Neural Correlates of Delusions in Patients with Alzheimer's Disease

The neural correlates of delusions in Alzheimer's disease (AD) remain unclear. This thesis examined the neuropathological, structural volumetric, and resting-state functional connectivity (rs-fc) correlates associated with delusions in AD. We hypothesized that delusional AD patients will have greater disease severity characterized by higher AD pathology load and increased atrophy, as well as altered rs-fc compared to non-delusional patients. We found that delusions were associated with Lewy body pathology, vascular pathology, and vascular risk factors, but were not correlated with increased AD pathology. Patients who developed delusions showed increased atrophy of regions within the default mode network (DMN) following the onset of delusions, while the cohort that did not develop delusions did not exhibit significant atrophy in the DMN over a similar time frame. We found that decreased connectivity within the DMN, in particular disintegration of the inferior parietal lobule with the overall network, may be associated with delusions in AD.M.Sc