A prospective comparative study of the aetiology of cerebral palsy and epilepsy in a one-year birth cohort from Northern Finland.

The one-year birth cohort from Northern Finland comprises 12 058 children, representing 96% of all live births in 1966 in the two northernmost provinces of Finland, Oulu and Lapland. Only 14 children, 1.2 per thousand, were lost during the follow-up to 14 years of age, in which data were collected prospectively on development, mortality and morbidity using questionnaires and registers. When all 47 children with cerebral palsy fulfilling the criteria of the Little Club of London (1959) were included, a prenatal risk factor was detected in 13 infants (27.7%) and a perinatal one in 25 children (53.2%), whereas 9 children (19.1%) represented an untraceable form of this disorder. There were 208 children with epilepsy, among which 18 (8.7%) had a prenatal risk factor, 38 (18.2%) a perinatal one, 33 (15.9%) a postnatal one, and 119 (57.2%) no identifiable risk factor. Among the 11 320 healthy children in the cohort alive at 14 years of age, there were 992 (8.8%) with risk factors for cerebral palsy and epilepsy. The relative risk attached to these aetiological factors was lower for epilepsy than for cerebral palsy.