Subcortical grey matter volumes predict subsequent walking function in early multiple sclerosis.

BACKGROUND

Atrophy of subcortical grey matter structures has been reported to be associated with clinical measures of disability in multiple sclerosis (MS) patients. It is not clear if the degree of tissue loss in patients with very early MS is associated with changes in disability measures.

OBJECTIVE

To study the association between subcortical grey matter structure volumes and clinical disability outcomes.

METHODS

Relapsing MS patients within 12months of clinical onset were enrolled in a neuroprotection trial of riluzole versus placebo with up to 36months of follow-up and serial brain MRI and clinical assessments. MRI metrics, including thalamic, putamen, caudate, pallidum and cerebellar cortical volume, were measured by an automated, custom-made FreeSurfer pipeline. Volumes were normalized for head size. Clinical measures included EDSS, MSFC scores and its components. Mixed model regression measured time trends and associations between imaging and clinical outcomes.

RESULTS

42 patients with a mean follow-up of 30.6months were analyzed in this study. There was a statistically significant decrease in thalamus, caudate and putamen volumes, but not cerebellar cortical and pallidum volumes during the follow-up period. Baseline thalamus, caudate and putamen volumes predicted subsequent changes in the timed 25-ft walk test (p=0.036) and MSFC (p=0.024). There was a trend for an association between baseline caudate volume and subsequent change in the timed 25-ft walk test (p=0.084). No association between baseline imaging and subsequent EDSS changes were seen.

CONCLUSION

Subcortical grey matter volumes at early stages of MS are associated with subsequent changes in disability measures.