Citations

Abstract Background White matter (WM) plays a dual role in interacting with tau pathology. There is an intricate dynamic relationship with WM acting as highways for tau spreading, while the increasing tau burden ultimately compromises WM health. We aimed at studying the associations between tau accumulation and WM integrity using longitudinal data with focus on sex differences. Method We included 374 participants who had longitudinal multishell diffusion MRI and flortaucipir PET (baseline mean age = 70.9 years, 52% male, 17% MCI/AD dementia) scans from the Mayo ADRC and Mayo Clinic Study of Aging. Rate of tau accumulation was calculated from the entorhinal cortex (ERC) and inferior temporal cortex (IT) SUVRs, with IT‐WM serving as the WM highway between the two regions. IT‐WM was defined by JHU “Eve” WM atlas, and its integrity was assessed using neurite density index (NDI), which reflects the packing density of neurites. Structural equation modeling (SEM) evaluated relationships between tau and WM metrics. Result At baseline, males and females showed no significant differences in tau SUVR or IT‐WM NDI ( p >0.05), though males had higher vascular risk and averaged two years older than females (Table 1). Figure 1a showed that baseline ERC‐tau influenced baseline IT‐tau, as well as both rate of ERC‐tau and baseline IT‐tau influenced rate of IT‐tau. After incorporating IT‐WM NDI as a mediator (Figure 1b), we discovered 1) baseline ERC‐tau influencing rate of IT‐tau accumulation through baseline IT‐WM NDI, suggesting the role of WM health in the rate of tau accumulation; 2) Rate of IT‐tau accumulation negatively affected follow‐up IT‐WM NDI suggesting the deterioration of WM health as tau accumulation progresses. These relationships were stronger in males compared to females. We also observed greater impact of vascular risk on WM health in males and greater rates of IT‐tau accumulation in females. Conclusion Our work sheds light on the mechanistic role of intact WM in tau accumulation (through dense microtubules and synaptic connections) and the deterioration of WM that is associated with higher rates of tau accumulation. We found interesting sex differences that warrant further investigation.

Abstract Background Corticobasal syndrome (CBS) is a neurodegenerative disease usually associated with accumulation of tau in the cortex and basal ganglia, leading to cognitive, movement, and behavioral symptoms that progressively impair function. Few clinical trials have ever been conducted in CBS, and perceptions and preferences about clinical trials in this population are largely unknown. Method An online survey was conducted (February 2015 ‐ November 2020) among research participants recruited through a multisite observational study (ARTFL). Responses from patients with CBS were tabulated and reported below. Result N=66 respondents had CBS as a primary or secondary phenotype (determined by study clinician), with 62% of surveys patient‐reported, and 38% completed by a caregiver/family member. Within CBS, 91% requested to be contacted about clinical trials. 2/6 decliners commented that disease severity precluded participation. 97% were willing to come in annually, 88% quarterly (3 months), 66% monthly, 43% weekly, and 17% would come in more than weekly; two patients could not travel due to disease severity. Comments included “we would live here for trials” and “whatever is needed.” Full day evaluations were acceptable to 91%, whereas 9% preferred a half‐day or less, although 65% would complete multi‐day evaluations spread over a week. Numerous remote and in person modes of assessment (e.g., surveys, examinations, cognitive testing, blood/saliva sampling, MRI, PET), were broadly acceptable by respondents (80‐93%), whereas remote activity monitoring (70%), lumbar puncture (68%), and remote video conferencing memory testing (67%) were less preferred, though still broadly acceptable. For distance willing to travel, 95% would travel 30 minutes, 91% one hour, 65% three hours, 54% five hours, and 37% would travel more than five hours or take a flight if needed. Travel reimbursement was very/extremely important for 40%, and unimportant for 26% (34% neutral). Feedback about clinical progression (81%), study results (74%), and an open‐label extension (68%) were factors identified as the highest importance to patients. Conclusion Patients with CBS are eager to participate in clinical trials, even trials that are complex, far away, and have visits over multiple days. Travel reimbursement, providing feedback to patients, and access to experimental treatments were key considerations.

Abstract Background HEAD is a longitudinal, multi‐site, non‐randomized study aiming to harmonize different tau PET tracers onto a common scale for enrichment and monitoring of anti‐tau clinical trials. To achieve this, the Uniτ scale is being developed using data from participants scanned head‐to‐head with Flortaucipir and MK6240, with a subset also scanned with PI2620 and RO948. However, access to the Uniτ scale has been limited to the study community and collaborators. To address this limitation, we have developed the Uniτ Ecosystem – a set of tools for tau PET harmonization designed to support research and clinical trials ( www.unitau.app ). Method The Uniτ Ecosystem was developed for multiple operating systems (Web/macOS/Windows/Ubuntu) (Figure 1) and currently include four tools. The Uniτ harmonization is an online ROI harmonization module that allows the user to harmonize SUVRs from spreadsheets. The Uniτ packages (R, Python and MATLAB) facilitates the transformation of SUVR values to the Uniτ scale using the most used programming languages in research settings. The Uniτ calculator app allows rapid and convenient harmonization. The Uniτ desktop app is a 3D harmonization module for voxel‐wise harmonization. The Uniτ parameters were calculated using a training set of 200 participants with head‐to‐head MK6240 and Flortaucipir, and 90 individuals with additional PI2620 and RO948. Researchers can use their own datasets and convert tau PET data to the Uniτ scale. Result The online ROI harmonization module allows users to harmonize tau PET SUVRs uploaded from spreadsheets and offers interactive visualizations such as scatter plots and histograms for tau positivity thresholds (Figure 2). The calculator app enables users to harmonize single SUVR values effortlessly. The desktop application for 3D tau PET harmonization leverages the functionalities of the previous modules to harmonize entire 3D images, eliminating the need for predefined ROIs. Additionally, this module provides visualization tools for the parametric Uniτ images in 2D and 3D (Figure 3). Uniτ tools never store any data on any external servers. Conclusion The Uniτ Ecosystem represents a significant advance in tau PET harmonization, providing a user‐friendly platform to harmonize and visualize tau PET data for research and clinical trials.

Abstract Objective Intraoperative parathyroid hormone (ioPTH) monitoring is crucial during parathyroid surgery to ensure chemical cure. However, delays in processing can prolong operative times. This study evaluates the effectiveness of a checklist to expedite ioPTH assay processes. Methods A multidisciplinary checklist was developed to standardize ioPTH collection and workflow. Thirty patients treated with use of the checklist were prospectively studied, while 30 patients treated without use of the checklist were retrospectively reviewed. Time intervals for post–15‐minute ioPTH assay results were compared. Results Thirty age‐ and sex‐matched patients were included in each group (n = 60) involving 5 surgeons. The intervention and control group had a mean baseline PTH of 140.9 and 130.3 pg/mL and a post–15‐minute ioPTH of 69.6 and 52.0 pg/mL, respectively. The mean time from sample collection to the post–15‐minute ioPTH assay result was significantly reduced in the intervention as compared to the control group (22.2 vs 33.3 minutes; P < .01). The proportional operative time spent awaiting ioPTH assay results was also reduced (24.4 vs 34.1%; P < .01). In subgroup analysis, a significant difference in the total operative time was found in adenomatous disease (68.0 vs 92.2 minutes, P < .05) but not four‐gland hyperplasia (119.3 vs 142.3 minutes). Discussion The implementation of a simple intraoperative checklist effectively reduces the overall ioPTH assay processing time, creating a more efficient surgical workflow. It is low‐cost and requires minimal additional resources. Implications for Practice This quality improvement intervention holds promise for broader adoption in parathyroid surgery to reduce delays and optimize patient care.

Abstract Background Tau PET tracers present distinct binding characteristics that might influence their trajectories and relationship with other biomarkers along the AD continuum. In a head‐to‐head study, we investigated the relationship between the emergence of PET tracers MK6240 and Flortaucipir, and plasma p ‐tau217 abnormalities as a function of Aβ PET deposition. We further assessed the concordance between tau PET and plasma p ‐tau217 positivity and its relationship with cognitive scores. Method We evaluated 352 individuals from the HEAD study (205 cognitively unimpaired and 147 cognitively impaired) with Aβ PET, MK6240 and Flortaucipir tau PET, and plasma p ‐tau217 (ALZpath) and GFAP (Quanterix) measures. Tau PET Braak regions, plasma p ‐tau217 trajectories were modeled as functions of Aβ burden (Centiloid scale) using the Lowess method. Biomarkers were z‐scored anchored on young individuals ( n = 19, < 28 years old) as anchors. Tau PET (Braak 1 region) and plasma p ‐tau217 were considered positive/abnormal when surpassing 2.5 z‐score. Result Among the tested markers, MK6240 was the earliest to show abnormality as a function of Centiloid, occurring at 22 Centiloids, followed by plasma p ‐tau217 at 38 Centiloid and Flortaucipir at Centiloid 56 (Figure 1). Tau PET and plasma p ‐tau217 positivity showed an overall high concordance (∼80% for both tracers; Figure 2). In MK6240 discordant cases, most individuals were MK6240+/p‐tau217‐ (13.8%), while 6.6% were MK6240‐/p‐tau217+ (Figure 2A). For Flortaucipir, 15% of discordant cases were Flortaucipir‐/p‐tau217+, while 4.8% were Flortaucipir+/p‐tau217‐ (Figure 2B). The discordant groups present higher Centiloid than the ptau217‐/Tau‐ group and overall decreased scores in cognitive tests, except for p ‐tau217+/MK6240‐ group (Figure 3). Conclusion MK6240 becomes abnormal at lower levels of Aβ burden compared to plasma p ‐tau217 and Flortaucipir. The relatively high prevalence of discordant tau PET positive or plasma p ‐tau217 positive and suggests that some individuals may show tau PET positivity first, while others may exhibit plasma p ‐tau217 positivity first. The distinct cognitive profiles of this groups suggest potential clinical relevance, warranting further investigation.

