Improved MR imaging detection of cerebral microbleeds more accurately identifies persons with vasculopathy.

BACKGROUND AND PURPOSE: The clinical relevance of improved detection of cerebral microbleeds by using advanced-versus-conventional MR imaging techniques remains uncertain. As part of the population-based Rotterdam Scan Study, we compared whether participants whose microbleeds were only demonstrated on a high-resolution MR imaging sequence differed with respect to risk profile and risk of new microbleeds from participants whose microbleeds were also depicted on a conventional MR imaging sequence. MATERIALS AND METHODS: Two hundred participants (mean age, 79.2 years) underwent both conventional 2D T2*-weighted MR imaging and high-resolution 3D T2*-weighted MR imaging at 1.5T. Vascular risk factors, APOE allele status, and markers of small vessel disease and risk of incident microbleeds were compared for microbleed status by using logistic regression models adjusted for age and sex. RESULTS: There were no significant associations between any of the factors and microbleed presence in participants whose microbleeds were only demonstrated on a high-resolution MR imaging sequence. However, the estimates in these participants were more similar to those in participants whose microbleeds were also depicted on a conventional MR imaging sequence than to those in participants without microbleeds. Moreover, significantly more participants whose microbleeds were only demonstrated on high-resolution MR imaging developed new CMBs during follow-up compared with participants without CMBs (25.0% versus 5.9%; OR, 5.98; 95% CI, 1.35-26.49). CONCLUSIONS: Improved detection of microbleeds may contribute to more accurate identification of persons with underlying small-vessel pathology in the general elderly population. Further studies are needed to replicate these findings and firmly establish the role of improved detection of CMBs in the identification of persons with vasculopathy.

Cerebral microbleeds are associated with worse cognitive function: the Rotterdam Scan Study.

OBJECTIVE: Cerebral microbleeds are frequently found in the general elderly population and may reflect underlying vascular disease, but their role in cognitive function is unknown. METHODS: We investigated the association between cerebral microbleeds and performance in multiple cognitive domains in 3,979 persons without dementia (mean age, 60.3 years). Mini-Mental State Examination (MMSE) score and neuropsychological tests were used to assess global cognition and the following cognitive domains: memory, information processing speed, executive function, and motor speed. We used number of microbleeds as continuous variable, and additionally distinguished between persons with no microbleeds, 1 microbleed, 2-4 microbleeds, and ≥5 microbleeds. The association of microbleeds with different cognitive domains was estimated using linear regression models. Additional adjustments were made for vascular risk factors, brain atrophy, and other imaging markers of cerebral small vessel disease. We stratified analyses by location of microbleeds. RESULTS: A higher number of microbleeds was associated with lower MMSE score and worse performance on tests of information processing speed and motor speed. When analyzed per category, presence of 5 or more microbleeds was associated with worse performance in all cognitive domains, except memory. These associations were most robust in participants with strictly lobar microbleeds, whereas after additional adjustments associations disappeared for deep or infratentorial microbleeds. CONCLUSIONS: Presence of numerous microbleeds, especially in a strictly lobar location, is associated with worse performance on tests measuring cognitive function, even after adjustments for vascular risk factors and other imaging markers of small vessel disease. These results suggest an independent role for microbleed-associated vasculopathy in cognitive impairment.