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This cross-sectional study examined the association between adverse childhood experiences (ACEs) and history of frequent headaches (including migraine) among children 3-17 years old using data from the 2016 and 2017 U.S. National Survey of Children's Health (NSCH).
Learn More >: Treatment for chronic pruritus ranges from use of topical formulations to newer biologic agents. Targeting treatment to the underlying etiology is key in reducing the burden of disease while avoiding systemic or adverse effects.: This review details the effective medical treatments used in various etiologies of chronic itch with a focus on the potential adverse effects and safety data available for each.: New drug developments in the areas of neural signaling and immune targeting show great promise for the future of chronic itch treatment. These new therapies broaden the available treatment options but also pose new considerations for safety and adverse effects.
Learn More >To investigate whether the self-treatment of migraine among neurologists and pain specialists corresponds to national medical guidelines and treatment of patients.
Learn More >Exposure to prenatal maternal stress impacts adult behavioral outcomes and has been suggested as a risk factor for chronic pain. However, the neurobiological mechanisms implicated are not well-characterized. In this study, we analyzed the effect of a prenatal maternal stress on the development of neuropathic pain-related behaviours and gene expression in the frontal cortex and hippocampus in adult offspring following chronic constriction injury of the sciatic nerve in male and female CD1 mice. Nerve injury-induced mechanical hypersensitivity was amplified in both male and female prenatally-stressed offspring, suggesting that prenatal stress exacerbates pain after injury. Analysis of mRNA expression of genes related to epigenetic regulation and stress responses in the frontal cortex and hippocampus, brain structures implicated in chronic pain, showed distinct sex and region-specific patterns of dysregulation. In general, mRNA expression was most frequently altered in the male hippocampus and effects of prenatal stress were more prevalent than effects of nerve injury in both supraspinal areas. These findings demonstrate the impact of prenatal stress on behavioral sensitivity to a painful injury. Changes in the expression of epigenetic- and stress-related genes suggest a possible mechanism by which the early life stress becomes embedded in the central nervous system. Increased understanding of the interactions among early-life stress, sex, and pain may lead to the identification of novel therapeutic targets and epigenetic drugs for the treatment of chronic pain disorders.
Learn More >Mechanotransduction, the conversion of mechanical stimuli into electrical signals, is a fundamental process underlying essential physiological functions such as touch and pain sensing, hearing, and proprioception. Although the mechanisms for some of these functions have been identified, the molecules essential to the sense of pain have remained elusive. Here we report identification of TACAN (Tmem120A), an ion channel involved in sensing mechanical pain. TACAN is expressed in a subset of nociceptors, and its heterologous expression increases mechanically evoked currents in cell lines. Purification and reconstitution of TACAN in synthetic lipids generates a functional ion channel. Finally, a nociceptor-specific inducible knockout of TACAN decreases the mechanosensitivity of nociceptors and reduces behavioral responses to painful mechanical stimuli but not to thermal or touch stimuli. We propose that TACAN is an ion channel that contributes to sensing mechanical pain.
Learn More >Pain is a classical sign of inflammation, and sensitization of primary sensory neurons (PSN) is the most important mediating mechanism. This mechanism involves direct action of inflammatory mediators such as prostaglandins and sympathetic amines. Pharmacologic control of inflammatory pain is based on two principal strategies: (i) non-steroidal anti-inflammatory drugs targeting inhibition of prostaglandin production by cyclooxygenases and preventing nociceptor sensitization in humans and animals; (ii) opioids and dipyrone that directly block nociceptor sensitization via activation of the NO signaling pathway. This review summarizes basic concepts of inflammatory pain that are necessary to understand the mechanisms of peripheral NO signaling that promote peripheral analgesia; we also discuss therapeutic perspectives based on the modulation of the NO pathway.
Learn More >Studies of the relation of fibromyalgia (FM) and widespread pain (WSP) to mortality have differed as to the presence or absence of an association and the extent of cause-specific mortality. However, no studies have investigated which definitions of FM and WSP associate with mortality, nor of FM mortality in other diseases. We investigated these issues and the meaning of mortality in patients with FM.
Learn More >AIMS The covalent linking of non-steroidal anti-inflammatory drugs (NSAIDs) to a hydrogen sulfide (H2S)-releasing moiety has been shown to dramatically reduce gastrointestinal (GI) damage and bleeding, as well as increasing anti-inflammatory and analgesic potency. We have tested the hypothesis that a H2S-releasing derivative of ketoprofen (ATB-352) would exhibit enhanced efficacy without significant GI damage in a mouse model of allodynia/hyperalgesia. RESULTS ATB-352 was significantly more potent as an analgesic than ketoprofen, and did not elicit GI damage. Pretreatment with a cannabinoid receptor-1 antagonist (AM251) significantly reduced the analgesic effects of ATB-352. The CB-1 antagonist exacerbated GI damage when co-administered with ketoprofen, but GI damage was not induced by the combination of ATB-352 and the CB-1 antagonist. ATB-352 was substantially more potent than ketoprofen as an inhibitor of fatty acid amide hydrolase, consistent with a contribution of endogenous cannabinoids to the analgesic effects of this drug. Blood anandamide levels were significantly depressed by ketoprofen, but remained unchanged after treatment with ATB-352. INNOVATION Ketoprofen is a potent analgesic, but its clinical use is significantly limited by its propensity to cause significant ulceration and bleeding in the GI tract. Covalently linking an H2S-releasing moiety to ketoprofen profoundly reduces the GI toxicity of the drug, while boosting the analgesic effectiveness.
Learn More >In this neurophysiological study, we aimed at verifying the nociceptive selectivity of the new, micropatterned electrode (150IDE), recently designed to generate an electric field limited to the intraepidermal free nerve endings.
Learn More >Fifth lumbar (L5) nerve injury in rats causes neuropathic pain manifested with thermal and mechanical hypersensitivity in the ipsilateral hind paw. This study aimed to determine whether the elimination of unmyelinated primary afferents of the adjacent uninjured nerves (L3 and L4) would alleviate peripheral neuropathic pain. Different concentrations of capsaicin or its analog, resiniferatoxin (RTX), were applied perineurally on either the left L4 or L3 and L4 nerves in Wistar rats whose left L5 nerves were ligated and cut. The application of both capsaicin and RTX on the L4 nerve significantly reduced both thermal and mechanical hypersensitivity. However, only the application of RTX on both L3 and L4 nerves completely alleviated all neuropathic manifestations. Interestingly, responses to thermal and mechanical stimuli were preserved, despite RTX application on uninjured L3, L4, and L5 nerves, which supply the plantar skin in rats. Perineural application of RTX caused downregulation of TRPV1, CGRP, and IB4 binding and upregulation of VIP in the corresponding DRG and the dorsal horn of the spinal cord. In comparison, VGLUT1 and NPY immunoreactivities were not altered. RTX application did not cause degenerative or ultrastructural changes in the treated nerves and corresponding DRGs. The results demonstrate that RTX induces neuroplasticity, rather than structural changes in primary afferents, that are responsible for alleviating hypersensitivity and chronic pain. Furthermore, this study suggests that treating uninjured adjacent spinal nerves may be used to manage chronic neuropathic pain following peripheral nerve injury. This article is protected by copyright. All rights reserved.
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