It involves alot: he just had a scan looking at ldopa in the brain, upcoming could be spinal tap, blood tests, and a skin punch. A participant can opt out at any time, and many medical centers are involved. This study started 12 years ago I believe. All costs are covered for the participant. Person will be followed for 5 years at least I think. My husband is participating just to aid science. The letters PPMI may be meaningful.