Voluntary up-regulation of reflex cough is possible in healthy older adults and Parkinson’s disease

Congratulations to Drs. Karen Hegland, Michael Okun and Paul Davenport on the publication of “Voluntary up-regulation of reflex cough is possible in healthy older adults and Parkinson’s disease,” which was published in the March edition of the Journal of Applied Physiology.

Abstract

Background: Cough is an airway protective mechanism that serves to detect and forcefully eject aspirate material. Existing research has identified the ability of healthy young adults to suppress, or modify cough motor output based on external cueing. However, no study has evaluated the ability of people with Parkinson’s disease (PD) and healthy older adults (HOAs) to up-regulate cough motor output. The goal of this study was to evaluate the ability of people with PD and healthy age-matched controls (HOAs) to volitionally up-regulate reflex and voluntary cough function with verbal instruction and visual biofeedback of airflow targets. Methods: Sixteen PD and 28 HOA participants (56-83 years) were recruited for this study. Experimental procedures utilized spirometry to evaluate: 1) baseline reflex cough (evoked with capsaicin) and voluntary sequential cough, and 2) reflex and voluntary cough with up-regulation biofeedback. Cough airflow was recorded and repeated measures ANOVA was used to analyze differences in cough airflow parameters. Results: Cough peak expiratory airflow rate (PEFR) and cough expired volume (CEV) were significantly greater in the cueing condition for both induced reflex (p<.001) and voluntary cough (p<.001) compared to baseline measures. Discussion: This is the first study to demonstrate the ability of people with PD and HOAs to volitionally up-regulate induced reflex and voluntary cough motor output. These results support the development of studies targeting improved cough effectiveness in patients with airway protective deficits.