The R of ALSFRS-R: does it really mirror functional respiratory involvement in amyotrophic lateral sclerosis?

Clinical assessment of the respiratory function is critical in amyotrophic lateral sclerosis (ALS). A standardized process is to monitor the respiratory subscore of the revised ALSFRS (RofALSFRS-R). We tested the utility of RofALSFRS-R and its individual questions in evaluating respiratory functionality. Three hundred and fifty-seven consecutive ALS patients were assessed at entry (T0), three and six months later (T1 and T2). ALSFRS and its subscores decayed significantly (p < 0.001) over time. Improvement in the first respiratory question (dyspnoea, QR1) was found in about 10% of the patients in each period. Between T0 and T1 a significant negative correlation was found between decrease in gait score and QR1 (p = 0.021, r = -0.395) in the subgroup of ALS patients who showed QR1 improvement (n = 34). An improvement in the other respiratory questions was noticed in about 6% of the patients, related to non-invasive ventilation. Possibly, decreased mobility and metabolic demand can cause fewer respiratory symptoms in a subset of patients. The respiratory questions included in ALSFRS-R should be re-addressed by the ALS community.