Want details on Elon Musk’s brain implant trial? You’ll have to ask him

(This story has been refiled to fix the reference to ‘unreasonable’ risk, in paragraph 11)

By Marisa Taylor

WASHINGTON (Reuters) – Elon Musk’s announcement this week that his startup Neuralink had implanted the first human patient with its experimental brain device generated immediate buzz.

But Musk’s statements on his social media platform X raised more questions than they answered about the trial for a risky device that the tech billionaire says could one day help the paralyzed walk, four experts in the brain implant field told Reuters.

Neuralink does not have to divulge even basic details about its trial, including the facility where patients are being implanted with the device and monitored, as well as the number of participants and expected completion date.

That is because the study was approved by the U.S. Food and Drug Administration as a “first in human” or “early feasibility” trial, the four experts said, based on Neuralink’s characterizations.

Unlike a standard clinical trial, such studies allow companies to develop a product concept, but are not designed to prove safety or efficacy, the experts said. Early feasibility studies like Neuralink’s are exempt from a requirement to post trial details on the U.S. National Institutes of Health’s website, ClinicalTrials.gov.

That gives Musk more control over what is known about Neuralink’s progress. The experts contacted by Reuters said that is concerning, given Musk’s track record of public hyperbole regarding his businesses, from electric vehicle maker Tesla to rocket-builder SpaceX.

“Elon Musk is not about transparency,” said Kip Ludwig, former program director for neural engineering at NIH. “He’s about doling out pieces of information, often in a misleading fashion.”

Neuralink did not respond to Reuters’ questions. An FDA spokesperson said any clinical trial participants must be provided with information on the risks, potential benefits and alternatives to a specific study and give informed consent to the testing.

“The FDA will continue to monitor the safety of those enrolled in the study for Neuralink’s implant device through required, regular reports,” the spokesperson said.

In 2022, the FDA reported approving around 40 early feasibility studies.

The FDA is prohibited from disclosing details about such studies and generally has to rely on the company to disclose any problems to the public voluntarily, the experts said. If an adverse event is deemed to pose an “unreasonable” risk to patients, the FDA can halt a trial if the sponsor refuses to.


Given the sensitivity of implanting devices in the brain, some companies opt for transparency even if it is not required.

“They could give the public more confidence about their safeguards and protections for trial participants if they registered on the (NIH) site,” said Victor Krauthamer, a former FDA official whose work included reviewing human-trial requests for brain implants.

Synchron, which is further ahead than Neuralink in testing its brain device, listed its “early feasibility” study of six patients on the NIH website, where an estimated 4.5 million visitors seek information on hundreds of thousands of clinical research studies each month.

Major medical journals often require that a trial be registered on ClinicalTrials.gov to publish data from the research, experts said.

“We have published over 25 publications over 10 years,” Synchron’s CEO Tom Oxley told Reuters in an email. “We want to be a part of the clinical and scientific community.” Oxley confirmed that all six patients had been implanted with the company’s device.

Neuralink was launched in 2016 and received FDA approval for the human study in May 2023, several years after Musk initially predicted it would receive a green light.

Musk’s bullish remarks have helped propel his company’s valuation to about $5 billion, Reuters reported in June.

So far, Neuralink has said its trial is focused on a small number of patients with limited or no ability to use both hands due to cervical spinal cord injury or the degenerative disease known as amyotrophic lateral sclerosis (ALS).

The study will use a robot to surgically place its implant in a region of the brain that controls the intention to move, with an initial goal of enabling people to control a computer cursor or keyboard using only their thoughts.

Musk posted this week on X that Neuralink’s first patient was “recovering well” a day after the device was implanted. He also described what appeared to be a positive sign that the device was detecting neural activity as it should.

The activity is not necessarily evidence the device will work long term, the experts interviewed by Reuters said. Such signals can go quiet for weeks before returning due to the normal healing response to the implant.

“The question is what will their device be doing after six months or three years?” said Ludwig.

(Reporting by Marisa Taylor; Editing by Michele Gershberg and Daniel Wallis)