Pain
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The nociceptin/orphanin FQ peptide receptor (NOP), activated by its endogenous peptide ligand nociceptin/orphanin FQ (N/OFQ), exerts several effects including modulation of pain signalling. We have examined, for the first time, the tissue distribution of the NOP receptor in clinical visceral and somatic pain disorders by immunohistochemistry and assessed functional effects of NOP and μ-opioid receptor activation in cultured human and rat dorsal root ganglion (DRG) neurons. Quantification of NOP-positive nerve fibres within the bladder suburothelium revealed a remarkable several-fold increase in detrusor overactivity (P < 0.0001) and painful bladder syndrome patient specimens (P = 0.0014) compared with controls. ⋯ The maximum inhibition of capsaicin responses was greater with N/OFQ than μ-opioid receptor agonist DAMGO. Our findings highlight the potential of NOP agonists, particularly in urinary bladder overactivity and pain syndromes. The regulation of NOP expression in visceral and somatic sensory neurons by target-derived neurotrophic factors deserves further study, and the efficacy of NOP selective agonists in clinical trials.
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Randomized Controlled Trial Multicenter Study
Ultramicronized palmitoylethanolamide in spinal cord injury neuropathic pain: A randomized, double-blind, placebo-controlled trial.
Neuropathic pain and spasticity after spinal cord injury (SCI) represent significant problems. Palmitoylethanolamide (PEA), a fatty acid amide that is produced in many cells in the body, is thought to potentiate the action of endocannabinoids and to reduce pain and inflammation. This randomized, double-blind, placebo-controlled, parallel multicenter study was performed to investigate the effect of ultramicronized PEA (PEA-um) as add-on therapy on neuropathic pain in individuals with SCI. ⋯ There was no difference in mean pain intensity between PEA-um and placebo treatment (P = 0.46, mean reductions in pain scores 0.4 (-0.1 to 0.9) vs 0.7 (0.2-1.2); difference of means 0.3 (-0.4 to 0.9)). There was also no effect of PEA-um as add-on therapy on spasticity, insomnia, or psychological functioning. PEA was not associated with more adverse effects than placebo.
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Multicenter Study
The reciprocal associations between catastrophizing and pain outcomes in patients being treated for neuropathic pain: a cross-lagged panel analysis study.
Catastrophizing is recognized as a key psychosocial factor associated with pain-related negative outcomes in individuals with chronic pain. Longitudinal studies are needed to better understand the temporal relationship between these constructs. The aim of this study was to determine if changes in catastrophizing early in treatment predicted subsequent changes in pain intensity and interference later in treatment, or alternately, if early changes in pain intensity and interference predicted subsequent changes in catastrophizing. ⋯ The findings are consistent with theoretical models hypothesizing a causal impact of catastrophizing on pain, suggesting a mutual causation between these factors. The results support that treatments targeting catastrophizing may influence other pain-related outcomes, and conversely that treatments aiming to reduce pain could potentially influence catastrophizing. There may therefore be multiple paths to positive outcomes.
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Anticipatory distress prior to a painful medical procedure can lead to negative sequelae including heightened pain experiences, avoidance of future medical procedures, and potential noncompliance with preventative health care, such as vaccinations. Few studies have examined the longitudinal and concurrent predictors of pain-related anticipatory distress. This article consists of 2 companion studies to examine both the longitudinal factors from infancy as well as concurrent factors from preschool that predict pain-related anticipatory distress at the preschool age. ⋯ Parental behaviours from infancy and preschool were the strongest predictors of child anticipatory distress at preschool. Child age positively predicted child anticipatory distress. This strongly suggests that the involvement of parents in pain management interventions during immunization is one of the most critical factors in predicting anticipatory distress to the preschool vaccination.
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The pediatric adaptation of the Collaborative Health Outcomes Information Registry (Peds-CHOIR) is a free, open-source, flexible learning health care system (LHS) that meets the call by the Institute of Medicine for the development of national registries to guide research and precision pain medicine. This report is a technical account of the first application of Peds-CHOIR with 3 aims: (1) to describe the design and implementation process of the LHS; (2) to highlight how the clinical system concurrently cultivates a research platform rich in breadth (eg, clinic characteristics) and depth (eg, unique patient- and caregiver-reporting patterns); and (3) to demonstrate the utility of capturing patient-caregiver dyad data in real time, with dynamic outcomes tracking that informs clinical decisions and delivery of treatments. Technical, financial, and systems-based considerations of Peds-CHOIR are discussed. ⋯ Patients and caregivers evidenced agreement in observable variables (mobility); however, caregivers consistently endorsed greater impairment regarding internal experiences (pain interference, fatigue, peer relations, anxiety, and depression) than patients' self-report. A platform like Peds-CHOIR highlights predictors of chronic pain outcomes on a group level and facilitates individually tailored treatment(s). Challenges of implementation and future directions are discussed.