Article Text
Abstract
Background Understanding the sequential progression of cognitive impairments in Parkinson’s disease (PD) is crucial for elucidating neuropathological underpinnings, refining the assessment of PD-related cognitive decline stages and enhancing early identification for targeted interventions. The first aim of this study was to use an innovative event-based modeling (EBM) analytic approach to estimate the sequence of cognitive declines in PD. The second aim was to validate the EBM by examining associations with EBM-derived individual-specific estimates of cognitive decline severity and performance on independent cognitive screening measures.
Methods This cross-sectional observational study included 99 people with PD who completed a neuropsychological battery. Individuals were classified as meeting the criteria for mild cognitive impairment (PD-MCI) or subtle cognitive decline by consensus. An EBM was constructed to compare cognitively healthy individuals with those with PD-MCI or subtle cognitive disturbances. Multivariable linear regression estimated associations between the EBM-derived stage of cognitive decline and performance on two independent cognitive screening tests.
Results The EBM estimated that tests assessing executive function and visuospatial ability become abnormal early in the sequence of PD-related cognitive decline. Each higher estimated stage of cognitive decline was associated with approximately 0.24 worse performance on the Dementia Rating Scale (p<0.001) and 0.26 worse performance on the Montreal Cognitive Assessment (p<0.001) adjusting for demographic and clinical variables.
Conclusion Findings from this study will have important clinical implications for practitioners, on specific cognitive tests to prioritise, when conducting neuropsychological evaluations with people with PD. Results also highlight the importance of frontal–subcortical system disruption impacting executive and visuospatial abilities.
- neuropsychology
- Parkinson's disease
- computational psychiatry
- cognitive neuropsychology
Data availability statement
Data are available upon reasonable request.
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Data availability statement
Data are available upon reasonable request.
Footnotes
Contributors AJP conceptualised the study, completed the data analysis and manuscript write-up and is the guarantor of the work. DMS contributed to the conceptualisation of the study, obtained funding, provided advice to the analysis plan and contributed to the manuscript write-up. GMP obtained funding and contributed to the manuscript write-up. ED contributed to the manuscript write-up. MWJ contributed to the manuscript write-up and obtained funding. EB contributed to the methodology and the manuscript write-up. JDVH provided advice on the statistical analysis and contributed to the manuscript write-up. IL contributed to the methodology and the manuscript write-up.
Funding This work was supported by grants from the US Department of Defense, US Army and US Army Medical Command Congressionally Directed Medical Research Programs (Grant Numbers: W81XWH18-1-0665, W81XWH18-1-0666, and W81XWH19-1-0443), Angie Proctor (Award number N/A) and Kirk Hyde (Award number N/A).
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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