Timing of Pharyngeal Swallow Events in Chagas’ Disease

BACKGROUND: Esophageal involvement by Chagas’ disease causes a significative decrease in the number of neurons of the esophageal myenteric plexus, causing an impairment of esophageal motility with the same alterations described in primary esophageal achalasia. There is also a longer duration of pharyngeal transit, which might be consequent of the involvement of the central control of swallowing by the disease, or an adaptation of the pharynx to the difficult bolus transit through the esophagus, which could contribute to the complaint of dysphagia. METHODS: We studied, by videofluoroscopy, the sequence and timings of pharyngeal bolus transit in 16 patients with esophageal involvement by Chagas’ disease and 12 healthy volunteers. Each subject swallowed in duplicate 5 mL and 10 mL of liquid and paste boluses. RESULTS: There was no difference between Chagas’ disease patients and normal volunteers in the sequence and timing of events associated with pharyngeal bolus flow, for liquid and paste boluses, and for 5 mL and 10 mL. CONCLUSION: The timing and sequence of swallow pharyngeal events of patients with Chagas’ disease do not differ from that of control subjects, which suggested that the central control of swallowing is not impaired by the disease.