Abstracts

Rationale: To characterize epilepsy in an elderly population and describe the prevalence of drug-resistant epilepsy (DRE) using recently validated International League Against Epilepsy (ILAE) criteria. Methods: Using a nested case-control design, 72 patients aged 60 years and older (cases) and 223 patients under 60 years old (controls) were identified from the Saskatchewan Epilepsy Program database. Patients’ charts were retrospectively reviewed. Bivariate and multiple logistic regression analyses were performed to identify variables that may better characterize epilepsy in elderly patients.  Results: Forty-seven elderly patients (65%) had focal epilepsy, while sixteen (22%) had unknown epilepsy. Etiologies identified in the elderly cohort included unknown (n=30; 18%), brain tumor (n=14; 19%), degenerative disease (n=4; 6%) and stroke (n=4; 6%). Bivariate analysis revealed a significantly greater proportion of epilepsy cases among elderly patients resulting from tumors (19% vs. 5%, p=p=0.001); degenerative disease (6% vs. 0, p= p= 0.03); and on monotherapy (39% vs. 18%, p=p=0.001). Multiple logistic regression analysis confirmed that stroke (OR=18.3; 95%CI: 2, 165), psychiatric comorbidity (OR=2.8; 95%CI: 1.4, 5.7), and monotherapy (OR= 3.4; 95%CI: 1.68, 6.97) were significant factors that may define epilepsy in elderly patients, and that these patients had significantly decreased rates of developmental delay (OR=0.17; 95%CI: 0.05, 0.60) and DRE (p=0.01).  Conclusions:  In our sample, elderly patients with epilepsy were more likely to be on monotherapy, have seizures resulting from stroke, and have more psychiatric comorbidity. On the other hand, elderly were less likely to have developmental delay and DRE than non-elderly patients. These unique features of aging patients strongly suggest that clinical practice guidelines are needed to facilitate the highest quality of care in elderly patients with epilepsy.  Funding: None