title: Measuring mild cognitive impairment in patients with Parkinson's disease.
abstract: We examined the frequency of Parkinson disease with mild cognitive impairment (PD-MCI) and its subtypes and the accuracy of 3 cognitive scales for detecting PD-MCI using the new criteria for PD-MCI proposed by the Movement Disorders Society. Nondemented patients with Parkinson's disease completed a clinical visit with the 3 screening tests followed 1 to 3 weeks later by neuropsychological testing. Of 139 patients, 46 met Level 2 Task Force criteria for PD-MCI when impaired performance was based on comparisons with normative scores. Forty-two patients (93%) had multi-domain MCI. At the lowest cutoff levels that provided at least 80% sensitivity, specificity was 44% for the Montreal Cognitive Assessment and 33% for the Scales for Outcomes in Parkinson's Disease-Cognition. The Mini-Mental State Examination could not achieve 80% sensitivity at any cutoff score. At the highest cutoff levels that provided specificity of at least 80%, sensitivities were low (≤44%) for all tests. When decline from estimated premorbid levels was considered evidence of cognitive impairment, 110 of 139 patients were classified with PD-MCI, and 103 (94%) had multi-domain MCI. We observed dramatic differences in the proportion of patients who had PD-MCI using the new Level 2 criteria, depending on whether or not decline from premorbid level of intellectual function was considered. Recommendations for methods of operationalizing decline from premorbid levels constitute an unmet need. Among the 3 screening tests examined, none of the instruments provided good combined sensitivity and specificity for PD-MCI. Other tests recommended by the Task Force Level 1 criteria may represent better choices, and these should be the subject of future research.
authors.affiliation: Toronto Western Hospital Movement Disorders Centre and the Edmond J. Safra Program in Parkinson's Research, Toronto, Ontario, Canada. cmarras@uhnresearch.ca
authors.forename: Connie
authors.initials: C
authors.lastname: Marras
authors.forename: Melissa J
authors.initials: MJ
authors.lastname: Armstrong
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Meaney
authors.forename: Susan
authors.initials: S
authors.lastname: Fox
authors.forename: Brandon
authors.initials: B
authors.lastname: Rothberg
authors.forename: William
authors.initials: W
authors.lastname: Reginold
authors.forename: David F
authors.initials: DF
authors.lastname: Tang-Wai
authors.forename: David
authors.initials: D
authors.lastname: Gill
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Eslinger
authors.forename: Cindy
authors.initials: C
authors.lastname: Zadikoff
authors.forename: Nancy
authors.initials: N
authors.lastname: Kennedy
authors.forename: Fred J
authors.initials: FJ
authors.lastname: Marshall
authors.forename: Mark
authors.initials: M
authors.lastname: Mapstone
authors.forename: Kelvin L
authors.initials: KL
authors.lastname: Chou
authors.forename: Carol
authors.initials: C
authors.lastname: Persad
authors.forename: Irene
authors.initials: I
authors.lastname: Litvan
authors.forename: Benjamin T
authors.initials: BT
authors.lastname: Mast
authors.forename: Adam T
authors.initials: AT
authors.lastname: Gerstenecker
authors.forename: Sandra
authors.initials: S
authors.lastname: Weintraub
authors.forename: Sarah
authors.initials: S
authors.lastname: Duff-Canning
mesh_terms: D000368:Aged; D060825:Cognitive Dysfunction / Q000175:diagnosis* / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications*; D012372:ROC Curve; D012189:Retrospective Studies