Video head impulse test in stroke: a review of published studies

Accurate and timely diagnosis of posterior circulation stroke in patients with acute dizziness is a challenge that can lead to misdiagnosis and significant harm. The present review sought to identify and describe published research on the clinical application of vHIT in posterior circulation stroke. vHIT, a portable device, has gained prominence in evaluating peripheral vestibular disorders and offers potential applications in diagnosing neurological disorders, particularly posterior circulation stroke. Several studies have shown that vHIT can differentiate between stroke and vestibular neuritis based on VOR gain values, with high sensitivity and specificity. The manuscript also discusses vHIT's performance in differentiating between types of posterior circulation stroke, such as PICA, AICA, and SCA strokes. While vHIT has demonstrated promise, the review emphasizes the need for further research to validate its use as a tool to rule out stroke in acute dizziness patients in the emergency department. In conclusion, the manuscript underscores the potential of vHIT as a valuable addition to the diagnostic arsenal for acute dizziness, particularly in the context of posterior circulation stroke. It calls for further research and wider adoption of vHIT in clinical settings to improve patient care and reduce unnecessary costs associated with misdiagnoses.

Insights Into Vestibulo-Ocular Reflex Artifacts: A Narrative Review of the Video Head Impulse Test (vHIT)

Video head impulse test (vHIT) artifacts are defined as spurious elements or disturbances in the recorded data that deviate from the true vestibulo-ocular reflex response. These artifacts can arise from various sources, encompassing technological limitations, patient-specific factors, or environmental influences, introducing inaccuracies in vHIT outcomes. The absence of standardized criteria for artifact identification leads to methodological heterogeneity. This narrative review aims to comprehensively examine the challenges posed by artifacts in the vHIT. By surveying existing literature, the review seeks to elucidate the multifaceted nature of artifacts arising from technological, patient-related, evaluator-related, and environmental factors.

Vestibular function in cases of posterior semicircular canal canalolithiasis and cupulolithiasis

Objective

To analyze and compare the vestibular function of posterior canal cupulolithiasis and canalolithiasis.

Methods

The results of posterior cupulolithiasis in 45 cases, posterior canalolithiasis in 122 cases and 19 healthy controls were analyzed retrospectively.

Results

The abnormal rates of vHIT in the canalolithiasis group and the cupulolithiasis group were 42.6 and 37.8%, respectively, both higher than those in the control group (both p < 0.05); there was no statistically significant difference between two BPPV groups (p = 0.573). The abnormal vHIT in 76.9% of the canalolithiasis cases and 82.4% of the cupulolithiasis cases showed normal gain with saccades, with no difference between the groups (p = 0.859). The lesion location of vHIT in the two groups did not show a correlation with the affected side of BPPV (both p > 0.05). 84.4% of canalolithiasis and 65.0% of cupulolithiasis had abnormal VEMP results, with no significant differences in abnormality rates or sides (both p > 0.05). Abnormal results of VEMPs did not show any correlation with side (p > 0.05). The results of pc-ca and pc-cu were both abnormal in 14 cases and 7 cases, and there was no correlation between the site and side of the injury (all p > 0.05).

Conclusion

The results of vHIT and VEMP in pc-cu and pc-ca were partially abnormal, but they did not show any correlation with side of BPPV. It can be considered that there are scattered vestibular peripheral organ damage in both groups.

Assessing long-term, vestibulotoxic side effects after gentamicin therapy in neonatal sepsis or infection using video head impulse test

Study background

Newborn infection and sepsis remain serious problems. Guideline-compliant therapy includes, among other therapeutics, calculated intravenous antibiosis with gentamicin. One of the known side effects of gentamicin is severe vestibulotoxicity, which can be detected using the video head impulse test (VHIT), which is a sensitive examination method for the detection of vestibular hypofunction in children and adults. Previous studies on the vestibulotoxicity of gentamicin in newborns were carried out using caloric testing, rotary testing, and electronystagmography. Nevertheless, there are currently no data available on VHIT examinations in children who have been treated with neonatal gentamicin therapy.

Methods

A single-center, prospective cross-sectional study, was conducted at a tertial referral center. VHIT was performed on 23 children aged 3-7 years who had received intravenous gentamicin therapy for at least five days as part of the treatment of newborn sepsis between 2012 and 2016. Main outcome was median gain and occurrence of refixational saccades as measured with VHIT. In addition, the children's parents received questionnaires to detect possible risk factors and vestibular and cochlear abnormalities.

Results

Out of 23 children with a mean age of four years and seven months (ranging from 3 to 7 years), 11 (47.8%) indicated abnormal results in VHIT. The VHIT results were unilaterally abnormal in six children (26.1%) and bilaterally abnormal in five others (21.7%). Additionally, five of the children with an abnormal HIT had abnormalities, as found in the questionnaire results.

Conclusion

and Relevance: Almost half of the children observed after having undergone gentamicin therapy as newborns showed abnormalities in VHIT, although they did not show any clinical signs of disbalance or vestibular hypofunction. VHIT can serve as a sensitive investigation method for the early screening of post-therapeutic vestibulotoxic side effects after gentamicin therapy in children. Additionally, VHIT can enable early intervention in these children.

Differences in semicircular canal function in the video head impulse test in patients in the chronic stage of sudden sensorineural hearing loss with vertigo and vestibular neuritis

BACKGROUND

Sudden sensorineural hearing loss with vertigo (SHLV) and vestibular neuritis (VN) can result in prolonged dizziness.

OBJECTIVES

This study aimed to compare the video head impulse test (vHIT) of patients with SHLV and VN.

METHODS

Fifteen patients with SHLV and 21 patients with VN who visited the Vertigo/Dizziness Center of our hospital between December 2016 and February 2023 were included. vHIT was performed at the time of admission, and the VOR gain and catch up saccade (CUS) in the three types of semicircular canals (SCCs) were analyzed.

RESULTS

Pathologic vHIT results were observed most frequently in the posterior SCC (73%), followed by lateral (53%) and anterior (13%) SCCs in the SHLV group. In contrast, pathologic vHIT results were observed most frequently in the lateral SCC (100%), followed by the anterior (43%) and posterior SCC (24%) SCCs in the VN group. Pathological vHIT results in the lateral and posterior SCC showed significant differences between the two groups, but for anterior SCC, no significant differences were found.

CONCLUSIONS AND SIGNIFICANCE

Comparison of the two vHIT results revealed differences in the SCC dysfunction patterns. This may be due to the different pathophysiological mechanisms of the two vestibular disorders, which may result in prolonged vertigo.

Vestibular assessment in children with sensorineural hearing loss: diagnostic accuracy and proposal for a diagnostic algorithm

Introduction

Vestibular assessment in children with sensorineural hearing loss (SNHL) is critical for early vestibular rehabilitation therapy to promote (motor) development or guide decision making towards cochlear implantation (timing of surgery and laterality). It can be challenging from a clinical viewpoint to decide which vestibular tests should be performed for a pediatric patient. The aim of this study was to evaluate the diagnostic accuracy of several clinically available vestibular tests in children with SNHL, and to provide recommendations for the implementation of vestibular testing of children in clinical practice, to screen for vestibular hypofunction (VH).

Methods

A two-center retrospective chart review was conducted. Eighty-six patients between the age of 0 and 18 years were included in this study with SNHL. Vestibular tests included video headimpulse test (VHIT), caloric test (performed at the age of four or higher), rotatory chair and cervical vestibular evoked myogenic potential (cVEMP). A combination of the clinical assessment and (combinations of) vestibular test outcomes determined the diagnosis. The diagnostic quality of tests and combination of tests was assessed by diagnostic accuracy, sensitivity and specificity.

Results

VH was diagnosed in 44% of the patients. The VHIT and caloric test showed the highest diagnostic accuracy compared to the rotatory chair and cVEMP. All combinations of VHIT, caloric test and cVEMP showed improvement of the diagnostic accuracy compared to the respective tests when performed singularly. All combinations of tests showed a relatively similar diagnostic accuracy, with the VHIT combined with the caloric test scoring the highest. Adding a third test did not substantially improve the diagnostic accuracy.

Discussion

Vestibular testing is feasible and VH is highly prevalent in children with SNHL. A proposed diagnostic algorithm recommends starting with VHIT, followed by cVEMP for children under the age of four, and caloric testing for older children if VH is not confirmed with the first test. Performing a third test is redundant as the diagnostic accuracy does not improve substantially. However, challenges remain, including the lack of a gold standard and the subjective nature of the diagnosis, highlighting the need for standardized testing and increased understanding of VH in this population.

Cochleovestibular Phenotype in a Rare Genetic MED13L Mutation

The gene MED13 participates in transcription. The MED13L gene is a paralog of MED13 that is involved in developmental gene expression. Mutations in the gene have been shown to result in a heterogenous phenotype affecting several physiological systems. Hearing loss has been reported very rarely, and vestibular weakness has never been reported in the condition. In this report, we present a mutation of MED13L in c.1162A > T (p.Arg388Ter), where we detail and describe a cochleovestibular phenotype with objective vestibulometry for the first time. The child showed bilateral sloping sensorineural hearing loss, a bilateral vestibular weakness, and an inner ear vestibular structural abnormality on imaging. Early intervention with hearing aids and vestibular rehabilitation led to a favorable outcome in terms of speech, communication, and balance. We emphasize the importance of comprehensive audiovestibular assessment in children diagnosed with MED13L mutations for effective management of these children.

