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Application Of A Novel Quantitative Tractography Based Analysis Of Diffusion Tensor Imaging To Examine Fiber Bundle Length In Human Cerebral White Matter, Robert H. Paul, Laurie M. Baker, Ryan P. Cabeen, Sarah Cooley
Application Of A Novel Quantitative Tractography Based Analysis Of Diffusion Tensor Imaging To Examine Fiber Bundle Length In Human Cerebral White Matter, Robert H. Paul, Laurie M. Baker, Ryan P. Cabeen, Sarah Cooley
Psychology Faculty Works
This paper reviews basic methods and recent applications of length-based fiber bundle analysis of cerebral white matter using diffusion magnetic resonance imaging (dMRI). Diffusion weighted imaging (DWI) is a dMRI technique that uses the random motion of water to probe tissue microstructure in the brain. Diffusion tensor imaging (DTI) is an extension of DWI that measures the magnitude and direction of water diffusion in cerebral white matter, using either voxel-based scalar metrics or tractography-based analyses. More recently, quantitative tractography based on diffusion tensor imaging (qtDTI) technology has been developed to help quantify aggregate structural anatomical properties of white matter fiber …
Reducing Csf Partial Volume Effects To Enhance Diffusion Tensor Imaging Metrics Of Brain Microstructure, Robert H. Paul, Lauren E. Salminen, Thomas E. Conturo, Jacob D. Bolzenius
Reducing Csf Partial Volume Effects To Enhance Diffusion Tensor Imaging Metrics Of Brain Microstructure, Robert H. Paul, Lauren E. Salminen, Thomas E. Conturo, Jacob D. Bolzenius
Psychology Faculty Works
Technological advances over recent decades now allow for in vivo observation of human brain tissue through the use of neuroimaging methods. While this field originated with techniques capable of capturing macrostructural details of brain anatomy, modern methods such as diffusion tensor imaging (DTI) that are now regularly implemented in research protocols have the ability to characterize brain microstructure. DTI has been used to reveal subtle micro-anatomical abnormalities in the prodromal phase ofº various diseases and also to delineate “normal” age-related changes in brain tissue across the lifespan. Nevertheless, imaging artifact in DTI remains a significant limitation for identifying true neural …
Evolution Of Neuroimaging Technology In The Modern Era, Robert H. Paul
Evolution Of Neuroimaging Technology In The Modern Era, Robert H. Paul
Psychology Faculty Works
Clinical applications in brain science have progressed at a glacial pace when compared to other medical disciplines. Treatments for most neurodegenerative brain diseases are limited, and cure strategies remain underdeveloped. Pressure to improve clinical outcomes in the neurological sciences is exacerbated by an aging population at risk for degenerative brain diseases. Fortunately, technical advances in the field of neuroimaging offer new promise, with enhanced characterization of microstructural anatomy, network connectivity, and functional biomarkers of health and disease. Articles highlighted in this issue describe cutting-edge applications targeting these outcomes using diffusion tensor imaging, diffusion-based tractography, and positron emission tomography. Finally, the …
Early Exposure To Traumatic Stressors Impairs Emotional Brain Circuitry, Robert H. Paul, Mayuresh S. Korgaonkar, Cassandra Antees, Leanne M. Williams
Early Exposure To Traumatic Stressors Impairs Emotional Brain Circuitry, Robert H. Paul, Mayuresh S. Korgaonkar, Cassandra Antees, Leanne M. Williams
Psychology Faculty Works
Exposure to early life trauma (ELT) is known to have a profound impact on mental development, leading to a higher risk for depression and anxiety. Our aim was to use multiple structural imaging methods to systematically investigate how traumatic stressors early in life impact the emotional brain circuits, typically found impaired with clinical diagnosis of depression and anxiety, across the lifespan in an otherwise healthy cohort. MRI data and self-reported histories of ELT from 352 healthy individuals screened for no psychiatric disorders were analyzed in this study. The volume and cortical thickness of the limbic and cingulate regions were assessed …
Hiv Dna Reservoir Increases Risk For Cognitive Disorders In Cart-Nave Patients, Robert H. Paul, Victor G. Valcour, Jintanat Ananworanich, Melissa Agsalda
Hiv Dna Reservoir Increases Risk For Cognitive Disorders In Cart-Nave Patients, Robert H. Paul, Victor G. Valcour, Jintanat Ananworanich, Melissa Agsalda
Psychology Faculty Works
