Researchers recently identified ongoing atrophy of the caudate nucleus over a 5-year period in a cohort of mildly disabled treated patients with relapsing-remitting multiple sclerosis (RRMS), despite the lack of any significant whole brain atrophy, compared to healthy controls. Furthermore, the detectability of caudate atrophy was dependent on the MRI segmentation pipeline employed. Consistent 3D T1-weighted sequences were performed on a 3T GE unit in 16 mildly disabled patients with RRMS and 16 age-matched normal controls (NC) at baseline and 5 years. All patients received disease-modifying immunotherapy. Images were applied to 2 pipelines to assess whole brain atrophy and 2 other pipelines to assess deep gray matter (DGM) atrophy. Expanded Disability Status Scale (EDSS) and timed 25-foot walk (T25FW) change was compared. They found:

• Using the FreeSurfer pipeline, the MS group had a ~10-fold acceleration in on-study volume loss than NC in the caudate.
• In contrast, caudate atrophy was not detected by the FSL-FIRST pipeline.
• None of the other pipelines showed any difference in volume loss between groups, for whole brain or regional DGM atrophy.
• The MS group showed on-study stability on EDSS but slight worsening of T25FW.