Objective Neurological Testing Methods Used to Follow Up Vestibular Neuritis Depending on Different Factors

Purpose

We analyze the impact of different factors on clinical performance and prognosis in vestibular neuritis (VN) and explore indicators that could accurately reflect changes in patients' symptoms at different stages.

Methods

We observed patients with VN during the acute and recovery phases. Clinical symptoms, vertigo-related scales, neurological examination, vestibular function tests (caloric test, video head impulse test (vHIT), vestibular evoked myogenic potential (VEMP)), and the history of disease (underlying diseases, glucocorticoid therapy) were recorded at onset and at 4 and 12 weeks after onset in VN patients. Multiple linear regression analysis was used to identify vestibular function tests that had a linear regression relationship with the subjective quantitative results.

Results

At 4 weeks after onset, the group without underlying disease had better improvement in EEV, gain, and UW than the group with underlying disease (P < 0.05). There was a significant difference in the change in DHI, EEV, gain of the affected horizontal semicircular canal in the vHIT and unilateral weakness (UW) between the glucocorticoid treatment group and the no glucocorticoid treatment group (P < 0.05), and glucocorticoid treatment group was better. The change value in the gain of horizontal canals in the vHIT was mainly positively and linearly correlated with the EEV scores (P<0.001). Possible dynamic correlation between vHIT results and vestibular symptoms.

Conclusion

The absence of underlying disease and the receipt of glucocorticoid therapy significantly contributed to the improvement of objective vestibular function tests in the short term, while the improvement of subjective vertigo may correlate with the different objective measures and questionnaire. We believe that the improvement of the affected horizontal semicircular canal gain value in the vHIT can be used as a reference indicator of the degree of improvement of vestibular symptoms with superior vestibular neuritis.

Impaired Vestibulo-Ocular Reflex on Video Head Impulse Test in Superior Canal Dehiscence: "Spontaneous Plugging" or Endolymphatic Flow Dissipation?

Surgical plugging of the superior semicircular canal (SSC) represents an effective procedure to treat disabling symptoms in superior canal dehiscence (SCD), despite resulting in an impaired vestibulo-ocular reflex (VOR) gain for the SSC. On the other hand, SSC hypofunction on video head impulse test (vHIT) represents a common finding in patients with SCD exhibiting sound/pressure-induced vertigo, a low-frequency air-bone gap (ABG), and enhanced vestibular-evoked myogenic potentials (VEMPs). "Spontaneous canal plugging" has been assumed as the underlying process. Nevertheless, missing/mitigated symptoms and/or near-normal instrumental findings would be expected. An endolymphatic flow dissipation has been recently proposed as an alternative pathomechanism for SSC VOR gain reduction in SCD. We aimed to shed light on this debate by comparing instrumental findings from 46 ears of 44 patients with SCD exhibiting SSC hypofunction with post-operative data from 10 ears of 10 patients with SCD who underwent surgical plugging. While no difference in SSC VOR gain values was found between the two groups (p = 0.199), operated ears developed a posterior canal hypofunction (p = 0.002). Moreover, both ABG values (p = 0.012) and cervical/ocular VEMP amplitudes (p < 0.001) were significantly higher and VEMP thresholds were significantly lower (p < 0.001) in ears with SCD compared to operated ears. According to our data, canal VOR gain reduction in SCD should be considered as an additional sign of a third window mechanism, likely due to an endolymphatic flow dissipation.

Influence of Age and Cardiovascular Risk Factors in Vestibular Neuritis: Retrospective Cohort Study

To analyze the influence of age and cardiovascular risk factors (CVRFs) in the evolution of vestibular neuritis (VN).

METHODS

Retrospective cohort study. VN-diagnosed patients were included and divided into two groups: those with and without CVRFs. We analyzed the mean vestibular-ocular reflex (VOR) gain, measured through the video head impulse test (vHIT) at the diagnosis and one-year follow-up. We conducted a factorial analysis of variance (ANOVA) to evaluate the effect of age, sex, and CVRFs in the mean VOR gain.

RESULTS

Sixty-three VN-diagnosed patients were included. There were no statistically significant differences in the mean VOR gain between both groups. However, in the subgroup analysis, there were statistically significant differences when comparing the mean VOR gain at the one-year follow-up between the group over 55 years of age 0.77 ± 0.20 and the group under 55 years 0.87 ± 0.15 (p = 0.036). Additionally, the factorial ANOVA demonstrated a significant main effect of age group on the mean VOR gain at the one-year follow-up (p = 0.018), and it also found a significant interaction between the factors of gender, age group, HTN (p = 0.043).

CONCLUSIONS

CVRFs do not independently affect the mean VOR gain in VN patients' follow-ups. However, age significantly impacts VOR gain in VN and could be modulated by gender and hypertension.

Long-term dance training modifies eye-head coordination in response to passive head impulse

Long-term dance training is known to improve postural control, especially in challenging postural tasks. However, the effect of dance training on the vestibulo-ocular reflex (VOR) has yet to be properly assessed. This study directly investigated whether VOR parameters are influenced by long-term dance training by testing dancers and controls using the video head impulse test. VOR gains using two of the most common methods (area ratio and instantaneous gains), latency and amplitude of the first saccade, if applicable, were computed. Results revealed a larger VOR gain as measured by area gain and instantaneous gain at 40 ms specifically for left-head impulses, but not right-head impulses. No significant differences in saccade frequency, amplitude, or latency were observed between groups. These differences appear to stem from a modified eye-to-head relationship during high-velocity head impulses in dancers. More specifically, the dancers' eyes lead head movement during passively applied head impulses, which result in higher VOR gain.NEW & NOTEWORTHY This study demonstrates, for the first time, that long-term dance training results in a nonlinear relationship between eye and head velocity within the first milliseconds following passive head impulse. The data also suggest a larger VOR gain in dancers. This finding suggests that dance training may modify eye-head relationship in passive high-frequency head movements. This is of particular interest for vestibular rehabilitation.

Variability in the Results of Vestibular Assessment in Patients with Genetically Confirmed Cerebellar Ataxia, Neuropathy, and Vestibular Areflexia Syndrome

BACKGROUND

Cerebellar ataxia, neuropathy, and vestibular areflexia syndrome (CANVAS) presents an unpredictable and uneven clinical development of cerebellar ataxia, neuropathy, and vestibular areflexia. The aim of this study is to report the variability of vestibular test results in genetically confirmed patients with cerebellar ataxia, neuropathy, and vestibular areflexia syndrome.

METHODS

Caloric testing, video head impulse test (vHIT), and rotatory chair testing were performed in 7 patients who presented pathogenic repeat expansions in the replication factor complex unit 1 gene related to cerebellar ataxia, neuropathy, and vestibular areflexia syndrome.

RESULTS

Reduced vestibulo-ocular reflex (VOR) gain was observed in 100% of the patients in rotatory chair testing. Three of them had bilateral areflexia in caloric testing while 2 showed unilateral hypofunction and 2 had no alterations in the test. Only 1 patient had bilateral abnormal vHIT with gains under 0.6 in both ears.

CONCLUSION

Genetic testing allows an early diagnosis of cerebellar ataxia, neuropathy, and vestibular areflexia syndrome, whereby the vestibular system may be affected to different degrees. Rotatory chair testing has a higher sensitivity for the detection of vestibular hypofunction in these patients. Caloric testing can provide additional information. vHIT might underdiagnose patients with mild-to-moderate vestibulopathy.

Ethanol-Induced Vestibular Dysfunction as a Model for Bilateral Vestibular Syndrome: Similarities in Video Head Impulse Test and Video-Oculography Data

BACKGROUND

The goal of this study was to compare video head impulse test, video-oculography, and clinical balance test changes induced by ethanol consumption, in order to acquire a model for acute bilateral vestibular syndrome.

METHODS

Four healthy adult men and 5 healthy adult women were recruited as volunteers in the study. Initial video head impulse test, videooculography, and clinical balance test examinations were made. Participants proceeded to drink standard alcohol doses until a maximum of 1.2‰ breath alcohol concentration was reached. Video head impulse test and clinical balance tests were repeated at every 0.2‰ breath alcohol concentration interval and at the final 1.0-1.2‰ breath alcohol concentration range. Video-oculography examinations were repeated at 1.0- 1.2‰ breath alcohol concentration.

RESULTS

Decrease in mean vestibulo-ocular gain at 60 ms between the 0‰ and 1.0-1.2‰ was 0.16 on the left side (P < .05) and 0.16 on the right side (P < .05). A borderline abnormality (mean 0.79/0.82) (left/right) was observed in vestibulo-ocular gain at the highest breath alcohol concentration. Corrective saccades increased significantly in amplitude and latency. There was a statistically significant, symmetrical decrease in video-oculography smooth pursuit gain. Saccade latency increased but statistically significantly only with right-sided cycles. Saccade accuracy remained constant. Optokinetic reflex gain showed significant decrease. Romberg's test was performed with normal results initially and at 1.0-1- 2‰ breath alcohol concentration.

CONCLUSION

Ethanol produces a symmetrical loss in vestibulo-ocular gain measured by video head impulse test. Ethanol also decreases smooth eye pursuit gain and increases pro-saccade latency. Similar findings can be made in vestibular disorders as well as in cerebellar dysfunction. Central pathology should be ruled out in acute bilateral vestibular syndrome.

