Every case is different , but Parkinson’s is often associated with severe dementia that can manifest fairly quickly. I saw this happen to a close family member unfortunately.
My friend's grandmother's hand started shaking badly eating soup and she got bedridden due to a fall in their home, 1 year later she started calling her daughter "nurse" because she didn't recognize her and passed away not too long after due to heart failure.
I really hope they will find a treatment to this disease eventually.