scholarly journals Tau-PET and in vivo Braak-staging as prognostic markers of future cognitive decline in cognitively normal to demented individuals

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Davina Biel ◽  
Matthias Brendel ◽  
Anna Rubinski ◽  
Katharina Buerger ◽  
Daniel Janowitz ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Cognitive Decline ◽  
Prognostic Markers ◽  
Patient Specific ◽  
Amyloid Pet ◽  
Braak Stage ◽  
Cognitively Normal ◽  
Braak Staging ◽  
Pet Tracer ◽  
Tau Pet

Abstract Background To systematically examine the clinical utility of tau-PET and Braak-staging as prognostic markers of future cognitive decline in older adults with and without cognitive impairment. Methods In this longitudinal study, we included 396 cognitively normal to dementia subjects with 18F-Florbetapir/18F-Florbetaben-amyloid-PET, 18F-Flortaucipir-tau-PET and ~ 2-year cognitive follow-up. Annual change rates in global cognition (i.e., MMSE, ADAS13) and episodic memory were calculated via linear-mixed models. We determined global amyloid-PET (Centiloid) plus global and Braak-stage-specific tau-PET SUVRs, which were stratified as positive(+)/negative(−) at pre-established cut-offs, classifying subjects as Braak0/BraakI+/BraakI–IV+/BraakI–VI+/Braakatypical+. In bootstrapped linear regression, we assessed the predictive accuracy of global tau-PET SUVRs vs. Centiloid on subsequent cognitive decline. To test for independent tau vs. amyloid effects, analyses were further controlled for the contrary PET-tracer. Using ANCOVAs, we tested whether more advanced Braak-stage predicted accelerated future cognitive decline. All models were controlled for age, sex, education, diagnosis, and baseline cognition. Lastly, we determined Braak-stage-specific conversion risk to mild cognitive impairment (MCI) or dementia. Results Baseline global tau-PET SUVRs explained more variance (partial R2) in future cognitive decline than Centiloid across all cognitive tests (Cohen’s d ~ 2, all tests p < 0.001) and diagnostic groups. Associations between tau-PET and cognitive decline remained consistent when controlling for Centiloid, while associations between amyloid-PET and cognitive decline were non-significant when controlling for tau-PET. More advanced Braak-stage was associated with gradually worsening future cognitive decline, independent of Centiloid or diagnostic group (p < 0.001), and elevated conversion risk to MCI/dementia. Conclusion Tau-PET and Braak-staging are highly predictive markers of future cognitive decline and may be promising single-modality estimates for prognostication of patient-specific progression risk in clinical settings.

scholarly journals Tau-PET and in vivo Braak-staging as a prognostic marker in Alzheimer’s disease

2021 ◽  
Author(s):  
Davina Biel ◽  
Matthias Brendel ◽  
Anna Rubinski ◽  
Katharina Buerger ◽  
Daniel Janowitz ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Decline ◽  
Prognostic Marker ◽  
Cognitive Change ◽  
Patient Specific ◽  
Amyloid Pet ◽  
Braak Stage ◽  
Braak Staging ◽  
Tau Pet

ABSTRACTINTRODUCTIONTau pathology in Alzheimer’s disease tracks clinical status more closely than beta-amyloid. Thus, tau-PET may be a promising prognostic marker for cognitive decline. Here, we systematically compared tau-PET and Braak-staging vs. amyloid-PET as predictors of cognitive decline.METHODSWe included 396 cognitively normal to dementia subjects with 18F-Flutemetamol/18F-Florbetapir-amyloid-PET, 18F-Flortaucipir-tau-PET and ~2-year cognitive assessments. Annual cognitive change rates were calculated via linear-mixed models. We determined global amyloid-PET, global tau-PET, and tau-PET-based Braak-stage (Braak0/BraakI+/BraakI-IV+/BraakI-VI+/Braakatypical+). In bootstrapped linear regression, we assessed whether tau-PET outperformed amyloid-PET in predicting cognitive decline. Using ANCOVAs, we tested whether later Braak-stage predicted accelerated cognitive decline and determined Braak-stage-specific conversion risk to MCI or dementia.RESULTSGlobal tau-PET was a better predictor of cognitive decline than global amyloid-PET (p<0.001). Advanced Braak-stage was associated with faster cognitive decline (p<0.001) and elevated clinical conversion risk.DISCUSSIONTau-PET and Braak-staging show promise for predicting patient-specific risk of clinical AD progression.

