Patient woke up from vegetative state after 15 years

If a person has spent one year in a vegetative state, this is considered permanent - many people never regain consciousness. It is precisely for this reason that it is so surprising that French researchers have been able to increase the awareness of a patient who has been in a vegetative state since a car accident 15 years ago. Brains do not actually work this way.

An illustration shows how the information exchange in the brain of a patient in the vegetative state has increased after the vagus stimulation. © CORAZZOL ET AL

The researchers have implanted a device into the breast of the 35-year-old man, which stimulated his tenth brain nerve (also called the vagus nerve or only vagus). This extends from the head up to the abdominal height and plays a role in the wakefulness state and the attention. After one month of daily vagus stimulation, the dramatic improvements in man's condition exceeded all expectations, as the team reported in Current Biology.

What is a vegetative state?

A person in a vegetative state can breathe alone and experience moments of wakefulness. However, it is not aware of its environment and can not communicate or react to external stimuli. After one year, a vegetative condition is considered a coma.

They are not present in the world, explains the director Angela Sirigu from the Marc Jeannerod Institute of Cognitive Science in Lyon, France.

In a coma, however, the person's eyes are closed. It is possible to recover from a coma and to wake up again completely. A comatose person can also go into a vegetative state or a state of minimal consciousness or develop a locked-in syndrome. The person is conscious, but can not move and can only communicate via eye movements.

Did the man woke up all of a sudden?

No, but his progress was still surprising. From a medical perspective, the patient moved from a vegetative to a minimally conscious state. After a month of stimulation of the vagus, the man could simply follow orders and, for example, turn his head slowly from left to right, says Sirigu.

He could stay awake longer than before, listening to a therapist reading a book to him. He also responded to perceived threats. His eyes widened, for instance, when someone suddenly came close to his face, so Sirigu. People in a vegetative state do not show such reactions.

The man's progress was also visible in cerebral scans. The analyzes showed increased communication between the brain regions and increased metabolic activity.

Brain scans of the patient showed increased activity in the parieto-occipital cortex after the vagus stimulation, in the thalamus and in the striatum. © CORAZZOL ET AL

Could the condition of the man have simply improved on his own?

Probably not. The researchers deliberately chose a patient who had long been in this condition to rule out the possibility of accidental improvement.

What does vagus nerve stimulation induce?

The activation of this nerve triggers signals to the so-called noradrenergic pathways, which are decisive for excitation, attention and the fight-or-flight response. Vagus stimulation is already used to treat epilepsy and occasionally also depression and neurological disorders. This technique has also been used to treat recent traumatic brain injuries.

Uzma Samadani, who has already treated patients with moderate brain injuries by vagal stimulation, is enthusiastic about the results from France.

I strongly support this research, she wrote in an e-mail.

Samadani is a professor at the Department of Neurosurgery at the University of Minnesota.

I do not believe we have yet a comprehensive understanding of the mechanisms of impaired states of consciousness associated with trauma. But the vagus stimulation seems to be promising in this case report.

What does this mean for other people with severe brain damage?

Even if the current case is remarkable, it is only an example. The researchers will have to confirm their findings with the aid of numerous other patients in order to understand the full potential of vagal stimulation.

But if it turns out that the method works in a variety of cases, it could give people with a limited awareness at least a little free will and the possibility to communicate. Sirigu adds that vagal stimulation is probably more effective if it happens shortly after the traumatic brain injury. She would like to investigate this next.

The sooner we can stimulate, the sooner we can intervene in body functions and restore a kind of physical balance, she says.

Is the man now really better when he is conscious of his state?

That is hard to say. His family has refused to publicly comment on his progress. But Sirigu is optimistic.

It is always better to understand than not to be aware of what others are doing or saying, she says. In any case, I would prefer to be conscious.

Source: Current Biology