Search-coil head-thrust and caloric tests in Ménière's disease

Impact of endolymphatic hydrops on the function of the horizontal canal during caloric stimulation in Ménière's disease

PURPOSE

When a dizzy patient with episodic vertigo has an abnormal caloric and a normal video head impulse test (vHIT), this caloric-vHIT dissociation provides vital information for a diagnosis of Ménière's disease (MD). Endolymphatic hydrops (EH), a histological marker of MD, is hypothesized to be involved in the caloric-vHIT dissociation in MD through hydropic duct distension of the horizontal semicircular canal (SC). This study was designed to determine the impact of EH on the function of horizontal SC during caloric stimulation.

METHODS

Caloric test and vHIT were used to evaluate the function of horizontal SC every six months, annual magnetic resonance imaging (MRI) was used to evaluate the degree of EH size in the vestibule, and monthly vertigo and hearing evaluation was done for 12 months. EH shrinkage was defined as the size change of vestibular EH from significant to none.

RESULTS

Among 133 MD patients evaluated for eligibility, 67 patients with caloric-vHIT dissociation entered the study. Fifteen participants had EH shrinkage (G-I), while 52 participants had no remarkable EH change (G-II). Average values (IQR) of the maximum slow phase velocity in G-I and G-II were 29.6 (13.0-34.0) and 25.9 (17.3-31.3), respectively, at baseline, 26.1 (9.0-38.0) and 23.6 (18.0-28.3) at 12 months. Two-factor repeated-measures ANOVA showed no significant differences between the groups (P = 0.486). The values of vestibulo-ocular reflex gain of the horizontal SC in G-I and G-II remained above 0.8 during the study period.

CONCLUSIONS

EH detected by MRI shows limited correlation with caloric stimulation results.

Vestibular dysfunction in lateral semicircular canal dysplasia

Introduction

Lateral semicircular canal (LSCC) dysplasia is the most common inner ear malformation. The severity of dysplasia can appear in various spectrums, from a short and broad LSCC with normal or small-sized central bony island (CBI) to a single fluid-filled cavity confluent with the vestibule without CBI. However, reports on the association between LSCC dysplasia and the loss of vestibular function are still lacking. In this study, the results of vestibular function tests [caloric test and video-head impulse test (vHIT)] in patients with LSCC dysplasia were analyzed and compared between groups with and without CBI.

Methods

This study retrospectively enrolled 17 patients (23 ears) who had LSCC dysplasia following computed tomography or magnetic resonance imaging and underwent vestibular function tests.

Results

LSCC dysplasia was observed unilaterally in 11 patients and bilaterally in six patients. Nine of 23 ears had CBIs, and 14 ears had no CBI. Three of 17 patients experienced dizziness. Abnormal caloric tests were detected in 11 of the 16 patients who underwent the caloric tests (69%); in contrast, 11 of 12 patients who underwent the vHIT (92%) had normal LSCC vestibulo-ocular reflex (VOR) gain on vHIT. A significant correlation was found between the maximum slow-phase velocity of the caloric test and LSCC VOR gain of the vHIT (correlation coefficient 0.792, p = 0.004). The CBI-absent group showed significantly lower SPV and LSCC VOR gains than the CBI-present group (p = 0.001 and 0.004, respectively).

Discussion

LSCC dysplasia impairs VOR function, especially in the absence of CBI.

The value of saccade metrics and VOR gain in detecting a vestibular stroke

OBJECTIVE

A normal video Head Impulse Test is the gold standard in the emergency department to rule-in patients with an acute vestibular syndrome and a stroke. We aimed to compare the diagnostic accuracy of vHIT metrics regarding the vestibulo-ocular reflex gain and the corrective saccades in detecting vestibular strokes.

METHODS

Prospective cross-sectional study (convenience sample) of patients presenting with acute vestibular syndrome in the emergency department of a tertiary referral centre between February 2015 and May 2020. We screened 1677 patients and enrolled 76 patients fulfilling the inclusion criteria of acute vestibular syndrome. All patients underwent video head impulse test with automated and manual data analysis. A delayed MRI served as a gold standard for vestibular stroke confirmation.

RESULTS

Out of 76 patients, 52 were diagnosed with acute unilateral vestibulopathy and 24 with vestibular strokes. The overall accuracy of detecting stroke with an automated vestibulo-ocular reflex gain was 86.8%, compared to 77.6% for cumulative saccade amplitude and automatic saccade mean peak velocity measured by an expert and 71% for cumulative saccade amplitude and saccade mean peak velocity measured automatically. Gain misclassified 13.1% of the patients as false positive or false negative, manual cumulative saccade amplitude and saccade mean peak velocity 22.3%, and automated cumulative saccade amplitude and saccade mean peak velocity 28.9% respectively.

CONCLUSIONS

We found a better accuracy of video head impulse test for the diagnosis of vestibular strokes when using the vestibulo-ocular reflex gain than using saccade metrics. Nevertheless, saccades provide an additional and important information for video head impulse test evaluation. The automated saccade detection algorithm is not yet perfect compared to expert analysis, but it may become a valuable tool for future non-expert video head impulse test evaluations.

Mechanisms and Impact of Aminoglycoside-Induced Vestibular Deficits

PURPOSE

Acquired vestibulotoxicity from hospital-prescribed medications such as aminoglycoside antibiotics affects as many as 40,000 people each year in North America. However, there are no current federally approved drugs to prevent or treat the debilitating and permanent loss of vestibular function caused by bactericidal aminoglycoside antibiotics. This review will cover our current understanding of the impact of, and mechanisms underlying, aminoglycoside-induced vestibulotoxicity and highlight the gaps in our knowledge that remain.

CONCLUSIONS

Aminoglycoside-induced vestibular deficits have long-term impacts on patients across the lifespan. Additionally, the prevalence of aminoglycoside-induced vestibulotoxicity appears to be greater than cochleotoxicity. Thus, monitoring for vestibulotoxicity should be independent of auditory monitoring and encompass patients of all ages from young children to older adults before, during, and after aminoglycoside therapy.

Eye Movement Abnormalities During Different Periods in Patients with Vestibular Migraine

Purpose

The aim of this study was to assess abnormal eye movement signs during different periods, namely, ictal periods and symptom-free intervals, in patients with vestibular migraine.

Patients and Methods

We assessed oculomotor signs using videonystagmography in 90 patients with VM (40 during ictal periods and 50 during symptom-free intervals) according to validated diagnostic criteria.

Results

Abnormal saccades, smooth pursuit and optokinetic test results; spontaneous nystagmus; and positional nystagmus were all observed in vestibular migraine patients, and there was no significant difference between different periods. Positional nystagmus was the most common in both the ictal and asymptomatic periods (60% and 36%, respectively). Positional nystagmus was induced in a variety of positions during both periods, and the slow-phase velocity ranged from <2 to 10°/s. The duration of positional nystagmus was over 60s in most cases. Overall, central oculomotor dysfunctions occurred in 27.5% of patients during VM attacks and 4% of patients during symptom-free intervals; this difference was statistically significant (p = 0.002).

Conclusion

In patients with VM, abnormal oculomotor signs can be found during both vertigo attacks and asymptomatic intervals. Positional nystagmus is the most common of these abnormalities and can be induced in different positions. The amplitude of these patients' positional nystagmus tends to be low, and the duration tends to be long. Observing changes in eye movements by videonystagmography may be helpful in the diagnosis of VM.

Case report: MRI changes of the inner ear in an MD patient with suspected immune dysfunction

Objectives

The primary objective of this study was to present the progressive changes from labyrinthitis to endolymphatic hydrops (EH) demonstrated in the inner ear MRI of a patient with MD and suspected immune dysfunction.

Patient

This 31-year-old male was diagnosed with MD and suspected autoimmune diseases.

Interventions

Immunosuppressants and biological agents.

Main outcomes measures

Inner ear MRI images.

Results

Changes in the patient's progress revealed that inner ear immune and inflammatory changes might induce EH, which may eventually turn into MD.

Conclusion

This case is the first documented case of MRI revealing progressive changes from inflammatory response to endolymphatic hydrops in the inner ear. It shows the correlation between MD and inflammation visually. It is of great significance to reveal the pathogenesis of MD to further assist in the guidance of treatment decision making.

