Cerebral microbleeds in a multiethnic elderly community: Demographic and clinical correlates

Abstract

Background Microbleeds, small perivascular collections of hemosiderin manifested radiologically as hypointensities on gradient-echo magnetic resonance imaging (MRI), are important markers of small vessel pathology. Despite their clinical relevance, little is known about their prevalence and demographic correlates, particularly among ethnically diverse older adults. We examined demographic and clinical correlates of regional microbleeds in a multi-ethnic cohort and examined categorization schemes of microbleed distribution and severity. Methods Between 2005 and 2007, 769 individuals participated in a MRI study as part of the Washington Heights/Inwood Columbia Aging Project. Approximately four years later, 243 out of 339 participants (mean age=84.50) who returned for a repeat MRI had gradient-echo scans for microbleed assessment and comprised the sample. We examined the association of deep and lobar microbleeds with age, sex, education, vascular factors, cognitive status and markers of small vessel disease. Results Sixty-seven of the 243(27%) participants had at least one microbleed. Individuals with microbleeds were more likely to have a history of stroke than individuals without. When categorized as having either no microbleeds, microbleeds in deep regions only, in lobar regions only, and both deep and lobar microbleeds, hypertension, proportion of strokes, and white matter hyperintensity volume (WMH) increased monotonically across the four groups. Number of lobar microbleeds correlated with WMH volume and diastolic blood pressure. Conclusions Microbleeds in deep and lobar locations are associated with worse outcomes than microbleeds in either location alone, although presence of lobar microbleeds appears to be more clinically relevant.

Lobar Microbleeds Are Associated with a Decline in Executive Functioning in Older Adults

“…Individuals with 2 or more lobar microbleeds had an accelerated rate of speed/executive function decline over the 9-year period preceding the MRI scan relative to individuals with fewer than 2 microbleeds. Unsurprisingly and as we have reported previously (Wiegman, et al, 2014), individuals with more than 2 microbleeds also had increased evidence of ischemic cerebrovascular disease (i.e., WMH and infarct).…”

“…Beginning in 2009, participants with initial MRI scans were invited for a follow-up MRI scan, leading to a total of 339 subjects with repeat MRI; 243 of the 339 had T2*-weighted gradient echo (GRE) scans for microbleed assessment (Wiegman et al, 2014). For the current analysis, we examined cognition data starting in 1999 and excluded subjects meeting clinical criteria for dementia at the time of the GRE MRI scan (N=46), resulting in a sample of 197 subjects (mean age: 84.15+/− 5.02 years) that comprised the study group reported here.…”

“…As previously described (Wiegman, et al, 2014), total white matter hyperintensities (WMH) volumes were calculated for concurrent MRI scans and presence of radiological infarcts was evaluated at the subjects’ baseline MRI scan.…”

Neuroimaging Correlates of Cerebral Microbleeds

“…18, 19 In the ARIC study, no significant difference in risk of CMB presence or location were detected by race. Two prior racially and ethnically diverse studies on CMBs revealed no difference in CMB frequency between black, white and Hispanic individuals 20, 21 . Despite the association of CMBs with imaging markers of small-vessel disease, diabetes was not associated with CMBs in the present study or in the Framingham or Rotterdam studies.…”

Prevention of Stroke in Patients With Silent Cerebrovascular Disease: A Scientific Statement for Healthcare Professionals From the American Heart Association/American Stroke Association

“…81,84 Prevalence was similar in a multiethnic cohort, the Washington Heights-Inwood Columbia Aging Project. 86 Technical and measurement-related factors may influence CMB prevalence rates. Most important, MRI parameters such as longer echo time, smaller interslice gap, and the use of 3-dimensional acquisition, a higher magnetic field, and newer sequences such as susceptibility-weighted imaging can increase the ability to detect microbleeds by 2-to 3-fold.…”