Cumulative Incidence of Seizures and Epilepsy in Ten-Year-Old Children Born Before 28 Weeks' Gestation.

OBJECTIVE

We evaluated the incidence of seizures and epilepsy in the first decade of life among children born extremely premature (less than 28 weeks' gestation).

METHOD

In a prospective, multicenter, observational study, 889 of 966 eligible children born in 2002 to 2004 were evaluated at two and ten years for neurological morbidity. Complementing questionnaire data to determine a history of seizures, all caregivers were interviewed retrospectively for postneonatal seizures using a validated seizure screen followed by a structured clinical interview by a pediatric epileptologist. A second pediatric epileptologist established an independent diagnosis based on recorded responses of the interview. A third epileptologist determined the final diagnosis when evaluators disagreed (3%). Life table survival methods were used to estimate seizure incidence through ten years.

RESULTS

By age ten years, 12.2% (95% confidence interval: 9.8, 14.5) of children had experienced one or more seizures, 7.6% (95% confidence interval: 5.7, 9.5) had epilepsy, 3.2% had seizure with fever, and 1.3% had a single, unprovoked seizure. The seizure incidence increased with decreasing gestational age. In more than 75% of children with seizures, onset was after one year of age. Seizure incidence was comparable in both sexes. Two-thirds of those with epilepsy had other neurological disorders. One third of children with epilepsy were not recorded on the medical history questionnaire.

SIGNIFICANCE

The incidence of epilepsy through age ten years among children born extremely premature is approximately 7- to 14-fold higher than the 0.5% to 1% lifetime incidence reported in the general pediatric population. Seizures in this population are under-recognized, and possibly underdiagnosed, by parents and providers.