Abstracts

Rationale: The epilepsies are one of the common serious neurological disorders and can occur at all ages. The incidence in childhood has fallen over the recent decade in developed countries, but the incidence in elderly has been increasing. Several studies report the incidence of epilepsy in specific age groups in the past. The incidence in the elderly varies significantly because of the difference of definitions, number of the patients and institutions. Here in order to see our incidence of epilepsy in the elderly in Japan, we studied and analyzed the incidence of new onset geriatric epilepsy with the background neurological diseases in an epilepsy center where we manage general epileptic patients with epileptic surgery for intractable cases. Methods: More than 2 unprovoked seizures or loss of consciousness(LOC) with good description from observers or EEG evidence of epilepsy, were collected from 275 patients with the probable diagnosis of epilepsy from 2001 to 2008 in our center. Results: Result: Among 275 cases, the number of patients with real epilepsy according to the definition was 193 cases. Seizure onset after the age 60 years was defined as new onset geriatric epilepsy in this series. 43 patients out of 193 cases were elderly epileptics with 24 men and 19 women. They all had symptomatic localization-related epilepsies with or without secondary generalization. The incidence of geriatric epilepsy is 22.3% among epileptics in all ages. Each decade incidence was 8.80%, 4.66%, 6.73% and 2.07% according to the age decade from 60-69, 70-79, 80-89 years old, and older than 90 years old respectively. The background neurological diseases responsible for epilepsy was analyzed. 16 patients(9 men; 7 women) out of 43 cases(37.3%) developed a focal seizure after stroke, 9 patients (3 men;6 women) with Alzheimer's disease(20.9%) , 9 cases (6 men; 3 women) with brain tumor(20.9%) and 4 cases (3 men; 1 women) after head trauma(9.3%), and 4 patients with various CNS diseases such as viral encephalitis, metabolic disorder, granulomatous angitis of nervous system(GANS) and drug-induced seizures in patients with schizophrenia. One patient had epilepsy of unknown cause. Conclusions: Most epidemiological studies of the epilepsy incidence conducted in industrialized countries is lowest during the adult years, but the incidence after 60 years old is rather high even comparing with the incidence in early childhood. A report from England showed that almost 25% of newly diagnosed seizures occurred in patients aged 60 years and older (Sander JW et al:1990). Our incidence coincide with their data. The most common associated neurological disorder in our series is CVA including ischemic stroke and hypertensive intracerebral hemorrhage, followed by Alzheimer’s disease(AD), brain tumor and head trauma in reducing orders. High incidence of dementia from AD for the risk factor is remarkable. Increasing number of dementia in the elderly will account for the future increase of geriatric epilepsy due to various neurogedegenerative disorders and the management strategies should be seriously considered.