“At least 20,000 U.S. troops who were not classified as wounded during combat in Iraq and Afghanistan have been found with signs of brain injuries, according to military and veterans records compiled by USA TODAY. The data, provided by the Army, Navy and Department of Veterans Affairs, show that about five times as many troops sustained brain trauma as the 4,471 officially listed by the Pentagon through Sept. 30. These cases also are not reflected in the Pentagon’s official tally of wounded, which stands at 30,327.”