A meta-analysis of association between cerebral microbleeds and cognitive impairment

The clinical effect of cerebral microbleeds (CMBs) on cognition has been receiving much research attention, but results are often inconsistent. We searched PubMed, Embase, Web of Science, and some Chinese electronic databases. A total of 15 studies were included. 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]). 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.