MAKING BRAINWAVES

Scientists used an experimental procedure to bring a man out of a 15-year vegetative state

The 35-year-old car crash survivor was still alive 15 years later—but completely paralyzed and unresponsive. He was in what scientists refer to as a ‘persistent vegetative state.’ After 12 months, most medical professionals consider this type of brain damage irreversible.

That was, until, scientists working in France performed an experimental procedure to tickle one of the largest nerves in the body. With a little electrical stimulation, the patient was able to regain the ability to move his eyes in response to people around him, and even slowly turn his head, according to a case study published in Current Biology on Sept. 25.

“This paper is a warning to all those believing that [a persistent vegetative] state is hopeless after a year,” Niels Birbaumer, a neuroscientist at the University of Tübingen, told the Guardian. Birbaumer is unaffiliated with the paper, and works on developing brain computer interfaces for patients who are locked-in. People with locked-in syndrome are fully conscious, but completely paralyzed.

The brain and other nerves normally communicate through electrical signals and rely on the vagus nerve, one of the largest nerves in the body. This nerve branches out to connect the most important organs to the brainstem and part of the brain called the thalamus, which is thought to help give us our consciousness. Researchers from the National Center for Scientific Research in France hypothesized that maybe, stimulating the vagus nerve would somehow reawaken brain activity and awaken consciousness. In a procedure that took about 20 minutes, a surgical team implanted a small device on the nerve in the man’s chest which device generated tiny amounts of electrical signals over the course of six months.

Brain scans showed that after a month, the man’s brain had started producing a type of wave, called a theta signal, that isn’t present in people in a vegetative state. He was also able to track objects with his eyes, and widen them with surprise or fear when a researcher came close to his face. He could slowly turn his head. Researchers concluded that the patient has regained minimal consciousness, although notably he didn’t improve any more after nine months.

It appeared that the electrical chatter between the vagus nerve and the thalamus had been silenced by the man’s car accident. Angela Sirigu, a cognitive neuroscientist and the leader of this project, told Science Magazine that she thought that maybe, giving the vagus nerve extra electrical signal was be enough of a boost for it to finally reach the brain.

One case study is not enough to greenlight this procedure for all patients in a long-term vegetative state. In the vast majority of these cases, the condition is permanent. However, this example suggests that there may be the possibility of partially bringing a person’s consciousness and motor control back with the help of electrical stimulation.

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