Acute vestibulopathy with simultaneous bilateral involvement of the vestibulo-ocular reflex limited to the low-frequency range

We report a novel type of idiopathic bilateral vestibulopathy with acute simultaneous involvement of the vestibulo-ocular reflex limited to the low-frequency range. A 64-year-old female presented with dizziness, oscillopsia, and difficulty walking. She did not experience rotatory vertigo and did not show any nystagmus. Vestibular function tests showed absent caloric responses in both ears, while vestibulo-ocular reflex (VOR) gains in the video head impulse test (vHIT) were preserved in all six semicircular canals. Cervical and ocular vestibular evoked myogenic potentials in response to air-conducted sound were absent on both sides. Since the caloric test and vHIT measures low-frequency and high-frequency VOR, respectively, we diagnosed the patient as having a bilateral VOR deficit limited to the low-frequency range. During a 1-year follow-up with vestibular rehabilitation, the subjective symptom of dizziness gradually recovered while recovery of vestibular function was minimal.     

视频头脉冲试验在眩晕疾病诊断中的应用研究

目的 探讨视频头脉冲试验(vHIT)评估周围性眩晕患者前庭眼反射(VOR)的临床价值.方法 选取2019年4月-2020年10月收治的52例良性阵发性位置性眩晕(BPPV)患者和57例前庭性神经炎(VN)患者为研究对象,并选取同期30名健康者作为对照.采用vHIT定量测定一对水平半规管平面、两对垂直半规管平面的VOR增...     

Repeated video head impulse testing in patients is a stable measure of the passive vestibulo-ocular reflex

ObjectivesThe video head impulse test (vHIT) is used as a measure of compensation yet it’s stability in patients with vestibular pathology is unknown.Methods144 patients (n = 72 female, mean 54.46 ± 15.8 years) were grouped into one of three primary diagnoses (Peripheral, Central, or Mixed). Subjects were further categorized based on sex (male versus female), ear (left versus right; ipsilesional versus contralesional), age (six groups ranging from 19 to 84 years), and duration between visits (five groups, mean 191.46 ± SE 29.42 days, median 55.5 days). The gain of the VOR during passive head rotation was measured for each semicircular canal (horizontal, anterior, posterior).ResultsThere was no difference in the VOR gain within any semicircular canal between the two visits (horizontal: p = 0.179; anterior: p = 0.628; posterior: p = 0.613). However, the VOR gain from the horizontal canals was higher than the vertical canals for each visit (p < 0.001). Patients diagnosed with peripheral vestibular pathology had significantly lower (p ≤ 0.001) horizontal semicircular canal gains at each visit. There was no difference in VOR gain between sex (p = 0.215) or age groupings (p = 0.331). Test-retest reliability of vHIT in patient subjects is good (ICC = 0.801) and the VOR gain values across two separate visits were significant and positively correlated (r = 0.67) regardless of sex, ear, age, or duration between visits.ConclusionThe vHIT is a stable measure of VOR gain over two different times across a variety of vestibular patients with no influence of age or sex.     

Detection of isolated covert saccades with the video head impulse test in peripheral vestibular disorders

Objectives

The function of the semicircular canal receptors and the pathway of the vestibulo-ocular-reflex (VOR) can be diagnosed with the clinical head impulse test (cHIT). Recently, the video head impulse test (vHIT) has been introduced but so far there is little clinical experience with the vHIT in patients with peripheral vestibular disorders. The aim of the study was to investigate the horizontal VOR (hVOR) by means of vHIT in peripheral vestibular disorders.

Methods

Using the vHIT, we examined the hVOR in a group of 117 patients and a control group of 20 healthy subjects. The group of patients included vestibular neuritis (VN) (n = 52), vestibular schwannoma (VS) (n = 31), Ménière's disease (MD) (n = 22) and bilateral vestibulopathy (BV) (n = 12).

Results

Normal hVOR gain was at 0.96 ± 0.08, while abnormal hVOR gain was at 0.44 ± 0.20 (79.1% of all cases). An abnormal vHIT was found in VN (94.2%), VS (61.3%), MD (54.5%) and BV (91.7%). Three conditions of refixation saccades occurred frequently in cases with abnormal hVOR: isolated covert saccades (13.7%), isolated overt saccades (34.3%) and the combination of overt and covert saccades (52.0%).

