Positron emission tomographic study of postinfarction seizures

Positron emission tomography (PET), using the steady-state technique with (15)O, was performed in 18 patients 4-14 months after a thromboembolic stroke in the territory of the middle cerebral artery. Eight patients developed seizures 2-12 months after infarction. The patients with and without late-onset epilepsy were comparable according to age, etiology, and location of the stroke, and the degree of neurological deficit. PET examination showed a more pronounced decrease in regional cerebral blood flow (rCBF) and oxygen consumption (rCMRO2) in the infarcted area in the group with postapoplectic seizures compared to the nonepileptic stroke group. The PET findings were similar in the border areas of the infarcts and in the contralateral hemispheres of both groups. It cannot be determined if the more decreased rCBF and rCMRO2 in the infarcted zone of the group of patients with postinfarction epilepsy is the cause or the consequence of the seizures.