WorldWideScience
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Spatial and temporal segregation of auditory and vestibular neurons in the otic placode  

OpenAIRE

The otic placode generates the auditory and vestibular sense organs and their afferent neurons; however, how auditory and vestibular fates are specified is unknown. We have generated a fate map of the otic placode and show that precursors for vestibular and auditory cells are regionally segregated in the otic epithelium. The anterior-lateral portion of the otic placode generates vestibular neurons, whereas the posterior-medial region gives rise to auditory neurons. Precursors for vestibular a...

Bell, Donald; Streit, Andrea; Gorospe, Itziar; Varela-nieto, Isabel; Alsina, Berta; Giraldez, Fernando

2008-01-01

2

Responses of primary vestibular neurons to galvanic vestibular stimulation (GVS) in the anaesthetised guinea pig.  

Science.gov (United States)

Previous studies in humans and animals which have shown that DC galvanic vestibular stimulation (GVS) induces horizontal and torsional eye movements have been interpreted as being due to a preferential activation of primary vestibular afferents innervating the horizontal semicircular canals and otoliths by GVS. The present study sought to determine in guinea pigs whether GVS does indeed selectively activate primary horizontal canal and otolith afferents. Constant-current GVS was passed between electrodes implanted in the tensor-tympani muscle of each middle ear or between electrodes on the skin over the mastoid. During this stimulation, responses from single primary vestibular neurons were recorded extracellularly by glass microelectrodes in Scarpa's ganglion. Afferents from all vestibular sensory regions were activated by both surface and tensor-tympani galvanic stimulation. Tensor tympani GVS was approximately 10 times more effective than surface GVS. At larger current intensities irregularly discharging afferents showed an asymmetrical response: cathodal stimulation resulted in a larger change in firing (increase) than anodal stimulation (decrease), whereas regularly discharging afferents responded symmetrically to the two polarities of GVS. Across all afferents tuned for different types of natural vestibular stimulation, neuronal sensitivity for GVS was found to increase with discharge variability (as indexed by CV*). Anterior canal afferents showed a slightly higher sensitivity than afferents from other vestibular sensory regions. Hence, the present study concluded that GVS activates primary vestibular afferents innervating all sensory regions in a uniform fashion. Therefore, the specific pattern of GVS-induced eye movements reported in previous studies are not due to differential sensitivity between different vestibular sensory regions, but are likely to reflect an involvement of central processing. PMID:15464864

Kim, Juno; Curthoys, Ian S

2004-09-30

3

FMRFamide-related peptide expression in the vestibular-afferent neurons.  

Science.gov (United States)

Vestibular-afferent neurons innervate hair cells from the sensory epithelia of vestibular end-organs and their action-potential discharge dynamics are driven by linear and angular accelerations of the head. The electrical activity of the vestibular-afferent neurons depends on their intrinsic properties and on the synaptic input from hair cells and from the terminals of the efferent system. Here we report that vestibular-afferent neurons of the rat are immunoreactive to RFamide-related peptides, and that the stronger signal comes from calyx-shaped neuron dendrites, with no signal detected in hair cells or supporting cells. The whole-cell voltage clamp recording of isolated afferent neurons showed that they express robust acid-sensing ionic currents (ASICs). Extracellular multiunit recordings of the vestibular nerve in a preparation in vitro of the rat inner ear showed that the perfusion of FMRFamide (a snail ortholog of this family of neuropeptides) exerts an excitatory effect on the afferent-neurons spike-discharge rate. Because the FMRFamide cannot activate the ASIC but reduces its desensitization generating a more robust current, its effect indicates that the ASIC are tonically active in the vestibular-afferent neurons and modulated by RFamide-like peptides. PMID:22342307

Mercado, Francisco; López, Iván; Ortega, Aida; Almanza, Angélica; Soto, Enrique; Vega, Rosario

2012-03-28

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Integration of vestibular and gastrointestinal inputs by cerebellar fastigial nucleus neurons: multisensory influences on motion sickness.  

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Previous studies demonstrated that ingestion of the emetic compound copper sulfate (CuSO4) alters the responses to vestibular stimulation of a large fraction of neurons in brainstem regions that mediate nausea and vomiting, thereby affecting motion sickness susceptibility. Other studies suggested that the processing of vestibular inputs by cerebellar neurons plays a critical role in generating motion sickness and that neurons in the cerebellar fastigial nucleus receive visceral inputs. These findings raised the hypothesis that stimulation of gastrointestinal receptors by a nauseogenic compound affects the processing of labyrinthine signals by fastigial nucleus neurons. We tested this hypothesis in decerebrate cats by determining the effects of intragastric injection of CuSO4 on the responses of rostral fastigial nucleus to whole-body rotations that activate labyrinthine receptors. Responses to vestibular stimulation of fastigial nucleus neurons were more complex in decerebrate cats than reported previously in conscious felines. In particular, spatiotemporal convergence responses, which reflect the convergence of vestibular inputs with different spatial and temporal properties, were more common in decerebrate than in conscious felines. The firing rate of a small percentage of fastigial nucleus neurons (15%) was altered over 50% by the administration of CuSO4; the firing rate of the majority of these cells decreased. The responses to vestibular stimulation of a majority of these cells were attenuated after the compound was provided. Although these data support our hypothesis, the low fraction of fastigial nucleus neurons whose firing rate and responses to vestibular stimulation were affected by the administration of CuSO4 casts doubt on the notion that nauseogenic visceral inputs modulate motion sickness susceptibility principally through neural pathways that include the cerebellar fastigial nucleus. Instead, it appears that convergence of gastrointestinal and vestibular inputs occurs mainly in the brainstem. PMID:24677139

Catanzaro, Michael F; Miller, Daniel J; Cotter, Lucy A; McCall, Andrew A; Yates, Bill J

2014-08-01

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

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

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

2014-04-01

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Effects of eperisone applied by microiontophoresis on neurons in the medial and lateral vestibular nuclei.  

Science.gov (United States)

Electrophysiological studies were performed to elucidate the mechanism underlying the antivertigo action of eperisone, an antispastic drug, using cats anesthetized with alpha-chloralose. Iontophoretic application of eperisone up to 100 nA produced a dose-dependent inhibition of spike generation upon vestibular nerve stimulation in monosynaptic and polysynaptic neurons of the medial vestibular nucleus (MVN). The inhibition of neurons in the MVN was more prominent than that in the lateral vestibular nucleus. In addition, iontophoretically applied eperisone in doses of 50-100 nA inhibited the orthodromic spike elicited by vestibular nerve stimulation in the MVN monosynaptic neurons projecting to the abducens nucleus (ascending neuron), without affecting that in the MVN neurons projecting to the spinal cord (descending neuron). An inhibition of antidromic spike elicited by abducens nucleus stimulation in the MVN monosynaptic ascending neurons was observed in some cases during application of eperisone. These results suggest that eperisone predominantly inhibits synaptic transmission of the MVN ascending neurons. PMID:3009947

Noma, S; Sasa, M; Ohno, Y; Matsuoka, I; Takaori, S

1986-02-01

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Effects of Cyclic Nucleotide-Gated Channels in Vestibular Nuclear Neurons  

OpenAIRE

This study was designed to investigate the effects an 8-Br-cGMP on the neuronal activity of rat vestibular nuclear cells. Sprague-Dawley rats aged 14 to 16 days were decapitated under ether anesthesia. After treatment with pronase and thermolysin, the dissociated vestibular nuclear cells were transferred into a chamber on an inverted microscope. Spontaneous action potentials and potassium currents were recorded by standard patch-clamp techniques under current and voltage-clamp modes. Twelve v...

Heo, Tag; Jang, Sujeong; Jeong, Han-seong; Park, Jong-seong

2011-01-01

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Ion Channels Set Spike Timing Regularity of Mammalian Vestibular Afferent Neurons  

OpenAIRE

In the mammalian vestibular nerve, some afferents have highly irregular interspike intervals and others have highly regular intervals. To investigate whether spike timing is determined by the afferents' ion channels, we studied spiking activity in their cell bodies, isolated from the vestibular ganglia of young rats. Whole cell recordings were made with the perforated-patch method. As previously reported, depolarizing current steps revealed distinct firing patterns. Transient neurons fired on...

Kalluri, Radha; Xue, Jingbing; Eatock, Ruth Anne

2010-01-01

9

Responses of neurons in the caudal medullary lateral tegmental field to visceral inputs and vestibular stimulation in vertical planes.  

Science.gov (United States)

The dorsolateral reticular formation of the caudal medulla, or the lateral tegmental field (LTF), has been classified as the brain's "vomiting center", as well as an important region in regulating sympathetic outflow. We examined the responses of LTF neurons in cats to rotations of the body that activate vestibular receptors, as well as to stimulation of baroreceptors (through mechanical stretch of the carotid sinus) and gastrointestinal receptors (through the intragastric administration of the emetic compound copper sulfate). Approximately half of the LTF neurons exhibited graviceptive responses to vestibular stimulation, similar to primary afferents innervating otolith organs. The other half of the neurons had complex responses, including spatiotemporal convergence behavior, suggesting that they received convergent inputs from a variety of vestibular receptors. Neurons that received gastrointestinal and baroreceptor inputs had similar complex responses to vestibular stimulation; such responses are expected for neurons that contribute to the generation of motion sickness. LTF units with convergent baroreceptor and vestibular inputs may participate in producing the cardiovascular system components of motion sickness, such as the changes in skin blood flow that result in pallor. The administration of copper sulfate often modulated the gain of responses of LTF neurons to vestibular stimulation, particularly for units whose spontaneous firing rate was altered by infusion of drug (median of 459%). The present results raise the prospect that emetic signals from the gastrointestinal tract modify the processing of vestibular inputs by LTF neurons, thereby affecting the probability that vomiting will occur as a consequence of motion sickness. PMID:22955058

Moy, Jennifer D; Miller, Daniel J; Catanzaro, Michael F; Boyle, Bret M; Ogburn, Sarah W; Cotter, Lucy A; Yates, Bill J; McCall, Andrew A

2012-11-01

10

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

Science.gov (United States)

Cochlear implants are currently the most effective solution for profound sensorineural hearing loss, and vestibular prostheses are under development to treat bilateral vestibulopathies. Electrical current spread in these neuroprostheses limits channel independence and, in some cases, may impair their performance. In comparison, optical stimuli that are spatially confined may result in a significant functional improvement. Pulsed infrared radiation (IR) has previously been shown to elicit responses in neurons. This study analyzes the response of neonatal rat spiral and vestibular ganglion neurons in vitro to IR (wavelength = 1,863 nm) using Ca(2+) imaging. Both types of neurons responded consistently with robust intracellular Ca(2+) ([Ca(2+)]i) transients that matched the low-frequency IR pulses applied (4 ms, 0.25-1 pps). Radiant exposures of ?637 mJ/cm(2) resulted in continual neuronal activation. Temperature or [Ca(2+)] variations in the media did not alter the IR-evoked transients, ruling out extracellular Ca(2+) involvement or primary mediation by thermal effects on the plasma membrane. While blockage of Na(+), K(+), and Ca(2+) plasma membrane channels did not alter the IR-evoked response, blocking of mitochondrial Ca(2+) cycling with CGP-37157 or ruthenium red reversibly inhibited the IR-evoked [Ca(2+)]i transients. Additionally, the magnitude of the IR-evoked transients was dependent on ryanodine and cyclopiazonic acid-dependent Ca(2+) release. These results suggest that IR modulation of intracellular calcium cycling contributes to stimulation of spiral and vestibular ganglion neurons. As a whole, the results suggest selective excitation of neurons in the IR beam path and the potential of IR stimulation in future auditory and vestibular prostheses. PMID:24920028

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

2014-09-15

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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

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Interactions between intrinsic membrane and emerging network properties determine signal processing in central vestibular neurons.  

Science.gov (United States)

Head/body motion-related sensory signals are transformed in second-order vestibular neurons (2°VN) into commands for appropriate motor reactions that stabilize gaze and posture during locomotion. In all vertebrates, these neurons form functional subgroups with different membrane properties and response dynamics, compatible with the necessity to process a wide range of motion-related sensory signals. In frog, 2°VN subdivide into two well-defined populations with distinctly different intrinsic membrane properties, discharge dynamics and synaptic response characteristics. Tonic 2°VN form low-pass filters with membrane properties that cause synaptic amplification, whereas phasic 2°VN form band-pass filters that cause shunting of repetitive inputs. The different, yet complementary, filter properties render tonic neurons suitable for integration and phasic neurons for differentiation and event detection. Specific insertion of phasic 2°VN into local vestibular networks of inhibitory interneurons reinforces the functional consequences of the intrinsic membrane properties of this particular cell type with respect to the processing of afferent sensory signals. Thus, the combination of matching intrinsic cellular and emerging network properties generates sets of neuronal elements that form adjustable, frequency-tuned filter components for separate transformation of the various dynamic aspects of head motion-related signals. The overall frequency tuning of central vestibular neurons differs between vertebrates along with variations in species-specific locomotor dynamics, thereby illustrating an ecophysiological plasticity of the involved neuronal elements. Moreover, separation into multiple, dynamically different subtypes at any neuronal level along the vestibulo-motor reflex pathways suggests an organization of head motion-related sensory-motor transformation in parallel, frequency-tuned channels. PMID:21374082

Rössert, C; Straka, H

2011-05-01

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Developmental Expression of Kcnq4 in Vestibular Neurons and Neurosensory Epithelia  

OpenAIRE

Sensory signal transduction of the inner ear afferent neurons and hair cells (HCs) requires numerous ionic conductances. The KCNQ4 voltage-gated M-type potassium channel is thought to set the resting membrane potential in cochlear HCs. Here we describe the spatiotemporal expression patterns of Kcnq4 and the associated alternative splice forms in the HCs of vestibular labyrinth. Whole mount immunodetection, qualitative and quantitative RT-PCR were performed to characterize the expression patte...

Rocha-sanchez, Sonia M. S.; Morris, Kenneth A.; Kachar, Bechara; Nichols, David; Fritzsch, Bernd; Beisel, Kirk W.

2007-01-01

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Three-dimensional analysis of vestibular efferent neurons innervating semicircular canals of the gerbil  

Science.gov (United States)

Anterograde labeling techniques were used to examine peripheral innervation patterns of vestibular efferent neurons in the crista ampullares of the gerbil. Vestibular efferent neurons were labeled by extracellular injections of biocytin or biotinylated dextran amine into the contralateral or ipsilateral dorsal subgroup of efferent cell bodies (group e) located dorsolateral to the facial nerve genu. Anterogradely labeled efferent terminal field varicosities consist mainly of boutons en passant with fewer of the terminal type. The bouton swellings are located predominately in apposition to the basolateral borders of the afferent calyces and type II hair cells, but several boutons were identified close to the hair cell apical border on both types. Three-dimensional reconstruction and morphological analysis of the terminal fields from these cells located in the sensory neuroepithelium of the anterior, horizontal, and posterior cristae were performed. We show that efferent neurons densely innervate each end organ in widespread terminal fields. Subepithelial bifurcations of parent axons were minimal, with extensive collateralization occurring after the axons penetrated the basement membrane of the neuroepithelium. Axonal branching ranged between the 6th and 27th orders and terminal field collecting area far exceeds that of the peripheral terminals of primary afferent neurons. The terminal fields of the efferent neurons display three morphologically heterogeneous types: central, peripheral, and planum. All cell types possess terminal fields displaying a high degree of anisotropy with orientations typically parallel to or within +/-45 degrees of the longitudinal axis if the crista. Terminal fields of the central and planum zones predominately project medially toward the transverse axis from the more laterally located penetration of the basement membrane by the parent axon. Peripheral zone terminal fields extend predominately toward the planum semilunatum. The innervation areas of efferent terminal fields display a trend from smallest to largest for the central, peripheral, and planum types, respectively. Neurons that innervate the central zone of the crista do not extend into the peripheral or planum regions. Conversely, those neurons with terminal fields in the peripheral or planum regions do not innervate the central zone of the sensory neuroepithelium. The central zone of the crista is innervated preferentially by efferent neurons with cell bodies located in the ipsilateral group e. The peripheral and planum zones of the crista are innervated preferentially by efferent neurons with cell bodies located in the contralateral group e. A model incorporating our anatomic observations is presented describing an ipsilateral closed-loop feedback between ipsilateral efferent neurons and the periphery and an open-loop feed-forward innervation from contralateral efferent neurons. A possible role for the vestibular efferent neurons in the modulation of semicircular canal afferent response dynamics is proposed.

Purcell, I. M.; Perachio, A. A.

1997-01-01

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

Directory of Open Access Journals (Sweden)

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.

PaulSmith

2012-02-01

16

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

Science.gov (United States)

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.

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

2000-01-01

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

Directory of Open Access Journals (Sweden)

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.

GayRHolstein

2012-02-01

18

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

Science.gov (United States)

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 sinusoidally modulated 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 threefold 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. PMID:22403566

Holstein, Gay R; Friedrich, Victor L; Martinelli, Giorgio P; Ogorodnikov, Dmitri; Yakushin, Sergei B; Cohen, Bernard

2012-01-01

19

Vestibular Neuronitis  

Science.gov (United States)

... Resources for Help and Information The One-Page Merck Manual of Health Medical Terms Conversion Tables Manuals available ... Labyrinthitis Ear Disorders Caused by Drugs Acoustic Neuroma Merck Manual > Patients & Caregivers > Ear, Nose, and Throat Disorders > Inner ...

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Hypothalamic orexin-A (hypocretin-1) neuronal projections to the vestibular complex and cerebellum in the rat.  

Science.gov (United States)

Immunohistochemistry combined with retrograde tract-tracing techniques were used to investigate the distribution of orexin-A (OX-A)- and OX-A receptor-like (OX1) immunoreactivity within the vestibular complex and cerebellum, and the location of hypothalamic OX-A neurons sending axonal projections to these regions in the Wistar rat. OX-A immunoreactive fibers and presumptive terminals were found throughout the medial (MVe) and lateral (LVe) vestibular nuclei. Light fiber labeling was also observed in the spinal and superior vestibular nuclei. Within the cerebellum, dense fiber and presumptive terminal labeling was observed in the medial cerebellar nucleus (Med; fastigial nucleus), with less dense labeling in the interposed (Int) and lateral cerebellar nuclei (Lat; dentate nucleus). A few scattered OX-A immunoreactive fibers were also observed throughout the cortex of the paraflocculus. OX1-like immunoreactivity was found densely concentrated within LVe, moderate in MVe, and scattered within the spinal and superior vestibular nuclei. Within the cerebellum, OX1-like immunoreactivity was also observed densely within Med and in the dorsolateral aspects of Int. Additionally, OX1 like-labeling was found in Lat, and within the granular layer of the caudal paraflocculus cerebellar cortex. Fluorogold (FG) microinjected into these vestibular and cerebellar regions resulted in retrogradely labeled neurons throughout the ipsilateral hypothalamus. Retrogradely labeled neurons containing OX-A like immunoreactivity were observed dorsal and caudal to the anterior hypothalamic nucleus and extending laterally into the lateral hypothalamic area, with the largest number clustered around the dorsal aspects of the fornix in the perifornical area. A few FG OX-A like-immunoreactive neurons were also observed scattered throughout the dorsomedial, and posterior hypothalamic nuclei. These data indicate that axons from OX-A neurons terminate within the vestibular complex and deep cerebellar nuclei of the cerebellum and although the function of these pathways is unknown, they likely represent pathways by which hypothalamic OX-A containing neurons co-ordinate vestibulo-cerebellar motor and autonomic functions associated with ingestive behaviors. PMID:25017945

Ciriello, John; Caverson, Monica M

2014-09-01

21

Immunohistochemical characterization of neurons in the vestibular ganglion (Scarpa's ganglion) of the pig.  

Science.gov (United States)

The study was carried out on three 4-month old female pigs. All the animals were deeply anesthetized and transcardially perfused with 4% buffered paraformaldehyde (pH 7.4). Vestibular ganglia (VG) were collected and processed for double-labelling immunofluorescence method. The preparations were examined under the Zeiss LSM 710 confocal microscope equipped with adequate filter blocks. Neurons forming VG were round or oval in shape with a round nucleus in the center. The majority of them (58%) were medium (M) (31-50 microm in diameter) while 28 % and 14% were small (S) (up to 30 microm in diameter) or large (L) (above 50 microm in diameter) in size, respectively. Double-labeling immunofluorescence revealed that VG neurons stained for CGRP (approx. 81%; among them 70.5%, 26.2% and 3.3% were M, S and L in size, respectively), VACHT (57%; 63% M, 24% S, 13% L), Met-Enk (25%; 60% M, 12% S, 28% L), VIP (20%; 88% M, 6% S, L), NPY (15%; 67% M, 20% S, 13% L), GAL (15%; 74% M, 21% S, 5% L), SP (12%; 69% M, 25% S, 6% L) and NOS-positive (12%; 50% S, 50% M). The most abundant populations of intraganglionic nerve fibers were those which stained for CGRP or Met-Enk, whereas only single SP- or NOS-positive nerve terminals were observed. PMID:23214371

Dudek, A; Sienkiewicz, W; Kaleczyc, J

2012-01-01

22

Responses of neurons in the caudal medullary lateral tegmental field to visceral inputs and vestibular stimulation in vertical planes  

OpenAIRE

The dorsolateral reticular formation of the caudal medulla, or the lateral tegmental field (LTF), has been classified as the brain's “vomiting center”, as well as an important region in regulating sympathetic outflow. We examined the responses of LTF neurons in cats to rotations of the body that activate vestibular receptors, as well as to stimulation of baroreceptors (through mechanical stretch of the carotid sinus) and gastrointestinal receptors (through the intragastric administration ...

Moy, Jennifer D.; Miller, Daniel J.; Catanzaro, Michael F.; Boyle, Bret M.; Ogburn, Sarah W.; Cotter, Lucy A.; Yates, Bill J.; Mccall, Andrew A.

2012-01-01

23

Chondroitin sulfates in the developing rat hindbrain confine commissural projections of vestibular nuclear neurons  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Establishing correct neuronal circuitry is crucial to proper function of the vertebrate nervous system. The abundance of chondroitin sulfate (CS proteoglycans in embryonic neural environments suggests that matrix proteoglycans regulate axonal projections when fiber tracts have not yet formed. Among the early-born neurons, the vestibular nucleus (VN neurons initiate commissural projections soon after generation at E12.5 and reach the contralateral target by E15.5 in the rat hindbrain. We therefore exploited 24-hour cultures (1 day in vitro (DIV of the rat embryos and chondroitinase ABC treatment of the hindbrain matrix to reveal the role of CS moieties in axonal initiation and projection in the early hindbrain. Results DiI tracing from the VN at E12.5(+1 DIV showed contralaterally projecting fibers assuming fascicles that hardly reached the midline in the controls. In the enzyme-treated embryos, the majority of fibers were unfasciculated as they crossed the midline at 90°. At E13.5(+1 DIV, the commissural projections formed fascicles and crossed the midline in the controls. Enzyme treatment apparently did not affect the pioneer axons that had advanced as thick fascicles normal to the midline and beyond, towards the contralateral VN. Later projections, however, traversed the enzyme-treated matrix as unfasciculated fibers, deviated from the normal course crossing the midline at various angles and extending beyond the contralateral VN. This suggests that CSs also limit the course of the later projections, which otherwise would be attracted to alternative targets. Conclusions CS moieties in the early hindbrain therefore control the course and fasciculation of axonal projections and the timing of axonal arrival at the target.

Kwok Jessica CF

2012-02-01

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Collateral projections from vestibular nuclear and inferior olivary neurons to lobules I/II and IX/X of the rat cerebellar vermis: a double retrograde labeling study.  

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Axon collateral projections to various lobules of the cerebellar cortex are thought to contribute to the coordination of neuronal activities among different parts of the cerebellum. Even though lobules I/II and IX/X of the cerebellar vermis are located at the opposite poles in the anterior-posterior axis, they have been shown to receive dense vestibular mossy fiber projections. For climbing fibers, there is also a mirror-image-like organisation in their axonal collaterals between the anterior and posterior cerebellar cortex. However, the detailed organisation of mossy and climbing fiber collateral afferents to lobules I/II and IX/X is still unclear. Here, we carried out a double-labeling study with two retrograde tracers (FluoroGold and MicroRuby) in lobules I/II and IX/X. We examined labeled cells in the vestibular nuclei and inferior olive. We found a low percentage of double-labeled neurons in the vestibular nuclei (2.1 ± 0.9% of tracer-labeled neurons in this brain region), and a higher percentage of double-labeled neurons in the inferior olive (6.5 ± 1.9%), especially in its four small nuclei (18.5 ± 8.0%; including the ? nucleus, dorsal cap of Kooy, ventrolateral outgrowth, and dorsomedial cell column), which are relevant for vestibular function. These results provide strong anatomical evidence for coordinated information processing in lobules I/II and IX/X for vestibular control. PMID:24964034

Lee, Ray X; Huang, Jian-Jia; Huang, Chiming; Tsai, Meng-Li; Yen, Chen-Tung

2014-09-01

25

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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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.

S.H. Sarkisyan

2012-02-01

26

Implantes vestibulares / Vestibular prosthesis  

Scientific Electronic Library Online (English)

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.

Cristian, Aedo Sánchez; Paul H, Délano Reyes.

2013-12-01

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Neuronal classification and marker gene identification via single-cell expression profiling of brainstem vestibular neurons subserving cerebellar learning  

OpenAIRE

Identification of marker genes expressed in specific cell types is essential for the genetic dissection of neural circuits. Here we report a new strategy for classifying heterogeneous populations of neurons into functionally distinct types and for identifying associated marker genes. Quantitative single-cell expression profiling of genes related to neurotransmitters and ion channels enables functional classification of neurons; transcript profiles for marker gene candidates identify molecular...

Kodama, Takashi; Guerrero, Shiloh; Shin, Minyoung; Moghadam, Seti; Faulstich, Michael; Du Lac, Sascha

2012-01-01

28

Modelling the firing pattern of bullfrog vestibular neurons responding to naturalistic stimuli  

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We have developed a neural system identification method for fitting models to stimulus-response data, where the response is a spike train. The method involves using a general nonlinear optimisation procedure to fit models in the time domain. We have applied the method to model bullfrog semicircular canal afferent neuron responses during naturalistic, broad-band head rotations. These neurons respond in diverse ways, but a simple four parameter class of models elegantly accounts for the various types of responses observed. c1999 Elsevier Science B.V. All rights reserved.

Paulin, M. G.; Hoffman, L. F.

1999-01-01

29

Vestibular blueprint in early vertebrates  

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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.

HansStraka

2013-11-01

30

Fos Expression in Neurons of the Rat Vestibulo-Autonomic Pathway Activated by Sinusoidal Galvanic Vestibular Stimulation  

OpenAIRE

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 sinusoidally modulated 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 thr...

GayRHolstein

2012-01-01

31

Integrative responses of neurons in parabrachial nuclei to a nauseogenic gastrointestinal stimulus and vestibular stimulation in vertical planes  

OpenAIRE

The parabrachial and adjacent Kölliker-Fuse (PBN/KF) nuclei play a key role in relaying visceral afferent inputs to the hypothalamus and limbic system and are, thus, believed to participate in generating nausea and affective responses elicited by gastrointestinal (GI) signals. In addition, the PBN/KF region receives inputs from the vestibular system and likely mediates the malaise associated with motion sickness. However, previous studies have not considered whether GI and vestibular inputs ...

Suzuki, Takeshi; Sugiyama, Yoichiro; Yates, Bill J.

2012-01-01

32

Procedures for restoring vestibular disorders  

OpenAIRE

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 vert...

Walther, Leif Erik

2005-01-01

33

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

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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.

S.H. Sarkisyan

2010-05-01

34

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

OpenAIRE

The mouse has become an important model system for studying the cellular basis of learning and coding of heading by the vestibular system. Here we recorded from single neurons in the vestibular nuclei to understand how vestibular pathways encode self-motion under natural conditions, during which proprioceptive and motor-related signals as well as vestibular inputs provide feedback about an animal's movement through the world. We recorded neuronal responses in alert behaving mice focusing on a...

Medrea, Ioana; Cullen, Kathleen E.

