Clinical Journal of Pain最新文献

Objectives: We identified key predictors of the heterogeneity of treatment effects of transcranial direct current stimulation (tDCS) in individuals with knee osteoarthritis (KOA).

Methods: This is a secondary analysis of a randomized clinical trial involving 60 participants who underwent 15 daily sessions of 2-mA tDCS over three weeks. We applied group-based trajectory modeling to classify participants into distinct subgroups based on longitudinal KOA pain and symptom patterns from baseline to three months post-intervention to examine differential responses to tDCS. Four learning-based classifiers- Multi-Layer Perceptron, ElasticNet, Random Forest, and Gradient Boosting Decision Trees-were then trained to predict the trajectory subgroups using demographic, clinical, and quantitative sensory testing data collected at baseline. Feature selection methods-f-regression, mutual information, and SHapley Additive Explanations (SHAP)-were employed to identify the influential features. Additionally, SHAP was used to analyze the correlation and impact of each feature on classification.

Results: Participants exhibited distinct response patterns to tDCS: high responders (low initial symptoms with significant improvement, n=28) and low responders (high initial symptoms with minimal improvement, n=32). The influential features included pain catastrophizing, conditioned pain modulation (CPM), and pressure pain thresholds (PPTh) at the trapezius. SHAP revealed that pain catastrophizing was the most influential feature. Greater pain catastrophizing, lower CPM, and lower PPTh were associated with a higher likelihood of being classified as low responders.

Discussion: Baseline assessments of pain catastrophizing, CPM, and PPTh may be used to stratify participants, optimize treatment allocation, or tailor stimulation parameters for individuals less likely to respond to tDCS protocols.

Introduction: Herpes zoster-related pain has different phases, and the changes in glymphatic function during disease development are unknown. This study investigated stage-dependent changes in glymphatic function and mood scale scores in patients with herpes zoster-related pain, including their interrelationships.

Methods: A total of 43 patients with herpes zoster (HZ), 54 patients with subacute herpetic neuralgia (SHN), 37 patients with postherpetic neuralgia (PHN) and 30 healthy controls (HC) were ultimately included as study subjects. Diffusion tensor imaging analysis of the perivascular space (DTI-ALPS) index was used to evaluate glymphatic function. All patients were assessed with the visual analog scale (VAS), the 90-item Symptom Checklist-90-Revised (SCL-90-R), the Hamilton Depression Scale (HAMD) and the Hamilton Anxiety Scale (HAMA). ANOVA was used to determine whether there was a difference in the DTI-ALPS index among the 4 groups. Spearman's correlation analysis was used to determine the correlation between the DTI-ALPS index and each clinical scale.

Results: DTI-ALPS indices were significantly lower on the left and right sides and mean in the PHN group than in the HC group (left: P=0.025; right: P=0.014; mean: P=0.006). HAMA, HAMD, VAS-SCL-90-R, and HAMD-SCL-90-R scores showed significant positive/negative correlations across all three groups, whereas the HAMA-SCL-90-R correlation was significant in the SHN and PHN groups.

Discussion: Glymphatic dysfunction is observed in cases of zoster pain chronification, and the severity of mood disorders increases across disease stages. These findings provide both a clinical reference for how to qualify patients more comprehensively and a neuroimaging aspect to explore the mechanisms of PHN pathogenesis.

Objectives: Postoperative pain not only causes physical discomfort for patients but may also adversely affect their rehabilitation. This study aimed to explore the effect of preoperative pain education on postoperative pain and postpartum depression after elective cesarean section.

Methods: A total of 160 women scheduled for elective cesarean section were divided into the control group and observation group (80 cases in each group). The control group received routine preoperative guidance, while the observation group received preoperative pain education on the basis of routine preoperative guidance. Postoperative pain intensity was assessed. Analgesics demand, time to first ambulation and drug-related adverse reactions were recorded in both groups.

