Microglial activation, white matter tract damage, and disability in MS

Radioligand binding by group among healthy controls (HC, n = 17), patients with RRMS (n = 10), and patients with SPMS (n = 10) in non–lesion-associated ROIs (A), gadolinium-negative lesion-associated ROIs (B), and gadolinium-positive lesion-associated ROIs (C). Each boxplot represents the group median, 1st and 3rd quartiles, minimum and maximum, and outliers (black dots) of distribution volume ratio (DVR) values in each ROI. NAWM = normal-appearing white matter; T1 Gd− = T1-hypointense, gadolinium-negative lesion ROI (including all T1 Gd− lesions); Gd− 0–3 mm rim = perilesional circular ROI 0–3 mm from the edge of gadolinium-negative lesions; Gd− 3–6 mm rim = perilesional circular ROI 3–6 mm from the edge of gadolinium-negative lesions; T1 Gd+ = T1-hypointense, gadolinium-positive lesion ROI (including all T1 Gd+ lesions); Gd+ 0–3 mm rim = perilesional circular ROI 0–3 mm from the edge of gadolinium-positive lesions; Gd+ 3–6 mm rim = perilesional circular ROI 3–6 mm from the edge of gadolinium-positive lesions. *Analysis of , age as a covariate, p < 0.05. #Repeated-measures analysis of variance (ANOVA), p < 0.05. ##Repeated-measures ANOVA, p < 0.001.

Region of interest–specific binding of [¹¹C](R)-PK11195 measured as the distribution volume ratio (DVR) in the normal-appearing white matter (NAWM) plotted with (A) Expanded Disability Status Scale (EDSS), (B) MS severity score (MSSS), (C) mean fractional anisotropy (FA) in the NAWM, and (D) the DVR in the thalami plotted with mean FA in the NAWM in the pooled MS patient group. The correlations are visualized with linear regression lines corresponding to the results from repeated-measures analysis of covariance (rm ANCOVA) reported in tables e-1 and e-3 (links.lww.com/NXI/A37). SPMS = secondary progressive MS; RRMS = relapsing-remitting MS.