Etiology of seizures in the elderly.

Our study covered a 5-year period, and included all patients within a well-defined area who developed seizures after age 60 years. The dominant cause of seizures was a previous stroke, accounting for 32% of all cases. Tumors accounted for 14%, and the cause of seizures remained unknown in 25%. Seizures were recurrent in greater than 80% of patients with first seizure greater than 6 months after stroke. Fifteen of 21 patients with tumors had metastatic tumors. Of the six patients with primary brain tumors, five had malignant gliomas and one had a meningioma. We conclude that epilepsy with onset after age 60 years is more often symptomatic than is epilepsy in younger patients; since seizures were the first sign of a central nervous system (CNS) disease in half of the patients with brain tumors, careful investigation is necessary to reach a correct diagnosis.