Late seizures following a first symptomatic brain infarct are related to large infarcts involving the posterior area around the lateral sulcus

Controversies exist concerning factors that contribute to the occurrence of epileptic seizures after stroke. Therefore, we studied prospectively the occurrence of seizures in 322 patients with a first-ever CT-confirmed symptomatic territorial brain infarct involving the cortex. We also studied potential risk factors for seizures, and gave special attention to cortical infarct location. Fifty-four patients developed post-stroke seizures. We distinguished between early- and late-onset seizures, occurring within two weeks following stroke-onset, or later than two weeks, respectively. We found that patients of 65 years or older with a cardioembolic brain infarct involving the middle temporal or post-central gyrus, had an almost eight times increased risk of early-onset seizures, whereas patients with a large brain infarct involving the supramarginal or superior temporal gyrus, had a five times increased risk of late-onset seizures. We conclude that risk factors and epileptogenic cortical areas for post brain infarct seizures can be identified, which however, differ between early- and late-onset seizures. These two seizure types may also differ in terms of seizure mechanism. Our findings may influence the decision on prophylactic treatment with antiepileptic drugs in stroke patients.