2013-01-01

35

Balance (or Vestibular) Rehabilitation  

Science.gov (United States)

Balance (or Vestibular) Rehabilitation Audiologic (hearing), balance, and medical diagnostic tests help indicate whether you are a candidate for vestibular (balance) rehabilitation. Vestibular rehabilitation is an individualized balance retraining ...

36

Expression of Calcitonin Gene-Related Peptide in Efferent Vestibular System and Vestibular Nucleus in Rats with Motion Sickness  

OpenAIRE

Motion sickness presents a challenge due to its high incidence and unknown pathogenesis although it is a known fact that a functioning vestibular system is essential for the perception of motion sickness. Recent studies show that the efferent vestibular neurons contain calcitonin gene-related peptide (CGRP). It is a possibility that the CGRP immunoreactivity (CGRPi) fibers of the efferent vestibular system modulate primary afferent input into the central nervous system; thus, making it likely...

Xiaocheng, Wang; Zhaohui, Shi; Junhui, Xue; Lei, Zhang; Lining, Feng; Zuoming, Zhang

2012-01-01

37

Procedures for restoring vestibular disorders  

Directory of Open Access Journals (Sweden)

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.

Walther, Leif Erik

2005-09-01

38

Electrical Vestibular Stimulation after Vestibular Deafferentation and in Vestibular Schwannoma  

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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

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

2013-01-01

39

Vestibular Disorders Association  

Science.gov (United States)

... for a vestibular patient, such as the dancing reflection of light below the pool's surface, and how ... Help VEDA collect data on the vestibular patient experience. Together we can advocate for actions that reduce ...

40

Direction specific biases in human visual and vestibular heading perception.  

Science.gov (United States)

Heading direction is determined from visual and vestibular cues. Both sensory modalities have been shown to have better direction discrimination for headings near straight ahead. Previous studies of visual heading estimation have not used the full range of stimuli, and vestibular heading estimation has not previously been reported. The current experiments measure human heading estimation in the horizontal plane to vestibular, visual, and spoken stimuli. The vestibular and visual tasks involved 16 cm of platform or visual motion. The spoken stimulus was a voice command speaking a heading angle. All conditions demonstrated direction dependent biases in perceived headings such that biases increased with headings further from the fore-aft axis. The bias was larger with the visual stimulus when compared with the vestibular stimulus in all 10 subjects. For the visual and vestibular tasks precision was best for headings near fore-aft. The spoken headings had the least bias, and the variation in precision was less dependent on direction. In a separate experiment when headings were limited to ± 45°, the biases were much less, demonstrating the range of headings influences perception. There was a strong and highly significant correlation between the bias curves for visual and spoken stimuli in every subject. The correlation between visual-vestibular and vestibular-spoken biases were weaker but remained significant. The observed biases in both visual and vestibular heading perception qualitatively resembled predictions of a recent population vector decoder model (Gu et al., 2010) based on the known distribution of neuronal sensitivities. PMID:23236490

Crane, Benjamin T

2012-01-01

41

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

Science.gov (United States)

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

Lacour, Michel; Bernard-Demanze, Laurence

2015-01-01

42

ISOLATION AND CHARACTERIZATION OF VESTIBULAR STEM CELLS  

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Full Text Available Introduction The purpose of the ongoing research is to improve our current skills and knowledge in stem cell isolation, cultivation and differentiation from the vestibular epithelia of young mice. Matherials and Methods We harvested utricles and sacculi from 7 days old mice. Obtained cells were cultivated at 37ºC and 5% CO2 in DMEM with F12 Nutrient mixture, B27, N2 supplement, IGF-1 and EGF. Sphere pluripotency was established with Nanog and Oct-4 stem cell markers. We mechanically dissociated primary spheres and cultivated them. Cells were characterized by immunofluorescence and immunohistochemistry for myosinVIIA (hair cell marker, nestin (intermediate filament VI marker and beta III tubulin. Results We proved that vestibular epithelia contains pluripotent stem cells which formed spheres. Sphere-derived cells’ pluripotency was demonstrated by the expression of nanog, oct 4 and nestin markers. We obtained through differentiation different cell types including neuronal cells which were positive for myosin VIIA, nestin, beta III tubulin. We wanted to know the type of neurons and performed Brn3a staining for immature neurons, and  TrKB staining for mature neurons. We cultivated vestibular stem cells on different substrates to observe their behavior. Conclusions Cells obtained from utricular epithelia are pluripotent because they express nanog, oct 4,  nestin, characteristic for cell progenitors and they generate spheres.

Roxana Daniela Vintila

2013-10-01

43

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

OpenAIRE

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 stimul...

Mccall, Andrew A.; Moy, Jennifer D.; Demayo, William M.; Puterbaugh, Sonya R.; Miller, Daniel J.; Catanzaro, Michael F.; Yates, Bill J.

2012-01-01

44

Specific vestibular exercises in the treatment of vestibular neuritis  

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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.

Komazec Zoran

2004-01-01

45

Spatio-temporal diversity in the microenvironments for neural cell adhesion molecule, neural cell adhesion molecule-polysialic acid, and L1-cell adhesion molecule expression by sensory neurons and their targets during cochleo-vestibular innervation.  

Science.gov (United States)

Sixteen phases in the microenvironments were defined for the structural development and innervation of the cochleo-vestibular ganglion and its targets. In each phase the cell adhesion molecules, neural cell adhesion molecule, neural cell adhesion molecule-polysialic acid, and L1-cell adhesion molecule, were expressed differentially by cochleo-vestibular ganglion cells, their precursors, and the target cells on which they synapse. Detected by immunocytochemistry in staged chicken embryos, in the otocyst, neural cell adhesion molecule, but not L1-cell adhesion molecule, was localized to the ganglion and hair cell precursors. Ganglionic precursors, migrating from the otocyst, only weakly expressed neural cell adhesion molecule. Epithelial hair cell precursors, remaining in the otocyst, expressed neural cell adhesion molecule, but not L1-cell adhesion molecule. Post-migratory ganglion cell processes expressed both molecules in all stages. The cell adhesion molecules were most heavily expressed by axons penetrating the otic epithelium and accumulated in large amounts in the basal lamina. In the basilar papilla (cochlea), cell adhesion molecule expression followed the innervation gradient. Neural cell adhesion molecule and L1 were heavily concentrated on axonal endings peripherally and centrally. In the rhombencephalon, primitive epithelial cells expressed neural cell adhesion molecule, but not L1-cell adhesion molecule, except in the floorplate. The neuroblasts and their axons expressed L1-cell adhesion molecule, but not neural cell adhesion molecule, when they began to migrate and form the dorsal commissure. There was a stage-dependent, differential distribution of the cell adhesion molecules in the floorplate. Commissural axons expressed both cell adhesion molecules, but their polysialic acid disappeared within the floorplate at later stages. In conclusion, the cell adhesion molecules are expressed by the same cells at different times and places during their development. They are positioned to play different roles in migration, target penetration, and synapse formation by sensory neurons. A multiphasic model provides a morphological basis for experimental analyses of the molecules critical for the changing roles of the microenvironment in neuronal specification. PMID:9740401

Hrynkow, S H; Morest, D K; Brumwell, C; Rutishauser, U

1998-11-01

46

Vestibular pathways involved in cognition  

OpenAIRE

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...

Martin Hitier

2014-01-01

47

Vestibular evoked myogenic potential in vestibular neuritis.  

Science.gov (United States)

This study wants to show the diagnostic value of vestibular evoked myogenic potential (VEMP) in the diagnosis of vestibular neuritis (VN), independently of the caloric test results. Twenty patients were enrolled with acute vertigo caused by VN. VEMP was tested with the binaural simultaneous stimulation method. Surface electromyographic activity was recorded in the supine patients from symmetrical sites over the upper half of each sternocleidomastoid muscle, with a reference electrode on the lateral end of the upper sternum. During the acute attack, 8 days, 1 month and 3 months after the beginning of the acute attack, all the patients underwent the following examinations: Dix-Hallpike manoeuvre, Pagnini-McClure manoeuvre, head shaking test, pure-tone audiometry, tympanometry, caloric labyrinth stimulation according to the Fitzgerald-Hallpike method and VEMP. At the last visit, the 11 patients diagnosed with superior branch vestibular neuritis did not show any improvement at the caloric labyrinth stimulation and presented VEMP on both sides with normal amplitude and latency; in the 9 cases diagnosed with inferior branch vestibular neuritis, there was an improvement of the VEMP reflex and normal caloric test. Our experience highlights that VEMP recording is applicable for patients with VN as a screening test. PMID:21448610

Nola, Giuseppe; Guastini, Luca; Crippa, Barbara; Deiana, Marco; Mora, Renzo; Ralli, Giovanni

2011-11-01

48

Enlarged Vestibular Aqueducts and Childhood Hearing Loss  

Science.gov (United States)

... Childhood Hearing Loss Enlarged Vestibular Aqueducts and Childhood Hearing Loss On this page: What are vestibular aqueducts? How ... How are enlarged vestibular aqueducts related to childhood hearing loss? Research suggests that most children with enlarged vestibular ...

49

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

Scientific Electronic Library Online (English)

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.

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

2014-09-01

50

Pediatric Vestibular Disorders  

Science.gov (United States)

... enhanced understanding of the interaction within the vestibular-auditory-visual triad. Vital Links. www.VitalLinks.net. Rine ... sensory system effectiveness and maturational changes in postural control in young children. Ped Phys Ther. 1998;10: ...

51

Vestibular function testing.  

LENUS (Irish Health Repository)

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.

Lang, E E

2010-06-01

52

Bilateral vestibular loss.  

Science.gov (United States)

Bilateral vestibular loss is a rare cause of visual disturbance (oscillopsia) and imbalance. When severe, the most common cause is iatrogenic-gentamicin ototoxicity. Bilateral loss is easily diagnosed at the bedside with the dynamic illegible E test. If this test is omitted, it can easily be misdiagnosed as a cerebellar syndrome. Treatment is largely supportive. Care should be taken to avoid medications that suppress vestibular function, and to encourage activity. PMID:24057822

Hain, Timothy C; Cherchi, Marcello; Yacovino, Dario A

2013-07-01

53

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

Science.gov (United States)

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

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

2003-01-01

54

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

Science.gov (United States)

GABA and the GABAA and GABAB receptors play a pivotal role in the coordination of the central vestibular pathways. The commissural inhibition, which exists between the two vestibular nucleus complexes (VNCs) and which is responsible for enhancing the dynamic sensitivity of VNC neurons to head acceleration, is known to be substantially mediated by GABA acting on GABAA and GABAB receptors. After unilateral vestibular deafferentation (UVD), the large asymmetry in spontaneous resting activity between the two VNCs is reinforced and exacerbated by the GABAergic interaction between the ipsilateral and contralateral sides. Although it has been suggested that reduced GABAergic inhibition of the ipsilateral VNC may be partially responsible for the recovery of resting activity that underlies vestibular compensation of the static symptoms of UVD, at present there are few data available to test this hypothesis systematically. There is some evidence that GABA concentrations change in the ipsilateral VNC during the development of compensation; however, it is unclear whether these changes relate to GABA release or to metabolic pools of GABA. Most biochemical studies of GABA receptors have been conducted at the gene expression level. Therefore, it is unclear whether changes in the receptor protein also occur, although the most recent data suggest that changes in GABAA and GABAB receptor density in the VNC are unlikely. The few radioligand binding data relate to GABAA receptors with benzodiazepine binding sites only. A decrease in the sensitivity of ipsilateral VNC neurons from compensated animals to GABA receptor agonists has been reported; however, these studies have employed brainstem slices and therefore the functional identity of the neurons involved has been unclear. Although it seems likely that some changes in central GABAergic systems accompany the recovery of resting activity in the ipsilateral VNC during the development of vestibular compensation, at the present stage there is no compelling evidence that these changes have a causal role in the compensation process. PMID:15713530

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

2005-01-01

55

Vestibular evoked myogenic potential  

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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.

Lemaji?-Komazec Slobodanka

2014-01-01

56

The vestibular implant: Quo vadis?  

OpenAIRE

Abstract Objective: to assess the progress of the development of the vestibular implant and its feasibility short-term. Data sources: a search was performed in Pubmed, Medline and Embase. Key words used were “vestibular prosth*” and “vestibular implant”. The only search limit was language: English or Dutch. Additional sources were medical books, conference lectures and our personal experience with per-operative vestibular stimulation in patients selected for cochlear implantati...

RaymondVan De Berg; NilsGuinand

2011-01-01

57

Inferior vestibular neuritis.  

Science.gov (United States)

Vestibular neuritis (VN) mostly involves the superior portion of the vestibular nerve and labyrinth. This study aimed to describe the clinical features of VN involving the inferior vestibular labyrinth and its afferents only. Of the 703 patients with a diagnosis of VN or labyrinthitis at Seoul National University Bundang Hospital from 2004 to 2010, we retrospectively recruited 9 patients (6 women, age range 15-75) with a diagnosis of isolated inferior VN. Diagnosis of isolated inferior VN was based on torsional downbeating spontaneous nystagmus, abnormal head-impulse test (HIT) for the posterior semicircular canal (PC), and abnormal cervical vestibular-evoked myogenic potentials (VEMP) in the presence of normally functioning horizontal and anterior semicircular canals, as determined by normal HIT and bithermal caloric tests. All patients presented with acute vertigo with nausea, vomiting, and imbalance. Three patients also had tinnitus and hearing loss in the involved side. The rotation axis of torsional downbeating spontaneous nystagmus was best aligned with that of the involved PC. HIT was also positive only for the involved PC. Cervical VEMP was abnormal in seven patients, and ocular VEMP was normal in all four patients tested. Ocular torsion and subjective visual vertical tests were mostly within the normal range. Since isolated inferior VN lacks the typical findings of much more prevalent superior VN, it may be mistaken for a central vestibular disorder. Recognition of this rare disorder may help avoid unnecessary workups in patients with acute vestibulopathy. PMID:22215238

Kim, Ji-Soo; Kim, Hyo Jung

2012-08-01

58

Vestibular evoked myogenic potentials.  

Science.gov (United States)

A pilot study was undertaken in our Vestibular Disorders Clinic to re-evaluate the clinical benefits of vestibular evoked myogenic potentials (VEMP). In seven normal subjects and 20 documented unilateral peripheral vestibular disorder patients, electromyograms were recorded from surface electrodes over the sternomastoid muscles and averaged in response to 0.1-millisecond clicks played through headphones. Control patients demonstrated EMG positive-negative potentials (p14-n21) of equivalent latencies and amplitudes both ipsilateral and contralateral to the stimuli. In patients with documented unilateral peripheral vestibular disorders, the p14-n21 potentials were preserved in the presence of sensorineural hearing loss and absent in those patients with partial or total vestibular loss. A high directional correlation is noted between the p14-n21 potential and gold-standard caloric testing. We suspect the origin of the response may be in the saccule and suggest that VEMP testing may be useful in assessing intact vestibulocollic pathways in humans. PMID:7769642

Robertson, D D; Ireland, D J

1995-02-01

59

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  

OpenAIRE

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 sic...

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

2013-01-01

60

Modulation of memory by vestibular lesions and galvanic vestibular stimulation  

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

PaulSmith

2010-11-01

61

Correlation of Fos expression and circling asymmetry during gerbil vestibular compensation  

Science.gov (United States)

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.

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

1999-01-01

62

Spatial Cognition, Body Representation and Affective Processes: The Role of Vestibular Information beyond Ocular Reflexes and Control of Posture  

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Full Text Available A growing number of studies in humans demonstrate the involvement of vestibular information in tasks that are seemingly remote from well-known functions such as space constancy or postural control. In this review article we point out three emerging streams of research highlighting the importance of vestibular input: 1 Spatial Cognition: Modulation of vestibular signals can induce specific changes in spatial cognitive tasks like mental imagery and the processing of numbers. This has been shown in studies manipulating body orientation (changing the input from the otoliths, body rotation (changing the input from the semicircular canals, in clinical findings with vestibular patients, and in studies carried out in microgravity. There is also an effect in the reverse direction; top-down processes can affect perception of vestibular stimuli. 2 Body Representation: Numerous studies demonstrate that vestibular stimulation changes the representation of body parts, and sensitivity to tactile input or pain. Thus, the vestibular system plays an integral role in multisensory coordination of body representation. 3 Affective Processes and Disorders: Studies in psychiatric patients and patients with a vestibular disorder report a high comorbidity of vestibular dysfunctions and psychiatric symptoms. Recent studies investigated the beneficial effect of vestibular stimulation on psychiatric disorders, and how vestibular input can change mood and affect. These three emerging streams of research in vestibular science are – at least in part – associated with different neuronal core mechanisms. Spatial transformations draw on parietal areas, body representation is associated with somatosensory areas, and affective processes involve insular and cingulate cortices, all of which receive vestibular input. Even though a wide range of different vestibular cortical projection areas has been ascertained, their functionality still is scarcely understood.

Fred W Mast

2014-05-01

63

Vestibular pathways involved in cognition  

Directory of Open Access Journals (Sweden)

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.

Martin Hitier

2014-07-01

64

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

Science.gov (United States)

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

Iwasaki, Shinichi; Yamasoba, Tatsuya

2015-02-01

65

Vestibular involvement in spasmodic torticollis.  

OpenAIRE

Vestibular findings in a group of 35 patients with spasmodic torticollis without other otological or neurological symptoms were reviewed. The most consistent abnormality, present in more than 70% of cases, was a directional preponderance of vestibular nystagmus in the dark in a direction opposite to the head (chin) deviation. Rigidly clamping the head to a rotating chair did not abolish the directional preponderance. In the presence of optic fixation the directional preponderance was less fre...

Bronstein, A. M.; Rudge, P.

1986-01-01

66

Compensation Following Bilateral Vestibular Damage  

OpenAIRE

Bilateral loss of vestibular inputs affects far fewer patients than unilateral inner ear damage, and thus has been understudied. In both animal subjects and human patients, bilateral vestibular hypofunction (BVH) produces a variety of clinical problems, including impaired balance control, inability to maintain stable blood pressure during postural changes, difficulty in visual targeting of images, and disturbances in spatial memory and navigational performance. Experiments in animals have s...

BillJYates

2011-01-01

67

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

Science.gov (United States)

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

Minnigerode, B; Meissner, R

1979-01-01

68

Medial vestibular connections with the hypocretin (orexin) system  

Science.gov (United States)

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

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

2005-01-01

69

Vestibular findings in fibromyalgia patients  

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

Zeigelboim, Bianca Simone

2011-07-01

70

A review of synaptic mechanisms of vestibular efferent signaling in turtles: extrapolation to efferent actions in mammals.  

Science.gov (United States)

The vestibular labyrinth of nearly every vertebrate class receives a prominent efferent innervation that originates in the brainstem and ends as bouton terminals on vestibular hair cells and afferents in each end organ. Although the functional significance of this centrifugal pathway is not well understood, it is clear that efferent neurons, when electrically stimulated under experimental conditions, profoundly impact vestibular afferent discharge. Effects range from chiefly excitation in fish and mammalian vestibular afferents to a more heterogeneous mixture of inhibition and/or excitation in amphibians, reptiles, and birds. What accounts for these diverse response properties? Recent cellular and pharmacological characterization of efferent synaptic mechanisms in turtle offers some insight. In the turtle posterior crista, vestibular efferent neurons are predominantly cholinergic and the effects of efferent stimulation on vestibular afferent discharge can be ascribed to three distinct signaling pathways: (1) Hyperpolarization of type II hair cells mediated by ?9/?10-nAChRs and SK-potassium channels; (2) Depolarization of bouton and calyx afferents via ?4?2*-containing nAChRs; and (3) A slow excitation of calyx afferents attributed to muscarinic AChRs. In this review, we discuss the evidence for these pathways in turtle and speculate on their role in mammalian vestibular efferent actions where synaptic mechanisms are largely unknown. PMID:24177348

Jordan, Paivi M; Parks, Xiaorong Xu; Contini, Donatella; Holt, J Chris

2013-01-01

71

Vestibular control of entorhinal cortex activity in spatial navigation  

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Full Text Available 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 strategy, called path integration, has been shown to involve a network of brain structures. Among these structures, the entorhinal cortex (EC may play a pivotal role as suggested by lesion and electrophysiological data. In particular, it has been recently discovered that some neurons in the medial EC display multiple firing fields producing a regular grid-like pattern across the environment. Such regular activity may arise from the integration of idiothetic information. This hypothesis would be strongly strengthened if it was shown that manipulation of vestibular information interferes with grid cell activity. In the present paper we review neuroanatomical and functional evidence indicating that the vestibular system influences the activity of the brain network involved in spatial navigation. We also provide new data on the effects of reversible inactivation of the peripheral vestibular system on the EC theta rhythm. The main result is that TTX administration abolishes velocity-controlled theta oscillations in the EC, indicating that vestibular information is necessary for EC activity. Since recent data demonstrate that disruption of theta rhythm in the medial EC induces a disorganization of grid cell firing, our findings indicate that the integration of idiothetic information in the EC is essential to form a spatial representation of the environment.

Francesca Sargolini

2014-06-01

72

Ocular Vestibular Evoked Myogenic Potentials  

Scientific Electronic Library Online (English)

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.

Lilian, Felipe; Herman, Kingma.

2014-01-01

73

Compensation following bilateral vestibular damage  

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

BillJYates

2011-12-01

74

The vestibular implant: Quo vadis?  

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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.

RaymondVan De Berg

2011-08-01

75

[Overview: diagnosis of vestibular syndromes].  

Science.gov (United States)

Vestibular syndromes are one of the commonest paroxysmal disorders in our clinical practice. These consist of vertigo, oculomotor abnormalities (nystagmus), postural changes and nausea/vomiting. Vertigo can be classified as real vertigo and dizziness, based upon the presence of clinical rotatory perception. In order to diagnose a responsible lesion for various central and peripheral vestibular syndromes, we have to carefully observe nystagmus in patients with acute vertigo. Gaze-evoked nystagmus is the most important nystagmus in patients with the central vestibular syndromes. The finding is easily found at the bed side examination. In order to keep a velocity-position neural signal such as gaze holding, the neural structure to hold and maintain the neural command for a saccade is hypothesized and this has been called as the brainstem neural integrator, which sends tonic-step commands for eccentric gaze. If this fails then the integrator becomes leaky and the eyes drift back to the central position. This movement necessitates corrective saccades, hence gaze-evoked nystagmus will ensue. Vertical nystagmus such as primary position upbeat or downbeat nystagmus is also seen only in the central vestibular syndromes. The detection and diagnosis of these characteristic nystagmus are essential for primary clinicians who care patients with acute vertigo. PMID:22277489

Hirose, Genjiro

2011-11-01

76

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

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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.

Lacour Michel

2010-12-01

77

Complications of Microsurgery of Vestibular Schwannoma  

OpenAIRE

Background. The aim of this study was to analyze complications of vestibular schwannoma (VS) microsurgery. Material and Methods. A retrospective study was performed in 333 patients with unilateral vestibular schwannoma indicated for surgical treatment between January 1997 and December 2012. Postoperative complications were assessed immediately after VS surgery as well as during outpatient followup. Results. In all 333 patients microsurgical vestibular schwannoma (Koos grade 1: 12, grade 2: 34...

Jan Betka; Ina, Eduard Zv X. B. X.; Zuzana Balogová; Oliver Profant; Ivan, Ji X. Xed Sk X.; Josef Kraus; Xed Lis Xfd, Ji X.; Josef Syka; Martin Chovanec

2014-01-01

78

Visual dependency and dizziness after vestibular neuritis  

OpenAIRE

Symptomatic recovery after acute vestibular neuritis (VN) is variable, with around 50% of patients reporting long term vestibular symptoms; hence, it is essential to identify factors related to poor clinical outcome. Here we investigated whether excessive reliance on visual input for spatial orientation (visual dependence) was associated with long term vestibular symptoms following acute VN. Twenty-eight patients with VN and 25 normal control subjects were included. Patients were enrolled at ...

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

2014-01-01

79

Personality Changes in Patients with Vestibular Dysfunction  

OpenAIRE

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...

PaulSmith

2013-01-01

80

Prosthetic implantation of the human vestibular system  

Science.gov (United States)

Hypothesis A functional vestibular prosthesis can be implanted in human such that electrical stimulation of each semicircular canal produces canal-specific eye movements while preserving vestibular and auditory function. Background A number of vestibular disorders could be treated with prosthetic stimulation of the vestibular end organs. We have previously demonstrated in rhesus monkeys that a vestibular neurostimulator, based on the Nucleus Freedom cochlear implant, can produce canal-specific electrically evoked eye movements while preserving auditory and vestibular function. An investigational device exemption has been obtained from the FDA to study the feasibility of treating uncontrolled Ménière’s disease with the device. Methods The UW/Nucleus vestibular implant was implanted in the perilymphatic space adjacent to the three semicircular canal ampullae of a human subject with uncontrolled Ménière’s disease. Pre and postoperative vestibular and auditory function were assessed. Electrically evoked eye movements were measured at two time points postoperatively. Results Implantation of all semicircular canals was technically feasible. Horizontal canal and auditory function were largely, but not totally, lost. Electrode stimulation in two of three canals resulted in canal-appropriate eye movements. Over time, stimulation thresholds increased. Conclusions Prosthetic implantation of the semicircular canals in humans is technically feasible. Electrical stimulation resulted in canal-specific eye movements, although thresholds increased over time. Preservation of native auditory and vestibular function, previously observed in animals, was not demonstrated in a single subject with advanced Ménière’s disease. PMID:24317220

Golub, Justin S.; Ling, Leo; Nie, Kaibao; Nowack, Amy; Shepherd, Sarah J.; Bierer, Steven M.; Jameyson, Elyse; Kaneko, Chris R. S.; Phillips, James O.; Rubinstein, Jay T.

2015-01-01

81

Swimming behaviour and calcium incorporation into inner ear otoliths of fish after vestibular nerve transection  

Science.gov (United States)

Previous investigations on neonate swordtail fish (Xiphophorus helleri) revealed that otolithic calcium incorporation (visualized using the calcium tracer alizarin complexone) and thus otolith growth had ceased after nerve transection, supporting a hypothesis according to which the gravity-dependent otolith growth is regulated neuronally. Subsequent investigations on larval cichlid fish (Oreochromis mossambicus) yielded contrasting results, repeatedly depending on the particular batch of cichlids investigated. Like most neonate swordtails, Type I cichlids revealed a stop of calcium incorporation after unilateral vestibular nerve transection. Their behaviour after transection was normal, and the otolithic calcium incorporation in controls of the same batch was symmetric. In Type II cichlids, however, vestibular nerve transection had no effect on otolithic calcium incorporation. They behaved kinetotically after transection (this kind of kinetosis was qualitatively similar to the swimming behaviour exhibited by larval cichlids during microgravity in the course of parabolic aircraft flights). The otolithic calcium incorporation in control animals was asymmetric. These results show that the effects of vestibular nerve transection as well as the efficacy of the mechanism, which regulates otolith growth/otolithic calcium incorporation, are - depending on the particular batch of animals - genetically predispositioned. In conclusion, the regulation of otolithic calcium incorporation is guided neuronally, in part via the vestibular nerve and, in part, via a further pathway, which remains to be addressed in the course of future investigations.

Edelmann, E.; Anken, R. H.; Rahmann, H.

2004-01-01

82

Towards a concept of disorders of “higher vestibular function”  

OpenAIRE

Background: Vestibular disorders are commonly characterized by a combination of perceptual, ocular motor, postural, and vegetative manifestations, which cause the symptoms of vertigo, nystagmus, ataxia, and nausea. Multisensory convergence and numerous polysynaptic pathways link the bilaterally organized central vestibular network with limbic, hippocampal, cerebellar, and non-vestibular cortex structures to mediate “higher” cognitive functions. Anatomical classification of vestibular ...

Michael Strupp; Thomas Brandt

2014-01-01

83

Special (vestibular training of servicemen  

Directory of Open Access Journals (Sweden)

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.

Afonin V.M.

2011-02-01

84

Projection neurons of the vestibulo-sympathetic reflex pathway.  

