Abstracts

Rationale: Malignant rolandic-sylvian epilepsy (MRSE)in children has been defined as a form of epilepsy characterized by medically refractory sensorimotor seizures, normal MRI, frontocentral EEG spikes, and cognitive problems. Rolandic-sylvian spike sources have previously been identified. We present 3 patients with MRSE who underwent EEG source analysis to further localize their epileptogenic zones. Methods: Three children with MRSE ages 3-4 years underwent EEG source localization using BESA software. Scalp EEG was recorded using 10-20 international system with placement of additional electrodes at F9/F10 and P9/P10 for more accurate source localization. EEG activity was digitally recorded referentially to midline electrodes. Continuous monitoring with digital video and EEG was performed using the Nicolet digital video/EEG system. Dipole source analysis was done on routine scalp EEG using BESA software. All three children had interictal epileptiform discharges, as well as averaged waveforms, analyzed. Two children also had ictal discharges analyzed. Principle Component Analysis was used to separate potential concurrent sources. In the one child who had surgery thus far, the BESA analysis was done retrospectively on non-invasive scalp EEG. Results: All 3 children had similar seizure semiology consisting of repetitive eye-blinking, head nodding, and oro-lingual automatisms. EEG dipole analysis for all 3 children showed localization in the lower peri-rolandic region. Individual and averaged waveforms both showed a source in this region. During cortical stimulation in the surgical patient, stimulating the area under the ictal-onset zone elicited rapid eye blinking similar to the seizure semiology. This was the cortical region subsequently resected. That child is currently seizure free. Conclusions: BESA localized a very consistent epileptogenic region in all three children, who also all had very similar seizure semiology. In the one child that has required epilepsy surgery, the BESA retrospectively predicted a source that was very close to the resected cortical region. In future studies, it may be beneficial to study and compare dipole sources of both benign rolandic epilepsy and malignant rolandic-sylvian epilepsy to see if discernable features exist that may differentiate the two syndromes.