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1

Vestibular efferent neurons project to the flocculus  

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A bilateral projection from the vestibular efferent neurons, located dorsal to the genu of the facial nerve, to the cerebellar flocculus and ventral paraflocculus was demonstrated. Efferent neurons were double-labeled by the unilateral injections of separate retrograde tracers into the labyrinth and into the floccular and ventral parafloccular lobules. Efferent neurons were found with double retrograde tracer labeling both ipsilateral and contralateral to the sites of injection. No double labeling was found when using a fluorescent tracer with non-fluorescent tracers such as horseradish peroxidase (HRP) or biotinylated dextran amine (BDA), but large percentages of efferent neurons were found to be double labeled when using two fluorescent substances including: fluorogold, microruby dextran amine, or rhodamine labeled latex beads. These data suggest a potential role for vestibular efferent neurons in modulating the dynamics of the vestibulo-ocular reflex (VOR) during normal and adaptive conditions.

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

2001-01-01

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Stereology of Calretinin-immunopositive Neurons in Scarpa's Ganglion of Cerebellar and Vestibular Mutant Mice  

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The primary vestibular afferents (PVA) of bipolar neurons (BN) in the vestibular ganglion (VG) connect the peripheral vestibular hair cell sensors of the labyrinth with the vestibular nuclei and the cerebellum in the CNS. Thus, damage to PVA may cause symptoms characteristic for central as well as for peripheral vestibular disorders, BNs and PVA have been shown to outlive extensive damage or loss of vestibular end organs as well as central target deprivation for a long time and in many instan...

Cabraja, Mario

2010-01-01

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Convergence of limb, visceral, and vertical semicircular canal or otolith inputs onto vestibular nucleus neurons  

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The major goal of this study was to determine the patterns of convergence of non-labyrinthine inputs from the limbs and viscera onto vestibular nucleus neurons receiving signals from vertical semicircular canals or otolith organs. A secondary aim was to ascertain whether the effects of non-labyrinthine inputs on the activity of vestibular nucleus neurons is affected by bilateral peripheral vestibular lesions. The majority (72%) of vestibular nucleus neurons in labyrinth-intact animals whose firing was modulated by vertical rotations responded to electrical stimulation of limb and/or visceral nerves. The activity of even more vestibular nucleus neurons (93%) was affected by limb or visceral nerve stimulation in chronically labyrinthectomized preparations. Some neurons received non-labyrinthine inputs from a variety of peripheral sources, including antagonist muscles acting at the same joint, whereas others received inputs from more limited sources. There was no apparent relationship between the spatial and dynamic properties of a neuron's responses to tilts in vertical planes and the non-labyrinthine inputs that it received. These data suggest that non-labyrinthine inputs elicited during movement will modulate the processing of information by the central vestibular system, and may contribute to the recovery of spontaneous activity of vestibular nucleus neurons following peripheral vestibular lesions. Furthermore, some vestibular nucleus neurons with non-labyrinthine inputs may be activated only during particular behaviors that elicit a specific combination of limb and visceral inputs.

Jian, B. J.; Shintani, T.; Emanuel, B. A.; Yates, B. J.

2002-01-01

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Intrinsic physiology of identified neurons in the prepositus hypoglossi and medial vestibular nuclei  

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Signal processing in the vestibular system is influenced by the intrinsic physiological properties of neurons that differ in neurotransmitters and circuit connections. Do membrane and firing properties differ across functionally distinct cell types? This study examines the intrinsic physiology of neurons in the medial vestibular nucleus (MVN) and nucleus prepositus hypoglossi (NPH) which express different neurotransmitters and have distinct axonal projections. NPH neurons expressing fluoresce...

Kolkman, Kristine E.; Moghadam, Setareh H.; Lac, Sascha Du

2011-01-01

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

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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

6

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

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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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The normal distribution and projections of constitutive NADPH-d/NOS neurons in the brainstem vestibular complex of the rat.  

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The vestibular system is a highly conserved sensory system in vertebrates that is largely responsible for maintenance of one's orientation in space, posture, and balance and for visual fixation of objects during motion. In light of the considerable literature indicating an involvement of nitric oxide (NO) in sensory systems, it is important to determine whether NO is associated with vestibular pathways. To study the relationship of NO to vestibular pathways, we first examined the normal distribution of constitutive NADPH-diaphorase (NADPH-d), a marker for nitric oxide synthase (NOS), in the vestibular complex (VC) and then examined its association with selected vestibular projection neurons. Survey of the four major vestibular nuclei revealed that only the medial vestibular nucleus contained significant numbers of perikarya stained for NADPH-d/NOS. By contrast, all the vestibular nuclei contained a network of fine processes that stained positive for NADPH-d, although the density of this network varied among the individual nuclei. To determine whether NADPH-d/NOS neurons project to vestibular efferent targets, injections of the retrograde tracer Fluoro-Gold were made into known targets of second-order vestibular neurons. Vestibular neurons containing constitutive NADPH-d/NOS were found to project predominantly to the oculomotor nucleus. A small number of neurons also participate in vestibulothalamic and intrinsic vestibular connections. These results indicate that NADPH-d/NOS neurons are prevalent in the MVN and that a subpopulation of these neurons project to the oculomotor complex. Nitric oxide is probably released locally from axons located throughout the vestibular complex but may play a particularly important role in vestibulo-ocular pathways. PMID:10940945

Saxon, D W; Beitz, A J

2000-09-11

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

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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 ...

Cf, Kwok Jessica; Yuen Ying-Lai; Lau Wai-Kit; Zhang Fu-Xing; Fawcett James W; Chan Ying-Shing; Ky, Shum Daisy

2012-01-01

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

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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

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

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

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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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Inputs from regularly and irregularly discharging vestibular nerve afferents to secondary neurons in squirrel monkey vestibular nuclei. III. Correlation with vestibulospinal and vestibuloocular output pathways  

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1. A previous study measured the relative contributions made by regularly and irregularly discharging afferents to the monosynaptic vestibular nerve (Vi) input of individual secondary neurons located in and around the superior vestibular nucleus of barbiturate-anesthetized squirrel monkeys. Here, the analysis is extended to more caudal regions of the vestibular nuclei, which are a major source of both vestibuloocular and vestibulospinal pathways. As in the previous study, antidromic stimulation techniques are used to classify secondary neurons as oculomotor or spinal projecting. In addition, spinal-projecting neurons are distinguished by their descending pathways, their termination levels in the spinal cord, and their collateral projections to the IIIrd nucleus. 2. Monosynaptic excitatory postsynaptic potentials (EPSPs) were recorded intracellularly from secondary neurons as shocks of increasing strength were applied to Vi. Shocks were normalized in terms of the threshold (T) required to evoke field potentials in the vestibular nuclei. As shown previously, the relative contribution of irregular afferents to the total monosynaptic Vi input of each secondary neuron can be expressed as a %I index, the ratio (x100) of the relative sizes of the EPSPs evoked by shocks of 4 x T and 16 x T. 3. Antidromic stimulation was used to type secondary neurons as 1) medial vestibulospinal tract (MVST) cells projecting to spinal segments C1 or C6; 2) lateral vestibulospinal tract (LVST) cells projecting to C1, C6; or L1; 3) vestibulooculo-collic (VOC) cells projecting both to the IIIrd nucleus and by way of the MVST to C1 or C6; and 4) vestibuloocular (VOR) neurons projecting to the IIIrd nucleus but not to the spinal cord. Most of the neurons were located in the lateral vestibular nucleus (LV), including its dorsal (dLV) and ventral (vLV) divisions, and adjacent parts of the medial (MV) and descending nuclei (DV). Cells receiving quite different proportions of their direct inputs from regular and irregular afferents were intermingled in all regions explored. 4. LVST neurons are restricted to LV and DV and show a somatotopic organization. Those destined for the cervical and thoracic cord come from vLV, from a transition zone between vLV and DV, and to a lesser extent from dLV. Lumbar-projecting neurons are located more dorsally in dLV and more caudally in DV. MVST neurons reside in MV and in the vLV-DV transition zone.(ABSTRACT TRUNCATED AT 400 WORDS).

Boyle, R.; Goldberg, J. M.; Highstein, S. M.

1992-01-01

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

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

MathieuBeraneck

2012-02-01

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Downbeat nystagmus associated with damage to the medial longitudinal fasciculus of the pons: a vestibular balance control mechanism via the lower brainstem paramedian tract neurons.  

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The paramedian tract (PMT) neurons, a group of neurons associated with eye movement that project into the cerebellar flocculus, are present in or near the medial longitudinal fasciculus (MLF) in the paramedian region of the lower brainstem. A 66-year-old man with multiple sclerosis in whom downbeat nystagmus appeared along with right MLF syndrome due to a unilateral pontomedullary lesion is described. In light of these findings, a possible schema for the vestibular balance control mechanism circuit of the PMT neurons via the flocculus is presented. Damage to the PMT neurons impaired the elective inhibitory control mechanism of the anterior semicircular canal neural pathway by the flocculus. This resulted in the appearance of anterior semicircular canal-dominant vestibular imbalance and the formation of downbeat nystagmus. From the pathogenesis of this vertical vestibular nystagmus, the action of the PMT neurons in the vestibular eye movement neuronal pathway to maintain vestibular balance was conjectured to be as follows. PMT neurons transmit vestibular information from the anterior semicircular canals to the cerebellum, forming a cerebellum/brainstem feedback loop. Vestibular information from that loop is integrated in the cerebellum, inhibiting only the anterior semicircular canal neuronal pathway via the flocculus and controlling vestibular balance. PMID:23510567

Nakamagoe, Kiyotaka; Fujizuka, Natsu; Koganezawa, Tadachika; Yamaguchi, Tetsuto; Tamaoka, Akira

2013-05-15

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

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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

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ELECTROPHYSIOLOGICAL PROPERTIES OF MORPHOLOGICALLY-IDENTIFIED MEDIAL VESTIBULAR NUCLEUS NEURONS PROJECTING TO THE ABDUCENS NUCLEUS IN THE CHICK EMBRYO  

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Neurons in the medial vestibular nucleus (MVN) show a wide range of axonal projection pathways, intrinsic firing properties, and responses to head movements. To determine whether MVN neurons participating in the vestibulocular reflexes (VOR) have distinctive electrophysiological properties related to their output pathways, a new preparation was devised using transverse brain slices containing the chicken MVN and abducens nucleus. Biocytin Alexa Fluor was injected extracellularly into the abdu...

Gottesman-davis, Adria; Shao, Mei; Hirsch, June C.; Peusner, Kenna D.

2011-01-01

18

Vestibular Neuronitis  

Science.gov (United States)

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

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Frequency-Dependent Spatiotemporal Tuning Properties of Non–Eye Movement Related Vestibular Neurons to Three-Dimensional Translations in Squirrel Monkeys  

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Responses of vestibular-only translation sensitive (VOTS) neurons in vestibular nuclei of two squirrel monkeys were studied at multiple frequencies to three-dimensional translations and rotations. A novel frequency-dependent spatiotemporal analysis examined in each neuron whether complex models, with unrestricted response dynamics in three-dimensional (3D) space, provided significantly better fits than restricted models following simple, cosine rule. Subsequently, the statistically selected o...

Chen-huang, Chiju; Peterson, Barry W.

2010-01-01

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[Excitatory effects of glucocorticoids on neuronal activity in the medial vestibular nucleus--mediation by glucocorticoid receptor on the membrane].  

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Although glucocorticoids are sometimes used for the treatment of vertigo in certain disorders such as Meniere's disease, the mechanism underlying anti-vertigo effect remains unknown. The present study was performed to examine the effects of a glucocorticoid, dexamethasone, on neuronal activity in the medial vestibular nucleus (MVN) to determine whether or not the drug acts directly on the MVN neuron using alpha-chloralose-anesthetized cats which were fixed in a stereotaxic instrument placed on a turn-table. Single neuronal activities in the MVN were extracellularly recorded with a glass-insulated silver wire microelectrode attached along a seven-barreled micropipette. Each pipette was filled with dexamethasone phosphate (0.1 M), monosodium glutamate (1 M), glutamic acid diethylester (GDEE) (0.05 M: a non-selective glutamate receptor antagonist), CoCl2, (0.1 M: a non-specific calcium channel blocker), RU38486 (0.01 M: glucocorticoid receptor antagonist) or potassium canrenoate (0.1 M: a mineralo-cortical receptor antagonist). These chemicals were microiontophoretically applied to the immediate vicinity of the target neuron being recorded. The effects of the drugs were examined on type I neurons which were identified according to responses to rotation: the neuron showed an increase and a decrease in firing with ipsilateral and contralateral rotation to the recording site, respectively. Microiontophoretically applied dexamethasone (50-200 nA) dose-dependently increased spontaneous firing of MVN neurons. However iontophoretic application of GDEE did not affect the dexamethasone-induced increase in firing of the MVN neurons but inhibited glutamate- and rotation-induced firing. Microiontophoretically applied Co2+ did not affect dexamethasone-, glutamate- and rotation-induced firing. However, dexamethasone-induced firing was dose-dependently suppressed by iontophoretic RU38486, but not by canrenoate. Then a microdialysis study using alpha-chloralose-anesthetized cats was performed to determine whether or not dexamethasone affects the release of glutamate from vestibular nerve terminals. The microdialysis probe (CMA/10, 2 mm) was inserted into the MVN and perfused with Ringer solution at 2 ml/min. Samples were collected at 10-min intervals. Endogenous glutamate was measured using the HPLC-ECD method. When repetitive stimuli (200 microseconds duration, 0.5 mA and 5 Hz) were given to the vestibular nerve for 10 min, an increase in the release of glutamate was observed. Dexamethasone did not produce spontaneous or stimulation-induced release of glutamate. These results suggest that dexamethasone acts directly on the MVN neuron to excite neuronal activity through glucocorticoid receptors on neuron membranes, but the excitation is not due to the release of glutamate. PMID:7911523

Yamanaka, T

1994-05-01

 
 
 
 
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Frequency-dependent spatiotemporal tuning properties of non-eye movement related vestibular neurons to three-dimensional translations in squirrel monkeys.  

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Responses of vestibular-only translation sensitive (VOTS) neurons in vestibular nuclei of two squirrel monkeys were studied at multiple frequencies to three-dimensional translations and rotations. A novel frequency-dependent spatiotemporal analysis examined in each neuron whether complex models, with unrestricted response dynamics in three-dimensional (3D) space, provided significantly better fits than restricted models following simple, cosine rule. Subsequently, the statistically selected optimal model was used to predict the maximum translation direction, expressed as a unitary vector, Vt(max), and its associated sensitivity and phase across frequencies. Simple models were sufficient to quantify the 3D translational responses of 66% of neurons. Most VOTS neurons, complex or simple, exhibited flat-gain or low-pass response dynamics. The Vt(max) of simple neurons was fixed, whereas that of complex neurons changed with frequency. The spatial distribution of Vt(max) in simple neurons, which fell within 30 degrees of either the horizontal plane or/and the sagittal plane, was closely aligned with Vt(max) of vestibular afferents. In contrast, the frequency-dependent Vt(max) of most complex neurons migrated from the dorsoventral axis at higher frequency toward the horizontal plane, especially the interaural axis, at lower frequency. When the maximum rotation direction was estimated from responses of the same VOTS neurons to 1.2 Hz yaw, pitch, and roll rotations, complex neurons were more likely to respond to rotations activating vertical canals. Responses to 0.15-0.3 Hz linear accelerations produced by inertial or gravitational forces were indistinguishable in most complex neurons but significantly different in most simple neurons. These observations suggest that simple and complex VOTS neurons constitute distinctive vestibular pathways where complex neurons, exhibiting a novel spatiotemporal filtering mechanism in processing otolith-related signals, are well suited to drive tilt-related responses, whereas simple neurons probably mediate pure translation related responses. PMID:20375245

Chen-Huang, Chiju; Peterson, Barry W

2010-06-01

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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

23

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

24

Implantes vestibulares / Vestibular prosthesis  

Scientific Electronic Library Online (English)

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

25

Vestibular neuritis.  

Science.gov (United States)

Vestibular neuritis is the most common cause of acute spontaneous vertigo. Vestibular neuritis is ascribed to acute unilateral loss of vestibular function, probably due to reactivation of herpes simplex virus in the vestibular ganglia. The diagnostic hallmarks of vestibular neuritis are spontaneous horizontal-torsional nystagmus beating away from the lesion side, abnormal head impulse test for the involved semicircular canals, ipsilesional caloric paresis, decreased responses of vestibular-evoked myogenic potentials during stimulation of the affected ear, and unsteadiness with a falling tendency toward the lesion side. Vestibular neuritis preferentially involves the superior vestibular labyrinth and its afferents. Accordingly, the function of the posterior semicircular canal and saccule, which constitute the inferior vestibular labyrinth, is mostly spared in vestibular neuritis. However, because the rare subtype of inferior vestibular neuritis lacks the typical features of vestibular neuritis, it may be misdiagnosed as a central vestibular disorder. Even in the patient with the typical pattern of spontaneous nystagmus observed in vestibular neuritis, brain imaging is indicated when the patient has unprecedented headache, negative head impulse test, severe unsteadiness, or no recovery within 1 to 2 days. Symptomatic medication is indicated only during the acute phase to relieve the vertigo and nausea/vomiting. Vestibular rehabilitation hastens the recovery. The efficacy of topical and systemic steroids requires further validation. PMID:24057821

Jeong, Seong-Hae; Kim, Hyo-Jung; Kim, Ji-Soo

2013-07-01

26

Uptake of gentamicin by vestibular efferent neurons and superior olivary complex after transtympanic administration in guinea pigs  

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Transtympanic administration of gentamicin is a widely accepted and effective approach for treating patients with intractable vertigo. Previous studies have demonstrated the uptake, distribution and effects of gentamicin in peripheral vestibular and cochlear structures after transtympanic injection. However, little is known about whether transtympanically administered gentamicin is trafficked into more central auditory and vestibular structures and its effect on these structures. In this stud...

Zhang, Yi-bo; Zhang, Ru; Zhang, Wei-feng; Steyger, Peter S.; Dai, Chun-fu

2011-01-01

27

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

28

Activation of ?-opioid receptors inhibits calcium-currents in the vestibular afferent neurons of the rat through a cAMP dependent mechanism.  

Science.gov (United States)

Opioid receptors are expressed in the vestibular endorgans (afferent neurons and hair cells) and are activated by the efferent system, which modulates the discharge of action potentials in vestibular afferent neurons (VANs). In mammals, VANs mainly express the ? opioid-receptor, but the function of this receptors activation and the cellular mechanisms by which they exert their actions in these neurons are poorly studied. To determine the actions of ? opioid receptor (MOR) and cell signaling mechanisms in VANs, we made perforated patch-clamp recordings of VANs that were obtained from postnatal days 7 to 10 (P7-10) rats and then maintained in primary culture. The MOR agonist [D-Ala(2), N-Me-Phe(4), Gly(5)-ol]-enkephalin (DAMGO) inhibited the total voltage-gated outward current; this effect was prevented by the perfusion of a Ca(2+)-free extracellular solution. We then studied the voltage-gated calcium current (Ica) and found that DAMGO Met-enkephalin or endomorphin-1 inhibited the ICa in a dose-response fashion. The effects of DAMGO were prevented by the MOR antagonist (CTAP) or by pertussis toxin (PTX). The use of specific calcium channel blockers showed that MOR activation inhibited T-, L- and N-type ICa. The use of various enzyme activators and inhibitors and of cAMP analogs allowed us to demonstrate that the MOR acts through a cAMP dependent signaling mechanism. In current clamp experiments, MOR activation increased the duration and decreased the amplitude of the action potentials and modulated the discharge produced by current injection. Pre-incubation with PTX occluded MOR activation effect. We conclude that MOR activation inhibits the T-, L- and N-type ICa through activation of a G?i/o protein that involves a decrease in AC-cAMP-PKA activity. The modulation of ICa may have an impact on the synaptic integration, excitability, and neurotransmitter release from VANs. PMID:24734002

Seseña, Emmanuel; Vega, Rosario; Soto, Enrique

2014-01-01

29

Procedures for restoring vestibular disorders  

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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

30

Vestibular migraine.  

Science.gov (United States)

Vestibular migraine presents with attacks of spontaneous or positional vertigo, head motion-induced vertigo, and visual vertigo lasting 5 minutes to 3 days. The recent classification of vestibular migraine, jointly proposed by the Bárány Society and the International Headache Society, allows identification of vestibular migraine and probable vestibular migraine based on explicit criteria. The diagnosis is based on symptom type, severity and duration, a history of migraine, temporal association of migraine symptoms with vertigo attacks, and exclusion of other causes. Because headache is often absent during acute attacks, other migraine features such as photophobia or auras have to be specifically inquired about. During acute attacks, one may find central spontaneous or positional nystagmus, and less commonly, unilateral vestibular hypofunction. In the symptom-free interval, vestibular testing adds little to the diagnosis as findings are mostly minor and nonspecific. The pathophysiology of vestibular migraine is unknown, but several mechanisms link the trigeminal system, which is activated during migraine attacks, and the vestibular system. Treatment includes antiemetics for severe acute attacks, pharmacological migraine prophylaxis, and lifestyle changes. PMID:24057824

Lempert, Thomas

2013-07-01

31

Ultrastructure of projections to the oculomotor nucleus and inferior olive from vestibular and cerebellar neurons involved in compensatory eye movements  

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Early in the evolution of vertebrates eye movements were strictly primitive reflexes that were predominantly controlled by vestibular and visual sensory stimuli. Later during phylogeny, along with the development of the fovea of the retina, vertebrates acquired the ability to make voluntary eye movements (BOttner and BUttner-Eonever, 1988). In short, five types of eye movements can be distinguished. The first two are slow eye movements that compensate for movements of the head ...

Wentzel, P. R.

1998-01-01

32

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

33

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

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

KennaPeusner

2012-02-01

34

Vestibular Migraine  

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Full Text Available The co-occurrence between migraine and vertigo has been noticed for a long time ago. In recent years, however, growing numbers of epidemiological and clinical studies have definitely shown the significant relation between these two diseases. Recently, the term “vestibular migraine” is used commonly in studies. Vestibular migraine has taken place in appendix in the latest International Headache Society Classification. In this review, epidemiology, clinical features, diagnostic criteria and treatment of vesti-bular migraine will be discussed. (Arc­hi­ves of Neu­ropsy­chi­atry 2012; 49: 56-59Conflict of interest: The authors reported no conflict of interest related to this article

Gülden AKDAL

2013-09-01

35

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

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We recorded from rostral vestibular (VN) and rostral fastigial nuclei (FN) neurons that did not respond to eye movements during three-dimensional (3D) vestibular and optokinetic stimulation (OKS). The majority of neurons in both areas (76 and 69% in VN and FN, respectively) responded during both rotational and translational motion. Preferred directions scattered throughout 3D space for translation but showed some preference for pitch/roll over yaw for rotation. VN/FN neurons were also tested ...

Bryan, Ayanna S.; Angelaki, Dora E.

2008-01-01

36

Activation of µ-opioid receptors inhibits calcium-currents in the vestibular afferent neurons of the rat through a cAMP dependent mechanism  

Directory of Open Access Journals (Sweden)

Full Text Available Opioid receptors are expressed in the vestibular endorgans (afferent neurons and hair cells and are activated by the efferent system, which modulates the discharge of action potentials in the vestibular afferent neurons (VANs. In mammals, the VANs mainly express the µ opioid-receptor, but the function of the opioid receptor activation and the cellular mechanisms by which they exert their actions in these neurons are poorly studied. To determine the actions of the µ opioid receptor (MOR and the cell signaling mechanisms in the VANs, we made perforated patch-clamp recordings of VANs that were obtained from postnatal days 7 to 10 (P7-10 rats and then maintained in primary culture. The MOR agonist [D-Ala2, N-Me-Phe4, Gly5-ol]-enkephalin (DAMGO inhibited the total voltage-gated outward current; this effect was prevented by the perfusion of a Ca2+-free extracellular solution. We then studied the voltage-gated calcium current (Ica and found that DAMGO Met-enkephalin or endomorphine-1 inhibited the ICa in a dose-response fashion. The effects of DAMGO were prevented by the MOR antagonist (CTAP or by the pertussis toxin (PTX. The use of specific calcium channel blockers showed that MOR activation inhibited the T-, L- and N-type ICa. The use of various enzyme activators and inhibitors and of cAMP analogs allowed us to demonstrate that the MOR acts through a cAMP dependent signaling mechanism. In the current clamp experiments, MOR activation increased the duration and decreased the amplitude of the action potentials and modulated the discharge to the current injection. Pre-incubation with PTX occluded all MOR activation effects observed in the current clamp experiments.\tWe conclude that MOR activation inhibits the T-, L- and N-type ICa through the activation of a G?i/o protein that involves a decrease in AC-cAMP-PKA activity. The modulation of ICa may have an impact on the synaptic integration, excitability and neurotransmitter release from the VANs.

Enrique Soto

2014-03-01

37

The thalamocortical vestibular system in animals and humans.  

