Association of Cerebral Microbleeds with Cognitive Decline: A Longitudinal Study

Abstract

BACKGROUND: The role of cerebral microbleeds (CMBs) in cognitive impairment remains controversial. OBJECTIVE: To investigate the possible links between the presence, progression, number, and location of CMBs and cognition. METHODS: We assessed 792 subjects from the Alzheimer's Disease Neuroimaging Initiative who underwent both brain 3 Tesla MRI scans and cognitive testing. The association between CMBs and cognitive change was explored using linear mixed-effects models (LME). RESULTS: Presence and number of CMBs were associated with memory (β= -0.03, p = 0.015; β= -0.01, p = 0.003), executive function (β= -0.04, p = 0.010; β= -0.01, p = 0.014), and global cognitive function (β= -0.06, p = 0.025; β= -0.03, p < 0.001). Progression of CMBs showed significant negative associations with executive function (β= -0.05, p = 0.025) and global cognitive function (β= -0.12, p = 0.015). The relations with cognitive performance (memory, executive function and global cognitive function) were mainly driven by lobar CMBs (β= -0.03, p = 0.041; β= -0.04, p = 0.010; β= -0.07, p = 0.029, respectively), especially those located in temporal lobe (β= -0.08, p = 0.027; β= -0.13, p = 0.001; β= -0.26, p < 0.001, respectively). Furthermore, white matter hyperintensities may mediate the association between CMBs and cognition. CONCLUSION: The presence, progression, number, and location of CMBs, especially those located in temporal lobe, are associated with cognitive decline. These findings suggest CMBs play a role in cognitive impairment.