Effect of the canalith repositioning procedure on subjective visual horizontal in patients with posterior canal benign paroxysmal positional vertigo

Conclusion: Substantial numbers of patients with posterior canal benign paroxysmal positional vertigo (p-BPPV) have signs of utricular dysfunction at baseline. This improves after performing the canalith repositioning procedure. Objective: To evaluate the changes of subjective visual horizontal (SVH) in patients with p-BPPV before and after treatment with the canalith repositioning procedure. Methods: Twenty-six patients with p-BPPV were treated with the canalith repositioning procedure, Epley's maneuver, according to the affected side. Baseline SVH measurements were taken before performing the Dix-Hallpike maneuver and Epley's maneuver, for comparison with measurements taken just after Epley's maneuver, and 2 weeks after Epley's maneuver. Results: Among 26 patients with p-BPPV, 11 (42%) showed abnormal deviation of SVH at baseline. Just after performing Epley's maneuver, the number of patients who showed an abnormal deviation of SVH decreased significantly to 15% (4 of 26 patients; p < 0.05). Two weeks after performing Epley's maneuver, only two patients (8%) showed an abnormal deviation of SVH (p < 0.001).