title: Mild cognitive impairment in Parkinson's disease versus Alzheimer's disease.
abstract: No known studies have compared longitudinal characteristics between individuals with incident mild cognitive impairment due to Parkinson's disease (PD-MCI) versus Alzheimer's Disease (AD-MCI).
  
  
  
  We used longitudinal data from the National Alzheimer's Coordinating Center's Uniform Data Set to compare 41 PD-MCI and 191 AD-MCI participants according to their demographics, presence of ≥1 APOE e4 allele, and baseline and change over time in clinical characteristics, neuropsychological test scores, and Clinical Dementia Rating sum of boxes (CDR-SB). Multivariable linear regression models with generalized estimating equations were used to account for clustered data and to test for baseline and longitudinal differences in neuropsychological test scores.
  
  
  
  PD-MCI and AD-MCI participants differed by many demographic and clinical characteristics. Significantly fewer PD-MCI participants developed dementia over one year. Compared to AD-MCI participants, PD-MCI participants performed better at baseline and over time on a global measure of cognition (Mini Mental State Exam), memory measures (immediate and delayed Logical Memory), and a language measure (Boston Naming Test), and additionally performed better over time on an attention measure (Digit Span Forward), a language measure (Vegetable List), a processing speed measure (Digit Symbol), and an overall measure of memory and functional impairment (CDR-SB).
  
  
  
  Our study provides further evidence that PD-MCI is clinically distinct from AD-MCI and requires different tools for diagnosis and monitoring clinical progression. More importantly, this study suggests that PD-MCI takes longer to convert into dementia than AD-MCI, findings that require replication by other studies.
authors.affiliation: National Alzheimer's Coordinating Center, University of Washington, 4311 11th Ave NE, Suite 300, Seattle, WA, 98105, USA. Electronic address: lmbesser@uw.edu.
authors.forename: Lilah M
authors.initials: LM
authors.lastname: Besser
authors.affiliation: University of California San Diego, Department of Neurosciences, National Parkinson Foundation Movement Disorder Center of Excellence, 8950 Villa La Jolla Drive, Suite C112, La Jolla, CA, 92037, USA. Electronic address: ilitvan@ucsd.edu.
authors.forename: Irene
authors.initials: I
authors.lastname: Litvan
authors.affiliation: National Alzheimer's Coordinating Center, University of Washington, 4311 11th Ave NE, Suite 300, Seattle, WA, 98105, USA. Electronic address: smonsell@uw.edu.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Monsell
authors.affiliation: National Alzheimer's Coordinating Center, University of Washington, 4311 11th Ave NE, Suite 300, Seattle, WA, 98105, USA. Electronic address: cmock@u.washington.edu.
authors.forename: Charles
authors.initials: C
authors.lastname: Mock
authors.affiliation: Cognitive Neurology and Alzheimer's Disease Center, and Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, 320 E Superior, Searle 11-467, Chicago, IL, 60611, USA. Electronic address: sweintraub@northwestern.edu.
authors.forename: Sandra
authors.initials: S
authors.lastname: Weintraub
authors.affiliation: National Alzheimer's Coordinating Center, University of Washington, 4311 11th Ave NE, Suite 300, Seattle, WA, 98105, USA. Electronic address: azhou@u.washington.edu.
authors.forename: Xiao-Hua
authors.initials: XH
authors.lastname: Zhou
authors.affiliation: National Alzheimer's Coordinating Center, University of Washington, 4311 11th Ave NE, Suite 300, Seattle, WA, 98105, USA. Electronic address: Kukull@uw.edu.
authors.forename: Walter
authors.initials: W
authors.lastname: Kukull
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology*; D060825:Cognitive Dysfunction / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology*; D011446:Prospective Studies
keywords: Alzheimer's disease; Clinical progression; Mild cognitive impairment; Neuropsychological assessment; Parkinson's disease