Science.gov (United States)

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

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

2014-06-15

85

Genetic disorders of the vestibular system  

Science.gov (United States)

Purpose of review This review highlights the current body of literature related to the genetics of inherited vestibular disorders and provides a framework for the characterization of these disorders. We emphasize peripheral causes of vestibular dysfunction and highlight recent advances in the field, point out gaps in understanding, and focus on key areas for future investigation. Recent findings The discovery of a modifier gene that leads to a more severe Usher syndrome phenotype calls into question the assumption that Usher syndrome is universally a monogenic disorder. Despite the use of several investigational approaches, the genetic basis of Menière’s disease remains poorly understood. Evidence for a vestibular phenotype associated with DFNB1 suggests that mutations in other genes causally related to nonsyndromic hearing loss also may have an unrecognized vestibular phenotype. Summary Our understanding of the genetic basis for vestibular disorders is superficial. Significant challenges include defining the genetics of inherited isolated vestibular dysfunction and understanding the pathological basis of Menière’s disease. However, improved characterization of inherited vestibular dysfunction, coupled with advanced genetic techniques such as targeted genome capture and massively parallel sequencing, provides an opportunity to investigate these diseases at the genetic level. PMID:21825995

Eppsteiner, Robert W.; Smith, Richard J.H.

2012-01-01

86

Normal and abnormal human vestibular ocular function  

Science.gov (United States)

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

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

1986-01-01

87

[Vestibular schwannoma: a case report of misdiagnosis].  

Science.gov (United States)

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

You, Huizeng; Li, Xiaoying; Wang, Wuqing

2014-11-01

88

STANDARDIZATION OF VESTIBULAR EVOKED MYOGENIC POTENTIALS  

OpenAIRE

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...

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

2009-01-01

89

Vestibular disorders in migrainous children and adolescents  

OpenAIRE

Recurrent vertigo is a special form of migraine in childhood. It is a periodic syndrome of childhood which was previously called migraine equivalent. Thirty young patients (less than 18 years of age) with migraine and vertigo were examined by the authors. The vestibular system of the patients was examined by computer-based electronystagmography. All patients had migraine-related vestibular dysfunction. Most had spontaneous nystagmus and 86.7% had an abnormal bithermal caloric test. Other form...

Szirmai, A?gnes; Farkas, Viktor

2000-01-01

90

Unilateral Vestibular Loss Impairs External Space Representation  

OpenAIRE

The vestibular system is responsible for a wide range of postural and oculomotor functions and maintains an internal, updated representation of the position and movement of the head in space. In this study, we assessed whether unilateral vestibular loss affects external space representation. Patients with Menière's disease and healthy participants were instructed to point to memorized targets in near (peripersonal) and far (extrapersonal) spaces in the absence or presence of a visual backgro...

Borel, Liliane; Redon-zouiteni, Christine; Cauvin, Pierre; Dumitrescu, Michel; Deve?ze, Arnaud; Magnan, Jacques; Pe?ruch, Patrick

2014-01-01

91

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

Scientific Electronic Library Online (English)

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.

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

2007-06-01

92

The developmental segregation of posterior crista and saccular vestibular fibers in mice: a carbocyanine tracer study using confocal microscopy  

Science.gov (United States)

The developmental segregation of gravistatic input mediated by saccular fibers and of angular acceleration input mediated by posterior crista (PC) fibers was analyzed for the first time in a developing mammal using carbocyanine dye tracing in fixed tissue. The data reveal a more extensive projection of either endorgan in 7-day-old mice (P7) than has previously been reported in adult mammals. While we confirm and extend many previous findings, we also describe a novel segregation of saccular and posterior crista fibers in the anterior half of the medial vestibular nucleus (Mv) not reported before. Our developmental analysis shows a progressive segregation of posterior crista and saccular fibers to their respective discrete projection areas between embryonic day 15 (E15) and birth (P0). Retention of overlap in young adult animals appears to reflect the early embryonic overlap found in most areas. The vestibular projection does not show a topological projection as has been described in many other sensory systems. We propose that the unique projection features of the vestibular endorgans may relate to the transformation of vestibular signals into a motor output in the three neuron reflex arc of the VOR, of which the primary vestibular projection constitutes the first leg.

Maklad, Adel; Fritzsch, Bernd

2002-01-01

93

Direction Specific Biases in Human Visual and Vestibular Heading Perception  

OpenAIRE

Heading direction is determined from visual and vestibular cues. Both sensory modalities have been shown to have better direction discrimination for headings near straight ahead. Previous studies of visual heading estimation have not used the full range of stimuli, and vestibular heading estimation has not previously been reported. The current experiments measure human heading estimation in the horizontal plane to vestibular, visual, and spoken stimuli. The vestibular and visual tasks involve...

Crane, Benjamin T.

2012-01-01

94

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)

Full Text Available SciELO Brazil | Languages: English, Portuguese Abstract in portuguese 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

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

2011-03-01

95

Vestibular Schwannoma or acoustic neuroma  

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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.

Hekmatara M

1997-04-01

96

Brainstem processing of vestibular sensory exafference: implications for motion sickness etiology.  

Science.gov (United States)

The origin of the internal "sensory conflict" stimulus causing motion sickness has been debated for more than four decades. Recent studies show a subclass of neurons in the vestibular nuclei and deep cerebellar nuclei that respond preferentially to passive head movements. During active movement, the semicircular canal and otolith input ("reafference") to these neurons are canceled by a mechanism comparing the expected consequences of self-generated movement (estimated with an internal model-presumably located in the cerebellum) with the actual sensory feedback. The un-canceled component ("exafference") resulting from passive movement normally helps compensate for unexpected postural disturbances. Notably, the existence of such vestibular "sensory conflict" neurons had been postulated as early as 1982, but their existence and putative role in posture control and motion sickness have been long debated. Here, we review the development of "sensory conflict" theories in relation to recent evidence for brainstem and cerebellar reafference cancelation, and identify some open research questions. We propose that conditions producing persistent activity of these neurons, or their targets, stimulate nearby brainstem emetic centers-via an as yet unidentified mechanism. We discuss how such a mechanism is consistent with the notable difference in motion sickness susceptibility of drivers as opposed to passengers, human immunity to normal self-generated movement and why head restraint or lying horizontal confers relative immunity. Finally, we propose that fuller characterization of these mechanisms and their potential role in motion sickness could lead to more effective, scientifically based prevention and treatment for motion sickness. PMID:24838552

Oman, Charles M; Cullen, Kathleen E

2014-08-01

97

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Languages: English, Portuguese Abstract in portuguese 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.

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

2009-06-01

98

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

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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.

A.G. Pillay

2000-01-01

99

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

Scientific Electronic Library Online (English)

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.

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

2005-03-01

100

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

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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.

Aline Mizuta Kozoroski Kanashiro

2005-03-01

101

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

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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.

Rocha-Sanchez Sonia M

2010-10-01

102

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

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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.

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

2014-01-01

103

VESTIBULAR NASAL STENOSIS. A clinical case  

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Full Text Available Iatrogenic vestibular stenosis is a blockage of the nasal vestibule caused by adisruption of the vestibular lining with secondary proliferation of fibrous tissue scar and granulation. It is more common as a result of foreign body reaction or nasal trauma. The lesions usually include the lobby and the anterior inferior turbinate. We report the case of a girl of eleven, with a complete and recurrent stenosis of the right nasal vestibule, and whose history was spent in the incubator at birth and feeding tube during this period with repeated aspirations traumatic nostril.

A. Fernández Rodríguez

2010-01-01

104

Physiological principles of vestibular function on earth and in space  

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

Minor, L. B.

1998-01-01

105

Nobel Prize centenary: Robert Bárány and the vestibular system.  

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The hundredth anniversary of Robert Bárány's Nobel Prize in Medicine offers the opportunity to highlight the importance of his discoveries on the physiology and pathophysiology of the vestibular organs. Bárány developed the method of caloric vestibular stimulation that revolutionized the investigation of the semicircular canals and that is still widely used today. Caloric vestibular stimulation launched experimental vestibular research that was relevant to comprehend the evolution of human locomotion, and Bárány's tests continue to be used in neuroscience to understand the influence of vestibular signals on bodily perceptions, cognition and emotions. Only during the last 20 years has caloric vestibular stimulation been merged with brain imaging to localize the human vestibular cortex. PMID:25517362

Lopez, Christophe; Blanke, Olaf

2014-11-01

106

Efficacy of electrotactile vestibular substitution in patients with peripheral and central vestibular loss  

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Vestibular dysfunction of either central or peripheral origin can significantly affect balance, posture, and gait. We conducted a pilot study to test the effectiveness of training with the BrainPort® balance device in subjects with a balance dysfunction due to peripheral or central vestibular loss. The BrainPort® balance device transmits information about the patient’s head position via electrotactile stimulation of the tongue. Head position data is sensed by an accelerometer and displaye...

Danilov, Y. P.; Tyler, M. E.; Skinner, K. L.; Hogle, R. A.; Bach-y-rita, P.

2007-01-01

107

Towards a concept of disorders of “higher vestibular function”  

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Full Text Available Background: Vestibular disorders are commonly characterized by a combination of perceptual, ocular motor, postural, and vegetative manifestations, which cause the symptoms of vertigo, nystagmus, ataxia, and nausea. Multisensory convergence and numerous polysynaptic pathways link the bilaterally organized central vestibular network with limbic, hippocampal, cerebellar, and non-vestibular cortex structures to mediate “higher” cognitive functions. Anatomical classification of vestibular disorders: The traditional classification of vestibular disorders is based on the anatomical site of the lesion. While it distinguishes between the peripheral and the central vestibular systems, certain weaknesses become apparent when applied clinically. There are two reasons for this: first, peripheral and central vestibular disorders cannot always be separated by the clinical syndrome; second, a third category, namely disorders of “higher vestibular function”, is missing. These disorders may be caused by peripheral as well as central vestibular lesions. Functional classification: Here we discuss a new concept of disorders of higher vestibular function which involve cognition and more than one sensory modality. Three conditions are described that exemplify such higher disorders: room tilt illusion, spatial hemineglect, and bilateral vestibulopathy all of which present with deficits of orientation and spatial memory. Conclusions: Further elaboration of such disorders of higher multisensory functions with respect to lesion site and symptomatology is desirable. The room tilt illusion and spatial hemineglect involve vestibular and visual function to the extent that both conditions can be classified as either disorders of higher vestibular or of higher visual functions. A possible way of separating these disorders in a first step is to determine whether the causative lesion site affects the vestibular or the visual system. For the vestibular system this lesion site may be peripheral o

Michael Strupp

2014-06-01

108

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

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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.

Masoud Motasaddi Zarandy

2011-12-01

109

Vesibulotoxicity and Management of Vestibular Disorders  

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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…

Carey, John P.

2005-01-01

110

Response to Vestibular Sensory Events in Autism  

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The purpose of this study was to examine the response to vestibular sensory events in persons with autism. The data for this study was collected as part of a cross-sectional study that examined sensory processing (using the Sensory Profile) in 103 persons with autism, 3-43 years of age, compared to age- and gender-matched community controls. The…

Kern, Janet K.; Garver, Carolyn R.; Grannemann, Bruce D.; Trivedi, Madhukar H.; Carmody, Thomas; Andrews, Alonzo A.; Mehta, Jyutika A.

2007-01-01

111

Vestibular effects on cerebral blood flow  

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Full Text Available Abstract 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 2. 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.

Schlegel Todd T

2009-09-01

112

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

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Full Text Available SciELO Brazil | Languages: English, Portuguese Abstract in portuguese 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.

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

2014-07-01

113

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

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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.

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

2009-06-01

114

Vestibular characterization in the menstrual cycle Caracterização vestibular no ciclo menstrual  

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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.

Cintia Ishii

2009-06-01

115

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  

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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

Alejandro Peña M

2012-04-01

116

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)

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

Alejandro, Peña M.

2012-04-01

117

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

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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

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

2015-01-01

118

Vestibular loss and balance training cause similar changes in human cerebral white matter fractional anisotropy.  

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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

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

2014-01-01

119

Swimming Behavior and Calcium Incorporation into inner Ear Otoliths of Fish after vestibular Nerve Transection  

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Previous investigations on neonate swordtail fish (Xiphophorus helleri) revealed that otolithic calcium incorporation (visualized using the calcium-tracer alizarin- complexone) and thus otolith growth had ceased after nerve transection, supporting a hypothesis according to which the gravity-dependent otolith growth is regulated neuronally. Subsequent investigations on larval cichlid fish (Oreochromis mossambicus) yielded contrasting results, repeatedly depending on the particular batch of cichlids investigated: Like neonate swordtails, type I cichlids revealed a stop of calcium incorporation after unilateral vestibular nerve transection. Their behaviour after transection was normal and the otolithic calcium incorporation in controls of the same batch was symmetrical. In type II cichlids, however, vestibular nerve transection had no effect on otolithic calcium incorporation. They behaved kinetotically after transection (this kind of kinetosis was qualitatively similar to the swimming behaviour exhibited by larval cichlids during microgravity in the course of parabolic aircraft flights). The otolithic calcium incorporation in control animals was asymmetrical. These results stongly suggest that the effects of vestibular nerve transection as well as the efficacy of the mechanism, which regulates otolith growth/otolithic calcium incorporation, are - depending on the particular batch of animals - genetically predispositioned. Thus, it is assumed that the mechanisms regulating otolith growth and equlibibrium differ in the two types of cichlid fish. This work was financially supported by the German Aerospace Center (DLR) e.V. (FKZ: 50 WB 9997).

Edelmann, E.; Anken, R.; Rahmann, H.

120

Galvanic vestibular stimulation impairs cell proliferation and neurogenesis in the rat hippocampus but not spatial memory.  

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Galvanic vestibular stimulation (GVS) is a method of activating the peripheral vestibular system using direct current that is widely employed in clinical neurological testing. Since movement is recognized to stimulate hippocampal neurogenesis and movement is impossible without activation of the vestibular system, we speculated that activating the vestibular system in rats while minimizing movement, by delivering GVS under anesthesia, would affect hippocampal cell proliferation and neurogenesis, and spatial memory. Compared with the sham control group, the number of cells incorporating the DNA replication marker, bromodeoxyuridine (BrdU), was significantly reduced in the bilateral hippocampi in both the cathode left-anode right and cathode right-anode left stimulation groups (P???0.0001). The majority of the BrdU(+ve) cells co-expressed Ki-67, a marker for the S phase of the cell cycle, suggesting that these BrdU(+ve) cells were still in the cell cycle; however, there was no significant difference in the degree of co-labeling between the two stimulation groups. Single labeling for doublecortin (DCX), a marker of immature neurons, showed that while there was no significant difference between the different groups in the number of DCX(+ve) cells in the right dentate gryus, in the left dentate gyrus there was a significant decrease in the cathode left-anode right group compared with the sham controls (P???0.03). Nonetheless, when animals were tested in place recognition, object exploration and Morris water maze tasks, there were no significant differences between the GVS groups and the sham controls. These results suggest that GVS can have striking effects on cell proliferation and possibly neurogenesis in the hippocampus, without affecting spatial memory. PMID:24449222

Zheng, Yiwen; Geddes, Lisa; Sato, Go; Stiles, Lucy; Darlington, Cynthia L; Smith, Paul F

2014-05-01

121

Plasticity during Vestibular Compensation: The Role of Saccades  

OpenAIRE

This paper is focused on one major aspect of compensation: the recent measures of saccadic responses to high acceleration head turns during human vestibular compensation and their possible implications for recovery after unilateral vestibular loss (UVL). New measurement techniques have provided additional 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 periphera...

IanSCurthoys

2012-01-01

122

Linear Path Integration Deficits in Patients with Abnormal Vestibular Afference  

OpenAIRE

Effective navigation requires the ability to keep track of one’s location and maintain orientation during linear and angular displacements. Path integration is the process of updating the representation of body position by integrating internally-generated self-motion signals over time (e.g., walking in the dark). One major source of input to path integration is vestibular afference. We tested patients with reduced vestibular function (unilateral vestibular hypofunction, UVH), patients with ...

Arthur, Joeanna C.; Kortte, Kathleen B.; Shelhamer, Mark; Schubert, Michael C.

2012-01-01

123

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

OpenAIRE

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...

Kingma, Charlotte Mariane

2011-01-01

124

Microsurgical Posterior Fossa Vestibular Neurectomy: An Evolution in Technique  

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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...

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

1991-01-01

125

Retrosigmoid approach for vestibular neurectomy in Meniere's disease  

OpenAIRE

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...

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

2005-01-01

126

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

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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.

Zucca Gianpiero

2009-06-01

127

Hemorrhage into cystic vestibular schwannoma following stereotactic radiation therapy.  

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The occurrence of a hemorrhage into a vestibular schwannoma is a rare phenomenon. Several reports, however, indicate a risk profile for a subgroup of patients with vestibular schwannoma which show hypervascularity in the histopathological examination. Cystic formation, large size, mixed Antoni type and anticoagulation therapy seem to enhance the risk of tumor hemorrhage. We report on a patient with a large cystic vestibular schwannoma who died from fatal bleeding into the tumor 15 months following stereotactic radiation therapy. Since hemorrhage seems to be a relevant risk in large cystic vestibular schwannomas, a surgical treatment should be preferred whenever possible. PMID:18666062

Ganslandt, O; Fahrig, A; Strauss, C

2008-11-01

128

Recurrent Miller Fisher syndrome with vestibular involvement.  

OpenAIRE

We describe a patient who had four relapses of Miller Fisher syndrome over a period of 20 years. The classical triad - ophthalmoparesis, ataxia and areflexia - was present during the first two attacks; ataxia was not observed during the third episode. The final recurrence was characterized by signs suggestive of a central involvement of the oculomotor pathways, subclinical slowing of the visual-evoked potentials, and peripheral vestibular hyporeactivity. Brain imaging was normal, but high lev...

Vermeersch, Gae?tan; Boschi, Antonella; Deggouj, Naima; Pesch, Vincent; Sindic, Christian

2011-01-01

129

Cochlear obliteration after translabyrinthine vestibular schwannoma surgery.  

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The objective of the study was to determine the temporal occurrence of cochlear obliteration following translabyrinthine vestibular schwannoma resection. A retrospective chart review, cross-sectional study, and sequential analysis of the time series were performed. The retrospective study included patients undergoing translabyrinthine resection for stage T1-T2 vestibular schwannoma from 2007 to 2010 without prior therapy and postoperative follow-up including MRI of the brain and the cerebellopontine angle. Already 3 months after surgery a radiographic labyrinthine change was observed in 66.7 %, a partial obstruction in 50 %, and an obstruction limited to the saccule in 16.7 %. Only 33.3 % of the patients showed an unchanged inner ear. In consideration of early cochlear obstruction after translabyrinthine vestibular schwannoma resection, temporary follow-up is necessary. Since the indications for cochlear implantation (CI) have been extended, especially concerning patients with single-side deafness, a simultaneous or early second-stage CI after tumour removal should be discussed. PMID:24414527

Beutner, Caroline; Mathys, Christian; Turowski, Bernd; Schipper, Jörg; Klenzner, Thomas

2015-04-01

130

Allometry in vestibular responses of anurans  

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Frogs and toads turn either their heads or bodies opposite to angular accelerations applied around the yaw axis. Thresholds exist for the minimum angular acceleration that induces this vestibulomotor response in individual frogs. These thresholds were recorded for several anuran species that cover a broad range of sizes and life styles. Interspecific variation in the magnitude of the thresholds, which correlated with the ecology and behavior of the species, was documented. Also an allometric relationship was observed between this threshold and body size; the larger the frog, the lower the threshold. In many species, the threshold value for reflexive vestibulomotor responses to angular acceleration was proportional to the -0.4 (+/-0.2) power of body mass. Physical dimensions of the semicircular canals determine, in part, vestibular sensitivity to angular acceleration. Hence changes with growth in the semicircular canals are believed to contribute to the slope of -0.4. The biological significance of this allometry in vestibular responses is discussed and compared to trends in vestibular sensitivity and semicircular canal morphology of other vertebrate classes.

Yamashita, M.; Naitoh, T.; Kashiwagi, A.; Kondo, Y.; Wassersug, R. J.

1999-01-01

131

Electrical vestibular stimulation and space motion sickness  

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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.

Severac, Alexandra

132

Reabilitação vestibular: utilidade clínica em pacientes com esclerose múltipla / Vestibular rehabilitation: clinical benefits to patients with multiple sclerosis  

Scientific Electronic Library Online (English)

Full Text Available O objetivo desse estudo foi analisar a eficácia do exercício de reabilitação vestibular em dois casos de esclerose múltipla remitente-recorrente. Ambos os casos foram encaminhados do Hospital de Clínicas para o Laboratório de Otoneurologia de uma instituição de ensino e foram submetidos aos seguinte [...] s procedimentos: anamnese, inspeção otológica, avaliação vestibular e aplicação do Dizziness Handicap Inventory pré e pós reabilitação vestibular utilizando-se o protocolo de Cawthorne e Cooksey. No primeiro caso, gênero feminino, 35 anos, tempo de doença de seis anos, referiu tontura há três anos, de intensidade moderada de ocorrência frequente, cefaléia, quedas, desvio de marcha à direita e sensação de desmaio (sic). Apresentou no exame labiríntico, síndrome vestibular periférica deficitária bilateral. No segundo caso, gênero feminino, 49 anos, tempo de doença de dois anos, referiu desvio de marcha à direita, dificuldade e/ou dor ao movimento do pescoço, formigamento de extremidade e alteração vocal. Apresentou no exame labiríntico, síndrome vestibular periférica deficitária à direita. Houve melhora significativa em ambos os casos dos aspectos físico, funcional e emocional do Dizziness Handicap Inventory após a realização da reabilitação vestibular. O protocolo utilizado promoveu melhora na qualidade de vida e auxiliou no processo de compensação vestibular. Abstract in english The aim of the present study was to analyze the effectiveness of vestibular rehabilitation exercises in two cases of remittent-recurrent multiple sclerosis. Both cases were referred from the Clinics Hospital to the Laboratory of Otoneurology of the same institution and were submitted to the followin [...] g procedures: anamnesis, otological inspection, vestibular evaluation, and application of the Dizziness Handicap Inventory before and after vestibular rehabilitation using the Cawthorne and Cooksey protocol. The first case was a 35-year-old female, diagnosed for six years, who referred frequent dizziness of moderate intensity for three years, headaches, falls, deviation of gait to the right and fainting sensations (sic). In the vestibular exam, she presented bilateral peripheral vestibular deficiency syndrome. The second case was a 49-year-old female, diagnosed for two years, who referred deviation of gait to the right, difficulty and/or pain with neck movement, paraesthesia of the extremities and vocal alteration. In the vestibular exam, she presented peripheral vestibular deficiency syndrome to the right. Both cases had significant improvements regarding physical, functional and emotional aspects of the Dizziness Handicap Inventory after vestibular rehabilitation. The protocol used benefitted the subjects' quality of life and favored the process of vestibular compensation.

Bianca Simone, Zeigelboim; Karlin Fabianne, Klagenberg; Paulo Breno Noronha, Liberalesso.

133

Reabilitação vestibular em um hospital universitário / Vestibular rehabilitation in a university hospital  

Scientific Electronic Library Online (English)

Full Text Available A Reabilitação Vestibular visa melhorar o equilíbrio global, a qualidade de vida e orientação espacial dos pacientes com tontura. OBJETIVOS: Traçar o perfil dos pacientes atendidos no Ambulatório de Reabilitação Vestibular do Setor de Otoneurologia de um hospital universitário e verificar os resulta [...] dos obtidos no período de novembro/2000 a dezembro/2004. MATERIAL E MÉTODO: Levantamento de dados contidos nas fichas dos 93 pacientes submetidos à Reabilitação Vestibular no período. FORMA DE ESTUDO: Clínico retrospectivo. RESULTADOS: A média etária dos pacientes foi de 52,82 anos, 56 do sexo feminino e 37 do sexo masculino. O número médio de atendimentos foi 4,3, sendo maior para os pacientes com distúrbios otoneurológicos centrais (média de 5,9). Dentre os pacientes que concluíram o tratamento proposto, 37 (60,7%) obtiveram melhora significativa, 14 (22,9%) tiveram melhora parcial e 10 (16,4%) não referiram benefícios significativos. Os pacientes que mais se beneficiaram com a Reabilitação Vestibular tinham distúrbios otoneurológicos periféricos. CONCLUSÃO: A maior parte dos pacientes era do sexo feminino, com idade média de 52,8 anos. Cinqüenta e um pacientes (83,6%) tiveram benefício com a terapia confirmando a eficácia do tratamento. Abstract in english The aim of vestibular rehabilitation is to improve total balance, quality of life and spatial orientation of patients with dizziness. AIMS: To determine the characteristics of the patients who underwent the Vestibular Rehabilitation program of the Neurotology Ward of a University Hospital, and to ve [...] rify the results obtained between November/2000 and December/2004. MATERIALS AND METHODS: analysis of 93 files from patients under Vestibular Rehabilitation during the studied period. STUDY DESIGN: Retrospective clinical. RESULTS: the mean age of patients was 52.82 years, 56 females and 37 males. The average number of therapy sessions was 4.3, higher for patients with central neurotological disorders (average of 5.9). Among the patients who concluded the treatment, 37 (60.7%) had significant improvement, 14 (22.9%) presented partial improvement and 10 (16.4%) did not report significant benefits. Patients with peripheral neurotological disorders were the ones who most benefited from Vestibular Rehabilitation. CONCLUSION: Most of the patients were female, with a mean age of 52.8 years. Fifty one patients (83.6%) benefited from the therapy, confirming treatment efficacy.

Flávia da Silva, Tavares; Maria Francisca Colella dos, Santos; Keila Alessandra Baraldi, Knobel.

2008-04-01

134

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

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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.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 manifestations, 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.

Renato Cal

2008-08-01

135

Virtual Neuron  

Science.gov (United States)

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.

2009-04-14

136

How can the cochlear implant interfere with the vestibular function?  

OpenAIRE

Introduction: The cochlear implant is a therapeutic option for patients with deep neurosensorial deafness. Some implanted patients evolved with dizziness in the postoperative, which started the interest for the vestibular function. Since then, many studies have reported the association between the cochlear implant and the vestibular dysfunctions.

Abramides, Patricia Arena

2009-01-01

137

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

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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.

Karlstedt Kaj

2004-09-01

138

 A Novel V- Silicone Vestibular Stent: Preventing Vestibular Stenosis andPreserving Nasal Valves  

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Full Text Available  This report presents a novel style of placing nasal stents. Patientsundergoing surgical procedures in the region of nasal vestibuleand nasal valves are at risk of developing vestibular stenosis andlifelong problems with the external and internal nasal valves;sequels of the repair. The objective of the report is to demonstratea simple and successful method of an inverted V- Stent placementto prevent potential complication of vestibular stenosis and nasalvalve compromise later in life. Following a fall on a sharp edge ofa metallic bed, a sixteen month old child with a deep laceratednasal wound extending from the collumellar base toward thetip of the nose underwent surgical exploration and repair of thenasal vestibule and nasal cavity. A soft silicone stent fashioned asinverted V was placed bilaterally. The child made a remarkablerecovery with no evidence of vestibular stenosis or nasal valveabnormalities. In patients with nasal trauma involving the nasalvestibule and internal and external nasal valves stent placementavoids sequels, adhesions, contractures, synechia vestibularstenosis and fibrosis involving these anatomical structures.The advantages of the described V- stents over the traditionalreadymade ridged nasal stents, tubing’s and composite aural graftsare: a technical simplicity of use, b safety, c less morbidity, dmore comfortable, and e economical. To our knowledge, this isthe first report of such a stent for prevention of vestibular stenosisand preserving nasal valves.

Rashid Al Abri

2012-01-01

139

Efficacy of electrotactile vestibular substitution in patients with peripheral and central vestibular loss.  

