Articles: neuralgia.
-
Curr Pain Headache Rep · Feb 2022
ReviewModulatory Effects of Stem Cells on Opioid Receptors and Neuroinflammation.
This narrative review examines stem cell therapy and its effect on opioid therapy in neuropathic pain. ⋯ Stem cell therapy has shown promise in neuropathic pain and opioid tolerance, with a notable common pathway (the P2X4 receptor). Opioid therapy frequently has poor efficacy in patients who suffer from neuropathic pain. There is evidence that the presence of neuropathic pain itself causes changes to the opioid receptor, decreasing the therapeutic potential of this modality. The efficacy of opioid therapy is further decreased in this patient population after chronic opioid exposure, which leads to opioid tolerance and in some cases opioid-induced hyperalgesia. There is growing evidence that stem cell therapy has potential to treat neuropathic pain and may simultaneously decrease opioid tolerance and hyperalgesia. Opioid-induced hyperalgesia occurs via mu-opioid receptor-dependent expression of P2X4 receptors on microglia. Intrathecal stem cell therapy provides analgesic properties due to the significant reduction of P2X4R expression in spinal cord microglia, thereby directly decreasing chronic neuropathic pain.
-
Neuropathic pain arises as a direct consequence of a lesion or disease affecting the somatosensory system. A number of preclinical studies have provided evidence for the involvement of cytokines, predominantly secreted by a variety of immune cells and by glial cells from the nervous system, in neuropathic pain conditions. Clinical trials and the use of anti-cytokine drugs in different neuropathic aetiologies support the relevance of cytokines as treatment targets. However, the use of such drugs, in particularly biotherapies, can provoke notable adverse effects. Moreover, it is challenging to select one given cytokine as a target, among the various neuropathic pain conditions. It could thus be of interest to target other proteins, such as growth factors, in order to act more widely on the neuroinflammation network. Thus, platelet-rich plasma (PRP), an autologous blood concentrate, is known to contain a natural concentration of growth factors and immune system messengers and is widely used in the clinical setting for tissue regeneration and repair. ⋯ Preclinical and clinical studies highlight the idea of a cytokine imbalance in the development and maintenance of neuropathic pain. Clinical trials with anticytokine drugs are encouraging but are limited by a 'cytokine candidate approach' and adverse effect of biotherapies. PRP, containing various growth factors, is a new therapeutic used in regenerative medicine. Growth factors can be also considered as modulators of cytokine balance. Here, we emphasize a potential therapeutic effect of PRP on cytokine imbalance in neuropathic pain. We also underline the clinical interest of the use of PRP, not only for its therapeutic effect but also for its safety of use.
-
During the last decades, platelet-rich plasma has been studied for the treatment of multiple chronic pain conditions, in addition to being employed in the enhancement of healing after tissue injury. ⋯ Future research addressing the utilization of platelet-rich plasma in the treatment of chronic pain conditions should focus on shedding light on the following major questions: a) Is there a dose-effect relation between the platelet count and the clinical efficacy of the preparation?; b) What pathology determinants should be considered when selecting between leukocyte-enriched and leukocyte-depleted concentrates?; c) What is the role of platelet activation methods on the clinical efficacy of platelet-rich plasma?; d) Is there an optimal number of injections and time frame for application of multiple injection treatment cycles?; e) Does the addition of local anesthetics affect the clinical efficacy of platelet-rich plasma?; and f) Is there potential for future platelet-rich plasma applications for the treatment of neuropathic pain of peripheral origin?
-
Curr Pain Headache Rep · Jan 2022
ReviewTitle: Novel Analgesic Potential of ß2-Agonists for Neuropathic Pain via ß2-Agonist Action.
Multimodal therapies are often employed to treat chronic pain, and ß2-agonists are a potential drug class that shows promise. The primary aim of this paper is to discuss the role of ß2-agonists as an adjunctive therapy for chronic pain based on the current literature. ⋯ Recent studies in mouse models have shown that the ß2-adrenergic system plays an essential role in the analgesic properties of antidepressant drugs used to treat neuropathic pain and that the adrenergic relies on an intact endogenous opioid system to be effective. Studies also show that ß2-agonism alone is adequate to exert anti-allodynic effects in a mouse model. This paper summarized the basic physiology and pharmacology of the sympathetic nervous system and specifically the ß2-adrenergic system and summarized current literature in its involvement in the treatment of chronic neuropathic pain.
-
Meta Analysis
Efficacy and Safety of N-acetylcysteine for the Management of Chronic Pain in Adults: A Systematic Review & Meta-analysis.
To assess the efficacy and safety of N-acetylcysteine in the treatment of chronic pain. ⋯ While there is some evidence to indicate N-acetylcysteine may provide analgesic efficacy for certain pain conditions, there is insufficient evidence to provide definitive evidence on NAC in chronic pain management. Larger-size RCTs spanning a variety of chronic pain conditions are needed to determine N-acetylcysteine's role, if any, in pain medicine.