Friday, November 9, 2007
Session 5: Response to the Council's White paper, "Controversies in the Determination of Death"
D. Alan Shewmon Olive View- UCLA Medical Center
CHAIRMAN PELLEGRINO: Good morning. As the members of Council know and others who have been here before, we have been working on a document on the definition of death as part of the overall approach we're taking to the question of organ donation.
This morning we have invited Dr. Alan Shewmon, who has a long history of involvement with this question, to provide his point of view on the brain death question, which is fundamental and important. So I'm going to ask Dr. Shewmon to take over in just a second and explain to those of you who have just come in that it is our custom not to go into long or even semi-long introductions.
The material and background and curriculum vitae are present for all of the members of the Council... So I'm going to ask Dr. Shewmon, who is a professor of neurology, pediatric neurology... to give us his view on the question of the definition of death. Alan?
DR. SHEWMON: Thank you very much, Dr. Pellegrino. Is this an appropriate volume? Okay. It's such an honor for me to be invited to address this august group, and without further ado, I'll just dive into the material. I'd like to beg your indulgence in my use of the term "brain death." It's kind of out of habit. Maybe the term will change as a result of the White Paper. But I don't like "brain death" so much as a term, myself, but it's just there, and everybody is used to using it. So I will use it for this talk.
So looking back over the almost 40 years of the history of this topic, I still see it as a conclusion in search of a justification. And throughout the literature on determination of death, there are three categories of justifications that have been proposed.
One is loss of conferred membership in human society. This is a sociological concept of death. It is society specific. Some advocates of higher brain death appeal to this rationale. Other advocates of whole brain death appeal to this rationale. The Harvard committee implicitly appealed to this rationale.
The second is loss of essential human properties or personhood. This is a psychological species-specific definition of death, which is pretty much restricted to those who are called the "higher brain death" advocates or "neocortical death" advocates.
I would say, in having discussions with many colleagues about this, that this is the implicit rationale of many advocates of whole brain death today. When you pin them down and ask, "Why do you really think brain death is death," this is what you'll get: "Because there's no person in there, because there's permanent unconsciousness."
Third is a biological kind of rationale, loss of somatic integrative unity or, if you will, the loss of the organism as a whole. This is a biological species-nonspecific concept. It's the concept that corresponds to the mainstream whole brain death view and also the British brain stem death view. It was the rationale of the President's Commission of 1981, and evidently it's the rationale of this Council in its White Paper. It's also my rationale. I think this is a correct concept of death. But what I will try to convince you of in what follows is that brain destruction does not fulfill this concept.
Contrary to popular belief, brain death is not a settled issue. I've been doing informal Socratic probing of colleagues over the years, and it's very rare that I come across a colleague, including among neurologists, who can give me a coherent reason why brain destruction or total brain nonfunction is death.
There's always some loose logic hidden in there somewhere, and those who are coherent usually end up with the psychological rationale, that this is no longer a human person even if it may be a human organism.
Youngner and colleagues did some very interesting surveys in 1985 and 1989, which I'm sure you're all aware of, looking at the attitudes towards brain death and found out a surprisingly high incidence of lack of coherent concepts among people involved in transplantation, incoherence whether the donors are really dead or not.
Japan, Germany, and Denmark are interesting countries to look at their history on this topic because it was only recently that Japan passed a brain-death law, and that law is incoherent insofar as you're legally dead if you're going to become an organ donor, but if you're not going to become an organ donor, then brain death doesn't make you dead.
In Germany, also very recently, the law was changed about this. And there you are legally allowed to extract organs from brain-dead patients, but the law does not explicitly say brain death is death. It's kind of implied, but they just can't quite bring themselves to say that.
Denmark, the Danish Council of Ethics for many years came out with a series of statements reiterating their conviction that brain death is not death and that organ transplantation needs to be justified by some other way. So even on the international scene, this is not a settled issue.
There have been increasing publications of critiques of neurologic determinations of death, and I think very significantly the establishment—and by that I mean relevant medical associations like the American Academy of Neurology, the AMA, and so on—the establishment ignores the conceptual critiques and focuses rather on how to diagnose global brain infarction.
There has been a rejection of the mainstream rationale by an increasing number of high-profile experts, particularly advocates of higher brain death, but also people from the mainstream sort of jumping ship from the biological rationale to the psychological personhood rationale. And I have seen this at conferences a number of times.
And then there are some very interesting Freudian slips by those who certainly know what they're talking about. Here's from the American Medical News: "Brain-dead woman ordered kept alive." Here's from Neurology Today, more recently: "Dr. Ropper"—this is Allan Ropper, a famous neurologist in intensive care neurology who has published a great deal about brain death—"Dr. Ropper added that it has been suggested that children who are brain dead can be kept alive by artificial means for a long period of time."
Now, maybe that was a medical reporter putting words into his mouth, but these are his own words in his own very recent textbook: "In exceptional cases [of brain death], however, the provision of adequate fluid, vasopressor, and respiratory support allows preservation of the somatic organism in a comatose state for longer periods." So here he actually comes out and asserts that this is an organism and it's clearly a living organism because corpses are not comatose.
This is from a neurosurgeon in a textbook on transcranial Doppler sonography. He says, "The findings were obtained in 15 patients who fulfilled the clinical criteria for brain death. All of the patients died within 24 hours or upon discontinuation of the mechanical ventilation."
I think this one is even more significant. This is from a chapter written by Fred Plum, who is one of the major figures in American neurology who has written extensively about issues of coma and brain death. And in this table he lists some cases of prolonged visceral survival after brain death. And look at that column that is circled called "Mode of Death." And the modes of death are "spontaneous cardiac arrest" and "respirator discontinued." So obviously Dr. Plum does not consider these people dead by virtue of their brain being destroyed, but they died as organisms when the respirator was discontinued or they had a spontaneous cardiac arrest.
And this is from Dr. Ron Cranford, another very famous neurologist who has written extensively on brain death. And this is in an article about vegetative state, but what he says about brain death is revealing: "It seems, then, that permanently unconscious patients have characteristics of both the living and the dead. It would be tempting to call them dead and then retrospectively apply the principles of death as society has done with brain death."
These are not lay people who are naive about this topic. These are the experts in the field who kind of indirectly are revealing the degree of conceptual confusion underlying the superficial consensus.
Now, my own conceptual itinerary on this is quite circuitous. As many of you know, I have at one time or another in my life held every possible position on brain death. So I think I understand all the positions quite well and am able to think outside the box, if you will.
