Burst or tonic stimulation? Results of a placebo controlled, double blinded, randomized study for the treatment of FBSS patients – 3y follow-up
Jan Vesper, MD, PhD, Phillip Slotty, MD, PhD, J. Maciaczyk, MD, PhD, Stefan Schu, MD * Funct. NS and STX, Düsseldorf, Germany
•SCS has been an important part of the pain physician’s continuum of care since its first reported use in 1967
•Since then, the efficacy of SCS in relieving pain from failed back surgery syndrome (FBSS) has been demonstrated in two randomized, controlled studies.1,2
•A recent meta-analysis of spinal cord stimulation studies suggests that up to 77% of patients obtain good pain relief with tonic stimulation.3
However despite the success of SCS, there remains a small but clinically relevant patient population that are SCS non-responders
This may include:
–Patients who fail an initial SCS trial procedure
–Patients who initially respond at trial, and then experience a gradual decline in response (coverage and/or pain suppression) which is not able to be recaptured
–Patients with complex back pain of severe intensity, which is inadequately addressed via tonic SCS.
§consists of intermittent packets of closely spaced stimuli.
§40 Hz burst rate with five intra-burst pulses at 500 Hz
§Each 500 Hz pulse is 1ms in duration with a 1ms interpulse interval.
§Only BursDR mimics the natural firing patterns
The purpose of this prospective, randomized, double-blind placebo-controlled study was to evaluate the effectiveness of Burst on FBSS patients.
Twenty patients with FBSS and a preexisting SCS system each received three treatment allocations in random order for a period of one week: 500-Hz tonic stimulation, burst stimulation, and placebo stimulation. The primary outcome measure was pain intensity measured on a numerical rating scale (NRS). Secondary outcome measures were pain quality measured using the Short-Form McGill Pain Questionnaire (SFMPQ) and safety. Additional data were collected relating to pain-related disability measured using the Oswestry Disability Index (ODI).
•Patients were randomized to 1 of 6 treatment sequences (ABC, BCA, CAB, ACB, CBA, BAC), where A represents sub-threshold high frequency tonic SCS (500 Hz), B represents burst SCS, and C represents placebo. All patients then underwent 1 week of each stimulation mode according to their assigned group.
•The mean numerical rating scale (NRS) score increased from 5.6 (baseline) to 7.1 and 8.3 during high frequency tonic SCS and placebo SCS, respectively (p>0.05 between high frequency tonic SCS and placebo group).
•Burst SCS significantly reduced NRS scores and Short-Form McGill Pain Questionnaire scores (SF-MPQ) compared to both high frequency tonic SCS and placebo (both p values < 0.05).
•Significantly more patients (80%) preferred burst SCS over all other stimulation modes (p=0.0004).
•No adverse events were reported.
• Directionally Burst provided more benefit on the ODI however this did not meet statistical significance
This prospective, randomized, double-blind, placebo-controlled crossover study assessed the efficacy of burst SCS in 20 patients diagnosed with FBSS who were receiving tonic SCS for a minimum of 3 months.
–Demonstrate the safety and effectiveness of a neurostimulation system that delivers both Burst and tonic stimulation
–Demonstrate non-inferiority of overall pain with Burst versus tonic stimulation
Multi-center, prospective, randomized (1:1)
Crossover design (each subject was their own control)
76 subjects required to perform primary endpoint analysis
Each patient had a device that could deliver both tonic and Burst stimulation
Overall, burst stimulation resulted in significantly better pain relief and improved pain quality in the short term compared with 500-Hz tonic stimulation and placebo stimulation and was preferred by the majority of patients.
•stimulation lead to a significant improvement of SCS therapy
•is able to suppress pain equally or even better than tonic stimulation
•significantly reduces the SCS non responder rate
•is a unique method to influence the medial pathway (emotion, cognition, affect)
•is long-term effective!