We have a good friend that has it. She is managing it with no prescription medication.

Her go to methods for controlling it are as follows.

Strict ketogenic diet. The natural ketones produced have made a major positive impact and are her single best improvement thing she did. 

Physical exercise. She does cross-fit a few times a week. High intensity (as high as she can tolerate). She says exercise is an essential part of her treatment.

Takes exogenous ketones to supplement her naturally produced ketones. 

Does cold plunge in an ice bath. She has one of those tubs made for it. She is in a tropical location year round. Fills the tub with water. Puts two ten pound bags of ice in and lets it cool the water. Immerses as much as she can. Then showers hot. Says that the cold plunge makes her muscles totally relaxed and for about 30 minutes or so has no muscle fatigue from the Parkinson's. She does this right before bed and says it lets her get to sleep and have a much better night of sleep.

Takes vitamin B in high doses. I think nicotinamide and TTFD (B1).

Her and her husband do a ton of research on the subject. She chose not to take the medication because all it does is mask the palsy symptoms. It does nothing for the actual disease. She said she could manage that part and did not want the side effects that come with the medication.

I think I put them in about the order of significance of improvement. The diet is a very main part. Parkinson's often suffer from severe sugar addiction. We had another friend, now deceased, that had Parkinson's bad and she always was craving sweets which was the worst thing for her. Get rid of the sugar and most carbohydrates and the brain can run mostly on fat via liver ketone production.

Here is one on the high dose B1 therapy.   https://www.youtube.com/watch?v=iu1vJ8eN8HM&t=1414s  #mce_temp_url#     

I am not a doctor and know about nothing about it. All I am doing is passing along what a very dear friend has been doing for the last 3-5 years to control hers. Unless you know the Parkinson's symptoms to watch for most people would not notice that she has Parkinson's because of what she does to manage it. She takes care of horses and rides regularly. This was from a condition her husband described as having to carry her to the bathroom. Pretty bad. She works at it, but she has kept it beaten back. She still scuba dives but pretty rarely and only in super mild conditions and with her husband right beside her. She is not letting the disease get the best of her, at least so far.