Conclusions

The vHIT detects abnormal hVOR changes in the combination of gain assessment and refixation saccades. Since isolated covert saccades in hVOR changes can only be seen with vHIT, peripheral vestibular disorders are likely to be diagnosed incorrectly with the cHIT to a certain amount.     

Video head impulse in comparison to caloric testing in unilateral vestibular schwannoma

Conclusions: Although there was a statistically significant relationship between the results of the vHIT and the caloric test, the limited strength of this relationship suggests that, for unilateral vestibular schwannoma (UVS), caloric testing and vHIT may provide complementary information on vestibular function.

Objective: There is limited information that can be used to determine which of the video head impulse test (vHIT) and caloric test might be better used in the diagnosis and management of UVS. In this study, a group of participants with un-operated UVS was studied using both methods.

Methods: The subjects’ vestibular function was assessed using the vHIT and caloric testing. Tumour size was quantified using MRI and their balance disturbance assessed using the Jacobsen Dizziness Handicap Inventory (DHI).

Results: Twenty of 30 subjects had an abnormal canal paresis according to the Jongkees’ criterion (>?0.25); however, only 10/30 had an ipsilesional vHIT gain of <0.79. Canal paresis could be predicted from the ipsilesional and contralesional vHIT gains. Tumour size could also be predicted from the ipsilesional vHIT gain and canal paresis. However, DHI scores could not be predicted from the degree of canal paresis, vHIT gain, or the MRI measures.     

Exploración clínica y videoasistida del reflejo vestíbulo-oculomotor: análisis comparativo

IntroductionThe assessment of the vestibulo-ocular reflex (VOR) is one of the main steps in clinically evaluating patients with dizziness. It can be performed at the bedside with common head-impulse test in which eye position is analysed at the end of the head-thrust. It is an important test due to its high specificity but low sensitivity.Material and methodsWe studied 179 patients with different types of balance- affecting disorders. The results were analysed in contingency tables. The clinical test was classified as normal or abnormal according to the absence or existence, respectively, of fixation saccades once the head-thrust was ended. The video head-impulse test (vHIT) was classified according to vestibulo-ocular reflex (VOR) gain and presence of fixation saccades. The speed of the slow phase of spontaneous nystagmus was also quantified, as well as the caloric test results.ResultsThere were significant differences (Chi-square test, P=0.00) for the findings in the clinical evaluation and with the vHIT: 32.1% of the tests performed yielded different findings in both tests. In the vHIT, the differences were due to the finding of normal gain with saccades; in these patients, the mean canal paresis was significantly abnormal: 39%±10%.ConclusionsThe distribution of findings for the VOR bedside examination and for that with the help of a video system are significantly different; as such, the video head-impulse examination is not simply an added VOR detection and registration system. The difference relies mainly on a vHIT response characterised as of normal gain but with fixation saccades. These have been considered as the cause for the low sensitivity of the bedside VOR examination and sometimes regarded as normal responses; we have demonstrated that these findings are abnormal according to the findings of higher canal paresis in the caloric test.     

Der Video-Kopfimpulstest

Background

Side-specific test procedures are mandatory in order to assess the function of peripheral vestibular receptors. Semicircular canals (SCC) and vestibulo-ocular reflex (VOR) can be tested by the Halmagyi and Curthoy head impulse test (HIT) and recently by means of the video head impulse test (vHIT). The vHIT procedure is a new method to measure eye and head velocity during brief and rapid head impulses. This method provides objective information of VOR and detects both overt and covert catch-up saccades.

Materials and methods

As clinical experiences with vHIT are limited, in this study the horizontal VOR (hVOR) was examined by means of the vHIT in 142 consecutive patients with acute or chronic vestibular syndrome.

Results

A total of 20 healthy volunteers served as a control group and exhibited a normal average VOR gain of 0.97?±?0.09 without re-fixation saccades. In patients, 47.6% showed a pathological vHIT whereas 52.4% revealed a normal test result. Covert catch-up saccades could be revealed in 13.7% by means of vHIT whereas in 86.3% overt catch-up saccades alone or in combination with covert catch-up saccades were found in the majority of catch-up saccades in peripheral vestibular disorders.

