Human Brain is still active Minutes after Heart Stops Beating

Humans could be brought back to life up to five minutes after death.

Medical science is exploring every possible way to enhance the lifespan of humans. Equipment like ventilator was an amazing invention in this regard. Probably the biggest discovery in this regard came out recently when it was announced that human brain continues to work even after the death of the heart. It is a common scene of movies and dramas where a flat line is shown which indicates the death of the patient.

Basically, it is measuring the heartbeat of the patient. But, if we consider that this research is true, the entire definition of declaring someone dead will change now.

Neurologists carried out their experiment on dying brains and used electrodes to detect the movement of brain signals. They came up with following conclusions:

A person’s brain cells continue to function for 5 minutes after his heart has stopped beating.

Consciousness stays for many minutes after the death of the body.

A wave of spreading depression marks the moment when your brain shuts down.  

Scientists studied nine different patients in order to have enough data to support their massive claim. They concluded that there is a flurry of activities in the brain, following an electrical activity, before it shuts down forever. That phase is given the name of ‘Spreading Depression’. Experts think that death should be marked by the passing of this signal rather than stopping of the heartbeat. This study suggests that human brain can be restarted within 3 to 5 minutes after his heart has stopped functioning.

The patients that were observed belonged to different parts of the world (Berlin, Germany and Cincinnati, Ohio) and all of them had suffered serious brain injuries due to which ‘Do not resuscitate’ orders were issued about them. Electrodes were used to monitor the signals of their brains. It was expected that this process will lead to some exciting information and scientists were lucky as they got what they wished for.

It was observed that the neurons present inside the brain continue to perform their designated tasks until the wave of spreading depression. This is when these neurons halt their working and die. Brain cells die when blood stops flowing through them and they are deprived of the necessary oxygen. Lead author of the study, Dr. Jens Dreier of University of Berlin said

“After the circulatory arrest, spreading depolarization marks the loss of stored electrochemical energy in brain cells and the onset of toxic processes that eventually lead to death. Importantly, it is reversible – up to a point – when the circulation is restored.”

Despite this revolutionary experiment, the debate whether a person dies with his heart or his brain goes on. The statement of another team member, Dr. Jed Hartings of the University of Cincinnati holds quite a lot of weight in this regard. He said,

“The chemical changes that lead to death begin with depolarization. We’ve never had a method to diagnose brain death, and we don’t have a way to be certain when all capacity for awareness is lost.”

A closer look at what happens inside the brain when a human is dying will help us to understand it in a better way. When the heart stops beating, the supply of oxygen to the brain is blocked. This leads to a series of processes at the cellular level. These actions are responsible for the eventual death of brain cells. Firstly, brain cells try to consume the energy reserves to continue their normal functioning.

When neurons fail to do so despite their ultimate effort, state of spreading depression is reached. This is when the reversal of death is possible for a limited time. The exact duration of it is still unknown but the figure suggested by scientists is 5 minutes. Having said that, uncertainty is clearly there as it can be seen in the statement of Dr. Hartings, mentioned above.

This research may have no direct influence in medical treatment today but it will surely help in determining the time before which damage to the brain can be reversed. The findings will also impact the treatments for cardiac arrest and stroke. On the other hand, it can raise a lot of questions about the organ donation where death is declared according to the failure of the circulatory function.