Chronic Pain

Dr. Erin Crossman, ND

Pain is one of the top reasons for visiting a primary care practitioner. It manifests in many forms and is a very personal thing. Sometimes it is hard to distinguish the root of your pain as it can be so intertwined with strong emotions and physical sensations, especially when dealing with chronic pain. Although, explaining pain completely through a tissue-based model is outdated.

 

When discussing pain, there are many contributing factors. The more classic biological explanation involves nociception but that is just one contributor. Nociceptors are free nerve endings with receptors for temperature, movement, and chemicals. They carry information to the brain when a tissue is presented with something potentially dangerous. In the past nociceptors have been labeled as pain receptors. However, this is misleading because even though some sort of nociception is commonly involved in pain, activation of nociceptors are not sufficient or even necessary for pain. There must be other contributors, the experience of pain is multifactorial.

 

Inflammatory mediators made by your immune system contribute to pain in part by modulating nociception. When inflammatory mediators are released, it makes the nociceptor more excitable (often called peripheral sensitization). When you have an initial injury an inflammatory process takes over; you typically experience swelling, redness, and pain. Inflammation as a short term healing process is an essential mechanism for tissue repair. Inflammation can also become a chronic, dysregulated issue where it is no longer healing and contributes to sensitizing the body to pain.

 

Pain is more complex than just damage to tissues. You can have tissue damage without pain – have you ever had a bruise and wondered where it came from? And you can have pain without tissue damage – approximately 30 percent of pain patients show no signs of inflammation or physical injury.

 

Think of pain as a warning signal, although, as mentioned above, the severity of your pain doesn’t always relate to the amount of damaged tissue. Also as pain persists, such as in states of chronic pain, there is less and less of a relationship between pain and the state of the tissue. This abnormal processing can begin in less than seven days after injury. Pain is processed in the brain; how you perceive pain is a learned process. Developing abnormal chronic pain reactions evolve when the mind and body maintain a state of alarm and begin to develop unnecessary warning signals. You can have pain without any physical stimuli, however your brain treats it the same. The longer you experience pain, the better your spinal cord becomes at sending the signals of danger to your brain, even if there is no danger in the tissue. In addition, the longer that warning alarm is going off, it will wake the neighbours, being the surrounding tissues, and these will also become sensitized. Soon the alarm system will become so heightened it may be like a car alarm going off from a gust of wind.

 

When discussing pain, it is especially important to address stress and an individual’s mental and emotional state while focusing on altering views about pain. Pain is highly correlated with stress and emotional distress. Two main hormones related to stress and our “fight or flight” responses are cortisol and epinephrine (also called adrenaline). Consider when heat or a mechanical stimulus activates a nociceptor. If that stimulus is now gone, but there is enough epinephrine around, the nociceptor doesn’t need to be stimulated from temperature or pressure and the warning signal can be activated entirely from the epinephrine.

 

The fear of pain is likely worse than the pain itself. Anything that changes your perception of danger will change your experience with pain. This is because the major correlation with pain is not injury, but instead your perception of a threat to your body. This can be more difficult for individuals who have experienced trauma. Studies show that trauma, especially early-life trauma, can later lead to an altered perception and response to stressors. As the perception of threat occurs in the brain, working at modulating reactions to a perceived threat while decreasing overall fear and anxiety produces a decrease in perceived pain, better mobility and overall quality of life.

 

This shift in how to target and treat pain is by no means easy. However, focusing primarily on physical aspects has shown to be ineffective at reducing pain severity and suffering. For example, when studying patients with osteoarthritis of the knee, the outcomes after arthroscopic lavage or debridement were no better than a placebo procedure. Furthermore, many studies have shown no correlation between low back pain and the degree of dysfunction noted on imaging. In fact, a depressed mood has been shown to be a better predictor of future pain episodes than abnormal findings on an MRI. The incidence of people who have to live with chronic pain is only increasing. This seems backwards given the advancements of modern science. It is clear that these completely physical models are not working and many scientists specializing in pain are aware of this, although it has not reached the level of common public knowledge yet. Currently, and to a patient’s detriment, when pain doesn’t show up on a scan or a test, healthcare professionals may interpret this as the patient being overly sensitive, or it being all in their head. Many people are left feeling afraid, angry, alone, and completely overwhelmed, and this emotional distress will only aggravate their pain.

 

Retraining your pain system to be less protective in time reduces your hypersensitive state and overall perception of your pain. It also gives you greater control over your situation. This is best found through reviewing your current attitudes on pain and potentially reframing your views, optimizing stress management techniques and sleep quality, reducing overall inflammatory load, and supporting movement and activity.

 

There are many ways to work through the above list and there are also many symptomatic treatments to help reduce your pain. Chronic pain does not necessarily have to be a life-long struggle. Talk with your doctor about how you can take steps to retrain your pain mechanisms and improve your quality of life.

 

“We are coming to understand health not as the absence of disease, but rather as the process by which individuals maintain their sense of coherence (i.e. sense that life is comprehensible, manageable and meaningful) and ability to function in the face of changes in themselves and their relationships with their environment.” Aaron Antonovsky, PhD 1987.

 

References:

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2) Deyo, R. A., Mirza, S. K., et al. (2009) Overtreating Chronic Back Pain: Time to Back Off? Journal of the American Board of Family Medicine. 22(1): 62-68. doi:10.3122/jabfm.2009.01.080102.

3) Mosely, L. (2007) Reconceptualizing pain according to modern pain science. Physical Therapy reviews. 12(3): 169-178.

4) Moseley, L. (2017) Tame the Beast. https://www.tamethebeast.org/#contact

5) McCabe, C.S., Haigh, R.C., et al. (2005) Simulating sensory-motor incongruence in healthy volunteers: implications for a cortical model of pain. Reumatology (Oxford) 44(4):509-16. DOI:10.1093/rheumatology/keh529

6) O’Sullivan, P. (2005) Diagnosis and classification of low back disorders: Mal-adaptive movement and motor control impairments as underlying mechanism. Man. Ther. 10(4):242-55.

7) Porges, S.W. (2011) The Polyvagal Theory.

8) Porges, S.W. and Buczynski, R. The Polyvagal Theory for Treating Trauma. The national institute for the Clinical Application of Behavioral Medicine.

9) Sihvonen, R., Paavola, M., et al. (2013) Arthroscopic Partial Meniscectomy versus Sham Surgery for a Degenerative Meniscal Tear. N Engl J Med. 369:2515-2524. DOI: 10.1056/NEJMoa1305189

 

 

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