Projects

ONGOING PROJECTS

MRI study of HIV-associated neurocognitive disorders (HAND) in adults (41-70 year old)

Despite the widespread use of combination antiretroviral therapy (cART), approximately half of individuals with HIV-infection are affected by HIV-associated neurocognitive disorders (HAND). There has been increasing pressure to identify neural targets for interventional behavioral and medical therapies, especially among persons at risk of progression to symptomatic HAND. Early interventions (prior to potentially additive neural damage) are likely to be more effective and have a better chance to preserve and improve cognitive function. In this and other projects, we are using a combination of behavioral testing, brain imaging, and machine learning techiques to study subtle and mild neural injury in adults living with HIV.

A multimodal MRI study of Alzheimer’s disease (AD) (55-80 year old)

Alzheimer's disease (AD) is a neurodegenerative disease and the most common cause of dementia. With no known cures or disease-modifying therapies, there is a pressing need to find biomarkers that can accurately assess and predict disease progression in asymptomatic patients. However, despite recent efforts and significant progress in research, finding such a biomarker remains a major challenge. Given that AD is hypothesized to lead to changes in neuronal function long before detectable behavioral symptoms and/or anatomical changes, functional magnetic resonance imaging (fMRI), with its ability to image brain function, has the potential to be a critical tool in the early detection of AD and the evaluation of treatments as a non-invasive technique.  However, some aspects of early AD pathological changes might be difficult to assess with fMRI, including white matter integrity decline, brain atrophy, and disrupted resting-state inter-regional functional connectivity. Therefore, integrating fMRI with other MRI modalities is expected to lead to an increase in sensitivity and accuracy in assessing AD progression. To test this hypothesis, here we propose to conduct a cross-sectional, multimodal MRI study, with an ultimate goal of developing and validating a multimodal MRI biomarker of asymptomatic AD that is highly sensitive to early AD pathological changes and can accurately detect and assess AD progression.

A multimodal neuroimaging (MRI+PET+CSF) study of AD in older HIV+ adults (65 or older)

In the era of combination antiretroviral therapy (cART), the prevalence of neurocognitive impairment, HIV-associated neurocognitive disorder, or HAND, remains high. The etiology of HAND in the cART era remains to be elucidated. Aging is an important risk factor, and HIV+ individuals aged 50 and over are at an elevated risk. With more than half of individuals living with HIV in the USA now 50 years old or older, there is an increasing demand for HAND diagnosis and treatment. However, this aging demographic also means an increasing fraction of the HIV+ populace advancing into the geriatric age range, and clinicians are now facing the challenge of differentiating HAND from other dementias of aging, especially Alzheimer's disease (AD)—the most common cause of dementia in HIV-uninfected older adults. Current biomarkers of AD are invasive and/or expensive, thus limiting their applicability in HIV clinical practice. Here we propose a multimodal neuroimaging project to examine AD-like phenotypes in older HIV+ individuals, with a focus on developing novel non-invasive MRI-based techniques that have the potential to differentiate AD from HAND.

Using transcranial direct current stimulation to treat HIV-associated neurocognitive disorders: a pilot study (40 or older)

Medical advance has transferred HIV-infection from a fatal illness to a chronic manageable condition. However, the prevalence of cognitive impairment, HIV-associated neurocognitive disorders, or HAND, remains high. Approximately half of HIV+ individuals are affected. With no proven treatment and a rapidly aging HIV+ populace, finding and developing alternative effective treatments for HAND is of increasing public health relevance. Transcranial direct current stimulation (tDCS) is a safe approach to modulate neuronal function in the brain, and has shown promise in improving cognitive performance in healthy controls and clinical patients. Here we will examine whether tDCS is a useful tool in treating HAND in individuals on cART with controlled viral load.