[Epileptic encephalopathies].

Epileptic encephalopathy, a major neurologic disorder, leads to upper motor involvement and epilepsy. Its clinical expression varies according to cerebral maturity and etiology. Epilepsy manifests by spasms, partial seizures or myoclonia in the newborn, essentially by spasms in the infant, but also by myoclonia or sometimes by multifocal partial seizures. In the child, epileptic seizures have a more varied expression: atypical loss of contact, tonic or tonic-clonic seizures, myoclonia and sometimes status epilepticus. Inter-seizure electroencephalograms of patients of all ages show severe diffuse, constant anomalies. These epilepsies are associated with delayed development, mental retardation and behavioural disorders, requiring appropriate treatment as early as possible.