Acquired bilateral anterior opercular lesions result in the characteristic Foix-Chavany-Marie syndrome that features expressive dysphasia and pseudobulbar palsy. A developmental congenital variant that represents a restricted disorder of neuronal migration was recently reported. We report a newborn with autopsy-confirmed developmental bilateral perisylvian dysplasia. Polymicrogyria was found on detailed histologic study confirming the only prior pathologic study of this syndrome. The clinical heterogeneity of this disorder with neonatal and childhood modes of presentation is reviewed. Speculation regarding pathogenesis focuses on either a genetically determined selective aberration of neuronal migration or an in utero postmigration vascular accident