Surgeons in Australia have successfully performed the operation in 13 young adults who were paralysed in both their arms and legs (tetraplegia) before their injury.
By detaching active nerves from muscles in the shoulder or elsewhere in the upper arm, the nerve ending can be attached to “reanimate” paralysed forearm muscles, restoring grip in the hand, wrist control and elbow extension.
After two years of intensive physiotherapy, participants were able to write, apply make up, handle money, and perform other tasks requiring fine motor skills that vastly improve their quality of life.
“I have one patient where it wasn’t just life changing, it was life saving,” Dr Natasha van Zyl from Austin Health Hospital in Melbourne, who led the research, told The Independent.
“He had decided if [nerve transfer] didn’t make a big enough difference he was going to check out.
“Luckily it did make a difference, he is back at work, taking his child out to the movies. He would have been dead otherwise.”
Other patients have told Dr van Zyl that the surgery has allowed them to go to university and complete a degree, and given them the independence of driving a car.
“If you want to know what difference it makes, just try without using your hands for 10 minutes,” Dr van Zyl added.
“Everything we do, we do with our hands.
“We also interact with them: we touch, we hold hands, those social functions which leave people without hand function feeling quite isolated.”
The study, published in The Lancet medical journal, is the largest of its kind, and was hailed as a “major advance” by researchers.
Some 59 nerve transfers were completed in 16 people with an average age of 27, who suffered spinal cord damage to the neck less than 18 months previously – usually after sporting or road accidents.
However in three people the procedure failed, leaving two participants experiencing a permanent decrease in sensation where the functional nerve was removed.
Nerve transfers allow for more natural and precise “pinch” movement, while tendon transfers help restore a powerful “grasp” for lifting heavier objects.
“Participants consistently reported that that they liked both hands for different reasons and would not choose to have two hands reconstructed in the same way,” the authors said.
Up until now, tendon transfers have been used to reconstruct upper limb function, with working muscles “surgically re-sited” to replace paralysed ones.
The nerve transfer surgery allows for the direct reanimation of the paralysed muscle, can reanimate more than one muscle and means less recovery time.
The procedure is most effective when performed within six to 12 months of the paralysis and it can take months for nerve regrowth into the paralysed muscle to occur.
It also takes time to retrain the brain to associate the action of the old nerve ending with the new hand movements.
For 10 people nerve transfer was combined with more established tendon transfers, which allowed them to perform different functions with each arm.
Independent experts said nerve transfer wasn’t a “cure” and didn’t return participants to the level of control they had pre-injury. Nevertheless the findings were an important demonstration of its benefits.
“It highlights that the restorative improvements are long lasting and lead to a greater level of independence for these individual,” said Dr Mark Dallas, from the University of Reading.
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