PET, CT, and MRI imaging of neuronal migration anomalies in epileptic patients.

During the investigation of intractable epilepsy, neuronal migration anomalies [NMA] were discovered in three patients. The first patient had abnormally positioned gray matter within the walls of both lateral ventricles. The second patient had a post operative cystic area in the right parietal-occipital lobes and an area of NMA within the right temporal lobe. The third patient had abnormally thickened gray matter in the right operculum. Long term CCTV-EEG monitoring of these three patients revealed ictal discharges originating from the area of abnormal gray matter in patients 2 and 3. PET scanning showed the areas of NMA in all three patients to have similar metabolic activity to normal gray matter. These cases illustrate the value of various imaging modalities and suggest some interesting physiology of a spectrum of neuronal migration anomalies.