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Sample records for acute vestibular neuritis

  1. Normal Caloric Responses during Acute Phase of Vestibular Neuritis

    PubMed Central

    Lee, Sun-Uk; Park, Seong-Ho; Kim, Hyo-Jung; Koo, Ja-Won

    2016-01-01

    Background and Purpose We report a novel finding of caloric conversion from normal responses into unilateral paresis during the acute phase of vestibular neuritis (VN). Methods We recruited 893 patients with a diagnosis of VN at Dizziness Clinic of Seoul National University Bundang Hospital from 2003 to 2014 after excluding 28 patients with isolated inferior divisional VN (n=14) and those without follow-up tests despite normal caloric responses initially (n=14). We retrospectively analyzed the neurotological findings in four (0.5%) of the patients who showed a conversion from initially normal caloric responses into unilateral paresis during the acute phase. Results In those four patients, the initial caloric tests were performed within 2 days of symptom onset, and conversion into unilateral caloric paresis was documented 1–4 days later. The clinical and laboratory findings during the initial evaluation were consistent with VN in all four patients except for normal findings in bedside head impulse tests in one of them. Conclusions Normal findings in caloric tests should be interpreted with caution during the acute phase of suspected VN. Follow-up evaluation should be considered when the findings of the initial caloric test are normal, but VN remains the most plausible diagnosis. PMID:26932259

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

    PubMed Central

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

    2013-01-01

    Vestibular processing is fundamental to our sense of orientation in space which is a core aspect of the representation of the self. Vestibular information is processed in a large subcortical–cortical neural network. Tasks requiring mental rotations of human bodies in space are known to activate neural regions within this network suggesting that vestibular processing is involved in the control of mental rotation. We studied whether mental rotation is impaired in patients suffering from two different forms of unilateral vestibular disorders (vestibular neuritis – VN – and Benign Paroxysmal positional Vertigo – BPPV) with respect to healthy matched controls (C). We used two mental rotation tasks in which participants were required to: (i) mentally rotate their own body in space (egocentric rotation) thus using vestibular processing to a large extent and (ii) mentally rotate human figures (allocentric rotation) thus using own body representations to a smaller degree. Reaction times and accuracy of responses showed that VN and BPPV patients were impaired in both tasks with respect to C. Significantly, the pattern of results was similar in the three groups suggesting that patients were actually performing the mental rotation without using a different strategy from the control individuals. These results show that dysfunctional vestibular inflow impairs mental rotation of both own body and human figures suggesting that unilateral acute disorders of the peripheral vestibular input massively affect the cerebral processes underlying mental rotations. PMID:24324422

  3. Is Vestibular Neuritis an Immune Related Vestibular Neuropathy Inducing Vertigo?

    PubMed Central

    Greco, A.; Macri, G. F.; Gallo, A.; Fusconi, M.; De Virgilio, A.; Pagliuca, G.; Marinelli, C.; de Vincentiis, M.

    2014-01-01

    Objectives. To review the current knowledge of the aetiology of vestibular neuritis including viral infections, vascular occlusion, and immunomediated mechanisms and to discuss the pathogenesis with relevance to pharmacotherapy. Systematic Review Methodology. Relevant publications on the aetiology and treatment of vestibular neuritis from 1909 to 2013 were analysed. Results and Conclusions. Vestibular neuritis is the second most common cause of peripheral vestibular vertigo and is due to a sudden unilateral loss of vestibular function. Vestibular neuronitis is a disorder thought to represent the vestibular-nerve equivalent of sudden sensorineural hearing loss. Histopathological studies of patients who died from unrelated clinical problems have demonstrated degeneration of the superior vestibular nerve. The characteristic signs and symptoms include sudden and prolonged vertigo, the absence of auditory symptoms, and the absence of other neurological symptoms. The aetiology and pathogenesis of the condition remain unknown. Proposed theories of causation include viral infections, vascular occlusion, and immunomediated mechanisms. The management of vestibular neuritis involves symptomatic treatment with antivertiginous drugs, causal treatment with corticosteroids, and physical therapy. Antiviral agents did not improve the outcomes. PMID:24741601

  4. Acute optic neuritis

    PubMed Central

    Galetta, Steven L.; Villoslada, Pablo; Levin, Netta; Shindler, Kenneth; Ishikawa, Hiroshi; Parr, Edward; Cadavid, Diego

    2015-01-01

    Idiopathic demyelinating optic neuritis (ON) most commonly presents as acute unilateral vision loss and eye pain and is frequently associated with multiple sclerosis. Although emphasis is often placed on the good recovery of high-contrast visual acuity, persistent deficits are frequently observed in other aspects of vision, including contrast sensitivity, visual field testing, color vision, motion perception, and vision-related quality of life. Persistent and profound structural and functional changes are often revealed by imaging and electrophysiologic techniques, including optical coherence tomography, visual-evoked potentials, and nonconventional MRI. These abnormalities can impair patients' abilities to perform daily activities (e.g., driving, working) so they have important implications for patients' quality of life. In this article, we review the sequelae from ON, including clinical, structural, and functional changes and their interrelationships. The unmet needs in each of these areas are considered and the progress made toward meeting those needs is examined. Finally, we provide an overview of past and present investigational approaches for disease modification in ON. PMID:26236761

  5. Vertical eye movements during horizontal head impulse test: a new clinical sign of superior vestibular neuritis.

    PubMed

    D'Onofrio, F

    2013-12-01

    In some patients suffering from acute unilateral peripheral vestibular deficit, the head impulse test performed towards the affected side reveals the typical catch-up saccade in the horizontal plane, and an oblique, mostly vertical, upward catch-up saccade after the rotation of the head towards the healthy side. Three cases are reported herein, which have been studied using slow motion video analysis of the eye movements captured by a high-speed webcam (90 fps). The clinical evidence is discussed and a pathophysiological explanation is proposed, consisting in a selective hypofunction of the superior semicircular canal during superior vestibular neuritis. PMID:24376299

  6. Postural control in patients after a recent vestibular neuritis with hyperhomocysteinemia.

    PubMed

    Raponi, G; Teggi, R; Gatti, O; Giordano, L; Bussi, M

    2013-04-01

    To assess the possible role of hyperhomocysteinemia (HyHcy) in delaying recovery after acute vestibular neuritis. In our retrospective study, 90 subjects were evaluated within 7 days from the beginning of an acute vertigo. All subjects had high plasma levels of homocysteine (Hcy). 46 patients were treated with homocysteine lowering therapy and betahistine for 1 month, while 44 subjects received only betahistine. Subjective symptoms were evaluated with the Dizziness Handicap Inventory (DHI) questionnaire, administered 7 days after the beginning of vertigo and again after 1 month. Moreover, postural control performed at 1 month' control was studied with static stabilometry in a subgroup of 21 non-treated and 20 treated patients. DHI total score decreased significantly more in the subgroup of subjects treated with homocysteine lowering therapy. Moreover, posturographic data were significantly increased in non-treated compared with treated subjects. Our data support the possibility of a role of HyHcy in preventing recovery after a recent vestibular neuritis. A microvascular disorder or the neurotoxic effect of HyHcy have been considered as possible causal factors. Although not conclusive, our data are not inconsistent with the hypothesis of a poorer adaptation in patients with untreated HyHcy. PMID:24427555

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

    PubMed Central

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

    2014-01-01

    Vestibular neuritis is defined as a sudden unilateral partial failure of the vestibular nerve that impairs the forwarding of vestibular information from the labyrinth. The patient suffers from vertigo, horizontal nystagmus and postural instability with a tendency toward ipsilesional falls. Although vestibular neuritis is a common disease, the central mechanisms to compensate for the loss of precise vestibular information remain poorly understood. It was hypothesized that symptoms following acute vestibular neuritis originate from difficulties in the processing of diverging sensory information between the responsible brain networks. Accordingly an altered resting activity was shown in multiple brain areas of the task-positive network. Because of the known balance between the task-positive and task-negative networks (default mode network; DMN) we hypothesize that also the DMN is involved. Here, we employ functional magnetic resonance imaging (fMRI) in the resting state to investigate changes in the functional connectivity between the DMN and task-positive networks, in a longitudinal design combined with measurements of caloric function. We demonstrate an initially disturbed connectedness of the DMN after vestibular neuritis. We hypothesize that the disturbed connectivity between the default mode network and particular parts of the task-positive network might be related to a sustained utilization of processing capacity by diverging sensory information. The current results provide some insights into mechanisms of central compensation following an acute vestibular deficit and the importance of the DMN in this disease. PMID:25379422

  8. Cervical and ocular vestibular-evoked myogenic potentials in vestibular neuritis: comparison between air- and bone-conducted stimulation.

    PubMed

    Oh, Sun-Young; Kim, Ji-Soo; Yang, Tae-Ho; Shin, Byoung-Soo; Jeong, Seul-Ki

    2013-08-01

    To clarify the changes of cervical (cVEMP) and ocular (oVEMP) vestibular evoked myogenic potentials induced by air-conducted sound (ACS) and bone-conducted vibration (BCV) in patients with vestibular neuritis (VN), patients with VN (n = 30) and normal controls (n = 45) underwent recording of cVEMP and oVEMP in response to ACS (1,000 Hz, 5 ms, tone bursts) and BCV (500 Hz, short tone burst). Patients with VN showed a high proportion of oVEMP abnormalities in response to both ACS (80.0 %) and BCV at the forehead (Fz, 73.3 %) or the mastoid (76.7 %). In contrast, cVEMPs were mostly normal with both ACS and BCV in the patients. The dissociations in the abnormalities of cVEMP and oVEMP induced by ACS and BCV at the mastoids and at the forehead in patients with VN suggest that oVEMP reflects functions of the superior vestibular nerve and most likely the utricular function. The results of our study suggest that oVEMP induced by either ACS or BCV appears to depend on integrity of the superior vestibular nerve, possibly due to the utricular afferents travelling in it. In contrast, cVEMP elicited by either ACS or BCV may reflect function of the saccular afferents running in the inferior vestibular nerve. PMID:23670310

  9. Serial Magnetization Transfer Imaging in Acute Optic Neuritis

    ERIC Educational Resources Information Center

    Hickman, S. J.; Toosy, A. T.; Jones, S. J.; Altmann, D. R.; Miszkiel, K. A.; MacManus, D. G.; Barker, G. J.; Plant, G. T.; Thompson, A. J.; Miller, D.H.

    2004-01-01

    In serial studies of multiple sclerosis lesions, reductions in magnetization transfer ratio (MTR) are thought to be due to demyelination and axonal loss, with later rises due to remyelination. This study followed serial changes in MTR in acute optic neuritis in combination with clinical and electrophysiological measurements to determine if the MTR…

  10. Unidentified Bright Objects on Brain Magnetic Resonance Imaging Affect Vestibular Neuritis

    PubMed Central

    Kim, Ji Chan; Chang, Dong Sik; Cho, Chin Saeng

    2015-01-01

    Objectives The aim of this study was to investigate the differences in clinical manifestations of in two groups of vestibular neuritis (VN) patients with or without unidentified bright objects (UBOs). Methods A prospective, observational study with 46 patients diagnosed with VN between May 2013 and November 2013 was executed. A caloric test, a cervical vestibular-evoked myogenic potentials (cVEMPs) test, brain magnetic resonance imaging (MRI), spontaneous nystagmus test, head impulse test, and head-shaking nystagmus test were performed. Results Of the patients, 56.5% (n=26) were classified as UBO-positive by MRI. These showed lower caloric weakness and more prominent cVEMP asymmetry compared with the UBO-negative group (P<0.05). Total VN (TVN) was the most common in the UBO-positive group (45.0%), followed by superior VN (SVN, 30.0%), and inferior VN (IVN, 25.0%). However, in the UBO-negative group, SVN (75.0%) was the most common, followed by TVN and IVN (P<0.05). The recovery rate was not influenced by UBOs (P>0.05). Conclusion UBOs on T2-weighted or fluid attenuated inversion recovery MRI may affect the patterns of the vestibular nerve in patients with VN. PMID:26622955

  11. The afferent pupillary defect in acute optic neuritis.

    PubMed Central

    Ellis, C J

    1979-01-01

    Twenty-two patients with acute optic neuritis were studied by the techniques of infrared pupillometry and visual evoked responses (VER) to pattern reversal. A relative afferent pupillary defect was found in all cases and the magnitude of this defect was found to be related to the amplitude, but not to the latency, of the VER. During follow-up the afferent defect was found to remain persistently abnormal while other methods of clinical evaluation could not demonstrate abnormality reliably. The amplitude of the VER also remained low. PMID:501365

  12. Multiple sclerosis as a cause of the acute vestibular syndrome.

    PubMed

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

    2013-06-01

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

  13. Head impulse gain and saccade analysis in pontine-cerebellar stroke and vestibular neuritis

    PubMed Central

    Todd, Michael; Halmagyi, Gabor M.; Aw, Swee

    2014-01-01

    Objective: We sought to quantify and compare angular vestibulo-ocular reflex (aVOR) gain and compensatory saccade properties elicited by the head impulse test (HIT) in pontine-cerebellar stroke (PCS) and vestibular neuritis (VN). Methods: Horizontal HIT was recorded ≤7 days from vertigo onset with dual-search coils in 33 PCS involving the anterior inferior, posterior inferior, and superior cerebellar arteries (13 AICA, 17 PICA, 3 SCA) confirmed by MRI and 20 VN. We determined the aVOR gain and asymmetry, and compensatory overt saccade properties including amplitude asymmetry and cumulative amplitude (ipsilesional trials [I]; contralesional trials [C]). Results: The aVOR gain (normal: 0.96; asymmetry = 2%) was bilaterally reduced, greater in AICA (I = 0.39, C = 0.57; asymmetry = 20%) than in PICA/SCA strokes (I = 0.75, C = 0.74; asymmetry = 7%), in contrast to the unilateral deficit in VN (I = 0.22, C = 0.76; asymmetry = 54%). Cumulative amplitude (normal: 1.1°) was smaller in AICA (I = 4.2°, C = 3.0°) and PICA/SCA strokes (I = 2.1°, C = 3.0°) compared with VN (I = 8.5°, C = 1.3°). Amplitude asymmetry in AICA and PICA/SCA strokes was comparable, but favored the contralesional side in PICA/SCA strokes and the ipsilesional side in VN. Saccade asymmetry <61% was found in 97% of PCS and none of VN. Gain asymmetry <40% was found in 94% of PCS and 10% of VN. Conclusion: HIT gains and compensatory saccades differ between PCS and VN. VN was characterized by unilateral gain deficits with asymmetric large saccades, AICA stroke by more symmetric bilateral gain reduction with smaller saccades, and PICA stroke by contralesional gain bias with the smallest saccades. Saccade and gain asymmetry should be investigated further in future diagnostic accuracy studies. Classification of evidence: This study provides Class II evidence that aVOR testing accurately distinguishes patients with PCS from VN (sensitivity 94%–97%, specificity 90%–100%). PMID:25253747

  14. Re-evaluating the treatment of acute optic neuritis

    PubMed Central

    Bennett, Jeffrey L; Nickerson, Molly; Costello, Fiona; Sergott, Robert C; Calkwood, Jonathan C; Galetta, Steven L; Balcer, Laura J; Markowitz, Clyde E; Vartanian, Timothy; Morrow, Mark; Moster, Mark L; Taylor, Andrew W; Pace, Thaddeus W W; Frohman, Teresa; Frohman, Elliot M

    2015-01-01

    Clinical case reports and prospective trials have demonstrated a reproducible benefit of hypothalamic-pituitary-adrenal (HPA) axis modulation on the rate of recovery from acute inflammatory central nervous system (CNS) demyelination. As a result, corticosteroid preparations and adrenocorticotrophic hormones are the current mainstays of therapy for the treatment of acute optic neuritis (AON) and acute demyelination in multiple sclerosis. Despite facilitating the pace of recovery, HPA axis modulation and corticosteroids have failed to demonstrate long-term benefit on functional recovery. After AON, patients frequently report visual problems, motion perception difficulties and abnormal depth perception despite ‘normal’ (20/20) vision. In light of this disparity, the efficacy of these and other therapies for acute demyelination require re-evaluation using modern, high-precision paraclinical tools capable of monitoring tissue injury. In no arena is this more amenable than AON, where a new array of tools in retinal imaging and electrophysiology has advanced our ability to measure the anatomic and functional consequences of optic nerve injury. As a result, AON provides a unique clinical model for evaluating the treatment response of the derivative elements of acute inflammatory CNS injury: demyelination, axonal injury and neuronal degeneration. In this article, we examine current thinking on the mechanisms of immune injury in AON, discuss novel technologies for the assessment of optic nerve structure and function, and assess current and future treatment modalities. The primary aim is to develop a framework for rigorously evaluating interventions in AON and to assess their ability to preserve tissue architecture, re-establish normal physiology and restore optimal neurological function. PMID:25355373

  15. Re-evaluating the treatment of acute optic neuritis.

    PubMed

    Bennett, Jeffrey L; Nickerson, Molly; Costello, Fiona; Sergott, Robert C; Calkwood, Jonathan C; Galetta, Steven L; Balcer, Laura J; Markowitz, Clyde E; Vartanian, Timothy; Morrow, Mark; Moster, Mark L; Taylor, Andrew W; Pace, Thaddeus W W; Frohman, Teresa; Frohman, Elliot M

    2015-07-01

    Clinical case reports and prospective trials have demonstrated a reproducible benefit of hypothalamic-pituitary-adrenal (HPA) axis modulation on the rate of recovery from acute inflammatory central nervous system (CNS) demyelination. As a result, corticosteroid preparations and adrenocorticotrophic hormones are the current mainstays of therapy for the treatment of acute optic neuritis (AON) and acute demyelination in multiple sclerosis.Despite facilitating the pace of recovery, HPA axis modulation and corticosteroids have failed to demonstrate long-term benefit on functional recovery. After AON, patients frequently report visual problems, motion perception difficulties and abnormal depth perception despite 'normal' (20/20) vision. In light of this disparity, the efficacy of these and other therapies for acute demyelination require re-evaluation using modern, high-precision paraclinical tools capable of monitoring tissue injury.In no arena is this more amenable than AON, where a new array of tools in retinal imaging and electrophysiology has advanced our ability to measure the anatomic and functional consequences of optic nerve injury. As a result, AON provides a unique clinical model for evaluating the treatment response of the derivative elements of acute inflammatory CNS injury: demyelination, axonal injury and neuronal degeneration.In this article, we examine current thinking on the mechanisms of immune injury in AON, discuss novel technologies for the assessment of optic nerve structure and function, and assess current and future treatment modalities. The primary aim is to develop a framework for rigorously evaluating interventions in AON and to assess their ability to preserve tissue architecture, re-establish normal physiology and restore optimal neurological function. PMID:25355373

  16. The Diagnostic Accuracy of Truncal Ataxia and HINTS as Cardinal Signs for Acute Vestibular Syndrome

    PubMed Central

    Carmona, Sergio; Martínez, Carlos; Zalazar, Guillermo; Moro, Marcela; Batuecas-Caletrio, Angel; Luis, Leonel; Gordon, Carlos

    2016-01-01

    The head impulse, nystagmus type, test of skew (HINTS) protocol set a new paradigm to differentiate peripheral vestibular disease from stroke in patients with acute vestibular syndrome (AVS). The relationship between degree of truncal ataxia and stroke has not been systematically studied in patients with AVS. We studied a group of 114 patients who were admitted to a General Hospital due to AVS, 72 of them with vestibular neuritis (based on positive head impulse, abnormal caloric tests, and negative MRI) and the rest with stroke: 32 in the posterior inferior cerebellar artery (PICA) territory (positive HINTS findings, positive MRI) and 10 in the anterior inferior cerebellar artery (AICA) territory (variable findings and grade 3 ataxia, positive MRI). Truncal ataxia was measured by independent observers as grade 1, mild to moderate imbalance with walking independently; grade 2, severe imbalance with standing, but cannot walk without support; and grade 3, falling at upright posture. When we applied the HINTS protocol to our sample, we obtained 100% sensitivity and 94.4% specificity, similar to previously published findings. Only those patients with stroke presented with grade 3 ataxia. Of those with grade 2 ataxia (n = 38), 11 had cerebellar stroke and 28 had vestibular neuritis, not related to the patient’s age. Grade 2–3 ataxia was 92.9% sensitive and 61.1% specific to detect AICA/PICA stroke in patients with AVS, with 100% sensitivity to detect AICA stroke. In turn, two signs (nystagmus of central origin and grade 2–3 Ataxia) had 100% sensitivity and 61.1% specificity. Ataxia is less sensitive than HINTS but much easier to evaluate. PMID:27551274

  17. The Diagnostic Accuracy of Truncal Ataxia and HINTS as Cardinal Signs for Acute Vestibular Syndrome.

    PubMed

    Carmona, Sergio; Martínez, Carlos; Zalazar, Guillermo; Moro, Marcela; Batuecas-Caletrio, Angel; Luis, Leonel; Gordon, Carlos

    2016-01-01

    The head impulse, nystagmus type, test of skew (HINTS) protocol set a new paradigm to differentiate peripheral vestibular disease from stroke in patients with acute vestibular syndrome (AVS). The relationship between degree of truncal ataxia and stroke has not been systematically studied in patients with AVS. We studied a group of 114 patients who were admitted to a General Hospital due to AVS, 72 of them with vestibular neuritis (based on positive head impulse, abnormal caloric tests, and negative MRI) and the rest with stroke: 32 in the posterior inferior cerebellar artery (PICA) territory (positive HINTS findings, positive MRI) and 10 in the anterior inferior cerebellar artery (AICA) territory (variable findings and grade 3 ataxia, positive MRI). Truncal ataxia was measured by independent observers as grade 1, mild to moderate imbalance with walking independently; grade 2, severe imbalance with standing, but cannot walk without support; and grade 3, falling at upright posture. When we applied the HINTS protocol to our sample, we obtained 100% sensitivity and 94.4% specificity, similar to previously published findings. Only those patients with stroke presented with grade 3 ataxia. Of those with grade 2 ataxia (n = 38), 11 had cerebellar stroke and 28 had vestibular neuritis, not related to the patient's age. Grade 2-3 ataxia was 92.9% sensitive and 61.1% specific to detect AICA/PICA stroke in patients with AVS, with 100% sensitivity to detect AICA stroke. In turn, two signs (nystagmus of central origin and grade 2-3 Ataxia) had 100% sensitivity and 61.1% specificity. Ataxia is less sensitive than HINTS but much easier to evaluate. PMID:27551274

  18. Diffusion fMRI detects white-matter dysfunction in mice with acute optic neuritis

    PubMed Central

    Lin, Tsen-Hsuan; Spees, William M.; Chiang, Chia-Wen; Trinkaus, Kathryn; Cross, Anne H.; Song, Sheng-Kwei

    2014-01-01

    Optic neuritis is a frequent and early symptom of multiple sclerosis (MS). Conventional magnetic resonance (MR) techniques provide means to assess multiple MS-related pathologies, including axonal injury, demyelination, and inflammation. A method to directly and non-invasively probe white-matter function could further elucidate the interplay of underlying pathologies and functional impairments. Previously, we demonstrated a significant 27% activation-associated decrease in the apparent diffusion coefficient of water perpendicular to the axonal fibers (ADC⊥) in normal C57BL/6 mouse optic nerve with visual stimulation using diffusion fMRI. Here we apply this approach to explore the relationship between visual acuity, optic nerve pathology, and diffusion fMRI in the experimental autoimmune encephalomyelitis (EAE) mouse model of optic neuritis. Visual stimulation produced a significant 25% (vs. baseline) ADC⊥ decrease in sham EAE optic nerves, while only a 7% (vs. baseline) ADC⊥ decrease was seen in EAE mice with acute optic neuritis. The reduced activation-associated ADC⊥ response correlated with post-MRI immunohistochemistry determined pathologies (including inflammation, demyelination, and axonal injury). The negative correlation between activation-associated ADC⊥ response and visual acuity was also found when pooling EAE-affected and sham groups under our experimental criteria. Results suggest that reduction in diffusion fMRI directly reflects impaired axonal-activation in EAE mice with optic neuritis. Diffusion fMRI holds promise for directly gauging in vivo white-matter dysfunction or therapeutic responses in MS patients. PMID:24632420

  19. Acute Unilateral Vestibular Failure Does Not Cause Spatial Hemineglect

    PubMed Central

    Conrad, Julian; Habs, Maximilian; Brandt, Thomas; Dieterich, Marianne

    2015-01-01

    Objectives Visuo-spatial neglect and vestibular disorders have common clinical findings and involve the same cortical areas. We questioned (1) whether visuo-spatial hemineglect is not only a disorder of spatial attention but may also reflect a disorder of higher cortical vestibular function and (2) whether a vestibular tone imbalance due to an acute peripheral dysfunction can also cause symptoms of neglect or extinction. Therefore, patients with an acute unilateral peripheral vestibular failure (VF) were tested for symptoms of hemineglect. Methods Twenty-eight patients with acute VF were assessed for signs of vestibular deficits and spatial neglect using clinical measures and various common standardized paper-pencil tests. Neglect severity was evaluated further with the Center of Cancellation method. Pathological neglect test scores were correlated with the degree of vestibular dysfunction determined by the subjective visual vertical and caloric testing. Results Three patients showed isolated pathological scores in one or the other neglect test, either ipsilesionally or contralesionally to the VF. None of the patients fulfilled the diagnostic criteria of spatial hemineglect or extinction. Conclusions A vestibular tone imbalance due to unilateral failure of the vestibular endorgan does not cause spatial hemineglect, but evidence indicates it causes mild attentional deficits in both visual hemifields. PMID:26247469

  20. Optic neuritis

    MedlinePlus

    Retro-bulbar neuritis; Multiple sclerosis - optic neuritis; Optic nerve - optic neuritis ... The exact cause of optic neuritis is unknown. The optic nerve carries visual information from your eye to the brain. The nerve can swell when ...

  1. Diagnostic accuracy of acute vestibular syndrome at the bedside in a stroke unit.

    PubMed

    Chen, L; Lee, W; Chambers, B R; Dewey, H M

    2011-05-01

    Acute vestibular syndrome may be due to vestibular neuritis (VN) or posterior circulation strokes. Bedside ocular motor testing performed by experts is superior to early MRI in excluding strokes. We sought to demonstrate that differentiation of strokes from VN in our stroke unit is reliable. During a prospective study at a tertiary hospital over 1 year, patients with AVS were evaluated in the emergency department (ED) and underwent admission with targeted examination: gait, gaze-holding, horizontal head impulse test (hHIT), testing for skew deviation (SD) and vertical smooth pursuit (vSP). Neuroimaging included CT, transcranial Doppler (TCD) and MRI with MR angiogram (MRA). VN was diagnosed with normal diffusion-weighted images (DWI) and absence of neurological deficits on follow-up. Acute strokes were confirmed with DWI. A total of 24 patients with AVS were enrolled and divided in two groups. In the pure vestibular group (n = 20), all VN (n = 10/10) had positive hHIT and unidirectional nystagmus, but 1 patient had SD and abnormal vertical smooth pursuit (SP). In all the strokes (n = 10/10), one of the following signs suggestive of central lesion was present: negative hHIT, central-type nystagmus, SD or abnormal vSP. Finding one of these was 100% sensitive and 90% specific for stroke. In the cochleovestibular group (n = 4) all had normal DWI, but 3 patients had central ocular motor signs (abnormal vertical SP and SD). Whilst the study is small, classification of AVS in our stroke unit is reliable. The sensitivity and specificity of bedside ocular motor testing are comparable to those previously reported by expert neuro-otologists. Acute cochleovestibular loss and normal DWI may signify a labyrinthine infarct but differentiating between different causes of inner ear dysfunction is not possible with bedside testing. PMID:21153732

  2. Labyrinthitis and Vestibular Neuritis

    MedlinePlus

    ... any further problems. A key component of successful adaptation is a dedicated effort to keep moving, despite ... can prolong or even prevent the process of adaptation. Authors: Charlotte L. Shupert, PhD with contributions from ...

  3. Optic neuritis

    MedlinePlus

    ... pneumonia and other common upper respiratory tract infections Multiple sclerosis ... have optic neuritis without a disease such as multiple sclerosis have a good chance of recovery. Optic neuritis ...

  4. Serial Diffusion Tensor Imaging of the Optic Radiations after Acute Optic Neuritis

    PubMed Central

    van der Walt, Anneke; Butzkueven, Helmut; Klistorner, Alexander; Egan, Gary F.; Kilpatrick, Trevor J.

    2016-01-01

    Previous studies have reported diffusion tensor imaging (DTI) changes within the optic radiations of patients after optic neuritis (ON). We aimed to study optic radiation DTI changes over 12 months following acute ON and to study correlations between DTI parameters and damage to the optic nerve and primary visual cortex (V1). We measured DTI parameters [fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD)] from the optic radiations of 38 acute ON patients at presentation and 6 and 12 months after acute ON. In addition, we measured retinal nerve fibre layer thickness, visual evoked potential amplitude, optic radiation lesion load, and V1 thickness. At baseline, FA was reduced and RD and MD were increased compared to control. Over 12 months, FA reduced in patients at an average rate of −2.6% per annum (control = −0.51%; p = 0.006). Change in FA, RD, and MD correlated with V1 thinning over 12 months (FA: R = 0.450, p = 0.006; RD: R = −0.428, p = 0.009; MD: R = −0.365, p = 0.029). In patients with no optic radiation lesions, AD significantly correlated with RNFL thinning at 12 months (R = 0.489, p = 0.039). In conclusion, DTI can detect optic radiation changes over 12 months following acute ON that correlate with optic nerve and V1 damage. PMID:27555964

  5. Human Rabies with Initial Manifestations that Mimic Acute Brachial Neuritis and Guillain-Barré Syndrome

    PubMed Central

    Mader, Edward C.; Maury, Joaquin S.; Santana-Gould, Lenay; Craver, Randall D.; El-Abassi, Rima; Segura-Palacios, Enrique; Sumner, Austin J.

    2012-01-01

    Introduction Human rabies can be overlooked in places where this disease is now rare. Its diagnosis is further confused by a negative history of exposure (cryptogenic rabies), by a Guillain-Barré syndrome (GBS) type of presentation, or by symptoms indicating another diagnosis, eg, acute brachial neuritis (ABN). Case presentation A 19-year-old Mexican, with no past health problems, presented with a two-day history of left shoulder, arm, and chest pain. He arrived in Louisiana from Mexico five days prior to admission. Of particular importance is the absence of a history of rabies exposure and immunization. On admission, the patient had quadriparesis, areflexia, and elevated protein in the cerebrospinal fluid, prompting a diagnosis of GBS. However, emerging neurological deficits pointed towards acute encephalitis. Rabies was suspected on hospital day 11 after common causes of encephalitis (eg, arboviruses) have been excluded. The patient tested positive for rabies IgM and IgG. He died 17 days after admission. Negri bodies were detected in the patient’s brain and rabies virus antigen typing identified the vampire bat as the source of infection. Conclusion Rabies should be suspected in every patient with a rapidly evolving GBS-like illness—even if there is no history of exposure and no evidence of encephalitis on presentation. The patient’s ABN-like symptoms may be equivalent to the pain experienced by rabies victims near the inoculation site. PMID:22577299

  6. Importance of spontaneous nystagmus detection in the differential diagnosis of acute vertigo.

    PubMed

    Pavlin-Premrl, Davor; Waterston, John; McGuigan, Sean; Infeld, Bernard; Sultana, Ron; O'Sullivan, Richard; Gerraty, Richard P

    2015-03-01

    Vertigo is a common cause of emergency department attendance. Detection of spontaneous nystagmus may be a useful sign in distinguishing vestibular neuritis from other vestibular diagnoses. We aimed to assess the contribution of spontaneous nystagmus in the diagnosis of acute vertigo. We enrolled consecutive consenting patients arriving at a single emergency department with acute vertigo. There was no declared protocol for the emergency department staff. A standardized history and examination was conducted by the investigators. Observation for spontaneous nystagmus, its response to visual fixation, and testing the vestibulo-ocular reflex with the horizontal head impulse test were the chief examination components. MRI was obtained within 24 hours. Clinical criteria and MRI were used to reach the final diagnosis. The investigators' physical findings and final neurological diagnosis were compared with the initial emergency department examination findings and the referral diagnosis. There were 28 patients, 15 with vestibular neuritis, six with benign paroxysmal positional vertigo, one with stroke, suspected clinically, and three with migraine. In three the diagnosis remained uncertain. Spontaneous nystagmus was seen in all 15 patients with vestibular neuritis, fixation-suppressed in eight of 11 tested for this. The head impulse test was positive in 12 of 15 with vestibular neuritis. The emergency department referral diagnosis was correct in six of 23 patients. The ability to detect spontaneous nystagmus is useful in vestibular diagnosis, both in support of a diagnosis of vestibular neuritis and in avoiding false positive diagnoses of benign paroxysmal positional vertigo. PMID:25537400

  7. Optic neuritis

    PubMed Central

    Pau, D; Al Zubidi, N; Yalamanchili, S; Plant, G T; Lee, A G

    2011-01-01

    Aims The aim of this study is to provide a clinical update on optic neuritis (ON), its association with multiple sclerosis (MS), and neuromyelitis optica (NMO). Methods This study included a PubMed review of the literature written in the English language. Results ON in adults is typically idiopathic or demyelinating, and is characterised by unilateral, subacute, painful loss of vision that is not associated with any systemic or other neurological symptoms. Demyelinating ON is associated with MS, and we review the key studies of ON including the ON treatment trial and several other MS treatment trials and NMO. Conclusion Acute demyelinating ON can occur in isolation or be associated with MS. Typical ON does not require additional evaluation other than cranial magnetic resonance imaging. NMO is likely a separate disorder from MS and the ON in NMO has a different treatment and prognosis. Methodology The authors conducted an English language search using Pubmed from the years 1964 to 2010 using the search terms ‘ON', ‘MS' and ‘NMO'. The authors included original articles, review articles, and case reports, which revealed new aspects as far as epidemiology, histopathology, clinical manifestations, imaging, genetics, and treatment of ON. Titles were reviewed for topicality and full references were obtained. Letters to the editor, unpublished work, and abstracts were not included in this review. PMID:21527960

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

    PubMed

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

    2011-07-01

    We review current pharmacological treatments for peripheral and central vestibular disorders, and ocular motor disorders that impair vision, especially pathological nystagmus. The prerequisites for successful pharmacotherapy of vertigo, dizziness, and abnormal eye movements are the "4 D's": correct diagnosis, correct drug, appropriate dosage, and sufficient duration. There are seven groups of drugs (the "7 A's") that can be used: antiemetics; anti-inflammatory, anti-Ménière's, and anti-migrainous medications; anti-depressants, anti-convulsants, and aminopyridines. A recovery from acute vestibular neuritis can be promoted by treatment with oral corticosteroids. Betahistine may reduce the frequency of attacks of Ménière's disease. The aminopyridines constitute a novel treatment approach for downbeat and upbeat nystagmus, as well as episodic ataxia type 2 (EA 2); these drugs may restore normal "pacemaker" activity to the Purkinje cells that govern vestibular and cerebellar nuclei. A limited number of trials indicate that baclofen improves periodic alternating nystagmus, and that gabapentin and memantine improve acquired pendular and infantile (congenital) nystagmus. Preliminary reports suggest suppression of square-wave saccadic intrusions by memantine, and ocular flutter by beta-blockers. Thus, although progress has been made in the treatment of vestibular neuritis, some forms of pathological nystagmus, and EA 2, controlled, masked trials are still needed to evaluate treatments for many vestibular and ocular motor disorders, including betahistine for Ménière's disease, oxcarbazepine for vestibular paroxysmia, or metoprolol for vestibular migraine. PMID:21461686

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

    PubMed

    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

  10. Early Diagnosis and Management of Acute Vertigo from Vestibular Migraine and Ménière's Disease.

    PubMed

    Seemungal, Barry; Kaski, Diego; Lopez-Escamez, Jose Antonio

    2015-08-01

    Vestibular migraine is the most common cause of acute episodic vestibular symptoms after benign paroxysmal positional vertigo. In contrast, Ménière's disease is an uncommon disorder. For both conditions, early and accurate diagnosis (or its exclusion) enables the correct management of patients with acute episodic vestibular symptoms. Long-term management of migraine requires changes in lifestyle to avoid triggers of migraine and/or prophylactic drugs if attacks become too frequent. The long-term management of Ménière's disease also involves lifestyle changes (low salt diet), medications (betahistine, steroids), and ablative therapy applied to the diseased ear (eg, intratympanic gentamicin). PMID:26231275

  11. 25-Hydroxyvitamin D levels in acute monosymptomatic optic neuritis: relation to clinical severity, paraclinical findings and risk of multiple sclerosis.

    PubMed

    Pihl-Jensen, Gorm; Frederiksen, Jette Lautrup

    2015-07-01

    Optic neuritis (ON) is a common first symptom of MS and only few studies have thus far investigated vitamin D at this early stage of MS. The objectives of the study were to examine total 25-hydroxyvitamin D levels (25HVITDL) in patients in acute (A) ON and to determine whether 25HVITD levels in AON (1) predict risk of RRMS and (2) are associated with visual tests of ON severity. A cross-sectional study was conducted of mean 25HVITDL differences between ON (n = 164) and MS (n = 948) patients and of prevalence of 25HVITDL deficiency (<50 nmol/L) in ON and MS (two-sample t test, χ (2) test). Associations between 25HVITDL and (1) clinical ON severity, (2) paraclinical findings suggestive of MS [logistic regression (LRA), Spearman correlation] and (3) hazard of MS development [Cox (C) RA] in ON patients were assessed. 25HVITDL were deseasonalized before analysis. The mean levels were 47.6 (ON) and 63.9 (MS) nmol/L (p < 0.0001), and a significantly higher prevalence of 25HVITD deficiency in ON (56 %; 35 %) (p < 0.0001), most pronounced in females, was shown. Associations were found between 25HVITDL and both CSF leukocyte count (ρ = -0.177, p = 0.028) and IgG index elevation (OR 0.980, p = 0.031). Forty-one ON patients developed MS during the study. Multivariate CRA showed no effect on hazard of MS (HR: 0.991, p 0.284). No association was found between 25HVITDL and visual tests (acuity, contrast vision) or OCT RNFL or GCL thickness. The study indicates a high prevalence of 25HVITD deficiency in AON. 25HVITDL was significantly associated with CSF leukocyte count, but not ON severity. The study indicates a possible role of vitamin D in the early stages of MS, but does not support the use of 25HVITDL as a predictor of MS development in acute ON. PMID:25929657

  12. Pharmacotherapy of vestibular disorders and nystagmus.

    PubMed

    Strupp, Michael; Kremmyda, Olympia; Brandt, Thomas

    2013-07-01

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

  13. Post-Plasmodium vivax malaria cerebellar ataxia and optic neuritis: A new form of delayed cerebellar ataxia or cerebellar variant of acute disseminated encephalomyelitis?

    PubMed Central

    Kasundra, Gaurav M.; Bhargava, Amita Narendra; Bhushan, Bharat; Shubhakaran, Khichar; Sood, Isha

    2015-01-01

    Acute disseminated encephalomyelitis (ADEM) is commonly seen after viral and bacterial infections, immunization, and Plasmodium falciparum (PF) malaria. Plasmodium vivax (PV) rarely causes ADEM. We report a 14-year-old female patient who presented with acute onset bilateral cerebellar ataxia and optic neuritis, 2 weeks after recovery from PV. Magnetic resonance imaging showed bilateral cerebellar hyperintensities suggestive of ADEM. No specific viral etiology was found on cerebrospinal fluid examination. Patient responded well to treatment without any sequelae. Thus, PV too is an important cause of ADEM along with PF. Two of the previously reported cases had co-infection with falciparum malaria. The only other two reported cases, as also this patient, are from Asia. A geographical or racial predisposition needs to be evaluated. Also, a possibility of post-PV delayed cerebellar ataxia, which is classically described post-PF infection, may be considered as it may be clinically, radiologically, and prognostically indistinguishable from a milder presentation of ADEM. PMID:25878748

  14. Acute necrosis after Gamma Knife surgery in vestibular schwannoma leading to multiple cranial nerve palsies.

    PubMed

    Kapitza, Sandra; Pangalu, Athina; Horstmann, Gerhard A; van Eck, Albert T; Regli, Luca; Tarnutzer, Alexander A

    2016-08-01

    We discuss a rare acute complication after Gamma Knife therapy (Elekta AB, Stockholm, Sweden) in a single patient. A 52-year-old woman presented with vertigo, facial weakness and hearing loss emerging 48hours following Gamma Knife radiosurgery for a right-sided vestibular schwannoma. Neurological examination 6days after symptom onset showed right-sided facial palsy, spontaneous left-beating nystagmus and pathologic head-impulse testing to the right. Pure-tone audiogram revealed right-sided sensorineural hearing loss. A diagnosis of acute vestibulocochlear and facial neuropathy was made. Brain MRI demonstrated focal contrast sparing within the schwannoma, likely related to acute radiation necrosis. Acute multiple cranial neuropathies of the cerebellopontine angle after Gamma Knife treatment should raise suspicion of acute tissue damage within the schwannoma and should result in urgent MRI. Treatment with steroids may be considered based on accompanying swelling and edema. PMID:26947104

  15. [A Patient with Acute Limbic Encephalitis Associated with Anti-Glutamate Receptor Antibodies and Subsequent Optic Neuritis].

    PubMed

    Murakami, Aya; Nakamura, Masataka; Kaneko, Satoshi; Takahashi, Yukitoshi; Kusaka, Hirofumi

    2016-03-01

    A 19-year-old woman presented with headache and fever. Cerebrospinal fluid (CSF) analysis revealed increased pressure (>200 mmH2O) and pleocytosis. Brain MRI showed high intensity in the medial part of the right temporal lobe, insular regions, and basal ganglia of the right hemisphere on fluid attenuated inversion recovery images. Based on a tentative diagnosis of limbic encephalitis caused by viral infection, acyclovir therapy was started. However, 10 days after admission, a right superior temporal quadrantanopia developed in the left eye. MRI detected abnormal intensity in the left optic nerve on short tau inversion recovery images. After three courses of steroid pulse therapy, the optic neuritis quickly improved and the patient was maintained on subsequent oral administration of prednisolone, without relapse for one year. The CSF was positive for anti-glutamate receptor (GluR) antibodies (GluN2B, GluN1, and GluD2); however, anti-N-methyl-D-aspartate receptor antibody was not detected in both serum and CSF with cell-based asseys. Compared to previously reported anti-GluR positive cases combined with optic neuritis, the clinical outcome of our patient was short, with good prognosis. Our results indicate that an autoimmune mechanism involving anti-GluR antibodies contributes to the pathogenesis of optic neuritis as well as limbic encephalitis. PMID:27001777

  16. Analysis of audio-vestibular assessment in acute low-tone hearing loss.

    PubMed

    Im, Gi Jung; Kim, Sung Kyun; Choi, June; Song, Jae Jun; Chae, Sung Won; Jung, Hak Hyun

    2016-07-01

    Conclusion This study demonstrated excellent hearing recovery following the combined treatment of diuretic and oral steroid, and electrocochleography (ECoG) was significantly higher than normal side. This study reports characteristics of acute low-tone hearing loss (ALHL) that show the greater low-tone hearing loss, the higher ECoG, and excellent recovery, even-though low-tone hearing loss is worse, which can be different compared with sudden deafness. Objective To analyze ALHL without vertigo, this study compared the ALHL group with all patients exhibiting low-tone hearing loss and ear fullness. Hearing changes and vestibular functions were analyzed. Materials and methods ALHL was defined as a mean hearing loss of ≥ 30 dB at 125, 250, and 500 Hz, and ≤ 20 dB at 2, 4, and 8 kHz. From 156 cases of low-tone hearing loss of more than 10 dB without vertigo, 31 met the ALHL criteria and were subjected to audio-vestibular assessments including PTA, ECoG, vestibular evoked myogenic potential (VEMP) testing, and caloric testing. Results In ALHL, low-tone hearing loss was 42.7 ± 9.5 dB, and 83.9% of ALHL significantly recovered by more than 10 dB. The ECoG in ALHL was 0.334 ± 0.11 (higher than 0.25 ± 0.08 on the normal side) and ECoG abnormality was 35.5% (the greater low-tone hearing loss, the higher ECoG value). PMID:26963446

  17. [CHARACTERIZATION OF VESTIBULAR DISORDERS IN THE INJURED PERSONS WITH THE BRAIN CONCUSSION IN ACUTE PERIOD].

    PubMed

    Skobska, O E; Kadzhaya, N V; Andreyev, O A; Potapov, E V

    2015-04-01

    There were examined 32 injured persons, ageing (34.1 ± 1.3) yrs at average, for the brain commotion (BC). The adopted protocol SCAT-3 (Standardized Concussion Assessment Tool, 3rd ed.), DHI (Dizziness Handicap Inventory questionnaire), computer stabilography (KS) were applied for the vestibular disorders diagnosis. There was established, that in acute period of BC a dyssociation between regression of objective neurological symptoms and permanence of the BC indices occurs, what confirms a latent disorder of the balance function. Changes of basic indices of statokinesiography, including increase of the vibration amplitude enhancement in general centre of pressure in a saggital square and the BC square (235.3 ± 13.7) mm2 in a modified functional test of Romberg with the closed eyes is possible to apply as objective criteria for the BC diagnosis. PMID:26263645

  18. Multiple Sclerosis Risk after Optic Neuritis: Final Optic Neuritis Treatment Trial Follow-Up

    PubMed Central

    2008-01-01

    Objective Assess the risk of developing MS after optic neuritis and factors predictive of high and low risk Design Optic Neuritis Treatment Trial (ONTT) subjects enrolled between 1988 and 1991 were followed prospectively for 15 years with final examination in 2006. Setting Neurologic and ophthalmologic exams at 13 clinical sites Participants Three hundred eighty-nine subjects with acute optic neuritis Main Outcome Measure(s) Development of MS and neurologic disability assessment Results The cumulative probability of developing MS by 15 years was 50% (95% confidence interval 44% to 56%) and strongly related to presence of lesions on a non-contrast enhanced baseline brain MRI. Twenty-five percent of patients with no baseline brain MRI lesions developed MS during follow-up compared with 72% of patients with one or more lesions. After 10 years, the risk of developing MS was very low for patients without baseline lesions but remained substantial for those with lesions. Among patients without MRI lesions, baseline factors associated with a substantially lower risk of MS included male gender, optic disc swelling, and certain atypical features for optic neuritis. Conclusions The presence of brain MRI abnormalities at the time of an optic neuritis attack is a strong predictor of the 15-year risk of MS. In the absence of MRI lesions, male gender, optic disc swelling and atypical clinical features of optic neuritis are associated with a low likelihood of developing MS. This natural history information is important when considering prophylactic treatment for MS at the time of a first acute optic neuritis attack. PMID:18541792

  19. A Puzzle of Vestibular Physiology in a Meniere's Disease Acute Attack

    PubMed Central

    Martinez-Lopez, Marta; Manrique-Huarte, Raquel; Perez-Fernandez, Nicolas

    2015-01-01

    The aim of this paper is to present for the first time the functional evaluation of each of the vestibular receptors in the six semicircular canals in a patient diagnosed with Meniere's disease during an acute attack. A 54-year-old lady was diagnosed with left Meniere's disease who during her regular clinic review suffers an acute attack of vertigo, with fullness and an increase of tinnitus in her left ear. Spontaneous nystagmus and the results in the video head-impulse test (vHIT) are shown before, during, and after the attack. Nystagmus was initially left beating and a few minutes later an upbeat component was added. No skew deviation was observed. A decrease in the gain of the vestibuloocular reflex (VOR) and the presence of overt saccades were observed when the stimuli were in the plane of the left superior semicircular canal. At the end of the crisis nystagmus decreased and vestibuloocular reflex returned to almost normal. A review of the different possibilities to explain these findings points to a hypothetical utricular damage. PMID:26167320

  20. Characterization of pulse amplitude and pulse rate modulation for a human vestibular implant during acute electrical stimulation

    NASA Astrophysics Data System (ADS)

    Nguyen, T. A. K.; DiGiovanna, J.; Cavuscens, S.; Ranieri, M.; Guinand, N.; van de Berg, R.; Carpaneto, J.; Kingma, H.; Guyot, J.-P.; Micera, S.; Perez Fornos, A.

    2016-08-01

    Objective. The vestibular system provides essential information about balance and spatial orientation via the brain to other sensory and motor systems. Bilateral vestibular loss significantly reduces quality of life, but vestibular implants (VIs) have demonstrated potential to restore lost function. However, optimal electrical stimulation strategies have not yet been identified in patients. In this study, we compared the two most common strategies, pulse amplitude modulation (PAM) and pulse rate modulation (PRM), in patients. Approach. Four subjects with a modified cochlear implant including electrodes targeting the peripheral vestibular nerve branches were tested. Charge-equivalent PAM and PRM were applied after adaptation to baseline stimulation. Vestibulo-ocular reflex eye movement responses were recorded to evaluate stimulation efficacy during acute clinical testing sessions. Main results. PAM evoked larger amplitude eye movement responses than PRM. Eye movement response axes for lateral canal stimulation were marginally better aligned with PRM than with PAM. A neural network model was developed for the tested stimulation strategies to provide insights on possible neural mechanisms. This model suggested that PAM would consistently cause a larger ensemble firing rate of neurons and thus larger responses than PRM. Significance. Due to the larger magnitude of eye movement responses, our findings strongly suggest PAM as the preferred strategy for initial VI modulation.

  1. Atypical Optic Neuritis.

    PubMed

    Gaier, Eric D; Boudreault, Katherine; Rizzo, Joseph F; Falardeau, Julie; Cestari, Dean M

    2015-12-01

    Classic demyelinative optic neuritis is associated with multiple sclerosis and typically carries a good prognosis for visual recovery. This disorder is well characterized with respect to its presentation and clinical features by baseline data obtained through the optic neuritis treatment trial and numerous other studies. Atypical optic neuritis entails clinical manifestations that deviate from this classic pattern of features. Clinical signs and symptoms that deviate from the typical presentation should prompt consideration of less common etiologies. Atypical features to consider include lack of pain, simultaneous or near-simultaneous onset, lack of response to or relapse upon tapering from corticosteroids, or optic nerve head or peripapillary hemorrhages. The most important alternative etiologies to consider and the steps towards their respective diagnostic evaluations are suggested for these atypical features. PMID:26467052

  2. The mixed blessing of treating symptoms in acute vestibular failure--evidence from a 4-aminopyridine experiment.

    PubMed

    Beck, Roswitha; Günther, Lisa; Xiong, Guoming; Potschka, Heidrun; Böning, Guido; Bartenstein, Peter; Brandt, Thomas; Jahn, Klaus; Dieterich, Marianne; Strupp, Michael; la Fougère, Christian; Zwergal, Andreas

    2014-11-01

    Early symptomatic treatment of acute unilateral vestibulopathy is thought to impede the course of ensuing central vestibular compensation (VC). Despite the great clinical importance of this hypothesis there is no experimental evidence of its validity. The present study addressed this question by investigating the direct effect of 4-aminopyridine (4-AP) on ocular motor and postural symptoms in acute unilateral vestibulopathy as well as its long-term consequences for VC in a rat model of chemical unilateral labyrinthectomy (UL). After UL, one group of Sprague-Dawley rats was treated with 4-AP p.o. (1mg/kg/day), another with 0.9% NaCl solution p.o. for 3days. Behavioural testing for symptoms of vestibular tone imbalance was done 1day before and 1, 2, 3, 5, 7, 9, 15, 21, and 30days after UL. In addition, sequential whole-brain [(18)F]-FDG-μPET was performed before and 1, 3, 7, 15, and 30days after UL to examine and visualize 4-AP-induced modulation of VC. Administration of 4-AP on days 1-3 significantly improved postural imbalance 2h after administration compared to that in controls. This effect was only transient. Remarkably, the 4-AP group had a prolonged and impaired course of postural compensation compared to that of controls. The μPET revealed a significant increase of regional cerebral glucose metabolism (rCGM) in the vestibulocerebellum 2h after administration of 4-AP. However, the 4-AP group exhibited a persistent asymmetry of rCGM after day 3 in the vestibular nuclei and posterolateral thalami. In conclusion, this study confirms the hypothesis that early pharmacological abatement of vestibular symptoms impedes VC. PMID:25157903

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

    PubMed Central

    Tighilet, Brahim; Mourre, Christiane; Lacour, Michel

    2014-01-01

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

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

    PubMed

    Tighilet, Brahim; Mourre, Christiane; Lacour, Michel

    2014-01-01

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

  5. Vestibular Neuronitis

    MedlinePlus

    ... Prevent Painful Swimmer's Ear Additional Content Medical News Vestibular Neuronitis By Lawrence R. Lustig, MD NOTE: This ... Drugs Herpes Zoster Oticus Meniere Disease Purulent Labyrinthitis Vestibular Neuronitis Vestibular neuronitis is a disorder characterized by ...

  6. Optic Nerve Sheath Meningioma Masquerading as Optic Neuritis

    PubMed Central

    Alroughani, R.; Behbehani, R.

    2016-01-01

    Optic neuritis is a common presentation of demyelinating disorders such as multiple sclerosis. It typically presents with acute painful monocular vision loss, whereas chronic optic neuropathy can be caused by compressive lesions along the anterior visual pathway, genetic, toxic, or nutritional causes. We report an unusual presentation mimicking optic neuritis, which was subsequently diagnosed as optic nerve sheath meningioma (ONSM). Misinterpretation of white matter lesions on MRI of brain and the failure to image the optic nerves at the time of acute loss of vision led to the misdiagnosis of optic neuritis in this case. A comprehensive accurate history and ordering the appropriate imaging modality remain paramount in diagnosing progressive visual deterioration. PMID:26904329

  7. Optic Nerve Sheath Meningioma Masquerading as Optic Neuritis.

    PubMed

    Alroughani, R; Behbehani, R

    2016-01-01

    Optic neuritis is a common presentation of demyelinating disorders such as multiple sclerosis. It typically presents with acute painful monocular vision loss, whereas chronic optic neuropathy can be caused by compressive lesions along the anterior visual pathway, genetic, toxic, or nutritional causes. We report an unusual presentation mimicking optic neuritis, which was subsequently diagnosed as optic nerve sheath meningioma (ONSM). Misinterpretation of white matter lesions on MRI of brain and the failure to image the optic nerves at the time of acute loss of vision led to the misdiagnosis of optic neuritis in this case. A comprehensive accurate history and ordering the appropriate imaging modality remain paramount in diagnosing progressive visual deterioration. PMID:26904329

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

    PubMed

    Murofushi, Toshihisa

    2016-08-01

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

  9. Vestibular recruitment

    NASA Technical Reports Server (NTRS)

    Tsemakhov, S. G.

    1980-01-01

    Vestibular recruitment is defined through the analysis of several references. It is concluded that vestibular recruitment is an objective phenomenon which manifests itself during the affection of the vestibular receptor and thus serves as a diagnostic tool during affection of the vestibular system.

  10. Corticosteroids for treating optic neuritis

    PubMed Central

    Gal, Robin L; Vedula, Satyanarayana S; Beck, Roy

    2014-01-01

    Background Optic neuritis is an inflammatory disease of the optic nerve. It occurs more commonly in women than in men. Usually presenting with an abrupt loss of vision, recovery of vision is almost never complete. Closely linked in pathogenesis to multiple sclerosis, it may be the initial manifestation for this condition. In certain patients, no underlying cause can be found. Objectives To assess the effects of corticosteroids on visual recovery of patients with acute optic neuritis. Search methods We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 1), MEDLINE (January 1950 to February 2012), EMBASE (January 1980 to February 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to February 2012), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 21 February 2012. We also searched reference lists of identified trial reports to find additional trials. Selection criteria We included randomized trials that evaluated corticosteroids, in any form, dose or route of administration, in people with acute optic neuritis. Data collection and analysis Two authors independently extracted the data on methodological quality and outcomes for analysis. Main results We included six randomized trials which included a total of 750 participants. Two trials evaluated low dose oral corticosteroids while one trial evaluated low dose intravenous corticosteroids across two treatment arms and two trials evaluated a higher dose of intravenous corticosteroids. One three-arm trial evaluated low-dose oral corticosteroids and high-dose intravenous corticosteroids against placebo. Trials evaluating oral

  11. Masquerading optic neuritis.

    PubMed

    McVeigh, Katherine; Vakros, Georgios; Girgis, Rafik

    2015-01-01

    A 54-year-old woman presented to the ophthalmology emergency department with a 10-day history of blurred vision. The best-corrected visual acuities and Ishihara colour vision were bilaterally reduced with a left relative afferent pupillary defect. Slit-lamp examination was otherwise normal. Retrobulbar optic neuritis (ON) was presumed as she had suffered with this previously and was known to have multiple sclerosis (MS). She was recalled the following week for visual field (VF) testing, which was not available at the time of presentation. VFs demonstrated an incongruous left homonymous hemianopia. She was immediately referred to the medical team to investigate for a stroke, which was subsequently excluded. Thereafter, a trial of pulsed methylprednisolone was commenced, resulting in near complete resolution of the hemianopia. This case demonstrates not only the importance of VF testing, but also how ON may present with any field defect, including mimicking a stroke, a point valuable to ophthalmologists and medics alike. PMID:26240099

  12. Vestibular Hyperacusis

    MedlinePlus

    ... is a Top Rated Nonprofit! Volunteer. Donate. Review. Vestibular Hyperacusis Are you sensitive to certain sounds? Hyperacusis ... parade to a person with hyperacusis. Cochlear vs. vestibular hyperacusis With cochlear hyperacusis, subjects feel ear pain, ...

