Abstracts

Rationale: Despite recent FDA approval of novel antiseizure drugs, approximately 30% of epilepsy patients continue to experience drug-resistant seizures that are associated with negative medical and psychosocial consequences. In this population, epilepsy surgery is considered the best option for seizure freedom. Comprehensive preoperative evaluations provide numerous data points with which postoperative expectations can be derived and significant Wada memory asymmetry (WMA) has been associated with greater seizure freedom in standard anterior temporal lobectomy. Minimally invasive surgical techniques (mesial temporal laser ablation) have been rapidly adopted over recent years; though, little is known about the relationship among components of preoperative evaluation and seizure outcome, warranting systematic evaluation of these data. Methods: Through IRB approved retrospective cohort analysis we aimed to assess the relationship between WMA and postoperative seizure freedom (Engel I) in patients who underwent mesial temporal laser ablation at Wake Forest Comprehensive Epilepsy Center from 2012-2016. WMA was calculated by subtracting the ipsilateral injection memory score from contralateral score. WMA of > 25% with worse contralateral performance was considered significant. WMA was calculated separately for each patient for free recall alone and total memory (recall + recognition). Engel Class was assessed at standard intervals and chi square test was used to assess the association among these scores and seizure outcome. We also assessed the prevalence of significant WMA among controls who underwent other surgery or no surgery to compare these data to laser ablation patients. Results: Participants (N=19) were evenly distributed in regards to sex, with females comprising 58% of the sample; 74% were Caucasian. The mean age at surgery was 36; duration of epilepsy was 19 years. The number of prior AED ranged from 2-12. Engel I at 6 months was 86% and 78% at 1 year. Mean follow-up was 1.7 years, and 78% had Engel I outcome at last follow-up. There was no significant difference in the prevalence of total memory WMA among those with Engel I vs. non-Engel I outcome for all 3 time points (p=.69 at 6 months; p=.65 at 1 year; p=.86 at last follow-up). Similarly, no association was found between the presence of free recall WMA and Engel I outcome. When the prevalence of WMA among those who underwent mesial temporal laser ablation was compared to those who underwent other surgeries or no surgery, there were no significant differences. Conclusions: This preliminary analysis did not show any significant association between WMA and seizure outcome following mesial temporal laser ablation. This suggests either that the sample is too small to show any significant relationship between WMA and seizure freedom, or that WMA is not a predictor of seizure freedom after mesial temporal laser ablation. Funding: Study data were collected and managed using REDCap electronic data capture tools hosted at Wake Forest Baptist Health.1 REDCap (Research Electronic Data Capture) is a secure, web-based application designed to support data capture for research studies, providing 1) an intuitive interface for validated data entry; 2) audit trails for tracking data manipulation and export procedures; 3) automated export procedures for seamless data downloads to common statistical packages; and 4) procedures for importing data from external sources. (M01 RR007122 from NCRR/NIH)  1Paul A. Harris, Robert Taylor, Robert Thielke, Jonathon Payne, Nathaniel Gonzalez, Jose G. Conde, Research electronic data capture (REDCap) – A metadata-driven methodology and workflow process for providing translational research informatics support, J Biomed Inform. 2009 Apr;42(2):377-81.