The blog Practical Ethics reports on pioneering research from a group of scientists in Cambridge who are using fMRI scans to study the brains of people who have been diagnosed as being in a vegetative condition. A Persistent Vegetative State (PVS) is a condition that is characterized by a state of wakefulness without detectable awareness. The researchers found that some patients who have been diagnosed as being in a vegetative state were able to respond to certain stimuli, indicating the possibility of awareness. Although it is encouraging that new medical technologies can assist in preventing misdiagnoses of patients with severe brain injury, the fact remains that few of these patients will ever recover with their former personality and memories intact.
Patients who have been diagnosed with conditions such as Persistent Vegetative State (such as Terri Schiavo) or the Minimally Conscious State (MCS) often suffered serious damage to the brain as a result of severe stroke or cardiac arrest. Although there are rare cases of remarkable recoveries, most patients with such diagnoses have ceased to exist as persons because the parts of their brains that encoded their personalities have ceased to exist.
It is now a well established fact that brain cells do not immediately die after severe hypoxic insults such as stroke or cardiac arrest. Actual necrosis (or apoptosis) takes many hours, or sometimes even days (as a result of a phenomenon called “delayed neuronal death.”). Unfortunately, ischemic insults to the brain exceeding 5 minutes are often sufficient to set parts of the brain on an irreversible path to destruction of the person, even if resuscitation of the patient is possible. Currently, there is no single approved neuroprotective agent that can salvage these brain cells from destruction. Although hyperacute combination therapy may offer hope for people suffering severe hypoxic insults, most of such patients currently would be better served by placing them in a state of biostatis through cryonics before the complete ischemic cascade can run its course.
Although cryonics is often dismissed as speculative, it can be argued that long term preservation of the neuroanatomy of such patients through vitrification offers better hope of recovery as the same person (or any person at all) than immediate resuscitation after the insult. But for acceptance of cryonics as a treatment for patients at great risk of (delayed) severe brain damage to become acceptable, the general public will need more exposure to the technical feasibility of cryonics and perspectives on death that offer a more prominent place to the concept of personhood.