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Sample records for vestibular neuronitis

  1. Neuronal loss in human medial vestibular nucleus.

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    Alvarez, J C; Díaz, C; Suárez, C; Fernández, J A; González del Rey, C; Navarro, A; Tolivia, J

    1998-08-01

    The data concerning the effects of age on the brainstem are inconsistent, and few works are devoted to the human vestibular nuclear complex. The medial vestibular nucleus (MVN) is the largest nucleus of the vestibular nuclear complex, and it seems to be related mainly to vestibular compensation and vestibulo-ocular reflexes. Eight human brainstems have been used in this work. The specimens were embedded in paraffin, sectioned, and stained by the formaldehyde-thionin technique. Neuron profiles were drawn with a camera lucida at x330. Abercrombie's method was used to estimate the total number of neurons. We used the test of Kolmogorov-Smirnov with the correction of Lilliefors to evaluate the fit of our data to a normal distribution, and a regression analysis was performed to determine if the variation of our data with age was statistically significant. The present study clearly shows that neuronal loss occurs with aging. The total number of neurons decreases with age, from 122,241 +/- 651 cells in a 35-year-old individual to 75,915 +/- 453 cells in an 89-year-old individual. Neuron loss was significant in the caudal and intermediate thirds of the nucleus, whereas the changes in the rostral third were not significant. The nuclear diameter of surviving neurons decreased significantly with age. There is a neuron loss in the MVN that seems to be age-related. It could help explain why elderly people find it hard to compensate for unilateral vestibular deficits. The preservation of neurons in the rostral third could be related to the fact that this area primarily innervates the oculolmotor nuclei; these latter neurons do not decrease in number in other species studied. PMID:9713981

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

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    Dickman, J. David; Angelaki, Dora E.

    2002-01-01

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

  3. Otolith-Canal Convergence In Vestibular Nuclei Neurons

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    Dickman, J. David; Si, Xiao-Hong

    2002-01-01

    The current final report covers the period from June 1, 1999 to May 31, 2002. The primary objective of the investigation was to determine how information regarding head movements and head position relative to gravity is received and processed by central vestibular nuclei neurons in the brainstem. Specialized receptors in the vestibular labyrinths of the inner ear function to detect angular and linear accelerations of the head, with receptors located in the semicircular canals transducing rotational head movements and receptors located in the otolith organs transducing changes in head position relative to gravity or linear accelerations of the head. The information from these different receptors is then transmitted to central vestibular nuclei neurons which process the input signals, then project the appropriate output information to the eye, head, and body musculature motor neurons to control compensatory reflexes. Although a number of studies have reported on the responsiveness of vestibular nuclei neurons, it has not yet been possible to determine precisely how these cells combine the information from the different angular and linear acceleration receptors into a correct neural output signal. In the present project, rotational and linear motion stimuli were separately delivered while recording responses from vestibular nuclei neurons that were characterized according to direct input from the labyrinth and eye movement sensitivity. Responses from neurons receiving convergent input from the semicircular canals and otolith organs were quantified and compared to non-convergent neurons.

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

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

    2002-01-01

    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.

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

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

    2001-01-01

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

  6. Studies of Vestibular Neurons in Normal, Hyper- and Hypogravity

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    Correia, Manning J.

    1996-01-01

    During the past year, pre-, in- and postflight studies were conducted in association with the Axon project for Bion 10 (Cosmos 2229). Recordings were made during pre- and postflight studies, from 118 horizontal semicircular canal afferents and 27 vestibular nucleus neurons in 7 rhesus monkeys; 137 pulse rotation protocols alone were executed (548 acceleration and deceleration responses were curve fit). Usable data was obtained from 127 horizontal afferents concerning their spontaneous discharge. Curve fits and analysis was made of sinusoidal and sum of sinusoidal responses from 42 and 35 horizontal afferents, respectively. Also recordings were made from neurons inflight from the two flight animals. The mean spontaneous rate varied from 128 spikes/sec. during preflight to 92 spikes/sec during postflight (day 5) - a change of 28%. In direct contrast to the results of Cosmos 2044, the best fitted neural adaptation operator (k) and the gain of the pulse response were decreased during post flight when compared to preflight. Surprisingly, the best fitted gain and k values for the sum of sines were slightly elevated during post flight tests. The gain and phase of single sine responses were compared for pre- and post flight tests and compared to a larger population of afferents. In contrast to Cosmos 2044 results where on the first day of post flight testing the gains of the best fitted sine response were skewed toward the higher values of the Miles and Braitman distribution, the gain of the best fitted sine responses during the first day of post flight testing (day 2) during Cosmos 2229 were exactly on the mode of the Miles and Braitman distribution. Thus, at least for the periodic stimuli, (pulses and sine waves) we found no change in gain and neural adaptation during post flight testing following Cosmos 2229. This conclusion is different from the one derived following the Cosmos 2044 flight. Cosmos flight 2229 differed from Cosmos flight 2044 in several significant ways: For example, during preflight, (1) The animals preflight training was different (less well trained on the gaze task) and (2) the animals were exposed to more experimental manipulations (surgical and rotational). Inflight, (1) the animals were required to make a pointing gesture (motor response) in association with eye movements to obtain reward, (2) the inflight diet was different (more balanced), (3) the feeder for one of the animals clogged following 9 days of flight resulting in evident dehydration and probably less head motion exposure in that monkey and (4) there was limited video taping of the monkeys in space. During postflight, (1) we were unable to test the flight animals until 26 hours postflight as compared to 14.5 hours during Cosmos 2044, (2) the animals received significantly more exposure to motion stimuli during postflight testing than during Cosmos 2044. These differences in the vestibular environment will require analysis of several parameters other than just neural and eye movement responses. For example, computer programs will have to be written and used to recover and quantify the number of head movements made by each animal during flight. This activity is critical to the production of neural adaptation and increased gain.

  7. Restricted loss of olivocochlear but not vestibular efferent neurons in the senescent gerbil (Meriones unguiculatus

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    Susanne Radtke-Schuller

    2015-02-01

    Full Text Available Degeneration of hearing and vertigo are symptoms of age-related auditory and vestibular disorders reflecting multifactorial changes in the peripheral and central nervous system whose interplay remains largely unknown. Originating bilaterally in the brain stem, vestibular and auditory efferent cholinergic projections exert feedback control on the peripheral sensory organs, and modulate sensory processing. We studied age-related changes in the auditory and vestibular efferent systems by evaluating number of cholinergic efferent neurons in young adult and aged gerbils, and in cholinergic trigeminal neurons serving as a control for efferents not related to the inner ear. We observed a significant loss of olivocochlear neurons in aged compared to young adult animals, whereas the overall number of lateral superior olive cells was not reduced in aging. Although the loss of lateral and medial olivocochlear neurons was uniform and equal on both sides of the brain, there were frequency-related differences within the lateral olivocochlear neurons, where the decline was larger in the medial limb of the superior olivary nucleus (high frequency representation than in the lateral limb (middle-to-low frequency representation. In contrast, neither the number of vestibular efferent neurons, nor the population of motor trigeminal neurons were significantly reduced in the aged animals. These observations suggest differential effects of aging on the respective cholinergic efferent brainstem systems.

  8. Integrative responses of neurons in nucleus tractus solitarius to visceral afferent stimulation and vestibular stimulation in vertical planes

    OpenAIRE

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

    2011-01-01

    Anatomical studies have demonstrated that the vestibular nuclei project to nucleus tractus solitarius (NTS), but little is known about the effects of vestibular inputs on NTS neuronal activity. Furthermore, lesions of NTS abolish vomiting elicited by a variety of different triggering mechanisms, including vestibular stimulation, suggesting that emetic inputs may converge on the same NTS neurons. As such, an emetic stimulus that activates gastrointestinal (GI) receptors could alter the respons...

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

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    SophieGaboyard-Niay

    2012-06-01

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

  10. A model for the characterization of the spatial properties in vestibular neurons

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    Angelaki, D. E.; Bush, G. A.; Perachio, A. A.

    1992-01-01

    Quantitative study of the static and dynamic response properties of some otolith-sensitive neurons has been difficult in the past partly because their responses to different linear acceleration vectors exhibited no "null" plane and a dependence of phase on stimulus orientation. The theoretical formulation of the response ellipse provides a quantitative way to estimate the spatio-temporal properties of such neurons. Its semi-major axis gives the direction of the polarization vector (i.e., direction of maximal sensitivity) and it estimates the neuronal response for stimulation along that direction. In addition, the semi-minor axis of the ellipse provides an estimate of the neuron's maximal sensitivity in the "null" plane. In this paper, extracellular recordings from otolith-sensitive vestibular nuclei neurons in decerebrate rats were used to demonstrate the practical application of the method. The experimentally observed gain and phase dependence on the orientation angle of the acceleration vector in a head-horizontal plane was described and satisfactorily fit by the response ellipse model. In addition, the model satisfactorily fits neuronal responses in three-dimensions and unequivocally demonstrates that the response ellipse formulation is the general approach to describe quantitatively the spatial properties of vestibular neurons.

  11. Cat vestibular neurons that exhibit different responses to active and passive yaw head rotations

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    Robinson, F. R.; Tomko, D. L.

    1987-01-01

    Neurons in the vestibular nuclei were recorded in alert cats during voluntary yaw rotations of the head and during the same rotations delivered with a turntable driven from a record of previous voluntary movements. During both voluntary and passive rotations, 35 percent (6/17) of neurons tested responded at higher rates or for a larger part of the movement during voluntary movements than during the same rotations delivered with the turntable. Neck sensory input was evaluated separately in many of these cells and can account qualitatively for the extra firing present during active movement.

  12. Spontaneous synaptic activity in chick vestibular nucleus neurons during the perinatal period.

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    Shao, M; Hirsch, J C; Giaume, C; Peusner, K D

    2004-01-01

    The principal cells of the chick tangential nucleus are second-order vestibular neurons involved in the vestibuloocular and vestibulocollic reflexes. The spontaneous synaptic activity of morphologically identified principal cells was characterized in brain slices from 1-day-old hatchlings (H1) using whole-cell voltage-clamp recordings and Cs-gluconate pipet solution. The frequency was 1.45 Hz for spontaneous excitatory postsynaptic currents (sEPSCs) and 1.47 Hz for spontaneous inhibitory postsynaptic currents (sIPSCs). Using specific neurotransmitter receptor antagonists, all of the sEPSCs were identified as AMPA receptor-mediated events, whereas 56% of the sIPSCs were glycine and 44% were GABA(A) receptor-mediated events. On exposure to TTX, the frequency of EPSCs decreased by 68%, while the frequency of IPSCs decreased by 33%, indicating greater EPSC dependency on presynaptic action potentials. These data on spontaneous synaptic activity at H1 were compared with those obtained in previous studies of 16-day old embryos (E16). After birth, the spontaneous synaptic activity exhibited increased EPSC frequency, increased ratio for excitatory to inhibitory events, increased percentage of TTX-dependent EPSCs, and faster kinetics. In addition, the ratio for glycine/GABA receptor-mediated events increased significantly. Altogether, these data indicate that at hatching spontaneous synaptic activity of vestibular nucleus neurons in brain slices of the chick tangential nucleus undergoes appreciable changes, with increased frequency of EPSCs and glycinergic activity playing more important roles compared with the late-term chick embryo when GABAergic activity prevailed. The definition of this developmental pattern of synaptic activity in vestibular nucleus neurons should contribute to understanding how vestibular reflex activity is established in the hatchling chick. PMID:15219671

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

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    Perachio, Adrian A. (Principal Investigator)

    1996-01-01

    The following topics are reported: neurophysiological studies on MVN neurons during vestibular compensation; effects of spinal cord lesions on VNC neurons during compensation; a closed-loop vestibular compensation model for horizontally canal-related MVN neurons; spatiotemporal convergence in VNC neurons; contributions of irregularly firing vestibular afferents to linear and angular VOR's; application to flight studies; metabolic measures in vestibular neurons; immediate early gene expression following vestibular stimulation; morphological studies on primary afferents, central vestibular pathways, vestibular efferent projection to the vestibular end organs, and three-dimensional morphometry and imaging.

  14. Two-dimensional spatiotemporal coding of linear acceleration in vestibular nuclei neurons

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    Angelaki, D. E.; Bush, G. A.; Perachio, A. A.

    1993-01-01

    Response properties of vertical (VC) and horizontal (HC) canal/otolith-convergent vestibular nuclei neurons were studied in decerebrate rats during stimulation with sinusoidal linear accelerations (0.2-1.4 Hz) along different directions in the head horizontal plane. A novel characteristic of the majority of tested neurons was the nonzero response often elicited during stimulation along the "null" direction (i.e., the direction perpendicular to the maximum sensitivity vector, Smax). The tuning ratio (Smin gain/Smax gain), a measure of the two-dimensional spatial sensitivity, depended on stimulus frequency. For most vestibular nuclei neurons, the tuning ratio was small at the lowest stimulus frequencies and progressively increased with frequency. Specifically, HC neurons were characterized by a flat Smax gain and an approximately 10-fold increase of Smin gain per frequency decade. Thus, these neurons encode linear acceleration when stimulated along their maximum sensitivity direction, and the rate of change of linear acceleration (jerk) when stimulated along their minimum sensitivity direction. While the Smax vectors were distributed throughout the horizontal plane, the Smin vectors were concentrated mainly ipsilaterally with respect to head acceleration and clustered around the naso-occipital head axis. The properties of VC neurons were distinctly different from those of HC cells. The majority of VC cells showed decreasing Smax gains and small, relatively flat, Smin gains as a function of frequency. The Smax vectors were distributed ipsilaterally relative to the induced (apparent) head tilt. In type I anterior or posterior VC neurons, Smax vectors were clustered around the projection of the respective ipsilateral canal plane onto the horizontal head plane. These distinct spatial and temporal properties of HC and VC neurons during linear acceleration are compatible with the spatiotemporal organization of the horizontal and the vertical/torsional ocular responses, respectively, elicited in the rat during linear translation in the horizontal head plane. In addition, the data suggest a spatially and temporally specific and selective otolith/canal convergence. We propose that the central otolith system is organized in canal coordinates such that there is a close alignment between the plane of angular acceleration (canal) sensitivity and the plane of linear acceleration (otolith) sensitivity in otolith/canal-convergent vestibular nuclei neurons.

  15. VESTIBULAR VERTIGO

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    M V Zamergrad

    2009-03-01

    Full Text Available The authors consider the cardinal causes of vestibular vertigo, a benign paroxysmal positional vertigo, Meniere's disease, vestibular neuroni-tis, vestibular migraine, cerebrovascular diseases. It gives brief data on the etiology, pathogenesis, clinical manifestations, and treatment of these diseases. The diagnosis of the latter is largely based on a patientKhs complaints and medical history data and frequently requires no additional instrumental study. The currently available treatments for various diseases manifesting as vestibular vertigo are analyzed. Vestibular exercises and rehabilitation maneuvers that are effective in benign positional vertigo are noted to play an important role. In addition, methods for drug stimulation of vestibular compensation in central and peripheral vestibulopathies are described.

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

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

    2000-01-01

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

  17. Vestibular Neuronitis

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    ... Medical Dictionary Also of Interest (Quiz) Dizziness and Vertigo (Video) Vertigo (News) Preventing Ear Infections Additional Content Medical News ... Overview of the Inner Ear Benign Paroxysmal Positional Vertigo (Benign Positional Vertigo) Meniere Disease Herpes Zoster Oticus ...

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

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    GayRHolstein

    2012-02-01

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

  19. Peripheral Vestibular System Disease in Vestibular Schwannomas

    DEFF Research Database (Denmark)

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

    2015-01-01

    patients with VS. METHODS: Retrospective analysis of vestibular system histopathology in temporal bones from 17 patients with unilateral VS. The material was obtained from The Copenhagen Temporal Bone Collection. RESULTS: Vestibular schwannomas were associated with atrophy of the vestibular ganglion, loss...... of fiber density of the peripheral vestibular nerve branches, and atrophy of the neuroepithelium of the vestibular end organs. In cases with small tumors, peripheral disease occurred only in the tissue structures innervated by the specific nerve from which the tumor originated. CONCLUSION: Vestibular...... schwannomas are associated with distinctive disease of the peripheral vestibular tissue structures, suggesting anterograde degeneration and that dizziness in these patients may be caused by deficient peripheral vestibular nerve fibers, neurons, and end organs. In smaller tumors, a highly localized disease...

  20. Firing behavior of vestibular neurons during active and passive head movements: vestibulo-spinal and other non-eye-movement related neurons

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

    1999-01-01

    The firing behavior of 51 non-eye movement related central vestibular neurons that were sensitive to passive head rotation in the plane of the horizontal semicircular canal was studied in three squirrel monkeys whose heads were free to move in the horizontal plane. Unit sensitivity to active head movements during spontaneous gaze saccades was compared with sensitivity to passive head rotation. Most units (29/35 tested) were activated at monosynaptic latencies following electrical stimulation of the ipsilateral vestibular nerve. Nine were vestibulo-spinal units that were antidromically activated following electrical stimulation of the ventromedial funiculi of the spinal cord at C1. All of the units were less sensitive to active head movements than to passive whole body rotation. In the majority of cells (37/51, 73%), including all nine identified vestibulo-spinal units, the vestibular signals related to active head movements were canceled. The remaining units (n = 14, 27%) were sensitive to active head movements, but their responses were attenuated by 20-75%. Most units were nearly as sensitive to passive head-on-trunk rotation as they were to whole body rotation; this suggests that vestibular signals related to active head movements were cancelled primarily by subtraction of a head movement efference copy signal. The sensitivity of most units to passive whole body rotation was unchanged during gaze saccades. A fundamental feature of sensory processing is the ability to distinguish between self-generated and externally induced sensory events. Our observations suggest that the distinction is made at an early stage of processing in the vestibular system.

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

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    S.H.Sarkisyan

    2011-02-01

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

  2. Decreased calcium-activated potassium channels by hypoxia causes abnormal firing in the spontaneous firing medial vestibular nuclei neurons.

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    Xie, Hong; Zhang, Yu-qin; Pan, Xin-liang; Wu, Shu-hui; Chen, Xiang; Wang, Jie; Liu, Hua; Qian, Xiao-zhong; Liu, Zhi-guo; Liu, Lie-Ju

    2015-10-01

    Vertebrobasilar insufficiency (VBI) presents complex varied clinical symptoms, including vertigo and hearing loss. Little is known, however, about how Ca(2+)-activated K(+) channel attributes to the medial vestibular nucleus (MVN) neural activity in VBI. To address this issue, we performed whole-cell patch clamp and quantitative polymerase chain reaction (qPCR) to examine the effects of hypoxia on neural activity and the changes of the large conductance Ca(2+) activated K(+) channels (BKCa channels) in the MVN neurons in brain slices of male C57BL/6 mice. Brief hypoxic stimuli of the brain slices containing MVN were administrated by switching the normoxic artificial cerebrospinal fluid (ACSF) equilibrated with 21% O2/5% CO2 to hypoxic ACSF equilibrated with 5% O2/5% CO2 (balance N2). 3-min hypoxia caused a depolarization in the resting membrane potential (RM) in 8/11 non-spontaneous firing MVN neurons. 60/72 spontaneous firing MVN neurons showed a dramatic increase in firing frequency and a depolarization in the RM following brief hypoxia. The amplitude of the afterhyperpolarization (AHPA) was significantly decreased in both type A and type B spontaneous firing MVN neurons. Hypoxia-induced firing response was alleviated by pretreatment with NS1619, a selective BKCa activator. Furthermore, brief hypoxia caused a decrease in the amplitude of iberiotoxin-sensitive outward currents and mRNA level of BKCa in MVN neurons. These results suggest that BKCa channels protect against abnormal MVN neuronal activity induced by hypoxia, and might be a key target for treatment of vertigo and hearing loss in VBI. PMID:25173490

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

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    S.H. Sarkisyan

    2009-09-01

    Full Text Available The background neuronal impulse activity of right and left spinal vestibular nuclei of rats was carried out in norm and after unilateral labyrinthectomy (UL on 2-d, 7-th, 12- th and 17-th days. It was shown by computer analysis, that characteristics of both nuclei neurons impulse activity in the control group have revealed primary asymmetry of the average frequency and coefficient of variation (accordingly 11,0±1,0 Hz; 92,7± 5,2% and 34,6±2,7 Hz; and 66,4±3,8%, p<0,01. It is shown that on 7-th day following UL value of the coefficient of variation in both sides is justified (accordingly 76,6 ±2,5% and 72,8±2,2% and the value of the average frequency corresponded to source (9,2±0,7 Hz and 32,2±2,8Hz. We discussed particularities of the process to compensations and functional importance got result.

  4. VESTIBULAR REHABILITATION

    Directory of Open Access Journals (Sweden)

    Maksim Valer'evich Zamergrad

    2009-06-01

    Full Text Available Vestibular disorders are a frequent abnormality that physicians of various specialties have to encounter. Vestibular and equilibrium disorders are particularly common in elderly patients. In this case they are frequently a cause of falls and various injuries. Vestibular rehabilitation is the most important component of treatment for vestibular and equilibrium disorders. The paper considers the basic mechanisms of vestibular compensation, discusses vestibular rehabilitation procedures by doing routine exercises and by using various biofeedback crunches. In particular, it describes the principle of operation of a posturography platform, a SwayStar system for the diagnosis and therapy of vestibular disorders, and a Brainport device for vestibular rehabilitation. The current methods for drug stimulation of vestibular compensation are discussed. Vestibular rehabilitation used in the complex therapy of equilibrium disorders is stressed to considerably enhance therapeutic effectiveness, to cause a reduction in the risk of falls, and to increase quality of life in patients with vestibular disorders

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

    Science.gov (United States)

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

    1999-01-01

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

  6. Vestibular migraine

    DEFF Research Database (Denmark)

    Lempert, Thomas; Olesen, Jes; Furman, Joseph; Waterston, John; Seemungal, Barry; Carey, John; Bisdorff, Alexander; Versino, Maurizio; Evers, Stefan; Newman-Toker, David

    2012-01-01

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

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

    OpenAIRE

    Zhang, Yi-Bo; Zhang, Ru; Zhang, Wei-Feng; Peter S. Steyger; Dai, Chun-Fu

    2011-01-01

    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...

  8. Spatial coordination by descending vestibular signals. 2. Response properties of medial and lateral vestibulospinal tract neurons in alert and decerebrate cats.

    Science.gov (United States)

    Iwamoto, Y; Perlmutter, S I; Baker, J F; Peterson, B W

    1996-02-01

    Spatial response properties of medial (MVST) and lateral (LVST) vestibulospinal tract neurons were studied in alert and decerebrate cats during sinusoidal angular rotations of the whole body in the horizontal and many vertical planes. Of 220 vestibulospinal neurons with activity modulated during 0.5-Hz sinusoidal rotations, 200 neurons exhibited response gains that varied as a cosine function of stimulus orientation and phases that were near head velocity for rotation planes far from the minimum response plane. A maximum activation direction vector (MAD), which represents the axis and direction of rotation that maximally excites the neuron, was calculated for these neurons. Spatial properties of secondary MVST neurons in alert and decerebrate animals were similar. The responses of 88 of 134 neurons (66%) could be accounted for by input from one semicircular canal pair. Of these, 84 had responses consistent with excitation from the ipsilateral canal of the pair (13 horizontal, 27 anterior, 44 posterior) and 4 with excitation from the contralateral horizontal canal. The responses of the remaining 46 (34%) neurons suggested convergent inputs. The activity of 38 of these was significantly modulated by both horizontal and vertical rotations. Twelve neurons (9%) had responses that were consistent with input from both vertical canal pairs, including 9 cells with MADs near the roll axis. Thirty-two secondary MVST neurons (24%) had type II yaw and/or roll responses. The spatial response properties of 18 secondary LVST neurons, all studied in decerebrate animals, were different from those of secondary MVST neurons. Sixteen neurons (89%) had type II yaw and/or roll responses, and 12 (67%) appeared to receive convergent canal pair input. Convergent input was more common on higher-order vestibulospinal neurons than on secondary neurons. These results suggest that MVST and LVST neurons and previously reported vestibulo-ocular neurons transmit functionally different signals. LVST neurons, particularly those with MADs close to the roll axis, may be involved in the vestibular-limb reflex. The combination of vertical and ipsilateral horizontal canal input on many secondary MVST neurons suggests a contribution to the vestibulocollic reflex. However, in contrast to most neck muscles, very few neurons had maximum vertical responses near pitch. PMID:8721157

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

    Science.gov (United States)

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

    2013-02-01

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

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

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    KennaPeusner

    2012-02-01

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

  11. Vestibular interactions in the thalamus

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    Aaron Camp

    2015-12-01

    Full Text Available It has long been known that the vast majority of all information en route to the cerebral cortex must first pass through the thalamus. The long held view that the thalamus serves as a simple hi fidelity relay station for sensory information to the cortex, however, has over recent years been dispelled. Indeed, multiple projections from the vestibular nuclei to thalamic nuclei (including the ventrobasal nuclei, and the geniculate bodies- regions typically associated with other modalities- have been described. Further, some thalamic neurons have been shown to respond to stimuli presented from across sensory modalities. For example, neurons in the rat anterodorsal and laterodorsal nuclei of the thalamus respond to visual, vestibular, proprioceptive and somatosensory stimuli and integrate this information to compute heading within the environment. Together, these findings imply that the thalamus serves crucial integrative functions, at least in regard to vestibular processing, beyond that imparted by a “simple” relay. In this mini review we outline the vestibular inputs to the thalamus and provide some clinical context for vestibular interactions in the thalamus. We then focus on how vestibular inputs interact with other sensory systems and discuss the multisensory integration properties of the thalamus.

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

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    Enrique Soto

    2014-03-01

    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.

  13. Major diseases manifesting by vestibular vertigo: Treatment and rehabilitation

    Directory of Open Access Journals (Sweden)

    V. A. Parfenov

    2015-06-01

    Full Text Available Betahistine hydrochloride is the drug of choice for the treatment of vestibular vertigo in the presence of benign paroxysmal positional vertigo, Meniere's disease, and vestibular neuronitis. Effective combination therapy regimens that contain, along with drugs from other pharmacological groups, betahistine hydrochloride that improves blood circulation in the vestibular structures, accelerates vestibular compensation, and prevents recurrent dizzy spells, have been elaborated to treat central vestibular vertigo in migraine-associated dizziness and in acute cerebrovascular accident. Of great importance is a combination of drug therapy and the current rehabilitation methods for vestibular diseases, which contribute to prompter and complete recovery of vestibular function. Biofeedback instrumental rehabilitation techniques using a stabilographic platformare highly effective. Successful treatment depends on the correctness of the established diagnosis. The diagnosis of peripheral and central vestibular vertigo frequently poses challenges. The essential reason for this is physicians’ unawareness about outpatient methods for the diagnosis of major vestibular diseases when the patient is at a doctor. It is important to follow a vestibular system study protocol since the use and correct assessment of diagnostic tests in most cases make it possible to estimate the degree of vestibular analyzer injury and to make an accurate diagnosis. The paper describes the diseases that are the most common causes of vestibular vertigo. The most effective methods for their treatment and current rehabilitation methods are discussed.

  14. Genetics of Recurrent Vertigo and Vestibular Disorders

    OpenAIRE

    Gazquez, Irene; Lopez-Escamez, Jose A.

    2011-01-01

    We present recent advances in the genetics of recurrent vertigo, including familial episodic ataxias, migraneous vertigo, bilateral vestibular hypofunction and Meniere’s disease. Although several vestibular disorders are more common within families, the genetics of vestibulopathies is largely not known. Genetic loci and clinical features of familial episodic ataxias have been defined in linkage disequilibrium studies with mutations in neuronal genes KCNA1 and CACNA1A. Migrainous vertigo is a ...

  15. [Vestibular migraine].

    Science.gov (United States)

    Hansen, Lars Juul; Kirchmann, Malene; Friis, Morten

    2015-12-14

    Dizziness caused by migraine, vestibular migraine (VM), has been highly debated over the last three decades. The co-morbidity of migraine and dizziness is higher than a random concurrence. One third of the patients with migraine and dizziness have VM. Recently, The International Headache Society approved VM as a diagnostic entity and the diagnostic criteria for VM appear in the appendix for The International Classification of Headache Disorders. VM is common but often underdiagnosed. Treatment follows migraine management guidelines although evidence is sparse. PMID:26692036

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

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    Loreta Ungureanu

    2012-09-01

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

  17. Sensory processing in the vestibular nuclei during active head movements

    Science.gov (United States)

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

    2000-01-01

    Many secondary vestibular neurons are sensitive to head on trunk rotation during reflex-induced and voluntary head movements. During passive whole body rotation the interaction of head on trunk signals related to the vestibulo-collic reflex with vestibular signals increases the rotational gain of many secondary vestibular neurons, including many that project to the spinal cord. In some units, the sensitivity to head on trunk and vestibular input is matched and the resulting interaction produces an output that is related to the trunk velocity in space. In other units the head on trunk inputs are stronger and the resulting interaction produces an output that is larger during the reflex. During voluntary head movements, inputs related to head on trunk movement combine destructively with vestibular signals, and often cancel the sensory reafferent consequences of self-generated movements. Cancellation of sensory vestibular signals was observed in all of the antidromically identified secondary vestibulospinal units, even though many of these units were not significantly affected by reflexive head on trunk movements. The results imply that the inputs to vestibular neurons related to head on trunk rotation during reflexive and voluntary movements arise from different sources. We suggest that the relative strength of reflexive head on trunk input to different vestibular neurons might reflect the different functional roles they have in controlling the posture of the neck and body.

  18. Rehabilitation in vestibular system diseases

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    Maksim Valeryevich Zamergrad

    2013-03-01

    Full Text Available Vestibular rehabilitation is an important component of combination treatment in a patient with vertigo. Vestibular rehabilitation is indicated for different diseases of the central or peripheral vestibular system. The goal of vestibular rehabilitation is to ensure gaze stabilization, to train postural stability, and to reduce subjective vertigo. Vestibular rehabilitation is based on the stimulation of vestibular adaptation, sensory substitution, and habituation. Vestibular suppressants, inadequate mobility, anxiety, and depression decelerate vestibular compensation whereas early activation, mobility, and betaserc use accelerate it.

  19. Procedures for restoring vestibular disorders

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    Walther, Leif Erik

    2005-09-01

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

  20. Types of Vestibular Disorders

    Science.gov (United States)

    ... and sac, which help maintain the volume and ionic composition of endolymph necessary for transmitting hearing and ... hearing, balance, or both. Many chemicals have ototoxic potential. Read more... Pediatric Vestibular Disorders The vestibular system ...

  1. Pediatric Vestibular Disorders

    Science.gov (United States)

    ... vestibular dysfunction. With bilateral and central problems, some adaptation is needed to achieve near normal function. Children ... also help integrate vestibular training into activities at school. They should work closely with the parents to ...

  2. Aging and the human vestibular nuclei: morphometric analysis.

    Science.gov (United States)

    Alvarez, J C; Díaz, C; Suárez, C; Fernández, J A; González del Rey, C; Navarro, A; Tolivia, J

    2000-04-14

    The data concerning the effects of age on the brainstem are scarce and few works are devoted to the human vestibular nuclear complex. The study of the effects of aging in the vestibular nuclei could have clinical interest due to the high prevalence of balance control and gait problems in the elderly. We have used in this work eight human brainstems of different ages sectioned and stained by the formaldehyde-thionin technique. The neuron's profiles were drawn with a camera lucida and Abercrombie's method was used to estimate the total number of neurons. The test of Kolmogorov-Smirnov with the correction of Lilliefors was used to evaluate the fit of our data to a normal distribution and a regression analysis was done to determine if the variation of our data with age was statistically significant. Aging does not affect the volume or length of the vestibular nuclear complex. Our results clearly show that neuronal loss occurs with aging in the descending (DVN), medial (MVN), and lateral (LVN) vestibular nuclei, but not in the superior (SVN). There are changes in the proportions of neurons of different sizes but they are not statistically significant. The neuronal loss could be related with the problems that elderly people have to compensate unilateral vestibular lesions and the alterations of the vestibulospinal reflexes. The preservation of SVN neurons can explain why vestibulo-ocular reflexes are compensated after unilateral vestibular injuries. PMID:10802120

  3. Differential central projections of vestibular afferents in pigeons

    Science.gov (United States)

    Dickman, J. D.; Fang, Q.

    1996-01-01

    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.

  4. What galvanic vestibular stimulation actually activates

    Directory of Open Access Journals (Sweden)

    IanSCurthoys

    2012-07-01

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

  5. Specific vestibular exercises in the treatment of vestibular neuritis

    Directory of Open Access Journals (Sweden)

    Komazec Zoran

    2004-01-01

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

  6. Distinct vestibular effects on early and late somatosensory cortical processing in humans.

    Science.gov (United States)

    Pfeiffer, Christian; van Elk, Michiel; Bernasconi, Fosco; Blanke, Olaf

    2016-01-15

    In non-human primates several brain areas contain neurons that respond to both vestibular and somatosensory stimulation. In humans, vestibular stimulation activates several somatosensory brain regions and improves tactile perception. However, less is known about the spatio-temporal dynamics of such vestibular-somatosensory interactions in the human brain. To address this issue, we recorded high-density electroencephalography during left median nerve electrical stimulation to obtain Somatosensory Evoked Potentials (SEPs). We analyzed SEPs during vestibular activation following sudden decelerations from constant-velocity (90°/s and 60°/s) earth-vertical axis yaw rotations and SEPs during a non-vestibular control period. SEP analysis revealed two distinct temporal effects of vestibular activation: An early effect (28-32ms post-stimulus) characterized by vestibular suppression of SEP response strength that depended on rotation velocity and a later effect (97-112ms post-stimulus) characterized by vestibular modulation of SEP topographical pattern that was rotation velocity-independent. Source estimation localized these vestibular effects, during both time periods, to activation differences in a distributed cortical network including the right postcentral gyrus, right insula, left precuneus, and bilateral secondary somatosensory cortex. These results suggest that vestibular-somatosensory interactions in humans depend on processing in specific time periods in somatosensory and vestibular cortical regions. PMID:26466979

  7. Labyrinthitis and Vestibular Neuritis

    Science.gov (United States)

    ... balancing strategies, a test called computerized dynamic posturography (CDP) is sometimes used. After the evaluation, personalized vestibular ... more comfortable, can prolong or even prevent the process of adaptation. Authors: Charlotte L. Shupert, PhD with ...

  8. Vulvar vestibular papillomatosis

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    Wollina U

    2010-01-01

    Full Text Available Vulvar vestibular papillomatosis is considered an anatomical variant of the vulva. Recognition of this condition enables one to distinguish it from warts and therefore avoid unnecessary therapy. A 29-year-old lady presented to this clinic with a history of ?small growths? in her vulva since two years. Examination identified skin colored translucent papules; some of them appeared digitate and were seen on the vestibule and inner aspect of both labia minora. They were soft to feel and non-tender. Few lesions looked like elongated pearly penile papules. A provisional diagnosis of vestibular papillomatosis was made and a biopsy was done. It showed finger-like protrusions of loosely arranged subdermal tissue with blood vessels and which were covered by normal mucosal epithelium. No koilocytes were seen and the diagnosis of vestibular papillomatosis was confirmed. We believe that this is the first case report of vulvar vestibular papillomatosis in Indian dermatologic literature.

  9. Angiogenesis in vestibular schwannomas

    DEFF Research Database (Denmark)

    Møller, Martin Nue; Werther, Kim; Nalla, Amarnadh; Stangerup, Sven-Eric; Thomsen, Jens; Bøg-Hansen, Thorkild C; Nielsen, Hans Jørgen; Cayé-Thomasen, Per

    2010-01-01

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

  10. Vestibular function testing.

    LENUS (Irish Health Repository)

    Lang, E E

    2010-06-01

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

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

    Scientific Electronic Library Online (English)

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

    2014-09-01

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

  12. Deregulated genes in sporadic vestibular schwannomas

    DEFF Research Database (Denmark)

    Cayé-Thomasen, Per; Helweg-Larsen, Rehannah Holga Andrea; Stangerup, Sven-Eric; Thomsen, Jens Christian; Nielsen, Finn Cilius

    2010-01-01

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

  13. Vestibular tributaries to the vein of the vestibular aqueduct

    DEFF Research Database (Denmark)

    Hansen, Jesper Marsner; Qvortrup, Klaus; Friis, Morten

    2010-01-01

    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....

  14. Surgical Procedures for Vestibular Dysfunction

    Science.gov (United States)

    ... Desorden Vestibular/Vértigo - En Español הפרעות וסטיבולריות Paid Advertisement Disclaimer Information on this website is not intended ... vestibular system dysfunction, surgery may be considered. The type of surgery performed depends upon each individual's diagnosis ...

  15. New insights into pathophysiology of vestibular migraine.

    Science.gov (United States)

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

    2015-01-01

    Vestibular migraine (VM) is a common disorder in which genetic, epigenetic, and environmental factors probably contribute to its development. The pathophysiology of VM is unknown; nevertheless in the last few years, several studies are contributing to understand the neurophysiological pathways involved in VM. The current hypotheses are mostly based on the knowledge of migraine itself. The evidence of trigeminal innervation of the labyrinth vessels and the localization of vasoactive neuropeptides in the perivascular afferent terminals of these trigeminal fibers support the involvement of the trigemino-vascular system. The neurogenic inflammation triggered by activation of the trigeminal-vestibulocochlear reflex, with the subsequent inner ear plasma protein extravasation and the release of inflammatory mediators, can contribute to a sustained activation and sensitization of the trigeminal primary afferent neurons explaining VM symptoms. The reciprocal connections between brainstem vestibular nuclei and the structures that modulate trigeminal nociceptive inputs (rostral ventromedial medulla, ventrolateral periaqueductal gray, locus coeruleus, and nucleus raphe magnus) are critical to understand the pathophysiology of VM. Although cortical spreading depression can affect cortical areas involved in processing vestibular information, functional neuroimaging techniques suggest a dysmodulation in the multimodal sensory integration and processing of vestibular and nociceptive information, resulting from a vestibulo-thalamo-cortical dysfunction, as the pathogenic mechanism underlying VM. The elevated prevalence of VM suggests that multiple functional variants may confer a genetic susceptibility leading to a dysregulation of excitatory-inhibitory balance in brain structures involved in the processing of sensory information, vestibular inputs, and pain. The interactions among several functional and structural neural networks could explain the pathogenic mechanisms of VM. PMID:25705201

  16. New Insights into Pathophysiology of Vestibular Migraine

    Science.gov (United States)

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

    2015-01-01

    Vestibular migraine (VM) is a common disorder in which genetic, epigenetic, and environmental factors probably contribute to its development. The pathophysiology of VM is unknown; nevertheless in the last few years, several studies are contributing to understand the neurophysiological pathways involved in VM. The current hypotheses are mostly based on the knowledge of migraine itself. The evidence of trigeminal innervation of the labyrinth vessels and the localization of vasoactive neuropeptides in the perivascular afferent terminals of these trigeminal fibers support the involvement of the trigemino-vascular system. The neurogenic inflammation triggered by activation of the trigeminal-vestibulocochlear reflex, with the subsequent inner ear plasma protein extravasation and the release of inflammatory mediators, can contribute to a sustained activation and sensitization of the trigeminal primary afferent neurons explaining VM symptoms. The reciprocal connections between brainstem vestibular nuclei and the structures that modulate trigeminal nociceptive inputs (rostral ventromedial medulla, ventrolateral periaqueductal gray, locus coeruleus, and nucleus raphe magnus) are critical to understand the pathophysiology of VM. Although cortical spreading depression can affect cortical areas involved in processing vestibular information, functional neuroimaging techniques suggest a dysmodulation in the multimodal sensory integration and processing of vestibular and nociceptive information, resulting from a vestibulo-thalamo-cortical dysfunction, as the pathogenic mechanism underlying VM. The elevated prevalence of VM suggests that multiple functional variants may confer a genetic susceptibility leading to a dysregulation of excitatory–inhibitory balance in brain structures involved in the processing of sensory information, vestibular inputs, and pain. The interactions among several functional and structural neural networks could explain the pathogenic mechanisms of VM. PMID:25705201

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

    Directory of Open Access Journals (Sweden)

    M. V. Zamergrad

    2014-10-01

    Full Text Available Dizziness is a common symptom in neurological and general medical practice. In most cases it is caused by diseases of the central or peripheral vestibular system. The most common vestibular system diseases include benign paroxysmal postural vertigo, dizziness, Meniere's disease, vestibular neuronitis, and cerebrovascular diseases. One of the main treatments for the diseases accompanied by dizziness is vestibular rehabilitation that is a complex of exercises, the goal of which is to stimulate vestibular compensation. Adequate vestibular compensation allows a patient to get rid of dizziness and unsteadiness even though vestibular system injury is irreversible. Some medications are able to enhance the efficiency of vestibular rehabilitation. At the same time, the optimal duration of treatment for the most common vestibular disorders has not beenadequately explored. The paper gives the results of an observational program, whose purpose was to determine the optimal duration of vestibular rehabilitation in combination with the use of tanakan in patients with non-progressive unilateral peripheral vestibular disorder.Patients and methods. Data on 46 patients aged 19 to 70 years who underwent vestibular rehabilitation and took tanakan for vertigo caused by vestibular neuronitis (n = 44, labyrinthitis (n =1, or Ramsay Hunt syndrome (n = 1 were analyzed. All the patients were examined four times. The symptoms were recorded and the histories of disease were considered. The degree of vestibular disorders, including vertigo, was assessed when collecting complaints. The symptoms of vertigo were objectivized using its vertigo rating scale and five-point subjective rating scale for vertigo. All the patients underwent standard somatic and neurological examinations and videonystagmography. During the first visit after diagnosis, vestibular exercises were chosen for the patients and tanakan was used in a dose of 40 mg thrice daily to accelerate vestibularcompensation. During visits 2, 3, and 4, the symptoms of the disease were recorded in the patients and the time course of treatment-induced changes in their status was estimated.Results. The optimal duration of treatment was established to be at least 2 months. Vestibular exercises in combination with the intake of tanakan resulted in a reduction in the symptoms of vestibular dysfunction and in emotional improvement in the patients.

  18. Computational Approaches to Vestibular Research

    Science.gov (United States)

    Ross, Muriel D.; Wade, Charles E. (Technical Monitor)

    1994-01-01

    The Biocomputation Center at NASA Ames Research Center is dedicated to a union between computational, experimental and theoretical approaches to the study of neuroscience and of life sciences in general. The current emphasis is on computer reconstruction and visualization of vestibular macular architecture in three-dimensions (3-D), and on mathematical modeling and computer simulation of neural activity in the functioning system. Our methods are being used to interpret the influence of spaceflight on mammalian vestibular maculas in a model system, that of the adult Sprague-Dawley rat. More than twenty 3-D reconstructions of type I and type II hair cells and their afferents have been completed by digitization of contours traced from serial sections photographed in a transmission electron microscope. This labor-intensive method has now been replace d by a semiautomated method developed in the Biocomputation Center in which conventional photography is eliminated. All viewing, storage and manipulation of original data is done using Silicon Graphics workstations. Recent improvements to the software include a new mesh generation method for connecting contours. This method will permit the investigator to describe any surface, regardless of complexity, including highly branched structures such as are routinely found in neurons. This same mesh can be used for 3-D, finite volume simulation of synapse activation and voltage spread on neuronal surfaces visualized via the reconstruction process. These simulations help the investigator interpret the relationship between neuroarchitecture and physiology, and are of assistance in determining which experiments will best test theoretical interpretations. Data are also used to develop abstract, 3-D models that dynamically display neuronal activity ongoing in the system. Finally, the same data can be used to visualize the neural tissue in a virtual environment. Our exhibit will depict capabilities of our computational approaches and some of our findings from their application. For example, our research has demonstrated that maculas of adult mammals retain the property of synaptic plasticity. Ribbon synapses increase numerically and undergo changes in type and distribution (p<0.0001) in type II hair cells after exposure to microgravity for as few as nine days. The finding of macular synaptic plasticity is pertinent to the clinic, and may help explain some. balance disorders in humans. The software used in our investigations will be demonstrated for those interested in applying it in their own research.

  19. Computational Approaches to Vestibular Research

    Science.gov (United States)

    Ross, Muriel D.; Wade, Charles E. (Technical Monitor)

    1994-01-01

    The Biocomputation Center at NASA Ames Research Center is dedicated to a union between computational, experimental and theoretical approaches to the study of neuroscience and of life sciences in general. The current emphasis is on computer reconstruction and visualization of vestibular macular architecture in three-dimensions (3-D), and on mathematical modeling and computer simulation of neural activity in the functioning system. Our methods are being used to interpret the influence of spaceflight on mammalian vestibular maculas in a model system, that of the adult Sprague-Dawley rat. More than twenty 3-D reconstructions of type I and type II hair cells and their afferents have been completed by digitization of contours traced from serial sections photographed in a transmission electron microscope. This labor-intensive method has now been replace d by a semiautomated method developed in the Biocomputation Center in which conventional photography is eliminated. All viewing, storage and manipulation of original data is done using Silicon Graphics workstations. Recent improvements to the software include a new mesh generation method for connecting contours. This method will permit the investigator to describe any surface, regardless of complexity, including highly branched structures such as are routinely found in neurons. This same mesh can be used for 3-D, finite volume simulation of synapse activation and voltage spread on neuronal surfaces visualized via the reconstruction process. These simulations help the investigator interpret the relationship between neuroarchitecture and physiology, and are of assistance in determining which experiments will best test theoretical interpretations. Data are also used to develop abstract, 3-D models that dynamically display neuronal activity ongoing in the system. Finally, the same data can be used to visualize the neural tissue in a virtual environment. Our exhibit will depict capabilities of our computational approaches and some of our findings from their application. For example, our research has demonstrated that maculas of adult mammals retain the property of synaptic plasticity. Ribbon synapses increase numerically and undergo changes in type and distribution (phair cells after exposure to microgravity for as few as nine days. The finding of macular synaptic plasticity is pertinent to the clinic, and may help explain some. balance disorders in humans. The software used in our investigations will be demonstrated for those interested in applying it in their own research.

  20. Computational Approaches to Vestibular Research

    Science.gov (United States)

    Ross, Muriel D.; Wade, Charles E. (Technical Monitor)

    1994-01-01

    The Biocomputation Center at NASA Ames Research Center is dedicated to a union between computational, experimental and theoretical approaches to the study of neuroscience and of life sciences in general. The current emphasis is on computer reconstruction and visualization of vestibular macular architecture in three-dimensions (3-D), and on mathematical modeling and computer simulation of neural activity in the functioning system. Our methods are being used to interpret the influence of spaceflight on mammalian vestibular maculas in a model system, that of the adult Sprague-Dawley rat. More than twenty 3-D reconstructions of type I and type II hair cells and their afferents have been completed by digitization of contours traced from serial sections photographed in a transmission electron microscope. This labor-intensive method has now been replace d by a semiautomated method developed in the Biocomputation Center in which conventional photography is eliminated. All viewing, storage and manipulation of original data is done using Silicon Graphics workstations. Recent improvements to the software include a new mesh generation method for connecting contours. This method will permit the investigator to describe any surface, regardless of complexity, including highly branched structures such as are routinely found in neurons. This same mesh can be used for 3-D, finite volume simulation of synapse activation and voltage spread on neuronal surfaces visualized via the reconstruction process. These simulations help the investigator interpret the relationship between neuroarchitecture and physiology, and are of assistance in determining which experiments will best test theoretical interpretations. Data are also used to develop abstract, 3-D models that dynamically display neuronal activity ongoing in the system. Finally, the same data can be used to visualize the neural tissue in a virtual environment. Our exhibit will depict capabilities of our computational approaches and some of our findings from their application. For example, our research has demonstrated that maculas of adult mammals retain the property of synaptic plasticity. Ribbon synapses increase numerically and undergo changes in type and distribution (pclinic, and may help explain some. balance disorders in humans. The software used in our investigations will be demonstrated for those interested in applying it in their own research.

