Marc Dax

Who was Marc Dax?

Marc Dax was a French neurologist, sometimes credited for discovering the link between neurological damage to the left hemisphere, right-sided hemiplegia, and a loss of the ability to produce speech. He submitted his discovery, based on the observations of three patients in Montpellier, to the French Academy of Sciences and two previous notes were published in 1836, 25 years before Paul Broca's more famous description. His papers were titled Observations tending to prove the constant coincidence of disturbances of speech with a lesion of the left hemisphere of the brain, and Lesions of the left half of the encephalon coincident with the forgetting of signs of thinking. He died one year later and thus his discovery remained obscure.

In 1863, Gustave Dax, the son of Marc Dax, published his father's work on the subject, two years after Paul Broca's presentation of the same phenomenon to Société d’Anthropologie. The publication included the 1836 memoir of Marc Dax, his deceased father, and additional clinical observations of his own on 140 patients.