Data and Clinical Outcomes
Compelling clinical evidence demonstrates the long-term success of spinal cord stimulation.
PROCESS Clinical Study Results
The Medtronic (MDT) PROCESS Study is the first randomized, controlled, multicenter trial comparing the effectiveness of spinal cord stimulation (SCS) plus conventional medical management (CMM) versus CMM alone.
Leg Pain Relief (≥ 50%) at 6 Months1
24 (48%) patients achieved the primary outcome of a ≥ 50% leg pain relief as compared to 4 (9%) patients in the CMM alone group (p < 0.001), as shown in Figure 1.
NOTE: With the VAS, patients rate level of pain on a scale from 0 (no pain) to 10 (worst possible pain); the scores are then graded and given a percentage score.
Leg Pain Relief (≥ 50%) at 24 Months2
In an as treated analysis2, 34 (47%) patients who received MDT SCS+CMM achieved the primary outcome versus 1 (7%) who received CMM along (p = 0.02), as shown in Figure 2.
In a modified ITT analysis2, 17 (37%) patients randomized to MDT SCS+CMM and 1 (2%) randomized to CMM alone achieved the primary outcome of ≥ 50% leg pain relief (p = 0.003), as shown in Figure 2.
NOTE: An ITT analysis compares all data from patients in the groups to which they were randomized. The modified ITT means that for all patients who requested to cross over; at 6 months, they were considered to have < 50% pain relief. An as treated analysis compares the groups based on the treatment the patient is receiving at the time of the visit.
Leg Pain Relief: VAS Scores from Baseline to 24 Months (n = 42)2
Compared to baseline, the 42 patients continuing MDT SCS+CMM experienced statistically significantly lower levels of leg pain (P < 0.0001), as shown in Figure 3.
Leg Pain Relief (≥ 30%): Patients Continuing MDT SCS+CMM at 24 Months
69% of the 42 MDT SCS+CMM patients continuing therapy achieved (≥ 30%) leg pain relief3, as shown in Figure 4.
NOTE: A 30% reduction in pain is clinically meaningful and is equivalent to categorical ratings of “moderate relief” or “much improved.”4-6
Function: As Measured by the Oswestry Disability Index (ODI) at 6 and 24 Months1,2
MDT SCS+CMM patients experienced superior function on the ODI compared with CMM patients (p < 0.001).
Compared to baseline, the 42 patients continuing MDT SCS+CMM experienced statistically significant improvement in functional capacity (p = 0.0002)8, as shown in Figure 5.
At 6 months and compared with CMM, SCS patients experienced significant improvements in 7 of 10 subdimensions on the ODI (p ≤ 0.05), as shown in Figure 6.
Within group SCS or CMM difference
NS p > 0.05
* p ≤ 0.05
** p ≤ 0.01
*** p ≤ 0.001
Between group difference
NS p > 0.05
† p ≤ 0.05
†† p ≤ 0.01
††† p ≤ 0.001
Compared with baseline, 42 patients randomized to SCS continued to experience significant improvements in 7 of 10 subdimensions on the ODI at 24 months, as shown in Figure 7.
In addition, at 24 months, ODI lifting scores improved for patients randomized to SCS therapy.
Within group comparison to baseline
* p ≤ 0.05
** p ≤ 0.01
*** p ≤ 0.001
NOTE: The ODI score is produced from patient-completed questionnaires that include 6 statements in each of 10 sections concerning impairments like pain and abilities such as personal care, lifting, reading, driving, and recreation. The scale is interpreted as: 0%-20% (minimal disability); 20%-40% (moderate disability); 40%-60% (severe disability); 60%-80% (severely disabled in several areas of life/crippled); 80%-100% (bed bound or exaggerating symptoms).6
Treatment Satisfaction: Patients Continuing Spinal Cord Stimulation +CMM at 24 Months2
At 24 months, 93% of the 42 patients continuing spinal cord stimulation+CMM declared that "based on their experience so far, they would have agreed to treatment."
Adverse Events from Medtronic PROCESS Randomized Controlled Trial2
Of the 42 patients continuing SCS+CMM at 24 months, 23 patients (55%) did not experience any SCS-related complications, and 19 patients experienced a total of 34 SCS-related complications. For 13 patients, a surgical revision was required to resolve the event.
- Kumar K, Taylor RS, Jacques L et al. Spinal cord stimulation versus conventional medical management for neuropathic pain: a multicentre randomised controlled trial in patients with failed back surgery syndrome. Pain 2007;132:179-188.
- Kumar, et. al. The effects of spinal cord stimulation in neuropathic pain are sustained: a 24-month follow-up of the prospective randomized controlled multicenter trial of the effectiveness of spinal cord stimulation. Neurosurgery. 2008;63(4)762-770.
- Cruccu G, Anand P, Attal N, et al. EFNS guidelines on neuropathic pain assessment. Eur J Neurol. 2004;11:153-162.
- Farrar JT, Dworkin RH, Max MB. Use of the cumulative proportion of responders analysis graph to present pain data over a range of cut-off points: making clinical trial data more understandable. J Pain Symptom Manage. 2006;31(4):369-377.
- Teng J, Mekhail N. Neuropathic pain: mechanisms and treatment options. Pain Practice. 2003;3(1):8-21.
- Fairbank JC, Couper J, Davies JB, O’Brien JP. The Oswestry low back pain disability questionnaire. Physiotherapy. 1980;66(8):271-273.
RestoreSensor Clinical Study Results
The RestoreSensor® Clinical Study demonstrates that patients using AdaptiveStim® experienced improved pain relief with no loss of convenience, or improved convenience with no loss of pain relief, compared with using conventional stimulation.
- 86.5% of patients in the clinical study reported improved pain relief with no loss of convenience, or improved convenience with no loss of pain relief, compared with using conventional stimulation
- 80.3% of patients reported improvement in comfort during position changes
- 88.7% of patients received clinical benefit with AdaptiveStim as reported by clinical study physicians
- 90.1% of patients said they intended to leave AdaptiveStim turned on all or most of the time or turn it on or off as needed
AdaptiveStim is safe and effective in providing pain relief and/or convenience compared with conventional stimulation.
- Patients reported improved comfort during position changes with this new technology
- AdaptiveStim represents an important innovation in spinal cord stimulation therapy.
- When selecting a spinal cord stimulation system for the treatment of chronic trunk and/or limb pain, the benefits of AdaptiveStim merit serious consideration by clinicians and patients, especially for patients who experience positional uncomfortable stimulation during the trial stimulation period.
The RestoreSensor Clinical Study was a prospective, multicenter, open-label, randomized, crossover, 16-week trial. Study details can be found in the Clinical Summary for Advanced Pain Therapy Using Neurostimulation for Chronic Pain.