Everyone has experienced pain at one time or another. But pain is personal – each of us experiences pain differently. Some of us feel it very intensely, and others not so much. This is because pain depends not only on what happens to your body, but also how your brain responds to it. This is what is known as the Pain Matrix.
What is the Pain Matrix?
This matrix processes information from the nerves that tell us when we’re in danger or injured. It responds by increasing or decreasing our sensitivity to these messages. These changes – known as top-down regulation – control how intensely we feel pain.
The Pain Matrix involves different areas of the brain that control emotions, behaviour, movement, perception and thoughts. So it’s no surprise that when you’re in pain, all of these different factors can change.
How does the Pain Matrix work?
There are two main changes that the Pain Matrix can induce. Anti-nociception is a reduction in sensitivity to pain, whereas pro-nociception is an increase.
Anti-nociception uses the body’s natural painkillers – endorphins – to block the danger signal and decrease the pain response. Ever seen someone injure themselves in a dangerous situation, like in a car accident, but they can still move to safety without feeling pain? This is because a rush of endorphins temporarily blocks out the message of danger so they can get to safety.
On the other hand, pro-nociception is usually due to swelling and chemical changes in the nerve endings around an injury. Have you ever had a bad paper-cut? Your sensitivity is much higher around the cut, even if you’re not touching the injured part. Sometimes, even moving the other fingers can hurt.
Changes in the brain = changes in the pain
Despite what we used to believe, the brain can continually change its form and function as a form of adaptation. These changes are known as Neuroplasticity. Nerve pathways can physical alter by increasing or reducing the number of connections. Or they can alter the release of neurotransmitters – more stimulating neurotransmitters means more nerve activity, which can increase the sensitivity of the system.
When it comes to chronic pain conditions, the central nervous system is reorganised. This can include damage to nerves, leading to abnormal connections between them. Pain is more likely to occur than not, as pro-nociception increases and anti-nociception is impaired. This can lead to exaggerated responses to pain including pain caused by non-painful experiences - this is known as allodynia, and can be a common symptom in conditions like Fibromyalgia.
Long term inflammation can lead to a heightened sensitivity of the nervous system. In the presence of inflammation the amount of nerve stimulation needed to send the signal decreases and the nerve firing rate increases. With so many danger messages coming in when there is inflammation present, the nervous system starts to respond on high alert by using its protective mechanism - pain!
Controlling the pain
There is no one size fits all approach to controlling pain, but theres increasing evidence that changes to pain intensity can be influenced by more than just the incoming messages from our tissue - it can also be influenced by our perceptions of danger and safety. This is likely due to the pain matrixes involvement in areas of the brain that deal with emotions, behaviours and thoughts. Pain experts Dr Lorimer Moseley and Dr David Butler of the NOI Group have published a fantastic book called Explain Pain that describes DIMs and SIMs - that is, Danger In Me (DIMs) and Safety In Me (SIMs). They say that any credible indication of danger can increase your perception of pain, and likewise a credible indication of safety can decrease the pain. We'll dive deeper into this research in future blogs.
The Gate Control Theory involves a more physical approach to pain control.
Have you ever bumped into something, then rubbed the area to make it hurt less? The Gate Control Theory is that non-painful sensations such as pressure can block or override the danger messages and reduce pain. The nerves that tell us about pressure are faster and more effective than those that tell us about danger. This might be part of why something like a good massage session helps with pain. Massage is also a great way to stimulate some feel-good endorphins, which promotes anti-nociception to reduce painful sensations!
If you’re looking to minimise your pain, a combination of massage, exercise therapy and other myotherapy treatments can help. Have a look at my online booking calendar to book in for an appointment.
Mel is a Myotherapist based in Ferntree Gully.