Relationship between vestibulo-ocular reflex gain and dizziness handicap inventory score to predict effectiveness of vestibular rehabilitation

Abstract

Background and Aim: Evaluating the effective­ness of vestibular rehabilitation (VR) in patients with vestibular lesions has always been a challe­nge. The questionnaires that are used for this pur­pose mostly show the degree of vestibular dis­ability rather than providing information about improvement of vestibular dysfunction. This study aimed to evaluate whether video head imp­ulse test (vHIT) that is used for the examination of vestibulo-ocular reflex (VOR), is a useful method for predicting the effectiveness of VR and has a correlation with dizziness handicap inventory (DHI) score. Methods: Participants were 42 patients with unilateral peripheral vestibular hypofunction (UPVH) undergoing VR. Patients were assessed before and after rehabilitation by the vHIT in all ipsilesional and contralesional semicircular can­als (SCCs) and the DHI. The changes in DHI score and VOR gain before and after rehabili­tation, were shown as ΔDHI and ΔVOR and their correlation was evaluated. Results: VOR gain from ipsilesional and contra­lesional SCCs was improved significantly after VR. There was a significant strong negative correlation between ΔVOR gain from ipsile­sional SCCs and ΔDHI score but no significant correlation was found between the ΔDHI score and ΔVOR gain from contralesional SCCs. Conclusion: vHIT test is a useful tool to evaluate the effectiveness of VR. VOR gain is correlated with the DHI score. Therefore, the improvement in vHIT results in all three SCCs after VR may be a good predictor of the degree of improvement in dizziness-related disability. Keywords: Vestibular rehabilitation; follow-up; unilateral vestibular hypofunction; video head impulse test; dizziness handicap inventory