Head Impulse Research Articles

Comparative analysis of audiovestibular testing results in vestibular schwannomas

Objective:This study aimed to analyze the results of auditory and vestibular function tests in patients with unilateral vestibular schwannoma and explore their association with tumor size. Methods:Clinical data from 81 patients diagnosed with unilateral vestibular schwannoma who underwent pure-tone audiometry（PTA）, cervical and ocular vestibular evoked myogenic potentials（c/oVEMP）, as well as video head impulse test（vHIT）, and subsequently underwent surgical treatment, were retrospectively analyzed. Patients were categorized into groups based on tumor size: small （≤ 15 mm）, medium（16-30 mm）, and large （>30 mm）, determined by the maximum tumor diameter on contrast-enhanced MRI scans. Results:PTA results indicated hearing loss in 73 cases（90.1%）; vestibular function tests revealed abnormal rates for the anterior semicircular canal, horizontal semicircular canal, posterior semicircular canal, utricle, and saccule at 29.6%, 77.8%, 54.3%, 90.1%, and 92.6%, respectively. Statistically, no significant differences were found in preoperative hearing test results among patients in different groups（F=0.393, P=0.676）. However, significant differences were observed in horizontal semicircular canal gain（r=-0.248, P=0.025）, abnormal rates of horizontal semicircular canal catch-up saccades（r=0.507, P<0.001）, as well as cVEMP（χ²=15.111, P=0.004） and oVEMP thresholds（χ²=18.948, P<0.001） across varying tumor size groups. Conclusion:The extent of hearing loss in patients with vestibular schwannoma is not correlated with tumor size, whereas the degree of vestibular dysfunction demonstrates a correlation with tumor size.

Effect and differentiation of spontaneous nystagmus of acute unilateral vestibulopathy on saccade in the video head impulse test

Objective:Exploring the performance characteristics of spontaneous nystagmus（SN） in video-head impulse test（vHIT） and its possible effects on saccade. Methods:Vestibular function tests such as vHIT and SN were conducted in 48 patients with acute unilateral vestibulopathy（AUVP）. The saccade characteristics of vHIT in patients without SN and those with SN were analyzed, as well as the expression characteristics of SN in vHIT. Results:Among the 48 AUVP patients, there were 34 cases with SN, including 31 cases with saccade on the healthy side, 11 cases with both the same and opposite directions of eye movement, 19 with the opposite only, 1 with same direction only, and 3 cases without saccade. There were 14 patients without SN, of whom 10 showed saccade on the healthy side, including 4 with both eye movements in the same and opposite direction, 2 in the opposite direction only, 4 in the same direction only, and 4 without saccade. There is a correlation between reverse saccade on the healthy side and the presence of SN in patients. SN in vHIT can appear opposite to the direction of eye movement on the healthy side, while on the affected side it can appear the same as the direction of eye movement and may cause more discrete overt saccade. 32 patients in the acute phase（≤2 w）, 29 patients with SN, SN intensity of（6.7 ± 3.2） °/s, and 3 patients without SN. 16 cases in non acute phase（>2 w）, 5 cases with SN, SN intensity of（3.7 ± 2.1） °/s, and 11 cases without SN. In the acute phase there were 30 cases of saccade on the healthy side, 10 cases with both the same and opposite direction of eye movement, 18 cases with only the opposite direction, 2 cases with only the same direction and 2 cases without saccade. There is a correlation between the duration of the disease and the occurrence of reverse saccade on the healthy side. The intensity cut off point of SN for reverse saccade is 2.1 °/s in the healthy lateral semicircular canal vHIT. Conclusion:Compensatory saccades and SN waves with similar waveforms are mostly present in vHIT in AUVP patients. SN wave is in the opposite direction of the normal side and eye movement wave, and the affected side and dominant saccade direction are in the same direction and mixed together, which can affect the dispersion and amplitude of overt saccade in vHIT. Accurate identification of SN in vHIT of AUVP patients is not only the key factor to identify compensatory saccade, but also can provide help for the diagnosis and compensatory assessment of AUVP.

