CORTICAL REORGANIZATION AND PHANTOM PHENOMENA IN CONGENITAL AND TRAUMATIC UPPER-EXTREMITY AMPUTEES

The relationship between phantom limb phenomena and cortical reorganiz ation was examined in five subjects with congenital absence of an uppe r limb and nine traumatic amputees. Neuromagnetic source imaging revea led minimal reorganization of primary somatosensory cortex in the cong enital amputees (M=0.69 cm, SD 0.24) and the traumatic amputees withou t phantom limb pain (M=0.27 cm, SD 0.25); the amputees with phantom li mb pain showed massive cortical reorganization (M=2.22 cm, SD 0.78). P hantom limb pain and nonpainful phantom limb phenomena were absent in the congenital amputees. Whereas phantom limb pain was positively rela ted to cortical reorganization (r=0.87), nonpainful phantom phenomena were not significantly correlated with cortical reorganization (r=0.34 ). Sensory discrimination was normal and mislocalization (referral of stimulation-induced sensation to a phantom limb) was absent in the con genital amputees. The role of peripheral and central factors in the un derstanding of phantom limb pain and phantom limb phenomena is discuss ed in view of these findings.