Via Crooks and Liars: USA Today reports:

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.

....Soldiers and Marines whose wounds were discovered after they left Iraq are not added to the official casualty list, says Army Col. Robert Labutta, a neurologist and brain injury consultant for the Pentagon. More than 150,000 troops may have suffered head injuries in combat, says Rep. Bill Pascrell, D-N.J., founder of the Congressional Brain Injury Task Force.

As Logan at C&L notes:

Hiding the true human cost of their wars has proven difficult for the Bush administration. They don’t want the world to know about the real numbers of injured — or the staggering number of homeless vets or those who have killed themselves during or after their service in Iraq and Afghanistan.