Chronic pain is defined as pain persisting more than 3-6 months, this is the time it typically takes for injured tissue to heal.
However, both acute and chronic pain have a tenuous association with injury (tissue damage).
People can exhibit the signs and symptoms of chronic pain earlier than 3 months.
This is influenced by factors associated with developing chronic pain, including, but not limited to, a history of anxiety and/or depression, low education level, lower income and age.
In general, most treatment of chronic pain is unsuccessful.
This is related to poor expectations of patients (after many failures, who can blame them) (1), and treatments that are overly focused on the biomedical (tissue) factors of pain, that often don’t match up with patients’ goals (2).
There have been promising results achieved by combining physical therapies with cognitive based therapies to treat chronic pain. (3)
Why Do We Experience Pain?
Professor of neuroscience and world leading expert on pain, Lorimer Moseley, has previously described pain as:
…a conscious correlate of the implicit perception that tissue is in danger
For most, the perception of danger evokes feelings of fear, heightened sensory awareness and decreased cognition.
When we assess danger, there are two main forms:
- Actual danger – situations where our life or safety is at risk.
- Perceived danger – situations where we perceive our life or safety to be at risk, but it really isn’t.
Both actual and perceived danger activate the same neuro-networks in the brain and the same physiological responses in the body. (4)
Our perceptions of danger are shaped by numerous factors, including:
- Our age
- Our gender
- Our social
- Our cultural upbringing
- Our experiences
- Our current capabilities.
If pain is related to a perception of danger, and our perception is shaped by all those factors, it is fair to say that pain is shaped by those factors too.
Pain science has moved forward, and beyond simply being a perception of danger, pain is beginning to be defined as a “need to protect”. (5)
The perception of danger, or threat, is in part based on predictive processing. (6)
Predictive processing is what our brains do to make sense of the world we experience and take shortcuts to achieving a conclusion.
Because of predictive processing, and other neural processes, we tend to not see an objective reality, but rather a subjective reality.
This is especially true when it comes to pain.
When we are experiencing pain, our brain makes predictions about whether something is going to be “dangerous”, and produces pain preemptively, in order to protect us.
Pain is not the only time that our brains use predictive processing.
Take a look at the brick wall, and see if you can spot what is not quite right.
The Neurobiology of Pain
The big problem with pain, is that pain is perception that we perceive as a sensation.
It tricks us into thinking that it is coming from our body, when in actual fact, pain is always produced by the brain and localised to the body. (7)
It is complex, and emergent, not linear.
So just because you feel a certain way after doing something, or not doing something, does not mean that your actions, or lack thereof, caused that feeling.
In the diagram below, I’ve simplified the neurobiology of pain with injury (remember, pain can occur without injury, and injury without pain as well).
Injury here is used loosely to describe the inciting physical event that damages the body tissue – it could be physical trauma, it could be an immune response from an infection or an auto-immune condition, like rheumatoid arthritis.
This leads to nociception – “danger” signals that convey a change to the status of the cellular environment.
That could mean a change to the mechanical load, a change to the chemical environment or a change to the temperature (the three primary types of nociceptors).
Inflammation is an immune response, and we know the brain and nervous system has a large role to play in the immune response (these days, doctors are calling it the neuro-endocrine-immune system). (8, 9)
Inflammation can lead to increased nociception, and if nociception increases, then this is a mechanism for increased inflammation. (10)
This can lead to peripheral sensitisation – where the sensory nerves in the affected body region become more sensitive due to physiological changes that take place.
All of this takes place locally, but we do not experience pain as a result of this just yet.
The Brain Modulates Everything
Modulation is a process whereby signals (nociception) reaching either the brain or spinal cord are amplified or inhibited. (11, 12)
Modulation can be affected by our thoughts – conscious or unconscious.
Here is where it gets interesting: we often think that our thoughts are ours, but there is compelling evidence that this may not be the case, and that our culture and environment shapes our thoughts, feelings and actions more than many of us would care to admit. (13, 14)
Using this line of thought – when it comes to pain, our ideas and understanding, especially at an unconscious level are already implanted by the culture we live in.
Currently our culture around pain is:
- Pain is bad.
- Pain is caused by damage, or degeneration (the dreaded “wear and tear”) or misalignment.