  1. Familial congenital vestibular areflexia.

    OpenAIRE

    Verhagen, W.I.; Huygen, P L; Horstink, M W

    1987-01-01

    Three cases in one family are presented with oscillopsia due to vestibular areflexia, but without hearing loss. There was no history of other neurological or otological diseases (including infectious diseases) or use of neuro-ototoxic drugs. Laboratory tests, including tests for autoimmune diseases, were undisturbed. Petrosal radiographs and brain CT scans were normal. The pedigree suggested autosomal recessive inheritance.

  2. Vestibular Schwannoma (Acoustic Neuroma) and Neurofibromatosis

    Science.gov (United States)

    ... Health Info » Hearing, Ear Infections, and Deafness Vestibular Schwannoma (Acoustic Neuroma) and Neurofibromatosis On this page: What ... I get additional information? What is a vestibular schwannoma (acoustic neuroma)? A vestibular schwannoma (also known as ...

  3. Audiologic diagnostics of vestibular schwannoma

    Directory of Open Access Journals (Sweden)

    Komazec Zoran

    2004-01-01

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

  4. Neuropharmacology of Vestibular System Disorders

    OpenAIRE

    Soto, Enrique; Vega, Rosario

    2010-01-01

    This work reviews the neuropharmacology of the vestibular system, with an emphasis on the mechanism of action of drugs used in the treatment of vestibular disorders. Otolaryngologists are confronted with a rapidly changing field in which advances in the knowledge of ionic channel function and synaptic transmission mechanisms have led to the development of new scientific models for the understanding of vestibular dysfunction and its management. In particular, there have been recent advances in...

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

    Directory of Open Access Journals (Sweden)

    Fred W Mast

    2014-05-01

    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.

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

    Science.gov (United States)

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

    1999-01-01

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

  7. Aging in the vestibular nuclear complex of the male golden hamster (Mesocricetus auratus): anatomic and morphometric study.

    Science.gov (United States)

    Fernández, J A; Suárez, C; Navarro, A; Díaz, C; Alvarez, J C; González del Rey, C; Tolivia, J

    2007-08-01

    To study the effects of senescence on the vestibular nuclear complex twenty brainstems from male golden hamsters between 3 and 27 months-old were used and the possible variations in the number of neurons, neuronal morphology and nuclear volume were studied. The neuron profiles were drawn with a camera lucida and Abercrombie's method was used to estimate the total number of neurons. The test of Kolmogorov-Smirnov with the correction of Lilliefors was used to evaluate the fit of our data to a normal distribution and a regression analysis was done to decide if the variation of our data with age was statistically significant. The results of the present study are relevant only for male animals and the effect of senescence could be different in female vestibular nuclear complex. Aging affects the volume of the superior and lateral vestibular nuclei, as well as the nuclear neuronal diameter of the medial vestibular nucleus, but no significant neuronal loss has been appreciated in vestibular nuclear complex related with age. During the aging process we have observed that the distribution of neurons within the vestibular nuclei of the golden hamster does not show important changes and most of their morphometric parameters do not vary significantly. PMID:17503342

  8. Incomplete segregation of endorgan-specific vestibular ganglion cells in mice and rats

    Science.gov (United States)

    Maklad, A.; Fritzsch, B.

    1999-01-01

    The endorgan-specific distribution of vestibular ganglion cells was studied in neonatal and postnatal rats and mice using indocarbocyanine dye (DiI) and dextran amines for retrograde and anterograde labeling. Retrograde DiI tracing from the anterior vertical canal labeled neurons scattered throughout the whole superior vestibular ganglion, with denser labeling at the dorsal and central regions. Horizontal canal neurons were scattered along the dorsoventral axis with more clustering toward the dorsal and ventral poles of this axis. Utricular ganglion cells occupied predominantly the central region of the superior vestibular ganglion. This utricular population overlapped with both the anterior vertical and horizontal canals' ganglion cells. Posterior vertical canal neurons were clustered in the posterior part of the inferior vestibular ganglion. The saccular neurons were distributed in the two parts of the vestibular ganglion, the superior and inferior ganglia. Within the inferior ganglion, the saccular neurons were clustered in the anterior part. In the superior ganglion, the saccular neurons were widely scattered throughout the whole ganglion with more numerous neurons at the posterior half. Small and large neurons were labeled from all endorgans. Examination of the fiber trajectory within the superior division of the vestibular nerve showed no clear lamination of the fibers innervating the different endorgans. These results demonstrate an overlapping pattern between the different populations within the superior ganglion, while in the inferior ganglion, the posterior canal and saccular neurons show tighter clustering but incomplete segregation. This distribution implies that the ganglion cells are assigned for their target during development in a stochastic rather than topographical fashion.

  9. True incidence of vestibular schwannoma?

    DEFF Research Database (Denmark)

    Stangerup, Sven-Eric; Tos, Mirko; Thomsen, Jens; Caye-Thomasen, Per

    2010-01-01

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

  10. Hypervascular vestibular Schwannoma: A case report

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-11-15

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

  11. Hypervascular vestibular Schwannoma: A case report

    International Nuclear Information System (INIS)

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

  12. Input/output properties of the lateral vestibular nucleus

    Science.gov (United States)

    Boyle, R.; Bush, G.; Ehsanian, R.

    2004-01-01

    This article is a review of work in three species, squirrel monkey, cat, and rat studying the inputs and outputs from the lateral vestibular nucleus (LVN). Different electrophysiological shock paradigms were used to determine the synaptic inputs derived from thick to thin diameter vestibular nerve afferents. Angular and linear mechanical stimulations were used to activate and study the combined and individual contribution of inner ear organs and neck afferents. The spatio-temporal properties of LVN neurons in the decerebrated rat were studied in response to dynamic acceleration inputs using sinusoidal linear translation in the horizontal head plane. Outputs were evaluated using antidromic identification techniques and identified LVN neurons were intracellularly injected with biocytin and their morphology studied.

  13. Enlarged Vestibular Aqueduct Syndrome (EVAS)

    Science.gov (United States)

    ... Canal Dehiscence (SCD) Tinnitus Vestibular Hyperacusis Vision & Hearing Psychology Diet Other Topics Military Resources Infographics & Presentations Paid ... People with EVA are cautioned to avoid contact sports and wear a helmet while bicycling or performing ...

  14. Stereotactic radiotherapy for vestibular schwannoma

    DEFF Research Database (Denmark)

    Muzevic, Dario; Legcevic, Jelena; Splavski, Bruno; Cayé-Thomasen, Per

    2014-01-01

    BACKGROUND: Vestibular schwannomas (acoustic neuromas) are common benign tumours that arise from the Schwann cells of the vestibular nerve. Management options include observation with neuroradiological follow-up, microsurgical resection and stereotactic radiotherapy. OBJECTIVES: To assess the...... effect of stereotactic radiotherapy compared to observation, microsurgical resection, any other treatment modality, or a combination of two or more of the above approaches for vestibular schwannoma. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials; PubMed; EMBASE; CINAHL...... resection or any other possible treatment or combination of treatments in patients with a cerebellopontine angle tumour up to 3 cm in diameter, presumed to be a vestibular schwannoma. DATA COLLECTION AND ANALYSIS: We used the standard methodological procedures expected by The Cochrane Collaboration. MAIN...

  15. Atypical Manifestation of Vestibular Schwannoma

    Directory of Open Access Journals (Sweden)

    Webster, Guilherme

    2013-09-01

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

  16. Aging in the vestibular nuclear complex of the male golden hamster (Mesocricetus auratus): anatomic and morphometric study

    OpenAIRE

    Fernández, J.A.; Suárez, C; Navarro, A.(fotógrafo); Díaz, C.; Alvarez, J C; González del Rey, C.; Tolivia, J. (Jorge)

    2007-01-01

    To study the effects of senescence on the vestibular nuclear complex twenty brainstems from male golden hamsters between 3 and 27 months-old were used and the possible variations in the number of neurons, neuronal morphology and nuclear volume were studied. The neuron profiles were drawn with a camera lucida and Abercrombie's method was used to estimate the total number of neurons. The test of Kolmogorov-Smirnov with the correction of Lilliefors was used to evaluate th...

  17. Enlarged Vestibular Aqueducts and Childhood Hearing Loss

    Science.gov (United States)

    ... EVA and Hearing Loss Otosclerosis Pendred Syndrome Vestibular Schwannoma (Acoustic Neuroma) and Neurofibromatosis Why NIDCD Does Research: ... inner ear: Researchers discover new mechanism of vestibular schwannoma that causes hearing loss, introduce new direction for ...

  18. Differential diagnosis and treatment of vestibular vertigo

    Directory of Open Access Journals (Sweden)

    Vladimir Anatolyevich Parfenov

    2010-06-01

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

  19. Radiosurgery for vestibular schwannomas

    Directory of Open Access Journals (Sweden)

    Sumit Sinha

    2014-01-01

    Full Text Available Vestibular schwannomas (VS are benign tumours arising from the 8 th cranial nerve. There are various treatment options for these tumours, which depend upon the tumour size and patient age. However, the surgical treatment has been the conventional method of management of these tumours, since they are frequently detected when quite large in size, especially in our country. Gamma knife radiosurgery (GKRS is frequently reserved for young patients with small and medium-sized VS (<3 cm and few symptoms. The tumour control dose is the most important consideration in GKRS, with higher doses having a risk for cranial nerve palsies, whereas lower doses leading to non-treatment of the tumour. The accepted tumour control dose ranges from 12 to 16 Gy among the various series with the tumour control rates of from 87% to 98% considered generally acceptable. The preservation of hearing is an issue worthwhile to be taken into account in GKRS and various series reporting this to range from 40% to 80%. The comparison between microsurgery and GKRS is still debatable because of different indications for both forms of therapies. Microsurgery is chosen for large tumours and GKRS for relatively smaller tumours.

  20. Compensation following bilateral vestibular damage

    Directory of Open Access Journals (Sweden)

    BillJYates

    2011-12-01

    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.

  1. Habituation of vestibular responses: An overview

    Science.gov (United States)

    Collins, W. E.

    1973-01-01

    An historical survey of vestibular habituation experiments has been undertaken. Methodological problems are presented briefly, and the influence of arousal on vestibular responses is detailed. Data obtained from animals and from man are treated separately. At least for man, the term habituation may be better defined by a dynamic change in the form of vestibular responses than by a simple response reduction.

  2. Vestibular stimulation by magnetic fields.

    Science.gov (United States)

    Ward, Bryan K; Roberts, Dale C; Della Santina, Charles C; Carey, John P; Zee, David S

    2015-04-01

    Individuals working next to strong static magnetic fields occasionally report disorientation and vertigo. With the increasing strength of magnetic fields used for magnetic resonance imaging studies, these reports have become more common. It was recently learned that humans, mice, and zebrafish all demonstrate behaviors consistent with constant peripheral vestibular stimulation while inside a strong, static magnetic field. The proposed mechanism for this effect involves a Lorentz force resulting from the interaction of a strong static magnetic field with naturally occurring ionic currents flowing through the inner ear endolymph into vestibular hair cells. The resulting force within the endolymph is strong enough to displace the lateral semicircular canal cupula, inducing vertigo and the horizontal nystagmus seen in normal mice and in humans. This review explores the evidence for interactions of magnetic fields with the vestibular system. PMID:25735662

  3. Vestibular afferent responses to microrotational stimuli

    Science.gov (United States)

    Myers, Steven F.; Lewis, Edwin R.

    1991-01-01

    Intracellular microelectrode recording/labeling techniques were used to investigate vestibular afferent responses in the bullfrog, to very small amplitude (less than 5 deg p-p) sinusoidal rotations in the vertical plane over the frequency range of 0.063-4 Hz. Robust responses to peak accelerations as low as 0.031 deg/sec per sec were obtained from units subsequently traced to either the central portion of the anterior canal crista or the striolar region of the utricle. All of these microrotationally sensitive afferent neurons had irregular resting discharge rates, and the majority had transfer ratios (relative to rotational velocity) of 1-40 spikes/sec per deg/sec. Individual utricular afferent velocity transfer ratios were nearly constant over the frequency range of 0.125-4 Hz. Canal units displayed decreasing response transfer ratios as stimulus frequencies increased. These findings indicate that, although utricular striolar and central crista afferent velocity transfer ratios to microrotations were very similar, utricular striolar afferent neurons were more faithful sensors of very small amplitude rotational velocity in the vertical plane.

  4. The vestibular implant: Quo vadis?

    Directory of Open Access Journals (Sweden)

    RaymondVan De Berg

    2011-08-01

    Study selection: all studies about the vestibular implant and related topics were included and evaluated by two reviewers. No study was excluded since every study investigated different aspects of the vestibular implant. Data extraction and synthesis: data was extracted by the first author from selected reports, supplemented by additional information, medical books conference lectures. Since each study had its own point of interest with its own outcomes, it was not possible to compare data of different studies. Conclusion: to use a basic vestibular implant in humans seems feasible in the very near future. Investigations show that electric stimulation of the canal nerves induces a nystagmus which corresponds to the plane of the canal which is innervated by the stimulated nerve branch. The brain is able to adapt to a higher baseline stimulation, while still reacting on a dynamic component. The best response will be achieved by a combination of the optimal stimulus (stimulus profile, stimulus location, precompensation, complemented by central vestibular adaptation. The degree of response will probably vary between individuals, depending on pathology and their ability to adapt.

  5. Perspectival Structure and Vestibular Processing

    DEFF Research Database (Denmark)

    Alsmith, Adrian John Tetteh

    2015-01-01

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

  6. Vestibular Findings in Military Band Musicians

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    Zeigelboim, Bianca Simone

    2014-04-01

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

  7. Human visual and vestibular heading perception in the vertical planes.

    Science.gov (United States)

    Crane, Benjamin T

    2014-02-01

    Heading estimation has not previously been reported in the vertical planes. This is a potentially interesting issue because although distribution of neuronal direction sensitivities is near uniform for vertical headings, there is an overrepresentation of otolith organs sensitive to motion in the horizontal relative to the vertical plane. Furthermore, thresholds of horizontal motion perception are considerably lower than those of vertical motion which has the potential to bias heading perception. The current data from 14 human subjects (age 19 to 67) measured heading estimation in response to vestibular motion of 14 cm (28 cm/s) over a 360° of headings at 5° intervals. An analogous visual motion was tested in separate trials. In this study, earth and head vertical/horizontal were always aligned. Results demonstrated that the horizontal component of heading was overestimated relative to the vertical component for vestibular heading stimuli in the coronal (skew) and sagittal (elevation) planes. For visual headings, the bias was much smaller and in the opposite direction such that the vertical component of heading was overestimated. Subjects older than 50 had significantly worse precision and larger biases relative to that of younger subjects for the vestibular conditions, although visual heading estimates were similar. A vector addition model was fit to the data which explains the observed heading biases by the known distribution of otolith organs in humans. The greatly decreased precision with age is explained by the model with decreases in end organ numbers, and relatively greater loss of otoliths that are sensitive to vertical motion. PMID:24249574

  8. Evaluation of cochleo-vestibular functions in patients with auditory neuropathy

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    Namea M. Ismail

    2014-07-01

    Conclusion: Patients with auditory neuropathy could also have vestibular neuropathy. Vestibular neuropathy could be classified into three groups: superior vestibular neuropathy, inferior vestibular neuropathy and superior/inferior vestibular neuropathy.

  9. Visual mental imagery during caloric vestibular stimulation

    OpenAIRE

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

    2006-01-01

    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...

  10. [Spectrum analysis of vestibular nystagmus].

    Science.gov (United States)

    Telezhnikov, A V; Bazarov, V G; Savchuk, L A; Beliakova, I A; Kaduk, V G

    1989-01-01

    A procedure for the spectral analysis of nystagmograms obtained by rotary stimulation with the rate of 180 degrees/s for 20 s has been developed with the aim to reveal the most typical changes in the vestibular nystagmus with one or another form of the cochleovestibular pathology. A signal recorded in the analogous form was processed by computer EC-1022. Periodograms were calculated by the method of the fast Fourier transform and periodogram smoothing by averaging of realization sites. In case of Ménière's disease the third harmonic was not recorded on periodograms when right and left labyrinths were stimulated and in the case of neurites of acoustic nerves, the third or fifth harmonic was not observed. A supposition is advanced that the third harmonic reflects the state of the peripheral area of the vestibular analyzer, while the fifth harmonic--the central one. PMID:2785934

  11. Changing perspective: The role of vestibular signals.

    Science.gov (United States)

    Deroualle, Diane; Borel, Liliane; Devèze, Arnaud; Lopez, Christophe

    2015-12-01

    Social interactions depend on mechanisms such as the ability to take another person's viewpoint, i.e. visuo-spatial perspective taking. However, little is known about the sensorimotor mechanisms underpinning perspective taking. Because vestibular signals play roles in mental rotation and spatial cognition tasks and because damage to the vestibular cortex can disturb egocentric perspective, vestibular signals stand as important candidates for the sensorimotor foundations of perspective taking. Yet, no study merged natural full-body vestibular stimulations and explicit visuo-spatial perspective taking tasks in virtual environments. In Experiment 1, we combined natural vestibular stimulation on a rotatory chair with virtual reality to test how vestibular signals are processed to simulate the viewpoint of a distant avatar. While they were rotated, participants tossed a ball to a virtual character from the viewpoint of a distant avatar. Our results showed that vestibular signals influence perspective taking in a direction-specific way: participants were faster when their physical body rotated in the same direction as the mental rotation needed to take the avatar's viewpoint. In Experiment 2, participants realized 3D object mental rotations, which did not involve perspective taking, during the same whole-body vestibular stimulation. Our results demonstrated that vestibular stimulation did not affect 3D object mental rotations. Altogether, these data indicate that vestibular signals have a direction-specific influence on visuo-spatial perspective taking (self-centered mental imagery), but not a general effect on mental imagery. Findings from this study suggest that vestibular signals contribute to one of the most crucial mechanisms of social cognition: understanding others' actions. PMID:26311354

  12. Epidemiology and natural history of vestibular schwannomas

    DEFF Research Database (Denmark)

    Stangerup, Sven-Eric; Caye-Thomasen, Per

    2012-01-01

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

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

    Science.gov (United States)

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

    2004-01-01

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

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

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    Cibele Brugnera

    2015-12-01

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

  15. Special (vestibular training of servicemen

    Directory of Open Access Journals (Sweden)

    Afonin V.M.

    2011-02-01

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

  16. BRN 3.1 Knockouts Affect the Vestibular, Autonomic, and Circadian Rhythm Responses to 2G Exposure

    Science.gov (United States)

    Murakami, D. M.; Erkman, L.; Rosenfeld, M. G.; Fuller, C. A.

    1999-01-01

    Our previous studies have demonstrated that 2G exposure via centrifugation significantly attenuated the daily mean and circadian rhythm amplitude of rat body temperature (Tb), heart rate, and activity (Act). In addition, 2G exposure activates neural responses in several vestibular, autonomic, and circadian nuclei. Although we have characterized the effect of 2G on an animal's physiological, neuronal, and behavioral responses, it will be important to understand the underlying neural and physiological mechanisms that mediate those responses. For example, the vestibular responses, proprioceptive feedback, or fluid shifts may be the critical factors that mediate the responses to 2G. As a first step to understand the relative importance of these different response pathways to altered gravitational fields, this study examined the contribution of the vestibular system by utilizing an animal model from molecular biology. Brain 3.1 (Bm 3.1) is a POU domain homeobox gene involved in the normal development of the vestibular and auditory system. Brn 3.1 deletion results in a loss of hair cells in the otoliths, semicircular canals, and cochlea. As a result mice with a Brn 3.1 deletion do not have a functioning vestibular or auditory system. The BRN 3.1 knockout mouse could be a very useful animal model for isolating the role of the vestibular system in mediating the physiological responses to 2G exposure. Therefore, this study compared the effect of 2G exposure via centrifugation between Brn 3.1 knockout (KO) versus Wildtype (W) mice.

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

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    Fabiane Paulin

    2009-01-01

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

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

    Science.gov (United States)

    Fridman, Gene Y; Della Santina, Charles C

    2012-11-01

    This article reviews vestibular pathology and the requirements and progress made in the design and construction of a vestibular prosthesis. Bilateral loss of vestibular sensation is disabling. When vestibular hair cells are injured by ototoxic medications or other insults to the labyrinth, the resulting loss of sensory input disrupts vestibulo-ocular reflexes (VORs) and vestibulo-spinal reflexes that normally stabilize the eyes and body. Affected individuals suffer poor vision during head movement, postural instability, chronic disequilibrium, and cognitive distraction. Although most individuals with residual sensation compensate for their loss over time, others fail to do so and have no adequate treatment options. A vestibular prosthesis analogous to cochlear implants but designed to modulate vestibular nerve activity during head movement should improve quality of life for these chronically dizzy individuals. We describe the impact of bilateral loss of vestibular sensation, animal studies supporting feasibility of prosthetic vestibular stimulation, the current status of multichannel vestibular sensory replacement prosthesis development, and challenges to successfully realizing this approach in clinical practice. In bilaterally vestibular-deficient rodents and rhesus monkeys, the Johns Hopkins multichannel vestibular prosthesis (MVP) partially restores the three-dimensional (3D) VOR for head rotations about any axis. Attempts at prosthetic vestibular stimulation of humans have not yet included the 3D eye movement assays necessary to accurately evaluate VOR alignment, but these initial forays have revealed responses that are otherwise comparable to observations in animals. Current efforts now focus on refining electrode design and surgical technique to enhance stimulus selectivity and preserve cochlear function, optimizing stimulus protocols to improve dynamic range and reduce excitation-inhibition asymmetry, and adapting laboratory MVP prototypes into devices appropriate for use in clinical trials. PMID:23044664

  19. Normal and abnormal human vestibular ocular function

    Science.gov (United States)

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

    1986-01-01

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

  20. Comparative gene expression study of the vestibular organ of the Igf1 deficient mouse using whole-transcript arrays.

    Science.gov (United States)

    Rodríguez-de la Rosa, Lourdes; Sánchez-Calderón, Hortensia; Contreras, Julio; Murillo-Cuesta, Silvia; Falagan, Sandra; Avendaño, Carlos; Dopazo, Joaquín; Varela-Nieto, Isabel; Milo, Marta

    2015-12-01

    The auditory and vestibular organs form the inner ear and have a common developmental origin. Insulin like growth factor 1 (IGF-1) has a central role in the development of the cochlea and maintenance of hearing. Its deficiency causes sensorineural hearing loss in man and mice. During chicken early development, IGF-1 modulates neurogenesis of the cochleovestibular ganglion but no further studies have been conducted to explore the potential role of IGF-1 in the vestibular system. In this study we have compared the whole transcriptome of the vestibular organ from wild type and Igf1(-/-) mice at different developmental and postnatal times. RNA was prepared from E18.5, P15 and P90 vestibular organs of Igf1(-/-) and Igf1(+/+) mice and the transcriptome analysed in triplicates using Affymetrix(®) Mouse Gene 1.1 ST Array Plates. These plates are whole-transcript arrays that include probes to measure both messenger (mRNA) and long intergenic non-coding RNA transcripts (lincRNA), with a coverage of over 28 thousand coding transcripts and over 7 thousands non-coding transcripts. Given the complexity of the data we used two different methods VSN-RMA and mmBGX to analyse and compare the data. This is to better evaluate the number of false positives and to quantify uncertainty of low signals. We identified a number of differentially expressed genes that we described using functional analysis and validated using RT-qPCR. The morphology of the vestibular organ did not show differences between genotypes and no evident alterations were observed in the vestibular sensory areas of the null mice. However, well-defined cellular alterations were found in the vestibular neurons with respect their number and size. Although these mice did not show a dramatic vestibular phenotype, we conducted a functional analysis on differentially expressed genes between genotypes and across time. This was with the aim to identify new pathways that are involved in the development of the vestibular organ as well as pathways that maybe affected by the lack of IGF-1 and be associated to the morphological changes of the vestibular neurons that we observed in the Igf1(-/-) mice. This article is part of a Special Issue entitled . PMID:26341476

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

    Directory of Open Access Journals (Sweden)

    JudithWagner

    2011-08-01

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

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

    Science.gov (United States)

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

    2013-01-01

    Vestibular compensation is the process of behavioral recovery following peripheral vestibular lesion. In clinics, the histaminergic medicine is the most widely prescribed for the treatment of vertigo and motion sickness, however, the molecular mechanisms by which histamine modulates vestibular function remain unclear. During recovery from the lesion, the modulation of histamine receptors in the medial vestibular nucleus (MVN) and the flocculus may play an important role. Here with the means of quantitative real-time PCR, western blotting and immunohistochemistry, we studied the expression of histamine receptors (H1, H2, and H3) in the bilateral MVN and the flocculus of rats on the 1st, 3rd, and 7th day following unilateral labyrinthectomy (UL). Our results have shown that on the ipsi-lesional flocculus the H1, H2 and H3 receptors mRNA and the protein increased significantly on the 1st and 3rd day, with compare of sham controls and as well the contralateral side of UL. However, on the 7th day after UL, this expression returned to basal levels. Furthermore, elevated mRNA and protein levels of H1, H2 and H3 receptors were observed in the ipsi-lesional MVN on the 1st day after UL compared with sham controls and as well the contralateral side of UL. However, this asymmetric expression was absent by the 3rd post-UL. Our findings suggest that the upregulation of histamine receptors in the MVN and the flocculus may contribute to rebalancing the spontaneous discharge in bilateral MVN neurons during vestibular compensation. PMID:23840519

  3. Dara vestibular equipment onboard MIR

    Science.gov (United States)

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

    We have described the vestibular and visuo-oculomotoric equipment which has been developed under various DARA contracts since 1991, and used aboard MIR in the frame of the following missions: • German MIR'92 mission (VOG) • Extensions to MIR '92, e.g. the use of VOG by V. Polyakov during his record stay in space from 1993 to 1994 • EUROMIR'94 (VOG) • EUROMIR'95 (VOG, OKS and BIVOG) • Joint German /Russian experiments in 1997/98 (BIVOG) The hardware is supplemented by various stimuli and measurements. New developments for a next generation BIVOG, which may become the Space Station 3D eye tracking system, have shortly been addressed.

  4. [Experimental study of vestibular neurectomy].

    Science.gov (United States)

    Pech, A; Cannoni, M; Appaix, M; Cahier, S; Lacour, M; Roll, J P

    1976-06-01

    The authors describe an experimental study carried out on baboons. After unilateral vestibular neurectomy, the behaviour disorders on the one hand, and on the other, modifications and temporal development of reflex muotatic excitability of the spine using Hoffmann's reflex method are analyzed. As far as behaviour is concerned, a four-day period of motor restriction following the operation causes more marked residual disorders in comparison with controls. From the neurophysiological point of view, neurectomy results in seriously disordered spinal reflexes characterized by ipsilateral hypo-excitability developing in there stages: a tw-day initial critical phase during which the disorders are at their worst, a four-day recuperative stage with partial regression of the disorders, finally a chronic compensation stage in which spinal excitability returns to normal after several months. PMID:825007

  5. Outcome analysis of individualized vestibular rehabilitation protocols

    Science.gov (United States)

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

    2000-01-01

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

  6. Unilateral vestibular loss impairs external space representation.

    Science.gov (United States)

    Borel, Liliane; Redon-Zouiteni, Christine; Cauvin, Pierre; Dumitrescu, Michel; Devèze, Arnaud; Magnan, Jacques; Péruch, Patrick

    2014-01-01

    The vestibular system is responsible for a wide range of postural and oculomotor functions and maintains an internal, updated representation of the position and movement of the head in space. In this study, we assessed whether unilateral vestibular loss affects external space representation. Patients with Menière's disease and healthy participants were instructed to point to memorized targets in near (peripersonal) and far (extrapersonal) spaces in the absence or presence of a visual background. These individuals were also required to estimate their body pointing direction. Menière's disease patients were tested before unilateral vestibular neurotomy and during the recovery period (one week and one month after the operation), and healthy participants were tested at similar times. Unilateral vestibular loss impaired the representation of both the external space and the body pointing direction: in the dark, the configuration of perceived targets was shifted toward the lesioned side and compressed toward the contralesioned hemifield, with higher pointing error in the near space. Performance varied according to the time elapsed after neurotomy: deficits were stronger during the early stages, while gradual compensation occurred subsequently. These findings provide the first demonstration of the critical role of vestibular signals in the representation of external space and of body pointing direction in the early stages after unilateral vestibular loss. PMID:24523916

  7. RECORDING OF VESTIBULAR EVOKED MYOGENIC POTENTIALS

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    A. A. Sazgar

    2006-05-01

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

  8. On the recall of vestibular sensations.

    Science.gov (United States)

    zu Eulenburg, Peter; Müller-Forell, W; Dieterich, M

    2013-01-01

    Functional neuroimaging studies on the recall or imagination of a distinctive task in the motor network or of sensations in sensory systems (visual, acoustic, nociceptive, gustatory, and olfactory) demonstrated that the respective primary cortex is often involved in the mental imagery process. Our aim was to examine this phenomenon in the vestibular system using fMRI. Sixteen healthy subjects were asked to remember the feeling of a rotatory chair procedure in contrast to an identical situation at rest. Shortly afterwards they were asked to recall the vestibular experience in a 1.5-T scanner. The resulting activations were then compared with the responses of a galvanic vestibular control experiment and a rest condition. The vestibular recall showed significant bihemispheric activations in the inferior frontal gyri, the anterior operculum, the middle cingulate, the putamen, the globus pallidus, the premotor motor cortex, and the anterior insula. We found activations in regions known to play a role in spatial referencing, motor programs, and attention in the recall of vestibular sensations. But important known relay stations for the cortical processing of vestibular information showed neither relevant activations nor deactivations. PMID:22367249

  9. Interactive Healthcare Systems in the Home: Vestibular Rehabilitation

    DEFF Research Database (Denmark)

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

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

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

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    Ariane Solci Bonucci

    2008-04-01

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

  11. Vestibular Rehabilitation for Peripheral Vestibular Hypofunction: An Evidence-Based Clinical Practice Guideline

    Science.gov (United States)

    Herdman, Susan J.; Whitney, Susan L.; Cass, Stephen P.; Clendaniel, Richard A.; Fife, Terry D.; Furman, Joseph M.; Getchius, Thomas S. D.; Goebel, Joel A.; Shepard, Neil T.; Woodhouse, Sheelah N.

    2016-01-01

    Background: Uncompensated vestibular hypofunction results in postural instability, visual blurring with head movement, and subjective complaints of dizziness and/or imbalance. We sought to answer the question, “Is vestibular exercise effective at enhancing recovery of function in people with peripheral (unilateral or bilateral) vestibular hypofunction?” Methods: A systematic review of the literature was performed in 5 databases published after 1985 and 5 additional sources for relevant publications were searched. Article types included meta-analyses, systematic reviews, randomized controlled trials, cohort studies, case control series, and case series for human subjects, published in English. One hundred thirty-five articles were identified as relevant to this clinical practice guideline. Results/Discussion: Based on strong evidence and a preponderance of benefit over harm, clinicians should offer vestibular rehabilitation to persons with unilateral and bilateral vestibular hypofunction with impairments and functional limitations related to the vestibular deficit. Based on strong evidence and a preponderance of harm over benefit, clinicians should not include voluntary saccadic or smooth-pursuit eye movements in isolation (ie, without head movement) as specific exercises for gaze stability. Based on moderate evidence, clinicians may offer specific exercise techniques to target identified impairments or functional limitations. Based on moderate evidence and in consideration of patient preference, clinicians may provide supervised vestibular rehabilitation. Based on expert opinion extrapolated from the evidence, clinicians may prescribe a minimum of 3 times per day for the performance of gaze stability exercises as 1 component of a home exercise program. Based on expert opinion extrapolated from the evidence (range of supervised visits: 2-38 weeks, mean = 10 weeks), clinicians may consider providing adequate supervised vestibular rehabilitation sessions for the patient to understand the goals of the program and how to manage and progress themselves independently. As a general guide, persons without significant comorbidities that affect mobility and with acute or subacute unilateral vestibular hypofunction may need once a week supervised sessions for 2 to 3 weeks; persons with chronic unilateral vestibular hypofunction may need once a week sessions for 4 to 6 weeks; and persons with bilateral vestibular hypofunction may need once a week sessions for 8 to 12 weeks. In addition to supervised sessions, patients are provided a daily home exercise program. Disclaimer: These recommendations are intended as a guide for physical therapists and clinicians to optimize rehabilitation outcomes for persons with peripheral vestibular hypofunction undergoing vestibular rehabilitation. Video Abstract available for more insights from the author (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A124). PMID:26913496

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

    Science.gov (United States)

    Maklad, Adel; Fritzsch, Bernd

    2002-01-01

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

  13. Tests of walking balance for screening vestibular disorders

    OpenAIRE

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

    2012-01-01

    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...

  14. Vestibular Schwannoma or acoustic neuroma

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    Hekmatara M

    1997-04-01

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

  15. Sensorial countermeasures for vestibular spatial disorientation.

    Science.gov (United States)

    Paillard, Aurore C; Quarck, Gaëlle; Denise, Pierre

    2014-05-01

    Spatial disorientation is defined as an erroneous body orientation perceived by pilots during flights. Limits of the vestibular system provoke frequent spatial disorientation mishaps. Although vestibular spatial disorientation is experienced frequently in aviation, there is no intuitive countermeasure against spatial disorientation mishaps to date. The aim of this review is to describe the current sensorial countermeasures and to examine future leads in sensorial ergonomics for vestibular spatial disorientation. This work reviews: 1) the visual ergonomics, 2) the vestibular countermeasures, 3) the auditory displays, 4) the somatosensory countermeasures, and, finally, 5) the multisensory displays. This review emphasizes the positive aspects of auditory and somatosensory countermeasures as well as multisensory devices. Even if some aspects such as sensory conflict and motion sickness need to be assessed, these countermeasures should be taken into consideration for ergonomics work in the future. However, a recent development in aviation might offer new and better perspectives: unmanned aerial vehicles. Unmanned aerial vehicles aim to go beyond the physiological boundaries of human sensorial systems and would allow for coping with spatial disorientation and motion sickness. Even if research is necessary to improve the interaction between machines and humans, this recent development might be incredibly useful for decreasing or even stopping vestibular spatial disorientation. PMID:24834571

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

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    Tihana Vešligaj

    2016-02-01

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

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

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    A.G. Pillay

    2000-01-01

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

  18. VESTIBULAR NASAL STENOSIS. A clinical case

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    A. Fernández Rodríguez

    2010-01-01

    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.

  19. Vestibular schwannoma: anatomical, medical and surgical perspective

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    Ashfaq Ul Hassan

    2013-06-01

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

  20. Outcome after translabyrinthine surgery for vestibular schwannomas

    DEFF Research Database (Denmark)

    Springborg, Jacob Bertram; Fugleholm, Kåre; Poulsgaard, Lars; Cayé-Thomasen, Per; Thomsen, Jens; Stangerup, Sven-Eric

    2012-01-01

    The objective of this article is to study the outcome after translabyrinthine surgery for vestibular schwannomas, with special focus on the facial nerve function. The study design is a case series from a national centralized database and it is set in two University Hospitals in Denmark. Participa......The objective of this article is to study the outcome after translabyrinthine surgery for vestibular schwannomas, with special focus on the facial nerve function. The study design is a case series from a national centralized database and it is set in two University Hospitals in Denmark...

  1. The nucleus of the optic tract. Its function in gaze stabilization and control of visual-vestibular interaction

    Science.gov (United States)

    Cohen, B.; Reisine, H.; Yokota, J. I.; Raphan, T.

    1992-01-01

    1. Electrical stimulation of the nucleus of the optic tract (NOT) induced nystagmus and after-nystagmus with ipsilateral slow phases. The velocity characteristics of the nystagmus were similar to those of the slow component of optokinetic nystagmus (OKN) and to optokinetic after-nystagmus (OKAN), both of which are produced by velocity storage in the vestibular system. When NOT was destroyed, these components disappeared. This indicates that velocity storage is activated from the visual system through NOT. 2. Velocity storage produces compensatory eye-in-head and head-on-body movements through the vestibular system. The association of NOT with velocity storage implies that NOT helps stabilize gaze in space during both passive motion and active locomotion in light with an angular component. It has been suggested that "vestibular-only" neurons in the vestibular nuclei play an important role in generation of velocity storage. Similarities between the rise and fall times of eye velocity during OKN and OKAN to firing rates of vestibular-only neurons suggest that these cells may receive their visual input through NOT. 3. One NOT was injected with muscimol, a GABAA agonist. Ipsilateral OKN and OKAN were lost, suggesting that GABA, which is an inhibitory transmitter in NOT, acts on projection pathways to the brain stem. A striking finding was that visual suppression and habituation of contralateral slow phases of vestibular nystagmus were also abolished after muscimol injection. The latter implies that NOT plays an important role in producing visual suppression of the VOR and habituating its time constant. 4. Habituation is lost after nodulus and uvula lesions and visual suppression after lesions of the flocculus and paraflocculus. We postulate that the disappearance of vestibular habituation and of visual suppression of vestibular responses after muscimol injections was due to dysfacilitation of the prominent NOT-inferior olive pathway, inactivating climbing fibers from the dorsal cap to nodulouvular and flocculoparafloccular Purkinje cells. The prompt loss of habituation when NOT was inactivated, and its return when the GABAergic inhibition dissipated, suggests that although VOR habituation can be relatively permanent, it must be maintained continuously by activity of the vestibulocerebellum.

  2. Vestibular migraine: diagnosis challenges and need for targeted treatment.

    Science.gov (United States)

    Barbosa, Felipe; Villa, Thaís Rodrigues

    2016-05-01

    Approximately 1% of the general population suffers from vestibular migraine. Despite the recently published diagnostic criteria, it is still underdiagnosed condition. The exact neural mechanisms of vestibular migraine are still unclear, but the variability of symptoms and clinical findings both during and between attacks suggests an important interaction between trigeminal and vestibular systems. Vestibular migraine often begins several years after typical migraine and has a variable clinical presentation. In vestibular migraine patients, the neurological and neurotological examination is mostly normal and the diagnosis will be based in the patient clinical history. Treatment trials that specialize on vestibular migraine are scarce and therapeutic recommendations are based on migraine guidelines. Controlled studies on the efficacy of pharmacologic interventions in the treatment of vestibular migraine should be performed. PMID:27191239

  3. Loss of Afferent Vestibular Input Produces Central Adaptation and Increased Gain of Vestibular Prosthetic Stimulation.

    Science.gov (United States)

    Phillips, Christopher; Shepherd, Sarah J; Nowack, Amy; Nie, Kaibao; Kaneko, Chris R S; Rubinstein, Jay T; Ling, Leo; Phillips, James O

    2016-02-01

    Implanted vestibular neurostimulators are effective in driving slow phase eye movements in monkeys and humans. Furthermore, increases in slow phase velocity and electrically evoked compound action potential (vECAP) amplitudes occur with increasing current amplitude of electrical stimulation. In intact monkeys, protracted intermittent stimulation continues to produce robust behavioral responses and preserved vECAPs. In lesioned monkeys, shorter duration studies show preserved but with somewhat lower or higher velocity behavioral responses. It has been proposed that such changes are due to central adaptive changes in the electrically elicited vestibulo-ocular reflex (VOR). It is equally possible that these differences are due to changes in the vestibular periphery in response to activation of the vestibular efferent system. In order to investigate the site of adaptive change in response to electrical stimulation, we performed transtympanic gentamicin perfusions to induce rapid changes in vestibular input in monkeys with long-standing stably functioning vestibular neurostimulators, disambiguating the effects of implantation from the effects of ototoxic lesion. Gentamicin injection was effective in producing a large reduction in natural VOR only when it was performed in the non-implanted ear, suggesting that the implanted ear contributed little to the natural rotational response before injection. Injection of the implanted ear produced a reduction in the vECAP responses in that ear, suggesting that the intact hair cells in the non-functional ipsilateral ear were successfully lesioned by gentamicin, reducing the efficacy of stimulation in that ear. Despite this, injection of both ears produced central plastic changes that resulted in a dramatically increased slow phase velocity nystagmus elicited by electrical stimulation. These results suggest that loss of vestibular afferent activity, and a concurrent loss of electrically elicited vestibular input, produces an increase in the efficacy of a vestibular neurostimulator by eliciting centrally adapted behavioral responses without concurrent adaptive increase of galvanic afferent activation in the periphery. PMID:26438271

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

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    Masoud Motasaddi Zarandy

    2011-12-01

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

  5. Response to Vestibular Sensory Events in Autism

    Science.gov (United States)

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

    2007-01-01

    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…

  6. Vestibular stimulation leads to distinct hemodynamic patterning

    Science.gov (United States)

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

    2000-01-01

    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 (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.

  7. Vesibulotoxicity and Management of Vestibular Disorders

    Science.gov (United States)

    Carey, John P.

    2005-01-01

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

  8. Vestibular effects on cerebral blood flow

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    Schlegel Todd T

    2009-09-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Cintia Ishii

    2009-06-01

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

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

    Scientific Electronic Library Online (English)

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

    2009-06-01

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

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

    Science.gov (United States)

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

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

  12. Exhibition of Stochastic Resonance in Vestibular Perception

    Science.gov (United States)

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

    2016-01-01

    Astronauts experience sensorimotor changes during spaceflight, particularly during G-transitions. Post flight sensorimotor changes include spatial disorientation, along with postural and gait instability that may degrade operational capabilities of the astronauts and endanger the crew. A sensorimotor countermeasure that mitigates these effects would improve crewmember safety and decrease risk. The goal of this research is to investigate the potential use of stochastic vestibular stimulation (SVS) as a technology to improve sensorimotor function. We hypothesize that low levels of SVS will improve sensorimotor perception through the phenomenon of stochastic resonance (SR), when the response of a nonlinear system to a weak input signal is enhanced by the application of a particular nonzero level of noise. This study aims to advance the development of SVS as a potential countermeasure by 1) demonstrating the exhibition of stochastic resonance in vestibular perception, a vital component of sensorimotor function, 2) investigating the repeatability of SR exhibition, and 3) determining the relative contribution of the semicircular canals (SCC) and otolith (OTO) organs to vestibular perceptual SR. A constant current stimulator was used to deliver bilateral bipolar SVS via electrodes placed on each of the mastoid processes, as previously done. Vestibular perceptual motion recognition thresholds were measured using a 6-degree of freedom MOOG platform and a 150 trial 3-down/1-up staircase procedure. In the first test session, we measured vestibular perceptual thresholds in upright roll-tilt at 0.2 Hz (SCC+OTO) with SVS ranging from 0-700 µA. In a second test session a week later, we re-measured roll-tilt thresholds with 0, optimal (from test session 1), and 1500 µA SVS levels. A subset of these subjects, plus naive subjects, participated in two additional test sessions in which we measured thresholds in supine roll-rotation at 0.2 Hz (SCC) and upright y-translation at 1 Hz (OTO) with SVS up to 700 µA. A sinusoidal galvanic vestibular stimulation (GVS) perceptual threshold was also measured on each test day and used to normalize the SVS levels across subjects. In roll-tilt thresholds with SVS, the characteristic SR curve was qualitatively exhibited in 10 of 12 subjects, and the improvement in motion threshold was significant in 6 subjects, indicating that optimal SVS improved passive body motion perception in a way that is consistent with classical SR theory. A probabilistic comparison to numeric simulations further validated these experimental results. On the second test session, 4 out of the 10 SR exhibitors showed repeated improvement with SVS compared to the no SVS condition. Data collection is ongoing for the last two test sessions in which SCC and OTO only perceptual motion recognition thresholds are being measured with SVS. The final results of these test sessions will give insight into whether vestibular perceptual SR can occur when only one type of vestibular sensor is sensing motion or if it is more evident when sensory integration between the SCC and OTO is occurring during the motion. The overall purpose of this research is to further quantify the effects of SVS on various sensorimotor tasks and to gain a more fundamental understanding of how SVS causes SR in the vestibular system. In the context of human space flight, results from this research will help in understanding how SVS may be practically implemented in the future as a component of a comprehensive countermeasure plan for G-transition adaptation.

  13. What is the most effective vestibular rehabilitation technique in patients with unilateral peripheral vestibular disorders?

    Science.gov (United States)

    Rossi-Izquierdo, Marcos; Santos-Pérez, Sofia; Soto-Varela, Andrés

    2011-11-01

    Vestibular rehabilitation has been found to be effective and safe in patients with instability. There is insufficient evidence, however, for distinguishing between the efficacies of different rehabilitation techniques. The objective of this study is to verify whether there are differences between two instrumental vestibular rehabilitation techniques, computerised dynamic posturography (CDP) and optokinetic stimulation (OKN), in order to establish the optimal strategy for each patient. We conducted a prospective, comparative study of the two techniques (CDP and OKN) in patients with instability due to chronic unilateral peripheral vestibular disorder. We randomly included 12 patients in each group, performing the evaluation with the Dizziness Handicap Inventory and the CDP with the sensorial organisation test (SOT), rhythmic weight shift and limits of stability (LOS). We found a statistically significant improvement in both groups in average balance score according to the SOT. In the OKN group, however, improvement was greater in visual preference. The CDP group showed greater benefits in the visual and vestibular input and LOS. Patients with poor vestibular and visual input or with reduced LOS will benefit more from an exercise protocol with CDP. Patients with poor visual preference, however, are ideal candidates for rehabilitation with OKN. PMID:21340557

  14. The Effects of Aging on Clinical Vestibular Evaluations

    OpenAIRE

    Maheu, Maxime; Houde, Marie-Soleil; Landry, Simon P.; Champoux, François

    2015-01-01

    Balance disorders are common issues for aging populations due to the effects of normal aging on peripheral vestibular structures. These changes affect the results of vestibular function evaluations and make the interpretation of these results more difficult. The objective of this article is to review the current state of knowledge of clinically relevant vestibular measures. We will first focus on otolith function assessment methods cervical-VEMP (cVEMP) and ocular-VEMP (oVEMP), then the calor...

  15. Kv1 channels and neural processing in vestibular calyx afferents

    OpenAIRE

    Meredith, Frances L.; Katherine J Rennie

    2015-01-01

    Potassium-selective ion channels are important for accurate transmission of signals from auditory and vestibular sensory end organs to their targets in the central nervous system. During different gravity conditions, astronauts experience altered input signals from the peripheral vestibular system resulting in sensorimotor dysfunction. Adaptation to altered sensory input occurs, but it is not explicitly known whether this involves synaptic modifications within the vestibular epithelia. Future...

  16. Purchase decision-making is modulated by vestibular stimulation

    OpenAIRE

    Preuss, Nora; Mast, Fred; HASLER, GREGOR

    2014-01-01

    Purchases are driven by consumers’ product preferences and price considerations. Using caloric vestibular stimulation (CVS), we investigated the role of vestibular-affective circuits in purchase decision-making. CVS is an effective noninvasive brain stimulation method, which activates vestibular and overlapping emotional circuits (e.g., the insular cortex and the anterior cingulate cortex (ACC)). Subjects were exposed to CVS and sham stimulation while they performed two purchase decision-maki...

  17. Purchase decision-making is modulated by vestibular stimulation

    OpenAIRE

    Nora Preuss; Gregor Hasler

    2014-01-01

    Purchases are driven by consumers’ product preferences and price considerations. Using caloric vestibular stimulation (CVS), we investigated the role of vestibular-affective circuits in purchase decision-making. CVS is an effective 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 tas...

  18. Interactions between stress and vestibular compensation – a review

    OpenAIRE

    MayankBDutia; YouganSaman; DorisBamiou

    2012-01-01

    Elevated levels of stress and anxiety often accompany vestibular dysfunction, while conversely complaints of dizziness and loss of balance are common in patients with panic and other anxiety disorders. The interactions between stress and vestibular function, and plasticity have been investigated both in animal models and in clinical studies. Evidence from animal studies indicates that vestibular symptoms are effective in activating the stress axis, and that the acute stress response is import...

  19. Doença vestibular em cães: 81 casos (2006-2013)

    OpenAIRE

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

    2014-01-01

    De 2006 a 2013 foram diagnosticados 81 casos de doença vestibular canina no serviço de rotina em neurologia de um hospital veterinário universitário do sul do Brasil. Desses, aproximadamente dois terços foram diagnosticados com doença vestibular central (DVC) e cerca de um terço como doença vestibular periférica (DVP). Cães com raça definida foram mais acometidos que aqueles sem raça definida, principalmente Dachshund (DVP) e Boxer (DVC). Os principais sinais clínicos observados, tanto na DVP...

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

    OpenAIRE

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

    1991-01-01

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

  1. Signal processing for a vestibular neurostimulator.

    Science.gov (United States)

    Rubinstein, Jay T; Nie, Kaibao; Bierer, Steven; Ling, Leo; Phillips, James O

    2010-01-01

    An implanted vestibular neurostimulator has been developed based on commercial cochlear implant technology. It has been implanted chronically in Rhesus monkeys and the physiology of electrical stimulation of the vestibular periphery has been studied. We are currently proposing a human feasibility study of implantation of the device for the treatment of incapacitating Meniere's disease. Because no animal model of Meniere's disease exists, signal processing for such a device must be based on prior observations of human subjects who have suffered Meniere's attacks while their eye-movements could be quantified. Based on such data, and on the leading theories for the pathophysiology of a Meniere's attack, our animal data suggests that fixed amplitude, constant frequency biphasic pulse trains should be adequate to suppress the symptoms of an attack when they occur. The intensity of the stimuli and efficacy of vertigo suppression should be readily modulated either by amplitude or frequency adjustments. PMID:21097347

  2. Clinical application of vestibular evoked myogenic potential (VEMP).

    Science.gov (United States)

    Murofushi, Toshihisa

    2016-08-01

    The author reviewed clinical aspects of vestibular evoked myogenic potentials (VEMPs). Now two types of VEMPs are available. The first one is cervical VEMP, which is recorded in the sternocleidomastoid muscle and predominantly reflects sacculo-collic reflex. The other is ocular VEMP, which is usually recorded below the lower eye lid and predominantly reflects utriculo-ocular reflex. VEMPs play important roles not only for assessment of common vestibular diseases but also for establishment of new clinical entities. Clinical application in Meniere's disease, vestibular neuritis, benign paroxysmal positional vertigo, vestibular migraine, idiopathic otolithic vertigo, and central vertigo/dizziness was reviewed. PMID:26791591

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

    Directory of Open Access Journals (Sweden)

    Zucca Gianpiero

    2009-06-01

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

  4. Repeat Gamma Knife surgery for vestibular schwannomas

    OpenAIRE

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

    2015-01-01

    Background: Gamma Knife (GK) surgery is a recognized treatment option for the management of small to medium-sized vestibular schwannoma (VS) associated with high-tumor control and low morbidity. When a radiosurgical treatment fails to stop tumor growth, repeat GK surgery can be proposed in selected cases. Methods : A series of 27 GK retreatments was performed in 25 patients with VS; 2 patients underwent three procedures. The median time interval between GK treatments was 45 months. The me...

  5. New Insights into Pathophysiology of Vestibular Migraine

    OpenAIRE

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

    2015-01-01

    Vestibular migraine (VM) is a common disorder in which genetic, epigenetic, and environmental factors probably contribute to its development. The pathophysiology of VM is unknown; nevertheless in the last few years, several studies are contributing to understand the neurophysiological pathways involved in VM. The current hypotheses are mostly based on the knowledge of migraine itself. The evidence of trigeminal innervation of the labyrinth vessels and the localization of vasoactive neuropepti...

  6. Complications of microsurgery of vestibular schwannoma

    Czech Academy of Sciences Publication Activity Database

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

    2014-01-01

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

  7. MRI in a quiescent vestibular schwannoma

    International Nuclear Information System (INIS)

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

  8. Causal links between MSTd neurons and multisensory heading perception

    OpenAIRE

    Gu, Yong; DeAngelis, Gregory C; ANGELAKI, DORA E.

    2012-01-01

    The dorsal medial superior temporal area (MSTd) in the extrastriate visual cortex is thought to play an important role in heading perception because neurons in this area are tuned to both optic flow and vestibular signals. MSTd neurons also show significant correlations with perceptual judgments during a fine heading direction discrimination task. To test for a causal link with heading perception, we used microstimulation and reversible inactivation techniques to artificially perturb MSTd act...

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

    Directory of Open Access Journals (Sweden)

    Bianca Simone Zeigelboim

    2010-01-01

    Full Text Available O objetivo desse estudo foi analisar a eficácia do exercício de reabilitação vestibular em dois casos de esclerose múltipla remitente-recorrente. Ambos os casos foram encaminhados do Hospital de Clínicas para o Laboratório de Otoneurologia de uma instituição de ensino e foram submetidos aos seguintes 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.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 following 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.

  10. Nitric oxide synthase and arginase expression changes in the rat perirhinal and entorhinal cortices following unilateral vestibular damage: a link to deficits in object recognition?

    Science.gov (United States)

    Liu, Ping; Gliddon, Catherine M; Lindsay, Libby; Darlington, Cynthia L; Smith, Paul F

    2004-01-01

    Previous studies have shown that peripheral vestibular damage causes long-term neurochemical changes in the hippocampus which may be related to spatial memory deficits. Since recent studies have also demonstrated deficits in non-spatial object recognition memory following vestibular lesions, the aim of the present study was to extend these investigations into the perirhinal cortex (PRC), which is known to be important for object recognition, and the related entorhinal cortex (EC). We examined the effects of unilateral vestibular deafferentation (UVD) on the expression of four enzymes associated with neuronal plasticity, neuronal nitric oxide synthase (nNOS), endothelial nitric oxide synthase (eNOS), arginase I and arginase II (AI and II), in the rat EC and PRC using Western blotting. Tissue was collected at 10 hs, 50 hs and 2 weeks post-UVD. In the EC and PRC, nNOS protein expression decreased on the contralateral side at 2 weeks post-UVD but not before. At the same time, eNOS protein expression increased in both regions on the contralateral side. In the EC, AII protein expression increased on the ipsilateral side at 2 weeks post-UVD. In the PRC, AI increased and decreased on the contralateral and ipsilateral sides (respectively) at 2 weeks post-UVD. AII showed a bilateral increase in the PRC at 2 weeks post-UVD. These results demonstrate changes in NOS and arginase protein expression in the PRC and EC following UVD, which are unlikely to be due to the initial severity of the vestibular syndrome because they develop well after vestibular compensation has taken place. Neurochemical changes in these regions of the medial temporal lobe may be implicated in the development of object recognition deficits that contribute to cognitive dysfunction following peripheral vestibular damage. PMID:15735325

  11. Secreted Factors from Human Vestibular Schwannomas Can Cause Cochlear Damage

    Science.gov (United States)

    Dilwali, Sonam; Landegger, Lukas D.; Soares, Vitor Y. R.; Deschler, Daniel G.; Stankovic, Konstantina M.

    2015-01-01

    Vestibular schwannomas (VSs) are the most common tumours of the cerebellopontine angle. Ninety-five percent of people with VS present with sensorineural hearing loss (SNHL); the mechanism of this SNHL is currently unknown. To establish the first model to study the role of VS-secreted factors in causing SNHL, murine cochlear explant cultures were treated with human tumour secretions from thirteen different unilateral, sporadic VSs of subjects demonstrating varied degrees of ipsilateral SNHL. The extent of cochlear explant damage due to secretion application roughly correlated with the subjects’ degree of SNHL. Secretions from tumours associated with most substantial SNHL resulted in most significant hair cell loss and neuronal fibre disorganization. Secretions from VSs associated with good hearing or from healthy human nerves led to either no effect or solely fibre disorganization. Our results are the first to demonstrate that secreted factors from VSs can lead to cochlear damage. Further, we identified tumour necrosis factor alpha (TNF?) as an ototoxic molecule and fibroblast growth factor 2 (FGF2) as an otoprotective molecule in VS secretions. Antibody-mediated TNF? neutralization in VS secretions partially prevented hair cell loss due to the secretions. Taken together, we have identified a new mechanism responsible for SNHL due to VSs. PMID:26690506

  12. A study of whirlin isoforms in the mouse vestibular system suggests potential vestibular dysfunction in DFNB31-deficient patients.

    Science.gov (United States)

    Mathur, Pranav Dinesh; Vijayakumar, Sarath; Vashist, Deepti; Jones, Sherri M; Jones, Timothy A; Yang, Jun

    2015-12-15

    The DFNB31 gene plays an indispensable role in the cochlea and retina. Mutations in this gene disrupt its various isoforms and lead to non-syndromic deafness, blindness and deaf-blindness. However, the known expression of Dfnb31, the mouse ortholog of DFNB31, in vestibular organs and the potential vestibular-deficient phenotype observed in one Dfnb31 mutant mouse (Dfnb31(wi/wi)) suggest that DFNB31 may also be important for vestibular function. In this study, we find that full-length (FL-) and C-terminal (C-) whirlin isoforms are expressed in the vestibular organs, where their stereociliary localizations are similar to those of developing cochlear inner hair cells. No whirlin is detected in Dfnb31(wi/wi) vestibular organs, while only C-whirlin is expressed in Dfnb31(neo/neo) vestibular organs. Both FL- and C-whirlin isoforms are required for normal vestibular stereociliary growth, although they may play slightly different roles in the central and peripheral zones of the crista ampullaris. Vestibular sensory-evoked potentials demonstrate severe to profound vestibular deficits in Dfnb31(neo/neo) and Dfnb31(wi/wi) mice. Swimming and rotarod tests demonstrate that the two Dfnb31 mutants have balance problems, with Dfnb31(wi/wi) mice being more affected than Dfnb31(neo/neo) mice. Because Dfnb31(wi/wi) and Dfnb31(neo/neo) mice faithfully recapitulate hearing and vision symptoms in patients, our findings of vestibular dysfunction in these Dfnb31 mutants raise the question of whether DFNB31-deficient patients may acquire vestibular as well as hearing and vision loss. PMID:26420843

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

    Directory of Open Access Journals (Sweden)

    Mercier Pierre

    2009-08-01

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

  14. Como o implante coclear pode interferir na função vestibular?

    Directory of Open Access Journals (Sweden)

    Abramides, Patricia Arena

    2009-06-01

    Full Text Available Introdução: O implante coclear é uma opção terapêutica para pacientes com surdez neurossensorial profunda. Alguns pacientes implantados evoluíam com tontura no pós-operatório, o que deu início ao interesse pela função vestibular. Desde então, muitos estudos relataram a associação entre o implante coclear e as disfunções vestibulares.

  15. Vestibular vertigo in emergency neurology and cervical osteochondrosis

    Directory of Open Access Journals (Sweden)

    T S Barykova

    2010-06-01

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

  16. Vestibular influences on autonomic cardiovascular control in humans

    Science.gov (United States)

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

    1998-01-01

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

  17. Long-term hearing preservation in vestibular schwannoma

    DEFF Research Database (Denmark)

    Stangerup, Sven-Eric; Thomsen, Jens; Tos, Mirko; Cayé-Thomasen, Per

    2010-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Joseph B

    2002-07-01

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

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

    Directory of Open Access Journals (Sweden)

    Rashid Al Abri

    2012-01-01

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

  20. Neural Network Model of Vestibular Nuclei Reaction to Onset of Vestibular Prosthetic Stimulation

    Science.gov (United States)

    DiGiovanna, Jack; Nguyen, T. A. K.; Guinand, Nils; Pérez-Fornos, Angelica; Micera, Silvestro

    2016-01-01

    The vestibular system incorporates multiple sensory pathways to provide crucial information about head and body motion. Damage to the semicircular canals, the peripheral vestibular organs that sense rotational velocities of the head, can severely degrade the ability to perform activities of daily life. Vestibular prosthetics address this problem by using stimulating electrodes that can trigger primary vestibular afferents to modulate their firing rates, thus encoding head movement. These prostheses have been demonstrated chronically in multiple animal models and acutely tested in short-duration trials within the clinic in humans. However, mainly, due to limited opportunities to fully characterize stimulation parameters, there is a lack of understanding of “optimal” stimulation configurations for humans. Here, we model possible adaptive plasticity in the vestibular pathway. Specifically, this model highlights the influence of adaptation of synaptic strengths and offsets in the vestibular nuclei to compensate for the initial activation of the prosthetic. By changing the synaptic strengths, the model is able to replicate the clinical observation that erroneous eye movements are attenuated within 30 minutes without any change to the prosthetic stimulation rate. Although our model was only built to match this time point, we further examined how it affected subsequent pulse rate modulation (PRM) and pulse amplitude modulation (PAM). PAM was more effective than PRM for nearly all stimulation configurations during these acute tests. Two non-intuitive relationships highlighted by our model explain this performance discrepancy. Specifically, the attenuation of synaptic strengths for afferents stimulated during baseline adaptation and the discontinuity between baseline and residual firing rates both disproportionally boost PAM. Comodulation of pulse rate and amplitude has been experimentally shown to induce both excitatory and inhibitory eye movements even at high baseline stimulation rates. We also modeled comodulation and found synergistic combinations of stimulation parameters to achieve equivalent output to only amplitude modulation. This may be an important strategy to reduce current spread and misalignment. The model outputs reflected observed trends in clinical testing and aspects of existing vestibular prosthetic literature. Importantly, the model provided insight to efficiently explore the stimulation parameter space, which was helpful, given limited available patient time. PMID:27148528

  1. Vestibular schwannoma with contralateral facial pain – case report

    Directory of Open Access Journals (Sweden)

    Ghodsi Mohammad

    2003-03-01

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

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

    Directory of Open Access Journals (Sweden)

    Karlstedt Kaj

    2004-09-01

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

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

    Science.gov (United States)

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

    2015-05-01

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

  4. Vestibular and oculomotor abnormalities in vertebrobasilar insufficiency.

    Science.gov (United States)

    Corvera, J; Benitez, L D; Lopez-Rios, G; Rabiela, M T

    1980-01-01

    The early diagnosis of vertebrobasilar insufficiency in patients with vertigo as their only symptom was attempted using a battery of vestibulo-oculomotor tests. With this testing procedure, we were able to find abnormal vestibulo-oculomotor mechanisms that could account for the vertigo in 41 of 42 patients. These abnormalities, however, did not fall into an easily recognizable pattern that could be considered characteristic of vertebrobasilar insufficiency. The large intersubject variability probably arises from the very different and widespread lesions that occur at the vestibular and neurological levels as a consequence of vertebrobasilar insufficiency. PMID:6968173

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

    OpenAIRE

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

    2010-01-01

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

  6. Effectiveness of vestibular exercise in acute vertigo

    International Nuclear Information System (INIS)

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

  7. STANDARDIZATION OF VESTIBULAR EVOKED MYOGENIC POTENTIALS

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    Ufuk Derinsu

    2009-01-01

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

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

    Scientific Electronic Library Online (English)

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

    2013-02-01

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

  9. Nystagmus in Enlarged Vestibular Aqueduct: A Case Series.

    Science.gov (United States)

    White, Judith; Krakovitz, Paul

    2015-01-21

    Enlarged vestibular aqueduct (EVA) is one of the commonly identified congenital temporal bone abnormalities associated with sensorineural hearing loss. Hearing loss may be unilateral or bilateral, and typically presents at birth or in early childhood. Vestibular symptoms have been reported in up to 50% of affected individuals, and may be delayed in onset until adulthood. The details of nystagmus in patients with EVA have not been previously reported. The objectives were to describe the clinical history, vestibular test findings and nystagmus seen in a case series of patients with enlarged vestibular aqueduct anomaly. Chart review, included computed tomography temporal bones, infrared nystagmography with positional and positioning testing, caloric testing, rotary chair and vibration testing. Clinical history and nystagmus varied among the five patients in this series. All patients were initially presumed to have benign paroxysmal positional vertigo, but repositioning treatments were not effective, prompting referral, further testing and evaluation. In three patients with longstanding vestibular complaints, positional nystagmus was consistently present. One patient had distinct recurrent severe episodes of positional nystagmus. Nystagmus was unidirectional and horizontal. In one case horizontal nystagmus was consistently reproducible with seated head turn to the affected side, and reached 48 d/s. Nystagmus associated with enlarged vestibular aqueduct is often positional, and can be confused with benign paroxysmal positional vertigo. Unexplained vestibular symptoms in patients with unilateral or bilateral sensorineural hearing loss should prompt diagnostic consideration of EVA. PMID:26557362

  10. Nystagmus in enlarged vestibular aqueduct: a case series

    Directory of Open Access Journals (Sweden)

    Judith White

    2015-03-01

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

  11. Vestibular contributions to a right-hemisphere network for bodily awareness: combining galvanic vestibular stimulation and the "Rubber Hand Illusion".

    Science.gov (United States)

    Ferrè, Elisa Raffaella; Berlot, Eva; Haggard, Patrick

    2015-03-01

    An altered sense of one's own body is a common consequence of vestibular damage, and also of damage to vestibular networks in the right hemisphere. However, few experimental studies have investigated whether vestibular signals contribute to bodily awareness. We addressed this issue by combining an established experimental model of bodily awareness (Rubber Hand Illusion -RHI) with galvanic vestibular stimulation (GVS) in healthy participants. Brief left anodal and right cathodal GVS (which predominantly activates vestibular networks in the right hemisphere), or right anodal and left cathodal GVS, or sham stimulation were delivered at random, while participants experienced either synchronous or asynchronous visuo-tactile stimulation of a rubber hand and their own hand. The drift in the perceived position of the participant's hand towards the rubber hand was used as a proxy measure of the resulting multisensory illusion of body ownership. GVS induced strong polarity-dependent effects on this measure of RHI: left anodal and right cathodal GVS produced significantly lower proprioceptive drift than right anodal and left cathodal GVS. We suggest that vestibular inputs influence the multisensory weighting functions that underlie bodily awareness: the right hemisphere vestibular projections activated by the left anodal and right cathodal GVS increased the weight of intrinsic proprioceptive signals about hand position, and decreased the weight of visual information responsible for visual capture during the RHI. PMID:25619847

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

    Directory of Open Access Journals (Sweden)

    RaymondVan De Berg

    2012-02-01

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

  13. Improved results for vestibular schwannoma radiosurgery

    International Nuclear Information System (INIS)

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

  14. Vestibular function and temporal bone imaging in DFNB1.

    Science.gov (United States)

    Oonk, A M M; Beynon, A J; Peters, T A; Kunst, H P M; Admiraal, R J C; Kremer, H; Verbist, B; Pennings, R J E

    2015-09-01

    DFNB1 is the most prevalent type of hereditary hearing impairment known nowadays and the audiometric phenotype is very heterogeneous. There is, however, no consensus in literature on vestibular and imaging characteristics. Vestibular function and imaging results of 44 DFNB1 patients were evaluated in this retrospective study. All patients displayed a response during rotational velocity step testing. In 65% of the cases, the caloric results were within normal range bilaterally. The video head impulse test was normal in all patients. In 34.4% of the CT scans one or more temporal bone anomalies were found. The various anomalies found, were present in small numbers and none seemed convincingly linked to a specific DFNB1genotype. The group of DFNB1 patients presented here is the largest thus far evaluated for their vestibular function. From this study, it can be assumed that DFNB1 is not associated with vestibular dysfunction or specific temporal bone anomalies. PMID:26188104

  15. Fractionated stereotactic radiotherapy of vestibular schwannomas accelerates hearing loss

    DEFF Research Database (Denmark)

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

    2012-01-01

    To evaluate long-term tumor control and hearing preservation rates in patients with vestibular schwannoma treated with fractionated stereotactic radiotherapy (FSRT), comparing hearing preservation rates to an untreated control group. The relationship between radiation dose to the cochlea and...

  16. Distinct spontaneous shrinkage of a sporadic vestibular schwannoma

    DEFF Research Database (Denmark)

    Huang, Xiaowen; Cayé-Thomasen, Per; Stangerup, Sven-Eric

    2013-01-01

    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...

  17. Caloric vestibular stimulation in aphasic syndrome

    Directory of Open Access Journals (Sweden)

    David Wilkinson

    2013-12-01

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

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

    Science.gov (United States)

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

    2001-01-01

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

  19. Posturografia em idosos com distúrbios vestibulares e quedas

    OpenAIRE

    Camila Macedo; Juliana Maria Gazzola; Heloisa Helena Caovilla; Natalia Aquaroni Ricci; Flávia Doná; Fernando Freitas Ganança

    2013-01-01

    Introdução: A posturografia estática e dinâmica tem sido usada para analisar a habilidade de idosos com disfunção vestibular em manter o equilíbrio corporal em diferentes condições de conflitos sensoriais. O objetivo do exame é quantificar a velocidade de oscilação e o deslocamento do centro de pressão nas condições de conflitos visual, somatossensorial e interação visuo-vestibular, e o limite de estabilidade. Objetivo: Analisar a literatura referente ao controle do equilíbrio corporal em ido...

  20. Using Galvanic Vestibular Stimulation to Sense Abstract Data

    OpenAIRE

    MÀki-Reinikka, Kasperi; Torniainen, Jari; Alafuzoff, Aleksander; Kotkanen, Henri; Toivanen, Jukka M.

    2013-01-01

    We propose using galvanic vestibular stimulation for presenting abstract data, for instance stock market trends. Using galvanic vestibular stimulation, data is felt directly as a perturbation in the sense of balance. This work is showcased as an art performance, where stock market fluctuations cause a person to maintain or lose balance. We present the artistic and technical principles underlying the performance and describe the technical implementation of a working system. The work shows how ...

  1. Vestibular evoked myogenic potential in sudden sensorineural hearing loss

    OpenAIRE

    Feroze Kancharu Khan; Achamma Balraj; Anjali Lepcha

    2013-01-01

    Aim and Objective: To investigate saccular damage in patients with sudden sensorineural hearing loss (SSNHL) with or without vertigo and to evaluate the saccular damage according to the hearing loss and presence or absence of vertigo. Materials and Methods: All tests done in this study were performed in the audio vestibular unit of ENT department from September 2009 to November 2010. Statistical Analysis Used: The association between the severity of hearing loss and changes in the vestibular ...

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

    International Nuclear Information System (INIS)

    Objective: In the last two decades, advances in the computerized tomography (CT) field revise the internal and medium ear evaluation. Therefore, the aim of this study is to analyze the morphology and morphometric aspects of the vestibular aqueduct on the basis of computerized tomography images (CTI). Material and method: Computerized tomography images of vestibular aqueducts were acquired from patients (n = 110) with an age range of 1-92 years. Thereafter, from the vestibular aqueducts images a morphometric analysis was performed. Through a computerized image processing system, the vestibular aqueduct measurements comprised of its area, external opening, length and the distance from the vestibular aqueduct to the internal acoustic meatus. Results: The morphology of the vestibular aqueduct may be funnel-shaped, filiform or tubular and the respective proportions were found to be at 44%, 33% and 22% in children and 21.7%, 53.3% and 25% in adults. The morphometric data showed to be of 4.86 mm2 of area, 2.24 mm of the external opening, 4.73 mm of length and 11.88 mm of the distance from the vestibular aqueduct to the internal acoustic meatus, in children, and in adults it was of 4.93 mm2, 2.09 mm, 4.44 mm, and 11.35 mm, respectively. Conclusions: Computerized tomography showed that the vestibular aqueduct presents high morphological variability. The morphometric analysis showed that the differences found between groups of children and adults or between groups of both genders were not statistically significant

  3. Vestibular function in families with inherited autosomal dominant hearing loss

    OpenAIRE

    Street, Valerie A.; Kallman, Jeremy C.; Strombom, Paul D.; Bramhall, Naomi F; Phillips, James O.

    2008-01-01

    The inner ear contains the developmentally related cochlea and peripheral vestibular labyrinth. Given the similar physiology between these two organs, hearing loss and vestibular dysfunction may be expected to occur simultaneously in individuals segregating mutations in inner ear genes. Twenty-two different genes have been discovered that when mutated lead to non-syndromic autosomal dominant hearing loss. A review of the literature indicates that families segregating mutations in 13 of these ...

  4. Nystagmus in Enlarged Vestibular Aqueduct: A Case Series

    OpenAIRE

    Judith White; Paul Krakovitz

    2015-01-01

    Enlarged vestibular aqueduct (EVA) is one of the commonly identified congenital temporal bone abnormalities associated with sensorineural hearing loss. Hearing loss may be unilateral or bilateral, and typically presents at birth or in early childhood. Vestibular symptoms have been reported in up to 50% of affected individuals, and may be delayed in onset until adulthood. The details of nystagmus in patients with EVA have not been previously reported. The objectives were to describe the clinic...

  5. Eye position dependency of nystagmus during constant vestibular stimulation.

    OpenAIRE

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

    2013-01-01

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

  6. Metachronous schwannoma in the colon with vestibular schwannoma

    OpenAIRE

    Jung, Eun-Joo; Han, Hye Seung; Koh, Young-Cho; Cho, Joon; Ryu, Chun-Geun; Paik, Jin Hee; Hwang, Dae-Yong

    2014-01-01

    We experienced a case of vestibular schwannoma and metachronous schwannoma in the colon. A 59-year-old female presented with a 1-month history of hematochezia. She had undergone suboccipital craniectomy resulting in radical subtotal resection, followed by gamma knife radiosurgery for a large left vestibular schwannoma 4 years prior to admission. On preoperative colonoscopy, a huge mass through which the colonoscope could not be passed was detected. CT scans showed colo-colonic intussusception...

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

    Science.gov (United States)

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

    1995-01-01

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

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

    Science.gov (United States)

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

    2015-07-01

    Vestibular schwannomas, also known as acoustic neuromas, are benign tumors, which originate from myelin-forming Schwann cells. They develop in the vestibular branch of the eighth cranial nerve in the internal auditory canal or cerebellopontine angle. The clinical progression of the condition involves slow and progressive growth, eventually resulting in brainstem compression. The objective of the present study was to investigate the expression level and the localization of the pro-inflammatory cytokines, transforming growth factor-?1 (TGF-?1) interleukin (IL)-1?, IL-6 and tumor necrosis factor-? (TNF-?), as well as the adhesion molecules, intracellular adhesion molecule-1 and vascular endothelial growth factor (VEGF), in order to determine whether these factors are involved in the transformation and development of human vestibular schwannoma. The present study investigated whether changes in inflammation are involved in tumor growth and if so, the mechanisms underlying this process. The results of the current study demonstrated that pro-inflammatory cytokines, including TGF-?1, IL-1? and IL-6 exhibited increased expression in human vestibular schwannoma tissue compared with normal vestibular nerve samples. TNF-? was weakly expressed in Schwann cells, confirming that a lower level of this cytokine is involved in the proliferation of Schwann cells. Neoplastic Schwann cells produce pro-inflammatory cytokines that may act in an autocrine manner, stimulating cellular proliferation. In addition, the increased expression of VEGF in vestibular schwannoma compared with that in normal vestibular nerve tissue, suggests that this factor may induce neoplastic growth via the promotion of angiogenesis. The present findings suggest that inflammation may promote angiogenesis and consequently contribute to tumor progression. In conclusion, the results of the present study indicated that VEGF and pro-inflammatory cytokines may be potential therapeutic targets in vestibular schwannoma. Further studies are necessary to confirm the involvement of these factors in the growth of neoplasms and to develop inhibitors of pro-inflammatory cytokines as a potential treatment option in the future. PMID:25738867

  9. Fine structural changes in the lateral vestibular nucleus of aging rats

    Science.gov (United States)

    Johnson, J. E., Jr.; Miquel, J.

    1974-01-01

    The fine structure of the lateral vestibular nucleus was investigated in Sprague-Dawley rats, that were sacrified at 4 weeks, 6-8 weeks, 6-8 months, and 18-20 months of age. In the neuronal perikaria, the following age-associated changes were seen with increasing frequency with advancing age: rodlike nuclear inclusions and nuclear membrane invaginations; cytoplasmic dense bodies with the characteristics of lipofuscin; and moderate disorganization of the granular endoplasmic reticulum. Dense bodies were also seen in glial cells. Rats 18 to 20 months old showed dendritic swellings, axonal degeneration, and an apparent increase in the number of axosomatic synaptic terminals containing flattened vesicles (presumed to be inhibitory in function).

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

    Scientific Electronic Library Online (English)

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

    2006-06-01

    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 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.

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

    Scientific Electronic Library Online (English)

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

    2013-06-01

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

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

    Science.gov (United States)

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

    2011-01-01

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

  13. Vestibular rehabilitation ameliorates chronic dizziness through the SIRT1 axis

    Directory of Open Access Journals (Sweden)

    Chung-Lan Kao

    2014-03-01

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

  14. Noisy galvanic vestibular stimulation enhances spatial memory in cognitive impairment-induced by intracerebroventricular-streptozotocin administration.

    Science.gov (United States)

    Adel Ghahraman, Mansoureh; Zahmatkesh, Maryam; Pourbakht, Akram; Seifi, Behjat; Jalaie, Shohreh; Adeli, Soheila; Niknami, Zohreh

    2016-04-01

    There are several anatomical connections between vestibular system and brain areas construct spatial memory. Since subliminal noisy galvanic vestibular stimulation (GVS) has been demonstrated to enhance some types of memory, we speculated that application of noisy GVS may improve spatial memory in a rat model of intracerebroventricular streptozotocin (ICV-STZ)-induced cognitive impairment. Moreover, we attempted to determine the effect of repeated exposure to GVS on spatial memory performance. The spatial memory was assessed using Morris water maze test. The groups received 1 (ICV-STZ/GVS-I) or 5 (ICV-STZ/GVS-II) sessions, each lasting 30min, of low amplitude noisy GVS, or no GVS at all (Control, ICV-saline, ICV-STZ/noGVS). Hippocampal morphological changes investigated with cresyl violet staining and the immediate early gene product c-Fos, as a neuronal activity marker, was measured. Hippocampal c-Fos positive cells increased in both GVS stimulated groups. We observed significantly improved spatial performance only in ICV-STZ/GVS-II group. Histological evaluation showed normal density in ICV-STZ/GVS-II group whereas degeneration observed in ICV-STZ/GVS-I group similar to ICV-STZ/noGVS. The results showed the improvement of memory impairment after repeated exposure to GVS. This effect may be due in part to frequent activation of the vestibular neurons and the hippocampal regions connected to them. Our current study suggests the potential role of GVS as a practical method to combat cognitive decline induced by sporadic Alzheimer disease. PMID:26892259

  15. Advances in the Diagnosis and Treatment of Vestibular Disorders: Psychophysics and Prosthetics

    OpenAIRE

    Lewis, Richard F.

    2015-01-01

    Although vestibular disorders are common and often disabling, they remain difficult to diagnose and treat. For these reasons, considerable interest has been focused on developing new ways to identify peripheral and central vestibular abnormalities and on new therapeutic options that could benefit the numerous patients who remain symptomatic despite optimal therapy. In this review, I focus on the potential utility of psychophysical vestibular testing and vestibular prosthetics. The former offe...

  16. Nasal Vestibular Huge Keratoacanthoma: An Unusual Site

    Directory of Open Access Journals (Sweden)

    N. Yazdani

    2009-01-01

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

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

    Science.gov (United States)

    Dieterich, Marianne; Brandt, Thomas

    2015-04-01

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

  18. Action Representation in Patients with Bilateral Vestibular Impairments

    Science.gov (United States)

    Demougeot, Laurent; Toupet, Michel; Van Nechel, Christian; Papaxanthis, Charalambos

    2011-01-01

    During mental actions subjects feel themselves performing a movement without any corresponding motor output. Although broad information is available regarding the influence of central lesions on action representation, little is known about how peripheral damages affect mental events. In the current study, we investigated whether lack of vestibular information influences action representation. Twelve healthy adults and twelve patients with bilateral vestibular damage actually performed and mentally simulated walking and drawing. The locomotor paths implied one (first walking task) and four (second walking task) changes in the walking direction. In the drawing task, participants drew on a sheet of paper a path that was similar to that of the second walking task. We recorded and compared between the two groups the timing of actual and mental movements. We found significant temporal discrepancies between actual and mental walking movements in the group of patients. Conversely, drawing actual and drawing mental durations were similar. For the control group, an isochrony between mental and actual movements was observed for the three tasks. This result denotes an inconsistency between action representation and action execution following vestibular damage, which is specific to walking movements, and emphasizes the role of the vestibular system upon mental states of actions. This observation may have important clinical implications. During action planning vestibular patients may overestimate the capacity of their motor system (imaging faster, executing slower) with harmful consequences for their health. PMID:22039548

  19. [Pharmacotherapy of Vestibular Disorders, Nystagmus and Cerebellar Disorders].

    Science.gov (United States)

    Feil, K; Böttcher, N; Kremmyda, O; Muth, C; Teufel, J; Zwergal, A; Brandt, T; Strupp, M

    2015-09-01

    There are currently different groups of drugs for the pharmacotherapy of vertigo, nystagmus and cerebellar disorders: antiemetics; anti-inflammatories, antimenieres, and antimigraineous medications and antidepressants, anticonvulsants, aminopyridines as well as acetyl-DL-leucine. In acute unilateral vestibulopathy, corticosteroids improve the recovery of peripheral vestibular function, but currently there is not sufficient evidence for a general recommendation. There is insufficient evidence to support the view that 16 mg t. i. d. or 48 mg t. i. d. betahistine has an effect in Menière's disease. Therefore, higher dosages are recommended. In animal studies, it was shown that betahistine increases cochlear blood flow. In vestibular paroxysmia, oxcarbazepine was effective (one randomized controlled trial (RCT)). Aminopyridines are recommended for the treatment of downbeat nystagmus (two RCTs) and episodic ataxia type 2 (EA2, one RCT). There has been no RCT on the efficacy of beta-blockers or topiramate but one RCT on flunarizine in vestibular migraine. Based on clinical experience, a treatment analogous to that for migraine without aura can be recommended. Acetyl-DL-leucine improved cerebellar ataxia (two observational studies); it also accelerated central compensation in an animal model of acute unilateral lesion, but RCTs were negative. There are ongoing RCTs on treatment of vestibular paroxysmia with carbamazepine (VESPA), acute unilateral vestibulopathy with betahistine (BETAVEST), vestibular migraine with metoprolol (PROVEMIG), benign paroxysmal positional vertigo with vitamin D (VitD@BPPV), EA2 with 4-aminopyridine versus acetazolamide (EAT-2-TREAT), and cerebellar ataxias with acetyl-DL-leucine (ALCAT). PMID:26421856

  20. Doença vestibular em cães: 81 casos (2006-2013

    Directory of Open Access Journals (Sweden)

    Rafael O. Chaves

    2014-12-01

    Full Text Available De 2006 a 2013 foram diagnosticados 81 casos de doença vestibular canina no serviço de rotina em neurologia de um hospital veterinário universitário do sul do Brasil. Desses, aproximadamente dois terços foram diagnosticados com doença vestibular central (DVC e cerca de um terço como doença vestibular periférica (DVP. Cães com raça definida foram mais acometidos que aqueles sem raça definida, principalmente Dachshund (DVP e Boxer (DVC. Os principais sinais clínicos observados, tanto na DVP quanto na DVC, incluíram: inclinação de cabeça, ataxia vestibular e estrabismo ventral ou ventrolateral. Deficiência proprioceptiva, disfunção dos nervos cranianos V-XII e alteração de nível de consciência foram vistos apenas em casos de DVC, já a ausência de reflexo palpebral ocorreu apenas em casos de DVP. Doenças inflamatórias/infecciosas, principalmente cinomose e otite bacteriana, foram as condições mais comumente associadas à DVC e à DVP, respectivamente. Esse artigo estabelece os aspectos epidemiológicos (sexo, idade e raça e a prevalência dos sinais clínicos observados em cães com doença vestibular na Região Central do Rio Grande do Sul, discute a utilização dos achados clínicos no diagnóstico correto e na diferenciação entre DVC e DVP, e define quais as principais doenças responsáveis pela ocorrência dessas duas síndromes clínicas.

  1. Binding body and self in visuo-vestibular conflicts.

    Science.gov (United States)

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

    2015-03-01

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

  2. Vestibular deficits do not underlie looping behavior in achiasmatic fish.

    Science.gov (United States)

    Huang, Ying-Yu; Tschopp, Markus; Straumann, Dominik; Neuhauss, Stephan C F

    2010-07-01

    Zebrafish belladonna (bel) mutants carry a mutation in the lhx2 gene that encodes a Lim domain homeobox transcription factor, leading to a defect in the retinotectal axon pathfinding. As a result, a large fraction of homozygous bel mutants is achiasmatic. Achiasmatic bel mutants display ocular motor instabilities, both reserved optokinetic response (OKR) and spontaneous eye oscillations, and an unstable swimming behavior, described as looping. All these unstable behaviors have been linked to the underlying optic nerve projection defect. Looping has been investigated under different visual stimuli and shown to be vision dependent and contrast sensitive. In addition, looping correlates perfectly with reversed OKR and the spontaneous oscillations of the eyes. Hence, it has been hypothesized that looping is a compensatory response to the perception of self-motion induced by the spontaneous eye oscillations. However, both ocular and postural instabilities could also be caused by a yet unidentified vestibular deficit. Here, we performed a preliminary test of the vestibular function in achiasmatic bel larval mutants in order to clarify the potential role of a vestibular deficit in looping. We found that the vestibular ocular reflex (VOR) is normally directed in both bel mutants and wild types and therefore exclude the possibility that nystagmus and looping in reverse to the rotating optokinetic drum can be attributed to an underlying vestibular deficit. PMID:20798832

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

    DEFF Research Database (Denmark)

    Friberg, L; Olsen, T S; Roland, P E; Paulson, O B; Lassen, N A

    This study is an attempt to reveal projection areas for vestibular afferents to the human brain. Changes in regional cerebral blood flow (rCBF) were measured over 254 cortical regions during caloric vestibular stimulation with warm water (44 degrees C). rCBF was measured when the external auditor...... stimulation that gives rise to the associated conscious vestibular sensation of vertigo....

  4. The Vestibular-Evoked Postural Response of Adolescents with Idiopathic Scoliosis Is Altered

    OpenAIRE

    Pialasse, Jean-Philippe; Descarreaux, Martin; Mercier, Pierre; Blouin, Jean; Simoneau, Martin

    2015-01-01

    Adolescent idiopathic scoliosis is a multifactorial disorder including neurological factors. A dysfunction of the sensorimotor networks processing vestibular information could be related to spine deformation. This study investigates whether feed-forward vestibulomotor control or sensory reweighting mechanisms are impaired in adolescent scoliosis patients. Vestibular evoked postural responses were obtained using galvanic vestibular stimulation while participants stood with their eyes closed an...

  5. Evaluation of central and peripheral vestibular patients with the video-head impulse test

    OpenAIRE

    Luís, Leonel Almeida

    2015-01-01

    Dizziness and vertigo are highly prevalent symptoms that accompany a wide variety of conditions including peripheral vestibular dysfunction, central (vestibular) lesions and somatoform disorders. A correct diagnosis is the prerequisite for successful treatment, which should be directed towards the underlying pathophysiology. Neurophysiological methods that test the integrity of the peripheral and central vestibular system circuitry are essential to make an accurate diagnosis...

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

    Directory of Open Access Journals (Sweden)

    Mohammed T

    2010-01-01

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

  7. The Effects of Aging on Clinical Vestibular Evaluations

    Science.gov (United States)

    Maheu, Maxime; Houde, Marie-Soleil; Landry, Simon P.; Champoux, François

    2015-01-01

    Balance disorders are common issues for aging populations due to the effects of normal aging on peripheral vestibular structures. These changes affect the results of vestibular function evaluations and make the interpretation of these results more difficult. The objective of this article is to review the current state of knowledge of clinically relevant vestibular measures. We will first focus on otolith function assessment methods cervical-VEMP (cVEMP) and ocular-VEMP (oVEMP), then the caloric and video-head impulse test (vHIT) methods for semicircular canals assessment. cVEMP and oVEMP are useful methods, though research on the effects of age for some parameters are still inconclusive. vHIT results are largely independent of age as compared to caloric stimulation and should therefore be preferred for the evaluation of the semicircular canals function. PMID:26441824

  8. Visual gravitational motion and the vestibular system in humans

    Directory of Open Access Journals (Sweden)

    Francesco Lacquaniti

    2013-12-01

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

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

    Science.gov (United States)

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

    2013-01-01

    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. PMID:24421761

  10. A model analysis of static stress in the vestibular membranes

    Directory of Open Access Journals (Sweden)

    Pender Daniel J

    2009-09-01

    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.

  11. Modulation of human vestibular reflexes with increased postural threat.

    Science.gov (United States)

    Horslen, Brian C; Dakin, Christopher J; Inglis, J Timothy; Blouin, Jean-Sébastien; Carpenter, Mark G

    2014-08-15

    Anxiety and arousal have been shown to facilitate human vestibulo-ocular reflexes, presumably through direct neural connections between the vestibular nuclei and emotional processing areas of the brain. However, the effects of anxiety, fear and arousal on balance-relevant vestibular reflexes are currently unknown. The purpose of this study was to manipulate standing height to determine whether anxiety and fear can modulate the direct relationship between vestibular signals and balance reflexes during stance. Stochastic vestibular stimulation (SVS; 2-25 Hz) was used to evoke ground reaction forces (GRF) while subjects stood in both LOW and HIGH surface height conditions. Two separate experiments were conducted to investigate the SVS-GRF relationship, in terms of coupling (coherence and cumulant density) and gain, in the medio-lateral (ML) and antero-posterior (AP) directions. The short- and medium-latency cumulant density peaks were both significantly increased in the ML and AP directions when standing in HIGH, compared to LOW, conditions. Likewise, coherence was statistically greater between 4.3 Hz and 6.7 Hz in the ML, and between 5.5 and 17.7 Hz in the AP direction. When standing in the HIGH condition, the gain of the SVS-GRF relationship was increased 81% in the ML direction, and 231% in the AP direction. The significant increases in coupling and gain observed in both experiments demonstrate that vestibular-evoked balance responses are augmented in states of height-induced postural threat. These data support the possibility that fear or anxiety-mediated changes to balance control are affected by altered central processing of vestibular information. PMID:24973412

  12. Plasticity during vestibular compensation: the role of saccades

    Directory of Open Access Journals (Sweden)

    IanSCurthoys

    2012-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Birgul DONMEZ

    2008-06-01

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

  14. Interrelated striated elements in vestibular hair cells of the rat

    Science.gov (United States)

    Ross, M. D.; Bourne, C.

    1983-01-01

    A series of interrelated striated organelles in types I and II vestibular hair cells of the rat which appear to be less developed in cochlear hair cells have been revealed by unusual fixation procedures, suggesting that contractile elements may play a role in sensory transduction in the inner ear, especially in the vestibular system. Included in the series of interrelated striated elements are the cuticular plate and its basal attachments to the hair cell margins, the connections of the strut array of the kinociliary basal body to the cuticular plate, and striated organelles associated with the plasma membrane and extending below the apical junctional complexes.

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

    Scientific Electronic Library Online (English)

    Maysa Bastos, Rabelo; Corona, Ana Paula.

    2014-10-01

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

  16. Gaze stabilization and gait performance in vestibular dysfunction

    Science.gov (United States)

    Whitney, Susan L.; Marchetti, Gregory F.; Pritcher, Miranda; Furman, Joseph M.

    2016-01-01

    Background The gaze stability test (GST) quantifies the ability of a person to recognize a target projected on a personal computer monitor during active head movement. Purpose The purpose of this study was to determine if there was a relationship between clinical measures of walking performance and the GST in patients with vestibular disorders and in healthy subjects. We hypothesized that impairment of the ability to keep objects in focus during active head movement would be correlated with walking performance. Subjects Twenty older asymptomatic adults acted as controls and 12 patients with either unilateral or bilateral vestibular disease participated. Methods The GST quantifies the maximum velocity that a person can move their head in the pitch and yaw planes while retaining the ability to read an optotype that is momentarily projected onto a computer screen. Subjects were scored while performing the Dynamic Gait Index (DGI) and the Timed “Up & Go” (TUG) tests. Results Walking performance on the DGI and TUG were significantly associated with GST results in subjects with vestibular disorders, but not in control subjects. Abnormalities of gait could be identified by GST cutoff values of 658 s_1 in the pitch plane and 638 s_1 in the yaw plane. Discussion/conclusion In older subjects with vestibular disorders, gaze stability, as assessed by the GST, is associated with reduced test scores on measures of gait performance. PMID:18815040

  17. Hippocampal gray matter volume in bilateral vestibular failure.

    Science.gov (United States)

    Göttlich, Martin; Jandl, Nico M; Sprenger, Andreas; Wojak, Jann F; Münte, Thomas F; Krämer, Ulrike M; Helmchen, Christoph

    2016-05-01

    Bilateral vestibular failure (BVF) is a severe chronic disorder of the labyrinth or the eighth cranial nerve characterized by unsteadiness of gait and disabling oscillopsia during head movements. According to animal data, vestibular input to the hippocampus is proposed to contribute to spatial memory and spatial navigation. Except for one seminal study showing the association of impaired spatial navigation and hippocampal atrophy, patient data in BVF are lacking. Therefore, we performed a voxel-wise comparison of the hippocampal gray matter volume (GMV) in a clinically representative sample of 27 patients with incomplete BVF and 29 age- and gender-matched healthy controls to test the hypothesis of hippocampal atrophy in BVF. Although the two groups did not generally differ in their hippocampal GMV, a reduction of GMV in the bilateral hippocampal CA3 region was significantly correlated with increased vestibulopathy-related clinical impairment. We propose that GMV reduction in the hippocampus of BVF patients is related to the severity of vestibular-induced disability which is in line with combined hippocampal atrophy and disorders of spatial navigation in complete vestibular deafferentation due to bilateral nerve section. Clinically, however, the most frequent etiologies of BVF cause incomplete lesions. Accordingly, hippocampus atrophy and deficits in spatial navigation occur possibly less frequently than previously suspected. Hum Brain Mapp 37:1998-2006, 2016. © 2016 Wiley Periodicals, Inc. PMID:26918638

  18. Facial Nerve Outcome after Vestibular Schwannoma Surgery: Our Experience*

    OpenAIRE

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

    2012-01-01

    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...

  19. Current concepts and future approaches to vestibular rehabilitation.

    Science.gov (United States)

    Tjernström, Fredrik; Zur, Oz; Jahn, Klaus

    2016-04-01

    Over the last decades methods of vestibular rehabilitation to enhance adaptation to vestibular loss, habituation to changing sensory conditions, and sensory reweighting in the compensation process have been developed. However, the use of these techniques still depends to a large part on the educational background of the therapist. Individualized assessment of deficits and specific therapeutic programs for different disorders are sparse. Currently, vestibular rehabilitation is often used in an unspecific way in dizzy patients irrespective of the clinical findings. When predicting the future of vestibular rehabilitation, it is tempting to foretell advances in technology for assessment and treatment only, but the current intense exchange between clinicians and basic scientists also predicts advances in truly understanding the complex interactions between the peripheral senses and central adaptation mechanisms. More research is needed to develop reliable techniques to measure sensory dependence and to learn how this knowledge can be best used-by playing off the patient's sensory strength or working on the weakness. To be able using the emerging concepts, the neuro-otological community must strive to educate physicians, physiotherapists and nurses to perform the correct examinations for assessment of individual deficits and to look for factors that might impede rehabilitation. PMID:27083886

  20. Abnormal Tilt Perception During Centrifugation in Patients with Vestibular Migraine.

    Science.gov (United States)

    Wang, Joanne; Lewis, Richard F

    2016-06-01

    Vestibular migraine (VM), defined as vestibular symptoms caused by migraine mechanisms, is very common but poorly understood. Because dizziness is often provoked in VM patients when the semicircular canals and otolith organs are stimulated concurrently (e.g., tilting the head relative to gravity), we measured tilt perception and eye movements in patients with VM and in migraine and normal control subjects during fixed-radius centrifugation, a paradigm that simultaneously modulates afferent signals from the semicircular canals and otoliths organs. Twenty-four patients (8 in each category) were tested with a motion paradigm that generated an inter-aural centrifugal force of 0.36 G, resulting in a 20° tilt of the gravito-inertial force in the roll plane. We found that percepts of roll tilt developed slower in VM patients than in the two control groups, but that eye movement responses, including the shift in the eye's rotational axis, were equivalent in all three groups. These results demonstrate a change in vestibular perception in VM that is unaccompanied by changes in vestibular-mediated eye movements and suggest that either the brain's integration of canal and otolith signals or the dynamics of otolith responses are aberrant in patients with VM. PMID:26956976

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

    DEFF Research Database (Denmark)

    Stangerup, Sven-Eric; Tos, Mirko; Caye-Thomasen, Per; Tos, Tina; Klokker, Mads; Thomsen, Jens

    2004-01-01

    During the last 26 years the annual number of diagnosed vestibular schwannomas (VS) has been increasing. The aim of this study is to describe and analyse this increase. Since 1976, 1446 new cases of VS have been diagnosed at the authors' centre. Special focus was on the age at diagnosis, the...

  2. What is the real incidence of vestibular schwannoma?

    DEFF Research Database (Denmark)

    Tos, Mirko; Stangerup, Sven-Eric; Cayé-Thomasen, Per; Tos, Tina; Thomsen, Jens

    2004-01-01

    OBJECTIVES: To present the incidence of vestibular schwannoma (VS) in Denmark, compare the incidence with that of previous periods, and discuss the real incidence of VS. DESIGN, SETTING, AND PATIENTS: Prospective registration of all diagnosed VS in Denmark, with a population of 5.1 to 5.2 million...

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

    DEFF Research Database (Denmark)

    Schüz, Joachim; Steding-Jessen, Marianne; Hansen, Søren; Stangerup, Sven-Eric; Cayé-Thomasen, Per; Johansen, Christoffer

    2010-01-01

    Vestibular schwannoma (VS) (or acoustic neuroma) accounts for about 5%-6% of all intracranial tumors; little is known about the etiology. We investigated the association between various sociodemographic indicators and VS in a cohort of 3.26 million Danish residents, with 1087 cases identified in 35...

  4. Vestibular Stimulation and Development of the Small Premature Infant.

    Science.gov (United States)

    Neal, Mary V.

    This study was designed to explore the effects of vestibular stimulation on the developmental behavior, respiratory functioning, weight and length gains, and morbidity and mortality rates of premature infants. A total of 20 infants participated in this study in 4 groups of 5 infants each. Group A infants were placed in a motorized hammock within…

  5. Stimulus Characteristics for Vestibular Stochastic Resonance to Improve Balance Function

    Science.gov (United States)

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

    2010-01-01

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

  6. 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)

    Léia Gonçalves Gurgel

    2012-02-01

    Full Text Available Fatores cognitivos e emocionais podem afetar o equilíbrio, portanto, condições psiquiátricas são comuns em pacientes otoneurológicos. O tratamento dado ao sujeito vertiginoso pode ser mais influenciado pelo sofrimento e comportamento da doença do que pela gravidade da patologia orgânica. OBJETIVO: 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.

  7. Mice with conditional deletion of Cx26 exhibit no vestibular phenotype despite secondary loss of Cx30 in the vestibular end organs.

    Science.gov (United States)

    Lee, Min Young; Takada, Tomoko; Takada, Yohei; Kappy, Michelle D; Beyer, Lisa A; Swiderski, Donald L; Godin, Ashley L; Brewer, Shannon; King, W Michael; Raphael, Yehoash

    2015-10-01

    Connexins are components of gap junctions which facilitate transfer of small molecules between cells. One member of the connexin family, Connexin 26 (Cx26), is prevalent in gap junctions in sensory epithelia of the inner ear. Mutations of GJB2, the gene encoding Cx26, cause significant hearing loss in humans. The vestibular system, however, does not usually show significant functional deficits in humans with this mutation. Mouse models for loss of Cx26 function demonstrate hearing loss and cochlear pathology but the extent of vestibular dysfunction and organ pathology are less well characterized. To understand the vestibular effects of Cx26 mutations, we evaluated vestibular function and histology of the vestibular sensory epithelia in a conditional knockout (CKO) mouse with Cx26 loss of function. Transgenic C57BL/6 mice, in which cre-Sox10 drives excision of the Cx26 gene from non-sensory cells flanking the sensory epithelium of the inner ear (Gjb2-CKO), were compared to age-matched wild types. Animals were sacrificed at ages between 4 and 40 weeks and their cochlear and vestibular sensory organs harvested for histological examination. Cx26 immunoreactivity was prominent in the peripheral vestibular system and the cochlea of wild type mice, but absent in the Gjb2-CKO specimens. The hair cell population in the cochleae of the Gjb2-CKO mice was severely depleted but in the vestibular organs it was intact, despite absence of Cx26 expression. The vestibular organs appeared normal at the latest time point examined, 40 weeks. To determine whether compensation by another connexin explains survival of the normal vestibular sensory epithelium, we evaluated the presence of Cx30 in the Gjb2-CKO mouse. We found that Cx30 labeling was normal in the cochlea, but it was decreased or absent in the vestibular system. The vestibular phenotype of the mutants was not different from wild-types as determined by time on the rotarod, head stability tests and physiological responses to vestibular stimulation. Thus presence of Cx30 in the cochlea does not compensate for Cx26 loss, and the absence of both connexins from vestibular sensory epithelia is no more injurious than the absence of one of them. Further studies to uncover the physiological foundation for this difference between the cochlea and the vestibular organs may help in designing treatments for GJB2 mutations. PMID:26232528

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

    Directory of Open Access Journals (Sweden)

    Tatiane Maria Rossi

    2009-01-01

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

  9. Structural and functional connectivity mapping of the vestibular circuitry from human brainstem to cortex.

    Science.gov (United States)

    Kirsch, V; Keeser, D; Hergenroeder, T; Erat, O; Ertl-Wagner, B; Brandt, T; Dieterich, M

    2016-04-01

    Structural and functional interconnections of the bilateral central vestibular network have not yet been completely delineated. This includes both ipsilateral and contralateral pathways and crossing sites on the way from the vestibular nuclei via the thalamic relay stations to multiple "vestibular cortex" areas. This study investigated "vestibular" connectivity in the living human brain in between the vestibular nuclei and the parieto-insular vestibular cortex (PIVC) by combined structural and functional connectivity mapping using diffusion tensor imaging and functional connectivity magnetic resonance imaging in 24 healthy right-handed volunteers. We observed a congruent functional and structural link between the vestibular nuclei and the ipsilateral and contralateral PIVC. Five separate and distinct vestibular pathways were identified: three run ipsilaterally, while the two others cross either in the pons or the midbrain. Two of the ipsilateral projections run through the posterolateral or paramedian thalamic subnuclei, while the third bypasses the thalamus to reach the inferior part of the insular cortex directly. Both contralateral pathways travel through the posterolateral thalamus. At the cortical level, the PIVC regions of both hemispheres with a right hemispherical dominance are interconnected transcallosally through the antero-caudal splenium. The above-described bilateral vestibular circuitry in its entirety takes the form of a structure of a rope ladder extending from the brainstem to the cortex with three crossings in the brainstem (vestibular nuclei, pons, midbrain), none at thalamic level and a fourth cortical crossing through the splenium of the corpus callosum. PMID:25552315

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

    Directory of Open Access Journals (Sweden)

    Eduardo M. Kosugi

    2004-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Alejandro Peña M

    2012-04-01

    Full Text Available Recientes estudios clínicos han revelado la utilidad del test del nistagmus inducido por la hiperventilación aguda, en la investigación de patologías vestibulares retrolaberínticas, neurales y de origen central, con la aparición de nistagmus paréticos o bien excitatorios. El propósito de este estudio ha sido: primero, conocer la sensibilidad de este examen según el análisis de los estudios de diferentes autores; segundo, entender la fisiopatología de este nistagmus inducido por la hiperventilación y tercero, efectuar una interpretación y análisis de este examen que permita obtener conclusiones sólidas del mejor nivel de medicina basada en evidencias. Para efectuar este estudio y análisis se procedió a una investigación exhaustiva de las publicaciones sobre el tema en los últimos 25 años, recurriendo para ello como fuentes de información a las principales bases de datos biomédicos y a la revisión en texto completo de estas publicaciones. Llamó la atención la escasez de trabajos clínicos publicados sobre el tema que no superan los 40, y también la escasez de trabajos sobre la fisiopatología del nistagmus inducido por la hiperventilación aguda. La metódica del test es muy simple por lo que su utilización resulta muy atractiva, con un escaso número de falsos positivos. La mayor parte de los estudios publicados, se focaliza en su utilización en el schwanoma vestibularyen la neuronitis vestibular. Respecto al schwanoma vestibular de un total de 107 pacientes estudiados el test fue positivo en el 80% de los casos, con aparición de nistagmus ipsilesional o contralesional. En la neuronitis vestibular la positividad del test alcanzó a 60°% de un total de 272 pacientes estudiados y que estaba en relación directa con el tiempo de evolución de la enfermedad. En la esclerosis múltiple, en pacientes con síntomas vestibulares, la positividad del test fue de 75°%, en cambio en aquellos pacientes sin síntomas vestibulares la positividad fue de sólo 7°%. En las enfermedades cerebelosas, particularmente las degenerativas, la positividad de este test fue de 78°%. La pesquisa del nistagmus inducido por la hiperventilación, fue una prueba poco significativa estadísticamente, en otras patologías vestibulares períféricas tales como la enfermedad de Ménière o el VPPB, así como en otras enfermedades vestibulares centrales, salvo las de origen vascular por insuficiencia del sistema vértebro-basilar. El estudio y análisis de las publicaciones sobre el nistagmus inducido por la hiperventilación aguda, permite concluir que es un test de fácil realización; que ante la sospecha de un schwanoma vestibular, orienta en el estudio de aquellos pacientes que requieran un estudio de R.M. Que ayuda en el diagnóstico diferencial de una neuronitisvestibular y finalmente que permite en lesiones vestibulares centrales particularmente degenerativas y vasculares un estudio más profundo y adecuado de estos pacientes.Recent clinical studies have revealed the usefulness of the hyperventilation-induced nystagmus in retrolabyrinthine and central vestibular diseases with the appearance either excitatory (ipsilateral or paretic (contralateral nystagmus. The objectives of this study have been: 1 to get to know the sensitivity of the exam, according to the best literature available; 2 to get to know the physiopathology of this hyperventilation-induced nystagmus, and 3 to carry out an analysis and interpretation of this exam in order to reach solid conclusions of the highest level in evidence based medicine. An exhaustive research of literature published on this topic in the last 25 years was carried out. The main source of information being the most important medical data-based publications and also a thorough revision of these texts. The scarce number of publications on this topic (not more than 40 is what strikes the attention most, as well as the very few studies of the physiopathology of the hyperventilation-induced nystagmus. The method of the test is a simple one; this fact makes its application an attractive one, with a low number of false positive. Most of the studies published are focused on its application in the vestibular schwannoma and in the vestibular neuritis. As to what the Vestibular schwannoma is concerned, ofa group of 107 patients studied, the test was positive in 80%% of the cases, with the appearance of ipsilesional or contralesional nystagmus. In vestibular neuritis the test was positive in 68 % of a number of272patients; this amount was in direct correlation with the time of evolution of the disease. In multiple sclerosis, in patients with vestibular symptoms, the test gave positive in 75%%, whereas in those patients without vestibular symptoms it was positive only in 7%%. In patients with cerebellar diseases, particularly degenerative ones this test was positive in 78%% of the cases. The search of hyperventilation-induced nystagmus was a statistically non significant one in some peripheral diseases such as Ménière' disease or BPPV, as well as in other central vestibular disease, except those of vascular origin due to vertebra-basilar dysfunction. The study and the analysis ofliterature on the hyperventilation-induced nystagmus allow the conclusion that this a test of easy application. When a vestibular schwannoma is suspected, the test guides in the study of those patients that require an MRI. It also helps in the differential diagnosis ofa Vestibular neuritis. Finally, in degenerative and vascular central vestibular disorders, it allows a thorough and more suitable study of the patients.

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

    Science.gov (United States)

    Fritzsch, Bernd

    2003-01-01

    The molecular and cellular origin of the primary neurons of the inner ear, the vestibular and spiral neurons, is reviewed including how they connect to the specific sensory epithelia and what the molecular nature of their survival is. Primary neurons of the ear depend on a single basic Helix-Loop-Helix (bHLH) protein for their formation, neurogenin 1 (ngn1). An immediate downstream gene is the bHLH gene neuronal differentiation (NeuroD). Targeted null mutations of ngn1 results in absence of primary neuron formation; targeted null mutation of NeuroD results in loss of almost all spiral and many vestibular neurons. NeuroD and a later expressed gene, Brn3a, play a role in pathfinding to and within sensory epithelia. The molecular nature of this pathfinding property is unknown. Reduction of hair cells in ngn1 null mutations suggests a clonal relationship with primary neurons. This relationship may play some role in specifying the identity of hair cells and the primary neurons that connect with them. Primary neuron neurites growth to sensory epithelia is initially independent of trophic factors released from developing sensory epithelia, but becomes rapidly dependent on those factors. Null mutations of specific neurotrophic factors lose distinct primary neuron populations which undergo rapid embryonic cell death.

  13. Visual-vestibular integration motion perception reporting

    Science.gov (United States)

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

    1999-01-01

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

  14. Galvanic vestibular stimulator for fMRI studies

    Scientific Electronic Library Online (English)

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

    2014-03-01

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

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

    Directory of Open Access Journals (Sweden)

    Christophe Lopez

    2013-12-01

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

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

    Directory of Open Access Journals (Sweden)

    A.G. Pillay

    1999-01-01

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

  17. 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.

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

    OpenAIRE

    Kapoula, Zoï; Gaertner, Chrystal; Yang, Qing; Denise, Pierre; Toupet, Michel

    2013-01-01

    There is a natural symbiosis between vergence and vestibular responses. Deficits in vergence can lead to vertigo, disequilibrium, and postural instability. This study examines both vergence eye movements in patients with idiopathic bilateral vestibular loss, and their standing balance in relation to vergence. Eleven patients participated in the study and 16 controls. Bilateral loss of vestibular function was objectified with many tests; only patients without significant response to caloric te...

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

    OpenAIRE

    Christophe Lopez

    2013-01-01

    The consequences of vestibular disorders on balance, oculomotor control and self-motion perception have been extensively described in humans and animals. More recently, vestibular disorders have been related to cognitive deficits in spatial navigation and memory tasks. Less frequently, abnormal bodily perceptions have been described in patients with vestibular disorders. Altered forms of bodily self-consciousness include distorted body image and body schema, disembodied self-location (out-of-...

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

    OpenAIRE

    Lopez, Christophe

    2013-01-01

    The consequences of vestibular disorders on balance, oculomotor control, and self-motion perception have been extensively described in humans and animals. More recently, vestibular disorders have been related to cognitive deficits in spatial navigation and memory tasks. Less frequently, abnormal bodily perceptions have been described in patients with vestibular disorders. Altered forms of bodily self-consciousness include distorted body image and body schema, disembodied self-location (out-of...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-01-01

    Several animal models of vestibular deficits that mimic the human pathology phenotype have previously been developed to correlate the degree of vestibular injury to cognate vestibular deficits in a time-dependent manner. Sodium arsanilate is one of the most commonly used substances for chemical vestibular lesioning, but it is not well described in the literature. In the present study, we used histological and functional approaches to conduct a detailed exploration of the model of vestibular lesions induced by transtympanic injection of sodium arsanilate in rats. The arsanilate-induced damage was restricted to the vestibular sensory organs without affecting the external ear, the oropharynx, or Scarpa's ganglion. This finding strongly supports the absence of diffusion of arsanilate into the external ear or Eustachian tubes, or through the eighth cranial nerve sheath leading to the brainstem. One of the striking observations of the present study is the complete restructuring of the sensory epithelia into a non sensory epithelial monolayer observed at 3 months after arsanilate application. This atrophy resembles the monolayer epithelia observed postmortem in the vestibular epithelia of patients with a history of lesioned vestibular deficits such as labyrinthectomy, antibiotic treatment, vestibular neuritis, or Ménière's disease. In cases of Ménière's disease, aminoglycosides, and platinum-based chemotherapy, vestibular hair cells are destroyed, regardless of the physiopathological process, as reproduced with the arsanilate model of vestibular lesion. These observations, together with those presented in this study of arsanilate vestibular toxicity, suggest that this atrophy process relies on a common mechanism of degeneration of the sensory epithelia.

  2. Hyperventilation-induced nystagmus in a large series of vestibular patients

    OpenAIRE

    CALIFANO, L.; MELILLO, M.G.; A. Vassallo; Mazzone, S.

    2011-01-01

    The Hyperventilation Test is widely used in the "bed-side examination" of vestibular patients. It can either activate a latent nystagmus in central or peripheral vestibular diseases or it can interact with a spontaneous nystagmus, by reducing it or increasing it. Aims of this study were to determine the incidence, patterns and temporal characteristics of Hyperventilation-induced nystagmus in patients suffering from vestibular diseases, as well as its contribution to the differential diagnosis...

  3. Determination of the functional status of vestibular apparatus at children aged 5-6 years old.

    Directory of Open Access Journals (Sweden)

    Moiseenko E.K.

    2012-02-01

    Full Text Available The physiological methods of determination of the functional state of vestibular analyzer are considered. The indexes of systole and diastole pressure, frequencies of heart-throbs, are chosen. Methods were used before and after standard vestibular irritation. Research was conducted on the base of child's preschool establishment. In it took part 120 children in age 5 - 6 years. Insufficient development of vestibular analyzer is set for children. Selected exercise for the improvement of spatial orientation and statodynamic stability.

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

    OpenAIRE

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

    2012-01-01

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

  5. A large vestibular schwannoma after recent negative MRI: A case report.

    Science.gov (United States)

    Muelleman, Thomas J; Lin, James

    2016-01-01

    Vestibular schwannomas are, on average, slowly growing tumors that may remain quiescent for some time before manifesting themselves symptomatically or being found incidentally on imaging. We describe a case of a vestibular schwannoma that grew rapidly and to a large size in a patient who had undergone negative imaging 5 years earlier for unrelated issues. This case highlights the importance of repeat imaging in patients with symptoms concerning for vestibular schwannoma who might have previously undergone negative scans. PMID:27140025

  6. Multiple synchronous sites of origin of vestibular schwannomas in neurofibromatosis Type 2

    OpenAIRE

    Stivaros, Stavros M.; Stemmer-Rachamimov, Anat O; Alston, Robert; Plotkin, Scott R.; Nadol, Joseph B; Quesnel, Alicia; O'Malley, Jennifer; Whitfield, Gillian A; McCabe, Martin G; Freeman, Simon R; Lloyd, Simon K; Wright, Neville B; Kilday, John-Paul; Kamaly-Asl, Ian D; Mills, Samantha J

    2015-01-01

    Background: Neurofibromatosis Type 2 (NF2) is a dominantly inherited tumour syndrome with a phenotype which includes bilateral vestibular (eighth cranial nerve) schwannomas. Conventional thinking suggests that these tumours originate at a single point along the superior division of the eighth nerve. Methods: High resolution MRI was performed in children genetically proven to have NF2. The superior vestibular nerve (SVN) and inferior vestibular nerve (IVN) were visualised along their course wi...

  7. Multiple synchronous sites of origin of vestibular schwannomas in neurofibromatosis Type 2.

    OpenAIRE

    Stivaros, Stavros M.; Stemmer-Rachamimov, Anat O; Alston, Robert; Plotkin, Scott R.; Nadol, Joseph B; Quesnel, Alicia; O'Malley, Jennifer; Whitfield, Gillian A; McCabe, Martin G; Freeman, Simon R; Lloyd, Simon K; Wright, Neville B; Kilday, John-Paul; Kamaly-Asl, Ian D; Mills, Samantha J

    2015-01-01

    BACKGROUND: Neurofibromatosis Type 2 (NF2) is a dominantly inherited tumour syndrome with a phenotype which includes bilateral vestibular (eighth cranial nerve) schwannomas. Conventional thinking suggests that these tumours originate at a single point along the superior division of the eighth nerve. METHODS: High resolution MRI was performed in children genetically proven to have NF2. The superior vestibular nerve (SVN) and inferior vestibular nerve (IVN) were visualised along their course wi...

  8. 3D hybrid electrode structure as implantable interface for a vestibular neural prosthesis in humans

    OpenAIRE

    Hoffmann, Klaus-P; Poppendieck, Wigand; Tätzner, Simon; DiGiovanna, Jack; Kos, Maria Izabel; Guinand, Nils; Guyot, Jean-Philippe; Micera, Silvestro

    2011-01-01

    Implantable interfaces are essential components of vestibular neural prostheses. They interface the biological system with electrical stimulation that is used to restore transfer of vestibular information. Regarding the anatomical situation special 3D structures are required. In this paper, the design and the manufacturing process of a novel 3D hybrid microelectrode structure as interface to the human vestibular system are described. Photolithography techniques, assembling technology and rapi...

  9. Spatial properties of second-order vestibulo-ocular relay neurons in the alert cat.

    Science.gov (United States)

    Fukushima, K; Perlmutter, S I; Baker, J F; Peterson, B W

    1990-01-01

    Second-order vestibular nucleus neurons which were antidromically activated from the region of the oculomotor nucleus (second-order vestibuloocular relay neurons) were studied in alert cats during whole-body rotations in many horizontal and vertical planes. Sinusoidal rotation elicited sinusoidal modulation of firing rates except during rotation in a clearly defined null plane. Response gain (spike/s/deg/s) varied as a cosine function of the orientation of the cat with respect to a horizontal rotation axis, and phases were near that of head velocity, suggesting linear summation of canal inputs. A maximum activation direction (MAD) was calculated for each cell to represent the axis of rotation in three-dimensional space for which the cell responded maximally. Second-order vestibuloocular neurons divided into 3 non-overlapping populations of MADs, indicating primary canal input from either anterior, posterior or horizontal semicircular canal (AC, PC, HC cells). 80/84 neurons received primary canal input from ipsilateral vertical canals. Of these, at least 6 received input from more than one vertical canal, suggested by MAD azimuths which were sufficiently misaligned with their primary canal. In addition, 21/80 received convergent input from a horizontal canal, with about equal number of type I and type II yaw responses. 4/84 neurons were HC cells; all of them received convergent input from at least one vertical canal. Activity of many vertical second-order vestibuloocular neurons was also related to vertical and/or horizontal eye position. All AC and PC cells that had vertical eye position sensitivity had upward and downward on-directions, respectively. A number of PC cells had MADs centered around the MAD of the superior oblique muscle, and 2/3 AC cells recorded in the superior vestibular nucleus had MADs near that of the inferior oblique. Thus, signals with spatial properties appropriate to activate oblique eye muscles are present at the second-order vestibular neuron level. In contrast, none of the second-order vestibuloocular neurons had MADs near those of the superior or inferior rectus muscles. Signals appropriate to activate these eye muscles might be produced by combining signals from ipsilateral and contralateral AC neurons (for superior rectus) or PC neurons (for inferior rectus). Alternatively, less direct pathways such as those involving third or higher order vestibular or interstitial nucleus of Cajal neurons might play a crucial role in the spatial transformations between semicircular canals and vertical rectus eye muscles. PMID:2226682

  10. Space motion sickness and vestibular adaptation to weightlessness

    Science.gov (United States)

    Young, L. R.

    1983-01-01

    Theories of space motion sickness are discussed together with near future vestibular experiments for three Spacelab missions. The sensory conflict theory is covered, as well as theories involving unequal otolith masses, semicircular canals, cardiovascular adaptation and fluid shift toward the head, and extra-labyrinthine effects. Experiments will test the hypothesis that the sensitivity of the otolith organ response is shifted during weightlessness and that this shift carries over to the post-flight experience. Visual-vestibular-tactile interaction, vestibulo-ocular reflexes, ocular counterrolling, awareness of body position, otolith-spinal reflexes, and motion sickness susceptibility are among the parameters to be studied. Preflight and postflight tests will emphasize evaluation of any residual effects of the seven day weightless exposure on vestibulo-spinal and vestibulo-ocular pathways.

  11. Vestibular acoustic reception in the guinea pig: a saccular function?

    Science.gov (United States)

    Cazals, Y; Aran, J M; Erre, J P; Guilhaume, A; Aurousseau, C

    1983-01-01

    After complete destruction of cochlear but preservation of vestibular hair cells in the guinea pig acoustically evoked responses can still be recorded from the round window up to the auditory cortex. At all levels these responses differ from those observed in normal animals but their frequency sensitivity and selectivity make them akin to responses from auditory organs. In a series of experiments a complete cochlear destruction was combined with a total or partial destruction of the vestibule. After complete cochlear and vestibular hair cell destruction no acoustic response could be recorded. But in cases of total cochlear and drastic ampullar and utricular destruction together with an almost undamaged saccular sensory epithelium the same peculiar acoustic responses could be observed. These results support the hypothesis of a functional acoustic reception by the saccule in a mammal. PMID:6601354

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

    Directory of Open Access Journals (Sweden)

    S.G.Sargsyan

    2010-09-01

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

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

    OpenAIRE

    Schüz, Joachim; Steding-Jessen, Marianne; Hansen, Søren; Stangerup, Sven-Eric; Cayé-Thomasen, Per; Johansen, Christoffer

    2010-01-01

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

  14. Vestibular schwannomas: microsurgery after partial removal and stereoradiosurgery

    OpenAIRE

    Zverina, E; Betka, J; Skrivan, J; Kluh, J; Kraus, J; Lisy, J

    2009-01-01

    The aim of this work is a comparison of results in two groups: primary radical removal of vestibular schwannoma (VS) and secondary radical removal following unsuccessful partial surgery and/or gamma knife stereoradiosurgery (GKS) and assessing the favorable one. Between 1997 and 2004, 106 patients with VS were operated on, 8 (7.5%) were after previous subtotal/partial resection and/or unsuccessful GKS. All VS from both groups were microsurgically removed by the same retromastoideal approach u...

  15. Ruptured Pseudoaneurysm after Gamma Knife Surgery for Vestibular Schwannoma

    OpenAIRE

    MURAKAMI, Mamoru; KAWARABUKI, Kentaro; Inoue, Yasuo; Ohta, Tsutomu

    2015-01-01

    Ruptured aneurysms of anterior inferior cerebellar artery (AICA) after radiotherapy for vestibular schwannoma (VS) are rare, and no definite treatment has been established for distal AICA pseudoaneurysms. We describe a 61-year-old man who underwent Gamma Knife surgery (GKS) for left VS. Follow-up magnetic resonance imaging (MRI) revealed partial regression of the tumor. Twelve years after GKS, he suffered from subarachnoid hemorrhage. Initial angiogram showed no vascular lesions; second left ...

  16. Vestibular Schwannoma in Patients with Sudden Sensorineural Hearing Loss

    OpenAIRE

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

    2011-01-01

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

  17. Magnetic Vestibular Stimulation in Subjects with Unilateral Labyrinthine Disorders

    Directory of Open Access Journals (Sweden)

    BryanKevinWard

    2014-03-01

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

  18. What Really Decides the Facial Function of Vestibular Schwannoma Surgery?

    OpenAIRE

    Kim, Jin; Moon, In Seok; Jeong, Jun hui; Lee, Hyung Rok; Lee, Won Sang

    2011-01-01

    Objectives To find the main cause of facial nerve dysfunction in vestibular schwannoma (VS) surgery and review the prognosis of facial function in relation to tumor size, preoperative facial function and surgical approach. Methods We reviewed the surgical outcome of 134 patients with VS treated in our department between 1994 and 2008. All patients included in the study had postoperative facial paralysis after surgical management of their VS. There were 14 women and 7 men. The mean age was 48....

  19. Association between vestibular schwannomas and mobile phone use

    OpenAIRE

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

    2013-01-01

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

  20. Afferent diversity and the organization of central vestibular pathways

    OpenAIRE

    Goldberg, Jay M.

    2000-01-01

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

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

    OpenAIRE

    Mahadevaiah, A.; Parikh, Bhavin

    2008-01-01

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

  2. Dynamic visual acuity testing for screening patients with vestibular impairments

    OpenAIRE

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

    2012-01-01

    Dynamic visual acuity (DVA) may be a useful indicator of the function of the vestibulo-ocular reflex (VOR) but most DVA tests involve active head motion in the yaw plane. During gait the passive, vertical VOR may be more relevant and passive testing would be less likely to elicit compensatory strategies. The goal of this study was to determine if testing dynamic visual acuity during passive vertical motion of the subject would differentiate normal subjects from patients with known vestibular ...

  3. Counteracting Muscle Atrophy using Galvanic Stimulation of the Vestibular System

    Science.gov (United States)

    Fox, Robert A.; Polyakov, Igor

    1999-01-01

    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.

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

    Science.gov (United States)

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

    1994-01-01

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

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

    Science.gov (United States)

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

    2014-01-01

    Purchases are driven by consumers' product preferences and price considerations. Using caloric vestibular stimulation (CVS), we investigated the role of vestibular-affective circuits in purchase decision-making. CVS is an effective noninvasive brain stimulation method, which activates vestibular and overlapping emotional circuits (e.g., the insular cortex and the anterior cingulate cortex (ACC)). Subjects were exposed to CVS and sham stimulation while they performed two purchase decision-making tasks. In Experiment 1 subjects had to decide whether to purchase or not. CVS significantly reduced probability of buying a product. In Experiment 2 subjects had to rate desirability of the products and willingness to pay (WTP) while they were exposed to CVS and sham stimulation. CVS modulated desirability of the products but not WTP. The results suggest that CVS interfered with emotional circuits and thus attenuated the pleasant and rewarding effect of acquisition, which in turn reduced purchase probability. The present findings contribute to the rapidly growing literature on the neural basis of purchase decision-making. PMID:24600365

  6. Purchase decision-making is modulated by vestibular stimulation

    Directory of Open Access Journals (Sweden)

    Nora Preuss

    2014-02-01

    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.

  7. Vestibular Migraine in a Female With Unexpected Pregnancy

    Directory of Open Access Journals (Sweden)

    Chen

    2016-01-01

    Full Text Available Introduction In the first three months of pregnancy, 23.8% of females experience migraines, and 63.6% have episodes of dizziness, with the most frequent symptom being (35.7% vertigo. Therefore, vestibular migraine is expected to occur in pregnant women, yet studies in this regard are limited in the literature. We studied such a case in order to determine the safest treatment for patients with possible pregnancy. Case Presentation The studied case was a 37-year-old female, who had a history of migraines. She had had vestibular migraines eight times since she was 29 years old. During the second attack, she had been conservatively treated with several anti-vertigo and anti-emetic medications. Because her menses was a little out of schedule, she receive pregnancy test, and to our surprise, the test showed positive results. Afterwards, she was transferred to an obstetric hospital for prenatal examinations and had follow-ups for ten months. Eight months after delivery, the third vestibular migraine occurred. Because of lactation, she did not take any medications; vertigo continued for half a day, and dizziness remitted over the following two days. Conclusions Pregnancy is expected to occur together with vertigo in females of the childbearing age, even if they have been diagnosed with sterility. Any anti-vertiginous medication with teratogenic risk should be avoided if pregnancy is not completely excluded, antihistamine diphenhydramine (FDA class B are recommended first for symptomatic control.

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

    Directory of Open Access Journals (Sweden)

    Renato Cal

    2008-08-01

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

  9. Survival of chronically-injured neurons can be prolonged by treatment with neurotrophic factors.

    Science.gov (United States)

    Houle, J D; Ye, J H

    1999-01-01

    Axonal regeneration by chronically-injured supraspinal neurons can be enhanced by neurotrophic factor treatment at the site of injury, although the number of regenerating neurons decreases as the interval between spinal cord injury and treatment increases. This study investigated whether this decline in regenerative response could be due to continued loss of neurons during the post-injury period. Adult rats received a cervical hemisection lesion and axotomized neurons were labeled by retrograde transport of True Blue from the lesion site. Animals were killed one, four or eight weeks after injury and surviving neurons (True Blue-labeled) were counted in the red nucleus and lateral vestibular nucleus. The neuron number in the lateral vestibular nucleus was stable for eight weeks after spinal cord injury, while survival in the red nucleus decreased by 25% between four and eight weeks. To test how neurons respond to a second injury with or without trophic factor treatment, at four, eight, 14 or 22 weeks after injury the lesion cavity was enlarged by 0.5 mm in a rostral direction. Gel foam saturated with ciliary neurotrophic factor, brain-derived neurotrophic factor or basic fibroblast growth factor was placed into the cavity. Animals were killed four weeks later. Re-injury of the spinal cord caused a significant decrease in neuron survival in both the red nucleus and lateral vestibular nucleus, the effects of which were lessened by treatment with ciliary neurotrophic factor or brain-derived neurotrophic factor for the red nucleus and with ciliary neurotrophic factor for the lateral vestibular nucleus, when re-injured at four or eight weeks. Basic fibroblast growth factor did not affect neuron survival at any time post-injury. Ciliary neurotrophic factor was not effective with longer delays (14 or 22 weeks) between the initial injury and re-injury. These results indicate a delayed pattern of secondary neuronal cell loss after spinal cord injury that is exaggerated by re-injury, but which can be ameliorated by treatment with neurotrophic factors. PMID:10579585

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

    Directory of Open Access Journals (Sweden)

    Steven T Moore

    2015-06-01

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

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

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    Giancarlo Russo

    2014-12-01

    Full Text Available The function of the enzyme glutamate decarboxylase (GAD is to convert glutamate in -aminobutyric acid (GABA.GAD 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.

  12. Large basolateral processes on type II hair cells comprise a novel processing unit in mammalian vestibular organs

    OpenAIRE

    Pujol, Rémy; Pickett, Sarah B.; Nguyen, Tot Bui; Stone, Jennifer S.

    2014-01-01

    Sensory receptors in the vestibular system (hair cells) encode head movements and drive central motor reflexes that control gaze, body movements, and body orientation. In mammals, type I and II vestibular hair cells are defined by their shape, contacts with vestibular afferent nerves, and membrane conductance. Here, we describe unique morphological features of type II vestibular hair cells in mature rodents (mice and gerbils) and bats. These features are cytoplasmic processes t...

  13. [Mirror neurons].

    Science.gov (United States)

    Rubia Vila, Francisco José

    2011-01-01

    Mirror neurons were recently discovered in frontal brain areas of the monkey. They are activated when the animal makes a specific movement, but also when the animal observes the same movement in another animal. Some of them also respond to the emotional expression of other animals of the same species. These mirror neurons have also been found in humans. They respond to or "reflect" actions of other individuals in the brain and are thought to represent the basis for imitation and empathy and hence the neurobiological substrate for "theory of mind", the potential origin of language and the so-called moral instinct. PMID:23350333

  14. Effect of different modes of therapy on vestibular and balance dysfunction in Parkinson’s disease

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    Wafaa Abdel-Hay El-Kholy

    2015-07-01

    Conclusions: Since patients with PD receiving physiotherapy in conjunction with medical treatment showed better control of their vestibular and balance functions, efforts should be directed to start physiotherapy including vestibular rehabilitation as early as possible in order to improve balance, thus increasing independence in daily life activities.

  15. Vestibular loss promotes procedural response during a spatial task in rats.

    Science.gov (United States)

    Machado, Marie-Laure; Lelong-Boulouard, Véronique; Philoxene, Bruno; Davis, Audrey; Denise, Pierre; Besnard, Stéphane

    2014-05-01

    Declarative memory refers to a spatial strategy using numerous sources of sensory input information in which visual and vestibular inputs are assimilated in the hippocampus. In contrast, procedural memory refers to a response strategy based on motor skills and familiar gestures and involves the striatum. Even if vestibular loss impairs hippocampal activity and spatial memory, vestibular-lesioned rats remain able to find food rewards during complex spatial memory task. Since hippocampal lesions induce a switch from declarative memory to procedural memory, we hypothesize that vestibular-lesioned rats use a strategy other than that of hippocampal spatial response to complete the task and to counterbalance the loss of vestibular information. We test, in a reverse T-maze paradigm, the types of strategy vestibular-lesioned rats preferentially uses in a spatial task. We clearly demonstrate that all vestibular-lesioned rats shift to a response strategy to solve the spatial task, while control rats use spatial and response strategies equally. We conclude that the loss of vestibular informations leading to spatial learning impairments is not offset at the hippocampus level by integration process of other sense mainly visual informations; but favors a response strategy through procedural memory most likely involving the striatum, cerebellum, and motor learning. PMID:24464878

  16. [Preprosthetic surgery of the edentulous maxilla: vestibular deepening with the aid of the CO2 laser].

    Science.gov (United States)

    Mahler, P; Pouyssegur, V; Rocca, J-P; De Moor, R; Nammour, S

    2009-01-01

    Vestibular deepening for maxillary edentulous patients is mainly indicated once instability cannot be reached due to important bone resorption. Vestibular deepening with CO2 super-pulsed laser enhance, in a bloodless environment, sustentation as well retention of those full dentures in good operative conditions as compared with conventional techniques. PMID:19994545

  17. Vestibular autonomic regulation (including motion sickness and the mechanism of vomiting)

    Science.gov (United States)

    Balaban, C. D.

    1999-01-01

    Autonomic manifestations of vestibular dysfunction and motion sickness are well established in the clinical literature. Recent studies of 'vestibular autonomic regulation' have focused predominantly on autonomic responses to stimulation of the vestibular sense organs in the inner ear. These studies have shown that autonomic responses to vestibular stimulation are regionally selective and have defined a 'vestibulosympathetic reflex' in animal experiments. Outside the realm of experimental preparations, however, the importance of vestibular inputs in autonomic regulation is unclear because controls for secondary factors, such as affective/emotional responses and cardiovascular responses elicited by muscle contraction and regional blood pooling, have been inadequate. Anatomic and physiologic evidence of an extensive convergence of vestibular and autonomic information in the brainstem suggests though that there may be an integrated representation of gravitoinertial acceleration from vestibular, somatic, and visceral receptors for somatic and visceral motor control. In the case of vestibular dysfunction or motion sickness, the unpleasant visceral manifestations (e.g. epigastric discomfort, nausea or vomiting) may contribute to conditioned situational avoidance and the development of agoraphobia.

  18. Função cócleo-vestibular após hemisferectomias cerebrais: apresentação de dois casos

    Directory of Open Access Journals (Sweden)

    Sérgio Paula Santos

    1957-03-01

    Full Text Available O exame cócleo-vestibular de dois pacientes hemisferectomizados mostrou: hipoacusia bilateral não ultrapassando 30 db, sendo maior no ouvido contralateral; não houve recrutamento de volume; desproporção entre audiometria vocal e tonal; a função vestibular não se mostrou prejudicada pela prova calórica fria.

  19. The Effect of Galvanic Vestibular Stimulation on Postural Response of Down Syndrome Individuals on the Seesaw

    Science.gov (United States)

    Carvalho, R. L.; Almeida, G. L.

    2011-01-01

    In order to better understand the role of the vestibular system in postural adjustments on unstable surfaces, we analyzed the effects of galvanic vestibular stimulation (GVS) on the pattern of muscle activity and joint displacements (ankle knee and hip) of eight intellectually normal participants (control group--CG) and eight control group…

  20. Sympathetic Arousal to a Vestibular Stressor in High and Low Hostile Men

    Science.gov (United States)

    Carmona, Joseph E.; Holland, Alissa K.; Stratton, Harrison J.; Harrison, David W.

    2008-01-01

    The aim of the present experiment was to extend the literature on hostility and a cerebral systems based model of sympathetic arousal to a vestibular-based stress. Several authors have concluded that autonomic stress reactivity in high hostile individuals must be interpersonally based, whereas healthy vestibular system functioning does not depend…

  1. Spontaneous tumour shrinkage in 1261 observed patients with sporadic vestibular schwannoma

    DEFF Research Database (Denmark)

    Huang, Xiaoshan; Caye-Thomasen, P; Stangerup, S-E

    2013-01-01

    To determine the rate of spontaneous tumour shrinkage in a group of patients with sporadic vestibular schwannoma managed with a 'wait and scan' approach.......To determine the rate of spontaneous tumour shrinkage in a group of patients with sporadic vestibular schwannoma managed with a 'wait and scan' approach....

  2. The vestibular system: A spatial reference for bodily self-consciousness

    Directory of Open Access Journals (Sweden)

    Christian Pfeiffer

    2014-04-01

    Full Text Available Self-consciousness is the remarkable human experience of being a subject: the ‘I’. Self-consciousness is typically bound to a body, and particularly to the spatial dimensions of the body, as well as to its location and displacement in the gravitational field. Because the vestibular system codes head position in three-dimensional space, vestibular cortex is likely to contribute to spatial aspects of bodily self-consciousness. We review here recent data showing vestibular effects on first-person perspective (the feeling from where ‘I’ experience the world and self-location (the feeling where ‘I’ am located in space. We compare these findings to data showing vestibular effects on mental spatial transformation, self-motion perception, and body representation that show that vestibular signals contribute to various spatial representations of the body with respect to the external world. Finally, we discuss four posterior brain regions that process vestibular and other multisensory signals to encode spatial aspects of bodily self-consciousness: temporoparietal junction (TPJ, parietoinsular vestibular cortex (PIVC, medial superior temporal region (MST, and ventral intraparietal region (VIP. We propose that vestibular processing in these cortical regions is important for linking multisensory signals from within personal space with those from extrapersonal space, and for spatial aspects of bodily self-consciousness.

  3. 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)

    Daniela Polo Camargo da Silva

    2008-06-01

    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.

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

    OpenAIRE

    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

    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...

  5. A CMOS Neural Interface for a Multichannel Vestibular Prosthesis.

    Science.gov (United States)

    Hageman, Kristin N; Kalayjian, Zaven K; Tejada, Francisco; Chiang, Bryce; Rahman, Mehdi A; Fridman, Gene Y; Dai, Chenkai; Pouliquen, Philippe O; Georgiou, Julio; Della Santina, Charles C; Andreou, Andreas G

    2016-04-01

    We present a high-voltage CMOS neural-interface chip for a multichannel vestibular prosthesis (MVP) that measures head motion and modulates vestibular nerve activity to restore vision- and posture-stabilizing reflexes. This application specific integrated circuit neural interface (ASIC-NI) chip was designed to work with a commercially available microcontroller, which controls the ASIC-NI via a fast parallel interface to deliver biphasic stimulation pulses with 9-bit programmable current amplitude via 16 stimulation channels. The chip was fabricated in the ONSemi C5 0.5 micron, high-voltage CMOS process and can accommodate compliance voltages up to 12 V, stimulating vestibular nerve branches using biphasic current pulses up to 1.45±0.06 mA with durations as short as 10 μs/phase. The ASIC-NI includes a dedicated digital-to-analog converter for each channel, enabling it to perform complex multipolar stimulation. The ASIC-NI replaces discrete components that cover nearly half of the 2nd generation MVP (MVP2) printed circuit board, reducing the MVP system size by 48% and power consumption by 17%. Physiological tests of the ASIC-based MVP system (MVP2A) in a rhesus monkey produced reflexive eye movement responses to prosthetic stimulation similar to those observed when using the MVP2. Sinusoidal modulation of stimulus pulse rate from 68-130 pulses per second at frequencies from 0.1 to 5 Hz elicited appropriately-directed slow phase eye velocities ranging in amplitude from 1.9-16.7 (°)/s for the MVP2 and 2.0-14.2 (°)/s for the MVP2A. The eye velocities evoked by MVP2 and MVP2A showed no significant difference ( t-test, p=0.34), suggesting that the MVP2A achieves performance at least as good as the larger MVP2. PMID:25974945

  6. Vestibular and Visual Contribution to Fish Behavior Under Microgravity

    Science.gov (United States)

    Ijiri, K.

    Vestibular and visual information are two major factors fish use for controlling their posture under 1 G conditions. Parabolic flight experiments were carried out to observe the fish behavior under microgravity for several different strains of Medaka fish (Oryzias latipes). There existed a clear strain-difference in the behavioral response of the fish under microgravity: Some strains looped, while other strains did not loop at all. However, even the latter strains looped under microgravity conditions when kept in complete darkness, suggesting the contribution of visual information to the posture control under microgravity. In the laboratory, eyesight (visual acuity) was checked for each strain, using a rotating striped-drum apparatus. The results also showed a strain-difference, which gave a clue to the different degree of adaptability to microgravity among different strains. Beside loopings, some fish exhibited rolling movement around their body axis. Tracing each fish during and between parabolas, it was shown that to which side each fish rolls was determined specifically to each individual fish, and not to each strain. Thus, rolling direction is not genetically determined. This may support the otolith asymmetry hypothesis. Fish of a mutant strain (ha strain, having homozygous recessive of one gene ha) have some malfunction in otolith-vestibular system, and their behavior showed they are not dependent on gravity. Morphological abnormalities of their ear vesicles during the embryonic and baby stages were noted. Their eyesight and dorsal light responses were also studied. Progress in the project of establishing a new strain which has good eyesight and, at the same time, being deficient in otolith-vestibular system was reported. Crosses between the strain of good eyesight and ha strain were made, and to some extent, F2 fish have already shown such characteristics suited for living under microgravity conditions

  7. Trimetazidine modulates AMPA/kainate receptors in rat vestibular ganglion neurons.

    OpenAIRE

    Dayanithi, Govindan; Desmadryl, Gilles; Travo, Cécile; Chabbert, Christian; Sans, Alain

    2007-01-01

    Trimetazidine (1[2,3,4-trimethoxy-benzyl] piperazine, 2 HCl) is an anti-ischemic agent frequently administered as a prophylactic treatment for episodes of angina pectoris and chorioretinal disturbances. It is also employed as a symptomatic treatment of vertigo but its mechanism of action is yet to be defined. Using Fura-2 fluorescence photometry and whole-cell patch-clamp recordings we investigated the effect of trimetazidine on the [Ca(2+)](i) and current responses induced by the application...

  8. Vestibular-related neuroscience and manned space flight

    Science.gov (United States)

    Igarashi, Makoto

    1988-01-01

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

  9. Alignment of angular velocity sensors for a vestibular prosthesis

    Directory of Open Access Journals (Sweden)

    DiGiovanna Jack

    2012-02-01

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

  10. Influence of mobility restriction on habituation of the vestibular apparatus

    Science.gov (United States)

    Gorgiladze, G. I.; Kazanskaya, G. S.

    1980-01-01

    Test results presented indicate that 30-day hypokinesia did not affect the intensity of nystagmus: velocity of slow phase, total number of jerks, and duration of the reaction in animals were the same as before mobility restriction and did not differ from those of the control group. However, hypokinesia resulted in the disappearance of habituation of the vestibulary system to repeated angular accelerations. The known hypokinetic changes in the endocrine system were studied. It was concluded that reduction in adrenergic function may be the cause of disappearance of vestibular apparatus habituation during hypokinesia.

  11. Indications of Gamma knife radiosurgery for vestibular schwannomas

    International Nuclear Information System (INIS)

    The purpose of this study was to investigate the indication of gamma knife radiosurgery for vestibular schwannomas by analyzing tumor control and possible complications using low marginal doses and conformal multiple shots to fit irregular tumor shapes. The authors evaluated 223 patients with followed-up periods ranging from 5 years to 15 years (mean 7.7 years, median 7.4 years). Marginal doses were 9 to 15 Gy (mean 12.5 Gy, median 12 Gy) with corresponding treatment volumes being between 0.1 and 18.7 cm3 (mean 2.6 cm3, median 1.8 cm3). The number of isocenters varied from 2 to 24 shots (mean 9, median 9.2). The actuarial tumor control rates were 95% at 5 years and 94% at 7 years, respectively. Larger tumors (p=0.0068) and those in younger patients (p=0.093) tended to recur significantly. The preservation rates of useful hearing were 84%, 71%, and 64% at 2, 4, and 7 years, respectively. The most deterioration seemed to occur in cases with elderly patients (p=0.0048). Facial and trigeminal functions were preserved at 100%, and 97.8%, respectively. Amongst all patients, 20.6% developed transient dizziness, with persistent dizziness remaining in 1.5% of the total. Fifty-six other patients not in the long-term evaluation consecutively underwent caloric testing and static stabilometry as well as neurological examinations to evaluate vestibular function in detail, both before and after gamma knife radiosurgery (GKRS). The results showed that 90% of the patients had already developed vestibular dysfunction before the treatment despite reported symptoms of dizziness. GKRS did not significantly affect vestibular function. Hydrocephalus was recognized in 5.5% of all patients, and seemed to occur primarily in cases with larger tumors (p=0.0189). GKRS provides a safe and effective therapy for small to medium sized tumors up to 8 cm3. Long-term hearing preservation rate may be affected by presbycusis in elderly patients. (author)

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

    Directory of Open Access Journals (Sweden)

    Leandro Luís Martins

    2009-10-01

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

  13. Vestibular evoked myogenic potential in sudden sensorineural hearing loss

    Directory of Open Access Journals (Sweden)

    Feroze Kancharu Khan

    2013-01-01

    Full Text Available Aim and Objective: To investigate saccular damage in patients with sudden sensorineural hearing loss (SSNHL with or without vertigo and to evaluate the saccular damage according to the hearing loss and presence or absence of vertigo. Materials and Methods: All tests done in this study were performed in the audio vestibular unit of ENT department from September 2009 to November 2010. Statistical Analysis Used: The association between the severity of hearing loss and changes in the vestibular evoked myogenic potential (VEMP recordings were assessed using descriptive statistics. The pattern of VEMP in different diseases and also the behavior of VEMP in presence or absence of vertigo were evaluated using SPSS 15. Results: Among 27 patients there were 11 cases of idiopathic SSNHL. Out of nine unaffected ears, 88% had normal and 12% had absent VEMP. Whereas out of 13 affected ears, only 53.9% had normal VEMP. Among all the 54 ears, 17 ears had normal hearing. In this group 76.47% had normal VEMP. The group with hearing loss > 90 dB had 61.53% absent VEMP. Conclusions: In patients with unilateral SSNHL, there was a tendency for the affected ear to have absent VEMP indicating the saccular involvement. The extent of saccular damage did not correspond to the amount of hearing loss or presence or absence of vertigo.

  14. Early diagnosis of acoustic neuroma by the vestibular test

    Energy Technology Data Exchange (ETDEWEB)

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

    1981-11-01

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

  15. Pathogenesis of vestibular schwannoma in ring chromosome 22

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    Debiec-Rychter Maria

    2009-09-01

    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.

  16. Prevalence of hydrocephalus in 157 patients with vestibular schwannoma

    International Nuclear Information System (INIS)

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

  17. 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 insular cortex suggesting a functional de-coupling between cortical and subcortical activity during the vestibular response.

  18. 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.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

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

    Science.gov (United States)

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

    2016-03-01

    Diabetes causes many complications, including retinopathy and peripheral neuropathy, which are well understood as contributing to gait instability and falls. A less understood complication of diabetes is the effect on the vestibular system. The vestibular system contributes significantly to balance in static and dynamic conditions by providing spatially orienting information. It is noteworthy that diabetes has been reported to affect vestibular function in both animal and clinical studies. Pathophysiological changes in peripheral and central vestibular structures due to diabetes have been noted. Vestibular dysfunction is associated with impaired balance and a higher risk of falls. As the prevalence of diabetes increases, so does the potential for falls due to diabetic complications. The purpose of this perspective article is to present evidence on the pathophysiology of diabetes-related complications and their influence on balance and falls, with specific attention to emerging evidence of vestibular dysfunction due to diabetes. Understanding this relationship may be useful for screening (by physical therapists) for possible vestibular dysfunction in people with diabetes and for further developing and testing the efficacy of interventions to reduce falls in this population. PMID:26251477

  1. Dizziness handicap inventory - em um grupo de pacientes submetidos a reabilitação vestibular personalizada

    Directory of Open Access Journals (Sweden)

    Ana Carla Leite Romero

    2015-06-01

    Full Text Available OBJETIVO: investigar o impacto da Reabilitação Vestibular personalizada e comparar os aspectos físicos, emocionais e funcionais pré e pós a aplicação do Dizziness Handicap Inventory. MÉTODOS: participaram 10 pacientes, com sintomas decorrentes de distúrbios do sistema vestibular e hipótese diagnóstica de disfunção vestibular crônica. Estes foram avaliados quanto aos aspectos físicos, emocionais e funcionais por meio do Dizziness Handicap Inventory pré e pós reabilitação vestibular personalizada. RESULTADOS: no Dizziness Handicap Inventory pré foi verificado que o aspecto físico foi o mais pontuado, seguido pelo emocional e funcional. A reabilitação vestibular foi eficaz, uma vez que houve diminuição nas queixas de qualidade de vida, e melhores resultados em todos os aspectos avaliados no Dizziness Handicap Inventory pós, apenas um paciente obteve melhora somente dos aspectos emocionais e funcionais, além de piora dos aspectos físicos. CONCLUSÃO: o Dizziness Handicap Inventory brasileiro aplicado pré e pós reabilitação vestibular personalizada mostrou-se como um teste eficaz para acompanhar pacientes submetidos a reabilitação vestibular, capaz de mostrar a melhora significante nos sintomas da vertigem crônica, além do impacto negativo na qualidade de vida dos pacientes deste estudo.

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

    Directory of Open Access Journals (Sweden)

    Vahid Moradi

    2015-02-01

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

  3. 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

    Directory of Open Access Journals (Sweden)

    Ricci Natalia

    2012-12-01

    Full Text Available 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 capacity and body balance control of older people with chronic dizziness due to vestibular disorders. Methods/design A randomized, single-blind, controlled clinical trial with a 3 months follow-up period will be performed. The sample will be composed of older individuals with a clinical diagnosis of chronic dizziness resulting from vestibular disorders. The subjects will be evaluated at baseline, post-treatment and follow-up. Primary outcomes will be determined in accordance with the Dizziness Handicap Inventory (functional capacity and the Dynamic Gait Index (body balance. Secondary outcomes include dizziness features, functional records, body balance control tests, and psychological information. The older individuals (minimum sample n = 68 will be randomized to either the conventional or multimodal Cawthorne&Cooksey protocols. The protocols will be performed during individual 50-minute sessions, twice a week, for 2 months (a total of 16 sessions. The outcomes of both protocols will be compared according to the intention-to-treat analysis. Discussion Vestibular rehabilitation through the Cawthorne&Cooksey protocol has already proved to be effective. However, the addition of other components related to body balance control has been proposed to improve the rehabilitation of older people with chronic dizziness from vestibular disorders. Trial registration ACTRN12610000018011

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

    Science.gov (United States)

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

    2011-01-01

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

  5. The human vestibular cortex revealed by coordinate-based activation likelihood estimation meta-analysis.

    Science.gov (United States)

    Lopez, C; Blanke, O; Mast, F W

    2012-06-14

    The vestibular system contributes to the control of posture and eye movements and is also involved in various cognitive functions including spatial navigation and memory. These functions are subtended by projections to a vestibular cortex, whose exact location in the human brain is still a matter of debate (Lopez and Blanke, 2011). The vestibular cortex can be defined as the network of all cortical areas receiving inputs from the vestibular system, including areas where vestibular signals influence the processing of other sensory (e.g. somatosensory and visual) and motor signals. Previous neuroimaging studies used caloric vestibular stimulation (CVS), galvanic vestibular stimulation (GVS), and auditory stimulation (clicks and short-tone bursts) to activate the vestibular receptors and localize the vestibular cortex. However, these three methods differ regarding the receptors stimulated (otoliths, semicircular canals) and the concurrent activation of the tactile, thermal, nociceptive and auditory systems. To evaluate the convergence between these methods and provide a statistical analysis of the localization of the human vestibular cortex, we performed an activation likelihood estimation (ALE) meta-analysis of neuroimaging studies using CVS, GVS, and auditory stimuli. We analyzed a total of 352 activation foci reported in 16 studies carried out in a total of 192 healthy participants. The results reveal that the main regions activated by CVS, GVS, or auditory stimuli were located in the Sylvian fissure, insula, retroinsular cortex, fronto-parietal operculum, superior temporal gyrus, and cingulate cortex. Conjunction analysis indicated that regions showing convergence between two stimulation methods were located in the median (short gyrus III) and posterior (long gyrus IV) insula, parietal operculum and retroinsular cortex (Ri). The only area of convergence between all three methods of stimulation was located in Ri. The data indicate that Ri, parietal operculum and posterior insula are vestibular regions where afferents converge from otoliths and semicircular canals, and may thus be involved in the processing of signals informing about body rotations, translations and tilts. Results from the meta-analysis are in agreement with electrophysiological recordings in monkeys showing main vestibular projections in the transitional zone between Ri, the insular granular field (Ig), and SII. PMID:22516007

  6. Interdependence of spatial properties and projection patterns of medial vestibulospinal tract neurons in the cat.

    Science.gov (United States)

    Perlmutter, S I; Iwamoto, Y; Baker, J F; Peterson, B W

    1998-01-01

    Activity of vestibular nucleus neurons with axons in the ipsi- or contralateral medial vestibulospinal tract was studied in decerebrate cats during sinusoidal, whole-body rotations in many planes in three-dimensional space. Antidromic activation of axon collaterals distinguished between neurons projecting only to neck segments from those with collaterals to C6 and/or oculomotor nucleus. Secondary neurons were identified by monosynaptic activation after labyrinth stimulation. A three-dimensional maximum activation direction vector (MAD) summarized the spatial properties of 151 of 169 neurons. The majority of secondary neurons (71%) terminated above the C6 segment. Of these, 43% had ascending collaterals to the oculomotor nucleus (VOC neurons), and 57% did not (VC neurons). The majority of VOC and VC neurons projected contralaterally and ipsilaterally, respectively. Most C6-projecting neurons could not be activated from oculomotor nucleus (V-C6 neurons) and projected primarily ipsilaterally. All VO-C6 neurons projected contralaterally. The distributions of MADs for secondary neurons with different projection patterns were different. Most VOC (84%) and contralaterally projecting VC (91%) neurons had MADs close to the activation vector of a semicircular canal pair, compared with 54% of ipsilaterally projecting VC (i-VC) and 39% of V-C6 neurons. Many i-VC (44%) and V-C6 (48%) neurons had responses suggesting convergent input from horizontal and vertical canal pairs. Horizontal and vertical gains were comparable for some, making it difficult to assign a primary canal input. MADs consistent with vertical-vertical canal pair convergence were less common. Type II yaw or type II roll responses were seen for 22% of the i-VC neurons, 68% of the V-C6 neurons, and no VOC cells. VO-C6 neurons had spatial properties between those of VOC and V-C6 neurons. These results suggest that secondary VOC neurons convey semicircular canal pair signals to both ocular and neck motor centers, perhaps linking eye and head movements. Secondary VC and V-C6 neurons carry more processed signals, possibly to drive neck and forelimb reflexes more selectively. Two groups of secondary i-VC neurons exhibited vertical-horizontal canal convergence similar to that present on neck muscles. The vertical-vertical canal convergence present on many neck muscles, however, was not present on medial vestibulospinal neurons. Spatial transformations achieved by the vestibulocollic reflex may occur in part on secondary neurons but further combination of canal signals must take place to generate compensatory muscle activity. PMID:9425197

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

    Science.gov (United States)

    Noohi, F.; Kinnaird, C.; Wood, S.; Bloomberg, J.; Mulavara, A.; Seidler, R.

    2016-01-01

    The current study characterizes brain activation in response to two modes of vestibular stimulation: skull tap and auditory tone burst. The auditory tone burst has been used in previous studies to elicit either the vestibulo-spinal reflex (saccular-mediated colic Vestibular Evoked Myogenic Potentials (cVEMP)), or the ocular muscle response (utricle-mediated ocular VEMP (oVEMP)). Some researchers have reported that air-conducted skull tap elicits both saccular and utricle-mediated VEMPs, while being faster and less irritating for the subjects. However, it is not clear whether the skull tap and auditory tone burst elicit the same pattern of cortical activity. Both forms of stimulation target the otolith response, which provides a measurement of vestibular function independent from semicircular canals. This is of high importance for studying otolith-specific deficits, including gait and balance problems that astronauts experience upon returning to earth. Previous imaging studies have documented activity in the anterior and posterior insula, superior temporal gyrus, inferior parietal lobule, inferior frontal gyrus, and the anterior cingulate cortex in response to different modes of vestibular stimulation. Here we hypothesized that skull taps elicit similar patterns of cortical activity as the auditory tone bursts, and previous vestibular imaging studies. Subjects wore bilateral MR compatible skull tappers and headphones inside the 3T GE scanner, while lying in the supine position, with eyes closed. Subjects received both forms of the stimulation in a counterbalanced fashion. Pneumatically powered skull tappers were placed bilaterally on the cheekbones. The vibration of the cheekbone was transmitted to the vestibular system, resulting in the vestibular cortical response. Auditory tone bursts were also delivered for comparison. To validate our stimulation method, we measured the ocular VEMP outside of the scanner. This measurement showed that both skull tap and auditory tone burst elicited vestibular evoked myogenic potentials, indicated by eye muscle responses. We further assessed subjects' postural control and its correlation with vestibular cortical activity. Our results provide the first evidence of using skull taps to elicit vestibular activity inside the MRI scanner. By conducting conjunction analyses we showed that skull taps elicit the same activation pattern as auditory tone bursts (superior temporal gyrus), and both modes of stimulation activate previously identified vestibular cortical regions. Additionally, we found that skull taps elicit more robust vestibular activity compared to auditory tone bursts, with less reported aversive effects. This further supports that the skull tap could replace auditory tone burst stimulation in clinical interventions and basic science research. Moreover, we observed that greater vestibular activation is associated with better balance control. We showed that not only the quality of balance (indicated by the amount of body sway) but also the ability to maintain balance for a longer time (indicated by the balance time) was associated with individuals' vestibular cortical excitability. Our findings support an association between vestibular cortical activity and individual differences in balance. In sum, we found that the skull tap stimulation results in activation of canonical vestibular cortex, suggesting an equally valid, but more tolerable stimulation method compared to auditory tone bursts. This is of high importance in longitudinal vestibular assessments, in which minimizing aversive effects may contribute to higher protocol adherence.

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

    Directory of Open Access Journals (Sweden)

    Aracy Pereira Silveira Balbani

    2008-02-01

    Full Text Available Os sistemas de telecomunicações emitem radiofreqüência, uma radiação eletromagnética invisível. Telefones celulares transmitem microondas (450900 MHz no sistema analógico e 1,82,2 GHz no sistema digital, muito próximo à orelha do usuário. Esta energia é absorvida pela pele, orelha interna, nervo vestibulococlear e superfície do lobo temporal. OBJETIVO: Revisar a literatura sobre influência dos telefones celulares na audição e equilíbrio. FORMA DE ESTUDO: Revisão sistemática. METODOLOGIA: Foram pesquisados artigos nas bases Lilacs e Medline sobre a influência dos telefones celulares nos sistemas auditivo e vestibular, publicados de 2000 a 2005, e também materiais veiculados na Internet. RESULTADOS: Os estudos sobre radiação do telefone celular e risco de neurinoma do acústico apresentam resultados contraditórios. Alguns autores não encontram maior probabilidade de aparecimento do tumor nos usuários de celulares, enquanto outros relatam que a utilização de telefones analógicos por 10 anos ou mais aumenta o risco para o tumor. A exposição aguda às microondas emitidas pelo celular não influencia a atividade das células ciliadas externas da cóclea, in vivo e in vitro, a condução elétrica no nervo coclear, nem a fisiologia do sistema vestibular em humanos. As próteses auditivas analógicas são mais suscetíveis à interferência eletromagnética dos telefones celulares digitais. CONCLUSÃO: Não há comprovação de lesão cocleovestibular pelos telefones celulares.Telecommunications systems emit radiofrequency, which is an invisible electromagnetic radiation. Mobile phones operate with microwaves (450900 MHz in the analog service, and 1,82,2 GHz in the digital service very close to the user’s ear. The skin, inner ear, cochlear nerve and the temporal lobe surface absorb the radiofrequency energy. AIM: literature review on the influence of cellular phones on hearing and balance. STUDY DESIGN: systematic review. METHODS: We reviewed papers on the influence of mobile phones on auditory and vestibular systems from Lilacs and Medline databases, published from 2000 to 2005, and also materials available in the Internet. RESULTS: Studies concerning mobile phone radiation and risk of developing an acoustic neuroma have controversial results. Some authors did not see evidences of a higher risk of tumor development in mobile phone users, while others report that usage of analog cellular phones for ten or more years increase the risk of developing the tumor. Acute exposure to mobile phone microwaves do not influence the cochlear outer hair cells function in vivo and in vitro, the cochlear nerve electrical properties nor the vestibular system physiology in humans. Analog hearing aids are more susceptible to the electromagnetic interference caused by digital mobile phones. CONCLUSION: there is no evidence of cochleo-vestibular lesion caused by cellular phones.

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    1981-01-01

    Measurements are made of manual control performance in the closed-loop task of nulling perceived self-rotation velocity about an earth-vertical axis. Self-velocity estimation is modeled as a function of the simultaneous presentation of vestibular and peripheral visual field motion cues. Based on measured low-frequency operator behavior in three visual field environments, a parallel channel linear model is proposed which has separate visual and vestibular pathways summing in a complementary manner. A dual-input describing function analysis supports the complementary model; vestibular cues dominate sensation at higher frequencies. The describing function model is extended by the proposal of a nonlinear cue conflict model, in which cue weighting depends on the level of agreement between visual and vestibular cues.

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

    DEFF Research Database (Denmark)

    Møller, Martin Nue; Werther, Kim; Nalla, Amarnadh; Stangerup, Sven-Eric; Thomsen, Jens; Bøg-Hansen, Thorkild C; Nielsen, Hans Jørgen; Cayé-Thomasen, Per

    2010-01-01

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

  12. Proposed treatment for geriatric vestibular disease in dogs.

    Science.gov (United States)

    Kraeling, Margaret

    2014-03-01

    Sudden-onset vestibular dysfunction in the canine is a commonly seen condition in veterinary practice, with some veterinarians reporting several cases each month. However, traditional veterinary medicine has little to offer these patients other than symptomatic relief for the severe nausea that accompanies the vertigo and supportive advice for the owners. Owners of affected dogs are informed that these symptoms usually resolve within a few days. As physical therapists, we often see cases of benign paroxysmal positional vertigo in our human practice clinics, and effective protocols for diagnosis and treatment of the condition have been developed for this condition. A modified testing and repositioning postural maneuver used successfully on 12 canine patients in our canine rehabilitation clinic (The Canine Fitness Centre, Calgary, Alberta, Canada) is hereby described. PMID:25103883

  13. The nasal vestibular body: anatomy, clinical features, and treatment considerations.

    Science.gov (United States)

    Locketz, Garrett D; Teo, Neville W; Walgama, Evan; Humphreys, Ian M; Nayak, Jayakar V

    2016-03-01

    Nasal obstruction is a common presenting complaint, with many possible etiologies. Herein, we provide an introductory anatomic description, clinical relevance, and proposed nomenclature for an underappreciated soft tissue focus in the nasal vestibule-the nasal vestibular body (NVB)-that can contribute to nasal obstruction in a subset of patients. This is a small mound of dynamic soft tissue in the lateral aspect of the internal nasal valve, situated inferior and anterior to the head of the inferior turbinate that can be missed on routine examination for many salient reasons. In well-selected patients, whose symptoms of nasal obstruction may in part be secondary to the presence of this soft tissue focus, directed testing and tissue reduction can be performed. PMID:26825801

  14. Vestibular, proprioceptive, and haptic contributions to spatial orientation.

    Science.gov (United States)

    Lackner, James R; DiZio, Paul

    2005-01-01

    The control and perception of body orientation and motion are subserved by multiple sensory and motor mechanisms ranging from relatively simple, peripheral mechanisms to complex ones involving the highest levels of cognitive function and sensory-motor integration. Vestibular contributions to body orientation and to spatial localization of auditory and visual stimuli have long been recognized. These contributions are reviewed here along with new insights relating to sensory-motor calibration of the body gained from space flight, parabolic flight, and artificial gravity environments. Recently recognized contributions of proprioceptive and somatosensory signals to the appreciation of body orientation and configuration are described. New techniques for stabilizing posture by means of haptic touch and for studying and modeling postural mechanisms are reviewed. Path integration, place cells, and head direction cells are described along with implications for using immersive virtual environments for training geographic spatial knowledge of real environments. PMID:15709931

  15. Calcification of vestibular schwannoma: a case report and literature review

    Directory of Open Access Journals (Sweden)

    Zhang Yang

    2012-10-01

    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.

  16. Vestibular Schwannoma Presenting as Oral Dysgeusia: An Easily Missed Diagnosis

    Science.gov (United States)

    Staines, Konrad

    2016-01-01

    We present a case of a fifty-year-old male patient who was referred to the Oral Medicine Department with a complaint of a salty taste. History taking subsequently revealed that the patient was also experiencing intermittent numbness of his left lower lip, tinnitus, and a feeling of fullness in the left ear. Magnetic resonance imaging was performed which revealed a large vestibular schwannoma affecting the left vestibulocochlear nerve, which was treated surgically. This case shows the importance of taking a detailed history in a patient presenting with an initial complaint of oral dysgeusia. It also highlights the possibility of significant underlying pathology, presenting with initial low level, nonspecific complaints such as an altered taste, and the rationale for imaging patients who report unilateral facial hypoesthesia. PMID:27022490

  17. Quantitative Proteomics of Vestibular Schwannoma Cerebrospinal Fluid: A Pilot Study.

    Science.gov (United States)

    Kazemizadeh Gol, Mohammad Abraham; Lund, Troy C; Levine, Samuel C; Adams, Meredith E

    2016-05-01

    This pilot study aimed to identify candidate proteins for future study that are differentially expressed in vestibular schwannoma (VS) cerebrospinal fluid (CSF) and to compare such proteins with those previously identified in perilymph and specimen secretions. CSF was collected intraoperatively prior to removal of untreated sporadic VS (3 translabyrinthine, 3 middle cranial fossa approaches) and compared with reference CSF samples. After proteolytic digestion and iTRAQ labeling, tandem mass spectrometry with ProteinPilot was used to identify candidate proteins. Of the 237 proteins detected, 13 were dysregulated in ≥3 of the 6 VS patients versus controls, and 13 were dysregulated (12 up, 1 down) in samples from patients with class D versus class B hearing. Four perilymph proteins of interest were dysregulated in ≥1 VS CSF samples. Thus, 26 candidate VS CSF biomarkers were identified that should be considered in future VS biomarker and tumor pathophysiology investigations. PMID:26932958

  18. Focal myoclonus following vestibular concussion: A diagnostic and treatment perspective.

    Directory of Open Access Journals (Sweden)

    Nathan David Keiser

    2015-10-01

    Interventions and Outcomes: A case specific intensive multi-modal neuro-rehabilitation protocol was designed including a modified anterior canal repositioning maneuver, vestibular rehabilitation, neuromuscular reeducation, electrical stimulation and spinal manipulative thereapy over an initial 2 day period, with a 5 day follow-up after a period of two months. Post-treatment findings revealed an attenuation of his myoclonus, dizziness, arm pain and vertigo. No nystagmus was observed in occluded vision, gaze, pursuits and OKR were normal. Improvements were also seen in gait and rapid alternating movements in the upper and lower extremities among other findings. Conclusions: Utilizing findings from a functional neurological exam, an individual protocol of intensive multi-modal neuro-rehabilitation was devised and implemented. Following the execution of the protocol he had an improvement in symptomatology and neurological findings. With further investigation, it may provide a therapeutic approach for other individuals with focal myoclonus.

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

    Science.gov (United States)

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

    1986-01-01

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

  20. Adaptations of the vestibular system to short and long-term exposures to altered gravity

    Science.gov (United States)

    Bruce, L.

    Long-term space flight creates unique environmental conditions to which the vestibular system must adapt for optimal survival. We are studying two aspects of this vestibular adaptation: (1) How does long-term exposure to microgravity and hypergravity affect the development of vestibular afferents? (2) How does short- term exposure to extremely rapid changes in gravity, such as those that occur during launch and landing, affect the vestibular system. During space flight the gravistatic receptors in the otolith organs are effectively unloaded. In hypergravity conditions they are overloaded. However, the angular acceleration receptors of the semicircular canals receive relatively normal stimulation in both micro- and hypergravity.Rat embryos exposed to microgravity from gestation day 10 (prior to vestibular function) until gestation day 20 (vestibular system is somewhat functional) showed that afferents from the posterior vertical canal projecting to the medial vestibular nucleus developed similarly in microgravity, hypergravity, and in controls . However, afferents from the saccule showed delayed development in microgravity as compared to development in hypergravity and in controls. Cerebellar plasticity is crucial for modification of sensory-motor control and learning. Thus we explored the possibility that strong vestibular stimuli would modify cerebellar motor control (i.e., eye movement, postural control, gut motility) by altering the morphology of cerebellar Purkinje cells. To study the effects of short-term exposures to strong vestibular stimuli we focused on structural changes in the vestibulo-cerebellum that are caused by strong vestibular stimuli. Adult mice were exposed to various combinations of constant and/or rapidly changing angular and linear accelerations for 8.5 min (the time length of shuttle launch). Our data shows that these stimuli cause intense excitation of cerebellar Purkinje cells, inducing up-regulation of clathrin-mediated endocytosis. Different types of stimulation affect Purkinje cells in particular locations of the vestibulo-cerebellum. This system allows us to study how the vestibular environment can modify cerebellar function, allowing animals to adapt to new environments. Supported by NASA grant NAG2-1353.

  1. 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 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.

  2. Fractionated Stereotactic Radiotherapy of Vestibular Schwannomas Accelerates Hearing Loss

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-08-01

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

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

    OpenAIRE

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

    2015-01-01

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

  4. A meta-analysis of treatment of vestibular schwannoma using Gamma Knife radiosurgery

    OpenAIRE

    Rykaczewski, Bartosz; Zabek, Miroslaw

    2014-01-01

    Aim of the study One of the alternative methods of surgical treatment of vestibular schwannoma is Gamma Knife radiosurgery. The purpose of this metaanalysis was to analyze the progress in treatment of vestibular schwannoma using Gamma Knife radiosurgery based on data in the literature of the last five years. Material and methods In the collected English-language literature from the years 2007–2011, contained in 20 scientific journals, clinical articles of many years study at a single center w...

  5. Evaluation of Reported Malignant Transformation of Vestibular Schwannoma: De Novo and after Stereotactic Radiosurgery or Surgery

    OpenAIRE

    Maducdoc, MM; Ghavami, Y; Linskey, ME; Djalilian, HR

    2015-01-01

    © 2015, Otology & Neurotology, Inc. Objective To critically analyze each reported case of malignant transformation of vestibular schwannoma (VS) after either stereotactic radiosurgery (SRS) or microsurgery (MS). Data Sources We searched the Pubmed/Medline database using the relevant key words vestibular schwannoma, acoustic neuroma, malignant, transformation, radiation, induced, stereotactic, radiosurgery, malignancy, GammaKnife, and CyberKnife and combinations thereof. Study Selection Inclus...

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

    OpenAIRE

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

    2010-01-01

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

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

    OpenAIRE

    Koerbel, Andrei

    2005-01-01

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

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

    OpenAIRE

    Lystad Reidar P; Bell Gregory; Bonnevie-Svendsen Martin; Carter Catherine V

    2011-01-01

    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 vestibu...

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

    OpenAIRE

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

    2010-01-01

    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...

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

    Directory of Open Access Journals (Sweden)

    Lystad Reidar P

    2011-09-01

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

  11. Adaptations of the vestibular system to short and long-term exposures to altered gravity

    Science.gov (United States)

    Bruce, L. L.

    2003-10-01

    Long-term space flight creates unique environmental conditions to which the vestibular system must adapt for optimal survival of a given organism. The development and maintenance of vestibular connections are controlled by environmental gravitational stimulation as well as genetically controlled molecular interactions. This paper describes the effects of hypergravity on axonal growth and dendritic morphology, respectively. Two aspects of this vestibular adaptation are examined: (1) How does long-term exposure to hypergravity affect the development of vestibular axons? (2) How does short-term exposure to extremely rapid changes in gravity, such as those that occur during shuttle launch and landing, affect dendrites of the vestibulocerebellar system? To study the effects of longterm exposures to altered gravity, embryonic rats that developed in hypergravity were compared to microgravity-exposed and control rats. Examination of the vestibular projections from epithelia devoted to linear and angular acceleration revealed that the terminal fields segregate differently in rat embryos that gestated in each of the gravitational environments.To study the effects of short-term exposures to altered gravity, mice were exposed briefly to strong vestibular stimuli and the vestibulocerebellum was examined for any resulting morphological changes. My data show that these stimuli cause intense vestibular excitation of cerebellar Purkinje cells, which induce up-regulation of clathrin-mediated endocytosis and other morphological changes that are comparable to those seen in long-term depression. This system provides a basis for studying how the vestibular environment can modify cerebellar function, allowing animals to adapt to new environments.

  12. Value of clinical data and vestibular testing in a population of 101 patients with recurrent vestibulopathy

    OpenAIRE

    Mart?n-Sanz, E.; Vargas Salamanca, E.; Marqu?s Cabrero, A.; Esteban, J.; Muerte, I.; Sanz Fern?ndez, Ricardo

    2014-01-01

    Meniere?s disease is characterised by episodic vertigo, fluctuating hearing loss, aural pressure and tinnitus. Vestibular testing is not even a recommendation in the AAO-HNS guidelines, one of the most used classifications to diagnose Meniere?s disease. Vestibular migraine is a term used to describe a vertigo syndrome in patients with a history of migraines with or without aura1 that may affect up to 1% of the general population.2 In the first year after onset of sy...

  13. Asymmetric vestibular evoked myogenic potentials in unilateral Menière patients

    OpenAIRE

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

    2010-01-01

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

  14. Cochlin expression in vestibular endorgans obtained from Meniere’s disease patients

    OpenAIRE

    Calzada, Audrey P.; Lopez, Ivan A.; Parrazal, Luis Beltran; Ishiyama, Akira; Ishiyama, Gail

    2012-01-01

    The distribution of cochlin and its associated basement membrane proteins (collagen IV, collagen II, laminin-β2, and nidogen-1) was evaluated in the vestibular endorgans of subjects with Meniere’s disease and compared to normal specimens. Cochlin mRNA expression in vestibular endorgans from Meniere’s disease specimens was also investigated. Specimens were obtained from patients with Meniere’s disease who underwent ablative labyrinthectomy. Control specimens were obtained from both autopsy spe...

  15. Need for facial reanimation after operations for vestibular schwannoma: patients perspective

    DEFF Research Database (Denmark)

    Tos, Tina; Caye-Thomasen, Per; Stangerup, Sven-Eric; Thomsen, Jens; Tos, Mirko

    2003-01-01

    A total of 779 patients operated on for vestibular schwannoma mostly by the translabyrinthine approach in Denmark during the period 1976-2000 answered a questionnaire about various postoperative consequences. In this paper we describe the patients' facial function evaluated by professionals one...... Denmark. In conclusion, there seem to be a considerable and unmet need for surgical reanimation of facial function in patients with facial palsy after operations for vestibular schwannoma in Denmark....

  16. Effects of high intensity noise on the vestibular system in rats.

    Science.gov (United States)

    Stewart, Courtney; Yu, Yue; Huang, Jun; Maklad, Adel; Tang, Xuehui; Allison, Jerome; Mustain, William; Zhou, Wu; Zhu, Hong

    2016-05-01

    Some individuals with noise-induced hearing loss (NIHL) also report balance problems. These accompanying vestibular complaints are not well understood. The present study used a rat model to examine the effects of noise exposure on the vestibular system. Rats were exposed to continuous broadband white noise (0-24 kHz) at an intensity of 116 dB sound pressure level (SPL) via insert ear phones in one ear for three hours under isoflurane anesthesia. Seven days after the exposure, a significant increase in ABR threshold (43.3 ± 1.9 dB) was observed in the noise-exposed ears, indicating hearing loss. Effects of noise exposure on vestibular function were assessed by three approaches. First, fluorescein-conjugated phalloidin staining was used to assess vestibular stereocilia following noise exposure. This analysis revealed substantial sensory stereocilia bundle loss in the saccular and utricular maculae as well as in the anterior and horizontal semicircular canal cristae, but not in the posterior semicircular canal cristae. Second, single unit recording of vestibular afferent activity was performed under pentobarbital anesthesia. A total of 548 afferents were recorded from 10 noise-treated rats and 12 control rats. Noise exposure produced a moderate reduction in baseline firing rates of regular otolith afferents and anterior semicircular canal afferents. Also a moderate change was noted in the gain and phase of the horizontal and anterior semicircular canal afferent's response to sinusoidal head rotation (1 and 2 Hz, 45°/s peak velocity). Third, noise exposure did not result in significant changes in gain or phase of the horizontal rotational and translational vestibulo-ocular reflex (VOR). These results suggest that noise exposure not only causes hearing loss, but also causes substantial damage in the peripheral vestibular system in the absence of immediate clinically measurable vestibular signs. These peripheral deficits, however, may lead to vestibular disorders over time. PMID:26970474

  17. Development of a closed-loop neural prosthesis for vestibular disorders

    OpenAIRE

    Di Giovanna J.; Gong W; Haburcakova C.; Kögler V.; Carpaneto J.; Genovese V.; Merfeld D.; Demosthenous A.; Guyot J.P.; Hoffmann K.P.; Berthoz A.; Morari M.; Micera S.

    2010-01-01

    Vestibular disorders can cause severe problems including spatial disorientation, imbalance, nausea, visual blurring, and even cognitive deficits. The CLONS project is developing a closed-loop, sensory neural prosthesis to alleviate these symptoms [1]. In this article, we outline the different components necessary to develop this prosthetic. A short version of this work was presented in the NEUREL 2010 [1]. Conceptually, the prosthesis restores vestibular information based on inertial se...

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

    OpenAIRE

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

    2005-01-01

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

  19. Neuronal Migration Disorders

    Science.gov (United States)

    ... Enhancing Diversity Find People About NINDS NINDS Neuronal Migration Disorders Information Page Table of Contents (click to ... being done? Clinical Trials Organizations What are Neuronal Migration Disorders? Neuronal migration disorders (NMDs) are a group ...

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

    Directory of Open Access Journals (Sweden)

    Aline Mizuta Kozoroski Kanashiro

    2005-03-01

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

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

    Directory of Open Access Journals (Sweden)

    Maurício Malavasi Ganança

    2011-08-01

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

  2. Long-term socio-economic impact of vestibular schwannoma for patients under observation and after surgery

    DEFF Research Database (Denmark)

    Tos, Tina; Caye-Thomasen, Per; Stangerup, Sven-Eric; Tos, Mirko; Thomsen, Jens

    2003-01-01

    This study describes and compares the long-term socio-economic impact for patients diagnosed with a vestibular schwannoma and either operated on or observed. A consecutive sample of patients diagnosed with vestibular schwannoma in Denmark and either operated on (748 patients) or observed by the...... on and observed for vestibular schwannoma. However, the negative changes were more frequent among the operated patients, although the differences were surprisingly modest, especially when comparing observed patients with patients operated on for a small tumour....

  3. Premotor neurons encode torsional eye velocity during smooth-pursuit eye movements

    Science.gov (United States)

    Angelaki, Dora E.; Dickman, J. David

    2003-01-01

    Responses to horizontal and vertical ocular pursuit and head and body rotation in multiple planes were recorded in eye movement-sensitive neurons in the rostral vestibular nuclei (VN) of two rhesus monkeys. When tested during pursuit through primary eye position, the majority of the cells preferred either horizontal or vertical target motion. During pursuit of targets that moved horizontally at different vertical eccentricities or vertically at different horizontal eccentricities, eye angular velocity has been shown to include a torsional component the amplitude of which is proportional to half the gaze angle ("half-angle rule" of Listing's law). Approximately half of the neurons, the majority of which were characterized as "vertical" during pursuit through primary position, exhibited significant changes in their response gain and/or phase as a function of gaze eccentricity during pursuit, as if they were also sensitive to torsional eye velocity. Multiple linear regression analysis revealed a significant contribution of torsional eye movement sensitivity to the responsiveness of the cells. These findings suggest that many VN neurons encode three-dimensional angular velocity, rather than the two-dimensional derivative of eye position, during smooth-pursuit eye movements. Although no clear clustering of pursuit preferred-direction vectors along the semicircular canal axes was observed, the sensitivity of VN neurons to torsional eye movements might reflect a preservation of similar premotor coding of visual and vestibular-driven slow eye movements for both lateral-eyed and foveate species.

  4. Critical neurological structure sparing radiosurgery of vestibular schwannoma: Dosimetric comparison of different techniques and dose prescription methods

    Directory of Open Access Journals (Sweden)

    Shamurailatpam Dayananda Sharma

    2014-01-01

    Conclusion: This dosimetric data provides a guideline for choosing optimum treatment option and scope of inter institutional dosimetric comparison for further improvement in radiosurgery of Vestibular Schwannoma (VS.

  5. Ocular Vestibular Evoked Myogenic Potentials Using Head Striker Stimulation

    Science.gov (United States)

    De Dios, Y. E.; Gadd, N. E.; Kofman, I. S.; Peters, B. T.; Reschke, M.; Bloomberg, J. J.; Wood, S. J.; Noohibezanjani, F.; Kinnaird, C.; Seidler, R. D.; Mulavara, A. P.

    2016-01-01

    Introduction: Over the last two decades, several studies have been published on the impact of long-duration (i.e., 22 days or longer) spaceflight on the central nervous system (CNS). In consideration of the health and performance of crewmembers in flight and post-flight, we are conducting a controlled prospective longitudinal study to investigate the effects of spaceflight on the extent, longevity and neural bases of sensorimotor, cognitive, and neural changes. Multiple studies have demonstrated the effects of spaceflight on the vestibular system. One of the supporting tests conducted in this protocol is the Vestibular Evoked Myogenic Potential (VEMP) test that provides a unilateral measure of otolith (saccule and utricle) function. A different approach was taken for ocular VEMP (oVEMP) testing using a head striker system (Wackym et al. 2012). The oVEMP is generally considered to be a measure of utricle function. The the otolithic input to the inferior oblique muscle is predominately from the utricular macula. Thus, quantitatively, oVEMP tests utricular function. Another practical extension of these relationships is that the oVEMP reflects the superior vestibular nerve function. Methods: Ground testing was administered on 16 control subjects and for 8 subjects over four repeated sessions spanning 70 days. The oVEMP was elicitied via a hand held striker by a vibrotactile pulse presented at the rate of 1 Hz for 24 seconds on the side of the head as subjects lay supine on a gurney. Subjects were directed to gaze approximately 25 degrees above straight ahead in semi-darkness. For the oVEMP electromyograms will be recorded with active bipolar electrodes (Delsys Inc., Boston, MA) on the infra-orbital ridge 1 cm below the eyelid with a reference electrode on the below the knee cap. The EMG potentials were amplified; band-pass filtered using a BagnoliTM Desktop EMG System (Delsys Inc., Boston, MA, USA). This EMG signal is sampled at 10 kHz and the data stimulus onset to 100 MS was averaged over 24 trial repetitions for the vibrotactile VEMP. The typical oVEMP EMG response is an excitatory potential with first peak occurring at 11-12 ms and second peak at 18 ms. This requires a total recording time of approximately 29 seconds per trial which includes 5 seconds of no vibrotactile stimulation at the beginning of the protocol. The primary dependent measures consist of the latency and peak-to-peak amplitude from the EMG signals, which will be normalized to EMG levels at the beginning of the protocol. Data were collected for 3 repeated trials with striker stimulation on both the left and right side of the head Results: The oVEMP p1 range was observed at 3-14 ms and n1 at 7-19 ms. The striker system provided a consistent and rapid method for oVEMP testing. Discussion: Crew testing is in progress to determine changes in results between pre and post flight.

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

    Science.gov (United States)

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

    2016-04-01

    In the elderly, major complaints include dizziness and an increasing number of falls, possibly related to an altered processing of vestibular sensory input. In this study, we therefore investigate age-related changes induced by processing of vestibular sensory stimulation. While previous functional imaging studies of healthy aging have investigated brain function during task performance or at rest, we used galvanic vestibular stimulation during functional MRI in a task-free sensory stimulation paradigm to study the effect of healthy aging on central vestibular processing, which might only become apparent during stimulation processing. Since aging may affect signatures of brain function beyond the BOLD-signal amplitude-such as functional connectivity or temporal signal variability-we employed independent component analysis and partial least squares analysis of temporal signal variability. We tested for age-associated changes unrelated to vestibular processing, using a motor paradigm, voxel-based morphometry and diffusion tensor imaging. This allows us to control for general age-related modifications, possibly originating from vascular, atrophic or structural connectivity changes. Age-correlated decreases of functional connectivity and increases of BOLD-signal variability were associated with multisensory vestibular networks. In contrast, no age-related functional connectivity changes were detected in somatosensory networks or during the motor paradigm. The functional connectivity decrease was not due to structural changes but to a decrease in response amplitude. In synopsis, our data suggest that both the age-dependent functional connectivity decrease and the variability increase may be due to deteriorating reciprocal cortico-cortical inhibition with age and related to multimodal vestibular integration of sensory inputs. PMID:25567421

  7. Cortical representation of saccular vestibular stimulation: VEMPs in fMRI.

    Science.gov (United States)

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

    2008-01-01

    Short tone bursts trigger a vestibular evoked myogenic potential (VEMP), an inhibitory potential which reflects a component of the vestibulocollic reflex (VCR). These potentials arise as a result of activation of the sacculus and are expressed through the vestibulo-collic reflex (VCR). Up to now, the ascending projections of the sacculus are unknown in humans, only the representation of the semicircular canals or the entire vestibular nerve has been demonstrated. The aim of this study was to determine whether a sacculus stimulus that evoked VEMPs could activate vestibular cortical areas in fMRI. To determine this, we studied the differential effects of unilateral VEMP stimulation in 21 healthy right-handers in a clinical 1.5 T scanner while wearing piezo electric headphones. A unilateral VEMP stimulus and two auditory control stimuli were given in randomized order over the stimulated ear. A random effects statistical analysis was done with SPM2 (p<0.05, corrected). After exclusion of the auditory effects, the major findings were as follows: (i) significant activations were located in the multisensory cortical vestibular network within both hemispheres, including the posterior insular cortex, the middle and superior temporal gyri, and the inferior parietal cortex. (ii) The activation pattern was elicited bilaterally with a predominance of the right hemisphere in right-handers. (iii) Saccular vestibular projection was predominantly ipsilateral, whereas (iv) pure acoustic stimuli were processed with a predominance of the respective contralateral and mainly in the left hemisphere. This is the first demonstration by means of fMRI of the cortical representation of the saccular input at cortical level. The activation pattern is similar to that known from the stimulation of the entire vestibular nerve or the horizontal semicircular canal. Our data give evidence of a task-dependent separation of the processing within the vestibular otolith and the auditory systems in the two hemispheres. PMID:17919936

  8. The effects of the cerebral, cerebellar and vestibular systems on the head stabilization reflex.

    Science.gov (United States)

    Bademkiran, Fikret; Uludag, Burhanettin; Guler, Ayse; Celebisoy, Nese

    2016-05-01

    The head stabilization reflex (HSR) is a brain stem reflex which appears in the neck muscles in response to sudden head position changes and brings the head to its previous position. The reflex mechanism has not been understood. The afferent fibers come from cervical muscle spindles, vestibular structures, and the accessory nerve, the efferents from the accessory nerve. In this study, we aim to investigate the roles of supraspinal neural structures and the vestibular system on the HSR. The patient group consisted of 86 patients (33 cerebral cortical lesion, 14 cerebellar syndrome and 39 vestibular inexcitability or hypoexcitability); the control group was composed of 32 healthy volunteers. Concentric needle electrodes were inserted into the sternocleidomastoid muscle (SCM) and the accessory nerves were stimulated with the electrical stimulator. A reflex response of about 45-55 ms was obtained from the contralateral SCM muscle. 50 % of cases had bilateral loss whereas 37 % of cases with unilateral cerebellar lesions had an ipsilateral reflex loss. Bilateral HSR loss was detected in 84 % of cases with bilateral cerebellar lesions. Bilateral reflex loss was observed in 70 % of patients with unilateral cortical lesions and 94 % of those with bilateral vestibular dysfunction. Ipsilateral HSR loss was observed in 55 % of cases with unilateral vestibular dysfunction. It was discovered that supraspinal structures and the vestibular system may have an excitatory effect on HSR. This effect may be lost in supra-segmental and vestibular dysfunctions. The localization value of HSR was found to be rather poor in our study. PMID:26732581

  9. Vestibular implantation and longitudinal electrical stimulation of the semicircular canal afferents in human subjects.

    Science.gov (United States)

    Phillips, James O; Ling, Leo; Nie, Kaibao; Jameyson, Elyse; Phillips, Christopher M; Nowack, Amy L; Golub, Justin S; Rubinstein, Jay T

    2015-06-01

    Animal experiments and limited data in humans suggest that electrical stimulation of the vestibular end organs could be used to treat loss of vestibular function. In this paper we demonstrate that canal-specific two-dimensionally (2D) measured eye velocities are elicited from intermittent brief 2 s biphasic pulse electrical stimulation in four human subjects implanted with a vestibular prosthesis. The 2D measured direction of the slow phase eye movements changed with the canal stimulated. Increasing pulse current over a 0-400 μA range typically produced a monotonic increase in slow phase eye velocity. The responses decremented or in some cases fluctuated over time in most implanted canals but could be partially restored by changing the return path of the stimulation current. Implantation of the device in Meniere's patients produced hearing and vestibular loss in the implanted ear. Electrical stimulation was well tolerated, producing no sensation of pain, nausea, or auditory percept with stimulation that elicited robust eye movements. There were changes in slow phase eye velocity with current and over time, and changes in electrically evoked compound action potentials produced by stimulation and recorded with the implanted device. Perceived rotation in subjects was consistent with the slow phase eye movements in direction and scaled with stimulation current in magnitude. These results suggest that electrical stimulation of the vestibular end organ in human subjects provided controlled vestibular inputs over time, but in Meniere's patients this apparently came at the cost of hearing and vestibular function in the implanted ear. PMID:25652917

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-12-15

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

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

    Directory of Open Access Journals (Sweden)

    Lilian Felipe

    2005-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Angela Cristina Calciolari

    2002-11-01

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

  14. Rat thalamic neurons encode complex combinations of heading and movement directions and the trajectory route during translocation with sensory conflict

    Directory of Open Access Journals (Sweden)

    Nyamdavaa Enkhjargal

    2014-07-01

    Full Text Available It is unknown how thalamic head direction neurons extract meaningful information from multiple conflicting sensory information sources when animals run under conditions of sensory mismatch. In the present study, rats were placed on a treadmill on a stage that moved in a figure-8-shaped pathway. The anterodorsal and laterodorsal neurons were recorded under 2 conditions: 1 control sessions, in which both the stage and the treadmill moved forward, or 2 backward (mismatch sessions, in which the stage was moved backward while the rats ran forward on the treadmill. Of the 222 thalamic neurons recorded, 55 showed differential responses to the directions to window (south and door (north sides, along which the animals were translocated in the long axis of the trajectory. Of these 55 direction-related neurons, 15 showed heading direction-dependent responses regardless of movement direction (forward or backward movements. Thirteen neurons displayed heading and movement direction-dependent responses, and, of these 13, activity of 6 neurons increased during forward movement to the window or door side, while activity of the remaining 7 neurons increased during backward movement to the window or door side. Eighteen neurons showed movement direction-related responses regardless of heading direction. Furthermore, activity of some direction-related neurons increased only in a specific trajectory. These results suggested that the activity of these neurons reflects complex combinations of facing direction (landmarks, movement direction (optic flow/vestibular information, motor/proprioceptive information and the trajectory of the movement.

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

    Science.gov (United States)

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

    2002-01-01

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

  16. Temporoparietal encoding of space and time during vestibular-guided orientation

    Science.gov (United States)

    Kaski, Diego; Quadir, Shamim; Nigmatullina, Yuliya; Malhotra, Paresh A.; Bronstein, Adolfo M.

    2016-01-01

    When we walk in our environment, we readily determine our travelled distance and location using visual cues. In the dark, estimating travelled distance uses a combination of somatosensory and vestibular (i.e. inertial) cues. The observed inability of patients with complete peripheral vestibular failure to update their angular travelled distance during active or passive turns in the dark implies a privileged role for vestibular cues during human angular orientation. As vestibular signals only provide inertial cues of self-motion (e.g. velocity, °/s), the brain must convert motion information to distance information (a process called ‘path integration’) to maintain our spatial orientation during self-motion in the dark. It is unknown, however, what brain areas are involved in converting vestibular-motion signals to those that enable such vestibular-spatial orientation. Hence, using voxel-based lesion–symptom mapping techniques, we explored the effect of acute right hemisphere lesions in 18 patients on perceived angular position, velocity and motion duration during whole-body angular rotations in the dark. First, compared to healthy controls’ spatial orientation performance, we found that of the 18 acute stroke patients tested, only the four patients with damage to the temporoparietal junction showed impaired spatial orientation performance for leftward (contralesional) compared to rightward (ipsilesional) rotations. Second, only patients with temporoparietal junction damage showed a congruent underestimation in both their travelled distance (perceived as shorter) and motion duration (perceived as briefer) for leftward compared to rightward rotations. All 18 lesion patients tested showed normal self-motion perception. These data suggest that the cerebral cortical regions mediating vestibular-motion (‘am I moving?’) and vestibular-spatial perception (‘where am I?’) are distinct. Furthermore, the congruent contralesional deficit in time (motion duration) and position perception, seen only in temporoparietal junction patients, may reflect a common neural substrate in the temporoparietal junction that mediates the encoding of motion duration and travelled distance during vestibular-guided navigation. Alternatively, the deficits in timing and spatial orientation with temporoparietal junction lesions could be functionally linked, implying that the temporoparietal junction may act as a cortical temporal integrator, combining estimates of self-motion velocity over time to derive an estimate of travelled distance. This intriguing possibility predicts that timing abnormalities could lead to spatial disorientation. PMID:26719385

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

    Science.gov (United States)

    Denise, Pr Pierre

    As gravity is a direct and permanent stress on body fluids, muscles and bones, it is not surpris-ing that weightlessness has important effects on cardiovascular and musculo-skeletal systems. However, these harmful effects do not totally result from the removal of the direct stress of gravity on these organs, but are also partially and indirectly mediated by the vestibular sys-tem. Besides its well known crucial role in spatial orientation and postural equilibrium, it is now clear that the vestibular system is also involved in the regulation of other important physi-ological systems: respiratory and cardiovascular systems, circadian regulation, food intake and even bone mineralization. The neuroanatomical substrate for these vestibular-mediated reg-ulations is still poorly defined, but there is much evidence that vestibular system has strong impacts not only on brainstem autonomic centers but on many hypothalamic nuclei as well. As autonomic nervous system controls almost all body organs, bringing into play the vestibular system by hypergravity or microgravity could virtually affects all major physiological func-tions. There is experimental evidence that weightlessness as well as vestibular lesion induce sympathetic activation thus participating in space related physiological alterations. The fact that some effects of weightlessness on biological systems are mediated by the vestibular system has an important implication for using artificial gravity as a countermeasure: artificial gravity should load not only bones and the cardiovascular system but the vestibular system as well. In short-arm centrifuges, the g load at the head level is low because the head is near the axis of rotation. If the vestibular system is involved in cardiovascular deconditioning and bone loss during weightlessness, it would be more effective to significantly stimulate it and thus it would be necessary to place the head off-axis. Moreover, as the otolithic organs are non longer stimu-lated in term of gravity during space flight, and because of the plasticity of the brain, it might be possible that their inputs be progressively interpreted as resulting from translational move-ment with no gravity related activation. Therefore, on return to Earth the effect of the otoliths on cardiovascular regulation might be temporarily lost leading to orthostatic intolerance.

  18. Ruptured Pseudoaneurysm after Gamma Knife Surgery for Vestibular Schwannoma.

    Science.gov (United States)

    Murakami, Mamoru; Kawarabuki, Kentaro; Inoue, Yasuo; Ohta, Tsutomu

    2016-01-15

    Ruptured aneurysms of anterior inferior cerebellar artery (AICA) after radiotherapy for vestibular schwannoma (VS) are rare, and no definite treatment has been established for distal AICA pseudoaneurysms. We describe a 61-year-old man who underwent Gamma Knife surgery (GKS) for left VS. Follow-up magnetic resonance imaging (MRI) revealed partial regression of the tumor. Twelve years after GKS, he suffered from subarachnoid hemorrhage. Initial angiogram showed no vascular lesions; second left vertebral angiogram, 10 days after admission, demonstrated a pseudoaneurysm in the lateral pontine segment of the left AICA. The proximal portion of the AICA was occluded by a coil. Postoperative MRI revealed an infarction on the left side of the pons and brachium pontis. Although the patient suffered from mild postoperative cerebellar ataxia and facial and abducens nerve palsy, he was discharged 1 month postoperatively requiring no assistance with activities of daily living. Twelve months later, he recovered satisfactorily with a modified Rankin Scale grade of 1, and no recanalization of the aneurysm was found on MR angiography. Endovascular parent artery occlusion for ruptured aneurysms at distal AICA carries the risk of brain stem infarction, but should be considered when no other option is available such as after radiotherapy for VS. PMID:26667081

  19. Ruptured Pseudoaneurysm after Gamma Knife Surgery for Vestibular Schwannoma

    Science.gov (United States)

    MURAKAMI, Mamoru; KAWARABUKI, Kentaro; INOUE, Yasuo; OHTA, Tsutomu

    2016-01-01

    Ruptured aneurysms of anterior inferior cerebellar artery (AICA) after radiotherapy for vestibular schwannoma (VS) are rare, and no definite treatment has been established for distal AICA pseudoaneurysms. We describe a 61-year-old man who underwent Gamma Knife surgery (GKS) for left VS. Follow-up magnetic resonance imaging (MRI) revealed partial regression of the tumor. Twelve years after GKS, he suffered from subarachnoid hemorrhage. Initial angiogram showed no vascular lesions; second left vertebral angiogram, 10 days after admission, demonstrated a pseudoaneurysm in the lateral pontine segment of the left AICA. The proximal portion of the AICA was occluded by a coil. Postoperative MRI revealed an infarction on the left side of the pons and brachium pontis. Although the patient suffered from mild postoperative cerebellar ataxia and facial and abducens nerve palsy, he was discharged 1 month postoperatively requiring no assistance with activities of daily living. Twelve months later, he recovered satisfactorily with a modified Rankin Scale grade of 1, and no recanalization of the aneurysm was found on MR angiography. Endovascular parent artery occlusion for ruptured aneurysms at distal AICA carries the risk of brain stem infarction, but should be considered when no other option is available such as after radiotherapy for VS. PMID:26667081

  20. Vestibular Schwannoma in Patients with Sudden Sensorineural Hearing Loss

    Science.gov (United States)

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

    2010-01-01

    Sudden sensorineural hearing loss (SSNHL) has several etiologies. It may be a presenting symptom of vestibular schwannoma (VS). This study aimed to establish the incidence of VS in patients with SSNHL, and we report several unusual cases among these patients. We reviewed retrospectively the charts and magnetic resonance imaging (MRI) findings of all adult patients who presented with SSNHL between 2002 and 2008. We utilized three-dimensional fast imaging with steady-state acquisition temporal MRI as a screening method. Of the 295 patients with SSNHL, VS was found in 12 (4%). All patients had intrameatal or small to medium-sized tumors. There were three cases with SSNHL in one ear and an incidental finding of intracanalicular VS in the contralateral ear. There were four cases of VS that showed good recovery from SSNHL with corticosteroid treatment. There were two cases that mimicked labyrinthitis with hearing loss and vertigo. A greater number of cases than expected of VS were detected in patients with SSNHL, as a result of increasing widespread use of MRI. Various unusual findings in these patients were identified. MRI would seem to be mandatory in all cases of SSNHL. PMID:22451804

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

    Directory of Open Access Journals (Sweden)

    Bento, Ricardo Ferreira

    2012-01-01

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

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

    Science.gov (United States)

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

    2003-01-01

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

  3. Socio-demographic distribution of vestibular schwannomas in Denmark

    DEFF Research Database (Denmark)

    Stepanidis, Karen; Kessel, Marie; Caye-Thomasen, Per; Stangerup, Sven-Eric

    2014-01-01

    CONCLUSION: Vestibular schwannomas (VSs) are diagnosed less frequently in the remote parts of Denmark, whereas the diagnostic age and tumor size is the same across the different socio-demographic areas of Denmark. OBJECTIVE: To determine whether VSs are diagnosed equally often in different socio-demographic...... definitions of socio-demographic areas elaborated by Demarks Statistic. RESULTS: The mean national incidence increased almost linearly over the time period from 6.1 per million per year in the first period from 1976 to 1984, to 22.1 per million per year in the last period from 2003 to 2012. There was a lower...... incidence at the end of the period in the remote areas compared with the other socio-demographic areas (1976-1984, p = 0.05 and 2003-2011, p = 0.001). The mean age at diagnosis increased during the period, from 52.6 years in the first period to 58.6 years in the last period. There was no significant...

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

    Directory of Open Access Journals (Sweden)

    Teasdale Normand

    2007-08-01

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

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

    Science.gov (United States)

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

    2008-10-17

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

  6. Reabilitação vestibular: tendências e indicações

    Directory of Open Access Journals (Sweden)

    Clarissa Stefani Teixeira

    2010-08-01

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

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

    Science.gov (United States)

    Tighilet, Brahim; Mourre, Christiane; Lacour, Michel

    2014-01-01

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

  8. Pharmacotherapy of vestibular and cerebellar disorders and downbeat nystagmus: translational and back-translational research.

    Science.gov (United States)

    Strupp, Michael; Zwergal, Andreas; Feil, Katharina; Bremova, Tatiana; Brandt, Thomas

    2015-04-01

    There are currently eight groups of drugs for the pharmacotherapy of vertigo, nystagmus, and cerebellar disorders: antiemetics; anti-inflammatories, antimenieres, and antimigraineous medications; antidepressants, anticonvulsants, aminopyridines, and acetyl-DL-leucine ("the eight A's"). In acute unilateral vestibulopathy, corticosteroids improve the recovery of peripheral vestibular function, but there is not sufficient current evidence for a general recommendation. There is also insufficient evidence that 48 or 144 mg/day betahistine has an effect in Ménière's disease. Therefore, higher dosages are currently recommended; in animal studies, it was shown that betahistine increases cochlear blood flow. In vestibular paroxysmia, oxcarbazepine was effective (one yet not randomized controlled trial (RCT)). Aminopyridines are recommended for the treatment of downbeat nystagmus (two RCTs) and episodic ataxia type 2 (EA2, one RCT). There are so far no RCTs on vestibular migraine, so currently no treatment can be recommended. Acetyl-dl-leucine improves cerebellar ataxia (three observational studies); it also accelerates central compensation in an animal model of acute unilateral lesion, but RCTs were negative. There are ongoing RCTs on vestibular paroxysmia with carbamazepine (VESPA), acute unilateral vestibulopathy with betahistine (BETAVEST), vestibular migraine with metoprolol (PROVEMIG), benign paroxysmal positional vertigo with vitamin D (VitD@BPPV), EA2 with 4-aminopyridine versus acetazolamide (EAT-2-TREAT), and cerebellar ataxias with acetyl-DL-leucine (ALCAT). PMID:25903394

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

    Science.gov (United States)

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

    2006-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Pandey Rakesh

    2009-11-01

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

  11. Cervical and ocular vestibular evoked myogenic potentials test results in individuals with auditory neuropathy spectrum disorders

    Directory of Open Access Journals (Sweden)

    Sujeet Kumar Sinha

    2013-01-01

    Full Text Available “Auditory neuropathy spectrum disorder” is a clinical disorder where the outer hair cell functioning is intact but the functioning of the auditory nerve is affected. Since, the 8th nerve is constituted by both the auditory and vestibular branch of nerve fibers, there are chances that the vestibular nerve might also be affected. Hence, the current study was carried out in order to determine the functioning of vestibular nerve in individuals with Auditory Neuropathy. A total of 11 participants were considered for the current study. cVEMPs and oVEMPs were administered using the conventional protocol. In all the participants (100% the oVEMPs were absent whereas in 2 ears out of 22 ears tested (90.90% the cVEMPs were absent. The results of the present study indicate a high incidence of vestibular involvement in individuals with auditory neuropathy spectrum disorders. Also, it necessitates the inclusion of vestibular tests in the test battery used to assess individuals with auditory neuropathy spectrum disorder.

  12. Sympathetic preganglionic efferent and afferent neurons mediated by the greater splanchnic nerve in rabbit

    Science.gov (United States)

    Torigoe, Yasuhiro; Cernucan, Roxana D.; Nishimoto, Jo Ann S.; Blanks, Robert H. I.

    1985-01-01

    As a part of the study of the vestibular-autonomic pathways involved in motion sickness, the location and the morphology of preganglionic sympathetic neurons (PSNs) projecting via the greater splanchnic nerve were examined. Retrograde labeling of neurons was obtained by application of horseradish peroxidase to the cut end of the greater splanchnic nerve. Labeled PSNs were found, ipsilaterally, within the T1 to T11 spinal cord segments, with the highest density of neurons in T6. Most PSNs were located within the intermediolateral column, but a significant portion also occurred within the lateral funiculus, the intercalated region, and the central autonomic area; the proportion of labeling between the four regions depended on the spinal cord segment.

  13. Long-term socio-economic impact of vestibular schwannoma for patients under observation and after surgery

    DEFF Research Database (Denmark)

    Tos, Tina; Caye-Thomasen, Per; Stangerup, Sven-Eric; Tos, Mirko; Thomsen, Jens

    2003-01-01

    This study describes and compares the long-term socio-economic impact for patients diagnosed with a vestibular schwannoma and either operated on or observed. A consecutive sample of patients diagnosed with vestibular schwannoma in Denmark and either operated on (748 patients) or observed by the w...

  14. Properties of cerebellar fastigial neurons during translation, rotation, and eye movements

    Science.gov (United States)

    Shaikh, Aasef G.; Ghasia, Fatema F.; Dickman, J. David; Angelaki, Dora E.

    2005-01-01

    The most medial of the deep cerebellar nuclei, the fastigial nucleus (FN), receives sensory vestibular information and direct inhibition from the cerebellar vermis. We investigated the signal processing in the primate FN by recording single-unit activities during translational motion, rotational motion, and eye movements. Firing rate modulation during horizontal plane translation in the absence of eye movements was observed in all non-eye-movement-sensitive cells and 26% of the pursuit eye-movement-sensitive neurons in the caudal FN. Many non-eye-movement-sensitive cells recorded in the rostral FN of three fascicularis monkeys exhibited convergence of signals from both the otolith organs and the semicircular canals. At low frequencies of translation, the majority of these rostral FN cells changed their firing rates in phase with head velocity rather than linear acceleration. As frequency increased, FN vestibular neurons exhibited a wide range of response dynamics with most cells being characterized by increasing phase leads as a function of frequency. Unlike cells in the vestibular nuclei, none of the rostral FN cells responded to rotational motion alone, without simultaneously exhibiting sensitivity to translational motion. Modulation during earth-horizontal axis rotation was observed in more than half (77%) of the neurons, although with smaller gains than during translation. In contrast, only 47% of the cells changed their firing rates during earth-vertical axis rotations in the absence of a dynamic linear acceleration stimulus. These response properties suggest that the rostral FN represents a main processing center of otolith-driven information for inertial motion detection and spatial orientation.

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

    Directory of Open Access Journals (Sweden)

    Aline Cabral de Oliveira

    2008-10-01

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

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

    DEFF Research Database (Denmark)

    Schüz, Joachim; Steding-Jessen, Marianne; Hansen, Søren; Stangerup, Sven-Eric; Cayé-Thomasen, Per; Poulsen, Aslak Harbo; Olsen, Hans Jørgen; Johansen, Christoffer

    2011-01-01

    Vestibular schwannomas grow in the region within the brain where most of the energy by radiofrequency electromagnetic fields from using mobile phones is absorbed. The authors used 2 Danish nationwide cohort studies, one a study of all adult Danes subscribing for a mobile phone in 1995 or earlier...... and one on sociodemographic factors and cancer risk, and followed subjects included in both cohorts for occurrence of vestibular schwannoma up to 2006 inclusively. In this study including 2.9 million subjects, a long-term mobile phone subscription of ≥11 years was not related to an increased...... vestibular schwannoma risk in men (relative risk estimate = 0.87, 95% confidence interval: 0.52, 1.46), and no vestibular schwannoma cases among long-term subscribers occurred in women versus 1.6 expected. Vestibular schwannomas did not occur more often on the right side of the head, although the majority of...

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

    DEFF Research Database (Denmark)

    Schüz, Joachim; Steding-Jessen, Marianne; Hansen, Søren; Stangerup, Sven-Eric; Cayé-Thomasen, Per; Poulsen, Aslak Harbo; Olsen, Hans Jørgen; Johansen, Christoffer

    2011-01-01

    Vestibular schwannomas grow in the region within the brain where most of the energy by radiofrequency electromagnetic fields from using mobile phones is absorbed. The authors used 2 Danish nationwide cohort studies, one a study of all adult Danes subscribing for a mobile phone in 1995 or earlier...... and one on sociodemographic factors and cancer risk, and followed subjects included in both cohorts for occurrence of vestibular schwannoma up to 2006 inclusively. In this study including 2.9 million subjects, a long-term mobile phone subscription of =11 years was not related to an increased...... vestibular schwannoma risk in men (relative risk estimate = 0.87, 95% confidence interval: 0.52, 1.46), and no vestibular schwannoma cases among long-term subscribers occurred in women versus 1.6 expected. Vestibular schwannomas did not occur more often on the right side of the head, although the majority of...

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

    Directory of Open Access Journals (Sweden)

    McCall Andrew A

    2009-06-01

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

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

    Science.gov (United States)

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

    2001-01-01

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

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    BACKGROUND:: As only a limited proportion of vestibular schwannomas display growth following diagnosis, an increasing number of patients are managed conservatively. Tumor growth during "wait and scan" may, however, necessitate surgery. In these cases, increased tumor size is likely to increase the...... diagnosed with a vestibular schwannoma 20mm extrameatal or smaller were included. 419 patients were operated soon after diagnosis and 959 patients were initially managed conservatively. In the latter group, 161 patients were subsequently operated due to tumor growth. RESULTS:: All conservatively managed...... patients allocated primarily to conservative management, good facial function was found in 97%, which was significantly better than the result for primary operation (87%). CONCLUSION:: Overall, conservative management of small to medium-sized vestibular schwannomas is the best option with regard to...

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

    Science.gov (United States)

    Mulavara, Ajitkumar; Ruttley, Tara; Cohen, Helen; Peters, Brian; Miller, Chris; Brady, Rachel; Merkle, Lauren; Bloomberg, Jacob

    2010-01-01

    Exposure to the microgravity conditions of space flight induces adaptive modification in the control of vestibular-mediated reflexive head movement during locomotion after space flight. Space flight causes astronauts to be exposed to somatosensory adaptation in both the vestibular and body load-sensing (BLS) systems. The goal of these studies was to examine the contributions of vestibular and BLS-mediated somatosensory influences on head movement control during locomotion after long-duration space flight. Subjects were asked to walk on a treadmill driven at 1.8 m/s while performing a visual acuity task. Data were collected using the same testing protocol from three independent subject groups; 1) normal subjects before and after exposure to 30 minutes of 40% bodyweight unloaded treadmill walking, 2) bilateral labyrinthine deficient (LD) patients and 3) astronauts who performed the protocol before and after long duration space flight. Motion data from head and trunk segmental motion data were obtained to calculate the angular head pitch (HP) movements during walking trials while subjects performed the visual task, to estimate the contributions of vestibular reflexive mechanisms in HP movements. Results showed that exposure to unloaded locomotion caused a significant increase in HP movements, whereas in the LD patients the HP movements were significantly decreased. Astronaut subjects results showed a heterogeneous response of both increases and decreases in the amplitude of HP movement. We infer that BLS-mediated somatosensory input centrally modulates vestibular input and can adaptively modify head-movement control during locomotion. Thus, space flight may cause a central adaptation mediated by the converging vestibular and body load-sensing somatosensory systems.

  2. Optokinetic circular vection: a test of visual-vestibular conflict models of vection nascensy.

    Science.gov (United States)

    Jürgens, R; Kliegl, K; Kassubek, J; Becker, W

    2016-01-01

    The propensity to experience circular vection (the illusory perception of self-turning evoked by a rotating scene, CV) as reflected by its onset latency exhibits considerable interindividual variation. Models of CV nascensy have linked this delay to the time it takes the visual-vestibular conflict to disappear. One line of these "conflict models" (Zacharias and Young in Exp Brain Res 41:159-171, 1981) predicts that, across individuals, CV latency (CVL) correlates positively with the vestibular time constant (TC) and negatively with the vestibular motion detection threshold (vTHR). A second type of models (Mergner et al. in Arch Ital Biol 138:139-166, 2000) predicts only an increase in CVL with TC. We here examine which of these predictions can be experimentally substantiated. Also, we ask whether the relative weight W O of the optokinetic contribution to the perception of real self-turning could also be a factor influencing CVL. We conducted 5 experiments in 29 subjects measuring: (1) CVL, (2) the TCs of velocity perception and of accompanying nystagmus during rotation in darkness and (3) likewise for displacement perception, (4) vTHR, and (5) W O as revealed by discordant visual-vestibular stimulation. CVL correlated with the nystagmus TC recorded during velocity estimation but with none of the other vestibular TCs nor with vTHR. Confirming earlier findings, CVL shortened with rising scene velocity. Finally, CVL correlated inversely with W O: the larger an individual's optokinetic weight, the shorter was his CVL. Taken together, our data favour the second type of models which invoke an antagonism between CV inhibition by the optokinetic-vestibular conflict and disinhibition by optokinetic stimulation. Idiosyncratic factors appear to strongly modulate the balance between inhibition and disinhibition, thus increasing CVL variability and obscuring the expected relation between CVL and TC. PMID:26358128

  3. Vestibular stimulation after head injury: effect on reaction times and motor speech parameters

    DEFF Research Database (Denmark)

    Engberg, A

    1989-01-01

    Earlier studies by other authors indicate that vestibular stimulation may improve attention and dysarthria in head injured patients. In the present study of five severely head injured patients and five controls, the effect of vestibular stimulation on reaction times (reflecting attention) and some...... motor speech parameters (reflecting dysarthria) was investigated. After eight weeks with regular stimulation, it was concluded that reaction time changes were individual and consistent for a given subject. Only occasionally were they shortened after stimulation. However, reaction time was lengthened in...

  4. Efficacy of Stochastic Vestibular Stimulation to Improve Locomotor Performance in a Discordant Sensory Environment

    Science.gov (United States)

    Temple, David R.; De Dios, Yiri E.; Layne, Charles S.; Bloomberg, Jacob J.; Mulavara, Ajitkumar P.

    2016-01-01

    Astronauts exposed to microgravity face sensorimotor challenges incurred when readapting to a gravitational environment. Sensorimotor Adaptability (SA) training has been proposed as a countermeasure to improve locomotor performance during re-adaptation, and it is suggested that the benefits of SA training may be further enhanced by improving detection of weak sensory signals via mechanisms such as stochastic resonance when a non-zero level of stochastic white noise based electrical stimulation is applied to the vestibular system (stochastic vestibular stimulation, SVS). The purpose of this study was to test the efficacy of using SVS to improve short-term adaptation in a sensory discordant environment during performance of a locomotor task.

  5. Maslow's Hierarchy of Needs and the individual with chronic vestibular dysfunction.

    Science.gov (United States)

    Haybach, P J

    1994-01-01

    Individuals with chronic vestibular dysfunction may have unmet physiological or safety needs on a chronic basis. Their inability to fulfill the basic needs and progress to higher needs can lead to a patient population with many psychosocial problems. Very often such problems are ignored or unrecognized or are misdiagnosed, and treated inappropriately. This disruption in the individual's life can lead to an inability to progress as a human being. Nursing assessment and appropriate interventions should be developed to treat psychosocial problems in this patient population. The nursing profession should serve patients with vestibular dysfunction through direct care, teaching, counseling, support group facilitation, and research into appropriate interventions. PMID:8564758

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

    Science.gov (United States)

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

    2015-01-01

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

  7. Altered Phenotype of the Vestibular Organ in GLAST-1 Null Mice

    OpenAIRE

    Schraven, Sebastian P; Franz, Christoph; Rüttiger, Lukas; Löwenheim, Hubert; Lysakowski, Anna; Stoffel, Wilhelm; Knipper, Marlies

    2012-01-01

    Various studies point to a crucial role of the high-affinity sodium-coupled glutamate aspartate transporter GLAST-1 for modulation of excitatory transmission as shown in the retina and the CNS. While 2–4-month-old GLAST-1 null mice did not show any functional vestibular abnormality, we observed profound circling behavior in older (7 months) animals lacking GLAST-1. An unchanged total number of otoferlin-positive vestibular hair cells (VHCs), similar ribbon numbers in VHCs, and an unchanged VG...

  8. The vestibular implant: Frequency-dependency of the electrically evoked Vestibulo-Ocular Reflex in humans

    Directory of Open Access Journals (Sweden)

    Raymond Van De Berg

    2015-01-01

    A strong and significant effect of frequency was observed in the total peak eye velocity of the eVOR. This effect was similar to that observed in the “natural” VOR. Other characteristics of the (eVOR (angle, habituation-index, and asymmetry showed no significant frequency-dependent effect. In conclusion, this study demonstrates that, at least at the specific (limited frequency range tested, responses elicited by a vestibular implant closely mimic the frequency-dependency of the “normal” vestibular system.

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

    OpenAIRE

    Wangemann, Philine

    2013-01-01

    The human gene SLC26A4 and the mouse ortholog Slc26a4 code for the protein pendrin, which is an anion exchanger expressed in apical membranes of selected epithelia. In the inner ear, pendrin is expressed in the cochlea, the vestibular labyrinth and the endolymphatic sac. Loss-of-function and hypo-functional mutations cause an enlargement of the vestibular aqueduct (EVA) and sensorineural hearing loss. The relatively high prevalence of SLC26A4 mutations provides a strong imperative to develop ...

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

    Science.gov (United States)

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

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

  11. The role of radiology in the diagnosis and management of vestibular schwannoma

    International Nuclear Information System (INIS)

    The most frequent lesion identified at the cerebellopontine angle cistern and internal auditory meatus (IAM) is the vestibular schwannoma. Radiological features, the role of imaging in screening and follow-up, therapeutic approaches and appearances following treatment will be discussed. Other cerebellopontine angle lesions will be illustrated and an algorithm presented to help in the imaging differential diagnosis. Whilst lesions other than vestibular schwannomas are rarely isolated to the IAM, the key clinical and radiological features that should raise the possibility of alternative neoplastic and inflammatory diseases will be highlighted.

  12. Change in hearing during 'wait and scan' management of patients with vestibular schwannoma

    DEFF Research Database (Denmark)

    Stangerup, Sven-Eric; Caye-Thomasen, P.; Tos, M.; Thomsen, J.

    2008-01-01

    Aim: To evaluate hearing changes during 'wait and scan' management of patients with vestibular schwannoma. Subjects: Over a 10-year period, 636 patients have prospectively been allocated to 'wait and scan' management, with annual magnetic resonance scanning and audiological examination. Results: At...... surgery and of radiation therapy with those of 'wait and scan' management, it appears that, in vestibular schwannoma patients with a small tumour and normal speech discrimination, the main indication for active treatment should be established tumour growth Udgivelsesdato: 2008/7...

  13. The role of radiology in the diagnosis and management of vestibular schwannoma

    Energy Technology Data Exchange (ETDEWEB)

    Sriskandan, N., E-mail: neshe@doctors.org.u [Department of Radiology, Guy' s and St Thomas' NHS Foundation Trust, London (United Kingdom); Connor, S.E.J. [Department of Radiology, Guy' s and St Thomas' NHS Foundation Trust, London (United Kingdom); Department of Neuroradiology, King' s College Hospital NHS Foundation Trust, London (United Kingdom)

    2011-04-15

    The most frequent lesion identified at the cerebellopontine angle cistern and internal auditory meatus (IAM) is the vestibular schwannoma. Radiological features, the role of imaging in screening and follow-up, therapeutic approaches and appearances following treatment will be discussed. Other cerebellopontine angle lesions will be illustrated and an algorithm presented to help in the imaging differential diagnosis. Whilst lesions other than vestibular schwannomas are rarely isolated to the IAM, the key clinical and radiological features that should raise the possibility of alternative neoplastic and inflammatory diseases will be highlighted.

  14. Current treatment strategy in the management of vestibular schwannoma

    Directory of Open Access Journals (Sweden)

    Misra Basant

    2009-01-01

    Full Text Available Background: The changing trends in the management of vestibular schwannoma (VS in our practice over the last two decades as well as the current status are presented here. Materials and Methods: The observations are based on the experience of 559 consecutive cases of VS operated by the first author between 1987 and 2008, 438 of which were operated by microsurgery and 139 by gamma knife radiosurgery (GKR (18 of which were previously operated by the authors. A detailed analysis of microsurgically managed patients in two different periods (100 consecutive patients each before 1993 and 2008 were compared to see the changing trend and document current results. Results and Discussion: In the initial experience (1990s, the emphasis in microsurgery was preserving life, total excision of tumor and preservation of function in that order. In the 21 st century, the emphasis in microsurgery has been all about functional preservation. In 100 consecutive cases of VS (excluding neurofibromatosis-2 that were treated microsurgically between 2005-08, there were four small tumors (< 2 cm, 14 medium-sized tumors (2-3 cm and 82 large tumors (≥3 cm. The total excision rate was 83%. The facial nerve anatomical preservation rate was 96% and function was Grade III House-Brackmann (HB or better in 87%. Both the total excision rate and facial function of Grade II HB or better were 100% in cases with tumor size less than three cm. Functional hearing preservation was achieved in ten cases. There was no operative mortality. Conclusion: Total excision of VS, though aimed at, is no more pursued at the cost of facial function. Moreover, microsurgery, radiosurgery and observation are all valid options in the management of VS and choosing the correct modality helps in achieving optimal outcome.

  15. Vestibular system paresis due to emergency endovascular catheterization

    Directory of Open Access Journals (Sweden)

    Simoceli, Lucinda

    2012-01-01

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

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

    Science.gov (United States)

    Schüz, Joachim; Steding-Jessen, Marianne; Hansen, Søren; Stangerup, Sven-Eric; Cayé-Thomasen, Per; Johansen, Christoffer

    2010-12-01

    Vestibular schwannoma (VS) (or acoustic neuroma) accounts for about 5%-6% of all intracranial tumors; little is known about the etiology. We investigated the association between various sociodemographic indicators and VS in a cohort of 3.26 million Danish residents, with 1087 cases identified in 35 308 974 person-years under risk, with data accrued from 1993 to 2006. Complete ascertainment of cases was ensured by using population-based and clinical cancer registries. Information on sociodemographic indicators was obtained on an annually updated individual level from Statistics Denmark. Log-linear Poisson regression models were used to estimate incidence rate ratios (IRRs). Linear regression models were used to examine the association between sociodemographic indicators and tumor size. We found that IRRs decreased gradually with decreasing level of education, with values of 0.62 (95% CI: 0.49-0.78) for men and 0.62 (95% CI: 0.50-0.77) for women with a basic education compared with a higher education. Similar results were found for disposable income. Marital status was associated with a higher incidence of VS in men but not women; nonmarried men with a basic education had an IRR of 0.34 (95% CI: 0.23-0.50) compared with married men with a higher education. Lower incidence rates were also observed among unemployed or early-retirement pensioners, whereas there were no differences in incidence rates across the broad groups of occupations and across the types of districts. Sociodemographic indicators were not associated with the tumor size. The magnitude of the differences in incidence rates across the groups of different socioeconomic indicators suggests a high potential for earlier diagnosis of VS by improving the awareness of early symptoms. PMID:21068153

  17. Gamma Knife radiosurgery following subtotal resection of vestibular schwannoma.

    Science.gov (United States)

    Brokinkel, Benjamin; Sauerland, Cristina; Holling, Markus; Ewelt, Christian; Horstmann, Gerhard; van Eck, Albertus T C J; Stummer, Walter

    2014-12-01

    During treatment of large vestibular schwannomas, incomplete resection (IR) followed by Gamma Knife surgery (GKS; Elekta AB, Stockholm, Sweden) possibly offers tumor growth control and good clinical outcome, and is being discussed as an alternative to complete tumor removal with its inherent risks, especially for facial nerve function. However, available data for this concept are limited due to the small number of published studies. To analyze the effects of combined therapy in a larger cohort, we reviewed the currently available data. Six studies comprising 159 patients with a tumor diameter of at least 2 cm were included (median volume 19.95 cm(3) in four studies, n=137). GKS was performed on average 6 months postoperatively with a mean marginal dose of 11.88 Gy (mean target volume 4.42 cm(3), mean diameter 18.45 mm). Preoperatively facial nerve function was serviceable (House and Brackmann Grades I+II) in 158 of 159 patients (99.4%) and in 125 of 151 patients (82.8%, 95% confidence interval [CI] 76-88%) postoperatively. Hearing was serviceable in 29 of 151 patients (19.2%) preoperatively and in 16 of 79 patients postoperatively (20.2%, 95%CI 12-31%). Within a mean follow-up time of 50 months (range 12-102 months), facial nerve function and hearing after IR remained serviceable in 142 of 151 (94.0%, 95%CI 89-97%) and 15 of 129 patients (11.6%, 95%CI 7-18%). Tumor growth control was achieved in 149 of 159 patients (93.8%). Six patients were subjected to repeated therapy. Minimal complications were reported for microsurgery and GKS. Combined therapy was shown to be beneficial regarding both tumor control and adverse side effects among all analyzed studies. PMID:25065850

  18. The caloric vestibular nystagmus during short lasting microgravity

    Science.gov (United States)

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

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

  19. Microsurgery for vestibular schwannoma after gamma knife radiosurgery

    International Nuclear Information System (INIS)

    We evaluated the clinical characteristics of microsurgery for vestibular schwannoma (VS) after failed gamma knife radiosurgery (GKS). Twelve patients, 5 men and 7 women aged 19 to 70 years (mean 54.5 years), who underwent microsurgery after failed GKS for VS were studied retrospectively. The median interval between GKS and microsurgery was 28.8 months (range, 6.6-120 months) and 4 patients had undergone previous microsurgery. The mean volume of tumor at GKS was 6.9 cm3 (range, 0.5-19.7 cm3) and the mean prescription dose to the tumor margin was 12.3 Gy. Microsurgery involved the lateral suboccipital approach in all patients. Tumour expansion involved solid enlargement in 7 patients, cystic enlargement in 3, and central necrosis in 2. Bleeding was slight in all patients except in one, probably because of the previous irradiation. Adhesion to the brain stem was severe in 7 patients. Identification of the facial nerve was easy in 5 operations and difficult in 7. Dissection of the tumor from the facial nerve was difficult in most interventions because of severe adhesions or colour change. Severe adhesions between the trigeminal nerve and the tumor was observed in 2 patients. The tumor was subtotally removed except around the internal auditory canal in most patients. Only one residual tumor increased in size and needed second GKS. The function of the facial nerve deteriorated in 3 patients, was unchanged in 7, and improved in 2. All patients had lost hearing on the affected side at the time of microsurgery. Microsurgery for VS after failed GKS presents some technical difficulties. Dissection of the tumor from the facial nerve or brain stem is likely to be difficult. We recommend subtotal resection without dissection of the facial nerve and tumor, because growth of the residual tumor was rare in our series. (author)

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

    Directory of Open Access Journals (Sweden)

    Alejandro Peña M

    2011-08-01

    Full Text Available Introducción: En el examen vestibular de un paciente vertiginoso juegan un rol muy importante las pruebas calóricas, pero la realización de éstas, unida a las nuevas pruebas que ha traído el avance tecnológico y computacional de la medicina, ha significado que el examen vestibular se ha convertido 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 available bibliography, particularly medical studies based on evidence, the following test are described, interpreted and analyzed : spontaneous nystagmus, gaze nystagmus, smooth pursuit, saccades, Halmagyi test, head shake test, , dynamic visual acuity test, fixation suppression test, Dix-Hallpike maneuver, aural pressure/sound test, cerebellar limbs, somato-sensation test, Romberg test, and gait test. Since most of these tests are performed in the classic vestibular examination, only non-routine ones are analyzed and discussed. Results: Most analyzed test show low sensitivity, under 50%%, but good specificity. With some basic training they are easy to carry out, and they require a short length of time, but over 10 minutes. Discussion: Taking into consideration the long time the specialist needs for a vestibular examination, a basic vestibular study is highly necessary to guide the dizzy patient's clinical investigation. The tests suggested in this examination have a low sensitivity individually considered. But carrying out all of these together, added to a solid anamnesis with a pre-established structured questionnaire, gives the study strength and reliability. Conclusion: The abbreviated vestibular examination is a good study. Although the various tests have a low sensitivity, the result of the addition of all of them, give the exam high reliability. To carry it out successfully, is essential to have a proper management of the test and a solid knowledge of neurotology, so that the examiner can make a good interpretation. No studies of Medicine based on evidence level 1 or 2 to give reliability to these test are available. This examination does not replace the classical examination, including bi-thermal caloric testing. It can be considered as a basic study aimed at guiding specialists to take suitable measures.

  1. NEURON and Python

    OpenAIRE

    Michael Hines; Andrew P. Davison; Eilif Muller

    2009-01-01

    The NEURON simulation program now allows Python to be used, alone or in combination with NEURON's traditional Hoc interpreter. Adding Python to NEURON has the immediate benefit of making available a very extensive suite of analysis tools written for engineering and science. It also catalyzes NEURON software development by offering users a modern programming tool that is recognized for its flexibility and power to create and maintain complex programs. At the same time, nothing is lost because ...

  2. Mirror Neurons: Recent Progresses

    OpenAIRE

    Leonardo Fogassi

    2009-01-01

    Mirror neurons are a distinct set of neurons, originally discovered in the premotor cortex (area F5) and the inferior parietal lobule of the monkey that discharge both when the monkey executes a specific action and when it observes another individual doing a similar action. In the first part of my lecture, I will review the basic functional properties of mirror neurons. I will describe first their motor properties. I will show that, as most neurons in the premotor cortex and inferior pariet...

  3. Motor Neurons that Multitask

    OpenAIRE

    Goulding, Martyn

    2012-01-01

    Animals use a form of sensory feedback termed proprioception to monitor their body position and modify the motor programs that control movement. In this issue of Neuron, Wen et al. (2012) provide evidence that a subset of motor neurons function as proprioceptors in C. elegans, where B-type motor neurons sense body curvature to control the bending movements that drive forward locomotion.

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

    Science.gov (United States)

    Mulavara, A. P.; Kofman, I. S.; De Dios, Y. E; Galvan, R.; Goel, R.; Miller, C.; Peters, B.; Cohen, H. S.; Jeevarajan, J.; Reschke, M.; Wood, S.; Bergquist, F.; Seidler, R. D.; Bloomberg, J. J.

    2014-01-01

    Crewmember adapted to the microgravity state may need to egress the vehicle within a few minutes for safety and operational reasons after gravitational transitions. The transition from one sensorimotor state to another consists of two main mechanisms: strategic and plastic-adaptive and have been demonstrated in astronauts returning after long duration space flight. Strategic modifications represent "early adaptation" - immediate and transitory changes in control that are employed to deal with short-term changes in the environment. If these modifications are prolonged then plastic-adaptive changes are evoked that modify central nervous system function, automating new behavioral responses. More importantly, this longer term adaptive recovery mechanism was significantly associated with their strategic ability to recover on the first day after return to Earth G. We are developing a method based on stochastic resonance to enhance information transfer by improving the brain's ability to detect vestibular signals (Vestibular Stochastic Resonance, VSR) especially when combined with balance training exercises such as sensorimotor adaptability (SA) training for rapid improvement in functional skill, for standing and mobility. This countermeasure to improve detection of vestibular signals is a stimulus delivery system that is wearable/portable providing low imperceptible levels of white noise based binaural bipolar electrical stimulation of the vestibular system (stochastic vestibular stimulation). To determine efficacy of vestibular stimulation on physiological and perceptual responses during otolith-canal conflicts and dynamic perturbations we have conducted a series of studies: We have shown that imperceptible binaural bipolar electrical stimulation of the vestibular system across the mastoids enhances balance performance in the mediolateral (ML) plane while standing on an unstable surface. We have followed up on the previous study showing VSR stimulation improved balance performance in both ML and anteroposterior planes while stimulating in the ML axis only. We have shown the efficacy of VSR stimulations on enhancing physiological and perceptual responses of whole-body orientation during low frequency perturbations (0.1 Hz) on the ocular motor system using a variable radius centrifuge on both physiological (using eye movements) and perceptual responses (using a joystick) to track imposed oscillations. The variable radius centrifuge provides a selective tilting sensation that is detectable only by the otolith organs providing conflicting information from the canal organs of the vestibular system (intra-vestibular conflict). These results indicate that VSR can improve performance in sensory conflict scenarios like that experienced during space flight. We have showed the efficacy of VSR stimulation to improve balance and locomotor control on subjects exposed to continuous, sinusoidal lateral motion of the support surface while walking on a treadmill while viewing perceptually matched linear optic flow. We have shown the safety of short term continuous use of up to 4 hours of VSR stimulation and its efficacy in improving balance and locomotor function in Parkinson's Disease patients. This technique for improving vestibular signal detection may thus provide additional information to improve strategic abilities. We hypothesize that VSR stimulation will act synergistically with SA training to improve adaptability by increased utilization of vestibular information and therefore serve to optimize and personalize the SA countermeasure prescription. This forms the basis of its usefulness both as a training modality and further help in significantly reducing the number of days required to recover functional performance to preflight levels after long duration space flight.

  5. Implante coclear e síndrome do aqueduto vestibular alargado em crianças Cochlear implant and large vestibular aqueduct syndrome in children

    Directory of Open Access Journals (Sweden)

    Trissia Maria Farah Vassoler

    2008-04-01

    Full Text Available Crianças com SAVA podem ter deficiências auditivas moderadas a severas durante fases precoces da infância, porém sua audição residual permite que elas desenvolvam linguagem oral com aparelhos auditivos convencionais e possam estar completamente integradas a condições escolares regulares. Contudo, estas crianças apresentam uma deterioração de sua habilidade auditiva com o decorrer do tempo e o implante coclear está sendo utilizado como uma opção para manter a habilidade auditiva. OBJETIVO: Avaliação da habilidade auditiva de 3 crianças com SAVA submetidas a implante coclear. MATERIAIS: Estudo retrospectivo baseado em revisão de prontuários. RESULTADOS: Em reconhecimento de palavras em campo aberto paciente 1, 80%, paciente 2, 87,5%, paciente 3, 4%. CONCLUSÃO: Os pacientes com aqueduto vestibular alargado são considerados bons candidatos para implante coclear pelos principais centros de implante coclear do mundo, por desenvolverem, em sua maioria, bons resultados de percepção de fala, o que leva estes pacientes a uma boa inserção social.Children with LVAS can develop a severe sensorineural hearing loss early in childhood, but they can be rehabilitated with hearing aids to continue their regular studies and to have a normal life. The problem is that they can deteriorate their hearing capacity, and at this point a cochlear implant can be used to preserve their hearing skills and vocalization. AIM: to evaluate the hearing skills of 3 children with LVAS referred to cochlear implants. MATERIAL: retrospective study based on medical charts' review. RESULTS: Speech recognition in open field: patient 1, 80%; patient 2, 87.5%; patient 3, 4 %. CONCLUSION: Children with LVAS are considered good candidates for Cochlear implant surgery by the most important centers of the world because most of them can develop good speech recognition, providing them a good social life.

  6. Need for facial reanimation after operations for vestibular schwannoma: patients perspective

    DEFF Research Database (Denmark)

    Tos, Tina; Caye-Thomasen, Per; Stangerup, Sven-Eric; Thomsen, Jens; Tos, Mirko

    2003-01-01

    A total of 779 patients operated on for vestibular schwannoma mostly by the translabyrinthine approach in Denmark during the period 1976-2000 answered a questionnaire about various postoperative consequences. In this paper we describe the patients' facial function evaluated by professionals one y...

  7. Vestibular responses to loud dance music: a physiological basis of the "rock and roll threshold"?

    Science.gov (United States)

    Todd, N P; Cody, F W

    2000-01-01

    In this paper new evidence is provided to indicate that vestibular responses may be obtained from loud dance music for intensities above 90 dB(A) SPL (Impulse-weighted). In a sample of ten subjects acoustically evoked EMG were obtained from the sternocleidomastoid muscle in response to a sample of techno music typical of that which may be experienced in a dance club. Previous research has shown that this response is vestibularly mediated since it can be obtained in subjects with loss of cochlear function, but is absent in subjects with loss of vestibular function (Colebatch et al. [J. Neurol. Neurosurg. Psychiatr. 57, 190-197 (1994)]. Given that pleasurable sensations of self-motion are widely sought after by more normal means of vestibular stimulation, it is suggested that acoustically evoked sensations of self-motion may account for the compulsion to exposure to loud music. Given further the similarity between the thresholds found, and the intensities and frequency distributions that are typical in rock concerts and dance clubs, it is also suggested that this response may be a physiological basis for the minimum loudness necessary for rock and dance music to work-the "rock and roll threshold". PMID:10641657

  8. [Enlarged vestibular aqueduct syndrome: report of 3 cases and literature review].

    Science.gov (United States)

    Pinto, José A; Mello, Carlos Fernando; Marqui, Ana Carla S; Perfeito, Delmer J; Ferreira, Roberto D P; Silva, Rubens H

    2005-01-01

    The Enlarged Vestibular Aqueduct Syndrome is characterized by a widening of the vestibular aqueduct, associated with sensorineural hearing loss, or sometimes with mixed hearing loss, which may be congenital or acquired during childhood. The sensorineural hearing loss may be classified into mild, moderate and severe, associated with sudden periods of improvement or aggravation. The enlargement of the vestibular aqueduct is the most common inner ear anomaly. This syndrome is admitted as a result of a genetic abnormality of the vestibular aqueduct development, previous to the fifth week of gestation. The incidence of this syndrome ranges from 1% to 1.3%, with the possibility of getting up to 7%, depending on the examined population. The aim of this study was to analyze three cases of LVAS seen at the Otorhinolaryngology and Radiology Department of Sao Camilo Hospital - Sao Paulo. Two of these three cases were of brothers, from the same mother but from different fathers. Two were male and one was female and the ages ranged from 9 to 30 years old. The diagnosed method of election was CT, Computerized Tomography of the temporal bones. The procedure for the cases was that of observation, with exception for those of cranial traumatisms, barotraumas and, when necessary, the use of auditive prosthesis. PMID:16446948

  9. Influência da reabilitação vestibular na qualidade de vida de indivíduos labirintopatas

    Directory of Open Access Journals (Sweden)

    Shirley Nogueira Soares

    2014-06-01

    Full Text Available Objetivo verificar a influência da reabilitação vestibular sobre a qualidade de vida dos indivíduos por meio do questionário Dizziness Handicap Inventory aplicado pré e pós-terapia. Métodos: foram analisados 28 prontuários de indivíduos de ambos os sexos atendidos em uma Clínica Escola do município de Belo Horizonte. Os pacientes responderam ao questionário pré e pós terapia de reabilitação vestibular personalizada (RVP. A análise estatística dos dados foi feita por meio do teste T-Student pareado. Resultados a amostra do estudo foi composta por 28 pacientes, sendo 23 (82 % do sexo feminino. A idade média dos pacientes foi de 54,7 (± 20,6 anos e o número médio de sessões de terapia foi 5,6 (± 6,4. Antes do tratamento os pacientes apresentaram os seguintes escores: 18,10 (±9,83 nos aspectos físicos, 13,53 (±8,57 nos funcionais e 15,14 (±7,48 nos emocionais. Após uma média de 5,6 (± 6,4 sessões, houve diminuição significante (p<0,05 dos escores nos aspectos físicos 4,32 (±5,32, funcionais 4,32 (±6,91 e emocionais 3,78 (±5,16. Conclusão pode-se concluir que houve diferença estatisticamente significante entre os escores do Dizziness Handicap Inventory pré e pós-reabilitação vestibular personalizada, mostrando que a reabilitação vestibular é um importante instrumento na melhoria da qualidade de vida de pacientes labirintopatas.

  10. Can Postural Instability Respond to Galvanic Vestibular Stimulation in Patients with Parkinson’s Disease?

    Directory of Open Access Journals (Sweden)

    Hiroshi Kataoka

    2016-01-01

    Full Text Available Objective Galvanic vestibular stimulation (GVS activates the vestibular afferents, and these changes in vestibular input exert a strong influence on the subject’s posture or standing balance. In patients with Parkinson’s disease (PD, vestibular dysfunction might contribute to postural instability and gait disorders. Methods Current intensity was increased to 0.7 mA, and the current was applied to the patients for 20 minutes. To perform a sham stimulation, the current intensity was increased as described and then decreased to 0 mA over the course of 10 seconds. The patient’s status was recorded continuously for 20 minutes with the patient in the supine position. Results Three out of 5 patients diagnosed with PD with postural instability and/or abnormal axial posture showed a reduction in postural instability after GVS. The score for item 12 of the revised Unified Parkinson’s Disease Rating Scale part 3 was decreased in these patients. Conclusions The mechanism of postural instability is complex and not completely understood. In 2 out of the 5 patients, postural instability was not changed in response to GVS. Nonetheless, the GVS-induced change in postural instability for 3 patients in our study suggests that GVS might be a therapeutic option for postural instability.

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

    Directory of Open Access Journals (Sweden)

    S Maruthy

    2012-06-01

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

  12. Visual and Vestibular Induced Eye Movements in Verbal Children and Adults with Autism.

    Science.gov (United States)

    Furman, Joseph M; Osorio, Maria J; Minshew, Nancy J

    2015-12-01

    This study assessed the functionality of vestibular, pursuit, and saccade circuitry in autism across a wide age range. Subjects were 79 individuals with autism (AUT) and 62 controls (CON) aged 5 to 52 years with IQ scores?>?70. For vestibular testing, earth-vertical axis rotation was performed in darkness and in a lighted visual surround with a fixation target. Ocular motor testing included assessment of horizontal saccades and horizontal smooth pursuit. No between-group differences were found in vestibular reflexes or in mean saccade velocity or accuracy. Saccade latency was increased in the AUT group with significant age-related effects in the 8-18 year old subgroups. There was a trend toward decreased pursuit gain without age effects. Normal vestibular-induced eye movements and normal saccade accuracy and velocity provide the most substantial evidence to date of the functional integrity of brainstem and cerebellar pathways in autism, suggesting that the histopathological abnormalities described in these structures may not be associated with intrinsic dysfunction but rather reflect developmental alterations related to forebrain cortical systems formation. Increased saccade latency with age effects adds to the extensive existing evidence of altered function and maturation of cortical systems in autism. Autism Res 2015, 8: 658-667. © 2015 International Society for Autism Research, Wiley Periodicals, Inc. PMID:25846907

  13. Effects of Vestibular Stimulation on Motor Development and Stereotyped Behavior of Developmentally Delayed Children.

    Science.gov (United States)

    MacLean, William E., Jr.; Baumeister, Alfred A.

    1982-01-01

    Four developmentally delayed babies were given semicircular canal stimulation in an effort to facilitate their motor and reflex development. All of the children showed motor and/or reflex changes that were attributable to the vestibular stimulation. In addition, some evidence was obtained linking changes in stereotypic responding to the vestibular…

  14. Minimally Invasive Endoscopic and Endoscopy-Assisted Microsurgery of Vestibular Schwannoma

    Czech Academy of Sciences Publication Activity Database

    Betka, J.; Chovanec, M.; Zvěřina, E.; Profant, Oliver; Lukeš, P.; Skřivan, J.; Kluh, J.; Fík, Z.

    Rijeka : InTech, 2011, s. 191-216. ISBN 978-953-307-717-8 R&D Projects: GA MZd NT12459 Institutional research plan: CEZ:AV0Z50390512; CEZ:AV0Z50390703 Keywords : vestibular schwannoma * microscopy and endoscopy Subject RIV: FJ - Surgery incl. Transplants; FH - Neurology (UEM-P)

  15. Potencial evocado auditivo para diagnóstico de surdez em gato com síndrome vestibular periférica

    Directory of Open Access Journals (Sweden)

    M.I.P. Palumbo

    2013-12-01

    Full Text Available Potencial evocado auditivo é um método eletrodiagnóstico que permite avaliação funcional das vias auditivas desde a orelha média até o tronco encefálico. O uso desse teste em medicina veterinária é pouco difundido no Brasil. O presente artigo relata o uso do potencial evocado auditivo para detecção de deficiência auditiva unilateral em um gato com síndrome vestibular periférica secundária a otite média.

  16. Manual control of yaw motion with combined visual and vestibular cues

    Science.gov (United States)

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

    1977-01-01

    Measurements are made of manual control performance in the closed-loop task of nulling perceived self-rotation velocity about an earth-vertical axis. Self-velocity estimation was modelled as a function of the simultaneous presentation of vestibular and peripheral visual field motion cues. Based on measured low-frequency operator behavior in three visual field environments, a parallel channel linear model is proposed which has separate visual and vestibular pathways summing in a complementary manner. A correction to the frequency responses is provided by a separate measurement of manual control performance in an analogous visual pursuit nulling task. The resulting dual-input describing function for motion perception dependence on combined cue presentation supports the complementary model, in which vestibular cues dominate sensation at frequencies above 0.05 Hz. The describing function model is extended by the proposal of a non-linear cue conflict model, in which cue weighting depends on the level of agreement between visual and vestibular cues.

  17. Late malignant transformation of vestibular schwannoma in the absence of irradiation

    DEFF Research Database (Denmark)

    Bashir, Asma; Poulsgaard, Lars; Broholm, Helle; Fugleholm, KÃ¥re

    2016-01-01

    Late malignant transformation of vestibular schwannoma (VS) following irradiation has previously been reported 29 times in the literature. Here, the authors report the first late malignant transformation of VS unrelated to neurofibromatosis or radiation exposure. After undergoing a near-total exc...

  18. Long-term quality of life and tumour control following gamma knife radiosurgery for vestibular schwannoma

    DEFF Research Database (Denmark)

    Wangerid, Theresa; Bartek, Jiri; Svensson, Mikael; Förander, Petter

    2014-01-01

    Gamma knife radiosurgery (GKRS) has for the last decades been an established treatment option for patients with small- or medium-sized vestibular schwannomas (VS), although little data is reported on long-term outcome regarding quality of life (QOL) and tumour control in this patient category. The...

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

    OpenAIRE

    Swathi; Sathish Kumar

    2013-01-01

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

  20. Ontogeny of vestibular compound action potentials in the domestic chicken

    Science.gov (United States)

    Jones, S. M.; Jones, T. A.

    2000-01-01

    Compound action potentials of the vestibular nerve were measured from the surface of the scalp in 148 chickens (Gallus domesticus). Ages ranged from incubation day 18 (E18) to 22 days posthatch (P22). Responses were elicited using linear acceleration cranial pulses. Response thresholds decreased at an average rate of -0.45 dB/day. The decrease was best fit by an exponential model with half-maturity time constant of 5.1 days and asymptote of approximately -25.9 dB re:1.0 g/ms. Mean threshold approached within 3 dB of the asymptote by ages P6-P9. Similarly, response latencies decreased exponentially to within 3% of mature values at ages beyond P9. The half-maturity time constant for peripheral response peak latencies P1, N1, and P2 was comparable to thresholds and ranged from approximately 4.6 to 6.2 days, whereas central peaks (N2, P3, and N3) ranged from 2.9 to 3.4 days. Latency-intensity slopes for P1, N1, and P2 tended to decrease with age, reaching mature values within approximately 100 hours of hatching. Amplitudes increased as a function of age with average growth rates for response peaks ranging from 0.04 to 0.09 microV/day. There was no obvious asymptote to the growth of amplitudes over the ages studied. Amplitude-intensity slopes also increased modestly with age. The results show that gravity receptors are responsive to transient cranial stimuli as early as E19 in the chicken embryo. The functional response of gravity receptors continues to develop for many days after all major morphological structures are in place. Distinct maturational processes can be identified in central and peripheral neural relays. Functional improvements during maturation may result from refinements in the receptor epithelia, improvements in central and peripheral synaptic transmission, increased neural myelination, as well as changes in the mechanical coupling between the cranium and receptor organ.

  1. Surgical management of vestibular schwannomas after failed radiation treatment.

    Science.gov (United States)

    Nonaka, Yoichi; Fukushima, Takanori; Watanabe, Kentaro; Friedman, Allan H; Cunningham, Calhoun D; Zomorodi, Ali R

    2016-04-01

    Increasing numbers of patients with vestibular schwannoma (VS) have been treated with focused-beam stereotactic radiation treatment (SRT) including Gamma knife, CyberKnife, X-knife, Novalis, or proton beam therapy. The purpose of this study was to document the incidence of tumor regrowth or symptoms that worsened or first developed following SRT and to discuss surgical strategies for patients who have failed SRT for VS. A consecutive series of 39 patients with SRT failed VS were surgically treated. Clinical symptoms, tumor regrowth at follow-up, intraoperative findings, and surgical outcome were evaluated. There were 15 males and 24 females with a mean age of 51.8 years. Thirty-six patients (92.3 %) demonstrated steady tumor growth after SRT. Two (5.1 %) patients with slight increase of the mass underwent surgical resection because of development of unbearable facial pain. Symptoms that worsened or newly developed following SRT in this series were deafness (41 %), dizziness (35.9 %), facial numbness (25.6 %), tinnitus (20.5 %), facial nerve palsy (7.7 %), and facial pain (7.7 %). Intraoperative findings demonstrated fibrous changes of the tumor mass, cyst formation, and brownish-yellow or purple discoloration of the tumor capsule. Severe adhesions between the tumor capsule and cranial nerves, vessels, and the brainstem were observed in 69.2 %. Additionally, the facial nerve was more fragile and irritable in all cases. Gross total resection (GTR) was achieved in 33.3 % of patients, near-total resection (NTR) in 35.9 %, and subtotal resection (STR) in 30.8 % of patients. New facial nerve palsy was seen in seven patients (19.4 %) postoperatively. Our findings suggest that patients with VS who fail SRT with either tumor progression or worsening of clinical symptoms will have an increased rate of adhesions to the neurovascular structures and may have radiation-influenced neuromalacia. Salvage surgery of radiation-failed tumors is more difficult and will have a higher risk of postoperative complications. Radical total resection may not be feasible, and conservative modality of subtotal resection needs to be considered to avoid new neurologic deficits. PMID:26782633

  2. Optimal Stimulus Amplitude for Vestibular Stochastic Stimulation to Improve Sensorimotor Function

    Science.gov (United States)

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

    2014-01-01

    Sensorimotor changes such as postural and gait instabilities can affect the functional performance of astronauts when they transition across different gravity environments. We are developing a method, based on stochastic resonance (SR), to enhance information transfer by applying non-zero levels of external noise on the vestibular system (vestibular stochastic resonance, VSR). Our previous work has shown the advantageous effects of VSR in a balance task of standing on an unstable surface. This technique to improve detection of vestibular signals uses a stimulus delivery system that is wearable or portable and provides imperceptibly low levels of white noise-based binaural bipolar electrical stimulation of the vestibular system. The goal of this project is to determine optimal levels of stimulation for SR applications by using a defined vestibular threshold of motion detection. A series of experiments were carried out to determine a robust paradigm to identify a vestibular threshold that can then be used to recommend optimal stimulation levels for SR training applications customized to each crewmember. Customizing stimulus intensity can maximize treatment effects. The amplitude of stimulation to be used in the VSR application has varied across studies in the literature such as 60% of nociceptive stimulus thresholds. We compared subjects' perceptual threshold with that obtained from two measures of body sway. Each test session was 463s long and consisted of several 15s sinusoidal stimuli, at different current amplitudes (0-2 mA), interspersed with 20-20.5s periods of no stimulation. Subjects sat on a chair with their eyes closed and had to report their perception of motion through a joystick. A force plate underneath the chair recorded medio-lateral shear forces and roll moments. First we determined the percent time during stimulation periods for which perception of motion (activity above a pre-defined threshold) was reported using the joystick, and body sway (two standard deviation of the noise level in the baseline measurement) was detected by the sensors. The percentage time at each stimulation level for motion detection was normalized with respect to the largest value and a logistic regression curve fit was applied to these data. The threshold was defined at the 50% probability of motion detection. Comparison of threshold of motion detection obtained from joystick data versus body sway suggests that perceptual thresholds were significantly lower, and were not impacted by system noise. Further, in order to determine optimal stimulation amplitude to improve balance, two sets of experiments were carried out. In the first set of experiments, all subjects received the same level of stimuli and the intensity of optimal performance was projected back on subjects' vestibular threshold curve. In the second set of experiments, on different subjects, stimulation was administered from 20-400% of subjects' vestibular threshold obtained from joystick data. Preliminary results of our study show that, in general, using stimulation amplitudes at 40-60% of perceptual motion threshold improved balance performance significantly compared to control (no stimulation). The amplitude of vestibular stimulation that improved balance function was predominantly in the range of +/- 100 to +/- 400 micro A. We hypothesize that VSR stimulation will act synergistically with sensorimotor adaptability (SA) training to improve adaptability by increasing utilization of vestibular information and therefore will help us to optimize and personalize a SA countermeasure prescription. This combination will help to significantly reduce the number of days required to recover functional performance to preflight levels after long-duration spaceflight.

  3. Neurochemical organization of the vestibular brainstem in the common chimpanzee (Pan troglodytes).

    Science.gov (United States)

    Baizer, Joan S; Paolone, Nicholas A; Sherwood, Chet C; Hof, Patrick R

    2013-11-01

    Chimpanzees are one of the closest living relatives of humans. However, the cognitive and motor abilities of chimpanzees and humans are quite different. The fact that humans are habitually bipedal and chimpanzees are not implies different uses of vestibular information in the control of posture and balance. Furthermore, bipedal locomotion permits the development of fine motor skills of the hand and tool use in humans, suggesting differences between species in the structures and circuitry for manual control. Much motor behavior is mediated via cerebro-cerebellar circuits that depend on brainstem relays. In this study, we investigated the organization of the vestibular brainstem in chimpanzees to gain insight into whether these structures differ in their anatomy from humans. We identified the four nuclei of vestibular nuclear complex in the chimpanzee and also looked at several other precerebellar structures. The size and arrangement of some of these nuclei differed between chimpanzees and humans, and also displayed considerable inter-individual variation. We identified regions within the cytoarchitectonically defined medial vestibular nucleus visualized by immunoreactivity to the calcium-binding proteins calretinin and calbindin as previously shown in other species including human. We have found that the nucleus paramedianus dorsalis, which is identified in the human but not in macaque monkeys, is present in the chimpanzee brainstem. However, the arcuate nucleus, which is present in humans, was not found in chimpanzees. The present study reveals major differences in the organization of the vestibular brainstem among Old World anthropoid primate species. Furthermore, in chimpanzees, as well as humans, there is individual variability in the organization of brainstem nuclei. PMID:23179862

  4. Long-term vestibulocochlear functional outcome following retro-sigmoid approach to resection of vestibular schwannoma.

    Science.gov (United States)

    Abboud, Tammam; Regelsberger, Jan; Matschke, Jakob; Jowett, Nathan; Westphal, Manfred; Dalchow, Carsten

    2016-03-01

    The objective of this study was to evaluate long-term vestibulocochlear functional outcomes of patients operated for unilateral vestibular schwannoma via the retro-sigmoid approach. Patients who underwent vestibular schwannoma resection via retro-sigmoid approach between 2004 and 2008 at our institution, without prior surgical or radio-surgical therapy were considered to be eligible for this study. Preoperative auditory and vestibular symptoms were assessed retrospectively. Postoperative symptoms were prospectively assessed using a standardised questionnaire, pure tone audiometry, video-oculography, and rotary chair testing. Out of a total of 203 patients, 120 were eligible for this study, of whom 64 responded to follow-up requests and could be enrolled. Serviceable hearing was reported in 42 patients (66 %) preoperatively and was maintained in 18 (43 %) postoperatively. While no significant change in rate of tinnitus and balance impairment between pre- and postoperative periods was detected, vertigo decreased significantly (40 to 28 %, p < 0.001). Postoperative video-oculography demonstrated vestibular paresis in 80 %. Rotary chair testing demonstrated normal or central compensation in 84 %. Absence of central compensation was associated with postoperative balance disturbance (p = 0.035). Increasing tumour size and patient age, also decreasing quality of preoperative hearing were independent factors predictive of a postoperative non-serviceable hearing (p = 0.020, p = 0.039 and p = 0.002, respectively). Resection of vestibular schwannoma via the retro-sigmoid approach is associated with improvement in postoperative vertiginous symptoms. Absence of central compensation leads to increased postoperative balance disturbances. Preservation of serviceable postoperative hearing is associated with good preoperative hearing status, younger age, and smaller tumours. PMID:25700833

  5. Role of radiosurgery and stereotactic radiotherapy in the management of vestibular schwannomas

    International Nuclear Information System (INIS)

    Purpose of the study. - In order to investigate the role of radiosurgery and stereotactic radiotherapy in the management of vestibular schwannomas, we have reviewed our own prospective cohort and the main series of the modern literature. Patients and methods. - Between July 14, 1992 and June 1, 2011, 2991 vestibular schwannomas were operated on the Stereotactic and Functional Neurosurgery Department of Timone University Hospital. All the patients have been evaluated prospectively, with a follow up longer than 3 years for 2336 patients, excluding patients suffering from type 2 neurofibromatosis (148 patients). In 7% of the patients, the vestibular schwannoma had previously been resected. According to Koos classification, in 17.6% of the patients, vestibular schwannomas were stage I, 51.8% stage II, 27% stage III and 3.6% stage IV. The mean tumour volume was 2.63 cm3. According to Garner Robertson classification, the hearing was still functional at the time of radiosurgery in 46% and subnormal in 20.9% of the patients. Results. - Long term tumour control was achieved in 97.5% of the patients. A transient facial palsy was observed in 0.5% of the cases. The rate of trigeminal injury was 0.5%. Useful hearing was preserved at 3 years in 78%. This rate reached 95% in patients with no past history of sudden hearing loss. Other predictors of functional hearing preservation are the young age, the small size of the lesion and a dose to the modiulus of the cochlea lower than 4 Gy. We observed no radio-induced tumour. Only large, Koos IV vestibular schwannomas are contraindicated for up-front radiosurgery. In these patients, we propose a combined approach with a deliberately partial microsurgical removal, followed by a radiosurgery of the residue. Conclusion. - This cohort is unique by the size of the population and the length of the follow up and results demonstrate the efficacy of radiosurgery and its safety, especially its high rate of hearing preservation. (authors)

  6. Posturografia dinâmica computadorizada na avaliação do equilíbrio corporal de indivíduos com disfunção vestibular / Computerized dynamic posturography in the assessment of body balance in individuals with vestibular dysfunction

    Scientific Electronic Library Online (English)

    Danielle Tyemi Massukawa, Oda; Cristina Freitas, Ganança.

    2015-06-01

    Full Text Available Objetivo Avaliar o equilíbrio corporal de pacientes portadores de disfunção vestibular, por meio da posturografia dinâmica computadorizada. Métodos Estudo com 116 indivíduos com disfunção vestibular periférica, com idades entre 22 anos e 6 meses e 94 anos e 1 mês. Foram submetidos à avaliação otone [...] urológica completa, avaliação otorrinolaringológica, além da posturografia dinâmica computadorizada com os testes de organização sensorial, controle motor e de adaptação. Resultados O teste de organização sensorial foi o mais sensível para detectar alterações do equilíbrio e a condição 4, em que os pacientes permanecem na posição ortostática, com os pés afastados e sobre os sensores da superfície de referência, com os olhos abertos; condição 5, na qual os pacientes continuam na posição com os olhos fechados e a condição 6, em que os pacientes mantém os olhos abertos e o campo visual sofre deslocamentos anteroposteriores. Nas três condições, a superfície de referência oscila com movimentos similares à gangorra e foram as que os participantes apresentaram maiores dificuldades. Houve maior ocorrência de quedas se compararmos ao risco de quedas, avaliado quando o paciente tem pontuação entre 60 e 69 no índice de equilíbrio, principalmente a partir da condição 4 do teste de organização sensorial e entre os idosos. As mulheres tiveram maior número de quedas durante os testes. Conclusão A posturografia dinâmica computadorizada detectou as alterações relacionadas ao equilíbrio corporal, auxiliando no diagnóstico das disfunções e complementando a avaliação vestibular. Abstract in english Purpose To evaluate the body balance of patients with vestibular dysfunction with computerized dynamic posturography. Methods Study of 116 individuals with peripheral vestibular dysfunction, aged 22 years and 6 months old to 94 years and 1 month old were subjected to a complete otoneurological asse [...] ssment; computerized dynamic posturography with a sensory organization test, motor control test, and adaptation test; and an otolaryngological evaluation. Results The sensory organization test detected balance changes with the most sensitivity. Condition 4, during which the patients stood with their feet apart with them placed on the sensors of the reference surface and with their eyes open; condition 5, during which the patients remained in position with their eyes closed; condition 6, during which the patients kept their eyes open and their visual field underwent anterior-posterior displacement; and all three conditions when the reference surface moved in a see-saw manner were the conditions during which the participants had the greatest difficulties. The results showed patients with composite scores between 60 and 69, which indicated a higher occurrence of falls compared to the risk of falls, during condition 4 of the sensory organization test and among the elderly. Women had a higher number of falls during testing. Conclusion Computerized dynamic posturography, which concisely detected body balance changes, can be used in the diagnosis of vestibular disorders to complement vestibular assessments.

  7. Caracterização clínica de idosos com disfunção vestibular crônica Clinical evaluation of elderly people with chronic vestibular disorder

    OpenAIRE

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

    2006-01-01

    A tontura de origem vestibular é comum entre idosos. OBJETIVO: Caracterizar idosos com disfunção vestibular crônica em relação aos dados sociodemográficos, clínico-funcionais e otoneurológicos. MATERIAL E MÉTODO: Estudo de casos que incluiu 120 idosos com disfunção vestibular crônica. Foram realizadas análises descritivas simples. RESULTADOS: A 5,77±amostra apresentou maioria feminina (68,3%), com média etária de 73,40 1,84±anos. O número médio de doenças associadas ao quadro vestibular foi d...

  8. Noise and Neuronal Heterogeneity

    CERN Document Server

    Barber, Michael J

    2010-01-01

    We consider signal transaction in a simple neuronal model featuring intrinsic noise. The presence of noise limits the precision of neural responses and impacts the quality of neural signal transduction. We assess the signal transduction quality in relation to the level of noise, and show it to be maximized by a non-zero level of noise, analogous to the stochastic resonance effect. The quality enhancement occurs for a finite range of stimuli to a single neuron; we show how to construct networks of neurons that extend the range. The range increases more rapidly with network size when we make use of heterogeneous populations of neurons with a variety of thresholds, rather than homogeneous populations of neurons all with the same threshold. The limited precision of neural responses thus can have a direct effect on the optimal network structure, with diverse functional properties of the constituent neurons supporting an economical information processing strategy that reduces the metabolic costs of handling a broad...

  9. Effectiveness of conventional versus virtual reality based vestibular rehabilitation in the treatment of dizziness, gait and balance impairment in adults with unilateral peripheral vestibular loss: a randomised controlled trial

    OpenAIRE

    Dara Meldrum; Susan Herdman; Roisin Moloney; Deirdre Murray; Douglas Duffy; Kareena Malone; Helen French; Stephen Hone; Ronan Conroy; Rory McConn-Walsh

    2012-01-01

    Abstract Background Unilateral peripheral vestibular loss results in gait and balance impairment, dizziness and oscillopsia. Vestibular rehabilitation benefits patients but optimal treatment remains unkown. Virtual reality is an emerging tool in rehabilitation and provides opportunities to improve both outcomes and patient satisfaction with treatment. The Nintendo Wii Fit Plus® (NWFP) is a low cost virtual reality system that challenges balance and provides visual and auditory feedback. It ma...

  10. Dynamic Neuronal Excitability

    Directory of Open Access Journals (Sweden)

    Christoph Kirst

    2012-08-01

    Full Text Available Neurons generally show two types of excitability [1,2]: Type I neurons support arbitrary long inter-spike-intervals, while type II neurons start firing with a non-zero frequency upon current injection. Here we show that a transition from type I to type II can be dynamically controlled in a large number of conductance-based neuron models (including Wang-Buszaki, Morris-Lecar, Connor- Stevens, Erisir et al., e.g. by an increase in leak conductance. We mathematically prove that the bifurcation structure of this transition is organized by a degenerate Bogdanov-Takens-cusp bifurcation point of co-dimension 3 [3] which implies a switch from type I to type II for the spiking dynamics, a transition from integration to resonance near spike threshold, as well as a region of bistability of resting and regular spiking dynamics. We confirm these predictions experimentally for different neurons using dynamic patch clamp recordings to artificially change the leak conductance. Interestingly, the neuronal excitability type can also be switched dynamically via activation of shunting synapses, which we mimicked experimentally by bath application of GABA. These results imply that inhibitory cells can dynamically control the neuronal excitability type of postsynaptic neurons and as a consequence their synchronization properties. In particular, we show that inhibition can separately synchronize several coexisting sub-populations of excitatory neurons. Moreover, the maximal amount of synchrony in the network can be efficiently regulated by dynamically forcing the neurons into the region of bistability. In conclusion, inhibition-induced dynamic neuronal excitability switching provides a mechanism for flexible and activity controlled dynamic formation of synchronized neuronal cell assemblies.

  11. Mesmerising mirror neurons.

    Science.gov (United States)

    Heyes, Cecilia

    2010-06-01

    Mirror neurons have been hailed as the key to understanding social cognition. I argue that three currents of thought-relating to evolution, atomism and telepathy-have magnified the perceived importance of mirror neurons. When they are understood to be a product of associative learning, rather than an adaptation for social cognition, mirror neurons are no longer mesmerising, but they continue to raise important questions about both the psychology of science and the neural bases of social cognition. PMID:20167276

  12. Artifacts produced during electrical stimulation of the vestibular nerve in cats. [autonomic nervous system components of motion sickness

    Science.gov (United States)

    Tang, P. C.

    1973-01-01

    Evidence is presented to indicate that evoked potentials in the recurrent laryngeal, the cervical sympathetic, and the phrenic nerve, commonly reported as being elicited by vestibular nerve stimulation, may be due to stimulation of structures other than the vestibular nerve. Experiments carried out in decerebrated cats indicated that stimulation of the petrous bone and not that of the vestibular nerve is responsible for the genesis of evoked potentials in the recurrent laryngeal and the cervical sympathetic nerves. The phrenic response to electrical stimulation applied through bipolar straight electrodes appears to be the result of stimulation of the facial nerve in the facial canal by current spread along the petrous bone, since stimulation of the suspended facial nerve evoked potentials only in the phrenic nerve and not in the recurrent laryngeal nerve. These findings indicate that autonomic components of motion sickness represent the secondary reactions and not the primary responses to vestibular stimulation.

  13. Head stabilization measurements as a potential evaluation tool for comparison of persons with TBI and vestibular dysfunction with healthy controls.

    Science.gov (United States)

    Sessoms, Pinata H; Gottshall, Kim R; Sturdy, Jordan; Viirre, Erik

    2015-03-01

    A large percentage of persons with traumatic brain injury incur some type of vestibular dysfunction requiring vestibular physical therapy. These injuries may affect the natural ability to stabilize the head while walking. A simple method of utilizing motion capture equipment to measure head movement while walking was used to assess improvements in head stabilization of persons undergoing computerized vestibular physical therapy and virtual reality training for treatment of their vestibular problems. Movement data from the head and sacrum during gait were obtained over several visits and then analyzed to determine improved oscillatory head movement relative to the sacrum. The data suggest that, over time with treatment, head stabilization improves and moves toward a pattern similar to that of a healthy control population. This simple analysis of measuring head stability could be transferred to smaller, portable systems that are easily utilized to measure head stability during gait for use in gait assessment and physical therapy training. PMID:25747644

  14. Internet-based vestibular rehabilitation for adults aged 50 years and over: a protocol for a randomised controlled trial

    OpenAIRE

    Geraghty, Adam W A; Kirby, Sarah; Essery, Rosie; Little, Paul; Bronstein, Adolfo; Turner, David,; Stuart, Beth; Andersson, Gerhard; Carlbring, Per; Yardley, Lucy

    2014-01-01

    Introduction Dizziness is highly prevalent in older adults and can lead to falls, fear of falling, loss of confidence, anxiety and depression. Vestibular rehabilitation (VR) exercises are effective in reducing dizziness due to vestibular dysfunction, but access to trained therapists is limited. Providing dizzy patients with booklets teaching them how to carry out VR exercises has been shown to be a cost-effective way of managing dizziness in primary care. Internet-based intervention deliv...

  15. An ENU-Induced Mutation of Cdh23 Causes Congenital Hearing Loss, but No Vestibular Dysfunction, in Mice

    OpenAIRE

    Manji, Shehnaaz S.M.; Miller, Kerry A.; Williams, Louise H; Andreasen, Lotte; Siboe, Maria; Rose, Elizabeth; Bahlo, Melanie; Kuiper, Michael; Dahl, Hans-Henrik M.

    2011-01-01

    Mutations in the human cadherin 23 (CDH23) gene cause deafness, neurosensory, autosomal recessive 12 (DFNB12) nonsyndromic hearing loss or Usher syndrome, type 1D (characterized by hearing impairment, vestibular dysfunction, and visual impairment). Reported waltzer mouse strains each harbor a Cdh23-null mutation and present with hearing loss and vestibular dysfunction. Two additional Cdh23 mouse mutants, salsa and erlong, each carry a homozygous Cdh23 missense mutation and have progressive he...

  16. Hearing outcomes of vestibular schwannoma patients managed with 'wait and scan': predictive value of hearing level at diagnosis

    DEFF Research Database (Denmark)

    Stangerup, S-E; Tos, M; Thomsen, J; Caye-Thomasen, P

    2010-01-01

    This study aimed to evaluate the predictive value of both hearing level (at various frequencies) and speech discrimination for forecasting hearing outcome after a period of observation, in patients with vestibular schwannoma.......This study aimed to evaluate the predictive value of both hearing level (at various frequencies) and speech discrimination for forecasting hearing outcome after a period of observation, in patients with vestibular schwannoma....

  17. Evidence for cortical visual substitution of chronic bilateral vestibular failure (an fMRI study).

    Science.gov (United States)

    Dieterich, Marianne; Bauermann, Thomas; Best, Christoph; Stoeter, Peter; Schlindwein, Peter

    2007-08-01

    Bilateral vestibular failure (BVF) is a rare disorder of the labyrinth or the eighth cranial nerve which has various aetiologies. BVF patients suffer from unsteadiness of gait combined with blurred vision due to oscillopsia. Functional MRI (fMRI) in healthy subjects has shown that stimulation of the visual system induces an activation of the visual cortex and ocular motor areas bilaterally as well as simultaneous deactivations of multisensory vestibular cortex areas. Our question was whether the chronic absence of bilateral vestibular input (BVF) causes a plastic cortical reorganization of the above-described visual-vestibular interaction. We used fMRI to measure the differential effects of horizontal visual optokinetic stimulation (OKN) on activations and deactivations in 10 patients with BVF and compared their data directly to those of pairwise age- and sex-matched controls. We found that bilateral activation of the primary visual cortex (inferior and middle occipital gyri, Brodmann area BA 17, 18, 19), the motion-sensitive areas V5 in the middle and inferior temporal gyri (BA 37), and the frontal eye field (BA 8), the right paracentral and superior parietal lobule and the right fusiform and parahippocampal gyri was significantly stronger and the activation clusters were larger than that of the age-matched healthy controls. Small areas of BOLD signal decreases (deactivations), located primarily in the right posterior insula containing the parieto-insular vestibular cortex, were similar to those in the healthy controls. No other sensory brain areas showed unexpected activations or deactivations, e.g. the somatosensory or auditory cortex areas. Our finding of enhanced activations within the visual and ocular motor systems of BVF patients suggests that they might be correlated with an upregulation of visual sensitivity during tracking of visual motion patterns. Functionally, these enhanced activations are independent of optokinetic performance, since the mean slow-phase velocity of OKN in the BVF patients did not differ from that in normals. Although psychophysical and neurophysiological tests have provided various examples of how sensory loss in one modality leads to a substitutional increase of functional sensitivity in other modalities, this study presents the first evidence of visual substitution for vestibular loss by functional imaging. PMID:17575279

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

    Directory of Open Access Journals (Sweden)

    Anna Paula Batista de Ávila Pires

    2013-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Freddy Martel V

    2008-12-01

    Full Text Available Objetivo: Analizar los resultados iniciales de un estudio prospectivo en pacientes con schwanomas vestibulares tratados con radiocirugía en la Pontificia Universidad Católica de Chile. Material y método: Se presentan 17 pacientes portadores de schwanomas vestibulares esporádicos tratados con radiocirugía y seguidos entre 6 y 26 meses. El tratamiento fue realizado con acelerador lineal Varían clinac21 EX, con equipamiento Varían-Zmed. La dosis marginal administrada al tumor fue de 12 a 12,5 Gray El seguimiento a 6, 12 y 24 meses consta de resonancia magnética, audiometríay evaluación clínica. Resultados: La dosis marginal de irradiación usada fue entre 12y 12,5 Gray normalizada a la isodosis 70% u 80%. En todos los pacientes se documentó disminución de la captación de contraste del tumor y en 16 (94% se observaron áreas de necrosis centro tumoral. No hubo mortalidad, la preservación de audición útil fue 62,5% actuaría! a 2 años. No ha existido deterioro de la función de los nervios facial ni trigémino. Todos los pacientes que previamente estaban trabajando retornaron a sus labores en promedio 11,5 días luego del tratamiento. Conclusiones: Los resultados iniciales de esta serieison comparables a los resultados publicados en la literatura y refuerzan el demostrado rol de la radiocirugía en el tratamiento de los schwanomas vestibulares.Objective: To analyze the preliminary experience of radiosurgery for Vestibular Schwannomas at the Pontificia Universidad Católica de Chile. Material and methods: Thefirst 17 patients with sporadic Vestibular Schwannomas treated by radiosurgery at our institution are reponed. The marginal dose used was 12 to 12.5 Gy. prescribed at the 70 or 80 isodose Une. Patients were controlled at 6, 12 and 24 months with magnetic resonance, audiometric study and clinical examination. Results: In all of the 17 patients treated a decrease tumor enhancement on MR was demonstrated. In 16 patients (94% a pattern of central tumor necrosis was observed during the firsyear Actuaría! useful hearing was maintained in 62.5% at 2 year after treatment. Facial nerve function was maintained in all of the 15 patients with normal function at treatment (100%. Trigémina! function was maintained in all of the 14 patients (100% with previous normal trigeminal function. The mean time to return to work or normal activities was 11.5 days after treatment Conclusions: These preliminary results are comparable with results published in the literature and reinforce the demónstrate role oí radiosurgery in the management oí vestibular schwannomas.

  20. Reaching with the sixth sense: Vestibular contributions to voluntary motor control in the human right parietal cortex.

    Science.gov (United States)

    Reichenbach, Alexandra; Bresciani, Jean-Pierre; Bülthoff, Heinrich H; Thielscher, Axel

    2016-01-01

    The vestibular system constitutes the silent sixth sense: It automatically triggers a variety of vital reflexes to maintain postural and visual stability. Beyond their role in reflexive behavior, vestibular afferents contribute to several perceptual and cognitive functions and also support voluntary control of movements by complementing the other senses to accomplish the movement goal. Investigations into the neural correlates of vestibular contribution to voluntary action in humans are challenging and have progressed far less than research on corresponding visual and proprioceptive involvement. Here, we demonstrate for the first time with event-related TMS that the posterior part of the right medial intraparietal sulcus processes vestibular signals during a goal-directed reaching task with the dominant right hand. This finding suggests a qualitative difference between the processing of vestibular vs. visual and proprioceptive signals for controlling voluntary movements, which are pre-dominantly processed in the left posterior parietal cortex. Furthermore, this study reveals a neural pathway for vestibular input that might be distinct from the processing for reflexive or cognitive functions, and opens a window into their investigation in humans. PMID:26424179

  1. Further investigation of the spontaneous and evoked activity of the primary neurons of statoreceptors (and other receptors) of the labyrinth of the bullfrog before, during and after an extended period of weightlessness, including alternative intervals of artificial gravity

    Science.gov (United States)

    1977-01-01

    Vestibular neuron activity was examined by studying nerve stimulation and evoked response. A cooling element, applied to the nerve consisted of a silver hook through which a coolant fluid flowed. Temperature changes were recorded via microtermistors on an eight channel brush recorder, together with response. Diffusion of the cooling effect was measured, recovery time was assessed, and the nerve was then studied hystologically and ultrastructurally. Problems in frog preparation were discussed along with problems in maintaining healthy specimens and bacteria controlled aquaria.

  2. Kappe neurons, a novel population of olfactory sensory neurons

    OpenAIRE

    Ahuja, Gaurav; Nia, Shahrzad Bozorg; Zapilko, Veronika; Shiriagin, Vladimir; Kowatschew, Daniel; Oka, Yuichiro; Korsching, Sigrun I.

    2014-01-01

    Perception of olfactory stimuli is mediated by distinct populations of olfactory sensory neurons, each with a characteristic set of morphological as well as functional parameters. Beyond two large populations of ciliated and microvillous neurons, a third population, crypt neurons, has been identified in teleost and cartilaginous fishes. We report here a novel, fourth olfactory sensory neuron population in zebrafish, which we named kappe neurons for their characteristic shape. Kappe neurons ar...

  3. The extracisternal approach in vestibular schwannoma surgery and facial nerve preservation / A abordagem extracisternal na cirurgia de schwannoma vestibular e preservação do nervo facial

    Scientific Electronic Library Online (English)

    Eduardo A. S., Vellutini; André, Beer-Furlan; Roger S., Brock; Marcos Q. T., Gomes; Aldo, Stamm; Oswaldo Laercio M., Cruz.

    2014-12-01

    Full Text Available A técnica cirúrgica clássica para ressecção de schwannomas vestibulares enfatiza a anatomia microcirúrgica dos nervos cranianos. Acreditamos que o foco na preservação da membrana aracnóide pode servir como parâmetro seguro para a remoção do tumor. Método A abordagem extracisternal é descrita em det [...] alhe. Analisamos o prontuário de 120 pacientes tratados com esta técnica entre 2006 e 2012. Os resultados cirúrgicos foram baseados em extensão de ressecção, recorrência tumoral e função do nervo facial. Resultados Ressecção total foi obtida em 81% dos pacientes. O resultado global da função do nervo facial (House-Brackmann graus I-II) após um ano da cirurgia foi de 93%. Não houve recidiva em um seguimento médio de 4,2 anos. Conclusão A técnica extracisternal difere de outras descrições cirúrgicas no tratamento de schwannoma vestibular pois não requer a identificação do nervo facial, contanto que o plano de aracnóide seja preservado em toda circunferência do tumor. Abstract in english The classical surgical technique for the resection of vestibular schwannomas (VS) has emphasized the microsurgical anatomy of cranial nerves. We believe that the focus on preservation of the arachnoid membrane may serve as a safe guide for tumor removal. Method The extracisternal approach is descri [...] bed in detail. We reviewed charts from 120 patients treated with this technique between 2006 and 2012. Surgical results were evaluated based on the extension of resection, tumor relapse, and facial nerve function. Results Overall gross total resection was achieved in 81% of the patients. The overall postoperative facial nerve function House-Brackmann grades I-II at one year was 93%. There was no recurrence in 4.2 years mean follow up. Conclusion The extracisternal technique differs from other surgical descriptions on the treatment of VS by not requiring the identification of the facial nerve, as long as we preserve the arachnoid envelope in the total circumference of the tumor.

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

    OpenAIRE

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

    2005-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Ernesto Odriozola

    2009-11-01

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

  6. Neuronal Response Clamp

    Directory of Open Access Journals (Sweden)

    Avner Wallach

    2011-04-01

    Full Text Available Responses of individual neurons to ongoing input are highly variable, reflecting complex threshold dynamics. Experimental access to this threshold dynamics is required in order to fully characterize neuronal input-output relationships. The challenge is practically intractable using present day experimental paradigms due to the cumulative, nonlinear interactions involved. Here we introduce the Neuronal Response Clamp, a closed-loop technique enabling control over the instantaneous response probability of the neuron. The potential of the technique is demonstrated by showing direct access to threshold dynamics of cortical neuron in-vitro using extracellular recording and stimulation, over timescales ranging from seconds to many hours. Moreover, the method allowed us to expose the sensitivity of threshold dynamics to spontaneous input from the network in which the neuron is embedded. The Response Clamp technique follows the rationale of the voltage-clamp and dynamic-clamp approaches, extending it to the neuron's spiking behavior. The general framework offered here is applicable in the study of other neural systems, beyond the single neuron level.

  7. Phosphoribosomes for fingerprinting neurons.

    Science.gov (United States)

    Dietrich, Marcelo O; Horvath, Tamas L

    2012-11-21

    The mammalian brain comprises a diverse variety of cell types. Fine characterization of specific subpopulations of neurons, however, has been a technical challenge. Here, Knight et al. describe an elegant technique for high throughput of molecular profiling of activated hypothalamic neurons. PMID:23178116

  8. Attention and neuronal circuits.

    Science.gov (United States)

    Briggs, Farran

    2015-09-01

    Visual attention has a profound impact on perception, however we currently lack a neurobiological definition of attention. In other words, we lack an understanding of the cellular and circuit mechanisms underlying attentional modulation of neuronal activity in the brain. The main objective of my research is to understand how visual spatial attention alters the way in which neurons communicate with one another. Previously, my colleagues and I demonstrated that attention enhances the efficacy of signal transmission in the geniculocortical circuit. Through this work, we suggest that the mechanisms underlying attentional modulation of neuronal activity involve enhancement of signal transmission in neuronal circuits and increasing the signal-to-noise ratio of information transmitted in these circuits. Results from my lab indicate that these mechanisms can explain attentional modulations in firing rate observed in primary visual cortical neurons. Our current research focuses on understanding the rules governing attentional modulation of different functional circuits in the visual cortex. Preliminary results suggest that attention differentially regulates the activity of neuronal circuits dependent on the types of information conveyed within those circuits. Overall, our results support a mechanistic definition of attention as a process that alters the dynamics of communication in specific neuronal circuits. I believe this circuit-level understanding of how attention alters neuronal activity is required in order to develop more targeted and effective treatments for attention deficits. PMID:26327102

  9. Corticospinal mirror neurons.

    Science.gov (United States)

    Kraskov, A; Philipp, R; Waldert, S; Vigneswaran, G; Quallo, M M; Lemon, R N

    2014-01-01

    Here, we report the properties of neurons with mirror-like characteristics that were identified as pyramidal tract neurons (PTNs) and recorded in the ventral premotor cortex (area F5) and primary motor cortex (M1) of three macaque monkeys. We analysed the neurons' discharge while the monkeys performed active grasp of either food or an object, and also while they observed an experimenter carrying out a similar range of grasps. A considerable proportion of tested PTNs showed clear mirror-like properties (52% F5 and 58% M1). Some PTNs exhibited 'classical' mirror neuron properties, increasing activity for both execution and observation, while others decreased their discharge during observation ('suppression mirror-neurons'). These experiments not only demonstrate the existence of PTNs as mirror neurons in M1, but also reveal some interesting differences between M1 and F5 mirror PTNs. Although observation-related changes in the discharge of PTNs must reach the spinal cord and will include some direct projections to motoneurons supplying grasping muscles, there was no EMG activity in these muscles during action observation. We suggest that the mirror neuron system is involved in the withholding of unwanted movement during action observation. Mirror neurons are differentially recruited in the behaviour that switches rapidly between making your own movements and observing those of others. PMID:24778371

  10. Glutamate gated spiking Neuron Model

    OpenAIRE

    Deka, Krisha M; Roy, Soumik

    2014-01-01

    Background Biological neuron models mainly analyze the behavior of neural networks. Neurons are described in terms of firing rates viz an analog signal. Purpose The Izhikevich neuron model is an efficient, powerful model of spiking neuron. This model is a reduction of Hodgkin-Huxley model to a two variable system and is capable of producing rich firing patterns for many biological neurons. Methods In this paper, the Regular Spiking (RS) neuron firing pattern is used to simulate the spiking of...

