Tackling chronic pain is a challenge. Undoubtedly our understanding of pain, the role of the nervous system and other body systems, has advanced to permit a reconceptualisation of the experience and how we can approach it. The knowledge that there is a form of conditioning and learning that goes on, means that we can switch our thinking to address these mechanisms. Clearly a change in reasoning was and continues to be required to be more effective in dealing with persisting pain.
I often use the analogy of learning a language with patients. Most people at some stage have had to go through this process, with some more natural than others at developing the skill. Equally, the thought of learning a musical instrument provokes a similar comparison. What is needed? Understanding, time, motivation and practice are certainly necessary ingredients. We also require adequate rest and sleep to cement the changes in brain function that occurs as a result of its plasticity.
So what has been learned in chronic pain?
We can divide this into biological responses and behaviours that we purposely adopt. The brain learns to produce pain and becomes very good in some cases, creating the experience even when it is not required–recalling that pain is an output from the brain in response to a perceived threat based upon the danger (nociceptive) signals received from the body via the spinal cord; the caveat being that nociceptive signals and the act of nociception is neither needed nor necessary for the brain to create pain. Equally, nociception can be ticking on but without the brain producing the conscious experience of pain. This means that as soon as the brain is sure we are under threat, it will protect us with pain and concurrent responses. These include changes in movement, activity in the endocrine system (hormones) and the immune system that pervades our body as a second nervous system.
‘..pain cannot exist out of consciousness. In contrast, but often erroneously considered analogous, nociception can exist outside of consciousness. In fact, nociception can occur without the brain–high-threshold peripheral afferents and their spinal projections can be activated in the absence of brain activity. Indeed, tactile perception, pain and other bodily feelings can be thought of as outputs of the brain that are based on an informed interpretation of the information coming from one’s body.’ Taken from Moseley & Flor (2012)
The way we respond to pain is individual and learned from previous experiences. Clearly it is both useful and vital to learn that an oven is hot and a pin is sharp. Acute pain is an incredible device and one of the body’s responses to perceived danger. In persisting pain states, arguably the pain is not useful or promoting adaptive behaviours. Although, when the tissues are not as healthy as they may be, the peripheral nervous system is sensitive and movement is not normal, perhaps some level of pain is useful as a motivator to develop healthier tissues. Undoubtedly though, in many cases of chronic pain, the intensity and impact far outweighs any benefit. The incredible sensitivity, robust and lengthy responses to normal activities cause utter havoc and enormous distress such as in the case of complex regional pain syndrome.
Approaching the problem of chronic pain requires a 360 view on the individual. Understanding pain mechanisms, limitations, social impact and influential factors are all important in the planning of a treatment programme. In addition, as argued here, considering chronic pain as a learned response on different levels is a useful way of conceptualising the problem in terms of understanding how the situation has evolved and how it must be tackled.