The victim of a terrible car crash, lying comatose for 15 years, has showed signs of regaining consciousness after having a nerve stimulator implanted into his chest and connected to his vagus nerve. Using the experimental technique, neurosurgeons in Lyon, France were able to mark signs of movement, attention and increased brain activity in the patient, who had been diagnosed as being in a vegetative state four weeks after his accident in 2002.
The doctors' nerve stimulator, implanted into the man's chest, worked to stimulate the man's vagus nerve, a series of fibers extending from behind the ears through the chest and to the stomach, sending the information received back to the brain. The nerve is important in waking, alertness and various other functions.
After only a month of use, researchers were able to mark signs of consciousness. The patient was able to respond to simple commands, follow an object with his eyes, and turn his head when asked. His mother said he could stay awake when his therapist read to him.
Just as importantly, researchers found improvement in the patient's brain activity, based on an EEG signal used to determine rudimentary consciousness. The signal increased in areas of the brain devoted to things like awareness, movement and sensation. Metabolic activity and brain connectivity also rose.
"By stimulating the vagus nerve, we've managed to show that we can improve the patient's presence in the world even when it seems that everything is lost. The brain retains the ability to form new connections and repair itself even in such a critical situation," the researcher added.
Scientists are now preparing to conduct new clinical trials using a large number of volunteers, which Sirigu and her colleagues hope will confirm their findings and help doctors understand what needs to be done to further improve the condition of patients in a comatose state.