Idiopathic generalized epilepsies.

Abstract The idiopathic generalized epilepsies (IGEs) are a spectrum of epilepsy syndromes that are characterized by seizures of generalized onset, and by known or presumed genetic etiology. These syndromes occur frequently in adults and children aged above 2 years. Manifestations are age-dependent, and seizure types include absence, myoclonic, generalized tonic–clonic, and potentially atonic and tonic. Intelligence is normal, although subtle neuropsychological differences may be present. Broad-spectrum antiseizure medications are indicated; medications that target partial-onset seizures should be avoided. Seizures in some IGE subtypes tend to respond to particular medications or treatments. Prognosis is generally favorable, but remission rates vary between subtypes. The pathophysiology of IGE has been investigated via animal models and neuroimaging techniques, localizing abnormalities to a network of cortical and subcortical/thalamic regions. A family history of epilepsy or febrile seizures may be present. In some pedigrees and syndromes, numerous candidate susceptibility genes and single gene mutations have been found, involving genes that encode for voltage- and ligand-gated ion channels. However, the majority of IGE subtypes are likely produced by complex inheritance involving the interaction of a number of loci. As genetic etiologies are clarified, pathophysiology will be understood more precisely, and the classification of idiopathic generalized epilepsies will be refined.