scholarly journals Identifying Preclinical Alzheimer’s Disease Using Everyday Driving Behavior: Proof of Concept

2020 ◽  
pp. 1-6
Author(s):  
Ganesh M. Babulal ◽  
Ann Johnson ◽  
Anne M. Fagan ◽  
John C. Morris ◽  
Catherine M. Roe
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Driving Behavior ◽  
Amyloid Pet ◽  
Preclinical Alzheimer’S Disease ◽  
Neuropsychological Measures ◽  
Receiver Operating Characteristic Curves ◽  
Preclinical Ad ◽  
Positron Emission

We examined whether driving behavior can predict preclinical Alzheimer’s disease (AD). Data from 131 cognitively normal older adults with cerebrospinal fluid (CSF) and/or positron emission tomography (PET) biomarkers were examined with naturalistic driving behavior. Receiver operating characteristic curves were used to predict the highest 10%, 25%, and 50% of values for CSF tau/Aβ42, ptau181/Aβ42, or amyloid PET. Six in vivo driving variables alone yielded area under the curves (AUC) from 0.64–0.82. Addition of age, Apolipoprotein ɛ4, and neuropsychological measures to the models improved the AUC (0.81 to 0.90). Driving can be used as novel neurobehavioral marker to identify presence of preclinical AD.

scholarly journals Prospective longitudinal atrophy in Alzheimer’s disease correlates with the intensity and topography of baseline tau-PET

2020 ◽  
Vol 12 (524) ◽  
pp. eaau5732 ◽  
Author(s):  
Renaud La Joie ◽  
Adrienne V. Visani ◽  
Suzanne L. Baker ◽  
Jesse A. Brown ◽  
Viktoriya Bourakova ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Amyloid Pet ◽  
Specific Distribution ◽  
Positron Emission ◽  
Pet Radiotracers ◽  
Β Amyloid ◽  
Tau Pet ◽  
Prospective Longitudinal

β-Amyloid plaques and tau-containing neurofibrillary tangles are the two neuropathological hallmarks of Alzheimer’s disease (AD) and are thought to play crucial roles in a neurodegenerative cascade leading to dementia. Both lesions can now be visualized in vivo using positron emission tomography (PET) radiotracers, opening new opportunities to study disease mechanisms and improve patients’ diagnostic and prognostic evaluation. In a group of 32 patients at early symptomatic AD stages, we tested whether β-amyloid and tau-PET could predict subsequent brain atrophy measured using longitudinal magnetic resonance imaging acquired at the time of PET and 15 months later. Quantitative analyses showed that the global intensity of tau-PET, but not β-amyloid–PET, signal predicted the rate of subsequent atrophy, independent of baseline cortical thickness. Additional investigations demonstrated that the specific distribution of tau-PET signal was a strong indicator of the topography of future atrophy at the single patient level and that the relationship between baseline tau-PET and subsequent atrophy was particularly strong in younger patients. These data support disease models in which tau pathology is a major driver of local neurodegeneration and highlight the relevance of tau-PET as a precision medicine tool to help predict individual patient’s progression and design future clinical trials.

Amyloid imaging in Alzheimer’s disease: a potential new era of personalized medicine?

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Antoine Leuzy ◽  
Eduardo Zimmer ◽  
Serge Gauthier ◽  
Pedro Rosa-Neto
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Personalized Medicine ◽  
Amyloid Imaging ◽  
Phase Iii ◽  
Diagnostic Process ◽  
European Medicines Agency ◽  
Amyloid Pet ◽  
Positron Emission

