Articles: hyperalgesia.
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Curr Pain Headache Rep · Feb 2018
ReviewChronification of Pain: Mechanisms, Current Understanding, and Clinical Implications.
The development of acute to chronic pain involves distinct pathophysiological changes in the peripheral and central nervous systems. This article reviews the mechanisms, etiologies, and management of chronic pain syndromes with updates from recent findings in the literature. ⋯ Chronic post-surgical pain (CPSP) is not limited to major surgeries and can develop after smaller procedures such as hernia repairs. While nerve injury has traditionally been thought to be the culprit for CPSP, it is evident that nerve-sparing surgical techniques are not completely preventative. Regional analgesia and agents such as ketamine, gabapentinoids, and COX-2 inhibitors have also been found to decrease the risks of developing chronic pain to varying degrees. Yet, given the correlation of central sensitization with the development of chronic pain, it is reasonable to utilize aggressive multimodal analgesia whenever possible. Development of chronic pain is typically a result of peripheral and central sensitization, with CPSP being one of the most common presentations. Using minimally invasive surgical techniques may reduce the risk of CPSP. Regional anesthetic techniques and preemptive analgesia should also be utilized when appropriate to reduce the intensity and duration of acute post-operative pain, which has been correlated with higher incidences of chronic pain.
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Objective To investigate the association between trigger points (TrPs) and widespread pressure pain sensitivity in people with tension-type headache (TTH) and to determine if this association is different between frequent episodic (FETTH) or chronic (CTTH) headache. Design A cross-sectional study. Methods One hundred and fifty-seven individuals (29% male) with TTH participated. ⋯ The number of active and latent TrPs was significantly and negatively associated with PPTs: The higher the number of active or latent TrPs, the lower the widespread PPT, and the more generalized sensitization. This association was stronger within the FETTH group than the CTTH group. Conclusions This study found that the number of TrPs in head and neck/shoulder muscles was associated with widespread pressure hypersensitivity independently of the frequency of headache.
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Human experimental pain models provide an important translational link between pre-clinical models and clinical pain. Using topical capsaicin and continuous heat application, the novel capsaicin/heat ongoing pain (CHOP) model induces long-lasting experimental pain of which the perceived intensity can be individually adjusted. ⋯ Here we demonstrate a novel pain model that can be applied for up to an hour without tissue damage. The CHOP model allows for investigation of primary and secondary hyperalgesia as well as top-down influences on sensitization, thereby providing an experimental model that can be used to assess clinically-oriented questions.
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Reg Anesth Pain Med · Feb 2018
Local Application of Ultrasound Attenuates Neuropathic Allodynia and Proinflammatory Cytokines in Rats After Thoracotomy.
We aimed to investigate the effect of therapeutic ultrasound (TU) on pain sensitivity and the concentration inflammatory cytokines in a thoracotomy rat model. ⋯ Mechanical allodynia was partially resolved with TU. Tissue temperature increased with ultrasound, while TU restricted the up-regulation of interleukin 1β and TNF-α around the injured intercostal nerve.
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Molecular neurobiology · Feb 2018
Nanoemulsion Thermoreversible Pluronic F127-Based Hydrogel Containing Hyptis pectinata (Lamiaceae) Leaf Essential Oil Produced a Lasting Anti-hyperalgesic Effect in Chronic Noninflammatory Widespread Pain in Mice.
We evaluated if a nanostructured thermoreversible Pluronic F127-based hydrogel incorporated with Hyptis pectinata leaf essential oil (NE-EOH) produces a long-lasting anti-hyperalgesic effect on chronic muscle pain in an animal model. We induced chronic muscle pain by injecting the gastrocnemius with saline injections. Paw and muscle withdrawal thresholds and motor performance were evaluated after treatment and compared with morphine, diazepam, or vehicle. ⋯ NE-EOH was shown to produce a lasting anti-hyperalgesic effect. It uses opioid and serotonin receptors, activates brainstem inhibitory pathways, and reduces the release of excitatory neurotransmitters in the spinal cord and is a substance with potential to be used in the treatment of noninflammatory pain conditions. Graphical Abstract.