Catch-Up Saccades in Vestibular Hypofunction: A Contribution of the Cerebellum?

Long-term deficits of the vestibulo-ocular reflex (VOR) elicited by head rotation can be partially compensated by catch-up saccades (CuS). These saccades are initially visually guided, but their latency can greatly decrease resulting in short latency CuS (SL-CuS). It is still unclear what triggers these CuS and what are the underlying neural circuits. In this study, we aimed at evaluating the impact of cerebellar pathology on CuS by comparing their characteristics between two groups of patients with bilateral vestibular hypofunction, with or without additional cerebellar dysfunction. We recruited 12 patients with both bilateral vestibular hypofunction and cerebellar dysfunction (BVH-CD group) and 12 patients with isolated bilateral vestibular hypofunction (BVH group). Both groups were matched for age and residual VOR gain. Subjects underwent video head impulse test recording of the horizontal semicircular canals responses as well as recording of visually guided saccades in the step, gap, and overlap paradigms. Latency and gain of the different saccades were calculated. The mean age for BVH-CD and BVH was, respectively, 67.8 and 67.2 years, and the mean residual VOR gain was, respectively, 0.24 and 0.26. The mean latency of the first catch-up saccade was significantly longer for the BVH-CD group than that for the BVH group (204 ms vs 145 ms, p < 0.05). There was no significant difference in the latency of visually guided saccades between the two groups, for none of the three paradigms. The gain of covert saccades tended to be lower in the BVH-CD group than in BVH group (t test; p = 0.06). The mean gain of the 12° or 20° visually guided saccades were not different in both groups. Our results suggest that the cerebellum plays a role in the generation of compensatory SL-CuS observed in BVH patients.

Evidence for the differential efficacy of yaw and pitch gaze stabilization mechanisms in people with multiple sclerosis.

People with multiple sclerosis (PwMS) who report dizziness often have gaze instability due to vestibulo-ocular reflex (VOR) deficiencies and compensatory saccade (CS) abnormalities. Herein, we aimed to describe and compare the gaze stabilization mechanisms for yaw and pitch head movements in PwMS. Thirty-seven PwMS (27 female, mean ± SD age = 53.4 ± 12.4 years old, median [IQR] Expanded Disability Status Scale Score = 3.5, [1.0]. We analyzed video head impulse test results for VOR gain, CS frequency, CS latency, gaze position error (GPE) at impulse end, and GPE at 400 ms after impulse start. Discrepancies were found for median [IQR] VOR gain in yaw (0.92 [0.14]) versus pitch-up (0.71 [0.44], p < 0.001) and pitch-down (0.81 [0.44], p = 0.014]), CS latency in yaw (258.13 [76.8]) ms versus pitch-up (208.78 [65.97]) ms, p = 0.001] and pitch-down (132.17 [97.56] ms, p = 0.006), GPE at impulse end in yaw (1.15 [1.85] degs versus pitch-up (2.71 [3.9] degs, p < 0.001), and GPE at 400 ms in yaw (-0.25 [0.98] degs) versus pitch-up (1.53 [1.07] degs, p < 0.001) and pitch-down (1.12 [1.82] degs, p = 0.001). Compared with yaw (0.91 [0.75]), CS frequency was similar for pitch-up (1.03 [0.93], p = 0.999) but lower for pitch-down (0.65 [0.64], p = 0.023). GPE at 400 ms was similar for yaw and pitch-down (1.88 [2.76] degs, p = 0.400). We postulate that MS may have preferentially damaged the vertical VOR and saccade pathways in this cohort.

Vestibular function assessment in Idiopathic sudden sensorineural hearing loss: a prospective study.

