MR of neuronal migration anomalies

Abstract
Migration anomalies are congenital malformations caused by insults to migrating neuroblasts during the third to fifth gestational months. Included in this group are agyria, pachygyria, polymicrogyria, unilateral megalencephaly, schizencephaly, and gray matter heterotopias. Patients who have these conditions present clinically with developmental delay and seizures, and abnormal motor skills are noted in the more severely affected infants. To determine the utility of MR as a method for imaging in these patients, we used MR to evaluate 13 patients who had the full spectrum of migration anomalies. MR was more sensitive than CT in detecting these anomalies because of its better contrast between gray and white matter. We found that MR was particularly more sensitive in detecting schizencephaly, where recognizing the presence of gray matter lining the cleft is critical to distinguishing that disease from porencephaly, and in detecting polymicrogyria, where critical details of cortical architecture are obscured o...