The Pathophysiology of Sarcopenic Dysphagia: Consideration of Videofluoroscopic Swallowing Studies

Background The pathophysiology of sarcopenic dysphagia remains insufficiently understood. The aim of this study was to clarify the pathophysiology of sarcopenic dysphagia by analyzing data from videofluoroscopic swallowing studies, focusing on the pharyngeal constriction ratio (PCR) as an objective indicator of pharyngeal contraction strength and on the anterior movement distance of the hyoid (AMDH), which contributes to the opening of the upper esophageal sphincter. Methods The study had a cross-sectional design and included 52 patients aged 65 years or older who were deemed to require a videofluoroscopic swallowing study. Data obtained during the swallowing of 5 mL of a moderately thick liquid were used to calculate the pharyngeal constriction ratio and the anterior movement distance of the hyoid. Sarcopenic dysphagia is a swallowing disorder caused by sarcopenia of the whole body, including the swallowing muscles. The patients were classified into a sarcopenic dysphagia group (n = 27) and a control group (no sarcopenia and no dysphagia; n = 25). The pharyngeal constriction ratio and anterior movement distance of the hyoid were compared between the two groups. Results The pharyngeal constriction ratio was significantly higher (r = 0.76; p < 0.001), and the anterior movement distance of the hyoid was significantly shorter (r = 0.30; p = 0.031) in the sarcopenic dysphagia group. Conclusions The pathophysiology of sarcopenic dysphagia may involve reduced pharyngeal contraction strength and decreased anterior movement distance of the hyoid.