Neuroanatomical and neurocognitive correlates of delusion in Alzheimer's disease and mild cognitive impairment

• Published in: BMC neurology Vol. 24; no. 1; p. 89
• Main Authors: Kwak, Seyul, Kim, Hairin, Kim, Keun You, Oh, Da Young, Lee, Dasom, Nam, Gieun, Lee, Jun-Young
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 06-03-2024; BioMed Central; BMC
• Subjects: Alzheimer's disease; Analysis; Anatomy; Behavior; Brain architecture; Care and treatment; Caregivers; Cognition; Cognition & reasoning; Cognition disorders; Cognitive ability; Cognitive function; Consortia; Cortex (insular); Cortical thickness; Delusion; Delusional disorder; Delusions; Dementia; Dementia disorders; Diagnosis; Executive function; Medical imaging; Memory; Mental disorders; Neuroanatomy; Neurodegenerative diseases; Neuroimaging; Neuropsychiatric symptoms; Neuropsychological tests; Neuropsychology; Older people; Prefrontal cortex; Principal components analysis; Somatosensory cortex; Temporal cortex; Visual cortex; South Korea; Cortical thickness; Alzheimer’s disease; Neuropsychiatric symptoms; Neuropsychological test; Delusion; Cognitive function; Dementia
• ISSN: 1471-2377; 1471-2377
• DOI: 10.1186/s12883-024-03568-5

Neuropsychiatric symptoms and delusions are highly prevalent among people with dementia. However, multiple roots of neurobiological bases and shared neural basis of delusion and cognitive function remain to be characterized. By utilizing a fine-grained multivariable approach, we investigated distinct neuroanatomical correlates of delusion symptoms across a large population of dementing illnesses.
In this study, 750 older adults with mild cognitive impairment and Alzheimer's disease completed brain structural imaging and neuropsychological assessment. We utilized principal component analysis followed by varimax rotation to identify the distinct multivariate correlates of cortical thinning patterns. Five of the cognitive domains were assessed whether the general cognitive abilities mediate the association between cortical thickness and delusion.
The result showed that distributed thickness patterns of temporal and ventral insular cortex (component 2), inferior and lateral prefrontal cortex (component 1), and somatosensory-visual cortex (component 5) showed negative correlations with delusions. Subsequent mediation analysis showed that component 1 and 2, which comprises inferior frontal, anterior insula, and superior temporal regional thickness accounted for delusion largely through lower cognitive functions. Specifically, executive control function assessed with the Trail Making Test mediated the relationship between two cortical thickness patterns and delusions.
Our findings suggest that multiple distinct subsets of brain regions underlie the delusions among older adults with cognitive impairment. Moreover, a neural loss may affect the occurrence of delusion in dementia largely due to impaired general cognitive abilities.