Scientists first observed the final stage of the human brain death
Scientists have for the first time were able to conduct a study of the features that accompany the death of the human brain at the time when this event becomes irreversible. Observing the phenomenon was conducted in several nereanimatsionnyh patients at a hospital. About shared their findings the researchers in the journal Annals of Neurology.
For many years, scientists are trying to figure out the details of what happens to the human brain at the time of his death. Despite the earlier discoveries in this area, progress in research in this direction somewhat stalled. Primarily due to the inability to control properly the process of human death. One of the main responsibilities of physicians is to be avoided if possible death of a man, so the experts are making every efforts on this aspect, rather than some kind of monitoring.
As a result, most of our knowledge about what actually happens to the brain during the transition from living in a lifeless state, based only on the results of animal experiments, as well as the stories and observations of resuscitated patients who were actually on the verge of irreversible events.
Poor little animals slain contributed significantly to the understanding of the conditions and processes that are accompanied by brain death. Thanks to them, we have learned that the brain is part of the so-called state of "energy saving mode" for 20-40 seconds after the start of oxygen starvation, becoming electrically inactive. However, his neurons cease any communication with each other. After a few minutes in the absence of oxygen the brain starts to break, since the process begins splitting ion gradients of its cells, and electrochemical energy wave, called depolarization (or "brain tsunami") extends through the entire cortex and its parts, causing irreversible damage.
However, an international team of researchers led by neurologist Jens Dreyer from the Charité University in Berlin managed to make a real discovery. Scientists have not only been able for the first time to observe the state of the brain at the time of the 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 on the basis of a study of nine patients with nereanimatsionnyh monstrous brain injuries.
"Shortly after stopping the blood supply is the spread of depolarization, indicating the release of the accumulated energy in the electrochemical cells of the brain, and then begin to run toxic processes, ultimately leading to death" - Dreyer explains.
"It is important to add that this process is reversible, until the restoration of the blood circulation of the point."
Resorting to technology neuromonitoring and using subdural electrodes and intraparenchymal probes, scientists have assumed that the propagating wave of depolarization is not a final process of brain death as long as there is an opportunity to restore blood flow and oxygen supply.
"anoxia (lack of oxygen to the tissues) is completely reversible without any visible signs of cell damage, if the recovery of the oxygen level comes to the so-called point of no return, when under the influence of a constant depolarization starts the process of neuronal death," - the authors explain in their work .
For patients with a high risk of injury or death due to brain ischemia or any other type of stroke, this discovery may one day be a lifesaver. Nevertheless, the scientists explain that will spend a lot of work to ensure that doctors could use developed on the basis of this finding suitable therapies.
"To date, direct ways to use this discovery for the rescue and treatment of patients does not exist", - commented on the Dreyer, adding a clear need for new research and observation in order to fully understand the issue.
"Understanding the processes involved in the spread of depolarization is of fundamental importance to develop additional strategies and techniques designed to extend the survival of nerve cells in violation of perfusion (blood supply to the right) of the brain."