Medicine and Health Sciences Commons^™

Longitudinal Trajectories Of Basal Forebrain Volume In Normal Aging And Alzheimer's Disease, Ying Xia, Paul Maruff, Vincent Doré, Pierrick Bourgeat, Simon M. Laws, Christopher Fowler, Stephanie R. Rainey-Smith, Ralph N. Martins, Victor L. Villemagne, Christopher C. Rowe, Colin L. Masters, Elizabeth J. Coulson, Jurgen Fripp

Research outputs 2022 to 2026

Dysfunction of the cholinergic basal forebrain (BF) system and amyloid- (A ) deposition are early pathological features in Alzheimer's disease (AD). However, their association in early AD is not well-established. This study investigated the nature and magnitude of volume loss in the BF, over an extended period, in 516 older adults who completed A -PET and serial magnetic resonance imaging scans. Individuals were grouped at baseline according to the presence of cognitive impairment (CU, CI) and A status (A −, A +). Longitudinal volumetric changes in the BF and hippocampus were assessed across groups. The results indicated that high A …

Midline Brain Structures In Adult Niemann-Pick Type C Disease: A Cross-Sectional Study, Mark Walterfang, Tsutomu Takahashi, Maria A. Di Biase, Vanessa L. Cropley, Daiki Sasabayashi, Michio Suzuki, Dennis Velakoulis, Christos Pantelis

Research outputs 2022 to 2026

Objective: A range of neuropathological changes occur in the brains of individuals with adult Niemann-Pick type C disease (NPC), a recessive disorder of cholesterol trafficking that results in accumulation of cholesterol and gangliosides in lysosomes, particularly in neurons. One of the most significant regions of grey matter loss occurs in the thalami, which abut the midline. What is not known is whether these are neurodevelopmental in origin well prior to symptomatic onset. We aimed to examine other markers of midline developmental anomalies in adults with NPC. Method: We examined the size of adhesio interthalamica (AI) and cavum septum pellucidum (CSP) …

Efficacy Of Prebiotic Dietary Intervention To Mitigate Risks For Dementia Via The Gut-Brain Axis, Lucille M. Yanckello

Theses and Dissertations--Pharmacology and Nutritional Sciences

Alzheimer’s disease (AD) is the most common form of dementia with various risk factors including age, environmental factors such as brain injury and genetic factors, such as the E4 allele of the Apolipoprotein gene. Presence of the APOE4 allele increases AD risk by two- to four- fold. Recent studies have shown that mild traumatic brain injury (mTBI), even without loss of consciousness, increases risk of dementia diagnosis by more than two-fold in military personnel and is also a significant environmental risk factor for developing dementia in the general population. The gut-brain axis (GBA) or bi-directional communication between the brain and …

Water Exchange Rate Across The Blood-Brain Barrier Is Associated With Csf Amyloid-Β 42 In Healthy Older Adults, Brian T. Gold, Xingfeng Shao, Tiffany L. Sudduth, Gregory A. Jicha, Donna M. Wilcock, Elayna R. Seago, Danny J. J. Wang

Sanders-Brown Center on Aging Faculty Publications

INTRODUCTION: We tested if water exchange across the blood-brain barrier (BBB), estimated with a noninvasive magnetic resonance imaging (MRI) technique, is associated with cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD) and neuropsychological function.

METHODS: Forty cognitively normal older adults (67–86 years old) were scanned with diffusion‐prepared, arterial spin labeling (DP‐ASL), which estimates water exchange rate across the BBB (k_w). Participants also underwent CSF draw and neuropsychological testing. Multiple linear regression models were run with kw as a predictor of CSF concentrations and neuropsychological scores.

RESULTS: In multiple brain regions, BBB kw was positively associated with CSF amyloid …

Examining Brain Connectivity And Reading Ability In Children, Alexandra M. Cross

Electronic Thesis and Dissertation Repository

In this thesis, I investigated the relationship between functional and structural connectivity and reading ability in children. Prior research has tended to use single word reading measures or composite measures, however this is problematic as reading is a complex skill relying on multiple subskills, such as decoding efficiency, sight word reading efficiency, reading comprehension, and rapid automatized naming. As a result, the multi-faceted relationship between brain connectivity and reading ability is not well understood. I aimed to address this issue by considering multiple reading subskills while examining the neural substrates of reading. In Chapter 2, I examined how individual differences …

Cardiorespiratory Fitness Diminishes The Effects Of Age On White Matter Hyperintensity Volume, Nathan F. Johnson, Ahmed A. Bahrani, David K. Powell, Gregory A. Jicha, Brian T. Gold

Physical Therapy Faculty Publications

White matter hyperintensities (WMHs) are among the most commonly observed marker of cerebrovascular disease. Age is a key risk factor for WMH development. Cardiorespiratory fitness (CRF) is associated with increased vessel compliance, but it remains unknown if high CRF affects WMH volume. This study explored the effects of CRF on WMH volume in community-dwelling older adults. We further tested the possibility of an interaction between CRF and age on WMH volume. Participants were 76 adults between the ages of 59 and 77 (mean age = 65.36 years, SD = 3.92) who underwent a maximal graded exercise test and structural brain …

Non-Invasive Mri Quantification Of Cerebrospinal Fluid Dynamics In Amyotrophic Lateral Sclerosis Patients., Lucas R Sass, Mohammadreza Khani, Jacob Romm, Marianne Schmid Daners, Kyle Mccain, Tavara Freeman, Gregory T Carter, Douglas L Weeks, Brian Petersen, Jason Aldred, Dena Wingett, Bryn A Martin

Articles, Abstracts, and Reports

BACKGROUND: Developing novel therapeutic agents to treat amyotrophic lateral sclerosis (ALS) has been difficult due to multifactorial pathophysiologic processes at work. Intrathecal drug administration shows promise due to close proximity of cerebrospinal fluid (CSF) to affected tissues. Development of effective intrathecal pharmaceuticals will rely on accurate models of how drugs are dispersed in the CSF. Therefore, a method to quantify these dynamics and a characterization of differences across disease states is needed.

