Anencephaly

Dec 18, 2015 12:18

I'm on the last day of finals week, finishing up a term paper for a fetal behavior class. My paper is on the neurological development of the premature infant, but along the way, I came up with some interesting ideas that can't go in the paper... so they are going here.

What I noticed, studying fetal development, is this: The brain-stem is responsible for a surprisingly large part of the late-term fetus and newborn infant's behavior. The brain stem is where your cranial nerves connect; these are the nerves that go to your head and face, and they help you move your face, see things, hear things, and taste and smell things. They carry information to the rest of your brain, where it can be processed--but some of the processing is done in the brain stem. And the brain stem sends out signals, too, prompting behavior.

We call it "reflexive behavior" because the signals to move the muscles involved in it come from the brain stem instead of the cerebral cortex. But the cerebral cortex, in a newborn infant, isn't very well-developed yet, and it doesn't have a lot of say in what the infant does, because it takes a while to connect and myelinate all those neurons. So most of the infant's behavior comes from that wonderful, complex brain stem.

What kind of behavior am I talking about here? Lots of things. Sucking; crying; sleeping and waking. Turning toward a noise or a light. Even learning. That's right: The human brainstem is capable of learning. Present the same sound over and over to a late-term fetus or a newborn baby, and the child will habituate and stop reacting to the sound. But when you change the sound to a different pitch, the child begins to react again. That's learning.

Life at this age is simple, and so is behavior. But that's the way it's supposed to be. A person has to build up the basics before those complicated, cortical, conscious behaviors can be initiated. Even in adulthood, most of your thinking is done subconsciously--even if you're autistic and you process more sensory information consciously than most people do, you probably breathe subconsciously.

So... the title of this post is "Anencephaly", and I haven't mentioned that until now. Anencephaly is a birth defect that happens when the neural tube doesn't close--the neural tube is the structure of the embryo, very early on in development, and the top end forms the brain. If the head end of the neural tube doesn't close, then the top of the nervous system doesn't form, and a child is born without a cerebral cortex; there's a head and a face, but the top of the skull, and the part of the brain that ought to be inside the top of the skulll, is missing. Babies with anencephaly, if they survive birth, have a life expectancy of hours to days. Exceptional cases have survived for weeks. Children with hydranencephaly (a milder version of anencephaly involving a closed skull, the cerebral cortex replaced with cerebrospinal fluid, and often some small portions of the brain remaining and functional) have survived for years.

I've read a few stories from mothers of anencephalic babies who carried to term and spent that short time with their babies, whether minutes or weeks, and they're not what you'd expect. The tragedy of losing a child is there, and that's not surprising--but these anencephalic infants don't behave at all like what you would expect. Their mothers describe them waking, sleeping, sucking on a bottle, grimacing, responding to sound, lifting their heads. They kick their legs and wave their arms, quiet when they hear their mothers' voices, and respond to human touch.

All that with just a brain stem.

I used to think that it was mother's love that made these grieving families describe their anencephalic babies' behavior as being so complex, but now, after I've studied embryology, I believe their accounts. "Just a brain stem" is a pretty odd way to put it, once you know what a brain stem is. It's a very complex structure, and lots of our thinking takes place there. When we're very, very young--fetuses, newborns--most of our thinking takes place there. The brain stem forms first, matures first, and serves us well while our cerebral cortex develops. Babies with just brain stems can't live to grow up--without the cortex, their breathing eventually becomes disorganized; and were they to be maintained on a ventilator, their health would eventually fail--but they can behave very much like any other baby.

Knowing that, it seems very sad to me that doctors, when giving a diagnosis of "anencephaly", often imply to their patients that their baby is not really a baby because most of the brain has not developed. They recommend termination, shortening an already tragically short life, as though the simple existence of a newborn with only a brain stem were not worth experiencing. Except... at that age, a typical newborn's cerebral cortex isn't actually doing that much work yet. The cerebral cortex is the difference between life and death, and the seat of consciousness and what will be, about eighteen months later, a sense of self--but a lot of the typical newborn's behavior is still reflexive. All of that, the anencephalic newborn will also have.

Anencephaly is used as an extreme example of disability, and when it's used, the speaker seems to assume that anybody would agree that a life with only a brain stem is not worth living. It's used to introduce the idea that the complexity of one's cognitive experiences can be used to determine the value of one's life. Extended to slightly less severe disability, what if a person's brain is impaired to the point that they will never reach that 18-month-old's concept of "That's me in the mirror"; are their lives worth living? What about those who will never use complex language, will never learn to read, will never graduate from high school... will never... will never... ...

The fallacy here is that you can ever judge a person's life by how good they are at thinking. A brain stem isn't as complex as a cerebral cortex, but it's still something, and most disabled people have much more than that. Maybe doctors look down on those with intellectual disabilities because doctors themselves have to be so intelligent and have been taught, for decades, to value intelligence. They've got their heads in clouds of calculus and anatomy, and they don't know enough theory of mind to turn themselves around and think about what it might be like to look out of the eyes of someone who values things that don't have much to do with being smart.

I think there are a lot of parents out there who've been cheated out of those few, short, precious minutes or hours with an anencephalic baby they were told wasn't worth getting to know. And that generalizes to disability, as a whole. There are a lot of parents who have cheated themselves out of loving their real child, because they were too focused on the will-nevers and the child they thought they would have. There are even parents who have killed their disabled child as though the child were a usurper or fairy changeling, not a child at all.

We've got to stop doing this. We've got to stop judging people by what they can't do. If it's possible to marvel at the complexity of the human brain stem and see beauty and humanity in the short life of an an anencephalic infant, shouldn't it be just as possible to celebrate the lives of other disabled children, no matter how severe their impairments might be? To dwell on the "will-nevers" and "can'ts" is to ignore the things that are possible and the child who is real, and really there.

intelligence & cognition, disability, neurodiversity, quality of life

Previous post Next post
Up