@AlertCat
How common is it for someone to fake a neurological condition? How difficult are they normally to come up with a differential diagnosis?
No idea whether it's common to try and fake a neurological condition - but as I understand it, the rare Parkinsonism neurodegenerative diseases (there are several including CBD) are diagnosed through a process of elimination. A patient will present initially with what appears to be Parkinson's symptoms, and if they don't respond to treatment, or deteriorate rapidly in motor function, capability etc, more, different, tests are done and ultimately a diagnosis delivered, even if couched as "you probably have X".
It might be possible to fake the early symptoms, if one were so inclined. It would be impossible to fake what happens when these diseases accelerate, or to fake the way in which a patient deteriorates ( steady state perhaps for a few months and then a rapid permanent loss of some function(s), steady state at this level for a while then further rapid deterioration.)
I've read up widely about one of the Parkinsonism rare diseases and have never heard of someone with a confirmed diagnosis either living for years at mild-impairment level, or experiencing a reversal of symptoms. For people with neurodegenerative diseases, "Walking Back to Happiness" is just a song. If a patient has got to 12 years and counting after a "diagnosis" and is still living a full life, a reputable Consultant (who will/should see them regularly) would have retested and rediagnosed. Or, as another poster pointed out, have been working closely (daily) with said patient, salivating at the thought of making their name and medical history by demonstrating how neurodegenerative syndromes can be "cured".
And no letter of diagnosis from 2013 has been produced by the Walkers.