By Gill Higgins
BBC health correspondent
Justin Richardson was an American student passionate about sport.
Justin Richardson has regained feeling throughout his body
But one night, a reckless dive into a shallow pool broke his neck.
He was paralysed from the chest down and faced a life with no sensation at all in his lower limbs.
But an experimental treatment appears to have made a difference.
Justin says: "I can now feel most every single spot of my body.
"And I have my bladder control back now. I know when I need to use the rest room, which has improved my independence."
Spontaneous recovery can occur. But Justin believes it is the treatment which has helped him.
His medical team have been impressed.
Therapist Rebecca Czarnecki, Spinal Cord Fitness Coordinator at the WakeMed Rehab Centre in North Carolina says: "Justin compared to other patients with a similar injury is above and beyond their ability."
The treatment, called Procord, uses a type of white blood cell, called a macrophage, which is taken from the patient themselves.
When an injury occurs in most parts of the body, such as a wound to the hand, the immune system activates a healing processes, in which macrophages play a part.
This does not happen in the central nervous system, including the spinal cord, which is protected by the blood-brain barrier, a defence system blocking foreign substances in the body from reaching the nervous tissue.
Because the CNS has this extra protection, it should in theory not need the standard immune system mechanism, and so has a naturally low level of macrophages.
The Procord treatment aims to boost macrophage levels in the CNS, hopefully allowing nerves to work again.
In the treatment, macrophages are isolated from the patient's blood, activated using a process developed by the company, then injected directly into the spine.
In the first trial, eight patients were treated. No safety problems were reported, and three patients recovered some movement.
Some patients are receiving newly developed treatments
It is now being tested on dozens more patients in the US, Israel and Europe.
And with rapid advances in science, other treatments are also ready to be tested in humans.
In a study funded by Action Medical Research, Dr James Fawcett, of the Brain Repair Centre at the University of Cambridge, is investigating how to break down scar tissue around an injury.
The team have found that a bacterial enzyme called chonroitinase can digest the molecules within scar tissue to allow some nerve fibres to regrow.
Dr Fawcett is optimistic now a number of treatments, including his own, are ready for clinical trials.
But he thinks the future is all about using treatments together.
"We think the ultimate answer for spinal cord injury is a combination of treatments, all affecting different aspects.
"So what seeing now is first treatments coming out of science labs that are actually going to cause repair of the brain rather than ameliorating the effects of the injuries."
UK care needed
For decades, doctors have worked on preventing infection, improving symptoms, but a cure has remained out of reach.
There has been a focus on rehabilitation, adapting lives to cope with injury, rather than offering a chance of recovery
And while there's no wild excitement about an imminent cure, there's a sense of optimism.
So much so, one specialist is seeking approval for British patients to take part in carefully controlled trials here.
David Allen, a consultant at the Queen Elizabeth National Spinal Injuries Unit in Glasgow, said: "Most people with spinal cord injury are desperate. They're going to try anything and, historically, they've always travelled to try to find a cure.
"What we need to do now is to provide within the UK facilities to offer them any treatment which is showing promise of an opportunity to improve their condition."
Justin is doing better than he'd ever expected.
It could be he is one of the first patients to experience a partial cure.
But it is going to take years testing more patients to confirm whether a severed spinal cord can be repaired.