High-resolution pharyngeal manometry assessment of swallowing in asymptomatic myotonic dystrophy

【Purpose】We aimed to analyze the high-resolution manometry (HRM) parameters of patients with asymptomatic myotonic dystrophy (MyD) and evaluate the characterize the swallowing pathophysiology in patients with asymptomatic MyD.
【Background】MyD exerts detrimental effects on swallowing from an early stage. However, the swallowing function of patients with MyD has not yet been systematically characterized and entirely understood.
【Method】We conducted a cross-sectional study of patients with MyD who reported little or no dysphagia and underwent HRM and videofluoroscopic swallow study (VFSS) at our hospital. Clinical and demographic profiles, including sex, age, body mass index (BMI), prognostic nutritional index (PNI), and albumin level, were analyzed. The results were compared with those of non-MyD patients with mild swallowing-related symptoms.
【Discussion】Pharyngeal contractility was markedly decreased in the MyD group at all phases of pressure during swallowing: velopharynx, mesopharynx, hypopharynx, and post-deglutitive upper esophageal sphincter (UES). Similarly, UES pressure at rest and UES width at rest was markedly decreased in the MyD group. Patients with MyD were observed to have significantly reduced swallowing muscle strength and a constantly relaxed UES even when they were unaware of their swallowing disorders. Constant UES relaxation may help maintain swallowing, particularly for liquids. However, it hinders patients’ ability to recognize their swallowing problems and may lead to sudden choking episodes. Early risk management and intervention are necessary for patients with MyD, even those unaware of their dysphagia.