Seizures after cerebrovascular events: risk factors and clinical features

Epileptic seizures are well known sequelae of patients with stroke but only little is known about the different risk factors and about the influence of the different types of stroke including sinus thrombosis and bleedings on developing such seizures. Further, the association of post-stroke seizures and conventional vascular risk factors has not been evaluated to date.

We performed a cohort study on a sample of 593 consecutive patients with different types of cerebrovascular events. In 421 patients, sufficient data were obtained in a personal interview over a mean observation period of 30 months. Data regarding the clinical history were recorded from the patients' charts.

The total prevalence of epileptic seizures was 11.6%, the total annual risk was 4.6%. We detected the following significant risk factors: younger age at stroke; higher NIH stroke scale score; any coagulopathy. TIA was found significantly less frequent as a cause of seizures as compared to infarction, bleeding, and sinus thrombosis. Patients with bleeding (14.3%) and with sinus thrombosis (16.3%) were significantly more frequent in the seizure group than in the non-seizure group (6.7% and 1.6%, respectively). The location of stroke, including cortical versus subcortical, did not influence the risk of seizures. The majority of patients developed secondary generalized seizures (57.1%). In adjusted analyses, the two major risk factors for post-stroke epilepsy were a higher NIH stroke scale and a sinus thrombosis as the initial cerebrovascular event. Common lifestyle, vascular, and metabolic risk factors of stroke and for dementia were not associated with the development of seizures.

In conclusion, our data show that epileptic seizures occur in particular after major strokes and in sinus thrombosis. Interestingly, conventional vascular risk factors were not associated with the occurrence of post-stroke seizures. Considering the risk for seizures after certain types of cerebrovascular events might help to early identify patients for anticonvulsive treatment. In the future, it should be investigated whether these patients might benefit from pre-emptive anticonvulsant treatment.