Conclusions

By means of the vHIT it is possible to obtain a side-specific and quantitative assessment of hVOR. Video-head impulse test is a reliable tool for vestibular testing even in bedside examinations of patients suffering from dizziness.     

Factors affecting the outcome of vestibular rehabilitation in patients with peripheral vestibular disorders

ObjectivePrevious studies have reported that developmental, environmental, medical, psychological, visual, and other sensory-related factors can influence the outcome of vestibular rehabilitation. However, only a few studies have used patient's daily lives as the main outcome. In addition, in some studies, rehabilitation was not supervised by a physical therapist. This study aimed to determine the factors associated with the outcome of physical-therapist-supervised vestibular rehabilitation in patients with peripheral vestibular disorders, with the impact of dizziness on quality of life as the main outcome.MethodsThis retrospective cohort study included 47 patients with peripheral vestibular disorders. A physical therapist provided 40 min of vestibular rehabilitation once a week for 4 weeks. Age, sex, disease duration, Dizziness Handicap Inventory (DHI), Timed Up-and-Go test (TUG), Dynamic Gait Index (DGI), Functional Gait Assessment (FGA), Activity-Specific Balance Confidence Scale (ABC scale), and Hospital Anxiety and Depression Scale (HADS) were investigated. Multiple regression analysis was performed, with the DHI rate of change before and after the intervention as the objective variable.ResultsVestibular rehabilitation improved all outcomes. In the multiple regression analysis, the ABC scale was identified as a factor that significantly influenced the DHI rate of change (β = -0.428, p < 0.01).ConclusionA higher ABC scale score was associated with a lower DHI rate of change (i.e., better improvement). Therefore, it may be important to assess psychological aspects, especially confidence in balance, when implementing vestibular rehabilitation in patients with peripheral vestibular disorders.     

Preliminary results of video Head Impulse Testing (vHIT) in children with cochlear implants

ObjectiveTo evaluate the lateral semicircular canal high frequency vestibulo-oculomotor reflex (LSC HF VOR) in children with cochlear implant.Methods16 children (10 females and 6 males, age range = 5–17 years) receiving a unilateral (n = 12) or a bilateral (n = 4) cochlear implant were included and compared to a control group of 20 age-matched normal-hearing (NH) children. Both implanted and NH children received a vestibular function test battery, including a Vestibulo-Ocular Reflex (VOR) gain assessment by means of a video-Head Impulse Test (vHIT), which represented the main outcome measure. In implanted subjects, vHIT was measured on both sides in the “CI-ON” and “CI-OFF” conditions.ResultsOverall, no significant LSC HF VOR gain difference was found between CI users and NH peers. In the unilaterally implanted group, the LSC HF VOR gain measured in the “CI-ON” condition was significantly higher than in the “CI-OFF” condition, both in the implanted and in the non-implanted ear. In the bilaterally implanted group there was no such a difference between the two conditions, on either side.ConclusionThis is the first study investigating the LSC HF VOR gain in children with unilateral and bilateral CI. The study demonstrates that the LSC HF VOR of bilaterally implanted children is comparable to normal hearing children.     

Clinical use of child-friendly video head impulse test in dizzy children

ObjectiveTo investigate the high-frequency vestibular functions using a child-friendly video head impulse test and to classify vestibular symptoms using a standard nomenclature guideline in dizzy children.Materials and methodsThe video head impulse test with a remote camera was used in this study. The data of 40 dizzy children (7.30 ± 4.75 years) were analyzed retrospectively.ResultsThe high-frequency vestibulo-ocular reflex gains of 14 (35%) dizzy children in the study group were reduced, whereas the vestibulo-ocular reflex gains of 26 (65%) dizzy children were normal. Two of them had a dramatic reduction in vestibulo-ocular reflex gains on their affected SCCs, but no corrective saccades as their gazes had not been fixated on the target at the onset of head impulses. In dizzy children, the most common cause was inner ear malformation (15%) and the most common vestibular symptom was unsteadiness (25%).ConclusionThe high-frequency vestibular function of the VOR in dizzy children, especially those suffering from IEM and unsteadiness, can be quickly screened using the vHIT device with the remote camera. However, clinicians should be careful during the interpretation of traces in the pediatric group.     