Science.gov (United States)

Vestibular dysfunction of either central or peripheral origin can significantly affect balance, posture, and gait. We conducted a pilot study to test the effectiveness of training with the BrainPort balance device in subjects with a balance dysfunction due to peripheral or central vestibular loss. The BrainPort balance device transmits information about the patient's head position via electrotactile stimulation of the tongue. Head position data is sensed by an accelerometer and displayed on the tongue as a pattern of stimulation. This pattern of stimulation moves forward, backward, and laterally on the tongue in direct response to head movements. Users of the device were trained to use this stimulation to adjust their position in order to maintain their balance. Twenty-eight subjects with peripheral or central vestibular loss were trained with the BrainPort balance device and tested using the following standardized quantitative measurements of the treatment effects: Computerized Dynamic Posturography (CDP) using the Sensory Organization Test (SOT), Dynamic Gait Index (DGI), Activities-specific Balance Confidence Scale (ABC), and Dizziness Handicap Inventory (DHI). All subjects had chronic balance problems and all but one had previously participated in vestibular rehabilitation therapy. The scores on the clinical tests upon entry into the study were compared to their scores following training with the BrainPort balance device. Our results exhibit consistent positive and statistically significant improvements in balance, posture and gait. These results exceed what could normally be achieved in three to five days of traditional balance training alone. Since this was not a controlled study, we are unable to distinguish the degree to which these improvements are attributable to training with the BrainPort balance device versus the balance exercises performed by all subjects as a part of the BrainPort training sessions. Nonetheless, after training with the BrainPort balance device, all subjects demonstrated significant improvements in performance beyond what might be expected from conventional vestibular rehabilitation therapy. PMID:18413905

Danilov, Y P; Tyler, M E; Skinner, K L; Hogle, R A; Bach-y-Rita, P

2007-01-01

140

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

OpenAIRE

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...

Merfeld, Daniel M.

2011-01-01

141

Identification of Neural Networks That Contribute to Motion Sickness through Principal Components Analysis of Fos Labeling Induced by Galvanic Vestibular Stimulation  

OpenAIRE

Motion sickness is a complex condition that includes both overt signs (e.g., vomiting) and more covert symptoms (e.g., anxiety and foreboding). The neural pathways that mediate these signs and symptoms are yet to identified. This study mapped the distribution of c-fos protein (Fos)-like immunoreactivity elicited during a galvanic vestibular stimulation paradigm that is known to induce motion sickness in felines. A principal components analysis was used to identify networks of neurons activate...

Balaban, Carey D.; Ogburn, Sarah W.; Warshafsky, Susan G.; Ahmed, Abdul; Yates, Bill J.

2014-01-01

142

Nystagmus in enlarged vestibular aqueduct: a case series  

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Full Text Available Enlarged vestibular aqueduct (EVA is one of the commonly identified congenital temporal bone abnormalities associated with sensorineural hearing loss. Hearing loss may be unilateral or bilateral, and typically presents at birth or in early childhood. Vestibular symptoms have been reported in up to 50% of affected individuals, and may be delayed in onset until adulthood. The details of nystagmus in patients with EVA have not been previously reported. The objectives were to describe the clinical history, vestibular test findings and nystagmus seen in a case series of patients with enlarged vestibular aqueduct anomaly. Chart review, included computed tomography temporal bones, infrared nystagmography with positional and positioning testing, caloric testing, rotary chair and vibration testing. Clinical history and nystagmus varied among the five patients in this series. All patients were initially presumed to have benign paroxysmal positional vertigo, but repositioning treatments were not effective, prompting referral, further testing and evaluation. In three patients with longstanding vestibular complaints, positional nystagmus was consistently present. One patient had distinct recurrent severe episodes of positional nystagmus. Nystagmus was unidirectional and horizontal. In one case horizontal nystagmus was consistently reproducible with seated head turn to the affected side, and reached 48 d/s. Nystagmus associated with enlarged vestibular aqueduct is often positional, and can be confused with benign paroxysmal positional vertigo. Unexplained vestibular symptoms in patients with unilateral or bilateral sensorineural hearing loss should prompt diagnostic consideration of EVA.

Judith White

2015-01-01

143

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

Scientific Electronic Library Online (English)

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.

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

144

Avaliação vestibular no tremor essencial Vestibular evaluation in the essential tremor  

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Full Text Available TEMA: o tremor essencial é familial em cerca de 50% dos casos, com uma herança autossômica, possui início insidioso e é lentamente progressivo. PROCEDIMENTOS: avaliou-se no Setor de Otoneurologia de um Hospital Particular em fevereiro de 2007, uma paciente do sexo feminino, branca, 59 anos, casada, artista plástica, com história de tremor na cabeça desde os dois anos de idade (sic. A paciente relata queixa de tontura há vários meses de origem súbita sem acompanhamento de náusea e/ou queda. Nega perda de força muscular e formigamento em membros superiores e inferiores, rebaixamento da acuidade auditiva e zumbido. A paciente relata que um de seus filhos possuiu tremor nas mãos há dois anos e avós maternos e paternos com Parkinson. Realizaram-se os seguintes procedimentos: anamnese, inspeção otológica e avaliação vestibular por meio da vectoeletronistagmografia. RESULTADOS: observaram-se os seguintes achados ao exame vestibular: nistagmo de posicionamento com características centrais, nistagmo espontâneo presente com os olhos abertos, nistagmo semi-espontâneo do tipo múltiplo e hiper-reflexia em valor absoluto à prova calórica 20ºC (OD e OE. CONCLUSÃO: o exame vestibular mostrou-se sensível e importante para captar alterações em provas que sugerissem envolvimento do sistema nervoso central.BACKGROUND: essential tremors are family-related in about 50% of the cases with an autosomal inheritance and they register an insidious beginning with a slow progression. PROCEDURE: a 59 year old, white female patient, married and whose occupation is a plastic artist with a history of head tremors since she was two years (sic old was evaluated in the Otoneurology sector of a private hospital, during the period from February 2007. The patient had been complaining of dizziness from unknown origin for several months without accompanying nausea and/or falls. She denied any loss of muscular strength or tingling in her upper and lower members and neither any lowering of her auditory sharpness nor buzzing. The patient informed that one of her children suffered hand tremors two years ago and also that both grandparents had Parkinson’s disease. The following procedures were performed: anamnesis, otological inspection and vestibular evaluation through vectoelectronystagmography. RESULTS: the following findings from the vestibular exam were observed: positioning nystagmus with central characteristics, spontaneous nystagmus with the eyes open, semi-spontaneous nystagmus of the multiple and hyperreflexia type in readings absolute to the caloric test at 20ºC (RE and LE. CONCLUSION: the vestibular exam was shown to be sensitive and important for garnering alterations in tests that suggested involvement of the central nervous system.

Bianca Simone Zeigelboim

2008-01-01

145

Avaliação vestibular no tremor essencial / Vestibular evaluation in the essential tremor  

Scientific Electronic Library Online (English)

Full Text Available TEMA: o tremor essencial é familial em cerca de 50% dos casos, com uma herança autossômica, possui início insidioso e é lentamente progressivo. PROCEDIMENTOS: avaliou-se no Setor de Otoneurologia de um Hospital Particular em fevereiro de 2007, uma paciente do sexo feminino, branca, 59 anos, casada, [...] artista plástica, com história de tremor na cabeça desde os dois anos de idade (sic). A paciente relata queixa de tontura há vários meses de origem súbita sem acompanhamento de náusea e/ou queda. Nega perda de força muscular e formigamento em membros superiores e inferiores, rebaixamento da acuidade auditiva e zumbido. A paciente relata que um de seus filhos possuiu tremor nas mãos há dois anos e avós maternos e paternos com Parkinson. Realizaram-se os seguintes procedimentos: anamnese, inspeção otológica e avaliação vestibular por meio da vectoeletronistagmografia. RESULTADOS: observaram-se os seguintes achados ao exame vestibular: nistagmo de posicionamento com características centrais, nistagmo espontâneo presente com os olhos abertos, nistagmo semi-espontâneo do tipo múltiplo e hiper-reflexia em valor absoluto à prova calórica 20ºC (OD e OE). CONCLUSÃO: o exame vestibular mostrou-se sensível e importante para captar alterações em provas que sugerissem envolvimento do sistema nervoso central. Abstract in english BACKGROUND: essential tremors are family-related in about 50% of the cases with an autosomal inheritance and they register an insidious beginning with a slow progression. PROCEDURE: a 59 year old, white female patient, married and whose occupation is a plastic artist with a history of head tremors s [...] ince she was two years (sic) old was evaluated in the Otoneurology sector of a private hospital, during the period from February 2007. The patient had been complaining of dizziness from unknown origin for several months without accompanying nausea and/or falls. She denied any loss of muscular strength or tingling in her upper and lower members and neither any lowering of her auditory sharpness nor buzzing. The patient informed that one of her children suffered hand tremors two years ago and also that both grandparents had Parkinson’s disease. The following procedures were performed: anamnesis, otological inspection and vestibular evaluation through vectoelectronystagmography. RESULTS: the following findings from the vestibular exam were observed: positioning nystagmus with central characteristics, spontaneous nystagmus with the eyes open, semi-spontaneous nystagmus of the multiple and hyperreflexia type in readings absolute to the caloric test at 20ºC (RE and LE). CONCLUSION: the vestibular exam was shown to be sensitive and important for garnering alterations in tests that suggested involvement of the central nervous system.

Bianca Simone, Zeigelboim; Cláudia, Mittelmann.

146

STANDARDIZATION OF VESTIBULAR EVOKED MYOGENIC POTENTIALS  

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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.

Ufuk Derinsu

2009-01-01

147

Improving Sensorimotor Function Using Stochastic Vestibular Stimulation  

Science.gov (United States)

Astronauts experience sensorimotor changes during spaceflight, particularly during G-transition phases. Post flight sensorimotor changes may include postural and gait instability, spatial disorientation, and visual performance decrements, all of which can degrade operational capabilities of the astronauts and endanger the crew. Crewmember safety would be improved if these detrimental effects of spaceflight could be mitigated by a sensorimotor countermeasure and even further if adaptation to baseline could be facilitated. The goal of this research is to investigate the potential use of stochastic vestibular stimulation (SVS) as a technology to improve sensorimotor function. We hypothesize that low levels of SVS will improve sensorimotor performance through stochastic resonance (SR). The SR phenomenon occurs when the response of a nonlinear system to a weak input signal is optimized by the application of a particular nonzero level of noise. Two studies have been initiated to investigate the beneficial effects and potential practical usage of SVS. In both studies, electrical vestibular stimulation is applied via electrodes on the mastoid processes using a constant current stimulator. The first study aims to determine the repeatability of the effect of vestibular stimulation on sensorimotor performance and perception in order to better understand the practical use of SVS. The beneficial effect of low levels of SVS on balance performance has been shown in the past. This research uses the same balance task repeated multiple times within a day and across days to study the repeatability of the stimulation effects. The balance test consists of 50 sec trials in which the subject stands with his or her feet together, arms crossed, and eyes closed on compliant foam. Varying levels of SVS, ranging from 0-700 micro A, are applied across different trials. The subject-specific optimal SVS level is that which results in the best balance performance as measured by inertial measurement units placed on the upper and lower torso of the subjects. Additionally, each individual’s threshold for illusory motion perception of suprasensory electrical vestibular stimulation is measured multiple times within and across days to better understand how multiple SVS test methods compare. The second study aims to demonstrate stochastic resonance in the vestibular system using a perception based motion recognition task. This task measures an individual’s velocity threshold of motion recognition using a 6-degree of freedom Stewart platform and a 3-down/1-up staircase procedure. For this study, thresholds are determined using 150 trials in the upright, head-centered roll tilt motion direction at a 0.2 Hz frequency. We aim to demonstrate the characteristic bell shaped curve associated with stochastic resonance with each subject’s motion recognition thresholds at varying SVS levels ranging from 0 to 1500 micro A. The curve includes the individual’s baseline threshold with no SVS, optimal or minimal threshold at some mid-level of SVS, and finally degraded or increased threshold at a high SVS level. An additional aim is to formally retest each subject at his or her individual optimal SVS level on a different day than the original testing for additional validity. The overall purpose of this research is to further quantify the effects of SVS on various sensorimotor tasks and investigate the practical implications of its use in the context of human space flight so that it may be implemented in the future as a component of a comprehensive countermeasure plan for adaptation to G-transitions.

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

2014-01-01

148

Developmental increase in hyperpolarization-activated current regulates intrinsic firing properties in rat vestibular ganglion cells.  

Science.gov (United States)

The primary vestibular neurons convey afferent information from hair cells in the inner ear to the vestibular nuclei and the cerebellum. The intrinsic firing properties of vestibular ganglion cells (VGCs) are heterogeneous to sustained membrane depolarization, and undergo marked developmental changes from phasic to tonic types during the early postnatal period. Previous studies have shown that low-voltage-activated potassium channels, Kv1 and Kv7, play a critical role in determining the firing pattern of VGCs. In the present study, we explored the developmental changes in the properties of hyperpolarization-activated current (Ih) in rat VGCs and the role played by Ih in determining the firing properties of VGCs. Tonic firing VGCs showed a larger current density of Ih as compared to phasic firing VGCs, and tonic firing VGCs became phasic firing in the presence of ZD7288, an Ih channel blocker, indicating that Ih contributes to control the firing pattern of VGCs. The amplitude of Ih increased and the activation kinetics of Ih became faster during the developmental period. Analysis of developmental changes in the expression of hyperpolarization-activated cyclic nucleotide-gated cation (HCN) channels revealed that expression of HCN1 protein and its mRNA increased during the developmental period, whereas expression of HCN2-4 protein and its mRNA did not change. Our results suggest that HCN1 channels as well as Kv1 channels are critical in determining the firing pattern of rat VGCs and that developmental up-regulation of HCN1 transforms VGCs from phasic to tonic firing phenotypes. PMID:25450961

Yoshimoto, R; Iwasaki, S; Takago, H; Nakajima, T; Sahara, Y; Kitamura, K

2015-01-22

149

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Languages: English, Portuguese Abstract in portuguese 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.

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

1443-14-01

150

Reabilitação vestibular em idosos com Parkinson Vestibular rehabilitation in elderly patients with Parkinson  

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Full Text Available OBJETIVO: verificar a efetividade dos exercícios de reabilitação vestibular (RV por meio de avaliação pré e pós-aplicação do questionário Dizziness Handicap Inventory (DHI - adaptação brasileira. MÉTODOS: avaliaram-se oito pacientes (três do sexo feminino e cinco do sexo masculino, na faixa etária de 48 a 71 anos, encaminhados da Associação Paranaense de Parkinson para o Laboratório de Otoneurologia da Universidade Tuiuti do Paraná. Os pacientes foram divididos em dois grupos e submetidos aos seguintes procedimentos: anamnese, avaliação otorrinolaringológica, avaliação vestibular por meio da vectoeletronistagmografia (VENG e aplicação do questionário DHI - adaptação brasileira pré e pós RV utilizando-se os protocolos de Cawthorne e Cooksey (grupo A e Herdman (grupo B. RESULTADOS: a conforme as queixas otoneurológicas referidas na anamnese, observou-se a preval?ncia da tontura (100,0%, tremor (100,0% e desvio de marcha (75,0&; b no exame vestibular, todos os pacientes (100,0% apresentaram alteração, sendo a maior freqüência das síndromes vestibulares periféricas deficitárias (62,5%; c houve melhora significativa dos aspectos funcional (p = 0,020470 e emocional (p = 0,013631 após a realização dos exercícios de RV utilizando-se o protocolo de Cawthorne e Cooksey e do aspecto emocional (p=0,007316 utilizando-se o protocolo de Herdman. CONCLUSÃO: comparando-se os dois protocolos utilizados, verificou-se uma melhora significativa dos pacientes do grupo A, submetidos ao protocolo de Cawthorne e Cooksey (p=0.0231.PURPOSE: to check the effectiveness of vestibular rehabilitation exercises (RV by means of an evaluation of a pre and post application of the Dizziness Handicap Inventory (DHI questionnaire (Brazilian version. METHODS: eight patients were evaluated (three female and five male, in the age group varying from 48 to 71, referred from the Paraná Association of Parkinson to the Otoneurological Laboratory of Tuiuti University of Paraná. The patients were divided in two groups and submitted to the following procedures: anamnesis, otorhinolaryngological evaluation, vestibular evaluation through vectoelectronystagmography (VENG and an application of DHI questionnaire (Brazilian version before and after RV, using Cawthorne and Cooksey (group A and Herdman (group B protocols. RESULTS: a regarding the otoneurological complaints referred to in the anamnesis, the prevalence of dizziness (100.0%, trembling (100.0% and deviation during walking (75.0% were observed; b In the vestibular exam, all patients (100.0% presented alterations, with the largest incidence being the deficient peripheral vestibular syndromes (62.5%; c There was significant improvement of the functional (p = 0,020470 and emotional (p = 0,013631 aspects after accomplishing the RV exercises using the Cawthorne and Cooksey protocol and of the emotional aspect (p=0,007316 using Herdman protocol. CONCLUSION: comparing the two protocols used, a significant improvement of group A patients, submitted to the protocol of Cawthorne and Cooksey (p=0.0231, was confirmed.

Jackeline Martins-Bassetto

2007-06-01

151

Reabilitação vestibular em idosos com Parkinson / Vestibular rehabilitation in elderly patients with Parkinson  

Scientific Electronic Library Online (English)

Full Text Available OBJETIVO: verificar a efetividade dos exercícios de reabilitação vestibular (RV) por meio de avaliação pré e pós-aplicação do questionário Dizziness Handicap Inventory (DHI) - adaptação brasileira. MÉTODOS: avaliaram-se oito pacientes (três do sexo feminino e cinco do sexo masculino), na faixa etári [...] a de 48 a 71 anos, encaminhados da Associação Paranaense de Parkinson para o Laboratório de Otoneurologia da Universidade Tuiuti do Paraná. Os pacientes foram divididos em dois grupos e submetidos aos seguintes procedimentos: anamnese, avaliação otorrinolaringológica, avaliação vestibular por meio da vectoeletronistagmografia (VENG) e aplicação do questionário DHI - adaptação brasileira pré e pós RV utilizando-se os protocolos de Cawthorne e Cooksey (grupo A) e Herdman (grupo B). RESULTADOS: a) conforme as queixas otoneurológicas referidas na anamnese, observou-se a prevalência da tontura (100,0%), tremor (100,0%) e desvio de marcha (75,0&); b) no exame vestibular, todos os pacientes (100,0%) apresentaram alteração, sendo a maior freqüência das síndromes vestibulares periféricas deficitárias (62,5%); c) houve melhora significativa dos aspectos funcional (p = 0,020470) e emocional (p = 0,013631) após a realização dos exercícios de RV utilizando-se o protocolo de Cawthorne e Cooksey e do aspecto emocional (p=0,007316) utilizando-se o protocolo de Herdman. CONCLUSÃO: comparando-se os dois protocolos utilizados, verificou-se uma melhora significativa dos pacientes do grupo A, submetidos ao protocolo de Cawthorne e Cooksey (p=0.0231). Abstract in english PURPOSE: to check the effectiveness of vestibular rehabilitation exercises (RV) by means of an evaluation of a pre and post application of the Dizziness Handicap Inventory (DHI) questionnaire (Brazilian version). METHODS: eight patients were evaluated (three female and five male), in the age group v [...] arying from 48 to 71, referred from the Paraná Association of Parkinson to the Otoneurological Laboratory of Tuiuti University of Paraná. The patients were divided in two groups and submitted to the following procedures: anamnesis, otorhinolaryngological evaluation, vestibular evaluation through vectoelectronystagmography (VENG) and an application of DHI questionnaire (Brazilian version) before and after RV, using Cawthorne and Cooksey (group A) and Herdman (group B) protocols. RESULTS: a) regarding the otoneurological complaints referred to in the anamnesis, the prevalence of dizziness (100.0%), trembling (100.0%) and deviation during walking (75.0%) were observed; b) In the vestibular exam, all patients (100.0%) presented alterations, with the largest incidence being the deficient peripheral vestibular syndromes (62.5%); c) There was significant improvement of the functional (p = 0,020470) and emotional (p = 0,013631) aspects after accomplishing the RV exercises using the Cawthorne and Cooksey protocol and of the emotional aspect (p=0,007316) using Herdman protocol. CONCLUSION: comparing the two protocols used, a significant improvement of group A patients, submitted to the protocol of Cawthorne and Cooksey (p=0.0231), was confirmed.

Jackeline, Martins-Bassetto; Bianca Simone, Zeigelboim; Ari Leon, Jurkiewicz; Angela, Ribas; Marine Raquel Diniz da, Rosa.

2007-06-01

152

Changes in Histamine Receptors (H1, H2, and H3) Expression in Rat Medial Vestibular Nucleus and Flocculus after Unilateral Labyrinthectomy: Histamine Receptors in Vestibular Compensation  

OpenAIRE

Vestibular compensation is the process of behavioral recovery following peripheral vestibular lesion. In clinics, the histaminergic medicine is the most widely prescribed for the treatment of vertigo and motion sickness, however, the molecular mechanisms by which histamine modulates vestibular function remain unclear. During recovery from the lesion, the modulation of histamine receptors in the medial vestibular nucleus (MVN) and the flocculus may play an important role. Here with the means o...

Zhou, Liuqing; Zhou, Wen; Zhang, Sulin; Liu, Bo; Leng, Yangming; Zhou, Renhong; Kong, Weijia

2013-01-01

153

Short-term habituation of eye-movement responses induced by galvanic vestibular stimulation (GVS) in the alert guinea pig.  

Science.gov (United States)

In a recent study, we showed that primary afferent neurons innervating all vestibular end organs were sensitive to galvanic vestibular stimulation (GVS) in guinea pigs. In order to determine the three-dimensional character of eye movements induced by GVS, changes in eye position were recorded using digital video oculography during delivery of bilateral GVS ranging in intensity between 20 and 80 microA. Pulses were delivered in repetitive trains in order to also ascertain the involvement of vestibular habituation. At low intensities of GVS (up to 40 microA), maintained changes in eye position were induced toward the anode and away from the cathode. These eye movements were predominantly vertical with some horizontal eye movement and very little or no torsion. At higher intensities of GVS (>40 microA), horizontal nystagmus was initially observed, as well as an overall deviation of the beating field toward the anode. Nystagmus was found to habituate rapidly over successive presentations of GVS, whereas the tonic deviation of the eye remained consistent without any detectable habituation. The direction of eye movements induced by GVS was similar to that observed in humans during trans-mastoidal GVS, and the threshold differences between tonic and phasic components for GVS were also similar to previous human GVS studies. The observed habituation appears to be more specific to the phasic VOR component in quadrupedal animals such as guinea pigs, and this may reflect a considerable emphasis placed on otolithic stimulation in these animals during complex locomotor activities. PMID:19162141

Kim, Juno

2009-04-01

154

Proton beam stereotactic radiosurgery of vestibular schwannomas  

International Nuclear Information System (INIS)

Purpose: The proton beam's Bragg peak permits highly conformal radiation of skull base tumors. This study, prompted by reports of transient (30% each) and permanent (10% each) facial and trigeminal neuropathy after stereotactic radiosurgery of vestibular schwannomas with marginal doses of 16-20 Gy, assessed whether proton beam radiosurgery using a marginal dose of only 12 Gy could control vestibular schwannomas while causing less neuropathy. Methods and Materials: Sixty-eight patients (mean age 67 years) were treated between 1992 and 1998. The mean tumor volume was 2.49 cm3. The dose to the tumor margin (70% isodose line) was 12 Gy. The prospectively specified follow-up consisted of neurologic evaluation and MRI at 6, 12, 24, and 36 months. Results: After a mean clinical follow-up of 44 months and imaging follow-up of 34 months in 64 patients, 35 tumors (54.7%) were smaller and 25 (39.1%) were unchanged (tumor control rate 94%; actuarial control rate 94% at 2 years and 84% at 5 years). Three tumors enlarged: one shrank after repeated radiosurgery, one remained enlarged at the time of unrelated death, and one had not been imaged for 4 years in a patient who remained asymptomatic at last follow-up. Intratumoral hemorrhage into one stable tumor required craniotomy that proved successful. Thus, 97% of tumors required no additional treatment. Three patients (4.7%) underwent shunting for hydrocephalus evident as increased ataxia. Of 6 patients with functional hea ataxia. Of 6 patients with functional hearing ipsilaterally, 1 improved, 1 was unchanged, and 4 progressively lost hearing. Cranial neuropathies were infrequent: persistent facial hypesthesia (2 new, 1 exacerbated; 4.7%); intermittent facial paresthesias (5 new, 1 exacerbated; 9.4%); persistent facial weakness (2 new, 1 exacerbated; 4.7%) requiring oculoplasty; transient partial facial weakness (5 new, 1 exacerbated; 9.4%), and synkinesis (5 new, 1 exacerbated; 9.4%). Conclusion: Proton beam stereotactic radiosurgery of vestibular schwannomas at the doses used in this study controls tumor growth with relatively few complications

155

Improved results for vestibular schwannoma radiosurgery  

International Nuclear Information System (INIS)

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

156

Implementation of Linear Sensory Signaling via Multiple Coordinated Mechanisms at Central Vestibular Nerve Synapses.  

Science.gov (United States)

Signal transfer in neural circuits is dynamically modified by the recent history of neuronal activity. Short-term plasticity endows synapses with nonlinear transmission properties, yet synapses in sensory and motor circuits are capable of signaling linearly over a wide range of presynaptic firing rates. How do such synapses achieve rate-invariant transmission despite history-dependent nonlinearities? Here, ultrastructural, biophysical, and computational analyses demonstrate that concerted molecular, anatomical, and physiological refinements are required for central vestibular nerve synapses to linearly transmit rate-coded sensory signals. Vestibular synapses operate in a physiological regime of steady-state depression imposed by tonic firing. Rate-invariant transmission relies on brief presynaptic action potentials that delimit calcium influx, large pools of rapidly mobilized vesicles, multiple low-probability release sites, robust postsynaptic receptor sensitivity, and efficient transmitter clearance. Broadband linear synaptic filtering of head motion signals is thus achieved by coordinately tuned synaptic machinery that maintains physiological operation within inherent cell biological limitations. PMID:25704949

McElvain, Lauren E; Faulstich, Michael; Jeanne, James M; Moore, Jeffrey D; du Lac, Sascha

2015-03-01

157

Distinct spontaneous shrinkage of a sporadic vestibular schwannoma  

DEFF Research Database (Denmark)

We present a case with outspoken spontaneous vestibular schwannoma shrinkage and review the related literature. The patient was initially diagnosed with a left-sided, intrameatal vestibular schwannoma, which subsequently grew into the cerebello-pontine angle (CPA), followed by total shrinkage of the CPA component without any intervention over a 12-year observation period. The literature on spontaneous tumor shrinkage was retrieved by searching the subject terms "vestibular schwannoma, conservative management" in PubMed/MEDLINE database, without a time limit. Of the published data, the articles on "shrinkage" or "negative growth" or "regression" or "involution" of the tumor were selected, and the contents on the rate, extent and mechanism of spontaneous tumor shrinkage were extracted and reviewed. The reported rate of spontaneous shrinkage of vestibular schwannoma is 5-10% of patients managed conservatively. Extreme shrinkage of the tumor may occur spontaneously.

Huang, Xiaowen; Cayé-Thomasen, Per

2013-01-01

158

Behavioral assessment of the aging mouse vestibular system.  

Science.gov (United States)

Age related decline in balance performance is associated with deteriorating muscle strength, motor coordination and vestibular function. While a number of studies show changes in balance phenotype with age in rodents, very few isolate the vestibular contribution to balance under either normal conditions or during senescence. We use two standard behavioral tests to characterize the balance performance of mice at defined age points over the lifespan: the rotarod test and the inclined balance beam test. Importantly though, a custom built rotator is also used to stimulate the vestibular system of mice (without inducing overt signs of motion sickness). These two tests have been used to show that changes in vestibular mediated-balance performance are present over the murine lifespan. Preliminary results show that both the rotarod test and the modified balance beam test can be used to identify changes in balance performance during aging as an alternative to more difficult and invasive techniques such as vestibulo-ocular (VOR) measurements. PMID:25045963

Tung, Victoria W K; Burton, Thomas J; Dababneh, Edward; Quail, Stephanie L; Camp, Aaron J

2014-01-01

159

Obstructive sleep apnoea syndrome (OSAS): effects on the vestibular system.  