scholarly journals Patient-centered connectivity-based prediction of tau pathology spread in Alzheimer’s disease

2020 ◽  
Vol 6 (48) ◽  
pp. eabd1327
Author(s):  
Nicolai Franzmeier ◽  
Anna Dewenter ◽  
Lukas Frontzkowski ◽  
Martin Dichgans ◽  
Anna Rubinski ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Clinical Trials ◽  
Patient Specific ◽  
Braak Stage ◽  
Accumulation Rates ◽  
Patient Centered ◽  
Braak Staging ◽  
Two Samples ◽  
Tau Pet

In Alzheimer’s disease (AD), the Braak staging scheme suggests a stereotypical tau spreading pattern that does, however, not capture interindividual variability in tau deposition. This complicates the prediction of tau spreading, which may become critical for defining individualized tau-PET readouts in clinical trials. Since tau is assumed to spread throughout connected regions, we used functional connectivity to improve tau spreading predictions over Braak staging methods. We included two samples with longitudinal tau-PET from controls and AD patients. Cross-sectionally, we found connectivity of tau epicenters (i.e., regions with earliest tau) to predict estimated tau spreading sequences. Longitudinally, we found tau accumulation rates to correlate with connectivity strength to patient-specific tau epicenters. A connectivity-based, patient-centered tau spreading model improved the assessment of tau accumulation rates compared to Braak stage–specific readouts and reduced sample sizes by ~40% in simulated tau-targeting interventions. Thus, connectivity-based tau spreading models may show utility in clinical trials.

scholarly journals FDG-PET hypermetabolism is associated with higher tau-PET in mild cognitive impairment at low amyloid-PET levels

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Anna Rubinski ◽  
◽  
Nicolai Franzmeier ◽  
Julia Neitzel ◽  
Michael Ewers
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Episodic Memory ◽  
Fdg Pet ◽  
Brain Regions ◽  
Amyloid Pet ◽  
Cognitively Normal ◽  
Posterior Parietal ◽  
Tau Pet ◽  
Fluid Biomarker

Abstract Background FDG-PET hypermetabolism can be observed in mild cognitive impairment (MCI), but the link to primary pathologies of Alzheimer’s diseases (AD) including amyloid and tau is unclear. Methods Using voxel-based regression, we assessed local interactions between amyloid- and tau-PET on spatially matched FDG-PET in 72 MCI patients. Control groups included cerebrospinal fluid biomarker characterized cognitively normal (CN, n = 70) and AD dementia subjects (n = 95). Results In MCI, significant amyloid-PET by tau-PET interactions were found in frontal, lateral temporal, and posterior parietal regions, where higher local tau-PET was associated with higher spatially corresponding FDG-PET at low levels of local amyloid-PET. FDG-PET in brain regions with a significant local amyloid- by tau-PET interaction was higher compared to that in CN and AD dementia and associated with lower episodic memory. Conclusion Higher tau-PET in the presence of low amyloid-PET is associated with abnormally increased glucose metabolism that is accompanied by episodic memory impairment.

scholarly journals Lower functional hippocampal redundancy in mild cognitive impairment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Stephanie Langella ◽  
◽  
Muhammad Usman Sadiq ◽  
Peter J. Mucha ◽  
Kelly S. Giovanello ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Cognitive Decline ◽  
Resting State ◽  
Memory Performance ◽  
Potential Mechanism ◽  
Network Efficiency ◽  
Cognitively Normal ◽  
Normal Individuals ◽  
The Relationship

AbstractWith an increasing prevalence of mild cognitive impairment (MCI) and Alzheimer’s disease (AD) in response to an aging population, it is critical to identify and understand neuroprotective mechanisms against cognitive decline. One potential mechanism is redundancy: the existence of duplicate elements within a system that provide alternative functionality in case of failure. As the hippocampus is one of the earliest sites affected by AD pathology, we hypothesized that functional hippocampal redundancy is protective against cognitive decline. We compared hippocampal functional redundancy derived from resting-state functional MRI networks in cognitively normal older adults, with individuals with early and late MCI, as well as the relationship between redundancy and cognition. Posterior hippocampal redundancy was reduced between cognitively normal and MCI groups, plateauing across early and late MCI. Higher hippocampal redundancy was related to better memory performance only for cognitively normal individuals. Critically, functional hippocampal redundancy did not come at the expense of network efficiency. Our results provide support that hippocampal redundancy protects against cognitive decline in aging.

