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Photobiomodulation therapy is not better than placebo in patients with chronic non-specific low back pain: a randomised placebo-controlled trial.

Photobiomodulation therapy (PBMT) has been used in several musculoskeletal disorders to reduce pain, inflammation and promoting tissue regeneration. The current evidence about the effects of PBMT on low back pain are still conflicting. We aimed to evaluate the effects of photobiomodulation therapy against placebo on pain intensity and disability in patients with chronic non-specific low back pain. This was a prospectively registered, randomised placebo-controlled trial, with blinded patients, therapists and assessors. The study was conducted on an outpatient physical therapy clinic in Brazil, between April 2017 and May 2019. A total of 148 patients with chronic non-specific low back pain were randomised to either active photobiomodulation therapy (n=74) or placebo (n=74). Patients from both groups received 12 treatment sessions, 3 times a week, for 4 weeks. Patients from both groups also received an educational booklet based on 'The Back Book'. Clinical outcomes were measured at baseline and at follow-up appointments at 4 weeks, 3, 6 and 12 months after randomization. The primary outcomes were pain intensity and disability measured at 4 weeks. We estimated the treatment effects using linear mixed models following the principles of intention to treat. There was no clinical important between-group differences in terms of pain intensity (Mean Difference=0.01 point; 95% CI=-0.94 to 0.96) and disability (Mean Difference=-0.63 points; 95% CI=-2.23 to 0.97) at 4 weeks. Patients did not report any adverse events. Photobiomodulation therapy was not better than placebo to reduce pain and disability in patients with chronic non-specific low back pain.

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Differential alteration of fMRI signal variability in the ascending trigeminal somatosensory and pain modulatory pathways in migraine.

The moment-to-moment variability of resting-state brain activity has been suggested to play an active role in chronic pain. Here, we investigated the regional blood-oxygen-level-dependent signal variability (BOLD) and inter-regional dynamic functional connectivity (dFC) in the interictal phase of migraine and its relationship with the attack severity.

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Accelerated brain aging in chronic low back pain.

Chronic low back pain (CLBP) is a leading cause of disability and is associated with neurodegenerative changes in brain structure. These changes lead to impairments in cognitive function and are consistent with those seen in aging, suggesting an accelerated aging pattern. In this study we assessed this using machine-learning estimated brain age (BA) as a holistic metric of morphometric changes associated with aging. Structural imaging data from 31 non-depressed CLBP patients and 32 healthy controls from the Pain and Interoception Imaging Network were included. Using our previously developed algorithm, we estimated BA per individual based on grey matter density. We then conducted multivariable linear modeling for effects of group, chronological age, and their interaction on BA. We also performed two voxel-wise analyses comparing grey matter density between CLBP and control individuals and the association between gray matter density and BA. There was an interaction between CLBP and greater chronological age on BA such that the discrepancy in BA between healthy and CLBP individuals was greater for older individuals. In CLBP individuals, BA was not associated with sex, current level of pain, duration of CLBP, or mild to moderate depressive symptoms. CLBP individuals had lower cerebellar grey matter density compared to healthy individuals. Brain age was associated with lower gray matter density in numerous brain regions. CLBP was associated with greater BA, which was more profound in later life. BA as a holistic metric was sensitive to differences in gray matter density in numerous regions which eluded direct comparison between groups.

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Treatment benefit among migraine patients taking fremanezumab: results from a post hoc responder analysis of two placebo-controlled trials.

Monoclonal antibodies targeting the calcitonin gene-related peptide (CGRP) pathway, including the fully humanized monoclonal antibody (IgG2Δa) fremanezumab, have demonstrated safety and efficacy for migraine prevention. Clinical trials include responders and nonresponders; efficacy outcomes describe mean values across both groups and thus provide little insight into the clinical benefit in responders. Clinicians and their patients want to understand the extent of clinical improvement in patients who respond. This post hoc analysis of fremanezumab treatment attempts to answer this question: what is the benefit in subjects who responded to treatment during the two, phase 3 HALO clinical trials?

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Pruritus Intensity Scales across Europe: A Prospective Validation Study.

Chronic pruritus (CP) is a subjective symptom and it is necessary to assess its intensity with validated patient-reported outcome tools in order to allow determination of the treatment course.

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Prescription opioid misusers exhibit blunted parasympathetic regulation during inhibitory control challenge.

Among opioid-treated chronic pain patients, response inhibition deficits in emotional contexts may contribute to opioid misuse.

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The Importance of Perceived Relevance: A Qualitative Evaluation of Patient’s Perceptions of Value and Impact Following a Low-Intensity Group-Based Pain Management Program.

