[Imaging and pathological studies on the esophageal dysfunction in patients with myotonic dystrophy]

The purpose of this study is to clarify a correlation between the esophageal dysfunction and suffocation after meals in patients with myotonic dystrophy (MD) and to find how to prevent such accidents. Using imaging methods, we examined eight patients with MD (six of them had difficulty in swallowing), four patients with other neuromuscular diseases (Fukuyama-type congenital muscular dystrophy, congenital myopathy, Machado-Joseph disease, and Duchenne's muscular dystrophy), and two healthy control subjects. We also investigated material from an autopsy of another patient with MD who died of suffocation. In all patients with MD, fluoroscopy and computed tomography showed dilatation of the esophagus, particularly in the proximal third, and residual contrast media in the esophagus 15 to 40 minutes after swallowing. In histologic studies, morphologic changes were confined to the esophageal striated muscle in a patient with MD. These results indicate that regurgitation from the esophagus to the trachea happens more than 40 minutes after swallowing in patients with MD and that histological alterations of striated muscle are primary causes of the esophageal dysfunction. From these findings, we propose that patients with MD should not lie down at least 40 minutes after meals whether they complain of difficulty in swallowing or not.