFS of paraventricular (PVN and supraoptic nuclei (SON of hypothalamus in conditions of unilateral labyrinthectomy (UL combined with multi-day vibration exposure (VE. In neurons of the uninjured side of the IVN HFS PVN and SON dominate inhibitory responses (84.50% and 75.80%, respectively, on the affected side also predominate inhibitory responses (55.10% and 48.80% respectively, along with excitatory (28,20% and 43.50% respectively. It is assumed that the dominance of GABAergic effects contribute to vestibular compensation after UL. The results of the morphological and histochemical study confirm the neuroprotective role of VE in condition of UL.

  4. Implantes vestibulares / Vestibular prosthesis

    Scientific Electronic Library Online (English)

    Cristian, Aedo Sánchez; Paul H, Délano Reyes.

    2013-12-01

    Full Text Available La lesión o hipofunción vestibular bilateral (HVB) es un cuadro clínico que provoca oscilopsias y desequilibrio incapacitante que se agrava en oscuridad. Algunas de las causas de HVB son el uso de drogas ototóxicas, enfermedad de Ménière bilateral, enfermedades autoinmunes y degeneración espinocereb [...] elar. El manejo de esta discapacidad es complejo y muchas veces la rehabilitación no logra los objetivos deseados. Una de las alternativas terapéuticas futuras para la HVB y aún en plena fase experimental es el implante vestibular, cuyo funcionamiento en términos generales es similar al de un implante coclear. En esta revisión se analiza la génesis e historia del desarrollo de los implantes vestibulares, sus principales características y el futuro de su implementación. Abstract in english Bilateral vestibular loss (BVL) is a clinic syndrome that produces oscillopsias and disabling disequilibrium, especially in darkness. Some causes of BVL are the use of ototoxic drugs, bilateral Ménière disease, autoinmune ear disorders and spinocerebellar ataxia. The management of this disability is [...] complex and many times the rehabilitation does not accomplish with the desired goals. One future therapeutic alternative for BVL and still in an experimental stage is the vestibular implant, whose overall functioning is similar to a cochlear implant. In this review we analyze the genesis and history of vestibular implant development, its main technical characteristics and the future of its implementation.

  5. Vestibular blueprint in early vertebrates

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    HansStraka

    2013-11-01

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

  6. Compensation of horizontal canal related activity in the medial vestibular nucleus following unilateral labyrinth ablation in the decerebrate gerbil. I. Type I neurons.

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    Newlands, S D; Perachio, A A

    1990-01-01

    The spontaneous activity and dynamic responses to two frequencies (1.3 and 0.13 Hz) of sinusoidal angular horizontal head acceleration of type I neurons in the medial vestibular nucleus were recorded bilaterally in decerebrate Mongolian gerbils (Meriones unguiculatus) under three experimental conditions; normal labyrinth intact, acutely following unilateral labyrinthine lesion, and four to seven weeks following labyrinthine lesion. The mean spontaneous activity and number of detected type I neurons decreased immediately ipsilateral to the lesion but recovered significantly with time. In contrast, spontaneous activity on the contralateral side increased during compensation following hemilabyrinthectomy. The mean response gains at both frequencies of head oscillation were depressed bilaterally and asymmetrically acutely following the lesion such that the response gain of cells on the intact side exceeded that of the neurons recorded on the injured side. After compensation the number of detected type I neurons on the side ipsilateral to the injury increased but remained below normal levels. The mean gains remained depressed but became symmetric with compensation as a result of improvement in the response of ipsilateral neurons. The phase of responses were significantly advanced in the compensated animals. Although response gain is not fully restored, the linearity of the dynamic modulation in compensated animals is improved as evidenced by a continuous modulation of the increased spontaneous activity of neurons contralateral to the hemilabyrinthectomy. It is proposed that this effect is related to the concurrent improvement in the linearity of the horizontal vestibulo-ocular response. Electrical cathodal polarization of the vestibular nerve ipsilateral to the ablated labyrinth was utilized to investigate the relationship between recovery of spontaneous activity and dynamic function. Acutely following hemilabyrinthectomy, cathodal polarization restored activity in second-order type I neurons to near normal levels but their response gain to head rotation remained depressed. Similar galvanic stimulation in compensated animals also elevated ipsilateral spontaneous activity. As in the acute preparation, such stimulation did not modify the response gain or phase. Thus, the improvement in response of type I neurons in the compensated gerbil was not a direct consequence of restoration of spontaneous activity on the side of the injury. PMID:2286238

  7. Vestibular migraine.

    Science.gov (United States)

    Furman, Joseph M; Balaban, Carey D

    2015-04-01

    Vestibular migraine is now considered a distinct diagnostic entity by both the Barany Society and the International Headache Society. The recognition of vestibular migraine as a diagnostic entity required decades and was presaged by several reports indicating that a large proportion of patients with migraine headaches have vestibular symptoms and that a large proportion of patients with undiagnosed episodic vestibular symptoms have migraine headache. Despite the availability of diagnostic criteria for vestibular migraine, challenges to diagnosis include variability in terms of the character of dizziness, the presence or absence of clearly defined attacks, the duration of attacks, and the temporal association between headache or other migrainous features and vestibular symptoms. Also, symptoms of vestibular migraine often overlap with symptoms of other causes of dizziness, especially Ménière's disease and benign paroxysmal positional vertigo (BPPV). This article will discuss the demographics, epidemiology, clinical manifestations, physical examination findings, laboratory testing, comorbidities, treatment options, and pathophysiology of vestibular migraine. Future research in the field of vestibular migraine should include both clinical and basic science efforts to better understand the pathophysiology of this condition. Controlled treatment trials for vestibular migraine are desperately needed. PMID:25728541

  8. Heterotrimeric guanosine triphosphate-binding protein-coupled modulatory actions of motilin on K+ channels and postsynaptic ?-aminobutyric acid receptors in mouse medial vestibular nuclear neurons.

    Science.gov (United States)

    Todaka, Hiroshi; Tatsukawa, Tetsuya; Hashikawa, Tsutomu; Yanagawa, Yuchio; Shibuki, Katsuei; Nagao, Soichi

    2013-02-01

    Some central nervous system neurons express receptors of gastrointestinal hormones, but their pharmacological actions are not well known. Previous anatomical and unit recording studies suggest that a group of cerebellar Purkinje cells express motilin receptors, and motilin depresses the spike discharges of vestibular nuclear neurons that receive direct cerebellar inhibition in rats or rabbits. Here, by the slice-patch recording method, we examined the pharmacological actions of motilin on the mouse medial vestibular nuclear neurons (MVNs), which play an important role in the control of ocular reflexes. A small number of MVNs, as well as cerebellar floccular Purkinje cells, were labeled with an anti-motilin receptor antibody. Bath application of motilin (0.1 ?m) decreased the discharge frequency of spontaneous action potentials in a group of MVNs in a dose-dependent manner (K(d) , 0.03 ?m). The motilin action on spontaneous action potentials was blocked by apamin (100 nm), a blocker of small-conductance Ca(2+) -activated K(+) channels. Furthermore, motilin enhanced the amplitudes of inhibitory postsynaptic currents (IPSCs) and miniature IPSCs, but did not affect the frequencies of miniature IPSCs. Intracellular application of pertussis toxin (PTx) (0.5 ?g/?L) or guanosine triphosphate-?-S (1 mm) depressed the motilin actions on both action potentials and IPSCs. Only 30% of MVNs examined on slices obtained from wild-type mice, but none of the GABAergic MVNs that were studied on slices obtained from vesicular ?-aminobutyric acid transporter-Venus transgenic mice, showed such a motilin response on action potentials and IPSCs. These findings suggest that motilin could modulate small-conductance Ca(2+) -activated K(+) channels and postsynaptic ?-aminobutyric acid receptors through heterotrimeric guanosine triphosphate-binding protein-coupled receptor in a group of glutamatergic MVNs. PMID:23136934

  9. A new evaluation of vestibular compensation.

    Science.gov (United States)

    Sasaki, O; Taguchi, K

    1994-01-01

    Vestibular compensation process in six patients was examined by means of static (SPG) and kinetic posturography (KPG). SPG was recorded by a stabilometer during standing and KPG was recorded by POLGON so that angular change of shoulder in the frontal plane was measured during stepping. The subjects included three cases with vestibular neuronitis, three cases with bilateral vestibular loss. In vestibular neuronitis, SPG improved earlier than KPG. As a result of vestibular training, initial high levels of SPG and KPG fall precipitously and in the case with sequela, a remarkably high level of KPG gradually decreased. In bilateral vestibular loss, abnormality of KPG tended to persist and those results would be due to the disappearance of a hip strategy. The effect of training upon the case which started from the early days was not shown. However, the case which started from 10 months after the onset showed remarkable improvement of SPG and KPG. PMID:7872890

  10. ACTIVITY OF THE SUPERIOR VESTIBULAR NUCLEI NEURONS AT STIMULATION OF HYPOTHALAMIC PARAVENTRICULAR AND SUPRAOPTIC NUCLEI IN CONDITIONS OF UNILATERAL LABYRINTHECTOMY COMBINED WITH VIBRATION EXPOSURE

    Directory of Open Access Journals (Sweden)

    S.H. Sarkisyan

    2010-05-01

    Full Text Available We studied the frequency changes of single neuronal spike activity flow from superior vestibular nucleus (SVN, evoked on high frequency stimulation (HFS of paraventricular (PV and supraoptic (SO nuclei of hypothalamus in Albino rats in conditions of unilateral labyrinthectomy (UL combined with many days of vibration exposure (VE. Programmed mathematical on-lin? analysis was used. In normal conditions, at bilateral stimulation of PV and SO nuclei the tetanic potentiation (TP prevaled. After UL in control at uninjured side TP and posttetanic potentiation (PTP were recorded; on injured side, on the whole, along with variability of initial background activity of SVN neurons, an exiguity of components and of the repeatability of poststimulus excitatory and inhibitory manifestations of SVN neurons’ activity were recorded. Combined action of UL and VE at intact side evoked tetanic depression on ipsilateral stimulation of PV and SO nuclei; on injured side the stimulation of the same nuclei evoked TP and PTP, which achieved normal levels. The results of histochemical investigation in analogous experimental conditions confirmed the electrophysiological data, which allowed us concluding about protective effect of VE.

  11. BASIC CONCEPTS IN UNDERSTANDING RECOVERY OF FUNCTION IN VESTIBULAR REFLEX NETWORKS DURING VESTIBULAR COMPENSATION

    Directory of Open Access Journals (Sweden)

    KennaPeusner

    2012-02-01

    Full Text Available Unilateral peripheral vestibular lesions produce a syndrome of oculomotor and postural deficits with the symptoms at rest, the static symptoms, partially or completely normalizing shortly after the lesion due to a process known as vestibular compensation. The symptoms are thought to result from changes in the activity of vestibular sensorimotor reflexes. Since the vestibular nuclei must be intact for recovery to occur, many investigations have focused on studying these neurons after lesions. At present, the neuronal plasticity underlying early recovery from the static symptoms is not fully understood. Here we propose that knowledge of the reflex identity and input-output connections of the recorded neurons is essential to link the responses to animal behavior. We further propose that the cellular mechanisms underlying vestibular compensation can be sorted out by characterizing the synaptic responses and time course for change in morphologically-defined subsets of vestibular reflex projection neurons. Accordingly, this review focuses on the perspective gained by performing electrophysiological and immunolabeling studies on a specific subset of morphologically-defined, glutamatergic vestibular reflex projection neurons, the principal cells of the chick tangential nucleus. Reference is made to pertinent findings from other studies on vestibular nuclei neurons, but no comprehensive review of the literature is intended since broad reviews already exist. From recording excitatory and inhibitory spontaneous synaptic activity in principal cells, we find that the rebalancing of excitatory synaptic drive bilaterally is essential for vestibular compensation to proceed. This work is important for it defines for the first time the excitatory and inhibitory nature of the changing synaptic inputs and the time course for changes in a morphologically-defined subset of vestibular reflex projection neurons during early stages of vestibular compensation.

  12. What Galvanic Vestibular Stimulation Actually Activates

    OpenAIRE

    IanSCurthoys

    2012-01-01

    In a recent paper in Frontiers Cohen et al. (2012) asked “What does galvanic vestibular stimulation actually activate?” and concluded that galvanic vestibular stimulation (GVS) causes predominantly otolithic behavioural responses. In this Perspective paper we show that such a conclusion does not follow from the evidence. The evidence from neurophysiology is very clear: galvanic stimulation activates primary otolithic neurons as well as primary semicircular canal neurons (Kim and Curthoys,...

  13. Betahistine, vestibular function and compensation: in vitro studies of vestibular function and plasticity.

    Science.gov (United States)

    Dutia, M B

    2000-01-01

    Histamine has an excitatory action on rat medial vestibular nucleus neurones in vitro, an effect that is mediated by histamine H1 and H2 receptors. Betahistine, which is a weak agonist at the H1 receptor and a moderate antagonist at the presynaptic H3 autoreceptor, weakly excites medial vestibular nucleus cells but antagonizes their responses to histamine. Experiments were carried out on rat medial vestibular nucleus cells in vitro using slices prepared from animals that had undergone unilateral labyrinthectomy (UL). There was a significant increase in the intrinsic excitability of medial vestibular nucleus cells in the rostral region of the ipsi-lesional nucleus within 4 h post-UL, which was sustained for the following week. These changes in intrinsic excitability of the medial vestibular nucleus neurones were abolished in animals that were not exposed to the secretion of stress hormones that normally occurs following UL. Histamine is also released in response to the stress associated with vestibular dysfunction. It is possible that the beneficial effects of betahistine on vestibular compensation are related to an interaction between histaminergic receptors activated by the parallel release of histamine and the activation of glucocorticoid receptors through the activation of the stress axis. Further study of the interactions between histamine receptors and the activation of the stress axis may be useful in understanding the effects of betahistine on vestibular plasticity. PMID:10904795

  14. Procedures for restoring vestibular disorders

    Directory of Open Access Journals (Sweden)

    Walther, Leif Erik

    2005-09-01

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

  15. Electrical Vestibular Stimulation after Vestibular Deafferentation and in Vestibular Schwannoma

    Science.gov (United States)

    Aw, Swee Tin; Todd, Michael John; Lehnen, Nadine; Aw, Grace Elizabeth; Weber, Konrad Peter; Eggert, Thomas; Halmagyi, Gabor Michael

    2013-01-01

    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. PMID:24349188

  16. Vestibular migraine : Diagnostic criteria

    DEFF Research Database (Denmark)

    Lempert, Thomas; Olesen, Jes

    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. Symptoms that qualify for a diagnosis of vestibular migraine include various types of vertigo as well as head motion-induced dizziness with nausea. Symptoms must be of moderate or severe intensity. Duration of acute episodes is limited to a window of between 5 minutes and 72 hours.

  17. What galvanic vestibular stimulation actually activates

    Directory of Open Access Journals (Sweden)

    IanSCurthoys

    2012-07-01

    Full Text Available In a recent paper in Frontiers Cohen et al. (2012 asked “What does galvanic vestibular stimulation actually activate?” and concluded that galvanic vestibular stimulation (GVS causes predominantly otolithic behavioural responses. In this Perspective paper we show that such a conclusion does not follow from the evidence. The evidence from neurophysiology is very clear: galvanic stimulation activates primary otolithic neurons as well as primary semicircular canal neurons (Kim and Curthoys, 2004. Irregular neurons are activated at lower currents. The answer to what behaviour is activated depends on what is measured and how it is measured, including not just technical details, such as the frame rate of video, but the exact experimental context in which the measurement took place (visual fixation vs total darkness. Both canal and otolith dependent responses are activated by GVS.

  18. What galvanic vestibular stimulation actually activates.

    Science.gov (United States)

    Curthoys, Ian S; Macdougall, Hamish Gavin

    2012-01-01

    In a recent paper in Frontiers Cohen et al. (2012) asked "What does galvanic vestibular stimulation actually activate?" and concluded that galvanic vestibular stimulation (GVS) causes predominantly otolithic behavioral responses. In this Perspective paper we show that such a conclusion does not follow from the evidence. The evidence from neurophysiology is very clear: galvanic stimulation activates primary otolithic neurons as well as primary semicircular canal neurons (Kim and Curthoys, 2004). Irregular neurons are activated at lower currents. The answer to what behavior is activated depends on what is measured and how it is measured, including not just technical details, such as the frame rate of video, but the exact experimental context in which the measurement took place (visual fixation vs total darkness). Both canal and otolith dependent responses are activated by GVS. PMID:22833733

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

    Science.gov (United States)

    Lacour, Michel; Bernard-Demanze, Laurence

    2015-01-01

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

  20. 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. PMID:25992098

  1. Integration of vestibular and head movement signals in the vestibular nuclei during whole-body rotation

    Science.gov (United States)

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

    1999-01-01

    Single-unit recordings were obtained from 107 horizontal semicircular canal-related central vestibular neurons in three alert squirrel monkeys during passive sinusoidal whole-body rotation (WBR) while the head was free to move in the yaw plane (2.3 Hz, 20 degrees /s). Most of the units were identified as secondary vestibular neurons by electrical stimulation of the ipsilateral vestibular nerve (61/80 tested). Both non-eye-movement (n = 52) and eye-movement-related (n = 55) units were studied. Unit responses recorded when the head was free to move were compared with responses recorded when the head was restrained from moving. WBR in the absence of a visual target evoked a compensatory vestibulocollic reflex (VCR) that effectively reduced the head velocity in space by an average of 33 +/- 14%. In 73 units, the compensatory head movements were sufficiently large to permit the effect of the VCR on vestibular signal processing to be assessed quantitatively. The VCR affected the rotational responses of different vestibular neurons in different ways. Approximately one-half of the units (34/73, 47%) had responses that decreased as head velocity decreased. However, the responses of many other units (24/73) showed little change. These cells had signals that were better correlated with trunk velocity than with head velocity. The remaining units had responses that were significantly larger (15/73, 21%) when the VCR produced a decrease in head velocity. Eye-movement-related units tended to have rotational responses that were correlated with head velocity. On the other hand, non-eye-movement units tended to have rotational responses that were better correlated with trunk velocity. We conclude that sensory vestibular signals are transformed from head-in-space coordinates to trunk-in-space coordinates on many secondary vestibular neurons in the vestibular nuclei by the addition of inputs related to head rotation on the trunk. This coordinate transformation is presumably important for controlling postural reflexes and constructing a central percept of body orientation and movement in space.

  2. Vestibular-Podokinetic interaction without vestibular perception.

    Science.gov (United States)

    Melvill Jones, G; Fletcher, W A; Weber, K D; Block, E W

    2005-12-01

    After prolonged stepping in place relative to space over the center of a rotating turntable, blindfolded subjects cannot step on the stationary platform without unknowingly turning themselves relative to space, a phenomenon termed podokinetic after rotation (PKAR). We asked what role the resulting vestibular stimulation might play in the expression of this form of PKAR. A method of servo-stabilizing the body relative to space during PKAR was devised to compare PKAR expression with and without significant vestibular stimulation. Simulated estimates of average central vestibular response profiles were obtained by passing the averaged unidirectional body angular velocity profiles relative to space through a first-order model of the canal system (tau=15 s). Such simulation results suggested that during normal PKAR performed on a stationary platform, the average central vestibular response would likely rise to peak levels equivalent to that induced by about 9 degrees /s within the frequency range of natural head movement. In the servo-stabilized condition, the simulated response was reduced to insignificant levels. Experimental results demonstrated that in the unstabilized condition the rate of rise of PKAR angular velocity was roughly four times slower than in the stabilized condition. We conclude that the normal expression of PKAR conducted on a stationary platform tends to be substantially slowed by interaction with an unperceived vestibular response. PMID:16292636

  3. Noise Induced Vestibular Damage

    Directory of Open Access Journals (Sweden)

    Maryam Emadi

    1999-03-01

    Full Text Available There are increasing evidences about the vestibular damage caused by the exposure to noise. Histological and functional derangements of the vestibular system have been reported in laboratory animals exposed to high levels of noise. However, clinical series describe contradictory results with regard to vestibular disturbances in industrial workers and military personnel suffering from noise induced hearing loss (NIHL. Animal studies have proved that crista ampullaris bears the most disturbances, though some damages have been also detected in macula of the utricle and saccule and utricle. These changes have been induced due to acoustical pressure on the vestibular labyrinth. The findings from the experiments regarding vestibular function in patients suffering NIHL have shown a paramount diminish in vestibulo-occular Reflex (VOR. The correlation among NIHL, VOR and unilateral caloric weakness were statistically significant which can be due to a common mechanism of disturbances in the function of cochlea and vestibule.

  4. Deregulated genes in sporadic vestibular schwannomas

    DEFF Research Database (Denmark)

    Cayé-Thomasen, Per; Helweg-Larsen, Rehannah Holga Andrea

    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.

  5. Specific vestibular exercises in the treatment of vestibular neuritis

    Directory of Open Access Journals (Sweden)

    Komazec Zoran

    2004-01-01

    Full Text Available Introduction Vestibular neuritis rapidly damages unilateral vestibular periphery, inducing severe balance disorders. In most cases, such vestibular imbalance is gradually restored to within the normal level after clinical therapies. This successive clinical recovery occurs due to regeneration of vestibular periphery and/or accomplishment of central vestibular compensation. Rehabilitation The program of vestibular rehabilitation presents a major achievement in the field of treatment of balance disorders. Vestibular compensation is associated with central sensory reintegration and bilaterally equalizes the vestibular tonus over a period of time. Material and methods In this retrospective study of a series of cases authors present their results in 58 patients undergoing a program of vestibular rehabilitation. Patients were divided into two groups. Thirty patients were in group I, and 28 in group II. Specific vestibular exercises were conducted in group I, and non-specific exercises in group II. Analysis of effects of vestibular compensation was made due electronystagmography. Results Results were satisfactory in both groups of patients. Absence of spontaneous nystagmus was detected in 83.3% of patients in group I (specific vestibular exercises and in 53.5% of patients in group II (non-specific exercises, with an average treatment time of up to 2 months. Harmonization of pendular stimulation was detected in 83.3% and 60.7% of patients in groups I and II, respectively. Conclusion Early physiotherapeutic vestibular rehabilitation supports the vestibular compensation mechanism. At the same time vestibular rehabilitation may prevent panic disorder caused by hyperventilation syndrome.

  6. Vestibular pathways involved in cognition

    OpenAIRE

    Martin Hitier

    2014-01-01

    Recent discoveries have emphasized the role of the vestibular system in cognitive processes such as memory, spatial navigation and bodily self-consciousness. A precise understanding of the vestibular pathways involved is essential to understand the consequences of vestibular diseases for cognition, as well as develop therapeutic strategies to facilitate recovery. The knowledge of the “vestibular cortical projections areas”, defined as the cortical areas activated by vestibular stimulation...

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

    Scientific Electronic Library Online (English)

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

    2014-09-01

    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 ves [...] tibular 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.

  8. Widespread vestibular activation of the rodent cortex.

    Science.gov (United States)

    Rancz, Ede A; Moya, Javier; Drawitsch, Florian; Brichta, Alan M; Canals, Santiago; Margrie, Troy W

    2015-04-15

    Much of our understanding of the neuronal mechanisms of spatial navigation is derived from chronic recordings in rodents in which head-direction, place, and grid cells have all been described. However, despite the proposed importance of self-reference information to these internal representations of space, their congruence with vestibular signaling remains unclear. Here we have undertaken brain-wide functional mapping using both fMRI and electrophysiological methods to directly determine the spatial extent, strength, and time course of vestibular signaling across the rat forebrain. We find distributed activity throughout thalamic, limbic, and particularly primary sensory cortical areas in addition to known head-direction pathways. We also observe activation of frontal regions, including infralimbic and cingulate cortices, indicating integration of vestibular information throughout functionally diverse cortical regions. These whole-brain activity maps therefore suggest a widespread contribution of vestibular signaling to a self-centered framework for multimodal sensorimotor integration in support of movement planning, execution, spatial navigation, and autonomic responses to gravito-inertial changes. PMID:25878265

  9. 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.

  10. Comorbidities in vestibular migraine.

    Science.gov (United States)

    Eggers, Scott D Z; Neff, Brian A; Shepard, Neil T; Staab, Jeffrey P

    2014-01-01

    A growing body of clinical and epidemiological evidence supports a specific relationship between vestibular symptoms and migraine. Without a biomarker or complete understanding of pathophysiology, diagnosis of vestibular migraine (VM) currently depends upon symptoms in two dimensions: episodic vestibular symptoms temporally related to migraine symptoms. The Bárány Society and the International Headache Society have recently developed consensus diagnostic criteria. However, many issues remain unsettled, including the type, duration, and timing of vestibular symptoms related to headache that should be required for diagnosing VM. This paper focuses on the challenging third dimension of comorbidity, a frequent cause of diagnostic uncertainty that may confound clinical application and research validation of VM criteria. Several other neurotologic conditions occur more frequently in migraineurs than controls, including benign paroxysmal positional vertigo, Ménière's disease, and motion sickness. Patients with VM also have high rates of chronic subjective dizziness, which may be associated with anxious, introverted temperaments that can affect clinical presentation and treatment response. Broadly inclusive studies of well-characterized patients with other neurotologic and psychiatric comorbidities are needed to fully understand how vestibular symptoms and migraine interact in order to truly validate vestibular migraine, distill its essential features, define its boundaries, and characterize overlapping comorbidities. PMID:25564081

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

    Directory of Open Access Journals (Sweden)

    M. V. Zamergrad

    2014-10-01

    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 vestibularcompensation. During visits 2, 3, and 4, the symptoms of the disease were recorded in the patients and the time course of treatment-induced changes in their status was estimated.Results. The optimal duration of treatment was established to be at least 2 months. Vestibular exercises in combination with the intake of tanakan resulted in a reduction in the symptoms of vestibular dysfunction and in emotional improvement in the patients.

  12. New insights into pathophysiology of vestibular migraine.

    Science.gov (United States)

    Espinosa-Sanchez, Juan M; Lopez-Escamez, Jose A

    2015-01-01

    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 gray, 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 mechanisms of VM. PMID:25705201

  13. Vestibular evoked myogenic potential

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    Lemaji?-Komazec Slobodanka

    2014-01-01

    Full Text Available Introduction. Vestibular evoked myogenic potentials are neurophysiological method for examining of saccular function, the bottom of the vestibular nerve that in nervates the sacculus and central vestibular pathways. Those are inhibitory potentials of the sternocleido mastoid musclein response to ipsilateral acoustic stimulation of the sacculus. Parameters of vestibular evoked myogenic potential testing include threshold, latencies of p1 and n1 wave and interamplitude p13-n23, interaural difference of p13 and n23 latency and interaural amplitude difference ratio. The aim of this study was to compire parameters standardization of vestibular evoked myogenic potentials responses, latency p13 and n23 of waves, the amplitude of responses and interaural differences in the amplitude andto determinewhether there is a difference in values between the sexes. Material and methods. This research was meant to be a prospective study which included 30 normal audiovestibular volunteers of both sexes. The group consisted of 53.3% women and 46.7% men. The saccular function testing by vestibular evoked myogenic potentials was performed monoaurally using air-conductive 500 Hz tone burst auditory stimulation. Results. The average value of the p13 wave latency in healthy subjects of this study was 15.18 ms (±1.24 while the mean latency of n23 waves in the same subjects was 25.00 ms (±2.23. The average value of the amplitude of the p13-n23 waves was 80.28 (34. ±04 microvolts. Conclusion. The difference in the values of the basic parameters of vestibular evoked myogenic potential responses between men and women does not exist. No differences between the right and the left ear in the values of latency and amplitude were observed.

  14. [The vestibular system: from structure to function].

    Science.gov (United States)

    Collard, M

    1994-02-01

    The two vestibular receptors, right and left, hidden in the petrous part of the temporal bone with the cochlear receptors, receive information from angular and linear movements of the head and transform them into a nerve message sent to the nuclei of the brainstem, which are connected directly on the one hand to the oculomotor nuclei, at the origin of the oculovestibular reflex (induction of nystagmus), and on the other hand, to the spinal motor neurons, at the origin of the vestibulospinal reflex. These reflexes are associated with responses to visual and somaesthetic information for maintenance or return to the standing position, which characterises the function of equilibrium. Vertigo and disorders of balance reflect a conflict of information between these two labyrinths, or between the vestibular apparatus and the messages issued by other captors, and sometimes also dysfunction of central nervous system treatment of information or a lesion of the effector motor systems. PMID:8178092

  15. Vestibular modulation of spatial perception

    OpenAIRE

    Ferrè, Elisa R.; Longo, Matthew R.; Fiori, Federico; Haggard, Patrick

    2013-01-01

    Vestibular inputs make a key contribution to the sense of one’s own spatial location. While the effects of vestibular stimulation on visuo-spatial processing in neurological patients have been extensively described, the normal contribution of vestibular inputs to spatial perception remains unclear. To address this issue, we used a line bisection task to investigate the effects of galvanic vestibular stimulation (GVS) on spatial perception, and on the transition between near and far space. B...

  16. Vestibular migraine: Diagnosis and treatment

    Directory of Open Access Journals (Sweden)

    Batuecas-Caletrio A

    2013-03-01

    Full Text Available Vestibular migraine is one of the most common causes of recurrent vertigo. Ocasionally, diagnosis of vestibular migraine can not be easy because of variety of clinical manifestations. A good characterization of the vestibular migraine and goods diagnostic criteria are necessary in order to treat the vestibular migraine easily. In the other hand, the treatment of vestibular migraine is similar to the treatment of migraine, both acute crisis and preventive treatment. There are several consensus papers in diagnosis and treatment that are analized in this work.

  17. Recovery from vestibular ototoxicity

    Science.gov (United States)

    Black, F. O.; Gianna-Poulin, C.; Pesznecker, S. C.

    2001-01-01

    OBJECTIVE: Determine whether subjects with documented vestibular ototoxicity recover vestibular function and, if so, investigate the recovery dynamics. STUDY DESIGN: Prospective and retrospective reviews and repeated measures. SETTING: Clinical research and technology center. SUBJECTS: Twenty-eight subjects who received vestibulotoxic medications were followed for at least 12 months after initial treatment. CONTROLS: Our subject sample was compared with a published database of normal individuals. INTERVENTIONS: All 28 subjects received systemically administered medications known to be ototoxic. The subjects' treating physicians controlled medication, dosage, and administration schedules. MAIN OUTCOME MEASURES: Tests of horizontal canal vestibulo-ocular function were performed. Subjects' auditory and vestibular symptoms were recorded. RESULTS: Eleven subjects (39%) showed changes in horizontal canal vestibulo-ocular gain constant (GC) and/or time constant (TC) consistent with vestibular ototoxicity. When tested 1 year after ototoxic drug administration, eight of the nine subjects who experienced ototoxic decrease in GC showed a recovery of GC to normal limits. Only one of the eight subjects who experienced ototoxic decrease in TC showed recovery of TC to within normal limits. Ototoxicity onset and recovery were independent of baseline vestibular function, and ototoxicity onset did not correlate with cumulative dose of ototoxic medication. There was no relationship between subjective symptoms and ototoxicity onset. CONCLUSIONS: Recovery of GC after vestibular ototoxicity is more commonly observed than recovery of TC. Because ototoxic changes developed and continued in an unpredictable time and manner in relation to ototoxic drug administration, we propose that once ototoxic changes in vestibulo-ocular reflex are detected, ototoxic medications should be discontinued as soon as possible.

  18. Vestibular-Ocular Reflex

    Science.gov (United States)

    Marlene Y. MacLeish, Ed.D.

    2013-01-30

    In this activity, learners will perform various investigations to understand the vestibular-ocular reflex and learn about the importance of visual cues in maintaining balance. During the two-part activity, learners will compare the stability of a moving image under two conditions as well as compare the effects of rotation on the sensation of spinning under varying conditions. This lesson guide includes background information, review and critical thinking questions with answers, and handouts. Educators can also use this activity to discuss how the brain functions in space and how researchers study the vestibular function in space.

  19. Correlation of Fos expression and circling asymmetry during gerbil vestibular compensation

    Science.gov (United States)

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

    1999-01-01

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

  20. Vestibular Schwannoma (Acoustic Neuroma) and Neurofibromatosis

    Science.gov (United States)

    ... Schwannoma (Acoustic Neuroma) and Neurofibromatosis Vestibular Schwannoma (Acoustic Neuroma) and Neurofibromatosis On this page: What is a ... additional information? What is a vestibular schwannoma (acoustic neuroma)? A vestibular schwannoma (also known as acoustic neuroma , ...

  1. Audiologic diagnostics of vestibular schwannoma

    Directory of Open Access Journals (Sweden)

    Komazec Zoran

    2004-01-01

    Full Text Available Introduction Vestibular schwannoma (acoustic neuroma is a rare, but important cause of sensorineural hearing loss. Patients with asymmetric hearing loss, or unilateral tinnitus should be evaluated expeditiously, to prevent further neurological damage. Audiologic diagnostics Audiologic diagnostics represents the basic diagnosis for early detection of vestibular schwannoma. Patients with vestibular schwannomas may present with a variety of clinical features, including retrocochlear pattern of sensorineural hearing loss. Supraliminary audiometry, tympano- metry, stapedius reflex and otoacoustic emissions as well as vestibular response to caloric testing are methods for selection of patients with suspicion of this tumor. Conclusion The golden standard for audiologic diagnostics of vestibular schwannoma is BAEP (Brainstem Auditory Evoked Potentials. Patients with pathological findings of BAEP should undergo MRI of the posterior fossa. Gadolinium-enhanced magnetic resonance imaging is the best and final tool for making a diagnosis of vestibular schwannoma.

  2. Vestibular pathways involved in cognition

    Directory of Open Access Journals (Sweden)

    Martin Hitier

    2014-07-01

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

  3. Vestibular Schwanomma with normal hearing

    OpenAIRE

    Ravikumar, A.; Singh, P.; Batish, V. K.

    1999-01-01

    Schwanomma of the vestibular nerves usually present with sensorineural hearing loss of varying degrees. We report here a large (5.5cm x 3.5cm) vestibular schwanomma with normal hearing. Other unusual features of this case were the young age (20 yrs) of the patient and absence of any otological symptoms.

  4. Hypervascular vestibular Schwannoma: A case report

    International Nuclear Information System (INIS)

    Most vestibular schwannoma is hypovascular with well known poor tumor staining in cerebral angiography. However, hypervascular vestibular schwannoma might be observed as a rare subtype with increased risk of bleeding during surgery. Multimodal imaging features which represent hypervascularity of the tumor can be observed in hypervascular vestibular schwannoma. Here we report a case of hypervascular vestibular schwannoma with brief literature review.

  5. Hypervascular vestibular Schwannoma: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ja Young; Yu, In Kyu [Dept. of Radiology, Eulji University Hospital, Daejeon (Korea, Republic of)

    2014-11-15

    Most vestibular schwannoma is hypovascular with well known poor tumor staining in cerebral angiography. However, hypervascular vestibular schwannoma might be observed as a rare subtype with increased risk of bleeding during surgery. Multimodal imaging features which represent hypervascularity of the tumor can be observed in hypervascular vestibular schwannoma. Here we report a case of hypervascular vestibular schwannoma with brief literature review.

  6. [Function returning without and with recovery nystagmus after sudden unilateral isolated vestibular loss (author's transl)].

    Science.gov (United States)

    Minnigerode, B; Meissner, R

    1979-01-01

    The restoration of peripher labyrinthine excitability after sudden unilateral isolated vestibular loss shows a different behaviour: It can happen with or without recovery nystagmus with a numerical nearly equal frequency. In a follow-up of 44 patients with unilateral vestibular loss of vascular genetics the objective and subjective characteristics of both states are described. In explanation of it a lesion of variable etiology in the region of the vestibular artery and a supposition of a not yet or already occured compensation of the disturbed tonus balance in the nuclear area are not sufficient. Rather the origin of the different clinical states of recovery phenomenon must be presumed in all probability as the result of a primary and secondary retrograde degeneration of the vestibular neurons. Thereby the distance of the lesion from the Scarpa ganglion is presumably of decisive importance. PMID:317643

  7. Processing of vestibular inputs by the medullary lateral tegmental field of conscious cats: implications for generation of motion sickness

    Science.gov (United States)

    McCall, Andrew A.; Moy, Jennifer D.; DeMayo, William M.; Puterbaugh, Sonya R.; Miller, Daniel J.; Catanzaro, Michael F.

    2013-01-01

    The dorsolateral reticular formation of the caudal medulla, the lateral tegmental field (LTF), participates in generating vomiting. LTF neurons exhibited complex responses to vestibular stimulation in decerebrate cats, indicating that they received converging inputs from a variety of labyrinthine receptors. Such a convergence pattern of vestibular inputs is appropriate for a brain region that participates in generating motion sickness. Since responses of brainstem neurons to vestibular stimulation can differ between decerebrate and conscious animals, the current study examined the effects of whole-body rotations in vertical planes on the activity of LTF neurons in conscious felines. Wobble stimuli, fixed-amplitude tilts, the direction of which moves around the animal at a constant speed, were used to determine the response vector orientation, and also to ascertain whether neurons had spatial–temporal convergence (STC) behavior (which is due to the convergence of vestibular inputs with different spatial and temporal properties). The proportion of LTF neurons with STC behavior in conscious animals (25 %) was similar to that in decerebrate cats. Far fewer neurons in other regions of the feline brainstem had STC behavior, confirming findings that many LTF neurons receive converging inputs from a variety of labyrinthine receptors. However, responses to vertical plane vestibular stimulation were considerably different in decerebrate and conscious felines for LTF neurons lacking STC behavior. In decerebrate cats, most LTF neurons had graviceptive responses to rotations, similar to those of otolith organ afferents. However, in conscious animals, the response properties were similar to those of semicircular canal afferents. These differences show that higher centers of the brain that are removed during decerebration regulate the labyrinthine inputs relayed to the LTF, either by gating connections in the brainstem or by conveying vestibular inputs directly to the region. PMID:23274644

  8. Enlarged Vestibular Aqueduct Syndrome (EVAS)

    Science.gov (United States)

    ... Canal Dehiscence (SCD) Tinnitus Vestibular Hyperacusis Vision & Hearing Psychology Other Topics Military Resources Paid Advertisement Meniere's Disease ... People with EVAS are cautioned to avoid contact sports and must wear a helmet while bicycling and ...

  9. Betahistine increases vestibular blood flow.

    Science.gov (United States)

    Dziadziola, J K; Laurikainen, E L; Rachel, J D; Quirk, W S

    1999-03-01

    Betahistine is used for treatment of several vestibular disorders. Despite the accepted use of this histamine-like substance, its mechanism of action is not well understood. The purpose of this study was to assess the possibility that one of the activities of betahistine is increasing blood flow in the peripheral vestibular end organs. Using a novel surgical approach, we identified the posterior semicircular canal ampulla of guinea pigs and placed a laser Doppler probe in position to obtain blood flow measurements from the posterior semicircular canal ampulla. Blood pressure, heart rate, and vestibular blood flow were continuously recorded. Concentration-response curves were obtained for betahistine (2.5, 5, 7.5, and 10 mg/kg) and control-vehicle (0.15 mol/L NaCl) infusions. A separate group of subjects was pretreated with the competitive selective H3 agonist, thioperimide maleate, before betahistine treatment. Increases in vestibular blood flow and decreases in blood pressure were observed in response to betahistine infusions. Pretreatment with thioperamide maleate abolished these changes at low doses of betahistine and attenuated the responses at higher doses of betahistine. These results show that betahistine administration induces increases in vestibular blood flow. These findings support the potential use of betahistine for treatment of vestibular disorders, which may be caused by compromised circulation. PMID:10064646

  10. Atypical Manifestation of Vestibular Schwannoma

    Scientific Electronic Library Online (English)

    Guilherme, Webster; Rui Carlos, Ortega Filho; Antonini de Oliveira e, Sousa; Marcio Cavalcante, Salmito; Mariana Lopes, Favero; Patricia Maria Sens, Marques.

    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 an [...] d 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.

  11. Melanocortinergic circuits from medial vestibular nuclei to the kidney defined by transneuronal transport of pseudorabies virus.

    Science.gov (United States)

    Shang, Dan; Xiong, Jun; Xiang, Hong-Bing; Hao, Yan; Liu, Jiu-Hong

    2015-01-01

    This study was designed to assess whether MC4R signaling existed in vestibular nuclei modulated the activity of kidney by a virally mediated transsynaptic tracing study. Pseudorabies virus (PRV)-614 was injected into the kidney in adult male MC4R-green fluorescent protein (GFP) transgenic mice (n = 5). After a survival time of 5 days, the mice were assigned to humanely sacrifice, and the brainstem were removed and sectioned, and processed for PRV-614 visualization. The neurochemical phenotype of MC4R-GFP-positive neurons was identified using fluorescence immunocytochemical labeling. PRV-614/MC4R-GFP dual labeled neurons were detected in medial vestibular nuclei. Our findings support the hypothesis that there exist melanocortinergic circuits from medial vestibular nuclei to the kidney. PMID:25973095

  12. Differential diagnosis and treatment of vestibular vertigo

    Directory of Open Access Journals (Sweden)

    Vladimir Anatolyevich Parfenov

    2010-06-01

    Full Text Available Vertigo is a common complaint that leads patients to visit physicians of various specialties. Diseases resulting in vestibular vertigo are very diverse and may be caused by lesion of both the central parts of the vestibular system and the peripheral vestibular apparatus. In many cases, its diagnosis can be made from complaints and a history of disease and special bedside tests requiring no sophisticated equipment. Management of vestibular vertigo should aim at treating the underlying disease; vestibular dilators as symptomatic therapy can be effective for several days. Vestibular exercises the efficiency of which can be enhanced by betahistine and other drugs accelerating vestibular compensation should be further needed. Data on the efficacy of betaver (betahistine in patients with vestibular vertigo are given.

  13. Ocular Vestibular Evoked Myogenic Potentials

    Scientific Electronic Library Online (English)

    Lilian, Felipe; Herman, Kingma.

    2014-01-01

    Full Text Available Introduction? Diagnostic testing of the vestibular system is an essential component of treating patients with balance dysfunction. Until recently, testing methods primarily evaluated the integrity of the horizontal semicircular canal, which is only a portion of the vestibular system. Recent advance [...] s in technology have afforded clinicians the ability to assess otolith function through vestibular evoked myogenic potential (VEMP) testing. VEMP testing from the inferior extraocular muscles of the eye has been the subject of interest of recent research. Objective? To summarize recent developments in ocular VEMP testing. Results? Recent studies suggest that the ocular VEMP is produced by otolith afferents in the superior division of the vestibular nerve. The ocular VEMP is a short latency potential, composed of extraocular myogenic responses activated by sound stimulation and registered by surface electromyography via ipsilateral otolithic and contralateral extraocular muscle activation. The inferior oblique muscle is the most superficial of the six extraocular muscles responsible for eye movement. Therefore, measurement of ocular VEMPs can be performed easily by using surface electrodes on the skin below the eyes contralateral to the stimulated side. Conclusion? This new variation of the VEMP procedure may supplement conventional testing in difficult to test populations. It may also be possible to use this technique to evaluate previously inaccessible information on the vestibular system.

  14. Reabilitação vestibular: tendências e indicações

    Directory of Open Access Journals (Sweden)

    Clarissa Stefani Teixeira

    2010-08-01

    Full Text Available A reabilitação vestibular classicamente indicada no tratamento das disfunções do aparelho vestibular vem sendo cada vez mais prescrita para pessoas com outras problemáticas relacionadas ao equilíbrio e a orientação espacial. Este estudo de cunho bibliográfico teve por objetivo realizar uma síntese dos estudos com reabilitação vestibular, focados em outras morbidades além das vestibulopatias, indicando as tendências de investigações e os principais resultados, principalmente de intervenções, em diferentes situações. Para isso foi realizado um mapeamento dos estudos relacionados ao tema nas bases de dados Lilacs, Science Direct e Scielo sendo selecionados 13 artigos para análise. Os estudos encontrados utilizaram a reabilitação vestibular no tratamento de diferentes problemas de origem neuro-motora e psicológica. A reabilitação vestibular mostrou-se efetiva para morbidades como o Parkinson, a ansiedade e a depressão. Além disso, esteve associada a melhorias na qualidade de vida nos aspectos físico, emocional e funcional e, principalmente, à melhoria dos equilíbrios estático e dinâmico bem como à diminuição das quedas.

  15. Betahistine treatment improves the recovery of static symptoms in patients with unilateral vestibular loss.

    Science.gov (United States)

    Redon, Christine; Lopez, Christophe; Bernard-Demanze, Laurence; Dumitrescu, Michel; Magnan, Jacques; Lacour, Michel; Borel, Liliane

    2011-04-01

    Vestibular loss induces a combination of postural, oculomotor, and perceptive symptoms that are compensated over time. The aim of this study was to analyze the influence of betahistine dihydrochloride on vestibular compensation. A randomized, double-blind, placebo-controlled study was performed in Menière's disease patients who underwent a curative unilateral vestibular neurotomy (UVN). The effects of betahistine treatment were investigated on a broad spectrum of vestibular-induced changes resulting from vestibular loss: body sway, head orientation, ocular cyclotorsion, spontaneous nystagmus, verticality perception, and self-evaluation of the postural stability. The time course of the recovery was compared in 16 patients who received either a placebo or betahistine (24 mg b.i.d.) from 3 days up to 3 months after UVN. Patients were examined before (day -1) and after UVN (days 7, 30, and 90). Results indicate that betahistine reduces the time to recovery by 1 month or more depending on the tested functions. Betahistine was effective as soon as 4 days after treatment administration, and the effect remained during the whole compensation period (up to 3 months). The observed clinical effects may be attributed to an action of betahistine in rebalancing the neuronal activity between contralateral vestibular nuclei. PMID:20940335

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

    Directory of Open Access Journals (Sweden)

    Hsieh LC

    2014-09-01

    Full Text Available Li-Chun Hsieh,1,2 Hung-Ching Lin,2,3 Guo-She Lee4,5 1Institute of Brain Science, School of Medicine, National Yang-Ming University, Taipei, Taiwan; 2Department of Otolaryngology, Mackay Memorial Hospital, Taipei, Taiwan; 3Department of Audiology and Speech Language Pathology, Mackay Memorial Medical College, Taipei, Taiwan; 4Faculty of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan; 5Department of Otolaryngology, Taipei City Hospital, Ren-Ai Branch, Taipei, Taiwan Background: Imbalance from degeneration of vestibular end organs is a common problem in the elderly. However, the decline of vestibular function with aging was revealed in few vestibular function tests such as vestibular autorotation test (VAT. In the current VAT, there are drawbacks of poor test–retest reliability, slippage of the sensor at high-speed rotations, and limited data about the effect of aging. We developed a correlational-VAT (cVAT system that included a small, light sensor (less than 20 g with wireless data transmission technique to evaluate the aging of vestibular function. Material and methods: We enrolled 53 healthy participants aged between 25 and 75 years and divided them into five age groups. The test conditions were vertical and horizontal head autorotations of frequencies from 0 to 3 Hz with closed eyes or open eyes. The cross-correlation coefficient (CCC between eye velocity and head velocity was obtained for the head autorotations between 1 Hz and 3 Hz. The mean of the CCCs was used to represent the vestibular function. Results: Age was significantly and negatively correlated with the mean CCC for all test conditions, including horizontal or vertical autorotations with open eyes or closed eyes (P<0.05. The mean CCC with open eyes declined significantly at 55–65 years old and the mean CCC with closed eyes declined significantly at 65–75 years old.Conclusion: Vestibular function evaluated using mean CCC revealed a decline with age, and the function of visual-vestibulo-ocular reflex declined 10 years earlier than the function of vestibulo-ocular reflex. Keywords: vestibular autorotation test, aging, correlation analysis, gyrometry, electro-oculography

  17. The origins of vestibular science.

    Science.gov (United States)

    Wiest, Gerald

    2015-04-01

    The vestibular system conveys information about body motion and gravity. It was one of the first sensory systems to emerge in evolution; however, it was also the last to be discovered. The causal relationship between diseases of the ear and the symptom of vertigo was not recognized until the mid-19th century. Only a few years later, the basic principle of semicircular canal function was elucidated almost simultaneously by three scientists with completely different backgrounds. This historical review describes the major milestones in the discoveries of the anatomy and the physiology of the vestibular system that paved the way for the establishment of neurotology as a clinical subspecialty. PMID:25766734

  18. Afferent diversity and the organization of central vestibular pathways.

    Science.gov (United States)

    Goldberg, J M

    2000-02-01

    This review considers whether the vestibular system includes separate populations of sensory axons innervating individual organs and giving rise to distinct central pathways. There is a variability in the discharge properties of afferents supplying each organ. Discharge regularity provides a marker for this diversity since fibers which differ in this way also differ in many other properties. Postspike recovery of excitability determines the discharge regularity of an afferent and its sensitivity to depolarizing inputs. Sensitivity is small in regularly discharging afferents and large in irregularly discharging afferents. The enhanced sensitivity of irregular fibers explains their larger responses to sensory inputs, to efferent activation, and to externally applied galvanic currents, but not their distinctive response dynamics. Morphophysiological studies show that regular and irregular afferents innervate overlapping regions of the vestibular nuclei. Intracellular recordings of EPSPs reveal that some secondary vestibular neurons receive a restricted input from regular or irregular afferents, but that most such neurons receive a mixed input from both kinds of afferents. Anodal currents delivered to the labyrinth can result in a selective and reversible silencing of irregular afferents. Such a functional ablation can provide estimates of the relative contributions of regular and irregular inputs to a central neuron's discharge. From such estimates it is concluded that secondary neurons need not resemble their afferent inputs in discharge regularity or response dynamics. Several suggestions are made as to the potentially distinctive contributions made by regular and irregular afferents: (1) Reflecting their response dynamics, regular and irregular afferents could compensate for differences in the dynamic loads of various reflexes or of individual reflexes in different parts of their frequency range; (2) The gating of irregular inputs to secondary VOR neurons could modify the operation of reflexes under varying behavioral circumstances; (3) Two-dimensional sensitivity can arise from the convergence onto secondary neurons of otolith inputs differing in their directional properties and response dynamics; (4) Calyx afferents have relatively low gains when compared with irregular dimorphic afferents. This could serve to expand the stimulus range over which the response of calyx afferents remains linear, while at the same time preserving the other features peculiar to irregular afferents. Among those features are phasic response dynamics and large responses to efferent activation; (5) Because of the convergence of several afferents onto each secondary neuron, information transmission to the latter depends on the gain of individual afferents, but not on their discharge regularity. PMID:10706428

  19. Action mechanism of betahistine in the vestibular end organs.

    Science.gov (United States)

    Chávez, H; Vega, R; Valli, P; Mira, E; Benvenuti, C; Guth, P S; Soto, E

    2001-06-01

    Betahistine has been used to treat several vestibular disorders of both central and peripheral origin. The objective of this work was to study the betahistine action mechanism at the vestibular end organs. Experiments were carried out in wild larval axolotl (Ambystoma tigrinum). Multiunit extracellular recordings were obtained from the semicircular canal nerve using a suction electrode. Betahistine (10 microM to 10 mM, n = 32) inhibited the basal spike discharge of the vestibular afferent neurons with an IC50 of 600 microM. To define the site of action of betahistine, its interactions with antagonists of nitric oxide sintethizing enzyme, cholinergic drugs, and excitatory amino acids were studied. Betahistine 1 mM (n = 5) was coadministered with NG-nitro-L-arginine 3 microM. The action of betahistine remained as in control experiments. Betahistine 1 mM reduced the excitatory action of carbachol (200 microM, n = 5) in a 30 +/- 3.4%. Cholinergic antagonists atropine (10 microM, n = 3) and d-tubocurarine (10 microM, n = 3) did not modify betahistine actions. Betahistine 1 mM also reduced kainic acid (10 microM, n = 4) excitatory action in 45.5 +/- 9.8%. These results corroborate that betahistine has a peripheral inhibitory action in the spike discharge of the afferent neurons in the vestibule. This action seems to involve neither NO production nor modifications in the release of acetylcholine from the efferent fibers. The inhibitory action of betahistine seems to be due to a postsynaptic binding site on the afferent neurons. PMID:11677837

  20. Effects of Visceral Inputs on the Processing of Labyrinthine Signals by the Inferior and Caudal Medial Vestibular Nuclei: Ramifications for the Production of Motion Sickness

    Science.gov (United States)

    Arshian, Milad S.; Puterbaugh, Sonya R.; Miller, Daniel J.; Catanzaro, Michael F.; Hobson, Candace E.; McCall, Andrew A.; Yates, Bill J.

    2013-01-01

    Neurons located in the caudal aspect of the vestibular nucleus complex have been shown to receive visceral inputs, and project to brainstem regions that participate in generating emesis, such as nucleus tractus solitarius and the “vomiting region” in the lateral tegmental field (LTF). Consequently, it has been hypothesized that neurons in the caudal vestibular nuclei participate in triggering motion sickness, and that visceral inputs to the vestibular nucleus complex can affect motion sickness susceptibility. To obtain supporting evidence for this hypothesis, we determined the effects of intragastric infusion of copper sulfate (CuSO4) on responses of neurons in the inferior and caudal medial vestibular nuclei to rotations in vertical planes. CuSO4 readily elicits nausea and emesis by activating gastrointestinal afferents. Infusion of CuSO4 produced a >30% change in spontaneous firing rate of approximately one-third of neurons in the caudal aspect of the vestibular nucleus complex. These changes in firing rate developed over several minutes, presumably in tandem with the emetic response. The gains of responses to vertical vestibular stimulation of a larger fraction (approximately two-thirds) of caudal vestibular nucleus neurons were altered over 30% by administration of copper sulfate. The response gains of some units went up, and others went down, and there was no significant relationship with concurrent spontaneous firing rate change. These findings support the notion that the effects of visceral inputs on motion sickness susceptibility are mediated in part through the caudal vestibular nuclei. However, our previous studies showed that infusion of CuSO4 produced larger changes in responses to vestibular stimulation of LTF neurons, as well as parabrachial nucleus neurons that are believed to participate in generating nausea. Thus, integrative effects of gastrointestinal inputs on the processing of labyrinthine inputs must occur at brain sites that participate in eliciting motion sickness in addition to the caudal vestibular nuclei. It seems likely that the occurrence of motion sickness requires converging inputs to brain areas that generate nausea and vomiting from a variety of regions that process vestibular signals. PMID:23712685

  1. The vestibular implant: Quo vadis?

    Directory of Open Access Journals (Sweden)

    RaymondVan De Berg

    2011-08-01

    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.

  2. Surgical Procedures for Vestibular Dysfunction

    Science.gov (United States)

    ... from the parts of the inner ear that sense gravity and motion changes. The hearing organ (cochlea) is also sacrificed with this procedure. Vestibular ... to the ear to destroy the balance end organs so that the brain no longer receives ... gravity and motion changes. Cochlear dialysis Cochlear dialysis ...

  3. Stereotactic radiotherapy for vestibular schwannoma

    DEFF Research Database (Denmark)

    Muzevic, Dario; Legcevic, Jelena

    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 resection or any other possible treatment or combination of treatments in patients with a cerebellopontine angle tumour up to 3 cm in diameter, presumed to be a vestibular schwannoma. DATA COLLECTION AND ANALYSIS: We used the standard methodological procedures expected by The Cochrane Collaboration. MAIN RESULTS: No studies met the inclusion criteria for this review. AUTHORS' CONCLUSIONS: There is no high quality evidence in the literature from RCTs to determine whether stereotactic radiotherapy is better than microsurgical resection or observation alone for patients with a vestibular schwannoma. In the absence of such evidence, the treatment method should be chosen on an individual basis, taking into consideration the patient's preferences, clinician experience and the availability of radiotherapeutic equipment. With the growing availability of radiotherapeutic equipment, randomised controlled trials should be undertaken to evaluate the role of stereotactic radiotherapy in comparison with other treatment options.

  4. Vestibular Findings in Military Band Musicians

    Scientific Electronic Library Online (English)

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

    2014-04-01

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

  5. Changes in TNF?, NF?B and MnSOD protein in the vestibular nuclei after unilateral vestibular deafferentation

    Directory of Open Access Journals (Sweden)

    Lacour Michel

    2010-12-01

    Full Text Available Abstract Background Unilateral vestibular deafferentation results in strong microglial and astroglial activation in the vestibular nuclei (VN that could be due to an inflammatory response. This study was aimed at determining if markers of inflammation are upregulated in the VN after chemical unilateral labyrinthectomy (UL in the rat, and if the inflammatory response, if any, induces the expression of neuroprotective factors that could promote the plasticity mechanisms involved in the vestibular compensation process. The expressions of inflammatory and neuroprotective factors after chemical or mechanical UL were also compared to verify that the inflammatory response was not due to the toxicity of sodium arsanilate. Methods Immunohistological investigations combined the labeling of tumor necrosis factor ? (TNF?, as a marker of the VN inflammatory response, and of nuclear transcription factor ?B (NF?B and manganese superoxide dismutase (MnSOD, as markers of neuroprotection that could be expressed in the VN because of inflammation. Immunoreactivity (Ir of the VN cells was quantified in the VN complex of rats. Behavioral investigations were performed to assess the functional recovery process, including both static (support surface and dynamic (air-righting and landing reflexes postural tests. Results Chemical UL (arsanilate transtympanic injection induced a significant increase in the number of TNF?-Ir cells in the medial and inferior VN on both sides. These changes were detectable as early as 4 h after vestibular lesion, persisted at 1 day, and regained nearly normal values at 3 days. The early increase in TNF? expression was followed by a slightly delayed upregulation of NF?B 8 h after chemical UL, peaking at 1 day, and regaining control values 3 days later. By contrast, upregulation of MnSOD was more strongly delayed (1 day, with a peak at 3 days, and a return to control values at 15 days. Similar changes of TNF?, NF?B, and MnSOD expression were found in rats submitted to mechanical UL. Behavioral observations showed strong posturo-locomotor deficits early after chemical UL (1 day and a complete functional recovery 6 weeks later. Conclusions Our results suggest that the upregulation of inflammatory and neuroprotective factors after vestibular deafferentation in the VN may constitute a favorable neuronal environment for the vestibular compensation process.

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

    OpenAIRE

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

    2012-01-01

    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 mov...

  7. Vestibular rehabilitation in elderly patients with central vestibular dysfunction: a prospective, randomized pilot study

    OpenAIRE

    Marioni, Gino; Fermo, Salvatore; Lionello, Marco; Fasanaro, Elena; Giacomelli, Luciano; Zanon, Stefania; Staffieri, Claudia; Dall’igna, Franco; Manzato, Enzo; Staffieri, Alberto

    2012-01-01

    For the vestibular system, aging is associated with degenerated otoconia and loss of hair cells, vestibular afferents, and cells in the vestibular nuclei. Further neurodegenerative processes involve cortical, extrapyramidal motor, and cerebellar structures. Dizziness is quite common in the elderly, limiting their mobility and activities. The role of vestibular rehabilitation in these patients is controversial. The present prospective, randomized, preliminary investigation aimed to compare the...

  8. Evaluation of tests for vestibular function

    Science.gov (United States)

    1992-01-01

    Vestibular testing methodologies are examined in terms of their clinical value and applicability to the assessment of astronaut candidates and human responses to microgravity. Classical and novel testing approaches are examined in terms of nine functions such as otolith organs, vestibular neural processing, and ocular motor systems. The tests reviewed include the basic vestibular-function test battery, postural stability testing, visual-vestibular interaction, reactions to off-axis rotation, and vestibular evoked responses. The basic test battery is shown to be essential for astronaut and inertial-environment baseline-data evaluations, whereas the newer and research tests are only recommended in special cases. Stimulus rearrangement and motion-sickness tests are indicated for testing adaptation to inertial environments. Postural stability and visual-vestibular interaction are recommended for evaluating one's suitability for being an astronaut.