METHODS: Complete intrathecal 3D CSF geometry and CSF flow velocities at six axial locations in the spinal canal were collected by T2-weighted and phase-contrast MRI, respectively. Scans were …

Development Of Anatomical And Functional Magnetic Resonance Imaging Measures Of Alzheimer Disease, Samaneh Kazemifar

Electronic Thesis and Dissertation Repository

Alzheimer disease is considered to be a progressive neurodegenerative condition, clinically characterized by cognitive dysfunction and memory impairments. Incorporating imaging biomarkers in the early diagnosis and monitoring of disease progression is increasingly important in the evaluation of novel treatments. The purpose of the work in this thesis was to develop and evaluate novel structural and functional biomarkers of disease to improve Alzheimer disease diagnosis and treatment monitoring. Our overarching hypothesis is that magnetic resonance imaging methods that sensitively measure brain structure and functional impairment have the potential to identify people with Alzheimer’s disease prior to the onset of cognitive decline. …

Disruption Of White Matter Integrity In Adult Survivors Of Childhood Brain Tumors: Correlates With Long-Term Intellectual Outcomes, Tricia Z. King, Liya Wang, Hui Mao

Psychology Faculty Publications

Background

Although chemotherapy and radiation treatment have contributed to increased survivorship, treatment-induced brain injury has been a concern when examining long-term intellectual outcomes of survivors. Specifically, disruption of brain white matter integrity and its relationship to intellectual outcomes in adult survivors of childhood brain tumors needs to be better understood.

Methods

Fifty-four participants underwent diffusion tensor imaging in addition to structural MRI and an intelligence test (IQ). Voxel-wise group comparisons of fractional anisotropy calculated from DTI data were performed using Tract Based Spatial Statistics (TBSS) on 27 survivors (14 treated with radiation with and without chemotherapy and 13 treated without …

Magnetic Resonance Imaging Of Folic Acid-Coated Magnetite Nanoparticles Reflects Tissue Biodistribution Of Long-Acting Antiretroviral Therapy., Tianyuzi Li, Howard Gendelman, Gang Zhang, Pavan Puligujja, Joellyn Mcmillan, Tatiana K. Bronich, Benson Edagwa, Xin-Ming Liu, Michael D. Boska

Journal Articles: Pharmacology & Experimental Neuroscience

Regimen adherence, systemic toxicities, and limited drug penetrance to viral reservoirs are obstacles limiting the effectiveness of antiretroviral therapy (ART). Our laboratory's development of the monocyte-macrophage-targeted long-acting nanoformulated ART (nanoART) carriage provides a novel opportunity to simplify drug-dosing regimens. Progress has nonetheless been slowed by cumbersome, but required, pharmacokinetic (PK), pharmacodynamics, and biodistribution testing. To this end, we developed a small magnetite ART (SMART) nanoparticle platform to assess antiretroviral drug tissue biodistribution and PK using magnetic resonance imaging (MRI) scans. Herein, we have taken this technique a significant step further by determining nanoART PK with folic acid (FA) decorated magnetite …

Multiple Subject Barycentric Discriminant Analysis (Musubada): How To Assign Scans To Categories Without Using Spatial Normalization, Hervé Abdi, Lynne J. Williams, Andrew C. Connolly, M. Ida Gobbini

Dartmouth Scholarship

We present a new discriminant analysis (DA) method called Multiple Subject Barycentric Discriminant Analysis (MUSUBADA) suited for analyzing fMRI data because it handles datasets with multiple participants that each provides different number of variables (i.e., voxels) that are themselves grouped into regions of interest (ROIs). Like DA, MUSUBADA (1) assigns observations to predefined categories, (2) gives factorial maps displaying observations and categories, and (3) optimally assigns observations to categories. MUSUBADA handles cases with more variables than observations and can project portions of the data table (e.g., subtables, which can represent participants or ROIs) on the factorial maps. Therefore MUSUBADA can …

Bold Signal In Both Ipsilateral And Contralateral Retinotopic Cortex Modulates With Perceptual Fading, Po-Jang Hsieh, Peter U. Tse

Dartmouth Scholarship

Under conditions of visual fixation, perceptual fading occurs when a stationary object, though present in the world and continually casting light upon the retina, vanishes from visual consciousness. The neural correlates of the consciousness of such an object will presumably modulate in activity with the onset and cessation of perceptual fading.

Method: In order to localize the neural correlates of perceptual fading, a green disk that had been individually set to be equiluminant with the orange background, was presented in one of the four visual quadrants; Subjects indicated with a button press whether or not the disk was subjectively visible …