| 1. |
- Gifford, Katherine A, et al.
(författare)
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The 12-Word Philadelphia Verbal Learning Test Performances in Older Adults: Brain MRI and Cerebrospinal Fluid Correlates and Regression-Based Normative Data.
- 2018
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Ingår i: Dementia and geriatric cognitive disorders extra. - : S. Karger AG. - 1664-5464. ; 8:3, s. 476-491
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Tidskriftsartikel (refereegranskat)abstract
- This study evaluated neuroimaging and biological correlates, psychometric properties, and regression-based normative data of the 12-word Philadelphia Verbal Learning Test (PVLT), a list-learning test.Vanderbilt Memory and Aging Project participants free of clinical dementia and stroke (n = 230, aged 73 ± 7 years) completed a neuropsychological protocol and brain MRI. A subset (n = 111) underwent lumbar puncture for analysis of Alzheimer's disease (AD) and axonal integrity cerebrospinal fluid (CSF) biomarkers. Regression models related PVLT indices to MRI and CSF biomarkers adjusting for age, sex, race/ethnicity, education, APOE-ε4 carrier status, cognitive status, and intracranial volume (MRI models). Secondary analyses were restricted to participants with normal cognition (NC; n = 127), from which regression-based normative data were generated.Lower PVLT performances were associated with smaller medial temporal lobe volumes (p < 0.05) and higher CSF tau concentrations (p < 0.04). Among NC, PVLT indices were associated with white matter hyperintensities on MRI and an axonal injury biomarker (CSF neurofilament light; p < 0.03).The PVLT appears sensitive to markers of neurodegeneration, including temporal regions affected by AD. Conversely, in cognitively normal older adults, PVLT performance seems to relate to white matter disease and axonal injury, perhaps reflecting non-AD pathways to cognitive change. Enhanced normative data enrich the clinical utility of this tool.
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| 2. |
- Gifford, Katherine A, et al.
(författare)
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Validity and Normative Data for the Biber Figure Learning Test: A Visual Supraspan Memory Measure.
- 2020
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Ingår i: Assessment. - : SAGE Publications. - 1552-3489 .- 1073-1911. ; 27:6, s. 1320-1334
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Tidskriftsartikel (refereegranskat)abstract
- The Biber Figure Learning Test (BFLT), a visuospatial serial figure learning test, was evaluated for biological correlates and psychometric properties, and normative data were generated. Nondemented individuals ( n = 332, 73 ± 7, 41% female) from the Vanderbilt Memory & Aging Project completed a comprehensive neuropsychological protocol. Adjusted regression models related BFLT indices to structural brain magnetic resonance imaging and cerebrospinal fluid (CSF) markers of brain health. Regression-based normative data were generated. Lower BFLT performances (Total Learning, Delayed Recall, Recognition) related to smaller medial temporal lobe volumes and higher CSF tau concentrations but not CSF amyloid. BFLT indices were most strongly correlated with other measures of verbal and nonverbal memory and visuospatial skills. The BFLT provides a comprehensive assessment of all aspects of visuospatial learning and memory and is sensitive to biomarkers of unhealthy brain aging. Enhanced normative data enriches the clinical utility of this visual serial figure learning test for use with older adults.
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| 3. |
- Kresge, Hailey A, et al.
(författare)
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Lower Left Ventricular Ejection Fraction Relates to Cerebrospinal Fluid Biomarker Evidence of Neurodegeneration in Older Adults.
- 2020
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Ingår i: Journal of Alzheimer's disease : JAD. - 1875-8908. ; 74:3, s. 965-974
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Tidskriftsartikel (refereegranskat)abstract
- Subclinical cardiac dysfunction is associated with decreased cerebral blood flow, placing the aging brain at risk for Alzheimer's disease (AD) pathology and neurodegeneration.This study investigates the association between subclinical cardiac dysfunction, measured by left ventricular ejection fraction (LVEF), and cerebrospinal fluid (CSF) biomarkers of AD and neurodegeneration.Vanderbilt Memory & Aging Project participants free of dementia, stroke, and heart failure (n=152, 72±6 years, 68% male) underwent echocardiogram to quantify LVEF and lumbar puncture to measure CSF levels of amyloid-β42 (Aβ42), phosphorylated tau (p-tau), and total tau (t-tau). Linear regressions related LVEF to CSF biomarkers, adjusting for age, sex, race/ethnicity, education, Framingham Stroke Risk Profile, cognitive diagnosis, and apolipoprotein E ɛ4 status. Secondary models tested an LVEF x cognitive diagnosis interaction and then stratified by diagnosis (normal cognitive (NC), mild cognitive impairment (MCI)).Higher LVEF related to decreased CSF Aβ42 levels (β=-6.50, p=0.04) reflecting greater cerebral amyloid accumulation, but this counterintuitive result was attenuated after excluding participants with cardiovascular disease and atrial fibrillation (p=0.07). We observed an interaction between LVEF and cognitive diagnosis on CSF t-tau (p=0.004) and p-tau levels (p=0.002), whereas lower LVEF was associated with increased CSF t-tau (β=-9.74, p=0.01) and p-tau in the NC (β=-1.41, p=0.003) but not MCI participants (p-values>0.13).Among cognitively normal older adults, subclinically lower LVEF relates to greater molecular evidence of tau phosphorylation and neurodegeneration. Modest age-related changes in cardiovascular function may have implications for pathophysiological changes in the brain later in life.