  9. Personality changes in patients with vestibular dysfunction

    OpenAIRE

    PaulSmith

    2013-01-01

    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 reflex...

  10. Current Treatment Options in Vestibular Migraine

    OpenAIRE

    Obermann, Mark; Strupp, Michael

    2014-01-01

    Approximately 1% of the general population in western industrialized countries suffers from vestibular migraine. However, it remains widely unknown and often under diagnosed despite the recently published diagnostic criteria for vestibular migraine. Treatment trials that specialize on vestibular migraine are scarce and systematic randomized controlled clinical trials are now only emerging. This review summarizes the knowledge on the currently available treatment options that were tested speci...

  11. Personality Changes in Patients with Vestibular Dysfunction

    Directory of Open Access Journals (Sweden)

    PaulSmith

    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.

  12. Fast-Growing Vestibular Schwannoma

    OpenAIRE

    Falcioni, Maurizio; Taibah, Abdelkader; Donato, Giuseppe; Piccirillo, Enrico; Russo, Alessandra; Sanna, Mario

    2000-01-01

    A case of a Jehovah's witness affected by an intracanalicular vestibular schwannoma with an extremely fast growth rate is presented. Nine months after presentation, the tumor reached 23 mm in the cerebellopontine angle. A partial removal through a retrosigmoid approach was planned. Because of the presence of a dominant high jugular bulb masquering the internal auditory canal, the intracanalicular portion of the tumor was left in place. The residual tumor grew 12 mm in 2 months. Even after a g...

  13. Projection neurons of the vestibulo-sympathetic reflex pathway.

    Science.gov (United States)

    Holstein, Gay R; Friedrich, Victor L; Martinelli, Giorgio P

    2014-06-15

    Changes in head position and posture are detected by the vestibular system and are normally followed by rapid modifications in blood pressure. These compensatory adjustments, which allow humans to stand up without fainting, are mediated by integration of vestibular system pathways with blood pressure control centers in the ventrolateral medulla. Orthostatic hypotension can reflect altered activity of this neural circuitry. Vestibular sensory input to the vestibulo-sympathetic pathway terminates on cells in the vestibular nuclear complex, which in turn project to brainstem sites involved in the regulation of cardiovascular activity, including the rostral and caudal ventrolateral medullary regions (RVLM and CVLM, respectively). In the present study, sinusoidal galvanic vestibular stimulation was used to activate this pathway, and activated neurons were identified through detection of c-Fos protein. The retrograde tracer Fluoro-Gold was injected into the RVLM or CVLM of these animals, and immunofluorescence studies of vestibular neurons were conducted to visualize c-Fos protein and Fluoro-Gold concomitantly. We observed activated projection neurons of the vestibulo-sympathetic reflex pathway in the caudal half of the spinal, medial, and parvocellular medial vestibular nuclei. Approximately two-thirds of the cells were ipsilateral to Fluoro-Gold injection sites in both the RVLM and CVLM, and the remainder were contralateral. As a group, cells projecting to the RVLM were located slightly rostral to those with terminals in the CVLM. Individual activated projection neurons were multipolar, globular, or fusiform in shape. This study provides the first direct demonstration of the central vestibular neurons that mediate the vestibulo-sympathetic reflex. PMID:24323841

  14. 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 treatment strategy based on the natural history of tumor growth and hearing also is discussed.

  15. Multimodal integration of self-motion cues in the vestibular system: active versus passive translations.

    Science.gov (United States)

    Carriot, Jerome; Brooks, Jessica X; Cullen, Kathleen E

    2013-12-11

    The ability to keep track of where we are going as we navigate through our environment requires knowledge of our ongoing location and orientation. In response to passively applied motion, the otolith organs of the vestibular system encode changes in the velocity and direction of linear self-motion (i.e., heading). When self-motion is voluntarily generated, proprioceptive and motor efference copy information is also available to contribute to the brain's internal representation of current heading direction and speed. However to date, how the brain integrates these extra-vestibular cues with otolith signals during active linear self-motion remains unknown. Here, to address this question, we compared the responses of macaque vestibular neurons during active and passive translations. Single-unit recordings were made from a subgroup of neurons at the first central stage of sensory processing in the vestibular pathways involved in postural control and the computation of self-motion perception. Neurons responded far less robustly to otolith stimulation during self-generated than passive head translations. Yet, the mechanism underlying the marked cancellation of otolith signals did not affect other characteristics of neuronal responses (i.e., baseline firing rate, tuning ratio, orientation of maximal sensitivity vector). Transiently applied perturbations during active motion further established that an otolith cancellation signal was only gated in conditions where proprioceptive sensory feedback matched the motor-based expectation. Together our results have important implications for understanding the brain's ability to ensure accurate postural and motor control, as well as perceptual stability, during active self-motion. PMID:24336720

  16. Special (vestibular training of servicemen

    Directory of Open Access Journals (Sweden)

    Afonin V.M.

    2011-02-01

    Full Text Available It has been shown that conditions of professional activity of airmobile servicemen require from them, in addition to excellent proficiency in military armament and materiel, high level of physical qualities and movement coordination development. It is essential to have high practice of vestibular apparatus, which helps to resist such negative feature as air sickness. The essences of term air sickness, its negative consequences for professional activity are highlighted. Possible tendencies of work in terms of enhancing organism resistance to air sickness (according to the analysis of publications and practical experience are investigated.

  17. The Anatomical and Physiological Framework for Vestibular Prostheses

    OpenAIRE

    Highstein, Stephen M.; Holstein, Gay R.

    2012-01-01

    This article reviews the structure function of the vestibular system and its pathology with respect to requirements for the design and construction of a functional vestibular prosthesis. The ultimate goal of a vestibular prosthesis is to restore balance and equilibrium through direct activation of vestibular nerve fibers. An overview of the peripheral and central vestibular systems that highlights their most important functional aspects re: the design of a prosthesis is provided. Namely, the ...

  18. Role of the commissural inhibitory system in vestibular compensation in the rat.

    Science.gov (United States)

    Bergquist, Filip; Ludwig, Mike; Dutia, Mayank B

    2008-09-15

    We investigated the role of the vestibular commissural inhibitory system in vestibular compensation (VC, the behavioural recovery that follows unilateral vestibular loss), using in vivo microdialysis to measure GABA levels in the bilateral medial vestibular nucleus (MVN) at various times after unilateral labyrinthectomy (UL). Immediately after UL, in close correlation with the appearance of the characteristic oculomotor and postural symptoms, there is a marked increase in GABA release in the ipsi-lesional MVN. This is not prevented by bilateral flocculectomy, indicating that it is due to hyperactivity of vestibular commissural inhibitory neurones. Over the following 96 h, as VC occurs and the behavioural symptoms ameliorate, the ipsi-lesional GABA levels return to near-normal. Contra-lesional GABA levels do not change significantly in the initial stages of VC, but decrease at late stages so that when static symptoms have abated there remains a significant difference between the MVNs of the two sides. We also investigated the role of the commissural inhibition in Bechterew's phenomenon, by reversibly inactivating the intact contra-lesional labyrinth in compensating animals through superfusion of local anaesthetic on the round window. Transient inactivation of the intact labyrinth elicited the lateralized behaviour described by Bechterew, but did not alter the GABA levels in either MVN, suggesting the involvement of distinct cellular mechanisms. These findings indicate that an imbalanced commissural inhibitory system is a root cause of the severe oculomotor and postural symptoms of unilateral vestibular loss, and that re-balancing of commissural inhibition occurs in parallel with the subsequent behavioural recovery during VC. PMID:18635647

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

  20. Retrograde tracing of medial vestibular nuclei connections to the kidney in mice.

    Science.gov (United States)

    Hao, Yan; Tian, Xue-Bi; Liu, Cheng; Xiang, Hong-Bing

    2014-01-01

    Vestibular nuclei have been identified as a uniform multifunctional structure in order to maintain physiological homeostasis, including the participation of renal sympathetic activity. In this study, the medial vestibular nuclei (MVe) of 10 adult male C57BL/6J strain mice were mapped retrograde using injections of pseudorabies virus (PRV)-614. The virus, injected into the kidney, was specifically transported to the medial vestibular nuclei (MVe). We used a fluorescence immunohistochemistry to characterize the chemical neuroanatomical substrate of MVe innervating the kidney in the mouse. At five days after PRV-614 injection in the kidney, PRV-614 infected neurons were retrogradely labeled in MVeMC and MVePC; PRV-614/tyrosine hydroxylase (TH) double-labeled neurons located predominantly in MVeMC and not in MVePC, whereas PRV-614/tryptophan hydroxylase (TPH) neurons were not localized in MVeMC and MVePC. Our results revealed direct neuroanatomical evidence to identify catecholaminergic projections from the MVeMC to the kidney, suggesting that medial vestibulo-renal pathway may be catecholaminergic. PMID:25197422

  1. Restoration of 3D Vestibular Sensation in Rhesus Monkeys Using a Multichannel Vestibular Prosthesis

    OpenAIRE

    Dai, Chenkai; FRIDMAN, GENE Y.; Davidovics, Natan; Chiang, Bryce; Ahn, Joong Ho; DELLA SANTINA, CHARLES C.

    2011-01-01

    Profound bilateral loss of vestibular hair cell function can cause chronically disabling loss of balance and inability to maintain stable vision during head and body movements. We have previously shown that chinchillas rendered bilaterally vestibular-deficient via intratympanic administration of the ototoxic antibiotic gentamicin regain a more nearly normal 3-dimensional vestibulo-ocular reflex (3D VOR) when head motion information sensed by a head-mounted multichannel vestibular prosthesis (...

  2. Electrical Stimulation to Restore Vestibular Function – Development of a 3-D Vestibular Prosthesis

    OpenAIRE

    DELLA SANTINA, CHARLES C.; Migliaccio, Americo A; Patel, Amit H.

    2005-01-01

    Patients who fail to compensate for bilateral loss of vestibular sensory function are disabled by disequilibrium and illusory movement of the visual field during head movement. An implantable prosthesis that restores vestibular sensation could significantly improve quality of life for these patients. To be effective, such a device should encode head rotation in all 3 dimensions. We describe the 3-dimensional angular vestibulo-ocular reflex of normal chinchillas and vestibular-deficient chinch...

  3. Vestibular function and quality of life in vestibular schwannoma: does size matter?

    Directory of Open Access Journals (Sweden)

    JudithWagner

    2011-08-01

    Conclusions. Loss of vestibular function in vestibular schwannoma clearly correlates with tumor size. However, loss of vestibular function was not strictly associated with a long-term deterioration of quality of life. This may be due to central compensation of vestibular deficits in long-standing large tumors. Loss of hearing before treatment was significantly influenced by the age of the patient but not by tumor size. At follow-up 1 and 2, hearing was significantly worse in those patients with a large VS and after microsurgical treatment.

  4. [Vestibular schwannoma: a case report of misdiagnosis].

    Science.gov (United States)

    You, Huizeng; Li, Xiaoying; Wang, Wuqing

    2014-11-01

    Vestibular schwannoma is a rare tumor, which is easily misdiagnosed. The authors presented a case of vestibular schwannoma in a 36-year-old woman. The clinical manifestations were recurrent vertigo, hearing loss of the left ear, and tinnitus. The pure tone audiometry threshold of the left ear was 45dBHL with air conduction, and 33 dBHL with bone conduction. A CT scan of the temporal bone region didn't show any abnormal finding. A MRI scan of the head showed nodule abnormal signal in the internal of left vestibular and the narrow of perilymphaticum gap in T2W1 + T2Flair. The initial diagnosis was Meniere's disease. And the post-operation pathologic diagnosis was vestibular schwannoma. PMID:25752127

  5. Recovery of vestibular ocular reflex function and balance control after a unilateral peripheral vestibular deficit.

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    JohnAllum

    2012-05-01

    Full Text Available This review describes the effect of unilateral peripheral vestibular deficit (UPVD on balance control as observed in stance and gait tests. Normally, a UPVD is defined based on vestibular ocular reflex (VOR function. Therefore, we compare recovery observed in balance control over time with similar patterns of recovery or lack thereof in VOR function. Three types of UPVD are considered; acute vestibular neuritis, vestibular loss prior to and after cerebellar pontine angle tumor (CPAT surgery during which a vestibular neurectomy was performed, and vestibular loss following neurectomy to eliminate disabling Ménière’s disease. To measure balance control, body-worn gyroscopes, mounted near the body’s centre of mass, were used for stance and gait tests. Measurement variables were the pitch (anterior-posterior and roll (lateral sway angles and angular velocities of the lower trunk-pelvis. All three groups showed balance deficits during stance tasks on foam, especially with eyes closed when stable control is highly dependent on vestibular inputs. Deficits in balance control during gait were present but were more profound for complex gait tasks such as tandem gait. Differences emerged between the groups concerning the severity of the deficit and its recovery. Generally, the effects of acute neuritis were more severe but recovered rapidly, deficits due to vestibular neurectomy were less severe but longer lasting. These results paralleled deficits in VOR function and raise questions about two modes of neural plasticity occurring in the vestibular system following vestibular loss: one mode being the limited central compensation for the loss, and the second mode being some restoration of peripheral vestibular function. Future work will need to correlate deficits in balance control during stance and gait more exactly with VOR deficits and carefully consider the differences between insufficient central compensation compared to inadequate peripheral restoration of function.

  6. Vestibular-visual interactions in flight simulators

    Science.gov (United States)

    Clark, B.

    1977-01-01

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

  7. STANDARDIZATION OF VESTIBULAR EVOKED MYOGENIC POTENTIALS

    OpenAIRE

    Ufuk Derinsu; Elmira ?sgenderova Ba?; Ferda Akda?

    2009-01-01

    Objectives: The purpose of this study is to determine the normative data for vestibular-evoked myogenic potentials (VEMP ) to use in differential diagnosis.Materials and Methods: We recorded vestibular-evoked myogenic potentials in 32 voluntaries (16 men and 16 women). Electrodes were placed as 1-channel montage: active electrode to the midpoint of the ipsilateral Sternocleidomastoid muscle (SCM), referance electrode to the lower part of the ipsilateral SCM and ground electrode to the forehea...

  8. Outcome analysis of individualized vestibular rehabilitation protocols

    Science.gov (United States)

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

    2000-01-01

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

  9. RECORDING OF VESTIBULAR EVOKED MYOGENIC POTENTIALS

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    A. A. Sazgar

    2006-05-01

    Full Text Available It has been shown recently that loud clicks evoke myogenic potentials in the tonically contracting sternocleidomastoid muscles. Studies have suggested that these potentials are of vestibular origin, especially of the saccule and inferior vestibular nerve. A pilot study was undertaken in our hospital to record vestibular evoked myogenic potentials (VEMP for the first time in Iran. Eighteen healthy volunteers (32 ears without history of otologic or vestibular disorders were subjected to the VEMP test. Twenty-one patients (26 ears with unilateral (6 patients and bilateral (5 patients high frequency sensorineural hearing loss with unknown etiology, acoustic neuroma (1 patient, Meniere’s disease (4 patients and unilateral low frequency sensorineural hearing loss without vestibular complaint (5 patients were also enrolled in this study. VEMP response to clicks was obtained from 84.4% of ears of healthy subjects. These subjects demonstrated short latency waves to click stimuli during tonic neck flexor activation. Mean latencies of first positive (p13 and first negative (n23 potentials in healthy subjects were 12.45 ± 1.9 ms and 20.8 ± 3.5 ms, respectively. Median latencies of these two potentials were 12.1 and 19.3 ms, respectively. We could record VEMP in 5 patients with unilateral and all patients with high and low frequency sensorineural hearing loss without vestibular complaint. In the patient with acoustic neuroma VEMP was absent on the affected side. This technique may offer a new method to evaluate otolith and sacculocollic pathways in human.

  10. Achados vestibulares em pacientes portadores de fibromialgia

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    Zeigelboim, Bianca Simone

    2011-07-01

    Full Text Available Introdução: A fibromialgia (FM é uma síndrome musculoesquelética não inflamatória, de caráter crônico, de etiologia desconhecida, caracterizada por dor difusa, aumento da sensibilidade na palpação e por sintomas como fadiga, insônia, ansiedade, depressão, intolerância ao frio e queixas otológicas. Objetivo: Avaliar o comportamento vestibular em pacientes portadores de fibromialgia. Método: Foi realizado um estudo retrospectivo de corte transversal. Avaliaram-se 25 pacientes na faixa etária entre 26 e 65 anos (média de idade - 52,2 anos e desvio padrão - 10,3 anos, submetidos aos seguintes procedimentos: anamnese, avaliação otorrinolaringológica e vestibular por meio da vectoeletronistagmografia. Resultados: a Os sintomas otoneurológicos mais evidenciados foram: dificuldade ou dor ao movimento do pescoço e dor irradiada para ombro ou braço (92,0% em cada, tontura (84,0% e cefaleia (76,0%. Os sintomas clínicos diversos mais relatados foram: depressão (80,0%, ansiedade (76,0% e insônia (72,0%; b O exame vestibular esteve alterado em 12 pacientes (48,0% sendo localizado na prova calórica; c Houve prevalência de alteração no sistema vestibular periférico e, d Houve predomínio das disfunções vestibulares periféricas deficitárias. Conclusão: Este estudo permitiu verificar a importância do exame labiríntico o que ressalta que esse tipo de população deveria ser melhor estudada, uma vez que diversas doenças reumatológicas pelas suas manifestações e áreas de comprometimento podem gerar alterações vestibulares importantes.

  11. Reabilitação vestibular em idosos com tontura / Vestibular rehabilitation in elderly patients with dizziness

    Scientific Electronic Library Online (English)

    Francisco Halilla, Zanardini; Bianca Simone, Zeigelboim; Ari Leon, Jurkiewicz; Jair Mendes, Marques; Jackeline, Martins-Bassetto.

    2007-06-01

    Full Text Available TEMA: o envelhecimento populacional é um processo natural, manifesta-se por um declínio das funções de diversos órgãos. A reabilitação vestibular (RV) é um processo terapêutico que visa promover a redução significativa dos sintomas labirínticos. OBJETIVO: verificar os benefícios dos exercícios de RV [...] por meio da avaliação pré e pós-aplicação do questionário Dizziness Handicap Inventory (DHI) - adaptação brasileira. MÉTODO: participaram deste estudo oito idosos com queixa de tontura, na faixa etária de 63 a 82 anos, três do sexo masculino e cinco do sexo feminino. Realizaram-se os seguintes procedimentos: anamnese, inspeção otológica, avaliação vestibular por meio da vectoeletronistagmografia (VENG), aplicação do questionário DHI e dos exercícios de RV de Cawthorne (1944) e Cooksey (1946). RESULTADOS: com relação as queixas auditivas e vestibulares, observou-se a incidência do zumbido, da hipoacusia, da vertigem postural e do desequilíbrio; na avaliação da função vestibular, constataram-se alterações em todos os idosos; as alterações foram na sua maioria na prova calórica com predomínio da hiporreflexia uni e bilateral; constataram-se, no exame vestibular, três casos de síndrome vestibular periférica deficitária unilateral, três casos de síndrome vestibular periférica deficitária bilateral, um caso de síndrome vestibular central deficitária bilateral e um caso de síndrome vestibular central irritativa bilateral; houve melhora significativa dos aspectos físico (p = 0,00413), funcional (p = 0,00006) e emocional (p = 0,03268) após a realização dos exercícios de RV. CONCLUSÃO: o protocolo utilizado de RV promoveu melhora na qualidade de vida dos idosos e auxiliou no processo de compensação vestibular. Abstract in english BACKGROND: the aging of the population is a natural process and is manifested by a decline in the functions of several organs. Vestibular rehabilitation (VR) is a therapeutic process that seeks to promote a significant reduction in the symptoms of the labyrinth. AIM: to verify the benefits of VR exe [...] rcises through the application of the Dizziness Handicap Inventory (DHI) questionnaire - Brazilian version - pre and post rehabilitation. METHOD: participants of this study were eight elderly patients with dizziness, ages between 63 and 82 years, three male and five female. The following procedures were carried out: medical history, otologic inspection, vestibular evaluation with vectoelectronystagmography (VENG), application of the DHI questionnaire and of the Cawthorne (1944) and Cooksey (1946) VR exercises. RESULTS: regarding the auditory and vestibular complaints which were referred to in the medical history, the following was observed: presence of tinnitus, hearing loss, postural vertigo and of unbalance. In the evaluation of the vestibular function alterations were observed for all of the participants, mainly in the caloric test, with a prevalence of unilateral and bilateral hypofunction. In the vestibular exam the following was observed: three cases of unilateral peripheral vestibular deficit syndrome, three cases of bilateral peripheral vestibular deficit syndrome, one case of bilateral central vestibular deficit syndrome and one case of irritating bilateral central vestibular syndrome. There was a statistically significant improvement of the following aspects after VR: physical (p=0.00413), functional (p=0.00006) and emotional (p=0.03268). CONCLUSION: the VR protocol favored the improvement of life quality of the participants and was of assistance in the process of vestibular compensation.

  12. PLC?-activated signalling is essential for TrkB mediated sensory neuron structural plasticity

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    Rocha-Sanchez Sonia M

    2010-10-01

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

  13. Schwannoma vestibular: involução tumoral espontânea / Vestibular Schwannoma: spontaneous tumor involution

    Scientific Electronic Library Online (English)

    Norma de Oliveira, Penido; Rodrigo P., Tangerina; Eduardo Macoto, Kosugi; Carlos Eduardo Cesário de, Abreu; Matheus Brandão, Vasco.

    2007-12-01

    Full Text Available A história natural dos schwannomas vestibulares ainda não está totalmente elucidada, mas sua maioria tende a apresentar crescimento lento, muitos permanecendo sem sintomas durante toda a vida do paciente. Cerca de 69% deste tipo de tumor diagnosticados não apresentam crescimento e, destes, 16% chega [...] m a apresentar regressão tumoral. Considerando os tumores que apresentam crescimento, cerca de 70% crescem menos de 2 mm ao ano. O avanço nos métodos de diagnóstico por imagem, particularmente à ressonância magnética com contraste de gadolínio, permite o diagnóstico cada vez mais de lesões com sintomas mínimos e tamanhos menores. O tratamento de escolha para estes tumores ainda é a ressecção completa do tumor. As técnicas cirúrgicas apresentaram grande avanço nas últimas décadas, o que possibilitou diminuição da mortalidade. Assim, a cirurgia, que antes tinha como objetivo apenas a ressecção completa do tumor, agora visa também à preservação da audição e da função do nervo facial. Considerações finais: Considerando-se sua história natural, abre-se a possibilidade de uma conduta conservadora já que o ritmo de crescimento no primeiro ano após o diagnóstico prediz o comportamento do tumor nos próximos anos. A conduta conservadora não implica em repúdio à cirurgia, devendo ser utilizada em casos de aumento tumoral, piora dos sintomas ou desejo do paciente. Além disso, em relatos de literatura não há diferença estatisticamente significante entre os pacientes submetidos à cirurgia logo após o diagnóstico ou após conduta conservadora inicial, no que diz respeito às seqüelas pós-operatórias. Abstract in english The natural history of Vestibular Schwannomas (VS) is yet not totally known, but most of them have the tendency to slow growth, sometimes without any kind of symptoms during the individual’s entire time. About 69% of diagnosed VS do not grow at all and 16% of these can even regress. Considering tumo [...] rs that grow, about 70% have grown less than 2mm an year. Advanced radiological diagnosis, especially magnetic resonance imaging with gadolinium helps us diagnose small and less symptomatic tumors. Treatment of choice still is complete tumor resection. Surgical approaches have improved considerably and have helped preserve facial nerve function and hearing. Considering VS’s natural history, there is a possibility for conservative treatment for these tumors, because their growth in the first year after diagnosis predicts tumor growth behavior in the next years. Surgery should be done in cases of tumor growth, patient’s desire or symptoms worsening. Moreover, in terms of postoperative sequelae, there is no difference between patients who underwent surgery immediately after diagnosis and those who underwent initial conservative treatment for these tumors.

  14. BETAHISTINE DIHYDROCHLORIDE IN CANINE PERIPHERAL VESTIBULAR SYNDROME DICLORIDRATO DE BETAISTINA NA SÍNDROME VESTIBULAR PERIFÉRICA CANINA

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    Tatiana Champion

    2010-04-01

    Full Text Available Vestibular disease is a common syndrome in small animals that  may resulst of central or peripheral disease. The pathophysiology of peripheral vestibular syndrome is unknown, however it can be related to an abnormal dynamic of endolymphatic fluid or neuritis of the vestibular portion of the VIII cranial nerve.  The recovery of neurological sings is slow and, in chronic cases, the neurological deficits can be irreversible. In veterinary medicine, thera are few medical options to treat this condition, however, in Medicine, betahistine dihydrochloride is used to treat peripheral vestibular disorders. These drug  was used in four dogs with vestibular syndrome. The results showed clinical improvement in 7 to 10 days of treatment and completed recovery in 20 to 30 days, followed by the cure. One year after the treatment, the dogs did not have recurrence of the syndrome. This report shows the use of betahistine dihydrochloride in dogs with peripheral vestibular syndrome, with rapid clinical recover, without laboratorial abnormalities or recurrence of the clinical signs .The results encourage the use of betahistine dihydrochloride in the treatment of  peripheral vestibular disorders in small animals.

    KEY WORDS: Betahistine, dog, vestibular syndrome.
    A síndrome vestibular periférica é uma condição clínica comum em cães. Várias doenças podem causar essa síndrome. Entretanto, sua patofisiologia ainda é pouco conhecida. As alterações clínicas geralmente são autolimitantes, a recuperação pode ser longa e, em casos crônicos, os déficits neurológicos podem ser irreversíveis. Em medicina veterinária, há poucas opções terapêuticas. Na Medicina, o dicloridrato de betaístina é amplamente utilizado. Essa medicação foi empregada em seis cães com síndrome vestibular periférica. Os resultados mostraram melhora clínica com sete a dez dias de tratamento e recuperação quase completa entre vinte e trinta dias. Este trabalho descreve a utilização da betaistina em cães com síndrome vestibular periférica, a rápida melhora clínica e ausência de efeitos adversos. Os resultados obtidos parecem justificar o uso de dicloridrato de betaistina na terapia de distúrbios vestibulares periféricos em animais de companhia.

    PALAVRAS-CHAVES: Betaistina, cão, síndrome vestibular.

  15. A função vestibular em indivíduos usuários de implante coclear / Vestibular function in cochlear implant users

    Scientific Electronic Library Online (English)

    Ariane Solci, Bonucci; Orozimbo Alves, Costa Filho; Luciane Domingues Figueiredo, Mariotto; Regina Célia Bortoleto, Amantini; Kátia de Freitas, Alvarenga.

    2008-04-01

    Full Text Available A ocorrência de alteração no equilíbrio no período pós-cirúrgico ao implante coclear varia de 31 a 75%. OBJETIVO: Analisar a função vestibular no período pré e pós-operatório da cirurgia de implante coclear. MATERIAL E MÉTODO: Avaliou-se a função vestibular, por meio da vectoeletronistagmografia, de [...] 38 pacientes, no pré e pós-cirúrgico de implante coclear. RESULTADOS: A principal queixa de desequilíbrio apresentada pelos pacientes foi a tontura, seguida pela vertigem postural e pela vertigem não-postural. Dos 38 pacientes avaliados, 13% deixaram de apresentar desequilíbrio após a cirurgia de implante coclear e apenas 5% referiram piora. Houve uma melhora na sintomatologia vestibular em 13% dos pacientes, sendo que esta possibilidade pode estar relacionada ao fenômeno de compensação vestibular e pela estimulação elétrica. Entretanto, foi observada na prova calórica uma piora na funcionalidade do sistema vestibular, tanto na orelha implantada como na orelha não-implantada. Assim, não há tendência de maior comprometimento na orelha implantada. CONCLUSÃO: O estudo demonstrou que o implante coclear pode comprometer o sistema vestibular em ambas as orelhas. Entretanto, a sintomatologia vestibular ocorre em menor proporção, podendo haver melhora no desequilíbrio após a cirurgia do implante coclear. Abstract in english Balance alterations in the postoperative of cochlear implant surgeries varies from 31 to 75%. AIM: to analyze vestibular function in the pre and postoperative periods of cochlear implanted individuals. MATERIALS AND METHODS: the vestibular function was assessed, through electronystagmography, in 38 [...] patients, in the pre and postoperative of cochlear implant procedures. RESULTS: The main complaint of unbalance reported by patients was dizziness, followed by postural vertigo and non-postural vertigo. Results: 13% of the patients did not show any balance disorder following cochlear implant surgery and just 5% showed symptoms worsening. 13 % of the patients showed an improvement, and this could be related to the vestibular compensation phenomenon and to electric stimulation. However, it was observed, in the caloric responses, a worsening in the vestibular system function, for both implanted and non-implanted ears. Thus, there is no evidence of more damage to the implanted ear. CONCLUSION: the study showed that cochlear implant surgeries could injure the vestibular system in both ears. However, the vestibular symptoms take place in a smaller proportion, and can improve after cochlear implant surgery.

  16. Comparação de diferentes protocolos de reabilitação vestibular em pacientes com disfunções vestibulares periféricas Comparison of different protocols for vestibular rehabilitation in patients with peripheral vestibular disorders

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    Pâmela Garcia Morozetti

    2011-03-01

    Full Text Available OBJETIVO: Comparar a eficácia terapêutica de dois protocolos de reabilitação vestibular em diferentes disfunções vestibulares. MÉTODOS: Participaram 20 pacientes com disfunções periféricas crônicas, de ambos os gêneros (prevalência do gênero feminino, com 60% da amostra, com média de idade de 55 anos e 9 meses. O Grupo 1 realizou exercícios baseados na estimulação do reflexo vestíbulocular vertical e horizontal, e o Grupo 2 realizou exercícios baseados em um protocolo de reabilitação vestibular personalizado. A análise de dados levou em consideração a queixa durante a anamnese e a evolução clínica do paciente a partir da execução dos exercícios. Além disso, foram obtidos os resultados do questionário Dizziness Handicap Inventory (DHI e da escala analógica e visual de tontura (EVA, pré e pós reabilitação vestibular. RESULTADOS: Houve diferença nos valores da EVA e do DHI (escala física, funcional e no valor total, pré e pós-reabilitação vestibular, em ambos os grupos. Porém, na comparação dos dois grupos no momento pós-reabilitação, o Grupo 2 obteve melhores resultados que o Grupo 1, tanto na EVA quanto no DHI (escala funcional e no valor total. CONCLUSÃO: A reabilitação vestibular possibilitou melhora significativa do quadro otoneurológico clínico e na auto-percepção da tontura independentemente da terapêutica empregada. A reabilitação vestibular personalizada mostrou-se mais eficaz do que o protocolo de estimulação do reflexo vestibulocular na melhora da qualidade de vida de indivíduos com disfunções periféricas crônicasPURPOSE: To compare the therapeutic efficacy of two protocols for vestibular rehabilitation in several vestibular disordes. METHODS: Twenty patients with chronic peripheral disorders of both genders (prevalence of females, with 60% of the sample and mean age of 55 years and 9 months participated in this study. Group 1 carried out exercices based on stimulation of vertical and horizontal vestibulocular reflex, and Group 2 carried out exercices based on a protocol of personalized vestibular rehabilitation. Data analysis considered the complaint manifested during anamnesis and the clinical evolution of the patient during the execution of the exercises. The results obtained from the application of the Dizziness Handicap Inventory questionnaire (DHI and the dizziness visual analog scale (VAS, both before and after vestibular rehabilitation, were also considered in the analysis. RESULTS: Differences were found in the values obtained in VAS and DHI (physical and functional scales and total score, in both groups. However, the comparison of the groups after rehabilitation showed that Group 2 obtained better scores than Group 1, both in VAS and DHI (functional scale and total value. CONCLUSION: Vestibular rehabilitation allowed significant improvement in otoneurological clinical profile and in self-perception of dizziness, regardless the therapeutic method used. Personalized vestibular rehabilitation was more efficient than the vestibulocular reflex stimulation protocol in improving quality of life of individuals with chronic periferal disorders

  17. Comparação de diferentes protocolos de reabilitação vestibular em pacientes com disfunções vestibulares periféricas / Comparison of different protocols for vestibular rehabilitation in patients with peripheral vestibular disorders

    Scientific Electronic Library Online (English)

    Pâmela Garcia, Morozetti; Cristina Freitas, Ganança; Brasília Maria, Chiari.

    2011-03-01

    Full Text Available OBJETIVO: Comparar a eficácia terapêutica de dois protocolos de reabilitação vestibular em diferentes disfunções vestibulares. MÉTODOS: Participaram 20 pacientes com disfunções periféricas crônicas, de ambos os gêneros (prevalência do gênero feminino, com 60% da amostra), com média de idade de 55 an [...] os e 9 meses. O Grupo 1 realizou exercícios baseados na estimulação do reflexo vestíbulocular vertical e horizontal, e o Grupo 2 realizou exercícios baseados em um protocolo de reabilitação vestibular personalizado. A análise de dados levou em consideração a queixa durante a anamnese e a evolução clínica do paciente a partir da execução dos exercícios. Além disso, foram obtidos os resultados do questionário Dizziness Handicap Inventory (DHI) e da escala analógica e visual de tontura (EVA), pré e pós reabilitação vestibular. RESULTADOS: Houve diferença nos valores da EVA e do DHI (escala física, funcional e no valor total), pré e pós-reabilitação vestibular, em ambos os grupos. Porém, na comparação dos dois grupos no momento pós-reabilitação, o Grupo 2 obteve melhores resultados que o Grupo 1, tanto na EVA quanto no DHI (escala funcional e no valor total). CONCLUSÃO: A reabilitação vestibular possibilitou melhora significativa do quadro otoneurológico clínico e na auto-percepção da tontura independentemente da terapêutica empregada. A reabilitação vestibular personalizada mostrou-se mais eficaz do que o protocolo de estimulação do reflexo vestibulocular na melhora da qualidade de vida de indivíduos com disfunções periféricas crônicas Abstract in english PURPOSE: To compare the therapeutic efficacy of two protocols for vestibular rehabilitation in several vestibular disordes. METHODS: Twenty patients with chronic peripheral disorders of both genders (prevalence of females, with 60% of the sample) and mean age of 55 years and 9 months participated in [...] this study. Group 1 carried out exercices based on stimulation of vertical and horizontal vestibulocular reflex, and Group 2 carried out exercices based on a protocol of personalized vestibular rehabilitation. Data analysis considered the complaint manifested during anamnesis and the clinical evolution of the patient during the execution of the exercises. The results obtained from the application of the Dizziness Handicap Inventory questionnaire (DHI) and the dizziness visual analog scale (VAS), both before and after vestibular rehabilitation, were also considered in the analysis. RESULTS: Differences were found in the values obtained in VAS and DHI (physical and functional scales and total score), in both groups. However, the comparison of the groups after rehabilitation showed that Group 2 obtained better scores than Group 1, both in VAS and DHI (functional scale and total value). CONCLUSION: Vestibular rehabilitation allowed significant improvement in otoneurological clinical profile and in self-perception of dizziness, regardless the therapeutic method used. Personalized vestibular rehabilitation was more efficient than the vestibulocular reflex stimulation protocol in improving quality of life of individuals with chronic periferal disorders

  18. Vestibular Ganglion as a Model System of Vital-neural Centre During Embryonic Development

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    A.G. Pillay

    2000-01-01

    Full Text Available Chick embryos at different stages of development till hatching as well as vestibular ganglia of the adult were fixed in formol-saline. Serial sections were stained by Cresyl Fast Violet to analyse the results in the vestibular ganglion. Neurones were categorised and counted. The appearance of a few light cells on Embryonic day 6 (E6 might indirectly indicate the beginning of an early establishment of functional connections in the vestibular ganglion in contrast to most other ganglia studied. The fluctuation in the number of cells during embryonic development may be considered as a normal process for the purpose of re-arrangement for better organisation in order to perform an efficient function. Volume of the vestibular ganglion is the greatest on Embryonic-day 18 (E18 during the whole ontogeny even though its rostro-caudal length is greatest in the adult. This is in contrast to that observed in several other ganglia where the ganglionic volume is the greatest in the adult situation. The reduction or loss of ganglionic neurones in the adult in comparison to that observed on the day of hatching might indicate a functional reduction as a result of ageing process. The appearance of an increased number of tiny cells in the adult in comparison to that observed on the day of hatching is different and peculiar from that observed in other ganglia studied. These new cells are probably derived from active mitoses of reserved neuroblasts. This possibly provides an attempt to replace the inactive / or dead cells during ageing process.

  19. Quality of life of individuals submitted to vestibular rehabilitation / Qualidade de vida de indivíduos submetidos à reabilitação vestibular

    Scientific Electronic Library Online (English)

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

    2009-06-01

    Full Text Available Desordens do equilíbrio comprometem atividades sociais, familiares e profissionais. A reabilitação vestibular pode reduzir o impacto dessas desordens na qualidade de vida dos indivíduos vertiginosos. OBJETIVO: Verificar a influência da reabilitação vestibular sobre a qualidade de vida dos indivíduos [...] , correlacionando-a com gênero, idade, resultado da vectoeletronistagmografia computadorizada e presença de vertigem. Forma de Estudo: Retrospectivo. MATERIAL E MÉTODO: Vinte e dois indivíduos foram submetidos à reabilitação vestibular personalizada e ao Dizziness Handicap Inventory - DHI brasileiro - pré e pós-reabilitação vestibular. Os resultados desse questionário foram correlacionados com as variáveis gênero, idade, avaliação vestibular e presença de tontura do tipo vertigem. RESULTADOS: Todos os escores do DHI diminuíram significantemente após reabilitação vestibular. Não houve diferença entre gêneros; adultos e idosos; síndromes vestibulares periféricas Irritativas, Deficitárias e exames Normais; e presença ou não de vertigem. CONCLUSÃO: Todos os indivíduos obtiveram melhora na qualidade de vida após a reabilitação vestibular personalizada. Abstract in english Balance disorders affect social, family and professional activities. Vestibular rehabilitation can reduce the impact of these disorders on the quality of life of individuals with vertigo. AIM: to study the influence of vestibular rehabilitation on the quality of life of individuals, correlating it w [...] ith gender, age, results from computerized vectoelectronystagmography and vertigo. Study type: Retrospective. MATERIALS AND METHODS:Twenty-two individuals were submitted to customized vestibular rehabilitation and the Brazilian Dizziness Handicap Inventory - DHI before and after vestibular rehabilitation. Results from this questionnaire were correlated with gender, age, vestibular assessment and the presence of vertigo. RESULTS: all the DHI scores reduced significantly after vestibular rehabilitation. There were no differences among genders; adults and elderly patients; irritative peripheral vestibular syndromes; deficiency syndromes and normal exams; the presence or absence of vertigo. CONCLUSION: all the individuals had improvements in their quality of life after customized vestibular rehabilitation.

  20. 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.

  1. 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 (55.5%, empty head sensations, agitation during sleep and depression (51.8% in each one. The vestibular exam showed alterations in 20 patients (74.0% in the caloric test. There was a prevalence of alterations in the peripheral vestibular system. There was a prevalence of deficient peripheral vestibular syndrome. CONCLUSION: the importance of studying the relationship between the vestibular system and temporomandibular joint dysfunction is emphasized, since a high number of alterations in the labyrinthic exam have been noted in this research.

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

    Scientific Electronic Library Online (English)

    Bianca Simone, Zeigelboim; Ari Leon, Jurkiewicz; Jackeline, Martins-Bassetto; Karlin Fabianne, Klagenberg.

    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. Abstract in english 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 (55.5%), empty head sensations, agitation during sleep and depression (51.8%) in each one. The vestibular exam showed alterations in 20 patients (74.0%) in the caloric test. There was a prevalence of alterations in the peripheral vestibular system. There was a prevalence of deficient peripheral vestibular syndrome. CONCLUSION: the importance of studying the relationship between the vestibular system and temporomandibular joint dysfunction is emphasized, since a high number of alterations in the labyrinthic exam have been noted in this research.

  3. Diagnóstico e tratamento das principais síndromes vestibulares / Diagnosis and treatment of the most frequent vestibular syndromes

    Scientific Electronic Library Online (English)

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

    2005-03-01

    Full Text Available Os objetivos deste estudo foram identificar as síndromes vestibulares mais comuns nos ambulatórios de vertigem, suas características clínicas e semiológicas, e observar a resposta ao tratamento específico. Foram estudados retrospectivamente 515 pacientes atendidos em ambulatórios de duas instituiçõe [...] s e avaliados aspectos da anamnese, exame físico e a resposta ao tratamento. As síndromes mais freqüentes foram: vertigem de posicionamento paroxística benigna (VPPB) (28,5%), vertigem postural fóbica (11,5%), vertigem central (10,1%), neurite vestibular (9,7%), doença de Menière (8,5%), enxaqueca (6,4%). Houve boa resposta ao tratamento nos pacientes com enxaqueca (78,8%), VPPB (64%), neurite vestibular (62%), doença de Menière (54,5%) e paroxismia vestibular (54,5%), enquanto pacientes com nistagmo para baixo e vestibulopatia bilateral não tiveram resposta satisfatória (52,6% e 42,8% respectivamente). As síndromes vestibulares foram diagnosticadas através da anamnese e exame físico com testes clínicos específicos para avaliação da função vestibular. A identificação destas síndromes permitiu o tratamento adequado levando a uma boa evolução. Abstract in english The aims of this study were to identify the most common vestibular syndromes in a dizziness unit, and to observe their clinical aspects and response to treatment. Five hundred and fifteen patients were studied retrospectively in two institutions. Aspects of anamnesis, physical examination and the re [...] sponse to treatment were evaluated. The most frequent syndromes were: benign paroxysmal positioning vertigo (VPPB) (28.5%), phobic postural vertigo (11.5%), central vertigo (10.1%), vestibular neuritis (9.7%), Menière disease (8.5%), and migraine (6.4%). A good response to treatment was observed in most patients with migraine (78.8%), VPPB (64%), vestibular neuritis (62%), Menière disease (54.5%) and vestibular paroxismia (54.5%). On the other hand, patients with downbeat nystagmus and bilateral vestibulopathy had poor response (52.6% and 42.8%, respectively). The diagnosis of these most frequent vestibular syndromes were established through anamnesis and physical examination (with specific clinical tests for evaluation of the vestibular function). The correct diagnosis and adequate treatment are important since these syndromes may have a good prognosis.

  4. Diagnóstico e tratamento das principais síndromes vestibulares Diagnosis and treatment of the most frequent vestibular syndromes

    Directory of Open Access Journals (Sweden)

    Aline Mizuta Kozoroski Kanashiro

    2005-03-01

    Full Text Available Os objetivos deste estudo foram identificar as síndromes vestibulares mais comuns nos ambulatórios de vertigem, suas características clínicas e semiológicas, e observar a resposta ao tratamento específico. Foram estudados retrospectivamente 515 pacientes atendidos em ambulatórios de duas instituições e avaliados aspectos da anamnese, exame físico e a resposta ao tratamento. As síndromes mais freqüentes foram: vertigem de posicionamento paroxística benigna (VPPB (28,5%, vertigem postural fóbica (11,5%, vertigem central (10,1%, neurite vestibular (9,7%, doença de Menière (8,5%, enxaqueca (6,4%. Houve boa resposta ao tratamento nos pacientes com enxaqueca (78,8%, VPPB (64%, neurite vestibular (62%, doença de Menière (54,5% e paroxismia vestibular (54,5%, enquanto pacientes com nistagmo para baixo e vestibulopatia bilateral não tiveram resposta satisfatória (52,6% e 42,8% respectivamente. As síndromes vestibulares foram diagnosticadas através da anamnese e exame físico com testes clínicos específicos para avaliação da função vestibular. A identificação destas síndromes permitiu o tratamento adequado levando a uma boa evolução.The aims of this study were to identify the most common vestibular syndromes in a dizziness unit, and to observe their clinical aspects and response to treatment. Five hundred and fifteen patients were studied retrospectively in two institutions. Aspects of anamnesis, physical examination and the response to treatment were evaluated. The most frequent syndromes were: benign paroxysmal positioning vertigo (VPPB (28.5%, phobic postural vertigo (11.5%, central vertigo (10.1%, vestibular neuritis (9.7%, Menière disease (8.5%, and migraine (6.4%. A good response to treatment was observed in most patients with migraine (78.8%, VPPB (64%, vestibular neuritis (62%, Menière disease (54.5% and vestibular paroxismia (54.5%. On the other hand, patients with downbeat nystagmus and bilateral vestibulopathy had poor response (52.6% and 42.8%, respectively. The diagnosis of these most frequent vestibular syndromes were established through anamnesis and physical examination (with specific clinical tests for evaluation of the vestibular function. The correct diagnosis and adequate treatment are important since these syndromes may have a good prognosis.

  5. Achados vestibulares em pacientes portadores de fibromialgia / Vestibular findings in fibromyalgia patients

    Scientific Electronic Library Online (English)

    Bianca Simone, Zeigelboim; Denise Nunnes, Moreira.

    2011-09-01

    Full Text Available INTRODUÇÃO: A fibromialgia (FM) é uma síndrome musculoesquelética não inflamatória, de caráter crônico, de etiologia desconhecida, caracterizada por dor difusa, aumento da sensibilidade na palpação e por sintomas como fadiga, insônia, ansiedade, depressão, intolerância ao frio e queixas otológicas. [...] OBJETIVO: Avaliar o comportamento vestibular em pacientes portadores de fibromialgia. MÉTODO: Foi realizado um estudo retrospectivo de corte transversal. Avaliaram-se 25 pacientes na faixa etária entre 26 e 65 anos (média de idade - 52,2 anos e desvio padrão - 10,3 anos), submetidos aos seguintes procedimentos: anamnese, avaliação otorrinolaringológica e vestibular por meio da vectoeletronistagmografia. RESULTADOS: a) Os sintomas otoneurológicos mais evidenciados foram: dificuldade ou dor ao movimento do pescoço e dor irradiada para ombro ou braço (92,0%) em cada, tontura (84,0%) e cefaleia (76,0%). Os sintomas clínicos diversos mais relatados foram: depressão (80,0%), ansiedade (76,0%) e insônia (72,0%); b) O exame vestibular esteve alterado em 12 pacientes (48,0%) sendo localizado na prova calórica; c) Houve prevalência de alteração no sistema vestibular periférico e, d) Houve predomínio das disfunções vestibulares periféricas deficitárias. CONCLUSÃO: Este estudo permitiu verificar a importância do exame labiríntico o que ressalta que esse tipo de população deveria ser melhor estudada, uma vez que diversas doenças reumatológicas pelas suas manifestações e áreas de comprometimento podem gerar alterações vestibulares importantes. Abstract in english 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: Ev [...] aluate 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.

  6. Galvanic vestibular stimulation: a novel modulatory countermeasure for vestibular-associated movement disorders / Estimulação galvânica vestibular para corrigir transtornos neurológicos associados à disfunção vestibular

    Scientific Electronic Library Online (English)

    Carlos V., Rizzo-Sierra; Alexander, Gonzalez-Castaño; Fidias E., Leon-Sarmiento.

    2014-01-01

    Full Text Available A cinetose ou doença do movimento resulta de uma resposta neural anormal originada do desequilíbrio entre estímulos visuais, proprioceptivos e vestibulares, que melhora quando esse desequilíbrio é corrigido. A síndrome de adaptação espacial ou doença do espaço está relacionada à doença do movimento [...] e é desencadeada por mudanças bruscas de direção, inclinação e rotação da cabeça. Têm sido propostas várias medidas comportamentais e farmacológicas para controlar esses transtornos do movimento associados com o sistema vestibular, mas sem sucesso. A estimulação galvânica vestibular pode regular o desequilíbrio sensitivo-motor causado pela cinetose e pela doença do espaço modulando os canais iônicos GABA, relacionados à transmissão de impulsos nervosos no ouvido interno. Essa estimulação melhora a relação sinal-ruído dos impulsos proprioceptivos que acabam modulando a resposta motora, restabelecendo o equilíbrio e a marcha, recuperando a desorientação espacial causada pelos diversos gradientes de gravidade. Abstract in english Motion sickness or kinetosis is the result of the abnormal neural output originated by visual, proprioceptive and vestibular mismatch, which reverses once the dysfunctional sensory information becomes coherent. The space adaptation syndrome or space sickness relates to motion sickness; it is conside [...] red to be due to yaw, pith, and roll coordinates mismatch. Several behavioural and pharmacological measures have been proposed to control these vestibular-associated movement disorders with no success. Galvanic vestibular stimulation has the potential of up-regulating disturbed sensory-motor mismatch originated by kinetosis and space sickness by modulating the GABA-related ion channels neural transmission in the inner ear. It improves the signal-to-noise ratio of the afferent proprioceptive volleys, which would ultimately modulate the motor output restoring the disordered gait, balance and human locomotion due to kinetosis, as well as the spatial disorientation generated by gravity transition.

  7. Vestibular schwannoma: anatomical, medical and surgical perspective

    Directory of Open Access Journals (Sweden)

    Ashfaq Ul Hassan

    2013-06-01

    Full Text Available The term "acoustic" is a misnomer, as the tumor rarely arises from the acoustic (or cochlear division of the vestibulocochlear nerve. The correct medical term is vestibular schwannoma, because it involves the vestibular portion of the 8th cranial nerve. They are benign, rather rare tumors. They expand in size and grow larger; they can push against the brain. While the tumor does not actually invade the brain, the pressure of the tumor can displace brain tissue. [Int J Res Med Sci 2013; 1(3.000: 178-182

  8. Excitatory pathways from the vestibular nuclei to the NTS and the PBN and indirect vestibulo-cardiovascular pathway from the vestibular nuclei to the RVLM relayed by the NTS.

    Science.gov (United States)

    Cai, Yi-Ling; Ma, Wen-Ling; Wang, Jun-Qin; Li, Yi-Qian; Li, Min

    2008-11-13

    Previous studies have confirmed the existence of vestibulo-sympathetic pathways in the central nervous system. However, the exact pathways and neurotransmitters underlying this reflex are unclear. The present study was undertaken to investigate whether the vestibulo-cardiovascular responses are a result of activated glutamate receptors in the caudal vestibular nucleus. We also attempt to verify the indirect excitatory pathways from the vestibular nucleus (VN) to the rostral ventrolateral medulla (RVLM) using a tracing method combined with a vesicular glutamate transporter (VGluTs) immunofluorescence. In anesthetized rats, unilateral injection of l-glutamate (5 nmol) into the medial vestibular nucleus (MVe) and spinal vestibular nucleus (SpVe) slightly increased the mean arterial pressure (MVe: 93.29+/-11.58 to 96.30+/-11.66, SpVe: 91.72+/-15.20 to 95.48+/-17.16). Local pretreatment with the N-methyl-D-aspartate (NMDA)-receptor antagonist MK-801 (2 nmol) significantly attenuated the pressor effect of L-glutamate injected into the MVe compared to the contralateral self-control. After injection of biotinylated dextran amine (BDA) into the MVe and SpVe, and fluorogold (FG) into the RVLM, some BDA-labeled fibres and terminals in the nucleus of solitary tract (NTS) and the parabrachial nucleus (PBN) were immunoreactive for VGluT1 and VGluT2. Several BDA-labeled fibres were closely apposed to FG-labeled neurons in the NTS. These results suggested that activation of caudal vestibular nucleus neurons could induce pressor response and NMDA receptors might contribute to this response in the MVe. The glutamatergic VN-NTS and VN-PBN pathways might exist, and the projections from the VN to the RVLM relayed by the NTS comprise an indirect vestibulo-cardiovascular pathway in the brain stem. PMID:18809392

  9. Paciente com cefaleia e síndrome vestibular periférica: relato de caso Patient with headache and peripheral vestibular dysfunction: case report

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    Tatiane Maria Rossi

    2009-01-01

    Full Text Available TEMA: a Reabilitação Vestibular constitui-se numa opção de tratamento para pacientes portadores de síndrome vestibular periférica e cefaleia. PROCEDIMENTOS: o paciente, do sexo feminino com 26 anos de idade apresentava síndrome vestibular periférica acompanhada de crises de cefaleia. Foi realizada avaliação e terapia fonoaudiológica com exercícios de habituação vestibular além de fisioterapia e dieta recomendada pelo nutricionista. RESULTADOS: no período de 3 meses com reabilitação vestibular realizada semanalmente observou-se melhora no quadro vertiginoso e da cefaleia da paciente. CONCLUSÕES: evidenciou-se boa eficácia clínica para o tratamento desta paciente através da reabilitação vestibular com exercícios de habituação vestibular. Salienta-se a eficácia da reabilitação para a melhora na qualidade de vida da paciente e minimização das crises de cefaleia.BACKGROUND: vestibular rehabilitation is an option for treating peripheral vestibular syndrome and headache patients. PROCEDURES: the patient is a 29-year old woman and has Peripheral Vestibular Syndrome along with headache attacks. Evaluation and Phonoaudiological therapy with exercises of habituation tests with physical and nutritional therapy were carried out. RESULTS: in 3 month period with weekly vestibular rehabilitation therapy, we observed an improvement in the condition of the patient's vertigo and migraine. CONCLUSIONS: it was evident that the patient's treatment through the rehabilitation test with habituation test exercises had good efficiency. Please note the effectiveness of the rehabilitation for the improvement in the patient's life quality and minimization of headache attacks.

  10. Paciente com cefaleia e síndrome vestibular periférica: relato de caso / Patient with headache and peripheral vestibular dysfunction: case report

    Scientific Electronic Library Online (English)

    Tatiane Maria, Rossi; Naonne Santos Camargo, Luciano; Polliay Freire, Oricoli; Luciana Lozza de Moraes, Marchiori; Juliana Jandre, Melo.

    Full Text Available TEMA: a Reabilitação Vestibular constitui-se numa opção de tratamento para pacientes portadores de síndrome vestibular periférica e cefaleia. PROCEDIMENTOS: o paciente, do sexo feminino com 26 anos de idade apresentava síndrome vestibular periférica acompanhada de crises de cefaleia. Foi realizada a [...] valiação e terapia fonoaudiológica com exercícios de habituação vestibular além de fisioterapia e dieta recomendada pelo nutricionista. RESULTADOS: no período de 3 meses com reabilitação vestibular realizada semanalmente observou-se melhora no quadro vertiginoso e da cefaleia da paciente. CONCLUSÕES: evidenciou-se boa eficácia clínica para o tratamento desta paciente através da reabilitação vestibular com exercícios de habituação vestibular. Salienta-se a eficácia da reabilitação para a melhora na qualidade de vida da paciente e minimização das crises de cefaleia. Abstract in english BACKGROUND: vestibular rehabilitation is an option for treating peripheral vestibular syndrome and headache patients. PROCEDURES: the patient is a 29-year old woman and has Peripheral Vestibular Syndrome along with headache attacks. Evaluation and Phonoaudiological therapy with exercises of habituat [...] ion tests with physical and nutritional therapy were carried out. RESULTS: in 3 month period with weekly vestibular rehabilitation therapy, we observed an improvement in the condition of the patient's vertigo and migraine. CONCLUSIONS: it was evident that the patient's treatment through the rehabilitation test with habituation test exercises had good efficiency. Please note the effectiveness of the rehabilitation for the improvement in the patient's life quality and minimization of headache attacks.

  11. Degeneration of vestibular sensory cells caused by ablation of the vestibular aqueduct in the gerbil ear.

    Science.gov (United States)

    Kimura, R S; Trehey, J A; Hutta, J

    1995-02-01

    The vestibular aqueduct of the gerbil has a unique anatomic feature that makes it possible to selectively obliterate the endolymphatic sac with or without interfering with its venous drainage. In animals in which only the endolymphatic sac was ablated, endolymphatic hydrops was slight in the cochlea and was absent in the vestibular labyrinth. The cochlear and vestibular sensory cells were normal. In animals in which both the endolymphatic duct and the vein were obliterated, hydrops was slight, with the exception of a few cochleas that showed moderate hydrops. The sensory cells of the posterior canal cristae had degenerated in all specimens, while varied pathologic changes in cochlear and vestibular sensory cells were present in some specimens. These results suggest that hydrops is primarily due to blockage of the endolymphatic duct and sac and that degeneration of sensory cells occurs when blood flow in the vestibular aqueduct is impeded. Pathologic changes in the endolymphatic sac, including the vascular plexus at the endolymphatic sac, may play an important role in the production of endolymphatic hydrops and vestibular symptoms in Meniere's disease. PMID:7857019

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

    Scientific Electronic Library Online (English)

    Renato, Cal; Fayez, Bahmad Jr.

    2009-06-01

    Full Text Available 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 grava [...] dos 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. Abstract in english 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.

  13. Vestibular Dysfunctions in Cochlear Implant Patients; A Vestibular Evoked Myogenic Potential Study

    Directory of Open Access Journals (Sweden)

    Masoud Motasaddi Zarandy

    2011-12-01

    Full Text Available Background and Aim: Vestibular evoked myogenic potential in response to click or short tone burst stimuli have been used as a clinical test for distinguish saccule and inferior vestibular nerve diseases. Different studies show that cochlear implant could have inverse effects on vestibular structures. We aimed to investigate vestibular evoked myogenic potential in unilateral cochlear implanted individuals in compare to normal individuals.Methods: Thirty-three unilateral cochlear implanted patients (mean age 19.96 years and 30 normal hearing individuals (mean age 24-27 years as control group were enrolled in this cross- sectional study. Absolute latencies and amplitudes of myogenic potential responses were measured and compared in both groups.Results: Myogenic potential recorded in both ears of all controls were normal. No response could be recorded in 16 patients (48.48% from both ears. In three patients, responses were recorded in both ears though the amplitude of waves was reduced in implanted ear. Unilateral response could be recorded in 14 patients only in their non-implanted ear.Conclusion: Vestibular evoked myogenic potential test is a useful tool for assessing saccular function in cochlear implant patients. Damages of osseous spiral lamina and basilar membrane after cochlear implantation could result in dysfunctions of vestibular organs specially saccule. It seems that saccule could be easily damaged after cochlear implantation. This would cause absence or reduced amplitudes in myogenic potential.

  14. Descripción, interpretación, análisis e importancia del nistagmus inducido por la hiperventilación en el estudio de patologías vestibulares periféricas y centrales / Description, interpretation, analysis and importance of hyperventilation -induced nystagmus in the study of the peripheral and central vestibular disorders

    Scientific Electronic Library Online (English)

    Alejandro, Peña M.

