BurstDR Spinal Cord Stimulation Versus Sham in Established Responders

BurstDR spinal cord stimulation is a paresthesia-free neuromodulation therapy used for the treatment of chronic pain. Although clinical studies have demonstrated beneficial outcomes with BurstDR therapy, the specific contribution of ongoing stimulation, separate from contextual effects, expectation, natural symptom variation, and other nonspecific influences, remains incompletely defined.

This study uses a randomized, double-blind, two-period crossover design in patients who are already implanted with a spinal cord stimulation system and have an established clinical response to BurstDR therapy. Studying established responders avoids potential confounding associated with implantation, postoperative recovery, and initial programming and optimization, and allows the effect of ongoing stimulation to be evaluated under controlled conditions.

Before the randomized treatment periods, each participant will complete a baseline observation under their established active BurstDR settings, followed by a washout period with stimulation switched off. Participants will then undergo two randomized treatment periods: one with active BurstDR stimulation and one with sham stimulation, separated by a second washout period. The order of the two conditions will be randomly assigned, allowing each participant to serve as their own control and thereby reducing the influence of between-patient variability.

During the active condition, stimulation will be delivered using the participant's established clinically effective BurstDR program. During the sham condition, stimulation output will be switched off while study procedures, participant contacts, and data collection will otherwise remain comparable between conditions.

Because BurstDR stimulation is intended to be paresthesia-free, it provides an opportunity for blinded comparison with sham stimulation. Before the randomized treatment phase, a standardized perceptibility assessment will be performed to confirm that participants cannot reliably perceive whether stimulation is active. Device access and information that could reveal treatment allocation will be restricted, and treatment programming will be performed by designated study personnel who are not involved in outcome assessment or the primary analysis.

The crossover and washout design is intended to minimize residual stimulation effects and provide a controlled assessment of the specific contribution of ongoing BurstDR therapy in patients who have previously demonstrated clinical benefit from this treatment.

Inclusion criteria

Participants must meet all of the following:

• Be 18 years of age or older.
• Have an implanted spinal cord stimulation system that can deliver BurstDR stimulation.
• Have had a good and stable response to BurstDR therapy, defined as at least a 50% reduction in pain compared with pain before implantation or before starting BurstDR therapy, maintained for at least 3 months on stable stimulation settings.
• Have had no major change in pain medication for at least 4 weeks before entering the study.
• Be able to understand the study information and provide written informed consent.
• Be willing and able to complete the study's electronic diaries and follow the study procedures.

Exclusion criteria

Participants cannot take part if any of the following apply:

• An active infection, wound problem, or other significant problem at the site of the implanted spinal cord stimulation system.
• A known or suspected problem with the implanted stimulation system that could affect treatment delivery or safety.
• A serious uncontrolled mental health condition, significant problems with memory or thinking, or another condition that could make it difficult to understand the study, provide informed consent, follow the study procedures, or provide reliable study information.
• Planned surgery, planned changes to spinal cord stimulation programming outside the study, or an expected change in pain medication during the study period.
• Pregnancy or breastfeeding.
• Inability to use the electronic diary system when no practical alternative or assistance can be provided.
• Any other medical or personal condition that, in the investigator's judgment, would make participation unsafe or inappropriate.