Abstract Background Individuals with preclinical AD are difficult to detect using traditional clinical tools. Yet, many individuals classified as cognitively unimpaired (CU) can exhibit a heterogeneous pattern of subtle clinical abnormalities, potentially linked to early Alzheimer's disease (AD). Primary care providers often have access only to clinical tests to study at‐risk community‐dwelling older adults who visit them without cognitive complaints. Since early intervention is crucial in AD, identifying clinical tools to detect preclinical AD is important in areas with limited access to blood or imaging biomarkers. In this study, we evaluate the link between Montreal Cognitive Assessment (MoCA) total scores and AD pathology in CU individuals. Methods We studied 204 cognitively unimpaired (CU) older adults who underwent both 18 F‐FTP and 18 F‐MK6240 scans. These individuals were stratified based on their amyloid PET status, determined by visual reading, into CU A+ ( n = 35) and CU A‐ ( n = 137), as part of the ongoing HEAD study. CU adults had Clinical Dementia Rating (CDR) of 0 and were clinically identified as non‐MCI and non‐demented. Voxel‐wise linear regression models tested the association between MoCA total scores and tau pathology. Results CU A+T+ had significantly lower total MoCA scores than A‐T‐ individuals (Figure 1). Lesser MoCA total score was significantly associated with greater mediobasal temporal tau deposition, using both 18 F‐MK6240 and 18 F‐FTP [Figure 2]. When we separated the population by Aβ status, we found that these results were driven by the CU A+ group (Figure 3A) and were not present in CU A‐ individuals (Figure 3B). Discussion These findings indicate that the MoCA, a simple routine in‐office clinical test, can detect subtle cognitive dysfunction associated with preclinical AD. This suggests that simple cognitive testing can play a role in the early detection of AD and therefore an option for prescreening older adults in non‐specialized clinical settings, the initial interface for most older adults without cognitive complaints. Conclusion MoCA total, the common dementia screening test also plays a valuable role in detecting preclinical AD.

Abstract Background Prion diseases are universally fatal causes of rapid progressive dementia owing to the formation and spread of prions throughout the brain. Palliative care focuses on improving quality of life for patients with serious or advanced medical conditions. Timely access to palliative care is central to the care of patients with prion disease and other progressive neurodegenerative diseases. We sought to evaluate palliative care utilization and mode of delivery in patients with prion disease. Method Clinical data were extracted from the electronic medical records of patients with definite or probable prion disease diagnosed and managed across the Mayo Clinic Enterprise from January 2012 to August 2023. We systematically evaluated the frequency of symptoms and signs likely to benefit from palliative care and considered the relationship between these features and palliative care resource utilization, method of delivery, and outcomes. Result 172 patients with symptomatic prion disease were identified. 165 (94.8%) patients experienced ≥1 symptom/sign likely to benefit from palliative care, yet only 113 (65.7%) patients accessed palliative care resources during the illness course (hospice care: 39.7%; palliative care consultation: 14.9% inpatient, 6.9% outpatient; both: 3.4%). Lack of referral by the diagnosing clinician was the most common reason (55.9%) patients did not receive palliative care services. Early and predominant language dysfunction, behavioral changes, constipation, and emergency department visits or hospital admissions were independently associated with greater odds of referral for palliative care services. Goals of care (i.e., living environment, nutritional and hospitalization plans) and advanced care plans (i.e., healthcare surrogates, living will, code status, hospice) were more likely to be documented in patients receiving palliative care consultations (88.6% and 93.2%, respectively) versus hospice care alone (7.8% and 14.5%, respectively; p <0.001). Conclusion More than a third of patients with prion disease did not receive palliative care resources despite a high prevalence of symptoms/signs likely to benefit from palliative care. These findings highlight an opportunity to enhance the care of patients with prion disease by promoting early access to palliative care resources that may support symptom management, enhance caregiver support, and reinforce patient autonomy by clarifying goals of care and advance care planning.

