Video Head Impulse Test Results in Patients With a Vestibular Schwannoma-Sensitivity and Correlation With Other Vestibular System Function Tests, Hearing Acuity, and Tumor Size

Association of audiovestibular findings with fluid-attenuated inversion recovery magnetic resonance imaging in patients with vestibular schwannoma

BACKGROUND

Vestibular schwannoma (VS) is a benign tumor of the vestibular nerve. Flair-attenuated inversion recovery (FLAIR) of magnetic resonance imaging (MRI) images are sensitive in detecting high protein contents of fluids.

OBJECTIVES

To investigate the association between signal intensity (SI) on FLAIR images and audiovestibular findings in patients with VS.

METHODS

Medical records of twenty-five patients with VS were retrospectively analyzed.

RESULTS

Larger tumors were associated with increased FLAIR SI of the cochlea, vestibule, and semicircular canal (SCC) on the affected side compared to those of the unaffected side. Pure-tone audiometry (PTA), and speech audiometry were associated with the SI of the affected cochlea. There was no significant correlation between the SI of the vestibule and vestibular evoked myogenic potential, SI of the SCC, and caloric test or video head impulse test results.

CONCLUSION

Our study suggests that tumor size was significantly associated with high SI on FLAIR imaging, and audiological findings were associated with the SI of the affected cochlea. Further studies with larger cohorts are required to confirm the association between vestibular function and FLAIR imaging in VS.

The comparison between intratympanic gentamicin prehabilitation and postoperative virtual reality exposure to standard vestibular training in patients with vestibular schwannoma

OBJECTIVE

Resection of the vestibular schwannoma causes acute peripheral vestibular loss. The process of central compensation starts immediately afterward. The rehabilitation goal is to support this process and restore the quality of life.

MATERIALS AND METHODS

In this prospective single-center study, 67 consecutive patients underwent vestibular schwannoma resection (40 females, mean age 52 ± 12 years). The patients were divided into three groups: the prehabilitation with intratympanic gentamicin group, the virtual reality group (optokinetic stimulation via virtual reality goggles in the first ten days after the surgery), and the control group. All patients were examined with objective methods and completed questionnaires before the prehabilitation, before the surgery, at the hospital discharge, and after three months.

RESULTS

Intratympanic gentamicin prehabilitation leads ipsilaterally to a significant aVOR reduction in all semicircular canals (p < 0.050), the increase of the unilateral weakness in air calorics (p = 0.026), and loss of cVEMPs responses (p = 0.017). Prehabilitation and postoperative exposure to virtual reality scenes improved the patient's perception of vertigo problems according to Dizziness Handicap Inventory (p = 0.039 and p = 0.076, respectively). These findings conform with the optokinetic testing results, which showed higher slow phase velocities at higher speeds (40 deg/s) in both targeted groups compared to the control group.

CONCLUSION

Preoperative intratympanic gentamicin positively affects peripheral vestibular function, influencing balance perception after VS resection. In long-term follow-up, prehabilitation and postoperative exposure to virtual reality improve patients' quality of life in the field of vertigo problems.

The Role of Asymmetry Values, Gain, and Pathological Saccades of the Video Head Impulse Test (vHIT) in Sudden Sensorineural Hearing Loss

OBJECTIVE

The purpose of this study was to evaluate the value of asymmetry values, gain, and pathological saccades of the video head impulse test (vHIT) in sudden sensorineural hearing loss (SSNHL).

STUDY DESIGN

Retrospective study.

SETTING

Tertiary referral center.

PATIENTS

A total of 226 individuals diagnosed with unilateral definite SSNHL were hospitalized. The assessment included a comprehensive evaluation of medical history, pure-tone test, acoustic impedance, positional test, video nystagmography (VNG), vHIT, vestibular evoked myogenic potentials (VEMPs) and magnetic resonance.

INTERVENTIONS

vHIT, VNG, cVEMP, oVEMP. Statistical analysis was performed with SPSS version 22.0 for Windows.

MAIN OUTCOME MEASURES

The asymmetry values, gain, and pathological saccades of the vHIT.

