Citations

Abstract Background To promote equitable access to neurologic diagnostics, our team developed MASTERMIND—the Mobile Assessment of Speech To Evaluate, Recognize, and Monitor Indicators of Neurologic health and Disease. One subtest, the MASTERMIND Assessment of Naming, includes ten pictures randomly selected from a list of 45 words varying in frequency. This study aimed to 1) evaluate the feasibility of a remotely self‐administered naming test for patients with cognitive, linguistic, and/or communication difficulties and 2) assess the sensitivity and specificity of performance measures (accuracy, error type, and response time) for detecting aphasia and cognitive‐communication difficulties. Method The task was remotely administered to 138 controls, 26 cognitively impaired individuals, 15 with motor speech disorders, 8 with cognitive concerns, and 6 with aphasia. Participants named pictures displayed on‐screen, advancing through the task by clicking “Next.” Responses were processed using natural language processing (NLP). Audio was transcribed with Whisper Large‐v3, and responses were matched to stimuli within a 0.4‐second threshold. Errors were categorized by type (semantic, phonemic, or unclear source) through consensus between two raters. Performance metrics (accuracy, error type, response time) were analyzed using Kruskal‐Wallis and Pearson's Chi‐Square tests, with AUROC analysis evaluating diagnostic performance. Results Differences in accuracy, response time, and error type were observed across groups (Table 1). Controls and cognitively impaired participants performed similarly, with longer response times observed in patients with aphasia and motor speech disorders. Accuracy alone was a poor predictor of all patients versus controls (AUROC = 0.468) but prediction was better in distinguishing aphasia patients from 1) controls (AUROC = 0.698), 2) cognitively impaired participants (AUROC = 0.679), and 3) those with MSDs (AUROC = 0.670). Conclusions The MASTERMIND Assessment of Naming is a feasible, scalable, self‐administered diagnostic tool enhanced by automated NLP. It provides critical insights through response time, accuracy, and error analysis. Limitations include potential bias in error classification and fixed processing thresholds. The study highlights MASTERMIND's potential for patient triaging and screening. Future research will evaluate the sensitivity of combined performance metrics to disease progression, expand sample sizes and diversity, and refine usability based on participant feedback.

Abstract This presentation will first provide an overview of the rationale behind this Perspective Session bringing the Atypical Alzheimer's disease (AD) and Clinical Trials ISTAART Professional Interest Area (PIAs) together. We will then highlight foundational notions about atypical forms of Alzheimer's disease (AD) and critical shortcomings in current clinical trial designs that fail to address the unique needs of these populations. We will first briefly describe the distinct clinical and biological features of atypical AD variants, including posterior cortical atrophy (PCA), logopenic variant primary progressive aphasia (lvPPA), dysexecutive AD (dAD), and behavioral AD (bvAD). These variants are typically characterized by early‐onset symptoms and predominant non‐memory impairments, factors that have contributed to the significant underrepresentation of these patients in large‐scale clinical trials. Special attention will be given to recent FDA‐approved amyloid‐targeting therapies, which have largely focused on the “typical” amnestic, late‐onset presentation of AD, further underscoring the urgent need for inclusive research efforts for the broader phenotypic spectrum of the disease. We will identify critical gaps in clinical trial design for atypical AD and propose early strategic avenues to address these challenges. Key considerations include optimizing enrollment strategies, developing syndrome‐specific biological and clinical endpoints, and fostering advocacy to promote accurate diagnosis, equitable representation, and improved outcomes for these underrepresented populations.

Abstract Context Evidence on the evolution of cardiometabolic comorbidities following surgical remission of hypercortisolism is scarce. Objective To determine the impact of surgical remission on cardiometabolic comorbidities in patients with endogenous hypercortisolism and to identify factors associated with cardiometabolic improvement. Methods Prospective single-center cohort study (2019-2025) of adults with Cushing syndrome (CS) or mild autonomous cortisol secretion (MACS) with surgical remission of hypercortisolism. Outcomes included (1) changes in severity of hypertension, diabetes mellitus (DM), hyperlipidemia, and obesity between baseline, 3, and 12 months postremission and (2) factors associated with improvement in comorbidities. Results Among 357 patients (49% MACS, 36% pituitary CS, 10% adrenal CS, 5% ectopic CS; median age 53 years [interquartile range 42-62]; 81% women), 336 (94%) had hypertension, 241 (68%) had obesity, and 122 (35%) had DM. At a median of 12 months postsurgery, improvement in hypertension occurred in 70% (90/128) of patients with CS and 51% (60/117) of patients with MACS, DM in 90% (46/51) patients with CS and 37% (13/35) patients with MACS, and obesity in 79% (77/97) patients with CS and 20% (14/71) patients with MACS. In a multivariable analysis, higher baseline biochemical severity scores were associated with improvement in hypertension [odds ratio (OR) 1.3, 95% confidence interval (CI) 1.1-1.5), DM (OR 2.5, 95% CI 1.7-4.1), and obesity (OR 1.5, 95% CI 1.2-1.8) at a median of 12 months postremission of hypercortisolism. Conclusion Postsurgical improvement of cardiometabolic comorbidities was observed in both patients with CS and MACS. Higher baseline biochemical severity scores were associated with higher postremission improvement in comorbidities.

