Central Pain Research Articles

Development and validation of a prognostic model for predicting post-discharge mortality risk in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI)

BackgroundAccurately predicting post-discharge mortality risk in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI) remains a complex and critical challenge. The primary objective of this study was to develop and validate a robust risk prediction model to assess the 12-month and 24-month mortality risk in STEMI patients after hospital discharge.MethodsA retrospective study was conducted on 664 STEMI patients who underwent PPCI at Xiangtan Central Hospital Chest Pain Center between 2020 and 2022. The dataset was randomly divided into a training cohort (n = 464) and a validation cohort (n = 200) using a 7:3 ratio. The primary outcome was all-cause mortality following hospital discharge. The least absolute shrinkage and selection operator (LASSO) regression model was employed to identify the optimal predictive variables. Based on these variables, a regression model was constructed to determine the significant predictors of mortality. The performance of the model was evaluated using receiver operating characteristic (ROC) curve analysis and decision curve analysis (DCA).ResultsThe prognostic model was developed based on the LASSO regression results and further validated using the independent validation cohort. LASSO regression identified five important predictors: age, Killip classification, B-type natriuretic peptide precursor (NTpro-BNP), left ventricular ejection fraction (LVEF), and the usage of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers/angiotensin receptor-neprilysin inhibitors (ACEI/ARB/ARNI). The Harrell's concordance index (C-index) for the training and validation cohorts were 0.863 (95% CI: 0.792–0.934) and 0.888 (95% CI: 0.821–0.955), respectively. The area under the curve (AUC) for the training cohort at 12 months and 24 months was 0.785 (95% CI: 0.771–0.948) and 0.812 (95% CI: 0.772–0.940), respectively, while the corresponding values for the validation cohort were 0.864 (95% CI: 0.604–0.965) and 0.845 (95% CI: 0.705–0.951). These results confirm the stability and predictive accuracy of our model, demonstrating its reliable discriminative ability for post-discharge all-cause mortality risk. DCA analysis exhibited favorable net benefit of the nomogram.ConclusionThe developed nomogram shows potential as a tool for predicting post-discharge mortality in STEMI patients undergoing PPCI. However, its full utility awaits confirmation through broader external and temporal validation.

Characterization of Neural Plasticity in Monkey Models of Neuropathic Pain – A Secondary Publication

Neuropathic pain can occur as a result of injuries and diseases of the nervous system. Animal models using rodents have been developed and characterized to reveal plastic changes underlying neuropathic pain. However, structures and functions of some brain areas that are associated with pain perception differ between rodents and primates. Therefore, animal models using non-human primates, such as the macaque monkey, with brain structures and functions closer to those of humans are important for elucidating the mechanisms underlying pain in human patients. Recently, we measured brain activity using functional magnetic resonance imaging (fMRI) in a macaque model of chemotherapy-induced neuropathic pain and reported abnormal activation of pain-related brain regions including insular and secondary somatosensory cortices. In the monkey model of central post-stroke pain, moreover, the increased activation of pain-related areas as seen in the patients was confirmed by fMRI. These results indicate that fMRI measurement of brain activity combined with behavioral outcomes in macaque models could be used not only to understand the pathogenetic mechanisms but also to test therapeutic interventions for neuropathic pain.