RESULTS

The abnormal gain of vHIT in anterior, horizontal, and posterior canal in SSNHL patients with vertigo were revealed in 20 of 112 (17.9%), 24 of 112 (21.4%), and 60 of 112 (53.6%), respectively. The vHIT pathological saccades (overt + covert) of anterior, horizontal, and posterior canal in SSNHL patients with vertigo were observed in 5 of 112 (4.6%), 52 of 112 (46.4%), and 58 of 112 (51.8%), respectively. Multivariate analysis indicated that the prognosis of patients with vertigo was correlated with vHIT gain of posterior canal, pathological saccade in horizontal canal, asymmetric ratio of horizontal canal gain, asymmetric ratio of posterior canal gain, Canal paresis (%) on caloric test and spontaneous nystagmus.

CONCLUSION

In the vHIT of patients with SSNHL with vertigo, the posterior canal is most easily affected. Reduced gain of posterior canal, pathological saccade of horizontal canal, and larger asymmetric gain of posterior canal and horizontal canal may be negative prognostic factors.

Tumor shape as a prognostic factor for the growth of intracanalicular vestibular schwannoma: a long-term observational study

PURPOSE

To evaluate the predictive factors of tumor growth in patients with vestibular schwannoma (VS) managed with the wait-and-scan approach.

METHODS

The data of 31 patients diagnosed with intracanalicular VS and followed for > 5 years were retrospectively analyzed. VS was diagnosed according to MRI findings and tumor growth was monitored. Tumor growth was defined as an increase of 2 mm or more in the maximal tumor diameter. The association between the initial tumor size and shape and tumor growth was assessed.

RESULTS

Tumor growth was observed in 16 of 31 patients (51.6%) over a mean follow-up duration of 7.3 years. The initial tumor size was not statistically correlated with tumor growth. However, fusiform or cylindrical tumors exhibited higher growth rates than oval or round tumors. Additionally, a significant correlation was observed between cerebellopontine angle extension and tumor shape.

CONCLUSION

In this study, 51.6% of the patients with intracanalicular VS who were managed with the wait-and-scan strategy over a follow-up period of > 5 years showed tumor growth. Tumor shape, especially fusiform or cylindrical shape, was found to be a significant predictor of tumor growth.

Evaluation of Semicircular Canal Function Using Video Head Impulse Test in Patients With Peripheral Vestibular Disorders Without Nystagmus

Objectives This study aims to evaluate semicircular canal function using video head impulse test (vHIT) in patients with peripheral vestibular disorders without nystagmus. Methods Patients who underwent vHIT were enrolled in this study, and the proportion of abnormal findings on vHIT in patients without nystagmus was investigated. In addition, the results of vestibular testing were investigated in cases in which both vHIT and caloric testing were performed in patients without nystagmus. Results Forty-six patients (23.4%) of 197 patients who had no abnormal findings on the nystagmus tests, including the gaze nystagmus test, positional nystagmus test, and positioning nystagmus test, showed dysfunction in at least one semicircular canal on vHIT. The most frequent diagnosis was vestibular schwannoma (14/46, 30.4%), and cases with bilateral vestibular dysfunction were also included (12/46, 26.1%). A disorganized pattern of catch-up saccade was observed more frequently in patients with subjective symptoms of dizziness/vertigo compared to those without subjective symptoms. Although the sensitivity of vHIT was low compared to caloric testing, vHIT could detect isolated vertical canal dysfunction not detected by caloric testing. Conclusions vHIT is considered to be a useful test for patients without nystagmus, as vHIT could detect abnormalities in approximately one-quarter of patients without nystagmus. vHIT is considered to be one of the first tests to be performed following nystagmus testing, including the gaze nystagmus test, the positional nystagmus test, and the positioning nystagmus test. On the other hand, there are some cases in which vHIT shows no abnormality while caloric testing shows canal paresis. It is necessary to perform vHIT, bearing in mind that there are abnormalities that cannot be detected by vHIT alone.

