Abstracts

Rationale: First-time childhood seizures are typically characterized as febrile or unprovoked. Nonfebrile children with a seizure during mild acute illness (nonfebrile illness seizure) do not fit into this classification and have been excluded from epidemiological studies in the past. Methods: We studied the underlying viral illnesses and clinical outcomes in children with first-time seizures with and without fever. Results: 112 children were enrolled in the emergency department at the time of their 1st seizure and followed monthly for seizure recurrence. Children with gastrointestinal (GI) illness at the time of their 1st seizure (n=35) were more likely to have a nonfebrile seizure compared to children with other acute illnesses (Relative risk (RR): 2.9; 95% confidence interval (CI): 1.4, 6.1). The children with GI illness were more likely to have a cluster of seizures at the initial episode (RR: 2.5; 95% CI: 1.4, 4.3). Of 21 children with GI illness and stool samples tested to date, 9 (43%) were positive for rotavirus. The overall incidence of a 2nd seizure episode was 21.3 per 100 child-years (95% CI: 14.4, 31.6). The incidence of a 2nd seizure in the GI illness group was 6.5 per 100 child-years (95% CI: 2.1, 20.2). We used Cox regression to compare rates of a 2nd seizure between illness groups. Children with a GI illness at the time of their 1st episode had a reduced hazard of a 2nd episode compared to children with other acute illnesses (Estimated Relative Risk: 0.23; 95% CI: 0.07, 0.81). Conclusions: We conclude that the specific underlying viral illness, rather than fever alone, is an important factor in understanding the epidemiology of first-time childhood seizures in the setting of illness. This research was partially funded by an anonymous donor to Children’s Hospital and by the Children’s Hospital Research Institute.