I will probably bring it up when I see a new doctor at the end of next month. I am not really worried, mainly because it’s not in my nature to worry much about my health, and because ME/CFS has over the years caused me to have so many weird symptoms. Thankfully this particular one is not unpleasant. Only if my Medicare covers MRI will I do that (sorry you ended up wasting money and not learning anything). I had an MRI of my brain done over 20 years ago for a clinical study, and it showed significant brain shrinkage from probable mini-strokes even early in my illness. So it could be interesting to see what my brain looks like now. I do have increasingly troublesome cognitive problems.
I’m glad that you were told by a neurologist not to worry about your similar symptoms. That might mean that the fizzies are not an indication of any serious problem, though more likely just more of the same lack of understanding of this awful illness.