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| 2. |
- Farid, Karim, et al.
(författare)
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Case Report of Complex Amyotrophic Lateral Sclerosis with Cognitive Impairment and Cortical Amyloid Deposition.
- 2015
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Ingår i: Journal of Alzheimer's disease : JAD. - 1875-8908 .- 1387-2877. ; 47:3, s. 661-7
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Tidskriftsartikel (refereegranskat)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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| 3. |
- Herukka, Sanna-Kaisa, et al.
(författare)
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Recommendations for cerebrospinal fluid Alzheimer's disease biomarkers in the diagnostic evaluation of mild cognitive impairment.
- 2017
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Ingår i: Alzheimer's & dementia : the journal of the Alzheimer's Association. - : Wiley. - 1552-5279. ; 13:3, s. 285-295
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Tidskriftsartikel (refereegranskat)abstract
- This article presents recommendations, based on the Grading of Recommendations, Assessment, Development, and Evaluation method, for the clinical application of cerebrospinal fluid (CSF) amyloid-β1-42, tau, and phosphorylated tau in the diagnostic evaluation of patients with mild cognitive impairment (MCI). The recommendations were developed by a multidisciplinary working group and based on the available evidence and consensus from focused group discussions for 1) prediction of clinical progression to Alzheimer's disease (AD) dementia, 2) cost-effectiveness, 3) interpretation of results, and 4) patient counseling. The working group recommended using CSF AD biomarkers in the diagnostic workup of MCI patients, after prebiomarker counseling, as an add-on to clinical evaluation to predict functional decline or conversion to AD dementia and to guide disease management. Because of insufficient evidence, it was uncertain whether CSF AD biomarkers outperform imaging biomarkers. Furthermore, the working group provided recommendations for interpretation of ambiguous CSF biomarker results and for pre- and post-biomarker counseling.
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| 4. |
- Jansen, Willemijn J, et al.
(författare)
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Association of Cerebral Amyloid-β Aggregation With Cognitive Functioning in Persons Without Dementia.
- 2018
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Ingår i: JAMA psychiatry. - : American Medical Association (AMA). - 2168-6238 .- 2168-622X. ; 75:1, s. 84-95
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Tidskriftsartikel (refereegranskat)abstract
- Cerebral amyloid-β aggregation is an early event in Alzheimer disease (AD). Understanding the association between amyloid aggregation and cognitive manifestation in persons without dementia is important for a better understanding of the course of AD and for the design of prevention trials.To investigate whether amyloid-β aggregation is associated with cognitive functioning in persons without dementia.This cross-sectional study included 2908 participants with normal cognition and 4133 with mild cognitive impairment (MCI) from 53 studies in the multicenter Amyloid Biomarker Study. Normal cognition was defined as having no cognitive concerns for which medical help was sought and scores within the normal range on cognitive tests. Mild cognitive impairment was diagnosed according to published criteria. Study inclusion began in 2013 and is ongoing. Data analysis was performed in January 2017.Global cognitive performance as assessed by the Mini-Mental State Examination (MMSE) and episodic memory performance as assessed by a verbal word learning test. Amyloid aggregation was measured with positron emission tomography or cerebrospinal fluid biomarkers and dichotomized as negative (normal) or positive (abnormal) according to study-specific cutoffs. Generalized estimating equations were used to examine the association between amyloid aggregation and low cognitive scores (MMSE score ≤27 or memory z score≤-1.28) and to assess whether this association was moderated by age, sex, educational level, or apolipoprotein E genotype.Among 2908 persons with normal cognition (mean [SD] age, 67.4 [12.8] years), amyloid positivity was associated with low memory scores after age 70 years (mean difference in amyloid positive vs negative, 4% [95% CI, 0%-7%] at 72 years and 21% [95% CI, 10%-33%] at 90 years) but was not associated with low MMSE scores (mean difference, 3% [95% CI, -1% to 6%], P=.16). Among 4133 patients with MCI (mean [SD] age, 70.2 [8.5] years), amyloid positivity was associated with low memory (mean difference, 16% [95% CI, 12%-20%], P<.001) and low MMSE (mean difference, 14% [95% CI, 12%-17%], P<.001) scores, and this association decreased with age. Low cognitive scores had limited utility for screening of amyloid positivity in persons with normal cognition and those with MCI. In persons with normal cognition, the age-related increase in low memory score paralleled the age-related increase in amyloid positivity with an intervening period of 10 to 15 years.Although low memory scores are an early marker of amyloid positivity, their value as a screening measure for early AD among persons without dementia is limited.
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| 5. |
- Jansen, Willemijn J, et al.
(författare)
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Prevalence Estimates of Amyloid Abnormality Across the Alzheimer Disease Clinical Spectrum.
