Touching Lives - December 2003
Retraining the brain
This condition — occupational dystonia — affects 5-10 per cent of professional musicians, and the resulting lack of control can have particularly catastrophic consequences for their career.
The musician’s brain is a good model for tackling all types of dystonia as their brains show a great deal of ‘over-specialisation’ as a consequence of a life-long training process, often beginning very early at an age when the brain is most susceptible to change.
Brain scans detail changes in musicians’ brain structure that you wouldn’t find in non-trained people. But it’s precisely this ‘overspecialisation’ of the brain that can make you perform well at a task that the team believe causes dystonia.
Dr Karin Rosenkranz, who will be working with Professor John Rothwell on the project, explains, “There are millions of connections in the brain and these are forever changing from moment to moment to optimise the way you do things.
“This ‘rewiring’ can become more permanent if you keep doing things over and over, like, for example, practicing the piano. The brain changes permanently so that you do the task as efficiently as possible. Our thought is that there may be a pay-off for this specialisation in that your brain may not be as flexible in adjusting to do other things.
“Only 5-10 per cent of musicians get dystonia so they may have some subtle difference in their brains which causes the brain to go a little ‘too far’ in its specialisation for one task which makes other systems susceptible to damage. We don’t understand why yet — but the brain rewires itself wrongly and permanently in these patients.”
Sensory discrimination training
This team will use the brain’s own ability to rewire itself to try to restore normal brain function. “With specific sensory discrimination training, we aim to re-educate the brain to link the right sensory information with the appropriate movement command,” says John Rothwell.
“We use a muscle vibration method which doesn’t hurt the patient. We give a sensory input in the form of vibration to one muscle in the hand. The patient then concentrates on that vibration, and to be sure that they do that we’ve built in subtle changes to vibration frequency and they have to report when they feel a change.
“The patient also has to actively relax their fingers — which is a difficult thing to do but you can train people to do it. ^The brain learns to induce an inhibition of activity, which is what we want to have^. We want to have a nice pattern of focused activation and the rest should be inhibited.”
The aim of the research is to provide a new treatment for occupational and musician’s dystonia. But musicians’ dystonia is a ‘model disease’ for which the principles and techniques of treatment could be applied to cases of brain injury, stroke, and so on. John concludes, “Treatment is not expensive and can be easily applied to the patient, so this research could potentially have a valuable impact across a broad range of patients.”