Evaluation Method of Swallowing Function by Swallowing Sound and Endoscope in Patients with Dysphagia

Abstract

The purpose of this study was to establish a noninvasive method of evaluating swallowing function using swallowing sounds. Four handicapped patients with congenital or postnatal dysphagia were selected as subjects and five healthy, fully dentate males were selected as control subjects. A jelly on the market for the elderly in need of nursing care was used as the test food. Ultra-sound diagnostic equipment and a heart-sound microphone were used to record tongue movements and swallowing sounds. Moreover, an endoscope was used to observe the bolus and larynx. In all healthy subjects, the first swallowing sound before endoscopic whiteout and the second swallowing sound after endoscopic whiteout were detected in the swallowing test. On the other hand, in all subjects with dysphagia, the first swallowing sound and endoscopic whiteout were detected. However the second swallowing sound was not detected clearly in the 3 subjects with congenital dysphagia. Waveforms of an unclear first swallowing sound or second swallowing sound were observed repeatedly in the subject with postnatal dysphagia. A part of the bolus aspirated into the trachea upon inspiration made some patients choke and cough. Our findings suggest that the bolus remaining around the epiglottis contributes to an increased risk of aspiration and that observation of the second swallowing sound may be effective in the evaluation of swallowing function.