1.   He just delivered the elbow to the head of Willis, which caused the concussion, which caused him to miss two games.

2.   This fact hit LeBlanc hard enough to cause a concussion just last week.

3.   A key question is whether heading causes concussion.

4.   Concussions are caused when a blow rotates and twists the brain in the skull, damaging brain tissue.

5.   He hit his head hard enough to cause a concussion.

6.   Considered a non-lethal weapon, they can break bones and cause serious concussion but rarely cause death.