From 1981 to '89, I supported the notion of neocortical death and wrote to that effect. I was forced to change my analysis when I came across some hydranencephalic children who in principle ought to have been in a vegetative state, but they were actually conscious, yet they had no cerebral cortex.
So the whole idea of neocortical death had to go out the window, and I reverted to a variation on the theme of whole brain death, which I presented at the Pontifical Academy of Sciences in 1989, and continued to write accordingly up until 1992, when I came across a case of a 14-year-old boy on whom I was consulted in California.
He had jumped onto the hood of a slowly moving car, fallen off, hit his head against the concrete, and within four days was brain dead, certified by a full neuro exam and an apnea test. Parents refused to accept that this was death and insisted with the doctors to continue life support.
Well, since they knew that there is imminent cardiac arrest in this condition of brain death, they thought, "Okay, we'll humor the parents for a few days, and then nature will take its course, and then we don't have to have this ugly confrontation with them."
So they continued for a few days and finally made an agreement with the parents that they would withdraw all support except for the ventilator and basic fluids for 48 hours and if the child passed away, then that was an indication of what God's will was. And if the child survived, then that would be an indication of what God's will was, because the parents were very deeply religious and insisted on doing what they considered to be God's will. But nobody could agree on what God's will was.
So the doctors thought this would be a good way to come to a closure on this. Well, he survived the 48 hours of simple fluids and ventilator support, and now they were in an awkward position to continue support, and they actually transferred him to a skilled nursing facility with the diagnosis of brain death.
And in California, of course, he was legally dead, and the nursing facility was very confused by this. They had never received a patient who was legally a corpse. And they consulted me about this, and I came up. I examined the boy, and lo and behold, I concurred with the diagnosis of brain death. He had no brain functions, and the records supported the apnea test. So he, while in this condition, began pubertal changes and passed away at 63 days from an untreated pneumonia.
So this case flew in the face of everything that I had been taught by my mentors and by the literature regarding the imminence of somatic demise and brain death, and it made me rethink the whole thing. And the coup de grace was an analogy with high spinal cord transection, which I'll go into in just a minute. This forced me to reject neurological criteria for death altogether.
So since 1992 I've been an advocate that death is not neurological, and there have been various things that have supported my conviction about that: the series of prolonged survivors in this state which have been published and I'm sure you're familiar with, the evidence of somatic integration and holistic properties in many of these patients, which we'll talk about.
Also, I've become more and more conscious of conceptual disconnections between the concept, the criterion, and the test of death in the mainstream. And the latest stage in my conceptual itinerary is insights from linguistics. My wife is a linguist, and so we've had very fruitful interchanges over dinner and came out with a couple of publications on the linguistics of death and how the language that we grow up in may influence our conceptual frameworks, including about death concepts. I'm not going to talk about that today.
So let's look at the spinal cord issue, because if you think about it, the effect on the body should be the same for brain destruction as for brain disconnection. Does that make sense? Okay. As far as the body's physiology is concerned, if the body needs brain control to be a unified organism, then it shouldn't matter to the body whether that is lost through brain destruction or brain disconnection. Either way, the body loses that control.
So that's what occurred to me in 1992, and I thought, "Huh, that's interesting. Let's go to the literature on high spinal cord transection and see what the physiology of that is like." And I was very surprised to discover that in the spinal cord literature the somatic pathophysiology of high spinal cord transection is absolutely identical to that of brain death. In fact, you could take a chapter on the ICU maintenance of brain-dead organ donors and you can take a chapter on the ICU management of high spinal cord injury victims and interpose the words "spinal cord injury" and "brain death" and the chapters would be almost identical. They have the same kind of somatic instabilities, complications, and so on.
And if you want to make the analogy really identical, you could add disconnection of the vagus nerve. There's no vagal functioning in brain death, and there is in high spinal cord injury. But sometimes we pharmacologically ablate the vagus nerve to treat cardiac arrhythmias in spinal injury. So if you did that, then there wouldn't even be the vagus nerve functioning that is a difference between the two. Not all brain-dead patients have diabetes insipidus, so that is not necessarily a difference between the two conditions.
So based on this, we have to conclude that if brain death is death on the basis of loss of the organism as a whole, then so does high spinal cord transection equal death of the organism as a whole. Now, the difference is — and the only difference is — there is preservation of consciousness in the high spinal cord injury. So if we maintain the standard rationale for brain death, we would have to say that the spinal cord injury victim is a consciousness in a nonorganism, which doesn't make a whole lot of sense.
And if we accept that spinal cord injury patients are living organisms, then whether brain death is a deep coma or death depends on the philosophy of personhood, not on any biomedical aspects. And if brain death is death on [that] basis..., then so are all other forms of permanent unconsciousness if we want to be logically consistent. And this is why so many experts today implicitly favor the personhood rationale and have abandoned the biological rationale.
Now, let's go into three cases. These are three instructive cases. Two of them are from my published series. One was recently published in Japanese, but I had the opportunity to personally examine him, and I've been working with his doctor in Japan, so I have all the clinical data.
So first of all is the world-record survivor in the state of brain death, whom I call "T.K." in other articles. He was a previously normal boy who contracted Haemophilus influenzae meningitis at age four and a half years. He had a very rapidly downhill course so that by the second hospital day he had lost all brain function and was apneic. A neurological consultation opined that the child was clinically dead. Now, he did not have a formal apnea test, and the reason for that is that this was before any diagnostic standards for childhood brain death had come out. And the only diagnostic standard was the President's Commission guidelines, which said you cannot make the diagnosis under age five. And he was under age five. So nobody gave him a formal diagnosis of brain death, yet clearly he was brain dead.
Now, I want to elaborate a little bit on the evidence for brain death because one of the critiques of my work is that I'm presenting misdiagnoses, and I want to assure you that there was superabundant evidence of the correctness of the diagnosis here. So for the rest of his life in this state he had no cranial nerve reflexes, no spontaneous respiration, including off of the ventilator for up to a minute for purposes of changing tracheostomy and so on.
On day two he had sudden onset of hypothermia, profound hypothermia, also, sudden onset of diabetes insipidus. Both of these are complications of brain death, and there's no other reason that he would have had these symptoms on day two. He has had four EEGs on brain death day zero, which I'm calling the day of onset of brain death, again, the next day, on day 841, and on day 4,202. All four EEGs were absolutely flat at maximal sensitivity.
