Patients long paralysed from spinal cord injuries showed unprecedented gains in mobility and feeling – and in some cases a renewed sex life through virtual-reality training and the use of brain-controlled robotics, scientists said.
Six men and two women who had completely lost the use of their lower limbs all made significant progress, the researchers reported in the peer-reviewed journal Scientific Reports.
In four cases, doctors were able to upgrade their status to "partial paralysis", an unheard-of level of improvement using non-invasive techniques.
One of them a 32-year-old woman, paralysed for more than a decade, may have experienced the most dramatic transformation.
Read: Spinal cord injury: First aid
At the outset of the trial, undertaken at a clinic in Sao Paulo, Brazil, she was unable to stand, even with the help of braces.
Within 13 months, she could walk with the help of braces and a therapist, and could produce a walking motion while suspended from a harness.
Enhanced quality of life
"We couldn't have predicted this surprising clinical outcome when we began the project," said Miguel Nicolelis, a neuroscientist at Duke University in North Carolina and the main architect of the rehabilitative research.
"Until now, nobody has seen recovery of these functions in a patient so many years after being diagnosed with complete paralysis," he told journalists in a phone briefing.
Read: Stepping out of a wheelchair in a bionic walking suit
One of the women sufficiently recovered sensation on her skin and inside her body "that she decided to deliver a baby," Nicolelis said. "She could feel the contractions."
The progress translated into an enhanced quality of life according to the patients themselves, he added.
The innovative therapy combined several techniques to stimulate parts of the brain that once controlled the patients' long-inactive limbs.
The underlying – but still unproven – theory is that this process provokes changes not only in the brain, but in the damaged spinal cord as well.
Nicolelis took the global spotlight in June 2014 when a paraplegic wearing a robotic bodysuit he co-designed delivered the symbolic first kick at football's World Cup in Brazil.
What is back pain?
Causes of back pain
Risk factors for back pain