| 1. |
- Almkvist, Ove, et al.
(author)
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Longitudinal cognitive decline in autosomal-dominant Alzheimer's disease varies with mutations in APP and PSEN1 genes
- 2019
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In: Neurobiology of Aging. - : ELSEVIER SCIENCE INC. - 0197-4580 .- 1558-1497. ; 82, s. 40-47
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Journal article (peer-reviewed)abstract
- The purpose was to compare longitudinal cognitive changes in APP and PSEN1 gene mutation carriers and noncarriers from four autosomal-dominant Alzheimer's disease (ADAD) families across preclinical and early clinical stages of disease. Carriers (n = 34) with four different mutations (PSEN1(M146V), PSEN1(H163Y), APP(SWE), and APP(ARC)) and noncarriers (n = 41) were followed up longitudinally with repeated cognitive assessments starting many years before the expected clinical onset. The relationship between cognition and years to expected clinical onset, education, age, and type of mutation was analyzed using mixed-effects models. Results showed an education-dependent and time-related cognitive decline with linear and quadratic predictors in mutation carriers. Cognitive decline began close to the expected clinical onset and was relatively rapid afterward in PSEN1 mutation carriers, whereas decline was slower and started earlier than 10 years before expected clinical onset in APP mutation carriers. In noncarriers, the decline was minimal across time in accordance with normal aging. These results suggest that phenotypes for onset and rate of cognitive decline vary with PSEN1 and APP genes, suggesting a behavioral heterogeneity in ADAD. (C) 2019 Elsevier Inc. All rights reserved.
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| 2. |
- Almkvist, Ove, et al.
(author)
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Predicting Cognitive Decline across Four Decades in Mutation Carriers and Non-carriers in Autosomal-Dominant Alzheimer's Disease
- 2017
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In: Journal of the International Neuropsychological Society. - : CAMBRIDGE UNIV PRESS. - 1355-6177 .- 1469-7661. ; 23:3, s. 195-203
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Journal article (peer-reviewed)abstract
- Objectives: The aim of this study was to investigate cognitive performance including preclinical and clinical disease course in carriers and non-carriers of autosomal-dominant Alzheimer's disease (adAD) in relation to multiple predictors, that is, linear and non-linear estimates of years to expected clinical onset of disease, years of education and age. Methods: Participants from five families with early-onset autosomal-dominant mutations (Swedish and Arctic APP, PSEN1 M146V, H163Y, and I143T) included 35 carriers (28 without dementia and 7 with) and 44 non-carriers. All participants underwent a comprehensive clinical evaluation, including neuropsychological assessment at the Memory Clinic, Karolinska University Hospital at Huddinge, Stockholm, Sweden. The time span of disease course covered four decades of the preclinical and clinical stages of dementia. Neuropsychological tests were used to assess premorbid and current global cognition, verbal and visuospatial functions, short-term and episodic memory, attention, and executive function. Results: In carriers, the time-related curvilinear trajectory of cognitive function across disease stages was best fitted to a formulae with three predictors: years to expected clinical onset (linear and curvilinear components), and years of education. In non-carriers, the change was minimal and best predicted by two predictors: education and age. The trajectories for carriers and non-carriers began to diverge approximately 10 years before the expected clinical onset in episodic memory, executive function, and visuospatial function. Conclusions: The curvilinear trajectory of cognitive functions across disease stages was mimicked by three predictors in carriers. In episodic memory, executive and visuospatial functions, the point of diverging trajectories occurred approximately 10 years ahead of the clinical onset compared to non-carriers.
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| 3. |
- Farid, Karim, et al.
(author)
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Case Report of Complex Amyotrophic Lateral Sclerosis with Cognitive Impairment and Cortical Amyloid Deposition.
