Articles: hyperalgesia.
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Anesthesia and analgesia · Jun 2015
Mitigation of Experimental, Chronic Post-Thoracotomy Pain by Preoperative Infiltration of Local Slow-Release Bupivacaine Microspheres.
Postoperative pain is treated incompletely and ineffectively in many circumstances, and chronic postoperative pain causes suffering and diminishes productivity. The objective of this project is to determine whether a recently developed slow-release formulation of bupivacaine was effective in reducing the experimental chronic postoperative pain. ⋯ Local slow release of bupivacaine subcutaneously from the MS-Bupi formulation suppresses postoperative mechanical hypersensitivity for ≥4 weeks after experimental thoracotomy. Systemic bupivacaine from this treatment has no effect on this hypersensitivity.
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Patients receiving chronic opioid treatment who develop paradoxical pain sensations, as well as worsening existing pain, can be diagnosed as suffering from opioid-induced hyperalgesia (OIH). As the worldwide population expands so too does the proportion of patients who experience pain that requires a strong opioid. Recognizing the symptoms of OIH and optimizing the use of morphine in the hospital setting is imperative. This review focuses on clinical data relating to evidence of OIH at the bedside and the novel techniques employed by healthcare providers in order to improve the heightened pain sensations experienced by susceptible patients. ⋯ Looking to the future, improved clinician-patient communication, advanced diagnostic techniques and a refinement of prescribed adjunct pharmacotherapies will offer the most successful multimodal pain management approach to the problem of OIH.
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Between attacks, migraine is associated with hypersensitivities to sensory stimuli. The objective of this study was to investigate hypersensitivity to pain in migraineurs between attacks. ⋯ This study provides evidence that migraineurs have low heat pain thresholds between migraine attacks. Mechanisms underlying these lower pain thresholds could also predispose migraineurs to their next migraine attack, a hypothesis supported by finding positive correlations between pain thresholds and time to next migraine attack.
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Neurochemical research · Jun 2015
Upregulation of α₂δ-1 Calcium Channel Subunit in the Spinal Cord Contributes to Pelvic Organ Cross-Sensitization in a Rat Model of Experimentally-Induced Endometriosis.
Pelvic organ cross-sensitization, also termed as viscero-visceral referred hyperalgesia, is a major contributor to painful endometriosis. Its underlying mechanism is poorly understood. Clinical and basic studies have shown that gabapentin, a drug that binds to the α2δ-1 subunit of voltage-dependent calcium channels (Cavα2δ-1), is effective in treating chronic visceral pain. ⋯ Furthermore, intrathecal injection of Cavα2δ-1 antisense oligodeoxynucleotides reversed the ectopic growths-to-colon cross-sensitization and also normalized the upregulation of spinal Cavα2δ-1 expression in endometriosis rats. The current study suggests that the upregulation of Cavα2δ-1 in the spinal cord may contribute to pelvic organ cross-sensitization in painful endometriosis. Our study may provide a biological basis for selectively targeting this pathway to relieve viscero-visceral referred hyperalgesia in patients with painful endometriosis.
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Neuroscience research · Jun 2015
Modulation of spinal glial reactivity by intrathecal PPF is not sufficient to inhibit mechanical allodynia induced by nerve crush.
Spinal glial reactivity has been strongly implicated in pain that follows peripheral nerve injury. Among the many therapeutic agents that have been tested for anti-allodynia through immune modulation is the atypical methylxanthine propentofylline. ⋯ Microglial/macrophage Iba-1 and astrocytic GFAP expression, increased in the dorsal horn of nerve crushed animals, was, however, effectively attenuated by propentofylline. Effective modulation of spinal glial reactivity is, thus, no assurance for anti-allodynia.