Prevalence and risk factors of silent brain infarcts in the population-based Rotterdam Scan Study

Background and Purpose-Silent brain infarcts are commonly seen on magnetic resonance imaging (MRI) both in patients with a first stroke and in healthy elderly persons. These infarcts seem associated with an increased risk of stroke. It is unclear whether risk factors for silent infarcts differ from those for symptomatic stroke. We investigated the prevalence of, and cardiovascular risk factors for, silent brain infarcts. Methods-The Rotterdam Scan Study is a population-based cohort study among 1077 participants 60 to 90 years of age. Participants underwent cerebral MRI. We assessed cardiovascular risk factors by interview and physical examination. Associations between risk factors and presence of infarcts were analyzed by logistic regression and adjusted for age, sex, and relevant confounders. Results-For 259 participants (24%) 1 or more infarcts on MRI were seen; 217 persons had only silent and 42 had symptomatic infarcts. The prevalence odds ratio (OR) of both silent and symptomatic infarcts increased with age by 8% per year (95% CI, 1.06 to 1.10 and 1.04 to 1.13, respectively). Silent infarcts were more frequent in women (age-adjusted OR, 1.4; 95% CI, 1.0 to 1.8). Hypertension was associated with silent infarcts (age- and sex-adjusted OR, 2.4; 95% CI, 1.7 to 3.3), but diabetes mellitus and smoking were not. Conclusions-Silent brain infarcts are 5 times as prevalent as symptomatic brain infarcts in the general population. Their prevalence increases with age and seems higher in women. Hypertension is associated with silent infarcts, but other cardiovascular risk factors are not.