pediatrics
Malformed Cerebral Hemispheres
Polymicrogyria
Polymicrogyria, in which the gyri are small and overabundant, also involves abnormal neuronal migration. Other common findings include simplified or absent cortical lamination in affected regions, heterotopic gray matter, a hypoplastic or absent corpus callosum and septum pellucidum, and malformations of the brain stem and/or cerebellum. The structural abnormalities may be diffuse or focal. The most common area of focal involvement is the perisylvian fissure (bilaterally or unilaterally). The termperisylvian syndromeis sometimes used when children present with features of epilepsy, facial and oral motor weakness, prominent speech and language delays, and usually bilateral polymicrogyria in the sylvian fissure region. Polymicrogyria is highly associated with Schizencephaly , in which there are abnormal slits, or clefts, in the cerebral hemispheres. ), and primary maternal infection with cytomegalovirus (ie, in which the mother has no prior immunity—see Congenital and Perinatal Cytomegalovirus Infection (CMV) ). The most common clinical manifestations are seizures, intellectual disability, and spastic hemiplegia or diplegia (see also Schizencephaly ). Treatment of polymicrogyria is supportive. 