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Sample records for vestibular neuronitis

  1. 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.

  2. Otolith-Canal Convergence in Vestibular Nuclei Neurons

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    Dickman, J. David

    1996-01-01

    During manned spaceflight, acute vestibular disturbances often occur, leading to physical duress and a loss of performance. Vestibular adaptation to the weightless environment follows within two to three days yet the mechanisms responsible for the disturbance and subsequent adaptation are still unknown In order to understand vestibular system function in space and normal earth conditions the basic physiological mechanisms of vestibular information co coding must be determined. Information processing regarding head movement and head position with respect to gravity takes place in the vestibular nuclei neurons that receive signals From the semicircular canals and otolith organs in the vestibular labyrinth. These neurons must synthesize the information into a coded output signal that provides for the head and eye movement reflexes as well as the conscious perception of the body in three-dimensional space The current investigation will for the first time. determine how the vestibular nuclei neurons quantitatively synthesize afferent information from the different linear and angular acceleration receptors in the vestibular labyrinths into an integrated output signal. During the second year of funding, progress on the current project has been focused on the anatomical orientation of semicircular canals and the spatial orientation of the innervating afferent responses. This information is necessary in order to understand how vestibular nuclei neurons process the incoming afferent spatial signals particularly with the convergent otolith afferent signals that are also spatially distributed Since information from the vestibular nuclei is presented to different brain regions associated with differing reflexive and sensory functions it is important to understand the computational mechanisms used by vestibular neurons to produce the appropriate output signal.

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

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

    2008-01-01

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

  4. Responses of non-eye movement central vestibular neurons to sinusoidal horizontal translation in compensated macaques after unilateral labyrinthectomy

    OpenAIRE

    Newlands, Shawn D.; Lin, Nan; Wei, Min

    2014-01-01

    After vestibular labyrinth injury, behavioral deficits partially recover through the process of vestibular compensation. The present study was performed to improve our understanding of the physiology of the macaque vestibular system in the compensated state (>7 wk) after unilateral labyrinthectomy (UL). Three groups of vestibular nucleus neurons were included: pre-UL control neurons, neurons ipsilateral to the lesion, and neurons contralateral to the lesion. The firing responses of neurons se...

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

    OpenAIRE

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

    2011-01-01

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

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

    OpenAIRE

    Leijon, Sara; Magnusson, Anna K.

    2014-01-01

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

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

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

    2014-04-01

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

  8. 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.

  9. Binocular disparity tuning and visual-vestibular congruency of multisensory neurons in macaque parietal cortex

    OpenAIRE

    YANG, YUN; Liu, Sheng; Chowdhury, Syed A.; DEANGELIS, GREGORY C.; Angelaki, Dora E.

    2011-01-01

    Many neurons in the dorsal medial superior temporal (MSTd) and ventral intraparietal (VIP) areas of the macaque brain are multisensory, responding to both optic flow and vestibular cues to self-motion. The heading tuning of visual and vestibular responses can be either congruent or opposite, but only congruent cells have been implicated in cue integration for heading perception. Because of the geometric properties of motion parallax, however, both congruent and opposite cells could be involve...

  10. 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.

  11. 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.

  12. Molecular developmental neurobiology of formation, guidance and survival of primary vestibular neurons

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    Fritzsch, B.

    2003-10-01

    Untangling the molecular and physiological interactions that generate the proper connections of the primary vestibular neurons in normal gravity requires two parallel approaches. One approach needs to use mutant mice to delineate the molecular basis of developmental mechanisms that govern ear development, including formation and differentiation of neurons and establishment of their peripheral and central connections. Beyond that and in addition to it, we need physiological investigations using microgravity and/or hypergravity, as well as absence of otoconia, to understand the role played by vestibular stimuli to fine tune connections of primary and secondary vestibular neurons. This paper provides an overview of some of the molecular mechanisms uncovered over the last few years that guide development, differentiation and survival of primary vestibular neurons of the mammalian ear. Briefly, several genes that are essential for primary neuron formation have been identified, all genes that govern embryonic survival are known and the first genes and mechanisms that guide formation of proper connections are being revealed. While still incomplete, the progress has been astounding and the completion of the mouse genome project will further accelerate the pace. Such data pave the way to put the research on the influence of altered gravity stimulation within a molecular framework.

  13. Age related changes in neuron number in the mouse lateral vestibular nucleus.

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    Sturrock, R R

    1989-01-01

    The number of large neurons in the lateral vestibular nucleus of the mouse brain decreases in number after 25 months of age, from 488 at 25 months to 298 at 31 months. The number of small neurons in the nucleus remains constant up to 31 months of age. Large neurons accumulate lipofuscin from 25 months and their mean nuclear diameter increases significantly between 25 and 28 months of age. Small neurons contain very little lipofuscin even at 31 months of age and their mean nuclear diameter rem...

  14. Physiological characterization of vestibular efferent brainstem neurons using a transgenic mouse model.

    Science.gov (United States)

    Leijon, Sara; Magnusson, Anna K

    2014-01-01

    The functional role of efferent innervation of the vestibular end-organs in the inner ear remains elusive. This study provides the first physiological characterization of the cholinergic vestibular efferent (VE) neurons in the brainstem by utilizing a transgenic mouse model, expressing eGFP under a choline-acetyltransferase (ChAT)-locus spanning promoter in combination with targeted patch clamp recordings. The intrinsic electrical properties of the eGFP-positive VE neurons were compared to the properties of the lateral olivocochlear (LOC) brainstem neurons, which gives rise to efferent innervation of the cochlea. Both VE and the LOC neurons were marked by their negative resting membrane potential TEA insensitive outward currents with fast inactivation kinetics, indicating A-type potassium currents, in both the inner ear-projecting neuronal types. Immunohistochemistry confirmed expression of Kv4.3 and 4.2 ion channel subunits in both the VE and LOC neurons. The difference in spiking responses to depolarization is related to a two-fold impact of these transient outward currents on somatic integration in the LOC neurons compared to in VE neurons. It is speculated that the physiological properties of the VE neurons might be compatible with a wide-spread control over motion and gravity sensation in the inner ear, providing likewise feed-back amplification of abrupt and strong phasic signals from the semi-circular canals and of tonic signals from the gravito-sensitive macular organs. PMID:24867596

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

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

    2014-09-15

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

  16. Encoding of head acceleration in vestibular neurons. I. Spatiotemporal response properties to linear acceleration

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

    1993-01-01

    1. Extracellular recordings were made in and around the medial vestibular nuclei in decerebrated rats. Neurons were functionally identified according to their semicircular canal input on the basis of their responses to angular head rotations around the yaw, pitch, and roll head axes. Those cells responding to angular acceleration were classified as either horizontal semicircular canal-related (HC) or vertical semicircular canal-related (VC) neurons. The HC neurons were further characterized as either type I or type II, depending on the direction of rotation producing excitation. Cells that lacked a response to angular head acceleration, but exhibited sensitivity to a change in head position, were classified as purely otolith organ-related (OTO) neurons. All vestibular neurons were then tested for their response to sinusoidal linear translation in the horizontal head plane. 2. Convergence of macular and canal inputs onto central vestibular nuclei neurons occurred in 73% of the type I HC, 79% of the type II HC, and 86% of the VC neurons. Out of the 223 neurons identified as receiving macular input, 94 neurons were further studied, and their spatiotemporal response properties to sinusoidal stimulation with pure linear acceleration were quantified. Data were obtained from 33 type I HC, 22 type II HC, 22 VC, and 17 OTO neurons. 3. For each neuron the angle of the translational stimulus vector was varied by 15, 30, or 45 degrees increments in the horizontal head plane. In all tested neurons, a direction of maximum sensitivity was identified. An interesting difference among neurons was their response to translation along the direction perpendicular to that that produced the maximum response ("null" direction). For the majority of neurons tested, it was possible to evoke a nonzero response during stimulation along the null direction always had response phases that varied as a function of stimulus direction. 4. These spatiotemporal response properties were quantified in two independent ways. First, the data were evaluated on the basis of the traditional one-dimensional principle governed by the "cosine gain rule" and constant response phase at different stimulus orientations. Second, the response gain and phase values that were empirically determined for each orientation of the applied linear stimulus vector were fitted on the basis of a newly developed formalism that treats neuronal responses as exhibiting two-dimensional spatial sensitivity. Thus two response vectors were determined for each neuron on the basis of its response gain and phase at different stimulus directions in the horizontal head plane.(ABSTRACT TRUNCATED AT 400 WORDS).

  17. 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.

  18. Responses of non-eye movement central vestibular neurons to sinusoidal horizontal translation in compensated macaques after unilateral labyrinthectomy.

    Science.gov (United States)

    Newlands, Shawn D; Lin, Nan; Wei, Min

    2014-07-01

    After vestibular labyrinth injury, behavioral deficits partially recover through the process of vestibular compensation. The present study was performed to improve our understanding of the physiology of the macaque vestibular system in the compensated state (>7 wk) after unilateral labyrinthectomy (UL). Three groups of vestibular nucleus neurons were included: pre-UL control neurons, neurons ipsilateral to the lesion, and neurons contralateral to the lesion. The firing responses of neurons sensitive to linear acceleration in the horizontal plane were recorded during sinusoidal horizontal translation directed along six different orientations (30° apart) at 0.5 Hz and 0.2 g peak acceleration (196 cm/s(2)). This data defined the vector of best response for each neuron in the horizontal plane, along which sensitivity, symmetry, detection threshold, and variability of firing were determined. Additionally, the responses of the same cells to translation over a series of frequencies (0.25-5.0 Hz) either in the interaural or naso-occipital orientation were obtained to define the frequency response characteristics in each group. We found a decrease in sensitivity, increase in threshold, and alteration in orientation of best responses in the vestibular nuclei after UL. Additionally, the phase relationship of the best neural response to translational stimulation changed with UL. The symmetry of individual neuron responses in the excitatory and inhibitory directions was unchanged by UL. Bilateral central utricular neurons still demonstrated two-dimension tuning after UL, consistent with spatio-temporal convergence from a single vestibular end-organ. These neuronal data correlate with known behavioral deficits after unilateral vestibular compromise. PMID:24717349

  19. Postsynaptic mechanisms underlying the excitatory action of histamine on medial vestibular nucleus neurons in rats

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    Zhang, Xiao-Yang; Yu, Lei; Zhuang, Qian-Xing; Peng, Shi-Yu; Zhu, Jing-Ning; Wang, Jian-Jun

    2013-01-01

    Background and Purpose Anti-histaminergic drugs have been widely used in the clinical treatment of vestibular disorders and most studies concentrate on their presynaptic actions. The present study investigated the postsynaptic effect of histamine on medial vestibular nucleus (MVN) neurons and the underlying mechanisms. Experimental Approach Histamine-induced postsynaptic actions on MVN neurons and the corresponding receptor and ionic mechanisms were detected by whole-cell patch-clamp recordings on rat brain slices. The distribution of postsynaptic histamine H1, H2 and H4 receptors was mapped by double and single immunostaining. Furthermore, the expression of mRNAs for H1, H2 and H4 receptors and for subtypes of Na+–Ca2+ exchangers (NCXs) and hyperpolarization-activated cyclic nucleotide-gated (HCN) channels was assessed by quantitative real-time RT-PCR. Key Results A marked postsynaptic excitatory effect, co-mediated by histamine H1 and H2 receptors, was involved in the histamine-induced depolarization of MVN neurons. Postsynaptic H1 and H2 rather than H4 receptors were co-localized in the same MVN neurons. NCXs contributed to the inward current mediated by H1 receptors, whereas HCN channels were responsible for excitation induced by activation of H2 receptors. Moreover, NCX1 and NCX3 rather than NCX2, and HCN1 rather than HCN2-4 mRNAs, were abundantly expressed in MVN. Conclusion and Implications NCXs coupled to H1 receptors and HCN channels linked to H2 receptors co-mediate the strong postsynaptic excitatory action of histamine on MVN neurons. These results highlight an active role of postsynaptic mechanisms in the modulation by central histaminergic systems of vestibular functions and suggest potential targets for clinical treatment of vestibular disorders. Linked Articles This article is part of a themed issue on Histamine Pharmacology Update. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2013.170.issue-1 PMID:23713466

  20. 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.

  1. Direct muscarinic and nicotinic receptor-mediated excitation of rat medial vestibular nucleus neurons in vitro

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    Phelan, K. D.; Gallagher, J. P.

    1992-01-01

    We have utilized intracellular recording techniques to investigate the cholinoceptivity of rat medial vestibular nucleus (MVN) neurons in a submerged brain slice preparation. Exogenous application of the mixed cholinergic agonists, acetylcholine (ACh) or carbachol (CCh), produced predominantly membrane depolarization, induction of action potential firing, and decreased input resistance. Application of the selective muscarinic receptor agonist muscarine (MUSC), or the selective nicotinic receptor agonists nicotine (NIC) or 1,1-dimethyl-4-phenylpiperazinium (DMPP) also produced membrane depolarizations. The MUSC-induced depolarization was accompanied by decreased conductance, while an increase in conductance appeared to underlie the NIC- and DMPP-induced depolarizations. The muscarinic and nicotinic receptor mediated depolarizations persisted in tetrodotoxin and/or low Ca2+/high Mg2+ containing media, suggesting direct postsynaptic receptor activation. The MUSC-induced depolarization could be reversibly blocked by the selective muscarinic-receptor antagonist, atropine, while the DMPP-induced depolarization could be reversibly suppressed by the selective ganglionic nicotinic-receptor antagonist, mecamylamine. Some neurons exhibited a transient membrane hyperpolarization during the depolarizing response to CCh or MUSC application. This transient inhibition could be reversibly blocked by the gamma-aminobutyric acid (GABA) antagonist, bicuculline, suggesting that the underlying hyperpolarization results indirectly from the endogenous release of GABA acting at GABA receptors. This study confirms the cholinoceptivity of MVN neurons and establishes that individual MVN cells possess muscarinic as well as nicotinic receptors. The data provide support for a prominent role of cholinergic mechanisms in the direct and indirect regulation of the excitability of MVN neurons.

  2. Firing properties of GABAergic versus non-GABAergic vestibular nucleus neurons conferred by a differential balance of potassium currents.

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    Gittis, Aryn H; du Lac, Sascha

    2007-06-01

    Neural circuits are composed of diverse cell types, the firing properties of which reflect their intrinsic ionic currents. GABAergic and non-GABAergic neurons in the medial vestibular nuclei, identified in GIN and YFP-16 lines of transgenic mice, respectively, exhibit different firing properties in brain slices. The intrinsic ionic currents of these cell types were investigated in acutely dissociated neurons from 3- to 4-wk-old mice, where differences in spontaneous firing and action potential parameters observed in slice preparations are preserved. Both GIN and YFP-16 neurons express a combination of four major outward currents: Ca(2+)-dependent K(+) currents (I(KCa)), 1 mM TEA-sensitive delayed rectifier K(+) currents (I(1TEA)), 10 mM TEA-sensitive delayed rectifier K(+) currents (I(10TEA)), and A-type K(+) currents (I(A)). The balance of these currents varied across cells, with GIN neurons tending to express proportionately more I(KCa) and I(A), and YFP-16 neurons tending to express proportionately more I(1TEA) and I(10TEA). Correlations in charge densities suggested that several currents were coregulated. Variations in the kinetics and density of I(1TEA) could account for differences in repolarization rates observed both within and between cell types. These data indicate that diversity in the firing properties of GABAergic and non-GABAergic vestibular nucleus neurons arises from graded differences in the balance and kinetics of ionic currents. PMID:17392422

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

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    Kwok Jessica CF

    2012-02-01

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

  4. Response of pontomedullary reticulospinal neurons to vestibular stimuli in vertical planes. Role in vertical vestibulospinal reflexes of the decerebrate cat

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    Bolton, P. S.; Goto, T.; Schor, R. H.; Wilson, V. J.; Yamagata, Y.; Yates, B. J.

    1992-01-01

    1. To investigate the neural substrate of vestibulospinal reflexes in decerebrate cats, we studied the responses of pontomedullary reticulospinal neurons to natural stimulation of the labyrinth in vertical planes. Our principal aim was to determine whether reticulospinal neurons that terminate in, or are likely to give off collaterals to, the upper cervical segments had properties similar to those of the vestibulocollic reflex (VCR). 2. Antidromic stimulation was used to determine whether the neurons projected to the neck, lower cervical, thoracic, or lumbar levels. Dynamics of the responses of spontaneously firing neurons were studied with sinusoidal stimuli delivered at 0.05-1 Hz and aligned to the plane of body rotation, that produced maximal modulation of the neuron (response vector orientation). Each neuron was assigned a vestibular input classification of otolith, vertical canal, otolith + canal, or spatial-temporal convergence (STC). 3. We found, in agreement with previous studies, that the largest fraction of pontomedullary reticulospinal neurons projected to the lumbar cord, and that only a small number ended in the neck segments. Neurons projecting to all levels of the spinal cord had similar responses to labyrinth stimulation. 4. Reticulospinal neurons that received only vertical canal inputs were rare (1 of 67 units). Most reticulospinal neurons (48%) received predominant otolith inputs, 18% received otolith + canal input, and only 9% had STC behavior. These data are in sharp contrast to the results of our previous studies of vestibulospinal neurons. A considerable portion of vestibulospinal neurons receives vertical canal input (38%), fewer receive predominantly otolith input (22%), whereas the proportion that have otolith + canal input or STC behavior is similar to our present reticulospinal data. 5. The response vector orientations of our reticulospinal neurons, particularly those with canal inputs (canal, otolith + canal, STC) were predominantly in the roll quadrants. There was no evidence of convergence of inputs from like canals across the midline (e.g., right anterior + left anterior). 6. Two characteristics of the VCR, STC behavior and bilateral input from symmetric vertical canals (in some muscles), cannot be accounted for by the reticulospinal neurons that we studied. Because these characteristics are also not seen in vestibulocollic neurons, they are likely to be the result of the appropriate convergence of vestibular signals in the spinal cord. 7. Pontomedullary reticulospinal neurons seem particularly well suited to play a role in gravity-dependent postural reflexes of neck and limbs.

  5. Vestibular Hyperacusis

    Science.gov (United States)

    ... Diagnosis & Treatment Types of Vestibular Disorders Acoustic Neuroma/Vestibular Schwannoma Age-related dizziness and imbalance Autoimmune Inner Ear Disease (AIED) Benign Paroxysmal Positional Vertigo (BPPV) Bilateral Vestibular ... Syndrome Cervicogenic Dizziness Cholesteatoma Enlarged Vestibular ...

  6. 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.

  7. Implantes vestibulares / Vestibular prosthesis

    Scientific Electronic Library Online (English)

    Cristian, Aedo Sánchez; Paul H, Délano Reyes.

    2013-12-01

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

  8. 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 entit...

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

    OpenAIRE

    Wentzel, P.R.

    1998-01-01

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

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

    Directory of Open Access Journals (Sweden)

    KennaPeusner

    2012-02-01

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

  11. Pediatric Vestibular Disorders

    Science.gov (United States)

    ... Canal Dehiscence (SCD) Tinnitus Vestibular Hyperacusis Vision & Hearing Psychology Diet Other Topics Military Resources Paid Advertisement Meniere's ... this site. Pediatric Vestibular Disorders Vestibular Disorders affect children as well as adults The vestibular system is ...

  12. Labyrinthitis and Vestibular Neuritis

    Science.gov (United States)

    ... Diagnosis & Treatment Types of Vestibular Disorders Acoustic Neuroma/Vestibular Schwannoma Age-related dizziness and imbalance Autoimmune Inner Ear Disease (AIED) Benign Paroxysmal Positional Vertigo (BPPV) Bilateral Vestibular ... Syndrome Cervicogenic Dizziness Cholesteatoma Enlarged Vestibular ...

  13. Development of a biophysical model for vestibular prosthesis research.

    Science.gov (United States)

    Rubinstein, J T; Della Santina, C C

    Physiologic properties of primary vestibular neurons are compared and contrasted with properties of primary auditory neurons. The differences and similarities suggest possible coding strategies for a vestibular implant. The degree of spike rate variability, or coefficient of variation (CV), is a prominent physiological property of vestibular neurons with undetermined functional significance. At the very least, CV is highly correlated with threshold to electrical stimulation in the intact vestibular labyrinth. If CV is also important for vestibular coding, then electrical stimulation strategies should be designed to restore relatively physiologic patterns of CV. Simulations using a stochastic model of primary afferent vestibular neurons reveal that this should be possible using combinations of low and high-rate pulsatile stimulation. They also demonstrate that differences in the number and independence of synaptic inputs can significantly affect CV. PMID:12867665

  14. Spatiotemporal Properties of Vestibular Responses in Area MSTd

    OpenAIRE

    Fetsch, Christopher R.; Rajguru, Suhrud M; Karunaratne, Anuk; Gu, Yong; Angelaki, Dora E.; DEANGELIS, GREGORY C.

    2010-01-01

    Recent studies have shown that many neurons in the primate dorsal medial superior temporal area (MSTd) show spatial tuning during inertial motion and that these responses are vestibular in origin. Given their well-studied role in processing visual self-motion cues (i.e., optic flow), these neurons may be involved in the integration of visual and vestibular signals to facilitate robust perception of self-motion. However, the temporal structure of vestibular responses in MSTd has not been chara...

  15. [Effect of low-frequency vibration on the activity of dehydrogenase in neurones of anterior vestibular nucleus in rats].

    Science.gov (United States)

    Nasibullin, B A; Rozanov, V A; Ianovsky?, M B

    1993-01-01

    To obtain the characteristics of the main changes in oxidative metabolism in the neurons of the nucleus vestibularis anterior (NVA) under the influence of low frequency vibration in rat brain the activities of some dehydrogenases (NADN-DH, NADPH-DH, succinate-DH, malate-DH, beta-oxybutyrate-DH, alpha-glycerolphosphate-DH, lactate-DH, glutamate-DH and 6-phosphogluconate-DH) were measured using histochemical methods. The sizes of subpopulations of neurons differing in enzyme activities were estimated. PMID:8335122

  16. Non-linear Galilean vestibular receptive fields.

    Science.gov (United States)

    Bennequin, D; Berthoz, A

    2011-01-01

    We present a set of formulas for the receptive fields of the vestibular neurons that are motivated by Galilean invariance. We show that these formulas explain non-trivial data in neurophysiology, and suggest new hypothesis to be tested in dynamical 3D conditions. Moreover our model offers a way for neuronal computing with 3D displacements, which is reputed to be hard, underlying the vestibular reflexes. This computation is presented in a Bayesian framework. The basis of the model is the necessity of living bodies to work invariantly in space-time, allied to the necessary discreteness of neuronal transmission. PMID:22254794

  17. Visuo-vestibular biofeedback in patients with peripheral vestibular disorders.

    Science.gov (United States)

    Hahn, A; Sejna, I; Stolbova, K; Cocek, A

    2001-01-01

    It is well known that diseases of the vestibular system can be compensated by increased spontaneous activity of other systems engaged in maintaining equilibrium, i.e. proprioceptive and visual systems. A complex approach using multisensory stimulation is the optimal way to achieve vestibular compensation. The aim of our study was to determine the effect of vestibular rehabilitation therapy as measured by posturography in a group of 72 patients suffering from vestibular disorders: Ménière's disease (n = 31), neuritis vestibularis (n = 21) and vertebrobasilar insufficiency (n = 20). Patients underwent the following examinations: electronystagmography; caloric, rotatory and optokinetic tests; computed posturography; craniocorpography; pure-tone audiometry; speech audiometry; and tinnitometry (tinnitus loudness, pitch). The instability in patients with Ménière's disease decreased 3 weeks after starting the therapy; nevertheless, the decrease in area (the surface formed by the movement of the patient's equilibrium point during a defined time) was transitory because of the increase in area values obtained between the 3rd and 6th weeks when measured with closed eyes. In the vestibular neuronitis patients, the measured values of area and the velocity of the patient's movement decreased continuously. The values measured in the patients suffering from vertebrobasilar insufficiency decreased continuously, the absolute values remaining pathological. PMID:11677751

  18. Towards a neuromorphic vestibular system.

    Science.gov (United States)

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

    2014-10-01

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

  19. 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.

  20. Rehabilitation in vestibular system diseases

    Directory of Open Access Journals (Sweden)

    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.

  1. Procedures for restoring vestibular disorders

    Directory of Open Access Journals (Sweden)

    Walther, Leif Erik

    2005-09-01

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

  2. Vestibular migraine : Diagnostic criteria

    DEFF Research Database (Denmark)

    Lempert, Thomas; Olesen, Jes

    2012-01-01

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

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

    Science.gov (United States)

    Lacour, Michel; Bernard-Demanze, Laurence

    2015-01-01

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

  4. Connections between the cerebellar nucleus interpositus and the vestibular nuclei: an anatomical study in the rat.

    Science.gov (United States)

    Compoint, C; Buisseret-Delmas, C; Diagne, M; Buissseret, P; Angaut, P

    1997-12-01

    Interposito-vestibular connections were analysed, using the anterograde and retrograde tracer biotinylated dextran amine. The interposito-vestibular projections mainly arise from medial portions of the cerebellar nuclei interpositi anterior (NIA) and posterior (NIP), and reach each of the main vestibular nuclei, ipsilaterally. The highest density of projections is found throughout nucleus vestibularis lateralis. Fibres also reach the peripheral part of nucleus superior, the caudal part of nucleus inferior, and the lateral part of nucleus medialis. Some fibres also reach groups I, x and f. Contralaterally, few fibres reach zones of the vestibular nuclei symmetric to the ipsilateral projection. A small, reciprocal, vestibulo-interposed projection is sent from the vestibular nuclei onto NIA-NIP. Possible influences of the interposito-vestibular projections upon the major targets of the vestibular nuclei, spinal motoneurones and oculomotor neurones, are discussed. PMID:9464627

  5. 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.

