Abstracts

Rationale: The goal of this study was to assess the clinical and demographic characteristics of children with febrile seizure plus and to investigate the risk factors for this type of seizure on Jeju Island, South Korea, where febrile seizure plus has not been investigated.Methods: We reviewed retrospectively patients whose febrile seizure (FS) continued after 5 years of age (defined as FS plus) among patients who were admitted because of FS to the Pediatric Department at the Jeju National University Hospital between March 2005 and May 2013. Cases were identified using a computerized text search, followed by a manual chart review. We excluded patients with evidence of intracranial infection. Subsequent nonfebrile seizure was defined in this study as afebrile seizure that developed after 5 years of age in patients with FS plus. The variables collected included age, sex, maternal age at birth, birth weight, total number of FS attacks, body temperature at FS onset, presence of complex FS, family history of FS (first-degree relatives), family history of epilepsy, EEG findings, socioeconomic status, parents education level, and subsequent nonfebrile seizure.Results: Two hundred ninety-nine patients were searched for FS. Among them, 60 patients developed FS after 5 years of age (FS plus). These patients (36 boys and 24 girls) were enrolled in the study. The mean age at the time of the study was 98 months. The average age at the first FS was 40 months. The average total number of FS was 5.3. Family histories of FS and epilepsy were found in 17 (28.3%) and 3 patients (5.0%), respectively. Twenty-six (43.3%) children were diagnosed with complex FS. Subsequent nonfebrile seizures were observed in 22 (36.6%) children. Thirty-one of the 60 (51.6%) patients had a body temperature < 39 C at FS onset. We studied these 60 patients based on two groups: with and without subsequent nonfebrile seizures. Complex FS (p < 0.89), low socioeconomic status (p < 0.21), and low level of education of the father (p < 0.055) did not differ between the two groups. Parameters such as sex, maternal age at patient s birth, gestational age, and family history of epilepsy or FS did not differ significantly between the two groups (p < 0.51; p < 0.30; p < 0.89; p < 0.28; and p < 0.56, respectively). EEG abnormalities were observed in 31 patients (51.6%) among the 60 patients with FS plus. Subsequent nonfebrile seizures were observed in 22 (70.9%) of those 31 patients (p < 0.001). A higher number of FS attacks (p < 0.025) and a body temperature < 39 C at seizure onset were observed more frequently in the group with subsequent nonfebrile seizure (p < 0.029).Conclusions: FS plus patients with EEG abnormalities tended to experience subsequent nonfebrile seizures compared with patients with normal EEG findings. A higher number of FS attacks was associated with the development of subsequent nonfebrile seizures. A body temperature < 39 C at seizure onset was correlated with the occurrence of subsequent nonfebrile seizures.