He had a CT scan on brain death day nine, which showed extensive subarachnoid hemorrhage, diffuse, severe cerebral edema with obliteration of the ventricles and cisterns. And he had splitting of the cranial sutures. The intracranial pressure was so high that his already fused cranial sutures at age four split apart. So that tells you how high the intracranial pressure was at that time.
Multiple independent neurology consults reiterated the lack of neurological function, including my own exam, which I videotaped and will show you in a second, on brain death day 4,969. A few months after that exam when he was 13 and a half years into the state of brain death, they did an MRI scan, which I'll show you, also, an MR angiogram and multi-modality evoked potentials, which I'll show you.
Finally, if anybody still had any doubts, he passed away a couple of years ago, and an autopsy was performed—a brain-only autopsy, which showed no identifiable brain structures, including brain stem structures, and I will show you that, as well. So there's no question that this child was brain dead. He was transferred from the ICU to a regular pediatric ward on day 504, and he was discharged after seven and a half years in this condition. He was discharged to a rehab facility and then to home, and he had four brief hospitalizations during the rest of his time in this condition. He expired after 20 and a half years in the state of brain death. Thirty-seven percent of that time he was in the hospital, 53 percent was at home, and 10 percent was in a rehab facility or skilled nursing facility.
Here's his brain stem auditory evoked potential [referencing projected PowerPoint slide], which shows stimulus artifact and no intracranial potentials. Here's a somatosensory evoked potential, which shows Erb's point at the brachial plexus and no intracranial potentials after that. Here's his visual evoked potential, which shows no response to visual flashes. Here's his MRI scan, a sagittal section, which shows an incredibly thickened skull. Radiologists have never seen such a thickened skull that I've shown this to. And this is due to the failure of the brain to grow during normal childhood, and the skull grows in compensation to that. It's a well-known phenomenon.
But, more importantly, there's no identifiable brain structure in there. There's just a collection of disorganized fluids and membranes and calcifications, including no brain stem. Here's some axial views of the same thing. And here's the autopsy, the outer aspect of the brain, which was totally calcified, and inside was this brownish, gritty material, plus a lot of calcifications. And on microscopic analysis, they were unable to find any neurons. So there's no question that this child was brain dead for 20 and a half years.
Now, upon examining him and going over his records during this time, there are a number of holistic properties that his body demonstrated. First of all, homeostasis of fluid balance, electrolytes, energy balance, and so on, without monitoring and without frequent adjustment based on that monitoring. So he was just given G-tube feedings and liquids day after day after day, and his body made whatever adjustments were needed to keep that homeostasis.
Temperature maintenance—of course, all these patients tend to have subnormal temperatures, but with a few extra blankets he maintained his temperature just fine. Proportional growth—I call it proportional because he did not grow like a cancer. He grew with the normal body proportions, and we'll see his growth chart. Teleological wound healing from surgical procedures or from minor abrasions or from infections. Cardiovascular and autonomic regulation.
So he and all the other patients were very unstable in the beginning. They required pressor medications. But they were able to wean off the pressor medications, and he remained stable in terms of self-sustained blood pressure on his own. He could tolerate a sitting position, which indicates some degree of autonomic control of the blood pressure. So his blood pressure didn't plummet from blood pooling into the legs upon sitting.
And there was a coordinated response to stress in terms of blood pressure, heart rate, and capillary skin changes. He had a febrile response to infections and sometimes mottling of the skin with that. And, I think very importantly, he recovered from various medical crises. Once he had congestive heart failure, got through that. He had hypotensive shock at one point, got through that. He had various infections, pneumonia, urinary tract infection, sinusitis, and with ordinary antibiotics got through all of that.
So I consider these to be holistic properties because they're not properties of any one organ or organ system, but they're properties of the organism as a whole. Here's his growth chart, and his weight eventually ended up at 75 kilograms. And here is evidence of his autonomic reactivity. It's a little kind of a busy slide, but the point is, these spikes in systolic and diastolic blood pressure usually correspond with spikes in the heart rate, and they coincide, the big ones, with environmental stressors like suctioning or turning or so on. So the organism reacts to these environmental stressors in a coordinated manner. Let me now show you his video. He has hyperactive reflexes. He has what we call a triple flexion response where you elicit this Babinski reflex, and the entire legs at hip, knee, and ankle will withdraw.
will briefly come is when I pinch his shoulder the leg will move. So there's integration within the spinal cord across levels of spinal cord. I don't think such movements have any survival value, but it's a sign that the spinal cord is doing a lot of integration there, including autonomic integration, and that's what's important in the somatic organism. So when he's uncovered he did get goose bumps, and he had mottling of the skin. These are the caregivers that took care of him at home during all of this time.
Another case is a 12-year-old girl with a malignant brain tumor diagnosed at age 12. It progressed despite surgery, radiation, and chemotherapy. At age 15 she was already moribund. She was apneic and on a ventilator, had almost no neurological function by that time. She was in the hospital, and they thought she was brain dead at this point, and they did an apnea test which was positive. Nevertheless, she could not be declared brain dead because of a right corneal reflex and a weak cough to tracheal suctioning. These were the only residual brain stem functions that she had.
I would have to say that on the basis of the proposed concept of apneic coma in the White Paper, she would have to be declared dead, although using the mainstream diagnostic criteria, she could not be declared dead because of a right corneal reflex and a weak cough reflex. So they sent her home on a ventilator, and while at home she probably became brain dead on what I'm calling brain death day minus 28. Nobody knows quite when she became brain dead because she was just lying there on a ventilator all the time. Then she had a crisis with obstruction of the ventilator and was brought to the emergency room and admitted where she was formally diagnosed as brain dead, which is what I'm calling brain death day zero.
She had no brain stem reflexes, a positive repeat apnea test, a flat EEG, and no blood flow on radionuclide scan. She was reconfirmed to be brain dead on day 312 by a neurosurgeon, although he did not repeat the apnea test, and she had another flat EEG at that time. The parents took her home because they were convinced that she was not dead, that brain death was not death. They didn't accept what the doctors told them, and the doctors, rather than making a big legal show about it, just discharged her home.
She had a CT scan, which I'll show you, and she expired on 410 days into brain death, officially, which I think was actually 438 days into brain death, 98 percent of which was at home on a ventilator and only 2 percent of which was in the hospital.
