Can a doctor know if a patient has amnesia before they wake up?

If a patient is in a coma after a head injury, for example, if a boy fell from the second story of a house and was in a coma could the doctors be able to know if the boy had amnesia or is it like a wait and find out kind of thing? any information would help... Any website links? ThanksCan a doctor know if a patient has amnesia before they wake up?
Not really. They can make an educated guess. To do this, they can take an MRI of the brain to see what extent of damage has been done to the brain and how much is recovering. But they have no way of knowing what pathways hold what data, if any at all, nor which ones that aren't working because nothing is stimulating that part to work. Even with severe damage, a person could remember everything, and some people won't have any damage and remember nothing (this is mostly because they don't want to remember).