Scientists were able for the first time to conduct a study of the characteristics that accompany the death of the human brain at the time when this event becomes irreversible. The observation of the phenomenon was conducted in several derealisation patients of a hospital. On their findings, the researchers shared in the journal Annals of Neurology.
For many years scientists are trying to figure out in detail what is happening with the human brain at the time of his death. Despite the earlier discoveries in this field, research progress in this direction has somewhat stalled. Primarily because of the inability to control the process of human death. One of the main responsibilities of physicians is to avoid the death of a person, so the experts exert all efforts on this aspect and not on some kind of monitoring.
As a result, most of our knowledge about what actually happens to the brain during the transition from living to non-living condition, based only on the results of experiments on animals, as well as on the stories and observations of resuscitated patients that were actually on the threshold of this irreversible event.
Poor murdered animals have made a significant contribution to the understanding of those States and processes, which are accompanied by brain death. Thanks to them we learned that within 20-40 seconds after the start of oxygen starvation the brain is part of the so-called state of “energy saving mode”, becoming electrically inactive. Moreover, its neurons stop any communication between them.
After a few minutes, in the absence of oxygen, the brain begins to break down, it begins the process of splitting of ionic gradients of cells, and a wave of electrochemical energy, is called depolarization (or “brain tsunamis”), spreads across the cerebral cortex and its departments, causing irreversible damage.
However, an international group of researchers under the direction of neurology Jens Dreyer from the University charité in Berlin managed to make a real discovery. Scientists were able for the first time to observe the state of the brain at the time of termination of his life, but also found that “brain tsunami” that is, the end point, after which the brain finally dies, you can stop. Such a conclusion they did based on the study of nine derealisation patients with terrible brain injuries.
“Soon after stopping the blood supply is spreading depolarization, indicating the release of stored electrochemical energy in the brain cells then start to run toxic processes, eventually leading to death,” explains Dreyer.
“It is important to add that this process is reversible up to the point to restore the circulation of blood.”
Resorting to technology of neuromonitoring and using subdural electrodes, as well as intraparenchymally sensors, the scientists came to the assumption that a propagating wave of depolarization does not represent the final process of brain death as long as there is the possibility of restoring blood flow and oxygen supply.
“Anoxia (lack of oxygen in the tissues), totally reversible without any visible signs of cell damage, if the recovery of the oxygen level is to a so-called point of no return, when exposed to constant depolarization starts the process of neuronal death,” explain the authors in their work.
For patients with high risk of injury or death of the brain due to ischemic or any other type of stroke, this discovery could one day be a life-saving tool. Nevertheless, scientists explain that still have a lot of work to be done before doctors were able to use was developed on the basis of this discovery, appropriate therapy methods.
“At the moment direct ways to use this discovery for the rescue and treatment of patients does not exist,” commented Dreyer, adding the obvious necessity of new studies and observations in order to fully understand the issue.
“The understanding of the processes involved in the propagation of depolarization, is of fundamental importance for the development of additional strategies and methods aimed at prolonging the survival of nerve cells in violation of perfusion (normal blood supply) of the brain.”
Scientists have observed the final stage of death of the human brain
Nikolai Khizhnyak