Placebo Effect in Spinal Cord Electrical Stimulation for Pain
NCT Number: NCT06585033
Acronym: PISCES
Status: NOT_YET_RECRUITING
Study Type: INTERVENTIONAL
Phases: NA
Conditions: Chronic Postoperative Pain
Sponsor: Sahlgrenska University Hospital, Sweden
Sex: ALL
Age: ADULT, OLDER_ADULT
Enrollment: 50
Study Design: Allocation: RANDOMIZED|Intervention Model: CROSSOVER|Masking: TRIPLE (PARTICIPANT, INVESTIGATOR, OUTCOMES_ASSESSOR)|Primary Purpose: TREATMENT
Start Date: 2024-09-15
Completion Date: 2026-08-31

Summary:
Objective: To evaluate if spinal cord stimulation (SCS) performs better than placebo (no stimulation) in the long term to reduce persistent neuropathic leg pain refractory to medication and other conservative treatments in patients who have undergone lumbar spinal surgery.

Study design: Multicenter, double blind, randomized, sham-controlled trial.

After a positive SCS test trial, participants (18-70 years) will be implanted with a non-rechargeable SCS system providing active, subthreshold stimulation and followed for 12 months in a blinded cross-over design. The primary outcome measure is the difference in change in leg pain intensity scores using the Numeric Rating Scale (NRS) between a 3-month period with optimized subthreshold stimulation, and a 3-month period with no stimulation, as compared to baseline. Quality of life, physical functioning, sleep quality, return to work, and reduction in medication use will also be investigated.

Background: Up to 20% of patients who have undergone lumbar spinal surgery experience persistent back/leg pain leading to long-term reduction in functionality and quality of life. SCS is an established and safe, minimally invasive treatment for these patients when no further surgery is indicated and conservative therapies have been found to be ineffective. Placebo-controlled studies, comparing active and sham stimulation, were lacking until recently as traditional SCS relied on the patient feeling the stimulation (paresthesia). Technological progress with development of paresthesia-free stimulation forms now allows for the execution of placebo-controlled studies. A recent trial showing no significant difference in long-term effectiveness between active SCS and sham suffers from significant methodological shortcomings. This necessitates further sham-controlled studies to determine the effectiveness of SCS.

Primary Outcome Measures: Comparison between active subthreshold spinal cord stimulation and sham stimulation in reducing neuropathic leg pain, The difference in change in neuropathic leg pain intensity scores measured by the numeric rating scale (NRS) questionnaire between a 3-month period with subthreshold stimulation and a 3-month period with sham stimulation, as compared to baseline, Baseline and 3+3 months
Secondary Outcome Measures: Comparison between active subthreshold spinal cord stimulation and sham stimulation, Physical functioning measured using the Oswestry Disability Index (ODI) questionnaire, Baseline and 3, 6 and 12 months|Comparison between active subthreshold spinal cord stimulation and sham stimulation, • Quality of life measured using the EuroQoL-5D-5L (EQ-5D-5L) questionnaire, Baseline and 3, 6 and 12 months|Comparison between active subthreshold spinal cord stimulation and sham stimulation, Sleep quality measured using the Pittsburgh Sleep Quality Index (PSQI) questionnaire., Baseline and 3, 6 and 12 months|Comparison between active subthreshold spinal cord stimulation and sham stimulation, Medication use, Baseline and 3, 6 and 12 months|Comparison between active subthreshold spinal cord stimulation and sham stimulation, Number of hours worked per week, Baseline and 3, 6 and 12 months|Comparison between active subthreshold spinal cord stimulation and sham stimulation, The difference in change in neuropathic leg pain intensity scores measured by the numeric rating scale (NRS) questionnaire after patient has chosen preferred stimulation from the 6-month to the 12-month follow-up., Baseline and 12 months