Association between choroid plexus enlargement and impaired glymphatic function in relapsing-remitting multiple...

Although the glymphatic system and choroid plexus (CP) have been studied in MS, their longitudinal evolution remains poorly understood. Therefore, we aim to characterize glymphatic system function and CP alterations and their longitudinal evolution in relapsing-remitting multiple sclerosis (RRMS), and to examine the relationship with other clinical variables.

Ninety-two patients with RRMS and forty healthy controls (HCs) were recruited. The diffusion tensor imaging analysis along the perivascular space (DTI-ALPS) index and the normalized volume of the choroid plexus (CPV) were compared between the two groups in baseline and follow up. Furthermore, their correlations with white matter lesion (WML) and cortical lesion volume were investigated in the RRMS group.

RRMS patients exhibited a significantly lower ALPS index (p = 0.001) and a larger CPV (p < 0.001) compared to HCs. A lower ALPS index was associated with larger CPV (p = 0.011), greater WML volume (p < 0.001) and cortical lesion volume (p = 0.004), and longer disease duration (p = 0.022). Furthermore, larger CPV was correlated with greater cortical lesion volume (p = 0.037). In the follow-up group, the CPV slightly increased (p = 0.02), while the ALPS index showed no significant change.

Impaired glymphatic system function and enlarged CP volume may contribute to the pathological mechanisms underlying MS. Moreover, CP enlargement may persist throughout the course of MS. DTI-ALPS index and CP volume are potential imaging biomarkers, and the CP may be a promising therapeutic target in MS.