  6. 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.

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

    Scientific Electronic Library Online (English)

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

    2014-09-01

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

  8. Vestibular Schwannoma (Acoustic Neuroma) and Neurofibromatosis

    Science.gov (United States)

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

  9. Auditory and vestibular efferents

    CERN Document Server

    Ryugo, David K; Popper, Arthur

    2010-01-01

    This book focuses on auditory and vestibular efferents, topics linked together by the inner ear connection. Top researchers in the field review the history of the subject and summarize what is known and what still needs to be done.

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

    Directory of Open Access Journals (Sweden)

    M. V. Zamergrad

    2014-10-01

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

  12. New Insights into Pathophysiology of Vestibular Migraine

    Science.gov (United States)

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

    2015-01-01

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

  13. Vestibular modulation of spatial perception

    OpenAIRE

    ElisaRaffaellaFerre; MatthewLongo; FedericoFiori

    2013-01-01

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

  14. Vestibular modulation of spatial perception

    OpenAIRE

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

    2013-01-01

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

  15. Spatiotemporal properties of vestibular responses in area MSTd.

    Science.gov (United States)

    Fetsch, Christopher R; Rajguru, Suhrud M; Karunaratne, Anuk; Gu, Yong; Angelaki, Dora E; Deangelis, Gregory C

    2010-09-01

    Recent studies have shown that many neurons in the primate dorsal medial superior temporal area (MSTd) show spatial tuning during inertial motion and that these responses are vestibular in origin. Given their well-studied role in processing visual self-motion cues (i.e., optic flow), these neurons may be involved in the integration of visual and vestibular signals to facilitate robust perception of self-motion. However, the temporal structure of vestibular responses in MSTd has not been characterized in detail. Specifically, it is not known whether MSTd neurons encode velocity, acceleration, or some combination of motion parameters not explicitly encoded by vestibular afferents. In this study, we have applied a frequency-domain analysis to single-unit responses during translation in three dimensions (3D). The analysis quantifies the stimulus-driven temporal modulation of each response as well as the degree to which this modulation reflects the velocity and/or acceleration profile of the stimulus. We show that MSTd neurons signal a combination of velocity and acceleration components with the velocity component being stronger for most neurons. These two components can exist both within and across motion directions, although their spatial tuning did not show a systematic relationship across the population. From these results, vestibular responses in MSTd appear to show characteristic features of spatiotemporal convergence, similar to previous findings in the brain stem and thalamus. The predominance of velocity encoding in this region may reflect the suitability of these signals to be integrated with visual signals regarding self-motion perception. PMID:20631212

  16. Vestibular Deficits Following Concussion

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2015-05-01

    Full Text Available Investigators from the Division of Emergency Medicine, Sports Medicine, and Department of Pediatrics, Children’s Hospital of Philadelphia, PA, and Sports Medicine, Somerset, NJ, performed a retrospective cohort study of 247 patients ages 5-18 years with concussion referred from July 2010 to Dec 2011; 81% of patients showed a vestibular abnormality on initial clinical examination.

  17. 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.

  18. 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.

  19. Atypical Manifestation of Vestibular Schwannoma

    OpenAIRE

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

    2013-01-01

    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.

  20. 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 ...

  1. 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 to selectively manipulate and measure vestibular processing and perspectival structure. The hope is that this serves to indicate how interdisciplinary research on vestibular processing might advance our...

  2. Convergence of Vestibular and Neck Proprioceptive Sensory Signals in the Cerebellar Interpositus

    OpenAIRE

    Luan, Hongge; Gdowski, Martha Johnson; Newlands, Shawn D.; Gdowski, Greg T.

    2013-01-01

    The cerebellar interpositus nucleus (IN) contributes to controlling voluntary limb movements. We hypothesized that the vestibular signals within the IN might be transformed into coordinates describing the body’s movement, appropriate for controlling limb movement. We tested this hypothesis by recording from IN neurons in alert squirrel monkeys during vestibular and proprioceptive stimulation produced during (1) yaw head-on-trunk rotation about the C1–C2 axis while in an orthograde posture and...

  3. 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 targets the angiogenic process by investigation of tumor expression of MMP-2, MMP-9, and tissue inhibitors of metalloproteinase (TIMP)-1. A possible correlation with gender, patient age, symptom duration,...

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

    OpenAIRE

    JudithWagner; BerndtWowra; RolandGoldbrunner; ChristianCnyrim; Jörg-ChristianTonn

    2011-01-01

    Objectives. Patients with vestibular schwannoma (VS) frequently suffer from disabling vestibular symptoms. This prospective follow-up study evaluates vestibular and auditory function and impairment of quality of life due to vertigo, dizziness and imbalance in patients with unilateral vestibular schwannoma of different sizes before/ after microsurgical or radiosurgical treatment. Methods. 38 patients with unilateral vestibular schwannoma were included. 22 received microsurgery, 16 cyberkni...

  5. 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.

  6. 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.

  7. 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.

  8. Surgery of vestibular schwannomas

    Directory of Open Access Journals (Sweden)

    Madjid Samii

    2012-01-01

    Full Text Available Vestibular schwannomas (VS are the most common tumors of the cerebellopontine angle (CPA. Their surgical management has reached high standards in the last decade. Treatment options for VS are microsurgical removal or Radiosurgery. The following three basic operative approaches are currently utilized: Retrosigmoid approach (RSA, translabyrinthine and middle fossa approach. The following article elaborates the operative technique by the senior author based on his vast experience of VS surgery formed over the last three decades; during which period he has operated more than 3500 of such patients.

  9. 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.; Díaz, C.; Alvarez, J C; González del Rey, C.; Tolivia, J.

    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...

  10. A general framework for neurobiological modeling: an application to the vestibular system.

    Science.gov (United States)

    Eliasmith, Chris; Westover, M B; Anderson, C H

    2002-06-01

    The otolith organs in the vestibular system are excellent detectors of linear accelerations. However, any measurement of linear acceleration is ambiguous between a tilt in a gravitational field and an inertial acceleration. Angelaki et al. have put forward a general hypothesis about how inertial accelerations can be computed based on vestibular signals (J. Neurosci. 19 (1999) 316). We have constructed a realistic, detailed model of the relevant systems to test this hypothesis. The model produces useful predictions about what kinds of neurons should be found in the vestibular nucleus if such a computation is actually performed in the vestibular system. The model is constructed using general principles of neurobiological simulation (J. Neurophys. 84 (2000) 2113). PMID:12744262

  11. Medial vestibular connections with the hypocretin (orexin) system

    Science.gov (United States)

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

    2005-01-01

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

  12. Enlarged Vestibular Aqueduct Syndrome (EVAS)

    Science.gov (United States)

    ... an enlarged endolymphatic duct and sac on high-resolution MRI. Thyroid, renal, and cardiac function may also ... Support: Enlarged Vestibular Aqueduct Syndrome (EVAS) http://www.pro.oticonusa.com/~asset/cache.ashx?id=22035&type= ...

  13. Postural Compensation for Vestibular Loss

    OpenAIRE

    Horak, Fay B

    2010-01-01

    To what extent can remaining sensory information and/or sensory biofeedback compensate for loss of vestibular information in controlling postural equilibrium? The primary role of the vestibulospinal system is as a vertical reference for control of the trunk in space, with increasing importance as the surface becomes increasingly unstable. Our studies with patients with bilateral loss of vestibular function show that vision or light touch from a fingertip can substitute as a reference for eart...

  14. Atypical Manifestation of Vestibular Schwannoma

    Scientific Electronic Library Online (English)

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

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

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

    Science.gov (United States)

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

    2015-01-01

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

  17. Role of the medial medullary reticular formation in relaying vestibular signals to the diaphragm and abdominal muscles

    Science.gov (United States)

    Mori, R. L.; Bergsman, A. E.; Holmes, M. J.; Yates, B. J.

    2001-01-01

    Changes in posture can affect the resting length of respiratory muscles, requiring alterations in the activity of these muscles if ventilation is to be unaffected. Recent studies have shown that the vestibular system contributes to altering respiratory muscle activity during movement and changes in posture. Furthermore, anatomical studies have demonstrated that many bulbospinal neurons in the medial medullary reticular formation (MRF) provide inputs to phrenic and abdominal motoneurons; because this region of the reticular formation receives substantial vestibular and other movement-related input, it seems likely that medial medullary reticulospinal neurons could adjust the activity of respiratory motoneurons during postural alterations. The objective of the present study was to determine whether functional lesions of the MRF affect inspiratory and expiratory muscle responses to activation of the vestibular system. Lidocaine or muscimol injections into the MRF produced a large increase in diaphragm and abdominal muscle responses to vestibular stimulation. These vestibulo-respiratory responses were eliminated following subsequent chemical blockade of descending pathways in the lateral medulla. However, inactivation of pathways coursing through the lateral medulla eliminated excitatory, but not inhibitory, components of vestibulo-respiratory responses. The simplest explanation for these data is that MRF neurons that receive input from the vestibular nuclei make inhibitory connections with diaphragm and abdominal motoneurons, whereas a pathway that courses laterally in the caudal medulla provides excitatory vestibular inputs to these motoneurons.

  18. Hearing Improvement in a Growing Vestibular Schwannoma

    OpenAIRE

    Del Pero, Marcos Martinez; Lloyd, Simon K.W.; Moffat, David A.

    2009-01-01

    Vestibular schwannomas are benign, slow-growing tumors that originate from Schwann cells lining the vestibular nerves, most commonly the superior vestibular nerve. They arise at the neurilemmal/neuroglial junction which is situated within the internal auditory canal. They have an incidence of 1 per 100,000 per year and a prevalence of around 700 per million. A case of a patient undergoing a period of observation for a vestibular schwannoma whose hearing improved despite growth of the tumor is...

  19. 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.

  20. Dual task interference during gait in patients with unilateral vestibular disorders

    Directory of Open Access Journals (Sweden)

    Nascimbeni Alberto

    2010-09-01

    Full Text Available Abstract Background Vestibular patients show slower and unsteady gait; they have also been shown to need greater cognitive resources when carrying out balance and cognitive dual tasks (DT. This study investigated DT interference during gait in a middle-aged group of subjects with dizziness and unsteadiness after unilateral vestibular neuronitis and in a healthy control group. Methods Fourteen individuals with subacute unilateral vestibular impairment after neuronitis and seventeen healthy subjects performed gait and cognitive tasks in single and DT conditions. A statistical gait analysis system was used and spatio-temporal parameters were considered. The cognitive task, consisting of backward counting by three, was tape recorded and the number of right figures was then calculated. Results Both patients and controls showed a more conservative gait during DT and between groups significant differences were not found. A significant decrease in cognitive performance during DT was found only in the vestibular group. Conclusions Results suggest that less attentional resources are available during gait in vestibular patients compared to controls, and that a priority is given in keeping up the motor task to the detriment of a decrease of the cognitive performance during DT.

  1. 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.

  2. Negative emotional stimuli enhance vestibular processing.

    Science.gov (United States)

    Preuss, Nora; Ellis, Andrew W; Mast, Fred W

    2015-08-01

    Recent studies have shown that vestibular stimulation can influence affective processes. In the present study, we examined whether emotional information can also modulate vestibular perception. Participants performed a vestibular discrimination task on a motion platform while viewing emotional pictures. Six different picture categories were taken from the International Affective Picture System: mutilation, threat, snakes, neutral objects, sports, and erotic pictures. Using a Bayesian hierarchical approach, we were able to show that vestibular discrimination improved when participants viewed emotionally negative pictures (mutilation, threat, snake) when compared to neutral/positive objects. We conclude that some of the mechanisms involved in the processing of vestibular information are also sensitive to emotional content. Emotional information signals importance and mobilizes the body for action. In case of danger, a successful motor response requires precise vestibular processing. Therefore, negative emotional information improves processing of vestibular information. PMID:26098730

  3. Early vestibular processing does not discriminate active from passive self-motion if there is a discrepancy between predicted and actual proprioceptive feedback.

    Science.gov (United States)

    Brooks, Jessica X; Cullen, Kathleen E

    2014-06-15

    Most of our sensory experiences are gained by active exploration of the world. While the ability to distinguish sensory inputs resulting of our own actions (termed reafference) from those produced externally (termed exafference) is well established, the neural mechanisms underlying this distinction are not fully understood. We have previously proposed that vestibular signals arising from self-generated movements are inhibited by a mechanism that compares the internal prediction of the proprioceptive consequences of self-motion to the actual feedback. Here we directly tested this proposal by recording from single neurons in monkey during vestibular stimulation that was externally produced and/or self-generated. We show for the first time that vestibular reafference is equivalently canceled for self-generated sensory stimulation produced by activation of the neck musculature (head-on-body motion), or axial musculature (combined head and body motion), when there is no discrepancy between the predicted and actual proprioceptive consequences of self-motion. However, if a discrepancy does exist, central vestibular neurons no longer preferentially encode vestibular exafference. Specifically, when simultaneous active and passive motion resulted in activation of the same muscle proprioceptors, neurons robustly encoded the total vestibular input (i.e., responses to vestibular reafference and exafference were equally strong), rather than exafference alone. Taken together, our results show that the cancellation of vestibular reafference in early vestibular processing requires an explicit match between expected and actual proprioceptive feedback. We propose that this vital neuronal computation, necessary for both accurate sensory perception and motor control, has important implications for a variety of sensory systems that suppress self-generated signals. PMID:24671531

  4. Vestibular schwannoma with contralateral facial pain – case report

    OpenAIRE

    Ghodsi Mohammad; Gheini Mohammadreza; Eftekhar Behzad; Ketabchi Ebrahim

    2003-01-01

    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...

  5. Vestibular toxicity of cis-2-pentenenitrile in the rat

    OpenAIRE

    Saldaña Ruiz, Sandra; Hernández-Mir, Gerard; Sedó Cabezón, Lara; Cutillas Arroyo, Blanca; Llorens i Baucells, Jordi

    2012-01-01

    cis-2-Pentenenitrile, an intermediate in the synthesis of nylon and other products, causes permanent behavioral deficits in rodents. Other low molecular weight nitriles cause degeneration either of the vestibular sensory hair cells or of selected neuronal populations in the brain. Adult male Long-Evans rats were exposed to cis-2-pentenenitrile (0, 1.25, 1.50, 1.75, or 2.0 mmol/kg, oral, in corn oil) and assessed for changes in open field activity and rating scores in a test battery for vestib...

  6. 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.

  7. Stereotactic radiotherapy for vestibular schwannoma

    DEFF Research Database (Denmark)

    Muzevic, Dario; Legcevic, Jelena

    2014-01-01

    BACKGROUND: Vestibular schwannomas (acoustic neuromas) are common benign tumours that arise from the Schwann cells of the vestibular nerve. Management options include observation with neuroradiological follow-up, microsurgical resection and stereotactic radiotherapy. OBJECTIVES: To assess the effect of stereotactic radiotherapy compared to observation, microsurgical resection, any other treatment modality, or a combination of two or more of the above approaches for vestibular schwannoma. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials; PubMed; EMBASE; CINAHL; Web of Science; CAB Abstracts; ISRCTN and additional sources for published and unpublished trials. The date of the search was 24 July 2014. SELECTION CRITERIA: Randomised controlled trials (RCTs) exploring the efficacy of stereotactic radiotherapy compared with observation alone, microsurgical resection or any other possible treatment or combination of treatments in patients with a cerebellopontine angle tumour up to 3 cm in diameter, presumed to be a vestibular schwannoma. DATA COLLECTION AND ANALYSIS: We used the standard methodological procedures expected by The Cochrane Collaboration. MAIN RESULTS: No studies met the inclusion criteria for this review. AUTHORS' CONCLUSIONS: There is no high quality evidence in the literature from RCTs to determine whether stereotactic radiotherapy is better than microsurgical resection or observation alone for patients with a vestibular schwannoma. In the absence of such evidence, the treatment method should be chosen on an individual basis, taking into consideration the patient's preferences, clinician experience and the availability of radiotherapeutic equipment. With the growing availability of radiotherapeutic equipment, randomised controlled trials should be undertaken to evaluate the role of stereotactic radiotherapy in comparison with other treatment options.

  8. Vestibular Findings in Military Band Musicians

    Directory of Open Access Journals (Sweden)

    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.

  9. Vestibular Findings in Military Band Musicians

    Scientific Electronic Library Online (English)

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

    2014-04-01

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

  10. Vestibular findings in military band musicians.

    Science.gov (United States)

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

    2014-04-01

    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. PMID:25992076

  11. Effect of unilateral labyrinthectomy on the molecular composition of perineuronal nets in the lateral vestibular nucleus of the rat.

    Science.gov (United States)

    Deák, Ádám; Bácskai, Tímea; Gaál, Botond; Rácz, Éva; Matesz, Klara

    2012-03-28

    Disturbances in vestibular functions caused by unilateral labyrinthectomy (UL) are spontaneously restored during the process of vestibular compensation due to the plasticity of CNS. The underlying molecular background of vestibular compensation is not yet fully understood. Recent studies have shown that the extracellular matrix (ECM) molecules have either permissive or non-permissive effect on the neural plasticity. In our previous study we have demonstrated changes in the expression of hyaluronan (HA) in the vestibular nuclei (VN) of the frog following peripheral vestibular lesion. The present work was undertaken to examine the expression of the HA and chondroitin sulfate proteoglycans (CSPGs) in the lateral vestibular nucleus (LVN) of the rat following UL by using histochemical methods. On the first postoperative day, the condensation of the ECM around the neurons, the perineuronal net (PNN) was not distinguished from the surrounding neuropil on the side of UL indicating the desorganization of its molecular structure. At survival day 3, the PNN was recognizable with the HA probe, whereas its staining for the CSPGs was restored by the time of the seventh postoperative day. In the neuropil, the intensity of the HA increased on the operated side, while the CSPGs reaction almost completely disappeared. The present study have demonstrated for the first time that the UL is accompanied by the modification of the HA, and CSPG staining pattern in the PNN of the LVN in the rat. As the reorganization of the PNN corresponds to the restoration of spontaneous activity of vestibular neurons, our study implies the role of HA and CSPGs in the vestibular compensation. PMID:22342907

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

    OpenAIRE

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

    2012-01-01

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

  13. Functional expression of TRPV1 and TRPA1 in rat vestibular ganglia.

    Science.gov (United States)

    Kamakura, Takefumi; Ishida, Yusuke; Nakamura, Yukiko; Yamada, Takahiro; Kitahara, Tadashi; Takimoto, Yasumitsu; Horii, Arata; Uno, Atsuhiko; Imai, Takao; Okazaki, Suzuyo; Inohara, Hidenori; Shimada, Shoichi

    2013-09-27

    Both TRPV1 and TRPA1 are non-selective cation channels. They are co-expressed, and interact in sensory neurons such as dorsal root ganglia (DRG) and trigeminal ganglia (TG), and are involved in nociception, being activated by nociceptive stimuli. Immunohistological localization of TRPV1 in vestibular ganglion (VG) neurons has been reported. Although TRPA1 is co-expressed with TRPV1 in DRG and TG neurons, it is unclear whether TRPA1 channels are expressed in VG neurons. Moreover, it is unknown whether TRPV1 and TRPA1 channels are functional in VG neurons. We investigated the expression of TRPV1 and TRPA1 in rat VG neurons by RT-PCR, in situ hybridization, immunohistochemistry, and Ca(2+) imaging experiments. Both TRPV1 and TRPA1 RT-PCR products were amplified from the mRNA of rat VG neurons. In situ hybridization experiments showed TRPV1 and TRPA1 mRNA expression in the majority of VG neurons. Immunohistochemistry experiments confirmed TRPV1 protein expression. In Ca(2+) imaging experiments, capsaicin, a TRPV1 agonist, induced a significant increase in intracellular calcium ion concentration ([Ca(2+)]i) in rat primary cultured VG neurons, which was almost completely blocked by capsazepine, a TRPV1-specific antagonist. Cinnamaldehyde, a TRPA1 agonist, also caused an increase in [Ca(2+)]i, which was completely inhibited by HC030031, a TRPA1-specific antagonist. Moreover, in some VG neurons, a [Ca(2+)]i increase was evoked by both capsaicin and cinnamaldehyde in the same neuron. In summary, our histological and physiological studies reveal that TRPV1 and TRPA1 are expressed in VG neurons. It is suggested that TRPV1 and TRPA1 in VG neurons might participate in vestibular function and/or dysfunction such as vertigo. PMID:23916509

  14. Evaluation of tests for vestibular function

    Science.gov (United States)

    1992-01-01

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

  15. Vestibular schwannoma treatment : patients’ perceptions and outcomes

    OpenAIRE

    Godefroy, Willem Paul

    2010-01-01

    Vestibular schwannomas are benign intracranial tumors which generally arise from the Schwann cells of the superior part of the vestibular portion of the eight cranial nerve. The most common symptoms accompanying vestibular schwannoma (VS) are unilateral hearing loss, tinnitus, vertigo and unsteadiness. For many years, microsurgical treatment of VS has been considered the ‘gold standard’. However, the treatment of VS continues to evolve with the advent of alternative treatment ...

  16. Visual dependency and dizziness after vestibular neuritis

    OpenAIRE

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

    2014-01-01

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

  17. Complications of Microsurgery of Vestibular Schwannoma

    OpenAIRE

    Jan Betka; Eduard Zv??ina; Zuzana Balogová; Oliver Profant; Ji?í Sk?ivan; Josef Kraus; Ji?í Lisý; Josef Syka; Martin Chovanec

    2014-01-01

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

  18. A stochastic afterhyperpolarization model of repetitive activity in vestibular afferents.

    Science.gov (United States)

    Smith, C E; Goldberg, J M

    1986-01-01

    A stochastic version of Kernell's (1968, 1972) model with cumulative afterhyperpolarization (AHP) was simulated. A characteristic of the model is that the AHP is the result of an increased potassium conductance (g K) that is time-dependent but not voltage-dependent. Quantal synaptic inputs are assumed to be the only source of interspike interval variability. The model reproduces many features of the steady-state discharge of peripheral vestibular afferents, provided that firing rates are higher than 40 spikes/s. Among the results accounted for are the interspike interval statistics occurring during natural stimulation, their alteration by externally applied galvanic currents and the increase in the interspike interval following an interposed shock. Empirical studies show that some vestibular afferents have a regular spacing of action potentials, others an irregular spacing (Goldberg and Fernández 1971b; Fernández and Goldberg 1976). Irregularly discharging afferents have a higher sensitivity to externally applied galvanic currents than do regular afferents (Goldberg et al. 1984). To explain the relation between galvanic sensitivity and discharge regularity requires the assumption that neurons differ in both their synaptic noise (sigma v) and the slopes of their postspike voltage trajectories (d mu v/dt). The more irregular the neuron's discharge at a given firing frequency, the greater is sigma v and the smaller is d mu v/dt. Of the two factors, d mu v/dt is estimated to be four times more influential in determining discharge regularity across the afferent population. The shortcomings of the model are considered, as are possible remedies. Our conclusions are compared to previous discussions of mechanisms responsible for differences in the discharge regularity of vestibular afferents. PMID:3487348

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

    Science.gov (United States)

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

    2002-01-01

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

  20. Advances in Auditory and Vestibular Medicine

    OpenAIRE

    Hamid, Mohamed A.; Trune, Dennis R; Dutia, Mayank B

    2009-01-01

    Auditory and Vestibular medicine is becoming more accepted as a specialty of its own, Medical NeurOtology. Recent advances in the field have been instrumental in the understanding of the scientific foundations, pathophysiology, clinical approach and management of patients with hearing and vestibular disorders. This paper will review these advances.

  1. Epidemiology and natural history of vestibular schwannomas

    DEFF Research Database (Denmark)

    Stangerup, Sven-Eric; Caye-Thomasen, Per

    2012-01-01

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

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

    Science.gov (United States)

    Cohen, B.

    1981-01-01

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

  3. 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.

