The Video Head Impulse Test in a Case of Suspected Bilateral Loss of Vestibular Function.
ABSTRACT: Introduction A patient who had no symptoms suggestive of bilateral loss of vestibular function presented no responses in rotational and caloric tests. Objectives To demonstrate the importance of the video head impulse test in neuro-otologic diagnosis. Resumed Report This patient had a neuro-otologic evaluation and presented no responses in torsion swing tests, caloric tests, and rotational tests in a Bárány chair. The video head impulse test elicited responses in four of the six semicircular canals. Conclusion Absent responses in caloric and rotatory tests alone are not sufficient to diagnose bilateral loss of vestibular function.
Project description:Non-encephalopathic presentations of CNS thiamine deficiency may be difficult to diagnose. We describe neuro-otologic findings of Wernicke syndrome in 5 patients with vestibular manifestations. Diagnosis was confirmed by low serum levels, response to replacement, and brain MRI to exclude other causes. All had bilaterally abnormal horizontal head impulse vestibulo-ocular reflex (VOR) responses and pathologic gaze-evoked nystagmus, without encephalopathy. After thiamine replacement, 4 had total resolution of vestibular and oculomotor findings. Novel findings included 2 patients whose VOR function improved within minutes of IV repletion and 1 whose recovery was documented by serial quantitative recordings. Early diagnosis of Wernicke by examining vestibular reflexes and prompt IV treatment might prevent encephalopathy and other neurologic or systemic complications of thiamine depletion.
Project description:OBJECTIVES:To identify predictive factors for falls in patients with bilateral vestibulopathy (BV). Specific variables contributing to the general work-up of a vestibular patient were compared between BV patients experiencing falls and those who did not. DESIGN:Prospective multi-centric cohort study. SETTING:Department of Otorhinolaryngology & Head and Neck Surgery at two tertiary referral centers: Antwerp University Hospital and Maastricht University Medical Center. PARTICIPANTS:In total, 119 BV patients were included. BV diagnosis was defined in accordance with the diagnostic BV criteria, established by the Bárány Society in 2017. MAIN OUTCOME MEASURES:Patients were divided into fallers and non-fallers, depending on the experience of one or more falls in the preceding 12 months. Residual vestibular function on caloric testing, rotatory chair testing, video head impulse test (vHIT) and cervical vestibular evoked myogenic potentials (cVEMP) was evaluated as a predictive factor for falls. Furthermore, hearing function (speech perception in noise (SPIN)), sound localization performance, etiology, disease duration, sport practice, scores on the Dizziness Handicap Inventory (DHI) and the Oscillopsia Severity Questionnaire (OSQ) were compared between fallers and non-fallers. RESULTS:Forty-five (39%) patients reported falls. In a sub-analysis in the patients recruited at UZA (n = 69), 20% experienced three or more falls and three patients (4%) suffered from severe fall-related injuries. The DHI score and the OSQ score were significantly higher in fallers. Residual vestibular function, SPIN, sound localization performance, etiology, disease duration, age and sport practice did not differ between fallers and non-fallers. CONCLUSIONS:Falls and (severe) fall-related injuries are frequent among BV patients. A DHI score > 47 and an OSQ score > 27.5 might be indicative for BV patients at risk for falls, with a sensitivity of 70% and specificity of 60%. Residual vestibular function captured by single vestibular tests (vHIT, calorics, rotatory chair, cVEMP) or by overall vestibular function defined as the number of impaired vestibular sensors are not suitable to distinguish fallers and non-fallers in a BV population.
