Many thanks for everyone's thoughtful comments.

I saw my Parkinson's doc today. He says levodopa did not help reduce my PD symptoms because i was never able to tolerate more than small doses. The side effects ruled out that I could get a dose large enough to be effective.

Rasagaline seems to have helped. I had a few of my lowest fatigue, least stiff days starting 3-4 weeks after beginning rasagiline. He says this demonstrates that I would benefit from more levodopa, the problem is how to get it onto my brain. Rasagiline seems to have helped, but the effect is not consistent day to day.

It feels to me as if rasagaline allowed my body to spare enough dopamine so that I can have a few more "on" days than before. There is also the chance that the rasagiline my be more effective the longer I take it. My doc believes a drug like apomorphine could be helpful to me, as an infusion it would be delivered to my bloodstream for up to 16 hours daily. There may be side effects that make it impractical, but I won't know until I try it. It looks a little complicated to set up daily, but I really need something that works better than what I have tried so far.

He says, not to diminish my symptoms, but that my Parkinson's symptoms are relatively mild, although also intrusive enough to keep me from being active consistently day to day. My symptoms being mild was why he prescribed the DAT scan. He does not think I have symptoms that would justify diagnosing me with a Parkinson Plus illness.