Predicting severe pain after cesarean section: prospective cohort study

BACKGROUND: Severe and unbearable pain after abdominal delivery is recorded in 20% of cases, indicating the limitations of the applied methods of postoperative pain relief and the need for a personalized approach. Tests assessing preoperative pain threshold and anxiety have the greatest sensitivity and specificity as predictors of intense postoperative pain. The informative value of these tests in the Russian obstetric population has not been assessed. OBJECTIVE: This study aimed to determine the optimal method for predicting severe pain after cesarean section (CS). MATERIALS AND METHODS: This prospective cohort study included 212 women who underwent elective CS under spinal anesthesia. The Hospital Anxiety and Depression Scale (HADS) anxiety rating scale, pressure algometry, and cutaneous infiltration anesthesia pain intensity assessment were used as predictors of high-intensity pain. Postoperative pain intensity was assessed using a 10-point Numeric Rating Scale (NRS). The maximum level of pain according to the central pain level at rest (NRSr) and during movement (NRSa) was recorded 24 hour postoperatively. The number of requests for “rescue analgesia” was recorded. The predictive value of the studied methods was determined based on ROC curve analysis. RESULTS: Median (interquartile range) NRSa was 5 [4–5]. Severe pain was recorded in 14% of the patients. The area under the ROC-curve (AUC), reflecting the relationship between severe postoperative pain and pressure-pain threshold, was 0.91±0.03 with 95% confidence interval (CI) of 0.84–0.97 (p 0.001). The relationship between pain intensity during infiltration anesthesia and postoperative pain severity had AUC=0.88 ± 0.04 with 95% CI of 0.81–0.96 (p 0.001). The HADS anxiety score demonstrated the lowest predictive ability (AUC=0.69±0.06; 95% CI, 0.81–0.96; p 0.001). When all three techniques were used together, the AUC was 0.924±0.024 with 95% CI 0.88–0.97 (p=0.001). CONCLUSION: Preoperative pressure-pain threshold and pain severity during infiltration anesthesia are reliable predictors of severe pain after CS. Assessment of preoperative anxiety using HADS has low sensitivity and specificity. However, its use in conjunction with methods for assessing the pain threshold increases the predictive value of the combined model compared with the results of using the methods separately.

Factors associated with the delay in informed consent procedures of patients with ST-segment elevation myocardial infarction and its influence on door-to-balloon time: a nationwide retrospective cohort study.

ST-segment elevation myocardial infarction (STEMI) is the deadliest and most time-sensitive acute cardiac event. However, failure to achieve timely informed consent is an important contributor to in-hospital delay in STEMI care in China. We investigated the factors associated with informed consent delay in patients with STEMI undergoing percutaneous coronary intervention (PCI) and the association between the delay and door-to-balloon time. We conducted a nationally representative retrospective cohort study using patient data reported by hospital-based chest pain centers from 1 January 2016 to 31 December 2020. We applied generalized linear mixed models and negative binomial regression to estimate factors independently predicting informed consent delay time. Logistic regressions were fitted to investigate the association of the informed consent delay time and door-to-balloon time, adjusting for patient characteristics. In total, 257, 510 patients were enrolled in the analysis. Mean informed consent delay time was 22.4 min (SD = 24.0), accounting for 39.3% in door-to-balloon time. Older age (≥65 years) was significantly correlated with informed consent delay time (RR: 1.034, P = 0.001). Compared with ethnic Han patients, the minority (RR: 1.146, P < 0.001) had more likelihood to extend consent giving; compared with patients who were single, longer informed consent time was found in married patients (RR: 1.054, P = 0.006). Patients with intermittent chest pain (RR: 1.034, P = 0.011), and chest pain relief (RR: 1.085, P = 0.005) were more likely to delay informed consent. As for transfer modes, EMS (RR: 1.063, P < 0.001), transfer-in (RR: 1.820, P < 0.001), and in-hospital onset (RR: 1.099, P = 0.002) all had positive correlations with informed consent delay time compared to walk-in. Informed consent delay was significantly associated with prolonged door-to-balloon time (OR: 1.002, P < 0.001). Informed consent delay is significantly associated with the door-to-balloon time which plays a crucial role in achieving better outcomes for patients with STEMI. It is essential to shorten the delay time by identifying and intervening modifiable factors that are associated with shortening the informed consent procedure in China and other countries.

Current understanding of nociplastic pain.

Nociplastic pain by the "International Association for the Study of Pain" is defined as pain that arises from altered nociception despite no clear evidence of nociceptive or neuropathic pain. Augmented central nervous system pain and sensory processing with altered pain modulation are suggested to be the mechanism of nociplastic pain. Clinical criteria for possible nociplastic pain affecting somatic structures include chronic regional pain and evoked pain hypersensitivity including allodynia with after-sensation. In addition to possible nociplastic pain, clinical criteria for probable nociplastic pain are pain hypersensitivity in the region of pain to non-noxious stimuli and presence of comorbidity such as generalized symptoms with sleep disturbance, fatigue, or cognitive problems with hypersensitivity of special senses. Criteria for definitive nociplastic pain is not determined yet. Eight specific disorders related to central sensitization are suggested to be restless leg syndrome, chronic fatigue syndrome, fibromyalgia, temporomandibular disorder, migraine or tension headache, irritable bowel syndrome, multiple chemical sensitivities, and whiplash injury; non-specific emotional disorders related to central sensitization include anxiety or panic attack and depression. These central sensitization pain syndromes are overlapped to previous functional pain syndromes which are unlike organic pain syndromes and have emotional components. Therefore, nociplastic pain can be understood as chronic altered nociception related to central sensitization including both sensory components with nociceptive and/or neuropathic pain and emotional components. Nociplastic pain may be developed to explain unexplained chronic pain beyond tissue damage or pathology regardless of its origin from nociceptive, neuropathic, emotional, or mixed pain components.

Low-dose ketamine infusion to facilitate opioid tapering in chronic non-cancer pain with opioid-use disorder: a historical cohort study

BackgroundLong-term opioid use is associated with pharmacological tolerance, a risk of misuse and hyperalgesia in patients with chronic pain (CP). Tapering is challenging in this context, particularly with comorbid opioid-use...

Healthcare professionals' experiences of interdisciplinary collaboration in pain centres - A qualitative study.

The complexity of chronic pain requires interdisciplinary collaboration. Although this is recognisable in the framework for pain centres, few studies have investigated how interdisciplinary collaboration in pain centres is experienced by healthcare professionals, including the facilitators and barriers to interdisciplinary collaboration. The aim of the current study was therefore to investigate experiences of interdisciplinary collaboration in the treatment of patients with chronic pain among healthcare professionals in tertiary care pain centres. Eleven healthcare professionals, representing different healthcare disciplines from the four regional pain centres in Norway, participated in semi-structured individual interviews. The data were analysed thematically. The results were categorised into three themes 'The best approach for chronic pain treatment', 'Collegial collaboration', and 'Challenges with interdisciplinary teamwork'. The informants valued the interdisciplinary work at the pain centre. They perceived it as the best approach for their patients and appreciated the support the collegial collaboration gave them as professionals. Although working together was rewarding and provided new insights, the informants also experienced the interdisciplinary teamwork as challenging, e.g., when the different professions disagreed on recommendations for further treatment or did not manage to work together as a team. The informants found the interdisciplinary collaboration at the pain centre to provide the best treatment approach for their patients. It should be acknowledged that interdisciplinary teamwork can be challenging, and efforts should be put into establishing a good climate for collaboration and gaining knowledge about each profession's unique character and how they contribute to pain centre treatments.

In silico exploration of CB2 receptor agonist in the management of neuroinflammatory conditions by pharmacophore modeling

Endocannabinoid system plays a pivotal role in controlling neuroinflammation, and modulating this system may not only aid in managing symptoms of neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, Multiple sclerosis, Epilepsy, Central and Peripheral neuropathic pain, but also, have the potential to target these diseases at an early-stage. In the present study, six different pharmacophore hypotheses were generated from Cannabidiol (CBD)-Cannabinoid Receptor subtype-2 (CB2) and then Zinc database was screened for identification of hit molecules. Identified 215 hit molecules were subjected to preliminary screening with ADMET and drug likeness properties, and about 48 molecules were found with no violations and toxicity properties. In molecular docking studies, six compounds showed better binding energy than CBD and β-caryophyllene (known inhibitor of CB2). These six molecules were designated as leads and subjected to re-docking with glide tool and Lead1 (ZINC000078815430) showed docking score of −9.877 kcal/mol, whereas CBD and β-caryophyllene showed score of −9.664 and −8.499 kcal/mol, respectively. Lead1 and CBD were evaluated for stability studies with Desmond tool by molecular dynamic simulation studies. Lead1 showed better stability than CBD in all studied parameters such as RMSD, RMSF, SSE, Rg, SASA, etc. In MM-GBSA free energy calculations, ΔGbinding energy of CB2-CBD complex and CB2-Lead1 were found to be −103.13±11.19 and −107.94±5.42 kcal/mol, respectively. Six lead molecules stated in the study hold promise with respect to CBD agonistic activity for treating and/or managing chronic conditions and can be explored as an alternative for early-stage cure, which has not yet been experimentally explored.

