[Infantile autism among children in the county of Nordland. Prevalence and etiology].

Few epidemiological studies of infantile autism have been conducted in Norway. A prevalence of four per 10,000 children was found in Nord-Trøndelag. Studies from Sweden, England and Japan show prevalence figures of 2-13 per 10,000. Causal factors of autism are complicated, but many studies in recent years indicate that both genetic and neurological factors are important. The aim of this study was to establish the prevalence of infantile autism in Nordland county and look for causal factors and disabilities among the children. Together with the Autism-Team we found 28 persons, born between 1975 and 1991, who lived in the county in 1992. This gives a prevalence of 5.5 per 10,000. 21 were boys, seven girls, 26 were mentally retarded, 13 had no verbal speech. Nine had epilepsy. 13 children were diagnosed before the age of four. Different diseases and impairments associated with autism were discovered in 19 children. In the case of eight children we found associated disease. When a diagnosis of infantile autism is made, the child should undergo a thorough medical and neurological examination. This should include CT brain scan, EEG, chromosome analysis, and screening for metabolic diseases and intrauterine virus infections. Sometimes examinations of liquor and auditory brain-stem responses are indicated.