[Clinical features of multiple canal involvement in benign paroxysmal positional vertigo]

To describe a series of patients with multiple canal involvement in benign paroxysmal positional vertigo (BPPV), with respect to diagnosis and management.

Ninety-five individuals with symptoms of BPPV and positional nystagmus were included in this study. The diagnosis was based on a history of brief episodes of vertigo and the presence of multiple positional nystagmus as confirmed by video-oculographic examination. Patients were treated by means of different particle repositioning manoeuvres according to the affected canal.

Ninety-five patients showed multiple positional nystagmus during the examination corresponding to simultaneous multi-canal BPPV. Fourteen patients (14.7%) had bilateral canal BPPV. Six patients had bilateral posterior canal. Six patients had bilateral horizontal canal, and two patients had bilateral anterior canal. Fifty-three patients (55.8%) had torsional, up-beating nystagmus with down-beating nystagmus, which suggested possible affected both of posterior and anterior canals. Twenty patients (21.1%) had torsional up-beating nystagmus and horizontal direction nystagmus, which suggested possible affected both of posterior and horizontal canals. Five patients had down-beating nystagmus with horizontal nystagmus, which suggested affected both of anterior and horizontal canals. Three patients had torsional up-beating with down-beating and horizontal nystagmus, which suggested possible affected multiple canals. Treatment given to the patients varied according to the canal affected, started with the canal that elicited a strong positional nystagmus and vertigo, and 93.7% (89/95) of patients were symptom free or improved.

It has been found that multi-canal BPPV is not a rate observation in clinic, and most of them affected posterior and anterior canals. Treatment of multi-canal BPPV can be effective using repositioning maneuver.