Triptan treatment is associated with a higher number of red wine-induced migraine episodes: An exploratory questionnaire-based survey.

Diet, including foods and beverages, affects migraine. Conversely, the influence of migraine therapies on dietary habits is largely unknown. This study aimed at investigating the effects of triptan intake on foods and drinks consumed by adults with migraine with and/or without aura. An exploratory questionnaire-based survey took place online between November 2022 and June 2023. Participants were recruited through advertisements shared on social media accounts (e.g., Facebook and Instagram) and seasonal newsletters of three Danish patient associations. In addition, posters and flyers in headache and pain centers at Danish hospitals and private neurological, pain, and physiotherapeutic clinics were utilized. A total of 314 adults with migraine with and/or without aura completed the survey. Among the respondents, 236 individuals (75.2%) regularly used triptans to treat their migraines. Compared with non-triptan users, individuals using triptans were characterized by significantly more foods and/or drinks triggering migraine (74.2% vs. 56.4%, p = 0.005). Alcoholic beverages and most specifically red wine were overreported as migraine triggers by triptan users (48.3% vs. 21.8%, p < 0.001). In the week preceding the survey, red wine was significantly less consumed by triptan users than non-triptan users (92.4% vs. 76.9%, p < 0.001). Patients who regularly consume triptans report red wine most frequently as a migraine trigger. Triptan users are characterized by a lower consumption of red wine than non-triptan users, suggesting that a regular triptan intake may promote an increased sensitivity to red wine-induced migraine.

Use of prescription opioids in Israel and socio-economic correlations between 2010 and 2020

BackgroundThe use of opioids has increased dramatically over the past several years in Israel. The aim of this study was to explore the trends of opioid consumption in Israel over a decade (2010–2020) stratified by socioeconomic status (SES), residence in the periphery, and ethnic background.MethodsThis cross-sectional study included all adult Maccabi Healthcare Services (MHS) patients who filled at least one prescription for opioids during the past decade. In order to standardize dosages and compare different opioid medications, we used the Morphine Milligram Equivalent (MME) conversion factor. We performed The Mann–Kendall test with autocorrelation correction to assess each trend. We then checked the differences between the trends with the Mann–Whitney test (for periphery) and the Kruskal Wallis (for SES and ethnic background).ResultsBetween the years 2010–2020, 261,270 MHS members met the study's inclusion criteria. The proportions of opioids consumption were 23.9/1000 patients in 2010 and 27.6/1000 patients in 2020, representing a 15% increase. The average daily consumption of opioids was 4.6 and 10.5 MME in 2010 and 2020, respectively, an increase of 227%. The daily MME during 2020 was higher for residents of the periphery compared to non-periphery residents (daily MME of 14.0 compared to 10.1, respectively). Average daily MME increased gradually during the study period for all levels of SES; the values were highest for the low SES group and the lowest for the high SES group (daily MME in 2020 for the lowest, middle, and high SES groups were 15.2 vs. 11.8 vs. 6.7 respectively).ConclusionsThis study highlights that the primary concern in the increase of opioid use is the increasing dosages. The increase in the number of patients using opioids is also significant but to a minor extent. These phenomena disproportionately impact vulnerable populations. Education programs should be offered to physicians regarding the possible harms of long-term use of opioids. These programs should emphasize the risk factors associated with the development of opioid use disorder (OUD) and the caution needed when increasing dosages or switching to higher-potency drugs. Pain clinics and centers for rehabilitation for patients with chronic pain or OUD should be available, not only in central areas but also in the periphery of the country. These clinics and centers should use a holistic approach and a multidisciplinary team that includes specialists in pain and addiction. They should be financially accessible for patients from low SES group and provide solutions in multiple languages.

