@shashig I was tested in a dark room with flashing lights. If I remember correctly it recorded the movement of my eyes when the lights were flashing.
There was another test or two.

Maybe you should look for doctors who are not “experts” in well respected settings.
My opinion is that you are making these guys annoyed with you.
When we “jump” from doctor to doctor we are giving them a sign that we will do the same with them. They don’t want to be criticized and have your next doctor hear about it.
They all know each other.

If I remember right, you said you were in New York obviously you’ve been going to these hospitals there is there anyway you could check out a smaller practice or you don’t want a medium size practice out in the suburbs they have good doctors out there too. I’m from Long Island. If you can do that get out of the city and see if there’s anybody else over the rivers, you might find something that helps. But as I said, I had that test with the flashing lights and that is what you need to diagnose if you have Vestibular neuritis or not.