Description of stroke subtypes and known associated risk factors among adult stroke patients at mulago hospital.

Abstract

BACKGROUND: Stroke is the second commonest cause of morbidity and mortality worldwide after ischemic heart disease. Despite the high morbidity and mortality, there is limited data on the stroke subtypes and known associated risk factors among stroke patients in sub-saharan Africa. We studied the known stroke associated risk factors in relation to stroke subtypes among adult stroke patients in Uganda. PRIMARY OBJECTIVES: The objectives of the study were to determine the frequency of stroke subtypes and describe the distribution of known stroke associated risk factors among adult stroke patients at mulago hospital emergency and general medical wards. METHODOLOGY: A Cross sectional descriptive study among all patients with diagnosis of stroke presenting to the emergency and general medical wards at mulago hospital during the period July to November 2006 was conducted. A brain CT scan was performed to confirm stroke and classify the subtypes. Patients with confirmed stroke were interviewed using a pre-tested standardized data-collection tool on selected social demographics and clinical characterisitics. Laboratory tests, Doppler ultrasound of the carotid arteries and transthoracic echocardiography were also done to assess known risk factors associated with stroke using a verified questionnaire adopted from the American stroke association. RESULTS: Out of 85 patients with stroke confirmed on brain CT scan, (n=66, 77.6%) had ischaemic stroke and (n=19, 22.4%) had haemorrhagic stroke. The mean age for all strokes was 62 years, 52.8% were men. Atherosclerotic stroke (n=32, 48.5%) was the most common ischemic stroke subtype while intracerebral (Intraparenchymal) hemorrhage (n=10, 52.6%) was the commonest hemorrhagic stroke sub type. The following factors were inversely associated with the risk of ischemic stroke. Family history of diabetes mellitus decreased risk by 0.65-0.85 fold, total cholesterol>_ 240mg/dl by 0.65-0.85 fold and reactive TPPA by 0.30 fold. Where as systolic BP>_ 140mmHg increased the risk of ischemic stroke 3.16 fold and diastolic BP>_ 90mmHg increased the risk of ischemic stroke 3.70 fold. The only known stroke associated risk factor that was independently associated with ischemic and hemorrhagic stroke was a diastolic blood pressure>_ 90mmHg (P value 0.027). About a third of patients presenting with signs and symptoms of stroke have an alternative diagnosis (using brain CT scan as a gold standard). CONCLUSIONS: At mulago hospital, ischemic stroke predominates over hemorrhagic stroke in ratio of 3:1. The risk factor profiles of stroke subtypes differ. Family history of diabetes mellitus, total cholesterol >_ 240mg/dl and a reactive TPPA decreased the risk of ischemic stroke compared to hemorrhagic stroke whereas systolic BP>_ 140mmHg and diastolic BP>_ 90mmHg increased the risk of ischemic stroke compared to hemorrhagic stroke. RECOMMENDATIONS: Aggressive monitoring and treatment of hypertension is one of the main targets in primary health care, however further studies are needed to evaluate the risks of raised serum total cholesterol levels, a positive treponema pallidum precipitation test and family history of diabetes mellitus among patients with stroke at Mulago Hospital. Although clinical evaluation may be cost effective in management of stroke, brain CT scan is recommended for accuracy in diagnosis and appropriate management.