- 2022
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Ingår i: JAMA neurology. - : American Medical Association (AMA). - 2168-6157 .- 2168-6149. ; 79:3, s. 228-243
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Tidskriftsartikel (refereegranskat)abstract
- One characteristic histopathological event in Alzheimer disease (AD) is cerebral amyloid aggregation, which can be detected by biomarkers in cerebrospinal fluid (CSF) and on positron emission tomography (PET) scans. Prevalence estimates of amyloid pathology are important for health care planning and clinical trial design.To estimate the prevalence of amyloid abnormality in persons with normal cognition, subjective cognitive decline, mild cognitive impairment, or clinical AD dementia and to examine the potential implications of cutoff methods, biomarker modality (CSF or PET), age, sex, APOE genotype, educational level, geographical region, and dementia severity for these estimates.This cross-sectional, individual-participant pooled study included participants from 85 Amyloid Biomarker Study cohorts. Data collection was performed from January 1, 2013, to December 31, 2020. Participants had normal cognition, subjective cognitive decline, mild cognitive impairment, or clinical AD dementia. Normal cognition and subjective cognitive decline were defined by normal scores on cognitive tests, with the presence of cognitive complaints defining subjective cognitive decline. Mild cognitive impairment and clinical AD dementia were diagnosed according to published criteria.Alzheimer disease biomarkers detected on PET or in CSF.Amyloid measurements were dichotomized as normal or abnormal using cohort-provided cutoffs for CSF or PET or by visual reading for PET. Adjusted data-driven cutoffs for abnormal amyloid were calculated using gaussian mixture modeling. Prevalence of amyloid abnormality was estimated according to age, sex, cognitive status, biomarker modality, APOE carrier status, educational level, geographical location, and dementia severity using generalized estimating equations.Among the 19097 participants (mean [SD] age, 69.1 [9.8] years; 10148 women [53.1%]) included, 10139 (53.1%) underwent an amyloid PET scan and 8958 (46.9%) had an amyloid CSF measurement. Using cohort-provided cutoffs, amyloid abnormality prevalences were similar to 2015 estimates for individuals without dementia and were similar across PET- and CSF-based estimates (24%; 95% CI, 21%-28%) in participants with normal cognition, 27% (95% CI, 21%-33%) in participants with subjective cognitive decline, and 51% (95% CI, 46%-56%) in participants with mild cognitive impairment, whereas for clinical AD dementia the estimates were higher for PET than CSF (87% vs 79%; mean difference, 8%; 95% CI, 0%-16%; P=.04). Gaussian mixture modeling-based cutoffs for amyloid measures on PET scans were similar to cohort-provided cutoffs and were not adjusted. Adjusted CSF cutoffs resulted in a 10% higher amyloid abnormality prevalence than PET-based estimates in persons with normal cognition (mean difference, 9%; 95% CI, 3%-15%; P=.004), subjective cognitive decline (9%; 95% CI, 3%-15%; P=.005), and mild cognitive impairment (10%; 95% CI, 3%-17%; P=.004), whereas the estimates were comparable in persons with clinical AD dementia (mean difference, 4%; 95% CI, -2% to 9%; P=.18).This study found that CSF-based estimates using adjusted data-driven cutoffs were up to 10% higher than PET-based estimates in people without dementia, whereas the results were similar among people with dementia. This finding suggests that preclinical and prodromal AD may be more prevalent than previously estimated, which has important implications for clinical trial recruitment strategies and health care planning policies.
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| 6. |
- Jansen, Willemijn J, et al.
(författare)
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Prevalence of cerebral amyloid pathology in persons without dementia: a meta-analysis.
- 2015
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Ingår i: JAMA. - : American Medical Association (AMA). - 1538-3598 .- 0098-7484. ; 313:19, s. 1924-38
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Tidskriftsartikel (refereegranskat)abstract
- Cerebral amyloid-β aggregation is an early pathological event in Alzheimer disease (AD), starting decades before dementia onset. Estimates of the prevalence of amyloid pathology in persons without dementia are needed to understand the development of AD and to design prevention studies.
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| 7. |
- Kadir, Ahmadul, et al.
(författare)
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Effect of phenserine treatment on brain functional activity and amyloid in Alzheimer's disease.
- 2008
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Ingår i: Annals of neurology. - : Wiley. - 1531-8249 .- 0364-5134. ; 63:5, s. 621-31
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The effects of (-)-phenserine (phenserine) and placebo/donepezil treatment on regional cerebral metabolic rate for glucose (rCMRglc) and brain amyloid load were investigated by positron emission tomography in 20 patients with mild Alzheimer's disease in relation to cerebrospinal fluid (CSF) and plasma biomarkers, and cognitive function. METHODS: The first 3 months of the study was a randomized, double-blind, placebo-controlled phase, during which 10 patients received phenserine (30 mg/day) and 10 patients the placebo. Three to 6 months was an open-label extension phase, during which the placebo group received donepezil (5 mg/day) and the phenserine group remained on phenserine. After 6 months, all patients received phenserine treatment up to 12 months. The patients underwent positron emission tomography examinations to measure rCMRglc (8F-FDG) and amyloid load (11C-PIB) at baseline and after 3 and 6 months of the treatment. Neuropsychological and biomarker data were collected at the three times of positron emission tomography imaging. RESULTS: Statistically significant effects on a composite neuropsychological test score were observed in the phenserine-treated group compared with the placebo and donepezil group at 3 and 6 months, respectively. Values of rCMRglc were significantly increased in several cortical regions after 3 months of phenserine treatment, compared with baseline, and correlated positively with cognitive function and CSF beta-amyloid 40 (Abeta40). Cortical Pittsburgh Compound B retention correlated negatively with CSF Abeta40 levels and the ratio Abeta/beta-secretase-cleaved amyloid precursor protein. In CSF, Abeta40 correlated positively with the attention domain of cognition. INTERPRETATION: Phenserine treatment was associated with an improvement in cognition and an increase in rCMRglc.
