Pre-surgical Stereo-encephalographic Cortical Stimulation Evaluation of After-Discharges Impacts Post-Surgical Outcomes
Abstract number :
3.446
Submission category :
9. Surgery / 9C. All Ages
Year :
2022
Submission ID :
2232855
Source :
www.aesnet.org
Presentation date :
12/5/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:28 AM
Authors :
Anam Asim, B.Sc, M.Sc – Schulich School of Medicine and Dentistry; Matthew McShane, B.Sc – Schulich School of Medicine and Dentistry; Elma Paredes-Aragón, MD – London Health Sciences Center; Greydon Gilmore, B.Sc, M.Sc, PhD – London Health Sciences Center; Seyed Mirsattari, MD, PhD, FRCPC – London Health Sciences Center
This is a Late Breaking abstract
Rationale: Individuals who live with drug resistant epilepsy may be candidates for resective surgery following an extensive pre-surgical workup. As a part of their workup, cortical stimulation may be performed to map the epileptogenic zone and its relationship to functional cortices to delineate resection areas. The stimulation may elicit abnormal waveforms known as after-discharges (ADs). ADs represent hyper- excitable otherwise healthy tissue that when stimulated is able to produce epileptiform discharges that may develop into seizures. The purpose of this study was to determine whether there is an association between patient outcomes and the resection of tissue eliciting ADs._x000D_
Methods: A retrospective analysis of 183 patients that underwent surgery with implantation of depth electrodes as part of a presurgical evaluation was conducted at the London Health Sciences Center from 2015- present. Out of those patients, 101 patients received presurgical cortical stimulation. ADs were recorded in 94 patients from which 54 patients were treated with resective surgery. 24 patients were evaluated to determine whether electrodes eliciting ADs overlapped with the resected area post-surgically using pre and post-operative co-registered MRI images and whether or not the resection of these areas affected seizure outcome measured by the Engel score. _x000D_
Results: The majority of patients in whom the AD eliciting tissue was resected had an Engel class I (n = 10, 56%) and had the best post-surgical outcome. Those patients in whom the AD eliciting area was not resected fell in Engel Class IV (n = 3, 50%) with a poor post-surgical outcome. The average follow up time for patients was 25 months post-surgery. _x000D_
Conclusions: Cortical stimulation should be performed in all patients implanted with depth electrodes. Results from 24 patients who underwent resective surgery showed that those in whom the AD eliciting area was resected had promising post-surgical outcome (Engel Class I). In contrast, patients in whom the AD eliciting area was not resected fell in the worst post-surgical outcome (Engel Class IV). AD must be taken into consideration when considering resection margins. _x000D_
Funding: None
Surgery