A US professor has carried out experiments using laser therapy. Her findings may lead to a cure for those who have suffered paralysis from spinal cord injuries, writes Noel Young
For the first time ever, a living spinal cord has been rejoined. It took place at a US military university and raises hopes that paralysed people will be able to walk again. Even more incredible, it was done without surgery.
The technique used low-powered lasers to repair cut spinal cords on paralysed rats. It worked so well that it's going to be tested on human beings this year.
Prof Juanita Anders, lead researcher on the project at the Uniformed Services University of the Health Sciences in Maryland, says experiments completed on human cadavers show the healing power of the laser will also be able to reach through the thicker human spinal cord and effect repairs.
Prof Anders says some of the team's advances in light therapy are "almost too incredible to believe".
"The conservative researcher in me doesn't want to say we have connected a living spinal cord. But we have."
The university researchers are concentrating on acute injuries that have just happened, rather than long-term chronic injuries.
They are confident, however, that the more complex treatment of old injuries - such as those sustained by Superman actor Christopher Reeve in 1995 - are also within their grasp.
Dr Jackson Streeter, whose San Diego firm has licensed the technology developed by Prof Anders said: "If we could have lasered Christopher Reeve in the days immediately after his injuries, he might be walking today."
Reeve was injured when he fell from his horse. Since then he has inspired sufferers worldwide by his courageous fight back. His rigorous exercise regime has seen him regain some mobility in his limbs and fingers, although he still requires a machine to assist his breathing.
The military university where the laser work is taking place is funded by the US Defence Department. Nine hundred students, mostly in uniform, receive free medical training in return for a pledge to serve time in the US's armed forces. The university is part of the heavily guarded campus of Bethesda Naval Hospital, where President Bush is examined regularly.
The laser breakthrough work was carried out by Prof Anders, her associate Dr Kimberley Byrnes, and six other team members.
Using lasers made by a small Scottish company, Thor International, the team was able to restore complete mobility to 10 white laboratory rats that had had their spinal cords cut.
Ten other rats, that also had their cords cut to act as the "control" in the experiment, were not given the light treatment and remained paralysed.
"The 10 animals chosen received daily doses of light for about 50 minutes a day for two weeks," explained Prof Anders. "Nine weeks later, when they were tested, they had recovered their mobility."
Prof Anders said the project started 17 years ago with funding from Ronald Reagan's Star Wars programme.
"We were called to a conference and asked to put up bio projects involving the use of lasers. My project won funding of $60,000 a year and we were on our way."
Prof Anders first established that low-powered laser seemed to have the ability to regenerate cells in facial paralysis. Eventually her work led to spinal cord injuries, which have until now been catastrophic for humans and animals because the nerves in the central nervous system fail to regenerate, leaving the victim paralysed.
Dr Byrnes joined the Anders team five years ago as a post-graduate student determined to work on light therapy. She knew the problems of spinal injuries.
"Things are made even worse because when the immune system kicks in, it causes greater impairment then the initial injury," Dr Byrnes said. "However, light therapy had already proved effective in skin nerve regeneration. And we knew that light had the ability to partly suppress the immune system."
The challenge facing the scientists was to decide just what wavelength of light might be effective and how to establish that it was actually penetrating the flesh and reaching the broken spinal cord.
That was where the lasers produced by Thor came into their own. Thor employs just three people, designing and building the instruments.
Thor managing director Mr James Carroll said: "We produce only 200 machines a year and they sell from $3,000 to $15,000. But obviously the market is growing."
Having settled on a wavelength close to infrared, the scientists had to find out if the light did actually penetrate the rats' bodies to the depth of the cord - something other doctors strongly doubted.
To measure their success in reaching the broken spinal cord, the Anders team used a hypodermic needle to insert a fibre optic cable no thicker than a fishing line into the animals' backs.
"This was the nearest thing to invasive surgery that we carried out," said Prof Anders. "Once we established that the light was reaching the wound, we didn't have to do it again.
"We would cut the spinal cords, enough to cause paralysis in the feet of the animals, but not their legs, sew the animals back up, close the wound, and put the light right over the injury site for 50 minutes a day for 14 days."
Two months after the surgery and the laser treatment, the success of the therapy was put to the test. Previously the rats could cross a shiny ladder about two feet long in just 10 seconds. After their spinal cord was injured - and with their feet now splayed out in different directions - it took the animals twice as long to stumble across the ladder.
Nine weeks after the laser light treatment, the rats with the damaged spinal cords again set out to cross the ladder. They only took 10 seconds - a medical miracle.
Then came the footprint test. Before the experiment started, the rats had been marched with inky feet across a sheet of paper. Their prints were taken again after their spinal cord was cut into, showing how their feet, which normally point straight ahead, were at all angles. Nine weeks after treatment, the rats foot patterns was completely back to normal.
Prof Anders said they still do not fully understand how laser light cures the injury. "Our best guess is that light somehow alters the behaviour of the cells, inhibiting the immune system and allowing the neurons that make up the spinal cord to regrow."
Using coloured dyes, Dr Byrnes established that neurons were indeed making the return journey over the old break in the spinal cord.
Israel has long been a leader in laser therapy and this past summer Reeve flew there to see the progress Israeli scientists and doctors were making on spinal cord injuries. He had private meetings with the specialists and public visits to labs and hospitals.
One of the leading doctors, Dr Semion Rochkind, of Tel Aviv University, told Reeve that a cure for his paralysis could be as little as two years away.
Dr Rochkind believes a combination of laser and stem cell technology will work together to repair broken spinal cords.
Prof Anders admires the work done in Israel. "However, what they are planning is very complex and it involves invasive surgery. The beauty of what we are proposing is its very simplicity."
Prof Anders said she has faced massive cynicism over the years. Her immediate boss was among the sceptics. "Until I showed him the changes in the cells of the rats after our experiments. Now he is completely on our side." - (Edit International)