Chronic Pain: We Should Not Underestimate the Contribution of Neural Plasticity
Disability associated with chronic pain is a prevalent worldwide problem. Much of our understanding of how and why chronic pain develops has been provided through developments in neural imaging and assessment techniques. Such investigations have highlighted the substantial amount of neural plasticity, or neural reorganisation, that is possible within the nociceptive system. While this plasticity is often physiologically beneficial and usually reverses over time, persistent plasticity can occur following long term activation or damage to the nociceptive system. These adaptations are associated with the development and maintenance of chronic pain conditions. This review provides an outline of the nociceptive system and describes the evidence for plasticity of the system at peripheral, spinal, and supraspinal levels. A number of clinical symptoms associated with chronic pain are described along with the possible neural mechanisms that may contribute to the presentation. Finally, chronic pain management approaches that promote reorganisation of the nociceptive system are discussed. These include sensory training, non-invasive brain stimulation, and mechanisms-based treatment.