A new method to improve the imbalance in chronic unilateral vestibular loss: the organization of refixation saccades

Conclusion: VOR adaptation and organization of refixation saccades in a gathered pattern is a process that can be artificially induced in patients with unilateral vestibular loss who have not developed it naturally, improving imbalance and vestibular disability.

Objective: To test that temporary grouping of refixation saccades should be linked to better clinical status without gain recovery.

Methods: A training to induce the refixation saccades into gathered fashion is performed. The outcome measures are handicap level measured by the dizziness handicap index (DHI) and refixation saccades organization pattern measured by a numeric score called ‘PR’ given by a software developed by the authors. Analysis is done before the training and 1 and 3 months after ending, Non-parametric tests were used for statistical analysis.

Results: This study has included 10 healthy subjects (four males, six females), and 16 patients with chronic unsteadiness due to unilateral vestibular loss (nine vestibular neuritis, four post-surgical vestibular schwannoma, and three cases after intra-tympanic gentamycin in patients with Ménière’s disease). The reduction in the DHI score was significant at 1 (p?=?0.028) and 3 months (p?=?0.042) post-treatment. Also, statistically significant differences were found between the PR score before and PR score 1 (p?=?0.005) and 3 months after the treatment (p?=?0.003).     

Objective measurement of HINTS (Head Impulse,Nystagmus, Test of Skew) in peripheral vestibulopathy

ObjectiveTo evaluate how often the positive sign of HINTS (Head-Impulse, Gaze Evoked Nystagmus, Test of Skew) appears in patients with acute peripheral vestibular lesion, HINTS findings were quantitatively measured and analyzed in patients with peripheral vestibulopathy accompanying spontaneous nystagmus.MethodsHINTS was evaluated in 14 vertigo patients with spontaneous nystagmus. Horizontal vestibulo-ocular reflex (VOR) gain was measured using the video head impulse test (vHIT). To evaluate gaze-evoked nystagmus (GEN), slow-phase velocities at different points of lateral gaze were measured and plotted, then the slope and its inverse value, the neural integrator time constant, were calculated. Skew deviation was tested using anaglyph filters to simulate the alternate cover test, and the degree and latency of vertical eyeball deviation were measured. The ABCD2 score was calculated to evaluate the risk of stroke.ResultsAmong 13 patients of peripheral vestibulopathy, 7 showed positive signs in HINTS (normal vHIT: 5, direction-changing GEN: 0, skew deviation: 3). One patient with a cerebellopontine angle tumor presented with both a peripheral and central pattern and showed positive HINTS findings (presence of direction-changing GEN). The mean VOR gain of patients with abnormal vHIT was 0.58±0.29 and 1.10±0.11 in the affected and contralateral side, respectively, while those in patients with normal vHIT were 1.04±0.21 and 1.13±0.12, respectively. The neural integrator time constant calculated from the mean slope of horizontal slow-phase velocity according to horizontal eye position was 42.9 s. The mean vertical eyeball deviation of patients with positive skew was 2.14±1.18° while uncovering the eye on the affected side, and -1.97±1.59° while uncovering the eye on the unaffected side. The median ABCD2 score of 14 patients was 2 (range, 1-3).ConclusionsHINTS findings were objectively measured in vertigo patients with spontaneous nystagmus. Although positive findings of HINTS have been recognized as a central sign, 54% (7/13) of cases with peripheral vestibulopathy showed positive HINTS signs. HINTS results should be interpreted carefully considering that a substantial proportion of peripheral vestibulopathy shows a positive HINTS sign.     

