Glimpsed at last – the life of neuropsychology’s most important patient

Monsieur Leborgne, nicknamed Tan Tan, for that was the only syllable he could utter (save for a swear word or two), died in the care of the neurologist Paul Broca in Paris on April 17, 1861. Arguably the most important case in the history of neuropsychology, Leborgne's death coincided with a debate raging in scholarly circles about the location of language function in the brain. When Broca autopsied Leborgne's brain, he observed a malformation on the left frontal lobe – "Broca's area" – and concluded this was the site of speech production, a moment that the historian Stanley Finger has described as a "key turning point in the history of the brain sciences".

Broca was far from being the first person to propose that speech function is located in the frontal lobes, but crucially, the evidence from Leborgne helped him persuade the academic community. For centuries experts had believed mental functions were located in the brain's hollows; that the cortex ("husk" in Latin) was little more than a rind of tissue and blood vessels. Today, problems producing language are still termed Broca's aphasia in recognition of Broca's landmark contribution, although Broca in fact named Leborgne's problems aphémie (meaning "without speech"). The Greek term "aphasia" (also meaning "speechlessness"), adopted by medicine, was coined in Broca's day by the physician Armand Trousseau.

In terms of the historical record, Leborgne is like a mirror opposite of Phineas Gage – another of neuropsychology's legendary cases. The story of Gage's life and infamous accident, in which a tamping iron shot through his brain, has been researched in-depth, inspiring books, poems, YouTube skits and snowmen makers along the way. Yet relatively little is known about the brain damage Gage suffered because no autopsy was performed when he died and his brain was never preserved (that hasn't stopped scientists from attempting to simulate the likely damage).

In contrast, Broca was careful to save Leborgne's brain for posterity. He decided against a full dissection, performing a surface examination only. Today the preserved organ is housed at the Musée Dupuytren museum in Paris, where Broca placed it. The brain has been scanned numerous times using modern methods (e.g. PDF), allowing detailed analysis of the location and nature of any lesions. We now know that the frontal lobe damage to Leborgne's brain was more extensive and deeper than Broca had realised based on his superficial examinations. But, contra the situation with Gage, while we are well-informed about Leborgne's brain, before now his identity and life story have remained largely mysterious. Broca's medical notes revealed little.

Thankfully, in a new paper, Cezary Domanski at Maria Curie-Sklodowska University in Poland has used archive registers in France to uncover hitherto unknown detailed biographical information about Monsieur Leborgne. Born in Moret-sur-Loing – the picturesque town that inspired Monet and other impressionists – "Tan's" full name was Louis Victor Leborgne. He was the son of Pierre Christophe Leborgne, a school teacher, and Margueritte Savard. He had three older siblings, Lucille, Pierre and Anne, and two younger siblings, Arsene and Louise.

An epileptic since his youth, it was Leborgne's loss of speech that led to him being hospitalised at age 30. Unmarried, he ended up spending the remaining 21 years of his life in hospital. Before this incapacitation through illness, Domanski tells us Leborgne was a "formier" in Paris, a kind of skilled craftsman who made the wooden forms used by shoemakers in their work.  Together with the information on Leborgne's family, this news corrects at least one historical myth. The oft-told idea that Leborgne "was an uneducated illiterate from the lower social class should once and for all be deemed erroneous," writes Domanski.

Based on his inquiries, the Polish historian offers an intriguing speculation – given that Leborgne's birthplace of Moret was home to several tanneries, Domanski wonders if his repeated utterance of Tan was somehow connected to childhood memories of the pretty town.

"One thing remains certain," Domanski concludes, "The memory of the disease and cause of death of 'Monsieur Leborgne' proved far more enduring than the story of his life, which was deemed irrelevant even when the patient was still alive. It is time for Louis Victor Leborgne to regain his identity …".

In 2009, out of the blue, a photograph was discovered of Phineas Gage. I wonder if we will ever look upon an image of Leborgne?

Further reading

Domanski CW (2013). Mysterious "Monsieur Leborgne": The Mystery of the Famous Patient in the History of Neuropsychology is Explained. Journal of the history of the neurosciences, 22 (1), 47-52 PMID: 23323531