Results of a trial published in the journal Pain Medicine reports that percutaneous peripheral nerve stimulation (PNS) show “clinically significant” reductions in pain, disability, and pain interface in patients with chronic lower back pain.
Authors, Timothy R Deer et al, note that lumbar radiofrequency ablation (RFA) is commonly used as an intervention in lower back pain. However, they claim that while RFA is often successful, pain typically returns and the procedure involves the destruction of the medial branch nerves.
The object of this prospective, multicentre trial is to demonstrate the potential use of percutaneous PNS as a minimally invasive, non-destructive, motor-sparing alternative to repeat RFA or more invasive surgical procedures.
A total of 15 patients with a history of chronic axial lower back pain who previously had been treated with RFA were included in the study. Participants were an average of 57.5 years of age, had a mean body mass index (BMI) of 29.1 and had experienced chronic axial lower back pain for an average of 12.5 years. All participants had previously undergone lumbar medial branch RFA for axial lower back pain for a median of one year, and had an average reported lower back pain intensity of 6.3 (scored 0–10). The most common diagnoses or proposed etiologies for the participants’ axial lower back pain were lumbar spondylosis (40%; n=6/15), degenerative disc disease (27%; n=4/15), and nonspecific lower back pain (20%; n=3/15).
Subjects were implanted with percutaneous PNS leads targeting the medial branch nerves. Stimulation was programmed to deliver comfortable cyclical activation of the multifidus 6–12 hours a day for up to 60 days. After this two month period, leads were withdrawn.
Participants recorded their daily pain levels and analgesic medication consumption in weekly diaries. Secondary outcomes—such as disability and pain interference—were assessed with validated questionnaires, and adverse events were assessed up to three months after leads were removed.
Investigators found a “highly clinically significant” reduction in the average pain intensity in the majority of participants, with an improvement of ≥50% in 67% (10) of participants’ pain. Additionally, the authors report improvements in the functional outcomes for the majority of patients. An improvement in disability was seen in 87% (13) patients, and an improvement in pain interference was seen in 80% (12). Finally, five months after PNS, 93% (14) of patients reported improvement in one or more of the trials’ outcome measures.
The authors concluded, “Percutaneous PNS has the potential to shift the pain management paradigm by providing an effective, non-destructive, motor-sparing neuromodulation treatment.”