Abstract Background The rare APOE3 ‐Christchurch ( APOE3Ch ) variant is associated with remarkable protective effects, delaying the age at onset of PSEN1 ‐E280A driven autosomal dominant Alzheimer's disease (AD). While much of the research on APOE3C h has focused on its role in AD, little is known about how this variant impacts APOE biology under non‐disease conditions. Using cortical organoids as a model system, we aim to investigate the fundamental mechanisms by which APOE3Ch alters APOE biology, including its effects on metabolism and cellular interactions, to better understand its unique properties and potential implications for broader applications. Method Cortical organoids were derived from the isogenic neurodegeneration iPSC line series, with either the APOE3 or APOE3Ch genotype. Single‐cell RNA sequencing (scRNA‐seq) was performed on three independent batches of 6‐month‐old cerebral organoids to identify pathways differentially regulated by APOE3Ch. To further investigate APOE lipidation and its effects on lipid metabolism, lipidomics analysis was conducted on 8‐month‐old cerebral organoids, offering additional insights into APOE3Ch ‐specific biological mechanisms. Validation was also carried out using iPSC‐derived astrocytes and neurons to confirm key findings. Result ScRNA‐seq revealed differences in cell populations and astrocyte subtypes between APOE3 and APOE3Ch organoids, with mitochondrial‐related pathways differentially regulated in APOE3Ch cerebral organoids. These findings were validated in iPSC‐derived astrocytes. APOE3Ch iPSC‐derived astrocytes exhibited increased APOE secretion compared to APOE3 . They also demonstrated enhanced mitochondrial function, as evidenced by increased spare respiratory capacity measured by Seahorse stress assays. Furthermore, APOE3Ch astrocytes showed reduced lipid droplet formation following oleic acid treatment. Lipidomics analysis of APOE3Ch cerebral organoids revealed decreased cholesterol ester levels, suggesting alterations in lipid metabolism. Conclusion Our findings provide novel insights into how the APOE3Ch variant alters APOE biology, revealing differences in mitochondrial function and lipid metabolism. The differential regulation of mitochondrial pathways in APOE3Ch cerebral organoids, along with the enhanced mitochondrial capacity and altered lipid metabolism observed in APOE3Ch astrocytes, highlights the unique properties of this variant. These results offer valuable mechanistic understanding that may inform future therapeutic strategies targeting APOE biology, particularly in the context of AD.

Abstract Background Diffusion MRI (dMRI) measures are increasingly being used as biomarkers for aging and dementia in multi‐center studies. Measurements in longitudinal studies are often acquired on different systems, which can result in systematic differences of machine origin (e.g. vendor, hardware, algorithms). This may warrant harmonization prior to pooling multi‐site data. However, harmonization algorithms may introduce a risk of removing valuable information content and reducing sensitivity to physiological factors (e.g. sex, age, disease). Here, we tested the hypothesis that protocol standardization may minimize machine‐origin differences, obviating a need for post‐acquisition harmonization in a two‐site (Mississippi‐MS and Minnesota‐MN) cohort of the longitudinal Mayo Clinic Study of Aging (MCSA). Methods Two data sets were analyzed: first, a crossover dataset with 80 participants (scanned within 2 days) bridging two different protocols on GE and Siemens scanners; second, participants scanned using standardized protocols from the ongoing MCSA ( N MN‐MCSA =204; N MS‐MCSA =52). Parameters are listed in Figure 1. For crossover data, analyses were repeated with GE data resampled to 2‐mm isotropic resolution, and discarding Siemens‐only b‐shells to artificially reduce protocol disparities. Analysis encompassed visualization of overlain subjectwise histogram‐derived densities obtained from whole‐brain masks for dMRI measures; and median dMRI measures from within the genu of the corpus callosum (GCC) with nonparametric statistical testing. When available, both DTI and NODDI measures were compared. Results Pronounced visual distributional differences seen between MD and FA in crossover data were reduced with resampling of GE data and including only b‐shells shared across acquisitions. For the resampled/reshelled data, significant differences remained for all GCC‐FA comparisons, but not all GCC‐MD (Figure 2). For the ongoing MCSA data from two sites, MD and FA whole‐brain densities were more closely aligned, with GCC‐FA and GCC‐MD showing no significant differences (Figure 3). NODDI measures showed more discordant densities than DTI measures, including shifts in most probable values and differences in distributional arrangement. Conclusions Our work provides further evidence supporting protocol and processing standardization for minimizing machine‐origin differences prior to considering harmonization. Differences in dMRI metrics seen when comparing across unstandardized protocols were reduced when protocols were standardized. NODDI metrics had more apparent sensitivity to site than DTI measures.

