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

BACKGROUND AND PURPOSE: 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). METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

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.

Changes in vestibular-related responses to combined noisy galvanic vestibular stimulation and cerebellar transcranial direct current stimulation.

Vestibular nuclei and cerebellar function comprise vestibular neural networks that control vestibular-related responses. However, the vestibular-related responses to simultaneous stimulation of these regions are unclear. This study aimed to examine whether the combination of noisy galvanic vestibular stimulation (nGVS) and cerebellar transcranial direct current stimulation (ctDCS) using a complex transcranial electrical stimulation device alters vestibular-dominant standing stability and vestibulo-ocular reflex (VOR) function. The center of foot pressure (COP) sway and VOR of participants (28 healthy, young adults) were assessed under four conditions of transcranial electrical stimulation using nGVS and ctDCS. The COP was calculated with the participant standing on a soft-foam surface with eyes closed using a force plate to evaluate body sway. VOR measurements were collected via passive head movements and fixation on a target projected onto the front wall using a video head impulse test (vHIT). VOR gain was calculated in six directions using a semicircular canal structure based on the ratio of eye movement to head movement. The nGVS + ctDCS and nGVS + sham ctDCS conditions decreased COP sway compared to the sham nGVS + ctDCS and sham nGVS + sham ctDCS conditions. No significant differences were observed in the main effect of stimulation or the interaction of stimulation and direction on the vHIT parameters. The results of this study suggest that postural stability may be independently affected by nGVS. Our findings contribute to the basic neurological foundation for the clinical application of neurorehabilitation using transcranial electrical stimulation of the vestibular system.

Effects of valproic acid and levetiracetam monotherapy on balance functions in patients with generalized epilepsy.

BACKGROUND: It is reported that antiepileptic drugs have an effect on balance functions. The aim of the study was to evaluate and compare the effects of valproic acid and levetiracetam monotherapy on balance functions in patients with generalized epilepsy using objective test methods. METHODS: The study included 43 generalized epilepsy patients aged 18-60 years, including 20 patients receiving valproic acid monotherapy, 23 patients receiving levetiracetam monotherapy, and 25 healthy individuals as controls, in the Neurology Clinic of a university hospital in eastern Turkey. The demographic data form was filled out and the Video Head Impulse Test and Vestibular Evoked Myogenic Potentials test were performed. RESULTS: Statistically significant differences were obtained between the groups in lateral, posterior, and anterior semicircular canal gains and RALP and LARP asymmetry values in the V-HIT test (p < 0.05). Statistically significant differences were obtained between the groups in P1, N1 latency and asymmetry values in the C-VEMP test and in N1, P1 latency, amplitude, and asymmetry values in the o-VEMP test (p < 0.05). CONCLUSION: Valproic acid and levetiracetam may affect the vestibulocular and vestibulocolic reflex pathways negatively. In this cohort, valproic acid had more pronounced adverse effects on balance functions as compared to levetiracetam.

Evaluation of the Vestibulo-Ocular Reflex Using the Video Head Impulse Test in Patients with Unilateral Chronic Otitis Media.

INTRODUCTION: The aim of the study was to evaluate the vestibulo-ocular reflex (VOR) using the video head impulse test (vHIT) as a vestibular function assessment method in patients with unilateral chronic otitis media (COM). METHODS: Twenty-eight patients with unilateral COM scheduled for middle ear surgery, including 12 males and 16 females with a mean age of 54.5 years, successfully underwent preoperative vHIT. vHIT variables, including VOR gain, VOR gain asymmetry, and the incidence of corrective saccades, were compared between the ipsilesional and contralesional ears. RESULTS: Ten (35.7%) patients reported varying degrees of disequilibrium or lightheadedness. The VOR gain in the ipsilesional and contralesional ears was 1.01 ± 0.10 and 1.04 ± 0.11, 0.97 ± 0.12 and 0.94 ± 0.13, and 0.97 ± 0.13 and 1.04 ± 0.15 in the horizontal canal (HC), anterior canal, and posterior canal (PC), respectively. The average VOR gains in the ipsilesional ears were within the predefined range of normal values; however, the gains in HC and PC significantly decreased compared with those in contralesional ears (p = 0.038 in HC and p = 0.015 in PC). The prevalence of corrective saccades, including overt and/or covert saccades, did not differ significantly between the two ears. CONCLUSION: This study assessed the pathophysiology of the inner ear affected by chronic middle ear infection by quantitatively comparing the VOR using vHIT. It demonstrated that vHIT can be a practical assessment of vestibular function in patients with COM.

Subjective visual vertical/horizontal and video head impulse test in dyslexic children.

