Association of choroid plexus volume with brain atrophy and glucose metabolism in multiple system atrophy

The choroid plexus (CP), a component of the glymphatic system, is essential in homeostasis and producing cerebrospinal fluid. Role of CP in multiple system atrophy (MSA) remains unclear. This study aimed to investigate the implication of the CP in MSA. This retrospective cross-sectional study included 87 MSA patients who underwent the Unified MSA Rating Scale (UMSARS), brain MRI, and¹⁸F-fluorodeoxyglucose PET scan, along with 84 healthy controls (HCs). Multivariate linear regression analyses were performed to examine the associations between CP volume (CPV) and UMSARS scores, as well as the volumes and cerebral metabolism. Compared with HCs, MSA had significantly reduced CPV (1.00 ± 0.27 vs. 1.30 ± 0.26, P < 0.001). CPV showed no association with UMSARS, however, it was positively correlated with regional cerebellar volumes. Reduced CPV was associated with lower cerebral glucose metabolism in MSA-susceptible regions, consistent with the positive association between CPV and regional cerebral glucose metabolism observed in multivariate analyses. Notably, CPV positively correlated with glucose metabolism in the brainstem (β = 0.110, P = 0.003) and cerebellar white matter (β = 0.080, P = 0.004). This study suggests that CPV is positively associated with disease burden in MSA, with CPV decreasing as disease severity increases. Further research is warranted to determine whether CPV could serve as a potential biomarker for MSA.