Trunk Instability in the Pitch, Yaw, and Roll Planes during Clinical Balance Tests: Axis Differences and Correlations to vHIT Asymmetries Following Acute Unilateral Vestibular Loss.

BACKGROUND: Clinical dynamic posturography concentrates on the pitch and roll but not on the yaw plane instability measures. This emphasis may not represent the axis instability observed in clinical stance and gait tasks for patients with balance deficits in comparison to healthy control (HC) subjects, nor the expected instability based on correlations with vestibulo-ocular reflex (VOR) deficits. To examine the axis stability changes with vestibular loss, we measured trunk sway in all three directions (pitch, roll, and yaw) during the stance and gait tasks of patients with acute unilateral vestibular neuritis (aUVN) and compared the results with those of HC. Concurrent changes in VORs were also examined and correlated with trunk balance deficits. METHODS: The results of 11 patients (mean age of 61 years) recorded within 6 days of aUVN onset were compared within those of 8 age-matched healthy controls (HCs). All subjects performed a two-legged stance task-standing with eyes closed on foam (s2ecf), a semi-gait task-walking eight tandem steps (tan8), and four gait tasks-walking 3 m with head rotating laterally, pitching, or eyes closed (w3hr, w3hp, w3ec), and walking over four barriers 24 cm high, spaced 1 m apart (barr). The tasks' peak-to-peak yaw, pitch and roll angles, and angular velocities were measured with a gyroscope system (SwayStarTM) mounted at L1-3 and combined into three, axis-specific, balance control indexes (BCI), using angles (a) for the tandem gait and barriers task, and angular velocities (v) for all other tasks, as follows: axis BCI = (2 × 2ecf)v + 1.5 × (w3hr + w3hp + w3ec)v + (tan8 + 12 × barr)a. RESULTS: Yaw and pitch BCIs were significantly (p ≤ 0.004) greater (88 and 30%, respectively) than roll BCIs for aUVN patients. For HCs, only yaw but not pitch BCIs were greater (p = 0.002) than those of roll (72%). The order of BCI aUVN vs. HC differences was pitch, yaw, and roll at 55, 44, and 31%, respectively (p ≤ 0.002). This difference with respect to roll corresponded to the known greater yaw plane than roll plane asymmetry (40 vs. 22%) following aUVN based on VOR responses. However, the lower pitch plane asymmetry (3.5%) in VOR responses did not correspond with the pitch plane instability observed in the balance control tests. The increases in pitch plane instability in UVL subjects were, however, highly correlated with those of roll and yaw. CONCLUSIONS: These results indicate that greater yaw than pitch and roll trunk motion during clinical balance tasks is common for aUVN patients and HCs. However, aUVN leads to a larger increase in pitch than yaw plane instability and a smaller increase in roll plane instability. This difference with respect to roll corresponds to the known greater yaw plane than roll plane asymmetry (40 vs. 22%) following aUVN observed in VOR responses. However, the lower pitch plane asymmetry (3.5%) in VOR responses does not correspond with the enhanced movements in the pitch plane, observed in balance control tasks. Whether asymmetries in vestibular-evoked myogenic potentials (Vemps) are better correlated with the deficits in pitch plane balance control remains to be investigated. The current results provide a strong rationale for the clinical testing of directional specific balance responses, especially yaw and pitch, and the linking of balance results for yaw and roll to VOR asymmetries.

Customized Vestibular Rehabilitation for Vestibular Schwannoma Excision via Translabyrinthine Approach: A Single-Center Experience.

Objectives: To evaluate the effectiveness of intensive customized vestibular rehabilitation after vestibular schwannoma (VS) excision. Methods: 52 patients who underwent VS removal via a translabyrinthine approach from 2020 to 2022 were involved in this study. Bedside examination, video head impulse test (vHIT), functional head impulse test (fHIT), and the dizziness handicap inventory (DHI) were performed before and after the rehabilitation, which consisted of 10 sessions of specifically designed vestibular, visual, and physical integrated training. Results: After rehabilitation, the vHIT showed overall unchanged values on the affected and healthy side. In contrast, the scores of fHIT, which explores the higher connection of the vestibular system with visual and cerebellar pathways, improved on both the pathological and healthy sides after training (p-value 0.004 and 0.000, respectively). The effectiveness of the rehabilitation was reinforced by the DHI scores, which were considerably lower after training. Conclusions: To our knowledge, this is the first study to explore fHIT outcomes after removal of VS, estimating the impact of rehabilitation on the overall compensation process. The outcomes support the role of extensive postsurgical rehabilitation in the compensatory process, even just a few days after surgery.

