02/08/2025
Wirklich super Artikel von Hoegh und wie immer tolle Zusammenfassung von Physio Meets Science! Die anderen Artikel aus der Reihe sind auch sehr lesenswert!
Just publised 🔥
Pain Science in Practice: Nociceptive, Neuropathic and Nociplastic Pain
🧠 Understanding chronic pain through mechanistic descriptors represents a paradigm shift from symptom-based classification to mechanism-based treatment. Traditionally, pain has been categorized by site, duration, and pathology. However, the International Association for the Study of Pain (IASP) has advanced a tripartite model of pain comprising nociceptive, neuropathic, and nociplastic pain, each reflecting distinct (though overlapping) biological underpinnings (Kosek et al., 2016; Nicholas et al., 2019). This classification aims to enhance personalized pain management, particularly for musculoskeletal disorders (Shraim et al., 2021; Kaplan et al., 2024).
📘 In a brand-new paper, published in JOSPT, Hoegh and Hodges (2025, https://www.jospt.org/doi/10.2519/jospt.2025.13335) critically review the theoretical basis, clinical applicability, and limitations of these descriptors, especially nociplastic pain—a more recent and controversial addition. Their paper contributes to a growing body of literature advocating for a nuanced understanding of pain that integrates neurobiological, psychological, and sociocultural dimensions.
✅ Pain Mechanisms and Mechanistic Descriptors
▶️ Pain mechanisms are the neurobiological processes (e.g., central sensitization, wind-up) underlying pain, while mechanistic descriptors categorize pain based on presumed dominant mechanisms. Importantly, descriptors are not mechanisms themselves, but clinical clusters presumed to reflect them.
These include:
▶️ Nociceptive pain: Driven by activation of nociceptors in response to actual or threatened tissue damage (e.g., mechanical, chemical, thermal stimuli).
▶️Neuropathic pain: Resulting from demonstrable lesions or diseases of the somatosensory nervous system (s. figure for neuropathic pain grading system)
▶️ Nociplastic pain: Characterized by altered nociception without clear evidence of tissue damage or neural lesions (IASP, 2024).
✅ Evolution of Pain Classification
Originally, pain was classified by stimulus type and symptoms. Woolf and colleagues (2000) proposed four mechanisms—no ciceptive, inflammatory, neuropathic, and dysfunctional—each linked to specific neuroimmune changes. This was later distilled into three descriptors for clinical simplicity and utility (Costigan & Woolf, 2000).
✅ Clinical Use and Limitations
1️⃣ Overlap and Ambiguity
👉 Most chronic pain presentations exhibit mixed features. For instance, neuropathic and nociplastic components may coexist, as in fibromyalgia or multiple sclerosis. Thus, strict categorization is often unrealistic.
2️⃣ Lack of Specific Biomarkers
👉 Unlike neuropathic pain, which can sometimes be verified via imaging or neurophysiological testing (Finnerup et al., 2016), nociplastic pain lacks objective markers. Sensitization—a core mechanism—is difficult to measure directly in humans and is inferred from symptoms like allodynia or hyperalgesia (Adams et al., 2023).
3️⃣ Translational Gaps from Animal Models
👉 Animal models of pain (e.g., Spared Nerve Injury) fail to capture human pain complexity, leading to poor clinical translation (Yezierski & Hansson, 2018).
4️⃣ Sociopsychological Underrepresentation
👉 Mechanistic descriptors inadequately capture the full experience of pain, which is influenced by beliefs, context, and social factors (Hoegh et al., 2022).
5️⃣ Nociplastic Pain as a Placeholder
👉 Introduced to explain pain not classifiable as nociceptive or neuropathic, nociplastic pain risks remaining a vague category unless anchored to measurable phenomena (Kosek et al., 2016; Kaplan et al., 2024). There is ongoing debate whether it overlaps or is synonymous with “chronic primary pain” in the ICD-11 (Nicholas et al., 2019).
✅ Clinical Implications
While not yet mature enough to dictate individualized interventions, mechanistic descriptors may guide selection of therapeutic tools. However, current evidence supports their use primarily as heuristic guides rather than definitive diagnostic tools. Continued research is essential to refine these categories, validate diagnostic criteria, and align treatments with underlying neurobiological profiles.
📷 Figure (Schmid et al. 2023):
🔀 Clinical Criteria for Grading Neuropathic Pain (Possible, Probable, and Definite)
Before applying this grading system, the pain must have persisted for at least three months, and other plausible causes of the pain must be excluded.
The following criteria are used to determine the level of certainty:
▶️ Possible Neuropathic Pain: Pain is reported in a distribution consistent with the innervation of the nervous system. History suggests a relevant lesion or disease affecting the somatosensory system.
▶️ Probable Neuropathic Pain: Criteria for "Possible" are met. In addition, clinical examination reveals sensory signs (e.g., hypoesthesia or sensory loss) in the same area as the pain and consistent with a somatosensory lesion.
▶️ Definite Neuropathic Pain: Criteria for "Probable" are met. Plus, there is objective confirmation (e.g., imaging, neurophysiological testing, or biopsy) of a lesion or disease affecting the somatosensory system, which explains the pain.
Note: Clinical testing (Criterion 3) is considered fulfilled if any sensory assessment shows partial or complete loss of function matching the distribution of the lesion. Criterion 4 (objective confirmation) can still be met even if Criterion 3 is not, as long as the lesion or disease clearly accounts for the pain symptoms.
📒 Reference List
Adams GR et al. (2023). Pain, 164(6):1222–1239. https://doi.org/10.1097/j.pain.0000000000002830
Costigan M, Woolf CJ. (2000). J Pain, 1(3):35–44. https://doi.org/10.1054/jpai.2000.9818
Derry S et al. (2019). Cochrane Database Syst Rev, CD007076. https://doi.org/10.1002/14651858.CD007076.pub3
Finnerup NB et al. (2016). Pain, 157(8):1599–1606. https://doi.org/10.1097/j.pain.0000000000000492
Schmid A et al. (2023). Pain, 164(8):1693-1704. https://doi:10.1097/j.pain.0000000000002919
Hoegh M et al. (2022). Pain, 163(8):e963. https://doi.org/10.1097/j.pain.0000000000002662
Hoegh M, Hodges PW. (2025). J Orthop Sports Phys Ther. https://doi.org/10.2519/jospt.2025.13335
Kaplan CM et al. (2024). Nat Rev Neurol. https://doi.org/10.1038/s41582-024-00966-8
Kosek E et al. (2016). Pain, 157(7):1382–1386. https://doi.org/10.1097/j.pain.0000000000000507
Nicholas M et al. (2019). Pain, 160(1):28–37. https://doi.org/10.1097/j.pain.0000000000001390
Yezierski RP, Hansson P. (2018). J Pain, 19(6):571–588. https://doi.org/10.1016/j.jpain.2017.12.261
