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1.
Neurology ; 102(6): e208053, 2024 Mar 26.
Article in English | MEDLINE | ID: mdl-38377442

ABSTRACT

OBJECTIVES: Higher-educated patients with Alzheimer disease (AD) can harbor greater neuropathologic burden than those with less education despite similar symptom severity. In this study, we assessed whether this observation is also present in potential preclinical AD stages, namely in individuals with subjective cognitive decline and clinical features increasing AD likelihood (SCD+). METHODS: Amyloid-PET information ([18F]Flutemetamol or [18F]Florbetaben) of individuals with SCD+, mild cognitive impairment (MCI), and AD were retrieved from the AMYPAD-DPMS cohort, a multicenter randomized controlled study. Group classification was based on the recommendations by the SCD-I and NIA-AA working groups. Amyloid PET images were acquired within 8 months after initial screening and processed with AMYPYPE. Amyloid load was based on global Centiloid (CL) values. Educational level was indexed by formal schooling and subsequent higher education in years. Using linear regression analysis, the main effect of education on CL values was tested across the entire cohort, followed by the assessment of an education-by-diagnostic-group interaction (covariates: age, sex, and recruiting memory clinic). To account for influences of non-AD pathology and comorbidities concerning the tested amyloid-education association, we compared white matter hyperintensity (WMH) severity, cardiovascular events, depression, and anxiety history between lower-educated and higher-educated groups within each diagnostic category using the Fisher exact test or χ2 test. Education groups were defined using a median split on education (Md = 13 years) in a subsample of the initial cohort, for whom this information was available. RESULTS: Across the cohort of 212 individuals with SCD+ (M(Age) = 69.17 years, F 42.45%), 258 individuals with MCI (M(Age) = 72.93, F 43.80%), and 195 individuals with dementia (M(Age) = 74.07, F 48.72%), no main effect of education (ß = 0.52, 95% CI -0.30 to 1.58), but a significant education-by-group interaction on CL values, was found (p = 0.024) using linear regression modeling. This interaction was driven by a negative association of education and CL values in the SCD+ group (ß = -0.11, 95% CI -4.85 to -0.21) and a positive association in the MCI group (ß = 0.15, 95% CI 0.79-5.22). No education-dependent differences in terms of WMH severity and comorbidities were found in the subsample (100 cases with SCD+, 97 cases with MCI, 72 cases with dementia). DISCUSSION: Education may represent a factor oppositely modulating subjective awareness in preclinical stages and objective severity of ongoing neuropathologic processes in clinical stages.


Subject(s)
Alzheimer Disease , Cognitive Dysfunction , Aged , Female , Humans , Male , Alzheimer Disease/diagnostic imaging , Alzheimer Disease/epidemiology , Amyloid , Amyloid beta-Peptides , Amyloidogenic Proteins , Biomarkers , Cognitive Dysfunction/diagnostic imaging , Cognitive Dysfunction/epidemiology , Educational Status , Longitudinal Studies , Positron-Emission Tomography , Multicenter Studies as Topic , Randomized Controlled Trials as Topic
2.
Conscious Cogn ; 116: 103603, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37976783

ABSTRACT

The possibility of flexibly retrieving our memories using a first-person or a third-person perspective (1PP or 3PP) has been extensively investigated in episodic memory research. Here, we used a Virtual Reality-based paradigm to manipulate the visual perspective used during the encoding stage to investigate age-related differences in the formation of memories experienced from 1PP vs. 3PP. 32 young adults and 32 seniors participated in the study. Participants navigated through two virtual cities to encode complex real-life virtual events, from either a 1PP (as if from their egocentric viewpoint) or a 3PP, while actively controlling an avatar. While recognition accuracy was higher in young adults after encoding in 1PP compared to 3PP, there was no benefit in memory formation in 1PP for older adults. These findings are discussed in terms of both age-related changes in episodic memory functioning and self-referencing processes.


Subject(s)
Memory, Episodic , Virtual Reality , Young Adult , Humans , Aged , Reaction Time , Aging , Recognition, Psychology
3.
JAMA Neurol ; 80(6): 548-557, 2023 06 01.
Article in English | MEDLINE | ID: mdl-37155177

