Southern Buenos Aires stroke project

BACKGROUND: Ethnic differences and vascular risk factors are the major determinants of stroke subtypes. Nevertheless, specific data from undeveloped countries is difficult to obtain. Natives from South America may have a higher frequency of penetrating small vessel disease and hemorrhagic stroke. However, there are few studies in South America supporting these findings. OBJECTIVE: We analyze demographic, ethnic, risk factors, clinical characteristics, and stroke subtypes in all patients with acute stroke admitted to our hospital. METHODS: We studied all consecutive acute stroke patients admitted to the Ramos Mejia Hospital in Buenos Aires from 1997 to 1999. Our hospital serves a determined population of Southern Buenos Aires. Data were collected prospectively on patients' admission in a form especially designed for this study including vascular risk factors, clinical features, epidemiological characteristics, and neuroradiological findings. Stroke subtypes were determined according to the TOAST classification. RESULTS: Among 361 acute stroke patients, 31% had hemorrhagic stroke. It was more frequent among Natives (34%) than Caucasians (27%) (P<0.002). Ischemic stroke subtypes were as follows: 105 (42%) patients had lacunar, 31 (12%) atherosclerotic stroke, 53 (21%) cardioembolic infarction, and 16 (6%) other causes of stroke. Forty-five (18%) patients were classified as undetermined. Small vessel disease was higher among Caucasians (35%) than Natives (24%). CONCLUSIONS: Penetrating artery disease (42%) and intracranial hemorrhage (31%) were the most common stroke subtypes, being more frequent than reported in the literature. Natives had significantly higher frequency of hemorrhagic stroke than Caucasians.