- 2015
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In: Journal of Alzheimer's disease : JAD. - 1875-8908 .- 1387-2877. ; 47:3, s. 661-7
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Journal article (peer-reviewed)abstract
- Amyotrophic lateral sclerosis (ALS), a fatal disease of unknown origin, affects motor neurons in the primary motor cortex, brainstem, and spinal cord. Cognitive impairment may occur before the motor symptoms. We present a patient who was initially diagnosed with mild cognitive impairment (MCI) due to Alzheimer's disease (AD) but who developed ALS-like symptoms during follow-up and died shortly thereafter. A 60-year-old subject with cognitive impairment underwent neuropsychological testing, cerebrospinal fluid (CSF) analysis, structural imaging (computed tomography and magnetic resonance imaging) and functional imaging [11C]-Pittsburgh compound B (PIB) positron emission tomography (PET), [18F]-fluorodeoxyglucose (FDG) PET, and [11C]-deuterium-L-deprenyl (DED) PET. Neuropsychological testing showed episodic memory impairment. CSF P-tau and T-tau levels were elevated. CSF amyloid-β (Aβ)42 levels were initially normal but became pathological during follow-up. MCI was diagnosed. [18F]-FDG PET showed hypometabolism in the left temporal and prefrontal cortices and [11C]-PIB PET demonstrated amyloid plaque deposition in the prefrontal, posterior cingulate, and parietal cortices. [11C]-DED PET showed high brain accumulation consistent with astrocytosis. The memory impairment progressed and AD was diagnosed. Motor impairments developed subsequently and, following additional neurological evaluation, ALS was diagnosed. The disease progressed rapidly and the patient died with pronounced motor symptoms three years after the initial cognitive assessment. Since relatives refused autopsy, postmortem analysis was not possible.
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| 4. |
- Leuzy, Antoine, et al.
(author)
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Longitudinal uncoupling of cerebral perfusion, glucose metabolism, and tau deposition in Alzheimer's disease
- 2018
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In: Alzheimer's & Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 14:5, s. 652-663
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Journal article (peer-reviewed)abstract
- Introduction: Cross-sectional findings using the tau tracer [F-18] THK5317 (THK5317) have shown that [F-18]fluorodeoxyglucose (FDG) positron emission tomography (PET) data can be approximated using perfusion measures (early-frame standardized uptake value ratio; ratio of tracer delivery in target to reference regions). In this way, a single PET study can provide both functional and molecular information. Methods: We included 16 patients with Alzheimer's disease who completed follow-up THK5317 and FDG studies 17 months after baseline investigations. Linear mixed-effects models and annual percentage change maps were used to examine longitudinal change. Results: Limited spatial overlap was observed between areas showing declines in THK5317 perfusion measures and FDG. Minimal overlap was seen between areas showing functional change and those showing increased retention of THK5317. Discussion: Our findings suggest a spatiotemporal offset between functional changes and tau pathology and a partial uncoupling between perfusion and metabolism, possibly as a function of Alzheimer's disease severity.
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| 5. |
- Leuzy, Antoine, et al.
(author)
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Tau PET imaging in neurodegenerative tauopathies-still a challenge
- 2019
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In: Molecular Psychiatry. - : Springer Science and Business Media LLC. - 1359-4184 .- 1476-5578. ; 24:8, s. 1112-1134
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Research review (peer-reviewed)abstract
- The accumulation of pathological misfolded tau is a feature common to a collective of neurodegenerative disorders known as tauopathies, of which Alzheimer's disease (AD) is the most common. Related tauopathies include progressive supranuclear palsy (PSP), corticobasal syndrome (CBS), Down's syndrome (DS), Parkinson's disease (PD), and dementia with Lewy bodies (DLB). Investigation of the role of tau pathology in the onset and progression of these disorders is now possible due the recent advent of tau-specific ligands for use with positron emission tomography (PET), including first-(e.g., [F-18] THK5317, [F-18] THK5351, [F-18] AV1451, and [C-11] PBB3) and second-generation compounds [namely [F-18] MK-6240, [F-18] RO-948 (previously referred to as [F-18] RO69558948), [F-18] PI-2620, [F-18] GTP1, [F-18] PM-PBB3, and [F-18] JNJ64349311 ([F-18] JNJ311) and its derivative [F-18] JNJ-067)]. In this review we describe and discuss findings from in vitro and in vivo studies using both initial and new tau ligands, including their relation to biomarkers for amyloid-beta and neurodegeneration, and cognitive findings. Lastly, methodological considerations for the quantification of in vivo ligand binding are addressed, along with potential future applications of tau PET, including therapeutic trials.
