Buckle up for a nerdy post, Renegades.
We talk ad nauseam about understanding pain. This subject is important to us, because no matter how often we discuss pain science with our patients, there are always a handful of people who say the same thing.
“So you’re saying that the pain I feel is all in my head?”
Technically, yes, it is. However, the context of how patients mean it, and the context of how we mean it, is very different. “Pain in your brain” does not mean that your brain is producing pain out of thin air. It doesn’t mean you’re weak or that your pain isn’t credible. Everyone who experiences pain does so in the brain, because that’s where information is interpreted. Without the brain, we can’t interpret sensations from the body. It’s similar to an unopened piece of mail. We know there’s a message, but wouldn’t know what’s inside without the brain. The brain opens the mail.
We’d like to investigate how sensations are interpreted as pain in the body in two situations. One: a non-magnified, “normal” pain interpretation. Two: A chronic pain situation, in which non-threatening sensations are magnified into pain. This occurs in conditions like chronic neck pain, chronic low back pain and fibromyalgia, to name a few.
Situation one: the pain experience
I love this artistic representation of pain by René Descartes back in the 1600s to illustrate the pain pathway. Although the pain experience goes into complex detail, we’ll use this photo to visualize what goes on in your body when pain is experienced. For simplicity, four steps are listed.
- You feel something. The sensation could be a fire. It could be a knuckle sandwich from your best buddy, or a sharp nail on the floor. It doesn’t matter what.
- The signal travels through the nerves of the arm/leg to the spinal cord. The nerves in the spinal cord receive the message.
- The message travels up the spinal cord to the brain, where it is interpreted (that’s why pain is in the brain!)
- The brain sends a signal down in response to the sensation (release adrenaline so the body can move away from the fire quickly, wind up a counter sucker punch for your buddy, or send a painful signal to the foot to quickly shift weight away from the nail). Under normal circumstance, all three scenarios would cause pain.
Easy enough, right? That’s how signals travel up and down the nervous system to interpret possibly painful information.
Situation two: magnification of the pain Experience
Before we begin: Have you ever played the game ‘telephone’? For those who haven’t played before, picture a certain number of people (let’s say 10) standing shoulder to shoulder. The person on the far left whispers something into his/her neighbor’s ear. That person then whispers the message he/she hears into his/her neighbor’s ear. The message travels along the line of people until it reaches the last person in the line. The last person then says the phrase they heard out loud. Almost always, the message the last person says aloud is different from the phrase the 1st person began with.
This same phenomenon can occur in the nervous system with steps 1-3 outlined above. Gentle sensations in step one (pressure from a chair on someone’s back) can be misinterpreted as they travel along the pathway. In cases of fibromyalgia and chronic pain, the sensation is magnified.
Here’s how it can happen:
when the signal reaches the spinal cord (Step 2)
Let’s say the nerves in the spinal cord are overworked. It’s not just your back that hurts; it’s your neck too. The knee you hurt the other day is acting up, and your foot is bothering you. All these signals are constantly sending sensation to the nerves of the spine. Complete overload. In an overloaded spinal cord, a minor stimulus gets magnified. Something gentle, like pressure from a chair you’re sitting on, becomes very intense. This intense signal is then sent to the brain; the brain interprets intense information as painful.
When the signal reaches the brain (Step 3)
Let’s say in step 1 and 2, the sensation remains the same. But then it reaches an overloaded brain. Your boss just gave you a new assignment, you have to pick your car up before the mechanic closes, and you still have to make dinner for your mother, who isn’t feeling well. You’re stressed and sleep deprived. Suddenly, a simple message or task is unmanageable. The brain takes a simple sensation and makes it a big deal due to stress. Pain then occurs.
“Pain in your brain” is a fancy way of saying that the brain is interpreting normal or exaggerated sensory information. It’s not to say that your pain isn’t real, or that you are exaggerating your symptoms. It is to say that there is more at play than just a simple sensation felt at the limb.
Decreasing Pain related to Chronic Pain and Fibromyalgia
What’s interesting is that you can use this phenomenon to your advantage! Once you understand how signals travel in the neuromuscular system, you can decrease signal intensity through reassurance. When we reassure ourselves that the pain we feel is exaggerated and shouldn’t be as painful, we can slowly decrease the amount of pain we feel on a daily basis.
This is not easy as it sounds. It takes continuous practice. It is essential, however, in removing chronic pain from your life once and for all.
Take your body back.
Brendan Glackin, DPT, CSCS
Melzack, R. Pain and the neuromatrix in the brain. (2013) Journal of Dental Education, 65 (12), pg 22-26
G.L. Moseley. A pain neuromatrix approach to patients with chronic pain (2003) Manual therapy 8(3), pg. 130-140