[CT manifestations of schizencephaly].

Schizencephaly is a variety of neuron migration anomalies which are caused by insults to the migration of subependymal neuroblasts during the third to fifth gestational months. It has characteristic CT findings including a hemispheric cleft, either unilateral or bilateral, in the parasylvian region lined with heterotopic gray matter and extending from the pial to the ependymal surface. In type I the lips of the cleft are fused, whereas in type II, these are separated. Polymicrogyria and malformations of septum pellucidum and corpus callosum are common associated findings. Seventeen cases of schizencephaly with only two cases of bilateral clefts were presented in this paper.