Long-Term Changes in Video Head Impulse and Caloric Tests in Patients with Unilateral Vestibular Neuritis

Abstract

Background and Objectives Video head impulse tests (vHITs) and caloric tests are widely used to assess the loss of vestibular function in acute vestibular neuritis. Although previous studies have reported on the results of each test, longitudinal comparison of these tests is rare. In the present study, vHITs and caloric tests were performed in patients with unilateral vestibular neuritis during the acute phase and after a long follow-up period (＞6 months). The goal of this study was to evaluate the changes in vHIT and caloric test results and to analyze the relationships between them. Subjects and Method Between September 2013 and December 2015, charts from 13 patients with unilateral vestibular neuritis were retrospectively reviewed. Among the 13 patients, caloric tests and vHITs were performed in 9 and 10 patients, respectively. Results of the vHITs and caloric tests were analyzed and the changes were compared. Results During the acute phase of vestibular neuritis, the results of the caloric test showed an increase in canal paresis (CP), and the results of the vHIT showed a decrease in horizontal gain. Although subjective symptoms improved in all patients after a long follow-up period (mean: 13.9 months), the occurrence of CP determined from the caloric test was not significantly changed (p=0.889). On the other hand, the mean horizontal gain of the vHIT had improved significantly (p＜0.05). Conclusion While CP determined from the caloric test did not change after a long follow-up period, the decreased horizontal gain in the vHIT was significantly recovered in patients with unilateral vestibular neuritis.