One article on PainSci cites Meeus 2012: Sensitization in Chronic Pain
PainSci notes on Meeus 2012:
Sometimes the central nervous system changes so that we feel more pain with less provocation (sensitization). How much does this phenomenon complicate chronic pain problems? For instance, rheumatoid arthritis (RA) is a nasty source of chronic pain, but could some of the pain be caused by central sensitization instead of the disease itself?
Meeus et al. concluded that there are signs of this, from analyzing 24 scientific papers (although “more research is needed,” of course). RA mainly attacks joints, but patients often experience pain elsewhere, and in response to a variety of stimuli, and symmetrically — all of which are a good fit for central sensitization. Also, as with many other chronic pain conditions, in RA there’s often more (or less) pain than detectable tissue trouble (e.g. see Younes), indicating that the progress of the disease is probably not the only driver of pain. Sensitization may be the best way to explain this.
original abstract †Abstracts here may not perfectly match originals, for a variety of technical and practical reasons. Some abstacts are truncated for my purposes here, if they are particularly long-winded and unhelpful. I occasionally add clarifying notes. And I make some minor corrections.
OBJECTIVE: The goal of the present study is to systematically review the scientific literature addressing central sensitization and central nociceptive processing in patients with rheumatoid arthritis (RA).
METHODS: To identify relevant articles, we searched PubMed and Web of Science. The search strategy was a combination of terms of the following groups: "Rheumatoid arthritis," inflammatory joint pain, or arthritis; AND (central) sensitization, (central) hypersensitivity, central hyperexcitability, pain modulation, pain processing, neural inhibition, or pain physiopathology; AND pain, nociception, hyperalgesia, pain threshold, or algometry. Articles fulfilling the inclusion criteria were screened for methodologic quality with specific checklists to evaluate different study designs (2 independent raters).
RESULTS: Twenty-four full-text articles were included, of which the majority were case-control studies, followed by nonsystematic reviews, cross-sectional studies, and case reports. Methodologic quality was very heterogeneous. Preliminary evidence for generalized hyperalgesia in RA is available. In addition, the mechanism behind impaired central nociceptive processing remains rather obscure. The role of cytokines and neuropeptides especially remains to be elucidated. Windup appears to develop more easily in RA, but evidence in support of impaired nociceptive inhibition and cognitive emotional sensitization (sensitization due to cognitive bias) is scarce.
CONCLUSIONS: The symmetrical manifestation of the disease, the poor relation between disease activity and symptoms, and the generalized hyperalgesia at both articular and nonarticular sites for different kinds of stimuli are indicative of the presence of central sensitization in RA patients. Further research is required to provide firm evidence in support of various aspects of central sensitization in humans with RA.
- “Compared imaging of the rheumatoid cervical spine: Prevalence study and associated factors,” M Younes, S Belghali, S Kriaa, S Zrour, I Bejia, M Touzi, M Golli, A Gannouni, and N Bergaoui, Joint Bone Spine, 2009.
This page is part of the PainScience BIBLIOGRAPHY, which contains plain language summaries of thousands of scientific papers & others sources. It’s like a highly specialized blog. A few highlights:
- Photobiomodulation therapy is not better than placebo in patients with chronic nonspecific low back pain: a randomised placebo-controlled trial. Guimarães 2021 Pain.
- No effect of creatine monohydrate supplementation on inflammatory and cartilage degradation biomarkers in individuals with knee osteoarthritis. Cornish 2018 Nutr Res.
- The CANBACK trial: a randomised, controlled clinical trial of oral cannabidiol for people presenting to the emergency department with acute low back pain. Bebee 2021 Med J Aust.
- Relationships Between Sleep Quality and Pain-Related Factors for People with Chronic Low Back Pain: Tests of Reciprocal and Time of Day Effects. Gerhart 2017 Ann Behav Med.
- Modulation in the elastic properties of gastrocnemius muscle heads in individuals with plantar fasciitis and its relationship with pain. Zhou 2020 Sci Rep.