Laryngeal Nerve Block for Chronic Cough

Study Overview
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Brief Summary
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The purpose of this study is to study the potential benefit of treating chronic neurogenic cough by blocking the nerve responsible for the disease with an injection of local anesthetic/steroid mixture versus a placebo.

Detailed Description
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This study will be performed by asking participants to fill out multiple questionnaires on the symptoms of their cough, and undergo cough testing by inhaling an airway irritant and monitoring the number of coughs after inhalation of the irritant. Subjects would then undergo the treatment and have an injection of either local anesthetic/steroid mixture or a placebo (normal saline) around the nerve that gives feeling to the portion of the voice box responsible for chronic neurogenic cough. After the injection you will be asked to repeat the cough testing and questionnaires 30 minutes, 1 weeks, and at 6 weeks post injection. After the initial six weeks, patients will cross over and repeat the same process with the opposite treatment (either local anesthetic/steroid mixture or placebo) from their previous injection. The total time of participation is about 12 weeks and we hope to recruit 40 subjects.

Official Title
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Prospective, Single-Blind Randomized Trial of in Office Superior Laryngeal Nerve Block for the Treatment of Chronic Neurogenic Cough

Conditions
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Laryngeal Nerve Block, Chronic Neurogenic Cough, Laryngeal Hypersensitivity

Intervention / Treatment
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* Drug: Steroid/Anesthesia Mixture
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18 years and older Previously or Newly Diagnosed Chronic Neurogenic Cough Exclusion Criteria: History of Laryngeal Surgery or External Beam Radiation Current Smokers Known Allergy or Sensitivity to Local Anesthetics Uncontrolled Pulmonary, SinoNasal, or GastroIntestinal Pathology leading to Refractory Chronic Cough

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: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Intervention (Steroid/Anesthetic Mixture)<br>The steroid/anesthetic mixture will be injected via a 27-gauge needle once at the baseline or during the 6-week crossover timepoint. | Drug: Steroid/Anesthesia Mixture<br>* Steroid will be Triamcinolone Acetonide (40mg/mL). Anesthetic will be 0.5% bupivacaine with 1:100,000 epinephrine. These will be pre-mixed by a qualified personnel within the ENT department.<br>|
| Placebo Comparator: Placebo (Normal Saline)<br>The placebo (Normal Saline) will be injected via a 27-gauge needle once at the baseline or during the 6-week crossover timepoint. | Drug: Placebo<br>* 2 mL of Normal Saline<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intervention vs. Placebo in Neurogenic Cough using Capsaicin Challenge | Objectively evaluate the efficacy of blockade of the internal branch of the superior laryngeal nerve with local anesthetic/steroid mixture compared to normal saline placebo in treating chronic neurogenic cough using capsaicin challenge testing to measure cough sensitivity and urge to cough | Comparing Changes at Pretreatment, at 30 minutes post treatment, at 1 week post treatment, and at 6 weeks post treatment | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intervention vs. Placebo in Neurogenic Cough using the Newcastle Laryngeal Hypersensitivity Questionnaire | Subjectively evaluate the efficacy of superior laryngeal nerve block (intervention) vs. placebo using the Newcastle Laryngeal Hypersensitivity Questionnaire (NLHQ). This Questionnaire is scaled from 1 to 7. 1 indicates All of the Time while 7 reflects None of the Time. | Pretreatment, 30 minutes post treatment, 1 week post treatment, 6 weeks post treatment | 
| Intervention vs. Placebo in Neurogenic Cough using the Urge to Cough Scale | Subjectively evaluate the efficacy of superior laryngeal nerve block (intervention) vs. placebo using the Urge to Cough Scale. Higher score indicates more urge, while lower score reflects less of an urge to cough. | Pretreatment, 30 minutes post treatment, 1 week post treatment, 6 weeks post treatment | 
| Intervention vs. Placebo in Neurogenic Cough using the Central Sensitization Inventory | Subjectively evaluate the efficacy of superior laryngeal nerve block (intervention) vs. placebo using the Central Sensitization Inventory (CSI). Scale is ranked as Never, Rarely, Sometimes, Often, and Always and has various symptoms listed. | Pretreatment, 30 minutes post treatment, 1 week post treatment, 6 weeks post treatment | 
| Quality of Life Measurements | Analyze quality of life measurements of patients undergoing superior laryngeal nerve block compared to placebo as measured by the Leicester Cough Questionnaire (LCQ). Scale is from a 1 to 7. The higher the score/rating represents less of a problem while a lower score/rating represents more of a problem. | Pretreatment, 1 week post treatment, 6 weeks post treatment | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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cough, chronic cough, neurogenic cough, laryngeal nerve block