Assessment of the utricular function in posterior canal benign paroxysmal positional vertigo patients before and after canalith repositioning maneuvre and its relation to residual dizziness

Abstract

Background: In benign paroxysmal positional vertigo (BPPV), the otoconia are dislodged from their usual position within the utricle and migrated into one of the semicircular canals. Utricular dysfunction in BPPV has been reported. Residual dizziness (RD) is common after the treatment. Objective: To assess the utricular function in patients with posterior canal BPPV after canalith repositioning maneuver (CRM) using ocular vestibular evoked myogenic potential (oVEMP) and to correlate the findings with any RD after CRM. Methods: Thirty adult patients with posterior canal BPPV (6 males and 24 females) were compared to well-matched controls. The oVEMP and Dizziness Handicap Inventory (DHI) Questionnaire were administrated before and after successful CRM. Results: Before CRM, the affected ear showed a significant delay in latency of N1 in the affected ear oVEMP and a significantly decreased in N1–P1 amplitude compared to controls and to the non-affected ears. After CRM their amplitudes were comparable. The BPPV group had a greater interaural amplitude difference percent (IAAD%) compared to controls before and after CRM. The non-affected ear showed only decrease in N1–P1 amplitude compared to controls. After CRM the affected ear amplitude increased and became comparable to the controls. The IAAD% was larger in RD group than non-RD group before and after CRM. The dizziness handicap severity decreased after CRM. But the occurrence of RD could not be predicted from DHI scores. Conclusion: Utricular function measured by oVEMP in the affected ear improved after CRM, and contralateral ear showed sub-clinical affection. Persistent VEMP abnormality reflecting persistent utricular dysfunction was related to residual dizziness.