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Brain atrophy and cortical thinning are typically observed in people with Alzheimer's disease (AD) and, to a lesser extent, in those with mild cognitive impairment. In asymptomatic middle-aged apolipoprotein ε4 (ΑPOE4) carriers, who are at higher risk of future AD, study reports are discordant with limited evidence of brain structural differences between carriers and non-carriers of the ε4 allele. Alternative imaging markers with higher sensitivity at the presymptomatic stage, ideally quantified using typically acquired structural MRI scans, would thus be of great benefit for the detection of early disease, disease monitoring and subject stratification. In the present cross-sectional study, we investigated textural properties of T1-weighted 3T MRI scans in relation to APOE4 genotype, age and sex. We pooled together data from the PREVENT-Dementia and ALFA studies focused on midlife healthy populations with dementia risk factors (analysable cohort: 1585 participants; mean age 56.2 ± 7.4 years). Voxel-based and texture (examined features: contrast, entropy, energy, homogeneity) based morphometry was used to identify areas of volumetric and textural differences between APOE4 carriers and non-carriers. Textural maps were generated and were subsequently harmonised using voxel-wise COMBAT. For all analyses, APOE4, sex, age and years of education were used as model predictors. Interactions between APOE4 and age were further examined. There were no group differences in regional brain volume or texture based on APOE4 carriership or when age × APOE4 interactions were examined. Older people tended to have a less homogeneous textural profile in grey and white matter and a more homogeneous profile in the ventricles. A more heterogeneous textural profile was observed for females in areas such as the ventricles, frontal and parietal lobes and for males in the brainstem, cerebellum, precuneus and cingulate. Overall, we have shown the absence of volumetric and textural differences between APOE4 carriers and non-carriers at midlife and have established associations of textural features with ageing and sex.
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Envejecimiento , Apolipoproteína E4 , Imagen por Resonancia Magnética , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Envejecimiento/patología , Envejecimiento/genética , Apolipoproteína E4/genética , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Estudios Transversales , Genotipo , Heterocigoto , Caracteres SexualesRESUMEN
BACKGROUND AND PURPOSE: The Mediterranean diet (MedDiet) has been associated with reduced dementia incidence in several studies. It is important to understand if diet is associated with brain health in midlife, when Alzheimer's disease and related dementias are known to begin. METHODS: This study used data from the PREVENT dementia programme. Three MedDiet scores were created (the Pyramid, Mediterranean Diet Adherence Screener [MEDAS] and MEDAS continuous) from a self-reported food frequency questionnaire. Primary outcomes were hippocampal volume and cube-transformed white matter hyperintensity volume. Secondary outcomes included cornu ammonis 1 and subiculum hippocampal subfield volumes, cortical thickness and measures of cognition. Sex-stratified analyses were run to explore differential associations between diet and brain health by sex. An exploratory path analysis was conducted to study if any associations between diet and brain health were mediated by cardiovascular risk factors for dementia. RESULTS: In all, 504 participants were included in this analysis, with a mean Pyramid score of 8.10 (SD 1.56). There were no significant associations between any MedDiet scoring method and any of the primary or secondary outcomes. There were no differences by sex in any analyses and no significant mediation between the Pyramid score and global cognition by cardiovascular risk factors. CONCLUSIONS: Overall, this study did not find evidence for an association between the MedDiet and either neuroimaging or cognition in a midlife population study. Future work should investigate associations between the MedDiet and Alzheimer's disease and related dementias biomarkers as well as functional neuroimaging in a midlife population.
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Cognición , Demencia , Dieta Mediterránea , Humanos , Masculino , Femenino , Persona de Mediana Edad , Estudios Transversales , Demencia/prevención & control , Demencia/epidemiología , Demencia/diagnóstico por imagen , Cognición/fisiología , Neuroimagen/métodos , Imagen por Resonancia Magnética , Anciano , Hipocampo/diagnóstico por imagen , Hipocampo/patologíaRESUMEN
INTRODUCTION: Entorhinal cortex (EC) is the first cortical region to exhibit neurodegeneration in Alzheimer's disease (AD), associated with EC grid cell dysfunction. Given the role of grid cells in path integration (PI)-based spatial behaviors, we predicted that PI impairment would represent the first behavioral change in adults at risk of AD. METHODS: We compared immersive virtual reality (VR) PI ability to other cognitive domains in 100 asymptomatic midlife adults stratified by hereditary and physiological AD risk factors. In some participants, behavioral data were compared to 7T magnetic resonance imaging (MRI) measures of brain structure and function. RESULTS: Midlife PI impairments predicted both hereditary and physiological AD risk, with no corresponding multi-risk impairment in episodic memory or other spatial behaviors. Impairments associated with altered functional MRI signal in the posterior-medial EC. DISCUSSION: Altered PI may represent the transition point from at-risk state to disease manifestation in AD, prior to impairment in other cognitive domains.