PURPOSE: Idiopathic sudden sensorineural hearing loss (ISSHL) can cause acute damage not only to the auditory function, but also to the vestibular function in addition to damage to the hearing function. The aim of this study was to perform vestibular assessment using caloric test and video head impulse test in patients with idiopathic sudden sensorineural hearing loss. In addition, to evaluate the relationship of dizziness with vestibular tests and post-treatment responses of vestibular tests. METHODS: This is an observational, longitudinal and prospective study, including patients diagnosed with idiopathic sudden sensorineural hearing. Patients were divided into two groups according to the presence of vestibular complaints at presentation: Group 1: Patients with vestibular complaints, Group 2: Patients without vestibular complaints. All subjects underwent pure tone audiometry (PTA) testing, cold caloric test and video head impulse test (vHIT) during their admission and on the 10th day, 3rd month, and 1st year of their follow-up outpatient clinic controls. A unilateral weakness (UW) in the caloric test response was quantified according to the Jongkees formula. RESULTS: A positive and significant relationship was found between the degree of hearing loss according to the ASHA criteria pre-treatment and the level of improvement created according to Siegel criteria at the 10th day, 3rd month, 1st year after treatment (respectively p = 0.001, p = 0.001, p < 0.001). When both short-term and long-term results were evaluated after treatment, a positive improvement in the degree of hearing loss was observed. A statistically significant difference was observed between Groups 1 and 2 when the pre-treatment, at 10 days, 3 months and 1 year after treatment the caloric test UW value was compared (respectively p = 0.020, p = 0.004, p = 0.004, p = 0.004). A statistically significant difference was observed between Groups 1 and 2 when the pre-treatment, at 10 days, 3 months and 1 year after treatment vHIT lateral canal VOR value was compared (respectively p = 0.000, p = 0.001, p = 0.000, p = 0.004). When both short-term and long-term results were evaluated after treatment, a positive improvement was observed in both caloric test results and lateral vHIT VOR values. Pre-treatment, post-treatment 10th day, 3rd month, 1st year vHIT anterior and posterior canal VOR values were found to be VOR˃0.8 in all patients. No difference was observed in anterior and posterior canal VOR values. CONCLUSION: Vertigo in patients with ISSHL "as objectively confirmed through caloric testing and vHIT" can be considered a sign of severe cochlear damage. Our study demonstrated a significantly increased risk of vestibular affect in patients with ISSHL, especially in the presence of vertigo. Thus, we conclude that the focus in ISSHL should not only be on the cochlea but also on the vestibular system.

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

PURPOSE: When a dizzy patient with episodic vertigo has an abnormal caloric and a normal video head impulse test (vHIT), this caloric-vHIT dissociation provides vital information for a diagnosis of Ménière's disease (MD). Endolymphatic hydrops (EH), a histological marker of MD, is hypothesized to be involved in the caloric-vHIT dissociation in MD through hydropic duct distension of the horizontal semicircular canal (SC). This study was designed to determine the impact of EH on the function of horizontal SC during caloric stimulation. METHODS: Caloric test and vHIT were used to evaluate the function of horizontal SC every six months, annual magnetic resonance imaging (MRI) was used to evaluate the degree of EH size in the vestibule, and monthly vertigo and hearing evaluation was done for 12 months. EH shrinkage was defined as the size change of vestibular EH from significant to none. RESULTS: Among 133 MD patients evaluated for eligibility, 67 patients with caloric-vHIT dissociation entered the study. Fifteen participants had EH shrinkage (G-I), while 52 participants had no remarkable EH change (G-II). Average values (IQR) of the maximum slow phase velocity in G-I and G-II were 29.6 (13.0-34.0) and 25.9 (17.3-31.3), respectively, at baseline, 26.1 (9.0-38.0) and 23.6 (18.0-28.3) at 12 months. Two-factor repeated-measures ANOVA showed no significant differences between the groups (P = 0.486). The values of vestibulo-ocular reflex gain of the horizontal SC in G-I and G-II remained above 0.8 during the study period. CONCLUSIONS: EH detected by MRI shows limited correlation with caloric stimulation results.

Preliminary Evidence for the Effects of Gentamicin on Vertical Semicircular Canals.

INTRODUCTION: Gentamicin is a vestibulotoxic antibiotic often used in patients with Ménière's disease for its vestibular ablative effects. Gentamicin's effect on the horizontal semicircular canal does not always correlate with the degree of vertigo control achieved by patients; its effect on the vertical semicircular canals remains unknown. We sought to examine the effect of intratympanic gentamicin on vertical semicircular canal function in patients with Ménière's disease using video head impulse testing. METHODS: A retrospective case series was carried out at a tertiary academic center. Patients with Ménière's disease who received ≥1 intratympanic gentamicin injection from 2019-2022 and had video head impulse testing performed were included. Outcomes of interest were vertical semicircular canal function following intratympanic gentamicin, correlations between vertical semicircular canal function and horizontal semicircular canal function, and residual symptoms following injection. RESULTS: Ten patients met inclusion criteria. Twenty percent had abnormal V-SCC function prior to any injection and 40% following the first injection. There was an association between abnormal vertical and horizontal semicircular canal function following the first intratympanic gentamicin injection, though the relationship did not reach statistical significance (p = 0.058). While patients with abnormal vertical semicircular canal function following the first injection were less likely to report ongoing vertigo attacks, the relationship was not statistically significant (p = 0.260). CONCLUSIONS: Intratympanic gentamicin leads to changes in vertical semicircular canal function in at least a proportion of patients with Ménière's disease. Further study is required to better assess correlations between vertical semicircular canal function and symptom control following intratympanic gentamicin.

