Chronic pain and the thoracic spine

Abstract

In recent years there has been an increased interest in pain neuroscience in physical therapy.1,2 Emerging pain neuroscience research has challenged prevailing models used to understand and treat pain, including the Cartesian model of pain and the pain gate.2-4 Focus has shifted to the brain's processing of a pain experience, the pain neuromatrix and more recently, cortical reorganisation of body maps.2,3,5,6 In turn, these emerging theories have catapulted new treatments, such as therapeutic neuroscience education (TNE)7-10 and graded motor imagery (GMI),11,12 to the forefront of treating people suffering from persistent spinal pain. In line with their increased use, both of these approaches have exponentially gathered increasing evidence to support their use.4,10 For example, various randomised controlled trials and systematic reviews have shown that teaching patients more about the biology and physiology of their pain experience leads to positive changes in pain, pain catastrophization, function, physical movement and healthcare utilisation.7-10 Graded motor imagery, in turn, has shown increasing evidence to help pain and disability in complex pain states such as complex regional pain syndrome (CRPS).11,12 Most research using TNE and GMI has focussed on chronic low back pain (CLBP) and CRPS and none of these advanced pain treatments have been trialled on the thoracic spine. This lack of research and writings in regards to the thoracic spine is not unique to pain science, but also in manual therapy. There are, however, very unique pain neuroscience issues that skilled manual therapists may find clinically meaningful when treating a patient struggling with persistent thoracic pain. Utilising the latest understanding of pain neuroscience, three key clinical chronic thoracic issues will be discussed - hypersensitisation of intercostal nerves, posterior primary rami nerves mimicking Cloward areas and mechanical and sensitisation issues of the spinal dura in the thoracic spine.

Keywords: Chronic; Neuroscience; Pain; Sensitisation; Thoracic.

Figure 1.

Anatomical considerations of the intercostal and posterior primary ramus nerve supply in the thoracic spine.

Figure 2.

Development of an abnormal impulse generating site. A – axon with myeline intact indicating normal distribution of ion channels in unmyelinated regions in a typical axon. B – increased number of ion channels inserted into the axolemma of an injured axon with demyelination.

Figure 3.

Composite image showcasing the overlap of cervical disc and cervical zygapophyseal pain referral patters over the superficial posterior primary rami nerves.

Figure 4.

The continuum of the human nervous system.