I'm from VietNam , so I don't good English

There is a person with cancer also told me, in times of extreme pain of body scratching disease,a person had been clinically dead. Then, he saw a bright light, then the light as to fly high, no longer feeling pain in human disease, looking down to see his body still lies in a hospital bed. That moment occurred just a few seconds.

I had asked for the case in which the heart stops beating, electroencephalogram recorded no sign of any proven brain electrical activity but also the mental processes such as perception, consciousness, memory, continues to work to revive the patient can tell there is clearly a very early ending time experiences in the brain is considered to be dead ?

If there are any such cases , i think soul is exist