I've heard, or more probably read, it used to describe a series of jerky movements (here's one: "...
Mahler conducting as if he had St Vitus's dance...") but only in the sense of referring to the disease, not "Oh, that silly John's got St. Vitus' dance again."
And not the urgent need to pee thing, no.
Is it the old-fashioned name that makes it fair game for this kind of use? I cannot imagine anyone writing "...Mahler conducting as if he had Sydenham's chorea," at least not for publication.
[native speaker, not teacher]