Tuesday, December 23, 2008

Putting pain into perspective - Times Online

Throw out those painkillers: the secret to salving physical aches may lie in using a pair of binoculars the wrong way round, claims research performed at Oxford University.

The study, published in Current Biology, reveals how powerfully pain and even swelling can be a product of our mental attitude.

Researchers asked ten people who suffered chronic pain in one arm to move the limb around while looking at it through a pair of binoculars that were either the right or wrong way round.

When they saw their arm magnified to double its size, the patients reported that their levels of pain increased, but when they exercised the arm while watching a minimised image of it through inverted binoculars, their pain levels were cut significantly.

But it was not only their perceived pain levels that changed, says the lead researcher, G. Lorimer Moseley. Their levels of physical swelling in the affected areas were also reduced through using the backwards-binocular trick.

Moseley says he is not sure how this phenomenon works in terms of specific neurons firing, but he believes that the brain changes its protective responses according to its perception of danger levels. “If it looks bigger, it looks sorer, therefore the brain acts to protect it,” he explains.

Moseley hopes that the optical-trick discovery will lead to a practical method for lowering pain and trauma levels in hospitals.

In effect, the binocular trick offers a much simpler and cheaper version of a pain-lowering brain-scan method pioneered by American researchers. Scientists at Omneuron, a California-based company, are using a functional magnetic resonance imaging (fMRI) machine to treat chronic pain. Patients are placed in the scanner and asked to watch a computer-generated flame projected on the screen of virtual-reality goggles. The flame's intensity reflects the neural activity of regions of the brain involved in the perception of pain.

By concentrating on a variety of mental techniques - such as imagining that a painful area is being flooded with soothing chemicals or marching soldiers - most people can make the flame wane. As the image of the flame wanes, the patient starts to feel less pain.

A 2005 study of eight patients with recalcitrant pain felt their discomfort reduced by as much as 64 per cent by using Omneuron's technology. Christopher deCharms, the chief executive of Omneuron, says, “We believe that people will use real-time fMRI feedback to hone cognitive strategies that will increase activation of brain regions.”

He adds that, with practice and repetition, this could lead to “long-term changes in the brain”.

Alternatively, of course, pain patients could simply try playing around with an old pair of binoculars.


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