Vestibular Assessment with the vHIT and Skull Vibration-Induced Nystagmus Test in Patients with Nonprogressive Vestibular Schwannoma

Background: Our primary objective was to monitor nonprogressive unilateral vestibular schwannomas (VSs) to assess the efficiency of rapid bedside examinations, such as the video head impulse test (vHIT) and skull vibration-induced nystagmus test (SVINT), in identifying vestibular damage. Methods: An observational study was conducted from March 2021 to March 2022 on all adult patients (>18 years old) with a confirmed nonprogressive VS (no active treatment). The SVINT (using a 100 Hz vibrator with two (SVINT2) or three (SVINT3) stimulation locations) and vHIT (for the six semicircular canals (SCCs)) were performed on all patients. The asymmetry of function between the vestibules was considered significant when the gain asymmetry was greater than 0.1. Rapid and repeatable assessment of VSs using two- and three-stimulation SVINT plus vHIT was performed to quantify intervestibular asymmetry. Results: SVINT3 and SVINT2 triggered VIN in 40% (24/60) and 65% (39/60) of patients, respectively. There was significant asymmetry in the vestibulo-ocular reflex (VOR), as shown by a VS-side gain < healthy-side gain in 58% (35/60) of the patients. Among the patients with significant gain asymmetry between the two vestibules according to the vHIT (VS-side gain < healthy-side gain), the proportion of patients expressing vestibular symptomatology was significantly greater than that of patients without any symptoms [67% (29/43) vs. 35% (6/17), respectively; p = 0.047]. Conclusions: The SVINT2 can be combined with the vHIT to form an interesting screening tool for revealing vestibular asymmetry. This work revealed the superiority of mastoid stimulation over vertex stimulation for SVINT in patients with unilateral vestibular loss.

Does Location of Intralabyrinthine Vestibular Schwannoma Determine Objective and Subjective Vestibular Function?

BACKGROUND AND OBJECTIVE

The incidence of intralabyrinthine schwannomas is increasing, and a growing attention is given to the detrimental effects on hearing function. On the contrary, the vestibular profile of intralabyrinthine vestibular schwannomas (VSs) is still not well understood. We aimed to investigate and report the observed relationships between the intralabyrinthine location of the schwannomas and objective and subjective vestibular profile of the patients.

METHODS

Retrospective cohort study of 20 consecutive individuals with sporadic intralabyrinthine schwannomas and grouped according to the intralabyrinthine location of the schwannomas. Vestibular testing consisted of the video head impulse test of all three semicircular canals, the caloric test, cervical and ocular vestibular evoked myogenic potentials, and the dizziness handicap inventory. A nonparametric unpaired t test was performed to compare groups, and Fisher's exact test was used for categorical data.

RESULTS

The median video head impulse test gains (lateral, anterior, posterior) were 0.40, 0.50, and 0.75 for intravestibular schwannomas and 0.93, 1.52, and 0.91 for intracochlear schwannomas ( p = 0.0001, p = 0.009, p = 0.33), respectively. Caloric unilateral weakness had a median of 100% for intravestibular schwannomas and 14% for intracochlear schwannomas ( p = 0.0001). The mean dizziness handicap inventory was 21 for intravestibular schwannomas and 1 for cochlear schwannomas ( p = 0.02). There were no significant differences in vestibular evoked myogenic potentials according to intralabyrinthine location.

CONCLUSION

By both objective and subjective measures, intralabyrinthine schwannomas with an intravestibular component has significantly worse vestibular function than schwannomas with purely cochlear involvement.

Audiovestibular Findings in Patients with Concurrent Superior Canal Dehiscence and Vestibular Schwannoma

OBJECTIVE

To describe the clinical-instrumental findings in case of concurrent superior canal dehiscence (SCD) and ipsilateral vestibular schwannoma (VS), aiming to highlight the importance of an extensive instrumental assessment to achieve a correct diagnosis.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Five patients with concurrent SCD and VS.

INTERVENTION

Clinical-instrumental assessment and imaging.

MAIN OUTCOME MEASURE

Clinical presentation, audiovestibular findings, and imaging.