Superior semicircular canal dehiscence isolation by transmastoid two-point canal plugging with preservation of the vestibulo-ocular reflex. German version

This article describes the surgical treatment of superior semicircular canal dehiscence syndrome (SCDS) by isolating the dehiscence using transmastoid two-point canal plugging while preserving the high-frequency vestibulo-ocular reflex (VOR) of the affected semicircular canal. The superior semicircular canal is opened via atransmastoid approach anterior (as far from the ampulla as possible) and posterior to the dehiscence and then plugged with connective tissue and bone dust. In two clinical exemplary cases, vestibular testing showed that the VOR measured by video head impulse (vHIT) test was preserved (patient1: gain preoperative 0.7, long-term postoperative 0.75; patient2: gain preoperative 0.64, long-term postoperative 0.79; reduction of corrective saccades in each case) with asimultaneous reduction in pathologically increased amplitudes of vestibular evoked myogenic potentials (VEMPs) and asignificant improvement in clinical symptoms with almost complete freedom from symptoms. One possible explanation for preservation of the high-frequency VOR of the superior semicircular canal would be the deformability of the endolymphatic space described at high stimulation frequencies, which can lead to endolymph movements in the area of the ampulla with deflection of the cupula despite blockage of the semicircular canal.

Video head impulse test (vHIT) unravels the hidden pathology in chronic vestibular deficit

BackgroundThe caloric test is persistently altered in chronic peripheral vestibular hypofunction (PVH). So, we cannot depend on it to measure the degree of compensation in chronic vestibulopathy patients who are still complaining. So our aim was to assess the utility of vHIT to discover the unrevealed pathology in those patients. Our study included 20 subjects with unilateral chronic PVH who were still complaining (study group) and 20 healthy volunteers (control group). Videonystagmography (VNG) and video head impulse test (vHIT) were applied to all the subjects.ResultsVNG and caloric test results showed compensation signs in the study group. The caloric test indicated unilateral weakness in the affected side. According to vHIT results, a comparison between the affected lateral canal, contralateral healthy lateral canal among the study group, Rt. lateral canal, and Lt. lateral canal among the control group revealed no significant difference (P = 0.789), while comparing anterior and posterior canals showed significant differences (P = 0.005, 0.025) respectively.ConclusionThe caloric test assesses only the horizontal semicircular canal and it is persistently altered in unilateral chronic PVH. So, we cannot depend on it to measure the degree of compensation in chronic vestibulopathy patients who are still complaining nor to detect unrevealed pathology regarding ant or post semi-circular canal. So we can use the vHIT test to discover the unrevealed pathology in those patients.

Unilateral Vestibular Hypofunction in an Adolescent: Case Report and Literature Review

Objective − The report presents a case of an adolescent girl with vertigo resulting from unilateral vestibular hypofunction, diagnosed after extensive pediatric and otorhinolaryngological evaluations.Case Report − A seventeen-year-old female adolescent sought medical assistance at the pediatric emergency hospital service on several occasions within one year due to feelings of weakness and darkened vision occurring during abrupt standing, exposure to heat, and stress. Symptoms were initially attributed to school obligations, low blood pressure, and the menstrual cycle. After an episode that also involved a brief loss of consciousness, an extensive neurological evaluation was conducted, excluding epileptogenic causes. Subsequent diagnostic procedures included evoked visual potential tests, psychological assessments, laboratory blood tests, thyroid hormone assays, and Borrelia burgdorferi serology, all yielding normal results. Finally, otorhinolaryngological examinations were performed, including pure tone audiometry, tympanometry, video head impulse tests, videonystagmography, and vestibular evoked myogenic potential tests. These tests indicated symptoms arising from unilateral labyrinthine hypofunction of the inner ear. The patient underwent vestibular rehabilitation, resulting in symptom resolution and confirmed functional recovery.Conclusion − Diagnosing vertigo in adolescence is challenging, as impaired balance can manifest as a symptom of various diseases. Presentation with atypical symptoms for peripherally caused balance disorders complicates diagnosis. Otorhinolaryngologists and audio-vestibular diagnosticians play pivotal roles in establishing accurate diagnoses.