    2012-04-01

    Full Text Available Recientes estudios clínicos han revelado la utilidad del test del nistagmus inducido por la hiperventilación aguda, en la investigación de patologías vestibulares retrolaberínticas, neurales y de origen central, con la aparición de nistagmus paréticos o bien excitatorios. El propósito de este estudi [...] o ha sido: primero, conocer la sensibilidad de este examen según el análisis de los estudios de diferentes autores; segundo, entender la fisiopatología de este nistagmus inducido por la hiperventilación y tercero, efectuar una interpretación y análisis de este examen que permita obtener conclusiones sólidas del mejor nivel de medicina basada en evidencias. Para efectuar este estudio y análisis se procedió a una investigación exhaustiva de las publicaciones sobre el tema en los últimos 25 años, recurriendo para ello como fuentes de información a las principales bases de datos biomédicos y a la revisión en texto completo de estas publicaciones. Llamó la atención la escasez de trabajos clínicos publicados sobre el tema que no superan los 40, y también la escasez de trabajos sobre la fisiopatología del nistagmus inducido por la hiperventilación aguda. La metódica del test es muy simple por lo que su utilización resulta muy atractiva, con un escaso número de falsos positivos. La mayor parte de los estudios publicados, se focaliza en su utilización en el schwanoma vestibularyen la neuronitis vestibular. Respecto al schwanoma vestibular de un total de 107 pacientes estudiados el test fue positivo en el 80% de los casos, con aparición de nistagmus ipsilesional o contralesional. En la neuronitis vestibular la positividad del test alcanzó a 60°% de un total de 272 pacientes estudiados y que estaba en relación directa con el tiempo de evolución de la enfermedad. En la esclerosis múltiple, en pacientes con síntomas vestibulares, la positividad del test fue de 75°%, en cambio en aquellos pacientes sin síntomas vestibulares la positividad fue de sólo 7°%. En las enfermedades cerebelosas, particularmente las degenerativas, la positividad de este test fue de 78°%. La pesquisa del nistagmus inducido por la hiperventilación, fue una prueba poco significativa estadísticamente, en otras patologías vestibulares períféricas tales como la enfermedad de Ménière o el VPPB, así como en otras enfermedades vestibulares centrales, salvo las de origen vascular por insuficiencia del sistema vértebro-basilar. El estudio y análisis de las publicaciones sobre el nistagmus inducido por la hiperventilación aguda, permite concluir que es un test de fácil realización; que ante la sospecha de un schwanoma vestibular, orienta en el estudio de aquellos pacientes que requieran un estudio de R.M. Que ayuda en el diagnóstico diferencial de una neuronitisvestibular y finalmente que permite en lesiones vestibulares centrales particularmente degenerativas y vasculares un estudio más profundo y adecuado de estos pacientes. Abstract in english Recent clinical studies have revealed the usefulness of the hyperventilation-induced nystagmus in retrolabyrinthine and central vestibular diseases with the appearance either excitatory (ipsilateral) or paretic (contralateral) nystagmus. The objectives of this study have been: 1) to get to know the [...] sensitivity of the exam, according to the best literature available; 2) to get to know the physiopathology of this hyperventilation-induced nystagmus, and 3) to carry out an analysis and interpretation of this exam in order to reach solid conclusions of the highest level in evidence based medicine. An exhaustive research of literature published on this topic in the last 25 years was carried out. The main source of information being the most important medical data-based publications and also a thorough revision of these texts. The scarce number of publications on this topic (not more than 40) is what strikes the attention most, as well as the very few studies of the physiopathology of the hyperventilation-induced nystagmus. The method of the test is a

  15. Descripción, interpretación, análisis e importancia del nistagmus inducido por la hiperventilación en el estudio de patologías vestibulares periféricas y centrales Description, interpretation, analysis and importance of hyperventilation -induced nystagmus in the study of the peripheral and central vestibular disorders

    Directory of Open Access Journals (Sweden)

    Alejandro Peña M

    2012-04-01

    Full Text Available Recientes estudios clínicos han revelado la utilidad del test del nistagmus inducido por la hiperventilación aguda, en la investigación de patologías vestibulares retrolaberínticas, neurales y de origen central, con la aparición de nistagmus paréticos o bien excitatorios. El propósito de este estudio ha sido: primero, conocer la sensibilidad de este examen según el análisis de los estudios de diferentes autores; segundo, entender la fisiopatología de este nistagmus inducido por la hiperventilación y tercero, efectuar una interpretación y análisis de este examen que permita obtener conclusiones sólidas del mejor nivel de medicina basada en evidencias. Para efectuar este estudio y análisis se procedió a una investigación exhaustiva de las publicaciones sobre el tema en los últimos 25 años, recurriendo para ello como fuentes de información a las principales bases de datos biomédicos y a la revisión en texto completo de estas publicaciones. Llamó la atención la escasez de trabajos clínicos publicados sobre el tema que no superan los 40, y también la escasez de trabajos sobre la fisiopatología del nistagmus inducido por la hiperventilación aguda. La metódica del test es muy simple por lo que su utilización resulta muy atractiva, con un escaso número de falsos positivos. La mayor parte de los estudios publicados, se focaliza en su utilización en el schwanoma vestibularyen la neuronitis vestibular. Respecto al schwanoma vestibular de un total de 107 pacientes estudiados el test fue positivo en el 80% de los casos, con aparición de nistagmus ipsilesional o contralesional. En la neuronitis vestibular la positividad del test alcanzó a 60°% de un total de 272 pacientes estudiados y que estaba en relación directa con el tiempo de evolución de la enfermedad. En la esclerosis múltiple, en pacientes con síntomas vestibulares, la positividad del test fue de 75°%, en cambio en aquellos pacientes sin síntomas vestibulares la positividad fue de sólo 7°%. En las enfermedades cerebelosas, particularmente las degenerativas, la positividad de este test fue de 78°%. La pesquisa del nistagmus inducido por la hiperventilación, fue una prueba poco significativa estadísticamente, en otras patologías vestibulares períféricas tales como la enfermedad de Ménière o el VPPB, así como en otras enfermedades vestibulares centrales, salvo las de origen vascular por insuficiencia del sistema vértebro-basilar. El estudio y análisis de las publicaciones sobre el nistagmus inducido por la hiperventilación aguda, permite concluir que es un test de fácil realización; que ante la sospecha de un schwanoma vestibular, orienta en el estudio de aquellos pacientes que requieran un estudio de R.M. Que ayuda en el diagnóstico diferencial de una neuronitisvestibular y finalmente que permite en lesiones vestibulares centrales particularmente degenerativas y vasculares un estudio más profundo y adecuado de estos pacientes.Recent clinical studies have revealed the usefulness of the hyperventilation-induced nystagmus in retrolabyrinthine and central vestibular diseases with the appearance either excitatory (ipsilateral or paretic (contralateral nystagmus. The objectives of this study have been: 1 to get to know the sensitivity of the exam, according to the best literature available; 2 to get to know the physiopathology of this hyperventilation-induced nystagmus, and 3 to carry out an analysis and interpretation of this exam in order to reach solid conclusions of the highest level in evidence based medicine. An exhaustive research of literature published on this topic in the last 25 years was carried out. The main source of information being the most important medical data-based publications and also a thorough revision of these texts. The scarce number of publications on this topic (not more than 40 is what strikes the attention most, as well as the very few studies of the physiopathology of the hyperventilation-induced nystagmus. The method of the test is a simple one; this fact makes its applica

  16. Perspectives in vestibular diagnostics and therapy [

    Directory of Open Access Journals (Sweden)

    Ernst, Arneborg

    2012-04-01

    Full Text Available [english] Vestibular diagnostics and therapy ist the mirror of technological, scientific and socio-economics trends as are other fields of clinical medicine. These trends have led to a substantial diversification of the field of neurotology.The improvements in diagnostics have been characterized by the introduction of new receptor testing tools (e.g., VEMPs, progress in imaging (e.g., the endolymphatic hydrops and in the description of central-vestibular neuroplasticity. The etiopathology of vestibular disorders has been updated by geneticists (e.g., the description of the COCH gene mutations, the detection of structural abnormalities (e.g., dehiscence syndromes and related disorders (e.g. migraine-associated vertigo. The therapeutic options were extended by re-evaluation of techniques known a long time ago (e.g., saccus exposure, the development of new approaches (e.g., dehiscence repair and the introduction of new drug therapy concepts (e.g., local drug delivery. Implantable, neuroprosthetic solutions have not yet reached experimental safety and validity and are still far away. However, externally worn neuroprosthetic solution were introduced in the rehab of vestibular disorders (e.g., VertiGuard system.These and related trends point into a medical future which is characterized by presbyvertigo as classical sign of the demographic changes ahead, by shortage of financial resources and a medico-legally over-regulated, even hostile environment for physicians in clinical medicine.

  17. Vesibulotoxicity and Management of Vestibular Disorders

    Science.gov (United States)

    Carey, John P.

    2005-01-01

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

  18. Vestibular effects on cerebral blood flow

    Science.gov (United States)

    Serrador, Jorge M; Schlegel, Todd T; Black, F Owen; Wood, Scott J

    2009-01-01

    Background Humans demonstrate a number of unique adaptations that allow for the maintenance of blood pressure and brain blood flow when upright. While several physiological systems, including cerebral autoregulation, are involved in this adaptation the unique role the vestibular system plays in helping to maintain brain blood flow is just beginning to be elucidated. In this study, we tested the hypothesis that stimulation of the vestibular system, specifically the otoliths organs, would result in changes in cerebral blood flow. Results To test our hypothesis, we stimulated the vestibular organs of 25 healthy subjects by pitch tilt (stimulates both canals and otoliths) and by translation on a centrifuge (stimulates otoliths and not the canals) at five frequencies: 0.5, 0.25, 0.125 and 0.0625 Hz for 80 sec and 0.03125 Hz for 160 sec. Changes in cerebral flow velocity (by transcranial Doppler) and blood pressure (by Finapres) were similar during both stimuli and dependent on frequency of stimulation (P < 0.01). However, changes in cerebral blood flow were in opposition to changes in blood pressure and not fully dependent on changes in end tidal CO2. Conclusion The experimental results support our hypothesis and provide evidence that activation of the vestibular apparatus, specifically the otolith organs, directly affects cerebral blood flow regulation, independent of blood pressure and end tidal CO2 changes. PMID:19775430

  19. [The interaction of vestibular inputs with differing orientations of the otoliths in a gravitational field].

    Science.gov (United States)

    Stolbkov, Iu K; Orlov, I V; Sabanov, V S

    1994-08-01

    In alert pigeons Columba livia effects of static tilts about fore-aft and binaural axes (angles of tilts: 30-40 deg) on neck and ocular nystagmus elicited by monaural galvanic stimulation of the lateral semicircular canals with sinusoidal currents (peak amplitudes: 20-100 microA; period: 35 sec) were investigated. It was shown that the same angles of the tilts elicited different changes of horizontal nystagmus parameters in different animals. In some of them changes of quantitative characteristics of opposite-directed nystagmus differed with signs. Data support the correctness of recently (Stolbkov, 1989) proposed scheme of forming vestibulomotor reactions, according to which signals from heterolateral vestibular nuclei, during nystagmus, which are integrated, contain both canal and otolith components independent of stimulus mode addressed to canals or otoliths (separately or jointly). Results suggest also that caloric test may be a source of incorrect conclusions concerning state of vestibular system during static tilts the responses of functionally asymmetric semicircular canals may be symmetric ones. Moreover data suggest that sensitivity of convergent vestibular neurons to the canal signals is different depending on separated or combined canal and otolith stimulations. PMID:7534567

  20. Purkinje cell responses during visually and vestibularly driven smooth eye movements in mice

    Science.gov (United States)

    Katoh, Akira; Shin, Soon-Lim; Kimpo, Rhea R; Rinaldi, Jacob M; Raymond, Jennifer L

    2015-01-01

    Introduction An essential complement to molecular-genetic approaches for analyzing the function of the oculomotor circuitry in mice is an understanding of sensory and motor signal processing in the circuit. Although there has been extensive analysis of the signals carried by neurons in the oculomotor circuits of species, such as monkeys, rabbits and goldfish, relatively little in vivo physiology has been done in the oculomotor circuitry of mice. We analyzed the contribution of vestibular and nonvestibular signals to the responses of individual Purkinje cells in the cerebellar flocculus of mice. Methods We recorded Purkinje cells in the cerebellar flocculus of C57BL/6 mice during eye movement responses to vestibular and visual stimulation. Results As in other species, most individual Purkinje cells in mice carried both vestibular and nonvestibular signals, and the most common response across cells was an increase in firing in response to ipsiversive eye movement or ipsiversive head movement. When both the head and eyes were moving, the Purkinje cell responses were approximated as a linear summation of head and eye velocity inputs. Unlike other species, floccular Purkinje cells in mice were considerably more sensitive to eye velocity than head velocity. Conclusions The signal content of Purkinje cells in the cerebellar flocculus of mice was qualitatively similar to that in other species. However, the eye velocity sensitivity was higher than in other species, which may reflect a tuning to the smaller range of eye velocities in mice. PMID:25642393

  1. Vestibular Loss and Balance Training Cause Similar Changes in Human Cerebral White Matter Fractional Anisotropy

    Science.gov (United States)

    Hummel, Nadine; Hüfner, Katharina; Stephan, Thomas; Linn, Jennifer; Kremmyda, Olympia; Brandt, Thomas; Flanagin, Virginia L.

    2014-01-01

    Patients with bilateral vestibular loss suffer from severe balance deficits during normal everyday movements. Ballet dancers, figure skaters, or slackliners, in contrast, are extraordinarily well trained in maintaining balance for the extreme balance situations that they are exposed to. Both training and disease can lead to changes in the diffusion properties of white matter that are related to skill level or disease progression respectively. In this study, we used diffusion tensor imaging (DTI) to compare white matter diffusivity between these two study groups and their age- and sex-matched controls. We found that vestibular patients and balance-trained subjects show a reduction of fractional anisotropy in similar white matter tracts, due to a relative increase in radial diffusivity (perpendicular to the main diffusion direction). Reduced fractional anisotropy was not only found in sensory and motor areas, but in a widespread network including long-range connections, limbic and association pathways. The reduced fractional anisotropy did not correlate with any cognitive, disease-related or skill-related factors. The similarity in FA between the two study groups, together with the absence of a relationship between skill or disease factors and white matter changes, suggests a common mechanism for these white matter differences. We propose that both study groups must exert increased effort to meet their respective usual balance requirements. Since balance training has been shown to effectively reduce the symptoms of vestibular failure, the changes in white matter shown here may represent a neuronal mechanism for rehabilitation. PMID:24776524

  2. Calyx and dimorphic neurons of mouse Scarpa's ganglion express histamine H3 receptors

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    Zucca Gianpiero

    2009-06-01

    Full Text Available Abstract Background Histamine-related drugs are commonly used in the treatment of vertigo and related vestibular disorders. The site of action of these drugs however has not been elucidated yet. Recent works on amphibians showed that histamine H3 receptor antagonists, e.g. betahistine, inhibit the afferent discharge recorded from the vestibular nerve. To assess the expression of H3 histamine receptors in vestibular neurons, we performed mRNA RT-PCR and immunofluorescence experiments in mouse Scarpa's ganglia. Results RT-PCR analysis showed the presence of H3 receptor mRNA in mouse ganglia tissue. H3 protein expression was found in vestibular neurons characterized by large and roundish soma, which labeled for calretinin and calbindin. Conclusion The present results are consistent with calyx and dimorphic, but not bouton, afferent vestibular neurons expressing H3 receptors. This study provides a molecular substrate for the effects of histamine-related antivertigo drugs acting on (or binding to H3 receptors, and suggest a potential target for the treatment of vestibular disorders of peripheral origin.

  3. Vestibular characterization in the menstrual cycle / Caracterização vestibular no ciclo menstrual

    Scientific Electronic Library Online (English)

    Cintia, Ishii; Lucia Kazuko, Nishino; Carlos Alberto Herrerias de, Campos.

    2009-06-01

    Full Text Available 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-menstrua [...] l. 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 a presença de diferença estatisticamente significante no ciclo ovariano somente para as provas do exame vestibular de calibração, movimentos sacádicos, prova rotatória pendular decrescente e prova calórica. As variáveis: idade, ciclo menstrual regulado, casos de surdez ou tontura na família, doenças anteriores, e sintomas do período pré-menstrual como zumbido, cefaleia, distúrbio do sono, ansiedade, náusea e hiperacusia também podem interferir no exame otoneurológico. CONCLUSÃO: Há diferenças nos resultados do exame vestibular em mulheres sadias entre os períodos pré e pós menstrual. Abstract in english 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: twen [...] ty 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.

  4. 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 a presença de diferença estatisticamente significante no ciclo ovariano somente para as provas do exame vestibular de calibração, movimentos sacádicos, prova rotatória pendular decrescente e prova calórica. As variáveis: idade, ciclo menstrual regulado, casos de surdez ou tontura na família, doenças anteriores, e sintomas do período pré-menstrual como zumbido, cefaleia, distúrbio do sono, ansiedade, náusea e hiperacusia também podem interferir no exame otoneurológico. CONCLUSÃO: Há diferenças nos resultados do exame vestibular em mulheres sadias entre os períodos pré e pós menstrual.

  5. Evaluation of postural control in unilateral vestibular hypofunction / Avaliação do controle postural na hipofunção vestibular unilateral

    Scientific Electronic Library Online (English)

    Rafaela Maia, Quitschal; Jackeline Yumi, Fukunaga; Maurício Malavasi, Ganança; Heloísa Helena, Caovilla.

    2014-07-01

    Full Text Available INTRODUÇÃO: Pacientes com hipofunção vestibular, achado típico em vestibulopatias periféricas, apresentam alterações de equilíbrio corporal. OBJETIVO: Avaliar o controle postural de pacientes vertiginosos com hipofunção vestibular unilateral. MÉTODO: Trata-se de um estudo clínico transvers [...] al. No total, 25 pacientes vertiginosos com hipofunção vestibular unilateral e um grupo controle homogêneo de 32 indivíduos hígidos foram submetidos à avaliação otoneurológica, incluindo a posturografia do Tetrax Interactive Balance System em oito diferentes condições sensoriais. RESULTADOS: O grupo experimental apresentou valores significantemente maiores do que o grupo controle quanto ao índice de estabilidade geral, índice de distribuição de peso, índice de sincronização da oscilação postural direita/esquerda e dedos/calcanhar, faixas de frequência de oscilação postural (F1, F2-F4, F5-F6, F7-F8) e índice de risco de queda, em diferentes condições sensoriais. CONCLUSÃO: Alterações de distribuição de peso, sincronização da oscilação postural direita/esquerda e dedos/calcanhares, faixas de frequência de oscilação postural e do índice de risco de queda caracterizam o comprometimento do controle postural em pacientes vertiginosos com hipofunção vestibular unilateral. Abstract in english 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.

  6. Virtual Neuron

    Science.gov (United States)

    2009-04-14

    Neurons are able to communicate with each other using biochemicals called neurotransmitters. Use Virtual Neuron to explore neurotransmitter properties, make neurons fire, and manipulate neural circuits.

  7. Rizatriptan reduces vestibular-induced motion sickness in migraineurs.

    Science.gov (United States)

    Furman, Joseph M; Marcus, Dawn A; Balaban, Carey D

    2011-02-01

    A previous pilot study suggested that rizatriptan reduces motion sickness induced by complex vestibular stimulation. In this double-blind, randomized, placebo-controlled study we measured motion sickness in response to a complex vestibular stimulus following pretreatment with either rizatriptan or a placebo. Subjects included 25 migraineurs with or without migraine-related dizziness (23 females) aged 21-45 years (31.0 ± 7.8 years). Motion sickness was induced by off-vertical axis rotation in darkness, which stimulates both the semicircular canals and otolith organs of the vestibular apparatus. Results indicated that of the 15 subjects who experienced vestibular-induced motion sickness when pretreated with placebo, 13 showed a decrease in motion sickness following pretreatment with rizatriptan as compared to pretreatment with placebo (P rizatriptan, reduces vestibular-induced motion sickness by influencing serotonergic vestibular-autonomic projections. PMID:20862509

  8. El examen vestibular abreviado, descripción, interpretación y análisis / The abbreviated vestibular exam, description, interpretation and analysis

    Scientific Electronic Library Online (English)

    Alejandro, Peña M.

    2011-08-01

    Full Text Available Introducción: En el examen vestibular de un paciente vertiginoso juegan un rol muy importante las pruebas calóricas, pero la realización de éstas, unida a las nuevas pruebas que ha traído el avance tecnológico y computacional de la medicina, ha significado que el examen vestibular se ha convertido e [...] n la práctica diaria en un estudio muy largo y oneroso, por tal motivo parece útil la realización de un examen vestibular abreviado preliminar hecho en la misma consulta del médico que permita dar una orientación diagnóstica de bases sólidas. Objetivos: El propósito de este estudio es la descripción, interpretación y análisis crítico del llamado "examen vestibular de 10 minutos del paciente mareado"y que permita llegar a conclusiones sobre la sensibilidad y especificidad de este examen abreviado. Material y método: En este estudio, se describen, interpretan y analizan, según la información bibliográfica disponible, particularmente aquellos estudios de la medicina basada en evidencias las siguientes pruebas propuestas en el examen vestibular abreviado: Búsqueda del nistagmus espontáneo, búsqueda del nistagmus de mirada excéntrica, estudio de los movimientos oculares lentos o de rastreo ocular, estudio de los movimientos oculares rápidos o sacadas, test de Halmagyi, test de agitación cefálica, test de agudeza visual dinámica, test de inhibición de la fijación del nistagmus, maniobra de Dix y Hallpike, test de otoscopía neumática, estudio cerebeloso, estudio de la sensibilidad profunda, prueba de Romberg y estudio de la marcha. Debido a que varias de estas pruebas se efectúan en la prueba vestibular clásica sólo se analizan y discuten aquellas que no se efectúan de rutina en este examen. Resultados: Las pruebas analizadas del examen vestibular abreviado revelan en su gran mayoría baja sensibilidad, menor de 50%, pero una buena especificidad. Con algún entrenamiento básico son fáciles de realizar y requieren poco tiempo para su ejecución pero sí, mucho más que 10 minutos. Discusión: Considerando el largo tiempo que requiere el especialista para efectuar un examen vestibular completo, un estudio básico resulta necesario para orientar la investigación clínica de un paciente vertiginoso. Las pruebas propuestas en este examen, tienen baja sensibilidad consideradas individualmente, pero la realización de todas ellas en su conjunto, le confiere al estudio una gran fortaleza y credibilidad, esto necesariamente unido a una muy buena anamnesis con cuestionario estructurado preestablecido. Conclusiones: El examen vestibular abreviado es un buen estudio, en que si bien las diferentes pruebas tienen baja sensibilidad, el resultado de la suma de todas ellas le confiere al examen una buena confiabilidad. Para su realización es indispensable un buen manejo de las pruebas y un buen conocimiento de la otoneurología por parte del examinador para su correcta interpretación. No existen estudios de medicina basada en evidencias de nivel 1 ó 2 que le otorguen alta credibilidad a estas pruebas. Este examen no debe reemplazar al examen vestibular clásico o formal, incluyendo las pruebas calóricas bi-termales, sino que deben ser consideradas como un estudio básico que permite orientar al especialista para tomar decisiones apropiadas diagnósticas y terapéuticas. Abstract in english Introduction: Caloric tests play a very important role in a patient's vestibular exam. But these exams, along with the new test brought about by both technology and computing in Medicine, have turned these examinations into very long and expensive procedures. Taking all this into account, it seems s [...] uitable the realization of a preliminary vestibular exam performed in the doctor's consultation office. This will allow a diagnostic guideline with solid foundations. Aim: To describe, interpret, and carry out a critical analysis of the so called "10 minute vestibular examination of the dizzy patient" in order to get to some conclusions about sensitivity and specificity of this short exam. Mat

  9. Internal models and neural computation in the vestibular system

    OpenAIRE

    Green, Andrea M.; Angelaki, Dora E.

    2010-01-01

    The vestibular system is vital for motor control and spatial self-motion perception. Afferents from the otolith organs and the semicircular canals converge with optokinetic, somatosensory and motor-related signals in the vestibular nuclei, which are reciprocally interconnected with the vestibulocerebellar cortex and deep cerebellar nuclei. Here, we review the properties of the many cell types in the vestibular nuclei, as well as some fundamental computations implemented within this brainstem?...

  10. A vestibular sensation: probabilistic approaches to spatial perception

    OpenAIRE

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

    2009-01-01

    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 differ...

  11. Vestibular involvement in adults with HIV/AIDS

    OpenAIRE

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

    2014-01-01

    OBJECTIVE : 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,s...

  12. Menière's disease : pathogenesis of vestibular dysfunction and new diagnostic tests

    OpenAIRE

    Kingma, Charlotte Mariane

    2011-01-01

    Menière’s disease (MD) is characterised by three symptoms: fluctuating hearing loss, episodic vertigo, and tinnitus. Although vertigo is the most severe complaint in MD, it has not been studied widely. The focus of this research was on the function of the vestibular system as an explanation for vertigo in MD. An animal model was used to investigate the function of the vestibular system. The creation of an acute endolymphatic hydrops in the vestibular system did not cause the symptoms o...

  13. Retrosigmoid approach for vestibular neurectomy in Meniere's disease

    OpenAIRE

    Ducati, Alessandro; Benech, Franco; Albera, Roberto; Fontanella, Marco Maria

    2005-01-01

    BACKGROUND: Vestibular nerve section is considered to be the most effective surgical procedure to control intractable symptoms secondary to Meniere's disease (MD). This study was developed to analyze the adequacy of retrosigmoid vestibular neurectomy in terms of vertigo control, hearing preservation and clinical complications of this procedure. METHODS: A retrospective review was carried out on 14 patients affected by definite unilateral MD who underwent vestibular neurectomy via the retrosig...

  14. Microsurgical Posterior Fossa Vestibular Neurectomy: An Evolution in Technique

    OpenAIRE

    Silverstein, Herbert; Norrell, Horace; Wanamaker, Hayes; Flanzer, John

    1991-01-01

    Between 1925 and 1945, Walter Dandy and Kenneth McKenzie performed more than 700 posterior fossa eighth nerve sections and vestibular neurectomies, treating the intractable vertigo accompanying Meniere's disease. During the past 10 years, using microsurgical techniques and reaching the posterior fossa through the temporal bone, vestibular neurectomy has enjoyed a resurgence of popularity. When hearing is to be preserved, vestibular neurectomy is the surgical treatment of choice, if the patien...

  15. Effects of betahistine on the spatiotemporal response properties of vestibulospinal neurons to labyrinthine volleys.

    Science.gov (United States)

    Barresi, Massimo; Bruschini, Luca; Li Volsi, Guido; Manzoni, Diego

    2005-05-16

    Betahistine, a drug used in the treatment of vestibular disorders, speeds-up the recovery from hemilabyrinthectomy in experimental animals, likely through the activation of histamine receptors. In order to better understand the mechanism of action of this drug we investigated, in adult, urethane anesthetized rats, whether betahistine modifies the spatial (directional) and temporal response properties of vestibular nuclear neurons to the labyrinthine input, as well as the convergence of different labyrinthine signals on single units. Extracellular single-unit activity was recorded from the caudal, spinal-projecting region of the vestibular nuclei during tilt of the animal, before and after i.p. injection of betahistine. The two orthogonal directions of maximal and minimal response to tilt, as well as the corresponding gains were determined for each neuron. Betahistine reduced the maximal response gain of units showing larger basal values of this parameter and increased it in neurons with smaller basal values, while the minimal response gain was on the average raised. These changes led to a significant decrease in the spatial specificity of the neurons, suggesting that betahistine affects the process of spatiotemporal convergence on vestibular units, likely through a rearrangement of the various inputs. This could be related to the effect of the drug on vestibular compensation. PMID:15878499

  16. Task, muscle and frequency dependent vestibular control of posture.

    Science.gov (United States)

    Forbes, Patrick A; Siegmund, Gunter P; Schouten, Alfred C; Blouin, Jean-Sébastien

    2014-01-01

    The vestibular system is crucial for postural control; however there are considerable differences in the task dependence and frequency response of vestibular reflexes in appendicular and axial muscles. For example, vestibular reflexes are only evoked in appendicular muscles when vestibular information is relevant to postural control, while in neck muscles they are maintained regardless of the requirement to maintain head on trunk balance. Recent investigations have also shown that the bandwidth of vestibular input on neck muscles is much broader than appendicular muscles (up to a factor of 3). This result challenges the notion that vestibular reflexes only contribute to postural control across the behavioral and physiological frequency range of the vestibular organ (i.e., 0-20 Hz). In this review, we explore and integrate these task-, muscle- and frequency-related differences in the vestibular system's contribution to posture, and propose that the human nervous system has adapted vestibular signals to match the mechanical properties of the system that each group of muscles controls. PMID:25620919

  17. Status of vestibular function after prolonged bedrest

    Science.gov (United States)

    Burgeat, M.; Toupet, M.; Loth, D.; Ingster, I.; Guell, A.; Coll, J.

    6 young, healthy, male volunteers were submitted to one week of head down (-4°) bedrest. This position simulates the cerebral hemodynamic conditions in weightlessness. Measurements of vestibular equilibrium and of oculomotor system function were made before and after the prolonged bedrest. Analysis of the results indicates that vestibular responses, as measured by the maximal speed of the slow phase of the provoked nystagmus (caloric and sinusoidal rotatory stimulations), are decreased after prolonged bedrest. This statistically significant diminution requires confirmation with a greater number of cases. The reflex conflicting or interacting with the cervico-ocular and optokinetic reflexes on the one hand and the foveal vision on the other, is one of several possible explanations for the observed changes.

  18. Vestibular Schwannoma Atypically Invading Temporal Bone

    Science.gov (United States)

    Park, Soo Jeong; Yang, Na-Rae

    2015-01-01

    Vestibular schwannoma (VS) usually present the widening of internal auditory canal (IAC), and these bony changes are typically limited to IAC, not extend to temporal bone. Temporal bone invasion by VS is extremely rare. We report 51-year-old man who revealed temporal bone destruction beyond IAC by unilateral VS. The bony destruction extended anteriorly to the carotid canal and inferiorly to the jugular foramen. On histopathologic examination, the tumor showed typical benign schwannoma and did not show any unusual vascularity or malignant feature. Facial nerve was severely compressed and distorted by tumor, which unevenly eroded temporal bone in surgical field. Vestibular schwannoma with atypical invasion of temporal bone can be successfully treated with combined translabyrinthine and lateral suboccipiral approach without facial nerve dysfunction. Early detection and careful dissection of facial nerve with intraoperative monitoring should be considered during operation due to severe adhesion and distortion of facial nerve by tumor and eroded temporal bone. PMID:25932298

  19. Growth dynamics of the vestibular schwannoma

    OpenAIRE

    Varughese, Jobin K.

    2012-01-01

    Introduction: Studies concerning vestibular schwannoma (VS) are inconsistent in reporting of tumor size and growth. This means that results found in one paper using one set of definitions cannot be compared directly with results found in another paper with another set of definitions. It is a challenge to make clinical decisions from studies with such disparate definitions, as it is difficult to know how reliable the individual findings are. This thesis thus aimed to empirically...

  20. Complications of microsurgery of vestibular schwannoma.

    Czech Academy of Sciences Publication Activity Database

    Betka, J.; Zv??ina, E.; Balogová, Zuzana; Profant, Oliver; Sk?ivan, J.; Kraus, J.; Lisý, J.; Syka, Josef; Chovanec, M.

    2014-01-01

    Ro?. 2014, May 28 (2014), s. 315952. ISSN 2314-6133 R&D Projects: GA MZd NT12459 Grant ostatní: 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

  1. Can Electrical Vestibular Noise Be Used for the Treatment of Brain Diseases?

    Science.gov (United States)

    Yamamoto, Yoshiharu; Soma, Rika; Struzik, Zbigniew R.; Kwak, Shin

    2005-11-01

    The therapy currently available for the treatment of degenerative neurological diseases is far from satisfactory, and a novel therapeutic strategy, especially for pharmacologically unresponsive patients, would be welcomed. The vestibular nerves are known to influence neuronal circuits in the medullary cardiovascular areas and, through the cerebellar vermis, the basal ganglia and the limbic system. By means of noisy galvanic vestibular stimulation (GVS), it may now be possible to ameliorate blunted responsiveness of degenerated neuronal circuits in the brains of multiple system atrophy (MSA) and/or Parkinson's disease (PD) patients, through a mechanism known as stochastic resonance. We evaluate the effect of 24-hour noisy GVS on long-term heart rate dynamics in seven MSA patients, and on daytime locomotor activity dynamics in twelve patients with either PD or levodopa unresponsive parkinsonism. Short-range heart rate variability and long-range anti-correlation of trunk activity are significantly increased by the noisy GVS compared with sham stimulation, suggestive of improved autonomic and motor responsiveness. The noisy GVS is effective in boosting the neuro-degenerative brains of MSA and/or PD patients, including those unresponsive to standard levodopa therapy.

  2. MRI in a quiescent vestibular schwannoma

    International Nuclear Information System (INIS)

    Vestibular schwannomas are benign neoplasms that take origin from Schwann cells, the majority arise from the vestibular branch of VIII cranial nerve. Unilateral sensorineural hearing loss is the most common symptom referred by patients who suffer this disease. With the advent and increasing use of MRI the diagnosis of this intra labyrinthine tumor has become more frequent. Paramagnetic contrast gadolinium has precise indication in the study protocol of this pathology. The high sensitivity of this method allows an early diagnosis. In patients with low auditory loss an excision of intra labyrinthine small tumors can offer a better therapeutic chance. We report a case of a 25 years old woman with progressive hearing loss. MRI with gadolinium enhancement demonstrated an intra vestibular schwannoma. In a follow-up control after 5 years MRI revealed no significant changes in tumor size or signal intensity. 3-D volumetric reconstruction offered complimentary information about this 'quiescent' schwannoma. Considering the tumoral behavior (without growth within five years) and the degree of hearing loss no invasive therapy was performed. (author)

  3. Electrical vestibular stimulation and space motion sickness

    Science.gov (United States)

    Severac, Alexandra

    Electrical vestibular stimulation (EVS) in dynamic balance condition was studied in order to search for a new provocative test of space motion sickness (SMS). SMS is usually attributed to a sensory conflict caused by exposure to microgravity. Vestibular information is conflicting but also unusual and insignificant. EVS is in accordance with this feature because it is not the adequate stimulus of the vestibular receptors. EVS was achieved by means of binaural electrical stimulation. Effects of EVS were potentiated by compelling the subject to maintain dynamic balance on a seesaw. The quantification of this function was performed before, during and after EVS in order to investigate a possible relationship between objective consequences of EVS i.e. dynamic balance disturbances, and the discomfort experienced by the subjects. Dynamic balancing skill was statistically worsened during EVS. Moreover EVS evoked subjective symptoms of SMS in 17 out of the 30 subjects examined. During EVS in eyes open conditions, the subjects who encountered the strongest discomfort, presented the most disturbed dynamic balance, evidencing a relationship between the level of discomfort and the imbalance arising from EVS. This method could thus constitute an interesting basis of SMS ground-based test.

  4. Radiotherapy for Vestibular Schwannomas: A Critical Review

    International Nuclear Information System (INIS)

    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 evaluent assessments, including validated evaluations of cranial nerves V, VII, and VIII, and quality of life assessments with long-term prospective follow-up. The results from such trials will enhance the understanding of therapy outcomes and improve our ability to inform patients.

  5. Enxaqueca associada a disfunção auditivo-vestibular / Migraine associated with auditory-vestibular dysfunction

    Scientific Electronic Library Online (English)

    Renato, Cal; Fayez, Bahmad Jr.

    2008-08-01

    Full Text Available A associação de distúrbios da audição e equilíbrio com enxaqueca é reconhecida desde a Grécia antiga quando Aretaeus da Capadócia em 131 a.C., fez uma descrição precisa e com detalhes desta ocorrência durante uma crise de enxaqueca. Uma revisão ampla das manifestações otoneurológicas da enxaqueca é [...] apresentada, usando as mais recentes publicações com respeito à epidemiologia, apresentação clínica, fisiopatologia, métodos diagnósticos e manejo desta síndrome. OBJETIVO: Descrever a entidade clínica "Enxaqueca associada a Disfunção Auditivo-vestibular" no intuito de ajudar médicos otorrinolaringologistas e neurologistas no diagnóstico e no manejo clínico dessa doença. COMENTÁRIOS FINAIS: Uma forte associação existe entre sintomas otoneurológicos e enxaqueca, sendo a enxaqueca associada a disfunção auditivo-vestibular a causa mais comum de vertigem episódica espontânea (não-posicional). Os sintomas podem variar bastante entre pacientes tornando um desafio diagnóstico para o otorrinolaringologista. Esta entidade geralmente se apresenta com ataques de vertigem espontâneos ou posicionais, durando de segundos a dias com sintomas de enxaqueca associados. Uma melhor elucidação da ligação entre os mecanismos vestibulares centrais e os mecanismos da enxaqueca em si, além da descoberta de defeitos em canais iônicos em algumas causas de enxaqueca, ataxia e vertigem, podem levar a um entendimento maior da fisiopatologia da enxaqueca associada a disfunção auditivo-vestibular. Abstract in english The association between hearing and balance disorders with migraine is known since the times of the ancient Greeks, when Aretaeus from Cappadocia in 131 B.C, made an accurate and detailed description of this occurrence during a migraine episode. We present a broad review of migraine neurotological m [...] anifestations, using the most recent publications associated with epidemiology, clinical presentation, pathophysiology, diagnostic methods and treatment for this syndrome. AIM: to describe the clinical entity: "Migraine associated with auditory-vestibular dysfunction" in order to help otorhinolaryngologists and neurologists in the diagnosis and management of such disorder. FINAL REMARKS: There is a strong association between neurotological symptoms and migraine, and the auditory-vestibular dysfunction-associated migraine is the most common cause of spontaneous episodic vertigo (non-positional). Symptoms may vary broadly among patients, making it a diagnostic challenge to the otorhinolaryngologist. This entity usually presents with positional or spontaneous vertigo spells, lasting for seconds or days, associated with migraine symptoms. A better understanding of the relationship between central vestibular mechanisms and migraine mechanisms, besides the discovery of ionic channel disorders in some cases of migraine, ataxia and vertigo, may lead to a better understanding of migraine pathophysiology associated with audio-vestibular disorder.

  6. Queixas auditivas e vestibulares durante a gestação / Hearing and vestibular complaints during pregnancy

    Scientific Electronic Library Online (English)

    Paula Michele da Silva, Schmidt; Franciele da Trindade, Flores; Angela Garcia, Rossi; Aron Ferreira da, Silveira.

    2010-02-01

    Full Text Available As disfunções hormonais presentes na mulher durante a gravidez podem causar desordens vestibulares e/ou cocleares. OBJETIVO: Verificar a ocorrência de queixas auditivas e vestibulares em gestantes. MATERIAL E MÉTODO: Este é um estudo prospectivo no qual participaram 82 gestantes. Para pesquisa das q [...] ueixas auditivas e vestibulares foi aplicado às gestantes o Protocolo de Anamnese proposto por Castagno (1994). RESULTADOS: Pode-se observar que o zumbido foi a queixa auditiva mais citada (33%), sem diferença entre os trimestres gestacionais. A queixa de tontura esteve presente em 52,44% das gestantes e principalmente no primeiro trimestre gestacional. Quanto aos sintomas relacionados à tontura, no primeiro trimestre o mais frequente foi a vertigem, já no segundo trimestre gestacional foi a instabilidade e o desequilíbrio ao caminhar e no terceiro trimestre gestacional foi a instabilidade seguida da tendência a cair. A náusea é o principal sintoma associado à tontura nas gestantes, sendo mais frequente no primeiro trimestre gestacional. CONCLUSÃO: Mulheres durante a gestação referem queixas auditivas e vestibulares, principalmente tontura e zumbido. Abstract in english Hormonal dysfunctions in women during pregnancy can cause vestibular and/or cochlear disorders. AIM: to study hearing and vestibular complaints in pregnant women. MATERIAL AND METHOD: this is a prospective study. 82 pregnant women participated on this study. For hearing and vestibular complaints, a [...] questionnaire proposed by Castagno (1994) was employed. RESULTS: we could observe that tinnitus was the main auditory complaint (33%), although with no differences between the groups. Tinnitus was present among 52.44% of the pregnant women, mainly in the Group 2. According to symptoms related to dizziness, vertigo was the main auditory complaint in first trimester, whereas instability and gait unbalance were more frequent in the second trimester, and instability and tendency to fall in the third trimester. Nausea was the main symptom associated with dizziness in pregnant women, being more frequent in the first trimester of gestation. CONCLUSIONS: women during gestation have auditory and vestibular complaints, mainly dizziness and tinnitus.

  7. Vestibular contribution to the planning of reach trajectories.

    Science.gov (United States)

    Bockisch, Christopher J; Haslwanter, Thomas

    2007-09-01

    Reaching for an object while simultaneously rotating induces Coriolis and centrifugal inertial forces on the arm that require compensatory actions to maintain accuracy. We investigated whether the nervous system uses vestibular signals of head rotation to predict inertial forces. Human subjects reached in darkness to a remembered target 33 cm distant. Subjects were stationary, but experienced a strong vestibular rotation signal. We achieved this by rotating subjects at 360 degrees /s in yaw for 2 min and then stopping, and subjects reached during the 'post-rotary' period when the deceleration is interpreted by the vestibular system as a rotation in the opposite direction. Arm trajectories were straight in control trials without a rotary stimulus. With vestibular stimulation, trajectory curvature increased an average of 3 cm in the direction of the vestibular stimulation (e.g., to the right for a rightward yaw stimulus). Vestibular-induced curvature returned rapidly to normal, with an average time constant of 6 s. Movements also became longer as the vestibular stimulus diminished, and returned towards normal length with an average time constant of 5.6 s. In a second experiment we compared reaching with preferred and non-preferred hands, and found that they were similarly affected by vestibular stimulation. The reach curvatures were in the expected direction if the nervous system anticipated and attempted to counteract the presence of Coriolis forces based on the vestibular signals. Similarly, the shorter reaches may have occurred because the nervous system was attempting to compensate for an expected centrifugal force. Since vestibular stimulation also alters the perceived location of targets, vestibular signals probably influence all stages of the sensorimotor pathway transforming the desired goal of a reach into specific motor-unit innervation. PMID:17562026

  8. Plasticity of histamine H3 receptor expression and binding in the vestibular nuclei after labyrinthectomy in rat

    Directory of Open Access Journals (Sweden)

    Karlstedt Kaj

    2004-09-01

    Full Text Available Abstract Background In rat, deafferentation of one labyrinth (unilateral labyrinthectomy results in a characteristic syndrome of ocular and motor postural disorders (e.g., barrel rotation, circling behavior, and spontaneous nystagmus. Behavioral recovery (e.g., diminished symptoms, encompassing 1 week after unilateral labyrinthectomy, has been termed vestibular compensation. Evidence suggesting that the histamine H3 receptor plays a key role in vestibular compensation comes from studies indicating that betahistine, a histamine-like drug that acts as both a partial histamine H1 receptor agonist and an H3 receptor antagonist, can accelerate the process of vestibular compensation. Results Expression levels for histamine H3 receptor (total as well as three isoforms which display variable lengths of the third intracellular loop of the receptor were analyzed using in situ hybridization on brain sections containing the rat medial vestibular nucleus after unilateral labyrinthectomy. We compared these expression levels to H3 receptor binding densities. Total H3 receptor mRNA levels (detected by oligo probe H3X as well as mRNA levels of the three receptor isoforms studied (detected by oligo probes H3A, H3B, and H3C showed a pattern of increase, which was bilaterally significant at 24 h post-lesion for both H3X and H3C, followed by significant bilateral decreases in medial vestibular nuclei occurring 48 h (H3X and H3B and 1 week post-lesion (H3A, H3B, and H3C. Expression levels of H3B was an exception to the forementioned pattern with significant decreases already detected at 24 h post-lesion. Coinciding with the decreasing trends in H3 receptor mRNA levels was an observed increase in H3 receptor binding densities occurring in the ipsilateral medial vestibular nuclei 48 h post-lesion. Conclusion Progressive recovery of the resting discharge of the deafferentated medial vestibular nuclei neurons results in functional restoration of the static postural and occulomotor deficits, usually occurring within a time frame of 48 hours in rats. Our data suggests that the H3 receptor may be an essential part of pre-synaptic mechanisms required for reestablishing resting activities 48 h after unilateral labyrinthectomy.

  9. Analysis of signal processing in vestibular circuits with a novel light-emitting diodes-based fluorescence microscope.

    Science.gov (United States)

    Direnberger, Stephan; Banchi, Roberto; Brosel, Sonja; Seebacher, Christian; Laimgruber, Stefan; Uhl, Rainer; Felmy, Felix; Straka, Hans; Kunz, Lars

    2015-05-01

    Optical visualization of neural network activity is limited by imaging system-dependent technical tradeoffs. To overcome these constraints, we have developed a powerful low-cost and flexible imaging system with high spectral variability and unique spatio-temporal precision for simultaneous optical recording and manipulation of neural activity of large cell groups. The system comprises eight high-power light-emitting diodes, a camera with a large metal-oxide-semiconductor sensor and a high numerical aperture water-dipping objective. It allows fast and precise control of excitation and simultaneous low noise imaging at high resolution. Adjustable apertures generated two independent areas of variable size and position for simultaneous optical activation and image capture. The experimental applicability of this system was explored in semi-isolated preparations of larval axolotl (Ambystoma mexicanum) with intact inner ear organs and central nervous circuits. Cyclic galvanic stimulation of semicircular canals together with glutamate- and ?-aminobutyric acid (GABA)-uncaging caused a corresponding modulation of Ca(2+) transients in central vestibular neurons. These experiments revealed specific cellular properties as well as synaptic interactions between excitatory and inhibitory inputs, responsible for spatio-temporal-specific sensory signal processing. Location-specific GABA-uncaging revealed a potent inhibitory shunt of vestibular nerve afferent input in the predominating population of tonic vestibular neurons, indicating a considerable impact of local and commissural inhibitory circuits on the processing of head/body motion-related signals. The discovery of these previously unknown properties of vestibular computations demonstrates the merits of our novel microscope system for experimental applications in the field of neurobiology. PMID:25847143

  10. Facial myokymia as a presenting symptom of vestibular schwannoma.

    Directory of Open Access Journals (Sweden)

    Joseph B

    2002-07-01

    Full Text Available Facial myokymia is a rare presenting feature of a vestibular schwannoma. We present a 48 year old woman with a large right vestibular schwannoma, who presented with facial myokymia. It is postulated that facial myokymia might be due to a defect in the motor axons of the 7th nerve or due to brain stem compression by the tumor.

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

    Directory of Open Access Journals (Sweden)

    Mercier Pierre

    2009-08-01

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

  12. Vestibular vertigo in emergency neurology and cervical osteochondrosis

    Directory of Open Access Journals (Sweden)

    T S Barykova

    2010-06-01

    had acute peripheral vestibular pathology that required cerebral stroke or hemorrhage to be ruled out according to clinical data in most cases. Intermittent, recurrent, short-term vestibular crisis in the examined group of patients is temporarily or clinically unrelated to an exacerbation of cervical osteochondrosis.

  13. Vestibular influences on autonomic cardiovascular control in humans

    Science.gov (United States)

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

    1998-01-01

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

  14. 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.

  15. Assessment of auditory and vestibular functions after vestibular neurectomy for Menière's disease.

    Science.gov (United States)

    Kubo, T; Doi, K; Koizuka, I; Takeda, N; Sugiyama, N; Yamada, K; Kohmura, E; Hayakawa, T

    1995-03-01

    Fourteen patients (12 Meniere's disease, one delayed endolymphatic hydrops and one labyrinthitis) suffering from intractable vertigo were treated with retrosigmoid vestibular neurectomy (RSVN) in our institute. Dizziness was controlled completely in all patients. Hearing was preserved in 91.7% of the cases with pure tone threshold deteriorating by more than 10 dB in one case, remained unchanged in 10 cases and improved in one case during long term observation. Substantial decrease of tinnitus was observed in 78.6%. Vestibular compensation was chronologically analyzed with a stabilometer, ENG and vestibular rotation test (0.01-0.64 Hz). Vestibular compensation under static conditions was accomplished within 2 weeks, except for spontaneous nystagmus measured in the dark. Asymmetry of vestibulo-ocular reflex was noted 2 weeks after the operation but had disappeared after 4 weeks. However, for over 2 years the VOR time constant remained lower (4.3-5.2 s) than the pre-operative value (8.2 s). Electro-cochleogram (ECoG) was recorded before and after RSVN. The -SP/AP ratio tended to increase after RSVN in the operated ear, though there was no change in the contralateral ear. The efferent olivo-cochlear bundle was thought to play a potential role in this increase of the -SP/AP ratio. PMID:7610792

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

    Science.gov (United States)

    Barry, Susan R.; Mueller, S. Alyssa

    1995-01-01

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

  17. Anodal vestibular stimulation does not suppress vestibular reflexes in human subjects.

    Science.gov (United States)

    Bacsi, Ann M; Colebatch, James G

    2003-06-01

    Anodal current applied to the vestibular apparatus has previously been found to inhibit discharge from irregular vestibular afferents in squirrel monkeys. We wished to investigate whether anodal currents applied over the mastoid processes of human subjects would significantly reduce ongoing vestibular activity and thereby the size of galvanic-evoked vestibulospinal reflexes, measured by soleus electromyogram. Nine subjects were tested, of whom six subjects (five females, one male) provided data for the final analysis. Tonic anodal current was applied over one mastoid at 0 (baseline), 2, 4, 6 and 8 mA. The cathode was placed at C7. Superimposed on each intensity of tonic current were separate, short anodal currents of 4 mA, duration 20 ms, presented as 128 stimuli to the same side, and used to test vestibular responsiveness. These trials were then repeated with the anode overlying the contralateral mastoid. Short latency (SL) and medium latency (ML) reflexes were measured from the right soleus muscle. All six subjects used in the final analysis had readily identifiable reflexes to all stimuli. One-way ANOVA revealed no significant difference in the magnitude of the SL ( P=0.99) or ML ( P=0.96) components of the vestibulospinal reflexes across the group. Despite surface anodal currents of up to 8 mA, there was no consistent effect on the size of galvanic-evoked vestibulospinal reflexes. As 8 mA is close to the maximum intensity tolerated by volunteer subjects, our results indicate that anodal current applied over the mastoids is unlikely to be a useful means of suppressing vestibular function in human subjects. PMID:12739094

  18. Bead Neuron

    Science.gov (United States)

    Dr. Janet M Dubinsky (University of Minnesota Neuroscience)

    2008-11-06

    Using string and beads of different colors, students will make bead neurons and use them as models to understand the specialized cellular structure and function of neurons and how neurons communicate with each other.

  19. Symptomatic recovery in Miller Fisher Syndrome parallels vestibular-perceptual and not vestibular-ocular reflex function

    Directory of Open Access Journals (Sweden)

    BarryMSeemungal

    2011-02-01

    Full Text Available Unpleasant visual symptoms including oscillopsia and dizziness may occur when there is unexpected motion of the visual world across the subject’s retina (‘retinal-slip’ as in an acute spontaneous nystagmus or on head movement with an acute ophthalmoplegia. In contrast, subjects with chronic ocular dysmotility, e.g. congenital nystagmus or CPEO (chronic progressive external ophthalmoplegia, are typically symptom free. The adaptive processes that render chronic patients asymptomatic are obscure but may include a suppression of oscillopsia perception as well as an increased tolerance to perceived oscillopsia. Such chronic asymptomatic patients display an attenuation of vestibular-mediated angular velocity perception, implying a possible contributory role in the adaptive process. In order to assess causality between symptoms, signs (i.e. eye-movements and vestibular perceptual function, we prospectively assessed symptom ratings and ocular-motor and perceptual vestibular function, in a patient with acute but transient ophthalmoplegia due to Miller Fisher Syndrome (as a model of visuo-vestibular adaptation. The data show that perceptual measures of vestibular function display a significant attenuation as compared to ocularmotor measures during the acute, symptomatic period. Perhaps significantly, both symptomatic recovery and normalisation of vestibular perceptual function were delayed and then occurred in a parallel fashion. This is the first report showing that symptomatic recovery of visuo-vestibular symptoms is better paralleled by vestibular-perceptual testing than VOR (vestibular ocular reflex measures. The findings may have implications for the understanding of patients with chronic vestibular symptoms where VOR testing is often unhelpful.

  20. GABAB RECEPTORS CONTRIBUTE TO THE RESTORATION OF BALANCE DURING VESTIBULAR COMPENSATION IN MICE

    OpenAIRE

    Heskin-sweezie, Raquel; Titley, Heather K.; Baizer, Joan S.; Broussard, Dianne M.

    2010-01-01

    Following unilateral vestibular damage (UVD), vestibular compensation restores both static and dynamic vestibular reflexes. The cerebellar cortex provides powerful GABAergic inhibitory input to the vestibular nuclei which is necessary for compensation. Metabotropic GABA type B (GABAB) receptors in the vestibular nuclei are thought to be involved. However, the contribution of GABAB receptors may differ between static and dynamic compensation. We tested static and dynamic postural reflexes and ...

  1. Signal detection theory and vestibular thresholds: I. Basic theory and practical considerations

    OpenAIRE

    Merfeld, Daniel M.

    2011-01-01

    Detection theory has been applied to the measurement of vestibular thresholds and vestibular sensory integration. Yet, a formal detection theory analysis of vestibular responses has not been published. Such a de novo analysis seems warranted because the vestibular system has characteristics that differ from other sensory systems, which impacts the application of detection theory. For example, the physical stimuli evoking vestibular responses are typically bidirectional (e.g., leftward/rightwa...

  2. Adaptive plasticity in vestibular influences on cardiovascular control

    Science.gov (United States)

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

    2000-01-01

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

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

    Science.gov (United States)

    Héroux, Martin E; Law, Tammy C. Y.; Fitzpatrick, Richard C.; Blouin, Jean-Sébastien

    2015-01-01

    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. PMID:25894558

  4. Betahistine treatment in managing vertigo and improving vestibular compensation: clarification.

    Science.gov (United States)

    Lacour, Michel

    2013-01-01

    Betahistine dihydrochloride (betahistine) is currently used in the management of vertigo and vestibular pathologies with different aetiologies. The main goal of this review is to clarify the mechanisms of action of this drug, responsible for the symptomatic relief of vertigo and the improvement of vestibular compensation. The review starts with a brief summary recalling the role of histamine as a neuromodulator/neurotransmitter in the control of the vestibular functions, and the role of the histaminergic system in vestibular compensation. Then are presented data recorded in animal models demonstrating that betahistine efficacy can be explained by mechanisms targeting the histamine receptors (HRs) at three different levels: the vascular tree, with an increase of cochlear and vestibular blood flow involving the H1R; the central nervous system, with an increase of histamine turnover implicating the H3R, and the peripheral labyrinth, with a decrease of vestibular input implying the H3R/H4R. Clinical data from vestibular loss patients show the impact of betahistine treatment for the long-term control of vertigo, improvement of balance and quality of life that can be explained by these mechanisms of action. However, two conditions, at least, are required for reaching the betahistine therapeutic effect: the dose and the duration of treatment. Experimental and clinical data supporting these requirements are exposed in the last part of this review. PMID:24177346

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

    Science.gov (United States)

    Bush, Matthew L; Dougherty, William

    2015-08-01

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

  6. Função vestibular no acidente vascular cerebral do território carotídeo / Vestibular function in carotid territory stroke patients

    Scientific Electronic Library Online (English)

    Anna Paula Batista de Ávila, Pires; Marcia Maiumi, Fukujima; Fernando Freitas, Ganança; Letícia de Moraes, Aquino; Maurício Malavasi, Ganança; Heloisa Helena, Caovilla.

    2013-02-01

    Full Text Available Pacientes após Acidente Vascular Cerebral (AVC) podem apresentar sintomas otoneurológicos. OBJETIVO: Avaliar a função vestibular de pacientes com antecedente pessoal de AVC no território carotídeo. Desenho científico: estudo de coorte histórica com corte transversal. MÉTODO: Quarenta pacientes foram [...] submetidos à anamnese, exame otorrinolaringológico, Dizziness Handicap Inventory e vectoeletronistagmografia. RESULTADOS: Anormalidades discretas dos movimentos sacádicos foram encontradas em 20 pacientes (50,0%); nove referiram desequilíbrio e um tontura. O ganho do rastreio pendular foi anormal em 17 casos (42,5%); seis referiram desequilíbrio e um tontura. Preponderância direcional anormal do nistagmoperrotatório ocorreu em dois casos (5,0%), que referiram desequilíbrio. A prova calórica identificou três casos (7,5%) com predomínio labiríntico anormal e dois (5,0%) com preponderância direcional anormal do nistagmo; os cinco casos relataram desequilíbrio. Dos 11 pacientes que não referiram manifestações de alteração do equilíbrio corporal, 10 apresentaram alterações nos movimentos sacádicos e no rastreio pendular e um apresentou exame vestibular normal. CONCLUSÃO: Pacientes com antecedente pessoal de AVC no território carotídeo podem apresentar tontura ou desequilíbrio corporal e sinais de comprometimento da motilidade ocular e da função vestibular. Abstract in english Stroke patients may present otoneurological symptoms. OBJECTIVE: To assess the vestibular function of subjects with a history of carotid territory stroke. METHOD: This historical cohort cross sectional study enrolled 40 patients; subjects answered the Dizziness Handicap Inventory, were interviewed a [...] nd submitted to ENT examination and vectorelectronystagmography. RESULTS: Mild saccadic movement anomalies were seen in 20 patients (50.0%); nine complained of imbalance and dizziness. Abnormal smooth pursuit gain was seen in 17 cases (42.5%); six subjects reported imbalance and one complained of dizziness. Abnormal directional preponderance during rotational nystagmus was seen in two cases (5.0%), who also reported imbalance. Three patients (7.5%) and two subjects (5.0%) were found to have abnormal labyrinthine predominance and abnormal nystagmus directional preponderance respectively; all five individuals reported imbalance. Ten of the 11 patients without complaints of disordered balance had altered saccadic and smooth pursuit eye movements, while one had unaltered vestibular function. CONCLUSION: Patients with a history of carotid territory stroke may suffer from dizziness or imbalance and present signs of compromised eye motility and vestibular function.

  7. 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. PMID:18584162

  8. STANDARDIZATION OF VESTIBULAR EVOKED MYOGENIC POTENTIALS

    Directory of Open Access Journals (Sweden)

    Ufuk Derinsu

    2009-01-01

    Full Text Available Objectives: The purpose of this study is to determine the normative data for vestibular-evoked myogenic potentials (VEMP to use in differential diagnosis.Materials and Methods: We recorded vestibular-evoked myogenic potentials in 32 voluntaries (16 men and 16 women. Electrodes were placed as 1-channel montage: active electrode to the midpoint of the ipsilateral Sternocleidomastoid muscle (SCM, referance electrode to the lower part of the ipsilateral SCM and ground electrode to the forehead. 1000 Hz tone burst stimulus was used.Results: There was no significant difference between male and female subjects and, no significant interaural difference for P13-N23 latency values. P13-N23 latency and amplitude values were determined at 105 dB, 100 dB, 95 dB, 90 dB and 85 dB nHL. The mean VEMP threshold was 91,875 dB nHL.Conclusion: Standard deviation was small for P13-N23 latency values, whereas was large for amplitüte values. It was accepted that the latency values could be used for differential diagnosis.

  9. Effectiveness of vestibular exercise in acute vertigo

    International Nuclear Information System (INIS)

    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)

  10. Frequência de alteração vestibular em bombeiros militares de Alagoas / Frequency of vestibular disorder in military firefighters from Alagoas

    Scientific Electronic Library Online (English)

    Ana Carla Lima, Barbosa; Ilka do Amaral, Soares; Elizângela Dias, Camboim.

