An unusual type of primary cerebral hemihypotrophy with signs of dysfunctional neuronal migration.

We describe the neuropathological features of a complex brain malformation characterized by cerebral hemihypotrophy with ipsilateral lissencephaly, periventricular nodular heterotopia and macrogyria. The contralateral hemisphere showed only slight alterations of the gyral pattern and a limited periventricular gray matter heterotopia. The clinical picture of the patient, who died at the age of 15 years, consisted of severe oligophrenia, intractable seizures and left hemiparesis. We discuss the nosological status of this neuronal migration disorder of apparently unknown origin.