As a leading neurologist at the Hôpital de la Pitié in Paris, Joseph Babinski was used to seeing all sorts of unusual phenomena. But in 1914, two patients stuck out. Both had damage to the right hemispheres of their brains, leaving them paralysed on the left side of their body (each brain hemisphere controls the opposite side of the body).
For an experienced neurologist like Babinski, this was hardly noteworthy. What did strike him was that both patients insisted they were completely normal. They were unaware that there was anything wrong with them. In a 1914 medical journal article, Babinski explained that when he recommended electrotherapy to one of these patients, she replied, “Why do you want to electrify me? I am not paralysed.” He coined a new word to describe this symptom: anosognosia, literally meaning ‘without knowledge’.