Deep medullary vein abnormalities impact white matter hyperintensity volume through increases in interstitial free water.

Background: Our intent was to explore the mediating role of interstitial free water (FW) linking deep medullary vein (DMV) score to white matter hyperintensity (WMH) volume.

Methods: Our research team conducted a forward-looking analysis of initial clinical and imaging information gathered from 125 patients with cerebral small vessel disease. We identified six anatomic DMV regions on susceptibility weighted imaging (SWI) studies. Each region earned a score of 0-3, determined by the visual conditions of vessels, summing all six to generate a DMV score. We utilized fluid-attenuated inversion recovery (FLAIR) sequences to measure the volume of WMH. Additionally, we employed diffusion tensor imaging (DTI) to assess FW value.

Results: DMV score significantly positively correlated with FW value and with WMH volume (p < 0.05), and value of FW positively correlated with WMH volume (p < 0.05). The indirect effect of DMV score on WMH volume was mediated by FW (β = 0.281, 95% confidence interval [CI]: 0.178-0.388), whether adjusted for age and gender (β = 0.142, 95% CI: 0.058-0.240) or for age, gender and vascular risk factors (β = 0.141, 95% CI: 0.054-0.249).

Conclusion: DMV score correlate with WMH volume by virtue of FW increases in white matter.