Articles: hyperalgesia.
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Experimental neurology · Nov 2015
Chronic stress and peripheral pain: Evidence for distinct, region-specific changes in visceral and somatosensory pain regulatory pathways.
Chronic stress alters the hypothalamic-pituitary-adrenal (HPA) axis and enhances visceral and somatosensory pain perception. It is unresolved whether chronic stress has distinct effects on visceral and somatosensory pain regulatory pathways. Previous studies reported that stress-induced visceral hyperalgesia is associated with reciprocal alterations of endovanilloid and endocannabinoid pain pathways in DRG neurons innervating the pelvic viscera. ⋯ Behavioral assessment showed that visceral hyperalgesia persisted, whereas somatosensory hyperalgesia and enhanced expression of Nav1.7 and Nav1.8 sodium channels in L4-L5 DRGs normalized 3 days after completion of the stress phase. These data indicate that chronic stress induces visceral and somatosensory hyperalgesia that involves differential changes in endovanilloid and endocannabinoid pathways, and sodium channels in DRGs innervating the pelvic viscera and lower extremities. These results suggest that chronic stress-induced visceral and lower extremity somatosensory hyperalgesia can be treated selectively at different levels of the spinal cord.
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Osteoarthr. Cartil. · Nov 2015
Intra-articular nerve growth factor regulates development, but not maintenance, of injury-induced facet joint pain & spinal neuronal hypersensitivity.
The objective of the current study is to define whether intra-articular nerve growth factor (NGF), an inflammatory mediator that contributes to osteoarthritic pain, is necessary and sufficient for the development or maintenance of injury-induced facet joint pain and its concomitant spinal neuronal hyperexcitability. ⋯ Findings demonstrate that NGF in the facet joint contributes to the development of injury-induced joint pain. Localized blocking of NGF signaling in the joint may provide potential treatment for joint pain.
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Randomized Controlled Trial
Movement Evoked Pain and Mechanical Hyperalgesia after Intramuscular Injection of Nerve Growth Factor: A Model of Sustained Elbow Pain.
Lateral epicondylalgia presents as lateral elbow pain provoked by upper limb tasks. An experimental model of elbow pain provoked by movement/muscle contraction and maintained over several days is required to better understand the mechanisms underlying sustained elbow pain. This study investigated the time course and pain location induced by nerve growth factor (NGF) injection into a wrist extensor muscle, and whether movement and muscle contraction/stretch provoked pain. ⋯ This article presents a novel experimental human pain model suitable to study the sustained effects of lateral elbow pain on sensorimotor function and to probe the mechanisms underlying persistent musculoskeletal pain.
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Reg Anesth Pain Med · Nov 2015
Pressure Pain Sensitivity in Patients With Suspected Opioid-Induced Hyperalgesia.
This study was designed to test whether a brief quantitative sensory testing assessment could be used to detect hyperalgesia in patients with suspected opioid-induced hyperalgesia (OIH). ⋯ Whereas there were no differences between patients suspected of having OIH and the healthy controls, the finding that higher doses of opioids were associated with more sensitivity suggests that dose might be an important factor in the development of hyperalgesia. In addition, male patients demonstrated a hyperalgesic response after a bolus of fentanyl. Future studies are needed to develop better diagnostics for detecting hyperalgesia in the clinical setting.