Expiratory Muscle Conditioning in Multiple Sclerosis Using Magnetic Stimulation

Optimal respiratory function depends on intact neural circuitry which orchestrates the interplay between respiratory muscles and intrinsic pulmonary function to maintain adequate ventilation. In the absence of respiratory muscle activation, pressure gradients cannot be developed and air exchange at the alveolar surface cannot occur. Thus, any impairment in respiratory muscle performance can lead to pulmonary dysfunction, respiratory distress and even death. Multiple sclerosis (MS) is a primary disorder of the central nervous system that often affects motor pathways, causing diminished muscle strength and endurance throughout the body including the ventilatory muscles. Respiratory complications are recognized as the major cause of morbidity and mortality in individuals with advanced MS. The investigators' research team has over 15 years of experience using Functional Magnetic Stimulation (FMS) for stimulating nerves and muscles below the level of injury in patients with chronic SCI; and has also demonstrated significant benefit for improving respiratory muscles, bladder and bowel functions. In this study, the investigators will investigate the efficacy of using FMS technique for respiratory muscle conditioning in patients with multiple sclerosis; and will compare the results of the expired functions (volume, pressure, and flow) generated by using the FMS technique with data obtained from using the resistive expiratory muscle training (REMT) methodology.