Scientists reveal what happens inside your brain as you die

Scientists have now thrown light on what actually happens inside the brain as you die – with a "brain tsunami" spreading through the organ in the minutes after cardiac arrest.

Experts using neuromonitoring technology on brain-damaged patients were able to detect the moment this "wave" spread through their brains.

The slow-moving wave of chemical changes spreads through the brain in the minutes after cardiac arrest, when the circulation stops.

To begin with, the brain goes into a sort of "safe mode", where inter-cell communication stops, and then the "wave" starts moving.

Then a "wave" of chemical change spreads through the cortex and other areas of the brain, triggering pathophysiological cascades which gradually poison the nerve cells.

This wave remains reversible up to a certain point in time: nerve cells will recover fully if circulation is restored before this point is reached.

It’s known as "spreading depolarisation", say the researchers, and had previously been observed in animals.

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Lead author Jens Dreier of Charité Universitätsmedizin Berlin said, "After 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,” he said.

"Particular challenges include the slowness of this wave that hampers its visibility in normal EEG recordings; however, this discovery may lead to improved diagnostic and treatment procedures in the future, following Max Planck’s motto that ‘insight must precede application."