• brain death
• brainstem death
• death
• organ transplants

Kerridge et al recently published a paper in the journal about organ transplantation and the diagnosis of death.¹ Although I appreciate the authors’ efforts to present their arguments about such a controversial issue, I found some inconsistencies in this article that I would like to discuss

When Kerridge and his collaborators discussed the origins of the concept of brain death (BD), they emphasised that after the report of the medical consultants on the diagnosis of death to the US President’s Commission was published in 1981,² clinicians equated the concept of BD with brainstem death. In fact, the brainstem criterion was first proposed by Mohandas and Chou in Minnesota, in 1971.³ The Minnesota criteria inspired the UK code, which was mainly adopted in UK commonwealth countries.⁴ This view was afterwards powerfully defended by Christopher Pallis.⁵ After the US President’s Commission report,² a lot of countries, and most US states, accepted the whole brain, and not the brainstem, criterion.⁶

Regarding the “dead donor rule”, with the advent of transplant surgery, interest in definitions and diagnosis of death based on brain formulations really acquired a new urgency. None the less, it is important to point out that the concept of BD as death of the individual, did not appear to benefit organ transplantation, but was a consequence of the development of intensive care. As Pallis emphasised, if organ transplant techniques had never been developed, intensive care procedures would have provided the possibility of supplying life support to those cases with destroyed brains and preserved heart function, and physicians would need to face the clinical syndrome called BD.⁵ When French neurophysiologists and neurologists described the death of the nervous system and coma dépassé, organ transplant techniques were only in the very early stages of development.^5,6

Also Kerridge et al only discussed the notion of integration related to the brainstem death criterion. I have recently discussed and rejected this criterion, proposing a new standard of death on neurological grounds, based on the irreversible loss of consciousness, which causes an irreversible absence of the capacity for integrating the main human attributes with a functioning body.^7,8 My criterion of death is also different from the so called higher brain criterion, because I argue that the criterion of death is related to the irreversible destruction of the anatomofunctional substratum which is necessary for the functioning of the components of consciousness, arousal, and awareness, based on anatomy and physiology throughout the brain.^6–8

Shewmon recently remarked that “clinical evidences of brain death is more attributable to multisystem damage and spinal shock than to destruction of the brain per se”, but also remarked that “the brain role is one of modulating, finetuning, and enhancing an already established and well functioning system”.⁹ If we accept Shewmon’s view, then a specific emotional state could influence—for example, the immune system, either diminishing or enhancing the immune response. We can ask ourselves: can we consider the brain’s effect on other systems, of “modulating” or “finetuning” the highest level of integration within the organism?

Of course activity that can be recorded by encephalogram (EEG) may be preserved in brainstem dead patients, which undoubtedly reflects cortical activity. In cases fulfilling the brainstem criteria of BD with primary brainstem lesions and preserved cerebral hemispheres, stimulation of the non-specific thalamic nuclei might produce some degree of arousal. Hence brainstem death alone is not brain death.^7,8

Kerridge and his collaborators introduced the subject of irreversibility based on the use of human embryonic stem cells for neural system repair. Of course, irreversibility is closely related to the technological advances of any given period of history, taking into consideration the criterion of death operating at that time. Some decades ago a heart asystole usually caused death. Nowadays, reanimation techniques allow patients to recover after several minutes of a cardiocirculatory arrest. Moreover, hypothermia and other neuroprotective techniques can prolong the period of a cardiocirculatory arrest after which a patient can fully recover, the brain being the target organ which definitely defines the quality of life.^6–8 During the Third International Symposium on Coma and Death (Havana, 2000), Alan Shewmon presented a striking video of a boy who became brain dead at the age of four and who, on ventilator support, showed spontaneous heartbeating at that time (16 years later), with a completely destroyed and liquefied brain. Hence, it will surely be possible to keep “alive” a brain dead case, or a decapitated subject, even without a functioning heart, with ventilatory assistance and using some kind of extracorporeal machine, for decades. Are we preserving a corpse or a human being?

I conclude that a definition of human death should not be related to organ transplants. Maybe in the near future, xenotransplants, or cloning techniques which can produce organ and tissues, will replace transplants from brain dead donors. None the less, physicians will still need to face and deal with this controversial state: brain death.