No. Parkinson’s disease does not increase the risk of a stroke, nor does it lead to more severe symptoms if a stroke occurs. Over time, Parkinson’s disease leads to lower blood pressure, and statistically there are fewer strokes among patients with (many years of) Parkinson’s disease.
There is a condition known as secondary Parkinsonism, which is caused by damage to the smallest blood vessels and leads to vascular Parkinsonism, with small lesions and minor strokes that gradually and progressively give rise to symptoms that may resemble aspects of Parkinson’s disease, but it is not an active disease process like that seen in Parkinson’s disease. Vascular Parkinsonism primarily causes difficulty walking but rarely tremors or arm symptoms./Håkan Widner