Chronic Pain: Is It Body Or Brain?

It will come as no surprise to chiropractors (or indeed any health-care practitioner) that an alarming number of adults in the western world are chronic pain sufferers. It’s a problem that comes in many forms, from tangible disorders like back pain to more mysterious issues like fibromyalgia, but it usually results in a couple of predictable things: painkillers, and frustration as many chronic pain sufferers are told ‘its all in your head.’

The painkiller ‘solution’ is not without a significant amount of risk, albeit risk most sufferers are happy to take in order to reduce their suffering. Yet some are calling prescription painkiller use a ‘crisis.’ In the USA alone in 2014, there were some 50 deaths per day due to prescription medication overdoses [1]. This is to say nothing of the multiple other side effects tied up with long-term painkiller dependency.

For chiropractors, there is still another concern: our goal isn’t to dull the pain with opioids, but restore optimal function thus allowing the body to heal.

New research gives us some interesting information to ponder along these lines. It appears that chronic pain actually causes neuroplastic changes. New Scientist reports that, “Researchers are starting to tackle the problem by rethinking the root causes of chronic pain. Rather than seeing it as a lingering version of the acute form, they have begun to recognise it as a complex disorder of the nervous system that changes the brain’s structure, chemistry and activity [2].”

Among the issues that may show up along with these changes are depression, anxiety and cognitive difficulties when it comes to emotionally laden or risky situations [3]. Other research shows specific morphological changes in the areas of the brain responsible for pain transmission. Although the specifics tended to differ for each pain syndrome studied, the researcher found that they “overlapped in the cingulate cortex, the orbitofrontal cortex, and the insula and dorsal pons [4]” or structures that are involved in the experience and anticipation of pain.

The author, Arne May, remarked “it seems that chronic pain patients have a common ‘brain signature’ in areas known to be involved in pain regulation.” May later remarked that “the gray matter change observed in chronic pain patients are the consequence of frequent nociceptive input and should thus be reversible when pain is adequately treated [4].”

A recent study in the Journal of Neuroscience looked at patients with hip osteoarthritis, and found that neuroplastic changes (specifically grey matter decreases) were caused by chronic pain, rather than being the cause of it. Furthermore, the research found that such changes were not irreversible and that this may have clinical applications when it comes to improving function and reducing pain. So is it ‘all in your head’? Apparently not. But your head does respond and rewire itself because of chronic pain. In the Journal of Neuroscience, the researchers remarked:

“In our patients we found no meaningful changes in the interim scan after the operation, although one would expect changes following the physiotherapy regimen after the operation. Further studies with more patients and using perhaps an even longer follow-up frame are certainly warranted.

Nevertheless, central to our findings is that changes in nociceptive input and transmission lead to intracortical remodelling and that these changes are not irreversible. These data highlight the remarkable potential of the adult brain to undergo anatomical changes that have a great impact on its functioning.

Improved understanding of experience-dependent changes in cortical plasticity may have vast clinical implications for the treatment of chronic pain, focusing on use-dependent plasticity to improve mobility, alleviating pain, and increasing quality of life [5].”

Once again, the human brain amazes with its ability to change and adapt. As our understanding of neuroplasticity advances, there is hope that we will be able to better apply its benefits to chronic pain patients. In the meantime, nurturing the nervous system to allow it to function more optimally remains an important investment.

 

References

[1] https://www.newscientist.com/article/mg23231013-600-treatment-for-chronic-pain-can-be-lethal-but-there-is-an-answer/?utm_medium=Social&utm_campaign=Echobox&utm_source=Facebook&utm_term=Autofeed&cmpid=SOC%7CNSNS%7C2016-Echobox

[2] Hamzelou, J (2016)”When pain wont quit, retrain your brain,” New Scientist,  https://www.newscientist.com/article/mg23231010-200-when-pain-wont-quit-retrain-your-brain/ retrieved 29 Nov 2016

[3] Vania Apkarian, A, Sosa, Y, Krauss, B, Sebastian-Thomas, P, Frederickson, B, Levy, R, Norman-Harden, R and Chialvo, D, (2004), “Chronic pain patients are impaired on an emotional decision-making task” Elsevier, Volume 108, Issues 1–2, March 2004, Pages 129–136 http://www.sciencedirect.com/science/article/pii/S0304395903004974, retrieved 30 Nov 2016

[4] May, A (2008), “Chronic pain may change the structure of the brain,” Elsevier, Volume 137, Issue 1, 30 June 2008, Pages 7–15 http://www.sciencedirect.com/science/article/pii/S0304395908001280 retrieved 30 November 2016

[5] Rodriguez-Raecke, R, Niemeier, A, Ihle, K, Ruether W and May, A,  “Brain Gray Matter Decrease in Chronic Pain Is the Consequence and Not the Cause of Pain,: The Journal of Neuroscience, November 4, 2009 • 29(44):13746 –13750 http://www.jneurosci.org/content/jneuro/29/44/13746.full.pdf retrieved 29 November 2016

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