Science.gov (United States)

Aim of the present study was to evaluate the effects of obstructive sleep apnoea syndrome (OSAS) on the peripheral and central vestibular system, by means of a case series prospective study at the University referral centre of Otolaryngology Head and Neck Surgery; 45 consecutive patients suffering from OSAS were compared with a control group of 30 volunteer subjects selected from among the department employees. Severity of the disease was evaluated by means of cardio-respiratory function monitoring during sleep; the apnoea-hypopnoea index was calculated. Both groups underwent: 1) head and neck examination; 2) fibre-optic examination; 3) pure tone audiometry; 4) evaluation of eye movement disorders using oculomotility tests recorded with the help of video-nystagmography; 5) caloric vestibular responses recorded with video-nystagmography; 6) auditory brainstem response. Results, when evaluating our data, showed that the peripheral vestibular system may become asymmetric due to hypoxic damage while the central vestibular system corrects this disequilibrium. PMID:21808447

Gallina, S; Dispenza, F; Kulamarva, G; Riggio, F; Speciale, R

2010-12-01

160

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

Directory of Open Access Journals (Sweden)

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.

Aracy Pereira Silveira Balbani

2008-02-01

161

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

Scientific Electronic Library Online (English)

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.

Aracy Pereira Silveira, Balbani; Jair Cortez, Montovani.

2008-02-01

162

Bead Neuron  

Science.gov (United States)

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.

Dr. Janet M Dubinsky (University of Minnesota Neuroscience)

2008-11-06

163

Caloric vestibular stimulation in aphasic syndrome  

Directory of Open Access Journals (Sweden)

Full Text Available Caloric vestibular stimulation (CVS is commonly used to diagnose brainstem disorder but its therapeutic application is much less established. Based on the finding that CVS increases blood flow to brain structures associated with language and communication, we assessed whether the procedure has potential to relieve symptoms of post-stroke aphasia. Three participants, each presenting with chronic, unilateral lesions to the left hemisphere, were administered daily CVS for 4 consecutive weeks. Relative to their pre-treatment baseline scores, two of the three participants showed significant improvement on both picture and responsive naming at immediate and one-week follow-up. One of these participants also showed improved sentence repetition, and another showed improved auditory word discrimination. No adverse reactions were reported. These data provide the first, albeit tentative, evidence that CVS may relieve expressive and receptive symptoms of aphasia. A larger, sham-controlled study is now needed to further assess efficacy.

DavidWilkinson

2013-12-01

164

Morphological analysis of the vestibular aqueduct by computerized tomography images  

Energy Technology Data Exchange (ETDEWEB)

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.

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

165

Eye position dependency of nystagmus during constant vestibular stimulation.  

OpenAIRE

Alexander's law, the eye position dependency of nystagmus due to peripheral vestibular lesions, has been hypothesized to occur due to adaptive changes in the brainstem velocity-to-position neural integrator in response to non-reciprocal vestibular stimulation. We investigated whether it develops during passive head rotations that produce constant nystagmus for >35 s. The yaw rotation stimulus consisted of a 1-s acceleration (100°/s(2)), followed by a lower acceleration ramp (starting at 7.3?...

Bockisch, C. J.; Khojasteh, E.; Straumann, D.; Hegemann, S. C. A.

2013-01-01

166

Vestibular activity and cognitive development in children: perspectives  

OpenAIRE

Vestibular signals play an essential role in oculomotor and static and dynamic posturomotor functions. Increasing attention is now focusing on their impact on spatial and non-spatial cognitive functions. Movements of the head in space evoke vestibular signals that make important contributions during the development of brain representations of body parts relative to one another as well as representations of body orientation and position within the environment. A central nervous system pathway ...

SidneyIWiener; DerekA.Hamilton; SylvetteR.Wiener-Vacher

2013-01-01

167

Rizatriptan reduces vestibular-induced motion sickness in migraineurs  

OpenAIRE

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...

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

2010-01-01

168

Mefloquine Damage Vestibular Hair Cells in Organotypic Cultures  

OpenAIRE

Mefloquine is an effective and widely used anti-malarial drug; however, some clinical reports suggest that it can cause dizziness, balance, and vestibular disturbances. To determine if mefloquine might be toxic to the vestibular system, we applied mefloquine to organotypic cultures of the macula of the utricle from postnatal day 3 rats. The macula of the utricle was micro-dissected out as a flat surface preparation and cultured with 10, 50, 100, or 200 ?M mefloquine for 24 h. Specimens were ...

Yu, Dongzhen; Ding, Dalian; Jiang, Haiyan; Stolzberg, Daniel; Salvi, Richard

2010-01-01

169

Postlesional vestibular reorganization improves the gain but impairs the spatial tuning of the maculo-ocular reflex in frogs.  

Science.gov (United States)

The ramus anterior (RA) of N.VIII was sectioned unilaterally. Two months later we analyzed in vivo responses of the ipsi- and of the contralesional abducens nerve during horizontal and vertical linear acceleration in darkness. The contralesional abducens nerve had become responsive again to linear acceleration either because of a synaptic reorganization in the vestibular nuclei on the operated side and/or because of a reinnervation of the utricular macula by regenerating afferent nerve fibers. Significant differences in the onset latencies and in the acceleration sensitivities allowed a separation of RA frogs in a group without and in a group with functional utricular reinnervation. Most important, the vector orientation for maximal abducens nerve responses was clearly altered: postlesional synaptic reorganization resulted in the emergence of abducens nerve responses to vertical linear acceleration, a response component that was barely detectable in RA frogs with utricular reinnervation and that was absent in controls. The ipsilesional abducens nerve, however, exhibited unaltered responses in either group of RA frogs. The altered spatial tuning properties of contralesional abducens nerve responses are a direct consequence of the postlesional expansion of signals from intact afferent nerve and excitatory commissural fibers onto disfacilitated 2nd-order vestibular neurons on the operated side. These results corroborate the notion that postlesional vestibular reorganization activates a basic neural reaction pattern with more beneficial results at the cellular than at the network level. However, given that the underlying mechanism is activity-related, rehabilitative training after vestibular nerve lesion can be expected to shape the ongoing reorganization. PMID:12890798

Rohregger, Martin; Dieringer, Norbert

2003-12-01

170

Analysis of the Baroreceptor and Vestibular Receptor Inputs in the Rostral Ventrolateral Medulla following Hypotension in Conscious Rats.  

Science.gov (United States)

Input signals originating from baroreceptors and vestibular receptors are integrated in the rostral ventrolateral medulla (RVLM) to maintain blood pressure during postural movement. The contribution of baroreceptors and vestibular receptors in the maintenance of blood pressure following hypotension were quantitatively analyzed by measuring phosphorylated extracellular regulated protein kinase (pERK) expression and glutamate release in the RVLM. The expression of pERK and glutamate release in the RVLM were measured in conscious rats that had undergone bilateral labyrinthectomy (BL) and/or sinoaortic denervation (SAD) following hypotension induced by a sodium nitroprusside (SNP) infusion. The expression of pERK was significantly increased in the RVLM in the control group following SNP infusion, and expression peaked 10 min after SNP infusion. The number of pERK positive neurons increased following SNP infusion in BL, SAD, and BL+SAD groups, although the increase was smaller than seen in the control group. The SAD group showed a relatively higher reduction in pERK expression when compared with the BL group. The level of glutamate release was significantly increased in the RVLM in control, BL, SAD groups following SNP infusion, and this peaked 10 min after SNP infusion. The SAD group showed a relatively higher reduction in glutamate release when compared with the BL group. These results suggest that the baroreceptors are more powerful in pERK expression and glutamate release in the RVLM following hypotension than the vestibular receptors, but the vestibular receptors still have an important role in the RVLM. PMID:25729278

Lan, Yan; Lu, Huan-Jun; Jiang, Xian; Li, Li-Wei; Yang, Yan-Zhao; Jin, Guang-Shi; Park, Joo Young; Kim, Min Sun; Park, Byung Rim; Jin, Yuan-Zhe

2015-03-01

171

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Languages: English, Portuguese Abstract in portuguese 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.

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

2005-12-01

172

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

Directory of Open Access Journals (Sweden)

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.

Lilian Felipe

2005-12-01

173

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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.

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

2005-09-01

174

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

Science.gov (United States)

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

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

2015-07-01

175

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)

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.

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

2009-06-01

176

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

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Full Text Available 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 carried 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.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 otorrinolaringológica, 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.

Bianca Simone Zeigelboim

2009-06-01

177

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

Scientific Electronic Library Online (English)

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

Aline Cabral de, Oliveira; José Fernando, Colafêmina; Pedro de Lemos, Menezes.

2011-12-01

178

Role of vestibular information in initiation of rapid postural responses  

Science.gov (United States)

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

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

1998-01-01

179

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)

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.

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

180

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Languages: English, Portuguese Abstract in portuguese 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.

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

2013-06-01

181

Ocular vestibular evoked myogenic potentials in normal-hearing adults  

Directory of Open Access Journals (Sweden)

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.

Mohammad Kamali

2012-06-01

182

Mechanism of spontaneous activity in afferent neurons of the zebrafish lateral-line organ  

OpenAIRE

Many auditory, vestibular, and lateral-line afferent neurons display spontaneous action potentials. This spontaneous spiking is thought to result from hair-cell glutamate release in the absence of stimuli. Spontaneous release at hair-cell resting potentials presumably results from CaV1.3 L-type calcium channel activity. Here, using intact zebrafish larvae, we recorded robust spontaneous spiking from lateral-line afferent neurons in the absence of external stimuli. Consistent with the above as...

Trapani, Josef G.; Nicolson, Teresa

2011-01-01

183

[The vestibular function in patients with various forms of chronic purulent otitis media].  

Science.gov (United States)

A complex vestibulologic examination of 131 patients with otitis media purulenta chronica (OMPC) was made. The patients were divided into groups and subgroups basing on the course of OMPC and presence or absence of subjective vestibular disorders. Vestibular function was assessed in various OMPC forms. Vestibular abnormalities were found in all the examinees. Therefore, all OMPC patients should be examined vestibulologically for early detection of initial, subclinical changes of the inner ear vestibular apparatus and decision on treatment policy. PMID:15699981

Pal'chun, V T; Kunel'skaia, N L; Petlinov, A P

2004-01-01

184

Nitric Oxide Signaling in Hypergravity-Induced Neuronal Plasticity  

Science.gov (United States)

The goal of this research project was to identify the neurons and circuits in the vestibular nuclei and nucleus prepositus hypoglossi that utilize nitric oxide (NO) for intercellular signaling during gravity-induced plasticity. This objective was pursued using histochemical and immunocytochemical approaches to localize NO-producing neurons and characterize the fine morphology of the cells in ground-based studies of normal rats, rats adapted to hypergravity, and rats adapted to hypergravity and then re-adapted to the 1G environment. NO-producing neurons were identified and studied using four methodologies: i) immunocytochemistry employing polyclonal antibodies directed against neuronal nitric oxide synthase (nNOS), to provide an indication of the capacity of a cell for NO production; ii) immunocytochemistry employing a monoclonal antibody directed against L-citrulline, to provide an indirect index of the enzyme's activity; iii) histochemistry based on the NADPH-diaphorase reaction, for fuI1 cytological visualization of neurons; and iv) double immunofluorescence to co-localize nNOS and L-citrulline in individual vestibular nuclei (VN) and neurons.

Holstein, Gay R.

2003-01-01

185

Computerized topographical analysis of functionally homogeneous neuronal sets.  

Science.gov (United States)

A computer-assisted analysis of the spatial distribution of neurons having homogeneous characteristics is described in this paper. The camera lucida drawings of sections of a brain nucleus and the points representing the neurons labeled on the basis of a specific behavior of discharge rates were digitized on a personal computer Amiga 2000 or IBM compatible. Our software provided: a) the computerized, stereotaxically oriented reconstruction of the stored sections and of the plotted neurons; b) the identification within each section of the mass center (MC) of the units sharing a given behavior and of the area where the density of such neurons was maximal (MDA). The routine was tested on the spatial distribution of neuronal responses to serotonin in the lateral vestibular nucleus. PMID:1297363

Giannazzo, E; Licata, F; Li Volsi, G; Mio, G; Santangelo, F; Scivoli, M

1992-11-01

186

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.

187

Bilateral Vestibular Deficiency: Quality of Life and Economic Implications.  

Science.gov (United States)

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

Sun, Daniel Q; Ward, Bryan K; Semenov, Yevgeniy R; Carey, John P; Della Santina, Charles C

2014-04-24

188

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

Science.gov (United States)

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

Dieterich, Marianne; Brandt, Thomas

2015-04-01

189

Binding body and self in visuo-vestibular conflicts.  

Science.gov (United States)

Maintenance of the bodily self relies on the accurate integration of multisensory inputs in which visuo-vestibular cue integration is thought to play an essential role. Here, we tested in healthy volunteers how conflicting visuo-vestibular bodily input might impact on body self-coherence in a full body illusion set-up. Natural passive vestibular stimulation was provided on a motion platform, while visual input was manipulated using virtual reality equipment. Explicit (questionnaire) and implicit (skin temperature) measures were employed to assess illusory self-identification with either a mannequin or a control object. Questionnaire results pointed to a relatively small illusion, but hand skin temperature, plausibly an index of illusory body ownership, showed the predicted drop specifically in the condition when participants saw the mannequin moving in congruence with them. We argue that this implicit measure was accessible to visuo-vestibular modulation of the sense of self, possibly mediated by shared neural processes in the insula involved in vestibular and interoceptive signalling, thermoregulation and multisensory integration. PMID:25557766

Macauda, Gianluca; Bertolini, Giovanni; Palla, Antonella; Straumann, Dominik; Brugger, Peter; Lenggenhager, Bigna

2015-03-01

190

Stereotactic radiation therapy for large vestibular schwannomas  

International Nuclear Information System (INIS)

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

191

Nasal Vestibular Huge Keratoacanthoma: An Unusual Site  

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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.

N. Yazdani

2009-01-01

192

Efficacy of electrotactile vestibular substitution in patients with bilateral vestibular and central balance loss.  

Science.gov (United States)

Patients with bilateral vestibular loss (BVL) of both central and peripheral origin experience multiple problems with balance and posture control, movement, and abnormal gait.Wicab, Inc. has developed the BrainPort balance device to transmit head position/orientation information normally provided by the vestibular system to the brain through a substitute sensory channel: electrotactile stimulation of the tongue. Head-orientation data (artificially sensed) serves as the input signal for the BrainPort balance device to control the movement of a small pattern of stimulation on the tongue that relates to head position in real-time. With training, the brain learns to appropriately interpret the information from the device and utilize it to function as it would with data from a normal-functioning natural sense. Ina total of 40 subjects trained with the BrainPort, 18 have been tested using standardized quantitative measurements of the treatment effects. A specialized set of exercises, testing, and training procedures has been developed that may serve as the course of intensive physical therapy with the BrainPort balance device. Our results demonstrate consistent positive and statistically significant balance rehabilitation effects independent of aging and etiology of balance deficit. PMID:17959464

Danilov, Y P; Tyler, M E; Skinner, K L; Bach-y-Rita, P

2006-01-01

193

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

Scientific Electronic Library Online (English)

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.

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

194

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

Directory of Open Access Journals (Sweden)

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.

Elaine Shizue Novalo

2007-12-01

195

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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.

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

1210-12-01

196

Visual gravitational motion and the vestibular system in humans  

Directory of Open Access Journals (Sweden)

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.

FrancescoLacquaniti

2013-12-01

197

Auditory evoked potentials in peripheral vestibular disorder individuals  

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Full Text Available 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 both 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.

Matas, Carla Gentile

2011-07-01

198

Potenciais evocados auditivos em indivíduos com síndrome vestibular periférica  

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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 comprometer 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.

Carla Gentile Matas1

2011-07-01

199

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

Science.gov (United States)

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

Minnigerode, B

1977-02-01

200

Plasticity during vestibular compensation: the role of saccades  

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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.

IanSCurthoys

2012-02-01

201

A model analysis of static stress in the vestibular membranes  

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Full Text Available Abstract Background The scheme of the core vestibular membranes, consisting of serially connected utricle, ampulla and semicircular canal, first appeared hundreds of millions of years ago in primitive fish and has remained largely unchanged during the subsequent course of evolution. The labyrinths of higher organisms build on this core structure, with the addition of the phylogenetically newer membrane structures, namely, saccule, lagena and cochlea. An analysis of static stress in these core vestibular membranes may contribute to a better understanding of the role of stress in the evolution of derivative membrane structures over the long term as well as the short-term membrane distortions seen in Meniere's disease. Methods A model of these core vestibular membranes is proposed in order to analyze the distribution of stress in the walls of the component chambers. The model uses basic geometrical elements of hollow cylinders and spheres to emulate the actual structures. These model elements lend themselves to a mathematical analysis of static stress in their membranes. Results Hoop stress, akin to the stress in hoops used to reinforce barrel walls, is found to be the predominant stress in the model membranes. The level of hoop stress depends not only on pressure but as well on a geometric stress factor that incorporates membrane shape, thickness and curvature. This result implies that hoop stress may be unevenly distributed in the membranes of the several vestibular chambers due to variations in these dimensional parameters. These results provide a theoretical framework for appraising hoop stress levels in any vestibular labyrinth whose dimensions are known. Conclusion Static hoop stress disparities are likely to exist in the vestibular membranes given their complex physical configurations. Such stress disparities may contribute to the development of membrane pathologies as seen in Meniere's Disease. They may also factor in the evolutionary development of other derivative membrane structures such as the saccule, the lagena, and the cochlea found in higher animals.

Pender Daniel J

2009-09-01

202

Visual and proprioceptive interaction in patients with bilateral vestibular loss  

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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.

Nicholas J. Cutfield

2014-01-01

203

A Stimulator ASIC Featuring Versatile Management for Vestibular Prostheses.  

Science.gov (United States)

This paper presents a multichannel stimulator ASIC for an implantable vestibular prosthesis. The system features versatile stimulation management which allows fine setting of the parameters for biphasic stimulation pulses. To address the problem of charge imbalance due to rounding errors, the digital processor can calculate and provide accurate charge correction. A technique to reduce the data rate to the stimulator is described. The stimulator ASIC was implemented in 0.6-? m high-voltage CMOS technology occupying an area of 2.27 mm(2). The measured performance of the ASIC has been verified using vestibular electrodes in saline. PMID:23851203

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

2011-04-01

204

Multisession stereotactic radiosurgery for large vestibular schwannomas.  

Science.gov (United States)

OBJECT Microsurgery is not the only option for larger vestibular schwannomas (VSs); recent reviews have confirmed the feasibility and efficacy of radiosurgery for larger VSs. This study illustrates the outcomes of a series of large VSs after multisession stereotactic radiosurgery (SRS). METHODS A series of 33 VSs larger than 8 cm(3) (range 8-24 cm(3), mean 11 cm(3), median 9.4 cm(3)) were treated using the CyberKnife from 2003 to 2011 with the multisession SRS technique in 2-5 fractions (14-19.5 Gy). Five patients had undergone surgical removal and 5 had ventriculoperitoneal shunts. Nine patients were eligible for but refused surgery. Twelve patients were older than 70 years and 5 were younger than 40 years. Two female patients had neurofibromatosis. RESULTS The follow-up period ranged from 12 to 111 months (median 48 months); radiological growth control was achieved in 94% of cases: 19 tumors (58%) displayed no size variation or reduction in tumor diameter; 12 (36%), after a transient enlargement, presented with arrested growth or shrinkage. Seven patients had a volume reduction of more than 50%. Two patients (6%) needed debulking and 2 were treated with ventriculoperitoneal shunts. Actuarial progressionfree survival rates at 1 year and 5 years were 97% and 83%, respectively. Hearing was retained in 7 of the 8 patients with serviceable baseline hearing. Adverse events were limited to 1 case each of vertigo, tongue paresthesia, and trigeminal neuralgia. CONCLUSIONS The good control rate obtained with multisession SRS deepens the controversy of the radiobiology of VSs and may extend the indication of radiation therapy (fractionated or SRS) for large VSs to include patients without symptoms of mass effect. The limited number of cases and short follow-up period do not provide sufficient support for widespread application of multisession SRS in young patients. Further studies with multisession SRS are warranted. PMID:25594321

Casentini, Leopoldo; Fornezza, Umberto; Perini, Zeno; Perissinotto, Egle; Colombo, Federico

2015-04-01

205

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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.

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

2011-09-01

206

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)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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

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

2009-06-01

207

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)

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.

Alexandre Secorun Borges

2003-06-01

208

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Languages: English, Portuguese Abstract in portuguese 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.

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

2005-10-01

209

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Languages: English, Portuguese Abstract in portuguese 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.

Marcelo Eiji Inoue, Yamamoto; Cristina Freitas, Ganança.

2012-03-01

210

Stimulus Characteristics for Vestibular Stochastic Resonance to Improve Balance Function  

Science.gov (United States)

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

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

2010-01-01

211

Fractionated stereotactic radiotherapy of vestibular schwannomas accelerates hearing loss  

DEFF Research Database (Denmark)

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.

Rasmussen, Rune; Claesson, Magnus

2012-01-01

212

Development of inner ear afferent connections: forming primary neurons and connecting them to the developing sensory epithelia  

OpenAIRE

The molecular and cellular origin of the primary neurons of the inner ear, the vestibular and spiral neurons, is reviewed including how they connect to the specific sensory epithelia and what the molecular nature of their survival is. Primary neurons of the ear depend on a single basic Helix-Loop-Helix (bHLH) protein for their formation, neurogenin 1 (ngn1). An immediate downstream gene is the bHLH gene neuronal differentiation (NeuroD). Targeted null mutations of ngn1 results in absence of p...

Fritzsch, Bernd

2003-01-01

213

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

Directory of Open Access Journals (Sweden)

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.

AngelicaPerez Fornos

2014-04-01

214

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

Science.gov (United States)

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/rightward); this bidirectional nature of vestibular responses leads to another characteristic-what is sometimes called vestibular bias-that must also be considered, since it can impact threshold measurements, including thresholds found using staircase procedures. This paper develops a basic model of vestibular noise and then analyzes this model for four standard paradigms-one-interval recognition, one-interval detection, two-interval detection, and two-interval recognition. While any of these paradigms might be justified for a specific application, it is concluded that one-interval recognition paradigms have advantages over other paradigms for many vestibular applications. One-interval recognition is favored over one-interval detection because it lends itself to a fixed detection boundary, is more efficient, and is less impacted by device vibration. One-interval recognition is generally favored over two-interval recognition because it assesses vestibular bias and can require substantially less time than two-interval tasks. PMID:21359662

Merfeld, Daniel M

2011-05-01

215

Injections of calmidazolium chloride into the ipsilateral medial vestibular nucleus or fourth ventricle reduce spontaneous ocular nystagmus following unilateral labyrinthectomy in guinea pigs.  

Science.gov (United States)

The effects of three injections (0.5-4.5 h post-operation) of 1-[bis-(p-chlorophenyl)methyl]-3-[2,4-dichloro-beta-(2,4- dichlorobenzyloxy)phenethyl]-imidazolium chloride (calmidazolium chloride, R24571), into the ipsilateral medial vestibular nucleus or fourth ventricle, on vestibular compensation for unilateral labyrinthectomy was studied in guinea pigs. R24571, a calmodulin antagonist and inhibitor of several Ca(2+)-dependent enzymes, caused a significant reduction in the average frequency of spontaneous ocular nystagmus (spontaneous nystagmus) during the first 53 h following unilateral labyrinthectomy (n = 5), compared with vehicle-injected animals (n = 5). Although a statistical analysis was not performed on the yaw head tilt and roll head tilt data because of the large variability between animals over the 53-h period of compensation, most R24571-treated animals had less yaw head tilt (4/4 animals) and roll head tilt (4/5 animals) at 9-11 h post-labyrinthectomy than the average values for the vehicle groups at that time. The decrease in the frequency of spontaneous nystagmus following R24571 treatment was not associated with general ataxia or sedation. These results are consistent with recent biochemical studies in suggesting that intracellular pathways associated with Ca2+ may be involved in the neuronal mechanisms of vestibular compensation following unilateral labyrinthectomy. PMID:8491266

Sansom, A J; Darlington, C L; Smith, P F; Gilchrist, D P; Keenan, C J; Kenyon, R

1993-01-01

216

Integration of vestibular and emetic gastrointestinal signals that produce nausea and vomiting: potential contributions to motion sickness.  

Science.gov (United States)

Vomiting and nausea can be elicited by a variety of stimuli, although there is considerable evidence that the same brainstem areas mediate these responses despite the triggering mechanism. A variety of experimental approaches showed that nucleus tractus solitarius, the dorsolateral reticular formation of the caudal medulla (lateral tegmental field), and the parabrachial nucleus play key roles in integrating signals that trigger nausea and vomiting. These brainstem areas presumably coordinate the contractions of the diaphragm and abdominal muscles that result in vomiting. However, it is unclear whether these regions also mediate the autonomic responses that precede and accompany vomiting, including alterations in gastrointestinal activity, sweating, and changes in blood flow to the skin. Recent studies showed that delivery of an emetic compound to the gastrointestinal system affects the processing of vestibular inputs in the lateral tegmental field and parabrachial nucleus, potentially altering susceptibility for vestibular-elicited vomiting. Findings from these studies suggested that multiple emetic inputs converge on the same brainstem neurons, such that delivery of one emetic stimulus affects the processing of another emetic signal. Despite the advances in understanding the neurobiology of nausea and vomiting, much is left to be learned. Additional neurophysiologic studies, particularly those conducted in conscious animals, will be crucial to discern the integrative processes in the brain stem that result in emesis. PMID:24736862

Yates, Bill J; Catanzaro, Michael F; Miller, Daniel J; McCall, Andrew A

2014-08-01

217

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

OpenAIRE

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

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

2009-01-01

218

Quadratic sinusoidal analysis of voltage clamped neurons.  

Science.gov (United States)

Nonlinear biophysical properties of individual neurons are known to play a major role in the nervous system, especially those active at subthreshold membrane potentials that integrate synaptic inputs during action potential initiation. Previous electrophysiological studies have made use of a piecewise linear characterization of voltage clamped neurons, which consists of a sequence of linear admittances computed at different voltage levels. In this paper, a fundamentally new theory is developed in two stages. First, analytical equations are derived for a multi-sinusoidal voltage clamp of a Hodgkin-Huxley type model to reveal the quadratic response at the ionic channel level. Second, the resulting behavior is generalized to a novel Hermitian neural operator, which uses an algebraic formulation capturing the entire quadratic behavior of a voltage clamped neuron. In addition, this operator can also be used for a nonlinear identification analysis directly applicable to experimental measurements. In this case, a Hermitian matrix of interactions is built with paired frequency probing measurements performed at specific harmonic and interactive output frequencies. More importantly, eigenanalysis of the neural operator provides a concise signature of the voltage dependent conductances determined by their particular distribution on the dendritic and somatic membrane regions of neurons. Finally, the theory is concretely illustrated by an analysis of an experimentally measured vestibular neuron, providing a remarkably compact description of the quadratic responses involved in the nonlinear processing underlying the control of eye position during head rotation, namely the neural integrator. PMID:21499740

Magnani, Christophe; Moore, Lee E

2011-11-01

219

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

Directory of Open Access Journals (Sweden)

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.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.

