Literature Review - May 2021
May 1, 2021
Editor’s note: “Literature Review” is a feature designed to provide you with brief summaries of recent articles of interest, particularly from sources that our readers might not normally consume.
Percutaneous Peripheral Nerve Stimulation of the Medial Branch Nerves for the Treatment of Chronic Axial Back Pain in Patients After Radiofrequency Ablation
Deer TR, Gilmore CA, Desai MJ, et al. Pain Med. 2021;22(3):548-560. https://doi.org/10.1093/pm/pnaa432.
Selection and summary by Sudheer Potru, DO
Introduction: While lumbar medial branch radiofrequency ablation is an effective treatment for axial low back pain, it involves denervation of the multifidus and often yields decreasing levels of pain relief when done repeatedly over time. An axial pain treatment that is motor-sparing and long-lasting is desired.
Methods: A prospective, multicenter trial was performed in 15 patients with chronic axial low back pain who had medial branch radiofrequency ablation greater than six months prior to enrollment. Percutaneous peripheral nerve stimulation (PNS) leads were placed in all subjects near the medial branch nerves at the level closest to the center of the painful region of the low back for a total of 60 days. Patients were excluded if they had radicular pain, a history of prior lumbar surgery, scoliosis, pending litigation, or active depression identified by a score >20 on the Beck Depression Inventory. Inventories were used to measure pain interference, pain intensity, and disability at two and five months post-placement.
Results: The average pain intensity score was reduced from 6.3 to 2.4 (SD=1.6, p<0.0001). Of the 15 participants, 13 had a clinically meaningful reduction in average pain intensity and disability (at least 10-point reduction in Oswestry Disability Index), and 12 out of 15 had clinically significant reduction in pain interference (at least 30% reduction in Brief Pain Inventory-9 score).
At five months, 11 out of 15 participants (73%) experienced clinically significant reduction in pain intensity (at least 50%) and pain interference, and 67% of participants reported clinically significant improvements in disability. All but one patient (93%) had clinically significant improvement in at least one of the three major outcomes listed. Four participants experienced lead migration or dislodgement and received lead replacements per protocol.
Key point: Peripheral nerve stimulation may be a highly effective treatment for those with chronic axial low back pain and should be considered as part of the treatment algorithm moving forward.
Optimized Acupuncture Treatment (Acupuncture and Intradermal Needling) for Cervical Spondylosis-Related Neck Pain: A Multicenter Randomized Controlled Trial
Chen L, Minying L, Fan L, et al. Pain. 2021;162(3):728-739. https://doi.org/10.1097/j.pain.0000000000002071.
Selection and summary by Sudheer Potru, DO
Introduction: Neck pain due to cervical spondylosis is a significant public health issue with a large economic burden. Although helpful treatments exist, including physical therapy and cervical medial branch radiofrequency ablation, many of these lack conclusive evidence.
Methods: A multicenter, single-blinded, randomized controlled trial was performed to study the efficacy of optimized acupuncture versus shallow acupuncture and sham acupuncture on cervical spondylosis-related (CS-R) neck pain. Typically, in the authors’ environment in China, daily acupuncture is employed for CS-R neck pain and is associated with poor compliance and lack of efficacy. Instead the authors utilized an optimized acupuncture regimen, which allowed for treatment every other day and included both acupuncture and intradermal needling.
Patients were included if they had a diagnosis of cervical spondylosis based on imaging, age range 18-60 years, multiple episodes of neck pain > 30 minutes in the previous month, VAS score >3 once in the past week, and no history of acupuncture treatment in the previous three months. Exclusion criteria included diagnosis of cervical spondylosis with myelopathy, presence of systemic diseases (including tumors and diabetes mellitus), history of neck trauma (including vertebral fracture or surgery), history of congenital spinal abnormality, neurological impairment related to myasthenia gravis or abnormal reflexes, and pregnancy/lactation.
Each treatment group had nearly 300 participants. All patients in all groups received treatment from the same nine providers for four weeks. Sham acupuncture points were set close to the actual acupuncture points to prevent patient ability to distinguish location. The Northwick Park Neck Pain Questionnaire (NPQ) and Short Form-36 (for quality-of-life measures) were assessed at four weeks (immediately post-intervention), eight weeks, and 16 weeks.
Results: At weeks 4, 8, and 16, significant NPQ differences were observed between the optimized acupuncture group and the shallow and sham groups, although all three cohorts demonstrated significant improvements in both NPQ and SF-36 over the 16-week study period. Most SF-36 scores were higher in the optimized acupuncture groups versus the shallow and sham cohorts. However, wide variability existed in the treatment effects overall.
Key point: An optimized acupuncture regimen including intradermal needling may be more assistive than regular acupuncture in treatment of cervical spondylotic neck pain and could be an effective adjunct for this type of neck pain.