[Evaluation of the vestibular ocular reflex in patients with unilateral peripheral vestibular disorder by the head impulse test].

OBJECTIVE:To evaluate the function of vestibular ocular reflex (VOR) in patients with unilateral peripheral vestibular disorder (uPVD) by the head impulse test (HIT). METHODS:The HIT and caloric test were carried out in 135 cases of patients with uPVD. The results of HIT were considered as normal (negative reaction) and abnormal (positive reaction). The results of vestibular function evaluated by caloric test were divided into three kinds, including normal, decreased and deficit according to the degree of canal paresis as less than 30 percent, from 30 to 99 percent, and equal to 100 percent, respectively. The sensitivity, specificity, positive and negative predictive value of HIT in assessing the vestibular function was analyzed. RESULTS:For the 135 patients with uPVD, the HIT was normal in 90 (66.7%) cases and abnormal in 45 (33.3%) cases. When the caloric test was normal, the HIT was normal or abnormal in 58 cases and 6 cases, respectively. And when the canal paresis was from 30 to 99 percent, the HIT was normal or abnormal in 28 and 24 cases, respectively. When the vestibular function was deficit (CP was 100%), the HIT was normal or abnormal in 4 cases and 15 cases, respectively. When the results of caloric test were considered as the standard method to evaluate the VOR, the sensitivity, specificity, positive and negative predictive value of HIT were 54.9%, 90.6%, 86.7%, and 64.4%, respectively. CONCLUSIONS:When assessing the function of VOR in patients with uPVD, the HIT could not replace the caloric test, but it can be a supplementary method. The information from both the HIT and caloric test can be combined to evaluate the patients with vestibular hypofunction comprehensively.