Epidemiology of epilepsy

Prevalance and incidence figures for epileptic seizures vary greatly throughout the world. At present, the minimal prevalence rate is generally estimated as 4 to 6 per 1,000. Occurrence is great enough to constitute serious medical, economic and social problems. Prevalence and incidence rates vary according to definition of a case and a precise definition must be given for the rate to be meaningful. The World Health Organization is attempting to produce general agreement on terminology so that accuracy and comparability of primary data among investigators may be obtained. Current prevalence rates are based only on those cases of active recurrent epileptic seizures with or without medical treatment. It is proposed that information about prevalence be obtained for 3 other types of individuals: those who at some time in their life have experienced seizure of any origin; those in whom epileptic seizures are completely controlled for long periods of time with medication; and those who have outgrown or have stopped having epileptic seizures. These figures will be useful for planning diagnostic and treatment facilities, for providing remedial services for those who have suffered educational or social deprivation as a result of having had epileptic seizures, and as a measure of the efficacy of currently available treatment regimens.