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Your search keyword '"BAUER, ROBERT"' showing total 24 results
Start Over Author "BAUER, ROBERT" Journal alzheimer's & dementia: the journal of the alzheimer's association
24 results on '"BAUER, ROBERT"'

1. Brain imaging measurements of fibrillar amyloid-β burden, paired helical filament tau burden, and atrophy in cognitively unimpaired persons with two, one, and no copies of the APOE ε4 allele

Author

Ghisays, Valentina, Goradia, Dhruman D., Protas, Hillary, Bauer, Robert J., III, Devadas, Vivek, Tariot, Pierre N., Lowe, Val J., Knopman, David S., Petersen, Ronald C., Jack, Clifford R., Jr., Caselli, Richard J., Su, Yi, Chen, Kewei, and Reiman, Eric M.

Published
2019
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2. Brain imaging measurements of fibrillar amyloid‐β burden, paired helical filament tau burden, and atrophy in cognitively unimpaired persons with two, one, and no copies of the APOE ε4 allele.

Author

Ghisays, Valentina, Goradia, Dhruman D., Protas, Hillary, Bauer, Robert J., Devadas, Vivek, Tariot, Pierre N., Lowe, Val J., Knopman, David S., Petersen, Ronald C., Jack, Clifford R., Caselli, Richard J., Su, Yi, Chen, Kewei, and Reiman, Eric M.

Abstract

Introduction: We previously characterized associations between brain imaging measurements of amyloid‐β (Aβ) plaque burden and apolipoprotein E (APOE) ε4 gene dose in a small number of cognitively unimpaired late‐middle‐aged APOE ε4 homozygotes (HMs), heterozygotes (HTs), and noncarriers (NCs). We now characterize cross‐sectional Aβ plaque, tau tangle, and cortical atrophy (neurodegeneration) measurements, classifications, and associations with age in a larger number of unimpaired HMs, HTs, and NCs over a wider age range. Methods: We analyzed 11C Pittsburgh compound B (Aβ) positron emission tomography (PET), flortaucipir (tau) PET, and volumetric magnetic resonance imaging data from 164 study participants of age 47–86 years, including 26 APOE ε4 HMs, 48 HTs, and 90 NCs matched for age and sex. Results: Aβ PET measurements rose, plateaued at the respective ages of 68 and 76, and then declined with age in unimpaired HM and HT groups. Compared with NCs, these two groups began to have significantly higher Aβ PET measurements at ages 62 and 70, respectively, and no longer had significantly higher measurements by ages 71 and 78, respectively. They began to have significantly higher entorhinal cortex tau PET measurements at ages 66 and 70, respectively, and no longer had significantly higher measurements by ages 74 and 78, respectively. Brain atrophy measurements tended to decline slowly with age in all three genetic groups. Their elevated tau PET measurements were attributable to those with positive Aβ PET scans. 41.0%, 18.0%, and 5.0% of the 47‐ to 70‐year‐old HMs, HTs, and NCs and 25.0%, 79.0%, and 38.0% of the 71‐ to 86‐year‐old HMs, HTs, and NCs had positive Aβ PET scans, and the long‐term recall memory scores are significantly higher in the older HMs than in HT and NC groups, suggesting resistance to Aβ deposition in those HMs who remained unimpaired at older ages. Conclusions: This study provides information about Aβ plaque burden, tau tangle burden, and neurodegeneration in cognitively unimpaired persons at three levels of genetic risk for AD. Unimpaired APOE ε4 HMs can be studied before their 70s to evaluate the understanding of factors, processes, and interventions involved in the predisposition to and prevention of AD, and after their 70s, to discover factors, processes, and interventions involved in the resilience or resistance to and prevention of AD. [ABSTRACT FROM AUTHOR]

Published
2020
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4. INDIVIDUAL-BASED NETWORK ANALYSIS: A NOVEL APPROACH TO INVESTIGATE THE PATHOLOGICAL SPREAD OF PHF TAU USING GRAPH THEORY IN CLINICAL AND PRECLINICAL STAGES OF ALZHEIMER’S DISEASE

Author

Protas, Hillary, Goradia, Dhruman D., Ghisays, Valentina, Luo, Ji, VanGilder, Paul S., Thiyyagura, Pradeep, Malek-Ahmadi, Michael, Lee, Wendy, Chen, Yinghua, Devadas, Vivek, Bauer, Robert, III, Landau, Susan M., Weiner, Michael W., Jagust, William J., Chen, Kewei, Su, Yi, and Reiman, Eric M.

Published
2019
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14. IMPROVING THE POWER TO TRACK FIBRILLAR AMYLOID PET MEASUREMENTS AND EVALUATE AMYLOID-MODIFYING TREATMENTS USING A CEREBRAL WHITE MATTER REFERENCE REGION-OF-INTEREST

Author

Chen, Kewei, Roontiva, Auttawut, Thiyyagura, Pradeep, Lee, Wendy, Liu, Xiaofen, Ayutyanont, Napatkamon, Protas, Hillary, Landau, Susan, Luo, Ji, Bauer, Robert, III, Reschke, Cole, Bandy, Dan, Koeppe, Robert, Fleisher, Adam S., Caselli, Richard J., Jagust, William, Weiner, Michael Walter, and Reiman, Eric M.

