Throughout the 11 or 12 years it took to arrive at a diagnosis of my wife's condition, all sorts of possibilities were examined. Among the diseases mentioned were Lewy Bodies and Parkinson's although they, like all the others that had been mentioned, were finally ruled out and we were left with the diagnosis of last resort - Alzheimer's
The tilt which my wife sometimes has - it can be to the left, the right, backwards and sometimes all of these alternating every few days with 'normal' - was observed by the GP after a fall and he thought that this and some of her hand movements might indicate that she now also had Parkinson's or some Parkinson's-like symptoms (though he didn't exactly share this thought at the time). Anyway, we've ended up with an appointment tomorrow with a doctor who specialises in Parkinson's and apparently has a very good reputation.
The little ray of hope, I suppose, is that whereas the handful of dementia drugs are useless or worse for many people (including my wife) it seems that drugs used in the case of Parkinson's are capable of alleviating some of the physical symptoms quite significantly.
I will try and report any progress here as I'm pretty sure that this will be of interest to some readers.