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Enfermedad de Alzheimer , Adulto , Humanos , Enfermedad de Alzheimer/patología , Corteza Entorrinal/patología , Encéfalo/patología , Imagen por Resonancia Magnética/métodosRESUMEN
Ongoing assessment of patients with Alzheimer's disease (AD) in postapproval studies is important for mapping disease progression and evaluating real-world treatment effectiveness and safety. However, interpreting outcomes in the real world is challenging owing to variation in data collected across centers and specialties and greater heterogeneity of patients compared with trial participants. Here, we share considerations for observational postapproval studies designed to collect harmonized longitudinal data from individuals with mild cognitive impairment or mild dementia stage of disease who receive therapies targeting the underlying pathological processes of AD in routine practice. This paper considers key study design parameters, including proposed aims and objectives, study populations, approaches to data collection, and measures of cognition, functional abilities, neuropsychiatric status, quality of life, health economics, safety, and drug utilization. Postapproval studies that capture these considerations will be important to provide standardized data on AD treatment effectiveness and safety in real-world settings.
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Enfermedad de Alzheimer , Humanos , Enfermedad de Alzheimer/terapia , Disfunción Cognitiva , Proyectos de Investigación , Calidad de Vida , Estudios Observacionales como Asunto , Progresión de la EnfermedadRESUMEN
INTRODUCTION: Etiological diagnosis of neurocognitive disorders of middle-old age relies on biomarkers, although evidence for their rational use is incomplete. A European task force is defining a diagnostic workflow where expert experience fills evidence gaps for biomarker validity and prioritization. We report methodology and preliminary results. METHODS: Using a Delphi consensus method supported by a systematic literature review, 22 delegates from 11 relevant scientific societies defined workflow assumptions. RESULTS: We extracted diagnostic accuracy figures from literature on the use of biomarkers in the diagnosis of main forms of neurocognitive disorders. Supported by this evidence, panelists defined clinical setting (specialist outpatient service), application stage (MCI-mild dementia), and detailed pre-assessment screening (clinical-neuropsychological evaluations, brain imaging, and blood tests). DISCUSSION: The Delphi consensus on these assumptions set the stage for the development of the first pan-European workflow for biomarkers' use in the etiological diagnosis of middle-old age neurocognitive disorders at MCI-mild dementia stages. HIGHLIGHTS: Rational use of biomarkers in neurocognitive disorders lacks consensus in Europe. A consensus of experts will define a workflow for the rational use of biomarkers. The diagnostic workflow will be patient-centered and based on clinical presentation. The workflow will be updated as new evidence accrues.
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Disfunción Cognitiva , Demencia , Humanos , Disfunción Cognitiva/diagnóstico , Consenso , Sensibilidad y Especificidad , Demencia/diagnóstico , BiomarcadoresRESUMEN
Type 2 diabetes is a robust predictor of cognitive impairment. Impairment in allocentric processing may help identify those at increased risk for Alzheimer's disease dementia. The objective of this study was to investigate the performance of participants with and without diabetes on a task of allocentric spatial processing. This was a cross-sectional secondary data analysis study using baseline data from the European Prevention of Alzheimer's Dementia Longitudinal Cohort Study (EPAD LCS). Participants were aged 50 years and above and were free of dementia at baseline. Participants with no missing data on the variables of interest were included in this study. Our exposure variable was diabetes reported in the medical history. Our primary outcome was the Four Mountains Test (4MT), a novel task of allocentric processing. Covariates included demographics (age, sex, family history of dementia and years of education), APOEε4 carrier status, cognitive status (Clinical Dementia Rating scale), cerebrospinal fluid phosphorylated tau and amyloid-beta 1-42. Of 1324 participants (mean age = 65.95 (±7.45)), 90 had diabetes. Participants with diabetes scored 8.32 (±2.32) on the 4MT compared with 9.24 (±2.60) for participants without diabetes. In a univariate model, diabetes was significantly associated with worse 4MT total scores (ß = -.92, p = .001), remaining significant in a fully adjusted model (ß = -.64, p = .01). Cerebrospinal fluid phosphorylated tau was significantly higher in participants with diabetes compared with those without. Novel cognitive tests, such as the 4MT, may be appropriate to identify early cognitive changes in this high-risk group. Identifying those at greatest risk for future neurodegeneration is key to prevention efforts.
