When my mom went brain dead, my dad said, "You never know what will happen next—that's life," as if he was trying to tell himself.
Brain hemorrhaging may lead to stroke and, finally, brain death.
I heard a few people who were considered brain dead came back to life in the UK last year and they remembered parts of conversations from when they were unconscious.
If your brain is dead you have brain death.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.