Clinical Impacts of Stereotactic Electroencephalography on Epilepsy Surgery and Associated Issues in the Current Situation in Japan

Abstract

Stereotactic electroencephalography (SEEG) is receiving increasing attention as a safe and effective technique in the invasive evaluation for epileptogenic zone (EZ) detection. The main clinical question is whether the use of SEEG truly improves outcomes. Herein, we compared outcomes in our patients after three types of intracranial EEG (iEEG): SEEG, the subdural electrode (SDE), and a combined method using depth and strip electrodes. We present here our preliminary results from two demonstrative cases. Several international reports from large epilepsy centers found the following clinical advantages of SEEG: 1) three-dimensional analysis of structures, including bilateral and multilobar structures; 2) low rate of complications; 3) less pneumoencephalopathy and less patient burden during postoperative course, which allows the initiation of video-EEG monitoring immediately after implantation and does not require resection to be performed in the same hospitalization; and 4) a higher rate of good seizure control after resection. In other words, SEEG more accurately identified the EZ than the SDE method. We obtained similar results in our preliminary experiences under limited conditions. In Japan, as of August 2022, dedicated electrodes and SEEG accessories have not been approved and the use of the robot arm is not widespread. The Japanese medical community is hopeful that these issues will soon be resolved and that the experience with SEEG in Japan will align with that of large epilepsy centers internationally.

Usefulness of Robotic Stereotactic Assistance (ROSA^®) Device for Stereoelectroencephalography Electrode Implantation: A Systematic Review and Meta-analysis

“…Since recently, implantation of SEEG electrodes with the utilization of various robotic systems has been routinely employed for both adult and pediatric patients in neurosurgical centers globally. 10 - 16 ) To evaluate the effectiveness and safety of the ROSA Ⓡ device concerning accuracy of depth electrode placement, operative time, perioperative complication rates, and seizure outcomes, the presented systematic review and meta-analysis has been specifically directed.…”

“…The use of robotic systems is believed to enhance the precision and accuracy of SEEG electrode implantation. 10 - 16 , 39 ) Indeed, once the trajectory for implantation has been set, the rigidity of the robotic arm reduces involuntary movement, which decreases human error. In their meta-regression analysis, Philipp et al 40 ) demonstrated that robot-assisted stereotactic procedures lessen target error.…”

“…Furthermore, recent technological developments and the introduction of advanced computer-aided robotic systems for neurosurgery have revolutionized the technique of SEEG electrode implantation. 10 - 16 ) In particular, the Robotic Stereotactic Assistance (ROSA Ⓡ ) device (Zimmer Biomet; Warsaw, IN, USA), a neurosurgical system based on state-of-the-art technologies such as infrared tracking, image guidance, and a robotic arm, exhibited several advantages over traditional SEEG electrode implantation methods, that include increased accuracy, reduced operative time, and fewer complications. 10 , 17 - 21 ) Nevertheless, its efficiency and safety still necessitate additional critical evaluations.…”

Endovascular electroencephalography (eEEG) can detect the laterality of epileptogenic foci as accurately as subdural electrodes

“…In cases of uncertainty about lateralization, judgments about lateralization, irritative zone, and seizure onset zone can be made by inserting intracranial electrodes on both sides [ 14 ]. However, the fact that 20 % of patients do not undergo epilepsy surgery, including focal resection, following intracranial electrode placement and instead have the electrodes removed [ 15 , 16 ], along with the risks of intracranial electrodes [ [17] , [18] , [19] , [20] ], makes invasive studies more difficult to perform compared to non-invasive tests due to the invasiveness. Recently, less-invasive SEEG has been becoming mainstream [ 21 ], but some risk of complications remains [ 22 ].…”