Non-epileptic seizures of the elderly

To characterize non-epileptic seizures (NES) in the elderly and compare their features with NES of a younger control group.

The database of the epilepsy monitoring unit of the Cleveland Clinic Foundation (CCF) was searched for patients aged 60 years and older having undergone long-term video-/EEG monitoring between 1994 and 2002, with the subsequent diagnosis of NES. Videotapes of all events were evaluated by independent observers. NES were classified based on the clinical manifestations recorded on video, EEG and imaging data, and compared with a control group of younger adults with NES.

Thirty-nine elderly patients were included. Seventeen of them (44%) had NES only, six (15%) had both epilepsy and NES. The control group consisted of 20 patients, two of them had NES and epilepsy. The NES were classified as physiological in 10 elderly patients (43%) and one control patient. They included TIA, syncope, movement disorders and sleep disorders. Psychogenic NES were found in 13 elderly and 19 control patients and were associated with somatoform disorders, anxiety disorders, mood disorders and reinforced behavior pattern. Psychogenic NES consisted of predominant motor activity in 8 (61%) elderly and 13 (68%) control patients, unresponsiveness in 4 (31%) elderly and 2 (11%) control patients and subjective symptoms in 1 (8%) elderly and 4 (21%) control patients. Twelve (71%) of the patients of each group without evidence for epilepsy were on anticonvulsant drugs at the time of admission.

NES are a frequent problem in elderly patients referred to a comprehensive epilepsy center. In contrast to a younger control group, physiological and psychogenic NES are equally frequent in the elderly. Loss of responsiveness was seen in only 20% of patients with psychogenic NES. Although most of the patients did not have any evidence for epilepsy, more than two thirds of these patients had been placed on anticonvulsive drugs.