Otolith Membrane Herniation, not Semicircular Canal Duct Dilation, Is Associated with Decreased Caloric Responses in Ménière's Disease

Ménière's disease (MD) is a debilitating disorder with unclear pathophysiology whose diagnosis often relies on clinical judgment rather than objective testing. To complicate matters further, a dissociation has emerged between two vestibular function tests commonly used in patients with MD to examine the same end-organ (the semicircular canals): the caloric test and video head impulse testing (vHIT). Caloric responses are often abnormal, while vHIT results remain normal. Explaining this dissociation could reveal novel insights into MD pathophysiology. Here, we conduct a histopathological study using temporal bone specimens (N = 58, 21 MD-affected ears and 37 age-matched controls) and their clinical testing data to examine current hypotheses aimed at this dissociation. We find otolith membrane herniation into the horizontal semicircular canal in 69% of MD ears, with 90% of these ears demonstrating a diminished caloric response. No ears with a normal response had this herniation. Moreover, we evaluated the semicircular canals for endolymphatic hydrops, which had been hypothesized to contribute to the dissociation, and found no evidence of duct dilation/hydrops. We did, however, note a potentially novel morphologic finding-smaller bony labyrinth cross-sectional diameters/areas in some MD ear canals compared to controls, suggesting relative size of the membranous duct to the bony canal rather than absolute size may be of importance. Taken together, this study refines hypotheses on the vestibular test dissociation in MD, holding diagnostic implications and expanding our understanding of the mechanisms underlying this enigmatic disease.

Saccades of video head impulse test in Meniere's disease and Vestibular Migraine: What can we learn from?

Background

Saccades are often observed on video head impulse tests (vHIT) in patients with Meniere's Disease (MD) and Vestibular Migraine (VM). However, their saccadic features are not fully described.

Objective

This study aims to identify the saccades characteristics of MD and VM.

Methods

75 VM patients and 103 definite unilateral MD patients were enrolled in this study. First raw saccades were exported and analyzed. The VM patients were divided into left and right based on their ears, while the MD patients were separated into affected and unaffected subgroups based on their audiograms and symptoms.

Results

The MD patients have more saccades on the affected side (85% vs. 69%), and saccade velocity is more consistent than the contralateral side (shown by the coefficient of variation). The saccades occurrence rates on both sides are similar in VM (77% vs. 76%), as are other saccadic parameters. The MD patients have more significant inter-aural differences than the VM patients, manifested in higher velocity (p-value 0.000), earlier arriving (p-value 0.010), and more time-domain gathered (p-value 0.003) on the affected side.

Conclusions

Bilateral saccades are commonly observed in MD and VM. In contrast to MD, saccades on VM are subtle, scattered, and late-arrived. Furthermore, the MD patients showed inconsistent saccadic distribution with more velocity-uniform saccades on the affected side.

Dissociation between Caloric and Video Head Impulse Tests in Dizziness Clinics

Vestibular assessment tests such as the video head impulse test (vHIT) for the horizontal semicircular canal, and caloric test (Cal), both evaluate horizontal canal function. One would assume that the outcomes for these tests should lead to concordant results, yet several studies have suggested that dissociation can occur in certain pathological conditions. As this topic remains inconclusive, this review aims to analyze the scientific evidence regarding the patterns of hypofunction observed in vHIT and Cal in different otoneurological diseases. A comprehensive review of the literature regarding dissociation between these tests in common neurotological diseases was carried out. Articles were analyzed when data for vHIT and Cal were described in a way that it was possible to calculate discordance rates; both retrospective and prospective studies were analyzed. In this review, the discordance rates were as follows: 56% in Ménière’s disease, 51.5% in vestibular migraine, 37.2% in vestibular schwannoma, and 20.8% in vestibular neuritis. These results highlight the benefit of using both Cal and vHIT, and that they are complementary tests.

Objective measurement of HINTS (Head Impulse, Nystagmus, Test of Skew) in peripheral vestibulopathy

OBJECTIVE

To evaluate how often the positive sign of HINTS (Head-Impulse, Gaze Evoked Nystagmus, Test of Skew) appears in patients with acute peripheral vestibular lesion, HINTS findings were quantitatively measured and analyzed in patients with peripheral vestibulopathy accompanying spontaneous nystagmus.

METHODS

HINTS was evaluated in 14 vertigo patients with spontaneous nystagmus. Horizontal vestibulo-ocular reflex (VOR) gain was measured using the video head impulse test (vHIT). To evaluate gaze-evoked nystagmus (GEN), slow-phase velocities at different points of lateral gaze were measured and plotted, then the slope and its inverse value, the neural integrator time constant, were calculated. Skew deviation was tested using anaglyph filters to simulate the alternate cover test, and the degree and latency of vertical eyeball deviation were measured. The ABCD2 score was calculated to evaluate the risk of stroke.

RESULTS

Among 13 patients of peripheral vestibulopathy, 7 showed positive signs in HINTS (normal vHIT: 5, direction-changing GEN: 0, skew deviation: 3). One patient with a cerebellopontine angle tumor presented with both a peripheral and central pattern and showed positive HINTS findings (presence of direction-changing GEN). The mean VOR gain of patients with abnormal vHIT was 0.58±0.29 and 1.10±0.11 in the affected and contralateral side, respectively, while those in patients with normal vHIT were 1.04±0.21 and 1.13±0.12, respectively. The neural integrator time constant calculated from the mean slope of horizontal slow-phase velocity according to horizontal eye position was 42.9 s. The mean vertical eyeball deviation of patients with positive skew was 2.14±1.18° while uncovering the eye on the affected side, and -1.97±1.59° while uncovering the eye on the unaffected side. The median ABCD2 score of 14 patients was 2 (range, 1-3).

CONCLUSIONS

HINTS findings were objectively measured in vertigo patients with spontaneous nystagmus. Although positive findings of HINTS have been recognized as a central sign, 54% (7/13) of cases with peripheral vestibulopathy showed positive HINTS signs. HINTS results should be interpreted carefully considering that a substantial proportion of peripheral vestibulopathy shows a positive HINTS sign.

Differential Involvement of Lateral Semicircular Canal and Otolith Organs in Common Vestibular Disorders

Semicircular canal and otolith functions came to be evaluated recently, but comprehensive and comparative analysis of canal and otolith dysfunction in common vestibular disorders is lacking. We aimed to analyze the abnormal rates of canal and otolith function in common vestibular disorders. We enrolled 302 patients who were managed for 2 months in a dizziness clinic. Results of caloric, video head impulse test (vHIT), and cervical and ocular vestibular evoked myogenic potential (cVEMP and oVEMP) tests were analyzed and compared among various diagnoses. Vestibular disorders diagnosed included recurrent vestibulopathy (RV, 27%), vestibular migraine (VM, 21%), benign paroxysmal positional vertigo (BPPV, 17%), Meniere's disease (MD, 11%), vestibular neuritis (VN, 10%), orthostatic dizziness (7%), and central lesions (3%). Lateral canal dysfunction was found most in VN (100%) and less commonly in definite MD (75%), RV (46%) and definite VM (29%). Abnormal caloric results were more common than abnormal vHIT in all disorders. Otolith dysfunction was found more frequently than lateral canal dysfunction in most vestibular disorders except VN. An abnormal cVEMP was more frequent in definite MD than the other disorders. Isolated otolith dysfunction without lateral canal dysfunction was the most found in BPPV, followed by definite VM, RV, and definite MD in decreasing order. Various patterns of involvement in canal and otoliths were revealed in vestibular disorders, suggesting different pathogenesis.

Clinical, oculographic and vestibular test characteristics of Ménière's disease

Seventy Ménière's disease (MD) patients with spontaneous vertigo (100%), unilateral aural fullness (57.1%), tinnitus (78.6%), and subjective hearing loss (75.7%) self-recorded nystagmus during their episodes of vertigo using portable video oculography goggles. All demonstrated ictal spontaneous nystagmus, horizontal in 94.3% (n = 66) and vertical in 5.7% (n = 4), with a mean slow-phase velocity (SPV) of 42.8 ± 31.1°/s (range 5.3-160.1). Direction reversal of spontaneous horizontal nystagmus was captured in 58.6%, within the same episode in 34.3%, and over different days in 24.3%. In 18.6%, we observed ipsiversive then contraversive nystagmus, and in 12.9% contraversive to ipsiversive direction reversal. Ictal nystagmus SPV (42.8 ± 31.1°/s) was significantly faster than interictal (1.4 ± 3.1°/s, p < 0.001, CI 34.277-48.776). Compared to age-matched healthy controls, interictal video head impulse test gains in MD ears were significantly lower, cumulative and first saccade (S1) amplitudes were significantly larger, and S1 peak velocities were significantly faster (p = 0.038/0.019/0.008/ < 0.001, CI 0.002-0.071/0.130-1.444/0.138-0.909/14.614-41.506). Audiometry showed asymmetrically increased thresholds in 100% of MD ears (n = 70). Significant caloric, air-conducted (AC) cervical vestibular-evoked myogenic potential (VEMP), and AC ocular VEMP asymmetries were found in 61.4, 37.9, and 44.4% of patients (MD ear reduced). Transtympanic electrocochleography tested in 36 ears (23 patients) showed 81.8% of MD ears had a positive result for hydrops (either a summating potential at 1/2 kHz < - 6 µV, or an SP/AP ratio > 40%). Using ictal nystagmus findings of SPV > 12°/s, and a caloric canal paresis > 25%, we correctly separated a diagnosis MD from Vestibular Migraine with a sensitivity and specificity of 95.7% and 85.1% (CI 0.89-0.97).

