Prosthesis Developed to Treat Brain Injury

Researchers have developed a prosthesis for the brain which shows promise in treating rats with brain injury, reporting that their work could lead to the creation of a functional neural prosthesis to be used in humans.

The device is a closed-loop microelectronic system which can record signals from one area of the brain, process them in real time, and then bridge the brain injury by stimulating a second part of the brain that has lost connectivity.

Implanted in laboratory rats with brain trauma that caused them to lose function of their forelimbs, the device enabled them to reach through a narrow opening and grasp food.

If the device, or one similar to it, is one day developed for humans, it could be used to treat brain injuries in a variety of cases including stroke victims or soldiers with traumatic brain trauma, the researchers said. 

Scientists from Case Western Reserve University and University of Kansas Medical Center published their research in the journal Proceedings of the National Academy of Sciences.

"If you use the device to couple activity from one part of the brain to another, is it possible to induce recovery from traumatic brain injury? That's the core of this investigation," said Pedram Mohseni, a professor of electrical engineering and computer science at Case Western Reserve, who built the brain prosthesis.

"We found that, yes, it is possible to use a closed-loop neural prosthesis to facilitate repair of a brain injury," he said.

To test the concept, researchers took lab rats and disabled the parts of their brain that control forelimb movement.

The coin-sized prosthetic device works by amplifying signals called neural action potentials, which are produced by neurons in the anterior, or front, of the brain.

An algorithm separates these signals, which are recorded as brain activity spikes, from other brain activity. When the spikes are detected, the prosthesis sends a pulse of electric current to stimulate neurons in the posterior (rear) part of the brain, creating an artificial connection between the two regions.

After two weeks of using the prosthesis, the rats have nearly recovered all function of their forelimbs that was lost when their brains were injured, retrieving the food pellets from the narrow opening as successfully as rats without brain trauma.

"A question still to be answered is must the implant be left in place for life?" Mohseni said. "Or can it be removed after two months or six months, if and when new connections have been formed in the brain?"

The researchers plan to continue their research to determine what happens in the brain to lead to a restoration of function. They also want to investigate whether there is an optimal time window after injury in which they must implant the prosthetic device to restore function.