Objectives Cognitive impairment remains frequent in HIV, despite combination antiretroviral therapy (cART). Leading theories implicate peripheral monocyte HIV DNA reservoirs as a mechanism for spread of the virus to the brain. These reservoirs remain present despite cART. The objective of this study was to determine if the level of HIV DNA in CD14+ enriched monocytes predicted cognitive impairment and brain injury. Methods We enrolled 61 cART-naïve HIV-infected Thais in a prospective study and measured HIV DNA in CD14+ enriched monocyte samples in a blinded fashion. We determined HAND diagnoses by consensus panel and all participants underwent magnetic resonance spectroscopy (MRS) …
Normative Scores For A Brief Neuropsychological Battery For The Detection Of Hiv-Associated Neurocognitive Disorder (Hand) Among South Africans, Robert H. Paul, Dinesh Singh, John A. Joska, Karl Goodkin
Normative Scores For A Brief Neuropsychological Battery For The Detection Of Hiv-Associated Neurocognitive Disorder (Hand) Among South Africans, Robert H. Paul, Dinesh Singh, John A. Joska, Karl Goodkin
Psychology Faculty Works
There is an urgent need to more accurately diagnose HIV-associated neurocognitive disorder (HAND) in Africa. Rapid screening tests for HIV-associated dementia are of limited utility due to variable sensitivity and specificity. The use of selected neuropsychological tests is more appropriate, but norms for HIV seronegative people are not readily available for sub-Saharan African populations. We sought to derive normative scores for two commonly used neuropsychological tests that generate four test scores -- namely the Trail-Making Test (Parts A and B) and the Digit Span Test [Forward (DSF) and Backward (DSB)]. To assess memory and recall, we used the memory item …
The Relationship Between Early Life Stress And Microstructural Integrity Of The Corpus Callosum In A Non-Clinical Population, Robert H. Paul, Lorrie Henry, Stuart M. Grieve, Thomas J. Guilmette
The Relationship Between Early Life Stress And Microstructural Integrity Of The Corpus Callosum In A Non-Clinical Population, Robert H. Paul, Lorrie Henry, Stuart M. Grieve, Thomas J. Guilmette
Psychology Faculty Works
Background: Previous studies have examined the impact of early life stress (ELS) on the gross morphometry of brain regions, including the corpus callosum. However, studies have not examined the relationship between ELS and the microstructural integrity of the brain. Previous studies have examined the impact of early life stress (ELS) on the gross morphometry of brain regions, including the corpus callosum. However, studies have not examined the relationship between ELS and the microstructural integrity of the brain. Methods: In the present study we evaluated this relationship in healthy non-clinical participants using diffusion tensor imaging (DTI) and self-reported history of ELS. …
Understanding Reported Cognitive Dysfunction In Older Adults With Cardiovascular Disease, Robert H. Paul, John Gunstad, Ronald A. Cohen, David F.
Understanding Reported Cognitive Dysfunction In Older Adults With Cardiovascular Disease, Robert H. Paul, John Gunstad, Ronald A. Cohen, David F.
Psychology Faculty Works
High HIV-1 DNA (HIV DNA) levels in peripheral blood mononuclear cells (PBMC) correlate with HIV-1-associated dementia (HAD) in patients on highly active antiretroviral therapy (HAART). If this relationship also exists among HAART-naïve patients, then HIV DNA may be implicated in the pathogenesis of HAD. In this study, we evaluated the relationship between HIV DNA and cognition in subjects naïve to HAART in a neuro AIDS cohort in Bangkok, Thailand. Subjects with and without HAD were recruited and matched for age, gender, education, and CD4 cell count. PBMC and cellular subsets were analyzed for HIV DNA using real-time PCR. The median …
Hiv Dna And Dementia In Treatment-Naive Hiv-1-Infected Individuals In Bangkok, Thailand, Robert H. Paul, Bruce Shiramizu, Silvia Ratto-Kim, Pasiri Sithinamsuwan
Hiv Dna And Dementia In Treatment-Naive Hiv-1-Infected Individuals In Bangkok, Thailand, Robert H. Paul, Bruce Shiramizu, Silvia Ratto-Kim, Pasiri Sithinamsuwan
Psychology Faculty Works
High HIV-1 DNA (HIV DNA) levels in peripheral blood mononuclear cells (PBMC) correlate with HIV-1-associated dementia (HAD) in patients on highly active antiretroviral therapy (HAART). If this relationship also exists among HAART-naïve patients, then HIV DNA may be implicated in the pathogenesis of HAD. In this study, we evaluated the relationship between HIV DNA and cognition in subjects naïve to HAART in a neuro AIDS cohort in Bangkok, Thailand. Subjects with and without HAD were recruited and matched for age, gender, education, and CD4 cell count. PBMC and cellular subsets were analyzed for HIV DNA using real-time PCR. The median …