Expiratory Muscle Strength Training (EMST) in Neuromuscular Disorders

Study Overview
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Brief Summary
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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).

Detailed Description
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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.

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

Conditions
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Oculopharyngeal Muscular Dystrophy, Muscular Dystrophies, Myopathy; Hereditary

Intervention / Treatment
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* Device: Expiratory muscle strength therapy (EMST150, Aspire LLC)


Participation Criteria
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Eligibility Criteria
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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)

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Parallel group, double blind, sham controlled study
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: EMST therapy<br>Participants use the EMST device as per study protocol, set to 50% of the patient's maximal expiratory pressure, as measured by handheld manometer. | Device: Expiratory muscle strength therapy (EMST150, Aspire LLC)<br>* Active therapy calibrated to the participant's maximum expiratory pressure<br>|
| Sham Comparator: Sham EMST therapy<br>Participants use a sham EMST device that has the spring removed as per study protocol, with no significant airflow resistance. | Device: Expiratory muscle strength therapy (EMST150, Aspire LLC)<br>* Active therapy calibrated to the participant's maximum expiratory pressure<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Global Swallowing Function | Global swallowing function is rated from videofluoroscopy swallowing studies (VFSS), using the Dynamic Imaging Grade of Swallowing Toxicity (DIGEST), a validated 5-point scale. Global swallowing function is rated from 0-4: 0 = no pharyngeal dysphagia; 1 = mild; 2 = moderate; 3 = severe; 4 = life-threatening. A lower score is a better outcome. | Change in score from week 0 to week 5 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Global Swallowing Function | Global swallowing function is rated from videofluoroscopy swallowing studies (VFSS), using the Dynamic Imaging Grade of Swallowing Toxicity (DIGEST), a validated 5-point scale. Global swallowing function is rated from 0-4: 0 = no pharyngeal dysphagia; 1 = mild; 2 = moderate; 3 = severe; 4 = life-threatening. | Change in score from week 0 to week 15; change in score from week 5 to week 15. | 
| Maximum expiratory pressure (MEP) | MEP is a measure of respiratory muscle strength and is assessed with a handheld manometer, measured in centimetres of water (cmH2O). A higher score is a better outcome. | Change in score from week 0 to week 5; change in score from week 0 to week 15; change in score from week 5 to week 15. | 
| Volitional cough strength (peak cough flow) | Measure of cough strength that is assessed using a spirometer, measured in litres per minute (L/min). A higher score is a better outcome. | Change in score from week 0 to week 5; change in score from week 0 to week 15; change in score from week 5 to week 15. | 
| Forced vital capacity (FVC) | Measure of how much air is exhaled during forced exhalation and is assessed with a spirometer, measured in litres. A higher score is a better outcome. | Change in score from week 0 to week 5; change in score from week 0 to week 15; change in score from week 5 to week 15. | 
| Oral Intake | A measure daily nutritional and hydration consumption. Oral intake is assessed using the Functional Oral Intake Scale (FOIS), a validated 7-point ordinal scale (1 = no oral intake; 2 = tube dependent with minimal/inconsistent oral intake; 3 = tube supplements with consistent oral intake; 4 = total oral intake in single consistency; 5 = total oral intake of multiple consistencies requiring special preparation; 6 = total oral intake with no special preparation, but must avoid specific foods or liquid items; 7 = total oral intake with no restrictions). A higher score is a better outcome. | Change in score from week 0 to week 5; change in score from week 0 to week 15; change in score from week 5 to week 15. | 
| Self-perceived swallowing impairment | Will be measured using the Eating Assessment Tool-10 (EAT-10), a self-administered, symptom-specific outcome instrument for dysphagia. The EAT-10 allows patients to rate their swallowing symptoms on scale of 0 = no problem to 4 = severe problem. A lower score is a better outcome. | Change in score from week 0 to week 5; change in score from week 0 to week 15; change in score from week 5 to week 15. | 
| Biomarker analyses | An optional blood sample will be collected for biomarker analysis, to identify correlations with clinical response. We will measure genetic biomarkers associated with swallowing function including rs6265, rs165599, rs10835211, rs17601696, and APOE4 genotype status. For these 5 genetic biomarkers, participants will be scored as having zero, one, or two alleles. This information will be used in subgroup analyses for the primary and secondary outcomes. | Baseline measurement (week 0) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Dysphagia, Myopathy, Muscular Dystrophy