Meta-Analysis of the Use of Head Impulse Test and Head Impulse Test with Direction Changing Nystagmus and Test of Skew Deviation in the Diagnosis of Peripheral Vertigo and Stroke.

INTRODUCTION: The head impulse test (HIT) and HIT combined with direction-changing Nystagmus-Test of Skew deviation (HINTS) have been proposed as bedside tests to differentiate between peripheral and central causes of vertigo in the emergency department (ED). We conducted a meta-analysis of the HIT and HINTS tests to diagnose peripheral vertigo (PV) and central vertigo. METHODS: Pubmed, Google Scholar, EmBase, and articles references published in English up to July 2021 were searched for keywords "vertigo" or "acute vestibular syndrome" or "dizziness" and "head impulse" and "stroke." The bivariate method for meta-analysis was used to calculate positive (PLR) and negative likelihood ratios (NLR) and summary receiver operating characteristics area under the curve (AUC). RESULTS: A total of 11 studies were included analysing both HIT (8 studies, N = 417) and HINTS (6 studies, N = 405). HIT and HINTS were performed within 24 h in 4 of 11 studies. PLR and NLR for HIT in PV was 4.85 (95% CI: 2.83-8.08) and 0.19 (95% CI: 0.12-0.29, I2 63.25%), respectively. The AUC for HIT the diagnosis of PV and stroke was 0.90 and 0.92, respectively. PLR and NLR for a negative HIT in stroke was 5.85 (95% CI: 3.07-10.6) and 0.17 (95% CI: 0.08-0.30), respectively. PLR and NLR for peripheral HINTS pattern for PV was 17.3 (95% CI: 8.38-32.1) and 0.15 (95% CI: 0.07-0.26), respectively. PLR and NLR for central HINTS pattern for stroke: 5.61 (95% CI: 4.19-7.7) and 0.06 (95% CI: 0.03-0.12). In all included studies, HIT and HINTS exams were administered by neurology residents or neurology specialists with additional neuro-otology or neuro-ophthalmology subspeciality experience, and two studies included ED physicians. Raters reported high degree of bias and high concern regarding applicability in most domains of the quality assessment of diagnostic accuracy studies (QUADAS-2) tool. Meta-regression did not demonstrate a statistically significant effect of publication year, time to test, and type of assessor on sensitivity or false positive rate. CONCLUSION: The HIT and HINTS exams appear to be moderately good discriminators of central and PV. However, in most papers, the tests were administered by neurologists and were evaluated beyond 24 h, which may limit utility in the ED setting.

Pediatric Vestibular Assessment: Clinical Framework.

