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Dementia is a multifactorial disorder that is likely influenced by both Alzheimer's disease (AD) and vascular pathologies. We evaluated domain-specific cognitive and neuropsychiatric dysfunction using a two-neuroimaging biomarker construct (beta-amyloid [Aβ] and cerebrovascular disease [CeVD]). We analyzed data from 216 memory clinic participants (mean age = 75.9 ± 6.9; 56.5% female) with neuropsychological and neuropsychiatric assessments, 3T-MRI, and Aβ-PET imaging. Structural equation modeling showed that the largest Aβ (A+) effect was on memory (B = -1.50) and apathy (B = 0.26), whereas CeVD effects were largest on language (B = -1.62) and hyperactivity (B = 0.32). Group comparisons showed that the A+C+ group had greater memory impairment (B = -1.55), hyperactivity (B = 0.79), and apathy (B = 0.74) compared to A-C+; and greater language impairment (B = -1.26) compared to A+C-. These potentially additive effects of Aβ and CeVD burden underline the importance of early detection and treatment of Aβ alongside optimal control of vascular risk factors as a potential strategy in preventing cognitive and neurobehavioral impairment., (Copyright © 2023. Published by Elsevier Inc.)

Comorbid neuropsychiatric symptoms are commonly found in individuals with dementia and is likely influenced by a combination of neurodegenerative and cerebrovascular pathophysiology. We evaluated the associations of a validated composite MRI-based quantitative measure of both neurodegeneration (hippocampus volume and cortical thickness of AD-specific regions) and cerebrovascular disease (CeVD; white matter hyperintensities and infarcts) with neuropsychiatric subsyndromes, and their interactions on cognition in a community-based sample across the disease spectrum (N = 773). Lower composite MRI scores corresponding to greater comorbid neurodegeneration and CeVD burden were associated with hyperactivity (OR = 1.48) and apathy (OR = 1.90) subsyndromes. Lower MRI scores with concomitant hyperactivity was associated with greater cognitive impairment, especially in patients who were at least moderately impaired, while the interaction with apathy was not dependent on disease stage. These MRI scores interaction models resulted in a better fit than models consisting of neurodegeneration or CeVD alone. Integrating multiple biomarkers with specific, disease stage-dependent neuropsychiatric subsyndromes may provide a more holistic risk profile to facilitate the identification of individuals at the highest risk of disease progression., (Copyright © 2021. Published by Elsevier Inc.)

Objectives: The informant-AD8 (i-AD8) was found to be reliable in detecting cognitive impairment and dementia in tertiary and primary health care settings. We evaluated the discriminability of the i-AD8, as compared to other brief cognitive measures, and its combination with the 5-minute Montreal Cognitive Assessment (MoCA) and Mini-Cog in detecting very mild dementia in an Asian older cohort., Design: The Epidemiology of Dementia in Singapore (EDIS) study recruited participants from a population-based eye disease study who were of Chinese, Malay, and Indian ethnicities., Setting and Participants: Participants aged ≥60 years were clinically assessed and diagnosed using the Clinical Dementia Rating (CDR) scale. Of the 761 participants recruited, 526 (69.1%) had no dementia (CDR = 0), 193 (25.4%) had very mild dementia (CDR = 0.5), and 42 (5.5%) had dementia (CDR ≥ 1)., Measures: Participants were administered the Mini-Mental State Examination, MoCA, Mini-Cog, and a local neuropsychological battery. Their informants were interviewed using the i-AD8. Receiver operating characteristic analyses were conducted to establish the optimal cut-off points, and all discriminatory indices were calculated., Results: The i-AD8 was good and equivalent to other cognitive tools in detecting dementia [area under the curve (AUC) = 0.89, sensitivity = 0.76, and specificity = 0.94] but only fair in detecting very mild dementia (AUC = 0.69, sensitivity = 0.62, and specificity = 0.73). Combination of the i-AD8 with 5-minute MoCA or Mini-Cog in compensatory or in conjunction showed minimal improvement to the clinical utility for dementia or very mild dementia. All scales yielded a high rate of false positives (positive predictive value < 0.70)., Conclusions and Implications: The i-AD8 has good discriminatory power in detecting dementia (CDR ≥ 1) and is brief enough to be applied as an effective screening tool in the community. However, the i-AD8 and other cognitive tools lacked classification accuracy in detecting very mild dementia (CDR = 0.5)., (Copyright © 2018 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.)