RESULTS

The chief complaints were hearing loss (HL) and unsteadiness (80%). Other main symptoms included tinnitus (60%) and pressure-induced vertigo (40%). Mixed-HL was identified in three patients and pure sensorineural-HL in 1, including a roll-over curve in speech-audiometry in two cases. Vibration-induced nystagmus was elicited in all cases, whereas vestibular-evoked myogenic potentials showed reduced thresholds and enhanced amplitudes on the affected side in three patients. Ipsilesional weakness on caloric testing was detected in three patients and a bilateral hyporeflexia in one. A global canal impairment was detected by the video-head impulse test in one case, whereas the rest of the cohort exhibited a reduced function for the affected superior canal, together with ipsilateral posterior canal impairment in two cases. All patients performed both temporal bones HRCT scan and brain-MRI showing unilateral SCD and ipsilateral VS, respectively. All patients were submitted to a wait-and-scan approach, requiring VS removal only in one case.

CONCLUSION

Simultaneous SCD and VS might result in subtle clinical presentation with puzzling lesion patterns. When unclear symptoms and signs occur, a complete audiovestibular assessment plays a key role to address imaging and diagnosis.

Vestibular Tests Related to Tumor Volume in 137 Patients With Small to Medium-Sized Vestibular Schwannoma

OBJECTIVE

The video head impulse test (vHIT) and cervical and ocular vestibular evoked myogenic potentials (cVEMP and oVEMP) are new methods for measuring peripheral vestibular function. The objectives of this study were to compare these tests and the traditionally used caloric test in patients with small and medium-sized untreated vestibular schwannoma (VS) and to measure the correlation between the tests' results and tumor volume.

STUDY DESIGN

National cross-sectional study.

SETTING

Tertiary university clinic.

METHODS

Prevalence of abnormal cVEMP, oVEMP, caloric test, and 6-canal vHIT results on the tumor side and the nontumor side were compared and related to tumor volume with regression analyses in 137 consecutive VS patients assigned to a wait-and-scan protocol in the period 2017 to 2019.

RESULTS

The sensitivity of 6-canal vHIT, caloric test, cVEMP, and oVEMP to detect vestibulopathy in VS patients was 51%, 47%, 39%, and 25%, respectively. Normal tests were found in 21% of the patients. The results of vHIT and caloric test were related to tumor volume, but this was not found for cVEMP and oVEMP.

CONCLUSION

The caloric test and 6-canal vHIT showed the highest sensitivity in detecting vestibulopathy in untreated VS patients. vHIT, and particularly the posterior canal, was limited with a high prevalence of abnormal results on the nontumor side. A combination of cVEMP and caloric test was favorable in terms of a relatively high sensitivity and low prevalence of abnormal results on the nontumor side. Larger tumors had a higher rate of pathology on caloric testing and vHIT.

Vestibular Schwannoma: Long-term Outcome of the Vestibular Function After Stereotactic Radiosurgery

Objective

Evaluation at long term of the impact of the stereotactic surgery (SRS) on the vestibular function in vestibular schwannoma (VS) patients.

Study design and setting

Retrospective study in a tertiary referral center.

Patients

Fifty-one VS patients were included (34 females;17 males), aged from 41 to 78 years treated exclusively with SRS.

Intervention

Vestibular function was assessed before SRS and with median time interval of 14 (FU1) and 25 (FU2) months after treatment. Vestibular evaluation included: history, clinical vestibular examination, videonystagmography, head impulse test (v-HIT) and cervical vestibular evoked myogenic potentials (c-VEMPS).

Results

Before SRS, caloric testing (Caloric) was impaired in 77%; after treatment, in 92% (FU1) and 77% (FU2). Lateral HIT was decreased in 22% before SRS, in 39% at FU1 and FU2. C-VEMPS were absent in 50% before SRS, in 76% at FU1 and, FU2. Before SRS, no statistically significant association was found between asymptomatic and symptomatic patients with respect to the results of Caloric, v-HIT and c-VEMPS. This lack of association was also seen after SRS, at FU1 and FU2.

Conclusion

Our study showed that the impairment of the vestibular function might be attributed to the VS itself as well as to the radiation of the inner ear during SRS. The lateral SSC at low frequencies and the saccular function seem to be more involved with the time.

Impact of an Endolymphatic Sac Tumor on Subjective and Objective Audiovestibular Function

OBJECTIVE

This study reports subjective and objective audiovestibular function in patients diagnosed with an endolymphatic sac tumor (ELST), to evaluate the clinical implication of vestibular testing in ELST patients.

STUDY DESIGN

Retrospective cohort study.

SETTING

Tertiary referral center/university hospital.

