Our spirit is not dependent on the brain or body. It is eternal, and no one has one sentence worth of hard evidence that it isn't.
There is no scientific explanation for the fact that while my body lay in coma, my mind - my conscious, inner self - was alive and well.
As a neurosurgeon, I did not believe in the phenomenon of near-death experiences.
I understand what happens to the brain when people are near death, and I had always believed there were good scientific explanations for the heavenly out-of-body journeys described by those who narrowly escaped death.
I'm not the first person to have discovered evidence that consciousness exists beyond the body. Brief, wonderful glimpses of this realm are as old as human history.