Project description:The vestibular system is involved in gaze stabilization and standing balance control. However, it is unclear whether vestibular dysfunction affects both processes to a similar extent. Therefore, the objective of this study was to determine how the reliance on vestibular information during standing balance control is related to gaze stabilization deficits in patients with vestibular dysfunction. Eleven patients with vestibular dysfunction and twelve healthy subjects were included. Gaze stabilization deficits were established by spontaneous nystagmus examination, caloric test, rotational chair test, and head impulse test. Standing balance control was assessed by measuring the body sway (BS) responses to continuous support surface rotations of 0.5° and 1.0° peak-to-peak while subjects had their eyes closed. A balance control model was fitted on the measured BS responses to estimate balance control parameters, including the vestibular weight, which represents the reliance on vestibular information. Using multivariate analysis of variance, balance parameters were compared between patients with vestibular dysfunction and healthy subjects. Robust regression was used to investigate correlations between gaze stabilization and the vestibular weight. Our results showed that the vestibular weight was smaller in patients with vestibular dysfunction than in healthy subjects (<i>F</i>?=?7.67, <i>p</i>?=?0.011). The vestibular weight during 0.5° peak-to-peak support surface rotations decreased with increasing spontaneous nystagmus eye velocity (??=?-0.82, <i>p</i>?<?0.001). In addition, the vestibular weight during 0.5° and 1.0° peak-to-peak support surface rotations decreased with increasing ocular response bias during rotational chair testing (??=?-0.72, <i>p</i>?=?0.02 and ??=?-0.67, <i>p</i>?=?0.04, respectively). These findings suggest that the reliance on vestibular information during standing balance control decreases with the severity of vestibular dysfunction. We conclude that particular gaze stabilization tests may be used to predict the effect of vestibular dysfunction on standing balance control.
Project description:The purpose of this study was to prove the hypothesis that caloric response in Ménière's disease (MD) is reduced by hydropic expansion of the vestibular labyrinth, not by vestibular hypofunction, by evaluating the correlation morphologically using an intravenous Gadolinium (IV-Gd) inner ear MRI. In study I, the prevalence of abnormal video Head Impulse Test (vHIT) results among the patients with definite unilateral MD (n = 24) and vestibular neuritis (VN) (n = 22) were investigated. All patients showed abnormal canal paresis (CP) (> 26%) on caloric tests. The prevalence of abnormal vHIT in patients with abnormal CP was significantly lower in MD patients (12.5%) than that in VN patients (81.8%) (p < 0.001). In study II, morphological correlation between caloric tests and vestibular hydrops level was evaluated in unilateral MD patients (n = 16) who had normal vHIT results. Eleven patients (61%) had abnormal CP. After taking the images of IV-Gd inner ear MRI, the vestibular hydrops ratio (endolymph volume/total lymph volume = %VH) was measured. In addition, the relative vestibular hydrops ratio (%RVH = (%VHaffected ear-%VHunaffected ear) / (%VHaffected ear + %VHunaffected ear)) was calculated. Each ratio (%VH and %RVH) was compared with average peak slow phase velocity (PSPV) and CP, respectively. In the MD patients, %VH of the affected ear correlated significantly with mean PSPV on the same side (rs = -0.569, p = 0.024), while %RVH correlated significantly with CP (rs = 0.602, p = 0.014). In most MD patients (87.5%) compared to VN patients, vHIT results were normal even though the caloric function was reduced. In addition, the reduced caloric function with normal vHIT was related to the severity of the vestibular hydrops measured by the IV-Gd inner ear MRI. These findings concluded that the abnormal caloric tests with normal vHIT in MD indicated severe endolymphatic hydrops rather than vestibular hypofunction.
Project description:<h4>Objective</h4>To determine the accuracy of the bedside head impulse test (bHIT) by direct comparison with results from the quantitative head impulse test (qHIT) in the same subjects, and to investigate whether bHIT sensitivity and specificity changes with neuro-otological training.<h4>Methods</h4>Video clips of horizontal bHIT to both sides were produced in patients with unilateral and bilateral peripheral vestibular deficits (n = 15) and in healthy subjects (n = 9). For qHIT, eye and head movements were recorded with scleral search coils on the right eye and the forehead. Clinicians (neurologists or otolaryngologists) with at least 6 months of neuro-otological training ("experts": n = 12) or without this training ("non-experts": n = 45) assessed video clips for ocular motor signs of vestibular deficits on either side or of normal vestibular function.<h4>Results</h4>On average, bHIT sensitivity was significantly (t test: p<0.05) lower for experts than for non-experts (63% vs 72%), while bHIT specificity was significantly higher for experts than non-experts (78% vs 64%). This outcome was a consequence of the experts' tendency to accept bHIT with corresponding borderline qHIT values as still being normal. Fitted curves revealed that at the lower normal limit of qHIT, 20% of bHIT were rated as deficient by the experts and 37% by the non-experts.<h4>Conclusions</h4>When qHIT is used as a reference, bHIT sensitivity is adequate and therefore clinically useful in the hands of both neuro-otological experts and non-experts. We advise performing quantitative head impulse testing with search coils or high speed video methods when bHIT is not conclusive.
