Abstracts

Novel Scale to Predict Seizure Freedom Following Stereoelectroencephalography

Abstract number : 3.344
Submission category : 9. Surgery / 9C. All Ages
Year : 2018
Submission ID : 494826
Source : www.aesnet.org
Presentation date : 12/3/2018 1:55:12 PM
Published date : Nov 5, 2018, 18:00 PM

Authors :
Alvin Chan, University of California - Irvine; Jeffrey Mullin, University of California - Irvine; Frank Hsu, University of California - Irvine; and Sumeet Vadera, University of California - Irvine

Rationale: Stereoelectroencephalography (SEEG) is an intracranial monitoring technique to localize ictal onset when noninvasive methods are inconclusive. Our aim was to find predictors of seizure freedom for patients undergoing SEEG and surgical intervention to create a scoring system that predicts postoperative rates of seizure freedom at 1 year. Methods: PubMed, Cochrane Library, and relevant sources were queried for high quality, peer-reviewed, primary clinical studies describing seizure outcomes after SEEG and subsequent surgical intervention. Variables potentially related to seizure outcome were subjected to formal meta-analysis. Some variables that were common in a standard presurgical workup and predictive of seizure freedom were developed into a scale. We then utilized our institution’s SEEG patient seizure-free outcomes to assess validity of the scale. Results: Nine hundred ninety-three patients were included in the meta-analysis portion of the study with mean follow-up of 3·28 years. Notable variables predictive of seizure freedom were temporal versus extratemporal seizure onset (OR = 1·93; p < 0·01), right versus left or bilateral hemispheric seizure lateralization (OR = 2·00; p < 0·01), and lesional versus nonlesional pre-operative magnetic resonance imaging (MRI) findings (OR = 2·33; p < 0·01). A scale utilizing these three patient attributes (i.e., temporal localization, right lateralization, and lesional MRI scan) was developed. Patient outcomes at our institution demonstrated no significant difference at one-year when compared with the scale (n = 37).  Conclusions: Using these predictors and the literature, we developed, focused, and validated the “SEEG 3L Scale.” It uses seizure Localization, hemispheric Lateralization, and Lesional MRI findings to predict seizure freedom after surgical intervention with the use of SEEG. Predicted seizure freedom rates were calculated for three (85%), two (60%), one (55%) and zero (< 25%) points. This scoring classification could be useful for framing a discussion with patients who are considering surgical intervention after undergoing SEEG. Funding: None