Abstract
Centers that perform presurgical epilepsy evaluations disagree on whether depth or subdural electrodes represent the optimal technique for invasive recording, especially in seizures originating outside the temporal lobe. A 13-year-old girl with a normal magnetic resonance imaging scan had unlocalized partial onset seizures, despite scalp and subdural grid ictal video/EEG recordings. Repeat video/EEG with depth electrodes showed a discrete site of continuous interictal spiking and seizure onset that was located 2-2.5 cm beneath the surface of the sensory cortex. The resected region showed focal cortical dysplasia and the patient had greater than 95% seizure frequency reduction at 3-year follow-up. We conclude that although subdural electrodes have many advantages when recording seizures outside the temporal lobes, depth electrodes may provide superior recordings when the epileptogenic region is beneath the cortical surface.