NOI Notes

Reaching everyone through a blog isn't easy. So for about 6 months now I've been writing a monthly newsletter along with my noigroup team which discusses lots of different topics - making them relevant to both the patient and clinician.

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What is a neuromatrix?

Readers frequently ask about the definition of neuromatrix in relation to the brain and pain. Wikipedia and Google are not that helpful (yet), though there are some good links on Google to Ronald Melzack’s pioneering work. (Melzack, 1999, 2001).

Cognitive Psychology is merging to some degree with neurobiology. While the term neuromatrix has emerged with the increasing knowledge of brain neuroscience, some of the older cognitive psychology writings provide good definitions and understanding of what we now call the neuromatrix.

I like “a map of event space in the system’s coding space” (Dudai, 1989). So the coding space is all the possible combinations of connections in the brain. Pain or jealousy could be an event which would take up part of this space. The event space has been referred to by Melzack as the neurosignature. So a pain neurosignature exists within the neuromatrix. Moseley and I (Butler & Moseley, 2003), trying to be a bit trendy, refer to the neurosignature as a neurotag.

Of course it is all far more complex than this. A pain neurotag exists in a snapshot of time. It will change over time and context. Everyone’s pain neurotags are different and even our own pain neurotags will be structurally different within the brain over time.

The term “representation” is also used in relation to neurosignature.

Hoping this makes sense!!

Butler, D. S., & Moseley, L. S. (2003). Explain pain. Adelaide: NOI Publications. Dudai, Y. (1989). The neurobiology of memory. Concepts, findings, trends. Oxford: Oxford University Press. Melzack, R. (1999). From the gate to the neuromatrix. Pain, Suppl 6, S121-S126. Melzack, R. (2001). Pain and the neuromatrix in the brain. Journal of Dental Education, 65, 1378-1382.

Recognise training – instability of findings

Recognise training refers to the restoration of laterality via the "Recognise" computer programme.

A clinician reader has noted in a patient with CRPS of early onset, that results with the Recognise programme are variable, i.e. the patient has good results one day, but poor the next. In short, there appears to be some instability in the laterality recognition process. This does not appear to occur in more long standing CRPS cases, where the laterality deficit is more entrenched.

I don’t know what causes this, but it would appear that the premotor to motor pathways that block laterality expression are still unstable, or said another way, the brain is still not quite sure that altering motor output is the best way to proceed and there may still be some competition for the best biological system (motor, sympathetic, endocrine etc) to defend the body. Early intervention is certainly supported by this finding.

We really enjoy hearing about what clinicians find. There are a number of groups carrying out research on laterality problems and their restoration and the clinical findings are very helpful for research design and understanding research findings.

The power of context

“In an individual, the exact same movement can be represented by different networks of neurones and different synaptic activity”

How does the above statement resonate? For example, if you were to turn your neck with eyes closed or open, or in differing moods, there would be different populations of neurones engaged, yet the movement would look exactly the same.

The footballer about to kick an end of game penalty which could win the game has a motor programme ready to play. If that motor programme had been constructed and practiced in various contexts then it should be a richer and better programme and the outcome should be better. For example, if the penalty kick motor programme had been practiced in a stress state, therefore with lots of glutamate in the brain and areas such as the amygdala now linked into the motor programme, the motor programme should not be that disturbed when the kick is in a stressfull context.

Context of movement can altered in many ways –gravity, vision, various distractions, various emotions, altered threats, place, balance, meaning, even going back in time – perhaps the benefit from dance that many patient’s with Parkinson’s disease get, is that the dance and/or the music accesses old movement neurosignatures.

I don’t think the rehabilitation therapies are aware enough of the power of context.

Keep your comments coming in to b1@noigroup.info

How to make a Mirror Box

We sometimes get asked how to make a mirror box. There are a few on the market including the NOI version, but you can make your own. A beer carton with a cheap mirror on the side could be used, but it is worth going that bit extra as the quality probably affects the outcome and it is likely that it will have to be used for at least a few weeks. The mirror boxes used in research are often large and wooden, but all you need is a box to hide the affected limb and a mirror.

The mirror first – get a good quality perspex one, not glass for safety reasons. It should be at least 30x25 cm so you can get the patients face in the mirror as well as their hands. It is important that the mirror must not buckle otherwise a distorted image will be provided – remember the convex and concave effects of mirror at the local fair. If the mirror can be unattached from the box, or the box is collapsible, even better – this means that you can then use it for the feet.

Make the box a fairly neutral colour – you don’t want to draw attention to it. A material such as corflute makes it easy to clean (patients often sweat in mirror boxes). Make it open at both ends to give the perception that the limb is just hidden and not in some container. Finally, the mirror box should be easily collapsible. It is likely that it will be taken to work, home and on holidays.

