Korean Journal of Pain最新文献

Background: Ultrasound-guided abdominal wall blocks are increasingly used to enhance postoperative analgesia in laparoscopic nephrectomy. Among these, the transversus abdominis plane (TAP) block and the quadratus lumborum (QL) block have emerged as promising techniques. However, no comprehensive review has yet compared the analgesic efficacy of these two regional approaches.

Methods: An extensive search was conducted across MEDLINE, Embase, Cochrane Library, Web of Science, and Google Scholar to identify randomized controlled trials comparing the postoperative analgesic effects of the TAP block, QL block, and systemic analgesia. The primary outcome was 24-hour opioid consumption, standardized to intravenous morphine milligram equivalents (MME). Secondary outcomes included postoperative pain scores assessed using a 0-10 Visual Analog Scale (VAS). A minimal clinically important difference (MCID) was defined as a reduction of 10 mg MME or 1 point on the VAS.

Results: Twelve studies were included. Both TAP and QL blocks significantly reduced opioid consumption compared to systemic analgesia (mean difference [95% confidence interval, CI]: QL, -11.42 mg [-18.88 to -3.97]; TAP, -10.88 mg [-17.49 to -4.26]). However, the 95% CI did not meet the predefined MCID of -10 mg. Similarly, improvements in postoperative pain scores did not reach clinical significance.

Conclusions: While TAP and QL blocks demonstrated a significant analgesic effect compared to systemic analgesia, the clinical relevance of this benefit may be limited.

Background: Antiepileptic drugs have shown promise in treating acute nociceptive pain. Bioisosterism is a crucial strategy in analgesic development, enabling molecular modifications that improve therapeutic efficacy and safety. This study aims to develop and evaluate new compounds based on the concept of bioisosterism, synthesizing organocomplexes derived from compounds with established analgesic properties.

Methods: A novel prototype, Zn(Valp)₂Bipy was synthesized, characterized, and tested for antinociceptive and toxicological effects in mice. The compound was administered orally at different doses to evaluate inhibition of acetic acid-induced abdominal constrictions and both phases of the formalin test. Additional evaluation included hot plate and tail immersion assays for central antinociception, the open field test for motor coordination, and a 14-day regimen for subacute toxicity.

Results: Zn(Valp)₂Bipy (0.1, 1, and 10 mg/kg) significantly reduced abdominal constrictions and licking time in both phases of the formalin test. In the hot plate and tail immersion tests, this treatment significantly increased the latency period, indicating enhanced pain tolerance. Notably, the analgesic effect observed in the hot plate test was reversed by naloxone, suggesting an opioid-like action. Furthermore, in the open field test, the treatment did not affect the animals' motor function. When administered daily at a dose of 1 mg/kg for 14 days, the compound exhibited no observable toxicity, underscoring its safety profile.

Conclusions: Zn(Valp)₂Bipy demonstrated significant antinociceptive activity through central and peripheral mechanisms without detectable toxicity. This study provides the first evidence of analgesic potential for this complex, highlighting it as a promising drug prototype for effective pain management therapies.

Background: Fibromyalgia (FM) and major depressive disorder (MDD) frequently co-occur. This study investigated whether the differences in resting-state functional connectivity (rs-FC) of the emotion- and pain-related brain networks may differentiate FM patients with and without MDD and if these differences are associated with the severity of clinical symptoms, quality of life, recurrent depression, pain catastrophizing, and antidepressant use.

Methods: In this study, the authors recruited a sample of 37 females classified as FM with MDD (FM + MDD, n = 23) or FM without MDD (FM-only, n = 14) based on the International Neuropsychiatric Interview. The severity of depressive symptoms was measured using the Beck Depression Inventory-II (BDI-II).

Results: Age-adjusted rs-FC correlated significantly with BDI-II scores. FM + MDD patients showed increased rs-FC between the right ventral insula and left middle frontal gyrus (MFG) (χ²(1) = 5.54, P = 0.019, effect size [ES] = 0.87), and decreased rs-FC between the caudal hippocampus and middle cingulate cortex (χ²(1) = 6.65, P < 0.001, ES = 0.90). Increased rs-FC between the ventral insula and MFG was positively associated with recurrent MDD and pain catastrophizing, and negatively with FM-related quality of life. The connection between the left MFG and the right posterior parietal thalamus is associated with recurrent MDD and pain catastrophizing.