Science.gov (United States)

The vestibular system provides the brain with sensory signals about three-dimensional head rotations and translations. These signals are important for postural and oculomotor control, as well as for spatial and bodily perception and cognition, and they are subtended by pathways running from the vestibular nuclei to the thalamus, cerebellum and the "vestibular cortex." The present review summarizes current knowledge on the anatomy of the thalamocortical vestibular system and discusses data from electrophysiology and neuroanatomy in animals by comparing them with data from neuroimagery and neurology in humans. Multiple thalamic nuclei are involved in vestibular processing, including the ventroposterior complex, the ventroanterior-ventrolateral complex, the intralaminar nuclei and the posterior nuclear group (medial and lateral geniculate nuclei, pulvinar). These nuclei contain multisensory neurons that process and relay vestibular, proprioceptive and visual signals to the vestibular cortex. In non-human primates, the parieto-insular vestibular cortex (PIVC) has been proposed as the core vestibular region. Yet, vestibular responses have also been recorded in the somatosensory cortex (area 2v, 3av), intraparietal sulcus, posterior parietal cortex (area 7), area MST, frontal cortex, cingulum and hippocampus. We analyze the location of the corresponding regions in humans, and especially the human PIVC, by reviewing neuroimaging and clinical work. The widespread vestibular projections to the multimodal human PIVC, somatosensory cortex, area MST, intraparietal sulcus and hippocampus explain the large influence of vestibular signals on self-motion perception, spatial navigation, internal models of gravity, one's body perception and bodily self-consciousness. PMID:21223979

Lopez, Christophe; Blanke, Olaf

2011-06-24

38

Towards a neuromorphic vestibular system.  

Science.gov (United States)

The vestibular system plays a crucial role in the sense of balance and spatial orientation in mammals. It is a sensory system that detects both rotational and translational motion of the head, via its semicircular canals and otoliths respectively. In this work, we propose a real-time hardware model of an artificial vestibular system, implemented using a custom neuromorphic Very Large Scale Integration (VLSI) multi-neuron chip interfaced to a commercial Inertial Measurement Unit (IMU). The artificial vestibular system is realized with spiking neurons that reproduce the responses of biological hair cells present in the real semicircular canals and otholitic organs. We demonstrate the real-time performance of the hybrid analog-digital system and characterize its response properties, presenting measurements of a successful encoding of angular velocities as well as linear accelerations. As an application, we realized a novel implementation of a recurrent integrator network capable of keeping track of the current angular position. The experimental results provided validate the hardware implementation via comparisons with a detailed computational neuroscience model. In addition to being an ideal tool for developing bio-inspired robotic technologies, this work provides a basis for developing a complete low-power neuromorphic vestibular system which integrates the hardware model of the neural signal processing pathway described with custom bio-mimetic gyroscopic sensors, exploiting neuromorphic principles in both mechanical and electronic aspects. PMID:25314706

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

2014-10-01

39

Vestibular Schwannoma  

Science.gov (United States)

Vestibular schwannomas (VS) commonly are limited to the internal auditory canal (IAC) and cerebellopontine angle. Extension to labyrinth is less frequent, and involvement of the middle ear or external acoustic canal (EAC) is very rare. In this report we present the case of a 41-year-old woman with a VS, which recurred after a previous surgical removal 4 years before. The tumor involved the IAC, cochlea, vestibule, semicircular canals, cavum tympani, mastoid cells, and EAC. Total removal of the tumor was achieved by a transotic approach, without neurological sequela. ImagesFigure 1Figure 2Figure 3Figure 4 PMID:17171129

Carreño, Marcos; Llorente, José L.; Suárez, Carlos

1999-01-01

40

Vestibular responses to sound.  

Science.gov (United States)

Research into vestibular responses to sound has evolved in four stages. The first, largely the work of Tullio in the 1920s, involved inspection of the eye, head, and postural responses to sound of alert animals with surgical fenestrae into various parts of the bony labyrinth. The second, begun in 1964 by Bickford and his group and continued by our group and then by others in the last 10 years, involves the measurement of evoked myogenic potentials to air-conducted and bone-conducted clicks and tones in normal humans. The third, begun by Mikaelian at about the same time as Bickford and continued by McCue, our group, and others, involves electrophysiological recordings of primary vestibular afferent neuron responses to sound in anesthetized animals. The fourth involves measurements of vestibulo-ocular responses to sound in humans with the Tullio phenomenon. It was begun by Minor and his group in 1998 with the observation that sound-induced nystagmus in humans, the Tullio phenomenon, aligned with the rotation axis of the superior semicircular canal. They then showed a defect in the temporal bone between the apex of the superior semicircular canal and the middle cranial fossa, which was the cause of most, if not all, cases of sound-induced nystagmus. Here some of the key observations made in each of these four stages are reviewed. PMID:15826961

Halmagyi, G M; Curthoys, I S; Colebatch, J G; Aw, S T

2005-04-01

 
 
 
 
41

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

42

Large vestibular aqueduct syndrome.  

Science.gov (United States)

Large Vestibular Aqueduct Syndrome is a congenital malformation of the temporal bone characterised by early onset of sensorineural hearing loss and vestibular disturbance. Familial large vestibular aqueduct syndrome suggests autosomal recessive or X-linked inheritance and accounts for non-syndromic sensorineural hearing loss in these patients. PMID:16570713

Dipak, S; Prepageran, N; Sazila, A S; Rahmat, O; Raman, R

2005-10-01

43

Vestibular migraine : Diagnostic criteria  

DEFF Research Database (Denmark)

This paper presents diagnostic criteria for vestibular migraine, jointly formulated by the Committee for Classification of Vestibular Disorders of the Bárány Society and the Migraine Classification Subcommittee of the International Headache Society (IHS). The classification includes vestibular migraine and probable vestibular migraine. Vestibular migraine will appear in an appendix of the third edition of the International Classification of Headache Disorders (ICHD) as a first step for new entities, in accordance with the usual IHS procedures. Probable vestibular migraine may be included in a later version of the ICHD, when further evidence has been accumulated. The diagnosis of vestibular migraine is based on recurrent vestibular symptoms, a history of migraine, a temporal association between vestibular symptoms and migraine symptoms and exclusion of other causes of vestibular symptoms. Symptoms that qualify for a diagnosis of vestibular migraine include various types of vertigo as well as head motion-induced dizziness with nausea. Symptoms must be of moderate or severe intensity. Duration of acute episodes is limited to a window of between 5 minutes and 72 hours.

Lempert, Thomas; Olesen, Jes

2012-01-01

44

Differential central projections of vestibular afferents in pigeons  

Science.gov (United States)

The question of whether a differential distribution of vestibular afferent information to central nuclear neurons is present in pigeons was studied using neural tracer compounds. Discrete tracing of afferent fibers innervating the individual semicircular canal and otolith organs was produced by sectioning individual branches of the vestibular nerve that innervate the different receptor organs and applying crystals of horseradish peroxidase, or a horseradish peroxidase/cholera toxin mixture, or a biocytin compound for neuronal uptake and transport. Afferent fibers and their terminal distributions within the brainstem and cerebellum were visualized subsequently. Discrete areas in the pigeon central nervous system that receive primary vestibular input include the superior, dorsal lateral, ventral lateral, medial, descending, and tangential vestibular nuclei; the A and B groups; the intermediate, medial, and lateral cerebellar nuclei; and the nodulus, the uvula, and the paraflocculus. Generally, the vertical canal afferents projected heavily to medial regions in the superior and descending vestibular nuclei as well as the A group. Vertical canal projections to the medial and lateral vestibular nuclei were observed but were less prominent. Horizontal canal projections to the superior and descending vestibular nuclei were much more centrally located than those of the vertical canals. A more substantial projection to the medial and lateral vestibular nuclei was seen with horizontal canal afferents compared to vertical canal fibers. Afferents innervating the utricle and saccule terminated generally in the lateral regions of all vestibular nuclei in areas that were separate from the projections of the semicircular canals. In addition, utricular fibers projected to regions in the vestibular nuclei that overlapped with the horizontal semicircular canal terminal fields, whereas saccular afferents projected to regions that received vertical canal fiber terminations. Lagenar afferents projected throughout the cochlear nuclei, to the dorsolateral regions of the cerebellar nuclei, and to lateral regions of the superior, lateral, medial, and descending vestibular nuclei.

Dickman, J. D.; Fang, Q.

1996-01-01

45

What galvanic vestibular stimulation actually activates  

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

IanSCurthoys

2012-07-01

46

Vestibular humanoid postural control.  

Science.gov (United States)

Many of our motor activities require stabilization against external disturbances. This especially applies to biped stance since it is inherently unstable. Disturbance compensation is mainly reactive, depending on sensory inputs and real-time sensor fusion. In humans, the vestibular system plays a major role. When there is no visual space reference, vestibular-loss clearly impairs stance stability. Most humanoid robots do not use a vestibular system, but stabilize upright body posture by means of center of pressure (COP) control. We here suggest using in addition a vestibular sensor and present a biologically inspired vestibular sensor along with a human-inspired stance control mechanism. We proceed in two steps. First, in an introductory review part, we report on relevant human sensors and their role in stance control, focusing on own models of transmitter fusion in the vestibular sensor and sensor fusion in stance control. In a second, experimental part, the models are used to construct an artificial vestibular system and to embed it into the stance control of a humanoid. The robot's performance is investigated using tilts of the support surface. The results are compared to those of humans. Functional significance of the vestibular sensor is highlighted by comparing vestibular-able with vestibular-loss states in robot and humans. We show that a kinematic body-space sensory feedback (vestibular) is advantageous over a kinetic one (force cues) for dynamic body-space balancing. Our embodiment of human sensorimotor control principles into a robot is more than just bionics. It inspired our biological work (neurorobotics: 'learning by building', proof of principle, and more). We envisage a future clinical use in the form of hardware-in-the-loop simulations of neurological symptoms for improving diagnosis and therapy and designing medical assistive devices. PMID:19665555

Mergner, Thomas; Schweigart, Georg; Fennell, Luminous

2009-01-01

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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

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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

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Vestibular control of body orientation in lamprey  

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Maintenance of body orientation (postural control) is a vital motor function of the brain. The general goal of this project was to understand the organization and operation of neuronal networks responsible for postural control. The lamprey (a lower vertebrate) was used as a model animal. The postural control system in the lamprey, driven by vestibular input, maintains a definite orientation of the longitudinal body axis in relation to horizon (pitch angle) and the dorsal-sid...

Pavlova, Elena

2004-01-01

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Vestibular Schwannoma (Acoustic Neuroma) and Neurofibromatosis  

Science.gov (United States)

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

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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

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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

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Recovery from vestibular ototoxicity  

Science.gov (United States)

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

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

2001-01-01

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Vestibular activity and cognitive development in children: Perspectives  

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Full Text Available 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 relays signals from the vestibular nuclei to the hippocampus where this input is indispensable for neuronal responses selective for the position and orientation of the head in space. One aspect of hippocampal systems' processing to create episodic and contextual memories is its role in spatial orientation and navigation behaviors that require processing of relations between background cues. These are also impaired in adult patients with vestibular deficits, however little is known about the impact of vestibular loss on cognitive development in children. This is investigated here with a particular emphasis upon the hypothetical mechanisms and potential impact of vestibular loss at critical ages on the development of respective spatial and non-spatial cognitive processes and their brain substrates.

SidneyIWiener

2013-12-01

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Vestibular schwannoma mimicking horizontal cupulolithiasis.  

Science.gov (United States)

Positional vertigo and nystagmus can be due to canalithiasis, cupulolithiasis and less commonly, an underlying peripheral or central vestibular disorder. We present a patient with vestibular schwannoma who initially sought treatment for positioning vertigo. Video-oculography on the roll-test revealed direction-changing horizontal apogeotropic nystagmus, consistent with horizontal cupulolithiasis. However, further audio-vestibular investigations and imaging confirmed a right vestibulopathy attributable to a schwannoma of the right vestibular nerve. This case report suggests that vestibular schwannoma should be considered as another potential mimicker of horizontal cupulolithiasis. PMID:23665081

Taylor, Rachael L; Chen, Luke; Lechner, Corinna; Aw, Swee T; Welgampola, Miriam S

2013-08-01

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Vestibular migraine: Diagnosis and treatment  

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

Batuecas-Caletrio A

2013-03-01

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Enlarged Vestibular Aqueducts and Childhood Hearing Loss  

Science.gov (United States)

... known as a dilated vestibular aqueduct or a large vestibular aqueduct. If a vestibular aqueduct is enlarged, the endolymphatic duct and sac usually grow large too. The functions of the endolymphatic duct and ...

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

Scientific Electronic Library Online (English)

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

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Audiologic diagnostics of vestibular schwannoma  

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

Komazec Zoran

2004-01-01

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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

 
 
 
 
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Vestibular tributaries to the vein of the vestibular aqueduct.  

DEFF Research Database (Denmark)

CONCLUSION: The vein of the vestibular aqueduct drains blood from areas extensively lined by vestibular dark cells (VDCs). A possible involvement in the pathogenesis of an impaired endolymphatic homeostasis can be envisioned at the level of the dark cells area. OBJECTIVES: The aim of this study was to investigate the vascular relationship between the vein of the vestibular aqueduct and the vestibular apparatus, with focus on the VDCs. METHODS: Sixteen male Wistar rats were divided into groups of 6 and 10. In the first group, 2 µm thick sections including the vein of the vestibular aqueduct, utricle, and crista ampullaris of the lateral ampulla were examined by light microscopy and computer-generated three-dimensional imaging. In the second group, ultrathin sections including venules and VDCs were examined by transmission electron microscopy. RESULTS: A microvascular network was observed in close relation to the VDCs in the utricle and the crista ampullaris of the lateral semicircular canal in the vestibular apparatus. One major vein emanated from these networks, which emptied into the vein of the vestibular aqueduct. Veins draining the saccule and the common crus of the superior and posterior semicircular canals were likewise observed to merge with the vein of the vestibular aqueduct.

Hansen, Jesper Marsner; Qvortrup, Klaus

2010-01-01

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A Monosynaptic Pathway Links the Vestibular Nuclei and Masseter Muscle Motoneurons in Rats  

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Physiological evidence indicates that vestibular signals modulate the activity of motoneurons innervating the masseter muscle. Recently, experiments using transynaptic retrograde transport of pseudorabies virus provided anatomical evidence that many neurons concentrated in the dorsomedial part of the parvicellular division of the medial vestibular nucleus (MVePC) and the caudal prepositus hypoglossi (PH) provide inputs to motoneurons innervating the lower third of the superficial layer of the...

Cuccurazzu, B.; Deriu, F.; Tolu, E.; Yates, B. J.; Billig, I.

2007-01-01

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Vestibular damage in chronic ototoxicity: a mini-review.  

Science.gov (United States)

Ototoxicity is a major cause of the loss of hearing and balance in humans. Ototoxic compounds include pharmaceuticals such as aminoglycoside antibiotics, anti-malarial drugs, loop diuretics and chemotherapeutic platinum agents, and industrial chemicals including several solvents and nitriles. Human and rodent data indicate that the main target of toxicity is hair cells (HCs), which are the mechanosensory cells responsible for sensory transduction in both the auditory and the vestibular system. Nevertheless, the compounds may also affect the auditory and vestibular ganglion neurons. Exposure to ototoxic compounds has been found to cause HC apoptosis, HC necrosis, and damage to the afferent terminals, of differing severity depending on the ototoxicity model. One major pathway frequently involved in HC apoptosis is the c-jun N-terminal kinase (JNK) signaling pathway activated by reactive oxygen species, but other apoptotic pathways can also play a role in ototoxicity. Moreover, little is known about the effects of chronic low-dose exposure. In rodent vestibular epithelia, extrusion of live HCs from the sensory epithelium may be the predominant form of cell demise during chronic ototoxicity. In addition, greater involvement of the afferent terminals may occur, particularly the calyx units contacting type I vestibular HCs. As glutamate is the neurotransmitter in this synapse, excitotoxic phenomena may participate in afferent and ganglion neuron damage. Better knowledge of the events that take place in chronic ototoxicity is of great interest, as it will increase understanding of the sensory loss associated with chronic exposure and aging. PMID:24333467

Sedó-Cabezón, Lara; Boadas-Vaello, Pere; Soler-Martín, Carla; Llorens, Jordi

2014-07-01

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Enlarged Vestibular Aqueduct Syndrome (EVAS)  

Science.gov (United States)

... larger than normal, it is known as a large vestibular aqueduct (LVA) or by the term used here, enlarged ... thin-section fast spin-echo MR of the large vestibular aqueduct syndrome. Am J Neuroradiol. 1997;18:67–75. ...

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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

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Compensation Following Bilateral Vestibular Damage  

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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

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Atypical Manifestation of Vestibular Schwannoma  

Scientific Electronic Library Online (English)

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

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

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Audiometric and vestibular abnormalities in macular degeneration  

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Audiometric (pure tone audiometry and tone decay) and vestibular examinations (bilateral caloric test and electronystagmography) were carried out in 10 cases of macular degeneration of different types and 10 normal individuals as control. Out of 10 cases of macular degeneration of various types, 3 (30%) showed hearing impairment, while on vestibular examination 3 (30%) also had vestibular abnormalities. Only one case was associated with both audiometric as well as vestibular abn...

Singh R; Ops, Maurya; Yadav V; Samant H

1991-01-01

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Multimodal coding of three-dimensional rotation and translation in area MSTd: comparison of visual and vestibular selectivity.  

Science.gov (United States)

Recent studies have shown that most neurons in the dorsal medial superior temporal area (MSTd) signal the direction of self-translation (i.e., heading) in response to both optic flow and inertial motion. Much less is currently known about the response properties of MSTd neurons during self-rotation. We have characterized the three-dimensional tuning of MSTd neurons while monkeys passively fixated a central, head-fixed target. Rotational stimuli were either presented using a motion platform or simulated visually using optic flow. Nearly all MSTd cells were significantly tuned for the direction of rotation in the absence of optic flow, with more neurons preferring roll than pitch or yaw rotations. The preferred rotation axis in response to optic flow was generally the opposite of that during physical rotation. This result differs sharply from our findings for translational motion, where approximately half of MSTd neurons have congruent visual and vestibular preferences. By testing a subset of neurons with combined visual and vestibular stimulation, we also show that the contributions of visual and vestibular cues to MSTd responses depend on the relative reliabilities of the two stimulus modalities. Previous studies of MSTd responses to motion in darkness have assumed a vestibular origin for the activity observed. We have directly verified this assumption by recording from MSTd neurons after bilateral labyrinthectomy. Selectivity for physical rotation and translation stimuli was eliminated after labyrinthectomy, whereas selectivity to optic flow was unaffected. Overall, the lack of MSTd neurons with congruent rotation tuning for visual and vestibular stimuli suggests that MSTd does not integrate these signals to produce a robust perception of self-rotation. Vestibular rotation signals in MSTd may instead be used to compensate for the confounding effects of rotatory head movements on optic flow. PMID:17804635

Takahashi, Katsumasa; Gu, Yong; May, Paul J; Newlands, Shawn D; DeAngelis, Gregory C; Angelaki, Dora E

2007-09-01

70

Vestibular control of entorhinal cortex activity in spatial navigation  

Directory of Open Access Journals (Sweden)

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

71

Compensation following bilateral vestibular damage  

Directory of Open Access Journals (Sweden)

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

72

Aging of vestibular function evaluated using correlational vestibular autorotation test  

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

Hsieh LC

2014-09-01

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A role for BDNF in early postnatal rat vestibular epithelia maturation: implication of supporting cells.  

Science.gov (United States)

The early development of the inner ear is largely determined by two members of the neurotrophic family: brain-derived neurotrophic factor (BDNF) and neurotrophin 3 (NT-3). Little information is available on the role of these neurotrophins during the late stages of vestibular development in the rat which take place during the first postnatal weeks. At this period where terminal synaptogenesis and maturation occur, we have investigated the expression and the activity of BDNF, the most important neurotrophin in the vestibular system. Using different experimental approaches, we show that BDNF is released by vestibular epithelia on postnatal day 3 (P3) and continues to have a trophic effect on vestibular neurones in vitro. Immunocytochemistry coupled to confocal microscopy revealed a remarkable evolution in BDNF localization during later stages of development. Whereas BDNF is present in both supporting cells and hair cells at P3, its distribution gradually changed and is highly compartmentalized within the upper part of supporting cells at P8 and P15. In parallel, we observed the presence of a truncated form of the BDNF receptor in sensory hair cells. These results suggest an original role for supporting cells, which could be involved in the release of BDNF during the late stages of synaptogenesis in mammalian vestibular epithelia. In particular, BDNF could participate to the set up of the calyx, a specific nerve structure surrounding type I vestibular hair cells. PMID:9749722

Montcouquiol, M; Valat, J; Travo, C; Sans, A

1998-02-01

74

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

Science.gov (United States)

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

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

2002-01-01

75

Vestibular rehabilitation with electrotactile vestibular substitution: early effects.  

Science.gov (United States)

We aimed to determine the early efficacy of vestibular rehabilitation with electrotactile vestibular substitution system (EVSS) as a new treatment modality in patients with bilateral vestibular loss due to aminoglycoside-induced ototoxicity. Six men and four women with bilateral vestibular failure were rehabilitated with EVSS prospectively. Patients were trained with EVSS for ten sessions each lasted 20 min, two sessions per day. Sensory organization test (SOT) protocol and dizziness handicap inventory (DHI) were used to compare pre- and post-training results of the rehabilitative treatment. Post-training tests were done at the first day of post-treatment period. All ten patients in the standardized testing subset demonstrated improved scores in the composite SOT scores and in the functional transfer testing with DHI after 5 days of training with the EVSS. In conclusion, these preliminary results demonstrate efficacy of the EVSS in improving patients symptoms and signs and signify the evidence of sensory substitution in the early post-training period. PMID:19082618

Uneri, Alev; Polat, Senol

2009-08-01

76

The vestibular implant: Quo vadis?  

Directory of Open Access Journals (Sweden)

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

77

[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

78

DARA vestibular equipment onboard MIR.  

Science.gov (United States)

In space, the weightless environment provides a different stimulus to the otolith organs of the vestibular system, and the resulting signals no longer correspond with the visual and other sensory signals sent to the brain. This signal conflict causes disorientation. To study this and also to understand the vestibular adaptation to weightlessness, DARA has developed scientific equipment for vestibular and visuo-oculomotoric investigations. Especially, two video-oculography systems (monocular--VOG--and binocular--BIVOG, respectively) as well as stimuli such as an optokinetic stimulation device have successfully been employed onboard MIR in the frame of national and European missions since 1992. The monocular VOG was used by Klaus Flade during the MIR '92 mission, by Victor Polyakov during his record 15 months stay onboard MIR in 1993/94 as well as by Ulf Merbold during EUROMIR '94. The binocular version was used by Thomas Reiter and Sergej Avdeyev during the 6 months EUROMIR '95 mission. PIs of the various experiments include H. Scherer and A. Clarke (FU Berlin), M. Dieterichs and S. Krafczyk (LMU Munchen) from Germany as well as C.H. Markham and S.G. Diamond from the United States. Video-Oculography (VOG) is a technique for examining the function of the human balance system located in the inner ear (vestibular system) and the visio-oculomotor interactions of the vestibular organ. The human eye movements are measured, recorded and evaluated by state-of-the-art video techniques. The method was first conceived and designed at the Vestibular Research Laboratory of the ENT Clinic in Steglitz, FU Berlin (A. Clarke, H. Scherer). Kayser-Threde developed, manufactured and tested the facilities for space application under contract to DARA. Evaluation software was first provided by the ENT Clinic, Berlin, later by our subcontractor Sensomotoric Instruments (SMI), Teltow. Optokinetic hardware to support visuo-oculomotoric investigations, has been shipped to MIR for EUROMIR '95 and has successfully been used in conjunction with VOG by ESA astronaut Thomas Reiter. Most recently, BIVOG aboard MIR will be reused in the frame of German/Russian joint experiment sessions employing two Russian cosmonauts from August 1997 to January 1998. PMID:11541933

Hofmann, P; Kellig, A; Hoffmann, H U; Ruyters, G

1998-01-01

79

Current treatment options in vestibular migraine.  

Science.gov (United States)

Approximately 1% of the general population in western industrialized countries suffers from vestibular migraine. However, it remains widely unknown and often under diagnosed despite the recently published diagnostic criteria for vestibular migraine. Treatment trials that specialize on vestibular migraine are scarce and systematic randomized controlled clinical trials are now only emerging. This review summarizes the knowledge on the currently available treatment options that were tested specifically for vestibular migraine and gives an evidence-based, informed treatment recommendation with all its limitations. To date only two randomized controlled treatment trials provide limited evidence for the use of rizatriptan and zolmitriptan for the treatment of vestibular migraine attacks because of methodological shortcomings. There is an ongoing multicenter randomized placebo-controlled trial testing metoprolol 95?mg vs. placebo (PROVEMIG-trial). Therefore, the therapeutic recommendations for the prophylactic treatment of vestibular migraine are currently widely based on the guidelines of migraine with and without aura as well as expert opinion. PMID:25538676

Obermann, Mark; Strupp, Michael

2014-01-01

80

Personality Changes in Patients with Vestibular Dysfunction  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

 
 
 
 
81

Visual mental imagery during caloric vestibular stimulation  

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We investigated high-resolution mental imagery and mental rotation, while the participants received caloric vestibular stimulation. High-resolution visual mental imagery tasks have been shown to activate early visual cortex, which is deactivated by vestibular input. Thus, we predicted that vestibular stimulation would disrupt high-resolution mental imagery; this prediction was confirmed. In addition, mental rotation tasks have been shown to activate posterior parietal cortex, which is also en...

