Thumb in cheek? Sensory reorganization and perceptual plasticity after limb amputation.

We describe a patient who initially suffered from carpal tunnel syndrome that was alleviated by surgery. Subsequently, the patient's right arm was amputated and a phantom limb emerged. Stimuli applied to different areas of the face gave rise to sensations that were referred to the phantom by precise topographic mapping. This perceptual mapping of the (phantom) hand onto the face area modelled the form of prior pathology due to carpal tunnel syndrome. The findings have implications for the relief of phantom pain.