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.     

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.     

Importance of High-Frequency Vestibular Function in the Prognosis of Bilateral Vestibulopathy

ObjectivesThe aim of this study was to investigate whether preserved vestibular function in the high-frequency range influences the prognosis of patients with bilateral vestibulopathy (BVP) after vestibular rehabilitation.MethodsTwenty-four patients followed up with vestibular rehabilitation were recruited. The enrolled patients were divided into two groups according to the preservation of the high-frequency vestibulo-ocular reflex (VOR) based on the video head impulse test (vHIT). The results of computerized dynamic posturography and the Dizziness Handicap Inventory (DHI) survey collected at baseline and at the 6-month follow-up after vestibular rehabilitation therapy were analyzed.ResultsBoth groups showed significantly increased composite and DHI scores after follow-up with vestibular rehabilitation. The group with preserved high-frequency VOR showed a better composite score (P=0.064) and vestibular score (P= 0.008) than the group with lost high-frequency VOR at the 6-month follow up. The DHI score significantly decreased only in the group with lost high-frequency VOR (P=0.047). Among the three vestibular function tests (caloric test, rotary chair test, and vHIT) used to diagnose BVP, only vHIT showed a significant correlation (P=0.015) with a favorable prognosis (composite score ≥70).ConclusionBetter treatment outcomes are likely in patients with BVP with preserved vestibular function in response to high-frequency stimulation, as measured by the vHIT.     

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.     

Saccular Pathology Is Most Commonly Found in Patients With General Vestibular Disorders

ObjectivesThe first purpose of this study was to investigate the difference in the frequency of involvement of the superior vestibular nerve (SVN) and inferior vestibular nerve (IVN) territories in general vestibular disorders, and to identify which IVN territory was more commonly involved in patients with IVN lesions. The second purpose was to investigate the correlation of the degree of each saccular and posterior semicircular canal (PSCC) dysfunction, as represented by the parameters of cervical vestibular evoked myogenic potential (cVEMP) and video head impulse test (vHIT), in patients with pathology of the IVN territory.MethodsIn total, 346 patients with dizziness who underwent the caloric test, cVEMP, and vHIT were enrolled. Canal weakness in the caloric test, interaural amplitude difference (IAD) of cVEMP, and vestibulo-ocular reflex gain of the vestibulo-ocular reflex gain of the posterior semicircular canal (p-VOR) in vHIT were analyzed.ResultsAmong the enrolled patients, 15.6% had total vestibular nerve dysfunction, 14.5% had solely SVN dysfunction, and 29.5% had solely IVN dysfunction. Isolated saccular pathology was most common in patients with IVN pathology, followed by those with total IVN dysfunction and PSCC dysfunction. IAD and p-VOR were statistically well correlated, and the correlation was strongest in patients with both pathologic IAD and pathologic p-VOR (n=23, r=0.944), followed by patients with normal IAD and pathologic p-VOR (n=27, r=0.762) and patients with pathologic IAD and normal p-VOR (n=106, r=0.339).ConclusionAbnormal results were more common in vestibular tests investigating the IVN than in vestibular tests investigating the SVN in patients with general vestibular disorders. Isolated saccular pathology was more frequent than PSCC or combined pathology in patients with IVN dysfunction. Patients with abnormal p-VOR in vHIT had a higher probability of having both saccular and PSCC pathologies than patients with an abnormal IAD. This study describes the characteristics of vestibular-system subregions and provides guidance for clinically interpreting the combination of cVEMP and vHIT results.     

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.     

Discrepancies in the caloric testing and video Head Impulse Test results in a case with bilateral lateral semicircular canal malformations

Lateral semicircular canal (LSCC) malformations represent one of the most common types of inner ear malformation. As many cases of LSCC malformations are asymptomatic, detailed vestibular functions in such cases remain unclear. We present a case with bilateral LSCC malformations for whom the function of each vestibular organ was evaluated by caloric testing, video Head Impulse Test (vHIT) and vestibular evoked myogenic potentials (VEMP). Caloric testing showed canal paresis of the left side, whereas vHIT showed bilateral normal semicircular canal function. The results of VEMP indicated left saccular dysfunction. Discrepancies in caloric testing and vHIT results were observed and these discrepancies are thought to be due to endolymphatic hydrops rather than vestibular hypofunction, similar to that in Meniere disease.     

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.     

A possible objective test to detect benign paroxysmal positional vertigo. The role of the caloric and video-head impulse tests in the diagnosis

Background:Benign paroxysmal positional vertigo(BPPV)is characterized by vertigo lasting from seconds to minutes,induced by head movements.Objectives:Our study aimed to investigate the clinical significance of the caloric vestibular and video head-impulse tests(vHIT)diagnosing the disorder.Methods:68 patients suffering from posterior canal BPPV(25 male,43 females,mean age±SD,54.5±13.2 years)and 56 patients with a normal functioning vestibular system as control were investigated.Bithermal caloric test and vHIT was performed during the same medical check-up.Canal paresis(CP%),gain(GA)and asymmetry(GA%)parameters were calculated.Results:The Dix-Hallpike manoeuvre was only positive in 4%of this population.The CP%parameter was only pathologic in two patients,and there was no significant difference between control and BPPV patients(p=0.76).The GA value was never under 0.8 in this population,but GA%was abnormal in 63.2%.A significant difference comparing the GA%values to the control group was seen(p=0.034).There was no correlation detected between the CP%and GA%values in BPPV.Regarding the GA%value,61%sensitivity and 76%specificity was seen.Conclusion:The Dix-Hallpike manoeuvre was not often positive in the non-acute phase of BPPV;therefore,objective testing is essential.The caloric test does not have clinical significance in BPPV,but vHIT can be helpful based on the GA%parameter。     

