Alzheimer’s Disease and Other Memory Disorders

The purpose of this study is to longitudinally characterize and evaluate changes in synaptic density in the brain using novel positron-emission tomography (PET) scans; magnetic resonance imaging (MRI), and clinical laboratory markers associated with HIV-related injury in the central nervous system. This study will test hypotheses relating to the presence and mechanisms of aberrant brain structure at the synaptic level in living humans with virologically controlled HIV on antiretroviral therapy. To evaluate associations between PET imaging radiotracers [11C]UCB-J, a ligand for presynaptic vesicle protein 2A (SV2A), a vesicle membrane protein expressed in synapses, and PET [11C]PBR28 a measure of microglia function in the brain, the Yale PET center has developed an advanced approach of combining multiple distinct ligands in coordinated same-day PET imaging. Additionally, the study will evaluate the associations of this novel synaptic density marker with well-established clinical measures of neurocognitive performance and laboratory measures of blood and cerebrospinal fluid (CSF).

Recent findings suggest that sleep disruption may contribute to the generation and maintenance of neuropsychiatric symptoms including anxiety, depression, agitation, irritation, and apathy while treating sleep disruption reduces these symptoms. Impairments in the neural systems that support emotion regulation may represent one causal mechanism mediating the relationship between sleep and emotional distress. However, this model has not yet been formally tested within a sample of individuals with or at risk for developing Alzheimer's Disease (AD)

This proposal aims to test a mechanistic model in which sleep disturbance contributes to neuropsychiatric symptoms through impairments in fronto-limbic emotion regulation function in a sample of individuals at risk for developing, or at an early stage of AD.

This study seeks to delineate the causal association between sleep disruption, fronto-limbic emotion regulation brain function, and neuropsychiatric symptoms. These aims will be achieved through a mechanistic, randomized 2-arm controlled trial design. 150 adults experiencing sleep disturbances and who also have cognitive impairment with the presence of at least mild neuropsychiatric symptoms will be randomized to receive either a sleep manipulation (Cognitive Behavioral Therapy for Insomnia CBT-I; n=75) or an active control (n=75). CBT-I improves sleep patterns through a combination of sleep restriction, stimulus control, mindfulness training, cognitive therapy targeting dysfunctional beliefs about sleep, and sleep hygiene education. Neuropsychiatric symptoms, fronto-limbic functioning, and sleep disruption will be assessed at baseline and at the end of the sleep manipulation through functional Magnetic Resonance Imaging (fMRI), clinical interviews, PSG recordings, and self-report questionnaires. Neuropsychiatric symptoms (anxiety and depression) and sleep disturbance (actigraphy, Insomnia Severity Index, and sleep diaries) will be assayed at baseline and each week throughout the sleep manipulation to assess week-to-week changes following an increasing number of CBT-I sessions. Wristwatch actigraphy will be acquired from baseline to the end of the sleep manipulation at week 11. Neuropsychiatric symptoms and sleep will be assessed again at six months post-manipulation.

Background:

About 5 million adults in the U.S. have Alzheimer s disease or another adult-onset neurodegenerative disorder. Many studies have found that inflammation in the brain contributes to these diseases. Researchers want to find a better way to measure this inflammation.

Objective:

To learn whether COX-1 and/or COX-2 is elevated in the brains of individuals with neurodegenerative brain disease compared to healthy volunteers.

Eligibility:

Adults age 18 years and older in good general health who have an adult-onset neurodegenerative dementia, such as AD, FTD, corticobasal syndrome, or Huntington s disease and healthy adult volunteers enrolled in protocols 01-M-0254 or 17-M-0181.

Design:

Participants will be screened with medical history, physical exam with vital signs, and lab tests. They will have a neuropsychological testing. Their heart function will be measured.

Participants will have a magnetic resonance imaging (MRI) scan. The MRI scanner is a metal tube surrounded by a strong magnetic field. Participants will lie on a table that slides in and out of the tube. The machine makes noise. Participants will get earplugs.

Participants will have 2 PET scans. They will be injected with the study drugs through an intravenous catheter placed in an arm vein. The PET scanner is shaped like a doughnut. Participants will lie on a bed that slides in and out of the scanner. A plastic mask will be molded to their head to keep them from moving. A thin plastic tube will be put into an artery at the wrist or elbow crease area. This will be used to draw blood during the scan.

Participants will have 2-3 study visits. Participation lasts 1 week to 4 months, depending on scheduling.