Oral Motor Movements and Swallowing in Patients with Myotonic Dystrophy Type 1

Oropharyngeal dysphagia and esophageal motility disorders were found to be the most important causes of aspiration pneumonia in patients with myotonic dystrophy. The purpose of this report was to evaluate clinical characteristics of the oral motor movements and swallowing of individuals with myotonic dystrophy type 1 (DM1) using a standardized clinical protocol and surface electromyography (sEMG). Participants were 40 individuals divided in two groups: G1 composed of 20 adults with DM1 and G2 composed of 20 healthy volunteers paired by age and gender to the individuals in G1. Statistical analysis included one-way ANOVA with two factors for within- and between-group comparisons and Bonferroni correction for multiple comparisons. Patients with DM1 presented deficits in posture, position, and mobility of the oral motor structures, as well as compromised mastication and deglutition. The sEMG data indicated that these patients had longer muscle activations during swallowing events. The longer duration of sEMG in the group of patients with DM1 is possibly related to myotonia and/or incoordination of the muscles involved in the swallowing process or could reflect a physiological adaptation for safe swallowing.