PainSci notes on Burton 2016:
A major driver of chronic pain is “sensitization” (basically turning up the “volume” on all pain). The phenomenon is well-known, but how it works is still a mystery, and its relationship with sleep has barely been studied. This study looked carefully 133 patients with knee arthritis, comparing those who slept well versus those who did not. They found, with a high degree of certainty, that “sleep fragmentation may strongly affect the pain and CS relationship; consequently, these results underscore the importance of considering and treating sleep in patients with chronic pain.”
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.
Knee osteoarthritis (KOA), a chronic degenerative joint disorder, is characterized by knee joint pain. Emerging research demonstrates that a significant number of patients evidence central sensitization (CS), a hyperexcitability in nociceptive pathways, which is known to increase and maintain clinical pain. The clinical correlates of CS in KOA, however, are poorly understood. Sleep disturbance is prevalent in older adults with KOA, and well known to have a bi-directional effect on pain. Recent studies suggest associations between poor sleep and measures of CS. Clinical pain and CS are overlapping concepts and are believed to also have a bidirectional relationship. While an area of expanding interest, few studies have investigated possible interactions between clinical pain, sleep, and CS. We conducted secondary data analyses on a case–control study of KOA patients with and without insomnia to examine the impact of sleep on the relationship between CS and clinical pain. A total of 133 participants were included in the current analyses (73% Female, 59% non-Hispanic white, mean age=61, SD=9.8). They completed daily diaries to evaluate sleep and clinical pain and underwent extensive quantitative sensory testing (thermal & mechanical temporal summation, after sensations and conditioned pain modulation were used to create a composite CS index). Hayes’ PROCESS macro was used to examine the effects of sleep fragmentation on the relationship between CS and clinical pain, as recorded by self-reported pain diaries. Sleep fragmentation (wake after sleep onset reported via daily diaries) mediated the relationship between CS and clinical pain (total effect p<0.001; direct and indirect effects p<0.001), even when controlling for sex and race (variables known to influence both pain and sleep). These results indicate that greater sleep fragmentation may strongly affect the pain and CS relationship; consequently, these results underscore the importance of considering and treating sleep in patients with chronic pain.
- Sensitization in Chronic Pain — Pain itself can change how pain works, resulting in more pain with less provocation
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:
- 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.
- Association Between Plantar Fasciitis and Isolated Gastrocnemius Tightness. Nakale 2018 Foot Ankle Int.
- No Added Benefit of Combining Dry Needling With Guideline-Based Physical Therapy When Managing Chronic Neck Pain: A Randomized Controlled Trial. Stieven 2020 J Orthop Sports Phys Ther.
- Effectiveness of customised foot orthoses for Achilles tendinopathy: a randomised controlled trial. Munteanu 2015 Br J Sports Med.