Comparison of the video head impulse test (VTIT), caloric test, spontaneous nystagmus and cervical vemp results in the assesment of peripheral system disorders

Video head impulse test (vHIT) is commonly used for the evaluation of vestibular system disorders because it can be performed easily in a short period of time and gives information about all of the semicircular channels. However, studies regarding the sensitivity, specifity and correlation of vHIT with the other tests that are used for assessment of vestibular system are limited in the literature. It is not clear whether vHIT is an alternative to the caloric test or not. The aim of this study is to investigate the sensitivity and specifity of vHIT and to find out the correlation between vHIT and other vestibular tests such as caloric test, spontan nystagmus, post-head shaking nystagmus and cervical vestibular evoked myogenic potentials (VEMP). This study was designed as a prospective, blinded study. The patients who applied to the Neurotology Clinic of the Baskent University Otolaryngology Department between the years of 2015-2016 constituted for the study population. Patients in whom vHIT, pure tone audiometry, cervical VEMP, spontaneous nystagmus, post-head shaking test and caloric test were performed and that were diagnosed as BPPV, Meniere's disease, vestibular neuritis, vestibular migraine, vestibular schwannoma and chronic vestibulopathy were enrolled. The audiovestibular tests were performed by two experienced audiometrists and were evaluated by two experienced neurootologists who were blinded to the nature of patients. The data has been examined and sensitivity, specificity, positive predictive value, negative predictive value and power of the vHIT were calculated. A total of 88 patients were enrolled to the study. Thirty-one patients were diagnosed as Meniere's disease, 25 patients were diagnosed as vestibular neuritis, 11 patients were diagnosed as vestibular migrain, 11 patients were diagnosed as chronic vestibulopathy, 8 patients were diagnosed as BPPV and 2 patients were diagnosed as vestibular schwannoma. Overall sensitivity and specifity of lateral vHIT for vestibular disease, i.e. when specific diagnosis was not considered, was 74.6% and 53.65%, respectively. The diagnosis specific sensitivity and specifity was 87.5%, and 42.85% for Meniere's disease and 60% and 53.3% for vestibular neuritis. 81.8% of the patients (72/88) had pathological vHIT while 54.5% had canal paresia, 60.2% had pathological cVEMP, 23.9% had spontaneous nystagmus and 72.7% had post-head shaking nystagmus. Pathological lateral vHIT was deteremined in 74.5% of patients who had canal paresis in caloric test and pathological lateral vHIT was determined in 46.3% of patients who had normal caloric test results (p<0.05). Pathological posterior vHIT was determined in 44.7% of patients who had canal paresis in caloric test and pathological posterior vHIT was determined in 65.9% of patients who had normal caloric test results (p<0.05). Pathological lateral vHIT was determined in 42.9% of patients who had spontaneous nystagmus and pathological lateral vHIT was determined in 67.2% of patients who had not spontaneous nystagmus (p<0.05). There was no statistically significant correlation between vHIT and the caloric test, post-head shaking test, spontan nystagmus and cervical VEMP. Our results show that vHIT determines unilateral vestibular hypofunction with high.accuracy. Therefore, if vHIT results are patological and compatible with the results of other audiovestibular tests, caloric test may not be performed. If vHIT results are normal or pathological results are not compatible with the results of other audiovestibular tests, caloric test should be performed.