ANTENATAL DIAGNOSIS OF ISOLATED LISSENCEPHALY BY ULTRASOUND AND MAGNETIC-RESONANCE-IMAGING

Lissencephaly (agyria) is a cortical dysplasia associated with a distu rbance in the migration of neocortical neurons. Because of abnormal so nographic findings in the brain of a 24-week fetus, we carried out ser ial magnetic resonance imaging (MRI) examinations which raised the sus picion of isolated lissencephaly. In the second trimester, an area of damage depicted as low-intensity signals was identified by MRI inside the cortical parenchyma. In the same cortical area, agyria was detecte d later in pregnancy, and postnatally calcification was observed by co mputerized tomography (CT) scan. We believe that ultrasound and target ed MRI examination can Improve our understanding of some disorders of neuronal migration and that earlier diagnosis is feasible if both meth ods are employed and interpreted by sound criteria.