Exploratory saccades data analysis of video head impulse test in Different Meniere's Disease Stages

BACKGROUND

Unapparent saccades in video head impulse test (vHIT) are usually present in MD patients but tend to be ignored by the clinician. The result of vHIT is constantly questioned in MD patients due to a lack of uniform metrics. A more effective indicator is needed for indicating MD's pathological progress.

OBJECTIVES

To get a comprehensive understanding of the nature and usability of saccades in different MD stages.

METHODS

118 patients diagnosed with unilateral MD were recruited in this study. Patient history, audiological examination, caloric test, vHIT were performed. We proposed 'raw saccades' to represent all showed wave peaks behind the head peak and named saccades by their appearance sequence: 1st saccade, 2nd saccade and 3rd saccade. An exploratory saccade analysis was executed to investigate the effectiveness of saccade attributes in identifying MD stages.

RESULTS

MD patients have greater detectable 1st saccade than PR score as well as 2nd saccade. The time and velocity of the 1st saccade show high interaural variability (p = 0.028, p = 0.000 respectively). No statistical difference concerning the vHIT gain, PR score and 2nd saccade among stages could be recognized on both affected and contralateral sides. Multiple comparisons show the affected 1st saccade velocity and affected 1st saccade absolute velocity have stage-difference. At late stages (3&4), the affected 1st saccade is manifested as a speed increase, and this measure shows a relatively high correlation with MD stages compared to other vestibular indicators.

CONCLUSION

The 1st saccade velocity on the affected side could indicate the MD disease process and severity.

Vertigo Associated With Cochlear Implant Surgery: Correlation With Vertigo Diagnostic Result, Electrode Carrier, and Insertion Angle

Objective: Vertigo is a common side effect of cochlear implant (CI) treatment. This prospective study examines the incidence of postoperative vertigo over time and aims to analyze influencing factors such as electrode design and insertion angle (IA). Study Design and Setting: This is a prospective study which has been conducted at a tertiary referral center (academic hospital). Patients: A total of 29 adults were enrolled and received a unilateral CI using one of six different electrode carriers, which were categorized into "structure-preserving" (I), "potentially structure-preserving" (II), and "not structure-preserving" (III). Intervention: Subjective vertigo was assessed by questionnaires at five different time-points before up to 6 months after surgery. The participants were divided into four groups depending on the time of the presence of vertigo before and after surgery. Preoperatively and at 6 months postoperatively, a comprehensive vertigo diagnosis consisting of Romberg test, Unterberger test, subjective visual vertical, optokinetic test, video head impulse test, and caloric irrigation test was performed. In addition, the IA was determined, and the patients were divided in two groups (<430°; ≥430°). Main Outcome Measures: The incidence of vertigo after CI surgery (group 1) was reported, as well as the correlation of subjective vertigo with electrode array categories (I-III) and IA. Results: Among the participants, 45.8% experienced new vertigo after implantation. Based on the questionnaire data, a vestibular origin was suspected in 72.7%. The results did not show a significant correlation with subjective vertigo for any of the performed tests. In group 1 with postoperative vertigo, 18% of patients showed conspicuous results in a quantitative analysis of caloric irrigation test despite the fact that the category I or II electrodes were implanted, which are suitable for structure preservation. Average IA was 404° for the overall group and 409° for group 1. There was no statistically significant correlation between IA and perceived vertigo. Conclusions: Though vertigo after CI surgery seems to be a common complication, the test battery used here could not objectify the symptoms. Further studies should clarify whether this is due to the multifactorial cause of vertigo or to the lack of sensitivity of the tests currently in use. The proof of reduced probability for vertigo when using atraumatic electrode carrier was not successful, nor was the proof of a negative influence of the insertion depth.

The spectrum of acute vestibular neuropathy through modern vestibular testing: A descriptive analysis

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Video head impulse testing and vestibular evoked myogenic potentials show that acute vestibular neuropathy is heterogeneous.

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Peripheral vestibular pathway vulnerability is approximately inversely correlated with its proportion of afferent fibers.

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Caloric testing, while useful, should no longer be considered the gold standard for diagnosing acute vestibular neuropathy.

Objective

Acute vestibular neuropathy (AVN), often referred to as vestibular neuritis, is a cranial neuropathy responsible for a significant proportion of cases of acute vertigo. This study describes the spectrum of lesion patterns in AVN as identified by video head impulse testing (vHIT) which assesses the high frequency vestibulo-ocular reflex function of the semicircular canals, and cervical and ocular vestibular evoked myogenic potentials (VEMPs) which assess otolith function.

Methods

We used vHIT and VEMPs to assess 35 patients with vestibular neuropathy in the acute stage.

Results

Unilateral superior division vestibular nerve involvement was the most common variant (57.1%), followed by unilateral superior and inferior division (28.5%), bilateral superior division (8.5%) and unilateral inferior division (5.7%). We observed a partial inverse correlation between the proportion of afferent fibers from an organelle, and the likelihood that the test of that organelle’s function will be abnormal.

Conclusion

vHIT and VEMPs provide more detailed characterization of lesion pattern in AVN than caloric testing.

Significance

Comparison of lesion patterns from neuro-physiological testing with what is known about the proportional distribution of afferent fibers from the vestibular end-organelles suggests a new, neuro-anatomically based insight regarding susceptibility of these pathways to AVN.

Clinical Prevalence of Enhanced Vestibulo-Ocular Reflex Responses on Video Head Impulse Test

OBJECTIVE

To measure and analyze the clinical and epidemiological characteristics of patients and healthy controls with enhanced eye velocity responses as well as evaluate their relationship with endolymphatic hydrops related diseases.

STUDY DESIGN

Cross-sectional clinical study.

SETTING

Tertiary hospital.

PARTICIPANTS

Three hundred sixty three participants allocated to patients (310) and healthy control (53) groups were collected on first time visit to neurotology unit.

INTERVENTION

Diagnostic.

MAIN OUTCOME MEASURES

Video head impulse test records, clinical diagnose, and variables and demographic data were used to get cross tables, a general linear model, diagnostic epidemiological parameters, and machine learning variable importance evaluation methods.

RESULTS

All the statistical tests revealed a significant association between enhanced vestibulo-ocular reflex (VOR) and diagnostic categories (p < 0.001). Chi-squared residual and machine learning analyses showed Menière's disease as the main associated diagnostic category, whereas the lowest residuals and gain values were found in the control group. Enhanced VOR as a diagnostic sign of Menière's disease had a sensitivity of 42.59% and a specificity of 86.32%, with an odds ratio of 4.68 (p < 0.001).

CONCLUSION

There is a significantly higher prevalence of enhanced VOR responses in patients with Menière's disease, central origin vertigo, otosclerosis, and vestibular migraine than in those with other neurotologic diseases and controls. Our study found that enhanced VOR are not pathognomonic of hydrops-related diseases and the diagnosis should not solely be based on these and instead take into context other clinical and examination findings.

Evolution in the Findings of Head-Impulse Tests During the Attacks of Menière's Disease

OBJECTIVE

To determine the vestibulo-ocular reflex (VOR) performance during the attacks of Menière's disease (MD) using video head-impulse tests (video-HITs) according to each ictal phase.

STUDY DESIGN

Retrospective case series review.

METHODS

We analyzed the results of video-HITs in 24 patients with unilateral definite MD during and between the attacks.

RESULTS

The head impulse gain of the VOR was usually normal (81%, 39 of the 48 semicircular canals [SCCs] in 16 patients) in the affected ear during the irritative or recovery phase, and did not differ from that for each SCC between the attacks (horizontal [HCs], p = 0.412; anterior [ACs], p = 0.920; posterior canals [PCs], p = 0.477). During the paretic phase, however, the head impulse gains of the VOR were equally normal (22/42, 52%) or decreased (20/42, 48%) for the affected ear (42 SCCs in 14 patients). The gains for the HCs were lower during the paretic phase than those between the attacks in the affected ear, while those for the ACs and PCs did not differ (HCs, p = 0.001; ACs, p = 0.158, PCs, p = 0.401). Covert saccades were more frequently observed even in the presence of normal VOR gains during the paretic phase as well.

CONCLUSION

During the attacks of MD, HITs are usually normal during the irritative/recovery phases, but become positive in more than a half of the patients during the paretic phase. This evolution in the ictal findings of HITs may reflect characteristic ictal vestibular discharges in MD and should be considered in evaluating patients with MD according to each ictal phase during the attacks.

Evidence of Large Vestibulo-Ocular Reflex Reduction in Patients With Menière Attacks

OBJECTIVE

To examine the high frequency horizontal vestibular ocular-reflex (hVOR) during acute attacks of vertigo in Menière's disease (MD).

STUDY DESIGN

Retrospective case series and literature review.

SETTING

Tertiary academic medical center.

PATIENTS

Patients with clinical diagnosis of unilateral "definite MD."

INTERVENTION

Review of medical records.

MAIN OUTCOME MEASURES

Spontaneous nystagmus and the dynamic hVOR gain change at different stages of an acute episode of MD attack.

RESULTS

We studied 10 vertigo attacks during the unique stages of the episode. During the acme stage of the attack, lower hVOR gain was recorded on the affected side (mean 0.48 ± 0.23), which was associated with a paralytic nystagmus (beating away from the affected ear). Additionally, the mean hVOR gain remained significantly (p < 0.05) reduced during each of the other stages of the attack as compared with the unaffected side and a control group. After the attack, mean hVOR gains normalized in the affected ear. Mean hVOR gain of the unaffected ear remained normal during all stages.

CONCLUSION

Vestibular function during an attack of MD is a dynamic process associated with fluctuation of the dynamic (hVOR gain) and static (spontaneous nystagmus) processes, which exist in parallel with the perception of vertigo. Our data support vHIT monitoring during an episode to provide objective and accurate evidence of the ear with active disease. This would be particularly useful for those patients with MD presentations of unreliable hearing or assisting to identify the ear to be treated in the case of bilateral MD.

Evolution of caloric responses during and between the attacks of Meniere's disease

Caloric tests are useful for disease surveillance of Meniere's disease (MD), although the interpretation of caloric tests remains controversial during the attacks of MD. Therefore, we aimed to characterize the findings of caloric tests during the attacks of MD. We analyzed the results of bithermal caloric tests during and between the attacks in 43 patients with unilateral definite MD. Evaluation was performed during the irritative/recovery phase in 22 and during the paretic phase in 26 patients. During the irritative/recovery phase, less than half of patients (10/22, 45%) showed a caloric asymmetry of more than 25%, lesser responses in the affected ear in six and in the healthy ear in the other four. In contrast, patients usually showed a caloric asymmetry of more than 25% during the paretic phase (19/26, 73%) with a decreased response almost always in the affected ear (18/19, 95%). Between the attacks, caloric asymmetry was found in less than half of the patients (20/43, 47%) with a decreased response almost always in the affected ear (19/20, 95%) when observed. The caloric asymmetry was less during the irritative/recovery phases than between the attacks (p = 0.007). In contrast, the caloric asymmetry was larger during the paretic phase than between the attacks (p = 0.041). The caloric asymmetry decreased during the irritative/recovery phases with an estimated mean difference of 34% (adjusted 95% CI 16-53%, p < 0.001) and 23% (adjusted 95% CI 8-38%, p = 0.002) compared to the paretic and interictal phases. Caloric responses fluctuate during and between the attacks of MD depending on the electrophysiologic status of the vestibular afferents. The results of caloric tests in MD, thus should be interpreted with consideration of each phase when the evaluation was done.

Benign recurrent vestibulopathy: MRI and vestibular tests results in a series of 128 cases

PURPOSE

Benign recurrent vestibulopathy is a recent entity, close to probable Meniere's disease and vestibular-migraine. So far, no study has systematically investigated the presence of endolymphatic hydrops of the lateral semicircular canal in benign recurrent vestibulopathy using magnetic resonance imaging. The aim of this study was to determine magnetic resonance imaging data and vestibular test results in patients with benign recurrent vestibulopathy.

METHODS

128 patients with benign recurrent vestibulopathy included since 2010 were retrospectively analyzed. Patients had magnetic resonance imaging with a delayed acquisition, audiogram, head shaking test, caloric-test, skull-vibration-induced-nystagmus-test, video-head- impulse-test, and vestibular evoked myogenic potential. Endolymphatic hydrops presence was classified into four categories: cochlear, saccular, lateral semicircular canal and association with saccule.

RESULTS

In benign reccurent vestibulopathy, 23% of cases showed an endolymphatic hydrops on magnetic resonance imaging, more frequently located in the lateral semicircular canal (59%) and related to the disease duration. The most often impaired tests were caloric-test (49%) with fluctuations of hypofunction in 67% and skull-vibration-induced-nystagmus-test (61%). No correlation between the caloric-test and the presence and location of the endolymphatic hydrops was observed.

CONCLUSION

In our series of benign reccurent vestibulopathy, a rare endolymphatic hydrops was most often observed for the lateral semicircular canal and correlated with the seniority of the pathology. Hydrops identified at the magnetic resonance imaging was not correlated with the caloric-test results. Skull-vibration-induced-nystagmus-test and caloric-test were the most often modified vestibular tests.

Vestibulo-ocular reflex tests may reflect unilateral Ménière disease progression: A cross-sectional study

Vestibular disorders can manifest several patterns of horizontal vestibulo-ocular reflex (VOR) impairment, which can be detected by caloric test and video head impulse test (vHIT). Several studies have examined the patterns of caloric-vHIT response in Ménière disease (MD). The purpose of this study was to investigate the diversity of caloric-vHIT response and its related factors in unilateral MD patients. We also explore the possibility of assessing the progression of unilateral MD by using the horizontal VOR tests.Ninety-eight patients with unilateral MD were enrolled and underwent a battery of audio-vestibular evaluations, including the pure tone audiogram, caloric test, and horizontal vHIT. Some patients received the electrocochleography and glycerol test. The combined results of caloric test and horizontal vHIT were categorized qualitatively into 4 patterns: Pattern I: normal caloric and vHIT responses; Pattern II: abnormal caloric and normal vHIT responses; Pattern III: normal caloric and abnormal vHIT response; and Pattern IV: abnormal caloric and vHIT responses. The abnormal caloric results were semi-quantitatively subdivided into sub-patterns as mild, moderate, and severe abnormality. The associations between these patterns/sub-patterns and related factors were analyzed.Pattern I was found in 35 cases (35.7%), Pattern II in 57 (58.2%), and Pattern IV in 6 (6.1%). No patient had Pattern III. No significant differences were found between the patterns/sub-pattern distribution and age, electrocochleography, and glycerol test results. Disease duration was not associated with the pattern distribution, while remained a relation with sub-pattern distribution. The pattern/sub-pattern distribution varied significantly across MD stages. The proportion of pattern II or pattern IV increased with the stage of unilateral MD.MD can manifest several patterns of horizontal VOR impairment, of which the impaired caloric response with normal vHIT is the most common pattern. With the progression of unilateral MD, the caloric-vHIT pattern tends to shift, which may reflect the deterioration of endolymphatic hydrops and vestibular hair cells impairments.

Sparse classification of discriminant nystagmus features using combined video-oculography tests and pupil tracking for common vestibular disorder recognition

Vertigo is a common sign related to a problem with the brain or vestibular system. Detection of ocular nystagmus can be a support indicator to distinguish different vestibular disorders. In order to get reliable and accurate real time measurements from nystagmus response, video-oculography (VOG) plays an important role in the daily clinical examination. However, vestibular diseases present a large diversity in their characteristics that leads to many complications for usual analysis. In this paper, we propose a novel automated approach to achieve both selection and classification of nystagmus parameters using four tests and a pupil tracking procedure in order to give reliable evaluation and standardized indicators of frequent vestibular dysfunction that will assist clinicians in their diagnoses. Indeed, traditional tests (head impulse, caloric, kinetic and saccadic tests) are applied to obtain clinical parameters that highlight the type of vertigo (peripheral or central vertigo). Then, a pupil tracking method is used to extract temporal and frequency nystagmus features in caloric and kinetic sequences. Finally, all extracted features from the tests are reduced according to their high characterization degree by linear discriminant analysis, and classified into three vestibular disorders and normal cases using sparse representation. The proposed methodology is tested on a database containing 90 vertiginous subjects affected by vestibular Neuritis, Meniere's disease and Migraines. The presented technique highly reduces labor-intensive workloads of clinicians by producing the discriminant features for each vestibular disease which will significantly speed up the vertigo diagnosis and provides possibility for fully computerized vestibular disorder evaluation.

Comparison of the video head impulse test results with caloric test in patients with Meniere's disease and other vestibular disorders

Background: The caloric test has been used to evaluate the semi-circular canal function for decades. In 2009, the video head impulse test (vHIT) was introduced, which can be used to evaluate the semi-circular canal function within a short time. Although both tests examine the semi-circular canal, the stimulation methods differ and it is unclear whether the vHIT is equivocal to the caloric test.Aims/objectives: This study aimed to discern the differences between the vHIT and caloric test.Material and methods: This study comprised 112 patients with vertigo who visited the vertigo/dizziness centre at our university hospital. Each of these patients underwent a caloric test and vHIT within the same day, and their results were compared. Additionally, an electrocochleography (EcoG) examination, glycerol test (G test), and MRI (performed 4 h after an intravenous gadolinium injection) were conducted to evaluate the influence of endolymphatic hydrops (EH) on the caloric test and vHIT results.Results: Differences in the caloric test and vHIT results, among those with and without EH, were observed in 66.7 and 35.3% of patients, respectively.Conclusions and significance: EH resulted in a difference in results between the caloric test and vHIT. Activated hair cell type may also be implicated.

