Attentional resource allocation and swallowing safety in Parkinson's disease: a dual task study.
BACKGROUND
Aspiration pneumonia is a leading cause of death in persons with Parkinson's disease (PD). Despite this, the mechanisms underlying dysphagia in this population are unclear. To date, researchers have not investigated the effects of varying cognitive demand on objective measures of swallowing safety. This study assessed whether swallowing safety could be disrupted by increasing cognitive demands during the task of swallowing.


METHODS
Twenty participants with moderate PD and dysphagia were tested while completing a novel dual task experimental paradigm under videofluoroscopy. In the dual task condition, participants swallowed 10 cc of thin liquid barium while completing a digits forward task.


RESULTS
Four females and 16 males completed the study. Results revealed differential effects to swallowing safety based on baseline measures of cognitive flexibility and attention. Participants with mild impairment in cognitive flexibility and attention demonstrated cognitive-motor interference with worsening of both swallowing and cognitive performance. In contrast, participants who were most impaired in the domains of cognitive flexibility and attention improved swallowing safety in the dual task condition. Additionally, decreased swallow timing durations existed in the dual task condition compared to the single task condition.


CONCLUSIONS
The results of this study support the hypothesis that supramedullary drive can influence the swallowing plan. Additionally, this study highlights the need for cognitive taxing during swallowing evaluations.
Department of Speech, Language, and Hearing Sciences, University of Florida, USA; Center for Movement Disorders and Neurorestoration, University of Florida, USA; Brain Rehabilitation Research Center, Malcom Randall VA, Gainesville, FL, USA. Electronic address: michi81@phhp.ufl.edu.
Michelle S
MS
Troche
Department of Neurology, University of Florida, USA; Center for Movement Disorders and Neurorestoration, University of Florida, USA.
Michael S
MS
Okun
Department of Speech, Language, and Hearing Sciences, University of Florida, USA; Center for Movement Disorders and Neurorestoration, University of Florida, USA; Brain Rehabilitation Research Center, Malcom Randall VA, Gainesville, FL, USA.
John C
JC
Rosenbek
Department of Speech, Language, and Hearing Sciences, University of Florida, USA.
Lori J
LJ
Altmann
Brain Rehabilitation Research Center, Malcom Randall VA, Gainesville, FL, USA; Department of Communication Sciences and Disorders, Jacksonville University, Jacksonville, FL, USA.
Christine M
CM
Sapienza
D000368:Aged; D000369:Aged, 80 and over; D001288:Attention / Q000502:physiology*; D003071:Cognition / Q000502:physiology; D015331:Cohort Studies; D003679:Deglutition / Q000502:physiology; D003680:Deglutition Disorders / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D010300:Parkinson Disease / Q000150:complications* / Q000503:physiopathology*
Aspiration; Cognition; Dual task; Dysphagia; Parkinson's disease