Validation of a new functional dyspnea score in amyotrophic lateral sclerosis: ALS functional dyspnea score

Objective: To examine whether the responses to standard dyspnea questionnaires and a new functional dyspnea scale modified for use in ALS correlate with measures of pulmonary function and can be administered by phone Background: Noninvasive ventilation (NIV) is initiated in ALS when Forced Vital Capacity (FVC) falls below 50% or the patient is dyspneic. While several respiratory scales measure symptoms of dyspnea in patients with pulmonary diseases, it is unclear if these scales are applicable to ALS patients and correlate with FVC Design/Methods: 153 ALS subjects in a pilot study of Nutrition (80) and NIV 73) in ALS completed three dyspnea scales: the Medical Research Council Dyspnea Scale (MDS,0 to 5), the Borg Dyspnea score (0 to 10) and the ALSFDS score(sum of 12 questions, each 1-10) at baseline and follow-up (16,32, and 48 weeks). All participants had sitting FVC(sFVC), and NIV subjects had supine FVC (lFVC) and nasal inspiratory pressure(SNIP). Relationship between measurements was evaluated using Pearson/Spearman Correlation Coefficients. NIV subjects had telephone administration of scales before week 16 and 48 visits. Results: 153 subjects completed baseline visits. Fewer than 1% had a total score of zero on the ALSFDS scale, while 76.9% and 34.0% scored zero (indicating no symptoms) on the Borg and MDC scales respectively whereas the ALSFDS was more sensitive. The ALSFDS was significantly correlated with laying and sitting FVC and SNIP at baseline, 32 and 48 weeks and with the ALSFRS-R. ALSFDS phone scores correlated with office scores at 16(ρ=0.73; p\u3c0.001) and 48(ρ=0.67; p\u3c0.001) weeks Conclusions: The ALSFDS scale is a more sensitive measure of dyspnea in ALS than MDS or Borg scales; correlates with the ALSFRS-R and pulmonary impairment, and is validated for telephone administration. This scale may be important for determining who is at risk for pulmonary compromise and in assessing efficacy of respiratory interventions in ALS trials