Comparison between two pain conditioning stimuli in individuals with musculoskeletal pain

Abstract

Introduction: Musculoskeletal pain is one of the leading causes of disability worldwide. An aspect between descending and pain facilitation may be associated with central pain sensitization and its process to be chronic. Several methods were included to assess the impairment of descending inhibitory control. However, there still needs to be consensus in the literature on the appropriate methodology for the assessment. Objective: To compare the results of the conditioning stimuli of the cold pressor test (CPT) and the Cuff Pressure Test in a group of patients with musculoskeletal pain. Secondarily, to correlate the test results with the psychosocial factors of the participants. Methods: Participants aged 18 years with musculoskeletal pain in some body segments were recruited for the study. The CPT and the Cuff Pressure Test were used to assess pain's descending inhibitory control. Participants' sociodemographic characteristics were collected using a self-administered test, and psychosocial factors were assessed using the Brief Psychological Screening Questions. Results: One hundred participants (80 women, mean age 40.53±19.52 years) with moderate pain on the numeric pain scale (5.05±2.36) and mean time 31.64±55.22 months were included in this study. The correlation results of the pressure pain threshold variation (ΔLDP) between the CPT and Cuff Pressure Test methods indicate a weak correlation for the upper limb measurements (rho = 0.267, p = 0.007) and no correlation for the lower limb measurements (rho = 0.138, p = 0.170). Furthermore, the CPT and Cuff Pressure Test agreed that 56 participants had normal CPM and 10 had impaired CPM. Only the CPT correlated with the psychosocial factors of depression, anxiety and perceived stress. Conclusion: The CPT and the Cuff Pressure Test show a poor correlation in the assessment of conditioned pain modulation, in addition to not indicating good agreement in classifying the inefficiency of the descending inhibitory pathway.