Hand transplantation has been successful in restoring function in a select group of people, but the mechanisms by which the central nervous system integrates a new hand are unknown. We used event-related functional magnetic resonance imaging (fMRI) to assess brain activation related to actual and imagined hand movement, for a recipient (female, 60 years of age) of bilateral hand transplants. Investigation of a patient-specific network of sensorimotor cortical regions was conducted at a preoperative session, as well as at three assessments conducted over a 16-month, post-transplantation period. We detected significant activation for both actual and imagined hand movement, relative to a rest baseline, for both transplanted hands, at all three postoperative sessions. Activation was higher for actual movement than for imagined movement. Across the postoperative period, movement-related activation decreased in magnitude, relative to an imagined-movement baseline. Movement-related activation also became more focused, postoperatively, on hand-related brain regions, in contralateral sensorimotor cortex. Some movement-related brain activation was relatively stronger for the right hand, postoperatively, consistent with the fact that the patient had been right-handed, preoperatively. To our knowledge, this is the first hand-transplant recipient to exhibit more pronounced brain activation, post-transplantation, for actual movement relative to imagined movement. Overall, the findings suggest that, following hand transplantation, sensorimotor cortex returns to a more canonical functional organization, similar to that of healthy individuals.
David J. Madden, Jenna L. Merenstein, Todd B. Harshbarger, and Linda C. Cendales (2025). Brain activation for actual and imagined hand movement following bilateral hand transplantation. Cortex, 193, 57-73. https://doi.org/10.1016/j.cortex.2025.09.013