What caused Beau Biden's health scare?

(CNN) – Delaware Attorney General Beau Biden is alert and stable after suffering a mild stroke yesterday. The vice president's eldest son is talking and has all of his motor skills. Although he's expected to recover, he's staying under the watchful eye of doctors at a Philadelphia hospital. Our chief medical correspondent Dr. Sanjay Gupta … Continue reading What caused Beau Biden's health scare?