Pentagon holds brain injury data The Pentagon is refusing to release data on how many soldiers have suffered brain injuries in Iraq and Afghanistan. It says disclosing the results would put the lives of those fighting at risk. The data come from screenings of 1,587 soldiers at Fort Bragg in North Carolina and 9,000 at Fort Carson in Colorado. Army Medical Command spokesman Jaime Cavazos said Wednesday that the results of the tests represent "information the enemy could use to potentially make soldiers more vulnerable to harm." He declined to elaborate. FROM MILD TO SEVERE: Brain injuries add up Pentagon scientists and other health officials have already made public similar data from other installations. Those results show that about 10% of combat troops — and 20% in front-line infantry units — suffered concussions during their tours. The injuries frequently go undiagnosed; multiple concussions can lead to permanent brain damage. The screening is done with a questionnaire prepared by the Defense and Veterans Brain Injury Center, a research arm of the Defense and Veterans Affairs departments. The questionnaire is used at four military bases, and center director Deborah Warden has urged that it be used throughout the military. So far, the Pentagon has declined to do so because it questions whether troops can accurately answer the questions in the screening. Naval Medical Center San Diego, which has been screening Marines from nearby Camp Pendleton for two years — and, more recently, soldiers from the Army's Fort Irwin — released data this week. Those data show that 10% of 7,909 Marines with the 1st Marine Division suffered brain injuries. Researchers tried to follow up with 500 Marines who suffered concussions. They reached 161 of them and found that 83% were still suffering symptoms on average 10 months after the injury. At Fort Irwin, 1,490 soldiers were screened, and almost 12% suffered concussions during their combat tours.