Thalamic atrophy occurs early in MS and the rate of atrophy remains consistent throughout the disease course.51 However, thalamic pathology in MS is not limited to atrophy, but extends to heterogeneous microstructural alterations that relate to cognitive disability progression.52,53 Moreover, thalamic TSPO activity predicts disability progression in MS.19 In the current study, sGFAP was associated with both thalamic TSPO activity and volume. Here, TSPO is linked to Atrophy.