The identity of a mysterious patient who helped scientists pinpoint the brain region responsible for language has been discovered, researchers report.
The new finding, detailed in the January issue of the Journal of the History of the Neurosciences, identifies the famous patient as Monsieur Louis Leborgne, a French craftsman who battled epilepsy his entire life.
In 1840, a wordless patient was admitted to the Bicêtre Hospital outside Paris for aphasia, or an inability to speak. He was essentially just kept there, slowly deteriorating. It wasn't until 1861 that the man, who came to be known as Monsieur Leborgne, or "Tan," for his only spoken word, came to the famous physician Paul Broca's ward at the hospital.
Shortly after the meeting, Leborgne died, and Broca performed his autopsy. During the autopsy, Broca found a lesion in a region of the brain tucked back and up behind the eyes.
After doing a detailed examination, Broca concluded that Tan's aphasia was caused by damage to this region, and that the particular brain region controlled speech. That region of the brain was later renamed Broca's area in honor of the doctor. [See Photos of Broca's Brain]
At the time, scientists were debating whether specific areas of the brain performed specific functions, or whether it was an undifferentiated lump that did one task, like the liver, said Marjorie Lorch, a neurolinguist at Birkbeck, University of London, who was not involved in the study.
"Tan was the first patient whose case proved that damage to a specific part of the brain causes specific speech disorders," said study author Cezary Domanski, a medical historian at the Maria Curie-Sklodowska University in Poland.
Yet Tan's identity remained shrouded in mystery. Most historians believed he was a poor, illiterate laborer, while others said he had gone mad from syphilis and that madness could explain his inability to speak. To discover just who he was, Domanski began to retrace the man's history.
"It was a challenge, for 150 years no one could even determine the name of the man —the same man whose brain is exhibited in a museum and shown in many books," Domanski wrote in an email.
But looking through the old medical records, he finally uncovered a death certificate for Louis Victor Leborgne, who was born in 1809 in Moret, France.
Domanski then used archival records to discover that Louis Leborgne was one of seven children of a teacher (his father) and his wife, and that his siblings were educated. He moved to Paris as a child.
Leborgne had apparently suffered epilepsy from childhood. But despite his seizures, he grew up to be a craftsman and a church keeper, and worked there until he was 30 years old, when he lost the ability to speak and was taken to the hospital. Epilepsy likely caused the damage that took away Leborgne's power of speech. [The 10 Greatest Mysteries of the Mind]
In the hospital, his condition worsened and he eventually became paralyzed and bedridden, and underwent surgery for gangrene. He was dying when Broca first encountered him.
The new discovery gives a very human identity to one of the medical textbooks' most famous cases, Lorch told LiveScience.
"Language, because it was viewed at that time in Europe as a God-given ability in humans, it was considered part of the soul and therefore not material," Lorch said. "This case was the case that really established the whole area of research on functional organization of the brain."