I really empathize with soldiers returning from Iraq because many of them unknowingly suffer from TBI. Symptoms of post-traumatic stress disorder, or PTSD, are similar to TBI symptoms (irritability, trouble sleeping, dizziness etc) so soldiers can be misdiagnosed.
"Diagnosing TBI is imprecise — damage rarely shows up on CAT scans or other tests. Treating it is a crapshoot, because little is known about the brain injuries from blasts in Iraq versus the ones from falls and car crashes that doctors are used to seeing".
Read the following article for more detail: http://www.msnbc.msn.com/id/20612615/