It’s always best to rule out anything else.
Don’t assume that because you pay privately, you get better quality because, that hasn’t been my experience with regards to neurologists. There has been a shortfall of neurologists in the UK over the years and at one point, psychiatrists were encouraged to fill that gap. Now, don’t get me wrong, there are one or two good psychiatrists BUT there are also some weird ones! These don’t look for the obvious physical cause, they prefer to think airy-fairy, if you get my meaning and treat you like a nut-case.
You also need to know that Dr Diana’s findings/theory, is not common knowledge.
My experience has been that there are good radiologists both inside and outside the NHS but, as with anything, it depends what they have been taught and what they’ve experienced, so again it could be pot-luck. The only benefit otherwise, from going private, is that you may get seen sooner.