OBJECTIVES: Although vestibular deficits can have severe repercussions on the early motor development in children, vestibular assessment in young children has not yet been routinely integrated in clinical practice and clear diagnostic criteria to detect early vestibular deficits are lacking. In young children, specific adjustments of the test protocol are needed, and normative data are age-dependent as the vestibular pathways mature through childhood. Therefore, this study aims to demonstrate the feasibility of an extensive age-dependent vestibular test battery, to provide pediatric normative data with the concurrent age trends, and to offer a clinical framework for pediatric vestibular testing. DESIGN: This normative study included 133 healthy children below the age of 4 years (mean: 22 mo, standard deviation: 12.3 mo, range: 5-47 mo) without history of hearing loss or vestibular symptoms. Children were divided into four age categories: 38 children younger than 1 year old, 37 one-year olds, 33 two-year olds, and 25 three-year olds. Children younger than 3 years of age were examined with the video Head Impulse Test (vHIT) of the horizontal semicircular canals, cervical vestibular evoked myogenic potentials (cVEMP) with bone conduction stimuli, and the rotatory test at 0.16, 0.04, and 0.01 Hz. In 3-year old children, the vHIT of the vertical semicircular canals and ocular vestibular evoked myogenic potentials (oVEMP) using a minishaker were added to the protocol. RESULTS: The horizontal vHIT appeared to be the most feasible test across age categories, except for children younger than 1-year old in which the success rate was the highest for the cVEMP. Success rates of the rotatory test varied the most across age categories. Age trends were found for the vHIT as the mean vestibulo-ocular reflex (VOR) gain increased significantly with age (r = 0.446, p < 0.001). Concerning the cVEMP, a significant increase with age was found for latency P1 (r = 0.420, p < 0.001), rectified interpeak amplitude P1-N1 (r = 0.574, p < 0.001), and averaged electromyographic (EMG) activity (r = 0.430, p < 0.001), whereas age trends for the latency N1 were less pronounced (r = 0.264, p = 0.004). Overall, the response parameters of the rotatory test did not show significant age effects ( p > 0.01), except for the phase at 0.01 Hz (r = 0.578, p < 0.001). Based on the reported success rates and age-dependent normative vestibular data, straightforward cutoff criteria were proposed (vHIT VOR gain < 0.7, cVEMP rectified interpeak amplitude < 1.3, oVEMP interpeak amplitude < 10 µV) with accompanying clinical recommendations to diagnose early vestibular impairment. CONCLUSIONS: In this large cohort of typically developing children below the age of 4 years, the vHIT and cVEMP were the most feasible vestibular tests. Moreover, the age-dependent normative vestibular data could specify age trends in this group of young children. Finally, based on the current results and clinical experience of more than ten years at the Ghent University Hospital (Belgium), a clinical framework to diagnose early vestibular deficits in young patients is proposed.

Vestibular Infant Screening-Flanders: What is the Most Appropriate Vestibular Screening Tool in Hearing-Impaired Children?

OBJECTIVES: As children with sensorineural hearing loss have an increased risk for vestibular impairment, the Vestibular Infant Screening-Flanders project implemented a vestibular screening by means of cervical vestibular evoked myogenic potentials (cVEMP) at the age of 6 months for each child with hearing loss in Flanders (Belgium). Given that vestibular deficits can affect the child's development, this vestibular screening should allow early detection and intervention. However, less is currently known about which screening tool would be the most ideal and how vestibular impairment can evolve. Therefore, this study aimed to determine the most appropriate tool to screen for vestibular deficits, to assess the necessity of vestibular follow-up, and to set clinical guidelines for vestibular screening in children with hearing loss. DESIGN: In total, 71 children with congenital or early-onset sensorineural hearing loss were enrolled (mean age at first appointment = 6.7 months). Follow-up was provided at 6 months, 1, 2, and 3 years of age. Below three years of age, the video Head Impulse Test (vHIT) of the horizontal semicircular canals (SCC), the cVEMP, and the rotatory test at 0.16, 0.04, and 0.01 Hz were applied. At 3 years of age, the vHIT of the vertical SCC and ocular vestibular evoked myogenic potentials (oVEMP) were added. To evaluate early motor development, the Alberta Infant Motor Scale (AIMS) results at 6 months and 1-year old were included. RESULTS: At 6 months of age, the highest success rate was obtained with the cVEMP (90.0%) compared to the vHIT (70.0%) and the rotatory test (34.3-72.9%). Overall, vestibular deficits were found in 20.0% of the children, consisting of 13.9% with both SCC and otolith deficits (bilateral: 9.3%, unilateral: 4.6%), and 6.1% with unilateral isolated SCC (4.6%) or otolith (1.5%) deficits. Thus, vestibular deficits would not have been detected in 4.6% of the children by only using the cVEMP, whereas 1.5% would have been missed when only using the vHIT. Although vestibular deficits were more frequently found in severe to profound hearing loss (28.6%), characteristics of vestibular function were highly dependent on the underlying etiology. The AIMS results showed significantly weaker early motor development in children with bilateral vestibular deficits ( p = 0.001), but could not differentiate children with bilateral normal vestibular function from those with unilateral vestibular deficits ( p > 0.05). Progressive or delayed-onset vestibular dysfunction was only found in a few cases (age range: 12-36 months), in which the hearing loss was mainly caused by congenital cytomegalovirus (cCMV). CONCLUSIONS: The cVEMP is the most feasible screening tool to assess vestibular function in 6-months-old children with hearing loss. Although the majority of children with vestibular deficits are detected with the cVEMP, the vHIT seems even more sensitive as isolated SCC deficits are associated with specific etiologies of hearing loss. As a result, the cVEMP is an appropriate vestibular screening tool, which is advised at least in severe to profound hearing loss, but certain etiologies require the addition of the vHIT (i.e., cCMV, meningitis, cochleovestibular anomalies with or without syndromic hearing loss).