Vestibular function in children with vestibulocochlear nerve aplasia/hypoplasia

BACKGROUND

Infants and young children with vestibulocochlear nerve (VCN) hypoplasia/aplasia present with severe hearing loss and are candidates for cochlear implantation (CI). It is unknown whether vestibular function is related to CI outcome and if vestibular tests can guide the operation decision.

AIMS/OBJECTIVES

Our aim was to describe the vestibular function in patients with VCN hypoplasia/aplasia before a possible CI.

MATERIALS AND METHODS

Forty-two ears in 23 patients were tested between 2019 and 2022 with bone-conducted cervical vestibular evoked myogenic potentials (BCcVEMP), video head impulse test (vHIT) and miniice-water caloric test (mIWC).

RESULTS

All ears could be tested with at least one vestibular test and 83% could be tested with more than one method. Twenty-nine ears (61%) showed normal function with at least one method. The presence of a normal response to any test doubled the likelihood of a measured hearing threshold after CI, the best predictors being the BCcVEMP and vHIT (p < 0.05).

CONCLUSION

Canal function may represent a predictor of auditive pathway integrity with a possible favourable audiological outcome after CI operation.

SIGNIFICANCE

Our results demonstrate high vestibular response rates suggesting a functioning pathway despite the radiological diagnosis.

Prospective analysis of video head impulse tests in patients with acute posterior circulation stroke

Background

Video head impulse tests (vHITs), assessing the vestibulo-ocular reflex (VOR), may be helpful in the differential diagnosis of acute dizziness. We aimed to investigate vHITs in patients with acute posterior circulation stroke (PCS) to examine whether these findings could exhibit significant abnormalities based on lesion locations, and to evaluate diagnostic value of vHIT in differentiating dizziness between PCS and vestibular neuritis (VN).

Methods

We prospectively recruited consecutive 80 patients with acute PCS and analyzed vHIT findings according to the presence of dorsal brainstem stroke (DBS). We also compared vHIT findings between PCS patients with dizziness and a previously studied VN group (n = 29). Receiver operating characteristic (ROC) analysis was performed to assess the performance of VOR gain and its asymmetry in distinguishing dizziness between PCS and VN.

Results

Patients with PCS underwent vHIT within a median of 2 days from stroke onset. Mean horizontal VOR gain was 0.97, and there was no significant difference between PCS patients with DBS (n = 15) and without (n = 65). None exhibited pathologic overt corrective saccades. When comparing the PCS group with dizziness (n = 40) to the VN group (n = 29), patients with VN demonstrated significantly lower mean VOR gains in the ipsilesional horizontal canals (1.00 vs. 0.57, p < 0.001). VOR gain and their asymmetry effectively differentiated dizziness in the PCS from VN groups, with an area under the ROC curve of 0.86 (95% CI 0.74-0.98) and 0.91 (95% CI 0.83-0.99, p < 0.001), respectively.

Conclusion

Significantly abnormal vHIT results were rare in patients with acute PCS, even in the presence of DBS. Moreover, vHIT effectively differentiated dizziness between PCS and VN, highlighting its potential for aiding differential diagnosis of acute dizziness.

Evaluation of vestibular functions in patients with obstructive sleep apnea syndrome

BACKGROUND

To determine the anatomical proximity of the vestibular nuclei to the respiratory nuclei and the effect of susceptibility of the posterior labyrinth to a hypoxic state on the vestibular system.

OBJECTIVE

It was aimed to evaluate the possible effects of periodic hypoxia on vestibular reflexes and proprioceptive perception in patients with obstructive sleep apnea syndrome (OSAS).

MATERIAL AND METHODS

The study was conducted with 40 patients diagnosed with moderate and severe OSAS and 21 healthy individuals. All individuals were evaluated with Dizziness Handicap Inventory, ocular vestibular evoked myogenic potential (oVEMP), cervical vestibular evoked myogenic potential (cVEMP), video head impulse test (vHIT), videonystagmography (VNG) and sportKAT 3000.

RESULTS

In the vHIT, a statistically significant difference was found between the groups in terms of anterior and posterior semicircular canal vestibulo-ocular reflex gains (p < .05). A negative correlation was found between the lateral gain asymmetry and RALP gain asymmetry and the awake blood oxygen level in the OSAS groups. There was a statistically significant difference between the groups in terms of wave response rates cVEMP 100 dB nHL and oVEMP 100-110 dB nHL (p < .05).

CONCLUSION AND SIGNIFICANCE

It was concluded that vestibular reflexes and proprioceptive perception were affected due to periodic/chronic hypoxia in patients with moderate and severe OSAS.

Impact of Endolymphatic Hydrops and Semicircular Canal Dysfunction on the Incomplete Recovery of Acute Low-Frequency Sensorineural Hearing Loss

OBJECTIVE

The reasons for short-term, incomplete recovery of some acute low-frequency sensorineural hearing loss (ALFHL) are unclear. We investigated the impact of endolymphatic hydrops and semicircular canal dysfunction on the incomplete recovery of ALFHL.

METHODS

The impact of electrocochleography (EcochG), caloric test, video head impulse test (vHIT), cervical vestibular-evoked myogenic potential (cVEMP), and ocular vestibular-evoked myogenic potential (oVEMP) results on the incomplete recovery of 86 patients with ALFHL was analyzed. The correlation between a high abnormal rate of vestibular-evoked myogenic potential (VEMP) and aural fullness, dizziness, and level of hearing loss was also examined.

RESULTS

Abnormal oVEMP with an odds ratio (OR) of 6.071 (P = .002) and EcochG with an OR of 5.919 (P = .005) were independent risk factors for incomplete recovery in ALFHL, but abnormal cVEMP, caloric test, and vHIT were not independent risk factors for ALFHL. There was no correlation between a high abnormal rate of VEMP and aural fullness, dizziness, or level of hearing loss in ALFHL.

CONCLUSION

Abnormal oVEMP and EcochG values rather than caloric test and vHIT were risk factors for incomplete recovery of ALFHL, which may be related to the difficulty of successfully treating utricular and cochlear hydrops. High abnormal rate of VEMP was not correlated with hearing loss level, aural fullness, or dizziness in ALFHL. Abnormal oVEMP and EcochG values can indicate poor short-term prognosis of ALFHL.

Barotrauma-Induced Perilymph Fistula: Video Head Impulse Test and High-Resolution Temporal Bones Computed Tomography Role in Evaluation and FollowUp

We report a case of a woman presenting with unilateral right profound hearing loss accompanied by vertigo secondary to barotrauma-induced perilymph fistula during recreational skydiving. Video head impulse test demonstrated a reduced gain in both the right horizontal and right anterior semicircular canals accompanied by frequently gathered overt corrective saccades. High-resolution computed tomography revealed an enlarged vestibular aqueduct on the affected side, a predisposing factor for the development of perilymph fistula. An exploratory tympanotomy was performed during which a perilymph leak was visualized at the round window niche. Temporal fascia patches enforced by absorbable gelatin sponges were applied to both round and oval windows. During post-surgery follow-up, the patient remained free of vestibular symptoms. An audiogram displayed mild improvement in the right ear speech reception threshold, although her hearing remained non-serviceable. The video head impulse test showed a favorable dynamic with a stepwise return to normal gain values in all semicircular canals and the disappearance of overt corrective saccades. This is the first case in which video head impulse test was employed as a valuable diagnostic tool for the evaluation and post-surgery follow-up of vestibular function in a barotrauma-induced perilymph fistula. The demonstration of an enlarged vestibular aqueduct on high-resolution computed tomography and the risk of perilymph fistula recurrence are discussed.

Vestibular test results in patients with vestibular migraine and Meniere's Disease

BACKGROUND

Vestibular migraine (VM) and Meniere's Disease (MD) are episodic vestibular disorders, sometimes difficult to differentiate from each other on clinical grounds.

OBJECTIVE

To evaluate vestibular test results of the two groups that may help in the differential diagnosis.

METHODS

Twenty-two patients with VM, 21 patients with definite MD and 21 healthy volunteers (HC) were studied. Pure tone hearing thresholds (PTHT), cervical vestibular evoked myogenic potentials (cVEMPs), video head impulse test (vHIT) and functional head impulse test (fHIT) were performed.

RESULTS

PTHT of the MD-affected ears were significantly higher than VM and HC groups (p < .001 for both) when cVEMP amplitudes were lower (p = .005 for HC), (p = .006 for VM). Lateral canal vHIT gain of the MD-affected ears were lower than VM patients (p = .003) and the HC (p < .001). The percentage of correctly identified optotypes (CA%) on fHIT was low for both patient groups when compared with the HC (p < .001).

CONCLUSION

In addition to hearing loss, low cVEMP amplitudes on the affected side with decreased gain on vHIT indicate disturbed saccular and lateral semicircular canal functions in MD patients differentiating them from VM. A functional deficit in gaze stabilization detected by fHIT is the only abnormality found in patients with VM.

Does vestibular function correlate with objective MRI findings after vestibular schwannoma surgery?

Objective

Vestibular schwannoma surgery leads to acute unilateral vestibular loss. In some patients, however, the process of post-operatively initiated central compensation proceeds more rapidly than in others. This study aimed to evaluate post-operative vestibular function and correlate it with morphological findings of MRI scans.

Methods

The study included 29 patients who underwent surgery for vestibular schwannoma. Vestibular function was analysed post-operatively by video head impulse test (vHIT). Subjective symptoms were evaluated using validated questionnaires. All patients underwent MRI 3 months post-operatively, and the presence of the facial and vestibulocochlear nerves in the internal auditory canal was assessed.

