Publications by authors named "Rumbaugh M"

Ethics Review began a decade ago with a mission to identify ethical concerns that hold back innovation and to promote solutions that would move the field forward. Over this time, blood biomarkers for brain pathology and medications that treat that pathology promise to transform research and care. A central problem is that the evidence needed to guide test interpretation and practice is accumulating and there are unanswered questions.

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  • Researchers developed an MRI-based signature to identify brain atrophy linked to sporadic early-onset Alzheimer's disease (EOAD) using two patient samples, one small (n=25) and another larger (n=211).
  • The study found consistent atrophy patterns in specific brain regions, like the caudal lateral temporal cortex and inferior parietal lobule, while the medial temporal lobe was relatively spared.
  • The EOAD-signature atrophy correlates with cognitive impairment severity, suggesting it's a reliable biomarker for Alzheimer’s-related neurodegeneration in clinical trials.
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  • The LEADS study focuses on understanding the genetic causes of early-onset Alzheimer's Disease (EOAD), specifically in individuals aged 40-64, by screening for known pathogenic variants.
  • *Whole exome sequencing of 299 participants found pathogenic variants in 1.35% of EOAD cases and 6.58% of early-onset non-Alzheimer's disease cases, but no gene showed a significant enrichment for rare functional variants.
  • *The findings suggest that LEADS may include new genetic variants related to early-onset cognitive impairment, making it an important resource for ongoing Alzheimer's research.*
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  • The study examines the Rey Auditory Verbal Learning Test (RAVLT) as a tool for assessing memory impairment in early-onset Alzheimer's disease (EOAD), focusing on the effects of amyloid presence and diagnostic syndrome.
  • RAVLT recordings from 303 participants were analyzed, revealing that amyloid-positive individuals showed significant differences in memory performance compared to amyloid-negative individuals, including effects on raw scores and timing measures.
  • The findings suggest that RAVLT is sensitive to variations in memory impairment linked to amyloid and syndrome types in EOAD, highlighting the need for further research to understand the predictive capabilities of these memory scores.
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Introduction: We used sex and apolipoprotein E ε4 (APOE ε4) carrier status as predictors of pathologic burden in early-onset Alzheimer's disease (EOAD).

Methods: We included baseline data from 77 cognitively normal (CN), 230 EOAD, and 70 EO non-Alzheimer's disease (EOnonAD) participants from the Longitudinal Early-Onset Alzheimer's Disease Study (LEADS). We stratified each diagnostic group by males and females, then further subdivided each sex by APOE ε4 carrier status and compared imaging biomarkers in each stratification.

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  • The Longitudinal Early Onset Alzheimer's Disease Study (LEADS) aims to identify fluid biomarker characteristics specific to early-onset Alzheimer's disease (EOAD).
  • The study measured various cerebrospinal fluid (CSF) biomarkers in 165 participants, finding significant differences in certain biomarker levels between EOAD, cognitively normal individuals, and those with early-onset non-AD dementia.
  • The results highlight the correlation between biomarkers and cognitive performance, particularly within the EOAD group, providing valuable insights for future clinical trials targeting sporadic EOAD.
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Introduction: We compared white matter hyperintensities (WMHs) in early-onset Alzheimer's disease (EOAD) with cognitively normal (CN) and early-onset amyloid-negative cognitively impaired (EOnonAD) groups in the Longitudinal Early-Onset Alzheimer's Disease Study.

Methods: We investigated the role of increased WMH in cognition and amyloid and tau burden. We compared WMH burden of 205 EOAD, 68 EOnonAD, and 89 CN participants in lobar regions using t-tests and analyses of covariance.

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Introduction: We examined neuropsychiatric symptoms (NPS) and psychotropic medication use in a large sample of individuals with early-onset Alzheimer's disease (EOAD; onset 40-64 years) at the midway point of data collection for the Longitudinal Early-onset Alzheimer's Disease Study (LEADS).

Methods: Baseline NPS (Neuropsychiatric Inventory - Questionnaire; Geriatric Depression Scale) and psychotropic medication use from 282 participants enrolled in LEADS were compared across diagnostic groups - amyloid-positive EOAD (n = 212) and amyloid negative early-onset non-Alzheimer's disease (EOnonAD; n = 70).

Results: Affective behaviors were the most common NPS in EOAD at similar frequencies to EOnonAD.

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Objective: The Longitudinal Early-Onset Alzheimer's Disease Study (LEADS) seeks to provide comprehensive understanding of early-onset Alzheimer's disease (EOAD; onset <65 years), with the current study profiling baseline clinical, cognitive, biomarker, and genetic characteristics of the cohort nearing the data-collection mid-point.

Methods: Data from 371 LEADS participants were compared based on diagnostic group classification (cognitively normal [n = 89], amyloid-positive EOAD [n = 212], and amyloid-negative early-onset non-Alzheimer's disease [EOnonAD; n = 70]).

Results: Cognitive performance was worse for EOAD than other groups, and EOAD participants were apolipoprotein E (APOE) ε4 homozygotes at higher rates.

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Objective: Investigation of learning slopes in early-onset dementias has been limited. The current study aimed to highlight the sensitivity of learning slopes to discriminate disease severity in cognitively normal participants and those diagnosed with early-onset dementia with and without β-amyloid positivity METHOD: Data from 310 participants in the Longitudinal Early-Onset Alzheimer's Disease Study (aged 41 to 65) were used to calculate learning slope metrics. Learning slopes among diagnostic groups were compared, and the relationships of slopes with standard memory measures were determined RESULTS: Worse learning slopes were associated with more severe disease states, even after controlling for demographics, total learning, and cognitive severity.

