Tongue pressure during swallowing is decreased in patients with Duchenne muscular dystrophy

Although dysphagia is a life-threatening problem in patients with Duchenne muscular dystrophy (DMD), the pathophysiology of oral stage dysphagia is yet to be understood. The present study investigated the tongue motor deficit during swallowing in patients with DMD and its relationship with disease-specific palatal morphology. Tongue pressure during swallowing water was recorded in 11 male patients with DMD and 11 age- and sex-matched healthy subjects using an intra-oral sensor with five measuring points, and the state of tongue pressure production was compared between the groups. Palatal morphology was assessed by a non-contact three-dimensional scanner on maxillary plaster models. In patients with DMD, the normal sequential order of tongue-palate contact was lost and the maximal magnitude and integrated value of tongue pressure on the mid-anterior part of palate were smaller than those in healthy subjects. The width of the palate in patients was greater than that in healthy subjects and the depth of the palate in patients had a negative correlation with tongue pressure magnitude on the median palate. Our results suggested that the deteriorated tongue motor kinetics prevented tongue movement during swallowing that was appropriate for the depth of the palate and affects the state of tongue pressure production during swallowing.