A fully implanted endovascular brain-computer interface (BCI) safely continued to help people with amyotrophic lateral sclerosis (ALS) communicate at 1 year, data from the SWITCH trial showed.
All four ALS patients who had the endovascular motor neuroprosthesis implanted met the study's primary safety endpoints at 12 months, reported Douglas Weber, PhD, a bioengineering professor at Carnegie Mellon University in Pittsburgh, at a press briefing for the 2022 American Academy of Neurology annual meeting.
As seen in an earlier , participants were able to independently complete tasks like text messaging, online shopping, and managing finances using the device.
This is the first endovascular BCI for people with severe paralysis, Weber noted.
A BCI is a device that measures and translates brain signals into computer commands. "These can be used for digital messaging, web browsing, and other actions that allow people with severe paralysis to reconnect with the world," Weber said.
"BCI technology holds a great potential to empower the more than 5 million people in the U.S. who are severely paralyzed to once again perform important activities of daily living," Weber added.
Typically, implanting a BCI device requires surgery to remove part of the skull and place electrodes on the brain. The trial tested a minimally invasive BCI that would reach the brain by vascular access without a craniotomy.
"This is an endovascular BCI, which means that it is delivered by a venous catheter using techniques that are common in neurointerventional procedures," Weber noted.
The BCI device was made of a net-like material with 16 sensors attached and was implanted with a catheter to guide placement in the superior sagittal sinus. It was connected to an electronic unit in the chest that relayed signals from the motor cortex into computer commands.
"The sensors are positioned on a stent-like scaffold that deploys against the walls of the superior sagittal sinus, which is a large blood vessel that runs adjacent to the medial edge of the primary motor cortex," Weber said. "This device senses the electrical activity that occurs in the motor cortex when someone thinks about moving their limbs."
"These movement signals are then transmitted to an external device, where they are decoded to form command signals that are sent to a computer, thus providing a direct communication link for the brain to express movement intention," he continued.
All four participants in the SWITCH study completed the 12-month follow-up with no serious adverse events. Postoperative imaging showed patent blood vessels in all participants and no device migration.
The device has the potential to be used in other patients, not just those with ALS, Weber noted. "We are starting with ALS, but our inclusion criteria include people who have severe paralysis, regardless of cause," he said. "So someone with a brain stem stroke, for example, or a very high-level spinal cord injury -- these are all people who may benefit from the digital communication functions supported by this technology."
Device maker Synchron is continuing its research in the U.S. and Australia and secured FDA its commercial BCI in humans ahead of other companies, including Elon Musk's Neuralink. Its upcoming COMMAND study of six severely paralyzed patients will be by the NIH.
Disclosures
The study was supported by Synchron Inc., the maker of the device, the U.S. Defense Advanced Research Projects Agency, the Office of Naval Research, the National Health and Medical Research Council of Australia, the Australian Federal Government Foundation, and the Motor Neurone Disease Research Institute of Australia.
Primary Source
American Academy of Neurology
Campbell B, et al "Long-term safety of a fully implanted endovascular brain-computer interface for severe paralysis: results of SWITCH, a first-in-human study" AAN 2022.