A Meta-Analysis of Association between Cerebral Microbleeds and Cognitive Impairment

BACKGROUND: The clinical effect of cerebral microbleeds (CMBs) on cognition has been receiving much research attention, but results are often inconsistent. MATERIAL/METHODS: We searched PubMed, Embase, Web of Science, and some Chinese electronic databases. A total of 15 studies were included. RESULTS: Patients with CMBs had higher incidence of cognitive dysfunction (OR 3.14; 95% CI 1.66–5.92) and lower scores of cognitive function (SMD was −0.36 [−0.55, −0.18] in the MMSE group and −0.65 [−0.99, −0.32] in the MoCA [Montreal Cognitive Assessment] group). The results also indicated that a higher number of CMB lesions led to more severe cognitive dysfunction (SMD was −2.41 [−5.04, −0.21] in the mild group and −2.75 [−3.50, −2.01] in the severe group). We also found that cognitive performance was significantly impaired when CMBs were located in deep (−0.4 [−0.69, −0.11]), lobar regions (−0.50 [−0.92, −0.09]), basal ganglia (−0.72 [−1.03, −0.41]), and thalamus brain regions (−0.65 [−0.98, −0.32]). CONCLUSIONS: This meta-analysis showed that CMBs were associated with cognitive dysfunction according to higher number and different locations of CMBs. Future work should focus on long-term prognosis of continuing cognitive decline and specific treatments to reduce the formation of CMBs.