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.     

Utility of quick oculomotor tests for screening the vestibular system in the subacute and chronic populations

Objective: The goal of this study was to determine the sensitivity and specificity of some widely used, easily administered clinical tests.

Background: Simple tests of oculomotor function have become widely used for clinical screening of patients suspected of having vestibular disorders despite a paucity of evidence showing good statistical support for their use in this highly variable population.

Methods: Healthy controls with no history of otologic or neurologic disorders (n?=?291) were compared to patients with known vestibular disorders (n?=?62). All subjects performed passive and active head shaking, un-instrumented head impulse tests (HT), and video head impulse tests (vHIT) recorded with infrared video-oculography.

Results: For both passive and active head shaking, using presence/absence of vertigo and of nystagmus, sensitivity was low (<0.40). Sensitivity of presence/absence of saccades on HT was even lower (<0.15). On vHIT, gains were all approximately?=?1.0, so sensitivity was very low (approximately 0.15–0.35). Sensitivity and specificity for presence/absence of saccades were moderately poor (less than 0.70).

Conclusion: None of these tests are adequate for screening patients in the out-patient clinic for vestibular disorders or for screening people in epidemiologic studies to determine the prevalence of vestibular disorders.     

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 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.

Vestibular function after vestibular neuritis

Abstract

Objective: To measure horizontal semicircular canal function over days, weeks, and months after an acute attack of vestibular neuritis. Design: The video head impulse test (vHIT) was used to measure the eye movement response to small unpredictable passive head turns at intervals after the attack. Study sample: Two patients diagnosed with acute right unilateral vestibular neuritis. Results: There was full restoration of horizontal canal function in one patient (A) as shown by the return of the slow phase eye velocity response to unpredictable head turns, while in the other patient (B) there was little or no recovery of horizontal canal function. Instead this second patient generated covert saccades during head turns. Conclusion: Despite the objective evidence of their very different recovery patterns, both patients reported, at the final test, being happy and feeling well recovered, even though in one of the patients there was clear absence of horizontal canal function. The results indicate covert saccades seem a successful way of compensating for loss of horizontal canal function after unilateral vestibular neuritis. Factors other than recovery of the slow phase eye velocity are significant for patient recovery.     

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.     

Changes of video head impulse test results in lateral semicircular canal plane by different peak head velocities in patients with vestibular neuritis

Background: The peak head velocity influences on the video head impulse test (vHIT) results, but it has been not known how much the difference is.

Aims: To evaluate the clinical evidence for the superiority of high-velocity compared to low-velocity vHIT.

Material and methods: vHIT was performed in 30 patients with vestibular neuritis using two peak head velocities (mean 80 vs. 240°/s). vHIT gains and parameters of corrective saccades (CSs) were compared. A vHIT gain of ≤0.8 or a peak CS velocity of ≥100°/s was considered pathologic.

Results: The vHIT gains were significantly lower (mean 0.5 vs. 0.6), and GA was larger (35 vs. 25%) at high-velocity vHIT, compared to low-velocity vHIT. CSs were significantly more frequent (100 vs. 80%) and peak CS velocities were larger (252 vs. 112°/s) at high-velocity vHIT. The abnormal rates based on vHIT gains were higher (90% vs. 73%) and CSs occurred more frequently (100% vs. 80%) at high-velocity vHIT. The abnormal rates based on the peak CS velocity were significantly higher at high-velocity vHIT (100% vs. 57%).

Conclusion: High-velocity vHIT is superior to low-velocity vHIT with a difference of 17–20% based on pathologic vHIT gains and presence of CSs.     

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.     

Video head impulse test relevance in the early postoperative period after cochlear implantation

Background: Cochlear implantation (CI) is the gold standard therapy for profound or severe sensorineural hearing loss. It is a safe surgical procedure but, because of the proximity of the cochlea and vestibule, postoperative vestibular disorder may occur. Our hypothesis is that the video head impulse test (vHIT) may be a good tool to achieve a topographic diagnosis of dizziness in the early postoperative period after CI.

Aims/Objectives: To evaluate patients with instability, imbalance and vertigo between 7 and 14 days after CI procedure.

Material and methods: A total of 31patients scheduled for unilateral CI were included in this study. vHIT for horizontal semicircular canal was performed before CI and between days 7 to 14 after the surgery.