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

    Directory of Open Access Journals (Sweden)

    Fabiane Paulin

    2009-01-01

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

  5. Vestibular evoked myogenic potential responses in obstructive sleep apnea syndrome.

    Science.gov (United States)

    Mutlu, Murad; Bay?r, Ömer; Yüceege, Melike B; Karagöz, Tu?ba; F?rat, Hikmet; Özdek, Ali; Ak?n, ?stemihan; Korkmaz, Hakan

    2015-11-01

    Obstructive sleep apnea syndrome (OSAS) provokes oxidative stress and ischemia, which affects the central nervous system. The degeneration of neurons in the brainstem due to periodic hypoxia can be evaluated by vestibular and audiologic tests. The objective of this study is to determine brainstem damage in severe OSAS patients with the help of vestibular evoked myogenic potential (VEMP) responses. Prospective, randomize, double-blind. Research-training hospital. We compared cervical vestibular evoked myogenic potential (cVEMP) responses between severe OSAS patients and a control group. 54 patients were included and divided into the OSAS group, with severe OSAS (apnea-hypopnea index, AHI >70), and a control group with snoring without OSAS (AHI <5). Both groups underwent cVEMP. Bilateral recordings with simultaneous binaural logon stimulations were used during VEMP recordings. The existing p1n1 and n2p2 responses, p1, n1, n2, and p2 latencies and amplitudes, and p1n1 and n2p2 intervals were measured. Statistically significant differences were revealed between patients and controls for the response rate of the p1n1, n2p2 and p1n1, n2p2 amplitudes. There were no significant differences between the two groups with respect to the latencies of p1, n1, n2 and p2, or the p1n1 and n2p2 intervals. The VEMP response rate was lower in severe OSAS patients, and all amplitudes were shorter than in healthy subjects. VEMP recordings in severe OSAS subjects demonstrates abnormalities in brainstem pathways. It appears that brainstem damage in severe OSAS can be detected by cVEMP recordings. PMID:25288372

  6. Taste dysfunction in vestibular schwannomas

    Directory of Open Access Journals (Sweden)

    Sahu Rabi

    2008-01-01

    Full Text Available Background: Gustatory dysfunction associated with vestibular schwannomas (VS is a poorly represented clinical presentation. Materials and Methods: One hundred and forty-nine cases operated from 1997 to 2005 where at least six-month follow-up was available were included. All patients were tested for taste sensations using four modalities of standard taste solutions. Apart from the taste sensations, any altered or abnormal taste perceptions were recorded both in the preoperative and postoperative period. Results: After applying the exclusion criteria, the taste dysfunction was studied in 142 patients. The evidence of decreased taste sensation was found in 58 (40.8% patients prior to surgery. Preoperatively, taste disturbance was found in 29 (37.2% giant, 28 (45.9% large and one (33.3% medium-sized tumors, respectively. There were no significant age or sex-related differences. The postoperative taste disturbances were found in 65 (45.8% patients. Among patients with anatomically preserved facial nerve, postoperative taste disturbances were found in 55 (42.3% patients whereas nine (6.9% patients reported improvement in taste sensations. Conclusions: Taste dysfunction is common following vestibular schwannoma surgery. Patient counseling prior to surgery is necessary to avoid any distress caused by taste dysfunction. Taste dysfunction should be included in the facial nerve functional grading system while assessing outcome.

  7. Vestibular Function and Quality of Life in Vestibular Schwannoma: Does Size Matter?

    OpenAIRE

    Wagner, Judith Nastjenka; Glaser, Miriam; Wowra, Berndt; Muacevic, Alexander; Goldbrunner, Roland; Cnyrim, Christian; Tonn, Jörg-Christian; Strupp, Michael

    2011-01-01

    Objectives: Patients with vestibular schwannoma (VS) frequently suffer from disabling vestibular symptoms. This prospective follow-up study evaluates vestibular and auditory function and impairment of quality of life due to vertigo, dizziness, and imbalance in patients with unilateral VS of different sizes before/after microsurgical or radiosurgical treatment. Methods: Thirty-eight patients with unilateral VS were included. Twenty-two received microsurgery, 16 CyberKnife radiosurgery. Two fol...

  8. 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.

  9. Climbing Fibers Mediate Vestibular Modulation of Both "Complex" and "Simple Spikes" in Purkinje Cells.

    Science.gov (United States)

    Barmack, N H; Yakhnitsa, V

    2015-10-01

    Climbing and mossy fibers comprise two distinct afferent paths to the cerebellum. Climbing fibers directly evoke a large multispiked action potential in Purkinje cells termed a "complex spike" (CS). By logical exclusion, the other class of Purkinje cell action potential, termed "simple spike" (SS), has often been attributed to activity conveyed by mossy fibers and relayed to Purkinje cells through granule cells. Here, we investigate the relative importance of climbing and mossy fiber pathways in modulating neuronal activity by recording extracellularly from Purkinje cells, as well as from mossy fiber terminals and interneurons in folia 8-10. Sinusoidal roll-tilt vestibular stimulation vigorously modulates the discharge of climbing and mossy fiber afferents, Purkinje cells, and interneurons in folia 9-10 in anesthetized mice. Roll-tilt onto the side ipsilateral to the recording site increases the discharge of both climbing fibers (CSs) and mossy fibers. However, the discharges of SSs decrease during ipsilateral roll-tilt. Unilateral microlesions of the beta nucleus (?-nucleus) of the inferior olive blocks vestibular modulation of both CSs and SSs in contralateral Purkinje cells. The blockage of SSs occurs even though primary and secondary vestibular mossy fibers remain intact. When mossy fiber afferents are damaged by a unilateral labyrinthectomy (UL), vestibular modulation of SSs in Purkinje cells ipsilateral to the UL remains intact. Two inhibitory interneurons, Golgi and stellate cells, could potentially contribute to climbing fiber-induced modulation of SSs. However, during sinusoidal roll-tilt, only stellate cells discharge appropriately out of phase with the discharge of SSs. Golgi cells discharge in phase with SSs. When the vestibularly modulated discharge is blocked by a microlesion of the inferior olive, the modulated discharge of CSs and SSs is also blocked. When the vestibular mossy fiber pathway is destroyed, vestibular modulation of ipsilateral CSs and SSs persists. We conclude that climbing fibers are primarily responsible for the vestibularly modulated discharge of both CSs and SSs. Modulation of the discharge of SSs is likely caused by climbing fiber-evoked stellate cell inhibition. PMID:26424151

  10. Perspectives in vestibular diagnostics and therapy

    OpenAIRE

    Ernst, Arneborg

    2012-01-01

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

  11. Imaging Finding in 222 Patients with Vestibular

    OpenAIRE

    A. Zahiri

    2008-01-01

    Background/Objective: Vestibular Schwannoma is the most common cranial schwannoma with gradually produce sensorineural deafness. In this study we observed the effect of Gamma Knife therapy for control of this type of schwannoma."nPatients and Methods: We observed imaging findings of 250 patients with vestibular schwannoma from September 2003 to October 2007. We performed the Gamma Knife with C model (Elekta Company) for the treatment and control of the tumor."nResults: The minimum a...

  12. Vestibular schwannoma: role of conservative management

    OpenAIRE

    Suryanarayanan, R; Ramsden, R T; Saeed, S R; Aggarwal, R; King, A. T.; Rutherford, S. A.; Evans, D. G.; Gillespie, J. E.

    2010-01-01

    Objective: To assess the outcome of conservative management of vestibular schwannoma.Study design: Observational study. Setting: Tertiary referral centre.Patients: Four hundred and thirty-six patients with vestibular schwannoma (490 tumours), including 327 sporadic tumours and 163 tumours in 109 patients with neurofibromatosis type two.Main outcome measures: The relationship of tumour growth to tumour size at presentation, and to certain demographic features.Results: The initial tumour size w...

  13. Cranial Nerve VIII: Hearing and Vestibular Functions

    OpenAIRE

    Sanders, Richard D; Gillig, Paulette Marie

    2010-01-01

    Cranial nerve VIII brings sound and information about one's position and movement in space into the brain. The auditory and vestibular systems subserve several functions basic to clinical medicine and to psychiatry. This article covers the basics of cranial nerve VIII, hearing and vestibular systems, including common problems with hearing and balance, problems with hearing and balance that tend to be found in psychiatric patients, and some simple assessments of value in clinical practice.

  14. Vestibular stimulation affects optic-flow sensitivity.

    Science.gov (United States)

    Edwards, Mark; O'Mahony, Simon; Ibbotson, Michael R; Kohlhagen, Stuart

    2010-01-01

    Typically, multiple cues can be used to generate a particular percept. Our area of interest is the extent to which humans are able to synergistically combine cues that are generated when moving through an environment. For example, movement through the environment leads to both visual (optic-flow) and vestibular stimulation, and studies have shown that non-human primates are able to combine these cues to generate a more accurate perception of heading than can be obtained with either cue in isolation. Here we investigate whether humans show a similar ability to synergistically combine optic-flow and vestibular cues. This was achieved by determining the sensitivity to optic-flow stimuli while physically moving the observer, and hence producing a vestibular signal, that was either consistent with the optic-flow signal, eg a radially expanding pattern coupled with forward motion, or inconsistent with it, eg a radially expanding pattern with backward motion. Results indicate that humans are more sensitive to motion-in-depth optic-flow stimuli when they are combined with complementary vestibular signals than when they are combined with conflicting vestibular signals. These results indicate that in humans, like in nonhuman primates, there is perceptual integration of visual and vestibular signals. PMID:21180352

  15. Achados vestibulares em pacientes portadores de fibromialgia

    Directory of Open Access Journals (Sweden)

    Zeigelboim, Bianca Simone

    2011-07-01

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

  16. 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.

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

    Scientific Electronic Library Online (English)

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

    2007-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Francisco Halilla Zanardini

    2007-06-01

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

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

    Scientific Electronic Library Online (English)

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

    2007-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Norma de Oliveira Penido

    2007-12-01

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

  1. The vestibular nuclei and vestibuloreticular connections in the mallard (Anas platyrhynchos L.). An anterograde and retrograde tracing study.

    Science.gov (United States)

    Tellegen, A J; Arends, J J; Dubbeldam, J L

    2001-01-01

    The vestibular apparatus provides information about the position and movements of the head. Craniocervical muscles position the head with respect to the upper part of the neck. Motoneurons innervating these muscles are located in the supraspinal nucleus and ventral horn of the rostral cervical cord. Premotor neurons of craniocervical muscles have been found in the medial two-thirds of the medullary reticular formation: the ventromedial part of the parvocellular reticular formation and the gigantocellular reticular formation. In the present study, projections from vestibular nuclei upon craniocervical premotor neurons were investigated using anterograde and retrograde tracers. Vestibulospinal fibers run bilaterally in the medial vestibulospinal tract and ipsilaterally in the lateral vestibulospinal tract. Vestibuloreticular projections are mainly ipsilateral, and originate from the n. vestibularis lateralis pars ventralis and pars dorsalis, and from the n. vestibularis descendens. Terminal labeling is found in the border zone between the parvocellular and gigantocellular reticular formation. These projections show that in addition to direct bilateral vestibulo-craniocervical projections an indirect vestibular pathway to craniocervical motor nuclei exists. The direct pathway probably is the neural substrate for the vestibulocollic reflex, whereas the vestibular projection upon the reticular formation might influence head orientation during various kinds of activities, such as pecking, preening and so on. PMID:11964497

  2. Functional stochastic resonance in human baroreflex induced by 1/f-type noisy galvanic vestibular stimulation

    Science.gov (United States)

    Soma, Rika; Kwak, Shin; Yamamoto, Yoshiharu

    2003-05-01

    We hypothesized that 1/f noise is more beneficial than the conventional white noise in optimizing the brain's response to a weak input signal, and showed that externally added 1/f noise outperforms white noise in sensitizing human baroreflex centers in the brain. We examined the compensatory heart rate response to weak periodic signal introduced at the venous blood pressure receptor, while adding either 1/f or white noise with the same variance to the brain stem by electrically stimulating the bilateral vestibular afferents cutaneously. This stochastic galvanic vestibular stimulation, activating the vestibulo-sympathetic pathway in the brain stem, optimized covariance between weak input signals and the heart rate responses both with 1/f and white noise. Further, the optimal noise level with 1/f noise was significantly lower than that with white noise, suggesting the functional benefit of 1/f noise for the neuronal information transfer in the brain.

  3. Tests of walking balance for screening vestibular disorders

    OpenAIRE

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

    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...

  4. The thalamocortical vestibular system in animals and humans

    OpenAIRE

    Lopez, Christophe; Blanke, Olaf

    2011-01-01

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

  5. Use of Galvanic Vestibular Feedback for a Balance Prosthesis

    OpenAIRE

    Peterka, Robert J.

    2012-01-01

    Activation of vestibular afferents by a bilateral bipolar galvanic vestibular stimulus (GVS) evokes medial-lateral (ML) body sway. By applying a GVS feedback signal that is a function of measured ML head motion, the potential exists for GVS to restore a useful vestibular contribution to ML balance control in vestibular-deficient subjects who remain responsive to GVS. A key to developing an effective balance prosthesis using GVS is to determine the functional relationship between GVS and its i...

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

    OpenAIRE

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

    2015-01-01

    The vestibular system is crucial for postural control; however there are considerable differences in the task dependence and frequency response of vestibular reflexes in appendicular and axial muscles. For example, vestibular reflexes are only evoked in appendicular muscles when vestibular information is relevant to postural control, while in neck muscles they are maintained regardless of the requirement to maintain head on trunk balance. Recent investigations have also shown that the bandwid...

  7. Vestibular Rehabilitation Therapy: Review of Indications, Mechanisms, and Key Exercises

    OpenAIRE

    Han, Byung In; Song, Hyun Seok; Kim, Ji Soo

    2011-01-01

    Vestibular rehabilitation therapy (VRT) is an exercise-based treatment program designed to promote vestibular adaptation and substitution. The goals of VRT are 1) to enhance gaze stability, 2) to enhance postural stability, 3) to improve vertigo, and 4) to improve activities of daily living. VRT facilitates vestibular recovery mechanisms: vestibular adaptation, substitution by the other eye-movement systems, substitution by vision, somatosensory cues, other postural strategies, and habituatio...

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

    Scientific Electronic Library Online (English)

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

    2011-03-01

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

  9. Caloric vestibular stimulation modulates nociceptive evoked potentials.

    Science.gov (United States)

    Ferrè, Elisa Raffaella; Haggard, Patrick; Bottini, Gabriella; Iannetti, Gian Domenico

    2015-12-01

    Vestibular stimulation has been reported to alleviate central pain. Clinical and physiological studies confirm pervasive interactions between vestibular signals and somatosensory circuits, including nociception. However, the neural mechanisms underlying vestibular-induced analgesia remain unclear, and previous clinical studies cannot rule out explanations based on alternative, non-specific effects such as distraction or placebo. To investigate how vestibular inputs influence nociception, we combined caloric vestibular stimulation (CVS) with psychophysical and electrocortical responses elicited by nociceptive-specific laser stimulation in humans (laser-evoked potentials, LEPs). Cold water CVS applied to the left ear resulted in significantly lower subjective pain intensity for experimental laser pain to the left hand immediately after CVS, relative both to before CVS and to 1 h after CVS. This transient reduction in pain perception was associated with reduced amplitude of all LEP components, including the early N1 wave reflecting the first arrival of nociceptive input to primary somatosensory cortex. We conclude that cold left ear CVS elicits a modulation of both nociceptive processing and pain perception. The analgesic effect induced by CVS could be mediated either by subcortical gating of the ascending nociceptive input, or by direct modulation of the primary somatosensory cortex. PMID:26282602

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

    Scientific Electronic Library Online (English)

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

    2009-06-01

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

  11. 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.

  12. 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.

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

    Scientific Electronic Library Online (English)

    Bianca Simone, Zeigelboim; Denise Nunnes, Moreira.

    2011-09-01

    Full Text Available INTRODUÇÃO: A fibromialgia (FM) é uma síndrome musculoesquelética não inflamatória, de caráter crônico, de etiologia desconhecida, caracterizada por dor difusa, aumento da sensibilidade na palpação e por sintomas como fadiga, insônia, ansiedade, depressão, intolerância ao frio e queixas otológicas. [...] OBJETIVO: Avaliar o comportamento vestibular em pacientes portadores de fibromialgia. MÉTODO: Foi realizado um estudo retrospectivo de corte transversal. Avaliaram-se 25 pacientes na faixa etária entre 26 e 65 anos (média de idade - 52,2 anos e desvio padrão - 10,3 anos), submetidos aos seguintes procedimentos: anamnese, avaliação otorrinolaringológica e vestibular por meio da vectoeletronistagmografia. RESULTADOS: a) Os sintomas otoneurológicos mais evidenciados foram: dificuldade ou dor ao movimento do pescoço e dor irradiada para ombro ou braço (92,0%) em cada, tontura (84,0%) e cefaleia (76,0%). Os sintomas clínicos diversos mais relatados foram: depressão (80,0%), ansiedade (76,0%) e insônia (72,0%); b) O exame vestibular esteve alterado em 12 pacientes (48,0%) sendo localizado na prova calórica; c) Houve prevalência de alteração no sistema vestibular periférico e, d) Houve predomínio das disfunções vestibulares periféricas deficitárias. CONCLUSÃO: Este estudo permitiu verificar a importância do exame labiríntico o que ressalta que esse tipo de população deveria ser melhor estudada, uma vez que diversas doenças reumatológicas pelas suas manifestações e áreas de comprometimento podem gerar alterações vestibulares importantes. Abstract in english INTRODUCTION: Fibromyalgia (FM) is a non-inflammatory musculoskeletal chronic syndrome, whose etiology is unknown, characterized by a diffuse pain, increase in palpation sensitivity and such symptoms as tiredness, insomnia, anxiety, depression, cold intolerance and otologic complaints. OBJECTIVE: Ev [...] aluate the vestibular behavior in fibromyalgia patients. METHOD: A retrospective transversal study was performed. 25 patients aged between 26 and 65 (average age - 52. 2 and standard deviation - 10. 3) were evaluated and submitted to the following procedures: anamnesis, otorhinolaryngologic and vestibular evaluation by way of vector electronystamography. RESULTS: a) The most evident otoneurologic symptoms were: difficulty or pain when moving the neck and pain was spread to an arm or shoulder (92. 0%) in each, dizziness (84. 0%) and headache (76. 0%). The different clinical symptoms mostly reported were: depression (80. 0%), anxiety (76. 0%) and insomnia (72. 0%); b) vestibular examination showed an alteration in 12 patients (48. 0%) in the caloric test; c) an alteration in the peripheral vestibular system prevailed, and d) deficient peripheral vestibular disorders were prevalent. CONCLUSION: This study enabled the importance of the labyrinthic test to be verified, thus emphasizing that this kind of people must be studied better, since a range of rheumatologic diseases can cause severe vestibular changes as a result of their manifestations and impairment areas.

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

    Scientific Electronic Library Online (English)

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

    2005-03-01

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

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

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    Bianca Simone Zeigelboim

    2007-06-01

    Full Text Available OBJETIVO: avaliar o comportamento vestibular em pacientes com disfunção temporomandibular. MÉTODOS: avaliaram-se 27 pacientes do sexo feminino, na faixa etária de 30 a 53 anos, encaminhadas do Centro de Diagnóstico e Tratamento da Articulação Temporomandibular para o Laboratório de Otoneurologia da Universidade Tuiuti do Paraná. Realizaram-se os seguintes procedimentos: anamnese, inspeção otológica e avaliação vestibular por meio da vectoeletronistagmografia. RESULTADOS: as queixas mais freqüentes foram: dificuldade ou dor ao movimento do pescoço (77,7%, dor irradiada para ombro/braço (77,7%, zumbido e formigamento de extremidade superior (77,7%, tontura e dor de cabeça (66,6%, ansiedade (55,5%, sensação de cabeça oca (51,8%, agitação durante o sono (51,8% e depressão (51,8%. O exame vestibular esteve alterado em 20 pacientes (74,0% na prova calórica. Houve freqüência de alteração no sistema vestibular periférico. Houve predomínio das síndromes vestibulares periféricas deficitárias. CONCLUSÃO: ressalta-se a importância de se estudar a relação do sistema vestibular com a disfunção temporomandibular uma vez que observamos, na presente pesquisa, um número elevado de alteração no exame labiríntico.PURPOSE: to evaluate the vestibular functioning in patients with temporomandibular joint dysfunction. METHODS: 27 female patients were evaluated, with age varying from 30 to 53-year-old, referred from the Centre of Diagnosis and Treatment of Temporomandibular Joint Dysfunction to the Otoneurological Laboratory of Tuiuti University of Paraná. The following exams were carried out: anamnesis, otoscopy and vestibular evaluations through vectoelectronystagmography. RESULTS: the most frequent complaints were: difficulty or pain with movement of the neck (77.7%, pain irradiated to the shoulder/arm (77.7%, tinnitus and paresthesia of superior extremities (77.7% in each one, dizziness and headaches (66,6%, anxiety (55.5%, empty head sensations, agitation during sleep and depression (51.8% in each one. The vestibular exam showed alterations in 20 patients (74.0% in the caloric test. There was a prevalence of alterations in the peripheral vestibular system. There was a prevalence of deficient peripheral vestibular syndrome. CONCLUSION: the importance of studying the relationship between the vestibular system and temporomandibular joint dysfunction is emphasized, since a high number of alterations in the labyrinthic exam have been noted in this research.

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

    Scientific Electronic Library Online (English)

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

    2014-01-01

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

  17. Vestibular schwannoma: anatomical, medical and surgical perspective

    OpenAIRE

    Ashfaq Ul Hassan; Ghulam Hassan; Zahida Rasool

    2013-01-01

    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(3.0...

  18. 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

  19. Asymmetry of balance responses to monaural galvanic vestibular stimulation in subjects with vestibular schwannoma?

    OpenAIRE

    Welgampola, M. S.; Ramsay, E; Gleeson, M. J.; Day, B.L.

    2013-01-01

    OBJECTIVE: We investigated the potential of galvanic vestibular stimulation (GVS) to quantify lateralised asymmetry of the vestibulospinal pathways by measuring balance responses to monaural GVS in 10 subjects with vestibular schwannoma and 22 healthy control subjects. METHODS: Subjects standing without vision were stimulated with 3s, 1mA direct current stimuli delivered monaurally. The mean magnitude and direction of the evoked balance responses in the horizontal plane were measured from gro...

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

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    Zucca Gianpiero

    2009-06-01

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

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

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    Tatiane Maria Rossi

    2009-01-01

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

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

    Scientific Electronic Library Online (English)

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

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

  3. 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.

  4. 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…

  5. Perspectives in vestibular diagnostics and therapy [

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    Ernst, Arneborg

    2012-04-01

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

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

    Directory of Open Access Journals (Sweden)

    Alejandro Peña M

    2012-04-01

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

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

    Scientific Electronic Library Online (English)

    Alejandro, Peña M.

    2012-04-01

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

  8. 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).

  9. 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.

  10. 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.

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

    Scientific Electronic Library Online (English)

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

    2014-07-01

    Full Text Available INTRODUÇÃO: Pacientes com hipofunção vestibular, achado típico em vestibulopatias periféricas, apresentam alterações de equilíbrio corporal. OBJETIVO: Avaliar o controle postural de pacientes vertiginosos com hipofunção vestibular unilateral. MÉTODO: Trata-se de um estudo clínico transvers [...] al. No total, 25 pacientes vertiginosos com hipofunção vestibular unilateral e um grupo controle homogêneo de 32 indivíduos hígidos foram submetidos à avaliação otoneurológica, incluindo a posturografia do Tetrax Interactive Balance System em oito diferentes condições sensoriais. RESULTADOS: O grupo experimental apresentou valores significantemente maiores do que o grupo controle quanto ao índice de estabilidade geral, índice de distribuição de peso, índice de sincronização da oscilação postural direita/esquerda e dedos/calcanhar, faixas de frequência de oscilação postural (F1, F2-F4, F5-F6, F7-F8) e índice de risco de queda, em diferentes condições sensoriais. CONCLUSÃO: Alterações de distribuição de peso, sincronização da oscilação postural direita/esquerda e dedos/calcanhares, faixas de frequência de oscilação postural e do índice de risco de queda caracterizam o comprometimento do controle postural em pacientes vertiginosos com hipofunção vestibular unilateral. Abstract in english INTRODUCTION: Patients with vestibular hypofunction, a typical finding in peripheral vestibular disorders, show body balance alterations. OBJECTIVE: To evaluate the postural control of patients with vertigo and unilateral vestibular hypofunction. METHOD: This is a clinical cross-sectional [...] study. Twenty-five patients with vertigo and unilateral vestibular hypofunction and a homogeneous control group consisting of 32 healthy individuals were submitted to a neurotological evaluation including the Tetrax Interactive Balance System posturography in eight different sensory conditions. RESULTS: For different positions, vertiginous patients with unilateral vestibular hypofunction showed significantly higher values of general stability index, weight distribution index, right/left and tool/heel synchronizations, Fourier transformation index and fall index than controls. CONCLUSION: Increased values in the indices of weight distribution, right/left and tool/heel synchronizations, Fourier transformation and fall risk characterize the impairment of postural control in patients with vertigo and unilateral vestibular hypofunction.

  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. Anxiety Changes Depersonalization and Derealization Symptoms in Vestibular Patients

    Science.gov (United States)

    Kolev, Ognyan I.; Georgieva-Zhostova, Spaska O.; Berthoz, Alain

    2014-01-01

    Background. Depersonalization and derealization are common symptoms reported in the general population. Objective. The aim of the present study was to establish the relationship between anxiety and depersonalization and derealization symptoms in patients with peripheral vestibular disorders. Methods. Twenty-four vestibular patients with anxiety and 18 vestibular patients without anxiety were examined for depersonalization and derealization symptoms. They were also compared to healthy controls. Results. The results revealed that anxiety consistently changes depersonalization and derealization symptoms in vestibular patients. They are more frequent, more severe, and qualitatively different in vestibular patients with anxiety than in those without anxiety. Conclusion. Anxiety has an effect on depersonalization and derealization symptoms in vestibular patients. The various hypotheses about the underlying mechanism of this effect were discussed. PMID:24803735

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

    Scientific Electronic Library Online (English)

    Alejandro, Peña M.

