WEDNESDAY, March 30, 2022 (HealthDay News) — A handful of “locked down” amyotrophic lateral sclerosis (ALS) patients can now use a laptop using their brainwaves, thanks to an implant housed in a major vein inside of their skull.

The implant – a stent lined with 16 tiny electrodes – is nestled in a vein near the motor cortex of completely paralyzed patients, the authors of a new study on the procedure have explained.

“This device detects the electrical activity that occurs in the motor cortex when someone thinks about moving their limbs,” co-investigator Douglas Weber, professor of mechanical engineering and neuroscience at Carnegie Mellon University, told Pittsburgh. “These motion signals are then transmitted to an external device where they are decoded from command signals which are sent to a computer, providing a direct communication link for the brain.”

With the implant, patients can send emails and texts, browse the web, shop online or manage their personal finances, Weber noted.

“Many activities of daily living seem to be well supported by this device,” he said.

This isn’t the first research effort to use brain implants to help paralyzed people use computers or other electronic devices.

For example, a study published last week detailed the case of a locked-up German ALS patient who regained the ability to communicate via two microchips implanted in his brain. This article was published in the journal Nature Communication.

But this is the first attempt to place such an implant without removing part of the skull to access the brain, the researchers said.

Four patients with the neurodegenerative disease called ALS — also known as Lou Gehrig’s disease — instead received their implant through a catheter threaded into one of the main veins that drain blood from the brain, Weber said.

The catheter delivers the implant into a part of the vein near the brain. The implant then opens and lines the walls of the vein, much like a normal stent expands to support the walls of a narrow or weak blood vessel in heart attack patients.

Once in place, the implant picks up signals from the motor cortex and relays them to an electronic decoder implanted in the person’s chest, Weber said.

The decoder analyzes the nerve signals when people think about certain movements – for example, tapping their feet or extending the knee – and translates those thoughts into computer navigation.

In combination with eye-tracking technology, these motion thoughts enabled patients to use a laptop computer, Weber said. One of the patients became so gifted that he could control a computer independently, without an ophthalmologist.

Preliminary results were presented Tuesday, ahead of the annual meeting of the American Academy of Neurology (AAN), which will be held April 2-7 in Seattle. Such research is considered preliminary until it is published in a peer-reviewed journal.

Dr. Natalia Rost, chair of the AAN’s scientific committee, praised the “cross-pollination” of neuroscience and engineering in the study, noting that such efforts “sometimes yield some of the most exciting results.”

The purpose of this small-scale study was primarily to show that the implant posed no risk to patient safety.

“Obviously, as a stroke physician, I’m very committed to the safety of these devices,” said Rost, who is chief of the stroke division at Massachusetts General Hospital in Boston. “There’s a certain fear of God that you instill in stroke doctors by inserting a device” into a major cranial vein.

In the new study, researchers followed participants for a year, finding that the device stayed in place for all four patients and did not impede blood flow.

“The device embeds well into the walls of the blood vessel over time,” Weber said. “Certainly after implantation the device is exposed to the bloodstream, but once it is encapsulated and fully embedded in the blood vessel wall, I think the risks of thrombosis [clotting] decrease over time.

Since there were no signs of clots or vein blockages in the initial patients, the research team continued to enroll more people in a larger trial for the implant, Weber said.

Investigators plan to expand the trial to include patients who are severely paralyzed for reasons other than ALS, Weber said, potentially including victims of severe strokes or people with spinal cord injury. .

“These are all people who can benefit from the assisted communication and digital communication features supported by this technology,” Weber said.

More information

The US National Institutes of Health has more to say about ALS.

SOURCES: Douglas Weber, PhD, professor, mechanical engineering and neuroscience, Carnegie Mellon University, Pittsburgh, Pennsylvania; Natalia Rost, MD, division chief of stroke, Massachusetts General Hospital; presentation, March 29, 2022, American Academy of Neurology Annual Meeting, Seattle