Parkinson's disease-cognitive rating scale: Psychometrics for mild cognitive impairment

Authors

  • Ramón Fernández de Bobadilla MS,

    1. Movement Disorders Unit, Neurology Department, Sant Pau Hospital, Barcelona, Spain
    2. Movement Disorders Section, Biomedical Research Institute (IIB-Sant Pau), Barcelona, Spain
    3. Departament de Medicina, Universitat Autònoma de Barcelona, Barcelona, Spain
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  • Javier Pagonabarraga MD, PhD,

    1. Movement Disorders Unit, Neurology Department, Sant Pau Hospital, Barcelona, Spain
    2. Movement Disorders Section, Biomedical Research Institute (IIB-Sant Pau), Barcelona, Spain
    3. Center for Networker Biomedical Research in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
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  • Saül Martínez-Horta MS,

    1. Movement Disorders Unit, Neurology Department, Sant Pau Hospital, Barcelona, Spain
    2. Movement Disorders Section, Biomedical Research Institute (IIB-Sant Pau), Barcelona, Spain
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  • Berta Pascual-Sedano MD, PhD,

    1. Movement Disorders Unit, Neurology Department, Sant Pau Hospital, Barcelona, Spain
    2. Movement Disorders Section, Biomedical Research Institute (IIB-Sant Pau), Barcelona, Spain
    3. Center for Networker Biomedical Research in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
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  • Antonia Campolongo BS,

    1. Movement Disorders Unit, Neurology Department, Sant Pau Hospital, Barcelona, Spain
    2. Movement Disorders Section, Biomedical Research Institute (IIB-Sant Pau), Barcelona, Spain
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  • Jaime Kulisevsky MD, PhD

    Corresponding author
    1. Movement Disorders Unit, Neurology Department, Sant Pau Hospital, Barcelona, Spain
    2. Movement Disorders Section, Biomedical Research Institute (IIB-Sant Pau), Barcelona, Spain
    3. Departament de Medicina, Universitat Autònoma de Barcelona, Barcelona, Spain
    4. Center for Networker Biomedical Research in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
    • Correspondence to: Dr. Jaime Kulisevsky, Movement Disorders Unit, Neurology Department, Sant Pau Hospital, Mas Casanovas 90–08041 Barcelona, Spain; jkulisevsky@santpau.cat

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  • Funding agencies: This study was partially supported by public funding from Fondo de Investigaciones Sanitarias ISCIII (FIS PI10/01498 and PI12/03005), CIBERNED, and unrestricted research grants from Merck-Serono and Boehringer, Spain.

  • Relevant conflicts of interest/financial disclosures: Nothing to report.

  • Full financial disclosures and author roles may be found in the online version of this article.

ABSTRACT

Lack of validated data on cutoff scores for mild cognitive impairment (MCI) and sensitivity to change in predementia stages of Parkinson's disease (PD) limit the utility of instruments measuring global cognition as screening and outcome measures in therapeutic trials. Investigators who were blinded to PD-Cognitive Rating Scale (PD-CRS) scores classified a cohort of prospectively recruited, nondemented patients into a PD with normal cognition (PD-NC) group and a PD with MCI (PD-MCI) group using Clinical Dementia Rating (CDR) and the Mattis Dementia Rating Scale-2 (MDRS-2). The discriminative power of the PD-CRS for PD-MCI was examined in a representative sample of 234 patients (145 in the PD-NC group; 89 in the PD-MCI group) and in a control group of 98 healthy individuals. Sensitivity to change in the PD-CRS score (the minimal clinically important difference was examined with the Clinical Global Impression of Change scale and was calculated with a combination of distribution-based and anchor-based approaches) was explored in a 6-month observational multicenter trial involving a subset of 120 patients (PD-NC, 63; PD-MCI, 57). Regression analysis demonstrated that PD-CRS total scores (P < 0.001) and age (P = 0.01) independently differentiated PD-NC from PD-MCI. Area under the receiver operating characteristic curve (AUC) analysis (AUC, 0.85; 95% confidence interval, 0.80–0.90) indicated that a score ≤81 of 134 was the optimal cutoff point on the total score for the PD-CRS (sensitivity, 79%; specificity, 80%; positive predictive value, 59%; negative predictive value, 91%). A range of change from 10 to 13 points on the PD-CRS total score was indicative of clinically significant change. These findings suggest that the PD-CRS is a useful tool to identify PD-MCI and to track cognitive changes in nondemented patients with PD. © 2013 International Parkinson and Movement Disorder Society

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