Generalized spike-wave discharges occur in 49% and photosensitivity in 42% of children with benign FS followed until 11 to 13 years of age.
Although these abnormalities occur most often between 5 and 6 years of age, a proportion will appear at an earlier age.
Thus, epileptiform abnormalities are common in children with FS and are a poor predictor of later epilepsy.
In addition, first febrile seizures occur before 3 years of age in 89% of children with FS6 and EEG has a low sensitivity in that age group.