Revisiting Diagnostic Criteria for Bilateral Vestibulopathy: A New Comprehensive Instrumental Model.

Background: Bilateral vestibulopathy (BVP) is a disabling condition characterized by a deficit in vestibular function on both sides. Current diagnostic criteria consider instrumental data only from horizontal canals, excluding vertical canals and otolithic function, with the possibility of not including some variants of BVP. This study aims to evaluate vestibular functions in people with chronic vestibular syndrome through a comprehensive battery of tests. Methods: This diagnostic accuracy study included patients who met criteria for probable BVP. The index test included a thorough evaluation of the vestibular system, using the video Head Impulse Test (vHIT) to measure the gain of the angular vestibulo-ocular reflex (aVOR) in all six semicircular canals and the cervical and ocular vestibular-evoked myogenic potentials (VEMPs) to assess otolith function. The diagnostic criteria established by the Barany Society were considered the standard reference, including only the horizontal vHIT as an instrumental assessment. Results: 78 patients (41 male, age 61.40 ± 12.99) were enrolled. The Barany criteria showed a low ability to rule out BPV (sensitivity = 46%). The median Dizziness Handicap Inventory (DHI) varied from 66 to 69 among the models studied, and a significant difference in DHI scores between positive and negative tests was observed for the Barany criteria and the six-canals vHIT model. Conclusions: Our findings highlight the potential to transform BPV diagnostic criteria. The identification of new bilateral vestibular dysfunction variants through improved diagnostic tools calls for revising current criteria, with promising implications for patient care and understanding of etiological and prognostic aspects.

Normal Variations of Video Head Impulse Test in Adult Populations at Peak Head Velocity of Below 150 Degrees/Second

Normal Variations of Video Head Impulse Test in Adult Populations at Peak Head Velocity of Below 150 Degrees/Second

Subjective spatial orientation discomfort is associated with decreased real-world spatial performance and lower cognitive function.

Spatial memory and orientation deficits often precede cognitive impairment in incipient dementia, e.g., Alzheimer's disease. Therefore, early diagnosis of spatial impairment may be crucial to the initiation of an adequate therapeutic intervention. Subjective tests, such as spatial anxiety and spatial discomfort questionnaires, and objective tests in the form of quantitative measures of orientation, are available. In these tests, vestibular hypofunction has often been neglected as a potential confounder. The major research question in this study was how self-assessed questionnaires correlate with the data from objective measures in participants with proven normal vestibular function. A heterogeneous group of 135 participants (72 females, 63 males, mean age 62.75 ± 14.46 years) from a tertiary center for vertigo and balance disorders consisting of two cohorts, with (n = 49) and without (n = 86) cognitive deficits in a screening test (MoCA), was examined (a) with a newly introduced inventory for subjective spatial discomfort (Extended Inventory for Spatial Orientation Discomfort, EISOD), (b) a well-established questionnaire for subjective spatial skills (Santa Barbara Sense of Direction Scale, SBSODS), and (c) the objective three-dimensional real-world pointing task (3D-RWPT) before and after horizontal body rotations. In all patients, acute central or peripheral vestibular deficits were ruled out by neuro-orthoptics, bithermal water calorics and video head impulse testing. Self-assessed spatial orientation discomfort (EISOD) correlated with the amount of spatial impairment in the 3D-RWPT for both cohorts. The cognitively impaired patients showed significantly higher levels of spatial discomfort (i.e., lower scores; Welch's t-test t-2.58, p < 0.01, Cohen's d - 0.46), and higher angular deviations in the (cognitively demanding) transformation paradigm of the 3D-RWPT (t 2.37, p 0.02, Cohen's d 0.44). They preferred retinotopic/egocentric spatial encoding strategies in the pointing task (Welch's t-test t-2.61, p < 0.01, Cohen's d - 0.47). In contrast, the self-report of spatial abilities (SBSODS) yielded no significant group differences (t - 1.66, p 0.10) and was not reliably associated with objective accuracy in the pointing task. In patients without vestibular deficits, subjective spatial discomfort (EISOD) correlated with the accuracy in an objective 3D-pointing task for both cohorts, and higher discomfort was associated with more severe cognitive impairment. EISOD-scores showed higher correlation indices than a self-report of spatial skills using the SBSODS. When investigating spatial abilities in patients with suspected cognitive impairment, it appears reasonable that both subjective spatial discomfort, subjective spatial abilities, and objective spatial measures should be combined. Future research in patients with vestibular dysfunction is needed to understand the role of vestibular deficits for the development of spatial orientation discomfort.