Here's her radionuclide scan showing no blood flow into the brain, and here's her CT scan on day 312, and notice that there's total obliteration of brain contents. There's some residual islands of some kind of tissue but not enough to make any brain waves on EEG. There's calcifications in there, and here is an epidural residual of her malignant brain tumor, which has grown out of the skull defect into an excrescence on her forehead.
She exhibited many holistic properties, also, again, homeostasis, again, temperature maintenance, again, teleological wound healing, again, cardiovascular and autonomic regulation. She had a relative paucity of complications. She had one pneumonial, which resolved at home with enteral antibiotics. And I think of great interest is to compare the growth of that tumor with how the multiplication and turnover of her own cells throughout her own body was teleological and unified.
Here's a graph, a scatter plot of her temperatures. Notice here is brain death day zero, what I'm calling that, when it was formally diagnosed. And up till then she had relatively normal temperatures. And then on this day, minus 28, the temperature plummeted and then gradually maintained in this range with the help of blankets. Also notice that she is able to generate some fevers, too.
Here's a scatter plot of her blood pressure and heart rate on the same time axis, and notice that these increased during the days prior to onset of brain death, and this is no doubt from intracranial pressure building up. And then they plummet, corresponding to when the temperature plummeted. And so the conjunction of all of this is what led me to say that she became brain dead at home on that day. Importantly, it gradually stabilizes. She came off of pressor medications during the first hospitalization, which was very brief, right here, and then all of this was spontaneously maintained blood pressure. This is a scatter plot of mean blood pressure versus heart rate, and what it shows is there's coordination between the two with stress responses. So the blood pressure goes up and the heart rate goes up, which doesn't necessarily follow if there was just an uncoordinated group of organs.
Okay, third case. Do you want me to stop or show the third case? Show the third case. I thought so.
So this is a Japanese boy who became brain dead at age 13 months from a necrotizing encephalopathy of presumed viral etiology. He has now been brain dead for seven years, 78 percent of which has been in the hospital and 22 percent at home. He's had three EEGs on day one, day 297, and day 1,617, all of them isoelectric. He's had three brain stem auditory evoked responses, all of them showing no response. He had a SPECT scan, which shows no intracranial blood flow. He's had a total of five CTs and four MRI scans, all of which show progressive disintegration of the brain to disorganized fluids and membranes without identifiable brain structures.
Here's his MRI scan. You can see just what I described. Here's a sagittal view showing no brain stem structures. Here's an absent response to auditory evoked potential. Here's his radionuclide scan showing no intracranial blood flow and SPECT scan showing no intracranial profusion. He also has homeostasis, temperature maintenance, proportional growth, teleological wound healing, cardiovascular autonomic regulation, and recovery from various medical crises.
Here's his growth chart, and here he is. And I'm going to show you him at different ages. Here he is at three years old, at four years old, at five years, eight months old. That's when I saw him and did my own independent exam and confirmed the lack of brain functions. And here he is at eight years old. And I think you would agree with me that if any biologist were put in front of this boy and not primed about any brain death debate but simply asked to examine this and tell us is this a living organism or not, any biologist would say, "Well, of course this is a living organism. This is a comatose apneic living organism."
So I think for the interest of time I will have to forego the other points that I wanted to make, but maybe they'll come out in the question-and-answer session. But I thought these were very important for you to see because a big criticism of my work has been that a lot of this is undocumented. It is not undocumented. It's just that the critics haven't seen the documentation yet. So I'll stop here and be very happy to answer questions.
CHAIRMAN PELLEGRINO: Thank you very much, Dr. Shewmon. I'm going to ask Dr. Floyd Bloom, a member of the Council, to open the discussion.
DR. BLOOM: I was going to respond first to your letter to us, having read our White Paper in its last draft and then talk about your concept of the organism as a whole or your view that unless the organism as a whole is dead the subject is not dead.
You first said in your letter that you didn't like our concept of total brain failure, which we defined as a documented history of injury due to either trauma, stroke, or prolonged hypoxia. You didn't like that because it missed the concept of irreversibility. However, it's hard for me to believe that you actually read the draft since irreversibility was defined in the second paragraph and at least 50 more times throughout the document. So irreversibility is a major part of the state that we call total brain failure.
DR. SHEWMON: May I say something to that?
DR. BLOOM: Well, I have a lot more further, but I wouldn't want it to get lost.
(After conferring with Chairman Pellegrino, Dr. Shewmon agreed to hold his comments until after Dr. Bloom finished his response.)
So we defined total brain failure as a medical diagnosis which represents the neurological standard of death to try to separate out the physical findings and the history of the subject from the actual diagnosis and call it death. You then created several what you called "devil's advocate" positions to try to distinguish those from how we define total brain failure.
And you talked about the locked-in patient on a ventilator simulating these causes. You talked about bilateral injury to the phrenic nerves that would simulate some of the loss of respiratory function and look like pseudo apnea. You talked about deep general anesthesia with no brain activity.
Now, I would submit to you that while those are perfectly good in debating points as devil's advocate positions, they totally miss the prime concept that this is a documented history of injury due to trauma, stroke, or prolonged hypoxia. And so even though some aspects of those physical findings could be reproduced by your hypothetical examples, they do not really counter the position that we chose to create in order to eliminate some of the confusion.
We defined total brain failure as a body that has irreversibly lost the fundamental openness to the surrounding environmental and the capacity and drive to act on that environment in its own behalf. It seems to me that's a very clear-cut description of the loss of consciousness, the inability to acquire and consume for itself the necessary components of life, such as breathing, such as food and water.
And just to make it very clear if you had any doubts, I belong to that reductionistic biological group of people such as the ones you quote, starting with our beloved, distinguished Fred Plum and ending with Dr. Cranford, all of whom will take the position that a person in that state without the capacity for consciousness may have a living body but is not a person.
Now, if I could turn to the document that you sent us, starting on page 308 where you cite Dr. Ropper, Dr. Plum, and Dr. Cranford, you end up with the statement, more or less what I just stated, which is that these bodies are biologically living organisms, which is your central tenet. "But that's irrelevant," he said, "because they are still dead as human beings."
I don't understand why that is not correct. The fact that the brainless or headless body in your example of physiological decapitation is alive because autonomic functions persist is exactly why it's called the autonomic nervous system. It exists to be able to act locally and globally to defend the body before the brain is aware of what's wrong and can send commands to integrate that. But the fact that their body may be alive in some aspects in no way eliminates the fact that they are still dead as human beings.
