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AbstractBackgroundHigher blood pressure (BP) is associated with greater white matter hyperintensity (WMH) volume, but research is limited in recently menopausal and postmenopausal women. Postmenopausal women have a greater burden of WMH than men and premenopausal women, but whether hormone therapy (HT) modifies the association between systolic and diastolic BP (SBP, DBP) and WMH is unknown. We investigated the association of SBP and DBP in recently postmenopausal women who participated in an HT trial with WMH volumes measured 14 years later and explored whether HT modified the results.MethodWomen with good cardiovascular (CV) health, who were previously enrolled in a randomized placebo‐controlled HT trial, the Kronos Early Estrogen Prevention Study (KEEPS), participated in the current observational KEEPS continuation (n = 212; median age = 67; range 58‐72). SBP and DBP were measured at KEEPS baseline (median age = 54 years; range 44‐59) and continuation. Antihypertensive users were excluded (baseline, n = 34; continuation, n = 61). Approximately 10 years after the end of KEEPS HT versus placebo 4‐year interventions, automated WMH volumes were measured from 3D‐FLAIR MRI. Associations of KEEPS baseline and continuation SBP and DBP with log WMH volume at KEEPS continuation were tested using linear regression analyses adjusting for covariates in model 1 (age, total intracranial volume, study site) and model 2 (model 1 plus cardiovascular risk factors (CVRF)).ResultHigher KEEPS baseline SBP and DBP were associated with greater WMH volume measured 14 years later, and after adjusting for CVRF (p≤0.01). Similarly, in KEEPS continuation, higher SBP and DBP were associated with greater WMH volume measured concurrently and after adjusting for CVRF (p<0.001). We did not find statistically significant evidence that HT versus placebo modified these associations. Topographically, higher SBP and DBP were associated with greater periventricular WMH in the frontal and parietal lobes after adjusting for age (Figure).ConclusionHigher SBP and DBP in recently menopausal women with good CV health were associated with greater WMH volumes more than a decade later after adjusting for CVRF, independent of randomization to HT. Our results show the importance of blood pressure control in recently menopausal women, that may reduce the white matter injury later in life.

AbstractBackgroundAlthough amyloid deposition in the brain is often associated with subsequent dementia risk, not everyone with brain amyloid will develop dementia. This discrepancy illustrates the potential importance that risk factors and lived experiences may have in modifying this association. Compared to participants with low social engagement (SE) in mid‐life, we hypothesized that participants with high mid‐life SE will show a weaker association between amyloid burden and incident dementia.MethodWe included data from 310 non‐demented participants of the Atherosclerosis Risk in Communities (ARIC)‐PET study. Social support and isolation were assessed via interviewer‐administered questionnaires (Visit 2; 1990 – 1992). Based upon categorization of both factors, participants were classified as having high, intermediate, or low mid‐life SE (Table 1). Brain amyloid was evaluated with florbetapir PET (Visit 5; 2011‐2014). Elevated amyloid burden was defined as standardized uptake value ratio (SUVR) >1.2 in the global cortex. Incident dementia cases were identified from visit 5 through 2019 through ongoing surveillance utilizing in‐person neurocognitive testing, informant interviews, and hospitalization codes. Relative contributions of mid‐life SE and elevated florbetapir SUVR to incident dementia, independently and with multiplicative interaction terms, were evaluated with Cox regression models, adjusted for demographics, APOEε4 and vascular risk factorsResultAmong 310 participants, 48 developed dementia (median follow‐up: 4.7 years). Mid‐life SE and elevated SUVR each independently predicted dementia risk but did not interact on a multiplicative scale. Participants with high or intermediate mid‐life SE, relative to low mid‐life SE, were less likely to develop dementia (Table 2). Although the interaction between mid‐life SE and elevated SUVR was not significant, stratified models suggested a stronger association between amyloid burden and dementia in participants with high mid‐life SE (Table 3).ConclusionGreater mid‐life SE was associated with lower odds of developing dementia, independent of elevated SUVR. Although protective, there was no strong evidence for effect modification of mid‐life SE on the association between amyloid and dementia risk. Future longitudinal studies evaluating the potential influence of social factors measured throughout the life course are needed to inform our understanding as to what factors may preserve cognition in the presence of elevated brain pathology.