Eduardo M. Kosugi

2004-12-01

220

Visual-vestibular integration motion perception reporting  

Science.gov (United States)

Self-orientation and self/surround-motion perception derive from a multimodal sensory process that integrates information from the eyes, vestibular apparatus, proprioceptive and somatosensory receptors. Results from short and long duration spaceflight investigations indicate that: (1) perceptual and sensorimotor function was disrupted during the initial exposure to microgravity and gradually improved over hours to days (individuals adapt), (2) the presence and/or absence of information from different sensory modalities differentially affected the perception of orientation, self-motion and surround-motion, (3) perceptual and sensorimotor function was initially disrupted upon return to Earth-normal gravity and gradually recovered to preflight levels (individuals readapt), and (4) the longer the exposure to microgravity, the more complete the adaptation, the more profound the postflight disturbances, and the longer the recovery period to preflight levels. While much has been learned about perceptual and sensorimotor reactions and adaptation to microgravity, there is much remaining to be learned about the mechanisms underlying the adaptive changes, and about how intersensory interactions affect perceptual and sensorimotor function during voluntary movements. During space flight, SMS and perceptual disturbances have led to reductions in performance efficiency and sense of well-being. During entry and immediately after landing, such disturbances could have a serious impact on the ability of the commander to land the Orbiter and on the ability of all crew members to egress from the Orbiter, particularly in a non-nominal condition or following extended stays in microgravity. An understanding of spatial orientation and motion perception is essential for developing countermeasures for Space Motion Sickness (SMS) and perceptual disturbances during spaceflight and upon return to Earth. Countermeasures for optimal performance in flight and a successful return to Earth require the development of preflight and in-flight training to help astronauts acquire and maintain a dual adaptive state. Despite the considerable experience with, and use of, an extensive set of countermeasures in the Russian space program, SMS and perceptual disturbances remain an unresolved problem on long-term flights. Reliable, valid perceptual reports are required to develop and refine stimulus rearrangements presented in the PAT devices currently being developed as countermeasures for the prevention of motion sickness and perceptual disturbances during spaceflight, and to ensure a less hazardous return to Earth. Prior to STS-8, crew member descriptions of their perceptual experiences were, at best, anecdotal. Crew members were not schooled in the physiology or psychology of sensory perception, nor were they exposed to the appropriate professional vocabulary. However, beginning with the STS-8 Shuttle flight, a serious effort was initiated to teach astronauts a systematic method to classify and quantify their perceptual responses in space, during entry, and after flight. Understanding, categorizing, and characterizing perceptual responses to spaceflight has been greatly enhanced by implementation of that training system.

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

1999-01-01

221

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

Directory of Open Access Journals (Sweden)

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.

A.G. Pillay

1999-01-01

222

Galvanic vestibular stimulator for fMRI studies  

Scientific Electronic Library Online (English)

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.

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

223

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

Directory of Open Access Journals (Sweden)

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.

ChristopheLopez

2013-12-01

224

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

Science.gov (United States)

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.

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

225

Effects of vestibular stimulation on spontaneous use of verbal language in developmentally delayed children.  

Science.gov (United States)

The relationship between vestibular stimulation and language development in a group of five primary trainable mentally deficient and five developmentally retarded preschoolers was studied. Subjects received vestibular stimulation prior to a free play situation and were monitored for spontaneous recognizable language use. Results indicated an increase in spontaneous verbal language use for both groups immediately after the stimulation periods, and suggest vestibular stimulation as an effective nonverbal intervention method for the facilitation of spontaneous language. PMID:6971574

Magrun, W M; Ottenbacher, K; McCue, S; Keefe, R

1981-02-01

226

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

OpenAIRE

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 d...

MatteoCandidi; AlessandroMicarelli

2013-01-01

227

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

OpenAIRE

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...

Ekvall-hansson, Eva; Magnusson, Ma?ns

2013-01-01

228

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

OpenAIRE

Introduction: Benign Paroxysmal Positional Vertigo (BPPV) is a very common vestibular disorder characterized by brief but intense attacks of rotatory vertigo triggered by simple rapid movement of the head. The integrity of the vestibular pathways can be assessed using tests such as digital vectoelectronystagmography (VENG) and vestibular evoked myogenic potentials (VEMP). Aim: This study aimed to determine the VEMP findings with respect to latency, amplitude, and waveform peak to peak and the...

Lira-batista, Marta Maria Da Silva; Dorigueto, Ricardo Schaffeln; Gananc?a, Cristina Freitas

2013-01-01

229

Responses of Pigeon Vestibular Hair Cells to Cholinergic Agonists and Antagonists  

OpenAIRE

Acetylcholine (ACh) is the major neurotransmitter released from vestibular efferent terminals onto hair cells and afferents. Previous studies indicate that the two classes of acetylcholine receptors, nicotinic (nAChRs) and muscarinic receptors (mAChRs), are expressed by vestibular hair cells (VHCs). To identify if both classes of receptors are present in VHCs, whole cell, voltage-clamp- and current-clamp- patch recordings were performed on isolated pigeon vestibular type I and type II HCs dur...

Li, Gang Q.; Correia, Manning J.

2010-01-01

230

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

OpenAIRE

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...

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

2012-01-01

231

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

OpenAIRE

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 sterno...

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

2008-01-01

232

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

OpenAIRE

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...

ChristopheLopez

2013-01-01

233

A critical period for the impact of vestibular sensation on ferret motor development  

OpenAIRE

Children with hearing deficits and hypofunctioning vestibular receptors frequently have delayed motor development. This study focuses on when the vestibular system needs to be active for normal motor behavior development and the maturation of the soleus muscle in the ferret. Both vestibular labyrinths were removed from ferrets at Postnatal day 10 (P10), P21, or P45 and the resulting data were compared with ferrets that had undergone a sham surgery at the same ages. The animals were sacrificed...

Cleave, S.; Shall, M. S.

2006-01-01

234

Differential Distribution of Stem Cells in the Auditory and Vestibular Organs of the Inner Ear  

OpenAIRE

The adult mammalian cochlea lacks regenerative capacity, which is the main reason for the permanence of hearing loss. Vestibular organs, in contrast, replace a small number of lost hair cells. The reason for this difference is unknown. In this work we show isolation of sphere-forming stem cells from the early postnatal organ of Corti, vestibular sensory epithelia, the spiral ganglion, and the stria vascularis. Organ of Corti and vestibular sensory epithelial stem cells give rise to cells that...

Oshima, Kazuo; Grimm, Christian M.; Corrales, C. Eduardo; Senn, Pascal; Martinez Monedero, Rodrigo; Ge?le?oc, Gwenae?lle S. G.; Edge, Albert; Holt, Jeffrey R.; Heller, Stefan

2006-01-01

235

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

Directory of Open Access Journals (Sweden)

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.

Anna Paula Batista de Ávila Pires

2013-02-01

236

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)

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.

Carolina R. Resende

2003-08-01

237

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)

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.

Eloisa Sartori, Franco; Ivone, Panhoca.

2007-12-01

238

[Myringoplasty and its effect on a vestibular function in patients with otitis media purulenta chronica (OMPC)].  

Science.gov (United States)

A complex vestibulologic and audiologic examination was made in 25 patients with OMPC free of mesotympanitis before and after experimental myringoplasty with hen's egg amnion. The patients were divided into two groups depending on the presence of vestibular complaints. Partial or complete disappearance of subjective vestibular symptoms, reduced stimulation of the vestibular receptors (by 19%, on the average) were detected by experimental vestibular tests on the side of the affected ear. The asymmetry coefficient by labyrinth lowered by 31.1%, on the average. PMID:16025927

Pal'chun, V T; Kunel'skaia, N L; Mironov, A A; Ganichkina, I Ia; Petlinov, A P

2005-01-01

239

LEITURA DE IMAGENS: A ANÁLISE DE UMA PROVA DE VESTIBULAR  

Directory of Open Access Journals (Sweden)

Full Text Available Com a finalidade de refletir sobre o discurso oficial relacionado à habilidade de leitura de imagem no Ensino Médio, é feita uma análise da prova de vestibular da Universidade Federal de Goiás considerada aqui como a materialização e prática do discurso oficial que possibilita a observação das capacidades e habilidades de leitura. Sendo a linha de pesquisa adotada a Análise do Discurso, alguns conceitos de Foucault, Bakhtin, Maingueneau e outros serão mobilizados. Devido à necessidade de um recorte, o corpus é a prova de vestibular 2011-1. Este trabalho faz parte de uma reflexão maior sobre a leitura, considerando a leitura e interpretação de textos multimodais. Palavras-Chaves: Discurso. Universidade Federal de Goiás. Leitura. Multimodal.

Aline Rezende Belo Alves

2013-10-01

240

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)

241

Magnetic Vestibular Stimulation in Subjects with Unilateral Labyrinthine Disorders  

Directory of Open Access Journals (Sweden)

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.

BryanKevinWard

2014-03-01

242

Should Initial Surveillance of Vestibular Schwannoma Be Abandoned?  

OpenAIRE

Early diagnosis of vestibular schwannoma (VS) has increased in recent years because of increased longevity and availability of magnetic resonance imaging (MRI). Initial conservative radiological surveillance is often requested by patients and physicians to establish whether these tumors are growing before embarking on intervention. Initial observation of at least 1 year in all small VS was therefore recommended by some authors. We evaluated our prospective skull base database of VSs that were...

Eljamel, Sarah; Hussain, Musheer; Eljamel, M. Sam

2011-01-01

243

Image-guided drainage of cystic vestibular schwannomata.  

Science.gov (United States)

The management of vestibular schwannomata is controversial. Surveillance remains an acceptable option for elderly patients or those with small lesions. Stereoradiosurgery is also an option, while surgery is often preferred in younger patients with larger lesions. In elderly patients with lesions causing brainstem compression, craniotomy is a major undertaking. We report two cases of cystic cerebellopontine angle tumours in patients with co-morbidity, who were managed successfully with image-guided insertion of a cystoperitoneal shunt. PMID:19693430

Barrett, Chris; Prasad, K S Manjunath; Hill, John; Johnson, Ian; Heaton, Judith M; Crossman, John E; Mendelow, Alexander D

2010-01-01

244

Vestibular Schwannoma in Patients with Sudden Sensorineural Hearing Loss  

OpenAIRE

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 ...

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

2011-01-01

245

Association between vestibular schwannomas and mobile phone use  

OpenAIRE

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...

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

2013-01-01

246

Pharmacotherapy of vestibular and ocular motor disorders, including nystagmus  

OpenAIRE

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,...

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

2011-01-01

247

Is surgical vestibular ablation necessary in disabling peripheral vertigo?  

OpenAIRE

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 ...

Mahadevaiah, A.; Parikh, Bhavin

2008-01-01

248

Alignment of angular velocity sensors for a vestibular prosthesis  

OpenAIRE

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 r...

DiGiovanna Jack; Carpaneto Jacopo; Micera Silvestro; Merfeld Daniel M

2012-01-01

249

Vestibular control of entorhinal cortex activity in spatial navigation  

OpenAIRE

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 ...

Francesca Sargolini

2014-01-01

250

The sensitivity of an immature vestibular system to altered gravity.  

Science.gov (United States)

Stimulus deprivation or stimulus augmentation can induce long-lasting modifications to sensory and motor systems. If deprivation is effective only during a limited period of life this phase is called "critical period." A critical period was described for the development of the roll-induced vestibuloocular reflex (rVOR) of Xenopus laevis using spaceflights. Spaceflight durations and basic conditions of Xenopus' development did not make it possible to answer the question whether exposure of the immature vestibular organ to weightlessness affects rVOR development. The embryonic development of Pleurodeles waltl is slow enough to solve this problem because the rVOR cannot be induced before 15 dpf. Stage 20-21 embryos (4 dpf) were exposed to microgravity during a 10-day spaceflight, or to 3g hypergravity following the same time schedule. After termination of altered gravity, the rVOR was recorded twice in most animals. The main observations were as follows: (1) after the first rVOR appearance at stage 37 (16 dpf), both rVOR gain and amplitude increased steadily up to saturation levels of 0.22 and 20°, respectively. (2) Three days after termination of microgravity, flight and ground larvae showed no rVOR; 1 day later, the rVOR could be induced only in ground larvae. Differences disappeared after 3 weeks. (3) For 10 days after 3g exposure, rVOR development was similar to that of 1g-controls but 3 weeks later, 3g-larvae showed a larger rVOR than 1g-controls. These observations indicate that the immature vestibular system is transiently sensitive to microgravity exposure and that exposure of the immature vestibular system to hypergravity leads to a slowly growing vestibular sensitization. PMID:22570271

Gabriel, Martin; Frippiat, Jean-Pol; Frey, Herbert; Horn, Eberhard R

2012-07-01

251

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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.

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

2011-06-01

252

Counteracting Muscle Atrophy using Galvanic Stimulation of the Vestibular System  

Science.gov (United States)

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

Fox, Robert A.; Polyakov, Igor

1999-01-01

253

Regional differences in lectin binding patterns of vestibular hair cells  

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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.

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

1994-01-01

254

Glutamic acid decarboxylase 67 expression by a distinct population of mouse vestibular supporting cells.  

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The function of the enzyme glutamate decarboxylase (GAD) is to convert glutamate in ?-aminobutyric acid (GABA). Glutamate decarboxylase exists as two major isoforms, termed GAD65 and GAD67, that are usually expressed in GABA-containing neurons in the central nervous system. GAD65 has been proposed to be associated with GABA exocytosis whereas GAD67 with GABA metabolism. In the present immunofluorescence study, we have investigated the presence of the two GAD isoforms in the semicircular canal cristae of wild type and GAD67-GFP knock-in mice. While no evidence for GAD65 expression was found, GAD67 was detected in a distinct population of peripherally-located supporting cells, but not in hair cells or in centrally-located supporting cells. GABA, on the other hand, was found in all supporting cells. The present result indicate that only a discrete population of supporting cells use GAD67 to synthesize GABA. This is the first report of a marker that allows to distinguish two populations of supporting cells in the vestibular epithelium. On the other hand, the lack of GABA and GAD enzymes in hair cells excludes its involvement in afferent transmission. PMID:25565962

Tavazzani, Elisa; Tritto, Simona; Spaiardi, Paolo; Botta, Laura; Manca, Marco; Prigioni, Ivo; Masetto, Sergio; Russo, Giancarlo

2014-01-01

255

Improving balance function using vestibular stochastic resonance: optimizing stimulus characteristics.  

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Stochastic resonance (SR) is a phenomenon whereby the response of a non-linear system to a weak periodic input signal is optimized by the presence of a particular non-zero level of noise. Stochastic resonance using imperceptible stochastic vestibular electrical stimulation, when applied to normal young and elderly subjects, has been shown to significantly improve ocular stabilization reflexes in response to whole-body tilt; improved balance performance during postural disturbances and optimize covariance between the weak input periodic signals introduced via venous blood pressure receptors and the heart rate responses. In our study, 15 subjects stood on a compliant surface with their eyes closed. They were given low-amplitude binaural bipolar stochastic electrical stimulation of the vestibular organs in two frequency ranges of 1-2 and 0-30 Hz over the amplitude range of 0 to ±700 ?A. Subjects were instructed to maintain an upright stance during 43-s trials, which consisted of baseline (zero amplitude) and stimulation (non-zero amplitude) periods. Measures of stability of the head and trunk using inertial motion unit sensors attached to these segments and the whole body using a force plate were measured and quantified in the mediolateral plane. Using a multivariate optimization criterion, our results show that the low levels of vestibular stimulation given to the vestibular organs improved balance performance in normal healthy subjects in the range of 5-26% consistent with the stochastic resonance phenomenon. In our study, 8 of 15 and 10 of 15 subjects were responsive for the 1-2- and 0-30-Hz stimulus signals, respectively. The improvement in balance performance did not differ significantly between the stimulations in the two frequency ranges. The amplitude of optimal stimulus for improving balance performance was predominantly in the range of ±100 to ±400 ?A. A device based on SR stimulation of the vestibular system might be useful as either a training modality to enhance adaptability or skill acquisition, or as a miniature patch-type stimulator that may be worn by people with disabilities due to aging or disease to improve posture and locomotion function. PMID:21442221

Mulavara, Ajitkumar P; Fiedler, Matthew J; Kofman, Igor S; Wood, Scott J; Serrador, Jorge M; Peters, Brian; Cohen, Helen S; Reschke, Millard F; Bloomberg, Jacob J

2011-04-01

256

Strong galvanic vestibular stimulation obscures arterial pressure response to gravitational change in conscious rats.  

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Galvanic vestibular stimulation (GVS) is known to create an imbalance in the vestibular inputs; thus it is possible that the simultaneously applied GVS obscures adequate gravity-based inputs to the vestibular organs or modifies an input-output relationship of the vestibular system and then impairs the vestibular-mediated response. To examine this, arterial pressure (AP) response to gravitational change was examined in conscious rats with and without GVS. Free drop-induced microgravity and centrifugation-induced hypergravity were employed to elicit vestibular-mediated AP response. GVS itself induced pressor response in an intensity-dependent manner. This pressor response was completely abolished by vestibular lesion, suggesting that the GVS-induced response was mediated by the vestibular system. The pressor response to microgravity (35 +/- 3 mmHg) was significantly reduced by simultaneously applied GVS (19 +/- 1 mmHg), and pressor response to 3-G load was also significantly reduced by GVS. However, GVS had no effect on air jet-induced pressor response. The effects of GVS on pressor response to gravitational change were qualitatively and quantitatively similar to that caused by the vestibular lesion, effects of which were demonstrated in our previous studies (Gotoh TM, Fujiki N, Matsuda T, Gao S, Morita H. Am J Physiol Regul Integr Comp Physiol 286: R25-R30, 2004; Matsuda T, Gotoh TM, Tanaka K, Gao S, Morita H. Brain Res 1028: 140-147, 2004; Tanaka K, Gotoh TM, Awazu C, Morita H. Neurosci Lett 397: 40-43, 2006). These results indicate that GVS reduced the vestibular-mediated pressor response to gravitational change but has no effect on the non-vestibular-mediated pressor response. Thus GVS might be employed for the acute interruption of the AP response to gravitational change. PMID:17916676

Abe, Chikara; Tanaka, Kunihiko; Awazu, Chihiro; Morita, Hironobu

2008-01-01

257

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)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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.

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

2003-08-01

258

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)

Full Text Available SciELO Brazil | Languages: English, Portuguese Abstract in portuguese 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.

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

2013-08-01

259

Effects of weightlessness on the development of the vestibular apparatus and ocular nystagmus in the rat  

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The chronic 2g centrifuge was constructed for testing weightlessness effects on development of vestibular apparatus and ocular nystagmus in the rat. Both the stationary and rotating rail tests were performed. A physiological review is presented on vestibular apparatus, along with a system analysis. Time constants and input threshold level of the system are also considered.

Clark, D. L.

1972-01-01

260

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

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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.

MatteoCandidi

2013-11-01

261

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

Science.gov (United States)

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. PMID:24324422

Candidi, Matteo; Micarelli, Alessandro; Viziano, Andrea; Aglioti, Salvatore M.; Minio-Paluello, Ilaria; Alessandrini, Marco

2013-01-01

262

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

Science.gov (United States)

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

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

2015-01-01

263

The central vestibular complex in dolphins and humans: functional implications of Deiters' nucleus.  

Science.gov (United States)

Toothed whales (Odontocetes; e.g., dolphins) are well-known for efficient underwater locomotion and for their acrobatic capabilities. Nevertheless, in relation to other mammals including the human and with respect to body size, their vestibular apparatus is reduced, particularly the semicircular canals. Concomitantly, the vestibular nerve and most of the vestibular nuclei are thin and small, respectively, in comparison with those in terrestrial mammals. In contrast, the lateral (Deiters') vestibular nucleus is comparatively well developed in both coastal and pelagic dolphins. In the La Plata dolphin (Pontoporia blainvillei) and the Common dolphin (Delphinus delphis), all of the vestibular nuclei are present and their topographic relations are similar to those in humans. Quantitative analysis, however, revealed that in the dolphin most of the nuclei (superior, medial, descending nucleus) are minute both in absolute and relative terms. Here, the only exception is the lateral vestibular nucleus, which is of comparable size in humans and Pontoporia and decidedly more voluminous in Delphinus. While the small size of the majority of the dolphin's vestibular nuclei correlates well with miniaturization of the semicircular canals, the size of Deiters' nucleus seems to support its relative independence from the vestibular system and a close functional relationship with the cerebellum. In comparison with findings in humans and other terrestrial mammals, both of these aspects seem to be related to the physical conditions of aquatic life and locomotion in three dimensions. PMID:19390175

Kern, A; Seidel, K; Oelschläger, H H A

2009-01-01

264

Navigational path integration by cortical neurons: origins in higher-order direction selectivity.  

Science.gov (United States)

Navigation relies on the neural processing of sensory cues about observer self-movement and spatial location. Neurons in macaque dorsal medial superior temporal cortex (MSTd) respond to visual and vestibular self-movement cues, potentially contributing to navigation and orientation. We moved monkeys on circular paths around a room while recording the activity of MSTd neurons. MSTd neurons show a variety of sensitivities to the monkey's heading direction, circular path through the room, and place in the room. Changing visual cues alters the relative prevalence of those response properties. Disrupting the continuity of self-movement paths through the environment disrupts path selectivity in a manner linked to the time course of single neuron responses. We hypothesize that sensory cues interact with the spatial and temporal integrative properties of MSTd neurons to derive path selectivity for navigational path integration supporting spatial orientation. PMID:25589586

Page, William K; Sato, Nobuya; Froehler, Michael T; Vaughn, William; Duffy, Charles J

2015-03-15

265

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

Scientific Electronic Library Online (English)

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.

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

2008-12-01

266

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

Science.gov (United States)

The basic connectivity from the vestibular labyrinth to the eye muscles (vestibular ocular reflex, VOR) has been elucidated in the past decade, and we summarise this in graphic format. We also review the concept of 'velocity storage', a brainstem integrator that prolongs vestibular responses. Finally, we present new discoveries of how complex visual stimuli, such as binocular rivalry, influence VOR processing. In contrast to the basic brainstem circuits, cortical vestibular circuits are far from being understood, but parietal-vestibular nuclei projections are likely to be involved. PMID:25412719

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

2015-02-01

267

Neuronal Migration Disorders  

Science.gov (United States)

NINDS Neuronal Migration Disorders Information Page Table of Contents (click to jump to sections) What is Neuronal Migration Disorders? Is there ... being done? Clinical Trials Organizations What is Neuronal Migration Disorders? Neuronal migration disorders (NMDs) are a group ...

268

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)

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.

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

2005-02-01

269

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

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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

Héctor Riveros

2007-12-01

270

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese 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.

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

2009-11-01

271

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

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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.

Ernesto Odriozola

2009-11-01

272

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in spanish 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

Heraldo Lorena, Guida; Neivo Luiz, Zorzetto.

2007-09-01

273

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

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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

Heraldo Lorena Guida

2007-09-01

274

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

Energy Technology Data Exchange (ETDEWEB)

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

Marcelli, Vincenzo [Department of Neuroscience, University of Naples ' Federico II' , Naples (Italy); Esposito, Fabrizio [Department of Neuroscience, University of Naples ' Federico II' , Naples (Italy); Department of Cognitive Neurosciences, University of Maastricht, Maastricht (Netherlands)], E-mail: fabrizio.esposito@unina.it; Aragri, Adriana [Department of Neurological Sciences, Second University of Naples, Naples (Italy); Furia, Teresa; Riccardi, Pasquale [Department of Neuroscience, University of Naples ' Federico II' , Naples (Italy); Tosetti, Michela; Biagi, Laura [I.R.C.S.S. ' Stella Maris' , Pisa (Italy); Marciano, Elio [Department of Neuroscience, University of Naples ' Federico II' , Naples (Italy); Di Salle, Francesco [Department of Cognitive Neurosciences, University of Maastricht, Maastricht (Netherlands); I.R.C.S.S. ' Stella Maris' , Pisa (Italy); Department of Neurosciences, University of Pisa, Pisa (Italy)

2009-05-15

275

The Relationship between Vestibular Function and Topographical Memory in Older Adults  

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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.

Fred Henry Previc

2014-06-01

276

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.

277

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

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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.

Vahid Moradi

2015-02-01

278

Vestibular impairment in older people frequently contributes to dizziness as part of a geriatric syndrome.  

Science.gov (United States)

Research to identify whether dizziness is a geriatric syndrome has largely overlooked often treatable vestibular causes. To ascertain the degree to which vestibular and other causes of dizziness interact in older people, an eight-month retrospective case-note review was undertaken in patients aged ?: 65 years referred with dizziness or imbalance to an audiovestibular medicine clinic. Of 41 patients aged 65-93 years old, 15 (37%) had multiple symptom triggers, 23 (56%) had recent dizziness-related falls, 24 (59%) and 10 (24%) had peripheral and central vestibular causes for dizziness respectively, whereas 6 (15%) had both. Sixteen (39%) had benign paroxysmal positional vertigo, of which 13 (32%) had an additional peripheral vestibular impairment. Twenty-six (63%) had other (general medical/cardiac) causes; of these 13 (50%) also had vestibular causes. Polypharmacy, orthostatic hypotension, psychotropic drug use and anxiety were common contributory factors. Vestibular causes of dizziness contribute to a multifactorial geriatric syndrome. All patients with dizziness and falls should have a vestibular assessment (especially peripheral) to improve quality of life and reduce falls. PMID:25650194

Ahearn, David J; Umapathy, Dolores

2015-02-01

279

Prevalence of hydrocephalus in 157 patients with vestibular schwannoma  

Energy Technology Data Exchange (ETDEWEB)

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

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

2005-05-01

280

Improving Sensorimotor Function and Adaptation using Stochastic Vestibular Stimulation  

Science.gov (United States)

Astronauts experience sensorimotor changes during adaption to G-transitions that occur when entering and exiting microgravity. Post space flight, these sensorimotor disturbances can include postural and gait instability, visual performance changes, manual control disruptions, spatial disorientation, and motion sickness, all of which can hinder the operational capabilities of the astronauts. Crewmember safety would be significantly increased if sensorimotor changes brought on by gravitational changes could be mitigated and adaptation could be facilitated. The goal of this research is to investigate and develop the use of electrical stochastic vestibular stimulation (SVS) as a countermeasure to augment sensorimotor function and facilitate adaptation. For this project, SVS will be applied via electrodes on the mastoid processes at imperceptible amplitude levels. We hypothesize that SVS will improve sensorimotor performance through the phenomena of stochastic resonance, which occurs when the response of a nonlinear system to a weak input signal is optimized by the application of a particular nonzero level of noise. In line with the theory of stochastic resonance, a specific optimal level of SVS will be found and tested for each subject [1]. Three experiments are planned to investigate the use of SVS in sensory-dependent tasks and performance. The first experiment will aim to demonstrate stochastic resonance in the vestibular system through perception based motion recognition thresholds obtained using a 6-degree of freedom Stewart platform in the Jenks Vestibular Laboratory at Massachusetts Eye and Ear Infirmary. A range of SVS amplitudes will be applied to each subject and the subjectspecific optimal SVS level will be identified as that which results in the lowest motion recognition threshold, through previously established, well developed methods [2,3,4]. The second experiment will investigate the use of optimal SVS in facilitating sensorimotor adaptation to system disturbances. Subjects will adapt to wearing minifying glasses, resulting in decreased vestibular ocular reflex (VOR) gain. The VOR gain will then be intermittently measured while the subject readapts to normal vision, with and without optimal SVS. We expect that optimal SVS will cause a steepening of the adaptation curve. The third experiment will test the use of optimal SVS in an operationally relevant aerospace task, using the tilt translation sled at NASA Johnson Space Center, a test platform capable of recreating the tilt-gain and tilt-translation illusions associated with landing of a spacecraft post-space flight. In this experiment, a perception based manual control measure will be used to compare performance with and without optimal SVS. We expect performance to improve in this task when optimal SVS is applied. The ultimate goal of this work is to systematically investigate and further understand the potential benefits of stochastic vestibular stimulation in the context of human space flight so that it may be used in the future as a component of a comprehensive countermeasure plan for adaptation to G-transitions.

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

2014-01-01

281

[Spatial positional orientation in deaf-mute individuals with bilateral vestibular areflexia].  

Science.gov (United States)

Ten deaf-mute subjects with total vestibular areflexia were subjected to positional tests, i.e. assessment of the postural subjective vertical and horizontal plane by deviations in the frontal and sagittal plane. The tests were performed in the author's modification of a Grahe table. Comparison with the results of 10 healthy subjects revealed that extinction of vestibular activity increases the inaccuracy of assessment of the body position in space. The conclusion is: the vestibular (otolith) apparatus supplements and makes the activity of all other gravireceptors more accurate but not hold a dominant place among them. PMID:2225167

Cerný, E

1990-09-01

282

Vestibular unit transplantation in the coverage of gingival recession: a microsurgical approach.  