If we go to page 308, "Everyone who saw the video agreed that the patient met all the clinical criteria for brain death short of a formal apnea test which could not be ethically performed because there would have been no benefit to outweigh the risks." This is referring to your patient, T.K. It strikes me that the decision to keep this body alive for 20 years in the total absence of any surviving brain tissue could not have been morally defensible when he reached the age of five years when a death by brain death could have been declared. And to have seen two more examples of this kind of muddled thinking to keep a corpse alive just strikes me as medically unacceptable.
So your letter points to total brain failure as inadequate because it misses irreversibility, because it talks about locked-in patients who might simulate some components, because it equates general anesthesia loss of conscious function with total brain failure loss of function and creates a condition of bilateral phrenic nerve loss to simulate pseudo apnea, none of which complies with our definition for the cause of total brain failure.
Let me finish by going to two more places in your paper before the Pontifical Academy. Page 320, you talk about—the preceding page defines the human soul with spiritual dimensions that cannot be reduced to physical brain activity, and you list as the properties of that human soul reflective self-awareness, abstract concept formation, and volition. But, in fact, all of those have been reduced to physical brain activity, both with brain imaging and computer brain interfaces.
Your example of the locked-in patient does not meet our criteria because those patients, fitted with the appropriate computer interfaces, can, in fact, escape their locked-in position by moving cursors on keyboards, on computer screens that they can see.
So you go on to say, then, that the key difference between Catholic anthropology and person mind/brain reductionism, of which I would happily agree to be known as a member, "The former admits of such a notion as a permanently unconscious person, while the latter does not." And I would say that's accurate for my position.
And you go on to say for the Catholic, "As long as there is evidence that the body is alive, an organism of the whole," as you have called it, "then the soul and person are present even if rendered permanently unconscious by a brain lesion. Since mental functions presumably continue to be mediated by the isolated brain"—and maybe you would tell us how you know that—"the soul must be informing the brain or the head with the brain, depending on which version of the thought experiment one wishes to follow."
And I'll just end by referring to page 322, which summarizes this entire thought experiment: "...for the reductionist, the brain-dead body is a living 'humanoid organism' but no longer the body of a person... For those who accept an Aristotelian-Thomistic type of spiritual soul, some brain-dead bodies are indeed dead by virtue of supracritical multisystem damage, whereas others (with pathology relatively limited to the brain) are permanently comatose, severely disabled, still living human beings; in either case, death of the brain, per se, does not constitute human death."
So let me ask you, then, really as the question, is this view of organism as a whole the holistic—what was the word you used?—the holistic question, if the organism as a whole is still functioning can the body of that person be dead? Is this really primarily a religiously motivated point of view? A philosophical point of view and not a medical scientific point of view?
CHAIRMAN PELLEGRINO: Thank you, Floyd.
DR. SHEWMON: Okay. Let's see if I can keep track of all of the questions in order. Regarding my comments about the term "total brain failure," maybe it wasn't expressed clearly enough in my letter to the Council, but I certainly realize that no one on the Council would diagnose as brain dead or as in total brain failure examples with cut phrenic nerves and with locked-in syndrome. I mean, that's obvious.
I was talking about simply the term "total brain failure," which, I mean, I guess anybody can take a term and define it however they want and say, "This is how we define it." So if you define it as involving the irreversible aspect, you're certainly free to do that. My objection to the term was that this is kind of an ad hoc definition, which if you take the term at face value, which the rest of the public is going to do, the term itself doesn't imply irreversibility, regardless of your ad hoc definition of it including irreversibility. So that was my objection to the term "total brain failure." But I certainly don't object to the definition as you define the term here. Does that make sense?
So I think it's very interesting that you say that you are in the camp with Dr. Plum and Cranford and so on because this is exactly the point I was making in my talk, that more and more people who understand this issue very thoroughly have gotten away from the mainstream biological rationale for brain death and admit that the only coherent rationale is, indeed, this philosophical position regarding the relationship between personhood and consciousness.
And when I was presenting this at the International Symposium on Brain Death and Coma in Havana some years ago, Dr. Plum was there, and during the question-and-answer session he said exactly what you quoted there, that, "Okay, I admit from your evidence that this is a living human organism, but is it a human person?" And so practically the whole audience at that meeting of all experts in this issue was kind of split down the middle about the philosophy of personhood. And you had a lot of people saying, "If there's no consciousness there's no person," and others saying, "An unconscious person is not an oxymoron. You can have an unconscious person, including a permanently unconscious person, and as long as the biological organism is living, then there's a living organism and a living unconscious person."
So there was no meeting of the minds once this philosophical divide was clarified. But what I found very interesting was there was general agreement that the biological rationale didn't hold water anymore. And so I considered my presentation a success because I wasn't there to argue philosophy but to present this biological evidence, which was new at the time and I think now seems to be generally accepted. But the view that you explained in line with Plum and Cranford I don't see adopted in the White Paper. That's very interesting that you say that because the White Paper doesn't reflect that at all.
Now, regarding keeping these people alive—
DR. BLOOM: Excuse me, but I don't see how you can say that. The exact phrase that I quoted a moment ago, "Total brain failure is a body that has irreversibly lost the fundamental openness to the surrounding environment and the capacity and drive to act on that environment in its own behalf"—that's consciousness. That's conscious interaction with the environment.
DR. SHEWMON: Okay. Well, it's interesting that you say that. That was one of my questions to the Council about the White Paper. What exactly is this drive? Are we talking about a physiological drive, or are we talking about a subjective personal conscious drive? That was not clear in the way the paper was worded. I assumed that you were talking about a physiological drive because elsewhere in the paper you reject the higher brain death camp as a rationale for equating it with death. So what you're saying now seems to accept the higher brain death camp rather than reject it. So I'm a little confused by that.
DR. BLOOM: I guess we have to agree to disagree on whether—
DR. SHEWMON: Okay. Regarding keeping these patients alive at home and so on as being morally unacceptable, by presenting these cases, I certainly did not want to go on record as advocating that we keep all these patients alive. That's not my purpose. I strongly believe that this is morally [?] way extraordinary means that can be legitimately foregone and could have been a long time ago. They were not my patients. So I cannot defend for you the fact that they were kept going all this time. I have simply used them as a point for learning about the physiology of this condition. That's all I can [do].
