Study: Leonardo da Vinci suffered from “claw hand,” not post-stroke paralysis

Enlarge / Detail from a 16th century drawing depicting an elderly Leonardo da Vinci’s damaged right hand. A new study concludes he suffered from “claw hand.” (credit: Museum of Gallerie Dell’Accademia, Venice)

Famed artist and inventor Leonardo da Vinci suffered from a crippled right hand late in life, usually attributed to a stroke. In a new paper in the Journal of the Royal Society of Medicine, two Italian researchers argue that Leonardo more likely suffered from a condition colloquially known as “claw hand.” They base their argument on analysis of a 16th century portrait of en elderly Leonardo.

The quintessential Renaissance man was the illegitimate son of a Florentine notary named Piero Frusino di Antonio da Vinci. (His mother, Caterina, was a peasant.) Much of what we know about Leonardo’s life comes from the writing of the 16th century painter and historian Giorgio Vasari, in Lives of the Most Excellent Painters, Sculptors, and Architects.

Historians have also studied Leonardo’s drawings and his use of “mirror writing” in his journals, concluding he was almost certainly predominantly left-handed, although he was ambidextrous to come extent. For instance, he wrote and drew with his left hand, but never painted with it. Vasari noted that Leonardo in his prime “was physically so strong that … with his right hand he could bend the ring of an iron door knocker or a horseshoe as if they were lead.”