Different studies have tried to establish a relationship between dyslexia and the vestibular system function. Subjective Visual Vertical/Horizontal (SVV and SVH) and Video Head Impulse Test (VHIT) are useful for studying the vestibular system and can be easily performed in children. Our aim was to evaluate the vestibular function in dyslexic children by SVV/SVH and VHIT. We enrolled 18 dyslexic children (10M/8F; mean age 10.7 ± 2.3 years; range 7-14 years) and 18 age-matched children with typical development of learning abilities. All children performed VHIT, SVV and SVH. We found normal gain and symmetry of vestibulo-ocular-reflex both in dyslexic and typically developing children. Fifteen out of 18 dyslexic children (83.3%) showed a difference of at least one amongst SVV or SVH. The mean value of SVV was 2.3° and the mean value of SVH was 2.6°. Statistical analysis showed a significant difference between typically developing and dyslexic children for both SVV and SVH. We confirm a relationship between dyslexia and the alteration of SVV and SVH. Our results could be related to the pathogenetic hypothesis of a visual processing impairment related to a dysfunction of the magnocellular pathway or to a general deficit related to a multimodal cortical network.

Analysis of head and eye dynamic may explain saccades in dizzy patients with normal VOR gain.

OBJECTIVE: Compare the vestibulo-ocular reflex (VOR) gain, compensatory saccades and head and eye coordination during head impulses between patients with dizziness but normal VOR gain and healthy controls. METHODS: Video head impulses test (vHIT; ICS impulse, Otometrics, Denmark) was reviewed in 40 participants (20 patients with dizziness; 20 controls). VOR gain, saccades characteristics (frequency of occurrence, amplitude, latency) and time difference between head and eye velocity was compared. RESULTS: No significant difference between groups was observed for VOR gain. However, saccade frequency was greater and time difference between head and eye was prolonged in patients with dizziness. No significant difference was observed for saccade amplitude, nor for saccade latency between groups. CONCLUSIONS: The present study highlights that saccades observed in patients with normal VOR gain could reflect a clinical marker for dizziness in patients with normal VOR gain. We propose that theses saccades are caused by a prolonged time delay between head and eye velocity leading to a gaze position error. SIGNIFICANCE: The results support previous findings suggesting additional value of saccades and time delay when interpreting vHIT results. This study goes further by proposing time delay as a possible mechanism to explain increased saccade frequency in dizzy patients with normal VOR gain.

Do high-risk head trauma sports athletes have impaired vestibular function?

PURPOSE: The primary aim of this study was to examine the vestibular function of athletes involved in high-risk head trauma sports by means of complete vHIT testing of all six semicircular canals (SCCs). The secondary objective was to investigate whether the vestibular function is significantly reduced among athletes within certain high-risk sports. METHODS: A prospective cross-sectional study of 137 adult athletes in football, handball, boxing, horseback riding, and ice hockey with a minimum of one reported sports-related head injury within the past five years. All subjects underwent screening with a complete examination of all six SCCs with vHIT and fulfillment of the dizziness handicap inventory (DHI). RESULTS: Two subjects (1.5 %) fulfilled the criteria of having a pathological vHIT. Some degree of impairment of the vestibular function was seen when data was divided into individual sports and time since the last head injury. Likewise, no subjective dizziness was seen in the group of athletes when evaluated by total DHI scores. This score did not differ significantly between groups when subgrouped into number of head injuries or time since the last head injury. When divided into type of sport, total DHI scores differed significantly between groups. These total DHI-scores did, however, all fall within the range of the "no dizziness handicap" classification. CONCLUSION: The results suggest that the vestibular function of athletes in high-risk head trauma sports is unaffected by the practice of a high-risk head trauma sport. Therefore, vHIT has no clinical utility in the assessment of a sports-related concussion (SRC) in athletes with no subjective feeling of dizziness.

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

PURPOSE: To 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 METHODS: A 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. RESULTS: Of 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. CONCLUSIONS: The 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.

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.

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.