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Enfermedad de Alzheimer , Disfunción Cognitiva , Diabetes Mellitus Tipo 2 , Procesamiento Espacial , Humanos , Anciano , Enfermedad de Alzheimer/líquido cefalorraquídeo , Estudios Longitudinales , Estudios Transversales , Autoinforme , Disfunción Cognitiva/etiología , Estudios de Cohortes , Péptidos beta-Amiloides/líquido cefalorraquídeo , Biomarcadores/líquido cefalorraquídeo , Proteínas tau/líquido cefalorraquídeoRESUMEN
BACKGROUND: Markers of cerebrovascular disease are common in dementia, and may be present before dementia onset. However, their clinical relevance in midlife adults at risk of future dementia remains unclear. We investigated whether the Cardiovascular Risk Factors, Ageing and Dementia (CAIDE) risk score was associated with markers of cerebral small vessel disease (SVD), and if it predicted future progression of SVD. We also determined its relationship to systemic inflammation, which has been additionally implicated in dementia and SVD. METHODS: Cognitively healthy midlife participants were assessed at baseline (n=185) and 2-year follow-up (n=158). To assess SVD, we quantified white matter hyperintensities (WMH), enlarged perivascular spaces (EPVS), microbleeds and lacunes. We derived composite scores of SVD burden, and subtypes of hypertensive arteriopathy and cerebral amyloid angiopathy. Inflammation was quantified using serum C-reactive protein (CRP) and fibrinogen. RESULTS: At baseline, higher CAIDE scores were associated with all markers of SVD and inflammation. Longitudinally, CAIDE scores predicted greater total (p<0.001), periventricular (p<0.001) and deep (p=0.012) WMH progression, and increased CRP (p=0.017). Assessment of individual CAIDE components suggested that markers were driven by different risk factors (WMH/EPVS: age/hypertension, lacunes/deep microbleeds: hypertension/obesity). Interaction analyses demonstrated that higher CAIDE scores amplified the effect of age on SVD, and the effect of WMH on poorer memory. CONCLUSION: Higher CAIDE scores, indicating greater risk of dementia, predicts future progression of both WMH and systemic inflammation. Findings highlight the CAIDE score's potential as both a prognostic and predictive marker in the context of cerebrovascular disease, identifying at-risk individuals who might benefit most from managing modifiable risk.
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Enfermedades de los Pequeños Vasos Cerebrales , Demencia , Hipertensión , Adulto , Biomarcadores , Hemorragia Cerebral/complicaciones , Enfermedades de los Pequeños Vasos Cerebrales/complicaciones , Demencia/complicaciones , Humanos , Hipertensión/complicaciones , Inflamación/complicaciones , Imagen por Resonancia Magnética/efectos adversos , Factores de RiesgoRESUMEN
Individuals of the same chronological age exhibit disparate rates of biological ageing. Consequently, a number of methodologies have been proposed to determine biological age and primarily exploit variation at the level of DNA methylation (DNAm). A novel epigenetic clock, termed 'DNAm GrimAge' has outperformed its predecessors in predicting the risk of mortality as well as many age-related morbidities. However, the association between DNAm GrimAge and cognitive or neuroimaging phenotypes remains unknown. We explore these associations in the Lothian Birth Cohort 1936 (n = 709, mean age 73 years). Higher DNAm GrimAge was strongly associated with all-cause mortality over the eighth decade (Hazard Ratio per standard deviation increase in GrimAge: 1.81, P < 2.0 × 10-16). Higher DNAm GrimAge was associated with lower age 11 IQ (ß = -0.11), lower age 73 general cognitive ability (ß = -0.18), decreased brain volume (ß = -0.25) and increased brain white matter hyperintensities (ß = 0.17). There was tentative evidence for a longitudinal association between DNAm GrimAge and cognitive decline from age 70 to 79. Sixty-nine of 137 health- and brain-related phenotypes tested were significantly associated with GrimAge. Adjusting all models for childhood intelligence attenuated to non-significance a small number of associations (12/69 associations; 6 of which were cognitive traits), but not the association with general cognitive ability (33.9% attenuation). Higher DNAm GrimAge associates with lower cognitive ability and brain vascular lesions in older age, independently of early-life cognitive ability. This epigenetic predictor of mortality associates with different measures of brain health and may aid in the prediction of age-related cognitive decline.
