Recently someone sent me a number of papers that discussed the biophilosophical underpinnings of brain death. Medical doctors increasingly find themselves in the midst of heated debates about what constitutes death by neurological criteria. It is not hard to understand how controversies can occur in this area. Whenever a patient who satisfies the criteria for brain death shows signs of improvement or recovery, these criteria are called into question. Or, perhaps more troublesome, some people will simply not concede that a patient is dead because recovery can be envisioned. In such cases, the concept of death becomes more like a subjective “decision” than an objective property of the brain.
To someone sympathetic to cryonics these debates are mildly infuriating because it shows the reckless medical myopia with which matters of life and death are approached. When bioethicists debate what constitutes “permanent and irreversible loss of the capacity for consciousness and self-awareness” there is little recognition of the possibility that what looks hopeless and irreversible by contemporary medical technologies may be rather straightforward to repair or recover by future medical technologies. Would we abandon a patient if a cure would be available tomorrow? What about next month? Next year? 50 years?
The standard rejoinder to this position is that cryopreservation of the patient (cryonics) itself produces irreversible damage to the brain and is thus not suitable to stabilize the patient longterm until more advanced treatments are available. But how can we know what will be considered irreversible damage in the future? Should we simply pull the plug based on our guesswork about the limits of future technologies? Would it not be more prudent to let future doctors make that determination?
This does look a lot like saying that cryonics is just an argument in favor of prudence based on ignorance. A sophisticated way of saying, “well, you never know!” Not quite. If a healthy brain without damage gives rise to consciousness and identity, it follows that if the original state of the brain can be inferred from the damaged state, the capacity to restore consciousness and identity is preserved in principle. Ice formation undeniably alters the structure of the brain but it does not make the ultrastructure “disappear.” In fact, at cryogenic temperatures nothing “disappears,” a point that is not even sufficiently recognized by many cryonics advocates. Today we can do better than freezing, though, and use vitrification agents, which solidify into a glass upon cooling to cryogenic temperatures. While these vitrification agents exhibit some toxicity, at the ultrastructural level this expresses itself at most as alteration of cell membranes, protein denaturation, etc., not wholesale destruction.
Where does this leave us on the issue of brain death? For starters, looking at a monitor and concluding that the patient is dead because of the absence of organized electrical activity will tell us little about the ultrastructure of the brain (case in point, at 15 degrees Celsius even a healthy brain will show a flat EEG). It is true that in some cases of brain death absence of electrical activity corresponds to substantial decomposition of brain tissue but it is important to recognize that in many such cases the brain has been permitted to self-destruct at body temperature as a result of trauma and ischemia. When a hospital is faced with a traumatic event of such magnitude that profound cell death can be expected, the most prudent action is to quickly cool the patient and prevent “information-theoretic death.” If the capacity for consciousness and awareness resides in the neuroanatomy of the brain, the first mandate of medicine is to preserve this.
Originally published as a column in Cryonics magazine, March, 2015