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

OBJECTIVE: Resection of the vestibular schwannoma causes acute peripheral vestibular loss. The process of central compensation starts immediately afterward. The rehabilitation goal is to support this process and restore the quality of life. MATERIALS AND METHODS: In this prospective single-center study, 67 consecutive patients underwent vestibular schwannoma resection (40 females, mean age 52 ± 12 years). The patients were divided into three groups: the prehabilitation with intratympanic gentamicin group, the virtual reality group (optokinetic stimulation via virtual reality goggles in the first ten days after the surgery), and the control group. All patients were examined with objective methods and completed questionnaires before the prehabilitation, before the surgery, at the hospital discharge, and after three months. RESULTS: Intratympanic gentamicin prehabilitation leads ipsilaterally to a significant aVOR reduction in all semicircular canals (p < 0.050), the increase of the unilateral weakness in air calorics (p = 0.026), and loss of cVEMPs responses (p = 0.017). Prehabilitation and postoperative exposure to virtual reality scenes improved the patient's perception of vertigo problems according to Dizziness Handicap Inventory (p = 0.039 and p = 0.076, respectively). These findings conform with the optokinetic testing results, which showed higher slow phase velocities at higher speeds (40 deg/s) in both targeted groups compared to the control group. CONCLUSION: Preoperative intratympanic gentamicin positively affects peripheral vestibular function, influencing balance perception after VS resection. In long-term follow-up, prehabilitation and postoperative exposure to virtual reality improve patients' quality of life in the field of vertigo problems.

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.

Evaluating vertebrobasilar insufficiency and Meniere's disease: Insights from cervical vestibular evoked myogenic potential and video head impulse test.

Background and purpose:

This prospective study aimed to investigate diffe-rences in video head impulse test (vHIT) and cervical vestibular evoked myogenic poten-tial (cVEMP) findings between patients with vertebrobasilar insufficiency (VBI) and Meniere’s disease (MD) who experience episodic vertigo attacks.

A total of 27 patients with VBI and 37 patients with MD were enrolled into the study in a tertiary referral center. Inclusion criteria consisted of patients with a minimum of two previous vertigo attacks, unaccompanied by any neurological symptoms during an attack. All patients underwent horizontal canal h-vHIT and c-VEMP assessments following pure sound audiometric examinations. First, vHIT and cVEMP results for low and high flow sides in VBI patients were analyzed. Subsequently, data from the low-flow side in VBI patients and the affected side in MD patients were compared.

The mean vHIT values for low and high-flow volume sides in VBI patients were 0.68 and 0.88, respectively. In MD patients, mean vHIT values for affected and healthy sides were measured as 0.77 and 0.87, respectively. Abnormal results were observed in 66.7% of VBI patients and 51.4% of MD patients, with no statistically significant difference between the findings (p> 0.05). Upon examining the affected side, c-VEMP responses were absent in 41% of MD patients and 48% of VBI patients, with no statistically significant difference between the groups (p> 0.05).

vHIT and cVEMP assessments can be utilized as supplementary tools to radiologic investigations for the clinical diagnosis and follow-up of VBI. However, no significant differences were observed between vHIT and cVEMP findings in patients with MD and VBI.

Changes of video head impulse test before and after translabyrinthectomy in patients with acoustic neuroma. / å¬ç¥žç»ç˜¤æ‚£è€ ç»è¿·è·¯åˆ‡é™¤æœ¯å‰åŽè§†é¢‘å¤´è„‰å†²è¯•éªŒçš„å˜åŒ–.

OBJECTIVES: Acoustic neuroma (AN) is a benign tumor that usually affects a patient's hearing and balance function. For the screening and diagnosis of AN, the traditional approach mainly relies on audiological examination and magnetic resonance imaging (MRI), often ignoring the importance of vestibular function assessment in the affected area. As an emerging method of vestibular function detection, video head impulse test (vHIT) has been widely used in clinic, but research on its use in AN diagnosis is relatively limited. This study aims to explore the value of vHIT in the diagnosis of AN, vestibular dysfunction assessment, and postoperative compensation establishment in unilateral AN patients undergoing unilateral AN resection through labyrinthine approach. METHODS: This retrospective study was conducted on 27 AN patients who underwent unilateral AN resection via labyrinthine approach from October 2020 to March 2022 in the Department of Otolaryngology-Head and Neck Surgery, the Second Xiangya Hospital, Central South University. vHIT was performed 1 week before surgery to assess vestibular function, pure tone audiometry (PTA) was used to assess hearing level, and ear MRI was used to assess tumor size. Follow-up vHIT was conducted at 1 week, 1 month, 6 months, and 1 year post-surgery. The correlation of vHIT with hearing and tumor size was analyzed. RESULTS: Preoperative vHIT showed that the posterior semicircular canal on the affected side was the most common semicircular canal with reduced vestibulo-ocular reflex (VOR) gain. There was a correlation between the VOR gain of vHIT on the affected side and the hearing level (r=-0.47, P<0.05) or tumor size (r=-0.54, P<0.01). The results of vHIT on the affected side showed that the hearing level and mean VOR gain of the anterior semicircular canal increased slightly with time, and the amplitude and saccade percentage of the dominant saccades of the 3 semicircular canals increased, while the latency time decreased, with the most obvious changes occurring 1 week post-surgery. CONCLUSIONS: vHIT can effectively monitor the changes of vestibular function in AN patients before and after surgery and has application value in assisting the diagnosis of vestibular dysfunction in AN patients.