- “I’m just getting old.”
- Pain needs to be “fixed” – and can be done so by the right practitioner.
- We need to find the cause of pain, and this can be done by physical assessment and diagnostic tests (MRIs, X-rays etc).
- The weather causes pain to flare up.
If you live in Australia, or any other Western nation with a similar culture, all of these memes, plus many others, have been implanted into your thoughts.
You don’t even question them most of the time, because you don’t know you have them, until you experience pain.
Our thoughts shape our emotions, our emotions shape our actions and our actions reinforce both.
This is especially evident when we experience pain.
Changing The Unchangeable?
We discussed earlier that pain is a protective response, which is based on the perception of threat.
There is a greater evidence of danger to ourselves, than there is of safety for ourselves. (15)
Going back to the premise of this post: chronic pain is rooted in fear.
Fear changes our perceptions.
Fear makes us think or feel that we are in danger moreso than we actually are.
Fear makes us want to find safety.
But if fear is influenced by a host of factors, many that we don’t know, and most that are unconscious, can we change it, and as a result, change pain?
Cognitive Based Therapy
When we can identify our fears around pain, then we take away some, if not all of its power.
Yes, pain will still hurt, that’s the nature of pain, but our suffering is different.
We stop catostrophising.
We stop worrying.
We start focusing on what we can do.
We start focusing on who we are.
The challenge of identifying and treating unconscious fears is obvious.
Fortunately, over the years, psychologists have developed many ways to explore our unconscious.
One of which, is cognitive behavioural therapy.
Cognitive based therapy is based on the premise that each thought is related to a certain emotion and behaviour, and vice versa.
By exploring each aspect around our beliefs and understanding of pain, we can change what we think, feel and do, to decrease our pain and suffering and eventually, change our unconscious thoughts.
Cognitive behavioural therapy is not only effective for treating pain, but also something that can be performed by suitably trained manual and physical therapists*.
A Way Into The Neuromatrix
What you can see in this diagram, is that there are multiple inputs (on the left) to the “body-self neuromatrix” (the representation of ourselves, within our brain) from both the body and brain, which influence what our body does, how it feels and how it functions (outputs, on the right)
- Cognitive related brain areas
- Sensory signalling systems
- Emotion related brain areas.
But, that’s not all, each of these inputs can affect each other, as can each output.
Everything affects everything when it comes to pain.
What any good clinician is trying to do when treating someone in pain, is provide enough context for the outputs of the neuromatrix to change.
We do this by influencing the inputs in a way that promotes increased descending inhibition (as discussed earlier).
In addition to CBT, we can use other interventions like touch (manual therapy from intelligent, responsive hands) and movement.
Basically, we are trying to tell your brain that it’s okay, things are safe and you don’t have to be on edge.
When your brain is no longer in “fear mode”, it can resume normal modulation duties and you start to feel better.
Most chronic pain occurs in post surgical patients. (16)
There is an obvious physical trauma that takes place.
Many others develop chronic pain conditions after intense and/or prolonged psychological and/or emotional distress.
Something occurs to shift the brain into “fear mode”, in which it wants to do nothing more than protect itself (and you), which it does by producing pain.
We know that pain is complex and multi-factorial, but too often we think we are the exception.
It can feel like we just need to “release” that tight muscle or “crack” that stiff joint.
It can feel like there is “wear and tear” or “damage”.
But at least 40% of people with widespread arthritis don’t experience pain.
Amputees with no limbs do experience pain, in the absent limb!
You have to be fully engaged in the process, and willing to confront a lot of home truths about what you think, feel and believe if you want to treat your chronic pain successfully.
Even when you do that, sometimes you’ll still be in pain.
But, if you don’t, you’ll definitely still be in pain.
This blog post was written by Dr Nick Efthimiou (Osteopath), founder of Integrative Osteopathy.
This blog post is meant as an educational tool only. It is not a replacement for medical advice from a qualified and registered health professional.
*If your condition was too complex for the therapist alone, we would refer you to a psychologist. In Australia, there is a mental health plan, under which your GP can refer you for up to 10 consultations with a psychologist, partly subsidised by medicare.
(5) What is pain?
(13) Free Will
(14) Myth of free will