The men who had been paraplegic for many years were able to walk over ground after undergoing five months of intensive rehabilitation involving extremely precise electrical stimulation of the lumbar spinal cord and weight-assisted therapy.
“This is, I believe, the first time that people who have been paralysed for several years are now able to walk voluntarily over ground even outside the laboratory environment,” said study co-author Grégoire Courtine, a neuroscientist at Switzerland’s EFPL technology institute.
Crucially, in the study’s second key finding, the three patients could even control their previously paralysed leg muscles without electrical stimulation.
Previously, in studies using constant electrical stimulation a small number of paraplegic patients have been able to walk a few steps, but only when that electrical stimulation was activated.
The result of the study, which was led by the EFPL and the Lausanne University Hospital (CHUV) have just been published in the journals Nature and Nature Neuroscience.
The research “establishes a new therapeutic framework to improve recovery from spinal cord injury”, according to a statement put out by EPFL on Wednesday.
“Our findings are based on a deep understanding of the underlying mechanisms which we gained through years of research on animal models. We were thus able to mimic in real time how the brain naturally activates the spinal cord,” says EPFL neuroscientist Grégoire Courtine of the study known as STIMO (STImulation Movement Overground).
“The exact timing and location of the electrical stimulation are crucial to a patient’s ability to produce an intended movement. It is also this spatiotemporal coincidence that triggers the growth of new nerve connections,” Courtine added.
For the patients, a large part of the difficulty involved learning how to coordinate the desire of their brains to walk with the targeted electrical stimulation, according to the EFPL media release. But after a week, the three paraplegic men could walk with body-weight support.
Sebastian Tobler, Gert-Jan Oskam, Grégoire Courtine and David Mzee. Photo: EPFL / Hillary Sanctuary.
“One of the key moments is when I started walking hands-free on the treadmill. Really letting the bars going and doing one, two, three steps was really crazy because I just couldn’t do it before and it wouldn’t work without stimulation,” said 30-year-old who has been paralysed since 2010.
While it remains early days, Courtine and fellow researcher Jocelyne Bloch now plan to use the findings to help develop neurotechnology aimed at making the therapy widely available.
“The next step is to start earlier, just after the injury, when the potential of the injury is much larger,” said Bloch.
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