Published
2014
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16. The pattern of cerebral hypometabolism and its association with clinical ratings in cognitively normal older adults with and without significant fibrillar amyloid burden: Findings from the Alzheimer's Disease Neuroimaging Initiative

Author

Protas, Hillary, Chen, Kewei, Reschke, Cole, Roontiva, Auttawut, Liu, Xiaofen, Parks, Stephanie, Lee, Wendy, Bauer, Robert, III, Ayutyanont, Napatkamon, Thiyyagura, Pradeep, Koeppe, Robert, Jagust, William, Foster, Norman, Weiner, Michael, Fleisher, Adam, and Reiman, Eric

Published
2013
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17. Association between the Alzheimer's disease-related hypometabolic convergence index and clinical ratings in cognitively normal older adults with and without significant fibrillar amyloid burden: Findings from the Alzheimer's Disease Neuroimaging Initiative

Author

Roontiva, Auttawut, Chen, Kewei, Ayutyanont, Napatkamon, Protas, Hillary, Liu, Xiaofen, Thiyyagura, Pradeep, Lee, Wendy, Reschke, Cole, Parks, Stephanie, Bauer, Robert, III, Koeppe, Robert, Jagust, William, Foster, Norman, Weiner, Michael, Fleisher, Adam, and Reiman, Eric

Published
2013
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18. A novel longitudinal approach in individual subjects to investigate the movement of tau over time using graph theory in clinical and preclinical stages of Alzheimer's disease: Neuroimaging / New imaging methods.

Author

Protas, Hillary D., Ghisays, Valentina, Chen, Yinghua, Goradia, Dhruman D., Luo, Ji, Malek‐Ahmadi, Michael H., Lee, Wendy, Devadas, Vivek, Bauer, Robert, Reiman, Eric M., Chen, Kewei, and Su, Yi

Abstract

Background: We previously introduced an index characterizing inter‐regional tau deposition variability based on graph theory. Extending our method to additionally characterize the longitudinal tau spread for individual subjects based on directed graph theory, we examined the difference between longitudinal network measures and the regional tau deposit measures over time with respect to 1) differentiation of patients with AD, MCI, and cognitively unimpaired(CU) subjects, 2) correlation with memory measures in Aβ+ CU, and 3) sample size needed for a prevention trial for Aβ+/‐ CU. Method: The longitudinal tau PET data is from 13 AD, 42 MCI, and 72 CU in ADNI. Using cerebellar grey reference region, we calculated the difference over two time points (1.1 years ± 0.2 (0.6‐1.6)) for the entorhinal, inferior temporal and metaROI SUVR, and the difference for indices, in‐strength and out‐strength each based on the directed tau longitudinal network using predefined nodes(inferior temporal and limbic). We examined regional/network based indices in term of the group differences, their correlation with AVLT‐LTM change. In addition, we also calculated sample size for a prevention clinical trial for Aβ+/‐ subjects separately with 80% power and 25% treatment effect. Result: The longitudinal tau network measures(instrength and outstrength) are significantly different between the three groups (p<0.004) but not the SUVR change at entorhinal(p=0.62), inferior temporal(p=0.36) or tau meta ROI rates(p=0.21). In CU Aβ+ subjects, limbic outstrength significantly correlated to AVLT‐LTM rate(rs=‐0.52, p=0.013). The most significant regional value(tau metaROI) rate is not significantly correlated with AVLT LTM rate(rs=‐0.25,p=0.26). For a clinical trial, the Inferior temporal in‐out strength(net influx) requires a sample size of 584 subjects in CU Aβ+ group and a sample size of 26448 subjects in CU Aβ‐ Entorhinal tau SUVR, inferior temporal and tau metaROI SUVR needs a sample size for CU Aβ+ is 1623, 2450,2629 respectively. For CU Aβ‐ subjects, the sample size is 53537 for entorhinal SUVR, 50605 for inferior temporal SUVR and 916184 for tau metaROI SUVR Conclusion: The network based longitudinal indices provide better power for differentiating patients at different stages, for examining tau's effects on memory and for detecting a treatment effects in prevention trial. [ABSTRACT FROM AUTHOR]

Published
2020
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21. P1‐418: INDIVIDUAL‐BASED NETWORK ANALYSIS: A NOVEL APPROACH TO INVESTIGATE THE PATHOLOGICAL SPREAD OF PHF TAU USING GRAPH THEORY IN CLINICAL AND PRECLINICAL STAGES OF ALZHEIMER'S DISEASE.

Author

Protas, Hillary, Goradia, Dhruman D., Ghisays, Valentina, Luo, Ji, VanGilder, Paul S., Thiyyagura, Pradeep, Malek-Ahmadi, Michael, Lee, Wendy, Chen, Yinghua, Devadas, Vivek, Bauer, Robert, Landau, Susan M., Weiner, Michael W., Jagust, William J., Chen, Kewei, Su, Yi, and Reiman, Eric M.

Published
2019
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22. IC‐P‐173: INDIVIDUAL‐BASED NETWORK ANALYSIS: A NOVEL APPROACH TO INVESTIGATE THE PATHOLOGICAL SPREAD OF PHF TAU USING GRAPH THEORY IN CLINICAL AND PRECLINICAL STAGES OF ALZHEIMER'S DISEASE.

Author

Protas, Hillary, Goradia, Dhruman D., Ghisays, Valentina, Luo, Ji, VanGilder, Paul S., Thiyyagura, Pradeep, Malek-Ahmadi, Michael, Lee, Wendy, Chen, Yinghua, Devadas, Vivek, Bauer, Robert, Landau, Susan M., Weiner, Michael W., Jagust, William J., Chen, Kewei, Su, Yi, and Reiman, Eric M.

Published
2019
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