Biological psychiatry
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Biological psychiatry · May 2012
Depressive symptoms in mild cognitive impairment predict greater atrophy in Alzheimer's disease-related regions.
Depression has been associated with higher conversion rates from mild cognitive impairment (MCI) to Alzheimer's disease (AD) and may be a marker of prodromal AD that can be used to identify individuals with MCI who are most likely to progress to AD. Thus, we examined the neuroanatomical changes associated with depressive symptoms in MCI. ⋯ Depressive symptoms were associated with greater atrophy in AD-affected regions, increased cognitive decline, and higher rates of conversion to AD. Depression in individuals with MCI may be associated with underlying neuropathological changes, including prodromal AD, and may be a potentially useful clinical marker in identifying MCI patients who are most likely to progress to AD.
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Biological psychiatry · May 2012
Regional expansion of hypometabolism in Alzheimer's disease follows amyloid deposition with temporal delay.
Cross-sectional imaging studies suggest that patterns of hypometabolism (measured by [(18)F] fluorodeoxyglucose positron emission tomography [FDG-PET]) and amyloid deposition (measured by [(11)C] Pittsburgh Compound B [PiB]- PET) in Alzheimer's disease (AD) show some overlap with each other. This indicates that neuronal dysfunction might spread within the anatomical pattern of amyloid deposition. The aim of this study was to examine longitudinal regional patterns of amyloid deposition and hypometabolism in the same population of mild AD subjects and to establish their regional relationship to each other. ⋯ Longitudinal regional expansion of cerebral hypometabolism, as a measure of neuronal dysfunction in AD, seems to follow the anatomical pattern of amyloid deposition with temporal delay. This indicates that amyloid-based disruption of neuronal integrity might contribute to the regional expansion of neuronal dysfunction.