Clinical features of 326 patients with benign paroxysmal positional vertigo

Objective To explore the clinical features and repositioning maneuver effects of benign paroxysmal positional vertigo (BPPV). Method The clinical features of 326 patients with BPPV from August 2009 to July 2011 were analyzed retrospectively. Different types of BPPV were compared. Results BPPV was more common in female and the peak period of onset was between the ages of 50 and 60. The average latency of vertigo attack was (1.52±1.22) s and 43 patients (13.2%) had no obvious latency. The median duration of vertigo attack was 10 s, with less than 60 s in 312 patients (95.7%) and between 60—180 s in 13 patients (4.0%). The latency of vertigo attack of posterior semicircular canal-BPPV(（1.74±1.21）s) was longer than that of horizontal semicircular canal-BPPV(（0.96±1.06） s, t=5.546，P<0.01）. But there were no differences in the gender, the course of disease and the duration of vertigo attack. The patients with posterior semicircular canal-cupulolithiasis were younger than those with posterior semicircular canal-canalithiasis. The duration of vertigo attack of posterior semicircular canal-cupulolithiasis was longer than that of posterior semicircular canal-canalithiasis. The latency and the duration of vertigo attack of horizontal semicircular canal-cupulolithiasis were longer than that of horizontal semicircular canal-canalithiasis and the age was older. Conclusions The posterior semicircular canal is more involved in BPPV. The latency of vertigo attack of posterior semicircular canal-BPPV is longer than that of horizontal semicircular canal-BPPV. The latency and the duration of vertigo attack of horizontal semicircular canal-cupulolithiasis are longer than that of horizontal semicircular canal-canalithiasis and the age is older. Key words: Vertigo; Vestibular diseases; Semicircular canals; Otolithic membrane