Rheumatoid Arthritis and Fibromyalgia: A neurological perspective
When working with a large number of patients with chronic pain and illness, you begin to notice patterns in relationship to certain illnesses. One of the more common trends I see today is the association between having an inflammatory illness like rheumatoid arthritis along with widespread body pain like fibromyalgia.
Rhumatoid arthritis and fibromyalgia share some commonalities in that they disproportionately affect women more than men, are associated with flare ups of increased pain intensity, and are chronic illnesses with no cure. Although they are separate and distinct health issues, it seems that if you have an inflammatory illness like rhematoid arthritis, 10–15% of these patients are likely to report the widespread body pain of fibromyalgia. Let’s see if we can break this phenomenon down.
Rheumatoid Arthritis and Inflammatory Illnesses
Rheumatoid arthritis falls into a class of inflammatory disorders where flare ups of inflammation can create damage to joints throughout the body. The pain from these flare ups can be debilitating, and the damage done to the joints can be quite severe when left untreated.
Notice the deformity of the thumb and index finger on the right hand. CanStock Photo
The damage to these joints is caused by an autoimmune reaction. Autoimmune disease is a condition where the body’s own defenses inadvertently create harm to the body itself. In the case of rheumatoid arthritis antibodies can build up in the joint spaces and cause other immune cells to create an inflammatory reaction in the area. This is where people can feel the heat, swelling, and pain that is known to occur in flare ups.
Patients with rheumatoid arthritis tend to have arthritic flare ups affect joints like the hands, toes, and neck. However, they are also more prone to wide spread pain in other regions not associated with arthritic breakdown. Why would pain exist in an area that is not associated with inflammation and destruction of the joint?
Chronic Pain: Central Mechanisms
Pain is an extremely complex phenomenon. We generally think of pain having a direct relationship to tissue damage. When we get a cut, sprain an ankle, or break a bone we expect that pain will occur because of the injury. Therefore it’s not surprising that the pain and destruction from a rheumatoid arthritis attack to be very painful.
However, we also know that pain can occur long after an injury has healed, and even in the absence of injury whatsoever. This is what happens in patients with the widespread pain of fibromyalgia. People with fibromyalgia often have nothing to point to as a cause of their pain. It’s an enigma that makes chronic pain syndromes so frustrating because they have no test or image to prove why they feel so poorly.
Many suspect that this widespread body pain may be from dysfunction at the level of the central nervous system. In normal circumstances, the brain has a few ways of controlling how much pain it will feel. This ensures that our bodies don’t overreact to normal everyday stimuli and interpret as painful.
One mechanism is by pain inhibition. Pain inhibition involves the brain using it’s own pharmacy of pain killing chemicals to stop a pain signal from going up the spinal cord.
Pain can be inhibited by chemical pathways inherent in the brain.
Studies on patients with rheumatoid arthritis have shown that the brain’s ability to inhibit pain becomes compromised leading to an increase in pain with normal stimulation. [Source]
When your brain has difficulty inhibiting pain, then you begin to feel it in places where there’s no injury
Another way that the brain can modulate pain is through a concept known as the pain gate. The pain gate operates on the idea that pain has to hit a certain threshold for it to be consciously perceived in the brain. In this way, it allows the brain to ignore things that aren’t causing much damage or risk.
In a perfect system, you would only feel pain when you have actually created injury or are under imminent threat of injury. However, this appears to be another mechanism that gets disrupted in chronic pain patients. When people have chronic pain, it probably means that the gate that is meant to block most of your pain is letting everything in.
Does Rheumatoid Arthritis Break This System Down?
The main treatment for inflammatory arthritis focuses on managing inflammation. Most patients with this type of arthritis will take a wide variety of anti-inflammatories that cover a wide spectrum. They include drugs that specifically target the inflammation associated with RA like Trexall, immune modifying biologics like Humira, and go all the way down to non-steroidal anti-inflammatories like ibuprofen.
In many of these cases, the inflammatory pain of arthritis is under control by these drugs, yet the widespread body pain persists. We don’t really know how or why these inflammatory disorders can lead to pain sensitization, but studying other acute pain conditions may give us some clues.
Studies done on patients with acute pain from a traumatic injury and post-surgery pain issues. When someone suffers from the pain of a major injury, the neurons associated with the pain response start to fire more frequently to guard against the area of injury. This is only supposed to be a short term response to significant injury, but in some cases these changes become persist through a phenomenon known as plasticity. When these spinal cord neurons stay hypersensitive, it means that a person’s nervous system will become hypersensitive to the pain response. [Source]
While inflammatory arthritis isn’t necessarily an injury in the classic terms, make no mistake that inflammation can create a significant amount of tissue damage when it goes unchecked.
Making Your Nervous System Less Sensitive
If the nervous system can be made more sensitive by persistent pain, can it work in the opposite direction? A lot of the research on pain has been focused on targeting these mechanisms which has lead to a higher usage of opioid medications. The obvious problem is that opioids are highly addictive and has become a major public health issue.
There is a growing need for non-pharmacologic interventions to address these chronic pain issues, and fortunately there are some that can be really effective. In cases of chronic pain, the best approach is one that addresses a person from a mental and physical standpoint rather than chasing after a holy grail treatment.
When you look at the pain gate theory image, you can see that the factors that impact your pain threshold include brain and spinal input which exercise and chiropractic adjustments can play a major role. Things like memories, emotions, expectations, and attention are all factors that can be changed with neuropsychological therapy. Out of that entire list, everything except your genes are modifiable factors.
Our approach to chiropractic is focused on the head and neck, which has been shown in at least one study to improve long term outcomes in patients with fibromyalgia syndrome when combined with exercise and cognitive based therapy. You can read more about that in a previous article below:
At the end of the day, there is no cures for rheumatoid arthritis or fibromyalgia yet. There may not be cures for years to come. However, many people with these illnesses can see their quality of life improve by addressing some of the neurological consequences of the disease.