Sensitization of the nociceptive system in patients with low back pain and sickness absence: Disc degeneration disease or pain syndrome

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SENSITIZATION OF THE NOCICEPTIVE SYSTEM IN PATIENTS WITH LOW BACK PAIN AND SICKNESS ABSENCE O.K. Jensen1, C.V. Nielsen2, K. Stengaard-Pedersen3 1The Spine Center, Department of Internal Medicine, Region Hospital Silkeborg, 2Department of Clinical Social Medicine, University of Aarhus, and 3Department of Rheumatology, Aarhus University Hospital, Denmark Background: Measuring the number of Tender Points (TPs) is a simple standardized and validated method to estimate diffuse tenderness in the locomoter system and has been helpful in the diagnosis of fibromyalgia, a chronic pain condition characterized by sensitization of the nociceptive system. Purpose: To assess sensitization of the nociceptive system in low back pain (LBP) patients by means of TP examination and measure of Pressure Pain Threshold (PPT) on the thumb nails. To search for associations between the number of TPs and structural changes in the lumbar spine as well as pain, psychological and social factors. Design: Cross-sectional clinical study. Patient sample: Patients referred from their general practitioner and sick-listed 4-12 weeks due to LBP. Out of 239 patients with a mean age of 41.8 years and equal sex distribution, 88 patients had nerve root pain, most often caused by a herniated disc as shown by MRI. Non-specific LBP was found in 151 patients. Methods: All patients fulfilled a questionnaire including questions of leg pain, LBP pain (LBP score), psychological and social aspects. The number of TPs and PPT on the thumb nails were assessed as part of the clinical examination. A disc degeneration score (DDS) was computed from the X-ray of the lumbar spine by measuring height reductions of the five lumbar discs. Results: More than seven TPs was found in 25% of the patients. Multivariate logistic regression with inclusion of all variables showed, that more than seven TPs was associated with LBP score (OR = 1.08 (1.00-1.17), p = 0.049), DDS (OR = 0.74 (0.55-0.99), p = 0.041), nerve root affection (OR = 0.33 (0.11-0.97), p = 0.044) and sex (OR = 5.02 (2.04-12.4), p < 0.001). Bodily distress was most important in women (OR = 1.35, p = 0.017) and mental distress (anxiety) in men (OR = 1.39, p = 0.003). After adjustment for age and sex, a positive association between LBP score and DDS was found only in patients with less than six TPs (OR = 1.21 (1.0-1.47), p = 0.043). Low PPT on the thumb nails was associated with DDS and sex in a similar way. Conclusions: LBP score was positively associated with many TPs and negatively associated with disc degeneration and the occurrence of nerve root affection. This indicates, that at least in one quarter of the patients the nociceptive system was sensitized, and in these patients less structural changes in the lumbar spine was found. TP examination might be a valuable supplemental clinical tool in LBP patients.
Original languageEnglish
Publication yearSep 2007
Publication statusPublished - Sep 2007
EventEurospine - Bruxelles, Belgium
Duration: 1 Jan 2007 → …


Period01/01/2007 → …

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