Electroclinical syndromes of idiopathic generalized epilepsies in adults

Abstract

Idiopathic generalized epilepsies (IGE) accounting for 20–40% of all epilepsies. International League against Epilepsy (ILAE) Classification recognizes three main IGE subsyndromes that are manifested in adults: juvenile absence epilepsy (JAE); juvenile myoclonic epilepsy (JME) and epilepsy with generalized tonic-clonic seizures only (EGTCSO). JAE is mainly manifested with typical absence seizures (TAS), 80% of patients suffer from GTCS, and 20% have myoclonic jerks (MJ). JME is the most common IGE subsyndrome, characterized by MJ on awakening, GTCS in nearly all patients, and TAS in a third of them. EGTCSO with GTCS occurring predominantly on awakening is probably life-long disease with a high incidence of relapse on withdrawal of treatment. Some types of IGE have not yet been recognized by the ILAE: (1) Jeavons syndrome – a purely reflex IGE predominantly manifested with eyelid myoclonia and electroencephalogram (EEG) abnormalities on eye closure, (2) perioral myclonia with absences, (3) IGE with phantom absences – a type of mild absences before the first GTCS, that usually occurs in adulthood. Both perioral myoclonia with absences and phantom absences are clinically significant because they are probably life-long and are associated with a very high incidence of absence status epilepticus that may escape diagnosis and appropriate treatment.