Exploring cortical activation patterns during linear vs. curvilinear walking in people with multiple sclerosis using a walking aid

Multiple Sclerosis (MS) is a chronic disease of the central nervous system characterized by inflammation, demyelination, axon loss and gliosis. Mobility impairment is one of the key clinical symptoms of MS, and a decline in walking abilities can significantly affect quality of life in people with MS (PwMS). As the disease progresses, these symptoms typically worsen, requiring the support of walking aid during gait. Here, we aimed to identify the cortical activation patterns associated with walking in PwMS using walking aids, by means of functional Near-Infrared Spectroscopy (fNIRS). Also, since directional changes are integral to real-world mobility, we compared the neural circuitry activated during two types of walking: linear and curvilinear. Nineteen PwMS with an EDSS score equal to 6 were enrolled for the study. Using fNIRS we examined cortical correlates of walking in a linear and curvilinear pathway for 30 seconds while using their personal walking aid. Our results showed a wide activation of cortical areas during walking in this population, including prefrontal, sensorimotor, and parietal regions, both during the linear and curvilinear path. Moreover, higher activation during curvilinear walking with respect to linear was revealed in specific Brodmann Areas (BA): central BA10, BA8, and BA6, and right BA8. These areas are differently active during more challenging requirements, suggesting the necessity of greater control from prefrontal and premotor areas while walking on curved paths. This study suggests the need to incorporate both linear and curvilinear gait training with walking aids in rehabilitation for preparing patients for real-world mobility challenges.