ABSTRACT

Importance: Amyloid positron emission tomography (PET) allows the direct assessment of amyloid deposition, one of the main hallmarks of Alzheimer disease. However, this technique is currently not widely reimbursed because of the lack of appropriately designed studies demonstrating its clinical effect. Objective: To assess the clinical effect of amyloid PET in memory clinic patients. Design, Setting, and Participants: The AMYPAD-DPMS is a prospective randomized clinical trial in 8 European memory clinics. Participants were allocated (using a minimization method) to 3 study groups based on the performance of amyloid PET: arm 1, early in the diagnostic workup (within 1 month); arm 2, late in the diagnostic workup (after a mean [SD] 8 [2] months); or arm 3, if and when the managing physician chose. Participants were patients with subjective cognitive decline plus (SCD+; SCD plus clinical features increasing the likelihood of preclinical Alzheimer disease), mild cognitive impairment (MCI), or dementia; they were assessed at baseline and after 3 months. Recruitment took place between April 16, 2018, and October 30, 2020. Data analysis was performed from July 2022 to January 2023. Intervention: Amyloid PET. Main Outcome and Measure: The main outcome was the difference between arm 1 and arm 2 in the proportion of participants receiving an etiological diagnosis with a very high confidence (ie, ≥90% on a 50%-100% visual numeric scale) after 3 months. Results: A total of 844 participants were screened, and 840 were enrolled (291 in arm 1, 271 in arm 2, 278 in arm 3). Baseline and 3-month visit data were available for 272 participants in arm 1 and 260 in arm 2 (median [IQR] age: 71 [65-77] and 71 [65-77] years; 150/272 male [55%] and 135/260 male [52%]; 122/272 female [45%] and 125/260 female [48%]; median [IQR] education: 12 [10-15] and 13 [10-16] years, respectively). After 3 months, 109 of 272 participants (40%) in arm 1 had a diagnosis with very high confidence vs 30 of 260 (11%) in arm 2 (P < .001). This was consistent across cognitive stages (SCD+: 25/84 [30%] vs 5/78 [6%]; P < .001; MCI: 45/108 [42%] vs 9/102 [9%]; P < .001; dementia: 39/80 [49%] vs 16/80 [20%]; P < .001). Conclusion and Relevance: In this study, early amyloid PET allowed memory clinic patients to receive an etiological diagnosis with very high confidence after only 3 months compared with patients who had not undergone amyloid PET. These findings support the implementation of amyloid PET early in the diagnostic workup of memory clinic patients. Trial Registration: EudraCT Number: 2017-002527-21.


Subject(s)
Alzheimer Disease , Cognitive Dysfunction , Humans , Male , Female , Aged , Alzheimer Disease/psychology , Brain/metabolism , Prospective Studies , Positron-Emission Tomography , Amyloid/metabolism , Amyloidogenic Proteins , Amyloid beta-Peptides/metabolism
4.
Lancet Reg Health Eur ; 26: 100576, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36895446

ABSTRACT

Observational population studies indicate that prevention of dementia and cognitive decline is being accomplished, possibly as an unintended result of better vascular prevention and healthier lifestyles. Population aging in the coming decades requires deliberate efforts to further decrease its prevalence and societal burden. Increasing evidence supports the efficacy of preventive interventions on persons with intact cognition and high dementia risk. We report recommendations for the deployment of second-generation memory clinics (Brain Health Services) whose mission is evidence-based and ethical dementia prevention in at-risk individuals. The cornerstone interventions consist of (i) assessment of genetic and potentially modifiable risk factors including brain pathology, and risk stratification, (ii) risk communication with ad-hoc protocols, (iii) risk reduction with multi-domain interventions, and (iv) cognitive enhancement with cognitive and physical training. A roadmap is proposed for concept validation and ensuing clinical deployment.