PATIENTS

Five patients diagnosed with unilateral ELST.

INTERVENTION

Subjective and objective audiovestibular tests; pure-tone average; speech discrimination score; the Video Head Impulse Test; the cervical vestibular evoked myogenic potential test; the caloric irrigation test; the Speech, Spatial and Qualities of Hearing Scale; the Tinnitus Handicap Inventory; and the Dizziness Handicap Inventory.

MAIN OUTCOME MEASURE

Findings and characteristics of both subjective and objective audiovestibular functions.

RESULTS

The mean pure-tone average and the mean speech discrimination score were 49 dB HL and 68% on the tumor ear and 13 dB HL and 99% contralaterally. The mean Speech, Spatial and Qualities of Hearing Scale score was 84, and the mean Tinnitus Handicap Inventory score was 64. Caloric testing showed a mean unilateral weakness of 80%. The Video Head Impulse Test of the lateral semicircular canal revealed refixation saccades on all tumor ears and an average gain value of 0.75 on the tumor ear versus 0.94 contralaterally. No cervical vestibular evoked myogenic potentials were elicited on the tumor side, whereas all but one was elicited contralaterally. The average Dizziness Handicap Inventory score was 47.

CONCLUSION

A characteristic pattern of abnormal caloric findings, refixation saccades, and normal vestibulo-ocular reflex gain alongside sensorineural hearing loss on the tumor ear was identified. Asymmetric sensorineural hearing loss in any patient should lead to objective vestibular evaluation to strengthen not only a targeted tumor surveillance strategy and the indication for imaging, but also the design of vestibular rehabilitation. In addition, vestibular findings may guide the choice of surgical approach.

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.

[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.

Vestibular function testing in the 21st century: video head impulse test, vestibular evoked myogenic potential, video nystagmography; which tests will provide answers?

PURPOSE OF REVIEW

To most neurologists, assessing the patient with vertigo is an unpleasant and worrisome task. A structured history and focused examination can be complemented by carefully selected laboratory tests, to reach an early and accurate diagnosis. We provide evidence-based recommendations for vestibular test selection.

RECENT FINDINGS

The video head impulse test (vHIT), cervical and ocular vestibular evoked myogenic potential (VEMP) and home-video nystagmography are four modern, noninvasive methods of assessing vestibular function, which are equally applicable in the hospital and office-practice. Collectively, they enable assessment of all five vestibular end-organs. The prevalence and patterns of test abnormalities are distinct for each vestibular disorder. We summarize typical abnormalities encountered in four common vestibular syndromes.

SUMMARY

In the context of acute vestibular syndrome, an abnormal vHIT with low gain and large amplitude refixation saccades and an asymmetric oVEMP separates innocuous vestibular neuritis from stroke. In episodic spontaneous vertigo, high-velocity ictal nystagmus and asymmetric cVEMP help separate Ménière's disease from vestibular migraine. In chronic imbalance, all three tests help detect unilateral or bilateral vestibular loss as the root cause. Recurrent positional vertigo requires no laboratory test and can be diagnosed and treated at the bedside, guided by video nystagmography.

Evaluation of Vestibular Function in Diagnosis of Vestibular Schwannomas

Vestibular schwannomas (VS) are benign tumors of the vestibular nerve. The common first symptoms are hearing loss and tinnitus, followed by imbalance, vertigo, and facial nerve involvement. The subjective symptoms of VS patients are not consistent with the severity of vestibular lesions and the results of vestibular tests, which often interfere with clinicians' diagnoses. Thus, the main screening and diagnostic methods for VS are audiometry and magnetic resonance imaging (MRI), ignoring the evaluation of vestibular function at the source of pathological lesions. With the development and improvement of vestibular evaluation technology and its wide application in the clinic, modern vestibular examination technology can reflect the severity and frequency of vestibular lesions and compensation from multiple perspectives, providing an objective basis for the diagnosis and treatment of vestibular diseases. In this report, we review the results and characteristics of vestibular tests in VS patients and further clarify the clinical value of vestibular function assessment in the diagnosis and treatment of VS.

