Neurophysiology of Cough Reflex Hypersensitivity (NOTCH)
Central sensitisation is an increase in the excitability of nerves within the central nervous system, which can lead to heightened sensitivity to certain stimuli. This process is involved in some chronic pain conditions e.g. migraines and non−cardiac chest pain. Recent work by our group suggests central sensitisation may be an important mechanism leading to chronic cough.
The main questions in this study include:
- Can the investigators induce temporary central sensitisation of the cough reflex in healthy volunteers for testing of new medications?
- Can the investigators demonstrate exaggerated sensitisation in patients with chronic cough (indicating these patients are already centrally sensitised)?
In animal studies, acid infusion into the gullet (oesophagus) is able to induce central sensitisation of the cough reflex. Acid infusion into the oesophagus has also been shown to induce central sensitisation in human healthy volunteers, increasing the sensitivity to pain on the front of the chest but this study did not test the the cough reflex. Using human participants, the investigators plan to test whether acid infusion into the oesophagus increases the sensitivity of the cough reflex in healthy volunteers and also patients complaining of chronic cough.
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Basic Science
|Official Title:||Pilot Study Investigating Central Sensitisation of the Cough Reflex in Subjects With Chronic Cough and Healthy Volunteers|
- Effect of oesophageal acid infusion on cough reflex sensitivity in chronic cough patients compared to healthy controls. [ Time Frame: baseline, immediatley after infusion, 90 minutes post infusion, 180 minutes post infusion, 24 hours after baseline ] [ Designated as safety issue: No ]Outcome measures include; cough reflex sensitivity, pain threshold measures, 24 hour objective cough rate
|Study Start Date:||March 2010|
|Study Completion Date:||February 2013|
|Primary Completion Date:||September 2012 (Final data collection date for primary outcome measure)|
|Active Comparator: Hydrochloric acid infusion||
Other: Hydrochloric acid (0.15 molar)
Hydrochloric acid (0.15 molar) will be infused in to the lower oesophagus through a distal infusion port located at the tip of an oesophageal stimulation catheter.
|Placebo Comparator: Saline||
Normal saline will be infused in to the lower oesophagus through a distal infusion port located at the tip of an oesophageal stimulation catheter.
|University Hospital of South Manchester|
|Manchester, United Kingdom, M23 9LT|
|Principal Investigator:||Ashley Woodcock, Prof||the University of Manchester|