Differences in vestibulo-ocular reflex time constants in patients with vestibular migraine versus vestibular neuritis/labyrinthitis

ObjectiveRecurrent dizziness, vertigo, and imbalance, as well as nausea or vomiting, can be induced by central or peripheral vestibular pathology. Vestibular migraine (VM) is a central pathology in which migraines reciprocally interact with vestibular nuclei. Vestibular neuritis and labyrinthitis (VN/L) are peripheral diseases involving inflammation of structures in the vestibular nerve or labyrinth. Because VM and VN/L in early stages can produce similar symptoms, diagnosis may require prolonged clinical evaluation. It has been suggested that differences in a patient's Vestibulo-Ocular Reflex (VOR) measured during the rotary chair step rotation test (RCS Test) can differentiate VM from peripheral pathologies, allowing for faster diagnosis. We sought to compare VOR time constants (VORT_cs) in patients with VM versus VN/L, with the goal of exploring potential diagnostic value.Study designRetrospective chart review of patients seen at a hospital balance center between January 2010 and June 2019.SettingTertiary referral center.Patients68 patients (mean age = 58.15, 65 % female, 35 % male) were placed into two groups based on clinical diagnosis codes: 1) VM or 2) VN/L.Main outcome measure(s)Primary variable of VORT_c, evoked by rotational step testing.ResultsPatients in the VM group demonstrated statistically significant elevated VOR T_cs outside the normed range of 10–19.5 compared to those in the VN/L group (p = 0.0003) while patients in the VN/L group demonstrated statistically significant shortened VOR T_cs (p = 0.0443) with the two populations having distinctly different VOR T_c profiles.ConclusionsOur results support the conclusion that elevated VOR T_cs are a sign of central vestibular pathology and highlight the benefit of utilizing rotary chair testing early in the diagnostic process as a powerful diagnostic tool when evaluating dizzy patients for central versus peripheral vestibular dysfunction. Our results suggest more particularly that elevated VOR T_cs can be utilized to identify patients with vestibular migraine, thus offering differentiation from patients with peripheral vestibular dysfunction earlier in the process of diagnosis, with an opportunity for earlier intervention.     

Relation of video-head-impulse test and caloric irrigation: a study on the recovery in unilateral vestibular neuritis

The head-impulse test (HIT) is an important test for examining unilateral vestibular hypofunction. The new video-head-impulse test (vHIT) is more sensitive and specific than the clinical bedside-head-impulse test. Alternatively, one can test for vestibular hypofunction with the caloric irrigation test. Various studies have shown that both tests may not always identify vestibular hypofunction; instead, the results of the tests might be contradictory. To further explore the question, of whether vHIT and caloric irrigation test the same part of the angular horizontal vestibulo-ocular reflex (VOR), we examined patients with unilateral vestibular neuritis at different points in time. The tonic vestibular imbalance (e.g., subjective-visual-vertical, ocular torsion and spontaneous nystagmus) and dynamic dysfunction of VOR (vHIT and bithermal caloric irrigation) were measured and quantified. While parameters of the tonic vestibular imbalance were well described by single exponential decay functions, dynamic parameters were less well defined. Therefore, to better compare the time course of pairs of two different parameters, we used a linear regression analysis. No linear correlation was found in the group and individually for the gain asymmetry and the ipsilesional gain of the vHIT with the unilateral weakness of the bithermal caloric irrigation tests. Linear correlation was found for most parameters of tonic vestibular imbalance. These findings are further evidence that vHIT and caloric irrigation test different parts of the angular VOR.     

Auditory,video head impulse test and vestibular evoked myogenic potentials findings in adults with human immunodeficiency virus

ObjectivesEven though there is an association between hearing loss and human immunodeficiency virus (HIV), particularly in low- and middle-income countries, further research is needed to investigate the nature of such hearing loss. Likewise, despite documented vestibular alterations in people with HIV, the true occurrence, presentation, and nature of these manifestations are yet to be established. Advances in technology for vestibular testing has allowed for objective site-of-lesion tests such as the video head impulse test (vHIT), cervical vestibular evoked myogenic potentials (cVEMPs) and ocular vestibular evoked myogenic potential (oVEMPs). The current study aimed to compare and describe auditory, vHIT, cVEMPs and oVEMPs findings in adults with and without HIV.MethodsThe current study included an HIV positive group (n = 30) and an HIV negative group (n = 30) who underwent an auditory assessment (tympanometry and pure tone audiometry) and objective vestibular assessments.ResultsThe occurrence of hearing loss was 53.3% in the HIV positive group compared to 33.3% in the HIV negative group. A higher occurrence of vestibular involvement was documented in the HIV positive group (73.3%) compared to 13.3% in the HIV negative group.ConclusionAuditory assessment and objective measures of vestibular end-organ function (vHIT and VEMPs) can be useful to detect sub-clinical alterations. The equipment is mobile and can be performed in any health care setting such as infectious disease clinics for surveillance and monitoring purposes.     

