title: Longitudinal study of normal cognition in Parkinson disease.
abstract: OBJECTIVE
  To report the rates and predictors of progression from normal cognition to either mild cognitive impairment (MCI) or dementia using standardized neuropsychological methods.
  
  
  METHODS
  A prospective cohort of patients diagnosed with Parkinson disease (PD) and baseline normal cognition was assessed for cognitive decline, performance, and function for a minimum of 2 years, and up to 6. A panel of movement disorders experts classified patients as having normal cognition, MCI, or dementia, with 55/68 (80.9%) of eligible patients seen at year 6. Kaplan-Meier curves and Cox proportional hazard models were used to examine cognitive decline and its predictors.
  
  
  RESULTS
  We enrolled 141 patients, who averaged 68.8 years of age, 63% men, who had PD on average for 5 years. The cumulative incidence of cognitive impairment was 8.5% at year 1, increasing to 47.4% by year 6. All incident MCI cases had progressed to dementia by year 5. In a multivariate analysis, predictors of future decline were male sex (p = 0.02), higher Unified Parkinson's Disease Rating Scale motor score (p ≤ 0.001), and worse global cognitive score (p < 0.001).
  
  
  CONCLUSIONS
  Approximately half of patients with PD with normal cognition at baseline develop cognitive impairment within 6 years and all new MCI cases progress to dementia within 5 years. Our results show that the transition from normal cognition to cognitive impairment, including dementia, occurs frequently and quickly. Certain clinical and cognitive variables may be useful in predicting progression to cognitive impairment in PD.
authors.affiliation: From the Departments of Neurology (K.P., J.R., H.H., A.C.-P., J.E.D., J.F.M., L.M.C., N.D., R.S.A., D.W.), Pathology and Laboratory Medicine (J.Q.T.), and Psychiatry (D.W.), Perelman School of Medicine at the University of Pennsylvania; the Department of Biostatistics and Epidemiology (S.X.X.), University of Pennsylvania; Philadelphia Veterans Affairs Medical Center (J.E.D., J.F.M., D.W.); and Avid Radiopharmaceuticals (A.S.), Philadelphia, PA.
authors.forename: Kara
authors.initials: K
authors.lastname: Pigott
authors.affiliation: From the Departments of Neurology (K.P., J.R., H.H., A.C.-P., J.E.D., J.F.M., L.M.C., N.D., R.S.A., D.W.), Pathology and Laboratory Medicine (J.Q.T.), and Psychiatry (D.W.), Perelman School of Medicine at the University of Pennsylvania; the Department of Biostatistics and Epidemiology (S.X.X.), University of Pennsylvania; Philadelphia Veterans Affairs Medical Center (J.E.D., J.F.M., D.W.); and Avid Radiopharmaceuticals (A.S.), Philadelphia, PA.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Rick
authors.affiliation: From the Departments of Neurology (K.P., J.R., H.H., A.C.-P., J.E.D., J.F.M., L.M.C., N.D., R.S.A., D.W.), Pathology and Laboratory Medicine (J.Q.T.), and Psychiatry (D.W.), Perelman School of Medicine at the University of Pennsylvania; the Department of Biostatistics and Epidemiology (S.X.X.), University of Pennsylvania; Philadelphia Veterans Affairs Medical Center (J.E.D., J.F.M., D.W.); and Avid Radiopharmaceuticals (A.S.), Philadelphia, PA.
authors.forename: Sharon X
authors.initials: SX
authors.lastname: Xie
authors.affiliation: From the Departments of Neurology (K.P., J.R., H.H., A.C.-P., J.E.D., J.F.M., L.M.C., N.D., R.S.A., D.W.), Pathology and Laboratory Medicine (J.Q.T.), and Psychiatry (D.W.), Perelman School of Medicine at the University of Pennsylvania; the Department of Biostatistics and Epidemiology (S.X.X.), University of Pennsylvania; Philadelphia Veterans Affairs Medical Center (J.E.D., J.F.M., D.W.); and Avid Radiopharmaceuticals (A.S.), Philadelphia, PA.
authors.forename: Howard
authors.initials: H
authors.lastname: Hurtig
authors.affiliation: From the Departments of Neurology (K.P., J.R., H.H., A.C.-P., J.E.D., J.F.M., L.M.C., N.D., R.S.A., D.W.), Pathology and Laboratory Medicine (J.Q.T.), and Psychiatry (D.W.), Perelman School of Medicine at the University of Pennsylvania; the Department of Biostatistics and Epidemiology (S.X.X.), University of Pennsylvania; Philadelphia Veterans Affairs Medical Center (J.E.D., J.F.M., D.W.); and Avid Radiopharmaceuticals (A.S.), Philadelphia, PA.
authors.forename: Alice
authors.initials: A
authors.lastname: Chen-Plotkin
