Articles: neuralgia.
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Herpes zoster (HZ) is a painful, blistering skin eruption in a dermatomal distribution caused by reactivation of a latent varicella zoster virus in the dorsal root ganglia (DRG). Post-herpetic neuralgia (PHN) is the most common complication of acute herpes zoster (AHZ). Severe prodrome, greater acute pain and dermatomal injury, and the density of the eruption are the risk factors and predictors for developing PHN. ⋯ The idea of this newly suggested approach is to increase the awareness of the health care team and the community about the nature of HZ and its complications, especially in the high-risk groups. Besides, it emphasizes the importance of the prompt antiviral therapy and the early sympathetic blockades for preventing PHN. Key words: Acute herpes zoster, prevention, post-herpetic neuralgia, sympathetic blockade, ten-step model.
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Postherpetic neuralgia (PHN) patients suffer debilitating chronic pain, hyperalgesia, and allodynia, as well as emotional disorders such as insomnia, anxiety, and depression. The brain structure and functional basis of PHN are still not fully understood. ⋯ For PHN patients, the local brain activity abnormality was not restricted to the pain matrix. Besides regions related to pain perception, areas in charge of affective processes, emotional activity, and pain modulation also showed abnormal local brain activity in a resting state, which may suggest complicated supraspinal function and plasticity change in PHN patients. ReHo was more closely correlated with pain intensity of PHN patients than fALFF. This work indicates that besides physical and emotional pain perception, mood disorder and pain modulation could be characteristic of PHN patients. This also supports the potential use of therapeutic interventions not only restricted to pain alleviation, but that also attempt to ameliorate the cognitive and emotional comorbidities. Key words: Postherpetic neuralgia, resting-state fMRI (rs-fMRI), mood disorder, limbic system, fractional aptitude of low-frequency fluctuation (fALFF), regional homogeneity (ReHo).
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Pulsed radiofrequency (PRF) has been widely employed for ameliorating clinical neuropathic pain. How PRF alters electrophysiological transmission and modulates biomolecular functions in neural tissues has yet to be clarified. We previously demonstrated that an early application of low-voltage bipolar PRF adjacent to the dorsal root ganglion (DRG) reduced acute neuropathic pain in animals. By contrast, the present study investigated how PRF alters postsynaptic sensitization to produce early and delayed effects on neuropathic pain. ⋯ Low-voltage bipolar PRF produces LTD through selective suppression on the C-component, but not on the A-component. It also inhibits ERK activation within neurons and astrocytes in SDHs. The findings suggest that PRF alleviates long-lasting neuropathic pain by selectively and persistently modulating C-fiber-mediated spinal nociceptive hypersensitivity.Key words: Pulsed radiofrequency (PRF), dorsal root ganglion (DRG), neuropathic pain, ERK activation, evoked field potential, ATF-3, long-term depression (LTD), spinal nerve ligation (SNL).
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Pharmacol. Biochem. Behav. · Feb 2017
HYP-17, a novel voltage-gated sodium channel blocker, relieves inflammatory and neuropathic pain in rats.
Clinical and experimental studies suggest that voltage-gated sodium channels (VGSCs) play a key role in the pathogenesis of neuropathic pain and that blocking agents against these channels can be potentially therapeutic. In the current study, we investigated whether a novel compound, (-)-2-Amino-1-(4-((4-chlorophenyl)(phenyl)methyl)piperazin-1-yl)-propan-1-one(HYP-17), binds to VGSCs and evaluated its inhibitory effect on Na+ currents of the rat dorsal root ganglia (DRG) sensory neurons and its analgesic effect on inflammatory and neuropathic pain. HYP-17 (10μM) reduced both the tetrodotoxin-sensitive (TTX-S) and the TTX-resistant (TTX-R) currents in DRG sensory neurons. ⋯ Electrophysiological study showed that HYP-17 significantly attenuated the hyper-responsiveness of lumbar dorsal horn neurons. In addition, HYP-17 significantly reduced the levels of pp38MAPK and p-JNK in microglia and astrocytes, respectively, in the L4-L5 spinal dorsal horn. Therefore, our results indicate that HYP-17 has potential analgesic activities against nociceptive, inflammatory and neuropathic pain.
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Biomed. Pharmacother. · Feb 2017
Diosgenin ameliorates development of neuropathic pain in diabetic rats: Involvement of oxidative stress and inflammation.
Neuropathic pain is one of the prevalent complications of diabetes mellitus (DM). Oxidative stress and inflammation are the principal determinants for its development. Pharmacological interventions targeted at alleviating or suppressing these pathways are clinically promising. ⋯ Biochemical analysis of serum samples and sciatic nerve and dorsal root ganglion (DRG) lysates showed restoration or improvement of nuclear factor-
B (NF-κB), malondialdehyde (MDA) level, activity of superoxide dismutase (SOD), catalase, tumor necrosis factor α (TNFα), and interleukin 1β (IL-1β) upon diosgenin treatment of diabetic rats. The obtained results exhibited antinociceptive potential of diosgenin in diabetic rats through lowering oxidative stress and inflammation and improving antioxidant defense system. This suggests possible therapeutic potential of diosgenin for alleviation and management of diabetic neuropathic pain.