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The following is a summary of “Pain profiles and variability in temporal summation of pain and conditioned pain modulation in pain-free individuals and patients with low back pain, osteoarthritis, and fibromyalgia,” published in the October 2024 issue of Pain by Petersen et al. 

Researchers conducted a retrospective study to investigate the variability in temporal summation of pain (TSP) and conditioned pain modulation (CPM) in patients with chronic musculoskeletal pain, establishing cut-off values and analyzing the correlation with clinical pain intensity.   

They conducted a secondary analysis of TSP and CPM using cuff algometry in individuals free from pain (n=69) and patients with chronic low back pain (cLBP) (n=267), osteoarthritis (n=134), and fibromyalgia (n=101). The TSP and CPM in subjects free from pain were taken as a reference, 4 distinct pain profiles (TSP low/high and CPM low/high) were formed, and disparities in clinical pain between these profiles were surveyed.   

The results showed significant individual variability in data. An elevated TSP and reduced CPM were observed in fibromyalgia (P < 0.01) and osteoarthritis (P < 0.01) but not in cLBP compared to individuals free from pain. The distribution of patients across different pain profiles was significantly different (P< 0.001), with the highest proportions in the high TSP and low CPM category: 52.5% for fibromyalgia and 41.4% for osteoarthritis. Clinical pain levels did not significantly differ across pain profiles, and no notable correlations were found between clinical pain and TSP or CPM.   

They concluded that significant inter-individual variability exists in TSP and CPM among patients with chronic pain conditions and individuals free from pain, while patients with fibromyalgia and osteoarthritis may have a higher prevalence of pro-nociceptive profiles and no association with clinical pain. 

Source: onlinelibrary.wiley.com/doi/full/10.1002/ejp.4741