Articles: neuralgia.
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Brain Behav. Immun. · Jul 2020
Toll-like receptor 7 contributes to neuropathic pain by activating NF-κB in primary sensory neurons.
Toll like receptor 7 (TLR7) is expressed in neurons of the dorsal root ganglion (DRG), but whether it contributes to neuropathic pain is elusive. We found that peripheral nerve injury caused by ligation of the fourth lumbar (L4) spinal nerve (SNL) or chronic constriction injury of sciatic nerve led to a significant increase in the expression of TLR7 at mRNA and protein levels in mouse injured DRG. Blocking this increase through microinjection of the adeno-associated virus (AAV) 5 expressing TLR7 shRNA into the ipsilateral L4 DRG alleviated the SNL-induced mechanical, thermal and cold pain hypersensitivities in both male and female mice. ⋯ Mechanistically, the increased TLR7 activated the NF-κB signaling pathway through promoting the translocation of p65 into the nucleus and phosphorylation of p65 in the nucleus from the injured DRG neurons. Our findings suggest that DRG TLR7 contributes to neuropathic pain by activating NF-κB in primary sensory neurons. TLR7 may be a potential target for therapeutic treatment of this disorder.
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Although spinal decompression surgery is an effective treatment for myelopathy-induced upper limb pain, some postoperative patients suffer from residual pain in spite of adequate decompression. However, the neural mechanism underlying the poor outcome of pain relief is still unclear. The goal of this study was to explore the brain mechanisms involved in the poor recovery of upper limb pain after the spinal decompression surgery by using functional connectivity (FC) analysis. ⋯ Our study showed that FC between the postCG and DLPFC may be a predictor of pain relief. This result suggested that assessing FC can lead to more informed surgical interventions for cervical spondylotic myelopathy.
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Glossopharyngeal neuralgia/neuropathy is rare, and less than 3% of cases involve cardiac arrhythmias of syncope due to activated vagal reflex pathways. Most of these cases are successfully treated with medical management with or without pacemaker placement. We present the first reported case of glossopharyngeal neuralgia/neuropathy with cardiac symptoms refractory to medical management including pacemaker placement but successfully treated with Gamma Knife Radiosurgery. ⋯ To our knowledge, we present the first case of glossopharyngeal neuralgia/neuropathy with medically refractory cardiac dysfunction successfully treated with Gamma Knife Radiosurgery. We advocate that Gamma Knife be considered for similar subsets of patients.
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Multicenter Study
Test-retest and inter-examiner reliability of a novel bedside quantitative sensory testing battery in postherpetic neuralgia patients.
In health and disease, the somatosensory system has been interrogated with standardized research techniques, collectively referred to as quantitative sensory testing (QST). In neuropathic pain, QST has been used to characterize multiple sensory derangements. However, the use of QST outside the lab has been limited by several factors, including a lack of standardization, variability in procedural technique, and duration of testing that would be unacceptable for clinic. ⋯ These data demonstrate that the Neuropathic Pain Research Consortium beside QST protocol is reliable across examiner and over time, providing a validated QST tool for use in clinical practice and clinical trials. PERSPECTIVE: This blinded, multicenter trial in 32 patients with postherpetic neuralgia demonstrates bedside QST is reliable and suitable as a clinical trial outcome. The novel bedside battery could be used in clinical trials or in clinical practice over time given the reliability data presented in this article.
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Extracellular nucleosides and nucleotides have widespread functions in responding to physiological stress. The "purinome" encompasses 4 G-protein-coupled receptors (GPCRs) for adenosine, 8 GPCRs activated by nucleotides, 7 adenosine 5'-triphosphate-gated P2X ion channels, as well as the associated enzymes and transporters that regulate native agonist levels. Purinergic signaling modulators, such as receptor agonists and antagonists, have potential for treating chronic pain. ⋯ These A3AR agonists are well tolerated in vivo and highly efficacious in models of chronic neuropathic pain. Furthermore, signaling molecules acting at P2X3, P2X4, P2X7, and P2Y12Rs play critical roles in maladaptive pain neuroplasticity, and their antagonists reduce chronic or inflammatory pain, and, therefore, purine receptor modulation is a promising approach for future pain therapeutics. Structurally novel antagonists for these nucleotide receptors were discovered recently.