Results

The vestibulo-ocular reflex gain measured by the vHIT correlated positively with audiological findings. Subjective perception of vestibular disorder did not correlate with objectively measured vestibular impairment or with MRI findings.

Conclusions

After the resection of vestibular schwannoma, some patients may still have preserved vestibular function as measured by vHIT. The preserved function does not correlate with subjective symptoms. Patients with partially deteriorated vestibular function showed lower sensitivity to combined stimuli.

Quantitative vestibular assessment: The development and validation of a novel, remote video head impulse test against in-clinic measurements

Objectives

To develop a novel remote head impulse test (rHIT), and to provide preliminary data validating the rHIT vestibular-ocular reflex (VOR) gains against the in-clinic vHIT.

Methods

A convenience sample of 10 patients referred for vestibular assessment at our institution was recruited. In-clinic vHIT was used to quantify lateral VOR gains. Patients subsequently underwent an rHIT protocol, whereby patients performed active, lateral head rotations while their eyes and heads were recorded using a laptop camera and video-conferencing software. The vHIT and rHIT VOR gains were compared using paired t-tests, and a Pearson correlation coefficient between the gains was calculated. Absolute accuracy, sensitivity, and specificity of the rHIT were additionally calculated.

Results

Of the 10 patients recruited, 4 were male, and the average ± standard deviation (SD) age was 61.4 ± 15.3 years. As determined by the vHIT, 2 patients had normal bilateral VOR gains, 6 with unilateral vestibular hypofunction, and 2 with bilateral vestibular hypofunction. The correlation between the rHIT and vHIT gains was 0.73 (p < .001). The rHIT exhibited an absolute accuracy of 75.0%, sensitivity of 70.0%, and specificity of 80.0%. When ears had a vHIT VOR gain less than 0.40, the rHIT exhibited 100.0% accuracy. Conversely, 60.0% of deficient ears with vHIT VOR gains greater than 0.40 were incorrectly categorized by the rHIT.

Conclusion

The rHIT may be better suited for detecting more severe vestibular deficiencies. Future iterations of the rHIT should aim to increase the video frame-rate capabilities to detect subtler VOR impairments.

Level of Evidence

4.

Vestibular Findings on the Video Head Impulse Test (vHIT) in Pregnancy: A Cross-Sectional Study

Background Functional and anatomic changes occur during pregnancy. Some of these changes are in the auditory and vestibular systems. However, there is a lack of information about the functional changes to critical structures that contribute to balance and proprioception. This study aims to evaluate the functions and shifts to the semicircular canals throughout gestation. Methodology This is a cross-sectional study. A video head impulse test (vHIT) was performed on all healthy pregnant patients with gestational periods ranging from the 20th to 40th weeks who were admitted to a maternal-fetal care unit. Vestibulo-ocular reflex (VOR) gains in the lateral, posterior, and anterior semicircular canals and gains in asymmetry were obtained. Results A significant positive relationship was observed in the right (R = 0.1064; P = 0.0110) and left (R = 0.2993; P = 0.0001) lateral semicircular canals as gestational weeks increased. Lower gains were seen at the start of the second trimester for the lateral canals. No significant gains were seen in the anterior or posterior canals throughout pregnancies until labor. No significant gains in asymmetry were detected. Conclusions Pregnant females may present vestibular changes in the semicircular lateral canals starting from the 20th week of gestation until labor. Increased gains may be associated with volumetric changes probably given by hormonal actions.

Spontaneous Nystagmus in Patients With Posterior Semicircular Canal Benign Paroxysmal Positional Vertigo

OBJECTIVE

This study aimed to investigate the incidence of spontaneous nystagmus (SN) in posterior semicircular canal (PSCC) benign paroxysmal positional vertigo (BPPV) and its effect on treatment outcomes.

STUDY DESIGN

Retrospective case series.

SETTING

Tertiary referral center.

METHODS

This study included 50 patients with idiopathic unilateral PSCC BPPV between July 2021 and May 2022. The presence of SN was investigated, and the results of the bithermal caloric test and video head impulse test (vHIT) were compared.

RESULTS

SN was observed in 13 (26%) of the 50 patients presenting PSCC BPPV. The direction of SN was mainly unidirectional and horizontal in 12 of the 13 patients with a slow-phase velocity ranging from 2 to 4°/s. One patient presented an upbeating torsional SN at the initial evaluation. The mean vHIT gain of the PSCC on the affected side was significantly lower in patients with SN than those without SN (p = .004, Mann-Whitney U test). The proportion of patients who recovered within 2 sessions of the repositioning maneuver was significantly higher in those without SN than that in those with SN (p < .001, Fisher's exact test).

CONCLUSION

This study demonstrated that the treatment outcomes of PSCC BPPV were significantly worse in patients with SN than those without SN. Examining the presence of SN in patients with PSCC BPPV may be helpful in counseling the patients on prognosis, and it is expected that more sessions of canalith repositioning maneuver may be required to treat PSCC BPPV in patients with SN than those without SN.

[Application of vestibular function examination in the analysis of damaged site in patients with acute vestibular neuritis]

Objective:To analyze the site of vestibular nerve damaged in patients with acute vestibular neuritis. Methods:Fifty-seven patients with acute vestibular neuritis were recruited, and each patient underwent caloric irrigation test, video head impulse test（vHIT） and vestibular evoked myogenic potentials（VEMPs）. The results were further analyzed. Results:Analysis of abnormal rates of different vestibular function tests: the abnormal rate of caloric irrigation test, horizontal semicircular canal vHIT, anterior semicircular canal vHIT, and posterior semicircular canal vHIT were 92.98%, 92.98%, 92.98%, and 52.63%, respectively. The abnormal rate of cervical vestibular evoked myogenic potentials（cVEMP） and ocular vestibular evoked myogenic potentials（oVEMP） were 52.63% and 89.47%. The abnormal rate of caloric irrigation test, horizontal semicircular canal vHIT, anterior semicircular canal vHIT, and oVEMP were significantly higher than posterior semicircular canal vHIT and cVEMP（P<0.01）. Combination analysis of different vestibular function tests: there are twenty-six patients（45.61%, superior and inferior vestibular nerve） with abnormal caloric irrigation test, video head impulse test, and VEMPs. There are twenty-five patients（43.86%, superior vestibular nerve） with abnormal caloric irrigation test, horizontal semicircular canal vHIT, anterior semicircular canal vHIT, and oVEMP. There are 4 patients（7.02%, inferior vestibular nerve） with abnormal posterior semicircular canal vHIT and cVEMP. There are two patients（3.51%, ampullary vestibular nerve） with abnormal caloric irrigation test, horizontal semicircular canal vHIT, and anterior semicircular canal vHIT. The rate of superior and inferior vestibular neuritis and superior vestibular neuritis were significantly higher than inferior vestibular neuritis and ampullary vestibular neuritis（P<0.01）. Conclusion:Acute vestibular neuritis subtypes can be divided into four categories: superior and inferior vestibular neuritis, superior vestibular neuritis, inferior vestibular neuritis, and ampullary vestibular neuritis. Video head impulse test can accurately assess the site of vestibular nerve damage in patients with acute vestibular neuritis. In addition, vHIT combined with VEMPs can provide objective evidence for the diagnosis of ampullary vestibular neuritis.

Prevalence of bilateral vestibulopathy among older adults above 65 years on the indication of vestibular impairment and the association with Dynamic Gait Index and Dizziness Handicap Inventory

PURPOSE

To estimate the prevalence of bilateral vestibulopathy (BV) and evaluate the association with, and concurrent validity of the Dynamic Gait Index (DGI) and the Dizziness Handicap Inventory (DHI) in diagnosing BV based on video head impulse test (vHIT) among older adults ≥65 years referred to a geriatric falls clinic on suspicion of vestibular impairment.

MATERIALS AND METHODS

The vHIT was applied as a reference standard of BV to estimate diagnostic parameters for optimal cut-off scores of DGI and DHI applied separately and in combination.

RESULTS

Two-hundred medical records were reviewed (70% women, mean age 79.4 years). The prevalence of BV was 9%. DGI was weakly associated with BV: Odds Ratio (OR) 1.15 (95% confidence interval (CI): 1.01; 1.31), with a 93% sensitivity and 47% specificity of a cut-off score of 16. The total score of DHI showed no association with BV: OR 1.01 (95% CI: 0.98; 1.04). The concurrent validity for BV and DGI and/or DHI were found to be inadequate.

CONCLUSIONS

A prevalence of 9% underlines the relevance for assessment of BV. Only a weak association between DGI and/or DHI and BV was found. Thus, vHIT remains the preferred test for detecting BV in geriatric fall assessments.IMPLICATIONS FOR REHABILITATIONBilateral vestibulopathy (BV) has numerous negative consequences for older adults and the prevalence is high among older adults referred to a geriatric falls clinic on suspicion of vestibular impairment.The Dynamic Gait Index (DGI) and the Dizziness Handicap Inventory (DHI) are not valid alternatives to the Video Head Impulse Test (vHIT) when assessing BV among geriatric outpatients.

