There may be an answer for people suffering from traumatic brain injuries. It's a device called a brain-machine-brain interface — and it has the potential to revolutionize the way brain damage is treated in humans.
As it stands, there is no effective way to treat damage and improve function after someone experiences a traumatic brain injury (TBI). This is a problem for the 1.5 million Americans who suffer from TBI and the 800,000 stroke victims who suffer weakness or paralysis in the U.S. annually.
Closing the Gap
But now, a team of neuroscientists from Case Western Reserve University and the University of Kansas Medical Center have devised a solution that appears to work in rats. It's an implantable prosthesis called a brain-machine-brain interface that serves as a closed-loop microelectronic system. The device works by recording signals from one part of the brain, processing them in real time, and then linking the injury by stimulating a second part of the brain that has lost connectivity. Essentially, the prosthetic works by bridging the gaps caused by brain injuries, which in turn facilitates repair.
For the experiment, the researchers mimicked TBI in rats by literally cutting the communications link between the motor and sensory areas required for limb movements. After performing this procedure, the rats were unable to use their forelimbs and grasp for food.
To fix this mess, the brain-machine-brain interface — a microchip on a circuit board smaller than a quarter — was connected to microelectrodes implanted in two regions, the anterior and posterior parts of the rats' brain. The neural action potentials were amplified and processed by an algorithm, which were recorded as brain spike activity. As each spike was detected, the microchip sent a pulse of electric current to stimulate neurons in the brain, thus artificially re-connecting the two brain regions.
The researchers left this running continuously for two weeks, after which time the rats recovered nearly all function lost due to injury. In subsequent tests, rats were able to retrieve a food pellet nearly 70% of the time, which was just as good as uninjured rats. Rats that received random brain stimuli from the device achieved 50% success (which is interesting unto itself), while those that received no treatment retrieved about 25% of the pellets.
The next question the researchers hope to answer is whether or not the implant needs to be left in place for life. It's hoped that, for future human applications, the device can be removed after sufficient brain connections have been restored.
Read the entire study at PNAS: "Restoration of Function After Brain Damage Using a Neural Prosthesis".