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Cohorte de Nacimiento , Epigénesis Genética , Anciano , Envejecimiento/genética , Encéfalo/diagnóstico por imagen , Niño , Metilación de ADN/genética , Epigénesis Genética/genética , Epigenómica , HumanosRESUMEN
BACKGROUND: Mild cognitive impairment (MCI) is a condition that exists between normal healthy ageing and dementia with an uncertain aetiology and prognosis. This uncertainty creates a complex dynamic between the clinicians' conception of MCI, what is communicated to the individual about their condition, and how the individual responds to the information conveyed to them. The aim of this study was to explore clinicians' views around the assessment and communication of MCI in memory clinics. METHOD: As part of a larger longitudinal study looking at patients' adjustment to MCI disclosure, we interviewed Old Age Psychiatrists at the five participating sites across Scotland. The study obtained ethics approvals and the interviews (carried out between Nov 2020-Jan 2021) followed a semi-structured schedule focusing on [1] how likely clinicians are to use the term MCI with patients; [2] what tests clinicians rely on and how much utility they see in them; and [3] how clinicians communicate risk of progression to dementia. The interviews were voice recorded and were analysed using reflective thematic analysis. RESULTS: Initial results show that most clinicians interviewed (Total N = 19) considered MCI to have significant limitations as a diagnostic term. Nevertheless, most clinicians reported using the term MCI (n = 15/19). Clinical history was commonly described as the primary aid in the diagnostic process and also to rule out functional impairment (which was sometimes corroborated by Occupational Therapy assessment). All clinicians reported using the Addenbrooke's Cognitive Examination-III as a primary assessment tool. Neuroimaging was frequently found to have minimal usefulness due to the neuroradiological reports being non-specific. CONCLUSION: Our study revealed a mixture of approaches to assessing and disclosing test results for MCI. Some clinicians consider the condition as a separate entity among neurodegenerative disorders whereas others find the term unhelpful due to its uncertain prognosis. Clinicians report a lack of specific and sensitive assessment methods for identifying the aetiology of MCI in clinical practice. Our study demonstrates a broad range of views and therefore variability in MCI risk disclosure in memory assessment services which may impact the management of individuals with MCI.
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Disfunción Cognitiva , Psiquiatría , Cognición , Disfunción Cognitiva/diagnóstico , Disfunción Cognitiva/epidemiología , Humanos , Estudios Longitudinales , Neuroimagen , Pruebas NeuropsicológicasRESUMEN
A general obligation to make aggregate research results available to participants has been widely supported in the bioethics literature. However, dementia research presents several challenges to this perspective, particularly because of the fear associated with developing dementia. The authors argue that considerations of respect for persons, beneficence, and justice fail to justify an obligation to make aggregate research results available to participants in dementia research. Nevertheless, there are positive reasons in favor of making aggregate research results available; when the decision is made to do so, it is critical that a clear strategy for communicating results is developed, including what support will be provided to participants receiving aggregate research results.