The role of high-mobility group box protein 1 in chronic cerebral hypoperfusion-induced vascular cognitive impairment animals

2019 ◽  
Author(s):  
Amelia Nur Vidyanti ◽  
Jia-Yu Hsieh ◽  
Kun-Ju Lin ◽  
Yao-Ching Fang ◽  
Ismail Setyopranoto ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Cognitive Decline ◽  
High Mobility ◽  
Vascular Cognitive Impairment ◽  
High Mobility Group ◽  
Cerebral Hypoperfusion ◽  
Hippocampal Atrophy ◽  
Amyloid Pet ◽  
Knock Out

Abstract Background: The molecular mechanisms of vascular cognitive impairment (VCI) are diverse and still in puzzle. VCI could be attributed to chronic cerebral hypoperfusion (CCH). CCH may cause a cascade of reactions involved in ischemia and neuro-inflammation which plays important roles in the pathophysiology of VCI. High-mobility group box protein 1 (HMGB1) is a non-histone protein that serves as a damage-associated molecular signal leading to cascades of inflammation. Increased level of HMGB1 has been established in the acute phase of CCH. However, the role of HMGB1 at the chronic phase of CCH remains elucidated. Methods: We performed modified bilateral common carotid artery occlusion (BCCAO) in C57BL/6 mice to induce CCH. We examined the cerebral blood flow (CBF) reduction by laser doppler flowmetry, the protein expression of HMGB1 and its pro-inflammatory cytokines (TNF-a, IL-1b, and IL-6) by western blotting and immunohistochemistry. The brain pathology was assessed by 7T-animal MRI and amyloid-b accumulation was assessed by amyloid-PET scanning. We further evaluated the effect of HMGB1 suppression by injecting CRISPR/Cas9 knock-out plasmid intra-hippocampus bilaterally. Results: There were reduction of CBF up to 50% which persisted three months after CCH. The modified-BCCAO animals developed significant cognitive decline. The 7T-MRI image showed hippocampal atrophy, although the amyloid-PET showed no significant amyloid-beta accumulation. Increased protein levels of HMGB1, TNF-a and IL-1b were found three months after BCCAO. HMGB1 suppression by CRISPR/Cas9 knock-out plasmid restored the CBF, IL-1B, TNF-alpha, IL-6, and attenuated hippocampal atrophy and cognitive decline. Conclusion: HMGB1 plays a pivotal role in the pathophysiology of the animal model of CCH and it might be a candidate as therapeutic targets of VCI.

scholarly journals Association of CSF Aβ, amyloid PET, and cognition in cognitively unimpaired elderly adults

Neurology ◽  
2020 ◽  
Vol 95 (15) ◽  
pp. e2075-e2085 ◽  
Author(s):  
Tengfei Guo ◽  
Leslie M. Shaw ◽  
John Q. Trojanowski ◽  
William J. Jagust ◽  
Susan M. Landau ◽  
...  
Keyword(s):  
Cognitive Decline ◽  
Amyloid Pet ◽  
Elderly Adults ◽  
Cognitively Normal ◽  
Longitudinal Measurements ◽  
Normal Individuals ◽  
Aβ Amyloid ◽  
Discordant Group ◽  
Amyloid Aβ ◽  
The Relationship