AbstractRecent advances along clinical and neuropathological lines, as well as in our ability to detect the deposition of β-amyloid (Aβ) in vivo using positron emission tomography (PET), have helped redefine Alzheimer’s disease (AD) as a dynamic clinicobiological entity. On the basis of these advances, AD is now conceptualized as a continuum comprising asymptomatic, minimally symptomatic, and dementia phases, with detection of brain Aβ — in particular, via PET amyloid imaging — central to the diagnostic process. In this respect, [18F]florbetapir (Amyvid™) and [18F]flutemetamol (Vizamyl™) have recently received approval for clinical use from the Food and Drug Administration (FDA) and the European Medicines Agency (EMA), with additional radiofluorinated tracers for detection of Aβ in phase III trials. Recent initiatives such as the Alzheimer’s Disease Neuroimaging Initiative (ADNI) suggest that Aβ production, oligomerization and aggregation begins many years, possibly decades, before detectable cognitive impairment, with Aβ shown to associate with cognitive decline and conversion to dementia. While personalized medicine has now emerged as a prospect for the field, the recent decision by the Centers for Medicare & Medicaid Services (CMS) — who declined to cover the cost of amyloid PET imaging citing insufficient evidence to support its clinical utility — highlights that such a move may be premature.

Cohort-Specific Optimization of Models Predicting Preclinical Alzheimer’s Disease, to Enhance Screening Performance in the Middle of Preclinical Alzheimer’s Disease Clinical Studies

2021 ◽  
pp. 1-10
Author(s):  
K. Sato ◽  
T. Mano ◽  
R. Ihara ◽  
K. Suzuki ◽  
Y. Niimi ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Sex Education ◽  
Apoe Genotype ◽  
Standardized Uptake Value ◽  
Asian Population ◽  
Amyloid Pet ◽  
Preclinical Alzheimer’S Disease ◽  
Clinical Dementia Rating ◽  
Preclinical Ad

BACKGROUND: Models that can predict brain amyloid beta (Aβ) status more accurately have been desired to identify participants for clinical trials of preclinical Alzheimer’s disease (AD). However, potential heterogeneity between different cohorts and the limited cohort size have been the reasons preventing the development of reliable models applicable to the Asian population, including Japan. Objectives: We aim to propose a novel approach to predict preclinical AD while overcoming these constraints, by building models specifically optimized for ADNI or for J-ADNI, based on the larger samples from A4 study data. Design & Participants: This is a retrospective study including cognitive normal participants (CDR-global = 0) from A4 study, Alzheimer Disease Neuroimaging Initiative (ADNI), and Japanese-ADNI (J-ADNI) cohorts. Measurements: The model is made up of age, sex, education years, history of AD, Clinical Dementia Rating-Sum of Boxes, Preclinical Alzheimer Cognitive Composite score, and APOE genotype, to predict the degree of amyloid accumulation in amyloid PET as Standardized Uptake Value ratio (SUVr). The model was at first built based on A4 data, and we can choose at which SUVr threshold configuration the A4-based model may achieve the best performance area under the curve (AUC) when applied to the random-split half ADNI or J-ADNI subset. We then evaluated whether the selected model may also achieve better performance in the remaining ADNI or J-ADNI subsets. Result: When compared to the results without optimization, this procedure showed efficacy of AUC improvement of up to approximately 0.10 when applied to the models “without APOE;” the degree of AUC improvement was larger in the ADNI cohort than in the J-ADNI cohort. Conclusions: The obtained AUC had improved mildly when compared to the AUC in case of literature-based predetermined SUVr threshold configuration. This means our procedure allowed us to predict preclinical AD among ADNI or J-ADNI second-half samples with slightly better predictive performance. Our optimizing method may be practically useful in the middle of the ongoing clinical study of preclinical AD, as a screening to further increase the prior probability of preclinical AD before amyloid testing.

scholarly journals The Value of OCT and OCTA as Potential Biomarkers for Preclinical Alzheimer’s Disease: A Review Study

Life ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 712
Author(s):  
Inés López-Cuenca ◽  
Elena Salobrar-García ◽  
Lorena Elvira-Hurtado ◽  
José A. Fernández-Albarral ◽  
Lidia Sánchez-Puebla ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Longitudinal Studies ◽  
Positron Emission Tomography Imaging ◽  
Cost Effective ◽  
Therapeutic Interventions ◽  
Preclinical Alzheimer’S Disease ◽  
Cerebral Amyloidosis ◽  
Preclinical Ad ◽  
Positron Emission