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Demencia , Justicia Social , Humanos , Beneficencia , MiedoRESUMEN
BACKGROUND: Dementia is a syndrome that comprises many differing pathologies, including Alzheimer's disease dementia (ADD), vascular dementia (VaD) and frontotemporal dementia (FTD). People may benefit from knowing the type of dementia they live with, as this could inform prognosis and may allow for tailored treatment. Beta-amyloid (1-42) (ABeta42) is a protein which decreases in both the plasma and cerebrospinal fluid (CSF) of people living with ADD, when compared to people with no dementia. However, it is not clear if changes in ABeta42 are specific to ADD or if they are also seen in other types of dementia. It is possible that ABeta42 could help differentiate ADD from other dementia subtypes. OBJECTIVES: To determine the accuracy of plasma and CSF ABeta42 for distinguishing ADD from other dementia subtypes in people who meet the criteria for a dementia syndrome. SEARCH METHODS: We searched MEDLINE, and nine other databases up to 18 February 2020. We checked reference lists of any relevant systematic reviews to identify additional studies. SELECTION CRITERIA: We considered cross-sectional studies that differentiated people with ADD from other dementia subtypes. Eligible studies required measurement of participant plasma or CSF ABeta42 levels and clinical assessment for dementia subtype. DATA COLLECTION AND ANALYSIS: Seven review authors working independently screened the titles and abstracts generated by the searches. We collected data on study characteristics and test accuracy. We used the second version of the 'Quality Assessment of Diagnostic Accuracy Studies' (QUADAS-2) tool to assess internal and external validity of results. We extracted data into 2 x 2 tables, cross-tabulating index test results (ABeta42) with the reference standard (diagnostic criteria for each dementia subtype). We performed meta-analyses using bivariate, random-effects models. We calculated pooled estimates of sensitivity, specificity, positive predictive values, positive and negative likelihood ratios, and corresponding 95% confidence intervals (CIs). In the primary analysis, we assessed accuracy of plasma or CSF ABeta42 for distinguishing ADD from other mixed dementia types (non-ADD). We then assessed accuracy of ABeta42 for differentiating ADD from specific dementia types: VaD, FTD, dementia with Lewy bodies (DLB), alcohol-related cognitive disorder (ARCD), Creutzfeldt-Jakob disease (CJD) and normal pressure hydrocephalus (NPH). To determine test-positive cases, we used the ABeta42 thresholds employed in the respective primary studies. We then performed sensitivity analyses restricted to those studies that used common thresholds for ABeta42. MAIN RESULTS: We identified 39 studies (5000 participants) that used CSF ABeta42 levels to differentiate ADD from other subtypes of dementia. No studies of plasma ABeta42 met the inclusion criteria. No studies were rated as low risk of bias across all QUADAS-2 domains. High risk of bias was found predominantly in the domains of patient selection (28 studies) and index test (25 studies). The pooled estimates for differentiating ADD from other dementia subtypes were as follows: ADD from non-ADD: sensitivity 79% (95% CI 0.73 to 0.85), specificity 60% (95% CI 0.52 to 0.67), 13 studies, 1704 participants, 880 participants with ADD; ADD from VaD: sensitivity 79% (95% CI 0.75 to 0.83), specificity 69% (95% CI 0.55 to 0.81), 11 studies, 1151 participants, 941 participants with ADD; ADD from FTD: sensitivity 85% (95% CI 0.79 to 0.89), specificity 72% (95% CI 0.55 to 0.84), 17 studies, 1948 participants, 1371 participants with ADD; ADD from DLB: sensitivity 76% (95% CI 0.69 to 0.82), specificity 67% (95% CI 0.52 to 0.79), nine studies, 1929 participants, 1521 participants with ADD. Across all dementia subtypes, sensitivity was greater than specificity, and the balance of sensitivity and specificity was dependent on the threshold used to define test positivity. AUTHORS' CONCLUSIONS: Our review indicates that measuring ABeta42 levels in CSF may help differentiate ADD from other dementia subtypes, but the test is imperfect and tends to misdiagnose those with non-ADD as having ADD. We would caution against the use of CSF ABeta42 alone for dementia classification. However, ABeta42 may have value as an adjunct to a full clinical assessment, to aid dementia diagnosis.