5.
JAMA Netw Open ; 6(1): e2250921, 2023 01 03.
Article in English | MEDLINE | ID: mdl-36637820

ABSTRACT

Importance: Individuals who are amyloid-positive with subjective cognitive decline and clinical features increasing the likelihood of preclinical Alzheimer disease (SCD+) are at higher risk of developing dementia. Some individuals with SCD+ undergo amyloid-positron emission tomography (PET) as part of research studies and frequently wish to know their amyloid status; however, the disclosure of a positive amyloid-PET result might have psychological risks. Objective: To assess the psychological outcomes of the amyloid-PET result disclosure in individuals with SCD+ and explore which variables are associated with a safer disclosure in individuals who are amyloid positive. Design, Setting, and Participants: This prospective, multicenter study was conducted as part of The Amyloid Imaging to Prevent Alzheimer Disease Diagnostic and Patient Management Study (AMYPAD-DPMS) (recruitment period: from April 2018 to October 2020). The setting was 5 European memory clinics, and participants included patients with SCD+ who underwent amyloid-PET. Statistical analysis was performed from July to October 2022. Exposures: Disclosure of amyloid-PET result. Main Outcomes and Measures: Psychological outcomes were defined as (1) disclosure related distress, assessed using the Impact of Event Scale-Revised (IES-R; scores of at least 33 indicate probable presence of posttraumatic stress disorder [PTSD]); and (2) anxiety and depression, assessed using the Hospital Anxiety and Depression scale (HADS; scores of at least 15 indicate probable presence of severe mood disorder symptoms). Results: After disclosure, 27 patients with amyloid-positive SCD+ (median [IQR] age, 70 [66-74] years; gender: 14 men [52%]; median [IQR] education: 15 [13 to 17] years, median [IQR] Mini-Mental State Examination [MMSE] score, 29 [28 to 30]) had higher median (IQR) IES-R total score (10 [2 to 14] vs 0 [0 to 2]; P < .001), IES-R avoidance (0.00 [0.00 to 0.69] vs 0.00 [0.00 to 0.00]; P < .001), IES-R intrusions (0.50 [0.13 to 0.75] vs 0.00 [0.00 to 0.25]; P < .001), and IES-R hyperarousal (0.33 [0.00 to 0.67] vs 0.00 [0.00 to 0.00]; P < .001) scores than the 78 patients who were amyloid-negative (median [IQR], age, 67 [64 to 74] years, 45 men [58%], median [IQR] education: 15 [12 to 17] years, median [IQR] MMSE score: 29 [28 to 30]). There were no observed differences between amyloid-positive and amyloid-negative patients in the median (IQR) HADS Anxiety (-1.0 [-3.0 to 1.8] vs -2.0 [-4.8 to 1.0]; P = .06) and Depression (-1.0 [-2.0 to 0.0] vs -1.0 [-3.0 to 0.0]; P = .46) deltas (score after disclosure - scores at baseline). In patients with amyloid-positive SCD+, despite the small sample size, higher education was associated with lower disclosure-related distress (ρ = -0.43; P = .02) whereas the presence of study partner was associated with higher disclosure-related distress (W = 7.5; P = .03). No participants with amyloid-positive SCD+ showed probable presence of PTSD or severe anxiety or depression symptoms at follow-up. Conclusions and Relevance: The disclosure of a positive amyloid-PET result to patients with SCD+ was associated with a bigger psychological change, yet such change did not reach the threshold for clinical concern.


Subject(s)
Alzheimer Disease , Cognitive Dysfunction , Male , Humans , Adult , Aged , Alzheimer Disease/diagnosis , Brain/metabolism , Amyloid beta-Peptides/metabolism , Prospective Studies , Disclosure , Positron-Emission Tomography , Cognitive Dysfunction/diagnostic imaging
6.
Proc Natl Acad Sci U S A ; 119(35): e2202764119, 2022 08 30.
Article in English | MEDLINE | ID: mdl-35998220

ABSTRACT

The use of spoken and written language is a fundamental human capacity. Individual differences in reading- and language-related skills are influenced by genetic variation, with twin-based heritability estimates of 30 to 80% depending on the trait. The genetic architecture is complex, heterogeneous, and multifactorial, but investigations of contributions of single-nucleotide polymorphisms (SNPs) were thus far underpowered. We present a multicohort genome-wide association study (GWAS) of five traits assessed individually using psychometric measures (word reading, nonword reading, spelling, phoneme awareness, and nonword repetition) in samples of 13,633 to 33,959 participants aged 5 to 26 y. We identified genome-wide significant association with word reading (rs11208009, P = 1.098 × 10-8) at a locus that has not been associated with intelligence or educational attainment. All five reading-/language-related traits showed robust SNP heritability, accounting for 13 to 26% of trait variability. Genomic structural equation modeling revealed a shared genetic factor explaining most of the variation in word/nonword reading, spelling, and phoneme awareness, which only partially overlapped with genetic variation contributing to nonword repetition, intelligence, and educational attainment. A multivariate GWAS of word/nonword reading, spelling, and phoneme awareness maximized power for follow-up investigation. Genetic correlation analysis with neuroimaging traits identified an association with the surface area of the banks of the left superior temporal sulcus, a brain region linked to the processing of spoken and written language. Heritability was enriched for genomic elements regulating gene expression in the fetal brain and in chromosomal regions that are depleted of Neanderthal variants. Together, these results provide avenues for deciphering the biological underpinnings of uniquely human traits.


