Thursday, November 1, 2007

Pain for Dummies – Part VII

Or: what’s this new approach all about?

As described in the previous posting the old paradigm – the body based approach - is still alive and used widely.
The new one is radically different – so much in fact that it seems strange and too simple.
How to explain it so that everyone can understand and benefit from it?

A good starting place are these two great books: Phantoms in the Brain and The Body Has A Mind Of Its Own. They are able to give a much more in-depth view of what it means to have a brain. ;-)

In short: imagine yourself having to drive from say Paris to Berlin. In order to prepare yourself for the journey and to be able to estimate the resources you need (time, food, gas,…) you use a map. The map isn’t the territory – it would have to be on the scale of 1:1 to do that – but it is a representation of the actual landscape you are going to be traveling through.

You Decide

With the help of this map you can easily measure distances which – combined with speed – give you a rough approximation of how long the journey is going to take. You can check for elevations, roads, highways, restaurants and so on. You are able to plan the journey – including rest stops and a whole lot more solely based on the representation you have lying before you.

Maps are so great in fact that our brains have discovered them millions of years ago. Even better – we not only have one map but hundreds of them – each for one specific function.
Maps of the body are so old that they are hardwired into the genetic structure of our brains – meaning that even when you are born with a missing limb the map for it is still there in your brain.

The modular structure of our brains is laid down very early during development – congenitally blind people (blind from birth) still have a visual cortex and so on.

Maps are so useful because they enable us to react lightning fast; if your brain had to check if there really are two legs when you slip you’d have fallen to the ground before you could react. With a map in place everything is sped up and you are able to recover balance. Most of the time anyway. ;-)

The old paradigm focused on the terrain itself – in CRPS for example treatments were aimed at restoring circulation to the injured limb. What neuroscience has found is that instead the arm being the cause – it’s actually the hand representation (the hand map) that is the cause of the changes we can see.

Other – so called higher centers of the brain – then act on that distorted information; no wonder that the output they produce isn’t the right one – they simply don’t "know" better. The brain is acting on distorted information.

Treatment has to focus on the cause: re-modeling the hand representation as fast as possible.
Fortunately these maps are plastic – that means they have the ability to change. That’s how we are able to learn and acquire new skills – if we learn to ride a bike for example those new motor patterns become hardwired into the structure of our brains. In the case of chronic pain that whole process of learning goes haywire – there is such a thing as too much of a good thing.

Re-training or re-modeling can take different forms – depending on where your individual starting point is: if really all movement with the affected limb is painful then start with motor imagery, i.e. imagining moving the limb. Motor imagery is very effective as a stand alone treatment since it activates the same neural circuits in your brain that you use to do the actual movement. All that’s missing is the motor command that tells you muscles to contract.

After this first step you can start actually doing the movement with a mirror box – the affected side behind the mirror so that your brain is fooled into thinking that the limb it can see is doing what it wants.

You create a congruence of motor intent, motor output and feedback that way.
Gradually the map is remodeled and function returns.

As Harris points out it’s enough for pain to occur when the brain is unable to make sense of divergent information – so pain should subside very quickly when you do the few first sessions – only to return a short while afterwards.
Don’t despair – it just shows that your brain is still able to turn of the pain and willing to learn.

At least this should give you the hope and motivation one so desperately needs when so else has failed.
And the best thing: it’s easy to do.

One can only hope that these new findings spread as fast as possible since even some of the most serious illnesses out there – think anorexia with a 20% death rate – most probably have their origin in these body map disorders.
Reestablishing those maps can alleviate symptoms very quickly and help save thousands of people from suffering.
Spread the word!

No comments: