Central Sensitization in Chronic Whiplash Patients

Study Overview
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Brief Summary
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The purpose of this study is to determine whether the metabolite concentrations within the anterior cingulate cortex and periaqueductal gray matter predict the intensity and interference of neuropathic pain after the development of chronic whiplash syndrome.

Detailed Description
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Persistent chronic pain is a common symptom of whiplash leading to reduced quality of life. Little information is available regarding changes in brain processing areas and change in central sensitization to noxious input during the chronic phase of whiplash. Metabolite concentrations in the anterior cingulate cortex and periaqueductal gray matter may be predictors of neuropathic pain and these changes may explain the development of central sensitization in people with chronic whiplash. Until now, there is not any study that show this approach.

Official Title
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Central Sensitization in Chronic Whiplash Patients: Metabolite Concentrations in the Anterior Cingulate Cortex and Periacueductal Gray Matter

Conditions
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Chronic Pain

Intervention / Treatment
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* Radiation: Spectroscopy
* Other: Questionnaires
* Procedure: Conditioned Pain Modulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Whiplash syndrome Chronic pain Age between 18 to 65 years 4 months to 2 years after the whiplash syndrome Exclusion Criteria: Neurological disease Claustrophobia

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Whiplash-Pain<br>Subjects with chronic whiplash syndrome and pain. The inclusion criteria for pain include the presence of daily pain during the previous 8 weeks. Specifically, pain will be diagnosed based on the pain intensity measured on the 0 to 10 numerical rating scale. The minimum will be 2 points. Subjects will be recruited between the 4 months until 2 years after the whiplash. | Radiation: Spectroscopy<br>* Spectroscopy is a noninvasive method to assess brain chemistry. The signal of the hydrogen atom attached to a certain molecule or metabolite has a particular frequency associated with a given metabolite. The utility of Spectroscopy is based on the fact thet the nuclei of atoms have magnetic properties that can be used to obtain chemical information regarding both the type of molecule and it is concentration. The subjects will be scanned on a 3-T Siemens system and an 12-channel phased-array coil will be used to provide an optimum signal-to-noise ratio for spectroscopy data.<br>Other: Questionnaires<br>* Questionnaires are important to assess the chronic pain and their impact in the quality of life. For this reason, we will assess the Brief Pain Inventory (BPI), it is used to evaluate the subject's perception of pain severity and its interference. Moreover, we will assess neuropathic pain symptoms with the NPSI to detect paresthesia/dysaesthesia, evoked pain and paroxysmal pain. The catastrophizing score will be measured with the Pain Catastrophizing Helplessness Subscale. Also,we will assess the disability after whiplash using the Neck Disability Index.<br>Procedure: Conditioned Pain Modulation<br>* Conditioned Pain Modulation over the tenar eminence. The test will be a heat tonic stimulus which evoke a 3-pain intensity. The conditioning stimulus will be a cold water immersion (12ºC)<br>|
| Whiplash-no Pain<br>Subjects with chronic whiplash syndrome and pain. The inclusion criteria for pain include the ausence of daily pain during the previous 8 weeks. Specifically, pain will be diagnosed based on the pain intensity measured on the 0 to 10 numerical rating scale. The maximun will be 2 points. Subjects will be recruited between the 4 months until 2 years after the whiplash. | Radiation: Spectroscopy<br>* Spectroscopy is a noninvasive method to assess brain chemistry. The signal of the hydrogen atom attached to a certain molecule or metabolite has a particular frequency associated with a given metabolite. The utility of Spectroscopy is based on the fact thet the nuclei of atoms have magnetic properties that can be used to obtain chemical information regarding both the type of molecule and it is concentration. The subjects will be scanned on a 3-T Siemens system and an 12-channel phased-array coil will be used to provide an optimum signal-to-noise ratio for spectroscopy data.<br>Other: Questionnaires<br>* Questionnaires are important to assess the chronic pain and their impact in the quality of life. For this reason, we will assess the Brief Pain Inventory (BPI), it is used to evaluate the subject's perception of pain severity and its interference. Moreover, we will assess neuropathic pain symptoms with the NPSI to detect paresthesia/dysaesthesia, evoked pain and paroxysmal pain. The catastrophizing score will be measured with the Pain Catastrophizing Helplessness Subscale. Also,we will assess the disability after whiplash using the Neck Disability Index.<br>Procedure: Conditioned Pain Modulation<br>* Conditioned Pain Modulation over the tenar eminence. The test will be a heat tonic stimulus which evoke a 3-pain intensity. The conditioning stimulus will be a cold water immersion (12ºC)<br>|
| Non-injured<br>Subjects without whiplash syndrome. The inclusion criteria are defined as a absence of previous or actual symptoms or signs of neck pain. | Radiation: Spectroscopy<br>* Spectroscopy is a noninvasive method to assess brain chemistry. The signal of the hydrogen atom attached to a certain molecule or metabolite has a particular frequency associated with a given metabolite. The utility of Spectroscopy is based on the fact thet the nuclei of atoms have magnetic properties that can be used to obtain chemical information regarding both the type of molecule and it is concentration. The subjects will be scanned on a 3-T Siemens system and an 12-channel phased-array coil will be used to provide an optimum signal-to-noise ratio for spectroscopy data.<br>Other: Questionnaires<br>* Questionnaires are important to assess the chronic pain and their impact in the quality of life. For this reason, we will assess the Brief Pain Inventory (BPI), it is used to evaluate the subject's perception of pain severity and its interference. Moreover, we will assess neuropathic pain symptoms with the NPSI to detect paresthesia/dysaesthesia, evoked pain and paroxysmal pain. The catastrophizing score will be measured with the Pain Catastrophizing Helplessness Subscale. Also,we will assess the disability after whiplash using the Neck Disability Index.<br>Procedure: Conditioned Pain Modulation<br>* Conditioned Pain Modulation over the tenar eminence. The test will be a heat tonic stimulus which evoke a 3-pain intensity. The conditioning stimulus will be a cold water immersion (12ºC)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Metabolite concentrations | The metabolite concentrations will be measured by magnetic resonance (spectroscopy) | Baseline at 0 min | 
| Conditioned Pain Modulation | Conditioned Pain Modulation will be measured by a Pathway system (Medoc Ltd) | Baseline at 0 min | 
| Brief Pain Inventory | Brief Pain Inventory (BPI), it is used to evaluate the subject's perception of pain severity and its interference. | Baseline at 0 min | 
| Neurophatic Pain Symptoms Inventory | Neurophatic Pain Symptoms Inventory (NPSI), it is used to detect paresthesia/dysaesthesia, evoked pain and paroxysmal pain. | Baseline at 0 min | 
| Pain Catastrophizing Helplessness Subscale | Pain Catastrophizing Helplessness Subscale it is used to assess the catastrophizing score | Baseline at 0 min | 
| Neck Disability Index | Neck Disability Index (NDI), it is used to assess the disability after whiplash syndrome | Baseline at 0 min | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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metabolite, central sensitization, whiplash