Comparison of Two Methods for Inducing Reflex Cough in Patients With Parkinson's Disease, With and Without Dysphagia.
Aspiration pneumonia is a common cause of death in people with Parkinson's disease (PD). Dysfunctional swallowing occurs in the majority of people with PD, and research has shown that cough function is also impaired. Previous studies suggest that testing reflex cough by having participants inhale a cough-inducing stimulus through a nebulizer may be a reliable indicator of swallowing dysfunction, or dysphagia. The primary goal of this study was to determine the cough response to two different cough-inducing stimuli in people with and without PD. The second goal of this study was to compare the cough response to the two different stimuli in people with PD, with and without swallowing dysfunction. Seventy adults (49 healthy and 21 with PD) participated in the study. Aerosolized water (fog) and 200 μM capsaicin were used to induce cough. Each substance was placed in a small, hand-held nebulizer, and presented to the participant. Each cough stimulus was presented three times. The total number of coughs produced to each stimulus trial was recorded. All participants coughed more to capsaicin versus fog (p < 0.001). A categorical 'responder' and 'non-responder' variable for the fog stimulus, defined as whether or not the participant coughed at least two times to two of three presentations of the stimulus, yields sensitivity of 77.8 % and a specificity of 90.9 % for identifying PD participants with and without dysphagia. The data show a differential response of the PD participants to the capsaicin versus fog stimuli. Clinically, this finding may allow for earlier identification of people with PD who are in need of a swallowing evaluation. As well, there are implications for the neural control of cough in this patient population.
Department of Speech Language and Hearing Sciences, University of Florida, Box 117420, 336 Dauer Hall, Gainesville, FL, 32611, USA. kwheeler@ufl.edu.
Karen W
KW
Hegland
Department of Biobehavioral Sciences, Teacher's College, Columbia University, New York, USA.
Michelle S
MS
Troche
Department of Speech Language and Hearing Sciences, University of Florida, Box 117420, 336 Dauer Hall, Gainesville, FL, 32611, USA.
Alexandra
A
Brandimore
Department of Neurology, University of Florida, Gainesville, USA.
Michael S
MS
Okun
Department of Physiological Sciences, University of Florida, Gainesville, USA.
Paul W
PW
Davenport
D000293:Adolescent; D000336:Aerosols; D000368:Aged; D002211:Capsaicin / Q000494:pharmacology*; D003371:Cough / Q000139:chemically induced* / Q000503:physiopathology; D003680:Deglutition Disorders / Q000150:complications / Q000503:physiopathology*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications / Q000503:physiopathology*; D012018:Reflex / Q000187:drug effects*; D018689:Sensory System Agents / Q000494:pharmacology*; D014867:Water / Q000494:pharmacology*; D055815:Young Adult
D000336:Aerosols; D018689:Sensory System Agents; D014867:Water; D002211:Capsaicin
Cough; Deglutition; Deglutition disorders; Dysphagia; Parkinson’s disease; Screening