@ Ninja
While Mercury is afflicted in both Rasi and Navamsa, the afflictions are not strong in other charts like Drekkana, Trimsamsa etc.
You are running the dasa of Saturn and antara also of Saturn. In parallel, you are also having Sade sathi. Ketu with Sun also constitutes Pitru dosha. But there is no Parkinson’s disease.
Recite Hanuman Chalisa daily. Perform a Pitru dosha shanti at Rameshwaram in T.Nadu or Gokarna in Karnataka.