Preclinical Alzheimer’s disease (AD) includes cognitively healthy subjects with at least one positive biomarker: reduction in cerebrospinal fluid Aβ42 or visualization of cerebral amyloidosis by positron emission tomography imaging. The use of these biomarkers is expensive, invasive, and not always possible. It has been shown that the retinal changes measured by optical coherence tomography (OCT) and OCT-angiography (OCTA) could be biomarkers of AD. Diagnosis in early stages before irreversible AD neurological damage takes place is important for the development of new therapeutic interventions. In this review, we summarize the findings of different published studies using OCT and OCTA in participants with preclinical AD. To date, there have been few studies on this topic and they are methodologically very dissimilar. Moreover, these include only two longitudinal studies. For these reasons, it would be interesting to unify the methodology, make the inclusion criteria more rigorous, and conduct longer longitudinal studies to assess the evolution of these subjects. If the results were consistent across repeated studies with the same methodology, this could provide us with insight into the value of the retinal changes observed by OCT/OCTA as potential reliable, cost-effective, and noninvasive biomarkers of preclinical AD.

scholarly journals Multimorbidity Is Associated with Preclinical Alzheimer’s Disease Neuroimaging Biomarkers

2018 ◽  
Vol 45 (5-6) ◽  
pp. 272-281 ◽  
Author(s):  
Aline Mendes ◽  
Sophie Tezenas du Montcel ◽  
Marcel Levy ◽  
Anne Bertrand ◽  
Marie-Odile Habert ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Positron Emission Tomography ◽  
Fdg Pet ◽  
Emission Tomography ◽  
Amyloid Pet ◽  
Preclinical Alzheimer’S Disease ◽  
Positron Emission ◽  
Obstructive Sleep ◽  
Neuroimaging Biomarkers

Background: Identifying comorbidities that influence preclinical Alzheimer’s disease (AD) can give some insight into the AD early stages trajectories to allow new treatment venues and to guide public health systems to prevent subsequent dementia. Objective: To examine the association of multimorbidity with AD neuroimaging markers in cognitively normal older adults. Methods: This study had a cross-sectional design. Data regarding 14 comorbidities were obtained for all 318 adults aged 70–85 years, recruited from the community to an ongoing prospective monocentric cohort. They underwent standardized neuropsychological and neuroimaging assessment with automated methods that measured hippocampal volumes, white matter hyperintensity volumes, fluorodeoxyglucose positron emission tomography (FDG-PET) standardized uptake values (SUV) in AD signature regions, and amyloid positron emission tomography (amyloid-PET) SUV ratios. Linear regression was used to assess the association of multimorbidity with AD neuroimaging biomarkers. Results: Multimorbidity is signif icantly associated with lower hippocampal volumes (–0.03 ± 0.01; p = 0.012; R2 = 0.017) and lower FDG-PET SUV (–0.027 ± 0.009; p = 0.005; R2 = 0.022), with no association with amyloid deposition (0.001 ± 0.007; p = 0.884; R2 = 0.0001). Taken individually, obesity and excessive alcohol use are associated with lower FDG-PET values, whereas obstructive sleep apnea and mood disorders are related to lower amyloid-PET SUV ratios. Conclusion: Multimorbidity is associated with preclinical AD imaging markers of neurodegeneration, but not with amyloid.

scholarly journals Patterns of Cortical and Subcortical Amyloid Burden across Stages of Preclinical Alzheimer’s Disease

