Articles: neuralgia.
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Chemotherapy-induced peripheral neuropathy (CIPN) is a common adverse effect experienced by cancer patients receiving treatment with paclitaxel. The voltage-gated sodium channel 1.7 (Nav1.7) plays an important role in multiple preclinical models of neuropathic pain and in inherited human pain phenotypes, and its gene expression is increased in dorsal root ganglia (DRGs) of paclitaxel-treated rats. Hence, the potential of change in the expression and function of Nav1.7 protein in DRGs from male rats with paclitaxel-related CIPN and from male and female humans with cancer-related neuropathic pain was tested here. ⋯ This is key as gain-of-function mutations in human Nav1.7 recapitulate both the distribution and pain percept as shown by CIPN patients. This work also shows that Nav1.7 is increased in human DRG neurons only in dermatomes where patients are experiencing acquired neuropathic pain symptoms. This work therefore has major translational impact, indicating an important novel therapeutic avenue for neuropathic pain as a class.
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Chemokine CXC receptor 4 (CXCR4) in spinal glial cells has been implicated in neuropathic pain. However, the regulatory cascades of CXCR4 in neuropathic pain remain elusive. Here, we investigated the functional regulatory role of miRNAs in the pain process and its interplay with CXCR4 and its downstream signaling. ⋯ miR-23a, by directly targeting CXCR4, regulates neuropathic pain via TXNIP/NLRP3 inflammasome axis in spinal glial cells. Epigenetic interventions against miR-23a, CXCR4, or TXNIP may potentially serve as novel therapeutic avenues in treating peripheral nerve injury-induced nociceptive hypersensitivity.
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Schwannoma is a common neoplasm in the peripheral and central nervous systems. Sciatic nerve schwanommas are rare. We report the case of a 50-year-old woman who was referred for treatment of persistent neuropathic pain in the left lower limb after resection of a schwannoma on the left S1 nerve root. ⋯ The patient had immediate pain relief after the block (VAS 1/10). She remained pain free for 15 days after which pain reappeared but with less severity (3/10). Repetitive sciatic nerve block was performed in a progressive manner and was shown to be effective in managing neuropathic pain.
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Curr Pain Headache Rep · Jan 2018
Radio Frequency Ablation and Pulsed Radiofrequency for Treating Peripheral Neuralgias.
Peripheral nerve pain is common among patients with typical management including the use of pain medications, neuropathic agents, steroid injections, and nerve blocks. Additionally, the use of pulsed radiofrequency (PRF) and radiofrequency ablation (RFA) can be used in the management of chronic peripheral nerve pain. Previous studies investigating the effectiveness of RFA and PRF, typically case reports, have demonstrated that peripheral nerve RFA and PRF have the potential to provide relief of chronic pain for long duration. Our study aimed at testing efficacy of RFA/PRF for treating peripheral neuralgia. This was a retrospective review. We identified 16 patients who received 17 RFAs/PRFs. Outcomes of interest collected included pain scores before and after procedures, percent improvement in pain after each procedure, and duration of improvement until the time of data collection. In addition, demographic data including age, sex, and nerves involved were collected. ⋯ Eleven patients (12 RFAs/PRFs) (80%) reported improvement after their procedure. Pain scores improved significantly from 6.3 ± 2.3 before each procedure to 3.6 ± 2.7 after each procedure (p = 0.003). Eleven patients (12 RFAs/PRFs) reported an average improvement of 60.8% ± 35% after their procedure with an average duration of improvement of 128.8 ± 106.8 days. RFA and PRF can be used to treat chronic peripheral pain after conservative methods fail to do so. Large clinical trials are needed to confirm our finding.
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Neuroscience letters · Jan 2018
Role of KCNQ2 channels in orofacial cold sensitivity: KCNQ2 upregulation in trigeminal ganglion neurons after infraorbital nerve chronic constrictive injury.
Sensitivity to cooling temperatures often becomes heightened in orofacial regions leading to orofacial cold allodynia/hyperalgesia after chronic trigeminal nerve injury. KCNQ2 channels are involved in controlling excitability of primary afferent neurons and thereby regulate sensory functions under both physiological and pathological conditions. In the present study, we sought to determine whether KCNQ2 channels in trigeminal nerves are involved in regulating orofacial operant behavioral responses to cooling stimulation. ⋯ Interestingly, KCNQ2 channel expression becomes significantly upregulated in TG neurons following the ION-CCI. Our results suggest that KCNQ2 channels are involved in regulating orofacial cold sensitivity. Upregulation of KCNQ2 channels may be a compensatory change in attempting to limit injury-induced trigeminal hyperexcitability.