    2011-08-01

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

  15. How vestibular stimulation interacts with illusory hand ownership

    OpenAIRE

    Lopez, Christophe; Lenggenhager, Bigna; Blanke, Olaf

    2010-01-01

    Artificial stimulation of the peripheral vestibular system has been shown to improve ownership of body parts in neurological patients, suggesting vestibular contributions to bodily self-consciousness. Here, we investigated whether galvanic vestibular stimulation (GVS) interferes with the mechanisms underlying ownership, touch, and the localization of one's own hand in healthy participants by using the "rubber hand illusion" paradigm. Our results show that left anodal GVS increases illusory ow...

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

    OpenAIRE

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

    2005-01-01

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

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

    OpenAIRE

    Kingma, Charlotte Mariane,

    2011-01-01

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

  18. 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...

  19. 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, conservati...

  20. Anxiety Changes Depersonalization and Derealization Symptoms in Vestibular Patients

    OpenAIRE

    Kolev, Ognyan I.; Georgieva-Zhostova, Spaska O.; Berthoz, Alain

    2014-01-01

    Background. Depersonalization and derealization are common symptoms reported in the general population. Objective. The aim of the present study was to establish the relationship between anxiety and depersonalization and derealization symptoms in patients with peripheral vestibular disorders. Methods. Twenty-four vestibular patients with anxiety and 18 vestibular patients without anxiety were examined for depersonalization and derealization symptoms. They were also compared to healthy controls...

  1. 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...

  2. Ernst Mach on the vestibular organ 100 years ago

    Science.gov (United States)

    Henn, V.; Young, L. R.

    1975-01-01

    The paper reviews the contributions of Ernst Mach to vestibular research. His experiments, mainly psychophysical in nature, included measurements of threshold and investigation of the vestibular-visual interaction. Among his conclusions are that the adequate stimulus for the semicircular canals must be pressure, and that the sustained endolymph flow theory of Breuer (1874) and Crum Brown (1874) is erroneous. Excerpts are given of Mach's publications on vestibular functions.-

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

    Directory of Open Access Journals (Sweden)

    Patrick A Forbes

    2015-01-01

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

  4. Experiment M131. Human vestibular function

    Science.gov (United States)

    Graybiel, A.; Miller, E. F., II; Homick, J. L.

    1977-01-01

    The lower susceptibility to vestibular stimulation aloft, compared with that on ground under experimental conditions, is attributed to a precondition, namely, either there is no need to adapt, or, as exemplified by the Skylab 3 pilot, adaptation to weightlessness is achieved. Findings in some of the astronauts emphasize the distinction between two categories of vestibular side effects: immediate reflex phenomena (illusions, sensations of turning, etc.), and delayed epiphenomena that include the constellation of symptoms and syndromes comprising motion sickness. The drug combinations 1-scopolamine and d-amphetamine and promethazine hydrochloride and ephedrine sulfate are effective in prevention and treatment of motion sickness. It is concluded that prevention of motion sickness in any stressful motion environment involves selection, adaptation, and the use of drugs.

  5. Vestibular Schwannoma Atypically Invading Temporal Bone

    Science.gov (United States)

    Park, Soo Jeong; Yang, Na-Rae

    2015-01-01

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

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

    Science.gov (United States)

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

    2005-11-01

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

  7. Complications of microsurgery of vestibular schwannoma.

    Czech Academy of Sciences Publication Activity Database

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

    2014-01-01

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

  8. 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. Participants were 1244 patients who underwent translabyrinthine surgery during a period of 33 years from 1976 to 2009. Main outcome measures were tumor removal, intraoperative facial nerve preservation, complicat...

  9. Imaging Finding in 222 Patients with Vestibular

    Directory of Open Access Journals (Sweden)

    A. Zahiri

    2008-01-01

    Full Text Available Background/Objective: Vestibular Schwannoma is the most common cranial schwannoma with gradually produce sensorineural deafness. In this study we observed the effect of Gamma Knife therapy for control of this type of schwannoma."nPatients and Methods: We observed imaging findings of 250 patients with vestibular schwannoma from September 2003 to October 2007. We performed the Gamma Knife with C model (Elekta Company for the treatment and control of the tumor."nResults: The minimum age of our patients was 14 years and maximum age was 90 years. Twenty six patients was N.F.2, and female to male ratio was 2/1. The most common imaging finding was loss of central contrast enhancement in contrast MRI beginning after nine months after Gamma Knife. Loss of volume and cystic changes were other imaging findings and regrowth of tumor was seen in same case. After three years follow up, tumor control, tumor regression, and tumor enlargement were seen in 85%, 10%, and 5% of our patients respectively."nConclusion: Gamma Knife should be considered as a suitable treatment option for the treatment of Vestibular Schwannoma.

  10. 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)

  11. Radiotherapy for Vestibular Schwannomas: A Critical Review

    International Nuclear Information System (INIS)

    Vestibular schwannomas are slow-growing tumors of the myelin-forming cells that cover cranial nerve VIII. The treatment options for patients with vestibular schwannoma include active observation, surgical management, and radiotherapy. However, the optimal treatment choice remains controversial. We have reviewed the available data and summarized the radiotherapeutic options, including single-session stereotactic radiosurgery, fractionated conventional radiotherapy, fractionated stereotactic radiotherapy, and proton beam therapy. The comparisons of the various radiotherapy modalities have been based on single-institution experiences, which have shown excellent tumor control rates of 91-100%. Both stereotactic radiosurgery and fractionated stereotactic radiotherapy have successfully improved cranial nerve V and VII preservation to >95%. The mixed data regarding the ideal hearing preservation therapy, inherent biases in patient selection, and differences in outcome analysis have made the comparison across radiotherapeutic modalities difficult. Early experience using proton therapy for vestibular schwannoma treatment demonstrated local control rates of 84-100% but disappointing hearing preservation rates of 33-42%. Efforts to improve radiotherapy delivery will focus on refined dosimetry with the goal of reducing the dose to the critical structures. As future randomized trials are unlikely, we suggest regimented pre- and post-treatment assessments, including validated evaluations of cranial nerves V, VII, and VIII, and quality of life assessments with long-term prospective follow-up. The results from such trials will enhance the understanding of therapy outcomes and improve our ability to inform patients.

  12. 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.

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

    Scientific Electronic Library Online (English)

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

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

  14. Determining the direction of vestibular-evoked balance responses using stochastic vestibular stimulation.

    Science.gov (United States)

    Mian, Omar S; Day, Brian L

    2009-06-15

    As a tool for investigating vestibulo-motor function, stochastic vestibular stimulation (SVS) has some advantages over galvanic vestibular stimulation. However, there is no technique currently available for extracting direction information from SVS-evoked motor responses. It is essential to be able to measure the direction of response if one wishes to investigate the operation of key spatial transformation processes in the brain. Here we describe and validate a technique for determining the direction of SVS-evoked balance responses based on the correlation between a random waveform of stimulating current and ground-reaction shear force. PMID:19417096

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

    Scientific Electronic Library Online (English)

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

    2010-02-01

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

  16. Reabilitação vestibular no tratamento da tontura e do zumbido / Vestibular rehabilitation in the treatment of dizziness and tinnitus

    Scientific Electronic Library Online (English)

    Bianca Simone, Zeigelboim; Marine Raquel Diniz da, Rosa; Karlin Fabianne, Klagenberg; Ari Leon, Jurkiewicz.

    Full Text Available OBJETIVO: Verificar a efetividade dos exercícios de reabilitação vestibular na melhora do zumbido e da tontura por meio de avaliação pré e pós-aplicação do questionário Dizziness Handicap Inventory (DHI) e Tinnitus Handicap Inventory (THI), ambos adaptados à população brasileira. MÉTODOS: Avaliaram- [...] se seis pacientes (dois do sexo masculino e quatro do sexo feminino), na faixa etária de 43 a 70 anos. Os pacientes foram submetidos aos seguintes procedimentos: anamnese, inspeção otológica, avaliação vestibular por meio da vectoeletronistagmografia e aplicação dos questionários pré e pós-reabilitação vestibular, utilizando-se o protocolo de Cawthorne e Cooksey. RESULTADOS: a) com relação às queixas mais referidas, observou-se desequilíbrio à marcha (83,3%), dor de cabeça (66,6%) e depressão (66,6%); b) no exame vestibular todos os pacientes apresentaram alteração na prova calórica, sendo a maior freqüência das síndromes vestibulares periféricas irritativas (83,3%); c) constataram-se no exame vestibular dois casos de síndrome vestibular periférica irritativa, dois casos de síndrome vestibular periférica irritativa unilateral; um caso de síndrome vestibular periférica irritativa bilateral e um caso de síndrome vestibular periférica deficitária unilateral; d) na aplicação do DHI, observou-se melhora nos aspectos: funcional e emocional, mantendo-se inalterado o aspecto físico; e) na aplicação do THI, observou-se melhora em todos os aspectos avaliados. CONCLUSÃO: O protocolo utilizado de reabilitação vestibular promoveu diminuição do zumbido e da tontura, melhorando a qualidade de vida dos pacientes. Abstract in english PURPOSE: To verify the effectiveness of vestibular rehabilitation exercises in the improvement of tinnitus and dizziness through an evaluation carried out before and after the administration of the Dizziness Handicap Inventory (DHI) and the Tinnitus Handicap Inventory (DHI) questionnaires, both adap [...] ted to the Brazilian population. METHODS: Six patients (two male and four female), with ages ranging from 43 to 70 years, were evaluated. The patients were submitted to the following procedures: anamnesis, otoscopy, vestibular evaluation through vectoelectronystagmography, and administration of the questionnaires, before and after vestibular rehabilitation, using the Cawthorne and Cooksey protocol. RESULTS: a) regarding the most related complaints, imbalance when walking (83,3%), headache (66,6%) and depression (66,6%), were observed; b) in the vestibular exam all the patients showed alterations in the caloric test, and the most frequent syndrome was the irritative peripheral vestibular (83,3%); c) two cases of irritative peripheral vestibular syndrome, two cases of irritative peripheral unilateral vestibular syndrome, one case of irritative peripheral bilateral vestibular syndrome and one case of peripheral deficient unilateral vestibular syndrome were verified in the vestibular exam; d) in the administration of the DHI, an improvement in the functional and emotional aspects were observed, with the physical aspect remaining unchanged; e) in the administration of the THI, an improvement was observed in all the aspects evaluated. CONCLUSION: The protocol of vestibular rehabilitation used in the study, promoted a decrease in tinnitus and dizziness, hence improving the quality of life of the patients.

  17. Reabilitação vestibular no tratamento da tontura e do zumbido Vestibular rehabilitation in the treatment of dizziness and tinnitus

    Directory of Open Access Journals (Sweden)

    Bianca Simone Zeigelboim

    2008-01-01

    Full Text Available OBJETIVO: Verificar a efetividade dos exercícios de reabilitação vestibular na melhora do zumbido e da tontura por meio de avaliação pré e pós-aplicação do questionário Dizziness Handicap Inventory (DHI e Tinnitus Handicap Inventory (THI, ambos adaptados à população brasileira. MÉTODOS: Avaliaram-se seis pacientes (dois do sexo masculino e quatro do sexo feminino, na faixa etária de 43 a 70 anos. Os pacientes foram submetidos aos seguintes procedimentos: anamnese, inspeção otológica, avaliação vestibular por meio da vectoeletronistagmografia e aplicação dos questionários pré e pós-reabilitação vestibular, utilizando-se o protocolo de Cawthorne e Cooksey. RESULTADOS: a com relação às queixas mais referidas, observou-se desequilíbrio à marcha (83,3%, dor de cabeça (66,6% e depressão (66,6%; b no exame vestibular todos os pacientes apresentaram alteração na prova calórica, sendo a maior freqüência das síndromes vestibulares periféricas irritativas (83,3%; c constataram-se no exame vestibular dois casos de síndrome vestibular periférica irritativa, dois casos de síndrome vestibular periférica irritativa unilateral; um caso de síndrome vestibular periférica irritativa bilateral e um caso de síndrome vestibular periférica deficitária unilateral; d na aplicação do DHI, observou-se melhora nos aspectos: funcional e emocional, mantendo-se inalterado o aspecto físico; e na aplicação do THI, observou-se melhora em todos os aspectos avaliados. CONCLUSÃO: O protocolo utilizado de reabilitação vestibular promoveu diminuição do zumbido e da tontura, melhorando a qualidade de vida dos pacientes.PURPOSE: To verify the effectiveness of vestibular rehabilitation exercises in the improvement of tinnitus and dizziness through an evaluation carried out before and after the administration of the Dizziness Handicap Inventory (DHI and the Tinnitus Handicap Inventory (DHI questionnaires, both adapted to the Brazilian population. METHODS: Six patients (two male and four female, with ages ranging from 43 to 70 years, were evaluated. The patients were submitted to the following procedures: anamnesis, otoscopy, vestibular evaluation through vectoelectronystagmography, and administration of the questionnaires, before and after vestibular rehabilitation, using the Cawthorne and Cooksey protocol. RESULTS: a regarding the most related complaints, imbalance when walking (83,3%, headache (66,6% and depression (66,6%, were observed; b in the vestibular exam all the patients showed alterations in the caloric test, and the most frequent syndrome was the irritative peripheral vestibular (83,3%; c two cases of irritative peripheral vestibular syndrome, two cases of irritative peripheral unilateral vestibular syndrome, one case of irritative peripheral bilateral vestibular syndrome and one case of peripheral deficient unilateral vestibular syndrome were verified in the vestibular exam; d in the administration of the DHI, an improvement in the functional and emotional aspects were observed, with the physical aspect remaining unchanged; e in the administration of the THI, an improvement was observed in all the aspects evaluated. CONCLUSION: The protocol of vestibular rehabilitation used in the study, promoted a decrease in tinnitus and dizziness, hence improving the quality of life of the patients.

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

    Science.gov (United States)

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

    2015-05-01

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

  19. 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.

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

    OpenAIRE

    Joseph B.; Rajshekhar V

    2002-01-01

    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.

  1.  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.

  2. 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.

  3. Vestibular PREHAB and gentamicin before schwannoma surgery may improve long-term postural function

    OpenAIRE

    Tjernström, Fredrik; Fransson, Per-Anders; Kahlon, Babar; Karlberg, Mikael; Lindberg, Sven; Siesjö, Peter; Magnusson, Måns

    2009-01-01

    Abstract Background: Unilateral vestibular deafferentation (uVD), as performed in vestibular schwannoma surgery, results in a chronic vestibular deficit, though most of the insufficiency can be compensated by other sensory input. By vestibular training (prehabituation) performed before surgery, motor adaptation processes can be instigated before the actual lesion. The adaptation processes of the altered sensory input could be affected if the vestibular ablation and surgery was sepa...

  4. Passive motion reduces vestibular balance and perceptual responses.

    Science.gov (United States)

    Fitzpatrick, Richard C; Watson, Shaun R D

    2015-05-15

    With the hypothesis that vestibular sensitivity is regulated to deal with a range of environmental motion conditions, we explored the effects of passive whole-body motion on vestibular perceptual and balance responses. In 10 subjects, vestibular responses were measured before and after a period of imposed passive motion. Vestibulospinal balance reflexes during standing evoked by galvanic vestibular stimulation (GVS) were measured as shear reaction forces. Perceptual tests measured thresholds for detecting angular motion, perceptions of suprathreshold rotation and perceptions of GVS-evoked illusory rotation. The imposed conditioning motion was 10 min of stochastic yaw rotation (0.5-2.5 Hz ? 300 deg s(-2) ) with subjects seated. This conditioning markedly reduced reflexive and perceptual responses. The medium latency galvanic reflex (300-350 ms) was halved in amplitude (48%; P = 0.011) but the short latency response was unaffected. Thresholds for detecting imposed rotation more than doubled (248%; P vestibular sensations of rotation evoked by GVS (mean 113 deg for 10 s at 1 mA) by 44% (P vestibular sensory autoregulation exists and that this probably involves central and peripheral mechanisms, possibly through vestibular efferent regulation. We propose that failure of these regulatory mechanisms at different levels could lead to disorders of movement perception and balance control during standing. PMID:25809702

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

    Scientific Electronic Library Online (English)

    Bianca Simone, Zeigelboim; Cláudia, Mittelmann.

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

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

    Scientific Electronic Library Online (English)

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

    2013-02-01

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

  7. 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)

  8. Progressive vestibular mutation leads to elevated anxiety.

    Science.gov (United States)

    Shefer, Shahar; Gordon, Carlos R; Avraham, Karen B; Mintz, Matti

    2010-03-01

    Anxiety disorders are among the most common mental disorders, and are comorbid with balance disorders in a significant proportion of these individuals. Presently, it is unclear whether anxiety and balance disorders are causally related, and what direction this causality may take. We argue that balance disorders may predispose an individual to anxiety and that demonstration of such causality may be informative to the development of preferred treatment for such individuals. To demonstrate that balance disorders may predispose to anxiety, we studied headbanger (Hdb) mutant mice in which the balance disorder is due to progressive vestibular impairment and wildtype (Wt) mice. Balance was assessed by swim and tail-hang tests that demonstrated clear behavioral balance deficits in the Hdb mice. Anxiety was assessed by open-field and elevated plus-maze tests, which confirmed elevated anxiety in the Hdb mice. These findings demonstrate that congenital vestibular genotype predisposes the animal to elevated levels of anxiety in space-related tests. Similar causality in clinics may redirect treatment strategies in afflicted patients. PMID:20043895

  9. Improving Sensorimotor Function Using Stochastic Vestibular Stimulation

    Science.gov (United States)

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

    2014-01-01

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

  10. The Development of the Vestibular Apparatus Under Conditions of Weightlessness

    Science.gov (United States)

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

    1984-01-01

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

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

    Scientific Electronic Library Online (English)

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

    2014-10-01

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

  12. [Myogenic vestibular evoked potentials used to objective estimation of effectiveness of central action drugs].

    Science.gov (United States)

    Morawiec-Bajda, A; Wasilewski, B

    2000-01-01

    In this paper possibility of employing vestibular evoked myogenic potentials (VEMPs) was evaluated to following efficacy of drug effect in patients with central and peripheral vestibular disorders of various aetiologies. Also influence of antihomotoxic remedies on sacculo-collic reflex function were followed. Treatment concerned 23 ills that is 20 women and 3 men in age from 20 to 68 years, average age being 46,82 years. The studied population included 8 patients were diagnosed to have Meniere's disease, 5 ills suffered from neuronitis vestibularis, 5 patients complained of vertigo of vertebrobasilar arterial insufficiency. 3 patients were diagnosed to have vertigo after head trauma, 1 patient suffered from benign paroxysmal positional vertigo and one's cause of disease was unknown. Patients with tumor of ponto-cerebellaris angle or VIII nerve were excluded. Registration of VEMPs was done in all patients treated before starting and after stopping therapy. After using of Cerebrum comp. improvement of vestibulo-spinal reflex function was affirmed in the form of shorted latencies and higher amplitudes of VEMPs in the most patients. Using sublingually of Vertigoheel distinct greater amplitudes were observed in significant numbers of patients after therapy. Administered of placebo did not essential influence on values of VEMPs parameters. PMID:10917061

  13. Nitric Oxide Signaling in Hypergravity-Induced Neuronal Plasticity

    Science.gov (United States)

    Holstein, Gay R.

    2003-01-01

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

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

    Scientific Electronic Library Online (English)

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

    2007-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Leandro Luís Martins

    2009-10-01

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

  16. Balancing awareness: Vestibular signals modulate visual consciousness in the absence of awareness.

    Science.gov (United States)

    Salomon, Roy; Kaliuzhna, Mariia; Herbelin, Bruno; Blanke, Olaf

    2015-11-01

    The processing of visual and vestibular information is crucial for perceiving self-motion. Visual cues, such as optic flow, have been shown to induce and alter vestibular percepts, yet the role of vestibular information in shaping visual awareness remains unclear. Here we investigated if vestibular signals influence the access to awareness of invisible visual signals. Using natural vestibular stimulation (passive yaw rotations) on a vestibular self-motion platform, and optic flow masked through continuous flash suppression (CFS) we tested if congruent visual-vestibular information would break interocular suppression more rapidly than incongruent information. We found that when the unseen optic flow was congruent with the vestibular signals perceptual suppression as quantified with the CFS paradigm was broken more rapidly than when it was incongruent. We argue that vestibular signals impact the formation of visual awareness through enhanced access to awareness for congruent multisensory stimulation. PMID:26204565

  17. 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

  18. Distinct spontaneous shrinkage of a sporadic vestibular schwannoma

    DEFF Research Database (Denmark)

    Huang, Xiaowen; Cayé-Thomasen, Per

    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 managed conservatively. Extreme shrinkage of the tumor may occur spontaneously.

  19. Concomitant occurrence of vestibular schwannoma and epidermoid tumor

    Directory of Open Access Journals (Sweden)

    B V Savitr Sastri

    2013-01-01

    Full Text Available The occurrence of two tumors adjacent to each other at the same site is very rare. We present here, a patient with a vestibular schwannoma found adjacent to an epidermoid tumor in the cerebellopontine angle.

  20. 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.

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

    Scientific Electronic Library Online (English)

    Aracy Pereira Silveira, Balbani; Jair Cortez, Montovani.

    2008-02-01

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

  2. Preoperative Audiovestibular Handicap in Patients with Vestibular Schwannoma

    OpenAIRE

    Humphriss, Rachel L.; Baguley, David M.; Axon, Patrick R.; Moffat, David A.

    2006-01-01

    Objectives: To evaluate preoperative hearing, dizziness, and tinnitus handicap in patients with unilateral vestibular schwannoma (VS). Design: Prospective administration of the Hearing Handicap Inventory (HHI), Dizziness Handicap Inventory (DHI), and Tinnitus Handicap Inventory (THI), prior to surgical intervention. Setting: A tertiary referral neuro-otology clinic. Participants: A total of 145 consecutive patients who were admitted for excision of their vestibular schwannomas between May 199...

  3. Vestibular schwannoma with malignant transformation: a case report.

    OpenAIRE

    Son, E. I.; Kim, I. M.; Kim, S.P.

    2001-01-01

    We describe a rare case of malignant transformation in a vestibular schwannoma in a 33-yr-old woman. She presented herself with headache, tinnitus, and hearing loss and underwent posterior fossa explorations three times during the short period of 3 months. The clinicopathological features of the original tumor were typical of benign vestibular schwannoma. Despite a complete microsurgical excision, two months later, the tumor recurred locally with a rapid increase in size causing a progressive...

  4. 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...

  5. Double localization of a unilateral sporadic vestibular schwannoma

    OpenAIRE

    Barbara, M.; Ronchetti, F.; Manni, V.; Monini, S.

    2008-01-01

    Vestibular schwannoma may present as a sporadic or genetically-based multi-localized benign neoplasm of the internal auditory canal and/or cerebello-pontine angle region. Multiple localization is generally regarded as genetic in origin and often affects the stato-acoustic bundle on both sides. A case of double vestibular schwannoma localized on the same stato-acoustic bundle is presented. After removal, slight histological differences were found between the two separate masses. From these fin...

  6. 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

  7. Vestibular ataxia and its measurement in man

    Science.gov (United States)

    Fregly, A. R.

    1974-01-01

    Methods involved in and results obtained with a new comprehensive ataxia test battery are described, and definitions of spontaneous and induced vestibular ataxia in man are given in terms of these findings. In addition, the topic of alcohol-induced ataxia in relation to labyrinth function is investigated. Items in the test battery comprise a sharpened Romberg test, in which the subject stands on the floor with eyes closed and arms folded against his chest, feet heel-to-toe, for 60 seconds; an eyes-open walking test; an eyes-open standing test; an eyes-closed standing test; an eyes-closed on-leg standing test; an eyes-closed walk a line test; an eyes-closed heel-to-toe walking test; and supplementary ataxia tests such as the classical Romberg test.

  8. The European vestibular experiments in spacelab-1

    Science.gov (United States)

    Kass, J.; von Baumgarten, R.; Vogel, H.; Wetzig, J.; Benson, A.; Berthoz, A.; Vieville, Th.; Brandt, Th.; Probst, Th.; Brand, U.; Bruzek, W.; Dichgans, J.; Scherer, H.

    A series of experiments /1/ were performed in the Spacelab-1 mission on November/December, 1983, pre-, in-, and postflight. These experiments covered various aspects of the functions of the vestibular system, the inflight tests comprising threshold measurements for linear movements in three orthogonal axes, optokinetic stimulation, vestibulo-ocular reflexes under linear and angular accelerations, caloric stimulation with and without linear accelerations; pre- and postflight tests repeated the inflight protocol with the addition of subjective vertical and eye counter-rotation measurements using a tilt table. One of the most surprising and significant results was the caloric test: strong caloric nystagmus on the two subjects tested was recorded inflight; this was contrary to what was expected from Barany's convection hypothesis for caloric nystagmus.

  9. 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.

  10. 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.

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

    Scientific Electronic Library Online (English)

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

    2005-12-01

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

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

    Scientific Electronic Library Online (English)

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

    2009-06-01

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

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

    Scientific Electronic Library Online (English)

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

    2005-09-01

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

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

    Scientific Electronic Library Online (English)

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

    2011-12-01

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

  15. 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

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

    OpenAIRE

    Alexandre Secorun Borges; José Luiz de Mello Nicoletti; Armen Thomassian; Ênio Pedone Bandarra; Ana Laura Angeli

    2003-01-01

    Um eqüino com 22 anos de idade apresentou síndrome vestibular periférica associada à paralisia de nervo facial esquerdo devido à osteoartropatia temporoioídea. O exame endoscópico das bolsas guturais mostrou alteração de contorno da bula timpânica esquerda e aumento de volume da extremidade proximal do osso estiloióide do mesmo lado.A 22-year-old gelding showed vestibular syndrome associated with left facial nerve paralysis due to temporohyoid osteoarthropathy and the diagnostic was confirmed...

  17. 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.

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

    Scientific Electronic Library Online (English)

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

    2012-02-01

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

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

    Scientific Electronic Library Online (English)

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

    2013-06-01

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

  20. 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.

  1. 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.

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

    Science.gov (United States)

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

    2007-09-15

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

  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

    1985-01-01

    This study is an attempt to reveal projection areas for vestibular afferents to the human brain. Changes in regional cerebral blood flow (rCBF) were measured over 254 cortical regions during caloric vestibular stimulation with warm water (44 degrees C). rCBF was measured when the external auditory meatus was irrigated with water at body temperature as a control to vestibular stimulation. During vestibular stimulation there was only a single cortical area, located in the superior temporal region,...

  4. Postnatal expression of an apamin-sensitive K(Ca) current in vestibular calyx terminals

    OpenAIRE

    Meredith, Frances L.; Li, Gang Q.; Rennie, Katherine J.

    2011-01-01

    Afferent innervation patterns in the vestibular periphery are complex and vestibular afferents show a large variation in their regularity of firing. Calyx fibers terminate on type I vestibular hair cells and have firing characteristics distinct from bouton fibers that innervate type II hair cells. Whole cell patch clamp was used to investigate ionic currents that could influence firing patterns in calyx terminals. Underlying K(Ca) conductances have been described in vestibular ganglion cells,...

  5. 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.

  6. [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

  7. 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.

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

    Directory of Open Access Journals (Sweden)

    Mo Weike

    2010-09-01

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

  9. 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.

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

    Directory of Open Access Journals (Sweden)

    Elaine Shizue Novalo

    2007-12-01

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

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

    Scientific Electronic Library Online (English)

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

    2007-12-01

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

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

    Scientific Electronic Library Online (English)

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

    2014-12-01

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

  13. 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

  14. 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.

  15. Short latency vestibular evoked potentials in the chicken embryo

    Science.gov (United States)

    Jones, S. M.; Jones, T. A.

    1996-01-01

    Electrophysiological responses to pulsed linear acceleration stimuli were recorded in chicken embryos incubated for 19 or 20 days (E19/E20). Responses occurred within the first 16 ms following the stimulus onset. The evoked potentials disappeared following bilateral labyrinthectomy, but persisted following cochlear destruction alone, thus demonstrating that the responses were vestibular. Approximately 8 to 10 response peaks could be identified. The first 4 positive and corresponding negative components (early peaks with latencies embryos was -15.9dBre 1.0 g/ms, which was significantly higher (P embryos and 2-week-old animals, but amplitude/intensity functions for embryos were significantly shallower than those for 2-week-old birds (P embryo and, as such, the method shows promise as an investigative tool. The results of the present study form the definitive basis for using vestibular evoked potentials in the detailed study of avian vestibular ontogeny and factors that may influence it.

  16. 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

  17. 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.

  18. 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.

  19. Superior Semicircular Canal Dehiscence Syndrome without Vestibular Symptoms

    Scientific Electronic Library Online (English)

    Emidio Oliveira, Teixeira; Marconi Teixeira, Fonseca.

    2014-04-01

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

  20. Cervical Vestibular Evoked Myogenic Potentials in Idiopathic Parkinson Disease

    OpenAIRE

    Feray GÜLEÇ; Levent ÖCEK; Ya?ar ZORLU

    2012-01-01

    Aim: Postural instability is one of the main characteristic of idiopathic Parkinson's disease (iPD) with unknown cause. The aim of this study is to investigate the role of vestibular system in postural instability by using a modality, cervical vestibular evoked myogenic potentials (cVEMP).Methods: iPD group consisted of 20 patients, 11 female and 9 male, mean age 63,9± 10(43-84) years and control group 30 healthy volunteers, 16 males and 14 females, mean age 57,5 ± 10,5(36-78) years, without ...

  1. Avaliações audiométrica e vestibular em mulheres que utilizam o método contraceptivo hormonal oral / Audiometric and vestibular evaluation in women using the hormonal contraceptive method

    Scientific Electronic Library Online (English)

    Edson Ibrahim, Mitre; Alessandra Sousa, Figueira; Aparecida Barbosa, Rocha; Simone Maria Cordeiro, Alves.

    2006-06-01

    Full Text Available OBJETIVO: Correlacionar o uso de contraceptivo hormonal oral com possíveis alterações auditivas e vestibulares. MÉTODOS: Aplicou-se anamnese, teste audiométrico e teste vestibular em 60 mulheres entre 14 e 35 anos, sendo que 30 mulheres faziam uso do método contraceptivo hormonal oral composto por e [...] strógeno e progesterona (grupo de risco), por um período igual ou superior a 6 meses, sem queixas auditivas e vestibulares anteriores ao uso do mesmo; e 30 mulheres que nunca fizeram uso desses hormônios (grupo controle), sem queixas auditivas e vestibulares. A anamnese foi utilizada como critério de seleção da amostra. RESULTADOS: Com base nos achados otoneurológicos através de uma pesquisa quantitativa, pode-se verificar uma prevalência da Síndrome Vestibular Periférica Irritativa e de zumbidos no grupo de risco, sem alterações audiométricas. CONCLUSÃO: O uso do método contraceptivo hormonal oral pode ocasionar alterações funcionais na orelha interna, principalmente zumbido e Síndrome Vestibular Periférica Irritativa no grupo de risco, mas não evidenciou alterações de limiares auditivos. Abstract in english AIM: To co-relate the use of hormonal contraceptives with positive Auditory and Vestibular alterations. METHODS: medical history taking, audiometric test and vestibular test was applied to 60 women between the ages of 14 and 35 years old, and 30 of these women are on oral hormonal contraceptive cons [...] isting of Estrogen and Progesterone (risk group), for 6 months or more, that had no Auditory or Vestibular complaints prior to the usage of hormones; and 30 women that had never used these hormones (control group), with no Auditory or Vestibular complaints. Medical history was used to select the sample. RESULTS: Based on otoneurological findings, through quantitative research, we could see the prevailing Irritatative Peripheral Vestibular Syndrome and tinnitus in the risk group, without audiometric alterations. CONCLUSION: The use of oral contraceptives can provoke functional alterations in the inner ear, specially tinnitus and Irritative Peripheral Vestibular Syndrome in the risk group; but auditory threshold alterations were not evident.

  2. 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.

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

    Science.gov (United States)

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

    2011-11-01

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

  4. Volumetric Modulated Arc Radiotherapy for Vestibular Schwannomas

    International Nuclear Information System (INIS)

    Purpose: To evaluate volumetric modulated arc radiotherapy (RapidArc [RA]), a novel approach allowing for rapid treatment delivery, for the treatment of vestibular schwannoma (VS). Methods and Materials: The RA plans were generated for a small (0.5 cm3), intermediate (2.8 cm3), and large (14.8 cm3) VS. The prescription dose was 12.5 Gy to the encompassing 80% isodose. The RA plans were compared with conventional radiosurgery plans using both a single dynamic conformal arc (1DCA) and five noncoplanar dynamic conformal arcs (5DCA). Conformity indices (CI) and dose-volume histograms of critical organs were compared. The RA plan for the medium-sized VS was measured in a phantom using Gafchromic EBT films and compared with calculated dose distributions. Results: The RA planning was completed within 30 min in all cases, and calculated treatment delivery time (after patient setup) was 5 min vs. 20 min for 5DCA. A superior CI was achieved with RA, with a substantial decrease in low-dose irradiation of the normal brain achieved relative to 5DCA plans. Maximum doses to critical organs were similar for RA and 5DCA but were higher for 1DCA. Film measurements showed the differences between calculated and measured doses to be smaller than 1.5% in the high-dose area and smaller than 3% in the low-dose area. Conclusion: The RA plans consistently achieved a higher CI and decrease in areas of low-dose irradiation. This, together with shorter treatment delivery times, has led to RA replacing our conventional five-arc radiosurgery technique for VS.

  5. Repeat Gamma Knife surgery for vestibular schwannomas

    Science.gov (United States)

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

    2015-01-01

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

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

    Scientific Electronic Library Online (English)

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

    2011-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Alexandre Secorun Borges

    2003-06-01

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

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

    Scientific Electronic Library Online (English)

    Alexandre Secorun, Borges; José Luiz de Mello, Nicoletti; Armen, Thomassian; Ênio Pedone, Bandarra; Ana Laura, Angeli.

    2003-06-01

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

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

    Scientific Electronic Library Online (English)

    Marcelo Eiji Inoue, Yamamoto; Cristina Freitas, Ganança.

    2012-03-01

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

  10. 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 hearing preservation was also investigated.

  11. Determining Benchmarks in Hearing Preservation Surgery for Vestibular Schwannoma

    OpenAIRE

    Gluth, Michael B; DAY, JOHN D.; Dornhoffer, John L

    2012-01-01

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

  12. Doença vestibular periférica decorrente de osteoartropatia temporoioídea em um eqüino

    OpenAIRE

    Borges Alexandre Secorun; Nicoletti José Luiz de Mello; Thomassian Armen; Bandarra Ênio Pedone; Angeli Ana Laura

    2003-01-01

    Um eqüino com 22 anos de idade apresentou síndrome vestibular periférica associada à paralisia de nervo facial esquerdo devido à osteoartropatia temporoioídea. O exame endoscópico das bolsas guturais mostrou alteração de contorno da bula timpânica esquerda e aumento de volume da extremidade proximal do osso estiloióide do mesmo lado.

  13. 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.

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

    OpenAIRE

    Rinaldi, Vittorio; Casale, Manuele; Bressi, Federica; Potena, Massimiliano; Vesperini, Emanuela; 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...

  15. 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

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

    Science.gov (United States)

    Reynolds, Raymond F

    2011-08-15

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

  17. Incidence of vestibular schwannomas in the United States.

    Science.gov (United States)

    Kshettry, Varun R; Hsieh, Jason K; Ostrom, Quinn T; Kruchko, Carol; Barnholtz-Sloan, Jill S

    2015-09-01

    There is a paucity of population-based data evaluating the incidence of vestibular schwannomas according to age, gender, race, and ethnicity. Such data are necessary to assess the burden of vestibular schwannomas on varying populations and to inform future research and healthcare planning. The Central Brain Tumor Registry of the United States, which contains the largest aggregation of population-based data on the incidence of primary central nervous system tumors in the US, was used. Age-adjusted incidence rates and incidence rate ratios (IRR) of vestibular schwannomas from 2004 to 2010 were calculated by age at diagnosis, gender, race, and ethnicity. Annual percent change (APC) was calculated using Joinpoint to characterize temporal trends. From 2004 to 2010, there were 23,729 newly diagnosed vestibular schwannomas in the US; overall incidence was 1.09 per 100,000 population. Incidence was stable over time (APC -0.41 %, 95 % confidence interval -3.4, 2.7). Incidence increased with age to a peak of 2.93 per 100,000 in the 65-74 year old age group. Overall, there was no difference in incidence by gender. Compared to Whites, incidence was highest in Asian Pacific Islanders (IRR 1.37, p vestibular schwannomas are diagnosed per year in the US and incidence is 1.09 per 100,000 population. Incidence increases with age up to the 65-74 year old age group. Incidence is higher in Asian Pacific Islanders and lower in African Americans and Hispanics. PMID:26024654

  18. Reabilitação vestibular em pacientes com esclerose múltipla remitente-recorrente Vestibular rehabilitation in patients with relapsing- remitting multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Karina Pavan

    2007-06-01

    Full Text Available A esclerose múltipla (EM é doença desmielinizante, inflamatória, que acomete a substância branca do sistema nervoso central, e sensações vestibulares anormais (vertigem, desequilíbrio são freqüentes. A reabilitação vestibular (RV é determinada por mecanismos de adaptações, substituições e compensações neurais. Este estudo avaliou a melhora da vertigem central ou periférica em pacientes com EM remitente-recorrente submetidos à RV (exercícios de Cawthorne-Cooksey, através da escala de Berg e Dizziness Handicap Inventory (DHI. Nesta amostra de 4 casos a RV, realizada em um período de 2 meses, demonstrou a melhora em 3 pacientes avaliados pela escala de Berg e em 2 pacientes quando avaliados pela DHI.Multiple sclerosis (MS is a demyelinating, inflammatory illness, that attack the white matter of the central nervous system, and abnormal vestibular sensations (vertigo, disequilibrium are frequent. The vestibular rehabilitation (VR is determined by mechanisms of adaptations, neural substitutions and compensations. This study evaluated the improvement of the central or peripheral vertigo in patients with relapsing-remitting MS submitted to the VR (exercises of Cawthorne-Cooksey, through the scale of Berg and Dizziness Handicap Inventory (DHI. In this sample of 4 cases the VR, carried through in a period of 2 months, demonstrated the improvement in 3 patients according to the Berg scale and in 2 patients considering that of the DHI.

  19. Reabilitação vestibular em pacientes com esclerose múltipla remitente-recorrente / Vestibular rehabilitation in patients with relapsing- remitting multiple sclerosis

    Scientific Electronic Library Online (English)

    Karina, Pavan; Bruna E.M., Marangoni; Kizi B., Schmidt; Fernanda A., Cobe; Gabriela S., Matuti; Lúcia K., Nishino; Rodrigo B., Thomaz; Maria Fernanda, Mendes; Sérgio, Lianza; Charles Peter, Tilbery.

    2007-06-01

    Full Text Available A esclerose múltipla (EM) é doença desmielinizante, inflamatória, que acomete a substância branca do sistema nervoso central, e sensações vestibulares anormais (vertigem, desequilíbrio) são freqüentes. A reabilitação vestibular (RV) é determinada por mecanismos de adaptações, substituições e compens [...] ações neurais. Este estudo avaliou a melhora da vertigem central ou periférica em pacientes com EM remitente-recorrente submetidos à RV (exercícios de Cawthorne-Cooksey), através da escala de Berg e Dizziness Handicap Inventory (DHI). Nesta amostra de 4 casos a RV, realizada em um período de 2 meses, demonstrou a melhora em 3 pacientes avaliados pela escala de Berg e em 2 pacientes quando avaliados pela DHI. Abstract in english Multiple sclerosis (MS) is a demyelinating, inflammatory illness, that attack the white matter of the central nervous system, and abnormal vestibular sensations (vertigo, disequilibrium) are frequent. The vestibular rehabilitation (VR) is determined by mechanisms of adaptations, neural substitutions [...] and compensations. This study evaluated the improvement of the central or peripheral vertigo in patients with relapsing-remitting MS submitted to the VR (exercises of Cawthorne-Cooksey), through the scale of Berg and Dizziness Handicap Inventory (DHI). In this sample of 4 cases the VR, carried through in a period of 2 months, demonstrated the improvement in 3 patients according to the Berg scale and in 2 patients considering that of the DHI.

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

    Scientific Electronic Library Online (English)

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

    2005-02-01

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

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

    Scientific Electronic Library Online (English)

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

    2015-06-01

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

  2. Neuronal Migration Disorders

    Science.gov (United States)

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

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

    Scientific Electronic Library Online (English)

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

    2004-12-01

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

  4. 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.

  5. 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.

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

    Science.gov (United States)

    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 and head facing forward. Lateral forces under each foot and lateral displacement of the upper body of adolescents with mild (n = 20) or severe (n = 16) spine deformation were compared to those of healthy control adolescents (n = 16). Adolescent idiopathic scoliosis patients demonstrated greater lateral displacement and net lateral forces than controls both during and immediately after vestibular stimulation. Altered sensory reweighting of vestibular and proprioceptive information changed balance control of AIS patients during and after vestibular stimulation. Therefore, scoliosis onset could be related to abnormal sensory reweighting, leading to altered sensorimotor processes. PMID:26580068

  7. 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.

  8. 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.

  9. Neuronal plasticity in relation to long-duration spaceflight

    Science.gov (United States)

    Hillman, Dean E.; Wolfe, James W.

    1990-01-01

    Exposure to microgravity leads to a marked reduction in sensory-motor stimuli to the vestibular, proprioceptive and somatosensory systems. Long-duration missions, such as those proposed for a trip to Mars, may lead to significant changes in neural function. This paper presents results based on studies of sensory deafferentation of specific brain regions and detailed changes which occur in neuronal architecture. Data from these studies emphasize the need for further research related to sensory system deprivation and the development of new unique countermeasures for long-duration space flight.

  10. Electrical Vestibular Stimuli to Enhance Vestibulo-Motor Output and Improve Subject Comfort

    OpenAIRE

    Forbes, P.A.; Dakin, C.J.; Geers, A.M.; Vlaar, M.P.; Happee, R.; Siegmund, G.P.; A.C. Schouten; Blouin, J.S.

    2014-01-01

    Electrical vestibular stimulation is often used to assess vestibulo-motor and postural responses in both clinical and research settings. Stochastic vestibular stimulation (SVS) is a recently established technique with many advantages over its square-wave counterpart; however, the evoked muscle responses remain relatively small. Although the vestibular-evoked responses can be enhanced by increasing the stimulus amplitude, subjects often perceive these higher intensity electrical stimuli as nox...

  11. 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...

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

    DEFF Research Database (Denmark)

    Alsmith, Adrian John Tetteh

    2015-01-01

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

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

    OpenAIRE

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

    2003-01-01

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

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

    OpenAIRE

    Ekvall-Hansson, Eva; Beckman, Anders; Håkansson, Anders

    2010-01-01

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

  15. The vestibular implant: frequency-dependency of the electrically evoked vestibulo-ocular reflex in humans

    OpenAIRE

    van de Berg, Raymond; Guinand, Nils; Nguyen, T. A. Khoa; Ranieri, Maurizio; Cavuscens, Samuel; Guyot, Jean-Philippe; Stokroos, Robert; Kingma, Herman; Perez-Fornos, Angelica

    2015-01-01

    The vestibulo-ocular reflex (VOR) shows frequency-dependent behavior. This study investigated whether the characteristics of the electrically evoked VOR (eVOR) elicited by a vestibular implant, showed the same frequency-dependency. Twelve vestibular electrodes implanted in seven patients with bilateral vestibular hypofunction (BVH) were tested. Stimuli consisted of amplitude-modulated electrical stimulation with a sinusoidal profile at frequencies of 0.5, 1, and 2 Hz. The main characteristics...

  16. Spatial reference frames of visual, vestibular, and multimodal heading signals in area MSTd

    OpenAIRE

    Fetsch, Christopher R.; Wang, Sentao; Gu, Yong; DEANGELIS, GREGORY C.; Angelaki, Dora E.

    2007-01-01

    Heading perception is a complex task that generally requires the integration of visual and vestibular cues. This sensory integration is complicated by the fact that these two modalities encode motion in distinct spatial reference frames (visual: eye-centered; vestibular: head-centered). Visual and vestibular heading signals converge in primate area MSTd, a region thought to contribute to heading perception, but the reference frames of these signals remain unknown. We measured the heading tuni...

  17. 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...

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

    OpenAIRE

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

    2008-01-01

    This study evaluated the electromyographic characteristics of masticatory and neck muscles in subjects with vestibular lesions. Surface electromyography of the masseter, temporalis and sternocleidomastoid muscles was performed in 19 patients with Ménière's disease, 12 patients with an acute peripheral vestibular lesion, and 19 control subjects matched for sex and age. During maximum voluntary clenching, patients with peripheral vestibular lesions had the highest co-contraction of the sternocl...

  19. 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.

  20. Vestibular nuclei characterized by calcium-binding protein immunoreactivity and tract tracing in Gekko gecko

    OpenAIRE

    Song, Jing; WANG, WENBO; Carr, Catherine E; Dai, Zhendong; Tang, Yezhong

    2012-01-01

    Immunohistochemical techniques were used to describe the distribution of the calcium binding proteins calretinin, calbindin and parvalbumin as well as synaptic vesicle protein 2 in the vestibular nuclei of the Tokay gecko (Gekko gecko). In addition, tract tracing was used to investigate connections between the vestibular nerves and brainstem nuclei. Seven vestibular nuclei were recognized: the nuclei cerebellaris lateralis (Cerl), vestibularis dorsolateralis (Vedl), ventrolateralis (Vevl), ve...

  1. 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...

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

    OpenAIRE

    Van Cleave, S; Shall, M.S.

    2006-01-01

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

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

    Science.gov (United States)

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

    2015-01-01

    Sensorimotor changes such as postural and gait instabilities can affect the functional performance of astronauts when they transition across different gravity environments. We are developing a method, based on stochastic resonance (SR), to enhance information transfer by applying non-zero levels of external noise on the vestibular system (vestibular stochastic resonance, VSR). The goal of this project was to determine optimal levels of stimulation for SR applications by using a defined vestibular threshold of motion detection.

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Jocelyne Ventre-Dominey

    2014-07-01

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

  6. 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.

  7. Research on biophysical evaluation of the human vestibular system

    Science.gov (United States)

    Young, L. R.

    1974-01-01

    The human vestibular function was studied by the combined approach of advanced measurement and mathematical modelling. Fundamental measurements of some physical properties of endolymph and perilymph, combined with nystagmus measurements and fluid mechanical analysis of semicircular canal function furthered the theory of canal mechanical response to angular acceleration, caloric stimulation and relating linear acceleration. The effects of adaptation seen at low frequency angular stimulation were studied and modelled to remove some shortcomings of the torsion pendulum models. Otolith function was also studied experimentally and analytically, leading to a new set of models for subjective orientation. Applications to special problems of space, including the case of rotating spacecraft were investigated and the interaction of visual and vestibular cues and their relation to proprioceptive information was explored relative to postural control.

  8. Current treatment strategy in the management of vestibular schwannoma

    OpenAIRE

    Misra Basant; Purandare Harshad; Ved Rahul; Bagdia Anshul; Mare Pandurang

    2009-01-01

    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 microsur...

  9. Magnetic Vestibular Stimulation in Subjects with Unilateral Labyrinthine Disorders

    OpenAIRE

    BryanKevinWard; DaleCRoberts; CharlesCDella Santina; DavidSZee

    2014-01-01

    We recently discovered that static magnetic fields from high-strength MRI machines induce nystagmus in all normal humans, and that a magneto-hydrodynamic 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 deficits in labyrinthine function is unknown and may provide insight into the mech...

  10. 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...

  11. 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.

  12. Galvanic Vestibular Stimulation in Hemi-Spatial Neglect

    Directory of Open Access Journals (Sweden)

    David Wilkinson

    2014-01-01

    Full Text Available Hemi-spatial neglect is an attentional disorder in which the sufferer fails to acknowledge or respond to stimuli appearing in contralesional space. In recent years, it has become clear that a measurable reduction in contralesional neglect can occur during galvanic vestibular stimulation, a technique by which transmastoid, small amplitude current induces lateral, attentional shifts via asymmetric modulation of the left and right vestibular nerves. However, it remains unclear whether this reduction persists after stimulation is stopped. To estimate longevity of effect, we therefore conducted a double-blind, randomized, dose-response trial involving a group of stroke patients suffering from left-sided neglect (n=52, mean age=66 years. To determine whether repeated sessions of galvanic vestibular stimulation more effectively induce lasting relief than a single session, participants received 1, 5, or 10 sessions, each lasting 25mins, of sub-sensory, left-anodal right-cathodal noisy direct current (mean amplitude=1mA. Ninety five percent confidence intervals indicated that all three treatment arms showed a statistically significant improvement between the pre-stimulation baseline and the final day of stimulation on the primary outcome measure, the conventional tests of the Behavioural Inattention Test. More remarkably, this change (mean change=28%, SD=18 was still evident 1month later. Secondary analyses indicated an allied increase of 20% in median Barthel Index score, a measure of functional capacity, in the absence of any adverse events or instances of participant non-compliance. Together these data suggest that galvanic vestibular stimulation, a simple, cheap technique suitable for home-based administration, may produce lasting reductions in neglect that are clinically important. Further protocol optimization is now needed ahead of a larger effectiveness study.

  13. Leptomeningeal Carcinomatosis of Gastric Cancer Misdiagnosed as Vestibular Schwannoma

    OpenAIRE

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

    2014-01-01

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

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

    OpenAIRE

    Zhang Yang; Yu Jinlu; Qu Limei; Li Yunqian

    2012-01-01

    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). T...

  15. 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 35 308 974 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 sociodemograp...

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

    OpenAIRE

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

    2012-01-01

    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, ...

  17. 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 areas of Denmark and whether a change has occurred during the period 1976-2012. In addition, differences in diagnostic age and tumor size between areas were explored. METHODS: Since 1976, all...

  18. 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...

  19. The sensitivity of an immature vestibular system to altered gravity.

    Science.gov (United States)

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

    2012-07-01

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

  20. Fundus Obliteration and Facial Nerve Outcome in Vestibular Schwannoma Surgery

    OpenAIRE

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

    2011-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Scientific Electronic Library Online (English)

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

    2011-06-01

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

  3. 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.

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    1993-01-01

    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-acetylglucosamine (WGA), 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 strain 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 I hair cells while labeling, as in the bullfrog, Type II 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.

