The definitive answer on Concussions from Dr. Robert Cantu

Joseph Goodman, of the Miami Herald, has an insightful Q&A on concussions with the preeminent doctor and researcher on concussions, Dr. Robert Cantu. Highlights below:

Q&A with Dr. Robert Cantu:

OK, so we've established that there is pretty much no one else in this world that knows more about sports-related concussions than Dr. Cantu. With the introductions out of the way, here's a Q&A I had with Dr. Cantu on Monday morning. It should be noted that Dr. Cantu spoke in generalities on Monday as he is not familiar with Tebow's case, medical history or symptoms. Generally speaking, according to Dr. Cantu, Tebow will likely be able to return to the practice field after a week if he is asymptomatic in the next few days.

Q: What are the chances Tebow returns to the field after a week of rest?
A: The bottom line is, as I think you can appreciate, when you talk about concussion and recovery patterns and all that stuff, it's a bell-shaped curve and the majority of people return within a week, probably about 75 to 80 percent. But that's not everybody, and there is no way on Day One to know whether someone is going to clear and be in that 80 percent group or be in that 20 percent group where symptoms may go on and last more than a week or even weeks.

It's possible that Tim could be in the fortunate group and within another four or five days he's asymptomatic and it's also possible Tim could be in that group that he is still going to be symptomatic in four or five days. And if he's in that group it's not safe for him to practice much less even work out. He should be asymptomatic at rest before he's allowed to exert himself and see whether exertion produces symptoms.

Q: What is Tebow doing right now, in the next few days, to recover from his concussion?
A: Right now it's a cognitive rest period for Tim and a physical rest period, waiting for all of his symptoms to clear and his case, I think it was complicated by the fact that he was playing with the flu, and that's going to have to be sorted out -- whether any of his ongoing symptoms are flu-related or concussion related. So, it's going to be to a little more tricky.

Q: Is loss of consciousness an indication of a severe concussion?
A: Brief loss of consciousness -- and by brief I'm talking about seconds -- is really not correlated necessarily to a severe concussion. It's certainly a moderate concussion but it's not necessarily indicating his symptoms are going to last a long period of time or that he's going to be out a long period of time.

If you're unconscious for more than a minute, then that is a severe concussion and tends to be associated with a slow recovery.

Q: Did Tebow's preexisting illness have anything to do with his concussion?
A: It doesn't at all. It just means that you're going to have to be comfortable knowing which symptoms he may have now are flu related versus concussion related. Many of the 25 symptoms of concussion -- for instance headache, light-headedness -- are shared symptoms with many other medical conditions, too. It doesn't have to be related to a concussion if it happened right after head trauma. But if you already had some kind of medical condition going on, for instance if you had some kind of headache or light headedness before because you had the flu, then you're going to have to sort it out -- whether you think it's the flu or whether you think it's the concussion. It adds a little bit of complexity for the assessment to be properly done.

Q: What will UF's doctors be looking for in the next few days?
A: Most importantly you are looking for the symptoms to clear, those that are there. Before they totally clear, you're looking for them to get better. And that's the normal pattern. Those that are there will diminish in their intensity and go away. And that may happen within a day. That may happen within a number of days. It may take weeks. If it takes weeks, then he's going to be out a long time. That's probably unlikely for him because he's not had prior significant head injuries, so that's an optimistic thing for him compared to someone who has had a lot of concussions before.

Click here for the whole discussion.