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Enfermedad de Alzheimer/diagnóstico , Péptidos beta-Amiloides/sangre , Péptidos beta-Amiloides/líquido cefalorraquídeo , Fragmentos de Péptidos/sangre , Fragmentos de Péptidos/líquido cefalorraquídeo , Alcoholismo/complicaciones , Enfermedad de Alzheimer/sangre , Enfermedad de Alzheimer/líquido cefalorraquídeo , Sesgo , Biomarcadores/sangre , Biomarcadores/líquido cefalorraquídeo , Disfunción Cognitiva/sangre , Disfunción Cognitiva/líquido cefalorraquídeo , Disfunción Cognitiva/diagnóstico , Disfunción Cognitiva/etiología , Intervalos de Confianza , Síndrome de Creutzfeldt-Jakob/sangre , Síndrome de Creutzfeldt-Jakob/líquido cefalorraquídeo , Síndrome de Creutzfeldt-Jakob/diagnóstico , Demencia Vascular/sangre , Demencia Vascular/líquido cefalorraquídeo , Demencia Vascular/diagnóstico , Diagnóstico Diferencial , Demencia Frontotemporal/sangre , Demencia Frontotemporal/líquido cefalorraquídeo , Demencia Frontotemporal/diagnóstico , Humanos , Hidrocéfalo Normotenso/sangre , Hidrocéfalo Normotenso/líquido cefalorraquídeo , Hidrocéfalo Normotenso/diagnóstico , Enfermedad por Cuerpos de Lewy/sangre , Enfermedad por Cuerpos de Lewy/líquido cefalorraquídeo , Enfermedad por Cuerpos de Lewy/diagnóstico , Funciones de Verosimilitud , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: We classified non-demented European Prevention of Alzheimer's Dementia (EPAD) participants through the amyloid/tau/neurodegeneration (ATN) scheme and assessed their neuropsychological and imaging profiles. MATERIALS AND METHODS: From 1500 EPAD participants, 312 were excluded. Cerebrospinal fluid cut-offs of 1000 pg/mL for amyloid beta (Aß)1-42 and 27 pg/mL for p-tau181 were validated using Gaussian mixture models. Given strong correlation of p-tau and t-tau (R2 = 0.98, P < 0.001), neurodegeneration was defined by age-adjusted hippocampal volume. Multinomial regressions were used to test whether neuropsychological tests and regional brain volumes could distinguish ATN stages. RESULTS: Age was 65 ± 7 years, with 58% females and 38% apolipoprotein E (APOE) ε4 carriers; 57.1% were A-T-N-, 32.5% were in the Alzheimer's disease (AD) continuum, and 10.4% suspected non-Alzheimer's pathology. Age and cerebrovascular burden progressed with biomarker positivity (P < 0.001). Cognitive dysfunction appeared with T+. Paradoxically higher regional gray matter volumes were observed in A+T-N- compared to A-T-N- (P < 0.001). DISCUSSION: In non-demented individuals along the AD continuum, p-tau drives cognitive dysfunction. Memory and language domains are affected in the earliest stages.
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Amiloide/líquido cefalorraquídeo , Biomarcadores/líquido cefalorraquídeo , Voluntarios Sanos/estadística & datos numéricos , Hipocampo/patología , Proteínas tau/líquido cefalorraquídeo , Anciano , Europa (Continente) , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Pruebas Neuropsicológicas/estadística & datos numéricosRESUMEN
Performance validity tests (PVTs) are widely used in attempts to quantify effort and/or detect negative response bias during neuropsychological testing. However, it can be challenging to interpret the meaning of poor PVT performance in a clinical context. Compensation-seeking populations predominate in the PVT literature. We aimed to establish base rates of PVT failure in clinical populations without known external motivation to underperform. We searched MEDLINE, EMBASE and PsycINFO for studies reporting PVT failure rates in adults with defined clinical diagnoses, excluding studies of active or veteran military personnel, forensic populations or studies of participants known to be litigating or seeking disability benefits. Results were summarised by diagnostic group and implications discussed. Our review identified 69 studies, and 45 different PVTs or indices, in clinical populations with intellectual disability, degenerative brain disease, brain injury, psychiatric disorders, functional disorders and epilepsy. Various pass/fail cut-off scores were described. PVT failure was common in all clinical groups described, with failure rates for some groups and tests exceeding 25%. PVT failure is common across a range of clinical conditions, even in the absence of obvious incentive to underperform. Failure rates are no higher in functional disorders than in other clinical conditions. As PVT failure indicates invalidity of other attempted neuropsychological tests, the finding of frequent and unexpected failure in a range of clinical conditions raises important questions about the degree of objectivity afforded to neuropsychological tests in clinical practice and research.
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Pruebas Neuropsicológicas/normas , Reproducibilidad de los Resultados , HumanosRESUMEN
OBJECTIVE: Depression and trauma are associated with changes in brain regions implicated in Alzheimer's disease. The present study examined associations between childhood trauma, depression, adult cognitive functioning and risk of dementia. METHODS: Data from 378 participants in the PREVENT Dementia Study aged 40-59 years. Linear and logistic models were used to assess associations between childhood trauma, depression, dementia risk, cognitive test scores and hippocampal volume. RESULTS: Childhood trauma was associated with depression and reduced hippocampal volume but not current cognitive function or dementia risk. Poorer performance on a delayed face/name recall task was associated with depression. Childhood trauma was associated with lower hippocampal volume however poorer cognitive performance was mediated by depression rather than structural brain differences. CONCLUSION: Depressive symptomatology may be associated with dementia risk via multiple pathways, and future studies should consider subtypes of depressive symptomatology when examining its relationship to dementia.
