Age-specific prevalence of epilepsy in Oppland County, Norway

Objective –  To assess the prevalence of epilepsy in Oppland County, Norway, particularly with respect to age. Materials and methods –  Population-based and hospital-based approaches were used to identify individuals with active epilepsy born in 1925, 1940, 1955, 1960 and 1970. Cases with active epilepsy were defined as individuals who had experienced more than one epileptic seizure during the last 5 years and/or were taking antiepileptic drugs. Results –  From a population of 11,089 persons, 90 individuals were identified with active epilepsy. The age-distributed prevalence (cases per 1000 individuals born in a specified year) of active epilepsy was 10.2 for those born in 1925, 11.1 for those born in 1940, 4.5 for those born in 1955, 7.5 for those born in 1960 and 9.4 for those born in 1970. Mean epilepsy prevalence was estimated to be 8.2 cases/1000 inhabitants. Conclusions –  An epilepsy prevalence of 8.2 cases/1000 inhabitants is in accordance with the results of similar studies from the western world. However, the results of such studies will vary according to the definition of ‘active epilepsy’. By using the narrower International League Against Epilepsy’s definition, the prevalence in our study is reduced to 5.3 cases/1000 inhabitants.