The Efficacy of Capsaicin Sensitivity Testing in Patients With Irritable Larynx Syndrome

NCT02065128 | Withdrawn

• 1 other identifier: 14-005
• Study Type: observational
• Target: N/A
• Locations: 1 country
• Sites: 1

Brief Summary

Irritable larynx syndrome (ILS) is a hyperkinetic laryngeal dysfunction that is characterized by a persistent cough, voice changes, or breathing difficulties, which are often triggered by an irritant. Diagnosis of ILS is difficult and typically made via a thorough review of the clinical history and, occasionally, the patient's reaction to an odor-provocation test. Standard treatment for ILS is behavioural therapy with a speech language pathologist (SLP), which provides symptom improvement for most patients. However, currently, there are no objective measures of the upper airway hyper-responsiveness in this condition to assist in diagnosing and monitoring disease severity. Since the cough is irritant-based, it is anticipated that patients with ILS will have a hypersensitivity to the irritant capsaicin. Capsaicin is the active component of chili peppers and is what makes them hot. The capsaicin cough challenge is a well recognized test that involves inhaling different concentrations of capsaicin solutions to determine a cough reflex sensitivity. The purpose of this research study is to confirm that ILS patients have a hypersensitivity to capsaicin compared to healthy volunteers. If a hypersensitivity is observed in ILS patients, the second objective of this study will be to see if behavioural therapy improves the cough reflex sensitivity in this patient population.

Conditions

Cough; Larynx

Outcome Measures

Primary Outcomes (1)

• cough reflex sensitivity

  measured via the capsaicin cough challenge test

  measured before and after behavioural therapy for ILS participants (approximately 5 month time frame); measured once for healthy volunteers

Study Arms (2)

Healthy Volunteers

Capsaicin cough challenge test. The ILS participants will be asked to attend two study visits at the pulmonary function laboratory at SMH; one before behavioural therapy and one after. The healthy volunteers will be asked to attend one study visit. At each of these study visits, the ILS participants will complete the Leicester Cough Questionnaire (LCQ) (Appendix B) and the Dyspnea Index (DI) Questionnaire (Appendix C). The LCQ is a valid assessment tool for evaluating the impact of cough on QoL.19 The DI is a short, validated questionnaire used to quantify a patient's symptoms of dyspnea.20 Following completion of the questionnaires, participants will complete a capsaicin cough challenge test, which is discussed in the following section.

Other: Capsaicin cough challenge test

Irritable Larynx Syndrome Patients

Capsaicin cough challenge test. The ILS participants will be asked to attend two study visits at the pulmonary function laboratory at SMH; one before behavioural therapy and one after. The healthy volunteers will be asked to attend one study visit. At each of these study visits, the ILS participants will complete the Leicester Cough Questionnaire (LCQ) (Appendix B) and the Dyspnea Index (DI) Questionnaire (Appendix C). The LCQ is a valid assessment tool for evaluating the impact of cough on QoL.19 The DI is a short, validated questionnaire used to quantify a patient's symptoms of dyspnea.20 Following completion of the questionnaires, participants will complete a capsaicin cough challenge test, which is discussed in the following section.

Interventions

Capsaicin cough challenge test OTHER

The capsaicin cough challenge testing will be conducted in the pulmonary function laboratory at SMH by a pulmonary function technologist. The test involves having the participant inhale increasing concentrations of capsaicin solutions and assessing their response. The tidal breathing method and solution preparation presented by Nejla, et al. 12 will be used to conduct this testing. The tidal breathing method is preferred to the alternative dosimeter method as it produces similar results with lower capsaicin concentrations thereby resulting in less throat irritation for the participant. The technique is detailed in the following sections.

Healthy Volunteers

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

ILS Patients

You may qualify if:

• Diagnosis of ILS as per the St Michael's voice clinic consultation
• Methacholine test performed
• Negative/borderline result for methacholine test and/or negative/incomplete response for asthma treatment
• Negative test result for gastroesophageal reflux or negative/incomplete response to reflux treatment
• Allergy test has been completed with negative result or does not account for all symptoms
• Agreed to behavioural therapy in SMH Voice Disorders Clinic

You may not qualify if:

• Active smoker
• Active respiratory disease (e.g., COPD, pulmonary fibrosis, lung malignancy.)
• Taking an ACE inhibitor
• Pregnant and/or breastfeeding
• Impaired liver and/or renal function
• Neurological disorder
• Psychiatric condition (outside of depression or anxiety)
• Healthy Volunteers:
• Active smoker
• Active respiratory disease (e.g. COPD, asthma)
• ILS diagnosis
• Chronic cough diagnosis
• Known hypersensitivity to capsaicin

Sponsors & Collaborators

• Unity Health Toronto: lead

Study Sites (1)

St. Michael's Hospital

Toronto, Ontario, M5B 1W8, Canada

Location

MeSH Terms

Conditions

Cough; Laryngeal Diseases

Condition Hierarchy (Ancestors)

Respiration Disorders; Respiratory Tract Diseases; Signs and Symptoms, Respiratory; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Otorhinolaryngologic Diseases

Study Officials

• Jennifer Anderson, MD, FRCS(C)

  Chief, Department of Otolaryngology - Head and Neck Surgery

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: February 11, 2014
• First Posted: February 17, 2014
• Study Start: August 1, 2017
• Primary Completion: August 1, 2017
• Study Completion: August 1, 2017
• Last Updated: August 1, 2017

Record last verified: 2017-07

Locations

CA (1)