Accepted

While a causal relationship between pain-related fear and spinal movement avoidance in patients with chronic low back pain (CLBP) has frequently been postulated, evidence supporting this relationship is limited. This study aimed to test if decreases in pain-related fear or catastrophizing were associated with improvements in spinal biomechanics, accounting for possible changes in movement-evoked pain.

"Non-inflammatory" pain, pain that is not associated with measures of inflammation, is common in patients with inflammatory arthritis including rheumatoid arthritis (RA). One important cause of non-inflammatory pain is concomitant fibromyalgia. Systematic review has shown that fibromyalgia is common in inflammatory arthritis including RA affecting 1 in 5 patients and is associated with higher disease activity scores due to inflated tender joint count and patient global assessment. Consequently, many patients with RA and concomitant fibromyalgia may fail to reach treatment target and switch to alternate disease modifying drugs frequently. European Alliance of Association for Rheumatology has highlighted that concomitant fibromyalgia is an important consideration in assessing difficult-to-treat RA. The incidence and prevalence of fibromyalgia are higher in RA than the general population raising the possibility that fibromyalgia may be "secondary "to RA rather than a concomitant disease. The precise mechanisms whereby patients with RA develop fibromyalgia are unknown. In this review, we discussed fibromyalgia in RA, its clinical impact and epidemiology as well as data suggesting fibromyalgia might be "secondary". Lastly, we reviewed potential pathogenic mechanisms which included inflammatory cytokines sensitizing nociceptive neurones, temporal summation, also known as windup, from chronic pain and impaired coping from poor quality sleep and mental well-being. Deciphering the exact mechanisms may lead to treatment strategies that prevent development of secondary fibromyalgia and will address a common factor associated with difficult to treat RA.

Voltage-gated sodium channels (Nas) play a crucial electrical signaling role in neurons. Na-isoforms present in peripheral sensory neurons and dorsal root ganglia of the spinal cord are critically involved in pain perception and transmission. While these isoforms, particularly Na1.7, are implicated in neuropathic pain disorders, changes in the functional state and expression levels of these channels have not been extensively studied in vivo. Radiocaine, a fluorine-18 radiotracer based on the local anesthetic lidocaine, a non-selective Na blocker, has previously been used for cardiac Na1.5 imaging using positron-emission tomography (PET). In the present study, we used Radiocaine to visualize changes in neuronal Na expression after neuropathic injury. In rats that underwent unilateral spinal nerve ligation, PET/MR imaging demonstrated significantly higher uptake of Radiocaine into the injured sciatic nerve, as compared to the uninjured sciatic nerve, for up to 32 days post-surgery. Radiocaine, due to its high translational potential, may serve as a novel diagnostic tool for neuropathic pain conditions using PET imaging.

Chronic pain is comorbid with psychiatric disorders, but information on the association of chronic pain with depressive symptoms, generalized anxiety, and suicidal behavior among occupational cohorts is inadequate. We investigated these associations among employed Chilean adults.

Real-world adherence to clinical practice guidelines is often poor, resulting in sub-standard patient care and unnecessary healthcare costs. This study evaluates the effect of a guideline-implementation intervention for the management of low back pain (LBP) in general practice-the Fear Reduction Exercised Early (FREE) approach-on LBP-related injury insurance claims, healthcare utilisation, and costs of treatment.

