Geriatrics Commons^™

Synergistic Effects Of Plasma S100b And Mri Measures Of Cerebrovascular Disease On Cognition In Older Adults, Colleen A. Pappas, Christopher E. Bauer, Valentinos Zachariou, Timothy Justin Libecap, Beatriz Rodolpho, Tiffany L. Sudduth, Peter T. Nelson, Gregory Jicha, Anika M. S. Hartz, Xingfeng Shao, Danny J. J. Wang, Brian T. Gold

Neurology Faculty Publications

There is growing interest in studying vascular contributions to cognitive impairment and dementia (VCID) and developing biomarkers to identify at-risk individuals. A combination of biofluid and neuroimaging markers may better profile early stage VCID than individual measures. Here, we tested this possibility focusing on plasma levels of S100 calcium-binding protein B (S100B), which has been linked with blood– brain-barrier (BBB) integrity, and neuroimaging measures assessing BBB function (water exchange rate across the BBB (kw)) and cerebral small vessel disease (white matter hyperintensities (WMHs)). A total of 74 older adults without dementia had plasma samples collected and underwent cognitive assessment. A …

Exploring The Links Among Brain Iron Accumulation, Cognitive Performance, And Dietary Intake In Older Adults: A Longitudinal Mri Study, Valentinos Zachariou, Colleen A. Pappas, Christopher E. Bauer, Elayna R. Seago, Brian T. Gold

Neurology Faculty Publications

This study evaluated longitudinal brain iron accumulation in older adults, its association with cognition, and the role of specific nutrients in mitigating iron accumulation. MRI-based, quantitative susceptibility mapping estimates of brain iron concentration were acquired from seventy-two healthy older adults (47 women, ages 60–86) at a baseline timepoint (TP1) and a follow-up timepoint (TP2) 2.5–3.0 years later. Dietary intake was evaluated at baseline using a validated questionnaire. Cognitive performance was assessed at TP2 using the uniform data set (Version 3) neuropsychological tests of episodic memory (MEM) and executive function (EF). Voxel-wise, linear mixed-effects models, adjusted for longitudinal gray matter volume …

Blood Biomarkers In Down Syndrome: Facilitating Alzheimer’S Disease Detection And Monitoring, Melissa E. Petersen, Lisi Flores-Aguilar, Elizabeth Head, Laia Montoliu-Gaya, Andre Strydom, Sarah E. Pape, Juan Fortea, Nicholas J. Ashton, Chinedu Udeh-Momoh, Sid E. O’Bryant, Dwight German, Florin Despa, Mark Mapstone, Henrik Zetterberg

Neurology Faculty Publications

Blood-based biomarkers continue to be explored for disease detection, monitoring of progression, and therapeutic outcomes as the diagnostic determination of Alzheimer’s Disease in Down Syndrome (DS-AD) remains challenging in clinical settings. This perspective highlights the current status of this effort. Overall, amyloid (A), tau (T), and neurodegeneration (AT[N]) blood-based biomarkers have been shown to increase with disease pathology for individuals with DS. Phosphorylated tau biomarkers (p-tau217, p-tau181) have been consistently shown to track disease progression for DS-AD and are likely good candidates for use in clinical settings. Biomarkers of inflammation (glial fibrillary acidic protein) also show promise; however, additional work …

Parallel Electrophysiological Abnormalities Due To Covid-19 Infection And To Alzheimer’S Disease And Related Dementia, Yang Jiang, Jennifer Neal, Pradoldej Sompol, Görsev Yener, Xianghong Arakaki, Christopher M. Norris, Francesca R. Farina, Agustin Ibanez, Susanna Lopez, Abdulhakim Al-Ezzi, Voyko Kavcic, Bahar Güntekin, Claudio Babiloni, Mihály Hajós

Neurology Faculty Publications

Many coronavirus disease 2019 (COVID-19) positive individuals exhibit abnormal electroencephalographic (EEG) activity reflecting “brain fog” and mild cognitive impairments even months after the acute phase of infection. Resting-state EEG abnormalities include EEG slowing (reduced alpha rhythm; increased slow waves) and epileptiform activity. An expert panel conducted a systematic review to present compelling evidence that cognitive deficits due to COVID-19 and to Alzheimer’s disease and related dementia (ADRD) are driven by overlapping pathologies and neurophysiological abnormalities. EEG abnormalities seen in COVID-19 patients resemble those observed in early stages of neurodegenerative diseases, particularly ADRD. It is proposed that similar EEG abnormalities in …

Cerebrovascular Disease Is Associated With Alzheimer's Plasma Biomarker Concentrations In Adults With Down Syndrome, Andreas Engvig, Karl Trygve Kalleberg, Lars T. Westlye, Esten Høyland Leonardsen, Alzheimer’S Disease Neuroimaging Initiative Consortium

