It's not out of the blue usually. It normally happens when they exert their neck muscles. I don't know if it's nervous system, muscular system, or psychological that makes the wobble. But, just like that video you posted, instead of the spinner, turning his head around to look behind him, he turns his head upside down instead. And when he holds his head up, he sways/vibrates. So, basically, they won't just start swaying out of the blue like a siezure.

There's no "cure" or "prevention" for it other than - don't get a spider.