You need to first ensure that the parkinsons medication is at an optimum post stroke. Perhaps put in some measures to look at the dose response in liaison with the treating physician.

Then treat them the same, albeit with perhaps more full and rotational movements rather than part practise which might be difficult. Time of day can also have an effect on the parkinson's patient so try a few different times for treatment sessions as well as asking the client and the family about the better time of the day in relation to function historically.