Abstract Background The last several decades have seen intense research into Alzheimer’s disease (AD) resulting in several current and emerging disease modifying treatments that target hallmarks of the AD pathology. Previous evidence has indicated that neurologists and primary care physicians (PCPs) frequently lack knowledge of the most recent findings pertaining to the use of biomarkers and antibody‐based therapies in AD. An online CME program was developed to educate neurologists and PCPs on biomarker and therapeutic data in AD from a 2024 dementia conference. Method The online CME activity consisted of a chapterized 30‐minute video presentation featuring dementia specialists who reviewed data from a 2024 dementia conference on biomarkers or therapeutics. Educational effect was assessed by comparing a matched sample of responses to four identical questions presented before and directly after exposure to the intervention. A paired samples t‐test assessed the number of correct responses and for confidence rating; McNemar’s test was used to identify significant differences between pre‐ and post‐assessment question responses. Cohen’s d was used to calculate the effect size of the online education. Data were collected between August 2024 and October 2024. Result A moderate educational effect was observed for both neurologist ( n =88; d =.77, p <0.001) and PCP ( n =141; d =.75, p <.001) learners. Both physician groups demonstrated significant (P <.05) pre‐ vs post‐educational improvements on the following: clinical data on AD diagnostic accuracy comparing blood‐based biomarker testing to a clinical diagnosis made by a physician and risk factors for amyloid‐relating imaging abnormalities associated with an approved anti‐amyloid therapy (AAT). PCPs, but not neurologists, demonstrated a pre‐post educational improvement on a question about outcomes from an open‐label extension study of an approved ATT. Participation in the activity resulted in 44% of neurologists and 48% of PCPs reporting an increase in confidence regarding their ability to apply the latest clinical data on approved AATs in clinical practice. Conclusion The results indicated that a CME‐certified 30‐minute video program was effective at improving knowledge among a diversity of physician learners regarding emerging data from a recent medical conference. Future CME should continue to highlight impactful new data released at medical conferences.

Abstract Background Use of software to “de‐face” research brain images has grown as advances in automated face recognition have made it increasingly possible to re‐identify participants. Imaging studies of Alzheimer's Disease and related diseases have included more participants from historically underrepresented groups, but de‐facing software have primarily been validated using images from mostly non‐Hispanic White participants, and its performance has not been directly compared across ethnoracial groups. Method From The Health and Aging Brain Study: Health Disparities (HABS‐HD) study, we constructed a sample of 305 T1‐weighted MRI from HABS‐HD baseline visits, matched across three ethnoracial groups (non‐Hispanic White (NHW, n = 104), non‐Hispanic African American (AA, n = 104), Mexican American (MA, n = 97)) according to age‐decade, sex, cognitive status (impaired/unimpaired), and MRI scanner model. We ran mri_reface 0.3.5 on each image, and we ran FreeSurfer 7.4.1 on each unmodified image and on each de‐faced output. We then compared regional gray matter (GM) volume and cortical thickness measurements by subtracting each de‐faced image measurement from the corresponding unmodified image measurement. We compared these differences between de‐faced and unmodified images across the three matched groups using GLM analyses adjusted for age, sex, and cognitive status, and Bonferroni corrected. Result When aggregating across all brain regions, differences in cortical thickness measures due to de‐facing were significantly different between the NHW and MA groups, and between AA and MA, but not between NHW and AA (Figure 1). Differences between these group means were <0.005mm. For GM volume, differences were significant between AA and MA (magnitude < 0.2%), but not between NHW and AA or NHW and MA (Figure 2). Examining each region individually (Figure 3), cortical thickness differences were significant for only 4 regions (all with magnitudes <0.03mm), and GM volume differences were significant for only 6 regions (all with magnitudes <2%). Conclusion Effects of mri_reface on FreeSurfer brain measurements were significantly different across ethnoracial groups. Our future work will optimize mri_reface to eliminate these differences. However, the magnitudes of these differences are sufficiently small that they are unlikely to have a practical effect on analyses of data using current versions.

