Respiratory and Real-time Dynamics in Exercise-Induced Paradoxical Vocal Fold Motion

Respiratory and Real-time Dynamics in Exercise-Induced Paradoxical Vocal Fold Motion

The overall objectives of the proposed research are to:

1. Evaluate the diagnostic validity of a novel mechano-acoustic signatures of task-characteristic activity during symptomatic and asymptomatic breathing in Exercise-Induced Laryngeal Obstruction (EILO) patients with the use of a novel miniature, soft wearable skin-mounted device,
2. Identify the mechanism/s of paradoxical respiratory control in EILO by quantifying the relationship between pulmonary mechanics, partial pressure of carbon dioxide (PCO2) maintenance, and vocal fold aperture prior to and during symptomatic and asymptomatic exercise ventilation, and
3. Identify unique biophysiological factors contributing to EILO among exercisers with and without EILO. Findings will be highly novel and clinically significant for early identification and management of EILO.

The main study will enroll 60 participants with EILO and 60 without EILO to complete three separate visits:

1. Exercise treadmill study
2. Free running with the device on the neck
3. Undergoing MRI (Magnetic Resonance Imaging) of the vocal tract.

An additional substudy limited to the mechanoacoustic device will enroll 10 additional participants (5 healthy and 5 with EILO). These participants will complete a single study visit during which the mechano-acoustic device will be worn during four sequential conditions.

Main Study

At the first study visit, participants will sign informed consent, complete study questionnaires, have their height, weight, and body composition measured, and perform resting pulmonary function tests. Participants will then warm up on the treadmill for 10 minutes. An endoscope will be placed in one nostril until the vocal folds are visible, and subjects will be fitted with a chest strap heart rate monitor, an oro-nasal face mask, and the mechanoacoustic device. This sensor is placed on the neck with a velcro band. Participants will then undergo a graded exercise test during which a carbon-dioxide enriched gas mixture will be administered. The amount of the gas mixture will be titrated based on measures of the participant's breathing and lung function. This visit will be video recorded.

At the second study visit, participants will be asked to again wear the mechanoacoustic device while free running for 10 minutes in a large room or on a track. This visit will be video-recorded.

At the third study visit, participants will be asked to undergo an MRI scan, during which they will perform a variety of breathing exercises including rest breathing, rapid breathing, pursed lip breathing, sniff, and open mouth breathing. Research personnel will instruct participants in the various breathing techniques prior to the scan.

Device Only Substudy

Participants will be evaluated using the mechanoacoustic device only at a single visit. Participants will wear the neck device during four sequential conditions: seated rest indoors (15 minutes); standing outdoors (15 minutes); walking outdoors (15 minutes); running outdoors (15 minutes). This visit will be video-recorded.

Inclusion Criteria for Exercise-Induced Laryngeal Obstruction (EILO):

• Physically active >2.5 hours per week
• Patients with EILO, as diagnosed by routine clinical examination by physician and/or speech language pathologist
• Age range of 18-26 years
• Greater difficulty breathing inside compared to out and difficulty breathing which is exacerbated at peak exercise and stops 1-5 minutes after exercise
• Score of 7 or higher on the Dyspnea Index, which is a validated instrument to capture participant self-report of upper airway dyspnea symptoms.
• Classified as low risk, based on the modified Physical Activity Readiness Questionnaire (PAR-Q) questionnaire, body mass index, and non-smoking status
• Negative history of voice disorders, self-report of cognitive difficulties, asthma or other lung disease, cardiac disease, serious orthopedic injuries, current uncontrolled hypertension, illicit drug use, seizure/epilepsy, claustrophobia, use of beta blockers.
• No metallic, mechanical or magnetic implants such as cardiac devices, cochlear, or other non-removable ear implants, any prosthesis, stents, deep brain stimulator, etc.

Inclusion Criteria for Controls

• Physically active >2.5 hours per week
• Age range of 18-26 years
• Classified as low risk, based on the modified PAR-Q questionnaire, body mass index, and non-smoking status
• Negative history of voice disorders, self-report of cognitive difficulties, asthma or other lung disease, cardiac disease, serious orthopedic injuries, current uncontrolled hypertension, illicit drug use, seizure/epilepsy, claustrophobia, use of beta blockers.
• No metallic, mechanical or magnetic implants such as cardiac devices, cochlear, or other non-removable ear implants, any prosthesis, stents, deep brain stimulator, etc.

Exclusion Criteria for EILO:

• Individuals older than 26 years and younger than 18 years of age.
• Women who are pregnant or could possibly be pregnant.
• BMI > 25 kg/m2
• A 'yes' answer to any of the 14 questions on the PAR-Q pre-participation questionnaire
• Current smoker
• Positive history of voice disorders, self-report of cognitive difficulties, asthma or other lung disease, cardiac disease, serious orthopedic injuries, current uncontrolled hypertension, illicit drug use, seizure/epilepsy, claustrophobia, use of beta blockers.
• Presence of metallic, mechanical or magnetic implants such as cardiac devices, cochlear, or other non-removable ear implants, any prosthesis, stents, deep brain stimulator, etc.
• Do not report the following: Greater difficulty breathing inside compared to out and difficulty breathing which is exacerbated at peak exercise and stops 1-5 minutes after exercise

Exclusion Criteria for Controls

• Individuals older than 26 years and younger than 18 years of age.
• Women who are pregnant or could possibly be pregnant.
• BMI > 25 kg/m2
• A 'yes' answer to any of the 14 questions on the PAR-Q pre-participation questionnaire
• Current smoker
• Positive history of voice disorders, self-report of cognitive difficulties, asthma or other lung disease, cardiac disease, serious orthopedic injuries, current uncontrolled hypertension, illicit drug use, seizure/epilepsy, claustrophobia, use of beta blockers.
• Presence of metallic, mechanical or magnetic implants such as cardiac devices, cochlear, or other non-removable ear implants, any prosthesis, stents, deep brain stimulator, etc.
• Significant acute or chronic medical, neurologic, or illness in the patient that, in the judgment of the Principal Investigator, could compromise subject safety, limit the ability to complete the study, and/or compromise the objectives of the study