Vestibular caloric stimulation evokes phantom limb illusions in patients with paraplegia

Study design: prospective study. Objectives: To determine the mechanisms of body illusions in paraplegia pat ients as compared with the amputee phantom phenomena. Methods: A vestibular caloric stimulation was performed in 10 consecutive p atients with complete section of the spinal cord. Perception of body, befor e and after stimulation, was classed as illusion of a normal body (lower li mbs: with normal morphological, postural and kinetic characteristics percei ved as before spinal injury), normal phantom (overly vivid perception of al l or part of the lower limbs), deformed phantom (perception of all or part of the limbs below the injury level as abnormal in shape, posture, movement or even number), or painful phantom. Results: After. vestibular caloric stimulation, nine out of 10 patients sta ted their perception of body segments below the injury level had changed to normal phantoms or to deformed phantoms (morphological, postural or kineti c changes). Among the four patients who initially had painful limbs, two st ated the stimulation greatly relieved their pain. Conclusion: The normal or deformed phantom evoked by vestibular stimulation would result fi om use of identity data or instantaneous data as is observ ed in amputees. Cerebral remapping Following deafferentation could be the o rigin of the deformed phantoms. Illusions corresponding to phenomena percei ved at the time of the accident corresponding to autobiographical engrammes do not appear to be evoked by vestibular stimulation, as is also the case in amputees.