Abstract Background Individuals with spinal cord injury (SCI) are known to have high rates of cardiovascular disease that have traditionally been attributed to inability to engage in adequate intensity exercise. However, individuals with SCI also commonly experience instability in blood pressure. Blood pressure fluctuations are known to contribute to cardiovascular disease in other conditions, though this relationship in SCI is unknown. Objective To evaluate correlations between a clinical history of symptomatic blood pressure instability and objective evidence of vascular endothelial dysfunction in individuals with SCI. Design Case control. Setting Academic medical center. Participants Twenty‐four individuals with SCI, 14 uninjured controls of matched age, gender, and body mass index. Interventions Not applicable. Main Outcome Measures Symptomatic blood pressure instability was measured by the Autonomic Dysfunction Following SCI (ADFSCI) survey. Vascular endothelial dysfunction was quantified by ultrasound recordings of brachial flow mediated dilation following 5 minutes of forearm arterial occlusion. Results Total ADFSCI scores were significantly higher in individuals with SCI compared to controls (41.0 vs. 9.0, p = .002). Both percentage of brachial flow mediated dilation and consensus recommended allometrically scaled percentage of flow mediated dilation were significantly less in individuals with SCI ( p < .001 for both), demonstrating greater vascular dysfunction. More symptoms of blood pressure instability on the ADFSCI survey were correlated with more objective evidence of vascular dysfunction ( R 2 = 0.24, p = .03) for individuals with SCI. This relationship was not seen in uninjured controls. Conclusions In individuals with SCI, more severe symptoms of blood pressure instability are significantly correlated with more severe vascular endothelial dysfunction, making management of orthostatic hypotension and autonomic dysreflexia both high potential, modifiable risk factors for individuals with SCI to mitigate cardiovascular disease.

Abstract Background Apolipoprotein E (apoE) facilitates the fibrillization and deposition of amyloid β (Aβ) in Alzheimer's Disease (AD). Supported by robust literature from various groups, in our current study we have investigated the relative amyloidogenic properties of the three major human APOE alleles. Knowledge from such studies could provide insight into the role of ApoE protein in the deposition, evolution and maturation of parenchymal Aβ. Method We used hAbetaSAA (Jax Labs) mice crossed with human APOE targeted replacement mice to create hAbetaSAA mice homozygous for human APOE E2, E3 and E4 . Furthermore, APPsi mice (hAPPswe/indiana: Borchelt) expressing human APOE E3 or E4 were injected intracerebrally with AD brain lysates to examine the role of APOE genotype on Aβ seeding. Neuropathological examination was conducted via immunohistochemistry, immunofluorescence and immunoblotting. Result hAbetaSAA mice expressing human APOE E4 showed higher Aβ deposition relative to APOE E3 and APOE E2 by 5 months of age and progressing through 8 months and 13 months of age. In comparison, APP mice expressing humanized Aβ (Jax Labs) with human APOE E4 did not develop deposits in their lifetime. hAbetaSAA mice with endogenous mouse Apoe had the highest Aβ plaque deposition, with an approximately 60‐fold increase in Aβ burden compared to SAA APP mice expressing APOE E3 , especially in the earlier deposition phase. Removing mouse Apoe resulted in dose‐dependent reduction in Aβ deposition, consistent with previously published literature. Plaque morphology did not show any notable differences between APOE genotypes, and colocalization of apoE with Aβ were relatively equivalent across different APOE genotypes. Further, in the APPsi model seeded with AD‐derived seeds, we found that mice with APOE E4 or APOE E3 developed equal burdens of diffuse parenchymal Aβ, with no detectable changes in plaque morphology. Conclusion We conclude that apoE variants broadly influence the rate of amyloid deposition, but do not modify the morphology of the resulting deposits or colocalization with Aβ. Notably, when seeding with AD patient brain lysate, there was no significant difference in Aβ burden between APPsi mice expressing APOE E3 and E4 . Our study adds insights into the role of apoE isoforms in determining Aβ‐related phenotype.