Characterizing mild cognitive impairment in incident Parkinson disease: the ICICLE-PD study

• Published in: Neurology Vol. 82; no. 4; p. 308
• Main Authors: Yarnall, Alison J, Breen, David P, Duncan, Gordon W, Khoo, Tien K, Coleman, Shirley Y, Firbank, Michael J, Nombela, Cristina, Winder-Rhodes, Sophie, Evans, Jonathan R, Rowe, James B, Mollenhauer, Brit, Kruse, Niels, Hudson, Gavin, Chinnery, Patrick F, O'Brien, John T, Robbins, Trevor W, Wesnes, Keith, Brooks, David J, Barker, Roger A, Burn, David J
• Format: Journal Article
• Language: English
• Published: United States 28.01.2014
• Subjects: Aged; Aged, 80 and over; Amyloid beta-Peptides - cerebrospinal fluid; Case-Control Studies; Cognitive Dysfunction - cerebrospinal fluid; Cognitive Dysfunction - diagnosis; Cognitive Dysfunction - etiology; Female; Humans; Intermediate Filament Proteins - cerebrospinal fluid; Male; Middle Aged; Neuropsychological Tests; Parkinson Disease - epidemiology; Peptide Fragments - cerebrospinal fluid; Retrospective Studies; Severity of Illness Index; tau Proteins - cerebrospinal fluid
• ISSN: 1526-632X
• DOI: 10.1212/WNL.0000000000000066

To describe the frequency of mild cognitive impairment (MCI) in Parkinson disease (PD) in a cohort of newly diagnosed incident PD cases and the associations with a panel of biomarkers. Between June 2009 and December 2011, 219 subjects with PD and 99 age-matched controls participated in clinical and neuropsychological assessments as part of a longitudinal observational study. Consenting individuals underwent structural MRI, lumbar puncture, and genotyping for common variants of COMT, MAPT, SNCA, BuChE, EGF, and APOE. PD-MCI was defined with reference to the new Movement Disorder Society criteria. The frequency of PD-MCI was 42.5% using level 2 criteria at 1.5 SDs below normative values. Memory impairment was the most common domain affected, with 15.1% impaired at 1.5 SDs. Depression scores were significantly higher in those with PD-MCI than the cognitively normal PD group. A significant correlation was found between visual Pattern Recognition Memory and cerebrospinal β-amyloid 1-42 levels (β standardized coefficient = 0.350; p = 0.008) after controlling for age and education in a linear regression model, with lower β-amyloid 1-42 and 1-40 levels observed in those with PD-MCI. Voxel-based morphometry did not reveal any areas of significant gray matter loss in participants with PD-MCI compared with controls, and no specific genotype was associated with PD-MCI at the 1.5-SD threshold. In a large cohort of newly diagnosed PD participants, PD-MCI is common and significantly correlates with lower cerebrospinal β-amyloid 1-42 and 1-40 levels. Future longitudinal studies should enable us to determine those measures predictive of cognitive decline.