An evaluation of the test-retest reliability of the functional head impulse test in healthy young adults.

AIM: To determine the test and retest reliability of the functional head impulse test (fHIT) in healthy young adults. MATERIALS AND METHODS: Thirty-three healthy participants (17 women, 16 men) aged 18-30 years were included in the study. Each participant underwent the fHIT twice, 1 week apart, by the same experienced clinician. Intraclass correlation coefficients (ICCs) were used to determine test-retest reliability. RESULTS: There was no statistically significant difference between the results of total percentage of correct answer (CA%) of the fHIT obtained in session 1 and session 2 measurements in the lateral, anterior, and posterior semicircular canals (SCCs) (p > 0.05). ICC values for test-retest reliability were found to range from 0.619 to 0.665 for the three semicircular canals (SCCs). CONCLUSION: The test-retest reliability of the fHIT device was moderate. Attention, cognition, and fatigue may be the factors reducing reliability. In the diagnosis, follow-up, and rehabilitation processes of vestibular diseases in clinics, changes in the fHIT CA% can be used to assess vestibulo-ocular reflex (VOR) functionality.

Evaluation of postural stability and vestibulo-ocular reflex in adults with chronic suppurative otitis media.

PURPOSE: To evaluate the vestibulospinal reflex and vestibulo-ocular reflex (VOR) in patients with chronic suppurative otitis media (CSOM) using posturography and the video head impulse test (vHIT). METHODS: Sixty-five patients with CSOM and 65 healthy participants as controls were included. Patients with CSOM were instructed to complete the dizziness handicap inventory (DHI). All participants underwent otoscopy, pure-tone audiometry, posturography sensory organization test (SOT), and vHIT. RESULTS: Patients with CSOM exhibited a high prevalence of dizziness. The CSOM group had poor SOT vestibular scores compared to the control group. Patients with CSOM had worse sways in the antero-posterior and mediolateral planes. The CSOM group was divided into two subgroups according to the type of hearing loss. SOT vestibular scores were significantly poorer in the mixed hearing loss group than those in the conductive hearing loss group. We found a positive correlation between disease duration and poor SOT vestibular scores. Moreover, poor SOT vestibular scores correlated with high DHI scores. We found abnormalities in the vHIT results in the CSOM group in the form of low VOR gain and corrective saccades. CONCLUSION: Our study provides clinical evidence of dizziness, poor postural control, and VOR abnormalities in patients with CSOM. The presence of sensory elements of hearing loss in patients with CSOM appears to be positively associated with vestibular dysfunction.

Comparison between caloric and video-head impulse tests in Ménière's disease and vestibular neuritis.

OBJECTIVE: To compare the diagnostic accuracies of air caloric testing with electronystagmography and the vHIT (video-head impulse test). DESIGN: Prospective, controlled study. STUDY SAMPLE: MD (Ménière's disease), 26; vestibular neuritis, 27; control, 56. RESULTS: In MD, CP (canal paresis) was pathological in 88.5%, the GA (gain asymmetry) on vHIT was pathological in 65.3%, and the gain was abnormal in only one patient. The GA and CP, were significantly higher in the MD group than in the control group, indicating hypofunction of the horizontal canals in MD, whereas a hyperfunction may also occur. No correlation was observed between the results of the two tests for evaluating MD, suggesting that pathological outcomes of one test do not guarantee abnormalities on the other test. For vestibular neuritis, significantly higher CP (96.3%), GA (81.5%), and gain (51.9%) values were detected. A correlation was identified between the two tests for vestibular neuritis, indicating a similar diagnostic efficiency. The higher percentage of pathological GA versus pathological gain values indicates that the asymmetry may be more informative. CONCLUSIONS: The vHIT showed a higher specificity, whereas the caloric test a higher sensitivity. No correlation between the two methods was observed; therefore, the tests appear to provide complementary information.

Role of the functional head impulse test in evaluating vestibulo-ocular reflex abnormalities in individuals with Parkinson's disease.

