Gray Matter Changes in Demyelinating Disease: Correlations with Clinical Scores

Recent MR studies have shown that, in multiple sclerosis, selective regional, but not global gray matter atrophy occurs in multiple sclerosis. Our aim was to identify specific areas of gray matter volume changes and explore the relationship between atrophy and clinical motor outcomes.

Nine patients with relapsing remitting MS and 9 matched healthy controls were recruited. The Multiple Sclerosis Functional Composite was administered. For MR acquisitions, a GE- Genesis- Signa, 1.5T MR system, was used. A voxel-based morphometry (VBM), subcortical structures segmentation (FIRST) and volumetric (SIENAx) FSL tools were used in the study.

Group comparison showed atrophy for several gray matter regions. The most important volume reductions were found for subcortical deep gray matter areas. Correlations with clinical scores were checked and specific gray matter areas showed significant volume reductions associated with motor scores (9-hole peg time and 25-feet walk time) and EDSS (Expanded Disability Status Scale).

We performed a voxelwise analysis of gray matter changes in MS and found a more prominent atrophy for the subcortical structures than for cortical gray matter. Using an additional analysis (FIRST and SIENAx segmentation/volumetry) we were able to confirm the VBM results and to quantify the degree of atrophy in specific structures. Specific gray matter regions which volume reductions correlate with 25-feet walk, 9-hole peg times and EDSS suggest that 25-feet walk time is the best predictor of disease progression in terms of gray matter reduction.