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Alzheimer's disease (AD) is the most common cause of dementia. Much is known concerning AD pathophysiology but our understanding of the disease at the systems level remains incomplete. Previous AD research has used resting-state functional connectivity magnetic resonance imaging (rs-fcMRI) to assess the integrity of functional networks within the brain.(More)
OBJECTIVE Resting-state functional connectivity MRI (rs-fcMRI) may provide insight into the neurophysiology of HIV and aging. METHODS In this cross-sectional study, we used rs-fcMRI to investigate intra- and internetwork connectivity among 5 functional brain networks in 58 HIV-infected (HIV+) participants (44% receiving highly active antiretroviral(More)
OBJECTIVE To determine whether, and to what degree, preclinical Alzheimer disease (AD) confounds studies of healthy aging where "healthy" is based on cognitive normality alone. METHODS We examined the effects of preclinical AD in cognitively normal older individuals using resting-state functional connectivity MRI. We investigated 2 groups of cognitively(More)
Graph theory models can produce simple, biologically informative metrics of the topology of resting-state functional connectivity (FC) networks. However, typical graph theory approaches model FC relationships between regions (nodes) as unweighted edges, complicating their interpretability in studies of disease or aging. We extended existing techniques and(More)
OBJECTIVE HIV preferentially affects white matter in the brain. Although combination antiretroviral therapy (cART) reduces HIV viral load within the brain, continued inflammation can persist. We investigated the effect of HIV and cART on white matter integrity. DESIGN We used diffusion tensor imaging (DTI) to examine the effects of HIV and cART on white(More)
Alzheimer's disease (AD) has a long preclinical phase in which amyloid and tau cerebral pathology accumulate without producing cognitive symptoms. Resting state functional connectivity magnetic resonance imaging has demonstrated that brain networks degrade during symptomatic AD. It is unclear to what extent these degradations exist before symptomatic onset.(More)
OBJECTIVE To evaluate whether the amyloid-binding agent carbon 11-labeled Pittsburgh Compound B ((11)C-PiB) could differentiate Alzheimer disease (AD) from human immunodeficiency virus (HIV)-associated neurocognitive disorder (HAND) in middle-aged HIV-positive participants. DESIGN (11)C-PiB scanning, clinical assessment, and cerebrospinal fluid (CSF)(More)
Much effort in recent years has focused on understanding the effects of Alzheimer's disease (AD) on neural function. This effort has resulted in an enormous number of papers describing different facets of the functional derangement seen in AD. A particularly important tool for these investigations has been resting-state functional connectivity. Attempts to(More)
IMPORTANCE Autosomal dominant Alzheimer disease (ADAD) is caused by rare genetic mutations in 3 specific genes in contrast to late-onset Alzheimer disease (LOAD), which has a more polygenetic risk profile. OBJECTIVE To assess the similarities and differences in functional connectivity changes owing to ADAD and LOAD. DESIGN, SETTING, AND PARTICIPANTS We(More)
OBJECTIVE Early biomarkers of Alzheimer's disease (AD) are needed for developing therapeutic interventions. Measures of attentional control in Stroop-type tasks discriminate healthy aging from early stage AD and predict future development of AD in cognitively normal individuals. Disruption in resting state functional connectivity MRI (rs-fcMRI) has been(More)