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Alzheimer's disease (AD) has been associated with functional alterations in a distributed network of brain regions linked to memory function, with a recent focus on the cortical regions collectively known as the default network. Posterior components of the default network, including the precuneus and posterior cingulate, are particularly vulnerable to early(More)
OBJECTIVE To use fMRI to investigate whether hippocampal and entorhinal activation during learning is altered in the earliest phase of mild cognitive impairment (MCI). METHODS Three groups of older individuals were studied: 10 cognitively intact controls, 9 individuals at the mild end of the spectrum of MCI, and 10 patients with probable Alzheimer disease(More)
The hallmark clinical symptom of early Alzheimer's disease (AD) is episodic memory impairment. Recent functional imaging studies suggest that memory function is subserved by a set of distributed networks, which include both the medial temporal lobe (MTL) system and the set of cortical regions collectively referred to as the default network. Specific regions(More)
The neural underpinnings of age-related memory impairment remain to be fully elucidated. Using a subsequent memory face-name functional MRI (fMRI) paradigm, young and old adults showed a similar magnitude and extent of hippocampal activation during successful associative encoding. Young adults demonstrated greater deactivation (task-induced decrease in BOLD(More)
OBJECTIVE Cerebrovascular deposition of beta-amyloid (cerebral amyloid angiopathy [CAA]) is a major cause of hemorrhagic stroke and a likely contributor to vascular cognitive impairment. We evaluated positron emission tomographic imaging with the beta-amyloid-binding compound Pittsburgh Compound B (PiB) as a potential noninvasive method for detection of(More)
OBJECTIVE To examine alterations in patterns of brain activation seen in normal aging and in mild Alzheimer's disease by functional magnetic resonance imaging (fMRI) during an associative encoding task. METHODS 10 young controls, 10 elderly controls, and seven patients with mild Alzheimer's disease were studied using fMRI during a face-name association(More)
Despite the important role that attending to novel events plays in human behavior, there is limited information about the neuroanatomical underpinnings of this vital activity. This study investigated the relative contributions of the frontal and posterior parietal lobes to the differential processing of novel and target stimuli under an experimental(More)
BACKGROUND Extrapyramidal motor symptoms precede dementia in Parkinson disease (PDD) by many years, whereas dementia occurs early in dementia with Lewy bodies (DLB). Despite this clinical distinction, the neuropsychological and neuropathologic features of these conditions overlap. In addition to widespread distribution of Lewy bodies, both diseases have(More)
The amyloid cascade hypothesis suggests that the aggregation and deposition of amyloid-beta protein is an initiating event in Alzheimer's disease (AD). Using amyloid imaging technology, such as the positron emission tomography (PET) agent Pittsburgh compound-B (PiB), it is possible to explore the natural history of preclinical amyloid deposition in people(More)
OBJECTIVE To determine whether amyloid deposition is associated with impaired neuropsychological (NP) performance and whether cognitive reserve (CR) modifies this association. METHODS In 66 normal elderly controls and 17 patients with Alzheimer disease (AD), we related brain retention of Pittsburgh Compound B (PiB) to NP performance and evaluated the(More)