  13. Idiopathic brachial neuritis in a child: A case report and review of the literature

    PubMed Central

    Jain, Shikha; Bhatt, Girish Chandra; Rai, Nirendra; Bhan, Bhavna Dhingra

    2014-01-01

    Brachial neuritis is a rare disease in children, affecting mainly the lower motor neurons of the brachial plexus and/or individual nerves or nerve branches. We report a case of idiopathic brachial plexus neuritis in a 2½-year-old female child admitted with acute respiratory distress and given antibiotic therapy following which she developed weakness of the left hand. She was diagnosed as a case of idiopathic brachial plexus neuritis and was given supportive care. Although, the association with antibiotic therapy in this case could be incidental, indeed it is intriguing and requires further studies. PMID:25624937

  14. Idiopathic brachial neuritis in a child: A case report and review of the literature.

    PubMed

    Jain, Shikha; Bhatt, Girish Chandra; Rai, Nirendra; Bhan, Bhavna Dhingra

    2014-01-01

    Brachial neuritis is a rare disease in children, affecting mainly the lower motor neurons of the brachial plexus and/or individual nerves or nerve branches. We report a case of idiopathic brachial plexus neuritis in a 2½-year-old female child admitted with acute respiratory distress and given antibiotic therapy following which she developed weakness of the left hand. She was diagnosed as a case of idiopathic brachial plexus neuritis and was given supportive care. Although, the association with antibiotic therapy in this case could be incidental, indeed it is intriguing and requires further studies. PMID:25624937

  15. Pediatric optic neuritis.

    PubMed

    Yeh, E Ann; Graves, Jennifer S; Benson, Leslie A; Wassmer, Evangeline; Waldman, Amy

    2016-08-30

    Optic neuritis (ON) is a common presenting symptom in pediatric CNS demyelinating disorders and may be associated with dramatic visual loss. Knowledge regarding clinical presentation, associated diseases, therapy, and outcomes in ON in children has grown over the past decade. These studies have shown that younger children (<10 years of age) are more likely to present with bilateral ON and older children with unilateral ON. Furthermore, studies focusing on visual recovery have shown excellent recovery of high-contrast visual acuity in the majority of children, but functional and structural studies have shown evidence of irreversible injury and functional decline after ON in children. Although randomized controlled treatment trials have not been performed in children and adolescents with ON, standard of care suggests that the use of high-dose pulse steroids is safe and likely effective. This article reviews current knowledge about the clinical presentation and management of pediatric ON, with attention to associated syndromes and evaluative tools that may inform diagnosis and interventions. PMID:27572862

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

    PubMed

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

    2007-04-01

    Dynamic changes of deficits in canal and otolith vestibulo-ocular reflexes (VORs) to high acceleration, eccentric yaw rotations were investigated in five subjects aged 25-65 years before and at frequent intervals 3-451 days following unilateral vestibular deafferentation (UVD) due to labyrinthectomy or vestibular neurectomy. Eye and head movements were recorded using magnetic search coils during transients of directionally random, whole-body rotation in darkness at peak acceleration 2,800 degrees/s2. Canal VORs were characterized during rotation about a mid-otolith axis, viewing a target 500 cm distant until rotation onset in darkness. Otolith VOR responses were characterized by the increase in VOR gain during identical rotation about an axis 13 cm posterior to the otoliths, initially viewing a target 15 cm distant. Pre-UVD canal gain was directionally symmetrical, averaging 0.87 +/- 0.02 (+/-SEM). Contralesional canal gain declined from pre-UVD by an average of 22% in the first 3-5 days post-UVD, before recovering to an asymptote of close 90% of pre-UVD level at 1-3 months. This recovery corresponded to resolution of spontaneous nystagmus. Ipsilesional gain declined to 59%, and showed no consistent recovery afterwards. Pre-UVD otolith gain was directionally symmetrical, averaging 0.56 +/- 0.02. Immediately after UVD, the contralesional otolith gain declined to 0.30 +/- 0.02, and did not recover. Ipsilesional otolith gain declined profoundly to 0.08 +/- 0.03 (P < 0.01), and never recovered. In contrast to the modest and directionally symmetrical effect of UVD on the human otolith VOR during pure translational acceleration, otolith gain during eccentric yaw rotation exhibited a profound and lasting deficit that might be diagnostically useful in lateralizing otolith pathology. Most recovery of the human canal gain to high acceleration transients following UVD is for contralesional head rotation, occurring within 3 months as spontaneous nystagmus resolves. PMID

  17. Prediction of Short-Term Outcome in Acute Superior Vestibular Nerve Failure: Three-Dimensional Video-Head-Impulse Test and Caloric Irrigation

    PubMed Central

    Rambold, Holger A.

    2015-01-01

    This retrospective study examines acute unilateral vestibular failure (up to seven days after onset) with modern vestibular testing (caloric irrigation and video-head-impulse test, vHIT) in 54 patients in order to test if the short-term outcome of the patients depends on the lesion pattern defined by the two tests. Patients were grouped according to a pathological unilateral caloric weakness without a pathological vHIT: group I; additional a pathological vHIT of the lateral semicircular canal (SCC): group II; and an additional pathological vHIT of the anterior SCC: group III. Patients with involvement of the posterior SCC were less frequent and not included in the analysis. Basic parameters, such as age of the subjects, days after symptom onset, gender, side of the lesion, treatment, and dizziness handicap inventory, were not different in groups I to III. The frequency of pathological clinical findings and pathological quantified measurements increased from groups I to III. The outcome parameter “days spent in the hospital” was significantly higher in group III compared to group I. The analysis shows that differential vestibular testing predicts short-term outcome of the patients and might be in future important to treat and coach patients with vestibular failure. PMID:26649042

  18. Vestibular compensation and vestibular rehabilitation. Current concepts and new trends.

    PubMed

    Deveze, A; Bernard-Demanze, L; Xavier, F; Lavieille, J-P; Elziere, M

    2014-01-01

    The aim of this review is to present the current knowledge of the mechanisms underlying the vestibular compensation and demonstrating how the vestibular rehabilitation is conducted to help the recovery of balance function. Vestibular rehabilitation is based on improving the natural phenomenon called vestibular compensation that occurs after acute vestibular disturbance or chronic and gradual misbalance. Central compensation implies three main mechanisms namely adaptation, substitution and habituation. The compensation, aided by the rehabilitation aimed to compensate and/or to correct the underused or misused of the visual, proprioceptive and vestibular inputs involved in the postural control. As the strategy of equilibration is not corrected, the patient is incompletely cured and remains with inappropriate balance control with its significance on the risk of fall and impact on quality of life. The vestibular rehabilitation helps to correct inappropriate strategy of equilibrium or to accelerate a good but slow compensation phenomenon. Nowadays, new tools are more and more employed for the diagnosis of vestibular deficit (that may include various sources of impairment), the assessment of postural deficit, the control of the appropriate strategy as well to facilitate the efficiency of the rehabilitation especially in elderly people. PMID:24502905

  19. Peripheral neuritis due to isoniazid*

    PubMed Central

    Devadatta, S.; Gangadharam, P. R. J.; Andrews, R. H.; Fox, Wallace; Ramakrishnan, C. V.; Selkon, J. B.; Velu, S.

    1960-01-01

    It is well known that in the treatment of tuberculosis with isoniazid the complication of peripheral neuritis may arise. This complication is normally rare when small dosages of the drug are used, but a high incidence of the neuropathy has recently been observed in East Africa in a group of malnourished tuberculous patients receiving isoniazid in comparatively low dosage (4-6 mg/kg body-weight daily). The present paper reports on 20 cases of peripheral neuritis encountered in Madras, India, among 338 poorly nourished tuberculous patients during a trial of four isoniazid regimens, two of low and two of high dosage (3.9-5.5 and 7.8-9.6 mg/kg body-weight daily, respectively). Nineteen of the 20 cases occurred in the two groups of patients receiving the high dosage and these 19 patients were found to have a higher mean serum level of free isoniazid than the patients in the same groups who did not develop the complication. The authors consider that dosages of 7.8-9.6 mg/kg body-weight daily should not be used for the mass therapy of poorly nourished patients unless steps are taken to prevent the development of peripheral neuritis. Pyridoxine has been reported to be an effective preventive, but is too expensive for use on a large scale. This study indicates, however, that administration of the cheaper vitamin B complex might give satisfactory results and warrants further investigation. PMID:13722334

  20. [Vestibular paroxismia].

    PubMed

    Likhachev, S A; Mar'enko, I P; Antonenko, A I

    2013-01-01

    The objective of the present publication was to demonstrate a clinical case of peripheral vestibular paroxismia verified in a woman with the help of the MRI technique. Vestibular paroxismia is a relatively rare disease manifested in such characteristic signs and symptoms as sudden and short-lived episodes of dizziness, unstable gait, and the concomitant vegetative disorders accompanied as a rule by tympanophonia, impairment of hearing, and falls. In typical cases, the duration of such episodes varies from several minutes to a few days. A case of vestibular paroxismia associated with the lesion in the peripheral section of the vestibular system is described; it was caused by compression of the nerve by a blood vessel as shown by means of magnetic resonance imaging of cranial nerves. PMID:24429868

  1. Optic neuritis in pediatric population: a review in current tendencies of diagnosis and management.

    PubMed

    Pérez-Cambrodí, Rafael José; Gómez-Hurtado Cubillana, Aránzazu; Merino-Suárez, María L; Piñero-Llorens, David P; Laria-Ochaita, Carlos

    2014-01-01

    Optic neuritis is an inflammation of the optic nerve and may be related to different systemic conditions. The clinical presentation of this pathology usually includes sudden loss of visual acuity (VA) which may be unilateral or bilateral, visual field restriction, pain with eye movements, dyschromatopsia, a relative afferent pupillary defect and optic disk swelling. Optic neuritis in children has specific clinical features and a better prognosis than in adulthood. Although usually appears an underlying viral disease, the main concern for practitioners is the relationship of optic neuritis with multiple sclerosis. In addition to the classical techniques as magnetic resonance imaging (MRI), current tendencies of diagnosis for eye practitioners include new imaging devices as optical coherence tomography (OCT), useful to show a thinning of the retinal fibers layer (RFL) after the inflammatory episode. Regarding the management of these patients, short-term intravenous steroid dosages seem to be the best option to treat acute attacks characterized by a very poor bilateral VA. PMID:25000867

  2. Brachial neuritis following a corticosteroid injection.

    PubMed

    Robinson, Matthew; Fulcher, Mark

    2014-01-01

    This report presents a case of brachial neuritis following a subacromial corticosteroid injection. The patient developed an anterior interosseous neuropathy shortly after the injection, with no other trigger being identified. This neuropathy has unfortunately not shown any sign of recovery at 2 years. The authors propose that corticosteroid injection be added to the list of possible triggering events of brachial neuritis and highlight the frequent use of oral corticosteroids in its treatment. (1) The injection of local anaesthetic and corticosteroid should be considered as a potential trigger for brachial neuritis. (2) Brachial neuritis should be considered in the differential diagnosis for patients presenting with severe arm pain and weakness. (3) The nerves originating from the upper trunk of the brachial plexus are most commonly affected. (4) The anterior interosseous nerve is involved in one-third of cases. PMID:24596414

  3. Balance (or Vestibular) Rehabilitation

    MedlinePlus

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

  4. Vestibular tests in the selection of cosmonauts

    NASA Astrophysics Data System (ADS)

    Kubiczkowa, Janusza

    Vestibulo-vegetative disorders in cosmonauts and astronauts occurring during space flight compel otolaryngologists to search for vestibular tests enabling a precise evaluation of the activity of the vestibular apparatus and showing disposition to motion sickness. Otoneurological investigation of Polish candidates for cosmonaut status consisted of the following vestibular tests: caloric, rotatory, optokinetic, swinging torsion, statokinesimetric and vestibulo-vegetative. The value of various vestibular tests for aviation and space medicine is presented in this paper, taking into account the results of investigations of the equilibrium system with the group of pilots selected for space flight as well as extensive experience with candidates for the air service and also trained pilots and patients. The relatively frequent lack of correlation between the results of the applied tests, which renders difficult the proper evaluation of the equilibrium system, is emphasized in the paper. Finally, the results of investigations of acute habituation of the vestibular apparatus are discussed.

  5. Evaluation of Retinal Nerve Fiber Layer and Ganglion Cell Complex in Patients with Optic Neuritis or Neuromyelitis Optica Spectrum Disorders Using Optical Coherence Tomography in a Chinese Cohort

    PubMed Central

    Tian, Guohong; Li, Zhenxin; Zhao, Guixian; Feng, Chaoyi; Li, Mengwei; Huang, Yongheng; Sun, Xinghuai

    2015-01-01

    We evaluate a cohort of optic neuritis and neuromyelitis optica (NMO) spectrum disorders patients in a territory hospital in China. The peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell complex (GCC) were measured using spectral-domain OCT after 6 months of acute onset. The results showed that both the peripapillary RNFL and macular GCC were significantly thinner in all optic neuritis subtypes compared to controls. In addition, the recurrent optic neuritis and NMO groups showed more severe damage on the RNFL and GCC pattern. PMID:26649191

  6. 38 CFR 4.123 - Neuritis, cranial or peripheral.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2013-07-01 2013-07-01 false Neuritis, cranial or....123 Neuritis, cranial or peripheral. Neuritis, cranial or peripheral, characterized by loss of... the scale provided for injury of the nerve involved, with a maximum equal to severe,...

  7. 38 CFR 4.123 - Neuritis, cranial or peripheral.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2014-07-01 2014-07-01 false Neuritis, cranial or....123 Neuritis, cranial or peripheral. Neuritis, cranial or peripheral, characterized by loss of... the scale provided for injury of the nerve involved, with a maximum equal to severe,...

  8. 38 CFR 4.123 - Neuritis, cranial or peripheral.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2012-07-01 2012-07-01 false Neuritis, cranial or....123 Neuritis, cranial or peripheral. Neuritis, cranial or peripheral, characterized by loss of... the scale provided for injury of the nerve involved, with a maximum equal to severe,...

  9. 38 CFR 4.123 - Neuritis, cranial or peripheral.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2011-07-01 2011-07-01 false Neuritis, cranial or....123 Neuritis, cranial or peripheral. Neuritis, cranial or peripheral, characterized by loss of... the scale provided for injury of the nerve involved, with a maximum equal to severe,...

  10. 38 CFR 4.123 - Neuritis, cranial or peripheral.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Neuritis, cranial or....123 Neuritis, cranial or peripheral. Neuritis, cranial or peripheral, characterized by loss of... the scale provided for injury of the nerve involved, with a maximum equal to severe,...

  11. The vestibular system

    NASA Technical Reports Server (NTRS)

    Graybiel, A.

    1973-01-01

    The end organs, central nervous system connections, and static and dynamic characteristics of the vestibular system are presented. Vestibular servation in man and vestibular side effect prevention from space missions involving artificial gravity generation are also considered. Vestibular models and design criteria for rotating space vehicles are appended.

  12. Intravenous immunoglobulin and interferon: successful treatment of optic neuritis in pediatric multiple sclerosis.

    PubMed

    Spalice, Alberto; Properzi, Enrico; Lo Faro, Valentina; Acampora, Barbara; Iannetti, Paola

    2004-08-01

    Optic neuritis is a common clinical condition that causes loss of vision. It can be clinically isolated or can occur as one of the manifestations of multiple sclerosis. Multiple sclerosis is a severe disabling demyelinating disease of the central nervous system, which is rare among children. The treatment of optic neuritis has been investigated in several trials, the results of which have shown that corticosteroids speed up the recovery of vision without affecting the final visual outcome. Treatment of neurologic disorders with intravenous immunoglobulin is an increasing feature of our practice for an expanding range of indications, including multiple sclerosis. Owing to its anti-inflammatory properties, intravenous immunoglobulin can be beneficial in the treatment of acute relapses and in the prevention of new relapses of multiple sclerosis. To our knowledge, there is only one experience of treatment of optic neuritis with intravenous immunoglobulin in multiple sclerosis, even if therapeutic trials are used in the therapy of multiple sclerosis. We report on a girl with optic neuritis and multiple sclerosis in whom treatment with intravenous immunoglobulin at first alone and subsequently associated with interferon achieved great improvement in visual acuity. PMID:15605474

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

    SciTech Connect

    Vignaux, G.; Chabbert, C.; Gaboyard-Niay, S.; Travo, C.; Machado, M.L.; Denise, P.; Comoz, F.; Hitier, M.; Landemore, G.; Philoxène, B.; Besnard, S.

    2012-01-01

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

  14. Alexander’s Law in Patients with Acute Vestibular Tone Asymmetry—Evidence for Multiple Horizontal Neural Integrators

    PubMed Central

    Hegemann, S.; Straumann, D.

    2007-01-01

    Alexander’s law (AL) states that the slow-phase velocity of spontaneous nystagmus of peripheral vestibular origin is dependent on horizontal gaze position, with greater velocity when gaze is directed in the fast-phase direction. AL is thought to be a compensatory reaction resulting from adaptive changes in the horizontal ocular motor neural integrator. Until now, only horizontal eye movements have been investigated with respect to AL. Because spontaneous nystagmus usually includes vertical and torsional components, we asked whether horizontal gaze changes would have an effect on the 3D drift of spontaneous nystagmus and, thus, on the vertical/torsional neural integrator. We hypothesized that AL reduces all nystagmus components proportionally. Moreover, we questioned the classical theory of a single bilaterally organized horizontal integrator and searched for nonlinearities of AL implying a network of multiple integrators. Using dual scleral search coils, we measured AL in 17 patients with spontaneous nystagmus. Patients followed a pulsed laser dot at eye level jumping in 5° steps along the horizontal meridian between 25° right and left in otherwise complete darkness. AL was observed in 15 of 17 patients. Whereas individual patients typically showed a change of 3D-drift direction at different horizontal eye positions, the average change in direction was not different from zero. The strength of AL (= rate of change of total velocity with gaze position) correlated with nystagmus slow-phase velocity (Spearman’s rho = 0.5; p < 0.05) and, on average, did not change the 3D nystagmus drift direction. In general, eye velocity did not vary linearly with eye position. Rather, there was a stronger dependence of velocity on horizontal position when subjects looked in the slow-phase direction compared to the fast-phase direction. We conclude that the theory of a simple leak of a single horizontal neural integrator is not sufficient to explain all aspects of AL

  15. Prospective Study on Retinal Nerve Fibre Layer Thickness Changes in Isolated Unilateral Retrobulbar Optic Neuritis

    PubMed Central

    Yau, Gordon S. K.; Lee, Jacky W. Y.; Lau, Patrick P. K.; Tam, Victor T. Y.; Wong, Winnie W. Y.; Yuen, Can Y. F.

    2013-01-01

    Purpose. To investigate the retinal nerve fibre layer (RNFL) thickness after unilateral acute optic neuritis using optical coherence tomography (OCT). Patients and Methods. This prospective cohort study recruited consecutive patients with a first episode of isolated, unilateral acute optic neuritis. RNFL thickness and visual acuity (VA) of the attack and normal fellow eye were measured at presentation and 3 months in both the treatment and nontreatment groups. Results. 11 subjects received systemic steroids and 9 were treated conservatively. The baseline RNFL thickness was similar in the attack and fellow eye (P ≥ 0.4). At 3 months, the attack eye had a thinner temporal (P = 0.02) and average (P = 0.05) RNFL compared to the fellow eye. At 3 months, the attack eye had significant RNFL thinning in the 4 quadrants and average thickness (P ≤ 0.0002) compared to baseline. The RNFL thickness between the treatment and nontreatment groups was similar at baseline and 3 months (P ≥ 0.1). Treatment offered better VA at 3 months (0.1 ± 0.2 versus 0.3 ± 0.2 LogMAR, P = 0.04). Conclusion. Generalized RNFL thinning occurred at 3 months after a first episode of acute optic neuritis most significantly in the temporal quadrant and average thickness. Visual improvement with treatment was independent of RNFL thickness. PMID:24459442

  16. Lipoic Acid Decreases Inflammation and Confers Neuroprotection in Experimental Autoimmune Optic Neuritis

    PubMed Central

    Chaudhary, Priya; Marracci, Gail; Yu, Xiaolin; Galipeau, Danielle; Morris, Brooke; Bourdette, Dennis

    2016-01-01

    Lipoic acid (LA) is an antioxidant that is effective in treating experimental autoimmune encephalomyelitis (EAE), a model for multiple sclerosis (MS). C57BL/6 mice with EAE develop experimental autoimmune optic neuritis (EAON), which models acute optic neuritis in humans. Here we determined whether LA is therapeutically effective in EAON. We immunized C57BL/6 mice with MOG 35–55 peptide. Mice received either daily subcutaneous injections of LA (100 mg/kg) or saline in early or late suppression paradigms. In the early suppression paradigm, optic nerve cross sections showed 14.9 ± 3.8% (mean ± SEM) damage in mice receiving saline (n = 7) and 2.0 ± 0.4 % damage in mice given LA (n = 7, p = 0.001). In the late suppression paradigm, optic nerve sections showed 24.6 ± 3.5% damage in mice treated with saline (n = 7) and 8.4 ± 2.5% in mice treated with LA (n = 7, p = 0.004). Thus a dramatic reduction in axonal injury was seen after LA administration in both experimental paradigms. Compared with saline treated mice with EAON, optic nerves from mice receiving LA had significantly fewer CD4+ and CD11b+ cells in both paradigms. This study provides a rationale for investigating the therapeutic efficacy of LA in acute optic neuritis in humans. PMID:21215462

  17. A case of almost painless herpes zoster presenting with symptoms of cystitis, penile numbness, and acute vestibular failure.

    PubMed

    Al-Sardar, Hussain

    2013-01-01

    Herpes zoster (shingles) is an acute, painful, vesicular, and cutaneous eruption caused by varicella zoster virus, the same virus which causes chicken pox. It is due to the reactivation of the virus which remains dormant in sensory ganglions following chicken pox. It is usually confined to a single dermatome but may involve 2-3 dermatomes. Typically, it is a unilateral lesion which can affect both cranial and peripheral nerves. It is usually a self-limiting disease; however, it may cause significant morbidity especially in the elderly. It is more common in older people and individuals with immunocompromised conditions. Antiviral drugs can shorten the duration and the severity of the illness and need to be started as soon as possible after the appearance of the rash. Gabapentin and tricyclic antidepressant are effective in postherpetic neuralgia. Vaccine can reduce the risk of infection and its associated pain. Typically, it occurs once in a lifetime, but some individuals may have more than one episode. PMID:24251046

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

    PubMed Central

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

    2016-01-01

    patient to understand the goals of the program and how to manage and progress themselves independently. As a general guide, persons without significant comorbidities that affect mobility and with acute or subacute unilateral vestibular hypofunction may need once a week supervised sessions for 2 to 3 weeks; persons with chronic unilateral vestibular hypofunction may need once a week sessions for 4 to 6 weeks; and persons with bilateral vestibular hypofunction may need once a week sessions for 8 to 12 weeks. In addition to supervised sessions, patients are provided a daily home exercise program. Disclaimer: These recommendations are intended as a guide for physical therapists and clinicians to optimize rehabilitation outcomes for persons with peripheral vestibular hypofunction undergoing vestibular rehabilitation. Video Abstract available for more insights from the author (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A124). PMID:26913496

  19. Review of book vestibular crises

    NASA Technical Reports Server (NTRS)

    Blagoveshchenskaya, N. S.

    1980-01-01

    The etiology, pathogenesis, clinical practice, treatment and rehabilitation of patients with vestibular crises is discussed. Classifications for vestibular disorders are given. Information on the frequency of vestibular crises is given.

  20. Surgical Procedures for Vestibular Dysfunction

    MedlinePlus

    ... Rated Nonprofit! Volunteer. Donate. Review. Surgical Procedures for Vestibular Dysfunction When is surgery necessary? When medical treatment ... organ (cochlea) is also sacrificed with this procedure. Vestibular nerve section A vestibular nerve section is a ...

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

    NASA Technical Reports Server (NTRS)

    Perachio, Adrian A. (Principal Investigator)

    1996-01-01

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

  2. Vestibular humanoid postural control.

    PubMed

    Mergner, Thomas; Schweigart, Georg; Fennell, Luminous

    2009-01-01

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

  3. Dimethyl Fumarate Ameliorates Lewis Rat Experimental Autoimmune Neuritis and Mediates Axonal Protection

    PubMed Central

    Pitarokoili, Kalliopi; Ambrosius, Björn; Meyer, Daniela; Schrewe, Lisa; Gold, Ralf

    2015-01-01

    Background Dimethyl fumarate is an immunomodulatory and neuroprotective drug, approved recently for the treatment of relapsing-remitting multiple sclerosis. In view of the limited therapeutic options for human acute and chronic polyneuritis, we used the animal model of experimental autoimmune neuritis in the Lewis rat to study the effects of dimethyl fumarate on autoimmune inflammation and neuroprotection in the peripheral nervous system. Methods and Findings Experimental autoimmune neuritis was induced by immunization with the neuritogenic peptide (amino acids 53–78) of P2 myelin protein. Preventive treatment with dimethyl fumarate given at 45 mg/kg twice daily by oral gavage significantly ameliorated clinical neuritis by reducing demyelination and axonal degeneration in the nerve conduction studies. Histology revealed a significantly lower degree of inflammatory infiltrates in the sciatic nerves. In addition, we detected a reduction of early signs of axonal degeneration through a reduction of amyloid precursor protein expressed in axons of the peripheral nerves. This reduction correlated with an increase of nuclear factor (erythroid derived 2)-related factor 2 positive axons, supporting the neuroprotective potential of dimethyl fumarate. Furthermore, nuclear factor (erythroid derived 2)-related factor 2 expression in Schwann cells was only rarely detected and there was no increase of Schwann cells death during EAN. Conclusions We conclude that immunmodulatory and neuroprotective dimethyl fumarate may represent an innovative therapeutic option in human autoimmune neuropathies. PMID:26618510

  4. Otolith-Canal Convergence in Vestibular Nuclei Neurons

    NASA Technical Reports Server (NTRS)

    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.

  5. A case of multiple evanescent white dot syndrome misdiagnosed as optic neuritis: Differential diagnosis for the neurologist

    PubMed Central

    Pellegrini, Francesco; Interlandi, Emanuela

    2016-01-01

    A 25-year-old female presented to a local hospital for acute onset of a central scotoma in the left visual field. She was visited by the neurologist, and a diagnosis of left retrobulbar optic neuritis was made. Magnetic resonance imaging scan was normal. Ophthalmic examination revealed a multiple evanescent white dot syndrome. After a description of the case, a brief differential diagnosis between these two entities is made. The neurologist should be aware of this uncommon condition. PMID:27114663

  6. Vestibular compensation: the neuro-otologist's best friend.

    PubMed

    Lacour, Michel; Helmchen, Christoph; Vidal, Pierre-Paul

    2016-04-01

    Why vestibular compensation (VC) after an acute unilateral vestibular loss is the neuro-otologist's best friend is the question at the heart of this paper. The different plasticity mechanisms underlying VC are first reviewed, and the authors present thereafter the dual concept of vestibulo-centric versus distributed learning processes to explain the compensation of deficits resulting from the static versus dynamic vestibular imbalance. The main challenges for the plastic events occurring in the vestibular nuclei (VN) during a post-lesion critical period are neural protection, structural reorganization and rebalance of VN activity on both sides. Data from animal models show that modulation of the ipsilesional VN activity by the contralateral drive substitutes for the normal push-pull mechanism. On the other hand, sensory and behavioural substitutions are the main mechanisms implicated in the recovery of the dynamic functions. These newly elaborated sensorimotor reorganizations are vicarious idiosyncratic strategies implicating the VN and multisensory brain regions. Imaging studies in unilateral vestibular loss patients show the implication of a large neuronal network (VN, commissural pathways, vestibulo-cerebellum, thalamus, temporoparietal cortex, hippocampus, somatosensory and visual cortical areas). Changes in gray matter volume in these multisensory brain regions are structural changes supporting the sensory substitution mechanisms of VC. Finally, the authors summarize the two ways to improve VC in humans (neuropharmacology and vestibular rehabilitation therapy), and they conclude that VC would follow a "top-down" strategy in patients with acute vestibular lesions. Future challenges to understand VC are proposed. PMID:27083885

  7. Treatment of optic neuritis with erythropoietin (TONE): a randomised, double-blind, placebo-controlled trial—study protocol

    PubMed Central

    Diem, Ricarda; Molnar, Fanni; Beisse, Flemming; Gross, Nikolai; Drüschler, Katharina; Heinrich, Sven P; Joachimsen, Lutz; Rauer, Sebastian; Pielen, Amelie; Sühs, Kurt-Wolfram; Linker, Ralf Andreas; Huchzermeyer, Cord; Albrecht, Philipp; Hassenstein, Andrea; Aktas, Orhan; Guthoff, Tanja; Tonagel, Felix; Kernstock, Christoph; Hartmann, Kathrin; Kümpfel, Tania; Hein, Katharina; van Oterendorp, Christian; Grotejohann, Birgit; Ihorst, Gabriele; Maurer, Julia; Müller, Matthias; Volkmann, Martin; Wildemann, Brigitte; Platten, Michael; Wick, Wolfgang; Heesen, Christoph; Schiefer, Ulrich; Wolf, Sebastian; Lagrèze, Wolf A

    2016-01-01

    Introduction Optic neuritis leads to degeneration of retinal ganglion cells whose axons form the optic nerve. The standard treatment is a methylprednisolone pulse therapy. This treatment slightly shortens the time of recovery but does not prevent neurodegeneration and persistent visual impairment. In a phase II trial performed in preparation of this study, we have shown that erythropoietin protects global retinal nerve fibre layer thickness (RNFLT-G) in acute optic neuritis; however, the preparatory trial was not powered to show effects on visual function. Methods and analysis Treatment of Optic Neuritis with Erythropoietin (TONE) is a national, randomised, double-blind, placebo-controlled, multicentre trial with two parallel arms. The primary objective is to determine the efficacy of erythropoietin compared to placebo given add-on to methylprednisolone as assessed by measurements of RNFLT-G and low-contrast visual acuity in the affected eye 6 months after randomisation. Inclusion criteria are a first episode of optic neuritis with decreased visual acuity to ≤0.5 (decimal system) and an onset of symptoms within 10 days prior to inclusion. The most important exclusion criteria are history of optic neuritis or multiple sclerosis or any ocular disease (affected or non-affected eye), significant hyperopia, myopia or astigmatism, elevated blood pressure, thrombotic events or malignancy. After randomisation, patients either receive 33 000 international units human recombinant erythropoietin intravenously for 3 consecutive days or placebo (0.9% saline) administered intravenously. With an estimated power of 80%, the calculated sample size is 100 patients. The trial started in September 2014 with a planned recruitment period of 30 months. Ethics and dissemination TONE has been approved by the Central Ethics Commission in Freiburg (194/14) and the German Federal Institute for Drugs and Medical Devices (61-3910-4039831). It complies with the Declaration of Helsinki

  8. Permeability of the blood–brain barrier predicts conversion from optic neuritis to multiple sclerosis

    PubMed Central

    Modvig, Signe; Simonsen, Helle J.; Frederiksen, Jette L.; Larsson, Henrik B. W.

    2015-01-01

    Optic neuritis is an acute inflammatory condition that is highly associated with multiple sclerosis. Currently, the best predictor of future development of multiple sclerosis is the number of T2 lesions visualized by magnetic resonance imaging. Previous research has found abnormalities in the permeability of the blood–brain barrier in normal-appearing white matter of patients with multiple sclerosis and here, for the first time, we present a study on the capability of blood–brain barrier permeability in predicting conversion from optic neuritis to multiple sclerosis and a direct comparison with cerebrospinal fluid markers of inflammation, cellular trafficking and blood–brain barrier breakdown. To this end, we applied dynamic contrast-enhanced magnetic resonance imaging at 3 T to measure blood–brain barrier permeability in 39 patients with monosymptomatic optic neuritis, all referred for imaging as part of the diagnostic work-up at time of diagnosis. Eighteen healthy controls were included for comparison. Patients had magnetic resonance imaging and lumbar puncture performed within 4 weeks of onset of optic neuritis. Information on multiple sclerosis conversion was acquired from hospital records 2 years after optic neuritis onset. Logistic regression analysis showed that baseline permeability in normal-appearing white matter significantly improved prediction of multiple sclerosis conversion (according to the 2010 revised McDonald diagnostic criteria) within 2 years compared to T2 lesion count alone. There was no correlation between permeability and T2 lesion count. An increase in permeability in normal-appearing white matter of 0.1 ml/100 g/min increased the risk of multiple sclerosis 8.5 times whereas having more than nine T2 lesions increased the risk 52.6 times. Receiver operating characteristic curve analysis of permeability in normal-appearing white matter gave a cut-off of 0.13 ml/100 g/min, which predicted conversion to multiple sclerosis with a

  9. A case of retrobulbar optic neuritis caused by duloxetine.

    PubMed

    Bicer, Tolga; Kosker, Mustafa; Celikay, Osman; Gurdal, Canan

    2016-09-01

    Psychotropic medications may cause many ocular adverse effects including toxic optic neuropathy. We present a unique case of a 44-year-old woman using duloxetine who presented with unilateral visual loss due to retrobulbar neuritis. Physicians and patients should be alerted to this potential side effect. To the best of our knowledge, this is the first case of developing retrobulbar neuritis related to duloxetine usage. PMID:26362493

  10. Paraneoplastic optic neuritis as the first manifestation of periampullary carcinoma

    PubMed Central

    Paul, Rudrajit; Ghosh, Asim K; Sinha, Avirup; Bhattacharya, Raja

    2015-01-01

    Paraneoplastic optic neuritis is a rare phenomenon that often presents as a diagnostic challenge. It has been mostly reported with small cell cancers or thymoma. Prompt treatment of the malignancy is the only effective therapy for the condition. Visual loss, once established usually becomes irreversible. We here report a case of paraneoplastic optic neuritis in a 40-year-old female with periampullary carcinoma. This is probably the first report of this association in the medical literature. PMID:25664276

  11. Relationship of optic neuritis to disease of the paranasal sinuses.

    PubMed

    Rothstein, J; Maisel, R H; Berlinger, N T; Wirtschafter, J D

    1984-11-01

    The relationship of paranasal sinusitis to optic neuritis remains an intriguing curiosity to both the otolaryngologist and the ophthalmologist. The literature is replete with anecdotal case reports of patients whose sinusitis appears to have caused optic neuritis. There is much speculation about the pathophysiological mechanisms which relate these two distinct disease entities. Five new cases are described which highlight distinct pathophysiologic routes through which paranasal sinus disease has caused optic neuritis. These include compressive optic neuropathy secondary to mucoceles and/or pyoceles; direct extension of sinus infection to the optic nerve from suppurative paranasal sinusitis; and, in one case, from osteomyelitis of the ethmoid and sphenoid sinuses. The usefulness of computerized axial tomography of the orbits and paranasal sinuses to evaluate optic neuritis and to elucidate in detail the pathophysiology of its relationship to disease of the paranasal sinuses is emphasized. Currently, optic neuritis is felt to be a rare complication of paranasal sinusitis. Paranasal sinus surgery is advocated in those cases where sinus suppuration is suspected, or when a compressive optic neuropathy is caused by a sinus mucocele or pyocele. Since in most cases, however, optic neuritis is self-limited, it is difficult to evaluate the results of surgery in circumstances other than those mentioned already. Continued careful evaluation, management, and documentation of this group of patients is necessary to help better define the relationship between these two disease entities. PMID:6492975

  12. Vestibular Schwannoma (Acoustic Neuroma) and Neurofibromatosis

    MedlinePlus

    ... Home » Health Info » Hearing, Ear Infections, and Deafness Vestibular Schwannoma (Acoustic Neuroma) and Neurofibromatosis On this page: ... more information about vestibular schwannomas? What is a vestibular schwannoma (acoustic neuroma)? Inner ear with vestibular schwannoma ( ...

  13. Medication (for Vestibular Disorders)

    MedlinePlus

    ... and should be carried out in every patient. Eye movement evaluation is one of the major windows in this respect because particular eye movements are evoked by particular vestibular conditions. A precise ...

  14. [Therapy of vestibular vertigo].

    PubMed

    Hamann, K F

    1993-05-01

    The non-surgical treatment of vestibular disorders must be based on current knowledge of vestibular pathophysiology. It is generally accepted that after vestibular lesions a self-repair mechanism exists that allows a more or less complete recovery. In cases of persisting vestibular complaints the physician's duty consists in stimulation of these pre-existing mechanisms. This can be done by physical exercises, as has been recommended since the work of Cawthorne and Cooksey in 1946. This concept is meanwhile supported by modern neurophysiological research. This article describes a short training program consisting of exercises for fixation during rotations, smooth pursuit, optokinetic nystagmus and motor learning mechanisms. Physical exercises can be reinforced by nootropic drugs. PMID:8335490

  15. Human vestibular evoked responses.

    PubMed

    Muñoz-Gamboa, C; Jiménez-Cruz, J

    1994-01-01

    The results of an experimental series dedicated to the acquisition of human vestibular evoked responses are presented. In these series, manual stimulation is applied to a normal group of subjects with rotational acceleration impulses. Every stimulus is large in magnitude and very short in duration, producing small head movements of only a few degrees through a specially designed head immobilization helmet. Results correspond to middle latency vestibular evoked responses. PMID:7968862

  16. Recovery from vestibular ototoxicity

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

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

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

    PubMed

    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

  18. Occurrence of Optic Neuritis and Cervical Cord Schwannoma with Charcot-Marie-Tooth Type 4B1 Disease

    PubMed Central

    Scott, Patrick; Bruwer, Zandre; Al-Kharusi, Khalsa; Meftah, Douja; Al-Murshedi, Fathiya

    2016-01-01

    Charcot-Marie-Tooth neuropathy type 4B1 (CMT4B1) disease is a rare subtype of CMT4 with reported association of facial weakness, vocal cord paresis, chest deformities, and claw hands. We report the unusual occurrence of optic neuritis and cervical cord schwannoma in a male individual with confirmed CMT4B1 disease. Sequencing of the MTMR2 gene revealed a novel nonsense homozygous mutation c.1768C>T (p.Gln590*). The mutation was identified in affected relatives of the proband and a second, apparently unrelated, family. The rare association of optic neuritis or schwannoma with genetically confirmed CMT1A has been individually observed, but never with recessive CMT. To the best of our knowledge, the occurrence of optic neuritis and cervical cord schwannoma in the same patient has never been reported with any form of CMT including CMT4B1. In similar cases, we recommend immediate medical attention to rule out the possibility of schwannomas in patients with all demyelinating CMT subtypes in case of the development of focal neurological signs or acute worsening of clinical status. PMID:27162595

  19. Cauda Equina Neuritis: A Chronic Idiopathic Polyneuritis in Two Horses

    PubMed Central

    Rousseaux, C. G.; Futcher, K. G.; Clark, E. G.; Naylor, J. M.

    1984-01-01

    Two cases of cauda equina neuritis are compared and contrasted. Neurological deficits of the tail and perineum were noted and functional deficits were seen in gait, urination, defecation and cranial nerve function. Lesions consisted of nonsuppurative inflammation of the nerve trunks and proliferation of the perineurium of the cauda equina. Cranial nerve involvement in one case supported a diagnosis of polyneuritis equi rather than cauda equina neuritis. The possible etiologies and pathogenesis of this disease are discussed. ImagesFigure 1.Figure 2.Figure 3.Figure 4. PMID:17422405

  20. Risk Factors for Idiopathic Optic Neuritis Recurrence

    PubMed Central

    Zhang, Yu-Jiao; Li, Kaijun; He, Jian-Feng

    2014-01-01

    Background Approximately 30–50% of idiopathic optic neuritis (ION) patients experience one or multiple episodes of recurrence. The aim of this study was to search for risk factors for ION recurrence. Methods Clinical data on hospitalized patients diagnosed with ION between January 2003 and January 2011 at the First Affiliated Hospital of Guangxi Medical University were retrospectively collected. Univariate and multivariate analyses were performed on factors that might cause ION recurrence. In total, 115 ION cases (32 recurrent and 83 non-recurrent cases) with complete data were analyzed. The length of the follow-up period ranged from 12 to 108 months (median: 42 months). Results The univariate analysis showed that the recurrence rate for unilateral ION was higher than that for bilateral ION (40% vs. 12%, p = 0.001). Underlying diseases had a significant impact on recurrence (p<0.001): the recurrence rates due to neuromyelitis optica (NMO), multiple sclerosis (MS), demyelinating lesions alone of the central nervous system, and unknown causes were 89%, 70%, 41%, and 8.7%, respectively. The multivariate analysis showed that the factors causing relatively high recurrence rates included NMO (odds ratio [OR], 73.5; 95% confidence interval [CI], 7.3 to 740.9), MS (OR, 33.9; 95% CI, 5.2 to 222.2), and demyelinating lesions alone (OR, 8.9; 95% CI, 2.3 to 34.4), unilateral involvement (OR, 5.7; 95% CI, 1.5 to 21.3), relatively low initial glucocorticoid dosage (equivalent to ≤100 mg prednisone/day) (OR, 4.3; 95% CI, 1.0 to 17.9). Conclusion Underlying diseases, laterality (unilateral or bilateral), and initial glucocorticoid dosage are important risk factors of ION recurrence. Clinical physicians are advised to treat ION patients with a sufficient dose of glucocorticoid in the initial treatment stage to reduce the recurrence risk. PMID:25255372

  1. Management of vestibular migraine.

    PubMed

    Bisdorff, Alexandre R

    2011-05-01

    Vestibular migraine is considered to be the second most common cause of vertigo and the most common cause of spontaneous episodic vertigo. The duration of attacks varies from seconds to days, usually lasting minutes to hours, and they mostly occur independently of headaches. Long-lasting individual attacks are treated with generic antivertiginous and antiemetic drugs. Specific antimigraine drugs are unlikely to be very effective for rescue. The mainstay of the management of vestibular migraine is prophylactic medication. To date, there are no controlled trials available; the body of knowledge builds on case series and retrospective or observational studies. Most drugs are also used for the prevention of migraine headaches. The choice of medication should be guided by its side effect profile and the comorbidities of patients. Betablockers such as propanolol or metoprolol are preferred in patients with hypertension but in the absence of asthma. Anticonvulsants include topiramate when patients are obese, valproic acid and lamotrigine. Lamotrigine is preferred if vertigo is more frequent than headaches. Calcium antagonists include verapamil and flunarizine. If patients have anxiety, tricyclic antidepressants such as amitryptiline or nortryptiline or SSRIs and benzodiazepines such as clonazepam are recommended. Acetazolamide is effective in rare genetic disorders related to migraine-like episodic ataxia; however, its place in vestibular migraine is still to be established. Nonpharmacological measures such as diet, sleep, hygiene and avoidance of triggers are recommended as they are for migraine. Vestibular rehabilitation might be useful when there are complications such as loss of confidence in balance or visual dependence. PMID:21694818

  2. The Vestibular Effects of Repeated Low-Level Blasts.

    PubMed

    Littlefield, Philip D; Pinto, Robin L; Burrows, Holly L; Brungart, Douglas S

    2016-01-01

    The objective of this study was to use a prospective cohort of United States Marine Corps (USMC) instructors to identify any acute or long-term vestibular dysfunction following repeated blast exposures during explosive breaching training. They were assessed in clinic and on location during training at the USMC Methods of Entry School, Quantico, VA. Subjects received comprehensive baseline vestibular assessments and these were repeated in order to identify longitudinal changes. They also received shorter assessments immediately following blast exposure in order to identify acute findings. The main outcome measures were the Neurobehavioral Symptom Inventory, vestibular Visual Analog Scale (VAS) of subjective vestibular function, videonystagmography (VNG), vestibular evoked myogenic potentials (VEMP), rotary chair (including the unilateral centrifugation test), computerized dynamic posturography, and computerized dynamic visual acuity. A total of 11 breachers and 4 engineers were followed for up to 17 months. No acute effects or longitudinal deteriorations were identified, but there were some interesting baseline group differences. Upbeat positional nystagmus was common, and correlated (p<0.005) with a history of mild traumatic brain injury (mTBI). Several instructors had abnormally short low-frequency phase leads on rotary chair testing. This study evaluated breaching instructors over a longer test period than any other study, and the results suggest that this population appears to be safe from a vestibular standpoint at the current exposure levels. Upbeat positional nystagmus correlated with a history of mTBI in this population, and this has not been described elsewhere. The data trends also suggest that this nystagmus could be an acute blast effect. However, the reasons for the abnormally short phase leads seen in rotary chair testing are unclear at this time. Further investigation seems warranted. PMID:25790248

  3. Bilateral optic neuritis in a boy - More than the eyes.

    PubMed

    Loh, M A; Alex Khoo, P C; Chong, M F

    2016-04-01

    Neuromyelitis optica (NMO) is a rare disorder in children with variable presentation. We report a 7-year-old boy who presented with bilateral retrobulbar optic neuritis and responded very well to treatment. He was also positive for aquaporin 4 (AQP4) antibodies, which is part of an emerging endophenotype within autoimmune neurological disorders in childhood. PMID:27326949

  4. Plasma exchange response in 34 patients with severe optic neuritis.

    PubMed

    Deschamps, Romain; Gueguen, Antoine; Parquet, Nathalie; Saheb, Samir; Driss, Francoise; Mesnil, Malcie; Vignal, Catherine; Aboab, Jennifer; Depaz, Raphael; Gout, Olivier

    2016-05-01

    Optic neuritis could lead to severe visual impairment despite corticosteroids. Our aim was to evaluate the rate of visual improvement in patients treated with plasma exchange (PLEX) for severe steroid unresponsive optic neuritis and to identify predictive factors of outcome. Thirty-four patients (41 optic nerves damaged) with remaining visual acuity of 0.1 or less despite steroid pulse therapy were treated with PLEX from September 2010 to May 2015. Demographic and clinical neuro-ophthalmic findings, and spectral domain-optical coherence tomography data before PLEX treatment were analyzed. The mean symptom duration before PLEX was 34.6 days (median 28 days; range 6-92 days). After PLEX, the median final visual acuity was 0.8 and in 56 % of cases, final acuity was 0.5 or better. Past history of ipsilateral optic neuritis was associated significantly with poor outcome defined as final acuity less than 0.5. No significant difference in the visual outcome after PLEX was found between multiple sclerosis and neuromyelitis optica. In conclusion, this observational study showed that PLEX as second-line therapy led to a functionally important visual recovery in more than half patients with severe optic neuritis. PMID:26964539

  5. Case-centered Analysis of Optic Neuritis After Vaccines.

    PubMed

    Baxter, Roger; Lewis, Edwin; Fireman, Bruce; DeStefano, Frank; Gee, Julianne; Klein, Nicola P

    2016-07-01

    We evaluated the risk of optic neuritis (ON) after vaccines, using a case-centered analysis, comparing the time since vaccination for the patients with ON with that for all similar vaccinees in a large integrated health plan population. We did not detect any association between ON and receipt of any type of vaccine. PMID:27069066

  6. Q fever as a possible cause of bilateral optic neuritis.

    PubMed Central

    Schuil, J; Richardus, J H; Baarsma, G S; Schaap, G J

    1985-01-01

    A 59-year-old farmer developed a bilateral optic neuritis in the course of an infection with Coxiella burnetii (Q fever), resulting in a lasting unilateral blindness. A complete medical (including neurological) evaluation gave no evidence of other possible causes. A possible source of infection was cattle. Images PMID:4016056

  7. The vestibular body: Vestibular contributions to bodily representations.

    PubMed

    Ferrè, Elisa Raffaella; Haggard, Patrick

    2016-01-01

    Vestibular signals are integrated with signals from other sensory modalities. This convergence could reflect an important mechanism for maintaining the perception of the body. Here we review the current literature in order to develop a framework for understanding how the vestibular system contributes to body representation. According to recent models, we distinguish between three processes for body representation, and we look at whether vestibular signals might influence each process. These are (i) somatosensation, the primary sensory processing of somatic stimuli, (ii) somatoperception, the processes of constructing percepts and experiences of somatic objects and events and (iii) somatorepresentation, the knowledge about the body as a physical object in the world. Vestibular signals appear to contribute to all three levels in this model of body processing. Thus, the traditional view of the vestibular system as a low-level, dedicated orienting module tends to underestimate the pervasive role of vestibular input in bodily self-awareness. PMID:27389959

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  10. Enlarged Vestibular Aqueducts and Childhood Hearing Loss

    MedlinePlus

    ... Health Info » Hearing, Ear Infections, and Deafness Enlarged Vestibular Aqueducts and Childhood Hearing Loss On this page: ... more information about enlarged vestibular aqueducts? What are vestibular aqueducts? The inner ear Credit: NIH Medical Arts ...

  11. SIRT1 Activation Confers Neuroprotection in Experimental Optic Neuritis

    PubMed Central

    Shindler, Kenneth S.; Ventura, Elvira; Rex, Tonia S.; Elliott, Peter; Rostami, Abdolmohamad

    2007-01-01

    Purpose Axonal damage and loss of neurons correlate with permanent vision loss and neurologic disability in patients with optic neuritis and multiple sclerosis (MS). Current therapies involve immunomodulation, with limited effects on neuronal damage. The authors examined potential neuroprotective effects in optic neuritis by SRT647 and SRT501, two structurally and mechanistically distinct activators of SIRT1, an enzyme involved in cellular stress resistance and survival. Methods Experimental autoimmune encephalomyelitis (EAE), an animal model of MS, was induced by immunization with proteolipid protein peptide in SJL/J mice. Optic neuritis developed in two thirds of eyes with significant retinal ganglion cell (RGC) loss detected 14 days after immunization. RGCs were labeled in a retrograde fashion with fluorogold by injection into superior colliculi. Optic neuritis was detected by inflammatory cell infiltration of the optic nerve. Results Intravitreal injection of SIRT1 activators 0, 3, 7, and 11 days after immunization significantly attenuated RGC loss in a dose-dependent manner. This neuroprotective effect was blocked by sirtinol, a SIRT1 inhibitor. Treatment with either SIRT1 activator did not prevent EAE or optic nerve inflammation. A single dose of SRT501 on day 11 was sufficient to limit RGC loss and to preserve axon function. Conclusions SIRT1 activators provide an important potential therapy to prevent the neuronal damage that leads to permanent neurologic disability in optic neuritis and MS patients. Intravitreal administration of SIRT1 activators does not suppress inflammation in this model, suggesting that their neuroprotective effects will be additive or synergistic with current immunomodulatory therapies. PMID:17652729

  12. Myelitis and optic neuritis induced by a long course of etanercept in a patient with rheumatoid arthritis

    PubMed Central

    Yokoyama, Waka; Takada, Kazuki; Miyasaka, Nobuyuki; Kohsaka, Hitoshi

    2014-01-01

    A 64-year-old woman presented with an acute onset of myelitis and optic neuritis after 47 months of etanercept use for rheumatoid arthritis. Etanercept was discontinued and pulse methylprednisolone therapy (1000 mg/day for 3 days) was started, followed by a quick and complete resolution. Demyelination associated with antitumor necrosis factor agents, reported to develop mostly from 1 week to 12 months after the initiation of the agents, could develop after a few years and thus warrants vigilant monitoring. PMID:25085953

  13. A real-time research platform to study vestibular implants with gyroscopic inputs in vestibular deficient subjects.

    PubMed

    Nguyen, T A Khoa; Ranieri, Maurizio; DiGiovanna, Jack; Peter, Otto; Genovese, Vincenzo; Perez Fornos, Angelica; Micera, Silvestro

    2014-08-01

    Researchers have succeeded in partly restoring damaged vestibular functionality in several animal models. Recently, acute interventions have also been demonstrated in human patients. Our previous work on a vestibular implant for humans used predefined stimulation patterns; here we present a research tool that facilitates motion-modulated stimulation. This requires a system that can process gyroscope measurements and send stimulation parameters to a hybrid vestibular-cochlear implant in real-time. To match natural vestibular latencies, the time from sensor input to stimulation output should not exceed 6.5 ms. We describe a system based on National Instrument's CompactRIO platform that can meet this requirement and also offers floating point precision for advanced transfer functions. It is designed for acute clinical interventions, and is sufficiently powerful and flexible to serve as a development platform for evaluating prosthetic control strategies. Amplitude and pulse frequency modulation to predetermined functions or sensor inputs have been validated. The system has been connected to human patients, who each have received a modified MED-EL cochlear implant for vestibular stimulation, and patient tests are ongoing. PMID:25073124

  14. BDNF signaling in the rat cerebello-vestibular pathway during vestibular compensation: BDNF signaling in vestibular compensation.

    PubMed

    Zhou, Liuqing; Zhou, Wen; Zhang, Sulin; Liu, Bo; Liang, Pei; Zhou, Yan; Zhou, Tao; Zhang, Kun; Leng, Yangming; Kong, Weijia

    2015-09-01

    Vestibular compensation, which is the behavioral recovery from lesions to the peripheral vestibular system, is attributed to plasticity of the central vestibular system. It has been reported that brain-derived neurotrophic factor (BDNF) is expressed and released in an activity-dependent manner. Upon binding to the tyrosine receptor kinase B (TrkB), BDNF can acutely modulate synaptic transmission and plasticity in the central nervous system. To assess the possible contribution of BDNF to this recovery process, we studied the expression of BDNF, TrkB.FL, TrkB.T1 and KCC2 (K(+) -Cl(-) cotransporter isoform 2) in the bilateral medial vestibular nucleus (MVN) and the flocculus of rats at 4 h, 8 h, 1, 3 and 7 days following unilateral labyrinthectomy (UL) using immunohistochemistry, quantitative real-time PCR and western blotting. Our results have shown that, compared with the sham controls and the contra-lesional side, (a) the expression of BDNF and TrkB.FL increased at 4 h in the ipsi-lesional flocculus after UL; (b) the expression of TrkB.T1 decreased at 4 h and KCC2 decreased at 8 h and 1 day in the ipsi-lesional flocculus after UL; and (c) BDNF and TrkB.FL expression was enhanced and KCC2 expression was reduced in the ipsi-lesional MVN at 8 h after UL. Our data supported the hypothesis that BDNF upregulation may reduce the inhibitory effects of the flocculus and commissural inhibition system by regulating inhibitory GABAergic synaptic transmission in floccular Purkinje cells and Purkinje cell terminals in the MVN. Additionally, KCC2 may be a switch in this process. PMID:26111610

  15. Vestibular Function Measurement Devices

    PubMed Central

    Miles, Richard D.; Zapala, David A.

