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 c an be fused or separated. Prognosis is related to the extend of the involve d cortex. Both genetic and acquired factors can be responsible for this pat hology. Three cases of antenatal diagnosed open schizencephaly are reported . Two cases are unilateral and one is bilateral. A cerebral anomaly has bee n detected in all cases by routine ultrasonography (US) revealing a ventric ular dilatation with cortical associated abnormalities. Prenatal magnetic r esonance imaging (MRI) permitted the diagnosis in the 3 cases. All cases ha d 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 diagnosi s of migration disorder and to discuss the medical implications. Indeed, MR I is better suited than US for the prenatal diagnosis of schizencephaly, be ing able to detect normal and abnormal brain cellular migration, especially with fast imaging (HASTE sequences). With its multiplanar imaging capabili ty, MRI demonstrates the cleft extending from the pial surface to the ventr icular ependyma and thus provides characteristic diagnosis of this disorder . Moreover, ventricular dilatation, a frequent anomaly detected by US shoul d be completed with MRI in order to research a neuronal migration disorder. Copyright (C) 2001 S. Karger AG, Basel.