[Epileptic encephalopathies].

According to the International League Against Epilepsy's (ILAE) Commission on Classification and Terminology, the term 'epileptic encephalopathy' reflects the notion that epileptic activity in itself can contribute to the genesis of severe cognitive or behavioural disabilities, beyond what could be expected from the pathology underlying the epilepsy. However, in many cases it is difficult to define the boundary between the relative contribution of the epileptic seizures and the underlying cause in the genesis of cognitive deficits. Some epileptic syndromes, such as those of West, Lennox-Gastaut or Dravet, are associated to a high probability of encephalopathic traits. The most frequent causes of epileptic encephalopathy are hypoxic-ischaemic encephalopathy, brain malformations, including cortical dysplasias, chromosomal or genetic disorders, tuberous sclerosis and metabolic diseases.