Stroke in the Africans.

Stroke is increasingly becoming a major cause of death and morbidity in African population among most of which the frequencies of hypertension are considerable, although hard data based on community surveys are lacking and most of the information available is from hospital data. The epidemiology of stroke in the Africans is reviewed. The frequencies in hospital populations varied from 0.9% to 4.0% and stroke accounted for 0.5% to 45% of neurological admissions. There is male predominance in published series. The main risk factors are hypertension, diabetes mellitus and homozygous sickle cell disease (in children only). Ischaemic stroke is by far the commonest clinical type encountered. These conclusions are further supported by experience at Ibadan, of over 1100 Africans seen over 18 years reported briefly in this communication. The results of the first community study over a 2-year period on the incidence of stroke in an African Urban (Ibadan) Community are presented. The study was carried out as part of a multinational multicentric study initiated and sponsored by the World Health Organization. The male to female ratio was five to two. Incidence rates reached peaks in the eighth decade in males and in seventh decade in females and were higher in males in all age groups, and the rates are comparable with those recorded in European populations, except in those under the age of 40 in Ibadan, in which age-specific incidence rates are considerably lower than in European and Japanese populations. Hypertension, diabetes mellitus constituted the main risk factors. Mortality and recurrence rates are described and are similar to experience in the Caucasians. Hypertension in the Nigerians predispose to a high frequency of cerebrovascular disease other than through mainly cerebral atherosclerosis. With increasing longevity of Nigerians and other Africans, the mortality and morbidity caused by cerebrovascular disease would probably become of enormous dimensions and adequate control of high blood pressure on a community basis may be the only way of preventing this: this would be desirable as myocardial infarction in contradistinction to hypertensive heart disease is an uncommon complication of high blood pressure in the Africans and prevention of hypertensive heart disease as shown by experience elsewhere can be achieved by control of high blood pressure, which does not seem to prevent ischaemic myocardial disease.