As it turns out maybe the Scarecrow didn't need that brain after all. Real Clear Science revisits a bizarre case from 2007 in which a relatively normal 44-year-old man—married, two kids, job—turned out to have been going about his life without most of his brain. In fact, the discovery was only made when the man went to a hospital in France because his leg was feeling weak. According to a New Scientist article published when the case was revealed in July 2007, one neurologist estimated the man was missing more than 50% to 75% of his brain but—other than a slightly below-average IQ of 75, per the study in the Lancet—was suffering no ill effects. Real Clear Science reports the man's condition stemmed from a case of hydrocephalus (an excessive buildup the cerebrospinal fluid that cushions your brain) suffered as a baby.
At that time, doctors inserted a shunt into the man's skull to drain the fluid. But when the shunt was removed at age 14, fluid again started building up, and this time it had three decades to push his brain matter until that matter only lined the edges of his skull (pictures here). According to the New Scientist, neurologists could not explain how the man could function while the parts of the brain that control motion, language, vision, emotions, and more were severely compressed. In the end, the case was pointed to as an extreme example of the brain's adaptability. "If something happens very slowly over quite some time, maybe over decades, the different parts of the brain take up functions that would normally be done by the part that is pushed to the side," said a brain defect specialist not involved in the study. (On the subject of brains, a neurosurgeon may have helped bring down Napoleon.)