[Incidence rates of cerebral palsy, severe mental and motor retardation, and Down syndrome in the city of Higashiyamato in suburban Tokyo].

We investigated the incidence rates of three neurological diseases in childhood in the City of Higashiyamato in suburban Tokyo with a total population of about 70,000. The number of liveborn babies during 1985-1989 was 3,958. The number of patients with cerebral palsy (CP) was 9 and the incidence rate was 2.2/1,000, which was equal to the reports from several countries. Four out of 9 patients with CP had mild motor handicaps and were expected to "outgrow" their handicaps. The number of patients with "severe mental and motor retardation" (SMMR) was 4 and the incidence rate was 1.0/1,000. Prenatal brain damage played a major role in the pathogenesis of CP and SMMR. The number of patients with Down syndrome (DS) was 7 and the incidence rate was 1.8/1,000. Incidence rates of CP, SMMR, and DS still remain high and further strategy to prevent pediatric neurological diseases is necessary.