Subject(s)
Genome-Wide Association Study , Individuality , Reading , Speech , Adolescent , Adult , Child , Child, Preschool , Genetic Loci , Humans , Language , Polymorphism, Single Nucleotide , Young Adult
7.
Alzheimers Dement ; 2022 Jun 17.
Article in English | MEDLINE | ID: mdl-35715930

ABSTRACT

INTRODUCTION: AMYPAD Diagnostic and Patient Management Study (DPMS) aims to investigate the clinical utility and cost-effectiveness of amyloid-PET in Europe. Here we present participants' baseline features and discuss the representativeness of the cohort. METHODS: Participants with subjective cognitive decline plus (SCD+), mild cognitive impairment (MCI), or dementia were recruited in eight European memory clinics from April 16, 2018, to October 30, 2020, and randomized into three arms: ARM1, early amyloid-PET; ARM2, late amyloid-PET; and ARM3, free-choice. RESULTS: A total of 840 participants (244 SCD+, 341 MCI, and 255 dementia) were enrolled. Sociodemographic/clinical features did not differ significantly among recruiting memory clinics or with previously reported cohorts. The randomization assigned 35% of participants to ARM1, 32% to ARM2, and 33% to ARM3; cognitive stages were distributed equally across the arms. DISCUSSION: The features of AMYPAD-DPMS participants are as expected for a memory clinic population. This ensures the generalizability of future study results.

9.
Alzheimers Dement ; 18(1): 29-42, 2022 01.
Article in English | MEDLINE | ID: mdl-33984176

ABSTRACT

INTRODUCTION: Harmonized neuropsychological assessment for neurocognitive disorders, an international priority for valid and reliable diagnostic procedures, has been achieved only in specific countries or research contexts. METHODS: To harmonize the assessment of mild cognitive impairment in Europe, a workshop (Geneva, May 2018) convened stakeholders, methodologists, academic, and non-academic clinicians and experts from European, US, and Australian harmonization initiatives. RESULTS: With formal presentations and thematic working-groups we defined a standard battery consistent with the U.S. Uniform DataSet, version 3, and homogeneous methodology to obtain consistent normative data across tests and languages. Adaptations consist of including two tests specific to typical Alzheimer's disease and behavioral variant frontotemporal dementia. The methodology for harmonized normative data includes consensus definition of cognitively normal controls, classification of confounding factors (age, sex, and education), and calculation of minimum sample sizes. DISCUSSION: This expert consensus allows harmonizing the diagnosis of neurocognitive disorders across European countries and possibly beyond.


Subject(s)
Cognitive Dysfunction , Consensus Development Conferences as Topic , Datasets as Topic/standards , Neuropsychological Tests/standards , Age Factors , Cognition , Cognitive Dysfunction/classification , Cognitive Dysfunction/diagnosis , Educational Status , Europe , Expert Testimony , Humans , Language , Sex Factors
10.
Rev Med Suisse ; 17(763): 2202-2205, 2021 Dec 15.
Article in French | MEDLINE | ID: mdl-34910407

ABSTRACT

The Memory Centres of several Swiss hospitals have set up a national online registry for Alzheimer's research, called www.BHR-suisse.org. This type of registry already exists in the United States (www.brainhealthregistry.org/) and the Netherlands (https://hersenonderzoek.nl/). It contributes, as do these initiating sites, to the creation of a global database of research partnersb who wish to contribute by participating in studies on neurodegenerative diseases and more particularly on Alzheimer's disease. By registering, they provide a certain amount of information and become potential research partners. Researchers can then select a panel of volunteers according to the selection and exclusion criteria of their studies, contact them and include them in their studies.


Les centres de la mémoire de plusieurs hôpitaux suisses ont créé un Registre national suisse en ligne pour la recherche sur Alzheimer, intitulé www.bhr-suisse.org. Ce type de registre existe déjà aux États-Unis (www.brainhealthregistry.org/) et aux Pays-Bas (hersenonderzoek.nl/). Il contribue, au même titre que ces sites initiateurs, à constituer une base de données globale de partenaires de recherchea qui souhaitent apporter leur contribution en participant à des études sur les maladies neurodégénératives et, plus particulièrement, sur la maladie d'Alzheimer. En s'inscrivant, ces derniers apportent un certain nombre d'informations et deviennent de potentiels partenaires de recherche. Les chercheurs peuvent ensuite sélectionner un panel suivant les critères de sélection et d'exclusion de leurs études, contacter les volontaires et les intégrer dans ces études.


Subject(s)
Alzheimer Disease , Alzheimer Disease/epidemiology , Alzheimer Disease/therapy , Brain , Humans , Netherlands , Registries , Switzerland/epidemiology , United States
11.
Alzheimers Res Ther ; 13(1): 172, 2021 10 11.
Article in English | MEDLINE | ID: mdl-34635149