2016 ◽  
Vol 22 (10) ◽  
pp. 978-990 ◽  
Author(s):  
Emily C. Edmonds ◽  
Katherine J. Bangen ◽  
Lisa Delano-Wood ◽  
Daniel A. Nation ◽  
Ansgar J. Furst ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Standardized Uptake Value ◽  
Imaging Biomarkers ◽  
Preclinical Alzheimer’S Disease ◽  
Preclinical Ad ◽  
Novel Approach ◽  
Positron Emission ◽  
Subcortical Regions ◽  
Cortical Regions

AbstractObjectives: We examined florbetapir positron emission tomography (PET) amyloid scans across stages of preclinical Alzheimer’s disease (AD) in cortical, allocortical, and subcortical regions. Stages were characterized using empirically defined methods. Methods: A total of 312 cognitively normal Alzheimer’s Disease Neuroimaging Initiative participants completed a neuropsychological assessment and florbetapir PET scan. Participants were classified into stages of preclinical AD using (1) a novel approach based on the number of abnormal biomarkers/cognitive markers each individual possessed, and (2) National Institute on Aging and the Alzheimer’s Association (NIA-AA) criteria. Preclinical AD groups were compared to one another and to a mild cognitive impairment (MCI) sample on florbetapir standardized uptake value ratios (SUVRs) in cortical and allocortical/subcortical regions of interest (ROIs). Results: Amyloid deposition increased across stages of preclinical AD in all cortical ROIs, with SUVRs in the later stages reaching levels seen in MCI. Several subcortical areas showed a pattern of results similar to the cortical regions; however, SUVRs in the hippocampus, pallidum, and thalamus largely did not differ across stages of preclinical AD. Conclusions: Substantial amyloid accumulation in cortical areas has already occurred before one meets criteria for a clinical diagnosis. Potential explanations for the unexpected pattern of results in some allocortical/subcortical ROIs include lack of correspondence between (1) cerebrospinal fluid and florbetapir PET measures of amyloid, or between (2) subcortical florbetapir PET SUVRs and underlying neuropathology. Findings support the utility of our novel method for staging preclinical AD. By combining imaging biomarkers with detailed cognitive assessment to better characterize preclinical AD, we can advance our understanding of who is at risk for future progression. (JINS, 2016, 22, 978–990)

scholarly journals THE ROLE OF CLINICAL TRIALS IN PRECLINICAL ALZHEIMER’S DISEASE DRUG DEVELOPMENT PROGRAMS

2020 ◽  
pp. 1-3
Author(s):  
J. Cummings
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Clinical Trials ◽  
Cognitive Impairment ◽  
Functional Impairment ◽  
Amyloid Beta Protein ◽  
Neuropsychological Measures ◽  
Preclinical Phase ◽  
Preclinical Ad ◽  
Positron Emission

Alzheimer’s disease (AD) has a 15-20 year preclinical phase during which the individuals have normal cognition by conventional measures and have state measures of AD pathology including elevated levels of brain amyloid when assessed with positron emission tomography (PET) and abnormally decreased levels cerebrospinal fluid (CSF) amyloid beta-protein (Aß) and increased levels of total tau and hyperphosphorylated tau (p-tau) (1, 2). Recognition of this long-preclinical phase and the presence of biomarker changes affords, the opportunity to plan secondary prevention trials to prevent or delay the onset of cognitive impairment and progression to dementia. The US Food and Drug Administration (FDA) facilitated planning of clinical trials for participants in the preclinical phase of AD by defining two stages of the preclinical period: in stage 1 participants have characteristic pathophysiologic changes of AD but no evidence of clinical impact; in stage 2 participants have characteristic pathophysiologic changes of AD and subtle detectable abnormalities on sensitive neuropsychological measures, but no functional impairment. Stage 3 participants are no longer in the preclinical phase of AD; they have mild cognitive impairment (MCI)/prodromal AD with characteristic pathophysiologic changes of AD, subtle or more apparent detectable abnormalities on sensitive neuropsychological measures, and mild but detectable functional impairment. Stages 4, 5, and 6 describe patients with mild, moderate and severe AD dementia. Biomarker, clinical definitions, and regulatory engagement have set the stage for planning and conduct of trials in preclinical AD.

