How the Brain Dies

I'm fascinated by stories like that of Jahi McMath, the body of which is currently being preserved via feeding tube and ventilator in a California hospital at the behest of her Baptist family. McMath died Dec. 9 of complications from, of all things, a tonsillectomy. A heart attack shut off the 13 year old's blood flow and in the process, McMath's brain was starved of oxygen and died. So: brain death. Jahi McMath is gone.

I'm not fascinated by death; I'm fascinated by the nonchalance of death. Having children, whatever: the big event in all of our lives is death, and death is happening in a death tsunami all the time everywhere. As just another snatch of provisional DNA, death is our main obligation to the universe. If we're not dying, we're just wasting the cosmos' time. Even in your most twisted fantasies of being neuro-imprisoned in a digital database, you're just spinning wheels. Death is really where the future's at.

We know a bit by now about what goes on in the brain, and this tells us some pretty interesting things about death. One of those things is that death is not obvious, or necessarily obvious. In fact, you can very neatly be dead and alive at the same time, in a sense. If, for example, if all of your brain dies except some of the autonomous stuff in the brain stem, you can go on breathing and "living" while having forever forfeited the ability to have a thought, let alone interface with the world. This is post-death. Faux-life.

People confuse post-death with life because not only do you still have the body there in front of you, but it does stuff. The body reacts to its environment just the same. This doesn't mean, however, the brain is enlisted in the activity because the body does plenty of things reflexively without ever bothering with the brain, like shrink from pain or heat. So post-death can sometimes even do a pretty decent impression of life, though you really need to be properly alive to feed yourself or, indeed, have thoughts.

The truly frightening thing in the case of Jahi McMath is that it's not thoughts that seem to matter to the family. "I believe in God, and I believe that if he wanted her dead, he would have taken her already,” Nailah Winkfield, the girl's mother, told the New York Times. “Her heart is beating, her blood is flowing. She moves when I go near her and talk to her. That’s not a dead person.” It's a lower standard for life than it might first seem.

If you were to look at McMath's brain you'd find necrotic tissue, dead cells. The brain isn't like gasoline in a car engine; when it runs out of oxygen, the brain doesn't just sit there waiting for you to fill up the tank. Brain cells don't have a stable passive state. It's sort of the opposite of that actually. Brain cells need energy to not self-destruct. It's like a car needing a running engine not just to move forward but to not collapse in on itself.

Specifically, neurons need energy (metabolized with help from oxygen delivered by the blood) to work molecular "pumps" that keep sodium ions (which your brain uses to move around electrical signals) from building up to the point that neurons become electrically depolarized. Once that happens, the depolarization cascades around the brain in a process called excitotoxicity, spreading from neuron to neuron and setting off a kind of alarm in the cells that allows calcium ions to build up to toxic levels. The result of this is "derangement" in the cell to the point that it loses metabolic functioning. It's like if the cylinders in our engine were all suddenly the wrong shape and in the wrong place. You'd no longer have an engine; you have a bunch of random metal. Junk.

The damage delivered to a brain starved of oxygen moves at the speed of metabolism. Any effort at slowing that down may slow down the damage incurred by the brain. Mainly this manifests as induced hypothermia, in which a patient suffering blood loss to the brain is put under an ice blanket, lowering their body temperature and lowering their metabolism. A lower metabolism means less need for oxygen in the brain and neurons that are less in a hurry to destroy themselves. The catch is that it has to be done before the damage sets in, which can be anywhere from five to eight minutes. Beyond a very narrow time frame, the damage is done: the brain is dead.

A thing medicine can't do is rebuild brain cells back up from the molecular level. While science can slow down some of the above processes, it's not like we can just take a really tiny set of tools and make a trillion fixes in your brain to give you life again. When enough of your brain cells are broken/fried, you're just dead. I've seen necrotic tissue on my own very body and it's frightening and supremely weird (thanks, brown recluse), like having a patch of burned wood implanted in my skin. It is not post-dead, it's just dead.

You can dump all of the oxygenated blood you want onto that charcoal, but it won't come back to life. It's no longer a thing meant to receive oxygen and nutrients. Keeping it attached to a human body that's in the business of supplying those necessities of life is all the more absurd when you understand the actual physical situation of brain death. The desperate cling to faux-life really just says that thoughts and feelings and all of the other stuff that a brain enables don't matter, and that some appearance of life is life. Which is insane and only turns life into a trivial point.

The situation now is that McMath's family wants Children's Hospital, where she's been kept faux-alive since early December pending the decisions of various courts—all of which have sided with death in the case—to insert tracheotomy and feeding tubes so that the body can be moved elsewhere and kept in its current state of post-death. Meanwhile, the hospital has stated again that the only place it will allow the body to be moved to is the county morgue, where it can finally get some rest.

@everydayelk