Impact of audiovestibular factors on prognosis in patients with sudden sensorineural hearing loss without vertigo.

PURPOSE: This study aimed to investigate the hearing outcomes in patients with sudden sensorineural hearing loss without vertigo (SSNHLwoV). METHODS: Patients with SSNHLwoV managed from December 2016 to March 2020 were prospectively enrolled in an academic tertiary referral center. Fifty-one patients with SSNHLwoV who completed high-dose steroid treatment. The hearing prognosis was analyzed using a multivariate Cox regression model. RESULTS: The rates of complete, partial, and no hearing recovery were 52.9%, 17.6%, and 29.4% in patients with SSNHLwoV, respectively. The video head impulse test (vHIT) of the posterior semicircular canal (PSC), high-tone hearing loss (4-8 kHz) ≥ 30 dB, and average hearing threshold (0.5-1-2-4 kHz) were significantly associated with incomplete recovery of hearing after treatment. In multivariate analysis, the vHIT of the PSC (hazard ratio [HR], 14.502; 95% confidence interval [CI], 1.371-153.355) and high-tone hearing loss ≥ 30 dB (HR, 9.170; 95% CI, 2.283-36.830) remained robust. CONCLUSIONS: Abnormal vestibular function tests were performed in 80.4% of the patients with SSNHLwoV. Abnormal vHIT of the PSC and high-tone hearing loss ≥ 30 dB were independent factors resulting in incomplete recovery of hearing in patients with SSNHLwoV. In the SSNHLwoV cohort, the caloric test was not significantly associated with hearing prognosis, and vHIT was a feasible predictor of treatment outcome.

[Correlation between parameters of suppression head impulse paradigm and changesin DHI score in acute vestibular neuritis].

Objective:To explore the correlation between the parameters of suppression head impulse paradigm（SHIMP） and changes in dizziness handicap inventory（DHI） scores. Additionally, to evaluate the degree of vertigo and prognosis of patients with acute vestibular neuritis through SHIMP parameters. Methods:Thirty-three patients with acute vestibular neuritis were enrolled for DHI evaluation, vHIT and SHIMP. A secondary DHI score were evaluated after after two weeks, once patients no longer exhibited spontaneous nystagmus. The decrease in the second DHI score was used as the efficacy index（EI）. All patients were divided into significantly effective group, effective group and ineffective group based on EI. Differences of the VOR gain values of SHIMP and the anti-compensatory saccade were compared among the three groups. Results:There were 13 cases in the significant effective group, 11 cases in the effective group, and 9 cases in the ineffective group. ①The mean gain of the horizontal semicircular canal in the significant effective group, the effective group, and the ineffective group was（0.50±0.11）, （0.44±0.12）, and（0.34±0.08）, respectively. The difference between the significant effective group and the ineffective group was statistically significant（P<0.01）. The gain of horizontal semicircular canal was positively correlated with EI（r=0.538 5, P<0.01） 。②The occurrence rate of the anti-compensatory saccade in the significant effective group, the effective group, and the ineffective group was（51.23±19.59）, （33.64±17.68）, and（13.78±11.81）, respectively. Pairwise comparisons between each group showed statistical significance（P<0.05）. The occurrence rate of anti-compensatory saccade was positively correlated with EI（r=0.658 2, P<0.01）. Conclusion:The horizontal semicircular canal gain and the occurrence rate of the anti-compensatory saccade in SHIMP for patients with acute vestibular neuritis were closely correlated with decrease in DHI score.

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.

Clinical Utility of Remote Camera Video Head Impulse Testing Children Less Than 3 Years.

The purpose of this case report is to highlight both the feasibility and clinical utility of remote camera video head impulse testing (vHIT) in children <3 years. Five cases are described where remote camera vHIT was used to quantify ear specific semicircular function in children at risk for vestibular dysfunction. Remote camera vHIT is a helpful clinical tool for quantifying ear specific semicircular function in children between 6 and 31 months. Remote camera vHIT is feasible and provides ear specific information regarding semicircular canal function, which can be used to augment or validate the presence of vestibular dysfunction in children <3 years. Laryngoscope, 2024.