Determination of Recovery by Total Restitution or Compensation Using Multifrequency Vestibular Tests and Subjective Functional Scales in a Human Model of Vestibular Neuritis.

Vestibular Neuritis (VN) can induce unilateral acute vestibular syndrome (AVS). This study aimed to identify predictive factors of recovery from vestibular neuritis considering total restitution and/or compensation. In this longitudinal study, 40 patients were included. The initial assessment, performed within 36 to 72 h from the onset (T0), included medical history taking (general and specific), including screening for cardiovascular risk factors (CVRFs), and a battery of diagnostic vestibular tests, comprising the bithermal caloric test (BCT), video head impulse test (VHIT), and skull vibration-induced nystagmus (SVIN) test. All patients also completed a Dizziness Handicap Inventory (DHI). All assessments were repeated 90 ± 15 days later (T3). Subjective compensation criteria were based on the DHI total score, and objective compensation criteria were based on laboratory test results. Four groups of patients (A, B, C, D) were delineated by combining patients with normal vs. abnormal vestibular tests and patients with normal vs. abnormal DHI. CVRFs (but not age or body mass index (BMI)) were associated with a poorer recovery of symptoms. The BCT (lateral semicircular canal paresis %), VHIT (lateral semicircular canal gain), and SVINT (nystagmus slow phase velocity) recovered to normal values in 20%, 20%, and 27% of patients, respectively, at T3. Vascular risk factors (hypercholesterolemia) are correlated with patients who do not recover their symptoms via either total restitution or compensation. There was no significant difference between high- and low-frequency vestibular tests in patients recovering from their symptoms. Some patients with objective recovery may continue to have persistent subjective symptoms.

Quality of life, physical symptoms, and psychological symptoms according to the status of chronic vestibulopathy.

Symptomatic vestibulopathy impairs patients' lives. However, few studies have explored the lives of patients with compensated or asymptomatic vestibulopathy. This study investigated the quality of life (QOL), psychological health, and physical function of patients with vestibulopathy. Using the eighth Korea National Health and Nutrition Examination Survey database, we included individuals with data on demographic factors, diabetes, hypertension, dizziness experiences, pure-tone audiometry, video head impulse test (vHIT), Health-related Quality of Life Instrument with 8 Items, General Anxiety Disorder 7-item scale, stress, and walking and sitting times. Participants were classified into the following groups: an uncompensated group with abnormal vHIT result and chronic dizziness, a compensated group with abnormal vHIT result and a history of dizziness, an asymptomatic group with abnormal vHIT result and no history of dizziness, and a normal group without abnormal vHIT result or a history of dizziness. Uncompensated vestibulopathy was more common in older individuals and women. The uncompensated group showed impairments in climbing stairs (P < 0.001), pain (P < 0.001), vitality (P = 0.001), working (P < 0.001), depression (P < 0.001), sleep (P = 0.001), happiness (P = 0.002), anxiety (P = 0.006), and stress (P = 0.003). The compensated group showed deficits in pain (P < 0.001), work (P = 0.006), sleep (P = 0.001), and happiness (P = 0.001). The asymptomatic group had no deficits in QOL, psychological health, or physical function. These tendencies were similar after controlling for age and gender. Vestibulopathy with a history of dizziness has a long-lasting impact on QOL and emotional status, even after compensation. Uncompensated vestibulopathy has a significant effect on QOL and mental health. Notably, though, the compensated group also showed a reduction in QOL. Appropriate interventions for each category of patients should be provided based on their impaired functions.

