Since i don't know the options you have i'm just going to explain what non traumatic brain injury is.
When we call a brain injury traumatic it may include open head injuries(like a gunshot wound) or or closed head injuries (like blunt
trauma).
On the other hand, non-traumatic brain injuries may include those caused by strokes,
nontraumatic hemorrhage, tumor, infectious diseases, hypoxic injuries, toxic exposure blunt
trauma. Basically the non-traumatic injury doesn't depend of something outside the body.
