Respiratory alterations in patients with amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a progressive and heterogeneous neurodegenerative disease that manifests itself in different phenotypes depending on the anatomical region affected.

Retrospective observational study of patients diagnosed with ALS in our healthcare area, classified by phenotypes to assess their relationship with functional respiratory variables, gas exchange, and sleep-related breathing disorders. The search period was from 2014 to 2024.

Data from 201 patients were analyzed. The overall mean incidence of ALS was 3.8 cases (95%CI: 3.3-4.3)/100,000 inhabitants/year, while the prevalence was 9.4 cases (95%CI: 7.8-11.1)/100,000 inhabitants. The results indicated that the spinal phenotype is the most common (49.3%), while the bulbar phenotype presented greater respiratory involvement, with a lower forced vital capacity (FVC) (86% [IQR: 66.5-98]) and greater nocturnal desaturation CT90 8% (IQR: 2.3-32.5%). Likewise, a prevalence of respiratory disorders during sleep was observed, with approximately 50% mild obstructive sleep apnea (OSA), 30% moderate, and 15% severe. Severe OSA was recorded in 8% of patients with spinal ALS, 14% of patients with bulbar ALS, and 17% with other forms of ALS.

The disease significantly affects respiratory function, especially in the bulbar phenotype, and respiratory disturbances during sleep are common. The heterogeneity of ALS highlights the importance of a personalized approach to patient management.