Increased number of febrile seizures in children born very preterm: relation of neonatal, febrile and epileptic seizures and neurological dysfunction to seizure outcome at 16 years of age

Abstract

Purpose: In prematurely born population, a cascade of events from initial injury in the developing brain to morbidity may be followed. The aim of our study was to assess seizures in prematurely born children from birth up to 16 years and to evaluate the contribution of different seizures, and of neurological dysfunction to the seizure outcome.

Methods: Pre- and neonatal data and data from neurodevelopmental examination at 5 years of 60 prospectively followed children born at or before 32 weeks of gestation, and of 60 matched term controls from the 2 year birth cohort were available from earlier phases of the study. Later seizure data were obtained from questionnaires at 5, 9, and 16 years, and from hospital records and parent interviews.

Results: In the preterm group, 16 children (27%) exhibited neonatal seizures, 10 children (17%) had seizures during febrile illness and 5 children had epilepsy. Eight children had only febrile seizures, and 3 of these had both multiple simple and complex febrile seizures and neurodevelopmental dysfunction. None of the 8 children had experienced neonatal seizures, 6 had a positive family history of seizures, but none developed epilepsy. The children with epilepsy had CP and neurocognitive problems, and all but one had experienced neonatal seizures; two of them had also had fever-induced epileptic seizures. In controls 3 children (5%) had simple febrile seizures.

Conclusion: Children born very preterm have increased rate of febrile seizures compared to the controls. However, no cascade from initial injury via febrile seizures to epilepsy could be shown during the follow-up of 16 years. Symptomatic epilepsy in prematurely born children is characterised by neonatal seizures, major neurological disabilities and early onset of epilepsy.