Project description:Fabry disease (FD) is an X-linked lysosomal storage disease, with multisystemic glycosphingolipids deposits. Neuro-otological involvement leading to hearing loss and vestibular dysfunctions has been described, but there is limited information about the frequency, site of lesion, or the relationship with peripheral neuropathy. The aim was to evaluate the presence of auditory and vestibular symptoms, and assess neurophysiological involvement of the VIII cranial nerve, correlating these findings with clinical and neurophysiological features of peripheral neuropathy. We studied 36 patients with FD with a complete neurological and neuro-otological evaluation including nerve conduction studies, quantitative sensory testing (to evaluate small fiber by warm and cold threshold detection and cold and heat pain), vestibular evoked myogenic potentials, videonistagmography, audiometry and brainstem auditory evoked potentials. Neuro-otologic symptoms included hearing loss (22.2%), vertigo (27.8%) or both (25%). An involvement of either cochlear or vestibular function was identified in most patients (75%). In 70% of our patients the involvement of both cochlear and vestibular function could not be explained by a neural or vascular mechanism. Small fiber neuropathy was identified in 77.7%. There were no significant associations between neuro-otological and QST abnormalities. Neuro-otologic involvement is frequent and most likely under-recognized in patients with FD. It lacks a specific neural or vascular pattern, suggesting multi-systemic, end organ damage. Small fiber neuropathy is an earlier manifestation of FD, but there is no correlation between the development of neuropathy and neuro-otological abnormalities.
Project description:<h4>Objective</h4>Cold and warm water ear irrigation, also known as bithermal caloric testing, has been considered for over 100 years the 'Gold Standard' for the detection of peripheral vestibular hypofunction. Its discovery was awarded a Nobel Prize. We aimed to investigate the diagnostic accuracy of Caloric Testing when compared to the video head impulse test (vHIT) in differentiating between vestibular neuritis and vestibular strokes in acute dizziness.<h4>Design</h4>Prospective cross-sectional study (convenience sample).<h4>Setting</h4>All patients presenting with signs of an acute vestibular syndrome at the emergency department of a tertiary referral center.<h4>Participants</h4>One thousand, six hundred seventy-seven patients were screened between February 2015 and May 2020 for Acute Vestibular Syndrome (AVS), of which 152 met the inclusion criteria and were enrolled. Inclusion criteria consisted of a state of continuous dizziness, associated with nausea or vomiting, head-motion intolerance, new gait or balance disturbance and nystagmus. Patients were excluded if they were younger than 18 years, if symptoms lasted < 24 h or if the index ED visit was > 72 h after symptom onset. Of the 152 included patients 85 completed testing. We assessed 58 vestibular neuritis and 27 stroke patients.<h4>Main outcome measures</h4>All patients underwent calorics and vHIT followed by a delayed MRI which served as a gold standard for vestibular stroke confirmation.<h4>Results</h4>The overall sensitivity and specificity for detecting stroke with a caloric asymmetry cut-off of 30.9% was 75% and 86.8%, respectively [negative likelihood ratio (NLR) 0.29] compared to 91.7% and 88.7% for vHIT (NLR 0.094). Best VOR gain cut-off was 0.685. Twenty-five percent of vestibular strokes were misclassified by calorics, 8% by vHIT.<h4>Conclusions</h4>Caloric testing proved to be less accurate than vHIT in discriminating stroke from vestibular neuritis in acute dizziness. Contrary to classic teaching, asymmetric caloric responses can also occur with vestibular strokes and might put the patient at risk for misdiagnosis. We, therefore, recommend to abandon caloric testing in current practice and to replace it with vHIT in the acute setting. Caloric testing has still its place as a diagnostic tool in an outpatient setting.
