Central pathway abnormalities related to the utricle in benign paroxysmal positional vertigo

Abstract

Introduction: Otoconia in the semicircular canals, detached from the otolithic organs, could be the cause of benign paroxysmal positional vertigo (BPPV). Methods of evaluating the utricle include subjective visual vertical (SVV) and the ocular vestibular evoked myogenic potential (oVEMP). Objectives: To evaluate SVV and oVEMP in patients with BPPV, before and after the repositioning maneuver (MRP). Materials and Methods: Prospective, case-control study. Patients with BPPV (posterior semicircular canal) and age- and sex-matched controls were recruited. SVV and oVEMP were performed. MRP was executed and SVV and oVEMP were repeated immediately and after one week. The level of disability was assessed using the Dizziness Handicap Inventory (DHI) scale and the level of dizziness using the visual analog scale (VAS); both were performed pre- and post-MRP. Results: Thirteen patients completed the study (average age 48.8 years, 53.8% were women). The DHI and VAS scores decreased post-MRP. 53.8% showed alteration in SVV, with 71.4% showing greater deviation towards the contralateral side of BPPV. One week post-MRP, 4/13 still presented deviation, but to a lesser extent and unilaterally. A positive correlation was observed between SVV and DHI. All patients showed a bilateral response in oVEMP, with 4/13 initially showing asymmetry, but none after treatment. No correlation was observed between oVEMP and DHI or VAS. Conclusions: Although alterations in SVV and oVEMP were evident in patients with BPPV, few patients had alteration in both exams. There is a moderate correlation between SVV and DHI, and SVV with VAS, but not with oVEMP.