Answer: Lazare Lelong was the second patient with aphasia who led to Paul Broca’s theory that language centers of the brain are localized.
Paul Broca was a famous French physician who studied people with a speech disorder called aphasia. In particular, he is best known for his characterization of people with expressive aphasia, which is sometimes also called nonfluent aphasia or Broca’s aphasia. In people with expressive aphasia, they have their ability to comprehend language intact, and can understand questions that are asked of them. They are often unable to express their intended answer, however. It may appear that they are having a hard time responding to the prompts given to them. (Compare these deficits with a different language disorder, receptive aphasia, where a person has no difficulty in producing speech, but their speech is meaningless - they cannot respond appropriately to an interviewer, for example.)
When Paul Broca first met Lazare Lelong, he was an 84-year-old man being treated for dementia at a hospital in the suburbs of Paris. Broca immediately noticed his language deficit when asking him questions. Lelong was only able to say five words: yes, no, always, three (which he used for all numbers), and his name.
When Lelong died, Broca conducted an autopsy on his brain to try to understand if there was some dramatically changed structure in his brain that was the underlying cause of his aphasia. In doing so, Broca discovered that a particular region in the frontal lobe, particularly the posterior inferior frontal lobe, was damaged. This area corresponds to Brodmann areas 44 and 45.
The first and more famous person studied by Paul Broca with a similar degree of expressive aphasia was Louis Victor Leborgne, who became known around the hospital as “Patient Tan” due to his use of the word “tan” as the syllable that was used for communication. In conducting an autopsy of Leborgne’s, Lelong’s, and many other patients with aphasia, Broca concluded that this posterior inferior frontal lobe was an essential part of the brain for production of language. The area is sometimes also called “Broca’s Area.”