PURPOSE: To assess vestibular-ocular reflex (VOR) function in patients with Parkinson's disease (PD) using a new method called functional head impulse test (fHIT). STUDY DESIGN: Case-control study. SETTING: Tertiary medical center. PARTICIPANTS: Twenty individuals with PD were recruited for PD group, and twenty healthy individuals for the control group. Ages of both groups ranged from 47 to 76 years. MAIN OUTCOME MEASURES: According to the modified Hoehn-Yahr score, PD group was classified as an early stage with a range of 1-2.5 and a mid-late stage with a range of 3-5. Percentage of correct answers (%CA) was calculated using fHIT for lateral, anterior and posterior semicircular canal (SCC) planes. RESULTS: PD group had statistically lower fHIT %CA in the right lateral, left lateral, and left posterior SCC planes compared to control group (p < .05). There was no statistical difference between two PD severity groups and functional VOR abnormality. CONCLUSION: It was concluded that the functional VOR in the right lateral and left lateral and left posterior SCC plane was affected in individuals with PD. Our results show that impaired VOR and reduced dynamic visual acuity should be considered in individuals with PD for vestibular rehabilitation exercises.

The feasibility of SHIMP for judging subjective vertigo and recovery in patients with vestibular neuritis.

PURPOSE: We aimed to study the results of the head impulse paradigm (HIMP) and the suppression head impulse paradigm (SHIMP) in patients with acute vestibular neuritis (AVN) to compare dizziness handicap inventory (DHI) scores before and after treatment. We also wanted to investigate the correlation between the HIMP, SHIMP and DHI score and to analyze the factors that affect the recovery with AVN in the short term. METHODS: The HIMP, SHIMP, and DHI score were assessed in 20 patients with AVN before (T0) and after treatment (T1). We collected the following indicators: T0, T1-HIMP VOR gain; T0, T1-SHIMP VOR gain; the percentage of the anti-compensatory saccades of T0-SHIMP and T1-SHIMP on the affected side; T0-DHI score, T1-DHI score; and efficacy index (EI). The correlation between HIMP and SHIMP parameters with the DHI score and EI was analyzed, and the factors that affect the recovery of patients with AVN were assessed. RESULTS: T0-SHIMP anti-compensatory saccades (%),T1-SHIMP VOR gain, and T1-SHIMP anti-compensatory saccades (%) were significantly correlated with the corresponding DHI score and EI (P < 0.05). T0, T1-HIMP VOR gain and T0-SHIMP VOR gain had no correlation with the corresponding DHI score and EI (P > 0.05). T0-SHIMP anti-compensatory saccades (%) significantly affect EI (P < 0.05). CONCLUSION: Both HIMP and SHIMP can assess the current vestibular function and recovery of AVN patients, but SHIMP can more accurately reflect the degree of subjective vertigo. At the same time, T0-SHIMP anti-compensatory saccades (%) can be used as a good index to evaluate the short-term recovery of AVN patients.

The clinical significance of fHIT in migraine patient without vertigo symptom.

OBJECTIVE: The aim of this study was to assess the functional head impulse test on migraine patients without vertigo. fHIT is a new vestibular test which evaluates the ability to see and read clearly during head movement as a functional measurement of the vestibulo-ocular reflex. MATERIALS AND METHODS: The study included 20 patients suffering from migraine without vertigo between the ages of 20 and 30-years-old who were diagnosed by a neurologist and 20 individuals with non-migraine headaches (control group), with similar demographic characteristics. The functional head impulse test was applied to both groups, and the migraine disability assessment test was applied to migraine patients. RESULTS: There was no statistically significant difference in the general fHIT results between the migraine group and the control group (p > 0.05). However, a statistically significant decrease was obtained in migraine patients in the left lateral (p = 0.018) and right posterior (p = 0.029) semicircular canals at 4000 Hz and the right anterior semicircular canal at 6000 Hz (p = 0.019). When compared by the degree of migraine disability assessment test, no significant difference in the fHIT results were observed (p > 0.05). CONCLUSION: The semicircular canals may be affected at high head acceleration (4000-6000 Hz) in migraine patients without a history of vertigo. It should be considered that fHIT results between 4000 and 6000 Hz in migraine patients without vertigo can be pathologic.

Concordance of vestibular test batteries in patients with vestibular neuritis.