Preceding Balance Disorders Affect Vestibular Function in Persistent Postural-Perceptual Dizziness

Persistent postural-perceptual dizziness (PPPD) is induced by preceding conditions that cause balance disorders. To investigate the association between vestibular function and preceding balance disorders in PPPD patients, a retrospective chart review was performed. Vestibular function in 55 PPPD patients was measured using the caloric test, cervical vestibular evoked myogenic potential testing to air-conducted sound (ACS cVEMP), ocular vestibular evoked myogenic potential testing to bone-conducted vibration (BCV oVEMP), and video head impulse testing (vHIT). Patients were classified according to the type of preceding balance disorder. The age-stratified Cochran-Mantel-Haenszel (CMH) test and the exact test for the common odds ratio were conducted to evaluate the association between preceding n ≥ 4 balance disorders and present peripheral vestibular dysfunction. PPPD patients with preceding vestibular neuritis presented a significant positive association with abnormal caloric responses (p = 0.013), while those with preceding benign paroxysmal positional vertigo (BPPV) had significantly lower rates of abnormal BCV oVEMP (p = 0.003). Furthermore, patients with preceding vestibular neuritis showed lateral semicircular canal dysfunction, while those with preceding BPPV presented normal utricular functions. These results present the influence of preceding balance disorders on the vestibular function in PPPD.

Determining the effect of obstructive sleep apnea syndrome on peripheral vestibular system and hearing

There have been studies in the literature regarding the effect of obstructive sleep apnea syndrome on hearing function, but studies on the effect of obstructive sleep apnea syndrome on the peripheral vestibular system are limited. The aim of the present study was to determine whether obstructive sleep apnea syndrome causes functional neurological changes, particularly in the peripheral vestibular system, using the video head impulse test. Overall, 57 patients with obstructive sleep apnea syndrome were included; the 'Snorers' group comprised 20 volunteers diagnosed with simple snoring in the polysomnography test. The severity of apnea was assessed by monitoring cardiac and respiratory functions during sleep in both groups. The video head impulse test and audiological evaluations were performed in both groups. Statistically significant differences were found in the cochlea and semicircular canals of our patients in the video head impulse test and audiological battery tests. It may be assumed that decreased blood oxygen concentrations and chronic hypoxaemia have negative effects on the vestibule, cochlear sensory epithelium, and the auditory pathways. We think that inner ear structures and pathways may be affected due to hypoxia in obstructive sleep apnea syndrome. Therefore, screening patients with obstructive sleep apnea syndrome with an audiometry battery may help to detect inner ear pathologies early.

Functional and Molecular Markers for Hearing Loss and Vertigo Attacks in Meniere's Disease

Meniere's disease (MD) is one of the most complicated diseases in the otologic clinic. The complexity of MD is partially due to the multifactorial etiological mechanisms and the heterogenous symptoms, including episodic vertigo, hearing loss, aural fullness and tinnitus. As a result, the diagnosis of MD and differentiating MD from other diseases with similar symptoms, such as vestibular migraine (VM), is challenging. In addition, it is difficult to predict the progression of hearing loss and the frequency of vertigo attacks. Detailed studies have revealed that functional markers, such as pure tone audiometry (PTA), electrocochleography (ECochG), vestibular evoked myogenic potential (VEMP), caloric test, video head impulse test (vHIT) and magnetic resonance imaging (MRI) could help to evaluate MD with different hearing levels and frequency of vertigo attacks. Investigations of molecular markers such as autoimmunity, inflammation, protein signatures, vasopressin and circadian clock genes in MD are still underway. This review will summarize these functional and molecular markers, address how these markers are associated with hearing loss and vertigo attacks in MD, and analyze the results of the markers between MD and VM.

Discrepancies of video head impulse test results in patients with idiopathic sudden sensorineural hearing loss with vertigo and vestibular neuritis

Objective

Sudden sensorineural hearing loss with vertigo (SHLV) and vestibular neuritis (VN) remain frequent causes of acute vestibular syndrome (AVS). The aim of study was to compare the results of video head impulse test (vHIT) in patients with SHLV and VN. The characteristics of high-frequency vestibule-ocular reflex (VOR) and the differences of the pathophysiological mechanisms underlying these two AVS were explored.

Methods

Fifty-seven SHLV patients and 31 VN patients were enrolled. vHIT was conducted at the initial presentation. The VOR gains and occurrence of corrective saccades (CSs) of anterior, horizontal, and posterior semicircular canals (SCCs) in two groups were analyzed. Pathological vHIT results refer to impaired VOR gains and presence of CSs.

Results

In SHLV group, pathological vHIT results was most prevalent in the posterior SCC on the affected side (30/57, 52.63%), followed by horizontal (12/57, 21.05%) and anterior SCC (3/57, 5.26%). In VN group, pathological vHIT preferentially affected horizontal SCC (24/31, 77.42%), followed by anterior (10/31, 32.26%) and posterior SCC (9/31, 29.03%) on the affected side. As for anterior and horizontal SCC on the affected side, the incidences of pathological vHIT results in VN group were significantly higher than those in SHLV group (β = 2.905, p < 0.01; β = 2.183, p < 0.001). There were no significant differences in the incidence of pathological vHIT result in posterior SCC between two groups.

Conclusion

Comparison of vHIT results in patients with SHLV and VN revealed discrepancies in the pattern of SCCs impairments, which may be explained by different pathophysiological mechanisms underlying these two vestibular disorders presenting as AVS.

Presence of corrective saccades in patients with normal vestibulo-ocular reflex gain in video head impulse test

Background

The video head impulse test (vHIT) is a valuable clinical tool that can help identify dysfunction of the semicircular canals. While in cases with semicircular canal dysfunction, both decreased vestibulo-ocular reflex (VOR) gain and corrective saccades (CS) are usually observed, there are cases which show CS despite normal VOR gain in vHIT.

Objective

This study aimed to investigate the clinical characteristics of patients who showed CS with normal VOR gain in vHIT.

Materials and methods

Among 390 patients who underwent vHIT, 51 patients (20 males and 31 females, age 31-87 years, average 61.3 years old) who showed CS with normal VOR gain unilaterally during horizontal vHIT were included. All patients had normal vHIT (normal VOR gain and absent CS) on the contralateral side.The VOR gain of vHIT, the maximum slow phase velocity in the caloric test, and the amplitude of cervical and ocular vestibular evoked myogenic potentials (cVEMPs and oVEMPs) were analyzed.

Results

The VOR gain on the affected side (0.95 ± 0.08) was significantly smaller than that on the contralateral side (1.03 ± 0.13) in horizontal vHIT (p < 0.001). The maximum slow phase velocity in the caloric test on the affected side (17.9 ± 17.8 degrees/s) was significantly smaller than that on the contralateral side (21.3 ± 16.6 degrees/s, p = 0.020). There were no significant differences in the amplitude of cVEMPs or oVEMPs between the affected side and the contralateral side (p = 0.096 for cVEMP; p = 0.770 for oVEMP).

Conclusion

The side that showed CS with normal VOR gain in horizontal vHIT showed significantly smaller VOR gain as well as smaller caloric responses compared to the contralateral side. Having CS with normal VOR gain could be a sensitive indicator of mild dysfunction of the semicircular canals.

vHIT results with the synapsis system according to clinicians' dominant hand use

BACKGROUND/OBJECTIVE

There exists limited information in the literature on dominant hand preference in relation with vHIT applications. The present study aimed to examine the relationship between the clinician's dominant use of right- or left-hand and vHIT results.

METHODS

A Synapsys vHIT Ulmer device was used in the study. The tests were administered by 3 clinicians experienced in vHIT, 2 of whom were right-handed and 1 left-handed. The test was applied to the 94 participants three times, one week apart.

RESULTS

In this study, the correlation between right-handed clinicians and left-handed clinicians was examined, and in all SCCs, namely RA, LA, RL, LL, RP and LP, a moderate positive significant correlation was found between right-handed1 and right-handed2, between right-handed1 and left-handed, and between right-handed2 and left-handed.

CONCLUSIONS

In this study, these findings suggested that measures were reliable across test sessions regardless of hand dominancy (right or left). Based on the vHIT results we obtained with three different right- or left-handed clinicians, the clinician should evaluate the results according to the dominant side.

Greater Disability Is Associated with Worse Vestibular and Compensatory Oculomotor Functions in People Living with Multiple Sclerosis

Globally, there are nearly three million people living with multiple sclerosis (PLW-MS). Many PLW-MS experience vertigo and have signs of vestibular dysfunction, e.g., low vestibulo-ocular reflex (VOR) gains or the presence of compensatory saccades (CSs), on video head impulse testing (vHIT). We examined whether the vestibular function and compensatory oculomotor behaviors in PLW-MS differed based on the level of MS-related disability. The VOR gain, CS frequency and latency, and gaze position error (GPE) were calculated from the individual traces obtained during six-canal vHIT for 37 PLW-MS (mean age 53.4 ± 12.4 years-old, 28 females) with vertigo and/or an imbalance. The subjects were grouped by their Expanded Disability Status Scale (EDSS) scores: PLW-min-MS (EDSS = 1.0-2.5, n = 8), PLW-mild-MS (EDSS = 3.0-4.5, n = 23), and PLW-moderate-MS (EDSS = 5.0-6.0, n = 6). The between-group differences were assessed with Kruskal-Wallis tests. The VOR gains for most of the canals were higher for PLW-min-MS compared to PLW-mild- and mod-MS, respectively. CS occurred less often in PLW-min-MS versus PLW-mild- and mod-MS, respectively. No clear trend in CS latency was found. The GPE was often lower for PLW-min-MS compared to PLW-mild- and mod-MS, respectively. Thus, our data demonstrate that worse VOR and compensatory oculomotor functions are associated with a greater MS-related disability. PLW-MS may benefit from personalized vestibular physical therapy.

