Disability improvement is associated with less brain atrophy development in multiple sclerosis

BACKGROUND AND PURPOSE: It is unknown whether deceleration of brain atrophy is associated with disability improvement in patients with MS. Our aim was to investigate whether patients with MS with disability improvement develop less brain atrophy compared with those who progress in disability or remain stable. MATERIALS AND METHODS: We followed 980 patients with MS for a mean of 4.8 6 2.4 years. Subjects were divided into 3 groups: progress in disability (n ¼ 241, 24.6%), disability improvement (n ¼ 101, 10.3%), and stable (n ¼ 638, 65.1%) at follow-up. Disability improvement and progress in disability were defined on the basis of the Expanded Disability Status Scale score change using standardized guidelines. Stable was defined as nonoccurrence of progress in disability or disability improvement. Normalized whole-brain volume was calculated using SIENAX on 3D T1WI, whereas the lateral ventricle was measured using NeuroSTREAM on 2D-T2-FLAIR images. The percentage brain volume change and percentage lateral ventricle volume change were calculated using SIENA and NeuroSTREAM, respectively. Differences among groups were investigated using ANCOVA, adjusted for age at first MR imaging, race, T2 lesion volume, and corresponding baseline structural volume and the Expanded Disability Status Scale. RESULTS: At first MR imaging, there were no differences among progress in disability, disability improvement, and the stable groups in whole-brain volume (P ¼.71) or lateral ventricle volume (P ¼.74). During follow-up, patients with disability improvement had the lowest annualized percentage lateral ventricle volume change (1.6% 6 2.7%) followed by patients who were stable (2.1% 6 3.7%) and had progress in disability (4.1% 6 5.5%), respectively (P,.001). The annualized percentage brain volume change values were -0.7% 6 0.7% for disability improvement, -0.8% 6 0.7% for stable, and -1.1% 6 1.1% for progress in disability (P ¼.001). CONCLUSIONS: Patients with MS who improve in their clinical disability develop less brain atrophy across time compared with those who progress.