Epilepsy and the funny sulcus

The presence of a discrete, removable lesion that appears to cause a patient's epilepsy is a powerful predictor of a favorable seizure outcome from epilepsy surgery.1 Since the MRI is initially interpreted as normal in about a quarter of surgical candidates,2 hunting for an inconspicuous, overlooked lesion is a habit of the epilepsy neurologist and neurosurgeon. The “needle in the haystack” often turns out to be focal cortical dysplasia (FCD), often only manifest on structural MRI by mild cortical thickening, minimal signal change, blurring of the gray–white junction, or subtly malformed sulcal or gyral surfaces.