    1443-14-01

    Full Text Available OBJETIVOS: investigar a frequência de alterações vestibulares em bombeiros de Alagoas e suas queixas. MÉTODOS: realizaram-se anamnese e avaliação audiológica, desclassificando da amostra os sujeitos com perda auditiva. Em seguida foi realizada a manobra de Dix-Hallpike e vectoeletronistagmogra [...] fia. Aplicou-se o Teste Qui-Quadrado e Exato de Fisher para análise estatística, com significância de 5% (p=0,050). RESULTADOS: compuseram a amostra 26 sujeitos do gênero masculino (86,7%) e 4 feminino (13,3%), com idade variando entre 24 e 35 anos. Destes, 13 sujeitos (43,4%) apresentaram exame vestibular normal, enquanto os demais (56,6%) apresentaram alteração na prova calórica, com maior ocorrência de disfunção vestibular periférica seguida de disfunção vestibular periférica deficitária unilateral. Não houve diferença estatisticamente significante quanto à presença de alteração vestibular nem quanto à classificação dessas alterações. Comprovou-se significante diferença para queixa de tontura entre os gêneros, sendo o feminino mais propenso a apresentá-la. Não houve diferença estatisticamente significante quanto à queixa de tontura entre as faixas etárias avaliadas, havendo, entretanto, uma tendência maior para os indivíduos de idade mais elevada a apresentarem. Não houve relação estatisticamente significante entre disfunção vestibular e queixas de tontura, manifestações auditivas nem antecedentes patológicos. CONCLUSÕES: não foi encontrada uma relação estatisticamente relevante entre o grupo estudado e a alteração vestibular. Todavia, entre os bombeiros que apresentaram alteração, houve maior ocorrência de disfunção vestibular periférica seguida de disfunção vestibular periférica deficitária unilateral, sem diferença estatisticamente significante entre elas. Os bombeiros apresentaram queixas de tontura, manifestações auditivas e antecedentes patológicos sem relação estatisticamente significante com as disfunções vestibulares identificadas. Abstract in english PURPOSES: to investigate the frequency of vestibular disorders in firefighters working in Alagoas and their complaints. METHODS: we performed otoneurologic interviews and audiological evaluation, discarding the sample subjects with abnormal results. The valid sample was underwent the maneuver Di [...] x-Hallpike and vectoelectronystagmography. We used the Chi-square test and Fisher Exact test for statistical analysis, with significance level of 5% (p = 0.050). RESULTS: the sample consisted by 26 male (86.7%) and 4 female subjects (13.3%) with aged between 24 and 35 years. Of these, were found 43.4% results normal and 56.6% showed abnormalities in the caloric test, with a higher incidence of peripheral vestibular dysfunction followed by unilateral peripheral vestibular deficit dysfunction. There were no statistically significant differences in the presence of vestibular disorders or in the classification of these pathologies. Was perceived effective difference for dizziness between genders, with females more likely to present it. There was no statistically significant difference regarding dizziness between the age groups, with a tendency for older subjects present it more. There was no statistically significant relationship between vestibular disorder and complaints of dizziness, auditory manifestations or history of disease. CONCLUSIONS: there was a higher incidence of peripheral vestibular dysfunction followed by unilateral peripheral vestibular deficit dysfunction, without statistically significant difference between them. The examined firefighters complained of dizziness, auditory manifestations and pathological history, but without statistically significant relationship with vestibular disorders.

  11. The modified ampullar approach for vestibular implant surgery: Feasibility and its first application in a human with a long-term vestibular loss

    Directory of Open Access Journals (Sweden)

    RaymondVan De Berg

    2012-02-01

    Conclusion: The modified ampullar approach provides safe access to the ampullae using as minimally invasive surgery as possible. For the first time in a human with long-term bilateral vestibular areflexia, it is shown that the VOR can be evoked by ampullar stimulation, even when there has been no vestibular function for almost twenty years. This approach should be considered in vestibular surgery, as it provides safe access to one of the most favourable stimulus locations for development of a vestibular implant.

  12. Ongoing cell death and immune influences on regeneration in the vestibular sensory organs

    Science.gov (United States)

    Warchol, M. E.; Matsui, J. I.; Simkus, E. L.; Ogilive, J. M.

    2001-01-01

    Hair cells in the vestibular organs of birds have a relatively short life span. Mature hair cells appear to die spontaneously and are then quickly replaced by new hair cells that arise from the division of epithelial supporting cells. A similar regenerative mechanism also results in hair cell replacement after ototoxic damage. The cellular basis of hair cell turnover in the avian ear is not understood. We are investigating the signaling pathways that lead to hair cell death and the relationship between ongoing cell death and cell production. In addition, work from our lab and others has demonstrated that the avian inner ear contains a resident population of macrophages and that enhanced numbers of macrophages are recruited to sites of hair cells lesions. Those observations suggest that macrophages and their secretory products (cytokines) may be involved in hair cell regeneration. Consistent with that suggestion, we have found that treatment with the anti-inflammatory drug dexamethasone reduces regenerative cell proliferation in the avian ear, and that certain macrophage-secreted cytokines can influence the proliferation of vestibular supporting cells and the survival of statoacoustic neurons. Those results suggest a role for the immune system in the process of sensory regeneration in the inner ear.

  13. Termination of vestibulospinal fibers arising from the spinal vestibular nucleus in the mouse spinal cord.

    Science.gov (United States)

    Liang, H; Bácskai, T; Paxinos, G

    2015-05-21

    The present study investigated the vestibulospinal system which originates from the spinal vestibular nucleus (SpVe) with both retrograde and anterograde tracer injections. We found that fluoro-gold (FG) labeled neurons were found bilaterally with a contralateral predominance after FG injections into the upper lumbar cord. Anterogradely labeled fibers from the rostral SpVe traveled in the medial part of the ventral funiculus ipsilaterally and the dorsolateral funiculus bilaterally in the cervical cord. They mainly terminated in laminae 5-8, and 10 of the ipsilateral spinal cord. The contralateral side had fewer fibers and they were found in laminae 6-8, and 10. In the thoracic cord, fibers were also found to terminate in bilateral intermediolateral columns. In the lumbar and lower cord, fibers were mainly found in the dorsolateral funiculus bilaterally and they terminated predominantly in laminae 3-7 contralaterally. Anterogradely labeled fibers from the caudal SpVe did not travel in the medial part of the ventral funiculus but in the dorsolateral funiculus bilaterally. They mainly terminated in laminae 3-8 and 10 contralaterally. The present study is the first to describe the termination of vestibulospinal fibers arising from the SpVe in the spinal cord. It will lay the anatomical foundation for those who investigate the physiological role of vestibulospinal fibers and potentially target these fibers during rehabilitation after stroke, spinal cord injury, or vestibular organ injury. PMID:25791229

  14. Diagnóstico e tratamento das principais síndromes vestibulares Diagnosis and treatment of the most frequent vestibular syndromes

    OpenAIRE

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

    2005-01-01

    Os objetivos deste estudo foram identificar as síndromes vestibulares mais comuns nos ambulatórios de vertigem, suas características clínicas e semiológicas, e observar a resposta ao tratamento específico. Foram estudados retrospectivamente 515 pacientes atendidos em ambulatórios de duas instituições e avaliados aspectos da anamnese, exame físico e a resposta ao tratamento. As síndromes mais freqüentes foram: vertigem de posicionamento paroxística benigna (VPPB) (28,5%), vertigem...

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

    Directory of Open Access Journals (Sweden)

    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, dificultando a recuperação dos mesmos, que geralmente apresentam diminuição da massa muscular.

  16. Contribution of vestibular nerve irregular afferents to viewing distance-related changes in the vestibulo-ocular reflex.

    Science.gov (United States)

    Chen-Huang, C; McCrea, R A

    1998-03-01

    The contribution of irregular vestibular afferents to viewing distance-related changes in the angular vestibulo-ocular reflex (AVOR) and combined angular and linear VOR (CVOR) was studied in squirrel monkeys trained to fixate earth-stationary targets that were near (10 cm) and distant (90-170 cm) from their eyes. Perilymphatic anodal galvanic currents were used to reversibly silence irregular vestibular afferents for periods of 4-5 s during the AVOR and CVOR evoked by 0.5- to 4-Hz sinusoidal rotations (6-20 degrees/s peak velocity) or 250-400 degrees/s2 acceleration steps. The direction and magnitude of linear translation were changed by positioning the monkeys at different distances off the axis of turntable rotation. The effects of irregular afferent galvanic ablation (GA) on viewing distance-related changes in the AVOR were studied in four animals. Viewing distance-related changes in the AVOR could not always be evoked and were frequently small in amplitude. GA reduced viewing distance-related change in the AVOR by an average of 64% when it was present. Thus vestibular irregular afferents appear to play an important and necessary role in viewing distance-related changes in the AVOR - on those occasions when the changes occur. Viewing distance-related changes in the CVOR were large and reliably evoked. GA had very little effect on the gain or phase of viewing distance-related changes in the CVOR, although the viewing distance-related CVOR responses of individual central vestibular neurons were affected. We conclude that irregular afferents probably contribute to central signal processing related to both the AVOR and the CVOR, but the signals carried by these afferents are only essential for viewing distance-related changes in AVOR. PMID:9521542

  17. Vestibular impairment in patients with Charcot-Marie-Tooth disease

    OpenAIRE

    Poretti, A; Palla, A.; Tarnutzer, A.A.; Petersen, J A; Weber, K P.; Straumann, D.; Jung, H H

    2013-01-01

    OBJECTIVE: This case-control study aimed to determine whether the imbalance in Charcot-Marie-tooth (CMT) disease is caused only by reduced proprioceptive input or whether the involvement of the vestibular nerve is an additional factor. METHODS: Fifteen patients with CMT disease (aged 48 ± 17 years; 8 women) underwent cervical vestibular-evoked myogenic potentials, which reflect otolith-spinal reflex function, and quantitative horizontal search-coil head-impulse testing, which assesses the h...

  18. Morphological analysis of the vestibular aqueduct by computerized tomography images

    International Nuclear Information System (INIS)

    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 mm2 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 mm2, 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 betweeen groups of children and adults or between groups of both genders were not statistically significant

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

    OpenAIRE

    Mercier Pierre; Hutin Émilie; Lamothe Vincent; Simoneau Martin; Teasdale Normand; Blouin Jean

    2009-01-01

    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 pro...

  20. Responses of Thoracic Spinal Interneurons to Vestibular Stimulation

    OpenAIRE

    Miller, D. M.; Reighard, D. A.; Mehta, A. S.; Kalash, R.; Yates, B. J.

    2009-01-01

    Vestibular influences on outflow from the spinal cord are largely mediated via spinal interneurons, although few studies have recorded interneuronal activity during labyrinthine stimulation. The present study determined the responses of upper thoracic interneurons of decerebrate cats to electrical stimulation of the vestibular nerve or natural stimulation of otolith organs and the anterior and posterior semicircular canals using rotations in vertical planes. A majority of thoracic interneuron...

  1. Morphological analysis of the vestibular aqueduct by computerized tomography images

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Sergio Ricardo [Morphology and Genetics Department, Sao Paulo Federal University-Paulista Medical School, Disciplina de Anatomia Descritiva e Topografica, Rua Botucatu, 740-Edificio Leitao da Cunha, CEP 04023-900, Vila Clementino, Sao Paulo (Brazil)]. E-mail: sergioanat.morf@epm.br; Smith, Ricardo Luiz [Morphology and Genetics Department, Sao Paulo Federal University-Paulista Medical School, Disciplina de Anatomia Descritiva e Topografica, Rua Botucatu, 740-Edificio Leitao da Cunha, CEP 04023-900, Vila Clementino, Sao Paulo (Brazil); Isotani, Sadao [Institute of Physics, University of Sao Paulo, Sao Paulo (Brazil); Alonso, Luis Garcia [Morphology and Genetics Department, Sao Paulo Federal University-Paulista Medical School, Disciplina de Anatomia Descritiva e Topografica, Rua Botucatu, 740-Edificio Leitao da Cunha, CEP 04023-900, Vila Clementino, Sao Paulo (Brazil); Anadao, Carlos Augusto [Otorhinolaryngology Department, Sao Paulo Federal University-Paulista Medical School, Sao Paulo (Brazil); Prates, Jose Carlos [Morphology and Genetics Department, Sao Paulo Federal University-Paulista Medical School, Disciplina de Anatomia Descritiva e Topografica, Rua Botucatu, 740-Edificio Leitao da Cunha, CEP 04023-900, Vila Clementino, Sao Paulo (Brazil); Lederman, Henrique Manoel [Image Diagnosis Department, Sao Paulo Federal University-Paulista Medical School, Sao Paulo (Brazil)

    2007-01-15

    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{sup 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{sup 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.

  2. Asymmetric vestibular evoked myogenic potentials in unilateral Menière patients

    OpenAIRE

    Kingma, C. M.; Wit, H. P.

    2010-01-01

    Vestibular evoked myogenic potentials (VEMPs) were measured in 22 unilateral Menière patients with monaural and binaural stimulation with 250 and 500 Hz tone bursts. For all measurement situations significantly lower VEMP amplitudes were on average measured at the affected side compared to the unaffected side. Unilateral Menière patients have, in contrast to normal subjects, asymmetric VEMPs, indicating a permanently affected vestibular (most likely otolith) system at the side of hearing l...

  3. Rizatriptan reduces vestibular-induced motion sickness in migraineurs

    OpenAIRE

    Furman, Joseph M.; Marcus, Dawn A.; Balaban, Carey D.

    2010-01-01

    A previous pilot study suggested that rizatriptan reduces motion sickness induced by complex vestibular stimulation. In this double-blind, randomized, placebo-controlled study we measured motion sickness in response to a complex vestibular stimulus following pretreatment with either rizatriptan or a placebo. Subjects included 25 migraineurs with or without migraine-related dizziness (23 females) aged 21–45 years (31.0 ± 7.8 years). Motion sickness was induced by off-vertical axis rotati...

  4. Visual and proprioceptive interaction in patients with bilateral vestibular loss?

    OpenAIRE

    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 ...

  5. Avaliação e reabilitação vestibular no indivíduo idoso / Vestibular assessment and rehabilitation in the elderly

    Scientific Electronic Library Online (English)

    Natália Daniela Rezende, Mirallas; Marta Helena Souza, De Conti; Alberto, De Vitta; Ruy, Laurenti; Sandra de Oliveira, Saes.

    Full Text Available Considerando a necessidade de propiciar melhora na qualidade de vida do idoso e a elevada incidência de queixas relacionadas aos transtornos de equilíbrio nessa faixa etária, este estudo teve como objetivo avaliar o equilíbrio estático e dinâmico de indivíduos idosos com queixas de tonturas e verifi [...] car a eficácia da reabilitação vestibular (RV) individualizada, por meio da comparação do escore do Dizziness Handicap Inventory - DHI (questionário de handicap), antes do início da RV e no momento da alta ou, no máximo, após 12 sessões de reabilitação. Participaram da pesquisa 11 indivíduos de faixa etária acima ou igual a 60 anos, submetidos a diagnóstico otoneurológico, composto de avaliação otorrinolaringológica, audiológica, vectoeletronistagmografia e exames complementares, quando necessário. As principais queixas foram tonturas, desequilíbrio e quedas. Todos os pacientes tiveram diagnóstico de síndrome vestibular periférica, sendo dez irritativos e um deficitário unilateral. Pode-se observar que a maioria dos casos apresentou desaparecimento de seus sintomas ou significativa diminuição em suas manifestações, salvo dois pacientes que apresentavam doenças associadas ou não seguiram as orientações dadas. A RV individualizada mostrou ser um procedimento terapêutico eficaz na terceira idade e o DHI um instrumento importante no acompanhamento da evolução do paciente. Abstract in english Considering the need to improve elderly's quality of life the high incidence of complaints related to equilibrium disturbance in this age group, this study aimed to evaluate the static and dynamic equilibrium of elderly who complain of dizziness and verify the individualized vestibular rehabilitatio [...] n, comparing dizziness handicap inventory - DHI (handicap questionnaire) score before starting to exercise and at the moment of discharge or after 12 rehabilitation sessions. Eleven individuals aged sixty years or more participated in this research, undergoing otoneurologic diagnostic, composed by otorrinilaringologic assessment, audiologic, electron vector tomography an extras exams if needed. The main complaints were dizziness, lack of equilibrium and droppings. All patients were diagnosed with peripheral vestibular syndrome, being ten irritative and one one-sided. It can be noticed that in most cases the symptoms disappeared or decreased. Except for two patients who presented diseases associated or had not followed the orientations. The individualized vestibular rehabilitation has proved to be an effective therapeutic procedure in elderly and DHI an important tool in following patient's evolution.

  6. 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 review. METHODS: We reviewed papers on the influence of mobile phones on auditory and vestibular systems from Lilacs and Medline databases, published from 2000 to 2005, and also materials available in the Internet. RESULTS: Studies concerning mobile phone radiation and risk of developing an acoustic neuroma have controversial results. Some authors did not see evidences of a higher risk of tumor development in mobile phone users, while others report that usage of analog cellular phones for ten or more years increase the risk of developing the tumor. Acute exposure to mobile phone microwaves do not influence the cochlear outer hair cells function in vivo and in vitro, the cochlear nerve electrical properties nor the vestibular system physiology in humans. Analog hearing aids are more susceptible to the electromagnetic interference caused by digital mobile phones. CONCLUSION: there is no evidence of cochleo-vestibular lesion caused by cellular phones.

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

    Scientific Electronic Library Online (English)

    Aracy Pereira Silveira, Balbani; Jair Cortez, Montovani.

    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 ve [...] stibulococlear 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. Abstract in english 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 sur [...] face absorb the radiofrequency energy. AIM: literature review on the influence of cellular phones on hearing and balance. STUDY DESIGN: systematic review. METHODS: We reviewed papers on the influence of mobile phones on auditory and vestibular systems from Lilacs and Medline databases, published from 2000 to 2005, and also materials available in the Internet. RESULTS: Studies concerning mobile phone radiation and risk of developing an acoustic neuroma have controversial results. Some authors did not see evidences of a higher risk of tumor development in mobile phone users, while others report that usage of analog cellular phones for ten or more years increase the risk of developing the tumor. Acute exposure to mobile phone microwaves do not influence the cochlear outer hair cells function in vivo and in vitro, the cochlear nerve electrical properties nor the vestibular system physiology in humans. Analog hearing aids are more susceptible to the electromagnetic interference caused by digital mobile phones. CONCLUSION: there is no evidence of cochleo-vestibular lesion caused by cellular phones.

  8. Arreflexia pós-calórica bilateral: aplicabilidade clínica da reabilitação vestibular

    Directory of Open Access Journals (Sweden)

    Bittar Roseli Saraiva Moreira

    2004-01-01

    Full Text Available A perda bilateral da função vestibular é rara em pacientes com vertigem e desequilíbrio, porém os sintomas muitas vezes são incapacitantes e seu tratamento é tema controverso na literatura. OBJETIVO: Nosso objetivo foi avaliar e descrever a resposta clínica de pacientes com distúrbio do equilíbrio corporal secundário à arreflexia vestibular pós-calórica bilateral, documentada pela eletronistagmografia, submetidos à Reabilitação Vestibular. FORMA DE ESTUDO: Retrospectivo, inclui um desenho de descrição de casos. MÉTODO: Foram avaliadas as respostas de 8 pacientes portadores de arreflexia pós-calórica bilateral submetidos à Reabilitação Vestibular, observando-se a relação entre os resultados de exame e sintomas pré e pós-tratamento. A avaliação da resposta clínica foi feita por meio de escala analógico-visual. RESULTADOS: Após a Reabilitação Vestibular, 7 (87,5% dos 8 pacientes submetidos à terapia apresentaram melhora clínica. CONCLUSÃO: embora não seja esperada melhora completa do equilíbrio corporal, a Reabilitação Vestibular é uma terapia eficaz na recuperação desses pacientes.

  9. Vestibular findings associated with chronic noise induced hearing impairment.

    Science.gov (United States)

    Shupak, A; Bar-El, E; Podoshin, L; Spitzer, O; Gordon, C R; Ben-David, J

    1994-11-01

    Histological and functional derangements of the vestibular system have been reported in laboratory animals exposed to high levels of noise. However, clinical series describe contradictory results with regard to vestibular disturbances in industrial workers and military personnel suffering from noise induced hearing loss (NIHL). The purpose of the present study was to evaluate vestibular function in a group of subjects with documented NIHL, employing electronystagmography (ENG) and the smooth harmonic acceleration (SHA) test. Subjects were 22 men suffering from NIHL and 21 matched controls. Significantly lower vestibulo-ocular reflex gain (p = 0.05), and a tendency towards decreased caloric responses were found in the study group. No differences in the incidence of vertigo symptoms, spontaneous, positional and positioning nystagmus, directional preponderance and canal paresis in the ENG, or the SHA test phase and asymmetry parameters were observed between the groups. These results demonstrated a symmetrical centrally compensated decrease in the vestibular end organ response which is associated with the symmetrical hearing loss measured in the study group. Statistically significant correlations were found between the average hearing loss, the decrement in the average vestibulo-ocular reflex gain (p = 0.01), and ENG caloric lateralization (p = 0.02). These correlations might indicate a single mechanism for both cochlear and vestibular noise-induced injury. The results imply subclinical, well compensated malfunction of the vestibular system associated with NIHL. PMID:7879613

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

    Science.gov (United States)

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

    1995-01-01

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

  11. Avaliação do efeito da cafeína no teste vestibular Evaluation of the caffeine effect in the vestibular test

    Directory of Open Access Journals (Sweden)

    Lilian Felipe

    2005-12-01

    Full Text Available Há controvérsias sobre a interferência da cafeína no teste vestibular. O café é a fonte mais rica em cafeína. Enquanto em alguns serviços os pacientes são orientados a suspender a ingestão de café 24 a 48 horas antes da realização do teste, outros não consideram necessária a suspensão da ingestão dessa bebida. OBJETIVO: Avaliar o efeito da cafeína no resultado do teste vestibular. FORMA DE ESTUDO: clínico com coorte transversal. MATERIAL E MÉTODO: Estudo comparativo, transversal, pareado. O teste vestibular foi realizado em duplicidade, com intervalo máximo de cinco dias entre um e outro exame. No primeiro teste, os pacientes foram orientados a não ingerir café 24 horas antes do exame; no segundo teste, os pacientes foram orientados a beber café como de costume. Todos os participantes tinham indicação clínica de se submeter ao teste vestibular e tinham o hábito de tomar café. RESULTADOS: Participaram do estudo 19 mulheres com idade média de 49,5 anos. O consumo médio de café foi de três xícaras por dia. As queixas de ansiedade e cefaléia foram associadas ao teste realizado com suspensão do café. Não houve diferença estatisticamente significante nos resultados dos exames realizados com e sem ingestão de café. CONCLUSÃO: A ingestão moderada de café não interferiu no resultado do teste vestibular. Considerando ser recomendável que o paciente esteja tranqüilo ao se submeter ao teste vestibular e que a meia-vida da cafeína é de apenas seis horas, sugerimos que a orientação para a suspensão súbita e completa da ingestão moderada de café antes do teste vestibular para os indivíduos habituados à ingestão diária seja reavaliada.Exist controversy about the interference of the caffeine in the vestibular test. Coffee is the richest source of caffeine. While in some services, the patients were orient to suspend the ingestion of caffeine 24 to 48 hours before the vestibular test, other not consider the suspension of this drink necessary. AIM: To evaluate the effect of caffeine in the vestibular test result. STUDY DESIGN: clinical with transversal cohort. MATERIAL AND METHOD: Seccional and matched research. The vestibular test was performed twice in the same patient, with five days interval between the exams. In the first test, the patient did not drink coffee 24 hours before the exam; in the second, the patient drunk coffee as usual. All of the participants had clinical indication for vestibular test and were used to drinking coffee. RESULTS: Nineteen women, medium age of 49,5 years, participated. The average coffee consumption was three cups per day. The complaints of anxiety and headache were associated with the submission to the vestibular test without coffee. The exams were not statistically different comparing the results of the tests performed with and without the coffee ingestion. CONCLUSION: The moderate ingestion of coffee was not shown to interfere in the results of the vestibular test. Considering that it is recommended that the patient be calm to be submitted to the vestibular test and that the half-life of the caffeine is only of six hours, we suggest that the orientation of complete and abrupt drinking coffee suspension of moderate dose before the vestibular test for the individuals used to daily drinking coffee be reevaluated.

  12. Avaliação do efeito da cafeína no teste vestibular / Evaluation of the caffeine effect in the vestibular test

    Scientific Electronic Library Online (English)

    Lilian, Felipe; Lilia Correia, Simões; Denise Utsch, Gonçalves; Patrícia Cotta, Mancini.

    2005-12-01

    Full Text Available Há controvérsias sobre a interferência da cafeína no teste vestibular. O café é a fonte mais rica em cafeína. Enquanto em alguns serviços os pacientes são orientados a suspender a ingestão de café 24 a 48 horas antes da realização do teste, outros não consideram necessária a suspensão da ingestão de [...] ssa bebida. OBJETIVO: Avaliar o efeito da cafeína no resultado do teste vestibular. FORMA DE ESTUDO: clínico com coorte transversal. MATERIAL E MÉTODO: Estudo comparativo, transversal, pareado. O teste vestibular foi realizado em duplicidade, com intervalo máximo de cinco dias entre um e outro exame. No primeiro teste, os pacientes foram orientados a não ingerir café 24 horas antes do exame; no segundo teste, os pacientes foram orientados a beber café como de costume. Todos os participantes tinham indicação clínica de se submeter ao teste vestibular e tinham o hábito de tomar café. RESULTADOS: Participaram do estudo 19 mulheres com idade média de 49,5 anos. O consumo médio de café foi de três xícaras por dia. As queixas de ansiedade e cefaléia foram associadas ao teste realizado com suspensão do café. Não houve diferença estatisticamente significante nos resultados dos exames realizados com e sem ingestão de café. CONCLUSÃO: A ingestão moderada de café não interferiu no resultado do teste vestibular. Considerando ser recomendável que o paciente esteja tranqüilo ao se submeter ao teste vestibular e que a meia-vida da cafeína é de apenas seis horas, sugerimos que a orientação para a suspensão súbita e completa da ingestão moderada de café antes do teste vestibular para os indivíduos habituados à ingestão diária seja reavaliada. Abstract in english Exist controversy about the interference of the caffeine in the vestibular test. Coffee is the richest source of caffeine. While in some services, the patients were orient to suspend the ingestion of caffeine 24 to 48 hours before the vestibular test, other not consider the suspension of this drink [...] necessary. AIM: To evaluate the effect of caffeine in the vestibular test result. STUDY DESIGN: clinical with transversal cohort. MATERIAL AND METHOD: Seccional and matched research. The vestibular test was performed twice in the same patient, with five days interval between the exams. In the first test, the patient did not drink coffee 24 hours before the exam; in the second, the patient drunk coffee as usual. All of the participants had clinical indication for vestibular test and were used to drinking coffee. RESULTS: Nineteen women, medium age of 49,5 years, participated. The average coffee consumption was three cups per day. The complaints of anxiety and headache were associated with the submission to the vestibular test without coffee. The exams were not statistically different comparing the results of the tests performed with and without the coffee ingestion. CONCLUSION: The moderate ingestion of coffee was not shown to interfere in the results of the vestibular test. Considering that it is recommended that the patient be calm to be submitted to the vestibular test and that the half-life of the caffeine is only of six hours, we suggest that the orientation of complete and abrupt drinking coffee suspension of moderate dose before the vestibular test for the individuals used to daily drinking coffee be reevaluated.

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

    OpenAIRE

    DELLA SANTINA, CHARLES C.; Migliaccio, Americo A; Hayden, Russell; Melvin, Thuy-Anh; FRIDMAN, GENE Y.; Chiang, Bryce; Davidovics, Natan S.; Dai, Chenkai; Carey, John P; Minor, Lloyd B; Anderson, Iee-Ching; Park, HongJu; Lyford-Pike, Sofia; TANG, SHAN

    2010-01-01

    Bilateral loss of vestibular sensation can disable individuals whose vestibular hair cells are injured by ototoxic medications, infection, Ménière’s disease or other insults to the labyrinth including surgical trauma during cochlear implantation. Without input to vestibulo-ocular and vestibulo-spinal reflexes that normally stabilize the eyes and body, affected patients suffer blurred vision during head movement, postural instability, and chronic disequilibrium. While individuals with some...

  14. Paroxismia vestibular: estudo clínico e tratamento de oito pacientes / Vestibular paroxysmia: clinical study and treatment of eight patients

    Scientific Electronic Library Online (English)

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

    2005-09-01

    Full Text Available A paroxismia vestibular é uma síndrome de compressão do VIII nervo craniano e foi denominada inicialmente por Janetta "vertigem posicional incapacitante". Esta síndrome é caracterizada por episódios curtos de vertigem, zumbido, déficit vestibular e auditivo. A RM pode mostrar compressão do VIII nerv [...] o por vasos da fossa posterior, como a artéria basilar, artéria vertebral, artéria cerebelar inferior anterior, artéria cerebelar inferior posterior. A paroxismia vestibular pode ser tratada com terapia medicamentosa tais como carbamazepina, fenitoína ou gabapentina, ou com descompressão microvascular do VIII nervo. Este estudo descreve oito pacientes com paroxismia vestibular. Quatro deles mostraram também sinais clínicos sugerindo compressão do V e/ou VII nervos. Sete pacientes tratados com carbamazepina tiveram melhora significativa da vertigem e zumbido. Abstract in english Vestibular paroxysmia is a syndrome of cross-compression of the VIII cranial nerve and was first described by Jannetta who used the term "disabling positional vertigo". This syndrome is characterized by brief attacks of vertigo, tinnitus, vestibular and auditory deficits. MRI may show the VIII nerve [...] compression from vessels in the posterior fossa, such as the basilar, vertebral, anterior-inferior cerebellar or the posterior-inferior cerebellar arteries. Vestibular paroxysmia may be treated either with medical therapy, such as carbamazepine, phenytoin or gabapentin or with the microvascular decompression of the VIII nerve. This study describes eight patients with vestibular paroxysmia. Four of them showed also clinical signs suggesting cross-compression of the V and/or VII nerve. Seven patients treated with carbamazepine had significant improvement of vertigo and tinnitus.

  15. Changes in TNF?, NF?B and MnSOD protein in the vestibular nuclei after unilateral vestibular deafferentation

    OpenAIRE

    Lacour Michel; Bernard-Demanze Laurence; Manrique Christine; Liberge Martine

    2010-01-01

    Abstract Background Unilateral vestibular deafferentation results in strong microglial and astroglial activation in the vestibular nuclei (VN) that could be due to an inflammatory response. This study was aimed at determining if markers of inflammation are upregulated in the VN after chemical unilateral labyrinthectomy (UL) in the rat, and if the inflammatory response, if any, induces the expression of neuroprotective factors that could promote the plasticity mechanisms involved in the vestib...

  16. Vestibular rehabilitation: clinical benefits to patients with Parkinson's disease / Reabilitação vestibular: utilidade clínica em pacientes com doença de Parkinson

    Scientific Electronic Library Online (English)

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

    2009-06-01

    Full Text Available OBJETIVO: Avaliar a eficácia dos exercícios de reabilitação vestibular (RV) por meio de avaliação pré e pós-aplicação da versão brasileira do questionário Dizziness Handicap Inventory (DHI). MÉTODO: Estudou-se 12 pacientes e realizaram-se os seguintes procedimentos: anamnese, avaliação otorrinolarin [...] gológica, vestibular e aplicação do DHI pré e pós RV. RESULTADOS: Do ponto de vista clínico, o tremor de repouso e a instabilidade postural subjetiva foram às queixas motoras mais freqüentes associadas às queixas de vertigem em 12 casos (100%); no exame vestibular, todos os pacientes apresentaram anormalidades, com freqüência das síndromes vestibulares periféricas deficitárias uni e bilaterais em 10 casos (83,3%); houve melhora significativa dos aspectos físico, funcional e emocional do DHI após a realização da RV. CONCLUSÃO: A RV seguindo o protocolo de Cawthorne e Cooksey mostrou-se útil no manejo de queixas subjetivas de diversos aspectos avaliados neste protocolo. Abstract in english OBJECTIVE: To evaluate the effectiveness of the vestibular rehabilitation (VR) exercises by means of an assessment before and after the application of the Brazilian version of the Dizziness Handicap Inventory (DHI) questionnaire. METHOD: Twelve patients were studied, the following procedures were ca [...] rried out: anamnesis, otorhinolaryngological and vestibular evaluation, and the application of the DHI before and after the VR. RESULTS: Clinically resting tremors and subjective postural instability were the motor complaints most frequently associated with complaints of vertigo in 12 cases (100%); in the vestibular exam, all the patients presented abnormalities, frequently from the uni and bilateral peripheral vestibular deficiency syndromes in 10 cases (83.3%); there was significant improvement in the physical, functional and emotional aspects of the DHI after the completion of the VR. CONCLUSION: The VR following the Cawthorne and Cooksey protocol were shown to be useful in managing subjective complaints of several aspects evaluated in this protocol.

  17. 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??1 (TGF??1) interleukin (IL)?1?, IL?6 and tumor necrosis factor?? (TNF??), 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??1, IL?1? and IL?6 exhibited increased expression in human vestibular schwannoma tissue compared with normal vestibular nerve samples. TNF?? was weakly expressed in Schwann cells, confirming that a lower level of this cytokine is involved in the proliferation of Schwann cells. Neoplastic Schwann cells produce pro?inflammatory cytokines that may act in an autocrine manner, stimulating cellular proliferation. In addition, the increased expression of VEGF in vestibular schwannoma compared with that in normal vestibular nerve tissue, suggests that this factor may induce neoplastic growth via the promotion of angiogenesis. The present findings suggest that inflammation may promote angiogenesis and consequently contribute to tumor progression. In conclusion, the results of the present study indicated that VEGF and pro?inflammatory cytokines may be potential therapeutic targets in vestibular schwannoma. Further studies are necessary to confirm the involvement of these factors in the growth of neoplasms and to develop inhibitors of pro?inflammatory cytokines as a potential treatment option in the future. PMID:25738867

  18. Correlação entre resultado do exame vestibular e queixas psicológicas autorrelatadas de pacientes com sintomas vestibulares / Correlation between vestibular test results and self-reported psychological complaints of patients with vestibular symptoms

    Scientific Electronic Library Online (English)

    Léia Gonçalves, Gurgel; Michelle Ramos, Dourado; Taís de Campos, Moreira; Adriana Jung, Serafini; Isabela Hoffmeister, Menegotto; Caroline Tozzi, Reppold; Cristina Loureiro Chaves, Soldera.

    2012-02-01

    Full Text Available Fatores cognitivos e emocionais podem afetar o equilíbrio, portanto, condições psiquiátricas são comuns em pacientes otoneurológicos. O tratamento dado ao sujeito vertiginoso pode ser mais influenciado pelo sofrimento e comportamento da doença do que pela gravidade da patologia orgânica. OBJETIVO: E [...] ste estudo teve como objetivo verificar a associação entre os resultados do exame vestibular e queixa psicológica autorrelatada, em indivíduos atendidos no ano de 2009, no serviço de audiologia de um hospital em Porto Alegre. MATERIAL E MÉTODO: Foi realizado um estudo retrospectivo, descritivo-exploratório, consultando-se a base de dados dos softwares VecWin® e VecWin® 2 da marca Neurograff®. Foram investigados os resultados do exame vestibular, as queixas referentes aos sintomas psicológicos relatados espontaneamente e idade, sexo e queixa de vertigem e/ou tontura. O trabalho foi realizado em três etapas: agrupamento, exclusão/inclusão e quantificação. CONCLUSÃO: A faixa etária da amostra, o sexo e a presença ou ausência de vertigem e/ou tontura não foram variáveis de influência sobre o resultado do exame vestibular. Houve associação significativa entre a presença de queixa psicológica autorrelatada e o resultado normal do exame vestibular. Assim, é fundamental que os profissionais deem atenção às questões psicológicas relatadas pelo indivíduo na ocasião da anamnese vestibular. Abstract in english Cognitive and emotional factors may affect balance; psychiatric conditions are a common component in patient dizziness. The treatment of patients with vertigo may be affected to a greater degree by the suffering due to this disease than by the severity of organic changes. OBJECTIVE: This study aimed [...] to investigate associations between vestibular test results and self-reported psychological complaints in patients evaluated during 2009 in an audiology unit at a hospital in Porto Alegre. METHODS: We conducted a retrospective, descriptive-exploratory study of data taken from a database of the software VecWin® and VecWin® 2, developed by Neurograff®. We investigated vestibular test results, reports of psychological symptoms reported spontaneously, and information such as age, sex and the presence of vertigo and/or dizziness. This study consisted of three steps: clustering, exclusion/inclusion and quantification. CONCLUSION: Age and gender and the presence or absence of vertigo and/or dizziness were not variables that influenced the outcomes of vestibular testing. There was a significant association between the presence of self-reported psychological complaints and normal vestibular test results. Thus, it is crucial that professionals pay attention to psychological issues reported by patients when the vestibular history is taken.

  19. Reabilitação vestibular com realidade virtual na ataxia espinocerebelar / Vestibular rehabilitation with virtual reality in spinocerebellar ataxia

    Scientific Electronic Library Online (English)

    Bianca Simone, Zeigelboim; Sandra Dias de, Souza; Heidi, Mengelberg; Hélio Afonso Ghizoni, Teive; Paulo Breno Noronha, Liberalesso.

    2013-06-01

    Full Text Available O objetivo do estudo foi verificar os benefícios da reabilitação vestibular (RV) com realidade virtual, por meio de avaliação pré e pós-aplicação da Escala de Equilíbrio de Berg (EEB), em quatro casos de ataxia espinocerebelar (AEC). Os casos foram submetidos aos seguintes procedimentos: anamnese, i [...] nspeção otológica, avaliação vestibular e aplicação da EEB pré e pós-RV, com a realidade virtual representada por meio da utilização de jogos do equipamento Wii Fit. Os casos retratam quatro pacientes com diagnóstico genético de AEC (dois tipo 2, um tipo 3 e um em investigação), sendo três do gênero feminino e um do gênero masculino, na faixa etária de 30 a 62 anos. Os pacientes referiram sintomas otoneurológicos e, no exame vestibular, observou-se a presença de nistagmo semiespontâneo com características centrais, ausência de nistagmo pós-rotatório, hiporreflexia e preponderância direcional do nistagmo assimétrica à prova calórica. Nos casos 1 e 2, os pacientes referiram melhora na coordenação dos movimentos e do equilíbrio corporal, independente do escore na EEB ter demonstrado médio risco para queda, antes e após a realização dos exercícios. No caso 3, o paciente apresentou melhora do escore na EEB, bem como do equilíbrio, apresentando baixo risco para queda. O caso 4 não evidenciou melhora na avaliação após a execução dos exercícios. Este estudo de caso demonstrou a possibilidade da aplicação dos exercícios de RV com estímulos virtuais na AEC, com melhora da coordenação motora e do equilíbrio postural. Abstract in english The purpose of this study was to verify the benefits of the vestibular rehabilitation (VR) with virtual reality through the assessment before and after the application of the Berg Balance Scale (BBS) in four cases of spinocerebellar ataxia (SCA). The cases were underwent the following procedures: an [...] amnesis, ear inspection, vestibular assessment and application of the BBS before and after VR with virtual reality using games from Wii Fit device. The cases describe four patients that were diagnosed with genetically inherited SCA (two type 2, one type 3 and one still under investigation), three of them were female and one was male, with ages ranging from 30 to 62 years. The patients presented otoneurological symptoms and the vestibular test showed the presence of semi-spontaneous nystagmus, absence of post-rotational nystagmus, hyporeflexia, and asymmetric directional preponderance of the nystagmus in the caloric test. Patients from cases 1 and 2 have showed an improvement in motor coordination and in body balance, even though the score presented by the BBS had demonstrated medium risk for falling before and after the exercises. In case 3, the patient's loss of balance and BBS score have improved, presenting low risk of falling; whereas the patient in case 4 did not show any improvement in the assessment after the exercises. This case study shows the applicability of VR exercises with virtual stimuli in SCA with improved motor coordination and postural balance.

  20. 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 significant impact on development of vestibular SR delivery systems to aid recovery of function in astronauts after long-duration spaceflight or in people with balance disorders.

  1. Frequency response of human vestibular reflexes characterized by stochastic stimuli.

    Science.gov (United States)

    Dakin, Christopher J; Son, Gregory M Lee; Inglis, J Timothy; Blouin, Jean-Sébastien

    2007-09-15

    Stochastic vestibular stimulation (SVS) can be used to study the postural responses to unpredictable vestibular perturbations. The present study seeks to determine if stochastic vestibular stimulation elicits lower limb muscular responses and to estimate the frequency characteristics of these vestibulo-motor responses in humans. Fourteen healthy subjects were exposed to unpredictable galvanic currents applied on their mastoid processes while quietly standing (+/-3 mA, 0-50 Hz). The current amplitude and stimulation configuration as well as the subject's head position relative to their feet were manipulated in order to determine that: (1) the muscle responses evoked by stochastic currents are dependent on the amplitude of the current, (2) the muscle responses evoked by stochastic currents are specific to the percutaneous stimulation of vestibular afferents and (3) the lower limb muscle responses exhibit polarity changes with different head positions as previously described for square-wave galvanic vestibular stimulation (GVS) pulses. Our results revealed significant coherence (between 0 and 20 Hz) and cumulant density functions (peak responses at 65 and 103 ms) between SVS and the lower limbs' postural muscle activity. The polarity of the cumulant density functions corresponded to that of the reflexes elicited by square-wave GVS pulses. The SVS-muscle activity coherence and time cumulant functions were modulated by current amplitude, electrode position and head orientation with respect to the subject's feet. These findings strongly support the vestibular origin of the lower limb muscles evoked by SVS. In addition, specific frequency bandwidths in the stochastic vestibular signal contributed to the early (12-20 Hz) and late components (2-10 Hz) of the SVS-evoked muscular responses. These frequency-dependent SVS-evoked muscle responses support the view that the biphasic muscle response is conveyed by two distinct physiological processes. PMID:17640935

  2. Vestibular rehabilitation ameliorates chronic dizziness through the SIRT1 axis

    Directory of Open Access Journals (Sweden)

    Chung-Lan Kao

    2014-03-01

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

  3. Click-evoked responses in vestibular afferents in rats.

    Science.gov (United States)

    Zhu, Hong; Tang, Xuehui; Wei, Wei; Mustain, William; Xu, Youguo; Zhou, Wu

    2011-08-01

    Sound activates not only the cochlea but also the vestibular end organs. Research on this phenomenon led to the discovery of the sound-evoked vestibular myogenic potentials recorded from the sternocleidomastoid muscles (cervical VEMP, or cVEMP). Since the cVEMP offers simplicity and the ability to stimulate each labyrinth separately, its values as a test of human vestibular function are widely recognized. Currently, the cVEMP is interpreted as a test of saccule function based on the assumption that clicks primarily activate the saccule. However, sound activation of vestibular end organs other than the saccule has been reported. To provide the neural basis for interpreting clinical VEMP testing, we employed the broadband clicks used in clinical VEMP testing to examine the sound-evoked responses in a large sample of vestibular afferents in Sprague-Dawley rats. Recordings were made from 924 vestibular afferents from 106 rats: 255 from the anterior canal (AC), 202 from the horizontal canal (HC), 177 from the posterior canal (PC), 207 from the superior vestibular nerve otolith (SO), and 83 from the inferior nerve otolith (IO). Sound sensitivity of each afferent was quantified by computing the cumulative probability of evoking a spike (CPE). We found that clicks activated irregular afferents (normalized coefficient of variation of interspike intervals >0.2) from both the otoliths (81%) and the canals (43%). The order of end organ sound sensitivity was SO = IO > AC > HC > PC. Since the sternocleidomastoid motoneurons receive inputs from both the otoliths and the canals, these results provide evidence of a possible contribution from both of them to the click-evoked cVEMP. PMID:21613592

  4. Ocular vestibular evoked myogenic potentials in normal-hearing adults

    Directory of Open Access Journals (Sweden)

    Mohammad Kamali

    2012-06-01

    Full Text Available Background and Aim: Ocular vestibular-evoked myogenic potential (oVEMP is a novel vestibular function test. This short-latency response can be recorded through contracting extraocular muscles by high-intensity acoustic stimulation and can be used to evaluate contralateral ocular-vestibular reflex. The aim of this study was to record and compare the amplitude, latency, asymmetry ratio and occurrence percentage of oVEMP (n10 and cervical VEMP (p13 responses in a group of normal adult subjects.Methods: We carried out a cross-sectional study on 20 adult subjects' mean age 22.18 years, SD=2.19 with normal hearing sensitivity and no history of vestibular diseases. oVEMP and cVEMP responses in both ears were recorded using air conducted stimuli 500 Hz short tone burst, 95 dB nHL via insert earphone and compared.Results: cVEMP was recorded in all subjects but oVEMP was absent in two subjects. Mean amplitude and latency were 140.77 ?v and 15.56 ms in p13; and 3.18 ?v and 9.32 ms in n10. There were statistically significant differences between p13 and n10 amplitudes (p<0.001.Conclusion: This study showed that occurrence percentage and amplitude of oVEMP were less than those of cVEMP. Since these two tests originate from different sections of vestibular nerve, we can consider them as parallel vestibular function tests and utilize them for evaluation of vestibular disorders.

  5. Avaliação do tratamento dos distúrbios vestibulares na criança através da posturografia dinâmica computadorizada: resultados preliminares

    OpenAIRE

    Medeiros Ítalo R.T.; Bittar Roseli S. M.; Pedalini Maria Elisabete B.; Lorenzi Maria Cecília; Kii Márcia A.; Formigoni Lázaro G.

    2003-01-01

    OBJETIVO: o objetivo desta investigação foi avaliar a posturografia como método de acompanhamento de crianças com vestibulopatia periférica, tratadas com reabilitação vestibular, estabelecendo sua correlação com a evolução clínica dos pacientes. MÉTODOS: dez crianças (seis meninos e quatro meninas) portadoras de afecções vestibulares periféricas, submetidas à reabilitação vestibular como forma de tratamento, tiveram sua evolução clínica avaliada através de uma anamnese...

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

    OpenAIRE

    Heinze, Barbara; Swanepoel, De Wet; Hofmeyr, Louis Murray

    2011-01-01

    INTRODUCTION: Disorders of the auditory and vestibular system are often associated with human immunodeficiency virus infection and acquired immunodeficiency syndrome. However, the extent and nature of these vestibular manifestations are unclear. OBJECTIVE: To systematically review the current peer-reviewed literature on vestibular manifestations and pathology related to human immunodeficiency virus and acquired immunodeficiency syndrome. METHOD: Systematic review of peer-review...

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

    International Nuclear Information System (INIS)

    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.

  8. Neural basis for eye velocity generation in the vestibular nuclei of alert monkeys during off-vertical axis rotation

    Science.gov (United States)

    Reisine, H.; Raphan, T.; Cohen, B. (Principal Investigator)

    1992-01-01

    Activity of "vestibular only" (VO) and "vestibular plus saccade" (VPS) units was recorded in the rostral part of the medial vestibular nucleus and caudal part of the superior vestibular nucleus of alert rhesus monkeys. By estimating the "null axes" of recorded units (n = 79), the optimal plane of activation was approximately the mean plane of reciprocal semicircular canals, i.e., lateral canals, left anterior-right posterior (LARP) canals or right anterior-left posterior (RALP) canals. All units were excited by rotation in a direction that excited a corresponding ipsilateral semicircular canal. Thus, they all displayed a "type I" response. With the animal upright, there were rapid changes in firing rates of both VO and VPS units in response to steps of angular velocity about a vertical axis. The units were bidirectionally activated during vestibular nystagmus (VN), horizontal optokinetic nystagmus (OKN), optokinetic after-nystagmus (OKAN) and off-vertical axis rotation (OVAR). The rising and falling time constants of the responses to rotation indicated that they were closely linked to velocity storage. There were differences between VPS and VO neurons in that activity of VO units followed the expected time course in response to a stimulus even during periods of drowsiness, when eye velocity was reduced. Firing rates of VPS units, on the other hand, were significantly reduced in the drowsy state. Lateral canal-related units had average firing rates that were linearly related to the bias or steady state level of horizontal eye velocity during OVAR over a range of +/- 60 deg/s. These units could be further divided into two classes according to whether they were modulated during OVAR. Non-modulated units (n = 5) were VO types and all modulated units (n = 5) were VPS types. There was no significant difference between the bias level sensitivities relative to eye velocity of the units with and without modulation (P > 0.05). The modulated units had no sustained change in firing rate in response to static head tilts and their phases relative to head position varied from unit to unit. The phase did not appear to be linked to the modulation of horizontal eye velocity during OVAR. The sensitivities of unit activity to eye velocity were similar during all stimulus modalities despite the different gains of eye velocity vs stimulus velocity during VN, OKN and OVAR. Therefore, VO and VPS units are likely to carry an eye velocity signal related to velocity storage.(ABSTRACT TRUNCATED AT 400 WORDS).

  9. 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

    2014-04-24

    IMPORTANCE 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. OBJECTIVE 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). DESIGN, SETTING, AND PARTICIPANTS 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. INTERVENTIONS Survey questionnaire. MAIN OUTCOMES AND MEASURES 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. RESULTS 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?BVD (P?BVD and UVD incurred estimated mean (range) annual economic burdens of $13?019 ($0-$48?830) and $3531 ($0-$48?442) per patient, respectively. CONCLUSIONS AND RELEVANCE Bilateral vestibular deficiency significantly decreases quality of life and imposes substantial economic burdens on individuals and society. These results underscore the limits of adaptation and compensation in BVD. Furthermore, they quantify the potential benefits of prosthetic restoration of vestibular function both to these individuals and to society. PMID:24763518

  10. Vein of the vestibular aqueduct in the gerbil.

    Science.gov (United States)

    Kimura, R S; Trehey, J A; Hutta, J

    1996-01-01

    The vein of the vestibular aqueduct in the gerbil runs along the lateral side of the endolymphatic duct, deviates from this course to enter the middle ear cavity, and connects with the lateral sinus. In 20 animals, the vein of the vestibular aqueduct was obliterated by drilling from the middle ear side. Histopathology of these specimens after 2 months' survival revealed consistent sensory cell atrophy in the posterior canal cristae, frequent loss of sensory cells in a small superior portion of the macula sacculi and in the basal end of the cochlea, and fibrosis and osteogenesis in the three semicircular canals. The endolymphatic sacs contained colloidal substances in some specimens which were otherwise normal. Endolymphatic hydrops was absent except in some specimens which showed additional surgical damage to the endolymphatic sac and canals. The blocked vein re-opened occasionally and connected with the vessel formed in new bone from which it attached to the lateral sinus. The sensory cell degeneration and canal fibrosis reflects the pattern of blood drainage by the vein of the vestibular aqueduct. Vascular disorder in the vestibular labyrinth initiates vestibular symptoms; however, it will not produce endolymphatic hydrops unless function of the endolymphatic sac is impaired. PMID:8820349

  11. The bilateral central vestibular system: its pathways, functions, and disorders.

    Science.gov (United States)

    Dieterich, Marianne; Brandt, Thomas

    2015-04-01

    The bilateral anatomical organization of the vestibular system provides three functional advantages: optimal differentiation of head motion and orientation, sensory substitution of a unilateral peripheral failure, and central compensation of a peripheral or central vestibular tone imbalance. The structure is based on bilaterally ascending and descending pathways and at least four crossings: three in the brain stem and one in the cortex. The resulting sensorimotor functions can be subdivided into three major groups: (1) reflexive control of gaze, head, and body in three spatial planes (yaw, pitch, roll) at the brain stem/cerebellar level; (2) perception of self-motion and control of voluntary movement and balance at the cortical/subcortical level; and (3) higher vestibular cognitive functions (e.g., spatial memory and navigation). The bilateral representation of the vestibular system in multiple multisensory cortical areas and the vestibular dominance of the nondominant hemisphere raise the question of how one global percept of motion and orientation in space is formed. PMID:25581203

  12. Nasal Vestibular Huge Keratoacanthoma: An Unusual Site

    Directory of Open Access Journals (Sweden)

    N. Yazdani

    2009-01-01

    Full Text Available Keratoacanthoma (KA is a rapidly growing, low-grade neoplasm of pilo-sebaceous and hair follicle units which most often appears on the sun-exposed skin of the middle aged and older persons with multiple or localized occurrence. This tumor is dome-shaped nodule with a central keratinous plug. The etiology of this tumor is not obvious. Exposure to excessive sunlight is the most frequently noted responsible factor in the etiology of KA. About 80% of the tumors occur on the face. The histological features of the KA are often very similar to those of a cutaneous squamous cell carcinoma; however, the tumor structure usually provides a basis for their difference. There are many unusual cases of keratoacanthoma reported regarding site, size or other specifications. In this study, we excised a mass of nasal vestibule, a site far away sun-exposure. To our knowledge, this is the first case of nasal vestibular keratoacanthoma. For a clinician and a pathologist it is important to consider a benign lesion like Keratoacanthoma (KA in the differential diagnosis of ulcerated nasal lesions and pay attention to differ it from Squamous Cell Carcinoma (SCC which has a different and aggressive management.

  13. A afecção vestibular infantil: estudo da orientação espacial Vestibular disorders in childhood: study of spatial disorders

    Directory of Open Access Journals (Sweden)

    Elaine Shizue Novalo

    2007-12-01

    Full Text Available OBJETIVO: verificar como é a percepção do espaço na criança com vertigem periférica. MÉTODOS: estudo prospectivo de 18 crianças, com faixa etária de três a 15 anos, sob acompanhamento no Ambulatório de Otorrinolaringologia / Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. A percepção espacial foi avaliada por meio de atividade livre (desenho livre e dirigida (blocos lógicos e teste de Frostig. Das 18 crianças avaliadas, nove constituíram o grupo estudo (diagnóstico de vestibulopatia e queixa de tontura e nove constituíram o grupo controle (sem história de vestibulopatia e sem queixa de tontura. Foram excluídas crianças que apresentassem comprometimento de Sistema Nervoso Central que interferisse na interpretação da avaliação. Os resultados obtidos foram comparados entre o grupo estudo e controle qualitativamente. RESULTADOS: em relação ao desenho livre, 77,78% das crianças do grupo controle e 55,55% do grupo estudo utilizaram o papel inteiro. Quanto à proporção dos objetos, 100% das crianças do grupo controle e apenas 48,86% das crianças do grupo estudo desenharam com proporção adequada. Nos blocos lógicos, houve maior dificuldade do grupo estudo. No teste de Frostig, foi observada diferença significativa do ponto de vista clínico entre os grupos quanto ao Quociente Perceptual. CONCLUSÃO: as crianças com vestibulopatia, ao desenhar, aproveitaram o papel de forma menos homogênea, com maior dificuldade para desenhar figuras humanas e proporção inadequada entre os objetos. Desta forma, é importante que seja realizado o diagnóstico de vestibulopatia precocemente, para que o tratamento/reabilitação seja iniciado e sintomas, como a desorientação espacial, não influenciem na aprendizagem da criança.PURPOSE: to check how is the child's spatial perception in vestibular disorder. METHODS: prospective study of 18 children, between 3 and 15-year old, under treatment in Ambulatório de Otorrinolaringologia/Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Space perception was assessed through a free activity (free drawing and two directed activities: the Frostig test and an adaptation of the Token Test. Of the 18 evaluated children, 09 composed the study group (diagnosed as having a vestibular disorder and 09 composed the control group (with no history of vestibular disorder or dizziness. Children who showed central nervous system impairments were excluded. RESULTS: in relation to the free drawing, 77.78% of the control group and 55.55% in the study group used the whole sheet of paper provided. Regarding the proportion of the objects, 100% of the control group showed an adequate proportion in their drawings and it was found in 48.86% of the study group. In the adapted Token Test, the study group showed a major difficulty. In the Frostig test, a small difference between the groups in the Perceptual quotient was observed. CONCLUSION: the children with vestibular disorders, while drawing, used the sheet of paper in a less homogeneous way, showing more difficulty to draw human pictures and an inadequate proportion among the drawn objects. In this way, it is important that the vestibular diagnosis should be done the earliest possible in order to anticipate the treatment/rehabilitation. This may prevent the impairment of spatial perception from negatively influencing the learning process.

  14. A afecção vestibular infantil: estudo da orientação espacial / Vestibular disorders in childhood: study of spatial disorders

    Scientific Electronic Library Online (English)

    Elaine Shizue, Novalo; Maria Valéria Schmidt, Goffi-Gomez; Ítalo Roberto Torres de, Medeiros; Maria Elisabete Bovino, Pedalini; Rosa Maria Rodrigues dos, Santos.

    2007-12-01

    Full Text Available OBJETIVO: verificar como é a percepção do espaço na criança com vertigem periférica. MÉTODOS: estudo prospectivo de 18 crianças, com faixa etária de três a 15 anos, sob acompanhamento no Ambulatório de Otorrinolaringologia / Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo [...] . A percepção espacial foi avaliada por meio de atividade livre (desenho livre) e dirigida (blocos lógicos e teste de Frostig). Das 18 crianças avaliadas, nove constituíram o grupo estudo (diagnóstico de vestibulopatia e queixa de tontura) e nove constituíram o grupo controle (sem história de vestibulopatia e sem queixa de tontura). Foram excluídas crianças que apresentassem comprometimento de Sistema Nervoso Central que interferisse na interpretação da avaliação. Os resultados obtidos foram comparados entre o grupo estudo e controle qualitativamente. RESULTADOS: em relação ao desenho livre, 77,78% das crianças do grupo controle e 55,55% do grupo estudo utilizaram o papel inteiro. Quanto à proporção dos objetos, 100% das crianças do grupo controle e apenas 48,86% das crianças do grupo estudo desenharam com proporção adequada. Nos blocos lógicos, houve maior dificuldade do grupo estudo. No teste de Frostig, foi observada diferença significativa do ponto de vista clínico entre os grupos quanto ao Quociente Perceptual. CONCLUSÃO: as crianças com vestibulopatia, ao desenhar, aproveitaram o papel de forma menos homogênea, com maior dificuldade para desenhar figuras humanas e proporção inadequada entre os objetos. Desta forma, é importante que seja realizado o diagnóstico de vestibulopatia precocemente, para que o tratamento/reabilitação seja iniciado e sintomas, como a desorientação espacial, não influenciem na aprendizagem da criança. Abstract in english PURPOSE: to check how is the child's spatial perception in vestibular disorder. METHODS: prospective study of 18 children, between 3 and 15-year old, under treatment in Ambulatório de Otorrinolaringologia/Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Space perception w [...] as assessed through a free activity (free drawing) and two directed activities: the Frostig test and an adaptation of the Token Test. Of the 18 evaluated children, 09 composed the study group (diagnosed as having a vestibular disorder) and 09 composed the control group (with no history of vestibular disorder or dizziness). Children who showed central nervous system impairments were excluded. RESULTS: in relation to the free drawing, 77.78% of the control group and 55.55% in the study group used the whole sheet of paper provided. Regarding the proportion of the objects, 100% of the control group showed an adequate proportion in their drawings and it was found in 48.86% of the study group. In the adapted Token Test, the study group showed a major difficulty. In the Frostig test, a small difference between the groups in the Perceptual quotient was observed. CONCLUSION: the children with vestibular disorders, while drawing, used the sheet of paper in a less homogeneous way, showing more difficulty to draw human pictures and an inadequate proportion among the drawn objects. In this way, it is important that the vestibular diagnosis should be done the earliest possible in order to anticipate the treatment/rehabilitation. This may prevent the impairment of spatial perception from negatively influencing the learning process.

