title: Comparison of voluntary and reflex cough effectiveness in Parkinson's disease.
abstract: BACKGROUND
  Multiple airway protective mechanisms are impacted with Parkinson's disease (PD), including swallowing and cough. Cough serves to eject material from the lower airways, and can be produced voluntarily (on command) and reflexively in response to aspirate material or other airway irritants. Voluntary cough effectiveness is reduced in PD however it is not known whether reflex cough is affected as well. The goal of this study was to compare the effectiveness between voluntary and reflex cough in patients with idiopathic PD.
  
  
  METHODS
  Twenty patients with idiopathic PD participated. Cough airflow data were recorded via facemask in line with a pneumotachograph. A side delivery port connected the nebulizer for delivery of capsaicin, which was used to induce cough. Three voluntary coughs and three reflex coughs were analyzed from each participant. A two-way repeated measures analysis of variance was used to compare voluntary versus reflex cough airflow parameters.
  
  
  RESULTS
  Significant differences were found for peak expiratory flow rate (PEFR) and cough expired volume (CEV) between voluntary and reflex cough. Specifically, both PEFR and CEV were reduced for reflex as compared to voluntary cough.
  
  
  CONCLUSIONS
  Cough PEFR and CEV are indicative of cough effectiveness in terms of the ability to remove material from the lower airways. Differences between these two cough types likely reflect differences in the coordination of the respiratory and laryngeal subsystems. Clinicians should be aware that evaluation of cough function using voluntary cough tasks overestimates the PEFR and CEV that would be achieved during reflex cough in patients with PD.
authors.affiliation: Department of Speech Language and Hearing Sciences, College of Public Health and Health Professions, University of Florida, Gainesville, FL, USA; Center for Movement Disorders and Neurorestoration, College of Medicine, University of Florida, Gainesville, FL, USA. Electronic address: kwheeler@ufl.edu.
authors.forename: Karen
authors.initials: K
authors.lastname: Wheeler Hegland
authors.affiliation: Department of Speech Language and Hearing Sciences, College of Public Health and Health Professions, University of Florida, Gainesville, FL, USA; Center for Movement Disorders and Neurorestoration, College of Medicine, University of Florida, Gainesville, FL, USA.
authors.forename: Michelle S
authors.initials: MS
authors.lastname: Troche
authors.affiliation: Department of Speech Language and Hearing Sciences, College of Public Health and Health Professions, University of Florida, Gainesville, FL, USA; Center for Movement Disorders and Neurorestoration, College of Medicine, University of Florida, Gainesville, FL, USA.
authors.forename: Alexandra E
authors.initials: AE
authors.lastname: Brandimore
authors.affiliation: Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
authors.forename: Paul W
authors.initials: PW
authors.lastname: Davenport
authors.affiliation: Center for Movement Disorders and Neurorestoration, College of Medicine, University of Florida, Gainesville, FL, USA; Department of Neurology, College of Medicine, University of Florida, Gainesville, FL, USA.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Okun
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003371:Cough / Q000150:complications / Q000503:physiopathology*; D003679:Deglutition / Q000502:physiology*; D003680:Deglutition Disorders / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications / Q000503:physiopathology*; D010366:Peak Expiratory Flow Rate / Q000502:physiology*; D012018:Reflex / Q000502:physiology*
keywords: Airway protection; Cough; Parkinson's disease; Reflex cough; Voluntary cough