ObjectiveTo compare CSF β-amyloid (Aβ) and florbetapir PET measurements in cognitively unimpaired (CU) elderly adults in order to detect the earliest abnormalities and compare their predictive effect for cognitive decline.MethodsA total of 259 CU individuals were categorized as abnormal (+) or normal (−) on CSF Aβ1-42/Aβ1-40 analyzed with mass spectrometry and Aβ PET measured with 18F-florbetapir. Simultaneous longitudinal measurements of CSF and PET were compared for 39 individuals who were unambiguously Aβ-negative at baseline (CSF−/PET−). We also examined the relationship between baseline CSF/PET group membership and longitudinal changes in CSF Aβ, Aβ PET, and cognition.ResultsThe proportions of individuals in each discordant group were similar (8.1% CSF+/PET− and 7.7% CSF−/PET+). Among baseline Aβ-negative (CSF−/PET−) individuals with longitudinal CSF and PET measurements, a larger proportion subsequently worsened on CSF Aβ (odds ratio 4 [95% confidence interval (CI) 1.1, 22.1], p = 0.035) than Aβ PET over 3.5 ± 1.0 years. Compared to CSF−/PET− individuals, CSF+/PET− individuals had faster (estimate 0.009 [95% CI 0.005, 0.013], p < 0.001) rates of Aβ PET accumulation over 4.4 ± 1.7 years, while CSF−/PET+ individuals had faster (estimate −0.492 [95% CI −0.861, −0.123], p = 0.01) rates of cognitive decline over 4.5 ± 1.9 years.ConclusionsThe proportions of discordant PET and CSF Aβ-positive individuals were similar cross-sectionally. However, unambiguously Aβ-negative (CSF−/PET−) individuals are more likely to show subsequent worsening on CSF than PET, supporting the idea that CSF detects the earliest Aβ changes. In discordant cases, only PET abnormality predicted cognitive decline, suggesting that abnormal Aβ PET changes are a later phenomenon in cognitively normal individuals.

scholarly journals Association of amyloid-β CSF/PET discordance and tau load 5 years later

Neurology ◽  
2020 ◽  
Vol 95 (19) ◽  
pp. e2648-e2657 ◽  
Author(s):  
Juhan Reimand ◽  
Lyduine Collij ◽  
Philip Scheltens ◽  
Femke Bouwman ◽  
Rik Ossenkoppele ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Amyloid Β ◽  
Csf Biomarkers ◽  
Tau Pathology ◽  
Cognitively Normal ◽  
Amyloid Aβ ◽  
Β Amyloid ◽  
Tau Pet

ObjectiveTo investigate the association between discordant β-amyloid (Aβ) PET and CSF biomarkers at baseline and the emergence of tau pathology 5 years later.MethodsWe included 730 Alzheimer's Disease Neuroimaging Initiative (ADNI) participants without dementia (282 cognitively normal, 448 mild cognitive impairment) with baseline [18F]florbetapir PET and CSF Aβ42 available. Aβ CSF/PET status was determined at baseline using established cutoffs. Longitudinal data were available for [18F]florbetapir (Aβ) PET (baseline to 4.3 ± 1.9 years), CSF (p)tau (baseline to 2.0 ± 0.1 years), cognition (baseline to 4.3 ± 2.0 years), and [18F]flortaucipir (tau) PET (measured 5.2 ± 1.2 years after baseline to 1.6 ± 0.7 years later). We used linear mixed modeling to study the association between Aβ CSF/PET status and tau pathology measured in CSF or using PET. We calculated the proportion of CSF+/PET− participants who during follow-up (1) progressed to Aβ CSF+/PET+ or (2) became tau-positive based on [18F]flortaucipir PET.ResultsAβ CSF+/PET+ (n = 318) participants had elevated CSF (p)tau levels and worse cognitive performance at baseline, while CSF+/PET− (n = 80) participants were overall similar to the CSF−/PET− (N = 306) group. Five years after baseline, [18F]flortaucipir PET uptake in the CSF+/PET− group (1.20 ± 0.13) did not differ from CSF−/PET− (1.18 ± 0.08, p = 0.69), but was substantially lower than CSF+/PET+ (1.48 ± 0.44, p < 0.001). Of the CSF+/PET− participants, 21/64 (33%) progressed to Aβ CSF+/PET+, whereas only one (3%, difference p < 0.05) became tau-positive based on [18F]flortaucipir PET.ConclusionsAβ load detectable by both CSF and PET seems to precede substantial tau deposition. Compared to participants with abnormal Aβ levels on both PET and CSF, the CSF+/PET− group has a distinctly better prognosis.

scholarly journals 18F-MK-6240 PET for early and late detection of neurofibrillary tangles

Brain ◽  
2020 ◽  
Vol 143 (9) ◽  
pp. 2818-2830 ◽  
Author(s):  
Tharick A Pascoal ◽  
Joseph Therriault ◽  
Andrea L Benedet ◽  
Melissa Savard ◽  
Firoza Z Lussier ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Amyloid Β ◽  
Standardized Uptake Value ◽  
Braak Staging ◽  
High Affinity ◽  
Tau Pet ◽  
Transentorhinal Cortex

