I carried on working for 7 years after diagnosis.. When I eventually went to my GP he did not question me but signed me off for a month and said he was surprised I continued working so long. Currently (10 months later) I am on a 3 month sick note. My consultant was also very supportive and said it was an individuall choice and would support the decision I made.
I found that I needed to take my first Stalevo at about 5 am so I was "on" to catch the 6:54 train. At lunch time I had already grazed my lunch and used to nap in my chair. I found that there were a number of people doing exactly the same. I was determined to continue working in order to not let PD defeat me, but changed my mind after being interviewed for a part-time job and realising there is life outside the office. Now I wonder why I waited so long.
You need to get a quote from your pensions department if you have fsp - or maybe an average sp, I have found my pensions people are only to glad to help. I get 2 estimates the early retirement and the medical early retirement.
Next is when you can start drawing your pension, and is there an advantage in drawing it early and late, and maybe how attractive is taking part of your pension pot as cash. I am personally putting money into AVCs which is tax free and which I intend to get back as cash when I draw my pension.
You also need to have an idea of your expenditure month to month or year year. This will be useful in comparing your monthly spend vs monthly pension. Separately there is the rainy day money for unexpected and regular one off costs, like new car or repairing damaged roof.
In my case my company gives me insurance for long term sickness called GIP. This pays a % of my salary whilst I am off sick. Otherwise being long term sick your pay will from to company sick pay and/or statutory sick pay. With GIP you can also claim ESA
Crunch those numbers !!