People in chronic pain are hopeless and feel misunderstood and abandoned. They are depressed and desperate. It is estimated that 1.5 billion people worldwide suffer from chronic pain. Supposedly 100 million Americans have persistent pain and 25.3 million people suffer from pain daily. The quality of life is diminished for these patients and they develop anxiety over it.
Pain is a unique experience for the individual. The doctor treating the pain needs to understand the mechanisms of what is causing the pain. Chronic pain does not equal tissue damage. For example, you can have a lot of arthritis and not feel it. Or you can have a small pimple and it really hurts. Chronic pain is being generated by our brain. If your arm was injected with Novocaine and then set on fire you would not feel it. Not until the chemical that was blocking pain transmission along a C nerve fiber wore off. Our bodies have many mechanisms to squelch down pain signals from reaching the brain and if they do, it has more mechanisms for coping with it.
When a patient presents with pain, the practitioner needs to consider whether it is physiologic pain or pathological pain. If physiologic is it somatic pain, visceral pain, inflammatory pain, muscle pain. These types of pain are created by pain receptor activation. Our bodies are riddled with all kinds of special nerves or nerve endings that are activated by noxious stimuli such as physical and chemical traumas. Somatic pain is triggered by these nociceptors (nociceptors is a general category for all the different kinds of receptors for pain) in the skin, muscles, joints, and tendons and that is the kind of pain that you can localize.
Visceral pain is more complicated and it comes from activation of nociceptors in our internal organs and these nerves are not as well spatially delineated in the brain so it is hard to know where it is coming from. We heard of referred pain. For example, you are experiencing pain in your left arm, but your left arm is fine, you are only having a heart attack. These types of referred pain are explained by our embryological development. When we were all folded up as a tiny embryo nerve pathways developed at the same vertebral levels.
While it is important not to have a heart attack, many people that think they are having one are told at the E.R. that they are not and that they should just take some pain killers for that left arm pain. That is a good time to see the chiropractor because the vertebrae that has nerves going to the heart region also has nerves going to your arm. In fact, that is how I became a chiropractor. That scenario happened to my father. When the doctors could not help him with his left arm pain and the chiropractor got rid of it immediately it was at that moment that he knew his 2nd son had to become a chiropractor. Now back to our regularly scheduled program.
Inflammatory pain is nociceptor activation from tissue damage and immune cell infiltration. Muscle pain is activation of alpha motoneurons resulting in contraction. With these 4 categories of pain the goal would be to over ride them. I’m now going to explain how we over ride them. There are 3 basic nerve cables in our bodies titled, A, B, and C fibers. The C fibers are what transmit pain. They are the smallest slowest nerves in the body. They are the slowest because they are the smallest. In other words if I want to get downtown, I can take the freeway, which is the largest road there and if no traffic, I can move faster on that large highway. I could also get there by taking a large road with traffic lights on it. I could also eventually get there by going down alley ways. The nerves chiropractors work with are the A nerves and they are the largest most powerful nerves. The signals traveling on those nerve highways are going to the brain much faster than the pain signals on the puny little highway, the C fibers. The signal from the A fibers arrives at the Thalamus, which is where all these 4 categories of pain signals must arrive in order to know something is hurting. This means it takes the pain signals parking space temporarily. This is what I referred to earlier as squelching down the signal. When you do yoga or just exercise, you are firing these pathways that inhibit pain. Most people that hurt, automatically stop moving and this is what helps rewire the brain into a permanent pain state.
Pathological pain can be neurogenic pain or pain from a tumor or some type of pathology. This pain is without pain receptor activation. So all that stuff I just talked about above is not too relevant for this. Again, physiologic pain is receptor dependent and pathologic pain is not. Things like Fibromyalgia, Parkinson’s, psychological conditions, genetic disorders, are examples of pathologic pain. These patients nerves are sensitized and have a heightened response to ordinary stimuli. Pathologic pain is due to a lesion in the central nervous system that needs to be addressed quite differently than physiologic pain.
With that in mind, when a patient points to a body part and says it hurts here, it doesn’t really give us a whole lot of information. Is it acute or chronic? Acute pain is is triggered by a stimulus. This pain does not persist for more than 3-6 months. It acts as a warning signal that you are injured such as with a sprain, trauma, lacerations, etc.
Chronic pain is considered a disease state. It persists for 6 months or more. There is no recognizable cause. It comes and goes and the patient has no idea when it will be triggered and is worse on some days than others. Acute pain is triggered by a specific event, chronic pain is a signal generated by the brain in response to what it perceives as a high level threat. The brain releases chemicals that affect the body, it is a top down mechanism which is the opposite of sitting on a thumb tack. There the pain is literally generated at your bottom and it heads up from there. Chronic pain is hard to understand because it is not reproducible. In med school we are taught for a very long time orthopedic tests that are created to reproduce a patients pain in order to diagnose what it is. Most practitioners figure out after a few patients that these tests are not all that useful in many situations.
When a patient’s pain is from central sensitization (coming from your brain), things can get ugly as in the 64,000 people that died last year from opioid prescriptions. But before we get killed by medicine this kind of pain is affecting our limbic system, which is the portion of our brain that triggers emotions. One part of this system is the Amygdala and it is responsible for fear and avoidance. This part of your brain can run wild and can create catastrophic thinking. This is where an emotional value of our pain starts. Not all pain is the same. We all have less tolerance to certain types of pain. For me, it is a neurogenic radicular type pain. In my case it is being generated by perhaps an invisible micro millimeter of pressure on a nerve, but it is the kind of pain I cannot stand. Fortunately it happens maybe twice a year and I know how to get rid of it. Compare that to the visibly apparent large amount of physical destruction of my right knee. Orthopedics do not believe I can walk on that leg. It always hurts yet it doesn’t bother me at all. This is what the textbooks mean that pain is a very personal experience.
Chronic pain signals directly effect the somatic maps of our brains, which are the areas of our brain that let us know what our muscles are doing. As I’m typing I’m aware that my fingers are on the keyboard and I can tell how much pressure is on my finger tips. There is a big part of our brain that keeps us aware of what our limbs are up too. At the same time, these pain signals are hitting our Hypothalamus, Pituitary, Adrenal axis and if you have been reading my articles you know that means that you are creating stress hormones. One of the bad things about that is increased cortisol means decreased digestion and that results in poor health. This is when I usually state that a chiropractic adjustment directly affects the hypothalamus and lowers the output of stress, but I’ll skip over that today. What is important here is to realize that our brains become hypersensitized. Chiropractors are not back doctors, we are brain doctors, our treatments directly affect the brain.