Banjo brain surgery

by Vaughan

Surely this must be the greatest headline for a BBC News story ever: Banjo Used in Brain Surgery.

Although the banjo wasn't in the hands of the surgeons it was still an essential part of the operation. It was played by legendary Blue Grass musician Eddie Adcock who was having surgery install a deep brain stimulation device to treat an essential tremor that had been affecting his playing.

The BBC News story has a video of the neurosurgery and the banjo playing, and it is pure genius. Probably the best thing you'll see all year.

Essential tremor is a condition where there is a continuing deterioration in areas of the brain that control movement. This causes a tremor that usually appears when the person tries to act or move, although can lead to a 'resting tremor' that's also present at other times.

Essential tremor is not Parkinson's disease, which, while also associated with tremor, is a much more serious and disabling condition in many ways. There does seem to be a link though, as people with essential tremor are more likely to develop Parkinson's, although this still only happens in the minority of cases.

However, deep brain stimulation can be used to treat the movement difficulties of both Parkinson's and essential tremor. It involves sinking an electrode into the thalamus, a deep brain area that is part of the motor loop - a circuit that helps co-ordinate movement.

In fact, there are two parts to the motor loop - the direct and indirect pathway - an each play a complementary part in directing movement, and each of which needs to be balanced with itself and with each other. When damage to these circuits affects this balance, the result is that it causes too much activity one way, which causes a compensatory response the other, and so on.

Imagine two people, completely unaware of each other, trying to balance an uneven seesaw. The oscillations in the control system cause oscillations in movement, and this is what you can see in tremor.

DBS works by sending electrical impulses at a certain frequency into the thalamus to dampen down the oscillations. However, the oscillatory push-push cycle is not the same for everyone, and the best spot in the motor loop itself will also differ.

To get the best result the surgeons tweak the electrical pulse settings and try different areas.

To make sure it's having the desired effect, the patient is awake and they ask them to move. When they see that they've hit the sweet spot and the pulses are in time, they know their job is done.

http://www.mindhacks.com/blog/2008/10/banjo_brain_surgery.html