Clinical features of autistic children with setback course in their infancy.

This study examines the incidence rate of setback in 80 autistic children, the correlation between the type of onset and clinical features, developmental level and prognosis based on an originally developed questionnaire. Moreover, this study seeks to investigate the possibility that infantile autism might be classified into subgroups by the type of onset. 1) The acquired (including questionably acquired) group consisted of 39 cases (49%), while the natal group was made up of 41 cases (51%). 2) The age when the setback occurred was 21-22 months in the acquired group. 3) Precipitating psychological events were observed in 22 cases (56%) of the acquired group. 4) The mental developmental level including speech and socialbility function at 5 years of age was significantly lower in the acquired group than in the natal group. 5) The acquired group showed severe behavioral disorders such as "stereotypic behavior," "extremely hyperkinetic behavior" and "self-abusive behavior" compared with the natal group. 6) The adaptive levels at schools or institutions were lower in the acquired group than in the natal group. 7) There was a higher incidence of epileptic seizures or febrile convulsions in the acquired group than in the natal group. Moreover, there was a higher incidence of severe perinatal abnormalities in the acquired group. 8) The above-mentioned results suggest that infantile autism might be classified into two subgroups, acquired and natal groups, based on the type of onset, and also suggest that some types of brain dysfunctions are more severe in the acquired group than in the natal group.