Feasibility of Preoperative Video Head Impulse Test to Predict the Nerve of Origin in Patients with Vestibular Schwannomas

Vestibular schwannoma (VS) originates from Schwann cells in the superior or inferior vestibular nerve. Identifying the precise origin will help in determining the optimal surgical approach. We retrospectively analyzed the preoperative vestibular function test according to VS origin to determine whether the test is a valuable indicator of tumor origin. Forty-seven patients with VS (male:female = 18:29, mean age: 54.06 ± 13.50 years) underwent the cochleovestibular function test (pure-tone audiometry, caloric test, video head impulse test (vHIT), cervical and ocular vestibular-evoked myogenic potential, and posturography). All patients then underwent surgical removal of VS, and the schwannoma origin was confirmed. The tumor originated from the superior vestibular nerve (SVN group) in 21 patients, the inferior vestibular nerve (IVN group) in 26 patients, and an undetermined site in eight patients. The only value that differed significantly among the groups was the gain of the vestibular-ocular reflex (VOR) in the ipsilesional posterior canal (iPC) during the vHIT. Our results indicate that VOR gain in the iPC may be used to predict the nerve origin in patients with VS. Other cochleovestibular function tests have limited value to discriminate nerve origins, especially in cases of medium to large VS.

Optimized preoperative determination of nerve of origin in patients with vestibular schwannoma

In vestibular schwannoma (VS) patients hearing outcome and surgery related risks can vary and depend on the nerve of origin. Preoperative origin differentiation between inferior or superior vestibular nerve may influence the decision on treatment, and the selection of optimal treatment and counselling modalities. A novel scoring system based on functional tests was designed to predict the nerve of origin for VS and was applied to a large number of consecutive patients. A prospective, double blind, cohort study including 93 patients with suspected unilateral VS was conducted at a tertiary referral centre. Preoperatively before tumor resection a functional test battery [video head-impulse test (vHIT) of all semicircular canals (SCC)], air-conducted cervical/ocular vestibular evoked myogenic potential tests (cVEMP, oVEMP), pure-tone audiometry, and speech discrimination was applied. Sensitivity and specificity of prediction of intraoperative finding by a preoperative score based on vHIT gain, cVEMP and oVEMP amplitudes and asymmetry ratios was calculated. For the prediction of inferior vestibular nerve origin, sensitivity was 73% and specificity was 80%. For the prediction of superior vestibular nerve origin, sensitivity was 60% and specificity was 90%. Based on the trade-off between sensitivity and specificity, optimized cut-off values of - 0.32 for cVEMP and - 0.11 for oVEMP asymmetry ratios and vHIT gain thresholds of 0.77 (anterior SCC), 0.84 (lateral SCC) and 0.80 (posterior SCC) were identified by receiver operator characteristic curves. The scoring system based on preoperative functional tests improves prediction of nerve of origin and can be applied in clinical routine.

Vestibular Screening Before Cochlear Implantation: Clinical Implications and Challenges in 409 Cochlear Implant Recipients

OBJECTIVE

Cochlear implantation (CI) carries a risk of loss of vestibular function following surgery. Thus, vestibular assessment presurgery is used to identify vestibulopathy that may contraindicate implantation and guide in selecting the candidate ear. The aim of this study was to evaluate the clinical implications of preoperative vestibular assessment, and to identify challenges in performing vestibular testing in patients with profound hearing loss, i.e., CI candidates.

STUDY DESIGN

Retrospective study of all CI recipients implanted since the introduction of a vestibular screening program.

SETTING

Tertiary referral center in 2013.

PATIENTS AND INTERVENTION

CI candidates routinely underwent testing with the video head impulse test (VHIT) and the cervical vestibular evoked myogenic potential (cVEMP) test as a part of the CI work up.

RESULTS

Three hundred thirty-five individuals were screened before the first CI and 74 individuals before the second CI. In 301 cases (73.6%), the vestibular function was considered normal and consequently carried no contraindications for surgery or implications for choice of ear to be implanted. Bilateral vestibular loss was found in 43 cases (10.5%) and unilateral vestibular loss was found in 62 cases (15.2%). In the latter cases, evaluation of multiple variables was indicated to select candidate ear. In nine implanted patients (2.2%), a relative contraindication to operate based on an "only balancing" ear was overruled by other factors. Vestibular testing was challenged by various factors (e.g., neck immobility, eye tracking issues, communication, and other patient issues), limiting the vestibular data output. This resulted in omittance, testing failure, or interpretation uncertainty 24 times (5.9%) for VHIT and 65 times (15.9%) for cVEMP.

