Differences in voluntary and reflexive cough strength in individuals with amyotrophic lateral sclerosis and healthy adults.

Abstract

Dystussia impacts the ability to protect the airway. Voluntary cough provides a metric of airway defense but differs from the reflexive response to aspiration during swallowing. Therefore, we evaluated relationships between voluntary and reflexive cough among individuals with amyotrophic lateral sclerosis (ALS) and a healthy cohort. Twenty-eight individuals with ALS and 26 healthy individuals completed voluntary and reflexive cough testing. Descriptive statistics, reliability, and paired t tests were conducted to evaluate differences in cough volume acceleration (CVA) and peak expiratory flow rate (PEFR) in voluntary vs reflexive cough. Compared with reflexive cough, voluntary CVA and PEFR were greater in individuals with ALS [t(27) = 4.83, P < .001 and t(27) = 8.69, P < .001] and the healthy cohort [t(21) = 5.91, P < .001 and t(21) = 12.26, P < .001], respectively. These findings hold important implications for the use and interpretation of voluntary peak cough flow during clinical swallowing evaluations.