MECHANISMS OF ORAL-PHARYNGEAL DYSPHAGIA IN PATIENTS WITH PARKINSONS-DISEASE

Background & Aims: Oral-pharyngeal dysphagia in Parkinson's disease is well recognized. The aim of this study was to establish the mechanism s of oral-pharyngeal dysphagia in these patients. Methods: Using simul taneous videoradiography and pharyngeal manometry, we studied 19 patie nts with Parkinson's disease (12 with oral-pharyngeal dysphagia and 7 without oral-pharyngeal dysphagia) and compared them with 23 healthy c ontrols. Results: The clinical severity of Parkinson's disease predict ed neither the presence nor the severity of dysphagia. Minor alteratio ns in oral function were common in controls and patients, but pharynge al dysfunction was significantly more prevalent in patients. Incomplet e upper esophageal sphincter (UES) relaxation was present in 4 patient s (21%), all of whom showed increased hypopharyngeal intrabolus pressu re, but not all of whom had a diminished UES opening, The patients had a reduced UES diameter (P = 0.004) and a higher intrabolus pressure c ompared with the controls (P = 0.007). Pharyngeal contraction pressure s were lower in patients, but 6 patients with dysphagia and an abnorma l pharyngeal wall motion had normal peak pressures. Conclusions: An in complete UES relaxation and a reduced UES opening, both associated wit h high intrabolus pressure, are prevalent in Parkinson's disease. Oral -pharyngeal dysphagia in Parkinson's disease is multifactorial, with t he majority of patients showing oral and pharyngeal dysfunction, even before the clinical expression of dysphagia. Impaired pharyngeal bolus transport is the major determinant of dysphagia.