CONCLUSION

Vestibular screening is an important part of the clinical workup with respect to selection of candidate ear for cochlear implantation, as 15.2% of CI candidates present with unilateral vestibulopathy. Challenges in performing the vestibular tests are not uncommon, as test failure occurred in 15.9% of cases for the cVEMP and 5.9% for the VHIT. The most common reasons for test failure were neck immobility, communication issues, and problems of pupil tracking.

Objective Vestibular Test Battery and Patient Reported Outcomes in Cochlear Implant Recipients

OBJECTIVE

Cochlear implantation (CI) may have undesired effects on the vestibular apparatus. However, the literature holds no consensus on vestibular affection and the testing tools applied to test for vestibular dysfunction after cochlear implantation are inconsistent. We aimed to investigate the impact of CI on vestibular function by an extensive test battery including patient-reported outcomes.

STUDY DESIGN

Prospective observational study.

SETTING

University hospital.

PATIENTS

Forty adult unilateral first-time CI recipients.

INTERVENTION

Vestibular function was evaluated pre- and post-implantation with the video head impulse test (VHIT), the caloric test and cervical vestibular evoked myogenic potentials (cVEMPs), and the patient-reported dizziness handicap inventory (DHI).

RESULTS

Mean VHIT gain decreased from preoperative 0.92 to 0.84 postoperative (p = 0.018); mean caloric unilateral weakness increased from 20.5% preoperative to 42.9% postoperative (p < 0.0001); cVEMP responses were present on 10 operated ears preoperative and five ears postoperative, and compared with non-implanted ears, cVEMP responses on implanted ears were impaired (p = 0.023). 50% of patients reported early postoperative dizziness, but the mean DHI score remained unchanged (p = 0.94). The DHI scores correlated poorly with the objective outcomes (rs = 0.19 and rs = -0.22).

CONCLUSION

Vestibular function is significantly affected after cochlear implantation, but vestibular hypofunction varies with the test used. Although early dizziness after implantation is common, later DHI scores are not significantly higher than before the implantation, indicating that central compensation plays a major role for these patients.

[Hearing classification in patients with vestibular schwannoma using German-language test procedures]

BACKGROUND

Hearing function in patients with vestibular schwannoma is often classified according to the Gardner and Robertson (1988) or the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS, 1995) systems. These classification systems are based on English-language test procedures, there is no German-language equivalent. The aim of the study was to investigate the influence of various target parameters on hearing classification and to derive a recommendation for the use of German-language test methods.

MATERIALS AND METHODS

The rules for speech audiometry based on English-language test procedures were applied to German speech test materials. In 91 patients with vestibular schwannoma, pure tone hearing thresholds, speech recognition thresholds, and speech discrimination at different sound pressure levels were measured. The patients were categorized according to the Gardner and Robertson and AAO-HNS classifications.

RESULTS

In both the Gardner-Robertson and the AAO-HNS classifications, the number of patients in the hearing classes with serviceable hearing function (measured as Pure Tone Average across three (3PTA) or four (4PTA) frequencies) was highest when using the 3PTA_{0,5;1;2 kHz} condition, followed by 4PTA_{0,5;1;2;3 kHz}, 4PTA_{0,5;1;2;4 kHz}, and 4PTA_{0,5;1;2;"3"kHz}. If maximum word recognition score (WRS_max) was used instead of word recognition 40 dB above the sensation level (WRS_40SL), more patients were classified into the hearing classes with serviceable hearing function, irrespective of the mean pure tone hearing threshold.

CONCLUSION

The Gardner-Robertson and AAO-HNS classifications can be used in German-speaking settings. The Freiburg monosyllabic test can be used to determine speech discrimination scores or maximum word recognition.

