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

ObjectiveTo 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).MethodsOlder 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.ResultsAnalyses 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.ConclusionIn aging, greater functional brain support of walking speed, operationalized using RSFC in empirically derived networks, is required in MS compared to healthy control participants.