17-yo Melissa Peacock is not a zombie. Or at least she looks like a pretty healthy zombie. To survive, Melissa must process her own brain fluid inside her belly.
You can see how it works in this picture: A tube connects her brain to her peritoneal cavity, carrying the fluid through her body. Yes, the tube itself is permanently embedded inside her because, she says, a previous external tube left her with huge blisters on her back. Before that, eight operations had failed to find the correct solution. Once in her abdomen, the body processes the liquid, absorbing it through the lymph and vascular systems.
While absorbing your own brain fluid sounds gross, migraines, blurred vision, and sure death sound a lot worse. That's why she doesn't care:
My friends think the fact that I digest fluid from my brain is a bit weird—but my quality of life is so much better since I had the shunt put in place, I don't care. It felt like I was constantly trying to see through a steamed-up window. Sometimes I'd have almost no vision at all.
Melissa has suffered from intracranial hypertension since she was nine. The hypertension is caused when the body can't drain spinal fluid out of the skull, which results in a pressure build up that crushes your own brain. The condition can be fatal if not treated. [Daily Mail]