Inspiratory muscle training in patients with amyotrophic lateral sclerosis: a systematic review

Abstract

BACKGROUND: Amyotrophic Lateral Sclerosis is a neurodegenerative disease with rapid involvement of the inspiratory muscles, leading to respiratory insufficiency. Death often occurs by aspiration and pneumonia. Endurance- and strength therapy within ALS are discussed controversially. OBJECTIVE: To review the current literature to assess the efficacy of inspiratory muscle training for ALS. METHOD: Systematic review, using databases as PubMed, PEDro, Cochrane and Google Scholar. INTERVENTION: Inspiratory muscle training vs. sham training or inspiratory muscle training alone. OUTCOME MEASURES: Inspiratory muscle strength, dyspnoea, quality of life and survival time. RESULTS: Four studies could be included in this review, two RCT's, one pre-experimental study and one with a historical control group. In total 73 patients underwent inspiratory muscle training. CONCLUSION: Studies varied in onset of the training, the training protocol and the outcomes measured. At time, there is limited evidence that inspiratory muscle training leads to strengthening of inspiratory muscles in ALS. Improvements made were minor, in only a few parameters and also in control groups. Survival time was significantly longer in the experimental group in one study. Interesting suppositions (diaphragm training vs. other IM training, improvement of chest wall and lung compliance) need to be examined in robustly designed future trials, defining exact therapeutic windows and interventions.