A 24-year-old woman has unknowingly lived without cerebellum in her brain. How is it even possible to have a normal life with part of one’s brain missing?
About a month ago, a woman walked into a hospital in China to get an examination, having grown concerned after a month of nausea and dizziness. When the doctors asked her about her medical history, she reported having had balance and motor difficulties throughout all her life. She didn’t begin to speak until the age of four and walk until the age of seven, and both those functions were slightly defective. Other than that, she had had a fairly normal life, a job, a marriage and a daughter and had graciously reached the age of 24.
Imagine her surprise when they told her part of her brain was not were it was supposed to be. And it wasn’t misplaced, either. It was simply…not there. Where her cerebellum was supposed to be was an empty space filled with cerebrospinal fluid.
The name of the condition is “complete primary cerebellar agenesis“, and there have been only nine recorded cases, including the young woman. As the name implies, the cerebellum doesn’t form when it is supposed to, and it so happens that it doesn’t develop at all.
Now, why is that so perplexing a case? Let’s take a look at what the cerebellum is and what part it plays in our brain functions. The word is derived from Latin, it is a diminutive form of the word “cerebrum”, and it is literally translated as “little brain“. The cerebellum is located at the lower part of the brain, near the beginning of the spine, and, small though it may be, it contains about 50% of our neurons. It is very important for motor control, motor learning, balance, and fine movement. An insane amount of signal transmission and synaptic activity takes place at the cerebellum; it is, in its own way, a pair of the brain, yet completely separate from it, so to speak. It even looks different; the structure is more dense, giving it a massive signal-processing capability.
Our next immediate question is: What does this mean?
Well, the most likely answer is that the brain is still widely undiscovered by scientists. The cases of the missing cerebellum are a testament to the brain’s plasticity and its ability to adapt to different situations. It is unknown how the brain retained motor functions without a cerebellum, and this woman’s normal previous life has confounded doctors. The only thing that is for certain is that the brain works in mysterious ways, and remains the most unexplained organ of the human body.