Enlarged perivascular spaces in the basal ganglia region are associated with white matter interstitial fluid content via deep medullary vein dysfunction

Haiyuan Lan^1*Xinjun Lei¹Qingchun Wang¹Lebing Wang¹Kunwang Li^2*

• ¹lishui, Lishui, China
• ²Lishui City People's Hospital, Lishui, China

Objective: To investigate the effect of enlarged perivascular spaces in the basal ganglia (BG-EPVS) on interstitial fluid (ISF) content in white matter and to assess the mediating role of deep medullary vein (DMV) dysfunction in this relationship among patients with cerebral small vessel disease (CSVD) . Methods: Magnetic resonance imaging and clinical data were collected from 166 patients with cerebral small vessel disease. EPVS score (0–4) was evaluated on T2-weighted images on the basis of the number of EPVS in a single slice. DMV score (0–18) was assigned on susceptibility-weighted imaging according to signal continuity and clarity. Free water (FW) values, representing ISF content in white matter, were derived from diffusion tensor imaging. Results: The mean age of the participants was 63.6 ± 11.1 years. The median score was as follows: BG-EPVS, 1 (IQR: 1-2); centrum semiovale EPVS (CSO-EPVS), 1 (IQR: 1-2); CSVD score,1 (IQR: 0-2), and DMV, 4 (IQR: 1-11). The mean FW values were 0.25±0.02. No significant correlation was observed between CSO-EPVS and FW (r = 0.112, p = 0.119). In contrast, BG-EPVS showed a moderate positive correlation with both DMV score (r =0.594, p< 0.001) and FW (r=0.521, p<0.001). DMV score was also moderate positively correlated with FW (r =0.557, p< 0.001). These associations remained significant after adjusting for age, sex, and vascular risk factors (all p < 0.05). Mediation analysis confirmed that DMV score significantly mediated the relationship between BG-EPVS and FW, independent of covariates. Conclusion: Higher BG-EPVS score is significantly associated with increased ISF content in white matter, with DMV dysfunction serving as a key mediator of this association.