Teaching Case

Poor vision, developmental delay, and hemiparesis.

Presented with poor vision, moderate developmental delay, and right hemiparesis. An MRI examination was performed on a 0.5 Tesla unit, and conventional T1 and T2-weighted sequences were acquired.

Schizencephaly is a form of neuronal migration disorder, in which there is a cleft of the cerebral hemisphere, extending from the lateral ventricle to the pia. Clefts may be unilateral, or bilateral. They are lined by polymicrogyric gray matter. There usually are two types of the condition. Type I consists of a closed cleft, and Type II consists of wide cleft, and the clinical presentation is more severe with wider clefts. A recently proposed theory for the formation of schizencephaly is that this condition is an extreme variant of cortical dysplasia (polymicrogyria), in which the infolding of cortex extends all the way into the lateral ventricle. Congenital cytomegalovirus infection in early gestation can be a cause of schizencephaly. On the other hand, septo-optic dysplasia (deMorsier's syndrome) mainly consists of atrophic optic nerves and tracts, and absence of the septum pellucidum. Hypothalamic-pituitary dysfunction is common in the syndrome, and it can be associated with schizencephaly and the other types of cortical dysplasias.