Predictive nomograms and an algorithm for managing patients with probable Meniere's disease

PurposeTo explore the efficacy of diagnostic tests in accurately reclassifying patients initially diagnosed with probable Meniere's disease (MD) into either definite or non-MD categories. Materials and methodsA retrospective cohort study was conducted at a neurotology clinic between 1/2016 and 5/2022. Patients underwent a battery of tests, from which sensitivity, specificity, positive and negative predictive values, as well as positive and negative likelihood ratios, were calculated. Additionally, prediction nomograms were developed. ResultsOf the 69 patients, 25 (36.2 %) were initially classified as definite MD, 21 (30.4 %), probable MD, and 23 (33.4 %) non-MD. The mean follow-up was 3.5 years. The sensitivity of electrocochleography (ECochG) was the highest (92 %), with a negative likelihood ratio of 15 %. Magnetic resonance imaging (MRI) with MD-protocol had the highest specificity (100 %), with a positive likelihood ratio of 100 %. Videonystagmography, video head impulse test, and cervical vestibular-evoked myogenic potentials, had lower sensitivity and specificity. We were able to reclassify 18 (86 %) patients with probable MD: 12 (57 %) were diagnosed with definite MD, and 6 (29 %) were diagnosed with non-MD, consistent with their clinical course. ConclusionsThe combination of ECochG and MRI with MD-protocol provides the most reliable approach to reclassify patients with Probable MD, ensuring a precise and accurate diagnosis. Vestibular tests express the functional status of the labyrinth and may not be reliable. Our findings provide valuable insights into clinical decision-making for patients with Probable MD and raise the consideration of additional diagnostic tests as supplementary to the existing clinical-only diagnosis criteria.

ADVANCEMENTS IN VESTIBULAR PHYSIOTHERAPY: A COMPREHENSIVE REVIEW

Purpose. Vestibular disorders pose significant challenges to individuals' daily functioning and quality of life, necessitating effective management strategies. This comprehensive review explores modern advancements in vestibular physiotherapy, encompassing assessment techniques, intervention modalities, technological innovations, and interdisciplinary collaboration. Material/Methods. Accurate assessment and diagnosis are essential for tailoring treatment plans to individual needs. Traditional clinical tests, such as the Dix-Hallpike maneuver and head impulse test (HIT), remain foundational while emerging technologies like video head impulse testing (vHIT) offer objective measures of vestibular function. Treatment of benign paroxysmal positional vertigo (BPPV) often involves canalith repositioning maneuvers (CRM), with recent modifications and augmented reality applications enhancing efficacy and patient comfort. Results. Vestibular rehabilitation therapy (VRT) plays a pivotal role in promoting central nervous system compensation for vestibular deficits. Incorporating exercises targeting balance, gaze stabilization, habituation, and sensory integration, VRT facilitates symptom reduction and functional improvement. Technological innovations, including virtual reality (VR) systems and smartphone applications, augment traditional VRT approaches, enhancing engagement and accessibility. Moreover, interdisciplinary collaboration among healthcare professionals ensures comprehensive management of vestibular disorders. Physiotherapists, otolaryngologists, neurologists, audiologists, and psychologists collaborate to deliver personalized care and empower patients through education and counseling. Conclusions. Modern vestibular physiotherapy offers a multifaceted approach to address the complex needs of individuals with vestibular disorders. By leveraging evidence-based practices, integrating technological solutions, and fostering interdisciplinary partnerships, healthcare providers can optimize treatment outcomes and enhance patients' overall well-being.

