Advancing rehabilitation of multiple sclerosis
Multiple sclerosis (MS) is a chronic autoimmune disorder associated with progressive neurological impairment. The immune system destroys the myelin sheath around neurons, causing reduced transmission of neuronal signals and degeneration. In turn, this leads to deficits of motor, sensory and cognitive functions.
Body-machine interface for multiple sclerosis
Rehabilitation plays a vital role in maintaining and maximising motor functions for individuals with MS. Technology-assisted neurorehabilitation approaches have proven effective in overcoming limitations of traditional treatments. Undertaken with the support of the Marie Skłodowska-Curie Actions (MSCA) programme, the REMAp project developed a body-machine interface (BoMI) to harness the residual motor capabilities of individuals with MS and convert them into commands to external devices. This facilitates mobility in impaired individuals analogous to the natural limbs. “Even in progressive neurologic diseases like MS, motor capabilities are not completely lost, and BoMIs empower users to interact with the environment and control external devices with great efficiency,” explains MSCA fellow Camilla Pierella. REMAp research initially involved the rehabilitative training of persons with MS using the BoMI. Results showed that it was an effective tool to exercise upper limb coordination. The training was well tolerated by people with MS, who also improved in the clinical rating scales.
Proprioception in multiple sclerosis
The body has an inherent ability to sense and perceive its own position, movement, and orientation in space without relying on visual cues. This is known as proprioception and relies on sensory receptors located in muscles, tendons, joints and the inner ear, which send signals to the brain. This sense is crucial for maintaining balance, coordinating movements and executing precise motor tasks. In MS, the interactions of sensory and motor systems have been largely overlooked. “For rehabilitation purposes, it is equally important to quantify both motor and position sense deficits and to understand the underlying mechanisms of how cortical areas process proprioceptive feedback,” emphasises Pierella. Researchers used an immersive virtual reality environment for estimating the proprioceptive deficit in MS patients. Following BoMI training, this deficit decreased, suggesting that the complex nature of the body signals used by the BoMI and the way they were combined to carry out the rehabilitative task made users more aware of their body movements.
Brain reorganisation following BoMI training
With respect to the reorganisation of the central and peripheral nervous system following BoMI-based rehabilitative intervention, individuals were subjected to a specific brain imaging protocol. Correlations were found between motor improvements and increased connectivity of neural circuits implicated in sensory integration, motor modulation and execution were improved. The identification and characterisation of biomarkers of motor impairment at different levels of the nervous system will significantly contribute to MS monitoring in the future. Overall, REMAp successfully advanced state-of-the-art rehabilitation for MS through a personalised BoMI designed to optimise the restoration of functional movements in afflicted individuals. The BoMI promotes the reorganisation of body abilities and enhances multi-joint coordination with concomitant changes in the brain’s motor pathways. Importantly, it employs affordable technology and will therefore be accessible to many individuals with MS.
Keywords
REMAp, BoMI, multiple sclerosis, rehabilitation, body-machine interface, proprioception, motor capabilities, upper limb coordination
