Authors :
Presenting Author: M. Claudia Burbano, MD – Western University
Ivan Castro, MD – Western University
Hellen Kreinter, MD – University of Ottawa
Giovanni Pellegrino, MD, PhD – Western University
Jorge Burneo, MD, MSPH, FAAN, FAES, FRCPC – Western University
Michelle-Lee Jones, MD, MDCM, FRCPC, CSCN – Western University
Keith W MacDougall, MD – Western University
Jonathan C Lau, MD, PhD – Western University
David A Steven, MD, MPH, FRCSC, FACS – Western University
David Diosy, MD – Western University
Ana Suller-Marti, PhD – Western University
Rationale:
Stereoelectroencephalography-guided radiofrequency thermocoagulation (SEEG-guided RFTC) has emerged as a safe and effective diagnostic and therapeutic approach for focal drug-resistant epilepsy (DRE), with its use steadily increasing in recent years. However, limited information is available on the electrophysiological changes observed on stereoelectroencephalography (SEEG) recordings after ablation and its role in predicting outcomes. The aim of this study is to describe the acute electrophysiological findings on SEEG recordings following SEEG- guided RFTC in patients with focal DRE.
Methods:
This retrospective, observational, single-center study included patients who underwent SEEG-guided radiofrequency thermocoagulation (SEEG-RFTC) and continued to be SEEG monitored post-intervention. Demographic characteristics, number of electrodes and contacts ablated, hours of recording post SEEG-guided RFTC, electrophysiological findings (interictal activity and seizures) and responder rate (defined by more than 50% reduction of seizure frequency in a lapse of at least 3 months) were analyzed. Results:
Thirty-two patients were included, 46.9% (n=15) were female. The median age at RFTC-SEEG was 34.5 years (IQR 24–44.5). A median of 14 electrodes (IQR 13–16) were implanted per patient, with a median of 11 contacts ablated (IQR 5–17.5). In 46.9% (n=15), the seizure onset zone was completely ablated. The most frequently ablated region was the insula (50%, n=16) followed by the frontal lobe (34.4%, n=11). Post-RFTC SEEG recordings lasted a mean of 79 hours (IQR 23–120, range 18-360). Thirteen patients (40.6%) showed interictal spikes in ablated contacts. Nine patients (28%) experienced seizures post-RFTC, of which seven were electroclinical. The median latency of seizures post-RFTC was 17 hours (IQR 10–30). Six of these patients underwent a second SEEG-guided RFTC, with five achieving responder status. From the total cohort of patients who underwent SEEG-guided RFTC, twenty patients (62.5%) were considered responders after SEEG-guided RFTC. Out of these, nine (47.4%) were seizure-free at 3 months, and five (26.3%) remained seizure-free at 6 months following SEEG-guided RFTC.
Conclusions:
Our findings suggest that post-RFTC SEEG recordings provide clinically meaningful information, including the presence of seizure recurrence, which may guide the decision to perform additional ablations during the same monitoring period. Further studies with larger cohorts are necessary to validate these observations and better define the clinical utility of post-RFTC SEEG monitoring. Funding: No funding was received towards this work.