Respiratory exercise in amyotrophic lateral sclerosis

Abstract

We have evaluated the potential role of respiratory exercise by implementing specific inspiratory muscle training in a selected population of early-affected amyotrophic lateral sclerosis (ALS) patients. We studied 26 patients with ALS with normal respiratory function using two groups of patients in a parallel, control-group, randomized, delayed-start design. Patients in the first group (G1) started the active inspiratory exercise programme at entry and were followed for eight months, while the second group (G2) of patients followed a placebo exercise programme for the first four months and then active exercise for the second four-month period. The primary outcome measure was the ALSFRS. Respiratory tests, neurophysiological measurements, fatigue and quality of life scales were secondary outcomes. Analysis of covariance was used to compare changes between and within groups. Results showed that there was no significant difference between the two patient groups. Within-group analysis suggested that inspiratory exercise promotes a transient improvement in the respiratory subscore and in the maximal voluntary ventilation, peak expiratory flow, and sniff inspiratory pressure. In conclusion, there was no clear positive or negative outcome of the respiratory exercise protocol we have proposed, but we cannot rule out a minor positive effect. Exercise regimes merit more detailed clinical evaluation in ALS.

Key words::

• Inspiratory muscle training
• delayed-start design
• amyotrophic lateral sclerosis

Acknowledgements

The first author has a grant from the ‘Fundação para a Ciência e a Tecnologia’. The authors are grateful to Respironics® for providing the devices for respiratory training. We are grateful to Licínio Carneiro for introducing us to the device, to Joaquim Ferreira for helpful suggestions in trial design, to Ana Noronha for randomization, to Manuel Scotto for statistical advice and to Margarida Fernandes for administrative help.

This work was supported by ‘Fundação para a Ciência e Tecnologia’ (project PIC/IC/82765/2007).

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.