MRI evidence of past cerebral microbleeds in a healthy elderly population

Background: Incidental foci olf signal loss suggestive of past microbleeds are a frequent finding on gradient-echo T2(*)-weighted MRI of patients with nontraumatic intracerebral hemorrhage and have been associated with bleedi ng-prone microangiopathy. If and to what extent such lesions may also occur in the normal population is unclear. Objective: To determine focal hypoint ensities in asymptomatic elderly individuals and their relation to other cl inical and morphologic variables. Methods: T2(*)-weighted MRI of the brain was performed in a consecutive series of 280 participants (mean age 60 year s, range 44 to 79) of the Austrian Stroke Prevention Study. This cohort con sisted of randomly selected individuals without history or signs of neurops ychiatric disorder. Results: Past microbleeds ranging from one to five foci of signal loss were seen in 18 (6.4%) individuals. They were strongly asso ciated with higher age, hypertension, and lacunes (p < 0.001), and extensiv e white matter damage was more frequently noted (p = 0.02). Hypertension wa s present in all individuals with focal hypointensities in the basal gangli a and infratentorially but in only 5 of 10 volunteers with microbleeds limi ted to cortico-subcortical sites (p = 0.04). Conclusions: MRI evidence of p ast microbleeds may be found even in neurologically normal elderly individu als and is related, but not restricted, to other indicators of small vessel disease. The predictive potential of this finding regarding the risk of' i ntracerebral bleeding requires further investigation.