For the first time, an implant that beams instructions out of the brain has
been used to restore movement in paralysed primates, say scientists.
The team at the Swiss Federal Institute of
Technology bypassed the injury by sending the instructions straight from the
brain to the nerves controlling leg movement in Rhesus monkeys. Spinal-cord injuries block the flow of
electrical signals from the brain to the rest of the body resulting in
‘The implanted chip reads the spikes of electrical activity that are the instructions for moving the legs and send them to a nearby computer which sends instructions to an implant in the spine to electrically stimulate the appropriate nerves.’
It is a wound that rarely heals, but one potential solution is to use
technology to bypass the injury. In the study, a chip was implanted into the
part of the monkeys' brain that controls movement.
The chip read the spikes of electrical
activity that are the instructions for moving the legs and send them to a
nearby computer. It deciphered the messages and sent
instructions to an implant in the monkey's spine to electrically stimulate the
appropriate nerves. The results published in the journal Nature
the monkeys regained some control of their paralysed leg within six days and
could walk in a straight line on a treadmill.
Dr Gregoire Courtine, one of the
researchers, said: "This is the first time that a neurotechnology has restored
locomotion in primates. The movement was close to normal for the basic walking
pattern, but so far we have not been able to test the ability to steer."
The technology used to stimulate the spinal
cord is the same as that used in deep brain stimulation to treat Parkinson's
disease, so it would not be a technological leap to doing the same tests in
"But the way we walk is different to
primates, we are bipedal and this requires more sophisticated ways to stimulate
the muscle," said Dr Courtine.
Jocelyne Bloch, a neurosurgeon from the
Lausanne University Hospital, said: "The link between decoding of the brain
and the stimulation of the spinal cord is completely new. "For the first time, I can image a
completely paralysed patient being able to move their legs through this
Dr Mark Bacon, the
director of research at the charity Spinal Research, said: "This is quite
impressive work. Paralysed patients want to be able to regain real control,
that is voluntary control of lost functions, like walking, and the use of
implantable devices may be one way of achieving this."