Abstracts

Rationale: The purpose of this study is to investigate the utility of any EEG (early or late) in children with first complex febrile seizure (CFS), in predicting the occurrence of subsequent unprovoked seizure/epilepsy. Methods: A retrospective chart review of patients seen in the BCH ER between 2002- 2008 was conducted to identify all children who were seen in the ER after first complex febrile seizure (focal, prolonged>10 min, multiple within 24 hour period), and had EEG within 4 months. Only patients with a minimum follow-up of 2 years were included. Children with known severe neurologic disability and patients with history of unprovoked seizure at baseline were excluded. The ability of an abnormal EEG to predict epilepsy and/or an unprovoked seizure was examined using univariate logistic regression.Results: Eighty five patients (49 male-58.3%), with first CFS who had an EEG and subsequent follow-up were identified. Mean age at CFS was 1.7 years (SD 0.84 years). EEG was obtained at a median of 3 days from the CFS with a range of 1 to 105 days. EEG was normal in 63 patients (74%) and abnormal in 22 patients (26% CI-17-37). Abnormalities included epileptiform activity in 13 patients (15.3%) and slowing in 9 (10.5%) patients. Developmental delay was noted in 16 patients (19%). Family history of epilepsy or unprovoked seizure was present in 21 patients (25%) and febrile seizures in 30 patients (35.2%). MRI or CT was abnormal in 12, normal in 57, and not done in 16. Average length of follow up was 66.3 months (SD 31 months). Epilepsy or unprovoked seizures were noted in 15 patients (17.6%, CI 11-28). On univariate analysis abnormal EEG (OR: 2.25, p=0.18), age at seizure onset (OR=1.36, p=0.35), abnormal neuroimaging (OR=1.25, p=0.76) and family history of epilepsy or unprovoked seizure (OR=1.66, P=0.41) did not predict future development of epilepsy. Developmental delay predicted development of subsequent epilepsy (OR: 4.0, p=0.02) as did male gender (OR=13.6, p=0.01).Conclusions: Abnormalities found on the EEG done within 4 months after the first CFS did not predict development of epilepsy in future and thus initial EEG does not appear to a useful tool for prediction of epilepsy in patients with first CFS. Larger prospective studies are needed to confirm these findings.