stilbenes and Amnesia

Assessment of disease biomarkers, particularly the in vivo assessment of amyloid-β (Aβ) burden with positron emission tomography (PET), is gradually becoming central to the diagnosis of mild cognitive impairment (MCI) due to Alzheimer's disease (AD). However, the incorporation of biomarker evidence to the diagnostic process is currently restricted mainly to research settings. The identification of memory measures that are associated with Aβ is of clinical relevance as this may enhance the confidence in making a diagnosis of MCI due to AD in clinical settings. Forty one persons with amnestic MCI underwent Aβ imaging with (18)F-Florbetaben PET, magnetic resonance imaging, and a comprehensive neuropsychological assessment. All measures of episodic memory were significantly correlated with Aβ burden, but regression analyses revealed a strong and selective association between story recall and Aβ over and beyond the effects of age, education, global cognition, hippocampal volume, or other memory tests. Analyses of sensitivity and specificity of memory measures to detect high versus low Aβ scans suggested that word-list recall performed better when high sensitivity was preferred, whereas story recall performed better when high specificity was preferred. In conclusion, a measure of story recall may increase the confidence in making a diagnosis of MCI due to AD in clinical settings.

Topics: Aged; Aged, 80 and over; Amnesia; Amyloidosis; Aniline Compounds; Arabidopsis Proteins; Biomarkers; Cognitive Dysfunction; Cyclophilins; Female; Fluorine Radioisotopes; Humans; Magnetic Resonance Imaging; Male; Memory, Episodic; Middle Aged; Neuropsychological Tests; Positron-Emission Tomography; Predictive Value of Tests; Protozoan Proteins; Regression Analysis; Reproducibility of Results; Sensitivity and Specificity; Stilbenes

Amyloid PET allows for the assessment of amyloid β status in the brain, distinguishing true Alzheimer's disease from Alzheimer's disease-mimicking conditions. Around 15-20% of patients with clinically probable Alzheimer's disease have been found to have no significant Alzheimer's pathology on amyloid PET. However, a limited number of studies had been conducted on this subpopulation in terms of clinical progression.. We investigated the risk factors that could affect the progression to dementia in patients with amyloid-negative amnestic mild cognitive impairment (MCI).. This study was a single-institutional, retrospective cohort study of patients over the age of 50 with amyloid-negative amnestic MCI who visited the memory clinic of Asan Medical Center with a follow-up period of more than 36 months. All participants underwent brain magnetic resonance imaging (MRI), detailed neuropsychological testing, and fluorine-18[F18]-florbetaben amyloid PET.. During the follow-up period, 39 of 107 patients progressed to dementia from amnestic MCI. In comparison with the stationary group, the progressed group had a more severe impairment in verbal and visual episodic memory function and hippocampal atrophy, which showed an Alzheimer's diseaselike pattern despite the lack of evidence for significant Alzheimer's disease pathology. Voxel-based morphometric MRI analysis revealed that the progressed group had a reduced gray matter volume in the bilateral cerebellar cortices, right temporal cortex, and bilateral insular cortices.. Considering the lack of evidence of amyloid pathology, clinical progression of these subpopulation may be caused by other neuropathologies such as TDP-43, abnormal tau or alpha synuclein that lead to neurodegeneration independent of amyloid-driven pathway. Further prospective studies incorporating biomarkers of Alzheimer's disease-mimicking dementia are warranted.

Topics: Aged; Alzheimer Disease; Amnesia; Aniline Compounds; Brain; Cognitive Dysfunction; Disease Progression; Female; Fluorine Radioisotopes; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Neuropsychological Tests; Positron-Emission Tomography; Republic of Korea; Retrospective Studies; Risk Factors; Stilbenes; tau Proteins

The aim of this study was to identify white matter structural networks of amnestic mild cognitive impairment (aMCI) dichotomized by β amyloid (Aβ) status and compare them using network-based statistics (NBS).. Patients underwent whole-brain diffusion-weighted magnetic resonance imaging, detailed neuropsychological test and [. One hundred sixteen participants (Aβ- cognitively normal [CN], n = 35; Aβ- aMCI, n = 42; Aβ+ aMCI, n = 39) were included. There was no subnetwork showing significant difference between Aβ+ aMCI and Aβ- aMCI. However, by comparing each aMCI group with control group, we found that supplementary motor areas were common hub regions. Intriguingly, Aβ+ aMCI showed reduced connectivity mainly in the medial frontal regions, while Aβ- aMCI showed somewhat uniform disruption when compared to CN.. Structural network analysis using network-based approach in aMCI may shed light on further understanding of white matter disruption in the prodromal stage of Alzheimer's disease.

Topics: Aged; Alzheimer Disease; Amnesia; Amyloid; Aniline Compounds; Brain; Brain Mapping; Cerebral Cortex; Cognitive Dysfunction; Diffusion Tensor Imaging; Female; Humans; Male; Neuropsychological Tests; Positron-Emission Tomography; Stilbenes; White Matter