Regional variations in management and outcomes of patients with acute coronary syndrome in China: Evidence from the National Chest Pain Center Program

Regional variations in acute coronary syndrome (ACS) management and outcomes have been an enormous public health issue. However, studies have yet to explore how to reduce the variations. The National Chest Pain Center Program (NCPCP) is the first nationwide, hospital-based, comprehensive, continuous quality improvement program for improving the quality of care in patients with ACS in China. We evaluated the association of NCPCP and regional variations in ACS healthcare using generalized linear mixed models and interaction analysis. Patients in the Western region had longer onset-to-first medical contact (FMC) time and time stay in non-percutaneous coronary intervention (PCI) hospitals, lower rates of PCI for ST-elevation myocardial infarction (STEMI) patients, and higher rates of medication usage. Patients in Central regions had relatively lower in-hospital mortality and in-hospital heart failure rates. Differences in the door-to-balloon time (DtoB) and in-hospital mortality between Western and Eastern regions were less after accreditation (β = −8.82, 95% confidence interval (CI) −14.61 to −3.03; OR = 0.79, 95%CI 0.70 to 0.91). Similar results were found in differences in DtoB time, primary PCI rate for STEMI between Central and Eastern regions. The differences in PCI for higher-risk non-ST-segment elevation acute coronary syndrome (NSTE-ACS) patients among different regions had been smaller. Additionally, the differences in medication use between Eastern and Western regions were higher after accreditation. Regional variations remained high in this large cohort of patients with ACS from hospitals participating in the NCPCP in China. More comprehensive interventions and hospital internal system optimizations are needed to further reduce regional variations in the management and outcomes of patients with ACS.

Pain sensitisation and joint inflammation in patients with active rheumatoid arthritis

IntroductionDespite better therapies and strategies, many people with rheumatoid arthritis (RA) have persistent pain, often from abnormal pain processing, now termed nociplastic pain. However, RA patients with fibromyalgia (FM), a...

Incidence, Pattern, Causes, and Outcome of Acute Chest Pain Among Patients Presenting in the Emergency Department of a Tertiary Care Hospital in North India.

Acute chest pain is a common presentation in emergency departments worldwide. Differentiating between cardiac and non-cardiac chest pain is crucial for patient management and resource allocation. This study analyzed 714 patients presenting with acute chest pain in a tertiary care hospital in North India. We investigated demographic characteristics, chief complaints, risk factors, ECG findings, and final diagnoses to identify patterns associated with cardiac (CCP) and non-cardiac chest pain (NCCP). CCP was diagnosed in 53.7% (n=383) and NCCP in 46.3% (n=331). Significant predictors of CCP included age (OR=1.05, p<0.001), smoking (OR=2.22, p<0.001), diabetes (OR=1.57, p=0.003), hypertension (OR=1.82, p<0.001), and family history of ischemic heart disease (IHD) (OR=1.42, p=0.01). Central chest pain was more common in CCP (60% vs. 40%, p<0.001), as were abnormal ECG findings such as ST-segment depression (35% vs. 10%, p<0.001) and elevation (29% vs. 6%, p<0.001). Normal ECG was more prevalent in NCCP (60%, p<0.001). Traditional cardiovascular risk factors remain strongly associated with CCP. Smoking has a particularly high odds ratio, suggesting the need for targeted interventions. ECG findings significantly aid in differentiating CCP from NCCP. This study underscores the importance of a comprehensive approach in evaluating acute chest pain to ensure accurate diagnosis and effective treatment.

Moving forward with pain: an interview with John D Loeser.

