Pharyngoesophageal motor function in patients with myotonic dystrophy.

Six adults with myotonic dystrophy underwent detailed radiological and manometric studies of pharyngoesophageal function. Four of the patients had no history of swallowing dysfunction, while two had very mild symptoms. All patients showed abnormalities of pharyngoesophageal function. Pharyngeal peristalsis was present but of low amplitude. Resting upper esophageal sphincter pressure was diminished, but the sphincter relaxed normally. Peristalsis in the esophageal body was invariably absent in the striated muscle segment of the esophagus and was either absent of decreased in amplitude in the smooth muscle segment. The lower esophageal sphincter was normal. Myotonia did not occur in the sphincters or the esophageal body. These findings suggest that pharyngoesophageal dysfunction is common in patients with myotonic dystrophy, even when clinical symptoms are absent. The abnormalities are probably related to muscle weakness rather than to myotonia in the pharyngeal and esophageal musculature.