Having gone through all that, you may wish to just buy one.

Laterality intact, but a touch of asynchiria

Our friend Hardy the fireman, fell through a plate glass window and managed slice up his RIGHT forearm including a few tendons and the median nerve. His arm has been surgically repaired and is looking good at the 4 week stage. I was interested to see if there were any laterality deficits.

We ran the Recognise computer laterality programme. I ran it 3 times with 20 vanilla hand images by 5 seconds (therefore randomly picked left and right images came up sequentially on the screen to be identified as left or right).

Hardy did well. By the third test he was equal left and right in speed and accuracy of recognition. In the first two trials it took him longer to recognise LEFT hand images (over 1 second difference) and he was inaccurate recognizing LEFT sided images (60% LEFT compared with 90% RIGHT).

These results are worth a thought. In a CRPS state the opposite would be expected, i.e. difficulty and slowness recognizing an image of the painful/injured side (G. L. Moseley, 2004; Schwoebel et al., 2002) so I initially expected Hardy would have had similar responses if there was any left/right variation. Interestingly, in studies of acute experimental pain (G. L. Moseley et al., 2005), and expectation of pain responses (Hudson et al., 2006), this also occurs, suggesting a focus on the injured/painful side as opposed to the neglect often seen in CRPS.

Hardy was pretty cool with the whole arm problem, and although he was off work, he was not that concerned by it and could see he was making progress, or said another way, I thought that he wasn’t letting it get to him.

While it would be nice to know what these findings meant in terms of outcomes via research, my initial thoughts were that at this stage that Hardy didn’t need any graded motor imagery and he was progressing quite “normally”.

We tried a mirror box and noted that he experienced pain in the injured hand which was not moved (i.e. the one hidden in the mirror box). This phenomenon is called dysynchiria and its probably the best example of pain really being in the brain (Acerra & Moseley, 2005). I will discuss dysynchiria in later blogs.

Acerra, N. E., & Moseley, G. L. 2005. Dysynchiria: Watching the mirror image of the unaffected limb elicits pain on the affected side. Neurology, 65, 751-753.

Hudson, M. L. et al 2006. Expectation of pain replicates the effect of pain in a hand laterality recognition task: Bias in information processing towards the painful side. European Journal of Pain, 10, 219-224.

Moseley, G. et al 2005. Experimental hand pain delays recognition of the contralateral hand - evidence that acute and chronic pain have opposite effects on information processing. Cogn Brain Res, 25, 188-194.

Moseley, G. L. 2004. Why do people with complex regional pain syndrome take longer to recognize their affected hand? Neurology, 62, 2182-2186.

Schwoebel, J. et al 2002. Pain and the body schema: Effects of pain severity on mental representations of movement. Neurology, 59, 775-777.

CRPS: Patient Development

Back to the patient: a 30 year old female who has a four year history of Complex Regional Pain Syndrome (CRPS), post right wrist fracture. Her pain has also spread into her right lower limb.

This patient is now being managed, as I write, by a physiotherapist. I will collect more information about the patient as I go along.

The clinician writes….."I saw the patient today to begin the graded imagery program. She was obviously very excited and a very willing participant. Based on the protocol laid out by Moseley, I have her doing either the computer program or the flash cards 3xs per day for at least 10 minutes per session. She will do that for two weeks and then return with the data she collected from the computer. While in the office I had her perform 4 trials of the computer based program and no matter what program she used for the upper extremity she consistently scored 70-75%. I was able to score 90% but am not sure what that means. Is there any normative data about people with CRPS and how well they do using the computer program or the flash cards vs. those who do not? Should there be a goal we achieve with the program i.e. 85% before we consider it a success and move onto the visualization portion of the protocol?”

These are good questions which expose (a) the amount of evidence available and (b) the need for management which is individualised for patients.

There is no normative data on laterality, although I am aware that this is now being done and we will post any research outcomes on this blog. For this patient, it would help to have information on differences between left and right laterality accuracy and speed in both hand and feet. If there are differences, then it would be worth continuing the programme, thus “exercising” those laterality association neurones influencing the patient’s motor responses (next blog will be on the neuroscience of laterality deficits). The consistent scores of 75% may well be quite normal for that person, and the patient may have little or no laterality deficits and can progress towards motor imagery strategies. They could well continue the laterality exercises while doing motor imagery. But as mentioned elsewhere, before you can imagine a limb movement, the brain must first be able to pick whether it is a left or right limb.

If the patient continues to use laterality training, here are some thoughts:

1)laterality problems may be exposed by grading use of the CD. For example, make images come up faster, use more images, use the contextual and abstract images. Maybe even use the programme in a position that hurts a little bit.