scholarly journals Disease progression modelling from preclinical Alzheimer’s disease (AD) to AD dementia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Soo Hyun Cho ◽  
Sookyoung Woo ◽  
Changsoo Kim ◽  
Hee Jin Kim ◽  
Hyemin Jang ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Disease Progression ◽  
Disease Assessment ◽  
Time Interval ◽  
Disease Course ◽  
Preclinical Alzheimer’S Disease ◽  
Apoe Ε4 ◽  
Preclinical Ad ◽  
Cognitive Subscale

AbstractTo characterize the course of Alzheimer’s disease (AD) over a longer time interval, we aimed to construct a disease course model for the entire span of the disease using two separate cohorts ranging from preclinical AD to AD dementia. We modelled the progression course of 436 patients with AD continuum and investigated the effects of apolipoprotein E ε4 (APOE ε4) and sex on disease progression. To develop a model of progression from preclinical AD to AD dementia, we estimated Alzheimer’s Disease Assessment Scale-Cognitive Subscale 13 (ADAS-cog 13) scores. When calculated as the median of ADAS-cog 13 scores for each cohort, the estimated time from preclinical AD to MCI due to AD was 7.8 years and preclinical AD to AD dementia was 15.2 years. ADAS-cog 13 scores deteriorated most rapidly in women APOE ε4 carriers and most slowly in men APOE ε4 non-carriers (p < 0.001). Our results suggest that disease progression modelling from preclinical AD to AD dementia may help clinicians to estimate where patients are in the disease course and provide information on variation in the disease course by sex and APOE ε4 status.

scholarly journals Cognitive Performance and Cerebrospinal Fluid Markers in Preclinical Alzheimer’s Disease: Results from the Gothenburg H70 Birth Cohort Studies

2021 ◽  
Vol 79 (1) ◽  
pp. 225-235
Author(s):  
Maya Arvidsson Rådestig ◽  
Johan Skoog ◽  
Henrik Zetterberg ◽  
Jürgen Kern ◽  
Anna Zettergren ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cerebrospinal Fluid ◽  
Cohort Studies ◽  
Cognitive Performance ◽  
Birth Cohort ◽  
Population Based ◽  
Tau Pathology ◽  
Preclinical Alzheimer’S Disease ◽  
Preclinical Ad

Background: We have previously shown that older adults with preclinical Alzheimer’s disease (AD) pathology in cerebrospinal fluid (CSF) had slightly worse performance in Mini-Mental State Examination (MMSE) than participants without preclinical AD pathology. Objective: We therefore aimed to compare performance on neurocognitive tests in a population-based sample of 70-year-olds with and without CSF AD pathology. Methods: The sample was derived from the population-based Gothenburg H70 Birth Cohort Studies in Sweden. Participants (n = 316, 70 years old) underwent comprehensive cognitive examinations, and CSF Aβ-42, Aβ-40, T-tau, and P-tau concentrations were measured. Participants were classified according to the ATN system, and according to their Clinical Dementia Rating (CDR) score. Cognitive performance was examined in the CSF amyloid, tau, and neurodegeneration (ATN) categories. Results: Among participants with CDR 0 (n = 259), those with amyloid (A+) and/or tau pathology (T+, N+) showed similar performance on most cognitive tests compared to participants with A-T-N-. Participants with A-T-N+ performed worse in memory (Supra span (p = 0.003), object Delayed (p = 0.042) and Immediate recall (p = 0.033)). Among participants with CDR 0.5 (n = 57), those with amyloid pathology (A+) scored worse in category fluency (p = 0.003). Conclusion: Cognitively normal participants with amyloid and/or tau pathology performed similarly to those without any biomarker evidence of preclinical AD in most cognitive domains, with the exception of slightly poorer memory performance in A-T-N+. Our study suggests that preclinical AD biomarkers are altered before cognitive decline.

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