    2015-01-01

    Vestibular function laboratories utilize a multitude of diagnostic instruments to evaluate a dizzy patient. Caloric irrigators, oculomotor stimuli, and rotational chairs produce a stimulus whose accuracy is required for the patient response to be accurate. Careful attention to everything from cleanliness of equipment to threshold adjustments determine on a daily basis if patient data are going to be correct and useful. Instrumentation specifications that change with time such as speed and temperature must periodically be checked using calibrated instruments. PMID:27516710

  16. Role of the Insula and Vestibular System in Patients with Chronic Subjective Dizziness: An fMRI Study Using Sound-Evoked Vestibular Stimulation

    PubMed Central

    Indovina, Iole; Riccelli, Roberta; Chiarella, Giuseppe; Petrolo, Claudio; Augimeri, Antonio; Giofrè, Laura; Lacquaniti, Francesco; Staab, Jeffrey P.; Passamonti, Luca

    2015-01-01

    Chronic subjective dizziness (CSD) is a common vestibular disorder characterized by persistent non-vertiginous dizziness, unsteadiness, and heightened sensitivity to motion stimuli that may last for months to years after events that cause acute vestibular symptoms or disrupt balance. CSD is not associated with abnormalities of basic vestibular or oculomotor reflexes. Rather, it is thought to arise from persistent use of high-threat postural control strategies and greater reliance on visual cues for spatial orientation (i.e., visual dependence), long after triggering events resolve. Anxiety-related personality traits confer vulnerability to CSD. Anomalous interactions between the central vestibular system and neural structures related to anxiety may sustain it. Vestibular- and anxiety-related processes overlap in the brain, particularly in the insula and hippocampus. Alterations in activity and connectivity in these brain regions in response to vestibular stimuli may be the neural basis of CSD. We examined this hypothesis by comparing brain activity from 18 patients with CSD and 18 healthy controls measured by functional magnetic resonance imaging during loud short tone bursts, which are auditory stimuli that evoke robust vestibular responses. Relative to controls, patients with CSD showed reduced activations to sound-evoked vestibular stimulation in the parieto-insular vestibular cortex (PIVC) including the posterior insula, and in the anterior insula, inferior frontal gyrus, hippocampus, and anterior cingulate cortex. Patients with CSD also showed altered connectivity between the anterior insula and PIVC, anterior insula and middle occipital cortex, hippocampus and PIVC, and anterior cingulate cortex and PIVC. We conclude that reduced activation in PIVC, hippocampus, anterior insula, inferior frontal gyrus, and anterior cingulate cortex, as well as connectivity changes among these regions, may be linked to long-term vestibular symptoms in patients with CSD

  17. Role of Vegetarianism, Smoking, and Hydroxocobalamin in Optic Neuritis

    PubMed Central

    Wadia, N. H.; Desai, M. M.; Quadros, E. V.; Dastur, D. K.

    1972-01-01

    Only 20 patients with optic neuritis of unknown aetiology could be collected in Bombay over a period of two and a half years. Only six of them were smokers and only three (one a non-smoker) had bilateral centrocaecal scotomata similar to those found in tobacco amblyopia. In 11 untreated patients the serum vitamin B12 and plasma thiocyanate levels were estimated and found to show no significant differences from those in normal control subjects. Treatment with hydroxocobalamin in the majority of cases and with cyanocobalamin, corticotrophin, or prednisolone in the rest showed equally good results; spontaneous improvement was seen in one case. No significant role could be assigned to smoking (cyanide) or to vegetarianism in the production of optic neuritis in these patients; nor was there any evidence of depletion of total (cyanide-extracted) B12 or of an increase in the proportion of non-cyanide-extracted B12 in the serum. PMID:4339973

  18. Vestibular pathways involved in cognition

    PubMed Central

    Hitier, Martin; Besnard, Stephane; Smith, Paul F.

    2014-01-01

    Recent discoveries have emphasized the role of the vestibular system in cognitive processes such as memory, spatial navigation and bodily self-consciousness. A precise understanding of the vestibular pathways involved is essential to understand the consequences of vestibular diseases for cognition, as well as develop therapeutic strategies to facilitate recovery. The knowledge of the “vestibular cortical projection areas”, defined as the cortical areas activated by vestibular stimulation, has dramatically increased over the last several years from both anatomical and functional points of view. Four major pathways have been hypothesized to transmit vestibular information to the vestibular cortex: (1) the vestibulo-thalamo-cortical pathway, which probably transmits spatial information about the environment via the parietal, entorhinal and perirhinal cortices to the hippocampus and is associated with spatial representation and self-versus object motion distinctions; (2) the pathway from the dorsal tegmental nucleus via the lateral mammillary nucleus, the anterodorsal nucleus of the thalamus to the entorhinal cortex, which transmits information for estimations of head direction; (3) the pathway via the nucleus reticularis pontis oralis, the supramammillary nucleus and the medial septum to the hippocampus, which transmits information supporting hippocampal theta rhythm and memory; and (4) a possible pathway via the cerebellum, and the ventral lateral nucleus of the thalamus (perhaps to the parietal cortex), which transmits information for spatial learning. Finally a new pathway is hypothesized via the basal ganglia, potentially involved in spatial learning and spatial memory. From these pathways, progressively emerges the anatomical network of vestibular cognition. PMID:25100954

  19. Childhood Vestibular Disorders: A Tutorial

    ERIC Educational Resources Information Center

    Mehta, Zarin; Stakiw, Daria B.

    2004-01-01

    There is a growing body of evidence that childhood disorders affecting the vestibular system, although rare, do exist. Describing symptoms associated with the vestibular mechanism for children may be difficult, resulting in misdiagnosing or under-diagnosing these conditions. The pathophysiology, symptoms, and management options of the more common…

  20. Subjective postural vertical in peripheral and central vestibular disorders.

    PubMed

    Bisdorff, A R; Anastasopoulos, D; Bronstein, A M; Gresty, M A

    1995-01-01

    The perception of subjective postural vertical was assessed in normals and patients with peripheral and central vestibular disorders and spasmodic torticollis. The subjects were seated in a motorized gimbal with the head and torso restrained and their eyes closed. The gimbal executed 7-10 cycles of tilt around the vertical at 1.5 degrees/s in either pitch or roll. Subjects indicated when they began to feel upright and again when they began to feel tilted by an analogous 3-position joystick. Normal subjects felt upright within a sector of 5-6 degrees around vertical in pitch and roll. Five patients with absent vestibular function, 25 torticollis patients and 3 patients with acute unilateral peripheral vestibular lesions showed a significant increase of the sector in pitch and roll, but only the latter had a mild directional bias. Two patients with long standing complete unilateral vestibular deficit and 8 patients with up or downbeat nystagmus in the vicinity of upright had abnormally large sectors within which they felt to be upright. The results suggest that vestibular function is important for the accurate perception of the postural vertical and that a directional asymmetry in vestibulo-ocular function or a head tilt does not necessarily correlate with a directional bias of subjective verticality. PMID:8749084

  1. Mucocele After Orbital Fracture Repair Masquerading as Optic Neuritis.

    PubMed

    Park, Jongyeop; Kim, Jinhyun; Choi, Jinsu; Kim, Hochang

    2016-06-01

    The authors report a patient of mucocele formation after orbital wall fracture repair masquerading as optic neuritis.A 38-year-old man with a history of medial orbital wall fracture repair with an alloplastic implant 10 years previously, presented with left visual disturbance and mild ocular pain with movement of the left eye of 3-day duration, and a relative afferent papillary defect in his left eye. He reported having cold symptoms 2 weeks before presentation. His symptoms were typical of retrobulbar optic neuritis. Under suspicion of optic neuritis, computed tomography and magnetic resonance imaging were performed and revealed a large cyst in the sphenoid sinus and ethmoid sinus, just behind the alloplastic implant, that was compressing the medial rectus muscle and optic nerve of the left eye. The patient underwent endoscopic marsupialization of the cyst. Subsequent histologic examinations revealed a cyst lined with ciliated pseudostratified columnar epithelium. The patient had an uncomplicated postoperative course and the visual disturbance resolved. For patients who present solely with optic neuropathy after orbital fracture repair, it is important to be vigilant of potentially rare cause, mucocele formation. PMID:27171955

  2. Vestibular disease in dogs and cats.

    PubMed

    Rossmeisl, John H

    2010-01-01

    The vestibular system is the major sensory (special proprioceptive) system that, along with the general proprioceptive and visual systems, maintains balance. Clinical signs of vestibular disease include asymmetric ataxia, head tilt, and pathologic nystagmus. Neuroanatomic localization of observed vestibular signs to either the peripheral or central components of the vestibular system is paramount to the management of the patient with vestibular dysfunction, as the etiology, diagnostic approaches, and prognoses are dependent on the neuroanatomic diagnosis. This article reviews functional vestibular neuroanatomy as well as the diagnosis and treatment of common causes of small animal vestibular disease. PMID:19942058

  3. Vestibular Rehabilitation Outcomes in the Elderly with Chronic Vestibular Dysfunction

    PubMed Central

    Bayat, Arash; Pourbakht, Akram; Saki, Nader; Zainun, Zuraida; Nikakhlagh, Soheila; Mirmomeni, Golshan

    2012-01-01

    Background Chronic vestibular dysfunction is a frustrating problem in the elderly and can have a tremendous impact on their life, but only a few studies are available. Vestibular rehabilitation therapy (VRT) is an important therapeutic option for the neuro-otologist in treating patients with significant balance deficits. Objectives The purpose of this study was to assess the effect of vestibular rehabilitation on dizziness in elderly patients with chronic vestibular dysfunction. Materials and Methods A total of 33 patients older than 60 years with chronic vestibular dysfunction were studied. Clinical and objective vestibular tests including videonystagmography (VNG) and dizziness handicap inventory (DHI) were carried out at their first visit, 2 weeks, and 8 weeks post-VRT. The VRT exercises were performed according to Cawthorne and Cooksey protocols. Results Oculomotor assessments were within normal limits in all patients. Nineteen patients (57.57%) showed abnormal canal paralysis on caloric testing which at follow-up sessions; CP values were decreased remarkably after VRT exercises. We found a significant improvement between pre-VRT and post-VRT total DHI scores (P < 0.001). This improvement was most prominent in functional subscore. Conclusions Our study demonstrated that VRT is an effective therapeutic method for elderly patients with chronic vestibular dysfunction. PMID:23396380

  4. Neurological complications of acute multifocal placoid pigment epitheliopathy.

    PubMed

    Brownlee, W J; Anderson, N E; Sims, J; Pereira, J A

    2016-09-01

    Acute multifocal placoid pigment epitheliopathy (AMPPE) is an autoimmune chorioretinal disease that can be complicated by neurological involvement. There is limited information on this potentially treatable condition in the neurological literature. The objective of this patient series is to describe the neurological complications of AMPPE. We retrospectively identified patients with neurological complications of AMPPE seen at Auckland Hospital between 2008 and 2013 and summarised cases in the literature between 1976 and 2013. We identified five patients with neurological complications of AMPPE at Auckland Hospital and 47 reported patients. These patients demonstrated a spectrum of neurological involvement including isolated headache, stroke or transient ischaemic attack, seizures, venous sinus thrombosis, optic neuritis, sensorineural hearing loss and peripheral vestibular disorder. We propose criteria to define AMPPE with neurological complications. A cerebrospinal fluid (CSF) lymphocytosis in a patient with isolated headache may predict the development of cerebrovascular complications of AMPPE. Patients with cerebrovascular complications of AMPPE have a poor prognosis with high rates of death and neurological disability among survivors. Predictors of poor outcome in those who develop neurological complications of AMPPE are a relapsing course, generalised seizures and multifocal infarction on MRI. All patients with neurological complications of AMPPE, including headache alone, should be investigated with an MRI brain and CSF examination. Patients with focal neurological symptoms should receive intravenous (IV) methylprednisolone followed by a tapering course of oral steroids for at least 3months. Patients with AMPPE and an isolated headache with a CSF pleocytosis should be treated with oral steroids. PMID:27183958

  5. Visuo-Vestibular Interactions

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Session TA3 includes short reports covering: (1) Vestibulo-Oculomotor Interaction in Long-Term Microgravity; (2) Effects of Weightlessness on the Spatial Orientation of Visually Induced Eye Movements; (3) Adaptive Modification of the Three-Dimensional Vestibulo-Ocular Reflex during Prolonged Microgravity; (4) The Dynamic Change of Brain Potential Related to Selective Attention to Visual Signals from Left and Right Visual Fields; (5) Locomotor Errors Caused by Vestibular Suppression; and (6) A Novel, Image-Based Technique for Three-Dimensional Eye Measurement.

  6. Unilateral syphilitic perioptic neuritis in a patient coinfected with human immunodeficiency virus type 1

    PubMed Central

    Basta, Medhat S T; Sankar, K Nathan; Dayan, Margaret

    2007-01-01

    Perioptic neuritis caused by secondary syphilis is a rare ophthalmic manifestation in the HIV‐infected host. Early diagnosis and treatment of this condition is required to prevent further visual damage. We report a case of unilateral syphilitic perioptic neuritis in a patient coinfected with HIV‐1. PMID:17569719

  7. The First Case of Vestibulocochlear Neuritis in a Patient with Acquired Immunodeficiency Syndrome in Korea

    PubMed Central

    Park, Hyun Joo; Cho, Chin Saeng; Kim, Nak Min; Yun, Su A

    2016-01-01

    The incidence of human immunodeficiency virus (HIV) infections continue to increase throughout the world. Although neurologic complications are frequent in individuals with HIV infection or acquired immunodeficiency syndrome (AIDS), vestibulocochlear neuritis is still a relatively rare manifestation. We report the first case of vestibulocochlear neuritis occurring in an AIDS patient in Korea. PMID:27433384

  8. 'The worm that got away': parainfectious atypical optic neuritis associated with schistosomiasis infection.

    PubMed

    Osman, Chinar; Hannigan, Sally; Ditchfield, Adam; Harden, Stephen; Marshall, Ben; Pinto, Ashwin Arnold

    2016-06-01

    Although optic neuritis is commonly associated with multiple sclerosis, patients with atypical optic neuritis require further investigations to exclude other associated conditions. We report a woman presenting with cough, fatigue, atypical optic neuritis with chiasmitis. She responded partially to corticosteroids and we subsequently found she had a ground-glass lung nodule. Follow-up CT scan of thorax at 12 months showed new parenchymal lung lesions that suggested schistosomiasis. Further questioning by a respiratory physician identified, in retrospect, a previous exposure history; serological testing confirmed schistosoma infection. She was treated with praziquantel and slowly improved clinically, with radiological improvement in the optic chiasm, regression of the parenchymal lung lesions but with the ground glass nodule unchanged. We diagnosed parainfectious optic neuritis associated with schistosomiasis, based upon exposure history, serological confirmation and radiological features, together with the response to treatment, and having excluded other causes of an atypical optic neuritis. PMID:26888797

  9. Vestibular influence on tongue activity.

    PubMed

    Elmund, J; Bowman, J P; Morgan, R J

    1983-07-01

    The vestibular system was electrically stimulated in cats anesthetized with ketamine. Peripheral stimulation by an electrode positioned in the vestibule evoked torsional contralateral eye deviations and an electromyogram (EMG) response in a contralateral dorsal neck extensor. Consistently associated with this well documented vestibular pattern was an EMG response in tongue protrusive muscles, at a latency of 13 +/- 5 (means +/- SD) ms. Stimulation in a specific part of the rostroventral lateral vestibular nucleus elicited the same combination of responses: torsional contralateral eye deviations, dorsal neck EMG, and tongue EMG at a latency of 14 +/- 3 ms. Possible tongue activation by current spread to peripheral and central neural structures was examined in detail. Cerebellar, V, VII, cochlear, IX, X, and XII nerve influences were considered. On the basis of combined evidence, it was concluded that the vestibular system does influence tongue activity. PMID:6602714

  10. Vestibular reflexes of otolith origin

    NASA Technical Reports Server (NTRS)

    Wilson, Victor J.

    1988-01-01

    The vestibular system and its role in the maintenance of posture and in motion sickness is investigated using cats as experimental subjects. The assumption is that better understanding of the physiology of vestibular pathways is not only of intrinsic value, but will help to explain and eventually alleviate the disturbances caused by vestibular malfunction, or by exposure to an unusual environment such as space. The first project deals with the influence on the spinal cord of stimulation of the vestibular labyrinth, particularly the otoliths. A second was concerned with the properties and neural basis of the tonic neck reflex. These two projects are related, because vestibulospinal and tonic neck reflexes interact in the maintenance of normal posture. The third project began with an interest in mechanisms of motion sickness, and eventually shifted to a study of central control of respiratory muscles involved in vomiting.

  11. Myelin-specific Th17 cells induce severe relapsing optic neuritis with irreversible loss of retinal ganglion cells in C57BL/6 mice

    PubMed Central

    Larabee, Chelsea M.; Hu, Yang; Desai, Shruti; Georgescu, Constantin; Wren, Jonathan D.; Axtell, Robert C.

    2016-01-01

    Purpose Optic neuritis affects most patients with multiple sclerosis (MS), and current treatments are unreliable. The purpose of this study was to characterize the contribution of Th1 and Th17 cells to the development of optic neuritis. Methods Mice were passively transferred myelin-specific Th1 or Th17 cells to induce experimental autoimmune encephalomyelitis (EAE), a model of neuroautoimmunity. Visual acuity was assessed daily with optokinetic tracking, and 1, 2, and 3 weeks post-induction, optic nerves and retinas were harvested for immunohistochemical analyses. Results Passive transfer experimental autoimmune encephalomyelitis elicits acute episodes of asymmetric visual deficits and is exacerbated in Th17-EAE relative to Th1-EAE. The Th17-EAE optic nerves contained more inflammatory infiltrates and an increased neutrophil to macrophage ratio. Significant geographic degeneration of the retinal ganglion cells accompanied Th17-EAE but not Th1. Conclusions Th17-induced transfer EAE recapitulates pathologies observed in MS-associated optic neuritis, namely, monocular episodes of vision loss, optic nerve inflammation, and geographic retinal ganglion cell (RGC) degeneration. PMID:27122964

  12. Bilateral optic neuritis in a patient with Behçet's disease who respond to therapeutic plasma exchange.

    PubMed

    Erdoğan, Seyda; Sorgun, Mine Hayriye; Yalçındağ, Nilüfer; Atilla, Huban; Yücesan, Canan

    2015-01-01

    Bilateral optic neuritis has been reported very rarely as a manifestation of neuro-Behçet's disease. We present a 50 year old woman who had 20-year history of Behçet's disease presented with acutely blurred vision associated with orbital pain in both eyes. Visual acuity was 0.4 in the right eye and light perception in the left eye; afferent pupillary defect was detected in the left eye. Bilateral swelling of the optic disk was found. The cerebrospinal fluid sample tests were within normal limits. Brain magnetic resonance imaging, magnetic resonance venography and fundus fluorescein angiography were normal. She was diagnosed with bilateral optic neuritis and treated with intravenous methyl prednisolone for 10 days. As there was no response to the treatment, therapeutic plasma exchange was started and the patient's visual acuities improved moderately. We suggest that when high dose steroid is failed to treat ON in BD, treatment with TPE may be considered. PMID:26586983

  13. Vestibular reactions of astronauts during flight in Voskhod spacecraft

    NASA Technical Reports Server (NTRS)

    Yuganov, Y. M.; Gorshkov, A. I.; Kasyan, I. I.; Bryanov, I. I.; Kolosov, I. A.; Kopanev, V. I.; Solodovnik, F. A.; Lebedev, V. I.; Popov, N. I.

    1975-01-01

    It is shown that differing human vestibular resistances to weightlessness stress are connected with the nonuniform initial sensitivity of the vestibular apparatus, as well as with different lengths of vestibular training. However, intensive vestibular training of persons with a moderate degree of sensitivity of the vestibular analyzer does not ensure vestibular stability under weightlessness conditions.

  14. Morphological studies of the vestibular nerve

    NASA Technical Reports Server (NTRS)

    Bergstroem, B.

    1973-01-01

    The anatomy of the intratemporal part of the vestibular nerve in man, and the possible age related degenerative changes in the nerve were studied. The form and structure of the vestibular ganglion was studied with the light microscope. A numerical analysis of the vestibular nerve, and caliber spectra of the myelinated fibers in the vestibular nerve branches were studied in individuals of varying ages. It was found that the peripheral endings of the vestibular nerve form a complicated pattern inside the vestibular sensory epithelia. A detailed description of the sensory cells and their surface organelles is included.

  15. Perspectives on Aging Vestibular Function

    PubMed Central

    Anson, Eric; Jeka, John

    2016-01-01

    Much is known about age-related anatomical changes in the vestibular system. Knowledge regarding how vestibular anatomical changes impact behavior for older adults continues to grow, in line with advancements in diagnostic testing. However, despite advancements in clinical diagnostics, much remains unknown about the functional impact that an aging vestibular system has on daily life activities such as standing and walking. Modern diagnostic tests are very good at characterizing neural activity of the isolated vestibular system, but the tests themselves are artificial and do not reflect the multisensory aspects of natural human behavior. Also, the majority of clinical diagnostic tests are passively applied because active behavior can enhance performance. In this perspective paper, we review anatomical and behavioral changes associated with an aging vestibular system and highlight several areas where a more functionally relevant perspective can be taken. For postural control, a multisensory perturbation approach could be used to bring balance rehabilitation into the arena of precision medicine. For walking and complex gaze stability, this may result in less physiologically specific impairments, but the trade-off would be a greater understanding of how the aging vestibular system truly impacts the daily life of older adults. PMID:26779116

  16. Perspectives on Aging Vestibular Function.

    PubMed

    Anson, Eric; Jeka, John

    2015-01-01

    Much is known about age-related anatomical changes in the vestibular system. Knowledge regarding how vestibular anatomical changes impact behavior for older adults continues to grow, in line with advancements in diagnostic testing. However, despite advancements in clinical diagnostics, much remains unknown about the functional impact that an aging vestibular system has on daily life activities such as standing and walking. Modern diagnostic tests are very good at characterizing neural activity of the isolated vestibular system, but the tests themselves are artificial and do not reflect the multisensory aspects of natural human behavior. Also, the majority of clinical diagnostic tests are passively applied because active behavior can enhance performance. In this perspective paper, we review anatomical and behavioral changes associated with an aging vestibular system and highlight several areas where a more functionally relevant perspective can be taken. For postural control, a multisensory perturbation approach could be used to bring balance rehabilitation into the arena of precision medicine. For walking and complex gaze stability, this may result in less physiologically specific impairments, but the trade-off would be a greater understanding of how the aging vestibular system truly impacts the daily life of older adults. PMID:26779116

  17. Neuropharmacology of Vestibular System Disorders

    PubMed Central

    Soto, Enrique; Vega, Rosario

    2010-01-01

    This work reviews the neuropharmacology of the vestibular system, with an emphasis on the mechanism of action of drugs used in the treatment of vestibular disorders. Otolaryngologists are confronted with a rapidly changing field in which advances in the knowledge of ionic channel function and synaptic transmission mechanisms have led to the development of new scientific models for the understanding of vestibular dysfunction and its management. In particular, there have been recent advances in our knowledge of the fundamental mechanisms of vestibular system function and drug mechanisms of action. In this work, drugs acting on vestibular system have been grouped into two main categories according to their primary mechanisms of action: those with effects on neurotransmitters and neuromodulator receptors and those that act on voltage-gated ion channels. Particular attention is given in this review to drugs that may provide additional insight into the pathophysiology of vestibular diseases. A critical review of the pharmacology and highlights of the major advances are discussed in each case. PMID:20808544

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

    PubMed

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

    2014-01-01

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

  19. Ethical, anatomical and physiological issues in developing vestibular implants for human use.

    PubMed

    Guyot, Jean-Philippe; Gay, Annietta; Kos, Maria Izabel; Pelizzone, Marco

    2012-01-01

    Effort towards the development of a vestibular implant for human use are being made. This paper will summarize the first important steps conducted in Geneva towards this ambitious goal. Basically, we have faced three major issues. First, an ethical issue. While it was clear that such development would require the collaboration of human volunteers, it was also clear that stimulation of the vestibular system may produce periods of significant incomfort. We know today how to minimize (and potentially eliminate) this type of incomfort. The second issue was anatomical. The anatomical topology of the vestibular system is complex, and of potentially dangerous access (i.e. facial nerve damage). We choose not to place the electrodes inside the ampullae but close the vestibular nerve branches, to avoid any opening of the inner ear and limit the risk of hearing loss. Work on cadaver heads, confirmed by acute stimulations trials on patients undergoing ear surgery under local anesthesia, demonstrated that it is possible to stimulate selectively both the posterior and lateral ampullary nerves, and elicit the expected vertical and horizontal nystagmic responses. The third issue was physiological. One of the goal of a vestibular implant will be to produce smooth eye movements to stabilize gaze direction when the head is moving. Indeed, after restoring a baseline or "rest" activity in the vestibular pathways with steady-state electrical stimulation, we demonstrated that modulation of this stimulation is producing smooth eye movements. In conclusion, humans can adapt to electrical stimulation of the vestibular system without too much discomfort. Surgical access to the posterior and lateral ampullary nerves have been developed and, electrical stimulation of the vestibular system can be used to artificially elicit smooth eye movements of different speeds and directions, once the system is in adapted state. Therefore, the major prerequisites to develop a prototype vestibular implant

  20. Habituation of vestibular responses: An overview

    NASA Technical Reports Server (NTRS)

    Collins, W. E.

    1973-01-01

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

  1. Compensation Following Bilateral Vestibular Damage

    PubMed Central

    McCall, Andrew A.; Yates, Bill J.

    2011-01-01

    Bilateral loss of vestibular inputs affects far fewer patients than unilateral inner ear damage, and thus has been understudied. In both animal subjects and human patients, bilateral vestibular hypofunction (BVH) produces a variety of clinical problems, including impaired balance control, inability to maintain stable blood pressure during postural changes, difficulty in visual targeting of images, and disturbances in spatial memory and navigational performance. Experiments in animals have shown that non-labyrinthine inputs to the vestibular nuclei are rapidly amplified following the onset of BVH, which may explain the recovery of postural stability and orthostatic tolerance that occurs within 10 days. However, the loss of the vestibulo-ocular reflex and degraded spatial cognition appear to be permanent in animals with BVH. Current concepts of the compensatory mechanisms in humans with BVH are largely inferential, as there is a lack of data from patients early in the disease process. Translation of animal studies of compensation for BVH into therapeutic strategies and subsequent application in the clinic is the most likely route to improve treatment. In addition to physical therapy, two types of prosthetic devices have been proposed to treat individuals with bilateral loss of vestibular inputs: those that provide tactile stimulation to indicate body position in space, and those that deliver electrical stimuli to branches of the vestibular nerve in accordance with head movements. The relative efficacy of these two treatment paradigms, and whether they can be combined to facilitate recovery, is yet to be ascertained. PMID:22207864

  2. Vestibular schwannoma surgery and headache.

    PubMed

    Levo, H; Blomstedt, G; Pyykkö, I

    2000-01-01

    The aim of the study was to evaluate aetiological factors for postoperative headache after vestibular schwannoma (VS) surgery with respect to asymmetric activation of vestibular reflexes. After surgery, 27 VS patients with persistent postoperative headache, 16 VS patients without headache and 9 healthy controls were examined. The vestibular, cervicocollic and cervicospinal reflexes were evaluated to study whether asymmetric activation of vestibular reflexes could cause headache. The effect of neck muscle and occipital nerve anaesthesia and the effect of sumatriptan on headache were also evaluated. The vestibular function of VS patients with headache did not differ from that of VS patients without headache, but was abnormal when compared to that of normal controls. The cervicospinal and cervicocollic reflexes did not differ in the patient groups. Injection of lidocaine around the operation scar gave pain relief to two patients, and one of them had occipital nerve entrapment. Infiltration of lidocaine deep in the neck muscles in the vicinity of the C2 root did not alleviate headache, but caused vertigo. Nine patients with musculogenic headache got pain relief from supportive neck collars, and two patients with cervicobrachial syndrome got pain relief from manual neck traction. The study shows that asymmetric activation of cervicocollic reflexes does not seem to be the reason for headache. Headache seems to be linked to neuropathic pain, allegedly caused by trigeminal irritation of the inner ear and the posterior fossa, which has recently been linked to vascular pain. PMID:10908966

  3. Vestibular modulation of spatial perception.

    PubMed

    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. Brief left-anodal and right-cathodal GVS or right-anodal and left-cathodal GVS were delivered. A sham stimulation condition was also included. Participants bisected lines of different lengths at six distances from the body using a laser pointer. Consistent with previous results, our data showed an overall shift in the bisection bias from left to right as viewing distance increased. This pattern suggests leftward bias in near space, and rightward bias in far space. GVS induced strong polarity dependent effects in spatial perception, broadly consistent with those previously reported in patients: left-anodal and right-cathodal GVS induced a leftward bisection bias, while right-anodal and left-cathodal GVS reversed this effect, and produced bisection bias toward the right side of the space. Interestingly, the effects of GVS were comparable in near and far space. We speculate that vestibular-induced biases in space perception may optimize gathering of information from different parts of the environment. PMID:24133440

  4. Parallel Changes in Structural and Functional Measures of Optic Nerve Myelination after Optic Neuritis

    PubMed Central

    van der Walt, Anneke; Kolbe, Scott; Mitchell, Peter; Wang, Yejun; Butzkueven, Helmut; Egan, Gary; Yiannikas, Con; Graham, Stuart; Kilpatrick, Trevor; Klistorner, Alexander

    2015-01-01

    Introduction Visual evoked potential (VEP) latency prolongation and optic nerve lesion length after acute optic neuritis (ON) corresponds to the degree of demyelination, while subsequent recovery of latency may represent optic nerve remyelination. We aimed to investigate the relationship between multifocal VEP (mfVEP) latency and optic nerve lesion length after acute ON. Methods Thirty acute ON patients were studied at 1,3,6 and 12 months using mfVEP and at 1 and 12 months with optic nerve MRI. LogMAR and low contrast visual acuity were documented. By one month, the mfVEP amplitude had recovered sufficiently for latency to be measured in 23 (76.7%) patients with seven patients having no recordable mfVEP in more than 66% of segments in at least one test. Only data from these 23 patients was analysed further. Results Both latency and lesion length showed significant recovery during the follow-up period. Lesion length and mfVEP latency were highly correlated at 1 (r = 0.94, p = <0.0001) and 12 months (r = 0.75, p < 0.001). Both measures demonstrated a similar trend of recovery. Speed of latency recovery was faster in the early follow-up period while lesion length shortening remained relatively constant. At 1 month, latency delay was worse by 1.76ms for additional 1mm of lesion length while at 12 months, 1mm of lesion length accounted for 1.94ms of latency delay. Conclusion A strong association between two putative measures of demyelination in early and chronic ON was found. Parallel recovery of both measures could reflect optic nerve remyelination. PMID:26020925

  5. Evidence for a Role of Orexin/Hypocretin System in Vestibular Lesion-Induced Locomotor Abnormalities in Rats

    PubMed Central

    Pan, Leilei; Qi, Ruirui; Wang, Junqin; Zhou, Wei; Liu, Jiluo; Cai, Yiling

    2016-01-01

    Vestibular damage can induce locomotor abnormalities in both animals and humans. Rodents with bilateral vestibular loss showed vestibular deficits syndrome such as circling, opisthotonus as well as locomotor and exploratory hyperactivity. Previous studies have investigated the changes in the dopamine system after vestibular loss, but the results are inconsistent and inconclusive. Numerous evidences indicate that the orexin system is implicated in central motor control. We hypothesized that orexin may be potentially involved in vestibular loss-induced motor disorders. In this study, we examined the effects of arsanilate- or 3,3′-iminodipropionitrile (IDPN)-induced vestibular lesion (AVL or IVL) on the orexin-A (OXA) labeling in rat hypothalamus using immunohistochemistry. The vestibular lesion-induced locomotor abnormalities were recorded and verified using a histamine H4 receptor antagonist JNJ7777120 (20 mg/kg, i.p.). The effects of the orexin receptor type 1 antagonist SB334867 (16 μg, i.c.v.) on these behavior responses were also investigated. At 72 h post-AVL and IVL, animals exhibited vestibular deficit syndrome and locomotor hyperactivity in the home cages. These responses were significantly alleviated by JNJ7777120 which also eliminated AVL-induced increases in exploratory behavior in an open field. The numbers of OXA-labeled neurons in the hypothalamus were significantly increased in the AVL animals at 72 h post-AVL and in the IVL animals at 24, 48, and 72 h post-IVL. SB334867 significantly attenuated the vestibular deficit syndrome and locomotor hyperactivity at 72 h post-AVL and IVL. It also decreased exploratory behavior in the AVL animals. These results suggested that the alteration of OXA expression might contribute to locomotor abnormalities after acute vestibular lesion. The orexin receptors might be the potential therapeutic targets for vestibular disorders. PMID:27507932

  6. Evidence for a Role of Orexin/Hypocretin System in Vestibular Lesion-Induced Locomotor Abnormalities in Rats.

    PubMed

    Pan, Leilei; Qi, Ruirui; Wang, Junqin; Zhou, Wei; Liu, Jiluo; Cai, Yiling

    2016-01-01

    Vestibular damage can induce locomotor abnormalities in both animals and humans. Rodents with bilateral vestibular loss showed vestibular deficits syndrome such as circling, opisthotonus as well as locomotor and exploratory hyperactivity. Previous studies have investigated the changes in the dopamine system after vestibular loss, but the results are inconsistent and inconclusive. Numerous evidences indicate that the orexin system is implicated in central motor control. We hypothesized that orexin may be potentially involved in vestibular loss-induced motor disorders. In this study, we examined the effects of arsanilate- or 3,3'-iminodipropionitrile (IDPN)-induced vestibular lesion (AVL or IVL) on the orexin-A (OXA) labeling in rat hypothalamus using immunohistochemistry. The vestibular lesion-induced locomotor abnormalities were recorded and verified using a histamine H4 receptor antagonist JNJ7777120 (20 mg/kg, i.p.). The effects of the orexin receptor type 1 antagonist SB334867 (16 μg, i.c.v.) on these behavior responses were also investigated. At 72 h post-AVL and IVL, animals exhibited vestibular deficit syndrome and locomotor hyperactivity in the home cages. These responses were significantly alleviated by JNJ7777120 which also eliminated AVL-induced increases in exploratory behavior in an open field. The numbers of OXA-labeled neurons in the hypothalamus were significantly increased in the AVL animals at 72 h post-AVL and in the IVL animals at 24, 48, and 72 h post-IVL. SB334867 significantly attenuated the vestibular deficit syndrome and locomotor hyperactivity at 72 h post-AVL and IVL. It also decreased exploratory behavior in the AVL animals. These results suggested that the alteration of OXA expression might contribute to locomotor abnormalities after acute vestibular lesion. The orexin receptors might be the potential therapeutic targets for vestibular disorders. PMID:27507932

  7. Vestibular stimulation by magnetic fields

    PubMed Central

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

    2015-01-01

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

  8. Procedures for restoring vestibular disorders

    PubMed Central

    Walther, Leif Erik

    2005-01-01

    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 (Tab. 1) and 2 (Tab. 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

  9. Amiloride Clinical Trial In Optic Neuritis (ACTION) protocol: a randomised, double blind, placebo controlled trial

    PubMed Central

    McKee, Justin B; Elston, John; Evangelou, Nikos; Gerry, Stephen; Fugger, Lars; Kennard, Christopher; Kong, Yazhuo; Palace, Jacqueline; Craner, Matthew

    2015-01-01

    Introduction Neurodegeneration is a widely accepted contributor to the development of long-term disability in multiple sclerosis (MS). While current therapies in MS predominantly target inflammation and reduce relapse rate they have been less effective at preventing long-term disability. The identification and evaluation of effective neuroprotective therapies within a trial paradigm are key unmet needs. Emerging evidence supports amiloride, a licenced diuretic, as a neuroprotective agent in MS through acid sensing ion channel blockade. Optic neuritis (ON) is a common manifestation of MS with correlates of inflammation and neurodegeneration measurable within the visual pathways. Amiloride Clinical Trial In Optic Neuritis (ACTION) will utilise a multimodal approach to assess the neuroprotective efficacy of amiloride in acute ON. Methods and analysis 46 patients will be recruited within 28 days from onset of ON visual symptoms and randomised on a 1:1 basis to placebo or amiloride 10 mg daily. Double-blinded treatment groups will be balanced for age, sex and visual loss severity by a random-deterministic minimisation algorithm. The primary objective is to demonstrate that amiloride is neuroprotective in ON as assessed by scanning laser polarimetry of the peripapillary retinal nerve fibre layer (RNFL) thickness at 6 months in the affected eye compared to the unaffected eye at baseline. RNFL in combination with further retinal measures will also be assessed by optical coherence tomography. Secondary outcome measures on brain MRI will include cortical volume, diffusion-weighted imaging, resting state functional MRI, MR spectroscopy and magnetisation transfer ratio. In addition, high and low contrast visual acuity, visual fields, colour vision and electrophysiology will be assessed alongside quality of life measures. Ethics and dissemination Ethical approval was given by the south central Oxford B research ethics committee (REC reference: 13/SC/0022). The findings

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

    PubMed

    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

  11. Unusual Presentation of Unilateral Isolated Probable Lyme Optic Neuritis

    PubMed Central

    Burakgazi, Ahmet Z.; Henderson, Carl S.

    2016-01-01

    Optic neuritis (ON) is one of the most common manifestations of central nervous system involvement caused by various etiologies. Lyme ON is an exceedingly rare ocular manifestation of Lyme disease (LD) and only a few cases have been published in the literature. Lyme ON is very rare but should be included in the differential diagnosis in unexplained cases, particularly in Lyme endemic areas. Careful and detailed examination and investigation are warranted to make the diagnosis. We report this case to increase awareness of clinicians to include Lyme disease in differential diagnosis of ON for unexplained cases of ON. Herein we present a unique case with a unilateral ON caused by LD along with pre- and posttreatment findings and literature review. PMID:26953086

  12. Unusual Presentation of Unilateral Isolated Probable Lyme Optic Neuritis.

    PubMed

    Burakgazi, Ahmet Z; Henderson, Carl S

    2016-01-01

    Optic neuritis (ON) is one of the most common manifestations of central nervous system involvement caused by various etiologies. Lyme ON is an exceedingly rare ocular manifestation of Lyme disease (LD) and only a few cases have been published in the literature. Lyme ON is very rare but should be included in the differential diagnosis in unexplained cases, particularly in Lyme endemic areas. Careful and detailed examination and investigation are warranted to make the diagnosis. We report this case to increase awareness of clinicians to include Lyme disease in differential diagnosis of ON for unexplained cases of ON. Herein we present a unique case with a unilateral ON caused by LD along with pre- and posttreatment findings and literature review. PMID:26953086

  13. Negative emotional stimuli enhance vestibular processing.

    PubMed

    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

  14. Multimodality evoked potentials and electrically elicited blink reflex in optic neuritis.

    PubMed

    Tackmann, W; Ettlin, T; Strenge, H

    1982-01-01

    Pattern shift visual evoked potentials, brain stem auditory evoked potentials, spinal and scalp recorded somatosensory evoked potentials, and electrically elicited blink reflexes were investigated in 32 patients with isolated optic neuritis. Eleven patients were shown to have one additional lesion in the central nervous system outside the optic nerve. Therefore, cases with optic neuritis of unknown origin should be considered as possible cases of multiple sclerosis. PMID:6181223

  15. In vivo detection of experimental optic neuritis by pupillometry.

    PubMed

    Shindler, Kenneth S; Revere, Karen; Dutt, Mahasweta; Ying, Gui-Shuang; Chung, Daniel C

    2012-07-01

    Optic neuritis is an inflammatory demyelination of optic nerve often occurring in multiple sclerosis (MS) patients. Mice with experimental autoimmune encephalomyelitis (EAE), an MS model, develop optic neuritis, but it is detected histologically after sacrifice, limiting the ability to monitor progression or treatment in vivo. We examined whether pupillary light responses measured by pupillometry can identify eyes with optic neuritis in EAE mice. C57BL/6 mice were exposed to unilateral light flashes of increasing intensity at 10 s intervals (4.7, 37, and 300 μW/cm(2)). Pupillary responses were recorded with a commercially available pupillometer. EAE was then induced by immunization with myelin oligodendrocyte glycoprotein. Pupillometry was repeated up to 17 days post-immunization, and responses were correlated with optic nerve inflammation. By day 17 post-immunization, 90% of EAE eyes had optic nerve inflammation. EAE eyes had significantly reduced pupillary constriction compared to control eyes. Mice exhibited more than a 25% decrease in pupillary constriction in at least one eye by days 13-15 post-immunization. In some eyes, pupil responses decreased prior to onset of detectable inflammation. Results show that pupillometry detects decreased optic nerve function in experimental optic neuritis, even in the absence of histological detection. Measuring pupillary constriction allows in vivo identification and functional assessment of eyes with optic neuritis that will be useful in evaluating potential therapies over time. Furthermore, results demonstrate that decreased visual function occurs early in optic neuritis, before optic nerve inflammation reaches its peak level. PMID:22561341

  16. Towards a neuromorphic vestibular system.

    PubMed

    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

  17. The Vestibular Implant: Quo Vadis?

    PubMed Central

    van de Berg, Raymond; Guinand, Nils; Stokroos, Robert J.; Guyot, Jean-Philippe; Kingma, Herman

    2011-01-01

    Objective: To assess the progress of the development of the vestibular implant (VI) and its feasibility short-term. Data sources: A search was performed in Pubmed, Medline, and Embase. Key words used were “vestibular prosth*” and “VI.” The only search limit was language: English or Dutch. Additional sources were medical books, conference lectures and our personal experience with per-operative vestibular stimulation in patients selected for cochlear implantation. Study selection: All studies about the VI and related topics were included and evaluated by two reviewers. No study was excluded since every study investigated different aspects of the VI. 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 VI 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. PMID:21991260

  18. Vestibular Findings in Military Band Musicians

    PubMed Central

    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

    2014-01-01

    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

  19. Vestibular Stimulation for Stress Management in Students

    PubMed Central

    Kumar, Sai Sailesh; Rajagopalan, Archana

    2016-01-01

    Introduction Although several methods are developed to alleviate stress among college students, logistic limitations in adopting them have limited their utility. Aim Hence, we aimed to test a very practical approach to alleviate stress among college students by achieving vestibular stimulation using swings. Materials and Methods In this study 60 male and female participants were randomly assigned into vestibular stimulation or control groups. Depression, anxiety, stress scores, sleep quality, heart rate, blood pressure, Autonomic functions, respiratory, haematological, cognitive function, Quality of life were recorded before and after 1st, 7th, 14th, 21st, 28th days of vestibular stimulation. Results STAI S and STAI T scores were significantly improved on day 28th following vestibular stimulation. Diastolic and mean arterial blood pressure were significantly decreased and remained within normal limits in vestibular group on day 28th following vestibular stimulation. Postural fall in blood pressure was significantly improved on day 14 onwards, following vestibular stimulation. Respiratory rate was significantly improved on day 7 onwards, following vestibular stimulation. PSQI sleep disturbance, PSQI sleep latency, PSQI total score and bleeding time was significantly improved following vestibular stimulation. Conclusion Our study supports the adoption of vestibular stimulation for stress management. Hence, placement of swings in college campuses must be considered, which may be a simple approach to alleviate stress among college students. PMID:27042457

  20. Current Treatment Options in Vestibular Migraine

    PubMed Central

    Obermann, Mark; Strupp, Michael

    2014-01-01

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

  1. Molecular aging of the mammalian vestibular system.

    PubMed

    Brosel, Sonja; Laub, Christoph; Averdam, Anne; Bender, Andreas; Elstner, Matthias

    2016-03-01

    Dizziness and imbalance frequently affect the elderly and contribute to falls and frailty. In many geriatric patients, clinical testing uncovers a dysfunction of the vestibular system, but no specific etiology can be identified. Neuropathological studies have demonstrated age-related degeneration of peripheral and central vestibular neurons, but the molecular mechanisms are poorly understood. In contrast, recent studies into age-related hearing loss strongly implicate mitochondrial dysfunction, oxidative stress and apoptotic cell death of cochlear hair cells. While some data suggest that analogous biological pathomechanisms may underlie vestibular dysfunction, actual proof is missing. In this review, we summarize the available data on the molecular causes of vestibular dysfunction. PMID:26739358

  2. A vestibular phenotype for Waardenburg syndrome?

    NASA Technical Reports Server (NTRS)

    Black, F. O.; Pesznecker, S. C.; Allen, K.; Gianna, C.

    2001-01-01

    OBJECTIVE: To investigate vestibular abnormalities in subjects with Waardenburg syndrome. STUDY DESIGN: Retrospective record review. SETTING: Tertiary referral neurotology clinic. SUBJECTS: Twenty-two adult white subjects with clinical diagnosis of Waardenburg syndrome (10 type I and 12 type II). INTERVENTIONS: Evaluation for Waardenburg phenotype, history of vestibular and auditory symptoms, tests of vestibular and auditory function. MAIN OUTCOME MEASURES: Results of phenotyping, results of vestibular and auditory symptom review (history), results of vestibular and auditory function testing. RESULTS: Seventeen subjects were women, and 5 were men. Their ages ranged from 21 to 58 years (mean, 38 years). Sixteen of the 22 subjects sought treatment for vertigo, dizziness, or imbalance. For subjects with vestibular symptoms, the results of vestibuloocular tests (calorics, vestibular autorotation, and/or pseudorandom rotation) were abnormal in 77%, and the results of vestibulospinal function tests (computerized dynamic posturography, EquiTest) were abnormal in 57%, but there were no specific patterns of abnormality. Six had objective sensorineural hearing loss. Thirteen had an elevated summating/action potential (>0.40) on electrocochleography. All subjects except those with severe hearing loss (n = 3) had normal auditory brainstem response results. CONCLUSION: Patients with Waardenburg syndrome may experience primarily vestibular symptoms without hearing loss. Electrocochleography and vestibular function tests appear to be the most sensitive measures of otologic abnormalities in such patients.

  3. Vestibular Function Research aboard Spacelab

    NASA Technical Reports Server (NTRS)

    Mah, R. W.; Daunton, N. G.

    1978-01-01

    NASA is planning to perform a series of Vestibular Function Research (VFR) investigations on the early STS missions to investigate those neurosensory and related physiological processes believed to be associated with the space flight nausea syndrome. The first flight is scheduled for the 1981 Spacelab III Mission in which four frog specimens, mounted on a frog tilting/centrifuge device, will be subjected to periodic acceleration stimuli and periods of artificial gravity. The vestibular nerve firing responses of each frog specimen will be monitored through implanted neutral bouyancy microelectrodes and transmitted to the ground for quick analysis during the flight. The experimentation will be directed at investigating: (1) adaptation to weightlessness; (2) response to acceleration stimuli; (3) response to artificial gravity (in a weightlessness environment) and (4) readaptation to earth's gravity upon return.

  4. Occupational noise induced vestibular malfunction?

    PubMed Central

    Hinchcliffe, R; Coles, R R; King, P F

    1992-01-01

    This paper comprises a review of the evidence for the possibility that exposure to noise may damage the vestibular receptors in the internal ear as well as those in the cochlea. The review covers lay and medical publications, observations on patients, experimental studies, and compensation claims. It concludes that the verdict must be "not proven"--that is, although such damage is possible, the evidence is not strong enough to regard it as probable. PMID:1733458

  5. Vestibular-related neuroscience and manned space flight

    NASA Technical Reports Server (NTRS)

    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.

  6. Ultrasonography in distinguishing optic neuritis from nonarteritic anterior ischemic optic neuropathy

    PubMed Central

    Dehghani, Alireza; Giti, Masoomeh; Akhlaghi, Mohamad Reza; Karami, Mehdi; Salehi, Fatemeh

    2012-01-01

    Background and Objectives: Optic neuritis (ON) and nonarteritic anterior ischemic optic neuropathy (NAION) have some overlapping clinical profiles. We evaluated the usefulness of B-scan ultrasonography in distinguishing ON from NAION by measuring diameter of the optic nerve. Materials and Methods: Consecutive patients with an acute noncompressive unilateral optic neuropathy with relative afferent pupillary defect and onset of visual loss during the last 2 weeks were included. Diagnosis of ON was based on age ≤ 35 years, orbital pain associated with eye movement, and no disk edema, and diagnosis of NAION was based on age ≥ 60 years, no orbital pain associated with eye movement, and presence of disk edema. Age- and gender-matched subjects without ocular disease were selected for comparison. The diameter of the optic nerve was measured by a single radiologist with B-scan ultrasonography. Results: In ON patients, the mean diameter of the affected nerve was significantly larger than that of the unaffected nerve and also larger than that of the right nerve of young controls; P < 0.05. In NAION patients, however, there was no significant difference between the mean diameter of the affected nerve and of the unaffected nerve or the right nerve of elderly controls; P > 0.05. Also, the diameter of the affected nerve was significantly larger in ON than in AION patients; P < 0.05. Conclusion: B-scan ultrasonography is helpful in the early stages of optic neuropathy to distinguish ON from NAION in those cases for which the diagnosis is still uncertain after clinical evaluation. PMID:23210062

  7. Retrobulbar optic neuritis and meningoencephalitis following progressive outer retinal necrosis due to CMV in a patient with AIDS.

    PubMed

    Park, K H; Bang, J H; Park, W B; Kim, H B; Kim, N J; Ahn, J K; Chang, K H; Oh, M D; Choe, K W

    2008-10-01

    We report on a 34-year-old male patient with AIDS who developed retrobulbar optic neuritis and meningoencephalitis following bilateral progressive outer retinal necrosis (PORN) caused by cytomegalovirus (CMV). This case documents the presumed association of PORN with retrobulbar optic neuritis, and CMV meningoencephalitis in an AIDS patient. PMID:18574556

  8. Idiopathic brachial plexus neuritis after laparoscopic treatment of endometriosis: a complication that may mimic position-related brachial plexus injury.

    PubMed

    Minas, Vasileios; Aust, Thomas

    2013-01-01

    We report the case of a 37-year-old woman who developed idiopathic brachial plexus neuritis, also referred to as Parsonage-Turner syndrome, after laparoscopic excision of endometriosis. The differential diagnosis between this non-position-related neuritis and brachial plexus injury is discussed. The aim of this report was to raise awareness on this distressing postoperative complication. PMID:24183278

  9. Changing perspective: The role of vestibular signals.

    PubMed

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

    2015-12-01

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

  10. Compensation of Vestibular Function and Plasticity of Vestibular Nucleus after Unilateral Cochleostomy

    PubMed Central

    Suh, Myung-Whan; Hyun, Jaihwan; Lyu, Ah-Ra; Kim, Dong Woon; Park, Sung Jae; Choi, Jin Woong; Hur, Gang Min

    2016-01-01

    Dizziness and vertigo frequently occur after cochlear implantation (CI) surgery, particularly during the early stages. It could recover over time but some of the patients suffered from delayed or sustained vestibular symptoms after CI. This study used rat animal models to investigate the effect of unilateral cochleostomy on the vestibular organs over time. Twenty-seven Sprague Dawley rats underwent cochleostomy to evaluate the postoperative changes in hearing threshold, gain and symmetry of the vestibular ocular response, overall balance function, number of hair cells in the crista, and the c-Fos activity in the brainstem vestibular nucleus. Loss of vestibular function was observed during the early stages, but function recovered partially over time. Histopathological findings demonstrated a mild decrease in vestibular hair cells numbers. Increased c-Fos immunoreactivity in the vestibular nucleus, observed in the early stages after cochleostomy, decreased over time. Cochleostomy is a risk factor for peripheral vestibular organ damage that can cause functional impairment in the peripheral vestibular organs. Altered vestibular nucleus activity may be associated with vestibular compensation and plasticity after unilateral cochleostomy. PMID:26881130

  11. [Vestibular influences on human locomotion: results obtained using galvanic vestibular stimulation].

    PubMed

    Stolbkov, Iu K; Gerasimenko, Iu P

    2014-06-01

    Locomotion is the most important mode of our movement in space. The role of the vestibular system during human locomotion is not well studied, mainly due to problems associated with its isolation stimulation. It is difficult to stimulate this system in isolation during locomotion because the real movement of the head to activate the vestibular end-organs inevitably leads to the activation of other sensory inputs. Galvanic stimulation is not a natural way to stimulate the vestibular system, but it has the advantage providing an isolated stimulation of the vestibular inputs. This technique is relatively novel in the examination of vestibular contributions during human locomotion. In our review we consider the current data regarding the effect of vestibular signals on human locomotion by using galvanic vestibular stimulation. PMID:25665394

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-02-01

    When we walk in our environment, we readily determine our travelled distance and location using visual cues. In the dark, estimating travelled distance uses a combination of somatosensory and vestibular (i.e., inertial) cues. The observed inability of patients with complete peripheral vestibular failure to update their angular travelled distance during active or passive turns in the dark implies a privileged role for vestibular cues during human angular orientation. As vestibular signals only provide inertial cues of self-motion (e.g., velocity, °/s), the brain must convert motion information to distance information (a process called 'path integration') to maintain our spatial orientation during self-motion in the dark. It is unknown, however, what brain areas are involved in converting vestibular-motion signals to those that enable such vestibular-spatial orientation. Hence, using voxel-based lesion-symptom mapping techniques, we explored the effect of acute right hemisphere lesions in 18 patients on perceived angular position, velocity and motion duration during whole-body angular rotations in the dark. First, compared to healthy controls' spatial orientation performance, we found that of the 18 acute stroke patients tested, only the four patients with damage to the temporoparietal junction showed impaired spatial orientation performance for leftward (contralesional) compared to rightward (ipsilesional) rotations. Second, only patients with temporoparietal junction damage showed a congruent underestimation in both their travelled distance (perceived as shorter) and motion duration (perceived as briefer) for leftward compared to rightward rotations. All 18 lesion patients tested showed normal self-motion perception. These data suggest that the cerebral cortical regions mediating vestibular-motion ('am I moving?') and vestibular-spatial perception ('where am I?') are distinct. Furthermore, the congruent contralesional deficit in time (motion duration) and position

  14. Unilateral peripheral vestibular disorders in the emergency room of the ENT Department of Cluj-Napoca, Romania

    PubMed Central

    PETRI, MARIA; CHIRILA, MAGDALENA; BOLBOACA, SORANA; COSGAREA, MARCEL

    2015-01-01

    Objective To asses the management of unilateral peripheral vestibular disorders in the emergency room of the ENT Department of Cluj-Napoca, Romania. Material and method The study was prospective, non-randomized, and included the patients presented for dizziness or balance disorders at the emergency room of the ENT Department between March 2012 and March 2013. Demographic characteristics, specific clinical history, the onset of peripheral vestibular disorders, and co-morbidities were recorded. The patients charts included the type of onset and the treatment (medical, surgical, and rehabilitation) performed in the emergency room or, in case of hospital admission, the relieving measures for the vestibular symptoms with or without hearing recovery. Results One hundred and fifty-two subjects were included in our study, 97 with pure peripheral vestibular dysfunction (VD), 34 with cochlear-vestibular dysfunction (CVD), and 21 with Ménière’s disease (MD). No significant differences were identified when the proportion of patients with a certain onset (acute, subacute or chronic) were compared. Hypertension was the most frequent co-morbidity in all investigated groups. No significant difference was observed when the relief of vertigo or hearing recovery were compared between all groups. Conclusion This first Romanian report on the management of unilateral peripheral vestibular disorders showed that early corticosteroids treatment associated with electrolytes, antiemetic, and vasodilation drugs led to the recovery of the vestibular function without any differences between the types of peripheral vestibular dysfunction. In addition, we obtained the complete recovery of the vestibular and acoustic dysfunction in the cases treated with metylprednisolone intratympanic injection. PMID:26528069

  15. Unilateral Optic Neuritis: A Rare Complication after Measles-Mumps-Rubella Vaccination in a 30-Year-Old Woman.

    PubMed

    De Giacinto, Chiara; Guaglione, Elvira; Leon, Pia E; D'Aloisio, Rossella; Vattovani, Odilla; Ravalico, Giuseppe; Tognetto, Daniele

    2016-01-01

    Purpose. To report a case of unilateral optic neuritis following Measles-Mumps-Rubella (MMR) vaccination. Methods. A 30-year-old female developed unilateral optic neuritis five days after a Measles-Mumps-Rubella (MMR) booster vaccination. The patient displayed unilateral involvement, with severe visual loss. However, visual acuity improved significantly after four days of intravenous steroid therapy with 500 mg/day of methylprednisolone. Conclusions. Optic neuritis is one of the rare complications associated with the mumps, measles, and rubella vaccine. It may be a toxic reaction to the nonviral component of the vaccine, but the exact etiology is unknown. Postvaccination neuritis is generally bilateral and usually affects children. In adults, unilateral optic neuritis is usually correlated with multiple sclerosis (MS). PMID:27195163

  16. Unilateral Optic Neuritis: A Rare Complication after Measles-Mumps-Rubella Vaccination in a 30-Year-Old Woman

    PubMed Central

    De Giacinto, Chiara; Guaglione, Elvira; Leon, Pia E.; D'Aloisio, Rossella; Vattovani, Odilla; Ravalico, Giuseppe; Tognetto, Daniele

    2016-01-01

    Purpose. To report a case of unilateral optic neuritis following Measles-Mumps-Rubella (MMR) vaccination. Methods. A 30-year-old female developed unilateral optic neuritis five days after a Measles-Mumps-Rubella (MMR) booster vaccination. The patient displayed unilateral involvement, with severe visual loss. However, visual acuity improved significantly after four days of intravenous steroid therapy with 500 mg/day of methylprednisolone. Conclusions. Optic neuritis is one of the rare complications associated with the mumps, measles, and rubella vaccine. It may be a toxic reaction to the nonviral component of the vaccine, but the exact etiology is unknown. Postvaccination neuritis is generally bilateral and usually affects children. In adults, unilateral optic neuritis is usually correlated with multiple sclerosis (MS). PMID:27195163

  17. Brachial Plexus Neuritis Associated With Streptococcus agalactiae Infection: A Case Report.

    PubMed

    Seo, Yu Jung; Lee, Yu Jin; Kim, Joon Sung; Lim, Seong Hoon; Hong, Bo Young

    2014-08-01

    Brachial plexus neuritis is reportedly caused by various factors; however, it has not been described in association with Streptococcus agalactiae. This is a case report of a patient diagnosed with brachial plexus neuritis associated with pyogenic arthritis of the shoulder. A 57-year-old man visited the hospital complaining of sudden weakness and painful swelling of the left arm. The diagnosis was pyogenic arthritis of the left shoulder, and the patient was treated with open irrigation and debridement accompanied by intravenous antibiotic therapy. S. agalactiae was isolated from a wound culture, and an electrodiagnostic study showed brachial plexopathy involving the left upper and middle trunk. Nine weeks after onset, muscle strength improved in most of the affected muscles, and an electrodiagnostic study showed signs of reinnervation. In conclusion, S. agalactiae infection can lead to various complications including brachial plexus neuritis. PMID:25229037

  18. Brachial Plexus Neuritis Associated With Streptococcus agalactiae Infection: A Case Report

    PubMed Central

    Seo, Yu Jung; Lee, Yu Jin; Kim, Joon Sung; Lim, Seong Hoon

    2014-01-01

    Brachial plexus neuritis is reportedly caused by various factors; however, it has not been described in association with Streptococcus agalactiae. This is a case report of a patient diagnosed with brachial plexus neuritis associated with pyogenic arthritis of the shoulder. A 57-year-old man visited the hospital complaining of sudden weakness and painful swelling of the left arm. The diagnosis was pyogenic arthritis of the left shoulder, and the patient was treated with open irrigation and debridement accompanied by intravenous antibiotic therapy. S. agalactiae was isolated from a wound culture, and an electrodiagnostic study showed brachial plexopathy involving the left upper and middle trunk. Nine weeks after onset, muscle strength improved in most of the affected muscles, and an electrodiagnostic study showed signs of reinnervation. In conclusion, S. agalactiae infection can lead to various complications including brachial plexus neuritis. PMID:25229037

  19. Advances in Auditory and Vestibular Medicine

    PubMed Central

    Trune, Dennis R.; Dutia, Mayank B.

