A Prospective Study of Stroke Sub-Type from Within an Incident Population in Tanzania (Original Articles) (Report)
Stroke is an increasingly important cause of premature death and chronic disability in many low- and middle-income countries. (1) Worldwide, strokes resulting from ischaemia are much more common than those due to cerebral haemorrhage. A study of 3 000 hospitalised first-in-a-lifetime stroke patients across 22 countries found that overall 22% of strokes were due to cerebral haemorrhage and 78% to ischaemia. (2) The percentage due to cerebral haemorrhage was lowest in high-income countries, where 9% were due to cerebral haemorrhage and 91% to ischaemia. Sites in Africa (Mozambique, Nigeria, South Africa, Sudan and Uganda) had the highest percentage of strokes due to cerebral haemorrhage, at 34%. In Europe and North America, studies have suggested rates of 10 20% for stroke due to cerebral haemorrhage. (3-5) Data on stroke subtype in sub-Saharan Africa (SSA) are much less reliable, with rates of 29-57% reported for cerebral haemorrhage. (6-9) This variability in the incidence of stroke sub-types, both within SSA and between SSA and high-income countries, may partly be due to the low numbers in these studies, lack of access to computed tomography (CT) scanning equipment, and the fact that all were hospital-based. In SSA, because of limited resources, often only patients with more severe symptoms are admitted to hospital. Such patients are likely to have had a stroke due to cerebral haemorrhage rather than an ischaemic stroke. In SSA neuro-imaging devices are often not available or too expensive for routine use, and the diagnosis of stroke sub-type is usually made clinically. (10) Nevertheless, clinicians must know the type of stroke that has occurred to avoid administration of anticoagulant, antiplatelet or thrombolytic agents to patients who have had a cerebral haemorrhage.