Incidence of idiopathic benign paroxysmal positional vertigo subtype by hospital visit type: experience of a single tertiary referral centre

To investigate the incidence of benign paroxysmal positional vertigo subtype by hospital visit type (i.e. out-patient department emergency room), in a single tertiary referral centre. A total of 772 consecutive patients with benign paroxysmal positional vertigo were included. Using head-roll and Dix-Hallpike tests, benign paroxysmal positional vertigo subtype was determined as canalolithiasis posterior semicircular canal benign paroxysmal positional vertigo, geotropic horizontal semicircular canal benign paroxysmal positional vertigo or apogeotropic benign paroxysmal positional vertigo. The posterior semicircular canal benign paroxysmal positional vertigo patients who were evaluated via the out-patient department outnumbered those evaluated via the emergency room, while those with horizontal semicircular canal benign paroxysmal positional vertigo who were evaluated via the emergency room outnumbered those evaluated via the out-patient department. A significantly higher proportion of patients who visited the emergency room had horizontal semicircular canal benign paroxysmal positional vertigo than posterior semicircular canal benign paroxysmal positional vertigo. These results suggest that the true incidence of horizontal semicircular canal benign paroxysmal positional vertigo might be higher than previously reported.