Variability of Oral and Pharyngeal Transit Between Two Consecutive Swallows in Chagas’ Disease

Abstract

Background: Chagas' disease causes dysphagia, regurgitation and retention of food in the esophageal body. Patients have longer pha-ryngeal clearance, which might be consequent of the involvement of the central nervous system or an adaptation to the esophageal transit impairment. If there is central nervous system involvement by the disease, we expect a larger difference in the oral and pharyn-geal phases of swallowing between two consecutive swallows than that seen in controls. Our objective was to evaluate the difference of oral and pharyngeal transit duration between two consecutive swallows in patients with Chagas' disease compared with controls. Methods: By videofluoroscopy, the duration of oral and pharyn-geal transit, pharyngeal clearance, upper esophageal sphincter tran-sit, hyoid movement and oropharyngeal transit was measured in 17 patients with Chagas' disease and 15 asymptomatic volunteers. Each subject swallowed in duplicate and in sequence 5 mL and 10 mL of barium liquid and 5 mL and 10 mL of barium paste boluses. The differences were calculated between the two swallows of each volume and consistency in patients and controls. Results: There were no differences between controls and patients in the values of the differences between the two consecutive swal-lows, except for the hyoid movement duration of the 5 mL liquid bolus, causing a higher difference in controls than in patients. Conclusion: Oral and pharyngeal transit variation between two consecutive swallows is similar between patients with Chagas' dis-ease and controls, which suggests that the longer pharyngeal clear-ance duration previously described is not a consequence of impair-ment of the central nervous system control of swallowing.