Bernat points out that every vegetative state case is different, and the vagus nerve stimulation might not work for every patient.
A person who is in a vegetative state does not show any evidence of con consciousness, mental function or motor function. The vagus nerve serves many roles in the anatomy: it controls the slowing of the heartbeat and the muscles of the small intestine.
As the BBC writes, within a month a man could respond to simple commands, turn his head and follow an object with his eyes.
The study was led by Dr. Angela Sirigu of the Institut des Sciences Cognitives - Marc Jeannerod in Lyon, France, who, along with a team of researchers, discovered that the key to waking the man up lied in the vagus nerve.
It's generally believed that patients who are in a vegetative state more than a year after experiencing severe brain trauma won't regain consciousness ever again. "I'm really glad to hear that the patient responded positively to vagus nerve stimulation treatment after 15 years in a vegetative state, but it's only one case". It's the longest nerve in the body's autonomous nervous system, which mostly regulates unconscious functions like heart rate, digestion, and breathing.
The 35-year-old was in a state of "unresponsive wakefulness" and although he was capable of some involuntary movements, he had no awareness or self or his environment, and this had not improved over time.
"Our study demonstrates the therapeutic potential of vagus nerve stimulation to modulate large-scale human brain activity and alleviate disorders of consciousness", said the authors. Brain scans also show heightened activity in the various areas of the cortex following stimulation.
By stimulating a nerve that stretches from the abdomen to the brain, French researchers have restored a significant measure of consciousness to a brain-damaged 35-year-old vehicle accident victim who had spent 15 years in a vegetative state. It also runs down both sides of the neck from the brain stem, across the chest and into the abdomen. This study shows that "it is possible to improve a patient's presence in the world", Sirigu said in a press release. "... A brain rhythm previously shown to distinguish vegetative from minimally conscious state patients, significantly increased", particularly in areas important for "movement, body sensations and awareness". His mother said he was more able to stay awake when his therapist read to him.
"Before any stimulation, the patient scored 6/23 and at the end of the study, when the patient was on the maximum stimulation, he scored 8/23 on the functional scale", she said.
Doctors at a Canadian intensive care unit discovered that one person had persistent brain activity after they turned off their life support machine, but three others did not.
According to the publication, in Current Biology, the tomographies confirmed this improvement.
"Brain plasticity and brain fix are still possible even when hope seems to have vanished", Sirigu said in a statement to the press.
Still, Hae said, if the French research team can replicate their outcomes in a larger study, the implications would be profound.