BACKGROUND: A growing number of vestibular function tests are utilized to differentiate and verify the diagnosis of vestibular neuritis. The aim of this study is to retrospectively investigate the consistency of the results of the objective vestibular test batteries in patients with a preliminary diagnosis of vestibular neuritis. METHODS: We reviewed a total of 37 adult patients (mean age: 39.03 ± 11.67, 19 females, 18 males) who met the inclusion criteria with a prediagnosis of vestibular neuritis from 379 patients suffering vestibular symptoms. Caloric test (CVT), video head impulse test (vHIT), and ocular and cervical VEMP tests were compared with Cohen's kappa (Κ) analysis according to the likely affected part of the vestibular nerve. RESULTS: The highest statistically significant K value was found between horizontal vHIT and ocular VEMP (K = 0.707; good grade, p < 0.05). All the tests compared with CVT were poorly in agreement (K = 0.288; 0.262; 0.256 for HvHIT, oVEMP, AvHIT, respectively, p < 0.05). DISCUSSION: VEMP and vHIT tests have prominent diagnostic value and agree with each other for detecting and differentiating the types of vestibular neuritis. Further studies should aim to include cutting-edge technologies such as functional HIT and ocular counter roll test.

[Dissociation of the results of caloric and video head impulse tests as a marker of Meniere's disease]. / Dissotsiatsiya kaloricheskogo i videoimpul'snogo testov u patsientov s bolezn'yu Men'era.

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.

Genotype-Phenotype Correlation Study in a Large Series of Patients Carrying the p.Pro51Ser (p.P51S) Variant in COCH (DFNA9) Part II: A Prospective Cross-Sectional Study of the Vestibular Phenotype in 111 Carriers.

INTRODUCTION: DFNA9 is characterized by adult-onset hearing loss and evolution toward bilateral vestibulopathy (BVP). The genotype-phenotype correlation studies were conducted 15 years ago. However, their conclusions were mainly based on symptomatic carriers and the vestibular data exclusively derived from the horizontal (lateral) semicircular canal (SCC). The last decade was marked by the emergence of new clinical diagnostic tools, such as the video head impulse test (vHIT) and vestibular-evoked myogenic evoked potentials (VEMPs), expanding our evaluation to all six SCCs and the otolith organs (saccule and utricule). AIM: The aim of this study was to comprehensively evaluate vestibular function in the largest series presymptomatic as well as symptomatic p.P51S variant carriers, to determine which labyrinthine part shows the first signs of deterioration and which SCC function declines at first and to determine the age at which p.P51S variant carriers develop caloric areflexia on VNG and vHIT vestibulo-ocular reflex (VOR)-gain dysfunction as defined by the Barany Society criteria for BVP. MATERIAL AND METHODS: One hundred eleven p.P51S variant carriers were included. The following vestibular function tests were applied in two different centers: ENG/VNG, vHIT, and VEMPs. The following parameters were analyzed: age (years), hearing loss (pure-tone average of 0.5-4 kHz [PTA0.5-4, dB HL]), sum of maximal peak slow-phase eye velocity obtained with bi-thermal (30°C and 44°C, water irrigation; 25°C and 44°C, air irrigation) caloric test (°/s), vHIT VOR-gain on LSCC, superior SCC and posterior SCC, C-VEMP both numerical (threshold, dB nHL) and categorical (present or absent), and O-VEMP as categorical (present or absent). The age of onset of vestibular dysfunction was determined both with categorical (onset in decades using Box & Whisker plots) and numeric approach (onset in years using regression analysis). The same method was applied for determining the age at which vestibular function declined beyond the limits of BVP, as defined by the Barany Society. RESULTS: With the categorical approach, otolith function was declining first (3rd decade), followed by caloric response (5th decade) and vHIT VOR-gains (5th-6th decade). Estimated age of onset showed that the deterioration began with C-VEMP activity (31 years), followed by caloric responses (water irrigation) (35 years) and ended with vHIT VOR-gains (48-57 years). Hearing deterioration started earlier than vestibular deterioration in female carriers, which is different from earlier reports. BVP was predicted at about 53 years of age on average with VNG caloric gain (water irrigation) and between 47 and 57 years of age for the three SCCs. Loss of C-VEMP response was estimated at about 46 years of age. CONCLUSION: Former hypothesis of vestibular decline preceding hearing deterioration by 9 years was confirmed by the numeric approach, but this was less obvious with the categorical approach. Wide confidence intervals of the regression models may explain deviation of the fits from true relationship. There is a typical vestibular deterioration hierarchy in p.P51S variant carriers. To further refine the present findings, a prospective longitudinal study of the auditory and vestibular phenotype may help to get even better insights in this matter.

Vestibular and oculomotor function in patients with vestibular migraine.