Results: Six subjects had dizziness complaints after CI: instability (N?=?2), imbalance (N?=?2) and vertigo (N?=?2). The postoperative vHIT test turned abnormal only in subjects with vertigo as compared to the preoperative vHIT test results.

Conclusion and significance: vHIT is a good vestibular function test during the first 2 weeks after CI surgery when vertigo is the main complaint     

Diagnostic value of refixation saccades in the Video Head Impulse Test (vHIT) in unilateral definite Meniere’s disease

Abstract

Introduction: We currently interpret the video Head Impulse Test (vHIT) results mainly based on the gain value.

Aim: The purpose of this study is to evaluate vHIT results for both gain and re-fixation saccades on unilateral definite Meniere's disease (MD) subjects in comparison with normal healthy subjects.

Materials and Methods: Forty unilateral definite MD subjects and age-matched healthy subjects were recruited. Pure tone audiometry, the caloric test, and the vHIT test were performed on MD subjects. The vHIT test was performed on healthy subjects.

Results: The velocity regression gain (VRG) of the affected ear in patients with MD is significantly lower than of those in healthy subjects. The total percentage of refixation saccades is significantly higher in patients with MD when compared to healthy subjects. VRG values were not well-correlated with the percentage of refixation saccades. VRG asymmetry values are also not well-correlated with the percentage of unilateral canal weakness. A moderately stronger correlation between the percentage of refixation saccades and percentage of unilateral canal weakness, with an r² of 0.474.

Conclusions: The present study suggests that while VRGs are still a diagnostic parameter of detecting MD, the presence of refixation saccades can also have diagnostic value, especially with normal VRGs, in detecting MD.     

What does the dissociation between the results of video head impulse versus caloric testing reveal about the vestibular dysfunction in Ménière’s disease?

Conclusion: It is suggested that the different results of rotational (video head impulse – vHIT) and caloric tests in patients with Ménière’s disease (MD) may be a consequence of the physical enlargement of the membranous duct in the hydropic labyrinths in MD, causing a reduced response to caloric stimulation. Objectives: There have been reports that the results of two tests of semicircular canal function, the caloric response and the responses to vHIT do not agree. This retrospective study at a tertiary referral hospital examined this disagreement. Methods: This study reviewed the data of 22 patients who met the AAO-HNS criteria for MD and who had both caloric and vHIT testing. Results: There was a clear dissociation: patients with MD had a small or absent response to caloric stimulation of their affected ear, whilst their response to vHIT was in the normal range. Discussion: The accepted Gentine model of the mechanism of caloric stimulation could account for this dissociation: the increased diameter of the semicircular duct in hydropic labyrinths resulting in endolymph circulation within the duct itself and so a smaller thermally induced pressure across the cupula. The increased duct diameter will have little effect on responses to rotation.     

Assessment of the vestibuloocular reflex in fighter pilots with the video head impulse test

Conclusion: There were no changes in the function of the six semicircular canals in active fighter pilots, through the use of the video head impulse test (vHIT). These results suggest that the vestibuloocular reflex (VOR) works well at the high frequencies related to the natural head movements in this population. Objectives/hypothesis: The vestibular function in pilots has been reported as being different from that of other normal subjects. These differences are attributed to adaptation of the vestibuloocular reflex (VOR) or by habituation. These studies were conducted with caloric and/or rotatory tests and were limited to the lateral semicircular canals. The aim of the present study was to verify the occurrence of high frequency changes in the function of the six semicircular canals in active fighter pilots, through the use of the video head impulse test (vHIT). Study design: Cross-sectional design. Methods: The subjects participating in this study were divided in three groups, according to their flight experience. The control group (Group 1) consisted of 20 soldiers with no experience of in-flight training. For the test subjects 14 fighter pilots were selected and divided into two groups. Group 2 included the pilots with 1000–2000 hours of flight experience and Group 3 included pilots with 2001–3000 hours of flight experience. They were all submitted to a video head impulse test and the gains of the six semicircular canals were analysed. Results: There were significantly low gain values (p < 0,013) only in the left posterior semicircular canal in the control group as compared with the subject groups. However, there were no significant differences in gain values between the two groups of the active pilots.     

