Phantom limb pain can be defined as the feeling of uneasiness in the limb that is no longer present. Although the exact reason for this feeling is not yet known, the most likely explanation for this uneasiness can be the sudden loss of input from the severed neural cords.

According to Bo Geng, Postdoc at the Faculty of Medicine at Aalborg University in Denmark, the physical description of various body parts is organised in the brain like a map. In case of amputation, the brain no longer gets feedback from the amputated area, and therefore it tries to reprogram its signal reception map. She believes that this the most common and accepted mechanism of how phantom limb pain occurs.

Previous studies have shown significant improvement in phantom limb pain when the brain is deceived to believe that the severed limb is still attached to the body. The visual illusion about the symmetrical body can be created by placing a mirror at an angle in front of the chest. If someone assumes to perform same movements concurrently with both hands, the brain is often convinced that the amputated hand is still present. Various studies have marked the effectiveness of this method, and it has also become the basis for a new method developed by Bo Geng in alliance with Dr Martin Kraus and Master's students Bartal Henriksen and Ronni Nedergaard Nielsen from Medialogy at Aalborg University.

With virtual reality, an experience of being present in a 3-D environment can be easily formed while the illusion formed by the mirror therapy is not very convincing and can easily be destroyed. Bo Geng believes that Virtual Reality creates much more convincing alternative reality than mirror therapy.

In this novel method, the patients have to use VR goggles and a glove. Small electrodes known as stump are placed on the residual limb at the same time. After that, the sensation of the phantom hand is recreated by stimulating the stump with tiny electrical impulses. The amputee is made to play some different VR games that require doing the same task with both hands such as grasping a pole that has to be turned into various shapes or pushing virtual buttons, which finally makes amputee feel that he is using both his hands.

The first clinical test of this novel method was carried out at the China Rehabilitation Research in Beijing last fall. The clinical test included a total of 3 amputees, out of which two amputees experienced significant relief in their phantom limb pain while the last one felt a reduction in the number of phantom limbs pain attacks.

Bo Geng found these results to be encouraging. She also said that the new method only works with upper body amputees at this point, but the students at Aalborg University are developing a variant for lower body amputees as well.