Neurosurgeons reported in the Journal of Neurology the case of a 24-year-old woman who, after a series of brain scans to investigate dizziness, discovered she was born without a cerebellum. Located at the back of the brain, the cerebellum is estimated to contain half the neurons of the entire brain. Experts used to think the cerebellum was associated with only balance and coordination, but in the last decade or so scientists realized the cerebellum is also associated with attention, memory, language, and emotion.
According to Christian Jarrett who wrote an article for Wired, “This revolution in our understanding of the functions of the cerebellum makes it seem all the more remarkable that the woman in question has only just discovered her brain is completely absent this key structure. Certainly, adults who develop illnesses, or incur injuries, that affect the function of the cerebellum (such as cerebellar ataxia) usually suffer profound difficulties with movement, including being unable to stand or walk. Recently it’s also become apparent that they often have other mental impairments too, in line with the structure’s diverse functions.”
The woman with no cerebellum apparently started walking late in life, she has an unsteady gait, and slurred speech, but it is amazing she is able to walk or talk. Authors of the case study say she has mild intellectual impairment, but they also note that she is married with a daughter, and she has normal word comprehension.
The case mentioned in this post is extremely rare. As such, we cannot conclude the case applies to our situations, but the case gives us reason to question some of the beliefs about brain anatomy, memory, and neuroplasticity.