Date of Award

Winter 2-7-2025

Embargo Period

2-19-2025

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Neuroscience

College

College of Graduate Studies

First Advisor

Jane Joseph

Abstract

Alzheimer’s Disease (AD) and Alcohol Use Disorder (AUD) are two disorders associated with a degraded life quality, high mortality, and poor prognosis. Recent evidence suggests that AUD is a risk factor for AD though the exact relationship between the two disorders is unknown. This study aimed to elucidate the relationship between these disorders by determining which patterns of functional connectivity are associated with cognitive decline in AUD and mild cognitive impairment (MCI), a cognitive pathology which frequently precedes dementia. Both resting-state and task-based fMRI data collected from AUD, MCI, and healthy control (HC) participants were used in this study. The two task paradigms consist of an episodic memory encoding task and a spatial working-memory task. The resting-state data was used to extract the default mode network (DMN), the episodic memory encoding task data was used to extract the episodic memory network (EMN), and the spatial working-memory task data was used to extract the spatial working-memory network (SWMN). Graph theory metrics were used to characterize connectome profiles associated with cognitive impairment, as measured by the Montreal Cognitive Assessment (MoCA), Craft Story Delayed Recall, and Digit Span Backwards assessments. I hypothesized that the associations between MoCA, Craft Story 21 Delayed Recall, and/or Digit Span Backwards and graph theory features of the EMN and/or the DMN healthy controls. I also hypothesized that graph theory scores of the SWMN would be associated with one or more of the three aforementioned neuropsychological scores in AUD subjects. The association between eigenvector centrality of the EMN and Digit Span Backwards score was negative in both AUD and MCI subjects while this association was positive in HC subjects. This suggests that while a greater influence of the episodic memory encoding network over the activity of the entire brain is associated with higher working-memory performance in healthy individuals, greater influence of the EMN in AUD and MCI subjects is associated with poorer working-memory performance.

Rights

Copyright is held by the author. All rights reserved.

Download

Share

COinS