Brain death is a condition denoted by irreversible damage that has occurred to one’s brain, leaving an individual unable to respire or perform the essential actions necessary for life. In this case, they are essentially subject to death. However, this condition has sparked up many philosophical debates in the field of neuroscience through which many argue if these brain-dead patients are classified to be alive. This condition brings up the idea “When are we truly dead?” When supported by a ventilator, a brain-dead patient can emit the appearance of life, which may create skepticism for those who may not fully comprehend the basis of what is occurring in the patient at the level of medical diagnosis.
In Dr. Vukov’s talk, he emphasized a distinction between brain death and just the state of being in a coma. A coma is defined as a neurologic state of deep unconsciousness, and is a component of brain death. One of the criterion for diagnosis of brain death is the establishment of the patient slipping into an irreversible coma. In a sense, the brain must show no signs of activity and electroencephalograms must exhibit an absence of electrical activity. The dreaded “flatline” on the EEG which measures no signs of activity is an important component of determining brain death. There is often confusion as people use the terms “coma” and “brain-death” interchangeably like they mean the same thing. Although brain-death involves a patient slipping into an unconscious state, it may not be the most accurate way to use this in the context of brain death.
An unusual incident occured that changed the perspective on how an individual could still demonstrate potential signs of life in deep levels of coma. A patient who suffered from a heart attack fell into a coma. The doctors noticed the formation of unrecognizable V-shaped electrical signals before falling back down to the standard “flatline”. This phenomena caught their attention and further work was done to identify these strange spikes that indicated signs of life. A study was conducted at the Universite of Montreal to examine these electrical signals. Researchers placed 26 cats into comas through anesthetic isoflurane. EEG recordings were monitored until they observed the “flatline”. After this point, the dosage was increased to allow the cats to enter a deeper coma. During this period, they observed a “revitalization” of electrical activity in EEG recordings that resembled sharp and low-frequency waves. This was an astounding observation as one would expect deeper levels of coma to exhibit the maintenance of a “flatline” but the complete opposite was observed. The origins of these electrical spikes were traced back to the hippocampus, responsible for memory formation. The electrical pulse created by this region of the brain extended to other areas, even reaching the outer cortex. A possible explanation for this phenomena was that in a healthy brain that is consciously awake, the cortex is responsible for the governing of signals. However, in the coma-induced cats, the hippocampus took over this role and transmitted signals as a form of neuroprotection. This allowed the connections within the brain to persist and maintain signaling pathways. These V-complex electrical spikes were proposed as a mechanism of preservation to slow the deterioration of a patient that has gone extensive periods without using their brain.
The talk given by Dr. Vukov in conjunction with this unusual study emphasizes the implications in the complexity of brain death diagnosis and how even the term itself may seem misleading. The definition of “Brain Death” is consistently evolving with changes in medicine, which shows that this topic is just naturally complex as it’s hard to conceptualize it physiologically. Technological innovations to preserve the body once the brain has passed sparked up ethical issues that attempt to fool families into thinking their loved ones are still alive in an effort to comfort them. Now there’s seem to be a problem where even the brain itself can play tricks even after giving the appearance of death, which can throw off medical practitioners as well. Brain-dead patients will undoubtedly never reach these V-complexes in EEG recordings, but these measures add a layer of blurriness between using coma as a criterion for brain-death. This brings attention to the fact that an irreversible coma may not be the best attribute to describe one as brain-dead as the brain seems to work in mysterious ways that currently may be beyond our comprehension in medical diagnosis.
Jacobson, Roni. “Peculiar Brain Signals Found in ‘Flat-Lined’ Patient.” Scientific American, 24 Sept. 2013, www.scientificamerican.com/article/peculiar-brain-signals-found-in-flat-lined-patient/.
Powell, Tia. “Brain Death: What Health Professionals Should Know.” American Journal of Critical Care, 1 May 2014, ajcc.aacnjournals.org/content/23/3/263.
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