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| 4. |
- Moore, Elizabeth E, et al.
(författare)
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Axonal Injury Partially Mediates Associations Between Increased Left Ventricular Mass Index and White Matter Damage.
- 2021
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Ingår i: Stroke. - 1524-4628. ; 53:3, s. 808-816
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Tidskriftsartikel (refereegranskat)abstract
- Left ventricular (LV) mass index is a marker of subclinical LV remodeling that relates to white matter damage in aging, but molecular pathways underlying this association are unknown. This study assessed if LV mass index related to cerebrospinal fluid (CSF) biomarkers of microglial activation (sTREM2 [soluble triggering receptor expressed on myeloid cells 2]), axonal injury (NFL [neurofilament light]), neurodegeneration (total-tau), and amyloid-β, and whether these biomarkers partially accounted for associations between increased LV mass index and white matter damage. We hypothesized higher LV mass index would relate to greater CSF biomarker levels, and these pathologies would partially mediate associations with cerebral white matter microstructure.Vanderbilt Memory and Aging Project participants who underwent cardiac magnetic resonance, lumbar puncture, and diffusion tensor imaging (n=142, 72±6 years, 37% mild cognitive impairment [MCI], 32% APOE-ε4 positive, LV mass index 51.4±8.1 g/m2, NFL 1070±588 pg/mL) were included. Linear regressions and voxel-wise analyses related LV mass index to each biomarker and diffusion tensor imaging metrics, respectively. Follow-up models assessed interactions with MCI and APOE-ε4. In models where LV mass index significantly related to a biomarker and white matter microstructure, we assessed if the biomarker mediated white matter associations.Among all participants, LV mass index was unrelated to CSF biomarkers (P>0.33). LV mass index interacted with MCI (P=0.01), such that higher LV mass index related to increased NFL among MCI participants. Associations were also present among APOE-ε4 carriers (P=0.02). NFL partially mediated up to 13% of the effect of increased LV mass index on white matter damage.Subclinical cardiovascular remodeling, measured as an increase in LV mass index, is associated with neuroaxonal degeneration among individuals with MCI and APOE-ɛ4. Neuroaxonal degeneration partially reflects associations between higher LV mass index and white matter damage. Findings highlight neuroaxonal degeneration, rather than amyloidosis or microglia, may be more relevant in pathways between structural cardiovascular remodeling and white matter damage.
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| 5. |
- Moore, Elizabeth E, et al.
(författare)
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Neurofilament relates to white matter microstructure in older adults.
- 2018
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Ingår i: Neurobiology of aging. - : Elsevier BV. - 1558-1497 .- 0197-4580. ; 70, s. 233-241
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Tidskriftsartikel (refereegranskat)abstract
- Cerebrospinal fluid (CSF) neurofilament light (NFL) is a protein biomarker of axonal injury. To study whether NFL is associated with diffusion tensor imaging (DTI) measurements of white matter (WM) microstructure, Vanderbilt Memory & Aging Project participants with normal cognition (n= 77), early mild cognitive impairment (n= 15), and MCI (n= 55) underwent lumbar puncture to obtain CSF and 3T brain MRI. Voxel-wise analyses cross-sectionally related NFL to DTI metrics, adjusting for demographic and vascular risk factors. Increased NFL correlated with multiple DTI metrics (p-values < 0.05). An NFL× diagnosis interaction (excluding early mild cognitive impairment) on WM microstructure (p-values < 0.05) was detected, with associations strongest among MCI. Multiple NFL× CSF biomarker interactions were detected. Associations between NFL and worse WM metrics were strongest among amyloid-β42-negative, tau-positive, and suspected nonamyloid pathology participants. Findings suggest increased NFL, a biomarker of axonal injury, is correlated with compromised WM microstructure. Results highlight the role of elevated NFL in predicting WM damage in cognitively impaired older adults who are amyloid-negative, tau-positive, or meet suspected nonamyloid pathology criteria.