Abstract Braak stages of tau neurofibrillary tangle accumulation have been incorporated in the criteria for the neuropathological diagnosis of Alzheimer’s disease. It is expected that Braak staging using brain imaging can stratify living individuals according to their individual patterns of tau deposition, which may prove crucial for clinical trials and practice. However, previous studies using the first-generation tau PET agents have shown a low sensitivity to detect tau pathology in areas corresponding to early Braak histopathological stages (∼20% of cognitively unimpaired elderly with tau deposition in regions corresponding to Braak I–II), in contrast to ∼80–90% reported in post-mortem cohorts. Here, we tested whether the novel high affinity tau tangles tracer 18F-MK-6240 can better identify individuals in the early stages of tau accumulation. To this end, we studied 301 individuals (30 cognitively unimpaired young, 138 cognitively unimpaired elderly, 67 with mild cognitive impairment, 54 with Alzheimer’s disease dementia, and 12 with frontotemporal dementia) with amyloid-β 18F-NAV4694, tau 18F-MK-6240, MRI, and clinical assessments. 18F-MK-6240 standardized uptake value ratio images were acquired at 90–110 min after the tracer injection. 18F-MK-6240 discriminated Alzheimer’s disease dementia from mild cognitive impairment and frontotemporal dementia with high accuracy (∼85–100%). 18F-MK-6240 recapitulated topographical patterns consistent with the six hierarchical stages proposed by Braak in 98% of our population. Cognition and amyloid-β status explained most of the Braak stages variance (P &lt; 0.0001, R2 = 0.75). No single region of interest standardized uptake value ratio accurately segregated individuals into the six topographic Braak stages. Sixty-eight per cent of the cognitively unimpaired elderly amyloid-β-positive and 37% of the cognitively unimpaired elderly amyloid-β-negative subjects displayed tau deposition, at least in the transentorhinal cortex (Braak I). Tau deposition solely in the transentorhinal cortex was associated with an elevated prevalence of amyloid-β, neurodegeneration, and cognitive impairment (P &lt; 0.0001). 18F-MK-6240 deposition in regions corresponding to Braak IV–VI was associated with the highest prevalence of neurodegeneration, whereas in Braak V–VI regions with the highest prevalence of cognitive impairment. Our results suggest that the hierarchical six-stage Braak model using 18F-MK-6240 imaging provides an index of early and late tau accumulation as well as disease stage in preclinical and symptomatic individuals. Tau PET Braak staging using high affinity tracers has the potential to be incorporated in the diagnosis of living patients with Alzheimer’s disease in the near future.

scholarly journals CSF sTREM2 correlates with CSF tau in advancing Parkinson’s disease

2019 ◽  
Author(s):  
Edward N. Wilson ◽  
Michelle S. Swarovski ◽  
Patricia Linortner ◽  
Marian Shahid ◽  
Abigail J. Zuckerman ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Cognitive Decline ◽  
Microglial Activation ◽  
Soluble Form ◽  
Motor Symptoms ◽  
Cognitively Normal ◽  
Csf Concentration

AbstractParkinson’s disease (PD) is the second most common neurodegenerative disease after Alzheimer’s disease (AD) and affects 1% of the population above 60 years old. Although PD commonly manifests with motor symptoms, a majority of patients with PD subsequently develop cognitive impairment which often progresses to dementia, a major cause of morbidity and disability. PD is characterized by α-synuclein accumulation that frequently associates with amyloid beta (Aβ) and tau fibrils, the hallmarks of AD neuropathologic changes; this co-occurrence suggests that onset of cognitive decline in PD may be associated with appearance of pathologic Aβ and/or tau. Recent studies have highlighted the appearance of the soluble form of the Triggering Receptor Expressed on Myeloid cells 2 (sTREM2) receptor in CSF during development of AD. Given the known association of microglial activation with advancing PD, we investigated whether CSF and/or plasma sTREM2 increased with progression to PD dementia. We examined 165 participants consisting of 17 cognitively normal elderly, 45 PD patients with no cognitive impairment, 86 with mild cognitive impairment, and 17 with dementia. Stratification of subjects by CSF Aβ and tau levels revealed that CSF sTREM2 concentrations were elevated in PD subgroups with abnormal tau, but not Aβ, CSF concentration. These findings indicate that CSF sTREM2 could serve as a surrogate immune biomarker of neuronal injury in PD that is associated with cognitive decline.One sentence summaryCSF sTREM2 correlates with CSF tau in PD

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