Chronic Pain 101
Chronic pain management in the United States, and in some ways the whole of western medicine, has been a disaster. The reasons for this are debatable, but a simple look at the opioid crisis, the amount of lost productivity, and the recovery rates make this fact indisputable. Until recently, the majority of research has revolved around procedures in the body (surgeries, injections, etc…) and medications that sedate rather than treat. I don’t mean to be like the surgeons and “blame anesthesia”, but I can’t help but be curious why a field that developed to sedate or block pain during a procedure (acute pain) was the primary field that designed treatments for chronic pain.
As the Neuroscience of chronic pain has developed, we are realizing that it is fundamentally different from acute pain, both with how the brain manages it in the healthy state and how medications work in the chronic pain patient. One only has to ask what is “normal” to see that they are polar opposites. In a normal brain, chronic signals of all kinds (especially pain) are reduced or eliminated over time.
The two main examples of this are the childhood injury, and the slowly developing neuropathy. Many people are injured as a child with a mangled limb or other permanent trauma. For most of them, the mangled limb or injury has little to no pain, even though they can often develop pain in the surrounding tissues that have to compensate for the injury. In slowly developing neuropathy, many patients feel symptoms only when very active on their feet or when laying in bed at night. Some have no pain at all even when there has been severe damage to the nerves. They are surprised that they cannot feel vibration on the exam because their brain has reduced pain signals while the damage developed slowly.
Acute (or recent) pain is managed in the opposite way by the brain. A small injury like a splinter or a stubbed toe will send off alarm bells in the brain making it throb and pound far worse than the actual injury justifies. Depending on the injury, the acute pain can spike at the very start and gradually improve, while with others it ramps up over the first day or so and then settles down gradually. These alarm bells are very helpful in making us aware that the injury has occurred so we protect it, and helps us to remember that what we just did was dangerous.
In Chronic Pain Syndrome, these networks both misbehave. My chronic pain patients will notice bruises and have no idea when they injured themselves, while also having severe pain without any recent injury. While we have many medications that simply sedate these pain networks, they don’t treat the core problem. With recent research, we are learning more and more about that core problem: sensitization. This doesn’t just happen in the brain either. There is Central Sensitization happening in the brain and spinal cord where sensory signals are modified and experienced. There is also Peripheral Sensitization, where signals go back down the sensory nerve bundles making them more active and even changing the chemistry in the affected tissue. In healthy people, these processes help turn on the alarm bell for recent injuries, but in chronic pain syndrome, they amplify old and even mild injury to the tissue.
As the Chronic Pain Syndrome progresses, the problem can spread. Instead of just activating the knee pain, it can start to activate pain signals in the rest of the body, and even turn normal sensory signals into a pain signal. We call this Allodynia (“other pain” in Latin). Maybe the injury is in the knee joint, but you start having muscle or skin pain up in the thigh or down in the calf. This isn’t another nerve injury in many cases, but the combination of nerves becoming hyperactivated and the brain amplifying the signal further.
This is an extremely common medical problem, with tens of millions of people in the united states alone suffering from it. Opiates were the drug of choice for many years, but now we know that opiates make it worse in the long run. In some studies, even an individual dose of morphine created increased chronic pain in animal models. It mostly does this in parts of the pain modifying areas in the brainstem, where the brain makes its own chemical called “endorphins”. Endorphins are also vital in experiencing pleasure, so when opiates cause the brain to stop making them, it can lead to many other problems like depression or apathy.
The other problem is that these patients are found in every clinic, but we study them and talk about them separately. In the Rheumatology office, it is called Fibromyalgia. In the Gastrointestinal doctor’s office, it is called IBS or cyclic vomiting. The gynecologists see patients with the same syndrome, but focus on the “Pelvic Pain” component only. The neurologist may or may not know that many of their migraine patients have the same fundamental problem as the chronic pain patients. Ironically, they have all independently found that Amitriptyline is a good treatment, but they still don’t talk about it as a unified diagnosis.
There are a few groups of patients who seem to be more likely to develop this chronic pain syndrome, but identifying cause and effect is difficult. In my clinic, I often find that these patients had an untreated migraine syndrome in childhood or as young adults. This makes a lot of sense because migraine is already a sensory processing syndrome involving central and peripheral sensitization. There is also a connection with increased flexibility, with many patients having a hyper flexible version of Ehlers Danlos Syndrome (hEDS). Other patients have fainting or other features of a misbehaving autonomic nervous system even as teenagers.
In later posts, I will discuss many of these issues in greater detail, as well as the emotional trauma patients experience trying to seek help in the medical system. I simply hope that patients reading this will begin to get a sense of the problem, how it is the fault of the medical community and not the patients, and to know that help is out there. We have no magic bullet, but we are learning more about the causes of this disorder, and new avenues of treatment, every day. Contact us today if you’d like to have a consult to better understand your chronic pain.
Learn more about the Psychological techniques to Cure Chronic Pain.
