Effect of Spinal Cord Burst Stimulation vs Placebo Stimulation on Disability in Patients With Chronic Radicular Pain After Lumbar Spine Surgery

Abstract

ImportanceThe use of spinal cord stimulation for chronic pain after lumbar spine surgery is increasing, yet rigorous evidence of its efficacy is lacking.ObjectiveTo investigate the efficacy of spinal cord burst stimulation, which involves the placement of an implantable pulse generator connected to electrodes with leads that travel into the epidural space posterior to the spinal cord dorsal columns, in patients with chronic radiculopathy after surgery for degenerative lumbar spine disorders.Design, Setting, and ParticipantsThis placebo-controlled, crossover, randomized clinical trial in 50 patients was conducted at St Olavs University Hospital in Norway, with study enrollment from September 5, 2018, through April 28, 2021. The date of final follow-up was May 20, 2022.InterventionsPatients underwent two 3-month periods with spinal cord burst stimulation and two 3-month periods with placebo stimulation in a randomized order. Burst stimulation consisted of closely spaced, high-frequency electrical stimuli delivered to the spinal cord. The stimulus consisted of a 40-Hz burst mode of constant-current stimuli with 4 spikes per burst and an amplitude corresponding to 50% to 70% of the paresthesia perception threshold.Main Outcomes and MeasuresThe primary outcome was difference in change from baseline in the self-reported Oswestry Disability Index (ODI; range, 0 points [no disability] to 100 points [maximum disability]; the minimal clinically important difference was 10 points) score between periods with burst stimulation and placebo stimulation. The secondary outcomes were leg and back pain, quality of life, physical activity levels, and adverse events.ResultsAmong 50 patients who were randomized (mean age, 52.2 [SD, 9.9] years; 27 [54%] were women), 47 (94%) had at least 1 follow-up ODI score and 42 (84%) completed all stimulation randomization periods and ODI measurements. The mean ODI score at baseline was 44.7 points and the mean changes in ODI score were −10.6 points for the burst stimulation periods and −9.3 points for the placebo stimulation periods, resulting in a mean between-group difference of −1.3 points (95% CI, −3.9 to 1.3 points; P = .32). None of the prespecified secondary outcomes showed a significant difference. Nine patients (18%) experienced adverse events, including 4 (8%) who required surgical revision of the implanted system.Conclusions and RelevanceAmong patients with chronic radicular pain after lumbar spine surgery, spinal cord burst stimulation, compared with placebo stimulation, after placement of a spinal cord stimulator resulted in no significant difference in the change from baseline in self-reported back pain–related disability.Trial RegistrationClinicalTrials.gov Identifier: NCT03546738

Issues in design, conduct, and conclusions of JAMA's Hara et al.'s randomized clinical trial of spinal cord burst stimulation versus placebo stimulation on disability in patients with chronic radicular pain after lumbar spine surgery

“…The authors report conducting a 2‐week SCS testing period with tonic stimulation using an external neurostimulator and implantation of those patients reporting a reduction of at least 2‐points for leg pain using a NRS. In the protocol (supplement 2) a successful testing period was defined as ≥30% pain reduction 1 . A 2‐point reduction in NRS does not correspond to ≥30% pain reduction, and both values deviate significantly from international guideline recommendations of a requirement of ≥50% pain reduction at trial to proceed to implant 4 .…”

“…Hara et al recently published a randomized controlled study comparing burst spinal cord stimulation (SCS) to sham 1 . The authors conclude that there was no difference between four spike burst SCS and sham SCS in patients with chronic radicular pain after lumbar spine surgery.…”

Renewed Doubts About Spinal Cord Stimulation for Chronic Pain—as Its Popularity Soars

“…This was a placebo-controlled crossover study of 50 subjects with chronic radicular pain after lumbar surgery. (See Hara et al, 2022. )…”

Neurostimulation in the patient with chronic pain: forecasting the future with data from the present – data-driven analysis or just dreams?

“…For many years, SCS has been based exclusively on the application of a tonic, suprathreshold, low-intensity current. In the last decade, a whole new series of new programming modalities and therapeutic targets have appeared: ultra-high-frequency stimulation (10 kHz);37 burst stimulation,15 38 DR ganglion stimulation,39 and other technical or therapeutical targets proposals 19 40 41…”

“…Everything previously presented, takes on even more interest, in light of the recent article published by Hara et al 15. The evidence supporting SCS, and the possible placebo effect that the intervention itself and the use of technology implies, is reviewed.…”