The Clinical Impact of Stereo-electroencephalography (SEEG) Electrode Accuracy
Abstract number :
1.448
Submission category :
9. Surgery / 9A. Adult
Year :
2024
Submission ID :
868
Source :
www.aesnet.org
Presentation date :
12/7/2024 12:00:00 AM
Published date :
Authors :
Thanomporn Wittayacharoenpong, B.Eng. M.Eng. – Monash University
Matthew Gutman, MD FRACS – Monash University
Martin Hunn, MD PhD FRACS – Monash University
Zhibin Chen, PhD – Monash University
Matthew Szmidel, BMedSci – Alfred Hospital
Paul Beech, MD – Alfred Hospital
Jacob Bunyamin, MD MSc – Monash University
Simon Vogrin, PhD – St Vincent's Hospital
Wendyl D'Souza, MBChB, MPH, FRACP, PhD – St Vincent's Hospital Melbourne
Amy Halliday, MD – St Vincent's Hospital Melbourne, The University of Melbourne
Kristian Bulluss, MBBS – St Vincent's Hospital Melbourne
Udaya Seneviratne, MD – St. Vincent's Hospital
Cecilia Harb, BS – Alfred Hospital
Terence J O'Brien, MBBS MD – School of Translational Medicine, Monash University, The Alfred Centre
Patrick Kwan, MD PhD – Monash University
Joshua Laing, MD PhD FRACP – Monash University
Presenting Author: Andrew Neal, MD PhD FRACP – Alfred hospital
Rationale: Factors influencing inaccuracy in Stereo- electroencephalography (SEEG) electrode implantation have been well studied, but the clinical impact of accuracy is poorly understood. This study aimed to investigate the influence of electrode accuracy on i) achieving positive outcomes following SEEG and subsequent surgery and ii) intracranial haemorrhage (ICH).
Methods: 69 consecutive patients who had undergone SEEG in two Melbourne epilepsy centres were included. Post-implantation CTs were coregistered with pre-implantation MRI to locate the actual electrode trajectories (AT). Target errors were calculated between planned and AT at electrode and contact levels. ATs were classified as “off-target” if they did not sample the intended cortical target/s. Mean electrode error and percentage of off-target electrodes were calculated at the patient level. We analysed patient-level outcomes: (1) ‘positive SEEG outcome’ = seizure-freedom post radio-frequency thermo-coagulation (RF-THC) or offered subsequent resection (2) Engel I outcome 6 months post-RF-THC, (3) Engel I outcome 6 months post resection and (4) presence of ICH. ICH was defined based on published grading systems and categorized into transient symptomatic (tICH) and asymptomatic (aICH). At electrode and contact levels, the rates of RF-THC performed at and/or the presence of ICH passing through the trajectory of the electrode or contact were examined (local ICH). Binomial logistic regression examined the relationship between electrode accuracy and clinical implications at the patient, electrode, and contact level.
Results: We analysed 10,149 electrode contacts across 913 implanted electrodes in 69 patients (mean age 34.5+/-10.0 years, mean electrodes per patient 13.2 +/-2.7). Median absolute error at target was 1.9mm [1.3 – 2.7] and 83 (9.0%) electrodes were “off-target. No post-implantation ICH were observed. 18 post-explantation ICH were identified: 78% aICH, 22% tICH and nil associated with permanent deficits. At the patient level, there was no significant association between the mean target error or the percentage of “off-target” electrodes with ICH (p=0.77, p=0.60), ‘positive outcomes after SEEG’ (p=0.16, p=0.71), Engel class I post RF-THC (p=0.36, p=0.25) or surgery (p=0.43, p=0.74). At the electrode level, target error was significantly associated with an electrode being “off-target” (p< 0.001) and with the trajectory passing through ICH (p=0.01), but not with the chance of RF-THC (p=0.15) of that electrode. At the contact level, inaccuracy was significantly associated with a lower chance of RF-THC involving that contact (p = 0.001) and ICH (p < 0.001). Additionally, RF-THC of a contact was significantly associated with an ICH overlapping with the contact location (p < 0.001).
Conclusions: At the patient level, SEEG electrode inaccuracy did not influence post-SEEG clinical outcomes nor ICH rates. However, inaccuracy is strongly associated with ICH at electrode and contact level. Electrode contact inaccuracy is also negatively associated with the chance of RF-THC. Overall, minimising electrode errors may reduce ICH risk and enhance feasibility of RF-THC procedures.
Funding: NHMRC Investigator Grant (Andrew Neal)
Surgery