Selamawit Negash

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Mild cognitive impairment (MCI) refers to the transitional state between the cognitive changes of normal aging and very early dementia. MCI has generated a great deal of research from both clinical and research perspectives. Several population- and community-based studies have documented an accelerated rate of progression to dementia and Alzheimer's disease(More)
BACKGROUND In most patients, mild cognitive impairment (MCI) represents the clinically evident prodromal phase of dementia. This is most well established in amnestic MCI, which is most commonly a precursor to Alzheimer disease (AD). It follows, however, that subjects with MCI who have impairment in nonmemory domains may progress to non-AD degenerative(More)
BACKGROUND It remains unknown whether depression and apolipoprotein E genotype are risk factors for incident mild cognitive impairment (MCI). OBJECTIVE To determine whether elderly individuals with depression (measured by the short Geriatric Depression Scale) are at increased risk of developing incident MCI. DESIGN Prospective cohort study. SETTING(More)
BACKGROUND Although a majority of patients with amnestic mild cognitive impairment (aMCI) progress to Alzheimer disease, the natural history of nonamnestic MCI (naMCI) is less clear. Noninvasive imaging surrogates for underlying pathological findings in MCI would be clinically useful for identifying patients who may benefit from disease-specific treatments(More)
Debate exists regarding differences in the prevalence of Alzheimer disease (AD) in African Americans and Hispanics in the United States, with some evidence suggesting that the prevalence of AD may be considerably higher in these groups than in non-Hispanic whites. Despite this possible disparity, patients of minority ethnoracial groups often receive delayed(More)
This experiment investigated whether there are age differences in implicit learning of non-spatially arranged sequential patterns. We tested 12 young and 12 old participants for five sessions each in a non-spatial alternating serial reaction time (ASRT) task, in which predictable pattern events alternated with random, unpredictable ones. People of both ages(More)
Although neuritic plaques and neurofibrillary tangles in older adults are correlated with cognitive impairment and severity of dementia, it has long been recognized that the relationship is imperfect, as some people exhibit normal cognition despite high levels of Alzheimer's disease (AD) pathology. We compared the cellular, synaptic, and biochemical(More)
OBJECTIVE To compare logistic and bilogistic models to describe the pattern of cognitive decline in the preclinical phase of Alzheimer disease (AD). METHODS We conducted mixed effects modeling of Mayo Cognitive Factors Scores to determine the longitudinal pattern of cognitive decline in the period 10 years prior to and 5 years following a clinical(More)
OBJECTIVE To investigate the combined ability of hippocampal volumes, 1H magnetic resonance spectroscopy (MRS) metabolites, and cerebrovascular disease to predict the risk of progression to dementia in mild cognitive impairment (MCI). METHODS We identified 151 consecutively recruited subjects with MCI from the Mayo Clinic Alzheimer's Disease Research(More)
We investigate the potential for using latency-based measures of retrieval processing capacity to assess changes in perfomance specific to individuals with mild cognitive impairment (MCI), a reliable precursor state to Alzheimer's Disease. Use of these capacity measures is motivated in part by exploration of the effects of atrophy on a computational model(More)