Complex Regional Pain Syndrome (CRPS) often presents with a number of signs and symptoms. The main complaints are usually pain, colour change (minute to minute sometimes), temperature change, swelling, sweating changes, skin/nail/hair changes (trophic) and an altered perception of the affected part. It is this last sense that I am going to focus upon in this blog.
I hear many different descriptions of the symptoms of CRPS and actually encourage the use of a wide range of words. This is so that I can develop a really good picture and insight into the individual’s experience which is exactly that, individual. One aspect that I am particularly interested in is the perception of the affected area. In the vast majority, if not all, cases there is an altered sense of the region. For example, in the case of the hand it can feel bigger (sausage fingers often a good description of the feel), swollen, distorted, out of place, detached, like it belongs to someone else, like it is not there unless looked at (visual input to confirm presence) or denial that it is there at all (denial – similar to those who suffer strokes).
This variety of descriptions paint the picture of a ‘stranger’ aspect of the condition, often claimed to be ‘weird feelings’ as they are so abstract and like nothing before. Clearly this can be worrying and sometimes I hear that when the descriptions are given to others there maybe disbelief. Any aspect of a problem that creates fear or anxiety can affect pain and must be addressed.
So what is going on? When we have an on-going painful problem and we are not moving normally, changes occur within the central nervous system to give us this different experience. In the brain we have maps, virtual maps, that the brain uses to work out where sensory information is coming from and control movement. These maps are well defined under normal circumstances with a genetic blueprint that is moulded by experiences. This precise definition relies on a constant stream of information coming in from the tissues. In the case that this flow is altered or stopped, the map changes. We know this from fMRI studies that demonstrate reorganisation of the brain in certain areas. Certain representations of body parts are found to be in different locations in pain states. In fact, many brain changes have been found in chronic pain, these changes underpinning our different experiences of the body. The good news is that with effective treatment of the pain, these changes are reversed. Effective treatment will be the subject of another blog, but this includes such therapies as graded motor imagery and others that seek to ‘redefine the maps’.
In summary, chronic pain states, including CRPS and back pain, we know that the cortical (brain) maps change and that this is the reason why the affected area can feel ‘weird’, out of place and just not right. The map is ‘smudged’. In a sense this is useful as it draws our attention to something that needs dealing with imminently. The focus of treatment for this is upon ‘redefining’ the maps, the same for a range of conditions. In fact, my view is that this is what modern rehabilitation is really about in essence, via normalisation of sensation, motor control and the congruence of these factors, alongside the traditional strength gains and tissue changes. Our understanding of smudging and cortical reorganisation has triggered a change in thinking for rehabilitation, targeting the brain, training the brain and offering science based solutions for chronic pain.