2)Use of the flash cards can be made more difficult as well. There are progressively more difficult games that can be played

3)I suggest that at least 2 hours a day (broken into sessions) of laterality could be performed. It can be done through the day i.e. looking at people and saying “that’s left, that’s right”

4)Get a magazine such as “who” with lots of pictures of people and go through it and circle the left or right limbs, which ever is painful.

5)Make up laterality games.

Complex Regional Pain Syndrome and GMI

At NOI, we often get requests for advice using the graded motor imagery programme (GMI).

A typical question may be: Can you offer any assistance and advice using the GMI programme for a 30 year old female who has a four year history of Complex Regional Pain Syndrome (CRPS), post right wrist fracture. Her pain has also spread into her right lower limb.

Here is a suggested start:

1. Review in your own mind what CRPS is. It is perhaps best considered as a multi-mechanismed disorder with likely nociception from tissues, some adrenaline sensitive nerves, an upregulated central nervous system with a perturbed sympathetic nervous (SNS) system. The SNS is just one of a number of body systems used as a defense. It is possible that there will be altered endocrine, pain and immune systems as well. One of the processes in the upregulated CNS is likely to be distortion of the arm’s representation in the brain.

2. Although there is no direct evidence, we can extrapolate from existing research and use anecdotes to suggest that GMI works better if a person understands the biology of what has happened to them, in particular, the notion that the brain is the prime therapeutic target. Use of the explanatory book “Explain Pain” is suggested.

3. Perturbed sympathetic nervous systems are more likely to have occurred due to real or perceived threats to the person, rather than input from the damaged wrist, though the wrist inputs will contribute. These threats could be wide ranging (why hasn’t therapy worked, what is wrong with me, will my family life hold up, etc etc) and need identification.

4. The most recent of example of literature demonstrating efficacy of GMI is Moseley, GL (2006) "Graded motor imagery for pathologic pain." Neurology 67: 1-6. This paper has a substantial reference list.

5. Clinical trials are guides only. For management, the clinical trial material must be placed with all the clinical evidence associated with a particular individual. Research can homogenize patients. Chronic pain states such as CRPS are characterized by variability in presentation.

6. Useful information emerging from Moseley’s research suggests that GMI really should be graded! That is a person should have a good sense of laterality first, before moving onto various motor imagery tasks, before moving onto mirror work. This makes a lot of sense. If the reader was to look at another person’s hand and imagine that their own hand is in that position, the brain would first have to compute that it was a left or right hand, otherwise there will be a bit of intracranial confusion and synaptic stress.

More practicalities, especially related to the patient and use of laterality in the next posting. Please send questions and queries to b1@noigroup.info

Introduction

Motor imagery, i.e. visualizing yourself in a particular posture or movement has been around for ages. It is known to improve athletic performance. It has had a rebirth with the advent of brain imaging tools such as functional MRI which created an awareness of how changeable and plastic the brain is. In addition, the discovery of mirror neurones which are active when you watch a person move provides a secure base for graded motor imagery studies and therapy.

The graded motor imagery programme (GMI) takes this concept further. It consists of a programme of laterality reconstruction, motor imagery and mirror work and it appears to work best if carried out in that order.

So far there is evidence of efficacy for its use in Complex Region Pain Syndrome and phantom limb pain Moseley, GL (2006) Neurology 67: 1-6. However, as the blog progresses we will share anecdotal clinical knowledge on the use of the programme for other pain states and make readers aware of emerging associated scientific literature.

Laterality reconstruction is the restoration of the brain's concept of left and right. If you look at another person’s hand and then try and imagine your own hand in that position, can you see that the brain first has to identify if it is a left or right hand. If it can’t then there will be synaptic stress and perhaps more pain. Perhaps removal of laterality identification is a defense to close down motor output. We will discuss this in later blog entries. At NOI, we use two tools to asses and treat laterality deficits – flash cards and the Recognise programme.

Motor imagery is conscious access to brain parts involved in intention, preparation and carrying out movement. Brain mapping studies have revealed great overlap of brain regions involved in actual or imagined movements. (e.g. Grezes J., Decety J. 2001 Human Brain Mapping 12:1-19). Motor imagery could be watching an activity, imagining your own body in a static posture or imagining it moving. We will discuss this, including clinical practicalities in further postings.

Mirror therapy is where the brain is tricked into thinking that the limb is actually better than

the brain thinks it is. Note in the image, that if the affected limb is “hidden” inside a box with a mirror on one side, use of the good limb will inform the brain, via the reverse image, that the painful and disabled limb can be moved.

While literature such as Moseley’s recent randomized clinical trial (cited above) provides welcome support for the use of neuromatrix training, the clinical world is always different to the research world. As these blogs progress, we will share clinical experiences, discuss the neuroscience basis of GMI and always link to emerging research.

To conclude for now, to achieve synaptic strength and linkages, activity (including thought) has to be repeated, graded, conquered and context enriched.