My son (11 y/o) fell in the shower and hit his forehead. He has a knot about the size of a small orange. He's able to follow my finger with his eyes, speak, walk and answer any question such as dates, names, addresses, etc. I've been icing the knot and gave him one alive and some Tylenol. Is he fine to go to sleep? And, how else can I determine if he's got a concussion?