We have two active threads which describe very promising research results.

Forced exercise shows " ... blinded UPDRS-III [motor section] ratings improved by 35% from baseline to EOT for the FE group" [1].

Bio-feedback shows "37% improvement of the motor scale of the Unified Parkinson's Disease Rating Scale" [2].

I'm struck by the closeness (35% and 37%) of the results. This closeness is not statistically significant (about 1 in 20 pairs of integer values drawn randomly from the range 0 to 100 would be at least as close). But, nevertheless, it makes me think: is it coincidence?

Could it be that both approaches address the same underlying process?
Could it be that the UPDRS does not provide the necessary level of linear accuracy in this case?

[1] "It Is Not About the Bike, It Is About the Pedaling
Forced Exercise and Parkinson's Disease"
Jay L. Alberts; Susan M. Linder; Amanda L. Penko; Mark J. Lowe1; Micheal Phillips
Exerc Sport Sci Rev. 2011;39(4):177-186.
http://www.medscape.com/viewarticle/751998

[2] "Real-time functional magnetic resonance imaging neurofeedback for treatment of Parkinson's disease."
Subramanian L, Hindle JV, Johnston S, Roberts MV, Husain M, Goebel R, Linden D.
J Neurosci. 2011 Nov 9;31(45):16309-17.
(From abstract, http://www.ncbi.nlm.nih.gov/pubmed/22072682
the paper itself appears to be behind a pay wall.)

John