Voluntary cough production and swallow dysfunction in Parkinson's disease

Cough is important for airway clearance, particularly if penetration/aspiration of foreign material occurs during swallow. Measures of voluntary cough production from ten male participants with stage II-III Parkinson's disease (PD) who showed no videofluorographic evidence of penetration/aspiration (Group 1) were examined and compared with those of ten male participants with stage II-III PD who showed videofluorographic evidence of penetration/aspiration (Group 2). The degree of penetration/aspiration was expertly judged from the videofluorographic examinations of the participants' sequential swallow of a thin, 30-cc bolus. Measured cough parameters included inspiratory phase duration, inspiratory peak flow, compression phase duration, expiratory peak flow, expiratory rise time, and cough volume acceleration. Results indicated significant group differences for the majority of cough measures, except for inspiratory phase duration and inspiratory peak flow. A modest relationship existed between voluntary cough parameters and penetration/aspiration scores. Decreased ability to adequately clear material from the airway with voluntary cough may exacerbate symptoms resulting from penetration/aspiration, particularly for those with neurodegenerative disease. Measurement of voluntary cough may be useful for the evaluation of airway clearance ability.