May 15, 2012 -- Surgeons in St. Louis have restored partial function to a 71-year-old man's hands, which had been paralyzed following a spinal cord injury sustained in a car accident two years before the surgery.
The man, who remains paralyzed from the waist down, can now write and feed himself. A case report published today in the online edition of the Journal of Neurosurgery describes the procedure.
"This is not a small step, this is a significant step," says UCLA neurosurgeon Nader Pouratian, MD, a specialist in nerve and movement disorders who was not involved in the case. "It is a novel application of an established surgical technique. It goes beyond what we thought was possible before."
The established technique that Pouratian refers to is one in which working nerves taken from one muscle replace damaged nerves in another. Such nerve transfers can restore arm and shoulder movement following what's called peripheral nerve injury, for example.
In this case, however, the damage was not to the nerve. It was to the spine.
"The nerve and muscle were still healthy, but the spine injury was blocking communication with the brain," says Ida Fox, MD, a plastic and reconstructive surgeon at Washington University School of Medicine in St. Louis and a colleague of the surgical team that performed the operation.
The patient's injury had left him without the use of his hands, but he retained a good deal of upper body function. That gave his medical team, led by Susan E. Mackinnon, MD, a pioneer in nerve transfer techniques, some materials to work with. They focused on the nerves that control elbow movement.
One of those nerves, the brachialis nerve, is considered to be redundant. That is, another nerve performs the same job, so no function would be lost if the brachialis nerve were to be moved. That allowed the surgeons to take it and attach it to the anterior interosseous nerve, which controls the thumb and the index finger.
"They're basically stealing a nerve and plugging it into another nerve that is below the level of the spinal injury," says Lewis Lane, MD, chief of hand surgery at North Shore University Hospital and Long Island Jewish Medical Center in New York. Lane was not involved with the surgery.
After surgery, the patient underwent many months of hand therapy. One essential part of that effort involved teaching his brain that the nerves once connected to his elbow now served his hands. Eventually, he was able to perform a pinching motion, which allowed him to feed himself and hold a pen.
"Every patient says they want to eat and write without assistance," says Fox. "That's what pinch gives you."
The Future of the Procedure
It's unknown how many patients might benefit from a similar procedure. The type and location of their spinal injury would determine their eligibility. And so far, only one patient has undergone this operation. (Fox will soon perform the surgery on a second patient.)
"It is a terrific advance but not widely applicable," Lane says. "Still, this really advances the field and shows how useful this technique can be in specific cases."
Pouratian agrees that the procedure will help only a limited number of spinal cord patients, and he cautions against drawing too many conclusions from a single case report. But he is nevertheless excited by what the new technique may allow.
"It definitely shows that the technique, which has been well-established for treating peripheral nerve injury, can be extended to a new patient group," Pouratian says. "It has the potential to treat a much larger group of patients."