The Clinical journal of pain
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Pain catastrophizing, an excessively negative cognitive and emotional orientation toward pain, is one of the most important psychological determinants of the individual pain experience. The neural basis of the association between catastrophizing and enhanced pain perception is only incompletely understood. Recently, several forms of pain modulation by cognitive and emotional factors have been found to at least partly rely on descending pain modulatory pathways that govern spinal gating mechanisms. We used the spinally mediated nociceptive flexor reflex (RIII reflex) to investigate whether spinal nociceptive transmission is affected when participants engage in catastrophizing self-statements. ⋯ The results of present study suggest that the effect of catastrophizing self-statements on pain is predominantly supraspinal, with a smaller but significant contribution from descending pathways. In addition, catastrophizing self-statements seem to predominantly affect mechanisms involved in the processing of single nociceptive stimuli, not their temporal summation.
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The purpose of this study was to establish if people with chronic low back pain (CLBP) demonstrate impairments in the ability to localize sensory information delivered to the back more than pain-free controls and determine whether any sensory abnormalities are related to pain-related variables. ⋯ These data add to a growing body of evidence suggesting that disturbed self-perception is a feature of CLBP. It is plausible that altered self-perception is maladaptive and contributes to the maintenance of the problem and may represent a target of treatment for CLBP.
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Randomized Controlled Trial
Postoperative analgesic effect of transcranial direct current stimulation in lumbar spine surgery: a randomized control trial.
Ultimately, the experience of pain derives from changes in brain excitability. Therefore, modulating the excitability of cortical areas involved in pain processing may become an attractive option in the context of multimodal analgesia during the postoperative period. Repetitive transcranial magnetic stimulation (rTMS) can reduce morphine consumption during the postoperative period after gastric bypass surgery. We tested the potential of another method of noninvasive brain stimulation, transcranial direct current stimulation (tDCS), to reduce morphine consumption or pain perception during the postoperative period. ⋯ Several factors may explain the observed lack of impact of tDCS on PCA morphine consumption and pain perception: the method of brain stimulation (tDCS/rTMS), potential interactions with anesthetic drugs, differences in patients population (gastric bypass surgery/lumbar spine surgery), and the previous experience of pain and chronic consumption of analgesic drugs. Further studies with tDCS should be performed before concluding that tDCS is inefficient for postoperative pain control, because noninvasive brain stimulation methods, such as rTMS and tDCS, may become attractive in the setting of multimodal analgesia.
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Randomized Controlled Trial
Bowel function after tapentadol and oxycodone immediate release (IR) treatment in patients with low back or osteoarthritis pain.
Constipation is a common side effect of opioid therapy. Tapentadol immediate release (IR) was better tolerated than oxycodone IR in 2 clinical trials involving patients with low back or osteoarthritis pain. The objective of this study was to examine patient-reported bowel function during those trials. ⋯ Patient-reported bowel function associated with tapentadol IR treatment was similar to that associated with placebo (10-d trial) and significantly better than that associated with oxycodone IR treatment (10- and 90-d trials).
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Widespread central hypersensitivity and altered conditioned pain modulation (CPM) have been documented in chronic pain conditions. Information on their prognostic values is limited. This study tested the hypothesis that widespread central hypersensitivity (WCH) and altered CPM, assessed during the chronic phase of low back and neck pain, predict poor outcome. ⋯ A major predictive value of the measures that we used is unlikely. Future studies adopting other assessment modalities and possibly standardized treatments are needed to further elucidate the prognostic value of WCH and altered CPM in chronic pain.