Long-range plasticity between intact hemispheres after contralateral cervical nerve transfer in humans.
OBJECTIVE
Peripheral nerve injury in a limb usually causes intrahemispheric functional reorganization of the contralateral motor cortex. Recently, evidence has been emerging for significant interhemispheric cortical plasticity in humans, mostly from studies of direct cortical damage. However, in this study, a long-range interhemispheric plasticity was demonstrated in adults with brachial plexus avulsion injury (BPAI) who had received a contralateral cervical nerve transfer, and this plasticity reversed the BPAI-induced intrahemispheric cortical reorganization.


METHODS
In this study, 8 adult male patients with BPAI were studied using PET scanning.


RESULTS
The results indicated that the right somatomotor cortices, which may contribute to the control of the injured limb before brachial plexus deafferentation, still played an important role when patients with BPAI tried to move their affected limbs, despite the fact that the contralateral C-7 nerve transfer had been performed and the peripheral output had changed dramatically. Such findings are consistent with the results of the authors' previous animal study.


CONCLUSIONS
The brain may try to restore the control of an injured limb to its original cortex area, and a complicated change of peripheral pathway also can induce long-range interhemispheric cortical reorganization in human motor cortex.
Department of Hand Surgery, Huashan Hospital, Shanghai, People's Republic of China.
Chuan-Tao
CT
Zuo
Xu-Yun
XY
Hua
Yi-Hui
YH
Guan
Wen-Dong
WD
Xu
Jian-Guang
JG
Xu
Yu-Dong
YD
Gu
D000328:Adult; D000344:Afferent Pathways / Q000503:physiopathology; D001917:Brachial Plexus / Q000293:injuries* / Q000503:physiopathology / Q000601:surgery*; D004292:Dominance, Cerebral / Q000502:physiology*; D019788:Fluorodeoxyglucose F18; D007839:Functional Laterality / Q000502:physiology; D006225:Hand / Q000294:innervation*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008297:Male; D008475:Median Nerve / Q000503:physiopathology / Q000601:surgery; D009044:Motor Cortex / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D016067:Nerve Transfer / Q000379:methods*; D009473:Neuronal Plasticity / Q000502:physiology*; D049268:Positron-Emission Tomography; D013003:Somatosensory Cortex / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D013126:Spinal Nerve Roots / Q000293:injuries* / Q000503:physiopathology / Q000601:surgery*; D014459:Ulnar Nerve / Q000637:transplantation; D014953:Wrist / Q000294:innervation*; D055815:Young Adult
D019788:Fluorodeoxyglucose F18