Vestibular evaluation with video head impulse test in pediatric cochlear implant patients.

BACKGROUND: The cochlear implant (CI) is effective for rehabilitating patients with severe to profound sensorineural hearing loss. However, its placement and use have been associated with various complications, such as those affecting the vestibular system. The objective of this study was to compare vestibular function using the video head impulse test (vHIT) in pediatric patients before and after CI placement. METHODS: A descriptive and retrospective study was conducted. The outcomes of 11 pediatric patients of both sexes with a history of profound hearing loss were evaluated. The results of vestibular-ocular reflex (VOR) gain, saccades, asymmetry, Pérez Rey (PR) index, and VOR/saccade ratio for both ears obtained by the vHIT test before and after CI placement were compared. RESULTS: Of the 11 patients evaluated, the VOR gain showed that 81.8% had normal function, 18.2% had hypofunction, and no patients had hyperfunction before implantation. No statistically significant differences were found when compared with post-implant off and post-implant on conditions (p > 0.05). The extracted variables, asymmetry, PR index, and the VOR/saccades ratio also showed no statistically significant differences between the pre- and post-implant conditions, whether off or on. CONCLUSIONS: The vestibular function of pediatric patients did not show significant changes before and after CI placement. The vHIT test is a valuable tool for assessing vestibular function and could be considered a criterion for surgical and rehabilitation decisions in patients undergoing CI placement.

INTRODUCCIÓN: El implante coclear es un dispositivo eficaz para la rehabilitación de pacientes con hipoacusia neurosensorial severa a profunda. Sin embargo, su colocación y uso se ha asociado a diversas complicaciones, entre ellas a nivel del sistema vestibular. El objetivo del presente estudio fue comparar la función vestibular mediante la prueba de videoimpulso cefálico (vHIT) de pacientes pediátricos antes y después de la colocación del implante coclear. MÉTODOS: Se llevó a cabo un estudio descriptivo y retrospectivo. Se evaluaron los resultados de 11 pacientes pediátricos de ambos sexos con antecedente de hipoacusia profunda. Se compararon los resultados de ganancia del VOR, sacadas, asimetría, índice PR así como la relación VOR/sacadas para ambos oídos obtenidos mediante la prueba vHIT antes y después de la colocación del implante coclear. RESULTADOS: De los 11 pacientes evaluados, la ganancia del VOR mostró que el 81.8% tenía normofunción, 18.2% hipofunción y ningún paciente hiperfunción antes del implante. Al compararlo con la ganancia post implante apagado y post implante encendido no se encontraron diferencias estadísticamente significativas (p > 0.05). Las variables sacadas, asimetría, índice PR así como la relación VOR/sacadas tampoco mostraron diferencias estadísticamente significativas entre las condiciones pre y pos implante ya sea apagado o encendido. CONCLUSIONES: La función vestibular de pacientes pediátricos no mostró cambios significativos previo y posterior a la colocación del implante coclear. La prueba vHIT es una herramienta útil que permite evaluar la función vestibular y que podría considerarse como criterio para tomar decisiones quirúrgicas en pacientes que se encuentran en protocolo para implante coclear.

High-Frequency Vestibular Function Is Vulnerable to Presbyvestibulopathy.

INTRODUCTION: In 2019, mild vestibular function deficiency in elder populations was defined as presbyvestibulopathy (PVP) by the Classification Committee of the Bárány Society. The diagnostic criteria include tests for low-, mid-, and high-frequency vestibular function, represented by caloric testing, rotary chair testing, and head impulse testing, respectively. However, there is still a lack of large-scale reports supporting the relationship between vestibular function tests (VFTs) and aging. In this study, we evaluated whether each test is correlated with aging in the elderly population aged over 50. METHODS: This study retrospectively enrolled 1043 subjects from a single university hospital database after excluding those with unilateral and bilateral vestibulopathy, central dizziness, and acute dizziness. Enrolled subjects had caloric canal paresis <20%, vHIT lateral canal gain >0.6, vHIT interaural difference <0.3, and age >50 years old. RESULTS: Significant negative correlations with age were identified in the vHIT (p < 0.001) and rotary chair test (RCT) 1.0 Hz gain (p = 0.030). However, the caloric test (p = 0.739 and 0.745 on the left and right sides, respectively) and RCT 0.12 Hz gain (p = 0.298) did not show a significant correlation with age. A total of 4.83% of subjects aged 70 years or older showed sub-normal vHIT gain that met the criteria of PVP, whereas only 0.50% of subjects aged 60 to 69 did. The prevalence of sub-normal caloric test results, however, was not significantly different between the two age groups (21.55% in the 60-69 age group and 26.59% in the >70 age group). CONCLUSIONS: The high-frequency range vestibular function seems vulnerable to aging, and this is more discernible at age >70 years. The weak correlation between age and low-frequency vestibular function tests, such as the caloric test and low-frequency rotary chair testing, suggests the need to revisit the diagnostic criteria for PVP.