And regarding the reduction of mind-to-brain activity, well, I don't think the fMRI studies and PET studies and so on justify a reduction of mind to physical brain activity. There's certainly a very important fascinating strong correlation between the two. It certainly doesn't prove any reductionism. But what I have to present here I think is more for the secular audience. The paper that I presented for Rome that you're quoting obviously had some theological aspects because it was for a meeting in Rome.
I don't think that our understanding of death needs to be based on any kind of religious notion of soul. Certainly not. So I definitely respect the differences of view regarding that. I don't think it affects one way or the other the biological arguments regarding the unity of the organism.
CHAIRMAN PELLEGRINO: Thank you very much. I will invoke the Chairman's privilege and extend the discussion to 10:30 and now invite Council members, usual fashion indicating you wish to speak, in order.
DR. GAZZANIGA: Dr. Shewmon, your presentation at the Vatican Council was sent in. I realize you weren't able to be there. But it was not uniformly welcomed in that setting, and other neurologists present—for instance, Dr. Jerry Posner is on record in that book, as well. I think he might be called the senior neurologist in the United States. He simply said that death is a process and "brain death" is a lousy term. Brain death is death, and that furthermore he doesn't know of a single case—a single case—where properly clinically defined brain death led to anything other than death very quickly.
So in my explorations of this and in my friends in the neurologic community, they subscribe to that rather strongly, and they become annoyed when people start to tamper with the definition of brain death. So I'm a little bit mystified. Either you're hanging out with a different group of neurologists than I am—but I'm a little bit mystified when you say the neurologic community is split on this. I don't see it that way at all, and I'd just like to have you comment on that.
DR. SHEWMON: What they're split on is under the surface. I mean, there's a huge widespread consensus that brain death is death. Or use some other term if you don't like brain death.
DR. GAZZANIGA: And follows—let's give you .0001 percent. And follows as described and known by professional neurologists on schedule.
DR. SHEWMON: Yeah. And a slide that I didn't have time to show states, "Why are these cases so rare?" And the slide says that the kind of case that I'm showing you is extraordinary and that certainly 99.99 percent of cases of brain death have somatic death, if you will, within a few days. Now, why is that? Now, I would answer that the reason that is — and the reason Dr. Posner hasn't seen cases like this is — that the diagnosis is a self-fulfilling prophecy. In this day and age and for many decades, as soon as that diagnosis is made, the patient either becomes an organ donor or ventilation is discontinued. So there has been all along no motivation whatsoever to try to maintain those patients. So these cases are rare because the motivation to maintain them is exceedingly rare.
Now, where there is motivation the prolonged survival is not so rare. Okay? So we're talking about the rare cases where there is motivation to push through the acute phase of instability. What are those motivations? Pregnant women who are brain dead is one kind of motivation, personal beliefs like in these cases I showed you—they're rare, but we see them—and cultural or societal reasons, like in Japan. Many of the cases of prolonged survival are in Japan where that society is less open to these ideas.
So to find these cases, one just keeps an eye out, and I had to pay with my own money to fly halfway across the country to make this video of T.K. So I think, rather than say, "Well, this just doesn't occur in my experience; therefore, it doesn't occur anywhere," is not quite fair. These are very well documented cases now, and just because Dr. Posner hasn't seen the documentation, which I will be submitting hopefully soon for publication, doesn't mean they didn't exist. And I think it behooves us to learn everything we can from them.
CHAIRMAN PELLEGRINO: Dr. Carson?
DR. CARSON: I'm sure as a neurologist you've had an opportunity to deal with many neurosurgeons, and as one I generally like neurologists. But as you know, we have a tendency to pretty much cut to the point without endless discussions. And a couple of things that you said I wonder about the basis for.
You indicated that the high spinal cord transection was equivalent, essentially, to brain death, and even though you did mention the vagus nerve, you didn't mention the influences of the vagus nerve on the gastrointestinal tract. You did mention that you could perhaps block some of the effects of the vagus nerve on the heart. I'm not sure that anyone has done the requisite experimentations to say that those two things are equivalent.
Another question I had for you was regarding T.K., who spent two decades in a supported system. You didn't mention whether, in fact, he had undergone puberty during that time, so that's just a question that I had.
And then a century ago what we're talking about here today would essentially have been irrelevant because we didn't have the ability to maintain a brain-dead individual. A century from now we might be able to indefinitely maintain such individuals as we continue to learn more and be able to do more. If we can, in fact, maintain them indefinitely, are you saying that we should simply because of the existence of integrative physiological functions because we can maintain them, because there is a life there? What are the implications of what you're saying? That's one question.
And, also, is it possible that human life consists of more than just the ability to maintain integrative physiological functions?
DR. SHEWMON: Well, thank you for these questions. Let me answer the last two first. I think I already said I don't think we should maintain indefinitely these patients. I think it's clearly an extraordinary disproportionate means that is not morally obligatory and most of the time is not morally appropriate. The point in these cases—first of all, they weren't my patients, so I had nothing to do in maintaining them, but I just am learning from them.
DR. CARSON: No, what I'm saying is what is your point? If, in fact, you're not advocating that we go through these extraordinary mechanisms of maintaining such individuals if they're brain dead—if we're saying that and if the general neurological community is saying that, what is the point of what you're talking about today?
Well, the point is whether they are living, comatose human beings or whether they are corpses, and that point makes all the difference in the world for how transplantation of unpaired vital organs is done. So it doesn't make any difference about withdrawing support, but it does make a difference about transplantation of organs. Then what was the fourth question? I forgot already.
DR. CARSON: The fourth question is is it possible that human life consists of more than just the maintenance of integrative physiological functions?
DR. SHEWMON: Oh, yeah. Of course, normal human life does consist of much more than that. The question here is whether these patients are comatose, severely disabled human beings or are they nonorganisms, corpses. So there are many, many disabled people and many comatose people in ICUs whose lives are very incomplete but they're still living. So I think our issue is not whether they have the fullness of human functions or not. Clearly, they don't. But are they living, severely disabled, comatose people, or are they dead people? That's the question.
T.K. did not go through puberty, and most of the children in my series did not go through puberty. Two of them did. I told you about one of them. And regarding the vagus nerve, whether you pharmacologically ablate the vagus nerve or surgically cut it in some hypothetical thought experiment — if you want to be sure you could do this thought experiment and surgically cut it — and then that would be absolutely the same physiologically as the destruction of the vagus centers in the brain stem.
DR. CARSON: In theory, but what I was asking you is are you aware of the work that has been done to prove that, or is this just a theory? Because as you know, historically, many times we have assumed that we knew all there was to know about a particular function of the brain only to discover later on that there was more.