Limited evidence exists exploring perceptions of which aspects of a pain management program are perceived as valuable and impactful. The aim of this study was to explore patient beliefs about which aspects of a pain management program were valued and/or had perceived impact. One-on-one structured interviews were conducted with 11 adults three months after their completion of the Spark Pain Program at Westmead Hospital, Sydney, Australia. Concepts in the transcripts were inductively identified and explored, utilizing thematic analysis to better understand their relevance to the study aim. : Four themes emerged: (1) "The program overall was positive, but…"; (2) "I valued my improved knowledge and understanding of pain, but…"; (3) "I valued the stretching/relaxation/pacing/activity monitoring"; and (4) "I valued being part of a supportive and understanding group". Participants reported that they liked being treated as an individual within the group. A lack of perceived personal relevance of key messages was identified in some participants; it appears that patients in pain programs must determine that changes in knowledge, beliefs, and attitudes are personally relevant in order for the changes to have a significant impact on them. This study provides new insights into aspects of a pain management program that were perceived as valuable and impactful, areas that "missed the mark", and hypotheses to guide the implementation of service delivery and program redesign.

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The Combination of Preoperative Pain, Conditioned Pain Modulation, and Pain Catastrophizing Predicts Postoperative Pain 12 Months After Total Knee Arthroplasty.

Approximately 20% of knee osteoarthritis patients undergoing total knee arthroplasty (TKA) report chronic postoperative pain. Studies suggest that preoperative variables such as impaired descending pain control, catastrophizing, function, and neuropathic pain-like symptoms may predict postoperative pain 12 months after TKA, but the combined prediction value of these factors has not been tested. The current prospective cohort study aimed to combine preoperative risk factors to investigate the predictive value for postoperative pain 12 months after TKA.

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Paravertebral block for the prevention of chronic postsurgical pain after breast cancer surgery.

Patients frequently report chronic postsurgical pain (CPSP) after breast cancer surgery (BCS). The paravertebral block (PVB) is an effective technique to reduce acute postoperative pain after BCS, but its efficacy in preventing CPSP is unclear. This meta-analysis evaluates the efficacy of PVB in preventing CPSP after BCS. We searched Medline, Embase, CENTRAL, Database of Abstracts of Reviews of Effects, ClinicalTrials.gov, and WHO International Clinical Trials Registry Platform for studies comparing PVB with control for CPSP prevention after BCS, from inception to April 2020. The primary outcome was CPSP at 6 months, and the secondary outcomes were CPSP at 3 and 12 months, chronic postsurgical neuropathic pain (CPSNP) at 6 months, and PVB-related complications. Data were pooled and analyzed with a random-effects model, and the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) system was used to evaluate the certainty of evidence. A total of 12 studies were included in the study; data for the 6-month time point from 7 studies (2161 patients) were analyzed, and no difference was found between PVB and control in terms of efficacy in preventing CPSP after BCS (risk ratio (RR) 0.82 (95% CI 0.62 to 1.08)), with a moderate quality of evidence according to the GRADE system. Similar results were obtained at 3 and 12 months (RR 0.78 (95% CI 0.57 to 1.06), RR 0.45 (95% CI 0.14 to 1.41), respectively). Data for the 12-month time point from seven studies (2087 patients) were analyzed and showed that PVB protected against CPSNP, with low quality of evidence (RR 0.51 (95% CI 0.31 to 0.85)). In conclusion, CPSP was not found significantly prevented by PVB after BCS despite the limits in the included studies; nevertheless, PVB could prevent CPSNP by impacting the transition from acute to chronic pain.

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Protocol: mixed-methods study of how implementation of US state medical cannabis laws affects treatment of chronic non-cancer pain and adverse opioid outcomes.

Thirty-three US states and Washington, D.C., have enacted medical cannabis laws allowing patients with chronic non-cancer pain to use cannabis, when recommended by a physician, to manage their condition. However, clinical guidelines do not recommend cannabis for treatment of chronic non-cancer pain due to limited and mixed evidence of effectiveness. How state medical cannabis laws affect delivery of evidence-based treatment for chronic non-cancer pain is unclear. These laws could lead to substitution of cannabis in place of clinical guideline-discordant opioid prescribing, reducing risk of opioid use disorder and overdose. Conversely, state medical cannabis laws could lead to substitution of cannabis in place of guideline-concordant treatments such as topical analgesics or physical therapy. This protocol describes a mixed-methods study examining the implementation and effects of state medical cannabis laws on treatment of chronic non-cancer pain. A key contribution of the study is the examination of how variation in state medical cannabis laws' policy implementation rules affects receipt of chronic non-cancer pain treatments.

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