  15. Doença vestibular em cães: 81 casos (2006-2013) / Vestibular disease in dogs: 81 cases (2006-2013)

    Scientific Electronic Library Online (English)

    Rafael O., Chaves; Diego V., Beckmann; Bruna, Copat; Fernando W., Souza; Andrei K., Fabretti; Lucas A., Gomes; Rafael A., Fighera; Alexandre, Mazzanti.

    2014-12-01

    Full Text Available De 2006 a 2013 foram diagnosticados 81 casos de doença vestibular canina no serviço de rotina em neurologia de um hospital veterinário universitário do sul do Brasil. Desses, aproximadamente dois terços foram diagnosticados com doença vestibular central (DVC) e cerca de um terço como doença vestibul [...] ar periférica (DVP). Cães com raça definida foram mais acometidos que aqueles sem raça definida, principalmente Dachshund (DVP) e Boxer (DVC). Os principais sinais clínicos observados, tanto na DVP quanto na DVC, incluíram: inclinação de cabeça, ataxia vestibular e estrabismo ventral ou ventrolateral. Deficiência proprioceptiva, disfunção dos nervos cranianos V-XII e alteração de nível de consciência foram vistos apenas em casos de DVC, já a ausência de reflexo palpebral ocorreu apenas em casos de DVP. Doenças inflamatórias/infecciosas, principalmente cinomose e otite bacteriana, foram as condições mais comumente associadas à DVC e à DVP, respectivamente. Esse artigo estabelece os aspectos epidemiológicos (sexo, idade e raça) e a prevalência dos sinais clínicos observados em cães com doença vestibular na Região Central do Rio Grande do Sul, discute a utilização dos achados clínicos no diagnóstico correto e na diferenciação entre DVC e DVP, e define quais as principais doenças responsáveis pela ocorrência dessas duas síndromes clínicas. Abstract in english Eighty-one cases of vestibular disease in dogs were diagnosed by the neurology service in a veterinary teaching hospital in southern Brazil from 2006 to 2013. Approximately 2/3 of these cases were interpreted as central vestibular disease (CVD) with the remaining cases being considered as peripheral [...] vestibular disease (PVD). Pure breed dogs, especially Dachshunds (PVD) and Boxers (CVD) were more affected than mixed breed dogs. The main clinical signs observed in cases of CVD and PVD included head tilt, vestibular ataxia, and ventral or ventrolateral strabismus. Proprioceptive deficits, cranial nerve V-XII dysfunction, and changes in the levels of conscience were observed only in cases of CVD, whereas absence of palpebral reflex occurred only in cases of PVD. Inflammatory or infectious diseases, especially canine distemper and bacterial otitis were the most commonly observed conditions associated with CVD and PVD, respectively. This article establishes the epidemiology (sex, age, and breed) and prevalence of clinical signs related to canine vestibular disease in the Central Rio Grande do Sul State; discusses the use of the clinical findings in the correct diagnosis and differentiation between CVD and PVD; and defines the main specific diseases responsible for the occurrence of CVD and PVD in dogs.

  16. [The present status of vestibular testing (author's transl)].

    Science.gov (United States)

    Minnigerode, B

    1977-02-01

    Proceeding from the standard aims of every vestibular test, modern fine-quantitative investigatory methods with or without electronystagmographic recording in opposition to the systematic search for spontaneous and provoked nystagmus are presented with a view to their value for medical practice. Examination of spontaneous nystagmus and provoked nystagmus including the fistula symptom and coarse-quantitative excitability tests still represents the most important and most profitable part of the vestibular investigation. For modern research methods standardization of nomenclature and restriction of their plurality are as necessary as a method, which takes in not only single parameters but the whole data contents of vestibular reactions. The practicability of the method is documented by the author's own research work in this field. PMID:320167

  17. Normal pressure hydrocephalus after gamma knife radiosurgery for vestibular schwannoma

    Directory of Open Access Journals (Sweden)

    Mohammed T

    2010-01-01

    Full Text Available Vestibular schwannomas are not uncommon, and gamma knife radiosurgery is one of the treatment options for symptomatic tumors. Hydrocephalus is a complication of gamma knife treatment of vestibular schwannoma, though the mechanism of the development of hydrocephalus remains controversial. We present an unusual case of normal pressure hydrocephalus (NPH after gamma knife radiosurgery of a vestibular schwannoma in which the timeline of events strongly suggests that gamma knife played a contributory role in the development of the hydrocephalus. This is probably the first case of NPH post radiosurgery with normal cerebrospinal fluid protein. Communicating hydrocephalus should be treated with placement of shunt while non-communicating hydrocephalus can be treated with third ventriculostomy. Frequent monitoring and early intervention post radiosurgery is highly recommended to prevent irreversible cerebral damage.

  18. Rapid adaptation of multisensory integration in vestibular pathways

    Science.gov (United States)

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

    2015-01-01

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

  19. Rapid adaptation of multisensory integration in vestibular pathways.

    Science.gov (United States)

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

    2015-01-01

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

  20. Visual gravitational motion and the vestibular system in humans

    Directory of Open Access Journals (Sweden)

    FrancescoLacquaniti

    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.

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

    Directory of Open Access Journals (Sweden)

    Nicholas J. Cutfield

    2014-01-01

    Full Text Available 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 function in BVL patients.

  2. Sensory substitution in bilateral vestibular a-reflexic patients

    Science.gov (United States)

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

    2015-01-01

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

  3. Plasticity during vestibular compensation: the role of saccades

    Directory of Open Access Journals (Sweden)

    IanSCurthoys

    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.

  4. Vestibular Rehabilitation In Unilateral Peripheral Vestibulopathy: A Preliminary Report

    Directory of Open Access Journals (Sweden)

    Birgul DONMEZ

    2008-06-01

    Full Text Available Vestibular rehabilitation was indicated for patients with vestibulopathy. We evaluated the effect of home supervised vestibular rehabilitation and visual feedback posturography training fourteen patients in a controlled study. Patients were assessed before and after rehabilitation by the Dynamic gait index, the Dizziness handicap inventory, the Berg balance scale and by static posturography. Supervised home program group significantly improved in Berg balance scale, dizziness handicap inventory and movement velocity (p<0.05. Visual feedback posturography group improved significantly in dizziness handicap inventory, reaction time, movement velocity and maximum excursion (p<0.05. But there were not significant differences between home supervised and visual feedback posturography group after treatment.

  5. Superior Semicircular Canal Dehiscence Syndrome without Vestibular Symptoms.

    Science.gov (United States)

    Teixeira, Emidio Oliveira; Fonseca, Marconi Teixeira

    2014-04-01

    Introduction?Superior semicircular canal dehiscence syndrome is mainly characterized by vestibular symptoms induced by intense sound stimuli or pressure changes, which occur because of dehiscence of the bony layer covering the superior semicircular canal. Case Report?Here, we report a case of the syndrome with pulsatile tinnitus and ear fullness, in the absence of vestibular symptoms. Discussion?Signs and symptoms of the syndrome are rarely obvious, leading to the requirement for a minimum workup to rule out or make diagnosis more probable and thus avoid misconduct. PMID:25992092

  6. Superior Semicircular Canal Dehiscence Syndrome without Vestibular Symptoms

    Scientific Electronic Library Online (English)

    Emidio Oliveira, Teixeira; Marconi Teixeira, Fonseca.

    2014-04-01

    Full Text Available Introduction Superior semicircular canal dehiscence syndrome is mainly characterized by vestibular symptoms induced by intense sound stimuli or pressure changes, which occur because of dehiscence of the bony layer covering the superior semicircular canal. Case Report Here, we report a case of t [...] he syndrome with pulsatile tinnitus and ear fullness, in the absence of vestibular symptoms. Discussion Signs and symptoms of the syndrome are rarely obvious, leading to the requirement for a minimum workup to rule out or make diagnosis more probable and thus avoid misconduct.

  7. Neurohumoral reactions to long-term vestibular stimulation in man.

    Science.gov (United States)

    Nichiporuk, I A; Rapotkov, A N; Orlov, O I; Grigoriev, A I

    1993-02-01

    The main purposes of present work were: 1) to examine neurohumoral reactions to long-term vestibular stimulation provocative for MS symptoms in man; 2) to compare the peculiarities of neuroendocrine reactions to short-term and to long-term vestibular stimulation; 3) to analyze the received results from the position of neuroendocrine adaptive reactions biological conformity to natural laws, and its physiological importance for human organisms; 4) to make some prognostic points of neurohumoral reaction changes on health and capacity for work in subjects influenced by professional conditions, provocative for MS manifestation development. PMID:11538529

  8. Auditory and vestibular dysfunctions in systemic sclerosis: literature review / Alterações auditivas e vestibulares na Esclerose Sistêmica: revisão de literatura

    Scientific Electronic Library Online (English)

    Maysa Bastos, Rabelo; Corona, Ana Paula.

    2014-10-01

    Full Text Available Objetivo: Descrever a prevalência das alterações auditivas e vestibulares em indivíduos com Esclerose Sistêmica (ES) e as hipóteses elencadas para explicar essas alterações. Estratégia de pesquisa: Revisão sistemática, sem meta-análise, a partir das bases de dados PubMed, LILACS, Isi Web of Science, [...] SciELO e SCOPUS, utilizando a combinação das palavras-chave "systemic sclerosis AND balance OR vestibular" e "systemic sclerosis AND hearing OR auditory". Critérios de seleção: Foram incluídos artigos publicados em Português, Espanhol ou Inglês até dezembro de 2011 e excluídos os artigos de revisão de literatura, cartas e editoriais. Foram localizados 254 artigos e selecionados dez. Análise dos dados: Foi realizada a descrição do delineamento dos estudos e elencadas as características e frequência das alterações auditivas e vestibulares. Após, investigaram-se as hipóteses formuladas pelos autores para explicar o comprometimento auditivo e vestibular na ES. Resultados: A perda auditiva foi o achado mais comum, com prevalência de 20 a 77%, sendo o tipo sensorioneural bilateral o mais frequente. Hipotetiza-se que o prejuízo auditivo na ES é decorrente de alterações vasculares na cóclea. A prevalência das alterações vestibulares variou de 11 a 63%, e os achados mais frequentes foram alterações na prova calórica, nistagmo de posicionamento, resposta oculocefálica anormal, alterações nos testes clínicos de integração sensorial e vertigem postural paroxística benigna. Conclusão: Elevada prevalência de alterações auditivas e vestibulares em pacientes com ES. A condução de novas investigações pode colaborar na identificação precoce dessas alterações, fornecer subsídios para os profissionais que atuam junto a esses pacientes e contribuir para a melhoria da qualidade de vida desses indivíduos. Abstract in english Purpose: To describe the prevalence of auditory and vestibular dysfunction in individuals with systemic sclerosis (SS) and the hypotheses to explain these changes. Research strategy: We performed a systematic review without meta-analysis from PubMed, LILACS, Web of Science, SciELO and SCOPUS datab [...] ases, using a combination of keywords "systemic sclerosis AND balance OR vestibular" and "systemic sclerosis AND hearing OR auditory." Selection criteria: We included articles published in Portuguese, Spanish, or English until December 2011 and reviews, letters, and editorials were excluded. We found 254 articles, out of which 10 were selected. Data analysis: The study design was described, and the characteristics and frequency of the auditory and vestibular dysfunctions in these individuals were listed. Afterwards, we investigated the hypothesis built by the authors to explain the auditory and vestibular dysfunctions in SS. Results: Hearing loss was the most common finding, with prevalence ranging from 20 to 77%, being bilateral sensorineural the most frequent type. It is hypothesized that the hearing impairment in SS is due to vascular changes in the cochlea. The prevalence of vestibular disorders ranged from 11 to 63%, and the most frequent findings were changes in caloric testing, positional nystagmus, impaired oculocephalic response, changes in clinical tests of sensory interaction, and benign paroxysmal positional vertigo. Conclusion: High prevalence of auditory and vestibular dysfunctions in patients with SS was observed. Conducting further research can assist in early identification of these abnormalities, provide resources for professionals who work with these patients, and contribute to improving the quality of life of these individuals.

  9. Factors relating to depressive symptoms among elderly people with chronic vestibular dysfunction / Fatores relacionados aos sintomas depressivos de idosos com disfunção vestibular crônica

    Scientific Electronic Library Online (English)

    Juliana Maria, Gazzola; Mayra Cristina, Aratani; Flávia, Doná; Camila, Macedo; Márcia Maiumi, Fukujima; Maurício Malavasi, Ganança; Fernando Freitas, Ganança.

    2009-06-01

    Full Text Available OBJETIVO: Identificar os fatores relacionados aos sintomas depressivos de idosos com disfunção vestibular crônica. MÉTODO: Estudo transversal, em que 120 idosos com disfunção vestibular crônica submeteram-se ao questionário Geriatric Depression Scale. Realizou-se análise de regressão linear multivar [...] iada (p Abstract in english OBJECTIVE: To identify factors relating to depressive symptoms among elderly people with chronic vestibular dysfunction. METHOD: This was a cross-sectional study in which 120 elderly people with chronic vestibular dysfunction answered the Geriatric Depression Scale questionnaire. Multivariate linear [...] regression analysis was performed (p

  10. Potenciais evocados auditivos em indivíduos com síndrome vestibular periférica / Auditory evoked potentials in peripheral vestibular disorder individuals

    Scientific Electronic Library Online (English)

    Carla Gentile, Matas; Sara Manami, Silva; Débora Dong Mei, Wen; Cristiane da Silva, Nunes; Seisse Gabriela Gandolfi, Sanches.

    2011-09-01

    Full Text Available INTRODUÇÃO: Os sistemas auditivo e vestibular estão localizados no mesmo receptor periférico, porém adentram ao SNC e percorrem caminhos distintos, estabelecendo uma série de conexões e abrangendo uma vasta região do encéfalo. Mesmo percorrendo caminhos diferentes, algumas alterações podem compromet [...] er ambos os sistemas. Testes como os Potenciais Evocados Auditivos podem auxiliar no diagnóstico com alterações vestibulares. OBJETIVO: Caracterizar os resultados dos Potenciais Evocados Auditivos de indivíduos com queixa de tontura ou vertigem com Síndromes Vestibulares Periféricas e com indivíduos normais, com a mesma queixa. MÉTODO: Foram realizados os Potenciais Evocados Auditivos de curta, média e longa latência, sendo um estudo prospectivo transversal. CONCLUSÃO: Indivíduos com queixa de tontura ou vertigem podem apresentar alterações no PEATE, PEAML e P300. Abstract in english INTRODUCTION: The auditory and vestibular systems are located in the same peripheral receptor, however they enter the CNS and go through different ways, thus creating a number of connections and reaching a wide area of the encephalon. Despite going through different ways, some changes can impair bot [...] h systems. Such tests as Auditory Evoked Potentials can help find a diagnosis when vestibular alterations are seen. OBJECTIVE: describe the Auditory Evoked Potential results in individuals complaining about dizziness or vertigo with Peripheral Vestibular Disorders and in normal individuals having the same complaint. METHODS: Short, middle and long latency Auditory Evoked Potentials were performed as a transversal prospective study. CONCLUSION: individuals complaining about dizziness or vertigo can show some changes in BAEP (Brainstem Auditory Evoked Potential), MLAEP (Medium Latency Auditory Evoked Potential) and P300.

  11. Doença vestibular periférica decorrente de osteoartropatia temporoioídea em um eqüino Peripheral vestibular disease associated with temporohyoid osteoarthropathy in a horse

    Directory of Open Access Journals (Sweden)

    Alexandre Secorun Borges

    2003-06-01

    Full Text Available Um eqüino com 22 anos de idade apresentou síndrome vestibular periférica associada à paralisia de nervo facial esquerdo devido à osteoartropatia temporoioídea. O exame endoscópico das bolsas guturais mostrou alteração de contorno da bula timpânica esquerda e aumento de volume da extremidade proximal do osso estiloióide do mesmo lado.A 22-year-old gelding showed vestibular syndrome associated with left facial nerve paralysis due to temporohyoid osteoarthropathy and the diagnostic was confirmed by guttural pouch endoscopic examination. The exam revealed abnormal contour of the left tympanic bulla and an enlargement of the proximal part of the left stylohyoid bone.

  12. Posturografia com estímulos de realidade virtual nas diferentes disfunções vestibulares / Posturography with virtual reality stimuli in different vestibular dysfunctions

    Scientific Electronic Library Online (English)

    Marcelo Eiji Inoue, Yamamoto; Cristina Freitas, Ganança.

    2012-03-01

    Full Text Available OBJETIVO: Avaliar o equilíbrio corporal e quantificar possíveis alterações na posturografia estática do Balance Rehabilitation Unit (BRU TM) em pacientes com disfunção vestibular. MÉTODOS: Estudo retrospectivo, com prontuários de 100 pacientes com topodiagnóstico de disfunção vestibular periférica o [...] u central e 100 indivíduos hígidos compondo o Grupo Controle, de ambos os gêneros, entre 7 a 86 anos. Para a posturografia foi utilizado o equipamento Balance Rehabilitation Unit (BRU TM), da Medicaa®. Foram analisados os parâmetros limite de estabilidade, área de elipse e velocidade de oscilação em dez condições sensoriais. RESULTADOS: A média dos valores do limite de estabilidade, da área de elipse e da velocidade de oscilação do Grupo Experimental foi significativa em relação ao Grupo Controle em todas as condições. A média dos parâmetros do gênero feminino do Grupo Experimental foi significativa em relação ao do Grupo Controle em todas as condições avaliadas. Os pacientes com disfunção vestibular central obtiveram maiores valores que os pacientes com disfunção vestibular periférica nas variáveis área de elipse e velocidade de oscilação, porém menor valor da área do limite de estabilidade. CONCLUSÃO: A posturografia com estímulos de realidade virtual foi um método de avaliação eficaz para detectar alterações relacionadas às variáveis limite de estabilidade, área de elipse e velocidade de oscilação, uma vez que o Grupo Controle obteve melhor desempenho, tanto entre os grupos quanto entre os gêneros. Entre as disfunções vestibulares, os indivíduos com acometimento periférico obtiveram melhor desempenho do que os indivíduos com disfunção vestibular central em todas as variáveis analisadas na posturografia. Abstract in english PURPOSE: To assess body balance and to quantify possible alterations over the static posturography of the Balance Rehabilitation Unit (BRU TM) in patients with vestibular dysfunction. METHODS: Retrospective study, with files of 100 patients with topographic diagnosis of peripheral or central vestibu [...] lar dysfunction and 100 healthy individuals that composed the control group, of both genders, with ages varying between 7 and 86 years. For the posturography, the Balance Rehabilitation Unit (BRU TM), of Medicaa® was used. The following parameters were analyzed: stability limits, elliptical area, and speed of oscillation in ten sensory conditions. RESULTS: Mean values ??of the stability limit, the elliptical area and the speed of oscillation in the experimental group was significant when compared to the control group in all conditions. The mean parameters of the female experimental group were significant when compared to the control group in all conditions. Patients with central vestibular dysfunction obtained higher values than patients with peripheral vestibular dysfunction in the variables elliptical area and speed of oscillation, however with lower value of the area of the stability limit. CONCLUSION: Posturography with virtual reality stimuli was an effective assessment method for detecting alterations related to the variables stability limits, elliptical area, and speed of oscillation, since the control group performed better, both between groups and between genders. Among the vestibular dysfunctions, individuals with peripheral condition performed better than those with central vestibular dysfunction in all the variables analyzed on posturography.

  13. Configuração das pregas vestibulares em laringes de pacientes com nódulo vocal Vestibular folds configuration in vocal nodule

    Directory of Open Access Journals (Sweden)

    Juliane Tuma

    2005-10-01

    Full Text Available O nódulo vocal está entre as laringopatias mais comuns que resultam em alterações na função vocal. O mecanismo da produção da fala é complexo e exige interação de diversos sistemas do organismo humano. A importância das pregas vocais na fisiologia e na formação da fonte sonora glótica é evidente; contudo, quanto à participação das pregas vestibulares neste processo, ainda não existe consenso entre os estudiosos da área. OBJETIVO: Verificar se existe diferença na conformação das pregas vestibulares entre dois grupos de indivíduos do sexo feminino, sendo um composto por pacientes com diagnóstico de nódulo vocal e outro por pacientes sem alteração da voz e sem lesão em pregas vocais. FORMA DE ESTUDO: clínico com coorte transversal MATERIAL E MÉTODO: Foram analisadas 96 imagens de laringes, de indivíduos do sexo feminino, sendo 48 sem queixa vocal e 48 com diagnóstico de nódulo vocal. Foram medidos os ângulos formados nas pregas vestibulares durante a fonação, dos lados direito e esquerdo, bem como feita classificação das mesmas quanto à forma (côncava, linear ou convexa. RESULTADOS: Das 96 pregas vestibulares analisadas em cada grupo, a forma côncava foi predominante, seguida da linear e da convexa. No grupo controle, apenas uma das pregas estudadas tinha a conformação convexa, 27 conformação linear e 68 eram côncavas, enquanto no grupo nódulo vocal os resultados foram 8 convexas, 15 lineares e 73 côncavas. Estas diferenças não apresentaram significância, bem como as diferenças nos ângulos, cujas médias foram bastante semelhantes. CONCLUSÃO: As pregas vestibulares no sexo feminino se comportam da mesma maneira tanto nas pacientes com nódulo vocal quanto nas mulheres sem queixa vocal.Vocal nodules are among the most common laryngopathies that cause vocal functional disorders. The voice production mechanism is complex and demand interaction of different systems of the human body. The physiological role of the vocal folds as the glottic sound source is evident, however, there is no consensus regarding the vestibular folds' participation/influence in phonation. AIM: To verify if there is difference in the bidimensional configuration of the vestibular folds between two distinct groups of women, one with the diagnosis of vocal nodules and the other without vocal complaints and vocal fold lesions. STUDY DESIGN: clinical with transversal cohort. MATERIAL AND METHOD: Ninety-six laryngeal images were evaluated, 48 from individuals without vocal complaints and 48 from patients with the diagnosis of vocal nodules. Angles were obtained and bilaterally measured in single frames of the vestibular folds during sustained phonation and those structures were morphologically classified as concave, linear or convex. RESULTS: Among the 96 vestibular folds evaluated in each group, there was predominance of the concave form, followed by the linear and the convex ones. In the control group, there was a single convex vestibular fold, 27 were linear and 68 were concave folds. In the group of vocal nodules, 8 were convex, 15 were linear and 73 were concave folds. However, the differences among groups were not statistically significant as well as those among the angles, whose average measures were proven quite similar. CONCLUSION: In the female gender, the vestibular folds presented similar behavior regarding the morphology in both patients with vocal nodules and women without vocal complaints.

  14. Configuração das pregas vestibulares em laringes de pacientes com nódulo vocal / Vestibular folds configuration in vocal nodule

    Scientific Electronic Library Online (English)

    Juliane, Tuma; Osíris Oliveira, Camponês do Brasil; Paulo Augusto de Lima, Pontes; Reinaldo Kasuo, Yasaki.

    2005-10-01

    Full Text Available O nódulo vocal está entre as laringopatias mais comuns que resultam em alterações na função vocal. O mecanismo da produção da fala é complexo e exige interação de diversos sistemas do organismo humano. A importância das pregas vocais na fisiologia e na formação da fonte sonora glótica é evidente; co [...] ntudo, quanto à participação das pregas vestibulares neste processo, ainda não existe consenso entre os estudiosos da área. OBJETIVO: Verificar se existe diferença na conformação das pregas vestibulares entre dois grupos de indivíduos do sexo feminino, sendo um composto por pacientes com diagnóstico de nódulo vocal e outro por pacientes sem alteração da voz e sem lesão em pregas vocais. FORMA DE ESTUDO: clínico com coorte transversal MATERIAL E MÉTODO: Foram analisadas 96 imagens de laringes, de indivíduos do sexo feminino, sendo 48 sem queixa vocal e 48 com diagnóstico de nódulo vocal. Foram medidos os ângulos formados nas pregas vestibulares durante a fonação, dos lados direito e esquerdo, bem como feita classificação das mesmas quanto à forma (côncava, linear ou convexa). RESULTADOS: Das 96 pregas vestibulares analisadas em cada grupo, a forma côncava foi predominante, seguida da linear e da convexa. No grupo controle, apenas uma das pregas estudadas tinha a conformação convexa, 27 conformação linear e 68 eram côncavas, enquanto no grupo nódulo vocal os resultados foram 8 convexas, 15 lineares e 73 côncavas. Estas diferenças não apresentaram significância, bem como as diferenças nos ângulos, cujas médias foram bastante semelhantes. CONCLUSÃO: As pregas vestibulares no sexo feminino se comportam da mesma maneira tanto nas pacientes com nódulo vocal quanto nas mulheres sem queixa vocal. Abstract in english Vocal nodules are among the most common laryngopathies that cause vocal functional disorders. The voice production mechanism is complex and demand interaction of different systems of the human body. The physiological role of the vocal folds as the glottic sound source is evident, however, there is n [...] o consensus regarding the vestibular folds' participation/influence in phonation. AIM: To verify if there is difference in the bidimensional configuration of the vestibular folds between two distinct groups of women, one with the diagnosis of vocal nodules and the other without vocal complaints and vocal fold lesions. STUDY DESIGN: clinical with transversal cohort. MATERIAL AND METHOD: Ninety-six laryngeal images were evaluated, 48 from individuals without vocal complaints and 48 from patients with the diagnosis of vocal nodules. Angles were obtained and bilaterally measured in single frames of the vestibular folds during sustained phonation and those structures were morphologically classified as concave, linear or convex. RESULTS: Among the 96 vestibular folds evaluated in each group, there was predominance of the concave form, followed by the linear and the convex ones. In the control group, there was a single convex vestibular fold, 27 were linear and 68 were concave folds. In the group of vocal nodules, 8 were convex, 15 were linear and 73 were concave folds. However, the differences among groups were not statistically significant as well as those among the angles, whose average measures were proven quite similar. CONCLUSION: In the female gender, the vestibular folds presented similar behavior regarding the morphology in both patients with vocal nodules and women without vocal complaints.

  15. Congenital nasal piriform aperture stenosis with vestibular abnormality

    Energy Technology Data Exchange (ETDEWEB)

    Rajaram, Smitha; Raghavan, Ashok [Sheffield Children' s Hospital, Department of Paediatric Radiology, Sheffield (United Kingdom); Bateman, Neil [Sheffield Children' s Hospital, ENT Department, Sheffield (United Kingdom)

    2008-10-15

    We present a neonate with congenital nasal piriform aperture stenosis associated with an abnormal vestibular aperture. Radiological evaluation with CT is essential to confirm the diagnosis and delineate the anatomy for surgical planning. Extension of the scan field of view to include the petrous temporal bone is essential to identify associated abnormalities of the vestibule. (orig.)

  16. Determining Benchmarks in Hearing Preservation Surgery for Vestibular Schwannoma

    OpenAIRE

    Gluth, Michael B.; Day, John D.; Dornhoffer, John L.

    2012-01-01

    Objectives?The objectives of this study were to determine minimal benchmarks of success in vestibular schwannoma hearing preservation surgery, wherein the likelihood of having preserved hearing in a single patient is at least as likely as having created a poor facial nerve outcome for a single patient.

  17. Fractionated stereotactic radiotherapy of vestibular schwannomas accelerates hearing loss

    DEFF Research Database (Denmark)

    Rasmussen, Rune; Claesson, Magnus

    2012-01-01

    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.

  18. 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.

  19. Vertical torque responses to vestibular stimulation in standing humans.

    Science.gov (United States)

    Reynolds, Raymond F

    2011-08-15

    The effects of electrical vestibular stimulation upon movement and perception suggest two evoked sensations: head roll and inter-aural linear acceleration. The head roll vector causes walking subjects to turn in a direction dependent on head pitch, requiring generation of torque around a vertical axis. Here the effect of vestibular stimulation upon vertical torque (T(z)) was investigated during quiet stance. With the head tilted forward, square-wave stimuli applied to the mastoid processes evoked a polarity-specific T(z) response accompanied by trunk yaw. Stochastic vestibular stimulation (SVS) was used to investigate the effect of head pitch with greater precision; the SVS–T(z) cross-correlation displayed a modulation pattern consistent with the head roll vector and this was also reflected by changes in coherence at 2–3 Hz. However, a separate response at 7–8 Hz was unaffected by head pitch. Head translation (rather than rotation) had no effect upon this high frequency response either, suggesting it is not caused by a sense of body rotation induced by an inter-aural acceleration vector offset from the body. Instead, high coherence between medio-lateral shear force and T(z) at the same frequency range suggests it is caused by mechanical coupling to evoked medio-lateral sway. Consistent with this explanation, the 7–8 Hz response was attenuated by 90 deg head roll or yaw, both of which uncouple the inter-aural axis from the medio-lateral sway axis. These results demonstrate two vertical torque responses to electrical vestibular stimulation in standing subjects. The high frequency response can be attributed to mechanical coupling to evoked medio-lateral sway. The low frequency response is consistent with a reaction to a sensation of head roll, and provides a novel method for investigating proprioceptive-vestibular interactions during stance. PMID:21690188

  20. Artificial balance: restoration of the vestibulo-ocular reflex in humans with a prototype vestibular neuroprosthesis

    Directory of Open Access Journals (Sweden)

    AngelicaPerez Fornos

    2014-04-01

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

  1. Developmental and Age-related Changes in Morphometry and Cellular Density of the Vestibular Ganglion in the Chick

    Directory of Open Access Journals (Sweden)

    A.G. Pillay

    1999-01-01

    Full Text Available Vestibular ganglia at different stages of development in the chick and that of the adult were fixed in formal-saline. Serial sections were taken and stained by cresyl fast violet to analyse the results. Cells were categorised and counted. Ganglionic volume is the greatest on E18 during the whole ontogeny even though its rostrocaudal length is the greatest in the adult. This is quite different from that observed in other ganglia studied where the ganglionic volume is the greatest in the adult situation. The increased size of the ganglion on E18 might be related to the increased size of the cells, increased size of the neuropil (network of neuronal processes and neuroglia and to the effects of tissue reactions resulting from the toxic substances of the dead cells. The loss of cells in the adult in comparison to that observed on the day of hatching might indicate a functional reduction as a result of ageing process. The fluctuation in the number of cells during development might be considered as a normal process for the purpose of re-arrangement for better organisation in order to perform an efficient function. The cell-loss has essentially ended around E15 by the time the ganglion begins to show its greatest expansion so as to reach its maximum size on E18. The appearance of a few light cells in the vestibular ganglion on E6 might indirectly indicate the beginning of an early establishment of a functional connection. This might possibly mean that an early development of functional organisation of the vestibular ganglion is an important factor for the proper development of other organs and systems during embryonic development. The appearance of an increased number of tiny cells in the adult ganglion is peculiar from that observed in other ganglia studied; possibly these tiny cells, by their growth, maturation and establishment of functional connections, replace those inactive (or dead cells, during ageing process. Possibly, continuation of an efficient vestibular function is important for the normal behaviour of the animal.

  2. Dizziness handicap inventory - em um grupo de pacientes submetidos a reabilitação vestibular personalizada / Dizziness handicap inventory- in a group of patients undergoing customized vestibular rehabilitation

    Scientific Electronic Library Online (English)

    Ana Carla Leite, Romero; Matheus Siqueira Yoshihiro, Hayashi; Marcos Seizo, Kishi; Ana Claúdia Vieira, Cardoso; Ana Cláudia Figueiredo, Frizzo.

    2015-06-01

    Full Text Available OBJETIVO: investigar o impacto da Reabilitação Vestibular personalizada e comparar os aspectos físicos, emocionais e funcionais pré e pós a aplicação do Dizziness Handicap Inventory. MÉTODOS: participaram 10 pacientes, com sintomas decorrentes de distúrbios do sistema vestibular e hipótese diagnóst [...] ica de disfunção vestibular crônica. Estes foram avaliados quanto aos aspectos físicos, emocionais e funcionais por meio do Dizziness Handicap Inventory pré e pós reabilitação vestibular personalizada. RESULTADOS: no Dizziness Handicap Inventory pré foi verificado que o aspecto físico foi o mais pontuado, seguido pelo emocional e funcional. A reabilitação vestibular foi eficaz, uma vez que houve diminuição nas queixas de qualidade de vida, e melhores resultados em todos os aspectos avaliados no Dizziness Handicap Inventory pós, apenas um paciente obteve melhora somente dos aspectos emocionais e funcionais, além de piora dos aspectos físicos. CONCLUSÃO: o Dizziness Handicap Inventory brasileiro aplicado pré e pós reabilitação vestibular personalizada mostrou-se como um teste eficaz para acompanhar pacientes submetidos a reabilitação vestibular, capaz de mostrar a melhora significante nos sintomas da vertigem crônica, além do impacto negativo na qualidade de vida dos pacientes deste estudo. Abstract in english PURPOSE: to describe the results obtained from the application of the DHI, pre and post customized vestibular rehabilitation in order to verify the efficiency of rehabilitation in this population. METHODS: the sample consisted of 10 patients with symptoms caused by disorders of the vestibular syste [...] m and diagnosis of chronic vestibular dysfunction. These patients were evaluated for physical, emotional and functional aspects using the Dizziness Handicap Inventory pre and post customized vestibular rehabilitation. RESULTS: on the pre Dizziness Handicap Inventory it was verified that the physical aspects was the most highly scored, followed by the emotional and functional. Vestibular rehabilitation was effective, since there was a decrease in complaints concerning quality of life and better results in all the aspects evaluated in Dizziness Handicap Inventory post rehabilitation, only one patient reported improvement in emotional and functional, and worsening of the physical aspects. CONCLUSION: The Dizziness Handicap Inventory, Brazilian version, applied pre and post customized vestibular rehabilitation proved to be an efficient test to monitor patients undergoing vestibular rehabilitation, this device was able to show significant improvement in symptoms of chronic vertigo, and improved the quality of life of the patients in this study.

  3. THE DINAMICS OF IMPULSE ACTIVITY OF THE INFERIOR VESTIBULAR NUCLEUS UNDER CONDITIONS OF VIBRATION IN LABYRINTHECTOMIED RATS

    Directory of Open Access Journals (Sweden)

    S.G.Sargsyan

    2010-09-01

    Full Text Available The computer analyzes of the inferior vestibular nuclei was performed in norm and after unilateral labyrinthactomy of right site. On 2-d day after oparation, animals were vibrated with diferent period (5, 10 and 15 days. Benchmark analysis of the features of background pulse activity of both nuclei neurons showed initial asymmetry of the impulse average frequency and factor of variation of interspike intervals. It was showed, that after 5 days vibration average frequency of Roller’s both nuclei impulses were they nearly justified in labyrinthactomied labirintactomied rats. After 15 days vibration impulse average frequency was higher on damaged site, than on unstrucked site. The particularities and functional importance our results are discussed.

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

    Directory of Open Access Journals (Sweden)

    ChristopheLopez

    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.

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

    DEFF Research Database (Denmark)

    Friberg, L; Olsen, T S

    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. On the rCBF display this area was located in the superior temporal region posterior to the auditory area, probably in the superior temporal gyrus. It is suggested that this area represents the primary projection area of the vestibular nerve and that it is the activation of this area during caloric stimulation that gives rise to the associated conscious vestibular sensation of vertigo.

  6. Schwanoma vestibular como causa de surdez súbita / Vestibular schwannoma presenting as sudden hearing loss

    Scientific Electronic Library Online (English)

    Eduardo M., Kosugi; Rodrigo P., Tangerina; Gabriel C., Dib; Hugo V. L., Ramos; Norma O., Penido.

    2004-12-01

    Full Text Available A Surdez Súbita (SS) é um sintoma causado por mais de 60 doenças diferentes, dentre elas, o Schwanoma Vestibular (SV). Shaia & Sheehy (1976) apresentaram uma incidência de 1% de SV em 1220 casos de SS. Não há características específicas para o diagnóstico do SV, sendo a ressonância magnética (RM) o [...] exame de escolha. OBJETIVO: Verificar a real incidência de SV em casuísticas de SS com a realização de RM. FORMA DE ESTUDO: Coorte transversal. MATERIAL E MÉTODO: Estudo prospectivo com a realização de RM com contraste de gadolínio em todos os pacientes com SS do serviço de urgência em Otorrinolaringologia do Hospital São Paulo no período de abril de 2001 a maio de 2003. RESULTADOS: Foram realizados exames de RM em 49 pacientes que apresentaram SS, sendo diagnosticados 3 (6,1%) casos de SV. CONCLUSÃO: A incidência real de SV em casuísticas de SS pode ser maior do que o classicamente descrito na literatura, devido ao subdiagnóstico pela não-utilização da RM de rotina nestes casos. Abstract in english The sudden Hearing Loss (SHL) is a symptom caused by more than 60 different diseases, including Vestibular Schwannoma (VS). Shaia & Sheehy (1976) presented a study with 1,220 cases of SHL reporting 1% incidence of VS. There is no specific characteristic for the diagnosis of VS and Magnetic Resonance [...] Imaging (MRI) is the gold standard exam to diagnose such disease. AIM: To determine the real incidence of VS presenting as SHL performing MRI in all patients with SHL. STUDY DESIGN: Transversal cohort. MATERIL AND METHOD: Prospective study in which MRI with gadolinium was performed in all patients with SHL in the Emergency Service of Sao Paulo Hospital from April 2001 through May 2003. RESULTS: MRI was performed in 49 patients with symptoms of SHL, with three cases (6.1%) of VS found. CONCLUSION: The real incidence of VS presenting as SHL may be greater than that mentioned in conventional reports probably because MRI had not been performed in all patients with SHL.

  7. Galvanic vestibular stimulator for fMRI studies

    Scientific Electronic Library Online (English)

    Hellen Mathei, Della-Justina; Tiago, Manczak; Anderson Marcelo, Winkler; Dráulio Barros de, Araújo; Mauren Abreu de, Souza; Edson, Amaro Junior; Humberto Remigio, Gamba.

    2014-03-01

    Full Text Available INTRODUCTION: Areas of the brain that are associated with the vestibular system can be activated using galvanic vestibular stimulation. These areas can be studied through a combination of galvanic vestibular stimulation with functional magnetic resonance imaging (fMRI). In order to provide an approp [...] riate sequence of galvanic stimulation synchronous with the MRI pulse sequence, a specific electronic device that was built and assessed is presented. METHODS: The electronic project of the GVS is divided in analog and digital circuits. The analog circuits are mounted in an aluminum case, supplied by sealed batteries, and goes inside the MRI room near to the feet of the subject. The digital circuits are placed in the MRI control room. Those circuits communicate through each other by an optical fiber. Tests to verify the GVS-MRI compatibility were conducted. Silicone (in-house) and Ag/AgCl (commercial) electrodes were evaluated for maximum balance and minimal pain sensations. fMRI experiments were conducted in eight human volunteers. RESULTS: GVS-MRI compatibility experiments demonstrate that the GVS did not interfere with the MRI scanner functionality and vice versa. The circular silicone electrode was considered the most suitable to apply the galvanic vestibular stimulation. The 1 Hz stimulation sinusoid frequency produced the biggest balance and the less pain sensations when compared to 2 Hz. The GVS was capable of eliciting activation in the precentral and postcentral gyri, in the central sulcus, in the supplementary motor area, in the middle and inferior frontal gyri, in the inferior parietal lobule, in the insula, in the superior temporal gyrus, in the middle cingulate cortex, and in the cerebellum. CONCLUSION: This study shows the development and description of a neurovestibular stimulator that can be safely used inside the MRI scanner room without interfering on its operation and vice versa. The developed GVS could successfully activate the major areas involved with multimodal functions of the vestibular system, demonstrating its validity as a stimulator for neurovestibular research. To the best of our knowledge, this is the first work that shows the development and the construction of a galvanic vestibular stimulator that could be safely used inside the MRI room.

  8. Vestibular impairment and adaptive postural imbalance in parkinsonian patients with lateral trunk flexion.

    Science.gov (United States)

    Vitale, Carmine; Marcelli, Vincenzo; Furia, Teresa; Santangelo, Gabriella; Cozzolino, Autilia; Longo, Katia; Allocca, Roberto; Amboni, Marianna; Marciano, Elio; Barone, Paolo

    2011-07-01

    Lateral trunk flexion is a very common clinical observation in patients affected by Parkinson's disease. Postural control is known to depend on vestibular, visual, and somatosensory information. The aim of this study was to investigate whether impairment of vestibular function can account for the postural alterations observed in parkinsonian patients with lateral trunk flexion. We evaluated vestibular function in 11 parkinsonian patients with lateral trunk flexion and in 11 age-, sex-, and disease duration-matched patients without lateral trunk flexion. The following vestibular tests were performed: infrared videonystagmography including fast and slow ocular movements, spontaneous-positional and evoked nystagmus search with and without visual fixation, fast positioning maneuvers, the bithermal caloric test, and the vibration test. A peripheral, unilateral vestibular hypofunction was identified in all patients with lateral trunk flexion. The vestibular hypofunction was ipsilateral to the leaning side and contralateral to the most affected parkinsonian side in all patients. In the control group, 7 subjects had no vestibular signs; 4 subjects had unilateral vestibular hypofunction without clinically evident lateral trunk flexion. Two of the latter patients subsequently developed lateral trunk flexion ipsilateral to the vestibular deficit and contralateral to the side most affected by Parkinson's disease. The processing of vestibular information was impaired in parkinsonian patients affected by lateral trunk flexion. The impairment was at least in part responsible for the patients' postural abnormality. We propose that the acronym PISA (Postural Imbalance Syndrome with vestibular Alterations) be used to describe the specific postural change observed in parkinsonian patients affected by a vestibular defect and lateral trunk flexion. PMID:21465552

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

    OpenAIRE

    ChristopheLopez

    2013-01-01

    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...

  10. Retrograde tracing of medial vestibular nuclei connections to the kidney in mice

    OpenAIRE

    Hao, Yan; Tian, Xue-bi; Liu, Cheng; Xiang, Hong-bing

    2014-01-01

    Vestibular nuclei have been identified as a uniform multifunctional structure in order to maintain physiological homeostasis, including the participation of renal sympathetic activity. In this study, the medial vestibular nuclei (MVe) of 10 adult male C57BL/6J strain mice were mapped retrograde using injections of pseudorabies virus (PRV)-614. The virus, injected into the kidney, was specifically transported to the medial vestibular nuclei (MVe). We used a fluorescence immunohistochemistry to...

  11. 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.

  12. Enhanced Vestibulo-ocular Reflex to Electrical Vestibular Stimulation in Meniere’s Disease

    OpenAIRE

    Aw, Swee T.; Aw, Grace E.; Todd, Michael J.; Halmagyi, G. Michael

    2012-01-01

    Meniere’s disease is characterized by sporadic episodes of vertigo, nystagmus, fluctuating sensorineural hearing loss, tinnitus and aural pressure. Since Meniere’s disease can affect different regions of the vestibular labyrinth, we investigated if electrical vestibular stimulation (EVS) which excites the entire vestibular labyrinth may be useful to reveal patchy endorgan pathology. We recorded three-dimensional electrically evoked vestibulo-ocular reflex (eVOR) to transient EVS using bil...

  13. 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.; Wood, S.; Bloomberg, J. J.; Mulavara, A. P.

    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.

  14. Perspectival Structure and Vestibular Processing : A Commentary on Bigna Lenggenhager & Christophe Lopez

    DEFF Research Database (Denmark)

    Alsmith, Adrian John Tetteh

    2015-01-01

    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 to selectively manipulate and measure vestibular processing and perspectival structure. The hope is that this serves to indicate how interdisciplinary research on vestibular processing might advance our understanding of the structural features of conscious experience.

  15. Effect of vision, proprioception, and the position of the vestibular organ on postural sway.

    OpenAIRE

    Ekvall-hansson, Eva; Beckman, Anders; Ha?kansson, Anders

    2010-01-01

    Abstract Conclusion: When measured together, it seems that vision and proprioception as well as position of the vestibular organ affect postural sway, vision the most. Mediolateral (ML) sway does not seem to be influenced by the position of the vestibular organ. Objective: To investigate how postural sway was affected by provocation of vision, by the position of the vestibular organ, and by provocation of proprioception, when measured together. Methods: Postural sway was measured by using a f...

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

    OpenAIRE

    Ekvall-hansson, Eva; Magnusson, Ma?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...

  17. Vestibular stimulation on a motion-simulator impacts on mood states

    OpenAIRE

    LottaWinter; JeanLaurens; HaraldEngler; M.AxelWollmer

    2012-01-01

    We are familiar with both pleasant and unpleasant psychotropic effects of movements associated with vestibular stimulation. However, there has been no attempt to scientifically explore the impact of different kinds of vestibular stimulation on mood states and biomarkers. A sample of 23 healthy volunteers were subjected to a random sequence of three different passive rotational (yaw, pitch, roll) and translational (heave, sway, surge) vestibular stimulation paradigms using a motion-simulato...

  18. Vestibular function in the temporal and parietal cortex: distinct velocity and inertial processing pathways.

    Science.gov (United States)

    Ventre-Dominey, Jocelyne

    2014-01-01

    A number of behavioral and neuroimaging studies have reported converging data in favor of a cortical network for vestibular function, distributed between the temporo-parietal cortex and the prefrontal cortex in the primate. In this review, we focus on the role of the cerebral cortex in visuo-vestibular integration including the motion sensitive temporo-occipital areas i.e., the middle superior temporal area (MST) and the parietal cortex. Indeed, these two neighboring cortical regions, though they both receive combined vestibular and visual information, have distinct implications in vestibular function. In sum, this review of the literature leads to the idea of two separate cortical vestibular sub-systems forming (1) a velocity pathway including MST and direct descending pathways on vestibular nuclei. As it receives well-defined visual and vestibular velocity signals, this pathway is likely involved in heading perception and rapid top-down regulation of eye/head coordination and (2) an inertial processing pathway involving the parietal cortex in connection with the subcortical vestibular nuclei complex responsible for velocity storage integration. This vestibular cortical pathway would be implicated in high-order multimodal integration and cognitive functions, including world space and self-referential processing. PMID:25071481

  19. Vestibular Function in the Temporal and Parietal Cortex: Distinct Velocity and Inertial Processing Pathways

    Directory of Open Access Journals (Sweden)

    Jocelyne Ventre-Dominey

    2014-07-01

    Full Text Available A number of behavioural and neuroimaging studies have reported converging data in favour of a cortical network for vestibular function, distributed between the temporo-parietal cortex and the prefrontal cortex in the primate. In this review, we focus on the role of the cerebral cortex in visuo-vestibular integration including the motion sensitive temporo-occipital areas i.e. the middle superior temporal area (MST and the parietal cortex. Indeed these two neighbouring cortical regions, though they both receive combined vestibular and visual information, have distinct implications in vestibular function. In sum, this review of the literature leads to the idea of two separate cortical vestibular sub-systems forming (1 a velocity pathway including MST and direct descending pathways on vestibular nuclei. As it receives well defined visual and vestibular velocity signals, this pathway is likely involved in heading perception and rapid top-down regulation of eye/head coordination and (2 an inertial processing pathway involving the parietal cortex in connection with the subcortical vestibular nuclei complex responsible for velocity storage integration. This vestibular cortical pathway would be implicated in high order multimodal integration and cognitive functions, including world space and self- referential processing.

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

    Science.gov (United States)

    Pfeiffer, Christian; Serino, Andrea; Blanke, Olaf

    2014-01-01

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

  1. Reabilitação vestibular em pacientes idosos portadores de vertigem posicional paroxística benigna Vestibular rehabilitation in elderly patients with benign paroxysmal positional vertigo

    Directory of Open Access Journals (Sweden)

    Carolina R. Resende

    2003-08-01

    Full Text Available A Vertigem Posicional Paroxística Benigna (VPPB é um distúrbio vestibular no qual os pacientes relatam breves momentos de vertigem e/ou leve instabilidade postural, ocasionados por uma mudança brusca na movimentação cefálica ou corporal. OBJETIVO: Verificar o benefício da reabilitação vestibular, realizada em grupo, em pacientes idosos portadores de VPPB. FORMA DE ESTUDO: Clínico prospectivo. MATERIAL E MÉTODO: Foram selecionados aleatoriamente 16 pacientes portadores de VPPB, todos medicados com extrato de Gingko-biloba (40mg de 12/12h durante 30 dias. Oito deles, que formaram o Grupo Experimental, além do medicamento, foram submetidos à reabilitação vestibular e oito compuseram o Grupo Controle que não realizaram nenhum tipo de exercício. Para avaliação do benefício aplicamos a Escala de Atividades de Vida Diária e Desordens Vestibulares proposta por Cohen e Kimball. Para a análise estatística utilizamos o teste t-student. CONCLUSÃO: Nossos resultados apontaram benefício promovido pela reabilitação vestibular em grupo no tratamento de idosos portadores de VPPB; a avaliação qualitativa mostrou-se instrumento importante para a avaliação de benefício para o tratamento proposto; e a reabilitação vestibular em grupo mostrou ser uma excelente estratégia terapêutica.The Benign Paroxysmal Positional Vertigo (BPPV is a vestibular disorder where the patients complain brief moments of vertigo and/or present postural instability, caused by a brusque change in the cephalic or body movement. AIM: The objective of the present study is certificate the benefit of the vestibular rehabilitation in elderly people with Benign Paroxysmal Positional Vertigo. STUDY DESIGN: Clinical prospective. MATERIAL AND METHOD: Sixteen patients with BPPV were thread with extract of Ginkgo-biloba (40mg of 12/12h during 30 days. Eight patients (the Experimental Group were submitted to vestibular rehabilitation and the other called Control Group, didn't perform any kind of exercises. In order to perform the evaluation of the benefit we used the Scale of Activity of Daily Life and Vestibular Disorders by Kohen and Kimball, and used the t-student test to statistical analysis. CONCLUSION: The vestibular rehabilitation in group showed benefit in the treatment in the Experimental Group; the Scale of Activity of Daily Life and Vestibular Disorders, was an important tool for the qualitative evaluation in our rehabilitation proposal and the vestibular rehabilitation in group showed as an excellent therapeutic strategy.

  2. Avaliação otoneurológica em crianças com queixa de dificuldades escolares: pesquisa da função vestibular / Otoneurologic evaluation in children with school difficulties: vestibular function investigation

    Scientific Electronic Library Online (English)

    Eloisa Sartori, Franco; Ivone, Panhoca.

    2007-12-01

    Full Text Available Segundo a literatura, a disfunção vestibular infantil pode afetar consideravelmente a habilidade de comunicação e o desempenho escolar. OBJETIVO: Estudar a função vestibular em crianças com dificuldades escolares e suas queixas vestibulares. ESTUDO DE CASO: Estudo Clínico com coorte transversal. MAT [...] ERIAL E MÉTODOS: Foram estudadas 50 crianças entre 7 e 12 anos, que freqüentavam escolas públicas de Piracicaba durante os anos de 2004 e 2005. Os procedimentos foram: anamnese; exame otorrinolaringológico; exame audiológico e avaliação vestibular. RESULTADOS: Das crianças avaliadas, 62,0% não relataram dificuldades escolares e 38,0% referiram ter dificuldades. A queixa geral mais comum foi de tontura (36,0%), e o sintoma mais comum no ambiente escolar foi de cefaléia (50,0%). Encontramos 74,2% de exame vestibular normal nas crianças sem dificuldades escolares e 31,6% de normalidade nas crianças com dificuldades. Encontramos alterações vestibulares de origem periférica irritativa tanto unilateral como bilateral, num total de 68,4% para as crianças com dificuldades escolares e um total de 25,8% para crianças sem dificuldades escolares. CONCLUSÃO: A queixa de atordoamento, o sintoma de náuseas e as dificuldades em ler e copiar apresentaram uma relação estatisticamente significante. Todas as alterações vestibulares encontradas foram de origem periférica irritativa. Os dados revelaram uma relação estatisticamente significante. Abstract in english According to the literature, child vestibular dysfunctions can considerably affect their ability of communication and school performance. AIM: to study the vestibular function in children with school difficulties and associated symptoms. CASE STUDY: Clinical study with transversal cohort. METHOD: Re [...] search subjects were 50 school children between 7 and 12 years old, from a public school of Piracicaba city, during the years 2004 and 2005. The procedure was based on: anamnesis; otorrinolaryngologic evaluation; audiologic evaluation and vestibular evaluation. RESULTS: All children assessed, 62.0% did not have school difficulties and 38.0% had school difficulties. Dizziness was the most common general complaint (36.0%). Migraine was the most common symptom regarding the school environment (50.0%). We found a high rate of normal vestibular condition (74.2%) in children without school difficulties and low normality rate in those with school difficulties (31.6%). All found vestibular alterations, both unilateral and bilateral, had been of peripheral irritative origin, accounting for 68.4% of cases for children with school difficulties and 25.8% for children without school difficulties. CONCLUSION: Dizziness, nausea, reading and copying difficulties presented a statistically significant relationship between the studied variables. All found vestibular alterations had been of peripheral irritative origin. Data showed a statistically significant relationship among variables.

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

    Directory of Open Access Journals (Sweden)

    Anna Paula Batista de Ávila Pires

    2013-02-01

    Full Text Available Pacientes após Acidente Vascular Cerebral (AVC podem apresentar sintomas otoneurológicos. OBJETIVO: Avaliar a função vestibular de pacientes com antecedente pessoal de AVC no território carotídeo. Desenho científico: estudo de coorte histórica com corte transversal. MÉTODO: Quarenta pacientes foram submetidos à anamnese, exame otorrinolaringológico, Dizziness Handicap Inventory e vectoeletronistagmografia. RESULTADOS: Anormalidades discretas dos movimentos sacádicos foram encontradas em 20 pacientes (50,0%; nove referiram desequilíbrio e um tontura. O ganho do rastreio pendular foi anormal em 17 casos (42,5%; seis referiram desequilíbrio e um tontura. Preponderância direcional anormal do nistagmoperrotatório ocorreu em dois casos (5,0%, que referiram desequilíbrio. A prova calórica identificou três casos (7,5% com predomínio labiríntico anormal e dois (5,0% com preponderância direcional anormal do nistagmo; os cinco casos relataram desequilíbrio. Dos 11 pacientes que não referiram manifestações de alteração do equilíbrio corporal, 10 apresentaram alterações nos movimentos sacádicos e no rastreio pendular e um apresentou exame vestibular normal. CONCLUSÃO: Pacientes com antecedente pessoal de AVC no território carotídeo podem apresentar tontura ou desequilíbrio corporal e sinais de comprometimento da motilidade ocular e da função vestibular.Stroke patients may present otoneurological symptoms. OBJECTIVE: To assess the vestibular function of subjects with a history of carotid territory stroke. METHOD: This historical cohort cross sectional study enrolled 40 patients; subjects answered the Dizziness Handicap Inventory, were interviewed and submitted to ENT examination and vectorelectronystagmography. RESULTS: Mild saccadic movement anomalies were seen in 20 patients (50.0%; nine complained of imbalance and dizziness. Abnormal smooth pursuit gain was seen in 17 cases (42.5%; six subjects reported imbalance and one complained of dizziness. Abnormal directional preponderance during rotational nystagmus was seen in two cases (5.0%, who also reported imbalance. Three patients (7.5% and two subjects (5.0% were found to have abnormal labyrinthine predominance and abnormal nystagmus directional preponderance respectively; all five individuals reported imbalance. Ten of the 11 patients without complaints of disordered balance had altered saccadic and smooth pursuit eye movements, while one had unaltered vestibular function. CONCLUSION: Patients with a history of carotid territory stroke may suffer from dizziness or imbalance and present signs of compromised eye motility and vestibular function.

  4. Experimental study on computed tomography of the vestibular aqueduct

    International Nuclear Information System (INIS)

    Investigations of the vestibular aqueduct by computed tomography were performed in dry temporal bones and patients with unilateral sensorineural hearing loss. Using an accessory table for a wider aperture of the whole body scanner (CT/T-8800), it was possible to position patient's head for a direct sagittal plane of the temporal region on CT scans. The scans were employed with a 1.5-mm-thick slice with 1.5-mm slice space. In this study, it was proven that this method displayed the vestibular aqueduct as clearly in patients as in dry temporal bones. However, one of the disadvantages of this technique was uncomfortable positioning for some patients. (author)

  5. Pharmacotherapy of vestibular and ocular motor disorders, including nystagmus

    OpenAIRE

    Strupp, Michael; Thurtell, Matthew J.; Shaikh, Aasef G.; Brandt, Thomas; Zee, David S.; Leigh, R. John

    2011-01-01

    We review current pharmacological treatments for peripheral and central vestibular disorders, and ocular motor disorders that impair vision, especially pathological nystagmus. The prerequisites for successful pharmacotherapy of vertigo, dizziness, and abnormal eye movements are the “4 D’s”: correct diagnosis, correct drug, appropriate dosage, and sufficient duration. There are seven groups of drugs (the “7 A’s”) that can be used: antiemetics; anti-inflammatory, anti-Ménière’s,...

  6. Galvanic Vestibular Stimulation in Hemi-Spatial Neglect

    Directory of Open Access Journals (Sweden)

    David Wilkinson

    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.

  7. Leptomeningeal Carcinomatosis of Gastric Cancer Misdiagnosed as Vestibular Schwannoma

    OpenAIRE

    Kim, Shin-Jae; Kwon, Jeong-Taik; Mun, Seog-Kyun; Hong, Young-Ho

    2014-01-01

    Gastric cancer is one of the most common causes of cancer-related death in Asian countries, including Korea. We experienced a case of leptomeningeal carcinomatosis (LC) from gastric cancer that was originally misdiagnosed as vestibular schwannoma based on the similar radiological characteristics. To our knowledge, LC from gastric cancer is very rare. In conclusion, our experience with this case suggests that clinicians should consider the possibility of delayed leptomeningeal metastasis when ...

  8. Afferent diversity and the organization of central vestibular pathways

    OpenAIRE

    Goldberg, Jay M.

    2000-01-01

    This review considers whether the vestibular system includes separate populations of sensory axons innervating individual organs and giving rise to distinct central pathways. There is a variability in the discharge properties of afferents supplying each organ. Discharge regularity provides a marker for this diversity since fibers which differ in this way also differ in many other properties. Postspike recovery of excitability determines the discharge regularity of an afferent and its sensitiv...

  9. Galvanic vestibular stimulation in hemi-spatial neglect

    Science.gov (United States)

    Wilkinson, David; Zubko, Olga; Sakel, Mohamed; Coulton, Simon; Higgins, Tracy; Pullicino, Patrick

    2014-01-01

    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 25 min, of sub-sensory, left-anodal right-cathodal noisy direct current (mean amplitude = 1 mA). 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 Behavioral Inattention Test. More remarkably, this change (mean change = 28%, SD = 18) was still evident 1 month later. Secondary analyses indicated an allied increase of 20% in median Barthel Index (BI) 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. PMID:24523679

  10. Vestibular Schwannoma in Patients with Sudden Sensorineural Hearing Loss

    OpenAIRE

    Lee, Jong Dae; Lee, Byung Don; Hwang, Sun Chul

    2011-01-01

    Sudden sensorineural hearing loss (SSNHL) has several etiologies. It may be a presenting symptom of vestibular schwannoma (VS). This study aimed to establish the incidence of VS in patients with SSNHL, and we report several unusual cases among these patients. We reviewed retrospectively the charts and magnetic resonance imaging (MRI) findings of all adult patients who presented with SSNHL between 2002 and 2008. We utilized three-dimensional fast imaging with steady-state acquisition temporal ...

