Consciousness in Persistent Vegetative States

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A study published last week in the New England Journal of Medicine concludes that 40% of diagnoses of brain disorders are misdiagnoses. These are people diagnosed with conditions such as being in a persistent vegetative state, which is often taken as sufficient for removal of life support because of the assumption that no person remains.

This study finds that a significant percentage of people who are diagnosed as being in such a state are not only conscious but can even be made to communicate simple "yes" or "no" by being told to think about some concrete thing if they mean "yes" and a different concrete thing if they mean "no". Different parts of their brain would be active if they were conscious and given these instructions, and that could be detected, A number of these patients were thus able to communicate after being declared to have brains of jello with no possibility of consciousness.

This calls for a massive rethinking of how we should interpret what's going on in persistent vegetative state diagnoses. Either there are different conditions that look the same for all that can be detected (prior to this new method of detecting consciousness, anyway), or the one state that's been called a persistent vegetative state is fully compatible with consciousness, despite what doctors have assumed. Our courts have relied on that judgment to excuse what turns out to be the killing of a conscious human being. This new research raises the standards pretty steeply for when we should make life-or-death decisions based on such diagnoses.

The LifeNews article about this study includes a suggestion in the opposite direction. If these patients can indicate, consent, can't they be asked if they want to die? The doctor the article quotes as being interested in this does acknowledge that there are still problems with consent. I don't think the article shows much awareness of how significant such problems are. It's notoriously difficult to know when someone has rationally consented even if they can communicate in complete sentences, and this doctor thinks he can get patients who can only use this roundabout method to give legal consent to being killed? How will they determine whether the person is being rational in consenting? Congress prohibited the selling of organs, because it's too easy for people at the lower end in terms of income to be manipulated into giving up their organs. Shouldn't we extend at least as much courtesy to those who might be manipulated into giving up their lives?

[cross-posted at Evangel]

5 Comments

The argument that first won me over to opposing the death penalty was the number of false convictions in our system.

That number doesn't come close to 40%.

This is pretty stunning.

It is sad, though predictable, that it took very little time to look to whether this meant we could get people to consent to being killed.

Whereas I think we need (a) to increase the standards for conviction on capital crimes and then execute a far greater percentage (i.e. almost all) of those who can be convicted of them under those much higher standards or (b) to have a two-tiered system of conviction, with higher standards needed for capital convictions but standards like our current ones allowable for conviction for the same crime without the capital penalty.

It's not just that it took very little time for them to look to that question. It's that the questions we should be asking should take us in exactly the opposite direction.

I read the paper. Some things from the paper appear to have been misinterpreted. It is known that a significant percentage of people can be misdiagnosed (~40% in this case) (BMJ 1996;313:13-6, Neurology 1993;43:1465-7, BMC Neurol 2009;9:35). The point of this paper is that they have a new method for diagnosing and, in one case, communicating with people originally diagnosed as being in a vegetative state (VS) or minimally conscious state (MCS). Five of the 54 patients were able to modulate their brain activity in the test, and of those three were found to show some behavioural response on retesting (i.e. 3 out of 5 showed physical response as well as modulated brain activity). One of the five patients was able to use this method to answer yes/no questions correctly.

It's NEJM, this is obviously going to be pretty impressive stuff, I look forward to more information.

There are some ethics questions this raises, and I'm not sure you approached them as soberly as you should. Science is slow (they started this in 2005).

As soberly as I should? When an ethical argument is based on the claim that someone has no conscious experience, and a study like this raises serious doubts about whether we can know if such a thing is true, the sober thing to do is to refrain from using such arguments until we know more. It's not to suggest that we can get consent from someone to kill them.

"A number of these patients were thus able to communicate after being declared to have brains of jello with no possibility of consciousness."
One patient was able to communicate who may also have been eligible to be declared dead. One other was able to signal consciousness. The other three who could signal consciousness were also minimally conscious according to behavioural tests (i.e. the bedside test).

" The doctor the article quotes as being interested in this does acknowledge that there are still problems with consent. I don't think the article shows much awareness of how significant such problems are."
The doctor in the article is also the president of the American Society for Bioethics and Humanities, I think he probably doesn't believe that "he can get patients who can only use this roundabout method to give legal consent to being killed." In fact in both the LifeNews article and the New York Times article that they quote he specifically cautions against overreaching with questions because of the communicative limitations.

"This calls for a massive rethinking of how we should interpret what's going on in persistent vegetative state diagnoses. Either there are different conditions that look the same for all that can be detected (prior to this new method of detecting consciousness, anyway), or the one state that's been called a persistent vegetative state is fully compatible with consciousness, despite what doctors have assumed."
All indications are that these hidden consciousnesses only occur in traumatic brain injury patients and not in the other conditions which result in vegetative states. Persistent vegetative state is the diagnosis of a syndrome; it is definitively incompatible with consciousness, which is why there's a second class of MCS.

The study reinforces the very public doubts that many people have been having since the first court ruling of legal death for a patient in a persistent vegetative state. The research in the short term gives doctors a new tool for diagnosing borderline cases of VS. In the future similar brain scanning technology could be used for communication.

The public discussion of the press releases for these kinds of scientific studies will almost always reinforce your beliefs one way or the other. I am opposed to the death penalty in almost every case, and I am opposed to the termination of a patient who cannot consent in almost every case; this study will give my arguments weight when I need it, and otherwise it's just a cool new idea.

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