Conclusions: Distinct neurofunctional patterns in regions related to emotional regulation and cognitive control of pain-marked by increased inter-hemispheric frontal and decreased intra-hemispheric limbic-cingulate connectivity-may serve as potential biomarkers to distinguish FM patients with comorbid MDD from those without.

Multimodal analgesia, incorporating agents with diverse mechanisms of action, is a cornerstone of perioperative pain management, aiming to optimize analgesia while minimizing opioid-related adverse effects. Despite well-established guidelines, its adoption remains inconsistent due to entrenched practices and concerns about potential risks. This review focuses on the rationale and clinical considerations for foundational multimodal agents-acetaminophen, non-steroidal anti-inflammatory drugs, and dexamethasone-highlighting their benefits, contraindications, and controversies. Evidence regarding key concerns, including hepatotoxicity, nephrotoxicity, anastomotic leakage, bleeding, infection, and hyperglycemia, is comprehensively reviewed. While these concerns are not entirely unfounded, clear supporting data is often limited, highlighting the importance of a critical and thorough evaluation of the available evidence. Indiscriminate advocacy for or reluctance to adopt multimodal analgesia is equally undesirable; instead, a balanced, evidence-based approach is necessary. By refining the understanding of these agents, practitioners can support the broader implementation of multimodal analgesia in perioperative care, ultimately improving patient recovery and optimizing postoperative outcomes.

Background: This study examines Transcranial Direct Current Stimulation (tDCS), a non-invasive brain stimulation technique, as an alternative for pain management given the limitations of pharmacological treatments.

Methods: We searched PubMed, Scopus, and the Cochrane Library for systematic reviews and meta-analyses (SRMAs) on the efficacy of tDCS across pain-related conditions. Outcomes included treatment regimens, mechanisms, effects, and adverse events. Methodological quality was assessed with AMSTAR-2 and evidence levels with GRADE.

Results: Forty-one SRMAs were included. Positive effects were observed across 14 pain-related conditions, including 10 pain mechanism-specific outcomes and 6 other pain-related outcomes. Analgesic effects were reported in the short-, mid-, and long-term (up to 4 weeks), especially with stimulation over the primary motor cortex.

Conclusions: Our findings suggest that tDCS might be effective for fibromyalgia, migraine, and neuropathic pain associated with spinal cord injury and stroke. However, further evidence is needed for chronic orofacial pain, multiple sclerosis, knee osteoarthritis, central post-stroke pain, intra-abdominal pain, and phantom limb pain. As most of the evidence stems from reviews with "critically low" quality, more high-quality studies are needed in the future.

Background: Cancer-induced bone pain (CIBP) is a significant and challenging comorbidity closely related to cancer metastasis. Long noncoding RNAs (lncRNAs) have been implicated in both cancer progression and pain modulation, however, their specific role in CIBP remains unclear. The present study aims to elucidate the potential mechanisms by which lncRNA NONRATT007487.2 contributes to the development of CIBP.

Methods: A CIBP model was established by injecting Walker 256 mammary gland tumor cells into the tibial canal of rats. To assess cancer-induced pain behavior, the authors measured the paw withdrawal threshold and paw withdrawal latency. Transcriptome sequencing was conducted to identify the pathways and genes regulated by lncRNA NONRATT007487.2. Additionally, immunofluorescence, RNA fluorescence in situ hybridization (FISH), and RNA pulldown assays were performed to investigate the relationship between lncRNA NONRATT007487.2 and C-X-C motif chemokine ligand 1 (CXCL1).

Results: It was observed that lncRNA NONRATT007487.2 was significantly upregulated in the spinal cords of CIBP rats. Knockdown of lncRNA NONRATT007487.2 alleviated both mechanical and thermal hyperalgesia in these rats and appeared to inhibit the chemokine signaling pathway. Notably, CXCL1 expression was notably reduced following the loss of lncRNA NONRATT007487.2. FISH assays demonstrated co-location of lncRNA NONRATT007487.2 and CXCL1 in the spinal cord, and RNA pulldown assays confirmed the direct interaction between these two molecules.

Conclusions: The results indicated that lncRNA NONRATT007487.2 plays a crucial regulatory role in CIBP through its interaction with CXCL1, presenting a potential therapeutic target for alleviating nociceptive hypersensitivity associated with bone metastasis.