Multimodal virtual reality platform for the rehabilitation of phantom limb pain

Amputees usually perceive vivid awareness of their lost body parts after the amputation (phantom limbs). Phantom limb pain (PLP) is intense pain that is felt in the phantom limb. The mechanism of PLP is still unclear, but the major hypothesis is that it is derived from dysfunction of the brain. There are a few neurorehabilitation techniques using a mirror or virtual reality (VR) that present the visual image of a phantom limb to the patients, and this produce the movement perception of their phantom limb. Here, we developed a multimodal (visual, auditory, and tactile) VR system to obtain the perception of voluntary phantom limb movements. We applied this system to five PLP patients for three tactile feedback conditions as a pilot study. In conclusion, four of the five patients reported pain amelioration, up to 86% decrease in the tactile feedback condition. In addition, our results demonstrated that the best suited condition of feedback-sense modalities depends on the patient. These results suggest that this system can be applied to a rehabilitation platform to offer flexible neurorehabilitation regimens for each patient.