Possibilities for surgical treatment of the pharmacoresistant form of epilepsy using robot-assisted implantation of deep electrodes for invasive stereoelectroencephalography

The study objective is to determine the effectiveness, safety and information content of robot-assisted implantation of deep electrodes for invasive stereoelectroencephalography (stereo-EEG) monitoring in patients with pharmacoresistant epilepsy. Materials and methods. The study group included 27 patients from 2016 and 2018, who underwent a robot-assisted implantation of stereo-EEG electrodes followed by a 24-hour video-EEG monitoring. Unilateral implantation of electrodes was performed in 22 patients, bilateral – in 6 patients (in 1 patient, due to the ineffectiveness of the operation to remove the epileptogenic focus, implantation was performed twice). MRI-negative epilepsy was in 16 (59 %) patients; 11 (41 %) patients with multiple structural changes. The average time for invasive video-EEG monitoring was 96 hours (from 46 to 253 hours). Results. Based on the information obtained during invasive monitoring, the epileptogenic zones and early distribution were verified: in the temporal lobe in 9 (33 %) patients, in the frontal lobe – 6 (22 %), in the parietal lobe – 2 (8 %), in the occipital lobe – 3 (11 %), in more than 2 lobes – 4 (15 %), in both hemispheres – 3 (11 %) patients. Nineteen (70.4 %) patients underwent surgery to remove the epileptogenic zone. In 11 (58 %) patients extratemporal resection was performed and 8 (42 %) patients underwent anterior-medial temporal and amygdal-hippocampectomy. Follow-up history of more than 6 months after removal of the epileptogenic zone detected by stereo-EEG was monitored in 13 patients. The outcomes of surgical resection were as follows: in 8 (61 %) patients – Engel I, in 1 (8 %) – Engel II, in 3 (23 %) – Engel III, in 1 (8 %) – Engel IV. Conclusion. Robot-assisted implantation of deep electrodes for invasive stereo-EEG monitoring is a safe and effective diagnostic method in patients with pharmacoresistant epilepsy. In patients with MRI-negative epilepsy, stereo-EEG allows to localize and determine the boundaries of the epileptogenic zone, thereby increasing the effectiveness and safety of surgical resection.