Post-stroke epilepsy

Stroke is the most common cause of seizures and epilepsy in population stuies of adults. Seizures occur within 24 hours of the stroke in a high percent of patients. The pathogenesis of these early-onset seizures may be related to local ion shifts and release of high levels of excitotoxic neurotransmitters in the area of ischemic injury. The risk of late-onset seizures may increase over time, an underlying permanent lesion that leads to persistent chnges in neuronal excitability appears to be responsible for late-onset seizures after stroke. The most consistently identified risk factors for acute and late post-stroke seizures are stroke severity and cortical location. Most seizures following stroke are focal at onset, but secondary generalization is common, particularly in patients with late-onset seizures. Status epilepticus is relatively uncommon. The efficacy of antiepileptic drugs for these post-stroke seizures has not been rigorously assessed in controlled trials, although most seizures can be controlled with a single agent. Given the relatively low frequency of recurrent seizures after stroke, and an absence of absolute predictors of poststroke epilepsy, the decision of when to treat patients for a post-stroke seizure is difficult.