Pain and Disability in Low Back Pain Can be Reduced Despite No Significant Improvements in Mechanistic Pain Biomarkers

Abstract

Objective: Altered balance in nociception in response to noxious stimuli is commonly reported in chronic low back pain (LBP). However, it is unclear whether an improvement in the clinical presentation is contingent on a reduction in pain sensitivity. This study investigated whether the quantitative sensory testing (QST) profile changes in people undergoing rehabilitation for LBP.Design: A prospective, observational case-control study.Methods: Forty males and females, 18 to 40 years' old (20 with LBP) participated in 2 sessions. QST was performed at baseline and after discharge from rehabilitation (LBP) or after 3 to 8 weeks (controls). The QST battery consisted of determining pressure-pain thresholds at the low back and shoulder, temporal summation of pain, and conditioned pain modulation. Questionnaire data was used to determine pain (Numeric Rating Scale [NRS]), disability (Roland-Morris Questionnaire [RMQ]), Fear Avoidance Beliefs (FABQ), and The Örebro Musculoskeletal Pain Screening Questionnaire (ÖMPSQ) at baseline and discharge. The treatment effect was determined by calculating the Cohen d.Results: No significant group×time interactions or main factor effect was found for any of the QST measures. The LBP group reported a significant reduction in NRS (P < 0.0002, d = 1.23), RMQ (P < 0.0001, d = 1.58), FABQ (P < 0.001, d = 0.87), and in the ÖMPSQ (P < 0.00001, d = 1.44). Conclusions:The results indicate that an improvement of clinical LBP is not contingent upon changes in the pain sensory profile. The value of screening pain sensitivity in LBP patients in primary care, needs to be investigated further, due to the patient population heterogeneity and the sensitivity of assessment methods.

Does a combination of self‐reported signs related to central sensitization and pressure pain threshold allow for a more detailed classification of pain‐related characteristics in patients with chronic musculoskeletal pain?: A cross‐sectional study

“…Palsson et al 47 also reported that pain intensity and disability were significantly reduced by multiple rehabilitation programs including patient education, exercise, and manual therapy. However, the PPT at both painful and remote sites did not change.…”

“…According to Mason et al, 22 PPT at both the knee and forearm did not correlate with pain intensity in patients with chronic knee pain. Palsson et al 47 also reported that pain intensity and disability were significantly reduced by multiple rehabilitation programs including patient education, exercise, and manual therapy. However, the PPT at both painful and remote sites did not change.…”

Long-term consistency of clinical sensory testing measures for pain assessment

“…Therefore, these procedures may be suitable for monitoring the painsensory profile of patients over a long-term period, e.g., to assess the recovery process over time or evaluate the impact of a treatment. Nevertheless, it is still essential to investigate the relationship between the pain-sensory profile and clinical pain, as to date, it is unclear to what extent psychophysical measures are related to the overall pain experience [46,47]. In any case, assessing the painsensory profile could be considered part of a holistic patient evaluation, supporting clinical decision-making.…”

Brain Imaging Biomarkers for Chronic Pain

“…In addition, studies using QST to differentiate pain patients from healthy controls ( 205 , 206 ) or using QST for prognostic profiling of pain patients ( 207 ) are still conflicting. Recent data has also shown that chronic pain and disability can be reduced with no associated change in QST profiles ( 208 ), and QST profiles can improve with treatment without a significant change in spontaneous subjective clinical pain ( 196 ). However, some evidence suggests that QST can predict response to chronic pain treatments ( 209 ).…”