Mast, Fred W.; Merfeld, Daniel M.; Kosslyn, Stephen M.

2006-01-01

82

Vestibular evaluation in Behçet's disease. Personal experience.  

Science.gov (United States)

Few reports have appeared in the literature concerning vestibular findings in Behçet's disease. In the present study, extensive vestibular testing, performed in 14 patients (8 male, 6 female; mean age: 32 years; range: 12-51) presenting definite Behçet's disease, revealed a high prevalence of central vestibular dysfunctions (78%). Data reported here suggest that an otoneurological evaluation of Behçet's disease patients may be helpful in identifying unexpected vestibular dysfunctions and central nervous system involvement different from the classical manifestations of the neuro-Behçet's syndrome. PMID:15871606

Cadoni, G; Agostino, S; Manganelli, C; Scipione, S; Turco, S; Focosi, F; Ottaviani, F

2004-10-01

83

Personality Changes in Patients with Vestibular Dysfunction  

Directory of Open Access Journals (Sweden)

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

PaulSmith

2013-10-01

84

Finding physiological responses in vestibular evoked potentials.  

Science.gov (United States)

Vestibular prostheses are regarded as a promising tool to restore lost sensation in patients with vestibular disorders. These prostheses often electrically stimulate the vestibular nerve and stimulation efficacy is evaluated by measuring the vestibulo-ocular reflex (VOR). However, eye movement recording as intuitive metric of vestibular functionality is difficult to obtain outside the laboratory environment, and hence not available as an error signal in a closed-loop prosthesis. Recently we investigated vestibular evoked potentials (VEPs) by stimulating and recording in the same semicircular canal of a guinea pig. Here we studied the correlation between VOR and one region of VEP. We further analyzed a second portion of VEP, where vestibular nerve activity should occur using rectified bin integration (RBI). To this end, stimulation artifact was significantly reduced by hardware and software approaches. We found a high VEP-VOR correlation (R-squared=0.86), suggesting that VEP could substitute VOR as metric of vestibular function. Differences between below and above vestibular threshold stimulation were seen for the second portion of VEP. Further investigations are required to determine the specific parts of VEP that accurately represents vestibular function(s). PMID:22254790

Nguyen, T A K; Kogler, V; DiGiovanna, J; Micera, S

2011-01-01

85

Vestibular Schwannoma or acoustic neuroma  

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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 paral...

Hekmatara M

1997-01-01

86

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

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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 expe...

Zucca Gianpiero; Zampini Valeria; Botta Laura; Tritto Simona; Valli Paolo; Masetto Sergio

2009-01-01

87

[Vestibular disorders in old age].  

Science.gov (United States)

The elderly show a general reduction of their bodily and mental reactions. They become slower to react and their sensory ability decreases, e.g. hearing, vision, smell and taste. With increasing age, disturbances of the balance system are found more frequently, resulting in dysequilibrium, vertigo, lightheadedness and falling. We investigated the physiological changes in the vestibular system associated with the ageing processes. We selected 470 patients aged from 1-90 years from 1500 routine neurological patients. All of these patients underwent a routine neuro-otological test battery including vestibular-spinal, caloric, rotatory and optokinetic tests with electronystagmographic recording. Vestibular ocular reactions change markedly over nine decades. The nystagmus reactions, expressed by frequency, amplitude and maximal slow phase velocity of children differ from those of adults and even more from those of the elderly. The quantitative nystagmus dynamics after caloric and rotatory stimulation are accompanied by qualitative changes of the nystagmus signal. With increasing age destructive signs appear which may produce unreadable electronystagmograms. The standing and moving pattern of the elderly patient is characterized by instability, slowness, tremor and ataxia. The results of the Romberg test show an increase of instability and unsteadiness in older patients. The Unterberger test, recorded by craniocorpography, demonstrates an increase of atactic patterns with increasing age. These changes are the result of age-related physiological changes in the sensory, cerebral, peripheral nervous and muscular systems. PMID:1794960

Aust, G

1991-12-01

88

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

Science.gov (United States)

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

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

2002-01-01

89

Epidemiology and natural history of vestibular schwannomas  

DEFF Research Database (Denmark)

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

Stangerup, Sven-Eric; Caye-Thomasen, Per

2012-01-01

90

Vestibular and oculomotor physiology; Proceedings of the International Meeting, New York, NY, September 22-25, 1980  

Science.gov (United States)

Papers are presented showing recent progress in the understanding of the processing of visual and vestibular signals by the central nervous system to produce eye movements and postural responses. Specific topics include the directional sensitivity of hair cells to hair bundle deflection, the effects of gravity on rotatory nystagmus, the reticulovestibular organization associated with horizontal fast eye movement, the pathways controlling the extraocular eye muscles, the organization of visual-vestibular interaction in vestibular neurons, motion sickness due to vision reversal in stroboscopic light, and vestibular habituation during sinusoidal rotation. Attention is also given to vestibulo-ocular, vestibulocollic and cervicocollic reflexes, visual mossy fiber inputs to the flocculus, directional plasticity of the vestibulo-ocular reflex, the relation of active head rotation with eye-head coordination, instability in the optokinetic-vestibular system as an explanation for periodic alternating nystagmus, the effects of visual and nonvisual fixation on vestibular nystagmus, interaction of saccades with the vestibulo-ocular reflex, and the role of the plantar mechanoreceptor in equilibrium control.

Cohen, B.

1981-01-01

91

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

92

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

Directory of Open Access Journals (Sweden)

Full Text Available OBJETIVO: verificar os achados vestibulares em pacientes com perda auditiva neurossenssorial usuários de aparelho de amplificação sonora individual. MÉTODOS: vinte pacientes, 11 do sexo feminino e nove do sexo masculino, com idades entre 39 e 85 anos, com perda auditiva neurossenssorial bilateral de grau moderado e severo foram atendidos em uma Instituição de Ensino Superior e submetidos a uma anamnese, inspeção otológica, avaliação audiológica, imitanciometria e ao exame vestibular por meio da vectoeletronistagmografia. RESULTADOS: a dos 20 pacientes avaliados, 18 (90% apresentaram queixa de zumbido, 15 (75% queixa de tontura e oito (40% queixa de cefaléia; b houve predomínio de alteração na prova calórica e no sistema vestibular periférico; c o resultado do exame vestibular esteve alterado em 14 pacientes (70%, sendo, oito casos (40% de síndrome vestibular periférica irritativa e seis casos (30% de síndrome vestibular periférica deficitária; d verificou-se diferença significativa entre o resultado do exame vestibular e o tempo de uso do aparelho de amplificação sonora individual; e dos cinco pacientes que não referiram nenhum sintoma vestibular, quatro (80% apresentaram alteração no exame. CONCLUSÃO: ressalta-se a sensibilidade e importância do estudo funcional do sistema do equilíbrio neste tipo de população, uma vez que podem ocorrer alterações na avaliação labiríntica independente da presença de sintomas.PURPOSE: to check vestibular findings in patients with sensoneural hearing loss, hearing aid users. METHODS: 20 patients (eleven females and nine males aging from 39 to 85-year-old with bilateral sensorineural hearing loss, from moderate to severe degrees, were attended in a higher education institution evaluated by medical history, otological inspections, complete basic conventional audiological evaluations, acoustic impedance tests and vectoeletronystagmography. RESULTS: a from the 20 evaluated patients, 18 (90% showed tinnitus complaint, 15 (75% dizziness complaint and eight (40% headache complaint; b There was a prevalence of alterations in the caloric test and in the peripheral vestibular system; c the results of the vestibular exam showed alterations in 14 patients (70% being, eight cases (40% of peripheral vestibular irritative syndromes and six cases (30% of peripheral vestibular deficiency syndromes; d we verified significant difference between the vestibular exam results and how long the patient had use the hearing aid; e from the five patients that did not related vestibular symptoms four (80% showed alterations in the vestibular exam. CONCLUSION: the importance and sensibility of the functional study regarding the balance system in this type of population must be emphasized because same disorders may occur in the vestibular exam in spite of symptom presence.

Fabiane Paulin

2009-01-01

93

Vestibular perceptual thresholds to angular rotation in acute unilateral vestibular paresis and with galvanic stimulation.  

Science.gov (United States)

Studies of compensation of injury to the human vestibular system have, in the main, focused on the vestibular-ocular reflex. Probing vestibular perception allows more of the sensory pathway to be assessed. We present a novel paradigm for simultaneously testing vestibular perceptual and nystagmic thresholds to angular acceleration around an earth vertical axis. The perceptual thresholds can be modulated asymmetrically in normal subjects by DC galvanic stimulation with the head flexed in the roll plane, as expected from the main torsional plane of action of the galvanic stimulus. The perceptual and nystagmic thresholds were bilaterally elevated in acute vestibular neuritis, a unilateral condition, possibly due to central suppression of vestibular input. The degree of asymmetry in thresholds was small in comparison with the large caloric asymmetry present in the patients, indicating a relatively preserved capacity for near-threshold performance of the non-damaged labyrinth both in the "on" and "off" directions. PMID:21951002

Cutfield, Nicholas J; Cousins, Sian; Seemungal, Barry M; Gresty, Michael A; Bronstein, Adolfo M

2011-09-01

94

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

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Introducción: En el examen vestibular de un paciente vertiginoso juegan un rol muy importante las pruebas calóricas, pero la realización de éstas, unida a las nuevas pruebas que ha traído el avance tecnológico y computacional de la medicina, ha significado que el examen vestibular se ha convertido en la práctica diaria en un estudio muy largo y oneroso, por tal motivo parece útil la realización de un examen vestibular abreviado preliminar hecho en la misma consulta del médico que pe...

Alejandro Peña M

2011-01-01

95

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

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The vestibular evoked myogenic potential (VEMP) test is a relatively new diagnostic tool that is in the process of being investigated in patients with specific vestibular disorders. Briefly, the VEMP is a biphasic response elicited by loud clicks or tone bursts recorded from the tonically contracted sternocleidomastoid muscle, being the only resource available to assess the function of the saccule and the lower portion of the vestibular nerve. AIM: In this review, we shall highlight the histo...

Renato Cal; Fayez Bahmad Jr

2009-01-01

96

[Should vestibular neuritis be treated with corticosteroids?].  

Science.gov (United States)

Recent studies have shown that corticosteroid treatment of patients with vestibular neuritis significantly improves recovery of peripheral vestibular function. At follow-up, the number of patients with a normal caloric response was larger among those treated with corticosteroids. However, improvement of caloric responses may not correlate directly with patient symptoms and up to now improved vertigo/dizziness due to corticosteroid treatment has not been reported. Consequently, although corticosteroid may be a treatment option, it should currently only be considered in those vestibular neuritis patients who are willing to take part in a structured follow-up with both caloric testing and evaluation of subjective symptoms. PMID:18846122

Brantberg, Krister; Goplen, Frederik; Bråthen, Geir; Nordahl, Stein Helge Glad; Arnesen, Haakon

2008-09-25

97

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

Directory of Open Access Journals (Sweden)

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

JudithWagner

2011-08-01

98

Multi-modal coding of three-dimensional rotation and translation in area MSTd: Comparison of visual and vestibular selectivity  

Science.gov (United States)

Recent studies have shown that most neurons in the dorsal medial superior temporal area (MSTd) signal the direction of self-translation (i.e., heading) in response to both optic flow and inertial motion. Much less is currently known about the response properties of MSTd neurons during self-rotation. We have characterized the three-dimensional tuning of MSTd neurons while monkeys passively fixated a central, head-fixed target. Rotational stimuli were either presented using a motion platform or simulated visually using optic flow. Nearly all MSTd cells were significantly tuned for the direction of rotation in the absence of optic flow, with more neurons preferring roll than pitch or yaw rotations. The preferred rotation axis in response to optic flow was generally opposite to that during physical rotation. This result differs sharply from our findings for translational motion, where roughly half of MSTd neurons have congruent visual and vestibular preferences. Previous studies of MSTd responses to motion in darkness have assumed a vestibular origin for the activity observed. We have directly verified this assumption by recording from MSTd neurons after bilateral labyrinthectomy. Selectivity for physical rotation and translation stimuli was eliminated after labyrinthectomy, whereas selectivity to optic flow was unaffected. Overall, the lack of MSTd neurons with congruent rotation tuning for visual and vestibular stimuli suggests that MSTd does not integrate these signals to produce a robust percept of self-rotation. Vestibular rotation signals in MSTd may instead be used to compensate for the confounding effects of rotatory head movements on optic flow. PMID:17804635

Takahashi, Katsumasa; Gu, Yong; May, Paul J.; Newlands, Shawn D.; DeAngelis, Gregory C.; Angelaki, Dora E.

2008-01-01

99

Pontocerebellar atrophy combined with vestibular-reticular degeneration.  

Science.gov (United States)

A 41-year-old woman was hospitalized in 1939 with neurologic signs from which there was complete recovery over a two-year period. In 1965 she was readmitted because of increasing forgetfulness and inability to care for herself; there were no neurologic deficits. In June 1970 torticollis developed and persisted until her death 15 months later. No cerebellar signs were elicited, but increased muscle tone was prominent. The brain showed remarkable flattening of the inferior surface of the cerebellum; the pons was small. The medullary substance of the cerebellum and each branchium pontis appeared completely demyelinated. Transverse fibres were apparently absent in the central basis pontis. Microscopically in addition to the pontocerebellar atrophy there was degeneration of the vestibular system, reticular formation of the medulla oblongata and medial longitudinal fasciculi. The inferior olives showed only moderate neuronal degeneration in the caudal areas. Basal ganglia and thalamus showed some involvement in the pathological process. It is postulated that the vestibular-reticular system atrophy was the anatomic substrate for the torticollis, and apparently overshadowed cerebellar signs, which are ordinarily associated with pontocerebellar atrophy. PMID:300099

Neumann, M A

1977-01-01

100

Calcified vestibular schwannoma in the cerebellopontine angle.  

Science.gov (United States)

Although vestibular schwannoma is a common tumor in the cerebellopontine angle, calcified vestibular schwannoma is rare. A 59-year-old woman with sudden onset epileptic seizures, was referred to Hokkaido Neurosurgical Memorial Hospital. Neurological examination revealed left Bruns nystagmus, left deafness and left cerebellar ataxia. Brain MRI revealed a mass, about 3cm in diameter, in the left cerebellopontine angle. The mass showed heterogeneous intensity on T1- and T2-weighted and fluid-attenuated inversion recovery (FLAIR) images. Hydrocephalus was seen. On CT scan, the tumor was calcified. Preoperatively, vestibular schwannoma, meningioma, cavernous hemangioma, or thrombosed giant aneurysm were considered as differential diagnoses. The pathological diagnosis was schwannoma. For a calcified mass in the cerebellopontine angle, vestibular schwannoma should be considered in the differential diagnosis to plan appropriate treatment strategies. PMID:17884507

Katoh, Masahito; Aida, Toshimitsu; Imamura, Hiroyuki; Aoki, Takeshi; Yoshino, Masami; Kashiwazaki, Daina; Takei, Hidetoshi

2007-12-01

 
 
 
 
101

Vestibular effects on cerebral blood flow  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ot...

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

2009-01-01

102

Perspectives in vestibular diagnostics and therapy  

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[english] Vestibular diagnostics and therapy ist the mirror of technological, scientific and socio-economics trends as are other fields of clinical medicine. These trends have led to a substantial diversification of the field of neurotology.The improvements in diagnostics have been characterized by the introduction of new receptor testing tools (e.g., VEMPs), progress in imaging (e.g., the endolymphatic hydrops) and in the description of central-vestibular neuroplasticity. The etiopathology o...

Ernst, Arneborg

2012-01-01

103

Vestibular and Saccadic Abnormalities in Gaucher's Disease.  

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Gaucher's disease (GD) is a hereditary lysosomal storage disease characterized by abnormal deposition of glucocerebroside due to the enzyme glucocerebrosidase deficiency, resulting in multi-organ pathology. GD type III has a progressive neurological involvement. We studied the vestibular and saccadic abnormalities in GD type III to determine if these parameters may be useful for assessing neurological involvement. We evaluated the vestibular and saccadic responses of two siblings with genetically identified GD type III on enzyme replacement therapy. Vestibular functions were assessed with the head impulse test (HIT), vestibular evoked myogenic potentials (VEMPs), and electrical vestibular stimulation (EVS). Saccadic functions were investigated with volitional horizontal and vertical saccades to ±20°. Three-dimensional head and eye movements were recorded with dual-search coils and VEMP with surface electrodes. HIT showed impaired individual semicircular canal function with halved angular vestibulo-ocular reflex (VOR) gains and absent horizontal refixation saccade. Ocular and cervical VEMPs to air-conducted clicks were absent in the older sibling, and only cervical VEMP was present in the younger sibling indicating otolithic dysfunction. EVS showed prolonged onset latency and attenuated tonic and phasic responses suggesting impaired neural conduction and vestibular function. Horizontal saccadic velocity was miniscule (<30°/s) and multiple back-to-back saccades with saccade-vergence interaction were utilized to minimize eye position error in the older sibling. Vertical saccades were slightly abnormal, but vergence and smooth pursuit were normal in both siblings. Our findings suggest that GD affected the vestibular nuclei in addition to the paramedian pontine reticular formation. These vestibular and saccadic abnormalities may be useful biomarkers to monitor neurological deterioration. PMID:24142279

Chen, Luke; Halmagyi, G Michael; Todd, Michael J; Aw, Swee T

2014-01-01

104

Vestibular disorders in migrainous children and adolescents  

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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

105

Vestibular function in severe bilateral vestibulopathy  

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OBJECTIVES—To assess residual vestibular function in patients with severe bilateral vestibulopathy comparing low frequency sinusoidal rotation with the novel technique of random, high acceleration rotation of the whole body.?METHODS—Eye movements were recorded by electro-oculography in darkness during passive, whole body sinusoidal yaw rotations at frequencies between 0.05 and 1.6 Hz in four patients who had absent caloric vestibular responses. These were compared w...

Wiest, G.; Demer, J.; Tian, J.; Crane, B.; Baloh, R.

2001-01-01

106

Vestibular Evoked Myogenic Potentials in Migraine Patients  

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Full Text Available Background and Aim: Patients with migraine commonly show vestibular symptoms. However, abnormal neurotological test findings during the inter-attack intervals, even in the absence of vestibular symptoms, are suggestive of subclinical vestibular dysfunction in migraine. This study aimed to compare the vestibular evoked myogenic potentials between migraine patients and normal individuals.Methods: Subjects included 25 patients with migraine and 26 healthy volunteers with an age range of 20-53 years old. The vestibular evoked myogenic potentials were recorded with 500 Hz tone bursts at 95 dB nHL.Results: Mean of absolute amplitude and p13 latency values in the migraine group were significantly less and more than the normal group, respectively (p=0.001 for absolute amplitude in right and left ears; p=0.004 for p13 latency in right ears and p=0.02 in left ears. There was no statistically significant difference between the two groups in mean of the n23 latency and also the amplitude ratio (p>0.05.Conclusion: According to the prolonged latency of vestibular evoked myogenic potentials response, vestibulospinal tract in brainstem is probably involved in migraine patients. However, due to small sample size, for generalizing this result to all patients with migraine, further researches are needed.

Shohre Jalaie

2011-06-01

107

RECORDING OF VESTIBULAR EVOKED MYOGENIC POTENTIALS  

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

A. A. Sazgar

2006-05-01

108

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

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

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

2007-12-01

109

Schwannoma vestibular: involução tumoral espontânea Vestibular Schwannoma: spontaneous tumor involution  

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

Norma de Oliveira Penido

2007-12-01

110

Pharmacotherapy of vestibular disorders and nystagmus.  

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Vertigo and dizziness are with a life-time prevalence of ~30% among the most common symptoms and are often associated with nystagmus or other oculomotor disorders. The prerequisite for a successful treatment is a precise diagnosis of the underlying disorder. In this overview, the current pharmacological treatment options for peripheral and central vestibular, cerebellar, and oculomotor disorders including nystagmus are described. There are basically seven groups of drugs that can be used (the "7 As"): antiemetics; anti-inflammatory, anti-Menière's, and antimigraine medications; antidepressants, anticonvulsants, and aminopyridines. In acute vestibular neuritis, recovery of the peripheral vestibular function can be improved by treatment with oral corticosteroids. In Menière's disease, a long-term high-dose treatment with betahistine-dihydrochloride (at least 48 mg three times daily) had a significant effect on the frequency of the attacks; the underlying mode of action is evidently an increase in inner-ear blood flow. The use of aminopyridines is a well-established therapeutic principle in the treatment of downbeat and upbeat nystagmus as well as episodic ataxia type 2 and cerebellar gait disorders. As was shown in animal experiments, these potassium channel blockers increase the activity and excitability and normalize irregular firing of cerebellar Purkinje cells. They evidently augment the inhibitory influence of these cells on vestibular and deep cerebellar nuclei. A few studies showed that baclofen improves periodic alternating nystagmus; gabapentin and memantine improve pendular and infantile nystagmus. However, many other eye-movement disorders such as ocular flutter, opsoclonus, central positioning, and see-saw nystagmus are still difficult to treat. Although substantial progress has been made, further state-of-the-art trials must still be performed on many vestibular and oculomotor disorders, namely Menière's disease, vestibular paroxysmia, vestibular migraine, and many forms of central eye-movement disorders. PMID:24057832

Strupp, Michael; Kremmyda, Olympia; Brandt, Thomas

2013-07-01

111

Tests of walking balance for screening vestibular disorders  

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Few reliable tests are available for screening people rapidly for vestibular disorders although such tests would be useful for a variety of testing situations. Balance testing is widely performed but of unknown value for screening. The goal of this study was to determine the value of tests of walking balance for screening people with vestibular impairments. We tested three groups of patients with known vestibular impairments: benign paroxysmal positional vertigo, unilateral vestibular weaknes...

Cohen, Helen S.; Mulavara, Ajitkumar P.; Peters, Brian T.; Sangi-haghpeykar, Haleh; Bloomberg, Jacob J.

2012-01-01

112

The thalamocortical vestibular system in animals and humans  

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The vestibular system provides the brain with sensory signals about three-dimensional head rotations and translations. These signals are important for postural and oculomotor control, as well as for spatial and bodily perception and cognition, and they are subtended by pathways running from the vestibular nuclei to the thalamus, cerebellum and the "vestibular cortex." The present review summarizes current knowledge on the anatomy of the thalamocortical vestibular system and discusses data fro...

Lopez, Christophe; Blanke, Olaf

2011-01-01

113

Differential effect of dopa and subthalamic stimulation on vestibular activity in Parkinson's disease.  

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Postural disturbances in advanced Parkinson's disease are less responsive to therapy than other cardinal motor signs. The vestibulocollic reflex represents one brain-stem neuronal circuit involved in postural adjustments. The objective of this study was to investigate the vestibulocollic reflex in parkinsonian patients and the effects of subthalamic stimulation and dopa by recording vestibular-evoked myogenic potentials. After overnight withdrawal of medication, 20 patients with Parkinson's disease with (6 men, 4 women; mean age, 64.4 ± 2.2 years) or without (8 men, 2 women; mean age, 62.7 ± 3.9 years) implanted subthalamic electrodes in different treatment conditions were compared with 10 age-matched controls (5 men, 5 women; mean age, 59.6 ± 2.4 years). Vestibular-evoked myogenic potentials were recorded by electromyographic surface electrodes applied to both sternocleidomastoid muscles (band-pass filter, 8-1600 Hz; sampling rate, 5 kHz) and averaged in response to bilateral auditory tone bursts (120 dB SPL; sine waves, 7 ms; 1000 Hz) applied through earphones. Adjusted vestibular-evoked myogenic potential amplitudes were significantly smaller in parkinsonian patients than in controls, in particular in patients without surgery. Administration of dopa, but not subthalamic stimulation, significantly increased amplitudes. Onset latencies were similar for all groups and treatment conditions. Decreased vestibular-evoked myogenic potential amplitudes in parkinsonian patients suggest reduced vestibular nuclei excitability within the brain stem, which is modulated by dopa but not by subthalamic stimulation. This suggests different pathways for the action of both treatment modalities in Parkinson's disease and may explain clinical differences in terms of postural disturbances. © 2012 Movement Disorder Society. PMID:22693156

Pötter-Nerger, Monika; Reich, Martin M; Colebatch, James G; Deuschl, G; Volkmann, Jens

2012-09-01

114

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

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Full Text Available SciELO Brazil | Language: 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

115

[The research progress of large vestibular aqueduct syndrome].  

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Large vestibular aqueduct syndrome (LVAS) is one of common non-syndromic hearing disorders. With the rapid development of medical imaging, audiology, molecular biology, genetics, cochlear implant surgery, we have made remarkable achievements in the diagnosis and treatment of large vestibular aqueduct syndrome. This article reviewed related researches of the large vestibular aqueduct syndrome. PMID:23379123

Abulikemu, Yiming; Tang, Liang; Zhang, Jin

2012-11-01

116

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

117

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

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Full Text Available SciELO Brazil | Language: English 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

118

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

119

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

120

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

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

 
 
 
 
121

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

122

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 SciELO Brazil | Language: English Abstract in portuguese 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

123

Vestibular schwannoma: anatomical, medical and surgical perspective  

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

Ashfaq Ul Hassan

2013-06-01

124

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

125

Current treatment of vestibular, ocular motor disorders and nystagmus.  

