Age at onset of seizures in young children.

Age at onset of seizures in young children and its relationship to factors such as prior neurological status and neurological outcome were examined. Of 52,360 children, 39,270 of whom were followed for the full 7 years, a total of 2,635 experienced one or more seizures between birth and 7 years of age. The incidence of nonfebrile convulsions was highest in the first year of life, especially in the first month. Children with neonatal seizures who later developed nonfebrile seizures did so early, two-thirds by 6 months and three-quarters by 1 year of age. Children with neurological or developmental abnormality assessed in the first year of life did not have their first seizure earlier than children without abnormality. Neurological abnormality in the first year of life before any seizure, and the presence of minor motor seizures, were associated with an increased rate of mental retardation and cerebral palsy at age 7, but early age at onset appeared to have little prognostic value regarding intellectual function, cerebral palsy, and epilepsy.