CAVERNOUS SINUS EEG - A NEW METHOD FOR THE PREOPERATIVE EVALUATION OFTEMPORAL-LOBE EPILEPSY

Purpose. In presurgical evaluation of temporal lobe epilepsy (TLE), in vasive methods are necessary if results of various noninvasive methods are not sufficiently convergent enough to identify the epileptogenic area accurately. To detect the epileptiform discharges originating spe cifically from the mesial temporal lobe, we applied the cavernous sinu s catheterization technique. Methods: We placed Seeker Lite-10 guide w ire electrodes into bilateral cavernous sinus through the internal jug ular veins to record EEG (cavernous sinus EEG) in 6 patients with intr actable TLE. Scalp EEG was simultaneously recorded in all 6 and electr ocorticogram (ECoG) was also recorded in 4. Results: The cavernous sin us EEG demonstrated clear epileptiform discharges, sometimes even when they were absent on the simultaneously recorded scalp EEG. The epilep tiform discharges recorded from the cavernous sinus electrodes were sp ecifically associated with those in the mesial temporal region on ECoG . Ictal EEG pattern originating from mesial temporal lobe was also cle arly documented on the cavernous sinus EEG. Conclusions: This new, sem i-invasive method of identifying epileptogenic areas can detect the ep ileptiform discharges specifically arising from the mesial temporal lo be; it is as useful as or complements the invasive techniques such as foramen ovale or depth recording.