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Vertigo and dizziness are among the most common complaints with a lifetime prevalence of about 30%. The various forms of vestibular disorders can be treated with pharmacological therapy, physical therapy, psychotherapeutic measures or, rarely, surgery. In this review, the current pharmacological treatment options for peripheral and central vestibular, cerebellar and ocular motor disorders will be described. They are as follows for peripheral vestibular disorders. In vestibular neuritis recovery of the peripheral vestibular function can be improved by treatment with oral corticosteroids. In Menière's disease a recent study showed long-term high-dose treatment with betahistine has a significant effect on the frequency of the attacks. The use of aminopyridines introduced a new therapeutic principle in the treatment of downbeat and upbeat nystagmus and episodic ataxia type 2 (EA 2). These potassium channel blockers presumably increase the activity and excitability of cerebellar Purkinje cells, thereby augmenting the inhibitory influence of these cells on vestibular and cerebellar nuclei. A few studies showed that baclofen improves periodic alternating nystagmus, and gabapentin and memantine, pendular nystagmus. However, many other eye movement disorders such as ocular flutter opsoclonus, central positioning, or see-saw nystagmus are still difficult to treat. Although progress has been made in the treatment of vestibular neuritis, downbeat and upbeat nystagmus, as well as EA 2, state-of-the-art trials must still be performed on many vestibular and ocular motor disorders, namely Menière's disease, bilateral vestibular failure, vestibular paroxysmia, vestibular migraine, and many forms of central eye movement disorders. PMID:21179531

Strupp, Michael; Brandt, Thomas

2009-07-01

126

Inferior vestibular neuritis: 3 cases with clinical features of acute vestibular neuritis, normal calorics but indications of saccular failure  

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Full Text Available Abstract Background Vestibular neuritis (VN is commonly diagnosed by demonstration of unilateral vestibular failure, as unilateral loss of caloric response. As this test reflects the function of the superior part of the vestibular nerve only, cases of pure inferior nerve neuritis will be lost. Case presentations We describe three patients with symptoms suggestive of VN, but normal calorics. All 3 had unilateral loss of vestibular evoked myogenic potential. A slight, asymptomatic position dependent nystagmus, with the pathological ear down, was observed. Conclusion We believe that these patients suffer from pure inferior nerve vestibular neuritis.

Økstad Siri

2006-12-01

127

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

128

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

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

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

129

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

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

Renato, Cal; Fayez, Bahmad Jr.

2009-06-01

130

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

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

Renato Cal

2009-06-01

131

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

132

Vestibular evoked myogenic potentials in Bell's palsy.  

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The aim of the present study was to evaluate vestibular nerve involvement in patients with Bell's palsy with ocular and cervical vestibular evoked myogenic potentials (oVEMP and cVEMP). Ten patients who were diagnosed with Bell's palsy and ten healthy controls were included. All patients underwent VEMP recordings within 6 days after their initial presentation. Patients with Bell's palsy had greater oVEMP asymmetry ratio comparing to healthy controls (-38.4 ± 28.7 % vs -1.3 ± 19.3 %, p = 0.005). As well N10 latencies of the oVEMP response were prolonged comparing to healthy controls (11.575 vs 9.72 ms). There was no difference in cVEMP asymmetry ratio or latencies between groups. We found no correlation between House-Brackmann grading scale and oVEMP asymmetry ratio (r = 0.003, p = 0.994). There are three possible explanations for increased oVEMP amplitudes on the affected side: (1) oVEMP response on the ipsilateral eye could be contaminated by facial nerve activity (blink reflex); (2) the amplitude of N10-P33 could be affected through the stapedial reflex; and (3) increased oVEMP amplitude could be the consequence of the vestibular nerve dysfunction itself, with prolonged latencies of the N10 oVEMP further supporting this explanation. The results of this study indicate possible involvement of the superior branch of the vestibular nerve in patients with Bell's palsy. PMID:24916836

Krbot Skoric, Magdalena; Adamec, Ivan; Habek, Mario

2014-10-01

133

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

134

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

135

Interaural difference values of vestibular evoked myogenic.  

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Migraine is a neurologic disease, which often is associated with a unilateral headache. Vestibular abnormalities are common in migraine. Vestibular evoked myogenic potentials (VEMPs) assess otolith function in particular functional integrity of the saccule and the inferior vestibular nerve. We used VEMP to evaluate if the migraine headache can affect VEMP asymmetry parameters. A total of 25 patients with migraine (22 females and 3 males) who were diagnosed according to the criteria of IHS-1988 were enrolled in this cross-sectional study. Control group consisted of 26 healthy participants (18 female and 8 male), without neurotological symptoms and history of migraine. The short tone burst (95 dB nHL, 500 Hz) was presented to ears. VEMP was recorded with surface electromyography over the contracted ipsilateral sternocleidomastoid (SCM) muscle. Although current results showed that the amplitude ratio is greater in migraine patients than normal group, there was no statistical difference between two groups in mean asymmetry parameters of VEMP. Asymmetry measurements in vestibular evoked myogenic potentials probably are not indicators of unilateral deficient in saccular pathways of migraine patients. PMID:25597603

Moallemi, Marziyeh; Hajiabolhassan, Fahimeh; Fatahi, Jamileh; Abolfazli, Roya; Jalaei, Shohre; Khamseh, Fatemeh

2015-01-01

136

Vestibular stimulation leads to distinct hemodynamic patterning  

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Previous studies demonstrated that responses of a particular sympathetic nerve to vestibular stimulation depend on the type of tissue the nerve innervates as well as its anatomic location. In the present study, we sought to determine whether such precise patterning of vestibulosympathetic reflexes could lead to specific hemodynamic alterations in response to vestibular afferent activation. We simultaneously measured changes in systemic blood pressure and blood flow (with the use of Doppler flowmetry) to the hindlimb (femoral artery), forelimb (brachial artery), and kidney (renal artery) in chloralose-urethane-anesthetized, baroreceptor-denervated cats. Electrical vestibular stimulation led to depressor responses, 8 +/- 2 mmHg (mean +/- SE) in magnitude, that were accompanied by decreases in femoral vasoconstriction (23 +/- 4% decrease in vascular resistance or 36 +/- 7% increase in vascular conductance) and increases in brachial vascular tone (resistance increase of 10 +/- 6% and conductance decrease of 11 +/- 4%). Relatively small changes (electrical stimulation of muscle and cutaneous afferents produced pressor responses (20 +/- 6 mmHg) that were accompanied by vasoconstriction in all three beds. These data suggest that vestibular inputs lead to a complex pattern of cardiovascular changes that is distinct from that which occurs in response to activation of other types of somatic afferents.

Kerman, I. A.; Emanuel, B. A.; Yates, B. J.

2000-01-01

137

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 | Language: English 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

138

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

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

139

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

140

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

 
 
 
 
141

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 SciELO Chile | Language: Spanish Abstract in spanish 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 hyperventi

Alejandro, Peña M.

2012-04-01

142

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

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

Alejandro Peña M

2011-08-01

143

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

Scientific Electronic Library Online (English)

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

Alejandro, Peña M.

2011-08-01

144

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

145

Retrosigmoid approach for vestibular neurectomy in Meniere's disease  

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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

146

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

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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

147

Vestibular Rehabilitation Affects Vestibular Asymmetry among Patients with Fall-Related Wrist Fractures - A Randomized Controlled Trial.  

Science.gov (United States)

Background: Fall-related fractures are an increasing problem for society. Dizziness is identified as a risk factor for falls and vestibular asymmetry is often found among patients with fall-related fractures. An option to prevent fall-related fractures may be to identify patients with vestibular asymmetry and to improve their balance and asymmetry by exercise. Objective: To examine whether vestibular rehabilitation improves vestibular function, balance and self-rated health among patients with fall-related wrist fractures. Methods: Sixty-eight persons (65 women) with fall-related wrist fractures, mean age 72 years (54-89) participated in this randomized controlled trial. The following tests and measurements were performed: head shake test to evaluate vestibular asymmetry as primary outcome measure, five clinical balance measures, a force plate to measure postural sway, a tuning fork to measure vibration and the EQ5D questionnaire to measure self-rated health. The intervention comprised group-based vestibular rehabilitation sessions conducted twice a week for 9 weeks. Results: Nystagmus occurred in the head shake test in 65% (44 of 68) of the patients, indicating vestibular asymmetry. More patients in the intervention group (6 of 21) than in the control group (0 of 23) changed from having nystagmus in the head shake test at baseline (indicating vestibular asymmetry) to not having nystagmus at follow-up, and more patients in the control group (3 of 9) than in the intervention group (0 of 3) changed from not having nystagmus at baseline to have nystagmus at follow-up (p < 0.00). No other changes occurred between the two groups between baseline and follow-up. At baseline, patients with vestibular asymmetry had more balance deficits and increased postural sway compared to patients without (p = 0.00-0.05). Conclusion: Group sessions with vestibular rehabilitation twice a week for 9 weeks affected the occurrence of vestibular asymmetry positively among patients having vestibular asymmetry. Patients with vestibular asymmetry had more balance deficits and increased postural sway than patients without vestibular asymmetry. Vestibular assessment is important, and, in patients with diagnosed vestibular asymmetry, vestibular rehabilitation may prove beneficial on balance and possibly reduce the risk of future falls. © 2014 S. Karger AG, Basel. PMID:25471256

Ekvall Hansson, Eva; Dahlberg, Leif E; Magnusson, Måns

2014-12-01

148

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

Directory of Open Access Journals (Sweden)

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

149

Task, muscle and frequency dependent vestibular control of posture  

Science.gov (United States)

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

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

2015-01-01

150

Enlarged vestibular aqueduct: Looking for genotypic-phenotypic correlations.  

Science.gov (United States)

The aim of this work is to provide a guide for clinical and genetic diagnosis and classification of the enlarged vestibular aqueduct syndrome based on a review of the literature and computerized databases with the words large and enlarged vestibular aqueduct. No more than 40 articles described association between the EVA phenotype and a known genetic alteration. Pendred's syndrome, distal renal tubular acidosis, waardenburg's syndrome, X-linked congenital mixed deafness, branchio-oto-renal syndrome, and oto-facio-cervical syndrome can express their genotypic alteration as enlarged vestibular aqueduct syndrome. We also found articles reporting familiar cases of enlarged vestibular aqueduct with no identified mutations in studied genes. PMID:16830115

González-García, José Angel; Ibáñez, Andrés; Ramírez-Camacho, Rafael; Rodríguez, Antonio; García-Berrocal, José Ramón; Trinidad, Almudena

2006-11-01

151

Inferior vestibular neuritis in a fighter pilot: a case report.  

Science.gov (United States)

Spatial disorientation in airplane pilots is a leading factor in many fatal flying accidents. Spatial orientation is the product of integrative inputs from the proprioceptive, vestibular, and visual systems. One condition that can lead to sudden pilot incapacitation in flight is vestibular neuritis. Vestibular neuritis is commonly diagnosed by a finding of unilateral vestibular failure, such as a loss of caloric response. However, because caloric response testing reflects the function of only the superior part of the vestibular nerve, it cannot detect cases of neuritis in only the inferior part of the nerve. We describe the case of a Chinese naval command fighter pilot who exhibited symptoms suggestive of vestibular neuritis but whose caloric response test results were normal. Further testing showed a unilateral loss of vestibular evoked myogenic potentials (VEMPs). We believe that this pilot had pure inferior nerve vestibular neuritis. VEMP testing plays a major role in the diagnosis of inferior nerve vestibular neuritis in pilots. We also discuss this issue in terms of aeromedical concerns. PMID:23780600

Xie, Su Jiang; Jia, Hong Bo; Xu, Po; Zheng, Ying Juan

2013-06-01

152

Vestibular function in HIV patients: preliminary report  

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Main purpose of this study was to evaluate vestibular function, focusing attention on percentage of peripheral damage in 30 HIV positive patients (23 male, 7 female), age range 26-68 years, belonging to Categories A-C of CDC classification of infection, underwent electronystagmography with bithermic stimulation according to Freyss (125 cc of water at 30 °C and 44 °C in 30 sec). The angular velocity of slow phase was considered as the main value of labirinthine functionality. Peripheral vest...

Teggi, R.; Giordano, L.; Pistorio, V.; Bussi, M.

2006-01-01

153

[EGG and nausea under vestibular stimulus].  

Science.gov (United States)

81 pilots were exposed to vestibular stimulus with Coriolis acceleration. They were divided into two groups, the first group consisted of 38 pilots with nausea symptoms, the second group 43 pilots without nausea symptom. Dominant frequency instability coefficient (DFIC), dominant power instability coefficient (DPIC), Tachygastria, Bradygastria and normal slow wave components (NSW) of the electrogastrogram (EGG) were analyzed. The results showed that Bradygastria and NSW of EGG were related to nausea symptom of pilots under Coriolis stimulation. PMID:11540385

Tian, G; Yu, Y; Liu, Z; Bai, G; Hu, S; Gu, Y

1997-10-01

154

Surgery of vestibular schwannomas: An institutional experience  

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AIMS: To report management results of vestibular schwannomas (VS) treated surgically in our institute, with particular reference to completeness of tumor excision, facial nerve and hearing preservation and complications of surgery. STUDY DESIGN AND SETTINGS: Retrospective study of 259 patients treated during the years 1988 to 2002. MATERIALS AND METHODS: The facial nerve function and hearing assessment was done according to House-Brackmann [HB] grading and pure tone audiometry (PTA) respectiv...

Jain Vijendra; Mehrotra Naveen; Sahu Rabi; Behari Sanjay; Banerji Deepu; Chhabra Devendra

2005-01-01

155

Norman Thagard Explains the Microgravity Vestibular Investigation  

Science.gov (United States)

In this video, astronaut Norman Thagard explains how he and his fellow STS-42 crew mates interacted with the rotator chair for the Microgravity Vestibular Investigations (MVI) onboard the International Microgravity Laboratory in July 1992. In the MVI, researchers from Canada, the United States, and other countries examined the effects of orbital flight on the human orientation system to obtain a better understanding of the mechanisms of adaptation to orbit.

1992-01-01

156

Vestibular prosthesis tested in rhesus monkeys  

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We are studying the effectiveness of a semicircular canal prosthesis to improve postural control, perception of spatial orientation, and the VOR in rhesus monkeys with bilateral vestibular hypofunction. Balance is examined by measuring spontaneous sway of the body during quiet stance and postural responses evoked by head turns and rotation of the support surface; perception is measured with a task derived from the subjective visual vertical (SVV) test during static and dynamic rotation in the...

Lewis, Richard F.; Haburcakova, Csilla; Gong, Wangsong; Lee, Daniel; Wall, Conrad; Thompson, Lara; Merfeld, Daniel M.

2011-01-01

157

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

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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 with gender, age, results from computerized vectoelectronystagmography and vertigo. Study type: Retrospective. MATERIALS AND METHODS:Twenty-two individuals were submitted to customized vestibular re...

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

2009-01-01

158

Síndrome do aqueduto vestibular alargado: uma causa de disacusia neurossensorial The large vestibular aqueduct syndrome: a cause of neurosensory dysacusia  

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TEMA: a síndrome do aqueduto vestibular alargado (SAVA) é caracterizada pelo alargamento do aqueduto vestibular associada a disacusia. O grau da perda auditiva é variável, podendo ser flutuante, progressiva ou súbita. Sintomas vestibulares podem estar presentes. O diagnóstico é realizado por exames de imagem. OBJETIVO: relatar um caso de SAVA. MÉTODO: lactente, gênero feminino, realizou tomografia computadorizada de ouvidos e exames de audição. RESULTADO: constatou-se alargamento d...

Daniela Polo Camargo da Silva; Jair Cortez Montovani; Danielle Tavares Oliveira; Marisa Portes Fioravanti; Ivanira Ayako Tamashiro

2008-01-01

159

Vestibular schwannoma: an unusual post radiotherapy response.  

Science.gov (United States)

Vestibular schwannoma is a relatively uncommon tumor. Although, it is benign but locally expansile and spreads to damage the adjacent structures. Treatment strategy includes surgery, Stereotactic Radiosurgery (SRS) either by standard or hypofractionated protocols. Due to its benign nature, radiation therapy cannot remove the tumor completely, instead radiation therapy halts the growth of vestibular schwannoma and inactivates this benign tumor. Response of radiation in the form of tumor shrinkage is seen 2 - 2.5 years after the radiations. We report a case of vestibular Schwannoma in which residual tumor of 3.1 cm size following subtotal resection was irradiated of the dose of 54 Gy in 30 equal fractions on 3-Dimensional Conformal Radiation Therapy (3-DCRT). A follow-up CT scan brain after 2 months of radiotherapy showed complete disappearance of the disease categorized as complete response. This is an unusual phenomenon and is likely due to the very rarely seen malignant transformation or presence of malignant component in this benign tumor. PMID:25518802

Uddin, Najam; Iqbal, Muhammad; Memon, Muhammad Ali; Farrukh, Salman

2014-11-01

160

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 SciELO Brazil | Language: Portuguese Abstract in portuguese 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.

 
 
 
 
161

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

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

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

2010-02-01

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Characterization of Neuronal Populations in the Human Trigeminal Ganglion and Their Association with Latent Herpes Simplex Virus-1 Infection  

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Following primary infection Herpes simplex virus-1 (HSV-1) establishes lifelong latency in the neurons of human sensory ganglia. Upon reactivation HSV-1 can cause neurological diseases such as facial palsy, vestibular neuritis or encephalitis. Certain populations of sensory neurons have been shown to be more susceptible to latent infection in the animal model, but this has not been addressed in human tissue. In the present study, trigeminal ganglion (TG) neurons expressing six neuronal marker...

Flowerdew, Sarah E.; Wick, Desiree; Himmelein, Susanne; Horn, Anja K. E.; Sinicina, Inga; Strupp, Michael; Brandt, Thomas; Theil, Diethilde; Hu?fner, Katharina

2013-01-01

163

Vestibular contribution to the planning of reach trajectories.  

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

Bockisch, Christopher J; Haslwanter, Thomas

2007-09-01

164

Virtual Neuron  

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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

165

Vestibular influences on autonomic cardiovascular control in humans  

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

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

1998-01-01

166

Facial myokymia as a presenting symptom of vestibular schwannoma.  

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

Joseph B

2002-07-01

167

Evidence for cognitive vestibular integration impairment in idiopathic scoliosis patients  

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

Mercier Pierre

2009-08-01

168

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

169

Vestibular schwannoma with contralateral facial pain – case report  

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

Ghodsi Mohammad

2003-03-01

170

The molecular biology and novel treatments of vestibular schwannomas.  

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Vestibular schwannomas are histopathologically benign tumors arising from the Schwann cell sheath surrounding the vestibular branch of cranial nerve VIII and are related to the NF2 gene and its product merlin. Merlin acts as a tumor suppressor and as a mediator of contact inhibition. Thus, deficiencies in both NF2 genes lead to vestibular schwannoma development. Recently, there have been major advances in our knowledge of the molecular biology of vestibular schwannomas as well as the development of novel therapies for its treatment. In this article the authors comprehensively review the recent advances in the molecular biology and characterization of vestibular schwannomas as well as the development of modern treatments for vestibular schwannoma. For instance, merlin is involved with a number of receptors including the CD44 receptor, EGFR, and signaling pathways, such as the Ras/raf pathway and the canonical Wnt pathway. Recently, merlin was also shown to interact in the nucleus with E3 ubiquitin ligase CRL4(DCAF1). A greater understanding of the molecular mechanisms behind vestibular schwannoma tumorigenesis has begun to yield novel therapies. Some authors have shown that Avastin induces regression of progressive schwannomas by over 40% and improves hearing. An inhibitor of VEGF synthesis, PTC299, is currently in Phase II trials as a potential agent to treat vestibular schwannoma. Furthermore, in vitro studies have shown that trastuzumab (an ERBB2 inhibitor) reduces vestibular schwannoma cell proliferation. With further research it may be possible to significantly reduce morbidity and mortality rates by decreasing tumor burden, tumor volume, hearing loss, and cranial nerve deficits seen in vestibular schwannomas. PMID:21800959

Fong, Brendan; Barkhoudarian, Garni; Pezeshkian, Patrick; Parsa, Andrew T; Gopen, Quinton; Yang, Isaac

2011-11-01

171

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 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

172

Vestibular prosthesis tested in rhesus monkeys.  

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We are studying the effectiveness of a semicircular canal prosthesis to improve postural control, perception of spatial orientation, and the VOR in rhesus monkeys with bilateral vestibular hypofunction. Balance is examined by measuring spontaneous sway of the body during quiet stance and postural responses evoked by head turns and rotation of the support surface; perception is measured with a task derived from the subjective visual vertical (SVV) test during static and dynamic rotation in the roll plane; and the angular VOR is measured during rotation about the roll, pitch, and yaw axes. After the normal responses are characterized, bilateral vestibular loss is induced with intratympanic gentamicin, and then multisite stimulating electrodes are chronically implanted into the ampullae of all three canals in one ear. The postural, perceptual, and VOR responses are then characterized in the ablated state, and then bilateral, chronic electrical stimulation is applied to the ampullary nerves using a prosthesis that senses angular head velocity in three-dimensions and uses this information to modulate the rate of current pulses provided by the implanted electrodes. We are currently characterizing two normal monkeys with these paradigms, and vestibular ablation and electrode implantation are planned for the near future. In one prior rhesus monkey tested with this approach, we found that a one-dimensional (posterior canal) prosthesis improved balance during head turns, perceived head orientation during roll tilts, and the VOR in the plane of the instrumented canal. We therefore predict that the more complete information provided by a three-dimensional prosthesis that modulates activity in bilaterally-paired canals will exceed the benefits provided by the one-dimensional, unilateral approach used in our preliminary studies. PMID:22254795

Lewis, Richard F; Haburcakova, Csilla; Gong, Wangsong; Lee, Daniel; Wall, Conrad; Thompson, Lara; Merfeld, Daniel M

2011-01-01

173

'Carrusel': an expert system for vestibular diagnosis.  

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Neuro-otology is the only field of otolaryngology in which diagnoses are mainly deductive. Although many technological advances have indeed occurred, the patient history still remains the most important part of the evaluation of a patient complaining of vertigo and/or dizziness. The use of artificial intelligence methods as an aid for the solution of clinical problems is not new. "Carrusel" is a Prolog build-up expert system dealing with the diagnosis of vestibular disorders that achieves a success rate of 97% when compared to the human experts involved in its design. PMID:2239202

Gavilán, C; Gallego, J; Gavilán, J

1990-01-01

174

Pharmacotherapy of vestibular and ocular motor disorders, including nystagmus.  

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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, and anti-migrainous medications; anti-depressants, anti-convulsants, and aminopyridines. A recovery from acute vestibular neuritis can be promoted by treatment with oral corticosteroids. Betahistine may reduce the frequency of attacks of Ménière's disease. The aminopyridines constitute a novel treatment approach for downbeat and upbeat nystagmus, as well as episodic ataxia type 2 (EA 2); these drugs may restore normal "pacemaker" activity to the Purkinje cells that govern vestibular and cerebellar nuclei. A limited number of trials indicate that baclofen improves periodic alternating nystagmus, and that gabapentin and memantine improve acquired pendular and infantile (congenital) nystagmus. Preliminary reports suggest suppression of square-wave saccadic intrusions by memantine, and ocular flutter by beta-blockers. Thus, although progress has been made in the treatment of vestibular neuritis, some forms of pathological nystagmus, and EA 2, controlled, masked trials are still needed to evaluate treatments for many vestibular and ocular motor disorders, including betahistine for Ménière's disease, oxcarbazepine for vestibular paroxysmia, or metoprolol for vestibular migraine. PMID:21461686

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

2011-07-01

175

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

176

Primary culture of human vestibular schwannomas.  

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Vestibular schwannomas (VSs) represent Schwann cell (SC) tumors of the vestibular nerve, compromising 10% of all intracranial neoplasms. VSs occur in either sporadic or familial (neurofibromatosis type 2, NF2) forms, both associated with inactivating defects in the NF2 tumor suppressor gene. Treatment for VSs is generally surgical resection or radiosurgery, however the morbidity of such procedures has driven investigations into less invasive treatments. Historically, lack of access to fresh tissue specimens and the fact that schwannoma cells are not immortalized have significantly hampered the use of primary cultures for investigation of schwannoma tumorigenesis. To overcome the limited supply of primary cultures, the immortalized HEI193 VS cell line was generated by transduction with HPV E6 and E7 oncogenes. This oncogenic transduction introduced significant molecular and phenotypic alterations to the cells, which limit their use as a model for human schwannoma tumors. We therefore illustrate a simplified, reproducible protocol for culture of primary human VS cells. This easily mastered technique allows for molecular and cellular investigations that more accurately recapitulate the complexity of VS disease. PMID:25079666

Schularick, Nathan M; Clark, J Jason; Hansen, Marlan R

2014-01-01

177

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

178

[Physiological evaluation of vestibular training load].  

