Korean Journal of Pain最新文献

Background: MicroRNA (miRNA) plays a crucial role in neuropathic pain (NP) by targeting mRNAs. This study aims to analyze the regulatory function and mechanism of miR-382-5p/dual specificity phosphatase-1 (DUSP1) axis in NP.

Methods: We utilized rats with chronic constriction injury (CCI) of the sciatic nerve as the NP model. The levels of miR-382-5p and DUSP1 were reduced by intrathecal injection of lentiviral interference vectors targeting miR-382-5p and DUSP1. The mRNA levels of miR-382-5p and DUSP1 in the dorsal root ganglions (DRGs) were measured by RT-qPCR assay. The pain behavior was evaluated by mechanical nociceptive sensitivity and thermal nociceptive sensitivity. The expression levels of interleukin-6 (IL)-6, IL-1β, and tumor necrosis factor-α in the DRGs were analyzed by ELISA assay. The targeting relationship between miR-382-5p and DUSP1 was verified by DLR assay and RIP assay.

Results: Compared to the Sham group, the CCI rats exhibited higher levels of miR-382-5p and lower levels of DUSP1. Overexpression of miR-382-5p significantly decreased DUSP1 levels. Reducing miR-382-5p levels can lower the mechanical nociceptive sensitivity and thermal nociceptive sensitivity of CCI rats and inhibit the over-activation of pro-inflammatory factors. Reduced miR-382-5p levels decreased NP in CCI rats. DUSP1 is the target of miR-382-5p, and down-regulation of DUSP1 reverses the inhibitory effect of reduced miR-382-5p levels on NP.

Conclusions: Down-regulation of miR-382-5p inhibits the over-activation of pro-inflammatory factors by targeting and regulating the expression of DUPS1, thereby alleviating NP.

Chronic peripheral neuropathic pain therapy currently focuses on modulating neuroinflammatory conditions. Methylcobalamin (MeCbl), a neuroregenerative agent, modulates neuroinflammation. This review aimed to explore the molecular pharmacology action of MeCbl as a chronic peripheral neuropathic pain therapeutic agent. MeCbl plays a role in various cellular processes and may have therapeutic potential in neurodegenerative diseases. Intracellular MeCbl modulates inflammation by regulating the activity of T lymphocytes and natural killer cells as well as secretion of inflammatory cytokines, namely, tumor necrosis factor-α, interleukin-6, interleukin-1β, epidermal growth factor, and neuronal growth factor. MeCbl can reduce pain symptoms in chronic neuropathic pain conditions by decreasing excitation and hyperpolarization-induced ion channel activity in medium-sized dorsal root ganglion (DRG) neurons and the expression of transient receptor potential ankyrin 1, transient receptor potential cation channel subfamily M member 8, phosphorylated p38MAPK, transient receptor potential cation channel subfamily V members 1 and 4 in the DRG, and the voltage-gated sodium channel in axons.

Background: This study aimed to investigate the analgesic and preventive effect of low-level laser therapy (LLLT) on the incisional pain model and spinal nerve ligation (SNL) model in rats and identify the possible mechanisms of action.

Methods: Male Sprague-Dawley rats were used, divided into different treatment groups. The single application group received LLLT before or after skin incision or SNL. The consecutive application group received LLLT for six consecutive days post-incision, three days pre-incision, or three consecutive days pre-SNL. The control group underwent skin incision or SNL without LLLT. The von Frey test was used to quantify the pain associated with mechanical allodynia. Pro-inflammatory cytokine level and alterations in nerve growth factor (NGF) expression were measured by using ELISA and immunohistochemistry, respectively in the skin, muscle of the paw, and spinal cord dorsal horn (SCDH).

Results: In the incisional pain model, LLLT showed significant analgesic and preventive effect. LLLT ameliorated SNL-induced mechanical allodynia but LLLT had no preventive effect. LLLT decreased interleukin-1β (IL-1β) expression levels in the skin, muscle, and SCDH and reduced the optical density of skin and spinal cord NGF in the incisional pain model.

Conclusions: LLLT alleviated incisional pain and neuropathic pain caused by SNL in rats, and reduced the levels of IL-1β and NGF in the peripheral tissue and SCDH in the incisional pain model. LLLT might be effective in patients with post-operative pain and peripheral neuropathic pain.

Background: Cynara scolymus has bioactive constituents and has been used for therapeutic actions. The present study was undertaken to investigate the mechanisms underlying pain-relieving effects of the hydroethanolic extract of C. scolymus (HECS).

