[Lissencephaly. Clinical, electroencephalographic and radiological aspects].

We report 2 cases of lissencephaly and review the cardinal symptoms: microcephalia, mental retardation, pyramidal syndrome and generalized epilepsy. CT-Scan and MRI show the anatomical abnormalities of this malformation: microcephalia, smooth cortex reducing the surface of white matter and lack of sulci and gyri. The fact that the myelin is normal on MRI suggests that this major disorder of neuronal migration does not come from radial glial fibers.