Rerouting nerves to paralyzed sites in patients with spinal cord injury may provide significant functional improvement in the upper limb and hand function, reports a new study published in The Lancet. The study showed that nerve transfers could restore hand function and elbow extension in 13 young adults with traumatic spinal cord injury.
“Surgery to attach functioning nerves above the injury to paralyzed nerves below it, combined with 2 years of physical therapy, helped tetraplegic patients grasp, pinch, and open and close their hands and improved their ability to propel their wheelchair and transfer into a bed or a car”, reported the co-author, Natasha van Zyl, Austin Health, Australia, in a news release.
The prospective case series recruited 16 individuals with early (less than 18 months post-injury) cervical spinal cord injury. The patients had cervical spinal cord injury of motor level C5 and below and had been referred for upper extremity reanimation from April 2014 to November 2018. The subjects belonged to an average age of 27 and most injuries were reportedly the result of motor vehicle accidents or sports.
Surgeons performed single or multiple nerve transfers in one or both upper limbs to restore elbow extension, grasp, pinch, and hand opening by taking working nerves of expendable muscles and attaching them to nerves of paralyzed muscles.
The surgeons performed an over all 59 nerve transfers, working on 27 limbs. They also combined nerve transfers with tendon transfers in 10 patients.
After surgery 13 participants showed improvements during the follow up at 24 months compared with baseline in total scores for all primary outcomes including action research arm test (median score 34.0 vs 16.5), grasp release test (median score 125.2 vs 35.0), and spinal cord independence measure (mean score 39.3 vs 31.2), reported the study.
“Nerve transfers are a safe and feasible surgical option for restoring upper limb function in tetraplegia and can be safely and effectively combined with tendon transfers,” said van Zyl.
However, nerve transfers have disadvantages, including a long runway to see results as it can take months to see new motion and years to achieve full strength. “Nerve transfers sometimes fail, and patient satisfaction does not always correlate directly with measurable gains in strength or function,”observed Elspeth Hill, MD, PhD, and Ida Fox, MD, both of Washington University in St. Louis, in an accompanying editorial in The Lancet.