A New Proposal for Severity Evaluation of Menière's Disease by Using the Evidence From a Comprehensive Battery of Auditory and Vestibular Tests

To date, no widely accepted criteria exist to quantify the severity of Menière's disease (MD) by using vestibular tests. This study aimed to compare association of hearing loss and vertigo severity with association of accurate assessments of vestibular function and the vertigo severity. The severity of vertigo was documented by a comprehensive medical history with number of vertigo attacks in the past 6 months and a Dizziness Handicap Inventory (DHI) questionnaire. The involvement of vestibular organs was verified by audio-vestibular tests in 80 definite MD patients. Correlations between DHI scores, number of vertigo attacks in the past 6 months, audio-vestibular function, and the number of involved vestibular end organs were evaluated. We show that there are no significant differences in either severity of vertigo or laboratory results across the degree of hearing loss. Furthermore, the number of involved vestibular end organs was significantly correlated with vestibulo-ocular reflex gain in anterior and posterior canal video head impulse test (vHIT), interaural asymmetry ratio in vestibular-evoked myogenic potentials (VEMPs), and number of vertigo attacks in the past 6 months and DHI score. The vestibulo-ocular reflex gain in the rotatory chair test (RCT) was significantly correlated with the DHI Physical scores and number of involved vestibular end organs at 0.08 Hz. These results indicate that hearing loss is a poor indicator of vertigo severity in MD whereas the number of involved vestibular end organs may serve as an objective measure for MD progress. A battery of vestibular tests targeting different sensor organs is a complementary method for evaluating inner ear deficits and may aid in "grading" the severity of MD.

Comparison of the results of caloric and video head impulse tests in patients with Meniere's disease and vestibular migraine

PURPOSE

To compare the results of video head impulse test (vHIT) and caloric testing (CT) in patients with vestibular migraine (VM) and Ménière's disease (MD) and to investigate the relationship between these two tests.

METHODS

Patients with definite unilateral MD and VM were included in the study. All patients underwent both vHIT and CT. The vestibulo-ocular reflex (VOR) gains of lateral semicircular canals and saccadic waves in vHIT and the canal paresis factor for the CT were examined.

RESULTS

CT was found abnormal in 39 (66.1%) patients with MD and in 17 (34%) patients with VM, while abnormal gain of the lateral canal was obtained in 23 MD (39%) patients and 9 (18%) VM patients. In all, 11.9% of patients with an abnormal vHIT had a normal CT, whereas 33.9% of those with an abnormal CT had a normal vHIT.

CONCLUSION

Loss of VOR detected by caloric testing is more common and severe in MD than VM. Although vHIT is useful and can give complementary information, vestibular testing with the caloric test still seems more sensitive for detecting hVOR pathology.

Diagnostic value of refixation saccades in the Video Head Impulse Test (vHIT) in unilateral definite Meniere's disease

Introduction: We currently interpret the video Head Impulse Test (vHIT) results mainly based on the gain value.Aim: The purpose of this study is to evaluate vHIT results for both gain and re-fixation saccades on unilateral definite Meniere's disease (MD) subjects in comparison with normal healthy subjects.Materials and Methods: Forty unilateral definite MD subjects and age-matched healthy subjects were recruited. Pure tone audiometry, the caloric test, and the vHIT test were performed on MD subjects. The vHIT test was performed on healthy subjects.Results: The velocity regression gain (VRG) of the affected ear in patients with MD is significantly lower than of those in healthy subjects. The total percentage of refixation saccades is significantly higher in patients with MD when compared to healthy subjects. VRG values were not well-correlated with the percentage of refixation saccades. VRG asymmetry values are also not well-correlated with the percentage of unilateral canal weakness. A moderately stronger correlation between the percentage of refixation saccades and percentage of unilateral canal weakness, with an r² of 0.474.Conclusions: The present study suggests that while VRGs are still a diagnostic parameter of detecting MD, the presence of refixation saccades can also have diagnostic value, especially with normal VRGs, in detecting MD.

Towards a new staging of Ménière's disease: a vestibular approach

Ménière’s disease (MD) is characterised by intermittent episodes of vertigo, fluctuating sensorineural hearing loss, tinnitus and aural pressure. Histopathologically, endolymphatic hydrops are seen initially in the cochlear duct and saccule, and with progression of the disease subsequent involvement of the utricle and semicircular canals occurs. The aims of this study are: 1) to assess the function of the saccule, utricle and three semicircular canals using cervical vestibular evoked myogenic potential (cVEMP), ocular VEMP (oVEMP) and video head impulse test (vHIT) in Ménière’s patients, and 2) to correlate the findings with the different stages of MD. Forty patients diagnosed with unilateral definite MD according to the AAO-HNS (1995) criteria were tested. They were divided into four subgroups according to the stage of MD using the average of 500, 1000, 2000 and 3000 Hz pure tone thresholds of the worst documented audiogram during the 6-month interval before examination. A control group of 40 healthy age-matched adults was equally divided into four corresponding subgroups according to their pure tone average. 500 and 1000 Hz tone burst air conduction cVEMP and oVEMP tests, bithermal caloric test and video HIT for all semicircular canals were recorded for both groups. The results of this study showed that the highest prevalence of abnormalities in Ménière’s patients were seen in the PTA (85%), followed by cVEMP (72.5%) and oVEMP (67.5%). Caloric test abnormalities followed with a lower prevalence of 32.5%. The vHIT presented the lowest prevalence of abnormalities with 20% in the lateral canal, 7.5% in the anterior and 5% in the posterior. This pattern of abnormality agrees with the histopathological pattern of hydrops formation in the vestibular system. The findings of the current study suggest that with the advancement in the stage of MD, abnormal cVEMP, oVEMP, caloric and vHIT responses occur following the histopathological evidence of progression of the disease from the saccule up to the semicircular canals. Based on these findings, the authors suggest a new staging scheme for MD.

Management of Ménière's Disease: How Does the Coexistence of Vestibular Migraine Affect Outcomes?

OBJECTIVE

To report the incidence of vestibular migraine (VM) in patients with Ménière's disease (MD) and investigate whether management outcomes of MD differ by the association of VM.

STUDY DESIGN

Retrospective cohort study.

SETTING

Tertiary care academic center.

PATIENTS

MD patients (n = 251) with/without VM who were managed for 5 years in a dizziness clinic.

MAIN OUTCOME MEASURES

Influence of VM on management outcomes and hearing at the latest follow-up in stepwise management options.

RESULTS

Incidence of VM was 35% in MD patients. VM was more common in women than men (40 vs. 22%) and in probable MD than definite MD (43 vs. 29%). Bilateral MD was more frequent with coexistence of VM than without VM in definite MD (14 vs. 0%) as well as probable MD (24 vs. 7%). At the latest follow-up, preventive medications were effective in controlling vertigo in most (80%) patients (74%/90% in definite/probable MD). Additional intratympanic steroids were required in 16% (20%/10% in definite/probable MD) and intratympanic gentamicin or surgeries in 9 (6%) patients with intractable MD. The percentage of intractable MD did not differ with coexistence of VM, though definite MD showed a significantly higher percentage of intractable MD than probable MD (6 vs. 0%, respectively, p = 0.002). Worsening hearing was more frequent in definite MD than probable MD (19 vs. 4%), and association of VM did not influence the incidence of worsening hearing.

CONCLUSIONS

Coexistence of VM was about 30 to 40% in definite and probable MD, especially frequent in bilateral MD (77%) and women with probable MD (50%), requiring identification of coexisting VM while managing MD patients. Management outcomes and worsening hearing in MD patients are not dependent on the coexistence of VM, when both are managed.

Video-head impulse test results in patients with Menière's disease related to duration and stage of disease

BACKGROUND:

The video-head impulse test employs the vestibulo-ocular reflex (VOR) to assess vestibular function. To this day, no consensus has been reached among scientists in terms of whether or not vHIT results change in MD patients as the disease progresses.

OBJECTIVE:

To assess whether the vHIT is more often abnormal in later stages of MD compared to earlier stages.

METHODS:

We retrospectively analyzed patients with ‘definite’ MD who had undergone a vHIT and caloric test between 2012 and 2015. Patients were evaluated based on duration of disease in years (≤1, >1≤5, >5≤10, >10) and stage of disease (stage I and II versus III and IV). For the vHIT, an abnormal vestibulo-ocular reflex was defined as a gain cut-off value of≤0.8 and presence of correction saccades including subanalyses using a cut-off value of≤0.9.

