Table 3

Studies in the prediagnostic phase of Parkinson's disease

AcronymStudy nameParticipantsCountryNumber recruitedTests/exposuresOutcome
PRIPS57Prospective validation of risk factors for the development of Parkinson syndromesSubjects over 50 years oldGermany, Austria1847TCS, smell, UPDRSClinical diagnosis of PD
TREND58Tübinger evaluation of risk factors for the early detection of neurodegenerationSubjects over 50 years with anosmia, self-report RBD or depressionGermany>1200TCS, smell, UPDRS, quantitative motor, psychometry, blood biomarkersClinical diagnosis of PD
PARS43Parkinson's at-risk syndrom studySubjects over 50 years with hyposmia and DaT deficit on SPECTUSA4999 (completed baseline smell test)Smell, DaT SPECT, UPDRS, cognition, blood biomarkersClinical diagnosis of PD/DaT deficit on SPECT
P-PPMI41Prodromal Parkinson's Progression Markers InitiativeSubjects with prodromal features or gene mutationsInternationalAnosmia/RBD=65
CSF and blood biomarkers, UPDRS, cognition, sleep and autonomic assessmentsClinical diagnosis of PD
OPDC59Oxford Parkinson's Disease Centre studySubjects with a first-degree relative with PD, or subjects with RBD (PSG confirmed)UK∼190UPDRS, non-motor assessments, blood and CSF biomarkersClinical diagnosis of PD
PREDICT-PD60PREDICT-PDSubjects over 60 years oldUK1323In all (online): risk scoring, smell, RBDSQ, quantitative motor (BRAIN test), genetics
In extremes of risk: UPDRS, cognitive, TCS
Clinical diagnosis of PD/DaT deficit on SPECT
  • BRAIN test, BRadykinesia Akinesia INcoordination test; B-SIT, Brief Smell Identification Test; CSF, Cerebrospinal Fluid; DaT, Dopamine Transporter; PD, Parkinson's disease; PSG, polysomnography; RBD, REM sleep Behaviour Disorder; RBDSQ, RBD Screening Questionnaire; SPECT, single photon emission computed tomography; TCS, Transcranial Sonography; UPDRS, Unified Parkinson's Disease Rating Scale.