AbstractBackgroundNo specific clinical rating scale currently exists for Lewy body dementia (LBD). Clinical rating scales developed for other diseases are therefore used instead for LBD clinical trials. However, these scales are not optimized for LBD and may not sufficiently reflect the complex array of LBD‐related phenomenology, making it more difficult to interpret outcome data from LBD clinical trials.MethodA working group comprised of 14 members bridging various international LBD‐focused research groups was convened to develop the first iteration of the LBD‐DRS with a focus on inclusion of key LBD related symptom domains, ensuring that any scale is mapped to regulatory expectations, and an emphasis on being patient‐centered. This draft was then subsequently presented to a broader stakeholder group (»50 participants) at the International Lewy body Dementia Conference in June 2022 for further feedback, leading to a further iteration of the scale.ResultThe LBD‐DRS has been designed to capture ratings of the frequency and severity of symptoms across the key domains relevant to LBD – cognitive, neuropsychiatric, motor, autonomic and sleep – as well as the functional impact and perceived burden of symptoms for patients and their care partners. An international Delphi exercise is now planned with many LBD‐relevant stakeholders, which will be coupled with workgroup engagement (for example, with patient‐caregiver groups) to further develop the scale with the resulting final draft anticipated for pilot use in the near future.ConclusionsIn this presentation we will elaborate on the development of the scale, key areas that it will cover as well as challenge points and next steps. Upon completion of the development and refinement of the LBD‐DRS, we propose that this scale will have utility as valid and LBD specific outcome measure in LBD clinical trials.

AbstractBackgroundThe accumulation of the amyloid‐β (Aβ) aggregates in the brain is a key pathological event in the development of Alzheimer’s disease (AD). The α‐secretase ADAM10 is responsible for cleavage of the amyloid precursor protein (APP) through a non‐amyloidogenic pathway, thereby preventing the generation of pathogenic Aβ in the brain. Secreted frizzled related protein‐1 (sFRP1), an endogenous antagonist of Wnt signaling, has recently been identified as a key negative modulator of ADAM10. Importantly, proteomic studies reveal that unregulated sFRP1 is one of the top Aβ‐correlated proteins in the human AD brains.MethodsWe determined the therapeutic potential of specific sFRP1 WAY316606 in the N2a/APP695swe cells and patient‐specific iPSC‐derived cerebral organoids.ResultsWe herein demonstrated that treatment of sFRP1 inhibitor WAY316606 resulted in augmentation of ADAM10 activity, upregulation of soluble APP‐α (sAPPα) production, and inhibition of Aβ generation in the N2a/APP695swe cells. Moreover, WAY316606 significantly enhanced ADAM10 activity, decreased Aβ production and inhibited tau phosphorylation in human AD patient‐specific iPSC‐derived cerebral organoids.ConclusionOur findings indicate that sFRP1 is a promising therapeutic target for AD.