  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. Multiple intracranial lipomas, hypogenetic corpus callosum and vestibular schwannoma: an unusual spectrum of MR findings in a patient.

    OpenAIRE

    Shah J; Srinivasa P; Gala B; Patkar D; Patankar T; Kale H

    1999-01-01

    We describe imaging findings of a patient with multiple intracranial lipomas, hypogenetic corpus callosum and a vestibular schwannoma. We did not find association of intracranial lipomas and vestibular schwannoma in English literature.

  8. Multiple intracranial lipomas, hypogenetic corpus callosum and vestibular schwannoma: an unusual spectrum of MR findings in a patient.

    Directory of Open Access Journals (Sweden)

    Shah J

    1999-04-01

    Full Text Available We describe imaging findings of a patient with multiple intracranial lipomas, hypogenetic corpus callosum and a vestibular schwannoma. We did not find association of intracranial lipomas and vestibular schwannoma in English literature.

  9. [Interdisciplinary approach to vestibular system impairment].

    Science.gov (United States)

    Pongrácz, Endre

    2011-03-30

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

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

    Scientific Electronic Library Online (English)

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

    2003-08-01

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

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

    Scientific Electronic Library Online (English)

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

    2013-08-01

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

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

    Science.gov (United States)

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

    2011-04-01

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

  13. 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.

  14. 7-Tesla MRI demonstrates absence of structural lesions in patients with vestibular paroxysmia

    Directory of Open Access Journals (Sweden)

    Paulus Stefan Rommer

    2015-06-01

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

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

    OpenAIRE

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

    2009-01-01

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

  16. Temporal bone studies of the human peripheral vestibular system. Aminoglycoside ototoxicity.

    Science.gov (United States)

    Tsuji, K; Velázquez-Villaseñor, L; Rauch, S D; Glynn, R J; Wall, C; Merchant, S N

    2000-05-01

    Quantitative assessments of vestibular hair cells and Scarpa's ganglion cells were performed on 17 temporal bones from 10 individuals who had well-documented clinical evidence of aminoglycoside ototoxicity (streptomycin, kanamycin, and neomycin). Assessment of vestibular hair cells was performed by Nomarski (differential interference contrast) microscopy. Hair cell counts were expressed as densities (number of cells per 0.01 mm2 surface area of the sensory epithelium). The results were compared with age-matched normal data. Streptomycin caused a significant loss of both type I and type II hair cells in all 5 vestibular sense organs. In comparing the ototoxic effect on type I versus type II hair cells, there was greater type I hair cell loss for all 3 cristae, but not for the maculae. The vestibular ototoxic effects of kanamycin appeared to be similar to those of streptomycin, but the small sample size precluded definitive conclusions from being made. Neomycin did not cause loss of vestibular hair cells. Within the limits of this study (maximum postototoxicity survival time of 12 months), there was no significant loss of Scarpa's ganglion cells for any of the 3 drugs. The findings have implications in several clinical areas, including the correlation of vestibular test results to pathological findings, the rehabilitation of patients with vestibular ototoxicity, the use of aminoglycosides to treat Meniere's disease, and the development of a vestibular prosthesis. PMID:10821231

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

    Science.gov (United States)

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

    1999-02-01

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

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

    Scientific Electronic Library Online (English)

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

    2008-12-01

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

  19. Nonlinear high-order mode locking in stochastic sensory neurons

    Science.gov (United States)

    Rowe, Michael; Afghan, Muhammad; Neiman, Alexander

    2004-03-01

    Excitable systems demonstrate various mode locking regimes when driven by periodic external signals. With noise taken into account, such regimes represent complex nonlinear responses which depend crucially on the frequency and amplitude of the periodic drive as well as on the noise intensity. We study this using a computational model of a stochastic Hodgkin-Huxley neuron in combination with the turtle vestibular sensory system as an experimental model. A bifurcation analysis of the model is performed. Extracellular recordings from primary vestibular afferent neurons with two types of stimuli are used in the experimental study. First, mechanical stimuli applied to the labyrinth allow us to study the responses of the entire system, including transduction by the hair cells and spike generation in the primary afferents. Second, a galvanic stimuli applied directly to an afferent are used to study the responses of afferent spike generator directly. The responses to galvanic stimuli reveal multiple high-order mode locking regimes which are well reproduced in numerical simulation. Responses to mechanical stimulation are characterized by larger variability so that fewer mode-locking regimes can be observed.

  20. Changes in clinical and instrumental vestibular parameters following acute exposition to auditory stress.

    Science.gov (United States)

    Cassandro, E; Chiarella, G; Catalano, M; Gallo, L V; Marcelli, V; Nicastri, M; Petrolo, C

    2003-08-01

    Besides Tullio's phenomenon, resulting from anatomic changes in the labyrinth, a hypersensitivity to acoustic stimuli of the saccular structures appears to be the underlying cause of the vestibular responses detected in some patients. In order to evaluate the incidence of vestibular symptoms triggered by acute exposure to auditory stress (disco music), 40 subjects aged between 18 and 26 years, with no audiological and vestibular disorders, were submitted to otoneurologic tests. Subjects were exposed to disco music [intensity 128 dB (C)], for 3 hours. Tests have been carried out before and immediately after exposure. Canalar and macular functions have been evaluated using vestibular investigation techniques and vestibular evoked myogenic potentials. When compared to baseline data, post-exposure test results did not reveal any canalar damage. Pre- and post-exposure recordings of the vestibular-oculomotor reflex threshold have shown no significant changes. Conversely, post-stimulus recordings have shown a significant increase in the amplitude of the vestibular evoked myogenic potential response, thus indicating a possible irritative involvement of the macular receptor. This result suggests a direct action upon the receptor by acoustic stimulation which could, therefore, be the underlying cause of vestibular symptoms reported by patients following exposure to sufficiently intense acoustic stimuli. Prior to this study. a questionnaire concerning the relationship between habitual disco visiting and audio-vestibular symptoms has been completed by 310 students at the University of Catanzaro. This survey revealed a significant incidence of vestibular symptoms due to acoustic stress (Tullio's phenomenon) which led us to hypothesise that balance disorders due to auditory stress are much more frequent than commonly held, particularly since, in many cases, diagnoses is unknown or not easy due to the difficult procedures by which these conditions are diagnosed. PMID:15046413

  1. Effects of vestibular loss on head stabilization in response to head and body perturbations

    Science.gov (United States)

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

    1996-01-01

    Control of head position during postural responses is important to facilitate both the interpretation of vestibular signals and the stabilization of gaze. In these experiments, we compared head stabilization for two different postural tasks: 1) in response to perturbations at the head, and 2) in response to perturbations induced at the support surface, which perturb both body and head position. To determine whether normal vestibular function is necessary for head stabilization in these two tasks, responses to forward and backward mechanical perturbations of the head and body were compared for 13 normal subjects and 4 patients with profound bilateral vestibular loss (two with vestibular loss in adulthood and two in infancy). Normal subjects showed little neck muscle activity for body perturbations, but large, early activations in both neck extensors and flexors for head perturbations. In contrast, vestibular patients showed excessive neck muscle activation for body perturbations and reduced or absent neck muscle activity for head perturbations. Patients with vestibular loss in adulthood also showed increased head acceleration in response to both head and body perturbations, but patients with vestibular loss in infancy showed more normal head accelerations. For body perturbations, the differences in head acceleration between patients and normals were greater for later head acceleration peaks, indicating poor head control during the execution of the postural response. Trunk angle changes were also higher in the patients for forward body perturbations, indicating that poorer control of trunk position could have contributed to their poorer head stabilization. These results indicate that the vestibular system plays an important role in head and trunk stabilization for both head and body perturbations. However, the more normal head accelerations of the patients with infant vestibular loss also indicate that other mechanisms, possibly involving neck reflexes, can at least partially substitute for the vestibular system to provide head and trunk stabilization.

  2. Development and Function of the Mouse Vestibular System in the Absence of Gravity Perception

    Science.gov (United States)

    Wolgemuth, Debra J.

    2005-01-01

    The hypothesis that was tested in this research was that the absence of gravity perception, such as would occur in space, would affect the development and function of the vestibular and central nervous systems. Further, we postulated that these effects would be more significant at specific stages of post-natal development of the animal. We also proposed the use of molecular genetic approaches that would provide important information as to the hierarchy of gene function during the development and subsequent function of the vestibular system. The tilted (tlt) mutant mouse has been characterized as lacking the ability to provide sensory input to the gravity receptors. The tlt/tlt mutant mice were a particularly attractive model for the study of vestibular function since the primary defect was limited to the receptor part of the vestibular system, and there were no detectable abnormal phenotypes in other organ systems. The goal of the proposed studies was to assess immediate and delayed effects of the lack of gravity perception on the vestibular system. Particular attention was paid to characterizing primarily affected periods of vestibular morphogenesis, and to identifying downstream genetic pathways that are altered in the CNS of the tlt/tlt mutant mouse. The specific aims were: (1) to characterize the postnatal morphogenesis of the CNS in the tlt mutant mouse, using detailed morphometric analysis of isolated vestibular ganglia and brain tissue at different stages of postnatal development and assessment of apoptotic cell death; (2) to examine the expression of selected genes implicated by mutational analysis to be important in vestibular development or function by in situ hybridization or immunohistochemistry in the mutant mice; and (3) to identify other genes involved in vestibular development and function, using differential cloning strategies to isolate genes whose expression is changed in the mutant versus normal vestibular system.

  3. Yaw and pitch visual-vestibular interaction in weightlessness

    Science.gov (United States)

    Clement, G.; Wood, S. J.; Reschke, M. F.; Berthoz, A.; Igarashi, M.

    1999-01-01

    Both yaw and pitch visual-vestibular interactions at two separate frequencies of chair rotation (0.2 and 0.8 Hz) in combination with a single velocity of optokinetic stimulus (36 degrees/s) were used to investigate the effects of sustained weightlessness on neural strategies adopted by astronaut subjects to cope with the stimulus rearrangement of spaceflight. Pitch and yaw oscillation in darkness at 0.2 and 0.8 Hz without optokinetic stimulation, and constant velocity linear optokinetic stimulation at 18, 36, and 54 degrees/s presented relative to the head with the subject stationary, were used as controls for the visual-vestibular interactions. The results following 8 days of space flight showed no significant changes in: (1) either the horizontal and vertical vestibulo-ocular reflex (VOR) gain, phase, or bias; (2) the yaw visual-vestibular response (VVR); or (3) the horizontal or vertical optokinetic (OKN) slow phase velocity (SPV). However, significant changes were observed: (1) when during pitch VVR at 0.2 Hz late inflight, the contribution of the optokinetic input to the combined oculomotor response was smaller than during the stationary OKN SPV measurements, followed by an increased contribution during the immediate postflight testing; and (2) when during pitch VVR at 0.8 Hz, the component of the combined oculomotor response due to the underlying vertical VOR was more efficiently suppressed early inflight and less suppressed immediately postflight compared with preflight observations. The larger OKN response during pitch VVR at 0.2 Hz and the better suppression of VOR during pitch VVR at 0.8 Hz postflight are presumably due to the increased role of vision early inflight and immediately after spaceflight, as previously observed in various studies. These results suggest that the subjects adopted a neural strategy to structure their spatial orientation in weightlessness by reweighting visual, otolith, and perhaps tactile/somatic signals.

  4. 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.

  5. 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 localization and the size of the tumour. The size of the tumour was registered as either intrameatal or with the largest extrameatal diameter. The annual number of diagnosed VS has increased from 26 in 1976 ...

  6. 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.

  7. diferenciación neuronal

    Directory of Open Access Journals (Sweden)

    Gabriel Moreno González

    2006-01-01

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

  8. Virtual labyrinth model of vestibular afferent excitation via implanted electrodes: validation and application to design of a multichannel vestibular prosthesis.

    Science.gov (United States)

    Hayden, Russell; Sawyer, Stacia; Frey, Eric; Mori, Susumu; Migliaccio, Americo A; Della Santina, Charles C

    2011-05-01

    To facilitate design of a multichannel vestibular prosthesis that can restore sensation to individuals with bilateral loss of vestibular hair cell function, we created a virtual labyrinth model. Model geometry was generated through 3-dimensional (3D) reconstruction of microMRI and microCT scans of normal chinchillas (Chinchilla lanigera) acquired with 30-48 ?m and 12 ?m voxels, respectively. Virtual electrodes were positioned based on anatomic landmarks, and the extracellular potential field during a current pulse was computed using finite element methods. Potential fields then served as inputs to stochastic, nonlinear dynamic models for each of 2,415 vestibular afferent axons with spiking dynamics based on a modified Smith and Goldberg model incorporating parameters that varied with fiber location in the neuroepithelium. Action potential propagation was implemented by a well validated model of myelinated fibers. We tested the model by comparing predicted and actual 3D angular vestibulo-ocular reflex (aVOR) axes of eye rotation elicited by prosthetic stimuli. Actual responses were measured using 3D video-oculography. The model was individualized for each animal by placing virtual electrodes based on microCT localization of real electrodes. 3D eye rotation axes were predicted from the relative proportion of model axons excited within each of the three ampullary nerves. Multiple features observed empirically were observed as emergent properties of the model, including effects of active and return electrode position, stimulus amplitude and pulse waveform shape on target fiber recruitment and stimulation selectivity. The modeling procedure is partially automated and can be readily adapted to other species, including humans. PMID:21380738

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

    Scientific Electronic Library Online (English)

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

    2005-02-01

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

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

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    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.

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

    Scientific Electronic Library Online (English)

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

    2009-11-01

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

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

    Directory of Open Access Journals (Sweden)

    Heraldo Lorena Guida

    2007-09-01

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

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

    Scientific Electronic Library Online (English)

    Heraldo Lorena, Guida; Neivo Luiz, Zorzetto.

    2007-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Héctor Riveros

    2007-12-01

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

  15. Synaptic diversity enables temporal coding of coincident multisensory inputs in single neurons.

    Science.gov (United States)

    Chabrol, François P; Arenz, Alexander; Wiechert, Martin T; Margrie, Troy W; DiGregorio, David A

    2015-05-01

    The ability of the brain to rapidly process information from multiple pathways is critical for reliable execution of complex sensory-motor behaviors, yet the cellular mechanisms underlying a neuronal representation of multimodal stimuli are poorly understood. Here we explored the possibility that the physiological diversity of mossy fiber (MF) to granule cell (GC) synapses in the mouse vestibulocerebellum may contribute to the processing of coincident multisensory information at the level of individual GCs. We found that the strength and short-term dynamics of individual MF-GC synapses can act as biophysical signatures for primary vestibular, secondary vestibular and visual input pathways. Most GCs receive inputs from different modalities, which, when coactivated, produced enhanced GC firing rates and distinct first spike latencies. Thus, pathway-specific synaptic response properties permit temporal coding of correlated multisensory inputs by single GCs, thereby enriching sensory representation and facilitating pattern separation. PMID:25821914

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

    Directory of Open Access Journals (Sweden)

    Fred Henry Previc

    2014-06-01

    Full Text Available Research during the past two decades has demonstrated an important role of the vestibular system in topographical orientation and memory and the network of neural structures associated with them. Almost all of the supporting data have come from animal or human clinical studies, however. The purpose of the present study was to investigate the link between vestibular function and topographical memory in normal elderly humans. Twenty-five participants aged 70 to 85 years who scored from mildly impaired to normal on the Montreal Cognitive Assessment received three topographical memory tests: the Camden Topographical Recognition Memory Test (CTMRT, a computerized topographical mental rotation test (TMRT, and a virtual pond maze (VPM. They also received six vestibular or oculomotor tests: optokinetic nystagmus (OKN, visual pursuit (VP, actively generated vestibulo-ocular reflex (VOR, the sensory orientation test (SOT for posture, and two measures of rotational memory (error in degrees, or RMº, and correct directional recognition, or RM?. The only significant bivariate correlations were among the three vestibular measures primarily assessing horizontal canal function (VOR, RMº, and RM?. A multiple regression analysis showed significant relationships between vestibular and demographic predictors and both the TMRT (R=.78 and VPM (R=.66 measures. The significant relationship between the vestibular and topographical memory measures supports the theory that vestibular loss may contribute to topographical memory impairment in the elderly.

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

    Science.gov (United States)

    Chetana, Naik; Jayesh, Rane

    2015-06-01

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

  18. 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.

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

    Science.gov (United States)

    Marcelli, Vincenzo; Esposito, Fabrizio; Aragri, Adriana; Furia, Teresa; Riccardi, Pasquale; Tosetti, Michela; Biagi, Laura; Marciano, Elio; Di Salle, Francesco

    2009-05-01

    Processing of vestibular information at the cortical and subcortical level is essential for head and body orientation in space and self-motion perception, but little is known about the neural dynamics of the brain regions of the vestibular system involved in this task. Neuroimaging studies using both galvanic and caloric stimulation have shown that several distinct cortical and subcortical structures can be activated during vestibular information processing. The insular cortex has been often targeted and presented as the central hub of the vestibular cortical system. Since very short pulses of cold water ear irrigation can generate a strong and prolonged vestibular response and a nystagmus, we explored the effects of this type of caloric stimulation for assessing the blood-oxygen-level-dependent (BOLD) dynamics of neural vestibular processing in a whole-brain event-related functional magnetic resonance imaging (fMRI) experiment. We evaluated the spatial layout and the temporal dynamics of the activated cortical and subcortical regions in time-locking with the instant of injection and were able to extract a robust pattern of neural activity involving the contra-lateral insular cortex, the thalamus, the brainstem and the cerebellum. No significant correlation with the temporal envelope of the nystagmus was found. The temporal analysis of the activation profiles highlighted a significantly longer duration of the evoked BOLD activity in the brainstem compared to the insular cortex suggesting a functional de-coupling between cortical and subcortical activity during the vestibular response. PMID:18342473

  20. 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.

  1. Vestibular nuclei characterized by calcium-binding protein immunoreactivity and tract tracing in Gekko gecko.

    Science.gov (United States)

    Song, Jing; Wang, Wenbo; Carr, Catherine E; Dai, Zhendong; Tang, Yezhong

    2013-02-01

    Immunohistochemical techniques were used to describe the distribution of the calcium binding proteins calretinin, calbindin and parvalbumin as well as synaptic vesicle protein 2 in the vestibular nuclei of the Tokay gecko (Gekko gecko). In addition, tract tracing was used to investigate connections between the vestibular nerves and brainstem nuclei. Seven vestibular nuclei were recognized: the nuclei cerebellaris lateralis (Cerl), vestibularis dorsolateralis (Vedl), ventrolateralis (Vevl), ventromedialis (Vevm), tangentialis (Vetg), ovalis (VeO) and descendens (Veds). Vestibular fibers entered the brainstem with the ascending branch projecting to Vedl and Cerl, the lateral descending branch to Veds, and the medial descending branch to ipsilateral Vevl. Cerl lay most rostral, in the cerebellar peduncle. Vedl, located rostrally, was ventral to the cerebellar peduncle, and consisted of loosely arranged multipolar and monopolar cells. Vevl was found at the level of the vestibular nerve root and contained conspicuously large cells and medium-sized cells. Veds is a large nucleus, the most rostral portion of which is situated lateral and ventral to Vevl, and occupies much of the dorsal brainstem extending caudally through the medulla. VeO is a spherically shaped cell group lateral to the auditory nucleus magnocellularis and dorsal to the caudal part of Vevl. Vevm and Vetg were small in the present study. Except for VeO, all other vestibular nuclei appear directly comparable to counterparts in other reptiles and birds based on their location, cytoarchitecture, and connections, indicating these are conserved features of the vestibular system. PMID:23201031

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

    Science.gov (United States)

    Shah, Kushal J; Chamoun, Roukoz B

    2014-06-01

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

  3. Immersive virtual environment for visuo-vestibular therapy: preliminary results.

    Science.gov (United States)

    Gascuel, J D; Payno, H; Schmerber, S; Martin, O

    2012-01-01

    The sense of equilibrium aggregates several interacting cues. On vestibular areflexic patients, vision plays a major role. We developed an immersive therapeutic platform, based on 3D opto-kinetic stimulation that enables to tune the difficulty of the balance task by managing the type of optic flow and its speed. The balance adjustments are recorded by a force plate, quantified by the length of the center of pressure trajectory and detection of disequilibrium corrections (leans, compensation step). Preliminary analysis shows that (i) patients report a strong immersion feeling in the motion flow, triggering intense motor response to "fight against fall"; (ii) the ANOVA factorial design shows a significant effect of flow speed, session number and gaze anchor impact. In conclusion, this study shows that 3D immersive stimulation removes essential limits of traditional opto-kinetic stimulators (limited 2D motions and remaining fixed background cues). Moreover, the immersive optic flow stimulation is an efficient tool to induce balance adaptive reactions in vestibular patients. Hence, such a platform appears to be a powerful therapeutic tool for training and relearning of balance control processes. PMID:22954853

  4. Prevalence of hydrocephalus in 157 patients with vestibular schwannoma

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-05-01

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

  5. 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.)

  6. Pathogenesis of vestibular schwannoma in ring chromosome 22

    Directory of Open Access Journals (Sweden)

    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.

  7. Horizontal VOR function shows frequency dynamics in vestibular schwannoma.

    Science.gov (United States)

    Blödow, Alexander; Blödow, Julia; Bloching, Marc Boris; Helbig, Ralf; Walther, Leif Erik

    2015-09-01

    The objective of this retrospective study was to investigate the horizontal vestibulo-ocular reflex (hVOR) pathway with caloric test (low-frequency hVOR) and video head impulse test (vHIT) (high-frequency hVOR) in patients with sporadic vestibular schwannoma (69 patients, 27-86 years, mean age 58.1 years) and to compare both test methods in terms of their sensitivity and specificity to detect a retrocochlear lesion. Test results with a unilateral weakness (UWCaloric) >25 % (caloric test) or a Mean-GainvHIT 8.5 % and accompanied refixation saccades (vHIT) were considered abnormal. The overall sensitivity of the caloric test was 72 %. The evaluation of AR-GainvHIT detected more abnormal cases than did Mean-GainvHIT (44 vs. 36 %). In up to 4 %, a normal caloric test result was related to an abnormal vHIT. There was only a moderate correlation of UWCaloric and AR-GainvHIT (r = 0.54, p Vestibular testing at varying frequencies provides deeper insights into hVOR function and is helpful in detecting a cerebello-pontine lesion. Whereas caloric test yields a high sensitivity for nerve dysfunction, vHIT test reveals a remaining function of hVOR in the high-frequency range. PMID:24789061

  8. Improving Sensorimotor Function and Adaptation using Stochastic Vestibular Stimulation

    Science.gov (United States)

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

    2014-01-01

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

  9. Discapacidad por enfermedad auditiva y vestibular en un centro de atención especializada / Disability due to auditory and vestibular dysfunction in a specialized care center

    Scientific Electronic Library Online (English)

    Aralia, Gutiérrez-Márquez; Kathrine, Jáuregui-Renaud; Leticia, Viveros-Renteria; Laura Alejandra, Villanueva-Padrón.

    2005-04-01

    Full Text Available Objetivo: identificar la limitación que en su vida diaria padecen los pacientes evaluados por hipoacusia o enfermedad vestibular en un Centro de Atención Especializada del IMSS. Método: participaron 530 pacientes evaluados por primera vez con hipoacusia (n=252) o enfermedad vestibular (n=278), de lo [...] s cuales eran económicamente activos 54 y 50% respectivamente. Después de la evaluación especializada y de la administración un cuestionario de síntomas co cleovestibulares, se identificó la frecuencia y número de días de discapacidad relacionados con la hipoacusia o enfermedad vestibular y la frecuencia de consultas médicas durante el último año. Resultados: los pacientes con hipoacusia solicitaron consulta médica 1-6 veces/año y 15.8% informaron discapacidad. Mientras que aquéllos con enfermedad vestibular solicitaron 1-8 consultas e informaron discapacidad con más frecuencia (60.8%) (p Abstract in english Objective: To assess the frequency and characteristics of the disability associated with hearing loss and vestibular disease in a Specialized Medical Center of the Mexican Social Security Institute. Methods: 530 patients agreed to participate. They were assessed due to hearing loss (n=252) and vesti [...] bular disease (n=278), 54% and 50% of them worked. After a clinical evaluation and administration of a symptom questionnaire, they were asked about the frequency and days of disability to perform daily life activities related to their audiological or vestibular disease and how often they visited the physician during the last year because of their symptoms. Results: Hearing loss patients visited the physician 1-6 times/ year and 15.8% reported disability. Vestibular patients visited the physician 1-8 times/ year and reported disability more frequently (60.8%) (p

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

    Science.gov (United States)

    Enkhjargal, Nyamdavaa; Matsumoto, Jumpei; Chinzorig, Choijiljav; Berthoz, Alain; Ono, Taketoshi; Nishijo, Hisao

    2014-01-01

    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 two 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. PMID:25100955

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

    Science.gov (United States)

    Curthoys, I S; Grant, J W

    2015-03-01

    The mechanism by which vestibular neural phase locking occurs and how it relates to classical otolith mechanics is unclear. Here, we put forward the hypothesis that sound and vibration both cause fluid pressure waves in the inner ear and that it is these pressure waves which displace the hair bundles on vestibular receptor hair cells and result in activation of type I receptor hair cells and phase locking of the action potentials in the irregular vestibular afferents, which synapse on type I receptors. This idea has been suggested since the early neural recordings and recent results give it greater credibility. PMID:25567092

  12. 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.

