Respiratory muscle involvement in multiple sclerosis

Respiratory complications are common in the terminal stages of multiple scl erosis and contribute to mortality in these patients. When respiratory moto r pathways are involved, respiratory muscle weakness frequently occurs. Alt hough it is well established that weakness of the respiratory muscles produ ces a restrictive ventilatory defect, the degree of muscle weakness and pul monary function are poorly related. Respiratory muscle weakness was observe d in patients with normal or near normal pulmonary function. Expiratory mus cle weakness is more prominent than inspiratory muscle weakness and may imp air performance of coughing. Subsequently, in addition to bulbar dysfunctio n, respiratory muscle weakness may contribute to ineffective coughing, pneu monia, and sometimes even acute ventilatory failure may ensue, Respiratory muscle weakness may also occur early in the course of the disease Recent st udies suggest that the respiratory muscles can be trained for both strength and endurance in multiple sclerosis patients, Whether respiratory muscle t raining delays the development of respiratory dysfunction and subsequently improves exercise capacity and cough efficacy, prevents pulmonary complicat ions or prolongs survival in the long-term remains to be determined.