Predictors of Mild Cognitive Impairment in Early-Stage Parkinson's Disease

• Type of Material: Article
• Authors: Brenda Hanna Pladdy, Emory University; Katherine Jones, Landon Center on Aging; Romeo Cabanban, Emory University; Rajesh Pahwa, University of Kansas Medical Center; Kelly E. Lyons, University of Kansas Medical Center
• Language: English
• Date: 2013-05-18
• Publisher: Karger: Open Access Journals
• Publication Version: Final Published Version
• Copyright Statement: © 2013 S. Karger AG, Basel
• License: Creative Commons Attribution-Noncommercial 3.0 Unported
• Final Published Version (URL): http://www.karger.com/Article/FullText/351421
• Title of Journal or Parent Work: Dementia and Geriatric Cognitive Disorders Extra
• ISSN: 1664-5464
• Volume: 3
• Issue: 1
• Start Page: 168
• End Page: 178
• Grant/Funding Information: The project described was supported by NIH/NINDS R21NS059649 (to B.H.-P.). Data were collected in the Landon Center on Aging at the University of Kansas Medical Center, while data analyses and manuscript preparation were conducted at the Emory University Medical School, Atlanta, Ga., USA.
• Research Categories: Biology, Neuroscience

Abstract

Aim: The aim of this study was to identify mild cognitive deficits in Parkinson's disease (PD) prior to extensive neurodegeneration and to evaluate the extent to which dopamine depletion and other disease-related predictors can explain cognitive profiles. Methods: Neuropsychological performances of 40 nondemented early-stage PD patients and 42 healthy controls were compared across on or off dopaminergic medications. Stepwise regression evaluated cognitive predictors of early-stage PD and disease-related predictors of PD cognition (levodopa dose, disease duration, Unified Parkinson's Disease Rating Scale score, sleep, quality of life, and mood) across on and off states. Results: Neuropsychological performance was lower in PD patients across cognitive domains with significant memory, naming, visuomotor, and complex attention/executive deficits, but with intact visuospatial, simple attention, and phonemic fluency functions. However, medication effects were absent except for simple attention. Regression analyses revealed age, working memory, and memory recall to be the best cognitive predictors of PD, while age, quality of life, disease duration, and anxiety predicted PD cognition in the off state. Conclusion: Nondemented early-stage PD patients presented with extensive mild cognitive deficits including prominent memory impairment. The profile was inconsistent with expected isolated frontostriatal dysfunction previously attributed to dopamine depletion and this highlights the need to further characterize extranigral sources of mild cognitive impairment in PD.