Abstracts

Rationale:
Resective surgery in older adults with drug-resistant epilepsy provides seizure outcomes comparable to younger adults, despite the potential for complications. A recent study analyzed predictors of surgical resection in adults aged ≥ 50 years. ¹ However, in our rapidly aging society, many individuals over 60 are now undergoing surgical evaluation. We aim to analyze prognostic factors associated with seizure recurrence (Engel II-IV) in adults ≥ 60 years.

¹ Thomas, B., et al. Predictive factors of postoperative outcome in the elderly after resective epilepsy surgery. Revue Neurologique, 2022 June; 178(6):609-615.

Methods:
After IRB approval, we conducted a retrospective review of individuals aged ≥ 60 years who underwent resective epilepsy surgery between 2000 to 2021 at Cleveland Clinic. Variables collected included age, sex, epilepsy duration, epilepsy risk factors, MRI lesion, invasive EEG use, auras, semiologies, and ictal scalp patterns (single vs multiple/non-localizable), type of surgery, pathology, duration until follow up or recurrence of seizures, Engel Outcome and Charlson Combined Score (CCS, prognostic index for one year mortality based on medical comorbidities). To assess variables associated with seizure recurrence, we fit Cox proportional hazards models, where time to seizure recurrence was the dependent variable. The final model selection was performed using the backward stepwise elimination approach based on the Akaike Information Criterion. The criterion estimates the fit of each statistical model, penalizes overfitting, and provides a means to select relevant variables that improve the model even if they do not reach the significance threshold (p < 0.05). We checked for multicollinearity using variance inflation factors. Visual examination of Schoenfield residuals confirmed the proportional hazards assumption. Hazard ratios (HR) and 95% confidence intervals (CI) were computed.