    2010-01-01

    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. PMID:20711412

  20. [Vestibular disorders in presenile and senile patients].

    PubMed

    Luchikhin, L A; Derevianko, S N; Ganichkina, I Ia

    2000-01-01

    Vestibular function and dynamic vision were studied in healthy subjects over 60 years of age using functional tests based on computer stabilography. The vestibuloocular reflex was analysed in the test with highly active head shaking. A decline in vestibular function efficiency, somatosensory dissociations were found. Specific features of vestibuloocular interaction in the older patients are shown. PMID:11187067

  1. Vestibular-visual interactions in flight simulators

    NASA Technical Reports Server (NTRS)

    Clark, B.

    1977-01-01

    The following research work is reported: (1) vestibular-visual interactions; (2) flight management and crew system interactions; (3) peripheral cue utilization in simulation technology; (4) control of signs and symptoms of motion sickness; (5) auditory cue utilization in flight simulators, and (6) vestibular function: Animal experiments.

  2. Vestibular assistance systems: promises and challenges.

    PubMed

    Guyot, Jean-Philippe; Perez Fornos, A; Guinand, N; van de Berg, R; Stokroos, R; Kingma, H

    2016-04-01

    The handicap resulting from a bilateral vestibular deficit is often underestimated. In most cases the deficit settles gradually. Patients do not understand what is happening to them and have many difficulties to describe their symptoms. They have to consult several doctors with different medical specialties before diagnosis. Once the diagnosis is made there is no biological way to "repair" the deficient vestibular apparatus and vestibular exercises are mildly effective. Attempts have been made to help patients using substitution devices replacing the defective vestibular information by tactile or acoustic cues. Currently, efforts are being made towards the development of a vestibular implant, conceptually similar to the cochlear implant for the rehabilitation of deaf patients. In recent years, several experiments on animal models have demonstrated the feasibility of this project. This paper reports the steps accomplished in human experiments and the main results obtained in our laboratory. PMID:27083882

  3. The pathogenesis of optic neuritis caused by Angiostrongylus cantonensis in BALB/c mice

    PubMed Central

    2014-01-01

    Background One of the most common causes of meningitis in South East Asia is angiostrongyliasis or infection by the parasitic nematode Angiostrongyliasis cantonensis. Although this nematode usually resides in the pulmonary arteries of rats, its incidental occurence in other hosts such as humans can cause optic neuritis and lead to serious vision sequelae. Nevertheless, there are currently no systematic studies conducted in this area. Methods In order to study the pathogenesis of optic neuritis, mice were tried as a new animal model to study and challenge with A. cantonensis on 7d, 14d and 21d, respectively. Electroretinogram (ERG), visual evoked potential (VEP), ophthalmoscopy and histology were examined on day 7d, 14d and 21d and tribendimidine (TBD) was later used to treat optic neuritis on day 14d for a week to evaluate its therapeutic effects. Results Infection of A. cantonensis caused obvious inflammatory cell infiltration in the retina and optic nerve adventitia in day 14d and 21d followed by optic nerve fiber demyelination and retinal ganglion swelling at day 21d in the challenged mice. Prolonged VEP latency and decreased ERG amplitude were also observed on day 21. After treatment of TBD in the infected mice, retinal and optic nerve inflammation were alleviated, but VEP latency and ERG amplitude did not improve on day 21d and 28d. Conclusions The current study provides evidence that A. cantonensis can cause optic neuritis along with optic nerve demyelination and retinal ganglion cell damage in a mouse model. TBD alone treatment can improve the symptoms of optic neuritis, but does not aid in vision recovery, suggesting that both neuroprotective agents and Dexamethasone should be administered, along with treatment for the infection, to protect the optic nerve and ganglion cells. Furthermore, as the symptoms of optic neuritis caused by A. cantonensis in mice are similar to the optic neuritis in multiple sclerosis (MS) human patients, we suggest that the BALB

  4. Bilateral optic neuritis in a child following Epstein-Barr virus infection.

    PubMed

    Pahor, Dusica

    2005-01-01

    A rare case of bilateral optic neuritis is presented in a child with no light perception. Ophthalmic examination revealed dilated pupils without reaction to the light, swollen optic discs with small peripapillary hemorrhages in both eyes. Serology revealed evidence of recent Epstein-Barr virus infection. After treatment with high dose of corticosteroid visual acuity gradually improved. After four months visual acuity was normal despite complete pallor of the optic disc. Ebstein-Barr virus infection should be considered in the differential diagnosis of bilateral optic neuritis in a child with severe bilateral visual loss. PMID:16193695

  5. Neuroprotective effect of melatonin in experimental optic neuritis in rats.

    PubMed

    Aranda, Marcos L; González Fleitas, María F; De Laurentiis, Andrea; Keller Sarmiento, María I; Chianelli, Mónica; Sande, Pablo H; Dorfman, Damián; Rosenstein, Ruth E

    2016-04-01

    Optic neuritis (ON) is an inflammatory, demyelinating, and neurodegenerative condition of the optic nerve, which might induce permanent vision loss. Currently, there are no effective therapies for this disorder. We have developed an experimental model of primary ON in rats through a single microinjection of 4.5 μg of bacterial lipopolysaccharide (LPS) into the optic nerve. Since melatonin acts as a pleiotropic therapeutic agent in various neurodegenerative diseases, we analyzed the effect of melatonin on LPS-induced ON. For this purpose, LPS or vehicle were injected into the optic nerve from adult male Wistar rats. One group of animals received a subcutaneous pellet of 20 mg melatonin at 24 hr before vehicle or LPS injection, and another group was submitted to a sham procedure. Melatonin completely prevented the decrease in visual evoked potentials (VEPs), and pupil light reflex (PLR), and preserved anterograde transport of cholera toxin β-subunit from the retina to the superior colliculus. Moreover, melatonin prevented microglial reactivity (ED1-immunoreactivity, P < 0.01), astrocytosis (glial fibrillary acid protein-immunostaining, P < 0.05), demyelination (luxol fast blue staining, P < 0.01), and axon (toluidine blue staining, P < 0.01) and retinal ganglion cell (Brn3a-immunoreactivity, P < 0.01) loss, induced by LPS. Melatonin completely prevented the increase in nitric oxide synthase 2, cyclooxygenase-2 levels (Western blot) and TNFα levels, and partly prevented lipid peroxidation induced by experimental ON. When the pellet of melatonin was implanted at 4 days postinjection of LPS, it completely reversed the decrease in VEPs and PLR. These data suggest that melatonin could be a promising candidate for ON treatment. PMID:26882296

  6. Management of sporadic vestibular schwannoma.

    PubMed

    Carlson, Matthew L; Link, Michael J; Wanna, George B; Driscoll, Colin L W

    2015-06-01

    Vestibular schwannomas (VS) comprise 8% of all intracranial tumors and 90% of cerebellopontine angle and internal auditory canal neoplasms. Secondary to the widespread adoption of screening protocols for asymmetrical hearing loss and the increasing use of advanced imaging, the number of VS diagnosed each year continues to rise, while the average size has declined. Microsurgery remains the treatment of choice for large tumors, however the management of small- to medium-sized VS remains highly controversial with options including observation, radiotherapy, or microsurgery. Within this chapter, the authors provide an overview of the contemporary management of VS, reviewing important considerations and common controversies. PMID:25886814

  7. Adaptive modification of vestibularly perceived rotation.

    PubMed

    Bloomberg, J; Melvill Jones, G; Segal, B

    1991-01-01

    Results from Bloomberg et al. (1991) led to the hypothesis that saccades which accompany the dark-tested vestibulo-ocular reflex (VOR) tend to move the eyes towards a vestibularly derived percept of an intended oculomotor goal: also that this is so even when that percept has been adaptively modified by suitably prolonged visual-vestibular conflict. The present experiments investigate these implications by comparing the combined VOR + saccade performance with a presumed "motor readout" of the normal and adaptively modified vestibular percept. The methods employed were similar to those of an earlier study Bloomberg et al. (1988) in which it was found that after cessation of a brief passive whole body rotation in the dark, a previously seen earth-fixed target can be accurately located by saccadic eye movements based on a vestibular memory of the preceding head rotation; the so-called "Vestibular Memory-Contingent Saccade" (VMCS) paradigm. The results showed that the vestibular perceptual response, as measured after rotation by means of the VMCS paradigm, was on average indistinguishable from the combined VOR + saccade response measured during rotation. Furthermore, this was so in both the normal and adapted states. We conclude that these findings substantiate the above hypothesis. The results incidentally reaffirm the adaptive modifiability of vestibular perception, emphasing the need for active maintenance of its proper calibration according to behavioural context. PMID:1855564

  8. Influence of cochlear implantation on vestibular function.

    PubMed

    Chen, Xiulan; Chen, Xiaohua; Zhang, Fan; Qin, Zhaobing

    2016-07-01

    Conclusion Vestibular function in patients can be damaged following cochlear implantation. Therefore, assessing the pre-operative vestibular status, carefully choosing the side of implantation, and preserving function by using minimally invasive surgical techniques are important. Objectives The aim of this study was to assess the influence of cochlear implantation on vestibular function in patients with severe and profound sensorineural hearing loss, and to analyze a possible correlation between the changes in vestibular testing and post-operative vestibular symptoms. Methods Thirty-four patients were evaluated for vestibular function using the cervical and ocular vestibular-evoked myogenic potentials (cVEMP and oVEMP, respectively), and 29 patients underwent caloric tests pre-operatively and 4 weeks post-operatively. Results Before surgery, the cVEMPs were recorded bilaterally in 22 patients, unilaterally in eight patients, and absent bilaterally in four patients. The oVEMPs were recorded bilaterally in 19 patients, unilaterally in six patients, and absent bilaterally in nine patients. After implantation, the cVEMPs were absent in 10 patients and the oVEMPs were absent in seven patients on the implanted side. Caloric tests demonstrated canal paresis in 17 patients, and normal responses were recorded in 12 of the 29 patients pre-operatively. There was a significant decrease post-implantation in the ear implanted, with the exception of two patients. Two patients presented with vertigo and another two patients reported slight unsteadiness post-operatively, but all symptoms resolved within 7 days. The impaired vestibular function did not correlate with vestibular symptoms, age, or gender. Function on the contralateral side remained unaffected. PMID:27008103

  9. Aging of the Human Vestibular System.

    PubMed

    Zalewski, Christopher K

    2015-08-01

    Aging affects every sensory system in the body, including the vestibular system. Although its impact is often difficult to quantify, the deleterious impact of aging on the vestibular system is serious both medically and economically. The deterioration of the vestibular sensory end organs has been known since the 1970s; however, the measurable impact from these anatomical changes remains elusive. Tests of vestibular function either fall short in their ability to quantify such anatomical deterioration, or they are insensitive to the associated physiologic decline and/or central compensatory mechanisms that accompany the vestibular aging process. When compared with healthy younger individuals, a paucity of subtle differences in test results has been reported in the healthy older population, and those differences are often observed only in response to nontraditional and/or more robust stimuli. In addition, the reported differences are often clinically insignificant insomuch that the recorded physiologic responses from the elderly often fall within the wide normative response ranges identified for normal healthy adults. The damaging economic impact of such vestibular sensory decline manifests itself in an exponential increase in geriatric dizziness and a subsequent higher prevalence of injurious falls. An estimated $10 to $20 billion dollar annual cost has been reported to be associated with falls-related injuries and is the sixth leading cause of death in the elderly population, with a 20% mortality rate. With an estimated 115% increase in the geriatric population over 65 years of age by the year 2050, the number of balanced-disordered patients with a declining vestibular system is certain to reach near epidemic proportions. An understanding of the effects of age on the vestibular system is imperative if clinicians are to better manage elderly patients with balance disorders, dizziness, and vestibular disease. PMID:27516717

  10. Aging of the Human Vestibular System

    PubMed Central

    Zalewski, Christopher K.

    2015-01-01

    Aging affects every sensory system in the body, including the vestibular system. Although its impact is often difficult to quantify, the deleterious impact of aging on the vestibular system is serious both medically and economically. The deterioration of the vestibular sensory end organs has been known since the 1970s; however, the measurable impact from these anatomical changes remains elusive. Tests of vestibular function either fall short in their ability to quantify such anatomical deterioration, or they are insensitive to the associated physiologic decline and/or central compensatory mechanisms that accompany the vestibular aging process. When compared with healthy younger individuals, a paucity of subtle differences in test results has been reported in the healthy older population, and those differences are often observed only in response to nontraditional and/or more robust stimuli. In addition, the reported differences are often clinically insignificant insomuch that the recorded physiologic responses from the elderly often fall within the wide normative response ranges identified for normal healthy adults. The damaging economic impact of such vestibular sensory decline manifests itself in an exponential increase in geriatric dizziness and a subsequent higher prevalence of injurious falls. An estimated $10 to $20 billion dollar annual cost has been reported to be associated with falls-related injuries and is the sixth leading cause of death in the elderly population, with a 20% mortality rate. With an estimated 115% increase in the geriatric population over 65 years of age by the year 2050, the number of balanced-disordered patients with a declining vestibular system is certain to reach near epidemic proportions. An understanding of the effects of age on the vestibular system is imperative if clinicians are to better manage elderly patients with balance disorders, dizziness, and vestibular disease. PMID:27516717

  11. The perception of body verticality (subjective postural vertical) in peripheral and central vestibular disorders.

    PubMed

    Bisdorff, A R; Wolsley, C J; Anastasopoulos, D; Bronstein, A M; Gresty, M A

    1996-10-01

    The perception of body verticality (subjective postural vertical, SPV) was assessed in normal subjects and in patients with peripheral and central vestibular lesions and the data were compared with conventional neuro-otological assessments. Subjects were seated with eyes closed in a motorized gimbal which executed cycles of tilt at low constant speed (1.5 degrees s-1), both in the frontal (roll) and sagittal (pitch) planes. Subjects indicated with a joystick when they entered and left verticality, thus defining a sector of subjective uprightness in each plane. The mean angle of tilt (identifying a bias of the SPV) and the width of the sector (defining sensitivity of the SPV) were then determined. In normal subjects, the angle of the "verticality' sector was 5.9 degrees for pitch and roll. Patients with bilateral absence of vestibular function, patients with vertigo, i.e. acute unilateral lesions, benign paroxysmal positional vertigo (BPPV) and Ménière's disease, and patients with positionally modulated up-/downbeat nystagmus all had enlarged sectors (i.e. loss in sensitivity). Mean sector angle in these groups ranged from 7.8 to 11 degrees and the abnormality was present both in pitch and roll, regardless of the direction of nystagmus or body sway. Patients with chronic unilateral peripheral vestibular lesions and those with position-independent vertical nystagmus had normal sensitivities. No significant bias of the SPV was found in any patient group, not even those with acute unilateral vestibular lesions who had marked tilts of the subjective visual vertical (SVV). Complementary experiments in normal subjects tested under galvanic vestibular or roll-plane optokinetic stimulation also failed to show biases of the SPV. In contrast, a significant bias in the SPV could be induced in normal subjects by asymmetric cycles of gimbals tilt, presumably by proprioceptive adaptation. The following conclusions can be drawn. (i) The perception of body verticality whilst

  12. Bilateral Retrobulbar Optic Neuritis Caused by Varicella Zoster Virus in a Patient with AIDS

    PubMed Central

    Duda, Jose F.; Castro, Jose G.

    2015-01-01

    Aims To report on a case of bilateral retrobulbar optic neuritis in a patient with acquired immune deficiency syndrome (AIDS) caused by varicella-zoster virus (VZV); and to review the literature focusing on: cases reported, epidemiology, pathophysiology, diagnosis and treatment. Presentation of Case A 38-year-old woman with AIDS presented with a 10-day history of progressive bilateral visual loss and ocular pain. She had bilateral dilated pupils with no light perception; the fundoscopic examination was normal. Facial herpes zoster lesions appeared on the second day of hospitalization Magnetic resonance imaging (MRI) findings were compatible with a bilateral optic neuritis; the cerebrospinal fluid (CSF) showed pleocytosis, increased proteins and a positive VZV-DNA PCR. She was treated with intravenous acyclovir and corticosteroids and was able, when discharged 2 weeks after admission, to carry out activities of daily living. Discussion VZV retrobulbar optic neuritis has previously been reported in 12 patients with AIDS, more than half of the cases had concomitant herpes zoster and an associated retinopathy. A positive VZV-DNA in the CSF is indicative of VZV infection, initial use of intravenous acyclovir is recommended, and the concomitant use of corticosteroids would be a prudent choice; the duration of antiviral therapy remains undefined. Conclusion VZV retrobulbar optic neuritis in AIDS patients can occur with or without herpes zoster. It is a sight-threatening infectious and inflammatory process requiring the advice of specialists in infectious diseases, ophthalmology, neurology and viral microbiology. PMID:26740936

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

    PubMed

    Fridman, Gene Y; Della Santina, Charles C

    2012-11-01

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

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

    PubMed Central

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

    2014-01-01

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

  15. Vestibular-induced vomiting after vestibulocerebellar lesions

    NASA Technical Reports Server (NTRS)

    Miller, A. D.; Wilson, V. J.

    1982-01-01

    Vestibular stimulation, by sinusoidal electrical polarization of the labyrinths of decerebrate cats which can produce vomiting and related activity which resembles motion sickness was examined. The symptoms include panting, salivation, swallowing, and retching as well as vomiting. These symptoms can be produced in cats with lesions of the posterior cerebellar vermis. It is suggested that a transcerebellar pathway from the vestibular apparatus through the nodulus and uvula to the vomiting center is not essential for vestibular induced vomiting and the occurrence of many symptoms of motion.

  16. Vestibular-induced vomiting after vestibulocerebellar lesions

    NASA Technical Reports Server (NTRS)

    Miller, A. D.; Wilson, V. J.

    1983-01-01

    Vestibular stimulation, by sinusoidal electrical polarization of the labyrinths of decerebrate cats which can produce vomiting and related activity which resembles motion sickness was examined. The symptoms include panting, salivation, swallowing, and retching as well as vomiting. These symptoms can be produced in cats with lesions of the posterior cerebellar vermis. It is suggested that a transcerebellar pathway from the vestibular apparatus through the nodulus and uvula to the vomiting center is not essential for vestibular induced vomiting and the occurrence of many symptoms of motion.

  17. Vestibular reactions to spaceflight: human factors issues.

    PubMed

    Young, L R

    2000-09-01

    Vestibular function, along with other sensory systems influencing spatial orientation, can have a profound influence on the ability of astronauts to function effectively. Beyond the well-known problems of space motion sickness, vestibular effects can influence astronaut well-being and performance during all phases of a space mission. This paper discusses some of the major vestibular reactions affecting human factors encountered in all space missions, and covers them chronologically in the following sequence: launch, early on-orbit, late on-orbit, EVA, artificial gravity, re-entry, and post-landing. PMID:10993318

  18. Normal and abnormal human vestibular ocular function

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

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

  19. Aquaporin 4 antibody [NMO Ab] status in patients with severe optic neuritis in India.

    PubMed

    Ambika, Selvakumar; Balasubramanian, Mahalakshmi; Theresa, Lily; Veeraputhiran, Akila; Arjundas, Deepak

    2015-12-01

    Neuromyelitis optica (NMO) is an inflammatory demyelinating disease of the central nervous system that causes attacks of optic neuritis and transverse myelitis. The discovery of a specific serum marker for NMO-IgG antibody [aquaporin 4 antibody/AQP4 Ab] has revolutionised the treatment of demyelinating diseases. Severe vision loss can be seen in optic neuritis (ON) associated with both multiple sclerosis (MS) and NMO. Identifying this antibody in optic neuritis patients can help us to establish the likelihood of these patients developing NMO (Jarius et al. Neurol Sci 298:158-162, 2010). It is important to differentiate these two entities as the treatment strategies of MS and NMO are different. To the best of our knowledge, there is no published literature regarding the importance of identifying this antibody in severe optic neuritis in Indian patients. Hence we decided to screen our severe optic neuritis patients for this AQP4 Ab. To investigate the presence of aquaporin 4 antibody and determine its prognostic value for visual and neurological outcome, in patients with bilateral and recurrent [severe] ON without any previous neurological manifestations presenting to a neuro-ophthalmology clinic in India. Single centre, prospective study. 40 patients (27 female patients and 13 male) with severe optic neuritis [patients with no visual improvement by 4 weeks from onset of vision loss] who presented either as recurrent attacks or as bilateral and severe optic neuritis between January 2010 and June 2011 were enrolled. Clinical features, visual outcome and sequential neurological events were compared between the seropositive and the seronegative groups. Aquaporin 4 antibodies were detected from serum using ELISA technique and IIF technique. Presence of this antibody in the serum was considered to be seropositive status and patients who did not have this antibody were considered seronegatives. AQP4 antibodies were detected in 8 of the 40 patients with severe ON (20 %).The

  20. Sequential [(18)F]FDG µPET whole-brain imaging of central vestibular compensation: a model of deafferentation-induced brain plasticity.

    PubMed

    Zwergal, Andreas; Schlichtiger, Julia; Xiong, Guoming; Beck, Roswitha; Günther, Lisa; Schniepp, Roman; Schöberl, Florian; Jahn, Klaus; Brandt, Thomas; Strupp, Michael; Bartenstein, Peter; Dieterich, Marianne; Dutia, Mayank B; la Fougère, Christian

    2016-01-01

    Unilateral inner ear damage is followed by a rapid behavioural recovery due to central vestibular compensation. In this study, we utilized serial [(18)F]Fluoro-deoxyglucose ([(18)F]FDG)-µPET imaging in the rat to visualize changes in brain glucose metabolism during behavioural recovery after surgical and chemical unilateral labyrinthectomy, to determine the extent and time-course of the involvement of different brain regions in vestibular compensation and test previously described hypotheses of underlying mechanisms. Systematic patterns of relative changes of glucose metabolism (rCGM) were observed during vestibular compensation. A significant asymmetry of rCGM appeared in the vestibular nuclei, vestibulocerebellum, thalamus, multisensory vestibular cortex, hippocampus and amygdala in the acute phase of vestibular imbalance (4 h). This was followed by early vestibular compensation over 1-2 days where rCGM re-balanced between the vestibular nuclei, thalami and temporoparietal cortices and bilateral rCGM increase appeared in the hippocampus and amygdala. Subsequently over 2-7 days, rCGM increased in the ipsilesional spinal trigeminal nucleus and later (7-9 days) rCGM increased in the vestibulocerebellum bilaterally and the hypothalamus and persisted in the hippocampus. These systematic dynamic rCGM patterns during vestibular compensation, were confirmed in a second rat model of chemical unilateral labyrinthectomy by serial [(18)F]FDG-µPET. These findings show that deafferentation-induced plasticity after unilateral labyrinthectomy involves early mechanisms of re-balancing predominantly in the brainstem vestibular nuclei but also in thalamo-cortical and limbic areas, and indicate the contribution of spinocerebellar sensory inputs and vestibulocerebellar adaptation at the later stages of behavioural recovery. PMID:25269833

  1. Primal Terror: A Perspective of Vestibular Dysfunction.

    ERIC Educational Resources Information Center

    Shaffer, Martin

    1979-01-01

    The effects of "primal terror", the emotional experience of one's inability to naturally maintain balance in opposition to gravity and to integrate vestibular input, are discussed for children with learning and perceptual problems. (CL)

  2. [Vestibular function: the 6th sense... ignored].

    PubMed

    Guyot, J-P; Guinand, N

    2015-09-30

    Dizzy patients are often misunderstood by doctors. Those with a complete vestibular deficit and whose function is restored by a vestibular implant use all kinds of words to describe what they feel when the neuroprosthesis is turned on. Their feeling varied from a strong emotion to a feeling of heat. The notion of dizziness or motion was rare. How to describe the sensations provided by an ignored and unconscious sense? With the eyes, one sees; with the ears one hears; no term exists that describes what we do with the vestibular system! Should we say we vestibulise? The notion traditionally taught that patients suffering from a vestibular disorder should describe an imbalance or a rotatory vertigo, be able specify the direction of rotation, etc. is inadequate, unrealistic. PMID:26619699

  3. Basic Concepts in Understanding Recovery of Function in Vestibular Reflex Networks during Vestibular Compensation

    PubMed Central

    Peusner, Kenna D.; Shao, Mei; Reddaway, Rebecca; Hirsch, June C.

    2012-01-01

    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. PMID:22363316

  4. Outcome analysis of individualized vestibular rehabilitation protocols

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

  5. Vestibular development in marsupials and monotremes

    PubMed Central

    Ashwell, Ken W S; Shulruf, Boaz

    2014-01-01

    The young of marsupials and monotremes are all born in an immature state, followed by prolonged nurturing by maternal lactation in either a pouch or nest. Nevertheless, the level of locomotor ability required for newborn marsupials and monotremes to reach the safety of the pouch or nest varies considerably: some are transferred to the pouch or nest in an egg (monotremes); others are transferred passively by gravity (e.g. dasyurid marsupials); some have only a horizontal wriggle to make (e.g. peramelid and didelphid marsupials); and others must climb vertically for a long distance to reach the maternal pouch (e.g. diprotodontid marsupials). In the present study, archived sections of the inner ear and hindbrain held in the Bolk, Hill and Hubrecht collections at the Museum für Naturkunde, Berlin, were used to test the relationship between structural maturity of the vestibular apparatus and the locomotor challenges that face the young of these different mammalian groups. A system for staging different levels of structural maturity of the vestibular apparatus was applied to the embryos, pouch young and hatchlings, and correlated with somatic size as indicated by greatest body length. Dasyurids are born at the most immature state, with the vestibular apparatus at little more than the otocyst stage. Peramelids are born with the vestibular apparatus at a more mature state (fully developed semicircular ducts and a ductus reuniens forming between the cochlear duct and saccule, but no semicircular canals). Diprotodontids and monotremes are born with the vestibular apparatus at the most mature state for the non-eutherians (semicircular canals formed, maculae present, but vestibular nuclei in the brainstem not yet differentiated). Monotremes and marsupials reach the later stages of vestibular apparatus development at mean body lengths that lie within the range of those found for laboratory rodents (mouse and rat) reaching the same vestibular stage. PMID:24298911

  6. Vestibular-visual interactions in flight simulators

    NASA Technical Reports Server (NTRS)

    Clark, B.

    1977-01-01

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

  7. Vestibular development in marsupials and monotremes.

    PubMed

    Ashwell, Ken W S; Shulruf, Boaz

    2014-04-01

    The young of marsupials and monotremes are all born in an immature state, followed by prolonged nurturing by maternal lactation in either a pouch or nest. Nevertheless, the level of locomotor ability required for newborn marsupials and monotremes to reach the safety of the pouch or nest varies considerably: some are transferred to the pouch or nest in an egg (monotremes); others are transferred passively by gravity (e.g. dasyurid marsupials); some have only a horizontal wriggle to make (e.g. peramelid and didelphid marsupials); and others must climb vertically for a long distance to reach the maternal pouch (e.g. diprotodontid marsupials). In the present study, archived sections of the inner ear and hindbrain held in the Bolk, Hill and Hubrecht collections at the Museum für Naturkunde, Berlin, were used to test the relationship between structural maturity of the vestibular apparatus and the locomotor challenges that face the young of these different mammalian groups. A system for staging different levels of structural maturity of the vestibular apparatus was applied to the embryos, pouch young and hatchlings, and correlated with somatic size as indicated by greatest body length. Dasyurids are born at the most immature state, with the vestibular apparatus at little more than the otocyst stage. Peramelids are born with the vestibular apparatus at a more mature state (fully developed semicircular ducts and a ductus reuniens forming between the cochlear duct and saccule, but no semicircular canals). Diprotodontids and monotremes are born with the vestibular apparatus at the most mature state for the non-eutherians (semicircular canals formed, maculae present, but vestibular nuclei in the brainstem not yet differentiated). Monotremes and marsupials reach the later stages of vestibular apparatus development at mean body lengths that lie within the range of those found for laboratory rodents (mouse and rat) reaching the same vestibular stage. PMID:24298911

  8. Vestibular ontogeny: Measuring the influence of the dynamic environment

    NASA Technical Reports Server (NTRS)

    Jones, Timothy A.; Devries, Sherri M.; Dubois, Linda M.; Nelson, Rick C.

    1993-01-01

    In comparison to other special senses, we are only meagerly informed about the development of vestibular function and the mechanisms that may operate to control or influence the course of vestibular ontogeny. Perhaps one contributing factor to this disparity is the difficulty of evaluating vestibular sense organs directly and noninvasively. The present report describes a recently developed direct noninvasive vestibular function test that can be used to address many basic questions about the developing vestibular system. More particularly, the test can be used to examine the effects of the dynamic environment (e.g. gravitational field and vibration) on vestibular ontogeny.

  9. Vestibular Impairment in Frontotemporal Dementia Syndrome

    PubMed Central

    Nakamagoe, Kiyotaka; Kadono, Kotarou; Koganezawa, Tadachika; Takiguchi, Mao; Terada, Makoto; Yamamoto, Fumiko; Moriyama, Tetsuya; Yanagiha, Kumi; Nohara, Seitaro; Tozaka, Naoki; Miyake, Zenshi; Aizawa, Satoshi; Furusho, Kentaro; Tamaoka, Akira

    2016-01-01

    Background No studies to date have attempted to evaluate frontotemporal lobar degeneration from the perspective of the vestibular system. Objective The present study examined vestibular function in patients with frontotemporal dementia (FTD) clinical syndrome and evaluated whether vestibular disorders are involved in the clinical symptoms due to FTD. Methods Fourteen patients with FTD syndrome, as well as healthy elderly controls without dementia, were included in the present study. All subjects underwent vestibular function tests using electronystagmography, such as caloric tests and visual suppression (VS) tests, in which the induced caloric nystagmus was suppressed by visual stimuli. The association between clinical symptoms and vestibular function in the FTD syndrome group was further examined. Results In the FTD syndrome group, caloric nystagmus was not necessarily suppressed during VS tests. Furthermore, VS was observed to be significantly impaired in FTD syndrome patients with gait disturbance as compared to those without such disturbance. Conclusion The present study revealed that impairment of VS in patients with FTD results in an inability to regulate vestibular function by means of visual perception, regardless of multiple presumed neuropathological backgrounds. This could also be associated with gait disturbance in patients with FTD syndrome. PMID:27350780

  10. Vestibular stimulation affects optic-flow sensitivity.

    PubMed

    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

  11. Genetics of vestibular disorders: pathophysiological insights.

    PubMed

    Frejo, Lidia; Giegling, Ina; Teggi, Roberto; Lopez-Escamez, Jose A; Rujescu, Dan

    2016-04-01

    The two most common vestibular disorders are motion sickness and vestibular migraine, affecting 30 and 1-2 % of the population respectively. Both are related to migraine and show a familial trend. Bilateral vestibular hypofunction is a rare condition, and some of patients also present cerebellar ataxia and neuropathy. We present recent advances in the genetics of vestibular disorders with familial aggregation. The clinical heterogeneity observed in different relatives of the same families suggests a variable penetrance and the interaction of several genes in each family. Some Mendelian sensorineural hearing loss also exhibits vestibular dysfunction, including DFNA9, DFNA11, DFNA15 and DFNA28. However, the most relevant finding during the past years is the familial clustering observed in Meniere's disease. By using whole exome sequencing and combining bioinformatics tools, novel variants in DTNA and FAM136A genes have been identified in familial Meniere's disease, and this genomic strategy will facilitate the discovery of the genetic basis of familial vestibular disorders. PMID:27083884

  12. Unilateral Vestibular Loss Impairs External Space Representation

    PubMed Central

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

    2014-01-01

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

  13. Top-down approach to vestibular compensation: translational lessons from vestibular rehabilitation

    PubMed Central

    Balaban, Carey D.; Hoffer, Michael E.; Gottshall, Kim R.

    2012-01-01

    This review examines vestibular compensation and vestibular rehabilitation from a unified translational research perspective. Laboratory studies illustrate neurobiological principles of vestibular compensation at the molecular, cellular and systems levels in animal models that inform vestibular rehabilitation practice. However, basic research has been hampered by an emphasis on ‘naturalistic’ recovery, with time after insult and drug interventions as primary dependent variables. The vestibular rehabilitation literature, on the other hand, provides information on how the degree of compensation can be shaped by specific activity regimens. The milestones of the early spontaneous static compensation mark the re-establishment of static gaze stability, which provides a common coordinate frame for the brain to interpret residual vestibular information in the context of visual, somatosensory and visceral signals that convey gravitoinertial information. Stabilization of the head orientation and the eye orientation (suppression of spontaneous nystagmus) appear to be necessary by not sufficient conditions for successful rehabilitation, and define a baseline for initiating retraining. The lessons from vestibular rehabilitation in animal models offer the possibility of shaping the recovery trajectory to identify molecular and genetic factors that can improve vestibular compensation. PMID:22981400

  14. Neurotology symptoms at referral to vestibular evaluation

    PubMed Central

    2013-01-01

    Background Dizziness-vertigo is common in adults, but clinical providers may rarely diagnose vestibular impairment and referral could be delayed. To assess neurotology symptoms (including triggers) reported by patients with peripheral vestibular disease, during the year just before their referral to vestibular evaluation. Methods 282 patients with peripheral vestibular disease and 282 control subjects accepted to participate. They had no middle ear, retinal, neurological, psychiatric, autoimmune or autonomic disorders. They reported their symptoms by a standardized questionnaire along with their anxiety/depression symptoms. Results Patients were referred after months or years from the onset of their symptoms, 24% of them reported frequent falls with a long clinical evolution; 10% of them reported no vertigo but instability related to specific triggers; 86% patients and 12% control subjects reported instability when moving the head rapidly and 79% patients and 6% control subjects reported instability when changing posture. Seven out of the 9 symptoms explored by the questionnaire allowed the correct classification of circa 95% of the participants (Discriminant function analysis, p < 0.001). High blood pressure, dyslipidemia and anxiety/depression symptoms showed a mild correlation with the total score of symptoms (multiple R2 =0.18, p < 0.001). Conclusions Late referral to vestibular evaluation may underlie a history of frequent falls; some patients may not report vertigo, but instability related to specific triggers, which could be useful to prompt vestibular evaluation. High blood pressure, dyslipidemia and anxiety/depression symptoms may have a mild influence on the report of symptoms of vestibular disease in both, patients and control subjects. PMID:24279682

  15. Cutaneous larva migrans, sacroileitis, and optic neuritis caused by an unidentified organism acquired in Thailand.

    PubMed

    Potasman, I; Feiner, M; Arad, E; Friedman, Z

    1998-12-01

    We report the case of a 32-year-old pregnant woman with an unidentified intraocular parasite. The parasite, which had been acquired in Thailand, caused cutaneous larva migrans, sacroileitis, and 2 years later optic neuritis and panuveitis. The patient was successfully treated with ivermectin and albendazole. The diagnostic possibilities of this peculiar presentation are discussed. Parasitic infections are a leading cause of medical problems in travelers to tropical countries.1 While most parasites cause gastrointestinal problems, some may migrate throughout the body and lodge in critical organs. Ocular parasitic infections may occur by direct inoculation onto the eye,2 or incidentally during systemic migration. Subconjunctival parasites are easily diagnosed by removal and careful microscopic examination.3 Parasites, which lodge within the eye, are more difficult to diagnose, especially if not removed. In this report we describe a patient who presented with an intraocular parasite causing optic neuritis and panuveitis, 2 years after travel to Thailand. PMID:9876201

  16. Computational Approaches to Vestibular Research

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  17. Auditory and Vestibular Issues Related to Human Spaceflight

    NASA Technical Reports Server (NTRS)

    Danielson, Richard W.; Wood, Scott J.

    2009-01-01

    Human spaceflight provides unique opportunities to study human vestibular and auditory systems. This session will discuss 1) vestibular adaptive processes reflected by pronounced perceptual and motor coordination problems during, and after, space missions; 2) vestibular diagnostic and rehabilitative techniques (used to promote recovery after living in altered gravity environments) that may be relevant to treatment of vestibular disorders on earth; and 3) unique acoustical challenges to hearing loss prevention and crew performance during spaceflight missions.

  18. Noninvasive Assessments of Optic Nerve Neurodegeneration in Transgenic Mice With Isolated Optic Neuritis

    PubMed Central

    Talla, Venu; Yang, Cui; Shaw, Gerry; Porciatti, Vittorio; Koilkonda, Rajeshwari D.; Guy, John

    2013-01-01

    Purpose. To determine if phosphorylated neurofilament heavy chain (pNF-H) released into the bloodstream and the pattern ERG are noninvasive indicators of neurodegeneration in experimental optic neuritis. Methods. Serum from Myelin oligodendrocyte glycoprotein (MOG)-specific T cell receptor–positive (TCR+) transgenic mice that develop isolated optic neuritis usually without any other characteristic lesions of inflammation or demyelination in the spinal cord and littermates negative for the transgene were assayed for the presence of serum phosphorylated neurofilament H (pNF-H). In vivo measurements of optic nerve and retinal ganglion cell injury were assessed by magnetic resonance imaging (MRI), optical coherence tomography (OCT), and pattern electroretinogram (PERG). Automated two dimensional fluorescence differential in-gel electrophoresis (2D-DIGE) of pooled optic nerve samples, light, and transmission electron micrographs were used to evaluate optic atrophy postmortem. Results. We found an almost 3-fold elevation in serum pNF-H levels in MOG+ mice relative to MOG-littermates (P = 0.02). 2D-DIGE revealed a 3-fold reduction in optic nerve neurofilaments. Visual function assessed by the PERG was reduced by one-quarter (P = 0.033) and latencies increased by 38% (P = 0.036). MOG+ mice with the lowest PERG amplitudes had optic nerve atrophy visualized by MRI. Optic nerve diameters were reduced by one-third (P = 0.0001) and axon counts reduced by more than two-thirds. Histopathology of the spinal cords was normal. Conclusions. Elevated serum pNF-H levels and the PERG are useful markers of neurodegeneration of the optic nerve in isolated experimental optic neuritis. Our findings suggest that elevations of this axonal protein in patients with optic neuritis who had a poor visual outcome are likely also due to demise of optic nerve axons. PMID:23722393

  19. Unusual association of epidemic dropsy with brachial neuritis and palatal palsy.

    PubMed

    Sahoo, Sushama; Bandyopadhyay, Arindam; Mahapatra, Nepal Chandra

    2013-05-01

    Epidemic dropsy (ED) results from accidental ingestion of adulterated mustard oil with argemone oil. Chief organs involved in this disease are heart, subcutaneous tissue, eyes and kidneys. Nervous system involvement is very rare. Objective manifestation of neurological involvement is even rarer. The authors report two cases from the same family, who were victims of epidemic dropsy along with their parents. One of them showed objective neurologic involvement in the form of brachial neuritis and another showed palatal palsy. PMID:22231775

  20. [Is the sense of verticality vestibular?].

    PubMed

    Barra, J; Pérennou, D

    2013-06-01

    The vestibular system constitutes an inertial sensor, which detects linear (otoliths) and angular (semicircular canals) accelerations of the head in the three dimensions. The otoliths are specialized in the detection of linear accelerations and can be used by the brain as a "plumb line" coding earth gravity acceleration (direction). This property of otolithic system suggested that the sense of verticality is supported by the vestibular system. The preeminence of vestibular involvement in the sense of verticality stated in the 1900s was progressively supplanted by the notion of internal models of verticality. The internal models of verticality involve rules and properties of integration of vestibular graviception, somaesthesic graviception, and vision. The construction of a mental representation of verticality was mainly modeled as a bottom-up organization integrating visual, somatosensory and vestibular information without any cognitive modulations. Recent studies reported that the construction of internal models of verticality is not an automatic multi-sensory integration process but corresponds to more complex mechanisms including top-down influences such as awareness of body orientation or spatial representations. PMID:23856176

  1. Complications of Microsurgery of Vestibular Schwannoma

    PubMed Central

    Zvěřina, Eduard; Balogová, Zuzana; Skřivan, Jiří; Kraus, Josef; Syka, Josef; Chovanec, Martin

    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, grade 3: 62, and grade 4: 225) removal was performed. The main neurological complication was facial nerve dysfunction. The intermediate and poor function (HB III–VI) was observed in 124 cases (45%) immediately after surgery and in 104 cases (33%) on the last followup. We encountered disordered vestibular compensation in 13%, permanent trigeminal nerve dysfunction in 1%, and transient lower cranial nerves (IX–XI) deficit in 6%. Nonneurological complications included CSF leakage in 63% (lateral/medial variant: 99/1%), headache in 9%, and intracerebral hemorrhage in 5%. We did not encounter any case of meningitis. Conclusions. Our study demonstrates that despite the benefits of advanced high-tech equipment, refined microsurgical instruments, and highly developed neuroimaging technologies, there are still various and significant complications associated with vestibular schwannomas microsurgery. PMID:24987677

  2. Sensorial countermeasures for vestibular spatial disorientation.

    PubMed

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

    2014-05-01

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

  3. Longitudinal performance of an implantable vestibular prosthesis

    PubMed Central

    Phillips, Christopher; Ling, Leo; Oxford, Trey; Nowack, Amy; Nie, Kaibao; Rubinstein, Jay T.; Phillips, James O.

    2014-01-01

    Loss of vestibular function may be treatable with an implantable vestibular prosthesis that stimulates semicircular canal afferents with biphasic pulse trains. Several studies have demonstrated short-term activation of the vestibulo-ocular reflex (VOR) with electrical stimulation. Fewer long-term studies have been restricted to small numbers of animals and stimulation designed to produce adaptive changes in the electrically elicited response. This study is the first large consecutive series of implanted rhesus macaque to be studied longitudinally using brief stimuli designed to limit adaptive changes in response, so that the efficacy of electrical activation can be studied over time, across surgeries, canals and animals. The implantation of a vestibular prosthesis in animals with intact vestibular end organs produces variable responses to electrical stimulation across canals and animals, which change in threshold for electrical activation of eye movements and in elicited slow phase velocities over time. These thresholds are consistently lower, and the slow phase velocities higher, than those obtained in human subjects. The changes do not appear to be correlated with changes in electrode impedance. The variability in response suggests that empirically derived transfer functions may be required to optimize the response of individual canals to a vestibular prosthesis, and that this function may need to be remapped over time. PMID:25245586

  4. Thymic epithelium determines a spontaneous chronic neuritis in Icam1(tm1Jcgr)NOD mice.

    PubMed

    Meyer zu Horste, Gerd; Mausberg, Anne K; Cordes, Steffen; El-Haddad, Houda; Partke, Hans-Joachim; Leussink, Verena I; Roden, Michael; Martin, Stephan; Steinman, Lawrence; Hartung, Hans-Peter; Kieseier, Bernd C

    2014-09-15

    The NOD mouse strain spontaneously develops autoimmune diabetes. A deficiency in costimulatory molecules, such as B7-2, on the NOD genetic background prevents diabetes but instead triggers an inflammatory peripheral neuropathy. This constitutes a shift in the target of autoimmunity, but the underlying mechanism remains unknown. In this study, we demonstrate that NOD mice deficient for isoforms of ICAM-1, which comediate costimulatory functions, spontaneously develop a chronic autoimmune peripheral neuritis instead of diabetes. The disease is transferred by CD4(+) T cells, which infiltrate peripheral nerves together with macrophages and B cells and are autoreactive against peripheral myelin protein zero. These Icam1(tm1Jcgr)NOD mice exhibit unaltered numbers of regulatory T cells, but increased IL-17-producing T cells, which determine the severity, but not the target specificity, of autoimmunity. Ab-mediated ICAM-1 blockade triggers neuritis only in young NOD mice. Thymic epithelium from Icam1(tm1Jcgr)NOD mice features an altered expression of costimulatory molecules and induces neuritis and myelin autoreactivity after transplantation into nude mice in vivo. Icam1(tm1Jcgr)NOD mice exhibit a specifically altered TCR repertoire. Our findings introduce a novel animal model of chronic inflammatory neuropathies and indicate that altered expression of ICAM-1 on thymic epithelium shifts autoimmunity specifically toward peripheral nerves. This improves our understanding of autoimmunity in the peripheral nervous system with potential relevance for human diseases. PMID:25108020

  5. Brimonidine suppresses loss of retinal neurons and visual function in a murine model of optic neuritis.

    PubMed

    Guo, Xiaoli; Namekata, Kazuhiko; Kimura, Atsuko; Noro, Takahiko; Azuchi, Yuriko; Semba, Kentaro; Harada, Chikako; Yoshida, Hiroshi; Mitamura, Yoshinori; Harada, Takayuki

    2015-04-10

    Optic neuritis is inflammation of the optic nerve and is strongly associated with multiple sclerosis (MS), an inflammatory demyelinating syndrome of the central nervous system. It leads to retinal ganglion cell (RGC) death and can cause severe vision loss. Brimonidine (BMD) is a selective α2-adrenergic receptor agonist that is used clinically for the treatment of glaucoma. BMD lowers intraocular pressure, but recent evidence suggests that its therapeutic efficacy may also mediate through mechanisms independent of modulation of intraocular pressure. In this study, we examined the effects of topical administration of BMD on retinal degeneration during optic neuritis in experimental autoimmune encephalomyelitis (EAE), an animal model of MS. EAE was induced with MOG35-55 in C57BL/6J mice and BMD eyedrops were applied daily. In the EAE retina, the number of RGCs was significantly decreased and this effect was suppressed with BMD treatment. Consistent with histological analyses, the visual impairment observed in EAE mice was inhibited with BMD treatment, indicating the functional significance of the neuroprotective effect of BMD. Furthermore, BMD increased the expression level of basic fibroblast growth factor in the EAE retina, particularly in Müller glial cells and RGCs. Our findings suggest that topical administration of BMD may be available for RGC protection during optic neuritis, as well as for glaucoma. PMID:25736951

  6. Spontaneous shrinkage of vestibular schwannoma

    PubMed Central

    Romani, Rossana; Pollock, Jonathan

    2016-01-01

    Background: “Watch, wait, and rescan” (WWR) has an established place as a successful management option for a significant proportion of vestibular schwannomas (VS) as an alternative to microsurgical removal or stereotactic radiotherapy. VS may grow slowly and continuously, followed by stagnation or even shrinkage. We present two case reports of spontaneous shrinkage of VS along with a review of the literature. Case Description: A 29-year-old female presented with a progressive history of visual blurring and intermittent diplopia over 2 months. A 29 mm of maximum intracranial diameter (ICD) VS with secondary obstructive hydrocephalus was diagnosed. The patient underwent a ventriculo-peritoneal shunt with resolution of her symptoms and opted for initial WWR management. Interval scanning between 2007 and 2014 showed progressive reduction in the maximum ICD together with reduction in the degree of central tumor enhancement. Maximum ICD at most recent follow up was 22 mm. A 28-year-old female was referred with right sensorineural deafness. A right VS of maximum ICD of 27 mm was diagnosed. Initial WWR management was planned after discussion. Serial imaging showed an initial increase in the size of the tumor followed by progressive reduction in size. The most recent follow up showed a maximum ICD of 20 mm. Conclusion: Early WWR management can be associated with spontaneous shrinkage of VS over time. Prospective clinical study of larger numbers of such cases using the UK VS database may help to identify predictive factors for the spontaneous regression of VS. PMID:27280055

  7. Optical nerve stimulation for a vestibular prosthesis

    NASA Astrophysics Data System (ADS)

    Harris, David M.; Bierer, Steven M.; Wells, Jonathon D.; Phillips, James O.

    2009-02-01

    Infrared Nerve Stimulation (INS) offers several advantages over electrical stimulation, including more precise spatial selectivity and improved surgical access. In this study, INS and electrical stimulation were compared in their ability to activate the vestibular branch of the VIIIth nerve, as a potential way to treat balance disorders. The superior and lateral canals of the vestibular system of Guinea pigs were identified and approached with the aid of precise 3-D reconstructions. A monopolar platinum stimulating electrode was positioned near the ampullae of the canals, and biphasic current pulses were used to stimulate vestibular evoked potentials and eye movements. Thresholds and input/output functions were measured for various stimulus conditions. A short pulsed diode laser (Capella, Lockheed Martin-Aculight, Inc., Bothell WA) was placed in the same anatomical position and various stimulus conditions were evaluated in their ability to evoke similar potentials and eye movements.

  8. Labyrinthitis

    MedlinePlus

    Bacterial labyrinthitis; Serous labyrinthitis; Neuronitis - vestibular; Vestibular neuronitis; Viral neurolabyrinthitis; Vestibular neuritis; Labyrinthitis - vertigo: Labyrinthitis - dizziness; Labyrinthitis - vertigo; Labyrinthitis - hearing loss

  9. A systems concept of the vestibular organs

    NASA Technical Reports Server (NTRS)

    Mayne, R.

    1974-01-01

    A comprehensive model of vestibular organ function is presented. The model is based on an analogy with the inertial guidance systems used in navigation. Three distinct operations are investigated: angular motion sensing, linear motion sensing, and computation. These operations correspond to the semicircular canals, the otoliths, and central processing respectively. It is especially important for both an inertial guidance system and the vestibular organs to distinguish between attitude with respect to the vertical on the one hand, and linear velocity and displacement on the other. The model is applied to various experimental situations and found to be corroborated by them.

  10. Ocular vestibular evoked myogenic potentials in patients with acoustic neuroma.

    PubMed

    Piras, Gianluca; Brandolini, Cristina; Castellucci, Andrea; Modugno, Giovanni Carlo

    2013-02-01

    To assess the usefulness of vestibular testing in patients with acoustic neuroma, considering two main aspects: to compare diagnostic sensitivity of the current vestibular tests, especially considering ocular vestibular evoked myogenic potentials (OVEMPs) and to identify pre-operative localization of the tumor (inferior vestibular nerve vs. superior vestibular nerve) only with the help of vestibular electrophysiological data. Twenty-six patients with unilateral acoustic neuroma (mainly intracanalicular type) were studied with a full audio-vestibular test battery (pure tone and speech audiometry, caloric bithermal test, vibration-induced nystagmus test (VIN), cervical and OVEMPs). 18 patients (69 %) showed abnormal caloric responses. 12 patients (46.2 %) showed a pattern of VIN test suggestive of vestibular asymmetry. 16 patients (61.5 %) showed abnormal OVEMPs (12 only to AC, 4 both to AC and BC). 10 patients (38.5 %) showed abnormal cervical vestibular evoked myogenic potentials (5 both to AC and BC, 5 only to AC). In one case, results of vestibular evoked potentials and caloric test were confirmed by intra-operative and post-operative findings. Results of electrophysiological tests in AN patients could be helpful for planning the proper surgical approach, considering that sensitivity of every exam is quite low in intracanalicular lesion; clinical data allow a better interpretation of vestibular evoked myogenic potentials. PMID:22526579

  11. From ear to uncertainty: vestibular contributions to cognitive function

    PubMed Central

    Smith, Paul F.; Zheng, Yiwen

    2013-01-01

    In addition to the deficits in the vestibulo-ocular and vestibulo-spinal reflexes that occur following vestibular dysfunction, there is substantial evidence that vestibular loss also causes cognitive disorders, some of which may be due to the reflexive deficits and some of which are related to the role that ascending vestibular pathways to the limbic system and neocortex play in spatial orientation. In this review we summarize the evidence that vestibular loss causes cognitive disorders, especially spatial memory deficits, in animals and humans and critically evaluate the evidence that these deficits are not due to hearing loss, problems with motor control, oscillopsia or anxiety and depression. We review the evidence that vestibular lesions affect head direction and place cells as well as the emerging evidence that artificial activation of the vestibular system, using galvanic vestibular stimulation (GVS), can modulate cognitive function. PMID:24324413

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

    PubMed

    Barbosa, Felipe; Villa, Thaís Rodrigues

    2016-05-01

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

  13. Physiological principles of vestibular function on earth and in space

    NASA Technical Reports Server (NTRS)

    Minor, L. B.

    1998-01-01

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

  14. From ear to uncertainty: vestibular contributions to cognitive function.

    PubMed

    Smith, Paul F; Zheng, Yiwen

    2013-01-01

    In addition to the deficits in the vestibulo-ocular and vestibulo-spinal reflexes that occur following vestibular dysfunction, there is substantial evidence that vestibular loss also causes cognitive disorders, some of which may be due to the reflexive deficits and some of which are related to the role that ascending vestibular pathways to the limbic system and neocortex play in spatial orientation. In this review we summarize the evidence that vestibular loss causes cognitive disorders, especially spatial memory deficits, in animals and humans and critically evaluate the evidence that these deficits are not due to hearing loss, problems with motor control, oscillopsia or anxiety and depression. We review the evidence that vestibular lesions affect head direction and place cells as well as the emerging evidence that artificial activation of the vestibular system, using galvanic vestibular stimulation (GVS), can modulate cognitive function. PMID:24324413

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

    NASA Technical Reports Server (NTRS)

    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

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

    PubMed

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

    2016-02-01

    Implanted vestibular neurostimulators are effective in driving slow phase eye movements in monkeys and humans. Furthermore, increases in slow phase velocity and electrically evoked compound action potential (vECAP) amplitudes occur with increasing current amplitude of electrical stimulation. In intact monkeys, protracted intermittent stimulation continues to produce robust behavioral responses and preserved vECAPs. In lesioned monkeys, shorter duration studies show preserved but with somewhat lower or higher velocity behavioral responses. It has been proposed that such changes are due to central adaptive changes in the electrically elicited vestibulo-ocular reflex (VOR). It is equally possible that these differences are due to changes in the vestibular periphery in response to activation of the vestibular efferent system. In order to investigate the site of adaptive change in response to electrical stimulation, we performed transtympanic gentamicin perfusions to induce rapid changes in vestibular input in monkeys with long-standing stably functioning vestibular neurostimulators, disambiguating the effects of implantation from the effects of ototoxic lesion. Gentamicin injection was effective in producing a large reduction in natural VOR only when it was performed in the non-implanted ear, suggesting that the implanted ear contributed little to the natural rotational response before injection. Injection of the implanted ear produced a reduction in the vECAP responses in that ear, suggesting that the intact hair cells in the non-functional ipsilateral ear were successfully lesioned by gentamicin, reducing the efficacy of stimulation in that ear. Despite this, injection of both ears produced central plastic changes that resulted in a dramatically increased slow phase velocity nystagmus elicited by electrical stimulation. These results suggest that loss of vestibular afferent activity, and a concurrent loss of electrically elicited vestibular input, produces an

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

    PubMed Central

    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

  18. Perspectives in vestibular diagnostics and therapy

    PubMed Central

    Ernst, Arneborg

    2012-01-01

    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. PMID:22558055

  19. Response to Vestibular Sensory Events in Autism

    ERIC Educational Resources Information Center

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

    2007-01-01

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

  20. Vesibulotoxicity and Management of Vestibular Disorders

    ERIC Educational Resources Information Center

    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…

  1. Vestibular stimulation leads to distinct hemodynamic patterning

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

    Previous studies demonstrated that responses of a particular sympathetic nerve to vestibular stimulation depend on the type of tissue the nerve innervates as well as its anatomic location. In the present study, we sought to determine whether such precise patterning of vestibulosympathetic reflexes could lead to specific hemodynamic alterations in response to vestibular afferent activation. We simultaneously measured changes in systemic blood pressure and blood flow (with the use of Doppler flowmetry) to the hindlimb (femoral artery), forelimb (brachial artery), and kidney (renal artery) in chloralose-urethane-anesthetized, baroreceptor-denervated cats. Electrical vestibular stimulation led to depressor responses, 8 +/- 2 mmHg (mean +/- SE) in magnitude, that were accompanied by decreases in femoral vasoconstriction (23 +/- 4% decrease in vascular resistance or 36 +/- 7% increase in vascular conductance) and increases in brachial vascular tone (resistance increase of 10 +/- 6% and conductance decrease of 11 +/- 4%). Relatively small changes (<5%) in renal vascular tone were observed. In contrast, electrical stimulation of muscle and cutaneous afferents produced pressor responses (20 +/- 6 mmHg) that were accompanied by vasoconstriction in all three beds. These data suggest that vestibular inputs lead to a complex pattern of cardiovascular changes that is distinct from that which occurs in response to activation of other types of somatic afferents.