RESULTS:

In 89 definite MD patients (42 (47%) male, mean age 55±5 (SD)), data on both the caloric test and the vHIT were available. The risk of an abnormal vHIT was 25% in patients with a duration of disease over 10 years compared to 22% in the patients with a disease duration of 10 years or less (risk difference 3%, 95% CI:– 28% to 35%), p = 0.82). The risk for an abnormal vHIT in the Stage I and Stage II was 17% compared to 26% in Stage III and IV (risk difference 9%, 95% CI:– 30% to 11%). When using a cut-off value of 0.9 we also did not demonstrate a relationship between the duration of disease and the proportion of abnormal vHIT test results.

CONCLUSIONS:

There is no relationship between the proportion of abnormal vHIT test results in patients with MD in either duration or stage of disease.

The Reliability and Validity of "Dokuz Eylül University Meniere's Disease Disability Scale"

OBJECTIVE

Ménière's Disease (MD) is a chronic, non-life threatening inner ear disease, with attacks of disabling vertigo, progressive hearing loss, and tinnitus as the major symptoms. All three symptoms, separately or in combination, cause great distress and have a considerable impact on the quality of life of the patients. The aims of this study were to develop a disease-specific quality of life survey for patients with MD and to analyze the relationships between the audiovestibular findings and the survey.

MATERIALS AND METHODS

Following Ear-Nose-Throat examination and audiovestibular tests, the Dokuz Eylül University Meniere's Disease Disability Scale (DEU-MDDS) and Turkish version of the Dizziness Handicap Inventory (DHI-T) were administered to 93 patients with definite MD. Reliability and validity analyses of the scale were performed.

RESULTS

There were 45 (48.4%) male and 48 (51.6%) female patients and the mean age was 48.9±12.1 years. Cronbach's alpha was 0.92 and intraclass correlation coefficients of the DEU-MMDS were significant (p<0.001). Results of the Goodness of Fit Statistics showed that the expression levels of the items were high and the correlation coefficients of each item with the scale were sufficient. There was a statistically significant correlation between DHI-T scores and MDDS. DEU-MDDS was not related to the vestibular tests, age or gender (p>0.05).

CONCLUSION

The MDDS is a valid and reliable scale as a disease-specific quality of life questionnaire for patients with MD.

Intralabyrinthine Schwannoma: Distinct Features for Differential Diagnosis

Objectives: The aim of this study was to delineate the clinical and laboratory features suggestive of intralabyrinthine schwannoma (ILS). Methods: We compared the clinical features of 16 patients with ILS, who had been diagnosed at the Seoul National University Bundang Hospital from 2003 to 2018, with those of 18 patients with symptomatic unilateral intracanalicular schwannoma and randomly selected 20 patients with definite or probable unilateral Meniere's disease (MD). Results: Patients with ILS presented with either recurrent spontaneous dizziness/vertigo combined with auditory symptoms (n = 8), isolated auditory symptoms without dizziness/vertigo (n = 7), or recurrent spontaneous dizziness/vertigo without auditory symptoms (n = 1). Most patients reported no improvement (n = 11) or worsening (n = 1) of the symptoms despite medical treatments including intratympanic (n = 5) or intravenous steroids (n = 2). Conventional brain MRIs failed to detect ILS in about a half of the patients (7/16, 44%). However, ILS showed a filling defect on 3-dimensional (3D) heavily T2-weighted MRIs (n = 12), and nodular enhancement on 3D contrast-enhanced T1 (n = 15) or FLAIR MRIs (n = 13) targeted for the inner ear. Compared to MD or intracanalicular schwannoma, ILS showed mostly abnormal head-impulse tests (HITs, p = 0.001). In contrast, the incidence of canal paresis did not differ among the groups (p = 0.513). Conclusion: ILS may mimic MD by presenting recurrent dizziness/vertigo and auditory symptoms. ILS should be suspected in patients with recurrent audiovestibulopathy especially when (1) the duration of the dizziness is not typical for MD, (2) the patients do not respond to medical treatments, or (3) HITs are abnormal.

Results in caloric test, video head impulse test and inner ear MRI in patients with Ménière's disease

OBJECTIVE

Our aim was to elucidate relationships between results from the caloric test (c-test), video Head Impulse Test (vHIT) and inner ear gadolinium-enhanced MRI (ieMRI) in patients with endolymphatic hydrops (EH), especially patients with Ménière's disease (MD).

METHODS

We managed 1789 successive patients at the Vertigo/Dizziness Center in Nara Medical University from May 2014 to December 2018. After providing informed consent for vertigo/dizziness examinations, 281 patients were hospitalized to check their inner ear function for proper diagnosis and treatment. Then 76 participants underwent the c-test, vHIT and ieMRI. Among these 76 cases, 20 were diagnosed with MD (20/76; 26.3%) and 56 were non-MD (56/76; 73.7%) according to the 2015 diagnostic guideline of the International Classification of Vestibular Disorders. The MD group included 15 unilateral and 5 bilateral cases. The non-MD group included 22 benign paroxysmal positional vertigo, 10 vestibular neuritis, 8 sudden deafness with vertigo, 6 orthostatic dysregulation, 4 vestibular neuropathy and 6 others. Results in these examinations in the side of an active lesioned inner ear were representative in each peripheral case.

RESULTS

Twenty-nine of the 76 patients (38.1%) showed discrepant results between the c-test (outside of normal range) and vHIT (within normal range). Twenty-two of 76 patients (28.9%) had a positive EH sign on ieMRI. The c-test/vHIT discrepancy percentage in MD (14/20; 70.0%) was significantly higher than that in non-MD (15/56; 26.8%) (p=0.00179). The positive EH sign in ieMRI percentage in MD (15/20; 75.0%) was significantly higher than that in non-MD (7/56; 12.5%) (p=0.0015). There was a significant positive relationship between the c-test/vHIT discrepancy and the positive EH sign (p=0.00058) in all 76 cases combined. However, there was no significant relationship between c-test/vHIT discrepancy and positive EH sign (p=0.13) in the 20 MD cases. Considering the 15 unilateral and 5 bilateral MD cases, the c-test/vHIT discrepancy was observed in 14 of the 25 affected ears. Positive signs of vestibular EH herniation into the cupula in the lateral semicircular canal was seen in 14 of the 25 MD ears. There was significant relationship between the c-test/vHIT discrepancy and EH herniation (p=0.0012) in MD ears.

CONCLUSION

The present results suggest that patients with MD could have inner ear EH significantly more often than those with non-MD. In cases with MD, a positive EH sign on ieMRI did not always indicate a c-test/vHIT discrepancy; both findings may occur due to herniation of vestibular EH adjacent to the lateral semicircular canal.

Dissociation of caloric and head impulse tests: a marker of Meniere's disease

A retrospective analysis of the horizontal video head impulse test (vHIT) results and caloric testing results was undertaken on 644 patients who attended a neuro-otology outpatient facility. Presenting symptoms included spontaneous vertigo, positional vertigo, imbalance or chronic subjective dizziness. For 570 patients, the results of vHIT and caloric testing were concordant. Both tests were normal in 500 subjects with an average vHIT gain = 0.92 ± 0.09 (L); 0.98 ± 0.10 (R) and canal paresis (CP) = 7.88 ± 6.12; (range 0-28%). 54 had concordant asymmetries, average ipsilesional vHIT gain = 0.56 ± 0.15, average contralesional vHIT gain = 0.88 ± 0.12. CP = 68.02 ± 24.38 (range 31-100%). 16 subjects had bilateral vestibular hypofunction with average vHIT gains of 0.42 ± 0.20 (L); 0.41 ± 0.19 (R), peak slow phase velocity (SPV) on warm caloric testing = 2.68 ± 2.08, range 0-6°/s (L) and 3.75 ± 3.43 range, 0-10°/s (R). 36 patients showed a dissociation of results between the two tests. In these subjects, the vHIT gain was normal (0.93 ± 0.06 left and 0.98 ± 0.07 right) and the caloric test showed a CP > 30% (48 ± 13.8%). Their final diagnoses included clinically definite Meniere's disease (MD) (n = 27), vestibular schwannoma (VS) (n = 2) vestibular migraine (VM) (n = 1), vestibular neuritis (VN) (n = 5) and unknown (n = 1). No patient with abnormal HSCC gain on vHIT had a normal caloric result. The caloric test complements the vHIT in the assessment of vestibular disorders and is most useful in suspected endolymphatic hydrops. Asymmetric caloric function in the presence of normal horizontal head impulse tests is most commonly associated with Meniere's disease and may function as a diagnostic marker.

Vertical head impulse and caloric are complementary but react opposite to Meniere's disease hydrops

OBJECTIVES/HYPOTHESIS

Meniere's disease (MD) patients can show normal head impulses despite poor caloric test results. This study aimed to investigate the discrepancy in the vestibulo-ocular reflex (VOR) in MD patients and whether endolymphatic hydrops (EH) influence the VOR.

