How One Mysterious Medical Case Helped Map The Brain

On April 11, 1861, Dr. Pierre Broca examined a man in the surgical wing of the Bicêtre hospital near Paris. The 51-year-old patient, Louis Leborgne, had gangrene all along his right leg, his entire right side was paralyzed, and he was nearly blind.
When Broca asked about the origin of the man's illness, the patient answered, 'tan, tan,' with a wave of his left hand. It was the only thing he could say. Strangely, though, his mouth, tongue, and voice box were in working order. His hearing was good, and he understood what other people were saying. Doctor Broca wanted to find out what happened.