Results: The visual analog scale (VAS) scores in the observation group at 24 hours after operation were significantly lower than those in the control group (P<0.05). Additionally, the consumption of postoperative analgesic drugs was reduced (57.8±4.5 vs. 60.2±4.7 µg, P=0.001). The time to first ambulation was earlier in the observation group (4.0±0.6 vs. 4.5±0.7 h, P=0.000), and the incidence of postpartum depression was decreased (2 vs. 10, odds ratio=0.179 [95% confidence interval, 0.038-0.847], P=0.016).

Discussion: This study showed that preoperative pain education could not only effectively relieve the pain after cesarean section, reduce the use of analgesic drugs, promote early ambulation, but also reduce the incidence of postpartum depression. (Registration number: ChiCTR2400090909).

Objectives: Interindividual variability in analgesic responsiveness often results in therapy failure (TF) or adverse drug reactions (ADR) and poses a major challenge in chronic pain management, as it is influenced by multiple factors. This exploratory study investigated whether pharmacogenetic (PGx) testing could identify drug-gene-interactions (DGIs) explaining variability in drug response. Additionally, we explored whether genetic predispositions in CYP2D6 and COMT, indicating increased pain sensitivity, are linked to TF.

Methods: We analyzed data from chronic pain patients who underwent pharmacogenotyping due to suspected TF or ADR. PGx panel testing was carried out by a commercial provider. Additional genotyping of COMT rs6269, rs4633, and rs4818 was performed using PCR, RFLP, and Sanger sequencing.

Results: PGx panel testing confirmed at least one relevant genetic variant in 45% of the suspected DGIs. Notably, 41% involved the pharmacogenes CYP2D6, CYP2C19, and CYP2C9. Subgroup analyses revealed that patients carrying the COMT high pain sensitivity (HPS) allele, COMT high pain phenotype, or CYP2D6 intermediate metabolizer (IM) phenotype were significantly more likely to experience TF. Logistic regression confirmed both phenotypes as significant predictors of TF.

Discussion: Our findings support the relevance of CYP2D6, CYP2C19, and CYP2C9 as key pharmacogenes for PGx testing in chronic pain management. The results suggest that a genetic predisposition in CYP2D6 and COMT, associated with increased pain sensitivity, may contribute to insufficient analgesia and subsequent TF. These insights indicate the potential value of incorporating CYP2D6 and COMT as pain-modulating genetic markers into the broader framework of PGx testing.

Objectives: Orthopedic trauma is a major cause of disability worldwide; around half of people who sustain orthopedic trauma develop chronic pain. Quantitative sensory testing (QST) is a standardized method of assessing pain sensitivity, which may be useful in characterizing pain after injury and predicting chronic pain. This primary aim of this project was to test the feasibility of a portable QST battery, administered to adults 6-weeks post major orthopedic trauma and surgery.

Methods: 29 participants (62% male; 52% black) who sustained major orthopedic trauma and surgery completed QST testing (including static measures, conditioned pain modulation, mechanical temporal summation) at their 6-week post-operative visit and were invited to complete a 6-month follow-up survey. We examined feasibility and acceptability indices and explored associations between QST and clinical pain ratings.

Results: Of all eligible patients, 77% were recruited. QST procedures were feasible and tolerable. No participant declined participation, withdrew for reasons related to study procedures, or discontinued QST due to discomfort. No patient experienced increased clinical pain after QST. Exploratory analyses identified a positive association between static QST and pain interference at T1. Feasibility challenges included poor 6-month retention (57%), and difficulty administering QST to patients with upper extremity injuries. High rates of analgesic use prior to testing (38%) poses an additional barrier for future QST studies in this population.

Discussion: QST was acceptable and partially feasible; challenges included poor retention, high rates of analgesic use, and logistical barriers to accessing injury sites for testing. We pose several potential solutions for future research.

Objectives: This study examined how patients with high-impact chronic pain interpreted and responded to the Danish version of the Avoidance-Endurance Fast-Screen (AE-FS) to identify potential problematic items that did not correspond with item intention and causes for this.