Vestibulometry, the registration of responses to stimulation of the vestibular organ with stimuli of different frequencies.

&lt;b&gt;Introduction:&lt;/b&gt; The vestibular organ (VO) is essential for maintaining balance and stabilizing visual images during head movements. To evaluate its function, the strength of the vestibulo-ocular reflex (VOR) is assessed using kinetic tests like the Sinusoidal Harmonic Acceleration Test (SHAT), video Head Impulse Test (vHIT), and slow-phase peak velocity (SPV) measurement in the caloric test (CT). Despite their limited sensitivity and specificity, they are used to determine eligibility for positions requiring strong balance control.&lt;b&gt;Aim:&lt;/b&gt; To determine the range of VOR gain in young healthy individuals in SHAT, vHIT and CT. To search for correlations between vestibular test results and age and gender of the subjects.&lt;b&gt;Materials and methods:&lt;/b&gt; Sixty two healthy individuals, with 32 males and 30 females, aged 7 to 33 who met the inclusion criteria were included in the study. Each participant underwent SHAT, vHIT and CT. Standard statistical methods and Spearman's rank correlation were used.&lt;b&gt;Results:&lt;/b&gt; The age of the subjects correlated negatively with the VOR gain in SHAT. There was no correlation between results for SHAT, vHIT or CT.&lt;b&gt;Discussion:&lt;/b&gt; Various factors, such as vestibular stimulation and anatomical variations, affect vestibular test results. While these tests complement each other in diagnosing vertigo, they are not recommended for healthy individuals qualifying for high-vestibular-performance occupations.&lt;b&gt;Conclusions:&lt;/b&gt; With age, the sensitivity of the VO to kinetic stimuli decreases. The inability to calibrate stimuli can result in varied responses among individuals. A comprehensive evaluation of the VO requires testing across different frequency ranges.

Vibration Thresholds Using Conventional Audiometry are Clinically Useful Indicators of Postural Instability in Older Adults.

Falls are a major health concern with potentially dramatic consequences for people over 65 years of age. One crucial determinant in the risk of falls in older adults is postural control, a complex process that requires the contribution of different sensory modalities, namely visual, vestibular, auditory, and somatosensory. While there are well-established methods to screen for age-related vision, hearing, tactile, and vestibular impairments, there are very few widely available methods to screen for somatosensory function, but studies indicate that ankle audiometry (vibration thresholds) using a common B-71 bone vibrator can serve that purpose. To date, unfortunately, this technique has received little attention as a tool to measure postural instability in older adults. The objective of the present study was to examine postural control in older adults with and without degradation of the somatosensory functions, as determined with ankle audiometry. This was standard group comparison. In total, 36 healthy elderly aged between 65 and 80 years old were divided into two groups (low vibration threshold [n = 18] and high vibration threshold [n = 18]). Standard audiometry, video head impulse test, vibration thresholds (big toe, ankle, and tibia), and static postural control task using a force platform were performed. Greater postural instability in participants with higher (worse) vibration thresholds as compared with participants with lower (better) vibration thresholds was observed even though both groups were comparable on hearing threshold and vestibular function. The results indicate that performing a simple vibration threshold evaluation, using a clinically available B-71 with a cut-off value of 42 dB hearing loss, could be an effective, fast, and easy-to-use procedure for detecting people at risk of falls.

The Impact of Sleep Deprivation on Video Head Impulse Test Results.

