Year of Publication

2018

Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation

College

Medicine

Department

Neuroscience

First Advisor

Dr. Peter T. Nelson

Abstract

Cerebrovascular disease is a major cause of dementia in elderly individuals, especially Black/African Americans. Within my dissertation, we focused on two vascular morphologies that affect small vessels: brain arteriolosclerosis (B-ASC) and multi-vascular profiles (MVPs). B-ASC is characterized by degenerative thickening of the wall of brain arterioles. The risk factors, cognitive sequelae, and co-pathologies of B-ASC are not fully understood. To address this, we used multimodal data from the National Alzheimer’s Coordinating Center, Alzheimer’s Disease Neuroimaging Initiative, and brain-banked tissue samples from the University of Kentucky Alzheimer’s Disease Center (UK-ADC) brain repository. We analyzed two age at death groups separately: < 80 years and ≥ 80 years. Hypertension was a risk factor in the < 80 years at death group. In addition, an ABCC9 gene variant (rs704180), previously associated with aging-related hippocampal sclerosis, was associated with B-ASC in the ≥ 80 years at death group. With respect to cognition as determined by test scores, severe B-ASC was associated with worse global cognition in both age groups. With brain-banked tissue samples, we described B-ASC’s relationship to hippocampal sclerosis of aging (HS-Aging), a pathology characterized by neuronal cell loss in the hippocampal region not due to Alzheimer’s disease. We also studied MVPs, which are characterized by multiple small vessel lumens within a single vascular (Virchow-Robin) space. Little information exists on the frequency, risk factors, and co-pathologies of MVPs. Therefore, we used samples and data from the UK-ADC, University of Kentucky pathology department, and University of Pittsburgh pathology department to address this information. We only found MVPs to be correlated with age. Lastly, given the high prevalence of cerebrovascular disease and dementia in Black/African Americans, we discussed the challenges and considerations for studying Blacks/African Americans in these contexts.

Digital Object Identifier (DOI)

https://doi.org/10.13023/ETD.2018.049

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