Spinal Cord Stimulation (SCS) Dosing Study

Study Overview
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Brief Summary
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This study characterized the effects of amplitude on subject satisfaction and pain relief in subjects being treated by SCS.

Detailed Description
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This feasibility study assessed the following outcomes: Patient satisfaction VAS pain scores

Official Title
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Spinal Cord Stimulation (SCS) Dosing Study

Conditions
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Back Pain, Leg Pain

Intervention / Treatment
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* Device: Spinal Cord Stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 22 years of age or older Implanted with a RestoreSensor system (for back and leg pain) for at least 1 month Has approproate SCS settings Willing and able to provide signed and dated informed consent Capable of comprehending and consenting in English Capable of getting into the supine and sitting positions Willing and able to comply with all study procedures and visits On stable (no change in dose, route, or frequency) prescribed pain medications Exclusion Criteria: Implanted with leads for peripheral nerve stimulation or an implantable intrathecal drug delivery system Had a pain-related surgery in the previous 1 month of enrollment or the intent to undergo surgery during the period of the study Implanted with quadripolar lead Currently enrolled or planning to enroll in a potentially confounding clinical study during the course of the study Pregnant or is of child-bearing potential and unwilling to use a medically acceptable form of birth control during the study Has untreated major psychiatric comorbidity Has serious drug-related behavioral issues Has unresolved major issues of secondary gain

Ages Eligible for Study
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Minimum Age: 22 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
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Spinal Cord Stimulation<br>Each subject was programmed to 4 different amplitude settings: 80%, 60%, 40% and 20% of perception threshold amplitude | Device: Spinal Cord Stimulation<br>* Programming<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| SCS Therapy Satisfaction | To characterize the effect of four different amplitude settings on baseline SCS therapy satisfaction. At each follow-up visit, the following question was asked to measure satisfaction: Overall how satisfied or unsatisfied are you with this therapy?. The response choices were as follows: very satisfied, somewhat satisfied, neutral, somewhat unsatisfied, very unsatisfied. Each subject was considered to have maintained their baseline SCS therapy satisfaction if they selected the response very satisfied, somewhat satisfied, or neutral, otherwise they were considered dissatisfied with the therapy. The first visit in which each subject reported dissatisfaction of the therapy was recorded. The amplitude used during the prior visit was then considered to be the minimum amplitude that maintained each subject's therapy satisfaction. The frequency and percentage of subjects' that maintained baseline satisfaction were reported at each amplitude level. | 8 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants Maintaining Baseline Pain as Measured on the Visual Analog Scale (VAS) | To characterize the effect of four different amplitude settings on baseline pain relief. During each follow-up period the VAS pain score was recorded once a day, on a multi-day diary, where subjects rated their pain by making a vertical slash mark through the 0-10 cm line that best described their pain during the last 24 hours, with 0 = No pain and 10 = Worst pain imaginable. The higher VAS pain score represented worse pain. The average VAS pain scores from the last 3 days of the diary prior to the scheduled visit was used for analysis. Each subject was considered to have maintained their baseline pain if there was less than a 2 point increase in their average pain score at the follow-up period. The amplitude used during the prior visit was then considered to be the minimum amplitude that maintained the subject's pain relief. The frequency and percentage of subjects' that maintained their average baseline VAS pain score were reported at each amplitude level. | 8 weeks |