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

We investigated the incidence rates of cerebral palsy, severe mental and motor retardation, and Down syndrome in the City of Kokubunji in suburban Tokyo with a total population of about 100,000. The number of liveborn babies during 1985-1989 was 5,475. The number of children with cerebral palsy (CP) was 11 and the incidence rate was 2.01/1,000, which was equal to the rates in reports from several countries and was higher than those of the previous reports from Japan. Two out of 10 patients with CP had mild motor handicaps and were expected to "outgrow" their handicaps. The number of children with "severe mental and motor retardation" (SMMR) was 6 and the incidence rate was 1.10/1,000. Prenatal brain damage played a major role in the pathogenesis of CP and SMMR. The number of children with Down syndrome (DS) was 11 and the incidence rate was 2.01/1,000 which was higher than the previous rates. Incidence rates of CP, SMMR, and DS still remain high and further strategy to prevent pediatric neurological diseases is necessary.