Basal Ganglia Cerebral Microbleeds and Global Cognitive Function: The Kashima Scan Study

Background: We previously showed that global cognitive function was associated with deep or infratentorial (D/I) cerebral microbleeds (CMBs) in a Japanese healthy cohort. We continually recruited participates and performed further investigation to focus on the impact of different distributions of D/I CMBs on gradient-echo magnetic resonance imaging on global cognitive function. Methods: A total of 1392 subjects including subjects without CMBs (n = 1335), with D/I CMBs limited to the basal ganglia (BG; BG group, n = 33), thalamus (thalamus group, n = 14), and infratentorial area (infratentorial group, n = 10) were included in analyses. Subjects with strictly lobar CMBs (n = 43) were excluded, but subjects in the BG, thalamus, and infratentorial groups could also have lobar CMBs. The mini-mental state examination (MMSE) was administered to determine global cognitive function; scores less than 27 or more than 1.5 standard deviations (SDs) below the age-education-related mean were regarded as impaired. Results: In the multivariable logistic regression analyses, hypertension and severe white matter hyperintensities were associated with the BG group and the thalamus group. In multivariable logistic regression analysis of the association between D/I CMBs classification and impaired MMSE score, only the BG group consistently displayed associations with both MMSE score less than 27 (odds ratio [OR], 5.96; 95% confidence interval [CI], 2.08-17.09) and MMSE score more than 1.5 SDs below the age-education-related mean (OR, 3.34; 95% CI, 1.24-8.99). In the BG group, adjusted mean scores of total MMSE and "attention and calculation" were lower compared with subjects without CMBs. Conclusions: In our study of D/I CMBs, only BG CMBs have strong association with global cognitive function. This association was independent of CMBs in other location.