Evoked Fields After Median and Ulnar Stimulation

Study Overview
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Brief Summary
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In order to be able to study the effects of evoked fields with magnetoencephalography (MEG) in two groups of patients, comparison is made with a group of healthy volunteers.

Detailed Description
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This study is directed at the (central and / or peripheral) mechanisms of pain and the cortical changes (plasticity) due to chronic non-malignant pain in two groups of patients and one healthy volunteer group. The aim of the study is further to evaluate cortical processes by MEG (and fMRI, if feasible) to quantify and qualify the responses, localise the generators and study the effects of a pain therapy. To search for patterns that may result in diagnostic criteria and have an indicative value for the treatment and the monitoring of the effects. Finally the study not only intends to support clinical diagnosis but also to provide tools to monitor treatment and support the choice (algorithm) between SCS and SAN. An algorithm, facilitating decision making between these two treatments, will be promoted. It should also provide a clinical decision tool for the use of SAN

Official Title
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Evoked (Magnetic) Cortical Fields for the Comparative Study of Mechanisms Underlying Chronic Non-malignant Pain in Peripheral Nerve Injury (CRPS II) and CRPS I (Chronic Regional Pain Syndrome I)

Conditions
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Complex Regional Pain Syndromes

Intervention / Treatment
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* Other: Evoked fields before and after a local block (Xylocaine)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: CRPS I: (Absolute) functio laesa, secondary pain and cold sensations (Relative) abnormal skin colour, allodynia, hyperalgesia, hyperpathia, hyperhydrosis,oedema, increased nail growth, increased hair growth. (At least 4 need to be present). CRPS II: All the previous but evidence of traumatic peripheral nerve injury. Exclusion Criteria: General condition Pregnancy Technical implants (pacemaker, SCS: disturbs MEG)

Ages Eligible for Study
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Minimum Age: 17 Years
Maximum Age: 70 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 |
| --- | --- |
| Pain study Netherlands<br>20 healthy subjects 20 patients with a traumatic unilateral peripheral nerve injury 20 patients with CRPS I | Other: Evoked fields before and after a local block (Xylocaine)<br>* MEG registration after electrical median and ulnar nerve stimulation in subjects and patients. In the patient group another MEG was performed after an anaesthetic block (1-2 ml Lidocaine 1%) at the site of the nerve injury producing a painfree state<br>* Other names: All patients with CRPS I were rated with the C - code, 1 to 20;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Pain, Magnetoencephalography, Median, Ulnar, Causalgia, Complex regional pain syndrome, Evoked fields, Nerve injury, Neuropathic pain