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     

Influence of Canal Paresis and Compensation on Gain and Time Constant of Nystagmus Slow-phase Velocity to Yaw-axis Rotation

In order to assess the influence of canal paresis and compensation on the yaw-axis rotatory chair test parameters gain and time constant, a study was conducted in 435 patients diagnosed with unilateral peripheral vestibulopathy. Patients were grouped according to the amount of canal paresis found in the caloric test and by the result of a bedside examination of the vestibulo-ocular reflex (VOR). The time constant of the VOR diminishes as canal paresis increases and, when using a high-velocity sinusoidal test, there is a similar reduction in gain. Mean time constant was reduced when rotations were to the side of the lesion (ipsilesional) and to the normal (contralesional) and differences between both rotations were found for 21-80% canal paresis. Ipsilesional gain was significantly less than contralesional gain, which had a normal result independent of the amount of canal paresis; differences between them were significant when canal paresis was > 41%. Spontaneous nystagmus significantly influenced the appearance of asymmetries in gain and time constant in the tests performed while, with high-velocity sinusoidal rotation, gain was found to be significantly different for ipsilesional and contralesional rotations in non-acute symptomatic patients.     

Influence of canal paresis and compensation on gain and time constant of nystagmus slow-phase velocity to yaw-axis rotation.

In order to assess the influence of canal paresis and compensation on the yaw-axis rotatory chair test parameters gain and time constant, a study was conducted in 435 patients diagnosed with unilateral peripheral vestibulopathy. Patients were grouped according to the amount of canal paresis found in the caloric test and by the result of a bedside examination of the vestibulo-ocular reflex (VOR). The time constant of the VOR diminishes as canal paresis increases and, when using a high-velocity sinusoidal test, there is a similar reduction in gain. Mean time constant was reduced when rotations were to the side of the lesion (ipsilesional) and to the normal (contralesional) and differences between both rotations were found for 21-80%, canal paresis. Ipsilesional gain was significantly less than contralesional gain, which had a normal result independent of the amount of canal paresis; differences between them were significant when canal paresis was > 41%. Spontaneous nystagmus significantly influenced the appearance of asymmetries in gain and time constant in the tests performed while, with high-velocity sinusoidal rotation, gain was found to be significantly different for ipsilesional and contralesional rotations in non-acute symptomatic patients.     

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.     

Znaczenie testu Halmagyi i Curthoysa w standardowej diagnostyce otoneurologicznej chorych z zaburzeniami przedsionkowymi

The aim

This given work is dedicated to examine the correlation of results of the ambulant screening vHIT test conducted by applying ICS Impulse device, with results of standard appliance otoneurological videonystagmography (VNG) testing. Comparison of given results will provide assessment of vHIT test effectiveness for otoneurological diagnosis of patients suffering giddiness or any other equilibrium system disorder.

Reference and method

Diagnosis was reached with 20 patients suffering vestibular disorders with no specific ailment location. From overall VNG test there was a caloric testing extracted, containing assessment of canal paresis and directional preponderance. Numerical values of these parameters were compared to vHIT test result – the indicator of “gain” eye-ball movement imaging head move, to be specific.

Results

Conducted examinations did not reveal any significant correlation between VNG and vHIT parameters however it is need to be emphasized here, that most of the considered cases were not affected but any defect of vestibular canal receptor. Nevertheless, unsettled values of “gain” indicator may signify that vHIT regardless of ailments location is defected.

Conclusion

vHIT test with its quantitative analysis may in the future become indicator of auricular disorders.     

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.     

Acute vestibular asymmetry disorder: a new disease entity in acute vestibular syndrome?

Background: Acute vestibular syndrome (AVS) is characterized by the rapid onset of vertigo, nausea, vomiting and gait unsteadiness, which lasts for days.

Aims/objectives: We report cases as acute vestibular asymmetry disorder (AVAD), with presentations that mimic vestibular neuritis (VN) but without central lesions.

Materials and methods: We retrospectively reviewed records of patients presenting with acute spontaneous vertigo lasting more than 24?h from January 2011 to June 2016. Among 341 patients, five showed different findings that did not indicate either VN or stroke. We analyzed the clinical features and vestibular assessments of these patients.

Results: All five patients showed spontaneous nystagmus continuing for several days. However, head impulse tests (HITs) did not reveal a corrective saccade. Brain magnetic resonance imaging showed no abnormal lesions. The bithermal caloric test revealed directional preponderance without canal paresis. Finally, the slow harmonic test of the rotatory chair revealed unilateral high gain and phase within the normal range, but a significantly asymmetric response was observed. No patients showed recurrence during follow-up.