ABSTRACT

Cognitive complaints in the absence of objective cognitive impairment, observed in patients with subjective cognitive decline (SCD), are common in old age. The first step to postpone cognitive decline is to use techniques known to improve cognition, i.e., cognitive enhancement techniques.We aimed to provide clinical recommendations to improve cognitive performance in cognitively unimpaired individuals, by using cognitive, mental, or physical training (CMPT), non-invasive brain stimulations (NIBS), drugs, or nutrients. We made a systematic review of CMPT studies based on the GRADE method rating the strength of evidence.CMPT have clinically relevant effects on cognitive and non-cognitive outcomes. The quality of evidence supporting the improvement of outcomes following a CMPT was high for metamemory; moderate for executive functions, attention, global cognition, and generalization in daily life; and low for objective memory, subjective memory, motivation, mood, and quality of life, as well as a transfer to other cognitive functions. Regarding specific interventions, CMPT based on repeated practice (e.g., video games or mindfulness, but not physical training) improved attention and executive functions significantly, while CMPT based on strategic learning significantly improved objective memory.We found encouraging evidence supporting the potential effect of NIBS in improving memory performance, and reducing the perception of self-perceived memory decline in SCD. Yet, the high heterogeneity of stimulation protocols in the different studies prevent the issuing of clear-cut recommendations for implementation in a clinical setting. No conclusive argument was found to recommend any of the main pharmacological cognitive enhancement drugs ("smart drugs", acetylcholinesterase inhibitors, memantine, antidepressant) or herbal extracts (Panax ginseng, Gingko biloba, and Bacopa monnieri) in people without cognitive impairment.Altogether, this systematic review provides evidence for CMPT to improve cognition, encouraging results for NIBS although more studies are needed, while it does not support the use of drugs or nutrients.


Subject(s)
Cognitive Dysfunction , Quality of Life , Acetylcholinesterase , Brain , Clinical Protocols , Cognition , Health Services , Humans , Systematic Reviews as Topic
12.
Alzheimers Res Ther ; 13(1): 168, 2021 10 11.
Article in English | MEDLINE | ID: mdl-34635163

ABSTRACT

Dementia has a devastating impact on the quality of life of patients and families and comes with a huge cost to society. Dementia prevention is considered a public health priority by the World Health Organization. Delaying the onset of dementia by treating associated risk factors will bring huge individual and societal benefit. Empirical evidence suggests that, in higher-income countries, dementia incidence is decreasing as a result of healthier lifestyles. This observation supports the notion that preventing dementia is possible and that a certain degree of prevention is already in action. Further reduction of dementia incidence through deliberate prevention plans is needed to counteract its growing prevalence due to increasing life expectancy.An increasing number of individuals with normal cognitive performance seek help in the current memory clinics asking an evaluation of their dementia risk, preventive interventions, or interventions to ameliorate their cognitive performance. Consistent evidence suggests that some of these individuals are indeed at increased risk of dementia. This new health demand asks for a shift of target population, from patients with cognitive impairment to worried but cognitively unimpaired individuals. However, current memory clinics do not have the programs and protocols in place to deal with this new population.We envision the development of new services, henceforth called Brain Health Services, devoted to respond to demands from cognitively unimpaired individuals concerned about their risk of dementia. The missions of Brain Health Services will be (i) dementia risk profiling, (ii) dementia risk communication, (iii) dementia risk reduction, and (iv) cognitive enhancement. In this paper, we present the organizational and structural challenges associated with the set-up of Brain Health Services.


Subject(s)
Cognitive Dysfunction , Quality of Life , Brain , Cognition , Health Services , Humans
13.
Neuroimage Clin ; 32: 102799, 2021.
Article in English | MEDLINE | ID: mdl-34469849

ABSTRACT

There is evidence that gray matter networks are disrupted in Mild Cognitive Impairment (MCI) and associated with cognitive impairment and faster disease progression. However, it remains unknown how these alterations are related to the presence of Apolipoprotein E isoform E4 (ApoE4), the most prominent genetic risk factor for late-onset Alzheimer's disease (AD). To investigate this topic at the individual level, we explore the impact of ApoE4 and the disease progression on the Single-Subject Gray Matter Networks (SSGMNets) using the graph theory approach. Our data sample comprised 200 MCI patients selected from the ADNI database, classified as non-Converters and Converters (will progress into AD). Each group included 50 ApoE4-positive ('Carriers', ApoE4 + ) and 50 ApoE4-negative ('non-Carriers', ApoE4-). The SSGMNets were estimated from structural MRIs at two-time points: baseline and conversion. We investigated whether altered network topological measures at baseline and their rate of change (RoC) between baseline and conversion time points were associated with ApoE4 and disease progression. We also explored the correlation of SSGMNets attributes with general cognition score (MMSE), memory (ADNI-MEM), and CSF-derived biomarkers of AD (Aß42, T-tau, and P-tau). Our results showed that ApoE4 and the disease progression modulated the global topological network properties independently but not in their RoC. MCI converters showed a lower clustering index in several regions associated with neurodegeneration in AD. The SSGMNets' topological organization was revealed to be able to predict cognitive and memory measures. The findings presented here suggest that SSGMNets could indeed be used to identify MCI ApoE4 Carriers with a high risk for AD progression.


