Neurocysticercosis as the main cause of late-onset epilepsy in Mexico.

We studied 100 consecutive Mexican patients with epilepsy that started after the age of 25 years. All patients underwent clinical evaluation, computed tomography, and electroencephalography; additionally, cerebrospinal fluid analysis was performed in 82 of them. Neurocysticercosis or its sequelae were diagnosed in 50 patients (50%); 36 of these patients had partial seizures, 41 had parenchymal calcifications, and 15 had two or more lesions. Our results are in contrast with those of most studies from countries with a low incidence of neurocysticercosis, where brain tumors, cerebrovascular disease, trauma, and alcoholism are the main causes of tardive epilepsy.