Conclusions and significance: Our study suggests that a normal HIT in AVS is not always a dangerous sign indicating an acute stroke. From our observations, we propose that AVAD would be a new disease entity within AVS.     

The semicircular canal function tests contribute to identifying unilateral idiopathic sudden sensorineural hearing loss with vertigo

BackgroundFew studies focused on the prognosis of unilateral idiopathic sudden sensorineural hearing loss (UISSNHL) with vertigo.ObjectivesTo describe how the semicircular canal (SCC) function tests may prove helpful in the diagnosis of UISSNHL with vertigo.Material and methods59 UISSNHL patients underwent audiometry, caloric test and video head impulse test (vHIT). The correlation between hearing loss and SCC dysfunction was analyzed.ResultsThe results showed significant differences of hearing loss grades (p = 0.004) and hearing loss configurations (p = 0.009) between UISSNHL patients with and without vertigo. In vHIT, the gains of horizontal canal (HC) and posterior canal (PC) were more frequently impaired compared with that of anterior canal (AC). The abnormal rate of caloric test was the highest, followed by the abnormal rates of HC and PC gain. A significant difference of abnormal rate of HC gain was only found between the mild and moderate UISSNHL patients with and without vertigo (p = 0.029).ConclusionAbnormal SCC function happens frequently in patients with profound hearing loss. Ipsilesional abnormal vHIT (especially the HC gain) in the presence of abnormal caloric test is a pattern of findings observed in mild and moderate UISSNHL patients with vertigo.     

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...     

Caloric and Search-Coil Head-Impulse Testing in Patients after Vestibular Neuritis

The objective of this study was to compare results of quantitative head-impulse testing using search coils with eye-movement responses to caloric irrigation in patients with unilateral vestibular hypofunction after vestibular neuritis. The study population consisted of an acute group (<3 days; N = 10; 5 male, 5 female; 26-89 years old) and a chronic group (>2 months; N = 14; 8 male, 6 female; 26-78 years old) of patients with unilateral vestibular hypofunction after vestibular neuritis. The testing battery included: (1) simultaneous measurement of eye and head rotations with search coils in a magnetic coil frame during passive Halmagyi-Curthoys head-impulse testing and (2) electronystagmography during bilateral monaural 44 degrees C-warm and 30 degrees C-cold caloric irrigation. The main outcome measures were (1) the gain of the horizontal vestibulo-ocular reflex during search-coil head-impulse testing and (2) the amount of canal paresis during caloric irrigation. All acute and chronic patients had a unilateral gain reduction during search-coil head-impulse testing. A pathological canal paresis factor was present in 100% of the acute patients but in only 64% of the chronic patients. The clinically suspected unilateral vestibular hypofunction resulting from vestibular neuritis was validated in all acute patients by both search-coil head-impulse and caloric testing. Hence, either of these tests is sufficient for diagnosis in the acute phase of vestibular neuritis. Chronic patients, however, were reliably identified only by search-coil head-impulse testing, which suggests that the low-frequency function of the labyrinths often becomes symmetrical, leading to a normal canal paresis factor.     

Implication of vibration induced nystagmus in Meniere's disease

CONCLUSION: The incidence of ipsilesional beating vibration induced nystagmus (VIN) is significantly higher in Meniere's disease (MD) with lower canal paresis (CP) group on caloric test and the intensity of VIN shows significant positive correlation with CP. Considering previous reports showing predominant loss of type II hair cells in MD and discrepancy of the results between caloric test and head thrust test in MD patients, VIN may provide valuable information regarding the functional reservoir of vestibular type II hair cells in MD. OBJECTIVES: Clinical presentation of MD is dynamic and nystagmus changes phase to phase, which is attributed to the recovery process in addition to central compensation after active vertigo attack of MD. VIN has been shown to reflect the side difference of peripheral vestibular excitability and is well correlated with the severity of caloric weakness in vestibular neuritis. Aim of this study was to compare the intensity and the direction of VIN with CP in unilateral MD. MATERIALS AND METHODS: 52 patients with unilateral definite MD on AAO-HNS guideline (1995) were included. Auditory and vestibular function tests including caloric test, post-head shaking nystagmus (HSN) and VIN were evaluated during symptom free period and cases with spontaneous nystagmus were excluded. Vibratory stimuli (100 Hz) were applied to either mastoid alternatively. Eye movement was recorded using video nystagmography system. The horizontal component of VIN was compared with HSN and caloric test. RESULTS: 37 patients (71%) showed VIN. VIN to ipsilesional side was in 10 and to contralesional side in 27. In patients with CP over 43% (N =23), 2 beated to ipsilesional side, 17 to contralesional side and 4 showed no VIN. In patients with CP of less than 43% (N =29), 8 beated to ipsilesional side, 10 to contralesional side and 11 showed no VIN (p<0.05). 33 patients (63%) showed HSN and 24 patients of them (72%) showed contralesional nystagmus. The intensity of VIN shows significant positive correlation with the degree of CP on caloric test (Spearman's rho =0.340, p<0.05).