586.1 Febrile SeizuresMohamad A. MikatiFebrile seizures are seiz ures that occur between the age of 6 and 60 m o with a tem perature of 38?C or higher , that are not the result of central nervous system infection or any metabolic imbalance, and that occur in the absence of a history of prior afebrile seiz ures. A simple febrile seizure i s a primary generaliz ed, usually tonic-clonic, attack associated with fever , lasting for a max imum of 15 m in, and not recurrent within a 24-hour period. A complex febrile seizure is more prolonged (>15 m in), is focal, and/or recurs within 24 hr . Febrile status epilepticus is a febrile seizure lasting >30 min.Between 2% and 5% of neurologically healthy infants and children ex perience at least 1, usually simple, febrile seiz ure. Sim ple febrile seiz ures do not have an increased risk of m ortality even though they are concerning to the parents. Com plex febrile seiz ures m ay have an approximately 2-fold longterm increase in m ortality , as compared to the general population over the subsequent 2 yr , probably secondary to coex isting pathology . There are no long-term adverse effects of having 1 simple febrile seiz ures. Specifically , recurrent sim ple febrile seizures do not dam age the brain. Com pared with agem atched controls, patients with febrile seizures do not have any increase in incidence of abnormalities of behavior , scholastic performance, neurocognitive function, or attention. Children who develop later epilepsy m ight experience such difficulties. Febrile seizures recur in approximately 30% of those experiencing a first episode, in 50% after 2 or m ore episodes, and in 50% of infants