IntroductionPeripheral nerve stimulation (PNS) has historically been used to treat chronic pain, but generally requires implantation of a permanent system for sustained relief. A recent study found that a 60-day PNS treatment decreases post-amputation pain, and the current work investigates longer-term outcomes out to 12 months in the same cohort.MethodsAs previously reported, 28 traumatic lower extremity amputees with residual and/or phantom limb pain were randomized to receive 8 weeks of PNS (group 1) or 4 weeks of placebo followed by a crossover 4 weeks of PNS (group 2). Percutaneous leads were implanted under ultrasound guidance targeting the femoral and sciatic nerves. During follow-up, changes in average pain and pain interference were assessed using the Brief Pain Inventory–Short Form and comparing with baseline.ResultsSignificantly more participants in group 1 reported ≥50% reductions in average weekly pain at 12 months (67%, 6/9) compared with group 2 at the end of the placebo period (0%, 0/14, p=0.001). Similarly, 56% (5/9) of participants in group 1 reported ≥50% reductions in pain interference at 12 months, compared with 2/13 (15%, p=0.074) in group 2 at crossover. Reductions in depression were also statistically significantly greater at 12 months in group 1 compared with group 2 at crossover.ConclusionsThis work suggests that percutaneous PNS delivered over a 60-day period may provide significant carry-over effects including pain relief, potentially avoiding the need for a permanently implanted system while enabling improved function in patients with chronic pain.Trial registration numberNCT01996254.
Peripheral Nerve Stimulation of the Saphenous and Superior Lateral Genicular Nerves for Chronic Pain After Knee Surgery
