The University Network

Aalborg University Uses Virtual Reality to Eliminate Phantom Limb Pain

Soon there might be a surefire way to eliminate phantom limb pain. Researchers at Aalborg University in Denmark reported, based on their new study, that Virtual Reality technology can be used to help amputees.

Phantom limb pain is felt by those who have lost an arm, leg, or other body part. It can be felt as a tingling, cold, hot, or any other sensation a person would have felt before being amputated. This is a phenomenon that is common amongst amputees but something that doesn’t have a clear explanation. Bo Geng, one of the researchers involved in the study and a postdoc at the Faculty of Medicine at Aalborg University, gave Science Daily this explanation: “The tactile representation of different body parts are arranged in the brain in a sort of map. If the brain no longer receives feedback from an area, it tries to reprogram its signal reception map. That is the most common conception of how phantom limb pain occurs.”

TUN was able to speak with Geng about this study that could affect millions of amputees.

Originally, I planned to use a mirror, placed vertically in front of the patients, to create a visual illusion that they regain both hands,” she said.

Mirror therapy is a popular treatment used to relieve phantom limb pain, which involves amputees trying to trick their brain by performing an action with their intact leg, arm, or hand in front of a mirror. The idea is that your brain will see the illusion and believe that it is the amputated body part that is performing the action. You can see an example of this form of therapy in the video below.

But mirror therapy has its limitations. Geng finds the mirror therapy exercises “limited” because “the patients have to physically sit behind the mirror and look into the mirror during therapy.” She concluded that “Virtual Reality technology can resolve the issue.”

While this study isn’t the first to use Virtual Reality, Geng says there’s one significant difference between this study and others. “The major difference is that, our study integrates tactile feedback when the patients are playing a virtual game,” she said. “The tactile feedback, generated by transcutaneous electrical stimulation to the residual limb, may positively affect the brain area associated with phantom limb pain.”

With this new method, amputees put on Virtual Reality goggles and a glove. Then small electrodes are placed on the residual limb also known as the stump. The amputee then plays a number of games that involve using both hands, such as pressing virtual buttons or grabbing a pole, and by stimulating the stump with tiny electrical impulses, researchers hope to recreate the sensation of the missing hand. This creates a more realistic environment to trick the amputee’s brain.

The Aalborg University researchers tested this method at the China Rehabilitation Research in Beijing last fall. In this small trial, two out of three amputees felt their phantom limb pain ease and the third reported a decrease in frequency of phantom limb pain attacks. This is a good first step, but Geng knows there’s still more research to be done.

Next step we hope to validate the approach by testing it in more phantom limb pain patients,” said Geng. “The ultimate goal is to develop an effective phantom pain management tool, which can be used at home, and affordable.”