Comparison of neuronavigation and frame-based stereotactic system in implanting epileptic depth electrodes

Abstract

Previously, depth electrode implantation was usually performed using the frame-based stereotactic method (14). The frame-based stereotactic system has high positioning precision, and is suitable for precise positioning and puncturing towards deep structures; for example in stereotactic biopsy or deep brain stimulation (DBS), which need accurate positioning (3, 6). The disadvantages of this method, however, are evident: 1) The puncturing process is complicated and time consuming, making it difficult to implant multiple electrodes (e.g. for stereoelectroencephalography [SEEG]) (16); 2) It is difficult to adjust the puncture direction and path in real-time, especially from a poor posture (16); 3) The puncturing process might injure blood vessels and other vital structures, causing █ INTRODUCTION Intracranial electrode tracing has become an important means for evaluating the epileptogenic focus, especially in patients whose epileptogenic loci cannot be located using electroencephalography and other non-invasive assessment tools. Invasive intracranial electroencephalography (iEEG) is the preferred means of determining the exact locations of epileptogenic foci (12, 21). Intracranial electrodes can be classified as epidural, subdural cortical (including strip-like and grid-like electrode), and depth electrodes, of which the depth electrode has been widely used in epilepsy surgery, and plays an important role in the epileptogenic focus evaluation of the medial temporal lobe (2, 21). AIM:To investigate the application of neuronavigation in the implantation of depth electrodes in patients with epilepsy. MATERIAL and METHODS:Thirty-six patients with epilepsy who were implanted with depth electrodes using neuronavigation were assessed for accuracy of implantation and associated complications. RESULTS:In the imaging navigation group, patients were implanted with 2-14 depth electrodes. The average number of implantations was 4.8 electrodes/case. The average implantation error was 2.03 ± 0.98 mm, exhibiting no significant difference compared to the frame-based stereotactic group. In the imaging group, an average of 19.4 min was required to implant each electrode, which was significantly shorter than the time required in the frame group (34.5 min). The temporal lobe was elucidated as the factor that affects electrode implantation accuracy. One patient in the imaging group exhibited a small amount of bleeding, and one suffered from cerebrospinal fluid leakage; however, the overall complication rate in the imaging group was lower than that in the frame group. CONCLUSION:Imaging navigation provides better means of depth electrode implantation; its implantation accuracy is similar to that of the frame-based stereotactic method and it is less time consuming and causes less complications, and is especially suitable for stereoelectroencephalography, which requires multiple depth electrodes.

Accuracy of intracranial electrode placement for stereoelectroencephalography: A systematic review and meta‐analysis

“…Five studies provided accuracy data for the Leksell, Fischer‐Leibinger, and Talairach frame‐based systems. All studies were retrospective and data were provided as historical control groups for the comparison to frameless and robotic trajectory guidance systems, ROSA and Neuromate, providing level 3 evidence. Hou et al .…”

“…The frameless systems included in the analysis include the Vertek arm (Medtronic), Varioguide (BrainLab), Navigus tool (Medtronic), and the Guide Frame‐DT (Medtronic) . A single study compared the use of the iSYS1 robotic trajectory guidance system for the insertion of 93 electrodes in 16 patients with a historical cohort using the Vertek arm frameless technique .…”

“…All studies were retrospective and data were provided as historical control groups for the comparison to frameless 20,21 and robotic trajectory guidance systems, ROSA 15,22 and Neuromate, 11 providing level 3 evidence. Hou et al 21 used a frameless system involving the Navigus tool in a prospective cohort of 36 patients in whom 173 electrodes were implanted compared to historical use of the Leksell frame in 28 patients for the insertion of 62 electrodes. Surface-tracing registration was used for the frameless system and did not reveal any significant difference in the overall electrode accuracy between the frameless and Leksell frame accuracies.…”

Stereoelectroencephalography in children: a review

“…Looking at operative times per electrode, frameless times were significantly reduced compared with frame-based times (19.4 vs 34.5 min/electrode, respectively). 22 It should be noted that this frameless implantation time is relatively high compared with those reported in the literature. Roessler et al averaged 12 minutes for each electrode.…”

“…They found no significant difference in implantation error measurements (2.03 ± 0.98 mm vs 1.79 ± 0.82 mm) or EZ localization rates in their series (88.9% vs 82.1%) between frameless and frame-based SEEG. 22 No hemorrhage or infections were reported. Looking at operative times per electrode, frameless times were significantly reduced compared with frame-based times (19.4 vs 34.5 min/electrode, respectively).…”