Near-death experiences are firmly rooted in medical lore. Many people who have been close to death or resuscitated report a similar experience: Feeling an "out of body" experience, seeing a bright light and experiencing a flood of memories. Many people consider the experience spiritual in nature, but a study published online this week reveals physiological markers of the event.
Researchers at George Washington University studied seven patients who had normal brain function but were fatally ill and whose families had chosen to withdraw end-of-life care. The patients, who had various illnesses including cancer, heart disease or multi-organ failure, were monitored with a device that measures level of consciousness as well as an electroencephalogram device that measures brain waves. The study showed that, in each case, loss of blood pressure was followed by a decline in activity related to consciousness. But then a spike of electrical brain activity appeared on the EEG recording in the moments just before death.
This burst of activity in all seven patients was comparable and consistent in duration.
The researchers suggest that because the spike in brain activity occurred when the patient had no blood pressure, patients who suffer "near-death" experiences may be recalling "aggregate memory" stored in the nerve cells of their brains.
"Near-death experiences have been documented by a large number of people," the authors wrote. "Interestingly, these descriptions tend to have a similar theme in that the recollection is vivid and detailed. ... The end of life is a poorly studied area of clinical medicine and deserves more attention."
The study is published online in the Journal of Palliative Medicine.
-- Shari Roan
Photo credit: David Zalubowski / Associated Press