Neurology Faculty Publications

DNA methylation age (MA), brain age (BA), and frailty index (FI) are putative aging biomarkers linked to dementia risk. We investigated their relationship and combined potential for prediction of cognitive impairment and future dementia risk using the ADNI database. Of several MA algorithms, DunedinPACE and GrimAge2, associated with memory, were combined in a composite MA alongside BA and a data-driven FI in predictive analyses. Pairwise correlations between age- and sex-adjusted measures for MA (aMA), aBA, and aFI were low. FI outperformed BA and MA in all diagnostic tasks. A model including age, sex, and aFI achieved an area under the …

Cerebrovascular Reactivity Mri As A Biomarker For Cerebral Small Vessel Disease–Related Cognitive Decline: Multi-Site Validation In The Markvcid Consortium, Peiying Liu, Zixuan Lin, Kaisha Hazel, George Pottanat, Cuimei Xu, Dengrong Jiang, Jay J. Pillai, Emma Lucke, Christopher E. Bauer, Brian T. Gold, Steven M. Greenburg, Karl G. Helmer, Kay Jann, Gregory Jicha, Joel Kramer, Pauline Maillard, Rachel M. Mulavelil, Pavel Rodriguez, Claudia L. Satizabal, Kristin Schwab, Sudha Seshadri, Herpreet Singh, Ángel G. Velarde Dediós, Danny J. J. Wang, Rita R. Kalyani, Abhay Moghekar, Paul B. Rosenberg, Sevil Yasar, Marilyn Albert, Hanzhang Lu

Neurology Faculty Publications

INTRODUCTION: Vascular contributions to cognitive impairment and dementia (VCID) represent a major factor in cognitive decline in older adults. The present study examined the relationship between cerebrovascular reactivity (CVR) measured by magnetic resonance imaging (MRI) and cognitive function in a multi-site study, using a predefined hypothesis.

METHODS: We conducted the study in a total of three analysis sites and 263 subjects. Each site performed an identical CVR MRI procedure using 5% carbon dioxide inhalation. A global cognitive measure of Montreal Cognitive Assessment (MoCA) and an executive function measure of item response theory (IRT) score were used as outcomes.

RESULTS: CVR …

Decentralized Clinical Trials For Medications To Reduce The Risk Of Dementia: Consensus Report And Guidance, Leanne Howard, Carla Abdelnour, Erin Abner, Ricardo F. Allegri, Hiroko H. Dodge, Serge Gauthier, Camilla M. Hoyos, Gregory Jicha, Patrick G. Kehoe, Catherine J. Mummery, Adesola Ogunniyi, Nikolaos Scarmeas, Xiaoying Chen, Jodie R. Titiner, Christopher R. Weber, Ruth Peters

Neurology Faculty Publications

INTRODUCTION: Recent growth in the functionality and use of technology has prompted an increased interest in the potential for remote or decentralized clinical trials in dementia. There are many potential benefits associated with decentralized medication trials, but we currently lack specific recommendations for their delivery in the dementia field.

METHODS: A modified Delphi method engaged an expert panel to develop recommendations for the conduct of decentralized medication trials in dementia prevention. A working group of researchers and clinicians with expertise in dementia trials further refined the recommendations.

RESULTS: Overall, the recommendations support the delivery of decentralized trials in dementia prevention …

Estrogen’S Sex-Specific Effects On Ischemic Cell Death And Estrogen Receptor Mrna Expression In Rat Cortical Organotypic Explants, Amanda L. Trout, Christopher J. Mclouth, Jenna Westberry, Tomoko Sengoku, Melinda E. Wilson

Neurology Faculty Publications

Estrogens, such as the biologically active 17-β estradiol (E2), regulate not only reproductive behaviors in adults, but also influence neurodevelopment and neuroprotection in both females and males. E2, contingent upon the timing and concentration of the therapy, is neuroprotective in female and male rodent models of stroke. In Vivo studies suggest that E2 may partially mediate this neuroprotection, particularly in the cortex, via ERα. In Vitro studies, utilizing a chemically induced ischemic injury in cortical explants from both sexes, suggest that ERα or ERβ signaling is needed to mediate the E2 protection. Since we know that the timing and concentration …

Different Cohort, Disparate Results: Selection Bias Is A Key Factor In Autopsy Cohorts, Kathryn Gauthreaux, Walter A. Kukull, Karin B. Nelson, Charles Mock, Yen-Chi Chen, Kwun C. G. Chan, David W. Fardo, Yuriko Katsumata, Erin L. Abner, Peter T. Nelson

Neurology Faculty Publications

INTRODUCTION: Research-oriented autopsy cohorts provide critical insights into dementia pathobiology. However, different studies sometimes report disparate findings, partially because each study has its own recruitment biases. We hypothesized that a straightforward metric, related to the percentage of research volunteers cognitively normal at recruitment, would predict other inter-cohort differences.

METHODS: The National Alzheimer’s Coordinating Center (NACC) provided data on N = 7178 autopsied participants from 28 individual research centers. Research cohorts were grouped based on the proportion of participants with normal cognition at initial clinical visit.