John D Loeser speaks to Thomas York, Journal Development Editor of Pain Management. John D Loeser is Professor, emeritus, of Neurological Surgery and Anesthesiology and Pain Medicine at the University of Washington where he has been a faculty member since 1969. He was the Director of the Multidisciplinary Pain Center at the University of Washington from 1983 to 1997. He has been active in research, teaching and patient care in the field of Pain Management for over 45years. He was a founding member and served as president of the American Pain Society and the International Association for the Study of Pain. He has authored or co-authored over 400 peer-reviewed articles, 129 book chapters and 8 books. He is particularly interested in multidisciplinary pain management and the development of rational strategies for the treatment of patients with chronic pain.

Lower grey matter concentration in caudate nuclei is associated with subsequent development of central post stroke pain

Lower grey matter concentration in caudate nuclei is associated with subsequent development of central post stroke pain

Implementing A Digital Health Navigator: Strategies &amp; Experience in The Hospital Setting to alleviate Digital Equity

Background: The implementation of telemedicine and digital health technologies in healthcare has increased, but patients still need help adopting and utilizing these technologies. To address this, a Digital Health Navigator (DHN) program was implemented to evaluate the benefits of improving patients’ adoption.&#x0D; Objectives: To alleviate digital equity within hospitals, we introduced a holistic digital health navigator program designed to promote the utilization of digital tools among hospitalized patients. To implement a DHN program to improve patient adoption of digital portals to engage in healthcare. To learn from the program to further develop patient-facing portal education for hospitalized patients to expand to other hospitals.&#x0D; Methods: Over a period of thirty days, the DHN program conducted patient visits in two hospitals, on portal usage, collecting data, and adapting protocols based on patient feedback.&#x0D; Results: Feedback from patients indicated 98% of patients found the education and the DHN to be helpful. 92% recommend the UPMC Central PA Portal for accessing their healthcare information. The DHN program proves beneficial in promoting portal usage and addressing technological barriers experienced by patients. We provide strategies and recommendations on how to implement such a program.&#x0D; Discussion: We successfully implemented a digital health navigator program for hospitalized patients across two hospitals. Patients reported a positive perception and satisfaction with digital health navigator visits . Notably, our model overcomes challenges related to limited internet access and mitigates technology-related anxiety during hospital stays. The DHN program proved beneficial in promoting hospital portal usage and addressing technological barriers experienced by patients. Implementation and sustained adoption of digital technologies across a large healthcare organization can be achieved through a well-coordinated, team-based, and systematic approach with a DHN. We provide strategies and recommendations on how to implement such a program

Reperfusion strategies on the clinical outcomes of ST-elevation myocardial infarction patients over 80 years old in China

Abstract Aims This study aims to explore the efficacy of reperfusion strategies on the clinical outcomes of ST-elevation myocardial infarction (STEMI) patients over 80 years old in China. Methods and results A retrospective cohort study was performed on STEMI patients over 80 years old who underwent reperfusion strategies and no reperfusion between January 2014 and December 2021, based on the Chinese Cardiovascular Association (CCA) Database-Chest Pain Center. This study included a total of 42,699 patients (mean age 84.1 ± 3.6 years, 52.2% male), among whom 19,280 (45.2%) underwent no reperfusion, 20,924 (49.0%) underwent primary percutaneous coronary intervention (PCI), and 2495 (5.8%) underwent thrombolytic therapy. After adjusting for potential confounders, multivariable logistic regression analysis revealed that patients who underwent primary PCI strategy showed a significantly lower risk of in-hospital mortality [odds ratio (OR) = 0.62, 95% confidence interval (CI): 0.57–0.67, P &amp;lt; 0.001] and the composite outcome (OR = 0.83, 95% CI: 0.79–0.87, P &amp;lt; 0.001) compared to those who received no reperfusion. In contrast, patients with thrombolytic therapy exhibited a non-significantly higher risk of in-hospital mortality (OR = 0.99, 95% CI: 0.86–1.14, P = 0.890) and a significantly elevated risk of the composite outcome (OR = 1.15, 95% CI: 1.05–1.27, P = 0.004). During a median follow-up of 6.7 months post-hospital admission, there was a percentage 31.4% of patients died, and patients in the primary PCI group consistently demonstrated a reduced incidence of all-cause mortality (hazard ratio (HR) = 0.58, 95% CI: 0.56–0.61, P &amp;lt; 0.001). Conclusion STEMI patients over 80 years old who underwent the primary PCI strategy are more likely to have favourable clinical outcomes compared to those who received no reperfusion, whereas thrombolytic therapy warrants careful assessment and monitoring.