DR. SHEWMON: Well, all I can say is that reading the literature about high spinal cord injury, the intensive care thereof, there's all kinds of autonomic dysfunction, including in the GI tract, and often they give pharmacologic ablation of the vagal nerve to treat cardiac arrhythmias. So there was so much similarity between the ICU treatment of brain death and the ICU treatment of high spinal cord injury that I thought that comparison was quite instructive.
CHAIRMAN PELLEGRINO: Next I have Professor Gómez-Lobo, then Dr. Hurlbut.
PROF. GÓMEZ-LOBO: Thank you very much for your presentation. First, a general remark. I think it's really fascinating when one sees someone challenging the consensus. I think that culture, science, humanities advance in that way. So if there is empirical evidence, for instance, to challenge a view, I think we should look at it and accept the consequences, wherever that may take us.
Now, I would like to ask a specifically ethical question now. Supposing you're right and these are not dead patients, what would be the consequences for transplantation? In other words, it seems to me that the whole legal system in the United States would have to be revised in order to determine when it would be legitimate to obtain organs for transplantation. Could you please comment on that?
DR. SHEWMON: Yeah. The last slide that I was going to show you was two columns of the ideal and the actual with regard to major socio-legal medical changes in a society. And I propose that the ideal sequence of events is that there's a new concept that's introduced. It's studied. It's agreed upon. Then you have the medical community establish diagnostic standards for it. Then you revise the statutory laws accordingly, and then you put it into practice.
What has actually happened in the history of this topic is in 1968 we start with the practice. Then there is a revision of statutory laws. Then there is an attempt to come up with diagnostic standards. Then there is a scramble to find rationales for the statutory laws, and there is still incoherence and lack of consensus about why destruction or total brain failure, whatever you want to call it, should be death.
And so the actual history of brain death has followed exactly the opposite sequence of events that ought to characterize an ideal major socio-legal medical change. So I think at this point in time it's going to be very hard to change how transplantation is done because it's already so ingrained.
But if we accept that these are comatose living patients, then we need to look for ways of transplanting unpaired vital organs that do not cause the death of those donors. And in some of my writings over the last few years, I proposed a variation on the non-heart-beating donor approach that would allow for recovery of such organs in an ethical way, even on the assumption that these patients are not dead.
And I think the ones with total brain failure or total brain destruction or whatever you want to call it are prime candidates for such an approach to organ retrieval, as well as patients with less-than-total brain failure but who are ventilatory-dependent and in whom it has been agreed independently that it's ethical to withdraw the ventilator because it's an extraordinary means.
CHAIRMAN PELLEGRINO: Next I have Dr. Hurlbut and then Professor Dresser.
DR. HURLBUT: Mr. Chairman, I want to suggest that instead of taking up our subject for the next session that we extend this discussion. We have a White Paper to release, and I think there's a lot to talk about here, and it seems unhappy to truncate this just because the hour comes to an end. Is there really a reason—a compelling reason why we need to talk about the subject that's scheduled for the next session this meeting? Could we put that off and continue this discussion?
CHAIRMAN PELLEGRINO: I am considering that possibility, depending on how the discussion goes.
CHAIRMAN PELLEGRINO: At 10:30 I do think we need a break. And then when we come back we may pick this up again.
DR. HURLBUT: Okay. I want to get down to sort of the fundamental questions, and I'm not sure I can articulate this, and I'm not sure I'm making good points at all. But let me just make a stab at it without committing myself to any position here.
What we're trying to do in our White Paper is arrive at something that isn't just a purely physiological description but that relates somehow to what the intuitive meaning of what it is to be an organism of a specific kind at a specific stage of existence in that organism's life or cessation of life. And so we came to the notion that—to put it in my own words because these aren't exactly the words of the report—but starting with the concept that an organism is by definition a self-subsistent being; that its characteristic is that it has a kind of over-and-against relationship with the world; that it is the executive of its own existence and that different organisms in different ways manifest these properties, some as single cells, some as multi-cellular organisms with different characteristics that define their type of organism and organismal existence.
And then we sought to look at the human organism, and we even retreated back down to the level of mammals because we want to be extra careful here that we don't slip into the dangers of what you're calling the personalistic definition, the higher brain functions. And it does seem like a precautionary approach is in keeping here.
But when I look at your objections based on the idea that there is holistic somatic integration and that these various physiological functions such as response to circulating hormones that then show some of the evidences of puberty, I feel there's a strange disconnect here, and I don't know how to say this because I don't exactly want to declare this entity not an organism because you've just said that every biologist would say that that boy was an organism.
I would actually like to ask my colleague, Dr. Bloom, if he believes that is an organism, but let's save that for a moment. Whatever it is, it doesn't seem to me to be a whole organism in quite the same sense. Is organismal function of semi-integrated functions that involved 30, 40, 50 percent of the body—is that somehow a holistic function, or is it possible that these are subroutines that indicate a kind of mechanical process that doesn't qualify as evidence of a full being?
Now, having said that, I want to agree with you that there's the danger of reifying the brain, of seeing—I mean, I teach a course in ethical issues in neuroscience at Stanford, and I begin my class in the first session, and I make the dramatic statement, "There is no brain." And then, of course, they have to unpack that, which means that the brain is our concept of convenience for talking about a seamless integrated unity of a body. Obviously, the brain is connected to the spinal cord and all the peripheral nerves, but it's also intricately bathed in the circulating fluids and responds within the body as a whole and that the organism is clearly a holistic phenomenon.
But, then again, I don't find the fact that there is a single isolated center producing a hormone that then circulates to what was, indeed, at least once an organism and is set up with a series of natural tissue responses to that circulating hormone that will inevitably respond—I don't necessarily see that as what I would call the holistic somatic integration that is being attributed to it, and I'm not sure I'm right in questioning that, but I'd just like to lay that out as a first question.
Is this really what we're speaking of as a whole human organism, or is it possible that this entity doesn't have this capacity for self-subsistent being for executive functions that we're trying to distill in the White Paper by saying if you can't breathe you're unconscious and have had irreversible brain damage?
And here we really were endorsing the whole total brain failure criterion as part of what we're saying, if I understand it right. Is it possible that your criteria of integrated somatic function just don't rise to the level of what you would use as criteria for a whole human organism?
