Role of Cortical Plasticity in Recovery of Function Following Allogeneic Hand Transplantation.

摘要

In Year 1, we have obtained permissions for this work, completed piloting testing and collected data on several hand transplant and hand replant recipients as well as matched controls at multiple time points. Our preliminary findings indicate that: 1) Hand transplant recipients utilize the former cortical sensorimotor hand territory when using the affected hand. However, they continue to exhibit strong evidence for persistent, amputation-related, cortical reorganization. These persistent changes appear to diminish with recovery of hand function, suggesting that cortical reorganization is an important target for post-transplant rehabilitation. Hand transplant recipients provide a unique opportunity to investigate whether the central reorganizational changes that follow amputation are reversed when afferent and efferent signals between hand and brain are restored, and whether these changes are related to recovery of hand function. Our preliminary functional magnetic resonance imaging (fMRI) data suggest that areas of the sensory and motor cortex devoted to representing the hand prior to amputation come to represent the transplanted hand, even when received decades after amputation. We also find evidence that changes in cortical organization associated with unilateral hand amputation may not be fully reversed even a decade after transplantation; transplant recipients, like amputees, show increased activity in the former hand territory during movements of the adjacently represented face and of the intact hand. Importantly, the level of functional recovery appears to be associated with greater activity in the former hand territory when using the transplanted hand and with less evidence of persistent cortical reorganization. On the basis of our preliminary data, we hypothesize that experience-dependent central (brain) changes play a key role in the functional improvements known to continue throughout at least the first decade following hand transplantation, long after