(May – 2025) For Tommy, a 28-year-old man living with tetraplegia from a motor vehicle accident, the ability to open a medicine bottle or grip his wheelchair’s hand rims represents more than medical progress—it’s a restoration of independence.
“Literally everything changed,” he says, describing life after participating in a nerve transfer surgery study led by S. Shelby Burks, M.D., Assistant Professor Department of Neurological Surgery and a The Miami Project to Cure Paralysis scientist.
While peripheral nerve transfers have been an existing option for people living with spinal cord injury (SCI), the federally funded multi-site study, led locally by site-PI Dr. Burks, adds key innovation in the postoperative neurorehabilitation to maximize functional gains that might only be realized by the combination of surgery and rehabilitation.
Dr. Burks’ trial targets individuals with high tetraplegia in the sub-acute to the early-chronic phase, a critical period when neuroplasticity remains primed for retraining. The surgery involves rerouting operational nerves from above the injury site – often the triceps or biceps – to dormant nerves that would otherwise be controlling hand muscles if not for SCI.
The surgery, a procedure that has existed for some time, involves boldly cutting a working nerve from a nerve root exiting the cord above where SCI disrupts signals, and suturing that nerve into a nerve that originates below the SCI. Because nerves below the level of injury are not dead but simply inactive, the rerouted rostral nerve has a channel down which it can regenerate into a precise target. In Tommy’s case, muscles that allow his fingers to grasp again.
While the surgery immediately connects the nerves, the regenerative process—unique to peripheral nerves only once they leave the spinal cord—occurs at a rate of ~1 inch per month. “It didn’t make me upset, because I was already assuming that this isn’t going to work instantly,” Tommy said when reflecting on the duration between the surgery and regaining function.
A scientific target addressed by this study is optimization of the regenerative environment in this post-operative window, to maximize the functional gains resulting from the regeneration that establishes new connection.
The first nerve transfer surgeries were performed in the 1960s, but despite an effort in the early 1980s they remain underutilized to our current time. This trend, which this multi-site study led by Wilson Z. Ray, M.D. at Washington University School of Medicine aims to reverse, likely occurred because while the surgical procedure restores anatomical connectivity, optimization of post-operative regenerative environment has yet to be fully explored. Thus Dr. Burks team employs intensive post-operative neurorehabilitation in collaboration with Matija Milosevic, Ph.D., Assistant Professor of Neurological Surgery and Biomedical Engineering and principal investigator of the Neuromodulation Engineering & Therapeutics (NeuroMET) Lab.
The study puts to the test the hypothesis that combinatorial neurorehabilitation unlocks the potential of the surgery. As a case, Tommy’s progress is illustrative of the incremental but transformative potential of this combined surgery and rehabilitation. At four months post-surgery, he noticed the first flicker of movement in his left hand. Tommy recalls, “I was laying in my bed trying to open my hand, and it just barely started to move. And that was my first realization that it’s working, because they didn’t move at all before. So even just that slight flicker was very like, it’s working!”
By seven months, he could open his fingers readily—a milestone he says changes “literally everything” about his daily life. “Before, I used my palms to push my chair, now I can grip the rims,” Tommy said while also listing a litany of tasks he can perform that were unavailable to him before participating in the study, everything from independently eating to self-administering his daily medications.
With early success in restoring hand function in tetraplegia, Dr. Burks’ team is exploring lateral translation of the approach to other diagnoses such as brachial plexus injuries in collaboration with the plastic surgeons who routinely handle these cases. Concurrently, much innovation remains to be discovered in the optimization of pre- and postoperative rehabilitative techniques employed in SCI nerve transfers.
While not yet enacted, the trend Drs. Burks and Milosevic might someday layer therapeutics onto the process, combining a variety of neuromodulation devices developed in Dr. Milosevic’s NeuroMET Lab with the existing surgery and neurorehabilitation.
If you have an interest in this combinatorial approach, stay tuned and reach out to The Miami Project’s Office of Education and Outreach for any updates or to see if you, or someone you know, qualifies for existing studies.