STUDY DESIGN

Prospective, cross-sectional observational study.

METHODS

Ninety MD patients were enrolled. Neuro-otological testing, including a video head impulse test (vHIT) of all semicircular canals (SCs), and gadolinium-enhanced inner ear magnetic resonance imaging were performed. The vestibular EH volume was quantitatively evaluated by processing magnetic resonance images.

RESULTS

Abnormal vHIT results in MD patients were found most frequently in the posterior (44.4%) SCs, followed by the horizontal (13.3%) and anterior (10%) SCs. Canal paresis (CP) was assessed using the vHIT and the caloric test, and results were not significant when vHIT responses were assessed as CP only using the horizontal SC. The difference in the vestibular EH between the presence and absence of CP was not significant if assessed using the vHIT (P = .5591), but it was statistically different if assessed using the caloric test (P = .0467).

CONCLUSIONS

The contradictory reaction of VOR in MD patients may result from the high specificity but low sensitivity of CP in the horizontal vHIT. EH volume in the vestibule affects the caloric response but does not affect the vHIT response.

LEVEL OF EVIDENCE

2b Laryngoscope, 129:1660-1666, 2019.

The head impulse test as a predictor of videonystagmography caloric test lateralization according to the level of examiner experience: A prospective open-label study

We conducted a study to compare how well the head impulse test (HIT), without and with eye-movement recordings, would predict videonystagmographic (VNG) caloric test lateralization when performed by a resident and an experienced otoneurologist. This prospective, open-label, blinded study was conducted in an ambulatory tertiary care referral center. Our study population was made up of 60 patients-29 men and 31 women, aged 20 to 82 years (mean: 56.4 ± 11.4)-with peripheral vestibulopathy who underwent HIT and VNG caloric testing. The HIT was conducted in two protocols: HIT0 and HIT1. The HIT0 was performed with passive brisk movements of the patient's head from the 0° null position to 20° sideways, and the HIT1 was performed toward the center while the null position was a 20° head rotation to the right and to the left. Each protocol was carried out without video eye-movement recordings (HIT0 and HIT1) and with such recordings (rHIT0 and rHIT1). The primary outcome measures were (1) a comparison of the HIT's sensitivity and specificity when performed by the resident and by the experienced otoneurologist and (2) the ability of video-recorded HIT to predict VNG caloric test lateralization. The sensitivity and specificity obtained by the resident were 41 and 81%, respectively, for HIT0 and 41 and 90% for HIT1. The sensitivity and specificity obtained by the experienced otoneurologist were 18 and 89% for HIT0 and 32 and 85% for HIT1. Analysis of the recorded eye-movement clips of the HIT0 and HIT1 obtained by a second experienced otoneurologist found a sensitivity and specificity of 32 and 63% for rHIT0 and 33 and 82% for rHIT1. We conclude that the HIT yields high false-negative rates in predicting significant caloric lateralization. Analysis of the eye-movement recordings was no better than normal testing alone for detecting saccades. The experience of the examining physician had no impact on test performance characteristics.

Inferior turbinate reduction: Diode laser or conventional partial turbinectomy?

Hypertrophy of the inferior nasal turbinate is one of the most common causes of nasal obstruction. The diode laser has proven to be as effective as other lasers for this indication. Our objective was to study various outcomes associated with the use of the diode laser, such as improvements in nasal obstruction and postoperative pain, reduction in intraoperative bleeding, and rapidity of healing. A nonrandomized, controlled trial was conducted in which outcomes were compared between diode laser turbinate reduction (LTR) and conventional partial inferior turbinectomy (PIT) in 60 patients, 30 who underwent LTR and 30 who underwent PIT. The improvement in nasal obstruction was measured postoperatively up to 6 months. Intraoperative bleeding was measured and postoperative pain scores were assessed each day up to the fifth postoperative day. Rapidity of healing was evaluated until 6 months postoperatively. Subjective relief of nasal obstruction occurred in 90.8% of the LTR group and 65% of the PIT group at 6 months (p < 0.05). Pain scores were significantly higher until 5 days postoperatively in the PIT group compared with the LTR group (p = 0.0001). Intraoperative bleeding mean scores (ml) were 8.03 in the LTR group and 23.29 in the PIT group (p = 0.00001). Healing was faster in the LTR group at a mean of 3.03 weeks compared with 6.33 weeks in the PIT group (p = 0.00001). Outcomes with the diode laser were better and diode LTR caused less morbidity compared with the conventional technique.

Changes of video head impulse test results in lateral semicircular canal plane by different peak head velocities in patients with vestibular neuritis

BACKGROUND

The peak head velocity influences on the video head impulse test (vHIT) results, but it has been not known how much the difference is.

AIMS

To evaluate the clinical evidence for the superiority of high-velocity compared to low-velocity vHIT.

MATERIAL AND METHODS

vHIT was performed in 30 patients with vestibular neuritis using two peak head velocities (mean 80 vs. 240°/s). vHIT gains and parameters of corrective saccades (CSs) were compared. A vHIT gain of ≤0.8 or a peak CS velocity of ≥100°/s was considered pathologic.

RESULTS

The vHIT gains were significantly lower (mean 0.5 vs. 0.6), and GA was larger (35 vs. 25%) at high-velocity vHIT, compared to low-velocity vHIT. CSs were significantly more frequent (100 vs. 80%) and peak CS velocities were larger (252 vs. 112°/s) at high-velocity vHIT. The abnormal rates based on vHIT gains were higher (90% vs. 73%) and CSs occurred more frequently (100% vs. 80%) at high-velocity vHIT. The abnormal rates based on the peak CS velocity were significantly higher at high-velocity vHIT (100% vs. 57%).

CONCLUSION

High-velocity vHIT is superior to low-velocity vHIT with a difference of 17-20% based on pathologic vHIT gains and presence of CSs.

Dissociation between caloric and head impulse testing in patients with congenital abnormalities of the semicircular canals

Background

Dissociation between caloric and head impulse test results in patients with vestibular disorders has been well documented since the introduction of video head impulse testing. Prior to the introduction of video head impulse testing, vestibular diagnostic services relied mainly on caloric testing, and it is now known that the caloric testing shows more positive results than video head impulse testing. A dissipation model was proposed to explain this dissociation.

Case reports

This paper presents two cases in which caloric testing indicated an absent or significantly reduced response on the horizontal semicircular canal plane but video head impulse testing showed near-normal or normal vestibulo-ocular reflex gain on the same plane.

Conclusion

This report supports the dissipation theory and questions the functional relevance of canal paresis values calculated from caloric test results.

Diagnostic Value of Gains and Corrective Saccades in Video Head Impulse Test in Vestibular Neuritis

Objectives We investigated changes in video head impulse test (vHIT) gains and corrective saccades (CSs) at the acute and follow-up stages of vestibular neuritis to assess the diagnostic value of vHIT. Study Design Case series with chart review. Setting Tertiary medical center. Subjects and Methods Sixty-three patients with vestibular neuritis who underwent vHIT at an initial presentation and an approximately 1-month follow-up were included. vHIT gains, gain asymmetry (GA), peak velocities of CS, and interaural difference of CS (CSD) were analyzed. Results Mean vHIT gains increased significantly from the acute stage to the follow-up exam. The mean GA, peak velocities of CS, and CSD had decreased significantly at the follow-up. The incidence of CSs was also significantly decreased at the follow-up. The abnormal rate (87%) considering both gain and CS value was significantly higher than that (62%) considering vHIT gain only at the follow-up, although the abnormal rates did not differ at the acute stage (97% vs 87%). Conclusion The abnormal rates based on both vHIT gains and CS measurements are similar at the acute stage of VN but are considerably higher at the follow-up stage compared with the abnormal rates based on vHIT gains alone. It is thus advisable to check both CS and vHIT gain while performing vHIT to detect vestibular hypofunction.

Treatment of vestibular disorders with weak asymmetric base-in prisms: An hypothesis with a focus on Ménière's disease

BACKGROUND:

Regular treatments of Ménière’s disease (MD) vary largely, and no single satisfactory treatment exists. A complementary treatment popular among Dutch and Belgian patients involves eyeglasses with weak asymmetric base-in prisms, with a perceived high success rate. An explanatory mechanism is, however, lacking.

OBJECTIVE:

To speculate on a working mechanism explaining an effectiveness of weak asymmetric base-in prims in MD, based on available knowledge.

METHODS:

After describing the way these prisms are prescribed using a walking test and its effect reported on, we give an explanation of its underlying mechanism, based on the literature.

RESULTS:

The presumed effect can be explained by considering the typical star-like walking pattern in MD, induced by a drifting after-image comparable to the oculogyral illusion. Weak asymmetric base-in prisms can furthermore eliminate the conflict between a net vestibular angular velocity bias in the efferent signal controlling the VOR, and a net re-afferent ocular signal.

