The brain of former NFL star Junior Seau, who committed suicide last year, showed signs of the kind of neurodegenerative disease associated with repetitive head trauma. Elsa/Getty Images hide caption

toggle caption Elsa/Getty Images

Junior Seau, seen here playing for the New England Patriots toward the end of his career, suffered from a degenerative brain disease, scientists say. Otto Greule Jr./Getty Images hide caption

toggle caption Otto Greule Jr./Getty Images

Junior Seau, seen here playing for the New England Patriots toward the end of his career, suffered from a degenerative brain disease, scientists say. Otto Greule Jr./Getty Images hide caption

toggle caption Otto Greule Jr./Getty Images

Junior Seau in 2002, when he was with the San Diego Chargers. Stephen Dunn/Getty Images hide caption

toggle caption Stephen Dunn/Getty Images

Tom Goldman talks with David Greene

  • <iframe src="https://www.npr.org/player/embed/151920550/151924004" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">