Duration of Recognized Fever Before Febrile Seizure Can be a Predictive Factor for the Development of Complex Febrile Seizures

Abstract

Purpose: A history of complex febrile seizure is associated with an increased risk to develop epilepsy. We examined the correlation between complex febrile seizures and duration of recognized fever prior to the onset of febrile seizure. Methods: This retrospective study included 680 children admitted to Chung-Ang University Hospital with febrile seizures between January, 2010 and December, 2014. Children were assigned to 4 groups based on the time of fever detection: Group 1 (at the time of seizure), Group 2 (< 24 h prior to seizure), Group 3 (between 24 and 48 h prior to seizure), and Group 4 ( >48 h prior to seizure). Results: A significant correlation was observed between the duration of recognized fever prior to the onset of febrile seizures and occurrence of complex febrile seizure (p = 0.005). Maximum temperatures before seizure and during seizure did not differ between the groups (p = 0.192 & p = 0.095, respectively). Complex febrile seizure was more common in Group 3 than in any other group. Additionally, on dividing the patients into those with fever duration <24 h and ≥24 h, incidence of complex febrile seizures in the latter group was higher. Incidence of complex febrile seizures in Group 3 was the highest among the groups even when the analysis was restricted t o patients having their first attack of febrile seizure. Conclusion: The duration of recognized fever prior to febrile seizures may be a risk factor for complex febrile seizures. Children having fever 24~48 hours prior to febrile seizure had a significantly higher incidence of complex febrile seizures.