I have discussed the idea that cortical reorganisation occurs among many pain states. The greater the chronicity of pain the greater the neuroplastic changes. Exercise; particular motor skill training in particular can assist in the reversal of such maladaptations.
Towards the end of my previous post I made a comment regarding the pyschosocial factors having have a comparable effect on learning like that of pain.in that under the influence of pain, novel skill acquisition is reduced.
Physiotherapy is moving to a much more psychosocial focused paradigm. I would like to end my blogging experience by touching on the role of pyschosocial factors within neuroplasticity.
It is well evidenced that the experience of pain is shaped by a whole host of cognitive and behavioural factors and that some factors such as fear, anxiety, beliefs regarding pain, avoidance of movement and mood are shown to be prognostic factors in the development of chronic pain (Linton & Shaw 2011).
Image 1. A modern view of pain perception from a psychological perspective according to Linton (2005)
Out with the old in with the new
The body; a large widespread network of neurones that consists of loops between the thalamus and cortex and cortex and the limbic system is an entire network, whose spatial distribution and synaptic links are determined initally by genetics but later sculptured by sensory inputs is termed a ‘neuromatrix’. The ongoing cycle of processing and synthesis of nerve impulses through the neuromatrix impart a characteristic pattern known as the neurosignature. The neuromatrix is genetically progammed to perform the specific function of producing the signature pattern. It is distributed throughout many areas of the brain and generates patterns and processes information that travels through it and ultimately produces a pattern reflecting the whole body.
Appreciatively this view is largely different to the previous notion that the pain experience is proportional to peripheral injury or pathology. Previous pain theories; pattern theory and the pain gate theory have paved the way for this neuromatrix concept.
In persistent pain states there is an associated with overactivity of the pain neuromatrix increased activity is present in a number of cortical areas within the brain; insula, anterior cingulate cortex, prefrontal cortex (Seifort and Maihofner 2009). The amygdala is one key brain area involved in the pain neuromatrix often referred to as the memory centre of fear. It plays a primary role in the processing of memory, decision making and emotional reactions. negative emotions and pain related memories. Evidence through neuroimaging suggests that the amygdala plays a key part in facilitating the development of chronic pain and the increase in sensitivity of the central nervous system pain pathways ( Simons et al 2012).
What does this mean in practice? The significance of this in practice is the recognition of the brain and in particular the amygdala’s role in pain memory. In particular memories of painful movement. The amygdala’s collaboration with the hippocampus and anterior cingulate cortex can explain the display of antalgic postures, gait and altered motor control in chronic pain patients (Nijs et al 2015). This understanding signifies how a patient who has had a previous painful experience that associate’s pain as being harmful can display maladaptive movement without the presence of nociceptive input.
Getting the best out of exercise: changing pain memories
Cognition targeted exercise in patients with chronic pain can be effective in changing pain memories in patients with chronic musculoskeletal pain and centeral sensitisation (Nijis et al 2014). Cognition targeted exercise is an approach that focuses on addressing patients perceptions about exercise through thorough questioning and discussion before during and after exercise. It is an approach that is not time contingent like driving plasticity with icreased number of repetition but symptom contingent (Nijis 2015).
I hope my blog has been purposeful in that when you are next treating a patient with persistent pain you may question, what affect you are hoping to have and where. This may drive how you treat them and consequently facilitate your outcomes.
Thankyou for taking the time to read.
Linton S and Shaw W. Impacet of Psychosocial Factors in the experience of Pain. Physical Therapy 2011;91:700-711
Nijis J, Meeus M, Cagnie B, Roussel NA, Dolphens M, Van Oosterwijck J. A modern neuroscience approach to chronic spinal pain: combining pain neuroscience education with cognition-targeted motor control training. Phys Ther 2014;94(5):730-8
Nijis J, Girbes E, Lundberg M, Malfliet A and Sterling M. Exercise therapy for chronic musculoskeletal pain: Innovation by altering pain memories. Manual Therapy 2015;20:216-22
Seifart F and Maihofner C. Central mechanisms of experimental and chronic neuropathic pain: findings from neuropathic pain: findings from functional imaging studies. Cell Mol Life Sci: CMLS 2009;66:375-90
Simons LE, MoultonEA, Linnman C, Carpino E, Beccera L, Borsook D. The human amygdala and pain:evidence from neuroimaging. Hum Brain Mapp 2012;25:2199