For the first time, a brain implant is being tested in conjunction with an implant that stimulates the spinal cord to give a paraplegic patient the opportunity to mentally move his arms, hands and fingers again, the Dutch company Onward announced on Wednesday.
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The combination of these two technologies had already enabled a paraplegic patient to regain natural control of walking through thought, an advance that was the subject of a publication in the journal Nature in May.
However, this is the first time this double technique has been used for the upper limbs.
“The mobility of the arm is more complex,” surgeon Jocelyne Bloch, who performed the implantation operations, told AFP.
Even compared to walking, there are no balance problems here, “the muscles in the hand are quite good, with many different small muscles that are activated at the same time during certain movements,” she says.
The patient, who wishes to remain anonymous, is a 46-year-old Swiss man who lost the use of his arms after a fall. Two surgeries took place last month at the Center Hospitalier Universitaire Vaudois (CHUV) in Lausanne, Switzerland.
The first to place the brain implant developed by the French organization CEA-Clinatech, a few centimeters in diameter, over the brain instead of a small piece of skull bone.
The second is to place the electrodes developed by Onward at the level of the cervical spine and connect them to a small box that is implanted in the abdomen.
The brain implant (or brain-machine interface, BMI) senses the brain regions that are activated when the patient thinks about a movement and transmits them to the electrodes. A kind of “digital bridge”.
“Things are going well so far,” said Jocelyne Bloch, co-founder of Onward and an advisor to the company. “We can record brain activity and know that the stimulation is working. (…) But it is still too early to talk about what progress he has made and what he is capable of now.
Results expected later
The patient is in the training phase to ensure that the brain implant recognizes the different desired movements. The lost movements then have to be repeated many times before they can become natural. The process will take “a few months,” said Dr. Bloch.
Two additional patients are scheduled to take part in this study. Full results will be published later.
Spinal cord stimulation has been used in the past to successfully move the arm of paralyzed patients, but without coupling with a brain implant.
And brain implants have already been used to allow a patient to control an exoskeleton.
The Battelle organization used a brain implant to restore movement in a patient’s arm – but it was equipped with an electrode sleeve attached to the forearm that directly stimulated the affected muscles.
“Onward is unique in its desire to restore movement through spinal cord stimulation” coupled with a brain implant, its boss Dave Marver told AFP.
According to him, this technology could be commercialized “by the end of the decade.”
The brain implant space is booming, with companies like Synchron and Neuralink in the niche. In particular, they are working on enabling paralyzed patients to control computers through their minds and, for example, giving them back the ability to write.