To investigate the association between sleep deprivation and vestibular dysfunction by Video Head Impulse Test (vHIT). This prospective clinical trial explores the impact of acute sleep deprivation on the vestibular-ocular reflex (VOR) in medical residents. The study involved healthy physicians from diverse medical disciplines. Participants underwent vHIT assessments before and after a 26-h shift. The examinations focused solely on the right lateral semicircular canal. Participants further completed a demographics and fatigue questionnaire, including the Fatigue Severity Scale (FSS) questionnaire and a Visual Analog Fatigue Score (VAFS). The study involved 30 medical residents. Participants experienced a statistically significant decrease in VOR gain in the right horizontal semicircular canal during a 26-h shift (p < 0.01). While the FSS and VAFS questionnaires showed no significant difference before and after the shift, the analysis of ∆VOR gain indicated a statistically significant increase associated with decreased sleep time during the shift (p = 0.018, 95% Confidence Interval [0.08, 0.68]). The most substantial increase in ∆VOR occurred between 22-26 h of sleep deprivation. No significant differences were observed in ∆VOR between genders, ages, disciplines, department shifts versus emergency room shifts, or years of residency. vHIT can be used as an objective, reliable screening tool for severe sleep deprivation among physicians. The decrease in the VOR gain may indicate that vestibular function is influenced by sleep deprivation. The clinical significance of these findings is still questioned, more studies may help to assess this effect. 3 Laryngoscope, 2024.

Dissociation between caloric test and the video head impulse test in individuals with auditory neuropathy spectrum disorders.

Dissociation between caloric test and the video head impulse test in individuals with auditory neuropathy spectrum disorders.

Toward Intelligent Head Impulse Test: A Goggle-Free Approach Using a Monocular Infrared Camera.

To assess vestibular function, video head impulse test (vHIT) is taken as the gold standard by evaluating the vestibulo-ocular reflex (VOR). However, vHIT requires the patient to wear a specialized head-mounted goggle equipment that needs to be calibrated before each use. For this, we proposed an intelligent head impulse test (iHIT) setting with a monocular infrared camera instead of the head-mounted goggle and contributed correspondingly a video classification approach with deep learning to vestibular function determination. Within the iHIT framework, a monocular infrared camera was set in front of the patient to capture test videos, based on which a dataset DiHIT of HIT video clips was set up. We then proposed a two-stage multi-modal video classification network, trained on the dataset DiHIT, that took as input the eye motion and head motion data extracted from the facial keypoints via HIT clips and outputted the identification of the semicircular canal (SCC) being tested (SCC identification) and determination of VOR abnormality (SCC qualitation). Experiments on this dataset DiHIT showed that it achieved the accuracy of 100% in prediction of SCC identification. Furthermore, it attained predictive accuracies of 84.1% in horizontal and 79.0% in vertical SCC qualitation. Compared with existing video-based HIT, iHIT eliminates goggles, does not require equipment calibration, and achieves complete automation. Furthermore, iHIT will bring more benefits to users due to its low cost and ease of operation. Codes and use case pipeline are available at: https://github.com/dec1st2023/iHIT. 3 Laryngoscope, 2024.

Video head impulse gain is impaired in myotonic dystrophy types 1 and 2.

