Your nervous system, including the brain, coordinates your mind and body—it adapts and responds to everyday experiences, which helps you to survive, grow, adapt and function. The nervous system is sometimes thought of as'hard-wired', but it is in fact 'plastic'1,2 and can readily adapt to changes in your body and the surrounding environment.
The ability of the brain and nervous system to adapt and change is called 'neuroplasticity'.
Neuroplasticity can be helpful and not-so-helpful!
We all experience helpful neuroplasticity every day of our lives, where our nervous system learns and adapts and this frees up brain capacity for other functions. Examples of helpful neuroplasticity include driving home on 'automatic pilot' without needing to use a GPS, remembering how to ride a bike (muscle memory), or switching-off traffic noise after a few minutes standing on a busy street corner.
But there are also downsides to neuroplasticity, and developing persistent (chronic) pain is an example1,2. Here, neuroplasticity makes the brain and nervous system super-sensitive and hyperactive to otherwise normal sensations and activities - just like turning-up the volume on a loudspeaker. Normal tasks become painful when they shouldn’t be. Psychological and physical stress often triggers this unhelpful neuroplasticity, which can lead to or exacerbate persistent pain2,3. However, there are therapeutic approaches that can train the brain to reduce chronic pain 2,4.
What does this mean for a person with persistent pain?
In acute pain (such as hitting your thumb with a hammer), the brain produces pain 'alarm signals' warning us of damage to our body: this is a helpful alarm and is designed to protect us and favour healing. This is good biological design that helps us to survive. The brain and nervous system have evolved over millions of years to amplify and memorise these alarm signals so we don’t ignore them and to link them with any associated surrounding danger. This is where the context of the alarm can become important: what position was I in when I hurt myself?; I remember that the stove is hot and if I touch it, I can get a burn. People born with the rare condition of pain insensitivity die at a young age because they don’t realize they’ve been injured until it’s too late.
However, in people with persistent pain, the brain and nervous system can go into overdrive and become super-sensitive—this kind neuroplasticity is called 'central sensitisation' (or 'wind-up')5. The immune system is also thought to be involved in this process6.
A super-sensitive nervous system and immune cells (called 'glia') release chemicals which 'turn up the volume', increasing the number of connections and signals whizzing around in the brain and spinal cord. Because of this ‘turned up volume’, pain may be felt during activities and movements that should not normally provoke pain. Pain may even be felt without moving but just by thoughts alone. Sometimes pain may also spread to other parts of the body.
In people with persistent pain, central sensitization means the alarm 'keeps on ringing' and that pain 'memories' can persist long after the original cause of the pain has healed. People experiencing persistent pain can experience a memory or 'echo' of their original pain. This explains why people can experience pain when an x-ray or scan looks 'normal', or why a person with an amputated leg feels 'phantom pain'. All of this doesn’t mean there’s anything wrong with your nervous system if you have persistent pain (there’s no problem with your 'hardware'): persistent pain is best thought of as a glitch in the 'software programme' that processes danger signals in the body and which the brain interprets as pain. Sometimes this happens along with memory of the original injury or event that caused pain, and these memories become intertwined. For example, you might experience fear and pain with a certain movement.
The good news is that pain management can use helpful neuroplasticity to help re-programme the way the nervous system responds to danger signals and how the brain interprets this as pain4. The aim of pain treatments is to reduce central sensitization, decrease pain, favour normal movement and daily activity and restore well-being. Examples of using this plasticity in treatments for persistent pain include using 'mirror therapy' to treat phantom leg pain, taking pregabalin (Lyrica™) to decrease nerve sensitivity in nerve-related shingles pain, using mindfulness-based stress reduction (meditation or yoga) to help manage fibromyalgia or re-educating movement without the association of fear. Pain management is all about using helpful neuroplasticity to re-programme and reduce the over-active danger signals in the brain and nervous system. What each individual needs for helpful re-programming may be different and researchers are currently exploring new treatments using plasticity4.
Unhelpful neuroplasticity (central sensitisation) is one of the main reasons why people develop persistent pain2. Unusual painful sensations called 'allodynia' (Greek for 'other pain'), are common with persistent pain and may include:
- pain caused by normal everyday activities (bending, lifting, sitting, running, playing sport, working)
- pain caused by sensations that don’t normally hurt; such as clothes or bed sheets brushing the skin over a painful body area, cold air blowing on a body area (air conditioning), gentle pressure (a hand shake) or movements that are usually pain-free such as back stretches (if you over-stretch an already painful low back, it can REALLY hurt).
Apart from persistent pain, the negative effects of unhelpful neuroplasticity and central sensitization can include: withdrawing from valued activities like work or sports, poor sleep, low energy levels, low mood, negative and unhelpful thoughts, loss of control, increased stress and sickness behaviours, and being less able to care for yourself or others. These responses are not your fault, but are unhelpful when trying to recover from persistent pain, so it is important to seek help to address these issues.
The pain itself can soon become a major and unwelcome focus for our attention. The more concerned and distressed we are about our pain (or our partner’s or child’s pain), especially if we interpret the pain as harmful, the more pain dominates our thinking. In persistent pain it’s almost as if, the more we don't want pain, the more the brain calls our attention to it.
What can you do?
- learning ways to manage the stress response and reduce the focus on pain helps you to manage and function better
- movement, exercise, physical activity done in a sensible and 'paced' way can help reduce pain hypersensitivity
- some pain medications may help to decrease hypersensitivity in your nervous system, however opioid (morphine-based) medications can actually make pain sensitivity worse
- new creative hobbies or practices (like photography or meditation) help you to use the positive aspects of neuroplasticity to calm and 're-wire' NON-painful nervous system connections
- learning to manage feelings of distress and decrease your focus on persistent pain is vital to improving function and returning to normal activities
- in persistent pain, improving your function may require you to re-train the way in which your mind and body interprets and responds to pain
- Pelletier R, Higgins J, Bourbonnais D. Is neuroplasticity in the central nervous system the missing link to our understanding of chronic musculoskeletal disorders? BMC musculoskeletal disorders 2015; 16: 25. [PubMed]
- Siddall PJ. Neuroplasticity and pain: what does it all mean? The Medical journal of Australia 2013; 198(4): 177-8. [PubMed]
- Pelletier R, Higgins J, Bourbonnais D. Addressing Neuroplastic Changes in Distributed Areas of the Nervous System Associated With Chronic Musculoskeletal Disorders. Physical therapy 2015. [PubMed]
- Moseley GL, Flor H. Targeting cortical representations in the treatment of chronic pain: a review. Neurorehabilitation and neural repair 2012; 26(6): 646-52. [PubMed]
- Woolf CJ. What to call the amplification of nociceptive signals in the central nervous system that contribute to widespread pain? Pain 2014; 155(10): 1911-2. [PubMed]
- Grace PM, Hutchinson MR, Maier SF, Watkins LR. Pathological pain and the neuroimmune interface. Nat Rev Immunol 2014; 14(4): 217-31. [PubMed]
Our pain management training modules have been designed to help you start this re-training process and get some tips. You don’t have to do this on your own. The training modules have been developed to complement working with your health professional team.
If you're seeking further information contact your local GP for further assistance to better manage your pain.