I'm pretty sure I provided some the last time you asked this, several studies. "Serious head injuries" was very well defined as I recall. If I have some time and boredom I'll dig them up.

But before I do that, I'd like to pin down exactly where you stand on that question. I don't like doing general research on something I've already settled to my satisfaction, just on request from someone who doesn't have specific questions or a hypothesis.