A study of seven terminally ill patients found identical surges in brain activity moments before death, providing what may be physiological evidence of "out of body" experiences reported by people who survive near-death ordeals.
Doctors at George Washington University Medical Faculty Associates recorded brain activity of people dying from critical illnesses, such as cancer or heart attacks.
Moments before death, the patients experienced a burst in brain wave activity, with the spikes occurring at the same time before death and at comparable intensity and duration.
Writing in the October issue of the Journal of Palliative Medicine, the doctors theorize that the brain surges may be tied to widely reported near-death experiences which typically involve spiritual or religious attributes.
At first, doctors thought the electrical surges picked up by electroencephalographs were caused by other machines or cell phones in the rooms of dying patients, lead author Lakhmir Chawla told Discovery News.
The EECs were being used to monitor patients' level of consciousness as doctors and families wrestle with end-of-life issues.
"We did it when patients want to withdraw life support, to make sure patients are comfortable, as we withdraw care," Chawla said.
The medical staff kept seeing spikes in patients' brain waves just before death.
"We thought 'Hey, that was odd. What was that?'" Chawla said. "We thought there was a cell phone or a machine on in the room that created this anomaly. But then we started removing things, turning off cell phones and machines, and we saw it was still happening."
The doctors believe they are seeing the brain's neurons discharge as they lose oxygen from lack of blood pressure.
"All the neurons are connected together and when they lose oxygen, their ability to maintain electrical potential goes away," Chawla said. "I think when people lose all their blood flow, their neurons all fire in very close proximity and you get a big domino effect. We think this could explain the spike."
It's possible a cutoff of oxygen would trigger a similar but recoverable event that becomes seared into memory.
"Not everyone reports this light sort of business. What you hear most often reported (in near-death experiences) is just a vivid memory," Chawla said.
Brain researcher Kevin Nelson at the University of Kentucky, who studies near-death experiences, said it's well known that when the brain is abruptly deprived of blood flow it gives off a burst of high voltage energy.
"It's unlikely with conventional brain wave recordings during death that they're going to see something that hasn't been seen already," Nelson said.
Chawla and colleagues would like to follow up their case study with a larger pool of patients outfitted with more sophisticated brain activity sensors.