Journal of Neurology & Neurophysiology

A Visual Essay on The Neurology of Death and the Dying Brain

Patricia Rigas^{* *}Correspondence: Patricia Rigas, Editorial office, Journal of Neurology & Neurophysiology, Brussels, Belgium, Email:

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Introduction

Neurological skill can also be used to ease the transition from life to death, even if the practised neurologist's main goal is to safeguard and restore brain function.

The identification of brain death in a potential organ donor is the most obvious situation where this skill is required . Additionally, when it is believed that brain-injured patients are unlikely to enter brain death prior to the discontinuation of life-sustaining therapy, Donation After Circulatory Death (DCD) is increasingly used. Neurologists are frequently consulted in these situations to confirm that any meaningful recovery of brain function is futile, which necessitates expertise in neuroprognostication.

Further, knowledge about the cellular processes in the brain taking place after circulatory arrest is important to determine how much time should pass between cardiac stopping and obtaining organs. This is a significant ethical concern because the amount of time elapsed is adversely connected with the tissue quality of organ transplants but positively correlated with the likelihood of lost brain function. Additional intricacy is added by recent attempts at brain resuscitation in an animal model [1].

Additionally, despite its mystic undertone, Near-Death Experiences (NDE) are objectively testable, and neurology may provide a window into their meaning. Temporoparietal lesions, N-Methyl-D-Aspartate Receptor (NMDAR) hypofunction , Rapid Eye Movement (REM) sleep intrusion and migraine aura are some of the proposed molecular causes underpinning NDE that are all well-known to neurologists.

In an effort to quickly inform busy neurologists on important aspects of death and the dying brain, this paper outlines accessible summary that includes visual data. The project is based on a lecture that was scheduled to be delivered at a conference that was postponed in 2020 owing to the COVID-19 pandemic. As a result, rather than offering a thorough and strictly balanced analysis of the literature, its goal is to amusingly share the author's personal viewpoint [2].

Discussion

Nelson and colleagues postulate that danger, whether actual or merely perceived, activates neural circuits that result in REM-associated reactions. This qualifies as a "diathesis-stress model" The sensation of REM sleep intrusion is indicative of an abnormally sensitive arousal system (i.e., the diathesis), which would predispose persons to NDE under stressful or life-threatening circumstances. Possible contributory variables include temporoparietal dysfunction, NMDAR antagonistism, and migraine aura. This model appears to be in line with the observation that the semiology of NDE appears to be the same under conditions of both real danger and the potential for compromised brain physiology (e.g., during resuscitation after cardiac arrest), as well as under conditions of real danger but without any indication of compromised brain physiology e.g., during sleep de (for instance, a near-miss traffic accident) and in situations where there may just be a slight threat but no actual risk (e.g., meditation). In any scenario, the person must have lived without suffering any severe brain damage in order to recall an NDE many years afterwards. We can draw the conclusion that it appears likely that some of us will experience elements of a NearDeath Experience (NDE) during the course of dying and just before loss of consciousness and immediate death, but we may never know how many of us because no one will ever have the opportunity to provide this information after they have passed away for obvious reasons. It is unknown whether terminal SD is compatible with the possibility of any conscious perception [3-4].

Given that NDE is a worldwide occurrence that has been maintained in humans for many years, the question of whether it has a particular biological function arises. Leaving aside metaphysical reasons, the author speculates that NDE might be advantageous for evolution. There are innumerable instances of animals playing dead saving lives throughout the animal kingdom . Thanatosis, also known as death-feigning, is a phylogenetically highly maintained phenomena that affects both invertebrates and vertebrates,including mammals and possibly humans. When all other anti-predator defence strategies, such as fight or flight, are ineffective, thanatosis is the final line of protection . It is characterized by the sudden onset of immobility, with or without loss of tonic muscular activity, and unresponsiveness to external stimuli, while awareness of the environment is fully preserved . This is comparable to the aspects of REM sleep incursion into alertness that can occur in NDEs, such as lucid dreaming and cataplexy . Thanatosis enhances the likelihood of escaping from serious danger, and because it is a heritable behavioural feature, it can develop naturally through selection for survival fitness . It seems reasonable to say that panicking in instances of unavoidable danger is never a desirable option for humans [5].

Conclusion

As demonstrated above, neurologists are qualified to respond to scientific queries about the change from life to death. The alignment of brain death guidelines across nations, increasing organ donation rates through DCD, determining the length of the "hands-off period" prior to organ procurement, developing methods to detect and prevent terminal SDs in intensive care patients with brain injury, and determining whether or not thanatosis can be verified as the evolutionary origin of thanatosis are some of the major areas for future research and activities. Additionally, in the possibly not too distant future, neurologists will be asked for their thoughts on moral issues pertaining to attempts at brain resuscitation . In a well reported study. Recently, researchers demonstrated that they could maintain cytoarchitecture, slow down neuronal cell death, and restore vasculature and glial cell responses in addition to active cerebral metabolism and synaptic activity in the pig brain 4 hours after death. Although the absence of global electrocorticographic activity eliminated the possibility of recovery of consciousness, this demonstrates that limits are being pushed in the neurology of the dying brain just like they are in any other area of clinical neuroscience.

References

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