RESULTS: Cohorts with more participants who were cognitively normal at recruitment contained more individuals who …

Dementia Risk Reduction: Why Haven't The Pharmacological Risk Reduction Trials Worked? An In-Depth Exploration Of Seven Established Risk Factors, Ruth Peters, John Breitner, Sarah James, Gregory A. Jicha, Pierre-Francois Meyer, Marcus Richards, A. David Smith, Hussein N. Yassine, Erin L. Abner, Atticus H. Hainsworth, Patrick G. Kehoe, Nigel Beckett, Christopher Weber, Craig Anderson, Kaarin J. Anstey, Hiroko H. Dodge

Neurology Faculty Publications

Identifying the leading health and lifestyle factors for the risk of incident dementia and Alzheimer's disease has yet to translate to risk reduction. To understand why, we examined the discrepancies between observational and clinical trial evidence for seven modifiable risk factors: type 2 diabetes, dyslipidemia, hypertension, estrogens, inflammation, omega-3 fatty acids, and hyperhomocysteinemia. Sample heterogeneity and paucity of intervention details (dose, timing, formulation) were common themes. Epidemiological evidence is more mature for some interventions (eg, non-steroidal anti-inflammatory drugs [NSAIDs]) than others. Trial data are promising for anti-hypertensives and B vitamin supplementation. Taken together, these risk factors highlight a future need …

Cognitive And Behavioral Domains That Reliably Differentiate Normal Aging And Dementia In Down Syndrome, Jordan P. Harp, Lisa M. Koehl, Kathryn L. Van Pelt, Christy L. Hom, Eric Doran, Elizabeth Head, Ira T. Lott, Frederick A. Schmitt

Neurology Faculty Publications

Primary care integration of Down syndrome (DS)-specific dementia screening is strongly advised. The current study employed principal components analysis (PCA) and classification and regression tree (CART) analyses to identify an abbreviated battery for dementia classification. Scale- and subscale-level scores from 141 participants (no dementia n = 68; probable Alzheimer’s disease n = 73), for the Severe Impairment Battery (SIB), Dementia Scale for People with Learning Disabilities (DLD), and Vineland Adaptive Behavior Scales—Second Edition (Vineland-II) were analyzed. Two principle components (PC1, PC2) were identified with the odds of a probable dementia diagnosis increasing 2.54 times per PC1 unit increase and by …

Longitudinal Assessment Of Dementia Measures In Down Syndrome, Lisa Mason Koehl, Jordan P. Harp, Kathryn L. Van Pelt, Elizabeth Head, Frederick A. Schmitt

Neurology Faculty Publications

Introduction: Early detection of dementia symptoms is critical in Down syndrome (DS) but complicated by clinical assessment barriers. The current study aimed to characterize cognitive and behavioral impairment using longitudinal trajectories comparing several measures of cognitive and behavioral functioning.

Methods: Measures included global cognitive status (Severe Impairment Battery [SIB]), motor praxis (Brief Praxis Test [BPT]), and clinical dementia informant ratings (Dementia Questionnaire for People with Learning Disabilities [DLD]). One-year reliability was assessed using a two-way mixed effect, consistency, single measurement intraclass correlation among non-demented participants. Longitudinal assessment of SIB, BPT, and DLD was completed using linear mixed effect models.

Results: …

Brain Structure Changes Over Time In Normal And Mildly Impaired Aged Persons, Charles D. Smith, Linda J. Van Eldik, Gregory A. Jicha, Frederick A. Schmitt, Peter T. Nelson, Erin L. Abner, Richard J. Kryscio, Richard R. Murphy, Anders H. Andersen

Neurology Faculty Publications

Structural brain changes in aging are known to occur even in the absence of dementia, but the magnitudes and regions involved vary between studies. To further characterize these changes, we analyzed paired MRI images acquired with identical protocols and scanner over a median 5.8-year interval. The normal study group comprised 78 elders (25M 53F, baseline age range 70-78 years) who underwent an annual standardized expert assessment of cognition and health and who maintained normal cognition for the duration of the study. We found a longitudinal grey matter (GM) loss rate of 2.56 ± 0.07 ml/year (0.20 ± 0.04%/year) and a …

Post-Acquisition Processing Confounds In Brain Volumetric Quantification Of White Matter Hyperintensities, Ahmed A. Bahrani, Omar M. Al-Janabi, Erin L. Abner, Shoshana H. Bardach, Richard J. Kryscio, Donna M. Wilcock, Charles D. Smith, Gregory A. Jicha

Neurology Faculty Publications

BACKGROUND: Disparate research sites using identical or near-identical magnetic resonance imaging (MRI) acquisition techniques often produce results that demonstrate significant variability regarding volumetric quantification of white matter hyperintensities (WMH) in the aging population. The sources of such variability have not previously been fully explored.

NEW METHOD: 3D FLAIR sequences from a group of randomly selected aged subjects were analyzed to identify sources-of-variability in post-acquisition processing that can be problematic when comparing WMH volumetric data across disparate sites. The methods developed focused on standardizing post-acquisition protocol processing methods to develop a protocol with less than 0.5% inter-rater variance.

RESULTS: A series …