Abstracts

Rationale: To identify the risk factors for subsequent epilepsy in patients with complex febrile seizures using a single-center retrospective cohort. Methods: The medical records of 1,091 patients discharged with a diagnosis of febrile seizures from the Seoul National University Bundang Hospital from February 2004 to October 2009 were reviewed. One hundred eighty-three patients (107 boys and 76 girls) with complex febrile seizures were included in the analysis. Clinical characteristics, including features of complex febrile seizure, initial interictal electroencephalographic findings, and subsequent epilepsy, were reviewed and the relative risk of subsequent epilepsy was estimated. The mean follow-up duration for subsequent epilepsy was 5.7 years (range, 2.15-8.0 years). Results: Complex febrile seizures were observed in 22.6% of all patients with febrile seizures. Among 183 patients with complex febrile seizures, 22 patients (12.0%) developed subsequent epilepsy. The presence of multiple seizures for 24 hours was significantly more frequent in patients with subsequent epilepsy (P = 0.011; relative risk, 2.76; 95% confidence interval, 1.22-6.24), whereas the presence of focal or prolonged seizures (> 15 minutes) was not significantly different. Epileptiform discharges (focal in all cases) were significantly more frequent in patients with subsequent epilepsy (50% vs 13%, P < 0.001), with a relative risk of 4.23 (95% confidence interval, 1.99-8.95). Conclusions: The presence of multiple seizures or epileptiform discharges is a significant risk factor for subsequent epilepsy in patients with complex febrile seizures. Electroencephalography should be considered in all patients with complex febrile seizures who had multiple seizures.