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BACKGROUND: Increased rates of brain atrophy on serial MRI are frequently used as a surrogate marker of disease progression in Alzheimer's disease and other dementias. However, the extent to which they are associated with future risk of dementia in asymptomatic subjects is not clear. In this study, we investigated the relationship between the Cardiovascular Risk Factors, Aging, and Dementia (CAIDE) risk score and longitudinal atrophy in middle-aged subjects. MATERIALS AND METHODS: A sample of 167 subjects (aged 40-59 at baseline) from the PREVENT-Dementia programme underwent MRI scans on two separate occasions (mean interval 735 days; SD 44 days). We measured longitudinal rates of brain atrophy using the FSL Siena toolbox. RESULTS: Annual percentage rates of brain volume and ventricular volume change were greater in those with a high (>6) vs low CAIDE score-absolute brain volume percentage loss 0.17% (CI 0.07 to 0.27) and absolute ventricular enlargement 1.78% (CI 1.14 to 2.92) higher in the at risk group. Atrophy rates did not differ between subjects with and without a parental history of dementia, but were significantly correlated with age. Using linear regression, with covariates of age, sex and education, CAIDE score >6 was the only significant predictor of whole brain atrophy rates (p=0.025) while age (p=0.009), sex (p=0.002) and CAIDE>6 (p=0.017) all predicted ventricular expansion rate. CONCLUSION: Our results show that progressive brain atrophy is associated with increased risk of future dementia in asymptomatic middle-aged subjects, two decades before dementia onset.
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Atrofia/patología , Encéfalo/patología , Ventrículos Cerebrales/patología , Demencia/patología , Adulto , Factores de Edad , Progresión de la Enfermedad , Femenino , Humanos , Estudios Longitudinales , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Neuroimagen , Pruebas Neuropsicológicas , Valor Predictivo de las Pruebas , Factores de RiesgoRESUMEN
The Dementias Platform UK Data Portal is a data repository facilitating access to data for 3 370 929 individuals in 42 cohorts. The Data Portal is an end-to-end data management solution providing a secure, fully auditable, remote access environment for the analysis of cohort data. All projects utilising the data are by default collaborations with the cohort research teams generating the data. The Data Portal uses UK Secure eResearch Platform infrastructure to provide three core utilities: data discovery, access, and analysis. These are delivered using a 7 layered architecture comprising: data ingestion, data curation, platform interoperability, data discovery, access brokerage, data analysis and knowledge preservation. Automated, streamlined, and standardised procedures reduce the administrative burden for all stakeholders, particularly for requests involving multiple independent datasets, where a single request may be forwarded to multiple data controllers. Researchers are provided with their own secure 'lab' using VMware which is accessed using two factor authentication. Over the last 2 years, 160 project proposals involving 579 individual cohort data access requests were received. These were received from 268 applicants spanning 72 institutions (56 academic, 13 commercial, 3 government) in 16 countries with 84 requests involving multiple cohorts. Projects are varied including multi-modal, machine learning, and Mendelian randomisation analyses. Data access is usually free at point of use although a small number of cohorts require a data access fee.
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Manejo de Datos , Sistemas de Administración de Bases de Datos , Demencia , Investigación Biomédica , Estudios de Cohortes , Conjuntos de Datos como Asunto , Humanos , Reino UnidoRESUMEN
OBJECTIVES: Our group has already demonstrated that patients' health-related quality of life (HRQL) improves in the first 6 months after their first appointment at memory assessment services (MASs), but the sustainability of such gains is unknown. We aimed to describe changes in patients' HRQL at 12 months after their first MAS appointment and to examine associations with patient and MAS characteristics. METHODS: We collected data from 702 patients and 452 lay caregivers at the first appointment and 12 months later. Multivariable linear regression was used to examine the relationships of change in HRQL (self-reported and proxy-reported) with patients' characteristics and use of post-diagnostic interventions, and multilevel models were used to analyse the relationships of HRQL with MAS characteristics. RESULTS: In the whole group, self-reported HRQL improved over 12 months (+3.5 points, 95% CI 2.7 to 4.2). Among people diagnosed with dementia, improvement in HRQL was more than double that among those with mild cognitive impairment or no diagnosis. Proxy-reported HRQL improved only in those diagnosed with dementia (+1.2 points, 95% CI 0.2 to 2.2). Changes in HRQL were not associated with any patient characteristics. The only feature of MASs associated with larger improvements in HRQL was the presence of advisory and support staff. CONCLUSIONS: Improvements in HRQL observed at 6 months are maintained up to 1 year after the first MAS appointment, more so among those who receive a diagnosis of dementia. Continued follow-up will determine if the improvement is even longer lasting.
