virtual reality as pain management tool

[Guest guest]

August 2, 2004 Los Angeles Times

Computer-generated images offer a virtual release from severve pain

By Marsa, Special to The Times

For people in severe pain, even maximum doses of narcotics can be

inadequate — and potentially dangerous. What such patients need, some

researchers say, is a method to help control pain without using those

drugs.

Their quest for such a therapy has led them to an unlikely analgesic:

virtual reality.

Studies have shown that it can dull pain by distracting patients,

leaving less conscious attention available to process pain signals.

" Humans have a limited amount of attention, and it's hard to do two

things at once, " says Hunter G. Hoffman, a psychologist at the

University of Washington in Seattle.

In the last few years, he and his colleagues have tested virtual reality

as a pain-management tool. The results of one of their first studies —

on 12 burn patients having their bandages changed — suggested they were

onto something.

In addition to receiving painkillers, patients spent some of their time

in a virtual-reality session and some playing a video game. The game had

no effect. During the virtual-reality session, however, patients

reported that their pain lessened an average of 40% to 50%.

" It was such a dramatic drop that it was hard to believe, " says Hoffman,

head of the university's Virtual Reality Analgesia Research Center. " We

wondered if this was just a subjective reaction, or was there an actual

physical response. "

To answer this question, researchers did a second study. They used MRI

scans — and a special virtual-reality helmet that could be worn inside

the scanner — to monitor the pain centers of eight healthy volunteers'

brains. Researchers attached a device to the patients' feet, subjecting

them to painful bursts of heat for seven minutes at 30-second intervals.

The heat was administered — and scans were taken — with and without

virtual reality.

When the volunteers were immersed in the virtual reality world (floating

through a snowy canyon, flinging snowballs at such targets as snowmen

and igloos), they hardly noticed the short surges of heat on their feet.

The scans showed that their brains' ability to register pain was also

greatly diminished.

Participants reported that compared to the experience without virtual

reality, time thinking about pain dropped 35%, pain unpleasantness

decreased 36%, and the worst pain declined 23%. Physical changes were

even more dramatic: The MRI scans revealed that when participants were

inside the virtual-reality world, activity in five key pain centers

decreased, some by as much as 97%.

" Brain scans revealed that [virtual reality] actually changed the

pattern of brain activity, and the amount of pain signals that enter the

brain, " Hoffman says. Study results were published in June.

Generating such significant results using relatively primitive tools

shows the approach's promise, says , a psychologist at

the University of Washington School of Medicine involved in the study on

burn patients. Still, the cost of the technology must be reduced, and

the equipment refined, before virtual reality can become a standard pain

management tool.