Body
Mackenzie Long, a PhD candidate in Biomedical Engineering at Northwestern University, has been selected as an affiliate trainee in the Pathophysiology and Rehabilitation of Neural Dysfunction (PRND) Training Program. Her research aims to improve diaphragm recovery after nerve injury by developing strategies that promote nerve regeneration and restore respiratory function.
For people with high cervical spinal cord injuries, damage to the neural pathways controlling the diaphragm can result in paralysis and loss of independent breathing. This often leads to prolonged dependence on mechanical ventilation, which provides life-sustaining respiratory support but cannot restore voluntary diaphragm control. Using a preclinical rat model, Long studies whether an intact donor nerve can be used to restore neural input to the paralyzed diaphragm and support functional recovery.
To restore this lost connection, her work uses spinal accessory-to-phrenic nerve transfer, a surgical procedure that reroutes a functional nerve in the neck to the injured phrenic nerve. Regenerating nerve fibers then grow toward the diaphragm and form new connections with the muscle before function can return. Due to the length of the phrenic nerve, recovery for patients can extend up to a year. The longer the diaphragm remains without neural input, the more difficult it becomes to achieve complete recovery.
This work aims to understand when diaphragm function returns after nerve transfer and how recovery progresses over time. Ultrasound recordings, respiratory pressure measurements and electrophysiology are used to assess the return of movement, strength and neural activity. Together, these measures provide a more complete view of diaphragm recovery and could help guide future strategies to enhance respiratory recovery.