Characteristics and outcomes of peripheral neuropathic pain patients with repeated applications of high-concentration capsaicin cutaneous patch: Results of a retrospective chart review in Germany.

The aim of this study was to evaluate patient characteristics, concomitant analgesic medication, and pain intensity in a real-world setting in Germany, focusing on the repeated application of high-concentration capsaicin patch (HCCP) for neuropathic pain. Data were collected from electronic medical records of patients who received at least two HCCP treatments between January 2011 and July 2022. Subgroup analyses were performed based on the number of HCCP treatments, age groups, and specific neuropathic pain conditions. The study was conducted at an outpatient pain center in Wiesbaden, Germany. The study included 97 patients, primarily diagnosed with neuropathic back pain, postoperative or post-traumatic neuropathic pain, and postherpetic neuralgia. The daily dose of concomitant medications (eg, opioids and anticonvulsants) at the start of capsaicin therapy was compared with the average within 2 years of capsaicin therapy. The last observation carried forward method was used if HCCP treatment was discontinued before the end of the 2-year period. The majority of patients received concomitant medications, with opioids, anticonvulsants, and antidepressants being the most common. The average daily morphine equivalent dose decreased significantly during HCCP treatment. Pain intensity at baseline was generally high, but substantial improvements were observed in patients who received at least three HCCP applications. This study provides evidence for the effectiveness of HCCP treatment in reducing pain intensity and concomitant opioid use in patients with neuropathic pain. Further research is needed to explore the long-term outcomes and optimal treatment regimens for different patient populations.

Effects and mechanisms of acupuncture analgesia mediated by afferent nerves in acupoint microenvironments.

In the past few decades, the use of acupuncture analgesia in clinical practice has increased worldwide. This is due to its various benefits, including natural alleviation of pain without causing various adverse effects associated with non-steroidal anti-inflammatory drugs (NSAID) and opioids. The acupoint represents the initial site of acupuncture stimulation, where diverse types of nerve fibers located at the acupoint hold significant roles in the generation and transmission of acupuncture-related information. In this study, we analyzed the patterns and mechanisms of acupuncture analgesic mediated by acupoint afferent fibers, and found that acupuncture stimulates acupoints which rapidly and directly induces activation of high-density primary afferent fibers under the acupoints, including myelinated A fibers and unmyelinated C fibers. During acupuncture stimulation at the muscle layer, the analgesic effects can be induced by stimulation of A fiber threshold intensity. At the skin layer, the analgesic effects can only be produced by stimulation of C fiber threshold intensity. Electroacupuncture (EA) activates A fibers, while manual acupuncture (MA) activates both A and C fibers. Furthermore, acupuncture alters acupoint microenvironments, which positively modulates afferent fibers, enhancing the transmission of analgesic signals. In addition to local activation and conduction at acupoints, nerve fibers mediate the transmission of acupuncture information to pain centers. In the spinal cord, acupuncture activates neurons by inducing afferent fiber depolarization, modulating pain gating, inhibiting long-term potentiation (LTP) of the spinal dorsal horn and wide dynamic range (WDR) neuronal activities. At higher nerve centers, acupuncture inhibits neuronal activation in pain-related brain regions. In summary, acupuncture inhibits pain signal transmission at peripheral and central systems by activating different patterns of afferent fibers located on various layers of acupoints. This study provides ideas for enhancing the precise application and clinical translation of acupuncture.

ECG of the month

In this issue’s ECG of the month, Charles Bloe presents the case of a 32-year-old man with a significant medical and family history who was experiencing severe central chest pain.