Natural history of epileptic seizures.

Since 1963 a continuous registration of patients with epileptic seizures has been carried out in Greater Aarhus, Denmark. This registration has been attempted by means of medical records dating back to 1940. On the basis of the established prevalence and the calculated cumulated incidence, we have tried to describe the natural history of the different types of epilepsy. The prevalence of all types of epileptic seizures (including febrile convulsions) has been found to be 2,441/100,000, whereas for patients with the diagnosis of epilepsy the rate is 1,274/100,000. The study describes the natural history of the different types of epilepsy. In addition, the risk-increasing effect of a febrile convulsive seizure on the development of epilepsy is analyzed.