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| 6. |
- Månberg, Anna, 1985-, et al.
(author)
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Altered perivascular fibroblast activity precedes ALS disease onset
- 2021
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In: Nature Medicine. - : Nature Publishing Group. - 1078-8956 .- 1546-170X. ; 27:4, s. 640-646
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Journal article (peer-reviewed)abstract
- Apart from well-defined factors in neuronal cells1, only a few reports consider that the variability of sporadic amyotrophic lateral sclerosis (ALS) progression can depend on less-defined contributions from glia2,3 and blood vessels4. In this study we use an expression-weighted cell-type enrichment method to infer cell activity in spinal cord samples from patients with sporadic ALS and mouse models of this disease. Here we report that patients with sporadic ALS present cell activity patterns consistent with two mouse models in which enrichments of vascular cell genes preceded microglial response. Notably, during the presymptomatic stage, perivascular fibroblast cells showed the strongest gene enrichments, and their marker proteins SPP1 and COL6A1 accumulated in enlarged perivascular spaces in patients with sporadic ALS. Moreover, in plasma of 574 patients with ALS from four independent cohorts, increased levels of SPP1 at disease diagnosis repeatedly predicted shorter survival with stronger effect than the established risk factors of bulbar onset or neurofilament levels in cerebrospinal fluid. We propose that the activity of the recently discovered perivascular fibroblast can predict survival of patients with ALS and provide a new conceptual framework to re-evaluate definitions of ALS etiology.
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| 7. |
- Natarajan Arul, Murugan, et al.
(author)
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Cross-interaction of tau PET tracers with monoamine oxidase B : evidence from in silico modelling and in vivo imaging
- 2019
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In: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer. - 1619-7070 .- 1619-7089. ; 46:6, s. 1369-1382
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Journal article (peer-reviewed)abstract
- PurposeSeveral tracers have been designed for tracking the abnormal accumulation of tau pathology in vivo. Recently, concerns have been raised about the sources of off-target binding for these tracers; inconclusive data propose binding for some tracers to monoamine oxidase B (MAO-B).MethodsMolecular docking and dynamics simulations were used to estimate the affinity and free energy for the binding of several tau tracers (FDDNP, THK523, THK5105, THK5317, THK5351, T807 [aka AV-1451, flortaucipir], T808, PBB3, RO-948, MK-6240, JNJ-311 and PI-2620) to MAO-B. These values were then compared with those for safinamide (MAO-B inhibitor). PET imaging was used with the tau tracer [F-18]THK5317 and the MAO-B tracer [C-11]DED in five patients with Alzheimer's disease to investigate the MAO-B binding component of this first generation tau tracer in vivo.ResultsThe computational modelling studies identified a binding site for all the tau tracers on MAO-B; this was the same site as that for safinamide. The binding affinity and free energy of binding for the tau tracers to MAO-B was substantial and in a similar range to those for safinamide. The most recently developed tau tracers MK-6240, JNJ-311 and PI-2620 appeared, in silico, to have the lowest relative affinity for MAO-B. The in vivo investigations found that the regional distribution of binding for [F-18]THK5317 was different from that for [C-11]DED, although areas of suspected off-target [F-18]THK5317 binding were detected. The binding relationship between [F-18]THK5317 and [C-11]DED depended on the availability of the MAO-B enzyme.ConclusionsThe developed tau tracers show in silico and in vivo evidence of cross-interaction with MAO-B; the MAO-B component of the tracer binding was dependent on the regional concentration of the enzyme.
