Abstracts

Rationale: Post-stroke epilepsy (PSE) is a common complication of stroke that is associated with increased morbidity and mortality in civilian populations but has not been well-studied in the Veteran population. This study examines 10-year mortality in the cohort of veterans who were admitted to a VA Hospital with acute ischemic stroke over a 12-month period. We aimed to determine risk factors associated with increased mortality in this cohort, with a particular focus on PSE and stroke characteristics.

Methods: This single-center retrospective cohort study included all Veterans admitted to the Portland VA with acute ischemic stroke between 10/1/11 and 9/30/12. Survival in Veterans with PSE versus those who did not develop epilepsy was compared by Kaplan-Meier curve and a Cox proportional hazards model, adjusting for age at time of stroke diagnosis. Covariates we examined included age, incidence of PSE, EEG findings, comorbidities, and stroke characteristics including severity (NIHSS) and localization.

Results: 104 Veterans were admitted for stroke during this time frame. Two of these were female, so they were excluded to improve the generalizability of the survival findings. Of these, 23 (22.5%) underwent EEG testing and 5 (4.9%) developed PSE between the time of their stroke and 10-year follow-up, death, or time of last clinical contact with the VA. The locations of strokes differed in patients with PSE versus patients who did not develop epilepsy: with occipital involvement in 3 (60%) versus 19 (20.4%), frontal in 1 (20%) versus 16 (17.2%), and brainstem in 1 (20%) versus 19 (20.4%). Both groups had low stroke severity with a mean NIHSS of 4.0 in the total cohort and 3.2 in the PSE group. Of note, 4 subjects in the stroke cohort had preexisting epilepsy, but they did not require adjustment to their seizure medication post stroke. Of the included veterans, 79 (77%) passed away by the study end point and 42 (41%) died within five years of stroke. All patients diagnosed with PSE died by study endpoint; two within 5 years of stroke.

Conclusions: In this cohort of US veterans presenting with acute ischemic stroke, 5 veterans (4.9%) developed new onset epilepsy after their stroke. Of these, there were higher rates of occipital lobe involvement than in the PSE group. This possible connection between PSE and occipital lobe stroke has not been previously well documented and warrants future investigation. Mortality rates were high in all veterans post-stroke, but significantly higher in patients diagnosed with PSE. This increased risk of mortality highlights the importance of post stroke management to optimize morbidity and mortality especially in patients who have developed PSE.

Funding: This study received funding support from the VA Epilepsy Centers of Excellence (ECoE) and the VA Office of Academic Affiliates (OAA) Polytrauma/Epilepsy Fellowship