Has anyone been born without a brain? originally appeared on Quora: the knowledge sharing network where compelling questions are answered by people with unique insights.
Answer by Fabian van den Berg, (Neuro)psychologist and data analyst, on Quora:
In the literal sense, yes, humans can be born without a brain. Cases like that are called hydranencephaly, where the hemispheres don't develop.
The oldest that these kids get is a few years, with exceptions that grow to be six or ten. Functionally, they tend to be very limited.
Hydrocephalus is a different scenario where the brain is filled with fluid. Here, the presence of fluid is devastating to the surrounding tissue. In one notable case, the mother was told three months into the pregnancy that her son had an array of health issues. Among those issues was spina biffida and hydrocephalus. This child was born with just 2% healthy tissue. The parents were told that survival was unlikely, were offered termination, and they were pretty much looking at coffins.
But against all odds this one made an astonishing recovery. After three years of not knowing if he'd survive, a checkup revealed the brain bounced back and is now fully functional, albeit with some disability. The recovery is thought to be largely caused by the relief of pressure when the fluid buildup was shunted.
In a less literal sense, we can broaden this to see to what extent humans can function with the loss of brain matter. If the brain gets time to cope with the loss gradually, rather than sudden damage or never having it in the first place, things turn out differently.
There once was a forty-four year old man in France who had some muscle weakness in his left leg. He couldn't find a cause and was rather uncomfortable, so he decided to go to the local hospital for help. The man led a normal life, was a civil servant, had a wife and two kids. There was nothing peculiar about him, except one thing. As an infant he had hydrocephalus (water on the brain); this was treated using a shunt that was removed when he was fourteen.
Perhaps this wasn't very successful; it had been thirty years, so to be safe the doctors ordered CT and MRI scans and found this.
Literally a head filled with water. The black areas should look like the image to the right, but instead are filled with cerebrospinal fluid. All areas were shrunken down into the strip along the outside.
This case, and the one before, defy everything known about what it takes to be alive. Sure this man wasn't a genius with an IQ of 75, but he was functioning quite well. He had memory, speech, emotion, thoughts, the whole shebang.
His case shows the incredible plasticity of the brain. If so much damage was done in a short time, the brain wouldn't be able to cope and you'd die. But this case most likely took years and years to develop, giving the brain ample time to adjust and rewire essential functions.
It's quite extraordinary if you ask me, showing off the power and adaptability of biological systems.
Reference: Brain of a white-collar worker
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