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| 8. |
- Rodriguez-Vieitez, Elena, et al.
(author)
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Comparability of [F-18]THK5317 and [C-11]PIB blood flow proxy images with [F-18]FDG positron emission tomography in Alzheimer's disease
- 2017
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In: Journal of Cerebral Blood Flow and Metabolism. - : SAGE PUBLICATIONS INC. - 0271-678X .- 1559-7016. ; 37:2, s. 740-749
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Journal article (peer-reviewed)abstract
- For amyloid positron emission tomography tracers, the simplified reference tissue model derived ratio of influx rate in target relative to reference region (R-1) has been shown to serve as a marker of brain perfusion, and, due to the strong coupling between perfusion and metabolism, as a proxy for glucose metabolism. In the present study, 11 prodromal Alzheimer's disease and nine Alzheimer's disease dementia patients underwent [F-18]THK5317, carbon-11 Pittsburgh Compound-B ([C-11]PIB), and 2-deoxy-2-[F-18]fluoro-D-glucose ([F-18]FDG) positron emission tomography to assess the possible use of early-phase [F-18]THK5317 and R-1 as proxies for brain perfusion, and thus, for glucose metabolism. Discriminative performance (prodromal vs Alzheimer's disease dementia) of [F-18]THK5317 (early-phase SUVr and R-1) was compared with that of [C-11]PIB (early-phase SUVr and R-1) and [F-18]FDG. Strong positive correlations were found between [F-18]THK5317 (early-phase, R-1) and [F-18]FDG, particularly in frontal and temporoparietal regions. Differences in correlations between early-phase and R-1 ([F-18]THK5317 and [C-11]PIB) and [F-18]FDG, were not statistically significant, nor were differences in area under the curve values in the discriminative analysis. Our findings suggest that early-phase [F-18]THK5317 and R-1 provide information on brain perfusion, closely related to glucose metabolism. As such, a single positron emission tomography study with [F-18]THK5317 may provide information about both tau pathology and brain perfusion in Alzheimer's disease, with potential clinical applications.
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| 9. |
- Rodriguez-Vieitez, Elena, et al.
(author)
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Comparison of Early-Phase C-11-Deuterium-L-Deprenyl and C-11-Pittsburgh Compound B PET for Assessing Brain Perfusion in Alzheimer Disease
- 2016
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In: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 1535-5667 .- 2159-662X. ; 57:7, s. 1071-1077
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Journal article (peer-reviewed)abstract
- The PET tracer C-11-deuterium-L-deprenyl (C-11-DED) has been used to visualize activated astrocytes in vivo in patients with Alzheimer disease (AD). In this multitracer PET study, early-phase C-11-DED and C-11-Pittsburgh compound B (C-11-PiB) (eDED and ePiB, respectively) were compared as surrogate markers of brain perfusion, and the extent to which C-11-DED binding is influenced by brain perfusion was investigated. METHODS: C-11-DED, C-11-PiB, and F-18-FDG dynamic PET scans were obtained in age-matched groups comprising AD patients (n = 8), patients with mild cognitive impairment (n = 17), and healthy controls (n = 16). A modified reference Patlak model was used to quantify C-11-DED binding. A simplified reference tissue model was applied to both C-11-DED and C-11-PiB to measure brain perfusion relative to the cerebellar gray matter (R-1) and binding potentials. C-11-PiB retention and F-18-FDG uptake were also quantified as target-to-pons SUV ratios in 12 regions of interest (ROIs). RESULTS: The strongest within-subject correlations with the corresponding R-1 values (R-1,R-DED and R-1,R-PiB, respectively) and with F-18-FDG uptake were obtained when the eDED and ePiB PET data were measured 1-4 min after injection. The optimum eDED/ePiB intervals also showed strong, significant ROI-based intersubject Pearson correlations with R-1,R-DED/R-1,R-PiB and with F-18-FDG uptake, whereas C-11-DED binding was largely independent of brain perfusion, as measured by eDED. Corresponding voxelwise correlations confirmed the ROI-based results. Temporoparietal eDED or ePiB brain perfusion measurements were highly discriminative between patient and control groups, with discriminative ability statistically comparable to that of temporoparietal F-18-FDG glucose metabolism. Hypometabolism extended over wider regions than hypoperfusion in patient groups compared with controls. CONCLUSION: The 1- to 4-min early-frame intervals of C-11-DED or C-11-PiB are suitable surrogate measures for brain perfusion. C-11-DED binding is independent of brain perfusion, and thus C-11-DED PET can provide information on both functional (brain perfusion) and pathologic (astrocytosis) aspects from a single PET scan. In comparison with glucose metabolism, early-phase C-11-DED and C-11-PiB perfusion appear to provide complementary rather than redundant information.
