hi there, and yes some people get these tests done...are you going for a Sleep Study? where you sleep overnight at a hospital or medical clinic
?? is so, that is where they attach all the "things" on your head.. it doesn't hurt..
also, a VEP, they do something the same, but it doesn't take long and doesn't hurt.
they could be trying to rule out things as well as getting information to help get to a DX..
do you have Vertigo at all? If so, it could be for that?