Visceral Changes in Myotonic Dystrophy

Abstract

Alteration of the muscular component of viscera can be a dominant feature of myotonic dystrophy. Twelve patients with varying degrees of clinical involvement of somatic muscles were studied. Manometric evaluation of the pharynx and esophagus was done in 10 patients, 6 with dysphagia. Not only was there a marked weakness of the pharyngeal swallowing contraction in 5 of 8 patients examined, but 9 of 10 patients had similar diminution of the pressure waves in the portion of the esophagus which had a smooth muscle wall. Superior and inferior esophageal sphincter pressures were also diminished. Cineroentgenograms confirmed these manometric findings in 8 patients. Diffuse involvement of smooth muscle of the bowel was implicated. There was no significant clinical evidence of gallbladder disease. Eight patients had electrocardiograms of which 2 showed 1st degree A-V block, 1 left bundle branch block and another incomplete right bundle branch block. Nonspecific T-wave changes were noted. Myotonic dystrophy can significantly affect the muscular component of internal organs, and this disease may produce symptoms seemingly unrelated to (and sometimes preceding) its striking peripheral manifestations.