Stroke before 55 years of age at Karolinska Hospital 1973-77. A study of 399 well-defined cases. Risk indicators and etiological considerations.

The etiological characteristics of cerebrovascular disease (CVD) before the age of 55 are reviewed in 399 patients admitted to the Department of Neurology, Karolinska Hospital, Stockholm, from 1973-77. The material was well-defined with regard to subtypes of stroke as well as to the diseased population. The control material consists of 829 males and females of corresponding age randomly selected from the Stockholm population. In the ischemic group, 61% had angiographic evidence of atherosclerosis and, compared to controls, in most patient groups a significant (P less than 0.05-0.001) association with hypertension, diabetes, heart disease and smoking was found as well as for female patients under age 40 the use of oral contraceptives (P less than 0.001). In the hemorrhagic group, angiography demonstrated aneurysms in 76% of the patients with subarachnoidal bleeding but also atherosclerotic lesions in about 12% of the whole group. This would imply that atherosclerosis is an important precursor also for hemorrhagic lesions, further supported by a significant (P less than 0.01-0.001) association of hypertension, diabetes and smoking with this group.