An international team of scientists announced this Wednesday “a new era” in the treatment of neurological diseases. Researchers have installed “a digital bridge” between the brain and spinal cord of Gert-Jan Oskam, a 40-year-old Dutchman who became a quadriplegic after a bicycle accident in 2011, when he was returning from work. Two implants in his brain now read his thoughts and send them, wirelessly, to a third implant that electrically stimulates his spinal cord. The patient is able to walk long distances on crutches and even climb stairs. Oskam had previously tested a more rudimentary device in another clinical trial, but on Tuesday he enthusiastically proclaimed the difference at a press conference: “Before, electrical stimulation controlled me. Now I am the one who controls the stimulation”.
The bicycle accident caused an incomplete spinal cord injury, which allowed Oskam some residual movement. Thanks to years of hard rehabilitation, the Dutchman managed to regain a lot of mobility in his arms. In 2014, the ray of hope arrived: a new scientific technique, with electrical stimulation in the spinal cord through an implant, was successful in rats in an experiment at the Swiss Federal Institute of Technology in Lausanne. Those rodents, with their marrow cut in two, could take more than a thousand steps. In 2016, the strategy also worked in monkeys.
Oskam was one of the first humans to test that experimental device in 2017, which emitted electrical pulses in his spinal cord, synchronizing them with his clumsy voluntary movements. The patient himself could also manually control, with a few buttons, the stimulation of his legs. The new technology goes much further, according to the Spanish neuroengineer Eduardo Martín Moraud, who participated in the animal experiments. “This study is a giant step towards the dream of restoring voluntary motor control in patients suffering from neurological diseases, such as spinal cord injury, stroke, Parkinson’s and essential tremor”, he celebrates.
Colombian neuroengineer Andrea Gálvez, born in Bogotá 32 years ago, has been one of the main authors of the new study. “Gert-Jan already had an implant in her spinal cord, which allows electrical stimulation and reactivates her leg muscles. In this clinical trial, we have placed two implants in the motor part of the brain, one in each hemisphere, which allow us to read the intention of movement, decode it, and make that digital bridge so that the stimulation in the legs is deliberate,” says Gálvez. The results of it are published this Wednesday in the journal Nature, the spearhead of the best world science.
Neuroengineer Andrea Gálvez, from the Federal Polytechnic School of Lausanne, in Switzerland.EPFL
The leaders of the research are the neuroscientist Grégoire Courtine and the neurosurgeon Jocelyne Bloch, from the Federal Polytechnic School of Lausanne. His team has spent more than a decade perfecting the device with adaptive artificial intelligence. Courtine acknowledged at the press conference that “this technology is still in its infancy” and announced that the next step is to miniaturize the devices and test them on more patients. So far only Gert-Jan Oskam has tested them. The system requires replacing about two square inches of skull with a titanium-containing material and carrying a small backpack with a processing unit. Bloch does not hide her enthusiasm: “To myself, at first, it seemed like science fiction. And now it’s a reality.” The company Onward, founded by Courtine and Bloch, is trying to develop a commercial version of this digital bridge.
The neurologist Antonio Oliviero, from the National Hospital for Paraplegics, in Toledo, applauds the new work, but with caution. “It is an important step, but at the moment he is only a patient. We do not know to what extent it is generalizable ”, he underlines. Oliviero points out that Oskam has a small clinical improvement even when the system is turned off, which suggests a reorganization of his neural circuits. “It can be a rehabilitation tool,” he says.
Neuroscientist Grégoire Courtine, patient Gert-Jan Oskam and neurosurgeon Jocelyne Bloch, at a press conference.
Digital bridges are not the only promising alternative for people with spinal cord injuries. Oliviero gives some examples. The Puerta de Hierro public hospital in Madrid is testing a treatment with the patient’s own stem cells, injected into the exact place of his injury. At the Chicago Rehabilitation Institute, Chilean Mónica Pérez experiments with non-invasive electrical stimulation at multiple points, with encouraging results. And Antonio Oliviero’s own group is testing the drug rimonabant, which favors the excitability of motor neurons.
Martín Moraud, a 39-year-old neuroengineer from Madrid who runs his own laboratory at the Lausanne University Hospital, believes that the level of precision achieved by his colleagues Courtine and Bloch is unprecedented. “It’s something that has been dreamed of for decades,” he says. Martín Moraud now tries to transfer the idea of the digital bridge to Parkinson’s disease. “The concept is similar: having neural measures of motor intent—or of motor deficits—that can be used to stimulate the spinal cord,” he says.
The Swiss institutions involved have distributed an emotional video of Gert-Jan Oskam, in which he is seen leaning on a bar with a beer and some fries, talking to two other people. “I’ve spent over 10 years without being able to stand up having a beer with friends. These are things that people don’t normally value,” proclaims Oskam.
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