Nerve implant ‘restores consciousness’ to man in persistent vegetative state
A 35-year-old man who had been in a persistent vegetative state (PVS) for 15 years has shown signs of consciousness after receiving a pioneering therapy involving nerve stimulation.
The treatment challenges a widely-accepted view that there is no prospect of a patient recovering consciousness if they have been in PVS for longer than 12 months.
Since sustaining severe brain injuries in a car accident, the man had been completely unaware of the world around him. But when fitted with an implant to stimulate the vagus nerve, which travels into the brain stem, the man appeared to flicker back into a state of consciousness.
He started to track objects with his eyes, began to stay awake while being read a story and his eyes opened wide in surprise when the examiner suddenly moved her face close to the patient’s. He could even respond to some simple requests, such as turning his head when asked – although this took about a minute.
Niels Birbaumer, of the University of Tübingen and a pioneer of brain-computer interfaces to help patients with neurological disorders communicate, said the findings, published in the journal Current Biology, raised pressing ethical issues. “Many of these patients may and will have been neglected, and passive euthanasia may happen often in a vegetative state,” he said. “This paper is a warning to all those believing that this state is hopeless after a year.”
The vagus nerve, which the treatment targeted, connects the brain to almost all the vital organs in the body, running from the brain stem down both sides of the neck, across the chest and into the abdomen. In the brain, it is linked directly to two regions known to play roles in alertness and consciousness.
In surgery lasting about 20 minutes, a small implant was placed around the vagus nerve in the man’s neck. After one month of vagal nerve stimulation, the patient’s attention, movements and brain activity significantly improved and he had shifted into a state of minimal consciousness.
Recordings of brain activity also revealed major changes, with signs of increased electrical communication between brain regions and significantly more activity in areas linked to movement, sensation and awareness.
Similar stimulation has already been shown to help some patients with epilepsy and depression.
Sirigu and her team now hope to apply the same technique to patients with less serious brain injuries, where even more substantial improvements might be possible. There may even be patients, she said, whose cortex (the part of the brain used for cognitive tasks) is intact, but who have brain stem injuries that have led to limited awareness or consciousness.
The findings offer hope to the families of patients in PVS that it may one day be possible to re-establish some basic form of communication. However, some might also question whether such patients would wish to be made more acutely aware of being in a severely injured state.
Read more at www.theguardian.com
Trackback from your site.