Analysis of non-posterior canal benign paroxysmal positional vertigo in patients treated using the particle repositioning chair: A large, single-institution series

Purpose: Benign paroxysmal positional vertigo (BPPV) involving the horizontal and superior semicircular canals is difficult to study due to variability in diagnosis. We aim to compare disease, treatment, and outcome characteristics between patients with BPPV of non-posterior semicircular canals (NP-BPPV) and BPPV involving the posterior canal only (P-BPPV) using the particle repositioning chair as a diagnostic and therapeutic tool. Methods: Retrospective review of patients diagnosed with and treated for BPPV at a high volume otology institution using the particle repositioning chair. Results: A total of 610 patients with BPPV were identified, 19.0% of whom had NP-BPPV. Patients with NP-BPPV were more likely to have bilateral BPPV (52.6% vs. 27.6%, p < 0.0005) and Meniere's disease (12.1% vs. 5.9%, p = 0.02) and were more likely to have caloric weakness (40.3% vs. 24.3%, p = 0.01). Patients with NP-BPPV required more treatments for BPPV (average 3.4 vs. 2.4, p = 0.01) but did not have a significantly different rate of resolution, rate of recurrence, or time to resolution or recurrence than patients with posterior canal BPPV. Conclusions: Comparison of NP-BPPV and P-BPPV is presented with reliable diagnosis by the particle repositioning chair. NP-BPPV affects 19% of patients with BPPV, and these patients are more likely to have bilateral BPPV and to require more treatment visits but have similar outcomes to those with P-BPPV. NP-BPPV is common and should be part of the differential diagnosis for patients presenting with positional vertigo.