We evaluated the pathophysiology of dysphagia considered to be induced by benzodiazepine using high-resolution manometry (HRM). A 53-year-old man with Parkinson disease had had dysphagia for over 3 months. He had been taking several benzodiazepines for more than four years. Two weeks after discontinuation of the benzodiazepines, HRM revealed increased pharyngeal contractility and residual pressure at the upper esophageal sphincter. A video-fluoroscopic swallowing study showed improved pharyngeal bolus passage. Benzodiazepine-induced dysphagia may be due to the muscle relaxant effects on the swallowing muscles and attenuation of the barrier function which prevents reflux from the esophagus into the pharynx.
Keywords: Parkinson disease; drug-induced dysphagia; muscle relaxant effect; pharyngeal contraction; upper esophageal sphincter.