  13. [T-lymphocyte subpopulation and HLA-DR antigens in hearing loss of vestibular neuropathy, Ménière's diseases and Bell's palsy].

    Science.gov (United States)

    Bumm, P; Müller, E C; Grimm-Müller, U; Schlimok, G

    1991-05-01

    In patients with various otoneurological diseases like hearing loss, neuronitis vestibularis, Ménière's disease and Bell's palsy, analyses concerning the immunoregulation and immunogenetics were done. For analysing the immunoregulation the T-helper (CD4) T-suppressor (CD8) ratio was determined. In contrast to patients with hearing loss caused by otobasal fractures and a healty control group, this ratio was elevated in 50% of the patients suffering from hearing loss. The elevation of the CD4/CD8 ratio was mainly caused by a reduction of CD8 positive cytotoxic-suppressor T-lymphocytes. The CD4/CD8 ratio may be of prognostic value, since an elevated ratio was found more often in patients with relapse of hearing loss, fluctuations, persistence of tinnitus or vestibular symptoms. An elevated ratio could also be detected in 48% of the patients with neuronitis vestibularis, in 50% of the patients with Ménière's disease and in 39% of the patients with Bell's palsy. A normal value was found in paralysis of the facial nerve of known origin like a state after trauma or after herpes zoster oticus paralysis. Immunogenetics was tested by HLA-DR typing. In patients with hearing loss HLA-DR4 antigen was distinctly increased, the relative risk was 2.8. The presence of the HLA-DR4 antigen proved to be an unfavourable sign, since in 44% of the patients presenting these antigens we found no improvement of the hearing. In patients with neuronitis vestibularis we found a relative risk of 3.12 and in patients with Ménière's disease a relative risk of 3.64, both for HLA-DR4.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2064703

  14. Avaliação vestibular por videonistagmografia de portadores de deficiência crônica de zinco por síndrome do intestino curto Vestibular evaluation using videonystagmography of chronic zinc deficient patients due to short bowell syndrome

    Directory of Open Access Journals (Sweden)

    Gustavo Duarte Paiva Ferreira

    2009-04-01

    Full Text Available A presença do elemento químico zinco na via auditiva e a sua provável participação na gênese de alguns tipos de disacusia estão bem documentadas, porém não há estudos funcionais que mostrem os impacto da deficiência sistêmica de zinco no sistema vestibular, nem estudos anatômicos descritivos comprovando a existência do íon nas estruturas da via vestibular. OBJETIVO: Este estudo foi realizado com o objetivo de relacionar a alteração na homeostase do zinco com anormalidades do funcionamento da via vestibular. MATERIAL E MÉTODOS: Este é um estudo de casos, retrospectivo, clínico, onde nove indivíduos portadores de deficiência crônica de zinco, entre outros distúrbios nutricionais, consequentes à síndrome de má absorção, foram submetidos à avaliação vestibular. Os resultados deste grupo foram comparados com os resultados de um grupo considerado normal do ponto de vista nutricional (grupo controle. RESULTADOS: Todos os parâmetros da análise vestibular do grupo experimental mostraram-se alterados em comparação com o grupo controle. CONCLUSÃO: A comparação entre os grupos mostrou diferenças significativas em diversos parâmetros da análise vestibular e chamou a atenção para uma possível participação das alterações disabsortivas na origem das desordens vestibulares.The presence of zinc in the auditory pathways and its probable participation in tinnitus and hearing loss are known facts, although there are no clinical trials and experimental studies showing the impact of hypozincemia in the vestibular system and zinc existence in the vestibular pathway, respectively. AIM: This study is an attempt to correlate hypozincemia and abnormal vestibular function. METHODS: This is a clinical retrospective case study where nine patients suffering of chronic zinc deficiency had their serum zinc determined and were submitted to videonystagmography. Results were compared to a normal (control group. RESULTS: All vestibular test parameters were altered when we compared experimental and control groups. CONCLUSION: Comparison between groups shows significant differences in many aspects of the vestibular analysis and calls our attention towards a possible participation of zinc on the genesis of vestibular disorders.

  15. 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)

  16. 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.

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

    Scientific Electronic Library Online (English)

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

    2005-02-01

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

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

    Scientific Electronic Library Online (English)

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

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

  19. 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.

  20. 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.

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

    Directory of Open Access Journals (Sweden)

    J.S. Sarkissian

    2010-03-01

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

  2. Vestibular inputs elicit patterned changes in limb blood flow in conscious cats.

    Science.gov (United States)

    Wilson, T D; Cotter, L A; Draper, J A; Misra, S P; Rice, C D; Cass, S P; Yates, B J

    2006-09-01

    Previous experiments have demonstrated that the vestibular system contributes to regulating sympathetic nervous system activity, particularly the discharges of vasoconstrictor fibres. In the present study, we examined the physiological significance of vestibulosympathetic responses by comparing blood flow and vascular resistance in the forelimb and hindlimb during head-up tilt from the prone position before and after the removal of vestibular inputs through a bilateral vestibular neurectomy. Experiments were performed on conscious cats that were trained to remain sedentary on a tilt table during rotations up to 60 deg in amplitude. Blood flow through the femoral and brachial arteries was recorded during whole-body tilt using perivascular probes; blood pressure was recorded using a telemetry system and vascular resistance was calculated from blood pressure and blood flow measurements. In vestibular-intact animals, 60 deg head-up tilt produced approximately 20% decrease in femoral blood flow and approximately 37% increase in femoral vascular resistance relative to baseline levels before tilt; similar effects were also observed for the brachial artery ( approximately 25% decrease in blood flow and approximately 38% increase in resistance). Following the removal of vestibular inputs, brachial blood flow and vascular resistance during head-up tilt were almost unchanged. In contrast, femoral vascular resistance increased only approximately 6% from baseline during 60 deg head-up rotation delivered in the first week after elimination of vestibular signals and approximately 16% in the subsequent 3-week period (as opposed to the approximately 37% increase in resistance that occurred before lesion). These data demonstrate that vestibular inputs associated with postural alterations elicit regionally specific increases in vascular resistance that direct blood flow away from the region of the body where blood pooling may occur. Thus, the data support the hypothesis that vestibular influences on the cardiovascular system serve to protect against the occurrence of orthostatic hypotension. PMID:16809368

  3. Does Attempt at Hearing Preservation Microsurgery of Vestibular Schwannoma Affect Postoperative Tinnitus?

    OpenAIRE

    Chovanec, Martin; Zv??ina, Eduard; Profant, Oliver; Balogová, Zuzana; Kluh, Jan; Syka, Josef; Lisý, Ji?í; Merunka, Ilja; Sk?ivan, Ji?í; Betka, Jan

    2015-01-01

    Background. The aim of this study was to analyze the effect of vestibular schwannoma microsurgery via the retrosigmoid-transmeatal approach with special reference to the postoperative tinnitus outcome. Material and Methods. A prospective study was performed in 89 consecutive patients with unilateral vestibular schwannoma indicated for microsurgery. Patient and tumor related parameters, pre- and postoperative hearing level, intraoperative findings, and hearing and tinnitus handicap inventory s...

  4. Visual-vestibular cue integration for heading perception: Applications of optimal cue integration theory

    OpenAIRE

    Fetsch, Christopher R.; DEANGELIS, GREGORY C.; Angelaki, Dora E.

    2010-01-01

    The perception of self-motion is crucial for navigation, spatial orientation, and motor control. In particular, estimation of one’s direction of translation, or heading, relies heavily on multisensory integration in most natural situations. Visual and non-visual (e.g., vestibular) information can be used to judge heading, but each modality alone is often insufficient for accurate performance. It is not surprising, then, that visual and vestibular signals converge frequently in the nervous sys...

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

    OpenAIRE

    Jocelyne Ventre-Dominey

    2014-01-01

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

  6. 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-?2, 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...

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

    OpenAIRE

    Lyford-Pike, Sofia; Vogelheim, Casey; Chu, Eugene; DELLA SANTINA, CHARLES C.; CAREY, JOHN P.

    2007-01-01

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

  8. Evidence for Purinergic Receptors in Vestibular Dark Cell and Strial Marginal Cell Epithelia of Gerbil

    OpenAIRE

    LIU, JIANZHONG; Kozakura, Kenichi; Marcus, Daniel C

    1995-01-01

    Purinergic receptors have been found to modulate ion transport in several types of epithelial cells as well as excitable cells. It was of interest to determine whether vestibular dark cells and strial marginal cells contain purinergic receptors in either the apicalor basolateral membrane which modulate transepithelial ion transport. Vestibular dark cell and strial marginal cell epithelia were mounted in a micro-Ussing chamber for the measurement of the transepithelial voltage and resistance f...

  9. 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 subj...

  10. Short and long-term postural learning to withstand galvanic vestibular perturbations.

    OpenAIRE

    Tjernström, Fredrik; Bagheri, Ali; Fransson, Per-Anders; Magnusson, Måns

    2010-01-01

    We investigated changes of postural responses to repeated bipolar galvanic vestibular stimulation on 5 consecutive days and once again after 3 months. Subjects consisted of 21 healthy volunteers. Except for the first day did the induced torque variance in response to galvanic vestibular stimulation not decrease {within} each test session, but there was a major reduction {from day to day} (p< 0.001) reflecting a continued processing of the postural experience gained during the stimulation. ...

  11. 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...

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

    Science.gov (United States)

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

    2015-04-01

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

  13. 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...

  14. 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.

  15. 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.

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

    OpenAIRE

    Couloigner, Vincent; Gervaz, Elena; Kalamarides, Michel; Ferrary, Evelyne; Rey, Alain; Sterkers, Olivier; Hénin, Dominique

    2003-01-01

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

  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. Hypergravity effects on succinate dehydrogenase reactivity in fish vestibular ganglia

    Science.gov (United States)

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

    2006-01-01

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

  19. 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.

  20. What can posturography tell us about vestibular function?

    Science.gov (United States)

    Black, F. O.

    2001-01-01

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

  1. 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.

  2. 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.

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

    Directory of Open Access Journals (Sweden)

    Fairbanks Robert K

    2009-12-01

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

  4. [Postoperative facial and vestibular nerve palsy: experimental study of its pathophysiological mechanisms].

    Science.gov (United States)

    Sekiya, T; Okabe, S; Hatayama, T; Iwabuchi, T; Takiguchi, M

    1990-02-01

    The 7th and 8th cranial nerves were shifted in the cerebellopontine (CP) angle of dogs by cerebellar retractions that were similar to those performed in humans with monitoring of auditory evoked brainstem responses (ABR). Postoperatively, the vestibular, facial nerves, and brainstem were histologically examined. Caudal-to-rostral shifts of the nerves could induce vestibular and/or facial nerve damages. The most vulnerable portion of the vestibular nerve was located between the vestibular ganglions and the area vestibularis-the most lateral end of the internal auditory canal. This indicated that due to traction force derived from surgical interventions, the nerves and vessels were avulsed at the fundus of the internal auditory canal. The vestibular nerve may be potentially injured more easily and frequently than the cochlear and facial nerves in retromastoid craniectomies with lateral decubitus position in humans. Direct injuries of the facial nerves in the CP angles were not observed in this study. It was elucidated that the facial nerve was usually injured in the facial canal proximal to the geniculate ganglion due to traction force derived from manipulations in the CP angle. It is likely that as facial nerve edema progresses postoperatively, the facial nerve is gradually compressed within the narrow labyrinthine portion of the facial canal. This may be the cause of delayed postoperative facial nerve palsy. The importance to recognize how not only cochlear but also vestibular and facial nerve are injured by the usual manipulations in the CP angle is stressed. PMID:2357413

  5. Dejerine-Sottas syndrome and vestibular loss due to a point mutation in the PMP22 gene.

    Science.gov (United States)

    Jen, Joanna; Baloh, Robert H; Ishiyama, Akira; Baloh, Robert W

    2005-10-15

    We describe a father and daughter with Dejerine-Sottas syndrome and bilateral vestibular loss due to an L71P missense mutation in the peripheral myelin protein 22 (PMP22). The combination of vestibular loss and peripheral neuropathy led to profound imbalance at a young age. It is important to recognize this combination of peripheral nerve and vestibular deficits since rehabilitation strategies and prognosis are different. PMID:15992829

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

    OpenAIRE

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

    2013-01-01

    Bilateral loss of vestibular sensation can be disabling. We have shown that a multichannel vestibular prosthesis (MVP) can partly restore vestibular sensation as evidenced by improvements in the 3-dimensional angular vestibulo-ocular reflex (3D VOR). However, a key challenge is to minimize misalignment between the axes of eye and head rotation, which is apparently caused by current spread beyond each electrode’s targeted nerve branch. We recently reported that rodents wearing a MVP markedly i...

  7. Síndrome do aqueduto vestibular alargado: relato de 3 casos e revisão bibliográfica / Enlarged vestibular aqueduct syndrome: report of 3 cases and literature review

    Scientific Electronic Library Online (English)

    José A., Pinto; Carlos Fernando, Mello Junior; Ana Carla S., Marqui; Delmer J., Perfeito; Roberto D. P., Ferreira; Rubens H., Silva.

    2005-06-01

    Full Text Available A Síndrome do Aqueduto Vestibular Alargado (SAVA) é caracterizada por um alargamento do aqueduto vestibular associado a uma perda auditiva neurossensorial, algumas vezes mista, que pode ser congênita ou adquirida na infância. A disacusia pode ser dividida em leve, moderada ou profunda, associada com [...] períodos de melhora ou de piora súbita. O alargamento do aqueduto vestibular é a anomalia da orelha interna mais comum. A SAVA é admitida como resultado de uma anormalidade genética no desenvolvimento do aqueduto vestibular anterior à quinta semana de gestação. A incidência de SAVA está entre 1% e 1,3%, podendo chegar a 7% dependendo da população examinada. O objetivo deste estudo é relatar 3 casos de SAVA atendidos no Núcleo de Otorrinolaringologia e Cirurgia de Cabeça e Pescoço de São Paulo e no serviço de Radiologia do Hospital São Camilo - São Paulo, sendo que dois pacientes são irmãos somente por parte materna. Dois pacientes eram do sexo feminino, um do sexo masculino e a idade variou de 9 a 30 anos. O método diagnóstico de eleição é a TC de osso temporais. A conduta para os casos foi o tratamento conservador com ressalva a cuidados como traumatismos cranianos, barotraumas e, quando necessário, uso de próteses auditivas. Abstract in english 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, moderat [...] e 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 diagnostic method of election was CT - Computerized Tomography of the temporal bones. The recommended management of the cases was conservative, except for those of cranial trauma, barotrauma and, if necessary, the use of hearing aids.

  8. Síndrome do aqueduto vestibular alargado: relato de 3 casos e revisão bibliográfica Enlarged vestibular aqueduct syndrome: report of 3 cases and literature review

    Directory of Open Access Journals (Sweden)

    José A. Pinto

    2005-06-01

    Full Text Available A Síndrome do Aqueduto Vestibular Alargado (SAVA é caracterizada por um alargamento do aqueduto vestibular associado a uma perda auditiva neurossensorial, algumas vezes mista, que pode ser congênita ou adquirida na infância. A disacusia pode ser dividida em leve, moderada ou profunda, associada com períodos de melhora ou de piora súbita. O alargamento do aqueduto vestibular é a anomalia da orelha interna mais comum. A SAVA é admitida como resultado de uma anormalidade genética no desenvolvimento do aqueduto vestibular anterior à quinta semana de gestação. A incidência de SAVA está entre 1% e 1,3%, podendo chegar a 7% dependendo da população examinada. O objetivo deste estudo é relatar 3 casos de SAVA atendidos no Núcleo de Otorrinolaringologia e Cirurgia de Cabeça e Pescoço de São Paulo e no serviço de Radiologia do Hospital São Camilo - São Paulo, sendo que dois pacientes são irmãos somente por parte materna. Dois pacientes eram do sexo feminino, um do sexo masculino e a idade variou de 9 a 30 anos. O método diagnóstico de eleição é a TC de osso temporais. A conduta para os casos foi o tratamento conservador com ressalva a cuidados como traumatismos cranianos, barotraumas e, quando necessário, uso de próteses auditivas.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 diagnostic method of election was CT - Computerized Tomography of the temporal bones. The recommended management of the cases was conservative, except for those of cranial trauma, barotrauma and, if necessary, the use of hearing aids.

  9. 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

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

    Scientific Electronic Library Online (English)

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

    2010-03-01

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

  11. 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.

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

    Scientific Electronic Library Online (English)

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

    2015-06-01

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

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

    Science.gov (United States)

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

    2015-02-01

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

  14. NEURON and Python

    OpenAIRE

    MichaelHines; AndrewPDavison; EilifMuller

    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 ...

  15. Distribution of acetylcholine and catecholamine neurons in the cat brainstem: a choline acetyltransferase and tyrosine hydroxylase immunohistochemical study.

    Science.gov (United States)

    Jones, B E; Beaudet, A

    1987-07-01

    The distribution of acetylcholine neurons in the brainstem of the cat was studied by choline acetyltransferase (ChAT) immunohistochemistry and compared to that of catecholamine neurons examined in the same or adjacent sections by tyrosine hydroxylase (TH) immunohistochemistry. The largest group of ChAT-positive (+) neurons was located in the lateral pontomesencephalic tegmentum within the pedunculopontine tegmental nucleus and the laterodorsal tegmental nucleus rostrally and within the parabrachial nuclei and locus coeruleus nucleus more caudally. TH+ neurons were found to be coextensive and intermingled with ChAT+ neurons in the dorsolateral pontomesencephalic tegmentum, where the number of ChAT+ cells (approximately 18,500) exceeded that of the TH+ cells (approximately 12,000). In the caudal pons, scattered ChAT+ neurons were situated in the ventrolateral tegmentum together with TH+ neurons. In the medulla, numerous ChAT+ cells were located in the lateral tegmental field, where they extended in a radial column from the dorsal motor nucleus of the vagus to the ventrolateral tegmentum around the facial and ambiguus nuclei, occupying the position of preganglionic parasympathetic neurons of the 7th, 9th, and 10th cranial nerves. TH+ cells were also present in this field. Neurons within the general visceral, special visceral, and somatic motor cranial nerve nuclei were all immunoreactive to ChAT. Scattered ChAT+ neurons were also present within the medullary gigantocellular and magnocellular tegmental fields together with a small number of TH+ neurons. Other groups of ChAT+ cells were identified within the periolivary nuclei, parabigeminal nucleus, prepositus hypoglossi nucleus, and the medial and inferior vestibular nuclei. Acetylcholine neurons thus constitute a heterogeneous population of cells in the brainstem, which in addition to including the somatic and visceral efferent systems, comprises many other discrete systems and represents an important component of the brainstem reticular formation. The proximity to and interdigitation with catecholamine neurons within these systems may be of important functional significance. PMID:2887593

  16. 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

  17. 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.)

  18. 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.)

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

    OpenAIRE

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

    2014-01-01

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

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

    Scientific Electronic Library Online (English)

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

    2011-08-01

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

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

    Scientific Electronic Library Online (English)

    Raquel Ferreira de, Sousa; Juliana Maria, Gazzola; Maurício Malavasi, Ganança; Célia Aparecida, Paulino.

    2011-12-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2010-02-01

    Galvanic vestibular stimulation (GVS) results in characteristic muscle and whole-body responses in humans maintaining standing balance. However, the relationship between these two vestibular-evoked responses remains elusive. This study seeks to determine whether mechanical filtering from conversion of lower-limb muscle activity to body sway, during standing balance, can be used to attenuate sway while maintaining biphasic lower-limb muscle responses using frequency-limited stochastic vestibular stimulation (SVS). We hypothesized that SVS deprived of frequencies vestibular-evoked muscle responses from whole-body sway (0-25, 1-25, and 2-25 Hz). Two main results emerged: 1) SVS-related sway was attenuated when frequencies vestibular stimuli during conversion to muscle activity, anteroposterior (AP) moment, and sway. This successive low-pass filtering limited the transfer of signal power to frequencies 2 Hz to standing humans do not cause a destabilizing whole-body sway response but are associated with the typical biphasic lower-limb muscle responses. PMID:20032237

  4. 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

  5. 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.

  6. 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.

  7. 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.

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

    Science.gov (United States)

    Lowery, Mary Sue

    1998-01-01

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

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

    DEFF Research Database (Denmark)

    Schüz, Joachim; Steding-Jessen, Marianne

    2011-01-01

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

  10. 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.

  11. Extracranial non-vestibular head and neck schwannomas

    Directory of Open Access Journals (Sweden)

    Baoxin Wang

    2015-11-01

    Full Text Available Objectives: To retrospectively describe our 10-year experience with extracranial non-vestibular head and neck schwannomas by presenting their clinical features, diagnostic methods, surgical decisions, and treatment outcomes. Methods: This is a retrospective study conducted at the Department of Otolaryngology, Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Shanghai First People’s Hospital, Shanghai, China. The medical records of 46 patients diagnosed with schwannoma in the extracranial head and neck region as confirmed on paraffin-embedded sections from January 2003 to December 2012 were reviewed. Results: All tumors were benign, and 52% presented as asymptomatic palpable solitary masses. Compressive symptoms, which can represent meaningful indicators of the nerve of origin were commonly noted. The most common nerve of origin was the brachial plexus (n=13, 28.3%. Conclusion: While postoperative histopathologic examination is still the gold standard, fine needle aspiration cytology, CT scan, and magnetic resonance imaging may be useful in the diagnosis of schwannomas. As schwannomas are radioresistant, and as, despite their benign nature, can cause severe secondary symptoms, the best treatment of choice is complete excision with preservation of functions.

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

    Science.gov (United States)

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

    2012-01-01

    Summary 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. PMID:25991975

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

    Scientific Electronic Library Online (English)

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

    2013-06-01

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

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

    Scientific Electronic Library Online (English)

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

    2012-12-01

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

  15. 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.

  16. Compensation of vestibular symptoms in hemilabyrinthectomized guinea pigs. Role of the sensorimotor activation.

    Science.gov (United States)

    Petrosini, L

    1983-06-01

    The effect of sensorimotor activation on compensatory rate of vestibular asymmetries after unilateral labyrinthectomy was analyzed in guinea pigs. An intensified sensorimotor activation was obtained by putting in water the animals immediately after the appearance of hemilabyrinthectomy (HL) symptoms. The water-maintained group exhibited a faster dampening of vestibular disturbances in comparison with control animals. Both ocular and postural asymmetries declined to about 50% of peak values after 2-3 h from HL, while in control group the same extent of recovery was achieved in 4-6 h from HL. It is concluded that the generalized activation of the ascending spinal pathways carrying exteroceptive and proprioceptive information to the vestibular nuclei represents a favourable condition for the regainment of ocular and postural balance impaired by HL. PMID:6871018

  17. 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.

  18. Astronaut Owen Garriott as test subject for Human Vestibular Function exp.

    Science.gov (United States)

    1973-01-01

    Scientist-Astronaut Owen K. Garriott, Skylab 3 science pilot, serves as test subject for the Skylab Human Vestibular Function M131 Experiment, as seen in this photographic reproduction taken from a television transmission made by a color TV camera aboard the Skylab space station in Earth orbit. The objectives of the M131 experiment are to obtain data pertinent to establishing the validity of measurements of specific behavioral/physiological responses influenced by vestibular activity under one-G and zero-G conditions; to determine man's adaptability to unusual vestibular conditions and predict habitability of future spacecraft conditions involving reduced gravity and Coriollis forces; and to measure the accuracy and variability in man's judgement of spatial coordinates based on atypical gravity receptor cues and inadequate visual cues.

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

    Directory of Open Access Journals (Sweden)

    Di Giovanna J.

    2010-01-01

    Full Text Available 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 sensors rigidly affixed to the user. These sensors provide information about rotational velocity of the head; the prosthetic then transfers the information to the vestibular nerve via electrical stimulation. Here we present a project overview, development details, and summarize our progress in animal models and selected human volunteers.

  20. 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...

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

    Science.gov (United States)

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

    2004-01-01

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

  2. 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.

  3. Short latency vestibular evoked potentials in the Japanese quail (Coturnix coturnix japonica)

    Science.gov (United States)

    Jones, S. M.; Jones, T. A.; Shukla, R.

    1997-01-01

    Short-latency vestibular-evoked potentials to pulsed linear acceleration were characterized in the quail. Responses occurred within 8 ms following the onset of stimuli and were composed of a series of positive and negative peaks. The latencies and amplitudes of the first four peaks were quantitatively characterized. Mean latencies at 1.0 g ms-1 ranged from 1265 +/- 208 microseconds (P1, N = 18) to 4802 +/- 441 microseconds (N4, N = 13). Amplitudes ranged from 3.72 +/- 1.51 microV (P1/N1, N = 18) to 1.49 +/- 0.77 microV (P3/N3, N = 16). Latency-intensity (LI) slopes ranged from -38.7 +/- 7.3 microseconds dB-1 (P1, N = 18) to -71.6 +/- 21.9 microseconds dB-1 (N3, N = 15) and amplitude-intensity (AI) slopes ranged from 0.20 +/- 0.08 microV dB-1 (P1/N1, N = 18) to 0.07 +/- 0.04 microV dB-1 (P3/N3, N = 11). The mean response threshold across all animals was -21.83 +/- 3.34 dB re: 1.0 g ms-1 (N = 18). Responses remained after cochlear extirpation showing that they could not depend critically on cochlear activity. Responses were eliminated by destruction of the vestibular end organs, thus showing that responses depended critically and specifically on the vestibular system. The results demonstrate that the responses are vestibular and the findings provide a scientific basis for using vestibular responses to evaluate vestibular function through ontogeny and senescence in the quail.

