Hello
My granpa was recently diagnosed with Parkinson at the grand old age of 80 years old (we suspected it for a few years he had Parkinson but didnt want to be looked into - turned out he was scared that it meant drilling in his head 
).
Anyway since the diagnosis he has been followed by a Parkinson Consultant, a Parkinson Nurse and recently agreed to have interaction with the Parkinson Support Worker. But being stubborn as he is; he is in total denial about the whole diagnosis.
By that I mean that any forms I fill in on his behalf (due to his difficulties in writing); he kicks off at me claiming "Why did you put I have Parkinson? Its not been proven".
This is the patter he uses all the time with medical professional too "its not been proven" and I end up with the regular calls from his GP and Practise Nurse about his ongoing lack on understanding of the diagnosis
We have explained (including his Parkinson team) that they cannot prove it 100% without invasive surgery however they are 98% sure.
However every day I have to go through this explanation over and over again.
I recently found out that the reason for him believing "its not been proven" is because a letter he received a year ago clearing signs of strokes states "symptoms are most likely linked to a diagnosis of parkinsons".
Any ideas on how to get the message across or is it something I need to reside myself to have to go through day in and day out?
Thanks