Level Four Epilepsy Center Experience With Stereo-electroencephalography (P5.5-020)

Objective: To demonstrate that stereo-electroencephalography (SEEG) may successfully replace evaluation with subdural electrodes (SDE) in the majority of patients who need invasive evaluations for epilepsy surgery. Background: SEEG is an informative and safe method of invasive evaluation in patients with medically intractable focal epilepsy. The goal of SEEG is to localize the epileptogenic zone for subsequent therapeutic surgical intervention, but the appropriate balance between traditional subdural grid methods and SEEG is not yet established. Design/Methods: We are reporting results of 105 stereo-electrodes implantations performed by a single neurosurgeon. Demographics, recommended surgical treatment and complications data were collected and analyzed. Results: Average patient age at stereo-electrodes placement was 36.9 years. Average epilepsy duration was 18.7 years. Thirty three patients had previous neurosurgery, including previous resective epilepsy surgery in 13 patients, preceded by subdural electrodes evaluation in seven. Average SEEG monitoring time was 10 days (from 5 to 30). Based on SEEG evaluation results, resection of the epileptogenic zone was recommended for 54 patients, laser ablation for 6, Responsive Neurostimulator (RNS) for 23, resection plus RNS for 11, laser ablation plus RNS for 3. An SDE evaluation after SEEG was recommended for 3 patients, and the second SEEG evaluation was recommended for 3 patients. VNS was recommended for one patient with multifocal SEEG seizure onset. Among a total of 105 implantations, one patient had a subdural hematoma after stereotactic electrodes placement (0.9%). One patient had aseptic meningitis after electrodes removal. Two subjects had superficial wound infection after discharge. Six patients had small (1 cm) subdural hematomas after electrodes removal. Conclusions: Our center experience demonstrates that extra-operative EEG monitoring with stereo-electrodes is a reliable and safe method of intracranial evaluation of patients with medically intractable focal epilepsy. SEEG electrodes placement should be widely implemented for localization of the epileptogenic zone as minimally invasive and highly informative technique. Disclosure: Dr. Podkorytova has nothing to disclose. Dr. Perven has nothing to disclose. Dr. Ding has nothing to disclose. Dr. Agostini has nothing to disclose. Dr. Hays has nothing to disclose. Dr. Alick has nothing to disclose. Dr. Dieppa has nothing to disclose. Dr. Das has nothing to disclose. Dr. Dave has nothing to disclose. Dr. Harvey has nothing to disclose. Dr. Zepeda Garcia has nothing to disclose. Dr. Lega has nothing to disclose.