Greetings Everybody. I've read/heard references to "levels" of PD. (Grade or level 3, for example.) Are there national or international scales for this kinds of comparison? I imagine that they might be different for young-onset patients. Could anyone with further information about this please post it to the group. I realize that PD is different for everyone, but perhaps as we continue to compare treatments and resources it would be helpful to have a common language. Joanna