Stereotactic placement of depth electrodes in medically intractable epilepsy

Abstract

Object Despite its long-reported successful record, with almost 60 years of clinical use, the technical complexity regarding the placement of stereoelectroencephalography (SEEG) depth electrodes may have contributed to the limited widespread application of the technique in centers outside Europe. The authors report on a simplified and novel SEEG surgical technique in the extraoperative mapping of refractory focal epilepsy. Methods The proposed technique was applied in patients with medically refractory focal epilepsy. Data regarding general demographic information, method of electrode implantation, time of implantation, number of implanted electrodes, seizure outcome after SEEG-guided resections, and complications were prospectively collected. Results From March 2009 to April 2012, 122 patients underwent SEEG depth electrode implantation at the Cleveland Clinic Epilepsy Center in which the authors' technique was used. There were 65 male and 57 female patients whose mean age was 33 years (range 5–68 years). The group included 21 pediatric patients (younger than 18 years). Planning and implantations were performed in a single stage. The time for planning was, on average, 33 minutes (range 20–47 minutes), and the time for implantation was, on average, 107 minutes (range 47–150 minutes). Complications related to the SEEG technique were observed in 3 patients. The calculated risk of complications per electrode was 0.18%. The seizure-free rate after SEEG-guided resections was 62% in a mean follow-up period of 12 months. Conclusions The authors report on a safe, simplified, and less time-consuming method of SEEG depth electrode implantation, using standard and widely available surgical tools, making the technique a reasonable option for extraoperative monitoring of patients with medically intractable epilepsy in centers lacking the Talairach stereotactic armamentarium.

The stereotactic approach for mapping epileptic networks: a prospective study of 200 patients

“…The majority of these electrodes (i.e., 2584 electrodes) were implanted in orthogonal orientation relative to the sagittal plane, with 79 additional electrodes implanted obliquely to target the superior frontal gyrus, posterior orbitofrontal cortex, superior parietal lobule, and/or insula. Within our series, the first 122 patients were prospectively implanted using a stereotactic Leksell frame-based technique that has recently been described by our group; 9 unique to only a small number of centers in North America, the remaining 78 patients were prospectively implanted with the aid of a stereotactic ROSA robotic device (Medtech).…”

“…9 In prospective fashion and following the acquisition of a stereotactic ROSA device at our institution, the remaining 78 patients of this series underwent frameless SEEG implantation under direct robotic guidance. The success rate of both techniques was comparable despite the technological advances in SEEG electrode placement, with successful identification of the epileptogenic zone in 93 patients (76.2%) undergoing the Leksell frame-based technique and in 61 patients (78.2%) undergoing frameless robotic guidance for SEEG implantation.…”

Advancements in Stereotactic Epilepsy Surgery: Stereo-EEG, Laser Interstitial Thermotherapy, and Responsive Neurostimulation

“…Second, individually tailored implants may be designed to interrogate network structures up-and down-stream from the presumed symptomatogenic zone. 8,9 Furthermore, our group is beyond the scope of this article, but several features unique to SEEG planning deserve mention. Stereo-EEG enables recording of the entire cortical grey matter from gyrus to sulcal depth, so it may be advantageous in certain situations for entry to be slightly off the gyral crown.…”

“…Thermal ablation for focal epilepsy was initially described using radiofrequency (RF) thermocoagulation probes. In our experience to date at Jefferson, 27 patients have undergone implantation of a total of 342 electodes (mean 12.7, range [5][6][7][8][9][10][11][12][13][14][15][16][17]. No patient experienced permanent morbidity or mortality related to the SEEG…”

Robot-assisted endoscopic third ventriculostomy: institutional experience in 9 patients

“…The ROSA device has aided neurosurgeons with a multitude of minimally invasive procedures, which include lead placement for deep brain stimulators, brain biopsies, 9 depth electrode placement for seizure monitoring, 4 laser ablation of epileptogenic foci, 5,13 and spinal pedicle screw fixation. 10 This robotic surgical assistant empowers the neurosurgeon to perform precise, stereotactic gestures with the aid of stereotaxy and surgical instrument stabilization.…”