Subject(s)
Alzheimer Disease , Apolipoprotein E4 , Cognitive Dysfunction , Alleles , Alzheimer Disease/diagnostic imaging , Alzheimer Disease/genetics , Amyloid beta-Peptides , Apolipoprotein E4/genetics , Biomarkers , Cognitive Dysfunction/diagnostic imaging , Cognitive Dysfunction/genetics , Gray Matter/diagnostic imaging , Humans
14.
Geroscience ; 43(4): 1725-1765, 2021 08.
Article in English | MEDLINE | ID: mdl-33970414

ABSTRACT

In the absence of any neuropsychiatric condition, older adults may show declining performance in several cognitive processes and among them, in retrieving and producing words, reflected in slower responses and even reduced accuracy compared to younger adults. To overcome this difficulty, healthy older adults implement compensatory strategies, which are the focus of this paper. We provide a review of mainstream findings on deficient mechanisms and possible neurocognitive strategies used by older adults to overcome the deleterious effects of age on lexical production. Moreover, we present findings on genetic and lifestyle factors that might either be protective or risk factors of cognitive impairment in advanced age. We propose that "aging-modulating factors" (AMF) can be modified, offering prevention opportunities against aging effects. Based on our review and this proposition, we introduce an integrative neurocognitive model of mechanisms and compensatory strategies for lexical production in older adults (entitled Lexical Access and Retrieval in Aging, LARA). The main hypothesis defended in LARA is that cognitive aging evolves heterogeneously and involves complementary domain-general and domain-specific mechanisms, with substantial inter-individual variability, reflected at behavioral, cognitive, and brain levels. Furthermore, we argue that the ability to compensate for the effect of cognitive aging depends on the amount of reserve specific to each individual which is, in turn, modulated by the AMF. Our conclusion is that a variety of mechanisms and compensatory strategies coexist in the same individual to oppose the effect of age. The role of reserve is pivotal for a successful coping with age-related changes and future research should continue to explore the modulating role of AMF.


Subject(s)
Cognitive Reserve , Age Factors , Brain
15.
Sci Rep ; 11(1): 845, 2021 01 12.
Article in English | MEDLINE | ID: mdl-33436948

ABSTRACT

The Apolipoprotein E isoform E4 (ApoE4) is consistently associated with an elevated risk of developing late-onset Alzheimer's Disease (AD); however, less is known about the potential genetic modulation of the brain networks organization during prodromal stages like Mild Cognitive Impairment (MCI). To investigate this issue during this critical stage, we used a dataset with a cross-sectional sample of 253 MCI patients divided into ApoE4-positive (?Carriers') and ApoE4-negative ('non-Carriers'). We estimated the cortical thickness (CT) from high-resolution T1-weighted structural magnetic images to calculate the correlation among anatomical regions across subjects and build the CT covariance networks (CT-Nets). The topological properties of CT-Nets were described through the graph theory approach. Specifically, our results showed a significant decrease in characteristic path length, clustering-index, local efficiency, global connectivity, modularity, and increased global efficiency for Carriers compared to non-Carriers. Overall, we found that ApoE4 in MCI shaped the topological organization of CT-Nets. Our results suggest that in the MCI stage, the ApoE4 disrupting the CT correlation between regions may be due to adaptive mechanisms to sustain the information transmission across distant brain regions to maintain the cognitive and behavioral abilities before the occurrence of the most severe symptoms.


Subject(s)
Alzheimer Disease/pathology , Apolipoprotein E4/genetics , Brain Mapping/methods , Brain/metabolism , Cognitive Dysfunction/pathology , Magnetic Resonance Imaging/methods , Aged , Aged, 80 and over , Alzheimer Disease/genetics , Alzheimer Disease/metabolism , Apolipoprotein E4/metabolism , Brain/pathology , Cognitive Dysfunction/genetics , Cognitive Dysfunction/metabolism , Cross-Sectional Studies , Databases, Factual , Female , Humans , Male , Middle Aged
16.
Rev Med Suisse ; 17(723): 196-200, 2021 Jan 27.
Article in French | MEDLINE | ID: mdl-33507660

ABSTRACT

Significant developments were published in 2020 in the field of blood biomarkers in Alzheimer's disease. Several studies helped to define more accurately the management of status epilepticus and of epilepsy in women of childbearing age. The new Swiss guidelines for the pre-hospital management of acute stroke were issued, as are new targets for stroke prevention. Numerous advances concerning the management of NMO-SD (NeuroMyelitis Optica Spectrum Disorder) were published. Different neurological presentations linked to the COVID-19 pandemic were described (central and peripheral). Several studies confirmed the effectiveness of new migraine treatments (including anti-CGRP). New pharmacological therapies are available for Parkinson's disease.


