November 5, 2007: It appears that at least six percent of American Iraq and Afghanistan combat veterans have suffered TBI (traumatic brain injury), to the extent that they may have long term problems. Mild, and normally undetectable, cases of TBI are believed to be quite common for combat veterans. Mild TBI is also known as a concussion, and is more common because more troops are being exposed to roadside bombs. Most of these explosions do not cause any obvious injuries to troops, even though their vehicles may be damaged. Mild TBI has long been an area of research in sports medicine. Veterans hospitals have many cases of World War II, Korea and Vietnam vets eventually developing other problems because of long ago combat actions that left them with mild TBI. Any kind of explosion can cause mild TBI, and over a third of troops in combat get mild TBI. For most of them, there are no long term consequences.

But as with football or hockey players who have been knocked on the head one time too many, there is sometimes long term damage. Until the 1980s, there was no hard evidence that mild TBI had long term consequences. But research identified and verified that there were long term effects in some victims. Before that, all that was known about the problem were the many anecdotal stories about people "not being the same" after getting a concussion.

Changes over time can indicate the onset of long term problems with mild TBI. Troops departing for a combat zone, and returning, are now being tested. Knowing that a solider has mild TBI makes it possible to quickly treat any side effects, or conditions that will get worse over time. The long term effects include damage to hearing, eyesight, sense of smell and changes in personality. Improved diagnostic instruments and techniques are constantly being developed, and perfected with use in civilian hospitals. Thus the seeming explosion in TBI cases is only partially due to the widespread use of roadside bombs. A lot of it is just being able to detect injuries that have always been there as a result of combat, and were largely undetectable in the past.