Articles: hyperalgesia.
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Accumulating evidence suggests that opioid analgesics can lead to paradoxical sensitization to pain when delivered in different administration patterns. Although opioid tolerance-induced hyperalgesia is largely studied, little is known about the mechanisms underlying acute ultra-low-dose morphine hyperalgesia. Activation of spinal glial cells is reported to regulate pain hypersensitivity. ⋯ Immunofluorescence experiments indicated the neuronal localization of spinal MOR. However, JNK was not detected in MOR-expressing cells, showing the presence of a neuron-astrocyte signaling pathway. These results illustrate the selective activation of an astrocyte JNK pathway after the stimulation of neuronal MOR, which contributes to ultra-low-dose morphine hyperalgesia.
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Anesthesia and analgesia · Jul 2015
Treadmill Training Combined with Insulin Suppresses Diabetic Nerve Pain and Cytokines in Rat Sciatic Nerve.
Insulin therapy plays a critical role in managing type 1 diabetes mellitus, and exercise produces alterations in pain sensation. This experiment explored the effects of insulin therapy combined with treadmill training on diabetic neuropathic pain and on the expression of malondialdehyde (MDA) and cytokines. ⋯ Treadmill training combined with insulin therapy showed the best improvements in tactile allodynia and thermal hyperalgesia among our 3 treatment groups. The benefits of insulin intervention and treadmill training could be related to chronic inflammation (proinflammatory cytokines) and oxidative stress (MDA).
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J Obstet Gynaecol Can · Jul 2015
Case ReportsThe Significance of Cutaneous Allodynia in a Woman With Chronic Pelvic Pain.
This is a case report of sensory assessment in a woman with severe chronic pelvic pain following uterine artery embolization, and a discussion of a commonly observed sensory manifestation (allodynia) associated with chronic pelvic pain due to gynaecological conditions. Allodynia, as a common sensory abnormality can be readily detected at the bedside and represents the development of pain sensitization. Emergence of abdominal and perineal allodynia (assessed by cotton swap stroking and/or questionnaire) is associated with the development of the clinical features of sensitization: continuous pelvic pain, muscle tenderness, and reduced pressure pain thresholds. ⋯ Testing for allodynia is a validated bedside test for pain sensitization. A clinical trial of botulinum toxin is indicated for the management of chronic pelvic pain associated with allodynia and pain sensitization.
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Anesthesia and analgesia · Jul 2015
The Effects of Intraplantar and Intrathecal Botulinum Toxin Type B on Tactile Allodynia in Mono and Polyneuropathy in the Mouse.
Mononeuropathies (MNs: nerve ligation) and polyneuropathies (PNs: cisplatin) produce unilateral and bilateral tactile allodynia, respectively. We examined the effects of intraplantar (IPLT) and intrathecal (IT) botulinum toxin B (BoNT-B) on this allodynia. ⋯ BoNT-B given IPLT and IT yields a long-lasting attenuation of the allodynia in mice displaying MN and PN allodynia.
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Ambiguous visual stimuli increase limb pain in patients with complex regional pain syndrome (CRPS), possibly due to afferent sensory feedback conflicts. Conflicting sensory stimuli can also generate unpleasant sensations in healthy people such as during motion sickness. We wanted to investigate the mechanisms underlying the link between sensory conflicts and pain in CRPS using optokinetic stimulation (OKS) - a method known to induce motion sickness. ⋯ Sensory conflicts may facilitate pain in CRPS by activating the mechanisms of general facilitation of nociception and, during more severe sensory conflicts, also a facilitatory mechanism that operates mainly ipsilateral to the affected limb.