Is there a link between brain injuries (TBI) and PTSD? Could (TBI) Traumatic brain injuries be linked to Post Traumatic stress syndrome (PTSD)? I know there is a lot of concern with veterans and PTSD, but I am more interested in all the other situations/civilian cases of PTSD. From what I have read, there are overlapping symptoms between PTSD and TBI? Is it possible for someone to have PTSD from damage to the brain and not from a specific event?
It is reported that mild traumatic brain injury does not produce Post-Traumatic Stress Disorder however, according to this report in the American Journal of Psychiatry, severe TBI could possibly lead to PTSD in approximately 27% of cases.  In this study of 96 patients  (77 men and 19 women), after 6 months following hospital discharge for severe traumatic brain injury, 27% of them suffered PTSD.  Out of these patients:


19% reported having intrusive memories,
23% reported having nightmares,
31% reported having a sense of reliving the trauma,
65% reported avoidance of thoughts,
65% reported avoidance of places; and
73% had signs of hypervigilance.


However one point of note that the report detailed was that 


  First, our patients were not selected consecutively, and their
  responses may not be representative of populations with severe
  traumatic brain injury. Second, we did not obtain neuropsychological
  information on each patient.


I must admit that when I was looking at the report, due to the high number reliving the trauma and avoiding certain places, I wondered whether the trauma leading to PTSD was actually the brain injury or if it was the traumatic effect of the event which led to the brain injury.

Another point of note is that it was also reported in a committee hearing in the U. S. House of Representatives, that people with TBI are more likely to develop PTSD than those who have not incurred a brain injury

Personally, from looking at these reports, I think the jury may be still out on this one.