WASHINGTON — Recovery of feeling can gradually improve for years after a hand transplant, suggests a small study that points to changes in the brain, not just the new hand, as a reason.
Research presented Sunday at a meeting of the Society for Neuroscience sheds light on how the brain processes the sense of touch, and adapts when it goes awry. The work could offer clues to rehabilitation after stroke, brain injury, maybe one day even spinal cord injury.
“It holds open the hope that we may be able to facilitate that recovery process,” said Dr. Scott Frey, a cognitive neuroscientist at the University of Missouri in Columbia.
When surgeons attach a new hand, nerves from the stump must regenerate into the transplanted limb to begin restoring different sensations, hot or cold, soft or hard, pressure or pain. While patients can move a new hand fairly soon, how quickly they regain feeling and what sensations they experience vary widely.
After all, the sense of touch isn’t just about stimulating nerves in the skin. Those nerves fire signals to a specific brain region to decipher what you’re touching and how to react. Lose a limb and the brain quickly rewires, giving those neurons new jobs. Frey’s work shows the area that once operated a right hand can start giving the left hand a boost.