Dehydration Hangover - What's Happening?

The patient that was on life supportand got so much immediate attention, i remember. When they did the autopsy after she died dehydration 13 days later, it was half the size,. Her brain was, it had just shrunk cause of a lack of water. That's interesting and horrifying. It is nfortunately, from everything i've read, every medical professional said, there's no way she can feel pain, right? She's not in a state of consciousness where she can experience pain.