Non-Invasive Mechanical Ventilation reduces the Motor Decline in Amyotrophic Lateral Sclerosis

BackgroundNon-invasive mechanical ventilation (NIMV) improves Amyotrophic Lateral Sclerosis (ALS) quality of life and survival. However, data about its effect on disease progression are still lacking. ObjectiveTo test whether NIMV use changed the rate of functional decline among ALS patients. MethodsIn this retrospective observational study, we included 465 ALS patients followed up at the ALS Center in Turin, Italy, who underwent NIMV during the disease course. The primary outcome was the change in functional decline after NIMV initiation when adjusting for covariates. Functional decline was based on the non-respiratory items of the ALS Functional Rating Score - Revised (ALSFRS-R). ResultsA slower progression of functional decline followed NIMV initiation (mean improvement 0.13, 95%CI 0.11 to 0.16, p<0.001) regardless of sex, age at diagnosis, and disease duration prior to NIMV initiation. Indeed, the disease stage at NIMV initiation (early or advanced) did not influence the results. Respiratory support exerts its slowing effect mainly on the progression of spinal motor function. ConclusionsWe proved that NIMV influences the rate of motor progression in ALS. This result was not a consequence of the ALSFRS-R floor effect. The functional decline slowed after starting NIMV independently of the site of disease onset. Our results reinforce the importance of not delaying NIMV initiation in all ALS patients. NIMV-induced slowing of disease progression should also be accounted for when evaluating clinical trial outcomes.