Relationship Between Motion Sickness Susceptibility and Vestibular Test Results.

Objective: There is no test parameter with high sensitivity and specificity for the diagnosis of motion sickness. The aim of this study was to demonstrate a correlation between vestibular function tests and motion sickness. In addition, our secondary aim is to evaluate the sensitivity of the skull vibration-induced nystagmus test (SVINT) in the diagnosis of motion sickness. Methods: A total of 44 young adults aged 19-25 who had no hearing loss, complaints of dizziness/vertigo, or any diagnosed neurological disease were included. According to the motion sickness susceptibility questionnaire-short form (MSSQ-SF), participants were divided into the motion sickness group (21±1.38 years) and control group (20.5±1.18 years). Mean MSSQ-SF score for the motion sickness group is 78.18±12.2 and for control group 19.09±17.08. Ocular and cervical vestibular evoked myogenic potential tests, SVINT, video head impulse test, and oculomotor tests were performed. Results: The only significant difference between the groups was in n1-p1 amplitudes in the left ocular vestibular evoked myogenic potential test (p=0.014). None of the other parameters differed between the two groups (p>0.05). Conclusions: There was no significant relationship between motion sickness susceptibility and the results of any vestibular function test. Performing diagnostic tests for motion sickness in an environment that creates significant sensory conflict may yield different results. This study contributes to the literature in terms of evaluating the vestibular system using a comprehensive test battery and is the first to use the SVINT test in motion sickness.

Nationwide Prevalence of Video Head Impulse Test Abnormality and its Risk Factors in South Korea.

OBJECTIVE: To identify the prevalence of and relevant information for video head impulse test (vHIT) abnormality in a large population. STUDY DESIGN: A cross-sectional design. SETTING: Korean National Health and Nutrition Examination Survey, 2021. METHODS: The sample was representative of the Korean population, with 2237 participants aged ≥40 years. A vHIT was performed to evaluate vestibular function. The vestibulo-ocular reflex (VOR) gain and the presence of reproducible catch-up saccades was assessed in a vHIT. Participants also completed questionnaires for demographics, socioeconomic status, and basic information regarding systemic diseases and dizziness and underwent hearing tests with automated pure-tone audiometry. RESULTS: The prevalence of vHIT abnormality was 22.5%, with unilateral (14.3%) being more common than bilateral (8.2%). The prevalence of vHIT abnormality increased significantly with age, with the highest rate observed in individuals aged >70 years (42.5%). Both hearing and VOR gain deteriorated with age, but the patterns of age-related progression were different. While hearing loss (HL) deteriorated gradually and progressively throughout adulthood, VOR gain deterioration was markedly evident after 70 years of age. CONCLUSION: Considering the high prevalence of vHIT abnormality, appropriate social and medical policies are needed to prevent associated injuries and improve patients' quality of life. The distinct age-related changes in HL and objective findings of vestibular dysfunction indicate the need for different approaches to address these social problems in aging countries.

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.

Comparing Video Head Impulse Testing With Rotary Chair in Pediatric Patients: A Controlled Trial.

OBJECTIVES: To investigate the efficacy of video head impulse testing (VHIT) in detecting vestibular loss in pediatric patients with abnormal rotary chair testing, compared to a control group with normal rotary chair testing. STUDY DESIGN: Prospective, nonrandomized, controlled trial. SETTING: Pediatric vestibular program at tertiary level children's hospital. METHODS: Patients 3 to 18 years of age were recruited to undergo VHIT and rotary chair testing between September 2015 and November 2022. VHIT results were compared between an experimental group of 23 patients with vestibular symptoms and abnormal rotary chair testing results versus a control group of 14 patients without vestibular symptoms and with normal rotary chair testing results. RESULTS: The experimental group demonstrated reduced mean VHIT gain for the lateral semicircular canals (right = 0.83; left = 0.75) relative to the control group (right = 1.04, P = .005; left = 0.98, P < .001), but there was no significant difference between groups in superior and posterior canal responses. Among controls, there were no significant differences in mean gain values for each canal plane between age groups (3-7, 8-12, and 13-18 years) or between genders. A VHIT lateral canal gain value <0.85 and/or corrective saccades demonstrated 100% specificity and 100% positive predictive value for detecting vestibular loss on rotary chair, but only 69.6% sensitivity and 66.7% negative predictive value. CONCLUSION: VHIT is a useful test for detecting impairment of the lateral semicircular canals in children, though its sensitivity is limited relative to rotary chair. Its role in detecting vertical canal dysfunction in pediatric patients may be more limited and warrants further study.

