A man in Belgium survived a car accident and was presumed for five years to be brain-dead — until he communicated with doctors through a scan that mapped his thoughts.
A woman in Britain caught a viral infection that left her mute and immobile — until brain-imaging tests showed she was aware of herself and her surroundings.
Both patients, whose eyes could open yet whose brains appeared to be shut down, lay beneath a diagnosis of “vegetative state” that all but ruled out the possibility of thought, much less recovery.
In recent years, however, neuroscientist Adrian Owen has discovered that some people who have been written off can actually understand and communicate. Owen asked one such man to imagine playing tennis when he wanted to answer “Yes” to a question, and to think of his home for “No.”
The man’s face never flickered in response to commands. Yet under a scanning technique known as functional magnetic resonance imaging, different areas of his brain flared with activity, lighting the same language and movement-planning regions that are active when healthy people hear those commands.
The discovery of an “inner voice” in patients who are effectively buried alive has far-reaching consequences for how doctors diagnose and treat unconscious patients with traumatic brain injuries or cardiac arrest. Ethicists say Owen’s discovery raises highly charged questions about what society deems is appropriate life support and whether to consult severely disabled patients on their care.
Owen’s brain scans have been credited with saving the life of Kate Bainbridge, a British woman who caught an infection in 1997, but regained full consciousness after lying in a vegetative state for six months.
“Not being able to communicate was awful. I felt trapped inside my body,” Bainbridge, now 40, told BBC News.
Similarly, the Belgian man, now 30, has begun to respond to simple questions and show distinct traces of brain activity under a functional MRI scanner, which allows doctors to map blood flow, or oxygen use, in different parts of the organ.
The two cases remain rare and do not mean that all unresponsive, brain-damaged people are likely to recover, Owen cautioned.
Nonetheless, his pioneering research shows scientists are still struggling to understand what it means to have a consciousness — an idea that was given a pop-culture twist last summer by Inception, the dream-weaving Hollywood blockbuster.
The notion also taps into a primal fear.
“The very thought that you could be locked inside your body really terrifies all of us at different levels,” Owen, a University of Western Ontario researcher, told federal officials on a recent visit to Ottawa.
To date, Owen and his research team have studied 24 vegetative or minimally conscious patients — too small a sample for scientists to make general observations about why some people are able to communicate.
One theory is that some types of traumatic injuries, often from car accidents, sever the connections among brain cells, but leave the neurons themselves intact. With time, the broken connections can be re-established. By contrast, brains starved of oxygen from cardiac arrest often do mass damage to neurons, leaving virtually no part of the brain unscathed. Under such circumstances, even partial recovery is next to impossible.
By Owen’s calculations, fewer that one in five patients, of the estimated 45,000 to 250,000 a year in North America who are diagnosed with consciousness disorders, is likely to have a measure of brain response.
His research holds the promise of new ways to identify which patients are most likely to regain consciousness. It also exposes the limitations of existing ways to diagnose the vegetative state. Doctors currently use what is known as the Glasgow Coma Scale to measure a patient’s neurological condition at the time of a serious illness or injury.
A 2010 editorial in the New England Journal of Medicine suggested that functional MRI be added to traditional methods of diagnosing patients with consciousness disorders.
Yet because not all hospitals have expensive fMRI scanners, Owen and his collaborators are trying to develop a cheaper, more portable way to find out if someone is actually aware, and to communicate with them if they are.
Owen’s research team has shown that a similar response can be achieved using an Electroencephalography (EEG) machine that measures electrical activity in the brain. However, adapting the technology for the bedside is still at least a decade away.
“This is not something that you’re going to be purchasing at Best Buy next year,” Owen said in an interview.
At 45, the British native is one of 19 high-powered scientists lured to Canadian universities as part of a $200-million federal program known as the Canada Excellence Research Chairs. Under the program, Owen is receiving $10 million over seven years, which will allow him to develop his EEG tool and do more tests on larger numbers of unconscious people.
However, opening a two-way channel of communication with an immobilized, brain-damaged person raises a number of ethical challenges. For example, should doctors ask patients if they are feeling pain? Are patients with detectable brain activity capable of making their own care decisions? Should they be asked if they want to live or die?
Those are some of the questions that ethicist Judy Illes wants to explore. Illes, who holds the Canada Research Chair in neuroethics at the University of British Columbia, is among a team of experts working alongside Owen.
“Imagine that we could, with enormous accuracy, predict who will emerge from a disordered state of consciousness. That would be very powerful,” said Illes.
Yet such a technology could unleash powerful debates about how long life support should be given to a brain-damaged person and whether society can afford the high cost of keeping someone alive artificially for years, or possibly decades.
“These issues have to do with justice and allocation of resources and cultural appropriateness,” said Illes. “We have a responsibility to Canadian society to understand what disorders of consciousness mean across the different cultures that we embrace.”
Sunday, September 18, 2011
The Ottawa Citizen in Canada. In the picture, Belgian man Rom Houben and his mother Josephine Nicolaas Houben (R) and his speech therapist Linda Wouters (L) are pictured at the hospital in Heusden-Zolder, on November 25, 2009. Rom Houben, who is thought to have been in a coma for 23 years, has told of his "second birth" after doctors realised he was in fact conscious, the German weekly Der Spiegel reported on November 23.
Posted by BA Haller at 8:01 PM