Respiratory Strength Training in Amyotrophic Lateral Sclerosis: A Double-Blind, Randomized, Multicenter,...

Area of Science:

• Neurology
• Pulmonology
• Rehabilitation Medicine

Background:

• Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease affecting motor neurons.
• Respiratory muscle weakness is a common and serious complication in ALS, impacting quality of life and survival.
• Respiratory strength training (RST) is a potential intervention to mitigate respiratory decline in ALS.

Purpose of the Study:

• To evaluate the short-term physiological effects of a 12-week RST program in individuals with ALS.
• To assess the one-year functional outcomes of RST in early-stage ALS patients.
• To determine the safety and tolerability of RST in this population.

Main Methods:

• A double-blinded, randomized, sham-controlled trial involving 45 early-stage ALS participants.
• Participants were assigned to 12 weeks of active RST (30% load) or sham RST (0% load).
• Primary outcomes included maximum expiratory and inspiratory pressures (MEP, MIP); secondary outcomes included cough spirometry and FVC. One-year outcomes assessed global and bulbar decline (ALSFRS-R), oral intake, and time to NIV.

Main Results:

• The RST program was well-tolerated with a 91% completion rate and no adverse events.
• Active RST significantly increased MEP (p=0.004) but not MIP (p=0.33). Cough peak inspiratory flow also increased (p=0.02).
• A significant difference in ALSFRS-R bulbar subscale slope was observed, with a more than two-fold slower rate of decline in the active RST group compared to sham (p=0.02).

Conclusions:

• A 12-week mild-intensity RST program is safe and improves expiratory muscle strength in early-stage ALS.
• RST demonstrated a positive impact on slowing bulbar decline over one year, suggesting a proactive rehabilitative role.
• Further research is needed to optimize RST intensity and resistance for maximal long-term functional benefits in ALS.