Accepted

The objective of this prospective, multicenter study is to characterize responses to percutaneous medial branch peripheral nerve stimulation (PNS) to determine if results from earlier, smaller single-center studies and reports were generalizable when performed at a larger number and wider variety of centers in patients recalcitrant to non-surgical treatments. Participants with chronic axial low back pain were implanted with percutaneous PNS leads targeting the lumbar medial branch nerves for up to 60 days, after which the leads were removed. Participants were followed long-term for 12 months after the 2-month PNS treatment. Data collection is complete for visits through end of treatment with PNS (Primary Endpoint) and 6 months after lead removal (8 months after start of treatment), with some participant follow-up visits thereafter in progress. Clinically and statistically significant reductions in pain intensity, disability, and pain interference were reported by a majority of participants. Seventy-three percent of participants were successes for the Primary Endpoint, reporting clinically significant (≥30%) reductions in back pain intensity after the 2-month percutaneous PNS treatment (n=54/74). While prospective follow up is ongoing, among those who had already completed the long-term follow up visits (n=51), reductions in pain intensity, disability, and pain interference were sustained in a majority of participants through 14 months after the start of treatment. Given the minimally invasive, non-destructive nature of percutaneous PNS and the significant benefits experienced by participants who were recalcitrant to non-surgical treatments, percutaneous PNS may provide a promising first-line neurostimulation treatment option for patients with chronic axial back pain.

Chronic low back pain (CLBP) is a global health problem associated with an increasing burden on individuals, health care systems, and society. Common treatments for people with CLBP produce, on average, small short-term improvements in pain and function compared with minimal care. The RESOLVE trial randomly allocated 276 people with CLBP to a new complex treatment strategy, pain education integrated with graded sensorimotor precision training (RESOLVE), or a sham control. The RESOLVE treatment was developed within a theoretical framework to target possible treatment mechanisms associated with CLBP development and persistence.

Knowledge of etiological mechanisms underlying whiplash-associated disorders (WAD) is incomplete. Localisation and quantification of peripheral musculoskeletal injury and inflammation in WAD would facilitate diagnosis, strengthen patients' subjective pain reports and aid clinical decisions, all of which could lead to improved treatment. In this longitudinal observational study we evaluated combined [11C]D-deprenyl positron emission tomography and computed tomography (PET-CT)) after acute whiplash injury and at 6 month follow-up. Sixteen adult patients (mean age 33 years) with whiplash injury grade II were recruited at the emergency department. [11C]D-deprenyl PET-CT, subjective pain levels, self-rated neck disability and active cervical range of motion were recorded within seven days after injury, and again at six month follow up. Imaging results showed possible tissue injuries after acute whiplash with an altered [11C]D-deprenyl uptake in the cervical bone structures and facet joints, associated with subjective pain locale and levels, as well as self-rated disability. At follow up, some patients had recovered, and some showed persistent symptoms, and reductions in [11C]D-deprenyl uptake correlated to reductions in pain levels. These findings help identify affected peripheral structures in whiplash injury and strengthen the idea that PET/CT detectable organic lesions in peripheral tissue are relevant for the development of persistent pain and disability in whiplash injury.