PAF1 and Parkinson disease: In addition, we looked at the correlation between PD2 binding and UPDRS scores controlling for various PD medications taken by the patients using the Levodopa equivalent dose calculated according to Tomlinson et al. 15 After controlling for differences in Levodopa equivalent dose among the PD patients, the PD2 peptoid was still highly correlated with the UPDRS scores (UPDRS-III: P=0.002; r=0.446; and UPDRS Total: P=0.0001; r=0.457).