  2. Widespread vestibular activation of the rodent cortex.

    PubMed

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

    2015-04-15

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

  3. Immunological Influences on the Vestibular System

    NASA Technical Reports Server (NTRS)

    Warchol, Mark E.

    2003-01-01

    The goals of this project were to examine the influence of immune signaling molecules on the survival and replacement of sensory hair cells in the vestibular organs. We have made considerable progress toward that goal, particularly in the characterization of mechanisms that underlie hair cell death.

  4. Compensatory saccades benefit from prediction during head impulse testing in early recovery from vestibular deafferentation.

    PubMed

    Mantokoudis, Georgios; Agrawal, Yuri; Newman-Toker, David E; Xie, Li; Saber Tehrani, Ali S; Wong, Aaron; Schubert, Michael C

    2016-06-01

    The head impulse test (HIT) can identify a deficient vestibulo-ocular reflex (VOR) by the compensatory saccade (CS) generated once the head stops moving. The inward HIT is considered safer than the outward HIT, yet might have an oculomotor advantage given that the subject would presumably know the direction of head rotation. Here, we compare CS latencies following inward (presumed predictable) and outward (more unpredictable) HITs after acute unilateral vestibular nerve deafferentation. Seven patients received inward and outward HITs delivered at six consecutive postoperative days (POD) and again at POD 30. All head impulses were recorded by portable video-oculography. CS included those occurring during (covert) or after (overt) head rotation. Inward HITs included mean CS latencies (183.48 ms ± 4.47 SE) that were consistently shorter than those generated during outward HITs in the first 6 POD (p = 0.0033). Inward HITs induced more covert saccades compared to outward HITs, acutely. However, by POD 30 there were no longer any differences in latencies or proportions of CS and direction of head rotation. Patients with acute unilateral vestibular loss likely use predictive cues of head direction to elicit early CS to keep the image centered on the fovea. In acute vestibular hypofunction, inwardly applied HITs may risk a preponderance of covert saccades, yet this difference largely disappears within 30 days. Advantages of inwardly applied HITs are discussed and must be balanced against the risk of a false-negative HIT interpretation. PMID:26088345

  5. A reassessment of the risk of multiple sclerosis developing in patients with optic neuritis after extended follow-up.

    PubMed Central

    Francis, D A; Compston, D A; Batchelor, J R; McDonald, W I

    1987-01-01

    One hundred and one of 146 patients presenting with isolated idiopathic optic neuritis, previously reviewed in 1978, were reassessed clinically, and retyped for HLA antigens and Factor B alleles, after a mean follow-up of 11.6 years. Fifty eight patients (57%) had developed multiple sclerosis at the time of reassessment in the present study, of whom 51 (88%) had clinically definite disease. This compared with 40% of the original group, in 1978, of whom 62% then had clinically definite multiple sclerosis. When the life-table method of analysis was used, the probability of developing multiple sclerosis was 75%, 15 years after the initial episode of optic neuritis. The frequencies of HLA-DR2 and the recently defined D-region antigen, DQw1, were significantly increased in patients with isolated optic neuritis and those who subsequently developed multiple sclerosis compared with normal controls, but neither allele appears to influence progression from optic neuritis to multiple sclerosis. Patients with optic neuritis who were HLA-DR3 positive had an increased risk for the development of multiple sclerosis (RR = 2.8) and this risk was further enhanced when DR3 occurred in combination with DR2 (RR = 6.7). The overall increased risk of developing multiple sclerosis for patients with this combination was 26 times that for the normal population. When the patients' original tissue-typing was considered BT 101 no longer influenced conversion of optic neuritis to multiple sclerosis. This may partly be explained by improved methods of tissue-typing, since not all BT 101 patients were subsequently found to be positive for HLA-DR2 or HLA-DQw1 and vice versa and by extended follow-up as multiple sclerosis conversion in HLA-DR2 negative individuals increased with time. All 101 patients were typed for Factor B alleles. No significant differences in frequencies were found between individuals with isolated optic neuritis or those who progressed to multiple sclerosis compared with the

  6. Exhibition of Stochastic Resonance in Vestibular Perception

    NASA Technical Reports Server (NTRS)

    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

  7. [Demyelinating diseases in children with acute neurological symptoms].

    PubMed

    Olofsson, Isa Amalie; Skov, Liselotte; Miranda, Maria Jose

    2015-12-01

    Demyelinating diseases in children is a broad group of illnesses, which affect the central nervous system. Demyelinating diseases can be monophasic or chronic and comprise acute disseminated encephalomyelitis, optic neuritis, transverse myelitis, multiple sclerosis and neuromyelitis optica. Demyelinating diseases are rare, but it is important for the physician to recognize these diseases, as well as to understand the differential diagnoses. This review summarizes the current knowledge of demyelinating disorders in children, focusing on an approach to diagnosis and management. PMID:26651911

  8. Vagal responses to vestibular stimulation in the cat.

    PubMed

    Molinari, G A

    1975-01-01

    The effects of vestibular stimuli on the vagal efferent complex were examined in cats under chloralose anasthesia. The results showed that two functionally distinct groups of vagal efferent fibres are excited by vestibular stimuli. The neural complex involved in the delayed vestibulo-vagal response (latency of 15-22 msec) lies at the orbital surface of the cerebral cortex. The early response (latency of 3-5 msec) originates in the medulla oblongata. The reaction of some vagal units to vestibular polarization is quite similar to that of vestibular units and suggests that primary vestibular fibres reach the ipsilateral vagal efferent neurons. The present experiments give further evidence that the vestibular complex exerts a controlling influence on the cardiovascular system. PMID:1079335

  9. Recovery of vestibular function following hair cell destruction by streptomycin

    NASA Technical Reports Server (NTRS)

    Jones, T. A.; Nelson, R. C.

    1992-01-01

    Can the vestibular periphery of warm-blooded vertebrates recover functionally from severe sensory hair cell loss? Recent findings in birds suggest a mechanism for recovery but in fact no direct functional evidence has been reported. We produced vestibular hair cell lesions using the ototoxic agent streptomycin sulfate (600 mg/kg/day, 8 days, chicks, Gallus domesticus). Compound action potentials of the vestibular nerve were used as a direct measure of peripheral vestibular function. Vestibular thresholds, neural activation latencies and amplitudes were documented. Eight days of drug treatment elevated thresholds significantly (P < 0.001) and eliminated all but remnants of vestibular activity. Virtually complete physiological recovery occurred in all animals studied over a period of 70 days following treatment. Thresholds recovered within two weeks of drug treatment whereas the return of response morphologies including activation latencies and amplitudes required an additional 6-8 weeks.

  10. Anxiety Changes Depersonalization and Derealization Symptoms in Vestibular Patients

    PubMed Central

    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

  11. Prediction in the Vestibular Control of Arm Movements.

    PubMed

    Blouin, Jean; Bresciani, Jean-Pierre; Guillaud, Etienne; Simoneau, Martin

    2015-01-01

    The contribution of vestibular signals to motor control has been evidenced in postural, locomotor, and oculomotor studies. Here, we review studies showing that vestibular information also contributes to the control of arm movements during whole-body motion. The data reviewed suggest that vestibular information is used by the arm motor system to maintain the initial hand position or the planned hand trajectory unaltered during body motion. This requires integration of vestibular and cervical inputs to determine the trunk motion dynamics. These studies further suggest that the vestibular control of arm movement relies on rapid and efficient vestibulomotor transformations that cannot be considered automatic. We also reviewed evidence suggesting that the vestibular afferents can be used by the brain to predict and counteract body-rotation-induced torques (e.g., Coriolis) acting on the arm when reaching for a target while turning the trunk. PMID:26595953

  12. Ernst Mach on the vestibular organ 100 years ago

    NASA Technical Reports Server (NTRS)

    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.-

  13. Reversible tobramycin-induced bilateral high-frequency vestibular toxicity.

    PubMed

    Walsh, R M; Bath, A P; Bance, M L

    2000-01-01

    We report an unusual case of tobramycin-induced bilateral high-frequency vestibular toxicity with subsequent clinical and objective evidence of functional recovery. In those patients with a clinical presentation suggestive of aminoglycoside-induced bilateral vestibular toxicity (ataxia and oscillopsia) and normal low-frequency (ENG-caloric) responses, high-frequency rotation chair testing should be performed to exclude a high-frequency vestibular deficit. PMID:10810261

  14. Influence of temperature on the sound-evoked vestibular potential.

    PubMed

    Wit, H P; Dijkgraaf, E

    1985-01-01

    The sound-evoked vestibular potential, measured with gross electrodes after fenestration of a lateral semicircular canal in pigeons, is delayed with respect to the acoustic stimulus. The influence of temperature of the vestibular system on this delay can most easily be explained by assuming chemically mediated transmission to take place between vestibular hair cells and their primary afferents. The possibility of electrotonic transmission, however, cannot be excluded. PMID:3878654

  15. Estimation of Optical Stimulus Amplitude for Balance Training Using Electrical Stimulation of the Vestibular System

    NASA Technical Reports Server (NTRS)

    Goel, R.; De Dios, Y. E.; Cohen, H. S.; Bloomberg, J. J.; Mulavara, A. P.

    2016-01-01

    gravitational environments. This combination may help to significantly reduce the time to recover functional performance after long-duration spaceflight or after landing in a novel gravitational environment (e.g. Moon or Mars). Another application of using electrical stimulation of the vestibular system is in the evaluation of tests for vestibular function by simulating acute deterioration of vestibular sensory inputs.

  16. Dual gene therapy with extracellular superoxide dismutase and catalase attenuates experimental optic neuritis

    PubMed Central

    Qi, Xiaoping; Hauswirth, William W.

    2007-01-01

    Purpose To ameliorate experimental optic neuritis by combining scavenging of superoxide by germ line increases in the extracellular superoxide dismutase (ECSOD) and hydrogen peroxide by viral-mediated gene transfer of the human catalase gene. Methods The human catalase gene inserted into recombinant adeno-associated virus (rAAV) was injected into the right eyes of transgenic mice overexpressing human ECSOD and wild-type littermates. Animals were simultaneously sensitized for experimental autoimmune encephalomyelitis (EAE) and then sacrificed one month later. The effects of antioxidant genes (ECSOD and catalase) on the histologic lesions of EAE were measured by computerized analysis of myelin area, optic disc area, extent of the cellular infiltrate, cerium derived H2O2 reaction product and extravasation of serum albumin detected by immunogold. Results Combined scavenging of H2O2 and superoxide with ECSOD and catalase suppressed demyelination by 72%, 54% due to catalase, and 19% due to ECSOD. Disruption of the blood-brain barrier was reduced 63% by the combined effects of catalase and ECSOD, 35% due to catalase and 29% due to ECSOD. Conclusions Transgene modulation of antioxidant enzyme defenses against both superoxide and its metabolite H2O2 provide a substantial suppressive effect against EAE in the optic nerve that may be a new therapeutic strategy for suppression of optic neuritis and multiple sclerosis. PMID:17242675

  17. Periosteal Pedicle Flap Harvested during Vestibular Extension for Root Coverage

    PubMed Central

    Kumar, Shubham; Gupta, Krishna Kumar; Agrawal, Rahul; Srivastava, Pratima; Soni, Shalabh

    2015-01-01

    Root exposure along with inadequate vestibular depth is a common clinical finding. Treatment option includes many techniques to treat such defects for obtaining predictable root coverage. Normally, the vestibular depth is increased first followed by a second surgery for root coverage. The present case report describes a single-stage technique for vestibular extension and root coverage in a single tooth by using the Periosteal Pedicle Flap (PPF). This technique involves no donor site morbidity and allows for reflection of sufficient amount of periosteal flap tissue with its own blood supply at the surgical site, thus increasing the chances of success of root coverage with simultaneous increase in vestibular depth. PMID:26788377

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

    PubMed Central

    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 bandwidth of vestibular input on neck muscles is much broader than appendicular muscles (up to a factor of 3). This result challenges the notion that vestibular reflexes only contribute to postural control across the behavioral and physiological frequency range of the vestibular organ (i.e., 0–20 Hz). In this review, we explore and integrate these task-, muscle- and frequency-related differences in the vestibular system’s contribution to posture, and propose that the human nervous system has adapted vestibular signals to match the mechanical properties of the system that each group of muscles controls. PMID:25620919

  19. What is the minimal vestibular function required for compensation?

    NASA Technical Reports Server (NTRS)

    Black, F. O.; Wade, S. W.; Nashner, L. M.

    1996-01-01

    Living with an uncompensated, abnormal vestibular system requires oppressive modification of life style and often prevents return to work and activities of daily living. Patients with vestibular abnormalities were studied to determine the minimal residual vestibular function required to achieve compensation. Three groups of patients with (a) complete unilateral loss of vestibular function with normal horizontal canal-vestibulo-ocular (HCVOR) function in the opposite ear, (b) complete unilateral loss with abnormal HCVOR function in the opposite ear, and (c) bilateral reduction of vestibular function from aminoglycoside toxicity underwent vestibuloocular (VOR), optokinetic (OKN), visual-VOR (VVOR), and computerized dynamic posturography (CDP) tests before and after therapeutic procedures. Results suggest that a minimal VOR response amplitude must be present for compensation of VVOR function to occur. The roles of VOR and OKN phase shifts in vestibular compensation are more complicated and require further study. Compensation of vestibulospinal function does not necessarily accompany VOR or VVOR compensation. Ascending and descending vestibular compensatory mechanisms may involve different spatial sensory inputs. Results of these studies have important implications for the diagnosis and treatment of patients with vestibular disorders, including selection and monitoring of patients for therapeutic regimens such as vestibular nerve section and streptomycin therapy.

  20. The vestibular system of the owl

    NASA Technical Reports Server (NTRS)

    Money, K. E.; Correia, M. J.

    1973-01-01

    Five owls were given vestibular examinations, and two of them were sacrificed to provide serial histological sections of the temporal bones. The owls exhibited a curious variability in the postrotatory head nystagmus following abrupt deceleration; sometimes a brisk nystagnus with direction opposite to that appropriate to the stimulus would occur promptly after deceleration. It was found also that owls can exhibit a remarkable head stability during angular movement of the body about any axis passing through the skull. The vestibular apparatus in the owl is larger than in man, and a prominent crista neglecta is present. The tectorial membrane, the cupula, and the otolithic membranes of the utricle, saccule, and lagena are all attached to surfaces in addition to the surfaces hearing hair cells. These attachments are very substantial in the utricular otolithic membrane and in the cupula.

  1. Vestibular efferent neurons project to the flocculus

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

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

  2. Experiment M131. Human vestibular function

    NASA Technical Reports Server (NTRS)

    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.

  3. Vestibular activation of sympathetic nerve activity

    NASA Technical Reports Server (NTRS)

    Ray, C. A.; Carter, J. R.

    2003-01-01

    AIM: The vestibulosympathetic reflex refers to sympathetic nerve activation by the vestibular system. Animal studies indicate that the vestibular system assists in blood pressure regulation during orthostasis. Although human studies clearly demonstrate activation of muscle sympathetic nerve activity (MSNA) during engagement of the otolith organs, the role of the vestibulosympathetic reflex in maintaining blood pressure during orthostasis is not well-established. Examination of the vestibulosympathetic reflex with other cardiovascular reflexes indicates that it is a powerful and independent reflex. Ageing, which is associated with an increased risk for orthostatic hypotension, attenuates the vestibulosympathetic reflex. The attenuated reflex is associated with a reduction in arterial pressure. CONCLUSION: These findings suggest that the vestibulosympathetic reflex assists in blood pressure regulation in humans, but future studies examining this reflex in other orthostatically intolerant populations are necessary to address this hypothesis.

  4. Vestibular-ocular accommodation reflex in man

    NASA Technical Reports Server (NTRS)

    Clark, B.; Randle, R. J.; Stewart, J. D.

    1975-01-01

    Stimulation of the vestibular system by angular acceleration produces widespread sensory and motor effects. The present paper studies a motor effect which has not been reported in the literature, i.e., the influence of rotary acceleration of the body on ocular accommodation. The accommodation of 10 young men was recorded before and after a high-level deceleration to zero velocity following 30 sec of rotating. Accommodation was recorded continuously on an infrared optometer for 110 sec under two conditions: while the subjects observed a target set at the far point, and while they viewed the same target through a 0.3-mm pinhole. Stimulation by high-level rotary deceleration produced positive accommodation or a pseudomyopia under both conditions, but the positive accommodation was substantially greater and lasted much longer during fixation through the pinhole. It is hypothesized that this increase in accommodation is a result of a vestibular-ocular accommodation reflex.

  5. [VESTIBULAR FUNCTION AFTER REPEATED SPACE FLIGHTS].

    PubMed

    Naumov, I A; Kornilova, L N; Glukhikh, D O; Pavlova, A S; Khabarova, E V; Ekimovsky, G A; Vasin, A V

    2015-01-01

    Results of the vestibular function testing of 32 cosmonauts on return from repeated 125- to 215-day space flights (SF) on the International space station are presented. The cosmonauts were tested twice before flight (baseline data collection) and on days 1-2, 4-5 and 8-9 after landing. Electro- and video-oculography were used to register simultaneously eye and head movements. It was found that deadaptation following a repeated stay in long-duration SF takes statistically much shorter time. Most often, atypical vestibular disorders and changed patterns of the otolith-semicircular canal interaction are observed in cosmonauts who have made their maiden flights to microgravity. PMID:26934788

  6. What Galvanic Vestibular Stimulation Actually Activates

    PubMed Central

    Curthoys, Ian S.; MacDougall, Hamish Gavin

    2012-01-01

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

  7. Vestibular evoked myogenic potentials in Bell's palsy.

    PubMed

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

    2014-10-01

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

  8. Galvanic vestibular stimulation: a novel modulatory countermeasure for vestibular-associated movement disorders.

    PubMed

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

    2014-01-01

    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 considered 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. PMID:24637984

  9. Allometry in vestibular responses of anurans

    NASA Astrophysics Data System (ADS)

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

    1999-01-01

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

  10. Vestibular compensation and orientation during locomotion

    NASA Technical Reports Server (NTRS)

    Raphan, T.; Imai, T.; Moore, S. T.; Cohen, B.

    2001-01-01

    Body, head, and eye movements were studied in three dimensions while walking and turning to determine the role of the vestibular system in directing gaze and maintaining spatial orientation. The body, head, and eyes were represented as three-dimensional coordinate frames, and the movement of these frames was related to a trajectory frame that described the motion of the body on a terrestrial plane. The axis-angle of the body, head, and eye rotation were then compared to the axis-angle of the rotation of the gravitoinertial acceleration (GIA). We inferred the role of the vestibular system during locomotion and the contributions of the VCR and VOR by examining the interrelationship between these coordinate frames. Straight walking induced head and eye rotations in a compensatory manner to the linear accelerations, maintaining head pointing and gaze along the direction of forward motion. Turning generated a combination of compensation and orientation responses. The head leads and steers the turn while the eyes compensate to maintain stable horizontal gaze in space. Saccades shift horizontal gaze as the turn is executed. The head pitches, as during straight walking. It also rolls so that the head tends to align with the orientation of the GIA. Head orientation changes anticipate orientation changes of the GIA. Eye orientation follows the changes in GIA orientation so that the net orientation gaze is closer to the orientation of the GIA. The study indicates that the vestibular system utilizes compensatory and orienting mechanisms to stabilize spatial orientation and gaze during walking and turning.

  11. Radiotherapy for Vestibular Schwannomas: A Critical Review

    SciTech Connect

    Murphy, Erin S.; Suh, John H.

    2011-03-15

    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. Disrupting Vestibular Activity Disrupts Body Ownership.

    PubMed

    Hoover, Adria E N; Harris, Laurence R

    2015-01-01

    People are more sensitive at detecting asynchrony between a self-generated movement and visual feedback concerning that movement when the movement is viewed from a first-person perspective. We call this the 'self-advantage' and interpret it as an objective measure of self. Here we ask if disruption of the vestibular system in healthy individuals affects the self-advantage. Participants performed finger movements while viewing their hand in a first-person ('self') or third-person ('other') perspective and indicated which of two periods (one with minimum delay and the other with an added delay of 33-264 ms) was delayed. Their sensitivity to the delay was calculated from the psychometric functions obtained. During the testing, disruptive galvanic vestibular stimulation (GVS) was applied in five-minute blocks interleaved with five minutes of no stimulation for a total of 40 min. We confirmed the self-advantage under no stimulation (31 ms). In the presence of disruptive GVS this advantage disappeared and there was no longer a difference in performance between perspectives. The threshold delay for the 'other' perspective was not affected by the GVS. These results suggest that an intact vestibular signal is required to distinguish 'self' from 'other' and to maintain a sense of body ownership. PMID:26595957

  13. Audiologic and Vestibular Findings in Wolfram Syndrome

    PubMed Central

    Karzon, Roanne K.; Hullar, Timothy E.

    2014-01-01

    Context Clinical manifestations of Wolfram syndrome (WS), a rare autosomal recessive neurodegenerative disease, include diabetes mellitus (DM), optic nerve atrophy (OA), diabetes insipidus (DI) and sensorineural hearing loss (SNHL). Objective Assessment of auditory and vestibular function in WS patients using a standardized protocol. Design Prospective cohort study of 11 patients using otoscopic inspection, tympanometry, otoacoustic emissions, pure tones, speech in noise, the speech intelligibility index and rotational chair testing. Results Mean SNHL diagnosis was 7.3 years with 55% prevalence. Four patients with a Speech Intelligibility Index (SII) less than 0.75 (better ear) routinely used bilateral amplification devices. Two patients with normal hearing sensitivity exhibited abnormal speech in noise (SIN) scores. The only patient with significant vestibular dysfunction also had a distinctive low frequency component to her SNHL. Conclusions Hearing loss may occur earlier than previously suspected and comprehensive testing including speech in noise testing may reveal deficits not apparent with pure tone testing. Particular configurations of hearing loss may indicate a need for comprehensive vestibular assessment. Because SNHL can be the first symptom of WS, audiologists and otolaryngologists should be vigilant about referring patients with hearing loss for ophthalmologic examination. PMID:23698626

  14. Retinal Nerve Fibre Layer Thinning in Patients with Clinically Isolated Optic Neuritis and Early Treatment with Interferon-Beta

    PubMed Central

    Sühs, Kurt-Wolfram; Hein, Katharina; Pehlke, Jens R.; Käsmann-Kellner, Barbara; Diem, Ricarda

    2012-01-01

    Background Optic neuritis is associated with neurodegeneration leading to chronic impairment of visual functions. Objective This study investigated whether early treatment with interferon beta (IFN-β) slows retinal nerve fibre layer (RNFL) thinning in clinically isolated optic neuritis. Methods Twenty patients with optic neuritis and visual acuity decreased to ≤0.5 (decimal system) were included into this prospective, open-label, parallel group 4-month observation. After methylprednisolone pulse therapy, 10 patients received IFN-β from week 2 onwards. This group was compared to 10 patients free of any disease modifying treatment (DMT). The parameter of interest was change in RNFL thickness assessed at baseline and at weeks 4, 8, and 16. Changes in visual acuity, visual field, and visual evoked potentials (VEPs) served as additional outcome parameters. Results RNFL thinning did not differ between the groups with a mean reduction of 9.80±2.80 µm in IFN-β-treated patients (±SD) vs. 12.44±5.79 µm in patients who did not receive DMT (baseline non-affected eye minus affected eye at week 16; p = 0.67, t-test, 95% confidence interval: −15.77 to 10.48). Parameters of visual function did not show any differences between the groups either. Conclusions In isolated optic neuritis, early IFN-β treatment did not influence RNFL thinning nor had it any effect on recovery of visual functions. PMID:23272128

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

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

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

  16. 'PREHAB': Vestibular prehabilitation to ameliorate the effect of a sudden vestibular loss.

    PubMed

    Magnusson, Måns; Karlberg, Mikael; Tjernström, Fredrik

    2011-01-01

    A sudden unilateral loss or impairment of vestibular function causes vertigo, dizziness and impaired postural function. In most occasions, everyday activities supported or not by vestibular rehabilitation programs will promote compensation and the symptoms subside. As the compensatory process requires sensory input, matching performed motor activity, both motor learning of exercises and matching to sensory input are required. If there is a simultaneous cerebellar lesion found during surgery of the posterior cranial fossa, there may be a risk of a combined vestibulo-cerebellar lesion, with reduced compensatory abilities and with prolonged or sometimes permanent disability. On the other hand, a slow gradual loss of unilateral function occurring as the subject continues well everyday activities may go without any prominent symptoms. We therefore implemented a pre treatment plan before planned vestibular lesions (prehab). This was first done in subject undergoing gentamicin treatment for Meniere's disease (MD). Subjects perform vestibular exercises for 14 days before the first gentamicin installation and then continue doing so until free of symptoms. Most subjects would only experience slight dizziness while losing vestibular function. We then expanded the approach to patients with brainstem tumours requiring surgery but with remaining vestibular function to ease postoperative symptoms and reduce risk of combined cerebello-vestibular lesions. This patient group was given gentamicin installations trans-tympanically before tumour sugary and then underwent prehab. In all cases there was a caloric loss, loss of VOR evident in the head impulse tests, impaired subjective vertical and horizontal, and reduced caloric function induced by the pre-surgery gentamicin treatment. The prehab eliminated spontaneous and positional nystagmus, subjective symptoms, and postural function up before surgery and allowed for rapid postoperative recovery.The concept of 'pre

  17. Differential central projections of vestibular afferents in pigeons

    NASA Technical Reports Server (NTRS)

    Dickman, J. D.; Fang, Q.

    1996-01-01

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

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

    PubMed

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

    2015-12-15

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

  19. Optical coherence tomography is less sensitive than visual evoked potentials in optic neuritis

    PubMed Central

    Naismith, R T.; Tutlam, N T.; Xu, J; Shepherd, J B.; Klawiter, E C.; Song, S -K.; Cross, A H.

    2009-01-01

    Objectives: Determine the utility of optical coherence tomography (OCT) to detect clinical and subclinical remote optic neuritis (ON), its relationship to clinical characteristics of ON and visual function, and whether the retinal nerve fiber layer (RNFL) thickness functions as a surrogate marker of global disease severity. Methods: Cross-sectional study of 65 subjects with at least 1 clinical ON episode at least 6 months prior. Measures included clinical characteristics, visual acuity (VA), contrast sensitivity (CS), OCT, and visual evoked potentials (VEP). Results: Ninety-six clinically affected optic nerves were studied. The sensitivity of OCT RNFL after ON was 60%, decreasing further with mild onset and good recovery. VEP sensitivity was superior at 81% (p = 0.002). Subclinical ON in the unaffected eye was present in 32%. VEP identified 75% of all subclinically affected eyes, and OCT identified <20%. RNFL thickness demonstrated linear correlations with VA (r = 0.65) and CS (r = 0.72) but was unable to distinguish visual categories <20/50. RNFL was thinner with severe onset and disease recurrence but was unaffected by IV glucocorticoids. OCT measurements were not related to overall disability, ethnicity, sex, or age at onset. The greatest predictor for RNFL in the unaffected eye was the RNFL in the fellow affected eye. Conclusions: Visual evoked potentials (VEP) remains the preferred test for detecting clinical and subclinical optic neuritis. Optical coherence tomography (OCT) measures were unrelated to disability and demographic features predicting a worse prognosis in multiple sclerosis. OCT may provide complementary information to VEP in select cases, and remains a valuable research tool for studying optic nerve disease in populations. GLOSSARY ANOVA = analysis of variance; CIS = clinically isolated syndrome; CS = contrast sensitivity; EDSS = Expanded Disability Status Score; logMAR = logarithm of the minimum angle of resolution; MS = multiple sclerosis; MSSS

  20. RAD001 (everolimus) attenuates experimental autoimmune neuritis by inhibiting the mTOR pathway, elevating Akt activity and polarizing M2 macrophages.

    PubMed

    Han, Ranran; Gao, Juan; Zhai, Hui; Xiao, Jinting; Ding, Ya'nan; Hao, Junwei

    2016-06-01

    Guillain-Barre' syndrome (GBS) is an acute, postinfectious, immune-mediated, demyelinating disease of peripheral nerves and nerve roots. As a classical animal model of GBS, experimental autoimmune neuritis (EAN) has become well-accepted. Additionally, the potent immune modulation exerted by mammalian target of rapamycin (mTOR) inhibitors has been used to treat cancers and showed beneficial effects. Here we demonstrate that the mTOR inhibitor RAD001 (everolimus) protected rats from the symptoms of EAN, as shown by decreased paralysis, diminished inflammatory cell infiltration, reductions in demyelination of peripheral nerves and improved nerve conduction. Furthermore, RAD001 shifted macrophage polarization toward the protective M2 phenotype and modified the inflammatory milieu by downregulating the production of pro-inflammatory cytokines including IFN-γ and IL-17as well as upregulating the release of anti-inflammatory cytokines such as IL-4 and TGF-β. Amounts of the mTOR downstream targets p-P70S6K and p-4E-BP1 in sciatic nerves decreased, whereas the level of its upstream protein p-Akt was elevated. This demonstrated that RAD001 inhibited the mTOR pathway and encouraged the expression of p-Akt, which led to M2 macrophage polarization, thus improved the outcome of EAN in rats. Consequently, RAD001 exhibits strong potential as a therapeutic strategy for ameliorating peripheral poly-neuropathy. PMID:27063582

  1. A Computational Framework for Electrical Stimulation of Vestibular Nerve.

    PubMed

    Marianelli, Prisca; Capogrosso, Marco; Bassi Luciani, Lorenzo; Panarese, Alessandro; Micera, Silvestro

    2015-09-01

    The vestibular organs are very important to generate reflexes critical for stabilizing gaze and body posture. Vestibular diseases significantly reduce the quality of life of people who are affected by them. Some research groups have recently started developing vestibular neuroprostheses to mitigate these symptoms. However, many scientific and technological issues need to be addressed to optimise their use in clinical trials. We developed a computational model able to mimic the response of human vestibular nerves and which can be exploited for "in-silico" testing of new strategies to design implantable vestibular prostheses. First, a digital model of the vestibular system was reconstructed from anatomical data. Monopolar stimulation was delivered at different positions and distances from ampullary nerves. The electrical potential induced by the injected current was computed through finite-element methods and drove extra-cellular stimulation of fibers in the vestibular, facial, and cochlear nerves. The electrical activity of vestibular nerves and the resulting eye movements elicited by different stimulation protocols were investigated. A set of electrode configurations was analyzed in terms of selectivity at increasing injected current. Electrode position along the nerve plays a major role in producing undesired activity in other nontargeted nerves, whereas distance from the fiber does not significantly affect selectivity. Indications are provided to minimize misalignment in nonoptimal electrode locations. Eye movements elicited by the different stimulation protocols are calculated and compared to experimental values, for the purpose of model validation. PMID:25751868

  2. Vestibular influences on autonomic cardiovascular control in humans

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

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

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

    NASA Technical Reports Server (NTRS)

    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.

  4. Dynamic tilt thresholds are reduced in vestibular migraine

    PubMed Central

    Lewis, Richard F.; Priesol, Adrian J.; Nicoucar, Keyvan; Lim, Koeun; Merfeld, Daniel M.

    2013-01-01

    Vestibular symptoms caused by migraine, referred to as vestibular migraine, are a frequently diagnosed but poorly understood entity. Based on recent evidence that normal subjects generate vestibular-mediated percepts of head motion and reflexive eye movements using different mechanisms, we hypothesized that percepts of head motion may be abnormal in vestibular migraine. We therefore measured motion detection thresholds in patients with vestibular migraine, migraine patients with no history of vestibular symptoms, and normal subjects using the following paradigms: roll rotation while supine (dynamically activating the semicircular canals); quasi-static roll tilt (statically activating the otolith organs); and dynamic roll tilt (dynamically activating the canals and otoliths). Thresholds were determined while patients were asymptomatic using a staircase paradigm, whereby the peak acceleration of the motion was decreased or increased based on correct or incorrect reports of movement direction. We found a dramatic reduction in motion thresholds in vestibular migraine compared to normal and migraine subjects in the dynamic roll tilt paradigm, but normal thresholds in the roll rotation and quasi-static roll tilt paradigms. These results suggest that patients with vestibular migraine may have enhanced perceptual sensitivity (e.g. increased signal-to-noise ratio) for head motions that dynamically modulate canal and otolith inputs together. PMID:22348937

  5. Vestibular influences on autonomic cardiovascular control in humans.

    PubMed

    Biaggioni, I; Costa, F; Kaufmann, H

    1998-01-01

    There is substantial evidence that anatomical connections exist between vestibular and autonomic nuclei. Animal studies have shown functional interactions between the vestibular and autonomic systems. The nature of these interactions, however, is complex and has not been fully defined. Vestibular stimulation has been consistently found to reduce blood pressure in animals. Given the potential interaction between vestibular and autonomic pathways this finding could be explained by a reduction in sympathetic activity. However, rather than sympathetic inhibition, vestibular stimulation has consistently been shown to increase sympathetic outflow in cardiac and splanchnic vascular beds in most experimental models. Several clinical observations suggest that a link between vestibular and autonomic systems may also exist in humans. However, direct evidence for vestibular/autonomic interactions in humans is sparse. Motion sickness has been found to induce forearm vasodilation and reduce baroreflex gain, and head down neck flexion induces transient forearm and calf vasoconstriction. On the other hand, studies using optokinetic stimulation have found either very small, variable, or inconsistent changes in heart rate and blood pressure, despite substantial symptoms of motion sickness. Furthermore, caloric stimulation severe enough to produce nystagmus, dizziness, and nausea had no effect on sympathetic nerve activity measured directly with microneurography. No effect was observed on heart rate, blood pressure, or plasma norepinephrine. Several factors may explain the apparent discordance of these results, but more research is needed before we can define the potential importance of vestibular input to cardiovascular regulation and orthostatic tolerance in humans. PMID:9416587

  6. Electronystagmographic analysis of caloric test parameters in vestibular disorders.

    PubMed

    Szirmai, Agnes; Keller, Balázs

    2013-01-01

    The electronystagmographical analysis of the eye movements provoked by caloric stimulation is an important method in the evaluation and topical diagnostic procedure of several vestibular lesions. The aim of the study was to compare the electronystagmographical results of caloric response in several vestibular disorders. The patients were divided into five groups: right and left unilateral and bilateral peripheral lesions, central vestibular dysfunction, and normal vestibular function. In the normal vestibular system group the average caloric nystagmus SPV in normal vestibular system was 17.4 °/s. In the peripheral lesion groups the average slow phase velocities are decreased in the affected side, as we expected. In the compensated vestibular lesion the average ASPV of caloric nystagmus is also decreased on the unaffected side. This might be caused by the effect of the central adaptive mechanisms. According to our observations, in central dysfunctions the average caloric ASPV and the spontaneous nystagmus ASPV is increased (25.0 °/s). This suggests that in central vestibular lesions the central inhibiting mechanisms of the caloric response are impaired. Our results show that electronystagmographical analysis of spontaneous and caloric nystagmus is very important in the evaluation of dizzy patients. PMID:22298250

  7. Vestibular papillomatosis: An important differential diagnosis of vulvar papillomas.

    PubMed

    Ozkur, Ezgi; Falay, Tugba; Turgut Erdemir, Asli Vefa; Gurel, Mehmet Salih; Leblebici, Cem

    2016-01-01

    Most authors believe that vestibular papillomatosis (VP) is an anatomical variant of the vestibular mucosa. But VP is sometimes misdiagnosed as genital warts and this can lead to aggressive investigations, therapy, and anxiety in patients. We present a patient with VP. Dermoscopy and reflectance confocal microscopy (RCM) were performed to differentiate VP from other papilomatous diseases of the vulva. PMID:27136629

  8. Vestibular receptors contribute to cortical auditory evoked potentials☆

    PubMed Central

    Todd, Neil P.M.; Paillard, Aurore C.; Kluk, Karolina; Whittle, Elizabeth; Colebatch, James G.

    2014-01-01

    Acoustic sensitivity of the vestibular apparatus is well-established, but the contribution of vestibular receptors to the late auditory evoked potentials of cortical origin is unknown. Evoked potentials from 500 Hz tone pips were recorded using 70 channel EEG at several intensities below and above the vestibular acoustic threshold, as determined by vestibular evoked myogenic potentials (VEMPs). In healthy subjects both auditory mid- and long-latency auditory evoked potentials (AEPs), consisting of Na, Pa, N1 and P2 waves, were observed in the sub-threshold conditions. However, in passing through the vestibular threshold, systematic changes were observed in the morphology of the potentials and in the intensity dependence of their amplitude and latency. These changes were absent in a patient without functioning vestibular receptors. In particular, for the healthy subjects there was a fronto-central negativity, which appeared at about 42 ms, referred to as an N42, prior to the AEP N1. Source analysis of both the N42 and N1 indicated involvement of cingulate cortex, as well as bilateral superior temporal cortex. Our findings are best explained by vestibular receptors contributing to what were hitherto considered as purely auditory evoked potentials and in addition tentatively identify a new component that appears to be primarily of vestibular origin. PMID:24321822

  9. Effect of meprobamate on the vestibulosensory and vestibular somatic reaction

    NASA Technical Reports Server (NTRS)

    Khinchikashvili, N. V.

    1980-01-01

    The influence of meprobamate on the vestibular illusion of counter-rotation, movement coordination and vertical writing was investigated by a double blind trial method and placebo. The results confirm the possibility of the meprobamate application for prophylaxis and correction of vestibular disturbances.

  10. Isolated new onset 'atypical' optic neuritis in the NMO clinic: serum antibodies, prognoses and diagnoses at follow-up.

    PubMed

    Piccolo, L; Woodhall, M; Tackley, G; Juryńczyk, M; Kong, Y; Domingos, J; Gore, R; Vincent, A; Waters, P; Leite, M I; Palace, J

    2016-02-01

    Severe, recurrent or bilateral optic neuritis (ON) often falls within the neuromyelitis optica spectrum disorders (NMOSD), but the diagnosis can be particularly challenging and has important treatment implications. We report the features, course and outcomes of patients presenting with atypical ON when isolated at onset. We retrospectively analyzed 69 sequential patients referred to a single UK NMO center with isolated ON at onset. Aquaporin-4 antibody (AQP4-Ab) assessment was performed in all patients and IgG1 myelin-oligodenrocyte glycoprotein (MOG-Ab) in AQP4-Ab(neg) patients. 37 AQP4-Ab positive (AQP4-Ab(pos)) and 32 AQP4-Ab negative (AQP4-Ab(neg)) patients (8 with MOG-Ab) were identified. The AQP4-Ab(neg) group included heterogeneous diagnoses: multiple sclerosis (MS), NMO, relapsing isolated ON (RION), monophasic isolated ON and relapsing acute disseminated encephalomyelitis (ADEM)-like syndromes. Compared to AQP4-Ab(neg) patients, AQP4-Ab(pos) patients had a worse residual visual outcome from first attack (median VFSS 4 vs. 0, p = 0.010) and at last assessment (median VFSS 5 versus 2, p = 0.005). However, AQP4-Ab(neg) patients with RION also had poor visual outcome. Up to 35% of AQP4-Ab(neg) patients developed a LETM and two developed low positivity for AQP4-Ab over time. Eight AQP4-Ab(neg) patients (25%) were MOG-Ab positive, covering a range of phenotypes excluding MS; the first ON attack was often bilateral and most had relapsing disease with a poor final visual outcome [VFSS 4, range (0-6)]. In conlcusion, AQP4-Ab positivity is confirmed as a predictor of poor visual outcome but AQP4-Ab(neg) RION also had a poor visual outcome. Of those without AQP4-Ab, 25% had MOG-Ab and another 25% developed MS; thus, MOG-Ab is associated with AQP4-Ab(neg) non-MS ON. PMID:26668077

  11. Purified human C1-esterase inhibitor is safe in acute relapses of neuromyelitis optica

    PubMed Central

    Levy, Michael

    2014-01-01

    Objective: To minimize complement-mediated damage in acute relapses of neuromyelitis optica (NMO) by adding treatment with a complement inhibitor, purified C1-esterase inhibitor, to the current standard of care (high-dose glucocorticoids). Method: We conducted an open-label phase 1b safety and proof-of-concept trial in 10 patients with NMO–immunoglobulin G seropositive NMO or NMO spectrum disease (NMOSD) who presented with acute transverse myelitis and/or optic neuritis. In addition to treating with 1 g of daily IV methylprednisolone, we infused 2,000 units of C1-esterase inhibitor daily for 3 days, beginning on day 1 of hospitalization. The primary outcome measure was safety, and the secondary efficacy measure was change in Expanded Disability Status Scale (EDSS) scores. Results: Ten patients with NMO/NMOSD were enrolled, 7 of whom presented with acute transverse myelitis and 3 with acute optic neuritis. C1-esterase inhibitor proved to be safe in all 10 patients, with no serious adverse events recorded. There were no thromboembolic events or related lab abnormalities in any of the subjects. EDSS scores dropped from a median of 4.5 on admission to 4.0 on discharge and then down to 2.5 on 30-day follow-up. All but 1 patient returned to preattack EDSS or better and only 2 patients required escalation to plasmapheresis. Conclusions: C1-esterase inhibitor is a safe add-on therapy for patients with NMO/NMOSD presenting with acute transverse myelitis and optic neuritis. Preliminary evidence suggests a promising benefit with C1-esterase inhibitor in reducing neurologic damage and improving outcomes. A placebo-controlled trial is necessary to confirm these findings. Classification of evidence: This study provides Class IV evidence that for patients with NMO with acute transverse myelitis or optic neuritis, C1-esterase inhibitor is safe and improves disability. PMID:25340061

  12. Vestibular disorders following different types of head and neck trauma

    PubMed Central

    Kolev, Ognyan I.; Sergeeva, Michaela

    2016-01-01

    Summary This review focuses on the published literature on vestibular disorders following different types of head and neck trauma. Current knowledge of the different causes and underlying mechanisms of vestibular disorders, as well as the sites of organic damage, is presented. Non-organic mechanisms are also surveyed. The frequency of occurrence of vestibular symptoms, and of other accompanying subjective complaints, associated with different types of trauma is presented and related to the specific causes. Hypotheses about the pathogenesis of traumatic vestibular disorders are presented, and the knowledge derived from animal experiments is also discussed. We believe this to be a very important topic, since vestibular complaints in traumatic patients often remain undiagnosed or underestimated in clinical practice. This review article aims to suggest directions for additional research and to provide guidance to both the scientific and clinical practice communities. PMID:27358219

  13. Regeneration of hair cells in the mammalian vestibular system.

    PubMed

    Li, Wenyan; You, Dan; Chen, Yan; Chai, Renjie; Li, Huawei

    2016-06-01

    Hair cells regenerate throughout the lifetime of non-mammalian vertebrates, allowing these animals to recover from hearing and balance deficits. Such regeneration does not occur efficiently in humans and other mammals. Thus, balance deficits become permanent and is a common sensory disorder all over the world. Since Forge and Warchol discovered the limited spontaneous regeneration of vestibular hair cells after gentamicininduced damage in mature mammals, significant efforts have been exerted to trace the origin of the limited vestibular regeneration in mammals after hair cell loss. Moreover, recently many strategies have been developed to promote the hair cell regeneration and subsequent functional recovery of the vestibular system, including manipulating the Wnt, Notch and Atoh1. This article provides an overview of the recent advances in hair cell regeneration in mammalian vestibular epithelia. Furthermore, this review highlights the current limitations of hair cell regeneration and provides the possible solutions to regenerate functional hair cells and to partially restore vestibular function. PMID:27189205

  14. Anatomical and Physiological Considerations in Vestibular Dysfunction and Compensation

    PubMed Central

    Jones, Sherri M.; Jones, Timothy A.; Mills, Kristal N.; Gaines, G. Christopher

    2010-01-01

    Sensory information from the vestibular, visual, and somatosensory/proprioceptive systems are integrated in the brain in complex ways to produce a final motor output to muscle groups for maintaining gaze, head and body posture, and controlling static and dynamic balance. The balance system is complex, which can make differential diagnosis of dizziness quite challenging. On the other hand, this complex system is organized anatomically in a variety of pathways and some of these pathways have been well studied. The vestibulo-ocular reflex (VOR) is one such pathway. Understanding the anatomy and physiology of the VOR facilitates our understanding of normal and abnormal eye movements and research is advancing our understanding of the plasticity of the vestibular system. This review highlights anatomical and physiological features of the normal vestibular system, applies these concepts to explain some clinical findings in some common peripheral vestibular disorders, and discusses some of the research investigating the anatomical and physiological basis for vestibular compensation. PMID:21072129

  15. Tinnitus, Oscillopsia, and Hyperventilation-Induced Nystagmus: Vestibular Paroxysmia

    PubMed Central

    Ward, Bryan K; Gold, Daniel R

    2016-01-01

    Vestibular paroxysmia is the name given to vascular compression of the vestibulocochlear nerve. Substantial evidence has been discovered in support of vascular compression of the trigeminal nerve as the etiology for trigeminal neuralgia, and effective therapies have been targeted to address this pathophysiology. Perhaps due to the common and often vaguely-described symptoms of dizziness and tinnitus, vascular compression of the vestibulocochlear nerve as a cause of symptoms has remained controversial. Recent clinical studies, however, have better defined diagnostic criteria for vestibular paroxysmia. In this report we discuss a case of vestibular paroxysmia, highlighting some findings of the condition that also uniquely separate it from other more common vestibular disorders. Finally, we discuss current clinical management of vestibular paroxysmia. PMID:27158666

  16. Experimental autoimmune neuritis induces differential microglia activation in the rat spinal cord.

    PubMed

    Beiter, Thomas; Artelt, Matthias R; Trautmann, Katrin; Schluesener, Hermann J

    2005-03-01

    The reactive spatial and temporal activation pattern of parenchymal spinal cord microglia was analyzed in rat experimental autoimmune neuritis (EAN). We observed a differential activation of spinal cord microglial cells. A significant increase in ED1(+) microglia predominantly located in the dorsal horn grey matter of lumbar and thoracic spinal cord levels was observed on Day 12. As revealed by morphological criteria and by staining with further activation markers [allograft inflammatory factor 1 (AIF-1), EMAPII, OX6, P2X(4)R], reactive microglia did not reach a macrophage-like state of full activation. On Day 12, a significant proliferative response could be observed, affecting all spinal cord areas and including ED1(+) microglial cells and a wide range of putative progenitor cells. Thus, in rat EAN, a reactive localized and distinct microglial activation correlating with a generalized proliferative response could be observed. PMID:15710454

  17. Recurrent optic neuritis and neuromyelitis optica-IgG following first and second human papillomavirus vaccinations.

    PubMed

    Chang, Hyeyeon; Lee, Hye Lim; Yeo, Minju; Kim, Ji Seon; Shin, Dong-Ick; Lee, Sang-Soo; Lee, Sung-Hyun

    2016-05-01

    Human papillomavirus (HPV) vaccine is widely used to prevent cervical cancer caused by certain types of HPV in girls and young women. Demyelinating disorders within months following HPV innoculation have been reported, but the causal link between HPV vaccination and the onset of demyelinating disorders have not been certain. We report a case of neuromyelitis optica spectrum disorder (NMOSD) that was noteworthy because optic neuritis (ON) occurred in a very close temporal association with both the first and second HPV vaccinations, which might suggest an association between HPV vaccination and the development of NMO-IgG and recurrent ON. This emphasizes the necessity for continuing surveillance for adverse events after HPV vaccination. PMID:27046292

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

    NASA Technical Reports Server (NTRS)

    Barry, Susan R.; Mueller, S. Alyssa

    1995-01-01

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

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

    PubMed Central

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

    2008-01-01

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

  20. Brachial Neuritis With Phrenic Nerve Involvement in a Patient With a Possible Connective Tissue Disease

    PubMed Central

    Subash, Meera; Patel, Gaurav; Welker, John

    2014-01-01

    Background. Brachial neuritis (BN) is a rare inflammatory condition of peripheral nerves, usually involving the cervicobrachial plexus. These patients present with sudden onset of shoulder and arm pain that evolves into muscle weakness and atrophy.. Case Report. A 33-year-old woman presented with a 1-month history of diffuse pain in her thorax. She had no trauma or inciting incident prior to the onset of this pain and was initially treated for muscle spasms. The patient was seen in the emergency room multiple times and was treated with several courses of antibiotics for pneumonia on the basis of clinical symptoms and abnormal x-rays. The pleuritic chest pain persisted for at least 4 months, and the patient was eventually admitted for worsening pain and dyspnea. On physical examination, crackles were heard at both lung bases, and chest inspection revealed increased expansion in the upper thorax but poor expansion of the lower thorax and mild paradoxical respiration. “Sniff” test revealed no motion of the left hemidiaphragm and reduced motion on the right hemidiaphragm. Her computed tomography scan revealed bilateral atelectasis, more severe at the left base. She reported no symptoms involving her joints or skin or abdomen. Her presentation and clinical course are best explained by BN with a bilateral diaphragmatic weakness. However, she had a positive ANA, RF, anti-RNP antibody, and anti SS-A. Conclusion. Patients with BN can present with diffuse thoracic pain, pleuritic chest pain, and diaphragmatic weakness. Our patient may represent a case of connective tissue disease presenting with brachial plexus neuritis. PMID:26425609

  1. Brachial Neuritis With Phrenic Nerve Involvement in a Patient With a Possible Connective Tissue Disease.

    PubMed

    Subash, Meera; Patel, Gaurav; Welker, John; Nugent, Kenneth

    2014-01-01

    Background. Brachial neuritis (BN) is a rare inflammatory condition of peripheral nerves, usually involving the cervicobrachial plexus. These patients present with sudden onset of shoulder and arm pain that evolves into muscle weakness and atrophy.. Case Report. A 33-year-old woman presented with a 1-month history of diffuse pain in her thorax. She had no trauma or inciting incident prior to the onset of this pain and was initially treated for muscle spasms. The patient was seen in the emergency room multiple times and was treated with several courses of antibiotics for pneumonia on the basis of clinical symptoms and abnormal x-rays. The pleuritic chest pain persisted for at least 4 months, and the patient was eventually admitted for worsening pain and dyspnea. On physical examination, crackles were heard at both lung bases, and chest inspection revealed increased expansion in the upper thorax but poor expansion of the lower thorax and mild paradoxical respiration. "Sniff" test revealed no motion of the left hemidiaphragm and reduced motion on the right hemidiaphragm. Her computed tomography scan revealed bilateral atelectasis, more severe at the left base. She reported no symptoms involving her joints or skin or abdomen. Her presentation and clinical course are best explained by BN with a bilateral diaphragmatic weakness. However, she had a positive ANA, RF, anti-RNP antibody, and anti SS-A. Conclusion. Patients with BN can present with diffuse thoracic pain, pleuritic chest pain, and diaphragmatic weakness. Our patient may represent a case of connective tissue disease presenting with brachial plexus neuritis. PMID:26425609

  2. Experiment M-131 - Human vestibular function.

    NASA Technical Reports Server (NTRS)

    Miller, E. F., II; Graybiel, A.

    1973-01-01

    The purpose of the M-131 experiment is to measure responses in astronauts throughout orbital flight that reflect vestibular function and compare them with measurements made before and after flight. Three subtasks require measurement of (1) susceptibility to motion sickness, (2) thresholds of response to stimulation of the semicircular canals, and (3) space perception, viz, visual and nonvisual localization, using external spacecraft and internal morphological frames of reference. Four astronauts will be available for all measurements in Skylab 2 and 3 and two additional astronauts for only the 'static' measurements during the flights.

  3. Human Vestibular Function - Skylab Experiment M131

    NASA Technical Reports Server (NTRS)

    1972-01-01

    This set of photographs details Skylab's Human Vestibular Function experiment (M131). This experiment was a set of medical studies designed to determine the effect of long-duration space missions on astronauts' coordination abilities. This experiment tested the astronauts susceptibility to motion sickness in the Skylab environment, acquired data fundamental to an understanding of the functions of human gravity reception under prolonged absence of gravity, and tested for changes in the sensitivity of the semicircular canals. Data from this experiment was collected before, during, and after flight. The Marshall Space Flight Center had program management responsibility for the development of Skylab hardware and experiments.

  4. Altered vestibular function in fetal and newborn rats gestated in space

    NASA Technical Reports Server (NTRS)

    Ronca, A. E.; Alberts, J. R.

    1997-01-01

    Researchers evaluated vestibular development and function in rat pups flown during gestation on the NASA-NIH R1 and R2 missions. Fetal and postnatal vestibular function were examined. Altered vestibular-mediated responses in the experimental fetal pups are attributed to either direct effect of gravity on the vestibular system or indirect effects of microgravity transduced through the mother. The postnatal tests confirmed the hypothesis that the vestibular system continually adapts and responds to tonic stimulation.

  5. Vestibular rehabilitation therapy: review of indications, mechanisms, and key exercises.

    PubMed

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

    2011-12-01

    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 habituation. The key exercises for VRT are head-eye movements with various body postures and activities, and maintaining balance with a reduced support base with various orientations of the head and trunk, while performing various upper-extremity tasks, repeating the movements provoking vertigo, and exposing patients gradually to various sensory and motor environments. VRT is indicated for any stable but poorly compensated vestibular lesion, regardless of the patient's age, the cause, and symptom duration and intensity. Vestibular suppressants, visual and somatosensory deprivation, immobilization, old age, concurrent central lesions, and long recovery from symptoms, but there is no difference in the final outcome. As long as exercises are performed several times every day, even brief periods of exercise are sufficient to facilitate vestibular recovery. Here the authors review the mechanisms and the key exercises for each of the VRT goals. PMID:22259614

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

    PubMed

    Bush, Matthew L; Dougherty, William

    2015-08-01

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

  7. Biomimetic smart sensors for autonomous robotic behavior II: vestibular processing

    NASA Astrophysics Data System (ADS)

    Xue, Shuwan; Deligeorges, Socrates; Soloway, Aaron; Lichtenstein, Lee; Gore, Tyler; Hubbard, Allyn

    2009-05-01

    Limited autonomous behaviors are fast becoming a critical capability in the field of robotics as robotic applications are used in more complicated and interactive environments. As additional sensory capabilities are added to robotic platforms, sensor fusion to enhance and facilitate autonomous behavior becomes increasingly important. Using biology as a model, the equivalent of a vestibular system needs to be created in order to orient the system within its environment and allow multi-modal sensor fusion. In mammals, the vestibular system plays a central role in physiological homeostasis and sensory information integration (Fuller et al, Neuroscience 129 (2004) 461-471). At the level of the Superior Colliculus in the brain, there is multimodal sensory integration across visual, auditory, somatosensory, and vestibular inputs (Wallace et al, J Neurophysiol 80 (1998) 1006-1010), with the vestibular component contributing a strong reference frame gating input. Using a simple model for the deep layers of the Superior Colliculus, an off-the-shelf 3-axis solid state gyroscope and accelerometer was used as the equivalent representation of the vestibular system. The acceleration and rotational measurements are used to determine the relationship between a local reference frame of a robotic platform (an iRobot Packbot®) and the inertial reference frame (the outside world), with the simulated vestibular input tightly coupled with the acoustic and optical inputs. Field testing of the robotic platform using acoustics to cue optical sensors coupled through a biomimetic vestibular model for "slew to cue" gunfire detection have shown great promise.