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.

Vestibulo-Ocular Reflex in the Aging Population.

Objectives: The aim of this study was to evaluate vestibulo-ocular reflex (VOR) of individuals over 60 years of age who have not been diagnosed with a specific vestibular pathology. Methods: Bilateral six-semicircular canal video head impulse test (vHIT), Dizziness Handicap Inventory and European Evaluation of Vertigo scales were applied to participants. Results: In total, 103 participants were included in the study (75 male, 28 female), and the mean age was 69.35 ± 7.41 years. The mean age of 7th decade group was 64.32±3.12 (59 participants; 38 male, 21 female), and the mean age of 8th decade and older group was 76.11±5.93 (44 participants; 37 male, 7 female). No significant differences were found between the VOR gains of the lateral or vertical semicircular canals between the 7th decade and 8th decade and older groups (p>0.05). In the 8th decade and older group, the presence of right lateral semicircular canal corrective saccade and left posterior semicircular canal corrective saccade showed a positively moderate correlation with VOR gains of the same semicircular canals (r=0.455, p=0.002, and r=0.518, p=0.001, respectively). No significant correlation was found between age and VOR gain in the 7th decade group, however, there was a negatively weak correlation between age and left lateral semicircular canal VOR gain (r=-0.366, p=0.017) in the 8th decade and older group. Conclusion: While assessing the age-related changes in VOR using vHIT, it must be considered that the changes related to aging of the vestibular system begin to emerge in the population over 70 years of age, and corrective saccade findings may be more informative than VOR gains in revealing these changes.

Video head impulse test in subacute and chronic stroke survivors: new perspectives for implementation of assessment in rehabilitation.

INTRODUCTION: The Video Head Impulse Test (vHIT) is a safe and reliable assessment of peripheral vestibular function. Many studies tested its accuracy in clinical settings for differential diagnosis and quantification of the vestibulo-oculomotor reflex (VOR) in various disorders. However, the results of its application after lesions of the CNS are discordant and have never been studied in rehabilitation. This study aims to assess the VOR performance in a sample of stroke survivors. METHODS: This is a cross-sectional study on 36 subacute and chronic stroke survivors; only persons with first-ever stroke and able to walk independently, even with supervision, were included. We performed VOR assessments for each semicircular canal by vHIT and balance assessments by the Berg Balance Scale and the MiniBESTest scale. RESULTS: Two hundred and sixteen semicircular canals were assessed using the Head Impulse paradigm (in both the vertical and horizontal planes), while 72 semicircular canals were assessed using the Suppressed Head Impulse paradigm (horizontal plane). There was a high prevalence of participants with dysfunctional canals, particularly for the left anterior and right posterior canals, which were each prevalent in more than one-third of our sample. Furthermore, 16 persons showed an isolated canal dysfunction. The mean VOR gain for the vertical canals had confidence intervals out of the normal values (0.74-0.91 right anterior; 0.74-0.82 right posterior; 0.73-0.87 left anterior). CONCLUSION: Our findings suggest that peripheral vestibular function may be impaired in people with stroke; a systematic assessment in a rehabilitation setting could allow a more personalized and patient-centred approach.

[Investigation of vestibular function in patients with vestibular neuritis]. / Issledovanie vestibulyarnoi funktsii u patsientov s vestibulyarnym neironitom.

