Expiratory Muscle Strength Training (EMST) in Neuromuscular Disorders

Interventional Study of Expiratory Muscle Strength Training as a Treatment in Neuromuscular Disorders

The purpose of this study is to investigate the impact of expiratory muscle strength training (EMST) on the swallowing, breathing, oral intake, quality of life and cough function of people with oculopharyngeal muscular dystrophy (OPMD).

Outline:

Twenty participants with OPMD, with dysphagia, will be recruited from Neuromuscular clinics within Calgary. The investigators will enrol patients in a parallel group, sham-controlled, randomized clinical trial, with 10 participants in each group (active EMST and sham EMST).

Participants will have baseline measurements of: (i) global swallowing function via modified barium swallow study, (ii) maximum expiratory pressure, (iii) voluntary cough spirometry, (iv) forced vital capacity, (v) functional oral intake, (vi) patient report of self-perceived swallowing impairment (EAT-10 Questionnaire), and (vii) biomarker analyses.

Participants will undergo 5-weeks of EMST (active or sham). All baseline measurements will be repeated after 5-weeks of EMST and 10-weeks post-EMST to measure durability of effect.

Outcomes:

The end-goal of the current research is to obtain preliminary data for the benefit of EMST in a new study population, and direct future studies that may provide evidence for a new standard of care in treating neuromuscular diagnoses.

Inclusion Criteria:

• Diagnosis of oculopharyngeal muscular dystrophy (OPMD)
• 18 years of age or older
• Must be capable of providing informed consent
• Must be able to undergo respiratory function testing and swallowing studies
• Must have a forced vital capacity (FVC) greater than 60%
• A score of 3 or greater on the Eating Assessment Tool-10 (EAT-10; self-administered, symptom-specific outcome instrument for dysphagia. A score of 3 or greater indicates increased stress around eating)
• A score of 26 or greater on the Montreal Cognitive Assessment (MoCA; 30-point screening assessment used for detecting cognitive impairment. A score of 26 or greater is considered to be within functional limits.)

Exclusion Criteria:

• Severe coronary artery disease
• Acute myocardial infarction
• Moderate to severe hypovolemia
• Acute neurological events
• Unstable cardiac status
• Recent hernia
• Severe chronic obstructive pulmonary disease (COPD)
• Uncontrolled reflux issues
• Women who are pregnant, or who suspect they may be pregnant
• Cognitive impairment that would prevent comprehension of instructions and adherence to intervention guidelines (a score of less than 26 points on the MoCA)