scholarly journals Vascular burden and cognition: Mediating roles of neurodegeneration and amyloid-PET

2021 ◽  
Author(s):  
Julie Ottoy ◽  
Miracle Ozzoude ◽  
Katherine Zukotynski ◽  
Sabrina Adamo ◽  
Christopher Scott ◽  
...  
Keyword(s):  
Temporal Lobe ◽  
Small Vessel Disease ◽  
Cortical Atrophy ◽  
White Matter Hyperintensity ◽  
Amyloid Pet ◽  
Semantic Fluency ◽  
Cognitive Domains ◽  
Vascular Burden ◽  
Dependent Pathway ◽  
Lobe Atrophy

INTRODUCTION: It remains unclear to which extent vascular burden promotes neurodegeneration and cognitive dysfunction in a cohort spanning low-to-severe small vessel disease (SVD) and amyloid-beta pathology. METHODS: In 120 subjects, we investigated 1) whether vascular burden, quantified as total or lobar white matter hyperintensity (WMH) volumes, is associated with different cognitive domains; and 2) whether the total WMH effect on cognition is mediated by amyloid (18F-AV45-PET), glucose metabolism (18F-FDG-PET), and/or cortical atrophy. RESULTS: Increased total WMH volume was associated with poorer performance in all cognitive domains tested, with the strongest effects observed for semantic fluency. These relationships were mediated mainly through cortical atrophy, particularly in the temporal lobe, and to a lesser extent through amyloid and metabolism. WMH volumes differentially impacted cognition depending on lobar location and amyloid status. DISCUSSION: Our study suggests mainly an amyloid-dependent pathway in which vascular burden affects cognitive impairment through temporal lobe atrophy.

scholarly journals Patterns of longitudinal cortical atrophy over 3 years in empirically derived MCI subtypes

Neurology ◽  
2020 ◽  
Vol 94 (24) ◽  
pp. e2532-e2544 ◽  
Author(s):  
Emily C. Edmonds ◽  
Alexandra J. Weigand ◽  
Sean N. Hatton ◽  
Anisa J. Marshall ◽  
Kelsey R. Thomas ◽  
...  
Keyword(s):  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Diagnostic Errors ◽  
Structural Mri ◽  
Cortical Atrophy ◽  
Linear Modeling ◽  
Cognitively Normal ◽  
Cognitive Domains ◽  
Amnestic Mci ◽  
Neuropsychological Assessments

ObjectiveWe previously identified 4 empirically derived mild cognitive impairment (MCI) subtypes via cluster analysis within the Alzheimer's Disease Neuroimaging Initiative (ADNI) and demonstrated high correspondence between patterns of cortical thinning at baseline and each cognitive subtype. We aimed to determine whether our MCI subtypes demonstrate unique longitudinal atrophy patterns.MethodsADNI participants (295 with MCI and 134 cognitively normal [CN]) underwent annual structural MRI and neuropsychological assessments. General linear modeling compared vertex-wise differences in cortical atrophy rates between each MCI subtype and the CN group. Linear mixed models examined trajectories of cortical atrophy over 3 years within lobar regions of interest.ResultsCompared to the CN group, those with amnestic MCI (memory deficit) initially demonstrated greater atrophy rates within medial temporal lobe regions that became more widespread over time. Those with dysnomic/amnestic MCI (naming/memory deficits) showed greater atrophy rates largely localized to temporal lobe regions. The mixed MCI (impairment in all cognitive domains) group showed greater atrophy rates in widespread regions at all time points. The cluster-derived normal group, who had intact neuropsychological performance and normal cortical thickness at baseline despite their MCI diagnosis via conventional diagnostic criteria, continued to show normal cognition and minimal cortical atrophy over 3 years.ConclusionsADNI's purported amnestic MCI sample produced more refined cognitive subtypes with unique longitudinal cortical atrophy rates. These novel MCI subtypes reliably reflect underlying atrophy, reduce false-positive diagnostic errors, and improve prediction of clinical course. Such improvements have implications for the selection of participants for clinical trials and for providing more precise risk assessment for individuals diagnosed with MCI.

scholarly journals Visual Ratings of Medial Temporal Lobe Atrophy Correlate with CSF Tau Indices in Clinical Variants of Early-Onset Alzheimer Disease

2017 ◽  
Vol 44 (1-2) ◽  
pp. 45-54 ◽  
Author(s):  
Elias Granadillo ◽  
Pongsatorn Paholpak ◽  
Mario F. Mendez ◽  
Edmond Teng
Keyword(s):  
Alzheimer Disease ◽  
Temporal Lobe ◽  
Early Onset ◽  
Medial Temporal Lobe ◽  
Late Onset ◽  
Brain Mri ◽  
Cortical Atrophy ◽  
Medial Temporal Lobe Atrophy ◽  
Underlying Mechanisms ◽  
Lobe Atrophy

