fMRI reveals conscious activity in vegetative brains

It’s been seen in numerous movie and television dramas – the brain damaged patient, one with no outward sign of consciousness, who actually can hear, see, or think in an almost normal way. The doctors counsel, “Talk to him. It may do some good.” In dramas the patient usually recovers – talks, is grateful. In real life, not so much. The statistics for recovery are not good, and even if some recovery is made, there is usually permanent damage to some brain functions. In trying to assess the amount of brain damage, doctors have been mostly limited to bedside tests. They try to determine each patient on the spectrum from ‘brain dead’, to ‘permanent vegetative state’, ‘coma’, or a ‘minimally conscious state’; but these categories are a good bit subjective, so mistakes are made. Some of these mistakes are now being found by technology, through the use of functional magnetic resonance imaging (fMRI). A particularly dramatic case has recently been reported by a new study in the New England Journal of Medicine.

The study extended research done in 2006, which used fMRI on a patient with no apparent sign of consciousness in seven months, but who could respond correctly to direct commands, as seen in brain activity scanned by MRI. Fifty-four patients diagnosed to be in a permanent vegetative state were examined. They were each asked to do two things: First, imagine that they were playing tennis; second, that they were walking near their home. The research team had already determined where in the brain these thought patterns would be expressed in normally functioning brains. Of the fifty-four, five were able to hear the requests, understand what was asked, and do the visualizations. (All five were victims of physical brain damage, not oxygen deprivation, which indicates this type of injury has a better chance of recovery.) One of the five was able to go further and use the brain activity from the two questions as equivalent to ‘yes’ and ‘no’ in response to other questions. In short, he was conscious enough to answer five out of six questions. There was no response to the sixth question.

While from these tests of fMRI activity it was not possible to accurately assess the total damage to the brains of each patient, it was clear some few that are diagnosed as in a permanent vegetative state may have one degree or another of active consciousness.

Does this change our view of consciousness? Some think yes:

“In my view, this paper is a breakthrough in cognitive science and in neurology, and it will probably be the basis for a more open discussion of what it means to be awake, alert, and human,” says Allan Ropper, a neurologist at Brigham and Women’s Hospital in Boston, who wrote a commentary accompanying the paper in the NEJM.

“This is a first case, but at least it shows that technology is challenging the boundaries based on clinical bedside examination,” says Steven Laureys, head of the coma science group at the University of Liege, in Belgium, and one of the authors of the paper. “I’m convinced that we need to adapt our standard of care and our ethical and legal framework to take account of this new technology.” The researchers did not test the other four patients who could do mental imagery, mainly because of the difficulty of carrying out the tests.

[Source: Technology Review]

Others might say that consciousness has long been a difficult state to define. We’ve been aware, for a century or two, of consciousness existing in those with no means for communication. Modern technology is helping to get a better handle on that state, but the qualities of consciousness are still open for debate. This leaves the ethical questions.

For example, is the absence of a ‘positive fMRI scan’ a true indication of a state of no consciousness? Supposing that we can communicate with some patients via fMRI, can we presume they are able (and fit) to make judgments about their condition and treatment? fMRI procedures are cumbersome, difficult for this type of patient, and very expensive – in short, a relatively typical procedure for adverse cost-benefit analysis. (In countries where insurance drives many medical decisions, this too is a pressing ethical decision.)

The intriguing and perhaps astonishing use of fMRI to communicate with a presumed unconscious patient typifies the type of ‘wonderful’ effect technology can have on our sympathy for an individual and the individual’s story. At the same time, it leaves big gaps in the reality where most patients of this type do not recover, and even if there is some response, it is no guarantee of anything resembling a ‘meaningful life’. Put another way: In a public narrative (in extremis, the Terri Schiavo case in the United States) the drama evokes sympathy and even outrage. Outside of a public narrative, in the day-to-day routine of medicine and family life, most decisions fall toward ‘letting them go.’ We’ll see how much MRI or similar technology will change that outcome.

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