  8. Diversity of vestibular nuclei neurons targeted by cerebellar nodulus inhibition

    PubMed Central

    Meng, Hui; Blázquez, Pablo M; Dickman, J David; Angelaki, Dora E

    2014-01-01

    Abstract A functional role of the cerebellar nodulus and ventral uvula (lobules X and IXc,d of the vermis) for vestibular processing has been strongly suggested by direct reciprocal connections with the vestibular nuclei, as well as direct vestibular afferent inputs as mossy fibres. Here we have explored the types of neurons in the macaque vestibular nuclei targeted by nodulus/ventral uvula inhibition using orthodromic identification from the caudal vermis. We found that all nodulus-target neurons are tuned to vestibular stimuli, and most are insensitive to eye movements. Such non-eye-movement neurons are thought to project to vestibulo-spinal and/or thalamo-cortical pathways. Less than 20% of nodulus-target neurons were sensitive to eye movements, suggesting that the caudal vermis can also directly influence vestibulo-ocular pathways. In general, response properties of nodulus-target neurons were diverse, spanning the whole continuum previously described in the vestibular nuclei. Most nodulus-target cells responded to both rotation and translation stimuli and only a few were selectively tuned to translation motion only. Other neurons were sensitive to net linear acceleration, similar to otolith afferents. These results demonstrate that, unlike the flocculus and ventral paraflocculus which target a particular cell group, nodulus/ventral uvula inhibition targets a large diversity of cell types in the vestibular nuclei, consistent with a broad functional significance contributing to vestibulo-ocular, vestibulo-thalamic and vestibulo-spinal pathways. PMID:24127616

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

    PubMed

    Lacour, Michel

    2013-01-01

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

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

    PubMed Central

    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 habituation. The key exercises for VRT are head-eye movements with various body postures and activities, and maintaining balance with a reduced support base with various orientations of the head and trunk, while performing various upper-extremity tasks, repeating the movements provoking vertigo, and exposing patients gradually to various sensory and motor environments. VRT is indicated for any stable but poorly compensated vestibular lesion, regardless of the patient's age, the cause, and symptom duration and intensity. Vestibular suppressants, visual and somatosensory deprivation, immobilization, old age, concurrent central lesions, and long recovery from symptoms, but there is no difference in the final outcome. As long as exercises are performed several times every day, even brief periods of exercise are sufficient to facilitate vestibular recovery. Here the authors review the mechanisms and the key exercises for each of the VRT goals. PMID:22259614

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

    PubMed Central

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

    2015-01-01

    To determine how the vestibular sense controls balance, we used instantaneous head angular velocity to drive a galvanic vestibular stimulus so that afference would signal that head movement was faster or slower than actual. In effect, this changed vestibular afferent gain. This increased sway 4-fold when subjects (N = 8) stood without vision. However, after a 240 s conditioning period with stable balance achieved through reliable visual or somatosensory cues, sway returned to normal. An equivalent galvanic stimulus unrelated to sway (not driven by head motion) was equally destabilising but in this situation the conditioning period of stable balance did not reduce sway. Reflex muscle responses evoked by an independent, higher bandwidth vestibular stimulus were initially reduced in amplitude by the galvanic stimulus but returned to normal levels after the conditioning period, contrary to predictions that they would decrease after adaptation to increased sensory gain and increase after adaptation to decreased sensory gain. We conclude that an erroneous vestibular signal of head motion during standing has profound effects on balance control. If it is unrelated to current head motion, the CNS has no immediate mechanism of ignoring the vestibular signal to reduce its influence on destabilising balance. This result is inconsistent with sensory reweighting based on disturbances. The increase in sway with increased sensory gain is also inconsistent with a simple feedback model of vestibular reflex action. Thus, we propose that recalibration of a forward sensory model best explains the reinterpretation of an altered reafferent signal of head motion during stable balance. PMID:25894558

  12. Adaptive plasticity in vestibular influences on cardiovascular control

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

  13. Galvanic vestibular stimulation speeds visual memory recall.

    PubMed

    Wilkinson, David; Nicholls, Sophie; Pattenden, Charlotte; Kilduff, Patrick; Milberg, William

    2008-08-01

    The experiments of Alessandro Volta were amongst the first to indicate that visuo-spatial function can be altered by stimulating the vestibular nerves with galvanic current. Until recently, the beneficial effects of the procedure were masked by the high levels of electrical current applied, which induced nystagmus-related gaze deviation and spatial disorientation. However, several neuropsychological studies have shown that much weaker, imperceptible currents that do not elicit unpleasant side-effects can help overcome visual loss after stroke. Here, we show that visual processing in neurologically healthy individuals can also benefit from galvanic vestibular stimulation. Participants first learnt the names of eight unfamiliar faces and then after a short delay, answered questions from memory about how pairs of these faces differed. Mean correct reaction times were significantly shorter when sub-sensory, noise-enhanced anodal stimulation was administered to the left mastoid, compared to when no stimulation was administered at all. This advantage occurred with no loss in response accuracy, and raises the possibility that the procedure may constitute a more general form of cognitive enhancement. PMID:18584162

  14. Improving Sensorimotor Function Using Stochastic Vestibular Stimulation

    NASA Technical Reports Server (NTRS)

    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

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

    NASA Technical Reports Server (NTRS)

    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.

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

    PubMed

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

    2015-03-01

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

  17. Delayed rupture of flexor tendons in zone V complicated by neuritis 18 years following Galeazzi fracture-dislocation

    PubMed Central

    Nagy, Mathias Thomas; Ghosh, Sabyasachi; Shah, Bhavik; Sankar, Thangasamy

    2014-01-01

    We report a rare case of an 84-year-old woman who presented with delayed, complete rupture of superficial (flexor digitorum superficialis) and deep flexor tendons (flexor digitorum profundus) of the third, fourth and fifth digits of the right hand in zone V of the flexor tendons. The patient, who was otherwise healthy, active and independent, incurred a closed fracture of her right wrist 18 years ago, which was treated conservatively. Current X-rays and operative findings confirmed a malunited Galeazzi fracture-dislocation with volar dislocation of the ulna from the distal radioulnar joint. She underwent surgical treatment to improve her hand function and agonising neuritis symptoms, as she was unable to use her middle, ring and little fingers and had developed severe neuritis of the ulnar nerve. Exploration and repair of the flexor tendons, nerve decompressions and Darrach procedure were performed. On follow-up, the patient showed improvement in hand function with the neuritis completely resolved. PMID:24739650

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

    PubMed Central

    Bryan, Ayanna S.; Angelaki, Dora E.

    2009-01-01

    We recorded from rostral vestibular (VN) and rostral fastigial nuclei (FN) neurons that did not respond to eye movements during three-dimensional (3D) vestibular and optokinetic stimulation (OKS). The majority of neurons in both areas (76 and 69% in VN and FN, respectively) responded during both rotational and translational motion. Preferred directions scattered throughout 3D space for translation but showed some preference for pitch/roll over yaw for rotation. VN/FN neurons were also tested during OKS while monkeys suppressed their optokinetic nystagmus by fixating a head-fixed target. Only a handful of cells (VN: 17%, FN: 6%) modulated during 0.5-Hz OKS suppression, but the number of responsive cells increased (VN: 40%, FN: 48%) during 0.02-Hz OKS. Preferred directions for rotation and OKS were not matched on individual neurons, and OKS gains were smaller than the respective gains during rotation. These results were generally similar for VN and FN neurons. We conclude that optokinetic-vestibular convergence might not be as prevalent as earlier studies have suggested. PMID:19073813

  19. Multisensory effects on somatosensation: a trimodal visuo-vestibular-tactile interaction.

    PubMed

    Kaliuzhna, Mariia; Ferrè, Elisa Raffaella; Herbelin, Bruno; Blanke, Olaf; Haggard, Patrick

    2016-01-01

    Vestibular information about self-motion is combined with other sensory signals. Previous research described both visuo-vestibular and vestibular-tactile bilateral interactions, but the simultaneous interaction between all three sensory modalities has not been explored. Here we exploit a previously reported visuo-vestibular integration to investigate multisensory effects on tactile sensitivity in humans. Tactile sensitivity was measured during passive whole body rotations alone or in conjunction with optic flow, creating either purely vestibular or visuo-vestibular sensations of self-motion. Our results demonstrate that tactile sensitivity is modulated by perceived self-motion, as provided by a combined visuo-vestibular percept, and not by the visual and vestibular cues independently. We propose a hierarchical multisensory interaction that underpins somatosensory modulation: visual and vestibular cues are first combined to produce a multisensory self-motion percept. Somatosensory processing is then enhanced according to the degree of perceived self-motion. PMID:27198907

  20. Multisensory effects on somatosensation: a trimodal visuo-vestibular-tactile interaction

    PubMed Central

    Kaliuzhna, Mariia; Ferrè, Elisa Raffaella; Herbelin, Bruno; Blanke, Olaf; Haggard, Patrick

    2016-01-01

    Vestibular information about self-motion is combined with other sensory signals. Previous research described both visuo-vestibular and vestibular-tactile bilateral interactions, but the simultaneous interaction between all three sensory modalities has not been explored. Here we exploit a previously reported visuo-vestibular integration to investigate multisensory effects on tactile sensitivity in humans. Tactile sensitivity was measured during passive whole body rotations alone or in conjunction with optic flow, creating either purely vestibular or visuo-vestibular sensations of self-motion. Our results demonstrate that tactile sensitivity is modulated by perceived self-motion, as provided by a combined visuo-vestibular percept, and not by the visual and vestibular cues independently. We propose a hierarchical multisensory interaction that underpins somatosensory modulation: visual and vestibular cues are first combined to produce a multisensory self-motion percept. Somatosensory processing is then enhanced according to the degree of perceived self-motion. PMID:27198907

  1. International guidelines for education in vestibular rehabilitation therapy.

    PubMed

    Cohen, Helen S; Gottshall, Kim R; Graziano, Mariella; Malmstrom, Eva-Maj; Sharpe, Margaret H; Whitney, Susan L

    2011-01-01

    The Barany Society Ad Hoc Committee on Vestibular Rehabilitation Therapy has developed guidelines for developing educational programs for continuing education. These guidelines may be useful to individual therapists who seek to learn about vestibular rehabilitation or who seek to improve their knowledge bases. These guidelines may also be useful to professional organizations or therapists who provide continuing education in vestibular rehabilitation. We recommend a thorough background in basic vestibular science as well as an understating of current objective diagnostic testing and diagnoses, understanding of common tests used by therapists to assess postural control, vertigo and ability to perform activities of daily living. We recommend that therapists be familiar with the evidence supporting efficacy of available treatments as well as with limitations in the current research. PMID:22101295

  2. Certain aspects of the vestibular problem in space medicine

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Vestibulovegetative disorders on manned space flights are discussed. A study relating to the vestibular stimuli in respiration, diaphoresis cardiac rhythm and a broad complex of hemodynamic indices was conducted. Certain tests for astronaut candidates are discussed.

  3. Behavioral Assessment of the Aging Mouse Vestibular System

    PubMed Central

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

    2014-01-01

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

  4. What are the Symptoms of a Vestibular Disorder?

    MedlinePlus

    ... distance Increased night blindness; difficulty walking in the dark Poor depth perception Visit the Neuro-Optometric Association's ... vestibular disorders can be. Your support of VEDA matters. Please help us continue this important work by ...

  5. Distinct spontaneous shrinkage of a sporadic vestibular schwannoma.

    PubMed

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

    2013-04-01

    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. PMID:22858145

  6. Surgical access to separate branches of the cat vestibular nerve

    NASA Technical Reports Server (NTRS)

    Radkevich, L. A.; Ayzikov, G. S.

    1981-01-01

    A posteroventral approach for access to separate branches of the cat vestibular nerve is presented which permits simultaneous surgical access to the ampullary and otolithic nerves. Surgical procedures are discussed.

  7. Bevacizumab is safe in acute relapses of neuromyelitis optica

    PubMed Central

    Mealy, Maureen A.; Shin, Kyong; John, Gareth; Levy, Michael

    2015-01-01

    Objectives Neuromyelitis optica (NMO) is a relapsing autoimmune disease targeting the spinal cord and optic nerve leading to paralysis and blindness. Current treatment for acute NMO attacks is immunosuppression with high-dose corticosteroids and/or plasmapheresis. Preclinical animal studies suggest that bevacizumab might be beneficial in limiting the extent of inflammation during a NMO relapse by reducing the disruption of the blood–brain barrier. Methods We carried out an open-label phase 1b safety and proof-of-concept trial in 10 participants with NMO immunoglobulin G seropositive NMO, NMO spectrum disease and those at high risk for developing NMO/NMO spectrum disease who presented with an acute attack of transverse myelitis, optic neuritis or brainstem inflammation. In addition to treating with 1 g of daily intravenous methylprednisolone, we infused 10 mg/kg of bevacizumab intravenously on day 1 of treatment. The primary outcome measure was safety and the secondary outcome measure was efficacy. Results Of the 10 participants enrolled, five presented with acute transverse myelitis, four with acute optic neuritis and one with a brainstem lesion. Bevacizumab was safe in all 10 participants, with only one serious adverse event within the 90-day follow up that was not attributed to the medication. Three patients recovered to pre-attack neurological function or better, and no patients required escalation to plasmapheresis. Conclusions Bevacizumab is a safe add-on therapy to high-dose corticosteroids for NMO/NMO spectrum disease patients presenting with an acute relapse. PMID:26834844

  8. Timing of neuron development in the rodent vestibular system

    NASA Technical Reports Server (NTRS)

    Keefe, J. R.

    1982-01-01

    The timing of cell generation (onset and duration) in the developing rat vestibular and proprioceptive systems is investigated. The results clearly indicate a defined time-span for generation of all neurons in the central nervous system nuclei studied. This cytogenetic period in both vestibular and proprioceptive sensory nuclei is determined to occur during and immediately after placentation, a potentially critical period for spaceflight exposure due to alterations in maternal physiology.

  9. Astronaut Newman participates in Visual-Vestibular Integration DSO

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Astronaut James H. Newman, mission specialist, participates in a Detailed Supplementary Objective (DSO) titled Visual-Vestibular Integration as a Function of Adaptation. Out of the frame is a series of equally spaced dots aligned both vertically and horizontally. The objective of this DSO is to investigate visual-vestibular and perceptual adaptive responses as a function of mission duration. Newman is wearing the DSO goggles.

  10. The European vestibular experiments in spacelab-1

    NASA Astrophysics Data System (ADS)

    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.

  11. Vestibular response in denatured rape oil intoxication.

    PubMed

    Gavilán, C; Gavilán, J; Abril, A

    1985-10-01

    During the spring of 1981 a massive intoxication broke out in Spain, which is presently attributed to the ingestion of denatured rape oil, and which has been called 'Toxic Syndrome' (TS). We studied 51 patients affected by the TS one year after the onset of their disease, analyzing their vestibular responses in the caloric test with the help of an analog-digital computer. A significant decrease in the number of nystagmic beats of the affected patients can be observed, while the rest of the parameters studied show similar values to those found simultaneously in 30 normal subjects. It is suggested that these differences are yet another manifestation of the polyneuropathy found in intoxication by denatured rape oil. PMID:3877134

  12. Effect of gravity on vestibular neural development

    NASA Technical Reports Server (NTRS)

    Ross, M. D.; Tomko, D. L.

    1998-01-01

    The timing, molecular basis, and morphophysiological and behavioral consequences of the interaction between external environment and the internal genetic pool that shapes the nervous system over a lifetime remain important questions in basic neuroscientific research. Space station offers the opportunity to study this interaction over several life cycles in a variety of organisms. This short review considers past work in altered gravity, particularly on the vestibular system, as the basis for proposing future research on space station, and discusses the equipment necessary to achieve goals. It is stressed that, in keeping with the international investment being made in this research endeavor, both the questions asked and the technologies to be developed should be bold. Advantage must be taken of this unique research environment to expand the frontiers of neuroscience. Copyright 1998 Published by Elsevier Science B.V.

  13. Vestibular ataxia and its measurement in man

    NASA Technical Reports Server (NTRS)

    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.

  14. Vestibular adaptation to space in monkeys

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

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

  15. Patterning of sympathetic nerve activity in response to vestibular stimulation

    NASA Technical Reports Server (NTRS)

    Kerman, I. A.; McAllen, R. M.; Yates, B. J.

    2000-01-01

    Growing evidence suggests a role for the vestibular system in regulation of autonomic outflow during postural adjustments. In the present paper we review evidence for the patterning of sympathetic nerve activity elicited by vestibular stimulation. In response to electrical activation of vestibular afferents, firing of sympathetic nerves located throughout the body is altered. However, activity of the renal nerve is most sensitive to vestibular inputs. In contrast, high-intensity simultaneous activation of cutaneous and muscle inputs elicits equivalent changes in firing of the renal, superior mesenteric and lumbar colonic nerves. Responses of muscle vasoconstrictor (MVC) efferents to vestibular stimulation are either inhibitory (Type I) or are comprised of a combination of excitation and inhibition (Type II). Interestingly, single MVC units located in the hindlimb exhibited predominantly Type I responses while those located in the forelimb and face exhibited Type II responses. Furthermore, brachial and femoral arterial blood flows were dissociated in response to vestibular stimulation, such that brachial vascular resistance increased while femoral resistance decreased. These studies demonstrate that vestibulosympathetic reflexes are patterned according to both the anatomical location and innervation target of a particular sympathetic nerve, and can lead to distinct changes in local blood flow.

  16. Visuo-vestibular contributions to anxiety and fear.

    PubMed

    Coelho, Carlos M; Balaban, Carey D

    2015-01-01

    The interactive roles of the visual and vestibular systems allow for postural control within boundaries of perceived safety. In specific circumstances, visual vestibular and postural interactions act as a cue that trigger fear, similarly to what occurs in motion sickness. Unusual patterns of visuo-vestibular interaction that emerge without warning can elicit fear, which can then become associated to a certain stimuli or situation, creating a CS-US association, (i.e., phobia), or can emerge without warning but also without becoming associated to a particular concomitant event (i.e., panic). Depending on the individual sensitivity to visuo-vestibular unusual patterns and its impact in postural control, individuals will be more or less vulnerable to develop these disorders. As such, the mechanism we here propose is also sufficient to explain the lack of certain fears albeit exposure. Following this rationale, a new subcategory of anxiety disorders, named visuo-vestibular fears can be considered. This model brings important implications for developmental and evolutionary psychological science, and invites to place visuo-vestibular fears in a particular subtype or specification within the DSM-5 diagnostic criteria. PMID:25451199

  17. The Moving History of Vestibular Stimulation as a Therapeutic Intervention.

    PubMed

    Grabherr, Luzia; Macauda, Gianluca; Lenggenhager, Bigna

    2015-01-01

    Although the discovery and understanding of the function of the vestibular system date back only to the 19th century, strategies that involve vestibular stimulation were used long before to calm, soothe and even cure people. While such stimulation was classically achieved with various motion devices, like Cox's chair or Hallaran's swing, the development of caloric and galvanic vestibular stimulation has opened up new possibilities in the 20th century. With the increasing knowledge and recognition of vestibular contributions to various perceptual, motor, cognitive, and emotional processes, vestibular stimulation has been suggested as a powerful and non-invasive treatment for a range of psychiatric, neurological and neurodevelopmental conditions. Yet, the therapeutic interventions were, and still are, often not hypothesis-driven as broader theories remain scarce and underlying neurophysiological mechanisms are often vague. We aim to critically review the literature on vestibular stimulation as a form of therapy in various selected disorders and present its successes, expectations, and drawbacks from a historical perspective. PMID:26595961

  18. Vestibular activity and cognitive development in children: perspectives

    PubMed Central

    Wiener-Vacher, Sylvette R.; Hamilton, Derek A.; Wiener, Sidney I.

    2013-01-01

    Vestibular signals play an essential role in oculomotor and static and dynamic posturomotor functions. Increasing attention is now focusing on their impact on spatial and non-spatial cognitive functions. Movements of the head in space evoke vestibular signals that make important contributions during the development of brain representations of body parts relative to one another as well as representations of body orientation and position within the environment. A central nervous system pathway relays signals from the vestibular nuclei to the hippocampal system where this input is indispensable for neuronal responses selective for the position and orientation of the head in space. One aspect of the hippocampal systems’ processing to create episodic and contextual memories is its role in spatial orientation and navigation behaviors that require processing of relations between background cues. These are also impaired in adult patients with vestibular deficits. However little is known about the impact of vestibular loss on cognitive development in children. This is investigated here with a particular emphasis upon the hypothetical mechanisms and potential impact of vestibular loss at critical ages on the development of respective spatial and non-spatial cognitive processes and their brain substrates. PMID:24376403

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

    NASA Technical Reports Server (NTRS)

    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.

  20. How the vestibular system interacts with somatosensory perception: a sham-controlled study with galvanic vestibular stimulation.

    PubMed

    Ferrè, Elisa R; Day, Brian L; Bottini, Gabriella; Haggard, Patrick

    2013-08-29

    The vestibular system has widespread interactions with other sensory modalities. Here we investigate whether vestibular stimulation modulates somatosensory function, by assessing the ability to detect faint tactile stimuli to the fingertips of the left and right hand with or without galvanic vestibular stimulation (GVS). We found that left anodal and right cathodal GVS, significantly enhanced sensitivity to mild shocks on either hand, without affecting response bias. There was no such effect with either right anodal and left cathodal GVS or sham stimulation. Further, the enhancement of somatosensory sensitivity following GVS does not strongly depend on the duration of GVS, or the interval between GVS and tactile stimulation. Vestibular inputs reach the somatosensory cortex, increasing the sensitivity of perceptual circuitry. PMID:23827220

  1. Vestibular system paresis due to emergency endovascular catheterization

    PubMed Central

    Simoceli, Lucinda; Sguillar, Danilo Anunciatto; Santos, Henrique Mendes Paiva; Caputti, Camilla

    2012-01-01

    Summary Objective: The objective of this story of case is to describe an uncommon cause of associated peripheral Vestibulopathy to the unilateral auditory loss in aged patient after catheterization of urgency. Story of case: Patient of the masculine sort, 82 years, submitted to the correction of abdominal ragged aneurism of aorta, in the intra-operative suffered heart attack acute from the myocardium needing primary angioplasty. High after hospital it relates to complaint of accented hearing loss to the right and crippling vertigo, without focal neurological signals. To the otorhinolaryngological clinical examination it presented: Test of Weber lateralized for the left, spontaneous nystagmus for the left, marches rocking, has taken normal disbasia and ataxia, index-nose and diadochokinesia, Test of Romberg with oscillation without fall and Fukuda with lateral shunting line for the right. The audiometric examination evidenced deafness to the right and sensorineural loss to the left in sharps, areflexia initial to the right in caloric test e, the computerized tomography of the secular bones and brainstem, presence of metallic connecting rod crossing the right secular bone, from the vein internal jugular vein and bulb jugular vein, crossing the posterior, superior and vestibule semicircular canals, projecting itself in temporal lobe. The radiological diagnoses was traumatic injury for guide to endovascular metallic during catheterization of urgency and the behavior, considering that the patient had not compensated the balance, it was vestibular rehabilitation. Conclusion: Complaints of giddiness in the aged patient must be closely evaluated of its pathological clinical description because the antecedents of illnesses and previous treatments, in general, direct the diagnostic hypotheses however they can bring unexpected alterations. PMID:25991947

  2. Analysis of Fundus Photography and Fluorescein Angiography in Nonarteritic Anterior Ischemic Optic Neuropathy and Optic Neuritis

    PubMed Central

    Kim, Min Kyung

    2016-01-01

    Purpose We evaluated fundus and fluorescein angiography (FAG) findings and characteristics that can help distinguish nonarteritic anterior ischemic optic neuropathy (NAION) from optic neuritis (ON). Methods Twenty-three NAION patients and 17 ON with disc swelling patients were enrolled in this study. We performed fundus photography and FAG. The disc-swelling pattern, hyperemia grade, presence of splinter hemorrhages, cotton-wool spots, artery/vein ratio and degree of focal telangiectasia were investigated. The FAG findings for each patient were compared with respect to the following features: the pattern of disc leakage in the early phase, arteriovenous (artery/vein) transit time (second), and the presence and pattern of the filling delay. Results Cotton-wool spots, focal telangiectasia, and venous congestion were more common in the affected eyes of NAION patients. Upon FAG, 76.5% of the patients in the ON group exhibited normal choroidal circulation. However, 56.5% of patients in the NAION group demonstrated abnormal filling defects, such as peripapillary, generalized, or watershed zone filling delays. Conclusions Fundus findings, including cotton-wool spots, focal telangiectasia, and venous congestion in the affected eye, may be clues that can be used to diagnose NAION. In addition, choroidal insufficiencies on FAG could be also helpful in differentiating NAION from ON. PMID:27478356

  3. Transforming growth factor-beta 1 in experimental autoimmune neuritis. Cellular localization and time course.

    PubMed Central

    Kiefer, R.; Funa, K.; Schweitzer, T.; Jung, S.; Bourde, O.; Toyka, K. V.; Hartung, H. P.

    1996-01-01

    Experimental autoimmune neuritis (EAN) is a monophasic inflammatory disorder of the peripheral nervous system that resolves spontaneously by molecular mechanisms as yet unknown. We have investigated whether the immunosuppressive cytokine transforming growth factor-beta 1 (TGF-beta 1) might be endogenously expressed in the peripheral nervous system of Lewis rats with actively induced and adoptive transfer EAN. TGF-beta 1 mRNA was upregulated to high levels in sensory and motor roots, spinal ganglia, and sciatic nerve as revealed by quantitative Northern blot analysis and in situ hybridization histochemistry, with peak levels just preceding the first signs of clinical recovery. TGF-beta 1 mRNA was localized to scattered round cells and dense cellular infiltrates, but only rarely to Schwann cell profiles. Double labeling studies revealed macrophages and subpopulations of T cells as the major cellular source of TGF-beta 1 mRNA. TGF-beta 1 protein was visualized immunocytochemically and localized to infiltrating mononuclear cells with peak expression around the same time as mRNA, in addition to some constitutive expression in axons and Schwann cells. Our studies suggest that the spontaneous recovery observed in Lewis rat EAN might be mediated by the endogenous elaboration of TGF-beta 1 within the peripheral nerve, and that macrophages might control their own cytotoxicity by expressing TGF-beta 1. Images Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 PMID:8546208

  4. Erythropoietin is a hypoxia inducible factor-induced protective molecule in experimental autoimmune neuritis.

    PubMed

    Luo, Bangwei; Jiang, Man; Yang, Xiaofeng; Zhang, Zhiyuan; Xiong, Jian; Schluesener, Hermann J; Zhang, Zhiren; Wu, Yuzhang

    2013-08-01

    Experimental autoimmune neuritis (EAN), an autoantigen-specific T-cell-mediated disease model for human demyelinating inflammatory disease of the peripheral nervous system, is characterized by self-limitation. Here we investigated the regulation and contribution of erythropoietin (EPO) in EAN self-limitation. In EAN sciatic nerves, hypoxia, and protein and mRNA levels of hypoxia-inducible factor 1α (HIF-1α), HIF-2α, EPO and EPO receptor (EPOR) were induced in parallel at disease peak phase but reduced at recovery periods. Further, the deactivation of HIF reduced EAN-induced EPO/EPOR upregulation in EAN, suggesting the central contribution of HIF to EPO/EPOR induction. The deactivation of EPOR signalling exacerbated EAN progression, implying that endogenous EPO contributed to EAN recovery. Exogenous EPO treatment greatly improved EAN recovery. In addition, EPO was shown to promote Schwann cell survival and myelin production. In EAN, EPO treatment inhibited lymphocyte proliferation and altered helper T cell differentiation by inducing increase of Foxp3(+)/CD4(+) regulatory T cells and decrease of IFN-γ(+)/CD4(+) Th1 cells. Furthermore, EPO inhibited inflammatory macrophage activation and promoted its phagocytic activity. In summary, our data demonstrated that EPO was induced in EAN by HIF and contributed to EAN recovery, and endogenous and exogenous EPO could effectively suppress EAN by attenuating inflammation and exerting direct cell protection, indicating that EPO contributes to the self-recovery of EAN and could be a potent candidate for treatment of autoimmune neuropathies. PMID:23603807

  5. Role of vestibular information in initiation of rapid postural responses

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

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

  6. Passive motion reduces vestibular balance and perceptual responses

    PubMed Central

    Fitzpatrick, Richard C; Watson, Shaun R D

    2015-01-01

    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 < 0.001) and remained elevated after 30 min. Over-estimation of whole-body rotation (30–180 deg every 5 s) before conditioning was significantly reduced (41.1 to 21.5%; P = 0.033). Conditioning reduced illusory vestibular sensations of rotation evoked by GVS (mean 113 deg for 10 s at 1 mA) by 44% (P < 0.01) and the effect persisted for at least 1 h (24% reduction; P < 0.05). We conclude that a system of 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. Key points Human activity exposes the vestibular organs to a wide dynamic range of motion. We aimed to discover whether the CNS regulates sensitivity to vestibular afference during exposure to ambient motion. Balance and perceptual

  7. Vestibular animal models: contributions to understanding physiology and disease.

    PubMed

    Straka, Hans; Zwergal, Andreas; Cullen, Kathleen E

    2016-04-01

    Our knowledge of the vestibular sensory system, its functional significance for gaze and posture stabilization, and its capability to ensure accurate spatial orientation perception and spatial navigation has greatly benefitted from experimental approaches using a variety of vertebrate species. This review summarizes the attempts to establish the roles of semicircular canal and otolith endorgans in these functions followed by an overview of the most relevant fields of vestibular research including major findings that have advanced our understanding of how this system exerts its influence on reflexive and cognitive challenges encountered during daily life. In particular, we highlight the contributions of different animal models and the advantage of using a comparative research approach. Cross-species comparisons have established that the morpho-physiological properties underlying vestibular signal processing are evolutionarily inherent, thereby disclosing general principles. Based on the documented success of this approach, we suggest that future research employing a balanced spectrum of standard animal models such as fish/frog, mouse and primate will optimize our progress in understanding vestibular processing in health and disease. Moreover, we propose that this should be further supplemented by research employing more "exotic" species that offer unique experimental access and/or have specific vestibular adaptations due to unusual locomotor capabilities or lifestyles. Taken together this strategy will expedite our understanding of the basic principles underlying vestibular computations to reveal relevant translational aspects. Accordingly, studies employing animal models are indispensible and even mandatory for the development of new treatments, medication and technical aids (implants) for patients with vestibular pathologies. PMID:27083880

  8. Prevalence of Vestibular Disorder in Older People Who Experience Dizziness

    PubMed Central

    Chau, Allan T.; Menant, Jasmine C.; Hübner, Patrick P.; Lord, Stephen R.; Migliaccio, Americo A.

    2015-01-01

    Dizziness and imbalance are clinically poorly defined terms, which affect ~30% of people over 65 years of age. In these people, it is often difficult to define the primary cause of dizziness, as it can stem from cardiovascular, vestibular, psychological, and neuromuscular causes. However, identification of the primary cause is vital in determining the most effective treatment strategy for a patient. Our aim is to accurately identify the prevalence of benign paroxysmal positional vertigo (BPPV), peripheral, and central vestibular hypofunction in people aged over 50 years who had experienced dizziness within the past year. Seventy-six participants aged 51–92 (mean ± SD = 69 ± 9.5 years) were tested using the head thrust dynamic visual acuity (htDVA) test, dizziness handicap inventory (DHI), as well as sinusoidal and unidirectional rotational chair testing, in order to obtain data for htDVA score, DHI score, sinusoidal (whole-body, 0.1–2 Hz with peak velocity at 30°/s) vestibulo-ocular reflex (VOR) gain and phase, transient (whole-body, acceleration at 150°/s2 to a constant velocity rotation of 50°/s) VOR gain and time constant (TC), optokinetic nystagmus (OKN) gain, and TC (whole-body, constant velocity rotation at 50°/s). We found that BPPV, peripheral and central vestibular hypofunction were present in 38 and 1% of participants, respectively, suggesting a likely vestibular cause of dizziness in these people. Of those with a likely vestibular cause, 63% had BPPV; a figure higher than previously reported in dizziness clinics of ~25%. Our results indicate that htDVA, sinusoidal (particularly 0.5–1 Hz), and transient VOR testing were the most effective at detecting people with BPPV or vestibular hypofunction, whereas DHI and OKN were effective at only detecting non-BPPV vestibular hypofunction. PMID:26733940

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

    NASA Technical Reports Server (NTRS)

    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

  10. Genetics of Peripheral Vestibular Dysfunction: Lessons from Mutant Mouse Strains

    PubMed Central

    Jones, Sherri M.; Jones, Timothy A.

    2015-01-01

    Background A considerable amount of research has been published about genetic hearing impairment. Fifty to sixty percent of hearing loss is thought to have a genetic cause. Genes may also play a significant role in acquired hearing loss due to aging, noise exposure, or ototoxic medications. Between 1995 and 2012, over 100 causative genes have been identified for syndromic and nonsyndromic forms of hereditary hearing loss (see Hereditary Hearing Loss Homepage http://hereditaryhearingloss.org). Mouse models have been extremely valuable in facilitating the discovery of hearing loss genes, and in understanding inner ear pathology due to genetic mutations or elucidating fundamental mechanisms of inner ear development. Purpose Whereas much is being learned about hereditary hearing loss and the genetics of cochlear disorders, relatively little is known about the role genes may play in peripheral vestibular impairment. Here we review the literature with regard to genetics of vestibular dysfunction and discuss what we have learned from studies using mutant mouse models and direct measures of peripheral vestibular neural function. Results Several genes are considered that when mutated lead to varying degrees of inner ear vestibular dysfunction due to deficits in otoconia, stereocilia, hair cells, or neurons. Behavior often does not reveal the inner ear deficit. Many of the examples presented are also known to cause human disorders. Conclusions Knowledge regarding the roles of particular genes in the operation of the vestibular sensory apparatus is growing and it is clear that gene products co-expressed in the cochlea and vestibule may play different roles in the respective end organs. The discovery of new genes mediating critical inner ear vestibular function carries the promise of new strategies in diagnosing, treating and managing patients as well as predicting the course and level of morbidity in human vestibular disease. PMID:25032973

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

    PubMed

    Saldaña-Ruíz, Sandra; Hernández-Mir, Gerard; Sedó-Cabezón, Lara; Cutillas, Blanca; Llorens, Jordi

    2012-06-20

    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 2.0mmol/kg, oral, in corn oil) and assessed for changes in open field activity and rating scores in a test battery for vestibular dysfunction. Surface preparations of the vestibular sensory epithelia were observed for hair cell loss using scanning electron microscopy. A separate experiment examined the impact of pre-treatment with the universal CYP inhibitor,1-aminobenzotriazole, on the effect of cis-2-pentenenitrile on vestibular rating scores. The occurrence of degenerating neurons in the central nervous system was assessed by Fluoro-Jade C staining. cis-2-Pentenenitrile had a dose-dependent effect on body weight. Rats receiving 1.50mmol/kg or more of cis-2-pentenenitrile displayed reduced rearing activity in the open field and increased rating scores on the vestibular dysfunction test battery. Hair cell loss was observed in the vestibular sensory epithelia and correlated well with the behavioral deficits. Pre-treatment with 1-aminobenzotriazole blocked the behavioral effect. Fluoro-Jade C staining did not reveal significant neuronal degeneration in the central nervous system apart from neurite labeling in the olfactory glomeruli. We conclude that cis-2-pentenenitrile causes vestibular toxicity in a similar way to allylnitrile, cis-crotononitrile and 3,3'-iminodipropionitrile (IDPN), and also shares other targets such as the olfactory system with these other nitriles. The present data also suggest that CYP-mediated bioactivation is involved in cis-2-pentenenitrile toxicity. PMID:22546275

  12. Passive motion reduces vestibular balance and perceptual responses.

    PubMed

    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 < 0.001) and remained elevated after 30 min. Over-estimation of whole-body rotation (30-180 deg every 5 s) before conditioning was significantly reduced (41.1 to 21.5%; P = 0.033). Conditioning reduced illusory vestibular sensations of rotation evoked by GVS (mean 113 deg for 10 s at 1 mA) by 44% (P < 0.01) and the effect persisted for at least 1 h (24% reduction; P < 0.05). We conclude that a system of 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

  13. Prevalence of Vestibular Disorder in Older People Who Experience Dizziness.

    PubMed

    Chau, Allan T; Menant, Jasmine C; Hübner, Patrick P; Lord, Stephen R; Migliaccio, Americo A

    2015-01-01

    Dizziness and imbalance are clinically poorly defined terms, which affect ~30% of people over 65 years of age. In these people, it is often difficult to define the primary cause of dizziness, as it can stem from cardiovascular, vestibular, psychological, and neuromuscular causes. However, identification of the primary cause is vital in determining the most effective treatment strategy for a patient. Our aim is to accurately identify the prevalence of benign paroxysmal positional vertigo (BPPV), peripheral, and central vestibular hypofunction in people aged over 50 years who had experienced dizziness within the past year. Seventy-six participants aged 51-92 (mean ± SD = 69 ± 9.5 years) were tested using the head thrust dynamic visual acuity (htDVA) test, dizziness handicap inventory (DHI), as well as sinusoidal and unidirectional rotational chair testing, in order to obtain data for htDVA score, DHI score, sinusoidal (whole-body, 0.1-2 Hz with peak velocity at 30°/s) vestibulo-ocular reflex (VOR) gain and phase, transient (whole-body, acceleration at 150°/s(2) to a constant velocity rotation of 50°/s) VOR gain and time constant (TC), optokinetic nystagmus (OKN) gain, and TC (whole-body, constant velocity rotation at 50°/s). We found that BPPV, peripheral and central vestibular hypofunction were present in 38 and 1% of participants, respectively, suggesting a likely vestibular cause of dizziness in these people. Of those with a likely vestibular cause, 63% had BPPV; a figure higher than previously reported in dizziness clinics of ~25%. Our results indicate that htDVA, sinusoidal (particularly 0.5-1 Hz), and transient VOR testing were the most effective at detecting people with BPPV or vestibular hypofunction, whereas DHI and OKN were effective at only detecting non-BPPV vestibular hypofunction. PMID:26733940

  14. Older adults demonstrate superior vestibular perception for virtual rotations.

    PubMed

    Peters, Ryan M; Blouin, Jean-Sébastien; Dalton, Brian H; Inglis, J Timothy

    2016-09-01

    Adult ageing results in a progressive loss of vestibular hair cell receptors and afferent fibres. Given the robustness of vestibulo-ocular and vestibular-evoked whole-body responses to age-related deterioration, it was proposed that the vestibular system compensates centrally. Here we examine the potential for central compensation in vestibular sensitivity with adult ageing by using a combination of real and virtual rotation-based psychophysical testing at two stimulus frequencies (0.1 & 1Hz). Real rotations activate semi-circular canal hair cell receptors naturally via mechanotransduction, while electrical current used to evoke virtual rotations does not rely on mechanical deformation of hair cell receptors to activate vestibular afferents. This two-pronged approach allows us to determine the independent effects of age-related peripheral afferent receptor loss and potential compensatory mechanisms. Older adults had thresholds for discriminating real rotations that were significantly greater than young adults at 0.1Hz (7.2 vs. 3°/s), but the effect of age was weaker (non-significant) at 1Hz (2.4 vs. 1.3°/s). For virtual rotations, older adults had greater thresholds than young adults at 0.1Hz (1.2 vs. 0.5mA), however, older adults outperformed young adults at 1Hz (0.6 vs. 1.1mA). Based on these thresholds, we argue that central vestibular processing gain is enhanced in older adults for 1Hz real and virtual rotations, partially offsetting the negative impact of normal age-related hair cell receptor and primary afferent loss. We propose that the frequency dependence of this compensation reflects the physiological importance of the 1-5Hz range in natural vestibular input. PMID:27262689

  15. Vestibular Migraine (a.k.a.Migraine Associated Vertigo or [MAV])

    MedlinePlus

    ... is a Top Rated Nonprofit! Volunteer. Donate. Review. Vestibular Migraine (a.k.a. Migraine Associated Vertigo or ... Wackym on his You Tube Channel. Migraine and vestibular dysfunction Approximately 40% of migraine patients have some ...

  16. Fifth Symposium on the Role of the Vestibular Organs in Space Exploration

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Vestibular problems of manned space flight are investigated for weightlessness and reduced gravity conditions with emphasis on space station development. Intensive morphological studies on the vestibular system and its central nervous system connections are included.

  17. Effects of microgravity on vestibular ontogeny: direct physiological and anatomical measurements following space flight (STS-29)

    NASA Technical Reports Server (NTRS)

    Jones, T. A.; Fermin, C.; Hester, P. Y.; Vellinger, J.

    1993-01-01

    Does space flight change gravity receptor development? The present study measured vestibular form and function in birds flown as embryos for 5 days in earth orbit (STS-29). No major changes in vestibular gross morphology were found. Vestibular response mean amplitudes and latencies were unaffected by space flight. However, the results of measuring vestibular thresholds were mixed and abnormal responses in 3 of the 8 flight animals raise important questions.

  18. Projections from the parabrachial nucleus to the vestibular nuclei: potential substrates for autonomic and limbic influences on vestibular responses.

    PubMed

    Balaban, Carey D

    2004-01-16

    Previous anatomical studies in rabbits and rats have shown that the superior vestibular nucleus (SVN), medial vestibular nucleus (MVN) and inferior vestibular nucleus (IVN) project to the parabrachial nucleus (PBN) and Kölliker-Fuse (KF) nucleus. Adult male albino rabbits and Long-Evans rats received iontophoretic injections of biotinylated dextran amine, Phaseolus vulgaris leucoagglutinin, Fluoro-Gold or tetramethylrhodamine dextran amine into either the vestibular nuclei or the PBN and KF nuclei. The results were similar in both rats and rabbits. Injections of retrograde tracers into the vestibular nuclei produced retrogradely labeled neurons bilaterally in caudal third of the medial, external medial, and external lateral PBN in both species, with more variable labeling in KF. Rats also had consistent bilateral (predominantly contralateral) labeling in the ventrolateral PBN. The most prominent labeling was produced from injections that included the SVN, with fewer labeled neurons observed from injections in the caudal MVN and the IVN. Anterograde transport of BDA from injections into the PBN and KF nuclei of rabbits revealed prominent projections to the SVN, dorsal aspect of the rostral MVN, caudal MVN, pars beta of the LVN and IVN. These connections appear to contain a component that is reciprocal to the vestibulo-parabrachial pathway and a non-reciprocal component to regions connected with the vestibulocerebellum and vestibulo-motor reflex pathways. These connections support the concept that a synthesis of autonomic, vestibular and limbic information is an integral property of pathways related to balance control in both the brain stem and forebrain. It is suggested that these projections may contribute broadly to both performance tradeoffs in vestibular-related pathways during variations in the behavioral context and affective state and the close association between anxiety and balance function. PMID:14670639

  19. Biomedical performance monitoring and assessment of astronauts by means of an ocular vestibular monitoring system

    NASA Astrophysics Data System (ADS)

    Souvestre, Philippe A.; Landrock, Clinton

    2007-02-01

    The paper focuses on the strong correlation between unmitigated symptoms exhibited by post Space flight astronauts, and symptoms associated with postural deficiency syndrome (PDS) that can be correctly assessed, identified, and monitored via a neurophysiological ocular-vestibular monitoring system (OVMS). From examining clinical data taken over a 10-year period from patients experiencing PDS related acute and chronic post-traumatic medical conditions, the authors show the potential for current assessment and monitoring techniques to examine better the impacts on astronaut neurophysiology. The data presented provide strong evidence that this biomedical monitoring and assessment methodology along with appropriate technology can lead to a better understanding of astronaut post-flight neurophysiology, which is necessary if human exploration in Space is to continue on a successful path.

  20. A Critical Look at Vestibular Dysfunction in Learning-Disabled Children.

    ERIC Educational Resources Information Center

    Polatajko, Helene J.

    1985-01-01

    The vestibular function was examined in 40 learning disabled and 40 non LD children. Data indicated no significant difference between normal and LD Ss, no significant correlation between vestibular function and academic achievement, and no significant educational relevance in categorizing LD Ss according to vestibular dimensions. (CL)

  1. MMP-2 -1575G/A polymorphism modifies the onset of optic neuritis as a first presenting symptom in MS?

    PubMed

    Gašparović, Iva; Čizmarević, Nada Starčević; Lovrečić, Luca; Perković, Olivio; Lavtar, Polona; Sepčić, Juraj; Jazbec, Saša Šega; Kapović, Miljenko; Peterlin, Borut; Ristić, Smiljana

    2015-09-15

    Previous studies show altered activities of matrix metalloproteinase (MMP)-2 and MMP-9 in serum and cerebrospinal fluid of multiple sclerosis (MS) and neuromyelitis optica (NMO) patients. Optic neuritis (ON) is a common symptom of both disorders. Here we investigated the impacts of MMP-2 -1575G/A and MMP-9 -1562 C/T gene polymorphisms on disease phenotype in 100 MS patients with ON as a first symptom and 376 MS patients with other initial symptomatology. The MMP-2 -1575G/A polymorphism led to a 5-year-earlier age of disease onset in MS patients with ON as a first symptom (p=0.009). PMID:26298319

  2. Otolith-Canal Convergence In Vestibular Nuclei Neurons

    NASA Technical Reports Server (NTRS)

    Dickman, J. David; Si, Xiao-Hong

    2002-01-01

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

  3. [Modern means of statokinetic improvement and vestibular rehabilitation].

    PubMed

    Syroezhkin, F A; Buinov, L G; Dvoryanchikov, V V; Blaginin, A A

    2016-04-01

    The article presents the results of studying the effectiveness of the complex vestibular workouts based on non-invasive neuromodulation technology in 37 healthy patients aged 18-20 years who have symptoms of aerial sickness in 5 or less minutes. Non-invasive neuromodulation wire-familiarize with the apparatus for vestibular rehabilitation "Brain-Port" (USA), performing electric tactile stimulation of the tongue with biofeedback. An indicator of statokinetic stability was considered from time to tolerance to the vestibular load up to development of vegetative manifestations of aerial sickness. 'Improvement of statokinetic tolerability vestibular training confirmed by computed posturography and gait analysis. Increase of statokinetic stability accompanied not only by an increase in exposure, necessary for motion sickness, but also a decrease in autonomic manifestations, which are the main obstacle to the operator's military activities. Improving balance and gait performance after the swipe-of vestibular training course demonstrates the possible realization of two mechanisms of compensatory and restorative processes: sensory substitution equilibrium function and induction of neuroplasticity in short time. PMID:27416720

  4. Action Representation in Patients with Bilateral Vestibular Impairments

    PubMed Central

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

    2011-01-01

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

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

    PubMed Central

    2010-01-01

    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. PMID:20815905

  6. Screening people in the waiting room for vestibular impairments

    PubMed Central

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

    2014-01-01

    Objective Primary care physicians need good screening tests of the vestibular system to help them determine whether patients who complain of dizziness should be evaluated for vestibular disorders. The goal of this study was to determine if current, widely-used screening tests of the vestibular system predict subsequent performance on objective diagnostic tests of the vestibular system (ENG). Setting and subjects Of 300 subjects who were recruited from the waiting room of a primary care clinic and were screened there 69 subjects subsequently volunteered for ENGs in the otolaryngology department. The screening study included age, history of vertigo, head impulse tests, Dix-Hallpike maneuvers, and Clinical Test of Sensory Integration and Balance (CTSIB) with head still and head pitching at 0.33 Hz. The ENG included Dix-Hallpike tests, vestibular evoked myogenic potentials, bi-thermal water caloric tests, and low frequency sinusoids in the rotatory chair in darkness. Results The scores on the screening were related to the total ENG but odds ratios were not significant for some variables probably due to the small sample size. Conclusions A larger sample may have yielded stronger results but in general the high odds ratios suggest a relationship between the ENG score and Dix-Hallpike responses and between the ENG scores and some CTSIB responses. PMID:25188617

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

    PubMed

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

    2015-03-01

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

  8. Experimental optic neuritis induced by the microinjection of lipopolysaccharide into the optic nerve.

    PubMed

    Aranda, Marcos L; Dorfman, Damián; Sande, Pablo H; Rosenstein, Ruth E

    2015-04-01

    Optic neuritis (ON) is a condition involving primary inflammation, demyelination, and axonal injury in the optic nerve which leads to retinal ganglion cell (RGC) loss, and visual dysfunction. We investigated the ability of a single microinjection of bacterial lipopolysaccharide (LPS) directly into the optic nerve to induce functional and structural alterations compatible with ON. For this purpose, optic nerves from male Wistar rats remained intact or were injected with vehicle or LPS. The effect of LPS was evaluated at several time points post-injection in terms of: i) visual pathway and retinal function (visual evoked potentials (VEPs) and electroretinograms, (ERGs), respectively), ii) anterograde transport from the retina to its projection areas, iii) consensual pupil light reflex (PLR), iv) optic nerve histology, v) microglia/macrophage reactivity (by Iba-1- and ED1-immunostaining), vi) astrocyte reactivity (by glial fibrillary acid protein-immunostaining), vii) axon number (by toluidine blue staining), vii) demyelination (by myelin basic protein immunoreactivity and luxol fast blue staining), viii) optic nerve ultrastructure, and ix) RGC number (by Brn3a immunoreactivity). LPS induced a significant and persistent decrease in VEP amplitude and PLR, without changes in the ERG. In addition, LPS induced a deficit in anterograde transport, and an early inflammatory response consisting in an increased cellularity, and Iba-1 and ED1-immunoreactivity in the optic nerve, which were followed by changes in axonal density, astrocytosis, demyelination, and axon and RGC loss. These results suggest that the microinjection of LPS into the optic nerve may serve as a new experimental model of primary ON. PMID:25687552

  9. Forced Exercise Preconditioning Attenuates Experimental Autoimmune Neuritis by Altering Th1 Lymphocyte Composition and Egress.

    PubMed

    Calik, Michael W; Shankarappa, Sahadev A; Langert, Kelly A; Stubbs, Evan B

    2015-01-01

    A short-term exposure to moderately intense physical exercise affords a novel measure of protection against autoimmune-mediated peripheral nerve injury. Here, we investigated the mechanism by which forced exercise attenuates the development and progression of experimental autoimmune neuritis (EAN), an established animal model of Guillain-Barré syndrome. Adult male Lewis rats remained sedentary (control) or were preconditioned with forced exercise (1.2 km/day × 3 weeks) prior to P2-antigen induction of EAN. Sedentary rats developed a monophasic course of EAN beginning on postimmunization day 12.3 ± 0.2 and reaching peak severity on day 17.0 ± 0.3 (N = 12). By comparison, forced-exercise preconditioned rats exhibited a similar monophasic course but with significant (p < .05) reduction of disease severity. Analysis of popliteal lymph nodes revealed a protective effect of exercise preconditioning on leukocyte composition and egress. Compared with sedentary controls, forced exercise preconditioning promoted a sustained twofold retention of P2-antigen responsive leukocytes. The percentage distribution of pro-inflammatory (Th1) lymphocytes retained in the nodes from sedentary EAN rats (5.1 ± 0.9%) was significantly greater than that present in nodes from forced-exercise preconditioned EAN rats (2.9 ± 0.6%) or from adjuvant controls (2.0 ± 0.3%). In contrast, the percentage of anti-inflammatory (Th2) lymphocytes (7-10%) and that of cytotoxic T lymphocytes (∼20%) remained unaltered by forced exercise preconditioning. These data do not support an exercise-inducible shift in Th1:Th2 cell bias. Rather, preconditioning with forced exercise elicits a sustained attenuation of EAN severity, in part, by altering the composition and egress of autoreactive proinflammatory (Th1) lymphocytes from draining lymph nodes. PMID:26186926

  10. Devic's disease before Devic: Bilateral optic neuritis and simultaneous myelitis in a young woman (1874).

    PubMed

    Jarius, S; Wildemann, B

    2015-11-15

    Neuromyelitis optica (NMO, Devic's disease) is an often severely disabling disorder of the central nervous system (CNS) which mainly affects the optic nerves and spinal cord. NMO was long considered a clinical subform of multiple sclerosis (MS). In 2004, however, Lennon and colleagues described a novel autoantibody in NMO which targets aquaporin-4, the most abundant water channel in the CNS, and which was later shown to be directly pathogenic. This has led to the recognition of NMO as a distinct disease entity in its own right. While the history of 'classical' MS has been extensively studied, only little is known about the early history of NMO. The term neuromyelitis optica was coined in 1894 by Eugène Devic (1858-1930) and Fernand Gault (1873-1936), who were the first to provide a systematic description of that disorder. Here we re-present a very early description of a case of NMO by a Polish physician, Adolf Wurst, which appeared in 1876 in Przegląd Lekarski, one of the oldest Polish medical journals. This report predates Devic and Gault's seminal work on NMO by more than two decades. The patient, a 30-year-old woman, subacutely developed simultaneous bilateral optic neuritis with papilloedema and bilateral blindness and transverse myelitis with severe paraparesis, anaesthesia, and bladder and bowel dysfunction. At last follow-up, one year after onset, she had recovered except for a residual spastic gait and some visual deficit on the right side. Of note, this is the first known case of NMO in a Caucasian patient ever reported outside Western Europe. PMID:26303625

  11. Deconvolution of the vestibular evoked myogenic potential.

    PubMed

    Lütkenhöner, Bernd; Basel, Türker

    2012-02-01

    The vestibular evoked myogenic potential (VEMP) and the associated variance modulation can be understood by a convolution model. Two functions of time are incorporated into the model: the motor unit action potential (MUAP) of an average motor unit, and the temporal modulation of the MUAP rate of all contributing motor units, briefly called rate modulation. The latter is the function of interest, whereas the MUAP acts as a filter that distorts the information contained in the measured data. Here, it is shown how to recover the rate modulation by undoing the filtering using a deconvolution approach. The key aspects of our deconvolution algorithm are as follows: (1) the rate modulation is described in terms of just a few parameters; (2) the MUAP is calculated by Wiener deconvolution of the VEMP with the rate modulation; (3) the model parameters are optimized using a figure-of-merit function where the most important term quantifies the difference between measured and model-predicted variance modulation. The effectiveness of the algorithm is demonstrated with simulated data. An analysis of real data confirms the view that there are basically two components, which roughly correspond to the waves p13-n23 and n34-p44 of the VEMP. The rate modulation corresponding to the first, inhibitory component is much stronger than that corresponding to the second, excitatory component. But the latter is more extended so that the two modulations have almost the same equivalent rectangular duration. PMID:22079097

  12. Spatial orientation - Visual-vestibular-somatic interaction

    NASA Technical Reports Server (NTRS)

    Parker, D. E.; Poston, R. L.; Gulledge, W. L.

    1983-01-01

    The compensation signals from somatosensory and vestibular receptors, which act to compensate for disturbances produced by the displacement of our eyes relative to other parts of our bodies and for visual disturbances such as tilted frames or moving visual fields, are investigated. Disturbances were evoked by tilting the head and by rotating a large visual display, while compensation signals related to gravity were altered by placing the subjects horizontally on a board or seating them vertically. The first experiment studied the effects of visual disturbance on the ability of supine observers to set a line to the longitudinal body axis while the head was tilted toward one shoulder or while the head was straight. Results showed that the effects of the visual disturbance were greater when the head was tilted than when it was straight, which indicates that the effects of visual disturbance were greater for a task that required compensation. The second experiment compared the performance of supine and erect observers. No differences were found between the performance of observers on a task requiring the use of compensation signals under these two conditions, which suggests that the enrichment of compensatory signals did not reduce the effects of visual disturbancs.

  13. Microgravity vestibular investigations (10-IML-1)

    NASA Technical Reports Server (NTRS)

    Reschke, Millard F.

    1992-01-01

    Our perception of how we are oriented in space is dependent on the interaction of virtually every sensory system. For example, to move about in our environment we integrate inputs in our brain from visual, haptic (kinesthetic, proprioceptive, and cutaneous), auditory systems, and labyrinths. In addition to this multimodal system for orientation, our expectations about the direction and speed of our chosen movement are also important. Changes in our environment and the way we interact with the new stimuli will result in a different interpretation by the nervous system of the incoming sensory information. We will adapt to the change in appropriate ways. Because our orientation system is adaptable and complex, it is often difficult to trace a response or change in behavior to any one source of information in this synergistic orientation system. However, with a carefully designed investigation, it is possible to measure signals at the appropriate level of response (both electrophysiological and perceptual) and determine the effect that stimulus rearrangement has on our sense of orientation. The environment of orbital flight represents the stimulus arrangement that is our immediate concern. The Microgravity Vestibular Investigations (MVI) represent a group of experiments designed to investigate the effects of orbital flight and a return to Earth on our orientation system.

