Abstracts

Long-term Seizure Outcomes in Patients Deemed Non-resective Seeg

Abstract number : 3.463
Submission category : 9. Surgery / 9C. All Ages
Year : 2024
Submission ID : 645
Source : www.aesnet.org
Presentation date : 12/9/2024 12:00:00 AM
Published date :

Authors :
Presenting Author: Shivanee Sodani, MD – Cleveland Clinic

Claudia Vallin, DO – Cleveland Clinic
Maksim Parfyonov, MD – Cleveland Clinic
Balu Krishnan, PhD – Cleveland Clinic Foundation
Juan Bulacio, MD – Cleveland Clinic

Rationale:
Stereo-EEG is an invasive pre-surgical method to localize the epileptogenic zone in patients considered candidates for potential resective surgeries. However, there is a subset of patients that undergo this procedure who are not deemed good candidates for resective surgeries. Alternative treatment options include focal ablation, palliative neuromodulation and/or medical management only. The aim of this study is to investigate cohort characteristics and long-term seizure outcomes in this patient population.






Methods:
This is a retrospective single-center analysis of adult and pediatric patients who underwent stereo-EEG from 2009 to 2022 and did not undergo resective surgery. Variables that were analyzed included: patient demographics, epilepsy characteristics, prior surgical treatment/invasive evaluations, non-invasive data (scalp EEG, MRI, PET, MEG, SPECT, and language lateralizing studies), pre-implantation hypothesis, stereo EEG implantation details and findings, and post-SEEG management strategies. Seizure outcome was defined based on change in seizure frequency (pre-SEEG and post-treatment) in patients with follow-up for at least 1 year.






Results:
Of 866 patients who underwent stereo EEG, 241 met the inclusion criteria. The mean age of seizure onset was 14.6 years and duration of epilepsy was 17.3 years. Previous invasive monitoring and/or resective surgery were present in 29.8% of patients. The majority (62.2%) had unknown epilepsy etiology and about half of the patients (51.0%) had a normal MRI. The most common pre-implantation hypothesis was temporo-perisylvian (30.7%) and 55.0% had unilateral stereo EEG implantation. In 20.7% of the cases, the stereo EEG ictal onset zone (IOZ) was localized, while in 53.1% the IOZ was multifocal. In this patient cohort, 20.3% were seizure-free for at least 1 year at the last follow-up, of which 46.8% underwent focal ablation and 18.2% medical management only with a mean follow-up of 4.9 years.










Conclusions:
This single-center study analyzed cohort characteristics with the aim to improve our patient selection for surgery and define the best treatment modalities for patients who are not surgical candidates.






Funding: None

Surgery