Brian that would really suck.
Alex, it's a fairly recently discovered thing in that CT scanners have only been able to scan fine enough in the last few years, seem's most experts are in the USA, it's a collapsing of the superior canal in the inner ear that causes all kinds of awful problems, surgery could result in deafness and I could lose my balance alltogether, at the moment I can usually manage it and so far I am still allowed to drive so I plan to leave it alone and see what happens, If you get a chance google SCDS or Superior semicurcular canal dehiscence syndrome, compared to some sufferers I consider myself incredibly fortunate, I have a wonderfully supportive wife and understanding kids, there's also a clip on you tube called Inside Todds Head that shows it pretty well.
Phill