The Clinical journal of pain
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There has been increased recognition of calcineurin, a phosphoprotein serine/threonine phosphatase enzyme, in the regulation of many physiologic systems. Calcineurin mediates activation of lymphocytes, which play a role in immune response. Widely distributed in the central nervous system, calcinuerin also plays an important role in sensory neural function, via its role in the regulation of newly discovered 2-pore potassium channels, which greatly influence neuronal resting membrane potentials. Calcinuerin inhibition is the mechanism of action of immunomodulatory drugs such as cyclosporine and tacrolimus, which are widely used in transplantation medicine to prevent rejection. While important for immunosuppression, the use of calcineurin inhibitors has been associated with the development of a new pain syndrome called the calcineurin pain syndrome, which appears to be an untoward complication of the interruption of the physiologic function of calcineurin. ⋯ The calcineurin syndrome is a newly recognized complication associated with the use of calcineurin inhibitors. There is no standard therapy at this time but anecdotal reports suggest the effectiveness of calcium channel blockers.
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Comparative Study
Comparing pain modulation and autonomic responses in fibromyalgia and irritable bowel syndrome patients.
Past studies confirm that patients with fibromyalgia (FM) and irritable bowel syndrome (IBS) show similar pain processing dysfunctions, such as reduced pain inhibition and aberrant autonomic nervous system (ANS) responses. However, patients with FM and IBS have rarely been investigated in the same study. The aim of the present study, therefore, was to compare descending pain inhibition, pain sensitivity, and ANS reactivity to pain in FM, IBS, and healthy controls (HC). ⋯ Our results confirm the presence of graded levels of somatic hyperalgesia across patients with IBS and FM. A similar pattern of result was observed for pain inhibitory dysfunctions. These pain processing changes were accompanied by abnormal autonomic responses, which maintained patients (principally patients with FM) in a state of sympathetic hyperactivity. Results suggest that patients with IBS and FM may present common, but graded, pain processing and autonomic dysfunctions.
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Anxiety sensitivity (AS) is the fear of anxiety-related sensations and its perceived harmful consequences. AS is associated with enhanced pain and worsened pain outcomes, suggesting it is a contributing factor in acute and chronic pain. However, the mechanisms that mediate the relationship between AS and pain are currently unknown. This study assessed the relationship between AS and 2 measures of spinal nociceptive processes (ie, nociceptive flexion reflex and temporal summation of nociceptive flexion reflex) and measures of subjective pain. This allowed us to determine whether AS engages descending cerebrospinal processes to facilitate pain signaling at spinal levels. ⋯ Given that AS was not significantly associated with measures of spinal nociception, these results suggest that AS may exert its influence on pain processing at the supraspinal, rather than the spinal level.
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The fear-avoidance (FA) model of chronic pain describes how individuals experiencing acute pain may become trapped into a vicious circle of chronic disability and suffering. We propose to extend the FA model by adopting a motivational perspective on chronic pain and disability. ⋯ To address these 3 key challenges, we argue that the next generation of the FA model needs to more explicitly adopt a motivational perspective, one that is built around the organizing powers of goals and self-regulatory processes. Using this framework, the FA model is recast as capturing the persistent but futile attempts to solve pain-related problems to protect and restore life goals.
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Randomized Controlled Trial Multicenter Study
Is botulinum toxin A effective for the treatment of plantar fasciitis?
Botulinum toxin A (BoNT-A) is used as an alternative treatment for chronic orthopedic conditions. This study was conducted to investigate the efficacy and safety of BoNT-A on pain and functional outcome in patients with chronic plantar fasciitis. ⋯ There is a need for larger, prospective, long-term, placebo-controlled studies to fully establish the role of BoNT-A for the treatment of plantar fasciitis.