  14. Vestibular afferent responses to microrotational stimuli

    NASA Technical Reports Server (NTRS)

    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.

  15. Effect of 30-min +3 Gz centrifugation on vestibular and autonomic cardiovascular function

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd T.; Wood, Scott J.; Brown, Troy E.; Harm, Deborah L.; Rupert, A. H.

    2003-01-01

    INTRODUCTION: Repeated exposure to increased +Gz enhances human baroreflex responsiveness and improves tolerance to cardiovascular stress. However, it is not known whether such enhancements might also result from a single, more prolonged exposure to increased +Gz. Our study was designed to investigate whether baroreflex function and orthostatic tolerance are acutely improved by a single prolonged exposure to +3 Gz, and moreover, whether changes in autonomic cardiovascular function resulting from exposure to increased +Gz are correlated with changes in otolith function. METHODS: We exposed 15 healthy human subjects to +3 Gz centrifugation for up to 30 min or until symptoms of incipient G-induced loss of consciousness (G-LOC) ensued. Tests of autonomic cardiovascular function both before and after centrifugation included: 1) power spectral determinations of beat-to-beat R-R intervals and arterial pressures; 2) carotid-cardiac baroreflex tests; 3) Valsalva tests; and 4) 30-min head-up tilt tests. Otolith function was assessed during centrifugation by the linear vestibulo-ocular reflex and both before and after centrifugation by measurements of ocular counter-rolling and dynamic posturography. RESULTS: Of the 15 subjects who underwent prolonged +3 Gz, 4 were intolerant to 30 min of head-up tilt before centrifugation but became tolerant to such tilt after centrifugation. The Valsalva-related baroreflex as well as a measure of the carotid-cardiac baroreflex were also enhanced after centrifugation. No significant vestibular-autonomic relationships were detected beyond a vestibular-cerebrovascular interaction reported earlier in a subset of seven participants. CONCLUSIONS: A single prolonged exposure to +3 Gz centrifugation acutely improves baroreflex function and orthostatic tolerance.

  16. Effect of Sustained Human Centrifugation on Autonomic Cardiovascular and Vestibular Function

    NASA Technical Reports Server (NTRS)

    Schlegel, Todd T.; Wood, Scott J.; Brown, Troy E.; Benavides, Edgar W.; Harm, Deborah L.; Rupert, A. H.

    2002-01-01

    Repeated exposure to +Gz enhances human baroreflex responsiveness and improves tolerance to cardiovascular stress. However, both sustained exposure to +Gx and changes in otolith function resulting from the gravitational changes of space flight and parabolic flight may adversely affect autonomic cardiovascular function and orthostatic tolerance. HYPOTHESES: Baroreflex function and orthostatic tolerance are acutely improved by a single sustained (30 min) exposure to +3Gz but not +3Gx. Moreover, after 30 min of +3Gx, any changes that occur in autonomic cardiovascular function will relate commensurately to changes in otolith function. METHODS: Twenty-two healthy human subjects were first exposed to 5 min of +3 Gz centrifugation and then subsequently up to a total of30 min of either +3Gz (n = 15) or +3Gx (n = 7) centrifugation. Tests of autonomic cardiovascular function both before and after both types of centrifugation included: (a) power spectral determinations of beat-to-beat R-R intervals and arterial pressures; (b) carotid-cardiac baroreflex tests; ( c) Valsalva tests; and (d) 30-min head-up tilt (HUT) tests. Otolith function was assessed during centrifugation by the linear vestibulo-ocular reflex and both before and after centrifugation by measurements of ocular counter-rolling and dynamic posturography. RESULTS: All four +3Gz subjects who were intolerant to HUT before centrifugation became tolerant to HUT after centrifugation. The operational point of the carotid-cardiac baroreflex and the Valsalva-related baroreflex were also enhanced in the +3Gz group but not in the +3Gx group. No significant vestibular-autonomic relationships were detected, other than a significant vestibular-cerebrovascular interaction reported previously. CONCLUSIONS: A single, sustained exposure to +3 Gz centrifugation acutely improves baroreflex function and orthostatic tolerance whereas a similar exposure to +3 Gx centrifugation appears to have less effect.

  17. Comparative analysis of pharmacological treatments with N-acetyl-dl-leucine (Tanganil) and its two isomers (N-acetyl-L-leucine and N-acetyl-D-leucine) on vestibular compensation: Behavioral investigation in the cat.

    PubMed

    Tighilet, Brahim; Leonard, Jacques; Bernard-Demanze, Laurence; Lacour, Michel

    2015-12-15

    Head roll tilt, postural imbalance and spontaneous nystagmus are the main static vestibular deficits observed after an acute unilateral vestibular loss (UVL). In the UVL cat model, these deficits are fully compensated over 6 weeks as the result of central vestibular compensation. N-Acetyl-dl-leucine is a drug prescribed in clinical practice for the symptomatic treatment of acute UVL patients. The present study investigated the effects of N-acetyl-dl-leucine on the behavioral recovery after unilateral vestibular neurectomy (UVN) in the cat, and compared the effects of each of its two isomers N-acetyl-L-leucine and N-acetyl-D-leucine. Efficacy of these three drug treatments has been evaluated with respect to a placebo group (UVN+saline water) on the global sensorimotor activity (observation grids), the posture control (support surface measurement), the locomotor balance (maximum performance at the rotating beam test), and the spontaneous vestibular nystagmus (recorded in the light). Whatever the parameters tested, the behavioral recovery was strongly and significantly accelerated under pharmacological treatments with N-acetyl-dl-leucine and N-acetyl-L-leucine. In contrast, the N-acetyl-D-leucine isomer had no effect at all on the behavioral recovery, and animals of this group showed the same recovery profile as those receiving a placebo. It is concluded that the N-acetyl-L-leucine isomer is the active part of the racemate component since it induces a significant acceleration of the vestibular compensation process similar (and even better) to that observed under treatment with the racemate component only. PMID:26607469

  18. Herpes zoster-associated acute urinary retention in immunocompetent patient.

    PubMed

    Marques, Silvio Alencar; Hortense, Juliana

    2014-01-01

    Herpes zoster-associated urinary retention is an uncommon event related to virus infection of the S2-S4 dermatome. The possible major reasons are ipsilateral hemicystitis, neuritis-induced or myelitis-associated virus infection. We report a case of a 65-year-old immunocompetent female patient who presented an acute urinary retention after four days under treatment with valacyclovir for gluteal herpes zoster. The patient had to use a vesical catheter, was treated with antibiotics and corticosteroids and fully recovered after eight weeks. PMID:25387508

  19. Rapid adaptation of multisensory integration in vestibular pathways.

    PubMed

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

    2015-01-01

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

  20. An electronic prosthesis mimicking the dynamic vestibular function

    NASA Astrophysics Data System (ADS)

    Shkel, Andrei M.

    2006-03-01

    This paper reports our progress toward development of a unilateral vestibular prosthesis. The sensing element of the prosthesis is a custom designed one-axis MEMS gyroscope. Similarly to the natural semicircular canal, the microscopic gyroscope senses angular motion of the head and generates voltages proportional to the corresponding angular accelerations. Then, voltages are sent to the pulse generating unit where angular motion is translated into voltage pulses. The voltage pulses are converted into current pulses and are delivered through specially designed electrodes, conditioned to stimulate the corresponding vestibular nerve branch. Our preliminary experimental evaluations of the prosthesis on a rate table indicate that the device's output matches the average firing rate of vestibular neurons to those in animal models reported in the literature. The proposed design is scalable; the sensing unit, pulse generator, and the current source can be potentially implemented on a single chip using integrated MEMS technology.

  1. [Vestibular dysfunction in the postpartum period following gestosis].

    PubMed

    Likhachev, S A; Astapenko, A V; Osos, E L; Tarasevich, N M

    2010-01-01

    The state of the vestibular system was evaluated in 30 postpartum women following gestosis and 25 controls after uncomplicated pregnancy. Examination using the electronystagmographic technique failed to reveal spontaneous nystagmus (Ny) in the latter group whereas 13.3% and 30% women of the former group had it with the eyes open and closed respectively. Provocative functional tests significantly improved detectability of Ny. Hyperventilation was associated with Ny in 80% and 12% of the women after complicated and uneventful pregnancy respectively while orthostatic test revealed Ny in 63% and 12% of them. Active head rotation with closed eyes produced well-apparent experimental Ny in women of both groups, but it was significantly more pronounced in the former one. Post-gestosis women displayed markedly impaired reaction in vestibular-ocular reflex suppression test. It is concluded that 80% of the women with complicated pregnancy exhibited vestibular dysfunction of central origin in the postpartum period. PMID:20517270

  2. Visuo-vestibular eye movements: infantile strabismus in 3 dimensions.

    PubMed

    Brodsky, Michael C

    2005-06-01

    Infantile strabismus is accompanied by latent nystagmus, primary inferior oblique muscle overaction, and dissociated vertical divergence. If we examine the evolutionary underpinnings of these ocular rotations, we can construct a unifying mechanism for the sensorimotor abnormalities that arise in humans with infantile strabismus. Latent nystagmus, primary inferior oblique muscle overaction, and dissociated vertical divergence correspond to visual balancing reflexes that are operative in lateral-eyed animals in yaw, pitch, and roll, respectively. In humans with infantile strabismus, these subcortical visual reflexes are reactivated by a physiologic imbalance in binocular visual input, which resets central vestibular tone in 3-dimensional space. These visual reflexes reveal the evolutionary role of the eyes as sensory balance organs that can directly modulate central vestibular tone. Latent nystagmus, primary oblique muscle overaction, and dissociated vertical divergence should be reclassified as visuo-vestibular eye movements. PMID:15955986

  3. Rapid adaptation of multisensory integration in vestibular pathways

    PubMed Central

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

    2015-01-01

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

  4. The Effects of Aging on Clinical Vestibular Evaluations

    PubMed Central

    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

  5. Modulation of human vestibular reflexes with increased postural threat

    PubMed Central

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

    2014-01-01

    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

  6. Kv1 channels and neural processing in vestibular calyx afferents.

    PubMed

    Meredith, Frances L; Kirk, Matthew E; Rennie, Katherine J

    2015-01-01

    Potassium-selective ion channels are important for accurate transmission of signals from auditory and vestibular sensory end organs to their targets in the central nervous system. During different gravity conditions, astronauts experience altered input signals from the peripheral vestibular system resulting in sensorimotor dysfunction. Adaptation to altered sensory input occurs, but it is not explicitly known whether this involves synaptic modifications within the vestibular epithelia. Future investigations of such potential plasticity require a better understanding of the electrophysiological mechanisms underlying the known heterogeneity of afferent discharge under normal conditions. This study advances this understanding by examining the role of the Kv1 potassium channel family in mediating action potentials in specialized vestibular afferent calyx endings in the gerbil crista and utricle. Pharmacological agents selective for different sub-types of Kv1 channels were tested on membrane responses in whole cell recordings in the crista. Kv1 channels sensitive to α-dendrotoxin and dendrotoxin-K were found to prevail in the central regions, whereas K(+) channels sensitive to margatoxin, which blocks Kv1.3 and 1.6 channels, were more prominent in peripheral regions. Margatoxin-sensitive currents showed voltage-dependent inactivation. Dendrotoxin-sensitive currents showed no inactivation and dampened excitability in calyces in central neuroepithelial regions. The differential distribution of Kv1 potassium channels in vestibular afferents supports their importance in accurately relaying gravitational and head movement signals through specialized lines to the central nervous system. Pharmacological modulation of specific groups of K(+) channels could help alleviate vestibular dysfunction on earth and in space. PMID:26082693

  7. Exploration of Circadian Rhythms in Patients with Bilateral Vestibular Loss

    PubMed Central

    Martin, Tristan; Moussay, Sébastien; Bulla, Ingo; Bulla, Jan; Toupet, Michel; Etard, Olivier; Denise, Pierre; Davenne, Damien; Coquerel, Antoine; Quarck, Gaëlle

    2016-01-01

    Background New insights have expanded the influence of the vestibular system to the regulation of circadian rhythmicity. Indeed, hypergravity or bilateral vestibular loss (BVL) in rodents causes a disruption in their daily rhythmicity for several days. The vestibular system thus influences hypothalamic regulation of circadian rhythms on Earth, which raises the question of whether daily rhythms might be altered due to vestibular pathology in humans. The aim of this study was to evaluate human circadian rhythmicity in people presenting a total bilateral vestibular loss (BVL) in comparison with control participants. Methodology and Principal Findings Nine patients presenting a total idiopathic BVL and 8 healthy participants were compared. Their rest-activity cycle was recorded by actigraphy at home over 2 weeks. The daily rhythm of temperature was continuously recorded using a telemetric device and salivary cortisol was recorded every 3 hours from 6:00AM to 9:00PM over 24 hours. BVL patients displayed a similar rest activity cycle during the day to control participants but had higher nocturnal actigraphy, mainly during weekdays. Sleep efficiency was reduced in patients compared to control participants. Patients had a marked temperature rhythm but with a significant phase advance (73 min) and a higher variability of the acrophase (from 2:24 PM to 9:25 PM) with no correlation to rest-activity cycle, contrary to healthy participants. Salivary cortisol levels were higher in patients compared to healthy people at any time of day. Conclusion We observed a marked circadian rhythmicity of temperature in patients with BVL, probably due to the influence of the light dark cycle. However, the lack of synchronization between the temperature and rest-activity cycle supports the hypothesis that the vestibular inputs are salient input to the circadian clock that enhance the stabilization and precision of both external and internal entrainment. PMID:27341473

  8. Prevalence of vestibular dysfunction and associated factors in South Korea

    PubMed Central

    Koo, Ja-Won; Chang, Mun Young; Woo, Sook-young; Kim, Seonwoo; Cho, Yang-Sun

    2015-01-01

    Objective To report the nationwide prevalence of dizziness and vestibular dysfunction in the Korean population and determine the associated factors. Design Cross-sectional analysis of a nationwide health survey. Methods We obtained data from the 2009 to 2010 Korea National Health and Nutrition Examination Surveys, which were cross-sectional surveys of the South Korean civilian, non-institutionalised population aged 40 years and older (N=3267). A field survey team performed interviews and physical examinations. Structured questionnaires were handed out and balance function tests using the modified Romberg test of standing balance on firm and compliant support surfaces were performed on participants. Failure on the modified Romberg test was regarded to indicate vestibular dysfunction. Results The prevalence of dizziness during the past year was 16.70% (95% CI 14.65% to 18.76%). The presence of vestibular dysfunction was noted in 1.84% (95% CI 1.18% to 2.51%). In addition, the prevalence of experiencing falls and positional dizziness were 1.46% (95% CI 0.87% to 2.06%) and 1.73% (95% CI 1.17% to 2.29%), respectively. Multivariable analysis revealed that dizziness was associated with increased age, female gender, hearing loss and stress. Vestibular dysfunction was associated with increased age, history of dizziness and hearing loss. Conclusions Vertigo and dizziness are the greatest contributors to the burden of disability in the aged population. Screening for dizziness and vestibular dysfunction, and management of associated factors might be important for improving compromised quality of life due to postural imbalance caused by vestibular problems. PMID:26503384

  9. Kv1 channels and neural processing in vestibular calyx afferents

    PubMed Central

    Meredith, Frances L.; Kirk, Matthew E.; Rennie, Katherine J.

    2015-01-01

    Potassium-selective ion channels are important for accurate transmission of signals from auditory and vestibular sensory end organs to their targets in the central nervous system. During different gravity conditions, astronauts experience altered input signals from the peripheral vestibular system resulting in sensorimotor dysfunction. Adaptation to altered sensory input occurs, but it is not explicitly known whether this involves synaptic modifications within the vestibular epithelia. Future investigations of such potential plasticity require a better understanding of the electrophysiological mechanisms underlying the known heterogeneity of afferent discharge under normal conditions. This study advances this understanding by examining the role of the Kv1 potassium channel family in mediating action potentials in specialized vestibular afferent calyx endings in the gerbil crista and utricle. Pharmacological agents selective for different sub-types of Kv1 channels were tested on membrane responses in whole cell recordings in the crista. Kv1 channels sensitive to α-dendrotoxin and dendrotoxin-K were found to prevail in the central regions, whereas K+ channels sensitive to margatoxin, which blocks Kv1.3 and 1.6 channels, were more prominent in peripheral regions. Margatoxin-sensitive currents showed voltage-dependent inactivation. Dendrotoxin-sensitive currents showed no inactivation and dampened excitability in calyces in central neuroepithelial regions. The differential distribution of Kv1 potassium channels in vestibular afferents supports their importance in accurately relaying gravitational and head movement signals through specialized lines to the central nervous system. Pharmacological modulation of specific groups of K+ channels could help alleviate vestibular dysfunction on earth and in space. PMID:26082693

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

    PubMed

    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

  11. Magnetic vestibular stimulation modulates default mode network fluctuations.

    PubMed

    Boegle, Rainer; Stephan, Thomas; Ertl, Matthias; Glasauer, Stefan; Dieterich, Marianne

    2016-02-15

    Strong magnetic fields (>1 Tesla) can cause dizziness and it was recently shown that healthy subjects (resting in total darkness) developed a persistent nystagmus even when remaining completely motionless within a MR tomograph. Consequently, it was speculated that this magnetic vestibular stimulation (MVS) might influence fMRI results, as nystagmus is indicative of an imbalance in the vestibular system, potentially influencing other systems via multisensory vestibular interactions. The objective of our study was to investigate whether MVS does indeed modulate BOLD signal fluctuations. We recorded eye movements, as well as, resting-state fMRI of 30 volunteers in darkness at 1.5 T and 3.0 T to answer the question whether MVS modulated parts of the default mode resting-state network (DMN) in accordance with the Lorentz-force model for MVS, while distinguishing this from the known signal increase due to field strength related imaging effects. Our results showed that modulation of the default mode network occurred mainly in areas associated with vestibular and ocular motor function, and was in accordance with the Lorentz-force model, i.e., double than the expected signal scaling due to field strength alone. We discuss the implications of our findings for the interpretation of studies using resting-state fMRI, especially those concerning vestibular research. We conclude that MVS needs to be considered in vestibular research to avoid biased results, but it might also offer the possibility of manipulating network dynamics and may thus help in studying the brain as a dynamical system. PMID:26666898

  12. Short latency vestibular evoked potentials in the chicken embryo

    NASA Technical Reports Server (NTRS)

    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 < 6.0 ms) were scored and latencies and amplitudes quantified. Vestibular response latencies were significantly longer (P < 0.01) and amplitudes significantly smaller (P < 0.001) than those observed in 2-week-old birds. Mean response threshold for anesthetized embryos was -15.9dBre 1.0 g/ms, which was significantly higher (P < 0.03) than those observed in 2-week-old birds (-23.0dBre 1.0 g/ms). Latency/intensity functions (that is, slopes) were not significantly different between embryos and 2-week-old animals, but amplitude/intensity functions for embryos were significantly shallower than those for 2-week-old birds (P < 0.001). We presume that these differences reflect the refinement of sensory function that occurs following 19 to 20 days of incubation. The recording of vestibular evoked potentials provides an objective, direct and noninvasive measure of peripheral vestibular function in the 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.

  13. Plasticity during Vestibular Compensation: The Role of Saccades

    PubMed Central

    MacDougall, Hamish Gavin; Curthoys, Ian S.

    2011-01-01

    This paper is focused on one major aspect of compensation: the recent measures of saccadic responses to high acceleration head turns during human vestibular compensation and their possible implications for recovery after unilateral vestibular loss (UVL). New measurement techniques have provided additional insights into how patients recover after UVL and have given clues for vestibular rehabilitation. Prior to this it has not been possible to quantify the level of function of all the 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 head movements with natural values of angular acceleration. The present evidence is that after UVL there is little or no restoration/compensation 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. Furthermore it may be possible to train patients to produce more effective saccadic patterns in the first days after their unilateral loss and possibly improve their compensation process. Some patients do learn new strategies, new behaviors, to conceal their inadequate vestibulo-ocular response but when those strategies are prevented from operating by using passive, unpredictable, high acceleration natural head movements, as in the head impulse test, the vestibular loss can be demonstrated. It is those very

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

    PubMed

    Cutfield, Nicholas J; Scott, Gregory; Waldman, Adam D; Sharp, David J; Bronstein, Adolfo M

    2014-01-01

    Following bilateral vestibular loss (BVL) patients gradually adapt to the loss of vestibular input and rely more on other sensory inputs. Here we examine changes in the way proprioceptive and visual inputs interact. We used functional magnetic resonance imaging (fMRI) to investigate visual responses in the context of varying levels of proprioceptive input in 12 BVL subjects and 15 normal controls. A novel metal-free vibrator was developed to allow vibrotactile neck proprioceptive input to be delivered in the MRI system. A high level (100 Hz) and low level (30 Hz) control stimulus was applied over the left splenius capitis; only the high frequency stimulus generates a significant proprioceptive stimulus. The neck stimulus was applied in combination with static and moving (optokinetic) visual stimuli, in a factorial fMRI experimental design. We found that high level neck proprioceptive input had more cortical effect on brain activity in the BVL patients. This included a reduction in visual motion responses during high levels of proprioceptive input and differential activation in the midline cerebellum. In early visual cortical areas, the effect of high proprioceptive input was present for both visual conditions but in lateral visual areas, including V5/MT, the effect was only seen in the context of visual motion stimulation. The finding of a cortical visuo-proprioceptive interaction in BVL patients is consistent with behavioural data indicating that, in BVL patients, neck afferents partly replace vestibular input during the CNS-mediated compensatory process. An fMRI cervico-visual interaction may thus substitute the known visuo-vestibular interaction reported in normal subject fMRI studies. The results provide evidence for a cortical mechanism of adaptation to vestibular failure, in the form of an enhanced proprioceptive influence on visual processing. The results may provide the basis for a cortical mechanism involved in proprioceptive substitution of vestibular

  15. Perceptual and Motor Inhibition in Individuals With Vestibular Disorders

    PubMed Central

    Mohammad, Maha T.; Whitney, Susan L.; Sparto, Patrick J.; Jennings, J. Richard; Furman, Joseph M.

    2016-01-01

    Background and Purpose Vestibular dysfunction has been shown to be associated with altered cognitive function. The purpose of this study was to examine changes in cognitive function in participants with vestibular disease during the course of vestibular physical therapy. Methods Twenty-two participants (mean age = 52, standard deviation = 11) with previously diagnosed vestibular disorders were tested at the beginning and end of rehabilitation. The Motor and Perceptual Inhibition Test (MAPIT) was used to assess manual reaction times when responding to various stimuli presented on a computer screen. Additional physical performance measures and questionnaires related to dizziness, fear of falling, and activities of daily living were used to quantify change during the 6-week intervention period. The repeatable battery for the assessment of neuropsychological status (a measure of memory and executive function) was used to ensure that participants did not have memory or executive function deficits. Results Overall, there were no significant differences in MAPIT score before versus after physical therapy intervention, however there were some participants who demonstrated improvements in motor inhibition (MI) and perceptual inhibition (PI) scores. Interstingly, 8 of the 9 participants with abnormal caloric test findings had improvements on 2 of the PI scores. Overall 50% to 64% of the participants demonstrated improvement in the 4 different MAPIT scores. There were improvements in physical performance and self-report measures at the end of the 6-week physical therapy intervention program. Discussion/Conclusion Individuals with vestibular disorders may show improvement in MI and PI after a 6-week physical therapy intervention program; those with abnormalities on caloric and rotational chair tests appear especially likely to experience improvement in PI. Additional study is needed to determine whether individuals with vestibular disorders have remediable deficits in MI and

  16. Motor Performance is Impaired Following Vestibular Stimulation in Ageing Mice

    PubMed Central

    Tung, Victoria W. K.; Burton, Thomas J.; Quail, Stephanie L.; Mathews, Miranda A.; Camp, Aaron J.

    2016-01-01

    Balance and maintaining postural equilibrium are important during stationary and dynamic movements to prevent falls, particularly in older adults. While our sense of balance is influenced by vestibular, proprioceptive, and visual information, this study focuses primarily on the vestibular component and its age-related effects on balance. C57Bl/6J mice of ages 1, 5–6, 8–9 and 27–28 months were tested using a combination of standard (such as grip strength and rotarod) and newly-developed behavioral tests (including balance beam and walking trajectory tests with a vestibular stimulus). In the current study, we confirm a decline in fore-limb grip strength and gross motor coordination as age increases. We also show that a vestibular stimulus of low frequency (2–3 Hz) and duration can lead to age-dependent changes in balance beam performance, which was evident by increases in latency to begin walking on the beam as well as the number of times hind-feet slip (FS) from the beam. Furthermore, aged mice (27–28 months) that received continuous access to a running wheel for 4 weeks did not improve when retested. Mice of ages 1, 10, 13 and 27–28 months were also tested for changes in walking trajectory as a result of the vestibular stimulus. While no linear relationship was observed between the changes in trajectory and age, 1-month-old mice were considerably less affected than mice of ages 10, 13 and 27–28 months. Conclusion: this study confirms there are age-related declines in grip strength and gross motor coordination. We also demonstrate age-dependent changes to finer motor abilities as a result of a low frequency and duration vestibular stimulus. These changes showed that while the ability to perform the balance beam task remained intact across all ages tested, behavioral changes in task performance were observed. PMID:26869921

  17. Visual and proprioceptive interaction in patients with bilateral vestibular loss☆

    PubMed Central

    Cutfield, Nicholas J.; Scott, Gregory; Waldman, Adam D.; Sharp, David J.; Bronstein, Adolfo M.

    2014-01-01

    Following bilateral vestibular loss (BVL) patients gradually adapt to the loss of vestibular input and rely more on other sensory inputs. Here we examine changes in the way proprioceptive and visual inputs interact. We used functional magnetic resonance imaging (fMRI) to investigate visual responses in the context of varying levels of proprioceptive input in 12 BVL subjects and 15 normal controls. A novel metal-free vibrator was developed to allow vibrotactile neck proprioceptive input to be delivered in the MRI system. A high level (100 Hz) and low level (30 Hz) control stimulus was applied over the left splenius capitis; only the high frequency stimulus generates a significant proprioceptive stimulus. The neck stimulus was applied in combination with static and moving (optokinetic) visual stimuli, in a factorial fMRI experimental design. We found that high level neck proprioceptive input had more cortical effect on brain activity in the BVL patients. This included a reduction in visual motion responses during high levels of proprioceptive input and differential activation in the midline cerebellum. In early visual cortical areas, the effect of high proprioceptive input was present for both visual conditions but in lateral visual areas, including V5/MT, the effect was only seen in the context of visual motion stimulation. The finding of a cortical visuo-proprioceptive interaction in BVL patients is consistent with behavioural data indicating that, in BVL patients, neck afferents partly replace vestibular input during the CNS-mediated compensatory process. An fMRI cervico-visual interaction may thus substitute the known visuo-vestibular interaction reported in normal subject fMRI studies. The results provide evidence for a cortical mechanism of adaptation to vestibular failure, in the form of an enhanced proprioceptive influence on visual processing. The results may provide the basis for a cortical mechanism involved in proprioceptive substitution of vestibular

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

    PubMed Central

    Pender, Daniel J

    2009-01-01

    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

  19. Sensitization as a Basic Principle of Vestibular Adaptation to Microgravity

    NASA Astrophysics Data System (ADS)

    Horn, Eberhard R.

    2008-06-01

    The analysis of basic mechanisms of physiological adaptation to weightlessness suffers (1) on the rare flight opportunities, and (2) on the collection of data with a rough time resolution. The comparative approach using data from animal and human research might be helpful to overcome these problems even for human research. The advantage of the comparative approach became obvious for vestibular adaptation to microgravity. Neuroanatomical, neurophysiological, behavioural and psychophysical studies in snails, fish, amphibian, rodents, monkey and men clearly revealed vestibular sensitization as a basic mechanism of adaptation to weightlessness.

  20. Ernst Mach on the vestibular organ 100 years ago.

    PubMed

    Henn, V; Young, L R

    1975-01-01

    Ernst Mach (1838-1916) performed pioneering research on vestibular function 100 years ago. His experiments were mainly psychophysical and included measurements of threshold and study of the vestibular-visual interaction. Contrary to general belief, he concluded that the adequate stimulus for the semicircular canals must be pressure. He presented evidence specifically against the sustained endolymph flow theory of Breuer (1874) and Crum Brown (1874), with which he is frequently associated. Excerpts from his publications are given and their relevance to current research is discussed. PMID:1093083

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

    NASA Technical Reports Server (NTRS)

    Ross, M. D.; Bourne, C.

    1983-01-01

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

  2. N-acetyl-L-leucine accelerates vestibular compensation after unilateral labyrinthectomy by action in the cerebellum and thalamus.

    PubMed

    Günther, Lisa; Beck, Roswitha; Xiong, Guoming; Potschka, Heidrun; Jahn, Klaus; Bartenstein, Peter; Brandt, Thomas; Dutia, Mayank; Dieterich, Marianne; Strupp, Michael; la Fougère, Christian; Zwergal, Andreas

    2015-01-01

    An acute unilateral vestibular lesion leads to a vestibular tone imbalance with nystagmus, head roll tilt and postural imbalance. These deficits gradually decrease over days to weeks due to central vestibular compensation (VC). This study investigated the effects of i.v. N-acetyl-DL-leucine, N-acetyl-L-leucine and N-acetyl-D-leucine on VC using behavioural testing and serial [18F]-Fluoro-desoxyglucose ([18F]-FDG)-μPET in a rat model of unilateral chemical labyrinthectomy (UL). Vestibular behavioural testing included measurements of nystagmus, head roll tilt and postural imbalance as well as sequential whole-brain [18F]-FDG-μPET was done before and on days 1,3,7 and 15 after UL. A significant reduction of postural imbalance scores was identified on day 7 in the N-acetyl-DL-leucine (p < 0.03) and the N-acetyl-L-leucine groups (p < 0.01), compared to the sham treatment group, but not in the N-acetyl-D-leucine group (comparison for applied dose of 24 mg i.v. per rat, equivalent to 60 mg/kg body weight, in each group). The course of postural compensation in the DL- and L-group was accelerated by about 6 days relative to controls. The effect of N-acetyl-L-leucine on postural compensation depended on the dose: in contrast to 60 mg/kg, doses of 15 mg/kg and 3.75 mg/kg had no significant effect. N-acetyl-L-leucine did not change the compensation of nystagmus or head roll tilt at any dose. Measurements of the regional cerebral glucose metabolism (rCGM) by means of μPET revealed that only N-acetyl-L-leucine but not N-acetyl-D-leucine caused a significant increase of rCGM in the vestibulocerebellum and a decrease in the posterolateral thalamus and subthalamic region on days 3 and 7. A similar pattern was found when comparing the effect of N-acetyl-L-leucine on rCGM in an UL-group and a sham UL-group without vestibular damage. In conclusion, N-acetyl-L-leucine improves compensation of postural symptoms after UL in a dose-dependent and specific manner, most likely by

  3. N-Acetyl-L-Leucine Accelerates Vestibular Compensation after Unilateral Labyrinthectomy by Action in the Cerebellum and Thalamus

    PubMed Central

    Xiong, Guoming; Potschka, Heidrun; Jahn, Klaus; Bartenstein, Peter; Brandt, Thomas; Dutia, Mayank; Dieterich, Marianne; Strupp, Michael; la Fougère, Christian; Zwergal, Andreas

    2015-01-01

    An acute unilateral vestibular lesion leads to a vestibular tone imbalance with nystagmus, head roll tilt and postural imbalance. These deficits gradually decrease over days to weeks due to central vestibular compensation (VC). This study investigated the effects of i.v. N-acetyl-DL-leucine, N-acetyl-L-leucine and N-acetyl-D-leucine on VC using behavioural testing and serial [18F]-Fluoro-desoxyglucose ([18F]-FDG)-μPET in a rat model of unilateral chemical labyrinthectomy (UL). Vestibular behavioural testing included measurements of nystagmus, head roll tilt and postural imbalance as well as sequential whole-brain [18F]-FDG-μPET was done before and on days 1,3,7 and 15 after UL. A significant reduction of postural imbalance scores was identified on day 7 in the N-acetyl-DL-leucine (p < 0.03) and the N-acetyl-L-leucine groups (p < 0.01), compared to the sham treatment group, but not in the N-acetyl-D-leucine group (comparison for applied dose of 24 mg i.v. per rat, equivalent to 60 mg/kg body weight, in each group). The course of postural compensation in the DL- and L-group was accelerated by about 6 days relative to controls. The effect of N-acetyl-L-leucine on postural compensation depended on the dose: in contrast to 60 mg/kg, doses of 15 mg/kg and 3.75 mg/kg had no significant effect. N-acetyl-L-leucine did not change the compensation of nystagmus or head roll tilt at any dose. Measurements of the regional cerebral glucose metabolism (rCGM) by means of μPET revealed that only N-acetyl-L-leucine but not N-acetyl-D-leucine caused a significant increase of rCGM in the vestibulocerebellum and a decrease in the posterolateral thalamus and subthalamic region on days 3 and 7. A similar pattern was found when comparing the effect of N-acetyl-L-leucine on rCGM in an UL-group and a sham UL-group without vestibular damage. In conclusion, N-acetyl-L-leucine improves compensation of postural symptoms after UL in a dose-dependent and specific manner, most likely by

  4. Surgical outcome in cystic vestibular schwannomas

    PubMed Central

    Nair, Suresh; Baldawa, Sachin S.; Gopalakrishnan, Chittur Viswanathan; Menon, Girish; Vikas, Vazhayil; Sudhir, Jayanand B.

    2016-01-01

    Background: Cystic vestibular schwannomas (VS) form a rare subgroup that differs from the solid variant clinically, radiologically, and histopathologically. These tumors also vary in their surgical outcome and carry a different risk of post-operative complications. We analyzed our series of 64 patients with cystic VS and discuss the technical difficulties related to total excision of these tumors and focus on complication avoidance. Materials and Methods: A retrospective review of cystic VS surgically managed over a span of 11 years. The case records were evaluated to record the clinical symptoms and signs, imaging findings, surgical procedure, complications, and follow-up data. Post-operative facial nerve palsy was analyzed with respect to tumor size and tumor type. Results: Progressive hearing impairment was the most common initial symptom (76.6%). Atypical initial symptoms were present in 15 patients (23.4%). Preoperatively, 78% patients had good facial nerve function (HB grade 1, 2) and 22% had intermediate (HB grade 3, 4) to poor (HB grade 5 and 6) function. Mean tumor size was 4.1 cm. Complete tumor removal was achieved in 53 patients (83%). The facial nerve was anatomically intact but thinned out after tumor excision in 38 patients (59.4%). Ninety percent patients had either intermediate or poor facial nerve function at follow-up. Poor facial nerve outcome was associated with giant tumors and peripherally located, thin-walled cystic tumors. Conclusion: Resection of cystic VS is complicated by peritumoral adhesions of the capsule to the nerve. Extensive manipulation of the nerve in order to dissect the tumor–nerve barrier results in worse facial nerve outcome. The outcome is worse in peripherally located, thin-walled cystic VS as compared to centrally located, thick-walled cystic tumors. Subtotal excision may be justified, especially in tumors with dense adhesion of the cyst wall to the facial nerve in order to preserve nerve integrity. PMID:27366248

  5. Repeat Gamma Knife surgery for vestibular schwannomas

    PubMed Central

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

    PubMed

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

    2016-01-15

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

  7. Nobel Prize centenary: Robert Bárány and the vestibular system.

    PubMed

    Lopez, Christophe; Blanke, Olaf

    2014-11-01

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

  8. Vestibular Compensation in Unilateral Patients Often Causes Both Gain and Time Constant Asymmetries in the VOR

    PubMed Central

    Ranjbaran, Mina; Katsarkas, Athanasios; Galiana, Henrietta L.

    2016-01-01

    The vestibulo-ocular reflex (VOR) is essential in our daily life to stabilize retinal images during head movements. Balanced vestibular functionality secures optimal reflex performance which otherwise can be distorted by peripheral vestibular lesions. Luckily, vestibular compensation in different neuronal sites restores VOR function to some extent over time. Studying vestibular compensation gives insight into the possible mechanisms for plasticity in the brain. In this work, novel experimental analysis tools are employed to reevaluate the VOR characteristics following unilateral vestibular lesions and compensation. Our results suggest that following vestibular lesions, asymmetric performance of the VOR is not only limited to its gain. Vestibular compensation also causes asymmetric dynamics, i.e., different time constants for the VOR during leftward or rightward passive head rotation. Potential mechanisms for these experimental observations are provided using simulation studies. PMID:27065839

  9. Vestibular Compensation in Unilateral Patients Often Causes Both Gain and Time Constant Asymmetries in the VOR.

    PubMed

    Ranjbaran, Mina; Katsarkas, Athanasios; Galiana, Henrietta L

    2016-01-01

    The vestibulo-ocular reflex (VOR) is essential in our daily life to stabilize retinal images during head movements. Balanced vestibular functionality secures optimal reflex performance which otherwise can be distorted by peripheral vestibular lesions. Luckily, vestibular compensation in different neuronal sites restores VOR function to some extent over time. Studying vestibular compensation gives insight into the possible mechanisms for plasticity in the brain. In this work, novel experimental analysis tools are employed to reevaluate the VOR characteristics following unilateral vestibular lesions and compensation. Our results suggest that following vestibular lesions, asymmetric performance of the VOR is not only limited to its gain. Vestibular compensation also causes asymmetric dynamics, i.e., different time constants for the VOR during leftward or rightward passive head rotation. Potential mechanisms for these experimental observations are provided using simulation studies. PMID:27065839

  10. Significance of Vestibular Testing on Distinguishing the Nerve of Origin for Vestibular Schwannoma and Predicting the Preservation of Hearing

    PubMed Central

    He, Yu-Bo; Yu, Chun-Jiang; Ji, Hong-Ming; Qu, Yan-Ming; Chen, Ning

    2016-01-01

    Background: Determining the nerve of origin for vestibular schwannoma (VS), as a method for predicting hearing prognosis, has not been systematically considered. The vestibular test can be used to investigate the function of the superior vestibular nerve (SVN) and the inferior vestibular nerve (IVN). This study aimed to preoperatively distinguish the nerve of origin for VS patients using the vestibular test, and determine if this correlated with hearing preservation. Methods: A total of 106 patients with unilateral VS were enrolled in this study prospectively. Each patient received a caloric test, vestibular-evoked myogenic potential (VEMP) test, and cochlear nerve function test (hearing) before the operation and 1 week, 3, and 6 months, postoperatively. All patients underwent surgical removal of the VS using the suboccipital approach. During the operation, the nerve of tumor origin (SVN or IVN) was identified by the surgeon. Tumor size was measured by preoperative magnetic resonance imaging. Results: The nerve of tumor origin could not be unequivocally identified in 38 patients (38/106, 35.80%). These patients were not subsequently evaluated. In 26 patients (nine females, seventeen males), tumors arose from the SVN and in 42 patients (18 females, 24 males), tumors arose from the IVN. Comparing with the nerve of origins (SVN and IVN) of tumors, the results of the caloric tests and VEMP tests were significantly different in tumors originating from the SVN and the IVN in our study. Hearing was preserved in 16 of 26 patients (61.54%) with SVN-originating tumors, whereas hearing was preserved in only seven of 42 patients (16.67%) with IVN-originating tumors. Conclusions: Our data suggest that caloric and VEMP tests might help to identify whether VS tumors originate from the SVN or IVN. These tests could also be used to evaluate the residual function of the nerves after surgery. Using this information, we might better predict the preservation of hearing for patients

  11. Optic neuritis and rapidly progressive necrotizing retinitis as the initial signs of subacute sclerosing panencephalitis: a case report with clinical and histopathologic findings.

    PubMed

    Oray, Merih; Tuncer, Samuray; Kir, Nur; Karacorlu, Murat; Tugal-Tutkun, Ilknur

    2014-08-01

    We report a case of subacute sclerosing panencephalitis (SSPE) presenting first with optic neuritis and rapidly progressive necrotizing retinitis at the posterior pole. We reviewed the clinical, laboratory, photographic, angiographic, and histopathologic records of a patient with SSPE. A 15-year-old girl was referred after rapid loss of vision due to optic neuritis and macular necrosis in the right eye. She had a history of cardiac valve surgery, but had no systemic symptoms and extensive work-up was unrewarding. Contralateral involvement with rapidly progressive optic neuritis and macular necrotizing retinitis prompted retinochoroidal biopsy of the right eye, which revealed necrosis of inner retinal layers and perivascular lymphoplasmocytic infiltration with intact choroid and outer retina without any findings of inclusion bodies, microorganisms, or atypical cells. The diagnosis was based on histopathologic findings consistent with SSPE, and detection of elevated measles antibody titers in cerebrospinal fluid and serum. It was further confirmed by development of typical electroencephalography pattern at 6 months and neurological symptoms at 4-year follow-up. Clinicians need to be aware that optic neuritis and necrotizing retinitis at the posterior pole may be the presenting features of SSPE. PMID:24522882

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

    PubMed

    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-β1 (TGF-β1) interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α), 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-β1, IL-1β and IL-6 exhibited increased expression in human vestibular schwannoma tissue compared with normal vestibular nerve samples. TNF-α 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

  13. Frequency of Autoantibodies and Connective Tissue Diseases in Chinese Patients with Optic Neuritis

    PubMed Central

    Yi, Zuohuizi; Huang, Dehui; Wei, Shihui

    2014-01-01

    Background Optic neuritis (ON) is often associated with other clinical or serological markers of connective tissue diseases (CTDs). To date, the effects of autoantibodies on ON are not clear. Purpose To assess the prevalence, clinical patterns, and short outcomes of autoantibodies and Sjögren’s syndrome (SS) involvement in Chinese ON patients and evaluate the relationship between ON, including their subtypes, and autoantibodies. Methods A total of 190 ON patients were divided into recurrent ON (RON), bilateral ON (BON), and isolated monocular ON (ION). Demographic, clinical, and serum autoantibodies data were compared between them with and without SS involvement. Serum was drawn for antinuclear antibody (ANA), extractable nuclear antigen antibodies (SSA/SSB), rheumatoid factor (RF), anticardiolipin antibodies (ACA), and anti-double-stranded DNA antibody (A-ds DNA), anticardiolipin antibody (ACLs), anti-β2-glycoprotein I (β2-GPI) and Aquaporin-4 antibodies (AQP4-Ab). Spectral-domain optical coherence tomography (SD-OCT) was used to evaluate the atrophy of the optic nerve. Results 68 patients (35.79%) had abnormal autoantibodies, 26(13.68%) patients met diagnostic criteria for CTDs, including 15(7.89%) patients meeting the criteria for SS. Antibodies including SSA/SSB 23 (30.26%) (p1 and p 2<0.001) and AQP4–Ab10 (13.16%) (p1 = 0.044, p2 = 0.01) were significantly different in patients in the RON group when compared with those in the BON (P1 = RON VS ION) and ION (p2 = RON VS ION) groups. SS was more common in RON patients (p1 = 0.04, p2 = 0.028). There was no significant difference between SSA/SSB positive and negative patients in disease characteristics or severity. Similar results were obtained when SS was diagnosed in SSA/SSB positive patients. Conclusion RON and BON were more likely associated with abnormal autoantibodies; furthermore, AQP4 antibody, SSA/SSB and SS were more common in the RON patients. AQP4 antibodydetermination is

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

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

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

  15. Towards a concept of disorders of “higher vestibular function”

    PubMed Central

    Brandt, Thomas; Strupp, Michael; Dieterich, Marianne

    2014-01-01

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

  16. Static Balance in Patients with Vestibular Impairments: A Preliminary Study.

    PubMed

    Talebi, Hossein; Karimi, Mohammad Taghi; Abtahi, Seyed Hamid Reza; Fereshtenejad, Niloofar

    2016-01-01

    Aims. Vestibular system is indicated as one of the most important sensors responsible for static and dynamic postural control. In this study, we evaluated static balance in patients with unilateral vestibular impairments. Materials and Methods. We compared static balance control using Kistler force plate platform between 10 patients with unilateral vestibular impairments and 20 normal counterparts in the same sex ratio and age limits (50 ± 7). We evaluated excursion and velocity of center of pressure (COP) and path length in anteroposterior (AP) and mediolateral (ML) planes with eyes open and with eyes closed. Results. There was no significant difference between COP excursions in ML and AP planes between both groups with eyes open and eyes closed (p value > 0.05). In contrast, the difference between velocity and path length of COP in the mentioned planes was significant between both groups with eyes open and eyes closed (p value < 0.05). Conclusions. The present study showed the static instability and balance of patients with vestibular impairments indicated by the abnormal characteristics of body balance. PMID:27379198

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

    ERIC Educational Resources Information Center

    Neal, Mary V.

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

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

    PubMed

    Wang, Joanne; Lewis, Richard F

    2016-06-01

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

  19. Vestibular dehiscence syndrome caused by a labyrinthine congenital cholesteatoma.

    PubMed

    Fiorino, Francesco; Pizzini, Francesca B; Mattellini, Barbara; Barbieri, Franco

    2015-02-01

    A 40-year-old man presented with conductive hearing loss and pressure- and sound-related vestibular symptoms. Computed tomography and diffusion-weighted magnetic resonance imaging revealed the presence of a cholesteatoma involving the vestibular labyrinth. The patient underwent a canal-wall-up tympanoplasty, which revealed evidence of a disruption of the vestibular labyrinth and a wide dehiscence of the vestibule, which was immediately resurfaced. At the 2-month follow-up, the patient's pressure- and sound-related vestibular symptoms had disappeared. Pure-tone audiometry showed a reduction in the air-bone gap with a slight deterioration of bone conduction and an improvement in the air-conduction threshold. Fistulization of the otic capsule produces a "third window," which can lead to a dehiscence syndrome. One possible cause is a cholesteatoma of the middle ear or petrous bone. When the vestibule is invaded by a cholesteatoma, hearing is almost invariably lost, either pre- or postoperatively. However, in our case, wide opening of the vestibule resulted in hearing preservation. PMID:25651351

  20. Tests of walking balance for screening vestibular disorders

    PubMed Central

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

    2013-01-01

    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 weakness, and post-acoustic neuroma resection. We compared them to normal subjects. All subjects were independently ambulatory without gait aids. Subjects were tested on tandem walking (TW) with eyes open and eyes closed for 10 steps, walking with no additional head motions and with augmented head rotations in yaw for 7 m (WwHT), and an obstacle avoidance task, the Functional Mobility Test (FMT). Subjects wore a 3-D motion sensor centered at mid-torso to capture kinematic measures. Patients and normals differed significantly on some behavioral measures, such as the number of steps to perform TW, and on some but not all kinematic measures. ROC analyses, however, were at best only moderate, and failed to find strong differences and cut-points that would differentiate the groups. These findings suggest that although patients and normals differ in performance of these tests in some interesting ways the groups are not sufficiently different on these tests for easy use as screening tests to differentiate the populations. PMID:23000609

  1. Astronauts Conrad and Kerwin practice Human Vestibular Function experiment

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Astronaut Charles Conrad Jr., commander of the first manned Skylab mission, checks out the Human Vestibular Function, Experiment M131, during Skylab training at JSC. Scientist-Astronaut Joseph P. Kerwin, science pilot of the mission, goes over a checklist. The two men are in the work and experiments compartment of the crew quarters of the Skylab Orbital Workshop (OWS) trainer at JSC.

  2. The Development of Vestibular Connections in Rat Embryos in Microgravity

    NASA Technical Reports Server (NTRS)

    Bruce, Laura L.; Fritzsch, Bernd

    1997-01-01

    Existing experimental embryological data suggests that the vestibular system initially develops in a very rigid and genetically controlled manner. Nevertheless, gravity appears to be a critical factor in the normal development of the vestibular system that monitors position with respect to gravity (saccule and utricle). In fact several studies have shown that prenatal exposure to microgravity causes temporary deficits in gravity-dependent righting behaviors, and prolonged exposure to hypergravity from conception to weaning causes permanent deficits in gravity-dependent righting behaviors. Data on hypergravity and microgravity exposure suggest some changes in the otolith formation during development, in particular the size although these changes may actually vary with the species involved. In adults exposed to microgravity there is a change in the synaptic density in the otic sensory epithelia suggesting that some adaptation may occur there. However, effects have also been reported in the brainstem. Several studies have shown synaptic changes in the lateral vestibular nucleus and in the nodulus of the cerebellum after neonatal exposure to hypergravity. We report here that synaptogenesis in the medial vestibular nucleus is retarded in developing rat embryos that were exposed to microgravity from gestation days 9 to 19.

  3. Hippocampal gray matter volume in bilateral vestibular failure.

    PubMed

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

    2016-05-01

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

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

    NASA Technical Reports Server (NTRS)

    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.

  5. Complex vestibular macular anatomical relationships need a synthetic approach

    NASA Technical Reports Server (NTRS)

    Ross, M. D.

    2001-01-01

    Mammalian vestibular maculae are anatomically organized for complex parallel processing of linear acceleration information. Anatomical findings in rat maculae are provided in order to underscore this complexity, which is little understood functionally. This report emphasizes that a synthetic approach is critical to understanding how maculae function and the kind of information they conduct to the brain.

  6. Tests of walking balance for screening vestibular disorders.

    PubMed

    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 weakness, and post-acoustic neuroma resection. We compared them to normal subjects. All subjects were independently ambulatory without gait aids. Subjects were tested on tandem walking (TW) with eyes open and eyes closed for 10 steps, walking with no additional head motions and with augmented head rotations in yaw for 7 m (WwHT), and an obstacle avoidance task, the Functional Mobility Test (FMT). Subjects wore a 3-D motion sensor centered at mid-torso to capture kinematic measures. Patients and normals differed significantly on some behavioral measures, such as the number of steps to perform TW, and on some but not all kinematic measures. ROC analyses, however, were at best only moderate, and failed to find strong differences and cut-points that would differentiate the groups. These findings suggest that although patients and normals differ in performance of these tests in some interesting ways the groups are not sufficiently different on these tests for easy use as screening tests to differentiate the populations. PMID:23000609

  7. Gaze stabilization and gait performance in vestibular dysfunction

    PubMed Central

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

    2016-01-01

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

  8. Static Balance in Patients with Vestibular Impairments: A Preliminary Study

    PubMed Central

    Talebi, Hossein; Abtahi, Seyed Hamid Reza; Fereshtenejad, Niloofar

    2016-01-01

    Aims. Vestibular system is indicated as one of the most important sensors responsible for static and dynamic postural control. In this study, we evaluated static balance in patients with unilateral vestibular impairments. Materials and Methods. We compared static balance control using Kistler force plate platform between 10 patients with unilateral vestibular impairments and 20 normal counterparts in the same sex ratio and age limits (50 ± 7). We evaluated excursion and velocity of center of pressure (COP) and path length in anteroposterior (AP) and mediolateral (ML) planes with eyes open and with eyes closed. Results. There was no significant difference between COP excursions in ML and AP planes between both groups with eyes open and eyes closed (p value > 0.05). In contrast, the difference between velocity and path length of COP in the mentioned planes was significant between both groups with eyes open and eyes closed (p value < 0.05). Conclusions. The present study showed the static instability and balance of patients with vestibular impairments indicated by the abnormal characteristics of body balance. PMID:27379198

  9. Current concepts and future approaches to vestibular rehabilitation.

    PubMed

    Tjernström, Fredrik; Zur, Oz; Jahn, Klaus

    2016-04-01

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

  10. Update on the pharmacotherapy of cerebellar and central vestibular disorders.

    PubMed

    Kalla, Roger; Teufel, Julian; Feil, Katharina; Muth, Caroline; Strupp, Michael

    2016-04-01

    An overview of the current pharmacotherapy of central vestibular syndromes and the most common forms of central nystagmus as well as cerebellar disorders is given. 4-aminopyridine (4-AP) is recommended for the treatment of downbeat nystagmus, a frequent form of acquired persisting fixation nystagmus, and upbeat nystagmus. Animal studies showed that this non-selective blocker of voltage-gated potassium channels increases Purkinje cell excitability and normalizes the irregular firing rate, so that the inhibitory influence of the cerebellar cortex on vestibular and deep cerebellar nuclei is restored. The efficacy of 4-AP in episodic ataxia type 2, which is most often caused by mutations of the PQ-calcium channel, was demonstrated in a randomized controlled trial. It was also shown in an animal model (the tottering mouse) of episodic ataxia type 2. In a case series, chlorzoxazone, a non-selective activator of small-conductance calcium-activated potassium channels, was shown to reduce the DBN. The efficacy of acetyl-DL-leucine as a potential new symptomatic treatment for cerebellar diseases has been demonstrated in three case series. The ongoing randomized controlled trials on episodic ataxia type 2 (sustained-release form of 4-aminopyridine vs. acetazolamide vs. placebo; EAT2TREAT), vestibular migraine with metoprolol (PROVEMIG-trial), cerebellar gait disorders (sustained-release form of 4-aminopyridine vs. placebo; FACEG) and cerebellar ataxia (acetyl-DL-leucine vs. placebo; ALCAT) will provide new insights into the pharmacotherapy of cerebellar and central vestibular disorders. PMID:27083881

  11. Mechanisms for vestibular disorders in space flight. Facts and hypotheses

    NASA Technical Reports Server (NTRS)

    Matsnev, E. I.

    1980-01-01

    This article discusses the vestibular disorders associated with space flight. It is found there is still no complete understanding of the changes occurring in the sensory systems of the body during weightlessness. Results of studies are presented, including results of a ground model.

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

    NASA Technical Reports Server (NTRS)

    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.

  13. B7-H1 Expression in Vestibular Schwannomas

    PubMed Central

    Archibald, David J.; Neff, Brian A.; Voss, Stephen G.; Splinter, Patrick L.; Driscoll, Colin L. W.; Link, Michael J.; Dong, Haidong; Kwon, Eugene D.

    2014-01-01

    Hypothesis B7-H1 is expressed in vestibular schwannomas. Background Little is known about how benign human vestibular schwannomas interact with antibody-mediated or cell-mediated immunity. We report on the aberrant expression of a novel T-cell coregulatory molecule, B7 homolog 1 (B7-H1), in vestibular schwannomas and discuss the implications of B7-H1 expression and tumor aggressiveness and a potential regulator of B7-H1 expression. Methods Immunohistochemical staining for B7-H1, CD8+, CD3+, and CD4+ lymphocytes were performed on 48 fresh-frozen vestibular schwannoma tissue specimens. A clinical review of patient presenting symptoms and tumor characteristics was performed. Real-time polymerase chain reaction was used to determine if there was differential expression of B7-H1 messenger RNA and microRNA-513, a known regulator of B7-H1, in several strongly positive and negative B7-H1 vestibular schwannomas. Results Nine (19%) of 48 tumors were negative, 23 (48%) tumors were 1+ mildly positive (<20% section area), and 16 (33%) stained 2+ strongly positive (≥20% section area) for B7-H1. The average number of CD8+ cells per high-power field was 2.1 for positive-staining tumors and 1.0 for negative tumors (p = 0.16). Failure of tumor control with stereotactic radiation (p = 0.029) was significantly greater in the strongly positive B7-H1 tumors. Real-time polymerase chain reaction did not show significant differential expression of microRNA-513 (p = 0.62) or B7-H1 messenger RNA (p = 0.35) between the tumors showing strong and negative immunohistochemical staining for B7-H1 protein. Conclusion Vestibular schwannoma tumors express B7-H1, which has been associated with immune tolerance and adverse disease characteristics in several malignancies. Growing tumors that were surgically removed after failed stereotactic radiation therapy were significantly more likely to strongly express B7-H1 protein, which lends some credibility to the hypothesis that immuno-evasion may play

  14. Vestibular factors influencing the biomedical support of humans in space

    NASA Astrophysics Data System (ADS)

    Lichtenberg, Byron K.

