Browsing by Author "Kremers, Walter K."

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    Mayo Normative Studies: Amyloid and Neurodegeneration Negative Normative Data for the Auditory Verbal Learning Test and Sex-Specific Sensitivity to Mild Cognitive Impairment/Dementia
    (IOS Press, 2024) Stricker, Nikki H.; Christianson, Teresa J.; Pudumjee, Shehroo B.; Polsinelli, Angelina J.; Lundt, Emily S.; Frank, Ryan D.; Kremers, Walter K.; Machulda, Mary M.; Fields, Julie A.; Jack, Clifford R., Jr.; Knopman, David S.; Graff-Radford, Jonathan; Vemuri, Prashanthi; Mielke, Michelle M.; Petersen, Ronald C.; Neurology, School of Medicine
    Background: Conventional normative samples include individuals with undetected Alzheimer's disease neuropathology, lowering test sensitivity for cognitive impairment. Objective: We developed Mayo Normative Studies (MNS) norms limited to individuals without elevated amyloid or neurodegeneration (A-N-) for Rey's Auditory Verbal Learning Test (AVLT). We compared these MNS A-N- norms in female, male, and total samples to conventional MNS norms with varying levels of demographic adjustments. Methods: The A-N- sample included 1,059 Mayo Clinic Study of Aging cognitively unimpaired (CU) participants living in Olmsted County, MN, who are predominantly non-Hispanic White. Using a regression-based approach correcting for age, sex, and education, we derived fully-adjusted T-score formulas for AVLT variables. We validated these A-N- norms in two independent samples of CU (n = 261) and mild cognitive impairment (MCI)/dementia participants (n = 392) > 55 years of age. Results: Variability associated with age decreased by almost half in the A-N- norm sample relative to the conventional norm sample. Fully-adjusted MNS A-N- norms showed approximately 7- 9% higher sensitivity to MCI/dementia compared to fully-adjusted MNS conventional norms for trials 1- 5 total and sum of trials. Among women, sensitivity to MCI/dementia increased with each normative data refinement. In contrast, age-adjusted conventional MNS norms showed greatest sensitivity to MCI/dementia in men. Conclusions: A-N- norms show some benefits over conventional normative approaches to MCI/dementia sensitivity, especially for women. We recommend using these MNS A-N- norms alongside MNS conventional norms. Future work is needed to determine if normative samples that are not well characterized clinically show greater benefit from biomarker-refined approaches.
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    Plasma‐derived biomarkers of Alzheimer's disease and neuropsychiatric symptoms: A community‐based study
    (Wiley, 2023-07-30) Krell-Roesch, Janina; Zaniletti, Isabella; Syrjanen, Jeremy A.; Kremers, Walter K.; Algeciras-Schimnich, Alicia; Dage, Jeffrey L.; van Harten, Argonde C.; Fields, Julie A.; Knopman, David S.; Jack, Clifford R., Jr.; Petersen, Ronald C.; Vassilaki, Maria; Geda, Yonas E.; Neurology, School of Medicine
    Introduction: We examined associations between plasma-derived biomarkers of Alzheimer's disease (AD) and neuropsychiatric symptoms (NPS) in community-dwelling older adults. Methods: Cross-sectional study involving 1005 persons ≥50 years of age (mean 74 years, 564 male, 118 cognitively impaired), who completed plasma-derived biomarker (amyloid beta 42 [Aβ42]/Aβ40, phosphorylated tau 181 [p-tau181], p-tau217, total tau [t-tau], neurofilament light [NfL]), and NPS assessment. Results: P-tau181 (odds ratio [OR] 2.06, 95% confidence interval [CI] 1.41-3.00, p < 0.001), p-tau217 (OR 1.70, 95% CI 1.10-2.61, p = 0.016), and t-tau (OR 1.44, 95% CI 1.08-1.92, p = 0.012) were associated with appetite change. We also found that p-tau181 and p-tau217 were associated with increased symptoms of agitation (OR 1.93, 95% CI 1.20-3.11, p = 0.007 and OR 2.04, 95% CI 1.21-3.42, p = 0.007, respectively), and disinhibition (OR 2.39, 95% CI 1.45-3.93, p = 0.001 and OR 2.30, 95% CI 1.33-3.98, p = 0.003, respectively). Aβ42/Aβ40 and NfL were not associated with NPS. Conclusion: Higher plasma-derived p-tau181 and p-tau217 levels are associated with increased symptoms of appetite change, agitation, and disinhibition. These findings may support the validity of plasma tau biomarkers for predicting behavioral symptoms that often accompany cognitive impairment. Highlights: We studied 1005 community-dwelling persons aged ≥ 50 years. Higher plasma tau levels are associated with increased neuropsychiatric symptoms Aβ42/Aβ40 and NfL are not associated with neuropsychiatric symptoms. Clinicians should treat neuropsychiatric symptoms in persons with high plasma-derived tau.