A large study in older veterans raises fresh concern about mild brain injuries that hundreds of thousands of troops have suffered from explosions in recent wars.
Even concussions seem to raise the risk of developing Alzheimer's disease or other dementia later in life, researchers found.
Records showed that 4,902 of the veterans had suffered a traumatic brain injury, or TBI, ranging from concussions to skull fractures. Researchers don't know how long ago the injuries occurred. Many participants were Vietnam War vets and their injuries were during active duty. None were due to strokes — those cases were weeded out.