title: Changing the research criteria for the diagnosis of Parkinson's disease: obstacles and opportunities.
abstract: Recent findings question our present understanding of Parkinson's disease and suggest that new research criteria for the diagnosis of Parkinson's disease are needed, similar to those recently defined in Alzheimer's disease. However, our ability to redefine Parkinson's disease is hampered by its complexity and heterogeneity in genetics, phenotypes, and underlying molecular mechanisms; the absence of biochemical markers or ability to image Parkinson's disease-specific histopathological changes; the long prodromal period during which non-motor manifestations might precede classic motor manifestations; and uncertainty about the status of disorders diagnosed clinically as Parkinson's disease but without Lewy pathology. Although it is too early to confidently redefine Parkinson's disease, the time has come to establish a research framework that could lead to new diagnostic criteria. We propose the establishment of three tiers encompassing clinical features, pathological findings, and genetics or molecular mechanisms. Specific advances in each tier, bridged by neuroimaging and biochemical data, will eventually lead to a redefinition of Parkinson's disease.
authors.affiliation: Department of Neurodegeneration, Hertie-Institute of Clinical Brain Research, University of Tübingen, 72070 Tübingen, Germany. daniela.berg@uni-tuebingen.de
authors.forename: Daniela
authors.initials: D
authors.lastname: Berg
authors.forename: Anthony E
authors.initials: AE
authors.lastname: Lang
authors.forename: Ronald B
authors.initials: RB
authors.lastname: Postuma
authors.forename: Walter
authors.initials: W
authors.lastname: Maetzler
authors.forename: Guenther
authors.initials: G
authors.lastname: Deuschl
authors.forename: Thomas
authors.initials: T
authors.lastname: Gasser
authors.forename: Andrew
authors.initials: A
authors.lastname: Siderowf
authors.forename: Anthony H
authors.initials: AH
authors.lastname: Schapira
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Oertel
authors.forename: José A
authors.initials: JA
authors.lastname: Obeso
authors.forename: C Warren
authors.initials: CW
authors.lastname: Olanow
authors.forename: Werner
authors.initials: W
authors.lastname: Poewe
authors.forename: Matthew
authors.initials: M
authors.lastname: Stern
mesh_terms: D006801:Humans; D010300:Parkinson Disease / Q000175:diagnosis* / Q000473:pathology; D012106:Research