Vestibular neuronitis: epidemiological survey by questionnaire in Japan.

An epidemiological survey on vestibular neuronitis in Japan was conducted by means of a questionnaire filled in by major neuro-otology clinics (otolaryngologists) during 1988-1990 (3 years). The diagnostic criteria of vestibular neuronitis settled on in 1986 by the Standardization Committee of the Japan Society of Equilibrium Research were applied. Gross analysis of questionnaire answers showed that i) there was no sexual difference, ii) the peak of age distribution was between 40-50 years, iii) about 30% of all cases had had common colds prior to the disease, the rate being highest among children below 10 years, iv) disappearance of positional and positioning nystagmus appeared in about 60% of all cases within 3 months, and that v) caloric CP was observed in about half of the cases at the follow-up test. Progress was not as favorable when compared to previous studies.