  11. 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.

  12. Click-evoked vestibular activation in the Tullio phenomenon.

    OpenAIRE

    Colebatch, J. G.; Rothwell, J. C.; Bronstein, A.; Ludman, H.

    1994-01-01

    Click-evoked vestibulocollic reflexes were studied in a patient with a unilateral Tullio phenomenon (sound induced vestibular symptoms) and the findings were compared with those of a group of normal subjects. Compared with normal subjects, the reflexes elicited from her symptomatic side were large and had an abnormally low threshold, but retained a normal waveform. The click-evoked responses in this patient show changes consistent with her symptomatology and are indicative of a pathological i...

  13. Vestibular control of entorhinal cortex activity in spatial navigation

    OpenAIRE

    Francesca Sargolini

    2014-01-01

    Navigation in rodents depends on both self-motion (idiothetic) and external (allothetic) information. Idiothetic information has a predominant role when allothetic information is absent or irrelevant. The vestibular system is a major source of idiothetic information in mammals. By integrating the signals generated by angular and linear accelerations during exploration, a rat is able to generate and update a vector pointing to its starting place and to perform accurate return. This navigation ...

  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...

  15. Magnetic Vestibular Stimulation in Subjects with Unilateral Labyrinthine Disorders

    Directory of Open Access Journals (Sweden)

    BryanKevinWard

    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.

  16. Is surgical vestibular ablation necessary in disabling peripheral vertigo?

    OpenAIRE

    Mahadevaiah, A.; Parikh, Bhavin

    2008-01-01

    The use of intratympanic gentamicin is an easily performed office procedure for the conservative treatment of the Meniere’s disease patient who has failed medical therapy. The procedure provides excellent control for the symptom of vertigo and is one of the most successful methods in the treatment of vertigo due to inner ear disorders. Surgical ablation is no longer necessary for adequate control of vestibular symptoms and that chemical ablation/alteration may replace the need for surgical ...

  17. Measurement of oscillopsia induced by vestibular Coriolis stimulation.

    Science.gov (United States)

    Sanderson, Jeffrey; Oman, Charles M; Harris, Laurence R

    2007-01-01

    We demonstrate a new method for measuring the time constant of head-movement-contingent oscillopsia (HMCO) produced by vestibular Coriolis stimulation. Subjects briskly rotated their heads around pitch or roll axes whilst seated on a platform rotating at constant velocity. This induced a cross-coupled vestibular Coriolis illusion. Simultaneous with the head movement, a visual display consisting of either a moving field of white dots on a black background or superimposed on a subject-stationary horizon, or a complete virtual room with conventional furnishings appeared. The scene's motion was driven by a simplified computer model of the Coriolis illusion. Subjects either nulled (if visual motion was against the illusory body rotation) or matched (if motion was in the same direction as the illusory motion) the sensation with the exponentially slowing scene motion, by indicating whether its decline was too fast or too slow. The model time constant was approximated using a staircase technique. Time constants comparable to that of the Coriolis vestibular ocular reflex were obtained. Time constants could be significantly reduced by adding subject-stationary visual elements. This technique for measuring oscillopsia might be used to quantify adaptation to artificial gravity environments. In principle more complex models can be used, and applied to other types of oscillopsia such as are experienced by BPPV patients or by astronauts returning to Earth. PMID:18626139

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

    Science.gov (United States)

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

    1998-01-01

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

  19. Radiosurgical treatment of sporadic vestibular schwannomas: A prospective cohort study

    International Nuclear Information System (INIS)

    Objective: To analyze the preliminary experience of radiosurgery for Vestibular Schwannomas at the Pontificia Universidad Catolica de Chile. Material and methods: The first 17 patients with sporadic Vestibular Schwannomas treated by radiosurgery at our institution are reported. The marginal dose used was 12 to 12.5 Gy. prescribed at the 70 or 80 isodose fine. Patients were controlled at 6, 12 and 24 months with magnetic resonance, audiometric study and clinical examination. Results: In all of the 17 patients treated a decrease tumor enhancement on MR was demonstrated. In 16 patients (94%) a pattern of central tumor necrosis was observed during the firs year Actuarial useful hearing was maintained in 62.5% at 2 year after treatment. Facial nerve function was maintained in all of the 15 patients with normal function at treatment (100%). Trigeminal function was maintained in ah of the 14 patients (100%) with previous normal trigeminal function. The mean time to return to work or normal activities was 11.5 days after treatment. Conclusions: These preliminary results are comparable with results published in the literature and reinforce the demonstrate role of radiosurgery in the management of vestibular schwannomas

  20. Desempenho no vestibular, background familiar e evasão: evidências da UFPE

    Scientific Electronic Library Online (English)

    Breno, Sampaio; Yony, Sampaio; Euler P. G. de, Mello; Andrea S, Melo.

    2011-06-01

    Full Text Available Este artigo tem como objetivo compreender a decisão de evasão de estudantes universitários, assunto ainda pouco entendido no Brasil. Ênfase é dada à relação entre renda, desempenho no vestibular, evasão e a probabilidade de tentar nova carreira em novo vestibular. Atenção também é dada ao efeito esc [...] ola pública e cursinho pré-vestibular. Os resultados mostram que renda tem papel fundamental não só por proporcionar aos mais ricos melhores condições de estudo (escolas privadas, cursinhos), mas também por possibilitar ao aluno maior oportunidade de escolha da carreira que melhor se adeque as suas aptidões, favorecendo assim a permanência da desigualdade. Abstract in english The main objective of this paper is to understand university students' dropout decision, which is an area still not well studied in Brazil. Particular atention is given to the relationship between income, performance, dropout and the decision to re-take the exam in an attempt to switch careers. The [...] effect of public schools and tutoring classes are also estimated. Results show that income not only provide the students with a better study environment (through private schools and tutoring classes) but also allow for the posibility of trying different careers until a better student-career match is made, favoring the persistence of inequality.

  1. Does betahistine treatment have additional benefits to vestibular rehabilitation?

    Science.gov (United States)

    Karapolat, Hale; Celebisoy, Nese; Kirazli, Yesim; Bilgen, Cem; Eyigor, Sibel; Gode, Sercan; Akyuz, Aycan; Kirazli, Tayfun

    2010-08-01

    The aim of this study was to investigate the effect of high-dose betahistine treatment added to vestibular rehabilitation (VR) on the disability, balance and postural stability in patients with unilateral vestibular disorder. The VR group (group 1, n = 24) and the VR + betahistine group (group 2, n = 23) were analyzed retrospectively. All patients were evaluated before and after an 8-week customized VR in terms of disability (Dizziness Handicap Inventory, DHI), dynamic balance [Dynamic Gait Index (DGI)] and postural stability (static posturography). In group 1 and group 2, differences between DHI, DGI and falling index score on static posturography before and after the exercise program were significant (p < 0.05). In addition, a significant difference was detected only in group 2 in the variables evaluated in static posturography-Fourier 4 analysis (p < 0.05). Both VR and betahistine + VR have a positive effect on disability and balance in patients with unilateral vestibular disorder. Betahistine treatment added to VR was effective in increasing postural stability. PMID:20567979

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

    Science.gov (United States)

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

    1994-01-01

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

  3. Glutamatergic signaling at the vestibular hair cell calyx synapse.

    Science.gov (United States)

    Sadeghi, Soroush G; Pyott, Sonja J; Yu, Zhou; Glowatzki, Elisabeth

    2014-10-29

    In the vestibular periphery a unique postsynaptic terminal, the calyx, completely covers the basolateral walls of type I hair cells and receives input from multiple ribbon synapses. To date, the functional role of this specialized synapse remains elusive. There is limited data supporting glutamatergic transmission, K(+) or H(+) accumulation in the synaptic cleft as mechanisms of transmission. Here the role of glutamatergic transmission at the calyx synapse is investigated. Whole-cell patch-clamp recordings from calyx endings were performed in an in vitro whole-tissue preparation of the rat vestibular crista, the sensory organ of the semicircular canals that sense head rotation. AMPA-mediated EPSCs showed an unusually wide range of decay time constants, from 500 ms. Decay time constants of EPSCs increased (or decreased) in the presence of a glutamate transporter blocker (or a competitive glutamate receptor blocker), suggesting a role for glutamate accumulation and spillover in synaptic transmission. Glutamate accumulation caused slow depolarizations of the postsynaptic membrane potentials, and thereby substantially increased calyx firing rates. Finally, antibody labelings showed that a high percentage of presynaptic ribbon release sites and postsynaptic glutamate receptors were not juxtaposed, favoring a role for spillover. These findings suggest a prominent role for glutamate spillover in integration of inputs and synaptic transmission in the vestibular periphery. We propose that similar to other brain areas, such as the cerebellum and hippocampus, glutamate spillover may play a role in gain control of calyx afferents and contribute to their high-pass properties. PMID:25355208

  4. Potencial evocado miogênico vestibular: novas perspectivas diagnósticas em esclerose múltipla / Vestibular evoked myogenic potential: new perspectives in multiple sclerosis

    Scientific Electronic Library Online (English)

    Renata Chade, Aidar; Fábio A., Suzuki.

    2005-02-01

    Full Text Available OBJETIVO: Avaliar o potencial evocado miogênico vestibular em pacientes com esclerose múltipla, como método de auxílio diagnóstico. FORMA DE ESTUDO: Caso-controle. MATERIAL E MÉTODO: Estudamos um grupo-controle (n=15) de indivíduos normais e um grupo experimental (n=15) que foi composto por paciente [...] s com diagnóstico de esclerose múltipla. Ambos os grupos foram submetidos ao exame de potencial evocado miogênico vestibular. Em cada orelha foram aplicados 200 estímulos na forma de cliques e repetidos por 2 ciclos consecutivos com objetivo de avaliar a reprodutibilidade. Os eletrodos ativos de superfície foram colocados no S‡superior do músculo esternocleidomastoideo e de referência na borda anterior da clavícula ipsilateral. Os indivíduos foram instruídos à rotação lateral da cabeça em direção contralateral à orelha estimulada. RESULTADOS: Obtivemos no potencial evocado miogênico vestibular respostas rápidas, reprodutíveis e bifásicas. A latência das ondas P1 e N2 e amplitude P1-N2 apresentaram um maior valor no grupo experimental quando comparada com o grupo-controle. Não observamos diferença significativa nas respostas das ondas P1 e N2 e amplitude P1-N2 quando comparamos as orelhas. Verificamos que os indivíduos com esclerose múltipla apresentaram ausência de respostas em 30% dos casos. Ao avaliarmos os indivíduos do grupo experimental com sintomas otoneurológicos e compararmos com os pacientes sem sintomas, observamos que a latência da onda P1, N2 e amplitude P1-N2 estiveram maiores nos casos sintomáticos. CONCLUSÃO: O potencial evocado miogênico vestibular foi considerado um bom método de auxílio diagnóstico da via vestíbulo-espinal nos casos de esclerose múltipla. Abstract in english AIM: To evaluate vestibular evoked myogenic potentials in patients with multiple sclerosis as method of diagnostic support. STUDY DESIGN: Case-control. MATERIAL AND METHOD: We studied a group of normal individuals (n=15) and a Studied group (n=15) that comprised patients with diagnosis of multiple s [...] clerosis. Both groups were submitted to vestibular evoked myogenic potential exam. In each ear it was applied 200 stimuli by clicks and repeated for 2 consecutive cycles with the purpose of evaluating reproducibility. The active electrode of surface was put on the superior S‡of sternocleidomastoid muscle and the reference electrode on the anterior border of the clavicle. The individuals were instructed to rotate theirs head to the opposite side to the stimulated ear. RESULTS: Vestibular evoked myogenic potential responses were prompt, reproducible and biphasic. The latency of wave P1 and N2 and P1-N2 amplitude showed a higher value in the studied group when compared with the normal group. There was no significant difference when the ears were compared in P1 and N2 amplitude. We noticed that individuals with multiple sclerosis showed no response in 30% of the cases. In evaluating the individuals of the Studied group with otoneurology symptoms and compared with individuals without symptoms, it was observed that P1 and N2 latencies and P1-N2 amplitude were higher in symptomatic cases. CONCLUSION: Vestibular evoked myogenic potential was considered a good method of diagnostic support of vestibulospinal tract in cases of multiple sclerosis.

  5. Multichannel Vestibular Prosthesis Employing Modulation of Pulse Rate and Current with Alignment Precompensation Elicits Improved VOR Performance in Monkeys

    OpenAIRE

    Davidovics, Natan S.; Rahman, Mehdi A.; Dai, Chenkai; Ahn, JoongHo; FRIDMAN, GENE Y.; DELLA SANTINA, CHARLES C.

    2013-01-01

    An implantable prosthesis that stimulates vestibular nerve branches to restore the sensation of head rotation and the three-dimensional (3D) vestibular ocular reflex (VOR) could benefit individuals disabled by bilateral loss of vestibular sensation. Our group has developed a vestibular prosthesis that partly restores normal function in animals by delivering biphasic current pulses via electrodes implanted in semicircular canals. Despite otherwise promising results, this approach has been limi...

  6. Reabilitação vestibular em pacientes idosos portadores de vertigem posicional paroxística benigna / Vestibular rehabilitation in elderly patients with benign paroxysmal positional vertigo

    Scientific Electronic Library Online (English)

    Carolina R., Resende; Carlos K., Taguchi; Juliane G. de, Almeida; Reginaldo R., Fujita.

    2003-08-01

    Full Text Available A Vertigem Posicional Paroxística Benigna (VPPB) é um distúrbio vestibular no qual os pacientes relatam breves momentos de vertigem e/ou leve instabilidade postural, ocasionados por uma mudança brusca na movimentação cefálica ou corporal. OBJETIVO: Verificar o benefício da reabilitação vestibular, r [...] ealizada em grupo, em pacientes idosos portadores de VPPB. FORMA DE ESTUDO: Clínico prospectivo. MATERIAL E MÉTODO: Foram selecionados aleatoriamente 16 pacientes portadores de VPPB, todos medicados com extrato de Gingko-biloba (40mg de 12/12h) durante 30 dias. Oito deles, que formaram o Grupo Experimental, além do medicamento, foram submetidos à reabilitação vestibular e oito compuseram o Grupo Controle que não realizaram nenhum tipo de exercício. Para avaliação do benefício aplicamos a Escala de Atividades de Vida Diária e Desordens Vestibulares proposta por Cohen e Kimball. Para a análise estatística utilizamos o teste t-student. CONCLUSÃO: Nossos resultados apontaram benefício promovido pela reabilitação vestibular em grupo no tratamento de idosos portadores de VPPB; a avaliação qualitativa mostrou-se instrumento importante para a avaliação de benefício para o tratamento proposto; e a reabilitação vestibular em grupo mostrou ser uma excelente estratégia terapêutica. Abstract in english The Benign Paroxysmal Positional Vertigo (BPPV) is a vestibular disorder where the patients complain brief moments of vertigo and/or present postural instability, caused by a brusque change in the cephalic or body movement. AIM: The objective of the present study is certificate the benefit of the ve [...] stibular rehabilitation in elderly people with Benign Paroxysmal Positional Vertigo. STUDY DESIGN: Clinical prospective. MATERIAL AND METHOD: Sixteen patients with BPPV were thread with extract of Ginkgo-biloba (40mg of 12/12h) during 30 days. Eight patients (the Experimental Group) were submitted to vestibular rehabilitation and the other called Control Group, didn't perform any kind of exercises. In order to perform the evaluation of the benefit we used the Scale of Activity of Daily Life and Vestibular Disorders by Kohen and Kimball, and used the t-student test to statistical analysis. CONCLUSION: The vestibular rehabilitation in group showed benefit in the treatment in the Experimental Group; the Scale of Activity of Daily Life and Vestibular Disorders, was an important tool for the qualitative evaluation in our rehabilitation proposal and the vestibular rehabilitation in group showed as an excellent therapeutic strategy.

  7. Valor clínico dos nistagmos posicional e de posicionamento no diagnóstico vestibular de idosos / Clinical features of the positional nystagmus and the positioning nystagmus on vestibular diagnosis in elderly

    Scientific Electronic Library Online (English)

    Carlos Kazuo, Taguchi; Lucas Vieira, Alves; Rafael Oliveira, Gois; Priscila Feliciano, Oliveira.

    2013-08-01

    Full Text Available OBJETIVO: estudar a importância da pesquisa do nistagmo posicional e de posicionamento na avaliação vestibular em idosos. MÉTODO: estudo retrospectivo e descritivo. Foram analisados 70 prontuários de pacientes com idade superior a 60 anos submetidos à avaliação vestibular, divididos em dois grupos: [...] grupo A composto por 35 prontuários com resultados da avaliação do nistagmo posicional e diagnóstico vestibular e grupo B composto por 35 prontuários com resultados da avaliação do nistagmo de posicionamento e diagnóstico vestibular. RESULTADOS: a pesquisa do nistagmo de posição destacou uma parcela significante de disfunção vestibular periférica no Grupo A e a pesquisa do nistagmo de posicionamento um número expressivo de vertigem posicional no Grupo B, que, ainda, apresentou prevalência de resultados normais. Não foram encontradas diferenças significantes entre os dois grupos para as variáveis, gênero e idade. CONCLUSÃO: a pesquisa do nistagmo de posição auxiliou na identificação de alterações vestibulares periféricas e a de posicionamento identificou a vertigem posicional, revelando que a introdução deste último parâmetro de avaliação foi positiva, porém não substitui o a pesquisa do nistagmo de posição. Abstract in english PURPOSE: to study the importance of positional nystagmus and positioning in vestibular assessment in the elderly. METHOD: retrospective descriptive study. It was analyzed evaluation charts of 70 patients aged over 60 years submitted of vestibular assessment. These charts were divided into two groups [...] : group A composed of 35 charts with evaluation results of the positional nystagmus and vestibular diagnosis and group B with 35 charts with the results of the evaluation positional nystagmus and vestibular diagnosis. RESULTS: nystagmus position highlighted a significant number of peripheral vestibular dysfunction in Group A and nystagmus positioning a large number of positional vertigo in Group B, in which, also, was founded a prevalence of normal results. No significant differences it was found between the two groups for the variables, gender and age. CONCLUSION: the nystagmus position test allowed identifying peripheral vestibular disorders and positioning nystagmus to identify positional vertigo, pointing that the introduction of the latter test was useful but not replace the nystagmus position evaluation.

  8. Galvanic-induced postural movements as a test of vestibular function in humans.

    Science.gov (United States)

    Cass, S P; Redfern, M S; Furman, J M; DiPasquale, J J

    1996-04-01

    Galvanic stimulation produces a postural sway and eye movements in humans. Since galvanic currents are thought to exert their effect at the trigger zone of the vestibular nerve, an intact vestibular nerve should be necessary to produce a response. We have used galvanic stimulation in humans to test the hypothesis that intact vestibular nerve fibers are required to obtain a postural away response. Experimental subjects included normal subjects, patients who had undergone resection of an acoustic neuroma, and patients who had undergone vestibular neurectomy and surgical labyrinthectomy. Our results support the hypothesis that an intact vestibular nerve is necessary to produce a response. Moreover, two patients with recurrent vertigo following vestibular neurectomy and labyrinthectomy, who had absent ice-water caloric test responses in the operated ears, were found to have a positive galvanic response. This result suggested that their recurrent vertigo was based on intact residual vestibular nerve fibers. Although previous research has not yielded a routine clinical use for galvanic stimulation, our results suggest that galvanic stimulation of the vestibular system can provide unique and valuable diagnostic information. PMID:8614216

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

    Directory of Open Access Journals (Sweden)

    MatteoCandidi

    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.

  10. [Diseases of the peripheral vestibular system: contribution of ENT medical diagnostics and therapy].

    Science.gov (United States)

    Pabst, F; Machetanz, J; Gerk, U; Simonis, G; Schellong, S

    2015-01-01

    The most common types of vertigo caused by diseases of the peripheral vestibular system are benign paroxysmal positional vertigo (BPPV), Meniere's disease and vestibular neuritis. A thorough examination of the medical history and clinical examination are usually sufficient for the differential diagnostics. Treatment includes differentiated repositioning maneuvers, medicinal treatment and physiotherapy. PMID:25502656

  11. Concurrent Vestibular Schwannoma and Meningioma Mimicking a Single Cerebellopontine Angle Tumor

    OpenAIRE

    Kutz, Joe Walter; Barnett, Samuel L.; Hatanpaa, Kimmo J.; Mendelsohn, Dianne B.

    2009-01-01

    Vestibular schwannomas account for ~;80% of cerebellopontine angle (CPA) tumors, with meningiomas being the second most common tumor of the CPA. The occurrence of both a schwannoma and a meningioma in the cerebellopontine angle is rare. After obtaining Institutional Review Board approval, we present a case of a concurrent vestibular schwannoma and meningioma in the CPA mimicking a single tumor.

  12. The effects of stochastic galvanic vestibular stimulation on human postural sway.

    Science.gov (United States)

    Pavlik, A E; Inglis, J T; Lauk, M; Oddsson, L; Collins, J J

    1999-02-01

    Galvanic vestibular stimulation serves to modulate the continuous firing level of the peripheral vestibular afferents. It has been shown that the application of sinusoidally varying, bipolar galvanic currents to the vestibular system can lead to sinusoidally varying postural sway. Our objective was to test the hypothesis that stochastic galvanic vestibular stimulation can lead to coherent stochastic postural sway. Bipolar binaural stochastic galvanic vestibular stimulation was applied to nine healthy young subjects. Three different stochastic vestibular stimulation signals, each with a different frequency content (0-1 Hz, 1-2 Hz, and 0-2 Hz), were used. The stimulation level (range 0.4-1.5 mA, peak to peak) was determined on an individual basis. Twenty 60-s trials were conducted on each subject - 15 stimulation trials (5 trials with each stimulation signal) and 5 control (no stimulation) trials. During the trials, subjects stood in a relaxed, upright position with their head facing forward. Postural sway was evaluated by using a force platform to measure the displacements of the center of pressure (COP) under each subject's feet. Cross-spectral measures were used to quantify the relationship between the applied stimulus and the resulting COP time series. We found significant coherency between the stochastic vestibular stimulation signal and the resulting mediolateral COP time series in the majority of trials in 8 of the 9 subjects tested. The coherency results for each stimulation signal were reproducible from trial to trial, and the highest degree of coherency was found for the 1- to 2-Hz stochastic vestibular stimulation signal. In general, for the nine subjects tested, we did not find consistent significant coherency between the stochastic vestibular stimulation signals and the anteroposterior COP time series. This work demonstrates that, in subjects who are facing forward, bipolar binaural stochastic galvanic stimulation of the vestibular system leads to coherent stochastic mediolateral postural sway, but it does not lead to coherent stochastic anteroposterior postural sway. Our finding that the coherency was highest for the 1- to 2-Hz stochastic vestibular stimulation signal may be due to the intrinsic dynamics of the quasi-static postural control system. In particular, it may result from the effects of the vestibular stimulus simply being superimposed upon the quiet-standing COP displacements. By utilizing stochastic stimulation signals, we ensured that the subjects could not predict a change in the vestibular stimulus. Thus, our findings indicate that subjects can act as "responders" to galvanic vestibular stimulation. PMID:9989432

  13. Electromyographic activity of sternocleidomastoid and masticatory muscles in patients with vestibular lesions

    Scientific Electronic Library Online (English)

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

    2008-12-01

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

  14. Electromyographic activity of sternocleidomastoid and masticatory muscles in patients with vestibular lesions

    Directory of Open Access Journals (Sweden)

    Gianluca M. Tartaglia

    2008-12-01

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

  15. AVALIAÇÃO DA EFICÁCIA E SEGURANÇA DO DICLORIDRATO DE BETAISTINA EM CÃES COM DISTÚRBIOS VESTIBULARES

    Directory of Open Access Journals (Sweden)

    BRUM, Alexandre Martini

    2009-11-01

    Full Text Available Vestibular disease is in dogs and cats, and it may be the result of central or peripheraldisease. The pathophysiology is unknown, however it can be related to an abnormal dynamic ofendolymphatic fluid or neuritis of the vestibular portion of the VIII cranial nerve. The recovery ofneurological sings is slow and, in chronic cases, the neurological deficits can be irreversible. Thebetahistine dihydrochloride is a drug used in humans with peripheral vestibular disorders and was used infour dogs with vestibular syndrome. The results showed clinical improvement in 7 to 10 days of treatmentand completed recovery in 20 to 30 days. One year after the treatment, the dogs didn’t have recurrence ofthe syndrome. The use of betahistine dihydrochloride in dogs with peripheral vestibular syndrome showsrapid clinical recover, without laboratorial abnormalities or recurrence of the clinical signs.

  16. Advances in the diagnosis and treatment of vestibular disorders: psychophysics and prosthetics.

    Science.gov (United States)

    Lewis, Richard F

    2015-04-01

    Although vestibular disorders are common and often disabling, they remain difficult to diagnose and treat. For these reasons, considerable interest has been focused on developing new ways to identify peripheral and central vestibular abnormalities and on new therapeutic options that could benefit the numerous patients who remain symptomatic despite optimal therapy. In this review, I focus on the potential utility of psychophysical vestibular testing and vestibular prosthetics. The former offers a new diagnostic approach that may prove to be superior to the current tests in some circumstances; the latter may be a way to provide the brain with information about head motion that restores some elements of the information normally provided by the vestibular labyrinth. PMID:25834036

  17. Neuroendocrine cells in the vestibular glands of the genital tract of cows and pigs.

    Science.gov (United States)

    Russo, Finizia; Vittoria, Alfredo

    2006-01-01

    The presence of neuroendocrine (NE) cells producing biogenic amines and hormonal peptides has been investigated in the vestibular glands of the genital tracts of cows and pigs using immunohistochemistry. NE cells containing chromogranin A-, serotonin-, cholecystokinin- and somatostatin-immunoreactive material were found in both major and minor vestibular glands. Such cells were numerous, scattered in the acini and excretory duct epithelium, small in size and rounded, triangular or bipolar in shape. The function of the NE vestibular cells has been related to the secretory activity of the glands and to a sexual climax induction mechanism involving the stimulation of 5HT(3) receptors of vestibular nociceptor nerve fibers. The role of NE cells in small cell carcinomas of the vestibular glands is a topic for further investigation owing to possible parallelism between this type of tumor and the small cell carcinoma of the human prostate. PMID:16997356

  18. Naturally-occurring canine herpesvirus-1 infection of the vestibular labyrinth and ganglion of dogs.

    Science.gov (United States)

    Parzefall, Birgit; Fischer, Andrea; Blutke, Andreas; Schmahl, Wolfgang; Matiasek, Kaspar

    2011-07-01

    Although the involvement of herpesviruses in vestibular disease of humans has been recognised for many years, knowledge of such a link in companion animal species is restricted to cats. This study was conducted to assess the prevalence of canine herpesvirus-1 (CaHV-1) infection of the vestibular labyrinth (VL) and vestibular ganglion (VG) of dogs by PCR. 'Field' herpesvirus was detected in the VL of 17% and in the VG of 19% of 52 dogs, respectively. None of the 11 dogs with infected VG and/or VL exhibited signs of vestibular disease, whereas clinical signs in the remaining three animals were attributable to intra-cranial neoplasia. As reported for other species, the putative role of herpesvirus infection in canine vestibular disease requires further elucidation. PMID:20696601

  19. 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.

  20. Alignment of angular velocity sensors for a vestibular prosthesis

    Directory of Open Access Journals (Sweden)

    DiGiovanna Jack

    2012-02-01

    Full Text Available Abstract Vestibular prosthetics transmit angular velocities to the nervous system via electrical stimulation. Head-fixed gyroscopes measure angular motion, but the gyroscope coordinate system will not be coincident with the sensory organs the prosthetic replaces. Here we show a simple calibration method to align gyroscope measurements with the anatomical coordinate system. We benchmarked the method with simulated movements and obtain proof-of-concept with one healthy subject. The method was robust to misalignment, required little data, and minimal processing.

  1. Vestibular-related neuroscience and manned space flight

    Science.gov (United States)

    Igarashi, Makoto

    1988-01-01

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

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

    OpenAIRE

    Dai, Chenkai; FRIDMAN, GENE Y.; Chiang, Bryce; Davidovics, Natan; Melvin, Thuy-Anh; Cullen, Kathleen E.; DELLA SANTINA, CHARLES C.

    2011-01-01

    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 a...

  3. Dos potenciais evocados miogênicos vestibulares nas orelhas comprometida e assintomática na Doença de Ménière unilateral / Vestibular evoked myogenic potentials in affected and asymptomatic ears in unilateral Ménière's Disease

    Scientific Electronic Library Online (English)

    Súnia, Ribeiro; Roberta R. de, Almeida; Heloisa H., Caovilla; Maurício M., Ganança.

    2005-02-01

    Full Text Available Verificar se os potenciais evocados miogênicos vestibulares podem apresentar anormalidades na orelha comprometida e na orelha assintomática em pacientes com hipótese diagnóstica de doença de Ménière definida unilateral. FORMA DE ESTUDO: Transversal coorte. MATERIAL E MÉTODO: Foram avaliados os poten [...] ciais evocados miogênicos vestibulares de 20 pacientes com doença de Ménière definida unilateral. A seleção dos indivíduos baseou-se na história e na avaliação clínica sugestivas de doença de Ménière definida unilateral, e eletrococleografia com anormalidades na orelha comprometida. Os potenciais evocados miogênicos vestibulares foram avaliados em ambas as orelhas de cada paciente por meio da latência absoluta de p13 e n23, diferença interaural da latência dos picos p13 e n23 e índice de assimetria da amplitude de p13-n23. RESULTADO: Os potenciais evocados miogênicos vestibulares estavam alterados em 35,0% das orelhas comprometidas e em 25,0% das orelhas assintomáticas. As alterações foram: ausência de resposta em sete casos, aumento da latência absoluta de p13 em três casos, e aumento do índice de assimetria da amplitude em um caso. CONCLUSÃO: Os potenciais evocados miogênicos vestibulares podem apresentar anormalidades nas orelhas comprometida e assintomática de pacientes com hipótese diagnóstica de doença de Ménière definida unilateral. Abstract in english AIM: To verify whether vestibular evoked myogenic potentials can present abnormalities in the affected ear and in the asymptomatic ear in patients with diagnosis of unilateral Ménière's disease. STUDY DESIGN: Transversal cohort. MATERIAL AND METHOD: The vestibular evoked myogenic potentials of 20 pa [...] tients with unilateral Ménière's disease were analyzed. The selection of individuals was based on the history and in clinical evaluation suggestive of unilaterally defined Ménière's disease, and with electrocochleography abnormalities in the affected ear. Vestibular evoked myogenic potentials were evaluated in both ears of each patient through absolute latencies of p13 and n23, interaural difference of latency of peaks p13 and n23 and amplitude p13-n23 asymmetry rate. RESULTS: Vestibular evoked myogenic potentials were altered in 35.0% of the affected ears and in 25.0% of the asymptomatic ears. The alterations were: absence of responses in seven cases, prolongation of p13 latency in three cases, and increase in interaural amplitude difference ratio in one case. CONCLUSION: The vestibular evoked myogenic potentials can present abnormalities in the affected and asymptomatic ears in patients with diagnosis of unilaterally defined Ménière's disease.

  4. Facial paralysis and vestibular syndrome in feedlot cattle in Argentina Paralisia facial e síndrome vestibular de bovinos em confinamento

    Directory of Open Access Journals (Sweden)

    Ernesto Odriozola

    2009-11-01

    Full Text Available This paper reports 6 outbreaks of neurological disease associated with paralysis of the facial and vestibulocochlear nerves caused by intracranial space occupying lesions in feedlot cattle. The clinical signs observed were characterized by head tilt, uni or bilateral drooping and paralysis of the ears, eyelid ptosis, keratoconjunctivitis, and different degrees of ataxia. Morbidity and mortality rates ranged from 1.1 to 50% and 0 to 1%, respectively. Gross lesions observed included yellow, thickened leptomeninges, and marked enlargement of the roots of cranial nerves VII (facial and VIII (vestibulocochlear. Histopathologically, there was severe, chronic, granulomatous meningitis and, in one case, chronic, granulomatous neuritis of the VII and VIII cranial nerves. Attempts to identify bacterial, viral, or parasitic agents were unsuccessful. Based on the morphologic lesions, the clinical condition was diagnosed as facial paralysis and vestibular syndrome associated with space occupying lesions in the meninges and the cranial nerves VII and VIII. Feedlot is a practice of growing diffusion in our country and this is a first report of outbreaks of facial paralysis and vestibular disease associated with space occupying lesions in Argentina.Descrevem-se 6 surtos de uma doença neurológica com paralisia dos nervos facial e vestibulo-coclear causada por lesões intracraniais que ocupam espaço em bovinos em confinamento. Os sinais clínicos foram desvio da cabeça, queda e paralisia das orelhas, ptose palpebral, ceratoconjuntivite e diferentes graus de ataxia. As taxas de morbidade e mortalidade foram de 1.1%-50% e de 0-1%, respectivamente. As lesões macroscópicas incluíram engrossamento das meninges, que se apresentavam amareladas, e marcado engrossamento das raízes dos nervos cranianos VII (facial e VIII (vestíbulo-coclear. Histologicamente observaram-se meningite crônica granulomatosa e, em um caso, neurite granulomatosa crônica do VII e VIII pares cranianos. Cultivos para bactérias ou vírus resultaram negativos. De acordo com as lesões observadas o quadro clínico foi diagnosticado como paralisia facial e síndrome vestibular associadas a lesões que ocupam espaço nas meninges e nervos cranianos VII e VIII. O confinamento é uma prática em expansão na Argentina e este é o primeiro relato, neste país, de surtos de paralisia facial e síndrome vestibular associados com lesões que ocupam espaço.

  5. Facial paralysis and vestibular syndrome in feedlot cattle in Argentina / Paralisia facial e síndrome vestibular de bovinos em confinamento

    Scientific Electronic Library Online (English)

    Ernesto, Odriozola; Santiago, Diab; Pablo, Khalloub; Adriana, Bengolea; Luciana, Lázaro; Darío, Caffarena; Luis, Pérez; Germán, Cantón; Carlos, Campero.

    2009-11-01

    Full Text Available Descrevem-se 6 surtos de uma doença neurológica com paralisia dos nervos facial e vestibulo-coclear causada por lesões intracraniais que ocupam espaço em bovinos em confinamento. Os sinais clínicos foram desvio da cabeça, queda e paralisia das orelhas, ptose palpebral, ceratoconjuntivite e diferente [...] s graus de ataxia. As taxas de morbidade e mortalidade foram de 1.1%-50% e de 0-1%, respectivamente. As lesões macroscópicas incluíram engrossamento das meninges, que se apresentavam amareladas, e marcado engrossamento das raízes dos nervos cranianos VII (facial) e VIII (vestíbulo-coclear). Histologicamente observaram-se meningite crônica granulomatosa e, em um caso, neurite granulomatosa crônica do VII e VIII pares cranianos. Cultivos para bactérias ou vírus resultaram negativos. De acordo com as lesões observadas o quadro clínico foi diagnosticado como paralisia facial e síndrome vestibular associadas a lesões que ocupam espaço nas meninges e nervos cranianos VII e VIII. O confinamento é uma prática em expansão na Argentina e este é o primeiro relato, neste país, de surtos de paralisia facial e síndrome vestibular associados com lesões que ocupam espaço. Abstract in english This paper reports 6 outbreaks of neurological disease associated with paralysis of the facial and vestibulocochlear nerves caused by intracranial space occupying lesions in feedlot cattle. The clinical signs observed were characterized by head tilt, uni or bilateral drooping and paralysis of the ea [...] rs, eyelid ptosis, keratoconjunctivitis, and different degrees of ataxia. Morbidity and mortality rates ranged from 1.1 to 50% and 0 to 1%, respectively. Gross lesions observed included yellow, thickened leptomeninges, and marked enlargement of the roots of cranial nerves VII (facial) and VIII (vestibulocochlear). Histopathologically, there was severe, chronic, granulomatous meningitis and, in one case, chronic, granulomatous neuritis of the VII and VIII cranial nerves. Attempts to identify bacterial, viral, or parasitic agents were unsuccessful. Based on the morphologic lesions, the clinical condition was diagnosed as facial paralysis and vestibular syndrome associated with space occupying lesions in the meninges and the cranial nerves VII and VIII. Feedlot is a practice of growing diffusion in our country and this is a first report of outbreaks of facial paralysis and vestibular disease associated with space occupying lesions in Argentina.

  6. Morphological and Histochemical Analysis of the Human Vestibular Fold / Análisis Morfológico e Histoquímico del Pliegue Vestibular Humano

    Scientific Electronic Library Online (English)

    Heraldo Lorena, Guida; Neivo Luiz, Zorzetto.

    2007-09-01

    Full Text Available Fue realizado un estudio morfológico e histoquímico del pliegue vestibular humano a través de técnicas histológicas de rutina. Cortes histológicos de 7µm de grosor fueron teñidos con HE y Calleja, los cuales revelaron la presencia de fibras colágenas, elásticas y glándulas seromucosas en el pliegue [...] vestibular. También fueron identificadas fibras musculares que constituyen el músculo ventricular. Los análisis ultraestruturales de la capa epitelial realizados a través de microscopía electrónica de barrido, mostraron la presencia de células ciliadas, caliciformes y abertura de conductos glandulares en la superficie epitelial. Los análisis histoquímicos fueron realizados con músculos ventriculares sometidos a las reacciones NADH-TR, SDH y mATPasa. En base en estas reacciones se observó que el músculo está constituido por tres tipos de fibras musculares SO, FOG y FG, distribuidas en la forma de mosaico. La frecuencia de las fibras fue de 22,7%, 69,9% e 7,4%, respectivamente. La mayor frecuencia de fibras oxidativas SO+FOG caracterizó al músculo, con metabolismo aeróbico, resistente a la fatiga. El músculo ventricular fue considerado como rápido. El estudio de las uniones neuromusculares, después de la reacción de la esterasa inespecífica, evidenció que estas uniones son del tipo placa y de ocurrencia múltiple en el músculo ventricular Abstract in english A morphological and histochemical study of the human vestibular fold was carried out using routine histological techniques. Seven µm-thick histo logical sections stained with hematoxylin-eosin (HE) and Callej a showed the presence of elastic collagen fibers and seromucous glands in the vestibular fo [...] ld. Muscle fibers forming the ventricular muscle were also identified. Ultrastructural analyses of the epithelial layer by scanning electron microscopy (SEM) revealed ciliated cells and gland ducts opening on the epithelial surface. Histochemical analyses were performed on ventricular muscles submitted to nicotinamide-adenine-dinucleotide tetrazolium reductase (NADH-TR), succinate dehydrogenase (SDH), and myofibrillar adenosine triphosphatase (mATPase) reactions. Based on these reactions, it was observed that the muscle is formed by three types of muscle fibers: slow-twitch oxidative (SO), fast-twitch oxydative glycolytic (FOG) and fast-twitch glycolytic (FG) fibers distributed in a mosaic pattern. The fiber frequency was 22.7%, 69.9% and 7.4%, respectively. The higher frequency of SO and FOG fibers characterized the muscle as having aerobic metabolism and resistance to fatigue. The ventricular muscle was considered fast. The study of the neuromuscular junctions performed after nonspecific esterase reaction showed that they are of the en-plaque type and have multiple occurrences in the ventricular muscle

  7. Morphological and Histochemical Analysis of the Human Vestibular Fold Análisis Morfológico e Histoquímico del Pliegue Vestibular Humano

    Directory of Open Access Journals (Sweden)

    Heraldo Lorena Guida

    2007-09-01

    Full Text Available A morphological and histochemical study of the human vestibular fold was carried out using routine histological techniques. Seven µm-thick histo logical sections stained with hematoxylin-eosin (HE and Callej a showed the presence of elastic collagen fibers and seromucous glands in the vestibular fold. Muscle fibers forming the ventricular muscle were also identified. Ultrastructural analyses of the epithelial layer by scanning electron microscopy (SEM revealed ciliated cells and gland ducts opening on the epithelial surface. Histochemical analyses were performed on ventricular muscles submitted to nicotinamide-adenine-dinucleotide tetrazolium reductase (NADH-TR, succinate dehydrogenase (SDH, and myofibrillar adenosine triphosphatase (mATPase reactions. Based on these reactions, it was observed that the muscle is formed by three types of muscle fibers: slow-twitch oxidative (SO, fast-twitch oxydative glycolytic (FOG and fast-twitch glycolytic (FG fibers distributed in a mosaic pattern. The fiber frequency was 22.7%, 69.9% and 7.4%, respectively. The higher frequency of SO and FOG fibers characterized the muscle as having aerobic metabolism and resistance to fatigue. The ventricular muscle was considered fast. The study of the neuromuscular junctions performed after nonspecific esterase reaction showed that they are of the en-plaque type and have multiple occurrences in the ventricular muscleFue realizado un estudio morfológico e histoquímico del pliegue vestibular humano a través de técnicas histológicas de rutina. Cortes histológicos de 7µm de grosor fueron teñidos con HE y Calleja, los cuales revelaron la presencia de fibras colágenas, elásticas y glándulas seromucosas en el pliegue vestibular. También fueron identificadas fibras musculares que constituyen el músculo ventricular. Los análisis ultraestruturales de la capa epitelial realizados a través de microscopía electrónica de barrido, mostraron la presencia de células ciliadas, caliciformes y abertura de conductos glandulares en la superficie epitelial. Los análisis histoquímicos fueron realizados con músculos ventriculares sometidos a las reacciones NADH-TR, SDH y mATPasa. En base en estas reacciones se observó que el músculo está constituido por tres tipos de fibras musculares SO, FOG y FG, distribuidas en la forma de mosaico. La frecuencia de las fibras fue de 22,7%, 69,9% e 7,4%, respectivamente. La mayor frecuencia de fibras oxidativas SO+FOG caracterizó al músculo, con metabolismo aeróbico, resistente a la fatiga. El músculo ventricular fue considerado como rápido. El estudio de las uniones neuromusculares, después de la reacción de la esterasa inespecífica, evidenció que estas uniones son del tipo placa y de ocurrencia múltiple en el músculo ventricular

  8. Efectividad de la rehabilitación vestibular en una serie clínica Effectiveness of vestibular rehabilitation in a clinical series

    Directory of Open Access Journals (Sweden)

    Héctor Riveros

    2007-12-01

    Full Text Available Introducción: La rehabilitación vestibular (RV consiste en ejercicios que aceleran la compensación laberíntica, aumentando y/o mejorando la actividad de los otros dos sistemas que intervienen en el sistema del equilibrio. Objetivo: Evaluar la efectividad de un programa de RV en pacientes de nuestro servicio de Otorrinolaringología, con inestabilidad en la marcha secundaria a patología vestibular. Material y método: Estudio prospectivo de pacientes con desequilibrio objetivado mediante examen de VIII par. Se les aplicó una encuesta deRV valorada para determinar el grado de desequilibrio y la alteración de actividades de la vida diaria. Al grupo estudiado se aplicaron ejercicios de RV durante 6 semanas, y el grupo control recibió tratamiento farmacológico estándar. Resultados: Se reclutaron 48 pacientes; 26 en el grupo estudiado y 22 en el grupo control. En el grupo en estudio, a las 6 semanas todos presentaron algún grado de mejoría, encontrándose sólo desequilibrio leve en 92% y mejoría total en 8%. En el grupo control, a las 6 semanas la sintomatología persistió en 50% de los pacientes y el 50% restante presentó aún desequilibrio leve; ninguno se recuperó totalmente. Discusión: La RV es un programa de ejercicios de aplicación no invasiva, de fácil realización en el hogar, que ha demostrado ser efectiva en la disminución de la inestabilidad, con lo cual se recobran gran parte de las actividades del diario vivirIntroduction: Vestibular rehabilitation (VR consists of a series of exercises that increase labyrinthine compensation and/or improve the activity of the other two systems that participate in balance. Aim: To evaluate the effectiveness of a VR program in patients in our ORL department presenting with walking instability secondary to vestibular pathology. Material and method: Prospective study of patients with objective imbalance as demonstrated by VIII nerve test. Patients were asked to answer a questionnaire on VR in order to determine the degree of imbalance and the level of daily life disturbances. The study group was assigned to a VR exercise program for 6 weeks, while the control group received standard pharmacological treatment. Results: 48 patients were included, 26 in the study group and 22 in the control group. In the study group, after 6 weeks all patients showed some degree of symptoms improvement, with 92% reporting only mild imbalance, and with complete rehabilitation in 8%. In the control group, after 6 weeks symptoms persisted in 50% of patients, and the remaining 50% reported mild imbalance; none recovered completely. Discussion: VR is a non-invasive exercise program, easily performed at home, that has demonstrated to be effective in reducing imbalance, which in turns results in that many of the daily activities can be performed again

  9. Influence of gender on the vestibular evoked myogenic potential / Influência do gênero no potencial miogênico evocado vestibular

    Scientific Electronic Library Online (English)

    Aline Tenório Lins, Carnaúba; Vanessa Vieira, Farias; Nastassia, Santos; Aline Cabral de, Oliveira; Renato Glauco de Souza, Rodrigues; Pedro de Lemos, Menezes.

    2011-04-01

    Full Text Available Não existe consenso sobre a relevância dos fatores que influenciam as diferenças entre gêneros no comportamento dos músculos. Alguns estudos relatam existir uma relação entre tensão muscular e amplitude do potencial miogênico evocado vestibular, outros apenas que os resultados dependem dos músculos [...] estudados ou do aumento da carga imposta. OBJETIVOS: Este estudo tem como objetivo comparar os parâmetros do potencial miogênico evocado vestibular, entre os gêneros, em indivíduos jovens. MATERIAL E MÉTODO: Selecionaram-se 80 adultos jovens, sendo 40 homens e 40 mulheres. Foram promediados estímulos tone burts na frequência de 500Hz, na intensidade de 90 dBNA, utilizando-se um filtro passa banda de 10 a 1000 Hz, com amplificação de 10 a 25 microvolts por divisão. Os registros foram realizados em janelas de 80 ms. FORMA DE ESTUDO: experimental e prospectivo. RESULTADOS: Ao comparar os achados em função do gênero, não se constatou diferenças expressivas em relação à latência das ondas, p =0,19 e p =0,50, para as ondas P13 e N23, respectivamente, nem em relação ao valor de amplitude, p =0,28 p =0,40, para as ondas P13 e N23, respectivamente. CONCLUSÃO: Não houve diferença entre os gêneros quanto aos fatores latência e amplitude por haver um monitoramento da tensão do músculo esternocleidomastoideo durante o exame. Abstract in english There is no consensus on the relevance of factors that influence gender differences in the behavior of muscles. Some studies have reported a relationship between muscle tension and amplitude of the vestibular evoked myogenic potential; others, that results depend on which muscles are studied or on h [...] ow much load is applied. AIMS: This study aims to compare vestibular evoked myogenic potential parameters between genders in young individuals. METHODS: Eighty young adults were selected - 40 men and 40 women. Stimuli were averaged tone-bursts at 500 Hz, 90 dBHL intensity, and a 10-1000 Hz bandpass filter with amplification of 10-25 microvolts per division. The recordings were made in 80 ms windows. STUDY TYPE: An experimental and prospective study. RESULTS: No significant gender differences were found in wave latency - p = 0.19 and p = 0.50 for waves P13 and N23, respectively. No differences were found in amplitude values - p = 0.28 p = 0.40 for waves P13 and N23, respectively. CONCLUSION: There were no gender differences in latency and amplitude factors; the sternocleidomastoid muscle strain was monitored during the examination.

  10. 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.

  11. Role of creatine in sensitivity and function of the auditory and vestibular system

    Directory of Open Access Journals (Sweden)

    Vahid Moradi

    2015-02-01

    Full Text Available Background and Aim: Creatine plays an important role in the regulation of cellular energy in high energy demand organs such as the inner ear. It is also believed to play a protective role. This article reviewed the mechanisms and effects of creatine on the auditory and vestibular systems.Recent Findings: Creatine transporters and creatine kinase enzymes are involved in converting creatine to creatine phosphate. Phosphate is a fuel cell available in the cochlear and vestibular hair cells and the protective cells, striavascularis, peripheral and central neural pathways to the auditory cortex. It provides essential ATP for auditory and vestibular system performance. Creatine kinase prevents cochlear damage by regulating the metabolism of energy in marginal layers of the striavascularis and preventing free radical production in stressful situations. It also plays an important role in vestibular compensation. Creatine kinase dysfunction leads to an increase in the threshold of auditory brainstem potentials and a reduction in vestibular performance. The use of creatine improves vestibular evoked myogenic potentials and neurologic symptoms.Conclusion: Creatine and creatine kinase protein is essential for normal hearing and balance function and sensitivity. Creatine kinase deficiency impairs the functioning of these two systems; however, creatine consumption may boost the sensitivity of the vestibular system and neurological performance. Effects of the creatine consumption on the auditory system have not yet been examined.

  12. Subjective Visual Vertical in Various Vestibular Disorders by Using a Simple Bucket Test.

    Science.gov (United States)

    Chetana, Naik; Jayesh, Rane

    2015-06-01

    Subjective Visual Vertical (S.V.V.) assesses the ability to perceive verticality which depends on visual, vestibular and somatosensory inputs. The judgment of verticality is altered when there is otolith dysfunction. Objective of our study was to present a simple method to assess S.V.V. and to analyze S.V.V. changes in various vestibular disorders. 100 subjects presenting with vestibular disorders in period of 1 year 2 months were subjected to Neurotological history and examination. Patients with non-vestibular causes were excluded. S.V.V was tested with a simple innovative device-a specially designed bucket. The angle of deviation from vertical was noted in degrees. Normal deviation is 0 ± 2°. Out of 23 patients with vestibular neuritis 83 % showed abnormal S.V.V. Amongst 11 patients of Meniere's disease, 55 % and 42 patients of BPPV, 71 % had abnormal S.V.V. Amongst 24 patients with other causes 15 % showed abnormal S.V.V. S.V.V is a reliable screening tool in assessment of vestibular dysfunction along with other clinical tests. It has a prognostic value during recovery following vestibular damage. The modified 'Bucket' is a simple, easy to use and cost-effective device to do the S.V.V. in daily practice. PMID:26075175

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

    International Nuclear Information System (INIS)

    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 insulity in the brainstem compared to the insular cortex suggesting a functional de-coupling between cortical and subcortical activity during the vestibular response.

  14. Regeneration of lateral line and inner ear vestibular cells.

    Science.gov (United States)

    Jørgensen, J M

    1991-01-01

    Labelling experiments with [3H]thymidine demonstrate a continuous production of cells in the mechanoreceptive lateral line organs of the eel (Anguilla anguilla) and butterfly fish (Pantodon buchholzi) as well as in the electroreceptive ampullary organ of the transparent catfish (Kryptopterus bicirrhus). Shortly after [3H]thymidine injection many cells are labelled in the middle and basal parts of the sensory organ and after a few days' survival sensory cells are also labelled. The vestibular sensory organs of selected species of fishes, amphibians, reptiles and birds also show a continuous production of cells. In the budgerigar (Melopsittacus undulatus) labelled cells are found in the basal and middle layer of the sensory epithelium a few hours after injection with [3H]thymidine. A few days after the injection labelled cells are found in non-calyceal hair cells. After one month the calyceal cells are also labelled. Similar experiments with the bat Pipistrellus nathusii and with normal and gentamicin-treated mice (Mus musculus) show no labelled cells in the inner ear sensory epithelia. The lateral line organs and vestibular epithelia of non-mammalian vertebrates all contain a small number of dark cells with the characteristics of apoptotic cells. Macrophages and inclusions in some cells, thought to be remnants of apoptotic cells, are occasionally seen. Fixation at different osmolarities has little effect on the number of dark cells. It is suggested that the continually produced cells replace apoptotic dying cells. PMID:1752161

  15. Large Vestibular Schwannomas Presenting during Pregnancy: Management Strategies.

    Science.gov (United States)

    Shah, Kushal J; Chamoun, Roukoz B

    2014-06-01

    Objective?Large vestibular schwannomas rarely present in pregnant women. Diagnosis and management of these tumors during pregnancy present a therapeutic challenge. Methods?A 20-year-old primigravida woman at 26 weeks' gestation was transferred to our facility with gait imbalance, left facial weakness, left ear hearing loss, and recent nausea and vomiting. Magnetic resonance imaging revealed a large left cerebellopontine angle mass with extension into the left internal auditory canal and compression of the fourth ventricle resulting in mild hydrocephalus. The patient was admitted with a plan for early delivery at 32 weeks followed by tumor resection. One week later, the patient's headache and neurologic symptoms worsened due to increased hydrocephalus; a ventriculoperitoneal shunt was placed. The next day, an emergent cesarean delivery was performed due to worsening respiratory status. Four days later, a tracheostomy and percutaneous endoscopic gastrostomy tube were placed due to dysphagia. Eight days after the delivery, the mass was resected with a left retrosigmoid approach without complications. Immunohistochemistry confirmed vestibular cellular schwannoma on cranial nerve VIII showing unusually high mitotic activity. Results?The patient was discharged to inpatient rehabilitation on postoperative day 12 without new neurologic deficit. At 1?month, the patient was swallowing without aspiration. Her facial sensation had returned, her facial weakness remained stable, and her gait was significantly improved. Conclusion?If the patient is neurologically stable, the best option is to delay resection until after delivery. If resection is necessary during pregnancy, the optimal time is during the second trimester. PMID:25072015

  16. Early diagnosis of acoustic neuroma by the vestibular test

    International Nuclear Information System (INIS)

    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. (orig.)

  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. PMID:25567092

  18. Evidence of feline herpesvirus-1 DNA in the vestibular ganglion of domestic cats.

    Science.gov (United States)

    Parzefall, Birgit; Schmahl, Wolfgang; Fischer, Andrea; Blutke, Andreas; Truyen, Uwe; Matiasek, Kaspar

    2010-06-01

    In humans, herpes simplex virus type-1 has recently been detected in the vestibular ganglion (VG) and labyrinth (VL) and may be associated with vestibular signs. Feline herpesvirus-1 (FHV-1) is widespread amongst cat populations and affects many different tissues. The aim of this pilot study was to investigate the presence of FHV-1 DNA in the VG and VL of randomly selected domestic cats using PCR. FHV-1 DNA was detected in the VG of 14% of the cats. There was no detectable FHV-1 DNA in the VL of any cat. None of the infected cats had vestibular signs related to the VG infection. PMID:19394881

  19. 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.

  20. 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 vestibular test parameters were altered when we compared experimental and control groups. CONCLUSION: Comparison between groups shows significant differences in many aspects of the vestibular analysis and calls our attention towards a possible participation of zinc on the genesis of vestibular disorders.

  1. Motor Neuron Diseases

    Science.gov (United States)

    Motor Neuron Diseases Fact Sheet See a list of all NINDS Disorders Get Web page suited for printing Email ... can I get more information? What are motor neuron diseases? The motor neuron diseases (MNDs) are a ...

  2. Clinical classification and pathological findings of vestibular schwannoma requiring surgical therapy after stereotactic radiosurgery

    International Nuclear Information System (INIS)

    The present study investigated imaging, intraoperative and pathological findings, and surgical indications and timing in 10 patients [5 men, 5 women; mean age, 52.3 years (range, 17-70 years)] with vestibular schwannoma who underwent surgical therapy due to poor radiotherapy-mediated tumor control; these included Gamma Knife (n=8), X-Knife (n=1) and proton beam (n=1) therapies. The mean period from radiotherapy endpoint until surgery was 63.3 months (range, 30-96 months) and patients were classified according to the time elapsed between radiotherapy and surgical therapy [?2 to <5 years (n=4); ?5 to <8 years (n=4); or ?8 years (n=2)]. Surgical indications were classified into two groups: exacerbated or additional neurological symptoms caused by solid tumor component enlargement (n=2); and exacerbated or additional neurological symptoms with extraparenchymal extension of the tumor cyst (n=8). Imaging findings were classified as large cystic (LC; n=8), multi-micro cystic (MC; n=2), or solid component enlargement (SC; n=0) types. Pathological findings revealed no malignant changes in any patient, and primary pathological conditions comprised radiotherapy-induced exacerbation of vascular occlusion and permeability. MC patients presented marked hemosiderosis and recurrent small hemorrhage was predicted. Intraoperative findings included marked adhesions with peripheral neurons and the cerebellum, as well as arachnoid thickening, rendering complete resection difficult. ering complete resection difficult. Decompression surgery was relatively straightforward for LC, which presents little bleeding, but it was challenging for MC due to its hemorrhagic nature. SC cases have been previously reported, but were not found in the present study, which had an inclusion criterion of ?2 years follow-up after radiotherapy. Other than a single case that became malignant, all of the previously reported cases were within 2 years of radiotherapy and transient swelling may have been present. (author)

  3. Neuronal expression of Raf protooncogene in the brain stem of adult guinea pig.

    Science.gov (United States)

    Mihály, A; Endrész, V

    2000-05-01

    The Raf protooncogenes encode for cytoplasmic serine/threonine-specific protein kinases which can be activated via growth factor receptors by phosphorylation. Immunohistochemical and Western blotting studies have proven the existence of Raf protein kinases in neurons of the cerebral cortex of rats and guinea pigs. The aim of the present study was to map the immunohistochemical distribution of Raf kinase-like staining in the brain stem of guinea pig. Polyclonal antibodies were used that were raised against a recombinant viral protein in combination with the avidin-biotin-peroxidase system for detection of immunoreactivity. Specificity of the antibodies was tested in Western blotting experiments. Cytoplasmic immunostaining was observed in motor nuclei of hypoglossal, accessory, vagus, facial, trigeminal, abducent, oculomotor and trochlear nerves, and in the nucleus ambiguus, nucleus retroambigualis, lateral vestibular nucleus, mesencephalic nucleus of the trigeminal nerve, the red nucleus, raphe nuclei and reticular formation. Scattered neurons were stained in other sensory nuclei, such as solitary tract nuclei, medial, dorsal and ventral vestibular nuclei and cochlear nuclei. The spinal trigeminal nucleus and the main sensory nucleus of the trigeminal nerve contained few medium-sized immunoreactive cells. In general, staining was mainly somatodendritic; the axonal plexus was not positive. It is concluded, that the widespread neuronal appearance of cytoplasmic Raf kinase suggests an important role in transmission of trophic and growth factor signals in these neurons. PMID:10824613

  4. Configuração das pregas vestibulares à fonação em adultos com e sem disfonia Vestibular fold configuration during phonation in adults with and without dysphonia

    Directory of Open Access Journals (Sweden)

    Marcos Antônio Nemetz

    2005-02-01

    Full Text Available As pregas vestibulares participam da emissão vocal com mudanças evidentes de posição e forma durante este processo, porém pouco ou quase nada se conhece sobre o significado desta participação e como se iniciam estes movimentos ativos que mudam sua forma e contorno. Entendemos que o conhecimento da participação das pregas vestibulares na fisiologia laríngea possa ter importante aplicação prática, pois permitirá avaliar melhor o comprometimento funcional em condições patológicas, o que auxiliará na definição de estratégias para o adequado tratamento. OBJETIVO: Estudar a configuração da prega vestibular durante a fonação (emissão sustentada do /µ/ comparando exames de indivíduos sem queixa vocal (grupo eufonia com portadores de queixa de voz (grupo disfonia. FORMA DE ESTUDO: Coorte transversal simples. MATERIAL E MÉTODO: Foram analisados 120 registros de imagens de laringes, sendo 60 de indivíduos eufônicos e 60 de disfônicos, constituído cada grupo de igual número de indivíduos em relação ao gênero. Foi identificada a posição da borda livre de prega vestibular em relação a uma reta que une as inserções anterior e posterior da mesma. Na dependência desta posição, foram descritos três tipos de configurações: côncava, quando estava em posição lateral, convexa quando em posição medial e linear quando paralela ou se sobrepunha. RESULTADOS: Das 240 pregas vestibulares, 158 eram côncavas, 41 convexas e 31 lineares. A forma côncava predominou nos dois grupos em relação às outras, porém as formas convexa e linear aumentaram no grupo disfonia. No feminino, a forma linear teve aumento significante no grupo disfonia, enquanto no masculino o aumento significante ocorreu na forma convexa. CONCLUSÃO: Existe diferença no comportamento da prega vestibular no grupo disfonia em relação à eufonia, sendo que esta diferença ocorre de forma diversa em relação aos gêneros.The real participation of the vestibular folds during phonation mechanism is unknown. How vestibular folds change their configuration during phonation is still unclear. Learning about these changes in the functional mechanism of vestibular fold would be helpful for the evaluation of pathological conditions. AIM: The objective of the present study was to analyze the configuration of laryngeal vestibular folds during phonation (sustained emission of vowel /µ/ by comparing exams of individuals without vocal complaints (the normal voice group with those with vocal complaints. STUDY DESIGN: Transversal simple study. MATERIAL AND METHOD: 120 images of larynges were analyzed, 60 of normal voice individuals and 60 of dysphonic subjects, with equal gender distribution. The position of the free margin of the vestibular fold was identified in relation to a straight line that brought together the anterior and posterior insertions. Regarding this position, three types of configurations were described: concave, when it was in a lateral position, convex when it was in a medial position, and linear when it overlapped. RESULTS: Out of the 240 vestibular folds, 158 were concave, 41 convex and 31 linear. The concave form was predominant in both groups in relation to the other two forms, although the number of convex and linear forms increased in the dysphonic group. Analyzing the behavior of these forms in each gender we noticed that among women, the linear form was significantly increased in the dysphonic group, whereas among men there was significant increase in convex form. CONCLUSION: We concluded that there were differences in behavior of vestibular folds in the dysphonic group in relation to the normal voice group, and that the differences occurred differently in both gender groups.

