From WWE.com:
WWE Superstar Alberto Del Rio suffered a concussion during a match with Sin Cara on the Dec. 9 edition of Raw, according to WWE physician Dr. Chris Amann.
After speaking with Del Rio following his match, it was determined that he suffered the injury as a result of a top-rope sunset flip powerbomb. Following some initial testing, Dr. Amann diagnosed Del Rio with a concussion and will be re-evaluating him tomorrow, as well as administering an ImPACT test to determine a timetable for the former World Heavyweight Champion’s recovery.
Stay with WWE.com for more on Del Rio’s condition.