AUTHOR=Lerche Stefanie , Heinzel Sebastian , Alves Guido W. , Barone Paolo , Behnke Stefanie , Ben-Shlomo Yoav , Berendse Henk , Bloem Bastiaan R. , Burn David , Dodel Richard , Grosset Donald G. , Hipp Geraldine , Hu Michele T. , Kasten Meike , Krüger Rejko , Liepelt-Scarfone Inga , Maetzler Walter , Moccia Marcello , Mollenhauer Brit , Oertel Wolfgang , Roeben Benjamin , Walter Uwe , Wirdefeldt Karin , Berg Daniela TITLE=Aiming for Study Comparability in Parkinson's Disease: Proposal for a Modular Set of Biomarker Assessments to be Used in Longitudinal Studies JOURNAL=Frontiers in Aging Neuroscience VOLUME=8 YEAR=2016 URL=https://www.frontiersin.org/journals/aging-neuroscience/articles/10.3389/fnagi.2016.00121 DOI=10.3389/fnagi.2016.00121 ISSN=1663-4365