How One Mysterious Medical Case Helped Map the Brain

On April 11, 1861, Dr. Pierre Paul Broca examined a man in the surgical wing of the Bicêtre hospital near Paris. The 51-year-old patient 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.

The man’s name was Louis Victor Leborgne, but everyone called him Tan. He had been admitted to the hospital at age 30 after losing the ability to speak. Ten years later, he also started to lose the ability to use the limbs on his right side. This led to the gangrene, which landed him in Broca’s care.

The doctor considered the best treatment, mulling over Leborgne’s language problem. Broca had recently attended a scientific meeting where the topic was whether intellectual functions like language could be traced to specific locations in the brain. Another doctor there was convinced that the brain’s frontal lobes handled speech. He’d issued a challenge: If anyone found a case in which speech faltered but comprehension and other forms of communication functioned, and no lesion in the frontal lobes was found, he would renounce his position.

In light of the challenge, Broca took special care to determine whether Leborgne was mentally impaired generally, or if the problem was limited to language. The next day, he asked Tan how long he had been there and got the same answer as usual. The third day, he asked again. Leborgne had had enough, and uttered the only other phrase he seemed capable of producing when angry or frustrated: “Sacré nom de Dieu!” (“Goddammit!”).

A few days later, Leborgne died and Broca performed an autopsy on his body. The patient’s brain contained a wide area of fluid-filled decay, but by carefully inspecting the tissue at different locations, Broca deduced that a lesion had originally occurred in the second or third fold of the left frontal lobe and then slowly progressed outward, causing Leborgne’s symptoms. The language problem had come before his other impairments, and it had started in the left frontal lobe. Speech, it seemed, was located there. Broca presented Leborgne’s brain and explained his findings at a meeting with his scientific colleagues.

Six months later, Broca silenced any remaining skeptics. He was called in to see an 84-year-old man with a broken leg who had, months earlier, lost the ability to speak but not the ability to understand. He could say a handful of words, including “lelo” for his name, Lelong. When he died 12 days later, Broca found a lesion in his brain in the exact same place as Leborgne’s. A new era of brain research was born, and scientists began mapping brain functions.

The affected area, in the lower part of the left frontal gyrus, is now known as Broca’s Area. These days, if a patient suddenly loses language, doctors know to check there for a brain injury. The brains of Leborgne and Lelong were preserved and can still be seen at the Musée Dupuytren, a museum of medical curiosities in Paris, where their importance speaks for itself.