It's been a good news week for those suffering debilitating spinal injuries. First we looked at a breakthrough that enables quadriplegic patients to move robotic arms using just their thoughts and now, in related news, surgeons at the Washington University School of Medicine have reported the successful rerouting of working nerves in the upper arms of a quadriplegic patient, restoring some hand function.
Prior to the procedure, the patient had no hand function due to a spinal cord injury at the C7 vertebra, which is the lowest bone in the neck. However, because associated nerves attach to the spinal cord above the injury and connect to the brain, the patient had shoulder, elbow and some wrist function - a necessary requirement for the procedure to work.
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Susan E. Mackinnon, MD, and her surgical team connected a non-working nerve in the upper arm (responsible for controlling the ability to pinch), to a working nerve that drives one of the two muscles that flex the elbow. This restored the patient’s ability to pinch with their thumb and index finger.
Dr. MacKinnon, who originally developed the procedure for patients with arm injuries that have resulted in damage to the nerves that provide the ability to flex the thumb and index finger, says the surgery isn’t particularly expensive or complex.
This is not only because it doesn’t involve operating directly on the spinal cord at the site of the injury, but also because the working and non-working nerves targeted run parallel to each other, making it possible to tap into the functional nerve and reroute the signals to its functioning neighbor.
However, Dr. Mackinnon points out that the restoration of hand function wasn’t instantaneous and the patient required intensive physical therapy, as they had to retrain their brain to recognize that nerves that used to bend the elbow now provided a pinch of the thumb and index finger.
Although this was the first time Dr. MacKinnon had applied her peripheral nerve technique to treat a sufferer of spinal injury, she and her team don’t believe there is a limited time window during which other patients with a similar spinal cord injury must be treated for the technique to be successful.
In fact, the quadriplegic patient who underwent the procedure at Barnes-Jewish Hospital was injured almost two years prior. Provided the nerve remains connected to the support and nourishment of the spinal cord, it and its associated muscle should remain healthy, even years after an injury.
The case study was published online this week in the Journal of Neurosurgery. Dr. MacKinnon has also made detailed information available for potential patients interested in nerve transfer surgery for C6 and C7 spinal cord injury here.
Here’s a video describing the procedure and showing the results: