Prenatal diagnosis of schizencephaly by fetal magnetic resonance imaging.

Schizencephaly is a neuronal migration anomaly characterized by gray matter lined clefts extending from the ventricle to the cortical surface leading to specific lesions, well demonstrated by imaging. The lips of the clefts can be fused or separated. Prognosis is related to the extend of the involved cortex. Both genetic and acquired factors can be responsible for this pathology. Three cases of antenatal diagnosed open schizencephaly are reported. Two cases are unilateral and one is bilateral. A cerebral anomaly has been detected in all cases by routine ultrasonography (US) revealing a ventricular dilatation with cortical associated abnormalities. Prenatal magnetic resonance imaging (MRI) permitted the diagnosis in the 3 cases. All cases had led to abortion because of the importance of the cortical defect. The aim of this report is to point out the importance of fetal MRI in the diagnosis of migration disorder and to discuss the medical implications. Indeed, MRI is better suited than US for the prenatal diagnosis of schizencephaly, being able to detect normal and abnormal brain cellular migration, especially with fast imaging (HASTE sequences). With its multiplanar imaging capability, MRI demonstrates the cleft extending from the pial surface to the ventricular ependyma and thus provides characteristic diagnosis of this disorder. Moreover, ventricular dilatation, a frequent anomaly detected by US should be completed with MRI in order to research a neuronal migration disorder. Copyright 2001 S. Karger AG, Basel