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| 10. |
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| 11. |
- Rodriguez-Vieitez, Elena, et al.
(author)
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Diverging longitudinal changes in astrocytosis and amyloid PET in autosomal dominant Alzheimer's disease
- 2016
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In: Brain. - : Oxford University Press (OUP). - 0006-8950 .- 1460-2156. ; 139:3, s. 922-936
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Journal article (peer-reviewed)abstract
- The relationships between pathophysiological processes in Alzheimer's disease remain largely unclear. In a longitudinal, multitracer PET study, Rodriguez-Vieitez et al. reveal that progression of autosomal dominant Alzheimer's disease is accompanied by prominent early and then declining astrocytosis, increasing amyloid plaque deposition and decreasing glucose metabolism. Astrocyte activation may initiate Alzheimer pathology.See Schott and Fox (doi: 10.1093/brain/awv405) for a scientific commentary on this article. The relationships between pathophysiological processes in Alzheimer's disease remain largely unclear. In a longitudinal, multitracer PET study, Rodriguez-Vieitez et al. reveal that progression of autosomal dominant Alzheimer's disease is accompanied by prominent early and then declining astrocytosis, increasing amyloid plaque deposition and decreasing glucose metabolism. Astrocyte activation may initiate Alzheimer pathology.Alzheimer's disease is a multifactorial dementia disorder characterized by early amyloid-beta, tau deposition, glial activation and neurodegeneration, where the interrelationships between the different pathophysiological events are not yet well characterized. In this study, longitudinal multitracer positron emission tomography imaging of individuals with autosomal dominant or sporadic Alzheimer's disease was used to quantify the changes in regional distribution of brain astrocytosis (tracer C-11-deuterium-L-deprenyl), fibrillar amyloid-beta plaque deposition (C-11-Pittsburgh compound B), and glucose metabolism (F-18-fluorodeoxyglucose) from early presymptomatic stages over an extended period to clinical symptoms. The 52 baseline participants comprised autosomal dominant Alzheimer's disease mutation carriers (n = 11; 49.6 +/- 10.3 years old) and non-carriers (n = 16; 51.1 +/- 14.2 years old; 10 male), and patients with sporadic mild cognitive impairment (n = 17; 61.9 +/- 6.4 years old; nine male) and sporadic Alzheimer's disease (n = 8; 63.0 +/- 6.5 years old; five male); for confidentiality reasons, the gender of mutation carriers is not revealed. The autosomal dominant Alzheimer's disease participants belonged to families with known mutations in either presenilin 1 (PSEN1) or amyloid precursor protein (APPswe or APParc) genes. Sporadic mild cognitive impairment patients were further divided into C-11-Pittsburgh compound B-positive (n = 13; 62.0 +/- 6.4; seven male) and C-11-Pittsburgh compound B-negative (n = 4; 61.8 +/- 7.5 years old; two male) groups using a neocortical standardized uptake value ratio cut-off value of 1.41, which was calculated with respect to the cerebellar grey matter. All baseline participants underwent multitracer positron emission tomography scans, cerebrospinal fluid biomarker analysis and neuropsychological assessment. Twenty-six of the participants underwent clinical and imaging follow-up examinations after 2.8 +/- 0.6 years. By using linear mixed-effects models, fibrillar amyloid-beta plaque deposition was first observed in the striatum of presymptomatic autosomal dominant Alzheimer's disease carriers from 17 years before expected symptom onset; at about the same time, astrocytosis was significantly elevated and then steadily declined. Diverging from the astrocytosis pattern, amyloid-beta plaque deposition increased with disease progression. Glucose metabolism steadily declined from 10 years after initial amyloid-beta plaque deposition. Patients with sporadic mild cognitive impairment who were C-11-Pittsburgh compound B-positive at baseline showed increasing amyloid-beta plaque deposition and decreasing glucose metabolism but, in contrast to autosomal dominant Alzheimer's disease carriers, there was no significant longitudinal decline in astrocytosis over time. The prominent initially high and then declining astrocytosis in autosomal dominant Alzheimer's disease carriers, contrasting with the increasing amyloid-beta plaque load during disease progression, suggests astrocyte activation is implicated in the early stages of Alzheimer's disease pathology.
