Post-stroke epilepsy in an ischemic stroke cohort-Incidence and diagnosis

Stroke is a common cause of adult-onset epilepsy (post-stroke epilepsy, PSE). Despite an increasing awareness, there is a concern for underdiagnosis of the condition. We aimed to study the adherence to the latest updated epilepsy definition, as well as the incidence and diagnosis of PSE in an ischemic stroke cohort admitted to a tertiary University Hospital.

We retrospectively investigated the occurrence and diagnosis of unprovoked seizures and PSE in all ischemic stroke patients admitted to Karolinska University Hospital in Stockholm during 2015 and registered in the Swedish Stroke Register. Patient records were scrutinized for the presence of post-stroke seizures/epilepsy.

A total of 240 patients fulfilling the inclusion criteria were surveyed. Median follow-up time was 1062 days (IQR 589-1195 days). Thirteen patients were diagnosed with PSE according to the study criteria, the incidence of PSE 23/1000 person-years (95% CI 13-38/1000 person-years). Median time to PSE from stroke-onset was 237 days (IQR 33-688). Eleven of 13 PSE patients received an epilepsy diagnosis, eight patients after one unprovoked seizure, and three patients after two.

The majority of PSE patients were given a correct epilepsy diagnosis and treated with antiepileptic drugs. However, this study suggests that there still is potential for improvement in the adherence to the latest updated epilepsy definition. The incidence of PSE in a Swedish ischemic stroke cohort using updated epilepsy definitions is similar to previous studies. Larger studies are needed to confirm our findings on the incidence of PSE.