authors.affiliation: From the Departments of Neurology (K.P., J.R., H.H., A.C.-P., J.E.D., J.F.M., L.M.C., N.D., R.S.A., D.W.), Pathology and Laboratory Medicine (J.Q.T.), and Psychiatry (D.W.), Perelman School of Medicine at the University of Pennsylvania; the Department of Biostatistics and Epidemiology (S.X.X.), University of Pennsylvania; Philadelphia Veterans Affairs Medical Center (J.E.D., J.F.M., D.W.); and Avid Radiopharmaceuticals (A.S.), Philadelphia, PA.
authors.forename: John E
authors.initials: JE
authors.lastname: Duda
authors.affiliation: From the Departments of Neurology (K.P., J.R., H.H., A.C.-P., J.E.D., J.F.M., L.M.C., N.D., R.S.A., D.W.), Pathology and Laboratory Medicine (J.Q.T.), and Psychiatry (D.W.), Perelman School of Medicine at the University of Pennsylvania; the Department of Biostatistics and Epidemiology (S.X.X.), University of Pennsylvania; Philadelphia Veterans Affairs Medical Center (J.E.D., J.F.M., D.W.); and Avid Radiopharmaceuticals (A.S.), Philadelphia, PA.
authors.forename: James F
authors.initials: JF
authors.lastname: Morley
authors.affiliation: From the Departments of Neurology (K.P., J.R., H.H., A.C.-P., J.E.D., J.F.M., L.M.C., N.D., R.S.A., D.W.), Pathology and Laboratory Medicine (J.Q.T.), and Psychiatry (D.W.), Perelman School of Medicine at the University of Pennsylvania; the Department of Biostatistics and Epidemiology (S.X.X.), University of Pennsylvania; Philadelphia Veterans Affairs Medical Center (J.E.D., J.F.M., D.W.); and Avid Radiopharmaceuticals (A.S.), Philadelphia, PA.
authors.forename: Lama M
authors.initials: LM
authors.lastname: Chahine
authors.affiliation: From the Departments of Neurology (K.P., J.R., H.H., A.C.-P., J.E.D., J.F.M., L.M.C., N.D., R.S.A., D.W.), Pathology and Laboratory Medicine (J.Q.T.), and Psychiatry (D.W.), Perelman School of Medicine at the University of Pennsylvania; the Department of Biostatistics and Epidemiology (S.X.X.), University of Pennsylvania; Philadelphia Veterans Affairs Medical Center (J.E.D., J.F.M., D.W.); and Avid Radiopharmaceuticals (A.S.), Philadelphia, PA.
authors.forename: Nabila
authors.initials: N
authors.lastname: Dahodwala
authors.affiliation: From the Departments of Neurology (K.P., J.R., H.H., A.C.-P., J.E.D., J.F.M., L.M.C., N.D., R.S.A., D.W.), Pathology and Laboratory Medicine (J.Q.T.), and Psychiatry (D.W.), Perelman School of Medicine at the University of Pennsylvania; the Department of Biostatistics and Epidemiology (S.X.X.), University of Pennsylvania; Philadelphia Veterans Affairs Medical Center (J.E.D., J.F.M., D.W.); and Avid Radiopharmaceuticals (A.S.), Philadelphia, PA.
authors.forename: Rizwan S
authors.initials: RS
authors.lastname: Akhtar
authors.affiliation: From the Departments of Neurology (K.P., J.R., H.H., A.C.-P., J.E.D., J.F.M., L.M.C., N.D., R.S.A., D.W.), Pathology and Laboratory Medicine (J.Q.T.), and Psychiatry (D.W.), Perelman School of Medicine at the University of Pennsylvania; the Department of Biostatistics and Epidemiology (S.X.X.), University of Pennsylvania; Philadelphia Veterans Affairs Medical Center (J.E.D., J.F.M., D.W.); and Avid Radiopharmaceuticals (A.S.), Philadelphia, PA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Siderowf
authors.affiliation: From the Departments of Neurology (K.P., J.R., H.H., A.C.-P., J.E.D., J.F.M., L.M.C., N.D., R.S.A., D.W.), Pathology and Laboratory Medicine (J.Q.T.), and Psychiatry (D.W.), Perelman School of Medicine at the University of Pennsylvania; the Department of Biostatistics and Epidemiology (S.X.X.), University of Pennsylvania; Philadelphia Veterans Affairs Medical Center (J.E.D., J.F.M., D.W.); and Avid Radiopharmaceuticals (A.S.), Philadelphia, PA.
authors.forename: John Q
authors.initials: JQ
authors.lastname: Trojanowski
authors.affiliation: From the Departments of Neurology (K.P., J.R., H.H., A.C.-P., J.E.D., J.F.M., L.M.C., N.D., R.S.A., D.W.), Pathology and Laboratory Medicine (J.Q.T.), and Psychiatry (D.W.), Perelman School of Medicine at the University of Pennsylvania; the Department of Biostatistics and Epidemiology (S.X.X.), University of Pennsylvania; Philadelphia Veterans Affairs Medical Center (J.E.D., J.F.M., D.W.); and Avid Radiopharmaceuticals (A.S.), Philadelphia, PA. daniel.weintraub@uphs.upenn.edu.
authors.forename: Daniel
authors.initials: D
authors.lastname: Weintraub
mesh_terms: D000368:Aged; D003071:Cognition / Q000502:physiology*; D060825:Cognitive Dysfunction / Q000150:complications* / Q000175:diagnosis; D018450:Disease Progression; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications*; D011446:Prospective Studies