Genetic generalized epilepsies

Concept of genetic generalized epilepsy versus idiopathic generalized epilepsy. The idiopathic generalized epilepsies (IGEs) are a subgroup of genetic generalized epilepsies (GGEs), comprised of the following 4 syndromes: childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy, and epilepsy with generalized tonic-clonic seizures alone. These 4 syndromes may show some degree of overlap. In addition to the IGEs, GGEs include (1) individuals with generalized seizure types who do not meet criteria for a specific syndrome and (2) less common generalized epilepsy syndromes. These latter syndromes also have a genetic basis and may occur in the setting of normal intellect or intellectual disability. Some present with an epileptic encephalopathy such as epilepsy with myoclonic atonic seizures, whereas other syndromes, such as epilepsy with myoclonic absences and epilepsy with eyelid myoclonia, may be associated with a developmental and epileptic encephalopathy, an epileptic encephalopathy, or a developmental encephalopathy. Other syndromes such as myoclonic epilepsy in infancy may present as a generalized epilepsy in a child with a developmental encephalopathy (ie, intellectual disability) or normal intellect.