Vestibular neuritis occupies the third place in terms of prevalence in the structure of peripheral vestibulopathies, therefore, the choice of optimal diagnostic and differential diagnostic tactics at different stages of the disease is an urgent task. OBJECTIVE: To optimize the diagnostic algorithm for vestibular neuritis based on an assessment of the sensitivity of clinical methods for studying vestibular function in the recovery period of the disease. MATERIAL AND METHODS: A comprehensive assessment of the sensitivity of clinical methods for the study of vestibular function in the acute (up to 14 days: at the time of initial treatment, on the 7th and 14th day) and subacute (up to 3 months: on the 28th and 90th day) periods of the disease in 52 patients with upper vestibular neuritis was carried out. RESULTS: The timing of the processes of restoration of vestibular function after a transferred vestibular neuritis is individual: after 14 days, restoration of vestibular function was recorded in 52% (n=27) patients, after 1 month - in 62% (n=32), after 3 months - in 71% (n=37) patients with upper vestibular neuritis. Statocoordination, statokinetic, oculomotor tests under visual control have the highest sensitivity in the acute period of vestibular neuritis, within up to 7 days from the onset of symptoms. In the subacute period of vestibular neuritis, the study of spontaneous nystagmus and nystagmus in the head shaking test retains high sensitivity only when using special tools (Frenzel goggles or videonystagmography). A decrease in the sensitivity of the head rotation test and the dynamic visual acuity test in the subacute period of vestibular neuritis is associated with the processes of central compensation and the formation of a latent saccade. CONCLUSION: The sensitivity of clinical tests in patients with vestibular neuritis depends on the timing of the examination.

Vertical saccades during horizontal head impulses: a sign of posterior semicircular canal hypofunction.

Objective: We describe an uncharacteristic vestibular-ocular reflex (VOR) pattern, studied by video head impulse tests (VHIT) in patients suffering from unilateral isolated posterior semicircular canal (PSC) hypofunction. In these patients, we found an upward sliding of the eyes, followed by an oblique downward catch-up saccade during horizontal head impulse to the healthy side. Methods: We present a retrospective study of all VHIT exams presenting isolated PSC hypofunction between May 2020 and November 2022. Results: We found 37 patients, which led to the discovery of such incongruent eye movement in 19 cases; their gain data are shown and compared to the remaining 18 cases in which such an anomaly was absent. A control group of 31 healthy subjects was recruited to define the reference criteria for VHIT gain values. The correlation between the amplitude of the vertical saccade and the relative functional imbalance of the vertical semicircular canals was studied. Conclusions: We have observed that in approximately half of the subjects with isolated CSP deficiency, there is a VOR anomaly. A possible pathophysiological explanation of the unbalanced effect of vertical semicircular canal stimulation of a labyrinth during horizontal head thrust toward the opposite side is proposed. The planar incongruity of the response of the VOR described here appears more evident at the onset of the CSP deficit. Current VHIT systems do not detect this incongruent eye reflex. They can lead to an error in gain evaluation (pseudo-deficit) of the lateral semicircular canal of the healthy side and problems in performing the test (trace rejected). In the future, software for VHIT should take into account the possibility of non-coplanar ocular responses to cephalic stimuli.

Posterior Semicircular Canal Dehiscence with Vestibulo-Ocular Reflex Reduction for the Affected Canal at the Video-Head Impulse Test: Considerations to Pathomechanisms.

Posterior semicircular canal dehiscence (PSCD) has been demonstrated to result in a third mobile window mechanism (TMWM) in the inner ear similar to superior semicircular canal dehiscence (SSCD). Typical clinical and instrumental features of TMWM, including low-frequency conductive hearing loss (CHL), autophony, pulsatile tinnitus, sound/pressure-induced vertigo and enhanced vestibular-evoked myogenic potentials, have been widely described in cases with PSCD. Nevertheless, video-head impulse test (vHIT) results have been poorly investigated. Here, we present six patients with PSCD presenting with a clinical scenario consistent with a TMWM and an impaired vestibulo-ocular reflex (VOR) for the affected canal on vHIT. In two cases, an additional dehiscence between the facial nerve and the horizontal semicircular canal (HSC) was detected, leading to a concurrent VOR impairment for the HSC. While in SSCD, a VOR gain reduction could be ascribed to a spontaneous "auto-plugging" process due to a dural prolapse into the canal, the same pathomechanism is difficult to conceive in PSCD due to a different anatomical position, making a dural herniation less likely. Alternative putative pathomechanisms are discussed, including an endolymphatic flow dissipation during head impulses as already hypothesized in SSCD. The association of symptoms/signs consistent with TMWM and a reduced VOR gain for the posterior canal might address the diagnosis toward PSCD.

