Late onset epilepsy. A prospective study.

253 cases of late onset epilepsy were studied prospectively. 27 cases (10.7%) had space-occupying lesion, 19 cases (7.5%) had cerebrovascular disease, 13 cases (5.1%) cerebral cysticercosis and 4 cases (1.6%) had diffuse cerebral atrophy. No cause could be detected in 190 cases (75.1%). Analysis of clinical data and radiological studies showed that a majority (85%) of patients with 'tumour' who presented with epilepsy had focal neurological deficit and/or papilloedema. Focal slow-wave abnormality in EEG also gave an indication of an organic lesion. Patients who had epilepsy for more than 1 year, infrequent attacks and partial complex seizures, were less likely to have a tumour. The role of careful clinical examination is stressed.