Pain
With some new team members starting at Platinum Physiotherapy this week I thought it fitting to revise some of the masterful work from David Butler and Lorimer Mosely from Noigroup. As previously mentioned these guys have truly opened my mind on pain understanding and management. Below is a summary teams discussions this week, which was based around their remarkable book "Explain experiences and observations in our clinic.
What is pain?
I dare say that if you are an experienced clinician you answer to this seemingly simple question has changed many times over the years, and if your a new grad you are nervous to answer because you think it is a trick question!
No one really wants pain. One you have this unpleasant experience you want to rid yourself of it. However the very nature of pain is essential for life in that it alerts us to danger. Pain is not a reflection of tissue damage!
Occasionally the pain system appears to act inappropriately, yet it remains a response to what brain judges to be a threatening situation. So despite common problems which exist in our joints, discs, muscles, ligaments, immune system or anywhere else, it won't hurt if your brain thinks your not in danger. Pain is not a reflection of tissue damage!
Pain is so unpleasant that it makes you do something about the situation and the brain decides where and when it's most appropriate to manifest itself. The trick with managing pain is figuring out why the brain has come to the conclusion that are in danger and need protecting.
This is the framework for the modern understanding of pain.
What's happening in the tissues is just one part of the pain story. In Lower back pain, research shows that the amount of nerve and disc damage rarely relates the the amount of pain experience.
So pain relies on context. Sensory information is evaluated by the nervous system and a response is concluded. A complex evaluation of memory, reasoning and emotional process, which in turn is influenced our past experiences, perceptions, understanding of pain and nervous system integrity. So to effectively deal with pain we must understand the context and how we can influence the ignition cues. Pain is not a reflection of tissue damage!
Phantom pain tells us about the representation of the body within the brain.
Throughout our nervous system there are millions of sensors. They are like little spies sitting in neurones and reporting back on stimuli. Some respond to mechanical forces, some temperature changes and others chemical changes. Along with the specialsed sensors in our eyes, ears and nose, they are our first protection against potential harm.
The life of a sensor is short and replenished - important point for pain sufferers!
Some clarification of terms in the modern understanding of pain. We do not have pain receptors, pain nerves, pain pathways or pain centres. What we do have are some neurones that respond to all stimuli if sufficient to be dangerous to the tissue. An alert is send to the spinal cord, brain and a subsequent response made. The nerve activity is called nociception, which literally means danger reception, and is not necessary or sufficient for pain. So we all have nociception happening all the time, but rarely does it end in pain.
Various sensors are embedded in the membrane of a neurone. A sensor must be opened for ions to flow through it and the neurone becomes electrically excited. Once this hits a crucial level (action potential) a nerve can carry a danger message to the spinal cord. Not a pain message. At the end of the neurone in the spinal cord chemicals are in turn poured into the synapse between the neighboring neurones heading to the brain with sensors that respond to only some of the chemicals. (This is now at a spinal cord level at the dorsal root ganglion - aka "mini brain".) Now, it's when a danger message gets past the synapse and into the brain that this whole story gets interesting. The brain uses this as well as a lot of other information to construct a sensible story and subsequent perception of what is happening. One response may be pain, but the brain may also decide that sweating or moving is more appropriate. Pain is not a reflection of tissue damage!
There is not just one pain centre in the brain. There are many areas which may be involved and act as little ignition nodes, which become very sensitive for chronic pain sufferers. Conversely, we have many systems in place to help us. Messages entering the brain must come out in some shape or form (what goes in must come out in a sense). It is here where our sympathetic NS, motor system, endocrine, immune and parasympathetic systems come into play with their associated responses.
Understanding the stages of tissue healing does play a role in this story for the best outcome for our patients. No matter what tissue you have injured, a similar healing process occurs. An immune response of inflammation, scar tissue formation and remodeling, all proportional to blood supply and tissue demand, and should be proportional to pain. The point here is that tissues heal but pain is variable. Thus, Pain is not a reflection of tissue damage!
