... a subdural hematoma (there's got to be at least one in every medical drama)
... someone violently shaking an unconscious person who's just been in a terrible accident, and yelling at them, "Get a hold of yourself!"
A- They're unconscious. They can't hear you...
B- If they had a snowball's chance in hell of recovering without brain damage or not being paralyzed for life, you just snuffed that out by violently shaking them!