Assistive Device Training Results in Improved Functional Mobility and Reduced Thalamo-Cortical Connectivity in People with MS

Background: Many people with multiple sclerosis (PwMS) have impaired functional mobility and abnormal connectivity of the locomotor neural network as assessed by resting state functional MRI. PwMS frequently use devices, such as canes and walkers, to assist with their mobility but still have impaired mobility and fall frequently. Assistive devices may not be optimally effective because PwMS do not receive adequate training in their use. 

Objectives: This study’s objectives are to evaluate the impact of assistive device training (selection, fitting and use) on functional mobility and on functional connectivity of the locomotor neural network in PwMS.

Methods: At baseline and following 6 weekly sessions of assistive device training, functional mobility was assessed by the Timed Up and Go (TUG), Timed 25 Foot Walk (T25FW), 2 minute timed walk (2MTW), 4 square step test (FSST) and the Multiple Sclerosis Walking Scale-12.  Functional connectivity of the locomotor network was assessed by resting state functional MRI at the same time points. Mean changes in measures were assessed by paired t-tests and relationships between mobility and MRI measures were assessed by linear regression.  Here we present results from the first 8 PwMS who have completed training.

Results: There were significant improvements in functional mobility and significant changes in functional connectivity of the locomotor network. Participants had significantly improved mean T25FW times (8.5s to 6.9s; p = 0.01) and MSWS-12 scores (44.1 to 40.6; p = 0.03) following training. No significant differences were observed on the TUG (14.4s to 13.5s; p = 0.23), 2MTW (99.5m to 115.3m; p = 0.08), or FSST (27.9s to 31.6s; p = 0.29). Functional connectivity between the supplementary motor areas (SMA) and the thalamus was significantly reduced following training, consistent with increased inhibition. Reduced connectivity between the left hemisphere’s SMA and thalamus was significantly associated with improvements in T25FW (r = 0.75; p = 0.03) and 2MTW (r = -0.71; p = 0.05) following training.

Conclusions: 6 weeks of assistive device training results in improvements in functional mobility that are associated with reductions in functional connectivity of the thalamo-cortical loop. These results suggest that refined inhibitory control of the motor cortices via the thalamus contributes to improved functional mobility in PwMS. Data collection is ongoing to strengthen these exciting initial results.