Analyses with the Video Head Impulse Test During the Canalith Repositioning Maneuver in Patients with Isolated Posterior Semicircular Canal Benign Paroxysmal Positional Vertigo

Objective: To evaluate the posterior semicircular canal (PSCC) functions using video head impulse test (vHIT) during canalith repositioning maneuver (CRM) treatment in patients with isolated, posterior semicircular canal benign paroxysmal positional vertigo (PSCC-BPPV). Methods: A total of 44 subjects comprising of 24 subjects with isolated PSCC-BPPV and 20 age-and sex-matched healthy control subjects were enrolled in the present study. vHIT was performed for the affected PSCC before and just after CRM and at the third and seventh day and first month to evaluate vestibulo-ocular reflex (VOR) gain, gain asymmetry (GA), and corrective saccades. Repeated determinations of VOR gain and GA were compared to evaluate the time course of vHIT measurements during CRM treatment in isolated PSCC-BPPV patients, and the values were also compared with the control group. Results: VOR gains and GA values were not statistically different before and after CRM and at the third-day, seventh-day and first-month visits for the affected PSCC. Moreover, values did not differ between the BPPV and control groups, and none of the subjects demonstrated corrective saccades. Conclusion: To our knowledge, this study is the first report to investigate vHIT measurements with a time course of alterations during CRM treatment in PSCC-BPPV patients. vHIT may not provide an additional contribution for evaluating vestibular dysfunction during the diagnosis and treatment of isolated PSCC-BPPV.