A paralyzed man has regained the use of his hand after he had a pioneering operation to bypass damage to his spinal cord.
The 71-year-old patient injured the lowest bone in his neck in a car crash in June 2008.
The damage to the C7 vertebra left him without the use of his legs and only limited shoulder, elbow and wrist function.
He also lost the use of his hand because while the nerve circuit in his hand was intact, the connection between his brain and digits had been lost.
Surgeons at Washington University School of Medicine in St Louis restored this link by rerouting working nerves in his upper arm.’
The patient can now pinch his thumb and index fingers together using nerves that once told his brain to bend at the elbow.
Senior researcher Dr Ida K Fox said, “This procedure is unusual for treating quadriplegia because we do not attempt to go back into the spinal cord where the injury is. Instead, we go out to where we know things work – in this case the elbow – so that we can borrow nerves there and reroute them to give hand function.”
The successful operation means the patient can now feed himself and even write.
“Many times these patients say they would like to be able to do very simple things,” Dr Fox said.
“If we can restore the ability to pinch, between thumb and index finger, it can return some very basic independence.”
The surgery was developed and performed by Dr Susan E. Mackinnon. Specializing in injuries to peripheral nerves, she has pioneered similar surgeries to return function to injured arms and legs.
She said hand function was not restored right away and that the patient had to undergo intensive physical therapy to retrain the brain to understand how the role of the nerves had changed.
Dr Mackinnon said another patient with a similar injury could be treated at any time as their case study received the surgery two years after his accident.
She said nerves run out from the spinal cord ‘like spaghetti’ to the tips of the fingers and toes.
Nerves remained healthy as they were still connected to the spinal cord, however the nerves could no longer ‘talk’ to the brain because the spinal cord injury blocks them.
To detour around the block in this patient’s C7 spinal cord injury and return hand function below the level of the injury, Mackinnon operated in the upper arms.
There, the working nerves that connect above the injury and the non-working nerves that connect below the injury run parallel to each other, making it possible to tap into a functional nerve and direct those signals to a non-functional neighbor.
In this case, Mackinnon took a non-working nerve that controls the ability to pinch and plugged it into a working nerve that drives one of two muscles that flex the elbow.
After the surgery, the bicep still flexes the elbow, but a second muscle, called the brachialis, that used to also provide elbow flexion, now bends the thumb and index finger.
“This is not a particularly expensive or overly complex surgery,” Dr Mackinnon said. “It’s not a hand or a face transplant, for example. It’s something we would like other surgeons around the country to do.”
Attribution: Claire Bates