Methods: The antinociceptive activity of HECS was assessed through formalin and acetic acid-induced writhing tests at doses of 50, 100 and 200 mg/kg intraperitoneally. Additionally, naloxone (non-selective opioid receptors antagonist, 2 mg/kg), atropine (non-selective muscarinic receptors antagonist, 1 mg/kg), chlorpheniramine (histamine HH₁-receptor antagonist, 20 mg/kg), cimetidine (histamine H₂-receptor antagonist, 12.5 mg/kg), flumazenil (GABA_A/BDZ receptor antagonist, 5 mg/kg) and cyproheptadine (serotonin receptor antagonist, 4 mg/kg) were used to determine the systis implicated in HECS-induced analgesia. Impact of HECS on locomotor activity was executed by open-field test. Determination of total phenolic content (TPC) and total flavonoid content (TFC) was done. Evaluation of antioxidant activity was conducted iploying 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay.

Results: HECS (50, 100 and 200 mg/kg) significantly indicated dose dependent antinociceptive activity against pain-related behavior induced by formalin and acetic acid (P < 0.001). Pretreatment with naloxone, atropine and flumazenil significantly reversed HECS-induced analgesia. Antinociceptive effect of HECS riained unaffected by chlorpheniramine, cimetidine and cyproheptadine. Locomotor activity was not affected by HECS. TPC and TFC of HECS were 59.49 ± 5.57 mgGAE/g dry extract and 93.39 ± 17.16 mgRE/g dry extract, respectively. DPPH free radical scavenging activity (IC₅₀) of HECS was 161.32 ± 0.03 μg/mL.

Conclusions: HECS possesses antinociceptive activity which is mediated via opioidergic, cholinergic and GABAergic pathways.

Background: Cervical epidural block (CEB) is an effective intervention for managing cervical radicular pain. This study aimed to investigate the current status of performing CEB in South Korea.

Methods: Pain physicians affiliated with the Korean Pain Society were asked to complete anonymous questionnaires regarding CEB between September and October 2022. The questionnaire consisted of 24 questions assessing the current status and methods of CEB in detail.

Results: Of the 198 surveys collected, 171 physicians (86.4%) reported performing CEB. Among those, the majority (94.7%) used fluoroscopy during the procedure. The paramedian interlaminar (IL) approach was the most preferred method (50.3%). Respondents performing fluoroscopic-guided IL CEB were categorized into two groups based on clinical experience: those with ≤10 years of experience (≤10-year group, n = 91) and those with >10 years of experience (>10-year group, n = 71). The proportion of physicians obtaining informed consent in the ≤10-year group and >10-year group was 50.5% and 56.3%, respectively. When entering the epidural space during IL CEB, the contralateral oblique view was the second most frequently used in both groups (≤10-year group, 42.9%; >10-year group, 29.6%). In targeting the upper cervical lesions (C3-4), the proportion of respondents who used an IL space higher than C6-7 was 17.6% in the ≤10-year group and 29.5% in the >10-year experience group.

Conclusions: This study demonstrated variability in the CEB technique used by pain physicians in South Korea. The findings highlight the need for education on informed consent and techniques to enhance safety.

The application of ultrasound (US) in pain medicine has been a rapidly growing field since the 2000s. Musculoskeletal injections, peripheral nerve blocks, and neuraxial injections under US guidance have been acknowledged for managing chronic pain. Although many studies on US-guided pain procedures have been published, there needs to be a classification system to evaluate which image device, the US or fluoroscopy, is clinically and technically better in various pain interventions. Therefore, this narrative review introduces the classification system for the US-guided pain procedures according to their clinical and technical outcomes and designates US-guided pain procedures into one of the four categories by reviewing previous prospective randomized comparative trials.

Background: Little is known about the frequency and impact of the persistent headache and about the incidence of chronic daily headache (CDH) after coronavirus disease 2019 (COVID-19). The aim of this prospective cohort study was to assess the incidence, risk factors, characteristics, and impact of CDH in patients with COVID-19.

Methods: In the first stage, 288 patients were interviewed by telephone after the acute phase of COVID-19. Subsequently, 199 patients who presented headache were reinterviewed at least one year after COVID-19. Headaches that persisted beyond the acute phase of COVID-19 for three or more months and presented frequency ≥ 45 days over the first three months were considered to be CDH.

Results: One hundred and twenty-three patients were included, 56% were females; median age: 50 years (25th and 75th percentile: 41;58). The headache persisted beyond the acute phase of COVID-19 in 52%, and 20.3% had CDH (95% confidence interval: 13.6-28.2). Individuals who previously had headaches and who had headaches of greater intensity during the acute phase were at higher risk of developing CDH. The group with CDH included more females, greater impact of headache, more persistence of headache beyond the 120th day of COVID-19 and less throbbing headache than did the other individuals whose headache persisted.

Conclusions: Patients who had COVID-19 had a high incidence of CDH. Previous headache and greater intensity of headache were associated with higher risk of CDH.