The coordination of breathing and swallowing in Parkinson's disease.

Multiple investigations have determined that healthy adults swallow most often during exhalation and that exhalation regularly follows the swallow, even when a swallow occurs during inhalation. We hypothesized that persons with idiopathic Parkinson's disease would demonstrate impaired breathing and swallowing coordination during spontaneous eating. Twenty-five healthy volunteers and 25 Parkinson's disease patients spontaneously swallowed calibrated pudding and cookie portions while simultaneous nasal airflow and respiratory inductance plethysmography were used to track spontaneous breathing. Surface EMG was used to record the timing of each swallow within the respiratory cycle. When compared to the healthy control group, those with Parkinson's disease swallowed significantly more often during inhalation and at low tidal volumes. The Parkinson's participants also exhibited significantly more postswallow inhalation for both consistencies. Only the healthy subjects exhibited significantly longer deglutitive apnea when swallows that occurred during inhalation were compared with those that occurred during exhalation. The high incidence of oropharyngeal dysphagia and risk of aspiration pneumonia found in Parkinson's disease patients may be partially attributable to impaired coordination of breathing and swallowing.