Comparative study between the caloric vestibular and the video-head impulse tests in unilateral Menière’s disease

Objective: Compare the caloric vestibular test (CVT) and the video head impulse test (vHIT) in the evaluation of Meniere’s disease (MD) and to analyze their diagnostic accuracy.

Materials and methods: Retrospective review of CVT and vHIT performed in MD patients at a tertiary care referral center in Spain.

Results: A total of 88 patients were reviewed. The CVT was abnormal in 67% (n?=?59) of patients, while the vHIT was abnormal in 66% (n?=?58) of them. Agreement between both tests was poor, regardless of whether the horizontal semicircular canal (SCC) or all SCC were analyzed (kappa?=?.21). Anterior SCC pathology was found in 30% (n?=?27) of the subjects while 51% (n?=?45) had altered gains in the posterior SCC.

Conclusions: Our study shows that patients with MD can have functional deficit involving the vertical semicircular canals, which cannot be detected by the CVT alone. Therefore, both tests should be used in a complementary fashion.     

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.     

Comparison of the video head impulse test results with caloric test in patients with Meniere’s disease and other vestibular disorders

Abstract

Background: The caloric test has been used to evaluate the semi-circular canal function for decades. In 2009, the video head impulse test (vHIT) was introduced, which can be used to evaluate the semi-circular canal function within a short time. Although both tests examine the semi-circular canal, the stimulation methods differ and it is unclear whether the vHIT is equivocal to the caloric test.

Aims/objectives: This study aimed to discern the differences between the vHIT and caloric test.

Material and methods: This study comprised 112 patients with vertigo who visited the vertigo/dizziness centre at our university hospital. Each of these patients underwent a caloric test and vHIT within the same day, and their results were compared. Additionally, an electrocochleography (EcoG) examination, glycerol test (G test), and MRI (performed 4?h after an intravenous gadolinium injection) were conducted to evaluate the influence of endolymphatic hydrops (EH) on the caloric test and vHIT results.

Results: Differences in the caloric test and vHIT results, among those with and without EH, were observed in 66.7 and 35.3% of patients, respectively.

Conclusions and significance: EH resulted in a difference in results between the caloric test and vHIT. Activated hair cell type may also be implicated.     

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.     

Saccades of video head impulse test in Meniere's disease and Vestibular Migraine:What can we learn from?

Background: Saccades are often observed on video head impulse tests(vHIT) in patients with Meniere’s Disease(MD) and Vestibular Migraine(VM). However, their saccadic features are not fully described.Objective: This study aims to identify the saccades characteristics of MD and VM.Methods: 75 VM patients and 103 definite unilateral MD patients were enrolled in this study. First raw saccades were exported and analyzed. The VM patients were divided into left and right based on their ears, while the ...     

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...     

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.     

Video head impulse test in bilateral vestibulopathy

IntroductionBilateral vestibulopathy is a rare chronic condition with multiple etiologies. Bilateral vestibulopathy is characterized mainly by unsteadiness when walking or standing, which worsens in darkness, as well as oscillopsia. The degree of handicap caused by bilateral vestibulopathy is variable and remains controversial.ObjectivesTo determine the value of the video Head Impulse Test in quantifying vestibular deficit and to establish its impact on the quality of life.MethodsTwenty patients (mean age, 41.9 years; range 14–80 years) fulfilling the recent Barany criteria of bilateral vestibulopathy, responded to the Situational Vertigo Questionnaire and underwent vestibular examination including fixation, positional tests, oculomotor test battery and video head impulse test.ResultsThe relation between each of the video head impulse test parameters and the scores from the questionnaire were statistically analyzed. We observed that patients with covert saccades on the video head impulse test were more likely to have a better quality of life than those with both covert and overt saccades, regardless of the vestibulo-ocular reflex gain in each semicircular canal. The presence of covert saccades was found to be associated with an improved quality of life regardless of the severity of vestibule ocular reflex-deficit. Our conclusion was that vestibule ocular reflex gain, measured by video head impulse test, does not quantify the severity of affection of quality of life in patients with bilateral vestibulopathy.ConclusionCovert saccades are strategies aiming at minimizing the blurring of vision during head movement, that is an adaptive mechanism that improves quality of life. Therefore, we recommend that video head impulse test should be a part of the routine diagnostic workup of bilateral vestibulopathy.