Walking disability measures in multiple sclerosis patients: Correlations with MRI-derived global and microstructural damage

Dejan Jakimovski; Bianca Weinstock-Guttman; Jesper Hagemeier; Caila B Vaughn; Katelyn S Kavak; Sirin Gandhi; Susan E Bennett; Tom A Fuchs; Niels Bergsland; Michael G Dwyer; Ralph H B Benedict; Robert Zivadinov

doi:10.1016/j.jns.2018.08.020

Walking disability measures in multiple sclerosis patients: Correlations with MRI-derived global and microstructural damage

J Neurol Sci. 2018 Oct 15:393:128-134. doi: 10.1016/j.jns.2018.08.020. Epub 2018 Aug 23.

Affiliations

¹ Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA.
² Jacobs MS Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, NY, USA.
³ Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA; Center for Biomedical Imaging at Clinical Translational Science Institute, University at Buffalo, State University of New York, Buffalo, NY, USA. Electronic address: rzivadinov@bnac.net.

PMID: 30165291
DOI: 10.1016/j.jns.2018.08.020

Abstract

Background: The relationship between walking disability in multiple sclerosis (MS) patients and their macro- and microstructural MRI-derived measures still remains unclear.

Objective: To assess the correlations between walking disability and MRI-derived lesion, atrophy, and microstructural/axonal integrity outcomes.

Methods: Seventy-one (71) MS patients were clinically examined, the expanded timed get-up and go (ETGUG), and timed 25-foot walk (T25FW) tests were assessed. Additionally, the Symbol Digit Modalities Test (SDMT) was obtained. Normalized brain (NBV), gray matter (GMV), white matter (WMV), cortex (CV), and deep GM (DGM) volumes, as well as lesion volumes (LV) and diffusion tensor imaging (DTI) scalar maps of fractional anisotropy, mean diffusivity, radial diffusivity, and axial diffusivity were calculated. Spearman correlation, partial correlation and stepwise regression analyses were performed.

Results: T25FW and ETGUG were associated with T2-LV (p < .001), global (NBV, p < .001), tissue-specific (GMV and CV, p < .001) and regional (DGM p < .001; and thalamus p < .001) volumes. The ETGUG remained correlated with T1-LV, GMV, CV and total DGM volume (all p < .001) after age, sex, and disease duration adjustment. The WMV was not associated with walking disability. Similarly, DTI measures did not show significant association with the walking tests. The regression analysis outlined DMG volume as best predictor of T25FW (Adj R² = 0.231, standardized β = -0.435, and p = .001), and CV for ETGUG (Adj R² = 0.176, standardized β = -0.417, and p = .004). SDMT was associated with both T25FW (p = .004) and ETGUG (p = .013).

Conclusion: Despite the low disability levels, walking as measured by T25FW and ETGUG, is largely explained by the loss of cortical and nuclei specific GM volumes.

Keywords: Brain atrophy; Diffusion-tensor imaging; ETGUG; Lesion volume; MRI; Multiple sclerosis; T25FW; Walking disability.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

MeSH terms

Atrophy
Brain / diagnostic imaging*
Cohort Studies
Disability Evaluation
Exercise Test
Female
Gray Matter / diagnostic imaging
Humans
Image Processing, Computer-Assisted
Magnetic Resonance Imaging*
Male
Middle Aged
Multiple Sclerosis / diagnosis*
Multiple Sclerosis / physiopathology
Organ Size
Walking* / physiology