(From a note to a friend suffering from a mysterious and incurable vertigo and damn if the doctors could figure out why.)
A clean bill of health does not mean the problem could not be neurological. It might just mean that somewhere in your neuro network a few neurons, or maybe a mess of neurons, are out of whack. I found that studying neurology helped me to make it through the randomness of epilepsy, with all kinds of neurons out of whack, and see it as not so much a medical problem as an engineering one. Whenever the brain began perceiving things wrongly–as in your brain still being convinced you have a balance problem–I learned how to work with it and either correct my brain’s incorrect assumptions or work around them. Just coming up with fixes and work arounds. Thus I was able to function successfully (more or less) in a world full of normal brained people. The neurologist V.S. Ramachandran‘s wonderful (and wonderfully readable) book The Tell-Tale Brain, in particular, was a real help. Brain patients are always fascinating anyway, mistaking wives for hats and all, and Ramachandran has come up with some extraordinary fixes (a jerry rigged box full of mirrors, for instance) for his patients that oft times just got the brain’s sense of self (i.e., the parts of the brain that connects the mind with the body that holds it) to realize that it was actually the problem. More often than not looking at the carefully placed mirrors so that the brain could see the missing arm from the brain’s point of view (and not a mirrored reflection) cause the phantom pain to disappear instantly. Your phantom vertigo–caused either by a virus or statin drugs, both done with ages ago–might be like those who suffer phantom pain in a long lost arm or leg.
Incidentally, some of the exceptional skills and capacities your specific brain has–the way you can hear and transcribe vast orchestrations in your head perfectly, as if a symphony is playing in front of you–could actually be the root if the problem. You never know. But extraordinary cognitive abilities usually lead to unplanned difficulties at some point. Which is probably the reason that not everyone has those abilities–they have been selected against through natural selection. Genius does have its downside.