Some quick facts:
Inflammation is a protective mechanism
Muscles have a great blood supply so are great healers
Discs are not fragile, NEVER slip and are actually made of the same strong tissue as our ears!
Pain often involves something going on in the tissues such as inflammation, slow healing or unfit or unused tissues. But the level of pain is not a reflection of tissue damage!
All pain is real, and all pain can be modulated.
In chronic pain sufferers we know that pain persists even though the initial injury has had time to heal. So the command centre or brain concludes that a threat remains and you need all the protection you can get so sends a danger signal = PAIN. So from here we can conclude that for some reason there is a problem with the alert system. An altered central nervous system alarm.
Now some essential neuroscience: the nervous system is very adaptable and responsive. I the short term this means that it will increase its sensitivity to incoming alerts - hyperalgesia, and that things that didn't hurt before now hurt - allodynia. It's essentially a protective mechanism that involves redistribution of danger messengers and sensors, and in persistent pain the system doesn't shift back to normal. So in effect this malfunction occurring in the spinal cord in turn tricks the brain into thinking there is an issue with the tissues! More danger than what there actually is. INCREASED SENSITIVITY = pain perception. You can see that pain is not a reflection of tissue damage!
But wait there is more......
Thoughts and beliefs are nerve impulses too. David and Lorimer have appropriately labeled them "Thought Viruses" throughout their literature. One of their many powerful neuroscience descriptors that lured me into their thought process. They can act as mirror neurons in our brains and fire when you think of movement. (I'll talk about this again later with both powerful metaphors and motor imagery discussions - very exciting and thought provoking stuff!)
Some common features of a sensitized alarm system: persisting, worsening, spreading and less predictable pain, lots of movements hurt, pain links to your mood, thoughts or feelings.
More science revision now..... So our response systems, which act in many other capacities, but play an important role in pain experience consist of our sympathetic and parasympathetic nervous systems, endocrine, immune and movement systems.
The sympathetic nervous system: a powerful, rapidly responding system that liberates adrenaline in response to sensory input to help you cope with stressful situations, along with regulation of breathing, digestive system, blood pressure, pupil size and more.
The parasympathetic nervous system: more concerned with slowing or conservation of energy. A calming, rather than exited state.
The endocrine system: works with the sympathetic nervous system, but for a more prolonged period. The key hormone (released by the hypothalamus, pituitary gland and adrenal gland) is cortisol. It is essentially another protector that slows down body processes not needed for immediate protection, and enhances those which are. We face problems such as depression. Oxytocin on the other hand is also regulated by this system - it's basically a very powerful, free happy hormone that you can release you self - do something or think about something that makes you happy!
The immune system: another powerful system looking after us and whose key molecules called cytokines also interact with cortisol and adrenaline (and ACTH).
The movement system: the brain primes muscles to get ready to escape!
Ok that's enough of the neuroscience facts for now, what can we do to help our patients in pain based on this emerging paradigm?
Firstly we must consider that our patients (particularly those with chronic pain) have probably already been indoctrinated by a stream of harmful metaphors by a range of other health care professionals and less orthodox "healers". (It's almost comical taking about some of these "painful metaphors", where they come from and the context they are presented to our patients with so I'll save this for a later, light hearted blog!)
After I have heard a patients story I give them the following spiel: "I would like to help you figure out what is happening in your body to cause you pain, and ultimately take control of your pain. For me to do this I will need to ask you some specific questions about the history and quality of your pain, as well as some questions that initially may seem like they are unrelated to your pain but will become relevant to your story later. We will spend some time setting realistic goals that you are happy with and please make sure that what we are doing makes sense to you and that I answer all your questions and concerns along the way. You may not experience less pain each time you visit the clinic but It's essential that we learn something from every consultation that can help you along your path.
We need to work as a team to identify all the possible threats that might be affecting the patients pain. Inform the patient and ensure they have a clear understanding about their body and the pain they are experiencing.
We then need to work together to peal back the threats through education, understanding of pain, graded activity/ exposure and accessing the virtual body with imagined movements, altered gravitational influences, balance challenges, varied visual inputs, environments, different emotional states, adding distractions, functional activities and sliders