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| 8. |
- Leuzy, Antoine, et al.
(författare)
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Pittsburgh compound B imaging and cerebrospinal fluid amyloid-β in a multicentre European memory clinic study.
- 2016
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Ingår i: Brain : a journal of neurology. - : Oxford University Press (OUP). - 1460-2156. ; 139:Pt 9, s. 2540-53
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to assess the agreement between data on cerebral amyloidosis, derived using Pittsburgh compound B positron emission tomography and (i) multi-laboratory INNOTEST enzyme linked immunosorbent assay derived cerebrospinal fluid concentrations of amyloid-β42; (ii) centrally measured cerebrospinal fluid amyloid-β42 using a Meso Scale Discovery enzyme linked immunosorbent assay; and (iii) cerebrospinal fluid amyloid-β42 centrally measured using an antibody-independent mass spectrometry-based reference method. Moreover, we examined the hypothesis that discordance between amyloid biomarker measurements may be due to interindividual differences in total amyloid-β production, by using the ratio of amyloid-β42 to amyloid-β40 Our study population consisted of 243 subjects from seven centres belonging to the Biomarkers for Alzheimer's and Parkinson's Disease Initiative, and included subjects with normal cognition and patients with mild cognitive impairment, Alzheimer's disease dementia, frontotemporal dementia, and vascular dementia. All had Pittsburgh compound B positron emission tomography data, cerebrospinal fluid INNOTEST amyloid-β42 values, and cerebrospinal fluid samples available for reanalysis. Cerebrospinal fluid samples were reanalysed (amyloid-β42 and amyloid-β40) using Meso Scale Discovery electrochemiluminescence enzyme linked immunosorbent assay technology, and a novel, antibody-independent, mass spectrometry reference method. Pittsburgh compound B standardized uptake value ratio results were scaled using the Centiloid method. Concordance between Meso Scale Discovery/mass spectrometry reference measurement procedure findings and Pittsburgh compound B was high in subjects with mild cognitive impairment and Alzheimer's disease, while more variable results were observed for cognitively normal and non-Alzheimer's disease groups. Agreement between Pittsburgh compound B classification and Meso Scale Discovery/mass spectrometry reference measurement procedure findings was further improved when using amyloid-β42/40 Agreement between Pittsburgh compound B visual ratings and Centiloids was near complete. Despite improved agreement between Pittsburgh compound B and centrally analysed cerebrospinal fluid, a minority of subjects showed discordant findings. While future studies are needed, our results suggest that amyloid biomarker results may not be interchangeable in some individuals.
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| 9. |
- Mustafiz, Tamanna, et al.
(författare)
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Characterization of the brain β-amyloid isoform pattern at different ages of Tg2576 mice.
- 2011
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Ingår i: Neuro-degenerative diseases. - : S. Karger AG. - 1660-2862 .- 1660-2854. ; 8:5, s. 352-63
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Tidskriftsartikel (refereegranskat)abstract
- Although genetic and biochemical studies have suggested a cardinal role for β-amyloid (Aβ) in Alzheimer's disease, the underlying mechanism(s) of how Aβ induces neurodegeneration is still unclear. Our objective was to investigate the consequences of Aβ, especially on tau phosphorylation at specific epitopes important for Alzheimer's disease.
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| 10. |
- Simonsen, Anja Hviid, et al.
(författare)
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Recommendations for CSF AD biomarkers in the diagnostic evaluationof dementia.
- 2017
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Ingår i: Alzheimer's & dementia : the journal of the Alzheimer's Association. - : Wiley. - 1552-5279. ; 13:3, s. 274-284
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Tidskriftsartikel (refereegranskat)abstract
- This article presents recommendations, based on the Grading of Recommendations, Assessment, Development, and Evaluation method, for the clinical application of cerebrospinal fluid (CSF) amyloid-β1-42, tau, and phosphorylated tau in the diagnostic evaluation of patients with dementia. The recommendations were developed by a multidisciplinary working group based on the available evidence and consensus from focused discussions for (i) identification of Alzheimer's disease (AD) as the cause of dementia, (ii) prediction of rate of decline, (iii) cost-effectiveness, and (iv) interpretation of results. The working group found sufficient evidence to support a recommendation to use CSF AD biomarkers as a supplement to clinical evaluation, particularly in uncertain and atypical cases, to identify or exclude AD as the cause of dementia. Because of insufficient evidence, it was uncertain whether CSF AD biomarkers outperform imaging biomarkers. Operational recommendations for the interpretation of ambiguous CSF biomarker results were also provided.
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