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| 12. |
- Thordardottir, Steinunn, et al.
(author)
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Reduced penetrance of the PSEN1 H163Y autosomal dominant Alzheimer mutation : A 22-year follow-up study
- 2018
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In: Alzheimer's Research & Therapy. - : Springer Science and Business Media LLC. - 1758-9193. ; 10
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Journal article (peer-reviewed)abstract
- Background: The range of onset ages within some PSEN1 families is wide, and a few cases of reduced penetrance of PSEN1 mutations have been reported. However, published data on reduced penetrance have been limited to clinical histories, often collected retrospectively and lacking biomarker information. We present a case of reduced penetrance of the PSEN1 H163Y mutation in a carrier prospectively followed for 22 years. Methods: Two brothers (A and B), both carriers of the H163Y mutation, were followed between 1995 and 2017. They underwent repeated clinical evaluations, neuropsychological assessments, and cerebrospinal fluid analyses, as well as brain imaging examinations with structural magnetic resonance, [F-18] fluorodeoxyglucose positron emission tomography, and [C-11] Pittsburgh compound B positron emission tomography. Results: Brother A was followed between 44 and 64 years of age. Cognitive symptoms due to Alzheimer's disease set in at the age of 54. Gradual worsening of symptoms resulted in admittance to a nursing home owing to dependence on others for all activities of daily living. He showed a curvilinear decline in cognitive function on neuropsychological tests, and changes on magnetic resonance imaging, positron emission tomography, and biomarkers in the cerebrospinal fluid supported a clinical diagnosis of Alzheimer's disease. Brother A died at the age of 64 and fulfilled the criteria for definitive Alzheimer's disease according to neuropathological examination results. Brother B was followed between the ages of 43 and 65 and showed no cognitive deterioration on repeated neuropsychological test occasions. In addition, no biomarker evidence of Alzheimer's disease pathology was detected, either on imaging examinations or in cerebrospinal fluid. Conclusions: The average (SD) age of symptom onset for PSEN1 H163Y is 51 +/- 7 years according to previous studies. However, we present a case of a biomarker-verified reduction in penetrance in a mutation carrier who was still symptom-free at the age of 65. This suggests that other genetic, epigenetic, and/or environmental factors modify the onset age.
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| 13. |
- Twohig, Daniel, et al.
