Virtual solutions to phantom problems: Using immersive virtual reality to treat phantom limb pain

Phantom limb pain (PLP) is a common consequence of amputation, and many persons with amputations experience vivid sensations of pain in the absent body part. PLP can persist for many years post-amputation and is very difficult to treat, since its aetiology is hard to determine. However, converging lines of evidence demonstrate that when visual feedback is manipulated appropriately to represent movement of an amputee's absent limb, it can evoke kinesthetic sensations of movement in that limb and decrease PLP. Most notably, the mirror box-where a mirror is placed vertically in front of the person with an amputation-is used in such a way as to reflect the image of an intact limb onto the phenomenal space of the absent or phantom limb. When amputees orient towards this mirror image kinaesthetic sensations can be evoked in the muscles and joints of their phantom limb, and PLP can be decreased. Some researchers have highlighted limitations in the flexibility of the mirror box in providing a fully robust illusion of an absent limb as intact. Recently, three research groups have developed virtual reality systems informed by mirror-box work for the treatment of PLP. Although similar in intent and design, these systems have subtle differences. This chapter will outline these systems along with empirical findings, with a particular emphasis on the authors' own virtual reality system. © 2010 Springer Science+Business Media, LLC.