In a complementary cross-sectional study, 126 community cardiac arrest survivors reported similar experiences plus a fifth type, “delusions,” or “misattribution of medical events,” for example, “I heard my name, over and over again. All around me were things like demons and monsters. It felt like they were trying to tear off my body parts.”
“Many people label recalled experiences of death as ‘near-death’ experiences, but they’re not,” Dr. Parnia said. “Medically speaking, being near to death means your heart is about to stop. But the whole point is that these people are not near death. They actually died and came back from it.”
One of the big implications of the study, he said, is that “a lot of physicians are taught that somehow after, say, 3-5 minutes of oxygen deprivation, the brain dies. Our study showed this is not true. It showed that the brain may not be functioning, which is why they flatline. But if you’re able to resuscitate them appropriately, you can restore activity up to an hour later.”
Because some clinicians questioned or dismissed previous work in this area by Dr. Parnia and others, the latest study used EEG monitoring in a subset of 53 patients. Among those with evaluable EEG data, brain activity returned to normal or near-normal after flatlining in about 40% of images; spikes were seen in the delta (22%), theta (12%), alpha (6%), and beta (1%) waves associated with higher mental function.
“The team recorded what was happening in the brain during real-time CPR using various tests of consciousness, including EEG measurements and tests of visual and auditory awareness using a tablet with a special app and a Bluetooth headphone.”
“Incredibly, we found that even though the brain flatlines, which is what we expect when the heart stops, with professionally given CPR even up to about an hour after this, the brainwaves changed into normal to near-normal patterns,” Dr. Parnia said. “We were able to identify these brain waves in patients while they were being resuscitated, which confirms the fact that people can have lucid consciousness even though they appear to be unconscious.”
Asked what implications, if any, his work has for current definitions of brain death and cardiac death, Dr. Parnia said that the problem is that these are based on the concept of “a permanent irreversible loss of function,” but “that’s only relative to what medical treatments are developed at a given time.”
Potential Mechanism
Dr. Parnia and his team proposed a potential mechanism for recalled experiences of death. Essentially, when the brain flatlines, the dying brain removes natural inhibitory (braking) systems that are needed to support daily functioning. This disinhibition may open access to “new dimensions of reality, including lucid recall of stored memories from early childhood to death,” he said.
From a clinical perspective, he noted, “although the brain stops working when it flatlines, it does not die within 5 or 10 minutes of oxygen deprivation.”
This is contrary to what many doctors believe, and because of that, he said, “nobody has tried to find treatments or new ways to restart the heart or prevent brain injury. They think it’s futile. So, with this work, we’ve opened up the window to developing cocktails of drugs that could be given to patients who have technically gone through death to bring them back to life again.”