Abstract

Background
Benign positional vertigo (BPV) is characterized by episodic vertigo and nystagmus provoked by head motion. There have been major advances in the understanding of this common condition. We evaluated clinical features of large group of BPV patients in a multicenter study.
Methods
We analyzed clinical features of 1474 patients who had been diagnosed as having BPV in seven dizziness clinics in Korea. The diagnosis of BPV was based on the typical nystagmus concurrent with vertigo elicited by positioning maneuvers. According to the semicircular canal involved, we classified BPV into posterior, horizontal, and anterior canal types. The horizontal BPV was subdivided into geotropic and apogeotropic types according to the nystagmus elicited by head turning while lying down.
Results
The patients included 1002 women and 472 men. Mean age of the patients was 55.2 with no difference between women and men. Posterior (61.5%) and horizontal (32.0%) semicircular canals were most commonly involved. The Horizontal BPV was subdivided into 61.5% of geotropic and 31.5% of apogeotropic types. Most patients were idiopathic. Most of the patients (89.9%) were successfully treated with canalith repositioning procedure (CRP).
Conclusions
BPV may involve each of the three semicircular canals. The involved canal can be identified by careful observation of the nystagmus induced by Hallpike maneuver or head turning in supine position. The horizontal canal is more commonly involved than previously known. High success rate of CRP is expected only when different method of CRP is applied to each patient depending on the canal involved.