Illusion of body normality in patients with amputation of limb or total section of spinal cord

Phantom limbs in amputees, or body illusion in hemlolegics, have been the s ubject of wide ranging descriptions. The detected abnormalities involve mor phological, postural and/or kinetic features. The aim of this prospective s tudy carried out in 25 amputees and 10 adult paraplegics was to describe th e typology of these perceptions. Data were collected from free and semi-dir ective investigations before and after caloric vestibular stimulation, Ampu tees and paraplegics perceived normal, deformed and painful body phantom se gments, reffered perceptions and "normal limbs" which took on the request p osture considering the general body position (illusion of body normality). This perception corresponds to an image of the body, such as it should be a nd not such as it is. In amputees, the limb follows the movements of the pr othesis. These perceptions conform quite well reality so that the loss of t he paralyzed limb is not perceived as a missing limb. This illusion of body normality should be distinguished from the normal phantom limb, characteri zed by a stronger perception of the lost limb compared with the other. In b oth amputees and paraplegics, vestibular stimulation can generate or modify phantoms limbs or body illusion and can abolish painful phantom limbs. The neuromatrix, which rebuilds body representations, could get its informatio n from reorganized cortical areas (instantaneous body image), autobiographi cal engrams (painful phantoms limbs), or innate engrams (identity body sche ma) that, via congruence mechanisms, could be identified as a somatic refer ence, particularly for motor programming. This interpretation is compatible with current knowledge and suggests how amputees can easily use a prothesi s.