File this one under “uh, what”. A study has found brain activity in a patient up to 10 minutes after their life support was turned off, in other words after they were clinically dead.
Published in The Canadian Journal of Neurological Sciences, the study was led by the University of Western Ontario in Canada. The researchers examined the electroencephalogram (EEG) recordings from four patients, which is a test to determine brain activity.
A patient is considered dead when their heart is registering no activity on an electrocardiograph (ECG) monitor, a flatline. Traditionally, this is when the time of death of the patient is given.
This surprising study, though, found electrical activity in the brain of a patient after their heart had flatlined, among other indicators of clinical death. The activity consisted of a burst of delta waves, often associated with deep sleep. It hints that how someone dies is a unique experience.
EEG activity had ceased for three of the four patients before their ECG flatlined. But for one of the patients, there was a burst of delta waves 10 minutes after death. And the authors were at a loss to explain why it occurred.
It’s hard to read too much into the results at the moment, considering this is a single case. The study also suggests the possibility the results could be due to an unexplained error in the equipment, although there did not seem to be any malfunctions.
“It is difficult to posit a physiological basis for this EEG activity given that it occurs after a prolonged loss of circulation,” the researchers wrote in their paper. “These waveform bursts could, therefore, be artefactual in nature, although an artefactual source could not be identified.”
It was also noted that there was no evidence for a so-called “death-wave”, a surge in brain activity sometimes alluded to moments before death. Instead, they found no link between the moment each patient’s heart stopped beating and their EEG recordings.
The researchers suggest their findings could pose complications for organ donation. With death currently being determine by circulation, they say there could be “medical, ethical, and legal concerns”.
And Neuroskeptic notes that “the small sample size and the fact that all of these patients were severely ill, and on heavy sedative medications, makes it hard to know how far the findings will generalize.”
But it’s certainly interesting, and further complicates research into what happens to our bodies after death. ScienceAlert said that a pair of studies in 2016 found more than 1,000 genes functioning days after death. Perhaps don’t run around saying there's life after death just yet, though.