Neuropsychiatric symptoms and brain morphology in patients with mild cognitive impairment and Alzheimer’s disease with dementia

Abstract

SUMMARY We present associations between neuropsychiatric symptoms (NPS) and brain morphology in a large sample of patients with mild cognitive impairment (MCI) and Alzheimer’s disease with dementia (AD dementia). Several studies assessed NPS factor structure in MCI and AD dementia, but we know of no study that tested for associations between NPS factors and brain morphology. The use of factor scores increases parsimony and power. For transparency, we performed an additional analysis with selected Neuropsychiatric Inventory – Questionnaire (NPI-Q) items. Including regional cortical thickness, cortical and subcortical volumes, we examined associations between NPS and brain morphology across the whole brain in an unbiased fashion. We reported both statistical significance and effect sizes, using linear models adjusted for multiple comparisons by false discovery rate (FDR). Moreover, we included an interaction term for diagnosis and could thereby compare associations of NPS and brain morphology between MCI and AD dementia. We found an association between the factor elation and thicker right anterior cingulate cortex across MCI and AD dementia. Associations between the factors depression to thickness of the banks of the left superior temporal sulcus and psychosis to the left post-central volume depended on diagnosis: in MCI these associations were positive, in AD dementia negative. Our findings indicate that NPS in MCI and AD dementia are not exclusively associated with atrophy and support previous findings of associations between NPS and mainly frontotemporal brain structures.

Associations between affective/vegetative neuropsychiatric symptoms and brain morphology in aging people with mild cognitive impairment and Alzheimer’s disease

“…AD-MCI intergroup comparison results revealed an association between depression and the right temporal middle region (volume and surface area) and the regression (Figure 2, image C) shows that as depression severity increases, there is a decrease in the temporal middle region for the AD group. Similar results have also been observed in previous studies, where Siafarikas et al . (2021) found a negative association between depression and the superior temporal gyrus in patients with AD and Lebedeva et al .…”

Is bigger better? Towards a mechanistic understanding of neuropsychiatric symptoms in Alzheimer’s disease

“…It is important to note that most prior studies report associations between NPS and decreased regional brain volumes and cortical thickness and white matter integrity. This is the context to consider "Neuropsychiatric symptoms and brain morphology in patients with mild cognitive impairment and Alzheimer's disease dementia" by Siafarikas et al (2021) in this issue of International Psychogeriatrics. They examined the cross-sectional associations of NPS with MRI features in 235 subjects with mild cognitive impairment (MCI) or AD.…”

Neural correlates of delusion in Alzheimer's disease and Mild Cognitive Impairment

“…It remains largely unclear the exact nature of the gap between patients with or without such neuropsychiatric changes. Previous studies have explored whether observable neural differences account for the presence of delusion, and were able to identify multiple brain regional correlates that might account for the symptoms [6][7][8][9][10][11][12] . While ndings indicated the frontal lobe as a converging site, many other regions showed inconsistent positive ndings 13,14 .…”