Risk of seizure recurrence after early withdrawal of antiepileptic treatment in the neonatal period

Abstract

Recent data indicate that a majority of neonatal seizures arc subclinical and therefore only possible to diagnose with EEG or continuous EEG-monitoring. We estimated the risk of seizure recurrence after neonatal seizures diagnosed with a combination of clinical signs, EEG and continuous amplitude-integrated EEG-monitoring (Cerebral Function Monitoring, CFM). Patients and Methods: During a two-year period (1990-1991) 1283 patients were treated in our NICU. Among these infants 58 (4%) had a seizure diagnose. Antiepileptic treatment (AET) aimed to be as short as possible. Follow-up was made in surviving infants at an age of 12-24 months. Results: Thirtyone of the infants with seizures were full-term babies and 26 preterm (GA 26-36 w). The initial moratlity was 38% (21/58), 54% in the preterm infants vs 19% in the fullterm babies. Among the 36 surviving infants available for follow-up AET was discontinued in 34. Two infants with abundants seizures in combination with multifocal epileptiform activity on the initial EEG's continued AET, one had recurrence of seizures. In 3 fullterm infants with <10 seizures no AEt was given, none of these infants had later recurrence of seizures. Twentynine infants were treated for 1-65 days (median 4.5 days). Three infants (9%) had recurrence of seizures at 6-22 months of age, all had > 10 neonatal seizures. The presence of structural changes in the brain (diagnosed with CT, MRT or US) did not increase the risk of seizure recurrence in the full-term infants (10%) recurrence vs 15% in infants with no changes). Among the preterm infants most of the babies with structural chages died of IVII. We conclude that the risk of seizure recurrence within the first year of life after neonatal seizures is low. With close clinical and EEG follow up most AET can be discontinued when the baby is still in the NICU.