Doctors in China recently discovered that a 24-year-old woman is living without a cerebellum. Her condition is only the ninth known case in the world, io9 reported on Thursday.
The cerebellum, nicknamed "the little brain," is a portion of the brain that is responsible for fine motor movements including balance, posture, motor learning (such as kicking a ball), and speech. Located at the base of the skull, the cerebellum is comprised of about half of all neurons in the brain, though it represents only 10% of the volume.
Losing partial function due to injury or disease isn't completely unprecedented, though lacking a cerebellum from birth is extraordinarily rare.
The woman's condition was found after she sought medical attention due to nausea and vertigo. CT scans and MRI images revealed the missing cerebellum, which completely explains why those symptoms would be present. It also explains why she wasn't able to speak until she was six years old and wasn't able to walk until age seven. She had never been able to play and jump like normal children due to this defect, IFL Science reported.
Unsurprisingly, the woman had never been able to walk steadily without support throughout her entire life.
While testing revealed that she was perfectly able to understand vocabulary, the missing cerebellum caused her to have trouble with pronunciation. Her voice trembles, she slurs her words and the doctors described her voice tone as "harsh." Even still, the physicians were amazed that her symptoms were more in line with a mild to moderate impairment, not a complete absence.
Because the condition is so rare, it isn't very well understood how it happens. While there are about 30 mutations associated with disorganized cerebella, complete absence of the structure is a bit tougher to pinpoint. The patient represents a very unique opportunity to study the effects of this disorder in a living adult.
Her condition was further described in the journal Brain.