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The brain changes of Alzheimer's disease and other degenerative dementias begin long before cognitive dysfunction develops, and in people with subtle cognitive complaints, clinicians often struggle to predict who will develop dementia. The public increasingly sees benefits to accessing dementia risk evidence (DRE) such as biomarkers, predictive algorithms, and genetic information, particularly as this information moves from research to demonstrated usefulness in guiding diagnosis and clinical management. For example, the knowledge that one has high levels of amyloid in the brain may lead one to seek amyloid reducing medications, plan for disability, or engage in health promoting behaviors to fight cognitive decline.

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We report on the initial 17 (11 male:6 female) brain autopsies from across Europe and the United States in the Parkinson's Progression Markers Initiative (PPMI). Clinical diagnoses were Parkinson's disease (n = 15), multiple system atrophy (n = 1), and Dementia with Lewy bodies (n = 1); average age of death = 72 ± 8 yr. Cognitive assessment at last evaluation was 5 with normal cognition, 7 with mild cognitive impairment, and 5 with dementia.

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This guidance can help shape the conversations you have with patients who want to understand the results of their gene and biomarker testing for Alzheimer disease.

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In this article we address how the recent, and anticipated upcoming, FDA approvals of novel anti-amyloid medications to treat individuals with mild Alzheimer's disease (AD) dementia could impact disclosure of biomarker results among asymptomatic research participants. Currently, research is typically the context where an asymptomatic individual may have the option to learn their amyloid biomarker status. Asymptomatic research participants who learn their amyloid status may have questions regarding the meaning of this result and the implications for accessing a potential intervention.

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Introduction: This study describes practices for disclosing individual research results to participants in Alzheimer's disease research.

Methods: An online survey of clinical core leaders at National Institutes of Health-funded Alzheimer's Disease Research Centers in the United States (response rate: 30/31, 97%) examined return of results practices across nine different types of research results.

Results: Most centers had returned consensus research diagnoses (83%) and neuropsychological test results (73%), with fewer having shared amyloid positron emission tomography (43%), tau imaging (10%), or apolipoprotein E () genotype (7%) results.

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Patients with early-onset Alzheimer's disease (EOAD) are commonly excluded from large-scale observational and therapeutic studies due to their young age, atypical presentation, or absence of pathogenic mutations. The goals of the Longitudinal EOAD Study (LEADS) are to (1) define the clinical, imaging, and fluid biomarker characteristics of EOAD; (2) develop sensitive cognitive and biomarker measures for future clinical and research use; and (3) establish a trial-ready network. LEADS will follow 400 amyloid beta (Aβ)-positive EOAD, 200 Aβ-negative EOnonAD that meet National Institute on Aging-Alzheimer's Association (NIA-AA) criteria for mild cognitive impairment (MCI) or AD dementia, and 100 age-matched controls.

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Genetic testing for Parkinson's disease (PD) is growing as interventional clinical trials begin to enroll participants with PD who carry pathogenic variants in the LRRK2 or GBA genes. However, the impact of receiving genetic test results and the satisfaction with receiving genetic counseling among PD populations have not yet been studied. The purpose of this study was to evaluate (1) the psychological impact of genetic testing for PD and (2) satisfaction with genetic counseling.

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Facebook advertising is a powerful tool for increasing the outreach and recruitment of research participants. We describe our experience as genetic counselors within the context of an internet-based research study, recruiting subjects for a Parkinson disease (PD) biomarker study.

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Importance: The R47H variant in the triggering receptor expressed on myeloid cells 2 gene (TREM2), a modulator of the immune response of microglia, is a strong genetic risk factor for Alzheimer disease (AD) and possibly other neurodegenerative disorders.

Objective: To investigate a large family with late-onset AD (LOAD), in which R47H cosegregated with 75% of cases.

Design, Setting, And Participants: This study includes genetic and pathologic studies of families with LOAD from 1985 to 2014.

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Alzheimer disease is the most common cause of dementia. It occurs worldwide and affects all ethnic groups. The incidence of Alzheimer disease is increasing due, in part, to increased life expectancy and the aging baby boomer generation.

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Aim: Neuropathological examination of both individuals in a monozygotic (MZ) twin pair with Alzheimer's disease (AD) is rare, especially in the molecular genetic era. We had the opportunity to assess the concordance and discordance of clinical presentation and neuropathology in three MZ twin pairs with AD.

Methods: The MZ twins were identified and characterised by the University of Washington Alzheimer's Disease Research Center.

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Background: Genetic influences on the development of late-onset Alzheimer disease (LOAD) are heterogeneous and ill defined.

Objective: To determine the genetic risk factors for LOAD.

Design: We asked the following questions: (1) Does early-onset Alzheimer disease (EOAD) occur in families with predominantly LOAD? and (2) Does the apolipoprotein E (APOE) genotype explain the wide differences in onset age in LOAD families?

Setting: University of Washington Alzheimer Disease Research Center, Seattle.

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Objectives: To compare arterial bursting pressure after vessel closure using a vessel-sealing device (LigaSure Atlas Laparoscopic Sealer/Divider Instrument; Valleylab, Boulder, CO), a ligate-and-divide stapling device (LDS), and 2-0 polydioxanone suture. To evaluate the LigaSure Atlas as a method for ligation of the mesenteric vasculature during small intestinal resection in normal horses.

Study Design: Experimental study.

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