[Effective diagnostics for vertigo, dizziness and equilibrium disorders]

Vertigo, dizziness and equilibrium disorders are symptoms with a variety of causes. First, four cardinal questions (type and duration of the vertigo, triggering factors, accompanying symptoms) must be answered. After that, the search for a spontaneous nystagmus (differentiation of peripheral and central disorder using the HINTS[head impulse, nystagmus, test of skew]-test ) and, as part of a positioning examination, the search for a benign paroxysmal positional vertigo (BPPV) are necessary. If the result is negative an instrument-based receptor-specific examination is carried out. The caloric examination (low-frequency stimulus) tests the horizontal semicircular canal and the superior vestibular nerve, whereas the 3‑D video head impulse test (vHIT, high-frequency stimulus) is used to analyze all three semicircular canals as well as the superior and inferior vestibular nerves. Analysis of the cervical vestibular evoked myogenic potential (cVEMP) checks the function of the sacculus and that of the ocular VEMP (oVEMP) checks the function of the utriculus. The final overall analysis usually gives a definitive diagnosis or at least provides a suspected diagnosis, which then determines the further diagnostic procedure (e.g. targeted radiological diagnostics if vestibular paroxysmia, superior canal dehiscence or a vestibular schwannoma are suspected).

Functional Loss After Meningitis-Evaluation of Vestibular Function in Patients With Postmeningitic Hearing Loss

Introduction: The inner ear vestibular system is essential to balance function. Although hearing loss is well-described and quite common following meningitis, the literature evaluating vestibular function following meningitis is very limited. In particular, information on results of contemporary vestibular function tests, e.g., the video head impulse test (VHIT), is scarce. Using contemporary vestibular function tests, this study examines the vestibular function of patients with profound hearing loss (HL) after meningitis. Methods: Review of the literature and retrospective controlled study. Patients: Twenty-one consecutive patients with profound HL after meningitis (cochlear implant candidates) matched with 20 patients with profound HL of unknown etiology and examined during the period 2013-2018. Outcome Measure: Vestibular function loss, as evaluated with VHIT vestibulo-ocular reflex (VOR) gain, eye movement saccades, and cervical vestibular-evoked myogenic potentials (cVEMPs). The results of these tests were correlated to inner ear imaging findings (MRI/CT) and the level of hearing loss. Results: Mean VHIT gain was 0.48 in the meningitis group compared to 0.86 in the control group (p < 0.01). Saccades were present in 21 ears (62%) in the meningitis group compared to six ears (15%) among the controls (p < 0.01). cVEMP responses were present on five ears (18%) in the meningitis group and 25 ears (66%) in the control group (p < 0.01). Discussion: Postmeningitic hearing loss is associated with poor vestibular function, as evaluated by VHIT, saccades, and cVEMP. Loss of vestibular function correlates with the degree of hearing loss and inner ear imaging findings, although not in all cases. Vestibular function should be examined in patients surviving meningitis with hearing loss in order to individualize rehabilitation and improve balance outcome.

Comparison of test results from two separate video head impulse test systems in a cohort of patients diagnosed with a unilateral vestibular schwannoma

PURPOSE

Video head impulse testing (vHIT) is a relatively new technology enabling evaluation of vestibular function. The aim of this study was to compare the test results from two separate vHIT systems in a group of patients diagnosed with a unilateral vestibular schwannoma (VS) with regards to sensitivity, specificity and inter-examiner differences.

METHODS

Forty-two patients were examined with two separate vHIT systems: EyeSeeCam^® (system A) and ICS Impulse^® (system B), by one of two examiners. All six semicircular canals (SCCs) were tested under standardized conditions, and strict criteria were set up for post-test interpretation.

RESULTS

With the majority of test parameters, the two test systems were in agreement. Vestibular deficits were found in 40.5% (system A) to 45% (system B) of patients with a VS on the tested side; corresponding to a positive predictive value (PPV) of 86.4% (system B) to 94.4% (system A). The specificity was 97.6% for system A and 92.9% for system B. An overall agreement between the two vHIT systems measured as kappa was computed to be 0.61. There were no significant inter-examiner differences. When testing the vertical SCCs, a tendency of too high mean gain values was seen with system A but not with system B.

CONCLUSION

In patients with unilateral VS, vHIT is a test with moderate sensitivity and high specificity in regard to identification of a vestibular deficit. There were no significant differences in test results between the two vHIT systems.