Journal of Alzheimer's disease : JAD
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PET imaging of amyloid-β has recently emerged as a valuable biomarker to support the in vivo diagnosis of Alzheimer's disease (AD). So far, however, no tracer is available suitable for general clinical routine application. Florbetaben is a promising 18F-labeled amyloid-β-targeted PET tracer currently in Phase 2/3 clinical development. ⋯ Ongoing florbetaben PET trials deal with correlating the in vivo PET signal to post mortem histopathology evaluation, and with investigating the value of the tracer to predict progression to AD at the stage of mild cognitive impairment. The preclinical and clinical data currently available verify florbetaben as a safe and efficacious PET tracer suitable for detection of amyloid-β deposition in the brain. The results of the ongoing trials will contribute to current knowledge on the characteristics of florbetaben, and will help to determine the future potential of florbetaben PET imaging as a visual adjunct to supplement the routine clinical "AD diagnostic toolbox".
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A strong perception exists that elderly people are at risk for persistent cognitive deterioration lasting longer than six months following major surgery, particularly heart surgery. Furthermore, based on laboratory evidence, investigators hypothesize that surgery or anesthesia might precipitate incident dementia. Recent clinical studies have found that cognition might frequently be impaired within the first few months postoperatively, and that such impairment may be associated with death or debility. ⋯ There is evidence that most patients recover cognition in the long-term, and that for those who experience persistent decline, this is probably attributable to underlying undiagnosed neurological disease or other co-morbidities rather than to surgery or to anesthesia. There is currently minimal clinical evidence linking surgery or anesthesia to incident dementia. Rigorous clinical research is needed to resolve the controversy whether anesthesia or surgery is likely to cause persistent neurological decline or to precipitate dementia.
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Comparative Study
Episodic memory decline predicts cortical amyloid status in community-dwelling older adults.
Intra-individual decline in memory and cognition is characteristic of prodromal Alzheimer's disease (AD) and may allow detection of very early AD pathology. Episodic memory task scores on a brief computerized cognitive battery (CogState) were prospectively evaluated at baseline, and 3-, 6-, 9-, 12-, and 24-months post-baseline. Linear mixed models were conducted to compute age-adjusted slopes. ⋯ One of the memory decliners and none of the non-decliners fulfilled criteria for mild cognitive impairment, but the groups did not differ with respect to subjective memory impairment, neuropsychological evidence of episodic memory impairment, or MRI imaging abnormalities. Intra-individual decline in episodic memory can be detected using a brief computerized cognitive performance test optimized to detect change in community-dwelling non-demented older persons and appears predictive of the presence of cerebral amyloid in about half of these persons. This approach may help detect early prodromal AD pathology in wider-scale community screening programs.
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Longitudinal changes of cerebrospinal fluid (CSF) biomarkers in Alzheimer's disease (AD) have been studied, but there are few consistent conclusions and even less is known about their variation during the different stages of the disease. We hypothesized that changes in CSF biomarker values would correlate with the progression of the cognitive decline in AD. One hundred and thirty-one memory clinic patients [56 AD, 57 mild cognitive impairment (MCI), 10 other neurological disorders, eight unimpaired subjects] underwent a clinical follow-up with repeated Mini-Mental Status Examination (MMSE) tests and two lumbar punctures with a median interval of 3 years. ⋯ Concentrations of hyperphosphorylated tau decline in the late stages of the AD process. The decrease of p-tau-181 appears to correlate with cognitive functioning and probably reflects neuronal loss. More longitudinal studies of CSF biomarker dynamics are needed, especially in patients during the preclinical stage of the disease.
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A brain atrophy and lesion index (BALI) based on high-field magnetic resonance imaging (MRI) has recently been validated to evaluate structural changes in the aging brain. The present study investigated the two-year progression of brain structural deficits in people with Alzheimer's disease (AD) and mild cognitive impairment (MCI), and in healthy control older adults (HC) using the BALI rating. ⋯ The BALI rating quantified the progression of brain deficits over two years, which is associated with cognitive decline. BALI ratings may be used to help summarize AD-associated structural variations.