Effect of different head impulse procedures on vestibulo-ocular reflex gain

Objectiveto study the effects on vestibulo-ocular reflex (VOR) gain using both video head impulse test (vHIT) and Suppression Head impulse test (SHIMP) either using the outward or the inwards head impulse.MethodsTwenty healthy subjects were enrolled in the study. They were examined using otometric vHIT and SHIMP test lateral plane using the lateral outwards head impulse ten impulses for each side and the inwards head impulse ten impulses for each side. The VOR gain resulting from the outwards versus inwards head impulse during the vHIT and SHIMP were statistically compared.ResultsTwenty healthy subjects, 10 Males and 10 females with a mean age 35 ± 11.7. Paired t- test showed no statistical significance difference in the mean VOR gain of right lateral semicircular canal (1.1 ± .12) using outwards versus (1.03 ± .22) inwards head impulses, nor for the left lateral semicircular canal mean VOR gain (1.1 ± .22) using outwards head impulse (1.1 ± .3) for inwards head impulse in vHIT. Paired t- test showed no statistical significance difference in the mean VOR gain of right lateral semicircular canal (0.96 ± 0.2)using outwards versus (1.04 ± 0.2) inwards head impulses, nor for the left lateral semicircular canal mean VOR gain (0.98 ± 0.25) using outwards head impulse (1.1 ± 0.28) for inwards head impulse in SHIMP test. No statistical significant difference was found between the VOR gain resulting from the right versus the left semicircular canal.ConclusionThe starting head position does not affect the VOR gain using both vHIT and SHIMP tests.     

Effects of endolymphatic space volume on discrepancy of results between caloric test and video head impulse test

ObjectiveThe caloric test (C-test) and video head impulse test (vHIT) are known to occasionally show contradictory results in patients with Meniere's disease (MD). The reasons underlying this discrepancy between the two tests are currently unclear. We aimed to reveal the mechanisms responsible for this discrepancy by performing volumetric evaluation of the endolymphatic space (ELS) by using endoluminal contrast-enhanced inner ear MRI (ieMRI).MethodsWe enrolled 136 patients (174 ears) who visited the vertigo/dizziness center of our university and underwent the C-test and vHIT between February 2018 and February 2020. Inner ear MRI was also performed to determine the presence of endolymphatic hydrops (EH). The percentage of patients diagnosed with each vestibular disease was as follows: MD, 23.0%; benign paroxysmal positional vertigo (BPPV), 17.8%; bilateral vestibular disorder (BVD), 9.2%; sudden deafness with vertigo (SD), 8.0%; peripheral dizziness (PD), 7.5%; unilateral vestibular disorder (UVD), 6.9%; vestibular neuritis (VN), 6.3%; delayed endolymphatic hydrops (DEH), 3.4%; central dizziness (CD), 2.9%; Hunt syndrome (Hunt), 1.2%; and other disorders (OD), 13.8%.ResultsAmong the ears in the present study, 46.0% (80/174) showed a discrepancy in the results of the C-test and vHIT, and the disease-related distribution of patients showing this discrepancy was as follows; MD, 38.8% (27/80; p = 0.0019); BVD, 13.8% (11/80); UVD, 12.5% (10/80); SD, 7.5% (6/80); BPPV, 6.3% (5/80); PD, 6.3% (5/80); VN, 3.8% (3/80); DEH, 3.8% (3/80); CD, 2.5% (2/80); Hunt, 0.0% (0/80); and OD, 10.0% (8/80). In all cases, the discrepancy presented as a positive C-test result and negative vHIT result. The ELS ratio was measured for the whole inner ear, cochlea, vestibule, and semicircular canal, and the relationships between the rates and the presence of discrepancy was examined. Inner ear ELS ratio was 17.9% ± 10.8% in patients with the discrepancy and 15.2% ± 8.8% in those without the discrepancy (p = 0.036). Cochlear ELS ratio was 14.9% ± 11.3% in patients with the discrepancy and 11.9% ± 10.3% in those without the discrepancy (p = 0.0012). Vestibular ELS ratio was 22.3% ± 16.2% in patients with the discrepancy and 17.2% ± 12.7% in those without the discrepancy (p = 0.032). Semicircular canal ELS ratio was 18.0% ± 11.0% in patients with the discrepancy and 16.5% ± 9.6% in those without the discrepancy (p = 0.442).ConclusionThe volume of the ELS may affect the discrepancy of results between the C-test and vHIT.     

