An Epidemiological Study on Peripheral Vestibular Disorders in Toyama Prefecture (2nd Report)

After the last Survey of Meniere's disease and sudden deafness in Toyama Prefecture, 187 new cases of Meniere's disease and 131 new cases of sudden deafness were diagnosed by the same 779 members or clinics of the Toyama Medical Association in 1985 and listed in the intractable disease category. The following characteristics on epidemiological and clinical features of Meniere's disease and sudden deafness were noted in Toyama Prefecture: 1) Prevalence: The prevalence of Meniere's disease was 17.5 per 100,000 population as registered by the Members of Toyama Medical Association in 1974, 1979, 1982 and in 1985. The prevalence of sudden deafness was 7.2 per 100,000 population as registered by Members of Toyama Medical Association in 1973, 1978 and in 1985. 2) Sex-ratio: The male/female ratio in patients with Meniere's disease was 213/560. There were 117 males and 121 females in sudden deafness. 3) Age distribution: The peak of age distribution was located in 50–59 years for males and 60–69 years for females in Meniere's disease. The peak of sudden deafness for males was in the fourth decade, while for females in the fifth decade. 4) Geographical distribution: The number of patients with Meniere's disease was higher in Toyama city and the neighboring areas where urbanization is in progress. There were more patients in Toyama city, Takaoka city and Ohsawano area in sudden deafness. This study shows that certain epidemiological characteristics of Meniere's disease are different from those of sudden deafness.