AIM: The purpose of this study was to assess the vestibular and oculomotor function in patients with vestibular migraine (VM). And we also investigate the relationship between testing results and effectiveness of preventive medications in VM. MATERIAL AND METHOD: 41 patients with VM were recruited in this study and examined with cervical and ocular vestibular evoked myogenic potential(cVEMP, oVEMP), video head impulse test(vHIT), caloric test and videonystagmography. All patients were treated with preventive medications. We calculated symptomatic improvement and record episodes frequency in patients with VM. Six months later, the effectiveness of preventive medications were evaluated and the relationship between vestibular testing and effectiveness of preventive medications were analyzed further. RESULTS: In vestibular function testing, 73% of patients with VM showed abnormal results. Abnormal cVEMP, oVEMP, vHIT, and caloric test were found in 20%, 44%, 32% and 56% respectively. The abnormal rate of oVEMP was significantly higher than that of cVEMP(p < 0.05). And the proportion of abnormal caloric test was obviously higher than that of vHIT (p < 0.05). In oculomotor function testing, 42% of the patients with VM showed pathological results which was significantly lower than that of vestibular function testing(p < 0.05). After 6 months follow-up, the proportion of prophylactic medication effectiveness was significantly higher in normal vestibular function testing group compared with the abnormal group (p < 0.05). CONCLUSION: Abnormal vestibular and oculomotor functions are commonly observed in patients with VM. And these patients with abnormal vestibular function possess a weak effectiveness of preventive medications.

Age adjusted normative data for Video Head Impulse Test in healthy subjects.

PURPOSE: This study aims to assess the effect of age in vestibulo-ocular reflex (VOR) gain measured by Video Head Impulse Test (VHIT) and to present normative data of VOR gain, median gain at 40, 60, 80 and 0-100 ms, and gain asymmetry according to decades of life in healthy subjects. MATERIAL AND METHODS: A total of 132 subjects with no previous history of vestibular disorders were enrolled to assess VOR gain by employing VHIT. The test was performed in the X-axis evaluating both horizontal semicircular canals (HSC). The same right-handed operator performed the test in all subjects. RESULTS: The mean VOR gain was higher in the right ear (0.99 ± 0.09) compared to the left ear (0.97 ± 0.08) (p = 0.001). Median gain at 60 ms was 0.92 ± 0.12 in the right HSC and 0.93 ± 0.10 for the left HSC, without significant difference (p = 0.94). A significant decrease of VOR gain occurred with increasing age in the right ear (r = -0.21, p = 0.01). Median gain at 60 ms decreased significantly as age increased in both HSC (right r = -0.17, p = 0.04; left r = -0.23, p = 0.006). No significant differences in VOR gain values were observed when the sample was stratified by age according to the analysis of variance. CONCLUSIONS: A slight but significant decrease in VOR function was observed as age increased for gain and median gain at 60 ms. Larger studies, including patients with central and peripheral vestibular disorders, are needed to assess the clinical implication of this effect when evaluating patients with vestibular disorders.

Alcohol binge-drinking damage on the vestibulo-oculomotor reflex.

PURPOSE: Binge drinking is associated with several adverse effects in multiple organs. This study aimed at evaluating the effects of a binge-like-drinking on the vestibulo-oculomotor reflex (VOR) using the video Head Impulse Test (vHIT) and the functional Head Impulse Test (fHIT). METHODS: Eleven healthy men (age range 32-35 years) with moderate drinking habits and no history of vestibular dysfunction were enrolled. A preliminary assessment of breath alcohol concentration (BrAC) to check for zero alcohol value and a pre-intake evaluation of VOR using the vHIT and the fHIT were carried on. Then, the subjects were asked to take drinks with different alcohol content (8-40% ethanol by volume) according to their choice, consuming at least 5 standard drinks. Volunteers stopped drinking after 3 h. After a further 30 min, post-intake BrAC measurements and VOR analysis were repeated. RESULTS: After alcohol intake, vHIT recorded an overall significant reduction of VOR gain (0.82 ± 0.07 on both sides) although the outcomes were below the normal range only in the four subjects with the highest blood alcohol levels. The post-intake fHIT outcomes were substandard in 9 participants, with a significant deterioration in performance (% of exact answers = 84.54 ± 11.05% on the left, 83.18 ± 14.53 on the right). CONCLUSIONS: Binge drinking severely affects VOR; fHIT seems more sensitive than vHIT in the assessment of VOR function for complex vestibular lesions, such as those determined by ethanol, suggesting that fHIT could support vHIT in vestibular dysfunction assessment.