Burst Spinal Cord Stimulation for Neuropathic Pain.

Study Overview
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Brief Summary
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This study will evaluate the effect of Burst spinal cord stimulation (SCS) in the treatment of painful radiculopathy in lower extremity(ies) with or without lower back pain. It is a multicenter double-blinded n-of-1 RCT with repeated two-week periods of Burst SCS or sham in randomised order.

Detailed Description
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SCS is a treatment offered to patients with peripheral neuropathic pain, and involves electrical stimulation of the spinal cord. The analgesic effect is possibly mediated via both spinal and supra-spinal mechanisms. Traditional tonic SCS causes paresthesia during treatment, but the newer burst technique (five electrical pulses at 500Hz delivered in intermittent packets of 40 Hz) can be performed below detection level. Thus, it is possible to do double-blinded sham-controlled studies. In this study, we will study the effect of burst SCS compared with sham on pain intensity and function (Patient-Specific Functional Scale). In addition, we will use several questionnaires (psychometric data, health-related quality of life, sleep, global impression of change, use of analgesics, blinding).

Official Title
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A Randomised Sham-controlled Double-blinded Study of Burst Spinal Cord Stimulation for Chronic Peripheral Neuropathic Pain.

Conditions
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Peripheral Neuropathic Pain, Radiculopathy, Lower Back Pain

Intervention / Treatment
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* Device: Burst SCS (Abbott Proclaim IPG and single lead Abbott Octrode at level Th9/10)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: History, symptoms and clinical findings consistent with painful radiculopathy in lower extremity(ies) (probable or definite) for at least 3 months, with or without lower back pain. The pain in the extremity(ies) must dominate. Understand Norwegian or Swedish language (written and spoken). Usual pain intensity ≥ 3.5 / 10 (NRS 0-10) Exclusion Criteria: Absolute Opioid dose > 100 mg morphine equivalents / day Ongoing litigation Mental / psychiatric disorder that may affect treatment Chronic generalized pain Pregnancy Hypersensitivity to local anesthetics Serious or unclear medical condition such as angina pectoris, severe vascular disorder, infection, malignancy disease, bleeding disorders Laminectomy in or above level for planned epidural access Spine surgery the last 3 months Relative Ongoing medication that affects coagulation or platelet function

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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
Interventional Model Description: N-of-1-study. Each patient will go through three treatment cycles each consisting of two weeks of active treatment and two weeks of sham in randomised order. In total the study period will be 12 weeks.
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Burst SCS<br>In the active comparator the burst SCS system will be turned on according to randomisation. A treatment period is a 2-week period where the patient receives either active treatment or sham. Each patient will go through 6 treatment periods (in total 12 weeks). A treatment cycle is a 4-week period with two treatment periods, one of active treatment and one of sham. Each patient will go through three treatment cycles. | Device: Burst SCS (Abbott Proclaim IPG and single lead Abbott Octrode at level Th9/10)<br>* Burst SCS implies high frequency SCS treatment in intermittent packets with stimulation below detection level. Abbott BurstDR at default setting: Pulse width 1000 microseconds, frequency 500 Hz/40 Hz, continuous stimulation (no cycling). Pulse amplitude at maximum 60% of sensory threshold<br>|
| Sham Comparator: Sham<br>In the sham comparator the burst SCS system will be turned off according to randomisation. | Device: Burst SCS (Abbott Proclaim IPG and single lead Abbott Octrode at level Th9/10)<br>* Burst SCS implies high frequency SCS treatment in intermittent packets with stimulation below detection level. Abbott BurstDR at default setting: Pulse width 1000 microseconds, frequency 500 Hz/40 Hz, continuous stimulation (no cycling). Pulse amplitude at maximum 60% of sensory threshold<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Usual pain intensity in lower extremity(ies) | Numeric rating scale (0-10); usual pain intensity over the last 24 h (day 7-13) with anchor points 0 = No pain and 10 = Worst imaginable pain. | Will be measured at day 7 to day 13 in each period (to avoid carry-over effects from previous treatment period) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Highest pain intensity in lower extremity(ies) | Numeric rating scale (0-10); highest pain intensity over the last 24 h (day 7-13) with anchor points 0 = No pain and 10 = Worst imaginable pain | Will be measured at day 7 to day 13 in each period (to avoid carry-over effects from previous treatment period) | 
| Lowest pain intensity in lower extremity(ies) | Numeric rating scale (0-10); lowest pain intensity over the last 24 h (day 7-13) with anchor points 0 = No pain and 10 = Worst imaginable pain | Time Frame: Will be measured at day 7 to day 13 in each period (to avoid carry-over effects from previous treatment period) | 
| Pain intensity in lower extremity(ies)now | Numeric rating scale (0-10); evening pain intensity (day 7-13), with anchor points 0 = No pain and 10 = Worst imaginable pain | Time Frame: Will be measured at day 7 to day 13 in each period (to avoid carry-over effects from previous treatment period) | 
| Pain unpleasantness | Numeric rating scale (0-10) of pain unpleasantness the last 24 hours, with anchor points 0 = no unpleasantness to 10 = worst imaginable unpleasantness. | Time Frame: Will be measured at day 7 to day 13 in each period (to avoid carry-over effects from previous treatment period) | 
| Three individually chosen functions that are inhibited by the pain | The Patient-Specific Functional Scale (Numeric Rating Scale (0-10)) (day 7-13). Anchor points 0 = Unable to perform activity to 10 = Able to perform activity. | Time Frame: Will be measured at day 7 to day 13 in each 14-day treatment period (to avoid carry-over effects from previous treatment period) | 
| Insomnia | Insomnia Severity Index questionnaire. (Likert scale: 0= no problem, 4 = very severe problem, total score up to 28. Total score (continuous variable) | Time Frame: Will be measured at the end of each 14-day treatment period | 
| EQ-5D index values | EQ5D index values according to the EQ-5D UK Time Trade-off (TTO) value set. | Time Frame: Will be measured at the end of each 14-day treatment period | 
| EQ-5D self-rated health | VAS 0-100 scale. | Time Frame: Will be measured at the end of each 14-day treatment period | 
| Patient impression of change | Patient Global Impression of Change questionnaire. Patient's global impression of change (function, symptoms and quality of life) since last control (about 14 days prior): Very much improved, much improved, minimally improved, no change, minimally worse, much worse, very much worse. | Time Frame: Will be measured at the end of each 14-day treatment period | 
| Patient blinding questionnaire | Does the patient think that the system has been turned on or off | Time Frame: Will be measured at the end of each 14-day treatment period | 
| Synptoms of anxiety and depression | Hopkins Symptom Checklist-25. Likert scale, from 1(Not at all) to 4 (Extremely), mean of sumscore, 25 in total. Change in totalscore (Continious variable). | Time Frame: Will be measured at the end of each 14-day treatment period | 
| Usual pain intensity in lower back | Numeric rating scale (0-10); usual pain intensity over the last 24 h (day 7-13) with anchor points 0 = No pain and 10 = Worst imaginable pain. | Will be measured at day 7 to day 13 in each period (to avoid carry-over effects from previous treatment period) |