Plastic changes in the brain after human hand allotransplantation

The physiological mechanism after hand transplant was investigated using magnetic resonance imaging and transcranial magnetic stimulation. Somatosensory and motor representations of the upper arm proximal to amputation occupied the hand area before surgery and moved back toward normal position after the surgery. The absent cortical inhibition with amputation increased gradually after surgery. The cortical plastic changes preceded functional recovery and can be used to monitor functional restoration after hand transplant.

Methods
This exploratory case study revealed physiological correlates of functional recovery after hand transplant. Changes in somatosensory cortex and primary motor cortex 4 months before and up to 6 months after hand transplantation surgery were compared. Somatosensory map of different body parts from cutaneous electrical stimulation was obtained using functional magnetic resonance imaging 4 months before and 6 months after the transplant surgery. Changes in motor cortical representations for different muscles and changes in the motor cortical circuits 4 months before and up to 6 months after the surgery were tested with transcranial magnetic stimulation.