Prevalence of epilepsy in the elderly: the Rotterdam Study

We assessed the prevalence of epilepsy in an elderly population in The Netherlands. The study was conducted from 1991 to 1993 as part of the Rotterdam Study, a population-based door-to-door study of all elderly people living in Ommoord, a suburb of Rotterdam, and included 5,559 persons aged 55-95 years. All subjects were screened for epilepsy through direct questions regarding the existence of epilepsy and antiepileptic drug (AED) use, in addition to relevant questions from the World Health Organization (WHO) protocol for epidemiologic studies of neurologic diseases. Further evaluation of screen positives was made by a panel of 1 study physician and 4 epileptologists, who also classified all confirmed cases of epilepsy according to the classifications of the International League Against Epilepsy (ILAE). The overall prevalence of active epilepsy in our study population was 0.9% including special syndromes and 0.8% excluding special syndromes. The prevalence increased with age from 0.7% for those aged 55-64 years to 1.2% for those aged 85-94 years. The increase with age was detected among men and women both. Our study confirms other findings showing that the prevalence of active epilepsy increases with age in the elderly. The prevalence figures in our study were high as compared with those of other population-based studies. Epilepsy appears to be a major cause of morbidity in the elderly.