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Objective. To evaluate the effects of vestibular training by observing the variations of the physiological indices. It is helpful in grasping the training load, setting down and implementing the training plan. Method. 10 healthy subjects received linear acceleration, continuous Coriolis acceleration and discontinuous Coriolis acceleration stimuli on different dates. The stimulus was stopped when there were slight autonomic nervous symptoms, ECG, EGG and BP were recorded before during and after the stimuli. Computerized Dynamic Posturography (correction of Postrograph) (CDP) was tested before and after experiment. Result. One subject finished the training of the three stimuli with only slight autonomic nervous symptoms. The CDP tests pre- and post-experiment indicated that for most subjects the contribution of vestibular function in maintaining dynamic posture equilibrium increased after the linear acceleration stimuli, but decreased after continuous Coriolis acceleration stimuli, and there was great individual difference after discontinuous Coriolis acceleration stimuli because the stimulation was relatively heavy. The equilibrium score in SOT2 decreased significantly after linear acceleration stimuli, and increased significantly after discontinuous Coriolis acceleration stimuli. Conclusion. The training methods we designed and used in this experiment are feasible, and the required training load can be reached. EGG, BP and the percentage of LF (low frequency) in ECG R-R power spectrum can reflect the subject's condition when the period stimuli stopped. It provided important reference in the determination of training stimulation load. PMID:11892746

Wang, L J; Pei, J C; Tong, B L; Liu, Z Q

2000-08-01

179

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

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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

180

[Observation of electronystagmogram in pilots under vestibular stimulation].  

Science.gov (United States)

The relationship between electronystagmogram(ENG) and intensity of vestibular stimulation was observed in 62 pilots. 31 pilots received low intensity vestibular stimulation and the other 31 pilots received higher intensity vestibular stimulation. Electronystagmogram were recorded and analysed. The results showed that there was no relationship between the ENG parameters and stimulation intensity, but both slow phase and fast phase velocities and amplitudes were lower under Coriolis acceleration stimulus, while all of them were higher under angular acceleration and angular stimulations. It was also found that the fast phase amplitude of ENG was related to motion sickness symptoms of the subjects. PMID:11541266

Tian, G; Yu, Y; Gu, Y; Hu, S; Bai, G; Gai, Y

1998-02-01

 
 
 
 
181

The Development of the Vestibular Apparatus Under Conditions of Weightlessness  

Science.gov (United States)

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

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

1984-01-01

182

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

Directory of Open Access Journals (Sweden)

Full Text Available The vestibular syndrome is a well-defined disease in domestic animals but little known in wild ones. Here this affection of central origin is described in a caquetic adult female giant anteater (Myrmecophaga tridactyla, which presented circling behavior, extensor hypermetry in thoracic limbs, head tilt and spontaneous horizontal and positional vertical nystagmus. The animal received tube feeding twice daily and dexamethasone was given subcutaneous once daily at the dosis of 6mg/kg, with a progressive improvement of health after the second day of treatment. Dose was reduced to a half from fourth to sixth day, and to a quarter on seventh day, when the animal died. On the fifth day, however, circle deambulation had ceased and hypermetry, head tilt and nystagmus were reduced. Treating vestibular syndrome is a challenge in wild animal practice. Treatment is affected by hyporexia and anorexia, making difficult the animals´ health improvement, which generally present muscle atrophy.A síndrome vestibular é uma afecção bem descrita em animais domésticos e pouco relatada em selvagens. Este relato descreveu essa afecção de origem central em uma fêmea adulta de tamanduá-bandeira (Myrmecophaga tridactyla, caquética, apresentando deambulação em círculos, hipermetria extensora nos membros torácicos, desvio da cabeça e nistagmo espontâneo horizontal e posicional vertical. O animal foi alimentado por sonda oral, 2x/dia e instituiu-se tratamento com dexametasona subcutânea na dose 6mg/kg, 1x/dia, com melhora progressiva a partir da segunda administração. A dose foi diminuída pela metade do quarto ao sexto dia, e reduzida novamente à metade no sétimo dia, quando ocorreu óbito. Entretanto, no quinto dia de tratamento, a deambulação em círculos foi interrompida, e a hipermetria, desvio da cabeça e nistagmo diminuídos. O tratamento de animais selvagens com síndrome vestibular é um desafio e é prejudicado pela hiporexia ou anorexia, dificultando a recuperação dos mesmos, que geralmente apresentam diminuição da massa muscular.

Leandro Luís Martins

2009-10-01

183

Effects of electrotactile vestibular substitution on rehabilitation of patients with bilateral vestibular loss.  

Science.gov (United States)

The present study evaluated the effectiveness of electrotactile tongue biofeedback (BrainPort((R))) as a sensory substitute for the vestibular apparatus in patients with bilateral vestibular loss (BVL) who did not have a good response to conventional vestibular rehabilitation (VR). Seven patients with BVL were trained to use the device. Stimulation on the surface of the tongue was created by a dynamic pattern of electrical pulses and the patient was able to adjust the intensity of stimulation and spatially centralize the stimulus on the electrode array. Patients were directed to continuously adjust head orientation and to maintain the stimulus pattern at the center of the array. Postural tasks that present progressive difficulties were given during the use of the device. Pre- and post-treatment distribution of the sensory organization test (SOT) composite score showed an average value of 38.3+/-8.7 and 59.9+/-11.3, respectively, indicating a statistically significant improvement (p=0.01). Electrotactile tongue biofeedback significantly improved the postural control of the study group, even if they had not improved with conventional VR. The electrotactile tongue biofeedback system was able to supply additional information about head position with respect to gravitational vertical orientation in the absence of vestibular input, improving postural control. Patients with BVL can integrate electrotactile information in their postural control in order to improve stability after conventional VR. These results were obtained and verified not only by the subjective questionnaire but also by the SOT composite score. The limitations of the study are the small sample size and short duration of the follow-up. The current findings show that the sensory substitution mediated by electrotactile tongue biofeedback may contribute to the improved balance experienced by these patients compared to VR. PMID:20398733

Barros, Camila Giacomo Carneiro; Bittar, Roseli Saraiva Moreira; Danilov, Yuri

2010-06-01

184

Effects of conventional versus multimodal vestibular rehabilitation on functional capacity and balance control in older people with chronic dizziness from vestibular disorders: design of a randomized clinical trial  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background There are several protocols designed to treat vestibular disorders that focus on habituation, substitution, adaptation, and compensation exercises. However, protocols that contemplate not only vestibular stimulation but also other components that are essential to the body balance control in older people are rare. This study aims to compare the effectiveness of two vestibular rehabilitation protocols (conventional versus multimodal) on the functional capaci...

Ricci Natalia; Aratani Mayra; Caovilla Heloisa; Ganança Fernando

2012-01-01

185

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

186

A vestibular prosthesis with highly-isolated parallel multichannel stimulation.  

Science.gov (United States)

This paper presents an implantable vestibular stimulation system capable of providing high flexibility independent parallel stimulation to the semicircular canals in the inner ear for restoring three-dimensional sensation of head movements. To minimize channel interaction during parallel stimulation, the system is implemented with a power isolation method for crosstalk reduction. Experimental results demonstrate that, with this method, electrodes for different stimulation channels located in close proximity ( mm) can deliver current pulses simultaneously with minimum inter-channel crosstalk. The design features a memory-based scheme that manages stimulation to the three canals in parallel. A vestibular evoked potential (VEP) recording unit is included for closed-loop adaptive stimulation control. The main components of the prototype vestibular prosthesis are three ASICs, all implemented in a 0.6- ?m high-voltage CMOS technology. The measured performance was verified using vestibular electrodes in vitro. PMID:25073175

Jiang, Dai; Cirmirakis, Dominik; Demosthenous, Andreas

2015-02-01

187

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

188

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

Scientific Electronic Library Online (English)

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

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

189

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

Scientific Electronic Library Online (English)

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

190

Asymmetric vestibular evoked myogenic potentials in unilateral Menière patients  

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

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

2010-01-01

191

Incidence, seasonality and comorbidity in vestibular neuritis.  

Science.gov (United States)

Aims of the present study were: (1) to assess the incidence of vestibular neuritis (VN) in the adult population in two cities in Croatia, (2) to identify distribution of new VN cases in the different months and seasons by years, and (3) to identify comorbidities associated with VN. This is a prospective, population-based study conducted in the cities of Zagreb and Velika Gorica, Croatia in the 2011-2012 period. All diagnoses were confirmed either with caloric test or vestibular evoked myogenic potentials within 7 days of symptom onset. Following clinical parameters were collected from all patients: age, gender, side of the lesion, month and season of symptoms onset and comorbidities. We identified 79 new cases of VN (34 in 2011, 45 in 2012). The male to female ratio was 1.1:1. The mean age at the onset of the disease was 52.3 (range 20-86) years. The average annual incidence was 11.7 per 100,000 (95 % CI 7.8-15.6) in the 2011 period and 15.5 per 100,000 (95 % CI 11.0-20.0) in the 2012 period. For both years there was no statistically significant uneven distribution in the different months or seasons by years. The most frequent comorbidities present in VN patients were hypertension (30.4 %), diabetes mellitus (8.9 %), hyperlipidemia (7.5 %) and hypothyreosis (6.3 %). Our study has shown higher incidence of VN than previously reported. We have found no evidence of seasonality of VN and significant proportion of VN patients older than 50 years who had vascular risk factors present. PMID:25085434

Adamec, Ivan; Krbot Skori?, Magdalena; Handži?, Jadranka; Habek, Mario

2015-01-01

192

[Vestibularly displaced flap with bone augmentation].  

Science.gov (United States)

The aim of this study is to achieve esthetic gingival contours with the help of less traumatic mucogingival surgeries. 9 Patients were operated with horizontal deficiencies in 9 edentulous sites, planned to be restored with fixed partial dentures. In all cases there was lack of keratinized tissues. Temporary bridges were fabricated to all patients. Before surgery the bridges were removed and the abutment teeth were additionally cleaned with ultrasonic device. A horizontal incision was made from lingual (palatal) side between the abutment teeth, which was connected with two vertical releasing incisions to the mucogingival junction from the vestibular side. The horizontal incision was made on a distance 6-10 mm from the crest of the alveolar ridge. A partial thickness flap in the beginning 3-5 mm, then a full thickness flap up to the mucogingival junction, then a partial thickness flap was made. The flap was mobilized and displaced vestibularly. In the apical part the cortical bone was perforated, graft material was put and the flap was sutured. In all 9 cases the horizontal defect was partially or fully eliminated. The width of the keratinized tissues was also augmented in all cases. The postoperative healing was without complications, discomfort and painless. The donor sites also healed without complications. The application of Solcoseryl Dental Adhesive Paste 3 times a day for 7-10 days helped for painless healing of the donor site. The offered method of soft tissue and bone augmentation is effective in the treatment of horizontal defects of edentulous alveolar ridges of not big sizes. It makes possible to achieve esthetic results without traumatizing an additional donor-site. PMID:19644187

Bakalian, V L

2009-01-01

193

Vestibular adaptation to space in monkeys  

Science.gov (United States)

Otolith-induced eye movements of rhesus monkeys were studied before and after the 1989 COSMOS 2044 and the 1992 to 1993 COSMOS 2229 flights. Two animals flew in each mission for approximately 2 weeks. After flight, spatial orientation of the angular vestibulo-ocular reflex was altered. In one animal the time constant of postrotatory nystagmus, which had been shortened by head tilts with regard to gravity before flight, was unaffected by the same head tilts after flight. In another animal, eye velocity, which tended to align with a gravitational axis before flight, moved toward a body axis after flight. This shift of orientation disappeared by 7 days after landing. After flight, the magnitude of compensatory ocular counter-rolling was reduced by about 70% in both dynamic and static tilts. Modulation in vergence in response to naso-occipital linear acceleration during off-vertical axis rotation was reduced by more than 50%. These changes persisted for 11 days after recovery. An up and down asymmetry of vertical nystagmus was diminished for 7 days. Gains of the semicircular canal-induced horizontal and vertical angular vestibulo-ocular reflexes were unaffected in both flights, but the gain of the roll angular vestibulo-ocular reflex was decreased. These data indicate that there are short- and long-term changes in otolith-induced eye movements after adaptation to microgravity. These experiments also demonstrate the unique value of the monkey as a model for studying effects of vestibular adaptation in space. Eye movements can be measured in three dimensions in response to controlled vestibular and visual stimulation, and the results are directly applicable to human beings. Studies in monkeys to determine how otolith afferent input and central processing is altered by adaptation to microgravity should be an essential component of future space-related research.

Dai, M.; Raphan, T.; Kozlovskaya, I.; Cohen, B.

1998-01-01

194

Vestibular findings associated with chronic noise induced hearing impairment.  

Science.gov (United States)

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

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

1994-11-01

195

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 | Language: 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

196

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

Science.gov (United States)

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

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

1995-01-01

197

[Purkinje's cells in the vestibular and proprioceptive segments of rat's cerebellum following 14-day space flight].  

Science.gov (United States)

Quantitative cytochemical and morphometric methods were used to investigate cytochrome oxidase activity and sizes of bodies and nuclei of Purkinje's cells in the medical nodulus and upper central lobule of the vermis obtained from rats sacrificed in 5-6 hours of landing after the 14-day SLS-2 mission of NASA space "shuttle" Columbia (STS-58). The reduced cytochrome oxidase activity was explained by suppression of the functional activity of Purkinje's cells in microgravity. Results of the investigations suggest weakening of the regulatory effect of the vermis Purkinje's cells on giant neurons of the dorsocaudal segment of Deiters nucleus. They also strengthen the earlier hypothesis that space flight decays the inhibitory effect of nodulus Purkinje's cells on the medial vestibular nucleus for the reason of change in the "velocity storage" in mammals during and after flight. PMID:19943521

Krasnov, I B; Krasnikov, G V

2009-01-01

198

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 SciELO Brazil | Language: English Abstract in portuguese 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

199

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 | Language: 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

200

Síndrome do aqueduto vestibular alargado: uma causa de disacusia neurossensorial / The large vestibular aqueduct syndrome: a cause of neurosensory dysacusia  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese TEMA: a síndrome do aqueduto vestibular alargado (SAVA) é caracterizada pelo alargamento do aqueduto vestibular associada a disacusia. O grau da perda auditiva é variável, podendo ser flutuante, progressiva ou súbita. Sintomas vestibulares podem estar presentes. O diagnóstico é realizado por exames [...] de imagem. OBJETIVO: relatar um caso de SAVA. MÉTODO: lactente, gênero feminino, realizou tomografia computadorizada de ouvidos e exames de audição. RESULTADO: constatou-se alargamento do aqueduto vestibular maior que 1,5mm de diâmetro e perda auditiva neurossensorial à direita. CONCLUSÃO: com a avaliação auditiva precoce é possível o diagnóstico da disacusia, mesmo em crianças com disacusias unilaterais. Embora a literatura consultada mostre que o diagnóstico da SAVA ocorra tardiamente, no presente caso, o diagnóstico etiológico foi possibilitado pela tomografia computadorizada. Abstract in english BACKGROUND: the large vestibular aqueduct syndrome (LVAS) is characterized by the enlargement of the vestibular aqueduct associated with sensorioneural hearing loss. The level of hearing loss varies and may be fluctuant, progressive or sudden. Vestibular symptoms may be present. The diagnosis is rea [...] ched by imaging methods. AIM: To report an LVAS case. METHOD: a female infant was submitted to a computerized tomography of the ears and to audiologic tests. RESULTS: enlargement of the vestibular aqueduct of more than 1.5mm and sensorioneural hearing loss in the right ear were observed. CONCLUSION: with an early hearing evaluation it is possible to diagnose hearing loss, even in children were this loss is unilateral. Although the literature indicates that the diagnosis of LVAS occurs at a later age, in this case the etiologic diagnosis was enabled by computerized tomography.

Daniela Polo Camargo da, Silva; Jair Cortez, Montovani; Danielle Tavares, Oliveira; Marisa Portes, Fioravanti; Ivanira Ayako, Tamashiro.

2008-06-01

 
 
 
 
201

Síndrome do aqueduto vestibular alargado: uma causa de disacusia neurossensorial The large vestibular aqueduct syndrome: a cause of neurosensory dysacusia  

Directory of Open Access Journals (Sweden)

Full Text Available TEMA: a síndrome do aqueduto vestibular alargado (SAVA é caracterizada pelo alargamento do aqueduto vestibular associada a disacusia. O grau da perda auditiva é variável, podendo ser flutuante, progressiva ou súbita. Sintomas vestibulares podem estar presentes. O diagnóstico é realizado por exames de imagem. OBJETIVO: relatar um caso de SAVA. MÉTODO: lactente, gênero feminino, realizou tomografia computadorizada de ouvidos e exames de audição. RESULTADO: constatou-se alargamento do aqueduto vestibular maior que 1,5mm de diâmetro e perda auditiva neurossensorial à direita. CONCLUSÃO: com a avaliação auditiva precoce é possível o diagnóstico da disacusia, mesmo em crianças com disacusias unilaterais. Embora a literatura consultada mostre que o diagnóstico da SAVA ocorra tardiamente, no presente caso, o diagnóstico etiológico foi possibilitado pela tomografia computadorizada.BACKGROUND: the large vestibular aqueduct syndrome (LVAS is characterized by the enlargement of the vestibular aqueduct associated with sensorioneural hearing loss. The level of hearing loss varies and may be fluctuant, progressive or sudden. Vestibular symptoms may be present. The diagnosis is reached by imaging methods. AIM: To report an LVAS case. METHOD: a female infant was submitted to a computerized tomography of the ears and to audiologic tests. RESULTS: enlargement of the vestibular aqueduct of more than 1.5mm and sensorioneural hearing loss in the right ear were observed. CONCLUSION: with an early hearing evaluation it is possible to diagnose hearing loss, even in children were this loss is unilateral. Although the literature indicates that the diagnosis of LVAS occurs at a later age, in this case the etiologic diagnosis was enabled by computerized tomography.

Daniela Polo Camargo da Silva

2008-06-01

202

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

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There is no consensus on the relevance of factors that influence gender differences in the behavior of muscles. Some studies have reported a relationship between muscle tension and amplitude of the vestibular evoked myogenic potential; others, that results depend on which muscles are studied or on how much load is applied. AIMS: This study aims to compare vestibular evoked myogenic potential parameters between genders in young individuals. METHODS: Eighty young adults were selected - 40 men a...

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

2011-01-01

203

Current treatment of nasal vestibular stenosis with CO2-laser surgery: prolonged vestibular stenting versus intraoperative mitomycin application. A case series of 3 patients.  

Science.gov (United States)

These case studies describe three cases of unilateral nasal vestibular stenoses caused by chemical cauterization. Each case was treated with CO2-laser surgery together with intraoperative topic application of mitomycin or prolonged vestibular stenting for prevention of restenosis. Two patients received intraoperative mitomycin application and one patient received prolonged vestibular stenting. Results were documented using high-resolution photographs. The follow up period ranged from 1 year and 3 months to 4 years and 9 months. All patients improved after CO2-laser surgery. No complications were reported. We consider CO2-laser surgery for relief of nasal vestibular stenosis as a feasible surgical technique for relieve of nasal vestibular stenosis. Prolonged vestibular stenting seems to be an important factor for the prevention of restenosis in which the value of intraoperative mitomycin application without prolonged vestibular stenting remains uncertain. PMID:25282303

van Schijndel, Olaf; van Heerbeek, Niels; Ingels, Koen J A O

2014-12-01

204

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 SciELO Brazil | Language: Portuguese Abstract in portuguese 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

205

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  

Directory of Open Access Journals (Sweden)

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: Este 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.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

2012-02-01

206

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 | Language: 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

207

Avaliação oculomotora em pacientes com disfunção vestibular periférica / Oculomotor evaluation in patients with peripheral vestibular dysfunction  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese OBJETIVO: Verificar se os parâmetros dos movimentos sacádicos fixos e randomizados, do rastreio pendular e do nistagmo optocinético na vectonistagmografia digital podem apresentar alterações em pacientes com hipótese diagnóstica de disfunção vestibular periférica. MÉTODO: Foram avaliados 60 paciente [...] s, de ambos os sexos, com tontura de origem vestibular periférica e idade entre 12 e 82 anos. Os achados foram comparados com um padrão de normalidade para os parâmetros dos movimentos oculares estudados. RESULTADOS: Os movimentos sacádicos fixos estavam alterados em 100% dos casos quanto à latência e em 35% quanto à velocidade; os randomizados estavam alterados em 100% quanto à latência, em 78,3% quanto à precisão e 1,7% quanto à velocidade; o rastreio pendular apresentou alteração do ganho nas freqüências de 0,1Hz em 15%, 0,2Hz em 21,7% e 0,4Hz em 13,3%; o nistagmo optocinético apresentou alteração da velocidade angular da componente lenta em 1,7% e do ganho em 5%. CONCLUSÕES: A latência e a velocidade dos movimentos sacádicos fixos; a latência, a precisão e a velocidade dos movimentos randomizados; o ganho do rastreio pendular; a velocidade angular da componente lenta e o ganho do nistagmo optocinético na vectonistagmografia digital podem apresentar alterações em pacientes com hipótese diagnóstica de disfunção vestibular periférica. Abstract in english AIM: To assess whether or not the parameters of fixed and randomized saccadic movements, of pendular tracking and of optokinetic nystagmus in the digital vectonystagmography may show abnormalities in patients with possible diagnosis of peripheral vestibular dysfunction. METHOD: 60 patients with dizz [...] iness of peripheral vestibular origin, from 12 to 82 years of age, males and females, were evaluated in the Universidade Federal de São Paulo. Ocular movement parameter findings were compared to a normal pattern. RESULTS: Fixed saccadic movements were altered in 100% of the cases as to latency, and in 35.0% of the cases as to speed; the randomized saccadic movements were altered in 100% of the cases as to latency, in 78.3% as to precision, and in 1.7% as to speed; the pendular tracking showed a gain alteration in the frequencies of 0.1 Hz in 15% of the cases, 0.2 Hz in 21.7%, and 0.4 Hz in 13.3%; the optokinetic nystagmus showed an alteration of the angular speed in the slow component in 1.7% of the cases, and in gain in 5.0%. CONCLUSION: Fixed saccadic movement latency and speed, randomized saccadic movement latency, precision and speed, pendular tracking gain, slow component angular speed, and optokinetic nystagmus gain in the digital vectonystagmography may show abnormalities in patients with possible diagnosis of peripheral vestibular dysfunction.

Vanessa Costa, Tuma; Cristina Freitas, Ganança; Maurício Malavasi, Ganança; Heloisa Helena, Caovilla.

2006-06-01

208

Avaliação oculomotora em pacientes com disfunção vestibular periférica Oculomotor evaluation in patients with peripheral vestibular dysfunction  

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Full Text Available OBJETIVO: Verificar se os parâmetros dos movimentos sacádicos fixos e randomizados, do rastreio pendular e do nistagmo optocinético na vectonistagmografia digital podem apresentar alterações em pacientes com hipótese diagnóstica de disfunção vestibular periférica. MÉTODO: Foram avaliados 60 pacientes, de ambos os sexos, com tontura de origem vestibular periférica e idade entre 12 e 82 anos. Os achados foram comparados com um padrão de normalidade para os parâmetros dos movimentos oculares estudados. RESULTADOS: Os movimentos sacádicos fixos estavam alterados em 100% dos casos quanto à latência e em 35% quanto à velocidade; os randomizados estavam alterados em 100% quanto à latência, em 78,3% quanto à precisão e 1,7% quanto à velocidade; o rastreio pendular apresentou alteração do ganho nas freqüências de 0,1Hz em 15%, 0,2Hz em 21,7% e 0,4Hz em 13,3%; o nistagmo optocinético apresentou alteração da velocidade angular da componente lenta em 1,7% e do ganho em 5%. CONCLUSÕES: A latência e a velocidade dos movimentos sacádicos fixos; a latência, a precisão e a velocidade dos movimentos randomizados; o ganho do rastreio pendular; a velocidade angular da componente lenta e o ganho do nistagmo optocinético na vectonistagmografia digital podem apresentar alterações em pacientes com hipótese diagnóstica de disfunção vestibular periférica.AIM: To assess whether or not the parameters of fixed and randomized saccadic movements, of pendular tracking and of optokinetic nystagmus in the digital vectonystagmography may show abnormalities in patients with possible diagnosis of peripheral vestibular dysfunction. METHOD: 60 patients with dizziness of peripheral vestibular origin, from 12 to 82 years of age, males and females, were evaluated in the Universidade Federal de São Paulo. Ocular movement parameter findings were compared to a normal pattern. RESULTS: Fixed saccadic movements were altered in 100% of the cases as to latency, and in 35.0% of the cases as to speed; the randomized saccadic movements were altered in 100% of the cases as to latency, in 78.3% as to precision, and in 1.7% as to speed; the pendular tracking showed a gain alteration in the frequencies of 0.1 Hz in 15% of the cases, 0.2 Hz in 21.7%, and 0.4 Hz in 13.3%; the optokinetic nystagmus showed an alteration of the angular speed in the slow component in 1.7% of the cases, and in gain in 5.0%. CONCLUSION: Fixed saccadic movement latency and speed, randomized saccadic movement latency, precision and speed, pendular tracking gain, slow component angular speed, and optokinetic nystagmus gain in the digital vectonystagmography may show abnormalities in patients with possible diagnosis of peripheral vestibular dysfunction.

