[Epidemiology and risk factors in stroke].

Epidemiology focuses on frequency and distribution of diseases and their relevant risk factors. Epidemiologic data are the basis for development of therapeutic strategies, evaluation of prevention and rehabilitation. Stroke in terms of epidemiology includes ischemic brain infarction as well as intracerebral and subarachnoidal hemorrhage. Stroke is most prominent in the elderly with an annual incidence of about 3%. Stroke prevalence varies between 5 and 8%. The 1-year case fatality is about 42%. The mortality rate varies considerably between 20 and 80 per 100 000 in comparable populations in Europe. Hypertension, smoking and atrial fibrillation are the most prominent risk factors; diabetes and the elevated serum cholesterol also contribute.