Background/Aims: Prior studies of late-onset Alzheimer disease (AD) have reported that cerebrospinal fluid (CSF) tau levels correlate with hippocampal/medial temporal lobe atrophy. These findings suggest that CSF tau indices in AD may reflect tau-related neurodegeneration in the medial temporal lobe. However, it remains uncertain whether elevated CSF tau levels in the clinically heterogeneous subtypes of early-onset AD (EOAD; amnestic, posterior cortical atrophy [PCA], and logopenic progressive aphasia [LPA]) are attributable to similar underlying mechanisms. Methods: We identified 41 EOAD patients (18 amnestic, 14 with LPA, and 9 with PCA) with CSF and brain MRI data. Semiquantitative ratings were used to assess medial temporal lobe atrophy and PCA, which were compared to CSF biomarker indices. Results: Lower CSF tau levels were seen in PCA relative to amnestic EOAD and LPA, but similar ratings for medial temporal lobe atrophy and PCA were seen across the groups. After adjustments for demographics and cognitive performance, both total (p = 0.004) and hyperphosphorylated (p = 0.026) tau levels correlated with medial temporal lobe atrophy across this EOAD cohort. Conclusions: These results replicate prior findings in late-onset AD and support the hypothesis that CSF tau levels primarily reflect tau-related neurodegenerative changes in the hippocampus/medial temporal lobe across the clinical subtypes of EOAD.

Effect of White Matter Hyperintensity on Medial Temporal Lobe Atrophy in Alzheimer’s Disease

2013 ◽  
Vol 69 (4) ◽  
pp. 229-235 ◽  
Author(s):  
Jae-Won Jang ◽  
SangYun Kim ◽  
Hye Yeon Na ◽  
Seha Ahn ◽  
Sang Jin Lee ◽  
...  
Keyword(s):  
White Matter ◽  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
White Matter Hyperintensity ◽  
Medial Temporal Lobe Atrophy ◽  
Lobe Atrophy

Does posterior cortical atrophy on MRI discriminate between Alzheimer's disease, dementia with Lewy bodies, and normal aging?

2012 ◽  
Vol 25 (1) ◽  
pp. 111-119 ◽  
Author(s):  
James O'Donovan ◽  
Rosie Watson ◽  
Sean J. Colloby ◽  
Michael J. Firbank ◽  
Emma J. Burton ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Temporal Lobe ◽  
Dementia With Lewy Bodies ◽  
Lewy Bodies ◽  
Normal Aging ◽  
Cortical Atrophy ◽  
Posterior Cortical Atrophy ◽  
Older Subjects ◽  
Lobe Atrophy

ABSTRACTBackground: Previous studies suggest that posterior cortical atrophy may be a useful marker for early onset Alzheimer's disease (AD). Dementia with Lewy bodies (DLB) is associated with less temporal lobe atrophy than AD, though posterior cortical atrophy may be greater. Therefore, we assessed whether visual rating scales for assessing posterior atrophy (PA), medial temporal lobe atrophy (MTA), and ventricular enlargement (VEn) aid in the discrimination between AD, DLB, and normal aging.Methods: T1-weighted MRI scans acquired at 3 Tesla were visually rated for PA (range 0–3), MTA (range 0–4), and VEn (range 0–3) in older subjects with AD (n = 36), DLB (n = 35), and healthy controls (n = 35). The diagnostic utility of MTA, PA, and VEn visual ratings in distinguishing AD and DLB from controls as well as AD from DLB was investigated.Results: Significantly higher MTA ratings were associated with AD and DLB compared to controls (p < 0.001). MTA ratings were greater in AD relative to DLB (U = 384.5, p = 0.004). For PA ratings, scores did not differ between groups (p = 0.20). VEn ratings were significantly higher in AD and DLB compared to controls (p = 0.003), but similar between AD and DLB (U = 384.5, p = 0.4).Conclusions: Unlike findings reported in younger subjects, visual ratings for PA are not a reliable marker at older ages for distinguishing AD from controls, or for distinguishing DLB from AD. However, visual ratings of MTA and VEn may be useful markers in distinguishing both AD and DLB from older subjects without dementia.

Defective production and recognition of actions in Pick's disease with temporal lobe atrophy (semantic dementia)

2009 ◽  
Vol 29 (2) ◽  
pp. 268-276 ◽  
Author(s):  
Masaki Kondo ◽  
Satoshi Mochizuki ◽  
Mutsutaka Kobayakawa ◽  
Natsuko Tsuruya ◽  
Mitsuru Kawamura
Keyword(s):  
Temporal Lobe ◽  
Semantic Dementia ◽  
Pick's Disease ◽  
Pick’S Disease ◽  
Lobe Atrophy
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