Science.gov (United States)

The palate, maxillary tuberosity and edentulous ridges are generally used as the donor sites for connective tissue grafts. This article shows the use of vestibular soft tissue of a tooth in the coverage of localized gingival recession. The vestibular unit was harvested during crown lengthening procedures, sutured over the denuded root surface, and covered with a coronally advanced flap without vertical incisions. The healing was uneventful with complete coverage of the recession up to 18 months. The vestibular unit of a tooth can serve as the donor area for a connective tissue graft in the coverage of gingival recessions, resulting in stable outcomes. PMID:25289386

Nizam, Nejat; Akcal?, Aliye

2014-01-01

283

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  

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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.

Gustavo Duarte Paiva Ferreira

2009-04-01

284

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

Scientific Electronic Library Online (English)

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 p [...] articipação 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. Abstract in english 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 con [...] ditions. 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.

Marcos Antônio, Nemetz; Paulo Augusto de Lima, Pontes; Vanessa Pedrosa, Vieira; Reinaldo Kazuo, Yazaki.

2005-02-01

285

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

Scientific Electronic Library Online (English)

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 d [...] os 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. Abstract in english 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 hum [...] ans 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.

Aline Cabral de, Oliveira; Ricardo, David; José Fernando, Colafêmina.

2008-10-01

286

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)

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.

Aline Cabral de Oliveira

2008-10-01

287

The Septate Junction Protein Caspr is Required for Structural Support and Retention of KCNQ4 at Calyceal Synapses of Vestibular Hair Cells  

Science.gov (United States)

The afferent innervation contacting the type I hair cells of the vestibular sensory epithelia form distinct calyceal synapses. The apposed pre- and post-synaptic membranes at this large area of synaptic contact are kept at a remarkably regular distance. Here, we show by freeze-fracture electron microscopy that a patterned alignment of proteins at the calyceal membrane resembles a type of intercellular junction that is rare in vertebrates, the septate junction (SJ). We found that a core molecular component of SJs, Caspr, colocalizes with the K+ channel KCNQ4 at the post-synaptic membranes of these calyceal synapses. Immunolabeling and ultrastructural analyses of Caspr knockout mice reveal that, in the absence of Caspr, the separation between the membranes of the hair cells and the afferent neurons is conspicuously irregular and often increased by an order of magnitude. In these mutants, KCNQ4 fails to cluster at the post-synaptic membrane and appears diffused along the entire calyceal membrane. Our results indicate that a septate-like junction provides structural support to calyceal synaptic contact with the vestibular hair cell, and that Caspr is required for the recruitment or retention of KCNQ4 at these synapses. PMID:19279247

Sousa, Aurea D.; Andrade, Leonardo R.; Salles, Felipe T.; Pillai, Anilkumar M.; Buttermore, Elizabeth; Bhat, Manzoor A.; Kachar, Bechara

2009-01-01

288

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

Science.gov (United States)

This study aimed to investigate the effects of ballet-specific vestibular stimulation and fatigue on static postural control in ballet dancers and to establish whether these effects differ across varying levels of ballet training. Dancers were divided into three groups: professional, pre-professional, and recreational. Static postural control of 23 dancers was measured on a force platform at baseline and then immediately, 30 seconds, and 60 seconds after vestibular stimulation (pirouettes) and induction of fatigue (repetitive jumps). The professional dancers' balance was unaffected by both the vestibular stimulation and the fatigue task. The pre-professional and recreational dancers' static sway increased following both perturbations. It is concluded that professional dancers are able to compensate for vestibular and fatiguing perturbations due to a higher level of skill-specific motor training. PMID:24844423

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

2014-01-01

289

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

Science.gov (United States)

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.

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

1981-01-01

290

Microgravity (STS-90 neurolab-mission) influences synapse formation in a vestibular nucleus of fish brain  

Science.gov (United States)

Synapse counting was undertaken by conventional electron microscopy in primary vestibular integration centers (i.e., Nucleus descendens, Nd, and Nucleus magnocellularis, Nm, of the brainstem Area octavolateralis) and in the diencephalic visual Nucleus corticalis (Nc) of spaceflown neonate swordtail fish Xiphophorus helleri as well as in 1g control siblings. Spaceflight (16 days microgravity, ?g, STS-90 Neurolab-Mission) yielded an increase in synaptic contacts only within the vestibular Nd indicating that lack of input resulted in compensation processes. No effect of ?g, however, was observed in the visual Nc and in the vestibular Nm which is situated in the close vicinity of the Nd. In contrast to the latter, the Nm does not receive exclusively vestibular input, but inputs from the lateral line as well, possibly providing sufficient input at microgravity.

Anken, R. H.; Ibsch, M.; Rahmann, H.

291

Bilateral multicanal benign paroxysmal positional vertigo coexisting with a vestibular schwannoma: case report.  

Science.gov (United States)

We describe a rarely encountered case of coexisting bilateral multicanal benign paroxysmal positional vertigo (BPPV) and vestibular schwannoma in a 56-year-old woman. The patient had presented with a 10-year history of dizziness and imbalance, and her vestibular findings were perplexing. We decided on a working diagnosis of BPPV and began treatment. After several months of canalith repositioning maneuvers had failed to resolve her symptoms, we obtained magnetic resonance imaging, which revealed the presence of the vestibular schwannoma. This case serves as a reminder of the importance of differentiating between central and peripheral vestibular disorders, as well as central and anterior canal BPPV-induced down-beating nystagmus in order to establish the correct diagnosis and initiate appropriate treatment. PMID:21229492

Karatayli-Ozgursoy, Selmin; Stamper, Greta C; Lundy, Larry B; Zapala, David A

2011-01-01

292

What can posturography tell us about vestibular function?  

Science.gov (United States)

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.

Black, F. O.

2001-01-01

293

Calcification of vestibular schwannoma: a case report and literature review  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Calcification rarely occurs in vestibular schwannoma (VS, and only seven cases of calcified VS have been reported in the literature. Here, we report a 48-year-old man with VS, who had a history of progressive left-sided hearing loss for 3 years. Neurological examination revealed that he had left-sided hearing loss and left cerebellar ataxia. Magnetic resonance imaging and computerized tomography angiography showed a mass with calcification in the left cerebellopontine angle (CPA. The tumor was successfully removed via suboccipital craniotomy, and postoperative histopathology showed that the tumor was a schwannoma. We reviewed seven cases of calcified VS that were previously reported in the literature, and we analyzed and summarized the characteristics of these tumors, including the calcification, texture, and blood supply. We conclude that calcification in VS is associated with its texture and blood supply, and these characteristics affect the surgical removal of the tumor.

Zhang Yang

2012-10-01

294

Hypergravity effects on succinate dehydrogenase reactivity in fish vestibular ganglia  

Science.gov (United States)

Larval cichlid fish ( Oreochromis mossambicus) were kept at 3 g hypergravity (centrifuge) for 14 or 21 days. Subsequently, succinate dehydrogenase reactivity was histochemically demonstrated and densitometrically determined in the gangliones utricularis and saccularis as well as (for control) in the diencephalic, non-vestibular Nucleus glomerulosus posterioris. It was found that succinate dehydrogenase reactivity within the ganglion utricularis was significantly increased in experimental animals as compared to the 1 g controls ( p < 0.05 and p < 0.01 after 14 and 21 days of hypergravity, respectively), whereas hypergravity had no effect on succinate dehydrogenase reactivity in the ganglion saccularis and in the Nucleus glomerulosus posterioris. This result clearly indicates that hypergravity exclusively affects the metabolic activity of a ganglion, which is directly involved in the transmission of gravity inputs.

Kempf, J.; Anken, R.; Hilbig, R.

2006-01-01

295

Absence of nystagmus during REM sleep in patients with vestibular neuritis  

OpenAIRE

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. ...

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

2001-01-01

296

Vestibular dysfunction, altered macular structure and trait localization in A/J inbred mice.  

Science.gov (United States)

A/J mice develop progressive hearing loss that begins before 1 month of age and is attributed to cochlear hair cell degeneration. Screening tests indicated that this strain also develops early onset vestibular dysfunction and has otoconial deficits. The purpose of this study was to characterize the vestibular dysfunction and macular structural pathology over the lifespan of A/J mice. Vestibular function was measured using linear vestibular evoked potentials (VsEPs). Macular structural pathology was evaluated using light microscopy, scanning electron microscopy, transmission electron microscopy, confocal microscopy and Western blotting. Individually, vestibular functional deficits in mice ranged from mild to profound. On average, A/J mice had significantly reduced vestibular sensitivity (elevated VsEP response thresholds and smaller amplitudes), whereas VsEP onset latency was prolonged compared to age-matched controls (C57BL/6). A limited age-related vestibular functional loss was also present. Structural analysis identified marked age-independent otoconial abnormalities in concert with some stereociliary bundle defects. Macular epithelia were incompletely covered by otoconial membranes with significantly reduced opacity and often contained abnormally large or giant otoconia as well as normal-appearing otoconia. Elevated expression of key otoconins (i.e., otoconin 90, otolin and keratin sulfate proteoglycan) ruled out the possibility of reduced levels contributing to otoconial dysgenesis. The phenotype of A/J was partially replicated in a consomic mouse strain (C57BL/6J-Chr 17(A/J)/NaJ), thus indicating that Chr 17(A/J) contained a trait locus for a new gene variant responsible to some extent for the A/J vestibular phenotype. Quantitative trait locus analysis identified additional epistatic influences associated with chromosomes 1, 4, 9 and X. Results indicate that the A/J phenotype represents a complex trait, and the A/J mouse strain presents a new model for the study of mechanisms underlying otoconial formation and maintenance. PMID:25645995

Vijayakumar, Sarath; Lever, Teresa E; Pierce, Jessica; Zhao, Xing; Bergstrom, David; Lundberg, Yunxia Wang; Jones, Timothy A; Jones, Sherri M

2015-04-01

297

The impact of stereotactic radiosurgery in the management of neurofibromatosis type 2-related vestibular schwannomas  

OpenAIRE

Although there is an ongoing debate about the ideal management of vestibular schwannomas, radiosurgical treatment has become popular in the past decade with good to excellent results reported. Given the young age at presentation, the bilateral nature of vestibular schwanomas, the presence of other associated central nervous system tumors, patients with neurofibromatosis Type 2 (NF2) are very complex and present significant management challenges. Although results do not seem to be as good as f...

Lustgarten, Leonardo

2013-01-01

298

Video Endoscopy-Assisted Vestibular Neurectomy: A New Approach to the Eighth Cranial Nerve  

OpenAIRE

Disequilibrium, ranging from lightheadedness to severe vertigo, is frequently of great concern to the patients with a variety of inner ear diseases, and may cause occupational and social disability. Vestibular nerve section may be considered when vestibular symptoms are resistant to medical therapy and associated with serviceable hearing in the involved ear. During the last century, numerous authors described several routes for intracranial section of the eighth nerve, such as lateral subocci...

Ozluoglu, Levent N.; Akbasak, Aytac

1996-01-01

299

The Impact of Hypotension due to the Trigeminocardiac Reflex on Auditory Function in Vestibular Schwannoma Surgery  

OpenAIRE

Objective. To study the impact of the trigeminocardiac reflex (TCR) on postoperative auditory function in vestibular schwannoma surgery. Surgery for vestibular schwannomas (acoustic neuromas) and other procedures close to the fifth cranial nerve at its intra- or extracranial course may lead to patient?s bradycardia or even asystolia along with arterial hypotension. This phenomenon is described as the TCR. Clinical Material and Methods. One hundred subsequent patients scheduled for vest...

Koerbel, Andrei

2005-01-01

300

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.)

301

Fractionated Stereotactic Radiotherapy of Vestibular Schwannomas Accelerates Hearing Loss  

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

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

2012-08-01

302

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.

303

Prevalence of hydrocephalus in 157 patients with vestibular schwannoma  

International Nuclear Information System (INIS)

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

304

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)

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.

J.S. Sarkissian

2010-03-01

305

Interferencia da taxa de estimulo na avaliacao do potencial evocado miogenico vestibular / The impact of stimulation rates in vestibular evoked myogenic potential testing  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Languages: English, Portuguese Abstract in portuguese Os potenciais miogênicos evocados vestibulares (VEMP) vêm sendo empregados como exame complementar para estudos otoneurológicos, ainda pouco explorados clinicamente. Esse potencial avalia a função vestibular, especificamente do sáculo, nervo vestibular inferior e/ou núcleo vestibular. OBJETIVO: Ver [...] ificar a maior taxa de estímulos possível (e confiável) na obtenção do VEMP. MÉTODO: Foi registrado o potencial em 18 sujeitos, variando-se a taxa de estímulos entre 5,1 e 40,8 estímulos/s. Forma de estudo: Estudo de coorte contemporânea com corte transversal. RESULTADOS: As latências se mantiveram constantes e as amplitudes foram progressivamente reduzidas com o aumento da taxa de estimulação. Contudo, não houve diferença estatisticamente significativa entre os parâmetros simultaneamente, quando aplicados os testes ANOVA e Kruskal-Wallis. Os dados obtidos nesta pesquisa demonstraram que, quando comparadas as taxas de estimulação de 5,1 e 10,2 estímulos/s, houve ausência de diferença estatisticamente significativas para o parâmetro latência. CONCLUSÃO: Conclui-se que a maior taxa de estimulação confiável é a de 10,2 estímulos/s, para a amostra estudada de adultos jovens ouvintes normais. Abstract in english Vestibular evoked myogenic potentials (VEMP) have been used in complementary otoneurological assessment, but the use of VEMP in clinical settings is limited. VEMPs can be used to assess vestibular function, particularly of the saccule, the inferior vestibular nerve, and/or the vestibular nucleus. O [...] BJECTIVE: To verify the highest possible - and reliable - stimulation rate to obtain VEMPs. METHOD: The VEMPs of 18 subjects were acquired using stimulation rates ranging between 5.1 and 40.8 stimuli per second. Study design: cross-sectional contemporary cohort study. RESULTS: Latencies were kept unaltered and amplitudes were progressively reduced as stimulation rates were increased. However, ANOVA and the Kruskal-Wallis test failed to find statistically significant differences between the tested parameters. The study further indicated that when stimulation rates of 5.1 and 10.2 stimuli per second were compared, no statistically significant differences were observed in latency. CONCLUSION: The highest reliable stimulation rate observed in the group of young adults with normal hearing included in this study was 10.2 stimuli per second.

Aline Tenorio Lins, Carnauba; Otavio Gomes, Lins; Ilka do Amaral, Soares; Kelly Cristina Lira de, Andrade; Pedro de Lemos, Menezes.

2013-09-01

306

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

Scientific Electronic Library Online (English)

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.

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

2010-03-01

307

Motor Neuron Diseases  

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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 ...

308

Effects of selected pharmacological agents on avian auditory and vestibular compound action potentials.  

Science.gov (United States)

Glutamate is currently the consensus candidate for the hair cell transmitter in the inner ear of vertebrates. However, other candidate transmitter systems have been proposed and there may be differences in this regard for auditory and vestibular neuroepithelia. In the present study, perilymphatic perfusion was used to deliver prescribed concentrations of ten drugs to the interstitial fluids of the inner ear of hatchling chickens (n = 124). Dose-response curves were obtained for four of these pharmacological agents. The work was carried out in part to distinguish further the neuroepithelial chemical receptors mediating auditory and vestibular compound action potentials (CAPs). Kainic acid (KA) eliminated both auditory and vestibular responses. D-alpha-Aminoadipic acid (DAA) and dizocilpine maleate (MK-801), both NMDA-specific antagonists, failed to alter vestibular CAPs at any concentration. MK-801 significantly and selectively reduced auditory CAPs at concentrations equal to or greater than 1 mM. Similarly, kynurenic acid (4-hydroxyquinoline-2-carboxylic acid, 1 mM), a glutamate antagonist, significantly reduced auditory but not vestibular CAPs. A non-NMDA glutamate receptor antagonist, 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), reduced vestibular CAPs significantly but only at the highest concentration tested (1 mM). In contrast, CNQX reduced auditory responses at concentration as low as 1 microM. The CNQX concentration effective in reducing auditory CAPs by 50% (EC(50)) was approximately 20 microM. Glutamate (1 mM) as well as alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA), a glutamate agonist, significantly reduced auditory CAPs (AMPA EC(50)=100 microM). Bicuculline, a GABA(A) receptor antagonist, and L-NAME, a nitric oxide synthase inhibitor, failed to alter responses from either modality. These findings support the hypothesis that glutamate receptors mediate auditory CAPs in birds. However, the results underscore a remarkable difference in sensitivity of the vestibular neuroepithelium (here gravity receptors) to non-NMDA receptor antagonists. The basis of the vestibular insensitivity to glutamate blockers is unknown but it may reflect differences in receptors themselves, differences in the transmission modes available to vestibular synapses or differences in the access of compounds to vestibular neuroepithelial receptors from the interstitial-perilymphatic fluid spaces. PMID:15350279

Irons-Brown, Shunda R; Jones, Timothy A

2004-09-01

309

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

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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

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

2015-02-01

310

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

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Zebrin II (aldolase C) is expressed in a subset of Purkinje cells in the mammalian and avian cerebella such that there is a characteristic parasagittal organization of zebrin-immunopositive stripes alternating with zebrin-immunonegative stripes. Zebrin is expressed not only in the soma and dendrites of Purkinje cells but also in their axonal terminals. Here we describe the distribution of zebrin immunoreactivity in both the vestibular and the cerebellar nuclei of pigeons (Columba livia) and hummingbirds (Calypte anna, Selasphorus rufus). In the medial cerebellar nucleus, zebrin-positive labeling was particularly heavy in the “shell,” whereas the “core” was zebrin negative. In the lateral cerebellar nucleus, labeling was not as heavy, but a positive shell and negative core were also observed. In the vestibular nuclear complex, zebrin-positive terminal labeling was heavy in the dorsolateral vestibular nucleus and the lateral margin of the superior vestibular nucleus. The central and medial regions of the superior nucleus were generally zebrin negative. Labeling was moderate to heavy in the medial vestibular nucleus, particulary the rostral half of the parvocellular subnucleus. A moderate amount of zebrin-positive labeling was present in the descending vestibular nucleus: this was heaviest laterally, and the central region was generally zebrin negative. Zebrin-positive terminals were also observed in the the cerebellovestibular process, prepositus hypoglossi, and lateral tangential nucleus. We discuss our findings in light of similar studies in rats and with respect to the corticonuclear projections to the cerebellar nuclei and the functional connections of the vestibulocerebellum with the vestibular nuclei. PMID:22105608

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

2012-05-01

311

Cortical representation of saccular vestibular stimulation: VEMPs in fMRI.  

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Short tone bursts trigger a vestibular evoked myogenic potential (VEMP), an inhibitory potential which reflects a component of the vestibulocollic reflex (VCR). These potentials arise as a result of activation of the sacculus and are expressed through the vestibulo-collic reflex (VCR). Up to now, the ascending projections of the sacculus are unknown in humans, only the representation of the semicircular canals or the entire vestibular nerve has been demonstrated. The aim of this study was to determine whether a sacculus stimulus that evoked VEMPs could activate vestibular cortical areas in fMRI. To determine this, we studied the differential effects of unilateral VEMP stimulation in 21 healthy right-handers in a clinical 1.5 T scanner while wearing piezo electric headphones. A unilateral VEMP stimulus and two auditory control stimuli were given in randomized order over the stimulated ear. A random effects statistical analysis was done with SPM2 (pcortical vestibular network within both hemispheres, including the posterior insular cortex, the middle and superior temporal gyri, and the inferior parietal cortex. (ii) The activation pattern was elicited bilaterally with a predominance of the right hemisphere in right-handers. (iii) Saccular vestibular projection was predominantly ipsilateral, whereas (iv) pure acoustic stimuli were processed with a predominance of the respective contralateral and mainly in the left hemisphere. This is the first demonstration by means of fMRI of the cortical representation of the saccular input at cortical level. The activation pattern is similar to that known from the stimulation of the entire vestibular nerve or the horizontal semicircular canal. Our data give evidence of a task-dependent separation of the processing within the vestibular otolith and the auditory systems in the two hemispheres. PMID:17919936

Schlindwein, P; Mueller, M; Bauermann, T; Brandt, T; Stoeter, P; Dieterich, M

2008-01-01

312

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

Energy Technology Data Exchange (ETDEWEB)

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.)

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

313

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

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Full Text Available 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 (pOBJETIVO: 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 multivariada (p<0,05 e IC de 95%. RESULTADOS: Os pacientes apresentaram média de 12,86 ± 6,39 pontos no GDS, sendo que 67 idosos (55,8% pontuaram acima da nota de corte 11. O modelo preditivo para piora dos sintomas depressivos foi composto por gênero feminino, distúrbios de memória e da concentração, insônia, hipoacusia, visão péssima, não utilização de dispositivo de auxílio à marcha e maior impacto da tontura no aspecto emocional. CONCLUSÃO: O maior número de sintomas depressivos de idosos vestibulopatas crônicos está relacionado à presença de distúrbios de memória e da concentração, insônia, hipoacusia, visão péssima, maior impacto da tontura no aspecto emocional, gênero feminino e não utilização de dispositivo de auxílio à marcha.

Juliana Maria Gazzola

2009-06-01

314

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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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.

Angela Cristina Calciolari

2002-11-01

315

diferenciación neuronal  

Directory of Open Access Journals (Sweden)

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.

Gabriel Moreno Gonz\\u00E1lez

2006-01-01

316

Visual and vestibular perceptual thresholds each demonstrate better precision at specific frequencies and also exhibit optimal integration.  

Science.gov (United States)

Prior studies show that visual motion perception is more precise than vestibular motion perception, but it is unclear whether this is universal or the result of specific experimental conditions. We compared visual and vestibular motion precision over a broad range of temporal frequencies by measuring thresholds for vestibular (subject motion in the dark), visual (visual scene motion) or visual-vestibular (subject motion in the light) stimuli. Specifically, thresholds were measured for motion frequencies spanning a two-decade physiological range (0.05-5 Hz) using single-cycle sinusoidal acceleration roll tilt trajectories (i.e., distinguishing left-side down from right-side down). We found that, while visual and vestibular thresholds were broadly similar between 0.05 and 5.0 Hz, each cue is significantly more precise than the other at certain frequencies. Specifically, we found that 1) visual and vestibular thresholds were indistinguishable at 0.05 Hz and 2 Hz (i.e., similarly precise); 2) visual thresholds were lower (i.e., vision more precise) than vestibular thresholds between 0.1 Hz and 1 Hz; and 3) visual thresholds were higher (i.e., vision less precise) than vestibular thresholds above 2 Hz. This shows that vestibular perception can be more precise than visual perception at physiologically relevant frequencies. We also found that sensory integration of visual and vestibular information is consistent with static Bayesian optimal integration of visual-vestibular cues. In contrast with most prior work that degraded or altered sensory cues, we demonstrated static optimal integration using natural cues. PMID:24371292

Karmali, Faisal; Lim, Koeun; Merfeld, Daniel M

2014-06-15

317

Left Cathodal Trans-Cranial Direct Current Stimulation of the Parietal Cortex Leads to an Asymmetrical Modulation of the Vestibular-Ocular Reflex?  

OpenAIRE

Multi-sensory visuo-vestibular cortical areas within the parietal lobe are important for spatial orientation and possibly for descending modulation of the vestibular-ocular reflex (VOR). Functional imaging and lesion studies suggest that vestibular cortical processing is localized primarily in the non-dominant parietal lobe. However, the role of inter-hemispheric parietal balance in vestibular processing is poorly understood. Therefore, we tested whether experimentally induced asymmetries in ...

Arshad, Qadeer; Nigmatullina, Yuliya; Roberts, R. Edward; Bhrugubanda, Vamsee; Asavarut, Paladd; Bronstein, Adolfo M.

2014-01-01

318

Changes in resting-state fMRI in vestibular neuritis.  

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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

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

2014-11-01

319

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

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The aim of the current study was to characterize the brain activation in response to two modes of vestibular stimulation: skull tap and auditory tone burst. The auditory tone burst has been used in previous studies to elicit saccular Vestibular Evoked Myogenic Potentials (VEMP) (Colebatch & Halmagyi 1992; Colebatch et al. 1994). Some researchers have reported that airconducted skull tap elicits both saccular and utricle VEMPs, while being faster and less irritating for the subjects (Curthoys et al. 2009, Wackym et al., 2012). However, it is not clear whether the skull tap and auditory tone burst elicit the same pattern of cortical activity. Both forms of stimulation target the otolith response, which provides a measurement of vestibular function independent from semicircular canals. This is of high importance for studying the vestibular disorders related to otolith deficits. Previous imaging studies have documented activity in the anterior and posterior insula, superior temporal gyrus, inferior parietal lobule, pre and post central gyri, inferior frontal gyrus, and the anterior cingulate cortex in response to different modes of vestibular stimulation (Bottini et al., 1994; Dieterich et al., 2003; Emri et al., 2003; Schlindwein et al., 2008; Janzen et al., 2008). Here we hypothesized that the skull tap elicits the similar pattern of cortical activity as the auditory tone burst. Subjects put on a set of MR compatible skull tappers and headphones inside the 3T GE scanner, while lying in supine position, with eyes closed. All subjects received both forms of the stimulation, however, the order of stimulation with auditory tone burst and air-conducted skull tap was counterbalanced across subjects. Pneumatically powered skull tappers were placed bilaterally on the cheekbones. The vibration of the cheekbone was transmitted to the vestibular cortex, resulting in vestibular response (Halmagyi et al., 1995). Auditory tone bursts were also delivered for comparison. To validate our stimulation method, we measured the ocular VEMP outside of the scanner. This measurement showed that both skull tap and auditory tone burst elicited vestibular evoked activation, indicated by eye muscle response. Our preliminary analyses showed that the skull tap elicited activation in medial frontal gyrus, superior temporal gyrus, postcentral gyrus, transverse temporal gyrus, anterior cingulate, and putamen. The auditory tone bursts elicited activation in medial frontal gyrus, superior temporal gyrus, superior frontal gyrus, precentral gyrus, inferior and superior parietal lobules. In line with our hypothesis, skull taps elicited a pattern of cortical activity closely similar to one elicited by auditory tone bursts. Further analysis will determine the extent to which the skull taps can replace the auditory tone stimulation in clinical and basic science vestibular assessments.

Noohi, Fatemeh; Kinnaird, Catherine; Wood, Scott; Bloomberg, Jacob; Mulavara, Ajitkumar; Seidler, Rachael

2014-01-01

320

Avaliação vestibular na vertigem posicional paroxística benigna típica e atípica / Vestibular evaluation in typical and atypical benign paroxysmal positional vertigo  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese OBJETIVO: verificar a prevalência da vertigem posicional paroxística benigna típica e atípica, correlacionar a sintomatologia e resultados da avaliação vestibular, de ambas as formas. MÉTODOS: entre janeiro de 2007 e março de 2008, verificou-se todos os pacientes que apresentaram nistagmo e/ou verti [...] gem às provas de posicionamento, descrevendo a história clínica e avaliação vestibular por vectoeletronistagmografia modelo Vecwin, Neurograff. Foram estabelecidos dois grupos: o que apresentou nistagmo às provas de posicionamento e os que somente referiram vertigem. RESULTADOS: de 399 pacientes avaliados no Centro Clínico Mãe de Deus, Porto Alegre, 86 (31,73%) apresentaram história clínica de vertigem posicional, 45 (49,45%) com vertigem posicional típica e 41 (45,05%) com vertigem atípica, idade média de 61 e 52 anos, respectivamente. Houve predomínio do sexo feminino e histórico familiar positivo para o quadro em 28 (30,76%) pacientes, maior acometimento bilateral, em ambas as formas. 39,02% dos pacientes da forma típica demoraram em torno de um mês para buscar atendimento, 22,22% dos pacientes da forma atípica levaram mais de cinco anos. O nistagmo espontâneo e pré-calórico esteve presente em ambas as formas, com normorreflexia em 35 (40,6%), predomínio direcional em 27 (31,03%), hiperreflexia bilateral em 9 (10,4%) e unilateral em 10 (11,6%) dos pacientes. Avaliação audiológica foi realizada em apenas 56 (65,11%) dos casos. CONCLUSÃO: a queixa principal foi a mesma em ambos os grupos, que concordaram em diversos aspectos. Os pacientes da forma típica e atípica diferiram, principalmente, no tempo de acometimento e ocorrência de patologias associadas. Abstract in english PURPOSE: to check the prevalence of typical and atypical benign positional paroxistic vertigo and relate clinical history and results of vestibular evaluation for both types. METHODS: all patients that showed nystagmus and/or vertigo in positional tests, between January 2007 and March 2008, were des [...] cribed through clinical history and vectoelectronystagmography, Vecwin model, Neurograff. The patients were arranged in two groups: those with nystagmus in the positional tests and those with just vertigo. RESULTS: from 399 patients evaluated at Centro Clínico Mãe de Deus, Porto Alegre, 86 (31.73%) referred clinical history of positional vertigo, 45 (49.45%) with typical form and 41 (45.05%) with atypical form, mean age 61 and 52 years, respectively. The female gender was prevalent for both groups, as well as the familiar history for the symptoms in 28 (30.76%) patients, both sides were affected, in both groups. 39.02% of the patients of typical form took 1 month to go to the clinic, 22.22% of the patients of the atypical form took more than 5 years. The spontaneous and per caloric nystagmus were found in both groups, with normorreflexy in 35 (40.6%), directional preponderance in 27 (31.03%), bilateral hiperreflexy in 9 (10.4%) and unilateral in 10 (11.6%) of the patients. Only 56 (65.11%) of the patients were submitted to audiological evaluation. CONCLUSION: the positional vertigo complaint was the same for both groups that agreed in several aspects. Time of the symptoms and associated pathologies were the aspects that patients of the typical and atypical forms differed.

