Persons not vegetables: Dead, alive, and the in-between
Once upon a time there was dead and there was alive. The twain did not meet nor intersect outside of religious miracles. The era of dead-or-alive lasted for millennia until the 20th century when technological advances inserted an in-between state that consisted of alive only because of medical assistance. The first crack in the dead-or-alive edifice started with ventilators, machines that enable the heart to beat and body tissues to receive oxygen even as the brain sits inertly idle. As a result of ventilators and other medical innovations, a population of brain-dead people arose.
Brain-dead refers to an individual with a beating heart but no brain function. An unconscious person with no brainstem reflexes (e.g. corneal or vestibuloocular) who is not breathing is brain-dead.
The brain is the portion of the central nervous system within the cranium, the large cavity of the skull. It includes the forebrain (cerebral cortex, thalamus, basal ganglia) and brainstem (midbrain, cerebellum, pons and medulla). The spinal cord, peripheral nervous system, and retina are not part of the brain. The exclusion of the latter parts of the nervous system is why I always feel as though I am cheating when I substitute brain for nervous system (as in Understanding the Brain). Obviously the former is more catchy but the latter is my true amour.
This post is the first of two, Here I sketch out the states of consciousness as we currently understand them. In the follow up post, I will lead readers on a What if? journey that brings the issues of brain injury home to each and every one. I could not have written these posts without having read Rights Come to Mind, a brilliant book on the ethics of brain-injured patients by Joseph J Fins. If you find this topic interesting, Dr Fins’ book is a must-read.
In his book, Dr Fins provides the history of brain injury and of neurological diagnostic categories. He also follows many individuals’ journeys, showing the impact of brain injury not only on the injured person but also on the loved ones of that person. Novel treatments pioneered by Dr Nicholas Schiff and others are described in gripping detail. Finally Dr Fins compares the treatment of brain injured patients to that of other marginalized peoples. This final section indeed brings civil rights to mind.
Transplants render organs from the brain-dead useful
A major motivation to create a category of brain-dead people arose from the medical advance of organ transplantation which began when Christian Bernard performed the first human heart transplant in 1968. In the same year, a committee at Harvard Medical School chaired by the anesthesiologist and pioneering bioethicist Henry K Beecher (unrelated to Henry Ward Beecher and his sister Harriet Beecher Stowe) redefined life and personhood. The living dead were seen as potential material for the truly living, wasted if not used. Since brain-death is not a state from which recovery is possible, Beecher’s group proposed that organs from brain-dead-and-cardiac-alive people could be put to use, saving others. Thus was born the concept that people with a beating heart could be dead. The result was organ donations for critical surgeries. Organ donations also provide the material for elective surgeries such as corneal transplants (important but still elective). Bioethicists work out the priorities – who gets which organs, when, and for what – and give depth and meaning to informed consent or refusal on the part of donor families and recipients alike.
In essence, what was created was a system in which physicians harvest organs from one group of patients to save a second group of patients, all of whom would have been considered alive prior to 1930 or so. Beecher viewed the brain-dead person as a non-person, irreparable and sufficiently broken as to be considered dead. He used this perspective to erase any obligation that he or the medical world had to this new category of human, the brain-dead. At the same time, Beecher felt it was a medical obligation to aid those in absolute (and now elective) need of new organs such as heart, kidney, lungs, corneas and so on. This perspective has come to rule the day. The tension, and potential for conflicted interest, between a physician’s obligations to an unconscious patient as organ donor and the hypothetical future organ recipient is obvious.
The Karen Quinlan case shifts the landscape to reveal the valley of the persistent vegetative state
The false tidiness of dividing people into dead/dead, alive/alive, and dead/alive (brain/heart) categories was exposed by the case of Karen Quinlan. Karen Quinlan was not brain-dead but rather in a persistent vegetative state (PVS). This essentially means that at least some circuits in her brainstem, the so-called vegetative ones, were functional. These circuits supported “vegetative” functions such as breathing, swallowing, eye-opening and even rudimentary facial movements. Yet, Ms Quinlan’s forebrain was damaged so far beyond repair that she was not conscious and would never again “feel, sing, or think” in the words of the great Fred Plum, neurologist extraordinaire and pioneer in our understanding of patients with compromised consciousness. Although Ms Quinlan’s eyes were open, they did not follow the goings-on in the room but rather “saw through” her family. Ms Quinlan’s parents did not feel that this was a life that their daughter would want and wanted her taken off the ventilator. The hospital objected and the case went to court. The judge ruled in favor of the parents and the ventilator was shut off. Ms Quinlan’s brainstem kept her breathing and alive for another nine years before she died in 1985.