L'année 2020 a vu d'importantes avancées dans le domaine des biomarqueurs sanguins pour le diagnostic biologique de la maladie d'Alzheimer. Plusieurs études permettent de mieux définir la prise en charge de l'épilepsie chez la femme en âge de procréer et de l'état de mal épileptique. Les nouvelles recommandations suisses pour la prise en charge préhospitalière de l'AVC aigu sont en cours de publication, tout comme de nouvelles cibles pour leur prévention secondaire. De nombreuses avancées concernant la prise en charge des Neuromyelitis Optica Spectrum Disorder ont été publiées. Divers tableaux neurologiques (centraux et périphériques) liés à la pandémie de Covid-19 ont été décrits. Plusieurs études ont permis de confirmer l'efficacité des nouveaux traitements de la migraine (notamment les anti-Calcitonin Gene-Related Peptide). Enfin, de nouvelles thérapies pharmacologiques sont disponibles pour la maladie de Parkinson.


Subject(s)
COVID-19 , Neurology , Female , Humans , Neuromyelitis Optica/epidemiology , Pandemics , SARS-CoV-2
17.
Rev Med Suisse ; 17(723): 225-229, 2021 Jan 27.
Article in French | MEDLINE | ID: mdl-33507666

ABSTRACT

Cognitive impairment can interfere with the fitness to drive. An increase in requests to assess this aspect is observed at Leenaards Memory Centre. Changes in the law could be an explanatory factor. The views formulated in 2019 are mainly unfavorable because all the patients present cognitive disorders, generally attributed to Alzheimer's disease or a related disorder, but never linked with aging only. Moreover, unfavorable views are frequently expressed before the age of 75. Therefore, each patient is unique, and each decision is based neither on the patient's age or his diagnosis, but rather on his cognitive profile. In this article we discuss the reasons for an unfavorable view and discuss them in the context of the tasks of our centre.


Les troubles cognitifs peuvent interférer avec l'aptitude à la conduite automobile. Une hausse des demandes d'évaluation ciblée sur cet aspect est observée au Centre Leenaards de la Mémoire. Les modifications de la loi pourraient être un facteur explicatif. Les avis formulés en 2019 sont majoritairement défavorables chez les patients présentant des troubles cognitifs dus à une maladie d'Alzheimer ou une pathologie apparentée, mais jamais en lien avec le vieillissement seul. Les avis défavorables sont fréquents avant l'âge de 75 ans. Chaque situation est donc unique et chaque décision prise se base non pas sur l'âge du patient, ni sur le diagnostic étiologique, mais sur le profil cognitif. Nous abordons dans cet article les raisons d'un avis défavorable et les discutons dans le contexte des missions de notre centre.


Subject(s)
Alzheimer Disease , Cognitive Dysfunction , Alzheimer Disease/diagnosis , Cognition , Cognitive Dysfunction/diagnosis , Feedback , Humans , Neuropsychological Tests
18.
Behav Med ; 47(3): 246-250, 2021.
Article in English | MEDLINE | ID: mdl-32078491

ABSTRACT

Baby-boomers might be more health-conscious than earlier birth cohorts, but limited evidence has been produced so far. To investigate such changes, this study compared health-related behaviors at age 65 to 70 among three successive five-year birth cohorts (pre-war: born 1934-1938; war: born 1939-1943 and baby-boom: born 1944-1948) representative of the community-dwelling population. Information about alcohol use, smoking, physical activity, and nutrition was compared across the three cohorts (n = 4,270 participants) using Chi-squared test. Alcohol and the mean nutritional intake score did not vary across cohorts, whereas the consumption of nonalcoholic drinks increased significantly from pre-war to war and to baby-boom cohort (p<.001). Other differences across cohorts were observed only in women: the proportion of women who never or rarely engaged in sports decreased from 52.9% in the pre-war cohort to around 43% in subsequent cohorts (p<.001), while the proportion of women who had never smoked was higher in the pre-war cohort (56.1%) than in the war and the baby-boom cohorts (49.8% and 46.8%, respectively, p<.001). Overall, these results show some positive changes in older persons' health behaviors over time. Nevertheless, considerable room remains for improving lifestyles through public health interventions.


