March 7, 2013 5:48 am Re-Examining Head Injuries Study finds repeat head injuries can trigger dangerous auto-immune response. Erika Edwards reports. US & World Videos 1:36 Arizona Senate repeals 1864 abortion ban 3:37 4.1-magnitude earthquake shakes Corona 1:40 Democrats say Big Oil misled public for decades about climate change 2:56 Police putting up barricades on UCLA campus after overnight brawl 4:00 Firecrackers thrown at pro-Palestinian encampment during protester clash at UCLA