title: Low clinical diagnostic accuracy of early vs advanced Parkinson disease: clinicopathologic study.
abstract: OBJECTIVE
  Determine diagnostic accuracy of a clinical diagnosis of Parkinson disease (PD) using neuropathologic diagnosis as the gold standard.
  
  
  METHODS
  Data from the Arizona Study of Aging and Neurodegenerative Disorders were used to determine the predictive value of a clinical PD diagnosis, using 2 clinical diagnostic confidence levels, PossPD (never treated or not clearly responsive) and ProbPD (responsive to medications). Neuropathologic diagnosis was the gold standard.
  
  
  RESULTS
  Based on first visit, 9 of 34 (26%) PossPD cases had neuropathologically confirmed PD while 80 of 97 (82%) ProbPD cases had confirmed PD. PD was confirmed in 8 of 15 (53%) ProbPD cases with <5 years of disease duration and 72 of 82 (88%) with ≥5 years of disease duration. Using final diagnosis at time of death, 91 of 107 (85%) ProbPD cases had confirmed PD. Clinical variables that improved diagnostic accuracy were medication response, motor fluctuations, dyskinesias, and hyposmia.
  
  
  CONCLUSIONS
  Using neuropathologic findings of PD as the gold standard, this study establishes the novel findings of only 26% accuracy for a clinical diagnosis of PD in untreated or not clearly responsive subjects, 53% accuracy in early PD responsive to medication (<5 years' duration), and >85% diagnostic accuracy of longer duration, medication-responsive PD. Caution is needed when interpreting clinical studies of PD, especially studies of early disease that do not have autopsy confirmation. The need for a tissue or other diagnostic biomarker is reinforced.
  
  
  METHODS
  This study provides Class II evidence that a clinical diagnosis of PD identifies patients who will have pathologically confirmed PD with a sensitivity of 88% and specificity of 68%.
authors: From the Parkinson's Disease and Movement Disorders Center, Department of Neurology (C.H.A., J.N.C., E.D.-D.), and Department of Biostatistics (J.G.H.), Mayo Clinic, Scottsdale; Civin Laboratory for Neuropathology (T.G.B., L.I.S., B.N.D.) and Cleo Roberts Center (H.A.S., M.N.S., S.A.J., C.M.B.), Banner Sun Health Research Institute, Sun City, AZ; and University of Arizona College of Medicine (H.A.S., M.N.S., S.A.J.), Phoenix. cadler@mayo.edu.
authors: Charles H
authors: CH
authors: Adler
authors: From the Parkinson's Disease and Movement Disorders Center, Department of Neurology (C.H.A., J.N.C., E.D.-D.), and Department of Biostatistics (J.G.H.), Mayo Clinic, Scottsdale; Civin Laboratory for Neuropathology (T.G.B., L.I.S., B.N.D.) and Cleo Roberts Center (H.A.S., M.N.S., S.A.J., C.M.B.), Banner Sun Health Research Institute, Sun City, AZ; and University of Arizona College of Medicine (H.A.S., M.N.S., S.A.J.), Phoenix.
authors: Thomas G
authors: TG
authors: Beach
authors: From the Parkinson's Disease and Movement Disorders Center, Department of Neurology (C.H.A., J.N.C., E.D.-D.), and Department of Biostatistics (J.G.H.), Mayo Clinic, Scottsdale; Civin Laboratory for Neuropathology (T.G.B., L.I.S., B.N.D.) and Cleo Roberts Center (H.A.S., M.N.S., S.A.J., C.M.B.), Banner Sun Health Research Institute, Sun City, AZ; and University of Arizona College of Medicine (H.A.S., M.N.S., S.A.J.), Phoenix.
authors: Joseph G
authors: JG
authors: Hentz
authors: From the Parkinson's Disease and Movement Disorders Center, Department of Neurology (C.H.A., J.N.C., E.D.-D.), and Department of Biostatistics (J.G.H.), Mayo Clinic, Scottsdale; Civin Laboratory for Neuropathology (T.G.B., L.I.S., B.N.D.) and Cleo Roberts Center (H.A.S., M.N.S., S.A.J., C.M.B.), Banner Sun Health Research Institute, Sun City, AZ; and University of Arizona College of Medicine (H.A.S., M.N.S., S.A.J.), Phoenix.
authors: Holly A
authors: HA
authors: Shill
authors: From the Parkinson's Disease and Movement Disorders Center, Department of Neurology (C.H.A., J.N.C., E.D.-D.), and Department of Biostatistics (J.G.H.), Mayo Clinic, Scottsdale; Civin Laboratory for Neuropathology (T.G.B., L.I.S., B.N.D.) and Cleo Roberts Center (H.A.S., M.N.S., S.A.J., C.M.B.), Banner Sun Health Research Institute, Sun City, AZ; and University of Arizona College of Medicine (H.A.S., M.N.S., S.A.J.), Phoenix.
authors: John N
authors: JN
authors: Caviness
authors: From the Parkinson's Disease and Movement Disorders Center, Department of Neurology (C.H.A., J.N.C., E.D.-D.), and Department of Biostatistics (J.G.H.), Mayo Clinic, Scottsdale; Civin Laboratory for Neuropathology (T.G.B., L.I.S., B.N.D.) and Cleo Roberts Center (H.A.S., M.N.S., S.A.J., C.M.B.), Banner Sun Health Research Institute, Sun City, AZ; and University of Arizona College of Medicine (H.A.S., M.N.S., S.A.J.), Phoenix.
authors: Erika
authors: E
authors: Driver-Dunckley
authors: From the Parkinson's Disease and Movement Disorders Center, Department of Neurology (C.H.A., J.N.C., E.D.-D.), and Department of Biostatistics (J.G.H.), Mayo Clinic, Scottsdale; Civin Laboratory for Neuropathology (T.G.B., L.I.S., B.N.D.) and Cleo Roberts Center (H.A.S., M.N.S., S.A.J., C.M.B.), Banner Sun Health Research Institute, Sun City, AZ; and University of Arizona College of Medicine (H.A.S., M.N.S., S.A.J.), Phoenix.
authors: Marwan N
authors: MN
authors: Sabbagh
authors: From the Parkinson's Disease and Movement Disorders Center, Department of Neurology (C.H.A., J.N.C., E.D.-D.), and Department of Biostatistics (J.G.H.), Mayo Clinic, Scottsdale; Civin Laboratory for Neuropathology (T.G.B., L.I.S., B.N.D.) and Cleo Roberts Center (H.A.S., M.N.S., S.A.J., C.M.B.), Banner Sun Health Research Institute, Sun City, AZ; and University of Arizona College of Medicine (H.A.S., M.N.S., S.A.J.), Phoenix.
authors: Lucia I
authors: LI
authors: Sue
authors: From the Parkinson's Disease and Movement Disorders Center, Department of Neurology (C.H.A., J.N.C., E.D.-D.), and Department of Biostatistics (J.G.H.), Mayo Clinic, Scottsdale; Civin Laboratory for Neuropathology (T.G.B., L.I.S., B.N.D.) and Cleo Roberts Center (H.A.S., M.N.S., S.A.J., C.M.B.), Banner Sun Health Research Institute, Sun City, AZ; and University of Arizona College of Medicine (H.A.S., M.N.S., S.A.J.), Phoenix.
authors: Sandra A
authors: SA
authors: Jacobson
authors: From the Parkinson's Disease and Movement Disorders Center, Department of Neurology (C.H.A., J.N.C., E.D.-D.), and Department of Biostatistics (J.G.H.), Mayo Clinic, Scottsdale; Civin Laboratory for Neuropathology (T.G.B., L.I.S., B.N.D.) and Cleo Roberts Center (H.A.S., M.N.S., S.A.J., C.M.B.), Banner Sun Health Research Institute, Sun City, AZ; and University of Arizona College of Medicine (H.A.S., M.N.S., S.A.J.), Phoenix.
authors: Christine M
authors: CM
authors: Belden
authors: From the Parkinson's Disease and Movement Disorders Center, Department of Neurology (C.H.A., J.N.C., E.D.-D.), and Department of Biostatistics (J.G.H.), Mayo Clinic, Scottsdale; Civin Laboratory for Neuropathology (T.G.B., L.I.S., B.N.D.) and Cleo Roberts Center (H.A.S., M.N.S., S.A.J., C.M.B.), Banner Sun Health Research Institute, Sun City, AZ; and University of Arizona College of Medicine (H.A.S., M.N.S., S.A.J.), Phoenix.
authors: Brittany N
authors: BN
authors: Dugger
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D003943:Diagnostic Techniques, Neurological / Q000592:standards*; D018450:Disease Progression; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology*; D011237:Predictive Value of Tests