[Correlation between video head impulse test parameters and DHI score in patients with vestibular neuritis]

Objective:To explore the correlation between the parameters of video head impulse test （vHIT）and dizziness handicap inventory （DHI） score in patients with vestibular neuritis. Methods:Clinical data of 46 patients with vestibular neuritis were retrospectively analyzed. All the patients underwent DHI evaluation and vHIT examination. They were divided into mild handicap group, moderate handicap group and severe handicap group according to DHI score. The correlations between the parameters of vHIT and DHI score were compared among the three groups. The important parameters of vHIT were compared including vestibulo-ocular reflex （VOR） gain, gain asymmetry ratio （GA）, abnormal saccade dispersion （PR%）. Results:Of the 46 patients, 10 were in the mild handicap group, 21 in the moderate handicap group, and 15 in the severe handicap group. ①In the comparison of the mean value of lateral semicircular canal VOR gain, the vHIT gain of patients with mild, moderate and severe handicap were 0.64±0.06, 0.53±0.11 and 0.37±0.10, respectively, the mean value of VOR gain was negatively correlated with DHI score among the three groups（r=-0.545, P<0.001）, and the pairwise comparisons among the three groups was statistically significant（P<0.05）. In comparison of the mean values of lateral semicircular canal GA, the GA values of mild, moderate and severe handicap groups were 46.40±21.81, 47.59±15.17 and 56.57±17.39, respectively, there was no significant linear correlation between GA values and DHI scores among the three groups（r=0.246, P>0.05）, there was no significant difference between the three groups（P>0.05）. In comparison of the mean PR% of the lateral semicircular canal, the mean PR% of patients with mild, moderate and severe handicap group were 32.00±10.62, 53.82±17.09 and 76.00±10.01, respectively, PR% was positively correlated with DHI score（r=0.726, P<0.001）, and the comparison among the three groups was statistically significant（P<0.05）. ②The vertical semicircular canal vHIT gain of patients with mild, moderate and severe handicap was 0.63±0.06, 0.52±0.15 and 0.38±0.16, respectively, the mean of VOR gain was negatively correlated with DHI score among the three groups（r=-0.487, P<0.01）, the comparison of mild-severe and moderate-severe group was statistically significant（P<0.05）, while there was no significant difference between the mild and moderate group（P>0.05）. In the comparison of the mean values of vertical semicircular canal GA, the GA values of mild, moderate and severe handicap groups were 40.40±15.31, 46.10±19.59 and 47.87±18.05, respectively, there was no significant linear correlation between GA values and DHI scores among the three groups（r=0.047, P>0.05）, there was no significant difference in GA among the three groups（P>0.05）. The PR% of patients with mild, moderate and severe handicap were 42.40±15.39, 54.14±17.60 and 64.93±10.95, respectively, there was a positive significant correlation between PR% and DHI score（r=0.454, P<0.05）, there was statistically significant in the comparison of mild-severe group（P<0.05）, while there was no statistical significance between the other groups（P>0.05）. Conclusion:The VOR gain and PR% value of vHIT in patients with vestibular neuritis are closely related to the DHI score, which can evaluate the vestibular function and the degree of vertigo.

[The occurrence and evaluation methods of horizontal semicircular canal dysfunction in patients with common vestibular diseases]

Objective:To understand the occurrence of horizontal semicircular canal functional impairment in patients with common vestibular diseases and to explore the characteristics and clinical value of different evaluation methods of horizontal semicircular canal. Methods:From July 2013 to December 2016, patients who attended the vertigo clinic of the First Affiliated Hospital of Dalian Medical University and completed more than three horizontal semicircular canal function tests were retrospectively analyzed. A total of 396 patients diagnosed as vestibular migraine （VM）, Ménière's disease （MD）, benign paroxysmal positional vertigo （BPPV）, vestibular neuritis （VN） and 104 patients with unknown diagnosis were enrolled. The results of caloric test （CT）, rotation test （RT）, head-shaking nystagmus test （HSN） and video head impulse test （vHIT） were collected and the abnormal detection rates of different detection methods were calculated. The sensitivity, specificity and coincidence rate of various detection methods were statistically analyzed using CT as the gold standard. Results:①The abnormal rates of the four evaluation methods from high to low were HSN, CT, RT, vHIT （51.20%, 50.80%, 25.76%, 19.74%, respectively）; ②Taking CT as the gold standard, among these four common vestibular diseases, the sensitivity and specificity of vHIT were 0.13-0.41 and 0.69-1.00, the sensitivity and specificity of HSN were 0.44-0.76 and 0.29-0.69, and the sensitivity and specificity of RT were 0.25-0.45 and 0.50-0.84;③According to statistical analysis, only HSN and CT results showed no statistically significant difference in the 4 diseases. There was no significant difference between RT and CT in VM and BPPV, and vHIT and CT in BPPV. Conclusion:The abnormal rate of HSN results in common vestibular diseases is highest, and it could be recommended as a routine vestibular function screening item. The specificity of vHIT is highest and worthy of promotion. CT is still an irreplaceable method to evaluate the function of horizontal semicircular canal.

[The application value of video head impulse test, caloric test and dizziness handicap inventory in the diagnosis of acoustic neuroma]

Objective:To explore the application value of video head impulse test（vHIT）, caloric test（CT） and the dizziness handicap inventory（DHI） in the diagnosis of acoustic neuroma（AN）, to analyze the correlation between vHIT and CT, and to determine the correlationsof tumor size, vHIT, CT and DHI score. Methods:The clinical data of 24 patients with AN who underwent surgery in our department from January 2019 to January 2022 were analyzed retrospectively, including craniocerebral MRI, vHIT, caloric test and DHI score. All the data were statistically analyzed by GraphPadPrism9.0. Results:There was a significant negative correlation between the UW value of CT and the vestibular eye reflex gain of vHIT（P<0.01, r=-0.62）. The tumor size was significantly correlated with the increase of UW value of CT（P<0.01, r=0.69）, and with the decrease of vestibulo-ocular reflex gain of vHIT（P<0.01, r=-0.53）. The average Dizziness Handicap Inventory score was 8.9±16.2, which was not correlated with tumor size（P>0.05）. Conclusion:Both vHIT and CT can effectively evaluate the vestibular function of patients with AN（and they are complementary）, and they are related to the size of the tumor and have certain value in the diagnosis of acoustic neuroma.

Clinical characteristics of patients with dizziness/vertigo showing a dissociation between caloric and video head impulse test results

OBJECTIVE

To explore the clinical characteristics of patients with dizziness/vertigo who showed a dissociation between the results of the caloric test and video head impulse test (vHIT).

METHODS

A total of 327 patients who complained of dizziness/vertigo were continuously included. All patients underwent both the horizontal vHIT (h-vHIT) and caloric tests. Of the 327 patients, 69 patients showed a dissociation between the results of the two tests, 4 patients were excluded because the interval between the two tests exceeded 7 days. Finally, 65 patients were included in the analysis.

RESULTS

Among the 65 patients, 55 (84.6%) patients showed a positive caloric test (+) with a negative h-vHIT (-), and 10 (15.4%) patients showed a negative caloric test (-) with a positive h-vHIT (+). Peripheral and central lesions were identified in 50 (90.9%) and 5 (9.1%) patients, respectively, in the caloric test (+)/h-vHIT (-) group; and central lesions were found in 6 (60%) patients in caloric test (-)/h-vHIT (+) group. The etiologies were unilateral peripheral vestibular dysfunction (n = 25), Meniere's disease (MD, n = 10), sudden hearing loss with vertigo (SHLV, n = 7), benign paroxysmal positional vertigo (n = 5), vestibular neuritis (n = 2), autoimmune inner ear disease (n = 1), vestibular migraine (VM, n = 3), multiple sclerosis (n = 1), and multiple system atrophy (n = 1) in the caloric test (+)/h-vHIT (-) group, which were SHLV (n = 3), MD (n = 1), VM (n = 1), episodic ataxia type 2 (n = 1), cerebellopontine angle tumor (N = 1), Parkinson's disease (n = 1), Persistent postural perceptual dizziness (n = 1), and posterior circulation ischemia (n = 1) in the caloric test (-)/h-vHIT (+) group.

CONCLUSION

Dissociation between the results of caloric test and h-vHIT is not uncommon. A positive caloric test with a negative h-vHIT occurred more frequently, and these patients mostly had peripheral vestibular lesions; while a negative caloric test with a positive h-vHIT was unusual, these patients had both peripheral and central lesions.

Video Head Impulse Test (vHIT): Value of Gain and Refixation Saccades in Unilateral Vestibular Neuritis

The aim of this study was to evaluate gain and refixation saccades (covert and overt) using a video head impulse test (vHIT) in the horizontal and vertical planes in patients after the onset of unilateral acute vestibular neuritis (AVN). Thirty-five patients were examined in the acute stage of AVN and at follow-up (range, 6–30 months); a control group of 32 healthy subjects also participated. At onset, the mean gain was significantly lower on the affected side in all of the semi-circular canal planes, mainly in the horizontal canal plane, and saccades (covert and overt) were more prevalent in the horizontal compared to the vertical canal planes. Multi-canal affection occurred more frequently (80% for gain, 71% for saccades) than isolated canal affection. At follow-up, which ranged from 6 to 30 months, the gain was recovered in all of the canals (anterior in 50%, horizontal in 42.8%, and posterior canal in 41.1% of cases), while covert and overt saccades were reduced in the horizontal and vertical planes. However, covert saccades were still recorded in a greater proportion (69%) than overt saccades (57%) in the horizontal plane and at a lower rate in the vertical planes. The compensatory mechanisms after AVN mainly involve the horizontal canal, as the refixation saccades—especially covert ones—were more frequently recorded in the horizontal than vertical canals.

