Yeesh, I hope it's not that serious...remember, Hackett retired because of it though. I had a teacher in college who had vertigo and he sometimes missed months of class on end because he couldn't get out of bed. Don't know whatever happened to him or if there's even a way to "cure" it though. Good luck Alex.
My dad actually had vertigo a few years ago (5-7). He was so sick that he was not able to even sit up for long periods of time or focus at all. In the inner ear there is a liquid or something like that which controls all of your balance if it is out of whack there is not much you can do.
The fact that Kovalev can even skate is pretty impressive and would lead me to believe that it is not as bad as it could be.
IT's what you get when you do a poorly-timed interview in a Russian magazine, and then have to spin like crazy to control the damage after it leaks to the habarazzi hordes. And yes, it is career-threatening.