Cerebral microbleeds (CMBs) in the lobar and deep locations are associated with two distinct pathologies: cerebral amyloid angiopathy and hypertensive arteriopathy. However, the role of mixed-location CMBs in neurodegeneration remains unexplored. We investigated the associations between strictly lobar, strictly deep and mixed-location CMBs with markers of neurodegeneration. This study recruited 477 patients from a memory clinic who underwent 3T MRI scans. CMBs were categorized into strictly lobar, strictly deep and mixed-location. Cortical thickness, white matter volume and subcortical structural volumes were quantified using Free-Surfer. Linear regression models were performed to assess the association between CMBs and cerebral atrophy, and the mean difference (β) and 95% confidence intervals (CIs) were reported. In the regression analyses, mixed-location CMBs were associated with smaller cortical thickness of limbic region [β=-0.01; 95% CI=-0.02,-0.00, p=0.007) as well as with smaller accumbens volume [β=-0.01; 95% CI=-0.02,-0.00, p=0.004) and presubiculum region of hippocampus [β=-0.01; 95% CI=-0.02,-0.00, p=0.002). Strictly lobar CMBs were associated with smaller total white matter volume [β=-0.03; 95% CI=-0.04,-0.01, p<0.001] and with region specific white matter volumes. The underlying mechanism requires further research and may involve shared mechanisms of vascular dysfunction and neurodegeneration.

Additional Metadata
Keywords Hypertensive arteriopathy, Memory clinic, Mixed-location microbleeds, Neurodegeneration
Persistent URL dx.doi.org/10.18632/aging.102478, hdl.handle.net/1765/122416
Journal Aging
Gyanwali, B. (Bibek), Shaik, M.A. (Muhammad Amin), Tan, C.S. (Chuen Seng), Vrooman, H.A, Venketasubramanian, N, Chen, C. (Christopher), & Hilal, S. (2019). Mixed-location cerebral microbleeds as a biomarker of neurodegeneration in a memory clinic population. Aging, 11(22), 10581–10596. doi:10.18632/aging.102478