CONCLUSIONS:

The positive findings with these glasses reported on, the fact that the treatment itself is simple, low-cost, and socially acceptable, and the fact that an explanation is at hand, speak in favour of elaborating further on this treatment.

Current diagnostic procedures for diagnosing vertigo and dizziness

Vertigo is a multisensory syndrome that otolaryngologists are confronted with every day. With regard to the complex functions of the sense of orientation, vertigo is considered today as a disorder of the sense of direction, a disturbed spatial perception of the body. Beside the frequent classical syndromes for which vertigo is the leading symptom (e.g. positional vertigo, vestibular neuritis, Menière’s disease), vertigo may occur as main or accompanying symptom of a multitude of ENT-related diseases involving the inner ear. It also concerns for example acute and chronic viral or bacterial infections of the ear with serous or bacterial labyrinthitis, disorders due to injury (e.g. barotrauma, fracture of the oto-base, contusion of the labyrinth), chronic-inflammatory bone processes as well as inner ear affections in the perioperative course. In the last years, diagnostics of vertigo have experienced a paradigm shift due to new diagnostic possibilities. In the diagnostics of emergency cases, peripheral and central disorders of vertigo (acute vestibular syndrome) may be differentiated with simple algorithms. The introduction of modern vestibular test procedures (video head impulse test, vestibular evoked myogenic potentials) in the clinical practice led to new diagnostic options that for the first time allow a complex objective assessment of all components of the vestibular organ with relatively low effort. Combined with established methods, a frequency-specific assessment of the function of vestibular reflexes is possible. New classifications allow a clinically better differentiation of vertigo syndromes. Modern radiological procedures such as for example intratympanic gadolinium application for Menière’s disease with visualization of an endolymphatic hydrops also influence current medical standards. Recent methodical developments significantly contributed to the possibilities that nowadays vertigo can be better and more quickly clarified in particular in otolaryngology.

Morphological correlation between caloric tests and vestibular hydrops in Ménière's disease using intravenous Gd enhanced inner ear MRI

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.

Effect of common antivertiginous agents on the high velocity vestibulo-ocular reflex

OBJECTIVE

It has long been suggested that antivertiginous medications exert their symptomatic effect through inhibition of the vestibulo-ocular reflex (VOR). We tested this hypothesis by directly measuring the VOR after administration of three agents from different substance classes: an antihistamine, a benzodiazepine and a calcium channel antagonist.

METHODS

The gain and the variability of the high velocity VOR was assessed using video head impulses (vHIT) under the following conditions: baseline, after dimenhydrinate, after diazepam and after cinnarizine.

RESULTS

We found that all three medications did not change any VOR gain or variability parameter: At 60ms, the gain was 0.95 at baseline, 0.99 under dimenhydrinate, 0.99 under diazepam and 0.96 under cinnarizine. The gain variability across repetitive head impulses remained also uninfluenced.

CONCLUSIONS

The human high frequency VOR remains robust to pharmacological perturbations at common clinical doses and the assumption that symptomatic vertigo relief is achieved merely through impairment of the VOR requires re-examination.

SIGNIFICANCE

Alternative mechanisms of pharmacological action might be operant, such as the modulation of vestibulo-cortical pathways, a differential effect on the low frequency VOR and an altered sensitivity to drugs in acute unilateral vestibulopathy.

Efficacy of steroid therapy based on symptomatic and functional improvement in patients with vestibular neuritis: a prospective randomized controlled trial

The aim of this study was to examine the efficacy of methylprednisolone in vestibular neuritis (VN) by objective and subjective measures. This prospective controlled randomized study was conducted at one tertiary hospital. Twenty-nine VN patients were randomized to either the steroid (n = 15) or the control (n = 14) group. The steroid group received methylprednisolone for 2 weeks, whereas control patients did not; both groups underwent regular vestibular exercises and were prescribed a Ginkgo biloba. Vestibular function tests including caloric test, video head impulse test (vHIT), and sensory organization test (SOT) were performed, and dizziness handicap index (DHI) was determined at enrollment; all tests were repeated at 1 and 6 months after enrollment. Both groups showed statistically significant improvements in caloric weakness and vHIT gain at 1- and 6-month follow-up evaluations compared to the initial examination; however, differences were not significant. The rates of normalization of canal paresis at 1 and 6 months were 50 and 64% in the control group and 33 and 60% in the steroid group, respectively, with no differences between the two groups. The rates of vHIT normalization at 1 and 6 months after treatment were 57 and 78% in the control group and 53 and 87% in the steroid group, respectively, with no differences between the two groups. Finally, there were no significant differences in the improvement of composite scores of SOT and the DHI scores between the two groups. In this prospective RCT, methylprednisolone had no additional benefit in patients with VN who underwent vestibular exercises and received a Ginkgo biloba.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier, NCT02098330; Trial title, The Efficacy of Steroid Therapy in Vestibular Neuritis.

Intratympanal gentamicin in Meniere's disease: Effects on individual semicircular canals

OBJECTIVE

In this retrospective study the aim of the authors was to examine the effect of gentamicin on the individual semicircular canals after low dose, single injection intratympanal gentamicin therapy in Meniere's disease.

METHODS

Data of 32 patients treated between 2011 and 2015 were collected. The high frequency, high acceleration vestibuloocular reflex (VOR) gain was measured in the individual semicircular canals using video head impulse test immediately before the first intratympanal gentamicin instillation and approximately two months later.

RESULTS

In all cases 'AAO-HNS Class A' vertigo control could be attained at least for several months. In 13 cases only one instillation was necessary. In the other 19 cases the attacks returned after a few months. In 11 cases the injection had to be repeated a second time, in 4 cases 3 injections, in 2 cases 4, in 1 case 5 injections and in another 6 injections were necessary. The initial VOR gain was normal in all cases and two months after one injection it decreased in average by 40% in a highly significant manner. However, there were cases in which, although the patients became free of attacks, the gain values remained normal.

CONCLUSION

It was possible to demonstrate a significant correlation between the gain decrease of the individual canals. There was no prognostic correlation between the initial gain decrease after the first injection and the necessity of further injections. Gain values also decreased slightly but significantly in the lateral and posteriors canals on the contralateral, untreated side, possibly because of the missing disfacilitation from the treated side.

Acute Transient Vestibular Syndrome

Background and Purpose—

The aim of this study was to determine the prevalence of stroke and efficacy of bedside evaluation in diagnosing stroke in acute transient vestibular syndrome (ATVS).

Methods—

We performed a prospective, single-center, observational study that had consecutively recruited 86 patients presenting with ATVS to the emergency department of Pusan National University Yangsan Hospital from January to December 2014. All patients received a constructed evaluation, including HINTS plus (head impulse, nystagmus patterns, test of skew, and finger rubbing) and brain magnetic resonance imagings. Patients without an obvious cause further received perfusion-weighted imaging. Multivariable logistic regression was used to determine clinical parameters to identify stroke in ATVS.

Results—

The prevalence of stroke was 27% in ATVS. HINTS plus could not be applied to the majority of patients because of the resolution of the vestibular symptoms, and magnetic resonance imagings were falsely negative in 43% of confirmed strokes. Ten patients (12%) showed unilateral cerebellar hypoperfusion on perfusion-weighted imaging without an infarction on diffusion-weighted imaging, and 8 of them had a focal stenosis or hypoplasia of the corresponding vertebral artery. The higher risk of stroke in ATVS was found in association with craniocervical pain (odds ratio, 9.6; 95% confidence interval, 2.0–45.2) and focal neurological symptoms/signs (odds ratio, 15.2; 95% confidence interval, 2.5–93.8).

Conclusions—

Bedside examination and routine magnetic resonance imagings have a limitation in diagnosing strokes presenting with ATVS, and perfusion imaging may help to identify strokes in ATVS of unknown cause. Associated craniocervical pain and focal neurological symptoms/signs are the useful clues for strokes in ATVS.

Computing simulated endolymphatic flow thermodynamics during the caloric test using normal and hydropic duct models

CONCLUSION

The obtained simulations support the underlying hypothesis that the hydrostatic caloric drive is dissipated by local convective flow in a hydropic duct.

OBJECTIVE

To develop a computerized model to simulate and predict the internal fluid thermodynamic behavior within both normal and hydropic horizontal ducts.

METHODS

This study used a computational fluid dynamics software to simulate the effects of cooling and warming of two geometrical models representing normal and hydropic ducts of one semicircular horizontal canal during 120 s.

RESULTS

Temperature maps, vorticity, and velocity fields were successfully obtained to characterize the endolymphatic flow during the caloric test in the developed models. In the normal semicircular canal, a well-defined endolymphatic linear flow was obtained, this flow has an opposite direction depending only on the cooling or warming condition of the simulation. For the hydropic model a non-effective endolymphatic flow was predicted; in this model the velocity and vorticity fields show a non-linear flow, with some vortices formed inside the hydropic duct.