Subject(s)
Birth Cohort , Health Behavior , Aged , Aged, 80 and over , Cohort Studies , Female , Humans , Smoking
19.
Mol Psychiatry ; 26(7): 3004-3017, 2021 07.
Article in English | MEDLINE | ID: mdl-33057169

ABSTRACT

Developmental dyslexia (DD) is a learning disorder affecting the ability to read, with a heritability of 40-60%. A notable part of this heritability remains unexplained, and large genetic studies are warranted to identify new susceptibility genes and clarify the genetic bases of dyslexia. We carried out a genome-wide association study (GWAS) on 2274 dyslexia cases and 6272 controls, testing associations at the single variant, gene, and pathway level, and estimating heritability using single-nucleotide polymorphism (SNP) data. We also calculated polygenic scores (PGSs) based on large-scale GWAS data for different neuropsychiatric disorders and cortical brain measures, educational attainment, and fluid intelligence, testing them for association with dyslexia status in our sample. We observed statistically significant (p < 2.8 × 10-6) enrichment of associations at the gene level, for LOC388780 (20p13; uncharacterized gene), and for VEPH1 (3q25), a gene implicated in brain development. We estimated an SNP-based heritability of 20-25% for DD, and observed significant associations of dyslexia risk with PGSs for attention deficit hyperactivity disorder (at pT = 0.05 in the training GWAS: OR = 1.23[1.16; 1.30] per standard deviation increase; p = 8 × 10-13), bipolar disorder (1.53[1.44; 1.63]; p = 1 × 10-43), schizophrenia (1.36[1.28; 1.45]; p = 4 × 10-22), psychiatric cross-disorder susceptibility (1.23[1.16; 1.30]; p = 3 × 10-12), cortical thickness of the transverse temporal gyrus (0.90[0.86; 0.96]; p = 5 × 10-4), educational attainment (0.86[0.82; 0.91]; p = 2 × 10-7), and intelligence (0.72[0.68; 0.76]; p = 9 × 10-29). This study suggests an important contribution of common genetic variants to dyslexia risk, and novel genomic overlaps with psychiatric conditions like bipolar disorder, schizophrenia, and cross-disorder susceptibility. Moreover, it revealed the presence of shared genetic foundations with a neural correlate previously implicated in dyslexia by neuroimaging evidence.


Subject(s)
Dyslexia , Multifactorial Inheritance , Polymorphism, Single Nucleotide , Attention Deficit Disorder with Hyperactivity/genetics , Dyslexia/genetics , Genetic Predisposition to Disease , Genome-Wide Association Study , Humans , Intracellular Signaling Peptides and Proteins/genetics
20.
Front Neurol ; 11: 1021, 2020.
Article in English | MEDLINE | ID: mdl-33071930

ABSTRACT

Introduction: With the shift of research focus to personalized medicine in Alzheimer's Dementia (AD), there is an urgent need for tools that are capable of quantifying a patient's risk using diagnostic biomarkers. The Medical Informatics Platform (MIP) is a distributed e-infrastructure federating large amounts of data coupled with machine-learning (ML) algorithms and statistical models to define the biological signature of the disease. The present study assessed (i) the accuracy of two ML algorithms, i.e., supervised Gradient Boosting (GB) and semi-unsupervised 3C strategy (Categorize, Cluster, Classify-CCC) implemented in the MIP and (ii) their contribution over the standard diagnostic workup. Methods: We examined individuals coming from the MIP installed across 3 Italian memory clinics, including subjects with Normal Cognition (CN, n = 432), Mild Cognitive Impairment (MCI, n = 456), and AD (n = 451). The GB classifier was applied to best discriminate the three diagnostic classes in 1,339 subjects, and the CCC strategy was used to refine the classical disease categories. Four dementia experts provided their diagnostic confidence (DC) of MCI conversion on an independent cohort of 38 patients. DC was based on clinical, neuropsychological, CSF, and structural MRI information and again with addition of the outcome from the MIP tools. Results: The GB algorithm provided a classification accuracy of 85% in a nested 10-fold cross-validation for CN vs. MCI vs. AD discrimination. Accuracy increased to 95% in the holdout validation, with the omission of each Italian clinical cohort out in turn. CCC identified five homogeneous clusters of subjects and 36 biomarkers that represented the disease fingerprint. In the DC assessment, CCC defined six clusters in the MCI population used to train the algorithm and 29 biomarkers to improve patients staging. GB and CCC showed a significant impact, evaluated as +5.99% of increment on physicians' DC. The influence of MIP on DC was rated from "slight" to "significant" in 80% of the cases. Discussion: GB provided fair results in classification of CN, MCI, and AD. CCC identified homogeneous and promising classes of subjects via its semi-unsupervised approach. We measured the effect of the MIP on the physician's DC. Our results pave the way for the establishment of a new paradigm for ML discrimination of patients who will or will not convert to AD, a clinical priority for neurology.

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