Bob,

Most likely you have damaged your vestibular - visual - cerebellum systems. These all work in concert to tell your brain and body where it is at all times in the universe. When this gets disrupted, your brain has no idea what is going on when you are moving. So, a small jostle to your head or extremely light bump will set off symptoms because your brain has no way of gauging the severity of the jostle or bump - it thinks that all movement is severe and sets off the inflammatory cascade. Depending on how much damage was done, you can actually rehab this. I am currently undergoing vestibular/cerebellum rehab for this where I have to slowly desensitize my brain back to "normal." It is a very slow and somewhat painful process since it sets off symptoms every time I do it, but so far I have seen improvements. If interested in doing this therapy, google search: "vestibular rehab, brain injury" and you'll find someone in your area to go to. You really don't need to go to an E.N.T. first because a lot of physical therapists now have doctorate degrees and can prescribe therapy. This will save you some money going this way.