Pain
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Review Meta Analysis
Relationship between quantitative sensory testing and pain or disability in people with spinal pain-A systematic review and meta-analysis.
Sensitization of the nervous system can present as pain hypersensitivity that may contribute to clinical pain. In spinal pain, however, the relationship between sensory hypersensitivity and clinical pain remains unclear. This systematic review examined the relationship between pain sensitivity measured via quantitative sensory testing (QST) and self-reported pain or pain-related disability in people with spinal pain. ⋯ Fair correlations were found for the relationship between pain intensity and thermal temporal summation (0.26, 95% CI: 0.09 to 0.42) or pain tolerance (-0.30, 95% CI: -0.45 to -0.13), but only a few studies were available. Our study indicates either that pain threshold is a poor marker of central sensitization or that sensitization does not play a major role in patients' reporting of pain and disability. Future research prospects are discussed.
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Randomized Controlled Trial Multicenter Study
A phase 2, double-blind, randomized, placebo-controlled, dose-escalation study to evaluate the efficacy, safety, and tolerability of naloxegol in patients with opioid-induced constipation.
Naloxegol (previously known as NKTR-118) is a peripherally acting μ-opioid receptor antagonist engineered using polymer conjugate technology in development as an oral, once-daily agent for the treatment of opioid-induced constipation (OIC). Eligible patients with OIC (n=207), defined as <3 spontaneous bowel movements (SBMs) per week with accompanying symptoms, on a stable opioid regimen of 30-1000 mg/day morphine equivalents for ≥ 2 weeks were randomized to receive 4 weeks of double-blind placebo or naloxegol (5, 25, or 50mg) once daily in sequential cohorts after a 1-week placebo run-in. The primary end point, median change from baseline in SBMs per week after week 1 of drug administration, was statistically significant for the 25- and 50-mg naloxegol cohorts vs placebo (2.9 vs 1.0 [P=0.0020] and 3.3 vs 0.5 [P=0.0001], respectively). ⋯ Similar AEs occurred with increased frequency and severity in the 50-mg cohort. There was no evidence of a statistically significant increase from baseline in pain, opioid use for the 25- and 50-mg cohorts, or centrally mediated opioid withdrawal signs and/or symptoms with naloxegol. These data demonstrate that once-daily oral naloxegol improves the frequency of SBMs compared with placebo and is generally well tolerated in this population of patients with OIC.
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In patients with complex regional pain syndrome (CRPS) type 1, processing of static tactile stimuli is impaired, whereas more complex sensory integration functions appear preserved. This study investigated higher order multisensory integration of body-relevant stimuli using the rubber hand illusion in CRPS patients. Subjective self-reports and skin conductance responses to watching the rubber hand being harmed were compared among CRPS patients (N=24), patients with upper limb pain of other origin (N=21, clinical control group), and healthy subjects (N=24). ⋯ However, patients with CRPS of the right hand reported significantly stronger neglect-like symptoms and significantly lower illusion strength of the affected hand than patients with CRPS of the left hand. The weaker illusion of CRPS patients with strong neglect-like symptoms on the affected hand supports the role of top-down processes modulating body ownership. Moreover, the intact ability to perceive illusory ownership confirms the notion that, despite impaired processing of proprioceptive or tactile input, higher order multisensory integration is unaffected in CRPS.