Here is link to one study

https://www.ncbi.nlm.nih.gov/pubmed/23160937

Several years ago while researching PD treatment I discovered that OHSU Parkinson Center used Ritalin in treatment of PD. https://search.yahoo.com/search?p=ritalin+ohsu+...
also Wikipedia mentions its use. https://en.wikipedia.org/wiki/Methylphenidate
I have been on methylphenid (generic Ritalin) since learning this. I find it valuable in fatigue reduction.

Remember talking in past. You strike me as one of my favorite LT's
I looked up the Ritalin and it seems to have good promise in helping Parkinsons. It helps increase dopamine absorption and levels out the on/off periods and also has been shown to help with gait.
The studies are preliminary and hopeful.

The Parkinson's team page also says it is your birthday so Happy 🎂

I’m tired also. I don’t think I’ll ever have
Normal energy again. Also. Have really become a real night owl. Trying to do better about this

also known as Ritalin and used (mostly children under 18) for ADD, ADHD, etc - typically acts as a stimulant in Adults, but never read about any linkage to PD, etc...keep on fighting the good fight John