I am sorry to hear about this-my brother.
Parkinsons dieease is fucking hardcore. My father passed away from this last year. And it was a blessing for him to die. Because from the time he got it till the day he passed it away-it was complete hell for him.
Every year he kept getting worse till he was bed ridden. Then he had a heart attack.. We think he overdosed on his medication to kill himself.
I would suggest hanging with him as much as possible because it will only get worse.