Mechanisms of peripheral neuropathic pain: implications for musculoskeletal physiotherapy

Physiotherapy has long been part of the overall intervention for the attempted rehabilitation of patients with pain and disability following peripheral (and central) nerve damage. In musculoskeletal physiotherapy (a subspecialty), a movement-based assessment and treatment protocol has been devised that is guided by, among other things, therapists' perceptions of patients' responses to mechanical stimuli, including various tests of 'neural tension'. Recently, this process together with provocative tests of sensation has been employed to identify, and predict outcomes for, patients suspected of having a 'neural tissue' component to their pain and consequent disability (either fascicular damage or 'neuritis'). However, some of the syndromes involved are controversial, and uncertainty still surrounds the diagnosis, mechanisms and, therefore, effective treatment of the highly complex symptom, true neuropathic pain. In this review, the current basic scientific evidence for the proposed cause, and often intractable nature, of neuropathic pain is presented and discussed with reference to musculoskeletal therapy. It will be seen that peripheral nerve damage has the potential to create potentially irreversible changes in (peripheral and) central nervous system structure and function that have, to date, largely defied effective medical treatment. For musculoskeletal physiotherapy to discriminate accurately and, where appropriate, intervene (or not) responsibly, it would seem constructive to incorporate this (and other) mechanisms-related evidence into its clinical reasoning and decision-making process.