Neural Underpinnings and Sensory Feedback Augmentation During Split-belt Treadmill Training in People with Multiple Sclerosis - Project Summary Multiple Sclerosis (MS) is the most common neurodegenerative disease affecting young adults, with the average onset at 31 years of age. This is pertinent because the over 2 million people with MS (PwMS) are likely to experience the effects of the disease for approximately half their lifespan. Walking difficulties are a common challenge faced by PwMS, leading to an increased risk of falls, musculoskeletal injury, and a reduced quality of life. More specifically, most PwMS experience significant gait asymmetries between their legs. Split-belt treadmill training, where the speed of each leg is controlled independently, improves gait symmetry in PwMS, Parkinson’s disease, and stroke. Additionally, sensory feedback augmentation produces improved gait performance and motor coordination within these populations. However, there is limited research investigating the neural mechanisms underlying these gait adaptations and whether sensory augmentation can elicit enhanced adaptation during split-belt treadmill training. The objective of this project is to identify the neural underpinnings of split-belt treadmill training and test the efficacy of transcutaneous electrical nerve stimulation (TENS) to further improve gait adaptability. It is hypothesized that participants will have heightened activity in the cortical sensorimotor integration regions during split-belt treadmill training, compared to when the belts are moving the same speed. Additionally, it is hypothesized TENS will enhance gait adaptability during split-belt treadmill training. In this F31 proposal, the candidate, Andrew Hagen will recruit 30 PwMS and 30 neurotypical controls. Participants will undergo split-belt treadmill training while cortical activation is measured using functional near- infrared spectroscopy (fNIRS). Separate split-belt treadmill training sessions will also utilize the application of TENS, and the effects on gait adaptability will be assessed using kinetics and kinematics. By enhancing our understanding of the underlying neural mechanisms and evaluating sensory augmentation to enhance split-belt treadmill training, this project aims provide a significant step toward creating a targeted rehabilitation paradigm to improve gait symmetry long term that would improve mobility, independence, and quality of life for not only PwMS but the tens of millions of people who experience gait dysfunction. Mr. Hagen’s long-term goal is to become an academic, translational scientist investigating neural injury rehabilitation. Mr. Hagen will train in a state-of-the-art environment with an exceptional mentoring team at Colorado State University. The sponsor, Dr. Brett Fling, has an extensive background studying sensorimotor control and adaptation in PwMS. Consulting mentors Drs. Jaclyn Stephens and Mark Manago will provide expertise on functional neuroimaging and translational research to prepare Mr. Hagen for a career as a translational scientist. Mr. Hagen’s career development plan consists of 1) training in neuromechanics and neuroimaging, 2) strengthening his background in neural injury rehabilitation methods and clinical application, and 3) further developing his professional and communication skills through interaction with his mentors, coursework, clinical exposure, and conferences.