This study was undertaken to examine vestibulo-ocular reflex (VOR) characteristics in myotonic dystrophy type 1 (DM1) and type 2 (DM2) using video head impulse testing (vHIT). VOR gain, refixation saccade prevalence, first saccade amplitude, onset latency, peak velocity, and duration were compared in DM1, DM2, age-matched normal controls, and patients with peripheral and central vestibulopathies. Fifty percent of DM1 and 37.5% of DM2 patients demonstrated reduced VOR gain. Refixation saccade prevalence for horizontal canal (HC) and posterior canal (PC) was significantly higher in DM1 (101 ± 42%, 82 ± 47%) and DM2 (70 ± 45%, 61 ± 38%) compared to controls (40 ± 28% and 43 ± 33%, p < 0.05). The first saccade amplitudes and peak velocities were higher in HC and PC planes in DM1 and DM2 compared to controls (p < 0.05). HC slow phase eye velocity profiles in DM1 showed delayed peaks. The asymmetry ratio, which represents the percentage difference between the first and second halves of the slow phase eye velocity response, was therefore negative (-22.5 ± 17%, -2.3 ± 16%, and - 4.7 ± 8% in DM1, DM2, and controls). HC VOR gains were lower and gain asymmetry ratio was larger and negative in patients with DM1 with moderate to severe ptosis and a history of imbalance and falls compared to the remaining DM1 patients (p < 0.05). In peripheral vestibulopathies, saccade amplitude was larger, peak velocity was higher, and onset latency was shorter (p < 0.05) than in DM1. In central vestibulopathy (posterior circulation strokes), saccade peak velocity was higher, but amplitude and onset latency were not significantly different from DM1. VOR impairment is common in DM1 and DM2. In DM1, refixation saccade characteristics are closer to central than peripheral vestibulopathies. Delayed peaks in the vHIT eye velocity profile observed in patients with DM1 may reflect extraocular muscle weakness. VOR impairment and VOR asymmetry in DM1 are associated with imbalance and falls.

Vestibular Dysfunction in Euthyroid Children with Hashimoto's Thyroiditis.

A relationship exists between autoimmune thyroid disorders and vestibular dysfunction. This study aimed to analyze cervicalevoked myogenic potentials (cVEMP) and video head impulse test (vHIT) results between children with Hashimoto thyroiditis (HT) and healthy controls to determine vestibular end-organ problems. Thirty-six children with HT and 30 healthy subjects were recruited. The main inclusion criteria for the healthy group were the presence of normal thyroid function and no clinical history of vestibular problems. Each participant (both HT and healthy groups) was assessed using audiovestibular tests, cVEMP, and vHIT. There was no significant difference between the groups in terms of cVEMP (p1 and n1) latencies for both ears. There was no significant difference in cVEMP amplitudes (p1-n1 peak-to-peak) between the groups. There were statistically significant differences in the VOR gain of the right and left ears between the groups (P < .001, P < .001). When we considered lower cutoff value as 0.80 for VOR gain, 29 of 36 patients with HT (80.6%) had lower VOR gain scores. Only 1 of 30 healthy participants (3.3%) had a lower VOR gain score. This difference was statistically significant (P < .001). Subclinical vestibulopathy may occur in children with HT. The vHIT seems to be a valuable tool for identifying and screening preclinical vestibular pathologies in this patient group.

Evidence of Peripheral Vestibular Impairment Among Adults With Chronic Moderate-Severe Traumatic Brain Injury.

Traumatic brain injury (TBI) is a leading cause of death and disability among adults in the United States. There is evidence to suggest the peripheral vestibular system is vulnerable to damage in individuals with TBI. However, there are limited prospective studies that describe the type and frequency of vestibular impairment in individuals with chronic moderate-severe TBI (> 6 months postinjury). Cervical and ocular vestibular evoked myogenic potentials (VEMPs) and video head impulse test (vHIT) were used to assess the function of otolith organ and horizontal semicircular canal (hSCC) pathways in adults with chronic moderate-severe TBI and in noninjured comparison (NC) participants. Self-report questionnaires were administered to participants with TBI to determine prevalence of vestibular symptoms and quality of life associated with those symptoms. Chronic moderate-severe TBI was associated with a greater degree of impairment in otolith organ, rather than hSCC, pathways. About 63% of participants with TBI had abnormal VEMP responses, compared to only ~10% with abnormal vHIT responses. The NC group had significantly less abnormal VEMP responses (~7%), while none of the NC participants had abnormal vHIT responses. As many as 80% of participants with TBI reported vestibular symptoms, and up to 36% reported that these symptoms negatively affected their quality of life. Adults with TBI reported vestibular symptoms and decreased quality of life related to those symptoms and had objective evidence of peripheral vestibular impairment. Vestibular testing for adults with chronic TBI who report persistent dizziness and imbalance may serve as a guide for treatment and rehabilitation in these individuals.