Machine learning method intervention: Determine proper screening tests for vestibular disorders

ObjectiveTo evaluate the performance of different vestibular indicators in disease classification based on machine learning method.MethodsThis study use retrospective analysis of the vertigo outpatient database from a tertiary care general hospital. 1491 patients with definite clinical diagnoses were enrolled in this study. Spontaneous nystagmus, head-shaking nystagmus, positional nystagmus, unilateral weakness in caloric test, and gain and saccade in video head impulse test (vHIT) were recorded as variables. Diagnoses were mainly reorganized as acute vestibular syndrome, episodic vestibular syndrome, and chronic vestibular syndrome. The trained random forest model was applied based on exploratory data analysis results.ResultsRandom forest accuracies on acute, episodic, and chronic vestibular syndrome are 90%, 81.74%, and 91.3%, respectively. The most important features in acute vestibular syndrome are spontaneous nystagmus, and vHIT variables. In episodic vestibular syndrome, unilateral weakness in caloric test, gain and saccades on lateral semicircular canal are the top three parameters. Lateral vHIT gain, head-shaking nystagmus, and unilateral weakness in caloric test are the main parameters on chronic vestibular syndrome. In acute vestibular syndrome, spontaneous nystagmus and vHIT make major contributions in vestibular disorders distinction. When the disease course prolongation, unilateral weakness and head-shaking nystagmus become increasingly important.ConclusionFast clinical test sets including spontaneous nystagmus, head shaking nystagmus, and vHIT should be the first consideration in screening vestibular disorders.     

The evaluation of the use of isotretinoin on vestibular system by using vHIT

AimThe aim of the present study was to evaluate the effect of isotretinoin (ISO) on peripheral vestibular system using vHIT.Material and methodThis is a prospective study in which 30 patients administered ISO treatment with the diagnosis of acne vulgaris was evaluated. Following ear nose and throat, examination, audiological and vestibular evaluations were carried out. vHIT tests were conducted before and three months after the use of ISO (0.5–0.75 mg/kg/day). In addition, all participants underwent perceptual vertigo and dizziness tests before and three months after the use of ISO.ResultsIn vHIT evaluation of all patients, no overt saccade, covert saccade and spontaneous nystagmus finding was observed. Gain and asymmetry were compared before and after the use of ISO: No significant difference was found between lateral semicircular canal, anterior, and posterior semi-circular and symmetry measurements made before ISO use and those made three months after it (p = 1.00; p = 0.99; p = 0.66). Similarly, there was no significant difference in asymmetry values of vertical semicircular canals measured before ISO and three months after it (p = 0.90; p = 0.76). No statistically significant difference was found in vertigo, nausea and dizziness in terms of responses before and 3 months after ISO use (p = 0.063; p = 0.031; p = 0.063).ConclusionAlthough the studies demonstrating the effect of ISO on cochlea and symptoms occurring during treatment such as nausea, vomiting and vertigo suggest that it may exert effects on peripheral vestibular system, the present study indicates that it has no short terms effects on structures in peripheral vestibular system and vestibuloocular reflex pathways.     

Video head impulse test (vHIT) in migraine dizziness

Background and objective

Migraine is an extremely prevalent primary headache disorder that frequently associates parallel symptoms such as dizziness, tinnitus and hearing loss. Our aim is to investigate differences in video head impulse (vHIT) results with patients suffering from vestibular migraine (VM) and healthy people, taking into consideration mean values of vestibule ocular reflex (VOR) gain, occurrence of the compensatory saccades latency and amplitude. According to the results, determine the usefulness of vHIT in vestibular migraine diagnostics.