Latest studies reveal that control over paralyzed limbs can be restored. Spin cord injuries are life-altering, making it difficult to diagnose or reverse the injuries. Recently, the improved understanding in neurobiology has raised hopes that people can gain some control over their paralyzed limbs.
Recently, researchers have designed a spinal implant that can control the leg muscles of paralyzed individuals, allow them to walk with assistance within hours of the implant being activated.
Functioning of the Breakthrough Spinal Implant
According to a new study published in the journal Nature Medicine, the electrodes deliver electrical pulses to specific regions of the spinal cord, activating muscles in the trunk and legs. The soft and flexible device lies directly on top of the spinal nerves, under the vertebrae, and can be controlled wirelessly with software, operated from a tablet, and a handheld clicker.
The software communicates with a pacemaker-like device in the abdomen, which further directs the activity of the nerve-bound electrodes on the spinal cord. With the tap of a touch screen, the user of the implant can prompt their device to generate a precise pattern of stimulation. These stimulation patterns translate to patterns of muscle activity, allowing the user to walk, cycle, or swim, for instance. Users can also manually switch between these stimulation patterns with their clicker.
Procedure of the Experiment
Co-senior author of the study, Grégoire Courtine, a neuroscientist and professor at the Swiss Federal Institute of Technology Lausanne (EPFL), said: “All three patients were able to stand, walk, pedal, swim and control their torso movements in just one day, after their implants were activated.”
After the initial implantation, the patients underwent extensive training to get used to using the device and regain muscle mass and motor control. Eventually, the patients progressed from using the implants only in a controlled lab setting to using them out and about in their daily lives.
Mechanism of the Technology
The new device builds on existing technology called spinal cord stimulators, which are already used to alleviate pain. The study team modified these stimulators to target specific nerves involved in controlling muscles of the legs and lower trunk, they wrote in their report. In addition, during the trial, the team custom-fit each implant to match the length of the spinal cord and the position of the nerves in different participants, according to STAT.
According to STAT, the device will now be tested in a large-scale trial in the U.S. and Europe. The team hopes to test the device in people with relatively recent injuries; in the three-person trial, all of the participants were at least a year out from their injuries. It is also investigating whether a similar stimulator could be implanted directly into the motor cortex, a key region of the brain for controlling voluntary movement. Such a device could allow people with paralysis to direct their movements without the aid of a tablet or clicker.