  4. Reabilitação vestibular na qualidade de vida e sintomatologia de tontura de idosos / Vestibular rehabilitation in the quality of life and the symptomatology of dizziness among the elderly

    Scientific Electronic Library Online (English)

    Paulo Roberto, Rocha Júnior; Elton Storto, Kozan; Josué Ferreira de, Moraes; Fernando Garbi, Pereira; Adriana Bassan, Moreno.

    2014-08-01

    Full Text Available O objetivo do artigo é analisar o efeito de um protocolo estruturado de reabilitação vestibular na sintomatologia de tontura e qualidade de vida de idosos. Participaram nove idosos, quatro do gênero masculino e cinco do feminino. Utilizou-se para avaliação da qualidade de vida o Dizziness Handicap I [...] nventory - DHI e para a sintomatologia de tontura, a escala de quantificação de tontura. Desenvolveu-se um protocolo de reabilitação vestibular constituído de atividades em grupo. Para a análise dos dados, utilizou-se o teste de Wilcoxon e teste T de Student. Utilizou-se o Coeficiente de Correlação de Spearman para analisar a relação entre qualidade de vida e sintomatologia de tontura. O nível de significância utilizado foi de 5%. Observou-se melhora significativa da sintomatologia de tontura, da qualidade de vida geral e dos aspectos físicos, emocionais e funcionais após a realização do programa. Verificou-se ainda, uma boa correlação positiva entre sintomatologia de tontura e qualidade de vida. Conclui-se que os participantes do programa obtiveram uma melhora significativa da tontura, qualidade de vida geral e dos seus respectivos aspectos pós-reabilitação vestibular. Observou-se ainda uma boa correlação entre sintomatologia de tontura e qualidade de vida geral. Abstract in english The scope of this paper was to analyze the effect of a structured protocol of vestibular rehabilitation in the symptomatology of dizziness and the quality of life among the elderly. Nine elderly individuals were attended, namely four males and five females. The Dizziness Handicap Inventory (DHI) was [...] used to assess quality of life and the dizziness quantification scale for the symptomatology of dizziness. A protocol for vestibular rehabilitation consisting of group activities was then developed. The Wilcoxon test and Student t-test were used for data analysis. The Spearman correlation coefficient was used to analyze the relationship between quality of life and the symptomology of dizziness. The significance level used was 5%. There was significant improvement in the symptomatology of dizziness, overall quality of life and physical, emotional and functional aspects after completion of the program. There was also a good positive correlation between the symptomatology of dizziness and quality of life. The conclusion reached was that program participants had a significant improvement of dizziness, general quality of life and their respective vestibular rehabilitation aspects. There was also a good correlation between symptomatology of dizziness and overall quality of life.

  5. 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.

  6. Avaliação imunológica nas pregas vestibulares de pacientes autopsiados com a Síndrome da Imunodeficiência Adquirida / Immunological evaluation of vestibular folds in autopsies of patients with the Acquired Immunodeficiency Syndrome

    Scientific Electronic Library Online (English)

    Janaínna Grazielle Pacheco, Olegário; Renata Calciolari, Rossi; Ana Karina Marques, Salge; Rosana Rosa Miranda, Corrêa; Vicente de Paula Antunes, Teixeira; Eumenia Costa da Cunha, Castro.

    2008-06-01

    Full Text Available Em pacientes com Síndrome da Imunodeficiência Adquirida há uma diminuição das células envolvidas na resposta imune, o que influencia na população celular dos folículos linfóides encontrados nas pregas vestibulares, favorecendo o aparecimento de infecções nas vias aéreas destes pacientes. Estas infec [...] ções são a principal causa de mortalidade e morbidade nestes pacientes. OBJETIVO: Caracterizar a população de células nos folículos linfóides localizados nas pregas vestibulares de adultos autopsiados com Síndrome da Imunodeficiência Adquirida, com e sem infecções respiratórias associadas. MATERIAIS E MÉTODOS: Foi realizado um estudo retrospectivo transversal em 64 laringes de adultos coletadas na rotina das autopsias. Para a imunohistoquímica foram utilizados os anticorpos: Anti-B cells, Anti-CD3, Anti-CD68 e Anti-follicular dendritic cells. RESULTADOS: 46 (71,87%) dos pacientes estudados tinham diagnóstico de Síndrome da Imunodeficiência Adquirida. Nestes pacientes, a celularidade dos folículos linfóides foi estatisticamente menor em relação ao grupo controle em todos os fenótipos estudados. Nos pacientes imunodeprimidos com infecção respiratória associada, o número de células estava diminuído, sendo significante no caso dos linfócitos T (p=0,024). CONCLUSÃO: Em nosso estudo demonstramos que os folículos linfóides das pregas vestibulares são afetados pela infecção viral e representam com fidedignidade o estado imunológico de imunodepressão destes pacientes. Abstract in english Immune response cells are decreased in patients with the Acquired Immunodeficiency Syndrome. This alters the cell population in vestibular fold lymphoid follicles, leading to respiratory infections in these patients. Such infections are the main cause of mortality and morbidity in these patients. AI [...] M: to characterize lymphoid follicle cell populations in the vestibular folds of adults with the Acquired Immunodeficiency Syndrome and associated or not respiratory infection. MATERIALS AND METHODS: A retrospective study was made of 64 adult larynges harvested during routine autopsies. Anti-B cell, Anti-CD3, Anti-CD68 and Anti-follicular dendritic cell antibodies were used for immunological testing. RESULTS: 46 (71.87%) of the sample patients had the Acquired Immunodeficiency Syndrome. In these patients, lymphoid follicle cellularity was lower compared to the control group. The cell number was decreased in patients with the Acquired Immunodefficiency Syndrome and associated respiratory tract infection. CONCLUSION: We demonstrated in this study that vestibular fold lymphoid follicles were affected by viral infections, and may be considered as a reliable marker of immunodepression in these patients.

  7. Influência da reabilitação vestibular na qualidade de vida de indivíduos labirintopatas / Influence of vestibular rehabilitation on the quality of life of individuals with labyrinth disease

    Scientific Electronic Library Online (English)

    Shirley Nogueira, Soares; Maria Adriana da Silva, Gonçalves; Claudiana Gomes, Teixeira; Priscila Caetano, Romualdo; Juliana Nunes, Santos.

    2014-06-01

    Full Text Available Objetivo verificar a influência da reabilitação vestibular sobre a qualidade de vida dos indivíduos por meio do questionário Dizziness Handicap Inventory aplicado pré e pós-terapia. Métodos: foram analisados 28 prontuários de indivíduos de ambos os sexos atendidos em uma Clínica Escola do municípi [...] o de Belo Horizonte. Os pacientes responderam ao questionário pré e pós terapia de reabilitação vestibular personalizada (RVP). A análise estatística dos dados foi feita por meio do teste T-Student pareado. Resultados a amostra do estudo foi composta por 28 pacientes, sendo 23 (82 %) do sexo feminino. A idade média dos pacientes foi de 54,7 (± 20,6) anos e o número médio de sessões de terapia foi 5,6 (± 6,4). Antes do tratamento os pacientes apresentaram os seguintes escores: 18,10 (±9,83) nos aspectos físicos, 13,53 (±8,57) nos funcionais e 15,14 (±7,48) nos emocionais. Após uma média de 5,6 (± 6,4) sessões, houve diminuição significante (p Abstract in english Purpose to check the influence of vestibular rehabilitation concerning the quality of life of individuals through Brazilian questionnaire Dizziness Handicap Inventory applied pre and post-therapy. Methods 28 medical chart of individual of both sexes attended in a public teaching clinic at Belo [...] Horizonte city, in where they were analyzed. On analyzed medical chart patients were been submitted to the questionnaire pre and post individual vestibular rehabilitation. The statistical analysis from the data was done through the paired T-Student test. Results the sample of study medical chart was composed of 28 patients, 23 (82%) of them were female. The average of ages was 54,7 years (±20,6) and the medium number of sessions was 5,6 (± 6,4). Before the treatment patients showed the following scores: 18,10 (±9,83) physics aspects, 13,5 (±8,57) functions and 15,14 (±7,48) emotional. After medium of 5,6 (± 6,4) sessions, there was a significant reduction in the physics 4,32 (±5,32), functions 4,32 (±6,91) and emotional 3,78 (±5,16) aspects. Conclusion it can be conclude that there was a significant statistic difference between the questionnaire scores pre and post personalized vestibular rehabilitation, showing that the vestibular rehabilitation is an important instrument on the improvement of life quality for with labyrinth disease.

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

    Directory of Open Access Journals (Sweden)

    Carsten M. Klingner

    2014-01-01

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

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

    Science.gov (United States)

    Temple, D. R.; De Dios, Y. E.; Layne, C. S.; Bloomberg, J. J.; Mulavara, A. 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.

  10. 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.

  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. 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.

  13. Molecular genetic analysis of the NF2 gene in young patients with unilateral vestibular schwannomas

    OpenAIRE

    Mohyuddin, A; NEARY, W; Wallace, A; Wu, C.; Purcell, S; Reid, H.; RAMSDEN, R; Read, A.; G. Black; D. Evans

    2002-01-01

    Neurofibromatosis type 2 (NF2) must be suspected in patients presenting with a unilateral vestibular schwannoma at a young age who are therefore at theoretical risk of developing bilateral disease. We identified 45 patients aged 30 years or less at the onset of symptoms of a unilateral vestibular schwannoma. Molecular genetic analysis of the NF2 gene was completed on peripheral blood samples in all 45 and on 28 tumour samples. No pathogenic NF2 mutations were identified in any of the blood sa...

  14. Pretreatment Growth Rate Predicts Radiation Response in Vestibular Schwannomas

    International Nuclear Information System (INIS)

    Purpose: Vestibular schwannomas (VS) are often followed without initial therapeutic intervention because many tumors do not grow and radiation therapy is associated with potential adverse effects. In an effort to determine whether maximizing initial surveillance predicts for later treatment response, the predictive value of preirradiation growth rate of VS on response to radiation therapy was assessed. Methods and Materials: Sixty-four patients with 65 VS were treated with single-fraction stereotactic radiation surgery or fractionated stereotactic radiation therapy. Pre- and postirradiation linear expansion rates were estimated using volumetric measurements on sequential magnetic resonance images (MRIs). In addition, postirradiation tumor volume change was classified as demonstrating shrinkage (ratio of volume on last follow-up MRI to MRI immediately preceding irradiation <80%), stability (ratio 80%-120%), or expansion (ratio >120%). The median pre- and postirradiation follow-up was 20.0 and 27.5 months, respectively. Seven tumors from neurofibromatosis type 2 (NF2) patients were excluded from statistical analyses. Results: In the 58 non-NF2 patients, there was a trend of correlation between pre- and postirradiation volume change rates (slope on linear regression, 0.29; P=.06). Tumors demonstrating postirradiation expansion had a median preirradiation growth rate of 89%/year, and those without postirradiation expansion had a median preirradiation growth rate of 41%/year (P=.02). As the preirradiation growth rate increased, the probability of postirradiation expansion also increased. Overall, 24.1% of tumors were stable, 53.4% experienced shrinkage, and 22.5% experienced expansion. Predictors of no postirradiation tumor expansion included no prior surgery (P=.01) and slower tumor growth rate (P=.02). The control of tumors in NF2 patients was only 43%. Conclusions: Radiation therapy is an effective treatment for VS, but tumors that grow quickly preirradiation may be more likely to increase in size. Clinicians should take into account tumor growth rate when counseling patients about treatment options

  15. Socio-demographic distribution of vestibular schwannomas in Denmark

    DEFF Research Database (Denmark)

    Stepanidis, Karen; Kessel, Marie

    2014-01-01

    CONCLUSION: Vestibular schwannomas (VSs) are diagnosed less frequently in the remote parts of Denmark, whereas the diagnostic age and tumor size is the same across the different socio-demographic areas of Denmark. OBJECTIVE: To determine whether VSs are diagnosed equally often in different socio-demographic areas of Denmark and whether a change has occurred during the period 1976-2012. In addition, differences in diagnostic age and tumor size between areas were explored. METHODS: Since 1976, all patients diagnosed with a VS in Denmark have been registered in a national database, in which information on, for example, the size of the tumor and the age and address of the patient has been registered. Up to 2012, 2739 patients were diagnosed with a VS. Patient distribution according to area of habitat was determined by subgrouping into urban, suburban, rural, and remote municipalities, using the definitions of socio-demographic areas elaborated by Demarks Statistic. RESULTS: The mean national incidence increased almost linearly over the time period from 6.1 per million per year in the first period from 1976 to 1984, to 22.1 per million per year in the last period from 2003 to 2012. There was a lower incidence at the end of the period in the remote areas compared with the other socio-demographic areas (1976-1984, p = 0.05 and 2003-2011, p = 0.001). The mean age at diagnosis increased during the period, from 52.6 years in the first period to 58.6 years in the last period. There was no significant difference in the age distribution between socio- demographic areas. The mean diagnostic tumor size decreased during the period, from 28.6 mm in the first period to about 10 mm in the last period. There was no significant difference in the size of the tumor between socio- demographic areas.

  16. 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)

  17. Current treatment strategy in the management of vestibular schwannoma

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    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.

  18. Hearing preservation in vestibular schwannoma stereotactic radiosurgery: what really matters?

    Science.gov (United States)

    Linskey, Mark E

    2013-12-01

    Stereotactic radiosurgery (SRS) for vestibular schwannomas has evolved and improved over time. Although early short-term follow-up reports suggest that fractionation yields hearing preservation rates equivalent to modern single-dose SRS techniques, significant questions remain regarding long-term tumor control after the use of fractionation in a late responding tumor with a low proliferative index and ?/? ratio. With single-dose SRS, critical hearing preservation variables include: 1) strict attention to prescription dose 3D conformality so that the ventral cochlear nucleus (VCN) receives ? 9 Gy; 2) careful delineation of the 3D tumor margin to exclude the cochlear nerve when visualizable with contrast-enhanced T2-weighted MR volumetric imaging techniques and exclusion the dura mater of the anterior border of the internal auditory canal; 3) a tumor margin dose prescription ? 12 Gy; 4) optimization of the tumor treatment gradient index without sacrificing coverage and conformality; and 5) strict attention to prescription dose 3D conformality so that the modiolus and the basal turn of the cochlea receive the lowest possible dose (ideally < 4-5.33 Gy). Testable correlates for the relative importance of the VCN versus cochlear dose given the tonotopic organization of each structure suggests that VCN toxicity should lead to preferential loss of low hearing frequencies, while cochlear toxicity should lead to preferential loss of high hearing frequencies. The potential after SRS for hearing toxicity from altered endolymph and/or perilymph fluid dynamics either via impaired fluid production and/or absorption has yet to be explored. Serous otitis media, ossicular or temporal bone osteonecrosis, and chondromalacia are not likely to be relevant factors or considerations for hearing preservation after SRS. PMID:25077325

  19. 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.

  20. Potencial evocado auditivo para diagnóstico de surdez em gato com síndrome vestibular periférica / Auditory evoked potential for deafness diagnosis in a cat with peripheral vestibular syndrome

    Scientific Electronic Library Online (English)

    M.I.P., Palumbo; P.C., Jark; L.H.A., Machado; V.M.V., Machado; L.A.L., Resende; A.S., Borges.

    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. Abstract in english The brainstem auditory evoked potential is an electrodiagnostic test that allows a functional assessment of the auditory pathways from the middle ear to the brainstem. This test, in veterinary medicine, is not commonly used in Brazil. This paper reports the use of auditory evoked potential for deafn [...] ess detection in a cat with unilateral peripheral vestibular syndrome secondary to otitis media.

  1. Utilidad de la electronistagmografía en el diagnóstico topográfico de las enfermedades vestibulares Usefulness of electronistagmography in the topographic diagnosis of vestibular diseases

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    Eulalia Alfonso Muñoz

    2008-06-01

    Full Text Available Se estudiaron 50 pacientes que presentaron enfermedad vestibular durante un período de 2 años, con el objetivo de determinar cómo contribuye la electronistagmografía al diagnóstico topográfico en pacientes con estas afecciones. Está demostrado que la aplicación correcta de la práctica clínica y el interrogatorio no es sustituible por alguna prueba diagnóstica y de hecho, se sabe que en el estudio del paciente con vértigo, lo antes expresado constituye lo más importante. Sin embargo, existe aproximadamente un 30 % de estos enfermos con diagnóstico dudoso, donde las pruebas complementarias desempeñan una función fundamental. De los casos estudiados, el 78,0 % correspondió al sexo femenino y predominaron las edades de 50 a 59 años (52,0 %. Las causas más comúnmente encontradas fueron la vascular (32,0 %, seguida en orden de frecuencia por las secuelas de enfermedades vírales (20,0 %. Se concluye que la electronistagmografía es una prueba con un carácter objetivo fundamental para diagnóstico topográfico de las enfermedades vestibulares.50 patients that presented vestibular disease during 2 years were studied aimed at determining how electronistagmography contributes to the topographic diagnosis in patients with these affections. It has been proved that the adequate application of clinical practice and interview cannot be replaced by any diagnostic test and, in fact, it is known that in the study of the patient suffering from vertigo, the above mentioned is the most important. However, approximately 30 % of these patients have an uncertain diagnosis, where the complementary tests play a fundamental role. Of the studied cases, 78.0 % were females and it was observed a predominance of ages 50-59 (52.0 %. The most common causes were the vascular (32.0 %, followed by the sequelae of viral diseases (20.0 %. It was concluded that electronistagmography is a test with an essential objective character for the topographic diagnosis of the vestibular diseases.

  2. Staging in giant vestibular schwannoma surgery: A two consecutive day technique for complete resection in basic neurosurgical setups

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    Deepak Bandlish

    2014-01-01

    Full Text Available Introduction: Vestibular schwannomas constitute 8% of all intracranial tumors. A majority of vestibular schwannomas are sporadic and unilateral. Giant vestibular schwannomas are seen in our country due to the late diagnosis and long duration of symptoms before diagnosis. These giant schwannomas are challenging to manage as most of the patients are having brainstem compression. Materials and Methods: Twelve cases of a giant vestibular schwannoma were operated in our department between May 2011 and December 2012. Vestibular schwannomas with a maximal diameter of more than 4 cm were defined as a giant vestibular schwannoma. All the patients had a unilateral vestibular schwannoma. Performance status of all the patients were graded as per the Karnofsky performance score. Pre-operative assessment of 5 th , 7 th , 8 th and lower cranial nerve status was done in all cases. Ventriculoperitoneal shunting was done pre-operatively in all cases. All patients were operated through retromastoid suboccipital craniectomy and retrosigmoid approach. These patients were operated in two stages in two consecutive days with overnight elective ventilation in ICU. Ultrasonic aspirator and nerve monitoring techniques were not used. Results: Giant acoustic schwannomas can be safely resected completely by a staged resection on two consecutive days without any increased morbidity or mortality. This technique may be employed to achieve complete resection of such lesions without deterioration of facial nerve function in institutions which do not have advanced facilities like nerve monitoring or ultrasonic aspirator.

  3. Potencial miogênico evocado vestibular: proposição de um novo instrumento / Vestibular evoked myogenic potential: we propose a new instrument

    Scientific Electronic Library Online (English)

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

    2010-12-01

    Full Text Available INTRODUÇÃO: Atualmente, ainda não existe um instrumento específico para a avaliação dos potencias miogênicos evocados vestibulares, sendo a mesma realizada por meio de um equipamento desenvolvido para a captação de potenciais evocados auditivos, disponível no mercado. Assim, as funções de amplificaç [...] ão, filtragem, estimulação, janela de captação, rejeição de artefatos e características de promediação, bem como o próprio software de gerenciamento, ficam muito a desejar para a nova função que lhe é atribuída. OBJETIVO: Comparar latências e amplitudes das componentes p13 e n23, e os índices de assimetria, entre um equipamento considerado padrão-ouro (EP25), adaptado para o registro deste potencial, e o novo equipamento desenvolvido. MÉTODO: Estudo experimental com 11 ouvintes normais. A partir de estímulos sonoros tone-burst de 10 ms, frequência de 500 Hz, com intensidade de 90 dBNAn, foram registrados potenciais miogênicos evocados com janelas de 80 ms. RESULTADOS: Pode-se constatar ausência de diferenças significativas, quando comparados os dois instrumentos, quanto aos parâmetros de latência e amplitude, exceto para a latência de n23, com valor de p = 0,005. O valor do índice de assimetria inter-pico p13-n23, para o novo aparelho (20,1%), foi significativamente menor que o encontrado para o EP25 (30,5%), com p menor que 0,01. CONCLUSÃO: Desta forma, conclui-se, que não existem diferenças para as latências e amplitudes do VEMP entre o EP25 e o novo dispositivo desenvolvido, apresentando, este último, maior proximidade com os valores descritos na literatura e menor índice de assimetria da amplitude inter-pico p13-n23. Forma de estudo: prospectivo, clínico e experimental. Abstract in english INTRODUCTION: Currently, there is still no specific instrument for assessment of vestibular evoked myogenic potentials, with the same performed by a device designed to capture auditory evoked potentials available in the market. Thus, the functions of amplification, filtering, stimulation, window cap [...] ture, rejection of artifacts and features of averaging, as well as its management software, are much to be desired for the new role assigned to it. OBJECTIVE: To compare latencies and amplitudes of components p13 and n23, and the indices of asymmetry between a devices considered the gold standard (EP25), adapted to record the potential and the new equipment developed. METHOD: An experimental study with 11 normal hearing. From the tone-burst sound stimuli of 10 ms, frequency of 500 Hz with intensity 90 dBNAn, evoked myogenic potentials were recorded with 80 ms windows. RESULTS: You can see no significant differences when comparing the two instruments regarding the parameters of latency and amplitude, except for the latency of n23, with p = 0.005. The value of asymmetry index inter-p13-n23 peak for the new unit (20.1%) was significantly lower than that found for the EP25 (30.5%), with p less than 0.01. Conclusion: Thus, we conclude that there are no differences for the latencies and amplitudes of VEMP between the EP25 and the new device developed by presenting the latter, closer to the values reported in literature and a lower index of asymmetry of amplitude between p13-n23 peak. Study form: Prospective clinical and experimental.

  4. Reabilitação vestibular com realidade virtual na doença de Ménière / Vestibular rehabilitation with virtual reality in Ménière's disease

    Scientific Electronic Library Online (English)

    Adriana Pontin, Garcia; Mauricio Malavasi, Ganança; Flávia Salvaterra, Cusin; Andreza, Tomaz; Fernando Freitas, Ganança; Heloisa Helena, Caovilla.

    2013-06-01

    Full Text Available A tecnologia de realidade virtual fornece uma grande variedade de estímulos que geram conflitos sensoriais em diferentes níveis de dificuldades e em ambiente seguro. OBJETIVO: Verificar o efeito de um programa de reabilitação vestibular do equilíbrio corporal com estímulos de realidade virtual em pa [...] cientes com doença de Ménière. Forma de estudo: Estudo clínico observacional. MÉTODO: Quarenta e quatro pacientes, com idade entre 18 e 60 anos e doença de Ménière definida, distribuídos em dois grupos - experimental (GE) e controle (GC) - fizeram uso de betaistina e dieta alimentar; o grupo experimental foi submetido adicionalmente a 12 sessões de reabilitação com realidade virtual da BRU TM. Os pacientes responderam ao Dizziness Handicap Inventory (DHI), à escala analógica de tontura e realizaram a posturografia com realidade virtual antes e após a intervenção. RESULTADOS: Após a intervenção, o GE apresentou valores significantemente menores do DHI (p Abstract in english Virtual reality technology can provide a wide range of sensory stimuli to generate conflicts of varying degrees of complexity in a safe environment. OBJECTIVE: To verify the effect of a virtual realitybased balance rehabilitation program for patients with Menière's disease. METHOD: This observationa [...] l clinical study included 44 patients aged between 18 and 60 years diagnosed with Menière's disease submitted to a controlled randomized therapeutic intervention. The case and control groups took betahistine and followed a diet. Case group subjects underwent 12 rehabilitation sessions with virtual reality stimuli in a Balance Rehabilitation Unit (BRU TM). Patients were assessed based on DHI scores, the dizziness visual analogue scale, and underwent posturography with virtual reality before and after the intervention. RESULTS: After the intervention, the case group showed significantly lower scores in DHI (p

  5. NEURON and Python

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    Michael Hines

    2009-01-01

    Full Text Available 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 all existing models written in Hoc, including GUI tools, continue to work without change and are also available within the Python context. An example of the benefits of Python availability is the use of the XML module in implementing NEURON's Import3D and CellBuild tools to read MorphML and NeuroML model specifications.

  6. Quantum neuron design

    Science.gov (United States)

    Behrman, Elizabeth; Steck, James

    2014-03-01

    In previous work, we have developed quantum systems that can learn and do information processing much like artificial neural networks. These learning methods have some advantages over other implementations of quantum computing in that they construct their own algorithms and could be robust to noise and decoherence. Here we take the next step