#ALS #Neurodegeneration
#RespiratoryRehabilitation #RMT
Amyotrophic lateral sclerosis (ALS) is a
severe, progressive, and incurable neurodegenerative disease, characterized by
the
degeneration of cortical, bulbar, and spinal motor neurons. It leads to
generalized muscle weakness, loss of autonomy, and eventually terminal
respiratory failure, which is the main cause of death. The average life
expectancy is 3 to 5 years after symptom onset.
The weakness of respiratory muscles, particularly the diaphragm, gradually
impairs ventilation, reduces coughing ability, and promotes the accumulation of
bronchial secretions, with recurrent respiratory infections. However, the
available treatments only partially address these mechanisms. Respiratory
rehabilitation, especially respiratory muscle training (RMT), could improve
quality of life, functional capacity, or even patient survival. Nevertheless,
available data remain fragmented.
This study was initiated to systematically evaluate the impact of RMT on
respiratory function, ventilatory muscle strength, survival, and quality of
life in patients with ALS.
What if survival depended on breathing?
In this study, five randomized clinical trials including 170 ALS patients,
predominantly with spinal forms and a mean age between 53 and 63 years, were
selected. The interventions included inspiratory, expiratory, or combined RMT
programs, applied via calibrated resistance devices (30 to 60% of maximal
inspiratory/expiratory pressure).
The results show a significant improvement in respiratory muscle strength, with
notable increases in maximal inspiratory pressure (MIP) and expiratory pressure
(MEP) in trained patients. However, forced vital capacity (FVC), a key
indicator of pulmonary function, did not significantly improve, suggesting that
increased strength does not necessarily translate into better pulmonary
volumes. Positive effects were also observed on maximal voluntary ventilation,
cough strength (via peak inspiratory/expiratory flow), and swallowing
(particularly via the DIGEST score). A prolongation of survival related to
inspiratory training was also observed (37 months vs 24 months). No serious
adverse events were reported in the studies.
Read next: Clinical stratification of patients with ALS
Breathing better to live longer?
ALS remains a devastating disease, marked by progressive loss of ventilatory
capacity. The main challenge is to identify non-pharmacological interventions
capable of slowing this decline. This review aimed to determine whether RMT
could play that role.
The results confirm that RMT increases respiratory muscle strength, notably
MEP, which may improve cough and bronchial drainage. These gains could help
delay terminal respiratory failure and reduce infectious complications. Moreover, the positive impact on swallowing suggests a broader role in
maintaining vital functions.
However, the
effects of RMT on pulmonary capacity, quality of life, and fatigue
remain uncertain. The scope of the results is limited by the small sample
sizes, heterogeneity of training protocols, and lack of standardized long-term
follow-up. To consolidate these promising early findings,
further research is
essential. This should rely on
larger-scale clinical trials, including patient
stratification and a
more comprehensive assessment of long-term effects. The
inclusion of additional criteria, such as dyspnea, sleep quality, or overall
motor function, would allow for a more
refined analysis of the benefits and
better
understanding of the overall impact of RMT in the multidimensional
management of ALS.
Read next: Multicellular pathophysiology of neurodegeneration
