Motor Cortex Stimulation for Chronic Neuropathic Pain

Study Overview
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Brief Summary
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The purpose of this study is to evaluate the efficacy of cortical stimulation (CS) as an adjunctive treatment for chronic neuropathic pain.

Detailed Description
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Prospective, controlled, double blind, randomized, crossover study with endpoint evaluations at the end of each 3-month treatment period. An interim analysis will be conducted by a blinded committee when approximately half of the patients have finished the study.

Official Title
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A Clinical Evaluation for the Management of Patients With Chronic Neuropathic Pain With Cortical Stimulation

Conditions
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Neuropathic Pain, Facial Pain, Post-stroke Pain, Brachial Plexus Avulsion, Phantom Limb Pain of the Upper Extremities

Intervention / Treatment
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* Device: Motor Cortex Stimulation using SJM EonC Stimulator


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Men and women (non-pregnant) age 21-70 years; Able to give informed consent in accordance with institutional policies; Diagnosis of chronic neuropathic pain according to the DN4 Neuropathic Pain Diagnosis scale (score ≥ 4). Documented pain for at least 12 months; Documented previous or current treatment for neuropathic pain with medications from at least two of the following groups at adequate doses: antidepressants, anticonvulsants, and/or gabapentinoids; VAS scores of at least 6 during baselines #1 and 2. Documented clinical diagnosis of neuropathic pain associated with one of the following conditions: facial pain, post-stroke pain, brachial plexus avulsion, or phantom limb pain of the upper extremities. In the group with post-stroke pain, only patients with predominant face and upper extremity pain will be included. This will be defined as a difference of ≥ 30% or ≥ 2 points in VAS scores between these regions and lower extremity (in patients who also have pain in the leg). No change in current neuropathic pain medication regimen for at least 4 weeks prior to study enrollment. Able to comply with all testing and follow-up requirements as defined by the study protocol. Must be determined medically stable by surgeon to undergo cortical stimulation surgical procedure. Exclusion Criteria: Alcohol, medication, or illegal substance dependence or abuse within last 12 months; Trigeminal neuralgia or atypical facial pain. Post-stroke pain predominantly in the lower extremity. Advanced cardiovascular disease which renders anesthesia and surgery as unsafe as determined by neurosurgeon; Clinically relevant abnormality (e.g. tumor) on study MRI; Has cardiac pacemaker/defibrillator or other implanted active stimulator; Has a medical condition requiring a repetitive MRI body scan; Requires chemotherapy for the treatment of malignancy or requiring chronic oral or intravenous, immunosuppressive, or steroid therapy; Is unable to comply with study visit schedule and timeline; Past ablative or relevant intracranial surgery; A female lactating or of child bearing potential, with a positive pregnancy test or not using adequate contraception; Other medical conditions likely to require hospitalization within the next year.

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 70 Years

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: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Active stimulation<br> | Device: Motor Cortex Stimulation using SJM EonC Stimulator<br>* Patients will be randomized to receive either active stimulation the first 3 months followed by a one-month washout, followed by Sham Stimulation the next 3 months, vs. the reverse order of treatment, followed by single blind stimulation, and an open label phase.<br>|
| Sham Comparator: Sham stimulation<br> | Device: Motor Cortex Stimulation using SJM EonC Stimulator<br>* Patients will be randomized to receive either active stimulation the first 3 months followed by a one-month washout, followed by Sham Stimulation the next 3 months, vs. the reverse order of treatment, followed by single blind stimulation, and an open label phase.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Visual Analog Scale (VAS) | The primary analysis of effectiveness is based on the mean differences in changes from the period-specific baseline in VAS scores when patients are receiving 3 month of active vs. 3 months of sham stimulation on a double-blinded fashion. | Approximately 7 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Visual Analog Scale, responder | defined as a ≥30% or 2 points reduction from baseline in VAS scores | Participants will be followed for approximatley 18 months | 
| Neuropathic Pain Symptom Inventory (NPSI) |  | Participants will be followed for approximatley 18 months | 
| Brief Pain Inventory (BPI) |  | Participants will be followed for approximatley 18 months | 
| Short Form of the McGill Pain Questionnaire(SF-MPQ) |  | Participants will be followed for approximatley 18 months | 
| Sickness Impact Profile (SIP) |  | Participants will be followed for approximatley 18 months | 
| Medication Quantification Scale (MQS) |  | Participants will be followed for approximatley 18 months | 
| SF-36 Health Survey and safety |  | Participants will be followed for approximatley 18 months | 
| Pain Catastrophizing Scale (PCS) |  | Participants will be followed for approximatley 18 months | 
| Global Impression of Change (patient and evaluator's version) |  | Participants will be followed for approximatley 18 months | 
| Device related Adverse Events |  | Participants will be followed for approximatley 18 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Motor Cortex Stimulation, Neuropathic pain