Suppression head impulse test in children-experiences in a tertiary paediatric vestibular centre.

The suppression head impulse paradigm (SHIMP) involves suppression of the vestibulo-ocular reflex (VOR) and anticompensatory saccades generated thereof. SHIMP is gaining importance to understand vestibular compensation with its different parameters (VOR gain/peak saccadic velocity PSV/latency of saccades). SHIMP studies are emerging in adults, but pediatric studies have hardly been performed. This study is a retrospective case note audit over a period of 2 months in a tertiary pediatric vestibular center in the United Kingdom to investigate whether SHIMP is safe/robust to be used in children conforming to existing standards/norms in normal children and whether it yields any meaningful inferences in pediatric vestibular hypofunction. This is the largest pediatric SHIMP study to date. A total of 44 referred children (6-18 years, female children>male children) with a range of complaints from dizziness, imbalance, motor incoordination, postural instability, and hearing loss were included, and their SHIMP parameters were measured. All children underwent comprehensive functional/objective audiovestibular assessments. Two groups were defined-Group A with normal vestibular function and Group B with abnormal vestibular function. The normal population showed an average SHIMP VOR gain of 0.98+/-0.08 and latency of overt saccades at 215.68+/-46.16 milliseconds agreeing with published evidence. The PSV of overt saccades was 315.39+/-56.30/s, and there was a gain asymmetry of 7.42+/-4.68 between the sides. Statistically significant differences with moderate/large effect sizes were observed between the groups in terms of VOR gain and PSV but not in saccade latencies. Covert saccades were rare in SHIMP, while overt saccades were observed in 100% of children. VOR gain difference between the head impulse paradigm (HIMP) and the SHIMP was significant as well. We observed statistically significant differences in side asymmetry of VOR gain between the groups. Furthermore, we identified a group of children with cerebellar lesions where overt saccades in SHIMP were rather low in number. Further research is recommended to investigate pediatric PSV, asymmetry, and inability to generate overt saccades that may suggest useful means to assess compensation and central function. We conclude that SHIMP yields valuable information and is a safe, easy to perform, and a reliable test that should be used in children to supplement HIMP.

Presence of Spontaneous Nystagmus, Benign Paroxysmal Positional Vertigo, and Tumarkin Fall in Patients With Primary Headache and Their Responses to Caloric and Video Head Impulse Tests.

Background: Migraine, vestibular migraine (VM) and tension-type headache (TTH) are the most common disorders in dizziness and headache clinics, associated with dizziness or vertigo and postural imbalance, causing a substantial burden on the individual and the society. The objective of this research was to examine the presence of spontaneous nystagmus, comorbidity of benign paroxysmal positional vertigo (BPPV), and Tumarkin fall in patients; additionally, the study focused on assessing the patients' responses to bithermal caloric irrigation and video head impulse test (vHIT). Methods: Consecutive patients diagnosed with migraine, VM, and TTH according to the International Classification of Headache Disorders, third edition (beta version (ICHD-3ß)), who were referred to Dizziness and Headache Clinic were enrolled. BPPV and Tumarkin fall were assessed by questionnaires. The presence of BPPV was further evaluated through Dix-Hallpike or head roll maneuver, while spontaneous nystagmus was monitored using video-oculography during interictal period. Lastly, patients' responses to bithermal caloric irrigation and vHIT were analyzed. Results: There was a significantly higher incidence of spontaneous nystagmus in VM compared to both migraine and TTH. The drop attack episodes were slightly more frequent in VM than in TTH and migraine, though not statistically significant. The prevalence of BPPV was significantly higher in VM than in migraine and TTH. Unilateral vestibular paresis was more common in the VM group than in migraine and TTH. There was profound unilateral weakness (UW) in VM patients than in migraine, but no significant difference was found between VM and TTH. In VM, the percentage of saccades along with reduced vHIT gain was significantly higher than in migraine. Lastly, the percentage of abnormal response in vHIT was significantly lower than the percentage of abnormal UW in caloric irrigation across all groups. Conclusions: In VM patients, the prevalences of decompensated peripheral damage and BPPV were higher than in migraine and TTH patients as disclosed by the presence of peripheral spontaneous nystagmus and abnormal vHIT during the interictal period. Our findings suggest that the peripheral vestibular system acts as a significant mechanism in the pathogenesis of VM, and it might also be involved in migraine and TTH cases without vertigo symptoms.