Choroid Plexus Enlargement and USPIO-Based Inflammatory Feature in Cerebral Small Vessel Disease

The choroid plexus (CP) is a key component of the blood-cerebrospinal fluid barrier (BCSFB), but its mechanism of action in cerebral small vessel disease (CSVD) remains unclear. This study investigated CP volume (CPV) alterations and their association with conventional imaging markers in CSVD and explored the underlying role of inflammation using ultrasmall superparamagnetic particles of iron oxide (USPIO)-enhanced MRI.

In this study, 111 CSVD patients and 69 healthy controls (HC) underwent 3.0 T conventional MRI to quantify CPV in the lateral (LV), third (3 V), and fourth (4 V) ventricles. CSVD burden was evaluated using visual assessment scales, including indicators such as white matter hyperintensities (WMH), lacunes, basal ganglia-enlarged perivascular spaces (BG-EPVS), cerebral microbleeds (CMBs), and brain atrophy (BA). A subgroup (22 CSVD, 10 HC) underwent USPIO-enhanced MRI to measure the change of signal intensity ratio (∆SIR) as a feature of inflammatory activity in the CP and deep gray matter nuclei.

CSVD patients showed significantly larger CPV (all p < 0.001). CPV demonstrated significant positive correlations with the severity of conventional CSVD imaging markers (all p < 0.05). USPIO-enhanced MRI revealed an increased ΔSIR in the LV, 3 V, and 4 V CP (all p < 0.05). Furthermore, increased USPIO uptake was observed in deep gray matter nuclei in CSVD. Crucially, a positive correlation was found between LV CP volume and ΔSIR (r = 0.375, p = 0.034), and the LV CP inflammation was strongly correlated with the hippocampus (r = 0.582, p < 0.001).

CP enlargement is prominent in CSVD and closely linked to the CSVD imaging burden. CP inflammation is associated with increased volume. CP may be a novel biomarker to help diagnose, monitor, and treat neuroinflammation in CSVD.