Forty cases of benign paroxysmal positional vertigo (BPPV) were reported. The most predominat age of the patients was the fourth decade, followed by the third and fifth decases. There were very few patients younger than 30.
Ninty percent of the BPPV patients noted their critical position themselves, which is useful for the diagnosis of BPPV.
Spontanous nystagmus was not seen in any of the patients. Characteristic nystagmus was seen in positional nystagmus and/or positioning nystagmus under the critical position. Vertigo and nystagmus disappeared in 62 Oo of the cases within 4 weeks and 26% within 1 - 2 months, in 12 % vertigo persisted more than 2 months and they presented unilateral reduced caloric responses relatively often.
One of them was treated by physiotherapy with precipitating head positions on a repeated and serial basis. The characteristic nystagmus of BPPV was sometimes found in patients suffering from sudden deafness, Meniere's disease, head injuries and so on.
We supposed that the pathogenesis of BPPV might be concerned with not only otoliths but also semicircular canals.