DR. SHEWMON: Okay. Well, even if for the sake of argument I retract pubertal changes as a holistic function, I think homeostasis and proportional growth are holistic functions that are much harder to argue. I also think we should keep in mind the distinction that Jim Bernat has made very well between the whole organism and the organism as a whole. Clearly, these patients are not whole organisms. And many patients in our neuro ICUs are not whole organisms.
The question at hand is whether these are severely disabled comatose organisms near the point of death or are they already dead. And pointing to all the normal human functions that they lack doesn't answer that question, doesn't get at it, because there are tons of patients in our neuro ICUs who are not brain dead, who do not have total brain failure, who are comatose, who are permanently comatose, and who are apneic, and who are not diagnosed as dead. What's the difference?
One of the slides that I would have shown gives two hypothetical cases, and they're not really so hypothetical. One is a patient who is moribund, has positive apnea test, no brain stem reflexes, but a right corneal reflex and is very unstable, has ventilator support, pressor support, diabetes insipidus, hypothermia. Now, according to present diagnostic standards and according to the White Paper notion of total brain failure, that patient is not dead. On the other hand, you have T.K. or W.M. or M.M. at home on a ventilator without pressor support who are somehow considered dead. Now, this makes no sense to me.
DR. HURLBUT: What I'm trying to get at here is let's use the language of Thomistic philosophy for a moment, and I'm a poor example of the use of it because it's not my background. But let me use it to the degree I understand it. The concept of the soul that Thomas draws from Aristotle is based on the idea that human beings are characterized by a rational soul and that in order to have that rational soul they have to have that unfolding potency. There has to be both appropriate material for the formation of this and that will be the substrate for the expression of rational activity in order to be a human organism from the beginning. And the church, in defending the sanctity of the human embryo from its initiation, affirms that it is that because it will have the appropriate material and the immaterial elements of principle of life to express a rational act. Have I got that right so far?
DR. SHEWMON: I suppose so.
DR. HURLBUT: But the question is, is it not then true that at some level the human organism, to be truly human and even to be an organism, since it either is or isn't a human organism, has to have the biological substrate for rational activity? Or am I missing something?
DR. SHEWMON: I think we're talking about a human organism who had the substrate for rational activity and who now has, we can say, a paralysis of the organ that mediates that activity—not paralysis of the organ but paralysis of the rational activity due to destruction of that organ. I think an analogy to that is if you have a musician like a pianist and you set him in front of a piano in which all of the strings have been cut, you get no music out but you still have a pianist. And even if permanently he's not able to manifest that pianism, he's still a pianist.
So I think something—I mean, if we're going to use the Aristotelian philosophy here, I think something like that applies in this case. If you ablate all brain function from general anesthesia, no one here would say that that is death. But what if hypothetically you continued the general anesthesia indefinitely and you had permanent unconsciousness and permanent suspension of brain function? Does it matter from the philosophical point of view whether the reason for the permanence is because the anesthesiologist doesn't go away or because the brain has been destroyed? I don't think it matters. I mean, it matters from our diagnostic standard. Nobody would diagnose the one as brain dead, of course. But from the point of view of the conceptual rationale and personhood versus consciousness, both are equally permanently unconscious, and I think the one illustrates that that doesn't eliminate the personhood. So I would have to ask why would it eliminate personhood in the other case?
DR. FOSTER: Mr. Chairman, it seems to me as one member that the position of the speaker is absolutely clear. It could be discussed for days or weeks or months about Aristotelian or Thomistic thoughts and so forth. It seems to me that we ought to go ahead and stay on our schedule and take the break, and if there's personal questions between, it seems—there's no doubt I might not agree with the speaker's view, but it's absolutely clear, as it's absolutely clear that the other speakers who had questions about it. So I would say that we ought to go ahead and take the break and continue the schedule as outlined.
CHAIRMAN PELLEGRINO: I would like to give Professor Dresser a chance to make her comment. Please let me finish a second, Rebecca. And then I will take under consideration what both of you have said. We will reassemble at ten of the hour, and we'll see where we go from there. But I think we should explore it. On the other hand, I think your point is well taken, and I will try to make the best decision possible.
Rebecca, would you please tell us how you feel?
PROF. DRESSER: Well, I won't tell you how I feel, but I do have some remarks. Just to clarify our recommendation, the definition that we recommend, no indications of consciousness are discoverable and spontaneous breathing is absent and the best clinical judgment is that these neurophysiological facts can certainly not be reversed. In that state, the organism can no longer engage in the sort of work that defines living things. So that is what we say here, just to clarify.
On the history of the development of the current legal approach, no law develops ideally. But in this case, there was the Harvard Committee, then the task force from the Hastings Center, and then the President's Commission, and then most of the laws came along after that. There were some previous criminal cases where courts had to decide about whether it was a homicide case or some other kind of injury case. But that was really the progression.
I wanted to ask you about your [Shewmon's] definition of death, which is in this paper on 324. You say it's "a single event consisting in the total disintegration of that unitary and integrated whole that is the personal self. It results from the separation of the life principle or soul from the corporeal reality of the person."
And then you talk about criteria for that: "A probably valid criterion close to the moment of death might be something like: 'cessation of circulation of blood for a sufficient time... to produce irreversible damage to a critical number of organs and tissues throughout the body so that an irrevocable process of disintegration has begun'." Maybe takes "around 20 minutes, although there are insufficient data to support a precise duration with certainty... [The] critical number of organs and tissues... will no doubt vary from case to case." And you say, "[This is] similar to the traditional 'cardio-pulmonary' criterion, but a refinement of it, because neither heart nor lung function is necessary for life."
So I guess I wanted to ask you, when we're talking about soft biology and we're talking about a process, do you think it's—there's a fair amount of give in what I just read. Do you think there's inevitably some—wherever we draw—maybe we can't draw a precise line, although I think you suggest that you think we can. But when we try to put it in a particular spot, there will be anomalies. There will be cases where we're just not sure if they fit that spot and it's inevitable because of the kind of thing we're talking about. That's my question.
DR. SHEWMON: Yeah, I would agree with your summary of that. In fact, in the linguistics paper that I co-authored with my wife, we more or less proposed that kind of fuzziness and talk about various moments along this process that could be identified and legitimately could be called death in different contexts, depending on what actions are to be taken. So, yes, I would agree with what you said.
PROF. DRESSER: So I just think that one of the difficulties here is that for legal purposes we often do need a bright line. And it could be that wherever we draw that bright line, not everyone will be happy.
DR. SHEWMON: No doubt.