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

    Directory of Open Access Journals (Sweden)

    Aline Cabral de Oliveira

    2008-10-01

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

  6. Subjective visual horizontal and stabilometer findings in patients with unilateral severe vestibular dysfunction.

    Science.gov (United States)

    Takai, Yoshinari; Iwasaki, Shinichi; Murofushi, Toshihisa

    2005-01-01

    The records of both stabilometer and subjective visual horizontal (SVH) testing can be used to evaluate vestibular compensation. When results of SVH testing have a strong significant correlation to those of stabilometer testing, clinicians can omit one of two tests from the test battery. To investigate the correlation, results of these two tests of patients with unilateral severe vestibular dysfunction were studied. Twenty-eight patients, 20 men and 8 women, with unilateral severe vestibular dysfunction were enrolled in this study. The correlation between these two tests was considered not significant according to the results. In conclusion, we cannot omit either stabilometer testing or SVH testing for the evaluation of patients with vestibular dysfunction. PMID:16327274

  7. Neck proprioception compensates for age-related deterioration of vestibular self-motion perception.

    Science.gov (United States)

    Schweigart, Georg; Chien, Rey-Djin; Mergner, Thomas

    2002-11-01

    Vestibular functions are known to show some deterioration with age. Vestibular deterioration is often thought to be compensated for by an increase in neck proprioceptive gain. We studied this presumed compensatory mechanism by measuring psychophysical responses to vestibular (horizontal canal), neck and combined stimuli in 50 healthy human subjects as a function of age (range 15-76 years). After passive horizontal rotations of head and/or trunk (torso) in complete darkness (dominant frequencies 0.05, 0.1, and 0.4 Hz), subjects readjusted a visual target to its remembered prerotational location in space. (1) Vestibular-only stimulus(whole-body rotation); subjects' responses were shifted towards postrotatory body position, this only slightly at 0.4 Hz and pronounced at 0.1 and 0.05 Hz. These errors reflect the known physiological drop of vestibular gain at low rotational frequency. They exhibited a slight but significant increase with age. (2) Neck-only stimulus(trunk rotated, head stationary); the responses showed errors similar to those upon vestibular stimulation (with offset towards postrotatory trunk position) and this again slightly more with increasing age. (3) Vestibular-neck stimulus combinationduring head rotation on stationary trunk; the errors were close to zero, independent of stimulus frequency and the subjects' age. (4) Opposite stimulus combination(trunk rotated in the same direction as the head, but with double amplitude); the errors were clearly enhanced, essentially reflecting the sum of those with vestibular-only and neck-only stimulation. Taken together, we find a parallel increase in neck- and vestibular-related errors with age, in seeming contrast to previous studies. We explain our and the previous findings by a vestibular-neck interaction model in which two different neck signals are involved. One neck signal is used, in combination with the vestibular signal, for estimating trunk-in-space rotation. It is internally shaped to always match the vestibular signal, so that these two signals cancel each other out when summed during head rotation on stationary trunk. Because of this matching, perceived trunk stationariness during head rotation on the stationary trunk is independent of vestibular deterioration (related to stimulus frequency, age, ototoxic medication, etc.). The other neck proprioceptive signal, coding head-on-trunk rotation, is superimposed on the estimate of trunk-in-space rotation, thereby yielding a notion of head-in-space. This neck signal remains essentially unchanged with vestibular deterioration. Generally, we hold that the transformation of the vestibular signal from the head down to the trunk proceeds further to include the hip and the legs as well as the haptically perceived body support surface; by this, subjects yield a notion of support kinematics in space. As a consequence, spatial orientation is impaired by chronic vestibular deterioration only to the extent that the body support is moving in space, while it is unimpaired (determined by proprioception alone) during body motion with respect to a stationary support. PMID:12373373

  8. 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.

  9. diferenciación neuronal

    Directory of Open Access Journals (Sweden)

    Gabriel Moreno Gonz\\u00E1lez

    2006-01-01

    Full Text Available El L-glutamato (Glu es el principal neurotransmisor excitador del Sistema Nervioso Central (SNC y ejerce su función por medio de receptores (GluRs que se clasifican en dos grandes superfamilias. La primera la forman canales iónicos activados por ligando o receptores de glutamato ionotrópicos (iGluRs permeables a Ca2+, Na+ y K+. Estos se han clasificado en tres familias con base en datos farmacológicos y electrofisiológicos: los receptores para el ?-amino-3-hidroxi-5-metil-4-isoxazol propionato (AMPA; los receptores para kainato (KA; y los receptores para N-metil-Daspartato (NMDA. A la segunda superfamilia pertenecen los GluRs acoplados a segundos mensajeros (inositol 3-fosfato, diacilglicerol y AMP cíclico, también llamados receptores metabotrópicos (mGluRs. La importancia del estudio de los GluRs en el SNC se centra en el papel que estos cumplen en diversas enfermedades neurodegenerativas, como la corea de Huntington, la enfermedad de Parkinson, la enfermedad de Alzheimer, la esclerosis lateral amiotrófica, los accidentes vasculares cerebrales, la epilepsia, la demencia por VIH, la enfermedad de Creutzfeld-Jacob y la hipoglicemia, así como en enfermedades psiquiátricas como la esquizofrenia, la depresión, los trastornos de ansiedad y la enfermedad por estrés postraumático. Además, el Glu, al actuar mediante diversos receptores, desempeña un papel fundamental en los procesos que involucran la diferenciación neuronal y el desarrollo del SNC. Se sabe que existe una expresión diferencial de la gran variedad de subunidades de iGluRs y mGluRs durante la diferenciación y el desarrollo del SNC, la cual depende tanto de su localización en el SNC como de la etapa del desarrollo neuronal. Durante la neurogénesis, se encuentran niveles altos de Glu en las áreas de desarrollo del SNC que, por activación de diferentes receptores, dan lugar a una señalización por segundos mensajeros, una variación en las concentraciones de calcio intracelular [Ca2+]iy la expresión de genes importantes en la regulación del ciclo celular; lo anterior promueve el crecimiento y la diferenciación celular, así como la sobrevida neuronal. Además, el Glu favorece el crecimiento del árbol presináptico y la ramificación dendrítica postsináptica, lo que a su vez promueve el establecimiento y el mantenimiento sinápticos. Esto, junto con la eliminación sináptica y el silenciamiento de receptores, es un mecanismo fundamental para establecer redes neuronales maduras. El Glu también es importante para la formación de sinapsis inhibitorias durante el desarrollo. La activación de GluRs promueve el crecimiento de las dendritas de las neuronas motoras. Se ha observado que los cambios bifásicos en la [Ca2+]i, en respuesta a Glu, se correlacionan con las fases facilitadoras e inhibidoras del crecimiento dendrítico. La evidencia acumulada indica que, dependiendo de su concentración extracelular y del tipo de receptor estimulado, el Glu puede favorecer o detener la migración neuronal, que es fundamental para el desarrollo del SNC. Aunque hasta el momento los receptores de tipo NMDA son los más estudiados en el desarrollo del SNC, en esta revisión se muestra la importancia de la gran variedad de GluRs, tanto ionotrópicos como metabotrópicos, en los procesos mencionados anteriormente y que, según su patrón de expresión diferencial durante el desarrollo, cumplen un papel importante en el proceso de formación de las diferentes regiones del SNC desde la embriogénesis hasta la vida adulta.

  10. Characterization of Vestibular Dysfunction in the Mouse Model for Usher Syndrome 1F

    OpenAIRE

    Alagramam, Kumar N.; Stahl, John S.; Jones, Sherri M.; Pawlowski, Karen S.; Wright, Charles G.

    2005-01-01

    The deaf-circling Ames waltzer (av) mouse harbors a mutation in the protocadherin 15 (Pcdh15) gene and is a model for inner ear defects associated with Usher syndrome type 1F. Earlier studies showed altered cochlear hair cell morphology in young av mice. In contrast, no structural abnormality consistent with significant vestibular dysfunction in young av mice was observed. Light and scanning electron microscopic studies showed that vestibular hair cells from presumptive null alleles Pcdh15av-...

  11. Malignant Transformation of Acoustic Neuroma/Vestibular Schwannoma 10 Years after Gamma Knife Stereotactic Radiosurgery

    OpenAIRE

    Demetriades, Andreas K; Saunders, Nicholas; Rose, Peter; Fisher, Cyril; Rowe, Jeremy; Tranter, Robert; Hardwidge, Carl

    2010-01-01

    Only a handful of cases of de-novo malignancies of the vestibulocochlear nerve have been reported. Even rarer is the malignant transformation of a previously histologically diagnosed benign vestibular schwannoma. We present the case of a young adult who had combined operative/Gamma knife treatment for a benign vestibular schwannoma, followed by further surgery 2 years later. He represented 10 years after original diagnosis with facial numbness and ataxia, MRI showing gross tumor recurrence. A...

  12. Vestibular function in the temporal and parietal cortex: distinct velocity and inertial processing pathways

    OpenAIRE

    Jocelyne Ventre-Dominey

    2014-01-01

    A number of behavioural and neuroimaging studies have reported converging data in favour of a cortical network for vestibular function, distributed between the temporo-parietal cortex and the prefrontal cortex in the primate. In this review, we focus on the role of the cerebral cortex in visuo-vestibular integration including the motion sensitive temporo-occipital areas i.e. the middle superior temporal area (MST) and the parietal cortex. Indeed these two neighbouring cortical regions, thou...

  13. Central Integration of Canal and Otolith Signals is Abnormal in Vestibular Migraine

    OpenAIRE

    King, Susan; Wang, Joanne; Priesol, Adrian J.; Lewis, Richard F.

    2014-01-01

    Vestibular migraine (VM), a common cause of vestibular symptoms within the general population, is a disabling and poorly understood form of dizziness. We sought to examine the underlying pathophysiology of VM with three studies, which involved the central synthesis of canal and otolith cues, and present preliminary results from each of these studies: (1) VM patients appear to have reduced motion perception thresholds when canal and otolith signals are modulated in a co-planar manner during ro...

  14. Noisy Galvanic Vestibular Stimulation Modulates the Amplitude of EEG Synchrony Patterns

    OpenAIRE

    Kim, Diana J.; Yogendrakumar, Vignan; Chiang, Joyce; Ty, Edna; Wang, Z. Jane; Mckeown, Martin J.

    2013-01-01

    Noisy galvanic vestibular stimulation has been associated with numerous cognitive and behavioural effects, such as enhancement of visual memory in healthy individuals, improvement of visual deficits in stroke patients, as well as possibly improvement of motor function in Parkinson’s disease; yet, the mechanism of action is unclear. Since Parkinson’s and other neuropsychiatric diseases are characterized by maladaptive dynamics of brain rhythms, we investigated whether noisy galvanic vestibular...

  15. Intratympanic gentamicin injections for Meniere disease: vestibular hair cell impairment and regeneration.

    Science.gov (United States)

    De Waele, C; Meguenni, R; Freyss, G; Zamith, F; Bellalimat, N; Vidal, P P; Tran Ba Huy, P

    2002-11-12

    The authors treated 22 patients with intratympanic gentamicin. Vestibular function was measured using caloric and head impulse tests and vestibular evoked myogenic potentials induced by high amplitude sounds and short duration galvanic currents. Roughly one-third of the patients, after initially losing their caloric responses and displaying refixation saccades to head impulse tests, recovered within 2 years of the lesion. Vertigo did not recur in patients in whom the galvanic response was abolished. PMID:12427902

  16. [Betahistine in the treatment of vestibular and coordination disturbances in multiple sclerosis].

    Science.gov (United States)

    Popova, N F; Chugunova, M A; Kunel'skaia, N L; Shagaev, A S; Bo?ko, A N; Gusev, E I

    2011-01-01

    We present the results of the efficacy trial of betahistine (Vestibo) based on the complex clinical/instrumental examination (stabilometric, vestibulometric) in 40 patients with multiple sclerosis of different severity of vestibular and coordination dysfunction. We demonstrated the clinical efficacy and safety of using this drug as one of the areas of symptomatic therapy in treatment vestibular and coordination disturbances in multiple sclerosis. PMID:21916160

  17. Absence of nystagmus during REM sleep in patients with vestibular neuritis

    OpenAIRE

    Eisensehr, I.; Noachtar, S.; Strupp, M.; V, L.; Brandt, T.; Buttner, U.

    2001-01-01

    Saccades, including fast phases of nystagmus, disappear during drowsiness and non-rapid eye movement (NREM) sleep, but are present during the alert state and REM sleep. The purpose of this study was to determine whether spontaneous nystagmus is present in patients with vestibular neuritis during REM sleep.? Eight patients with spontaneous nystagmus due to vestibular neuritis and eight control patients without any nystagmus underwent at least one night of polysomnography. ...

  18. Endolympathic hydrops in patients with vestibular schwannoma: visualization by non-contrast-enhanced 3D FLAIR

    International Nuclear Information System (INIS)

    Signal intensity of ipsilateral labyrinthine lymph fluid has been reported to increase in most cases with vestibular schwannoma (VS) on 3D fluid attenuated inversion recovery (FLAIR). The purpose of this study was twofold, (1) to evaluate if endolymphatic space can be recognized in the patients with VS on non-contrast-enhanced 3D-FLAIR images and (2) to know if the vertigo in the patients with VS correlates to vestibular endolymphatic hydrops. From the introduction of 32-channel head coil at 3 T in May 2008 to June 2010, 15 cases with unilateral VS were identified in the radiology report database. The two cases without a significant signal increase on 3D FLAIR were excluded. Resting 13 cases were retrospectively analyzed in regard to the recognition of endolymphatic hydrops in the cochlea and vestibule and to the correlation between the patients' symptoms and endolymphatic hydrops. In all cases, vestibular endolymphatic space can be recognized on non-contrast-enhanced 3D FLAIR. Cochlear endolymphatic space can be identified only in one case with significant hydrops. Vestibular hydrops was identified in four cases. Among these four cases, three had vertigo, and one had no vertigo. In those nine cases without hydrops, two had vertigo, and seven did not have vertigo. No significant correlation between vertigo and vestibular hydrops was found. Vestibular endolymphatic space can be recognized on non-contrast-enhanced 3D FLAIR. In some patients with VS, vestibular hydrops iome patients with VS, vestibular hydrops is seen; however, endolymphatic hydrops in the vestibule might not be the only responsible cause of vertigo in the patients with VS. (orig.)

  19. MORPHO-PHYSIOLOGICAL STUDY OF HYPOTHALAMIC PARAVENTRICULAR AND SUPRAOPTIC NUCLEI PROJECTIONS TO SUPERIOR VESTIBULAR NUCLEUS IN NORM AND IN CONDITIONS OF UNILATERAL LABYRINTHECTOMY

    Directory of Open Access Journals (Sweden)

    J.S. Sarkissian

    2010-03-01

    Full Text Available We performed recording of spike activity of neurons of superior vestibular nucleus (SVN evoked on bilateral stimulation (100 Hz, 1 sec of paraventricular (PVN and supraoptic (SON nuclei of hypothalamus in norm and 17 days after unilateral labyrinthectomy (UL. Analysis and recording of impulse activity was performed by means of online software based on several histograms: perievent time, cumulative, frequency and those of averaged ones. Tetanic (TP, posttetanic (PTP potentiation and posttetanic depression (PTD were recorded in norm. PVN and SON stimulation resulted mainly in TP. Following the UL, reactions on stimulation of the same nuclei on intact side were characterized by diversity and dynamics with predominance of TP. On deafferented side, there were prevalence of PTD, tenuity of components and of reproducibility of poststimulus manifestations. The histochemical method of detection Ca2+-dependent acid phosphatase activity after UL revealed neurofibrillar changes, central chromatolysis, up to the absence of reaction in some sections.

  20. L-citrulline immunostaining identifies nitric oxide production sites within neurons

    Science.gov (United States)

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

    2002-01-01

    The cellular and subcellular localization of L-citrulline was analyzed in the adult rat brain and compared with that of traditional markers for the presence of nitric oxide synthase. Light, transmission electron, and confocal laser scanning microscopy were used to study tissue sections processed for immunocytochemistry employing a monoclonal antibody against L-citrulline or polyclonal anti-neuronal nitric oxide synthase sera, and double immunofluorescence to detect neuronal nitric oxide synthase and L-citrulline co-localization. The results demonstrate that the same CNS regions and cell types are labeled by neuronal nitric oxide synthase polyclonal antisera and L-citrulline monoclonal antibodies, using both immunocytochemistry and immunofluorescence. Short-term pretreatment with a nitric oxide synthase inhibitor reduces L-citrulline immunostaining, but does not affect neuronal nitric oxide synthase immunoreactivity. In the vestibular brainstem, double immunofluorescence studies show that many, but not all, neuronal nitric oxide synthase-positive cells co-express L-citrulline, and that local intracellular patches of intense L-citrulline accumulation are present in some neurons. Conversely, all L-citrulline-labeled neurons co-express neuronal nitric oxide synthase. Cells expressing neuronal nitric oxide synthase alone are interpreted as neurons with the potential to produce nitric oxide under other stimulus conditions, and the subcellular foci of enhanced L-citrulline staining are viewed as intracellular sites of nitric oxide production. This interpretation is supported by ultrastructural observations of subcellular foci with enhanced L-citrulline and/or neuronal nitric oxide synthase staining that are located primarily at postsynaptic densities and portions of the endoplasmic reticulum. We conclude that nitric oxide is produced and released at focal sites within neurons that are identifiable using L-citrulline as a marker. Copyright 2002 IBRO.

  1. Vestibular models for design and evaluation of flight simulator motion

    Science.gov (United States)

    Bussolari, S. R.; Sullivan, R. B.; Young, L. R.

    1986-01-01

    The use of spatial orientation models in the design and evaluation of control systems for motion-base flight simulators is investigated experimentally. The development of a high-fidelity motion drive controller using an optimal control approach based on human vestibular models is described. The formulation and implementation of the optimal washout system are discussed. The effectiveness of the motion washout system was evaluated by studying the response of six motion washout systems to the NASA/AMES Vertical Motion Simulator for a single dash-quick-stop maneuver. The effects of the motion washout system on pilot performance and simulator acceptability are examined. The data reveal that human spatial orientation models are useful for the design and evaluation of flight simulator motion fidelity.

  2. What can posturography tell us about vestibular function?

    Science.gov (United States)

    Black, F. O.

    2001-01-01

    Patients with balance disorders want answers to the following basic questions: (1) What is causing my problem? and (2) What can be done about my problem? Information to fully answer these questions must include status of both sensory and motor components of the balance control systems. Computerized dynamic posturography (CDP) provides quantitative assessment of both sensory and motor components of postural control along with how the sensory inputs to the brain interact. This paper reviews the scientific basis and clinical applications of CDP. Specifically, studies describing the integration of vestibular inputs with other sensory systems for postural control are briefly summarized. Clinical applications, including assessment, rehabilitation, and management are presented. Effects of aging on postural control along with prevention and management strategies are discussed.

  3. Optimal estimator models for spatial orientation and vestibular nystagmus.

    Science.gov (United States)

    Young, Laurence R

    2011-05-01

    Mathematical models have played an important role in research on the vestibular system over the past century, from the torsion pendulum analogies of the semicircular canal to the optimal estimator "observer" models of multisensory interaction and adaptation. This short review is limited to our own contributions in bringing the technology of feedback control theory to bear on the understanding of human spatial orientation, eye movements, and nystagmus, both on Earth and in space. It points to the importance of the "internal model" concept for treatment of the manner in which the brain constantly makes predictions about future sensory feedback, adjusts the weightings of sensors according to their signal-to-noise ratios, and adapts control according to the motion environment, and availability of sensory cues. PMID:21416377

  4. Betahistine dihydrochloride in the treatment of peripheral vestibular vertigo.

    Science.gov (United States)

    Mira, Eugenio; Guidetti, G; Ghilardi, L; Fattori, B; Malannino, N; Maiolino, L; Mora, R; Ottoboni, S; Pagnini, P; Leprini, M; Pallestrini, E; Passali, D; Nuti, D; Russolo, M; Tirelli, G; Simoncelli, C; Brizi, S; Vicini, C; Frasconi, P

    2003-02-01

    The present study compares the efficacy and safety of betahistine dihydrochloride to that of a placebo in recurrent vertigo resulting from Meniere's disease (MD) or in paroxysmal positional vertigo (PPV) of probable vascular origin. The design was double-blind, multicentre and parallel-group randomised. Eleven Italian centres enrolled 144 patients: 75 of the patients were treated with betahistine (41 MD/34 PPV) and 69 with placebos (40 MD/29 PPV). The betahistine dosage was 16 mg twice per day for 3 months. Compared to the placebo, betahistine had a significant effect on the frequency, intensity and duration of vertigo attacks. Associated symptoms and the quality of life also were significantly improved by betahistine. Both the physician's judgement and the patient's opinion on the efficacy and acceptability of the treatment were in agreement as to the superiority of betahistine. The effective and safe profile of betahistine in the treatment of vertigo due to peripheral vestibular disorders was confirmed. PMID:12582782

  5. Nonspecific vertigo with normal otoneurological examination. The role of vestibular laboratory tests.

    Science.gov (United States)

    Gordon, C R; Shupak, A; Spitzer, O; Doweck, I; Melamed, Y

    1996-12-01

    Vestibular laboratory tests are not generally necessary in the diagnosis of patients with a clear description of vertigo accompanied by positive otoneurological examination findings. The purpose of the study was to investigate the role of conventional vestibular laboratory tests in the diagnosis of patients complaining of nonspecific vertigo, despite their having a documented normal otoneurological examination. The results of the standard electronystagmography (ENG) and sinusoidal harmonic acceleration (SHA) tests of 52 patients referred for ambulatory vestibular laboratory tests due to a nonspecific illusion of movement, but with a normal otoneurological examination, were reviewed. Abnormalities were found in the vestibular tests of 35 patients (67 per cent), 22 of whom (63 per cent) were finally diagnosed as having a unilateral peripheral vestibular lesion, and 13 (37 per cent) benign positional vertigo. These results suggest that a high percentage of patients with nonspecific vertigo and a normal otoneurological examination probably suffer from peripheral vestibular dysfunction, which can be objectively documented by the ENG and SHA tests. PMID:9015425

  6. Fractionated Stereotactic Radiotherapy of Vestibular Schwannomas Accelerates Hearing Loss

    International Nuclear Information System (INIS)

    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 ithe 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.

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

    OpenAIRE

    FRIDMAN, GENE Y.; Davidovics, Natan S.; Dai, Chenkai; Migliaccio, Americo A; DELLA SANTINA, CHARLES C.

    2010-01-01

    There is no effective treatment available for individuals unable to compensate for bilateral profound loss of vestibular sensation, which causes chronic disequilibrium and blurs vision by disrupting vestibulo-ocular reflexes that normally stabilize the eyes during head movement. Previous work suggests that a multichannel vestibular prosthesis can emulate normal semicircular canals by electrically stimulating vestibular nerve branches to encode head movements detected by mutually orthogonal gy...

  8. Directional Plasticity Rapidly Improves 3D Vestibulo-Ocular Reflex Alignment in Monkeys Using a Multichannel Vestibular Prosthesis

    OpenAIRE

    Dai, Chenkai; FRIDMAN, GENE Y.; Chiang, Bryce; Rahman, Mehdi A.; Ahn, Joong Ho; Davidovics, Natan S.; DELLA SANTINA, CHARLES C.

    2013-01-01

    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...

  9. Restoring the 3D Vestibulo-Ocular Reflex via Electrical Stimulation: The Johns Hopkins Multichannel Vestibular Prosthesis Project

    OpenAIRE

    Rahman, Mehdi A.; Dai, Chenkai; FRIDMAN, GENE Y.; Davidovics, Natan S.; Chiang, Bryce; Ahn, JoongHo; Hayden, Russell; Melvin, Thuy-Anh N.; Sun, Daniel Q.; Hedjoudje, Abderrahmane; Santina, Charles C Della

    2011-01-01

    Bilateral loss of vestibular sensation causes difficulty maintaining stable vision, posture and gait. An implantable prosthesis that partly restores normal activity on branches of the vestibular nerve should improve quality of life for individuals disabled by this disorder. We have developed a head-mounted multichannel vestibular prosthesis that restores sufficient semicircular canal function to partially recreate a normal 3-dimensional angular vestibulo-ocular reflex in animals. Here we desc...

  10. Betahistine in the treatment of tinnitus in patients with vestibular disorders Betaistina no tratamento do zumbido em pacientes com distúrbios vestibulares

    Directory of Open Access Journals (Sweden)

    Maurício Malavasi Ganança

    2011-08-01

    Full Text Available Betahistine is a medicine used to treat vestibular disorders that has also been used to treat tinnitus. AIM: To assess the effects of betahistine on tinnitus in patients with vestibular disorders. MATERIAL AND METHOD: Retrospective data were collected from patient records for individuals presenting with vestibular dysfunction and tinnitus. Patients included had received betahistine 48 mg/day and clinical outcomes were compared with a control group comprising individuals who were unable to receive betahistine due to gastritis, ulcers, pregnancy, asthma or hypersensitivity to the drug. Patients underwent control of any aggravating factors and also standard vestibular exercises as a basis for treatment. The intensity, frequency and duration of tinnitus were assessed on the first day of dosing and after 120 days of treatment. Clinical improvement was defined as a total or partial reduction of tinnitus after treatment. RESULTS: Clinical improvement was observed in 80/262 (30. 5% of patients treated with betahistine and 43/252 (17. 1% of control patients. Betahistine significantly (pA betaistina é um medicamento utilizado no tratamento de distúrbios da função vestibular, que também tem sido utilizado para tratar o zumbido. OBJETIVO: Avaliar o efeito da betaistina sobre o zumbido de pacientes com distúrbios vestibulares. MATERIAL E MÉTODO: Foram coletados dados retrospectivos de pacientes com vestibulopatia e zumbido. Os pacientes incluídos receberam 48 mg/dia de betaistina ao dia e os resultados clínicos foram comparados com os de um grupo controle, que incluiu indivíduos impossibilitados de receber betaistina devido à gastrite, úlceras, gravidez, asma ou hipersensibilidade ao medicamento. Os pacientes realizaram controle de fatores agravantes e exercícios de reabilitação vestibular, como tratamento de base para a vestibulopatia. A intensidade, frequência e duração do zumbido foram avaliadas no primeiro dia e após 120 dias de tratamento. A melhora clínica foi definida pela redução total ou parcial do zumbido após o tratamento. RESULTADOS: Observou-se melhora clínica do zumbido em 80/262 (30,5% dos pacientes tratados com a betaistina e em 43/252 (17,1% pacientes do grupo controle. A betaistina melhorou significativamente (p<0.0001 o zumbido nos indivíduos tratados. CONCLUSÃO: A dose de 48 mg/dia de betaistina durante 120 dias consecutivos é útil na redução ou eliminação do zumbido de pacientes com distúrbios vestibulares

  11. Proposta de um protocolo para reabilitação vestibular em vestibulopatias periféricas / Protocol's proposal for vestibular rehabilitation in outlying vestibulopatia

    Scientific Electronic Library Online (English)

    Adriana Roberta Degressi, Rogatto; Laira, Pedroso; Sara Regina Meira, Almeida; Telma Dagmar, Oberg.

    2010-03-01

    Full Text Available INTRODUÇÃO: A reabilitação vestibular tem sido reconhecida como tratamento de escolha para pacientes com persistência da vertigem, por causa da disfunção vestibular periférica, proporcionando acentuada melhora na qualidade de vida. Dentre os tratamentos indicados, tem-se os exercícios de Cawthorne e [...] Cooksey, integração sensorial e plataformas com movimentação corpórea. OBJETIVO: O objetivo da pesquisa foi criar um protocolo de exercícios em um balanço, associando os exercícios de Cawthorne e Cooksey à Integração Sensorial. METODOLOGIA: Foi desenvolvido um relato de caso para avaliar uma paciente por meio das seguintes escalas: Escala de Equilíbrio de Berg e Dynamic Gait Índex (DGI) para verificar o equilíbrio; Five Times Sit-to-Stand (FTSTS) para avaliar a atividade de sentar e levantar; Dizziness Handicap Inventory (DHI) para verificar sintomas de vertigem; Escala de Sintomas após Tratamento Fisioterapêutico (ESATF), que gradua a sintomatologia após exercícios. Foi desenvolvido um protocolo associando as duas técnicas, nas quais os exercícios oculares, cefálicos e de tronco eram associados ao balanço. Foram realizadas 10 das 20 sessões previstas, por causa da frequência irregular do paciente às sessões. RESULTADOS: O paciente melhorou de 19 para 22 pontos na DGI, manteve a pontuação na Berg e melhorou de 74 para 67 pontos na DHI. Na escala FTSTS, diminuiu o tempo de 15 para 14 segundos para realizar atividade de sentar e levantar. Na ESATF, houve oscilação da pontuação. CONCLUSÕES: Após o tratamento, a paciente manteve e obteve melhora no equilíbrio e na capacidade funcional e diminuiu o tempo gasto para realizar a atividade de sentar e levantar cinco vezes de uma cadeira com os membros superiores cruzados. Estudos adicionais com o protocolo proposto devem ser realizados, com um número maior de pacientes e maior assiduidade para haver habituação e reabilitação mais precoce. Abstract in english INTRODUCTION: Vestibular rehabilitation has been recognized as a treatment of choice for patients with persistent vertigo due to peripheral vestibular dysfunction, providing significant improvements in quality of life. Among the treatments listed have been exercises Cawthorne and Cooksey, sensory in [...] tegration and body-moving platforms. OBJECTIVE: The research objective was to invent the protocol of exercises in balance with the exercises of Cawthorne and Cooksey associated to the Sensory Integrative. METHOD: It was developed a pilot case, where was evaluated in the patient the balance for the Scale of Balance of Berg and Dynamic Gait Index (DGI); Five Times Sit-to-Stand (FTSTS), that evaluate the activity to sit down and to get up; Dizziness Handicap Inventory (DHI) that evaluate symptoms of vertigo; Scale of Symptoms after Physiotherapeutic Treatment (ESATF), graduates the symptoms after exercises. It was developed a protocol associating 2 techniques, which the ocular exercises, cephalic and of trunk were associated to the swinging. 10 of 20 sessions were accomplished, due to the patient's little regular attendance. RESULTS: Patient obtained improvement from 19 to 22 in DGI; maintained the points of the Berg; she improved from 74 to 67 in DHI. In scale FTSTS she decreased the time from 15 to 14 seconds to accomplish activities of to sit down and to get up. In ESATF it happened oscillate in punctuation. CONCLUSION: After the treatment, the patient obtained an improvement in the appraised balance and improvement of the functional capacity, and she reduced the time spend to accomplish the activity of to sit down and to get up five times of a chair with the crossed arms. Additional studies with the proposed protocol should be accomplished, with a larger number of patients and regular attendance to have a faster adaptation.

  12. Perfil audiológico de idosos submetidos à reabilitação vestibular / Audiologic profile of older adults subjected to vestibular rehabilitation therapy

    Scientific Electronic Library Online (English)

    Sara Alois de Abreu, Martins; Iara, Bassi; Patrícia Cotta, Mancini.

    2015-06-01

    Full Text Available OBJETIVO: caracterizar o perfil auditivo de idosos com tontura submetidos à Reabilitação Vestibular e comparar os resultados obtidos nas avaliações auditivas de idosos sem tontura. MÉTODOS: estudo observacional analítico transversal com 87 idosos, sendo 35 no grupo com tontura e 52 no grupo sem ton [...] tura. Foram realizadas anamnese, audiometria tonal limiar e vocal. Para a análise estatística foi utilizado o programa estatístico Statistical Package for the Social Sciences versão 17.0, com nível de significância de 5% nas análises. RESULTADOS: a perda auditiva neurossensorial de grau leve e moderada esteve presente em 72,4% da amostra, com piora dos limiares de audibilidade por via aérea a partir de 4000Hz em ambos os grupos. O zumbido foi a queixa mais frequente observada na amostra. CONCLUSÃO: o perfil auditivo de idosos com tontura não se diferencia daquele encontrado em idosos sem tontura, sendo observada com maior frequência a perda auditiva neurossensorial leve bilateral de configuração descendente. Abstract in english PURPOSE: to characterize the auditory profile of older adults with dizziness undergoing vestibular rehabilitation therapy and to compare the results with the profile of older adults without dizziness. METHODS: a cross-sectional, observational, and analytical study conducted with 87 older adults, 35 [...] in the group with dizziness and 52 in the group without dizziness. The participants were interviewed and subjected to pure-tone threshold audiometry and speech audiometry. Statistical analysis was performed using the software Statistical Package for the Social Sciences version 17.0, at 5% significance. RESULTS: approximately 72.4% of the sample exhibited mild sensorineural hearing loss, with the air conduction threshold of audibility beginning to be affected at 4,000 Hz in both groups. Tinnitus was the complaint most frequently reported by the participants. CONCLUSION: the auditory profile of older adults with dizziness did not differ from the profile exhibited by older adults without dizziness; bilateral mild sensorineural hearing loss with a downward sloping configuration was the most frequent finding.

  13. Sintomas vestibulares em crianças com queixa de dificuldades escolares Vestibular symptoms in children with complaints of school difficulties

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    Eloisa Sartori Franco

    2008-01-01

    Full Text Available OBJETIVO: Estudar os sintomas vestibulares em crianças com queixas de dificuldades escolares. MÉTODOS: Foram estudadas 88 crianças entre sete e 12 anos, que freqüentavam escolas públicas da cidade de Piracicaba no período de 2004 a 2006. Os procedimentos utilizados foram: a anamnese; exame otorrinolaringológico; exame audiológico e questionário dirigido utilizado como instrumento de coleta de dados. RESULTADOS: Das crianças avaliadas 51% não relataram dificuldades escolares e 49% referiram ter dificuldades escolares. A queixa referida mais comum foi a de vertigem (22,7%, e os sintomas referidos mais comuns no ambiente escolar foram de ansiedade (95,5% e cefaléia (53,4%, as dificuldades escolares mais citadas foram a de ler (56,8% e a de copiar (43,2%. CONCLUSÕES: A queixa de tontura e as dificuldades em ler e copiar apresentaram relação estatisticamente significante nas crianças com queixas de dificuldades escolares.PURPOSE: To study vestibular symptoms in children with complaints of school difficulties. METHODS: Eighty-eight children between seven and 12 years old were studied. The subjects attended public schools from Piracicaba - SP (Brazil during the period from 2004 to 2006. The procedures included: anamnesis, otorhinolaryngological examination, audiological examination, and a directed questionnaire used as an instrument for data gathering. RESULTS: From the evaluated children, 51% had no complaints of school difficulties, and 49% reported school difficulties. The most common complaint reported was vertigo (22.7%, and the most common symptoms reported in school environment were anxiety (95.5% and chronic headache (53.4%. The most cited school difficulties were reading (56.8% and copying (43.2%. CONCLUSIONS: Vertigo complaints and reading and copying difficulties presented a statistically significant relation in children with complaints of school difficulties.

  14. Sintomas vestibulares em crianças com queixa de dificuldades escolares / Vestibular symptoms in children with complaints of school difficulties

    Scientific Electronic Library Online (English)

    Eloisa Sartori, Franco; Ivone, Panhoca.

    Full Text Available OBJETIVO: Estudar os sintomas vestibulares em crianças com queixas de dificuldades escolares. MÉTODOS: Foram estudadas 88 crianças entre sete e 12 anos, que freqüentavam escolas públicas da cidade de Piracicaba no período de 2004 a 2006. Os procedimentos utilizados foram: a anamnese; exame otorrinol [...] aringológico; exame audiológico e questionário dirigido utilizado como instrumento de coleta de dados. RESULTADOS: Das crianças avaliadas 51% não relataram dificuldades escolares e 49% referiram ter dificuldades escolares. A queixa referida mais comum foi a de vertigem (22,7%), e os sintomas referidos mais comuns no ambiente escolar foram de ansiedade (95,5%) e cefaléia (53,4%), as dificuldades escolares mais citadas foram a de ler (56,8%) e a de copiar (43,2%). CONCLUSÕES: A queixa de tontura e as dificuldades em ler e copiar apresentaram relação estatisticamente significante nas crianças com queixas de dificuldades escolares. Abstract in english PURPOSE: To study vestibular symptoms in children with complaints of school difficulties. METHODS: Eighty-eight children between seven and 12 years old were studied. The subjects attended public schools from Piracicaba - SP (Brazil) during the period from 2004 to 2006. The procedures included: anamn [...] esis, otorhinolaryngological examination, audiological examination, and a directed questionnaire used as an instrument for data gathering. RESULTS: From the evaluated children, 51% had no complaints of school difficulties, and 49% reported school difficulties. The most common complaint reported was vertigo (22.7%), and the most common symptoms reported in school environment were anxiety (95.5%) and chronic headache (53.4%). The most cited school difficulties were reading (56.8%) and copying (43.2%). CONCLUSIONS: Vertigo complaints and reading and copying difficulties presented a statistically significant relation in children with complaints of school difficulties.

  15. Optimal visual-vestibular integration under conditions of conflicting intersensory motion profiles.

    Science.gov (United States)

    Butler, John S; Campos, Jennifer L; Bülthoff, Heinrich H

    2015-02-01

    Passive movement through an environment is typically perceived by integrating information from different sensory signals, including visual and vestibular information. A wealth of previous research in the field of multisensory integration has shown that if different sensory signals are spatially or temporally discrepant, they may not combine in a statistically optimal fashion; however, this has not been well explored for visual-vestibular integration. Self-motion perception involves the integration of various movement parameters including displacement, velocity, acceleration and higher derivatives such as jerk. It is often assumed that the vestibular system is optimized for the processing of acceleration and higher derivatives, while the visual system is specialized to process position and velocity. In order to determine the interactions between different spatiotemporal properties for self-motion perception, in Experiment 1, we first asked whether the velocity profile of a visual trajectory affects discrimination performance in a heading task. Participants performed a two-interval forced choice heading task while stationary. They were asked to make heading discriminations while the visual stimulus moved at a constant velocity (C-Vis) or with a raised cosine velocity (R-Vis) motion profile. Experiment 2 was designed to assess how the visual and vestibular velocity profiles combined during the same heading task. In this case, participants were seated on a Stewart motion platform and motion information was presented via visual information alone, vestibular information alone or both cues combined. The combined condition consisted of congruent blocks (R-Vis/R-Vest) in which both visual and vestibular cues consisted of a raised cosine velocity profile and incongruent blocks (C-Vis/R-Vest) in which the visual motion profile consisted of a constant velocity motion, while the vestibular motion consisted of a raised cosine velocity profile. Results from both Experiments 1 and 2 demonstrated that visual heading estimates are indeed affected by the velocity profile of the movement trajectory, with lower thresholds observed for the R-Vis compared to the C-Vis. In Exp. 2 when visual-vestibular inputs were both present, they were combined in a statistically optimal fashion irrespective of the type of visual velocity profile, thus demonstrating robust integration of visual and vestibular cues. The study suggests that while the time course of the velocity did affect visual heading judgments, a moderate conflict between visual and vestibular motion profiles does not cause a breakdown in optimal integration for heading. PMID:25361642

  16. Circling behavior developed in Dmp1 null mice is due to bone defects in the vestibular apparatus

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    Kun Lv, Haiyang Huang, Yongbo Lu, Chunlin Qin, Zubing Li, Jian Q. Feng

    2010-01-01

    Full Text Available With age, there is a progressive loss of body balance function. Yet, the potential influence of osteoporosis on body balance is largely unknown. Dentin matrix protein 1 (DMP1 is highly expressed in bone and required for phosphate homeostasis and mineralization. Dmp1 null mice display striking defects in bone structure. In this study we reported circling behavior and hyper reaction to touching in Dmp1 null mice. Our histology, tartrate resistant acid phosphatase (TRAP staining and µCT data showed dramatic changes, such as an expansion of poorly mineralized matrices, in the Dmp1 null porous bony structure in the vestibular apparatus. The targeted re-expression of DMP1 in the Dmp1 null bone fully rescued not only the bone phenotype, but also circling behavior and hyper reaction. Furthermore, X-gal stain and DMP1 immunohistochemistry assay showed that DMP1 was not expressed in neuron cells or balance related cells in the inner ear, suggesting that a defect in the bony labyrinth of the internal ear is indirectly responsible for the circling behavior and/or hyper reaction to touching. Finally, discovery of DMP1 lacZ signal in pericyte-like cells may suggest a new function of DMP1 in angiogenesis.

  17. Endolympathic hydrops in patients with vestibular schwannoma: visualization by non-contrast-enhanced 3D FLAIR

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    Naganawa, Shinji; Kawai, Hisashi [Nagoya University Graduate School of Medicine, Department of Radiology, Nagoya (Japan); Sone, Michihiko; Nakashima, Tsutomu [Nagoya University Graduate School of Medicine, Department of Otorhinolaryngology, Nagoya (Japan); Ikeda, Mitsuru [Nagoya University School of Health Sciences, Department of Radiological Technology, Nagoya (Japan)

    2011-12-15

    Signal intensity of ipsilateral labyrinthine lymph fluid has been reported to increase in most cases with vestibular schwannoma (VS) on 3D fluid attenuated inversion recovery (FLAIR). The purpose of this study was twofold, (1) to evaluate if endolymphatic space can be recognized in the patients with VS on non-contrast-enhanced 3D-FLAIR images and (2) to know if the vertigo in the patients with VS correlates to vestibular endolymphatic hydrops. From the introduction of 32-channel head coil at 3 T in May 2008 to June 2010, 15 cases with unilateral VS were identified in the radiology report database. The two cases without a significant signal increase on 3D FLAIR were excluded. Resting 13 cases were retrospectively analyzed in regard to the recognition of endolymphatic hydrops in the cochlea and vestibule and to the correlation between the patients' symptoms and endolymphatic hydrops. In all cases, vestibular endolymphatic space can be recognized on non-contrast-enhanced 3D FLAIR. Cochlear endolymphatic space can be identified only in one case with significant hydrops. Vestibular hydrops was identified in four cases. Among these four cases, three had vertigo, and one had no vertigo. In those nine cases without hydrops, two had vertigo, and seven did not have vertigo. No significant correlation between vertigo and vestibular hydrops was found. Vestibular endolymphatic space can be recognized on non-contrast-enhanced 3D FLAIR. In some patients with VS, vestibular hydrops is seen; however, endolymphatic hydrops in the vestibule might not be the only responsible cause of vertigo in the patients with VS. (orig.)

  18. Reading at vestibular: the primacy of understanding legitimated at the portuguese language test A leitura no vestibular: a primazia da compreensão legitimada na prova de Língua Portuguesa

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    Angela Cristina Calciolari

    2002-11-01

    Full Text Available This work starts from the presupposition that reading questions in vestibular (College admission exams do not verify the actual reading of the candidate, but show the reading understanding of their creator. The reading evaluation questions of the Portuguese Language test in the Concurso Vestibular de Inverno 2001/UEM (Maringá State University winter admission exam, 2001 are analyzed, verifying the phases of the reading process: de-codification, understanding and interpretation. The analysis shows a predominance of understanding questions, with lesser incidence of de-codification and interpretation questions.A partir do pressuposto de que as questões de leitura em concursos vestibulares não verificam a real leitura do aluno-candidato, mas expõem a compreensão leitora do seu elaborador, este artigo analisa as questões que avaliam a leitura na prova de Língua Portuguesa, do Concurso Vestibular de Inverno 2001/UEM, verificando as etapas do processo de leitura: decodificação, compreensão e interpretação. As análises demonstram a predominância de questões de compreensão, com menor incidência em questões referentes à decodificação e à interpretação.

  19. Betahistine in the treatment of tinnitus in patients with vestibular disorders / Betaistina no tratamento do zumbido em pacientes com distúrbios vestibulares

    Scientific Electronic Library Online (English)

    Maurício Malavasi, Ganança; Heloisa Helena, Caovilla; Juliana Maria, Gazzola; Cristina Freitas, Ganança; Fernando Freitas, Ganança.

    2011-08-01

    Full Text Available A betaistina é um medicamento utilizado no tratamento de distúrbios da função vestibular, que também tem sido utilizado para tratar o zumbido. OBJETIVO: Avaliar o efeito da betaistina sobre o zumbido de pacientes com distúrbios vestibulares. MATERIAL E MÉTODO: Foram coletados dados retrospectivos de [...] pacientes com vestibulopatia e zumbido. Os pacientes incluídos receberam 48 mg/dia de betaistina ao dia e os resultados clínicos foram comparados com os de um grupo controle, que incluiu indivíduos impossibilitados de receber betaistina devido à gastrite, úlceras, gravidez, asma ou hipersensibilidade ao medicamento. Os pacientes realizaram controle de fatores agravantes e exercícios de reabilitação vestibular, como tratamento de base para a vestibulopatia. A intensidade, frequência e duração do zumbido foram avaliadas no primeiro dia e após 120 dias de tratamento. A melhora clínica foi definida pela redução total ou parcial do zumbido após o tratamento. RESULTADOS: Observou-se melhora clínica do zumbido em 80/262 (30,5%) dos pacientes tratados com a betaistina e em 43/252 (17,1%) pacientes do grupo controle. A betaistina melhorou significativamente (p Abstract in english Betahistine is a medicine used to treat vestibular disorders that has also been used to treat tinnitus. AIM: To assess the effects of betahistine on tinnitus in patients with vestibular disorders. MATERIAL AND METHOD: Retrospective data were collected from patient records for individuals presenting [...] with vestibular dysfunction and tinnitus. Patients included had received betahistine 48 mg/day and clinical outcomes were compared with a control group comprising individuals who were unable to receive betahistine due to gastritis, ulcers, pregnancy, asthma or hypersensitivity to the drug. Patients underwent control of any aggravating factors and also standard vestibular exercises as a basis for treatment. The intensity, frequency and duration of tinnitus were assessed on the first day of dosing and after 120 days of treatment. Clinical improvement was defined as a total or partial reduction of tinnitus after treatment. RESULTS: Clinical improvement was observed in 80/262 (30. 5%) of patients treated with betahistine and 43/252 (17. 1%) of control patients. Betahistine significantly (p

  20. Building the Neuron

    Science.gov (United States)

    Robotics Engineering for Better Life and Sustainable Future RET,

    What does the brain look like? As engineers, how can we look at neural networks without invasive surgery? In this activity, students design and build neuron models based on observations made while viewing neurons through a microscope. The models are used to explain how each structure of the neuron contributes to the overall function. Students share their models with younger students and explain what a neuron is, its function, and how engineers use their understanding of the neuron to make devices to activate neurons.

  1. 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 term of gravity during space flight, and because of the plasticity of the brain, it might be possible that their inputs be progressively interpreted as resulting from translational move-ment with no gravity related activation. Therefore, on return to Earth the effect of the otoliths on cardiovascular regulation might be temporarily lost leading to orthostatic intolerance.

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

    Science.gov (United States)

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

    2014-11-01

    Vestibular neuritis (VN) is a sudden peripheral unilateral vestibular failure with often persistent head movement-related dizziness and unsteadiness. Compensation of asymmetrical activity in the primary peripheral vestibular afferents is accomplished by restoration of impaired brainstem vestibulo-ocular and vestibulo-spinal reflexes, but presumably also by changing cortical vestibular tone imbalance subserving, e.g., spatial perception and orientation. The aim of this study was to elucidate (i) whether there are changes of cerebral resting-state networks with respect to functional interregional connectivity (resting-state activity) in VN patients and (ii) whether these are related to neurophysiological, perceptual and functional parameters of vestibular-induced disability. Using independent component analysis (ICA), we compared resting-state networks between 20 patients with unilateral VN and 20 age- and gender-matched healthy control subjects. Patients were examined in the acute VN stage and after 3 months. A neural network (component 50) comprising the parietal lobe, medial aspect of the superior parietal lobule, posterior cingulate cortex, middle frontal gyrus, middle temporal gyrus, parahippocampal gyrus, anterior cingulate cortex, insular cortex, caudate nucleus, thalamus and midbrain was modulated between acute VN patients and healthy controls and in patients over time. Within this network, acute VN patients showed decreased resting-state activity (ICA) in the contralateral intraparietal sulcus (IPS), in close vicinity to the supramarginal gyrus (SMG), which increased after 3 months. Resting-state activity in IPS tended to increase over 3 months in VN patients who improved with respect to functional parameters of vestibular-induced disability (VADL). Resting-state activity in the IPS was not related to perceptual (subjective visual vertical) or neurophysiological parameters of vestibular-induced disability (e.g., gain of vestibulo-ocular reflex, caloric responsiveness, postural sway). VN leads to a change in resting-state activity of the contralateral IPS adjacent to the SMG, which reverses during vestibular compensation over 3 months. The ventral intraparietal area in the IPS contains multimodal regions with directionally selective responses to vestibular stimuli making them suitable for participating in spatial orientation and multisensory integration. The clinical importance is indicated by the fact that the increase in resting-state activity tended to be larger in those patients with only little disability at the follow-up examination. This may indicate powerful restitution-related or compensatory cortical changes in resting-state activity. PMID:23881293

  3. Plasticity of the histamine H3 receptors after acute vestibular lesion in the adult cat

    Science.gov (United States)

    Tighilet, Brahim; Mourre, Christiane; Lacour, Michel

    2014-01-01

    After unilateral vestibular neurectomy (UVN) many molecular and neurochemical mechanisms underlie the neurophysiological reorganizations occurring in the vestibular nuclei (VN) complex, as well as the behavioral recovery process. As a key regulator, the histaminergic system appears to be a likely candidate because drugs interfering with histamine (HA) neurotransmission facilitate behavioral recovery after vestibular lesion. This study aimed at analyzing the post-lesion changes of the histaminergic system by quantifying binding to histamine H3 receptors (H3R; mediating namely histamine autoinhibition) using a histamine H3 receptor agonist ([3H]N-?-methylhistamine). Experiments were done in brain sections of control cats (N = 6) and cats submitted to UVN and killed 1 (N = 6) or 3 (N = 6) weeks after the lesion. UVN induced a bilateral decrease in binding density of the agonist [3H]N-?-methylhistamine to H3R in the tuberomammillary nuclei (TMN) at 1 week post-lesion, with a predominant down-regulation in the ipsilateral TMN. The bilateral decrease remained at the 3 weeks survival time and became symmetric. Concerning brainstem structures, binding density in the VN, the prepositus hypoglossi, the subdivisions of the inferior olive decreased unilaterally on the ipsilateral side at 1 week and bilaterally 3 weeks after UVN. Similar changes were observed in the subdivisions of the solitary nucleus only 1 week after the lesion. These findings indicate vestibular lesion induces plasticity of the histamine H3R, which could contribute to vestibular function recovery. PMID:24427120

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

    Science.gov (United States)

    Lowery, Mary Sue

    1998-01-01

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

  5. 7-Tesla MRI demonstrates absence of structural lesions in patients with vestibular paroxysmia

    Science.gov (United States)

    Rommer, Paulus S.; Wiest, Gerald; Kronnerwetter, Claudia; Zach, Heidemarie; Loader, Benjamin; Elwischger, Kirsten; Trattnig, Siegfried

    2015-01-01

    Vestibular parxoysmia (VP) is a rare vestibular disorder. A neurovascular cross-compression (NVCC) between the vestibulochochlear nerve and an artery seems to be responsible for short attacks of vertigo in this entity. An NVCC can be seen in up to every fourth subject. The significance of these findings is not clear, as not all subjects suffer from symptoms. The aim of the present study was to assess possible structural lesions of the vestibulocochlear nerve by means of high field magnetic resonance imaging (MRI), and whether high field MRI may help to differentiate symptomatic from asymptomatic subjects. 7 Tesla MRI was performed in six patients with VP and confirmed NVCC seen on 1.5 and 3.0 MRI. No structural abnormalities were detected in any of the patients in 7 Tesla MRI. These findings imply that high field MRI does not help to differentiate between symptomatic and asymptomatic NVCC and that the symptoms of VP are not caused by structural nerve lesions. This supports the hypothesis that the nystagmus associated with VP has to be conceived pathophysiologically as an excitatory vestibular phenomenon, being not related to vestibular hypofunction. 7 Tesla MRI outperforms conventional MRI in image resolution and may be useful in vestibular disorders. PMID:26106306

  6. Expression of estrogen and progesterone receptors in vestibular schwannomas and their clinical significance

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    Pandey Rakesh

    2009-11-01

    Full Text Available Abstract Objective The objective was to determine the expression of estrogen and progesterone receptors in vestibular schwannomas as well as to determine predictive factors for estrogen and progesterone receptor positivity. Materials and methods The study included 100 cases of vestibular schwannomas operated from January 2006 to June 2009. The clinical details were noted from the medical case files. Formaldehyde-fixed parafiin-embedded archival vestibular schwannomas specimens were used for the immunohistochemical assessment of estrogen and progesterone receptors. Results Neither estrogen nor progesterone receptors could be detected in any of our cases by means of well known immunohistochemical method using well documented monoclonal antibodies. In the control specimens, a strongly positive reaction could be seen. Conclusion No estrogen and progesterone receptor could be found in any of our 100 cases of vestibular schwannomas. Hence our study does not support a causative role of estrogen and progesterone in the growth of vestibular schwannoma as well as hormonal manipulation in the treatment of this tumor.

  7. Reabilitação Vestibular em portadores de Vertigem Posicional Paroxística Benigna Vestibular rehabilitation in patients with benign paroxysmal positional vertigo

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    João Simão de Melo Neto

    2012-01-01

    Full Text Available OBJETIVO: verificar, por meio do questionário handicap de tontura, o efeito de um protocolo de Reabilitação Vestibular (RV em portadores de Vertigem Posicional Paroxística Benigna (VPPB sete dias após primeira intervenção e seis meses após a segunda intervenção. MÉTODO: pacientes submetidos à confirmação diagnóstica de VPPB pela positividade da manobra Dix-Hallpike foram avaliados (coleta pelo questionário Dizziness Handicap Inventory - brasileiro (DHI-brasileiro, antes da primeira intervenção, após a segunda (intervalo de sete dias e seis meses após a segunda intervenção. As intervenções constavam de relaxamento cervical, manobra de Epley e restrições posturais e foram aplicadas logo após a primeira avaliação e antes da segunda avaliação, com intervalo de sete dias. Os resultados obtidos foram submetidos à análise estatística. RESULTADOS: nove mulheres com média de 63 anos (desvio padrão 4,6 fizeram parte da amostra. Foram encontradas as seguintes pontuações no DHI-brasileiro: Aspecto Físico - apresentou média na coleta 1 de 2,6a(±0,17; coleta 2 de 0,82b (±0,24; coleta 3 de 1,43b(±0,43 com pPURPOSE: to evaluate, by means of the dizziness handicap questionnaire, the effect of a Vestibular Rehabilitation (VR protocol in patients with benign paroxysmal positional vertigo (BPPV, seven days after the first intervention and six months after the second intervention. METHOD: patients undergoing BPPV diagnosis confirmation by a positive Dix-Hallpike maneuver were assessed (collection by the Dizziness Handicap Inventory - Brazilian (DHI-Brazilian before the first intervention, after the second (seven day interval and six months after the second one. The interventions consisted of cervical relaxation, Epley and postural restrictions were applied after the first assessment and before the second evaluation, with an interval of seven days. The results were statistically analyzed. RESULTS: nine women with an average 63-year old (standard deviation 4.6. Were found in DHI-Brazilian aspects: Physical - the collection 1 a mean of 2.6a(±0.17; collection 2 of 0.82b(±0.24; collection 3 of 1.43b(±0.43 with p<0.05; Functional - the collection 1 a mean of 1.73(±0 21; collection 2 of 0.93(±0.27; collection 3 of 1.28(±0.39; Emotional - the collection 1 a mean of 1.03(±0.24; collection 2 of 0.49(±0.23; collection 3 of 0.82(±0.36. CONCLUSION: the BPPV, when evaluated by the DHI-Brazilian, harms the patients in some aspects and vestibular rehabilitation, with the application of the proposed protocol, it promoted improved quality of life, with greater reduction in symptoms, seven days after the first intervention. After six months there was some reduction in the status of improvements, but it still remained in better condition comparing with the first collection.

  8. 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

    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 schwannoma risk in men (relative risk estimate = 0.87, 95% confidence interval: 0.52, 1.46), and no vestibular schwannoma cases among long-term subscribers occurred in women versus 1.6 expected. Vestibular schwannomas did not occur more often on the right side of the head, although the majority of Danes reported holding their mobile phone to the right ear. Vestibular schwannomas in long-term male subscribers were not oflarger size than expected. Overall, no evidence was found that mobile phone use is related to the risk of vestibular schwannoma. Because of the usually slow growth of vestibular schwannoma and possible diagnostic delay, further surveillance is indicated.

  9. Two radical neuron doctrines

    OpenAIRE

    Hilbert, David R.; Byrne, Alex

    1999-01-01

    Two radical neuron doctrines must be distinguished--strong and weak. G&S direct much of their attack at the former--but the Churchlands only hold the latter. The weak radical neuron doctrine remains a serious possibility.

