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

Université de Sherbrooke

Status: Active, not recruiting

Conditions: Chronic Pain

Treatments: Other: Conditioned pain modulation

Study type: Observational

Funder types: Other

Identifiers

NCT03376867

2018-2422

Details and patient eligibility

About

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.

Full 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.

Enrollment: 468 estimated patients

Sex: All

Ages: 18 to 79 years old

Volunteers: Accepts Healthy Volunteers

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)

Trial design

468 participants in 2 patient groups

Healthy volunteers

Description:

Conditioned pain modulation (2 stimuli test: heat and pressure points) before and after conditioning stimuli (cold water bath).

Treatment:

Other: Conditioned pain modulation

Volunteers with chronic pain

Description:

Conditioned pain modulation (2 stimuli test: heat and pressure points) before and after conditioning stimuli (cold water bath).

Treatment:

Other: Conditioned pain modulation