Swallowing in myotonic muscular dystrophy: A videofluoroscopic study

Objectives: (1) To determine how swallow function in patients with myotonic muscular dystrophy (MD) differs from that of healthy controls, (2) to identify the contributors to and predictors of improvement, and (3) to evaluate strategies that facilitate swallowing. Design: Observational. Setting: University medical center. Participants: Eighteen adults with myotonic MD (age range, 24-58yr) and 60 healthy adult control subjects (age range, 18-73yr). Interventions: Swallow facilitation strategies. Main Outcome Measures: Between-group comparisons of mean bolus transit times, onsets of swallow gestures, and displacement measures obtained by dynamic lateral view videofluoroscopy. Results: The MD patients' bolus transit times were significantly longer, and onsets of some swallow gestures were significantly delayed. Upper esophageal sphincter opening was prolonged (myotonic MD, .61 ± .13s; control, .5 ± .11s). Hyoid displacement was significantly less in men with myotonic MD (1.9 ± .05cm) than in male controls (2.4 ± .68cm); this difference was not observed between control and myotonic women. Of particular importance was the markedly reduced pharyngeal constriction found in the MD group. Conclusions: Weakness associated with the disease, as opposed to myotonia, was the most significant contributor to impairment. Persons at risk for aspiration may be identified by a measure of pharyngeal area. Selected strategies to facilitate pharyngeal clearing are worthwhile.