The relationship of esophageal and pulmonary involvement in myotonia distrophica was investigated in 11 men and two women. Esophageal motility tests demonstrated smooth and/or skeletal muscle involvement in each patient. Amplitudes of contractions were significantly reduced and only 50% of the swallows elicited esophageal contractions. Six of 13 patients had dysphagia, but there was no correlation with esophageal impairment. Nine patients had pulmonary function studies (forced vital capacity [FVC], one-second forced expiratory volume [FEV1], and maximum voluntary ventilation [MVV]) which were compatible with a restrictive ventilatory defect. Pulmonary infections were common and one patient died from aspirational pneumonia and respiratory failure during the study. This study suggests that the stage is set early in myotonia dystrophica for pulmonary complications from weakened chest bellows, and that the inability of the esophagus to adequately empty may allow nocturnal aspirations and further pulmonary embarrassment.
Garrett JM, DuBose TD, Jackson JE, Norman JR. Esophageal and Pulmonary Disturbances in Myotonia Dystrophica. Arch Intern Med. 1969;123(1):26-32. doi:10.1001/archinte.1969.00300110028005