Objective: Patients with febrile seizures (FSs) are observed in emergency departments or admitted to hospitals because of the possibility of recurrence. There are no guidelines regarding the observation time for recurring FS. The aim of this study was to identify the rate, time, risk factors, and cumulative probability of early recurrence.
Patients and methods: This study was a retrospective chart review of patients visiting an emergency department with FS from January to December 2011. Early recurrence was defined as FS recurring within 7 days after the first episode. Patients were divided into 2 groups: early recurrence and nonearly recurrence. The 2 groups were compared in terms of demographics, clinical data, and laboratory findings to identify risk factors for early recurrence. The cumulative probability over time was determined.
Results: In total, 228 patients were identified. The recurrence rate was 17.5% (40/228), and the median time to recurrence was 6.0 hours (interquartile range, 1.1-13.0 hours). The overall cumulative probability of early recurrence was 8.8% within 6 hours, 12.7% within 12 hours, and 15.8% within 24 hours. Most recurrences (90.0%) occurred within 24 hours of the first FS. Early recurrence occurred frequently in patients with nongeneralized-type seizures or seizures of 15-minute duration or longer.
Conclusions: The majority of recurrent FSs occurred in the first 24 hours. The type and duration of seizures were significant risk factors for early recurrence.