2 years' experience with inspiratory muscle training in patients with neuromuscular disorders

Purpose: The aim of our study was to assess the long-term effects of specif ic inspiratory muscle training (IMT) in patients with neuromuscular disorde rs (NMDs) who have various degrees of respiratory impairment. Patients and methods: Twenty-seven patients with NMDs (Duchenne's muscular dystrophy, 18 patients; spinal muscular atrophy, 9 patients) underwent 24 m onths of IMT. Patients were divided into three groups according to their vi tal capacity (VC) values. VC was measured as the parameter for the respirat ory system involvement of the disease. Maximal inspiratory pressure (Pimax) was assessed as the parameter for respiratory muscle strength, and the res ults of the 12-s maximum voluntary ventilation test (12sMVV) were assessed as the parameter for respiratory muscle endurance. Pulmonary and inspirator y muscle function parameters were assessed 6 months before training, at the beginning of training, and then every 3 months. Results: The Pimax values improved in group A (VC, 27 to 50% predicted) fro m 51.45 to 87.00 cm H2O, in group B (VC, 51 to 70% predicted) from 59.38 to 94.4 em H2O, and in group C (VC, 71 to 96% predicted) from 71.25 to 99.00 cm H2O. The 12sMVV values improved in group A from 52.69 to 69.50 L/min, in group B from 53.18 to 62.40 L/min, and in group C from 59.48 to 70.5 L/min . For all three groups, there was a significant improvement of Pimax (p < 0 .007) and 12sMVV (p < 0.015) until the 10th month when a plateau phase was reached with no decline in the following month until the end of training. Conclusion: With IMT, respiratory muscle function can be improved in the lo ng term of up to 2 years.