AbstractBackgroundAlzheimer’s Disease (AD) has no cure. We showed that partial inhibition of mitochondrial complex I (MCI) with small molecule CP2 induced adaptive stress response activating multiple neuroprotective mechanisms. Chronic treatment reduced inflammation, improved synaptic and mitochondrial functions, and blocked neurodegeneration in symptomatic APP/PS1 mice, a translational model of AD.MethodsAnalysis of mitochondrial morphology and mitochondria‐endoplasmic reticulum (ER) contacts (MERCS) was done in the hippocampal CA1 tissue from APP/PS1 mice treated with CP2 and compared to APP/PS1 and non‐transgenic mice treated with vehicle using serial block‐face scanning electron microscopy (SBFSEM) and three‐dimensional (3D) EM reconstructions combined with western blot analysis and next generation RNA sequencing.ResultsWe demonstrate that CP2 treatment restores mitochondrial morphology and mitochondria‐ ER communication, reducing ER stress in the APP/PS1 mouse brain. Using 3D EM reconstructions, we found that mitochondria in AD dendrites existed primarily as mitochondria‐on‐a‐string (MOAS), a morphological phenotype that is difficult to detect using conventional 2D EM or fluorescence spectroscopy. Compared to other morphological phenotypes, MOAS are extensively enveloped in the ER membranes forming multiple MERCS known to contribute to abnormal lipid and calcium homeostasis, and ER stress in AD. CP2 treatment specifically reduced MOAS formation, consistent with improved energy homeostasis in the brain, with concomitant reduction in MERCS, ER stress, and improved lipid homeostasis.ConclusionsThese data provide novel information on the role MOAS play in AD. Our data demonstrate that in response to energetic stress, mitochondria in dendrites acquire MOAS phenotype with increased interaction with the ER, which may synergistically contribute to the AD development. Since CP2 treatment alleviated the ER stress and improved mitochondrial dynamics and function, these data further support the development of partial MCI inhibitors as disease modifying strategy for AD.

AbstractBackgroundMixed model repeated measures (MMRM) is the most common analysis approach in clinical trials for Alzheimer’s disease. The model treats time as a categorical variable, which can be problematic when assessments occur off‐schedule, as including off‐schedule visits can induce bias, and excluding them ignores valuable information and violates the intention to treat principle. This problem has been exacerbated by clinical trial visits which have been delayed due to the COVID19 pandemic. Since MMRM entails a mean parameter for each group and visit, the model can be inefficient for longer trials of Preclinical Alzheimer’s. As an alternative to MMRM, we propose a constrained longitudinal data analysis with natural cubic splines that treats time as continuous and uses test version effects to model the mean over time.MethodWe use model selection techniques to compare the predictive value of spline models to slope models, MMRM, and models that assume a proportional treatment effect using data from several completed trials. These trials include the ADCS trial of donepezil in MCI, trials of intranasal insulin and a fyn kinase inhibitor in mild Alzheimer’s dementia, and the A4 trial of solanezumab in Preclinical Alzheimer’s. Simulation studies assess the power and Type I error of these models for trials in Preclinical Alzheimer’s, MCI, and mild dementia.ResultThe spline model with ADAS‐Cog version effect attained the best predictive value for the trials in mild dementia. The proportional model was preferred for the trial in MCI, but the proportional effect assumption was violated, and the treatment effect estimate was in the wrong direction. Considering that the spline with two degrees of freedom and version effect provide fits that are similar to MMRM in Figure 1, we concluded that two degrees of freedom appear to be sufficient to capture enough of the general trend to assess the treatment effect. AIC results from the A4 Study will be considered and included after the study is completed in Spring 2023.ConclusionThe spline model is shown to have better predictive value and precision in real datasets and has better power and Type I error control in a variety of simulation scenarios.

