Introduction

Epilepsy was first described as a clinical entity by Hippocrates (462–357 B.C.). In his monograph, ‘On the Sacred Disease’, he considered epilepsy a disease of the brain due to natural, rather than supernatural causes. In his other works, Hippocrates also described the various kinds of attacks, including convulsions and spells preceded by premonitory signs. He differentiated between ‘idiopathic’ and ‘symptomatic’ seizures and went on to describe the effects of various factors such as age, temperament, menstruation and seasonal changes on seizures. Many of these early writings still hold true today. Epilepsy is now recognized as a condition characterized by a tendency for recurrent seizures (defined as two or more spells) unprovoked by any immediate insult. In contrast, a seizure is defined as a paroxysmal disorder of the central nervous system associated with abnormal neuronal discharges.

It is estimated that approximately 1.5 million individuals have active epilepsy in the United States (Hauser & Hersdorffer 1990). From 70 000 to 128 000 new cases of epilepsy are reported each year. With the introduction of anticonvulsant medication, many patients with epilepsy have achieved better seizure control. Furthermore, the development of epilepsy surgery within the last decade has provided an alternative therapy for those individuals in whom seizures are intractable to medical treatment. As a consequence, the natural history of epilepsy has been altered significantly. Compared with the low remission rate of less than 30% in the early 1900s (Habermaas 1901; Turner 1907; Volland 1908), the overall prognosis of epilepsy has improved significantly one century later, with cure rates ranging from 50% to 80%.