Seizures and epilepsies after stroke

Epilepsies after stroke represent 20% of all adult-onset epilepsies and exhibit special characteristics with respect to diagnosis, treatment, and prognosis. Patients are frequently amnestic for their seizures the signs of which can be very subtle. Postictal pareses and confusional states can last for days, which further complicate diagnosis. Single seizures after stroke were reported in 2% to 10% of cases, and community-based studies found epilepsies in 3% to 4% of stroke patients. Analyses of subgroups identified epilepsy risks of 3% after ischemic infarction, 6% to 10% after intracerebral hemorrhage, and 9% after subarachnoid hemorrhage. Status epilepticus developed in less than 1% of stroke patients. Besides etiology, further risk factors for epilepsy comprise: remote seizures (latency > 2 weeks, risk of recurrence > 50%) more than early seizures (latency < 2 weeks, risk of recurrence < 50%), extent of stroke, cortical involvement, and degree of neurological deficit. The first appearance of seizures in patients older than 60 years represents a risk factor for future stroke with a hazard ratio of 2.89. There is currently no sufficient evidence for starting AED treatment before seizures occur. The benefit is still unclear of starting AED after a single early post-stroke seizure. Most authors recommend AED treatment after the second seizure but also after a first remote seizure because of the high risk of seizure recurrence in these situations. Possible pharmacokinetic interactions should be considered when choosing AED. Especially the first-generation AED carry the potential to interact with comedication, which is usually seen in stroke patients receiving substances such warfarin and salicylates. Only very few studies investigate specific AED exclusively in stroke patients. Lamotrigine and gabapentin have been successfully tested in these patients.