Implant by Elon Musk's Neuralink suffers setback after threads retract from patient's brain

Elon Musk’s brain technology startup Neuralink said Wednesday that an issue cropped up with the company’s first human brain implant weeks after it was inserted into a patient.

The company revealed in a blog post that in the weeks following the patient’s surgery in January, a number of the implant’s connective threads retracted from the brain, causing a reduction in the signals that could be captured by the device.

Neuralink provided few other details about the problem and did not disclose what may have caused the threads to retract.

The company did say, however, that it modified an algorithm “to be more sensitive to neural population signals,” meaning it was able to improve how the patient’s brain signals were detected and translated.

Neuralink’s first human patient, 29-year-old Noland Arbaugh, lost all movement and sensation in his arms and legs after a diving accident in 2016.

Neuralink’s N1 device is about the size of a quarter and is designed to be fully implanted on the skull. The device is connected to the brain’s motor cortex through 64 ultra-thin threads with tiny electrodes that pick up neural signals from the patient.

It’s not known if the retracted threads posed any safety concerns for Arbaugh at the time.

In March, the company hosted a livestream during which Arbaugh moved a cursor across a laptop screen and played online chess using only his thoughts. In other videos released by the company, Arbaugh appeared to play the racing video game Mario Kart with the brain chip.

The latest update comes less than a week after Neuralink’s cofounder, Dr. Benjamin Rapoport, suggested in a May 3 episode of the Wall Street Journal’s “The Future of Everything” podcast that he left the company due to safety concerns.

Rapoport, a neurosurgeon, cofounded Neuralink with Musk and other scientists in 2016, but later left to start a new company called Precision Neuroscience.

“I’ve pretty much devoted my entire professional life to bringing neural interfaces from the world of science to the world of medicine. But I’ve felt that in order to move to the world of medicine and technology, safety is paramount,” he said on the podcast.

It was not the first time the company faced controversy. Activist groups and internal staff complaints have alleged that Neuralink mistreated some of the animals used in experiments. A federal investigation did not turn up evidence of any violations beyond an “adverse surgical event” in 2019 that the company reported itself, according to Reuters.

Neuralink won approval last year from the Food and Drug Administration to conduct its first human clinical study. The company has been developing a brain implant that would allow people, including patients with severe paralysis, to control a computer, phone or other external device using their thoughts.

This article was originally published on NBCNews.com