Essentially three different areas of information feed into the neuromatrix. 1. Sensory information from our physical body (skin, muscle, organs etc). 2. Cognitive information from past experiences, memory, mood, anxiety, and attention. 3. Emotional information from the limbic system and homeostatic information (Melzack 2005) The neuromatrix generates the following three functions
a. Perception of pain
b. Action plan
c. Stress-regulation instructions (Melzack 2005)
All these attributes form what is termed the neurosignature of pain. Each person has their own unique neurosignatures which are determined partly by genetics and partly by environmental experiences. (Melzack 2005, 2001, 1999)
Another characteristic of the neuromatrix is that it forms a continuous loop that supplies a steady stream of feedback of awareness and action to each area. (Melzack 2005, 2001, 1999)
The presence of memory in the neuromatrix also allows us to feed-forward or anticipate pain, this helps us avoid danger.(Melzack 2005)
The neuromatrix helps explain hyperalgesia or why the experience of pain sometimes seems out of proportion with the physical injury. Your frame of mind at the time of injury, memory of past experiences and general health influence the neurosignature and therefore the experience of pain. (Melzack 2005, 2001, 1999)
The neuromatrix can also help us explain abnormal pain reactions. Allodynia is pain that arises from a normally non-painful stimulus. When the neuromatrix is active for a prolonged period of time, as in times of stress, the threshold stimulus needed to produce pain is lowered. (Khalsa 2004, Melzack 2005, 2001, 1999)
Central sensitisation is another mechanism that produces abnormal pain reactions; it refers to when the neurons in pain pathways increase their response to stimuli from skin and muscle. (Khalsa 2004, Moseley 2003)
The clinical relevance of this theory is that we now have a clearer understanding of what makes pain and allows us to target interventions at each dimension of the pain neuromatrix (Keefe, Abernethy & Campbell 2005). Treatments although they are applied through the physical body are targeted at the body-self neuromatrix in order to decrease its output (Moseley 2003).
Interventions for pain can therefore be attempts to decrease input from peripheral nociceptors such as inhibiting peripheral nociceptors or blocking synaptic transmission in the spinal cord (Moseley 2003). This can be achieved through traditional pharmacopeia and physical therapy.
Interventions can also aim to decrease input from non-nociceptive elements such as our cognitive beliefs, stress reduction, and emotional reprogramming (Moseley 2003). This can be achieved through education in pain physiology (Moseley 2003), psychological interventions, coping skill training and emotional disclosure (Keefe, Abernethy & Campbell 2005).
To be effective as a clinician a detailed subjective history is required to ascertain past emotional and cognitive experiences that may relate to the current situation (Trout 2004), and what has strategies have worked, or not worked, to decrease pain in the past so we can successfully manage pain in the future.
A patient is someone who consults a medical/allied health practitioner. Pain is what turns a person with a sprained ankle into a patient. The first purpose of pain is to facilitate survival. The second purpose of pain is to facilitate survival in comfort or to optimise quality of life. Pain achieves this by alerting us to the need to seek help, instructing us to avoid danger and promoting rest....