The Efficacy of Motor Cortex Stimulation for Pain Control

Study Overview
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Brief Summary
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The objective is to determine if motor cortex stimulation works for the following conditions: Deafferentation facial pain, Upper extremity complex regional pain syndrome (CRPS) and Brachial plexus avulsion or phantom limb pain. Each of these groups of 6 patients (total of 18) will be studied independently and all patients will be implanted with a motor cortex stimulation system. They will be randomised to either a regular or low stimulation setting in the two arms of the study. Each arm will last 3 months.

Detailed Description
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This is a prospective, blinded randomized crossover study comparing two stimulation paradigms in three different groups of patients receiving motor cortex stimulation. The aim of this study is to examine the effectiveness of this modality in a controlled blinded manner, which has not been done in previous studies. There are two primary purposes of this study. The first is to compare two different stimulation paradigms: high level stimulation (i.e. stimulator activated 'on' for 10 minutes, 'off' for 2 hours; presumed therapeutic dose); versus low stimulation ('on' for 1 minute, 'off' for 6 hours; presumed subtherapeutic dose), in a prospective blinded crossover study design. The second purpose of this study, is to examine the outcome of MCS in three different pain groups. These are: Unilateral upper extremity neuropathic pain such as brachial plexus avulsion, stump pain or phantom limb pain Neuropathic deafferentation facial pain Upper extremity complex regional pain syndrome (CRPS) Measurements of the effects of motor cortex stimulation will include a visual analogue scale (VAS) of perceived pain, the McGill Pain Questionnaire, SF-36 quality of life questionnaire, Beck Depression Inventory-II, the standard 7-point patient global impression of change (PGIC), medications log (verified by pharmacy records) and an employment status questionnaire. Adverse events will be recorded at each visit. Table 1: Visit Study Week Standard Care 0a 1b 12c 24d 1a 2e 3f 4g F/Uh Clinic Visit X X X X X X Consent X Surgery X X X Program MCS X X X X X X VAS X X X X X X X SF-36 X X X X X X X Medications Log X X X X Employment Status X X X X McGill Pain X X X X X X X Beck Depression II X X X X Global impression of change X X Screening visit in consideration of MCS Immediate post-op visit, randomization to high or low settings 12 week crossover point Final study visit, MCS programmed at 'best' settings Trial period of MCS, lasting for 1 to 2 weeks Clinic visit to determine efficacy of MCS and removal of temporary external system. Permanent implantation of MCS, if trial was successful Follow-up as required.

Official Title
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The Efficacy of Motor Cortex Stimulation for Pain Control

Conditions
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Neuropathic Pain, Phantom Limb Pain, Stump Pain, Brachial Plexus Avulsion, Deafferentation Pain, Facial Pain, Complex Regional Pain Syndrome

Intervention / Treatment
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* Device: motor cortex stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diagnosis in one of the following three categories: Unilateral upper extremity neuropathic pain such as phantom limb pain, stump pain or brachial plexus avulsion Neuropathic deafferentation facial pain Upper extremity complex regional pain syndrome (CRPS) Pain is refractory to conservative methods (e.g. medications, regional blocks) as reviewed by a chronic pain clinical physician Patient is considered a good candidate for neurosurgery, i.e. no other medical problems that would preclude surgery Patients who are willing to provide informed consent. Exclusion Criteria: Patients who are not considered medically fit for neurosurgery. Patients who have not exhausted conservative methods of pain control, prior to considering motor cortex stimulation. Patients who are not able to provide informed consent. Patients unable to have magnetic resonance imaging (MRI).
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Intervention/Treatment |
| --- |
|Device: motor cortex stimulation|nan|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Visual Analog scale |  | 1 month preop, at 12 and 24 weeks postop | 
| SF-36 |  | 1 month preop, at 12 and 24 weeks postop | 
| McGill Pain questionnaire |  | 1 month preop, at 12 and 24 weeks postop | 
| Beck II depression |  | 1 month preop, at 12 and 24 weeks postop | 
| Global impression of change |  | at 12 and 24 weeks postop | 
| Medications log |  | 1 month preop, at 12 and 24 weeks postop | 
| Employment status |  | 1 month preop, at 12 and 24 weeks postop | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Motor cortex stimulation, neuropathic, pain, complex regional pain syndrome, deafferentation facial pain