Associations between connectivity in functional brain networks and gait speed in older adults with and without multiple sclerosis.

Abstract

Objective: To assess whether resting-state functional connectivity (RSFC) brain networks are associated with gait speed in a sample of older adults with and without multiple sclerosis (MS).

Methods: Older adults with MS (OAMS: n = 82, mean age = 64.4 ± 4.1 years) and controls (n = 85, mean age = 68.6 ± 7.1 years) underwent brain MRI, cognitive assessment, and motor testing. RSFC brain networks were computed from resting-state functional scans based on a data-driven approach. The timed-25-foot-walk test (T25FW), an established measure of disability in aging and clinical populations, served as the outcome measure.

Results: Analyses adjusted for confounders revealed that faster gait speed was significantly associated with higher RSFC in left fronto-parietal (p = 0.002) network in the full cohort. Among OAMS, significant associations between faster gait speed and higher RSFC were found in left fronto-parietal (p = 0.002), cerebellar (p = 0.023), and language (p = 0.046) networks. In contrast, among control participants, there were no significant associations between RSFC and gait speed.

Conclusion: In aging, greater functional brain support of walking speed, operationalized using RSFC in empirically derived networks, is required in MS compared to healthy control participants.