Abstracts

Cerebrovascular disease is a well-recognized cause of late onset epilepsy, but the true frequency, risk factors and prognosis are not well established. We studied all consecutive patients with cerebrovascular disease and/or epileptic seizures who were seen in our department between January 2000 and June 2003. The diagnosis was established by history, clinical examination, EEG, laboratory findings, ultrasound studies and neuroimaging including MRI. Seizures were classified according to the international classification of epileptic seizures. Ischemic cerebrovascular disease was diagnosed in 1029 patients; 1114 patients had one or more epileptic seizures during the study period. Ischemic disease was identified as the cause of one or more seizures in 121 patients. Sixty-six patients (55%) had only one seizure, 55 patients (45%) went on to develop epilepsy with recurrent seizures during the observational period. In 71 patients the exact time span between the acute ischemic event and the first seizure could be determined. In 27% of patients the first seizure occurred within the acute phase of the cerebrovascular event (early seizures), in 73% of patients the first seizure occurred more than 2 weeks after cerebral ischemia (late seizures). Nearly 20% of patients with a major stroke had at least one seizure during the study period as opposed to only 5% after a transient ischemic attack (TIA) and 2% after a reversible ischemic neurologic deficit (RIND). Within the group of patients with cardiac emboli as pathogenic mechanism 13% of patients had one seizure and half of them developed epilepsy with recurrent seizures. Focal epileptogenic changes could be seen in the same number of patients with early or late seizures, but 95% of patients with cerebral ischemia and an epileptogenic focus had at least one seizure, 30% during the acute phase, 70% later during follow-up. High age at onset of cerebral ischemia and smoking as vascular risk factor lowered the risk for early or late seizures after stroke. In our present study, 12% of all patients with cerebral ischemia developed one or more seizures. The data emphazise a higher rate of seizures and epilepsy in patients with major stroke as compared to patients with transient ischemic events and in patients with focal epileptogenic changes at EEG. On the other hand, old age at onset of ischemia as well as smoking as vascular risk factor were associated with a lower risk of developing epilepsy after a cerebrovascular event. These results can have major therapeutic implications considering antiepileptic medication at an relatively early stage after stroke in patients at high risk for developing epilepsy after stroke.