The right to die when faced with life as a “vegetable”
I do not know who came up with the term vegetative but obviously, it is not exactly a neutral term. And the term has had a major effect on public opinion. People recoil at the idea of being doomed to life as a vegetable and not as a human. I don’t think that we can underestimate the linguistic contribution to the huge shift in public opinion from “I want to stay alive by any means possible” to “I would never want to live as a vegetable.” Thus a sizable portion of the public has come to believe that people should have the right to die.
The right to die movement has won many public victories including legal ones that have resulted in legalized forms of suicide for terminally ill patients. As a consequence, a dignified and self-realized manner of dying for people with terminal illnesses can now be achieved in some states and countries. This advance is exemplified by the recent story of Brittany Maynard who by moving from California to Oregon (which has a Death with Dignity law) was able to control the timing of her own death.
Note that most (possibly all) right to die-inspired laws require that the dying person perform the physical act (e.g. pushing a button) that leads to their own cardiac death. This requirement means that a patient with a progressively paralyzing disease such as amyotrophic lateral sclerosis has a delimited time window in which to actualize their own death. It also means that patients in a vegetative state, whose predicament fueled the right to die movement, cannot take advantage of these laws. The loved ones of PVS patients can refuse treatments but they cannot act to stop the patient’s heart.
Sleep-wake cycling is not a cognitive function and is present in VS patients
To recap, at this point, we have added one more category to the three previously existing ones:
In the above table, alive means at least one function is working. Dead means none of the functions are working.
The vegetative state may look deceptively normal because of one important feature, namely, the presence of sleep-wake cycles. The VS patient cycles between sleep and wake, opening their eyes appropriately during the daylight hours. This is accomplished through circuits that involve the hypothalamus, brainstem and spinal cord. We see sleep-wake cycling via one muscle, the superior tarsus, a smooth muscle in the upper eyelid. Its contraction, controlled by spinal sympathetic neurons, is entirely involuntary. You can no more contract your superior tarsus willfully than you can prevent its contraction. Thus, when we see someone cycle through eyes-open and eyes-closed, we are viewing the work of sympathetic neurons, not that of voluntary motor pathways.
In sum, the vegetative state can be viewed as “wakefulness without awareness” (quoted by Monti et al 2010). In the next section, we see that cognitive function is not an all-or-none phenomenon.
Is there someone home inside that brain-injured person?
In the 1990s stories emerged that raised the profoundly troubling possibility that some patients, classified as vegetative might be more than proverbial vegetables on the inside.
I remember the first time I realized the possibility of someone being home in an unresponsive, brain-injured patient. Dr Schiff and I have known each other since our own memories began; our mothers went to the University of Chicago (yeah I know…) together, became friends and served as maids of honor for each other. The Schiff and Mason families vacationed together. I am a few years older and recall my excitement when it became clear that Dr Schiff and I shared a deep interest in neurobiology. At the annual Society for Neuroscience meeting, we would always visit each other’s posters and catch up. And that is how I heard, in the mid 1990s, of the remarkable finding that would be published a few years later in a paper entitled, “Words without mind.”
In the 1990s, Dr Schiff and his collaborators showed that playing the voice of a loved one talking to a patient classified as PVS elicited a brain response that could be measured by fMRI or PET. This response was normal in the places where it occurred, indistinguishable from the response of a control healthy subject. Thus, there was someone home, despite all appearances to the contrary!!! At least some of the patients that were at the time left to live out their days in nursing homes, without the opportunity to rehabilitate and recover as much as their injured brain would permit, had some internal life akin to our own.
Terry Wallis un-vegetables himself, making clear that we need a new category
Dr Schiff’s finding as well as individual case reports fractured the four-part taxonomy above and in the early 2000s, the cracks broke wide open. Terry Wallis exemplifies the diagnostic issue. Mr Wallis was a young man who was in a bad automobile crash in 1984. He did not speak and was placed in a nursing home from which his devoted mother brought him home frequently. Although he was deemed to be in a vegetative state, it turns out that he had some consciousness. In 2003, 19 years after Mr Wallis’s injury, he said “Mama” when asked by an attendant (who had absolutely no expectation of receiving an answer), who was coming toward him. With hindsight, it is now clear that Mr Wallis transitioned from a PVS into a minimally conscious state (MCS) fairly early on in his recovery. However, at the time of Mr Wallis’s awakening, no widely accepted framework existed with which to understand what had happened. MCS was only officially defined as a diagnosis distinct from that of PVS in 2005, two years after Mr Wallis spoke that first fateful word (which were followed by many, many, more).
