Febrile seizure and related syndromes

Febrile seizures (FS) are the result of particular sensitivity to fever in the developing brain, have a major genetic predisposition, and nearly always have a benign outcome. Febrile seizures are the most common for of seizures in childhood. They have been observed in 2-6% of children before the age of 5 years, but in some populations this figure increase to 15%. Febrile seizures could be the first manifestations of epilepsy. About 13% of epileptic patients have a history of febrile seizures, and 30% have had recurrent febrile seizures Their phenotypic characteristics allow, in the majority of cases, a classification of the seizure, an elaboration of a prognosis and to assume a specific therapeutic attitude. It is possible to describe a spectrum according to their severity, from the benign simple seizure to the more complex, febrile seizure plus (GEFS+), Dravet syndrome, Epilepsy syndrome related infection febrile FIRES and Idiopatic Hemiconvulsion Hemiplegia and Epilepsy syndrome (IHHE). FS has a multifactorial inheritance, suggesting that both genetic and environmental factors are causative. Five areas of the genome have shown to be linked to FS in some ways. Two of them, FEB1 and FEB2 found on chromosomes 8 and 19p, are only involved in FS. During the past decade, molecular genetic studies have contributed to identification of genetic factors involved in febrile seizure and related disorders marking the necessary of careful follow up of the patients in order to detect risk factor earlier. We have reviewed the medical literature to update current knowledge of febrile seizures, their prognosis and their relation to new epileptic syndromes.