Abstract Background The ALLFTD (ARTFL‐LEFFTDS Longitudinal Frontemporal Lobar Degeneration) study is an NIH‐funded effort to prepare for clinical trials in sporadic (s‐FTLD) and familial (f‐FTLD) FTLD syndromes by characterizing cohorts, developing new clinical trial outcome measures, and evaluating disease progression. ALLFTD represents the merger and continuation of two prior studies: Advancing Research and Treatment of Frontotemporal Lobar Degeneration (ARTFL) and Longitudinal Evaluation of Familial Frontotemporal Dementia Subjects (LEFFTDS). Methods ALLFTD recruits participants with FTLD spectrum disorders (bvFTD, svPPA, nfvPPA, FTD‐ALS, CBS or PSP), with strong family histories of FTLD, or known FTLD‐associated genetic variants within the family. 26 sites in North America enroll participants for clinical and neuropsychological evaluations, MR Imaging, blood draws, and CSF collection in willing participants; participants are requested to return annually for follow‐up evaluation. All participants are genotyped for dementia‐associated mutations. Participants also enroll in the FTD Disorders Registry for follow‐up surveys. A subset of participants undergo remote assessment via the ALLFTD app. Visits conducted under ARTFL and LEFFTDS are included in the ALLFTD dataset. Results ALLFTD has been successful in developing methods to conduct remote or hybrid visits and in actively evaluating participants. Since ALLFTD began in January 2020, 1034 participants (736 new; 298 previously enrolled in ARTFL or LEFFTDS) have been evaluated in the longitudinal arm; an additional 119 participants have been participated in a shortened, biofluid‐focused visit. 349 have returned for follow‐up visits. Including prior participants, the ALLFTD dataset contains 3871 visits from 2343 individuals. 1277 people have sporadic syndromes; 1045 were enrolled as familial. Among s‐FTLD, bvFTD is the most common phenotype (32.8%) followed by PSP (15.9%). 61.4% of f‐FTLD participants were clinically normal at first visit; bvFTD is the most common syndrome in symptomatic f‐FTLD (40%). 477 are confirmed carriers of FTLD‐associated genetic mutations. MRIs were obtained for 2594 visits; 3492 visits have associated blood biospecimens banked; 978 visits have associated CSF samples. Conclusions The ALLFTD consortium is actively evaluating participants across North America to better characterize FTLD syndromes and support the planning and development of FTLD clinical trials. Longitudinal datasets including clinical, genetic, and imaging data are available by request.

AbstractBackgroundPerturbations in immune pathways are strongly associated with Alzheimer’s disease. A positive association between autoimmune diseases and frontotemporal dementia has been reported. We explored whether early onset Alzheimer’s disease (EOAD) would associate with autoimmune diseases.MethodWe compared 313 patients with EOAD from the Mayo Clinic Florida, Alzheimer’s Disease Research Center (ADRC) Registry with matched cognitively normal controls (NC) based on age (+/‐ 2 years) and gender at 1:2 ratio. NC were derived from Mayo Clinic Biobank Project, Rochester (N = 313) and the Mayo Clinic Study of Aging (N = 313). Data abstraction was performed by trained statisticians using ICD 9&10 codes corresponding to 40 specified autoimmune diseases and/or documentation of specified immunomodulatory treatment. Data was also abstracted via retrospective record review. We further reviewed clinical records from EOAD patients with neuropathologically confirmed Alzheimer’s disease patients enrolled in the ADRC (n = 10). Each autoimmune disease type was compared between cases and controls using Fisher’s exact test. All tests were two‐sided with alpha level set at 0.05 for statistical significance. Continuous variables were summarized as median (range) while categorical variables were reported as frequency (percentage). The prevalence of autoimmune disease in the general population was based off Hayter & Cook, 2012 and Roberts & Erdei, 2020. All data abstraction was done blinded to the clinical diagnosis and baseline demographics.ResultAutoimmune disease history was abstracted from 949 patient records (313 EOAD, 10 pathologically‐confirmed EOAD, 626 NCI). The median age was 57 years‐old. (EOAD range 28,65 yrs.; NC 30,66 yrs.). Autoimmune thyroiditis (p = 0.0008), ulcerative colitis (p = 0.011, psoriasis (<0.0001), rheumatoid arthritis (p = 0.0005), and Raynaud’s syndrome (p = 0.0021) were less prevalent in patients with EOAD compared to NC. Furthermore, patients with EOAD had a lower prevalence of immune mediated hematologic disorders.ConclusionPatients with EOAD have a lower prevalence of autoimmune diseases than NC. Immune activation identified in early onset AD patients may be unrelated to autoimmunity. Findings should be explored in late onset AD patients.

