Articles: hyperalgesia.
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To investigate allodynia in patients with different primary headaches. ⋯ Allodynia is not specific to migraine but is frequent in all headache patients: acute allodynia was reported in half those interviewed and in over a third of patients in each headache category; interictal allodynia was reported by nearly 25%.
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Electrical stimulation is widely used to assess the function of sensory nerves in humans. In the present study, the threshold current (CT) required to evoke a paw withdrawal response in rats was assessed with stepwise increases in current delivered as sinusoidal stimulation at frequencies of 2000 Hz (CT2000), 250 Hz (CT250) and 5 Hz (CT5). Baseline CT was 840+/-3 microA for CT2000, 267+/-2 microA for CT250 and 165+/-1 microA for CT5 (n=59). ⋯ Intraperitoneal pretreatment with indomethacin (20mg/kg) attenuated carrageenan evoked CT alterations as well as progression of paw swelling and thermal hyperalgesia. In conclusion, low, but not high, frequency stimulation activated a withdrawal response which appears mediated by morphine and capsaicin sensitive primary afferents and this threshold was reduced in the presence of inflammation. These data suggest the validity of such stimulation in defining drug action in a nontissue injurious fashion.
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Brain Behav. Immun. · Feb 2008
IL-1 beta signaling is required for mechanical allodynia induced by nerve injury and for the ensuing reduction in spinal cord neuronal GRK2.
Many neurotransmitters involved in pain perception transmit signals via G protein-coupled receptors (GPCRs). GPCR kinase 2 (GRK2) regulates agonist-induced desensitization and signaling of multiple GPCRs and interacts with downstream molecules with consequences for signaling. In general, low GRK2 levels are associated with increased responses to agonist stimulation of GPCRs. ⋯ Moreover, spinal cord GRK2 expression was not decreased in IL-1R(-/-) mice after L5 SNT. These data show that IL-1 beta signaling is not only required for the development of mechanical allodynia, but also to reduce neuronal GRK2 expression. These results suggest a functional relation between the L5 SNT-induced IL-1 beta-mediated decrease in GRK2 and development of mechanical allodynia.
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The platinum derivative oxaliplatin is widely used in colorectal cancer. Its side effects differ from those of the other platinum compounds cisplatin and carboplatin. ⋯ It is believed that HES is the result of peripheral nerve hyperexcitability as a consequence of voltage-gated sodium channel dysfunction, which may be caused by calcium level imbalance. Therapeutic options for HES are the administration of calcium and magnesium, the serotonin and noradrenaline reuptake inhibitor (SNRI) venlafaxine and the thiophosphate amifostine.
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Anesthesia and analgesia · Feb 2008
Case ReportsOpioid-induced hyperalgesia and rapid opioid detoxification after tacrolimus administration.
Opioids can induce central sensitization and hyperalgesia, referred to as "opioid-induced hyperalgesia." Our report describes a patient who underwent intestinal transplant followed by immunosuppressant-related neuropathic pain. Her pain was treated with limited success over the course of 3 yr with different therapies, including i.v. morphine. ⋯ Six months after treatment, she remained opioid free. Our experience suggests that rapid detoxification under general anesthesia may be an effective treatment for opioid-induced hyperalgesia and merits comparison to traditional detoxification methods.