Glymphatic function, deep medullary veins, and cognitive impairment in cerebral small vessel disease: A mediation...

The glymphatic system and deep medullary veins (DMV) are closely linked to cognitive impairment in patients with cerebral small vessel disease (CSVD). This study aims to elucidate these complex associations through mediation analysis.

Patients who underwent multimodal magnetic resonance imaging (MRI) scans and the Montreal Cognitive Assessment (MoCA) were recruited. Glymphatic function was assessed using the diffusion tensor imaging along the perivascular space (DTI-ALPS) index. DMV was identified on susceptibility-weighted imaging (SWI), and a total DMV score was calculated based on segmental continuity and visibility. Regression models were employed to estimate the impact of the DMV score and DTI-ALPS index on cognitive impairment. Mediation analysis was conducted to examine the effect of the DTI-ALPS on DMV score and cognitive function.

A total of 152 participants were included, of whom 65 had normal cognitive function and 87 had cognitive impairment. After adjusting for confounding factors, both the DMV score (OR=1.182, 95 % CI: 1.067-1.308, p = 0.005) and DTI-ALPS index (OR=0.496, 95 % CI: 0.306, 0.806, p = 0.005) were independently associated with cognitive impairment. Mediation analysis revealed that the DTI-ALPS index partially mediated the relationship between the DMV score and cognitive impairment, with an indirect effect of 0.040 (95 % CI: 0.011-0.084, p < 0.001).

Both the DMV score and DTI-ALPS index are independent risk factors for cognitive impairment in patients with CSVD. The DTI-ALPS index significantly and partially mediates the relationship between the DMV score and cognitive impairment.