The journal of pain : official journal of the American Pain Society
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Optimism is associated with lower pain sensitivity, positive adjustment to chronic pain, and greater reduction of pain thresholds in a conditioned pain modulation (CPM) paradigm. We hypothesized that participants with higher levels of optimism would experience greater inhibition of suprathreshold pain during CPM. Seventy-seven healthy adults completed a test of optimism, the Life Orientation Test-Revised, as well as measures of depression, pain catastrophizing, and neuroticism. ⋯ This unexpected finding may be due to factors such as perceived stress and coping differences, and suggests that modulation of threshold-level and suprathreshold pain involves different underlying mechanisms. PERSPECTIVE: This article reports that greater optimism predicts less inhibition of suprathreshold pain, in contrast with previous work showing that optimism correlates positively with pain threshold reductions. These findings suggest that the association between optimism and the function of endogenous pain modulatory systems is complex and differs for threshold-level and suprathreshold pain.
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We showed previously that spinal metabotropic glutamate receptor 1 (mGluR1) signaling suppresses or facilitates (depending on the stage of estrous cycle) analgesic responsiveness to intrathecal endomorphin 2, a highly mu-opioid receptor-selective endogenous opioid. Spinal endomorphin 2 antinociception is suppressed during diestrus by mGluR1 when it is activated by membrane estrogen receptor alpha (mERα) and is facilitated during proestrus when mGluR1 is activated by glutamate. In the current study, we tested the hypothesis that in female rats subjected to spinal nerve ligation (SNL), the inhibition of spinal estrogen synthesis or blockade of spinal mERα/mGluR1 would be antiallodynic during diestrus, whereas during proestrus, mGluR1 blockade would worsen the mechanical allodynia. ⋯ Findings suggest menstrual cycle stage-specific drug targets for and the putative clinical utility of harnessing endogenous opioids for chronic pain management in women, as well as the value of, if not the necessity for, considering menstrual cycle stage in clinical trials thereof. PERSPECTIVE: Intrathecal treatments that enhance spinal endomorphin 2 analgesic responsiveness under basal conditions lessen mechanical allodynia in a chronic pain model. Findings provide a foundation for developing drugs that harness endogenous opioid antinociception for chronic pain relief, lessening the need for exogenous opioids and thus prescription opioid abuse.
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Review Meta Analysis
Do People With Chronic Musculoskeletal Pain Have Impaired Motor Imagery? A Meta-analytical Systematic Review of the Left/Right Judgment Task.
The left/right judgment task (LRJT) is the most commonly used method of assessing motor imagery performance. Abnormally long response times are thought to reflect delayed processing of body/spatial representations, and poor accuracy is thought to reflect disrupted cortical proprioceptive representations or body schema. Slower and less accurate responses on the LRJT have been reported in a variety of chronic musculoskeletal pain conditions. ⋯ PERSPECTIVES: This review synthesizes evidence of altered motor imagery performance using the LRJT across chronic musculoskeletal pain conditions. Consistent evidence was found for altered motor imagery performance in peripheral pain conditions, but evidence was less consistent for axial conditions. Treatment to restore a normal body schema may be beneficial in chronic limb and facial pain.
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Despite widespread use as a chronic pain management strategy, pacing has been linked with higher levels of pain and disability. A recent meta-analysis found a positive correlation between existing measures of pacing and avoidance, which may partially account for these poorer outcomes. A measure was developed to differentiate pacing from avoidance by emphasizing non-pain-contingent pacing behaviors and nonavoidance of pain. ⋯ PERSPECTIVE: The NAPS assesses activity pacing in chronic pain without artefactual overlap with avoidance. Associations were found between more frequent pacing, as measured by the NAPS, and better psychological functioning. Clearly differentiating pacing from avoidance allows for accurate assessment of the role of pacing in chronic pain management.
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Observational Study
SELF-MEDICATION WITH OVER-THE-COUNTER ANALGESICS: A SURVEY OF PATIENT CHARACTERISTICS AND CONCERNS ABOUT PAIN MEDICATION.
Pain is a common reason for self-medication with over-the-counter (OTC) analgesics. However, this self-treating population has remained largely uncharacterized. This cross-sectional observational study investigated individuals who self-medicate their pain with OTC analgesics to elucidate their pain characteristics and medication use. ⋯ Perspective: This study found that the clinical picture of people who self-medicate their pain with OTC analgesics looked worse than expected. We also identified substantial concerns about pain medication. Therefore, we recommend that health professionals systematically probe pain patients about their self-medication practices and explore concerns about pain medication.