Anatomically interpretable deep learning of brain age captures domain-specific cognitive impairment

Proceedings of the National Academy of Sciences · 2023 · 116 citations

• Psychology
• Audiology
• Neuroscience

= 359). In individuals with MCI (54% of whom were diagnosed with dementia within 10.9 y from MRI acquisition), BA is significantly better than CA in capturing dementia symptom severity, functional disability, and executive function. Profiles of sex dimorphism and lateralization in brain aging also map onto patterns of neuroanatomic change that reflect cognitive decline. Significant associations between BA and neurocognitive measures suggest that the proposed framework can map, systematically, the relationship between aging-related neuroanatomy changes in CN individuals and in participants with MCI or AD. Early identification of such neuroanatomy changes can help to screen individuals according to their AD risk.

Staging tau pathology with tau PET in Alzheimer’s disease: a longitudinal study

Translational Psychiatry · 2021 · 65 citations

• Oncology
• Psychology
• Internal medicine

F-AV-1451 tau PET (baseline age 73.9 ± 7.7 years, 375 female) were stratified into five stages by a topographic PET staging scheme. Cognitive trajectories and clinical progression were compared across stages with or without further dichotomy of amyloid status, using linear mixed-effect models and Cox proportional hazard models. Significant cognitive decline was first observed in stage 1 when tau levels only increased in transentorhinal regions. Rates of cognitive decline and clinical progression accelerated from stage 2 to stage 3 and stage 4. Higher stages were also associated with greater CSF phosphorylated tau and total tau concentrations from stage 1. Abnormal tau accumulation did not appear with normal β-amyloid in neocortical regions but prompt cognitive decline by interacting with β-amyloid in temporal regions. Highly accumulated tau in temporal regions independently led to cognitive deterioration. Topographic PET staging scheme have potentials in early diagnosis, predicting disease progression, and studying disease mechanism. Characteristic tau spreading pattern in Alzheimer's disease could be illustrated with biomarker measurement under NIA-AA framework. Clinical-neuroimaging-neuropathological studies in other cohorts are needed to validate these findings.

Plasma phosphorylated-tau181 as a predictive biomarker for Alzheimer’s amyloid, tau and FDG PET status

Translational Psychiatry · 2021 · 68 citations

• Medicine
• Pathology
• Oncology

Plasma phosphorylated-tau181 (p-tau181) showed the potential for Alzheimer's diagnosis and prognosis, but its role in detecting cerebral pathologies is unclear. We aimed to evaluate whether it could serve as a marker for Alzheimer's pathology in the brain. A total of 1189 participants with plasma p-tau181 and PET data of amyloid, tau or FDG PET were included from ADNI. Cross-sectional relationships of plasma p-tau181 with PET biomarkers were tested. Longitudinally, we further investigated whether different p-tau181 levels at baseline predicted different progression of Alzheimer's pathological changes in the brain. We found plasma p-tau181 significantly correlated with brain amyloid (Spearman ρ = 0.45, P < 0.0001), tau (0.25, P = 0.0003), and FDG PET uptakes (-0.37, P < 0.0001), and increased along the Alzheimer's continuum. Individually, plasma p-tau181 could detect abnormal amyloid, tau pathologies and hypometabolism in the brain, similar with or even better than clinical indicators. The diagnostic accuracy of plasma p-tau181 elevated significantly when combined with clinical information (AUC = 0.814 for amyloid PET, 0.773 for tau PET, and 0.708 for FDG PET). Relationships of plasma p-tau181 with brain pathologies were partly or entirely mediated by the corresponding CSF biomarkers. Besides, individuals with abnormal plasma p-tau181 level (>18.85 pg/ml) at baseline had a higher risk of pathological progression in brain amyloid (HR: 2.32, 95%CI 1.32-4.08) and FDG PET (3.21, 95%CI 2.06-5.01) status. Plasma p-tau181 may be a sensitive screening test for detecting brain pathologies, and serve as a predictive biomarker for Alzheimer's pathophysiology.

Community of Practice Among Faculty Team-Teaching Education Doctorate (Ed.D.) Students: A Reflective Study

International journal of doctoral studies · 2021 · 8 citations

• Sociology
• Medical education
• Psychology

Aim/Purpose: The purpose of the study was to contribute to knowledge about the ways in which incorporating a Community of Practice into doctoral seminar teaching and course management could be a practical and sustainable path to professional development for doctoral faculty aspiring to become stewards of the practice of teaching. Background: This report documents a reflective self-study conducted by four professors engaged in a community of practice while team-teaching a linked pair of EdD seminars on action research at Arizona State University. Methodology: This reflective study used field notes and written reflections as its sources of data to examine how participants’ identities as professors of education changed during and after participating in a team-taught professional doctoral pair of courses. Contribution: An important goal of the community of practice was to promote faculty professional development as stewards of the practice of teaching. Engaging in disciplined reflection on teaching is uncommon in American graduate education and rarely documented in the literature of post-compulsory education. Findings: Analysis of post-hoc reflective accounts and contemporaneous notes revealed a general pattern of gradual transformation by the teaching team members. The professors moved from anxious concern about appearing competent to growing confidence and appreciation for the potential of a community of practice to provide significant professional benefits to students and faculty. Salutary features of reflective team teaching in a community of practice persist in participants’ subsequent teaching practice. Recommendations for Practitioners: Reported benefits include eagerness for team teaching, increased openness to pedagogical suggestions from peers, comfort with being observed by colleagues while teaching, and willingness to revise plans when initial plans and practices are not working effectively for students. Recommendation for Researchers: Data analysis and testimony support the claim that engaging in a CoP, in this case, did support their identity transformation as stewards of their own practice as instructors and professors of education. However, the study design does not support a claim that most or all future Communities of Practice in doctoral education will produce similar salutary results. Testing this proposition will require additional research in settings and programs different from the one represented here. Impact on Society: Implementing communities of practice in doctoral programs can make room for professional development for both the faculty team and for the students. Future Research: Further studies could be conducted to document the ways in which other communities of practice can be used to develop faculty instructors in masters and doctoral programs and in undergraduate education.