    This paper will describe the biomedical support aspects of humans in space with respect to the vestibular system. The vestibular system is thought to be the primary sensory system involved in the short-term effects of space motion sickness although there is increasing evidence that many factors play a role in this complex set of symptoms. There is the possibility that an individual's inner sense of orientation may be strongly coupled with the susceptibility to space motion sickness. A variety of suggested countermeasures for space motion sickness will be described. Although there are no known ground-based tests that can predict space motion sickness, the search should go on. The long term effects of the vestibular system in weightlessness are still relatively unknown. Some preliminary data has shown that the otoconia are irregular in size and distribution following extended periods of weightlessness. The ramifications of this data are not yet known and because the data was obtained on lower order animals, definitive studies and results must wait until the space station era when higher primates can be studied for long durations. This leads us to artificial gravity, the last topic of this paper. The vestibular system is intimately tied to this question since it has been shown on Earth that exposure to a slow rotating room causes motion sickness for some period of time before adaptation occurs. If the artificial gravity is intermittent, will this mean that people will get sick every time they experience it? The data from many astronauts returning to Earth indicates that a variety of sensory illusions are present, especially immediately upon return to a 1- g environment. Oscillopsia or apparent motion of the visual surround upon head motion along with inappropriate eye motions for a given head motion, all indicate that there is much to be studied yet about the vestibular and CNS systems reaction to a sudden application of a steady state acceleration field like 1- g

  15. Vestibular factors influencing the biomedical support of humans in space

    NASA Technical Reports Server (NTRS)

    Lichtenberg, B. K.

    1988-01-01

    This paper will describe the biomedical support aspects of humans in space with respect to the vestibular system. The vestibular system is thought to be the primary sensory system involved in the short-term effects of space motion sickness although there is increasing evidence that many factors play a role in this complex set of symptoms. There is the possibility that an individual's inner sense of orientation may be strongly coupled with the susceptibility to space motion sickness. A variety of suggested countermeasures for space motion sickness will be described. Although there are no known ground-based tests that can predict space motion sickness, the search should go on. The long term effects of the vestibular system in weightlessness are still relatively unknown. Some preliminary data has shown that the otoconia are irregular in size and distribution following extended periods of weightlessness. The ramifications of this data are not yet known and because the data was obtained on lower order animals, definitive studies and results must wait until the space station era when higher primates can be studied for long durations. This leads us to artificial gravity, the last topic of this paper. The vestibular system is intimately tied to this question since it has been shown on Earth that exposure to a slow rotating room causes motion sickness for some period of time before adaptation occurs. If the artificial gravity is intermittent, will this mean that people will get sick every time they experience it? The data from many astronauts returning to Earth indicates that a variety of sensory illusions are present, especially immediately upon return to a 1-g environment. Oscillopsia or apparent motion of the visual surround upon head motion along with inappropriate eye motions for a given head motion, all indicate that there is much to be studied yet about the vestibular and CNS systems reaction to a sudden application of a steady state acceleration field like 1-g. From

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

    PubMed

    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

  17. Spatial orientation of the vestibular system

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

    1. A simplified three-dimensional state space model of visual vestibular interaction was formulated. Matrix and dynamical system operators representing coupling from the semicircular canals and the visual system to the velocity storage integrator were incorporated into the model. 2. It was postulated that the system matrix for a tilted position was a composition of two linear transformations of the system matrix for the upright position. One transformation modifies the eigenvalues of the system matrix while another rotates the pitch and roll eigenvectors with the head, while maintaining the yaw axis eigenvector approximately spatially invariant. Using this representation, the response characteristics of the pitch, roll, and yaw eye velocity were obtained in terms of the eigenvalues and associated eigenvectors. 3. Using OKAN data obtained from monkeys and comparing to the model predictions, the eigenvalues and eigenvectors of the system matrix were identified as a function of tilt to the side or of tilt to the prone positions, using a modification of the Marquardt algorithm. The yaw eigenvector for right-side-down tilt and for downward pitch cross-coupling was approximately 30 degrees from the spatial vertical. For the prone position, the eigenvector was computed to be approximately 20 degrees relative to the spatial vertical. For both side-down and prone positions, oblique OKN induced along eigenvector directions generated OKAN which decayed to zero along a straight line with approximately a single time constant. This was verified by a spectral analysis of the residual sequence about the straight line fit to the decaying data. The residual sequence was associated with a narrow autocorrelation function and a wide power spectrum. 4. Parameters found using the Marquardt algorithm were incorporated into the model. Diagonal matrices in a head coordinate frame were introduced to represent the direct pathway and the coupling of the visual system to the integrator. Model

  18. The outermost “dura-like membrane” of vestibular schwannoma

    PubMed Central

    Tomio, Ryosuke; Yoshida, Kazunari; Kohno, Maya; Kamamoto, Dai; Mikami, Shuji

    2016-01-01

    Background: The membranous structure of vestibular schwannoma is an important factor in its surgical treatment. Herein, we report intraoperative and microscopic findings relating to an outermost dura-like membrane in cases of vestibular schwannoma and the importance of these findings. Methods: Intraoperative findings of 16 cases of vestibular schwannoma treated with an initial surgery were studied with an aim to determine if the cases had a dura-like membrane. Then we studied microscopic findings of the dura-like membrane using hematoxylin and eosin, Masson trichrome, and immunohistochemical staining in 2 cases. Results: The dura-like membrane was observed in 8 out of 16 cases. The average tumor size of the cases that had a dura-like membrane was 30 ± 8.1 mm, and Koos grading 4 was in 7 out of 8 cases, and one was grade 3. In cases without a dura-like membrane, these values were significantly smaller, with an average tumor size of 12.8 ± 5.2 mm, and Koos grading 4 was only in 1 of 8 cases, grade 3 was in 2 cases, and other 5 cases were grade 2. The outermost dura-like membrane enveloped the vestibular schwannoma around the internal acoustic meatus and was continuous with the dura mater. Reactive angiogenesis was observed in the dura mater. Microscopic findings proved its continuity with the dura mater. In one case, the facial nerve was damaged before it was identified during subcapsular dissection. In that case, the dura-like membrane negatively affected our ability to identify the facial nerve. Conclusions: A dura-like membrane sometimes envelops vestibular schwannoma around the internal acoustic meatus. Recognition of this membranous structure is important for the surgical preservation of facial and acoustic nerves. PMID:27453796

  19. [BEHAVIOURAL AND FUNCTIONAL VESTIBULAR DISTURBANCES AFTER SPACE FLIGHT. 1. MAMMALS].

    PubMed

    Lychakov, D V

    2015-01-01

    The review contains data on functional changes in mammals caused by changes in the operation of vestibular system after space flight. These data show that the vestibular system of mammals responds to weightlessness challenge differently at various ontogenetic stages. Orbital space flight conditions have a weak effect on the developing vestibular system during embryonic period. The weightlessness conditions have rather beneficial effect on development of the fetuses. During the early postnatal period, when optimal sensory-motor tactics are created, the prolonged stay under conditions of space flight leads to development of novel, "extraterrestrial" sensory-motor programs that can be fixed in CNS, apparently, for the whole life. In adult individuals after landing essential vestibular changes and disturbances may occur that depend on the spaceflight duration. The adult organism must simultaneously solve two contradicting problems--it should adapt to weightlessness conditions, and should not adapt to them to pass the process of readaptation after returning easier. Thus, individuals must protect themselves against weightlessness influence to keep the intact initial state of health. The protection methods against weightlessness ought to be adjusted according to the duration of space flight. It should be mentioned that not all functional changes registered in adult individuals after landing can be adequately explained. Some of these changes may have chronic or even pathological character. The question of necessity to examine the influence of weightlessness on an aging (senile) organism and on its vestibular system is raised for the first time in this review. In our opinion the development of space gerontology, as a special branch of space biology and medicine, is of undoubted interest, and in the future it may be of practical importance especially taking into account the steadily growing age of cosmonauts (astronauts). PMID:26983274

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

    PubMed

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

    2016-04-01

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

  1. Inhibition of K+ currents in type I vestibular hair cells by gentamicin and neomycin.

    PubMed

    Mann, Scott E; Johnson, Matthew; Meredith, Frances L; Rennie, Katherine J

    2013-01-01

    Significant ototoxicity limits the use of aminoglycoside (AG) antibiotics. Several mechanisms may contribute to the death of both auditory and vestibular hair cells. In this study the effects of gentamicin and neomycin on K(+) currents in mature and early postnatal type I vestibular hair cells (HCI) were tested directly. The whole-cell patch clamp technique was used to assess the effects of AG and KCNQ channel modulators on K(+) currents (IK) in HCI acutely isolated from gerbil semicircular canals. Extracellular neomycin (1 mM) rapidly reduced peak outward IK by 16 ± 4% (n = 9) in mature HCI (postnatal days, P, 25-66). Gentamicin (5 mM) reduced outward IK by 16 ± 3% (n = 8). A similar reduction in outward current was seen in immature HCI (P5-9) that lacked the low-voltage-activated component of IK observed in mature cells. Intracellular application of gentamicin and neomycin also reduced IK in mature HCI. Modulators of KCNQ channels were used to probe KCNQ channel involvement. The selective KCNQ antagonist XE991 did not reduce IK and the neomycin-induced reduction in IK was not reversed by the KCNQ agonist flupirtine. Application of intracellular poly-D-lysine to sequester PIP2 did not reduce IK. Application of the K(+) channel blocker 4-aminopyridine (4-AP) strongly reduced IK, and extracellular AG in the presence of 4-AP gave no further inhibition of IK. In summary, AG significantly reduce the 4-AP-sensitive IK in early postnatal and mature HCI. K(+) current inhibition differs from that seen in outer hair cells, since it does not appear to involve PIP2 sequestration or KCNQ channels. PMID:24051519

  2. Vestibular lesion-induced developmental plasticity in spinal locomotor networks during Xenopus laevis metamorphosis.

    PubMed

    Beyeler, Anna; Rao, Guillaume; Ladepeche, Laurent; Jacques, André; Simmers, John; Le Ray, Didier

    2013-01-01

    During frog metamorphosis, the vestibular sensory system remains unchanged, while spinal motor networks undergo a massive restructuring associated with the transition from the larval to adult biomechanical system. We investigated in Xenopus laevis the impact of a pre- (tadpole stage) or post-metamorphosis (juvenile stage) unilateral labyrinthectomy (UL) on young adult swimming performance and underlying spinal locomotor circuitry. The acute disruptive effects on locomotion were similar in both tadpoles and juvenile frogs. However, animals that had metamorphosed with a preceding UL expressed restored swimming behavior at the juvenile stage, whereas animals lesioned after metamorphosis never recovered. Whilst kinematic and electrophysiological analyses of the propulsive system showed no significant differences in either juvenile group, a 3D biomechanical simulation suggested that an asymmetry in the dynamic control of posture during swimming could account for the behavioral restoration observed in animals that had been labyrinthectomized before metamorphosis. This hypothesis was subsequently supported by in vivo electromyography during free swimming and in vitro recordings from isolated brainstem/spinal cord preparations. Specifically, animals lesioned prior to metamorphosis at the larval stage exhibited an asymmetrical propulsion/posture coupling as a post-metamorphic young adult. This developmental alteration was accompanied by an ipsilesional decrease in propriospinal coordination that is normally established in strict left-right symmetry during metamorphosis in order to synchronize dorsal trunk muscle contractions with bilateral hindlimb extensions in the swimming adult. Our data thus suggest that a disequilibrium in descending vestibulospinal information during Xenopus metamorphosis leads to an altered assembly of adult spinal locomotor circuitry. This in turn enables an adaptive compensation for the dynamic postural asymmetry induced by the vestibular imbalance

  3. Vestibular Lesion-Induced Developmental Plasticity in Spinal Locomotor Networks during Xenopus laevis Metamorphosis

    PubMed Central

    Beyeler, Anna; Rao, Guillaume; Ladepeche, Laurent; Jacques, André; Simmers, John; Le Ray, Didier

    2013-01-01

    During frog metamorphosis, the vestibular sensory system remains unchanged, while spinal motor networks undergo a massive restructuring associated with the transition from the larval to adult biomechanical system. We investigated in Xenopus laevis the impact of a pre- (tadpole stage) or post-metamorphosis (juvenile stage) unilateral labyrinthectomy (UL) on young adult swimming performance and underlying spinal locomotor circuitry. The acute disruptive effects on locomotion were similar in both tadpoles and juvenile frogs. However, animals that had metamorphosed with a preceding UL expressed restored swimming behavior at the juvenile stage, whereas animals lesioned after metamorphosis never recovered. Whilst kinematic and electrophysiological analyses of the propulsive system showed no significant differences in either juvenile group, a 3D biomechanical simulation suggested that an asymmetry in the dynamic control of posture during swimming could account for the behavioral restoration observed in animals that had been labyrinthectomized before metamorphosis. This hypothesis was subsequently supported by in vivo electromyography during free swimming and in vitro recordings from isolated brainstem/spinal cord preparations. Specifically, animals lesioned prior to metamorphosis at the larval stage exhibited an asymmetrical propulsion/posture coupling as a post-metamorphic young adult. This developmental alteration was accompanied by an ipsilesional decrease in propriospinal coordination that is normally established in strict left-right symmetry during metamorphosis in order to synchronize dorsal trunk muscle contractions with bilateral hindlimb extensions in the swimming adult. Our data thus suggest that a disequilibrium in descending vestibulospinal information during Xenopus metamorphosis leads to an altered assembly of adult spinal locomotor circuitry. This in turn enables an adaptive compensation for the dynamic postural asymmetry induced by the vestibular imbalance

  4. Therapeutic Approach to the Management of Pediatric Demyelinating Disease: Multiple Sclerosis and Acute Disseminated Encephalomyelitis.

    PubMed

    Brenton, J Nicholas; Banwell, Brenda L

    2016-01-01

    Acquired pediatric demyelinating diseases manifest acutely with optic neuritis, transverse myelitis, acute disseminated encephalomyelitis, or with various other acute deficits in focal or polyfocal areas of the central nervous system. Patients may experience a monophasic illness (as in the case of acute disseminated encephalomyelitis) or one that may manifest as a chronic, relapsing disease [e.g., multiple sclerosis (MS)]. The diagnosis of pediatric MS and other demyelinating disorders of childhood has been facilitated by consensus statements regarding diagnostic definitions. Treatment of pediatric MS has been modeled after data obtained from clinical trials in adult-onset MS. There are now an increasing number of new therapeutic agents for MS, and many will be formally studied for use in pediatric patients. There are important efficacy and safety concerns regarding the use of these therapies in children and young adults. This review will discuss acute management as well as chronic immunotherapies in acquired pediatric demyelination. PMID:26496907

  5. Impact of electromagnetic fields on human vestibular system and standing balance: pilot results and future developments

    NASA Astrophysics Data System (ADS)

    Allen, A.; Villard, S.; Corbacio, M.; Goulet, D.; Plante, M.; Souques, M.; Deschamps, F.; Ostiguy, G.; Lambrozo, J.; Thomas, A. W.; Legros, A.

    2016-03-01

    Although studies have found that extremely low-frequency (ELF, < 300 Hz) magnetic fields (MF) can modulate human standing balance, the acute effects of electromagnetic fields on standing balance have not been systematically investigated. This work aims to establish the threshold for acute standing balance modulation during ELFMF exposure. One hundred volunteers will be exposed to transcranial electric stimulations (Direct Current - DC and Alternating Current - AC, 1 mA) and ELFMF (0 to 160 Hz, 0 to 100 mT). The displacement of their center of pressure will be collected and analyzed as an indicator of vestibular performance. During pilot testing (n=6), we found increased lateral sway with DC, and to a lesser extent, AC exposure. The ELFMF exposure system still needs to be adapted to allow meaningful results. Future protocol design will test for possible effects due to exposures in the radiofrequency range (i.e. above 3 kHz). These results will contribute to the literature documenting exposure guidelines aiming to protect workers and the general public.

  6. Central vestibular disease in a blue and gold macaw (Ara ararauna) with cerebral infarction and hemorrhage.

    PubMed

    Grosset, Claire; Guzman, David Sanchez-Migallon; Keating, M Kelly; Gaffney, Patricia M; Lowenstine, Linda; Zwingenberger, Allison; Young, Alex C; Vernau, Karen M; Sokoloff, Amberly M; Hawkins, Michelle G

    2014-06-01

    A 24-year-old female blue and gold macaw (Ara ararauna) was presented for an acute onset of left head tilt. On examination, the macaw was dehydrated and had a 120-degree left head tilt, decreased proprioception of the left pelvic limb, and intermittent vertical nystagmus. Results of hematologic testing and biochemical analysis revealed severe leukocytosis with lymphopenia and heterophilia and a high uric acid concentration. Radiographs showed bilateral intertarsal joint osteoarthritis and a healed ulnar fracture. Magnetic resonance imaging of the brain revealed focal T2 and fluid-attenuated inversion recovery hyperintense lesions in the right cerebral hemisphere and in the midbrain. The midbrain lesion showed susceptibility artifact on the T2* sequence, suggesting hemorrhage. In the T2* sequence, iron accumulation (as seen with hemorrhage) distorts the magnetic signal, resulting in the production of a susceptibility artifact, which can then be visualized as a region of hypointensity. The bird was hospitalized but died despite intensive care. Necropsy revealed multiple cerebral vascular lesions including an acute cerebral infarct, a ruptured midbrain aneurysm, and multifocal systemic atherosclerosis. To our knowledge, this is the first report of a cerebral aneurysm in a bird. This report correlates the clinical presentation, imaging, and histopathologic findings in a macaw with central vestibular disease and demonstrates how advanced imaging techniques can identify hemorrhagic lesions through the T2* sequence. PMID:25115042

  7. Neuroprotective Effects of Recombinant T-cell Receptor Ligand in Autoimmune Optic Neuritis in HLA-DR2 Mice

    PubMed Central

    Brown, Lori; Andrew, Shayne; Meza-Romero, Roberto; Burrows, Gregory G.; Vandenbark, Arthur A.

    2012-01-01

    Purpose. Optic neuritis (ON) is a condition involving primary inflammation, demyelination, and axonal injury in the optic nerve and leads to apoptotic retinal ganglion cell (RGC) death, which contributes to the persistence of visual loss. Currently, ON has no effective treatment. The goal was to determine the effectiveness of immunotherapy with recombinant T-cell receptor ligand (RTL) in preventing ON in humanized HLA-DR2 transgenic mice. Methods. Experimental autoimmune encephalomyelitis (EAE) was induced with myelin oligodendrocyte glycoprotein in humanized HLA-DR2 (DRβ1*1501) transgenic mice. Five consecutive doses of RTL342M were administrated at the onset of ON. The development of autoimmune ON was assessed by histopathology at different time points. The levels of myelin loss, axonal loss, and RGC damage were examined by immunofluorescence. Results. HLA-DR2 mice developed chronic ON 2 days before EAE characterized by progressive neurodegeneration in both organs. RTL342M significantly suppressed inflammation in the optic nerve and spinal cord and provided protection for at least 30 days. Examination of myelin loss showed a marked suppression of demyelination and an increase in myelin recovery in the optic nerve. Moreover, RTL342M treatment revealed a neuroprotective effect on optic nerve axons and RGCs in retinas at postimmunization (PI) day 62. Conclusions. RTL342M suppressed clinical and histologic signs of EAE/ON by preventing the recruitment of inflammatory cells into the optic nerve and showed neuroprotective effects against ON. However, to achieve full therapeutic benefit, more doses may be needed. These findings suggest a possible clinical application of this novel class of T-cell-tolerizing drugs for patients with optic neuritis. PMID:22167100

  8. Visual-vestibular integration motion perception reporting

    NASA Technical Reports Server (NTRS)

    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

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

    PubMed Central

    Della Santina, Charles C.; Migliaccio, Americo A.; Hayden, Russell; Melvin, Thuy-Anh; Fridman, Gene Y.; Chiang, Bryce; Davidovics, Natan S.; Dai, Chenkai; Carey, John P.; Minor, Lloyd B.; Anderson, Iee-Ching; Park, HongJu; Lyford-Pike, Sofia; Tang, Shan

    2012-01-01

    Bilateral loss of vestibular sensation can disable individuals whose vestibular hair cells are injured by ototoxic medications, infection, Ménière’s disease or other insults to the labyrinth including surgical trauma during cochlear implantation. Without input to vestibulo-ocular and vestibulo-spinal reflexes that normally stabilize the eyes and body, affected patients suffer blurred vision during head movement, postural instability, and chronic disequilibrium. While individuals with some residual sensation often compensate for their loss through rehabilitation exercises, those who fail to do so are left with no adequate treatment options. An implantable neuroelectronic vestibular prosthesis that emulates the normal labyrinth by sensing head movement and modulating activity on appropriate branches of the vestibular nerve could significantly improve quality of life for these otherwise chronically dizzy patients. This brief review describes the impact and current management of bilateral loss of vestibular sensation, animal studies supporting the feasibility of prosthetic vestibular stimulation, and a vestibular prosthesis designed to restore sensation of head rotation in all directions. Similar to a cochlear implant in concept and size, the Johns Hopkins Multichannel Vestibular Prosthesis (MVP) includes miniature gyroscopes to sense head rotation, a microcontroller to process inputs and control stimulus timing, and current sources switched between pairs of electrodes implanted within the vestibular labyrinth. In rodents and rhesus monkeys rendered bilaterally vestibular-deficient via treatment with gentamicin and/or plugging of semicircular canals, the MVP partially restores the vestibulo-ocular reflex for head rotations about any axis of rotation in 3-dimensional space. Our efforts now focus on addressing issues prerequisite to human implantation, including refinement of electrode designs and surgical technique to enhance stimulus selectivity and preserve

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

    PubMed Central

    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

  11. To develop behavioral tests of vestibular functioning in the Wistar rat

    NASA Technical Reports Server (NTRS)

    Nielson, H. C.

    1980-01-01

    Two tests of vestibular functioning in the rat were developed. The first test was the water maze. In the water maze the rat does not have the normal proprioceptive feedback from its limbs to help it maintain its orientation, and must rely primarily on the sensory input from its visual and vestibular systems. By altering lighting conditions and visual cues the vestibular functioning without visual cues was assessed. Whether there was visual compensation for some vestibular dysfunction was determined. The second test measured vestibular functioning of the rat's behavior on a parallel swing. In this test the rat's postural adjustments while swinging on the swing with the otoliths being stimulated were assessed. Less success was achieved in developing the parallel swing as a test of vestibular functioning than with the water maze. The major problem was incorrect initial assumptions of what the rat's probable behavior on the parallel swing would be.

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

    PubMed Central

    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-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. PMID:24367303

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

    PubMed

    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

  14. [Treatment research progress on the treatment of neurofibromatosis type 2-associated vestibular schwannoma].

    PubMed

    Zhao, Yingchao; Yang, Qin; Jiang, Yao

    2015-05-01

    Neurofibromatosis type 2 (NF2) is a dominantly inherited genetic condition. Bilateral vestibular schwannoma, which are benign tumors, composed of neoplastic Schwann cells that arise from the eighth cranial nerve, are the hallmark of NF2. Standard approaches for treatment of growing vestibular schwannoma include observation, surgical removal and radiation therapy. Molecular targeted therapies also present great prosperity in recent years. In this review, we summarize the latest progresses on the treatment of NF2-associated vestibular schwannoma. PMID:26596021

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

    NASA Technical Reports Server (NTRS)

    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.

  16. Dizziness and Vertigo (Beyond the Basics)

    MedlinePlus

    ... and certain infections can cause problems in the vestibular system. The vestibular system includes parts of the inner ear and ... 1 ). Benign paroxysmal positional vertigo, Meniere disease, and vestibular neuritis are three of the most common types ...

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

    PubMed Central

    Pfeiffer, Christian; Serino, Andrea; Blanke, Olaf

    2014-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

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

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

    PubMed Central

    Ventre-Dominey, Jocelyne

    2014-01-01

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

  20. Vestibular involvement in cognition: Visuospatial ability, attention, executive function, and memory.

    PubMed

    Bigelow, Robin T; Agrawal, Yuri

    2015-01-01

    A growing body of literature suggests the inner ear vestibular system has a substantial impact on cognitive function. The strongest evidence exists in connecting vestibular function to the cognitive domain of visuospatial ability, which includes spatial memory, navigation, mental rotation, and mental representation of three-dimensional space. Substantial evidence also exists suggesting the vestibular system has an impact on attention and cognitive processing ability. The cognitive domains of memory and executive function are also implicated in a number of studies. We will review the current literature, discuss possible causal links between vestibular dysfunction and cognitive performance, and suggest areas of future research. PMID:26410672

  1. Experimental and clinical study of EHF treatment of vascular-vestibular dysfunction

    SciTech Connect

    Mal`tsev, A.E.; Abakarov, A.T.; Istomin, V.S.

    1994-07-01

    The authors present the results of a study of the effectiveness of EHF radiation on the cerebral hemodynamics, bioelectrical activity of the cerebral cortex, and functional state of the vestibular analyzer in chronic studies of cats using a model of vascular-vestibular dysfunction. The clinical part of the work reflects the results of studies of the functional state of cerebral blood circulation and the vestibular analyzer during the EHF treatment of angiovertebrogenic vestibular dysfunction in a background of initial manifestations of cerebral blood supply deficiency (angiodistonic variant).

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

    PubMed

    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

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

    PubMed

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

    2002-05-01

    The major goal of this study was to determine the patterns of convergence of non-labyrinthine inputs from the limbs and viscera onto vestibular nucleus neurons receiving signals from vertical semicircular canals or otolith organs. A secondary aim was to ascertain whether the effects of non-labyrinthine inputs on the activity of vestibular nucleus neurons is affected by bilateral peripheral vestibular lesions. The majority (72%) of vestibular nucleus neurons in labyrinth-intact animals whose firing was modulated by vertical rotations responded to electrical stimulation of limb and/or visceral nerves. The activity of even more vestibular nucleus neurons (93%) was affected by limb or visceral nerve stimulation in chronically labyrinthectomized preparations. Some neurons received non-labyrinthine inputs from a variety of peripheral sources, including antagonist muscles acting at the same joint, whereas others received inputs from more limited sources. There was no apparent relationship between the spatial and dynamic properties of a neuron's responses to tilts in vertical planes and the non-labyrinthine inputs that it received. These data suggest that non-labyrinthine inputs elicited during movement will modulate the processing of information by the central vestibular system, and may contribute to the recovery of spontaneous activity of vestibular nucleus neurons following peripheral vestibular lesions. Furthermore, some vestibular nucleus neurons with non-labyrinthine inputs may be activated only during particular behaviors that elicit a specific combination of limb and visceral inputs. PMID:12012162

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

    PubMed

    Medrea, Ioana; Cullen, Kathleen E

    2013-12-01

    The mouse has become an important model system for studying the cellular basis of learning and coding of heading by the vestibular system. Here we recorded from single neurons in the vestibular nuclei to understand how vestibular pathways encode self-motion under natural conditions, during which proprioceptive and motor-related signals as well as vestibular inputs provide feedback about an animal's movement through the world. We recorded neuronal responses in alert behaving mice focusing on a group of neurons, termed vestibular-only cells, that are known to control posture and project to higher-order centers. We found that the majority (70%, n = 21/30) of neurons were bimodal, in that they responded robustly to passive stimulation of proprioceptors as well as passive stimulation of the vestibular system. Additionally, the linear summation of a given neuron's vestibular and neck sensitivities predicted well its responses when both stimuli were applied simultaneously. In contrast, neuronal responses were suppressed when the same motion was actively generated, with the one striking exception that the activity of bimodal neurons similarly and robustly encoded head on body position in all conditions. Our results show that proprioceptive and motor-related signals are combined with vestibular information at the first central stage of vestibular processing in mice. We suggest that these results have important implications for understanding the multisensory integration underlying accurate postural control and the neural representation of directional heading in the head direction cell network of mice. PMID:24089394

  5. Muscle-specific modulation of vestibular reflexes with increased locomotor velocity and cadence.

    PubMed

    Dakin, Christopher J; Inglis, John Timothy; Chua, Romeo; Blouin, Jean-Sébastien

    2013-07-01

    Vestibular information is one of the many sensory signals used to stabilize the body during locomotion. When locomotor velocity increases, the influence of these signals appears to wane. It is unclear whether vestibular signals are globally attenuated with velocity or are influenced by factors such as whether a muscle is contributing to balance control. Here we investigate how vestibular sensory signals influence muscles of the leg during locomotion and what causes their attenuation with increasing locomotor velocity. We hypothesized that 1) vestibular signals influence the activity of all muscles engaged in the maintenance of medio-lateral stability during locomotion and 2) increases in both cadence and velocity would be associated with attenuation of these signals. We used a stochastic vestibular stimulus and recorded electromyographic signals from muscles of the ankle, knee, and hip. Participants walked using two cadences (52 and 78 steps/min) and two walking velocities (0.4 and 0.8 m/s). We observed phase-dependent modulation of vestibular influence over ongoing muscle activity in all recorded muscles. Within a stride, reversals of the muscle responses were observed in the biceps femoris, tibialis anterior, and rectus femoris. Vestibular-muscle coupling decreases with increases in both cadence and walking velocity. These results show that the observed vestibular suppression is muscle- and phase dependent. We suggest that the phase- and muscle-specific influence of vestibular signals on locomotor activity is organized according to each muscle's functional role in body stabilization during locomotion. PMID:23576695

  6. Galvanic vestibular stimulation for analysis of postural adaptation and stability.

    PubMed

    Johansson, R; Magnusson, M; Fransson, P A

    1995-03-01

    Human postural dynamics was investigated in 12 normal subjects by means of a force platform recording body sway, induced by bipolar transmastoid galvanic stimulation of the vestibular nerve and labyrinth. The model adopted was that of an inverted segmented pendulum, the dynamics of postural control being assumed to be reflected in the stabilizing forces actuated by the feet as a result of complex muscular activity subject to state feedback of body sway and position. Time-series analysis demonstrates that a transfer function from stimulus to sway-force response with specific parameters can be identified. In addition, adaptation to the vestibular stimulus is demonstrated to exist, and we describe this phenomenon using quantification in terms of a postural adaptation time constant in the range of 40-50 s. The results suggest means to evaluate adaptive behavior and postural control in the erect human being which may be useful in the rehabilitation of individuals striving to regain upright stance. PMID:7698784

  7. A model describing vestibular detection of body sway motion.

    NASA Technical Reports Server (NTRS)

    Nashner, L. M.

    1971-01-01

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

  8. Effects of Weightlessness on Vestibular Development of Quail

    NASA Technical Reports Server (NTRS)

    Fritzsch, Bernd; Bruce, Laura L.

    1997-01-01

    The lack of gravity is known to alter vestibular responses in developing and adult vertebrates. One cause of these altered responses may be changes in the connections between the vestibular receptor and the brain. Therefore we propose to investigate the effects of gravity on the formations of connections between the gravity receptors of the ear and the brain in developing quail incubated in space beginning at an age before these connections are established (incubation day three) until near the time of hatching, when they are to some extent functional. This investigation will make use of a novel technique, the diffusion of a lipophilic dye, DiI, in fixed tissue. This technique can thus be used to analyze the connections in specimens fixed in orbit, thus eliminating changes due to the earth's gravity. The evaluation of the data will enable us to detect gross deviations from normal patterns as well as detailed quantitative deviations.

  9. Space motion sickness and vestibular adaptation to weightlessness

    NASA Technical Reports Server (NTRS)

    Young, L. R.

    1983-01-01

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

  10. Input/output properties of the lateral vestibular nucleus

    NASA Technical Reports Server (NTRS)

    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.

  11. Antagonistic otolith-visual units in cat vestibular nuclei

    NASA Technical Reports Server (NTRS)

    Daunton, Nancy G.; Christensen, Carol A.

    1992-01-01

    The nature of neural coding of visual (Vis) and vestibular (Vst) information on translational motion in the region of the vestibular nuclei was investigated using extracellular single-unit recordings in alert adult cats. Responses were recorded and averaged over 60 cycles of stimulation in the vertical and horizontal planes, which included the Vst (movement of the animal in the dark), Vis (movement within lighted visual surround), and combined Vis and Vst (movement of the animal within the lighted stationary visual surround). Data are reported on responses to stimulations along the axis showing maximal sensitivity. A small number of units were identified that showed an antagonistic relationship between their Vis and Vst responses (since they were maximally excited by Vis and by Vst stimulations in the same direction). Results suggest that antagonistic units may belong to an infrequently encountered, but functionally distinct, class of neurons.

  12. Research on biophysical evaluation of the human vestibular system

    NASA Technical Reports Server (NTRS)

    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.

  13. Marine Corps Breacher Training Study: auditory and vestibular findings.

    PubMed

    St Onge, Paul; McIlwain, David S; Hill, Melinda E; Walilko, Timothy J; Bardolf, Lynette B

    2011-01-01

    This article presents an overview of a contemporary research protocol conducted at the Marine Corps Weapons Training Battalion, Quantico, VA. The study was a comprehensive collaborative research initiative that evaluated a variety of environmental, auditory, and vestibular factors among Marines enrolled in the Breacher Training Course. The length of each course is 2 weeks and involves multiple exposures to blast overpressure and physical shock from ingress strategies used during the training. Observational data were collected pretraining, during training, and posttraining between September and June 2007. There was no change in the way the Marines conducted their training, and all data were collected based on the actual training scenario. The primary objective of this research protocol was to determine if Marines in the Breacher Training Course were at risk of injury during standard training practices. The principal conclusions were that hearing loss was statistically and clinically significant whereas the vestibular findings were overall unremarkable. PMID:21805461

  14. Vestibular rehabilitation strategies and factors that affect the outcome.

    PubMed

    Eleftheriadou, Anna; Skalidi, Nikoleta; Velegrakis, Georgios A

    2012-11-01

    Ever since the introduction of Cawthorne-Cooksey exercises, vestibular rehabilitation (VR) has been gaining popularity in the treatment of the dizzy patient. Numerous studies support the effectiveness of VR in improving balance/walking skills, eye-head coordination and the quality of life of the patient. Different rehabilitation protocols have been used to treat patients with peripheral and central vestibular disorders. Assessment of the patients' progress is based on the patients' selfperception of dizziness and their functional skills. Factors such as age, medication, time of onset of vertigo and home based VR have been evaluated on their effect on the rehabilitation's outcome. The aim of this review is to evaluate rehabilitation strategies and discuss the factors that affect the outcome. PMID:22526580

  15. [Vestibular rehabilitation in patients with relapsing-remitting multiple sclerosis].

    PubMed

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

    2007-06-01

    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. PMID:17607438

  16. Representation of visual gravitational motion in the human vestibular cortex.

    PubMed

    Indovina, Iole; Maffei, Vincenzo; Bosco, Gianfranco; Zago, Myrka; Macaluso, Emiliano; Lacquaniti, Francesco

    2005-04-15

    How do we perceive the visual motion of objects that are accelerated by gravity? We propose that, because vision is poorly sensitive to accelerations, an internal model that calculates the effects of gravity is derived from graviceptive information, is stored in the vestibular cortex, and is activated by visual motion that appears to be coherent with natural gravity. The acceleration of visual targets was manipulated while brain activity was measured using functional magnetic resonance imaging. In agreement with the internal model hypothesis, we found that the vestibular network was selectively engaged when acceleration was consistent with natural gravity. These findings demonstrate that predictive mechanisms of physical laws of motion are represented in the human brain. PMID:15831760

  17. Verticality perception during and after galvanic vestibular stimulation.

    PubMed

    Volkening, Katharina; Bergmann, Jeannine; Keller, Ingo; Wuehr, Max; Müller, Friedemann; Jahn, Klaus

    2014-10-01

    The human brain constructs verticality perception by integrating vestibular, somatosensory, and visual information. Here we investigated whether galvanic vestibular stimulation (GVS) has an effect on verticality perception both during and after application, by assessing the subjective verticals (visual, haptic and postural) in healthy subjects at those times. During stimulation the subjective visual vertical and the subjective haptic vertical shifted towards the anode, whereas this shift was reversed towards the cathode in all modalities once stimulation was turned off. Overall, the effects were strongest for the haptic modality. Additional investigation of the time course of GVS-induced changes in the haptic vertical revealed that anodal shifts persisted for the entire 20-min stimulation interval in the majority of subjects. Aftereffects exhibited different types of decay, with a preponderance for an exponential decay. The existence of such reverse effects after stimulation could have implications for GVS-based therapy. PMID:25157799

  18. Comparative Transduction Mechanisms of Vestibular Otolith Hair Cells

    NASA Technical Reports Server (NTRS)

    Baird, Richard A.

    1994-01-01

    Hair cells in the bullfrog vestibular otolith organs regenerate following aminoglycoside ototoxicity. Hair cells in these organs are differentially sensitive to gentamicin, with saccular hair cells and hair cells in the utricular striola being damaged at lower gentamicin concentrations than hair cells in the utricular extrastriola. Regenerating hair cells in these organs have short hair bundles and can be classified into a number of phenotypes using the same morphological criteria used to identify their mature counterparts. Our studies suggest that some supporting cells can convert, or transdifferentiate,into hair cells without an intervening cell division. By stimulating these processes in humans, clinicians may be able to alleviate human deafness and peripheral vestibular disorders by regenerating and replacing lost hair cells. In vivo and in vitro studies were done on cell proliferation and hair cell regeneration.

  19. Image-guided drainage of cystic vestibular schwannomata.

    PubMed

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

    2010-01-01

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

  20. Bilateral vestibular deficiency: quality of life and economic implications

    PubMed Central

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

    2014-01-01

    Importance Bilateral vestibular deficiency (BVD) causes chronic imbalance, unsteady vision, and greatly increases the risk of falls; however, its effects on quality of life (QOL) and economic impact are not well defined. Objective Quantify disease-specific and health-related quality of life, health care utilization and economic impact suffered by individuals with BVD in comparison to those with unilateral vestibular deficiency (UVD) Design Cross-sectional survey study of BVD, UVD, and healthy individuals Setting Academic medical center Participants Fifteen BVD, 22 UVD and 23 healthy individuals. Vestibular dysfunction was diagnosed by caloric nystagmography Intervention Survey questionnaire Main Outcomes and Measures Health status was measured using the Dizziness Handicap Index (DHI) and Health Utility Index Mark 3 (HUI3). Economic burden was estimated using participant responses to questions on disease-specific health care utilization and lost productivity. Results In comparison to UVD and normal controls, BVD patients had significantly worse DHI and HUI3 scores. Multivariate regression analysis showed UVD, BVD, increasing number of dizziness-related emergency department (ED) visits, and increasing dizziness-related work-place absenteeism were associated with worse HUI3 scores. BVD and UVD patients incurred annual economic burdens of $13,019 and $3,531 per patient, respectively. Conclusions and Relevance BVD significantly decreases quality of life and imposes substantial economic burdens on individuals and society. These results underscore the limits of adaptation and compensation in BVD. Furthermore, they quantify the potential benefits of prosthetic restoration of vestibular function both to these individuals and to society. PMID:24763518

  1. The effects of cochlear implantation on vestibular function

    PubMed Central

    Melvin, Thuy-Anh N.; Della Santina, Charles C.; Carey, John P.; Migliaccio, Americo A.

    2009-01-01

    Objective Determine the risk posed by cochlear implantation (CI) to the labyrinth. Study Design Prospective cohort study. Setting Academic tertiary referral center. Patients Thirty-six ears belonging to 35 adult CI candidates (mean: 46, range: 23–69 years old). Intervention Cochlear implantation. Main Outcome Measures Vestibular function was assessed using the quantitative 3D head impulse test (qHIT), clinical head impulse test (cHIT), post-headshake nystagmus (HSN), caloric electronystagmography (ENG), vestibular-evoked myogenic potentials (VEMP), dynamic visual acuity (DVA), and Dizziness Handicap Inventory (DHI). Results All 36 ears were tested using qHIT before CI, and 28 ears were tested 4–8 weeks after CI. Quantitative HIT showed 1/28 of ears suffered reduced function. Clinical HIT was 44% sensitive and 94% specific for identification of severe-to-profound vestibular hypofunction confirmed by qHIT. HSN was unchanged in 11/11 subjects. New hyporeflexia was found in 1/16 of ENG-tested ears. VEMP showed either a disappearance of response or an increase in threshold by >10dB in 5/16 ears. Passive DVA showed no change in 16/16 ears. DHI scores worsened in 3/28 and improved in 4/28 subjects. Conclusions Although small, the observed rate of labyrinthine injury was comparable to that for other risks of CI. Thus, it is important to educate CI candidates about possible risk to balance function, particularly when CI of an “only balancing ear” is contemplated. Clinical HIT is useful for detecting severe high-frequency vestibular hypofunction and should be part of the pre-CI physical examination. PMID:19108038

  2. Student learns about the vestibular system in a microgravity demonstration

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Gary Coulter, a special assistant to NASA's life sciences researchers, explains the workings of the irner ear to a Virginia student. The chair rotates to disorient the vestibular system in a simulation of research on how astronauts adapt to space and readapt to Earth. The activity was part of the Space Research and You education event held by NASA's Office of Biological and Physical Research on June 25, 2002, in Arlington, VA, to highlight the research that will be conducted on STS-107.

  3. Vestibular Evoked Myogenic Potentials in a Female Population with Migraine.

    PubMed

    Yetiser, Sertac; Gok, Meltem Hale; Kutukcu, Yasar; Ince, Dilay

    2016-06-01

    The objective is to analyze the vestibular system by vestibular evoked myogenic potential (VEMP) in 30 female patients with migraine and balance problem in a controlled study. Thirty female patients with migraine and vestibular problems were enrolled in the study (2009-2012). Fifteen age-matched healthy subjects were selected as the controls. Air conduction cervical VEMP was used. Tone-burst sound stimuli of 95 dB nHL with rarefaction polarity, 5 Hz stimulus repetition rate, 1 ms rise/fall time and 2 ms plateau time were delivered at 500 Hz. 200 sweeps were averaged. Myogenic responses were amplified and band-pass filtered (800-10 Hz). The latency and the amplitude of p1 and n1 waves and interpeak amplitude and latency differences were measured. Results were given as mean and SDs. Interaural p1 and n1 amplitude greater than 30 % asymmetry was accepted as abnormal. VEMP results were compared with controls. The One-way ANOVA test was used. Statistical significance was set at P < 0.05. VEMP responses were elicited in all controls and the patients. Comparative analysis of p1 amplitude between the patients and the controls was statistically significant (P = 0.010). P1n1 interaural amplitude difference was greater than 30 % in 4 patients (13.4 %). No statistically significant difference was found when comparing latency of all wave forms between the patients and healthy controls (P > 0.05). VEMP is an useful tool to test the vestibular system in patients with migraine and balance problem at the very early period. Clinicians should always consider migraine in patients with vertigo. PMID:27340638

  4. Investigation of otolith responses using ground based vestibular research facility

    NASA Technical Reports Server (NTRS)

    Correia, Manning J.; TABARACCI

    1989-01-01

    The general goal was to examine tilt sensitivity of horizontal semicircular canal afferents. Computer programs were tested which controlled the short axis centrifuge at the Vestibular Research Facility, acquired action potentials and produced data reduction analyses including histograms and gain and phase calculations. A pre-amplifier was also developed for the acquisition of action potentials. The data were gathered that can be used to contribute toward the understanding of the tilt sensitivity of semicircular canal afferents in the unanesthetized gerbil preparation.

  5. Galvanic vestibular stimulation in hemi-spatial neglect.

    PubMed

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

    2014-01-01

    Hemi-spatial neglect is an attentional disorder in which the sufferer fails to acknowledge or respond to stimuli appearing in contralesional space. In recent years, it has become clear that a measurable reduction in contralesional neglect can occur during galvanic vestibular stimulation, a technique by which transmastoid, small amplitude current induces lateral, attentional shifts via asymmetric modulation of the left and right vestibular nerves. However, it remains unclear whether this reduction persists after stimulation is stopped. To estimate longevity of effect, we therefore conducted a double-blind, randomized, dose-response trial involving a group of stroke patients suffering from left-sided neglect (n = 52, mean age = 66 years). To determine whether repeated sessions of galvanic vestibular stimulation more effectively induce lasting relief than a single session, participants received 1, 5, or 10 sessions, each lasting 25 min, of sub-sensory, left-anodal right-cathodal noisy direct current (mean amplitude = 1 mA). Ninety five percent confidence intervals indicated that all three treatment arms showed a statistically significant improvement between the pre-stimulation baseline and the final day of stimulation on the primary outcome measure, the conventional tests of the Behavioral Inattention Test. More remarkably, this change (mean change = 28%, SD = 18) was still evident 1 month later. Secondary analyses indicated an allied increase of 20% in median Barthel Index (BI) score, a measure of functional capacity, in the absence of any adverse events or instances of participant non-compliance. Together these data suggest that galvanic vestibular stimulation, a simple, cheap technique suitable for home-based administration, may produce lasting reductions in neglect that are clinically important. Further protocol optimization is now needed ahead of a larger effectiveness study. PMID:24523679

  6. Alignment of angular velocity sensors for a vestibular prosthesis.

    PubMed

    Digiovanna, Jack; Carpaneto, Jacopo; Micera, Silvestro; Merfeld, Daniel M

    2012-01-01

    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. PMID:22329908

  7. Alignment of angular velocity sensors for a vestibular prosthesis

    PubMed Central

    2012-01-01

    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. PMID:22329908

  8. Comparative anatomy of the vestibular nuclear complex in submammalian vertebrates.

    NASA Technical Reports Server (NTRS)

    Mehler, W. R.

    1972-01-01

    A synopsis of the literature on the natural history of the vestibular nuclear complex (VNC) in lower vertebrates is presented in an attempt to assess the knowledge available. The review discloses that there is considerable descriptive information that is widely dispersed in the literature. However, information about the topology, number, and cellular composition of the cell groups that compose the VNC is sketchy. Major cytological and hodological information is still needed to establish which parts of the VNC actually are homologous.

  9. Galvanic vestibular stimulation in hemi-spatial neglect

    PubMed Central

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

    2014-01-01

    Hemi-spatial neglect is an attentional disorder in which the sufferer fails to acknowledge or respond to stimuli appearing in contralesional space. In recent years, it has become clear that a measurable reduction in contralesional neglect can occur during galvanic vestibular stimulation, a technique by which transmastoid, small amplitude current induces lateral, attentional shifts via asymmetric modulation of the left and right vestibular nerves. However, it remains unclear whether this reduction persists after stimulation is stopped. To estimate longevity of effect, we therefore conducted a double-blind, randomized, dose-response trial involving a group of stroke patients suffering from left-sided neglect (n = 52, mean age = 66 years). To determine whether repeated sessions of galvanic vestibular stimulation more effectively induce lasting relief than a single session, participants received 1, 5, or 10 sessions, each lasting 25 min, of sub-sensory, left-anodal right-cathodal noisy direct current (mean amplitude = 1 mA). Ninety five percent confidence intervals indicated that all three treatment arms showed a statistically significant improvement between the pre-stimulation baseline and the final day of stimulation on the primary outcome measure, the conventional tests of the Behavioral Inattention Test. More remarkably, this change (mean change = 28%, SD = 18) was still evident 1 month later. Secondary analyses indicated an allied increase of 20% in median Barthel Index (BI) score, a measure of functional capacity, in the absence of any adverse events or instances of participant non-compliance. Together these data suggest that galvanic vestibular stimulation, a simple, cheap technique suitable for home-based administration, may produce lasting reductions in neglect that are clinically important. Further protocol optimization is now needed ahead of a larger effectiveness study. PMID:24523679

  10. Glucocorticoids improve acute dizziness symptoms following acute unilateral vestibulopathy.

    PubMed

    Batuecas-Caletrío, Angel; Yañez-Gonzalez, Raquel; Sanchez-Blanco, Carmen; Pérez, Pedro Blanco; González-Sanchez, Enrique; Sanchez, Luis Alberto Guardado; Kaski, Diego

    2015-11-01

    Acute unilateral vestibulopathy (AUV) is characterized by acute vertigo, nausea, and imbalance without neurological deficits or auditory symptomatology. Here, we explore the effect of glucocorticoid treatment on the degree of canal paresis in patients with AUV, and critically, establish its relationship with dizziness symptom recovery. We recruited consecutive patients who were retrospectively assigned to one of the two groups according to whether they received glucocorticoid treatment (n = 32) or not (n = 44). All patients underwent pure-tone audiometry, bithermal caloric testing, MRI brain imaging, and were asked to complete a dizziness handicap inventory on admission to hospital and just prior to hospital discharge. In the treatment group, the canal paresis at discharge was significantly lower than in the control group (mean ± SD % 38.04 ± 21.57 versus 82.79 ± 21.51, p < 0.001). We also observed a significant reduction in the intensity of nystagmus in patients receiving glucocorticoid treatment compared to the non-treatment group (p = 0.03). DHI test score was significantly lower at discharge in the treatment group (mean ± SD % 23.15 ± 12.40 versus 64.07 ± 12.87, p < 0.001), as was the length of hospital stay (2.18 ± 1.5 days versus 3.6 ± 1.7 days, p = 0.002). Glucocorticoid treatment leads to acute symptomatic improvement, with a reduced hospital stay and reduction in the intensity of acute nystagmus. Our findings suggest that glucocorticoids may accelerate vestibular compensation via a restoration of peripheral vestibular function, and therefore has important clinical implications for the treatment of AUV. PMID:26459091

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

    NASA Technical Reports Server (NTRS)

    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.

  12. Vestibular regeneration – experimental models and clinical implications

    PubMed Central

    Albu, Silviu; Muresanu, Dafin F

    2012-01-01

    Therapies aimed at the protection and/or regeneration of inner ear hair cells are of great interest, given the significant monetary and quality of life impact of balance disorders. Different viral vectors have been shown to transfect various cell types in the inner ear. The past decade has provided tremendous advances in the use of adenoviral vectors to achieve targeted treatment delivery. Several routes of delivery have been identified to introduce vectors into the inner ear while minimizing injury to surrounding structures. Recently, the transcription factor Atoh1 was determined to play a critical role in hair cell differentiation. Adenoviral-mediated overexpression of Atoh1 in culture and in vivo has demonstrated the ability to regenerate vestibular hair cells by causing transdifferentiation of neighbouring epithelial-supporting cells. Functional recovery of the vestibular system has also been documented following adenoviral-induced Atoh1 overexpression. Experiments demonstrating gene transfer in human vestibular epithelial cells reveal that the human inner ear is a suitable target for gene therapy. PMID:22303988

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

    NASA Technical Reports Server (NTRS)

    Fox, Robert A.; Polyakov, Igor

    1999-01-01

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

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

    PubMed

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

    2014-10-29

    In the vestibular periphery a unique postsynaptic terminal, the calyx, completely covers the basolateral walls of type I hair cells and receives input from multiple ribbon synapses. To date, the functional role of this specialized synapse remains elusive. There is limited data supporting glutamatergic transmission, K(+) or H(+) accumulation in the synaptic cleft as mechanisms of transmission. Here the role of glutamatergic transmission at the calyx synapse is investigated. Whole-cell patch-clamp recordings from calyx endings were performed in an in vitro whole-tissue preparation of the rat vestibular crista, the sensory organ of the semicircular canals that sense head rotation. AMPA-mediated EPSCs showed an unusually wide range of decay time constants, from <5 to >500 ms. Decay time constants of EPSCs increased (or decreased) in the presence of a glutamate transporter blocker (or a competitive glutamate receptor blocker), suggesting a role for glutamate accumulation and spillover in synaptic transmission. Glutamate accumulation caused slow depolarizations of the postsynaptic membrane potentials, and thereby substantially increased calyx firing rates. Finally, antibody labelings showed that a high percentage of presynaptic ribbon release sites and postsynaptic glutamate receptors were not juxtaposed, favoring a role for spillover. These findings suggest a prominent role for glutamate spillover in integration of inputs and synaptic transmission in the vestibular periphery. We propose that similar to other brain areas, such as the cerebellum and hippocampus, glutamate spillover may play a role in gain control of calyx afferents and contribute to their high-pass properties. PMID:25355208

  15. Visual/vestibular effects of inert gas narcosis.

    PubMed

    Hamilton, K; Laliberte, M F; Heslegrave, R; Khan, S

    1993-08-01

    Divers breathing compressed air at depths beyond 30 m experience a type of behavioural impairment known as inert gas narcosis. This condition degrades performance on a wide range of tasks and has the potential to compromise safety. Symptoms associated with narcosis include slowed response time, amnesia, and euphoria. Studies have also found disturbances to mechanisms regulating ocular control in response to vestibular stimulation; however, these experiments have been limited to very low frequency head movement (0.2 Hz). Thus, to further examine the effects of narcosis on visual/vestibular mechanisms, the vestibular ocular reflex (VOR) was assessed across a range of higher frequencies more representative of natural head movement (2.0-4.7 Hz). Seven subjects were tested prior to, during and after exposure to narcosis which was induced using 30% nitrous oxide. Standard room air was breathed as a control. The results indicated that narcosis decreased the velocity of compensatory eye movements in response to head rotation (decrease in VOR-gain), with more pronounced decreases occurring at the higher frequencies. The lag between eye and head position (phase lag) was also decreased by nitrous oxide; an effect that was again more pronounced at higher frequencies. These results indicate that narcosis disrupts ocular regulatory mechanisms which help to stabilize images on the retina during head movement. PMID:8365388

  16. Small Vestibular Schwannomas: Does Surgery Remain a Viable Treatment Option?

    PubMed

    Anaizi, Amjad N; DiNapoli, Vincent V; Pensak, Myles; Theodosopoulos, Philip V

    2016-06-01

    Background Surgery for small vestibular schwannomas (Koos grade I and II) has been increasingly rejected as the optimal primary treatment, instead favoring radiosurgery and observation that offer lower morbidity and potentially equal efficacy. Our study assesses the outcomes of contemporary surgical strategies including tumor control, functional preservation, and implications of pathologic findings. Design Retrospective review. Setting/Participants Eighty consecutive patients (45 women, 35 men; mean: 47 years of age). Main Outcomes Measures Approaches included retrosigmoid approach (52%), translabyrinthine (40%), and middle fossa (8%). Operated on by the same surgical team, we analyzed presentation, radiographic imaging, surgical data, and outcomes. Results At last follow-up (mean: 34 months), 95% had good facial nerve function (House-Brackmann grade I or II); 36% who presented with serviceable hearing retained it; and 93% who presented with vestibular dysfunction reported resolution. Pathology identified two grade I meningiomas. Conclusions As one of the largest contemporary surgical series of small vestibular schwannomas, we discuss some nuances to help refine treatment algorithms. Although observation and radiosurgery have established roles, our results reinforce microsurgery as a viable, safe option for a subgroup of patients. PMID:27175315

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

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

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

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

    NASA Technical Reports Server (NTRS)

    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.

  19. Sodium channel diversity in the vestibular ganglion: NaV1.5, NaV1.8, and tetrodotoxin-sensitive currents.

    PubMed

    Liu, Xiao-Ping; Wooltorton, Julian R A; Gaboyard-Niay, Sophie; Yang, Fu-Chia; Lysakowski, Anna; Eatock, Ruth Anne

    2016-05-01

    Firing patterns differ between subpopulations of vestibular primary afferent neurons. The role of sodium (NaV) channels in this diversity has not been investigated because NaV currents in rodent vestibular ganglion neurons (VGNs) were reported to be homogeneous, with the voltage dependence and tetrodotoxin (TTX) sensitivity of most neuronal NaV channels. RT-PCR experiments, however, indicated expression of diverse NaV channel subunits in the vestibular ganglion, motivating a closer look. Whole cell recordings from acutely dissociated postnatal VGNs confirmed that nearly all neurons expressed NaV currents that are TTX-sensitive and have activation midpoints between -30 and -40 mV. In addition, however, many VGNs expressed one of two other NaV currents. Some VGNs had a small current with properties consistent with NaV1.5 channels: low TTX sensitivity, sensitivity to divalent cation block, and a relatively negative voltage range, and some VGNs showed NaV1.5-like immunoreactivity. Other VGNs had a current with the properties of NaV1.8 channels: high TTX resistance, slow time course, and a relatively depolarized voltage range. In two NaV1.8 reporter lines, subsets of VGNs were labeled. VGNs with NaV1.8-like TTX-resistant current also differed from other VGNs in the voltage dependence of their TTX-sensitive currents and in the voltage threshold for spiking and action potential shape. Regulated expression of NaV channels in primary afferent neurons is likely to selectively affect firing properties that contribute to the encoding of vestibular stimuli. PMID:26936982

  20. Imidazol-1-ylethylindazole Voltage-Gated Sodium Channel Ligands Are Neuroprotective during Optic Neuritis in a Mouse Model of Multiple Sclerosis

    PubMed Central

    2014-01-01

    A series of imidazol-1-ylethylindazole sodium channel ligands were developed and optimized for sodium channel inhibition and in vitro neuroprotective activity. The molecules exhibited displacement of a radiolabeled sodium channel ligand and selectivity for blockade of the inactivated state of cloned neuronal Nav channels. Metabolically stable analogue 6 was able to protect retinal ganglion cells during optic neuritis in a mouse model of multiple sclerosis. PMID:24601592