ABSTRACT Background Mood episodes in bipolar disorder (BD) follow a seasonal pattern in approximately 25% of patients. We aimed to examine the associations of specific seasonality patterns in BD with various clinical phenotypes and treatment‐related outcomes. Methods Patients from the Mayo Clinic Bipolar Disorder Biobank with available seasonality data were included in the study. Among those reporting any seasonality, participants were further categorized into four seasonality groups: fall/winter depression, spring/summer (hypo)mania, biphasic (fall/winter depression with spring/summer (hypo)mania), and equinoctial seasonality (any mood episode occurring in spring or fall). Regression models were used, treating seasonality patterns as the predictor of clinical phenotypes (BD subtype, early onset, history of psychosis, suicide attempt, rapid cycling), lifetime medication exposure (number of unique antidepressants, antipsychotics, and any psychotropics) and treatment response to mood stabilizers (Alda A score). Results Among 1702 patients with BD (61.5% female, mean age = 41.43 ± 14.73 years), 44.6% reported seasonal mood episodes. Individuals with any seasonality were more likely to have BD‐I (OR = 1.29, p = 0.024), early onset (OR = 1.29, p = 0.026), exposure to higher lifetime number of antipsychotics (IRR = 1.20, p < 0.001) and any psychotropics (IRR = 1.13, p < 0.001). Fall/winter depression was associated with a higher lifetime number of antidepressants (IRR = 1.18, p = 0.021), any psychotropics (IRR = 1.14, p = 0.013), worse response to lithium ( β = −0.82, p = 0.029) and all mood stabilizers ( β = −0.69, p = 0.014). Spring/summer (hypo)mania showed negative associations with rapid cycling (OR = 0.36, p < 0.001) and lifetime number of antidepressants (IRR = 0.70, p = 0.013). Equinoctial seasonality was linked to a history of psychosis (OR = 1.76, p = 0.004). Conclusion Seasonality in BD is associated with distinct clinical features and treatment‐related outcomes. Specific seasonality patterns, particularly fall/winter depression, may reflect a more complex and difficult‐to‐treat illness course. These findings highlight the need for research to better characterize seasonality subtypes beyond a binary “seasonal” vs. “non‐seasonal” classification and to explore how these patterns influence the illness course and management of BD.

Abstract Background Prior studies of Alzheimer's disease (AD) biomarker disclosure have answered important questions about individuals’ experiences learning amyloid results. In comparison, the experiences of individuals performing AD biomarker disclosure have been under characterized. The present study examines the clinician experience disclosing amyloid positron emission tomography (PET) results within the Alzheimer's Disease Neuroimaging Initiative's ADNI‐4 study. Methods The ADNI‐4 longitudinal cohort study includes a pragmatic process for amyloid PET disclosure for participants across the cognitive spectrum. Disclosing clinicians complete a short questionnaire after each disclosure session, reporting on the visit length, the clinician's rating of participant and study partner understanding and emotional reactions, topics discussed, challenges, assessment of the visit overall, and any feedback about the process. Results Across the first 100 disclosures (48 cognitively normal, 35 Mild Cognitive Impairment (MCI), 17 dementia) in ADNI‐4, visits lasted an average of 29.4 minutes (SD 13.9, range 10‐90). Most cognitively impaired participants had a loved one present at the disclosure visit (dementia 94%, MCI 80%) but the majority of cognitively normal participants (73%) did not. Clinicians rated understanding of the result as adequate for all study partners and the vast majority (94%) of participants. Clinicians reported feeling “very confident” in their ability to assess readiness to receive result (70%), disclose (73%), and answer questions (77%). Clinicians rated all visits as “good” or better, with two‐thirds (65%) rated as “excellent.” Frequently discussed topics included meaning of result (99%), other risk factors (72%), and emotional impact of result (49%). Stigma and discrimination were rarely discussed, coming up in 12% and 3% of disclosure sessions, respectively. Challenges were infrequent (7%) and primarily included desire for additional information and challenges related to the participant's impairment. Clinicians provided the study team feedback about the disclosure process for 25% of disclosure visits. Comments included the desire for additional information or resources, positive feedback, and the importance of the study partner. Conclusions Clinicians disclosing amyloid PET results in ADNI‐4 report high confidence, adequate participant and study partner understanding, and few challenges. These data from clinicians, in combination with participant data, will inform future disclosure practices in both research and care.