title: Clinical and EEG risk factors for subsequent epilepsy in patients with complex febrile seizures.
abstract: OBJECTIVE
  To identify the risk factors for subsequent epilepsy in patients with complex febrile seizures from a single-center retrospective cohort.
  
  
  METHODS
  The medical records of 1091 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 who showed normal neurocognitive development were included in the analysis. Clinical characteristics, including features of complex febrile seizure, initial interictal electroencephalographic findings, and subsequent epilepsy, were reviewed and the odds ratio of subsequent epilepsy was estimated. The mean follow-up duration for subsequent epilepsy was 6.1 years (range, 2.5-8.0 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. Prolonged (>10 min) seizure (p=0.031; odds ratio, 3.04; 95% confidence interval, 1.11-8.32) or the presence of multiple seizures for 24 h (p=0.032; odds ratio, 3.63; 95% confidence interval, 1.12-11.8) was significantly more frequent in patients with subsequent epilepsy, whereas the presence of focal seizure was not significantly different. Epileptiform discharges (focal in all cases) were significantly more frequent in patients with subsequent epilepsy (50% vs. 13%, p=0.002), with an odds ratio of 5.15 (95% confidence interval, 1.84-14.5).
  
  
  CONCLUSIONS
  The presence of 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 especially those who had multiple or prolonged seizures.
authors.affiliation: Department of Pediatrics, Seoul National University Bundang Hospital, Gyeonggi-do, Republic of Korea.
authors.forename: Hunmin
authors.initials: H
authors.lastname: Kim
authors.forename: Sung Hwan
authors.initials: SH
authors.lastname: Byun
authors.forename: Jon Soo
authors.initials: JS
authors.lastname: Kim
authors.forename: Byung Chan
authors.initials: BC
authors.lastname: Lim
authors.forename: Jong-Hee
authors.initials: JH
authors.lastname: Chae
authors.forename: Jieun
authors.initials: J
authors.lastname: Choi
authors.forename: Ki Joong
authors.initials: KJ
authors.lastname: Kim
authors.forename: Yong Seung
authors.initials: YS
authors.lastname: Hwang
authors.forename: Hee
authors.initials: H
authors.lastname: Hwang
mesh_terms: D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D004569:Electroencephalography / Q000379:methods*; D004827:Epilepsy / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D003294:Seizures, Febrile / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology*; D055815:Young Adult