Childhood-onset epilepsy with and without preceding febrile seizures

Objective: To identify characteristics in children with epilepsy that diffe r between those who did versus did not have a history of preceding febrile seizures. Background: Febrile seizures precede epilepsy in 10 to 15% of chi ldren. Little is known about the specific types of epilepsy associated with febrile seizures. Methods: In a community-based, prospectively identified cohort of children, the association between prior febrile seizures and char acteristics of the children's epilepsy (seizure type, epilepsy syndrome, ag e at onset, underlying etiology, family history) were examined for 524 of t he children who were aged greater than or equal to 1 year at onset of epile psy. Results: Seventy-three (13.9%) had febrile seizures. Children with feb rile seizures were more likely to have a first-degree or a second-higher-de gree relative with febrile seizures and less likely to have childhood absen ce epilepsy and absence seizures compared with children without febrile sei zures. This was especially true for simple febrile seizures. There was no s pecific association with localization-related forms of epilepsy. Complex, b ut not simple, febrile seizures were associated with younger age at onset o f epilepsy. There was no evidence that focal or prolonged febrile seizures were associated with localization-related epilepsy or temporal lobe epileps y per se. Of the three children whose initial MRIs demonstrated hippocampal atrophy, none had a history of febrile seizures. Conclusions: At the time of diagnosis, febrile seizures are not specifically related to temporal lob e epilepsy or localization-related epilepsy in general. A genetic component for febrile seizures is suggested by its positive associations with family history, especially for simple febrile seizures. Complex febrile seizures represent an underlying age-dependent susceptibility.