Sensory disorganization and perceptual plasticity after limb amputation: a follow-up study.

We report a follow-up study of a patient who initially suffered from carpal tunnel syndrome in the right hand, that was alleviated by surgery. Subsequently, the patient's right arm was amputated, and a phantom limb was experienced. Originally, stimuli applied to different areas on the right side of the face evoked sensations that were referred to the phantom by precise topographic mapping. On follow-up, one year after our initial studies, the topography of referred mapping had become extremely disorganized. Furthermore, a new, equally disorganized, pattern of referred sensations was now found upon stimulation of the left side of the face.