[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.

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

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

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

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

Assessment of vestibulo-ocular reflex and its adaptation during stop-and-go car rides in motion sickness susceptible passengers.

Motion sickness is a physiological condition that negatively impacts a person's comfort and will be an emerging condition in autonomous vehicles without proper countermeasures. The vestibular system plays a key role in the origin of motion sickness. Understanding the susceptibility and (mal) adaptive mechanisms of the highly integrated vestibular system is a prerequisite for the development of countermeasures. We hypothesize a differential association between motion sickness and vestibular function in healthy individuals with and without susceptibility for motion sickness. We quantified vestibular function by measuring the high-frequency vestibulo-ocular reflex (VOR) using video head impulse testing (vHIT) in 17 healthy volunteers before and after a 11 min motion sickness-inducing naturalistic stop-and-go car ride on a test track (Dekra Test Oval, Klettwitz, Germany). The cohort was classified as motion sickness susceptible (n = 11) and non-susceptible (n = 6). Six (out of 11) susceptible participants developed nausea symptoms, while a total of nine participants were free of these symptoms. The VOR gain (1) did not differ significantly between participant groups with (n = 8) and without motion sickness symptoms (n = 9), (2) did not differ significantly in the factor time before and after the car ride, and showed no interaction between symptom groups and time, as indicated by a repeated measures ANOVA (F(1,15) = 2.19, p = 0.16. Bayesian inference confirmed that there was "anecdotal evidence" for equality of gain rather than difference across groups and time (BF10 < 0.77). Our results suggest that individual differences in VOR measures or adaptation to motion sickness provocative stimuli during naturalistic stop-and-go driving cannot predict motion sickness susceptibility or the likelihood of developing motion sickness.

Correlations of Clinical and Audio-Vestibulometric Findings with Coexisting Anxiety and Depression in Ménière's Disease Patients.

INTRODUCTION: Ménière's disease (MD) is an inner ear disorder, characterized by vertiginous attacks, fluctuating sensorineural hearing loss, tinnitus, and a feeling of ear fullness. Endolymphatic hydrops has been proven as the underlying pathology. Frequently, psychopathologies accompany the disease. The aim of this study was to investigate the correlation of anxiety and depression with demographic, clinical, and audio-vestibular findings in MD patients. METHODS: The study included 40 consecutive unilateral MD patients. Demographic data (age, sex, education, employment, and marital status), clinical variables of drop attacks, the duration, frequency and severity of vertigo attacks, and tinnitus disturbance levels were recorded. Hearing threshold levels were graded between 1 and 4. Vestibulometric variables were taken as the presence of saccades and vestibulo-ocular reflex (VOR) gain deficits in the video head impulse tests (vHIT) and canal paresis in bithermal caloric tests. Becks's depression and anxiety scales were used for psychometric evaluations and graded by 4 and 5 from normal to severe and normal to very severe, respectively. RESULTS: The median age of the patients was 48.94 years, and the numbers of both sexes were almost equal (male/female = 19/21). All patients reported at least one vertigo attacks within the last year. The duration of attacks was most commonly (62.5%) 1-3 h, ranging from <1 h to 17 h. Most attacks were graded as mild (67.5%), and the frequency was 2-3 episodes per year in 22 (55%) patients. The number of attacks within the last year was 1-12. Three patients reported having drop attacks. Hearing loss in the affected ear was moderate/moderately severe in 20 (50%) patients. Thirty-seven (92.5%) patients had complaints of tinnitus. In vHIT, saccades and VOR gain deficits were found in 33 (82.5%) and 11 (27.5%) patients, respectively. Canal paresis was present in 18 (45%) patients. The depression and anxiety rates were 35% and 90%, respectively. Depression scores were correlated with education, marital status, and the presence of saccades. Anxiety was correlated only with tinnitus severity and VOR gain deficits. Depression and anxiety were also correlated. CONCLUSION: Vertigo appears to be more intrusive than the other MD symptoms, and a higher correlation with anxiety than depression was demonstrated in this cohort. However, depression was seen less among married and educated patients, suggesting the role of coping capability, and had more pronounced clinical/vestibulometric correlates. Overall, these results indicated that it is mainly the severity of organic/physiological pathology which determines the degree of depression and anxiety in MD rather than vice versa.