Vanessa Costa Tuma

2006-06-01

209

Enhancement of Otolith Specific Ocular Responses Using Vestibular Stochastic Resonance  

Science.gov (United States)

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

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

2011-01-01

210

Vestibular disorders and dual task performance: Impairment when walking a straight path  

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Locomotion is impaired in some people with vestibular disorders. Performance on cognitive tasks is also impaired in many people with vestibular disorders. The goal of this study was to determine if patients with vestibular disorders have decreased ability to complete a dual task performance involving a cognitive task, an additional motor task or both tasks, combined along a linear path. Subjects were normal, had benign paroxysmal positional vertigo, or had various vestibular disorders that ca...

Roberts, Jess C.; Cohen, Helen S.; Sangi-haghpeykar, Haleh

2011-01-01

211

Visuo-spatial memory enhancement by galvanic vestibular stimulation: A preliminary report  

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Background and Aim: Navigation information is processed and stored in different brain areas such as hippocampus. Since multiple pathways has been reported between vestibular nuclei and hippocampus and also cognitive dysfunction specifically in spatial memory is induced by vestibular deficits, it can be assumed that vestibular system stimulation ameliorates spatial memory. The aim of study was to evaluate the effect of galvanic vestibular stimulation on normal individual’s spatial memory.Met...

Fatemehsadat Ghaheri; Mansoureh Adel Ghahraman; Farnoush Jarollahi; Shohreh Jalaie

2014-01-01

212

Are Crossed Actions of Reticulospinal and Vestibulospinal Neurons on Feline Motoneurons Mediated by the Same or Separate Commissural Neurons?  

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Both reticulo- and vestibulospinal neurons coordinate the activity of ipsilateral and contralateral limb muscles. The aim of this study was to investigate whether their actions on contralateral motoneurons are mediated via common interneurons. Two series of experiments were made on deeply anesthetized cats. First, the effects of stimuli applied within the lateral vestibular nucleus and to reticulospinal tract fibers within or close to the medial longitudinal fascicle in the medulla were teste...

Krutki, Piotr; Jankowska, Elzbieta; Edgley, Stephen A.

2003-01-01

213

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.

214

Quantification of vestibular-induced eye movements in zebrafish larvae  

Directory of Open Access Journals (Sweden)

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

Mo Weike

2010-09-01

215

Isolated floccular infarction: impaired vestibular responses to horizontal head impulse.  

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Isolated floccular infarction is extremely rare, and impairments of the vestibulo-ocular reflex (VOR) have not been explored in humans with isolated floccular lesions. The purpose of this study was to examine and report selective impairment of VOR in response to high acceleration using head impulse in a patient with isolated floccular infarction. The patient underwent bedside and laboratory evaluation of vestibular function, which included video-oculography, ocular torsion and the subjective visual vertical, cervical and ocular vestibular-evoked myogenic potentials, bithermal caloric irrigation, rotatory chair test, and the head impulse test (HIT) using search coils. A 70-year-old woman with a unilateral floccular infarction presented with an acute vestibular syndrome with spontaneous nystagmus beating to the lesion side, impaired ipsilesional pursuit, contraversive ocular torsion and tilt of the subjective visual vertical. With rotatory chair testing at low frequencies, horizontal VOR gains were increased. However, VOR gains were decreased with the higher-frequency, higher-speed HIT. While HIT is often normal in patients with central vestibular disorders, decreased HIT responses do not exclude an isolated cerebellar lesion as a cause of the acute vestibular syndrome. PMID:23370610

Park, Hong-Kyun; Kim, Ji-Soo; Strupp, Michael; Zee, David S

2013-06-01

216

Surgery of vestibular schwannomas: An institutional experience  

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Full Text Available AIMS: To report management results of vestibular schwannomas (VS treated surgically in our institute, with particular reference to completeness of tumor excision, facial nerve and hearing preservation and complications of surgery. STUDY DESIGN AND SETTINGS: Retrospective study of 259 patients treated during the years 1988 to 2002. MATERIALS AND METHODS: The facial nerve function and hearing assessment was done according to House-Brackmann [HB] grading and pure tone audiometry (PTA respectively. All patients were operated by retro-mastoid sub-occipital approach. RESULTS: Most patients had large tumors and had no useful hearing (90%, had disabling cerebellar ataxia (88% and presented with features of raised intra-cranial pressure (45%. Large sized tumors were in 41.3% and giant sized tumors were in 56% cases. Complete tumor excision was carried out in 96.5% and anatomical preservation of facial nerve was achieved in 79.2% cases. Hearing preservation was achieved in 8 patients. Cerebrospinal fluid leak with or without meningitis and transient lower cranial nerve paresis were common complications. The mortality was 6%. CONCLUSIONS: With experience, complete tumor excision with good facial nerve preservation can be achieved in large tumors. Hearing preservation is difficult in bigger tumors. Prevention and control of infection was a major concern.

Jain Vijendra

2005-01-01

217

Large vestibular aqueduct syndrome: a case study.  

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A 23-month-old female was referred for hearing aid fitting after failing newborn hearing screening and being diagnosed with significant hearing loss through subsequent diagnostic testing. Auditory brainstem response (ABR) and behavioral testing revealed a moderate-to-severe bilateral mixed hearing loss. Prior to the hearing aid evaluation, tympanostomy tubes had been placed bilaterally with little or no apparent change in hearing sensitivity. Initial testing during the hearing aid fitting confirmed earlier findings, but abnormal middle ear results were observed, requiring referral for additional otologic management. Following medical clearance, binaural digital programmable hearing aids were fit using Desired Sensation Level parameters. Behavioral testing and probe microphone measures showed significant improvements in audibility. Decrease in hearing sensitivity was observed six months following hearing aid fitting. Radiological studies, ordered due to the mixed component and decreased hearing sensitivity, revealed large vestibular aqueduct syndrome (LVAS). Based on the diagnosis of LVAS, a cochlear implant was placed on the right ear; almost immediate speech-language gains were observed. PMID:16515134

Clark, Jackie L; Roeser, Ross J

2005-01-01

218

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

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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

219

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

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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

220

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

Scientific Electronic Library Online (English)

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

 
 
 
 
221

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

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Full Text Available Os potenciais evocados miogênicos vestibulares são reflexos vestíbulo-cervicais, decorrentes da estimulação do sáculo com sons de forte intensidade. São necessários parâmetros de normalidade para indivíduos jovens normais, utilizando-se estímulos a baixas frequências, as quais configuram a região de maior sensibilidade desse órgão sensorial. OBJETIVO: Realizar normatização do potencial evocado miogênico vestibular para baixas frequências de estimulação. MATERIAL E MÉTODO: Captou-se o potencial evocado miogênico vestibular em 160 orelhas, no músculo esternocleidomastoideo, de forma ipsilateral, por meio da promediação de 200 tone bursts, frequência de 250 Hz, intensidade de 95 dB NAn. FORMA DE ESTUDO: Estudo de coorte contemporânea com corte transversal. RESULTADOS: Aplicando-se o teste T de Student ou o Teste de Mann-Whitney, não foi constatada diferença significativa para parâmetros do potencial evocado miogênico vestibular entre os gêneros, para p Vestibular evoked myogenic potentials are vestibulocervical reflexes resulting from sacculus stimulation with strong intensity sounds. Normality parameters are necessary for young normal individuals, using low frequency stimuli, which configure the most sensitive region of this sensory organ. AIM: To establish vestibular evoked myogenic potential standards for low frequency stimulation. MATERIAL AND METHOD: Vestibular evoked myogenic potential was captured from 160 ears, in the ipsilateral sternocleidomastoid muscle, using 200 averaged tone-burst stimuli, at 250 Hz, with an intensity of 95 dB NAn. CASE STUDY: Clinical observational cross-sectional. RESULTS: Neither the student's t-test nor the Mann-Whitney test showed a significant difference in latency or vestibular evoked myogenic potential amplitudes, for p <; 0.05. Irrespective of gender, we found latencies of p13-n23 and p13-n23 interpeaks of 13.84 ms (± 1.41, 23.81 ms (±1.99 and 10.62 ms (± 6.56, respectively. Observed values for amplitude asymmetry between the ears were equal to 13.48% for females and 3.81% for males. CONCLUSION: Low frequency stimuli generate vestibular evoked myogenic potentials, with adequate morphology and amplitude, thereby enabling the establishment of standard values for normal individuals at this frequency.

Aline Cabral de Oliveira

2011-12-01

222

Normal pressure hydrocephalus after gamma knife radiosurgery for vestibular schwannoma  

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

Mohammed T

2010-01-01

223

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

224

Visual gravitational motion and the vestibular system in humans  

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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

225

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

226

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

227

Superior Semicircular Canal Dehiscence Syndrome without Vestibular Symptoms  

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

Emidio Oliveira, Teixeira; Marconi Teixeira, Fonseca.

2014-04-01

228

Treatment of Large and Giant Residual and Recurrent Vestibular Schwannomas  

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This report is a retrospective analysis of the surgical outcome of 15 patients (8 females, 7 males; mean age, 37.8 years) with residual or recurrent vestibular schwannomas operated on between 1987 and 2005. These 15 patients were part of a larger series of 252 consecutive vestibular schwannoma excisions. Tumors were classified as large (10) when their diameter exceeded 3.5 cm and giant (5) when their diameter exceeded 4.5 cm. All patients had previously undergone surgery. Hearing was lost in ...

Ramina, Ricardo; Coelho Neto, Mauri?cio; Bordignon, Kelly Cristina; Mattei, Tobias; Clemente, Roge?rio; Pires Aguiar, Paulo Henrique

2007-01-01

229

Vestibular Rehabilitation In Unilateral Peripheral Vestibulopathy: A Preliminary Report  

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

Birgul DONMEZ

2008-06-01

230

Neurohumoral reactions to long-term vestibular stimulation in man.  

Science.gov (United States)

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

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

1993-02-01

231

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

Scientific Electronic Library Online (English)

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

Maysa Bastos, Rabelo; Corona, Ana Paula.

2014-10-01

232

Can an electro-tactile vestibular substitution system improve balance in patients with unilateral vestibular loss under altered somatosensory conditions from the foot and ankle?  

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This pilot study aimed at assessing the feasibility and the effectiveness of an electro-tactile vestibular substitution system (EVSS) in patients with unilateral vestibular loss under normal and altered somatosensory conditions from the foot and ankle. Four unilateral vestibular-defective patients voluntarily participated in the experiment. They were asked to stand upright as still as possible with their eyes closed in two Normal and Altered foot and ankle sensory conditions. These conditions...

Vuillerme, N.; Hlavackova, P.; Franco, C.; Diot, B.; Demongeot, J.; Payan, Yohan

2011-01-01

233

Extracting phase-dependent human vestibular reflexes during locomotion using both time and frequency correlation approaches.  

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Daily activities, such as walking, may require dynamic modulation of vestibular input onto motoneurons. This dynamic modulation is difficult to identify in humans due to limitations in the delivery and analysis of current vestibular probes, such as galvanic vestibular stimulation. Stochastic vestibular stimulation, however, provides an alternative method to extract human vestibular reflexes. Here, we used time-dependent coherence and time-dependent cross-correlation, coupled with stochastic vestibular stimulation, to investigate the phase dependency of human vestibular reflexes during locomotion. We found that phase-dependent activity from the medial gastrocnemius muscles is correlated with the vestibular signals over the 2- to 20-Hz bandwidth during the stance phase of locomotion. Vestibular-gastrocnemius coherence and time-dependent cross-correlations reached maximums at 21 ± 4 and 23 ± 8% of the step cycle following heel contact and before the period of maximal electromyographic activity (38 ± 5%). These results demonstrate 1) the effectiveness of these techniques in extracting the phase-dependent modulation of vestibulomuscular coupling during a cyclic task; 2) that vestibulomuscular coupling is phasically modulated during locomotion; and 3) that the period of strongest vestibulomuscular coupling does not correspond to the period of maximal electromyographic activity in the gastrocnemius. Therefore, we have shown that stochastic vestibular stimulation, coupled with time-frequency decomposition, provides an effective tool to assess the contribution of vestibular ex-afference to the muscular control during locomotion. PMID:21868684

Blouin, Jean-Sébastien; Dakin, Christopher J; van den Doel, Kees; Chua, Romeo; McFadyen, Bradford J; Inglis, John Timothy

2011-11-01

234

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

235

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

236

Monoamines (norepinephrine, dopamine, serotonin) in the rat medial vestibular nucleus: endogenous levels and turnover.  

Science.gov (United States)

Monoamine (norepinephrine, dopamine, serotonin) and metabolite endogenous levels were determined in the rat medial vestibular nucleus (MVN) using HPLC with electrochemical detection. As a comparison, the locus coeruleus (LC) and dorsal raphe nucleus (RD) which contain the cell bodies of MVN noradrenergic and serotoninergic neurons respectively were also analyzed. Norepinephrine (NE) and serotonin (5-HT) basal levels of MVN were high (33.8 and 39.2pmol/mg protein respectively) but lesser than in LC or RD. Great amounts of MHPG and 5-HIAA were also present in the MVN. The turnover of NE assessed both from the ratio MHPG/NE and by the decrease in the NE content after treatment with alpha-methylparatyrosine was faster in the MVN (half-life: 1.5h) than in LC (half-life: 3.6h). On the other hand, the ratio 5-HIAA/5-HT was lower in the MVN (0.58) than in the RD (0.85) indicating a smaller 5-HT turnover in the MVN. In addition, like LC and RD, the MVN contained meaningful amounts of dopamine (DA) and DOPAC. The high ratio DA/NE (0.27) suggests the presence of non precursor specific dopaminergic pools. However, individualized dopaminergic neurons have not yet been demonstrated. The data are discussed in line with the possible neurotransmitter function of monoamines in the MVN. PMID:9617784

Cransac, H; Cottet-Emard, J M; Pequignot, J M; Peyrin, L

1996-01-01

237

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

238

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 | Language: 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

239

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 | Language: 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

240

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

Directory of Open Access Journals (Sweden)

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

Juliane Tuma

2005-10-01

 
 
 
 
241

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

242

Facial Nerve Outcome after Vestibular Schwannoma Surgery: Our Experience*  

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In this study we evaluate the postoperative facial nerve function after vestibular schwannoma (VS) surgery and analyze the factors that cause it. We included 97 consecutive patients undergoing surgical excision of sporadic unilateral VS. Patient and tumor characteristics, surgical approaches, facial nerve function, extent of tumor removal, perioperative complications are all analyzed through standardized systems. Four different surgical approaches are used: translabyrinthine, retrolabyrinthin...

Rinaldi, Vittorio; Casale, Manuele; Bressi, Federica; Potena, Massimiliano; Vesperini, Emanuela; Franco, Antonio; Silvestri, Sergio; Zini, Carlo; Salvinelli, Fabrizio

2012-01-01

243

Vertical torque responses to vestibular stimulation in standing humans.  

Science.gov (United States)

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

Reynolds, Raymond F

2011-08-15

244

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

245

La estimación visual de lo que está vertical en alteraciones vestibulares / The subjective visual vertical in vestibular disease  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish Objetivo. Identificar y comparar la precisión de la estimación visual de lo que está vertical, con y sin inclinación tronco-cefálica en el plano frontal (30°), en pacientes con enfermedad vestibular periférica o central. Métodos. Participaron 38 pacientes con enfermedad vestibular, periférica en 23 [...] y central en 15, además de 40 sujetos sin enfermedad vestibular. Se les instruyó a colocar en posición vertical una barra motorizada de 20 cm, manipulada por control remoto, mientras se encontraban sentados a 30 cm de una pantalla, sin guías visuales. Después de 10 determinaciones con el tronco y la cabeza erguidos y 10 determinación con inclinación tronco-cefálica de 30° a cada lado, se calculó el promedio del error de las estimaciones efectuadas en cada postura. Resultados. En sujetos sin enfermedad vestibular el error de la estimación en cualquier posición fue siempre menor a 2°. En posición erguida, el mayor error en la estimación se observó en pacientes con enfermedad periférica con nistagmus espontáneo. En todos los pacientes el error aumentó significativamente con inclinación tronco-cefálica (ANOVA, p Abstract in english Objective. To assess and compare the accuracy to perceive visual verticality, with and without trunk-head tilt in the frontal plane (30°), in patients with peripheral or central vestibular disease. Methods. Thirty eight patients accepted to participate, 23 with peripheral disease and 15 with central [...] disease. We also evaluated 40 healthy subjects. Subjects were seated facing a screen with an anchored motorized bar (20 cm). They were asked to bring the line to vertical, using a joystick, 10 times while seated upright and 10 times while tilted 30° to each side. An average of the distance from true vertical was calculated to determine the tilt of the visual vertical on each posture. Results. Always, estimations made by healthy subjects were

Catalina, Aranda-Moreno; Kathrine, Jáuregui -Renaud.

2005-02-01

246

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

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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

247

Galvanic vestibular stimulator for fMRI studies  

Scientific Electronic Library Online (English)

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

248

Effects of vestibular and balance rehabilitation on sensory organization and dizziness handicap.  

Science.gov (United States)

This retrospective study was undertaken to assess balance recovery and dizziness handicap in 32 patients after a vestibular and balance rehabilitation program. Outcomes were compared between 12 patients with peripheral vestibular disorders and 20 patients with central or mixed balance disorders. The patients were tested with posturography (sensory organization test [SOT]) and the Dizziness Handicap Inventory (DHI) before and after their therapy program. The vestibular SOT, composite SOT, and functional DHI scores obtained before and after exercise were significantly improved in both the peripheral and central groups. The visual SOT mean scores obtained before and after therapy were significantly different only for the group with central or mixed vestibular disorders. Changes in SOT scores were not directly correlated with changes in DHI scores. Outcome measures of vestibular rehabilitation protocols confirmed objective and subjective improvement of balance and dizziness handicap in patients with peripheral and central vestibular disorders. PMID:15697162

Badke, Mary Beth; Miedaner, James A; Shea, Terry A; Grove, Colin R; Pyle, G Mark

2005-01-01

249

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

250

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

DEFF Research Database (Denmark)

I begin by contrasting a taxonomic approach to the vestibular system with the structural approach I take in the bulk of this commentary. I provide an analysis of perspectival structure. Employing that analysis and following the structural approach, I propose three lines of empirical investigation to selectively manipulate and measure vestibular processing and perspectival structure. The hope is that this serves to indicate how interdisciplinary research on vestibular processing might advance our understanding of the structural features of conscious experience.

Alsmith, Adrian John Tetteh

2015-01-01

251

Responses of Pigeon Vestibular Hair Cells to Cholinergic Agonists and Antagonists  

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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.

2011-01-01

252

Vestibular Evoked Myogenic Potential in Congenitally Blind Patients Versus Normal Subjects  

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Background and Aim: Conventional balance tests such as electronystagmography and videonystagmography, which are vision-dependant, are not practical in blind patients. Instead, vestibular evoked myogenic potential , not needing any vision, seems to be a more appropriate test for evaluating the vestibular system, in these patients. This study aimed to assess the prevalence and the latencies of p13 and n23 waves among congenitally blind and sighted participants evaluated by vestibular evoked myo...

Sahar Shomeil Shushtary; Mansoureh Adel Ghahraman; Mahin Sedaie; Saeed Talebian; Shohreh Jalaie; Mojtaba Tavakoli

2011-01-01

253

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

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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

254

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

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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

255

Vestibular stimulation on a motion-simulator impacts on mood States  

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

LottaWinter; JeanLaurens; HaraldEngler; Axelwollmer, M.

2012-01-01

256

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

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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.

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

2012-01-01

257

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

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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

258

Interaction of brain areas of visual and vestibular simultaneous activity with fMRI.  

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Static body equilibrium is an essential requisite for human daily life. It is known that visual and vestibular systems must work together to support equilibrium. However, the relationship between these two systems is not fully understood. In this work, we present the results of a study which identify the interaction of brain areas that are involved with concurrent visual and vestibular inputs. The visual and the vestibular systems were individually and simultaneously stimulated, using flickering checkerboard (without movement stimulus) and galvanic current, during experiments of functional magnetic resonance imaging. Twenty-four right-handed and non-symptomatic subjects participated in this study. Single visual stimulation shows positive blood-oxygen-level-dependent (BOLD) responses (PBR) in the primary and associative visual cortices. Single vestibular stimulation shows PBR in the parieto-insular vestibular cortex, inferior parietal lobe, superior temporal gyrus, precentral gyrus and lobules V and VI of the cerebellar hemisphere. Simultaneous stimulation shows PBR in the middle and inferior frontal gyri and in the precentral gyrus. Vestibular- and somatosensory-related areas show negative BOLD responses (NBR) during simultaneous stimulation. NBR areas were also observed in the calcarine gyrus, lingual gyrus, cuneus and precuneus during simultaneous and single visual stimulations. For static visual and galvanic vestibular simultaneous stimulation, the reciprocal inhibitory visual-vestibular interaction pattern is observed in our results. The experimental results revealed interactions in frontal areas during concurrent visual-vestibular stimuli, which are affected by intermodal association areas in occipital, parietal, and temporal lobes. PMID:25300959

Della-Justina, Hellen M; Gamba, Humberto R; Lukasova, Katerina; Nucci-da-Silva, Mariana P; Winkler, Anderson M; Amaro, Edson

2015-01-01

259

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

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

Jocelyne Ventre-Dominey

2014-07-01

260

Sound-induced laryngeal and respiratory reflexes originate from vestibular afferents.  

Science.gov (United States)

To determine whether the auditory or vestibular system causes the sound-induced laryngeal reflex, which has been considered to participate in the auditory feedback control of vocalization, click-induced laryngeal responses were compared before and after sectioning of the cochlear and/or vestibular nerves in cats. The sound-induced reflex modulation of respiratory muscle activity was also investigated, because respiratory movement is important for vocal control. Sectioning of the cochlear nerves had little influence on these responses. In contrast, sectioning of the vestibular nerves abolished these responses. It was concluded that the sound-induced laryngeal and respiratory reflexes are attributed to the vestibular system. PMID:10683859

Kobayashi, N; Shiba, K; Nakazawa, K; Satoh, I; Nakajima, Y; Konno, A

2000-01-17

 
 
 
 
261

LEITURA DE IMAGENS: A ANÁLISE DE UMA PROVA DE VESTIBULAR  

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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

262

A model describing vestibular detection of body sway motion.  

Science.gov (United States)

An experimental technique was developed which facilitated the formulation of a quantitative model describing vestibular detection of body sway motion in a postural response mode. All cues, except vestibular ones, which gave a subject an indication that he was beginning to sway, were eliminated using a specially designed two-degree-of-freedom platform; body sway was then induced and resulting compensatory responses at the ankle joints measured. Hybrid simulation compared the experimental results with models of the semicircular canals and utricular otolith receptors. Dynamic characteristics of the resulting canal model compared closely with characteristics of models which describe eye movement and subjective responses to body rotational motions. The average threshold level, in the postural response mode, however, was considerably lower. Analysis indicated that the otoliths probably play no role in the initial detection of body sway motion.

Nashner, L. M.

1971-01-01

263

Pharmacotherapy of vestibular and ocular motor disorders, including nystagmus  

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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

264

Change in Hearing and Tinnitus in Conservatively Managed Vestibular Schwannomas  

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Objectives: The aim of this study was to evaluate the change of hearing and tinnitus in a group of conservatively managed unilateral vestibular schwannomas (VS). Design: Retrospective case series review. Setting: Tertiary referral otoneurological and skull base surgery department. Participants: Seventy patients affected by unilateral VS with at least two audiograms available were retrospectively evaluated. Main outcome measures: Changes in pure tone average (PTA), speech discrimination score ...

Quaranta, Nicola; Baguley, David M.; Moffat, David A.

2007-01-01

265

JNK signaling in neomycin-induced vestibular hair cell death  

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Mechanosensory hair cells are susceptible to apoptotic death in response to exposure to ototoxic drugs, including aminoglycoside antibiotics. The c-Jun n-terminal kinase (JNK) is a stress-activated protein kinase that can promote apoptotic cell death in a variety of systems. Inhibition of the JNK signaling pathway can prevent aminoglycoside-induced death of cochlear and vestibular sensory hair cells. We used an in vitro preparation of utricles from adult mice to examine the role of JNK activa...

Sugahara, Kazuma; Rubel, Edwin W.; Cunningham, Lisa L.

2006-01-01

266

Is surgical vestibular ablation necessary in disabling peripheral vertigo?  

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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

267

Fundus Obliteration and Facial Nerve Outcome in Vestibular Schwannoma Surgery  

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The major objectives in vestibular schwannoma (VS) surgery have evolved from reducing mortality to functional preservation of the facial nerve and hearing. Absence of fluid between the lateral end of the VS and the internal auditory canal fundus on magnetic resonance imaging (MRI) appeared to have a negative influence on hearing outcome. Our goal was to study the prognostic significance of fundus obliteration on facial nerve function after VS surgery in patients with clinically normal facial ...

Rompaey, Vincent; Dinther, Joost; Zarowski, Andrzej; Offeciers, Erwin; Somers, Thomas

2011-01-01

268

Norman Thagard Discusses Value of Microgravity Vestibular Investigation  

Science.gov (United States)

Onboard the International Microgravity Laboratory (IML) mission in July 1992, payload specialist Norman Thagard describes his role in the Microgravity Vestibular Investigation (MVI) which examined the effects of orbital flight on the human orientation system to obtain a better understanding of the mechanisms of adaptation to orbit. Due to gravity, researchers cannot separate the eyes detection of linear and angular motion. Crew members sat in the rotator chair on different axes and recorded eye movement while rotating.

1992-01-01

269

A model analysis of static stress in the vestibular membranes  

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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 str...

Pender Daniel J

2009-01-01

270

Vestibular evoked myogenic potential: we propose a new instrument  

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Introduction: Currently, there is still no specific instrument for assessment of vestibular evoked myogenic potentials, with the same performed by a device designed to capture auditory evoked potentials available in the market. Thus, the functions of amplification, filtering, stimulation, window capture, rejection of artifacts and features of averaging, as well as its management software, are much to be desired for the new role assigned to it. Objective: To compare latencies and amplitudes of...

Menezes, Pedro Lemos; Colafe?mina, Jose? Fernando; Oliveira, Aline Cabral

2010-01-01

271

Vascularized Mastoid Bone Flap Cranioplasty after Translabyrinthine Vestibular Schwannoma Surgery  

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Objective: We describe a novel technique of cranioplasty using a vascularized mastoid bone flap in patients after translabyrinthine excision of vestibular schwannomas (VS). Postoperative outcomes in terms of pinna and postauricular deformity are evaluated. Study Design: Retrospective study. Setting: Tertiary referral center. Results: Seventeen patients underwent cranioplasty with bone flap after translabyrinthine VS excision. At minimum follow-up of 12 months, none had a cerebrospinal fluid (...

Yuen, Heng-wai; Thompson, Andrew L.; Symons, Sean P.; Pirouzmand, Farhad; Chen, Joseph M.

2009-01-01

272

Radiosurgical treatment of sporadic vestibular schwannomas: A prospective cohort study  

International Nuclear Information System (INIS)

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

273

Purchase decision-making is modulated by vestibular stimulation  

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

Nora Preuss

2014-02-01

274

Vestibular schwannoma or tanycytic ependymoma: Immunohistologic staining reveals  

Science.gov (United States)

Background: The cerebellopontine angle (CPA) is a common location for primary tumors, most often vestibular schwannomas, and also meningiomas, dermoids, and a host of other neoplasms. Our case report illustrates how radiologic and histopathologic presentations of an unusual variant of ependymal neoplasm can be diagnostically challenging and how accurate diagnosis can affect treatment protocols. Case History: Our patient had a CPA mass that was a variant of ependymoma known as tanycytic ependymoma that mimicked vestibular schwannoma radiologically and during intraoperative pathologic examination. Diagnosis as a World Health Organization (WHO) grade II tanycytic ependymoma was supported by its appearance on evaluation of the permanent sections, its diffuse immunoreactivity for glial fibrillary acidic protein (GFAP), and the perinuclear dot-and-ring-like staining for epithelial membrane antigen (EMA). Conclusions: Our patient's CPA mass initially believed to be a vestibular schwannoma on preoperative evaluation, surgical appearance, and intraoperative pathologic consultation was then correctly diagnosed as a WHO grade II tanycytic ependymoma on permanent histologic sections with the assistance of immunohistochemical stains, including EMA. After this definitive diagnosis, our patient's adjuvant treatment was adjusted. Earlier diagnosis could have provided guidance for goals of resection and prompt initiation of adjuvant treatment. PMID:25506503

Divito, Anthony; Keller, Jeffrey T.; Hagen, Matthew; Zuccarello, Mario

2014-01-01

275

Regional differences in lectin binding patterns of vestibular hair cells  

Science.gov (United States)

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

276

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

277

Vestibular evoked myogenic potentials: past, present and future.  

Science.gov (United States)

Since the first description of sound-evoked short-latency myogenic reflexes recorded from neck muscles, vestibular evoked myogenic potentials (VEMPs) have become an important part of the neuro-otological test battery. VEMPs provide a means of assessing otolith function: stimulation of the vestibular system with air-conducted sound activates predominantly saccular afferents, while bone-conducted vibration activates a combination of saccular and utricular afferents. The conventional method for recording the VEMP involves measuring electromyographic (EMG) activity from surface electrodes placed over the tonically-activated sternocleidomastoid (SCM) muscles. The "cervical VEMP" (cVEMP) is thus a manifestation of the vestibulo-collic reflex. However, recent research has shown that VEMPs can also be recorded from the extraocular muscles using surface electrodes placed near the eyes. These "ocular VEMPs" (oVEMPs) are a manifestation of the vestibulo-ocular reflex. Here we describe the historical development and neurophysiological properties of the cVEMP and oVEMP and provide recommendations for recording both reflexes. While the cVEMP has documented diagnostic utility in many disorders affecting vestibular function, relatively little is known as yet about the clinical value of the oVEMP. We therefore outline the known cVEMP and oVEMP characteristics in common central and peripheral disorders encountered in neuro-otology clinics. PMID:20080441

Rosengren, S M; Welgampola, M S; Colebatch, J G

2010-05-01

278

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

Science.gov (United States)

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

279

[Interdisciplinary approach to vestibular system impairment].  

Science.gov (United States)

In the first part of this review the definition of vertigo/dizziness was discussed. The major difference between the two signs is the existence of the direction, which is specific for vertigo. Dizziness is a frequent complaint in the clinical practice. Its frequency is increasing with advance of age, to intimate the play of declining cognitive process in the pathogenesis of its. The popular health significance of vertigo is in the rowing number of the patients. The onset of the most cases with acute vertigo appears between secundums and minutes so the patients will be provided in circumstances of emergency department. First of all three form should be take into account: neuronitis vestibularis, benign paroxysmal positional vertigo and Meniere syndrome. Without typical periferal signs of vertigo, central cause should be searched, principally stroke (lysis possibility). The differential diagnose of the different dizziness/vertigo forms according to the elapsed time of the onset or congenital and acquired nystagmus was created in tables. The recommendations of the therapy of acute and chronic dizziness/vertigo syndromes are, lack of results of evidence based trials doubtful. The more often used drugs based on clinical trials are discussed as vinpocetine, betahistine and piracetam. The in vitro and in vivo data suggest that the last molecule is eligible to use both in periferal and central type of vertigo syndromes. PMID:21545007

Pongrácz, Endre

2011-03-30

280

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?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

 
 
 
 
281

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

Science.gov (United States)

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

282

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

283

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 | Language: 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

284

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

285

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

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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

286

Human vestibular cortex as identified with caloric stimulation in functional magnetic resonance imaging.  

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Anatomic and electrophysiological studies in monkeys have yielded a detailed map of cortex areas receiving vestibular afferents. In contrast, comparatively little is known about the cortical representation of the human vestibular system. In this study we applied caloric stimulation and fMRI to further characterize human cortical vestibular areas and to test for hemispheric dominance of vestibular information processing. For caloric vestibular stimulation we used cold nitrogen to avoid susceptibility artifacts induced by water calorics. Right and left side vestibular stimulation was repetitively performed inducing a nystagmus for at least 90 s after the end of the stimulation in all subjects. Only the first 60 s of this nystagmus period was included for statistical analysis and compared with the baseline condition. Activation maps revealed a cortical network with right hemispheric dominance, which in all subjects comprised the temporoparietal junction extending into the posterior insula and, furthermore, the anterior insula, pre- and postcentral gyrus, areas in the parietal lobe, the ventrolateral portion of the occipital lobe, and the inferior frontal gyrus extending into the inferior part of the precentral sulcus. In conclusion, caloric stimulation in fMRI reveals a widespread cortical network involved in vestibular signal processing corresponding to the findings from animal experiments and previous functional imaging studies in humans. Furthermore, this study demonstrates a strong right hemispheric dominance of vestibular cortex areas regardless of the stimulated side, consistent with the current view of a rightward asymmetrical cortical network for spatial orientation. PMID:12414278

Fasold, Oliver; von Brevern, Michael; Kuhberg, Marc; Ploner, Christoph J; Villringer, Arno; Lempert, Thomas; Wenzel, Rüdiger

2002-11-01

287

Vestibular Evoked Myogenic Potential in Congenitally Blind Patients Versus Normal Subjects  

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Full Text Available Background and Aim: Conventional balance tests such as electronystagmography and videonystagmography, which are vision-dependant, are not practical in blind patients. Instead, vestibular evoked myogenic potential , not needing any vision, seems to be a more appropriate test for evaluating the vestibular system, in these patients. This study aimed to assess the prevalence and the latencies of p13 and n23 waves among congenitally blind and sighted participants evaluated by vestibular evoked myogenic potential.Methods: In a cross-sectional study, vestibular evoked myogenic potential was recorded for 20 sighted and 20 congenitally blind subjects, aged 18 to 30 years old, using 500 Hz-tone bursts (95 dBnHL.Results: Vestibular evoked myogenic potentials responses were present in all (100% of the participants. Considering the results of the both ears, there was no significant difference between mean p13 and n23 latencies of the two groups (p>0.05.Conclusion: Formation of vestibular evoked myogenic potentials reflex arc and neural pathway in congenitally blind patients is similar to sighted individuals; hence, the development of this pathway is independent of the visual system. Vestibular evoked myogenic potentials test is a useful test to assess vestibular function of the blinds.

Sahar Shomeil Shushtary

2011-06-01

288

Concurrent Vestibular Schwannoma and Meningioma Mimicking a Single Cerebellopontine Angle Tumor  

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

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

2009-01-01

289

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

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Vestibular neuritis is defined as a sudden unilateral partial failure of the vestibular nerve that impairs the forwarding of vestibular information from the labyrinth. The patient suffers from vertigo, horizontal nystagmus and postural instability with a tendency toward ipsilesional falls. Although vestibular neuritis is a common disease, the central mechanisms to compensate for the loss of precise vestibular information remain poorly understood. It was hypothesized that symptoms following acute vestibular neuritis originate from difficulties in the processing of diverging sensory information between the responsible brain networks. Accordingly an altered resting activity was shown in multiple brain areas of the task-positive network. Because of the known balance between the task-positive and task-negative networks (default mode network; DMN) we hypothesize that also the DMN is involved. 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. PMID:25379422

Klingner, Carsten M; Volk, Gerd F; Brodoehl, Stefan; Witte, Otto W; Guntinas-Lichius, Orlando

2014-01-01

290

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

Scientific Electronic Library Online (English)

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

291

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  

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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 potenciais 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...

Súnia Ribeiro; Almeida, Roberta R.; Caovilla, Heloisa H.; Gananc?a, Mauri?cio M.

2005-01-01

292

Enlarged vestibular aqueduct (EVA) related with recurrent benign paroxysmal positional vertigo (BPPV).  

Science.gov (United States)

The vestibular aqueduct is a bony canal related to the bony labyrinth of the inner ear and represents the non-sensory components of the endolymph-filled, closed, membranous labyrinth. The association of congenital sensorineural hearing loss with a large or enlarged vestibular aqueduct is well known as the large vestibular aqueduct syndrome (LVAS). The enlarged VA (EVA) comprises abnormalities not only in the structure of the inner ear, but also in the physiology of the auditory and vestibular systems. The clinical picture of this clinical entity is variable [Yetiser S, Kertment M, Ozkaptan Y. Vestibular disturbance in patients with Large Vestibular Aqueduct Syndrome (LVAS). Acta Otolaryngol (StochK) 1999;119: 641-646]. Signs and symptoms of the auditory impairment are more commonly described in the literature: hearing loss ranges from mild to profound, arising from fluctuating to stepwise progressive or sudden. Vestibular disturbances, ranging from mild imbalance to episodic vertigo, are rarely described in the literature. Benign paroxysmal positional vertigo (BPPV) is a labyrinthine disorder with a typical behavior: intense crises of rotational vertigo induced by postural changes of the head, with short duration and usually good responsiveness to rehabilitative maneuvers. These maneuvers are effective in about 80% of patients with BPPV. BPPV often recurs. About 1/3 of patients have a recurrence in the first year after treatment, and by five years, about half of all patients have a recurrence. Vestibular aqueduct has been demonstrated by conventional tomography and computed tomography (CT), however, CT scans cannot show the membranous labyrinth itself. On MR images it is not the vestibular aqueduct that is visualized but its contents, the endolymphatic duct and sac, and can show the abnormalities of the fluid spaces related to the membranous labyrinth. It is proposed that recurrent benign paroxysmal positional vertigo (BPPV) is related with volumetric abnormalities of vestibular aqueduct. This verifiable hypothesis tries to define this rapport and explore new diagnostic and therapeutic possibilities. PMID:17590526

Manzari, Leonardo

2008-01-01

293

Multiple sclerosis as a cause of the acute vestibular syndrome.  

Science.gov (United States)

Multiple sclerosis (MS) causes dizziness and vertigo. Reports suggest responsible lesions are often in the intra-pontine 8th nerve fascicle. We sought to determine frequency and clinical features of demyelinating acute vestibular syndrome (AVS). This is a prospective observational study (1999-2011). Consecutive AVS patients (vertigo, nystagmus, nausea/vomiting, head-motion intolerance, unsteady gait) with a risk for central localization underwent structured bedside examination and neuroimaging. When applicable, we identified MS based on clinical, imaging, and laboratory features. Of 170 AVS presentations, 4% (n = 7) were due to demyelinating disease. Five had an acute MS plaque likely responsible for the clinical syndrome. Lesion location varied-1 medulla; 1 inferior cerebellar peduncle; 1 middle cerebellar peduncle; 1 posterior pontine tegmentum; 1 in the intrapontine 8th nerve fascicle; 1 superior cerebellar peduncle; 1 midbrain. Only two had a lesion in or near the intra-pontine 8th nerve fascicle. Three were first presentations (i.e., clinically isolated demyelinating syndrome), while the others were known MS. All had central oculomotor signs. In two patients, the only central sign was a normal horizontal head impulse test (h-HIT) of vestibular function. All patients improved with steroid therapy. Demyelinating disease was an uncommon cause of AVS in our series. Symptomatic lesions were not restricted to the 8th nerve fascicle. Five patients had relatively obvious oculomotor signs, making differentiation from vestibular neuritis straightforward. Two patients had unidirectional, horizontal nystagmus that followed Alexander's law and was suppressed with fixation (true pseudoneuritis). The presence of a normal h-HIT in these suggested central localization. PMID:23392781

Pula, J H; Newman-Toker, D E; Kattah, J C

2013-06-01

294

Cold shivering activity after unilateral destruction of the vestibular apparatus  

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The bioelectric activity of muscles (flexors and extensors of the forelimbs and hindlimbs) during cold shivering after unilateral destruction of the vestibular apparatus. It was found, that unilateral delabyrinthing produces bilateral facilitation of cold shivering in the flexor extremities more pronounced on the ipsilateral side. In the extensor muscles there was an absence of bioelectric activity both before and after delabyrinthing. Enhancement of cold shivering in the flexor extremities following intervention was evidently conditioned by removal of the inhibiting effect of the vestibulary apparatus on the function of special centers.

Kuzmina, G. I.

1980-01-01

295

[Variations of EGG in subjects under vestibular stimulation].  

Science.gov (United States)

Objective. To investigate the patterns of electrogastrogram [correction of electrogastrogragm] (EGG) before, during and after vestibular stimulation. Method. 25 subjects were stimulated by Coriolis acceleration and 28 by Coriolis [correction of corolis] stimulation. Result. Dysrythmia of EGG and increase of tachygastria were recorded in all subjects during the stimulation. The period dominant frequency (PDF) of EGG shifted from 2.40-3.70 cpm to 3.70-10.00 cpm during Coriolis stimulus in subjects with nausea. Conclusion. It suggests that PDF could be a parameter in reflecting the level of motion sickness. PMID:12430544

Liu, Z Q; Pei, J C; Sun, R L; Chang, L; Zhang, H

1999-04-01

296

Vestibular-related neuroscience and manned space flight  

Science.gov (United States)

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

Igarashi, Makoto

1988-01-01

297

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 SciELO Brazil | Language: Portuguese Abstract in portuguese 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

298

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

299

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

300

Dificuldades de compreensão de textos em situação de vestibular = Difficulties relates to text understanding in vestibular examination  

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Full Text Available Este trabalho é pautado na concepção de leitura como forma de interação sujeitos/texto/contexto e destina-se a discutir algumas perspectivas de leitura textual, bem como apresentar uma visão de alguns documentos oficiais e órgãos de pesquisa da educação. Na parte analítica, objetiva-se investigar uma questão da prova de Língua Portuguesa do vestibular de 2008 da Unicamp, articulando o comando da pergunta, a sugestão de resposta elaborada pela banca examinadora e seis respostas emitidas por candidatos. A fim de mapear as dificuldades de compreensão de alunos apresentadas nas respostas de uma questão envolvendo a leitura de um exemplar do gênero tirinha, a pesquisa pauta-se na no conceito de sistemas de conhecimentos da Linguística Textual: conhecimentos linguísticos, enciclopédicos e interacionais. A análise do corpus demonstra a relevância de uma leitura baseada na funcionalidade do gênero tirinha e no acionamento dos conhecimentos linguísticos, enciclopédicos e interacionais pressupostos não somente no texto da tira, mas também na textualidade do comando da questão do vestibular.This study is based on the concept of reading as a way of interaction among subjects/text/context. It aims at discussing some perspectives of textual reading as well as to present a view of some official documents and educational research institutions. In the analytical part, it aims at investigating one question from the Portuguese Test of 'Vestibular' from 2008 at Unicamp University, articulating the command of the question to the suggestion of answer elaborated by the examiners and six answers given by the candidates. In order to map the students difficulties of comprehension presented in the answersinvolving reading of an excerpt of Comic Strip genre, the research is based on the concept of knowledge systems of Textual Linguistics: linguistics knowledge, encyclopedic and interactional. Thus, the analysis demonstrates the relevance of reading based on functionality and in the actuation of the linguistics knowledge, encyclopedic andinteractional assumed not only in the comic strip excerpt, but also in the textuality of the command of vestibular questions.

Adair Vieira Gonçalves

2011-07-01

 
 
 
 
301

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

302

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

303

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

Scientific Electronic Library Online (English)

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

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

2011-04-01

304

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

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

Aline Tenório Lins Carnaúba

2011-04-01

305

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

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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

306

Can a fixed measure serve as a pertinent diagnostic criterion for large vestibular aqueduct in children?  

International Nuclear Information System (INIS)

A vestibular aqueduct midpoint width greater than 1.50 mm is currently considered to be pathognomonic for a large vestibular aqueduct syndrome. To analyse the diameter of the vestibular aqueduct in children as a function of age and consequently to determine if a fixed measure could serve as a pertinent diagnostic criterion. This was a retrospective study of 200 high-resolution CT scans of the ear in 100 patients aged 0-16 years and from various paediatric medical departments. On each CT scan, the lateral semicircular canal diameter, the vestibular aqueduct midpoint width between the external aperture and common crus, and the vestibular aqueduct external aperture diameter were measured. Spearman's rank test and the Mann-Whitney correlation test were used for an integrated statistical analysis. There was no statistically significant variability in vestibular aqueduct diameter as a function of age or sex of patients. A CT scan threshold value, fixed and independent of age and sex, is thus legitimate for the diagnosis of vestibular aqueduct dilatation. (orig.)

307

Can a fixed measure serve as a pertinent diagnostic criterion for large vestibular aqueduct in children?  

Energy Technology Data Exchange (ETDEWEB)

A vestibular aqueduct midpoint width greater than 1.50 mm is currently considered to be pathognomonic for a large vestibular aqueduct syndrome. To analyse the diameter of the vestibular aqueduct in children as a function of age and consequently to determine if a fixed measure could serve as a pertinent diagnostic criterion. This was a retrospective study of 200 high-resolution CT scans of the ear in 100 patients aged 0-16 years and from various paediatric medical departments. On each CT scan, the lateral semicircular canal diameter, the vestibular aqueduct midpoint width between the external aperture and common crus, and the vestibular aqueduct external aperture diameter were measured. Spearman's rank test and the Mann-Whitney correlation test were used for an integrated statistical analysis. There was no statistically significant variability in vestibular aqueduct diameter as a function of age or sex of patients. A CT scan threshold value, fixed and independent of age and sex, is thus legitimate for the diagnosis of vestibular aqueduct dilatation. (orig.)

Legeais, Marc; Cottier, Jean P. [CHU de TOURS, Department of Neuroradiology, Tours (France); Haguenoer, Ken [CHU de TOURS, Department of Medical Information, Tours (France); Sirinelli, Dominique [CHU de TOURS, Department of Paediatric Radiology, Tours (France)

2006-10-15

308

Vestibular activation differentially modulates human early visual cortex and V5/MT excitability and response entropy.  

Science.gov (United States)

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

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

2013-01-01

309

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.

310

Pathogenesis of vestibular schwannoma in ring chromosome 22  

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Full Text Available Abstract Background Ring chromosome 22 is a rare human constitutional cytogenetic abnormality. Clinical features of neurofibromatosis type 1 and 2 as well as different tumour types have been reported in patients with ring chromosome 22. The pathogenesis of these tumours is not always clear yet. Methods We report on a female patient with a ring chromosome 22 presenting with severe mental retardation, autistic behaviour, café-au-lait macules and facial dysmorphism. Peripheral blood lymphocytes were karyotyped and array CGH was performed on extracted DNA. At the age of 20 years she was diagnosed with a unilateral vestibular schwannoma. Tumour cells were analyzed by karyotyping, array CGH and NF2 mutation analysis. Results Karyotype on peripheral blood lymphocytes revealed a ring chromosome 22 in all analyzed cells. A 1 Mb array CGH experiment on peripheral blood DNA showed a deletion of 5 terminal clones on the long arm of chromosome 22. Genetic analysis of vestibular schwannoma tissue revealed loss of the ring chromosome 22 and a somatic second hit in the NF2 gene on the remaining chromosome 22. Conclusion We conclude that tumours can arise by the combination of loss of the ring chromosome and a pathogenic NF2 mutation on the remaining chromosome 22 in patients with ring chromosome 22. Our findings indicate that patients with a ring 22 should be monitored for NF2-related tumours starting in adolescence.

Debiec-Rychter Maria

2009-09-01

311

Large Vestibular Schwannomas Presenting during Pregnancy: Management Strategies.  

Science.gov (United States)

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

Shah, Kushal J; Chamoun, Roukoz B

2014-06-01

312

Early diagnosis of acoustic neuroma by the vestibular test  

International Nuclear Information System (INIS)

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

313

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

314

Vertigo and vestibular abnormalities in spinocerebellar ataxia type 6.  

Science.gov (United States)

Spinocerebellar ataxia type 6 (SCA6) is a calcium channelopathy due to a pathological CAG repeat expansion in CACNL1A4. Patients frequently describe paroxysmal vertigo early in the disease course, but it is not clear whether this is central or labyrinthine in origin. To address this issue we studied 21 SCA6 patients. Symptoms of vertigo were defined using a structured questionnaire. Signs were recorded during a standardised bed-side vestibular examination that included systematic positional testing with Frenzel goggles.Brief, recurrent attacks of vertigo occurred in 13 patients, usually preceding the onset of ataxia. Nystagmus was observed behind Frenzel goggles in 14 patients, and was induced either during positional testing, or head shaking in 20 patients. Only one patient had findings typical of benign paroxysmal positional vertigo (BPPV). Combined downbeat and horizontal gaze-evoked nystagmus ("side-pocket") was the most common form, occurring most commonly in supine and head-hanging positions, and following horizontal head-shaking. Nystagmus beating away from the ground (apogeotropic) occurred in 9 patients as they lay on their side.In conclusion, vertigo and abnormalities on bedside vestibular examination are common in SCA6, with forms of nystagmus typical of cerebellar, rather than labyrinthine, disease. These findings demonstrate phenotypic overlap between SCA6 and episodic ataxia type 2, which are both due to mutations in CACNL1A4. PMID:19224313

Yu-Wai-Man, Patrick; Gorman, Grainne; Bateman, David E; Leigh, R John; Chinnery, Patrick F

2009-01-01

315

Early diagnosis of acoustic neuroma by the vestibular test  

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

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

1981-11-01

316

Glutamate metabotropic receptor mediated depression of synaptic inputs to lamprey reticulospinal neurones.  

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The transmission of vestibular inputs to reticulospinal (RS) neurones of the posterior rhombencephalic nucleus (PRRN) has been shown to be depressed by the bath application of N-methyl-D-aspartate (NMDA). The aim of this study was to investigate the pharmacological mechanism involved using patch clamp recordings of reticulospinal neurones. It is demonstrated that the chemical component of vestibular inputs to the PRRN is mediated by glutamatergic synapses utilising alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl-D-aspartate (NMDA) receptors on the PRRN neurones. Monosynaptic excitatory postsynaptic currents (EPSCs) from octavomotorius relay cells to RS neurones are markedly depressed by the application of NMDA, a depression which was insensitive to competitive and non-competitive NMDA receptor antagonists. The effect of NMDA was eliminated by inactivation of G proteins. A similar depressive effect was observed following application of (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid (ACPD) to the superfusate. It is concluded that NMDA acts at a metabotropic receptor located most likely presynaptically to reticulospinal neurones on terminals of octavomotorius relay cells. PMID:8096788

Alford, S; Dubuc, R

1993-03-01

317

Isolated vestibular nuclear infarction: report of two cases and review of the literature.  

