Nerve bypass 'could end paralysis'

Thousands of people could regain the use of paralysed limbs thanks to a pioneering technique, scientists claim.

The technique uses the body's nerves to bypass spinal injuries and US researchers believe the treatment could help thousands of people to regain feeling, and possibly even the use of paralysed limbs.

The researchers have shown that nerves can be used to circumvent spinal damage and reconnect the brain to the body, according to a report in New Scientist.

The procedure, successfully used in experiments with rats, worked on similar principles to heart bypass surgery, where veins from a patient's leg are used to get around an artery blockage.

It raised the prospect of the first human trials within five years, offering hope to the 40,000-plus people in the UK with spinal cord injuries.

John Martin, a neuroscientist at Columbia University in New York, cut away a nerve in rats, from just above the injury, that normally stretches into the body to control abdominal muscles and reattached it to the spine below the injury.

When the team examined the nerve under a microscope two weeks later, they found it had sprouted new extensions which had begun to form connections, or synapses, with the motor nerves in the isolated lower spine.

Zapping the spinal cord above the injury made the lower limbs of the rats twitch, showing that motor signals had begun once again to pass along the entire length of the spine.

Mr Martin said: "What we want to do is plug in new connections to bypass the damaged region.

"We know the nerves can make new connections to muscle, so we asked whether it's possible for them to also connect with spinal cord neurons isolated through injury."

He told the Guardian: "What we've documented is that we've reconnected the nervous system above the injury with below the injury in a robust way.

"The hope is to try to overcome some of the paralysis."

Reconnecting a single nerve would not be sufficient to reactivate all of a patient's lost functions, and the patient would have to decide with their doctor what was most important to improve their quality of life.

Mr Martin said: "For example, in a quadriplegic with limited upper extremity mobility, increasing the strength of shoulder muscles is very helpful because that could help their transfer from a wheelchair to a bed or toilet - it gives them independence."

Patrick Anderson, professor of experimental neuroscience at University College London, told the newspaper the findings were exciting, but said there was still much research to be done before the technique could be tried in humans.

Mr Anderson, who was not involved in the research, said: "It's quite an exciting response, it's novel and no one's achieved quite that before."

Mr Martin said the technique needed much more development, but if all went well trials in humans could start in as little as five years.