Nerve stimulation 'raised awareness' of man in vegetative state

Miami : Researchers said Monday that a nerve stimulation technique may have raised the level of consciousness in a 35-year-old man who has been in a vegetative state for years.

The report in the US journal Current Biology is based on just one patient, but researchers say they plan to expand their work to others because of the improvements they have seen in the man, who was incapacitated by a car accident 15 years ago.

"Brain plasticity and brain repair are still possible even when hope seems to have vanished," said researcher Angela Sirigu of Institut des Sciences Cognitives Marc Jeannerod in Lyon, France.

"It is possible to improve a patient's presence in the world."

The process involves using a chest implant to send pulses of electricity to the vagus nerve, which connects the brain to other major organs of the body.

Vagus nerve stimulation is already used to treat people with epilepsy and depression. 

The man showed significant improvements in attention, movement and brain activity after one month of vagal nerve stimulation, according to the report.

He began responding to simple orders, such as following an object with his eyes and turning his head on request. He also appeared more alert and was able to stay awake when listening to his therapist read a book.

And he reacted to threatening stimuli in a way he had not for years -- opening his eyes wide when an examiner moved his face suddenly toward the patient.

However, the treatment did not return the man to the way he was before.

Rather, he was classified as having moved from a vegetative state to a "state of minimal consciousness," according to brain scans that showed improvements in areas of the brain involved in movement, sensation and awareness.

This means "consciousness remains severely altered but, in contrast to the vegetative state, there is minimal but definite behavioral evidence of self or environmental awareness," explained Tom Manly, an expert in cognition and brain sciences at the University of Cambridge.