Accepted

The previous research showed contradictions in the relationships between psychological flexibility processes and functioning. This meta-analysis is the first to provide a comprehensive meta-analysis of the associations between six core processes of psychological flexibility and functioning among chronic pain patients. Four databases were searched (PsycINFO; PubMed; CINAHL; Web of Science) along with reference lists. Thirty-six cross-sectional studies were included (7,812 chronic pain patients). A three-level meta-analytic model was used to examine the associations. The publication bias was assessed with the Egger test, funnel plot, and -curve analysis. Significant associations were found between functioning and six processes of psychological flexibility (i.e., acceptance, defusion, present moment, committed action, self as context, and values). Except for the relationship between defusion and functioning, the relationships between the other five psychological flexibility processes and functioning were all moderated by domains of functioning. No moderators were found regarding age, percentage of females, country, or type of instrument used to measure functioning. These findings may carry significant implications for chronic pain patients and clinical workers. It might be more effective to focus on functioning-related psychological flexibility processes rather than all therapy packages if the relationships between functioning and specific processes of psychological flexibility were better informed. Limitations were also discussed.

Chronic neck pain is associated with sensorimotor dysfunctions, which may develop symptoms, affect daily activities, and prevent recovery. Feasible, reliable, and valid objective methods for the assessment of sensorimotor functions are important to identify movement impairments and guide interventions. The aim of this study was to investigate the discriminative validity of a clinical cervical movement sense test, using a laser pointer and an automatic video-based scoring system. Individuals with chronic neck pain of idiopathic onset (INP), traumatic onset (TNP), and healthy controls (CON) were tested. Associations between movement sense and neck disability were examined and the repeatability of the test was investigated. A total of 106 participants (26 INP, 28 TNP, and 52 CON) were included in a cross-sectional study. , and (i.e., normalized acuity by dividing acuity with movement time) were used as outcome measures. ANOVAs were used for group comparisons and Pearson correlations for associations between movement sense variables and neck disability index (NDI). Notably, 60 of the participants (30 CON, 17 INP, and 13 TNP) performed the test on a second occasion to explore test-retest reliability. Results revealed a reduced for both INP and TNP compared with CON ( < 0.05). The neck pain groups had similar but longer compared with CON. Among TNP, there was a fair positive correlation between and NDI, while there was a negative correlation between and NDI among INP. Reliability measures showed good to excellent ICC values between tests, but standard error of measurements (SEM) and minimal detectable change (MDC) scores were high. The results showed that is a valuable measure to identify disturbed cervical movement sense among INP and TNP. While was similar between the groups, different strategies, such as longer , to perform the task among neck patient groups were used. Few differences were identified between the neck pain groups, but altered strategies may exist. Reliability was acceptable, and the test is feasible to perform in the clinic. However, the technical complexity of the automated image analysis is a concern. Future developments will provide more feasible solutions.

Opioids are powerful analgesics that elicit acute antinociceptive effects through their action the mu opioid receptor (MOR). However opioids are ineffective for chronic pain management, in part because continuous activation of MORs induces adaptive changes at the receptor level and downstream signaling molecules. These adaptations include a decrease in receptor-effector coupling and changes to second messenger systems that can counteract the persistent activation of MORs by opioid agonists. Homeostatic regulation of MORs and downstream signaling cascades are viewed as precursors to developing tolerance. However, despite numerous studies identifying crucial mechanisms that contribute to opioid tolerance, no single regulatory mechanism that governs tolerance in at the cellular and systems level has been identified. Opioid tolerance is a multifaceted process that involves both individual neurons that contain MORs and neuronal circuits that undergo adaptations following continuous MOR activation. The most proximal event is the agonist/receptor interaction leading to acute cellular actions. This review discusses our understanding of mechanisms that mediate cellular tolerance after chronic opioid treatment that, in part, is mediated by agonist/receptor interaction acutely.

Electroacupuncture (EA) has benefits for neuropathic pain. However, the underlying mechanisms are still unknown. The current study explores the underlying mechanisms of EA in neuropathic pain of chronic constriction injury (CCI) rats. . Overall, 126 Sprague-Dawley (200-250 g) rats were divided into nine groups randomly: the sham-operated, CCI, CCI+EA, CCI+sham EA, CCI+NS, CCI+AAV-NC, CCI+AAV-miR-206-3p, CCI+EA+NS, and CCI+EA+AAV-miR-206-3p groups. The animals were sacrificed 14 days postsurgery. Mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) tests were used to determine differences in neurobehavioral manifestations. qPCR, western blotting, and immunofluorescence (IF) were carried out to detect the expression levels of miR-206-3p, BDNF, BAX/Bcl-2, TNF-, and IL-6. Nissl staining was measured to observe morphological changes in neurons. Transmission electron microscopy (TEM) was employed to evaluate microscopic changes in dorsal horn synapses.

There is evidence of altered corticolimbic circuitry in adults with chronic pain, but relatively little is known of functional brain mechanisms in adolescents with neuropathic pain (NeuP). Pediatric NeuP is etiologically and phenotypically different from NeuP in adults, highlighting the need for pediatric-focused research. The amygdala is a key limbic region with important roles in the emotional-affective dimension of pain and in pain modulation.

The research and clinical application of the noninvasive brain stimulation (NIBS) technique in the treatment of neuropathic pain (NP) are increasing. In this review article, we outline the effectiveness and limitations of the NIBS approach in treating common central neuropathic pain (CNP). This article summarizes the research progress of NIBS in the treatment of different CNPs and describes the effects and mechanisms of these methods on different CNPs. Repetitive transcranial magnetic stimulation (rTMS) analgesic research has been relatively mature and applied to a variety of CNP treatments. But the optimal stimulation targets, stimulation intensity, and stimulation time of transcranial direct current stimulation (tDCS) for each type of CNP are still difficult to identify. The analgesic mechanism of rTMS is similar to that of tDCS, both of which change cortical excitability and synaptic plasticity, regulate the release of related neurotransmitters and affect the structural and functional connections of brain regions associated with pain processing and regulation. Some deficiencies are found in current NIBS relevant studies, such as small sample size, difficulty to avoid placebo effect, and insufficient research on analgesia mechanism. Future research should gradually carry out large-scale, multicenter studies to test the stability and reliability of the analgesic effects of NIBS.