Complex regional pain syndrome (CRPS) is characterized by pain, limited range of motion, swelling, skin changes, vasomotor instability, and patchy bone demineralization. Conservative management strategies for CRPS include physical and occupational therapy, psychosocial and behavioral therapy, and pharmacotherapy. However, some patients still experience CRPS symptoms after receiving conventional treatments. Therefore, botulinum toxin (BoNT) has been applied to patients with CRPS in several trials considering its analgesic effect in musculoskeletal and neuropathic pain; however, the results were controversial. We conducted the study to explore the effectiveness and safety of BoNT in patients with complex regional pain syndrome (CRPS). A search was performed using the following electronic databases up to 19 October 2022: PubMed, Embase, and Cochrane Library. We included both randomized controlled trials and nonrandomized controlled studies involving patients with complex regional pain syndrome managed with botulinum toxin. Cochrane risk-of-bias tool and Joanna Briggs Institute Critical Appraisal Checklist were used for quality assessment for randomized controlled trials and quasi-experimental studies. Only randomized controlled trials entered the meta-analysis. The primary outcome was the visual analogue scale of pain presented as a weighted mean difference (WMD) and 95% confidence interval (CI). The secondary outcome was the risk of adverse events presented as an odds ratio (OR) with 95% CI. We analyzed eight articles with 176 patients, including three randomized controlled trials with 62 participants. The age of the patients ranged from 23.8 to 51 years old. The duration of the disease ranged from 2.2 to 11.8 years. The proportion of females ranged from 16.6% to 100%. The route of administration of BoNT included: (1) lumbar sympathetic block (LSB), (2) intramuscular injection, (3) subcutaneous or intradermal injection (SC/ID). Improvement in pain was revealed in six studies, and adverse events were all self-limited and temporary. Meta-analysis revealed a significant reduction in pain at the first follow-up between 3 weeks to 1 month after intervention (WMD, -1.036, 95% CI, -1.673 to -0.400) but not at the second follow-up between 2 to 3 months after treatment (WMD, -0.895, 95% CI, -2.249 to 0.458). Subgroup analyses between LSB and SC/ID were nonsignificant at both follow-up periods ( = 0.422, 0.139). The risk of adverse events was similar between the BoNT and control group (OR, 0.698, 95% CI, 0.136 to 3.581). In conclusion, BoNT may be effective and safe for alleviating pain in patients with CRPS. However, we could not draw definite conclusions due to small sample size and high between-study heterogeneity. The limited number of participants may conceal the possibility of serious adverse events. Further large-scale randomized controlled trials are warranted to delineate the role of BoNT in CRPS.

Angiographic vasoconstriction in reversible cerebral vasoconstriction syndrome (RCVS) is often undetectable at symptom onset and the diagnosis relies on clinical presentation. Although thunderclap headache is a hallmark feature of RCVS, the incidence and predictors of long-term headaches (LTH) are incompletely understood. Our study aims were twofold: to examine the sensitivity and specificity of a recently developed score (RCVS) for vasoconstriction detection in a real-world clinical context and describe the incidence and predictors of LTH beyond the acute phase of RCVS.

The COVID-19 outbreak disrupted medical access for patients receiving chronic opioid therapy. This study investigated their prescription opioid dosages before and after the 2020 outbreak in Taiwan.

The hub-and-spoke telehealth model leverages centrally located providers who utilize telehealth technology to bring specialized care to medically underserved areas. This model has the potential to promote equitable access to healthcare. However, few studies address how to facilitate the adoption and implementation of hub-and-spoke telehealth. We examined spoke site providers' experiences with TelePain, a national hub-and-spoke model of interdisciplinary chronic pain care, with a focus on improving future implementation. We conducted semi-structured individual interviews (20-45 min) with 27 VA spoke site providers via teleconferencing between August 2020 and February 2021. Interview transcripts were coded in Atlas.ti 8.0 using deductive (identified a priori and used to build the interview guide) and inductive (emerging) codes. Our analysis identified the following themes stressed by the spoke sites: (1) spoke sites needed to envision how TelePain services would work at their site before deciding to adopt; (2) TelePain implementation needed to fit into local existing care processes; (3) hub sites needed to understand spoke sites' context (e.g., via needs assessment) to tailor the services accordingly, and (4) hub-and-spoke sites needed to establish bidirectional communication. Our findings provide a practical guide to improve future rollout of hub-and-spoke telehealth models. Recommendations focus on the role of the hub site in promoting program adoption by (1) developing a clear and detailed marketing plan and (2) considering how the program can be adapted to fit the local spoke site context. To improve implementation, hub-and-spoke sites must establish ongoing and consistent bidirectional communication; this is particularly critical in the everchanging post-peak pandemic healthcare system. An important next step is the development of recommendations and guidelines for implementing hub-and-spoke telehealth, as well as examining pain outcomes for patients touched by this program.