Epileptic encephalopathies are an epileptic condition characterized by epileptiform abnormalities associated with progressive cerebral dysfunction.These syndromes include early myoclonic encephalopathy and Ohtahara syndrome in the neonatal period,West syndrome and Dravet syndrome in infancy,myoclonic status in nonprogressive encephalopathies,and Lennox-Gastaut syndrome,Landau-Kleffner syndrome,and epilepsy with continuous spike waves during slow wave sleep in childhood and adolescences.Other epileptic syndromes such as migrating partial seizures in infancy and severe epilepsy with multiple independent spike foci may be reasonably added.In this paper,an overview of epileptic encephalopathies including clinical features,etiology,electroencephalogram characteristics,treatment and prognosis are provided.