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OBJECTIVES: The aim of this study was to investigate whether structural and process characteristics of memory assessment services (MASs) are associated with outcomes (changes in patients' health-related quality of life (HRQL), carers' HRQL and carers' burden) over the first 6 months following the first appointment. METHODS: Data from 785 patients referred to 69 MASs and 511 of their lay carers, collected at the first appointment and 6 months later. Data on MAS characteristics were collected using a questionnaire at baseline. We used multilevel linear regression models to explore the associations of patients' HRQL and carers' outcomes with structural and process characteristics of MASs. Analyses were conducted on the full sample of patients and carers, and separately on those patients diagnosed with dementia. RESULTS: None of the structural (skill mix, workload, volume, provision of clinical assessments and provision of psychosocial support) or process (waiting time, length and number of appointments, anti-dementia drug use and psychosocial interventions use) characteristics included in the analyses were associated with patients' or carers' outcomes at 6 months, apart from the presence of allied health professionals (AHPs), which was associated with a DEMQOL score 2.7 points higher. When only those with a diagnosis of dementia were considered, the association with presence of AHPs was no longer observed. CONCLUSIONS: Apart from involving AHPs, alterations to the way MASs are structured or function appear unlikely to improve their effectiveness in improving patients' and carers' HRQL. It is possible that the characteristics of MASs may influence patients' and carers' experience, but this was not studied. Copyright © 2017 John Wiley & Sons, Ltd.
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Demencia/diagnóstico , Trastornos de la Memoria/diagnóstico , Servicios de Salud Mental/organización & administración , Calidad de Vida , Adaptación Psicológica , Anciano , Anciano de 80 o más Años , Técnicos Medios en Salud/estadística & datos numéricos , Cuidadores/psicología , Demencia/psicología , Femenino , Estado de Salud , Humanos , Masculino , Persona de Mediana Edad , Evaluación de Procesos y Resultados en Atención de Salud , Análisis de RegresiónRESUMEN
The term mild cognitive impairment has been associated with a varying degree of clinical utility and controversy. The concept has been introduced to try and define a pre-dementia period associated with underlying neurodegenerative pathology and a higher likelihood of the person developing a dementia syndrome. As scientific understanding improves then the definition of MCI rightly adapts, meaning that the MCI concept is prone quite rightly to frequent evolution. We consider that we are a long way away from the concept having evolved to a point where it can be embedded with confidence in clinical practice as a diagnosis but should remain as a term primarily for use in research.
Asunto(s)
Disfunción Cognitiva/diagnóstico , Anciano , Enfermedad de Alzheimer/psicología , Progresión de la Enfermedad , Evaluación Geriátrica , HumanosRESUMEN
PURPOSE: To examine whether ultra-widefield (UWF) retinal imaging can identify biomarkers for Alzheimer's disease (AD) and its progression. METHODS: Images were taken using a UWF scanning laser ophthalmoscope (Optos P200C AF) to determine phenotypic variations in 59 patients with AD and 48 healthy controls at baseline (BL). All living participants were invited for a follow-up (FU) after 2 years and imaged again (if still able to participate). All participants had blood taken for genotyping at BL. Images were graded for the prevalence of age-related macular degeneration-like pathologies and retinal vascular parameters. Comparison between AD patients and controls was made using the Student t test and the χ2 test. RESULTS: Analysis at BL revealed a significantly higher prevalence of a hard drusen phenotype in the periphery of AD patients (14/55; 25.4%) compared to controls (2/48; 4.2%) [χ2 = 9.9, df = 4, p = 0.04]. A markedly increased drusen number was observed at the 2-year FU in patients with AD compared to controls. There was a significant increase in venular width gradient at BL (zone C: 8.425 × 10-3 ± 2.865 × 10-3 vs. 6.375 × 10-3 ± 1.532 × 10-3, p = 0.008; entire image: 8.235 × 10-3 ± 2.839 × 10-3 vs. 6.050 × 10-3 ± 1.414 × 10-3, p = 0.004) and a significant decrease in arterial fractal dimension in AD at BL (entire image: 1.250 ± 0.086 vs. 1.304 ± 0.089, p = 0.049) with a trend for both at FU. CONCLUSIONS: UWF retinal imaging revealed a significant association between AD and peripheral hard drusen formation and changes to the vasculature beyond the posterior pole, at BL and after clinical progression over 2 years, suggesting that monitoring pathological changes in the peripheral retina might become a valuable tool in AD monitoring.