Failed Back Surgery Syndrome
Conditions
Brief summary
The purpose of this study is to evaluate the role of frequency settings on spinal cord stimulation in the management of Failed Back Surgery Syndrome (SCS Frequency Study).
Detailed description
Prospective, single-center, double-blinded, randomized crossover of 4 different stimulation frequencies: sham, 1200 Hz, 3030 Hz, and 5882 Hz.
Interventions
DEVICESham
Frequency Setting - Sham
DEVICE1200 Hz
Frequency Setting - 1200 Hz
DEVICE3030 Hz
Frequency Setting - 3030 Hz
DEVICE5882 Hz
Frequency Setting - 5882 Hz
Sponsors
MedtronicNeuro
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* At least 18 years old at the time of informed consent * Willing and able to provide a signed and dated informed consent * Capable of comprehending and consenting in English * Willing and able to comply with all study procedures, study visits, and be available for the duration of the study * On a stable dose (no new, discontinued or changes in) of all prescribed pain medications and willing/able to maintain or only decrease the dose of all prescribed pain medications * Tried appropriate conventional medical management for their pain * Not indicated for additional surgical treatment in the opinion of the referring physician or spinal surgeon * Undergone previous spinal surgery * Diagnosed with FBSS with appropriate pain score * Primary pain at appropriate spinal level
Exclusion criteria
* Has an active implanted device, whether turned on or off * Displays current signs of a systemic infection * Pregnant or lactating, inadequate birth control, or the possibility of pregnancy during the study * Has untreated major psychiatric comorbidity * Has serious drug-related behavioral issues * Has neurological abnormalities unrelated to Failed Back Surgery Syndrome * Diagnosed with Raynaud disease * Diagnosed with Fibromyalgia * Has any active malignancy or has been diagnosed with cancer and has not been in remission for at least 1 year prior to screening * Has secondary gains which, in the opinion of the investigator, are likely to interfere with the study * Participating or planning to participate in another clinical trial * Has characteristics/limits of household or close contacts involved in study (eg, family member already a study participant where blind could be broken)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Visual Analog Scale (VAS) on Back Pain | 12 weeks | Visual Analog Scale (VAS) back pain scores were recorded once a day on a multi-day diary, where subjects rate the pain by making a vertical slash mark through the 0-10cm line that best describes their pain during the last 24 hours, with 0 = No pain and 10 = Worst pain imaginable. The higher VAS back pain score represented worse back pain. The average VAS back pain scores from the last three days of diary prior to the follow-up visits were used for analysis. |
Countries
United Kingdom
Participant flow
Recruitment details
A total of 53 subjects were recruited between January 2013 and April 2015.
Pre-assignment details
A total of 23 subjects discontinued prior to randomization due to eligibility criteria not met or withdrawal from the study.
Participants by arm
| Arm | Count |
|---|---|
| Randomized Phase Subjects Randomized phase subjects received all four frequency settings (Sham, 1200 Hz, 3030 Hz, and 5882 Hz), each for 3 weeks, in a randomized order. | 24 |
| Total | 24 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Long-term Follow-up Phase | Adverse Event | 2 |
| Long-term Follow-up Phase | Withdrawal by Subject | 1 |
| Randomized Crossover Phase | Adverse Event | 1 |
| Randomized Crossover Phase | Withdrawal by Subject | 1 |
Baseline characteristics
| Characteristic | Randomized Phase Subjects |
|---|---|
| Age, Continuous | 47.9 years STANDARD_DEVIATION 7.7 |
| Baseline VAS back pain score | 7.75 units on a scale STANDARD_DEVIATION 1.13 |
| Region of Enrollment United Kingdom | 24 participants |
| Sex: Female, Male Female | 8 Participants |
| Sex: Female, Male Male | 16 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk |
|---|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 24 | 0 / 24 | 0 / 24 | 0 / 24 |
| other Total, other adverse events | 0 / 24 | 0 / 24 | 2 / 24 | 0 / 24 |
| serious Total, serious adverse events | 0 / 24 | 1 / 24 | 0 / 24 | 1 / 24 |
Outcome results
Primary
Visual Analog Scale (VAS) on Back Pain
Visual Analog Scale (VAS) back pain scores were recorded once a day on a multi-day diary, where subjects rate the pain by making a vertical slash mark through the 0-10cm line that best describes their pain during the last 24 hours, with 0 = No pain and 10 = Worst pain imaginable. The higher VAS back pain score represented worse back pain. The average VAS back pain scores from the last three days of diary prior to the follow-up visits were used for analysis.
Time frame: 12 weeks
Population: Per-protocol population, subjects who followed the protocol and provided data for all four randomized crossover period were included in the analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Sham | Visual Analog Scale (VAS) on Back Pain | 4.83 units on a scale | Standard Deviation 2.45 |
| 1200 Hz | Visual Analog Scale (VAS) on Back Pain | 4.51 units on a scale | Standard Deviation 1.87 |
| 3030 Hz | Visual Analog Scale (VAS) on Back Pain | 4.57 units on a scale | Standard Deviation 2.09 |
| 5882 Hz | Visual Analog Scale (VAS) on Back Pain | 3.22 units on a scale | Standard Deviation 1.98 |
p-value: 0.002Mixed Models Analysis