A population based, controlled follow-up study of the general outcome of 73 children followed for 2 to 12 years after the acute phase of childhood encephalitis is reported from the University of Oulu, Finland. Varicella accounted for 23% of cases, mumps 11%, herpes simplex 8%, measles 5%, and the etiology was unknown for 44%. The mean age at onset was 5.9 years (range 5 days to 14 years). The 61 school-age children had lower performance and full-scale IQs than their randomly selected, age- and sex-matched controls. Visual acuity was more often reduced and EEG and ENG abnormalities were more frequent. A poor prognosis was infrequent, the incidence being 3.5 per million children at risk annually. Dysarthria was the most frequent sequel of HSV encephalitis. Ataxia, seen most commonly with varicella encephalitis in the acute phase, persisted in only 1 of 17 children at follow-up examination. The prognosis for childhood encephalitis in this study is much better than anticipated on the basis of earlier follow-up studies that included a greater number of HSV cases. 
COMMENT. A case of severe macrocephaly and brain damage is reported in association with second trimester congenital varicella infection from the Departments of Neurology and Clinical Genetics, The Hospital for Sick Children, Great Ormond Street, London, England.