Introduction to the biennial review of pain

The year 2024 marks the 50th anniversary of the International Association for the Study of Pain (IASP). Throughout 2023 and 2024, IASP celebrated this milestone with 50th Anniversary initiatives that reflect on the advances and contributions made by IASP and its members over the past 50 years, culminating with the 20th World Congress on Pain (WCP) in Amsterdam. In collaboration with the editorial board of PAIN and the scientific program committee of the WCP, this special edition of The Biennial Review of Pain, presents 11 papers from plenary lectures of this milestone WCP. The WCP kicked off with an opening session entitled “It all Began 50 Years Ago in Issaquah” that reflected on the origin of IASP and scientific discovery and since then. The first paper in the Biennial Review of Pain is based on the talks from this opening plenary session given by Jane Ballantyne and Allan Basbaum who provide insight into the major developments in the field of pain research since the very first international meeting was held in Issaquah in 1973 from which the IASP was born.1 The efforts of the early leaders in the field are highlighted and how their work paved the way for the current knowledge of pain. They provide convincing argument that whilst significant advances have been made, essential questions about pain have not changed since that time, as the quest continues to discover what causes pain and how it can be best treated. Nevertheless, major advances in the understanding of pain mechanisms have been made. The other papers in this Biennial Review are based on the subsequent plenary sessions at the WCP that included outstanding talks that addressed a broad spectrum of topics across diversity of perspectives and approaches, as well as discussions of theories, classification, and terminology of chronic pain conditions. In 2017, based on the publication of the IASP Terminology Task Force,9 IASP introduced the third mechanistic pain descriptor “nociplastic” in addition to nociceptive and neuropathic pain. Nociplastic pain is defined as “pain that arises from altered nociception despite no clear evidence of actual or threatened tissue damage causing the activation of peripheral nociceptors or evidence for disease or lesion of the somatosensory system causing the pain.”9 Since the introduction of the term, further work by the Task Force has proposed a classification and grading system to assess for the presence of “nociplastic pain” in patients with musculoskeletal pain.8 The introduction of the term has not been without controversy and arguments abound about the term, what processes it may reflect and how it should be used.3,5 Eva Kosek, as the recipient of the 2024 Ronald Melzak Award Lecture, provides an update on potential mechanisms underlying nociplastic pain and the implications for diagnostics and treatment.10 In her paper focused on an integrated whole person perspective, Helen Langevin reminds us that peripheral processes involved in pain are often overlooked and reviews mechanosensory and nociceptive innervation of deep tissues, objective, noninvasive measurements to quantify the metabolic, structural, and mechanical components of the peripheral tissue environment and the integrated understanding of pain pathophysiology across whole body.11 Of course, pain occurs across the entire lifespan and Maria Fitzgerald, recipient of the 2024 John J. Bonica award, discusses pain in infancy and the concept from Pat Wall of links between nociception (for “the sense”) and pain (“the need state”) that are very different from those of adults, although no less important.6 Tim Oberlander and colleagues consider pain as a determinant of child development, and conversely, that development is also a key determinant of a child's pain experience. They discuss how intersectional identities (eg, gender, race, socioeconomic status) and associated social, structural, systemic, and physical environments influence the relationship between development and pain.2 Jennifer Haythornthwaite, the recipient of the 2024 John D. Loeser award, presents the role of repeated pain and stress exposures throughout childhood, adolescence, and into adulthood in altering the neurobiology of pain through a repetitive positive feedback loop that increases risk for heightened pain sensitivity over time.7 Frank Lobezzo and colleagues review the complexities of assessing and managing orofacial pain and dysfunction in special needs populations such as those with Down syndrome, Parkinson disease, and dementia, along with their comorbid orofacial conditions like impaired oral health, salivary problems, and movement disorders of the masticatory system.12 They outline the need for strong interprofessional collaboration to improve health outcomes for these vulnerable patient groups. The implementation of effective treatments for people with pain remains a challenge with many complex interactions between systems and settings. Mary Cardosa brings attention to the high burden of pain in low- and middle-income countries. She reviews various educational programs, focusing on Southeast Asia, that demonstrate how targeted educational programs, which include skills training, follow-up, and mentorship, can translate into the formation of new multidisciplinary pain management services in settings with limited resources.4 Helen Slater provides emerging evidence for innovative strategies to build ecosystem resilience to support quality musculoskeletal pain care at the macrolevel (eg, informing musculoskeletal policy and health strategy priorities), at the mesolevel (eg, service codesign across care settings; health workforce capacity), and downstream, at the microlevel (eg, person-centred care).15 In a paper from a neuroimaging perspective, Marco Loggia highlights the evolving knowledge of the contributions of neuroinflammation and discusses the role of glia in the development and maintenance of persistent pain and pain-related disability.13 This research has important practical implications, contributing to rationale for the development of tailored interventions focused on glial modulation. Researchers and clinicians in the pain field can learn and be inspired from those in aligned but slightly different fields and, in recent years, an aim of WPC has been to include one plenary lecture that meets this aim. Fulfilling this goal is the paper by Masaya Nakamura, recipient of the 2024 William D. Willis, Jr., M.D., Ph.D. Memorial Lecture Award, who reviews research of innovative methods of neural cell transplantation combined with robotic rehabilitations for spinal cord injury (Nagoshi et al.).14 These methods have improved gait ability and trunk function in animal models and show promise for future clinical use. We are delighted to introduce this exciting set of reviews from our respected 2024 WCP plenary lecturers and hope the readers of PAIN both enjoy them and benefit from them. We also note that the WCP included outstanding and inspirational plenary talks Anna Hood, recipient of the 2024 Ulf Lindblom Young Investigator award; David Hohenschurz-Schmidt, recipient of the Ronald Dubner Research prize and Ben Colagiuri, recipient of the Patrick D. Wall award. And of a special note is that the 2024 WPC featured special lectures from the 2 recipients of the 2021 Nobel Prize in Physiology or Medicine, Drs. David Julius and Ardem Patapoutian, for their work on receptors for temperature and touch. Their lectures discussed the topics of TRP Channels in Pain and Analgesia (Julius), and Piezo Channels in Mechanosensory Biology (Patapoutian). We encourage readers of PAIN to read the works of all of these scientists, some of which have been in PAIN. Looking forward, we invite you to attend and participate in the next World Congress on Pain to be held in Bangkok in 2026. Conflict of interest statement The authors have no conflicts of interest to declare.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.