The woman with a partial brain

Doctors find that a 24 year old woman in China has a chunk of her brain missing since birth

A 24-year-old woman in China's Shandong province checked herself into a hospital complaining of severe nausea, dizziness and an inability to maintain balance while walking. After taking MRI and CT scans of her brain, doctors found a part of it, the cerebellum, was missing. What’s more, it has been missing since birth. A case study published in the August 2014 issue of the Oxford journal Brain says this is only the ninth documented living case of a condition known as “primary cerebellar agenesis.”

The cerebellum is located at the back of the brain just above the brain stem and is said to contain about 50% of the brain’s neurons, a video on Slate shows. Writing in Wired Science, Christian Jarrett says it was earlier thought the cerebellum controlled functions related only to movement and balance, but researchers have discovered that it extends to emotion, language, memory and attention.

What makes the Chinese woman’s case exceptional is the rarity of her condition but also her brain’s neuroplasticity—the remarkable ability of the brain to adapt to neurological deficiencies. Symptoms of the condition manifested themselves in the 24 year old as mild intellectual impairments, delayed speech and movement – she was able to walk only after she turned seven, and experienced slurred speech till the age of six. She has also been unable to walk steadily for most of her adult life.

But there is a catch. “There is a significant difference between the brain adjusting developmentally to congenital or early acquired abnormalities, and its ability to adapt to problems encountered later in life,” Jarrett writes.

In another documented case, Jarrett describes a man whose missing cerebellum was reported only after his death at the age of 76. Researchers claimed that he had led a symptom-free life, but this could not be proved due to a lack of more information.

Similarly, not much is known about the Chinese case. Experts will need to conduct further tests to determine the extent to which the missing brain structure has affected her. Such research is also expected to shed light on the potentially diverse functions of the cerebellum. The study published in Brain states that because there are very few reported cases of the disorder, much of what is known is based on autopsy reports; indeed, little to no information is available on living people with the condition.

Despite the missing structure, the woman has been able to lead a normal life, even giving birth to a daughter. Jarrett, however, cautions that hyping such rare instances of brain injuries and/or disorders minimizes the painful experiences such persons undergo.