Epilepsy in the Tropics: I. Epidemiology, Socioeconomic Risk Factors, and Etiology

A large part of Asia, all of Africa, and most of Central and South America are located in the area between the tropics of Cancer and Capricorn, where more than a third of the world’s population live. The two most populous countries, China and India, are largely and wholly in this region, respectively. There is no doubt that epilepsy is a major problem in tropical countries, much more prevalent than in developed countries (1,2). The impact of geographic, climactic, demographic, social, and economic characteristics is adverse in terms of the frequency of epilepsy. Information is relatively limited (l), and actions have had to be based frequently on dramatic numbers such as a report that between 1983 and 1986, 60% of psychiatric outpatients and 30% of all psychiatric and neurologic cases in Malawi were related to epilepsy (H. Meinardi, personal communication, 1993), or on data indicating prevalence rates 2 to 25 times higher than the average prevalence of six per 1,000 in developed countries (3,4). The mandate of the Commission on Tropical Diseases of the International League Against Epilepsy is to advise the ILAE Executive Committee with respect to the various factors that contribute to the high frequency of epilepsy in the tropics. The focus of our attention is the study of causes, but socioeconomic and geographic influences are difficult to separate from environmental conditions that arise as their consequence. Examples are the possibilities that malaria is the commonest cause of fever in febrile convulsions; that perinatal and life-long head trauma are the commonest origins of epilepsy in children and adolescents; or that neurocysticercosis is the commonest cause of epilepsy in adults. These statements