title: Parkinson's disease is overdiagnosed clinically at baseline in diagnostically uncertain cases: a 3-year European multicenter study with repeat [123I]FP-CIT SPECT.
abstract: Overdiagnosis of Parkinson's disease (PD) is suggested by specialist review of community diagnosis, and in postmortem studies. In specialist centers 4 to 15% of patients entered into clinical trials as early PD do not have functional imaging support for a PD diagnosis. In a European multicenter, prospective, longitudinal study, we compared clinical diagnosis with functional SPECT imaging using [123I]FP-CIT (DaTSCAN, GE Healthcare). Repeat observations were performed over 3 years in patients with tremor and/or parkinsonism in whom there was initial diagnostic uncertainty between degenerative parkinsonism and nondegenerative tremor disorders. Video-recording of clinical features was scored independently of functional imaging results by two blinded clinicians at 36 months (= gold standard clinical diagnosis). Three readers, unaware of the clinical diagnosis, classified the images as normal or abnormal by visual inspection. The main endpoint was the sensitivity and specificity of SPECT imaging at baseline compared with the gold standard. In 99 patients completing the three serial assessments, on-site clinical diagnosis overdiagnosed degenerative parkinsonism at baseline in diagnostically uncertain cases compared with the gold standard clinical diagnosis (at 36 months), the latter giving a sensitivity of 93% and specificity of 46%. The corresponding baseline [123I]FP-CIT SPECT results showed a mean sensitivity of 78% and a specificity of 97%. Inter-reader agreement for rating scans as normal or abnormal was high (Cohen's kappa = 0.94-0.97).
authors.affiliation: Department of Neurology, Southern General Hospital,1345 Govan Road, Glasgow, Scotland G51 4TF, United Kingdom. v.marshall@clinmed.gla.ac.uk
authors.forename: Vicky L
authors.initials: VL
authors.lastname: Marshall
authors.forename: Cornelia B
authors.initials: CB
authors.lastname: Reininger
authors.forename: Moritz
authors.initials: M
authors.lastname: Marquardt
authors.forename: Jim
authors.initials: J
authors.lastname: Patterson
authors.forename: Donald M
authors.initials: DM
authors.lastname: Hadley
authors.forename: Wolfgang H
authors.initials: WH
authors.lastname: Oertel
authors.forename: Hani T S
authors.initials: HT
authors.lastname: Benamer
authors.forename: Paul
authors.initials: P
authors.lastname: Kemp
authors.forename: David
authors.initials: D
authors.lastname: Burn
authors.forename: Eduardo
authors.initials: E
authors.lastname: Tolosa
authors.forename: Jamie
authors.initials: J
authors.lastname: Kulisevsky
authors.forename: Luis
authors.initials: L
authors.lastname: Cunha
authors.forename: Durval
authors.initials: D
authors.lastname: Costa
authors.forename: Jan
authors.initials: J
authors.lastname: Booij
authors.forename: Klaus
authors.initials: K
authors.lastname: Tatsch
authors.forename: K Ray
authors.initials: KR
authors.lastname: Chaudhuri
authors.forename: Gudrun
authors.initials: G
authors.lastname: Ulm
authors.forename: Oliver
authors.initials: O
authors.lastname: Pogarell
authors.forename: Helmut
authors.initials: H
authors.lastname: Höffken
authors.forename: Anja
authors.initials: A
authors.lastname: Gerstner
authors.forename: Donald G
authors.initials: DG
authors.lastname: Grosset
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology; D010300:Parkinson Disease / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology; D012016:Reference Values; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014326:Tropanes
chemical_list: D007457:Iodine Radioisotopes; D014326:Tropanes; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane