Abstracts

Rationale: Epilepsy in older adults is the fastest growing demographic amongst new onset seizures. Stroke accounts for 36% of all seizures in adults aged 65 years and older. The treatment of seizures post-stroke remains controversial. The use of anti-epileptic drugs(AEDs) is associated with negative side effects, while recurrent seizures can negatively affect stroke outcomes. There are no guidelines as to when it is appropriate to treat and a small number of studies report varying risk factors. The purpose of this study is to expand on known risk factors and to allow for risk stratification of the development of post-stroke epilepsy. Methods: Upon IRB approval, data was collected, retrospectively reviewed on patients greater than 60 years of age, seen from January 1st 2011 to December 31st 2016. Eligible patients had a history of stroke and seizure(s). Individuals with history of epilepsy prior to stroke were excluded. Data collected included patient demographics, specific characteristics of stroke and seizures, severity of epilepsy at follow-up. The primary outcome of the study was development of epilepsy following causative stroke. Epilepsy was defined as recurrence of seizures occurring at least 2 weeks apart. Causative stroke was defined as the stroke which chronologically preceded initial seizure and was clinically responsible for the initial seizure. Results: Sixty-nine patients (36 female) met eligibility criteria. Mean age at time of causative stroke was 67±11 years. First seizure occurred at 69±10 years. Ischemic stroke was the most common causative stroke(59%), followed by intracerebral hemorrhage (34%), ischemic stroke with hemorrhagic conversion (6%) and venous infarction (1%). All patients were treated with at least one AED after their first seizure. Thirty-three patients (48%) developed epilepsy, of which 29(88%) had an ischemic stroke and 29 (62%) had their first stroke(p=0.004). There was no difference in the number of AEDs being taken between those who developed epilepsy and those who did not(p=0.68). Predictors of epilepsy included seizures that secondarily generalized (p = 0.029), initial seizure occurring greater than 2 weeks after causative stroke (p = 0.0002) and younger age at causative stroke (p = 0.006). Individuals on more hypertensive agents trended towards a higher likelihood of epilepsy.  Use of insulin was associated with no recurrence of seizures(p = 0.009). Race, gender, large vessel occlusion, ICH score, and Charleston Comorbidity Index were not predictors of epilepsy. Conclusions: Development of epilepsy in patients with seizures post-stroke is multifaceted and more likely to occur in individuals of a younger age, those with seizures who secondarily generalize and late onset of initial seizure. Data also suggested a possible association between ischemic stroke, as well as hypertension. Insulin use was found to be a protective factor in decreasing risk of epilepsy. Given that most epilepsy patients developed seizures after first stroke, recurrent stroke may not be a predictor of epilepsy. The above preliminary findings show that further work is needed to develop a predictive model that can be utilized to stratify risk of epilepsy in those with seizures post-stroke. Funding: No funding was received in support of this abstract.