Articles: hyperalgesia.
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Anesthesia and analgesia · Aug 2011
Randomized Controlled TrialMagnesium sulfate prevents remifentanil-induced postoperative hyperalgesia in patients undergoing thyroidectomy.
In a randomized, double-blind, prospective study, we investigated whether an intraoperative high versus low dose of remifentanil increased postoperative hyperalgesia and whether magnesium can prevent remifentanil-induced hyperalgesia. ⋯ A relatively high dose of intraoperative remifentanil enhances periincisional hyperalgesia. Intraoperative MgSO(4) prevents remifentanil-induced hyperalgesia. However, hyperalgesia did not reach clinical relevance in terms of postoperative pain or analgesic consumption in patients undergoing thyroidectomy.
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Physiother Theory Pract · Aug 2011
Case ReportsResolution of whiplash-associated allodynia following cervicothoracic thrust and non-thrust manipulation.
Whiplash injuries of the cervical spine comprise 30% of injuries reported following motor vehicle accident (MVA) and often progress to chronic painful conditions. The purpose of this case report is to describe the management of a 37-year-old female referred to physical therapy with neck and shoulder pain after whiplash injury. The patient demonstrated limited cervical and shoulder active range of motion as well as quantitative sensory testing (QST) results consistent with central nervous system sensitization. ⋯ Her Copenhagen Neck Functional Disability Scale decreased from 23/30 to 4/30 by the 11th visit. In addition, she demonstrated clinically significant increases in cervical active range of motion and normal somatosensation. Manual therapy of the cervicothoracic spine may be a beneficial adjunct to the standard care of patients with signs and symptoms of central sensitization after whiplash-associated disorder and primary report of neck and shoulder pain.
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Trigeminal neuropathic pain is due to lesion or dysfunction of the nervous system. Dynamic mechanical allodynia is a widespread symptom of neuropathic pain for which mechanisms are still poorly understood. Recent studies demonstrate that forebrain neurons, including neurons in the medial prefrontal cortex (mPFC) are important for the perception of acute and chronic pain. ⋯ Stimulus-evoked pERK-1/2 immunopositive cell bodies displayed a rostrocaudal gradient and layer-selective distribution in the ventral mPFC, being predominant in the rostral ventral mPFC and in layers II-III and V-VI of the ventral mPFC. In layers II-III, intense pERK-1/2 also extended into distal dendrites, up to layer I. These results demonstrate that trigeminal nerve injury induces a significant alteration in the ventral mPFC processing of tactile stimuli and suggest that ERK phosphorylation contributes to the mechanisms underlying abnormal pain perception under this condition.
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Anesthesia and analgesia · Aug 2011
The macrophage-mediated effects of the peroxisome proliferator-activated receptor-gamma agonist rosiglitazone attenuate tactile allodynia in the early phase of neuropathic pain development.
Neuroinflammation triggered by macrophage infiltration into sites of peripheral nerve injury may result in neuropathic pain. Peroxisome proliferator-activated receptor (PPAR)γ signaling regulates the properties of macrophages. However, the macrophage-mediated effects of PPARγ signaling on neuropathic pain triggered by peripheral inflammation have not been investigated. ⋯ Rosiglitazone treatment in the early phase of neuropathic pain significantly alleviated the development of tactile allodynia by regulating macrophage infiltration and production of proinflammatory molecules at the inflamed site. Our results indicate that the activation of PPARγ signaling in macrophages during the early phase may suppress neuropathic pain development.
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Evidence suggests large diameter afferents, presumably in response to centrally mediated changes, augment the mechanical allodynia or hyperalgesia seen in delayed onset muscle soreness (DOMS) conditions. Healthy males aged 18 to 30 (n = 16) performed eccentric exercise eliciting DOMS in the tibialis anterior muscle of a randomly assigned exercised leg. The contralateral leg served as a control. Mechanosensitivity was assessed on the exercised and control legs prior to and 24 hours postexercise via pressure pain thresholds (PPTs). PPTs were assessed at the muscle site, and at a distant segmentally related site, either without vibration or with vibration concurrently applied to the distant muscle, segmentally related, or control extra-segmentally related site. Participants completed a 6-point Likert scale providing a subjective measure of DOMS 5 days postexercise. Baseline mechanosensitivity was not significantly different at any site between the exercised and control legs prior to the exercise. Soreness ratings were higher 24 to 48 hours postexercise (P < .05), and baseline PPTs at the exercised legs muscle site decreased postexercise (P < .001). On day 1 following exercise, segmentally related site PPTs reduced significantly when vibration was applied concurrently to the DOMS affected tibialis anterior muscle (P < .04) compared to baseline mechanosensitivity or extrasegmental control vibration. ⋯ Further evidence is presented by this article indicating that large diameter afferents, presumably via centrally mediated mechanisms, augment the mechanical hyperalgesia seen in DOMS conditions. Future research examining eccentric activity in individuals with likely centrally sensitized conditions may be warranted.