[Diagnosis and therapy for horizontal semicircular canal cupulolithiasis]

By analysing the video-nystagmography findings of positional tests,to evaluate the therapeutic effect of the patients with horikontal semicircular canal cupulolithiasis (HSC-Cup).

A retrospective study of 36 patients with HSC-Cup. The induced nystagmus in roll tests was recorded by videonystagmography, whose direction, latency, intensity and time characteristics were analysed. All of the 36 patients were treated with lying position avoiding normal side and oral-taken betahistine mesilate tablets. A week later return visits and curative effects evaluation were made.

Horizontal apogeotropic nystagmus was induced by turning left or right in HSC-Cup roll tests. The time of latency and duration turning to normal and lesion side were(0. 93 ± 0. 65)s and(1. 01 ± 0. 78)s, (100.58 ± 36. 56)s and (118. 65 ± 143. 71)s, which showed no statistically significant difference (P>0. 05). The duration of nystagmus was more than 60 seconds. The intensity of nystagmus turning to normal and lesion side were(45.58 ± 28.71)°/s and (20.42 ± 16. 64)°/s. The intensity turning to normal side was greater than lesion side obviously. The difference was statistically significant (P<0. 05). Twenty-three patients withright HSC-Cup, and 13 patients with left HSC-Cup were taken in count. They were treated with above methods and return visit a week later. Twenty-eight patients (77. 77%) were cured, 36 patients (100. 00%) were improved. There were 4 patients recurrence during the follow-up.

The direction and duration time of induced nystagmus are available to diagnose the HSC-Cup. The lesion side may determined according to the intensity of induced nystagmus. Lying position avoiding normal side and oral-taken betahistine mesilate tablets is an effective treatment methods for HSC-Cup.