Brain Implants Show Promise for People With Traumatic Brain Injuries in Small Study

Electrodes placed in the brains of five patients led to “profound” improvements in cognitive function, even years after their injuries

An illustration of a person's brain
Illustration of the thalamus, a region of the brain linked to learning and memory. Sebastian Kaulitzki / Science Photo Library via Getty Images

Traumatic brain injuries, or TBIs, are a major cause of death and disability in the United States. About 2.5 million people sustain a TBI annually, often through falls, car accidents or sports injuries, per a 2015 report from the Centers for Disease Control and Prevention. While patients with mild brain injuries may eventually return to normal, severe injuries can cause permanent cognitive impairments or personality changes—and about five million Americans currently live with a disability related to a TBI.

“One of the major problems is that there really are no effective therapies for traumatic brain injury,” Jaimie Henderson, a neurosurgeon at Stanford University, tells New Scientist’s Chen Ly. 

But now, in a small trial, researchers have discovered that surgical brain implants may be an effective way to restore cognitive function in patients with TBIs. They published their results Monday in the journal Nature Medicine.

To test the implants, the research team recruited six participants who had sustained moderate to severe traumatic brain injuries between three and 18 years ago and ran cognitive tests to measure their ability to focus and switch tasks. Then, they surgically implanted an electrode that could stimulate a region of the brain called the central lateral nucleus, located in the thalamus, a region linked to learning and memory. After a traumatic injury, cells in this region may have died or been disconnected, so the researchers thought that an electrical device might restore some of these lost connections, as lead author Nicholas Schiff, a neurologist at Weill Cornell Medical College, tells Darren Incorvaia of Science News

“You can think of it almost like a pacemaker,” Henderson, who is a co-author of the study, tells New Scientist. “The device is implanted in the brain and delivers electrical pulses to electrodes that are placed on specific parts of the brain.”

One participant withdrew from the study because of a scalp infection, but the remaining five underwent a series of tests starting one month after the surgery. In all, the subjects showed improvements between 15 to 52 percent on a test that measures executive function, exceeding the 10 percent benchmark, the researchers report.

“What this study shows is that they potentially can make a difference years out from injury,” Deborah Little, a psychologist at the University of Texas Health Center at Houston who was not involved in the study, tells NPR’s Jon Hamilton. “Even a 10 percent change in function can make the difference between being able to return to your job or not.”

After the study, the researchers also conducted interviews with the participants and their families. In these interviews, many reported robust changes. Following their injuries, some of the volunteers had difficulty with concentration and focus, but after the implant, they were able to engage in activities they used to enjoy, such as playing complex multi-player games or reading.

“I got my daughter back. It’s a miracle. It’s so profound for us,” the mother of one of the participants said in an interview. “She’s reemerged. The maturity she’s showing—she can stop and think before she acts… It’s changed everything.” 

Participant Gina Arata was forced to abandon plans to go to law school after a car crash at age 22 left her with fatigue, memory problems and difficulty controlling her emotions, reports Carl Zimmer for the New York Times. Eighteen years later, Arata received the implant and reports to the publication that it changed her life. 

“I can be a normal human being and have a conversation,” she tells the Times. “It’s kind of amazing how I’ve seen myself improve.”

Next, the researchers plan to expand their study to more patients so they can further test the safety and efficacy of the implants, per Science News.

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