Pain
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Little is known about the relationship between chronic pain status and overall use of healthcare. We examined whether disabling chronic pain was associated with more frequent use of healthcare in three settings: primary care, emergency departments, and hospital admissions. We used data from Computer-Assisted Telephone Interviews (CATI) of 17,543 residents in New South Wales, Australia aged 16 and over who were randomly sampled using a population-based two-stage stratified sample and random digit dialing methods. ⋯ There was a strong association between pain-related disability and greater use of services. Further work is needed to understand the nature of this association. Given the fluctuating course of chronic pain over time, there is a significant segment of the population that may be at risk of developing higher levels of disability associated with increased use of services.
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A patient's readiness to adopt a self-management approach to pain has been hypothesized to increase during multidisciplinary pain treatment and to impact pain coping responses. The Pain Stages of Change Questionnaire (PSOCQ; [J Pain (1997) 227]) was designed to assess four components of readiness to self-manage pain: pre-contemplation, contemplation, action, and maintenance. ⋯ The findings supported all three hypotheses. We discuss the implications of the findings for understanding motivational issues in the self-management of pain.
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This study describes suicidal behavior in a cross-sectional sample of chronic pain patients and evaluates factors associated with increased risk for suicidal ideation. One hundred-fifty-three adults with nonmalignant pain (42% back pain) who were consecutively referred to a tertiary care pain center completed a Structured Clinical Interview for Suicide History, the McGill Pain Questionnaire, and the Beck Depression Inventory. Nineteen-percent reported current passive suicidal ideation (PSI), 13% had active thoughts of committing suicide (ASI), 5% had a current suicide plan, and 5% reported a previous suicide attempt. ⋯ Neuropathic pain significantly reduced risk for both PSI (P=0.002) and ASI (P=0.01). Demographics, pain severity, and depression severity were not associated with suicidal ideation in multivariate analyses. These findings highlight the need for routine evaluation and monitoring of suicidal behavior in chronic pain, especially for patients with family histories of suicide, those taking potentially lethal medications, and patients with abdominal pain.
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N-methyl-D-aspartate (NMDA) receptors serve prominent roles in vast physio-pathological conditions including hyperalgesia (defined as augmented pain intensity in response to painful stimuli) associated with central sensitization. Using M40403 a synthetic low molecular weight superoxide dismutase mimetic that removes superoxide we show for the first time that this radical plays a key role in NMDA-mediated hyperalgesia. Intrathecal administration of NMDA in rats led to a time-dependent development of thermal hyperalgesia. ⋯ M40403 by preventing MnSOD nitration restored its activity and inhibited the hyperalgesic response to intrathecal NMDA. Thus, superoxide-mediated nitration and deactivation of spinal MnSOD is a novel pathway of NMDA-mediated spinal hyperalgesia and hence central sensitization since it helps to maintain high levels of superoxide that in turn maintains nociceptive signaling. The broader implication of our findings is that superoxide may contribute to various forms of pain events that are driven by NMDA-receptor activation.
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Peripheral nerve injury leads to structural and functional changes in the spinal dorsal horn, and these are thought to be involved in the development of neuropathic pain. In the chronic constriction injury (CCI) model, abnormal 'dark' neurons and apoptotic nuclei have been observed in laminae I-III of the dorsal horn in the territory innervated by the injured sciatic nerve. These findings have been taken as evidence that there is significant neuronal death in this model, and it has been suggested that loss of inhibition resulting from death of GABAergic inhibitory interneurons contributes to the neuropathic pain. ⋯ All of the CCI animals showed clear signs of thermal hyperalgesia. However, the numbers of neurons in laminae I-III of the ipsilateral dorsal horn in these animals did not differ significantly from those on the contralateral side, nor from those of sham-operated or naïve animals. These results do not, therefore, support the suggestion that there is significant neuronal death in the dorsal horn in this model.