(author)
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The relevance of cerebrospinal fluid α-synuclein levels to sporadic and familial Alzheimer's disease
- 2018
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In: Acta neuropathologica communications. - : Springer Science and Business Media LLC. - 2051-5960. ; 6
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Journal article (peer-reviewed)abstract
- Accumulating evidence demonstrating higher cerebrospinal fluid (CSF) -synuclein (Syn) levels and Syn pathology in the brains of Alzheimer's disease (AD) patients suggests that Syn is involved in the pathophysiology of AD. To investigate whether Syn could be related to specific aspects of the pathophysiology present in both sporadic and familial disease, we quantified CSF levels of Syn and assessed links to various disease parameters in a longitudinally followed cohort (n=136) including patients with sporadic mild cognitive impairment (MCI) and AD, and in a cross-sectional sample from the Dominantly Inherited Alzheimer's Network (n=142) including participants carrying autosomal dominant AD (ADAD) gene mutations and their non-mutation carrying family members.Our results show that sporadic MCI patients that developed AD over a period of two years exhibited higher baseline Syn levels (p=0.03), which inversely correlated to their Mini-Mental State Examination scores, compared to cognitively normal controls (p=0.02). In the same patients, there was a dose-dependent positive association between CSF Syn and the APOE epsilon 4 allele. Further, CSF Syn levels were higher in symptomatic ADAD mutation carriers versus non-mutation carriers (p=0.03), and positively correlated to the estimated years from symptom onset (p=0.05) across all mutation carriers. In asymptomatic (Clinical Dementia Rating<0.5) PET amyloid-positive ADAD mutation carriers CSF Syn was positively correlated to C-11-Pittsburgh Compound-B (PiB) retention in several brain regions including the posterior cingulate, superior temporal and frontal cortical areas. Importantly, APOE epsilon 4-positive ADAD mutation carriers exhibited an association between CSF Syn levels and mean cortical PiB retention (p=0.032). In both the sporadic AD and ADAD cohorts we found several associations predominantly between CSF levels of Syn, tau and amyloid-(1-40).Our results suggest that higher CSF Syn levels are linked to AD pathophysiology at the early stages of disease development and to the onset of cognitive symptoms in both sporadic and autosomal dominant AD. We conclude that APOE epsilon 4 may promote the processes driven by Syn, which in turn may reflect on molecular mechanisms linked to the asymptomatic build-up of amyloid plaque burden in brain regions involved in the early stages of AD development.
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| 14. |
- Vilaplana, Eduard, et al.
(author)
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Cortical microstructural correlates of astrocytosis in autosomal-dominant Alzheimer disease
- 2020
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In: Neurology. - : LIPPINCOTT WILLIAMS & WILKINS. - 0028-3878 .- 1526-632X. ; 94:19, s. e2026-E2036
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Journal article (peer-reviewed)abstract
- Objective: To study the macrostructural and microstructural MRI correlates of brain astrocytosis, measured with C-11-deuterium-L-deprenyl (C-11-DED)-PET, in familial autosomal-dominant Alzheimer disease (ADAD).Methods: The total sample (n = 31) comprised ADAD mutation carriers (n = 10 presymptomatic, 39.2 10.6 years old; n = 3 symptomatic, 55.5 2.0 years old) and noncarriers (n = 18, 44.0 +/- 13.7 years old) belonging to families with mutations in either the presenilin-1 or amyloid precursor protein genes. All participants underwent structural and diffusion MRI and neuropsychological assessment, and 20 participants (6 presymptomatic and 3 symptomatic mutation carriers and 11 noncarriers) also underwent C-11-DED-PET.Results: Vertex-wise interaction analyses revealed a differential relationship between carriers and noncarriers in the association between C-11-DED binding and estimated years to onset (EYO) and between cortical mean diffusivity (MD) and EYO. These differences were due to higher C-11-DED binding in presymptomatic carriers, with lower binding in symptomatic carriers compared to noncarriers, and to lower cortical MD in presymptomatic carriers, with higher MD in symptomatic carriers compared to noncarriers. Using a vertex-wise local correlation approach, C-11-DED binding was negatively correlated with cortical MD and positively correlated with cortical thickness.Conclusions: Our proof-of-concept study is the first to show that microstructural and macrostructural changes can reflect underlying neuroinflammatory mechanisms in early stages of Alzheimer disease (AD). The findings support a role for neuroinflammation in AD pathogenesis, with potential implications for the correct interpretation of neuroimaging biomarkers as surrogate endpoints in clinical trials.
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