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| 6. |
- Winfree, Rebecca L, et al.
(författare)
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Biological correlates of elevated soluble TREM2 in cerebrospinal fluid.
- 2022
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Ingår i: Neurobiology of aging. - : Elsevier BV. - 1558-1497 .- 0197-4580. ; 118, s. 88-98
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Tidskriftsartikel (refereegranskat)abstract
- Cerebrospinal fluid (CSF) soluble triggering receptor expressed on myeloid cells-2 (sTREM2) is an emerging biomarker of neuroinflammation in Alzheimer's disease (AD). Yet, sTREM2 expression has not been systematically evaluated in relation to concomitant drivers of neuroinflammation. While associations between sTREM2 and tau in CSF are established, we sought to determine additional biological correlates of CSF sTREM2 during the prodromal stages of AD by evaluating CSF Aβ species (Aβx-40), a fluid biomarker of blood-brain barrier integrity (CSF/plasma albumin ratio), and CSF biomarkers of neurodegeneration measured in 155 participants from the Vanderbilt Memory and Aging Project. A novel association between high CSF levels of both sTREM2 and Aβx-40 was observed and replicated in an independent dataset. Aβx-40 levels, as well as the CSF/plasma albumin ratio, explained additional and unique variance in sTREM2 levels above and beyond that of CSF biomarkers of neurodegeneration. The component of sTREM2 levels correlated with Aβx-40 levels best predicted future cognitive performance. We highlight potential contributions of Aβ homeostasis and blood-brain barrier integrity to elevated CSF sTREM2, underscoring novel biomarker associations relevant to disease progression and clinical outcome measures.
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| 7. |
- Winfree, Rebecca L., et al.
(författare)
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Variants in the MS4A cluster interact with soluble TREM2 expression on biomarkers of neuropathology
- 2024
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Ingår i: MOLECULAR NEURODEGENERATION. - 1750-1326. ; 19:1
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Tidskriftsartikel (refereegranskat)abstract
- Recent evidence suggests that Alzheimer's disease (AD) genetic risk variants (rs1582763 and rs6591561) of the MS4A locus are genome-wide significant regulators of soluble TREM2 levels such that the minor allele of the protective variant (rs1582763) is associated with higher sTREM2 and lower AD risk while the minor allele of (rs6591561) relates to lower sTREM2 and higher AD risk. Our group previously found that higher sTREM2 relates to higher A beta(40), worse blood-brain barrier (BBB) integrity (measured with the CSF/plasma albumin ratio), and higher CSF tau, suggesting strong associations with amyloid abundance and both BBB and neurodegeneration complicate interpretation. We expand on this work by leveraging these common variants as genetic tools to tune the interpretation of high CSF sTREM2, and by exploring the potential modifying role of these variants on the well-established associations between CSF sTREM2 as well as TREM2 transcript levels in the brain with AD neuropathology. Biomarker analyses leveraged data from the Vanderbilt Memory & Aging Project (n = 127, age = 72 +/- 6.43) and were replicated in the Alzheimer's Disease Neuroimaging Initiative (n = 399, age = 73 +/- 7.39). Autopsy analyses were performed leveraging data from the Religious Orders Study and Rush Memory and Aging Project (n = 577, age = 89 +/- 6.46). We found that the protective variant rs1582763 attenuated the association between CSF sTREM2 and A beta(40) (beta = -0.44, p-value = 0.017) and replicated this interaction in ADNI (beta = -0.27, p = 0.017). We did not observe this same interaction effect between TREM2 mRNA levels and A beta peptides in brain (A beta total beta = -0.14, p = 0.629; A beta(1-38), beta = 0.11, p = 0.200). In contrast to the effects on A beta, the minor allele of this same variant seemed to enhance the association with blood-brain barrier dysfunction (beta = 7.0e-4, p = 0.009), suggesting that elevated sTREM2 may carry a much different interpretation in carriers vs. non-carriers of this allele. When evaluating the risk variant (rs6591561) across datasets, we did not observe a statistically significant interaction against any outcome in VMAP and observed opposing directions of associations in ADNI and ROS/MAP on A beta levels. Together, our results suggest that the protective effect of rs1582763 may act by decoupling the associations between sTREM2 and amyloid abundance, providing important mechanistic insight into sTREM2 changes and highlighting the need to incorporate genetic context into the analysis of sTREM2 levels, particularly if leveraged as a clinical biomarker of disease in the future.
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