Gisiane, Munaro; Aron Ferreira da, Silveira.

321

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

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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.

João Simão de Melo Neto

2012-01-01

322

Vestibular dysfunction is a clinical feature of the Jervell and Lange-Nielsen Syndrome.  

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Abstract Objectives. To investigate the possible association between Jervell and Lange-Nielsen Syndrome (JLNS) genotype and vestibular dysfunction. Design. In 15 cases with JLNS, clinical data obtained from a semi-structured interview and full medical records were reviewed and post-rotatory nystagmus testing was performed. Results. All genotyped cases (n = 14) had double KCNQ1 mutations. Symptoms of impaired balance were reported in 14/14 deaf JLNS cases. Gross motor developmental delay (not walking without support at 18 months of age) was seen in 11/12 cases with available data (mean age for walking: 24 months). A pathologic post-rotatory test was seen in 9/9 tested subjects, and in 3 subjects clinical testing had been performed showing complete lack of vestibular function. Vestibular dysfunction was seen in deaf JLNS cases with (n = 5) and without (n = 9) cochlear implants, including subjective symptoms (5/5 vs. 9/9) and gross motor developmental delay (5/5 vs. 6/8). Conclusions. We identified a high frequency of symptoms and signs associated with vestibular dysfunction in deaf JLNS cases, irrespective of previous cochlear implantation. Disruption of endolymph homeostasis in the inner ear, including cochlea and vestibular system, by profound KCNQ1 function loss is the proposed mechanism. PMID:25471708

Winbo, Annika; Rydberg, Annika

2015-02-01

323

The Vestibular-Auditory Interaction for Auditory Brainstem Response to Low Frequencies  

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Since saccular projection is sound sensitive, the objective is to investigate the possibility that the saccular projections may contribute to auditory brainstem response to 500?HZ tone burst (ABR500?HZ). During the case-control research, twenty healthy controls compared to forty selected case groups as having chronic and resistant BPPV were evaluated in the audiology department of Hamadan University of Medical Sciences (Hamadan, Iran). Assessment is comprised of audiologic examinations, cervical vestibular evoked myogenic potentials (cVEMPs), and ABR500?HZ. We found that forty affected ears of BPPV patients with decreased vestibular excitability as detected by abnormal cVEMPs had abnormal results in ABR500?HZ, whereas unaffected ears presented normal findings. Multiple comparisons of mean p13, n23 latencies, and peak-to-peak amplitudes between three groups (affected, unaffected, and healthy ears) were significant. In conclusion, the saccular nerves can be projective to auditory bundles and interact with auditory brainstem response to low frequencies. Combine the cVEMPs and ABR500?HZ in battery approach tests of vestibular assessment and produce valuable data for judgment on the site of lesion. Regarding vestibular cooperation for making of wave V, it is reasonable that the term of ABR500?HZ is not adequate and the new term or vestibular-auditory brainstem response to 500?HZ tone burst is more suitable. PMID:25006510

Gohari, Nasrin

2014-01-01

324

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

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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.

Pandey Rakesh

2009-11-01

325

Tuning and sensitivity of the human vestibular system to low-frequency vibration.  

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Mechanoreceptive hair-cells of the vertebrate inner ear have a remarkable sensitivity to displacement, whether excited by sound, whole-body acceleration or substrate-borne vibration. In response to seismic or substrate-borne vibration, thresholds for vestibular afferent fibre activation have been reported in anamniotes (fish and frogs) in the range -120 to -90 dB re 1g. In this article, we demonstrate for the first time that the human vestibular system is also extremely sensitive to low-frequency and infrasound vibrations by making use of a new technique for measuring vestibular activation, via the vestibulo-ocular reflex (VOR). We found a highly tuned response to whole-head vibration in the transmastoid plane with a best frequency of about 100 Hz. At the best frequency we obtained VOR responses at intensities of less than -70 dB re 1g, which was 15 dB lower than the threshold of hearing for bone-conducted sound in humans at this frequency. Given the likely synaptic attenuation of the VOR pathway, human receptor sensitivity is probably an order of magnitude lower, thus approaching the seismic sensitivity of the frog ear. These results extend our knowledge of vibration-sensitivity of vestibular afferents but also are remarkable as they indicate that the seismic sensitivity of the human vestibular system exceeds that of the cochlea for low-frequencies. PMID:18706484

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

2008-10-17

326

Vestibular signal processing in a subject with somatosensory deafferentation: The case of sitting posture  

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Full Text Available Abstract Background The vestibular system of the inner ear provides information about head translation/rotation in space and about the orientation of the head with respect to the gravitoinertial vector. It also largely contributes to the control of posture through vestibulospinal pathways. Testing an individual severely deprived of somatosensory information below the nose, we investigated if equilibrium can be maintained while seated on the sole basis of this information. Results Although she was unstable, the deafferented subject (DS was able to remain seated with the eyes closed in the absence of feet, arm and back supports. However, with the head unconsciously rotated towards the left or right shoulder, the DS's instability markedly increased. Small electrical stimulations of the vestibular apparatus produced large body tilts in the DS contrary to control subjects who did not show clear postural responses to the stimulations. Conclusion The results of the present experiment show that in the lack of vision and somatosensory information, vestibular signal processing allows the maintenance of an active sitting posture (i.e. without back or side rests. When head orientation changes with respect to the trunk, in the absence of vision, the lack of cervical information prevents the transformation of the head-centered vestibular information into a trunk-centered frame of reference of body motion. For the normal subjects, this latter frame of reference enables proper postural adjustments through vestibular signal processing, irrespectively of the orientation of the head with respect to the trunk.

Teasdale Normand

2007-08-01

327

Quality of life questionnaire application in patients before and after vestibular rehabilitation  

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Full Text Available Introduction: Conventional vestibular tests are not efficient instruments to evaluate the level of commitment in the life quality of a patient with dizziness. The quality of life questionnaire specific for dizziness, the Dizziness Handicap Inventory, was translated and validated into Portuguese intending to get over this difficulty in quantifying the vertiginous patient symptoms. Objective: This study aims at comparing the Brazilian Dizziness Handicap Inventory results before and after personalized vestibular rehabilitation in patients diagnosed with chronic vertigo from benign paroxist positional vertigo and chronic vertigo from other causes. Method: Retrospective study of 30 medical records; all of which were submitted to the Brazilian Dizziness Handicap Inventory before and after the personalized vestibular rehabilitation treatment. Results: In the total scores average of vestibular pre-rehabilitation, the benign paroxist positional vertigo had a score of 47.93±24.46 and the chronic vertigo for other causes of 54.40±20.97. At discharge, the benign paroxist positional vertigo scores average was of 6.13±7.22 and in the chronic vertigo from other causes, the scores average was of 26.13±20.51. Conclusion: The commitment of the life quality of individuals with dizziness, both for chronic vertigo from other causes and benign paroxist positional vertigo, was very similar, confirming an important commitment. The vestibular rehabilitation effect for both cases was also efficient and the Dizziness Handicap Inventory was an efficient instrument to evaluate the vertiginous case evolution.

Nishino, Lucia Kazuko

2008-12-01

328

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

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Objectives: 1. To investigate preventive effect of LLL on gentamicin-induced vestibular ototoxicity. 2. To evaluate the effectiveness of lower level laser (LLL) in the treatment of tinnitus. Methods: 1. Twenty guinea pigs were divided into control and laser groups. Vestibular ototoxicity was induced by intratympanic injection of gentamicin into left ear. LLL was irradiated into left ear canal of animals in laser group. Vestibular function of the animals was evaluated with vertical and off-vertical axis rotation testing. 2. Forty patients with tinnitus were treated with ginkgo biloba orally and randomly divided into control and laser groups. The 20 patients of laser group received 80.4 J/cm2 of 830 nm laser, 3 times per week for 4 weeks, via transmeatal irradiation. Tinnitus was evaluated by visual analogue scale (VAS) and tinnitus handicap inventory (THI). Results: 1. Preventive effect of LLL to gentamicin induced vestibular ototoxicity was demonstrated by preventing reduction of gain in slow harmonic acceleration test and modulation in the off-vertical axis rotation test. 2. Eleven of 20 laser group patients have shown significant improvement in VAS and THI compared to those of the control group. Conclusions: 1. LLL therapy may have preventive effect to vestibular ototoxicity. 2. LLL therapy in combination with ginkgo biloba seems to be worth trying on patients with tinnitus.

Rhee, Chung-Ku; Lim, Eun-Seok; Kim, Young-Saeng; Chung, Yong-Won; Jung, Jae-Yun; Chung, Phil-Sang

2006-02-01

329

Functional testing of the vestibular ocular reflex (VOR  

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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.

StefanoRamat

2012-03-01

330

Vestibular schwannoma in patients with sudden sensorineural hearing loss.  

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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 MRI as a screening method. Of the 295 patients with SSNHL, VS was found in 12 (4%). All patients had intrameatal or small to medium-sized tumors. There were three cases with SSNHL in one ear and an incidental finding of intracanalicular VS in the contralateral ear. There were four cases of VS that showed good recovery from SSNHL with corticosteroid treatment. There were two cases that mimicked labyrinthitis with hearing loss and vertigo. A greater number of cases than expected of VS were detected in patients with SSNHL, as a result of increasing widespread use of MRI. Various unusual findings in these patients were identified. MRI would seem to be mandatory in all cases of SSNHL. PMID:22451804

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

2011-03-01

331

Morphology of the Vestibular Utricule in Toadfish, Opsanus Tau  

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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.

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

2003-01-01

332

Zonal variations in K+ currents in vestibular crista calyx terminals.  

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We developed a rodent crista slice to investigate regional variations in electrophysiological properties of vestibular afferent terminals. Thin transverse slices of the gerbil crista ampullaris were made and electrical properties of calyx terminals in central zones (CZ) and peripheral zones (PZ) compared with whole cell patch clamp. Spontaneous action potential firing was observed in 25% of current-clamp recordings and was either regular or irregular in both zones. Firing was abolished when extracellular choline replaced Na(+) but persisted when hair cell mechanotransduction channels or calyx AMPA receptors were blocked. This suggests that ion channels intrinsic to the calyx can generate spontaneous firing. In response to depolarizing voltage steps, outward K(+) currents were observed at potentials above -60 mV. K(+) currents in PZ calyces showed significantly more inactivation than currents in CZ calyces. Underlying K(+) channel populations contributing to these differences were investigated. The KCNQ channel blocker XE991 dihydrochloride blocked a slowly activating, sustained outward current in both PZ and CZ calyces, indicating the presence of KCNQ channels. Mean reduction was greatest in PZ calyces. XE991 also reduced action potential firing frequency in CZ and PZ calyces and broadened mean action potential width. The K(+) channel blocker 4-aminopyridine (10-50 ?M) blocked rapidly activating, moderately inactivating currents that were more prevalent in PZ calyces. ?-Dendrotoxin, a selective blocker of KV1 channels, reduced outward currents in CZ calyces but not in PZ calyces. Regional variations in K(+) conductances may contribute to different firing responses in calyx afferents. PMID:25343781

Meredith, Frances L; Rennie, Katherine J

2015-01-01

333

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

Scientific Electronic Library Online (English)

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

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

2013-06-01

334

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

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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.

Schüz, Joachim; Steding-Jessen, Marianne

2011-01-01

335

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

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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.

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

2001-01-01

336

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

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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.

McCall Andrew A

2009-06-01

337

The influence of voluntary tonic EMG level on the vestibular-evoked myogenic potential.  

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Vestibular-evoked myogenic potentials (VEMPs) are proposed as a reliable test to supplement the current vestibular test battery by providing diagnostic information about saccular and/or inferior vestibular nerve function. VEMPs are short-latency electromyograms (EMGs) evoked by high-level acoustic stimuli and recorded from surface electrodes over the tonically contracted sternocleidomastoid muscle. VEMP amplitude is influenced by the EMG level, which must be controlled. This study examined the ability of subjects to achieve the EMG target levels over a range of target levels typically used during VEMP recordings. In addition, the influence of target EMG level on the latency and amplitude of the click- and tone-evoked VEMP was examined. The VEMP amplitude increased as a function of EMG target level, and the latency remained constant. EMG target levels ranging from 30 microV to 50 microV are suggested for clinical application of the VEMP. PMID:15543465

Akin, Faith W; Murnane, Owen D; Panus, Peter C; Caruthers, Stacy K; Wilkinson, Amy E; Proffitt, Tina M

2004-05-01

338

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

Science.gov (United States)

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

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

2004-01-01

339

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

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[Purpose] To investigate the sensitivity and specificity of a newly developed diagnostic tool, the Amer Dizziness Diagnostic Scale (ADDS), to evaluate and differentially diagnose vestibular disorder and to identify the strengths and weaknesses of the scale and its usefulness in clinical practice. [Subjects and Methods] Two hundred subjects of both genders (72 males, 128 females) aged between 18 to 60 (49.5±7.8) who had a history of vertigo and/or dizziness symptoms for this previous two weeks or less were recruited for the study. All subjects were referred by otolaryngologists, neurologists or family physicians in and around Jeddah, Kingdom of Saudi Arabia. On the first clinic visit, all the patients were evaluated once using the ADDS, following which they underwent routine testing of clinical signs and symptoms, audiometry, and a neurological examination, coupled with tests of Vestibulo-Ocular Reflex function, which often serves as the “gold standard” for determining the probability of a vestibular deficit. [Results] The results show that the ADDS strongly correlated with “true-positive” and “true-negative” responses for determining the probability of a vestibular disorder (r =0.95). A stepwise linear regression was conducted and the results indicate that the ADDS was a significant predictor of “true-positive” and “true-negative” responses in vestibular disorders (R2 =0.90). Approximately 90% of the variability in the vestibular gold standard test was explained by its relationship to the ADDS. Moreover, the ADDS was found to have a sensitivity of 96% and a specificity of 96%. [Conclusion] This study showed that the Amer Dizziness Diagnostic Scale has high sensitivity and specificity and that it can be used as a method of differential diagnosis for patients with vestibular disorders. PMID:25642046

Al Saif, Amer; Alsenany, Samira

2015-01-01

340

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

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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

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

2013-01-01

341

Tratamiento de schwanomas vestibulares esporádicos mediante radiocirugía: Estudio prospectivo de cohorte / Radiosurgical treatment of sporadic vestibular schwannomas: A prospective cohort study  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: Spanish Abstract in spanish 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 radioci [...] rugía 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. Abstract in english 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.

Freddy, Martel V; Rodrigo, Iñiguez S; Daniel, Venencia M; Patricio, Tagle M; Pelayo, Besa D; José, Lorenzoni S.

2008-12-01

342

Correlação entre equilíbrio corporal e capacidade funcional de idosos com disfunções vestibulares crônicas Correlation between the body balance and functional capacity from elderly with chronic vestibular disorders  

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Full Text Available As doenças vestibulares são frequentes na população idosa, resultando, principalmente, em tontura e desequilíbrio corporal, sintomas que podem prejudicar as atividades de vida diária. OBJETIVO: Estudar a correlação entre equilíbrio corporal e a capacidade funcional e a comparação entre risco de queda, ocorrência de queda e a capacidade funcional de idosos com disfunções vestibulares crônicas. MATERIAL E MÉTODO: Forma de estudo transversal, clínico e experimental com 50 idosos, de 60 a 86 anos, com vestibulopatias periféricas crônicas. Estes idosos foram submetidos à avaliação do equilíbrio por meio do Dynamic Gait Index (DGI e à avaliação da capacidade funcional, por meio da Medida de Independência Funcional (MIF. Os dados obtidos foram submetidos ao teste de correlação de Spearman e aos de comparação de Mann-Whitney e Kruskal-Wallis, sendo considerado ?=5% (0,05. RESULTADOS: Verificou-se correlação positiva entre o escore total do DGI e todas as pontuações da MIF, especialmente a MIF total (r=0,447; pVestibular disorders are common among the elderly, mainly resulting in dizziness and imbalance - symptoms which can impact daily routine activities. AIM: To study the correlation between body balance and functional capacity and a comparison of risk of falls, actual falls and the functional capacity of the elderly with chronic vestibular dysfunctions. MATERIALS AND METHODS: A cross-sectional, clinical and experimental study with 50 senior citizens - 60 to 86 years, with chronic peripheral vestibular dysfunction. These participants underwent body balance assessment by the Dynamic Gait Index (DGI and functional capacity assessment by the Functional Independence Measure (FIM. The data was tested using the Spearman correlation and comparison tests, Mann-Whitney and Kruskal- Wallis, being ?=5% (0.05. RESULTS: There was a significant correlation between the total DGI score and all FIM scores, especially the total score (r=0.447; p<0.001 and loss of functional capacity in elderly patients with the highest risk of falling (p<0.001. CONCLUSION: There is a positive correlation between body balance and functional capacity in elderly patients with peripheral vestibular disorders, that is: the better the balance, the better the individual's functional capacity. In addition, a worse functional capacity increases the individual's risk of falling.

Raquel Ferreira de Sousa

2011-12-01

343

Potencial evocado miogênico vestibular (Vemp: avaliação das respostas em indivíduos normais Vestibular evoked myogenic potential (Vemp: evaluation of responses in normal subjects  

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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.

Lilian Felipe

2008-12-01

344

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  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Languages: English, Portuguese Abstract in portuguese 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 comprov [...] ando 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. Abstract in english 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, respecti [...] vely. 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.

Gustavo Duarte Paiva, Ferreira; Maria Cristina Lancia, Cury; José Antônio de, Oliveira; Alessandra Kerli, Manfredi; Hélio, Vannucchi.

2009-04-01

345

Influence of gravitoinertial force on vestibular nystagmus in man observed in a centrifuge  

Science.gov (United States)

The influence of gravity load on the vestibular system in man was investigated in a centrifuge operating on the free swing principle. The vertical vestibular nystagmus induced by acceleration to 3G was analyzed and compared with reference measurements during 1G. Our data indicate that the effects of increased gravity load include a prolonged decay time constant of upbeat nystagmus and a subject-dependent persisting upbeat nystagmus. In an attempt to explain these findings, an extension of the velocity storage model is proposed, with gravity as a second stimulus function in addition to angular acceleration.

Marcus, J. T.; Bles, W.; van Holten, C. R.

346

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

Science.gov (United States)

Sensorimotor changes such as postural and gait instabilities can affect the functional performance of astronauts when they transition across different gravity environments. We are developing a method, based on stochastic resonance (SR), to enhance information transfer by applying non-zero levels of external noise on the vestibular system (vestibular stochastic resonance, VSR). Our previous work has shown the advantageous effects of VSR in a balance task of standing on an unstable surface [1]. This technique to improve detection of vestibular signals uses a stimulus delivery system that provides imperceptibly low levels of white noise-based binaural bipolar electrical stimulation of the vestibular system. The goal of this project is to determine optimal levels of stimulation for SR applications by using a defined vestibular threshold of motion detection. A series of experiments were carried out to determine a robust paradigm to identify a vestibular threshold that can then be used to recommend optimal stimulation levels for sensorimotor adaptability (SA) training applications customized to each crewmember. The amplitude of stimulation to be used in the VSR application has varied across studies in the literature such as 60% of nociceptive stimulus thresholds [2]. We compared subjects' perceptual threshold with that obtained from two measures of body sway. Each test session was 463s long and consisted of several 15s long sinusoidal stimuli, at different current amplitudes (0-2 mA), interspersed with 20-20.5s periods of no stimulation. Subjects sat on a chair with their eyes closed and had to report their perception of motion through a joystick. A force plate underneath the chair recorded medio-lateral shear forces and roll moments. Comparison of threshold of motion detection obtained from joystick data versus body sway suggests that perceptual thresholds were significantly lower. In the balance task, subjects stood on an unstable surface and had to maintain balance, and the stimulation was administered from 20-400% of subjects' vestibular threshold. Optimal stimulation amplitude was determined at which the balance performance was best compared to control (no stimulation). Preliminary results show that, in general, using stimulation amplitudes at 40-60% of perceptual motion threshold significantly improved the balance performance. We hypothesize that VSR stimulation will act synergistically with SA training to improve adaptability by increasing utilization of vestibular information and therefore will help us to optimize and personalize a SA countermeasure prescription. This combination may help to significantly reduce the number of days required to recover functional performance to preflight levels after long-duration spaceflight.

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

2015-01-01

347

Sinusoidal galvanic vestibular stimulation (sGVS) induces a vasovagal response in the rat  

OpenAIRE

Blood pressure (BP) and heart rate (HR) were studied in isoflurane-anesthetized Long-Evans rats during sinusoidal galvanic vestibular stimulation (sGVS) and sinusoidal oscillation in pitch to characterize vestibular influences on autonomic control of BP and HR. sGVS was delivered binaurally via Ag/AgCl needle electrodes inserted over the mastoids at stimulus frequencies 0.008–0.4 Hz. Two processes affecting BP and HR were induced by sGVS: 1) a transient drop in BP (?15–20 mmHg) and HR (...

Cohen, Bernard; Martinelli, Giorgio P.; Ogorodnikov, Dmitri; Xiang, Yongqing; Raphan, Theodore; Holstein, Gay R.; Yakushin, Sergei B.

2011-01-01

348

An overview of congenital/developmental sensorineural hearing loss with emphasis on the vestibular aqueduct syndrome.  

Science.gov (United States)

The evaluation of children with congenital/developmental hearing loss has undergone substantial transformation in recent years. This communication focuses on the most common cause of this type of hearing loss for which there are imaging findings: the vestibular aqueduct syndrome. The normal anatomy of the vestibular aqueduct is discussed in detail. The cochlear aqueduct with which it is commonly confused is also discussed. An overview of other congenital defects and abnormal middle/inner ear communications is also included. A brief discussion of cochlear implants is also included for completeness. PMID:15497615

Swartz, Joel D

2004-08-01

349

Disrupted functional connectivity of the default mode network due to acute vestibular deficit  

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Here, we employ functional magnetic resonance imaging (fMRI in the resting state to investigate changes in the functional connectivity between the DMN and task-positive networks, in a longitudinal design combined with measurements of caloric function. We demonstrate an initially disturbed connectedness of the DMN after vestibular neuritis. We hypothesize that the disturbed connectivity between the default mode network and particular parts of the task-positive network might be related to a sustained utilization of processing capacity by diverging sensory information. The current results provide some insights into mechanisms of central compensation following an acute vestibular deficit and the importance of the DMN in this disease.

Carsten M. Klingner

2014-01-01

350

The caloric vestibular nystagmus during short lasting microgravity  

Science.gov (United States)

In human subjects the caloric vestibular test was conducted during parabolic flight. The ear irrigation was performed from 35 secs. till 5 secs. before the onset of microgravity. Nystagmography covered a 10-minutes period, including three parabolic manoeuvres of the aircraft. a. The slow phase velocity (SPV) of the caloric nystagmus increased proportionally with the value of the g-force. Introduction of microgravity induced an exponential decrease of the SPV decay. b. The nystagmus disappeared completely in microgravity, but SPV decay showed a specific time constant. c. The averaged time constant values of the caloric nystagmus SPV decay after sudden onset of microgravity and the averaged time constant of the SPV decay following a sudden stop after sustained rotation during 0-g appeared to be on the same level (10.2 s. and 10.6 s.). d. These two averaged time constant values obtained during shortlasting microgravity proved to be on a lower level than those time constants (15.5 secs.; 15.9 secs.) found in ground-based conditions. e. Because of the similarities in the characteristics of both SPV decay's and their accompanying time constants, a common working mechanism of cupular stimulation is likely. Most probably a fluid movement (or pressure) provokes a cupula deflexion followed by a cupula reflexion, either caused by a sudden stop after a sustained rotation or by a sudden onset of microgravity after g-load calorization. The present results support the Bárány convection theory with regard the endolymph stimulatory properties following the caloric test.

Oosterveld, W. J.; de Jong, H. A. A.; Kortschot, H. W.

351

Asymmetry in vestibular responses to cross-coupled stimulus.  

Science.gov (United States)

Head turns performed while rotating about another axis result in a cross-coupled stimulus (CCS) to the vestibular system. The CCS causes a tumbling sensation, and the magnitude of the tumbling sensation is dependent on the type of head turn (HT) that is performed. Asymmetric CCS responses to different rotational directions are widely acknowledged, yet poorly understood. The objective of this study was to: 1) correctly describe the asymmetries in responses to different configurations of CCS stimulation and 2) test two previously proposed hypotheses for explaining the asymmetries, dominant direction, and dominant end position. The dominant direction hypothesis states that the tumbling sensations evoked by the CCS will be more intense for certain directions of the tumbling sensation than for others. The dominant end position hypothesis states that head turns ending in the nose-up position result in more intense sensations than those ending on the side positions. Subjects performed four types of 60-degree yaw head turns while lying horizontally on a centrifuge. Subjects were either supine or prone, while rotating clockwise or counterclockwise. Three experimental conditions were tested: clockwise supine (n = 33); counterclockwise supine (n = 10); and clockwise prone (n = 10). Subjective tumbling intensity scores were recorded for each head turn. Head turns to the left are dominant for clockwise supine centrifugation (P centrifugation (P = 0.0020), matching what is expected from previous studies. However, for prone centrifugation, head turns to the left are more intense than head turns to the right (P = 0.0078), refuting the dominant direction hypothesis. The dominant end position effect is small in magnitude and cannot by itself explain the asymmetries. For every test condition, there is a dominant direction, but the dominant direction is not just a function of the HT and centrifuge rotation directions, instead it is also dependent on the subject's orientation on the centrifuge. An alternative perceived danger hypothesis that matches the data from all three experiments is proposed. PMID:21336829

Mateus, Jaime; Cañizales, Jorge; Hearn, Andrew N; Young, Laurence R

2011-04-01

352

Morphological evidence for local microcircuits in rat vestibular maculae  

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Previous studies suggested that intramacular, unmyelinated segments of vestibular afferent nerve fibers and their large afferent endings (calyces) on type I hair cells branch. Many of the branches (processes) contain vesicles and are presynaptic to type II hair cells, other processes, intramacular nerve fibers, and calyces. This study used serial section transmission electron microscopy and three-dimensional reconstruction methods to document the origins and distributions of presynaptic processes of afferents in the medial part of the adult rat utricular macula. The ultrastructural research focused on presynaptic processes whose origin and termination could be observed in a single micrograph. Results showed that calyces had 1) vesiculated, spine-like processes that invaginated type I cells and 2) other, elongate processes that ended on type II cells pre- as well as postsynaptically. Intramacular, unmyelinated segments of afferent nerve fibers gave origin to branches that were presynaptic to type II cells, calyces, calyceal processes, and other nerve fibers in the macula. Synapses with type II cells occurred opposite subsynaptic cisternae (C synapses); all other synapses were asymmetric. Vesicles were pleomorphic but were differentially distributed according to process origin. Small, clear-centered vesicles, approximately 40-60 nm in diameter, predominated in processes origin