The role of the nervous system in the experience of chronic pain
The nervous system is made up of basic units called neurones.
Neurones form networks and this video will show you how signals - which are chemical and electrical in nature - create pathways in the brain. There is a nervous system pathway for every experience, including pain and understanding that it is a complex with many components is helpful. If you have had a traumatic experience in relation to your pain, that trauma experience will become a part of your pain pathway (see section on Trauma)
If you live in chronic pain it is important to know that your nervous system changes in response to pain, and can become somewhat unpredictable when viewed traditionally. The process is called "Central nervous system sensitisation" and it causes the pain experience to become a highly distressing, misunderstood, little explained "snake eating its tail" situation where things can progressively deteriorate.
Your thoughts, feelings, and movements are all players in exciting or inhibiting Central nervous system sensitisation. There are chemicals that are associated with thoughts, feelings and emotions, and some of these calm down the system, some of them excite the system.
The pain experience is related to activity in ascending, central and descending processes of the central nervous system (spinal cord and brain).
Ascending fibres from the body to the brain
- They transmit messages to the brain about damage or threat in the tissues
- Signals can also come to the brain about the health of the nerves themselves. This is called neuropathic or neurogenic pain
- In the spinal cord the central nervous system can become highly sensitive to stimuli from both within and outside the body. This process is referred to as Central Nervous System Sensitisation.
- In this situation, the ongoing pain has a lot to do with the process of nervous system adaptation. It is like the nervous system becoming a very sensitive and high quality amplifier.
Descending Fibres from the brain to the body via the spinal cord
- This involves the sympathetic nervous system (fight or flight),
- Also involves the parasympathetic (rest and digest), endocrine (hormone production), immune (defence) and motor (movement) systems. All of these nerve fibres will make a contribution to the pain experience.
Lorimer Moseley explains the nervous system and pain
How do we know how the nervous system works and what is going on in the brain?
Most of the information we hear about is theoretical, however there is some really interesting information emerging as a result of a technique called "Functional Magnetic Resonance Imaging" which shows pictures of the brain while we are having an experience of some kind.
Here is Dr Christopher DeCharms talking about this technology.
Central Nervous System sensitisation