Magnetoencephalography (MEG) is one of the most useful tests to identify potential operculo-insular patients.20 Mohamed and colleagues21 reviewed MEG data of 14 patients with refractory insular seizures and identified the following 3 main patterns of spike sources: 7 (50%) had an anterior operculo-insular cluster, 2 (14%) had a posterior operculo-insular cluster, and 4 (29%) showed a diffuse perisylvian distribution. No spikes were detected in the remaining patients. Spike sources showed uniform orientation perpendicular to the Sylvian fissure. Nine patients underwent insular epilepsy surgery with favorable surgical outcome.