Head impulse testing in bilateral vestibulopathy in patients with genetically defined CANVAS

BACKGROUND

To investigate the association between disease duration and the severity of bilateral vestibulopathy in individuals with complete or incomplete CANVAS (Cerebellar Ataxia with Neuropathy and Vestibular Areflexia Syndrome) and biallelic RFC1 repeat expansions.

METHODS

Retrospective analysis of clinical data and the vestibulo-ocular reflex quantified by the video head impulse test in 20 patients with confirmed biallelic RFC1 repeat expansions.

RESULTS

Vestibulo-ocular reflex gain at first admittance 6.9 ± 5.0 years after disease onset was 0.16 [0.15-0.31] (median [interquartile range]). Cross-sectional analysis revealed that gain reduction was associated with disease duration. Follow-up measurements were available for ten individuals: eight of them exhibited a progressive decrease of the vestibulo-ocular reflex gain over time. At the first visit, six of all patients (30%) did not show clinical signs of cerebellar ataxia.

CONCLUSIONS

Our data suggest a pathological horizontal head impulse test, which can easily be obtained in many outpatient clinics, as a sign of bilateral vestibulopathy in genetically confirmed CANVAS that can precede clinically accessible cerebellar ataxia at least in a subset of patients. The presumably continuous decline over time possibly reflects the neurodegenerative character of the disease. Thus, genetic testing for RFC1 mutations in (isolated) bilateral vestibulopathy might allow disease detection before the onset of cerebellar signs. Further studies including a wider spectrum of vestibular function tests are warranted in a prospective design.

Using Functional Outcomes to Predict Vestibular Loss in Children

OBJECTIVE

The purpose of this study was to determine: (1) the relationship between vestibular loss severity and functional performance, (2) which functional performance outcomes best predict vestibular loss, and (3) which vestibular rate sensors (canals vs. otoliths) provide the most weighting during different functional measures.

STUDY DESIGN

Prospective.

SETTING

Tertiary referral center.

PATIENTS

Fifty-seven children with normal hearing (mean age: 12.3 years, 32 males) and 55 children with cochlear implants (mean age 12.8 years, 29 males).

INTERVENTION

Diagnostic.

MAIN OUTCOME MEASURES

Video head impulse test, cervical vestibular evoked myogenic potential (cVEMP), ocular VEMP (oVEMP), single leg stance, Standing Balance Test, active and passive dynamic visual acuity, and the balance subtest of the Bruininks-Oseretsky Test of Motor Proficiency (BOT-2).

RESULTS

Performance worsened as vestibular loss severity worsened for all functional outcomes except the standing balance test conditions 1 and 2. The best outcomes for classifying children with vestibular loss were the single leg stance (cut-off criterion: 5 seconds; sensitivity and specificity of 88% and 86%) and the BOT-2 balance subtest (cut-off criterion of 27.5 points; sensitivity and specificity of 88% and 88%). Average horizontal canal vHIT gain was a significant predictor of all functional outcomes while neither corrected cVEMP amplitude nor oVEMP amplitude predicted performance.

CONCLUSION

Functional performance declines as vestibular loss severity worsens. Single leg stance is fast and efficient for predicting vestibular loss in school age children. Average horizontal canal vHIT best predicts functional performance; if using a tiered approach, horizontal canal vHIT should be completed first.

Assessment of the Clinical Use of Vestibular Evoked Myogenic Potentials and the Video Head Impulse Test in the Diagnosis of Early-Stage Parkinson's Disease

OBJECTIVES

To explore the usefulness of vestibular tests including "vestibular evoked myogenic potentials" (VEMPs) and the video head impulse test (vHIT) in the early diagnosis of "idiopathic Parkinson's disease" (PD).

MATERIALS AND METHODS

The study involved 80 participants including 40 patients (24 males, 16 females; age average 63.20 ± 7.94 years) with PD and 40 healthy individuals (18 males and 22 females; age average of 60.36 ± 7.68 years). The Modified Hoehn and Yahr (H&Y) scale was used to measure how Parkinson's symptoms progress and the level of disability. Patients with PD underwent cVEMPs, oVEMPs, and vHIT and the results were compared with those of 40 age-matched healthy control (HC) subjects. vHIT results and VEMP responses were registered in all patients and HCs.

RESULTS

One-sided absent cVEMP responses were found in 6 (15%) patients with PD and 8 (20%) patients had bilaterally absent responses. Five (12.5%) patients had 1-sided absent oVEMP responses and it was bilateral in 6 (15%). Patients with PD had significantly shorter cVEMP P1, N1 latency, lower cVEMP amplitudes, and oVEMP amplitudes than the HC group. The cVEMP and oVEMP amplitude asymmetry ratio was significantly higher in the PD group (P < .05). Evaluation of vHIT results and vestibular-ocular reflex (VOR) gain between the groups revealed that anterior canal and posterior canal VOR gains results were remarkably lower in the PD group than in the HCs (P < .05). There was no difference in right and left lateral canal VOR gains between the groups (P > .05).

CONCLUSION

The results of this study suggest that cVEMP and vHIT can be used to evaluate the vestibular system in patients with early-stage Parkinson's disease.

Cervical vestibular evoked myogenic potentials and video head impulse test studies: alternative methods for detecting brainstem involvement in multiple sclerosis

BACKGROUND

Brainstem involvement (BSI) has been reported as a major predictive factor for future disability in Multiple Sclerosis (MS).

AIMS/OBJECTIVES

To evaluate whether Cervical Vestibular Evoked Myogenic Potentials (cVEMPs) and Video Head Impulse Test (vHIT) can be used to detect demyelinating lesions in vestibular pathways in MS.

MATERIAL AND METHODS

Fifty three people with MS and 40 controls were evaluated with Dizziness Handicap Inventory (DHI), vHIT and cVEMP.

RESULTS

The median value of DHI in MS group was significantly higher than controls (p<.001). According to vHIT results, while the results of horizontal canal vestibulo-ocular reflex gain in group with brain stem involvement (gBSI (+)) were significantly different from both controls and group without brain stem involvement (gBSI (-)) (p= .036 and .024, respectively), results of gBSI (-) were similar with controls (p= .858). When cVEMP results were examined, mean P1 wave latency in gBSI (+) was significantly longer than controls (p= .002), but difference between gBSI (-) and controls and gBSI (+) was not statistically significant (p= .104 and .279, respectively).

CONCLUSIONS AND SIGNIFICANCE

vHIT and cVEMP can be used in diagnosis and follow-up of people with MS without demyelinating brainstem lesions on MRI.

Evaluation of the effects of Covid-19 on cochleovestibular system with audiovestibular tests

PURPOSE

The purpose of the present study was to investigate the effects of COVID-19 on audiovestibular system with Transiently Evoked Distortion Otoacoustic Emissions (TOAE), Distortion Product Otoacoustic Emissions (DPOAE), video head impulse test (vHIT) and caloric test.

METHODS

Audiovestibular findings of 24 patients with moderate/severe COVID-19 and 24 healthy controls were compared using pure tone audiometry, tympanometry, TOAE, DPOAE, caloric test, and vHIT.

RESULTS

On audiometry, the pure tone averages of the COVID-19 patients were higher than the controls (P = .038). The TEOAE amplitudes at 4000 and 5000 Hz (P = .006 and P < .01), and DPOAE amplitudes at 3000, 6000, and 8000 Hz (P < .001, P = .003 and P < .001) were significantly lower in COVID-19 patients compared to the controls. On vestibular tests, there was no significant difference between the caloric test results of the patients and the controls (P > .05). On vHIT testing, amplitudes of right semicircular canal was found to be significantly lower in COVID-19 group compared to the control group (P = .008).

CONCLUSION

COVID-19 may affect inner ear functions causing a subtle damage in the outer hair cells and lateral semicircular canals. It must be kept in mind that COVID-19 may cause cochleovestibular problems.

Effect of cochlear implantation on vestibular function in children: A scoping review

OBJECTIVE

To provide a scoping review of the available literature for determining objectively the effect of cochlear implantation on vestibular function in children.

METHODS

A literature search was performed and the following criteria were applied: vestibular tests that were performed on subjects within the range of 0-18 years old before and after cochlear implantation. The papers conducted at least one of the following tests: (video) head impulse test, caloric test, cervical and ocular vestibular evoked myogenic potentials or rotatory chair test. Included papers underwent quality assessment and this was graded by risk of bias and directness of evidence.

RESULTS

Fourteen articles met the selection criteria. The included studies showed that cochlear implantation leads to a decrease in vestibular function in a proportion of the patient population. This loss of vestibular function can be permanent, but (partial) restoration over the course of months to years is possible. The pooling of data determined that the articles varied on multiple factors, such as time of testing pre- and post-operatively, age of implantation, etiologies of hearing loss, used surgical techniques, type of implants and the applied protocols to determine altered responses within vestibular tests. The overall quality of the included literature was deemed as high risk of bias and medium to low level of directness of evidence. Therefore, the data was considered not feasible for systematic analysis.

CONCLUSION

This review implicates that vestibular function is either unaffected or shows short-term or permanent deterioration after cochlear implantation in children. However, the heterogeneity of the available literature indicates the importance of standardized testing to improve our knowledge of the effect of cochlear implantation on the vestibular function and subsequent developmental consequences for the concerned children.

