Anterior motor strip displacement in a boy with right frontal gray matter heterotopia undergoing epilepsy surgery.

The case of a 14-year-old boy with behavioral problems and medically refractory epilepsy related to symptomatic gray matter heterotopia in the right frontal lobe is reported. The patient underwent subdural cortical grid placement for seizure localization and functional mapping prior to lesionectomy. On the basis of the patient's MRI scan, it was predicted that the motor cortex was located adjacent to the abnormality, well anterior to its expected location. This prediction was confirmed by stimulation mapping. The patient underwent successful resection of the lesion under the guidance of the cortical map. Postoperatively, his seizures and behavior improved markedly. This case highlights how eloquent cortex can rarely be drawn toward a region of gray matter heterotopia. In addition, he is one of the few reported cases of focal cortical dysplasia resection with resultant improved behavior. These observations of unusual cortical representations have implications in epilepsy surgery planning.