Methods: Participants were recruited from patients referred to treatment in an interdisciplinary pain center to partake in cognitive interviews following the Three-Step Test-Interview protocol. Interview transcripts were analyzed in two steps. First, a coding analysis was used to code responses in relation to item intention using four predefined codes (congruent, incongruent, ambiguous, or confused) to identify potential problematic items (≤50% congruent responses). Second, a reflexive thematic analysis was used to uncover causes of incongruency in the problematic items as well as elements of confusion across all items.

Results: Thirty-four participants were included. Three items (1, 4, and 6) were identified as being problematic with items 1 and 4 having many incongruent responses. The most common causes of incongruency were related to formulations of items, and seven elements of confusion were uncovered across all items.

Discussion: The current study identified potential issues with participants' interpretation of three items. However, as interviews may be prone to the influence of social desirability bias, the interpretation of the results for item 4, where the most frequent non-congruent interpretation of making a fuss was equal to lack of pain validation, is done with caution. Therefore, a revision is suggested with reformulation of item 6 and removal of item 1, which, however, will require validation in future research.

Introduction: Peripheral nerve injuries (PNIs) resulting from trauma or surgery can lead to neuropathic pain and, in some cases progress to centralized pain. This condition significantly affects patients' quality of life and functional abilities. However, diagnostic criteria for centralized pain after PNI remain poorly defined, complicating patient identification and treatment. This systematic review aimede to assess current diagnostic approaches and propose evidence-based criteria for clinical diagnosis.

Methods: A systematic search of MEDLINE, Embase, Web of Science, and CENTRAL was conducted for studies assessing diagnostic approaches for centralized pain after PNI. Included studies addressed clinical characteristics, diagnostic tests, or signs of centralized pain after PNI. Exclusion criteria included acute pain studies (<3 mo), pediatric patients, and non-English articles.

Results: From 950 citations screened, 28 studies (6189 patients) were included. On the basis of the synthesized evidence, we propose the following diagnostic criteria for centralized pain after PNI: (1) documented peripheral nervous system injury or compression; (2) neuropathic pain persisting for 3 months; (3) hyperalgesia, allodynia, or other forms of hypersensitivity extending beyond the primary zone of injury; (4) associated mood/cognitive disturbances; and (5) limited response to peripheral nerve blocks, defined as <50% pain reduction, if performed.

Conclusions: This study proposes a comprehensive, evidence-based diagnostic framework for centralized pain after PNI. The algorithm combines clinical criteria with optional diagnostic testing, providing a practical approach for diagnosis that accounts for variability in access to advanced diagnostic tools. By standardizing the diagnostic process, the framework aims to enhance patient identification and support appropriate treatment selection in clinical practice.

Level of evidence: Level III-systematic reviews.

Objectives: Postoperative pain is common after Video-Assisted Thoracic Surgery (VATS). Recent evidence suggest that preoperative inflammatory biomarkers might be associated to chronic postoperative pain following major surgery, but the association between preoperative inflammation and acute pain after VATS have not been examined. This observational cohort study aimed to investigate the association between preoperative inflammatory biomarkers and acute postoperative pain in lung cancer patients undergoing VATS.

Methods: Preoperative plasma samples from cancer patients scheduled for VATS were analyzed for 92 inflammatory markers using the Olink Bioscience inflammation panel. Postoperative pain was measured during the first 48 hours using a numerical rating scale (0-10 point scale). Principal component analysis and Orthogonal Partial Least Square Discriminant Analysis (OPLS-DA) was used to identify important inflammatory markers and combined with preoperative pain and postoperative opioid usage to predict postoperative pain using a multiple linear regression model.

Results: The current study included 92 patients and 41 inflammatory biomarkers passing quality control. OPLS-DA identified 16 important markers. An initial prediction model explained 27.2% of postoperative pain variability, while a condensed model using backwards elimination, explained 34.3% of postoperative pain variability. The condensed model included the inflammatory biomarkers 4E-BP1, STAMBP, MCP-2, VEGFA, and adjusted for postoperative opioid consumption.

Discussion: The current study is the first to demonstrate an association between preoperative inflammatory biomarkers, opioid consumption, and acute postoperative pain after VATS in patients with lung cancer. Future studies are needed to confirm these findings.