Malignant epileptic encephalopathies in children.

Malignant epileptic encephalopathies in children comprise a series of age-related generalized epilepsy syndromes: neonatal myoclonic encephalopathy and early epileptic encephalopathy in the neonatal period, migrating focal seizures in early infancy, infantile spasms and West syndrome, severe myoclonic epilepsy and non-progressive myoclonic encephalopathies in infancy, and Lennox-Gastaut syndrome, myoclonic astatic epilepsy, continuous spike waves in slow sleep and Rasmussen disease in childhood. Clinical and EEG characteristics are the major diagnostic clues. Aetiology remains unknown but for the majority of the cases, a combination of different factors, particularly lesions, genetic predisposition and age-related features seem to be variously combined to produce an intractable condition.