Project description:<h4>Background and purpose</h4>Strokes can be distinguished from benign peripheral causes of acute vestibular syndrome using bedside oculomotor tests (head impulse test, nystagmus, test-of-skew). Using head impulse test, nystagmus, test-of-skew is more sensitive and less costly than early magnetic resonance imaging for stroke diagnosis in acute vestibular syndrome but requires expertise not routinely available in emergency departments. We sought to begin standardizing the head impulse test, nystagmus, test-of-skew diagnostic approach for eventual emergency department use through the novel application of a portable video-oculography device measuring vestibular physiology in real time. This approach is conceptually similar to ECG to diagnose acute cardiac ischemia.<h4>Methods</h4>Proof-of-concept study (August 2011 to June 2012). We recruited adult emergency department patients with acute vestibular syndrome defined as new, persistent vertigo/dizziness, nystagmus, and (1) nausea/vomiting, (2) head motion intolerance, or (3) new gait unsteadiness. We recorded eye movements, including quantitative horizontal head impulse testing of vestibulo-ocular-reflex function. Two masked vestibular experts rated vestibular findings, which were compared with final radiographic gold-standard diagnoses. Masked neuroimaging raters determined stroke or no stroke using magnetic resonance imaging of the brain with diffusion-weighted imaging obtained 48 hours to 7 days after symptom onset.<h4>Results</h4>We enrolled 12 consecutive patients who underwent confirmatory magnetic resonance imaging. Mean age was 61 years (range 30-73), and 10 were men. Expert-rated video-oculography-based head impulse test, nystagmus, test-of-skew examination was 100% accurate (6 strokes, 6 peripheral vestibular).<h4>Conclusions</h4>Device-based physiological diagnosis of vertebrobasilar stroke in acute vestibular syndrome should soon be possible. If confirmed in a larger sample, this bedside eye ECG approach could eventually help fulfill a critical need for timely, accurate, efficient diagnosis in emergency department patients with vertigo or dizziness who are at high risk for stroke.
Project description:Previous research suggested that panic disorder with agoraphobia is associated with abnormalities on vestibular and balance function tests. The purpose of this study was to further examine psychiatric correlates of vestibular/balance dysfunction in patients with anxiety disorders and the specific nature of the correlated vestibular abnormalities. The psychiatric variables considered included anxiety disorder versus normal control status, panic disorder versus non-panic anxiety disorder diagnosis, presence or absence of comorbid fear of heights, and degree of space and motion discomfort (SMD). The role of anxiety responses to vestibular testing was also re-examined.104 subjects were recruited: 29 psychiatrically normal individuals and 75 psychiatric patients with anxiety disorders. Anxiety patients were assigned to four subgroups depending on whether or not they had panic disorder and comorbid fear of heights. SMD and anxiety responses were measured by questionnaires. Subjects were examined for abnormal unilateral vestibular hypofunction on caloric testing indicative of peripheral vestibular dysfunction, asymmetric responses on rotational testing as an indicator of an ongoing vestibular imbalance and balance function using Equitest dynamic posturography as an indicator of balance control. Logistic regression was used to establish the association between the psychiatric variables and vestibular or balance test abnormalities.Rotational test results were not significantly related to any of the psychiatric variables. The presence of either panic attacks or fear of heights increased the probability of having caloric hypofunction in a non-additive fashion. SMD and anxiety responses were independently associated with abnormal balance. Among specific posturography conditions, the association with SMD was significant for a condition that involved the balance platform tilting codirectionally with body sway, suggesting an abnormal dependence on somatosensory cues in the control of balance.In patients with anxiety disorders, higher SMD is indicative of somatosensory dependence in the control of balance. The absence of both panic and fear of heights reduces the probability of having peripheral vestibular dysfunction. Future research should examine if vestibular rehabilitation can be of value for patients with anxiety disorders complicated by SMD.
Project description:Vestibular neuritis (VN) is the most common cause of acute prolonged spontaneous vertigo, and is characterized by acute unilateral vestibular hypofunction, probably due to inflammation of the vestibular nerve. VN is diagnosed at the bedside when there is spontaneous horizontal-torsional nystagmus beating away from the side of the lesion, abnormal head impulse tests for the semicircular canals involved on the lesion side, and when other neurological symptoms and signs are absent. Here, as a neuro-otologist, I describe my experience during an attack of VN and discuss how it may help physicians to better understand why and what a patient feels during attacks of vertigo.