He is blind from birth and the Wikipedia reference-linkMRI came back normal. he is still unsteady on his feet though, so not really sure what has caused that - maybe something vestibular?

I asked a visiting neurologist what to expect about the BPPV and he said you would still get nystagmus etc as the test is one of the vestibulo-ocular reflex (or something like that), not the visual pathways.

As for the "would he experience vertigo" question, I don't know. I would have thought you need some visual input to get the spinning sensation, so maybe not. I had to explain claustrophobia to him when talking about the MRI, which was interesting.

I might see if I can do some vestibular testing on him tomorrow and see what happens....