  10. Connect the Neurons

    Science.gov (United States)

    Dr. Janet M Dubinsky (University of Minnesota Neuroscience)

    2008-10-28

    Students draw on gloves to represent dendrites and axons then model the chemical communication between pre-synaptic and post-synaptic neurons by transferring cotton-ball neurotransmitters from glove-to-glove between themselves, human neurons.

  11. What are Neurons?

    Science.gov (United States)

    Nancy P. Moreno

    2003-01-01

    This neuroscience activity introduces learners to how messages are sent and received by neurons. Learners use modeling clay and pipe cleaners to build model neurons. This lesson guide includes background information, extension ideas, and handout.

  12. Reabilitação Vestibular em portadores de Vertigem Posicional Paroxística Benigna / Vestibular rehabilitation in patients with benign paroxysmal positional vertigo

    Scientific Electronic Library Online (English)

    João Simão de, Melo Neto; Ana Elisa Zuliani, Stroppa; Carlos Arantes, Parrera; Wilson Franscisco, Maximiano; Cláudia Augusta, Hidalgo.

    2013-06-01

    Full Text Available OBJETIVO: verificar, por meio do questionário handicap de tontura, o efeito de um protocolo de Reabilitação Vestibular (RV) em portadores de Vertigem Posicional Paroxística Benigna (VPPB) sete dias após primeira intervenção e seis meses após a segunda intervenção. MÉTODO: pacientes submetidos à conf [...] irmação diagnóstica de VPPB pela positividade da manobra Dix-Hallpike foram avaliados (coleta) pelo questionário Dizziness Handicap Inventory - brasileiro (DHI-brasileiro), antes da primeira intervenção, após a segunda (intervalo de sete dias) e seis meses após a segunda intervenção. As intervenções constavam de relaxamento cervical, manobra de Epley e restrições posturais e foram aplicadas logo após a primeira avaliação e antes da segunda avaliação, com intervalo de sete dias. Os resultados obtidos foram submetidos à análise estatística. RESULTADOS: nove mulheres com média de 63 anos (desvio padrão 4,6) fizeram parte da amostra. Foram encontradas as seguintes pontuações no DHI-brasileiro: Aspecto Físico - apresentou média na coleta 1 de 2,6a(±0,17); coleta 2 de 0,82b (±0,24); coleta 3 de 1,43b(±0,43) com p Abstract in english PURPOSE: to evaluate, by means of the dizziness handicap questionnaire, the effect of a Vestibular Rehabilitation (VR) protocol in patients with benign paroxysmal positional vertigo (BPPV), seven days after the first intervention and six months after the second intervention. METHOD: patients undergo [...] ing BPPV diagnosis confirmation by a positive Dix-Hallpike maneuver were assessed (collection) by the Dizziness Handicap Inventory - Brazilian (DHI-Brazilian) before the first intervention, after the second (seven day interval) and six months after the second one. The interventions consisted of cervical relaxation, Epley and postural restrictions were applied after the first assessment and before the second evaluation, with an interval of seven days. The results were statistically analyzed. RESULTS: nine women with an average 63-year old (standard deviation 4.6). Were found in DHI-Brazilian aspects: Physical - the collection 1 a mean of 2.6a(±0.17); collection 2 of 0.82b(±0.24); collection 3 of 1.43b(±0.43) with p

  13. Schwannoma vestibular: 825 casos - 25 anos de experiência / Vestibular schwannoma: 825 cases from a 25-year experience

    Scientific Electronic Library Online (English)

    Ricardo Ferreira, Bento; Mariana Hausen, Pinna; Rubens Vuono de, Brito Neto.

    2012-12-01

    Full Text Available INTRODUÇÃO: Os tumores do nervo acústico foram reconhecidos como uma entidade clínico-patológica há pelo menos 200 anos, representando cerca de 90% das afecções do ângulo ponto cerebelar. Histologicamente derivam da bainha de Schwann, sendo constituído por células alongadas, em paliçada nos pequenos [...] tumores. Nos grandes tumores, além do encontrado nos pequenos, temos uma degeneração cística nas áreas centrais, possivelmente por deficiência de vascularização. Estudamos retrospectivamente oitocentos e vinte e cinco (825) pacientes com diagnóstico de schwanoma vestibular submetidos à cirurgia para exérese do tumor no período de janeiro de 1984 a agosto de 2006. OBJETIVO: Avaliar sinais, sintomas e aspectos do diagnóstico clínico, audiológico, de imagem, as técnicas cirúrgicas utilizadas e suas complicação peri e pós cirúrgicas. MÉTODO: Série de casos, retrospectivo por análise prontuário de todos os pacientes submetidos a este tipo de cirurgia no período. RESULTADO E CONCLUSÃO: Hipoacusia é o primeiro sintoma da presença da doença em quase a totalidade dos casos, o tamanho do tumor não é proporcional ao comprometimento do limiar auditivo, as técnicas empregadas foram seguras quanto à preservação da função facial, a via retrolabiríntica demonstrou ser de utilidade nos tumores pequenos com 50% de preservação de audição. Abstract in english INTRODUCTION: Acoustic nerve tumors have been recognized as a clinico-pathologic entity for at least 200 years, and they represent 90% of cerebellopontine angle diseases. Histologically, the tumors are derived from Schwann cells of the myelin sheath, with smaller tumors consisting of elongated palis [...] ade cells, while in large tumors, cystic degeneration can be found in the central areas, possibly due to deficient vascularization. We retrospectively reviewed 825 cases of vestibular schwannomas, reported between January 1984 and August 2006, in which the patients underwent surgery to remove the tumor. OBJECTIVE: To evaluate signs, symptoms, aspects of clinical diagnosis, including the results of audiological and imaging studies, and surgical techniques and complications. METHODS: A retrospective chart review. The medical records of all patients undergoing surgical treatment for schwannoma during the period indicated were reviewed. RESULTS AND CONCLUSION: Hearing loss was the first symptom reported in almost all cases, and tumor size was not proportional to the impairment of the auditory threshold. The surgical techniques allowed safe preservation of facial function. In particular, the retrolabyrinthine route proved useful in small tumors, with 50% preservation of hearing.

  14. Vestibular schwannoma: 825 cases from a 25-year experience

    Directory of Open Access Journals (Sweden)

    Bento, Ricardo Ferreira

    2012-01-01

    Full Text Available Introduction: Acoustic nerve tumors have been recognized as a clinico-pathologic entity for at least 200 years, and they represent 90% of cerebellopontine angle diseases. Histologically, the tumors are derived from Schwann cells of the myelin sheath, with smaller tumors consisting of elongated palisade cells, while in large tumors, cystic degeneration can be found in the central areas, possibly due to deficient vascularization. We retrospectively reviewed 825 cases of vestibular schwannomas, reported between January 1984 and August 2006, in which the patients underwent surgery to remove the tumor. Objective: To evaluate signs, symptoms, aspects of clinical diagnosis, including the results of audiological and imaging studies, and surgical techniques and complications. Methods: A retrospective chart review. The medical records of all patients undergoing surgical treatment for schwannoma during the period indicated were reviewed. Results and Conclusion: Hearing loss was the first symptom reported in almost all cases, and tumor size was not proportional to the impairment of the auditory threshold. The surgical techniques allowed safe preservation of facial function. In particular, the retrolabyrinthine route proved useful in small tumors, with 50% preservation of hearing.

  15. Increasing annual incidence of vestibular schwannoma and age at diagnosis

    DEFF Research Database (Denmark)

    Stangerup, Sven-Eric; Tos, Mirko

    2004-01-01

    During the last 26 years the annual number of diagnosed vestibular schwannomas (VS) has been increasing. The aim of this study is to describe and analyse this increase. Since 1976, 1446 new cases of VS have been diagnosed at the authors' centre. Special focus was on the age at diagnosis, the localization and the size of the tumour. The size of the tumour was registered as either intrameatal or with the largest extrameatal diameter. The annual number of diagnosed VS has increased from 26 in 1976 to 101 in 2001. The size of the diagnosed tumours has decreased from a median of 35 mm in 1979 to 10 mm in 2001. In the first years large and giant tumours dominated, in contrast to recent years in which intrameatal and small tumours dominated. The median age at the time of diagnosis has been almost unchanged through the period (median 55 years). If the decreasing size of the tumour and the increasing incidence of VS can be explained only by earlier diagnosis and easier access to magnetic resonance (MR) scanning it should be expected that the median age at the time of diagnosis would decrease simultaneously. In this study, the median age at the time of diagnosis has been almost unchanged throughout the 26-year period. This paradox can be explained by the fact that, with easier access to MR scanning, the examination has been offered also to elderly patients, in whom the small and intrameatal tumours dominate.

  16. Morphology of the Vestibular Utricule in Toadfish, Opsanus Tau

    Science.gov (United States)

    Bass, L.; Smith, J.; Twombly, A.; Boyle, Richard; Varelas, Ehsanian J.; Johanson, C.

    2003-01-01

    The uticle is an otolith organ in the vertebrate inner ear that provides gravitoinertial acceleration information into the vestibular reflex pathways. The aim of the present study was to provide an anatomical description of this structure in the adult oyster toadfish, and establish a morphological basis for interpretation of subsequent functional studies. Light, scanning electron and transmission electron microscopy were applied to visualize the sensory epithelium and its neural innervation. Electrophysiological techniques were used to identify utricular afferents by their response to translation stimuli. Similar to nerve afferents supplying the semicircular canals and lagena, utricular afferents commonly exhibit a short-latency increase of firing rate in response to electrical activation of the central efferent pathway. Afferents were labeled with biocytin either intraaxonally or with extracellular bulk deposits. Light microscope images of serial thick sections were used to make three-dimensional reconstructions of individual labeled afferents to identify the dendritic morphology with respect to epithelial location. Scanning electron microscopy was used to visualize the surface of the otolith mass facing the otolith membrane, and the hair cell polarization patterns of strioler and extrastriolar regions. Transmission electron micrographs of serial thin sections were compiled to create a three-dimensional reconstruction of the labeled afferent over a segment of its dendritic field and to examine the hair cell-afferent synaptic contacts.

  17. Functional testing of the vestibular ocular reflex (VOR

    Directory of Open Access Journals (Sweden)

    StefanoRamat

    2012-03-01

    Full Text Available The experimental assessment of the vestibulo-ocular-reflex (VOR gain provides an objective and quantitative measure of VOR performance which is nonetheless difficult to correlate with its efficiency in everyday living conditions. We developed the Head Impulse Testing Device (HITD based on an inertial sensing system allowing to investigate the functional performance of the VOR by testing its gaze stabilization ability in response to head impulses at different head angular accelerations. HITD results on a population of 39 vestibular patients were compared to those of 22 controls. Overall the sensitivity of the HITD was 92% against the results of the clinical head impulse test and 83% against the clinical diagnosis, while the specificity was 58% against the clinical head impulse test and 83% against the diagnosis. The HITD appears to be a very promising tool for detecting abnormal VOR performance while providing information on the functional performance of the rotational VOR. As compared to the usual testing devices the HITD tests higher frequencies and accelerations that characterize head movements in everyday life activities and provides a functional assessment that is more likely to be related to the subject’s self-feeling.

  18. Betahistine reduces the resting firing rate of vestibular receptors in the frog.

    Science.gov (United States)

    Valli, P

    2000-01-01

    Although betahistine is widely used in the treatment of vertigo, it remains unclear whether it directly affects the vestibular system at the peripheral level. The effects of betahistine were therefore assessed in an isolated preparation of frog semicircular canal. Betahistine was administered either in the endolymphatic or the perilymphatic fluid and the ampullar receptor potential and mass nerve discharge were recorded at rest and during mechanical stimulation. Endolymphatic administration was without effect. In contrast, perilymphatic administration resulted in a marked reduction in ampullar receptor resting discharge, although the mechanically evoked responses were only slightly affected. As vertigo is generally caused by sudden and uncontrolled changes in the resting discharge of vestibular receptors, the ability of betahistine to reduce the resting firing rate of vestibular receptors is thought to contribute to its anti-vertigo actions. PMID:10904794

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

    Directory of Open Access Journals (Sweden)

    McCall Andrew A

    2009-06-01

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

  20. Application of multivariate statistics to vestibular testing: discriminating between Meniere's disease and migraine associated dizziness

    Science.gov (United States)

    Dimitri, P. S.; Wall, C. 3rd; Oas, J. G.; Rauch, S. D.

    2001-01-01

    Meniere's disease (MD) and migraine associated dizziness (MAD) are two disorders that can have similar symptomatologies, but differ vastly in treatment. Vestibular testing is sometimes used to help differentiate between these disorders, but the inefficiency of a human interpreter analyzing a multitude of variables independently decreases its utility. Our hypothesis was that we could objectively discriminate between patients with MD and those with MAD using select variables from the vestibular test battery. Sinusoidal harmonic acceleration test variables were reduced to three vestibulo-ocular reflex physiologic parameters: gain, time constant, and asymmetry. A combination of these parameters plus a measurement of reduced vestibular response from caloric testing allowed us to achieve a joint classification rate of 91%, independent quadratic classification algorithm. Data from posturography were not useful for this type of differentiation. Overall, our classification function can be used as an unbiased assistant to discriminate between MD and MAD and gave us insight into the pathophysiologic differences between the two disorders.

  1. Prevalência de sintomas auditivos e vestibulares em trabalhadores expostos a ruído ocupacional Prevalencia de síntomas auditivos y vestibulares en trabajadores expuestos al ruido ocupacional Prevalence of auditory and vestibular symptoms among workers exposed to occupational noise

    OpenAIRE

    Rosalina Ogido; Everardo Andrade da Costa; Helymar da Costa Machado

    2009-01-01

    O objetivo do estudo foi estimar a prevalência de sintomas auditivos e vestibulares em trabalhadores expostos a ruído ocupacional. Foram analisados os prontuários de 175 trabalhadores com perda auditiva induzida por ruído, atendidos em um centro de referência de saúde ocupacional de Campinas, SP, de 1997 a 2003. As variáveis estudadas foram freqüência dos sintomas de hipoacusia, zumbido e vertigem. As associações com idade, tempo de exposição ao ruído e limiares auditivos tonais foram analisa...

  2. Functional MRI of galvanic vestibular stimulation with alternating currents at different frequencies.

    Science.gov (United States)

    Stephan, Thomas; Deutschländer, Angela; Nolte, Annina; Schneider, Erich; Wiesmann, Martin; Brandt, Thomas; Dieterich, Marianne

    2005-07-01

    Functional MRI was performed in 28 healthy volunteers to study the effects of galvanic vestibular stimulation with alternating currents (AC-GVS) of different frequencies on brain activation patterns. The aims of this study were (1) to identify specific areas within the vestibular cortical network that are involved in the processing of frequency-specific aspects by correlation analyses, (2) to determine the optimal frequency for stimulation of the vestibular system with respect to perception, and (3) to analyze whether different frequencies of AC-GVS are mediated in different cortical areas or different sites within the vestibular cortex. AC-GVS was performed using sinusoidal stimulation currents with an amplitude of +/-2.5 mA, and frequencies of 0.1 Hz, 0.3 Hz, 0.8 Hz, 1.0 Hz, 2.0 Hz, and 5.0 Hz were applied. Regardless of the applied stimulation frequency, AC-GVS elicited activations within a network of multisensory areas similar to those described in earlier studies using direct currents. No mapping of different stimulation frequencies to different cortical locations was observed. Additional activations of somatosensory cortex areas were observed during stimulation with 5 Hz only. The strongest vestibular sensations were reported during stimulation with 1 Hz and 2 Hz. Correlation analyses between blood oxygenation level dependent (BOLD) signal changes and stimulation frequency revealed a positive dependency in areas of the supramarginal gyrus, posterolateral thalamus, cerebellar vermis, posterior insula, and in the hippocampal region/uncus. These regions represent areas involved in the processing of vestibular information for head and body orientation in space. PMID:15955481

  3. Noisy galvanic vestibular stimulation modulates the amplitude of EEG synchrony patterns.

    Science.gov (United States)

    Kim, Diana J; Yogendrakumar, Vignan; Chiang, Joyce; Ty, Edna; Wang, Z Jane; McKeown, Martin J

    2013-01-01

    Noisy galvanic vestibular stimulation has been associated with numerous cognitive and behavioural effects, such as enhancement of visual memory in healthy individuals, improvement of visual deficits in stroke patients, as well as possibly improvement of motor function in Parkinson's disease; yet, the mechanism of action is unclear. Since Parkinson's and other neuropsychiatric diseases are characterized by maladaptive dynamics of brain rhythms, we investigated whether noisy galvanic vestibular stimulation was associated with measurable changes in EEG oscillatory rhythms within theta (4-7.5 Hz), low alpha (8-10 Hz), high alpha (10.5-12 Hz), beta (13-30 Hz) and gamma (31-50 Hz) bands. We recorded the EEG while simultaneously delivering noisy bilateral, bipolar stimulation at varying intensities of imperceptible currents - at 10, 26, 42, 58, 74 and 90% of sensory threshold - to ten neurologically healthy subjects. Using standard spectral analysis, we investigated the transient aftereffects of noisy stimulation on rhythms. Subsequently, using robust artifact rejection techniques and the Least Absolute Shrinkage Selection Operator regression and cross-validation, we assessed the combinations of channels and power spectral features within each EEG frequency band that were linearly related with stimulus intensity. We show that noisy galvanic vestibular stimulation predominantly leads to a mild suppression of gamma power in lateral regions immediately after stimulation, followed by delayed increase in beta and gamma power in frontal regions approximately 20-25 s after stimulation ceased. Ongoing changes in the power of each oscillatory band throughout frontal, central/parietal, occipital and bilateral electrodes predicted the intensity of galvanic vestibular stimulation in a stimulus-dependent manner, demonstrating linear effects of stimulation on brain rhythms. We propose that modulation of neural oscillations is a potential mechanism for the previously-described cognitive and motor effects of vestibular stimulation, and noisy galvanic vestibular stimulation may provide an additional non-invasive means for neuromodulation of functional brain networks. PMID:23874865

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

    Science.gov (United States)

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

    2010-01-01

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

  5. Influência da reabilitação vestibular na qualidade de vida de indivíduos labirintopatas / Influence of vestibular rehabilitation on the quality of life of individuals with labyrinth disease

    Scientific Electronic Library Online (English)

    Shirley Nogueira, Soares; Maria Adriana da Silva, Gonçalves; Claudiana Gomes, Teixeira; Priscila Caetano, Romualdo; Juliana Nunes, Santos.

    2014-06-01

    Full Text Available Objetivo verificar a influência da reabilitação vestibular sobre a qualidade de vida dos indivíduos por meio do questionário Dizziness Handicap Inventory aplicado pré e pós-terapia. Métodos: foram analisados 28 prontuários de indivíduos de ambos os sexos atendidos em uma Clínica Escola do municípi [...] o de Belo Horizonte. Os pacientes responderam ao questionário pré e pós terapia de reabilitação vestibular personalizada (RVP). A análise estatística dos dados foi feita por meio do teste T-Student pareado. Resultados a amostra do estudo foi composta por 28 pacientes, sendo 23 (82 %) do sexo feminino. A idade média dos pacientes foi de 54,7 (± 20,6) anos e o número médio de sessões de terapia foi 5,6 (± 6,4). Antes do tratamento os pacientes apresentaram os seguintes escores: 18,10 (±9,83) nos aspectos físicos, 13,53 (±8,57) nos funcionais e 15,14 (±7,48) nos emocionais. Após uma média de 5,6 (± 6,4) sessões, houve diminuição significante (p Abstract in english Purpose to check the influence of vestibular rehabilitation concerning the quality of life of individuals through Brazilian questionnaire Dizziness Handicap Inventory applied pre and post-therapy. Methods 28 medical chart of individual of both sexes attended in a public teaching clinic at Belo [...] Horizonte city, in where they were analyzed. On analyzed medical chart patients were been submitted to the questionnaire pre and post individual vestibular rehabilitation. The statistical analysis from the data was done through the paired T-Student test. Results the sample of study medical chart was composed of 28 patients, 23 (82%) of them were female. The average of ages was 54,7 years (±20,6) and the medium number of sessions was 5,6 (± 6,4). Before the treatment patients showed the following scores: 18,10 (±9,83) physics aspects, 13,5 (±8,57) functions and 15,14 (±7,48) emotional. After medium of 5,6 (± 6,4) sessions, there was a significant reduction in the physics 4,32 (±5,32), functions 4,32 (±6,91) and emotional 3,78 (±5,16) aspects. Conclusion it can be conclude that there was a significant statistic difference between the questionnaire scores pre and post personalized vestibular rehabilitation, showing that the vestibular rehabilitation is an important instrument on the improvement of life quality for with labyrinth disease.

  6. Potencial evocado miogênico vestibular (Vemp: avaliação das respostas em indivíduos normais Vestibular evoked myogenic potential (Vemp: evaluation of responses in normal subjects

    Directory of Open Access Journals (Sweden)

    Lilian Felipe

    2008-12-01

    Full Text Available TEMA: o Potencial Evocado Miogênico Vestibular (Vemp é formado por respostas miogênicas ativadas por estimulação sonora de alta intensidade. Essas respostas são registradas por eletromiografia de superfície sobre a musculatura cervical na presença de contração muscular, ativando a mácula, o nervo vestibular inferior e as vias vestíbulo-espinhais descendentes. OBJETIVO: descrever as respostas evocadas do Vemp em uma população normal. MÉTODO: selecionaram-se 30 sujeitos adultos, sendo 13 homens e 17 mulheres, sem queixas otoneurológicas. Utilizou-se 200 estímulos tone burst com freqüência de 1Hz e intensidade de 118dB Na, filtro passa-banda de 10Hz a 1500Hz. Os traçados obtidos foram analisados em relação ao primeiro potencial bifásico composto por P13 e N23. RESULTADOS: não houve diferença estatisticamente significativa entre o lado da estimulação em relação a latência e amplitude, porém foi encontrada diferença estatisticamente significativa em relação à amplitude do potencial entre os sexos. CONCLUSÃO: Vemp demonstrou ser uma ferramenta confiável na avaliação da função vestibular.BACKGROUND: the Vestibular Evoked Myogenic Potential (Vemp is formed by myogenic neurophysiologic responses activated by high-intensity sound stimulation. The response is registered through surface electromyography of the cervical muscles during muscle contraction. The acoustic stimuli activate the saccular macula, the vestibular inferior nerve and the pathways related to the vestibule-spinal descendant nerves. AIM: to describe Vemp parameters in a normal population. METHODS: thirty adults, 13 men and 17 women with no otoneurological complaints were selected. The stimuli were 200 tone burst, with a frequency of 1Hz and intensity of 118 dB Na, band-pass filter ranging from 10Hz to 1500Hz. The first potential biphasic P13-N23 wave was analyzed. RESULTS: no significant difference was observed between the sides of stimulation in terms of latency and amplitude. However, a statistically significant difference was found for amplitude between genders. CONCLUSION: Vemp demonstrated to be a reliable instrument in the clinical assessment of the vestibular function.

  7. Tratamiento de schwanomas vestibulares esporádicos mediante radiocirugía: Estudio prospectivo de cohorte Radiosurgical treatment of sporadic vestibular schwannomas: A prospective cohort study

    Directory of Open Access Journals (Sweden)

    Freddy Martel V

    2008-12-01

    Full Text Available Objetivo: Analizar los resultados iniciales de un estudio prospectivo en pacientes con schwanomas vestibulares tratados con radiocirugía en la Pontificia Universidad Católica de Chile. Material y método: Se presentan 17 pacientes portadores de schwanomas vestibulares esporádicos tratados con radiocirugía y seguidos entre 6 y 26 meses. El tratamiento fue realizado con acelerador lineal Varían clinac21 EX, con equipamiento Varían-Zmed. La dosis marginal administrada al tumor fue de 12 a 12,5 Gray El seguimiento a 6, 12 y 24 meses consta de resonancia magnética, audiometríay evaluación clínica. Resultados: La dosis marginal de irradiación usada fue entre 12y 12,5 Gray normalizada a la isodosis 70% u 80%. En todos los pacientes se documentó disminución de la captación de contraste del tumor y en 16 (94% se observaron áreas de necrosis centro tumoral. No hubo mortalidad, la preservación de audición útil fue 62,5% actuaría! a 2 años. No ha existido deterioro de la función de los nervios facial ni trigémino. Todos los pacientes que previamente estaban trabajando retornaron a sus labores en promedio 11,5 días luego del tratamiento. Conclusiones: Los resultados iniciales de esta serieison comparables a los resultados publicados en la literatura y refuerzan el demostrado rol de la radiocirugía en el tratamiento de los schwanomas vestibulares.Objective: To analyze the preliminary experience of radiosurgery for Vestibular Schwannomas at the Pontificia Universidad Católica de Chile. Material and methods: Thefirst 17 patients with sporadic Vestibular Schwannomas treated by radiosurgery at our institution are reponed. The marginal dose used was 12 to 12.5 Gy. prescribed at the 70 or 80 isodose Une. Patients were controlled at 6, 12 and 24 months with magnetic resonance, audiometric study and clinical examination. Results: In all of the 17 patients treated a decrease tumor enhancement on MR was demonstrated. In 16 patients (94% a pattern of central tumor necrosis was observed during the firsyear Actuaría! useful hearing was maintained in 62.5% at 2 year after treatment. Facial nerve function was maintained in all of the 15 patients with normal function at treatment (100%. Trigémina! function was maintained in all of the 14 patients (100% with previous normal trigeminal function. The mean time to return to work or normal activities was 11.5 days after treatment Conclusions: These preliminary results are comparable with results published in the literature and reinforce the demónstrate role oí radiosurgery in the management oí vestibular schwannomas.

  8. Highlighting the Neuron

    Science.gov (United States)

    Robotics Engineering for Better Life and Sustainable Future RET,

    In this lesson on the brain's neural networks, students investigate the structure and function of the neuron. They discover ways in which engineers apply this knowledge to the development of devices that can activate neurons. After a review of the nervous system—specifically its organs, tissue, and specialized cells, called neurons—students learn about the parts of the neuron. They explore the cell body, dendrites, axon and axon terminal, and learn how these structures enable neurons to send messages. They learn about the connections between engineering and other fields of study, and the importance of research, as they complete the lesson tasks.

  9. The role of radiology in the diagnosis and management of vestibular schwannoma

    International Nuclear Information System (INIS)

    The most frequent lesion identified at the cerebellopontine angle cistern and internal auditory meatus (IAM) is the vestibular schwannoma. Radiological features, the role of imaging in screening and follow-up, therapeutic approaches and appearances following treatment will be discussed. Other cerebellopontine angle lesions will be illustrated and an algorithm presented to help in the imaging differential diagnosis. Whilst lesions other than vestibular schwannomas are rarely isolated to the IAM, the key clinical and radiological features that should raise the possibility of alternative neoplastic and inflammatory diseases will be highlighted.

  10. Maslow's Hierarchy of Needs and the individual with chronic vestibular dysfunction.

    Science.gov (United States)

    Haybach, P J

    1994-01-01

    Individuals with chronic vestibular dysfunction may have unmet physiological or safety needs on a chronic basis. Their inability to fulfill the basic needs and progress to higher needs can lead to a patient population with many psychosocial problems. Very often such problems are ignored or unrecognized or are misdiagnosed, and treated inappropriately. This disruption in the individual's life can lead to an inability to progress as a human being. Nursing assessment and appropriate interventions should be developed to treat psychosocial problems in this patient population. The nursing profession should serve patients with vestibular dysfunction through direct care, teaching, counseling, support group facilitation, and research into appropriate interventions. PMID:8564758

  11. Condition of the vestibular analyzer in dogs after prolonged irradiation in small doses

    Science.gov (United States)

    Kumets, P. I.

    1973-01-01

    The functional condition of the vestibular analyzer in sixty dogs, some of which were subjected to continuous radiation action in overall doses of 25-225 rads/year were evaluated. Six dogs were given medical preventive agents. Quantitative evaluation of the functional conditions of the vestibular analyzers showed an increase in excitability of the spatial analyzer by 35-40% in animals which had been irradiated with a total dosage of 225 rads/year. Observed is a tendency towards decrease of excitability and increase of reactivity in the group of animals which had been irradiated with a dose of 225 rads/year and which had received medical preventive agents.

  12. 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.

  13. Socio-demographic distribution of vestibular schwannomas in Denmark

    DEFF Research Database (Denmark)

    Stepanidis, Karen; Kessel, Marie

    2014-01-01

    CONCLUSION: Vestibular schwannomas (VSs) are diagnosed less frequently in the remote parts of Denmark, whereas the diagnostic age and tumor size is the same across the different socio-demographic areas of Denmark. OBJECTIVE: To determine whether VSs are diagnosed equally often in different socio-demographic areas of Denmark and whether a change has occurred during the period 1976-2012. In addition, differences in diagnostic age and tumor size between areas were explored. METHODS: Since 1976, all patients diagnosed with a VS in Denmark have been registered in a national database, in which information on, for example, the size of the tumor and the age and address of the patient has been registered. Up to 2012, 2739 patients were diagnosed with a VS. Patient distribution according to area of habitat was determined by subgrouping into urban, suburban, rural, and remote municipalities, using the definitions of socio-demographic areas elaborated by Demarks Statistic. RESULTS: The mean national incidence increased almost linearly over the time period from 6.1 per million per year in the first period from 1976 to 1984, to 22.1 per million per year in the last period from 2003 to 2012. There was a lower incidence at the end of the period in the remote areas compared with the other socio-demographic areas (1976-1984, p = 0.05 and 2003-2011, p = 0.001). The mean age at diagnosis increased during the period, from 52.6 years in the first period to 58.6 years in the last period. There was no significant difference in the age distribution between socio- demographic areas. The mean diagnostic tumor size decreased during the period, from 28.6 mm in the first period to about 10 mm in the last period. There was no significant difference in the size of the tumor between socio- demographic areas.

  14. Maxi K+ channel in apical membrane of vestibular dark cells.

    Science.gov (United States)

    Takeuchi, S; Marcus, D C; Wangemann, P

    1992-06-01

    Recordings were made on excised apical membrane patches from vestibular dark cells from the semicircular canal of gerbils to determine if ion channels could be involved in the process of K+ secretion. Both nonselective cation channels [Am. J. Physiol. 262 (Cell Physiol. 31): C1430-C1436, 1992] and K(+)-selective channels were found. The K+ channels occurred in only 0.7% of the patches. In symmetrical 145 mM KCl solutions, the current-voltage (I-V) relation of the K(+)-selective channel was linear, indicating the absence of rectification, and the conductance was 240 +/- 8 pS (n = 8). The Goldman-Hodgkin-Katz equation for current carried solely by K+ could be fitted to the I-V relation in asymmetrical K+ and Na+ solutions and yielded a K+ permeability of 5.78 x 10(-13) cm3/s (n = 12). The channel was shown to be impermeable to Li+, NH4+, N-methyl-D-glucamine, and Cl-. Channel activity increased with depolarization and with increasing free [Ca2+]; for voltages between +40 and -60 mV, the strongest regulation occurred in the range 10(-6) to 10(-5) M Ca2+. Tetraethylammonium (2 x 10(-2) M) had from the cytosolic side no effect on the open probability (Po) but completely inhibited activity from the extracellular side. Po was reduced by Ba2+ (5 x 10(-3) M), verapamil (10(-4) M), quinine (10(-4) M), and quinidine (10(-4) and 10(-3) M), while lidocaine (5 x 10(-3) M) had no measurable effect on Po but decreased the amplitude. Rb+ and Cs+ were either poorly permeable or partially blocked the channel in a voltage-dependent manner.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1616010

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

    DEFF Research Database (Denmark)

    Schüz, Joachim; Steding-Jessen, Marianne

    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-linear Poisson regression models were used to estimate incidence rate ratios (IRRs). Linear regression models were used to examine the association between sociodemographic indicators and tumor size. We found that IRRs decreased gradually with decreasing level of education, with values of 0.62 (95% CI: 0.49-0.78) for men and 0.62 (95% CI: 0.50-0.77) for women with a basic education compared with a higher education. Similar results were found for disposable income. Marital status was associated with a higher incidence of VS in men but not women; nonmarried men with a basic education had an IRR of 0.34 (95% CI: 0.23-0.50) compared with married men with a higher education. Lower incidence rates were also observed among unemployed or early-retirement pensioners, whereas there were no differences in incidence rates across the broad groups of occupations and across the types of districts. Sociodemographic indicators were not associated with the tumor size. The magnitude of the differences in incidence rates across the groups of different socioeconomic indicators suggests a high potential for earlier diagnosis of VS by improving the awareness of early symptoms.

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

    Science.gov (United States)

    Mulavara, A. P.; Kofman, I. S.; De Dios, Y. E; Galvan, R.; Goel, R.; Miller, C.; Peters, B.; Cohen, H. S.; Jeevarajan, J.; Reschke, M.; Wood, S.; Bergquist, F.; Seidler, R. D.; Bloomberg, J. J.

    2014-01-01

    Crewmember adapted to the microgravity state may need to egress the vehicle within a few minutes for safety and operational reasons after gravitational transitions. The transition from one sensorimotor state to another consists of two main mechanisms: strategic and plastic-adaptive and have been demonstrated in astronauts returning after long duration space flight. Strategic modifications represent "early adaptation" - immediate and transitory changes in control that are employed to deal with short-term changes in the environment. If these modifications are prolonged then plastic-adaptive changes are evoked that modify central nervous system function, automating new behavioral responses. More importantly, this longer term adaptive recovery mechanism was significantly associated with their strategic ability to recover on the first day after return to Earth G. We are developing a method based on stochastic resonance to enhance information transfer by improving the brain's ability to detect vestibular signals (Vestibular Stochastic Resonance, VSR) especially when combined with balance training exercises such as sensorimotor adaptability (SA) training for rapid improvement in functional skill, for standing and mobility. This countermeasure to improve detection of vestibular signals is a stimulus delivery system that is wearable/portable providing low imperceptible levels of white noise based binaural bipolar electrical stimulation of the vestibular system (stochastic vestibular stimulation). To determine efficacy of vestibular stimulation on physiological and perceptual responses during otolith-canal conflicts and dynamic perturbations we have conducted a series of studies: We have shown that imperceptible binaural bipolar electrical stimulation of the vestibular system across the mastoids enhances balance performance in the mediolateral (ML) plane while standing on an unstable surface. We have followed up on the previous study showing VSR stimulation improved balance performance in both ML and anteroposterior planes while stimulating in the ML axis only. We have shown the efficacy of VSR stimulations on enhancing physiological and perceptual responses of whole-body orientation during low frequency perturbations (0.1 Hz) on the ocular motor system using a variable radius centrifuge on both physiological (using eye movements) and perceptual responses (using a joystick) to track imposed oscillations. The variable radius centrifuge provides a selective tilting sensation that is detectable only by the otolith organs providing conflicting information from the canal organs of the vestibular system (intra-vestibular conflict). These results indicate that VSR can improve performance in sensory conflict scenarios like that experienced during space flight. We have showed the efficacy of VSR stimulation to improve balance and locomotor control on subjects exposed to continuous, sinusoidal lateral motion of the support surface while walking on a treadmill while viewing perceptually matched linear optic flow. We have shown the safety of short term continuous use of up to 4 hours of VSR stimulation and its efficacy in improving balance and locomotor function in Parkinson's Disease patients. This technique for improving vestibular signal detection may thus provide additional information to improve strategic abilities. We hypothesize that VSR stimulation will act synergistically with SA training to improve adaptability by increased utilization of vestibular information and therefore serve to optimize and personalize the SA countermeasure prescription. This forms the basis of its usefulness both as a training modality and further help in significantly reducing the number of days required to recover functional performance to preflight levels after long duration space flight.

  17. Análise funcional da laringe pós-cordectomia, reconstruída com retalho de prega vestibular / Functional analysis of post-cordectomy larynx reconstructed with vestibular fold flap

    Scientific Electronic Library Online (English)

    Hilton, Ricz; Rui C. M., Mamede; Lílian, Aguiar-Ricz.

    2004-12-01

    Full Text Available Várias técnicas para a reconstrução da laringe, pós laringectomias parciais verticais, são citadas na literatura, algumas utilizando estruturas da própria laringe, como a prega vestibular, porém, poucas dão destaque à análise das funções laríngeas após estas reconstruções. Este estudo teve como obje [...] tivo avaliar as funções laríngeas em pacientes submetidos à cordectomia completa (tipo IV), reconstruídos com retalho de prega vestibular. FORMA DE ESTUDO: Estudo de coorte transversal. MATERIAL E MÉTODO: Dez pacientes, nove do sexo masculino e um do sexo feminino, com idades entre 45 e 75 anos, e média de 64,5, com carcinomas glóticos tratados por cordectomias totais ou completas (tipo IV) e reconstruídos com retalho de prega vestibular, foram submetidos a videolaringoestroboscopia, onde se avaliou a permeabilidade laríngea, o posicionamento do retalho, o fechamento laríngeo, a movimentação das aritenóides e a característica da fonte sonora: vibrátil ou friccional, e quando vibrátil, a localização e as estruturas que a compunham. A qualidade vocal foi analisada por avaliação perceptiva auditiva e objetiva computadorizada. A função de proteção das vias aéreas durante a deglutição foi realizada pela avaliação endoscópica da deglutição. RESULTADOS: Os resultados evidenciaram que não houve necessidade de manter a traqueostomia no pós-operatório tardio, pois a luz laríngea reconstruída mantinha-se pérvia. A função de proteção estava mantida em todos os casos, a coaptação completa em 30% e somente um paciente teve a movimentação da aritenóide limitada devido à imobilidade do lado operado. Evidenciaram, também, que havia fonte sonora vibrátil em 90% dos casos e que em todos a prega vestibular participava da sua composição. Em sete pacientes a fonte sonora vibrátil se localizava na região glótica. A análise computadorizada revelou freqüência fundamental média de 177,5 Hz, jitter médio de 1,11% e shimmer de 7,04%. Pela escala GRBAS, um paciente apresentou voz normal e 4 tiveram disfonia discreta. CONCLUSÕES: A reconstrução laríngea pós-cordectomia realizada com o retalho da prega vestibular tornou possível emissão de voz normal (freqüência fundamental 205 Hz, jitter 0,13%, shimmer 1,16%), proporcionando coaptação completa em 30% dos casos, fonte sonora vibrátil na região glótica em 70% e participação do retalho como estrutura vibrátil em 90%, além de preservar as funções laríngeas de respiração e proteção das vias aéreas durante a deglutição. Abstract in english Several reports of techniques for larynx reconstruction after partial vertical laryngectomy are available in the literature, some of them using structures of the larynx itself such as the vestibular fold, but few have emphasized analysis of laryngeal function after reconstruction. Thus, the objectiv [...] e of the present study was to assess laryngeal function in patients submitted to total or complete cordectomy (type IV) followed by reconstruction with vestibular fold flap. STUDY DESIGN: Cohort transversal. MATERIAL AND METHODS: Ten patients, nine males and one female aged 45 to 75 years (mean age: 64.5 years), with glottis carcinomas treated by total or complete cordectomy (type IV) and reconstructed with vestibular fold flap were submitted to videolaryngostroboscopy for assessment of laryngeal permeability, flap positioning, laryngeal closure, arytenoid movement, characteristics of speech sound source (vibrating or frictional) and, when the source was vibrating, location and structures of the sound source. Voice quality was evaluated by perceptual acoustic assessment and by objective computer analysis. The function of lower airway protection during swallowing was analyzed by endoscopic evaluation of swallowing. RESULTS: There was no need to maintain tracheostomy during the late postoperative period since the reconstructed laryngeal lumen remained pervious. The function of airway protection during swallowing was preserved in all patients, with

  18. Potencial evocado auditivo para diagnóstico de surdez em gato com síndrome vestibular periférica / Auditory evoked potential for deafness diagnosis in a cat with peripheral vestibular syndrome

    Scientific Electronic Library Online (English)

    M.I.P., Palumbo; P.C., Jark; L.H.A., Machado; V.M.V., Machado; L.A.L., Resende; A.S., Borges.

    1681-16-01

    Full Text Available Potencial evocado auditivo é um método eletrodiagnóstico que permite avaliação funcional das vias auditivas desde a orelha média até o tronco encefálico. O uso desse teste em medicina veterinária é pouco difundido no Brasil. O presente artigo relata o uso do potencial evocado auditivo para detecção [...] de deficiência auditiva unilateral em um gato com síndrome vestibular periférica secundária a otite média. Abstract in english The brainstem auditory evoked potential is an electrodiagnostic test that allows a functional assessment of the auditory pathways from the middle ear to the brainstem. This test, in veterinary medicine, is not commonly used in Brazil. This paper reports the use of auditory evoked potential for deafn [...] ess detection in a cat with unilateral peripheral vestibular syndrome secondary to otitis media.

  19. Study of a New Neuron

    OpenAIRE

    Adler, S. L.; Bhanot, G. V.; Weckel, J. D.

    1994-01-01

    We study a modular neuron alternative to the McCulloch-Pitts neuron that arises naturally in analog devices in which the neuron inputs are represented as coherent oscillatory wave signals. Although the modular neuron can compute $XOR$ at the one neuron level, it is still characterized by the same Vapnik-Chervonenkis dimension as the standard neuron. We give the formulas needed for constructing networks using the new neuron and training them using back-propagation. A numerica...

  20. Electrified minds: transcranial direct current stimulation (tDCS) and galvanic vestibular stimulation (GVS) as methods of non-invasive brain stimulation in neuropsychology--a review of current data and future implications.

    Science.gov (United States)

    Utz, Kathrin S; Dimova, Violeta; Oppenländer, Karin; Kerkhoff, Georg

    2010-08-01

    Transcranial direct current stimulation (tDCS) is a noninvasive, low-cost and easy-to-use technique that can be applied to modify cerebral excitability. This is achieved by weak direct currents to shift the resting potential of cortical neurons. These currents are applied by attaching two electrodes (usually one anode and one cathode) to distinct areas of the skull. Galvanic Vestibular Stimulation (GVS) is a variant of tDCS where the electrodes are attached to the mastoids behind the ears in order to stimulate the vestibular system. tDCS and GVS are safe when standard procedures are used. We describe the basic physiological mechanisms and application of these procedures. We also review current data on the effects of tDCS and GVS in healthy subjects as well as clinical populations. Significant effects of such stimulation have been reported for motor, visual, somatosensory, attentional, vestibular and cognitive/emotional function as well as for a range of neurological and psychiatric disorders. Moreover, both techniques may induce neuroplastic changes which make them promising techniques in the field of neurorehabilitation. A number of open research questions that could be addressed with tDCS or GVS are formulated in the domains of sensory and motor processing, spatial and nonspatial attention including neglect, spatial cognition and body cognition disorders, as well as novel treatments for various neuropsychological disorders. We conclude that the literature suggests that tDCS and GVS are exciting and easily applicable research tools for neuropsychological as well as clinical-therapeutic investigations. PMID:20542047

  1. Utilidad de la electronistagmografía en el diagnóstico topográfico de las enfermedades vestibulares Usefulness of electronistagmography in the topographic diagnosis of vestibular diseases

    Directory of Open Access Journals (Sweden)

    Eulalia Alfonso Muñoz

    2008-06-01

    Full Text Available Se estudiaron 50 pacientes que presentaron enfermedad vestibular durante un período de 2 años, con el objetivo de determinar cómo contribuye la electronistagmografía al diagnóstico topográfico en pacientes con estas afecciones. Está demostrado que la aplicación correcta de la práctica clínica y el interrogatorio no es sustituible por alguna prueba diagnóstica y de hecho, se sabe que en el estudio del paciente con vértigo, lo antes expresado constituye lo más importante. Sin embargo, existe aproximadamente un 30 % de estos enfermos con diagnóstico dudoso, donde las pruebas complementarias desempeñan una función fundamental. De los casos estudiados, el 78,0 % correspondió al sexo femenino y predominaron las edades de 50 a 59 años (52,0 %. Las causas más comúnmente encontradas fueron la vascular (32,0 %, seguida en orden de frecuencia por las secuelas de enfermedades vírales (20,0 %. Se concluye que la electronistagmografía es una prueba con un carácter objetivo fundamental para diagnóstico topográfico de las enfermedades vestibulares.50 patients that presented vestibular disease during 2 years were studied aimed at determining how electronistagmography contributes to the topographic diagnosis in patients with these affections. It has been proved that the adequate application of clinical practice and interview cannot be replaced by any diagnostic test and, in fact, it is known that in the study of the patient suffering from vertigo, the above mentioned is the most important. However, approximately 30 % of these patients have an uncertain diagnosis, where the complementary tests play a fundamental role. Of the studied cases, 78.0 % were females and it was observed a predominance of ages 50-59 (52.0 %. The most common causes were the vascular (32.0 %, followed by the sequelae of viral diseases (20.0 %. It was concluded that electronistagmography is a test with an essential objective character for the topographic diagnosis of the vestibular diseases.

  2. Potencial miogênico evocado vestibular: proposição de um novo instrumento / Vestibular evoked myogenic potential: we propose a new instrument

    Scientific Electronic Library Online (English)

    Aline Cabral de, Oliveira; José Fernando, Colafêmina; Pedro de Lemos, Menezes.

    2010-12-01

    Full Text Available INTRODUÇÃO: Atualmente, ainda não existe um instrumento específico para a avaliação dos potencias miogênicos evocados vestibulares, sendo a mesma realizada por meio de um equipamento desenvolvido para a captação de potenciais evocados auditivos, disponível no mercado. Assim, as funções de amplificaç [...] ão, filtragem, estimulação, janela de captação, rejeição de artefatos e características de promediação, bem como o próprio software de gerenciamento, ficam muito a desejar para a nova função que lhe é atribuída. OBJETIVO: Comparar latências e amplitudes das componentes p13 e n23, e os índices de assimetria, entre um equipamento considerado padrão-ouro (EP25), adaptado para o registro deste potencial, e o novo equipamento desenvolvido. MÉTODO: Estudo experimental com 11 ouvintes normais. A partir de estímulos sonoros tone-burst de 10 ms, frequência de 500 Hz, com intensidade de 90 dBNAn, foram registrados potenciais miogênicos evocados com janelas de 80 ms. RESULTADOS: Pode-se constatar ausência de diferenças significativas, quando comparados os dois instrumentos, quanto aos parâmetros de latência e amplitude, exceto para a latência de n23, com valor de p = 0,005. O valor do índice de assimetria inter-pico p13-n23, para o novo aparelho (20,1%), foi significativamente menor que o encontrado para o EP25 (30,5%), com p menor que 0,01. CONCLUSÃO: Desta forma, conclui-se, que não existem diferenças para as latências e amplitudes do VEMP entre o EP25 e o novo dispositivo desenvolvido, apresentando, este último, maior proximidade com os valores descritos na literatura e menor índice de assimetria da amplitude inter-pico p13-n23. Forma de estudo: prospectivo, clínico e experimental. Abstract in english INTRODUCTION: Currently, there is still no specific instrument for assessment of vestibular evoked myogenic potentials, with the same performed by a device designed to capture auditory evoked potentials available in the market. Thus, the functions of amplification, filtering, stimulation, window cap [...] ture, rejection of artifacts and features of averaging, as well as its management software, are much to be desired for the new role assigned to it. OBJECTIVE: To compare latencies and amplitudes of components p13 and n23, and the indices of asymmetry between a devices considered the gold standard (EP25), adapted to record the potential and the new equipment developed. METHOD: An experimental study with 11 normal hearing. From the tone-burst sound stimuli of 10 ms, frequency of 500 Hz with intensity 90 dBNAn, evoked myogenic potentials were recorded with 80 ms windows. RESULTS: You can see no significant differences when comparing the two instruments regarding the parameters of latency and amplitude, except for the latency of n23, with p = 0.005. The value of asymmetry index inter-p13-n23 peak for the new unit (20.1%) was significantly lower than that found for the EP25 (30.5%), with p less than 0.01. Conclusion: Thus, we conclude that there are no differences for the latencies and amplitudes of VEMP between the EP25 and the new device developed by presenting the latter, closer to the values reported in literature and a lower index of asymmetry of amplitude between p13-n23 peak. Study form: Prospective clinical and experimental.

  3. Reabilitação vestibular com realidade virtual na doença de Ménière Vestibular rehabilitation with virtual reality in Ménière's disease

    Directory of Open Access Journals (Sweden)

    Adriana Pontin Garcia

    2013-06-01

    Full Text Available A tecnologia de realidade virtual fornece uma grande variedade de estímulos que geram conflitos sensoriais em diferentes níveis de dificuldades e em ambiente seguro. OBJETIVO: Verificar o efeito de um programa de reabilitação vestibular do equilíbrio corporal com estímulos de realidade virtual em pacientes com doença de Ménière. Forma de estudo: Estudo clínico observacional. MÉTODO: Quarenta e quatro pacientes, com idade entre 18 e 60 anos e doença de Ménière definida, distribuídos em dois grupos - experimental (GE e controle (GC - fizeram uso de betaistina e dieta alimentar; o grupo experimental foi submetido adicionalmente a 12 sessões de reabilitação com realidade virtual da BRU TM. Os pacientes responderam ao Dizziness Handicap Inventory (DHI, à escala analógica de tontura e realizaram a posturografia com realidade virtual antes e após a intervenção. RESULTADOS: Após a intervenção, o GE apresentou valores significantemente menores do DHI (p Virtual reality technology can provide a wide range of sensory stimuli to generate conflicts of varying degrees of complexity in a safe environment. OBJECTIVE: To verify the effect of a virtual realitybased balance rehabilitation program for patients with Menière's disease. METHOD: This observational clinical study included 44 patients aged between 18 and 60 years diagnosed with Menière's disease submitted to a controlled randomized therapeutic intervention. The case and control groups took betahistine and followed a diet. Case group subjects underwent 12 rehabilitation sessions with virtual reality stimuli in a Balance Rehabilitation Unit (BRU TM. Patients were assessed based on DHI scores, the dizziness visual analogue scale, and underwent posturography with virtual reality before and after the intervention. RESULTS: After the intervention, the case group showed significantly lower scores in DHI (p < 0,001 and in the dizziness visual analog scale (p = 0.012, and had significantly greater limit of stability areas (p = 0.016 than controls. CONCLUSION: Virtual reality-based balance rehabilitation effectively improved dizziness, quality of life, and limit of stability of patients with Menière's disease.

  4. Reabilitação vestibular com realidade virtual na doença de Ménière / Vestibular rehabilitation with virtual reality in Ménière's disease

    Scientific Electronic Library Online (English)

    Adriana Pontin, Garcia; Mauricio Malavasi, Ganança; Flávia Salvaterra, Cusin; Andreza, Tomaz; Fernando Freitas, Ganança; Heloisa Helena, Caovilla.

    2013-06-01

    Full Text Available A tecnologia de realidade virtual fornece uma grande variedade de estímulos que geram conflitos sensoriais em diferentes níveis de dificuldades e em ambiente seguro. OBJETIVO: Verificar o efeito de um programa de reabilitação vestibular do equilíbrio corporal com estímulos de realidade virtual em pa [...] cientes com doença de Ménière. Forma de estudo: Estudo clínico observacional. MÉTODO: Quarenta e quatro pacientes, com idade entre 18 e 60 anos e doença de Ménière definida, distribuídos em dois grupos - experimental (GE) e controle (GC) - fizeram uso de betaistina e dieta alimentar; o grupo experimental foi submetido adicionalmente a 12 sessões de reabilitação com realidade virtual da BRU TM. Os pacientes responderam ao Dizziness Handicap Inventory (DHI), à escala analógica de tontura e realizaram a posturografia com realidade virtual antes e após a intervenção. RESULTADOS: Após a intervenção, o GE apresentou valores significantemente menores do DHI (p Abstract in english Virtual reality technology can provide a wide range of sensory stimuli to generate conflicts of varying degrees of complexity in a safe environment. OBJECTIVE: To verify the effect of a virtual realitybased balance rehabilitation program for patients with Menière's disease. METHOD: This observationa [...] l clinical study included 44 patients aged between 18 and 60 years diagnosed with Menière's disease submitted to a controlled randomized therapeutic intervention. The case and control groups took betahistine and followed a diet. Case group subjects underwent 12 rehabilitation sessions with virtual reality stimuli in a Balance Rehabilitation Unit (BRU TM). Patients were assessed based on DHI scores, the dizziness visual analogue scale, and underwent posturography with virtual reality before and after the intervention. RESULTS: After the intervention, the case group showed significantly lower scores in DHI (p

  5. Implante coclear e síndrome do aqueduto vestibular alargado em crianças / Cochlear implant and large vestibular aqueduct syndrome in children

    Scientific Electronic Library Online (English)

    Trissia Maria Farah, Vassoler; Gilberto da Fontoura Rey, Bergonse; Silvio, Meira Junior; Maria Cecília, Bevilacqua; Orozimbo Alves, Costa Filho.

    2008-04-01

    Full Text Available Crianças com SAVA podem ter deficiências auditivas moderadas a severas durante fases precoces da infância, porém sua audição residual permite que elas desenvolvam linguagem oral com aparelhos auditivos convencionais e possam estar completamente integradas a condições escolares regulares. Contudo, es [...] tas crianças apresentam uma deterioração de sua habilidade auditiva com o decorrer do tempo e o implante coclear está sendo utilizado como uma opção para manter a habilidade auditiva. OBJETIVO: Avaliação da habilidade auditiva de 3 crianças com SAVA submetidas a implante coclear. MATERIAIS: Estudo retrospectivo baseado em revisão de prontuários. RESULTADOS: Em reconhecimento de palavras em campo aberto paciente 1, 80%, paciente 2, 87,5%, paciente 3, 4%. CONCLUSÃO: Os pacientes com aqueduto vestibular alargado são considerados bons candidatos para implante coclear pelos principais centros de implante coclear do mundo, por desenvolverem, em sua maioria, bons resultados de percepção de fala, o que leva estes pacientes a uma boa inserção social. Abstract in english Children with LVAS can develop a severe sensorineural hearing loss early in childhood, but they can be rehabilitated with hearing aids to continue their regular studies and to have a normal life. The problem is that they can deteriorate their hearing capacity, and at this point a cochlear implant ca [...] n be used to preserve their hearing skills and vocalization. AIM: to evaluate the hearing skills of 3 children with LVAS referred to cochlear implants. MATERIAL: retrospective study based on medical charts' review. RESULTS: Speech recognition in open field: patient 1, 80%; patient 2, 87.5%; patient 3, 4 %. CONCLUSION: Children with LVAS are considered good candidates for Cochlear implant surgery by the most important centers of the world because most of them can develop good speech recognition, providing them a good social life.

  6. Implante coclear e síndrome do aqueduto vestibular alargado em crianças Cochlear implant and large vestibular aqueduct syndrome in children

    Directory of Open Access Journals (Sweden)

    Trissia Maria Farah Vassoler

    2008-04-01

    Full Text Available Crianças com SAVA podem ter deficiências auditivas moderadas a severas durante fases precoces da infância, porém sua audição residual permite que elas desenvolvam linguagem oral com aparelhos auditivos convencionais e possam estar completamente integradas a condições escolares regulares. Contudo, estas crianças apresentam uma deterioração de sua habilidade auditiva com o decorrer do tempo e o implante coclear está sendo utilizado como uma opção para manter a habilidade auditiva. OBJETIVO: Avaliação da habilidade auditiva de 3 crianças com SAVA submetidas a implante coclear. MATERIAIS: Estudo retrospectivo baseado em revisão de prontuários. RESULTADOS: Em reconhecimento de palavras em campo aberto paciente 1, 80%, paciente 2, 87,5%, paciente 3, 4%. CONCLUSÃO: Os pacientes com aqueduto vestibular alargado são considerados bons candidatos para implante coclear pelos principais centros de implante coclear do mundo, por desenvolverem, em sua maioria, bons resultados de percepção de fala, o que leva estes pacientes a uma boa inserção social.Children with LVAS can develop a severe sensorineural hearing loss early in childhood, but they can be rehabilitated with hearing aids to continue their regular studies and to have a normal life. The problem is that they can deteriorate their hearing capacity, and at this point a cochlear implant can be used to preserve their hearing skills and vocalization. AIM: to evaluate the hearing skills of 3 children with LVAS referred to cochlear implants. MATERIAL: retrospective study based on medical charts' review. RESULTS: Speech recognition in open field: patient 1, 80%; patient 2, 87.5%; patient 3, 4 %. CONCLUSION: Children with LVAS are considered good candidates for Cochlear implant surgery by the most important centers of the world because most of them can develop good speech recognition, providing them a good social life.

  7. Effects of intratympanic gentamicin on vestibular afferents and hair cells in the chinchilla.

    Science.gov (United States)

    Hirvonen, Timo P; Minor, Lloyd B; Hullar, Timothy E; Carey, John P

    2005-02-01

    Gentamicin is toxic to vestibular hair cells, but its effects on vestibular afferents have not been defined. We treated anesthetized chinchillas with one injection of gentamicin (26.7 mg/ml) into the middle ear and made extracellular recordings from afferents after 5-25 (early) or 90-115 days (late). The relative proportions of regular, intermediate, and irregular afferents did not change after treatment. The spontaneous firing rate of regular afferents was lower (P galvanic currents was unaffected for all afferents. Intratympanic gentamicin treatment reduced the histological density of all hair cells by 57% (P = 0.04). The density of hair cells with calyx endings was reduced by 99% (P = 0.03), although some remaining hair cells had other features suggestive of type I morphology. Type II hair cell density was not significantly reduced. These findings suggest that a single intratympanic gentamicin injection causes partial damage and loss of vestibular hair cells, particularly type I hair cells or their calyceal afferent endings, does not damage the afferent spike initiation zones, and preserves enough hair cell synaptic activity to drive the spontaneous activity of vestibular afferents. PMID:15456806

  8. The effect of preterm birth on vestibular evoked myogenic potentials in children

    Science.gov (United States)

    Eshaghi, Zahra; Jafari, Zahra; Shaibanizadeh, Abdolreza; Jalaie, Shohreh; Ghaseminejad, Azizeh

    2014-01-01

    Background: Preterm birth is a significant global health problem with serious short- and long-term consequences. This study examined the long term effects of preterm birth on vestibular evoked myogenic potentials (VEMPs) among preschool-aged children. Methods: Thirty-one children with preterm and 20 children with term birth histories aged 5.5 to 6.5 years were studied. Each child underwent VEMPs testing using a 500 Hz tone-burst stimulus with a 95 dB nHL (normal hearing level) intensity level. Results: The mean peak latencies of the p13 and n23 waves in the very preterm group were significantly longer than for the full-term group (p? 0.041). There was a significant difference between very and mildly preterm children in the latency of peak p13 (p= 0.003). No significant differences existed between groups for p13-n23 amplitude and the interaural amplitude difference ratio. The tested ear and gender did not affect the results of the test. Conclusion: Prolonged VEMPs in very preterm children may reflect neurodevelopmental impairment and incomplete maturity of the vestibulospinal tract (sacculocollic reflex pathway), especially myelination. VEMPs is a non-invasive technique for investigating the vestibular function in young children, and considered to be an appropriate tool for evaluating vestibular impairments at the low brainstem level. It can be used in follow-ups of the long-term effects of preterm birth on the vestibular system. PMID:25405140

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

    Directory of Open Access Journals (Sweden)

    S Maruthy

    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.

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

    Science.gov (United States)

    An, Sun-Joung Leigh

    2015-01-01

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

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

    Scientific Electronic Library Online (English)

    Marta Maria da Silva, Lira-Batista; Ricardo Schaffeln, Dorigueto; Cristina Freitas, Ganança.

    2013-06-01

    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 vectoelec [...] tronystagmography (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. METHODS: 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 physio