The relationship of perceptual phenomena and cortical reorganization in upper extremity amputees

In this study 16 unilateral upper extremity amputees participated in a comp rehensive psychophysiological examination that included the assessment of p ainful and non-painful phantom and stump sensations, thermal and electric p erception as well as two-point discrimination thresholds, the detailed anal ysis of referred sensation and the measurement of reorganizational changes in primary somatosensory cortex using neuroelectric source imaging. Reorgan ization of the primary somatosensory cortex was associated with increased h abitual phantom limb pain, telescoping, non-painful stump sensations and pa inful referred sensation induced by painful stimulation. It was unrelated t o non-painful phantom sensations, non-painful referred sensation elicited b y painful or non-painful stimulation, painful referred sensation elicited b y nonpainful stimulation, perception thresholds and stump pain. These data substantiate the hypothesis that painful and non-painful phantom phenomena are mediated by different neural substrates. (C) 2001 IBRO. Publ ished by Elsevier Science Ltd. All rights reserved.