title: People with Parkinson's disease and normal MMSE score have a broad range of cognitive performance.
abstract: Cognitive impairment, including dementia, is common in Parkinson's disease (PD). The Mini-Mental State Examination (MMSE) has been recommended as a screening tool for Parkinson's disease dementia (PDD), with values below 26 indicative of possible dementia. Using a detailed neuropsychological battery, we examined the range of cognitive impairment in PD patients with an MMSE score of 26 or higher. In this multicenter, cross-sectional, observational study, we performed neuropsychological testing in a sample of 788 PD patients with MMSE scores of 26 or higher. Evaluation included tests of global cognition, executive function, language, memory, and visuospatial skills. A consensus panel reviewed results for 342 subjects and assigned a diagnosis of no cognitive impairment, mild cognitive impairment, or dementia. Sixty-seven percent of the 788 subjects performed 1.5 standard deviations below the normative mean on at least one test. On eight of the 15 tests, more than 20% of subjects scored 1.5 standard deviations or more below the normative mean. Greatest impairments were found on Hopkins Verbal Learning and Digit Symbol Coding tests. The sensitivity of the MMSE to detect dementia was 45% in a subset of participants who underwent clinical diagnostic procedures. A remarkably wide range of cognitive impairment can be found in PD patients with a relatively high score on the MMSE, including a level of cognitive impairment consistent with dementia. Given these findings, clinicians must be aware of the limitations of the MMSE in detecting cognitive impairment, including dementia, in PD.
authors: Booth Gardner Parkinson's Care Center, Evergreen Hospital Medical Center, Kirkland, WA.
authors: Daniel J
authors: DJ
authors: Burdick
authors: Brenna
authors: B
authors: Cholerton
authors: G S
authors: GS
authors: Watson
authors: Andrew
authors: A
authors: Siderowf
authors: John Q
authors: JQ
authors: Trojanowski
authors: Daniel
authors: D
authors: Weintraub
authors: Beate
authors: B
authors: Ritz
authors: Shannon L
authors: SL
authors: Rhodes
authors: Renecca
authors: R
authors: Rausch
authors: Stewart A
authors: SA
authors: Factor
authors: Cathy
authors: C
authors: Wood-Siverio
authors: Joseph F
authors: JF
authors: Quinn
authors: Kathryn A
authors: KA
authors: Chung
authors: Sindhu
authors: S
authors: Srivatsal
authors: Karen L
authors: KL
authors: Edwards
authors: Thomas J
authors: TJ
authors: Montine
authors: Cyrus P
authors: CP
authors: Zabetian
authors: James B
authors: JB
authors: Leverenz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology*; D003430:Cross-Sectional Studies; D056344:Executive Function; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory; D008609:Mental Status Schedule; D008875:Middle Aged; D009483:Neuropsychological Tests; D019370:Observation; D010300:Parkinson Disease / Q000150:complications*; D014706:Verbal Learning
keywords: Parkinson's disease; Parkinson's disease with dementia; assessment of cognitive disorders/dementia; cognition; mild cognitive impairment