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Cerebral infarction presenting with isolated vertigo remains a diagnostic challenge. To define the clinical characteristics of unilateral infarctions restricted to the vestibular nuclei, two patients with isolated unilateral vestibular nuclear infarction had bedside and laboratory evaluation of the ocular motor and vestibular function, including video-oculography, bithermal caloric irrigation, the head impulse test (HIT) using magnetic scleral coils, and cervical and ocular vestibular-evoked myogenic potentials (VEMPs). We also reviewed the literature on isolated vertigo from lesions restricted to the vestibular nuclei, and analyzed the clinical features of seven additional patients. Both patients showed spontaneous torsional-horizontal nystagmus that beat away from the lesion side, and direction-changing gaze-evoked nystagmus. Recording of HIT using a magnetic search coil system documented decreased gains of the vestibular-ocular reflex for the horizontal and posterior semicircular canals on both sides, but more for the ipsilesional canals. Bithermal caloric tests showed ipsilesional canal paresis in both patients. Cervical and ocular VEMPs showed decreased or absent responses during stimulation of the ipsilesional ear. Initial MRIs including diffusion-weighted images were normal or equivocal, but follow-up imaging disclosed a circumscribed acute infarction in the area of the vestibular nuclei. Infarctions restricted to the vestibular nuclei may present with isolated vertigo with features of both peripheral and central vestibulopathies. Central signs should be sought even in patients with spontaneous horizontal-torsional nystagmus and positive HIT. In patients with combined peripheral and central vestibulopathy, a vestibular nuclear lesion should be considered especially when hearing is preserved. PMID:24162036

Kim, Hyo-Jung; Lee, Seung-Han; Park, Jae Han; Choi, Jung-Yoon; Kim, Ji-Soo

2014-01-01

318

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

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Astronauts experience disturbances in sensorimotor function after spaceflight during the initial introduction to a gravitational environment, especially after long-duration missions. Stochastic resonance (SR) is a mechanism by which noise can assist and enhance the response of neural systems to relevant, imperceptible sensory signals. We have previously shown that imperceptible electrical stimulation of the vestibular system enhances balance performance while standing on an unstable surface. The goal of our present study is to develop a countermeasure based on vestibular SR that could improve central interpretation of vestibular input and improve motor task responses to mitigate associated risks.

Mulavara, Ajitkumar; Fiedler, Matthew; DeDios,Yiri E.; Galvan, Raquel; Bloomberg, Jacob; Wood, Scott

2011-01-01

319

Frequency-specific modulation of vestibular-evoked sway responses in humans.  

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Galvanic vestibular stimulation (GVS) results in characteristic muscle and whole-body responses in humans maintaining standing balance. However, the relationship between these two vestibular-evoked responses remains elusive. This study seeks to determine whether mechanical filtering from conversion of lower-limb muscle activity to body sway, during standing balance, can be used to attenuate sway while maintaining biphasic lower-limb muscle responses using frequency-limited stochastic vestibular stimulation (SVS). We hypothesized that SVS deprived of frequencies 2 Hz to standing humans do not cause a destabilizing whole-body sway response but are associated with the typical biphasic lower-limb muscle responses. PMID:20032237

Dakin, Christopher J; Luu, Billy L; van den Doel, Kees; Inglis, John Timothy; Blouin, Jean-Sébastien

2010-02-01

320

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

 
 
 
 
321

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

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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

322

Transduction of murine cerebellar neurons with recombinant FIV and AAV5 vectors.  

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Our data demonstrate that vectors derived from recombinant feline immunodeficiency virus (rFIV) and adeno-associated virus type 5 (rAAV5) transduce cerebellar cells following direct injection into the cerebellar lobules of mice. Both recombinant viruses mediated gene transfer predominantly to neurons, with up to 2500 and 1500 Purkinje cells transduced for rAAV5 or rFIV-based vectors, respectively. The vectors also transduced stellate, basket and Golgi neurons, with occasional transduction of granule cells and deep cerebellar nuclei. rAAV5 also spread outside the cerebellum to the inferior colliculus and ventricular epithelium, while rFIV demonstrated the ability to undergo retrograde transport to the physically close lateral vestibular nuclei. Thus, AAV5 and FIV-based vectors show promise for targeting neurons affected in the hereditary spinocerebellar ataxias. These vectors could be important tools for unraveling the pathophysiology of these disorders, or in testing factors which may promote neuronal survival. PMID:10976941

Alisky, J M; Hughes, S M; Sauter, S L; Jolly, D; Dubensky, T W; Staber, P D; Chiorini, J A; Davidson, B L

2000-08-21

323

Adaptation of vestibular signals for self-motion perception.  

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A fundamental concern of the brain is to establish the spatial relationship between self and the world to allow purposeful action. Response adaptation to unvarying sensory stimuli is a common feature of neural processing, both peripherally and centrally. For the semicircular canals, peripheral adaptation of the canal-cupula system to constant angular-velocity stimuli dominates the picture and masks central adaptation. Here we ask whether galvanic vestibular stimulation circumvents peripheral adaptation and, if so, does it reveal central adaptive processes. Transmastoidal bipolar galvanic stimulation and platform rotation (20 deg s?1) were applied separately and held constant for 2 min while perceived rotation was measured by verbal report. During real rotation, the perception of turn decayed from the onset of constant velocity with a mean time constant of 15.8 s. During galvanic-evoked virtual rotation, the perception of rotation initially rose but then declined towards zero over a period of ?100 s. For both stimuli, oppositely directed perceptions of similar amplitude were reported when stimulation ceased indicating signal adaptation at some level. From these data the time constants of three independent processes were estimated: (i) the peripheral canal-cupula adaptation with time constant 7.3 s, (ii) the central ‘velocity-storage' process that extends the afferent signal with time constant 7.7 s, and (iii) a long-term adaptation with time constant 75.9 s. The first two agree with previous data based on constant-velocity stimuli. The third component decayed with the profile of a real constant angular acceleration stimulus, showing that the galvanic stimulus signal bypasses the peripheral transformation so that the brainstem sees the galvanic signal as angular acceleration. An adaptive process involving both peripheral and central processes is indicated. Signals evoked by most natural movements will decay peripherally before adaptation can exert an appreciable effect, making a specific vestibular behavioural role unlikely. This adaptation appears to be a general property of the internal coding of self-motion that receives information from multiple sensory sources and filters out the unvarying components regardless of their origin. In this instance of a pure vestibular sensation, it defines the afferent signal that represents the stationary or zero-rotation state. PMID:20937715

St George, Rebecca J; Day, Brian L; Fitzpatrick, Richard C

2011-02-15

324

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

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

Black, F. Owen

2002-01-01

325

A model analysis of tensile stress in the toadfish vestibular membranes.  

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Background. A theoretical model analysis of stress in the vestibular membranes has identified a geometrical stress factor incorporating shape, size, and thickness that can be used to assess peak stress in the various chambers. Methods. Using published measurements of the toadfish vestibular membranes made during surgery, the geometrical stress factor can be evaluated for each chamber based on the model. Results. The mean geometrical stress factor is calculated to be the lowest in the semicircular canal (4.4), intermediate in the ampulla (6.0), and the highest in the utricle (17.4). Conclusions. The model predicts that substantial hoop stress disparities exist in the toadfish vestibular labyrinth. Stress is least in the semicircular canal, which therefore appears to be the structure with greatest stability. The utricle is found to be the most stress prone structure in the vestibular labyrinth and therefore appears to be the chamber most vulnerable to distention and potential modification. PMID:21716692

Pender, Daniel J

2011-01-01

326

[An update on the treatment of vestibular schwannoma].  

Science.gov (United States)

The increase in the diagnosis of ever smaller vestibular schwannomas (VS), the fact that many tumours can be observed with serial MRI, and the development of radiosurgery as an alternative to microsurgery have led the neurotologic surgeon to a new global approach to patients with VS. On the other hand, the spread of internet-based information sources, often with biased or incomplete information, makes counselling patients with VS a challenging task. This study provides an overview of the natural history of these tumours and the main therapeutic options: observation, surgery and radiosurgery, with comments on their indications, advantages and disadvantages. Due to the completely different approach and peculiar features of bilateral VS in patients with type II neurofibromatosis, these are excluded. PMID:19401081

Lassaletta, Luis; Gavilán, Javier

2009-01-01

327

Calcification of vestibular schwannoma: a case report and literature review  

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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

328

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

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

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

2005-01-01

329

Effects of Vestibular Prosthesis Electrode Implantation and Stimulation on Hearing in Rhesus Monkeys  

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To investigate the effects of vestibular prosthesis electrode implantation and activation on hearing in rhesus monkeys, we measured auditory brainstem responses (ABR) and distortion product otoacoustic emissions (DPOAE) in four rhesus monkeys before and after unilateral implantation of vestibular prosthesis electrodes in each of 3 left semicircular canals (SCC). Each of the 3 left SCCs were implanted with electrodes via a transmastoid approach. Right ears, which served as controls, were not s...

Dai, Chenkai; Fridman, Gene Y.; Della Santina, Charles C.

2011-01-01

330

Vestibular evoked myogenic potentials in multiple sclerosis: clinical and imaging correlations  

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Patients with multiple sclerosis (MS) frequently report symptoms related to vestibular disorders in the course of their disease. At present, the fundamental tests assessing vestibulospinal involvement are posturography and vestibular evoked myogenic potentials (VEMPs). While posturography cannot be performed in every subject requiring minimal stance control, VEMPs do not require any specific skill on the part of the subjects and they may be investigated in all patients able to sit. VEMPs were...

Alpini, Dario; Pugnetti, Luigi; Caputo, Domenico; Cornelio, Ferdinando; Capobianco, Francesco Saverio; Cesarani, Antonio

2004-01-01

331

Temporal dynamics of semicircular canal and otolith function following acute unilateral vestibular deafferentation in humans  

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Dynamic changes of deficits in canal and otolith vestibulo-ocular reflexes (VORs) to high acceleration, eccentric yaw rotations were investigated in five subjects aged 25–65 years before and at frequent intervals 3–451 days following unilateral vestibular deafferentation (UVD) due to labyrinthectomy or vestibular neurectomy. Eye and head movements were recorded using magnetic search coils during transients of directionally random, whole-body rotation in darkness at peak acceleration 2,800...

Tian, Jun-ru; Ishiyama, Akira; Demer, Joseph L.

2006-01-01

332

Visuo-spatial memory enhancement by galvanic vestibular stimulation: A preliminary report  

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Full Text Available Background and Aim: Navigation information is processed and stored in different brain areas such as hippocampus. Since multiple pathways has been reported between vestibular nuclei and hippocampus and also cognitive dysfunction specifically in spatial memory is induced by vestibular deficits, it can be assumed that vestibular system stimulation ameliorates spatial memory. The aim of study was to evaluate the effect of galvanic vestibular stimulation on normal individual’s spatial memory.Methods: In this experimental-interventional study, sixty 18-30-years-old women were randomly allocated in intervention and control groups. Intervention group undergone subthreshold bilateral bipolar galvanic vestibular stimulation and control group received sham stimulation. Stimulation was presented for 15 minutes. Corsi Block Tapping (CBT test scores were compared before and after subthreshold bipolar galvanic vestibular stimulation exposure or no stimulation in each group and between groups.Results: All test parameters were the same in both groups before stimulation (p<0.050. There were significant improvement in block span, total score and learning score in intervention group after galvanic vestibular stimulation (p<0.050, no significant difference in delayed score (p=0.600. Learning score was improved (p=0.003 and delayed score was deteriorated (p=0.010 in control group. Percentages of block span and total score in intervention group were significantly different compared to the other group (p<0.050.Conclusion: Galvanic vestibular stimulation improves short-term and long-term spatial memory. This test may inherently have learning effect that is not influenced by stimulation.

Fatemehsadat Ghaheri

2014-04-01

333

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

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Physiological responses to changes in the gravitational field and body position, as well as symptoms of patients with anxiety-related disorders, have indicated an interrelationship between vestibular function and stress responses. However, the relative significance of cochlear and vestibular information in autonomic regulation remains unresolved because of the difficulties in distinguishing the relative contributions of other proprioceptive and interoceptive inputs, including vagal and somati...

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

2002-01-01

334

Clinical and Histologic Parameters Correlated with Facial Nerve Function After Vestibular Schwannoma Surgery  

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This study was conducted to identify clinical and histologic factors that would influence, independently of tumor staging, postoperative facial function after removal of a vestibular schwannoma. A prospective study was performed on 35 consecutive patients with vestibular schwannomas who underwent the translabyrinthine approach. Facial function was assessed before and 1 year after surgery. The factors that influenced the postoperative outcome of the facial function independently of tumor stagi...

Couloigner, Vincent; Gervaz, Elena; Kalamarides, Michel; Ferrary, Evelyne; Rey, Alain; Sterkers, Olivier; He?nin, Dominique

2003-01-01

335

Gentamicin is Primarily Localized in Vestibular Type I Hair Cells after Intratympanic Administration  

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Intratympanic (IT) gentamicin injections are effective in the control of episodic vertigo due to Ménière’s disease. Histological studies in animals have found that the loss of type I vestibular hair cells far exceeds that of type II cells after IT gentamicin treatment. The objective of this study was to determine whether this selective toxicity for type I hair cells might be due to selective concentration of the drug by these cells. Gentamicin was localized within the vestibular epitheliu...

Lyford-pike, Sofia; Vogelheim, Casey; Chu, Eugene; Della Santina, Charles C.; Carey, John P.

2007-01-01

336

A Model Analysis of Tensile Stress in the Toadfish Vestibular Membranes  

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Background. A theoretical model analysis of stress in the vestibular membranes has identified a geometrical stress factor incorporating shape, size, and thickness that can be used to assess peak stress in the various chambers. Methods. Using published measurements of the toadfish vestibular membranes made during surgery, the geometrical stress factor can be evaluated for each chamber based on the model. Results. The mean geometrical stress factor is calculated to be the lowest in the semicirc...

Pender, Daniel J.

2011-01-01

337

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

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

Lystad Reidar P

2011-09-01

338

Vestibular evoked myogenic potentials in patients with inactive stage of systemic lupus erythematosus  

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Full Text Available Background and Aim: Patients with systemic lupus erythematosus (SLE may develop hearing and balance disorders as a result of the immune-mediated inner ear damage. Vestibular evoked myogenic potential (VEMP is a new vestibular test assesses the vestibulospinal tract. Balance disorders such as endolymphatic hydrops may occur as a result of perisaccular deposition of immune complexes in these patients. Although the vestibular system abnormality in the patients has been demonstrated, the function of the part of vestibular system including vestibulospinal tract has not been investigated so far. This study aimed to compare the vestibular evoked myogenic potentials between patients with inactive stage of systemic lupus erythematosus and normal individuals. Methods: In this cross-sectional study, vestibular evoked myogenic potential was recorded between 26 healthy subjects and 20 patients with lupus erythematosus in inactive stage of disease aged 20 to 50 years old, using 500 Hz-tone bursts at 95 dB nHL. Results: Vestibular evoked myogenic potentials responses were present in all (100% of the participants. There was no significant difference in mean peak to peak amplitude and assymetry ratio between two groups. The mean p13 and n23 latencies were significantly higher in patients (p<0.05. Duration of disease had no effect on test parameters. Conclusion: According to the prolonged latency of vestibular evoked myogenic potentials response in patients with lupus erythematosus , lesions in the retrolabyrinthine, especially in the vestibulospinal tract is suspected. Due to small sample size, there is no possibility for generalizing this result to all patients with lupus lupus erythematosus .

Roghayeh Farhadi

2013-05-01

339

Menstrual cycle elicits divergent forearm vascular responses to vestibular activation in humans  

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The menstrual cycle has been reported to alter mean arterial pressure (MAP), but not muscle sympathetic nerve activity (MSNA), during vestibular activation. Specifically, MAP responses to head-down rotation (HDR) are augmented during the midluteal (ML) phase compared to the early follicular (EF) phase in young, eumenorrheic women. The purpose of the present study was to determine if the menstrual cycle influences vestibular-mediated changes in limb blood flow. MSNA, MAP, heart rate, and limb ...

Lawrence, Johnathan E.; Klein, Jenna C.; Carter, Jason R.

2009-01-01

340

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

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

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

2010-01-01

 
 
 
 
341

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.

342

Endoscope-controlled removal of intrameatal vestibular schwannomas.  

Science.gov (United States)

The use of endoscopes for surgery of the cerebellopontine angle tumors is steadily obtaining widespread acceptance. The objective of the present study was a laboratory and clinical evaluation of the safety of the endoscope-controlled microneurosurgical removal of the intrameatal vestibular schwannomas through a retrosigmoid approach. The anatomical investigation was done on formalin-fixed cadaver heads and dry temporal bones. Clinical series included 33 consecutive patients (23 women and 10 men; mean age 50 +/- 15 years). A bayonet-style rigid endoscope with 70 degrees angle of view and 4 mm outer diameter was found to be optimal for observation of the internal auditory canal. Its insertion in the cerebellopontine cistern should be preferably done under control through an operating microscope. Endoscope-controlled manipulations necessitate the use of a special holder system, which provides a stable position of the device and allows bimanual manipulations by the surgeon. A thermographic evaluation did not reveal a significant increase of the local temperature due to use of the endoscope. Use of the endoscope permitted removal of the neoplasm from the most lateral part of the internal auditory canal and identification of the nerve of tumor origin. In total, 28 tumors underwent total removal, and anatomical preservation of the facial nerve was attained in 31 cases. Damage of the facial nerve by the endoscope was met once. In 8 out of 16 patients, who showed serviceable hearing before surgery, this was preserved after tumor removal. In conclusion, endoscope-controlled removal of the intrameatal vestibular schwannomas seems to be a technically feasible, effective and safe procedure. Nevertheless, good equipment and special training are absolutely necessary for attainment of optimal results. PMID:16547878

Hori, T; Okada, Y; Maruyama, T; Chernov, M; Attia, W

2006-02-01

343

Directional abnormalities of vestibular and optokinetic responses in cerebellar disease  

Science.gov (United States)

Directional abnormalities of vestibular and optokinetic responses in patients with cerebellar degeneration are reported. Three-axis magnetic search-coil recordings of the eye and head were performed in eight cerebellar patients. Among these patients, examples of directional cross-coupling were found during (1) high-frequency, high-acceleration head thrusts; (2) constant-velocity chair rotations with the head fixed; (3) constant-velocity optokinetic stimulation; and (4) following repetitive head shaking. Cross-coupling during horizontal head thrusts consisted of an inappropriate upward eye-velocity component. In some patients, sustained constant-velocity yaw-axis chair rotations produced a mixed horizontal-torsional nystagmus and/or an increase in the baseline vertical slow-phase velocity. Following horizontal head shaking, some patients showed an increase in the slow-phase velocity of their downbeat nystagmus. These various forms of cross-coupling did not necessarily occur to the same degree in a given patient; this suggests that different mechanisms may be responsible. It is suggested that cross-coupling during head thrusts may reflect a loss of calibration of brainstem connections involved in the direct vestibular pathways, perhaps due to dysfunction of the flocculus. Cross-coupling during constant-velocity rotations and following head shaking may result from a misorientation of the angular eye-velocity vector in the velocity-storage system. Finally, responses to horizontal optokinetic stimulation included an inappropriate torsional component in some patients. This suggests that the underlying organization of horizontal optokinetic tracking is in labyrinthine coordinates. The findings are also consistent with prior animal-lesion studies that have shown a role for the vestibulocerebellum in the control of the direction of the VOR.

Walker, M. F.; Zee, D. S.; Shelhamer, M. J. (Principal Investigator)

1999-01-01

344

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

345

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

Science.gov (United States)

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

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

1996-12-01

346

Vestibular impairment in Charcot-Marie-Tooth disease type 4C.  

Science.gov (United States)

Charcot-Marie-Tooth disease type 4C (CMT4C) is a hereditary neuropathy with prominent unsteadiness. The objective of the current study is to determine whether the imbalance in CMT4C is caused only by reduced proprioceptive input or if vestibular nerve involvement is an additional factor. We selected 10 CMT4C patients and 10 age-matched and sex-matched controls. We performed a comprehensive evaluation of the vestibular system, including video Head Impulse Test, bithermal caloric test, galvanic stimulation test and skull vibration-induced nystagmus test. None of the patients experienced dizziness, spontaneous or gaze-evoked nystagmus, but all had significant vestibular impairment when tested when compared to controls. Seven had completely unexcitable vestibular systems and abnormal vestibuloocular reflex. There was no correlation between the degree of vestibulopathy and age or clinical severity. Significant vestibular impairment is a consistent finding in CMT4C and is present early in disease evolution. The profound imbalance that is so disabling in these patients may result from a combination of proprioceptive loss and vestibular neuropathy, and this would modify the recommended rehabilitation strategies. PMID:24614092

Pérez-Garrigues, Herminio; Sivera, Rafael; Vílchez, Juan Jesús; Espinós, Carmen; Palau, Francesc; Sevilla, Teresa

2014-07-01

347

Evidence for modulation of opioidergic activity in central vestibular processing: A [(18)F] diprenorphine PET study.  

Science.gov (United States)

Animal and functional imaging studies had identified cortical structures such as the parieto-insular vestibular cortex, the retro-insular cortex, or the anterior cingulate cortex belonging to a vestibular cortical network. Basic animal studies revealed that endorphins might be important transmitters involved in cerebral vestibular processing. The aim of the present study was therefore to analyse whether the opioid system is involved in vestibular neurotransmission of humans or not. Changes in opioid receptor availability during caloric air stimulation of the right ear were studied with [(18)F] Fluoroethyl-diprenorphine ([(18)F]FEDPN) PET scans in 10 right-handed healthy volunteers and compared to a control condition. Decrease in receptor availability to [(18)F]FEDPN during vestibular stimulation in comparison to the control condition was significant at the right posterior insular cortex and the postcentral region indicating more endogenous opioidergic binding in these regions during stimulation. These data give evidence that the opioidergic system plays a role in the right hemispheric dominance of the vestibular cortical system in right-handers. PMID:19780041

Baier, Bernhard; Bense, Sandra; Birklein, Frank; Buchholz, Hans-Georg; Mischke, Anja; Schreckenberger, Matthias; Dieterich, Marianne

2010-04-01

348

Endolymphatic sac shunt, labyrinthectomy, and vestibular nerve section in Meniere's disease.  

Science.gov (United States)

Medical treatment for Meniere's disease is effective in controlling vertigo for approximately 85% of patients. However, when disabling vertigo continues, surgical therapy is indicated. Several surgical approaches are performed to control the symptoms of peripheral vestibular disorders refractory to medical measures, each procedure having many technical variations. Surgery is usually reserved for patients with disabling vertigo. Here, the authors discuss surgical options for vertigo control in Meniere's disease and review the literature on outcomes of these management options. The authors discuss endolymphatic sac shunt (ie, endolymphatic mastoid shunt), vestibular nerve section, cochleosacculotomy, and labyrinthectomy. When looking at data based on patient ratings, the authors find that surgery improves vertigo in endolymphatic sac shunt, vestibular nerve section, and labyrinthectomy groups and improves imbalance for the endolymphatic sac shunt and vestibular nerve section groups. Labyrinthectomy and translabyrinthine vestibular nerve section both offer excellent control of intractable vertigo. However, patients undergoing translab yrinthine vestibular nerve section are more likely to show improvement in imbalance and functional disability. This outcome is more likely for diagnoses other than Meniere's disease. There are potential prognostic factors that can be helpful in the preoperative or postoperative counseling of patients undergoing surgical treatment of vertigo. Patients who rate themselves as more disabled before surgery are less likely to achieve the best outcomes. Several other factors, such as duration of disease, contralateral tinnitus, eye disease, and allergy, may play a role. PMID:20713247

Teufert, Karen B; Doherty, Joni

2010-10-01

349

Inner ear vestibular signals regulate bone remodeling via the sympathetic nervous system.  

Science.gov (United States)

The inner ear vestibular system has numerous projections on central brain centers that regulate sympathetic outflow, and skeletal sympathetic projections affect bone remodeling by inhibiting bone formation by osteoblasts and promoting bone resorption by osteoclasts. In this study, we show that bilateral vestibular lesions in mice cause a low bone mass phenotype associated with decreased bone formation and increased bone resorpt ion. This reduction in bone mass is most pronounced in lower limbs, is not associated with reduced locomotor activity or chronic inflammation, and could be prevented by the administration of the ?-blocker propranolol and by genetic deletion of the ?2-adrenergic receptor, globally or specifically in osteoblasts. These results provide novel experimental evidence supporting a functional autonomic link between central proprioceptive vestibular structures and the skeleton. Because vestibular dysfunction often affects the elderly, these results also suggest that age-related bone loss might have a vestibular component, and that patients with inner ear pathologies might be at risk for fracture. Lastly, these data might have relevance to the bone loss observed in microgravity, as vestibular function is altered in this condition as well. This article is protected by copyright. All rights reserved. PMID:25491117

Vignaux, G; Ndong, Jdlc; Perrien, D; Elefteriou, F

2014-12-10

350

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

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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

351

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 | Language: 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

352

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 SciELO Brazil | Language: Portuguese Abstract in portuguese 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 Inte