I know about this. My Dad has it.
It's a inner ear thing that can cause you to have vertigo and possibly loss of hearing eventually. There isn't much in the way of research on it but they think it can be passed genetically. Which I believe now because my DSis had problems with vertigo start a few years ago and recently I have started having episodes.
It's like spinning around really fast (like when you are a kid) and then stop. Everything around you seems to be spinning. Only when you close your eyes the spinning doesn't stop. There isn't anything they can do for the vertigo but if you have a problem with nausea you can take some pills.
I have no idea what causes the episodes but for me they haven't lasted very long.
I found some great info on this disease at webmd.com.