Pain medicine basics: Overview

The Journal of Pain invites contributions for a special issue focusing on pain disparities, particularly among underrepresented and/or marginalized populations. This call aims to explore the unique challenges, burdens, and resilience factors experienced by these populations. We welcome submissions from scholars of diverse and underrepresented backgrounds and from individuals with lived experiences. Topics of interest include explanatory mechanisms of pain disparities, intersectional approaches, interventions to reduce disparities, resilience factors, new frameworks, emerging technologies, underrepresented populations, recruitment methods, and basic science studies. The goal is to encourage research that explains and addresses pain disparities, moving beyond mere documentation of group differences.
Guest Editors:
Emily J. Bartley
Mary Janevic
Martha Kenney

Neuromodulation: Technology at the Neural Interface is the preeminent journal in the area of neuromodulation, providing our readership with the state of the art clinical, translational and basic science research in our field and representing the needs of the broad neuromodulation community. For clinicians, engineers, scientists and members of the biotechnology industry alike, Neuromodulation provides timely and rigorously peer reviewed articles on the technology, science and clinical application of devices that interface with the nervous system to treat disease and improve function. Neuromodulation covers an ever expanding field including pain, headache, movement disorders, spasticity, paralysis, psychiatric disorders, epilepsy, sensory deprivation, gastric dysfunction, obesity and incontinence.

Regional Anesthesia & Pain Medicine, the official publication of the American Society of Regional Anesthesia and Pain Medicine (ASRA Pain Medicine), is a monthly journal that publishes peer-reviewed scientific and clinical studies to advance the understanding and clinical application of regional techniques for surgical anesthesia and postoperative analgesia. Coverage includes intraoperative regional techniques, perioperative pain, chronic pain, obstetric anesthesia, paediatric anesthesia, outcome studies, and complications.

Abstract
Objectives: Although significant progress has been made in recent years in the field of pain modulation, information regarding patients' pain modulation profiles remains largely research-bound and is not yet easily accessible in clinical settings. The aim of this study was to develop and validate a model for estimating pain modulation profiles - including temporal summation of pain (TSP) and conditioned pain modulation (CPM) - using easily accessible measures.

Methods: This study included 347 pain-free individuals and 108 with chronic pain. TSP was induced via tonic heat pain stimulations, while CPM was evaluated using pressure pain thresholds (CPM-PPT) and tonic heat pain stimulations (CPM-HPS) as test stimuli, with the cold pressor test as the conditioning stimulus. Independent variables included demographic, psychological, and physiological measures. A LASSO regression with cross-validation was used to identify key independent.

Results: For TSP, the model explained 40% of the variance, incorporating factors such as monoamines and blood pressure. For CPM, the CPM-HPS model performed best, accounting for 35% of the variance, with blood pressure, sex and pain catastrophizing identified as important predictors.

Discussion: Overall, these results indicate that TSP and CPM can be partially estimated using readily accessible measures, but high prediction error currently limits their clinical applicability.

Abstract
Differences in pain responses between adults with or without psychiatric conditions are documented, yet the certainty of evidence on the topic has not been assessed. We examined pain responses to experimentally induced pain in individuals diagnosed with anxiety or depressive disorders compared to controls without mental health conditions. We also explored the influence of pain modality and associations between pain perception and symptoms severity. PubMed, CINAHL, PsycINFO, Cochrane, and Embase were searched from inception to March 2025. Included studies reported pain measures (pain threshold, intensity, tolerance, unpleasantness) in adults with anxiety or depression, without co-occurring chronic pain, and healthy controls. The JBI Checklist for Analytical Cross-Sectional Studies and the Quality in Prognosis Studies assessed risk of bias. Certainty of evidence was judged by the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach. Twenty-eight studies (1460 participants, 935 females) were included, most presenting moderate to high risk of bias. Compared to controls, individuals with depression exhibit higher pain thresholds [SMD = -.30 (95% CI -.60, -.01)] and pain intensity [SMD = .47 (95% CI .08, .86)], while those with anxiety exhibit lower pain thresholds [SMD = -.39 (95% CI -.61, -.17)] (GRADE: very low for all outcomes). Results differed depending on pain modality. Pain threshold was moderately correlated with depression severity: r = .437 (95% CI .208, .621). The data suggest distinct altered pain perception patterns, characterized by higher pain thresholds in depression and lower pain thresholds in anxiety. Adults with depression may be particularly sensitive, but not restricted to, ischemic stimuli. REGISTRATION: OSF (doi:10.17605/OSF.IO/U453J). PERSPECTIVE: This systematic review assessed how pain perception patterns may differ in individuals with anxiety or depression. Few studies included participants with anxiety, controlled for comorbidities, or were recently conducted, thus caution is needed before interpreting our findings. This underscores the need for updated and methodologically robust research on this field.

Abstract
Orofacial pain (OFP) encompasses a complex spectrum of conditions that present significant diagnostic challenges. The International Classification of Orofacial Pain (ICOP), introduced in 2020, offers a comprehensive diagnostic framework encompassing nearly 200 distinct OFP conditions. However, its detailed structure can impede practical use in clinical settings. To address this, we developed the International Classification of Orofacial Pain Algorithm (ICOP-AL), a flowchart-based tool designed to simplify the diagnostic process by methodically guiding users through ICOP's hierarchical criteria. International Classification of Orofacial Pain Algorithm integrates well-established diagnostic standards, including those from the International Classification of Headache Disorders, 3rd edition and Diagnostic Criteria for Temporomandibular Disorders, to enhance clinical applicability and diagnostic precision. The algorithm's validity was assessed in a study with 100 anonymized patient cases and further evaluated by clinicians across varied experience levels. The results demonstrated substantial agreement between ICOP-AL-derived diagnoses and expert clinician diagnoses (Cohen's Kappa κ = 0.688, P < 0.001), with ICOP-AL outperforming nonexpert evaluators, thereby underscoring its reliability and potential to standardize diagnostic outcomes across clinical environments. International Classification of Orofacial Pain Algorithm represents a promising step toward improving OFP diagnosis, providing a structured and accessible approach for integrating ICOP into routine clinical practice. Although early results are encouraging, further refinement and real-world validation, particularly for more detailed diagnoses, are necessary to determine its full potential as a diagnostic and educational tool.