Articles: hyperalgesia.
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Neonatal pain and inflammation may lead to a long-term effect on nociceptive processing in adults. The current study examined the characteristics of postoperative incisional pain behaviors in adult rats that were subjected to neonatal peripheral inflammation. ⋯ The authors' results suggest that early inflammatory insults during the neonatal period could produce excessive incision-associated mechanical pain hypersensitivity in adult rats. Spinal cord N-methyl-D-aspartate receptors and downstream nitric oxide signaling might contribute to this abnormal pain hypersensitivity, although the mechanisms underlying the long-term effect of neonatal inflammation are still unclear.
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Acta Anaesthesiol Taiwan · Jun 2007
Effect of intrathecal NG-nitro-L-arginine methyl ester administration on Fos expression in the spinal dorsal horn in rats following sciatic nerve ligation.
In the available literature, the pro- or antinociceptive role of nitric oxide (NO) is warmly disputed. As a marker of neuronal activation of the central nervous system, Fos expression has been widely used to assess the change in central neuronal activity evoked by peripheral input. In this study, we examined the effect of intrathecal L-NAME, a non-selective nitric oxide synthase (NOS) inhibitor, on nociceptive behavior and spinal Fos expression in rats following chronic constriction injury (CCI) of sciatic nerve, a model of neuropathic pain similar to that observed in clinical setting. ⋯ Spinal Fos expression could be induced by different mechanisms, and it should not regarded as a reliable marker of pain sensation disorders. NO plays an important role in the development of nociception and spinal Fos expression through central sensitization mediated by peripheral nerve injury.
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Clinical Trial
Dihydroergotamine for early and late treatment of migraine with cutaneous allodynia: an open-label pilot trial.
To explore whether dihydroergotamine (D.H.E. 45) is equally effective and safe for migraine with allodynia, when administered either early or late in an attack. ⋯ The results of this pilot trial provide proof of concept for the headache-relief benefit of dihydroergotamine in patients with migraine headache and allodynia. A large, placebo-controlled trial of dihydroergotamine in allodynic patients is warranted.
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Neuropathic pain is associated with significant co-morbidity, including anxiety and depression, which impact considerably on the overall patient experience. However, pain co-morbidity symptoms are rarely assessed in animal models of neuropathic pain. To improve the clinical validity of a widely used rodent model of traumatic peripheral neuropathy, we have investigated fear-avoidance- and depression-related behaviours in nerve-injured and sham-operated mice over a 4 week period. ⋯ These data demonstrate that pain behaviour in nerve-injured C57BL/6J mice was not associated with alterations in emotion-related behaviours.
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Anesthesia and analgesia · Jun 2007
Randomized Controlled Trial Comparative StudyModulation of remifentanil-induced postinfusion hyperalgesia by propofol.
Experimental and clinical studies suggest that brief opioid exposure can enhance pain sensitivity. During anesthesia, however, opioids are commonly administered in combination with either IV or inhaled hypnotic drugs. In this investigation we sought to determine the analgesic and antihyperalgesic properties of propofol in subhypnotic concentrations on remifentanil-induced postinfusion hypersensitivity in an experimental human pain model. ⋯ The results suggest clinically relevant interactions of propofol and remifentanil in humans, since propofol led to a delay and a weakening of remifentanil-induced postinfusion anti-analgesia in humans. Nevertheless, pronociceptive effects were not completely antagonized by propofol, which may account for the increased demand for analgesics after remifentanil-based anesthesia in clinical practice.