Conditioned Pain Modulation in Chronic Neck Pain Patients

Study Overview
=================
Brief Summary
-----------------
The aim of this study was to evaluate changes in local and segmental hypersensitivity and endogenous pain inhibition in people with chronic nonspecific neck pain.

Detailed Description
-----------------
Quantitative sensory testing is widely used in human research to investigate the state of the peripheral and central nervous system contributions in pain processing. It is a valuable tool to help identify central sensitization and may be important in the treatment of chronic neck pain. This study is a cross-sectional study. Two groups including chronic neck pain group and healthy volunteers group will be arranged in this study. The healthy subjects will be matched for sex and age in relation to the neck pain group. The pressure pain threshold (PPT) will be measured at the neck muscle in both groups. The cold pressor test will be used in both groups to activate conditioned pain modulation.

Official Title
-----------------
The Hypersensitivity and Changes of Conditioned Pain Modulation in Chronic Neck Pain Patients

Conditions
-----------------
Neck Pain

Intervention / Treatment
-----------------
* Other: Patients with chronic neck pain
* Other: Subjects without chronic neck pain


Participation Criteria
=================
Eligibility Criteria
-----------------
Chronic neck pain subjects Inclusion criteria: Age 21-80 years old. People must have experienced neck pain for at least 3 months and have reported a minimal pain level of 30 (pain threshold) on the 0-100 pain numerical rating scale (NRS) in the last 7 days. Exclusion Criteria: Age under 21 or over 80. Patients were excluded if they had taken pain medications on the day of the assessment or if they had serious spinal pathologies, such as fractures, tumors or inflammatory diseases, such as ankylosing spondylitis, nerve root compromise confirmed by clinical neurological tests or severe cardiorespiratory diseases. Those who were pregnant, patients with cancer and those with a cardiac pacemaker were also excluded. Healthy volunteers Inclusion criteria: Age 21-80 years old. These participants must not have presented episodes of low back pain for more than 7 days in the last 12 months. Exclusion Criteria: Age below 21 or over 80 years old. These participants have presented episodes of low back pain for more than 7 days in the last 12 months.

Ages Eligible for Study
-----------------
Minimum Age: 21 Years
Maximum Age: 80 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients with chronic neck pain<br>Patients,aged 21-80 years, must have experienced neck pain for at least 3 months and have reported a minimal pain level of 30 (pain threshold) on the 0-100 pain numerical rating scale (NRS) in the last 7 days. | Other: Patients with chronic neck pain<br>* Patients,aged 21-80 years, must have experienced neck pain for at least 3 months and have reported a minimal pain level of 30 (pain threshold) on the 0-100 pain numerical rating scale (NRS) in the last 7 days.<br>|
| Subjects without chronic neck pain<br>Subjects,aged 21-80 years, must not have presented episodes of chronic neck pain for more than 7 days in the last 12 months. | Other: Subjects without chronic neck pain<br>* Subjects,aged 21-80 years, must not have presented episodes of chronic neck pain for more than 7 days in the last 12 months.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of pressure pain threshold (PPT) | A cold pressor test (CPT) was used to induce pain and trigger the conditioned pain modulation (CPM) response. The conditioned stimulus was immersion of the leg in a bucket of ice water on the side ipsilateral to the most painful neck region. The neck PPT was recorded beginning 30 s after immersion of the leg with two PPT measures for each point. The PPT will be also measured again immediately after CPT. | The PPT will be measured before CPT, 30 seconds after the CPT begin, and immediately after CPT. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Numerical rating scale for pain (NRS) | The NRS evaluates levels of pain intensity using an 100-point scale (range 0-100), with 0 being classified as no sensation, 30 pain threshold, 100 pain as bad as could be. | The patients used this scale to rate the pain intensity of the neck pain before the experiment. | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Conditioned pain modulation, neck pain