Immersion in virtual reality eases pain

New York: An aspirin or a video game?

Distracting patients by immersing them in a virtual world, sometimes by using a video game, appears to help reduce pain - even in elderly patients who aren't used to such exposure, according to a US study.

"I was surprised to see the level of analgesic response that the elderly patients demonstrated, because these subjects had little or no previous experience with video games or virtual reality (VR) distraction, unlike our younger subjects," said Sam Sharar, an anesthesiology professor at Washington University, who worked on the study.

The VR therapy involves a video game on a head-mounted display developed by Hunter Hoffman, a cognitive psychologist and researcher at the University of Washington.

In the experiment, presented at the annual meeting of the American Pain Society, 25 adults aged 60 and older were randomly assigned to either a low-immersion or a high-immersion VR environment, using a program called SnowWorld.

The high-immersion group moved along a virtual path through an icy canyon populated by snowmen, igloos, penguins, mammoths and fish, viewing it all though a display that blocked most of their vision of the real world.

They could look around to see sky above, canyon walls to their left and right, and below them a river teeming with mammoths and fish. With the click of a mouse they could toss snowballs at all the creatures.

They also heard sound in stereo, such as the roar of a mammoth when a snowball struck, the splash of a snowball in the river, background music, and other effects.

The low-immersion group used the same program with a display that did not block out the real world. Also, the image resolution was reduced, there were no sound effects, and no game-like interaction with the world - simply a virtual walk on a path through a snowy canyon.

Sharar's team performed two thermal simulations of the pain of a lumbar puncture, otherwise known as a spinal tap, for 30 seconds, once while subjects were not immersed in the VR program, and again when they were.

"Results showed a significant reduction in sensory, emotional, and cognitive pain components with VR treatment of either kind," the researchers said in the abstract for their presentation.

They added that the subjective analgesia effect was significantly greater in the high-immersion group.

This sort of therapy may be as effective at controlling pain as an intravenous dose of hydromorphone, a very potent opoid analgesic, according to a study by Sharar and colleagues published in 2007. When the two are combined, the effect is compounded.

The current study did not compare the effect of VR in different age groups, but Sharar has carried out similar, not-yet-published studies on college-aged and middle aged participants, and drawn some rough generalizations.

The subjective pain reduction was similar in all groups, and even slightly better in the elderly compared to college-aged participants, he said.

The VR therapy is now used in a handful of US burn centers, and it has also been used with patients who have psychiatric disorders such as phobias and symptoms of post-traumatic stress disorder.