Cerebral microbleeds are associated with widespread blood-brain barrier leakage.

INTRODUCTION: The pathogenesis of cerebral microbleeds (CMBs) is incompletely understood but blood-brain barrier (BBB) leakage may play a key role. This study aimed to investigate the relationship between compromised BBB integrity and CMBs as well as cognitive function.

METHODS: Ninety-seven participants were enrolled in this cross-sectional study, involving 24 CMBs patients. Dynamic Contrast-Enhanced (DCE)-Magnetic Resonance Imaging (MRI) was used to measure BBB permeability, and cognitive function was assessed by Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA).

RESULTS: Compared with participants without CMBs, CMBs patients had higher volume transfer constant (Ktrans, all P < 0.01) and area under the concentration curve (AUC, all P < 0.05) in normal-appearing white matter (NAWM), WMH, cortical gray matter (CGM) and deep gray matter (DGM). Multivariable linear regression analyses revealed that CMBs patients had significantly higher Ktrans in NAWM and AUC in NAWM, WMH and CGM after adjustment for age, sex vascular risk factors and cognitive scores. MMSE and MoCA scores decreased with increasing Ktrans in WMH and DGM as well as AUC in WMH after adjustment for age, sex, CMBs group and education length.

CONCLUSION: This study demonstrated that widespread BBB leakage was prevalent in CMBs patients, suggesting that compromised BBB integrity may play a key role in the pathogenesis of CMBs and could lead to cognitive impairment.