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Dynamic changes in the perceived posture of the hand during ischaemic anaesthesia of the arm
Author(s) -
Inui N.,
Walsh L. D.,
Taylor J. L.,
Gandevia S. C.
Publication year - 2011
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2011.219949
Subject(s) - wrist , imaging phantom , phantom limb , phantom limb pain , medicine , sensory system , anesthesia , physical medicine and rehabilitation , anatomy , psychology , surgery , nuclear medicine , neuroscience , amputation
Non‐technical summary Even when the hand is stationary we know its position. This information is needed by the brain to plan movements. If the sensory input from a limb is removed through an accident, or an experiment with local anaesthesia, then a ‘phantom’ limb commonly develops. We used ischaemic anaesthesia of one arm to study the mechanisms which define the phantom hand. Surprisingly, if the wrist and fingers are held straight during anaesthesia, the perceived phantom hand becomes bent at the wrist and fingers, but if they are bent during anaesthesia, the final phantom is extended at the wrist and fingers. There is no ‘default’ posture for the phantom hand. Further, the hand appears to increase gradually in size as anaesthesia develops. The start of these perceptual changes occurs when input from large‐diameter sensory nerve fibres is declining. These results provide new information about how the brain generates phantom limbs.