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 (K-trans, 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 K-trans 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 K-trans 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.