Deep medullary veins integrity and relationships with small vessel disease and interstitial diffusivity measures in patients with a recent small subcortical infarct

BACKGROUND AND PURPOSE: The role of the venous compartment in cerebral small vessel disease has yet to be fully understood. As such, we evaluated how deep medullary veins integrity relates to MRI-based small vessel disease severity markers and glymphatic function assessed by DTI measures in patients with a recent small subcortical infarct.

MATERIALS AND METHODS: We gathered demographic, clinical, and 3 Tesla-MRI imaging data from 50 patients with a recent small subcortical infarct. We evaluate the venular integrity using two visual scales based on their appearance on SWI. We assessed the number of lacunes and microbleeds, white matter hyperintensities volume, perivascular spaces volume in basal ganglia and white matter, summary-small vessel disease score, and brain volume. Diffusivity measures in normal-appearing white matter included free water fraction, mean diffusivity and fractional anisotropy with and without free water correction, and DTI along the perivascular spaces. After categorizing the cohort in quartiles according to both venular scores, we assessed their correlations with small vessel disease markers and diffusivity measures using multivariable ordinal regression analyses adjusting for age, sex, smoking, and summary small vessel disease score.

RESULTS: In univariate analysis most of the imaging variables, except for microbleeds, perivascular spaces in white matter and DTI-along the perivascular spaces, were associated with one or both venular scores. In multivariate analysis (OR, 95% CI), free water (1.33, 1.03-1.73), mean diffusivity (4.56, 1.32-15.81), fractional anisotropy (0.77, 0.63-0.93), free water-corrected mean diffusivity and fractional anisotropy (2.39, 1.06-5.39;0.78, 0.65-0.94, respectively), associated with vein appearance, while only brain volume (0.48, 0.25-0.94), fractional anisotropy with and without free water correction (0.82,0.86-0.99; 0.83, 0.7-0.99, respectively) remained significant for vein count.

CONCLUSIONS: In patients with a recent small subcortical infarct, disruption of the deep medullary veins, increased extracellular water, and white matter injury appear to be associated.

ABBREVIATIONS: SVD=small vessel disease; DMV=deep medullary veins; WMH=white matter hyperintensities; PVS=perivascular spaces; DTI-ALPS=diffusion tensor image analysis along the perivascular spaces; FW=free water; MD=mean diffusivity; FA= fractional anisotropy; BG=basal ganglia.