Longitudinal enlargement of choroid plexus is associated with inflammation and neurodegeneration in RRMS patients

Abstract

BackgroundThe Choroid Plexus (CP) plays a potential role in the initiation and propagation of neuroinflammatory processes in MS. However, the progressive change of the CP and its associations with biomarkers of acute and chronic inflammation, along with MS-related brain structure atrophy, have not been investigated.ObjectiveThis study aims to explore the longitudinal dynamics of the CP in RRMS patients and assess its relationship with inflammation and with atrophy in various brain compartments.Methods57 RRMS patients were examined annually for a minimum of 60 months using following MRI protocols: pre- and post-contrast (gadolinium) Sagittal 3D T1, FLAIR CUBE, diffusion weighted MRI. CP was manually segmented at baseline and last follow-up and normalised by head size. Annually lesion segmentation was performed by iQ-MSTM software suite and brain was segmented using AssemblyNet.ResultsOver the study period, the volume of CP increased by an average of 1.4% annually. The magnitude of CP enlargement significantly correlated with central brain atrophy, and to a lesser extent, total brain atrophy, white matter, and deep grey matter atrophy. Furthermore, progressive CP enlargement was significantly associated with the volume and severity of chronic lesion expansion (r=0.66, p<0.001), but not with the number or volume of new lesions.ConclusionOur findings indicate that ongoing inflammatory activity in the CP is linked to low-grade demyelination at the rim of chronic lesions and associated neurodegeneration of periventricular white and grey matter.