The combination of stereo-EEG and radiofrequency ablation

Abstract

SEEG-guided radiofrequency thermocoagulation (SEEG-guided RFTC), a combination of Stereo-electroencephalography (SEEG) and radiofrequency thermocoagulation (RFTC), has been performed since 2001 in drug resistant epilepsy. The interest of this procedure is to aim at total or partial destruction of the epileptogenic zone, as tailored in each individual patient by the SEEG exploration. These multiple SEEG-guided RFTC lesions of epileptic foci are produced by using a radiofrequency generator connected to the electrode contacts. This review summarizes the results of SEEG-guided RFTC reported in 251 patients. This procedure appears to be safe since complications are rare, minor and usually reversible, which is explained by the use of functional electrical stimulations before RFTC. It makes it also possible to produce RF lesions located very close to cortical areas having a high functional value or being poorly accessible to a conventional surgical procedure. Even if seizure outcome is not as good as results of surgery, 41% of the patients are responders at 12 months with several seizure free patients. The benefit-risk ratio of the SEEG-guided RFTC procedure proved to be particularly favorable for the patients presenting with epileptogenic cortical malformation of development (nodular heterotopy as well as focal cortical dysplasia) and for those in whom surgery is not feasible or risky. For the patients in whom surgery is feasible, SEEG-guided RFTC could be used as a first step, as a predictive therapeutic test before resective surgery.