This time in Mind-blowing Brain Cases: The Dizzy Mother
The human brain has been described as ‘the most complex thing we have yet discovered in the universe’. In this series neuroscientist Elisabeth Buhl Thubron takes a closer look at intriguing brain cases that revolutionised the field. Some led to new theories, others to popular brain myths or even more confusion.
Part 3: The woman with half a brain
Name: N/A (anonymous case study)
Age at discovery: 24 years old
Location: Shandong Province, China
Imagine you are riding a bike. The pedals keep you moving, the handlebars control your direction, and the brakes slow you down. Each bike part serves a unique, specific function. If the brakes on your bike stop working, one of your remaining bike parts won’t magically take over the brakes’ role. Fixing or replacing the brakes is the only option. Does the human brain also work like this?
Your adaptable, plastic brain
This is one of those ‘forget everything they taught you at school’ moments. Contrary to past beliefs, the human brain does not follow this ‘one function per part’ rule. If one brain region is damaged, it does not necessarily mean your brain has lost the ability to carry out that region’s job. There’s a buzzword for this phenomenon and it is also one of my favourites: “neuroplasticity”. I mentioned this in my previous article on Phineas Gage, the man with a hole in his head. It means that your brain is like plasticine, especially up until adolescence; it is able to lose and grow new brain cells as a response to negative and positive psychological experiences, respectively, and it can also recover from physical damage.
Half full, half empty?
Like many of us, a 24-year old Chinese woman led a normal, uneventful childhood and adolescence. She is now married and mother to a daughter. As a late walker and talker, her parents thought she was merely a late developer. They did not raise an eyebrow when her movements became somewhat uncoordinated and her mental abilities mildly impaired, as she was still able to do most things. Last year, however, she was admitted into hospital complaining of dizziness and nausea. CT, MRI and DTI scans revealed an entire brain region was missing: the cerebellum!
Your cerebellum, which means “little brain” in Latin, is found at the base of your brain, where the spinal cord and brain meet. It only makes up 10% of your total brain weight but it contains half of all your brain cells. The main job of the cerebellum is to coordinate your movements, control balance and regulate important cognitive functions such as speech. Scientists believe it is involved in many other functions, but the specifications are still unclear. Nevertheless, surely missing half of your brain should not be compatible with life?
Making up for lost functions
There have only been 9 reported cases of cerebellar agenesis, and most were discovered after premature death. These predominantly included children with severe mental impairments and epilepsy. The leading scientist, Feng Yu, and his colleagues from the Department of Neurosurgery in Shandong Province’s Chinese PLA General Hospital of Jinan Military Area Command wrote that the mild symptoms experienced by the young woman, far less than expected, supports the concept that compensatory neuroplasticity in a neighboring region took place early in her development. It is similar to the principle behind blindness leading to heightened hearing.
Few adult cases of cerebellar agenesis have been studied, with details also lacking, so this new case will provide scientists and clinicians the opportunity to study the cerebellum and neuroplasticity in greater depth. This is yet another example of how little we know about the brain, and how individual mind-blowing case studies like this one can over-turn long-held scientific beliefs. The further we search, the more mesmerizing the brain becomes!
Your brain is able to adapt, for better or worse, so take care of it, and it will take care of you. And that’s a no-brainer.
Yu, F., Jiang, Q., Sun, X., & Zhang, R. (2014). A new case of complete primary cerebellar agenesis: clinical and imaging findings in a living patient Brain DOI: 10.1093/brain/awu239