Characterizing the Contribution of White Matter on Ambulation in Relapsing Multiple Sclerosis
Cristina Jageka1, Fen Bao1, Mahmoud Elkhooly1, muhammad raghib1, Emily Pelc1, Adam Lazar1, Zahid Latif1, Carla Santiago-Martinez2, Jacob Rube3, Evanthia Bernitsas4
1Detroit Medical Center, 2Wayne State University, 3University Health Center, 4Wayne State School of Medicine
Objective:
In this study we investigated ambulation and its association with white matter tracts in eighty Relapsing Remitting Multiple Sclerosis (RRMS) patients.
Background:
Ambulation is commonly affected in Multiple Sclerosis (MS) and is a major determinant of disability. Timed 25-foot walk (T25FW) is an objective measure of maximum walking speed in a short distance. To date, consistent neuroimaging correlates of ambulation in MS are not well explored.
Design/Methods:
Eighty participants with RRMS were recruited and underwent a 3 Tesla whole brain MRI scan, Expanded Disability Status Scale (EDSS), and T25FW. We performed region-based tractography and we correlated Mean Fractional Anisotropy (FA) and Mean Diffusivity (MD) to the patients’ T25FW, using the Spearman’s rank correlation coefficient (r).
Results:
Our participants’ mean age was 42±10.5 years, median EDSS was 1.4 (1-4), and disease duration was 8.4±8 years. The strongest correlations between FA and T25FW were observed on the left arcuate fasciculus (r=-0.5, p= 0.001), right and left acoustic radiation (r=- 0.41, p=0.001; r=-0.38, p=0.001 respectively), right and left corticothalamic pathway (r=- 0.41, p=0.001; r=-0.37, p=0.001 respectively), right optic radiation (r=-0.41, p=0.001) and medial lemniscus (r=-0.35, p=0.001). The strongest correlations between MD and T25FW were found on the right and left arcuate fasciculus (r=0.40, p= 0.001 and r=0.45, p= 0.001 respectively), right and left corticothalamic pathway (r=0.37, p=0.001; r=0.35, p=0.001 respectively), right dorsal longitudinal fasciculus (r=0.36, p=0.001; r=0.35), and superior cerebellar peduncle (r=0.40, p=0.001).
Conclusions:
Our findings enrich our understanding of ambulation in MS and confirm that ambulation is a complex process. Longitudinal studies are needed to validate our findings and further determine the role of different white matter tracts in its pathobiology.