[Dissociation of the results of caloric and video head impulse tests as a marker of Meniere's disease]

The study of vestibular function in patients with Meniere's disease (MD) is an urgent task, since it influences the choice of treatment tactic. We evaluated the results of caloric and video head impulse (vHIT) tests in 76 patients who met the clinical criteria for significant Meniere's disease (AAO-HNS modified by the Barany Society, 2015). Dissociation of the results of caloric and vHIT tests is observed in the majority (74%) of patients with MD: at normal gain, according to vHIT data, hypofunction of peripheral vestibular structures is recorded according to the caloric test (KASL 47 ± 7.8%). In patients with MD, vestibular dysfunction is observed mainly at low frequencies (0.003 Hz), therefore vHIT, which allows assessing horizontal semicircular canal function at high frequencies (3-5 Hz), is not an optimal study for assessing the degree of vestibular dysfunction in patients with MD.

Clinical Implication of Caloric and Video Head Impulse Tests for Patients With Enlarged Vestibular Aqueduct Presenting With Vertigo

Background: By examining the clinical features and results of video head impulse test (vHIT) and caloric tests in patients with enlarged vestibular aqueduct (EVA) presenting with vertigo, we aimed to investigate the function of angular vestibulo-ocular reflex (VOR) and its clinical implications.

Methods: Nine patients with EVA manifesting with vertigo were enrolled. The medical history, audiological examination, imaging, and the results of the caloric test and the vHIT were analyzed.

Results: Of the nine patients with EVA (eight bilateral and one unilateral case), five were pediatric cases. All 17 ears exhibited sensorineural hearing loss (SNHL). Enlarged vestibular aqueduct patients can present with recurrent (seven cases) or single (two cases) vertigo attack, trauma-induced (two cases), or spontaneous (seven cases) vertigo. Diminished caloric responses were observed in 77.8% (7/9) of the patients (four cases unilaterally and three bilaterally), while unilateral abnormal vHIT results in 11.1% (1/9) patients. Abnormal caloric and normal horizontal vHIT responses were found in 66.7% (6/9) of EVA patients.

Conclusions: Vestibular manifestations in EVA are diverse. Enlarged vestibular aqueduct patients with vertigo can present with a reduced caloric response and normal horizontal vHIT, and this pattern of angular VOR impairment was also found in other hydropic ear diseases.

Short-Latency Covert Saccades - The Explanation for Good Dynamic Visual Performance After Unilateral Vestibular Loss?

Background: Functional head impulse test (fHIT) tests the ability of the vestibulo-ocular reflex (VOR) to allow visual perception during head movements. Our previous study showed that active head movements to the side with a vestibular lesion generated a dynamic visual performance that were as good as during movements to the intact side. Objective: To examine the differences in eye position during the head impulse test when performed with active and passive head movements, in order to better understand the role of the different saccade properties in improving visual performance. Method: We recruited 8 subjects with complete unilateral vestibular loss (4 men and 4 women, mean age 47 years) and tested them with video Head Impulse Test (vHIT) and Functional Head Impulse Test (fHIT) during passive and active movements while looking at a target. We assessed the mean absolute position error of the eye during different time frames of the head movement, the peak latency and the peak velocity of the first saccade, as well as the visual performance during the head movement. Results: Active head impulses to the lesioned side generated dynamic visual performances that were as good as when testing the intact side. Active head impulses resulted in smaller position errors during the visual perception task (p = 0.006) compared to passive head-impulses and the position error during the visual perception time frame correlated with shorter latencies of the first saccade (p < 0.001). Conclusion: Actively generated head impulses toward the side with a complete vestibular loss resulted in a position error within or close to the margin necessary to obtain visual perception for a brief period of time in patients with chronic unilateral vestibular loss. This seems to be attributed to the appearance of short-latency covert saccades, which position the eyes in a more favorable position during head movements.

[Correlation and difference analysis in parameters between video head impulse test and caloric test in vestibular disease]

Objective:To investigate interrelationships in parameters between caloric test and video head impulse test（vHIT） in the common peripheral vertigo diseases and healthy people, and to conduct correlation and difference analysis between the results in two tests, so as to evaluate the clinical diagnosis value of peripheral vertigo. Methods:The caloric test and vHIT were fulfilled in 68 patients with vertigo and 17 healthy volunteers. The diagnosis was done according to history inquiring, otology and audiology examination and vestibular tests. The vestibulo-ocular reflex（VOR） gain and gain asymmetry（GA） of a vHIT as well as unilateral weakness（UW） and the sum of the slow-phase velocities（SPVs） of warm and cold irrigation of the same side were compared. A cutoff value of VOR gain of a vHIT was also calculated using a receiver-operating characteristic curve. Results:In all ears（n=170）, there was significant correlation in ipsilateral SPVs and VOR gain（r=0.568, P<0.0001）; In all ears（n=34） of 17 healthy volunteers, there was no correlation in ipsilateral SPVs and VOR gain（r=-0.05, P=0.778）; In all affected ears（n=76）, there was statistically positive correlation in ipsilateral SPVs and VOR gain（r=0.571, P<0.0001）; In all the unaffected ears（n=94）, there was positive correlation in ipsilateral SPVs and VOR gain（r=0.286, P=0.005）. In 60 patients with unilateral vestibular disease（n=60）, there was statistically significant negative correlation between the VOR gain of affected ears and UW（r=-0.513, P<0.0001）; there was statistically significant positive correlation between GA of a vHIT and UW（r=0.713, P<0.0001）. There was a statistically significant negative correlation between the VOR gain of affected ears and UW in the fluctuating vertigo group（r=-0.516, P=0.002） as well as a positive correlation between GA and UW（r=0.529, P=0.001）; In the non-fluctuating vertigo group, there was a statistically significant negative correlation between the VOR gain of affected ears and UW（r=-0.428, P=0.029）; there was a positive correlation between GA of a vHIT and UW（r=0.743, P<0.0001）. In the vestibular neuropathy group, there was a negative correlation between the VOR gain of affected ears and UW（r=-0.462, P=0.030）; there was a statistically significant positive correlation between GA of a vHIT and UW（r=0.757, P<0.0001）. There was a negative correlation between the VOR gain of affected ears and UW in the vestibular peripheral disease group（r=-0.516, P=0.002） as well as a statistically significant positive correlation between GA and UW（r=0.529, P=0.001）. The mean value of UW（65.5%） was higher in the overt saccade group than that in the normal VOR group, there was statistically significant difference（P=0.006）. According to the UW damage degree grading, there was statistically significant difference in abnormal educe rates（χ²=17.76, P<0.05）. Based on the gold standard of caloric response, a cutoff value of 0.865 was determined; the parameters of the two tests were dissociated in 28.3%. Conclusion:There was a statistically significant correlation in parameters between vHIT and caloric test. The patients of overt saccade always accompany with the high UW, which could indicate that the vestibular function severely damaged. vHIT and caloric test can be complementary tools for the comprehensive evaluation of patients' vestibule function, on account of dissociation between the results of vHIT and caloric test and general result of consistent check.

Long-Term Vestibular Outcomes in Cochlear Implant Recipients

Background: Vestibular dysfunction is likely the most common complication to cochlear implantation (CI) and may, in rare cases, result in persistent severe vertigo. Literature on long-term vestibular outcomes is scarce. Objective: This paper aims to evaluate vestibular dysfunction before and after cochlear implantation, the long-term vestibular outcomes, and follows up on previous findings of 35 consecutive adult cochlear implantations evaluated by a battery of vestibular tests. Methods: A prospective observational longitudinal cohort study was conducted on 35 CI recipients implanted between 2018 and 2019; last follow-up was conducted in 2021. At the CI work-up (T0) and two postoperative follow-ups (T1 and T2), 4 and 14 months following implantation, respectively, all patients had their vestibular function evaluated. Evaluation with a vestibular test battery, involving video head impulse test (vHIT), cervical vestibular evoked myogenic potentials (cVEMP), caloric irrigation test, and dizziness handicap inventory (DHI), were performed at all evaluations. Results: vHIT testing showed that 3 of 35 ears had abnormal vHIT gain preoperatively, which increased insignificantly to 4 of 35 at the last follow-up (p = 0.651). The mean gain in implanted ears decreased insignificantly from 0.93 to 0.89 (p = 0.164) from T0 to T2. Preoperatively, 3 CI ears had correction saccades, which increased to 11 at T2 (p = 0.017). Mean unilateral weakness increased from 19 to 40% from T0 to T2 (p < 0.005), and the total number of patients with either hypofunctioning or areflexic semicircular canals increased significantly from 7 to 17 (p < 0.005). Twenty-nine percent of CI ears showed cVEMP responses at T0, which decreased to 14% (p = 0.148) at T2. DHI total mean scores increased slightly from 10.9 to 12.8 from T0 to T1 and remained at 13.0 at T2 (p = 0.368). DHI scores worsened in 6 of 27 patients and improved in 4 of 27 subjects from T0 to T2. Conclusion: This study reports significant deterioration in vestibular function 14 months after cochlear implantation, in a wide range of vestibular tests. vHIT, caloric irrigation, and cVEMP all measured an overall worsening of vestibular function at short-term postoperative follow-up. No significant deterioration or improvement was measured at the last postoperative follow-up; thus, vestibular outcomes reached a plateau. Despite vestibular dysfunction, most of the patients report less or unchanged vestibular symptoms.