The minimally conscious state
What is MCS? Well it is a state where at least some parts of the forebrain are functioning. There is a range of behavioral patterns that fits into MCS. At first, a person typically shows only intermittent signs of engagement and response in the form of responding to commands (blink if you can hear me), tracking people with the eyes, and occasional utterances. This can be frustrating as a loved one sees evidence of, say, eye-tracking which then does not recur when a physician comes to visit. Luck and patience are needed for the fluke-like events to happen at a medically convenient time.
The Terry Wallis case and similar others bring a very disquieting idea to the fore. If people who are in a vegetative state can get better and become minimally conscious, is it possible that we have been pulling the plug on brain-alive people? This is a very real fear. The recovery from brain injury varies across individuals. Substantial, even relatively complete, recovery happens in some but not all. And there is variation across time too. A patient who at one week is completely unresponsive may emerge into at least some degree of consciousness after 3, 6, 12 months or even after decades. Patients in a VS can enter MCS. And MCS patients can get better, even becoming fully conscious. The rate of improvement varies widely from glacial to extremely rapid. The end point of a patient’s recovery can also vary from still 100% dependent on support to independence, albeit often with neurological deficits such as aphasia. While some patients remain unresponsive forever, others transition out of the comatose realm and into MCS and some may eventually achieve full cognitive recovery. Jean-Dominique Bauby, James Brady, and Tracy Morgan all emerged from unresponsive to fully conscious after a brain injury.
The succession from coma to VS to MCS to consciousness is not an uncommon one; one study found that almost 70% TBI patients recovered consciousness and 20% were able to live independently. The journey out of coma has been traversed by many including James Brady, Bob Woodruff, and Tracy Morgan. Others such as Sonny Bono, Natasha Richardson, Ariel Sharon or John Stroger appear to have never regained consciousness after becoming unconscious (many details about the latter two have never been made public). Stroger and Sharon died months and years later, respectively, without ever showing any signs of recovered consciousness.
To appreciate the arduous journey back from severe brain injury, check out the Adventures in Brain Injury blog of my friend and former MOOC student Cavin Balaster. [Also take a listen to Cavin’s and my recent conversation, along with Alek Hess, about brain injury.]
Right now, we cannot predict with any assurance who will transition into MCS and who will not. There are a couple of clues. One is that brain injuries that result from a lack of oxygen (termed anoxia) have a worse prognosis than those with traumatic (meaning mechanical – e.g. hits, knocks) injuries. Second, people need brain tissue with which to forge a recovery. If neuronal death is too widespread, hitting key areas of the thalamus and frontal cortex, recovery is simply not possible. Finally, as time goes on, the likelihood of starting a recovery lessens. Thus, a person who has remained in a vegetative state for 12 months or more without any sign of recovery is relatively unlikely to ever improve. Of course, this assumes that the person has been given the opportunity to show improvement, something that often does not happen as a brain-injured patient may be placed in a nursing home after some months without any evident recovery.
Cognitive function without motor capabilities
The real lesson of the sequential additions of vegetative and minimally conscious states to the consciousness taxonomy is that there is a continuum of states possible. The categories, important as they are for setting standards of care and insurance policies, are simply linguistic conveniences. The reality is that there are at least two distinct features that characterize ones state of consciousness. One is the level of cognition possible and the other is the capacity for voluntary movement.
The conundrum is that in order for us to recognize cognition in another, we depend on the other’s voluntary movements. The demonstration of cognitive ability requires forebrain-directed movement. If a patient can’t move, that patient could be cognitively aware, even fully so, but would be unable to communicate their thoughts. This is a locked-in state, about which I wrote in a guest blog. The late Jean-Dominique Bauby, who I discuss in my book and also in a previous post, had locked-in syndrome as does Patrick Stein, a young man living in the Chicago suburbs, and Dawn Faizey Webster, a young British woman. All three had or have locked-in syndrome but none were entirely locked in. Mr Bauby and Ms Webster could blink their eyes and in that way wrote books; Ms Webster graduated from University. Mr Stein has the ability to make some facial expressions as well as eye movements. In contrast, a completely locked-in patient has no ability to voluntarily move any muscle, not even an eyelid or extraocular (one that moves the eye) muscle. No facial expressions, no eye movements, no blinks, no nothing.
Putting ourselves in the shoes of a brain-injured patient’s loved one
This post is long enough and it is time to lay down my “pen.” In the follow up post, we will imagine that our own loved one has just had a severe brain injury and has been rushed to the hospital. We have to decide what to do. Do we grant our beloved the right to die with minimal suffering? Or do we ask the doctors to do all they can to save our loved one’s life? How does our decision change a year down the line? or two or five? These issues are not for the faint of heart but thinking and talking about these issues now, before anything happens, can help a lot.