New trends in rehabilitation: patient profiling as pain biomarkers

Abstract

Chronic pain is a main cause of disability in female adults and in the elderly population. The World Report on Disability estimates that over one billion people Contemporary pain management shifted from symptom control to management based on pathophysiological mechanisms. The clear understanding of the mechanisms involved in pain generation, modulation, amplification and perpetuation plays a potential role in patient profiling to recognize indicators of these complex processes.
Serum levels of pro-inflammatory cytokines, for example, may differentiate people with chronic pain compared with healthy controls. Recently, it has been recognized that constant and intense nociceptive sensory information generated by painful, inflamed deep somatic structures produce significant neurochemical and metabolic changes and reorganizations within corresponding spinal cord segments. Increased excitability of dorsal horn neurons producing pain hypersensitivity in a segmental distribution negatively impacts functional capacity and most aspects of quality of life. Hyperalgesia of central nervous origin that can be detected by combined pressure pain thresholds measured by a pressure algometer over the patellar tendon, at S2 subcutaneous dermatome and at the adductor longus muscle are the best predictors for pain scores rated at a visual analogue scale, Western Ontario and McMaster Universities Osteoarthritis Index, accounting for 61% of those scores in patients with chronic pain and knee osteoarthritis. Pain related changes in activation of brain circuits such as the limbic and the somatosensory cortex can be identified using functional neuroimaging techniques.
Patient profiling including functional neuroimaging, algometric measurements and biochemical profiling of circulating cytokines, chemokines and growth factors may detect functional, morphometric and chemical changes that serve as translational mechanistic pain biomarkers.