Coexistence of cerebral microbleeds and amyloid pathology in patients with cognitive complaints

Background and Purpose We investigated the prevalence of amyloid positivity and cerebral microbleeds (CMBs) in subjects with cognitive complaints with the aim of identifying differences in clinical parameters and cognitive function according to the pattern of coexistence. Methods We retrospectively enrolled 200 subjects with memory impairment and applied both standardized¹⁸F-florbetaben PET and brain MRI, including susceptibility-weighted imaging. The amyloid burden was visually classified as positive or negative, and the number and location of CMBs were also analyzed visually. Descriptive analysis was performed for the prevalence of amyloid positivity and CMBs. The relationship between the coexisting pattern of those two findings and clinical parameters including the results of neuropsychiatric tests was analyzed. Results Positive amyloid PET scans were exhibited by 102 (51.5%) of the 200 patients, and 51 (25.5%) of them had CMBs, which were mostly located in lobar areas in the patients with positive amyloid scans. The patients with CMBs were older and had a higher burden of whitematter hyperintensities than the patients without CMBs. The patients with CMBs also performed worse in confrontation naming and frontal/executive function. When classified by topographical region, parietal CMBs (odds ratio=3.739, p=0.024) were significantly associated with amyloid positivity. Conclusions The prevalence of CMBs was higher in patients with cognitive decline than in the general population. CMBs play distinctive roles in affecting clinical parameters and neuropsychological profiles according to the coexistence of amyloid pathology.