Last week we discussed the areas of the brain that are involved in how we process pain as they were identified on functional MRIs.
Together they are known as the pain matrix:
- Primary somatosensory cortex
- Secondary somatosensory cortex
- Anterior cingulated cortex
- Insular cortex
- Prefrontal cortex
- Thalamus
Not only are these different parts of the brain activated by signals the body perceives as dangerous, but the MRIs also showed “smudging” or blurring of the lines between the motor and sensory responses can also occur, allowing other areas to be recruited.
This makes defining exactly where the pain originated and continues to persist difficult. The brain’s ability to adapt to massive amounts of stimuli and ultimately change how we perceive them may be the answer. This is called neuroplasticity.
Nueroplasticity
This is the brain’s way of continually adapting to various stimuli. Nerve pathways can be physically altered by reducing or increasing the number of connections. Or they can alter how many neurotransmitters are released- more stimulating neurotransmitters means more nerve activity, which can then increase the sensitivity of the entire system. In chronic pain syndromes, damage to nerves can actually cause the central nervous system to reorganize and create abnormal connections that often increases pro- nociception and impairs anti- nociception responses.
Long term inflammation also heightens sensitivity. Here, it requires less stimulation to send the danger signals and the rate at which the nerve fires increases. The volume of danger messages becomes overwhelming, causing the nervous system to jump to high alert by using its most protective mechanism- pain.
Perception
Increasing evidence shows it’s not just the number of messages the brain receives from the periphery that determines what we feel, it can also be influenced by how we view those messages. Probably because the pain matrix involves areas of the brain that deal with emotions, behaviors and thoughts. If we believe the danger signal isn’t warranted, we can decrease the pain. As related in past posts, we can also distract ourselves from the pain.
The Neuro Orthopedic Institute (NOI) group published data regarding their theory on pain and how to control it through assessing the DIMs, dangers in me, versus the SIMs, safety in me. They established a protectometer, a diagram that helps individuals to understand and better manage pain. First by increasing awareness of what might worsen pain through DIMs e.g. work, marital issues, financial stressors, medical diagnoses. And those they label SIMs e.g. loved ones, friends, travel, successes.
They believe if the scale tilts towards the DIMs, pain escalates, towards the SIMs, pain lessens. Which makes sense. We hurt more when we are scared, sad, angry, or worried. And less when we feel happy. Increasing the feel-good side should improve pain levels. That’s why going out with friends, exercising, and meditation. . .are proven resources for pain control. Looking at triggers that can promote pain and removing them from our lives is a great start. They also encourage looking into different categories in your life to see how they affect your pain.
Things you do.
Things you think and believe.
Things happening in the body.
People in your life.
Things we hear, see, taste, touch.
Places we go.
The authors believe,
“There will be more pain when your brain concludes there is more credible evidence of danger in me than there is credible evidence of safety in me. The overall goal to self-manage the pain is to effectively decrease DIMs while increasing SIMs.”
There’s also a gate control theory.
This is a more physical response to pain. Ever bumped your elbow and hit the nerve there, then without thinking started to rub the pain away? Sounds crazy. But the gate control theory says non painful stimuli such as pressure can block or even override the danger messages and lessen pain. Why? Because the nerves that send data on pressure are actually faster and more effective than those that alert us to danger! Probably why a good massage helps. It not only stimulates the release of feel -good hormones but promotes anti- nociceptive vs pro- nociceptive responses as well.
The more we know about pain the better we are able to find ways to combat it. All the changes discussed above are due to the plasticity of the neural system and the brain. It is through this very plasticity that we may be able to target treatments for relief. This is why distraction techniques and mechanisms to release our own feel-good hormones work. The more they’re used, the more the brain will learn to decrease pain signals and lessen pain.
-https://www.sciencedirect.com/science/article/abs/pii/S0301008210001759
-https://www.scientificamerican.com/article/the-battle-over-pain-in-the-brain/
-https://www.physio-pedia.com/Chronic_Pain_and_the_Brain
-https://pubmed.ncbi.nlm.nih.gov/21040755/
-https://www.simplewellness.com.au/blog/can-the-pain-matrix-explain-your-chronic-pain#:~:text=What%20is%20the%20Pain%20Matrix,how%20intensely%20we%20feel%20pain.
-https://jamanetwork.com/journals/jamaneurology/fullarticle/2516854
-https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5125472/#:~:text=They%20are%20asked%20to%20identify,of%20hitting%20the%20pain%20threshold.
-https://thebrain.mcgill.ca/flash/a/a_03/a_03_cr/a_03_cr_dou/a_03_cr_dou.html
-https://www.noigroup.com/noijam/dim-sims/