Prognosis in Children With Febrile Seizures

Febrile seizures occurred in 3.5% of white and 4.2% of black children who were followed up in a large prospectively defined cohort. The frequency of adverse outcomes was examined in this population and risk factors were identified. Among 1,706 children with febrile seizures, no deaths or persistent motor deficits occurred as sequelae of seizures. Todd's paresis occurred in 0.4%. Risk factors identified for epilepsy after febrile seizures were family history of afebrile seizures, preexisting neurological abnormality, and complicated initial seizure. Of the 60% of children with febrile seizures who had none of these factors, 1% developed epilepsy by age 7 years. A single risk factor was present in 34%, of whom 2% developed epilepsy. Of the 6% with two or more of these factors, 10% developed epilepsy. After an initial brief febrile seizure, 1.4% experienced a subsequent attack which lasted 30 minutes or longer; none of these children had an afebrile seizure by the age of 7 years. Febrile seizures were associated with an increased risk of intellectual deficit only among children with preexisting neurological or developmental abnormality, and in those who developed subsequent afebrile seizures. A third of the children with febrile seizures had a recurrence, and 9% had three or more recurrences. The major predictor of recurrence was early age at onset.