gms | German Medical Science

Objective: To describe a large series of robot assisted Stereo-ElectroEncephaloGraphy (SEEG) procedures.

Method: We retrospectively reviewed and analyzed 593 consecutive SEEG procedures performed at our center between 1996 and 2014 on 566 patients. Noninvasive anatomo-electro-clinical data of every patient were reviewed for planning a tailored strategy of exploration. All procedures were subsequently performed according to Talairach methodology, incorporating modern technologies throughout the years, such as intraoperative imaging (O-arm, Medtronic, Minneapolis, Minnesota) and robotics (Neuromate^®, Renishaw-mayfield SA, Nyon, Switzerland). 3203/7809 electrodes were implanted with robotic assistance. In vivo application accuracy was measured on a sub-dataset of 81 robot-assisted procedures (1050 electrodes).

Results: The robot was introduced in our workflow in 2001, initially only for oblique trajectories. Thanks to the availability of multimodal 3D images, we switched to fully robotic implantations in 2009. The methodology allowed a successful implantation in all cases. Major complication rate was 2.6% for the earlier 419 procedures, 0.5% for the latest (fully robotic) 174 (P=0.2). Median euclidean error was 0.78 mm (InterQuartile Range 0.49 - 1.08) at the entry point, 1.77 mm (IQ range 1.25 - 2.51) at the target point. Besides the diagnostic usefulness of SEEG, we exploited also the possibility of performing SEEG-guided radio-frequency thermo-ablations. Nodular peri-ventricular gray matter heterotopy is the best indication for this treatment: 4/5 patients are seizure-free with a one year minimum follow-up.

Conclusions: At the best of our knowledge, this is the largest series of SEEG procedures ever published. This study suggests that SEEG is safe and accurate. Traditional Talairach methodology, implemented by multimodal planning and robot-assisted surgery, allows direct electrical recording from superficial and deep-seated brain structures, providing essential information in the most complex cases of drug-resistant epilepsy. Moreover, in well selected cases, SEEG provides also a successful treatment option.