Yes, it is possible to measure the severity of a brain injury. There are three categories, mild, moderate and severe. It would have to be a medical professional that made the determination, of course, but things they would look at would be whether you were unconscious, if you were for what period of time. The longer you’re unconscious, the worse the injury. Did you have amnesia? For what period of time? Was it just momentarily or for a few hours? Is it for weeks or months? The longer, of course, the worse it would be, but they can definitely measure the level of severity.