  11. Cerebellar ataxia, neuropathy, and vestibular areflexia syndrome: a slowly progressive disorder with stereotypical presentation.

    Science.gov (United States)

    Cazzato, Daniele; Bella, Eleonora Dalla; Dacci, Patrizia; Mariotti, Caterina; Lauria, Giuseppe

    2016-02-01

    Cerebellar ataxia, neuropathy and vestibular areflexia syndrome (CANVAS) is a newly described condition with onset in adulthood, characterized by progressive balance impairment and sensory disturbances in the lower limbs, which can severely affect patients' quality of life. Its pathogenesis remains obscure and the diagnosis challenging. We described four patients complaining of slowly progressive gait unbalance and sensory disturbances at the feet followed, after a period ranging 2-6 years, by cerebellar dysfunction. All patients showed gait and limb ataxia, positive Romberg sign, cerebellar dysarthria, gaze-evoked nystagmus, absent deep tendon reflexes, and impaired vibratory sensation. Nerve conduction studies revealed axonal sensory neuropathy, brain magnetic resonance imaging showed cerebellar atrophy, and otoneurological investigation demonstrated bilateral vestibular areflexia with impaired vestibulo-ocular reflexes. The diagnosis of CANVAS should be suspected on clinical ground based on homogeneous course of symptoms and signs, and addressed by video-oculography eye movement recording. PMID:26566912

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

    Directory of Open Access Journals (Sweden)

    Martin Göttlich

    2014-01-01

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

  13. Effects of vestibular and neck proprioceptive stimulation on posture as a function of hypnotizability.

    Science.gov (United States)

    Santarcangelo, Enrica L; Scattina, Eliana; Orsini, Paolo; Bruschini, Luca; Ghelarducci, Brunello; Manzoni, Diego

    2008-04-01

    Previous studies on the role of hypnotizability in postural control indicate that the body sway of subjects with high or low hypnotizability to hypnosis is differentially modulated by eye closure. The aim of this study was to investigate whether hypnotizability also modulates the postural response to electrical vestibular stimulation and to head rotation in nonhypnotized individuals. The center of pressure (CoP) displacements were monitored in highs and lows standing on a stabilometric platform with closed eyes during basal conditions and electrical vestibular stimulation in 3 different positions of the head. Results showed that the CoP stimulus-locked displacements as well as the CoP mean position, area, and mean velocity were similar in highs and lows, but only in lows did the head position modulate the mean velocity. This finding might reflect a difference in sensory-motor integration between the 2 groups. PMID:18307127

  14. Bio-Inspired Micro-Fluidic Angular-Rate Sensor for Vestibular Prostheses

    Directory of Open Access Journals (Sweden)

    Charalambos M. Andreou

    2014-07-01

    Full Text Available This paper presents an alternative approach for angular-rate sensing based on the way that the natural vestibular semicircular canals operate, whereby the inertial mass of a fluid is used to deform a sensing structure upon rotation. The presented gyro has been fabricated in a commercially available MEMS process, which allows for microfluidic channels to be implemented in etched glass layers, which sandwich a bulk-micromachined silicon substrate, containing the sensing structures. Measured results obtained from a proof-of-concept device indicate an angular rate sensitivity of less than 1 °/s, which is similar to that of the natural vestibular system. By avoiding the use of a continually-excited vibrating mass, as is practiced in today’s state-of-the-art gyroscopes, an ultra-low power consumption of 300 μW is obtained, thus making it suitable for implantation.

  15. A Low-Power ASIC Signal Processor for a Vestibular Prosthesis.

    Science.gov (United States)

    Toreyin, Hakan; Bhatti, Pamela T

    2016-06-01

    A low-power ASIC signal processor for a vestibular prosthesis (VP) is reported. Fabricated with TI 0.35 μm CMOS technology and designed to interface with implanted inertial sensors, the digitally assisted analog signal processor operates extensively in the CMOS subthreshold region. During its operation the ASIC encodes head motion signals captured by the inertial sensors as electrical pulses ultimately targeted for in-vivo stimulation of vestibular nerve fibers. To achieve this, the ASIC implements a coordinate system transformation to correct for misalignment between natural sensors and implanted inertial sensors. It also mimics the frequency response characteristics and frequency encoding mappings of angular and linear head motions observed at the peripheral sense organs, semicircular canals and otolith. Overall the design occupies an area of 6.22 mm (2) and consumes 1.24 mW when supplied with ± 1.6 V. PMID:26800546

  16. Left caloric vestibular stimulation as a tool to reveal implicit and explicit parameters of body representation.

    Science.gov (United States)

    Sedda, A; Tonin, D; Salvato, G; Gandola, M; Bottini, G

    2016-04-01

    Homeostatic parameters, such as temperature, are related to body representation. In this study, we measured whether caloric vestibular stimulation (CVS) alters body temperature and tactile processing, and if in the direction predicted by a holistic body matrix representation. Skin temperature and tactile two-point discrimination (TPD) acuity were measured for both arms before, immediately after and with a delay from CVS. Participants were also administered a personality questionnaire and an anxiety inventory to rule out confounding factors. Two control experiments were planned to exclude casual variations. Our results show that temperature drops significantly in both arms after CVS. CVS also induces a bilateral improvement in tactile acuity (even though not immediately after but in the delayed condition). Finally, these effects are not due to learning, as demonstrated by the control experiment. In summary, our results suggest that vestibular stimulation updates body representation, supporting the evidence in favor of a body matrix. PMID:26837046

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

    Directory of Open Access Journals (Sweden)

    Brahim Tighilet

    2014-01-01

    UVN induced a bilateral decrease in binding density of the agonist [3H]-Nα−Methylhistamine to H3R in the tuberomammillary nuclei (TMN at one week postlesion, with a predominant down-regulation in the ipsilateral TMN. The bilateral decrease remained at the three weeks survival time and became symmetric. Concerning brainstem structures, binding density in the VN, the prepositus hypoglossi, the subdivisions of the inferior olive (IO decreased unilaterally on the ipsilateral side at one week and bilaterally 3 weeks after UVN. Similar changes were observed in the subdivisions of the solitary nucleus (SN only one week after the lesion. These findings indicate vestibular lesion induces plasticity of the histamine H3R, which could contribute to vestibular function recovery.

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

    Science.gov (United States)

    Clark, T. K.; Peters, B.; Gadd, N. E.; De Dios, Y. E.; Wood, S.; Bloomberg, J. J.; Mulavara, A. P.

    2016-01-01

    Introduction: During space exploration missions astronauts are exposed to a series of novel sensorimotor environments, requiring sensorimotor adaptation. Until adaptation is complete, sensorimotor decrements occur, affecting critical tasks such as piloted landing or docking. Of particularly interest are locomotion tasks such as emergency vehicle egress or extra-vehicular activity. While nearly all astronauts eventually adapt sufficiently, it appears there are substantial individual differences in how quickly and effectively this adaptation occurs. These individual differences in capacity for sensorimotor adaptation are poorly understood. Broadly, we aim to identify measures that may serve as pre-flight predictors of and individual's adaptation capacity to spaceflight-induced sensorimotor changes. As a first step, since spaceflight is thought to involve a reinterpretation of graviceptor cues (e.g. otolith cues from the vestibular system) we investigate the relationships between various measures of vestibular function in humans. Methods: In a set of 15 ground-based control subjects, we quantified individual differences in vestibular function using three measures: 1) ocular vestibular evoked myogenic potential (oVEMP), 2) computerized dynamic posturography and 3) vestibular perceptual thresholds. oVEMP responses are elicited using a mechanical stimuli approach. Computerized dynamic posturography was used to quantify Sensory Organization Tests (SOTs), including SOT5M which involved performing pitching head movements while balancing on a sway-reference support surface with eyes closed. We implemented a vestibular perceptual threshold task using the tilt capabilities of the Tilt-Translation Sled (TTS) at JSC. On each trial, the subject was passively roll-tilted left ear down or right ear down in the dark and verbally provided a forced-choice response regarding which direction they felt tilted. The motion profile was a single-cycle sinusoid of angular acceleration with a duration of 5 seconds (frequency of 0.2 Hz), which was selected as it requires sensory integration of otolith and semicircular canal cues. Stimuli direction was randomized and magnitude was determined using an adaptive sampling procedure. One hundred trials were provided and each subject's responses were fit with a psychometric curve to estimate the subject's threshold. Results: Roll tilt perceptual thresholds at 0.2 Hz ranged from 0.5 degrees to 1.82 degrees across the 15 subjects (geometric mean of 1.04 degrees), consistent with previous studies. The inter-individual variability in thresholds may be able to help explain individual differences observed in sensorimotor adaptation to spaceflight. Analysis is ongoing for the oVEMPS and computerized dynamic posturography to identify relationships between the various vestibular measures. Discussion: Predicting individual differences in sensorimotor adaptation is critical both for the development of personalized countermeasures and mission planning. Here we aim to develop a basis of vestibular tests and parameters which may serve as predictors of individual differences in sensorimotor adaptability through studying the relationship between these measures.

  19. DIZZINESS OF ISCHEMIC GENESIS: DESCRIPTION OF VESTIBULAR DISORDERS AND POSSIBILITY OF THERAPY

    Directory of Open Access Journals (Sweden)

    N. S. Alekseeva

    2015-12-01

    Full Text Available Aim. To reveal the peculiarities of peripheral and central vestibular disorders in patients with mild dizziness in initial and reversible cerebrovascular diseases and estimate the efficacy of dizziness therapy with betahistine dihydrochloride (Betaserc, Solvay Pharma.Material and methods: 40 patients (all women with dizziness were studied. Neurological and otoneurological examination was done; central hemodynamics and number of vascular indices were analyzed. Therapy with Betaserc in daily dose of 48 mg was held during 2 months.Results. Dysfunction of both peripheral and central parts of vestibular analyzer was revealed in all patients. Most patients complained on diminished hearing, buzzing in ears and head, imbalance while walking. All patients mentioned the performance impairment, easy fatigability, change of mood. Therapy with Betaserc improved the condition of 97% patients with dizziness, the intensity of associated acoustic disturbances considerably reduced.Conclusion. Betaserc is an effective drug for dizziness therapy in patients with initial and reversible cerebrovascular diseases.

  20. Variation in the gaze, caloric test and vestibular-evoked myogenic potential with advancing age

    Directory of Open Access Journals (Sweden)

    Sharda Sarda

    2014-01-01

    Full Text Available Objectives: The present study was aimed to investigate age related changes on Caloric test, Gaze Test and Vestibular Evoked Myogenic Potential (cVEMP. Materials and Methods: The participants included 50 individuals ranging from 20-70 years having no complaint of dizziness or any major illness. The basic audiological test battery was carried out followed by Caloric test, Gaze Test and the VEMP. Results: There was no consistent pattern seen on the caloric test and gaze test with advancing age while VEMP showed significant increase in latency and decrease in amplitude of both P13 and N23 as the age advances. Discussion: The comparison of the mean SPV values do not show an age related pattern because the caloric test does not challenge the semicircular canal system enough so as to reveal its defects. The age related changes in the cVEMP parameters could be attributed to the age related degeneration in the vestibular sense organ

  1. Facial demyelinating neuropathy caused by previous stereotactic irradiation to a vestibular schwannoma

    International Nuclear Information System (INIS)

    This is a report of a vestibular schwannoma patient who received surgical treatment 8 months after stereotactic gamma knife irradiation. The previous irradiation caused facial demyelinating neuropathy of the facial nerve, and it made the identification and preservation of the nerve during subsequent microsurgery difficult. In the affected nerve segments, stimulation even to the exposed facial nerve evoked only attenuated response or no responses in electromyography. As a result, the flattened facial nerve located behind the tumor was indistinguishable. In order to prevent damage of the facial nerve, subcapsular tumor removal had to be performed at the demyelinated segments. This sequela of stereotactic irradiation should be considered when the irradiation is planned as a primary treatment modality of a vestibular schwannoma, in particular in young patients who will eventually receive another surgery afterwards. (author)

  2. Caracterização clínica de idosos com disfunção vestibular crônica Clinical evaluation of elderly people with chronic vestibular disorder

    Directory of Open Access Journals (Sweden)

    Juliana Maria Gazzola

    2006-08-01

    Full Text Available A tontura de origem vestibular é comum entre idosos. OBJETIVO: Caracterizar idosos com disfunção vestibular crônica em relação aos dados sociodemográficos, clínico-funcionais e otoneurológicos. MATERIAL E MÉTODO: Estudo de casos que incluiu 120 idosos com disfunção vestibular crônica. Foram realizadas análises descritivas simples. RESULTADOS: A 5,77±amostra apresentou maioria feminina (68,3%, com média etária de 73,40 1,84±anos. O número médio de doenças associadas ao quadro vestibular foi de 3,83 e o número médio de medicamentos foi de 3,86±2,27. O exame vestibular evidenciou vestibulopatia periférica deficitária unilateral (29,8% e as hipóteses diagnósticas prevalentes foram labirintopatia metabólica (40,0% e vertigem posicional paroxística benigna (36,7%. Para 52 (43,3% pacientes, a tontura começou há mais de 5 anos. Em relação à queda, 64 idosos (53,3% apresentaram pelo menos uma queda no último ano e 35 (29,2% referiram quedas recorrentes. CONCLUSÕES: A amostra foi representada por maioria feminina e média etária elevada, com doenças associadas ao quadro vestibular e polifarmacoterapia. As vestibulopatias e a topografia mais freqüentes foram, respectivamente, labirintopatia metabólica e vascular e síndrome periférica deficitária unilateral. A tontura é uma condição crônica e a associação de vestibulopatias é comum. A ocorrência de quedas é prevalente na população de idosos com disfunção vestibular crônica.Dizziness is common among the elderly. AIM: To characterize social, demographic, clinical, functional and otoneurological data in elderly patients with chronic vestibular disorder. METHOD: A sequential study of 120 patients with chronic vestibular disorder. Simple descriptive analyses were undertaken. RESULTS: Most of the patients were female (68.3% with a mean age of 73.40±5.77 years. The average number of illnesses associated with the vestibular disorder was 3.83±1.84; the patients were taking on average 3.86±2.27 different medications. The most prevalent diagnosis on the vestibular exam was unilateral vestibular loss (29.8% and the most prevalent etiology was metabolic vestibulopathy (40.0% followed by benign paroxysmal positional vertigo (36.7%. Fifty-two patients (43.3% had experienced dizziness for 5 years or more. Sixty-four patients (53.3% had at least one fall in the last year and thirty-five (29.2% had recurrent falls. CONCLUSIONS: Most of the sample included females with associated diseases, and using many different drugs. The most prevalent vestibular diseases were metabolic and vascular labyrinth conditions. Dizziness is a chronic symptom in elderly patients. The association of two vestibular diseases is common. Falls are prevalent in chronic dizzy elderly patients.

  3. A 1-year follow-up study with C-VEMPs, O-VEMPs and video head impulse testing in vestibular neuritis.

    Science.gov (United States)

    Magliulo, Giuseppe; Iannella, Giannicola; Gagliardi, Silvia; Re, Massimo

    2015-11-01

    The aim of this paper was to evaluate prospectively, in a group of patients affected by VN, a diagnostic protocol employing C-VEMPs, O-VEMPs and vHIT together. The diagnosis of vestibular neurolabyrinthitis was based on the clinical history, absence of associated auditory or neurological symptoms, and a neuro-otological examination with an evaluation of lateral semicircular canal function using the Fitzgerald-Hallpike caloric vestibular test and ice test. Our series revealed an incidence of 55% of superior and inferior vestibular neurolabyrinthitis, 40% of superior vestibular neurolabyrinthitis and 5% of inferior vestibular neurolabyrinthitis. These data, however, comprised different degrees of vestibular involvement considering the evaluation of each single vestibular end-organ with potential different prognosis. Four patients had only deficits of the horizontal and superior semicircular canals or their ampullary nerves. The implementation of C-VEMPs, O-VEMPs and vHIT in a vestibular diagnostic protocol has made possible to observe patients with ampullary VN, unidentifiable with other types of vestibular exams. The effect of age seems to have some impact on the recovery. When recovery firstly involves the utricular and saccular nerves and subsequently the ampullary nerves, it may be reasonable to expect a more favorable and successful outcome. PMID:25476197

  4. Rescue of hearing and vestibular function in a mouse model of human deafness

    OpenAIRE

    Lentz, Jennifer J.; Jodelka, Francine M.; Hinrich, Anthony J.; McCaffrey, Kate E.; Farris, Hamilton E.; Spalitta, Mathew J.; Bazan, Nicolas G.; Duelli, Dominik M.; Rigo, Frank; Hastings, Michelle L.

    2013-01-01

    Hearing impairment is the most common sensory disorder, with congenital hearing impairment present in ~1 in 1000 newborns1, and yet there is no cellular cure for deafness. Hereditary deafness is often mediated by the developmental failure or degeneration of cochlear hair cells2. Until now, it was not known whether such congenital failures could be mitigated by therapeutic intervention3-5. Here we show that hearing and vestibular function can be rescued in a mouse model of human...

  5. Functional Results Following Treatment of Vestibular Schwannomas: Comparative Study between Surgery and Radiation

    OpenAIRE

    Rizk, Ahmed Rizk Abdel Khalek

    2015-01-01

    Objective: Treatment of vestibular Schwannomas, represent a matter of strong controversy, and to date no class I evidence can support the benefit of certain treatment modality over the others. Expectant treatment, microsurgery, and gamma knife radiosurgery represent the most important options to be considered. The main goal of the present study is to compare the functional outcome after gamma knife and surgical treatment in the long-term follow up. Patients and Methods: 269 patient...

  6. Dynamic re-weighting of visual and vestibular cues during self-motion perception

    OpenAIRE

    Fetsch, Christopher R.; Turner, Amanda H.; DeAngelis, Gregory C; ANGELAKI, DORA E.

    2009-01-01

    The perception of self-motion direction, or heading, relies on integration of multiple sensory cues, especially from the visual and vestibular systems. However, the reliability of sensory information can vary rapidly and unpredictably, and it remains unclear how the brain integrates multiple sensory signals given this dynamic uncertainty. Human psychophysical studies have shown that observers combine cues by weighting them in proportion to their reliability, consistent with statistically opti...

  7. Mechanoelectrical transducer has discrete conductances in the chick vestibular hair cell.

    OpenAIRE

    Ohmori, H.

    1984-01-01

    Properties of mechanoelectrical transduction were studied at the single-cell level by applying a whole-cell recording variation of the patch-clamp technique to dissociated vestibular hair cells of chicks. The hair bundle was directly stimulated by a glass rod, and transduction currents were recorded from the cell body. After a triangular movement of the stimulating probe, the transduction current was generated stepwise between discrete levels of amplitude. The minimum step amplitude was -1.8 ...

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

    OpenAIRE

    Marc Jamon

    2014-01-01

    This chapter reviews the knowledge about the adaptation to Earth gravity during the development of mammals. The impact of early exposure to altered gravity is evaluated at the level of the functions related to the vestibular system, including postural control, homeostatic regulation, and spatial memory. The hypothesis of critical periods in the adaptation to gravity is discussed. Demonstrating a critical period requires removing the gravity stimulus during delimited time windows, what is impo...

  9. Effects of vestibular nerve transection on the calcium incorporation of fish otoliths

    Science.gov (United States)

    Anken, Ralf H.; Edelmann, Elke; Rahmann, Hinrich

    2001-08-01

    Previous investigations revealed that the growth of fish inner ear otoliths (otolith size and calcium-incorporation) depends on the amplitude and the direction of gravity, suggesting the existence of a (negative) feedback mechanism. In search for the regulating unit, the vestibular nerve was transected unilaterally in neonate swordtail fish ( Xiphophorus helleri) which were subsequently incubated in the calcium-tracer alizarin-complexone. Calcium incorporation ceased on the transected head sides, indicating that calcium uptake is neurally regulated.

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

    OpenAIRE

    Ramma Lebogang; Ibekwe Titus S

    2012-01-01

    Abstracts Background To investigate the Cochleo-vestibular clinical and audiometric findings in Multi and Extreme Drug Resistance(MDR and XDR) tuberculosis(TB) patients on treatment and make recommendations. Methods A cross-sectional study of adult MDR and XDR-TB patients was conducted in a general hospital in Cape-Town-South-Africa. Ethical approval was secured and all consenting patients administered with pretested and validated questionnaire under the guidance of International Classificati...

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

    OpenAIRE

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

    2014-01-01

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

  12. Mutational ataxia resulting from abnormal vestibular acquisition and processing is partially compensated for.

    Science.gov (United States)

    Kopecky, Benjamin; Decook, Rhonda; Fritzsch, Bernd

    2012-04-01

    Due to the multisensory input into the balance system, the loss of one input, such as an ear, can generally be compensated for. However, when a mismatch or incomplete loss of inputs occurs, the ability to compensate for the stimulus misrepresentation may be compromised. The inner ear and cerebellum are important input and processing centers for balance but no genetic models have been generated to assess balance or compensation in the abnormal development of both these organs/brain areas. Important to their formation is regulation of proliferation mediated by the proto-oncogene N-Myc. Conditional knockouts (CKOs) of N-Myc using Tg(Pax2-Cre) have a misshapen and smaller ear with a fused utricle, saccule, and cochlea and absent horizontal canal, aberrant cochlear and vestibular innervations, and a size reduction in the cerebellum. CKOs are viable with obvious behavioral deficits, including circling behavior and unstable gait. To test the degree of ataxia and possible compensation of vestibular defects in these mutant mice, we use the Noldus Catwalk System to assess the gait of Tg(Pax2-Cre) N-Myc CKOs over five months. N-Myc CKOs perform worse than control littermates, in particular, in step regularity. We show that disrupting one member of the Myc family during embryonic development coincides with a differential loss of function in the cochlea compared to the vestibular apparatus. In addition, we show that the distortion in the ear morphology combined with a reduction of the cerebellum, rather than a complete loss of the vestibular-cerebellar pathway, leads to partial behavioral compensation that remains unchanged over time. PMID:22309445

  13. Habituation to novel visual vestibular environments with special reference to space flight

    Science.gov (United States)

    Young, L. R.; Kenyon, R. V.; Oman, C. M.

    1981-01-01

    The etiology of space motion sickness and the underlying physiological mechanisms associated with spatial orientation in a space environment were investigated. Human psychophysical experiments were used as the basis for the research concerning the interaction of visual and vestibular cues in the development of motion sickness. Particular emphasis is placed on the conflict theory in terms of explaining these interactions. Research on the plasticity of the vestibulo-ocular reflex is discussed.

  14. Strong Static Magnetic Fields Elicit Swimming Behaviors Consistent with Direct Vestibular Stimulation in Adult Zebrafish

    OpenAIRE

    Ward, Bryan K.; Tan, Grace X-J; Roberts, Dale C.; Della Santina, Charles C.; Zee, David S; CAREY, JOHN P.

    2014-01-01

    Zebrafish (Danio rerio) offer advantages as model animals for studies of inner ear development, genetics and ototoxicity. However, traditional assessment of vestibular function in this species using the vestibulo-ocular reflex requires agar-immobilization of individual fish and specialized video, which are difficult and labor-intensive. We report that using a static magnetic field to directly stimulate the zebrafish labyrinth results in an efficient, quantitative behavioral assay in free-swim...

  15. Diagnostic Value of Vestibular Evoked Myogenic Potentials in Endolymphatic Hydrops: A Meta-Analysis

    OpenAIRE

    Sulin Zhang,; Yangming Leng; Bo Liu; Hao Shi; Meixia Lu; Weijia Kong

    2015-01-01

    In this study, we evaluated the clinical diagnostic value of vestibular evoked myogenic potentials (VEMPs) for endolymphatic hydrops (EH) by systematic review and Meta-analysis. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio and area under summary receiver operating characteristic curves (AUC) were calculated. Subgroup analysis and publication bias assessment were also conducted. The pooled sensitivity and the specificity were ...

  16. Vibration-Induced Nystagmus in Patients with Unilateral Peripheral Vestibular Disorders

    OpenAIRE

    Xie, Sujiang; Guo, Jia; Wu, Ziming; Qiang, Dongchang; Huang, Jing; Zheng, Yingjuan; Yao, Qin; Chen, Shan; Tian, Dawei

    2013-01-01

    This study was done to clarify the clinical significance of vibration-induced nystagmus (VIN) and to calculate the sensitivity and the specificity of the vibration test. One hundred and twelve patients with unilateral peripheral vestibular disorders and thirty normal subjects were enrolled into this study. However, patients with spontaneous nystagmus were excluded. Vibration stimuli (approximately 100 Hz) were presented to the mastoids and the forehead. Patients and normal subjects also under...

  17. Kinesthetic and Vestibular Information Modulate Alpha Activity during Spatial Navigation: A Mobile EEG Study

    Directory of Open Access Journals (Sweden)

    Benedikt Valerian Ehinger

    2014-02-01

    Full Text Available In everyday life, spatial navigation involving locomotion provides congruent visual, vestibular and kinesthetic information that need to be integrated. Yet, previous studies on human brain activity during navigation focus on stationary setups, neglecting vestibular and kinesthetic feedback. The aim of our work is to uncover the influence of those sensory modalities on cortical processing. We developed a fully immersive virtual reality setup combined with high-density mobile electroencephalography (EEG. Participants traversed one leg of a triangle, turned on the spot, continued along the second leg and finally indicated the location of their starting position. Vestibular and kinesthetic information was provided either in combination, as isolated sources of information or not at all within a 2x2 full factorial intra-subjects design. EEG data were processed by clustering independent components, and time-frequency spectrograms were calculated. In parietal, occipital and temporal clusters, we detected alpha suppression during the turning movement, which is associated with a heightened demand of visuo-attentional processing, and closely resembles results reported in previous stationary studies. This decrease is present in all conditions and therefore seems to generalize to more natural settings. Yet, in incongruent conditions, when different sensory modalities did not match, the decrease is significantly stronger. Additionally, in more anterior areas, we found that providing only vestibular but no kinesthetic information results in alpha increase. These observations demonstrate that stationary experiments omit important aspects of sensory feedback. Therefore, it is important to develop more natural experimental settings in order to capture a more complete picture of neural correlates of spatial navigation.

  18. Kinesthetic and vestibular information modulate alpha activity during spatial navigation: a mobile EEG study.

    Science.gov (United States)

    Ehinger, Benedikt V; Fischer, Petra; Gert, Anna L; Kaufhold, Lilli; Weber, Felix; Pipa, Gordon; König, Peter

    2014-01-01

    In everyday life, spatial navigation involving locomotion provides congruent visual, vestibular, and kinesthetic information that need to be integrated. Yet, previous studies on human brain activity during navigation focus on stationary setups, neglecting vestibular and kinesthetic feedback. The aim of our work is to uncover the influence of those sensory modalities on cortical processing. We developed a fully immersive virtual reality setup combined with high-density mobile electroencephalography (EEG). Participants traversed one leg of a triangle, turned on the spot, continued along the second leg, and finally indicated the location of their starting position. Vestibular and kinesthetic information was provided either in combination, as isolated sources of information, or not at all within a 2 × 2 full factorial intra-subjects design. EEG data were processed by clustering independent components, and time-frequency spectrograms were calculated. In parietal, occipital, and temporal clusters, we detected alpha suppression during the turning movement, which is associated with a heightened demand of visuo-attentional processing and closely resembles results reported in previous stationary studies. This decrease is present in all conditions and therefore seems to generalize to more natural settings. Yet, in incongruent conditions, when different sensory modalities did not match, the decrease is significantly stronger. Additionally, in more anterior areas we found that providing only vestibular but no kinesthetic information results in alpha increase. These observations demonstrate that stationary experiments omit important aspects of sensory feedback. Therefore, it is important to develop more natural experimental settings in order to capture a more complete picture of neural correlates of spatial navigation. PMID:24616681

  19. Clinical Evaluation of CyberKnife in the Treatment of Vestibular Schwannomas

    OpenAIRE

    Jo-Ting Tsai; Jia-Wei Lin; Chien-Min Lin; Yuan-Hao Chen; Hsin-I Ma; Yee-Min Jen; Yi-Hsun Chen; Da-Tong Ju

    2013-01-01

    Objective. This study assessed the posttreatment tumor control and auditory function of vestibular schwannoma (VS) patients after CyberKnife (CK) and analyzed the possible prognostic factors of hearing loss. Methods. We retrospectively studied 117 VS patients, with Gardner-Robertson (GR) classification grades I to IV, who underwent CK between 2006 and 2012. Data including radiosurgery treatment parameters, pre- and postoperative tumor size, and auditory function were collected and examined. R...

  20. Selective atonal gene delivery improves balance function in a mouse model of vestibular disease

    OpenAIRE

    Schlecker, Christina; Praetorius, Mark; Brough, Douglas E.; Presler, Robert G.; Hsu, Chi; Plinkert, Peter K.; Staecker, Hinrich

    2011-01-01

    Loss of balance is often due to loss of vestibular hair cells. In mammals, regeneration of functional hair cells in the mature sensory epithelium is limited; therefore, loss of sensory cells can lead to debilitating balance problems. Delivery of the transcription factor atonal (atoh1) after aminoglycoside ototoxicity has previously been shown to induce the transdifferentiation of supporting cells into new hair cells and restore function. A problem with mouse aminoglycoside models is that the ...

  1. Turning Semicircular Canal Function on Its Head: Dinosaurs and a Novel Vestibular Analysis

    OpenAIRE

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

    2013-01-01

    Previous investigations have correlated vestibular function to locomotion in vertebrates by scaling semicircular duct radius of curvature to body mass. However, this method fails to discriminate bipedal from quadrupedal non-avian dinosaurs. Because they exhibit a broad range of relative head sizes, we use dinosaurs to test the hypothesis that semicircular ducts scale more closely with head size. Comparing the area enclosed by each semicircular canal to estimated body mass and to two different...

  2. Interference between postural control and mental task performance in patients with vestibular disorder and healthy controls

    OpenAIRE

    Yardley, L.; Gardner, M.; Bronstein, A; Davies, R.; Buckwell, D.; Luxon, L.

    2001-01-01

    OBJECTIVES - To determine whether interference between postural control and mental task performance in patients with balance system impairment and healthy subjects is due to general capacity limitations, motor control interference, competition for spatial processing resources, or a combination of these. METHOD - Postural stability was assessed in 48 patients with vestibular disorder and 24 healthy controls while they were standing with eyes closed on (a) a stable and (b) a moving platform...

  3. Impaired Tilt Perception in Parkinson’s Disease: A Central Vestibular Integration Failure

    Science.gov (United States)

    Bertolini, Giovanni; Wicki, Andrea; Baumann, Christian R.; Straumann, Dominik; Palla, Antonella

    2015-01-01

    Introduction Impaired balance control is a hallmark symptom in Parkinson’s disease (PD). Altered sensory-motor integration contributes to the deficiency. We aimed to determine whether impaired vestibular signal processing added to the disorder. We exposed patients (N = 11; 68±6y) and age-matched healthy subjects (hS: N = 19; 65±11y) on a motion platform in complete darkness to two consecutive forward tilt movements (12 series; N = 24; overall 288 trials) and asked them to indicate which tilt was perceived larger. By combing tilt movements with translations we manipulated vestibular sensory input in order to investigate whether putative impairment resulted from a deficiency of the sensory organs (semicircular canals in ‘single-SCC-cue-condition’, otoliths in ‘single-OT-cue-condition’) themselves or to a sensory integration failure (‘multi-cue-condition’). Results Tilt discrimination in the multi-cue-condition was inferior in patients compared to hS (p = 0.02). No significant differences between the two groups were found for both single-cue-conditions. Comparison of multi-cue-condition with a prediction resulting from the combination of both single-cue-conditions by optimal observer theory revealed that patients (p = 0.04), in contrast to hS, failed to efficiently combine SCC and OT information to improve tilt perception. Conclusion We found that PD patients distinguished forward tilts less precise than hS, suggesting impaired vestibular perception. Tilt discrimination in patients, moreover, did not improve as much as in hS in conditions where both SCC and OT information was available compared to conditions where only SCC or OT cues were activated. The latter provides evidence that tilt misperception in PD most likely results from an integration failure of vestibular signals. PMID:25874868

  4. The Role of 3-Canal Biomechanics in Angular Motion Transduction by the Human Vestibular Labyrinth

    OpenAIRE

    Ifediba, Marytheresa A.; Rajguru, Suhrud M.; Hullar, Timothy E; Rabbitt, Richard D

    2007-01-01

    The present work examines the role of the complex geometry of the human vestibular membranous labyrinth in the process of angular motion transduction by the semicircular canals. A morphologically descriptive mathematical model was constructed to address the biomechanical origins of temporal signal processing and directional coding in determining the inputs to the brain. The geometrical model was developed based on shrinkage-corrected temporal bone sections using a segmentation/data-fitting pr...

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

    OpenAIRE

    McCall Andrew A; Ishiyama Gail P; Lopez Ivan A; Bhuta Sunita; Vetter Steven; Ishiyama Akira

    2009-01-01

    Abstract Background We report the systematic analysis of the ultrastructural and cytological histopathology of vestibular endorgans acquired from labyrinthectomy in Meniere's disease. Methods 17 subjects with intractable Meniere's disease and ipsilateral non-serviceable hearing presenting to the Neurotology Clinic from 1997 to 2006 who chose ablative labyrinthectomy (average age = 62 years; range 29–83 years) participated. The average duration of symptoms prior to surgery was 7 years (range 1...

  6. Vestibular Neurectomy and Microvascular Decompression of the Cochlear Nerve in Meniere's Disease

    OpenAIRE

    Colletti, Vittorio; Fiorino, Francesco G.; Carner, Marco; Turazzi, Sergio

    1994-01-01

    Vestibular neurectomy (VN) results in a high success rate in the control of vertigo in Meniere's disease, although the subsequent fate of auditory function is fairly unpredictable. The present investigation reports the postoperative results obtained in a group of 30 subjects with a clinical diagnosis of Meniere's disease and vascular cross-compression of cranial nerve VIII. All subjects underwent VN using a retrosigmoid approach, and in half of them microvascular decompression (MVD) of the co...

  7. Usefulness of Some Current Balance Tests for Identifying Individuals with Disequilibrium Due to Vestibular Impairments

    OpenAIRE

    Helen S Cohen; Kimball, Kay T

    2008-01-01

    The goal of this study was to determine which of several clinical balance tests best identifies patients with vestibular disorders. We compared the scores of normals and patients on the Berg Balance Scale (Berg), Dynamic Gait Index (DGI), Timed Up and Go (TUG), Computerized Dynamic Posturography Sensory Organization Test (SOT), and a new obstacle avoidance test: the Functional Mobility Test (FMT). The study was performed in an out-patient balance laboratory at a tertiary care center. Subjects...

  8. O alcoolismo sob a ótica dos candidatos ao vestibular da Ufes

    OpenAIRE

    Maia Edinamara; Martins Ricardo L; César Márcia P; Baiôco Michela; Oliveira Rosiane G; Menandro Paulo RM; Garcia Maria LT; Macieira Marluce S

    2000-01-01

    INTRODUÇÃO: O trabalho analisou redações sobre alcoolismo de candidatos a dezessete cursos no vestibular de 1996 na Universidade Federal do Espírito Santo. O objetivo foi identificar concepções sobre causas, conseqüências e propostas de intervenção em relação ao fenômeno do alcoolismo. MÉTODOS: Foram analisadas 2.578 redações (47,7%). Na organização dos dados foi usado um roteiro contendo categorias de causas, conseqüências e propostas de intervenção, construído a partir do exame de um conjun...

  9. Optimization of Stimulus Characteristics for Vestibular Stochastic Resonance to Improve Balance Function

    Science.gov (United States)

    Mulavara, Ajitkumar; Fiedler, Matthew; Kofman, Igor; Acock, Keena; DeDios, Yiri E.; Heap, Erin; Peters, Brian; Wood, Scott; Serrador, Jorge; Cohen, Helen; Reschke, Millard; Bloomberg, Jacob

    2010-01-01

    Stochastic resonance (SR) is a mechanism by which noise can assist and enhance the response of neural systems to relevant sensory signals. Recent studies have shown that applying imperceptible stochastic noise electrical stimulation to the vestibular system significantly improved balance and ocular motor responses. The goal of this study was to optimize the amplitude of the stochastic vestibular signals for balance performance during standing on an unstable surface. Subjects performed a standardized balance task of standing on a block of 10-cm-thick medium-density foam with their eyes closed. Balance performance was measured using a force plate under the foam block and using inertial motion sensors placed on the torso and head segments. Stochastic electrical stimulation was applied to the vestibular system through electrodes placed over the mastoid process. Subjects were tested at seven amplitudes in the 0.01-30Hz frequency range. The root mean square of the signal increased by 30 microamperes for each +/-100 microampere increment in the current range of 0 - +/-700 microampere. Six balance parameters were calculated to characterize the performance of subjects during the baseline and the stimulus periods for all seven amplitudes. Optimal stimulus amplitude was determined as the one at which the ratio of parameters from the stimulus period to the baseline period for any amplitude range was less than that for the no stimulus condition on a minimum of four of six parameters. Results from this study showed that balance performance at the optimal stimulus amplitude showed significant improvement with the application of the vestibular SR stimulation. The amplitude of optimal stimulus for improving balance performance in normal subjects was in the range of +/-100 - +/-300 microamps.

  10. Neuronal-glial trafficking

    International Nuclear Information System (INIS)

    Full text: The name 'glia' originates from the Greek word for glue, because astro glia (or astrocytes) were thought only to provide an anatomical framework for the electrically-excitable neurones. However, awareness that astrocytes perform vital roles in protecting the neurones, which they surround, emerged from evidence that they act as neuroprotective K+-sinks, and that they remove potentially toxic extracellular glutamate from the vicinity of the neurones. The astrocytes convert the glutamate to non-toxic glutamine which is returned to the neurones and used to replenish transmitter glutamate. This 'glutamate-glutamine cycle' (established in the 1960s by Berl and his colleagues) also contributes to protecting the neurones against a build-up of toxic ammonia. Glial cells also supply the neurones with components for free-radical scavenging glutathione. Recent studies have revealed that glial cells play a more positive interactive role in furnishing the neurones with fuels. Studies using radioactive 14C, 13C-MRS and 15N-GCMS have revealed that glia produce alanine, lactate and proline for consumption by neurones, with increased formation of neurotransmitter glutamate. On neuronal activation the release of NH4+ and glutamate from the neurones stimulates glucose uptake and glycolysis in the glia to produce more alanine, which can be regarded as an 'alanine-glutamate cycle' Use of 14C-labelled precursors provided early evidence that neurotransmitter GABA may be partly derived from glial glutamine, and this has been confirmed recently in vivo by MRS isotopomer analysis of the GABA and glutamine labelled from 13C-acetate. Relative rates of intermediary metabolism in glia and neurones can be calculated using a combination of [1-13C] glucose and [1,2-13C] acetate. When glutamate is released by neurones there is a net neuronal loss of TCA intermediates which have to be replenished. Part of this is derived from carboxylation of pyruvate, (pyruvate carboxylase, PC) or phosphoenolpyruvate (PEP carboxykinase), to produce oxaloacetate, or via malic enzyme to produce malate. Of these the glial PC is thought to be the most important, and the proportion of pyruvate entering the TCA indirectly via carboxylation to that entering directly via pyruvate dehydrogenase was calculated to be 5 - 10 % using [2-13C] glucose

  11. Investigation of the vestibular aqueduct and the cochlear aqueduct by temboral bone CT scan

    International Nuclear Information System (INIS)

    The visualization of the vestibular aqueduct and the cochlear aqueduct was investigated by temporal bone CT scan. The vestibular aqueduct was visualized in horizontal CT sections of 70.0% of normal ears, 61.5% of ears with chronic otitis media, 58.3% of ears with combined hearing impairment, 66.7% of ears in cases of sudden deafness, 70.8% of ears of patients with sensorineural hearing impairment without sudden deafness, 71.4% of cases of vertigo without hearing impairment and 12.5% of both diseased and contralateral ears of patients with Meniere's disease. Only in Meniere's disease was the vestibular aqueduct less visible in the diseased than in the normal ear (P<0.01). The cochlear aqueduct was visible in coronal sections of 50.0% of normal ears, 76.9% of those with chronic otitis media, 58.3% of those with combined hearing impairment, 66.7% of those with sudden deafness 41.7% of those with sensorineural hearing impairment without sudden deafness, 50.0% of the diseased ears of patients with Meniere's disease, 37.5% of the contralateral ears of those with Meniere's disease and 64.3% of those with vertigo without hearing impairment. Although the cochlear aqueduct was thus highly demonstrable in patients with chronic otitis media or sudden deafness, the difference between the percentage of visualization in these diseased and in normal ears was not statistically significant. (author)

  12. Stochastic resonance in the synaptic transmission between hair cells and vestibular primary afferents in development.

    Science.gov (United States)

    Flores, A; Manilla, S; Huidobro, N; De la Torre-Valdovinos, B; Kristeva, R; Mendez-Balbuena, I; Galindo, F; Treviño, M; Manjarrez, E

    2016-05-13

    The stochastic resonance (SR) is a phenomenon of nonlinear systems in which the addition of an intermediate level of noise improves the response of such system. Although SR has been studied in isolated hair cells and in the bullfrog sacculus, the occurrence of this phenomenon in the vestibular system in development is unknown. The purpose of the present study was to explore for the existence of SR via natural mechanical-stimulation in the hair cell-vestibular primary afferent transmission. In vitro experiments were performed on the posterior semicircular canal of the chicken inner ear during development. Our experiments showed that the signal-to-noise ratio of the afferent multiunit activity from E15 to P5 stages of development exhibited the SR phenomenon, which was characterized by an inverted U-like response as a function of the input noise level. The inverted U-like graphs of SR acquired their higher amplitude after the post-hatching stage of development. Blockage of the synaptic transmission with selective antagonists of the NMDA and AMPA/Kainate receptors abolished the SR of the afferent multiunit activity. Furthermore, computer simulations on a model of the hair cell - primary afferent synapse qualitatively reproduced this SR behavior and provided a possible explanation of how and where the SR could occur. These results demonstrate that a particular level of mechanical noise on the semicircular canals can improve the performance of the vestibular system in their peripheral sensory processing even during embryonic stages of development. PMID:26926966

  13. The clinical characteristics and treatment for sudden sensorineural hearing loss with vestibular schwannoma.

    Science.gov (United States)

    Lin, Chang; Gong, Qilin; Zuo, Wenjing; Zhang, Rong; Zhou, Aidong

    2015-04-01

    The aim of this study is to analyze the clinical characteristics and treatment of sudden sensorineural hearing loss (SSNHL) patients with vestibular schwannoma (VS). The clinical features of the VS patients were explored by retrospectively analyzing the clinical data from 542 cases of SSNHL patients between January 2008 and March 2013. There were 10 cases (10 ears) diagnosed with VS in 542 cases of SSNHL patients (10 ears, 1.85 %), 3 males, 7 females, with a range of 28-57 years. Among all the cases, eight patients with abnormal ABR, ten with ear ipsilateral stapedius reflexes which were completely not elicited and seven patients with healthy ear contralateral stapedius reflexes which were completely not elicited. Neuromas were classified by Koos grades according to size (8 of grade I, 1 of grade II, 1 of grade IV). Eight small VS  patients were taken waiting and MRI therapy strategies. Meanwhile, we used glucocorticoid treatment and timely and short-term medication to improve the microcirculation of the inner ear for these patients. And four cases' hearing was improved. Some vestibular schwannomas have SSNHL as initial symptoms, especially the small ones in internal auditory canal. To prevent misdiagnosis or leak-diagnosis, MRI should be performed as a routine test for SSNHL, and ABR is sometimes necessary for SSNHL patients. It is also necessary to give appropriate treatment to protect hearing of the small vestibular schwannoma patients whose first symptoms are diagnosed as SSNHL in acute phase. PMID:24452772

  14. The role of GABAB receptors in the vestibular oculomotor system in mice.

    Science.gov (United States)

    Shimizu, Naoki; Wood, Scott; Kushiro, Keisuke; Perachio, Adrian; Makishima, Tomoko

    2016-04-01

    Systemic administration of a gamma-amino butyric acid type B (GABAB) receptor agonist, baclofen, affects various physiological and psychological processes. To date, the effects on oculomotor system have been well characterized in primates, however those in mice have not been explored. In this study, we investigated the effects of baclofen focusing on vestibular-related eye movements. Two rotational paradigms, i.e. sinusoidal rotation and counter rotation were employed to stimulate semicircular canals and otolith organs in the inner ear. Experimental conditions (dosage, routes and onset of recording) were determined based on the prior studies exploring the behavioral effects of baclofen in mice. With an increase in dosage, both canal and otolith induced ocular responses were gradually affected. There was a clear distinction in the drug sensitivity showing that eye movements derived from direct vestibulo-ocular reflex pathways were relatively unaltered, while the responses through higher-order neural networks in the vestibular system were substantially decreased. These findings were consistent with those observed in primates suggesting a well-conserved role of GABAB receptors in the oculomotor system across frontal-eyed and lateral-eyed animals. We showed here a previously unrecognized effect of baclofen on the vestibular oculomotor function in mice. When interpreting general animal performance under the drug, the potential contribution of altered balance system should be taken into consideration. PMID:26778789

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

    International Nuclear Information System (INIS)

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

  16. Adjusting of processes of microgemodynamics at sportsmen in the conditions of vestibular irritations

    Directory of Open Access Journals (Sweden)

    Syshko D.V.

    2012-12-01

    Full Text Available The comparative analysis of the functional being of the regulator systems of microgemodynamics is conducted in a skin at the sportswomen of specialized in the running types of track-and-field before and after vestibular irritations. 10 highly skilled athletes of specialized in at run on middle and long distances are explored. It is shown, that the vestibular irritation for certain causes the changes of processes of microgemodynamics in a skin, showing up not only in the change of size of perfusion but also spectrum of components of mechanisms of adjusting. It is got, that high-frequency respiratory and pulse vibrations at sportswomen occupied considerably a less stake in a general spectrum and were 9,8% and 8,3% accordingly, that specifies on an optimum influx outflow of peripheral blood. Structure of vibrations of skin blood stream after the vestibular irritations at sportswomen, consists of increase of deposit of respiratory component from 9,8% to 11,4%, that is conditioned by the change of dynamics of vein pressure at pulmonary mechanical activity, attracting action of «respiratory pump».

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

    Science.gov (United States)

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

    2013-01-01

    Previous investigations have correlated vestibular function to locomotion in vertebrates by scaling semicircular duct radius of curvature to body mass. However, this method fails to discriminate bipedal from quadrupedal non-avian dinosaurs. Because they exhibit a broad range of relative head sizes, we use dinosaurs to test the hypothesis that semicircular ducts scale more closely with head size. Comparing the area enclose