Relating perivascular imaging measures to longitudinal lesion evolution and chronic inflammation in multiple...

Perivascular space (PVS) alterations may be associated with acute and chronic inflammatory activity in people with multiple sclerosis (pwMS).

Investigate whether diffusion tensor image analysis along the PVS (DTI-ALPS) or PVS number/volume are associated with lesion evolution in pwMS over 5-years.

182 patients (142 relapsing-remitting MS [pwRRMS] and 40 progressive MS [pwPMS]) underwent clinical and MRI examinations at baseline and 5-year follow-up. All pwMS were assessed for contrast enhancing lesions (CELs), T2 lesions, T1 lesions and cortical lesions (CLs). A subset of 86 pwMS were analyzed for presence of paramagnetic rim lesions (PRL). Associations between DTI-ALPS, PVS number/volume and lesion types were evaluated using regression and ANCOVA models, adjusting for age, sex, disease duration and normal-appearing white matter mean diffusivity, with false discovery rate correction for multiple comparisons, resulting in q values.

In pwRRMS, baseline DTI-ALPS was associated with baseline CEL number (q < 0.001), T1 lesion number (q = 0.013), T2 lesion volume (q = 0.037) and T1 lesion volume (q < 0.002). It was associated with accumulation of new/enlarging CL (q = 0.013) and T1 lesions (q = 0.007), absolute change in T1 lesion volume (q = 0.025) and trended with newly appearing PRLs (q = 0.066). Absolute 5-year change in PVS volume was related to PRL presence at baseline (q = 0.018).

PVS alterations are associated with lesion evolution in pwRRMS.