Reference Values and Clinical Screening Test of Diffuse Noxious Inhibitory Controls (DNIC)

Active, not recruiting

• Conditions: Chronic Pain
• Interventions: Other: Conditioned pain modulation

• Registration Number: NCT03376867
• Lead Sponsor: Université de Sherbrooke

Brief Summary

Chronic pain (CP) is disabling for people triggering important costs for society. A deficit of diffuse noxious inhibitory controls (DNIC) is one of the CP mechanisms. DNICs are evaluated in research setting using a CPM protocol (conditioned pain modulation). There is a lack of reference values on the effectiveness of DNICs. Wider research on DNIC will help to understand CP and to develop a clinical screening test evaluating DNICs.

Detailed Description

This study aims:

1. To establish baseline values of DNICs using CPM protocol

2. To identify the variables that will be integrated in the algorithm of the clinical screening test (clinical decision rule).

First the target population will be healthy volunteers, male and female, stratified by age. The reference values will be established via a non-parametric method for a standard CPM protocol in which two different pain stimuli are applied. Two "stimuli tests" of the same intensity and nature (heat) will be applied before and after the application of another "conditioning stimulus" (cold water bath). The perceived pain difference between the 1st and 2nd stimuli tests will reflect the intensity of the DNICs.

Secondly, these results will be compared to those from volunteers suffering of chronic pain. The clinical decision rule will result from clinical and paraclinical elements correlating with the amplitude of the efficacy of CPM (serum noradrenaline, intensity of pain, heart rate and blood pressure measurements, psychometric questionnaires assessing anxiety, depressive feelings and pain catastrophizing). Logistic regression analysis will determine the best predictors of a CPM deficit.

Study Timeline

• Study Start: 2017-11-27
• Study First Submitted: 2017-12-07
• Study First Submitted QC: 2017-12-12
• Study First Posted: 2017-12-19
• Primary Completion: 2022-02-28
• Status Verified: 2024-02
• Last Update Submitted: 2024-02-13
• Last Update Posted: 2024-02-15
• Study Completion: 2024-12-30

Recruitment & Eligibility

• Status: ACTIVE_NOT_RECRUITING
• Sex: All
• Target Recruitment: 468

Inclusion Criteria

• 18-79 years old
• Able to provide consent

Exclusion Criteria

• cardiovascular disease (arrhythmia, cerebrovascular accident, infarction...)
• Raynaud syndrome
• severe psychiatric disease (dementia, schizophrenia, psychosis, major depression)
• injuries or loss sensitivity to their forearms or hands
• pregnant women or in post-partum period (<1 year)

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Healthy volunteers	Conditioned pain modulation	Conditioned pain modulation (2 stimuli test: heat and pressure points) before and after conditioning stimuli (cold water bath).
Volunteers with chronic pain	Conditioned pain modulation	Conditioned pain modulation (2 stimuli test: heat and pressure points) before and after conditioning stimuli (cold water bath).

Primary Outcome Measures

Name	Time	Method
Conditioned pain modulation	Once, at baseline, at recruitment (comparison between 1st and 2nd test, after the conditioning stimuli)	Alteration (reduction or augmentation) of pain sensitivity after activation of endogenous pain-inhibitory system, measured by computerized visual analog scale (CoVAS) ranging from 0 \[no pain\] to 100 \[most intense pain that could be tolerated\]

Secondary Outcome Measures

Name	Time	Method
pressure points threshold	Twice, at baseline, at recruitment (before and after the conditioning stimuli)	On both trapezius muscles

Trial Locations

Locations (1)

Universite de Sherbrooke; 🇨🇦 Sherbrooke, Quebec, Canada