Benign paroxysmal positional vertigo simultaneously affecting several canals: a 46-patient series.

Although it is uncommon for benign paroxysmal positional vertigo (BPPV) to affect more than one canal simultaneously, it is not exceptional. We attempt to determine whether these patients present differences relative to "single-canal" cases. A prospective study was done in patients with BPPV, divided into three groups: single-canal BPPV, multi-canal BPPV in one ear and multi-canal BPPV in both ears. Diagnosis was by Dix and Hallpike, supine roll and cephalic hyperextension tests. Treatment was according to the affected canals, by Semont, Epley, Lempert and Yacovino manoeuvres. Aetiology, sex, age, response to treatment, recurrence and final status in each of the three groups was evaluated. Five hundred and eighty-three patients were diagnosed with BPPV: 537 single-canal (92 %) and 46 multi-canal (8 %); of the latter, 36 bilateral and 10 unilateral cases. Basic differences between groups were: greater percentage of idiopathic cases in single-canal (p < 0.0001, Chi-square), greater percentage of post-traumatic cases in bilateral multi-canals (p = 0.006, Chi-square) and prior history of BPPV was more common in unilateral multi-canal (p = 0.006, Chi-square). No differences between groups in response to treatment, recurrence and final status were detected. There are aetiological differences between patients with single-canal BPPV, unilateral multi-canal BPPV and bilateral multi-canal BPPV. Response to therapeutic manoeuvres, however, shows that over 90 % of the patients in all the groups are cured.