Effects of A Dual-Task Intervention in Postural Control in Multiple Sclerosis Patients

Multiple sclerosis (MS) is a chronic inflammatory autoimmune disease affecting the central nervous system. It is the leading cause of severe non-traumatic disability in young adults (20-40 years). It affects more than 540,000 individuals in Europe and around 2.8 million people worldwide. The etiology of MS remains unknown to date, but probably results from a genetic predisposition associated with environmental factors (vitamin D deficiency, tobacco, vaccines, stress, diet, ...). MS is a neurological disease in which demyelination and axonal loss lead to many symptoms such as fatigue, spasticity, decreased sensitivity, muscle weakness, balance disorders, oculomotor visuals. The Expanded Disability Status Scale (EDSS), which is used to rate functional disorders in MS patients, tends to underestimate these neurological disorders, which are often present in the early stages of the disease and are an important issue. major in the management and evolution of the disease. Recently, it has been shown that motor and cognitive disorders appear in the early stages of the disease, yet these functions are not systematically evaluated in the early stages of the disease. These isolated or associated disorders often lead to real difficulties in realizing everyday activities. Since this disease affects young people who still have a professional activity, it is important not to underestimate the presence of these functional and cognitive disorders. It is therefore necessary to seek more precise means of evaluation to detect certain neurological disorders. Thus, the evaluation of these functions participates in the follow-up of the patient and makes it possible to better apprehend the evolution of these disorders in MS. The investigators will use the concept of double-task to measure and evaluate these functional and cognitive disorders. The dual task (DT) , is defined by the simultaneous completion of two tasks, one called "primary" and the other called "secondary", for which t