[Lissencephalia syndromes].

Lissencephaly is in most cases a genetic anomaly of the brain development with agyria and/or pachygyria. It causes severe psychomotor retardation and epilepsy, which is often resistant to therapy. Some patients with type-I lissencephaly show cranial and facial dysmorphism and a deletion of chromosome 17p13.3 (Miller-Dieker syndrome). The isolated lissencephaly sequence occurs without these features. Patients with type-II lissencephaly present additional malformations of the posterior fossa and of the eyes (Walker-Warburg syndrome) and in some cases muscular dystrophy (cerebro-oculomuscular syndrome). Lissencephaly can be suspected with a high probability by its typical EEG. It is proved by imaging techniques. Therapeutic success is limited, the life expectancy is strongly reduced.