Primary Outcomes

Description: 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.

Measure: Global Swallowing Function

Time: Change in score from week 0 to week 5

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Secondary Outcomes

Description: 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.

Measure: Global Swallowing Function

Time: Change in score from week 0 to week 15; change in score from week 5 to week 15.

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Description: 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.

Measure: Maximum expiratory pressure (MEP)

Time: 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.

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Description: Measure of cough strength that is assessed using a spirometer, measured in litres per minute (L/min). A higher score is a better outcome.

Measure: Volitional cough strength (peak cough flow)

Time: 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.

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Description: 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.

Measure: Forced vital capacity (FVC)

Time: 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.

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Description: 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.

Measure: Oral Intake

Time: 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.

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Description: 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.

Measure: Self-perceived swallowing impairment

Time: 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.

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Description: 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.

Measure: Biomarker analyses

Time: Baseline measurement (week 0)

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