AbstractBackgroundFrontotemporal Dementia (FTD) patients are geographically dispersed and often have behavioral and/or motor deficits that limit access to in‐person clinical trials and research. To address these participation barriers, we investigated the feasibility of installing in‐home sensor technologies to remotely assess everyday functioning in FTD.MethodWe aimed to recruit 20 FTD participants with a variety of clinical syndromes, including behavioral variant FTD (bvFTD), primary progressive aphasia (PPA), corticobasal syndrome (CBS), and progressive supranuclear palsy (PSP). We also aimed to enroll a study partner for each participant that lived in the same home to serve as a control. The Collaborative Aging Research Using Technology (CART) platform was installed in participants’ homes to collect continuous data for up to two years, using motion sensors, physiological monitoring devices (e.g., scales, sleep sensors), electronic pillboxes, and wearable actigraphs. Computer use and driving patterns were also tracked. Technology was installed either via a study coordinator visit or remotely through video and written instructions, based on schedule and logistics. Participants were asked to complete a weekly Qualtrics survey about time away from home, visitors, and health changes.ResultOf the 159 UCSF participants available for recruitment through ALLFTD and other FTD projects, 28% (N = 45) met inclusion criteria. Of those 45, ten were ineligible due to advanced disease severity or relocation to an assisted living facility. A third (36%, N = 17) declined due to overwhelmed study partners (N = 3), declined any subproject participation (N = 7), sensitivity to participant’s diagnosis (N = 2), or lack of response (N = 5). Two additional participants were recruited through UCLA’s ALLFTD cohort. The platform has been installed in 19 homes (bvFTD: n = 10; PPA: n = 5; CBS/PSP: n = 4). Two homes discontinued due to death or relocation to assisted living facility. Mean data collection is 360 days (max = 527). Of 103 reported technological issues, 92% were resolved without additional home visits, either by phone or email. Participants completed 65% of weekly health questionnaires.ConclusionsAlthough there were some recruitment and retention challenges, these findings generally provide preliminary support for the feasibility and sustainability of conducting comprehensive in‐home passive data research in FTD.

AbstractBackgroundThere has been a rise in remote cognitive testing for neurodegenerative diseases. The ALLFTD Mobile App is designed to capture clinical features of frontotemporal dementia (FTD) through repeated remote assessment on smartphones. This is a departure from traditional neuropsychological practice in which a single examiner‐led assessment occurs in a controlled setting. When participants complete tasks on their own, those with greater disease severity may be more variable in their performance for a variety of reasons (e.g. greater distractibility, less engagement). Here we study whether intraindividual cognitive variability (IIV) is associated with older age and increasing disease severity.MethodParticipants were 279 (mean age = 54.9) healthy controls and participants with sporadic FTD or from familial FTD kindreds with a range of disease severities based on FTLD Clinical Dementia Rating scale (CDR®+NACC‐FTLD Global) scores: 0 (n = 132), 0.5 (n = 54), and ≥1 (n = 47). Participants completed three cognitive tasks at least two times across twelve days. Measures included an adaptive memory task and gamified versions of Flanker and Go/no‐go tasks. IIV was operationalized as the standard deviation in performance on each task. Regression analyses investigated the relationship of IIV with CDR®+NACC‐FTLD group, and with age in those without symptoms. Education and gender were included as covariates in all analyses.ResultGreater disease severity (CDR®+NACC‐FTLD) was associated with greater variability on Flanker (p<.001) and Go/No‐go (p = .02) tasks; a positive but non‐significant association was seen with memory testing (p = .16). Post‐hoc comparisons found that those with CDR®+NACC‐FTLD of 0.5 had significantly more IIV on the Flanker task (𝛃 = .39, p = .004) than those with CDR®+NACC‐FTLD’s of 0. Moreover, those with a CDR®+NACC‐FTLD ≥1 had significantly greater IIV on the Flanker (𝛃 = .85, p<.001) and Go/No‐go tasks (𝛃 = .51, p = .007) than those with a CDR®+NACC‐FTLD of 0. In those without symptoms (CDR®+NACC‐FTLD = 0), age was associated with increased IIV on the Flanker (𝛃 = .27, p<.001) and Go/no‐go (𝛃 = .23, p<.001) tasks.ConclusionIncreased IIV, particularly on processing speed/executive functioning tasks, was associated with greater age and greater functional impairment, even in the mildest stages. Future investigations exploring predictors of IIV and the prognostic value of IIV are warranted.